description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Disclosure Document Deposit Request; former Disclosure Document No: 503814 date Jan. 18, 2002 and 545573 date Jan. 26, 2004 PTO-1652 (8/99)
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] “Not Applicable”
REFERENCE TO A MICROFICHE APPENDIX
[0003] “Not Applicable”
BACKGROUND OF THE INVENTION
[0004] Millions of mankind have lost their lives killed by a variety of weapons in war history around the world. There are certainly no arms used without killing effect, disarmament remains as a means of arms control but it does not lessen power of weapons. It made me thinking about using “Anesthetic” as weapons to save human lives during military mission.
[0005] Anesthetic, compound of anesthetic and chemicals, drugs having result as anesthetic are proposed in use on military defense and attack being equipped with and without arms by ejecting, shooting, blowing, dropping, jetting, throwing, smoking out, spreading out, bombing, exploding and any other ways in warfare.
[0006] Syringe: First point of my invention is to use syringes in weapons, guns, etc, the second point of my invention is to particularly make the syringe in which both pressing moving piston and transfusing liquid are at one side without using one's thumb being a special effect of syringe-bullets in use for shooting guns, weapons that a traditional syringe does not possess.
BRIEF SUMMARY OF THE INVENTION
[0007] My theory invention is to suggest using anesthetic as materials in all kinds of weapons, bullets, syringes, grenades, mines, bombs, rockets, missiles, sprayers, guns of all sorts; guns, rifles, automatic rifles, etc by anesthetizing opposing enemies being captured prisoners as a deal or/and against our hostage soldiers for later exchange to be a kind of world weapons that human lives will be saved during their military missions under future international commitment in the United Nations, it is the first advantage.
[0008] Anesthetic bullets and syringes for guns can well be used for shooting disobedient running person for arrest to probe head murderer and for shooting animals to have them captured alive but usual bullets are barely for fast killing effect, it is another advantage.
[0009] The invention includes anesthetic, compound of anesthetic, chemicals, drugs having result as anesthetic, weapons, guns, rifles, automatic rifles, bullets, grenades, mines, bombs, rockets, missiles, sprayers, arms etc., boiling, sugar, oil, mixture anesthetic bullets, the said invention syringes; injection syringes, more needle injection syringes, automatic injection syringes, syringe bullets, parts of container, container pipe, needle, moving bullet-piston, accessories, military defense and attack of all forms; by ejecting, shooting, blowing, dropping, jetting, throwing, smoking out, spreading out, bombing, exploding, etc.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0010] FIG. 1 : Mixture anesthetic bullets
[0011] FIG. 2 : Injection syringes
[0012] FIG. 3 : Double needle syringe
[0013] FIG. 4 : Structure of injection syringe
[0014] FIG. 5 : Automatic injection syringe or syringe bullets
[0015] FIG. 6 : Injection syringes of all sorts
[0016] FIG. 7 : Shooting in action
DETAILED DESCRIPTION OF THE INVENTION
[0017] Anesthetic, compound of anesthetic and chemicals having result as anesthetic are used as materials in weapons of all kinds; anesthetic bullets, syringes for guns, etc, as well as on military defense and attack to be regarded as my theory invention that does not exist in warfare arms.
[0018] FIG. 1 ; Mixture anesthetic bullet: Anesthetic bullets are different from usual ones, its bullet 1 is made from mixture of sugar and oil as outer cover containing anesthetic 2 inside. Boiling mixture of sugar and oil at hot temperature makes out the form of bullet which will harden as crystal once it becomes cold.
[0019] Mixture anesthetic bullet can be made as small as pill with its sharp point for easily entering one's body to avoid unnecessary treatment. Mixture anesthetic bullet will liquefy at warm temperature to anesthetize and to paralyze one's body into paralyzing state for certain hours, it is the moment for capturing.
[0020] FIG. 2 ; Injection syringe, FIG. 3 ; Double needle syringe, FIG. 4 ; Structure of injection syringe: are kinds of bullets for equipping in guns to inject anesthetic liquid into ones' bodies by shooting in which transfusing anesthetic liquid 2 from containers 3 through container pipes 5 to needles; both single/more needles 6 and moving bullet-pistons 4 are manufactured being placed ones next to the others pressing and ejecting at the same sides without using ones' thumbs. Inserting into one's body is by shooting to press the moving bullet-piston for anesthetic liquid transfusion at one time action. More needles can be manufactured to speed up liquid transfusion.
[0021] FIG. 5 : Superior automatic injection syringe or syringe bullet does not have container pipe, liquid transfusion 2 passes from container 3 directly through moving bullet-piston 4 to its needle 6 pressing and ejecting at the same side. FIG. 6 : 7 to 16 reveals one to five needle injection syringes, over five needle and bigger needle syringes will be made according to structures of its original fundamentals. FIG. 7 : shows an example of shooting in action.
[0022] The scope of protection of the invention covers the original elements, structures, function, composition, process of making, contents, illustrations as well as installation and/or any other structures, formation, modifications, replacement of parts, materials assembling to make up the same or similar equivalents referring to their original fundamentals having the same result changing other names, using the invention everywhere, combining the invention with any other materials, chemicals, arms, objects, etc having similar outcome by changing other names. | Anesthetic is regarded new weapon in warfare use as a deal for an exchange of captured prisoners between two sides. Human lives can be saved during their military mission. | 5 |
FIELD OF INVENTION AND PRIOR ART
The invention relates to a narrow gauge hydrostatic-drive tractor utilizing a prime mover, a hydraulic transmission, and a hydraulic motor.
Tractors involving a prime mover, a hydraulic transmission and a hydraulic motor are known in the art but have the disadvantage that they are wide and difficult to operate and control for certain purposes.
For example, tractors of the class described have not been entirely suitable for use in chicken houses for removing droppings. Ideally, such housings are arranged so that the droppings fall into troughs on each side of a narrow concrete walkway. It is desirable to have a tractor capable of operating on this way with a tool holder at one end adapted to hold scrapers and like tools for moving droppings along the troughs to the end of the chicken house. None of the tractors heretofore available have been entirely satisfactory for this purpose.
OBJECTS OF THE INVENTION
It is an object of the invention to provide an improved narrow gauge hydrostatic-drive tractor. It is an object of the invention to provide such a device which is rugged and efficient. It is a further object of the invention to provide such a device having effective means for cooling the hydraulic fluid. It is a further object of the invention to provide such a device having the advantages of a fixed-displacement motor without the disadvantages thereof. It is a further object of the invention to provide such a device with sufficient traction to handle heavy loads. Further objects of the invention are to avoid the disadvantages of the prior art and to obtain such advantages as will appear as the description proceeds.
BRIEF DESCRIPTION OF THE INVENTION
The invention relates to a narrow gauge, hydrostatic-drive tractor comprising an air-cooled prime mover having a drive shaft, a variable-displacement, reversible hydraulic pump having a driven shaft coupled with the drive shaft of the prime mover by direct mechanical coupling, a fixed-displacement hydraulic motor having a drive shaft and being hydraulically coupled to the pump by means of a hydraulic circuit in which the output of the pump is supplied directly to the input of the motor and the output of the motor is supplied directly to the input of the pump, a fan and fan housing at the end of the prime mover opposite the drive shaft, an air conduit means extending vertically upward from the fan housing for supplying ambient air to cool the prime mover, cooling means disposed in the air conduit means in heat-exchange with the ambient air drawn in, with the cooling means functioning to cool the hydraulic fluid in the hydraulic circuit, and differential means having transverse axles and a driven shaft, and wheels connected to the axles, said motor being disposed beneath the fan housing with its drive shaft projecting beyond the housing and beneath the driven shaft of the differential and mechanically coupled thereto.
Advantageously, the hydraulic circuit is kept charged by a charge pump circuit comprising a charge pump driven by the prime mover and having input and output ports in which the output flows in a closed cycle back to the charge pump through the cooling means and in which the closed cycle communicates with the hydraulic circuit by means of check-valve means which permits flow of hydraulic fluid into the hydraulic circuit as required to compensate for the loss of hydraulic fluid through leakage, and in which supply means are provided to furnish make-up hydraulic fluid to the closed cycle. Advantageously, the supply means comprises means for bleeding leakage from the hydraulic circuit into the closed cycle. It also preferably includes a reservoir. Preferably, the output of the charge pump flows through the cooler and then into the reservoir and then to the input of the charge pump. Also, it is of advantage to provide a by-pass valve means arranged so that the output of the charge pump by-passes the cooler to the reservoir when the output pressure of the charge pump exceeds a set value.
Advantageously, the hydraulic circuit comprises pressure-actuated, cross-over relief valve means arranged to by-pass hydraulic fluid by the motor when the pressure in the hydraulic circuit exceeds a certain value. This makes it possible to use a fixed-displacement hydraulic motor without danger of damage thereto if the pressure in the hydraulic circuit becomes excessive due to a heavy load or an obstacle preventing forward motion of the tractor. Advantageously, the cross-over relief valve means comprises two one-way valves, one of which is pressure-actuated when the flow of fluid in the hydraulic circuit is in one direction and the other of which is pressure-actuated when the flow is in the opposite direction.
It is of advantage also to provide a manually-controlled by-pass for the motor so that the tractor can be manually moved. When such a by-pass is open and the tractor is manually moved, the motor functions as a pump, the output of which flows back to the motor. When the by-pass is closed, the hydraulic circuit also is closed, so that the motor cannot move except in response to the variable-displacement pump.
Advantageously, the prime mover, the pump, and the motor are supported by a frame which comprises longitudinal parallel beams, the front ends of which are supported in and form a unitary part of the housing of the differential and the rear ends of which are supported by a vertically-trunnioned idler-wheel assembly adapted to rotate about its vertical axis to steer the tractor. It is of advantage also to have the diameter of the drive wheels substantially the same as the spacing from the outside of one wheel to the outside of the other wheel. Advantageously, the wheels are separated from each other by less than two widths of the wheels. It is of advantage also for the frame to carry a superstructure which extends up over the wheels supporting an operator's seat.
The air conduit means, conveniently, is disposed between the two wheels and between the seat and the prime mover. Also, it is of advantage if the overall width of the tractor is not substantially greater than the diameter of the wheels. By these features, a narrow, rugged tractor is provided in which the wheels are sufficiently large and have a sufficiently large base to provide adequate traction for moving heavy loads.
It is of advantage to provide a vertical steering column adjacent the seat and to connect it to the guide wheel by a roller-chain drive. Advantageously, two such chains are used, one of which connects the steering column with a sprocket at the bottom of a vertically-disposed trunnion, and the other of which connects the guide wheel to a sprocket at the top of the vertically-disposed trunnion. It is of advantage to have the first chain disposed along the bottom of one side of the frame running from the bottom sprocket on the vertical trunnion to and around a plurality of front end sprockets, one of which is unitary with the steering column. Preferably, the front end sprockets are mounted on the bottom of a transverse bumper or other support affixed to the bottom of the forward portion of the superstructure or frame and, preferably, comprises two direct sprockets and two idler sprockets. The direct sprockets are those which operate on the same side of the chain as the bottom sprocket on the vertical trunnion and the idler sprockets are those which operate on the opposite side of the chain. Advantageously, the sprocket which is unitary with the steering column is an idler sprocket. It is desirable to provide means for tightening the first chain about the sprockets which, advantageously, can be a turnbuckle in the chain or means for moving one of the direct or idler sprockets.
In the preferred form of the invention the tractor is provided with a transverse guide holder rearward of the guide wheel which, advantageously, is affixed to arms pivotally mounted on a transverse trunnion journaled in the frame forward of the idler wheel. This tool holder can be raised or lowered by causing the arms to rotate about the trunnion. This, advantageously, is accomplished by means of the bell crank arrangement unitary with one of the arms connected to a control lever adjacent the seat.
The invention also relates to improvements in scraping means for use in conjunction with a narrow gauge tractor, such as described above, adapted to run on a narrow walkway between parallel troughs, which scraping means is complementary with said troughs, so that when the tractor is driven down the walkway with the scrapers in the troughs, material in the troughs is pushed along toward the ends of the troughs.
In particular, the invention relates to a combination with a narrow gauge tractor of the class described which has drive wheels at the front end and idler wheel means at the rear end, so arranged that the entire weight of the tractor is supported by the drive wheels and the idler wheel means, with the scraper means located adjacent to and in front of the drive wheels, together with connecting means for connecting the scraping means to the front end of the tractor, so arranged that when the scrapers are loaded, the weight of the material therein will cause the idler wheel means to be lifted off the walkway so that the entire weight of the tractor rests on the drive wheels, and guide means adjacent the rear end of the tractor for guiding it along said walkway when the idler wheel means is off the walkway.
By this combination, it is possible to obtain the most efficient traction between the drive wheels and the walkway so that heavy loads of material can be handled.
Advantageously, the scraping means has a hinged scraping blade so that, when the tractor is backed up, the blade will ride up over any material still left in the trough and, when it is moved forward again, the blade will again be in material-engaging position. Also, it is of advantage to provide limiting means, for example, rollers, adapted to roll on the sides of the troughs to limit the extent to which the scraping means enters into the troughs. It is also of advantage to provide adjusting means for adjusting the extent to which the scraper blades can swing downwardly about the hinges.
In the preferred form of the invention, the scraping means comprises a central portion having depending sides adapted to straddle the walkway and front portions having depending sides adapted to fit down into the troughs. Advantageously, the central portion of the side portions have common depending sides. Also, advantageously, the depending sides depend from parallel transverse tubular members. In such case, it is of advantage to have the scraper blade hinged to the rear transverse tubular member. Also, it is of advantage to have the adjusting means made of chains affixed to the front end of the scraper blades and adapted to be held in slots fastened or affixed to the forward tubular member. The slots are arranged so that one link of the chain can go in sideways, but not crosswise, so that the chain can be raised or lowered link by link.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a side elevation taken along line 1--1 of FIG. 2.
FIG. 2 is a rear elevation.
FIG. 3 is a side elevation taken along line 3--3 of FIG. 4.
FIG. 4 is a front elevation.
FIG. 5 is a plan view.
FIG. 6 is a bottom view.
FIG. 7 is an isometric view of the scraping means.
FIG. 8 is a plan view of FIG. 7.
FIG. 9 is a side elevation with parts broken away of a tractor scraper and guide assembly.
FIG. 10 is a schematic view showing general arrangement of parts and flow diagrams.
DETAILED DESCRIPTION OF THE INVENTION
Referring now particularly to FIGS. 1 through 10, there is shown a tractor according to the invention comprising an air-cooled gasoline engine 10 having the usual appurtenances, such as, starter 12, battery 14, air cleaner 16, muffler 18, fan housing 20, and such other appurtenances as are commonly found on an air-cooled gasoline engine.
The drive shaft (not showns) of the gasoline engine 10 projects rearwardly and is directly and mechanically connected with the hydraulic transmission 22 which, suitably, is of the Sundstrand type.
The tractor is driven by two large wheels 24 and 26 fastened to the axles 28 of a differential 30 having a housing 32 and a driven shaft 34. The driven shaft 34 extends rearwardly to a point adjacent the fan housing 20 of the engine 10 and is connected to the hydraulic motor 36 disposed underneath the engine 10 with its drive shaft 38 projecting out beyond the fan housing 20 and parallel to and underneath the driven shaft 34 of the differential 30. The drive shaft 38 is connected to the driven shaft 34 by a chain drive 40.
The hydraulic transmission 22 is controlled by the lever 42 connected to the transmission control lever 44 by connecting rod 46. Movement of the lever 42 is effective to control the amount of displacement and the direction of flow and the hydraulic transmission is connected to the motor as shown in FIG. 10.
Referring now to FIG. 10, it will be seen that the Sundstrand transmission comprises a variable-displacement pump 48 which is directly connected to the gas engine 10 by drive shaft 50. The variable-displacement pump 48 has input-output ports 52 and 54 which, depending on how the pump is set, delivers hydraulic fluid in the direction shown by the arrows. The hydraulic motor 36 also has ports 56 and 58 which function as input or output ports according to the direction of flow.
The pump 48 is connected to the motor 36 directly by flow lines 60 and 62 which form, with the pump and the motor, a hydraulic circuit, so that hydraulic fluid flows directly from the pump 48 to the motor 36 and directly back to the pump.
The pump 48 is a variable-displacement pump in which the output is controlled by the setting of the control lever 44. The motor 36 is a fixed-displacement motor with the result that the speed of the motor is variable according to the setting of the variable-displacement pump 48.
When the control lever 44 is set in the neutral position, that means that there is no flow in lines 60 and 62 and the motor does not turn. However, in this condition, the tractor becomes immobile and cannot be mechanically moved. For this reason, there is provided a mechanically-actuated by-pass valve 64 which, suitably, is the Greesen-type selector valve. The selector valve 64 comprises a cylinder 66 having a double piston 68-70 on the manually-operated piston rod 72. The cylinder 66 is connected to the flow line 60 by by-pass line 74, and flow line 62 by by-pass line 76. When the double piston 68-70 is in the position shown, flow of hydraulic fluid in by-pass line 74A and 76A is blocked. However, when piston rod 72 is moved to the position shown in dotted lines by the handle 78 and the double piston 68-70 assumes the position shown in the dotted lines, flow from by-pass line 74 to and from by-pass line 76, or vice versa, is made possible. This provides for flow of hydraulic fluid from flow line 60 to flow line 62 or vice versa, so that the motor can be disconnected from the variable-displacement pump. Thus, a neutral condition can be obtained by the use of the manually-operated Greesen selector valve 64, so that the variable-displacement pump does not affect the motor. Or, if the variable-displacement pump 48 is set at neutral, the motor is still not connected with the pump, so that the tractor can be pushed manually during which the fixed-displacement motor 36 acts as a pump to pump hydraulic fluid to line 74 and 74A or 76 and 76A through the cylinder 66, through line 74 and 74A or 76 and 76A (depending on the direction) and back to the motor 36, and vice versa.
In order to protect the fixed-displacement motor 36, there is provided in the by-pass circuit, a cross-over relief valve 80, which is pressure-actuated when the pressure in line 60 or 62 becomes excessive. The cross-over relief valve 80 comprises two pressure-actuated check valves 82 and 84. Thus, the pressure-actuated check valve 82 permits flow from by-pass line 76 into by-pass line 74 and the corresponding valve 84 permits flow in the opposite direction. This has particular advantage in combination with a fixed-displacement motor, because of the possibility of the tractor becoming stalled with the result that excessively high pressure which could damage the motor 36 could develop in lines 60 and 62.
To compensate for leakage in the pump 48 and motor 36, there is provided a charge pump 86 which, suitably, is a small gear pump which is adapted to pump hydraulic fluid in a closed circuit. In the modification shown, the closed circuit comprises the output line 88 which leads to cooler 90 which, in turn, leads through line 92 to reservoir 94 which, in turn, leads through line 96 to filter 98 from which the hydraulic fluid is returned to the charge pump through the input line 100.
Connected to the output line 88 are charge lines 102 and 104. These charge lines communicate, respectively, with lines 60 and 62 through one-way check valves 106 and 108. When the pressure in lines 60 and 62 becomes too low, that is, below the set value, the check valves 106 and 108 open to allow replacement fluid to flow into the hydraulic circuit comprising the pump 48, motor 36, and flow lines 60 and 62. Also, a pressure-relief valve 110 is provided to pass hydraulic fluid from the closed circuit of the charge pump to the reservoir 94 and by-pass the cooler 90.
The cooler 90 is disposed in the upper portion of an air intake conduit 112 communicating with the fan housing 20, so that the ambient air which is drawn in to cool the gas engine 10 also cools the hydraulic fluid in the system.
Make-up of hydraulic fluid for that loss can be provided by charging additional fluid into the reservoir. Also, leakage lines 114 and 116, respectively, from the pump 48 and the motor 36 gather leaked fluid and return it to the system through the cooler 90 via the line 118.
The fixed-displacement motor is mechanically connected to the differential 30 by the chain drive 40.
Thus, operation of the gasoline engine drives the variable-displacement pump 48 which, in turn, drives the fixed-displacement motor 36 which, in turn, drives the differential, which differential 30, through the axles 28, is connected to the wheels 24 and 26.
The wheels 24 and 26 comprise large tires 122 and 124 which have relatively large tread surfaces 126 to provide the desired traction. The wheels 24 and 26 are spaced apart such that the space between the wheel is not greater than two tread widths. Also, the diameter of the wheels 24 and 26, including the tires thereon, is such that the overall width of the tractor is not substantially greater than the diameter of the wheels. This makes for a narrow, compact tractor with large wheels having a wide-traction surface.
The gas engine 10, the hydraulic transmission 22, and the motor 36 are supported on a frame 128 comprised of two parallel beams 130 and 132 which are supported by the differential housing 32, united therewith as an integral part thereof. The rear end of the frame 128 is supported by a transverse member 134 in which is journaled a vertical trunnion 136 connected to a fork 138 in which is journaled the guide wheel 140. Thus, the idler wheel 140 is adapted to be turned on a vertical axis to provide for steering of the tractor.
Mounted on the trunnion 136 is sprocket 142 and mounted on the beam 132 is a vertical trunnion 144 having a bottom sprocket 146 and a top sprocket 148 which is connected to the sprocket 142 by a roller chain 150. The top sprocket 148 and the bottom sprocket 146 rotate as a unit. At the front end of the tractor is a bumper 152 having clevis pin holes 153 therein. To the bottom of this bumper is attached a plurality of sprockets adapted to cooperate with the bottom sprocket 146 to provide control of the idler wheel 140. These sprockets comprise direct sprockets 154 and 156 and idler or indirect sprockets 158 and 160. A roller chain 162 goes over sprockets 146, 154, and 156 and under sprockets 158 and 160. The chain is provided with a turnbuckle 164 for tightening the same. One of the sprockets at the front end, suitably, the idler or indirect sprocket 160 is affixed to the bottom of the vertical steering column 166, provided with a handle 168 or other means for rotating the steering column 166. Thus, when the steering column 166 is rotated, movement is imparted to the idler wheel 140, so that the direction of the tractor can be controlled and varied.
Between the wheels 24 and 26 and supported on the frame 128 is a superstructure 170 adapted to support an operator's seat 172 above the wheels 24 and 26.
Between the wheels 24 and 26 and between the seat 172 and the engine 10, there is provided a vertically-disposed air conduit 174 which communicates with the fan housing 20 so that ambient air for cooling the engine 10 is drawn in through the air conduit 174. The air conduit 174 is disposed between the wheels 24 and 26 and between the seat 172 and the engine 10, and extends down to a position just above the chain drive 40 and the housing 32 of the differential.
Disposed in the intake portion of the air conduit 174 is the cooler 90. Oil is supplied to the cooler 90 through lines 88 and 92, as described in regard to FIG. 10. The upper part of the cooler 90 is protected by a frame 176 which, suitably, is closed in with screening to prevent large particles from entering the air stream.
At the rear end of the tractor there is provided a transverse guide holder 178 having adjustable guide holding means 180. The guide holding means 180 are mounted on tubes or bars 182 adapted to telescope into the guide holder 178. Suitable pin and pin holes 184 are provided for adjustment of the tubes 182 in or out. The guide holder 178 is adapted to hold vertical plates 179 or like guides adapted for maintaining the position of the tractor with respect to an elevated walkway located between the guides 180 and to enable the tractor to traverse the said walkway without falling off laterally.
The guide holder 178 is affixed to parallel arms 181 by means of rods 183 adapted to telescope in tubes 185 mounted on the arms 181. The arms 181 are journaled to the beams 130 and 132 by a trunnion 187 passing through a tube 186 welded between the beams 130 and 132. Thus, the tool holder 178 can be raised or lowered, according to the position of the arms 181. Stops 188 are provided to limit the downward motion of the arms 181. At the trunnion end of the arms 181 is a bell crank 190 which is connected by means of the connecting rod 192 to a foot lever 194 at the forward end of the tractor. Pushing the lever 194 forward will cause the tool holder 178 to be raised. Means, not shown, is provided for engaging the lever 194 to hold it in the raised position. The top part 196 of the lever 194 may be made removable and stored on lug 198.
At the other end of the tractor, i.e., the front, means are provided for mounting a scraping means adapted to be pushed along by the tractor in parallel troughs 200 and 202 on each side of a narrow walkway 204. The scraping means comprises a central portion 206 having depending sides 208 and 210 adapted to straddle the walkway 204, and side portions 212 and 214 also having depending sides 216 and 208 for side portion 212, and 218 and 210 for side portion 214. The side portions 212 and 214 extend down into the troughs 200 and 202. The depending sides 208, 210, 216, and 218 depend from parallel transverse tubular members 220 and 222, which form a cantilever-type bridge for supporting the side portions 212 and 214.
The central portion 206 has a transverse member 224 adjacent the rear which is parallel to the tubular member 220. Vertical channel bars 226 and 228 are welded between the transverse member 224 and the tubular member 220, to form a support for the tractor hitch. The tractor hitch comprises a transverse bar 230 having a clevis 232 at each end having clevis pin holes 234 therein. The clevises 232 are adapted to fit over the bumper 152 with the holes 234 in registry with the holes 153, so that the clevis pins 236 can be inserted to fasten the scraper means to the front end of the tractor.
The central portion 206 has triangular portions 236 welded in the corners between the depending sides 208 and 210 and the transverse tubular members 220 and 222. This is for the purpose of rigidity.
Similarly, the side portions 212 and 214 have triangular members 228 welded in the corners, as shown, plus a tie bar 240 to reinforce the side portions against the drag pulled on them by the material in the troughs.
The side portions 212 and 214 are provided with scraper blades 242 and 244 which are hinged at 246 and 248 to the transverse tubular member 220. To the front or forward ends of the scraper blades 242 and 244 are attached chains 250 which extend up to the transverse tubular member 222 where they are fastened in the slot connectors 252 which have a slot just wide enough to receive one link sideways, but not wide enough to receive the link crosswise. Thus, the height of the forward edge of the scraper blades 242 and 244 can be raised or lowered by removing the chain from the slot connector 252 and putting a different link therein.
On the outside of depending sides 216 and 218 are rollers 254 and 256 which are mounted in brackets 258 and 260 which are fastened to the sidewalls 216 and 218 by the adjustable bolt and slot connection 262-264. The roller is adapted to ride on the side of the troughs 200 and 202 and thus limit the extent to which the side portions 212 and 214 can enter into the trough. These rollers, coupled with the chains 250, make it possible to adjust the space between the bottom edge of the scraper blades 240 and 244 and the bottom of the trough 200 and 202. This is an important feature, as will be seen as the description proceeds.
The scraping means is fastened to the front end of the tractor by a truss, one element of which is the tractor, the other element of which is the scraping means, and the other element of which is chain 262. The chains 262 are connected between eyes 264 on a transverse bar 266 in the forward lower portion of the central portion 206 and eyes 171 at the top of the superstructure 170.
The length of chain 262 and the adjustment of chains 252 and the rollers 254 and 256 are such that, at rest, the forward edges of the scraper blades 242 and 244 are off the bottom of the troughs and the rollers 254 and 256 are off the side edges of the troughs. Thus, when the tractor is moved forward and a load of material impinges on the scraper blade, the combined vectors, of the weight of the material and the forwrd motion of the tractor, pull the scraping means down, so that the rollers 254 make contact with the sides of the troughs, with the result that the idler wheel 140 is lifted off the walkway 204, as shown in FIG. 9. At the same time, the guide plates 178 still remain in position, straddling the walkway 204, so that the tractor continues in a straight path down the walkway 204. This lifting of the idler wheel 140 off the walkway 204 shifts the whole weight of the tractor on the drive wheels 122 so that really effective traction is obtained. Also, the weight of the material accumulated in the scraper adds a further load to the drive wheels and thus further enhances the traction. Thus, the more the scraper digs in, the greater the traction.
Wear plates 268 are provided near the bottom of the depending sides 208 and 210 on the sides thereof which are apposed to the sides of the walkway 204. Similar wear plates 260 are affixed adjacent the bottom of the depending sides 216 and 218 on the side apposed to the outer walls of the troughs 200 and 202.
While the gasoline engine 10 will ordinarily be operated at a fixed speed by means of a governor, it will be understood that a throttle can be provided for the engine, if desired.
It will thus be seen that there is provided a rugged, narrow gauge, hydraulic or hydrostatic-drive tractor suitable for maneuvering droppings in a hen house where the way between the dropping troughs is narrow and where the load is great. It will be seen that there is provided a tractor having a high degree of versatility and many safety factors, making it suitable for operation by unskilled persons and also a tractor which is highly effective for its intended purpose and avoids the disadvantages of the prior art.
It is to be understood that the invention is not to be limited to the exact details of operation or structure shown and described, as obvious modifications and equivalents will be apparent to one skilled in the art. | A narrow gauge, hydrostatic-drive tractor comprises an air-cooled prime mover, a Sundstrand hydraulic transmission mechanically coupled thereto, a fixed-displacement hydraulic motor hydraulically coupled to the Sundstrand transmission, an air conduit extending vertically upward from the fan housing of the prime mover for supplying ambient air to cool the prime mover, and cooling device disposed in the air conduit functioning to cool the hydraulic fluid. The motor is disposed beneath the fan housing and is coupled through a differential to drive wheels which, advantageously, have a diameter substantially the same as the width of the tractor. Advantageously, also, a manually-operated selector valve and a pressure-actuated cross-over relief valve is provided for by-passing the motor to protect the motor and to permit the tractor to be moved manually. There is also disclosed a scraping device for use with the above or like narrow gauge tractor. | 8 |
FIELD OF THE INVENTION
The invention relates to an ignition process for internal combustion engines, especially in lawn mowers or chain saws, in which a magneto induces for every engine revolution a plurality of always coherent and alternately polarized voltage half-waves, by means of which an energy accumulating means is charged and is discharged by a switch means through the primary coil of an ignition transformer. The invention furthermore relates to a condenser ignition system for internal combustion engines having a magneto inducing speed-dependent alternating voltage and a trigger system sensing the alternating voltages and serving for the actuation of a switch discharging the condenser through the primary coil of an ignition transformer; this system is especially designed for the performance of the above-named process.
BACKGROUND OF THE INVENTION
In known ignition systems more or less of the kind mentioned above (cf. U.S. Pat. No. Re. 31 837) the inner leg of a three-legged ferromagnetic iron core is surrounded by a coil arrangement. In the latter a pole wheel, which is coupled to the rotating engine shaft and which bears in a peripheral position a tangentially aligned permanent magnet, generates a series of alternating voltage half-waves. The first of these half-waves is used to charge an energy accumulating condenser and only the last half-wave serves for the operation of a thyristor discharging the condenser through the spark coil. In practice, however, it is found that in this method of procedure, the spark is fired always later with respect to the absolute angular position of the magnet pole wheel as the rotary speed increases. Explanations of this phenomenon might lie in the eddy current and hysteresis losses in the polarity reversal of the iron core that precedes the spark firing, and in the encumbrance of the entire ignition system with capacitors and a low-pass filter.
SUMMARY OF THE INVENTION
In contrast, the invention is addressed to the problem of achieving with minimal complexity a spark advance that increases with increasing rotary speed. For the solution, it is proposed in accordance with the invention, in an ignition process with the characteristics stated above, that the switching means be actuated every time that the first induced half-wave reaches a triggering threshold within each revolution.
Fundamentally, as the engine speed increases, or the angular velocity of the magneto increases, the slope of the induced voltage half-waves becomes ever greater. During the second, third, fourth etc. half-wave, however, inertia and other dynamic shortcomings of the overall system, due among other things to the circumstances mentioned above (hysteresis losses, eddy current losses, capacitances, low-pass characteristics) manifest themselves; in any case, an increasing lengthening of the said half-waves in comparison to the first half-wave occurring within a revolution can be observed. Nevertheless, the spark has heretofore always been triggered on these prolonged half-waves, because formerly the first half-wave was awaited and utilized for charging the ignition condenser. In contrast, the invention takes the unorthodox approach of using the first half-wave from each revolution for triggering the spark, regardless of the state of charge of the ignition condenser. Consequently, in the first revolution of the engine no spark is fired for lack of energy in the condenser. Not until the first half-wave induction occurs within the second revolution of the engine is the switch means actuated for the discharge of the energy accumulating means which has been charged previously by the half-waves of the first revolution. This process is repeated accordingly with each additional revolution.
Expediently, the rising portion or ascending flank of the first half wave is used to operate the switching means and fire the spark. In a further development of the process of the invention, at least one of the half-waves following the first half-wave is blocked with regard to the actuation of the switching means. This makes it possible to assure that the spark will not be triggered repeatedly within one engine revolution.
Since, as a rule, magnetos known in themselves induce a series of several voltage half-waves, the technical problem arises as to how the triggering of the spark can be made to respond precisely to the first half-wave within a revolution. In accordance with the invention this problem is solved by providing a flag which is set by the last half-wave of each revolution such that it signals the release of the spark. The flag is a special sign which signals the occurrence of a certain event, namely the end of the last half-wave of the current revolution and the approaching half-wave of the next revolution. This invention can be implemented very easily with microprocessors, since they usually have internal registers for marker bits or state bits. It is advantageous for the flag to be reset at least with the second half wave of each revolution after the spark is fired, which involves blocking the ignition. This produces the result that no spark will be fired at the wrong moment if the electromagnetic field of a spark has accidentally changed the electronically created flag in the (microprocessor) circuit.
A condenser ignition system with the features stated above, which is especially suitable for the performance of the process explained, is provided in accordance with the invention with a bistable multivibrator switching circuit which on the basis of the last alternating voltage half-wave is shifted to a state for triggering the actuation of the discharge switch during the first half-wave of the next revolution. It is desirable that the last portion of the last half-wave, i.e., its curve or end, be used for setting the multivibrator circuit to the triggering state.
Digital switches such as flip-flops are sensitive to stray electromagnetic influences which can lead to the falsification of the state of the switch. This problem is countered by an improvement of the invention according to which the flip-flop switching circuit is shifted back to its original, starting state within each revolution on the basis of the second, and in some cases subsequent, half waves of the same polarity, thereby blocking the actuation of the switch. Not until the final half-wave of the current revolution, which according to the assumptions is of opposite polarity, is the flip-flop switching circuit reset for the release of the ignition. In this manner misfiring is prevented.
This periodic resetting of the flip-flop switching circuit is advantageous especially when, in accordance with another development of the invention, it is designed as a single-flank-triggered toggle flip-flop which is reset within each revolution on the basis of the second, and in some cases subsequent, half-waves of equal polarity, and on whose dynamic cycling input the first and any subsequent half waves of the same, opposite polarity act. Toggling flip-flops, of course, invert their initial state with each positive, for example, cycle flank (cf. TietzeSchenk, "Halbleiterschaltungstechnik," 8th ed., Springer-Verlag, p. 237). If due to an external disturbance an undesired shift of the flip-flop is caused, this cannot result in a misfire on account of the above-described precautionary resetting, especially when the latter occurs before the last half-wave of a revolution.
Advantageously the flip-flop switching circuit is connected with a short-circuiting switch such that, in the flopped-back initial state, it actuates the short-circuiting switch accordingly to suppress induced triggering half-waves. How additional, superfluous sparking is avoided, especially when the engine is in a rotatory position unsuitable for this purpose, does not need further explanation. In practice it has proven desirable to insert between the output of the flip-flop switching circuit and the input of the short-circuiting switch a delay circuit, in the form, for example, of an RC low-pass filter. This causes a lag in the closing or opening of the short-circuiting switch in order to compensate undesired effects due to delayed, induced half-waves.
To facilitate the construction of the ignition system (process and arrangement) according to the invention, it is desirable that the magneto induce the smallest possible number of voltage half-waves, since sometimes only the first voltage half-wave serves to trigger the spark and the subsequent half-waves have to be used for setting and/or resetting the flag or flip-flop. It helps in this regard if the system according to the invention is combined with a magneto known in itself (cf. DE-OS 36 08 740) which has a magnet pole wheel with tangentially offset poles, coupled to the engine rotation, and a fixedly disposed coil system cooperating therewith and having a ferromagnetic iron core. The idea is embodied to special advantage if the iron core has two legs aimed at the pole wheel, only one of which is surrounded by the coil system and includes a triggering coil for deriving the pulses triggering the spark. With this magneto configuration, a first positive, a second negative, and a third positive triggering half-wave is induced per revolution. The surprisingly advantageous effect in connection with the system of the invention outlined above is based on beginning and ending each half-wave cycle with a positive half-wave; the first half-wave, after the second engine revolution, can always build upon the residual magnetism still present in the iron core and which still remains after the last half-wave of equal polarity; this results in an especially steep initial flank on the first half-wave, since no remagnetization is necessary in the iron core. Practical experiments have shown that in this case a spark advance is possible by up to 30° between 400 rpm and 12000 rpm. The middle, or second, half-wave of opposite polarity can be associated with the above-mentioned safety function, namely the compensation of disturbances of the flag or flip-flop switching circuit by resetting it.
Another improvement of the invention which is advantageous in connection with the minimum number of induced half-waves consists in the fact that the power supply of the flip-flop circuit depends on the first and in some cases subsequent half-waves. In the case of three half-waves per revolution, as in the example explained above, this means that the flip-flop switching mechanism is inactivated during the greatest part of the engine revolution and consequently cannot provoke any misfiring.
Lastly, the invention relates to an ignition system for internal combustion engines, having a magneto which induces a charging alternating voltage, depending on the rotary position of the engine, for an energy accumulating means which is discharged, preferably through the primary coil of a spark transformer, by a triggering switch operated in phase with the alternating voltage.
In the ignition systems explained above (process and arrangement) attention is paid particularly to a spark advance that increases as the speed increases. In internal combustion engines which are used, for example, in lawn mowers or chain saws, there also exists the need to prevent exceeding a top rotatory speed.
To solve the problem of speed limiting, in the case of an ignition system with the above-named features, it is proposed in accordance with the invention to provide a timer module which reacts to the alternating voltage with the production of a blocking signal to the firing switch, and keeps the blocking signal active during a time interval which is selected on the basis of a top speed limit for the engine.
Periodically with every engine revolution, when a certain angular position is reached, a series of alternating voltage half-waves are triggered (as described in the older citation described above) which serve for the charging of the energy accumulating means and/or the triggering of the spark through the spark switch that discharges the energy accumulating means. On the basis of the occurrence of the alternating voltage, the timer module is simultaneously set up or started for the generation of a preset constant time span. With increasing rotatory speed, the period with which the alternating voltage regularly occurs becomes shorter, but the time span generated by the timer remains constant. If the period for the regular occurrence of the alternating voltage falls below the generated time span, ignition is blocked on account of the blocking signal given by the timer to the spark switch, so that no further increase of the speed is possible. Not until the end of a generated time span does the timer inactivate the blocking signal, thereby again releasing additional ignitions. The latter take place with the renewed occurrence of induced alternating voltage and at the same time the timer is started for the resumption of the generation of the preset time span or period, with the simultaneous setting of the blocking signal.
In further development of this ignition system according to the invention, components such as preselecting counters, time switches or monostable multivibrators, known in themselves and marketed at low cost, are suitable to serve as the timer, and each of them is wired so that they are resettable to their initial or starting state by means of the alternating voltage. On the other hand, it is also within the scope of the invention to design the timer in software, namely to implement it in a microcomputer as a software routine, which can be done using a programmable counter component known in itself; to permit the resetting and starting of the timer in synchronism with the alternating voltage, sensing means known in themselves (threshold comparators, A/D converters) can be provided to detect the occurrence of the alternating voltage.
In synchronizing the operation of the timer with the alternating voltage the problem arises of processing it to make it suitable for detection by the timer and/or to shape it for signal detection. To solve this problem, in further development of the invention, a matching module or network is proposed by means of which one or more alternating voltage half-waves are selected for each engine revolution, rectified and/or inverted as necessary, and fed to the timer in its reset input.
Advantageously, every half-wave, on its way to the timer starting or resetting input, passes through at least one delay circuit which produces a time-delay corresponding to the minimum actuating time of the spark switch. The advantage is that any incorrect starting or resetting of the timer and the premature cut-out of the spark switch which it might entail is largely prevented; spikes originating in the firing of the spark cannot reset the timer to block the ignition until the energy accumulating means for the ignition has been sufficiently discharged, for which the spark switch requires a minimum amount of time. Thus the provision of time-delay circuits serves to improve the reliability and safety of the ignition.
In order to assure a rapid, virtually undelayed spark in connection with time-delay circuits in the low or medium speed range, provision is made according to a further development so that at least one half-wave per engine revolution, preferably the first half-wave of the alternating voltage, will be fed to the timer additionally with a logical AND configuration to its blocking signal output. If the timer has withdrawn the blocking signal due to the expiry of the time which it has generated, the information resulting from the alternating voltage half-wave is weighted or rated as a logical "null" due to the AND configuration, so that the timer will not be restarted or the blocking signal to the spark switch will not be reset. If the gas engine is running close to its upper speed limit, data resulting from half-waves are weighted or rated as logical "one" so that the starting or resetting input of the timer and hence the blocking signal become reactivated immediately. If the magneto produces more than two half-waves per engine revolution, the time intervals between the second and subsequent half-waves become longer than between the first and second half-wave on account of hysteresis losses. This phenomenon becomes especially apparent in the low or bottom speed range of the engine. In order to span the said greater time interval, according to an advantageous further development of the invention, a memory element, for example a flip-flop, is provided which stores a mark signal fed to the timer to reset it, and it is charged by one half-wave and erased by another either preceding or following half-wave. In this manner the resetting information for the timer resulting from the second and, in some cases, subsequent half-waves is retained until the directly adjacent half-wave arrives; during the time interval between the two successive half-waves the timer is held always in the resetting or starting state, so that the blocking signal remains suppressed and the ignition can freely proceed.
For the achievement of compact construction for use in small engines it is advantageous if, according to a further development of the invention, the matching module, including the delay circuits, AND gates and/or memory element, if any, is combined structurally with the timer in an integrated circuit. To permit "on-site" use, where there is no possibility of connection to power mains, another desirable further development consists in providing an additional energy accumulating means to supply power to the timer module and/or to the matching module or integrated circuit if used, which is charged by the alternating voltage induced by the magneto. Since in this manner the engine power is used indirectly for power generation no separate battery element is necessary.
In the synchronization of timer operation and induced alternating voltage the problem arises of converting the alternating current and its half-waves into signals usable by the timer, which are unipolar with respect to reference potential for the use of known digital technology. In this regard, a further development of the invention consists in feeding to the matching module alternating voltage half-waves which are taken both from the one pole and from the opposite pole of an induction coil. Thus the voltages induced in the induction coil with opposite signs are given identical directions in relation to the matching module and its reference potential. Alternatively, the negative alternating voltage half-wave can be fed to the matching module through an inverter, for example in the form of a pnp transistor in the emitter circuit.
To enable the timer to act on the spark switch with its blocking signal, a blocking circuit is connected to the output of the timer, according to a further development of the invention, which, when operated or actuated by the blocking signal short-circuits the actuating input of the spark switch to the ground. If alternating voltage then reaches the actuating input, the latter, too, is short-circuited and thus cannot produce a spark.
Before the speed limiting by the timer starts, a retardation of the spark with respect to a reference rotatory position of the engine (e.g., top dead center) is to take place, this can be performed within the scope of the invention as follows: a delay module, in the form for example of an RC low-pass circuit, is made to precede directly the response, start and reset input of the timer if any, whose time constant governing the retardation is selected with an eye to the desired retardation of the moment of ignition and acts directly in the vicinity of the top rotatory speed of the engine. In this vicinity, if upon the occurrence of alternating voltage the time period or delay time generated by the timer has already run out except for a small residual time, the delay circuit delays the entry of a reset or start signal into the timer beyond the remaining time period, so that a retarded spark can still be fired.
Advantageously a pulse or cycle generator is provided as a time reference for the timer module, and its cycling or pulse output is fed, after a logical AND connection with the blocking signal of the timer module, to a corresponding counting means. Especially when the timer module is embodied in a counter module, the blocking signal produced by it can also prevent entry of the pulses from the cycle generator which are to be counted, inasmuch as the AND gate serving as a gate to the counter input is blocked.
To stabilize the idle speed of the engine a reduction of the spark advance (see the citation given in the beginning) is advantageous. In this regard a further development according to the invention consists in the fact that the timer module reacts to the alternating voltage with the production of an additional, separate delay signal for the delayed actuation of the spark switch; this delay signal is produced for the duration of a second, longer time interval which corresponds to a bottom limit of the rotary speed, preferably the idle speed, of the engine. In this manner, at the bottom speed limit, especially the idle speed, a break in the ignition curve of the engine is produced, which has a desirable effect on stability in idling. The delayed actuation of the spark switch can be achieved advantageously with a delay circuit which is activated by the delay signal from the timer. The induced alternating voltage is then fed with a delay through the delay circuit, e.g., an RC low-pass filter, to the actuating input of the spark switch to trigger it. Especially when the timer module is designed on the basis of a preselecting counter module, the preselected number at which the delay signal is produced when it is reached must be higher than the preselected number for the blocking signal. Therefore the timer module, especially the counter module, must not stop counting when the preselected number for the blocking signal is reached. A further development of the invention provides for this by the fact that the cycling or pulse output of the said cycling or pulse generator has an AND configuration only with the delay signal.
Additional features, details and advantages of the invention will be found in the following description of preferred embodiments of the invention, with the aid of the drawing, wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an axial view of a construction of the magneto which is advantageous for the invention,
FIG. 2 shows a circuit embodiment of the invention,
FIGS. 3(a-e) show voltage/time diagrams with regard to voltage half-waves induced by the magneto, and diagrams of input and output signals of a flip-flop circuit used in accordance with the invention,
FIG. 4 shows an additional circuit embodiment of the invention,
FIG. 5 shows still another circuit embodiment of the invention,
FIGS. 6(a-c) show the manner of the operation of the circuits of FIG. 4 and/or FIG. 5, with the aid of the pulse diagrams a)-c),
FIG. 7 shows another modified circuit embodiment of the invention, and
FIG. 8 shows the ignition adjustment curve for the operation of the internal combustion engine, resulting from the circuit variant of FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The magneto represented in FIG. 1 has a pole wheel 1 which is rotated in the counterclockwise direction 2 by the engine (not represented). On its outer circumference there is a permanent magnet 3 with tangentially offset poles N and S, which magnetize correspondingly arranged pole shoes 4. In the rotation 2, this system of magnets 3, 4, is moved past a U-shaped ferromagnetic iron core 5 whose first leg 6 is surrounded by a coil system L1, L2, L3, L4, and whose second leg 7 has no coils. The coil system consists of four coils L1 to L4 arranged concentrically about the first leg 6. Their operation will be apparent from the explanations given with the aid of the additional figures showing circuits and signal/time diagrams.
Referring to FIG. 2, the first charging coil L1 charges a spark condenser C1 through a full-wave rectifier G1 in a bridge circuit, for example. The second coil L2 and third coil L3 together form the primary and secondary windings, respectively, of a spark transformer 8. The primary coil L2 is in series with the spark condenser C1 upon whose discharge through a switch Thy in the form of a thyristor at the output of the spark transformer 8 a high-voltage spark signal 9 is formed. The control or actuating input 10 of the switch Thy is connected to the output of a trigger system 11 (indicated in broken lines) with which a fourth coil L4 is associated as the trigger coil. Furthermore, the control input 10 of the switch Thy is grounded through a protective resistor R10 and a protective diode D5 connected in parallel. In the coil system L1 to L4, coherent and alternately polarized voltage half-waves are produced in a known manner, as represented in FIG. 3, diagram a. A cutout switch 12 to ground is connected in parallel with the trigger coil L4, and short-circuits the trigger coil L4 when closed. Between the trigger coil L4 and the control input 10 of the switch Thy, a diode D2 admitting only positive half-waves is connected in series with a current limiting resistance R1. Between this diode D2 and the current limiting resistance R1 a parallel circuit consisting of the resistor R9, the polarized condenser C2 and the Zener diode D3 is connected to ground. This parallel-connected network serves on the one hand to smooth pulses originating from the trigger coil L4, and on the other hand for voltage stabilization.
Two inputs 14, 15, of a bistable multivibrator 16 are connected to the output of the trigger coil L4, parallel to the input 13 of the trigger system 11. The heart of the bistable multivibrator is formed by an integrated-circuit data flip-flop 17 with a positively flank-triggered cycling input Cl which is operated as a toggling unit by feeding its inverting output Q back to its data input D. The voltage supply to the input U B of the flip-flop 17 is derived from the first input 14 of the bistable multivibrator 16 as follows: A polarized condenser C3 is charged with respect to ground through a diode D4 admitting only the positive voltage half-waves from the trigger coil L4; it then constitutes the supply voltage U B to the flip-flop 17. To its cycling input C1 is connected the output of an inverting element formed by an npn transistor T2 in a common-emitter circuit whose collector is connected via the collector resistor R5 to the power supply potential of flip-flop 17 and of the power supply condenser C3. The control or base signal of the transistor T2 is fed through a voltage divider R3, R4, connected between the ground and the Zener diode D3 of the trigger system 11.
The reset input R of flip-flop 17 is connected to the output of another inverting circuit element consisting of the pnp transistor T1 in a common-emitter circuit with grounded collector resistor R7. The control or base input of this pnp transistor T1 is controlled through a voltage divider R2, R6, which is connected at one end thereof to the output of the trigger coil L4 and at the other end to the power supply from the power supply condenser C3. Its power supply potential is fed to the emitter of the pnp transistor T1.
The inverting output Q of the flip-flop 17 actuates through a delaying RC low-pass filter R8, C4, a short-circuit switch constituted by an npn transistor T3 in a common-emitter circuit, which then short-circuits to ground the output or control input 10 of the switch Thy.
For the manner of operation of this embodiment of an ignition system according to the invention, reference is made to the signal/time diagrams a) to e) in FIG. 3:
According to diagram a), when the north pole N of the permanent magnet 3 moves past the first leg 6 of the U-shaped iron core 5 bearing the coil system including the trigger coil L4, a voltage half-wave I of positive polarity is induced in the trigger coil L4. After leaving the first leg 6 the north pole N is moved by the rotation 2 of the pole wheel 1 to the second, unwound leg 7, while the south pole S is driven past the first leg 6. This results in a complete reversal of the magnetism of the iron core 5, whereupon the second voltage half-wave II of opposite polarity and greater amplitude is formed. As the north pole N comes out of reach of the second leg 7 as rotation 2 continues, the second leg 7 is then magnetized by the south pole S of the permanent magnet 3, and again a change of the magnetic flux through the coil arrangement is produced; that is, an additional voltage half-wave III is induced, whose polarity is the opposite of that of the second voltage half-wave II. When, due to rotation 2, the south pole S comes out of the reach of legs 6 and 7 of the U-shaped core 5, a residual magnetism of positive polarity remains in the core due to the magnetization hysteresis. After one complete revolution of the pole wheel 1, the above-described cycle of voltage half-waves I-II-III with the period T is repeated. As explained above, the dynamic characteristic of the ignition system leads to a lengthening of the second half-wave II and third half-wave III, which is manifested by a delayed passage through the trigger threshold U Tr with the delay s by the initial flank of the third half-wave III.
According to the present embodiment, the trigger coil L4, on the ascending flank of the first half-wave I, supplies upon passing through the trigger threshold U Tr a firing pulse through the diode D2 and the output resistor R1 to the control input 10 of the switch Thy. In the first rotation of the pole wheel 1, the spark condenser C1 is not yet charged, and therefore in the first passage of pole wheel 1 past the coil system no spark is fired, and instead the spark condenser C1 and the power supply condenser C3 are charged (cf. diagram b). The subsequent second half-wave II of negative polarity in the trigger coil L4 makes the pnp transistor T1 conductive through the resistor R2 of the voltage divider R2, R6, so that the flip-flop 17 is reset (cf. diagram c in FIG. 3). Thus the inverting output Q of the flip-flop 17 goes to positive potential, so that the short-circuiting switch is closed by the transistor T3 in a common-emitter circuit (cf. diagram e) on the basis of the second half-wave II. In this situation any operation of the switch Thy to produce the spark 9 is impossible, and especially the following third half-wave III from the trigger coil L4 cannot fire a spark. The third half-wave III, however, actuates the inverting circuit element with the npn transistor T2 through the gate diode D2 and the input voltage divider R3, R4, while the cycling input Cl of the flip-flop 17, which previously rose to positive potential with the second voltage half-wave II, is reduced to ground potential. With the descending flank of the third half-wave III, the actuating voltage of the transistor T2 established by the voltage divider R3, R4, falls short and the transistor then blocks. Thus, through the collector resistor R5 of circuit element or transistor T2 a positive potential is applied to the cycling input Cl of flip-flop 17, and so an ascending flank is produced (cf. diagram d) for the signal curve at the cycling input Cl. On account of the ascending flank of the cycle the inverting output Q of the flip-flop 17 changes its level, which previously was at a positive potential, to a low potential. As a result the short-circuit switch T3 is ungrounded and the first half-wave I within the first revolution is not shorted but reaches the control input 10 of the switch Thy. This signifies that the spark 9 is fired with the ascending flank of the first half-wave I, and the spark condenser C1 is discharged through the primary coil L2 of the spark transformer 8. The spark forming at the spark plug (not shown) might undesirably shift the flip-flop 17 to another state. This is countered, as already described, by the reset pulse at input R of the flip-flop 17 on the basis of half-wave II immediately before it is set to fire the spark (cf. especially diagrams a and c). Since the power supply for the bistable multivibrator 16 is tied to the occurrence of the three voltage half-waves I, II and III, it decreases during the period of the last half-wave III and the first half-wave following within the next revolution; thus the bistable multivibrator is inactivated and cannot cause any ignition for periods outside of the voltage half-waves I to III.
The idea of the invention goes beyond the special embodiment just described. The operations of the above trigger system 11 and/or of the bistable multivibrator 16 can be performed by appropriate software, taking place in a microcomputer, especially one with flag registers or corresponding reserved memory cells. The half-waves from the trigger coil could be detected by an analog-to-digital converter in the microcomputer. Also, a fixed permanent magnet can be provided in the magneto instead of a rotating permanent magnet, while instead of the pole wheel a yoke wheel is used with projecting tooth-like segments for completing the magnetic circuit.
According to the modification of FIG. 4, the control or actuating input 10 of the spark switch Thy is connected indirectly through the ohmic resistor R22 and the diode D21 next to it to one pole terminal of the fourth trigger coil L4--the one serving to trigger the spark 9--whose opposite pole terminal is at the reference potential or ground. On account of the diode D21 admitting only positive alternating voltage half-waves, the switch Thy is closed through its actuating input 10 only in the case of half-waves in the trigger coil L4 which are induced positively with respect to the reference potential. From these half-waves, furthermore, a supply voltage +U is derived for the integrated circuit IC through an additional diode D22 admitting positive half-waves, in conjunction with the following parallel circuit of the polarized supply condenser C22 and the voltage stabilizing Zener diode D23. The integrated circuit IC with its additional supply input -U is at the same reference potential as the trigger coil L4 and has an input POS1 for positive alternating voltage half-waves from the trigger coil L4 and an input POSN for negative ones. The input POS1 is connected through the ohmic resistance R25 to the cathode of the first-mentioned diode D21 admitting positive half-waves. Alternating voltage half-waves induced negatively with respect to reference potential or ground are inverted by means of an inverting circuit 211 and fed inverted to the second-mentioned circuit input POSN. The inverting circuit 211 in the example given in the drawing is formed by the pnp transistor T21 disposed in the emitter circuit, and is controlled from the signal pole terminal of the trigger coil L4 through a resistor R23 upon the occurrence of negative half waves at its base, and at the collector side forwards them to the input POSN; the resistor R24 between collector and ground serves to produce the corresponding voltage drop.
Important functional units of the integrated circuit IC are the matching module 212 and the preselecting counter Z1 serving in the example as the timer 214. The positive half-wave input POS1 is fed within the matching module 212 to the reset input of an RS flip-flop FF1 and to the inputs of an OR gate OR1 and an AND gate UND1. The input POSN for (originally) negative half-waves leads through a time delay circuit t1 to the set input S of the RS flip-flop FF1. Its output Q is connected to the second input of the previously mentioned OR gate OR1. The second input of this gate OR2 is directly connected to the output of the above-mentioned AND gate UND1, which connects the output Qx of the preselect counter Z1 with the signal from the input POS1.
The second-named OR gate OR2 forms, for the integrated circuit IC, an output A which is connected through an external delay circuit 213 (in this example an RC low-pass filter with the resistance R21 in series and the grounded condenser Cx) to an additional input B of the integrated circuit IC. Input B serves to produce a start and reset signal for the timer module 214 or preselecting counter Z1. The timer module 214 includes, in addition to the preselecting counter Z1, a second AND gate UND2 by means of which the pulse series corresponding to a counting frequency f z of an external cycle generator 214 has an AND connection to the output Qx of the preselecting counter Z1 and is fed to its counting input CNT. Therefore the counting process is stopped when the preselecting counter Z1 detects through its input CMP a positive result of comparison with an externally set preselected number VWZ and thereupon inactivates its output signal Qx or resets it. The preselected number VWZ permits a rough setting of the preselecting counter Z1 by establishing its counting steps; the fine setting can be made by varying the counting frequency f z from the cycle generator.
The output signal Qx also forms the blocking signal output Out of the integrated circuit IC which controls the blocking switch T22, formed from an npn transistor in a common-emitter circuit. The blocking switch T22, when actuated by the activated blocking signal output Out, connects the actuating input 10 of the spark switch Thy to the ground or reference potential to prevent ignition.
The circuit modification shown in FIG. 5 is a modification of the one in FIG. 4 as follows: On the one hand negative voltage half-waves are obtained by taking them directly from a pole terminal 216 of the charging coil L1, followed by delivery in a direction that is positive in relation to reference potential, to the corresponding circuit input POSN as positive signals for the matching module 212 connected to its output. If voltage half-waves of inverse polarity occur at the source point or pole terminal 216 of the charging coil L1, they are shorted to ground by the diode D24. Consequently the transistor T21 and the resistor R24 in FIG. 4 can be omitted. On the other hand, the preselecting counter Z1 with AND gate UND2 used in FIG. 4 are here replaced by a monostable multivibrator MF to form the timer module 214. The monostable multivibrator MF is wired externally with a resistance R M and a condenser C M by the sizes or settings of which the duration of the unstable state of the monostable multivibrator and hence the time interval generated by the timer for the activation of the blocking signal output Out can be selected. Lastly, the external delay circuit (cf. No. 213 in FIG. 4) is omitted and instead the output of the OR gate OR2 is delivered directly to the start input of the monostable multivibrator MF and timer 214.
The operation of the circuit of FIG. 4 will now be explained in reference to the signal/time diagrams in FIG. 6.
According to diagram 6a, when the north pole N of permanent magnet 3 moves past the first leg 6 of the U-shaped iron core 5 (see FIG. 1), which is wound with the coil system including the trigger coil L4, a voltage half-wave I' of positive polarity is induced in the charging coil L1 and trigger coil L4. When the north pole N, after leaving the vicinity of the first leg 6 due to the rotation 2, passes the second, unwound leg 7, the south pole S at the same time comes into the vicinity of the first leg 6. This leads to a complete inversion of the magnetism of iron core 5, whereupon the second voltage half-wave II' of opposite polarity and greater amplitude is produced. As rotation 2 continues, when the north pole N leaves the vicinity of the second leg 7, which the south pole S then magnetizes accordingly, a change of the magnetic flux through the coil system is produced; this leads to the induction of an additional voltage half-wave III' whose polarity is the opposite of that of the second voltage half-wave II'. On account of the necessary magnetic inversions the voltage half-waves II' and III' are farther apart in time from one another than the voltage half-waves I' and II' (not shown). After one complete revolution of the pole wheel the above-described voltage half-wave cycle I'-II'-III' is repeated with the period T.
The unipolar pulse series at the circuit input POS1 corresponds to the positive voltage half-waves I' and III', and the similar pulse series at the circuit input POSN corresponds to the negative half-wave II'. In the example given in Diagram a, upon the occurrence of the first POS1 pulse the blocking signal Out had already been reset, i.e., to logical "0," on account of the expiration of the timer's time interval. Now the first POS1 pulse, after passing through the OR gate OR1, the delay circuit t2 and the second OR gate OR2, produces the resetting and starting of the timer 14 (cf. FIG. 4). According to Diagram 6a, this first POS1 pulse therefore causes the blocking signal Out to be set with the corresponding time delay. Therefore the spark previously triggered by the first POS1 pulse is immediately suppressed.
According to Diagram 6b, the rotatory speed of the gas engine has increased, so that the alternating voltage half-waves I', II' and III' occur with the period T' shortened in comparison with Diagram 6a. This period is so short that, when the first POS1 pulse occurs, the preselecting counter Z1, in counting off the pulses from the cycle generator 215 which are based on the counting frequency f z , has not yet reached the preselected number VWZ (cf. FIG. 4) for speed limiting, i.e., it continues to run. So it is then reset or started, as the case may be, by the three half-waves I', II', III', via the inputs POS1 and POSN, the memory unit FF1 with time delay circuit t1 and the gates OR1, OR2 with time delay circuit t2. After the third half-wave III the preselecting counter Z1 resumes counting. Consequently, in the preselecting counter Z1, when the period T' of the alternating voltage cycle I'-II'-III' is exceeded, the counting operation prevails, so that the blocking signal Out continually prevents ignition.
According to Diagram 6c, the gas engine is in a speed range that is between that of Diagram 6a and that of Diagram 6b; in other words,
T'<T"<T.
In that case the corresponding period T" exceeds the time interval produced by the timer by so few counting steps that the blocking signal Out is still withheld for the duration of the first POS1 pulse of a period T". On account of the delay circuit 213 of FIG. 4, this first POS1 pulse is bridged over with a time delay to the start or reset input of the preselecting counter Z1 and timer 214. The first POS1 pulse cannot immediately reset the timer 214 and preselecting counter Z1 via the AND gate UND1, because it is delayed by the delay circuit 213. When the preselecting counter then reaches its final value (preselected number VWZ), while the first POS1 pulse is still present, the blocking signal Out becomes inactive and the spark switch Thy can be actuated. The spark therefore occurred a certain time after the arrival of the first POS1 pulse. Since this pulse is in a fixed relation to the crankshaft position of the gas engine, the spark is retarded in accordance with Diagram 6c. The time delay by the delay circuit 213 is sufficient so that the spark 9 started upon the occurrence of the first POS1 pulse can fully develop until it is then terminated at the end of the time delay by (another) occurrence of the blocking signal Out.
The modification circuit in FIG. 7 differs from the one in FIG. 4 in that the functions of the timer module 214 are expanded: The preselecting counter 21 used in the example is in active connection through its comparing input CMP to an additional externally set preselected number VWZy. If, in counting the pulses or count frequency f z , a positive comparison result with regard to the second preselected number VWZy arrives from the cycle generator 215, this is indicated by the setting of a second signal output Qy of the counter circuit Z1; this takes place similarly to the setting of the first signal output Qx with regard to the first preselected number VWZ. The second output signal Qy is formed by the delay signal Out2 produced by the timer module 214, and in the set or active state it activates an additional delay circuit 218 consisting of the resistances R 2 , R s , the condenser C S and the switching transistor T S . For this purpose the delay signal output Out2 is connected to the base of the switching transistor T S . If the latter is actuated by the delay signal Out2, it grounds the parallel circuit consisting of resistance R S and the condenser C S . The condenser C S then forms together with the resistance R 22 an RC low-pass filter through which positive voltage half-waves issuing from the trigger coil L4 and passing through the diode D21 reach, with a delay, the actuating input 10 of the spark switch or thyristor Thy. Thus the discharge of the storage condenser c1 and the spark 9 produced thereby is retarded in accordance with the time constant of the RC low-pass filter or delay line 218.
This can be utilized to advantage for stabilizing the idle speed of the gas engine, if the preselected number VWZy is greater with respect to the second counter output Qy than the preselected number VWZ with respect to the first counter output Qx. In other words, if
VWZy>VWZ.
But to prevent the counter module Z1 from being stopped on the basis of this circumstance when the smaller preselected number VWZ is reached, as it is in FIG. 4, so that the specified production of the delay signal Out2 by the second counter output Qy will still be assured, the latter is tied in a logical AND configuration to the counting frequency fz from the cycle generator 215 through the gate UND2.
The manner of operation of the circuit modification in FIG. 7 will be further explained with the aid of FIG. 8, which shows the spark angle advance beta in degrees over the speed in revolutions per minute. Here the preselected number VWZy is adjusted so that the delay signal Out2 is "low", i.e., inactive, up to a speed of about 2000 rpm. At about 2000 rpm the second output of the counter Z1 becomes "active high," i.e., is set, and the additional delay circuit 218 is inserted by means of the inserted switching transistor T s . This produces a break in the ignition timing curve at 2000 rpm, which serves for the stabilization of the idle speed. The advancing of the spark thus reduced increases with increasing speed until 12,000 rpm is reached. This speed corresponds to the value of the first preselected number VWZ, at which, when it is reached, the spark 9 is blocked, as explained above. The second preselected number VWZy can also be achieved by the use of internal divider stages within the counter module Z1. In this manner no separate input for the second preselected number is necessary. | An ignition method and system for internal combustion engines, especially in lawn mowers or chain saws, in which a magneto induces a plurality of alternating voltage half-waves for each engine revolution to charge an energy-storing element and to discharge it by a switch controlled by the primary coil of an ignition transformer. The switch is actuated when the first half-wave of each revolution reaches a trigger threshold. The ignition system induces the charging alternating voltage dependent upon the rotary position of the engine for the energy storage element and for discharging it via the switch for firing the spark synchronously with the alternating voltage. The system has a timer module which responds to the alternating voltage by producing a signal to block the ignition switch for the duration of a time interval which corresponds to a top speed limit of the internal combustion engine. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Patent Application Serial No. 60/352,463, entitled “BOW-MOUNTED ARROW QUIVER WITH STACKED ARROW MOUNTING,” which was filed Jan. 28, 2002, and which is hereby incorporated herein by reference in its entirety. This application is also related to U.S. Pat. No. 6,390,085, entitled “ARROW QUIVER FOR RETRACTIBLE-BLADE BROADHEADS,” issued May 21, 2002, which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
In the earlier and related patent referenced above and incorporated herein, a novel new arrow quiver configuration is disclosed and claimed which is specially suited for use with the retractable-blade arrowheads known as “mechanical” broadheads, in which the blades are pivotally mounted and arranged to be retracted prior to shooting and interlocked or indexed in the retracted position until impact, whereupon they spring forward to strike the target with increased effect. As there disclosed, the earlier design for such a quiver included a pair of resilient arrow holders mounted in spaced relation upon a supporting spine or stem member, together with a generally cup-like broadhead shield mounted at the top of the stem member which contains an arrow tip support inside the broadhead shield. The tip support has a series of laterally aligned specially configured recesses or pockets for receiving the tips of the broadheads while maintaining the retracted broadhead blades out of contact with all other nearby surfaces, thereby preventing premature opening of the retracted, spring-loaded mechanical broadhead blades.
In this arrangement, each of the spaced arrow holders included a series of arrow shaft-receiving apertures arranged in a row, and the apertures of the two arrow holders were aligned with one another and with a designated one of the broadhead tip pockets. Therefore, each aligned pair of arrow holder apertures served to guide an arrow disposed therein directly into the designated tip pocket for that arrow, for easy and accurate loading of the arrows into the quiver, and the tip pockets served as pivotal levering points which allowed easy removal of the arrows by lifting them upward from their arrow holders.
SUMMARY OF THE INVENTION
In accordance with the present invention, a further improvement is provided for the above-mentioned concept and structure, in accordance with which a larger quantity of arrows may be safely and satisfactorily retained without mutual contact or other impact such as would prematurely trigger the closed mechanical blades, and also by which a plurality of arrows with different shaft diameters may be so held and carried, thereby adding greater versatility and operational flexibility to the resulting quiver.
Briefly stated, the present invention provides a new form of bow-mounted arrow quiver which will safely and satisfactorily carry a plurality of different kinds of broadhead-tipped arrows, particularly mechanical broadhead arrows, regardless of shaft size (diameter), while maintaining each different broadhead out of contact with the others contained within the broadhead shield.
In a more particular sense, the invention provides a bow-mounted arrow quiver having a pair of mutually spaced arrow-holders which have a plurality of differently sized arrow shaft-receiving apertures, arranged in sets containing at least two such differently sized apertures or passages which communicate with one another through a connective slot, whereby an arrow shaft of either larger or smaller diameter may be contained in any given such set of receiving apertures or passages by simply moving it to the most appropriately sized receiving aperture or passage. Further, the invention provides a new and novel form of arrow tip-receiving pocket arrays mounted inside the broadhead shield, which is specially configured to receive only the forward part of an arrowhead while maintaining the blades out of contact with all other adjacent structures, such tip pockets being disposed in an effective mutually-spaced two-dimension array and also preferably being advantageously formed in a one-piece support member which also may provide a liner for protectively covering the adjacent interior sides of the broadhead shield.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing the overall nature of the present invention;
FIG. 2 is an enlarged elevational view showing the structure of the arrow holder mounted at the bottom of the quiver;
FIG. 3 is an elevational view similar to FIG. 2 but showing the arrow holder mounted near the broadhead shield;
FIG. 4 is a fragmentary sectional plan view showing a plurality of arrows mounted in place upon the quiver, further showing arrow tips engaging the tip pockets inside the broadhead shield;
FIG. 5 is a fragmentary, enlarged sectional elevation taken along the plane perpendicular to that shown in FIG. 4;
FIG. 6 is an end elevational view showing the arrangement of the tip pockets inside the broadhead shield and further identifying plane V—V utilized in FIG. 5; and
FIG. 7 is an enlarged side elevational view showing a single tipped pocket.
DESCRIPTION OF PREFERRED EMBODIMENTS
U.S. Pat. No. 6,390,085 generally describes a bow-mounted quiver device, which lack the particular features disclosed herein. Basically, and with reference to FIG. 1 herein, the quiver device 10 comprises a domed or cup-shaped broadhead shield 12 mounted atop a spine-like stem 14 which carries a pair of spaced arrow holders 16 and 18 . Each of these constitute a resilient rubber-like member having a series of laterally adjacent but mutually spaced slots leading into openings, which receive and retain the shaft of an arrow, to thereby mount it upon the quiver, with the arrangement being such that the shaft-receiving slots in each of the arrow holders 16 , 18 are correspondingly aligned so that each pair of them retains the shaft of a single arrow and holds it in place with its broadhead disposed inside the shield 12 . As will be understood by those skilled in the art, the quiver 10 also includes a mounting bracket structure 20 , which is unnecessary to describe herein since already shown in the inventor's prior U.S. Pat. Nos. 4,156,496; 5,265,585; and 5,566,665 and now well known in the art.
FIGS. 2 and 3 show further details of the two arrow holders 16 and 18 . The holders 16 and 18 are mounted in the same manner on the quiver stem 14 as those of U.S. Pat. No. 6,390,085. In accordance with the present invention, however, each of the arrow holders 16 , 18 is made to be a compound device, i.e., each of the arrow-receiving slots 116 , 216 , 316 , 416 , and 118 , 218 , 318 , 418 defines two (or potentially more) differently-sized arrow shaft-retaining passages 116 a , 116 b , 118 a , 118 b , etc. More particularly, the lower such passages 116 a , 118 b , etc., are smaller in diameter than the upper passages 116 b , 118 b , etc., and each such set in each arrow holder is interconnected by a narrower opening extending between them. The lower such passage is sized to receive and lightly grip carbon-shaft arrows, while the upper passage holds the new carbon-aluminum shafts and the standard aluminum shafts, which are larger in diameter. For example, the smaller aperture 116 a may be on the order of 0.20 inches, and the larger apertures 116 b on the order of about 0.28 inches in diameter.
The resiliency requirements of a well-functioning arrow holder do not permit use of a single-diameter passage/aperture to accommodate these differing arrow shaft diameters and it has, until now, been standard practice to change the arrow holders on an existing quiver to accommodate whichever size arrows the hunter wishes to use at a given time. This is clearly an inconvenience, and makes it impossible to load and carry an assortment of different types of arrows at the same time. The present configuration provides a very effective solution to this problem and inconvenience, while at the same time providing a quiver that will properly and effectively mount twice as many arrows as those generally used heretofore.
It should be pointed out that the arrow holders 16 , 18 and their respective arrow-receiving passages 116 a , 118 a , etc., are arranged and mounted upon stem 14 so as to mutually align each of the sets of passages 116 a , 118 a , 116 b , 118 b , etc., between the two spaced arrow holders, so that each such set of aligned passages holds an individual arrow in a properly spaced and well-organized disposition. To accommodate such a dual or compound array of arrows, a corresponding array of particularly configured and located tip pockets 22 , 24 , 26 , 28 , and 30 , 32 , 34 , and 36 , respectively (FIGS. 4, 5 , 6 , and 7 ) are provided in broadhead shield 12 . As illustrated in these figures, the tip pockets 22 - 36 inclusive are formed in the bottom of a liner/insert 38 that mounts inside the outer shell-like part of the broadhead shield 12 , fitting snuggly inside the latter. The liner/insert 38 preferably comprises a dished member with a generally flat or planar bottom/base portion 40 that is preferably a one-piece molded part, formed from a moderately flexible rubber-like material. In the most preferred form, base portion 40 comprises a flat end wall 42 having a series of thickened protrusions 44 on its rear surface in which the tip pockets 22 - 36 inclusive are formed, with a series of narrow ribs 46 extending laterally from each tip pocket protrusion 44 outwardly to the edge of the shield 12 , to provide additional stabilization and support for the end of the liner insert.
As may be seen from FIGS. 4, 5 , and 6 , the tip pockets 22 - 36 inclusive are arrayed in two superposed sets of four, providing sets of vertically aligned top and bottom pockets (e.g., 22 and 30 , for example) at each of four different locations. These locations match the arrow alignment provided by the arrow shaft retention passages (e.g., 116 a , 118 a , and 116 b , 118 b , for example) provided in the two arrow holders 16 , 18 (see FIGS. 2 and 3, as well as FIGS. 4, 5 and 6 ). Thus, each individual arrow mounted in the quiver on arrow holders 16 , 18 will automatically be aligned with a corresponding tip pocket, such that by initially mounting a given arrow in a given set of retention passages in the arrow holders 16 , 18 , with the broadhead either outside the entrance of broadhead shield 12 , or only partially inserted into the latter, the arrow may then be slid forwardly (i.e., upwardly as mounted on the bow) toward and into the broadhead shield 12 , and the pointed end extremity of the broadhead 52 will automatically be guided directly into a corresponding tip pocket 22 , etc.
As in the case of U.S. Pat. No. 6,390,085 referenced above, each of the tip pockets 22 - 36 inclusive (which are all identical) are particularly formed to receive only the extending pointed portion of the broadhead 52 , leaving the folded or retracted blades (e.g. 54 ) out of contact with all parts of the liner/insert 38 , and the spacing of arrows provided by the arrow holder passage 116 a , 118 a , etc., and disposition of the tip pockets 22 - 36 inclusive is such that no two adjacent arrowheads make contact with one another, particular the folded blades thereof. For example, the depth of the tip pockets should be limited to accomplish this, e.g., not exceeding about one-fourth of an inch in relation to current broadhead dimensions. Thus, undesired rattles or the like and inadvertent release of the folded and spring-loaded broadhead blades is prevented at all times. Further, each of the tip pockets 22 - 36 inclusive is preferably shaped in the manner illustrated in FIGS. 4-7 inclusive, being generally oval-shaped and laterally elongated, with angularly sloping (e.g., tapered) sides generally emulating the conically tapered point on the broadheads 42 , but the end extremity of the tip pockets is preferably flat, as illustrated. Thus, slight variations in arrow alignment due to reasonable manufacturing and fabrication tolerance variations are readily accommodated by each of the tip pockets, which are preferably somewhat larger in cross-section than corresponding parts of the broadhead, which they receive.
It will readily be seen from the foregoing that a novel and inventive improvement has been provided, by which a plurality of arrows having different shaft sizes may easily and securely be mounted in the same quiver, with the tip of each separately and securely pocketed in a manner which prevents contact with adjacent arrowheads and inadvertent triggering (release) of the folded broadheads (in which regard, the limited depth of the tip pockets ensures that the folded blades do not make contact with the wall 42 or any adjacent structure. Of course, while the foregoing description has primarily been given in connection with the more recently introduced mechanical broadhead-equipped arrows, the quiver 10 will nonetheless readily accommodate older-styled broadheads as well, which have fixed blades. In either case, the removal of arrows from the quiver from their securely mounted position is readily accomplished by grasping the arrow shaft somewhere near the bottom arrow holder 18 and lifting it upwardly and away from the quiver stem 14 , whereupon the arrow shaft first leaves arrow holder 18 and then is levered out of the forward or upper arrow holder 16 due to the pivotal engagement of the arrow point with the sides of its tip pocket, a principal functional advantage provided by the structural arrangement described. In this manner, arrow removal is positive and easy, with no risk of impacting the arrowhead of the arrow being removed with those adjacent it, inasmuch as the tip pocket arrangement precludes this while at the same time contributing greatly to the easy and positive removal of mounted arrows from the quiver.
The above description is considered that of the preferred embodiments only. Modifications of these embodiments in accordance with the invention will occur to those skilled in the art and to those who make or use the invention. Therefore, it is to be understood that the embodiments described above are merely for illustrative purposes and not intended to limit the scope of the invention, which is generally set forth in the appended Statements of Invention, and/or corresponding claims, as interpreted according to the principles of patent law, including the doctrine of equivalents. | A new form of bow-mounted arrow quiver, which will safely and satisfactorily carry a plurality of different kinds of broadhead-tipped arrows, particularly, mechanical broadhead arrows, regardless of shaft size (diameter), while maintaining each different broadhead out of contact with the others contained within the broadhead shield. | 8 |
FIELD OF INVENTION
The invention herein relates to a method and apparatus of a game of skill and coordination, wherein play patterns including revolving motion of various ones and groups of game pieces are imparted to a plurality of game pieces slideably received on a flexible cord.
BACKGROUND OF INVENTION
People have always enjoyed playing games of skill and dexterity. Often what appears to be a simple game apparatus manipulated in a straightforward manner in fact requires a great deal of dexterity and practice to master. There have been several games wherein the game apparatus involves balls mounted on string. Once such game apparatus is disclosed in U.S. Pat. No. 3,605,327 to Jones. The Jones game includes a string having a plurality of balls fixedly secured thereon at spaced-apart fixed positions thereon. A free end of the string can be manipulated to establish a whirling motion of the balls, with the balls in alignment. Mulvy U.S. Pat. No. 1,241,000 discloses a toy comprising a rubber elastic string having a single ball slideably received thereon between two stop members. The ball may be caused to vibrate in vertical or lateral modes by manipulation of the rubber elastic string, wherein the forces stored in and released from the rubber string contribute to the play.
Smith U.S. Pat. No. 1,932,943 discloses a twin ball toy comprising a string having a ball fixed at each end thereof and a handle at a central point between the balls. Smith's handle permits adjustment of string length, particularly as an aide for persons learning the game. French Patent No. 1,109,355 discloses a similar game, with the string having a handle loop formed at the approximate mid-point and there being provided two additional balls, preferably of different size and weight, which are urged against the end balls during play.
The foregoing games make apparent the interest in activities of skilled manipulation and a desire for new and different games and activities of that character.
SUMMARY OF INVENTION
Accordingly, it is a principal object of the invention herein to provide a game using relatively simple game apparatus, but requiring dexterity and skill in play.
It is an additional object of the invention herein to provide a game of the foregoing character which is adapted for variations in play.
It is a further object of the invention herein to provide a method of playing a game with game apparatus of a given character.
Game apparatus according to the invention herein comprises a thin elongated flexible cord and a plurality of game pieces, conveniently in the form of disks. Each of the game pieces has an opening therein and the game pieces are threaded onto and loosely slideably accommodated on the flexible cord. The game pieces are restrained from sliding off a first free end of the flexible cord, conveniently by a stop member which is larger than the opening in the game piece adjacent thereto or by fixing the end game piece to the cord. A sufficient amount of flexible cord is provided to play the game in the ways described below, as well as in other manners both taught herein and provided by the ingenuity of the user of the game apparatus.
The invention herein is also directed toward a method of playing a game utilizing an apparatus as described above by hand grasping the flexible cord with at least one game piece positioned on the depending free end of the cord while holding at least the next adjacent game piece in the same hand, and moving the hand to cause the game piece at the free end of the cord to revolve in a generally circular path. The method further comprises thereafter releasing the next adjacent game piece from the hand, and continuing to move the hand to cause revolution of the game pieces, with at least two of the game pieces at spaced-apart positions along the cord and revolving out of phase.
According to a preferred embodiment of the apparatus and methods according to the invention herein, four game pieces are provided, and they are placed in revolving motions in either pairs of two or in other various deployments.
Other and more specific objects and features of the invention herein will in part appear from the following description of the preferred embodiment and claims, taken together with the drawings.
DRAWINGS
FIG. 1 is a perspective view of a game apparatus according to the invention herein;
FIG. 2 is an elevation view of a user holding the game apparatus preparatory to executing a basic play pattern;
FIG. 3 is an elevation view of the game apparatus being manipulated by the user in a basic play pattern derived from the starting position of FIG. 2;
FIG. 4 is an elevation view of the game apparatus being manipulated by the user in a variation of the play pattern illustrated in FIG. 3;
FIG. 5 is an elevation view of the game apparatus being manipulated by a user in yet another variation of the basic pattern illustrated in FIG. 3;
FIG. 6 is an elevation view of the game apparatus being manipulated by a user in an additional play pattern;
FIG. 7 is an elevation view of the game apparatus being manipulated by a user in a further play pattern;
FIG. 8 is an elevation view of the game apparatus being manipulated by a user in another, unstable play pattern; and
FIG. 9 is an elevation view of the game apparatus in altered configuration being manipulated by a user in a play pattern.
The same reference numerals refer to the same elements throughout the various figures.
DESCRIPTION OF PREFERRED EMBODIMENT
With reference to FIG. 1, a game apparatus 10 according to the invention herein comprises an elongated flexible cord 12 having a stop member 14 secured to one end thereof, and four game pieces 20, 22, 24 and 26 slideably received on the flexible cord. The game pieces 20 are in the form of four identical disks approximately five (5) centimeters in diameter and two (2) centimeters thick and have a central opening, e.g. opening 28 in disk 26, which is approximately one half (1/2) centimeter in diameter. The diameter of the central openings is selected such that the disks slide freely on the flexible cord 12. The disks 20, 22, 24 and 26 may be fabricated of a variety of suitable materials, including wood and plastic. It will be appreciated that the disks can vary in diameter from approximately one (1) centimeter to fifteen (15) centimeters, that the disk thickness can vary from very thin to approximately eight (8) centimeters, and that the shape of the game pieces can also vary from the disk configuration of the preferred embodiment.
The flexible cord 12 is preferably approximately two (2) meters in length and the stop member 14 secured at the end of the cord may be a ring or bead or tab which can be easily secured by a knot about which the cord 20 may be tied. This permits the cord to be replaced easily in the event of wear. For many ways of playing the game, the end game piece 20 may be secured to the cord and thereby function as the stop member for the remaining game pieces.
The remaining Figures illustrate methods of utilizing the game apparatus 10 of FIG. 1. Although the methods illustrated are not exhaustive of all possible play configurations of the game apparatus, they are representative and illustrative of basic methods of utilizing the game apparatus.
With reference to FIGS. 2 and 3, the initiation of a basic play pattern and the established basic play pattern are respectively illustrated. In FIG. 2, the upper two disks 24 and 26 are aligned and grasped in user's hand 1, and conveniently with the index and middle finger flanking the central opening of disk 24. The flexible cord 12 is gripped at 30 above the disk 26 by the ring and/or little finger, and a portion of the flexible cord 12 extends downwardly and supports the disks 20 and 22 a distance below the hand 1. With the dimensions of the preferred embodiment game apparatus 10 set forth above, the distance between disk 24 and end stop 14 may be approximately two feet for satisfactory results. While continuing to hold the flexible cord 12, the upper two disks 24 and 26, disk 24 being the next adjacent disk to disk 22, are released from the hand while simultaneously imparting a horizontal circular motion to the said disks 24 and 26. At this point, it may prove convenient to the user to grip cord 12 between the index finger and the thumb of hand 1, and in any event, a gentle horizontal circular motion is continuously applied to the gripped point of the flexible cord, as indicated at 31, resulting in the play pattern shown in FIG. 3. More specifically, in the transition from the start position of FIG. 2 to the play pattern of FIG. 3, the upper blocks 24 and 26 slide partway down the flexible cord 12 and revolve in a generally horizontally, generally circular path indicated by the dotted lines 32. The lower disks 22 and 24 are also established in a generally horizontal, generally circular revolving path 34, with the disks 20 and 22 being approximately 180 degrees out of phase with the disks 24 and 26, i.e., the center of mass of all of the disks is along an axis 36 at the center of the paths of revolution.
The pattern of play illustrated in FIG. 3 may be maintained by continuing the small horizontal circular motion of the hand, and more particularly the motion is most easily generated by the finger and the thumb grasping the upper end of the flexible cord 12 at 38. The speed of rotation may be varied, causing the circular paths to become closer together, until the blocks appear to the eye to be revolving in a common plane, or decreased, until the centrifugal force is insufficient to maintain disks 24, 26 at the position shown and disks 24, 26 slide down to join disks 20, 22.
An alternative way of establishing the basic play pattern of FIG. 3 is to grasp the cord 12 with all four disks and approximately eight inches of string depending from the user's hand. Moving the finger and thumb grasping the cord in a gentle, small horizontal circular motion causes the upper two disks 24, 26 to separate from the lower two disks 20, 22. As the separation occurs, the user permits some of the excess cord to slip slowly between the fingers and thumb grasping the cord, thereby providing an additional length of depending cord and providing additional room for the disks to spin, until the pattern shown in FIG. 3 is established. It takes slightly more vigorous motion to cause separation of the disks than is necessary to keep them in motion, but in any event, the force is gentle and jerky motions of the block are an indication of excess or unsmooth application of force.
With reference to FIG. 4, a first alternate play pattern of the game apparatus 10 is illustrated, with the disks 20, 22 and 24, 26 revolving in vertically oriented circular paths. This play pattern can be achieved by first establishing the basic play pattern illustrated in FIG. 3 and by adding a slight vertical component to the motion-inducing hand movement, causing the disks to be drawn toward a vertical orientation and increasing that vertical component until the vertical orientation of the paths of rotation is achieved. For sustaining the vertical pattern shown in FIG. 4 it is preferable to cause disks 20, 22 to pass on alternate sides of the flexible cord extending from the hand 1 to the upper disks 24, 26 on each revolution of the disks.
With reference to FIG. 5, the method of using the game apparatus 10 comprises a further variation achieved as a progression from the play pattern of FIG. 4. In FIG. 5, a portion 38 of the excess length of cord 12 (cord which merely trailed away from the grasp point in previous play patterns) is stretched taut between the user's hand 1 being using to grasp the cord and impart motion to the disks and the user's second hand 2. As the disks 20, 22 approach the upper portion of a vertical revolution per the play pattern of FIG. 4, hand 1 is manipulated to cease imparting the vertical revolving motion to the disks and instead flip the lower two disks 20, 22 over the taut portion 38 of the cord 12. In FIG. 5, the disks are shown in solid as they approach the taut portion 38 of cord 12 and in dotted as the lower disks 20, 22 go over it. The disks 24, 26 will follow the lower disks 20, 22 over the taut portion 38 of the cord, and the disks may then be allowed to settle into the play pattern of FIG. 3. Alternatively, the vertical motion may be allowed to settle down to horizontal in the opposite direction to that of FIG. 3.
With reference to FIG. 6, there is illustrated another play pattern utilizing game apparatus 10 according to the method of the invention herein. In FIG. 6, the disks are separated into uneven groups, with disks 20, 22 and 24 adjacent the stop member 14. The remaining disk 26 is revolved at a spaced-apart location along cord 12, which is accomplished by starting the play pattern in a manner similar to that shown in FIG. 2 and discussed above except that only disk 26, being next adjacent disk 24, is held and given its initial circular motion by the user's hand. The user maintains the play pattern shown in FIG. 6 by moving his hand, or at least the finger and thumb thereof grasping the cord 12, in a small circular path as indicated at 40 which causes the lower combined disks 20, 22 and 24 to also move in a generally horizontal circular path shown by dotted line 42 and the disk 26 to also move in a generally horizontal circular path shown by dotted lines 44, spaced upwardly therefrom. It will be seen and appreciated that the circular paths are of differing size such that the center of mass of the four disks remains approximately on an axis of revolution 46. The play pattern of FIG. 6 may be further varied by regrouping the disks, with the disk 20 adjacent the stop member 14 and the disks 22, 24 and 26 together established in a spaced-apart generally horizontal and generally circular path of revolution.
Another variation in play pattern and method of play is illustrated in FIG. 7, with disks 20, 22 together positioned adjacent stop member 14 and established in a generally horizontal, circular path or orbit of revolution and disks 24, 26 also established in generally circular paths of revolution, spaced-apart and in phase with each other but out of phase with disks 20 and 22. The pattern of FIG. 7 is established in a manner similar to that illustrated in and described with respect to FIG. 2 above, except that only the next adjacent disk 24 is released initially and the disk 26 is released thereafter. The pattern illustrated in FIG. 7 is unstable in that the disks 24 and 26 eventually come together, and the challenge to the player is to first establish the pattern and to second maintain it for as long as possible.
The foregoing methods of play and resultant play patterns are generally stable, i.e., they may be continued more or less indefinitely with correct input motion of the user, and even in the case of the play pattern illustrated in FIG. 7, an altered play pattern continues after the blocks 24 and 26 move together. There are other methods of play and resultant play patterns which are unstable and break down into uncontrollable motion of the game pieces, but are nevertheless entertaining both in terms of the skill necessary to begin them and the aesthetics of the play patterns themselves, albeit short lived. An example of such a play pattern is illustrated in FIG. 8, wherein the disk 20 and the disks 22, 24 are established in spaced-apart, out of phase generally circular paths of revolution 50 and 52 respectively, similarly to the patterns discussed in FIGS. 3 and 6 above. However, the fourth disk 26 is established in a counter-rotating generally circular path of revolution 54 by a reversal of the circular hand motion and simultaneous release of the disk 26. Because there is no further input motion to maintain the patterns by disk 20 and disks 22, 24, the play pattern shown in FIG. 8 is achieved for only a short duration of time. Other such unstable patterns of play are available to the user through his imagination and experience in utilizing the game apparatus 10.
FIG. 9 illustrates that the game apparatus itself may be reconfigured to achieve alternate patterns of play. The disks 20, 22 are positioned adjacent the stop member 14, and the flexible cord 12 extends upwardly therefrom. A loop 12a of the cord is formed at a point spaced-apart from the stop member 14 and is secured to the cord at the knot 15, the loop 12a passing through the central openings of disks 24 and 26. Disks 20 and 22 are deployed on portion 12b of cord 12, extending from the knot 15 to the stop member 14. Portions 12a and 12b are of slightly different length, so that the knot is offset with respect to the center of mass of the disks. A gentle circular motion of the user's hand on the free end of the flexible cord 12 establishes the disks in a generally circular orbit, as illustrated.
Accordingly, there has been described a game which requires skill to play and which occupies and entertains people. The game apparatus disclosed is capable of use in a variety of play patterns, and the skill, imagination and ingenuity of the users will undoubtedly supply more variations. It will be appreciated that various changes may be made in the preferred embodiment disclosed above, including provision of a different number of disks or other shaped game pieces on the flexible cord, with accompanying variations in patterns of the game pieces. Another beneficial but temporary modification is to tie the blocks in spaced-apart locations along the flexible cord according to the desired pattern for training purposes, and to spin the game pieces in the desired pattern while they are held in position on the cord prior to attempting the same patterns with the game pieces freely slideable on the cord. Therefore, the scope of the invention is limited only by the following claims. | A game of manual dexterity and skill utilizes a game apparatus comprising a thin elongated flexible cord and a plurality of disks each having a central opening therein loosely accommodated on the flexible cord, with a stop member preventing the disk from sliding off. A variety of play patterns may be established by manipulating the game apparatus to separate the disks and revolve the disks in generally circular paths. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to devices and processes for metal organic chemical vapor deposition. More particularly, this invention pertains to a apparatus and methods for creating a generally flat temperature zone on a substrate for growing semiconductors.
2. Description of the Prior Art
In the past, chemical vapor deposition on substrates which achieved satisfactory yields has generally required devices of high energy consumption. Typically, a wafer of gallium arsenide is heated prior to and during vapor deposition through a system utilizing electromagnetic radiation or radio frequency induction heating. The costs of this equipment for generating heating for wafer deposition is high and the costs of operating is expensive as a result of high energy consumption and the inability to efficiently utilize and direct energy.
A system has been tried using a carbon block used as an electrical resistance heating element beneath a quartz support. One difficulty encountered with carbon block resistance heating is that there is a lack of uniformity in heating of the water, resulting in lower quality yields.
A low pressure MOCVD system has used a reactor having a hexagonal SiC coated graphite sample holder which is heated by quartz halogen lamps placed at its center. The lamps are enclosed in a double quartz walled jacket which isolates them from the sample holder. The walls of the substrate holder are slightly tilted backward toward the center of the holder and each face has recesses for 3 inch square wafers. A total of 30 to 50 wafers can be processed in a single run. Power to the lamps is controlled by a computer which monitors and controls power to maintain it at a constant level. An operator can observe temperature through a small "peephole" in the reactor chamber but there is no feedback temperature control. Temperature variations in this system are large and uncontrollable. The major disadvantage of this system is its high initial and process costs.
SUMMARY OF THE INVENTION
A chemical vapor deposition heater in accordance with this invention generally comprises an envelope which supports a heater core. The core establishes an annular heated region at which location heat is substantially concentrated. Means are provided for heating the core to raise the core temperature to develop heat at the annular region. A buffer or plate is disposed in thermal contact with and generally above the annular region to receive and buffer intense heat over a circular surface generally above and inward from the annular region, and thereby provide a uniformly heated surface over a substantially flat temperature range. This allows the placement of chemical vapor deposition substrates on the buffer which will be heated a substantial, yet highly uniform temperature across its surface.
In particular examples, the core has a resistance winding and defines a hollow chamber. The core supports a buffer in a pill box configuration.
Additional features in accordance with this invention includes an inert film heat shield on the interior of the envelope. The core is made of boron nitride and has a surrounding insulator or zirconia cupping the core. The buffer is against a quartz surface to assure uniform conduction to a platten for supporting a substate. The envelopes are of quartz. Multiple envelopes may be disposed in arrays for mass production of growing semiconductors. The heaters may be individually rotatable using mercury contacts for achieving even greater heating uniformity. A horizontal form of the heater has an elongated envelope and a core substantially upright adjacent one end of the envelope.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the invention may be had in viewing the drawings taken in connection with the following description in which:
FIG. 1 is a diagrammatic elevational view of epitaxial heater apparatus in accordance with this invention;
FIG. 2 is a perspective view of a portion of the invention depicted in FIG. 1; with portions exposed and portions removed;
FIG. 3 is a detailed elevational view of a portion of the invention depicted in FIG. 1;
FIG. 4 is an exploded elevational view of a core of the invention depicted in FIG. 3;
FIG. 5 is a plan view of a portion of the invention depicted in FIG. 1 taken along lines 5--5 of FIG. 4;
FIG. 6 is a plan view of an epitaxial heater array in accordance with this invention;
FIG. 7 is an elevational view of an epitaxial heater array taken along lines 7--7 of FIG. 6.
FIG. 8 is a diagrammatic view of a horizontal epitaxial heater apparatus in accordance with this invention.
FIG. 9 is a horizontal epitaxial heater apparatus disposed in a reaction chamber, in accordance with this invention;
FIG. 10 is a cross-sectional view with portions exposed and removed of an electrical feedthru of the quartz envelope heater depicted in FIG. 1, in accordance with this invention;
FIG. 11 is a bottom view of the feedthru depicted in FIG. 10;
FIG. 12 is an exploded detailed view of quartz envelope heater of FIG. 10;
FIG. 13 is a bottom view of the zirconia insulation of the horizontal heater depicted in FIG. 8;
FIG. 14 is a cross-sectional elevational view of the zirconia heater depicted in FIG. 13;
FIG. 15 is a cross-sectional elevational view of the boron nitride core of FIG. 8; and
FIG. 16 is a cross-sectional plan view of the boron nitride core depicted in FIG. 15.
DETAILED DESCRIPTION
With particular reference to FIGS. 1, 2 and 3, a system for heating gallium arsenide substrates in accordance with this invention generally comprises a quartz envelope heater 10 which comprises a quartz envelope 12 and a resistance heater 14 disposed within the quartz envelope 12. The envelope 12 may be disposed in a separate environment or in combination with other envelopes. The resistance heater 14 is pinned up against an upper surface 16 of the quartz envelope 12, adjacent a quartz wafer support 18 where a substrate 20 is heated. At the bottom of the resistance heater 14 is a narrow elongated quartz support 22. Electrical power leads 24 and thermocouple leads 26 exit through the quartz support 22 at a heater base 28. The quartz envelope 12 shields both the resistance heater 14 and leads 24, 26, preventing contamination with the environment surrounding the quartz wafer support 18. Thus, process gases, when present, only come in contact with the exterior of the quartz envelope 12.
The resistance heater 14, best viewed in FIG. 2, comprises a boron nitride core 30 comprising a boron nitride top 29 and a boron nitride base 31 which is wrapped with a 20 mil. resistance winding 32 of platinum/20% Rhodium. Boron nitride is used for the core 30 because it has high thermal conductivity, good thermal stability, good electrical insulation and good machinability. Platinum/rhodium wire is used for resistance windings 32 because of its ability to withstand high temperatures. Alternatively for cost savings, molybdenum wire may be used for the resistance windings where the envelope 12 is evacuated. The core 30 has threaded grooves 34 achieved by lathing, to make it easier to wind the resistance windings uniformly and snugly. That construction permits a predictable temperature profile on the top surface of the heater 10 and improves the thermal contact between the resistance windings 32 and the core 30. After the resistance winding 32 is wrapped around the core heater 30, alumina cement 36 is applied which provides electrical insulation and increases thermal conduction from the resistance winding 32 to the boron nitride base 31. The cement 36 conducts heat, yet insulates electrically.
The heater 14 is supported by a cup shaped zirconia ceramic insulator 40 having a cylindrical outer surface 44 and a narrower cylindrical inner surface 46. A platinum foil reflector heat shield 48 surrounds the insulator and the boron nitride core 30. Rather than platinum foil, an inert reflective coating on the inside surface of the quartz envelope 12 may be used. The boron nitride core 30 has a pill box configuration defining a hollow cylindrical chamber 50 and an upper annular surface 52 at the top of the base 31 above and encircling the chamber 50. The boron nitride top 29 has an upper portion 56 having a diameter of that of the base 31 and a resistance winding 32 and a lower portion 58 coaxial with the upper portion 56 and a diameter mating with and insertable in the hollow cylindrical chamber 50 of the base 31. The lower portion 58 defines a ring surface 59 which bounds a lower annular surface 61 of the upper portion 56. The upper annular surface 52 of the base 31 energizes the lower annular surface 61 of the upper portion 56. The top 29 establishes a flat temperature zone 60 on its surface and on the quartz wafer support 18 as a result of the heated annular surface 52 at the top of the core 30. Only the annular surface 52 of the base 31 touches the boron nitride top 29.
Thus, heat is conducted efficiently from the base 31 to the perimeter of the boron nitride top 29 where heat then spreads radially inward in a manner so as to produce a uniform temperature across the surface of the top 29.
The balancing of efficient and inefficient heat conduction paths from the heater 14 to the boron nitride top 29 (plus convective heating in examples where the envelope 12 is not evacuated) yields the flat temperature zone on most of the top surface 62 of the quartz envelope 12. The base 31 of the resistance heater 14 contains a thermocouple 64 to measure the heater's temperature. The quartz envelope 12 shields the heater's functional parts from process gases and maintains the purity of the process. Power leads 24 as well as the thermocouple leads 26 exit the heater 14 through the narrow elongated quartz support 22, and argon, (where molybdenum wire is used) constantly purges the heater through an opening in the quartz envelope heater's base 28.
In an enclosed environment, the heater 10 is attached to the base of the reaction chamber 70 with a double O-ring seal 72. Though the heater is stationary, it may be configured for rotation. Multiple heaters 10 may be individually rotated and connected in parallel or separately to confined or individual power sources.
In one example, the operation of the envelope heater 10 was calibrated as follows. The top surface 60 temperature was measured simultaneously with that of the base of the core heater 14. The heater's top surface temperature could then be set by adjusting the core temperature. The calibration was performed under conditions similar to those for growing epitaxial material. The heater was attached with a double O-ring seal 72 to a base plate 74 on which the reaction chamber 70 is mounted. A silicon standard wafer 76 was then mounted on the top surface 62 of the quartz envelope 12. The reaction chamber 70 was then evacuated and filled with hydrogen gas flowing at the set rate of 5 standard liters per minute (SLPM). The core 30 was powered with a Rubicon power controller, which in turn was controlled by a Barber Coleman 560 three-mode proportional controller.
The temperature of the heater's top surface 62 was measured with an Ircon infrared pyrometer, which is sensitive to radiation between 2.0 and 2.6 micrometers. The pyrometer measured the radiation from the highly polished silicon wafer placed on the heater's top surface 62. Silicon has a known emittance of 0.7 and serves here as a reference for optically measuring the surface temperature of actual GaAs wafers. The optical properties of the reaction chamber walls encasing the heater 10 had to be considered in the measurement. The walls transmit only a fraction of the radiation emitted from the wafer 76. Therefore, the emitance was set on the pyrometer at 0.63, corresponding to a wall transmittance of 90 percent. A Pt/Pt-13% Rh thermocouple mounted in a recess at the core heater's base measured core temperature in degrees Celsius, using a digital theromouple readout.
With reference to FIGS. 6 and 7, an array of quartz envelope heaters 10 in accordance with this invention are disposed in a circular array. A plurality of diffusers 80 or tubes for causing process gases to pass over the heater are disposed above and mate with the individual quartz envelope heaters 10 to cause reactant and dopant gases to be passed across the wafer substrates 76. The particular quartz envelope heater system shown and described can process thirty six 3" (7.6 cm.) diameter wafers at one time, and growth can be done at either low pressure or atmospheric pressure. These features are competitive with the prior art reactors, however, it has temperature control, better wafer to wafer uniformity, and minimizes waste of metal organic compounds and arsine during production runs. This last advantage results from directing the reactant vapor directly to the substrate surfaces. Much of the reactant vapors in the prior art systems, however, just pass through without being consumed to form epitaxial layers, which makes those systems inefficient and expensive to operate.
The array of heaters are disposed in a circular configuration in which 18 heaters each having a 3" diameter are disposed in an outermost circular array 84, spaced apart approximately 5 inches (12.7 cm.) center to center from one another. An adjacent middle circular array 86 of 12 such heaters are disposed on the interior and coaxial with the outer array. An adjacent inner circular array 88 of 6 such heaters are disposed on the interior of the middle circular array. Interference between heaters 10 is not critical as the heat energy of the heaters tends to be highly localized above the boron nitride core 30.
Subdividing a reactor chamber eliminates many problems which plague system using monolithic heaters, including maintaining thermal uniformity. Flow problems are minimized since each sample has its own chamber. Reactants are not be wasted and interfaces between layers would be sharper because reactants would be piped directly to each sample where a diffuser with a minimum volume would be used.
With particular reference to FIG. 12, the construction of the outer quartz envelope 12 includes a 1/8" (0.3 cm) plate 104 which provides the wafer support 18 and a 6" (15 cm.) long by 3" (7.6 cm) quartz tube 102 with a 2 mm. wall. Initially the tube 102 is open at both ends. The flat plate 104 is joined to the quartz tube 102 at one end to completely close it off at that end. The joining of the plate and tube is accomplished by first beveling the perimeter of the plate on its two sides so that its perimeter is thinned, leaving a beveled surface. The plate is held vertically in a lathe by a vacuum chuck and the open tube is held horizontally in the lathe adjacent to the plate. The two pieces are brought together with the edge of the plate pressed over the wall of the tube. Heat is then applied to seal the join. Once joined, a coating of platinum is formed on the inside wall of the tube. The coating extends from the bottom of the tube where the plate is joined to three inches above the plate. The platinum coating is applied as a chloroplatinic acid solution in rose oil. The rose oil acts to give the solution body. Two coatings are applied by brushing the solution on the inside wall of the tube. Following each application of solution the tube end plate is heated to 900 degrees C.
The midsection of the quartz envelope 12 consists of a 3/4" (1.9 cm) tube 108 which is 12" long with a 3 mm. wall attached to a 1" inch length of 3" diameter tubing 106 with a 2 mm. wall by a quartz transition. The transition is accomplished by necking down the diameter of the larger tube to approximately 3/4" and making a join to the smaller tubing 108. They are joined in a lathe by the application of heat. An opening is formed at the base 110 of the 3" tube where it is rounded to form the neck. At 1/2" diameter by 3" long tube 114 is attached to the opening. This tube 114 is for evacuating the envelope 12 at the final stage of construction.
At the base 31 of the heater 14 and the quartz envelope 12 is an electrical feedthru 116. It is a tube which is rounded and closed at its base 118 but open at its top 120. From base 118 to top 120 it is 2" long and has a 16 mm diameter. The top 120 of the feedthru is composed of quartz glass; the quartz glass extends one inch from the top of the feedthru 116. Next, there are seven layers or grades of glass which are layered until the base 118 is reached where there is uranium glass 124. Four covar feed thrus 122 are embedded in the uranium glass 124. They extend one inch into the tube and 1/2 inch outside the closed end of the tube. Two of the feedthrus 122 accept 0.100" heater wire and the other two tubes 122 accept 0.040" thermocouple wire. The pins or feedthrus are situated at the corners of an imaginary square with the larger pins and small pins diagonal to each other, as shown in FIGS. 10 and 11.
The inner quartz support tube or base 28 comprises a 1/2" quartz tube which is joined by a neck to a 2" long by 1" diameter quartz tube. The end of the 1" tube which is open has a flair with a 2" diameter. The flair is such that it nearly forms a flat surface perpendicular to the axis of the two tubes.
Support insulation for the resistance heater 14 is formed from zirconia supporting the core 30. The insulation serves to center the heater 14 in the quartz envelope adjacent the upper surface 16 and acts as a cushion between the quartz support 28 and the core 30. The insulation form is constructed as follows. Flat 1/2" thick boards of zirconia insulation are cut with cooky cutters by pressing them into a flat board to form three 21/2"×1/2" discs. Two of the discs are in turn cut with a 2.16" cooky cutter to form two rings with a 2.16" ID and a 21/2" OD. The two rings are stacked one on top of another and in turn the two rings are stacked on the 21/2" solid disc. High temperature alumina cement is placed between the individual parts before they are stacked and excess cement is removed by pressing the three parts together tightly by hand. The cement joints are then air dried.
The boron nitride core heater 30 comprises two parts, the boron nitride base 31 and the boron nitride top 29. The boron nitride top 29 top fits integrally onto the boron nitride base 31 to form a "pill box" like structure.
The boron nitride base 31 has two opposing cylindrical cavities 50, 130 with a flat 0.375" thick floor 135 separating them. The cylinders have an OD of 2.160". The top cylindrical cavity or chamber 50 is 0.625" deep by 1.850" in diameter while the bottom cavity 130 is 1/4" deep by 1.580" in diameter. The cavities 50, 130 are formed on a lathe with a boring bit. A 0.050" wide by 0.060 deep thread 34 is formed on the OD of the two cavities so that it extends from top to bottom of the OD of the boron nitride base. The pitch of the thread is such that there are 12 threads per inch. One 0.040" aperture 132 is made a 1/16" from the bottom of the boron nitride base and another 0.040" aperture 133 is made in a floor 135 separating the two cylindrical cavities 50, 130. The two apertures 50, 130 oppose each other and are situated on a diameter of the base 31. A notch 134 is filled at the top of the upper cavity 50 about one inch counterclockwise from the floor 135 separating the cavities (looking down at the cavity).
The boron nitride top 29 is a cylindrical disc with a 2.160" OD by 0.312" thick. The boron nitride top disc 29 has a 0.16" of material removed from the OD to a height of 0.125". The material has been removed so that the top can snuggly fit into and cover the deeper cylindrical cavity or chamber 50.
A 0.035" molybdenum wire is fed though the aperture 132 at the bottom of the boron nitride base 31 wrapped in the thread grooves 34, placed in the notch 134 at the top of the boron nitride base 31 and finally fed through the aperture 133 in the boron nitride floor 135. The wire is then threaded through a 4 aperture rod of alumninum which acts as a support to hold the wires and boron nitride base 31 while high temperature alumina cement 36 is applied. The threads and wire in the threads are coated with high temperature alumina cement to hold the wire in place. The cement is air dried.
The 4 aperture rod is removed. A 0.060 aperture is drilled in the wall separating the two chambers at its exact center. A chromel-alumel thermocouple bead 140 is placed just through the aperture and cemented. The cement is air dried.
The two thermocouple 26 and two heater wires 24 are brought together in a bundle. Alumina fish spine beads 142 are placed on all wires 24, 26 above where they come together to form a bundle. The wires 24, 26 are covered from the point of bundling up till they form a part of the boron nitride base 31. The bundled wire can now be fed through a 6" length of 4-aperture alumina rod.
Two 6" lengths of 0.100 precision ground OFHC copper each with a 0.040" inch diameter by 3/8" aperture 137 drilled at one end are attached to the edge of the molybdenum wire 24. The wire is placed into the apertures, the copper rod 139 is crimped and silver solder is placed at the junction of the wire and the top of the copper rod. A 1/8" nextel sleeving is placed over the copper rods and 0.040 nextel sleeving is placed over the two thermocouple leads 26. A 1/4" aperture 148 is formed at the base of the zirconia insulator 40 previously described. The 4 leads from the heater 14 plus the 4 aperture rod are placed through the aperture in the base of the zirconia insulator 40 so as to allow the base 31 to be cupped in that structure. The copper rod is used to reduce overheating of the feedthrus.
The 4 leads from the heater 14 plus the 4 aperture rod are placed through the inner quartz support tube so that the flair 127 is pressed up against the bottom of the zirconia insulator 40.
The inner quartz support tube 22 with zirconia insulator 40 and boron nitride base 31 and top 29 are placed inside the quartz midsection 150.
The thermocouple wire 26 and copper rods are guided through the electrical feedthru 116. The feedthru 116 and midsection 150 are permanently joined. Copper rods and thermocouple wires 26 are attached to feedthrus by applying silver solder.
The quartz top 104 is joined to the midsection so that the boron nitride top 29 contacts the flat quartz plate 104 firmly. The quartz envelope heater 10 is evacuated with a vacuum pump by attaching the pump to the 1/2" vacuum tube at the base of the 3" diameter top.
Power is applied to the heater and is increased while monitoring pressure of the heater and pump. The power is only applied to the molybdenum wires. Once the pressure has stabilized almost all water has been removed from the alumina cement and it is cured.
Finally, power is removed and the side arm vacuum tube is sealed.
With particular reference to FIGS. 8 and 9, a horizontal quartz envelope heater in accordance with this invention may be constructed having a square quartz tube 200 with flour flat faces or sides 202, 204, 206 and 208. The top face 202 is ground to form a 2"×0.020" deep depression which is flat at its bottom. The depression is centered on the top face. Other than the depression, the four faces are flat both on the inside and outside of the square tube. The square tube is initially open at both ends but is then closed off at one end with a hollow bullet shaped end cap 210 composed of quartz. The transition 212 from the bullet shaped end-cap to the square tubing is smooth. The square tubing is approximately 3"×3" long. The bullet shaped end cap is approximately 1" long. The side walls and base but not the top are internally covered with chloroplatinic acid solution in rose oil and baked for platinum coating.
The transition to a midsection 216 is at an angle to the square tube 200. projection of the top surface and open end of the square tub shows that the two surfaces are originally 90 degrees with respect to each other where the intercept of the two surfaces forms the origin. If the open end is at 0 degrees then by rotating an imaginary line about the origin by 15 degrees clockwise and cut the square tubing at this angle with a silicon carbide blade.
The midsection 216 of the quartz envelope is constructed of 3/4" diameter tube with a 3 mm which is 12" long attached to a 1" long piece of 3" by 3" square tubing by a quartz transition. The midsection is joined to the square tube 200 at an angle defining an interception plane. The top face 202 defines a plane and the intersection of the top face plane and the interception plane is at an angle of 75 degrees. The effect of this is to permit the placement of the heater within a reactor 217 so that the heater can support a wafer substrate at an angle to the horizontal, allowing process gases to better be passed more directly across the wafer substrate, as best viewed in FIG. 9.
The transition 216 is fabricated by necking down and rounding a square tube, which is initially longer than 1", until a round end of 3/4" diameter is formed. This is fabricated by holding the square piece in the lathe, rotating it, applying intense heat and shaping it with a carbon flatstock. Once the square quartz tube has been necked down and rounded it is mated to the 3/4" diameter by 12" tube. An opening is formed at the base of the 3"×3" tube where it is rounded to form the neck. A 1/2" diameter by 3" long evacuation tube is attached to this opening. This tube is used for evacuating the heater envelope at the final stage of heater construction. The base 31 uses electrical feedthrus as with the vertical heater. No inner quartz tube, such as the quartz support 22 in the prior example, is necessary.
The shape of the zirconia insulator 40 is the same as for the vertical heater 10. However, a 1/4" diameter by 1/8" aperture 224 with a flat bottom 226 is drilled at the center of the base of the zirconia structure, the underside of the solid disc, as shown in FIGS. 13 and 14.
With particular reference to FIGS. 3, 15 and 16, the boron nitride core 30 is the same as for the vertical heater 10, except for the number of apertures. Five 0.040 apertures 228 are made 1/16" from the bottom of the boron nitride base 31 a 1/4" apart, and another 0.040" aperture is made in the floor separating the two cylindrical cavities 50, 130. A 0.040" notch 230 is filled at the top of the larger cylindrical cavity 50 about an inch counter clockwise of the aperture in the wall separating the two cavities (looking down at the larger cavity).
A 0.035" molybdenum wire is fed into the second aperture from the right in the cylindrical cavity wall of the smaller cavity of the boron nitride base 31 (side view of the boron nitride base and apertures) so that the wire 232 enters the smaller cylindrical cavity, and is looped through the first aperture on the right, in the floor 135 of the boron nitride base 31. The wire is then wrapped into the thread grooves 34, placed in the notch 134 at the top of the boron nitride base 31 and fed through the aperture in the boron nitride floor 135 that separates the two cavities. Fish spine beads are placed on the wire in a quantity to cover any bare wire extending from the aperture in the floor to the third aperture in the wall of the small cylindrical chamber. The wire is then guided through this third aperture. As in the vertical heater 10, high temperature alumina cement is used to hold the wires to the base 31 of the core 30 and achieve temperature conduction.
A 0.060" aperture is drilled through the floor separating the two cylindrical cavities at its exact center. A chromelalumel thermocouple bead is placed just through the aperture and cemented in place. The cement is air dried. The two thermocouple leads 26 are placed through the two remaining apertures in the wall of the small cylindrical cavity of the boron nitride base but first they are covered with fish spine beads so that the wire is covered between the aperture at the center of the floor of the boron nitride base and the wall of the cylindrical cavity. Enough fish spine beads are placed on the four wires to cover 4". The wire covered is external to the boron nitride base 31.
A 1/4" aperture is drilled through the side of the zirconia insulator 40 about 9/16 from its base. The thermocouple leads 26 and molybdenum wire are bundled together and fed along with the four inches of fish spine beads through the aperture in the zirconia insulator 40 so as to allow the boron nitride base 31 to be cupped in the insulator 40.
The four wires are fed into and through a 6" long 4 aperture alumina rod. Copper rods 139 and molybdenum wire 24 are joined. Nextel sleeving is placed over uninsulated parts.
The boron nitride base 31 and zirconia insulator 40 are placed into the square quartz top so that they are centered with respect to the depression ground into the top surface. The top of the heater 12 is just below the depression. The square tube 299 and heater 14 are turned together so the bottom faces up. Heat is applied with a torch to the glass above the aperture in the bottom of the zirconia insulator 40. The quartz glass is softened and then pushed into the aperture in the insulation. This pins the heater assembly against the top quartz surface. Much of the remaining structure is similar to that of the horizontal heater.
Heat is applied to the dimple which pins the package in place, made at the base of the quartz top. The vacuum will further pull the quartz into the aperture in the base of the zirconium insulator 40 and firmly pin the boron nitride top 29 against the top surface 16.
Thus, a system for growing epitaxial layers has been described which utilizes envelope heaters to mass produce semiconductor epitaxial wafers by efficiently bringing reactants directly to the surface of the substrates. Uniformity is facilitated by temperature feedback to control banks of heaters.
While this disclosure describes the use of the quartz envelope heater system to produce MOCVD epilayers of GaAs and Ga 1-x Al x As, it is possible for this system to be used to produce other materials by MOCVD or other CVO techniques.
The quartz envelope may be replaced with a mullite envelope, or alumina envelope and other materials which are inert to the reactive gases. A molybdenum envelope may also be used, which is embedded in quartz. This could provide more thermal uniformity, molybdenum being a metal, yet it does not dope semiconductors, while quartz can. It is also possible to coat the quartz with alumina and other materials by plasma spraying. A platten of iridium or other nonreacting metal or discs of silicon, sapphire, and the like on the top surface of the heater may be used to flatten the temperature profile more and to protect the heater's surface from reactants. The heater's surface is then always clean and only the platen or nonmetalic discs need to be cleaned.
The expense of the heater can be reduced significantly by replacing the Pt-20% Rh wire winding with tungsten or molybdenum wire and replacing the platinum heat reflector shield with gold reflector or platinum coating that can be formed by the application of a colloidial gold suspension to the envelope, which is then baked.
While the invention has been described with reference to specific forms thereof, it will be understood that changes and modifications may be made within the spirit and scope of this invention. | Chemical vapor deposition apparatus has a quartz envelope supporting a resistance heater. A boron nitride pill box configured core supports resistance heater windings. The core has a base having a cylindrical upper portion defining a hollow chamber and an upper annular ring. A circular top includes an upper circular portion and lower circular portion mating with the base. The annular ring surface is in thermal contact with the upper circular portion to transfer heat from the annular ring to the circular top. A zirconia insulator cups the core, providing heat insulation, in conjunction with a heat shield coating in the quartz envelope interior. Arrays of quartz envelope heaters provide for mass production of semiconductors. A horizontal configuration includes a laminar flow head and disposed at an angle to the horizontal.
In use, a current applied to the windings develops high temperatures for chemical vapor deposition growing of semiconductors on substrates disposed above the envelope with minimal energy utilization. When heated, the heat is transmitted significantly upward along the annular surface of the core, then to the top of the core above the hollow chamber, where the heat is transmitted inwardly from adjacent the annular surface, achieving a generally flat temperature across the surface of the core's top and then maintains that uniform temperature, when the heat is transmitted to a substrate. | 2 |
This is a division of application Ser. No. 790,309, filed Apr. 25, 1977 and now U.S. Pat. No. 4,088,374.
BACKGROUND OF THE INVENTION
Modern highway tractor-trailer rigs are now equipped with air-activated brake systems which incorporate certain structural features required by the government and the trade. One important requirement imposed by regulation FMVSS-121 is that the parking brakes have to be set on the tractor and the trailer by a single control, i.e., a parking valve (hereinafter known as "PV") when parking the rig. Another important requirement is a control, now embodied in the commonly used tractor protection control valve (hereinafter known as "TPCV") which plugs the tractor system from leakage through the trailer connections during "bob-tail" tractor operation, or when rupture of a tractor-to-trailer air line occurs. In order to maintain operator use of brake controls as simple and foolproof as possible, it is desirable, if not essential, that a PV (parking valve) set the brakes of a "bob-tailed" tractor as well as the full rig in spite of some circuitry complications arising out of the inclusion of a tractor protection control valve in the system.
During the years 1975 and 1976, it was recognized that air brake systems conforming to regulation FMVSS-121 having only a TPCV and a PV, permitted a rig to roll freely if parked on an incline if an attempt was made to pressurize the trailer system. It was found during pressuring up that all brakes of the rig were released at an intermediate pressure and, unless the operator was in the seat ready to use pedal control, the rig was free to roll. At this stage of development, a trailer fill valve (hereinafter known as "TFV") was designed and incorporated into a system already containing the TPCV and the PV so that the trailer air system could be filled while the tractor brakes were securely set during the pressuring up operation. The TFV (trailer fill valve) currently used takes the prior art form shown in FIG. 1. Hence, a truck operator now has mounted within easy reach, three valves consisting of a TPCV, a PV, and a TFV. The valves present to the operator three push/pull handles. When the system comprises a TPCV as shown in FIGS. 2 and 3, a PV as shown in FIGS. 4 and 5, and a prior art TFV as shown in FIG. 1, road operation requires that the handle of the TPCV and the PV be pushed down while the TFV handle be pulled out.
With a view to making the brake system as foolproof as possible, it is an essential object of the invention to provide an air brake system for tractor-trailer rigs which includes the three above indicated valves mounted in juxtaposition, such as in a module, on which the handles of all valves may be in similar positions during normal operation of the rig. For example, valves with push/pull control motion with fully pushed-in positions for road operation are preferred.
SUMMARY OF THE INVENTION
In brief, the invention resides in a three-valve control assembly for a tractor-trailer air brake system comprising a TPCV (tractor protection control valve), a PV (parking valve), and a TFV (trailer fill valve) in which all valves have push/pull manual controls and such controls are pushed inward of the respective valve bodies to "bottom" positions during normal operation of the tractor-trailer rig. While the TPCV and the PV of this assembly are conventional, the TFV is constructed to a design heretofore unknown which enables its control element to be pushed inward of its body for operation in which a trailer brake release line and/or trailer air reservoir are constantly connected with another air pressure source on the tractor. This condition is necessarily maintained in the normal operation of the rig. Within the brake system, the TFV has one outlet port connected with the TPCV as the sole source of signal pressure for the relay section of the TPCV. The TFV has two inlet ports for alternatively furnishing pressure to the TFV outlet port depending on the position of the push/pull assembly thereof. One inlet port is connected with the PV and the other inlet port is connected with the tractor air pressure source. The push/pull assembly of the TFV is constructed so that pressure from the PV entering the respective connected inlet port of the TFV will automatically force the push/pull assembly inward because of a difference in piston cross sections, to a pushed-in position wherein the interior of the TFV is arranged to pass air from the main tractor pressure source by way of the PV to the relay section of the TPCV which then releases air to the trailer reservoir section providing the push/pull assembly of the TPCV is in its pushed-in position.
As departures from past TFV construction, the TFV of the invention is constructed solely with laterally oriented ports, an articulated push/pull assembly, a plural-piece body to reduce manufacturing costs through the elimination of close tolerances of coaxial alignment of various parts of the TFV, an automatic pull-in feature and a non-rotating handle.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a view in cross section taken along the longitudinal axis of a prior art trailer fill valve;
FIGS. 2 and 3 are plunger-retracted and plunger-depressed views in cross section of a tractor-protection control valve taken along its longitudinal axis.
FIGS. 4 and 5 are plunger-retracted and plunger-depressed views in cross section of a parking valve used in conjunction with the valve of FIGS. 2 and 3 taken along its longitudinal axis.
FIGS. 6 and 7 are plunger-retracted and plunger-depressed views in cross section of a trailer fill valve used in conjunction with the two valves of FIGS. 2 to 5 taken along a longitudinal axis.
FIG. 8 is an elevation view illustrating a control module which incorporates three valves substantially similar in construction to the valves of FIGS. 2 to 7.
FIG. 9 is a view in cross section taken along line IX-IX of FIG. 7.
FIGS. 10 to 13 are diagrammatic views of a tractor-trailer brake system incorporating the valves of FIGS. 2 to 7 showing various conditions of the system, particularly the settings of the valves, under various conditions.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a prior art valve exemplary of trailer fill valves now in use in trailer brake systems which include a tractor protection control valve, a parking valve and a trailer fill valve arranged to function somewhat as shown by the arrangement illustrated in FIGS. 10 to 13. In present systems, such valves are typically of manual push/pull type with the operating knobs projecting laterally or upwardly along parallel push/pull axes with the valves in close proximity. A source of confusion according to present designs, is that the knob of the trailer fill valve exemplified by FIG. 1 must be in a pulled-out position while the knobs of the other two valves are in a pushed-in position for highway operation. This is even more confusing at nighttime. Ports A', B' and C' correspond in function to ports A, B and C, respectively, of the improved trailer fill valve 5 of FIGS. 6 and 7. The valve of FIG. 1 is shown in the pulled-out position wherein ports C' and B' are connected to deliver fluid in the same manner as is accomplished by the TFV of FIG. 7 in its plunger-depressed condition preparing the system for road operation of the rig as illustrated in FIG. 10.
The TPCV and PV of FIGS. 2 to 5 are of known design but are illustrated and described herein for an understanding of the air brake system illustrated in FIGS. 10 to 13. FIGS. 2 and 3 illustrate the TFCV as having manual plunger valve means, such as the plunger 8. In FIG. 2 the plunger is in retracted position wherein a resilient poppet 9 of the plunger engages a seat 10 to stop flow through the valve from an inlet port 11. In plunger-retracted condition, any pressure in a line connected with the outlet port 12 will have escaped through an exhaust port 14 by way of passageway 15 extending longitudinally and then laterally through the piston 16. Piston 16 is an element of the TFCV and is forced inwardly of the valve housing by fluid under pressure entering the housing 17 through a relay signal port 18 to flow past bosses 19 to apply pressure to surface 21 of the piston 16. When relay signal pressure is applied to piston 16, the piston moves against a return spring 23 to engage and unseat relay valve element 24 as shown in FIG. 3. If the plunger is positioned inwardly of the housing 17 as shown in FIG. 3 to cause poppet 9 to engage seat 25, fluid then flows from supply port 11 through the valve housing by way of passageway 27 and past the unseated element 24 to the outlet port 12.
The PV (parking valve) of FIGS. 4 and 5 has a housing 31 and plunger 32 terminating inwardly of the housing in a resilient poppet element 33. The PV has a first port 35 normally connected with the main air supply of the system of FIGS. 10 to 13 and a second port 36 connected with the rear axle brakes of the tractor. The other of the three ports of the valve is an exhaust port 37 which is placed in communication with the second port 36 and the rear axle brakes of the tractor when the plunger 32 is in its plunger-retracted condition, as shown in FIG. 4 in which the poppet element 33 engages seat 38 so as to block flow of air from the supply port 35. Ports 36 and 37 are thus connected for exhausting air from the tractor rear brakes to the atmosphere through port 37. When the PV is in the plunger-depressed condition as shown in FIG. 5, poppet element 33 engages seat 41 as shown in FIG. 5, to thereby place port 35 in communication with port 36 whereby air may reach the brake release chambers of brake actuators 42 through line 43, the PV, and line 44.
A major feature of the invention is the provision of the TFV (trailer fill valve 5) within the brake system illustrated in FIGS. 10 to 13.
The TFV comprises a housing 51 and a manual plunger 52. The housing has a third port A connected by line 53 and another contiguous line, with air reservoirs 54,55. PV line 43 also ties into line 53. Port A is furthest of the three TFV ports from the handle 57 of the plunger. Of the two other ports of the TFV housing, port C is nearer to the handle end of the plunger. Port C is connected by line 58 to port 36 of the PV and the brake release chambers of rear tractor axle brake actuators 42. TFV port B is connected solely to TPCV relay air port 18 and is the sole source of pressure therefor.
Features of the TFV are (1) handle-depressed position of the plunger relative to the housing 51 at fully released condition of the air brakes of the entire rig; (2) non-rotatability of the plunger relative to the housing 51; (3) two-part construction of the housing and articulated construction of the plunger enabling low cost manufacturing of the TFV; (4) solely lateral porting of the TFV housing to conform with solely lateral porting of the TPCV and PV as a space saving feature; (5) simplified bore arrangement of two-piece valve housing; and (6) automatic depression of the TFV plunger when the TPCV plunger and the PV plunger are in depressed positions.
It is highly desirable to utilize the top surfaces of the knobs 57,61, and 62 as surfaces on which to imprint operating constructions for the TFV, PV and TPCV, respectively. For this reason, these knobs are made non-rotatable by the structure common to each valve but now described specifically with respect to the TFV. For non-rotatability of the plunger 52, the housing 51 is constructed with a generally cylindrical extension 65 surrounding a handle-receiving portion, i.e., shaft 66 of the plunger 52. A pin 67 extends transaxially through the shaft 66 and is of sufficient length to project radially beyond the outer surface of shaft 66 into grooves 68,69 extending longitudinally along the inner cylindrical surface 71 of the extension 65. The pin 67 has a further function in cooperation with an inner shoulder surface 72 of the housing 51 whereby the pin and the shoulder surface form a stop for the plunger defining its depressed or inner position relative to the housing.
In addition to the handle 57, the plunger 52 is constructed in three parts comprising in an order preceding away from the handle 57, shaft 66, an intermediate portion or bell 75, and a spool 76.
The housing 51 is constructed in a two-port portion 78 and a one-port portion 79 joined by a fastener means, such as cap screws, not shown, along a plane of separation at 81. The housing 51, in accommodating the plunger 52, has a central rectilinear passageway comprising in the order named, a first passageway portion adjacent the handle end of the plunger of smallest diameter complementary to the exterior surface of a first plunger portion, i.e., shaft 66, a second passageway portion of intermediate diameter at 83 conforming to the plunger's largest outer diameter, i.e., that of the second plunger portion or bell 75; a third passageway portion 84 of largest diameter of which its length overlaps portions of the lengths of the bell 75 and a spool 76 of the plunger, and a fourth passageway portion 85 furthest from the plunger handle having the same (intermediate) diameter as that of passageway portion 83 within which plunger spool 76 may reciprocate. The spool comprises the third and fourth portions 76a, 76b of the plunger separated by a neck 86. The largest diameter portion 84 of the passageway has flutes 88 and 89 at opposite ends having radially inner surfaces which lie along a surface of revolution of passageway portions 83 and 85.
The shaft 66 and the bell 75 of the plunger are joined by means, such as the male and female sections thereof in threaded relationship as shown in FIGS. 6 and 7. Since the shaft and the bell are of different diameters, a radially extending shoulder 91 is formed on bell 75 which engages housing shoulder 92 as stop means for the plunger at its retracted position.
The TFV plunger is specially constructed with lost motion means to allow for such imperfections in manufacturing as would cause slight eccentricity in portions of the housing passageway. Accordingly, the bell 75 is provided with a T-shaped tongue 95 which fits into a T-shaped recess or groove 96 of the spool 76. The recess is constructed to fit the tongue portion closely in an axial direction but loosely in all transaxial directions in order to allow spool 76 to adjust laterally with respect to the bell 75 in accommodating any eccentricity in the construction of the housing passageway. The plunger 52 is suitably grooved for receiving resilient O-rings 94,105,106 and 97 to seal adjacent regions of the valves from each other when subjected to different pressures.
The TFV is in its plunger-retracted condition as shown in FIG. 6. This is the condition of the TFV utilized in the brake system as illustrated in FIG. 11 when the rig is parked with the tractor rear-axle brakes set and the trailer brakes released. This condition of the TFV may be optionally assumed when the plungers of the TPCV and PV are retracted as shown in FIG. 12 to attain setting of the rear axle spring brakes of the tractor when the tractor is "bob-tailed", i.e., separated from a trailer. In the various figures illustrating any one of the valves, TPCV, PV, or TFV, the positions of the plungers are indicated by arrows drawn above handles 62,61 and 57. At plunger-retracted condition port A of the TFV communicates with port B through the undercut region 101 of the spool 76, the flutes 89, and the region surrounded by passageway surface 84.
At TFV plunger-depressed condition, as typified in FIG. 7, port C is placed in communication with port B through a region 104 opened up by separation of the plunger surface 91 and the housing surface 92, through the flutes 88, and region 102 of the passageway. Plunger-depressed condition of the TFV is utilized by the brake control system in road operation as illustrated in FIG. 10, or the parking situation as illustrated in FIG. 13, and optionally in FIG. 12.
FIG. 8 illustrative of a three-knob control module 100 comprising a tractor protection control valve 97, a parking valve 98, and trailer fill valve 99 of similar construction and operation to the TPCV, PV, and TFV of FIGS. 2 to 7, and adapted to substitute therefor in the system of FIGS. 10 to 13.
In attempting to understand the control system as depicted by FIGS. 10 to 13, it should be noted that the main function of the tractor protection control valve (TPCV) is to connect the main reservoir supply in the trailer with the tractor air supply in tanks 54,55 providing the TPCV has a signal pressure to its relay section from the trailer fill valve (TFV). The essential function of the parking valve (PV) is to unload the pressured brake-release chambers of the rear axle tractor brake actuators 42. During road operation of the rig, the PV assists the TFV in providing signal pressure to the TPCV relay section. The essential function of the trailer fill valve (TFV) is safety, i.e., the trailer reservoir system may be filled (which of necessity releases the trailer brakes) without releasing the towing vehicle park brake and thereby allowing an inadvertent roll away.
Observing now FIG. 10, when the rig is ready for road operation, all three handles are in the plunger-depressed (inward) position thereby enabling the TFV to transmit a signal pressure through line 111 to the TPCV which, with handle down, allows air to flow from its inlet port 11 to its outlet port 12 and then through line 110. The depressed handle of the PV enables pressure to be transmitted from the main tractor reservoirs through line 43, PV ports 38 and 36 and thence by line 58 to the brake-release chambers of actuators 42. Since line 58 also pressures TFV port C, pushing the PV handle inward will cause the TFV plunger 52, if outward, to automatically snap to its inward position as pressure acts on bell surface 91. When the plunger 52 is outward, ports A and B are connected and the plunger is otherwise under balanced pressure.
Referring now to FIG. 11, if it is desired to park the rig with only the rear tractor brakes set but the trailer brakes released, the valve handles are adjusted according to FIG. 11 wherein the PV handle is shown outward thereby allowing air to escape from the brake releasing chambers of actuators 42. Since the plunger-retracted PV is discharging to the atmosphere through PV port 37 with consequent zero pressure on port C of the TFV, the TFV handle 57 can be retracted to allow communication through ports A and B of the source pressure from tanks 54,55 with the relay section of the TPCV so as to maintain the function of the TPCV in supplying air through line 110 to the released brakes of the trailer.
In "bob-tailed" tractor operation (FIG. 12), i.e., without a trailer attached, the important condition of this system is that the TPCV handle be pulled outwardly (retracted) to assure that air from the tractor reservoirs will get no further than TPCV port 11 instead of its normal channel through outlet port 12 and line 110 to the trailer. At this setting of the TPCV, it is optional to have the plunger of the TFV either retracted or depressed. The retracted TFV handle places port A in connection with port B and pressure supply line 53 to "dead end" through line 111 in the signal chamber of the relay section of the TPCV. On the other hand, if the TFV handle 57 is pushed inward, ports B and C are in communication allowing the relay signal chamber to reach zero pressure and seating of the relay valve element 24 providing the PV plunger handle 61 is retracted to allow air to exhaust from actuators 42 through line 58 through PV port 37.
FIG. 13 illustrates the brake control system with handles 62, 61 and 57 adjusted for parking of the rig with the rear tractor axle brakes and the trailer brakes operative or set. The essential adjustment of the valve is that the PV handle be in its outward or retracted position and that the TFV handle be in its depressed or inward position. The TPCV handle may be in either position since in either case only the relay section of the TPCV is operative with element 24 seated to restrict any passage of air from supply port 11 to outlet port 12. The plunger depressed condition of the TFV places TFV ports B and C in communication to assure that air will drain from the relay signal chamber of the TPCV through the TFV and through the PV to exhaust through port 37. This causes retraction of the relay piston 21 which allows air to drain through line 110 from the trailer reservoir system through TPCV port 12 and outward of TPCV port 14. In this manner, valve adjustment according to FIG. 13 sets the brakes of both the tractor and the trailer. An operator may prefer the inward position of TPCV handle 62 in order to apply pressure internally of the valve to the relay element 24 tending to seat it more firmly. This practice is likely preferable from the standpoint that it requires the operator to retract only the PV handle 61 to attain complete park braking of the rig. | A tractor-trailer air-pressure brake system which includes a tractor protection control valve, a parking valve, and a trailer fill valve of special design provided for the purpose of achieving a desired non-confusing pattern of control positions whereby safety and convenience of brake operation is enhanced. | 8 |
FIELD OF THE INVENTION
The present invention relates generally to flight recording systems for aircraft and relates more specifically to a system for automatically recording engine fatigue cycles.
BACKGROUND OF THE PRESENT INVENTION
Aircraft turbine engine manufacturers have established various service life limits for the rotating parts of an engine based primarily on the number of repeated and/or alternating fatigue causing stress cycles undergone by the rotating parts. These fatigue or stress cycles result from transients of engine speed and temperature occurring during normal engine operation.
The manufacturers have defined a cycle as a flight consisting of the usual start, takeoff, landing and shutdown. Various less usual events have been given a weight as a full cycle or a fraction of a cycle. Thus, an air start is considered to be one cycle, while a landing without engine shutdown, followed by another flight, a touch and go landing or go around, or an advancement of throttle beyond 65%, when thrust reversing is used, each are counted as 1/6 cycle.
Presently, these stress cycles are kept track of by log entries by the pilot or copilot. Generally, also the records are not kept separately for each engine in a multi-engine aircraft resulting in unnecessary overhauls.
If a system could be found which would automatically keep track of stress cycles, a great deal of accuracy would result. Furthermore, if the stress cycles undergone by each engine of a multi-engine aircraft were monitored separately, unnecessary overhauls would be eliminated.
OBJECTS OF THE INVENTION
It is a primary object of the present invention to provide an accurate and automatic system for monitoring and recording engine stress cycles.
It is a further object of the present invention to provide a system for individually monitoring and recording the stress cycles undergone by each engine of a multi-engine aircraft.
SUMMARY OF THE PRESENT INVENTION
Briefly, the aforementioned objects are achieved by providing sensors in the aircraft for sensing engine starting, engine shutdown, landing gear status, engine reversal and throttle setting. From the outputs of these sensors there are derived signal indications of when the aircraft is in flight and when the landing gear drop in flight. The occurrence of a full or fractional cycle is derived from these signal indications and from the sensor outputs. Counters for each engine are automatically incremented at the completion of a stress cycle.
Other objects, features and advantages of the present invention will become apparent upon a perusal of the following detailed description of one embodiment of the present invention when taken in conjunction with the appended drawing wherein:
FIG. 1 is a block diagram illustrating a display box and various sensors for the left and right engines of a two engine aircraft.
FIG. 2 is a block diagram illustrating the logic circuitry within the display box in combination with the sensors for the left engine. The circuitry for the right engine is identical.
DETAILED DESCRIPTION
FIG. 1 depicts a display and logic box 10 responsive to various sensors for automatically counting and displaying engine stress cycles for the left and right engines of an illustrative two engine jet aircraft. There are respectively five digit decimal cycle unit displays 12 and 14 and one digit fractional displays 16 and 18 in sixths of a cycle, for the left and right engine.
In order to individually keep track of the stress cycles for each engine, there are a set of sensors for each. For the left engine there are fed to box 10 contacts from the starter or ignition switch 20 and the shutdown switch 22. Also a thrust reverser sensor 24 is provided to sense when the left engine is reversed. The right engine similarly has contacts from starter switch 26 and shutdown switch 28 fed to box 10 as well as the output from thrust reverser sensor 30.
Also a landing gear sensor 32 has its output, indicative of whether the landing gear are up or down, fed to box 10. Lastly, a throttle sensor 34, which may be a potentiometer with a variable resistance indicative of the throttle setting, has its output fed to box 10.
Now reference is made to FIG. 2, which shows a block diagram of the contents of box 10 in combination with the various sensors, will be referred to in order to explain how the sensor outputs are utilized to automatically count and display stress cycles for each engine. The circuitry for the left engine is illustrated in FIG. 2 with the understanding that the circuitry for the right engine is identical and would therefore involve much repetition of description.
As previously explained, starting, takeoff, landing and shutdown count as one cycle while starting, takeoff, landing and retakeoff without engine shutdown count only as 1/6 cycle. In the logic circuitry the occurrence of various events are stored and the occurrence of a cycle is derived from the stored signal indications.
Thus the output 36 of starter switch 20 is fed to the set input 38 of a flip-flop memory 40 via one shot 42 while the output 44 of shutdown switch 22 is fed to the reset input 46 of flip flop 40 via one shot 48. As a result the Q output 50 of flip-flop 40 provides an indication of when the engine is running, i.e., Q output 50 is digital one only when the engine has been started and hasn't subsequently been shut down.
For providing a indication of when the aircraft is in flight, the output 52 of landing gear sensor 32 which is digital one when the landing gear are up is used in connection with Q output 50. Outputs 50 and 52 are fed to AND gate 54, whose output 56 is digital one when both the engine is running and the gear are up.
For providing a digital indication of when a start, takeoff and landing have sequentially occurred, another output 58 of landing gear sensor 32 is utilized in combination with output 56. Output 58 is applied via one shot 60 to one input of AND gate 62. The other input of AND gate 62 is fed by output 56 via a delay 64. It should be understood that the pulse width outputs of each of the one shots employed are preferably of the same lengths and that the delays of elements 64 and 84 are longer than the one shot pulse widths. Thus upon falling of the landing gear with the plane in flight a digital one pulse will appear at the output 66 of AND gate 62. While the output 56 of AND gate 54 will change state simultaneously with the leading edge of the aforementioned digital one pulse, this change of state is sufficiently delayed by delay 64 so as not to inhibit the appearance of the pulse at AND gate output 66.
Output 66 is fed to the set input 68 of flip-flop 70. Thus upon the dropping of the landing gear in flight, flip-flop 70 will be set and its Q output 72 will be digital one. Thus, flip-flop 70 constitutes a memory element whose output 72 is digital one when there has been an engine start, a takeoff and then a landing.
Output 72 is applied in parallel to a pair of AND gates 74 and 76 which respectively direct the digital one indication of, output 72 to either increment units counter 12 or fractions counter 16 depending upon whether the landing is followed by a shutdown or by a re-takeoff without intermediate shutdown.
In the event of engine shutdown, the other input of AND gate 74 is fed from shutdown switch output 44 via one shot 48 to gate a digital one pulse through to the output 78 of AND gate 74. For resetting flip-flop 70 subsequent to the pulse, the output 80 of one shot 48 is fed to the reset input 82 of flip-flop 70 via delay 84.
In the event of retakeoff without intermediate engine shutdown, a digital one pulse appears not at the output of AND gate 74 but at the output 84 of AND gate 76. This is accomplished by feeding the landing gear sensor up - indicating output 52 to the other input of AND gate 76 via one shot 86.
AND gate 76 output 84 is applied to one input 88 of two input OR gate 90. The other input 92 of OR gate 90 is fed from circuitry yet to be described which derives a digital one pulse if the throttle exceeds 65% during thrust resensor operation. The output 94 of OR gate 90 drives a buffer amplifier 96 which in turn drives the electromechanical fractions counter 16. To mechanize a carry pulse to electromechanical units counter 12 when the fractions counter 16 goes from 5/6 to 0/6, output 94 also feeds a six digit electronic counter 98 whose overflow output 100 feeds electromechanical units counter 12 via OR gate 102.
For incrementing units counter 12 in the event of a start, takeoff, landing and shutdown, AND gate 74 output 78 is fed to input 104 of three input OR gate 102. The other inputs 106 and 108 to OR gate 102 are respectively fed from circuitry yet to be described which generates a digital one pulse in the event of an air start and from the overflow output 100 of counter 98. The output 110 of OR gate 102 drives electromechanical units counter 12 via buffer amplifier 112.
In order to increment units counter 12 when there is an air start, the output 114 of one shot 42, which is fed by starter switch 20, is applied to one input 116 of AND gate 118. The other input 120 of AND gate 118 is fed by the output 122 of delay 64 which provides an indication of when the aircraft is in flight. As a result, the output 122 of AND gate 118 provides a digital one pulse when an air start is attempted. Output 122 feeds input 106 of OR gate 102 for suitably incrementing counter 12.
For incrementing fractions counter 16 in the event of greater than 65% throttle being used during thrust reversal, the output 124 of throttle sensor 34 is applied to an electronic comparator or limit switch 126 which provides at its output 128 a digital one indication of when 65% throttle is exceeded. Output 128 is applied via one shot 130 to one input 132 of three input AND gate 134. Input 136 of AND gate 134 is fed from thrust reverser sensor 24 output 138 which provides a digital one indication when the engine is reversed. As an optional feature, input 140 of AND gate 134 may be fed from landing gear down-indicating output 58. Thus, AND gate 134 output 142 provides a digital one pulse when the thrust reverser is used, 65% throttle is exceeded and the landing gear are down. For incrementing the fractions counter in such event, output 142 is applied to OR gate 90 input 92.
It should now be appreciated what has been described is a completely automatic system for incrementing units counter 12 in the event of either a start, takeoff and landing cycle or an air start and for incrementing fractions counter 16 in the event of either a retakeoff without engine shutdown, or when the throttle exceeds a predetermined setting when the thrust reverses are used during landing. It should furthermore be appreciated to those skilled in the art that since the deployment of the landing gear are considered indicative of a landing, a touch and go landing or turn around will be treated by the circuitry as a retakeoff without shutdown and will consequently register the proper 1/6 cycle increment.
Having described one embodiment of the present invention it should be appreciated that numerous other embodiments are possible within the spirit and scope of the invention. | In an aircraft, a system for recording aircraft fatigue cycles senses engine starting, engine shutdown, landing gear status, engine reversal and throttle setting and derives therefrom unit and fractional cycles. The system includes a first memory responsive to the aforementioned sensors for producing an indication of when the aircraft is in flight and a second memory for producing an indication of when the landing gear are dropped in flight. These memory indications are fed to gates which index the units counter when a takeoff, landing and engine shutdown cycle is completed and which index the fractions counter when a retakeoff without engine shutdown is accomplished. Other gates cause the units counter to be indexed when the engine is restarted in flight. In a multi-engine aircraft, sensors and counters are provided individually for each engine. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the game of golf and, more particularly, to configurations and methods to distinguish between golf clubs in a set of golf clubs.
2. Description of the Related Art
Mastering the game of golf is an endless pursuit for millions of people around the world. To master the game, one must not only conquer the physical aspects of the game but must also conquer the mental aspect of the game. One important step in mastering the mental aspect of the game is to identify the appropriate shot to play from a particular distance given the ball's particular lie with, of course, consideration given to the layout of the golf course. A wide variety of golf shots are available. The golfer may choose from a full swing, a flop shot, a lob shot, a chip shot, a sand shot, a pitch shot, a punch shot or other shot that may be available in that golfer's arsenal. Each shot confers various advantages given the lie of the ball and will also determine the speed and trajectory of the ball as it leaves the face of the club head. Thus, the shot chosen will depend on many factors, including: the distance to the pin; the existence of any obstructions such as tree limbs; the environmental conditions, most notably wind velocity; and the lie of the ball, most notably whether the ball is in the sand or on the rough, fairway, fringe or green and whether the ball is on a flat or an angled surface. However, the calculus does not end with the selection of the shot to be used, the golfer must also identify the appropriate club that he or she has available to execute the chosen shot. If the golfer chooses his or her club properly and executes the shot correctly, the ball will take the desired course which typically avoids obstacles and sends the ball in the general direction of the pin.
Unfortunately, proper club identification does not always result in proper club selection. Golfers carry a wide variety of clubs in their bags. If the golfer plays by the rules, the golfer will have no more than 14 clubs in his bag. Ideally, the particular clubs carried by any given golfer are selected to best suit the attributes of that particular golfer's game. The clubs selected by most golfers include a driver, one or more fairway woods, nine or more irons and a putter. From these clubs, the golfer identifies what that golfer feels is his or her strongest club for a particular shot. The bags holding the clubs are generally designed to be relatively compact so that they may be carried by the golfer and are typically configured to receive the handle and shaft of a club leaving the head exposed for club identification. Due to the generally compact design of golf bags and the relatively large number of clubs to be carried, the club heads are generally crowded together and tend to overlap one another. This crowding and overlapping can make the selection of a particular club difficult and frustrating. During the course of a round, a scratch golfer will identify and select an average of seventy two clubs. This results in seventy two opportunities to identify or select the wrong club from one's bag. Although a misidentification of a club for a particular golf shot should be correctable through practice and lessons, the erroneous selection of a club when the proper club had been identified only frustrates the golfer, increasing his or her score and typically facilitating the breakdown of his or her mental game. Thus, the golfer's enjoyment of the game is reduced. Therefore, a need exists for a set of clubs that enables a golfer to more easily and consistently select an identified club.
The similarity in appearance between the various clubs makes the club selection even more difficult. There are only subtle structural differences among the various woods (including the driver) and among the various irons. The differences include slight differences in the size and shape of the club heads as well as differences in the lengths of each club's shaft. However, as noted above, the golf bag receives the shaft (and grip) of each golf club. Thus, only the head of each golf club is typically extending from a golf bag when a club is selected for a shot. This orientation of the clubs in the bag eliminates the shaft length as a distinguishing factor for the golfer and leaves only the subtle differences in the club heads to facilitate identification. Further, the club heads extend from the golf bag at various angles further distorting their appearance and obscuring the various visual clues that aid a golfer in selecting between clubs. Further with a primary difference between the shapes of clubs being their loft, the various angles at which the club heads sit within the bag make proper identification based on the loft of a club almost impossible. Therefore, a need exists for a set of clubs that can be distinguished from one another based on more than just club head size and shape.
Various apparatus and methods have evolved to allow golfers to properly identify the desired club. However, these systems typically require a golfer to identify a number stamped or molded on the sole of the club or to identify a number on a club head cover. In addition, other more technically complicated systems allow the push button identification and mechanical extension of the identified club head above the other clubs in a users bag to aid in selection. However, these apparatus and methods have particular drawbacks.
Generally, golf clubs are identified by numbers or letters stamped or molded into the sole plate of the club head. The numbers and letters are generally recessed into the sole to prevent them from wearing off over time. The numbers' placement typically allows the club to be identified when the club is inverted, such as the club would be when the club was placed in a golf bag. However, due to the nature of various numerals in addition to the “P” and “S” frequently used on pitching wedges and sand wedges, respectively, there can be some confusion as to the club identified by the number or letter. Particularly, the 6 and 9 irons, and the pitching wedge are easily confused. Similarly, the 2 and 5 irons, and the sand wedge are also easily confused. In addition, the 3 and 8 irons can easily be confused by a golfer. Furthermore, as the clubs typically rest in a golf bag, the club heads frequently overlap. This overlap tends to obscure the numbering and lettering on the soles of the club heads. Thus, a golfer attempting to select an identified club must fumble through the club heads to find and select the identified club. Aside from the frustration of having to search for the club, the golfers fumbling about brings the club heads into contact with one another resulting in excess wear to the club heads from the repeated searches. Therefore, a need exists for a set of clubs and method for club differentiation that does not solely rely on numbering or lettering for proper club selection.
In addition to the confusion between numbers and letters on the sole of the golf clubs, the numbers and letters can affect the swing of a club. As noted above, the numbers or letters are typically stamped or molded into the sole of the club head. That is, the numbers and letters are recessed into the sole of the club head. When the club is swung and the sole contacts the ground, there are necessarily variations in the resistance to the movement of the club along the ground in the golfer's swing plane. These differences in resistance can cause variations in the same swing with the different numbering and lettering on the clubs, thereby reducing a golfers consistency. Thus, a need exists for a method of club identification that does not necessarily require the stamping or molding of numbers and/or letters into the sole of a club head to eliminate the variation in resistance between clubs as their soles contact the ground.
Further, the nature of golf is that it is typically played outside on natural turf and other natural groundcovers that tend to bring the sole of the club head into contact with dirt and other debris. Ideally, the dirt is cleaned from the club head after every shot. However, typically dirt is compacted into the recessed numbering and/or lettering on the soles of the club heads. This obscures the numbering and/or lettering making it more difficult to properly distinguish the clubs from one another and thus, more difficult to select the proper club. Therefore, a need exists for a set of clubs and method for club differentiation that is not compromised when the sole of the club is dirty.
Another apparatus and method for identifying the proper golf club are designations on club head covers. Frequently, club head covers are provided to protect the finish and allow for identification and selection of clubs. However, head covers can be cumbersome. They are frequently difficult to remove from the club head and to replace over the club head frustrating the golfer and increasing the amount of time required to finish the round. In addition, the club head covers can be placed on the wrong club causing the player to select the improper club. Further, club head covers may be left on an earlier hole and are frequently lost during the course of a round as the player forgets to replace the head cover after a shot, again frustrating the golfer. Therefore, a need exists for a set of clubs and method for club differentiation that does not add to the equipment that must be carried around the course and that can not be separated from the club head so that it may be forgotten at a hole or lost.
Yet another apparatus and method for selecting the proper club are electronic club dispensers. These club dispensers are typically integral with the golf bag and in some cases provide a touch pad to extend a club for selection. That is, once a club is identified on the touch pad, the club is mechanically raised above the other clubs to allow for simplified selection. Although this system simplifies the selection of the clubs, it typically requires that a club be replaced at a particular location within the bag. This placement requires a degree of concentration that a golfer would likely not want to dedicate to placing a golf club within a golf bag and misplacement of a club results in the wrong club being presented for subsequent selection. In addition, such golf bags are complicated and expensive to manufacture. Their complicated nature invites component failure decreasing golfer satisfaction with both the equipment and game. In addition, golf bags with electronic club dispensers tend to be heavier than standard bags. This extra-weight is extremely undesirable especially to golfers who carry their clubs or use a pull cart to transport their clubs around the course. Therefore, a need exists for a set of clubs and method for club differentiation that is not complicated or expensive to manufacture and that does not add to the weight of the equipment that a golfer must transport around the course.
SUMMARY OF THE INVENTION
The present invention meets the above needs and provides additional improvements and advantages that will be recognized by those skilled in the art upon their review of the following specification and figures. The present invention provides a sports set including a plurality of golf clubs with each club or subsets of clubs having a distinct surface configuration to allow a user to distinguish between the clubs or subsets of clubs. The sports set may include at least one wood and at least one iron, may include at least two woods, or may include at least two irons. In a preferred aspect, the sports set includes at least nine irons. In another preferred aspect, the sports set of irons is broken down into a first subset including long irons, a second subset including the middle irons, and a third subset including the short irons.
Generally, each golf club includes a shaft, a grip, and a head. The grip is secured to a first end of the shaft and the head is secured to a second end of the shaft. The head is divided into separate regions includes including a face, a rear side, a toe, a heel, a sole, and a top. The head as a whole and individually each region includes an outer surface. At least a portion of the outer surface has a surface configuration. The surface configuration is provided to distinguish each golf club from other golf clubs or subset of golf clubs from the other subsets of clubs. The surface configuration may be a distinct color. The surface configuration comprising a distinct color to distinguish the each subset golf club from the other subsets golf clubs in the plurality of golf clubs. In another aspect, the surface configuration of each club within each subset of clubs includes distinct hues or shades of the distinct color for the particular subset.
It is thus an object of the present invention to provide such novel apparatus and methods for differentiating between golf clubs in a set of clubs.
It is further an object of the present invention to provide such novel apparatus and methods which allows the differentiation between golf clubs without solely having to rely on the numbering or lettering on the golf club.
It is further an object of the present invention to provide such novel apparatus and methods for club differentiation that are not compromised when the sole of the clubs are covered with debris.
It is further an object of the present invention to provide such novel apparatus and methods for club differentiation that does not add to the equipment that must be carried around the golf course.
It is further an object of the present invention to provide such novel apparatus and methods for club differentiation that can not be separated from the club head so that it may be forgotten at a hole or otherwise separated from the set of golf clubs.
It is further an object of the present invention to provide such novel apparatus and methods for club differentiation that can be simple to manufacture and maintain.
It is further an object of the present invention to provide such novel apparatus and methods for club differentiation that is inexpensive to manufacture and that does not add to the weight of the equipment that a golfer must transport around the course.
These and other objects, features, and advantages of the present invention will become more readily apparent from the following detailed description of the preferred embodiment of the invention when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
The illustrative embodiment may best be described by reference to the accompanying drawings where:
FIG. 1A illustrates a perspective view of an embodiment of a golf club in accordance with the present invention in the form of a wood;
FIG. 1B illustrates a perspective view of an embodiment of a golf club in accordance with the present invention in the form of an iron;
FIG. 2A illustrates a partial perspective view of an embodiment of a golf club in accordance with the present invention in the form of a wood having all of the exterior surface in a first surface configuration except for the face;
FIG. 2B illustrates a partial perspective view of an embodiment of a golf club in accordance with the present invention in the form of a wood having all of the exterior surface in a second surface configuration except for the face;
FIG. 2C illustrates a partial perspective view of an embodiment of a golf club in accordance with the present invention in the form of an iron having all of the exterior surface in a third surface configuration except for the face;
FIG. 2D illustrates a partial perspective view of an embodiment of a golf club in accordance with the present invention in the form of an iron having all of the exterior surface in a fourth surface configuration except for the face;
FIG. 3A illustrates a partial perspective view of an embodiment of a golf club in accordance with the present invention in the form of a wood having the exterior surface of the sole of the club head in a first surface configuration;
FIG. 3B illustrates a partial perspective view of an embodiment of a golf club in accordance with the present invention in the form of a wood having the exterior surface of the sole of the club head in a second surface configuration;
FIG. 3C illustrates a partial perspective view of an embodiment of a golf club in accordance with the present invention in the form of an iron having the exterior surface of the sole of the club head in a third surface configuration;
FIG. 3D illustrates a partial perspective view of an embodiment of a golf club in accordance with the present invention in the form of an iron having the exterior surface of the sole of the club head in a fourth surface configuration;
FIG. 4A illustrates a partial perspective view of an embodiment of a golf club in accordance with the present invention in the form of a wood having the exterior surface of the top of the club head in a first surface configuration;
FIG. 4B illustrates a partial perspective view of an embodiment of a golf club in accordance with the present invention in the form of a wood having the exterior surface of the top of the club head in a second surface configuration;
FIG. 4C illustrates a partial perspective view of an embodiment of a golf club in accordance with the present invention in the form of an iron having the exterior surface of the top of the club head in a third surface configuration;
FIG. 4D illustrates a partial perspective view of an embodiment of a golf club in accordance with the present invention in the form of an iron having the exterior surface of the top of the club head in a fourth surface configuration;
FIG. 5A illustrates a partial perspective view of an embodiment of a golf club in accordance with the present invention in the form of a wood having the exterior surface of the toe, heel, and shaft in a first surface configuration;
FIG. 5B illustrates a partial perspective view of an embodiment of a golf club in accordance with the present invention in the form of a wood having the exterior surface of the toe, heel, and shaft in a second surface configuration;
FIG. 5C illustrates a partial perspective view of an embodiment of a golf club in accordance with the present invention in the form of an iron having the exterior surface of the toe, heel, and shaft in a third surface configuration; and
FIG. 5D illustrates a partial perspective view of an embodiment of a golf club in accordance with the present invention in the form of an iron having the exterior surface of the toe, heel, and shaft in a fourth surface configuration.
All figures are drawn for ease of explanation of the basic teachings of the present invention only; the extensions of the figures with respect to number, position, relationship and dimensions of the parts to form the preferred embodiment will be explained or will be within the skill of the art after the following description has been read and understood. Further, the exact dimensions and dimensional proportions of a set of golf clubs in accordance with the present invention will likewise be within the skill of the art after the following description has been read and understood.
Where used in various figures of the drawings, the same numerals designate the same or similar parts. Furthermore, when the terms “top,” “bottom,” “right,” “left,” “forward,” “rear,” “first,” “second,” “inside,” “outside,” and similar terms are used, the terms should be understood to reference only the structure shown in the drawings as it would appear to a person viewing the drawings and utilized only to facilitate describing the illustrated embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1A and 1B illustrate a wood 10 and an iron 12 , respectively, from a set of golf clubs in accordance with the present invention. The following description will reference these clubs individually as wood 10 and iron 12 or jointly as clubs 10 and 11 , as appropriate for ease of description. A regulation set of clubs 10 and 11 , as determined by the professional golfer's associations, includes fourteen clubs. The set generally includes a plurality of woods 10 , nine or more irons, and a putter (not shown). The woods 10 typically carried by a golfer include a driver and one or more fairway woods. The irons 12 carried by a golfer typically include a 3 iron through sand wedge. Other specialized clubs (not shown) that are adapted to assist the golfer in particular situations may also be included in the set of clubs.
Regardless of the club type, golf clubs 10 and 12 are generally configured to permit the golfer to strike a ball by swinging the club. To accomplish this, golf clubs 10 and 12 include a grip 14 , a shaft 16 and a head 18 . Grip 14 is secured to shaft 16 . Grip 14 is placed at a location along shaft 16 to permit a golfer to allow a golfer to swing either of clubs 10 or 12 to strike a golf ball. Typically, grip 14 is positioned adjacent one of the ends of shaft 16 . Head 18 is attached to shaft 16 , typically at an end opposite of the end on which grip 14 is attached to the shaft. Head 18 is generally configured to strike the ball on a face 20 of head 18 . Head 18 is typically formed from one or more metals or alloys of metals, wood, or combinations of wood and metal. The head 18 also includes an outer head surface. The outer head surface comprising the external surface of club head 18 . In accordance with the present invention, the outer head surface is provided with a surface configuration 34 that is distinct for each head or for a particular group of heads 18 within the set of golf clubs. Shaft 16 is an elongated structure typically round in cross section that enables a user to transfer force from grip 14 held in a user's hands to head 18 which contacts the golf ball as the club is swung. Thus, shaft 16 is formed from a material having sufficient strength to withstand the forces conferred by a golfer to grip 14 to accelerate club head 18 . Shaft 16 is typically formed from a metal, an alloy of a metal or graphite.
Head 18 is generally configured to contact the ball as the golfer swings the club to which head 18 is secured. Structurally, head 18 includes a face 20 , a rear side 22 , a toe 24 , a heel 26 , a sole 28 , and a top 30 , as shown in FIGS. 2A to 5D . Face 20 of the club is, optimally, the portion of club head 18 that strikes the ball as the golfer swings the club. Face 20 typically includes a plurality of grooves 32 to allow better control of the ball by the golfer. The remainder of head 18 is generally shaped and weighted to facilitate accurate and precise ball striking.
In addition, head 18 has a distinct surface configuration 34 visible on the outer surface of head 18 . Distinct surface configuration 34 is provided to allow the golfer to distinguish a club or a subset of clubs from the other clubs in his or her set of clubs. Surface configurations 34 shown in FIGS. 2A to 5D are illustrated as distinct colors for exemplary and ease of illustration purposes only. In one aspect of the invention, surface configuration 34 may be a distinct coloration provided on the outer surface of club head 18 . The coloration may be any of a variety of colors, shades, hues, tints or other variations in color that enable a golfer to distinguish between surface configurations 34 of different clubs or groups of clubs within a set of clubs. In another aspect of the invention, the surface configuration 34 of the outer head surface may be a distinct pattern or design provided on the outer surface of club head 18 . The distinct pattern or design could include cross hatching, herring bone, chevron, polka dot, or other variations in pattern or design that would enable a golfer to distinguish between surface configurations 34 . Further, the outer head surface may be subdivided to correspond to each region or component of head 18 wherein only particular regions or components include distinctive surface configuration 34 .
Generally, the surface configuration 34 is provided on club head 18 to allow the golfer to identify and select the proper club 10 or 12 from a golf bag containing a plurality of inverted golf clubs 10 and 12 . For example, head 18 may be provided with a distinctive surface configuration 34 only on sole 28 of head 18 as illustrated in FIGS. 3A to 3D . In addition or alternatively, surface configuration 34 may be provided on head 18 to allow the golfer to confirm his or her proper club selection as the golfer stands above club 10 or 12 in preparation for striking the ball. For example, head 18 may be provided with a distinctive surface configuration 34 only on top 30 of head 18 as illustrated in FIGS. 4A to 4D . To allow a golfer to identify and select the proper club 10 or 12 from a golf bag containing a plurality of inverted golf clubs 10 and 12 and to confirm his or her proper club selection as the golfer stands above club 10 or 12 in preparation for striking the ball, both sole 28 and top 30 of head 18 may have a distinctive surface configuration 34 or the entire outer surface of head 18 may include a distinctive surface configuration 34 .
In one embodiment, the present invention may provide a set of golf clubs with each golf club having a distinct surface configuration 34 . This embodiment allows a golfer to distinguish between each club individually based on the surface configuration 34 .
In another embodiment, the present invention may provide a set of nine irons 12 , for example, divided into subsets, such as for example the subsets of long irons (3 iron to 5 iron), middle irons (6 iron to 8 iron) and short irons (9 iron to sand wedge). In this embodiment, each subset would be provided with a particular surface configuration 34 to distinguish the particular subsets of irons 12 from one another. If a color was used as a surface configuration 34 , each iron 12 within the subset could be the same color or each iron 12 or wood 10 in the subset could be different shades or hues of a color to allow a golfer to distinguish between individual clubs within a subset.
The surface configuration 34 of the outer surface may include any surface configuration 34 so long as the surface configuration 34 of each club head in a set of clubs is sufficiently distinct to allow a golfer to distinguish between the clubs based on the surface configuration 34 . In one exemplary embodiment, the surface configuration 34 on the outer head surface may comprise one or more layers of paint over the outer head surface. In another exemplary embodiment, the surface configuration 34 on the outer head surface may comprise the outer head surface being anodized with a chosen color. In yet another exemplary embodiment, the surface configuration 34 on the outer head surface may comprise a design or pattern molded, etched, painted or otherwise formed on the outer head surface. Regardless of the particular embodiment, the surface configuration 34 is selected and formed to permit a golfer to distinguish a particular club 10 or 12 from other clubs in the golfer's bag.
Furthermore, each shaft 16 has an outer shaft surface that may also include a surface configuration 34 that may correspond to the surface configuration 34 of the head and that is distinct from the surface configuration 34 of the other shafts in the set of golf clubs to further aid a golfer in distinguishing between the various clubs 10 and 12 in a set of golf clubs.
FIGS. 2A to 2D illustrate one embodiment for a set of clubs in accordance with the present invention. In the embodiment of FIGS. 2A to 2D , the entire outer surface except for face 20 of each club head 18 of clubs 10 and 12 has a surface configuration 34 to distinguish each of the clubs from the other clubs in the set. The wood 10 of FIG. 2A is shown having a surface configuration 34 wherein the outer surface is blue in color. The wood 10 of FIG. 2B is shown having a surface configuration 34 wherein the outer surface is red in color. The iron 12 of FIG. 2C is shown having a surface configuration 34 wherein the outer surface is green in color. The iron 12 of FIG. 2D is shown having a surface configuration 34 wherein the outer surface is brown in color. The surface configuration 34 of each head 18 is illustrated as a different color for exemplary purposes and is in no way intended to limit the variations in surface configurations 34 to distinct colors.
FIGS. 3A to 3D illustrate another embodiment for a set of clubs in accordance with the present invention. In the embodiment of FIGS. 3A to 3D , sole 28 of each club 10 and 12 has a surface configuration 34 to distinguish each club 10 or 12 from other clubs 10 and 12 in the set. The wood 10 of FIG. 3A is shown having a surface configuration 34 wherein the outer surface of sole 28 of head 18 is red in color. The wood 10 of FIG. 3B is shown having a surface configuration 34 wherein the outer surface of sole 28 of head 18 is green in color. The iron 12 of FIG. 3C is shown having a surface configuration 34 wherein the outer surface of sole 28 of head 18 is brown in color. The iron 12 of FIG. 3D is shown having a surface configuration 34 wherein the outer surface of sole 28 of head 18 is yellow in color. Again, the surface configuration 34 of each sole 28 is illustrated as a different color for exemplary purposes and is in no way intended to limit the variations in surface configurations 34 to distinct colors.
FIGS. 4A to 4D illustrate yet another embodiment of a set of clubs in accordance with the present invention. In the embodiment of FIGS. 4A to 4D , the top of each club 10 and 12 has a surface configuration 34 to distinguish each of the clubs from the other clubs in the set. The wood 10 of FIG. 4A is shown having a surface configuration 34 wherein the outer surface of top 30 of head 18 is green in color. The wood 10 of FIG. 4B is shown having a surface configuration 34 wherein the outer surface of top 30 of head 18 is orange in color. The iron 12 of FIG. 4C is shown having a surface configuration 34 wherein the outer surface of top 30 of head 18 is red in color. The iron 12 of FIG. 4D is shown having a surface configuration 34 wherein the outer surface of top 30 of head 18 is blue in color. Again, the surface configuration 34 is illustrated as different colors for exemplary purposes and is in no way intended to limit the variations in surface configurations 34 to distinct colors.
FIGS. 5A to 5D illustrate still yet another embodiment of a set of clubs in accordance with the present invention. In the embodiment of FIGS. 5A to 5D , the top of each club 10 and 12 has a surface configuration 34 to distinguish each of the clubs from the other clubs in the set. The wood 10 of FIG. 5A is shown having a surface configuration 34 wherein the outer surface of a toe 24 and a heel 26 of head 18 , and the outer shaft surface of shaft 16 are brown in color. The wood 10 of FIG. 5B is shown having a surface configuration 34 wherein the outer surface of a toe 24 and a heel 26 of head 18 , and the outer shaft surface of shaft 16 are green in color. The iron 12 of FIG. 5C is shown having a surface configuration 34 wherein the outer surface of a toe 24 and a heel 26 of head 18 , and the outer shaft surface of shaft 16 are blue in color. The iron 12 of FIG. 5D is shown having a surface configuration 34 wherein the outer surface of a toe 24 and a heel 26 of head 18 , and the outer shaft surface of shaft 16 are orange in color. Again, the surface configuration 34 is illustrated as different colors for exemplary purposes and is in no way intended to limit the variations in surface configurations 34 to distinct colors.
The present invention as described-above may be embodied in other specific forms without departing from the spirit or general characteristics of the invention. Only selected representative forms have been indicated, the embodiments described herein are to be considered in all respects illustrative and not restrictive. The scope of the invention is to be indicated by the appended claims, rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein. | A sport set ( 10 ) and methods for golf club identification are provided. The sports set ( 10 ) includes a plurality of clubs ( 10 and 12 ) with each club ( 10 or 12 ) or subset of the plurality of clubs ( 10 or 12 ) provided with a distinguishing surface configuration on at least a portion of the exterior surface of head ( 18 ) to enable a golfer to visually distinguish between each club ( 10 or 12 ) or between subsets of clubs ( 10 or 12 ). | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to vehicle wheel differentials and, in particular, to a brake assembly for use with the differential.
2. Disclosure of the Related Art
A conventional drive axle assembly for driving one or more wheels on opposite sides of a vehicle includes a drive axle comprised of two axle half shafts. The axle assembly further includes a differential that drives the axle half shafts and enables the shafts to rotate at different speeds. The axle assembly further includes two separate braking devices used to brake the wheel or wheels driven by the respective axle half shafts.
The use of multiple braking devices to brake the driven wheels has several disadvantages. For example, the use of multiple braking devices requires additional parts and materials and increases assembly time-all of which increase the cost of the drive axle assembly. The use of multiple braking devices also increases the size and weight of the drive axle assembly.
U.S. Pat. No. 3,994,375 illustrates the use of a single brake assembly for use in braking the wheels on both sides of the drive axle. The disclosed brake assembly, however, still requires the use of multiple actuators and significantly increases the size of the axle and differential housings thereby creating potential interference with other vehicle components.
There is thus a need for a brake assembly that will minimize or eliminate one or more of the above-mentioned deficiencies.
SUMMARY OF THE INVENTION
The present invention provides a brake assembly for a drive axle.
A brake assembly for a drive axle in accordance with the present invention includes a brake housing. The brake housing may be coupled to a differential carrier that is disposed about a first axis and the brake housing may include a first portion extending radially and a second portion extending axially from the first portion. The brake assembly also includes a differential hub that is coupled to the differential carrier and is axially movable relative to the differential carrier and the brake housing. The brake assembly further includes first and second friction plate assemblies. The first friction plate assembly is disposed on a first side of the differential hub between the differential hub and the brake housing and is axially movable relative to the differential carrier and the brake housing. The second friction plate assembly is disposed on a second side of the differential hub and is also axially movable relative to the differential carrier. Finally, the brake assembly includes a piston that selectively urges the second friction plate assembly, the differential hub, and the first friction plate assembly in a first axial direction against the brake housing. The inventive brake assembly both provides locking capacity to the differential, thereby preventing or limiting the two axle half shafts of the drive axle from rotation at different speeds, and provides braking capacity to the axle half shafts for stopping the vehicle.
A brake assembly in accordance with the present invention represents a significant improvement as compared to conventional drive axle brake assemblies. In particular, the use of a single brake assembly to brake the driven wheels reduces the number of parts and materials required as compared to conventional drive axle assemblies and decreases assembly time thereby reducing the cost of the drive axle assembly. The use of a single brake assembly also decreases the size and weight of the drive axle assembly relative to conventional drive axle assemblies.
These and other features and objects of this invention will become apparent to one skilled in the art from the following detailed description and the accompanying drawings illustrating features of this invention by way of example.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of a drive axle assembly.
FIG. 2 is a partial cross-sectional view of the drive axle assembly of FIG. 1 illustrating a brake assembly in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings wherein like reference numerals are used to identify identical components in the various views, FIG. 1 illustrates a drive axle assembly 10 disposed about an axis 12 . Assembly 10 is provided to drive one or more wheels disposed at either axial end of assembly 10 . The illustrated assembly 10 is configured for use with an off-highway vehicle. It should be understood, however, that the present invention may find use in wide variety of conventional vehicles. Assembly 10 includes axle half shafts 14 , 16 and a differential 18 . Referring to FIG. 2, assembly 10 may also include a brake assembly 20 in accordance with the present invention.
Referring again to FIG. 1, shafts 14 , 16 are provided to transfer torque to one or more vehicle wheels disposed at either axial end of assembly 10 . Shafts 14 , 16 are conventional in the art and may be disposed within an axle housing 22 .
Differential 18 is provided to allow shafts 14 , 16 , and wheels, to rotate at different speeds. Differential 18 is also conventional in the art. Referring to FIG. 2, differential 18 may include a differential carrier 24 , a pinion shaft 26 , and a differential gear set 28 .
Carrier 24 is provided to transfer torque from a power input shaft 30 to gear set 28 . Carrier 24 may be made from conventional metals and metal alloys. Carrier 24 is disposed about axis 12 and includes first 32 and second members 34 that may be coupled together using conventional fasteners (not shown). Members 32 , 34 are supported within the differential 18 and axle housings 22 on bearings 36 , 38 and rotate responsive to torque provided by input shaft 26 through a pinion gear 40 mounted to one end of shaft 26 and a ring gear 42 coupled to, or integral with member 32 . Members 32 , 34 together define a cavity 44 configured to receive gear set 28 . Members 32 , 34 further define corresponding recesses 46 , 48 configured to receive pinion shaft 26 . Finally, members 32 , 34 define openings 50 , 52 configured to receive axle half shafts 14 , 16 and from which axle half shafts 14 , 16 extend. Member 32 , 34 further includes an axially extending portion 54 having one or more splines 56 .
Pinion shaft 26 is provided to transfer torque from carrier 24 to gears 58 , 60 of gear set 28 . Shaft 26 is conventional in the art and may be made from conventional metals and metal alloys. Shaft 26 has a longitudinal axis 62 perpendicular to axis 12 and is received within recesses 46 , 48 of members 32 , 34 of carrier 24 . Gears 58 , 60 are mounted to shaft 26 proximate either end of shaft 26 .
Gear set 28 is provided to transfer torque to axle half shafts 14 , 16 and is convention in the art. Gears 58 , 60 are disposed about pinion shaft 26 while gears 64 , 66 are disposed about axle half shafts 14 , 16 , respectively. Rotation of gears 58 , 60 responsive to rotation of pinion shaft 26 and carrier 24 causes a corresponding rotation in gears 64 , 66 and axle half shafts 14 , 16 .
Brake assembly 20 is provided to brake rotation of axle half shafts 14 , 16 and, therefore, the wheels disposed on either axial end of drive axle assembly 10 . In accordance with the present invention, assembly 20 may include a brake housing 68 , a differential hub 70 , a first friction plate assembly 72 , a second friction plate assembly 74 , and a piston 76 . Assembly may also include an adapter hub 78 and a thrust bearing 80 .
Brake housing 68 is provided to support and enclose several components of brake assembly 20 and also provides a friction surface used in braking axle half shafts 14 , 16 . Housing 68 may be made from conventional metals and metal alloys known in the art. Housing 68 may include a first portion 82 and a second portion 84 . First portion 82 may extend generally radially outward from carrier 24 and may be supported thereon by bearings 36 . Second portion 84 may extend axially from first portion 82 and may include an axially extending bore 86 . Bore 86 may align with corresponding bores in axle housing 22 and differential housing 88 and may be sized to receive a fastener 90 such as a screw or bolt therethrough. Second portion 84 may also include one or more axially extending splines 92 on a radially inward side 94 for a purpose described hereinbelow.
Hub 70 is provided to support components of friction plate assembly 74 . Hub 70 also compresses friction plate assembly 72 upon actuation of brake assembly 20 and provides a friction surface against which friction plate assembly 72 acts. Hub 70 may be made from conventional metals and metal alloys. Hub 70 may be disposed about axis 12 and may have a generally radially extending portion 96 coupled to carrier 24 on spline(s) 56 such that hub 70 may be axially movable relative to carrier 24 and/or brake housing 20 . Hub 70 may include an axially extending portion 98 coupled to, or a integral with, portion 96 . Portion 98 may include one or more axially extending splines 100 for a purpose described hereinbelow.
First friction plate assembly 72 functions as a braking clutch. Assembly 72 is disposed on a first side 102 of differential hub 70 , between hub 70 and portion 82 of brake housing 68 and is axially movable relative to hub 70 and brake housing 68 . Assembly 72 may include one or more conventional friction plate members 104 and one or more corresponding conventional reaction plate members 106 . In the illustrated embodiment, assembly includes four friction plate members 104 and four reaction plate members 106 . It should be understood, however, that the number of members 104 , 106 may vary without departing from the spirit of the present invention. Friction plate members 104 may be coupled to carrier 24 through spline(s) 56 on carrier 24 while reaction plate members 106 may be coupled to brake housing 68 through spline(s) 92 on housing 68 .
Second friction plate assembly 74 functions as a differential clutch or locking device. Assembly 74 is disposed on a second side 108 of differential hub 70 and is axially movable relative to carrier 24 . Assembly 74 may also include one or more conventional friction plate members 110 and one or more corresponding conventional reaction plate members 112 . In the illustrated embodiment, assembly includes two friction plate members 110 and two reaction plate members 112 . It should again be understood, however, that the number of members 110 , 112 may vary without departing from the spirit of the present invention. Friction plate members 110 may be coupled to adapter hub 78 as described hereinbelow. Reaction plate members 112 may be coupled to portion 98 of differential hub 70 through spline(s) 100 .
Piston 76 is provided to selectively urge second friction plate assembly 74 , differential hub 70 , and first friction plate assembly 72 in an axial direction against first portion 82 of brake housing 68 . Piston 76 may be actuated by fluid pressure (e.g., hydraulic or pneumatic) in a known manner. Piston 76 may be disposed within axle housing 22 and may be configured to receive a dowel pin 114 extending from housing 22 by which piston 76 may be fixed against rotation. The size and shape of piston 76 may be varied relative to design considerations associated with axle housing 22 .
Adapter hub 78 is provided to support friction plate members 110 of friction plate assembly 74 . Hub 78 may be made from conventional metals and metal alloys. Hub 78 may be annular in construction and may be disposed about axis 12 and coupled to axle half shaft 14 through one or more splines (not shown). Hub 78 may itself include one or more splines 116 on which friction plate members 110 of assembly 74 may be supported for axial movement. Hub 78 may be adjacent to portion of 54 carrier 24 .
Thrust bearing 80 is provided to absorb axial thrust from piston 76 and is conventional in the art. Bearing 80 is disposed between piston 76 and assembly 74 .
Brake assembly 20 operates as follows. When piston 76 is actuated, piston 76 moves in a first axial direction (to the right in FIG. 1 ). Piston 76 (which may act through thrust bearing 80 ) compresses friction plate assembly 74 causing friction plate members 110 and reaction plate members 112 to move axially along splines 100 , 116 , respectively, and against the friction surface provided by differential hub 70 . Hub 70 also moves axially along spline(s) 56 and compresses friction plate assembly 72 causing friction plate members 104 and reaction plate members 106 to move axially along spline(s) 56 and against the friction surface provided by portion 82 of brake housing 68 . Braking torque is transferred to carrier 24 through portion 54 of carrier 24 thereby preventing rotation of carrier 24 which in turn prevents rotation of both axle half shafts 14 , 16 .
When a vehicle incorporating axle assembly 10 is on dry ground and stopping in a straight line, there is no relative rotation between carrier 24 and axle half shaft 14 , 16 . As a result, assemblies 72 , 74 are rotating in unison and the braking torque is generated by assembly 72 .
When a vehicle incorporating axle assembly 10 is on dry ground and stopping in a curved path, relative rotation occurs between friction plate members 110 and reaction plate members 112 of assembly 74 . This relative rotation generates a torque biasing action that provides a greater amount of braking torque to the inside wheel (relative to the turn).
When a vehicle incorporating axle assembly 10 stops in a straight line and there is very poor traction between the vehicle and ground (such as when one wheel is on concrete and the other wheel is on ice) and a maximum brake pressure is applied through piston 76 , friction plate assembly 72 immediately stops differential carrier 24 from rotating. Because the bias ratio of friction plate assembly 74 may be exceeded, the differential 18 and assembly 74 may begin to spin. In this event, assembly 74 will provide the braking torque with a majority of the torque provided to the wheel having superior traction (e.g., the wheel on concrete).
A brake assembly 20 in accordance with the present invention represents a significant improvement as compared to traditional brake assemblies for drive axles. Traditional brake assemblies have two brakes in the axle, one for each wheel. The use of multiple braking devices requires additional parts and materials and increases assembly time-all of which increase the cost of the drive axle assembly. The use of multiple braking devices also increases the size and weight of the drive axle assembly. The inventive brake assembly 20 is less expensive to manufacture because fewer materials are needed, yet maintains effective brake capacity and vehicle handling characteristics.
While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it is well understood by those skilled in the art that various changes and modification can be made in the invention without departing from the spirit and scope of the invention. | A brake assembly having a single brake capable of applying a braking torque to both axle half shafts in a drive axle is provided. The brake assembly includes a piston that selectively actuates both a differential locking clutch and a braking clutch each of which may comprise a friction plate assembly. The piston urges the differential locking clutch against a friction surface formed on a differential hub that is mounted on a differential carrier and is axially movable relative to the carrier. The braking clutch is then urged by movement of the differential hub against another braking surface formed on a stationary brake housing. The plates of the braking clutch are coupled to the differential carrier allowing a braking torque to be transmitted through the carrier to both axle half shafts using a single braking device. | 1 |
[0001] The present invention, which describes the use of a peptide secreted by a lactobacillus in human immunotherapy, relates both to the food technology sector and to medicine. It relates to the amino acid sequence (ST peptide) that could be used in immunotherapy of certain inflammatory diseases, such as inflammatory bowel disease (IBD; divided into Crohn's disease, ulcerative colitis and pouchitis) and in other pathologies where oral tolerance is compromised (as in the case of celiac disease with respect to dietary gluten). The route of administration could be inclusion in a functional foodstuff or via directed maturation of donor dendritic cells (vaccines of dendritic cells).
PRIOR ART
[0002] The human gastrointestinal tract is home to a wide variety of commensal, mutualist and pathogenic bacteria and is precisely where there is one of the main points of contact between bacteria and the immune system. This set of bacteria contributes to a large extent to the set of antigens or foreign substances together with the antigens in the diet against which, in normal conditions, the immune system would react with the aim of eliminating them, as occurs in systemic immunity. However, in the intestinal compartment this does not occur at all like this, and instead a mechanism of immunologic tolerance is deployed against said antigens, called oral tolerance, intended to maintain homeostasis of the mucosa (Feng and Elson (2010) Adaptive immunity in host—microbiota dialog. Muc. Immunol. 4, 15-21). In certain circumstances this homeostasis is lost and the immune system reacts abnormally against the intestinal microbiota, with development of more or less severe inflammatory processes such as inflammatory bowel disease (IBD) or against some antigens in the diet (as in the case of gluten in celiac disease). Moreover, the relation that exists between certain autoimmune diseases and deregulation in the composition of the intestinal microbiota is also known (Adams et al. (2008) IgG antibodies against common gut bacteria are more diagnostic for Crohn's Disease than IgG against mannan or flagellin. Am. J. Gastroenterol. 103, 386-396).
[0003] The process of tolerance to the intestinal microbiota is mediated, in large part, by two cellular types which, incorporated in the intestinal mucosa, are responsible for the correct processing and recognition of the antigens originating from the intestinal microbiota. These are the T lymphocytes and the dendritic cells (DCs). The DCs are phagocytic cells specialized in the processing and presentation of antigens; in the case of the intestinal DCs they play an essential role in recognition of the microorganisms that are present there, putting out pseudopodia between the enterocytes of the intestinal epithelium toward the lumen (Rescigno et al. (2001) Dendritic cells express tight junction proteins and penetrate gut epithelial monolayers to sample bacteria. Nat Immunol. 2, 361-367). The DCs engulf the bacterial particles and process them, undergoing a series of changes called maturation and displaying these bacterial antigens on their surface, so that they can be recognized by other cells of the immune system. This change, moreover, is accompanied by a series of phenotypic alterations in the DCs, such as the production of certain cytokines. The DCs are, in their turn, crucial for the proliferation and differentiation of the T lymphocytes into effector cells of type Th1 (induce a pro-inflammatory response), Th2 (induce an anti-inflammatory response) or Th17 (are involved in the protection of surface tissues against infections), or else into regulatory cells (Treg) (Zhu and Pau (2008) CD4 T cells: fates, functions, and faults. Blood 112, 1557-1569). Complementing the DCs, the T lymphocytes are the cells responsible for the cellular immune response.
[0004] Some strains belonging to the lactic acid group of bacteria are considered to be probiotic, since they are capable of modulating the composition of the intestinal microbiota favorably, with beneficial effects on human health (Rijkers, G. T. et al. (2010) Guidance for substantiating the evidence for beneficial effects of probiotics: current status and recommendations for future research. J. Nutr. 140, 671S-676S). In recent years, various research teams have been accumulating scientific evidence that suggests that certain extracellular components might be responsible for some of the beneficial effects attributed to probiotics. This makes more sense if it is borne in mind that in normal conditions, in healthy individuals, the microbiota is not in direct contact with the layer of enterocytes and/or the DCs. In fact, the microbiota is embedded in the protective layer of mucus that covers the epithelial layer of the intestine. It is therefore plausible that these beneficial effects of probiotics are not due to direct interaction of the bacteria with the DCs. Conversely, the probiotics might perform their function by producing certain components that can cross the layer of mucus, facilitating capture of them by the DCs. Among these extracellular components, we may mention exopolysaccharides, teichoic acids, indoles and the surface and extracellular proteins (Lebeer et al. (2010) Host interactions of probiotic bacterial surface molecules: comparison with commensals and pathogens. Nat. Rev. Microbiol. 8, 171-84). The latter are defined as the group of proteins that are secreted during bacterial growth and that are released to the medium surrounding them (Sánchez et al. (2008) Exported proteins in probiotic bacteria: adhesion to intestinal surfaces, host immunomodulation and molecular cross-talking with the host. FEMS Immunol. Med. Microbiol. 54, 1-17). At present, the extracellular proteins constitute an active area of research for identification and characterization of the molecular mechanisms of action of probiotics.
[0005] The extracellular proteins can be divided into two main groups. The first comprises those proteins that have a signal peptide that is located in their N-terminal portion and guides the pre-protein to the secretion machinery, via which it is secreted to the medium. The second group comprises those proteins which, in addition to a signal peptide, have cell surface binding domains, and are released to the medium during the process of renewal of the bacterial wall. Finally, some authors identify a third group of extracellular proteins, comprising proteins of the central metabolism, without secretion domains, and for which the mechanism responsible for their secretion to the extracellular environment is unknown.
[0006] The systems for secreting proteins are highly conserved within the Eubacteria division. These systems are particularly well characterized in Gram-negative bacteria, where at least seven systems are identified (types 1-6 and the system of “twin arginines”) (Sibbald and van Dijl (2009) Bacterial secreted proteins: secretory mechanisms and role in pathogenesis. Ed. Wooldridge, Caister Academic Press). In Gram-positive bacteria, the taxonomic group that comprises the majority of probiotic strains, the extracellular proteins would be exported by similar systems.
[0007] Until now, bioinformatics has been the tool used for identifying extracellular proteins in probiotics, and only a small proportion have been well identified or characterized experimentally. Among the extracellular proteins produced by the bifidobacteria, we may mention the serine protease inhibitor (serpin), produced by various species of bifidobacteria (Turroni et al. (2010) Characterization of the serpin-encoding gene of Bifidobacterium breve 210B. Appl. Environ. Microbiol. 76, 3206-3219). This protein efficiently inhibits both the elastases secreted by the exocrine pancreas and by the neutrophils, immune cells implicated in inflammatory processes. For this reason it has been postulated that serpin might be responsible for some of the anti-inflammatory effects of the bifidobacteria. It has also been suggested that proteins secreted by a strain of Bifidobacterium breve could be capable of producing soluble factors, very probably small peptides, which after interacting with the DCs would reduce the inflammatory processes at the level of the intestinal epithelium (Heuvelin et al. (2009) Mechanisms involved in alleviation of intestinal inflammation by Bifidobacterium breve soluble factors. PLoS ONE. 4:e5184).
[0008] These works are just examples of how the process of intercellular communication between bacteria and immune cells of the innate system could mediate a series of physiological responses directed at regulating the immunologic homeostasis of our intestinal mucosa, and therefore of our body. Part of this process, as shown by the results described in the present invention, could be mediated by peptides encoded within the main proteins secreted by the lactic acid bacteria present in our gastrointestinal tract.
[0009] Regarding similar patents available in the databases, we may mention patent EP95900421.9 that relates to protection of some compositions that bind specifically to colorectal cancer cells and the method of use thereof. This document describes the use of other ST peptides, in this case derivatives of a heat-stable toxin produced by a strain of the bacterium Escherichia coli , whose sequences do not correspond to the sequence of the peptide described in this invention. Although this document defines the “ST peptides” as the ST receptor binding peptides of between 13 and 25 amino acids, these peptides originate from E. coli and are included in conjugated compounds, which also comprise a radiostable active residue, and are capable of being directed specifically at metastasized colorectal cancer cells.
[0010] On the other hand, WO2009138092 refers to strain 299v of Lactobacillus plantarum and stresses the probiotic properties of the strain Lb. plantarum DSM 21379, describing the use thereof in the development of a functional foodstuff and of a medicinal product for improving cellular immunity. The functions of this microorganism that are emphasized include that of inducing the production of cytokines for improving the animal's immune system. Although this document describes how Lb. plantarum produces cytokines for improving the immune system, said cytokines are pro-inflammatory (IL-6).
[0011] Therefore there is currently a need to identify an ST peptide derived from proteins secreted by lactic acid bacteria, with both immunomodulating and anti-inflammatory function for treating diseases connected with deregulation of the intestinal microbiota, inflammatory diseases and/or diseases where oral tolerance is compromised.
BRIEF DESCRIPTION OF THE INVENTION
[0012] This invention describes the sequence of the ST peptide, encoded within one of the proteins secreted by a lactic acid bacterium, preferably Lactobacillus plantarum (so far without known function), said peptide of 30 kDa contains a fragment without cleavage sites for the most important intestinal proteases. It is also characterized by having a serine and threonine content of at least 50%. If this peptide is brought in contact with DCs obtained both from blood and from human intestinal biopsies, it is able to modulate them to a regulatory phenotype where the production of IL-12 (pro-inflammatory interleukin characteristic of antigen presenting cells) is blocked and the production of IL-10 (anti-inflammatory cytokine via blocking of the synthesis of pro-inflammatory cytokines by other immune cell types, such as the T lymphocytes) is expanded. These DCs treated with the ST peptide also acquire a different functionality since the T lymphocytes that they stimulate acquire a migratory profile directed preferentially at the skin with a profile of non-pro-inflammatory cytokines. This mechanism of action contributes actively to maintaining intestinal homeostasis not by priming the mechanisms of immunologic tolerance but instead of immunologic ignorance. Thus, the mature DCs with the ST peptide in the intestine promote secondary migration of the effector cells (T lymphocytes) to the skin, thereby hindering the establishment of an active immune response against the commensal flora in the gastrointestinal tract.
[0013] To summarize, the ST peptide promotes the mechanisms of intestinal homeostasis via its action on the DCs. Since it is capable of blocking an anti-inflammatory interleukin (IL-12) and of increasing the synthesis of an anti-inflammatory interleukin (IL-10), the ST peptide could be used in immunotherapy, in the context of certain inflammatory and autoimmune diseases, in which it is known that there is an abnormal immune response to the intestinal microbiota as well as in other pathologies where the mechanisms of oral tolerance to other antigens are lost. This would provide the scientific basis for the creation of a whole range of functional foodstuffs that would contain those molecules, produced by the probiotics, that are responsible for their beneficial action on human health.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The present invention relates to an ST peptide with immunomodulating and/or anti-inflammatory properties, characterized in that:
[0015] a) it is secreted by a bacterium of the genus Lactobacillus,
[0016] b) its amino acid sequence has a content of between 30 and 60% of the amino acids serine and threonine, and
[0017] c) it comprises a fragment of at least 30 kDa without cleavage sites for at least one intestinal protease.
[0018] In the present invention, the term “ST peptide” refers to a peptide preferably of 73 amino acids, with immunomodulating and/or anti-inflammatory properties, that is secreted preferably by a Lactobacillus bacterium , preferably by Lactobacillus plantarum , more preferably by the strains Lb. plantarum NCIMB 8826, Lb. plantarum 299V, and Lb. plantarum BMCM12, whose amino acid sequence has a content of at least 50% of the amino acids serine and threonine, and comprises a fragment of at least 30 kDa without cleavage sites for at least one intestinal protease. This peptide can have at least 80-100% homology with SEQ ID No: 1, or the ortholog thereof.
[0019] In the present invention, the expression “with immunomodulating properties” refers to its capacity for modulating the response of cells of the human immune system such as the dendritic cells, which in their turn are capable of modulating the function of other immune cells such as the T lymphocytes. This modulation of the immune response comprises blocking.
[0020] In the present invention, the expression “with anti-inflammatory properties” refers to its capacity for inducing the production of interleukin 10, a potent anti-inflammatory cytokine, as well as for blocking the production of interleukin 12, a cytokine of a pro-inflammatory nature, in dendritic cells isolated both from peripheral blood and from human intestinal mucosa. Moreover, T lymphocytes matured in the presence of said dendritic cells will also acquire a profile of production of non-pro-inflammatory cytokines.
[0021] In a preferred embodiment said Lactobacillus bacterium is Lactobacillus plantarum . More preferably, the strain of said bacterium Lactobacillus plantarum is selected from the following group of strains: Lb. plantarum NCIMB 8826, Lb. plantarum 299V, and Lb. plantarum BMCM12.
[0022] In a preferred embodiment of the present invention, said ST peptide is characterized in that its amino acid sequence has at least 80-100% homology with SEQ ID No: 1. Preferably said ST peptide is characterized in that its amino acid sequence has 95% homology with SEQ ID No: 1. More preferably said ST peptide is characterized in that its amino acid sequence is SEQ ID No: 1, or the ortholog thereof.
[0023] In the present invention the term “homology” refers to the concept of “sequence homology”, referring to the degree of similarity between two amino acid or nucleotide sequences.
[0024] In the present invention the term “ortholog” refers to two amino acid or nucleotide chains, derived from two different organisms, that share a high degree of homology.
[0025] In a preferred embodiment of the present invention, said ST peptide is characterized in that the intestinal protease is selected from the following group: pepsin, trypsin, chymotrypsin, and combinations thereof.
[0026] The present invention also refers to the use of said ST peptide in a method for treating and/or preventing an intestinal disorder, said method being characterized in that it comprises administering a therapeutically effective amount of the ST peptide defined above to a patient, to activate the process of immunologic ignorance or tolerance to the commensal bacteria of the intestine of said patient.
[0027] In the present invention the term “intestinal disorder” refers to any intestinal ailment where the immune system is involved either in its origin or in its treatment.
[0028] In the present invention the term “immunologic tolerance” refers to the set of induced processes whereby the immune system does not respond to an antigen, endogenous or exogenous.
[0029] In the present invention, the term “immunologic ignorance” refers to its capacity for promoting the mechanisms of intestinal homeostasis promoting not only immunologic tolerance (differentiating the dendritic cells isolated both from peripheral blood and from human intestinal mucosa toward a cytokine regulatory profile) but also priming the T lymphocytes that are stimulated with an increased capacity for migration toward skin tissues where they will not be exposed to the microbial antigens of the gastrointestinal tract.
[0030] In the present invention the expression “commensal bacteria of the patient's intestine” refers to the set of bacteria that live in the human gastrointestinal tract.
[0031] In a preferred embodiment of the present invention said intestinal disorder is an inflammatory disease, selected between an inflammatory bowel disease (IBD), or a celiac disease.
[0032] In an even more preferred embodiment of the present invention said inflammatory bowel disease (IBD) is selected from the following group: Crohn's disease, ulcerative colitis and pouchitis.
[0033] In a preferred embodiment of the present invention said intestinal disorder is caused by an autoimmune disease or a disease caused by deregulation in the composition and/or activity/metabolism of the intestinal microbiota.
[0034] In a preferred embodiment of the present invention said immunomodulating and/or anti-inflammatory properties are manifested respectively in that the administration of a therapeutically effective amount of the ST peptide to a patient comprises:
[0035] a) inducing, in the dendritic cells of said patient, the production of an anti-inflammatory and homeostatic cytokine, preferably interleukin 10 (IL-10), and/or
[0036] b) blocking, in the dendritic cells of said patient, the production of a pro-inflammatory cytokine, preferably pro-inflammatory interleukin 12 (IL-12), when this is present, in addition to other pro-inflammatory cytokines such as IL-6 that are highly relevant in inflammatory bowel disease.
[0037] In an even more preferred embodiment, the method of treatment and/or prevention defined above is characterized in that said dendritic cells in their turn induce the maturation of T lymphocytes, which:
[0038] a) acquire a profile of migration to the skin, and/or
[0039] b) acquire a profile of production of non-pro-inflammatory cytokines.
[0040] Preferably the profile of migration to the skin defined in a) comprises a decrease in expression of the marker of migration to intestinal mucosa integrin β7 and an increase in expression of the marker of migration to skin CLA. Preferably the profile of production of non-pro-inflammatory cytokines defined in b) comprises a decrease in the expression of pro-inflammatory cytokines IFNγ and interleukin 17 (IL-17).
[0041] In another preferred embodiment of the present invention, said administration of a therapeutically effective amount of the ST peptide is characterized in that said ST peptide is contained in a functional foodstuff (probiotic) or else in a pharmaceutical composition, preferably in the form of a capsule.
[0042] Another aspect protected by the present invention relates to a functional foodstuff, characterized in that it comprises a therapeutically effective amount of the ST peptide defined above.
[0043] In the present invention the term “functional foodstuff” refers to the set of foodstuffs which, in addition to their nutritional characteristics, confer a benefit on the consumer's health or help to avoid contracting diseases.
[0044] Another aspect protected by the present invention relates to a composition, preferably pharmaceutical, characterized in that it comprises a therapeutically effective amount of the ST peptide defined above.
[0045] In the present invention the term “pharmaceutical composition” refers to a mixture of active principles and excipients with a format suitable for use in humans.
[0046] The present invention also relates to the use of the functional foodstuff or composition defined above, to activate the process of immunologic tolerance toward the commensal bacteria of the patient's intestine.
[0047] The present invention also relates to the use of said ST peptide in a cosmetic application.
[0048] In the present invention the term “cosmetic application” refers to the use in cosmetics intended to improve the state of human skin, notably of the face.
[0049] Throughout the description and the claims, the word “comprises” and its variants are not intended to exclude other technical characteristics, additives, components or steps. For a person skilled in the art, other aims, advantages and features of the invention will become clear partly from the description and partly from the implementation of the invention. The following figures and examples are provided for purposes of illustration, and are not intended to limit the present invention.
DESCRIPTION OF THE FIGURES
[0050] FIG. 1 . Protein gel in denaturing conditions showing the total proteins and proteins secreted by 3 strains of Lactobacillus plantarum . Lanes 1-3: total proteins of strains NCIMB 8826, 299v and BMCM12. Lane 4: proteins present in the culture medium. Lanes 5-7: proteins secreted by strains NCIMB 8826, 299v and BMCM12. MM: marker of molecular weight of proteins (kDa).
[0051] FIG. 2 . A. Zone rich in serines and threonines present in the central zone of protein D1 identified as SEQ ID NO: 2, between amino acid positions 70 and 135, and B. Amino acid sequence of the ST peptide identified as SEQ ID NO: 1, described in the present patent. The amino acids underlined in SEQ ID NO: 1 represent the changes of the ST peptide relative to the central zone of protein D1 identified as SEQ ID NO: 2.
[0052] FIG. 3 . Theoretical cleavage sites of the main intestinal proteases on the central fragment of protein D1, identified as SEQ ID NO: 2. As can be seen (indicated with an arrow), the fragment ST does not contain theoretical cleavage sites. A. Represents the fragment of protein D1 between amino acid positions 61 and 120, identified as SEQ ID NO: 3, and B. represents the fragment of protein D1 between amino acid positions 121 and 180, identified as SEQ ID NO: 4.
[0053] FIG. 4 . Migration of the ST peptide identified as SEQ ID NO: 1 purified in polyacrylamide gel in denaturing conditions.
[0054] FIG. 5 . a) Production of markers of migration to intestinal mucosa (integrin β7) and to skin (CLA) in enriched dendritic cells from human blood (LDCs). The conditions tested were the baseline (absence of signaling), 0.0, 0.1, 1.0 or 10 micrograms/milliliter of the ST peptide identified as SEQ ID NO: 1. b) the test carried out with this peptide alters neither the markers of migration to tissues (β7 and CLA), nor the molecules of the MHC of type II (HLA-DR) nor certain co-stimulatory molecules (CD40) or activating molecules (CD83) on enriched dendritic cells from human blood. Stimulation with lipopolysaccharide (LPS) was used as a control of stimulation with a pro-inflammatory bacterial component.
[0055] FIG. 6 . Modification of the profile of production of cytokines measured in the cytoplasm of enriched dendritic cells from human blood induced by different concentrations of the ST peptide identified as SEQ ID NO: 1. Stimulation with LPS was used as a control of stimulation with a pro-inflammatory bacterial component. IL-6: interleukin 6, TGFβ: transforming growth factor beta, IL-10: interleukin 10, IL-12: interleukin 12.
[0056] FIG. 7 . Modification of the profile of production of the cytokines IL-10 and IL-12 measured in the cytoplasm of enriched dendritic cells from colon mucosa biopsies (intestinal DC).
[0057] FIG. 8 . From left to right, representations obtained by flow cytometry that represents populations of T cells stimulated with allogenic dendritic cells. Left panel: detection of viable cells by the “forward side scatter” technique. Central panel: identification of the marker DC3. Right panel: the stimulated T cells were identified by loss of the staining for CFSE derived from cell division.
[0058] FIG. 9 . Flow cytometry diagrams showing changes induced in T cells stimulated by enriched dendritic cells from blood (LDC) and exposed to the ST peptide identified as SEQ ID NO: 1 (LDC BP) or to lipopolysaccharide (LPS LDC). In all cases comparison was with the changes produced in the T cells at rest (resting T-cells), and using unstimulated LDCs (basal LDC). A) Changes in the levels of the marker of migration to intestinal mucosa integrin β7 induced by different concentrations of the ST peptide identified as SEQ ID NO: 1 (BP LDC) and of lipopolysaccharide (LPS LDC). B) Changes in the levels of the marker of migration to skin CLA induced by different concentrations of the ST peptide identified as SEQ ID NO: 1 (BP LDC) and of lipopolysaccharide (LPS LDC). C) Bar chart representation of the results of 3 independent experiments.
[0059] FIG. 10 . Flow cytometry diagrams showing changes in the production of the cytokines IL-10, TGFβ, IFNγ and IL-17 in T lymphocytes stimulated by enriched dendritic cells from blood (LDC) and pulsed with different concentrations of the ST peptide identified as SEQ ID NO: 1 (BP LDC) or lipopolysaccharide (LPS LDC). In all cases comparison was with the changes produced in the T cells at rest (resting T-cells), and using unstimulated LDCs (basal LDC).
[0060] FIG. 11 . Graphical representation of the data in FIG. 10 showing the values of 3 independent experiments and their deviations.
[0061] FIG. 12 . Flow cytometry diagrams showing changes in the production of the cytokines TGFβ, IL-10, IL-17 and IFNγ in T lymphocytes stimulated by enriched dendritic cells from colon biopsies (gut DC) in the absence of stimulation (basal gut DC) (central panel) or pulsed beforehand with the ST peptide identified as SEQ ID NO: 1 (peptide gut DC) (bottom panel). The top panel shows the production of the same cytokines in T cells at rest (resting T cells).
[0062] FIG. 13 . Flow cytometry diagrams showing changes in the production of the markers of migration β7 (intestinal mucosa) and CLA (epithelial mucosa) in T lymphocytes stimulated with enriched dendritic cells from colon biopsies (gut DC) in the absence of stimulation (basal gut DC) (central panel) or pulsed beforehand with the ST peptide identified as SEQ ID NO: 1 (peptide gut DC) (bottom panel). The top panel shows the production of the same markers of migration in T cells at rest (resting T cells).
[0063] FIG. 14 . Flow cytometry diagrams representing the production of IL-10 and IL-12 in a donor whose dendritic cells of the colon mucosa displayed abnormal production of IL-12. These dendritic cells were incubated in the presence of the ST peptide identified as SEQ ID NO: 1 (+BP). In comparison with the baseline conditions (basal) the presence of the ST peptide identified as SEQ ID NO: 1 was capable of inducing the production of IL-10 and of blocking the production of IL-12.
BIBLIOGRAPHY
[0064] Adams et al. (2008) IgG antibodies against common gut bacteria are more diagnostic for Crohn's Disease than IgG against mannan or flagellin. Am. J. Gastroenterol. 103, 386-396
[0065] Feng and Elson (2010) Adaptive immunity in the host—microbiota dialog. Muc. Immunol. 4, 15-21
[0066] Lebeer et al. (2010) Host interactions of probiotic bacterial surface molecules: comparison with commensals and pathogens. Nat. Rev. Microbiol. 8, 171-84
[0067] Rescigno et al. (2001) Dendritic cells express tight junction proteins and penetrate gut epithelial monolayers to sample bacteria. Nat Immunol. 2, 361-367
[0068] Rijkers, G. T. et al. (2010) Guidance for substantiating the evidence for beneficial effects of probiotics: current status and recommendations for future research. J. Nutr. 140, 671S-676S
[0069] Sánchez et al. (2008) Exported proteins in probiotic bacteria: adhesion to intestinal 25 surfaces, host immunomodulation and molecular cross-talking with the host. FEMS Immunol. Med. Microbiol. 54, 1-17
[0070] Sibbald and van Dijl (2009) Bacterial secreted proteins: secretory mechanisms and role in pathogenesis. Ed. Wooldridge, Caister Academic Press
[0071] Turroni et al. (2010) Characterization of serpin-encoding gene of Bifidobacterium breve 210B. Appl. Environ. Microbiol. 76, 3206-3219
[0072] Zhu and Pau (2008) CD4 T cells: fates, functions, and faults. Blood 112, 1557-1569
EXAMPLES
[0073] The following specific examples that are provided in this patent document serve to illustrate the nature of the present invention. These examples are included solely for purposes of illustration and are not to be interpreted as limitations to the invention claimed herein. Therefore the examples described hereunder illustrate the invention without limiting the field of application thereof.
Identification of the Proteins Secreted by Lb. plantarum and of the ST Peptide Identified as SEQ ID NO: 1
[0074] Lb. plantarum is a mesophilic lactic acid bacterium that can be isolated from a large number of fermented foodstuffs, including vegetable and milk products (Tallon et al. (2003) Isolation and characterization of two exopolysaccharides produced by Lactobacillus plantarum EP56. Res. Microbiol. 154, 705-712). The capacity of some strains for surviving the conditions of the human gastrointestinal tract has meant that some researchers have been interested in its probiotic potential. Thus, the beneficial effects of some strains of Lb. plantarum on human health, currently marketed as probiotics (as is the case of strain 299v), have been demonstrated scientifically (de Vries, et al. (2006) Lactobacillus plantarum —survival, functional and potential probiotic properties in the human intestinal tract. Int. Dairy J. 16, 1018-1028).
[0075] At present, there is growing interest in investigating the proteins secreted by probiotic bacteria, as they are potential mediators of intercellular communication between bacteria and cells of the host's immune system. As can be seen in FIG. 1 , which shows the main proteins secreted by Lb. plantarum NCIMB 8826, Lb. plantarum 299v and Lb. plantarum BMCM12 (lanes 5, 6 and 7), there is relative similarity between the proteins secreted by different members of the species Lb. plantarum . The sequence of the ST peptide, whose sequence is shown in FIG. 2 identified as SEQ ID No: 1, is derived from the central zone of the protein designated D1 (GenBank identifying number gi|28270057) identified as SEQ ID No: 2, with some modifications and inclusions of amino acids that are shown underlined in SEQ ID NO: 1 ( FIG. 2 ). This zone is characterized by its richness in the amino acids serine and threonine, from which its name is derived, and is characterized by the absence of cleavage sites for some of the most important proteases of the gastrointestinal tract (pepsin, trypsin and chymotrypsin) ( FIG. 3 ).
[0076] Cloning and Purification of the ST Peptide Identified as SEQ ID NO: 1 (Verification of the Absence of Lipopolysaccharide)
[0077] The DNA sequence coding for the fragment ST (corresponding to the amino acid sequence marked in FIG. 2 as SEQ ID NO: 2), was cloned in Lactococcus lactis and was purified in a nickel affinity column according to standard protocols. This peptide is secreted to the culture supernatant, from where it can be isolated and purified, and is characterized by forming artifacts in agarose gels in denaturing conditions (SDS-PAGE), migrating to a size corresponding to about 100 kDa ( FIG. 4 ). The sequence of the terminal amino of the peptide was verified by Edman degradation.
[0078] Regions rich in serine and threonine can be found in proteins encoded by many other lactic acid bacteria and in genera of the gastrointestinal tract, so that the conclusions derived from the present invention could be applied to ST peptides derived from other sequences of other microorganisms.
Interaction of the ST Peptide Identified as SEQ ID NO: 1 with Dendritic Cells
[0079] Since the ST peptides released by the intestinal proteases or by the proteases of the antigen presenting cells may be capable of influencing the function of the innate immune system associated with mucosae, we undertook an investigation of their interaction with the principal antigen presenting cells, the DCs. Firstly, absence of lipopolysaccharide in the samples of ST peptide identified as SEQ ID NO: 1 was verified using the chromogenic kit from Genscript. Our starting hypothesis was to consider that the ST peptide identified as SEQ ID NO: 1, produced in the intestinal environment or ingested with foodstuffs, might interact with the DCs of the intestinal mucosa, thus affecting the immune function.
Example 1
Interaction of the ST Peptide Identified as SEQ ID NO: 1 with Dendritic Cells Derived from Blood
[0080] 1.1. Material and Methods
[0081] The dendritic cells were obtained from healthy patients who had neither autoimmune diseases, nor inflammatory diseases nor allergies nor malignant tumors. These subjects had given their written consent for their blood to be used for scientific purposes. The peripheral blood mononuclear cells (PBMCs) were isolated by differential centrifugation in Ficoll-Paque Plus (Amersham Biosciences, Chalfont St. Giles, UK). The cellular fraction LDC (low-density cells) was obtained by overnight centrifugation in NycoPrepe™ solution. The cells present in this LDC fraction were HLA-DR positive in 98-100% of cases, with morphological characteristics typical of the DCs (Ng, et al. (2009). A novel population of human CD56+ human leukocyte antigen D-related (HLA-DR+) colonic lamina propria cells is associated with inflammation in ulcerative colitis. Clin. Exp. Immuno 1.158, 205-218).
[0082] Half a million LDCs per milliliter were cultured in complete medium (Dutch modified RPMI 1640 (Sigma-Aldrich, Dorset, UK) containing 100 U/mL penicillin/streptomycin, 2 mM L-glutamine, 50 U/mL gentamicin (Sigma-Aldrich) and fetal bovine serum at 10% (v/v) (TCS cellworks, Buckingham, UK)). These cultures were carried out in the presence of the ST peptide identified as SEQ ID NO: 1 purified at concentrations of 10 μg/mL, 1 μg/mL and 0.1 μg/mL, and of LPS (100 ng/mL) (Sigma-Aldrich, St. Louis, USA) as positive control. The results were compared with parallel cultures without ST peptide identified as SEQ ID NO: 1 nor added LPS, acting as negative controls.
[0083] For the various experiments, labeling of the cells with the various antibodies (Table 1) was carried out in PBS supplemented with 1 mM EDTA and sodium azide at 0.02% (w/v) (FACS buffer). Labeling was carried out for 20 minutes in ice, in the dark. The cells were then washed with FACS buffer and were fixed with paraformaldehyde at 1% (v/v) in saline solution, and stored at 4° C. until acquisition of data in the flow cytometer. The negative controls used were isotype-matched antibodies without specificity, labeled with the same fluorochrome, which were obtained from the same company (isotype controls).
[0084] The flow cytometry data were obtained in a FACSCalibur cytometer (BD Biosciences), and the data were analyzed with the WinList 5.0 software (Verity, Me., US). The proportion of samples positive for a particular marker was determined relative to isotype controls. For quantification by histograms, an analysis was performed with the WinList software, in which the histogram of isotype staining was subtracted from the histogram of specific staining using normalized superenhanced D max (SED) substraction (Bagwell, C. B. (2005). Hyperlog—a flexible log-like transform for negative, zero, and positive valued data. Cytometry. 64, 34-42).
Intracellular Staining of Cytokines
[0085] The DCs were cultured for 4 hours in the presence/absence of monensin. Then they were stained for the surface markers as described above. Next they were fixed with LeucopermA, and permeabilized with LeucopermB before adding the intracellular staining antibodies. After incubation, the DCs were washed in FACS buffer, were fixed and were acquired as described above. The analysis was performed by the SED substraction detailed above, where the histogram of each cytokine of the DCs that had not been incubated with monensin were subtracted from the histogram of each cytokine of the DCs that had been incubated in the absence of monensin. This protocol has been extensively validated by our colleagues (Hart et al., (2005) Characteristics of intestinal dendritic cells in inflammatory bowel diseases. Gastroenterology. 129, 50-65) and makes it possible to quantify changes in the natural production of cytokines by the DCs in the absence of external stimuli such as PMA and/or ionomycin. Using this approach, the intracellular content of each cytokine is not determined. Instead, the changes induced in the production of cytokines in a temporal window of 4 hours (incubation time with monensin) are determined independently of the initial content of cytokines.
[0086] 1.2. Results
[0087] As can be seen in FIG. 5 (panel A), the ST peptide identified as SEQ ID NO: 1 did not produce changes in the markers of migration of the DCs enriched with peripheral blood (integrin β7, intestinal mucosa marker and CLA, skin marker). Nor did the peptide produce changes in the induction of MHC molecules of type II (HLA-DR) or of certain co-stimulating molecules (CD40) or activation molecules (CD83) ( FIG. 5 , panel B). As can be seen in the latter, LPS (positive control) did induce overexpression in all of them.
[0088] Regarding the changes in the production of (intracellular) cytokines induced by the peptide in LDCs, this did not affect the regulatory molecule TGFβ, implicated in the control of cell growth, in cellular proliferation, and in processes of differentiation and apoptosis. Conversely, the ST peptide identified as SEQ ID NO: 1 induced a reduction in the synthesis of IL-6 (inducer of the generation of Th17 cells) and IL-12 (pro-inflammatory), and an increase in the synthesis of IL-10 (anti-inflammatory and homeostatic) ( FIG. 6 ).
[0089] In conclusion, the presence of the ST peptide identified as SEQ ID NO: 1 in enriched dendritic cells from human blood (LDCs) means that these acquire a profile of production of regulatory cytokines, reducing the production of the pro-inflammatory cytokine IL-12 and increasing the production of the anti-inflammatory cytokine IL-10. The reduction in the synthesis of IL-6, with consequent theoretical reduction in the synthesis of type Th17 T cells, is also interesting since in the context of certain autoimmune and inflammatory diseases an increase of this cell type is observed (Stockinger and Veldhoen (2007) Differentiation and function of Th17 T cells. Curr. Opin. Immunol. 19, 281-286).
Example 2
Interaction of the ST Peptide Identified as SEQ ID NO: 1 with Dendritic Cells Obtained from Biopsy of Intestinal Mucosa
[0090] Since the site of action of the ST peptide identified as SEQ ID NO: 1 would in principle be the intestinal mucosa, we decided to try to validate the experiments described in example 1 using DCs isolated from said location.
[0091] 2.1. Material and Methods
[0092] Biopsies from the colon were obtained from three healthy patients, who had given their written consent to participate in this study (one woman and two men, age range 30-58 years). These patients had normal intestines, both macroscopically and histologically, and had been examined after reporting changes in intestinal transit or rectal bleeding. Once obtained, the biopsies were collected in complete medium cooled to 4° C. and were processed before the first hour counting from when they were obtained. The biopsies were incubated in Hanks's balanced salt solution (HBSS) (Gibco BRL, Paisley, Scotland, UK) containing 1 mM dithiothreitol (DTT) (Sigma-Aldrich) for 20 minutes. Next, they were incubated in a 1 mM solution of ethylenediaminetetraacetic acid (EDTA) in order to remove both the epithelial cells and the layer of mucus and its associated bacteria. The mononuclear cells of the lamina propria were extracted by digestion in the presence of collagenase D 1 mg/mL (Roche Diagnostics Ltd, Lewes, UK) in complete medium, which does not affect the phenotype or the function of the DCs (Hart et al. (2005) Characteristics of intestinal dendritic cells in inflammatory bowel diseases. Gastroenterology, 129, 50-65). The cellular suspensions of mononuclear cells of the lamina propria (200000 cells/mL) were incubated for 4 hours in the presence of the ST peptide identified as SEQ ID NO: 1 purified (10 μg/mL) and in the presence/absence, in its turn, of monensin, with their corresponding negative controls. The DCs of the lamina propria were identified by flow cytometry from the presence of the markers HLA-DR+ and CD3-CD14-CD16-CD19-CD34- (Hart et al. (2005) Characteristics of intestinal dendritic cells in inflammatory bowel diseases. Gastroenterology, 129, 50-65).
[0093] The remaining procedures followed in this example were the same as in section 1 of example 1.
[0094] 2.2. Results
[0095] Using the model of intestinal DCs, the two most interesting points described in example 1 could be confirmed, the increase in the production of IL-10 and the absence of any increase in the production of IL-12. At this point it has to be borne in mind that the DCs isolated from the intestinal mucosa of healthy individuals have very low levels of production of the pro-inflammatory cytokine IL-12 ( FIG. 7 ).
Example 3
Interaction of Dendritic Cells Obtained from Blood Matured with the ST Peptide Identified as SEQ ID NO: 1 with T Lymphocytes
[0096] 3.1. Material and Methods
[0097] The T lymphocytes were obtained from peripheral blood mononuclear cells (PBMCs). The PBMCs, obtained from freshly drawn blood as described in example 1, were resuspended in MiniMACs buffer (PBS supplemented with bovine serum albumin 0.5% (w/v) and EDTA 2 mM). This suspension was enriched with T cells by removing the CD14 positive, CD19 positive and HLA-DR positive cells with immuno-magnetized beads (Miltenyi Biotech, Bisley, UK) following the manufacturer's instructions. A percentage of T cells of 94.91%±1.06 (mean±standard deviation) was obtained as the mean value of all the extractions/enrichments.
[0098] The T cells were labeled with 5-carboxyfluorescein diacetate succinimidyl ester (CFSE, Invitrogen Ltd, UK) according to the manufacturer's instructions. The T cells thus labeled (4×10 5 cells per well) were incubated for 5 days with DCs at 0, 1, 2 or 3% in microtiter plates with U-shaped bottom. The proliferating T cells were identified and quantified by flow cytometry as those that contained a small amount of CFSE (CFSE low ) ( FIG. 8 ).
[0099] The remaining flow cytometry protocols were carried out as described in section 1 of example 1.
[0100] 3.2. Results
[0101] The fraction of T cells that were not put in contact with DCs (resting T cells) displayed a profile of “homing” (markers that indicate to which tissue they are directed) and of production of interleukins (IL-10, TGFβ, IFNγ, IL-17) characteristic of each donor. As was to be expected, both the absolute values of “homing” markers, and those of production of cytokines produced by LDCs (example 1) not conditioned with the ST peptide identified as SEQ ID NO: 1 or with LPS, were also different in each donor.
[0102] Despite this, the DCs incubated beforehand with the ST peptide identified as SEQ ID NO: 1 or with LPS (positive control), always induced the same profile of production of cytokines and of “homing” markers in the T cells from the various donors. Focusing on the DCs incubated with the ST peptide identified as SEQ ID NO: 1, these induced, in the T lymphocytes, a decrease in the marker of migration to intestinal mucosa integrin β7, whereas, conversely, the amount of marker CLA (marker of migration to skin) increased considerably ( FIG. 9 ). Therefore, the DCs enriched with blood incubated in the presence of the ST peptide identified as SEQ ID NO: 1 imprint markers of migration to skin in the T lymphocytes. From the immunologic viewpoint, this can be interpreted as a mechanism of immune ignorance of the antigens present in the gastrointestinal tract. In this sense, the T cells, once in the skin, would never encounter the antigen against which they were selected in the intestinal mucosa, and are therefore inactive.
[0103] Moreover, the profile of production of cytokines in these same T cells (co-incubated with DCs that had previously been incubated with the ST peptide identified as SEQ ID NO: 1) differed in the sense that both the production of IFNy and of IL-17 decreased ( FIGS. 10 and 11 ). Both cytokines are pro-inflammatory, and in the case of IL-17 (Th17 cells) it is known that its production by the T cells is greater in certain autoimmune and inflammatory diseases.
[0104] Therefore the T lymphocytes matured with DCs conditioned by the ST peptide identified as SEQ ID NO: 1 acquire a profile of production of non-pro-inflammatory cytokines and a profile of migration to skin.
Example 4
Interaction of Dendritic Cells Obtained from Intestinal Mucosa Matured with the ST Peptide Identified as SEQ ID NO: 1 with Virgin T Lymphocytes
[0105] This example is the same as the preceding example, except in this case DCs isolated from intestinal mucosa were used. As can be seen in FIG. 12 , the intestinal DCs are already “homeostatic” in the sense that the profile of cytokines that they imprint on the T cells is to induce IL-10 (anti-inflammatory), whereas there is no increase in other interleukins (TGFβ, IL-17 and IFNγ). The DCs incubated with the ST peptide identified as SEQ ID NO: 1 induce an even greater increase in the production of IL-10 and in the production of TGFβ in the T cells ( FIG. 12 c ).
[0106] Finally, just as in the preceding example, the DCs conditioned by the peptide induce a greater number of lymphocytes that express the marker of migration to skin (FIG. 13 ) so that, once more, it is demonstrated that the ST peptide identified as SEQ ID NO: 1 would promote the process of immune ignorance.
Example 5
Potential Use of the ST Peptide Identified as SEQ ID NO: 1 in Inflammatory Bowel Disease, Autoimmune Diseases with Cutaneous Manifestations and Cosmetics
[0107] One of the donors who gave written consent to donate a biopsy from the intestinal mucosa of the colon for our experiments had some DCs that produced unusually high levels of IL-12, the classical pro-inflammatory interleukin of the antigen presenting cells. As can be seen in FIG. 14 , the ST peptide identified as SEQ ID NO: 1 completely cancelled the production of IL-12 in these dendritic cells, as well as increasing the production of the anti-inflammatory interleukin IL-10.
[0108] Although it is a single example, we suggest that the ST peptide identified as SEQ ID NO: 1 defined above could be included in programs of immunotherapy in the context both of inflammatory bowel disease and other inflammatory diseases, and in the context of autoimmune diseases that proceed with inflammatory symptoms. | Among the fewer than 10 proteins primarily secreted by the species Lactobacillus plantarum , there is one of 30 kDa that contains an internal fragment without cleavage sites for the most important intestinal proteases and characterized by having a serine and threonine content of at least 50%. The genetic information encoded in this fragment, designated ST peptide, has been used for producing and purifying said peptide, thus making it possible to conduct various tests in vitro.
To summarize, the ST peptide is considered to promote the process of immunologic ignorance of our gastrointestinal immune system toward the commensal bacteria of our gastrointestinal tract, thus favoring the mechanisms of oral tolerance. Therefore the ST peptide could be used in immunotherapy, especially in the context of certain autoimmune diseases and certain inflammatory diseases. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
The present application is a continuation of pending U.S. application Ser. No. 08/287,154 filed on Aug. 8, 1994, which is a continuation of 08/199,652, filed on Feb. 22, 1994, now U.S. Pat. No. 5,367,047, which was a divisional of 08/007,376 filed on Jan. 21, 1993, now U.S. Pat. No. 5,288,783; which was a continuation-in-part of 07/882,919 filed on May 14, 1992, now abandoned.
FIELD OF THE INVENTION
This invention relates to a process for the production of polyaspartic acid and its salts and the use of these materials.
DESCRIPTION OF RELATED ART
The salts of polyaspartic acid have been used for fertilizers, and scale inhibition agents. They are particularly useful for the prevention of scale deposition in boiler water, reverse osmosis membranes and in detergents. One of the primary characteristics that makes them valuable in this respect is the fact that they are readily biodegradable, whereas other materials that are presently used for this purpose are either slowly biodegradable, e.g. polyacrylic acid, or harmful to the environment, e.g. polyphosphoric acid.
Sodium polyaspartate was used in the prevention of boiler scale by changing the crystal structure of calcium salts resulting in the formation of a soft scale (Sarig et al, The use of polymers for retardation of scale formation. Natl Counc Res Dev Rep! (Isr.), 150, 1977). Polyaspartic acid, molecular weight (MW) 6,000, was found to be superior to polyglutamate, MW 14,400, polyvinyl sulfonate, MW 5300, and polyacrylic acid, MW 6,000, in that it gave 66% retardation of total scale and 90% retardation of calcium sulfate scale. In addition, the scale formed in the presence of polyaspartate was softer than that produced in the presence of polyacrylate, polyglutamate and polyvinyl sulfonate.
U.S. Pat. No. 4,839,461 discloses a method for making polyaspartic acid from maleic acid and ammonia by reacting these constituents in a 1:1-1.5 molar ratio by raising the temperature to 120°-150° C. over a period of 4-6 hours and maintaining it for 0-2 hours. It is further disclosed that temperatures above 140°-160° C. result in elimination of CO 2 , thus teaching degradation of the material. The molecular weight range obtained by this method was said to be 1,000-4,000 with a cluster at 1,800-2,000. That patent states that this material is useful in the prevention of tarnishing glass and porcelain articles. Although not stated in this patent, it is known that this action would occur as a result of the inhibition of calcium sulfate deposition. Harada, et al (Thermal polycondensation of free amino acids with polyphosphoric acid. Origins Prebiol. systems Their Mol Matrices, Proc. Conf., Wakulla Springs, Fla., 289, 1963) obtained polyaspartic acid from aspartic acid and phosphoric acid at temperatures over 100° C. over a time period of 50-250 hrs, but required temperatures over 170° without phosphoric acid being present.
U.S. Pat. No. 5,057,597 discloses a method for the polycondensation of aspartic acid to produce polyaspartic acid by heating the aspartic acid in a fluidized bed reactor to 221° C. for a period of 3-6 hours in a nitrogen atmosphere followed by conventional alkaline hydrolysis.
Kovacs et al. (J. Org. Chem., 25 1084 1961!) prepared polyaspartic acid by heating aspartic acid to 200° C. in vacuo for a period of 120 hours or in boiling tetralin over a period of 100 hours. Kovacs et al, showed that the intermediate formed in the thermal polymerization of aspartic acid was polysuccinimide.
Frankel et al. (J. Org. Chem., 16, 1513 1951!) prepared polyaspartic acid by heating the benzyl ester of N-carboxyanhydroaspartic acid followed by saponification.
Dessaigne (Comp. rend. 31, 432-434 1850!) prepared condensation products which gave aspartic acid on treatment with nitric or hydrochloric acid by dry distillation of the acid ammonium salts of malic fumaric or maleic acid at unspecified times and temperatures.
SUMMARY OF THE INVENTION
Polymers of aspartic acid which are suitable for the prevention of scale may be obtained by reacting maleic acid and ammonia in a molar ratio of 1:1-2.1 at 200°-300° C. and then converting the polysuccinimide formed to a salt of polyaspartic acid by hydrolysis with a metal hydroxide. The reaction is carried out by the addition of water to maleic anhydride, thus forming maleic acid, or to maleic acid followed by addition of the appropriate amount of ammonia in the form of gaseous ammonia or as its aqueous solution. This solution is then heated to remove water. A melt of the maleic acid and ammonia is formed and water removal continues as the reaction proceeds and the temperature is brought to 200°-300° C. When the theoretical quantity of water formed in the production of polysuccinimide has been removed, which may occur in less than 5 minutes, the reaction mixture is allowed to cool. The polysuccinimide formed can be used to make other useful products or can be hydrolyzed with metal hydroxides to provide the appropriate salt of polyaspartic acid. Solutions of the salts of polyaspartic acid formed in this manner have the same scale inhibition performance and molecular weight range as do the polymers formed by the thermal polymerization of aspartic acid itself. Further manipulation to remove the water or the salts can be carried out to provide water free powders of the salts or the free acid.
The polyaspartic acid provided by the present invention is suitable for inhibition of scale deposition, whereas the methods previously used to produce polyaspartic acid did not provide a polymer of sufficient molecular weight to prevent scale formation.
The object of this invention is to provide a means of preparing polysuccinimide. A further object of this invention is to provide a means of preparing salts of polyaspartic acid.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the effect of additives on the inhibition of calcium carbonate precipitation.
FIG. 2 shows the effect of thermally polymerized mono-ammonium maleate salts as calcium scale inhibitors.
FIG. 3 shows the effect of thermally polymerized mono-ammonium fumarate salts as calcium scale inhibitors.
FIG. 4 shows the effect of thermally polymerized di-ammonium fumarate and maleate salts as calcium scale inhibitors.
FIG. 5 shows the calibration of a molecular weight column.
FIG. 6 shows the molecular weight determination of polymers formed in Examples 2, 4, 10, and 11.
FIG. 7 shows the molecular weight determination of polymers formed in Examples 6, 8, 12, and 13.
FIG. 8 shows the molecular weight determination of polymers formed in Examples 3 and 7
DETAILED DESCRIPTION OF THE EMBODIMENTS
As opposed to the teachings of U.S. Pat. No. 4,839,461, I have found that, although the use of the polyaspartic made by the process is said to be useful in the prevention of hardness deposits, no actual experimentation to confirm this finding is reported. In fact, upon careful repetition of the procedures of U.S. Pat. No. 4,839,461, the results below clearly demonstrate that polymers of aspartic acid prepared by heating the ammonium salts of maleic acid at 140°-150° C. for 4 to 6 hours did not give a polymer that was active as a calcium scale inhibitor. Further, when calculations of the theoretical weight of polysuccinimide (molecular weight 97) formed in Example 1 indicates that the reaction was not taken to completion under the conditions described.
EXAMPLE 1
Thermal Polymerization of L-Aspartic Acid at 240°-250° C.
Aspartic acid, 133 g, was tumbled under nitrogen at 100 Torr, at 240°-250° C. for 1.5 hours to give a pink powder weighing 97.3 g. This solid was slurried in 200 ml of water at 25° C. and a solution of 40 g of water containing 40.0 g of sodium hydroxide was added over a period of 15 minutes with intermittant cooling to keep the temperature between 60° and 70° C. The resultant clear red-brown solution, pH 12.0, was adjusted to pH 7.0 by the addition of 1.5 g of citric acid and contained 25% solids.
The sodium polyaspartate was tested for inhibition of calcium carbonate precipitation by the calcium drift assay. In this assay a supersaturated solution of calcium carbonate is formed by adding 29.1 ml of 0.55M NaCl and 0.01M KCl to 0.15 ml of 1.0M CaCl 2 and 0.3 ml of 0.5M NaHCO 3 . The reaction is initiated by adjusting the pH to 7.5-8.0 by titration with 1N NaOH and addition of the material to be tested for inhibition of CaCO 3 precipitation at a level of 1.7 ppm. At three minutes, 10 mg of CaCO 3 is added and the pH is recorded. The decrease in pH is directly correlated to the amount of CaCO 3 that precipitates. The effectiveness of the inhibition is compared to that of sodium polyacrylate, used commercially for the purpose of preventing scale formation.
FIG. 1 shows the effect of no additive in this test compared with polyacrylate, chemically synthesized L-α-polyaspartate and the polyaspartate prepared in this Example. Both thermally prepared and chemically synthesized polyaspartate were very close to polyacrylate by the calcium drift assay when all materials were tested at 1.7 ppm of additive.
EXAMPLE 2
Thermal Polymerization of Mono-Ammonium Maleate at 145°-150° C.
Following the examples of U.S. Pat. No. 4,839,461, a slurry of 9.8 g (0.1 mole) maleic anhydride was dissolved in 20 ml water at 80°-95° C. and stirred for 30 minutes while allowing the mixture to cool to 25° C. To this colorless solution at 25° C. was added 13 g of 30% aqueous solution of ammonium hydroxide (0.11 mol NH 3 ) to give a colorless solution. This solution was boiled to dryness over a period of 30 minutes at approximately 100°-115° C. to give a white crystalline solid. The solid was tumbled under nitrogen at 100 Torr, at 145°-150° C. for 4 hours to give a water insoluble, pinkish-tan brittle glasslike solid weighing 11.4 g. This solid was dissolved in 26.2 g of an aqueous solution containing 1.36 g of sodium hydroxide to form a clear red-brown solution, pH 7.0, containing 25% solids.
FIG. 2 shows a plot of the data obtained in this example compared to that of the no additive assay and the thermally prepared polyaspartate. The material obtained at 145°-150° C. is no better than no additve when tested at 1.7 ppm.
EXAMPLE 3
Thermal Polymerization of Mono-Ammonium Maleate at 190°-200° C.
A slurry of 9.8 g (0.1 mole) maleic anhydride was dissolved in 20 ml water at 80°-95° C. and stirred for 30 minutes while allowing the mixture to cool to 25° C. To this colorless solution at 25° C. was added 13 g of 30% aqueous solution of ammonium hydroxide (0.11 mol NH 3 ) to give a colorless solution. This solution was boiled to dryness over a period of 30 minutes at approximately 100°-115°-C. to give a white crystalline solid. The solid was tumbled under nitrogen at 100 Torr, at 190°-200° C. for 4 hours to give a water insoluble, pinkish-tan brittle glasslike solid weighing 10.6 g. This solid was dissolved in 35.4 g of an aqueous solution containing 1.9 g of sodium hydroxide to form a clear red-brown solution, pH 9.0, containing 25% solids.
FIG. 2 shows that polyaspartic acid of this example in the calcium drift assay of Example 1 at 1.7 ppm much improved compared to the material of Example 2.
EXAMPLE 4
Thermal Polymerization of Mono-Ammonium Maleate at 240°-250° C.
A slurry of 9.8 g (0.1 mole) maleic anhydride was dissolved in 20 ml water at 80°-95° C. and stirred for 30 minutes while allowing the mixture to cool to 25° C. To this colorless solution at 25° C. was added 13 g of 30% aqueous solution of ammonium hydroxide (0.11 mol NH 3 ) to give a colorless solution. This solution was boiled to dryness over a period of 30 minutes at approximately 100°-115° C. to give a white crystalline solid. The solid was tumbled under nitrogen at 100 Torr, at 240°-250° C. for 1.5 hours to give a water insoluble, pinkish-tan brittle glasslike solid weighing 9.6 g. This solid was dissolved in 36.0 g of an aqueous solution containing 4.0 g of sodium hydroxide to form a clear red-brown solution, pH 12.0. To this solution was added 0.25 g citric acid to adjust the pH to 8.5 and the resultant solution contained 25% solids.
FIG. 2 shows that the polyaspartic acid of this example in the calcium drift assay of Example 1 at 1.7 ppm was equivalent to that of thermally prepared polyaspartate.
EXAMPLE 5
Thermal Polymerization of Mono-Ammonium Maleate at 300° C.
A slurry of 9.8 g (0.1 mole) maleic anhydride was dissolved in 20 ml water at 80°-95° C. and stirred for 30 minutes while allowing the mixture to cool to 25° C. To this colorless solution at 25° C. was added 13 g of 30% aqueous solution of ammonium hydroxide (0.11 mol NH 3 ) to give a colorless solution. This solution was boiled to dryness over a period of 30 minutes at approximately 100°-115° C. to give a white crystalline solid. The solid was tumbled at 300° C. for 5 minutes to give a water insoluble, brick-red brittle glasslike solid weighing 9.6 g. This solid was dissolved in 40.0 g of an aqueous solution containing 3.8 g of sodium hydroxide to form a clear red-brown solution, pH 9.0, containing 25% solids.
FIG. 2 shows that the polyaspartic acid of this example in the calcium drift assay of Example 1 at 1.7 ppm was equivalent to that of thermally prepared polyaspartate.
In summary, polyaspartic acid prepared at 145°-150° C. from maleic anhydride and ammonia was ineffective as a scale inhibitor while that prepared at 190°-200° C. was nearly as effective as thermal polyaspartate and that prepared at 240° or 300° C. was equivalent to thermal polyaspartic as a scale inhibitor. The time required for polymerization was reduced from 4-8 hours to between 5 minutes and 1.5 hours, thus providing a significant improvement in the economy of industrial production.
EXAMPLE 6
Thermal Polymerization of Mono-Ammonium Fumarate at 145°-150° C.
Following the examples of U.S. Pat. No. 4,839,461, a slurry of 11.6 g (0.1 mole) fumaric acid was dissolved in 30 ml water was mixed with 13 g of 30% aqueous solution of ammonium hydroxide (0.11 mol NH 3 ). Carefully warming the slurry to boiling gave a clear solution. This solution was boiled to dryness over a period of 15 minutes to give a white crystalline solid. The solid was tumbled under nitrogen at 100 Torr, at 145°-150° C. for 8 hours to give an off-white glasslike solid weighing 13.2 g. This solid was dissolved in 40 g of an aqueous solution containing 4.0 g of sodium hydroxide to form a pale yellow solution, pH 8.5, containing 25% solids.
FIG. 3 shows a plot of the data obtained in the calcium drift assay on the material obtained in this example. The material was only slightly better than no additve when tested at 1.7 ppm.
EXAMPLE 7
Thermal Polymerization of Mono-Ammonium Fumarate at 190°-200° C.
A slurry of 11.6 g (0.1 mole) fumaric acid was dissolved in 30 ml water was mixed with 13 g of 30% aqueous solution of ammonium hydroxide (0.11 mol NH 3 ). Carefully warming the slurry to boiling gave a clear solution. This solution was boiled to dryness over a period of 15 minutes to give a white crystalline solid. The solid was tumbled under nitrogen at 100 Torr, at 190°-200° C. for 4 hours to give a water insoluble, tan glasslike solid weighing 12.0 g. This solid was dissolved in 40 g of an aqueous solution containing 4.0 g of sodium hydroxide to form a pale yellow solution, pH 7.0, containing 25% solids.
FIG. 3 shows a plot of the data obtained in the calcium drift assay on the material obtained in this example. The material was only slightly better than no additive when tested at 1.7 ppm.
EXAMPLE 8
Thermal Polymerization of Mono-Ammonium Fumarate at 240°-250° C.
A slurry of 11.6 g (0.1 mole) fumaric acid was dissolved in 30 ml water was mixed with 13 g of 30% aqueous solution of ammonium hydroxide (0.11 mol NH 3 ). Carefully warming the slurry to boiling gave a clear solution. This solution was boiled to dryness over a period of 15 minutes to give a white crystalline solid. The solid was tumbled under nitrogen at 100 Torr, at 240°-250° C. for 1.5 hours to give a water insoluble, dark brown glasslike solid weighing 9.3 g. This solid was dissolved in 40 g of an aqueous solution containing 4.0 g of sodium hydroxide to form a clear brown solution, pH 8.0, containing 25% solids.
FIG. 3 shows a plot of the data obtained in the calcium drift assay on the material obtained in this example. The material was much better than that prepared in Example 6 when tested at 1.7 ppm.
EXAMPLE 9
Thermal Polymerization of Mono-Ammonium Fumarate at 300° C.
A slurry of 11.6 g (0.1 mole) fumaric acid was dissolved in 30 ml water was mixed with 13 g of 30% aqueous solution of ammonium hydroxide (0.11 mol NH 3 ). Carefully warming the slurry to boiling gave a clear solution. This solution was boiled to dryness over a period of 15 minutes to give a white crystalline solid. The solid was tumbled at 300° C. for 5 minutes to give a water insoluble, dark brown glasslike solid weighing 9.8 g. This solid was dissolved in 40 g of an aqueous solution containing 3.8 g of sodium hydroxide to form a clear brown solution, pH 9.0, containing 25% solids.
FIG. 3 shows a plot of the data obtained in the calcium drift assay on the material obtained in this example. The material was much better than that prepared in Example 6 when tested at 1.7 ppm.
In summary, thermally polymerized mono-ammonium fumarate provided polyaspartate prepared at 145°-150° C. and at 190°-200° C. which was only slightly active in scale inhibition while that prepared at 240° C. and at 300° C. were active but less active than thermal polyaspartate as scale inhibitors.
EXAMPLE 10
Thermal Polymerization of Di-Ammonium Maleate at 135°-140° C.
Following the examples of U.S. Pat. No. 4,839,461, a solution of 1.96 g (0.02 mole) maleic anhydride was dissolved in 1 ml water at 50°-60° C. and stirred for 30 minutes while allowing the mixture to cool to 25° C. To this colorless solution at 2° C. was added 2.4 g of 30% aqueous solution of ammonium hydroxide (0.022 mol NH 3 ) to give a colorless solution. This solution was boiled to dryness over a period of 30 minutes at approximately 100°-120° C. and 10-20 Torr, to give a white crystalline solid. The solid was tumbled under nitrogen at 100 Torr, at 135°-140° C. for 8 hours to give a water insoluble, pinkish-tan brittle glasslike solid weighing 2.7 g. This solid was dissolved in 6.6 g of an aqueous solution containing 0.8 g of sodium hydroxide to form a clear orange solution, pH 7.0, containing 25% solids.
FIG. 4 shows a plot of the data obtained in this example compared to that of the no additive assay and the thermally prepared polyaspartate. The material obtained at 135°-145° C. is not as good as no additive when tested at 1.7 ppm.
EXAMPLE 11
Thermal Polymerization of Di-Ammonium Maleate at 240°-250° C.
A solution of 9.8 g (0.1 mole) maleic anhydride was dissolved in 20 ml water at 50°-60° C. and stirred for 30 minutes while allowing the mixture to cool to 25° C. To this colorless solution at 25° C. was added 26 g of 30% aqueous solution of ammonium hydroxide (0.22 mol NH 3 ) to give a colorless solution. This solution was boiled to dryness over a period of 30 minutes at approximately 100°-120° C. and 10-20 Torr, to give a white crystalline solid. The solid was tumbled under nitrogen at 100 Torr, at 240°-250° C. for 1.5 hours to give a water insoluble, red-brown brittle glasslike solid weighing 9.4 g. This solid was dissolved in 40 g of an aqueous solution containing 3.8 g of sodium hydroxide to form a clear red-brown solution, pH 7.0, containing 25% solids.
FIG. 4 shows a plot of the data obtained in this example compared to that of the no additive assay and the thermally prepared polyaspartate. The material of this example is equivalent to that of thermal polyaspartate when tested at 1.7 ppm.
EXAMPLE 12
Thermal Polymerization of Di-Ammonium Fumarate at 140°-150° C.
A slurry of 11.6 g (0.1 mole) fumaric acid was dissolved in 30 ml water was mixed with 26 g of 30% aqueous solution of ammonium hydroxide (0.22 mol NH 3 ). Carefully warming the slurry to boiling gave a clear solution. This solution was boiled to dryness over a period of 15 minutes to give a white crystalline solid. The solid was tumbled under nitrogen at 100 Torr, at 140°-150° C. for 8 hours to give a water insoluble, brown, glasslike solid weighing 14 g. This solid was dissolved in 100 g of an aqueous solution containing 2.0 g of sodium hydroxide to form a pale yellow solution, pH 7.0, containing 25% solids.
FIG. 4 shows a plot of the data obtained in the calcium drift assay on the material obtained in this example. The material was only slightly better than no additve when tested at 1.7 ppm.
EXAMPLE 13
Thermal Polymerization of Di-Ammonium Fumarate at 235°-245° C.
A slurry of 11.6 g (0.1 mole) fumaric acid was dissolved in 30 ml water was mixed with 26 g of 30% aqueous solution of ammonium hydroxide (0.22 mol NH 3 ). Carefully warming the slurry to boiling gave a clear solution. This solution was boiled to dryness over a period of 15 minutes to give a white crystalline solid. The solid was tumbled under nitrogen at 100 Torr, at 235°-245° C. for 1.5 hours to give a water insoluble, brown, glasslike solid weighing 9.0 g. This solid was dissolved in 100 g of an aqueous solution containing 2.0 g of sodium hydroxide to form a pale yellow solution, pH 8.5, containing 25% solids.
FIG. 4 shows a plot of the data obtained in the calcium drift assay on the material obtained in this example. The material was only slightly better than no additve when tested at 1.7 ppm.
EXAMPLE 14
Molecular Weight Analysis of Polyaspartate Prepared in Various Ways
Molecular weight determination of the materials prepared in the foregoing examples and commercially available materials was made by chromatography on a 1 cm×18 cm, Sephadex G-50 column in a mobile phase of 0.02M sodium phosphate buffer, pH 7.0, running at 0.5 ml/min, with detection in the UV at 240 nm. The sample size ranged from 0.01 to 0.5 mg/ml.
FIG. 5 shows the results of sodium polyaspartate, 13,000 m.w., from Sigma, I; sodium polyaspartate, 7,500 m.w., from Sigma, II; and sodium polyaspartate, Example 1, II. m.w. 5,000, from Sigma.
FIG. 6 shows the result of Example 4 as "a"; Example 11 as "b"; Example 2 as "c" and Example 10 as "d". With maleic acid and ammonia reactions, temperatures of 240° C. gave molecular weights over a broad range centered at 7,000-8,000 while temperatures of 135°-150° C. gave molecular weights over a broad range centered at 2,000.
FIG. 7 shows the result of Example 8 as "e"; Example 13 as "f"; Example 6 as "g" and Example 12 as "h". With fumaric acid and ammonia reactions, temperatures of 240° C. gave molecular weights over a broad range centered at 7,000-8,000 while temperatures of 140°-150° C. gave molecular weights over a broad range centered at 2,000.
FIG. 8 shows the result of Example 3 as "i"; Example 7 as "j". Temperatures of 190°-200° C. gave molecular weights for maleate over a broad range centered at 7,000-8,000 while temperatures of 190°-200° C. for fumarate gave molecular weights over a broad range centered at 2,000. | Polyaspartate, useful for inhibition of incrustations due to materials causing hardness in water and of value in detergent formulations, can be prepared by reacting maleic acid or fumaric acid in a molar ratio of 1:1-2.1 at temperatures greater than 190° C., followed by conversion of the polymer formed in this reaction to a salt of polyaspartic acid by basic hydrolysis. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The subject matter of this application is related to copending concurrently filed U.S. application Ser. No. 233,721 entitled "Stiff Flexible Connector For A Circuit Breaker Or Other Electric Apparatus".
BACKGROUND OF THE INVENTION
1. Field of the Invention
The subject matter of this invention relates generally to electrical interconnection apparatus and more particularly to apparatus for interconnecting a circular stem with a relatively flat electrical conductor.
2. Description of the Prior Art
Circuit breaker apparatus in general and vacuum circuit interrupter apparatus in particular is useful for controlling and protecting electrical systems, apparatus and networks. Circuit breaker apparatus and in particular vacuum circuit interrupter apparatus include separable main contacts disposed within an insulating housing. Generally one of the contacts is fixed relative to both the housing and to an external electrical conductor which is interconnected with the circuit to be controlled by the circuit interrupter. On the other hand, the other separable main contact is movable. In the case of vacuum circuit interrupter apparatus the movable contact assembly usually comprises a stem of circular cross section having the contact at one end thereof enclosed within the vacuum chamber and a driving mechanism at the other end thereof external to the vacuum chamber. A flexible gas-tight bellows separates the vacuum chamber from the external region. The bellow expands and contracts with the movement of the stem so as to allow stem movement while at the same time retaining the integrity of the vacuum. It has been found that the circular shape of the stem is desirable for interconnection with the bellows among other things. Often the electrical interconnection between the aforementioned external apparatus or circuit to be protected by the circuit interrupter and the movable contact is made on the circular stem. It can be seen therefore that a need arises for channeling significant amounts of electrical current from a movable stem to a stationary electrical terminal or contact. One of the most popular ways to accomplish this in the prior art is to utilize a flexible conductor such as braided copper wire or the like. Examples of this may be found in U.S. Pat. No. 3,941,959 entitled "Vacuum Switching Apparatus With A Drive Unit And Ground Potential" issued Mar. 2, 1976 to Kohler et al. Another example can be found in U.S. Pat. No. 4,091,251 entitled "Vacuum Switch" issued May 23, 1978 to Amsler. Another way of tapping electrical current off a movable stem is with the aid of a sliding contact such as is described in U.S. Pat. No. 4,025,886 entitled "Electrical Circuit Breaker With Electro-Magnetically-Assisted Closing Means" issued May 24, 1977 to Barkan et al. All of the aforementioned have certain problems relative to known electrical and mechanical properties of conductors. Of particular importance are the electrical characteristic of contact resistance, the mechanical characteristic of flexibility and the general characteristics of construction cost and simplicity and then interrelationship. For example, with respect to the electrical characteristic of contact resistance it has been found that when a single electrical conductor is fastened to another electrical conductor, electrical contact is made in only three relatively small regions between the two conductors. This is regardless of the size of the common surface area of the conductors. This means that a relatively large conductor with a relatively large surface area interconnected with another relatively large conductor and bolted in many places thereto would still only make effective electrical contact at three regions in the contiguous surface therebetween. If on the other hand, one of the conductors was divided into a number of independent small conductors having the same effective surface area and were bolted independently to the other conductor, each of the small conductors would now have three of its own regions of contact although the total contact resistance may not increase. However, in a case such as that the complexity and cost of the construction process would increase because now multiple conductors would have to be interconnected with one conductor rather than a single conductor being interconnected with a single conductor. It would be advantageous therefore if a contact arrangement between a stem of a vacuum circuit interrupter for example and a fixed electrical terminal could be made with multiple independent contact surfaces. Some problems associated with multiple three point contact areas is exemplified in previously referred to U.S. Pat. No. 3,941,959 where a single massive interconnecting block is attached to a movable stem. The size, weight, and current carrying capabilities of the block seems to be great. However, it is to be remembered that only one three point contact arrangement is made. It would be advantageous therefore to provide apparatus for removing current from a movable circular stem to a fixed terminal by way of a conductor where multiple three point electrical contact regions are established where the manufacturing process for installation is relatively simple.
SUMMARY OF THE INVENTION
In accordance with the invention an electrical system is taught comprising electrical apparatus which includes an axial stem where the stem is generally circular in cross-section. A conductor is connected to the stem. The conductor has a generally flat inner portion with a central circular opening therein. The central opening has a smaller radius than the radius of the cross-section of the stem. The periphery of the central opening has a radial slit therein that allows the formation of the peripheral tab which is offset from the plane of the flat planar surface when the opening is initially disposed around the stem to thus initially accommodate for the difference in radii. Compression apparatus is disposed on the stem in a disposition of axial compression for causing the aforementioned tab to substantially realign with the plane of the planar portion after compression. The material of the tab thus assuming a flowed state in the region of the interface between the tab and the stem after compression to accommodate in the difference in radii. Multiple conductors are provided for reduced contact resistance relative to a given surface area and current capability of each conductor.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the invention, reference may be made to the accompanying drawings and to the preferred embodiments thereof exemplary of the invention shown in the accompanying drawings in which:
FIG. 1 shows an orthogonal front and side view of a metal enclosed circuit breaker system utilizing vacuum circuit interrupters and employing the teachings of the present invention;
FIG. 2 shows a side orthogonal view of the apparatus of FIG. 1;
FIG. 3 shows a side elevation of the drawout circuit interrupter of FIGS. 1 and 2;
FIG. 4 shows a front elevation of the drawout circuit interrupter of FIG. 3;
FIG. 5 shows a more detailed view of the circuit interrupter apparatus of FIGS. 2 and 3 in side elevation and partially in section;
FIG. 6 shows detailed view of the bell crank apparatus for the circuit interrupter of FIG. 5;
FIG. 7 shows a top view of a single flat flexible conductor for utilization with the present invention;
FIG. 8 shows a side view of the flexible conductor of FIG. 7;
FIG. 9 shows a side elevation of a top compression part for the stem mounting apparatus utilized with the circuit interrupter of FIG. 5;
FIG. 10 shows a top view of the apparatus of FIG. 9;
FIG. 11 shows a spacer for utilization in the apparatus of FIG. 5;
FIG. 12 shows the top view of apparatus of FIG. 11;
FIG. 13 shows another spacer for the utilization in the apparatus of FIG. 5;
FIG. 14 shows a top view of the apparatus of FIG. 13;
FIG. 15 shows an end spacer for the apparatus of FIG. 5;
FIG. 16 shows a top view of apparatus of FIG. 15;
FIG. 17 shows a side view of the end plate bell crank connector for the apparatus of FIG. 5;
FIG. 18 shows a top view of the apparatus of FIG. 17;
FIG. 19 shows a front elevation of the apparatus of FIG. 17;
FIG. 20 shows a more detailed view of the stem region of the apparatus of FIG. 5 with emphasis on the cooperation of the elements shown in FIGS. 7 through 19;
FIG. 21 shows a bottom view of the apparatus of FIG. 20;
FIG. 22 shows a view similar to that shown in FIG. 20 but for the second embodiment of the invention;
FIG. 23 shows a bottom view of the apparatus of FIG. 22;
FIG. 24 shows a flexible conductor similar to that shown in FIG. 7 but for a third embodiment of the invention; and
FIG. 25 shows side elevation of circuit breaker apparatus utilizing the flexible conductor of FIG. 24.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and FIGS. 1 and 2 in particular there is shown an embodiment of the invention for metal clad or metal enclosed switchgear. In particular, there is shown a switchgear station 10 which includes a metal cabinet or enclosure 12 which may have tandemly and vertically disposed therein drawout three-phase vacuum circuit interrupter apparatus 14 and 16. The front panel 15 of the circuit apparatus may have controls thereupon for manually operating the circuit interrupter apparatus. The lower circuit interrupter apparatus 14 as shown in FIGS. 1 and 2 is movably disposed by way of wheels 17 on rails 18 for moving the circuit breaker apparatus 14 into and out of a disposition of electrical contact with live terminals (not shown) disposed in the rear of the cabinet 12. Likewise the upper circuit interrupter apparatus 16 is movably disposed by way of wheels 19 on rails 20 for moving the upper circuit interrupter apparatus into and out of a disposition of electrical contact with terminals (not shown) in the rear of metal cabinet 12. Movable shutters such as shown at 21 may be interposed between the terminals 34 and 36, for example, of either of the three-phase drawout circuit interrupters 14 and 16 for shielding the cabinet high-voltage terminals from inadvertent contact therewith when the three-phase circuit interrupters 14 and 16 have been withdrawn to the position shown in FIG. 1. Barriers 21 are mechanically moved from in front of the aforementioned terminals when the three-phase circuit interrupters 14 and 16 are moved into a disposition of electrical contact with the aforementioned high-voltage terminals.
As is best shown in FIG. 2 the three-phase circuit interrupter apparatus 14, for example, may include a front portion 24 in which controls and portions of an operating mechanism are disposed and a rear portion 26. The front portion 24 is generally a low-voltage portion and the rear portion 26 is generally a high-voltage portion. The high-voltage portion 26 is supported by and electrically insulated from the low-voltage portion 24 by way of upper and lower insulators 28 and 30, respectively. Disposed within the high-voltage or rear portion 26 are vacuum circuit interrupter bottles 32 which provide circuit interrupting capability between the three-phase terminals 34 and 36, for example. The motion and information for opening and closing the contacts of the vacuum circuit interrupter bottles 32 may be supplied by way of linkage 38 from the front portion 24 to the rear portion 26.
Referring now to FIGS. 3 and 4, a simplified side elevation and front elevation, respectively, of the drawout circuit interrupter apparatus 14 of FIGS. 1 and 2 are shown. The linkage 38 is disposed between the low-voltage portion 24 and the high-voltage portion 26 for the purpose of conducting force which may originate in the low-voltage portion 24 to the high-voltage portion 26 for opening or closing the contacts of the vacuum circuit interrupter 32. A more detailed description of the construction and operation of the mechanism 38 is described hereinafter with respect to FIG. 6. Of particular importance with respect to the preferred embodiment of the present invention is the apparatus for interconnecting the movable stem (not shown) of the circuit interrupter apparatus 32 with the high-voltage contact 36 by way of a stiff, yet flexible, electrical conductor assembly 78.
Referring now to FIG. 5, FIG. 20 and FIG. 21, a circuit interrupter vacuum bottle 32 as well as the stiffened flexible conductor assembly 78 and an attachment device 76 are shown in detail. In particular there is provided an electrically insulated support member housing 42 having rearwardly (i.e. to the right in the figures) extending abutments 44 and 46 with vertically oriented threaded internal holes therein for accepting complementary bolt members. The lateral arrangement of abutments and bolt members is utilized to support the circuit interrupter bottle apparatus 32 and associated contact members 34 and 36, for example. A rearwardly extending aluminum support member 48 is fastened by way of bolt member 68 to the bottom of the aforementioned abutment 46 at the left as shown in FIGS. 5 and 20, for example. An abutment member 72 which protrudes from the side wall of the aforementioned insulating housing 42 cooperates with a vertically oriented bolt member 74 to secure another portion of the aluminum support member 48 to a sidewall of the housing 42. The housing 42 is conveniently supported by the horizontally extending insulators 28 and 30 as is best shown in FIG. 3, for example. A circular opening 50b is disposed in the support member 48. Opening 50b has a radius generally equal to the radius of a bottom portion of the circuit interrupter vacuum bottle apparatus 32. The latter two portions interact to seat the circuit interrupter apparatus 32 in the horizontal support plate 48. A rectangular member 52 having a central circular hole 56 disposed therein is securely fastened to the underside of the support member 48 by way of bolts 51 which protrude upwardly into threaded complementary openings in the support member 48. Adjustable bolt members 57 protrude upwardly through plate 52 to adjustably bear against the aforementioned circular end portion 50 of the circuit interrupter 32 to maintain the conducting end plate 32a thereof vertically spaced from the top of the aluminum support plate 48. The vertical spacing is represented at 50a, for example, in FIG. 20. This prevents significant electrical current from flowing through the aforementioned aluminum support plate 48. The bottom contact stem 56a of the movable contact of the vacuum circuit interrupter 32 protrudes downwardly through the opening 56 in the aforementioned rectangular plate 52. Layered conductor packets or assemblies 78 are interconnected with the aforementioned stem 56a by way of the aforementioned interconnection assembly 76.
Referring now specifically to FIG. 5 it can be seen that the stiffened flexible conductor assemblies 78 are partially supported below the support member 48 by way of securing nut and bolt assemblies 80 and 82. The nut and bolt assembly 82 also interconnects the conductor assemblies 78 with the electrical terminal 36. The characteristic V-shaped pleat or undulation in the conductor assembly 78 horizontally compresses the assemblies between the assembly 76 and the terminal 36 without reducing flexibility for accommodating the travel of the stem 56a in the vertical direction. An electrically conducting support member 60 is bolted to and supported by horizontal protrusions 44 and 66 of the aforementioned electrically insulating housing member 42. Bolts 62 and 64 are provided for vertically securing member 60 to the protrusions 44 and 66 from the top, respectively. The upwardly extending stem of the generally non-moving contact of the circuit interrupter bottle 32 is securely attached to the electrically conducting member 60 by way of securing bolt 58a. Disposed at the rightward end of the electrically conducting member 60 as viewed in FIG. 5 is the aforementioned high voltage terminal 34.
Referring now to FIGS. 7 through 19 the component parts of the attachment assembly 76 and the conductor assembly 78 are depicted. By referring to these latter-mentioned Figures in conjunction with previously described FIGS. 20 and 21 the construction and operation of the stiff flexible conductors and the way they are attached to the stem 56a is described in detail.
Referring specifically to FIGS. 7 and 8 a unitary stiff, yet flexible, electrically conducting member 100 is shown. The member 100 is stiff in that it has the characteristics of being able to support itself in the horizontal without completely drooping to the near vertical disposition as braided copper wire would do in a similar circumstance. However, it is flexible enough to accommodate a certain amount of vertical movement at one end when it is disposed in the horizontal disposition. A pleat 108 is disposed therein for purposes described previously. At one end of the relatively flat rectangularly shaped thin member 100 is disposed an opening 104a having a radius slightly smaller than the radius of the stem 56a of the circuit interrupter bottle 32. Radial slits or cutouts 102 are disposed around the periphery of the opening 104a thus forming tabs 104 which are then slightly offset from the flat planar surface of the member 100 as is best shown in FIG. 8. Holes or openings 83 and 85 are disposed in the other end of the relatively flat member 100 for interconnection with the fastening apparatus 80 and 82, respectively, as was described previously with respect to FIG. 20. The use of the aforementioned tabs 104 will be described hereinafter.
Referring now to FIGS. 9 and 10, a nonmagnetic steel rectangularly shaped compression member 110 is depicted. Member 110 has a central opening 112 which is of sufficient diameter to allow the stem 56a to easily pass therethrough. Outwardly disposed therefrom are openings 114 into which are pressed internally threaded members 116 for accepting complementary threaded portions of bolt members 150 shown in FIG. 20.
Referring now to FIGS. 11 and 12 a copper tabbed compression member 118 is shown. The copper tabbed compression member 118 has a circular central opening 123 which is generally of the same diameter as the central opening 104a of the member 100 shown in FIG. 7, for example. Slits or cutouts 120 are radially placed around the central opening 123 in a manner similar to that described with respect to the member 100 of FIG. 7. Consequently, offset tabs 122, best seen in FIG. 11, similar to tabs 104 of FIGS. 7 and 8 are formed. In a like manner outwardly disposed holes or openings 124 are placed in the member 118 for alignment with similar holes or openings 106 in the member 100. In a preferred embodiment of the invention a plurality of alternating members 100 and 118 are disposed around an axial portion of the shaft of the stem 56a of the circuit interrupter bottle 32 thus forming a flexible electrically conducting portion 78 such as shown in FIG. 20. It will be noted that the alternating arrangement of the members 100 and 118 form a plurality of separated flexible electrical conductors within each electrically conducting portion, packet or assembly 78. Each of the members 100 makes "three-point" electrical contact with the stem 56a. Consequently, if there are ten of the members 100, for example, in a typical section 78, thirty points of electrical contact will be made with the stem 56a. This has a tendency to decrease contact resistance for a given volume of electrical conductor while at the same time rendering the contact portion 78 relatively flexible. The aforementioned tab members 104 and 122 when stacked in the previously described alternating arrangement and compressed axially of the stem 56a deform to flow around the surface of the stem 56a to accommodate the smaller radius of the circular holes 123 and 104a thus, providing reduced electrical contact resistance between the members 100 and the stem 56a.
Referring now to FIGS. 13 and 14 an intermediate compression member 126 is depicted. Member 126 has a central opening 128 which has a radius sufficiently large to allow the stem 56a to conveniently pass therethrough without deformation. Furthermore, four openings 130 may be provided which align with the openings 124 of the member 118 and the openings 106 of the conducting member 100, for example. The purpose of the utilization of the member 126 will be described more fully hereinafter.
Referring now specifically to FIGS. 15 and 16 a compression member 132 which is similar to compression member 126 is depicted. Compression member 132 differs from compression member 126 in that the central opening 136 of the compression member 132 is significantly smaller in radius than the central opening 128 of the member 126. This is due to the fact that the lower end portion of the shaft 56a has a reduced-radius threaded portion thereof which conveniently fits through the opening 136 so that the member 132 may conveniently fit over the threaded portion without fitting over the main shaft of the stem 56a. This in essence abuts the member 132 against the bottom of a significant portion of the stem 56a.
Referring now to FIGS. 17, 18 and 19 a metal bell crank-to-stem force transfer member 138 is depicted. Member 138 has vertically rising lips 147 on two opposing sides thereof and relatively larger vertically rising members 140 on the other two opposing sides thereof. Holes or openings 146 which align with the previously described holes or openings 130, 134, 124 and 106 are provided. Furthermore, a central opening 148 which fits around the reduced threaded portion of the shaft 56a much in the way that the hole 136 of member 132 does is also shown. In the vertically rising portions 140 a circular hole 142 is disposed for interconnection with pivot pins 97 of the bell crank assembly in a manner to be described hereinafter with respect to FIG. 6.
Referring once again to FIG. 20 the intercooperation of the elements of FIGS. 7 through 19 in forming the electrically conducting tap-off assembly 76 is described. In the construction process the central opening 112 of the member 110 is passed along the shaft 56a. Next, a plurality of stacked alternating members 110 and 118 are slid over the shaft 56a. It is to be noted with respect to the tabs 122 and 104 of members 118 and 100, respectively, that the offset thereof from the flat surface slightly increases the diameter of the holes 123 and 104a, respectively, so that the stacked alternating members may be easily slid over the shaft 56a. Next, in a preferred embodiment of the invention two spacers 126 are slipped onto the shaft. Next, another assembly 78 which includes alternating members 100 and 118 are formed along the shaft in a manner previously discussed. Next, electrically conducting member 132 with its reduced central opening 136 is disposed over the threaded portion of the shaft 56a and abuts against the shoulder between the reduced threaded portion and the enlarged shaft of the member 56a. Finally, in this embodiment of the invention the member 138 is disposed in a manner shown with respect to FIG. 20 and a bolt (not shown in FIG. 20) is disposed over the reduced threaded portion of the member 56a thus compressing the main body of the member 138 against the member 132 and thus against the lower shoulder of the shaft 56a thus securing the latter two members to the shaft 56a. Lastly, bolt members 150 are fed through holes 146 of member 138, holes 134 of member 132, holes 106 of member 100, holes 124 of member 118, holes 130 of member 126 and finally into the threads of the lipped members 116 of the uppermost compression member 110. The bolts 150 are then drawn tight thus compressing or sandwiching all of the aforementioned members together causing the aforementioned tabs 104 and 122 to align themselves with the planes of the surface in which they are disposed thus causing the openings 104a and 123 to reduce in radius thus causing the edges of the tabs to cold flow around the stem 56a. This then provides a convenient way to interconnect a circular vertically moving member 56a with a relatively stationary terminal such as 36 shown in FIG. 20. This is done with a high degree of reduced electrical surface contact resistance and with sufficient flexibility to allow the shaft 56a to move upwardly and downwardly (with respect to FIG. 20) to thus accommodate the opening and closing of the contacts of the circuit interrupter bottle 32. A single non-layered assembly for replacing assembly 78 would be too stiff to accommodate the movement of the stem 56a. The geometry of assembly 78 is such that each member 100 therein can independently move in a limited way between the stem 56a and the first tie down point at 80.
Referring now to FIG. 6 the linkage arrangement 38 for interconnecting the circuit interrupter of the high-voltage section 26 with a force providing apparatus such as a motor or crank in the low-voltage section 24 is shown. A crankshaft member 86 may be pivotally attached to an insulating rod 84 the other end of which is interconnected with one pivot pin 88a of a bell crank 88. There are disposed in the previously mentioned insulating housing support member 42 two vertical protrusions 94 and 96 which are utilized to vertically support an insulating base 92 on which the aforementioned bell crank 88 is pivoted at 90. A third pivot 97 of the bell crank member 88 is interconnected with the member 138 (not shown) in the journals 142 (not shown) thereof so that the shaft 56a may move upwardly and downwardly as viewed in FIG. 6 as the crank mechanism 86 rotatates causing the insulating shaft 84 to move in a substantially horizontal direction is shown in FIG. 6. Of course, as shaft 56a moves upwardly and downwardly the electrically interconnecting attachment device 76 and its associated stiff flexible contact portions 78 move upwardly and downwardly in a corresponding fashion. Were it not for the flexibility of the portion 78 the member 76 would deter or prevent the stem 56 from operating under the influence of the bell crank 88. Regardless of the flexibility of the member 78, however, the unique arrangement of the interconnection in the interconnecting device 76 provides for low resistance contact between the stem 56a and the flexible conductors 78.
Referring now to FIGS. 22 and 23 another embodiment of the invention is shown which is useful for relatively higher ranges of operating current. Generally like elements are identified by like reference symbols in regard to other embodiments and drawings of this invention. On the other hand elements which are merely related but not similar are identified with primed (') reference symbols. For example, the circuit interrupter bottle of the embodiment of FIGS. 22 and 23 is identified by the reference symbol 32' indicating that it is different from the circuit interrupter 32 of other embodiments and other Figures. Generally, elements 100', 110' and 118', 126' 132' and 138' are similar but relatively larger than elements 100, 110, 118, 126, 132 and 138 of FIGS. 20 and 21. Two notable differences lie in the fact that the central circular opening in the present case is larger than the corresponding central circular openings 104a, 112, 123, 128, 136 and 148, respectively. Further, the bolt holes in the present embodiment are slightly larger in diameter and further offset from the center of each element than the corresponding bolt holes 106, 114, 124, 130, 134 and 146 of the embodiments of FIGS. 20 and 21. Still further differences lie in the fact that three spacer elements 126' are utilized rather than two, and that more interleaved combinations of the elements 118' and 100' are utilized per packet or portion of flexible electrical conductor 78' than in the other embodiment of the invention and that the bell crank interconnecting insulating device 138' is utilized in a reversed or upside down disposition relative to the embodiments of FIGS. 20 and 21. With regard to the interconnection of the electrically conducting flexible portions or packets 78' in the present embodiment of the invention it should be noted that the aforementioned portions 78' are interconnected with a main terminal 36' at interconnecting portion 36a' by the utilization of an interconnecting bolt 85' and fastening apparatus 82'. Spacers 152a' associated with bolt 80' also differ from the spacer arrangement shown with regard to FIG. 20, for example. It is also to be noted that the terminal 36' is of a larger size and different construction than the terminal 36 of FIG. 20, for example. Otherwise, the operation of the apparatus shown in FIG. 22 is similar to the operation of the apparatus shown in FIG. 20 in that a bell crank member (not shown) interconnected at 97 with the interconnecting member 138' is utilized to cause the stem 56a' to move upwardly and downwardly to close and open, respectively, the contacts of the vacuum circuit interrupter apparatus bottle 32' while the flexible conductors of the packets or portions 78' move or flex accordingly.
Referring now to FIGS. 24 and 25 still another embodiment of the invention is shown in which a vacuum circuit interrupter 32 is disposed electrically between two high-voltage terminals 172 and 174. The aforementioned high-voltage terminals and vacuum interrupter are insulatingly spaced apart at appropriate places by the insulators 160, 162, 164 and 168. Electrical interconnecting apparatus shown at 178 is utilized in cooperation with an insulating movement providing means 176 to cause packets 78" of stiff flexible conductors 100" to conduct current for the circuit interrupter bottle 32. By reference to FIG. 24 a top view of a stiff flexible conductor 100" is shown. Four holes 182 are disposed at the ends of the conductor 100" and a central hole 184 is disposed in the center to accommodate the interconnection between the force providing apparatus 176 and the stem interconnection apparatus 178 of FIG. 25. Because of the relatively large current carrying capability of the conductor 100" offset holes 180 are disposed in the main body of the conductor to assist in dissipating heat. Furthermore, as is best seen in FIG. 25 the entire conductor 100" is disposed between the insulators 160 and 168 to provide a larger heat radiating surface than would normally be found if the conductor were merely disposed between the connecting portion 178 and the insulator 168. This means that electrical current substantially flows in that portion of the conductor 100" between the connecting member 178 and the terminal 172, for example, while virtually no current flows to the left towards insulator 160. As can also be seen in FIG. 25 the conductors 100" are fabricated to have an accordion-shaped, pleated-shaped or undulating side elevation. This not only enhances the heat dissipation characteristics but provides for utilizing the entire flexible characteristic of the conductor 100" while reducing the distance between the members 178 and 172, for example.
It is to be understood with respect to the embodiments of this invention that the concepts taught here are not limited to use with vacuum circuit interrupters. Moreover, it is to be understood that the number of tabs around the periphery of the central opening of the apparatus of FIG. 7 or FIG. 8 is not limiting. It is also to be understood that the particular compression apparatus for causing the offset tabs to become realigned with the plane of the conductor is not limiting. It is also to be understood that the apparatus taught herein is not limited to use with a circular stem but further may be used with other geometric shapes provided the teachings herein concerning the compression of the tabular members and a flowing of the electrically conducting member around the stem member are followed. It is also to be understood that the number of packets 78, 78' or 78" are not limiting.
The apparatus taught with respect to the embodiments of this invention has many advantages. One advantage lies in the fact that current may be transferred from an elongated terminal stem or conductor to a relatively flat conductor by utilizing the teachings of the present invention. In a preferred embodiment of the invention electrical current may be transferred from a circular member through a high conductivity, low resistant joint to a relatively flat member. Another advantage lies in the fact that by using multiple flat conductors in conjunction with a single circular stem in a laminate and tab construction a given volume of copper in a circular to flat interface of multiple three-point contacts may be utilized for transferring current between the latter two members through an interface of significantly reduced contact resistance. | Electrical apparatus and more particularly vacuum electrical circuit breaker apparatus is taught. The electrical apparatus has a cylindrical movable terminal stem which is to be interconnected with a fixed terminal by way of a flexible conductor which is nevertheless relatively stiff and self supporting. This is accomplished by using interlayered elongated rectangular plates or sheets between the two aforementioned terminals. Connection to the circular stem is made by utilizing offset tabs around the periphery of a central hole at one end of each of the sheets. The offset allows the tabbed opening to be inserted over the stem. After which the tabs are sandwiched or compressed to lie in the plane of the sheet thus causing the edges of the tab to flow around the stem reducing contact resistance. Because there are multiple sheets in each flexible conductor packet, the number of three point contacts between the flexible conductors and the stem is increased. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to digital communication systems and methods, and more particularly to phase, frequency and gain characterization and mitigation in SCDMA burst receivers using multi-pass data processing.
2. Description of the Prior Art
Data-Over-Cable Service Interface Specifications (DOCSIS) is a standard for data communication over cable TV infrastructure. This standard is published by CableLabs, a North American consortium founded by members of the cable TV industry. DOCSIS 2.0 was published on Dec. 31, 2001, and includes several important modifications to the previous version, 1.1. One of the most important additions is SCDMA mode in the upstream channel, which is discussed herein below.
The cable network consists of multiple clients (CMs—Cable Modems) connected to the central station (CMTS—Cable Modem Termination System). All clients in a certain region share the same cable infrastructure (similar to sharing the radio spectrum in radio transmission).
The cable spectrum is divided into upstream (from the CM to the CMTS, in frequency range 5–42 MHz) and downstream (CMTS to CM, frequency 50 MHz and above). The more complicated part is the upstream, since there are many transmitters, which need to be synchronized in order to avoid collisions.
The physical layer implementation of the upstream receiver, in the CMTS is critical for identification, characterization and compensation of impairments, especially for burst reception applications. The physical layer is described in chapter 6 of the DOCSIS specification, and the upstream is described in sub-chapter 6.2.
Upstream channels are located in the range of 5-42MHz, as stated herein before. In that range, there can be several different channels (FDMA—Frequency Division Multiple Access). Each channel includes many CMs, which transmit short bursts (and not a continuous transmission). The bursts are multiplexed using one of 2 methods:
1. TDMA—Time Division Multiple Access—bursts are transmitted in different times, synchronized by the CMTS. 2. SCDMA—Synchronized Code Division Multiple Access—bursts from several CMs are multiplied by different sets of orthogonal codes, and transmitted simultaneously.
FIG. 1 illustrates a CM upstream transmitter; while FIG. 2 illustrates a CMTS upstream receiver.
When transmitting in SCDMA, the time line is divided into frames. Each frame has 128 rows, wherein each row corresponds to a different code. Each column in the frame is called a spreading interval. The number of spreading intervals per frame (abbreviated spif) can change, depending on the transmission parameters. FIG. 3 emphasizes the relationship between frames, codes, mini-slots and spreading intervals.
The number of cells in each frame is spif*codes_num. In each cell in the frame there is a single symbol, which is represented as a complex number, or an I-Q pair (In-phase and Quadrature, or real and imaginary parts), and matches the constellation chosen for the burst.
Each CM that wants to transmit is assigned a certain number of mini-slots. Each mini-slot consists of a number of codes in a specific frame.
Before transmitting, the frames are passed through a spreader. The spreader takes each spreading interval (a vector of 128 symbols), and multiplies it with the spreading matrix—a matrix the size of 128×128:
p k = s k ·C
Each row in the spreading matrix C is a code, and each entry is +1 or −1. The codes are orthogonal, so C is invertible:
C - 1 = 1 128 C t ⇒ 1 128 C · C t = I 128 × 128
The s k term is a vector which contains the 128 information symbols of the k'th spreading interval.
The result of the multiplication, p k , is a vector of chips. FIG. 4 shows the symbols and chips in the complex plane. Note that the symbols correspond to the chosen constellation (in this case 16-QAM), while the chips are scattered:
The chips are then transmitted sequentially. All the CMs that were allocated mini-slots in the current frame transmit their chips simultaneously; hence the chips received in the CMTS receiver are the sum of all transmitted chips.
p _ k received = ∑ i ∈ CMs p _ k i
The receiver multiplies the received chips with the inverted spreading matrix C t , and restores the original transmitted symbols. This action is done in the despreader:
s ⋒ _ k = 1 128 p _ k received · C t = 1 128 ∑ i ∈ CMs p _ k i · C t = 1 128 ∑ i ∈ CMs s _ k i · C · C t = ∑ i ∈ CMs s _ k i
Note that the resulting symbols vector {circumflex over ( s )} k is the sum of all the vectors of the transmitting CMs; but since each CM is assigned different rows, there's no collision between symbols. For example, if CM #1 is assigned codes 0 through 63, and CM #2 is assigned codes 64 through 127, then s k 1 is only non-zero in indices 0 . . . 63, and s k 2 is in indices 64 . . . 127, so there's no collision in ŝ k (which is the sum of both vectors).
The basic idea behind spreading is to “spread” the signal on a larger frequency span. After despreading, the signal is back to its original from, and added narrowband interferences are “spread”, as shown in FIG. 5 .
Each burst begins with a set of pre-defined symbols, called a preamble. The preamble enables the receiver to obtain a rough estimation on the burst's impairments, such as gain, phase and frequency offsets, by comparing the received symbols to the known preamble symbols that were actually transmitted.
In summary explanation of the above, a high-level receiver algorithm
1. Performs down-conversion and reduces signal rate to the chips rate; 2. Despreads the chips, one spreading interval at a time; 3. Stores the symbols in the deframer, until an entire frame has arrived; and 4. For each burst in the current frame:
a. Processes the preamble to get an initial estimate of the gain, frequency and phase offsets;
b. Passes the burst through the big-loop for a fine track and fix of the gain, phase and frequency offsets. The “fixed” symbols are written back to the deframer's memory; and
c. Outputs the burst for symbol de-mapping and channel decoding.
The transmitted signal is modulated over a carrier frequency. Synchronization mismatch between the transmitter and the receiver may cause phase and frequency offsets in the received signal. Unless dealt with, these offsets will cause errors in the transmission.
Phase offset causes all the received symbols to appear with a constant phase shift. Frequency offset causes the symbols to appear with a changing phase shift, as can be seen in FIG. 6 .
Phase and frequency offsets are parameters that can be tracked from the received symbols, using a Phase Lock Loop (PLL). FIG. 7 shows a basic diagram of a PLL. This is a 2 nd order PLL that tracks the symbols' phase (the 2 nd order loop is required due to the existence of both frequency and phase offsets).
Without the 2 nd order loop (frequency estimation, shown in the lower part of FIG. 7 ), the PLL would only be able to track signals with no frequency offset. If there were a frequency offset, the PLL would be able to eliminate it, but have a constant phase error. Thus, the need for a 2 nd order loop—to estimate the frequency offset, and add it to the phase estimation.
The design of the basic PLL is based on the assumption that the symbols are entering the loop in the same order as they were transmitted. This is especially important for the frequency estimation, as we can see that the frequency correction is added to the phase estimation in every clock tick (i.e. new symbol).
When using SCDMA, the phase and frequency offsets affect the chips instead of the symbols. However, using an ordinary PLL on the chips (before despreading) is impossible, since it requires slicer decisions while the chips are scattered and does not comply with a constellation; so there's no way to estimate the phase offset of each chip.
Using a PLL after the despreader poses a new problem: the symbols are organized in frames, and are no longer serial in time. Without spreading, a frequency offset is manifested in a linear change of the phase, but after the despreader one sees a different picture:
In FIG. 8 , three consecutive spreading intervals of 16-QAM symbols (a total of 3*128=384 symbols) in their original form (1), are seen after spreading (2), adding a frequency offset (3) and despreading (4). It's possible to see that the symbols after despreading no longer have a linear phase, but are divided to 3 groups, each group corresponding to a spreading interval. When comparing the phase of the symbols to the transmitted ones, one sees the picture depicted in FIG. 9 .
In FIG. 9 , one can see that the chips' phase after adding the frequency offset is linear, as expected, but the symbols' phase forms “steps”, in which each step corresponds to a spreading interval. The average phase of the symbols in each spreading interval is similar to the average phase of the chips, but it does not change linearly. The reason one sees these steps is that each symbol in spreading interval k is a linear combination of all 128 chips of that spreading interval, and is therefore affected by all 128 different phases.
The result is groups of 128 symbols with approximately the same phase, and the phase difference between successive groups is 128×phase_offset_per_chip. This complicates the phase offset tracking since the loop needs to track an impairment 128 times larger than it should have, in case SCDMA was not used. Also, since the “adding” of a frequency offset is not a linear action (multiply each chip by a growing exponent), one cannot model the change in phase as a linear process.
In view of the foregoing, it is both desirable and advantageous to provide a mechanism for phase and frequency tracking in a SCDMA channel that overcomes the above problems. This mechanism should provide phase, frequency and gain characterization and mitigation in a SCDMA burst receiver via use of dedicated phase and frequency correction loops implemented to deal with the unique characteristics of a SCDMA signal.
SUMMARY OF THE INVENTION
DOCSIS 2.0, the new standard for cable upstream transmission, added SCDMA to the allowed modulation schemes. The present invention is directed to a scheme to provide phase, frequency and gain characterization and mitigation in a SCDMA burst receiver via use of dedicated phase and frequency correction loops implemented to deal with the unique characteristics of a SCDMA signal. The way coded and un-coded bits are interleaved within a given frame requires that all symbols related to that frame be captured in a dedicated storage medium such as a RAM prior to the beginning of the data processing. The present invention substantially eliminates gain, phase, and frequency mismatch, among other impairments caused by the transmitter, channel and analog parts of the SCDMA burst receiver.
Since the incoming SCDMA burst receiver data is saved in a frame, multiple passes can be performed on the data. The first pass can be used to produce initial characterization of the phase, frequency and gain offsets affecting the incoming signal; where the second pass can be used to more accurately estimate those impairments (using a smaller step size in a LMS algorithm), and compensate for those impairments.
According to one embodiment, multiple passes are performed on the received sequence. The first pass can be used to achieve a good characterization of the various impairments; and the last pass would use the information obtained from previous passes to properly correct the impairments. Each pass may be performed column-wise or row-wise. By performing the pass column-wise, all the symbols related to the same spreading interval are analyzed sequentially, resulting in higher capability to characterize phase offset. By performing the pass row-wise, each symbol is related to a different spreading interval that was transmitted in a different time, resulting in higher capability to characterize frequency offset.
As used herein, the following terms have the following meanings:
FDMA means Frequency Division Multiple Access. TDMA means Time Division Multiple Access. SCDMA means Synchronized Code Division Multiple Access. Burst means a data batch that's transmitted from a single CM. Frame means a 2-dimensonal array of symbols. Each column corresponds to a single spreading interval. Each row corresponds to a single code. There are 128 rows (codes) per frame, and a variable number of columns (spreading intervals). Spreading interval means a vector of symbols which are processed simultaneously in the spreader/despreader. Each spreading interval is a single column in a frame. Symbol means a complex number representing a certain number of bits. Each symbol is composed of an ‘I’ value (real part) and a ‘Q’ value (imaginary part). Chip means the basic data unit of a spread signal. Each spreading interval contains 128 symbols before spreading, which turn into 128 chips after despreading. CM means Cable Modem. CMTS means Cable Modem Termination System. SPIF means Spreading Intervals per Frame. PLL means Phase Lock Loop, used for tracking a changing signal. fstep means Frequency step. pstep means Phase step. MSE means Mean Square Error.
BRIEF DESCRIPTION OF THE DRAWINGS
Other aspects and features of the present invention and many of the attendant advantages of the present invention will be readily appreciated as the invention becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing figures thereof and wherein:
FIG. 1 is a block diagram illustrating a CM upstream transmitter;
FIG. 2 is a block diagram illustrating a CMTS upstream receiver;
FIG. 3 is a diagram illustrating frames, codes, mini-slots and spreading intervals in which there are 2 codes per mini-slot;
FIG. 4 compares symbols and chips in a complex plane;
FIG. 5 is a pictorial illustrating signal spreading and dispreading to help deal with narrowband noise;
FIG. 6 is a pair of plots illustrating phase and frequency offsets in a 16-QAM constellation;
FIG. 7 illustrates a standard PLL for phase tracking;
FIG. 8 shows a series of plots illustrating the effect of frequency offset in S-CDMA;
FIG. 9 is a plot illustrating a phase shift due to frequency offset, before dispreading (chips) and after (symbols);
FIG. 10 illustrates a big-loop module for a CMTS upstream receiver;
FIG. 11 a illustrates passing symbols to a PLL row after row;
FIG. 11 b illustrates passing symbols to a PLL column after column;
FIG. 12 is a more detailed diagram illustrating the phase loop portion of the big-loop shown in FIG. 10 ;
FIG. 13 is a diagram illustrating a fixed-point representation for signals passed to the phase loop shown in FIG. 12 ;
FIG. 14 highlights the error discriminator portion of the phase loop shown in FIG. 12 ;
FIG. 15 highlights the pstep and fstep portions of the phase loop shown in FIG. 12 ;
FIG. 16 highlights the frequency accumulator portion of the phase loop shown in FIG. 12 ;
FIG. 17 highlights the phase accumulator portion of the phase loop shown in FIG. 12 ; and
FIG. 18 highlights the phase difference calculation engine portion of the phase loop shown in FIG. 12 .
While the above-identified drawing figures set forth particular embodiments, other embodiments of the present invention are also contemplated, as noted in the discussion. In all cases, this disclosure presents illustrated embodiments of the present invention by way of representation and not limitation. Numerous other modifications and embodiments can be devised by those skilled in the art which fall within the scope and spirit of the principles of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 10 illustrates a big-loop 10 for a CMTS upstream receiver. The modules in the big-loop 10 can be seen to include a Gain module 12 that adjusts the symbols' gain, a Rotator module 14 that adjusts the symbols' phase, and a Slicer module 16 that performs hard-decision slicing of the symbols, according to the specified constellation (qam_mode). The slicer's input, discussed herein below, is regarded as soft-decision data. Other modules in the big-loop 10 also include a Ploop (Phase-loop) module 18 for tracking phase and frequency offsets, a Gloop (Gain-loop) module 20 for tracking gain offsets, and a Step-size-calc module 22 that calculates the step sizes for the various loops.
The goal of the ploop module 18 is to estimate the phase offset affecting the incoming signal, and use it to predict the rotation angle needed to correct this impairment. The ploop module 18 inputs are the slicer module 16 outputs (hard-decision) and input (soft-decision). The slicer module 16 processing time is 1 clock cycle. Therefore, in order to synchronize both signals, the slicer module 16 input is delayed by one cycle as well, calling it slicer_in_p (enumerated 21 , and where p indicates pipeline).
The ploop module 18 then uses its inputs to determine the symbol's phase offset, and uses this data to estimate the phase offset needed for the symbol now entering the Rotator module 14 . This estimate (called phase_error) 24 is passed to the Rotator module 14 . The Rotator module 14 employs a lookup table (sin_lut) to calculate necessary sine and cosine values for rotating the symbol. Due to hardware considerations, each module has its own processing delay as shown in Table I.
TABLE I
Module
Delay (clock cycles)
Gain
2
Rotator
1
Sin_lut
1
Slicer
1
Ploop
1
Gloop
1
Control signals shown in FIG. 10 (grouped for convenience under the signal name control) are pipelined through the different modules, so their timing matches the symbols. The naming convention for these pipelined signals is shown in Table II.
TABLE II
Delay (clock cycles)
Name
0
control
1
control_p
2
control_p1
3
control_p2
4
control_p3
As described herein before, when the big-loop 10 starts its operation, the frame had already passed the despreader (shown in FIG. 2 ) and is located in the deframer's memory (also shown in FIG. 2 ), and an initial gain, phase and frequency offsets estimation for the current burst was already performed. Since the data is not sequential (the big-loop 10 has access to the entire frame), it can now be processed “offline”, in any order as desired (as long as the processing is completed before the next frame arrives). Several processing paradigms that use this advantage are described herein below in order to provide a better understanding of the preferred embodiments.
Two Passes
Each frame is passed through the big-loop 10 twice. In the first pass, the goal is to “train” the loop 10 by tracking the phase and frequency offsets of the burst, without writing the corrected symbols back to the deframer. This allows the loop to train on the entire burst before making any changes. In the second pass, smaller learning factors are taken (to reduce loop jitter), and the symbols will be changed according to the trained loop.
Passing by Rows or Columns
In a conventional PLL, symbols entering the loop are chronologically sequential. In the present case, the symbols are arranged in a 2-dimensional frame. Each column (spreading interval) contains symbols transmitted in the same time (and hence has approximately the same phase offset, see FIG. 9 ). There are 2 options for passing the symbols to the loop (as illustrated in FIGS. 11 a and 11 b ):
1. Rows pass—Pass the symbols to the loop 10 row after row, while maintaining a one spreading interval distance between sequential symbols. In this method, each two sequential symbols have a phase difference between them (except at the end of the rows).
2. Columns pass—Pass the symbols to the loop 10 column after column.
In order to estimate the frequency offset, it is necessary to look at symbols that differ in phase as a result of the frequency offset (i.e. symbols from different spreading intervals). In rows pass, almost every two successive symbols have this difference, while in columns pass, this difference is seen only once per spreading interval. Hence, better frequency convergence can be expected when using rows pass.
On the other hand, since in columns pass there are less frequency “events”, better phase convergence can be expected.
Frequency Update in Columns Pass
As stated herein before, when using a columns pass, the effect of a frequency offset is only felt once per spreading interval. Therefore, there can be two approaches towards the 2 nd order of the ploop 18 (the frequency offset):
1. The conventional PLL approach—update the 2 nd order (i.e. the frequency correction accumulator) each time a new symbol arrives.
2. Update the 2 nd order only in a “frequency event” i.e. when we pass from one column to the next. According to this approach, symbols in the same column are not affected by a frequency offset, and so only the 1 st order of the loop is needed. At the end of each column, check the total change of the 1 st order over the column (by comparing the phase accumulator at the end and beginning of the column). This change is the frequency error, which will be taken into account when updating the frequency accumulator.
Loop Delay
The phase loop (rotator-slicer-ploop-sin_lut-rotator) shown in FIG. 10 has a total delay of 4 clock cycles as can be seen with reference to Table I. This means that the symbols in the ploop's input and output may be up to 4 symbols apart (dependent on the rate the symbols are sent to the big-loop). They might be in different rows, or different columns, and the ploop 18 must take that into consideration.
The result is a division of the ploop 18 into 2 stages as shown in FIG. 12 .
1. An input stage 30 , which needs to be synchronized with the symbols at the input of the ploop (i.e. slicer output), thus using control signal control_p 3 .
2. An output stage 32 , which needs to be synchronized with the symbol entering the rotator (p 1 ), while taking into consideration the delay of the sin_lut (1 cycle) and the ploop itself (1 cycle), thus using control signal control.
The timing difference between the inputs of the input and output stages 30 , 32 (control and control_p 3 ) is 4 clock cycles—the total delay of the loop.
A detailed description directed to one embodiment of a loop is now presented herein below in view of the basic processing paradigms discussed herein above, which are the heart of the invention. In order to enhance clarity, this detailed description is divided into sections describing each component of the loop.
Fixed-Point Values
All values are passed in fixed-point representation, and as such have two important parameters—the bus width (in bits) and the max-level. For example, the value q_slicer_in is 9-bit with max-level of 32. This means that it's represented as shown in FIG. 13 . Unsigned values are marked with the letter u (for example, the value phase_acc). This means that there's no sign bit. Limiters are marked with the letter L. These components are used when it is desired to limit the max-level of the incoming signal. If the value in the limiter's input is higher than the limiter's defined max-level, it will be truncated to the maximal allowed value (when using signed values; the same applies for values lower than the min-level). Truncaters are marked with the letter T. This is not really a component, but simply means dropping some least-significant bits, to reduce precision. Rounders are marked with the letter R. These components are used when it is desired to reduce the precision of a value in a more accurate way. Instead of truncating the value, the value is rounded.
Error Discriminator
The Error Discriminator 34 portion of the phase loop module 10 (depicted in FIG. 14 ) is responsible for determining the phase error, by comparing the symbols before and after slicing. The phase error is approximated the following way:
phase_error =
= Re ( sym_in ) · Im ( sym_out ) - Im ( sym_in ) · Re ( sym_out ) =
= Im ( sym_in · sym_out * ) =
= Im ( r i n · r out · ⅇ j ( θ i n - θ out ) ) =
= r i n · r out · sin ( θ i n - θ out ) ≅
≅ r i n · r out · ( θ i n - θ out )
where sym_in and sym_out represent the symbol in the slicer's input and output respectively (reminder—i_slicer_in is the real value of the symbol in slicer_in, and q_slicer_in is its imaginary value).
The phase error is multiplied by constant factors (called step sizes) along the way, in order to reduce noise effect (much like a conventional PLL). Actually, since all the constant factors are powers of 2, multipliers are not utilized, and the only effect of the multiplication is the change in the max-level of the fixed-point values.
Accumulators' Step Sizes
The step sizes 40 , 42 , shown in FIG. 15 , determine the loop's rate of convergence. A large step will result in faster convergence, but bigger steady-state jitter. Small steps reduce the jitter but converge slower. These trade-offs are analyzed in greater detail herein below. Two step-sizes are used in the ploop 18 :
pstep—Step size for the phase accumulator. The phase error is multiplied by pstep before entering the accumulator. fstep—Step size for the frequency accumulator. Actually, the real step size is pstep*fstep, since the phase error is multiplied by both factors before entering the frequency accumulator.
Like the constants in the error discriminator 34 , fstep and pstep are powers of 2, so the multiplication is simply a bitwise shift. Since a columns pass generates fewer “frequency events” than a rows pass, it is expected that a larger fstep will be needed in order to compensate.
Frequency Accumulator
The frequency accumulator 50 , identified in FIG. 16 , is the heart of the 2 nd order loop, responsible for frequency offset estimation. After multiplying the estimated phase error by the fstep 42 , the result (signal acc_add_freq) is entered into the accumulator (i.e. added to the previous value). The value at the accumulator's output is called freq_acc. The sign of the phase error is determined by the direction of the last sideways movement (change of spreading intervals).
Phase Accumulator
The phase accumulator 60 , identified in FIG. 17 , accumulates the value of the last phase error, plus (or minus) the frequency estimation (freq_acc). The sign of freq_acc is determined by the movement direction in the frame as seen in FIG. 11 , as follows:
Right movement—moving from one spreading interval to the next one—add freq_acc. Left movement—moving from one spreading interval to the previous one—subtract freq_acc. Up/down movement—staying in the same spreading interval—don't use freq_acc.
The reason for this policy is simple—freq_acc is an estimation of the height of the “stairs” (as seen in FIG. 9 ), i.e. estimation of the phase offset between consecutive spreading intervals. Right movement can be seen as going up the stairs (adding that phase offset), and left movement as going down the stairs (subtracting that phase offset). The movement direction is indicated by control signal direction_p 0 (note that control signal direction_p 0 is a p 0 signal, with timing that matches the output stage of the loop).
Phase Difference Calculation
When updating the 2 nd order only in a “frequency event” such as discussed herein before (frequency update), it is necessary to calculate the difference in phase between consecutive spreading intervals. This phase difference calculation sub-module 70 , identified in FIG. 18 , achieves that by sampling the phase accumulator every time the column changes, and subtracting the previously sampled value. After subtracting the estimated frequency offset, a frequency correction (signal phase_diff) is fed into the frequency accumulator. The moment of sampling is determined by the control signal sample_phase_old, which goes active when the input stage switches from one column to the next. Note that this section contains feedback from the output stage to the input stage, and uses control signals from both timing schemes. When subtracting freq_acc, the last direction change in the output stage (last_dir_p 0 ) is taken into consideration; but when determining the sign of phase_diff, the last direction change in the input stage (last_dir_p 3 ) is used.
Control Signals
As stated herein before, the control signals, described herein below, come with 2 different timing delays, for the input and output stages, and marked p 3 and p 0 respectively, where
control signal PP_done indicates that the preamble processing is finished, and the initial values of the phase and frequency offset can be sampled; control signal en_in_n is active when a new symbol is available at either input (p 3 ) or output (p 0 ) stage; control signal direction is a family of signals that indicates the relative horizontal position of the current symbol relative to the previous one. Possible values are 0, 1 or 2, which indicate right, left or no horizontal movement, respectively; control signal lock is active on the rightmost (last) column of the current frame. When this signal is active, the phase accumulator is sampled into a shadow register, to be used in the beginning of the next frame (in case the burst spans over more than one frame) control signal start_frame indicates the beginning of a new frame in the current burst. When this signal is active, the value of the shadow phase register is sampled into the phase accumulator; and control signal freq_mode states whether the frequency accumulator should work in mode A or B discussed herein before.
In view of the above, it can be seen the present invention present a significant advancement in the characterization and mitigation of impairments associated with SCDMA burst receivers. It should be apparent that the present invention represents a significant departure from the prior art in construction and operation. However, while particular embodiments of the present invention have been described herein in detail, it is to be understood that various alterations, modifications and substitutions can be made therein without departing in any way from the spirit and scope of the present invention, as defined in the claims which follow. | A method and apparatus provide phase, frequency and gain characterization and mitigation in a synchronized code division multiple access (SCDMA) burst receiver via use of dedicated phase and frequency correction loops that implemented to deal with the unique characteristics of a SCDMA signal. The way coded and un-coded bits are interleaved within a given frame requires that all symbols related to that frame be captured in a dedicated storage medium such as a RAM prior to the beginning of the data processing. The method and apparatus substantially eliminate gain, phase, and frequency, among other impairments caused by the transmitter, channel and analog parts of the SCDMA burst receiver. | 7 |
FIELD OF THE INVENTION
[0001] This invention relates to cutting blocks for food.
BACKGROUND OF THE INVENTION
[0002] Known cutting blocks are comparatively simple in construction, usually being in the form of a single wooden or plastic board. The disadvantage of such a cutting block is that when chopped food is to be put into a bowl or pan, an instrument such as a spatula or knife is used and, as a result, splinters or chips from the cutting block can be scrapped into the bowl or pan together with the food. This represents a health risk.
[0003] A further disadvantage is that when the cutting block together with the chopped food is lined so that the chopped food may be directly transferred into the bowl or pan, it is difficult to grasp the block, due to its considerable weight and absence of any handle, and it is easy to spill the food.
STATEMENT OF INVENTION
[0004] According to the present invention there is provided a cutting block comprising a first block part providing a first cutting surface thereon, a second block part providing a second cutting surface thereon, said first and second block parts being pivotably connected together for relative movement between a first position in which said first and second cutting surfaces are contiguous and coplanar and a second position in which said fist and second cutting surfaces subtend between them an angle of less than 180°, a handle extending outwardly from said fist block part, and actuation means operable to cause said relative movements.
[0005] Preferably said handle comprises a first handle part connected to said first block part and a second handle part forming part of said actuation means, wherein said actuation means extend from the handle to said second block part
[0006] Preferably said handle includes biasing means to resiliently bias said first ad second handle parts away from each other.
[0007] Preferably said actuation means comprise first and second levers, a part of said first lever forming said second handle part and being relatively moveable relative to said second handle part, and said second lever being connected to said first lever and extending laterally therefrom to translate the movements of said first lever from the handle to the second block part.
[0008] Preferably the second lever has extending there through a locating pin for limiting the movement of said second lever
[0009] Preferably the handle is provided with grinding beans for sharpening a knife.
[0010] Preferably the handle is provided with means for holding grinding material.
[0011] Preferably the handle is detachably mounted on said first block part.
[0012] Preferably the block member is provided with a drain hole and more preferably with a liquid draining groove which extends into the drain hole.
[0013] Preferably the cutting block is shaped to provide a recess within which is located a cutting knife.
[0014] According to the present invention there may also be provided a cutting block comprising a first block part providing a fist cutting surface thereon, a second block part providing second cutting surface thereon, said first and second block parts being pivotally connected together for relative movement between a first position in which said first and second cutting surfaces are contiguous and coplanar and a second position in which said fist and second cutting surfaces subtend between them an angle less than 180°, a handle extending outwardly from said first block part, and actuation means operable to cause solid relative movement of said first and second block parts from said first position to said second position said handle being provided with grinding means for sharpening a knife, and means located in one of said block parts accommodating a knife.
[0015] Accordingly the present invention provides, at least in one or more of its preferred embodiments, a multi-purpose cutting block and arranged so that the block is in two sections which can be folded to form a V-shape. The block may bold a knife and the handle may be provided with riding means for sharpening the rife at any time.
[0016] By folding the cutting block, after carrying out a food chopping operation, the chopped food can be collected at the bottom of the V-shape, thereby facilitating its transfer to, for instance, a bowl or pan.
[0017] Accordingly the present invention provides a cutting block which is multi-purposed in that it integrates the functions of a board, a knife sharpener, a knife located within the board and the folding facility allow easy transfer of food. The cutting block in accordance with the invention reduces health risk, is labour saving and is convenient to use.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] An embodiment of the present invention is illustrated in the accompanying drawings, by way of example only, in which:
[0019] [0019]FIG. 1 is a perspective view from above of a cutting block of the invention;
[0020] [0020]FIG. 2 is a schematic drawing of the handle and associated folding actuator of the block of FIG. 1;
[0021] [0021]FIG. 3 is a perspective from above of the block of FIG. 1 in its folded configuration; and
[0022] [0022]FIG. 4 is an underneath pan view of the block of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Referring to FIG. 1 of the accompanying drawing, an embodiment of a multipurpose cutting block 1 of the present invention comprises block part 2 and handle 3 detachably connected to one end of block pat 2 Attached to block part 2 is a second block part 2 ′ which is smaller than block part 2 and, together therewith, provides a rectangular cutting surface extending over both block parts
[0024] The two block parts 2 , 2 ′ are connected together by hinges (not shown) allowing relative pivotable movement therebetween so that movement is possible between the configuration shown in FIG. 1, with a single, contiguous and coplanar cutting surfaces provided, and the configuration shown in FIG. 3 wherein the cutting surfaces, although still contiguous, are arranged at an angle which can typically be from about 20° to 60°.
[0025] Referring to FIG. 4, the block part 2 is provided, on its underside, with a recess 5 for holding a small knife 4 , so that the user may store the knife for use at any time,
[0026] Referring particularly to FIG. 2, handle 3 has associated therewith a block folding mechanism or actuator 3 ′. The handle 6 includes an upper part 61 which is fixed relative to block part 2 . The lower part 7 of handle 6 is in the form of a lever having a handle part extending below handle part 6 ′ and extending there from an arm 7 ′ which is pivotably mounted at fulcrum point ‘a’ provided on a support ‘A’.
[0027] Extending between movable handle part 7 and fixed handled part 6 ′ is a leaf spraying aid which resiliently bias the two handle parts away from each other.
[0028] Lever 7 has, at that end 7 ′ remote form handle part 6 ′, a link to a farther lever 9 which extends laterally therefrom. Lever 9 is mounted for pivotal movement on support ‘B’ about fulcrum point ‘b’ and at its other end, remote from end 7 ′ of lever 7 , lever 9 is provided with an L-shaped finger 9 ′ which extends downwardly from lever 9 and then substantially parallel to handle part 6 ′. At its free end finger engages with block part 2 ′.
[0029] A slot 11 is provided on lever 9 and a locating or positioning pin 10 passes through slot 11 to limit the extent of movement of lever 9 . In particular the lever can move only in an upwards and downward direction and not laterally.
[0030] Referring to FIG. 1 of the accompanying drawings, handle 3 includes a transverse part 6 ′ which, on that side adjacent to block part 2 ′, provides a housing for the above described folding actuator. On the other side of handle part 6 , the transverse part 6 ′ is provided with a notch 12 for sharpening a knife. Furthermore, grinding material 13 is also provided in section of transverse part 6 ′, as shown in FIG. 4.
[0031] When cutting food, the block 1 is in the configuration shown in FIG. 1. If it is then desired to transfer the chopped food into, for instance a bowl or pan, the handle part 6 ′ and 7 are gripped and part 7 is squeezed upwardly towards part 6 ′ against the bias of leaf spring 8 . Accordingly, the end 7 ′ of lever/handle part 7 is caused to move downward and his movement in turn causes lever 9 to pivot about fulcrum point b thereby causing finger 9 ′ to move upwardly and to move block part 2 ′ into the position shown in FIG. 3. As a result the chopped food is collected into the bottom of the V-shape, that is to say, into the area where the two block parts are connected together, so that it can be easily transferred into the bowl or pan.
[0032] Referring to FIG. 4 of the accompanying drawings, the underside of block part 2 is provided with a handle positioning member 14 which is channel-shaped and contains a fastening element 15 connected to the handle 3 . A catch member 16 is provided on both sides of fastening element 15 . When the cutting block is to be cleaned after use, the user can detach the block parts 2 and 2 ′ from the handle by pressing catch members 16 on both sides. By separating the handle from the block parts, the washing of the components is facilitated.
[0033] Referring to FIG. 1 of the accompanying drawings, the upper part of block part 2 is provided with a drain hole 17 adjacent one comer of the block part. Draining groves 18 extend down two sides of the block part 2 and terminate at drain hole 17 . Draining groove 18 and drain hole 17 facilitate the draining of liquid away from the surface of the cutting block during the food chopping operation.
[0034] It would be appreciated that the above described cutting block represents a prefeed embodiment of the present invention. Various modification may be made to this preferred embodiment without departing from the scope of the present invention. | A cutting block includes two block parts pivotably connected together for relative movement between the first position in which the block parts together provide a flat cutting surface, and a second position in which the block parts form, a V-shape facilitating the transfer of food after the cutting operation. The cutting block has a handle extending outward from one of the block parts and actuator being operable to cause the relative movement between the two block parts. | 0 |
BACKGROUND OF THE INVENTION
It is well-known in the art to provide photovoltaic cells for various uses, particularly in generating electricity from solar energy. Such cells are typically quite small and must be electrically connected in larger grids or modules for common electrical applications. The conventional procedure for producing such photovoltaic modules is to coat a portion of both sides of each photovoltaic cell with a conductive metal or metal alloy to form an electrical contact. Electrical wires are subsequently soldered to the electrical contacts of a group of such coated cells in order to form a larger, interconnected cell grid in which the cells are connected in series or parallel relationship. Thick film coatings comprised of (1) silver or silver alloys containing small amounts of glass or (2) aluminum are commonly used as the electrical contacts for photovoltaic cells. In some solar cell production methods, the rear contact of the solar cell is made of aluminum but has "windows" or openings that expose the underlying silicon. Those openings are filled with a silver/glass coating which bonds to the silicon substrate and makes electrical contact with the aluminum coating. The segments of silver coating that fill the windows are known as "soldering pads", since it is far easier and more beneficial to bond copper conductors to the soldering pads than it is to bond them directly to the aluminum layer.
In both manufacturing and in many common applications of photovoltaic modules, the cells are subjected to continuous high temperatures or else to thermal cycles at regular or irregular intervals. For example, in the ethylene vinyl acetate (EVA) lamination procedure that typically follows cell stringing (interconnecting) in the manufacture of multi-cell modules, the cells are subjected to temperatures as high as about 150° C. for about 45-60 minutes. When used in the production of solar energy, the cells will heat up during a cycle of exposure to sunlight and then cool down again to ambient temperatures at night. In other applications, the heating and cooling cycles may be much more frequent. Accordingly, an important characteristic of such cells is their ability to withstand thermal aging, particularly with respect to their solder connections.
Prior art photovoltaic cells incorporating silver thick film electrical contacts or solder pads and conventional electrical solders applied by conventional dip or wave soldering techniques commonly show poor mechanical reliability of their solder bonds when subjected to thermal aging. Specifically, the strength of bonds made to silver/glass thick films on silicon using 63% tin/37% lead or 62% tin/36% lead/2% silver solders degrades by more than 80% upon exposure to temperatures of 150° C. for one hour. Since exposure to such temperatures for such periods of time is typically required to bond the cells to glass to manufacture photovoltaic modules, the bonds in modules made with such solders are inherently weak. It is expected that further degradation in bond strength will continue at normal operating temperatures of photovoltaic modules. Stress testing of modules made in this manner indicate that their performance degrades relatively rapidly under conditions that produce mechanical loading on the module, including changes in temperature which can be expected to occur in typical applications.
The problem of thermal degradation of soldered thick film silver-bearing conductors in semiconductor devices has been reported and discussed in the literature. For example, in "Progress in and Technology of Low Cost Silver Containing Thick Film Conductors", by B. E. Taylor, J. J. Felten, and J. R. Larry, in Proceedings of the 30th Electronic Components Conference, New York, IEEE, 1980, pp. 149-166, the authors reported that such degradation on miniaturized and hybrid circuits on ceramic substrates can be reduced, in the case of silver/palladium thick films, by the use of 95% tin/5% silver solders instead of conventional tin/lead solders. But, because this solder has a particularly high melting point, its tin component tends to dissolve silver from the thick film during bond formation Accordingly, this procedure would not be useful for soldering thick films consisting of primarily silver, which are considerably less expensive than the silver/palladium thick films of the reference.
In a more recent reference, "The Thermal-Cycled Adhesion Strength of Soldered Thick Film Silver-Bearing Conductors", by C. R. S. Needes and J. P. Brown, in Proceedings of ISHM '89, ISHM, 1989, pp. 211-219, the authors concluded (at p. 215): "For the silver conductor, the best [thermal]results were obtained with [a solder of]10 Sn/88 Pb/2 Ag." FIG. VII at p. 215 of the ISHM reference clearly shows that, with silver thick films on alumina substrates, a solder comprising 10% tin, 88% lead and 2% silver demonstrated superior thermal-cycled adhesion strength as compared with a solder of 96% tin and 4% silver. The 96 Sn/4 Ag solder began to show a marked deterioration after fewer than 200 thermal cycles, whereas solder bonds prepared using the 10 Sn/88 Pb/2 Ag solder did not show significant deterioration until approximately 500-600 thermal cycles. Both of the foregoing references are incorporated herein by reference.
The literature in this field thus teaches away from the use of tin/silver solders containing predominant proportions of tin on silver or silver alloy thick film contacts or soldering pads for photovoltaic cells. The literature suggests that the problem may be caused, at least in part, by the tendency of the tin/silver solder to cause "leaching" or "scavenging" of silver, i.e. the dissolution of the silver thick film in the molten solder at elevated temperatures. The relatively high cost of silver as well as technical considerations make it impractical or uneconomical to use thicker silver films or solder with higher proportions of silver to try to overcome the leaching problem. As noted above, silver/palladium thick films are even more expensive than using silver alone. Moreover, the toxicity of lead limits the utility of the tin/lead/silver solders touted by the Needes and Brown reference cited above.
The literature in this field also suggests that the problem of thermal instability may be caused, at least in part, by the formation of intermetallic compounds between tin and silver because such compounds are known to be brittle and weak. These compounds can form not only while the solder is molten, but any time the solder is at an elevated temperature. Some formation of these compounds occurs slowly even at room temperature. It has been suggested that these intermetallic compounds are the result of tin from the solder diffusing through the glass and metal surface phases. These compounds, being brittle, cause the metallization to feral at low stress levels.
It is possible, of course, that both the silver scavenging and intermetallic compound mechanisms are involved in the thermal instability problem. This makes a solution to the problem even more difficult to predict because a solution to one of these mechanism may exacerbate the other.
For example, one researcher reported reducing the problem of intermetallic compound formation by using a high tin-bearing solder, such as 96% tin/4% silver. The explanation was that a 96 Sn/4 Ag solder has a melting point significantly higher than a solder consisting of 62 % tin, 36% lead, and 2% silver, resulting in bonding the tin more strongly to the solder and thereby reducing diffusion. On the other hand, data reported in the Needes and Brown reference cited above suggest that the high tin content and high melting point of a 96 Sn/4 Ag solder may lead to increased thermal degradation of solder bonds due to the silver scavenging mechanism. Accordingly, the prior art provides no clear solution to the problem of thermal aging of solder bonds to silver metallized photovoltaic cells.
These and other drawbacks of the prior art are overcome with the present invention.
OBJECTIVES OF THE INVENTION
It is a principal object of this invention to provide photovoltaic cells having superior thermal aging properties.
It is also an object of this invention to provide photovoltaic cells with silver thick films which are electrically interconnected using a tin/silver solder and which demonstrate superior resistance to thermal degradation.
A further object of this invention is to provide a method of soldering the silver thick film contacts of photovoltaic cells using a tin/silver solder without causing deterioration of the thick film-substrate bonds.
Still another object of this invention is to provide economical and high-performance banks of interconnected photovoltaic cells having special application in the production of electricity from solar energy.
These and other objects and advantages of this invention will be apparent from the following description.
DETAILED DESCRIPTION OF THE INVENTION
It has now been discovered that photovoltaic cells with silver or silver alloy thick film electrode or soldering pad coatings can be interconnected using tin/silver solders in a way that results in surprisingly superior thermal aging properties. The solders that are useful in this invention are combinations of tin and silver ranging from about 96% tin/4% silver to about 98% tin/2% silver applied to the silver thick films in the form of a solder paste incorporating compatible, volatile fluxing agents.
Solder pastes comprising relatively large amounts of tin and relatively small amounts of silver are well-known in the art and are commercially available from several manufacturers. For example, "96 tin/4 silver Xersin 2005" is a solder paste comprising approximately 96% tin and 4% silver in a synthetic flux, manufactured by Multicore Corp. having U.S. offices in Westbury, New York. In general, the solder pastes useful in conjunction with this invention are homogeneous stable blends of pre-alloyed solder powder and flux. They usually incorporate a special flux or gelling additive to prevent the solder powder from settling.
The solder pastes used in practicing this invention have a creamy, paste-like consistency and are available ready for use in a wide range of combinations of solder alloy, flux, particle shape, particle size, flux content and viscosity. The literature in the field notes that these solder pastes are increasingly finding applications in soldering of surface mounted devices to hybrid circuits and printed circuit boards. A Multicore Corp. product bulletin entitled "Solder Cream", in describing its line of solder pastes, indicates that a 96.3 Sn/3.7 Ag solder paste has particular application where higher melting point lead-free joints are required There appears to be no recognition in the literature, however, of the special utility of such solder pastes in connecting conductors to contacts or soldering pads of photovoltaic cells that are in the form of silver or silver alloy thick films.
The literature in the field also recognizes a variety of natural and synthetic fluxing agents that are compatible with the solder pastes and designed to keep the solder powder in suspension. The Multicore Corp. product bulletin referred to above, for example, lists eleven types of fluxing agents that can be used to formulate its solder pastes. A synthetic flux sold under the trade name "Xersin 2005", recommended in the Multicore Corp. bulletin for very high reliability applications, and a mildly activated rosin flux (RMA), recommended for military and professional electronics applications, have been found to demonstrate superior thermal aging properties when used in accordance with this invention. Xersin has the advantage of leaving no corrosive residue behind after bonding, but it does not promote particularly good wetting of the silver by 96% Sn solder. On the other hand, the Multicore Corp. bulletin notes that RMA flux promotes excellent wetting, but contains some ionic ingredients which will remain behind on the cell. However, the choice of fluxing agent is not considered critical for this invention. Any recognized natural or synthetic fluxing agent compatible with a tin/silver solder paste is intended to be within the scope of this invention.
For a better understanding of the present invention, the following examples are presented. These examples are intended only as representative embodiments of this invention and should in no way be construed as limiting the field or scope of this invention.
EXAMPLE 1
Photovoltaic silicon cells were provided that had a rear contact comprising an aluminum layer covering the silicon substrate, with the aluminum layer having windows that were filled with silver/glass solder pads in direct contact with the underlying silicon. The solar cells also had a silicon nitride anti-reflection (AR) coating on their front surfaces, and a front grid-shaped contact comprising a silver/glass composition that penetrated the AR coating and was fused to the front surfaces so as to make an ohmic contact therewith. The silver soldering pads and the front grid-shaped silver contacts were thick films having a thickness of about 17-20 microns. The silver front grid contacts and the silver rear soldering pads of each cell were electrically interconnected to other like cells with copper ribbon using "96 tin/4 silver Xersin 2005" solder paste manufactured by Multicore Corp, so as to form multi-cell modules. The solder paste was deposited at ambient temperature, i.e., 25 degrees C, on each silver thick film using a syringe as a paste dispenser It is to be noted that in commercial production, the solder paste would be deposited on the cells mechanically using automated dispensers such as the "CAM/ALOT" dispensing system manufactured by Camelot Systems, Inc. located in Haverhill, Massachusetts. To effect soldering, the paste was then heated in situ by the use of resistance heating electrodes or jets of hot air. During the heating process, the "Xersin 2005" fluxing agent, which is believed to be primarily pentaerythritoltetrabenzoate ("Pentoate"), was driven off and the metallic components of the solder were fused to the silver films and the copper conductors. Multi-cell modules prepared in the manner described above were used in the following test comparisons.
EXAMPLE 2
Modules comprising silver thick film photovoltaic cells prepared in the manner described in Example 1 were compared with similar modules prepared using conventional dip-soldering techniques and a solder bath comprising approximately 96% tin/4% silver. The initial bond strength at the cell contact points for modules prepared according to this invention (Example 1) averaged 1.68 lb., whereas the average bond strength for modules prepared using dip-soldering was only 0.48 lb. This example demonstrates that, even before being subjected to aging or additional thermal stress, photovoltaic cell modules prepared in accordance with this invention showed superior bonding strength at the electrical contact points to modules prepared using the same general solder composition applied by conventional dip-soldering.
EXAMPLE 3
In this example, the stability of modules prepared in the manner described in Example 1 were compared over time and at elevated temperatures with similar modules that had been prepared using (a) conventional dip-techniques and (b) a solder bath comprising approximately 96% tin/4% silver to interconnect the several cells making up the modules. Testing of the modules prepared according to Example 1 showed substantially no degradation of the solder bonds at the cell contact points after 45 minutes at 150° C.
With these encouraging results, the testing of the modules prepared according to Example 1 was extended at 150° C. to 63 hours This test would be equivalent to 30 years at projected operating conditions, if a standard (and simplistic) assumption were correct that the rate of degradation doubles for every 10° C. rise in temperature. The test showed no significant degradation occurring until near the end of the test period. At the end of the test, 100% of the bonds were still over 0.25 lb., with an average of 0.70 lb. When the test period was more than doubled to 135 hours, 89% of the bonds still passed our criterion for initial peel strength.
By contrast, when modules prepared using the conventional dip-soldering techniques and a 96% tin/4% silver solder bath were subjected to the same test, bond yield was stable at the beginning of the test, but dropped to only 3% after 16 hours at 150° C. This example demonstrates the surprising and completely unexpected superior thermal stability of photovoltaic cell modules prepared in accordance with this invention compared to prior art modules.
Based on these and other tests, we conclude that photovoltaic cell modules prepared using the solder paste compositions of this invention will maintain their bond strength at a temperature of about 150° C. as much as 200 times longer than modules prepared using conventional dip-soldering techniques and solder baths comprising approximately 96% tin/4% silver.
We have also explored the range of compositions providing best maintenance of bond strength in this application, and have found it to be relatively narrow. Based on these observations, we believe that optimum performance will be found for solder compositions between 96% tin/4% silver and 98% tin/2% silver.
As used herein, the term "silver contact(s)" means and includes an entire electrode or electrodes on the rear and front sides of a solar cell, and also those members which function as soldering pads for contacts made of another metal. Thus, for example, the term "silver contact(s)" includes a silver/glass frit grid-shaped front contact and the silver soldering pads that are associated with and fill the windows of an aluminum rear solar cell contact. Also the terms "silver film" and "silver coating" mean a film or coating that consists entirely or primarily of silver. Those terms are to be construed to embrace a film that is characterized by 90-100 wt. % silver and 0-10 wt. % aluminum and/or nickel.
It should be understood that the foregoing description of the invention is intended merely to be illustrative and that the other embodiments and modifications may be apparent to those skilled in the art without departing from its spirit. | Photovoltaic cells with silver-rich thick film electrical contacts and superior thermal aging properties are disclosed. Electrical wires are bonded to the silver-rich thick film contacts using a tin and silver solder paste comprising between about 96% tin/4% silver and 98% tin/2% silver. Solar cells having soldered connections incorporating the present invention exhibit the capabilty of withstanding temperatures in the range of 150° C. with little or no deterioration of the solder bonds for periods far longer than conventionally prepared cells. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application relates to and claims priority to U.S. Provisional Patent Application No. 61/287,510 filed on Dec. 17, 2010, and incorporates this application by reference in their entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
BACKGROUND OF THE DISCLOSURE
[0003] As described in my above-noted U.S. patent application Ser. No. 12/576,923, which is herein incorporated by referent in its entirety, a shear blade 189 (referring to the reference characters in the aforesaid patent application and in FIG. 1 of the present disclosure), preferably a carbide blade, has an elongate sharp shear edge 191 . The shear blade is removably mounted in a recess 199 in a shear blade carrier 185 and is held in place by bolts (not shown in FIG. 1 ) received in openings 195 , 197 . The shear blade edge 191 is exceedingly sharp. However, after shearing thousands or even tens of thousands of books, the cutting edge may become dull and would require replacement. Because access to the bolts holding the blade in place was from below, it was difficult for a technician to access these bolts to effect changing of the blade. In addition, the sharpness of the shear edge 191 , posed a safety problem for the technician as he removed the blade from the book shear. Thus, there was a need to provide easier access to the bolts securing of the blade to the blade carriage and there was a need to protect the technician from the sharp edge both during both installation of a new blade and removal of a used blade.
SUMMARY OF THE DISCLOSURE
[0004] A replaceable shear blade for a book trimming apparatus is disclosed. The book trimming apparatus comprises a shear carriage having the replaceable shear blade mounted thereon. The shear blade has a sharp cutting edge for shearing a book between an anvil and the cutting edge. The shear blade is removably mounted with respect to the shear carriage for replacement of the shear blade by a plurality of fasteners accessible from above. A removable sheath encloses the cutting edge. At least one removable handle is secured to the shear blade so that the shear blade and the sheath may be handled as a unit, with this handle being grippable from above the shear carriage for installation of the shear blade on the shear carriage, and with the handle and the sheath being removable from the shear blade upon installation of the shear blade on the shear carriage.
[0005] A method of installing a shear blade in a book shear is disclosed. This method involves fitting a sheath around a cutting edge of the shear blade so as to protect the cutting edge during installation. Then, the shear blade is installed in a recess in a shear carriage such that a rear face of the shear blade is in engagement with a rear shoulder of the shear carriage. The shear blade body is secured to the shear carriage by means of a plurality of fasteners accessible from above. Then, the sheath is removed from the shear blade.
[0006] Other objects and features of the disclosure will be in part apparent and in part pointed out hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a view similar to FIG. 17 of U.S. patent application Ser. No. 12/576,923 illustrating a shear blade installed in a shear assembly for trimming a perfect bound book between the shear blade and an anvil;
[0008] FIG. 2 is a perspective top view of a book shear assembly similar to the shear assembly shown in FIG. 1 illustrating the system for the installation and removal of the shear blade while the cutting edge of the shear blade is enclosed in a sheath to protect the technician changing the blade and to protect the blade, and illustrating that the fasteners holding the blade are accessible from above;
[0009] FIG. 3A is a vertical sectional view taken along line 3 - 3 of FIG. 2 illustrating the system for the installation and removal of the shear blade while the cutting edge of the shear blade is enclosed in a sheath to protect the cutting edge and the technician changing the blade and illustrating that the fasteners holding the blade are accessible from above;
[0010] FIG. 3B is a view similar to FIG. 3A illustrating in cross section an eccentric adjustment fastener installed in the replaceable blade body for aiding in positioning the blade body and the blade carried thereby relative to the blade carrier and relative to the anvil against which the book it to be sheared;
[0011] FIG. 4 is an exploded perspective view on an enlarged scale of the replaceable shear blade and its sheath; and
[0012] FIG. 5 is a cross sectional view of an eccentric adjustment fastener installed in an eccentric hole in the replaceable blade body for aiding in positioning the replaceable blade.
[0013] Corresponding reference characters indicate corresponding parts throughout the several views of the drawing.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0014] Referring now to the drawings and particularly to FIG. 1 , a book trimming station is indicated in its entirety by reference character 61 . This book trimming station is similar to the book trimming station disclosed in the above-discussed U.S. patent application Ser. No. 12/576,923, filed on Oct. 9, 2009, which is herein incorporated by reference in its entirety. Reference should be made to this '923 application for a full description of the trimming station 61 . In this disclosure, some of the more salient features of the trimming station will be disclosed in order to specifically describe certain features that may be important to the understanding of the present disclosure. However, reference nevertheless should be made to the above-noted '923 application for a more complete description. It will be understood that reference characters below number 500 refer to structure described in the above-noted '923 U.S. patent application and that reference characters above 500 refer to newly disclosed subject matter described herein. However, it will be understood that the subject matter described in the above-noted '923 application is not prior art with respect to the instant application just because it was first disclosed in the above-noted application.
[0015] As shown in FIG. 2 , trimming station 61 includes a book clamp 135 and a book shear 137 mounted on a frame bed 133 . The book clamp 135 clamps a book B, as shown in FIG. 15 of the above identified application, between a stationary, fixed anvil 139 and a movable clamp member 155 by means of clamp motor 145 and its drive. The details of the clamp drive and motor are fully disclosed in the above-noted patent application. Further, shear 137 includes a shear carriage 185 mounting a shear blade 189 . The shear carriage and shear blade are movable by a shear motor 175 and its associated drive between a retracted position in which the cutting edge 191 of shear blade 189 is clear of a book clamped on anvil 139 by book clamp 135 and a shearing position in which the shear blade shears through such book.
[0016] Blade 189 is preferably a carbide blade having a sharp shearing or cutting edge 191 . In order to shear books, this shearing edge must be exceedingly sharp. Because the preferred blade is a carbide blade, it remains sharp so that it may shear thousands and perhaps tens of thousands of books. However, the cutting edge will eventually become dull and need to be changed. The number of books that blade 189 may shear before its cutting edge 191 dulls is somewhat dependent on the paper used for the book block and the covers of the books being printed and sheared. It will be understood that some paper stocks may be somewhat more abrasive than other papers and that the more abrasive papers may cause more wear on the blade. Also, such carbide blades are fragile and may be subject to breakage or nicking of the cutting edge for a variety of reasons. Accordingly, it may be necessary to change blade 189 from time to time so as to insure that the shear 137 satisfactorily shears the books.
[0017] As shown in FIG. 17 of in the above-noted patent application, the shear blade 189 is removably secured to the shear blade assembly 187 by bolts (not shown in FIG. 17). The shear blade assembly 187 has a plurality (e. g., four) of elongate slots 195 that extend generally perpendicular to blade edge 191 . These elongate slots in the blade assembly cooperate with mating elongate slots 197 in the blade carrier 185 and receive bolts (not shown). These elongate slots and the bolts permit the shear blade assembly 187 to be precisely positioned within the shear blade carrier 185 so that the cutting edge 191 of blade 189 uniformly contacts the book along the width of the book side to be sheared. The blade is firmly held in place relative to blade carrier 185 when the bolts (again, not shown in FIG. 17 of the above-noted application) in slots 195 , 197 are tightened. However, it was necessary for the technician changing the blade to access these bolts from below to loosen these bolts so that an old blade may be removed. It was also necessary for the technician to access these bolts from below to tighten these bolts upon the installation of a new blade. This either required two technicians to change the blade or required a technician positioned below the blade carriage to reach between the anvil and the cutting edge 191 of blade 189 to access the bolts. This exposed cutting edge posed a hazard to the technician both on installing and removing the blade. In addition, because the preferred blade 189 was a carbide blade, it was subject to breaking or nicking upon installation.
[0018] In accordance with the present disclosure, an improved blade installation and removal procedure is disclosed in which the bolts 502 securing the blade in place on the blade carriage 185 are accessible from above and in which the cutting edge 191 of the blade 189 is protected within a sheath S, as shown in FIGS. 2-4 , as the blade assembly is installed or removed. This sheath S is preferably made of a suitable plastic material, such as High Density Polyethylene (HDPE), or other suitable plastic or other frangible.
[0019] Referring to FIG. 4 , a replaceable shear blade assembly, as generally indicated at 501 , is shown. This replaceable shear blade assembly comprises a blade body 503 , preferably of a suitable carbon steel material or the like, to which a carbide blade insert 505 is adhered by a suitable adhesive as is well known in the art. Preferably, blade insert 505 is of a suitable carbide material, such as a tungsten carbide material commercially available from Alliance Knife Co. of Germany, which is inlaid or bonded to the carbon steel blade body 503 . Blade insert 505 has a sharp cutting edge 507 facing forward toward anvil 139 . As shown best in FIG. 4 , blade insert 505 has a flat, planar top horizontal surface 509 that is generally co-planar with the top surface 511 of blade body 503 when the blade body is installed in blade carriage 185 . Further, blade insert 507 and blade body 503 have a wedge-shaped or inclined lower surface 513 angling upwardly toward cutting edge 507 to form the cutting edge. It will be understood that as cutting edge 507 shears through a book B held between the clamp member 155 and anvil 139 , this angled lower surface pushes the sheared margin of the book downwardly away from the underside of the blade insert and the blade body.
[0020] As previously noted, the cutting edge 507 of blade insert 505 is preferably enclosed or protected by a plastic sheath S, as shown in FIGS. 2-4 . This sheath S has an upper surface 515 , a front, vertical portion 517 disposed in front of cutting edge 507 , and a lower portion 519 underlying the blade insert so that the full length of the cutting edge is enclosed within the sheath. It will be appreciated that the lower portion 519 of the sheath may be formed so as to resiliently grip the lower surface 513 of the blade body 503 so as to aid in holding the sheath in its protective position as the blade is shipped and as the blade is handled at the installation site.
[0021] As indicated at 521 in FIG. 4 , the upper surface 515 of sheath S has a pair of spaced holes therein for receiving a threaded stud 523 protruding from a respective handle 525 , where the stud is received in a respective threaded hole 527 in the upper face of blade body 503 so as to secure the handles to the blade body and to hold the sheath in position on blade assembly 501 . Handles 525 allow the technician to readily handle the replaceable blade (which may weigh several pounds) during installation and removal of the blade from the blade carriage, and the technician is protected from the sharp cutting edge 507 by the sheath S.
[0022] Blade body 503 has a plurality of circular bolt holes 529 (five such bolt holes are shown) in the rear portion of the blade body. These bolt holes 529 are aligned with threaded bolt holes 531 in blade mounting body 203 , which is similar to body 203 described in the afore-mentioned '923 application. The bolt holes 529 are preferably countersunk so that when bolts or fasteners 533 (as shown in FIG. 3 ) are inserted from above the heads of the bolts are below the upper surface of the blade body. The shanks of these fasteners threadably engage their respective threaded hole 531 in blade mounting body 203 . As shown in FIG. 3 . In addition, two spaced eccentric holes 537 are provided in blade body 503 for receiving a respective eccentric, adjustable fastener, as generally indicated at 539 .
[0023] Blade body 503 is received in a recess 541 provided in blade mounting body 203 . It will be understood that the eccentric fasteners 539 may be used to accurately position the blade assembly 501 within recess 541 so that a rear edge 543 of blade body 503 is in abutting relation with a forward facing shoulder 545 of recess 541 in blade mounting body 203 , as shown in FIG. 3 . It will be understood that rear edge 543 is parallel to the shear surface of anvil 139 such that when rear edge 543 is in abutting relation with shoulder 545 , cutting edge 507 is substantially parallel to the cutting surface of anvil 139 . However, it may be desired to use the adjustable eccentric fasteners 539 to precisely adjust the blade edge 507 to be parallel to the cutting surface or cutting stick 217 of anvil 139 . With the blade body 503 so positioned in recess 541 , bolts 533 are tightened, the blade assembly 501 is secured in position relative to body 203 .
[0024] In accordance with the present disclosure, in order to install blade assembly 501 in shear carriage 185 , the clamp jaw 155 is moved to a retracted position clear of anvil 139 and shear carriage 185 is advanced to approximately its position shown in FIG. 2 or 3 such that the blade assembly 501 is clear from above. Assuming that no blade assembly is installed on blade carriage 185 , the new blade assembly is removed from its shipping container (not shown). Preferably, sheath S is shipped with each new blade assembly and the sheath is installed over the cutting edge 507 of blade insert 505 so as to protect the blade during shipping. While handles 525 may be shipped installed on the blade assembly, it may be preferable that the handles are removed from the new blade assembly within its shipping container or box. If that is the case, before the blade assembly is removed from its shipping container, the handles 525 are installed by inserting handle studs 523 (which are preferably installed on the handles) through holes 521 in sheath S and are threadably engaged in holes 527 in blade body 503 . With the handles 525 so installed, sheath S is fixedly held in place on blade assembly 501 in such manner that it cannot be inadvertently dislodged from the blade insert 505 during installation of the blade assembly. In this manner, cutting edge 507 remains covered during installation of the blade until the sheath S is removed. It will be further appreciated that the handles 525 allow the technician to readily hold the blade assembly as it is positioned within recess 541 in blade mounting body 203 .
[0025] As previously noted, eccentric fasteners 539 are inserted in eccentric holes 537 in blade mounting body 203 so as to insure that blade body 503 is properly positioned within recess 541 with its rear wall 543 in firm engagement with shoulder 545 of the blade mounting body 203 . As noted, this insures that cutting edge 507 is parallel to the cutting surface of anvil 139 . In addition, recess 541 may be provided with side walls 547 of recess 541 (as shown in FIG. 2 ) which abut corresponding side walls 549 (see FIG. 4 ) of blade mounting body 203 so as to effectively prevent side-to-side shifting or movement of blade assembly 501 with respect to the blade mounting body 203 .
[0026] Once blade assembly 501 has been so installed on blade carriage 185 (and more precisely has been installed in recess 541 of blade mounting body 203 ), handles 525 may be unscrewed so as to remove the handles and their respective studs 523 from blade mounting body 503 . Then, sheath S may be slipped off blade insert 505 so as to expose cutting edge 507 and the sheath is removed from the trimming station. Alternatively, sheath S may remain in place and the shear carriage 185 may be extended toward anvil 139 so that the cutting edge 507 may forcefully shear the front, vertical portion 517 of the sheath between the cutting edge and the anvil so that a portion of the sheath below a shear line approximately halfway down the sheath portion 517 so that the sheared portion will drop into the waste chute of the book trimming station 61 . Then, as the shear carriage is moved toward its retracted position, the rear edge of the top portion 515 of sheath S will engage the clamp surface 170 of clamp bar 155 . Because the sheath is no longer held in position by handles 525 , this retraction of the shear carriage will sweep the remaining upper portion 515 of the sheath from the blade assembly and this upper portion will also be discarded into the waste chute. In this manner, the cutting edge 507 is not exposed at any time during the installation of the blade assembly 501 .
[0027] In order to remove the blade assembly 501 , the above-described process is reversed. Specifically, to remove the blade assembly the clamp bar 155 is moved to a retracted position, such as shown in FIG. 2 so that the blade assembly and the fasteners 529 and 539 are accessible from above. Then, a new sheath S is positioned around the cutting edge 507 , as shown in FIG. 3 , and handles 525 are installed so that the handle studs 523 are inserted through holes 521 in the upper portion 515 of the sheath and are threadably engaged in holes 527 in the blade mounting body 503 . Then fasteners 529 and 539 may be then removed from above and the entire blade assembly and the sheath may be removed from the shear carriage from above as a unit. Again, except during installation of sheath S on cutting edge 507 , the cutting edge is enclosed by and protected by the sheath during removal of the blade assembly.
[0028] As indicated at 209 in FIG. 3 , the rear edge of mounting body 203 is in camming engagement with cam 209 so that the position of cutting edge 507 of blade assembly 501 may be accurately adjusted toward and away from anvil 139 . As described in the afore-mentioned '923 application, cam 209 may be adjusted by means of a cam actuation screw 215 .
[0029] As various changes could be made in the above constructions without departing from the broad scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. | A replaceable shear blade for a book trimming apparatus, the latter comprising a shear carriage having the replaceable shear blade mounted thereon. The shear blade has a sharp cutting edge for shearing a book between an anvil and the cutting edge. The shear blade is removably mounted with respect to the shear carriage for replacement of the shear blade, where the shear blade is removably secured relative to the shear carriage by a plurality of fasteners accessible from above. A removable sheath encloses the cutting edge. At least one removable handle is secured to the shear blade so that the shear blade and the sheath may be handled as a unit, with this handle being grippable from above for installation of the shear blade on the shear carriage, and with the handle and the sheath being removable from the shear blade upon installation of the shear blade on the shear carriage. A method of installation and removal of the shear blade is also disclosed. | 8 |
This application is a continuation of application Ser. No. 07/644,118, filed Jan. 18, 1991, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a method of coating a resin solution which is hardened by polymerization.
Conventionally, the slide hopper-type, the extruder-type and the Giesser-type coating apparatus, each equipped with a liquid-spouting slit and/or a liquid-releasing edge, have been employed for the continuous application of a coating liquid onto the surface of a support web. However, the use of these apparatus encounters such a problem that a coating liquid may adhere to the periphery of the liquid-spouting slit and/or the liquid-releasing edge due to its stagnation, wetting and creeping back flow when continuously applied onto the surface of a support web, and solidify there with the lapse of time. When a coating liquid comprises a hardenable resin, this phenomenon causes serious coating streak trouble, and eventually leads to significantly lowered productivity and poor product quality.
The adhering coating liquid, which is hardened by polymerization, is too hard to be removed by washing with water or wiping off with a solvent. Shaving-off with a knife is the only effective way to remove it, but, to avoid a risk that a coating apparatus which is shaped precisely gets scratches, such shaving must be done carefully taking a long period of time.
The coating of a resin solution which is hardened by polymerization is always accompanied by coating streak trouble, that is of a cause entirely different from a similar comet-like longitudinal streak trouble which is caused by the slower flow of solid particles when an ununiform coating liquid obtained by suspending the solid particles is applied. This trouble cannot be avoided by adjusting coating conditions such as the viscosity of a coating liquid or by controlling the fluctuations of a web.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a method of preventing the adhesion of a stuck solid resin to the periphery of a liquid-spouting slit and/or a liquid-releasing edge of the coating head in the continuous application of a resin solution that is adjusted to be hardenable by the addition of a polymerization inducer, such as a polymerization catalyst, a polymerization initiator and a cross-linking agent, which stuck solid resin is formed by the solidification of said resin solution.
Another object of the invention is to provide a technique for avoiding longitudinal streak trouble in a coating layer of said resin solution.
The above objects can be achieved by the following method that is, when at least one layer is provided on a support by preparing a uniform solution of a resin which is polymerized to solidify by the action of a polymerization inducer, which serves to activate a polymerization system prior to polymerization, coating a solvent film layer is performed on the upper surface of the coating film layer of said uniform solution, which is adjusted to be hardenable, and coating a film layer of a resin solution which is adjusted to be unhardenable on the lower surface of the coating film layer of said hardenable resin solution, according to a multiple casting process.
In the invention, the expression "adjusted to be unhardenable" means such a condition that a polymerization inducer does not take effect, and more specifically, means the absence of a polymerization inducer, or, in the case of a composite polymerization inducer which will be explained later, means the absence of one or all of elemental polymerization inducer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates one embodiment of the present invention in which a multi-layer coating is performed with a slide hopper type coater;
FIG. 2 illustrate another embodiment of the present invention in which a multi-layer coating is performed with an extruder type coater; and
FIGS. 3 and 4 respectively illustrate the conventional coating process of a slide hopper type and an extruder type, showing the formation process of a stuck resin solid.
DETAILED DESCRIPTION OF THE INVENTION
Generally, polymerization can be classified into radical (free radical) polymerization and ion polymerization (cation and anion polymerization) in respect of the dynamics of polymerization, and into addition polymerization, copolymerization and condensation polymerization with respect to the manner of polymerization.
Polymers obtained by polymerization can be divided into unidimensional chain-like or branched polymers and three-dimensional cross-linked (net-like) polymers in regard to the shape of molecules.
The three-dimensional cross-linked polymers can be divided into net-like polymers in which the molecules of unidimensional polymers are directly linked to each other at their active sites and cross-linked polymers in which a bridging molecule chain is present between the molecules of unidimensional polymers.
Various agents are employed in a polymerization system that will produce a polymer (resin) with a prescribed shape by the above-mentioned polymerization dynamics or in the above-mentioned manner of polymerization.
Such agents include polymerization catalysts which serve to activate a polymerization system and put it in polymerization mechanism without being consumed in a normal state; polymerization (chain reaction) initiators which serve to allow polymerization to proceed with themselves being consumed and decomposed into radicals; and polymerization promoters which serve to promote the decomposition of initiators into radicals with themselves being consumed. The polymerization initiators and promoters, which are consumed during polymerization, and are occasionally taken into a resin formed, should be distinguished from the polymerization catalysts.
The mechanism of these agents in radical, cation or anion polymerization has not yet been fully elucidated. Further, it is hard to draw an exact line among these agents in view of various conflicting viewpoints as to the activity of these agents and the ambiguity of terminology, in addition to the fact that there are cases where polymerization initiates and proceeds by the action of at least two of these agents compensating for one another.
Therefore, in the invention, such agents as polymerization catalysts, polymerization (chain reaction) initiators and polymerization promoters will be referred to as "polymerization inducer" and a group of two or more of these agents which is involved in polymerization by their combined effects will be referred to as a "composite polymerization inducer" for convenience sake.
In contrast to the preceding polymerization inducer, there are agents that suppress polymerization, such as polymerization inhibitors that retard a reaction; polymerization prohibitors that prevent a reaction from initiating for a while (induction period) and then allow the reaction to proceed as they are consumed; and polymerization regulators that control the molecular weight of a polymer without changing the velocity of polymerization.
"Cross-linking agents" generally mean agents that form a bridging molecule between the molecules of a chain-like polymer. In the present invention, such cross-linking agents, as well as agents that directly link the molecules of a chain-like polymer to form a net-like polymer, will be included in the preceding polymerization inducers.
Usable cross-linking agents include divinyl compounds, diallyl compounds that are employed for the polymerization of vinyl monomers under the mechanism of radical polymerization; aldehydes, dialdehydes, urea derivatives, glycols, dicarboxylic acids, monoamines and diamines which permit the condensation cross-linkage reaction of the polymers having active hydrogen such as hydroxyl, amino and carboxyl radicals under the mechanism of ion polymerization; and diisocyanates, bisepoxy compounds and bisethylene imine compounds which permit the cross-linkage of the above polymers in a manner of the addition polymerization.
The present invention is aimed at eliminating coating trouble ascribable to the hardening of a resin solution which is caused with the lapse of time by the action of the aforementioned polymerization inducer.
The coating apparatus to be employed in the invention include Giessers, extruders, slide hoppers and curtain flow-type apparatus.
FIG. 3 shows the conventional manner of multi-layer coating by means of a slide hopper.
Numeral 1 designates a hopper, 11 a liquid-spouting slit, 12 a liquid-releasing edge, 13 a ridge to prevent the overflow of a coating liquid, 14 a liquid-extruding pump, 2 a hardenable resin solution, 21 a coating film layer running down the slide surface, 3 a backing roll, 4 a support web backed by the roll, and 41 a coated layer formed on the web.
"A" designates a resin solid stuck at the bead forming part of the edge 12, which is formed by the hardening of the resin solution. "B" also designates a resin solid stuck at the ridge 13. In the case of "B", the resin solution climbs up the ridge 13 while wetting the ridge, and solidifies there with the lapse of time. In a slide hopper type coating, both sides of a coating film layer are subject to cause longitudinal streak trouble, and the longitudinal streaks formed by "B" can hardly be cured by self-restoration.
FIG. 4 illustrates the conventional manner of coating by means of an extruder.
Numeral 5 designates an extruder head, 51 a liquid-spouting slit, 52 a edge at the up stream side, 53 a edge at the down stream side, 61 a bead formed between a support web and the end of the extruder head, 3 a backing roll, 4 a support web backed up by the roll 3, and 41 a coated layer formed on the web.
"C" designates a resin solid stuck at the bead portion of the edge 52, which is extruded from the hardening of the resin solution. "D" also designates a resin solid stuck at the liquid-releasing point of the read edge 53 in the bead portion. Like a slide hopper, both sides of a coating film layer formed by an extruder head are also subject to cause longitudinal streak trouble. Further, since the stuck resin solid is formed in a small opening between the end of the extruder and the web, the formation of a large stuck resin solid may not only cause the longitudinal streak trouble, but also may do damage to the support web.
To solve the above problem, in the present invention, the upper and lower sides of a coating film layer of a resin solution which is adjusted to be hardenable by the addition of a polymerization inducer are respectively brought into contact with a coating film layer of a solvent and that of a resin solution which is adjusted to be unhardenable, so that said hardenable resin solution is prevented from touching a liquid-releasing edge and/or a ridge where said hardenable resin solution tends to adhere and solidify with the lapse of time.
FIG. 1 shows one embodiment of the present invention in which a slide hopper type coater is employed. In FIGS. 1 and 3, the same numeral has the same meaning.
In FIG. 1, numeral 2 designates a resin solution adjusted to be hardenable, 21 a coating film layer running down the slide surface, 2 a solvent, 2 a resin solution adjusted to be unhardenable, 21 a coating film layer of 2 in contact with the upper surface of 21, 21 a coating film layer of 2 in contact with the lower surface of 21, and (41) a coated layer having multi-layer formed on a web 4 and consisting of coating film layers 21, 21 and 21.
FIG. 2 shows another embodiment of the invention in which an extruder is employed.
Numeral 61 is a bead of a resin solution adjusted to be hardenable, 61 a bead of a solvent 2 in contact with the upper side of the bead 61, 61 a bead of a resin solution 2 adjusted to be unhardenable being in contact with the lower side of the bead 61.
A coating film layer of the hardenable resin solution may be of either a single-layer or a multi-layer structure. In the case of a multi-layer structure, the layer may consist of layers of different kinds of resin.
As to the solvents to be added to the preceding resin solution, the solvents to be employed for diluting the resin solution to form a coating liquid, and the solvents to be employed for forming a coating film layer which will be brought into contact with a coating film layer of the hardenable resin solution, can be chosen from ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; alcohols such as methanol, ethanol, propanol and butanol; esters such as methyl acetate, ethyl acetate, butyl acetate, ethyl lactate and ethylene glycol monoacetate; ethers such as glycol dimethyl ether, glycol monoethyl ether, dioxane and tetrahydrofuran; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as methylene chloride, ethylene chloride, carbon tetrachloride, chloroform and dichlorobenzene.
In case that a used resin is water soluble, water or a solvent mixed with water may be used as the above solvents.
Usable supports include polyesters such as polyethylene terephthalate and polyethylene-2,6-naphthalate; polyolefins such as polypropylene; cellulose derivatives such as cellulose triacetate and cellulose diacetate; and plastics such as polyamide and polycarbonate. Also usable are metals such as Cu, Al and Zn, glass, BN, Si carbide and ceramics.
When the present invention is applied to a pre-sensitized (PS) plate, a support of an aluminum plate or an anodic oxidized aluminum plate can be preferably employed.
The present invention is advantageous for producing a pre-sensitized plate, in particular, a waterless printing plate of a multi-layer structure. A waterless printing plate can be obtained by providing layers of the following constitution on a support.
That is, a primer layer, a light-sensitive layer and a silicone rubber layer are provided on a support in this sequence from the supportside. It is preferred that the primer layer contains a diazo resin and a hydroxyl group-containing polymer and can be hardened by light exposure before the provision of a light-sensitive layer.
A light-sensitive layer is provided on the primer layer. Any substance may be employed as long as its solubility in a developer changes before and after exposure.
The examples of a light-sensitive layer are a layer of a substance which is soluble in a developer when exposed to light, such as o-quinonediazo compounds and o-nitrobenzyl carbinol ester compounds, and a layer of a substance which is insoluble in a developer when exposed to light, such as diazo compounds and compounds containing an addition-polymerizable vinyl group. Besides the above substances, it is possible to add to a light-sensitive layer a dye, a pigment, an exposed part visualizing agent and a coatability improving agent to improve development image visualizing property, exposure image visualizing property and coatability.
The amount per surface area of a light-sensitive layer is preferably 0.1 to 30 mg/dm 2 , more preferably, 0.5 to 10 mg/dm 2 .
A silicone rubber layer is provided over the light-sensitive layer. A preferable silicone rubber is linear or suitably somewhat cross-linked organopolysiloxane. The organopolysiloxane has a molecular weight ranging from a thousand to hundreds of thousands, and is appropriately cross-linked to be in a liquid- or paste-like state at room temperature. According to the manner of cross-linkage, the organopolysiloxane can be divided into condensation-type organopolysiloxane and addition-type organopolysiloxane.
The silicone rubber layer, which is adjusted to be hardenable, brings about most excellent results when employed in the present invention.
The organopolysiloxane molecule has the following structure units in its main chain: ##STR1## wherein R 1 and R 2 each represent alkyl, allyl or alkenyl which may contain a substituent such as a cyano radical, a halogen atom and a hydroxyl radical or a combination thereof. Preferred for R 1 and R 2 are methyl, phenyl, vinyl and trifluoropropyl radical, and especially preferred is methyl radical.
As the cross-linking agent for the organopolysiloxane which gives rise to a condensation reaction are ##STR2## a condensation-type silicone cross-linking agent containing the above radicals (wherein R and R' each represent an alkyle radical) such as de-acetic acid type, de-oxime type, de-alcohol type, de-amino type and de-hydration type or a functional radical represented by --OH. The examples of such cross-linking agents include methyltriacetoxy silane, vinyl triacetoxy silane, methyltri(N-methyl, N-acetylamino)silane, vinyltri(methylketooxime)silane and oligomers thereof. Organic carboxylic acids, titanic acid esters and naphthenic acid are employed to promote catalytic function.
The examples of the commercially available silicone rubber are KS-705F (manufactured by Shinetsu Chemical Co., Ltd.), KE-41, 42 and 44 (manufactured by Toshiba Silicone Co., Ltd.), YE5505 and YF3057 (manufactured by Toray Silicone Co., Ltd.), condensation-type silicone rubber such as SH-781, PRX-305 and SH-237; KS-837, KE-103, KE-106 and KE-1300 (manufactured by Shinetsu Chemical Co., Ltd.), TSE-3032 and RTU-B (manufactured by Toshiba Silicone Co., Ltd.) and addition-type silicone rubber such as SH-9555 (manufactured by Toray Silicone Co.).
To improve the mechanical strength of silicone rubber, cross-linking agents such as the preceding silanes and dibutyl tin dilaurate, or an inorganic filler such as silica, titanium oxide and aluminum oxide may be added to the silicone rubber layer. As the filler, silica is preferable. The filler preferably has an average particle size of not more than 500 nm in respect of dispersibility or dispersion stability.
To improve image quality and developability, it is preferred that the thickness of the silicone rubber layer be small. However, to improve press life and to prevent printing contamination, the silicone rubber layer is required to be thick to some extent. Generally, the amount per surface area of the silicone rubber layer is 3 to 50 mg/dm 2 , preferably 5 to 30 mg/dm 2 .
EXAMPLES
The present invention will be described in more detail according to the following examples.
EXAMPLE 1
On a corona-treated polyethylene terephthalate base of 100 μm in thickness, a silicone rubber (YF-3057 manufactured by Toshiba Silicone Co., Ltd.) solution of the following composition (Solution A) which contained a composite polymerization inducer consisting of dibutyl tin dilaurate and TSL-8180 (methyltriacetoxy silane manufactured by Toshiba Silicone Co., Ltd.) as the hardenable resin solution, a silicone rubber (YF-3057) solution of the following composition (Solution B) as the unhardenable resin solution and hexane (Solution C) as the solvent were continuously applied by means of a slide hopper over a period of 5 hours in such a manner that the both sides of a coating film layer of Solution A (wet thickness: 1-15 μm) were brought into contact with a coating film layer of Solution B (wet thickness: 2-5 μm) and that of Solution C (3-5 μm), thereby forming a silicone rubber layer with various layer thickness ratios.
During the continuous coating, stuck resin solids (designated as "A" and "B" in FIG. 3) were not formed at either the edge or the ridge of the slide hopper, and longitudinal streak trouble was not observed in the silicone coating layer.
______________________________________ Parts by weight______________________________________Composition of Solution A:Silicone rubber (YF-3057) 100Hexane 1400TSL-8180 10Dibutyl tin dilaurate 0.8Composition of Solution B:Silicone rubber (YF-3057) 100Hexane 1400TSL-8180 10Composition of Solution C:Hexane Necessary amount______________________________________
COMPARATIVE EXAMPLE 1
Solution D (wet thickness: 20 μm) of the same composition as that of Solution A was continuously applied onto the surface of a support web by means of a slide hopper to form a single coating layer of 1.5 μm in dry thickness. One hour after the start of coating, longitudinal streaks were formed in the coating layer, and coating was stopped to check over the slide hopper. Stuck resin solids formed by the hardening of Solution D were found to be adhering to the edge and ridge of the slide hopper.
______________________________________Composition of Solution D: Parts by weight______________________________________Silicone rubber (YS-3057) 100Hexane 1400TSL-8180 10Dibutyl tin dilaurate 0.8______________________________________ | A method of coating a first resin solution containing a polymerization inducer on a moving web-like support with a coating device, comprising conveying the support to pass near the coating device without coming in contact with the coating device, disposing the first resin solution in a form of a first resin solution layer from the coating device onto the support; the first resin solution layer having a lower surface which faces the support and an upper surface opposite to the lower surface; and the coating device having a first release point at which the upper surface leaves the coating device and a second release point at which the lower surface leaves the coating device; overlaying the first release point with a solvent, thereby superimposing a solvent layer on the upper surface of the first resin solution layer; overlaying the second release point with a second resin solution which does not contain a polymerization inducer, thereby superimposing a second resin solution layer on the lower surface of the first resin solution layer; and applying the superimposed layers onto the support so that the solvent layer forms an uppermost layer on the support. | 1 |
FIELD OF THE INVENTION
This invention relates to highly-oriented materials and to improved processes for nucleation and growth thereof.
BACKGROUND OF THE INVENTION
The formation of highly-oriented structures, such as single crystals, single-domain liquid crystals, or uniaxially oriented crystallites is of major technological importance for many applications that range from reinforcing materials to electronic displays.
Small molecules are frequently processed into oriented structures by a technique known as epitaxial crystallization onto single-crystalline substrates. Examples of substrates commonly used for epitaxial growth are quartz, muskovit, alkalihalides, and salts of aromatic organic acids.
The use of some moderately oriented, semi-crystalline polymers as substrates for epitaxial growth of a few materials is described by Petermann and Broza (J. Petermann and G. Broza, J. Mater, Sci, 22, 1108 (1987)), who employed moderately oriented polyethylene, isotactic polypropylene, poly(butene-1), and isotactic polystyrene as substrates for epitaxial crystallization of several metals. Although some success was reported for a few species, such as Sn, Te, and Bi, the phenomenon certainly was not general, and no effects were observed with Zn, Au, Ni, Co, Ge, Sb. No epitaxial effects were observed with poly(vinylidene fluoride).
More recently in U.S. Pat. No. 5,180,470, it is disclosed that highly-oriented polytetrafluoroethylene having an orientation angle of less than 20° can be an effective substrate for the formation of macroscopically oriented structures of a wide variety of materials. Indeed, in the patent it is demonstrated that various organic materials, such as adipic acid, anthraquinone, and 5-chlorophenol; inorganic materials, such as thallium chloride; polymers, such as polyethylene, nylon 6, and polyvinylidenefluoride; and liquid crystals, such as 4-cyano-4'-octanebiphenyl, and 4-cyano4'-dodecanebiphenyl, can be obtained in oriented form when deposited onto the polytetrafluoroethylene substrate from the melt, solution or vapor phase.
However, it is difficult to orient some organic materials on the oriented polytetrafluoroethylene (PTFE hereinafter) substrate because of the nature of the PTFE. For example, PTFE is hydrophobic and it is difficult to orient hydrophilic materials onto it. In addition, PTFE is a relatively soft polymer and easily abraded, which limits end-use applicability in some instances.
It would be advantageous to impart certain properties to the final oriented structure which are currently difficult to impart due to the nature of the PTFE orienting layer.
SUMMARY OF THE INVENTION
It has now been found that the oriented polytetrafluoroethylene (PTFE) substrate can be provided with an overlayer material having a desired property that is imparted to the resulting structure, and then a further oriented layer of a desired material provided as a top layer. In other words, the effectiveness of the oriented polytetrafluoroethylene (PTFE) substrate as an orientation-inducing substrate is not decreased by the presence of the overlayer material. This can be of practical value when orienting layers of specific physical or chemical properties that are desired and that are different from the physical or chemical properties of PTFE.
For example, a polyimide overlayer can be provided covering the oriented PTFE substrate layer to impart durability and hardness to the composite structure and then liquid crystals can be epitaxially deposited on the overlayer material.
Likewise, a hydrophilic overlayer material can be provided covering the oriented PTFE substrate layer to impart hydrophilic properties to the composite structure and then hydrophilic liquid or non-wettable crystals such as dichroic dyes, can be epitaxially deposited on the overlayer from aqueous or alcohol solution.
DETAILED DESCRIPTION OF THE INVENTION
Thus, the invention provides for coating a highly-oriented PTFE layer that is on a substrate with an overlayer and then epitaxially covering the overlayer with still other materials. The oriented PTFE is a layer of aligned molecular polymer chains.
The invention is based on the fact that the oriented PTFE structures, prepared according to U.S. Pat. No. 5,180,470, incorporated herein by reference, facilitate crystal nucleation and formation of highly-oriented crystallites or liquid crystals. What is surprising in the invention herein is that by placing an overlayer over the aligned PTFE chains to alter the chemical and physical properties of the layered composite, still additional layers of oriented crystallites or liquid crystals can be formed over the overlayer. In other words, the presence of the overlayer does not eliminate the good orienting ability of the aligned PTFE chains.
As a first step in obtaining the structures of the invention a suitable substrate is coated with PTFE in a manner which results in the PTFE polymer chains being aligned with respect to one another.
While unoriented PTFE itself may be the substrate, suitable substrates include virtually any flat, smooth surface, such as glass, quartz, polymers, and the like. The surface can be cleaned if desired.
The substrate is coated with a thin film of oriented PTFE. As described in U.S. Pat. No. 5,180,470, PTFE is compression molded into a solid structure such as a pellet, bar, ingot, rod, stick or the like. It is then pressed against and along the substrate in a smooth motion while applying a moderate force. This leaves a thin film (e.g. 5-50 nm thick) of a highly-oriented film of PTFE. Alternatively, PTFE in powder form can be spread on the substrate with a spreading knife using a smooth motion and a moderate force. In still another method, a dispersion of PTFE can be uniformly spread in a chain-orienting manner on the substrate.
In a preferred mode, a bar of compression molded PTFE is dragged across a glass substrate so as to lay down a thin layer of oriented PTFE on the substrate.
The treated substrate is then coated with a thin overlayer of the overlayer material. Most conveniently, the overlayer is applied by painting, spraying or dipping the treated substrate with a solution of the overlayer material.
For example, in the case of an overlayer of a hydrophilic polymer, the polymer can conveniently be applied from an aqueous or organic solution, simply by dipping the treated substrate in the solution in a manner that leaves a thin layer of the overlayer material on the treated substrate.
A wide variety of hydrophilic polymers can be used as the overlayer. For example, the polymer may be a copolymer of a fluorine-containing ethylenically unsaturated monomer and a non-fluorinated vinyl monomer containing a hydrophilic group. It may be made by copolymerizing the monomers.
Preferably the fluorine-containing monomer of the fluorine-containing copolymer will be a vinyl monomer such as, for example, tetrafluoroethylene, vinyl fluoride, vinylidene fluoride, monochloro-trifluoroethylene, dichlorodifluoroethylene, hexafluoropropylene, and the like.
More preferably, the fluorine-containing vinyl monomer can be described as
CXY=CFZ
wherein Z can be fluorine or hydrogen and X and Y can each be selected from hydrogen, fluorine, chlorine and --CF 3 .
Other desirable fluorine-containing monomers useful herein include:
CH 2 =CR
COORf
CH 2 =CR
OCORf
CH 2 =CR
O=C--Rf
CH 2 =CR
O--Rf
CH 2 =CR
CONHRf
In the above formulae, R is hydrogen, fluorine, a methyl group, an ethyl group, a trifluoroethyl group ((CF 3 ), or pentafluoroethyl (C 2 F 5 ). Rf is a perfluoroalkyl group with four to 21 carbons.
Meanwhile, examples of monomers that contain hydrophilic groups include those that have hydroxyl groups, carboxyl groups, sulfone groups, phosphoric acid groups, amide groups that may be N-substituted, and amino groups that may be N-substituted. Monomers in which an alkylene oxide such as ethylene oxide or propylene oxide has been subjected to an additional reaction with the active hydrogen in these groups are also favorable. Those that yield copolymers containing hydrophilic groups by performing first copolymerization and then hydrolysis, such as vinyl acetate, are also used.
Specific examples of these hydrophilic monomers include vinyl alcohol, acrylic acid, methacrylic acid, and other such unsaturated carboxylic acids, as well as alkylene oxide adducts of acrylic acid or methacrylic acid, such as those shown below.
CH 2 =CR
COO(C 2 H 4 O)nH
CH 2 =CR
COO(C 3 H 6 O)nH
CH 2 =CR
COO(C 3 H 6 O)m(CF 2 H 4 O)nH
CH 2 =CR
CONH(CH 2 ) 3 NH 2
In the above formulae, R is hydrogen or a methyl group and n and m are integers greater than or equal to one and preferably one to twenty.
Both the fluorine-containing monomer and the monomer containing hydrophilic groups may be used singly or in combinations of two or more types. And if needed, other vinyl monomers, such as alkyl esters or acrylic acid or methacrylic acid, esters of trimethylol propane or other such polyhydric alcohol and acrylic acid or methacrylic acid, and the like can also be used jointly with the above-mentioned fluorine-containing monomer and the monomer containing hydrophilic groups.
The copolymer of vinyl alcohol with the fluorine-containing monomer may be prepared by saponifying a copolymer of vinyl acetate with the fluorine-containing monomer to thereby convert the acetate group contained in the copolymer into the hydroxyl group. In this case, all of the acetate groups contained in the copolymer are not necessarily replaced by the hydroxyl group and the conversion of the acetate groups into the hydroxyl groups may be carried out to the extent needed to provide the copolymer with hydrophilic properties.
The fluorine content of the fluorine-containing hydrophilic copolymer to be used in the present invention may range usually from 2% to 60%, preferably from 10% to 60%, and most preferably 20%-60% on a weight basis. If the fluorine content of the fluorine-containing hydrophilic copolymer becomes too high, on the one hand, the hydrophilic properties of the polymer may be lessened, though the heat resistance becomes better. If the fluorine content becomes too low, on the other hand, adhesion of the fluorine-containing hydrophilic polymer to the porous fluoropolymer membrane may be reduced and the heat resistance may be decreased.
The equivalent weight is the formula weight divided by the number of functional units in the formula and will be generally between 45 and 700, preferably, 60-500 and most preferably, 60-450.
If the equivalent weight is lower than 45, the water solubility of the fluorine-containing hydrophilic copolymer may be too high and the fluorine-containing copolymer will elute away with water; and if the equivalent weight is higher than 700, the hydrophilic properties will be lessened, but the interaction between the copolymer and the porous membrane will be increased and thus the copolymer will not tend to elute away.
The following Table provides the mole % fluorine monomer units in the copolymer, the fluorine weight % (F-wt %) and the equivalent weight (EqW) for a number of copolymers (where VOH is vinyl alcohol):
______________________________________ Mole % of F-monomer Molar Ratio UnitsCopolymer in Copolymer in copolymer F-wt % Eq-W______________________________________(CF.sub.2 = CF.sub.2).sub.x / x = 1, y = 40 2.4 4.2 45.5(VOH).sub.y 1, 30 3.2 5.5 46.4 1, 20 4.8 7.9 48.0 1, 10 9.1 14.3 53 1, 4 20 27.5 68 1, 1 50 53.1 143 10, 1 91 72.8 1043(CF.sub.2 = CH.sub.2).sub.x / x = 1, y = 40 2.4 2.1 44.6(VOH).sub.y 1, 30 3.2 2.8 45.2 1, 20 4.8 4.1 46.2 1, 10 9.1 7.5 49 1, 4 20 -- -- 1, 1 50 33.6 107 10, 1 91 55.6 683(CFH = CH.sub.2).sub.x / x = 1, y = 40 2.4 1.1 44.2(VOH).sub.y 1, 30 3.2 1.4 44.6 1, 20 4.8 2.1 45.3 1, 10 9.1 4.0 47.6 1, 4 20 -- -- 1, 1 50 21.3 89 10, 1 91 37.8 503(CF.sub.2 = CFCl).sub.x / x = 1, y = 40 2.4 3.1 46.0(VOH).sub.y 1, 30 3.2 4.0 46.9 1, 20 4.8 5.8 48.9 1, 10 9.1 10.4 54.6 1, 4 20 -- -- 1, 1 50 35.8 159 10, 1 91 47.2 1208(CF.sub.2 = CCl.sub.2).sub.x / x = 1, y = 40 2.4 2.0 46.5(VOH).sub.y 1, 30 3.2 2.7 47.7 1, 20 4.8 3.8 50.0 1, 10 9.1 6.7 57 1, 4 20 -- -- 1, 1 50 20.8 183 10, 1 91 26.3 1442(CF.sub.2 = CFCF.sub.3).sub.x / x = 1, y = 40 2.4 6.1 46.8(VOH).sub.y 1, 30 3.2 7.9 48.0 1, 20 4.8 11.3 50.5 1, 10 9.1 19.6 58 1, 4 20 -- -- 1, 1 50 59.0 193 10, 1 91 73.9 1543______________________________________
The porous fluoropolymer membrane coated with the hydrophilic fluorine-containing copolymer may be prepared, for example, by dissolving the hydrophilic fluorine-containing copolymer in an organic solvent such as, for example, an alcohol, ketone, ester, amide or hydrocarbon, and immersing the porous fluoropolymer membrane in the resulting solution; or impregnating the membrane with the resulting solution by spraying the membrane with the resulting solution; or by coating the former with the latter by means of rolls, and drying the resulting product.
To prepare an overlayer of a polyimide, it is most convenient to apply an overlayer of a polyamic acid to the treated substrate by painting, spraying, or dipping. A polyamic acid of methylene dianiline and benzophenone dianhydride in a solvent of n-methyl pyrollidone and xylene is available from the DuPont Company. By heating the resulting composite, the polyamic acid is converted to polyimide.
The resulting overlaid layered composite can then be used to further deposit a wide variety of oriented materials by chemical or vapor deposition, or melt-or solution-crystallization. In particular, vapor or solvent deposition of crystallizable material or liquid crystal forming material can be carried out. These materials align their molecules along the alignment of the underlying PTFE aligned chains of molecules. Representative suitable crystallizable and orientable materials for enhanced nucleation and orientation include polymers, oligomers, smaller organic molecules, metals, alloys of metals, ceramics, ceramic precensors, etc. These materials can be deposited by a wide variety of methods. Specifically, suitable materials can be deposited by crystallization from the melt or from solution. Alternatively, the crystallizable materials can be deposited from their vapors, or through any form of chemical vapor deposition, or decomposition. In yet another method, the suitable materials can be formed onto the oriented poly(tetrafluoroethylene) through epitaxial synthesis, or methathesis. In still another application of the present invention, polymerizable monomers, are deposited onto the oriented poly(tetrafluoroethylene), which are subsequently polymerized.
The temperature at which contacting in any form of the crystallizable material with the ultra-oriented polymer structure is executed is not critical, provided that the temperature is below the melting or decomposition temperature of the oriented poly(tetrafluoroethylene) structure and the overlayer.
It is surprising that highly-oriented structures can be obtained despite the presence of the overlayer between the oriented PTFE layer and the orientable upper material.
The orientation of the oriented PTFE need not be uniaxial. Specific patterns, such as waved, concentric, or cross-hatch can be employed.
The oriented structures of the present invention have many applications that will be dictated by the intrinsic physico/chemical properties of the materials. For example, the induction of nucleation and oriented crystal growth of a wide variety of substances is of great use for many opto/electronic materials and devices.
The following examples are provided for illustrative purposes only, and are not intended to limit the scope of the present invention, which is defined in the appended claims.
EXAMPLE 1
Coating of the Highly-Oriented PTFE Layer With Polyamic Acid of Methylene Dianaline (MDA) and Benzophenone Dianhydride (BPDA)
The polyamic acid of MDA and BPDA (18.5% solids) in n-methyl pyrollidone (NMP) and xylene was obtained from the Dupont Company. This material was identified as RC 5060 Pyre--M.L. wire enamel. Three stock solutions were made from the 18.5% solution as follows:
A. 1.6 ml of 18.5% solution in 128 g Xylene and 205 g NMP
B. 3.2 ml of 18.5% solution in 128 g Xylene and 205 g NMP
C. 12.8 ml of 18.5% solution in 128 g Xylene and 205 g NMP
Glass plates about 6 ×8 inches (15.2 -20.3 cm) were coated to produce oriented PTFE. Specifically, the glass plate was placed on a platform and heated by radiant heat to a temperature of 200° C. A tape of PTFE was prepared by lubrication (paste) extrusion of coagulated dispersion type PTFE, evaporating the lubricate and stretching the extruded tape at 2:1 to make the tape compliant. This tape was wrapped around a heatable bar about 14 inches long. The wrapped bar was then heated to about 300° C. and then the bar dragged over the glass substrate with adjustable force. Multiple passes were made to ensure complete coverage of the glass surface. By dragging the PTFE bar, PTFE is deposited on the surface of the glass in aligned rows of PTFE chains.
Glass samples were dip coated in a polyamic acid stock solution. The coating process consisted of a 30 second soak in the solution A, B or C, followed by a constant rate of withdrawal as shown in Table 1. The samples were allowed to dry at room temperature overnight. The samples were then heated in a air recirculating oven at 250° C. for two hours to convert the polyamic acid to an overlayer of polyimide.
A glass specimen without the oriented PTFE layer was included as a control.
The samples were then coated with dichroic dye G205 by heating the dye and depositing the vapors on the substrate in a vacuum deposition chamber. The vacuum was 8+10 -6 torr.
Orientation of the deposited dye on the overlayer surface was determined by the change in absorbance/transmission using a known polarizing film. For samples labelled "yes" in Table 1, the absorbance/transmission indicated the dye was oriented to form a polarizer.
Results are given in Table 1 below.
TABLE 1______________________________________ PTFE Layer/ Direction to Polyimide Rate PTFE LayerSample Solution inch/min. Orientation Polarized______________________________________1 A 15 90° yes/yes2 A 1.5 90° yes/yes3 A 15 0 yes/yes4 A 1.5 0 yes/yes5 B 15 90° yes/yes6 B 15 0 yes/yes7 B 1.5 0 yes/yes8 B 1.5 90° yes/yes 9* B 1.5 -- no/no10 C 15 90° yes/yes11 C 1.5 90° yes/yes12 C 1.5 0 yes/yes13 C 1.5 0 yes/yes______________________________________ *Sample 9 was clear glass. No PTFE was on it.
Example 2
Experiments like those in Example 1 were carried out with 1.5%, 3% and 6% polyamic solution in Xylene and NMP.
______________________________________ PTFE Layer Direction to Polyamide Rate PTFE LayerSolution % inch/min Orientation Polarizer______________________________________1.5 15 0 yes/yes3 15 0 yes/yes6 15 0 yes/yes______________________________________
Example 3
Coatings of Highly-Oriented PTFE Layer With Hydrophilic Polymer Overlayer
A. Preparation of PTFE coated substrates
Glass microscope slides (from Fisher Scientific Co.) were used as substrates. The glass substrates were coated with polytetrafluoroethylene according to the method disclosed in U.S. Pat. No. 5,180,470 with an instrument that was designed for accurate and consistent deposition of thin films to result in oriented thin films. The equipment is comprised of two parts; a lower, temperature controlled, movable stage and a pivoting, temperature controlled, polytetrafluoroethylene holder. The heatable lower stage is mounted on a linear positioning stage. The speed and direction of the positioning stage are controlled by a precision micro-stepper drive system. The upper section is a counter-balanced, temperature controlled support for a polytetrafluoroethylene rod. Holders are designed to support a standard 1/2 inch polytetrafluoroethylene rod with its axis perpendicular to the substrate that is to be coated. Like the lower stage, the temperature of the upper section is controlled by a self-tuning temperature controller with an upper temperature limit of 400° C. The interfacial pressure between the polytetrafluoroethylene rod and the substrate is controlled by varying the weights loaded onto the upper section generating approximately 2.5 MPa pressure. Standard grade polytetrafluoroethylene was employed. The polytetrafluoroethylene was deposited onto the glass slides at temperatures in the range between 250° and 300° C. at a rate of 1 millimeter per second.
B. Deposition of hydrophilic polymer 0.1% and 0.01% solution of a hydrophilic copolymer were prepared in a 50/50 wt. ratio of ethyl alcohol and methyl alcohol. PTFE coated glass from Part A was dipped into each of the solutions for a few seconds at room temperature and withdrawn and dried. The copolymer was a copolymer of tetrafluoroethylene and vinyl alcohol.
C. Deposition of crystalline compounds
The hydrophilized polytetrafluoroethylene glass substrates of Part B were coated with water-soluble crystalline compounds by applying the compound from solution by pillette. The crystalline compound was polycaprolactone in chloroform in an amount of 1 wt. percent, and was applied by dragging the pipette across the surface. Subsequently, the samples were air dried at room temperature, removed from the chamber, and examined in a polarzing optical microscope.
Degree of orientation
Orientation was established by visual inspection under cross-polarizers.
Examination in the polarized optical microscope of the films revealed that all samples were birefringent and were crystalline; good orientation was observed along the direction in which the polytetrafluoroethylene coating was deposited. | Oriented materials are described in which particular crystalline materials are grown on a highly-oriented polytetrafluoroethylene substrate. Compositions are provided comprising a layer of aligned molecular chains of oriented polytetrafluoroethylene and an overlayer of a second polymer that imparts desired properties to the construction. A third layer of crystallizable, orientable material is then deposited on the overlayer. The third layer becomes oriented. The materials are useful as polarizers when the third layer is a polarizing dye. | 2 |
FIELD OF THE INVENTION
The subject matter of this application relates to decorative stands that support substantially spherical objects such as pumpkins, melons, or balls; or those somewhat conical objects such as planters which have a top circumference greater in size than its lower circumference, in a manner that is vaguely humanoid in appearance.
BACKGROUND
Many people do some degree of holiday decorating throughout the year. For some of these people, the decorating endeavor is quite extensive and requires large amounts of holiday-specific paraphernalia.
One of the holidays associated with extensive decorating is Halloween and some elaborately decorated residences can be found in most neighborhoods where Halloween is celebrated. Those people that decorate, will often decorate for more than one holiday. The amount of decorations used for a season will vary based on the decorator, but many people become serial accumulators of holiday decorations. For these people especially, the storage of these decorating items in the off-season is an increasing problem. Obviously, as more items are required, the space needed to store them when not in use increases.
Of all the symbols and items associated with Halloween, perhaps the most iconic is carved pumpkin. Often, whether to increase visibility of the pumpkin, or to place the pumpkin in a decorative context, the pumpkin is placed on some type of stand. Display stands that present pumpkins in a decorative manner are known in the art. U.S. Pat. No. 6,546,654 discloses a number of decorative pumpkin stands. Patents U.S. D444411, U.S. D445356, U.S. D445357, U.S. D445720, U.S. D520405, and U.S. D591530 also disclose different pumpkin stands.
Although decorative when in use, when not in use these stands are bulky and difficult to store.
SUMMARY
The subject matter of this application is a readily collapsible decorative stand for substantially spherical objects such as pumpkins, melons, or balls; or for somewhat conical objects such as planters which have a top circumference greater in size than its lower circumference, (the “load”) that forms a vaguely humanoid structure. The stand can be quickly assembled and disassembled without tools. In its disassembled state, the stand requires comparatively little storage space.
The stand consists of a girdle portion that reversibly attaches to at least two leg portions and, in at least one preferred embodiment, also to at least two arm portions. When assembled, a load is placed onto the girdle so that the load suggests the torso and head of a humanoid structure. The leg portions are rigid, but the arm portions may be flexible, allowing the stand, in its assembled form, to suggest humorous, whimsical, or threatening postures.
In one preferred embodiment, smooth male attachment regions of the arms and legs can be reversibly coupled with smooth female attachment regions located on the outer surface of the girdle portion. If additional structural stability is desired, compatible male and female threads may be present on the male and female attachment regions, respectively, to additionally secure said arms and legs.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective drawing of a preferred embodiment of the assembled stand disclosed in this application, the stand is further placed in context with the addition of a sphere representing a carved pumpkin as the stand might hold as a Halloween decoration.
FIG. 2 is an exploded perspective drawing of this stand.
FIG. 3 is a drawing of the girdle portion showing how the girdle's attachment points interact with the attachment regions of the arm and right leg portions.
DETAILED DESCRIPTION OF THE INVENTION
The following description and drawings referenced therein illustrate an embodiment of the application's subject matter. They are not intended to limit the scope. Those familiar with the art will recognize that other embodiments of the inventive concepts are possible. All such alternative embodiments should be considered within the scope of the invention.
Each reference number consists of three digits. The first digit corresponds to the figure number in which that reference number is first shown. Reference numbers are not necessarily discussed in the order of their appearance in the figures.
For convenience, the term “load” will be used in the following description, however that term should be understood to include any substantially spherical objects such as pumpkins, melons, or balls; or those somewhat conical objects such as planters which have a top circumference greater in size than its lower circumference.
The stand disclosed in this application is comprised of a girdle portion [ 101 ], at least two leg portions and, in preferred embodiments, at least two arm portions. In a most preferred embodiment, there are two arm portions [ 102 and 104 ], upwardly oriented from the girdle portion, that are reversibly attached to opposite sides of the girdle portion; similarly, in the most preferred embodiment, there are two leg portions [ 103 and 105 ], downwardly oriented from the girdle portion, that are reversibly attached to opposite sides of the girdle portion. In this embodiment, the positions of the two arm portions and two leg portions suggest a humanoid structure.
When the most preferred embodiment is assembled, the disclosed stand has a right and left side, with one leg portion and one arm portion located on the right side and one leg portion and one arm portion located on the left side. Although it is not necessary that the right and left leg portions, or the right and left arm portions, be exact mirror images of each other, to avoid duplication only a single arm, and a single leg portion will be described below. It should be understood that, unless specified, details given for a single arm or leg appendage correspond to both the right and left side variants.
The girdle portion [ 101 ] is a roughly circular shape having an outer [ 212 ] and an inner surface [ 211 ] so that it may support a load placed onto the girdle portion. Said girdle portion further comprises a number of attachment points [such as 301 and 302 ] that in a preferred embodiment are joined to the outer surface [ 212 ] although said attachment points may also be joined to the inner surface [ 211 ]. In the most preferred embodiment, there are four such attachment points [such as 301 and 302 ], two of these are located on the right side of said girdle portion (as viewed in an assembled stand) and the remaining two are located on the left side of said girdle portion. On both the right and left side of said girdle portion (as viewed in an assembled stand), one of the attachment points [either, e.g., 301 or 302 ] is intended to reversibly attach to that side's leg portion's attachment region [e.g. 201 ] and the other attachment point is intended to reversibly attach to that side's arm portion's attachment region [e.g. 208 ]. Although the preferred embodiment comprises a roughly circular girdle portion, said girdle portion may alternatively be in a hexagonal, pentagonal, triangular or other polygonal shape.
A leg portion consists of an attachment region [ 201 ], a thigh region [ 202 ], a calf region [ 203 ], and a foot region [ 204 ]. An angle [ 205 ] is formed by the attachment region and the thigh region [ 202 ]. An angle [ 206 ] is formed by the thigh region [ 202 ] and the calf region [ 203 ]. An angle [ 207 ] is formed by the calf region [ 202 ] and the foot region [ 204 ]. In most preferred embodiments, the angles [ 205 , 206 , and 207 ] are fixed so that when the stand is assembled, the leg portions are capable to supporting the weight of the stand itself and the stand when supporting a load. In the most preferred embodiment, the mass of the stand is distributed over the two leg portions so that the stand is does not tip either forward or backward when supporting a load. In an alternative embodiment, the angle [ 206 ] formed by the thigh region [ 202 ] and the calf region [ 203 ] may be 180 degrees. It such an alternative embodiment, descriptive terms such as “calf” and “thigh” might not apply since there may be no clear demarcation between the regions.
An arm portion consists of an attachment region [ 208 ], a bicep region [ 209 ], and a forearm region [ 210 ]. An angle [ 215 ] is formed by the attachment region [ 208 ] and the bicep region [ 209 ]. An angle [ 213 ] is formed by the bicep region [ 209 ] and the forearm region [ 210 ]. Those angles [ 215 and 213 ] may either be fixed or adjustable so as to allow the stand, in its assembled form, to suggest humorous, whimsical, or threatening postures. In an alternative embodiment the angle [ 213 ] is formed by the bicep region [ 209 ] and the forearm region [ 210 ] may be 180 degrees. In such an alternative embodiment, descriptive terms such as “bicep” and “forearm” might not apply since there may be no clear demarcation between the regions.
The girdle portion's [ 101 ] attachment points [such as 301 and 302 ] may be of any shape capable of accepting a corresponding attachment region, but are, in a preferred embodiment, a tubular material, such as a portion of pipe with an inner diameter large enough to reversibly accept the attachment regions of either a leg portion [ 201 ] or of an arm portion [ 208 ]. In this preferred embodiment, these attachment points are oriented so that they are perpendicular to the ground when the stand is assembled. When the stand is assembled, the said attachment regions of an arm portion [ 208 ] or of a leg portion [ 201 ] are held in conformation to the said girdle region's attachment points [e.g. 302 and 301 ] by the action of gravity. In the case of an arm portion's attachment region [ 208 ], gravity pushes the attachment region down into a said attachment point, until the angle [ 215 ] formed by the attachment region and the bicep region contacts the said attachment point (e.g. 302 ), preventing further downward movement of said arm portion. Similarly, in the case of an leg portion's attachment region [ 201 ], gravity pushes an attachment point (e.g. 301 ) down onto said leg portion's attachment region, until the angle [ 205 ] formed by the attachment region and the thigh region contacts the said attachment point, preventing further downward movement of said arm portion. In another preferred embodiment, the attachment regions of arm portions [ 208 ] or leg portions [ 201 ] further comprise male threads that correspond to female threads located in said girdle region's attachment points [such as 301 and 302 ].
In an alternative embodiment, accessory appendages may be reversibly attached to the girdle (e.g. the accessory attachment regions [ 303 and 304 ]) in the manners disclosed for the leg or arm portions to further enhance the decorative nature of the resulting humanoid figure. Such accessory appendages may include those resembling ears, wings, horns, wings, and other such decorative adjuncts; or may include appendages with functional aspects such as those holding a light or sound source, those holding signs, those equipped with motors, or other functional appendages. | A stand, separable into parts, that can support substantially spherical objects such as pumpkins, melons, or balls; or those somewhat conical objects such as planters which have a top circumference greater in size than its lower circumference (the “load”) is disclosed. The stand includes a girdle that supports the load, at least two rigid leg segments that reversibly attach to the girdle, and, in a preferred embodiment, at least two rigid or semi-flexible arm segments also reversibly attached to the girdle. The body of the load is not pierced by the stand. When assembled, the stand combined with a load forms a vaguely humanoid structure. When not in use, the stand is capable of being disassembled and stored in a relatively compact form. | 0 |
[0001] The invention relates to a process for preparing phosphorus-containing alkoxylation products by means of heterogeneous catalysts, the products being suitable for use as flame retardants in polyurethanes.
[0002] The preparation of phosphorus-containing alkoxylation products, particularly of organic phosphonates and halogen-substituted alkyl phosphates, is known to the skilled worker. Primarily phosphoric acid, phosphorous acid or phosphorus trihalide, preferably phosphorus trichloride, or phosphorus oxyhalide, especially phosphorus oxychloride, are used and are reacted with epoxides such as ethylene oxide, propylene oxide and/or epichlorohydrin. To increase the reaction rate it is common to use catalysts. For catalysts which operate homogeneously there are numerous versions known to the skilled worker.
[0003] Generally speaking, however, the alkoxylated products obtained have to be purified in systems which operate with homogeneous catalysis, which is costly and inconvenient. Aftertreatment is usually accomplished by an aqueous workup of the crude reaction products, in the course of which the catalyst is destroyed irreversibly and separated off.
BACKGROUND ART
[0004] This is described for example in DD 125 035, where deactivation and/or destruction of the titanium halide catalyst is achieved by adding a stoichiometric amount of water or by washing the phosphorus-containing alkoxylation products with water or alkalis.
[0005] Aftertreatments of this kind for destroying and/or deactivating the catalyst, however, have disadvantages. They necessitate reactors additionally; there is a deterioration in the space-time yield; and losses of product occur. The washing waters produced must be disposed of, which is costly and inconvenient. And, not least, the catalyst employed is lost to further use. Apart from the processes with homogeneous catalysis, the use of heterogeneous catalysts is largely unknown.
[0006] One heterogeneous catalysis system was recently described by Yang, Jin-Fei in Yingyong Huaxue 2003, 20 (2), 201-202, using TiSiW 12 O 40 /TiO 2 , for the preparation of (ClCH 2 CH 2 O) 3 PO. A disadvantage associated with the use of the catalyst is the comparatively costly and inconvenient preparation.
[0007] A continuous production method of 2-haloalkylated phosphates by means of heterogeneous catalysts is described in CN 1 034 206. In that case BeO is employed. The process permits the preparation of low-acid products (acid number<0.2 mg KOH/g solid) such as (MeCHClCH 2 O) 3 PO, (ClCH 2 CHClCH 2 O) 3 PO, and (ClCH 2 CH 2 O) 3 PO. A disadvantage associated with the use of the catalyst is the potential release of highly toxic beryllium salts.
[0008] U.S. Pat. No. 3,557,260 proposes the use of sulfates of various elements. The required reaction time is approximately 80 hours and is much longer, for economic operations, than the state of the art.
[0009] The object of the present invention was therefore to develop a process for preparing phosphorus-containing alkoxylation products, using heterogeneous catalysts, while avoiding the disadvantages of the prior art.
SUMMARY OF THE INVENTION
[0010] The solution to this problem, and hence the subject of the present invention, is a process for preparing low-acid, phosphorus-containing alkoxylation products by reacting phosphorus trihalides and/or phosphorus oxyhalides with alkylene oxides, with omission of additional water washing or alkali washing of the phosphorus-containing alkoxylation products, which comprises using alumina-containing, heterogeneous catalysts.
[0011] Surprisingly the phosphorus-containing alkoxylation products prepared by means of alumina-containing heterogeneous catalysts exhibit a much lower acid number than in the prior art. The other advantages of the process of the invention, based on heterogeneous, alumina-containing catalysts, lie in the easy, anhydrous separability of the catalyst from the starting substances and the reaction products. This ease of separation therefore makes it possible to do without costly and inconvenient product washing, and allows the production operation to be made more economic in relation to the prior art. The formation of acidic by-products is suppressed, as is apparent from the extremely low acid numbers of the phosphorus-containing alkoxylation products. Furthermore, in the case of a batchwise procedure, the catalyst employed can be used again.
DETAILED DESCRIPTION OF THE INVENTION
[0012] Phosphorus-containing reactants used in the process of the invention are preferably phosphorus trihalides and/or phosphorus oxyhalides, especially phosphorus trichloride and/or phosphorus oxychloride, and they are reacted, individually or in a mixture with one another, with the alkylene oxides. Examples of alkylene oxides are ethylene oxide, propylene oxide, styrene oxide, cyclohexene oxide, cyclopentene oxide, glycidyl ethers, epichlorohydrin, epoxidized polybutadiene, and epoxidized unsaturated oils. The alkylene oxides may also be used in a mixture with one another with the phosphorus trihalides and/or phosphorus oxyhalides. In this way it is possible to obtain phosphorus-containing alkoxylation products such as, for example, tri(chloropropyl) phosphate (TCPP), tri(chloroethyl) phosphate (TCEP), tri(chloropropyl) phosphite or tri(chloroethyl) phosphite.
[0013] In one particularly preferred embodiment propylene oxide and/or ethylene oxide are used as alkylene oxide.
[0014] As alumina-containing heterogeneous catalysts it is preferred to use compounds of the general formula (I)
[Al) 1 3+(B) n b+]O m (I)
in which
B is a metal or nonmetal from the group Li, Na, K, Mg, Ca, Sr, Ba, Sc, Y, Ln, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, B, Ga, In, Si, Ge, Sn, Pb, P, As, Sb, and Bi, b is the valence of the metal or nonmetal B and is an integer between 1 and 6, l, n, and m are numerical variables selectable independently from the numbers 0.0001 to 4.0000, so that:
2×m=1×3+n×b.
[0018] Examples of (mixed) metal oxides can be oxides of the elements of the transition group of the Periodic Table of the Elements, or oxides of the metals from groups 13-15 of the Periodic Table of the Elements. In this context, the term “Periodic Table of the Elements” is understood below to be that according to IUPAC (Nomenclature of Inorganic Chemistry 1989). Particular preference is given to the (mixed) metal oxides of groups 3-6, 13, and 14 of the Periodic Table of the Elements.
[0019] With particular preference B stands for ions of the element group
Na, K, Mg, Ca, Sc, Y, Ti, Zr, W, Si, and Sn, the other variables being as defined above.
[0021] With very particular preference in accordance with the invention Al 2 O 3 is used in the process of the invention.
[0022] In accordance with the invention it is, however, also possible to use what are called alumina-containing mixed oxides as heterogeneous catalysts.
[0023] Examples of mixed oxides are the following:
SiO 2 *Al 2 O 3 , SnO 2 *Al 2 O 3 , TiO 2 *Al 2 O 3 , ZrO 2 *Al 2 O 3 , WO 3 *Al 2 O 3 , Sc 2 O 3 *Al 2 O 3 , Y 2 O 3 *Al 2 O 3 , Na 2 O*Al 2 O 3 , K 2 O*Al 2 O 3 , MgO*Al 2 O 3 , and CaO*Al 2 O 3 .
[0025] The mixed oxides here are to be interpreted not only as stoichiometric combinations but also as combinations of nonstoichiometric compositions. This is intended to be expressed by the symbol “*”. In particular, combinations of metal oxides of one and the same element in different oxidation states are among those which may find use.
[0026] The heterogeneous catalysts employed are then composed, accordingly, of mixed metal oxides or metal nonmetal oxides, and may additionally have been modified by means of further chemical operations. Examples of such modifications include sulfating, hydrating or calcining.
[0027] For application as heterogeneous catalysts in the preparation of alkoxylated, phosphorus-containing compounds it is possible on the one hand for them to be physically prepared mixtures of alumina-containing metal oxides, such as by trituration or grinding, for example. Also possible, on the other hand, is the use of heterogeneous, alumina-containing catalysts obtained by means of sol/gel processes.
[0028] The heterogeneous alumina-containing catalysts are notable preferably for extensive insolubility in the reaction medium, and they can be removed from the reaction medium by simple, nonaqueous methods—for example, by simple filtration methods, or by utilizing centrifugal forces.
[0029] The process of the invention for preparing phosphorus-containing alkoxylation products by means of alumina-containing heterogeneous catalysts can be carried out either continuously or batchwise. Where the process is carried out batchwise it comprises adding the heterogeneous alumina-containing catalyst prior to the reaction of phosphorus trihalide and/or phosphorus oxyhalide with alkylene oxides, in two or more portions before or during the reaction. The reaction takes place at temperatures of 0 to 100° C. The reaction temperatures are situated preferably between 50 and 80° C. The reaction takes place at atmospheric pressure or under a slight overpressure of up to 1 MPa. The phosphorus trihalide and/or phosphorus oxyhalide is charged to the reaction vessel and, following the addition of catalyst, the alkylene oxide is metered in continuously. The reaction medium can be diluted by adding phosphorus-containing alkoxylation products with one of the reactants or separately therefrom. After the end of the metering of alkylene oxide an after-reaction phase is added on, at temperatures of 60 to 130° C., and, finally, volatile impurities are removed by vacuum distillation and/or nitrogen stripping at temperatures of 90 to 150° C. and pressures of up to <0.05 MPa. Volatile constituents are removed preferably at 130° C. and 40 mbar. No aftertreatment of the catalyst is necessary. In batch preparation processes of alkoxylated, phosphorus-containing compounds the alumina-containing catalysts are employed in an amount of 0.02% to 10% by weight, based on the phosphorus compound employed, and are added to the phosphorus-containing reactant.
[0030] Alternatively, in a continuous operation, the synthesis of alkoxylated, phosphorus-containing compounds can be operated using heterogeneous alumina-containing catalysts, in which case fluid bed reactors or tube reactors, for example, are employed. In this case the heterogeneous alumina-containing catalyst is the stationary phase and the reaction medium is the mobile phase. The reaction conditions are similar to those already described above in relation to the batchwise procedure.
EXAMPLES
[0000] Example 1
[0031] 6 g of Al 2 O 3 are weighed out together with POCl 3 (76.8 g, 0.5 mol) into a flask and left to stand under reduced pressure overnight. The amount of POCl 3 is then ascertained and supplemented. Subsequently trichloropropyl phosphate (TCPP) (100 g, 0.3 mol) is added and propylene oxide (102 g, 1.75 mol) is metered in over the course of 4 h. This is followed by stirring at 45° C. for 2 h.
[0032] Yield of TCPP prepared: 158 g, 96% of theory, based on POCl 3 .
[0033] Example 2
31 P NMR Residual SZ T R [mol % TCPP] PO [GC TCPP mg KOH/g AAS Catalyst [° C.] 0 to −5.5 ppm area %] OP(Oiso)3 OP(On)3 OP(Oiso)2(On) OP(Oiso)(On)2 ether 2-MP sample [ppm metal] TiCl 4 65 0.01 66.3 0.2 25.6 3.7 2.9 0.1 not inventive Si0 2 Al 2 O 3 75 97.1 2.92 48.2 0.8 31.7 8.4 3.1 0.0 8.9 <1 Al 2 O 3 75 98.2 4.84 50.0 0.5 29.7 6.3 3.3 0.0 <1.0 18 Al 2 O 3 /MgO 75 96.3 6.21 51.7 0.5 23.9 5.2 2.5 0.0 <1.0
[0034] General operating instructions: 5 g of POCl 3 are introduced and the catalyst (1 g) is added. The mixture is then heated to 50° C. and by means of a Telab pump model BF 411/30 (pump setting HUB [stroke]=30, delivery=50% =about 0.5 ml/min) a mixture of 11.7 g (7 ml) of POCl 3 and 20.9 g (25.1 ml) of propylene oxide is added dropwise. The temperature is maintained between 40 and 50° C. (60 and 70° C.) by means of a water bath. After the end of the addition (GC/NMR) there is a subsequent stirring time of 180 minutes at 50° C. (70° C.) with subsequent analysis by means of GC and 31P-NMR, determination of acid number, and determination of metal content by means of atomic absorption spectroscopy. | The invention describes a process for preparing alkoxylated, phosphorus-containing compounds, using heterogeneous catalysts based on metal oxides of aluminum, so that the product can be worked up anhydrously. | 2 |
FIELD OF THE INVENTION
The present invention lies in the field of environmental engineering and more particularly to improve the quality and the flow of air delivered by fans.
BACKGROUND OF THE INVENTION
Currently, portable and stationary fans such as a ceiling fan provide only connection for a light fixture and do not provide direct and multiple connections to air quality improvement devices. The present invention provides fans with an ability to connect one or a combination of different air quality improvement devices such as heaters, coolers, filters, UV lights to improve and condition air where they operate. Therefore consumers are provided with versatile portable and stationary fans that heats and cools and filters the air as desired.
SUMMARY OF THE INVENTION
The present invention lies in the field of environmental engineering and more particularly to improve the quality of air delivered by fans. Currently, fans such as a ceiling fan provide only built-in connection for a light fixture and do not provide direct and multiple built-in connections to air quality improvement devices. The present invention provides multifunctional portable and stationary fans that include a universal connector for one or a combination of air quality improvement devices. The universal connector include easy and safe versatile mechanical, magnetic, and electrical connections for air quality improvement devices such as filters, heaters, coolers, UV lights, electrostatic filters, and ionization devices such as ozone generators. Therefor, consumers are provided with a multifunctional fan that conditions and improves air where it operates.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A shows a ceiling fan and a light fixture connection port that is attached to the ceiling fan.
FIG. 1B shows a ceiling fan and a universal connector that is attached to the ceiling fan.
FIG. 2 shows a vertical universal connector including a male vertical connector attached to an air improvement device and a female vertical connector attached to a stationary fan.
FIG. 3 shows a horizontal universal connector including a male horizontal connector attached to an air improvement device and a female horizontal connector attached to a stationary fan.
FIG. 4 shows detailed description of a rotational universal connector including a male rotational connector and a female rotational connector.
FIG. 5 shows detailed description of a self-locking universal connector including a male self-locking connector and a female self-locking connector.
FIG. 5A shows cross section 1 — 1 of FIG.5 including a complementary air filter that envelops and attached to stationary fan blades.
FIG. 6 shows a magnetic universal connector including a male magnetic connector and a female magnetic connector.
FIG. 7 shows detailed description of a multiple connector including multiple male connectors and multiple female connectors.
FIG. 8 shows detailed description of a number of air quality improvement devices including a secondary fan and a heating unit and a cooling unit connected to a stationary fan using an universal connector comprising a male and a female connectors.
FIG. 9 shows detailed description of a portable fan including a universal connector and an air quality and quantity improvement devices such as a filter and a heating unit connected to the universal connector.
FIG. 10 shows a side view of a portable multifunctional fan including a cooling unit connected to the portable fan.
FIG. 11 shows a front view of a portable multifunctional fan including a cooling unit connected to the portable fan.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1A shows a typical ceiling fan including a light fixture connection port 16 A and a ceiling connector box 11 . Light fixture 16 B is connected to said port 16 A. Light fixture connection port 16 A is only for connecting light fixtures such as 16 B and is not for air quality and quantity improvement devices such as a heating unit and an UV biological filter both of which have different mechanical and electrical connection requirements. Furthermore, voltage and current (AMP) and associated cable sizes and safety requirements are not provided by said port 16 A for said air improvement devices.
FIG. 1B shows a preferred embodiment of present invention including a stationary fan 10 attached to a ceiling by mechanical means using ceiling connection box 11 that has electrical connections to a power source. Said fan 10 includes fan rod 12 connected to box 11 and fan motor unit 13 connected to said electrical power source such as AC main or DC available from box 11 through rod 12 . Fan blades 14 are connected to said motor unit 13 that has a control switch. Extension rod 16 is connected to fan rod 12 through fan motor unit 13 and a universal connector such as 15 attached to said extension rod 16 . Said built-in universal connector 15 replaces light fixture ports such as 16 A and provides versatile mechanical and electrical connections for air quality and quantity improvement devices. Universal connector 15 includes a vertical male connector 15 A and a vertical female connector 15 B. Therefor, fan light fixture connection port 16 A is replaced by said female connector 15 A which is connected to said male connector 15 B and a blank connector 15 C. Said male connector 15 A is attached to an air quality and quantity improvement device. Stationary fan 10 and its universal connector 15 meet with voltage and AMP requirements of an air improvement device such as a heater and an electrostatic filter and include associated right sized cables for said voltage and AMP requirements.
FIG. 2 shows a vertical universal connector 15 comprising a female connector 15 A and male connector 15 B. Said female connector 15 A is connected to fan 10 using extension rod 16 and said male connector 15 B is connected to a desired air quality and quantity improvement devices such as an UV light disinfectant 21 or a light fixture. Said connector 15 includes electrical connection using female and male terminals 19 and 20 respectively and mechanical connections using female and male locking devices 17 and 18 respectively. Therefor, electrical and mechanical connections are established between stationary fan 10 and said improvement device 21 using said connector 15 . The connection is easily established using said connector 15 without using any tools and without being exposed to safety hazards associated with wire-to-wire connections and open wire connectors. Said safety hazards, however, are present in light fixture connection ports such as 16 A of a typical ceiling fan as shown in FIG. 1 A.
FIG. 3 shows a horizontal universal connector 22 comprising a female connector 22 A and male connector 22 B. Said female connector 22 A is connected to fan 10 using extension rod 16 and said male connector 22 B is connected to a desired air quality and quantity improvement devices such as an electrostatic filter 23 or is connected to a light fixture. Said connector 22 includes electrical connections similar to the ones explained in FIG. 2 . The electrical and mechanical connections are easily established without using any tools and without being exposed to open wire connections.
FIG. 4 shows a rotational universal connector 24 comprising a female connector 24 A and male connector 24 B. Said female connector 24 A is connected to stationary fan 10 using extension rod 16 and said male connector 24 B is connected to desired air quality and quantity improvement devices such as an ionic filter and ozone generator 25 or a light fixture. Said connector 24 includes electrical and mechanical connections between fan 10 and said improvement device 25 using connector 24 . The connection is easily established without cutting off the power source and without using any tools and being exposed to safety hazards associated with open wire connections.
FIG. 5 shows a self-locking universal connector 26 comprising a female connector 26 A and male connector 26 B. Said female connector 26 A is connected to stationary fan 10 using extension rod 16 and said male connector 26 B is connected to a desired air quality and quantity improvement devices such as a chemical filter 27 . Said connector 26 includes mechanical connections between fan 10 and said improvement device 26 using said connector 26 . A complementary fan blade filters 14 A envelops and covers blades 14 . Complementary filter 14 A is easily installed by moving said filter 14 A in direction of 14 B and removed by moving said filter 14 A in the direction of 14 C over blade 14 .
FIG. 6 shows a magnetic universal connector 28 comprising a female connector 28 A and male connector 28 B. Said female connector 28 A is connected to fan 10 using extension rod 16 and said male connector 28 B is connected to a desired air quality and quantity improvement devices such as a physical filter 29 . Said connector 28 includes electromechanical connections between fan 10 and said improvement device 29 . The connection is easily established without using any tools and without being exposed to wire connections.
FIG. 7 shows a multiple connector 30 comprising more then one and a combination of universal connectors such as 24 . Said universal connectors are connected to a multiple male connector 30 B which is connected to ceiling fan 10 using multiple female connector 30 A which is attached to extension rod 16 of said ceiling fan 10 . One or more than one desired air quality and quantity improvement devices such as 25 are connected to male connector 30 B using 24 A and 24 B. Said connector 30 includes electrical and mechanical connections between fan 10 and said improvement devices such as 25 . The connection is easily established using universal connector 30 without using any tools and without being exposed to safety hazards associated with open wire connections.
FIG. 8 shows a secondary fan 31 with a self locking universal joint 32 and a heating and cooling unit 33 which include a heating unit 33 A and a cooling unit 33 B. Heating unit 33 A consist of one or combination of a metal heating element and ceramic heating element and quarts/crystal heating element. Cooling unit 33 B consist of a removable cooled or frozen grid filled with fluid. Said grid is cooled and frozen in an available freezer. Said cooling unit 33 B is connected to said secondary fan 31 or directly connected to said stationary fan 10 using a universal blank male connector 15 C attached to said unit 33 B. Said male connector is connected to female connector 26 A that is attached to secondary fan 31 and stationary fan 10 . Said cooling unit 33 B includes a condensation water retention chamber 33 C build in and said chamber 33 C collects condensation water. Heating unit 33 A is connected to female connector 26 A which is attached to said secondary fan 31 and fan 10 using male connector 26 B attached to said heating unit 33 A. Said heating unit 33 A is to condition air in terms of temperature to more desired levels to supplement other means of indoor heating. Since air near ceilings has relatively higher temperature than air near floors, the efficiency of heating unit 33 A would be higher. The secondary fan 31 with a self locking universal joint 32 can also be used to manage the direction of the air flow delivered by fan 10 to cover areas where fan 10 can not generate strong enough air circulation alone. FIG. 8 also demonstrates possible combinations of different air quality and quantity improvement devices in a desired order in sandwich construction using a universal connector and its female and male universal connectors.
FIG. 9 shows detailed description of portable fan 34 comprising a power source 35 and a motor 36 and blades 37 connected to said motor 36 that is powered by power source 35 . Air quality improvement devices such as an electrostatic filter 38 and a heating unit 40 are attached to said fan 34 using a universal connector such as 39 which includes female and male connectors 39 A and 39 B respectively. Heating unit 40 consist of heating element 41 which is powered by same electric power source 35 which powers fan motor 36 . Universal connector 39 includes female and male connectors for electrical and mechanical connections for air quality devices. FIG. 9 also shows fan 34 which includes portable arm 42 A and stand 42 that is connected to 42 A using rotational joint 43 and stand leg 44 attached to stand 42 . In summary, one or a combination of air quality improvement devices such as electrostatic filter and ionic filter and ozone generator and physical filter and heating unit and cooling unit and a secondary fan are connected to portable fan 34 using a universal connector such as 39 .
FIG. 10 shows a side view of a portable fan 34 comprising a cooling unit 45 a power source 35 and a motor 36 and blades 37 connected to said motor 36 that is powered by 35 . Fan 34 includes portable arm 42 A and stand 42 connected to 42 A using rotational joint 43 and stand leg 44 attached to stand 42 . Cooling unit 45 includes a removable grit 46 filled with fluid which is cooled and frozen using an available freezer. FIG. 10 and 11 show a cooling unit 45 attached to a portable fan 34 using slide in-and-out or clip in-and-out connector such as 47 . Connector 47 includes lock 48 to secure grit 46 and a condensation water collection and containment chamber 50 that can be drained as needed. Fluid collection and retention chamber can be designed as a part of grit 46 or as a part of connector 47 depending on the size of the fan 34 .
While I have fully shown and described embodiments of my apparatus for universal ceiling fan no limitations as to the scope of the present invention should be implied from the foregoing description. The true scope of the present invention is limited only by the following claims. | The present invention improves both the quality and the flow of air delivered by a stationary fan such as a ceiling fan and a portable fan. Ceiling fans provide limited indoor air flow, but do not function as air conditioning and quality improvement apparatus. The present invention provides fans with an ability to increase indoor and outdoor air quality where they operate. One or a combination of a cooling unit and a heating unit and a filtering device and a secondary multidirectional fan provide consumers with air quality improvement options for stationary and portable fans to fulfill their specific needs for a given area. | 5 |
This application is a divisional of co-pending U.S. patent application Ser. No. 13/252,650, entitled “PRECODING SELECTION FOR RETRANSMISSION IN UPLINK MIMO HYBRID ARQ”, filed Oct. 4, 2011, which in turn claims the benefit of U.S. Provisional Application No. 61/389,461, entitled, “Precoding Selection for Retransmissions in Uplink MIMO Hybrid ARQ”, filed Oct. 4, 2010, the contents of all of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates generally to broadband and wireless communications and more particularly to precoding selections for retransmissions in uplink multiple-input multiple-output MIMO Hybrid automatic repeat request HARQ.
Uplink (UL) multiple-input multiple-output (MIMO) with linear precoding has been considered as one important feature for the enhancement of UL transmission in new LTE-Advanced (LTE-A) standard for the fourth generation (4G) cellular systems. The feasibility studies for UL precoding in single user MIMO have shown that an approximately 3 dB gain can be achieved by the precoding over the no precoding transmission for a codebook size of 16. After extensive discussions, the precoding codebook for the UL MIMO has been finalized in for up-to-four transmit antennas.
On the other hand, synchronous non-adaptive hybrid ARQ (HARQ) is still the basic principle for LTE-A UL transmissions, which is the same as that in the LTE systems. In the synchronous non-adaptive HARQ, the retransmission is scheduled in the fixed time instance and the fixed resource block with the same modulation and coding scheme (MCS) as that of the original transmission. The adaptive retransmission is only used as a complement to non-adaptive HARQ to avoid fragmenting the uplink frequency resource or to avoid collisions with random-access resources. The physical hybrid ARQ indicator channel (PHICH) carries the acknowledgement (ACK or NACK) and is transmitted from the base station to the user equipment (UE). Without additional information, the synchronous non-adaptive UL retransmission is operated by default. When adaptive retransmission is scheduled, the resource block and MCS information are delivered to the users through the physical downlink control channel (PDCCH) for the uplink retransmissions.
Since, in LTE systems, the uplink MIMO is not supported, only one codeword is transmitted for each time interval. Thus, the problem regarding the multi-codeword MIMO in hybrid ARQ as that for the DL the hybrid ARQ does not exist. However, this is not the case in LTE-A systems when the uplink MIMO is introduced. Therefore, non-adaptive UL retransmission triggered by PHICH in LTE should be extended to multi-codeword transmission in LTE-A UL. For multi-codeword transmission in uplink MIMO, when the number of codewords in the retransmissions is different from previous retransmissions, how to assign the precoding for the retransmissions is a problem. Here we assume that at most two codewords are allowed for transmission across multiple layers in UL MIMO. Based on the latest discussions in 3GPP meetings, when the number of codewords in the retransmissions is same as previous retransmissions, the rank and precoding vector stay the same, and the retransmission does not carry any automatic power adjustment command.
Several schemes have been proposed for the precoder selections for non-adaptive HARQ in UL MIMO: 1) User terminal selects whatever the precoder wants; the basestation can still decode since the demodulation reference signal (DMRS) is precoded; 2) Use of subset of columns of a precoding matrix with the one corresponding to larger Modulation and coding scheme (MCS); 3) Use of predefined precoding matrix (fixed or cycle) among a set of precoding matrix; 4) a single antenna transmission mode; 5) Using the same precoding matrix as that in the original transmission and occupying all layers; and 6) Precoding column compression with a merger of the columns.
However, none of the aforementioned techniques address the problem of precoding selections at the user terminal for retransmitting one or multiple codewords in non-adaptive hybrid ARQ for uplink (UL) MIMO when the transmission rank or number of codewords in the retransmissions is smaller than the corresponding value in the original transmission. Particularly, the problem framework considers that only imperfect channel state information (CSI), e.g., quantized channel information, is available at the user terminal. Accordingly, there is a need for precoding selection for retransmission in uplink hybrid ARQ that solves this problem.
BRIEF SUMMARY OF THE INVENTION
The invention is directed to a method that includes obtaining a precoder for retransmission of one codeword responsive to a known precoding matrix of a certain rank and modulation and coding scheme assignments used in an original transmission, and a desired retransmission rank′, forming an approximate channel covariance matrix; estimating an a minimum mean square error receiver signal-to-noise-interference-ratio for each layer to be retransmitted responsive to the prior forming; and finding a precoding matrix from a preceding codebook that maximizes a sum-rate for enabling precoding selections for retransmissions in uplink multiple-input multiple-output MIMO hybrid automatic repeat request HARQ.
In an exemplary embodiment of precoding selection for Physical Hybrid ARQ Indicator channel PHICH triggered non-adaptive HARQ in UL MIMO, the method includes obtaining a precoder for retransmission of one codeword responsive to known precoding matrix P of rank r in an agreed uplink codebook in and LTE-A standard and modulation and coding scheme assignments used in an original transmission, and a desired retransmission rank r′; for precoding selection for transmit antennas n T 2, desired retransmission rank r′=1, determining a receiver SINR for a given precoder; and obtaining a precoding selection for transmit antennas n T =4 and a transmission rank r and desired retransmission rank r′ combination responsive to at least one of maximizing determination of
g † R ^ g
and lookup information in an uplink UL codebook in said LTE-A.
These and other advantages of the invention will be apparent to those of ordinary skill in the art by reference to the following detailed description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of precoding selection in non-adaptive hybrid automatic repeat request HARQ in uplink UL MIMO, in accordance with the invention; and
FIG. 2 is a block diagram of the inventive precoding selection for Physical Hybrid ARQ Indicator channel PHICH triggered non-adaptive HARQ in UL MIMO, in accordance with the invention;
DETAILED DESCRIPTION
The present invention is directed to the problem of precoding selections at the user terminal for retransmitting one or multiple codewords in non-adaptive hybrid ARQ for uplink (UL) MIMO when the transmission rank or number of codewords in the retransmissions is smaller than the corresponding value in the original transmission. Particularly, this problem analysis considers that only imperfect channel state information (CSI), e.g., quantized channel information, is available at the user terminal.
The block diagram of FIG. 1 shows the inventive precoding selection for non-adaptive HARQ retransmission for UL MIMO with imperfect/partial channel information. Initially, 101 , the user terminal knows the precoding matrix P of rank r and the MCS assignments used in original transmission, as well as the desired retransmission rank r′. Based on these inputs we obtain the precoder for the retransmission of one codeword.
Following the input step 101 , the method 102 forms an approximate channel covariance matrix {circumflex over (R)}, given by R H † H≈PDP † {grave over (R)}, where
D = diag { λ 1 , … , λ r } ,
and complex matrix H is the UL uplink channel. To obtain {λ j }, we use the MCS information of each codeword assigned by base station. The MCS to a codeword is assigned based on the estimated effective SINR at eNodeB for the whole codeword, i.e., the largest MCS level that can achieve a block error rate (BLER) smaller than 10% for a given effective SINR. Thus, according to the empirical BLER curves of turbo coded modulation for all MCS levels in the standard, given the MCS assignments in the original transmission, we can find the signal-to-noise ratio (SNR) threshold at 10% BLER for such MCSs and use them as the {λ j } for all the layers mapped to this codeword. For example, the SNR thresholds for the MCS level 8 (QPSK, code rate Rc=0.5137) and level 16 (16 QAM, Rc=0.6016) are 1.2676 dB and 8.1354 dB, respectively. If these two MCS levels are assigned to a rank-2 precoding, we then obtain the corresponding absolute values of {λ j } given by 1.3389 and 6.5094, respectively. From the layer-codeword mapping rules, we then have D=diag{1.3389, 6.5094} for r=2 and D=diag{1.3389, 1.3389, 6.5094, 6.5094} for r=4.
After the preceding formation of the covariance matrix 102 , for a precoding matrix G, 103 , the method then estimates a minimum mean square error MMSE receiver SINR for each layer to be retransmitted, given by
SIN R i ′ ( G ) = Ξ i , i 1 - Ξ i , i ≈ α i 1 - α i
where
α
i
=
[
(
I
+
G
†
R
^
G
)
-
1
G
†
R
^
G
)
ii
,
and
Ξ
≈
(
I
+
G
†
R
^
G
)
-
1
G
†
R
^
G
.
Lastly, the precoding matrix G is found 104 from the precoding codebook that maximizes the sum-rate i.e.
G ′ = arg ∑ i = 1 r ′ log 2 ( 1 + SIN R i ′ ( G ) ) ,
where
ℊ n T × r
is the complex matrix space of dimensions n T ×r and
SIN R i ′ ( G )
is the signal-to-interference-plus-noise ratio (SINR) for the ith layer at the receiver.
Specifically, for retransmission rank r′=1, we have
g ′ = arg g † H † Hg ,
where
ℊ n T × r ′
is a finite set, and G′ is obtained by searching from all elements in the set.
The block diagram of FIG. 2 shows the inventive precoding selection for PHICH triggered non-adaptive hybrid HARQ in UL MIMO.
Initially with the invention, 201 , the user terminal knows the precoding matrix P of rank r in the agreed UL codebook in LTE-A and the MCS assignments used in original transmission, as well as the desired retransmission rank r′. Based on these inputs we obtain the precoder for the retransmission of one codeword.
Then under the inventive method, 202 , with a precoding selection for n T =2, r′=1 occurs, we obtain the receiver SINR for a given precoder according to the relationship
SIN R ′ ( g ′ ) = λ 1 g 1 ′ 2 + λ 2 g 2 ′ 2
where the precoding vector for retransmitting one codeword is
g ′ = [ g 1 ′ , g 2 ′ ] T .
From the layer-1 UL codebook in LTE-A for n T =2 in Table 1, the first four vectors offer the same SINR, but the last two which utilize only one transmit antenna results in a smaller SINR. Therefore, the precoding vector for retransmission can be chosen as any one of the first four precoding vectors in Table 1 of the UL codebook, e.g. the first precoder (of index 0) in Table 1. Since the original precoding vector is an identity matrix which does not align to any channel matrix, for the retransmission with a lower rank r′<r, the better choice is cycling of the precoders among the first four precoding vectors in Table 1.
Then the method obtains the precoding selection for n T =4 case by case 203 .
For the case 204 of a precoding selection for n T =4, r=4, r′=2: the method obtains the per layer SINR from linear MMSE receiver, given by
SIN R i ′ ( G ′ ) = Ξ i , i 1 - Ξ i , i ,
where
Ξ ′ = ( I + G ′† DG ′ ) - 1 G ′† DG ′ .
The sum-rate can thus be obtained by
∑ i = 1 r ′ log 2 ( 1 + SIN R i ′ ( G ′ ) ) .
Then, based on tables in the
UL codebook in LTE-A, we obtain the following selection rule: For n T =4, when the latest transmission is full rank, i.e., r=4, the precoding vector for a retransmission with rank r′=2 can be fixed to be any one of the eight precoding vectors of index 8 to 15 in the 2-layer procoding codebook in Table 3 of the UL codebook in LTE-A, or cycling in time of the eight precoding vectors of index 8 to 15 in the 2-layer codebook in Table 3 of the UL codebook in LTE-A in any fixed order. Precoding selection for n T =4, r=1′: the selected precoder should maximize
g † R ^ g = ∑ i = 1 r ′ λ i g † p i 2 ,
where p t denotes the tth column of P.
For the specific case 206 for r=3: the selected precoder should maximize
g † R ^ g = λ 1 g † p 1 2 + λ 2 4 + λ 3 4 .
We then obtain the optimal precoder indices given in Table 8 of the UL codebook in LTE-A. Since the solution for each P is not unique, we select the one with the lowest index presented in Table 7 of the UL codebook in LTE-A.
For the precoding selection case 205 for n T =4, r=2, r′=1: the selected precoder should maximize
g † R ^ g = λ 1 g † p 1 2 + λ 2 g † p 2 2
or equivalently,
g † R ^ g = λ 1 ( g † p 1 2 + g † p 2 2 ) + ( λ 2 - λ 1 ) g † p 2 2
or
=
λ
2
(
g
†
p
1
2
+
g
†
p
2
2
)
+
(
λ
1
-
λ
2
)
g
†
p
1
2
.
Note that the optimal precoding selection only depends on the order of λ j or the order of MCS assignment in the original transmission. The results are provided in Table 9 of the UL codebook in LTE-A. We can see that for each rank-2 precoder in the original transmission, we have 4 or 2 choices for the retransmission that result in the same rate. For the r=2 precoders of index 8 to 15, the results of optimal retransmission precoding indices are same for two different orders of λ 1 and λ 2 meaning that the resulting precoding selection is solely based on the original precoder. Since the results are not unique, we use the one with the lowest index which is summarized in Table 7 of the UL codebook in LTE-A.
For the precoding selection case 207 for n T =4, r=3, r′=2: The precoding vector for the retransmission with rank r′=2 can be chosen from Table 3 of the UL codebook in LTE-A, with the indices provided in Table 7 of the UL codebook in LTE-A based on the assigned MCSs, or a threshold for MCS1-MCS2, and precoding vectors in the original transmission.
In a simplified version, for n T =4, if we only define one generalized precoder for each retransmission rank r′, based on the results shown in Table 6-8 of the UL codebook in LTE-A and the results for (r=4,r′=2), we can choose the precoder index selected in more cases than others. For example, the precoder with index 8 in a r′-layer codebook for retransmission rank r′.
Note that the precoding index is referring to the latest agreement on uplink precoding codebook defined in TR36.814 v9.0.0 in LTE-A standardizations.
From the foregoing it can be seen that the present invention provides a general precoding selection scheme for non-adaptive HARQ for UL MIMO with practical system constraints. The inventive precoding selection method provides the better system performance for non-adaptive HARQ in UL MIMO over the prior art by imposing the approximation of the channel covariance based on the limited or imperfect channel information available at user terminal. The inventive method obtain the precoding selection for different transmit antenna settings and different ranks in the original transmission. For most cases, the optimal precoding selection only depend on the precoder and the order of the MCSs used in the original transmission or the latest transmission thus can be as simple as the prior art.
The foregoing is to be understood as being in every respect illustrative and exemplary, but not restrictive, and the scope of the invention disclosed herein is not to be determined from the Detailed Description, but rather from the claims as interpreted according to the full breadth permitted by the patent laws. It is to be understood that the embodiments shown and described herein are only illustrative of the principles of the present invention and that those skilled in the art may implement various modifications without departing from the scope and spirit of the invention. Those skilled in the art could implement various other feature combinations without departing from the scope and spirit of the invention. | A method implemented in a user terminal is disclosed. The method comprises obtaining known precoding matrix P of rank r and modulation and coding scheme assignments used in an original transmission, and a desired retransmission rank r′, forming an approximate channel covariance matrix, estimating a minimum mean square error receiver SINR for each layer to be retransmitted responsive to said forming, and finding a retransmission precoding matrix from a preceding codebook that maximizes a sum-rate for enabling precoding selections for retransmissions in uplink multiple-input multiple-output MIMO hybrid automatic repeat request HARQ. Other methods, apparatuses, and systems also are disclosed. | 7 |
This is a divisional of application Ser. No. 08/319,298 filed Oct. 6, 1994, now U.S. Pat. No. 5,602,261 which is a divisional of application Ser. No. 07/977,618 filed Nov. 17, 1992, now U.S. Pat. No. 5,395,951.
The present invention relates to novel triterpene derivatives of azadirachtin from neem plant (Azadirachta indica A. Juss) and a process for preparing novel triterpene derivatives of azadirachtin. The new triterpene derivatives of azadirachtin so prepared are useful in suppressing the insect pest population below the economic threshold level by their antifeedant and growth inhibitory activities.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The imbalance in the ecosystem, human health hazards and the development of resistance by some insect pests caused by the continuous use of conventional insecticides have necessitated the search for alternative safer pesticides. Botanicals by virtue of their reiatively low toxicity, biodegradability and many other factors acceptable to the environment are considered as the best alternatives to toxic chemicals. Among Botanicals, neem tree ranks first in view of its excellent pest control properties, its low mammalian toxicity and relative abundance in countries like India, Pakistan, Burma, Sri Lanka and Africa. No other tree or plant possessing insect-control properties, has received as much attention as neem world over which is evident from the three International and one National (India) conferences held during the past decade.
2. Description of the Prior Art
Although the protection of stored food grains, woolen clothes, fruits and vegetables by neem leaves has been used in India since time immemorial, the first report of the pesticidal properties appeared around 1927 when Mann and Burns [Agri. J. India, Calcutta 22, 325 (1927)] observed during the locust cycle of 1926-27 that adult locusts did hot feed on neem leaves. This was followed by Chopra [Rept. of Dept. of Agr., Punjab Pt.2, Vol. 1. P.67 (1928)] who treated the extract of neem leaves as contact poison on grub weevils. Since then a number of publications describing the various activities from different parts of neem tree have appeared. For example, neem oil has shown antifeedant activity against Nephotettix virescens (leaf hopper of rice). [Neem Newsletter 1 (3) 28 (1984)]. Neem seed extract has shown antifeedant activity against Mythimna separata (rice ear cutting caterpillar) [Neem Newsletter 1 (3), 31 (1984)]. Neem cake has exhibited antifeedant activity against Nilaparvat lugens (Rice Brown Plant Hopper) [J. Economic Entol., 77, 502 (1984)]. Neem oil has shown oviposition deterrent and ovicidal activity against a stored grain pest of rice Corcyra cephalonica (rice moth). Neem seed kernel water suspension has shown oviposition deterrent activity against Spodoptera litura (Tobacco caterpillar) [Phytoparasitica 7(3), 199 (1979)]. Neem leaves extract has shown antifeedant activity against Rhizopertha dominica (lesser grain borer) [Neem Newsletter, 1 (2), 20 (1984)]. Neem root exudates have been reported to contain allelochemicals.
The first active principle exhibiting antifeedant properties against locusts (Schistocerca gregaria) was isolated in 1968 which was named as azadirachtin by Morgan and Butterwoth [Chem. Commn. 23 (1968)]. Since then azadirachtin has been shown to exhibit insect antifeedant and/or growth-inhibitory activities on more than 50 insect species. For example it has exhibited antifeedant activity at a dosage of 0.005% on Earias fabia (spotted cotton ballworm, family, Lepidoptera) [Phytoparasitica, 9 (1), 27 (1981)]. It has shown growth inhibitory activity at a dosage of 5-10 ppm against Spodoptera litura (tobacco caterpillar, Lepidoptera [Proceedings of the National Seminar on Neem in Agri.,] IARI, New Delhi, (1983); Indian J. Expt. Biol, 23(3), 16 (1985) and LD 50 of azadirachtin against S. litura is reported to be 1.1 g/g [J. Entomol. Res., 11 (2), 166 (1987)]. It has been reported to exhibit sterilant, insecticidal, delay in egg hatching, growth inhibitory and antifeedant activities at a dosage of 10-100 ppm against Epilachna verivestis (Maxican bean beetle, Coleoptera [Z pflakrankh pflaschutz, 82 (3), 176 (1975); Z. Angew Entomol, 93, 12 (1982);
Systemic action of azadirachtin through roots to leaves has been reported by Saxena et al [J. Econ. Entomol., 77 (2) 502 (1984)].
The drawing accompanying this specification shows the structure of azadirachtin in formula 1 which was established in 1986 by three groups of workers [Tetrahedron, 43, 2789; 2805, 2817 (1987)].
Till this time more than 80 tetranortriterpenes and derivatives of azadiraachtin have been isolated from neem extracts. Some of them are mentioned here: -nimbinene, nimbandiol, azadiradione, salannin, vilasinin, gedunin, meldenindiol and nimbin. Out of them at least 35 tritenpene derivatives show either insect antifeedant activity growth-inhibitory activity or both. For example azadirachtin A, B, D, E, F and G show insect growth inhibitory activities against Epilachna verivestis at a dosage of 1-10 ppm [Insecticides of Plant Origin, ACS Symposium series, 387, 150 (1989)]. Similarly 3-tigloylazadirachtol has exhibited 97% antifeedant activity at a dosage of 1.0 ppm [Tetrahedron, 45, 5175 (1989)]. Amongst other compounds azadiradione, azadirone, 6-deacetylnimbinene, epoxyazadiradione, gedunin, nimbandiol, salannin and salannol have shown antifeedant and growth-inhibitory activity against E. Verivestis [Proceedings, 2nd International Neem Conference 181 (1983)]. Azadirachtin has been reported to be active against nematodes and whitegurbs [Entomol. Exp. Appl., 24, 448 (1978).
Synthetic insecticides belonging to the class of organochlorine and organophosphorous are found to be quite toxic to mammals, fish, honeybees etc. They pollute the ecosystem by their toxicity and residual action. In addition they cause serious health hazards to human beings. In view of this there is an urgent need to look for safer alternatives and plant products appear to be the right choice because of their relatively low toxicity and biodegradability.
With the above objective we have made extensive research on the pest control properties of the extract from neem seeds and have observed that if the undesirable components viz. the saturated fats and the water soluble compounds including sugars are removed, the resulting extract is enriched with the required active compounds viz, the triterpenoids and the unsaturated fats.
Neem seed extract contains essentially four components namely saturated and unsaturated fats, triterpenoids and water soluble compounds containing sugars. Of these, triterpenoids exhibit insect-antifeedant and growth-inhibitory activity while the unsaturated fats possess insecticidal activity against aphids, mites, jassids, cotton white flies and other soft bodied insects. Of the remaining two, saturated fats are inactive and phytotoxic (above 2% dosage) and the water soluble sugars act as insect attractants and fungal growth promoters. Both these are undesirable in the formulation of pest control agents from neem.
In the known processes of preparing insecticidal composition from neem no attempt has been made to separate all the above said four components so that the concentration of the required compounds, the triterpenoids and the unsaturated fats can be used advantageously for pest control purposes. Some of the processes involve expelling neem oil which contains a low percentage (0.05) of active triterpenoids and directly use for pest control purposes. In some other processes the neem is extracted using a solvent like (hexane) to obtain an oil containing low percentage (0.05) of the active triterpenoids. Consequently, due to the very low percentage of the terpenoids these oils used directly for pest control purposes do not have desirable pest control properties.
A mixture of neem oil, karanja oil, mohua oil, gingely oil, castor oil has also been used but it exhibits phytotoxic properties in field trials. Neem based fertilizer in which neem extractive (crude) is blended with urea and sold as a fertilizer is also commercially available.
In the process of the present invention we have removed all the drawbacks of the existing processes by complete extraction of neem seed powder and solvent partitioning in one step using two immiscible solvents, forming two layers, one solvent layer containing the lipids and the other solvent layer containing the triterpenes and water soluble compounds including sugars. The second solvent layer is treated with a polar solvent in which the triterpenes only are soluble, thus separating them from the undersired sugar fraction by filtration/decantation. Thus, in two steps the active rich triterpenoid fraction exhibiting insect antifeedant and growth-inhibitory activity is obtained which is free from the undesirable lipids and water soluble compounds including sugars. The percentage of the active triterpenoid fraction is about 2.5% based on the seed powder.
Similarly the separation of the undesirable saturated fat (9%) from the total lipids has been achieved by fractional crystallisation from acetone at 0°-10° C. The saturated fats, at the above temperature solidify and are removed by filtration and the unsaturated fats remain in the mother liquor.
During our continued research in the field of pest control agents we observed that 1) neem seed extract is more active biologically than the extract of any other part of the neem tree. 2) Neem seed extract is more active than neem seed kernel extract as the husk or hull of the seeds also contains active principles. 3) Neem seed extract is more active than the expelled oil. 4) Triterpene fraction of the seed extract exhibits antifeedant activity and insect-growth inhibiting activity, while the lipid fraction rich in unsaturated fats is responsible for aphidicidal, miticidal and insecticidal activity against sucking pests and soft bodied insects.
SUMMARY OF THE INVENTION
The present invention provides new triterpene derivatives of azadirchtin from the parts of neem plant (A indica). These new triterpenes have the formulas 2-11 shown in the drawings accompanying this specification.
Another object of the present invention is to provide a process for the preparation of the new triterpenes.
Yet another object of the present invention is to provide a process for the prepration of an extract containing these new triterpenes which are useful as insecticidal compositions.
Still another object of the present invention is to provide a process for the preparation of insecticidal compositions containing lipids.
Though any part of the neem plant can be used in carrying out the present invention disclosed herein, it is preferred to employ the seed or the neem cake powder due to the above findings, that neem seed extract and neem seed cake extract have excellent insect-control activity.
DESCRIPTION OF THE DRAWINGS
FIG. 1--shows the structure of azadirachtin.
FIG. 2--shows triterpenes of Formulas 2-4.
FIG. 3--shows triterpenes of Formulas 5-8.
FIG. 4--shows triterpenes of Formulas 9-11.
FIG. 5--is the HPLC chromatogram of the triterpene active fraction.
DETAILED DESCRIPTION OF THE INVENTION
Accordingly, present invention provides a process for the isolation of new triterpene derivatives of azadirachtin having the formulas 2-11 shown in the drawing accompanying the specification, from the parts of the neem plant, which comprises:
a. grinding the parts of the neem plant to get a powder;
b. extracting the powder with a binary immiscible solvent consisting of one polar and another non-polar solvent in the ratio of 1:2 to obtain an extract;
c. filtering the extract to obtain a filtrate having 2 layers, one layer containing lipids and another layer containing new triterpenes, azadirachtin and water soluble sugars;
d. separating the layers by known methods;
e. concentrating the polar solvent layer containing the new triterpene derivatives of azadirachtin and water soluble constituents;
f. treating the resultant concentrate with a polar solvent; and
g. filtering/decanting the resultant solution to produce a filtrate containing the mixture of new triterpene derivatives of azadirachtin of the formulas 2-11 and known triterpenes including azadirachtin, separating the new triterpene derivatives of azadirachtin by column chromatography.
The separation of the new derivatives may be done using elutes such as ethyl acetate, benzene, acetone, and pet-ether. 120 g of triterpene-active fraction was subjected to column chromatography over Silica gel (60-120 mesh size, 2 kg) using acetone:pet-ether as the elution gradient to collect four broad fractions A (25 g), B (20 g), C (45 g) and D (20 g).
Fraction D (20 g) was put for further fractionation by column chromatography over Silica gel (60-120 mesh, 750 g) using chloroform:methylcyanide as the elution gradient to collect five broad fractions D1 (4 g), D2 (5 g), D3 (1.5 g), D4 (2 g), D5 (7 g) which contained mainly the azadirachtin and azadirachtin derivatives. Out of these, D1 and D2 fractions contained mainly salannin, salannol, nimbandiol and vilasinnin and its derivatives. D3 and D4 fractions contained azadirachtin and its derivatives and D5 fraction contained mostly polar compounds.
Azadirachtin and its new derivatives were isolated from D3 and D4 fractions by repeated column chromatography and preparative TLC using different solvent mixtures such as acetone:pet-ether (4:6), ethylacetate:benzene (9:1) and chloroform:methylcyanide (5:2). The Rf values of the ten new azadirachtin derivatives are different in each solvent system. But we could say that the compound No. (2), (4), (8), (9) and (10) are less polar than azadirachtin in all of the three above solvent systems and the remaining five compounds are more polar than azadirachtin. The structures of the above new azadiirachtin derivatives were established by spectral data (Chart 1 & 2).
__________________________________________________________________________.sup.1 H-NMR DATA OF COMPOUND 2-11 (CHART-1)Serial No.2 3 4 5 6__________________________________________________________________________1-H 3.58(m) 4.68(dd) 4.66(dd) 3.40(m) 5.34(dd) (2.75; 3.0) (2.7; 3.1) (2.65; 2.60)2-H 2.3(ddd) 2.36(ddd) 2.34(ddd) 2.38(ddd) 2.32(ddd)(16.2; 2.65; 3.1) (16.3; 2.8; 3.2) (16.2; 2.8; 3.1) (16.3; 2.65; 3) (16.38; 3.48; 3.22)2-H 2.12(ddd) 2.16(ddd) 2.20(ddd) 2.32(ddd) 2.29(ddd)(16.2; 2.95; 2.8) (16.3; 3.0; 2.8) (16.2; 3.0; 2.8) (16.3; 3.1; 2.65) (16.38; 3.22; 3.11)3-H 5.45(t) 4.48(t) 5.44(t) 5.48(t) 5.50(t)(2.7; 3.1) (2.7; 2.8) (2.7; 2.9) (2.75; 2.8) (2.7; 3.08)5-H 3.3(d) 3.09(d) 3.30(d) 3.24(d) 3.34(d)(12.5) (12.5) (12.5) (12.5) (12.5)6-H 4.40(dd) 4.15(dd) 4.44(dd) 4.48(dd) 4.43(dd)(12.5; 2.7) (12.5; 2.75) (12.5; 2.8) (12.5; 2.65) (12.5; 3.73)7-H 4.62(d) 4.65(d) 4.64(d) 4.8(d) 4.62(d)(2.7) (2.65) (2.65) (2.63) (2.2)9-H 2.62(s) 3.32(s) 3.30(s) 3.30(s) 2.62(s)11-H 4.50(s) -- -- 4.53(s) 5.38(s)15-H 4.56(d) 4.58(d) 4.64(d) 4.50(d) 4.55(d)(3.20) (3.20) (3.20) (3.20) (3.20)16-H 1.65(ddd) 160(ddd) 1.65(ddd) 1.70(ddd) 1.66(ddd)(13.0; 3.5; 5.3) (13.0; 3.5; 5.3) (13.0; 3.5; 5.4) (13.0; 3.35; 5.0) (13.0; 3.8; 5.8)16-H 1.28(d) 1.32(d) 1.30(d) 1.32(d) 1.25(d)(13.2) (13.0) (13.0) (13.0) (13.27)17-H 2.40 2.38(d) 2.36(d) 2.40(d) 2.34(d)(5.0) (5.0) (5.0) (5.0) (5.03)18-H 1.95(s) 2.05(s) 1.198(s) 2.08(s) 1.93(s)19-H 3.58(d) 3.62(s) 3.60(d) 3.62(d) 3.77(s)(9.6) (8.0) (8.5) (9.2)19-H 4.00(d) 3.62(s) 4.02(d) 3.90(d) 3.77(s)(9.6) (8.0) (8.5) (9.2)21-H 5.65(s) 5.64(s) 5.60(s) 5.60(s) 5.63(s)22-H 5.05(d) 5.00(d) 5.0(d) 5.06(d) 5.03(d)(2.9) (2.9) (2.9) (2.85) (2.9)23-H 6.40(d) 6.42(d) 6.42(d) 6.44(d) 6.48(d)(2.9) (2.9) (2.9) (2.85) (2.9)28-H 4.02(d) 3.80(d) 4.16(d) 4.06(d) 4.06(d)(9.0) (7.6) (7.8) (9.0) (8.76)28-H 3.80(d) 3.70(d) 3.80(d) 3.74(d) 3.72(d)(9.0) (7.6) (7.8) (9.0) (8.8)29-H -- 1.04(s) -- -- --30-H 1.76(s) 1.74(s) 1.73(s) 1.42(s) 1.29(s)7-CH -- 2.78(brs) -- -- 2.8(brs)11-CH-- 5.00(s) -- -- 3.26(br.s)14-CH-- 3.06(br.s) -- -- 3.06(br.s)12-OCH.sub.33.65(s) -- 3.65(s) 3.68(s) --29-OCH.sub.33.76(s) 3.77(s) 3.75(s) 3.78(s) 3.77(s)CH.sub.3 COO1.84(s) 1.83(s) 1.93(s) 2.02(s) 1.83(s)Tigloyl6.88(qq) 6.95(qq) Benzoyl gr. -- (7.0; 1.34)3'-H (7.0; 1.3) (7.0; 1.3) 2'-7.9(m) -- (7.0; 1.34) 6'-7.7(m)4'-H 1.76(dq) 1.74(dq) 3'-7.57(m) -- 1/74(dq)(7.0; 1.01) (7.0; 1.01) 4'-7.4(m) -- (7.06, 1.01) 5'-7.6(m)5'-H 1.84(dq) 1.81(dq) -- -- 1.81(dq)1.5, 1.01) (1.5; 1.01) (1.5; 1.01)Com-pound No.7 8 9 10 111-H 4.93(t) 4.60(t) 3.74(t) 4.72(t) 3.62(dd)(2.9; 3.1) (2.85; 3) (2.9; 3.0) (2.9; 3.1) (2.9; 3.0)2-H 2.38(ddd) 2.33(ddd) 2.36(ddd) 2.28(ddd) 2.76(ddd)(16.0; 2.9; 2.7) (16.0; 2.7; 2.8) (16.0; 2.6; 2.8) (16.2, 2.9, 2.6) (16.2; 2.9; 2.65)2-H 2.14(ddd) 2.14(ddd) 2.16(ddd) 2.13(ddd) 2.12(ddd)(16.0; 2.7; 2.8) (16.0; 2.7; 2.8) (16.0; 2.6; 2.8) (16.2; 2.6; 2.9) (16.2; 2.6; 2.85)3-H 5.30(t) 5.15(dd) 5.45(t) 5.48(t) 3.76(t)(2.9; 3.1) (2.9; 3.1) (2.9; 3.0) (2.9; 3.0) (2.8; 3.2)5-H 3.10(d) 3.30(d) 3.30(d) 3.30(d) 3.16(d)(12.5) (12.5) (12.5) (12.5) (12.5)6-H 4.04(dd) 4.04(dd) 4.13(dd) 4.42(dd) 4.16(d)(12.5; 3) (12.5; 3.0) (12.5; 3) (12.5; 3.2) (12.5; 3.0)7-H 4.65(s) 4.44(d) 4.64(d) 4.48(d) 4.62(d)(3.0) (3.0) (3.20) (3.2) (3.0)9-H 2.60(s) 4.24(s) 4.02(s) 3.48(S) 4.02(s)11-H 3.75(m) -- -- -- ---- 3.85(d)(14.0) -- -- --12-H 3.92(br.s) 5.40(d)(14.0) -- -- --15-H 4.55(d) 4.62(d) 4.2(d) 4.18(m) 4.60(d)(3.2) (3.2) (3.0) (3.0)16-H 1.60(ddd) 1.60(ddd) 1.67(ddd) 1.80(m) 1.65(m)(13.0;, 3.4; 5.0) (13.0; 3.4; 5.0) (13.0; 3.4; 5.1)16-H 1.26(ddd) 1.26(d) 1.30(d) 1.90(m) 1.92(m)(13.0) (5.0) (5.0)17-H 2.40(d) 2.58(d) 2.42(d) 2.16(m) 2.14(m)(5.0) (5.0) (5.0)18-H 2.00(s) 1.98(s) 2.07(s) 1.55(s) 2.04(s)19-H CH.sub.3 -1.32(s) 1.23(s) 1.40(s) 3.66(d) CH.sub.3 -1.45(s) (9.7)19-H 4.28(d) (9.7)21-H 5.62(s) 5.60(s) 5.62(s) 5.65(s) 5.62(s)22-H 5.05(d) 5.05(s) 5.04(s) 4.88(s) 1.88(s)(2.90) (2.90) (3.0) (2.9) (2.9)23-H 6.40(d) 6.40(d) 6.40(d) 6.36(d) 6.36(d)(2.90) (2.90) (3.0) (2.9) (2.9)28-H 3.70(br.s) 4.55(s) 3.72(d) 3.69(d) 3.65(d) (9.0) (9.6) (8.8) (8.6)28-H 3.70(br.s) 3.85(d) 3.60(d) 4.04(d) 3.92(d) (9.0) (9.0) (8.8) (8.5)29-H 1.05(s) -- -- -- --30-H 1.58(s) 1.68(s) 1.73(s) 1.68(s) 1.60(s)7-CH -- 2.58(br.s) 2.8(br.s) -- --11-CH-- -- -- -- --14-CH-- 2.92(br.s) 2.95(br.s) -- --12-OCH.sub.3-- -- -- 3.68(s) 3.68(s)29-OCH.sub.3-- 3.72(s) 3.78(s) 3.76(s) 3.78(s) 1.98(s)CH.sub.3 COO1.86(s) 1.92(s) 2.02(s) 1.98(s) --Tigloyl6.93(qq) 6.94(qq) -- 6.88(qq)3'-H (7.0; 1.34) (7.0; 1.30) -- (7.0; 1.3)4'-H 1.78(dq) 1.78(dq) -- 1.75(dq) --(7.0; 1.1) (7.0; 1.1) -- (7.0; 1.1)5'-H 1.83(dq) 1.84(dq) -- 1.84(dq)(1.34; 1.1) (1.30; 1.1) -- (1.3; 1.11)__________________________________________________________________________
______________________________________.sup.13 C-NMR DATA COMPOUND 3 AND 6 (CHART-2) 3 6______________________________________C-1 70.8478(d) 72.928(d)C-2 29.5797(t) 29.577(t)C-3 68.9088(d) 67.115(d)C-4 42.3927(s) 52.3129(s)C-5 35.663(d) 36.998(d)C-6 74.9161(d) 72.215(d)C-7 76.4206(d) 74.018(d)C-8 44.9545(s) 43.335(s)C-9 44.7298(d) 48.499(d)C-10 49.8957(s) 47.760(s)C-11 103.9192(s) 100.911(d)C-12 171.6262(s) --C-13 69.9268(s) 66.917(s)C-14 69.9220(s) 69.946(s)C-15 76.2910(d) 76.147(d)C-16 24.9646(t) 25.255(t)C-17 48.8888(d) 48.132(d)C-18 18.2318(q) 18.570(q)C-19 72.5881(t) 72.928(t)C-20 83.4946(s) 83.384(s)C-21 108.8309(d) 108.545(d)C-22 107.2595(d) 107.509(d)C-23 146.8451(d) 147.074(d)C-28 77.35(t) 77.425(t)C-29 18.9414(q) 173.428(s)C-30 21.0782(q) 20.824(q)COOCH.sub.3 53.0748(q) 52.452(q)CH.sub.3 COO 169.7945(s) 169.657(s)CH.sub.3 COO 20.7701(q) 2.485(q)OTig;C-1' 166.1988(s) 166.510(s)C-2' 128.6384(s) 128.689(s)C-3' 137.1983(d) 137.941(d)C-4' 14.1673(q) 14.237(q)C-5' 11.8579(q) 11.804(q)______________________________________
According to a feature of the invention, there is provided a process for the preparation of new insecticidally active compositions containing the above referred new triterpenes including azadirachtin and its derivatives from the neem plant which process comprises:
a. grinding the parts of the neem plants to get a powder;
b. extracting the powder with a binary immiscible solvents consisting of one polar and the other non-polar solvent in the ratio of 1:2 to obtain an extract;
c. filtering the resultant extract to get a filtrate having two layers one layer containing lipids, and other containing the new triterpenes including azadirachtin and its derivatives and water soluble constituents including sugars;
d. separating the layers by known methods;
e. concentrating the layer containing triterpenes including the azadirachtin and its derivatives and water soluble constituents including sugars;
f. treating the resultant concentrate with a polar solvent and
g. filtering the resultant solution to produce a filtrate containing the mixture of new triterpenes including azadirachtin and its derivatives.
It is found that the fraction in the polar solvent phase consists of triterpenes, azadirachtin and its derivatives in the range of 40-60% along with some water soluble compounds such as sugars, glucosides, and amino acids. The non-terpenenic portion which has been found to be water soluble can easily be removed from the terpenic portion by any known methods such as by partitioning between water and water immiscibie polar solvents. Examples of water immiscible polar solvents which can be used are ethylenedichloride, chloroform, carbontetrachloride, n-butanol, isobutanol and the like. Alternatively, the triterpenic active fraction can be separated by dissolving it in polar solvents like ethylenedichloride, ethylacetate, acetone and chloroform. The final triterpene fraction obtained by this method amounts to 2-5% based on the seed powder. This fraction contains at least 35 triterpenes related to azadirachtin of which 25-30 are biologically active. The known triterpenes include salannin, gedunin, azadiradione, azadirone, salannol acetate, epoxyazadiradione, nimbandiol, salannin derivatives, salannol derivatives, azadirchtin and new derivatives of azadirachtin. All these compounds are found to exhibit insect antifeedant and growth inhibitory activities.
The lipid fraction (i.e. the layer containing the lipids) obtained during partitioning in the non-polar solvent i.e. step c) consists of mono-, di- and triglycerides of fatty acids, sulphur compounds, straight chain hydrocarbons, straight chain esters of fatty alcohols ana acids, phyosterols and their esters and less polar triterpenes and free fatty acids of the type, oleic, stearic, linoleic, arachidoic and tiglic is found to exhibit insecticidal activity against soft bodied insects and sucking pests such as aphids, mites, cotton white fly, jassids, etc. The activity of the fraction is enhanced by dissolving the total lipid fraction in a polar solvent and chilling the resultant solution to a temperature in the range of 0°-10° C. for a period ranging from 10-20 hrs. The solid separating out under the above conditions is filtered and the solvent removed from the filtrate preferably by distillation to give the active fraction. This active fraction consisting of enriched unsaturated lipids is found to constitute 8-12% based on the seeds and in the case of neem cake it is found to be 4-6%.
The liquid fraction (2 kg) was dissolved in acetone (3 liters) and the solution was chilled at 0° to -10° C. for 12 hrs. The chilled product was filtered quickly and the filtrate was concentrated by distilling acetone and the residue obtained weighed 1 kg. It consists of mostly unsaturated fatty acids, unsaturated glycerides, hydrocarbons, sulphur compounds, phytosterols (sitosterol, stigmsterol, campesterol) and less polar triterpenes such as gedunin, azadirone, zadirodione, nimbin, deacetylnmibin etc.
According to another embodiment of the present invention there is provided a process for the preparation of a new insecticidally active composition containing lipids enriched with unsaturated fats from the part of the neem plant which comprises:
a. grinding the parts of the neem plant to get a powder;
b. by extracting the powder with a mixture of two immiscible solvents consisting of one polar and other non-polar in the ratio of 1:2 to obtain an extract;
c. filtering the resultant extract to get a filtrate having two separable layers, one layer containing the lipids and the other containing the triterpenes including azadirachtin and the derivatives of azadirachtin and water soluble constituents including sugars;
d. separating the layers by known methods;
e. concentrating the non-polar solvent layer containing the lipids to obtain the total lipids and
f. dissolving the above lipids in a polar solvent and chilling the solution in the range of 0° to -10° C. for 12 hrs and filtering to produce a filtrate containing unsaturated lipids.
By way of examples the polar solvents which can be employed are chloroform, ethanol, methanol, isobutanol, n-butanol, ethylenedichloride and the like. The non-polar solvents which can be used are selected from hexane, heptane, pentane, benzene, toluene and the like.
The present invention is illustrated by the examples given below which should not be constructed to limit the scope of the invention.
EXAMPLE 1
Neem seeds which were stored at least for 2-4 months after collection were powdered and 10 kg of the powder was stirred with 30 liters of methanol:hexane (1:2) for 2 hours and filtered. The filtrate containing two layers, one of methanol and the other of hexane were separated and the solvents removed from both the layers to yield the triterpenes along with water soluble polar compounds 0.7 kg. The lipid portion weighed 1.8 kg. 0.7 kg of the methanol extract was treated with warm (about 40° C.) acetone and decanted. The clear solution was stripped off the solvent to give triterpene-rich insect control agents, 250 g.
The triterepene active fraction (120 g) was separated by using column grade Silica gel (60-120 mesh size) and acetone:pet-ether solvent mixture with increasing percentage of acetone as the elution gradient was used to collect four broad fractions A (25 g), B (32 g), C (45 g) and D (18 g).
Rechromatography of fraction D (18 g) on Silica gel using ethyl acetate-benzene with increasing polarity of ethyl acetate resulted in five broad fractions D1 (4 g), D2 (6 g), D3 (1.5 g), D4 (2 g) and D5 (4.5 g). D3 (1.5 g) fraction was again rechromatographed on Silica gel (60-120 mesh) with chloroform:methylcyanide as the eluent with the increasing percentage of methylcyanide to give the mixture of compounds (2), (4), (8), (9) and (10) along with less polar and more polar compounds. Preparative TLC on Silica gel (400 mesh) of this fraction with ethylacetate benzene (9:1) enriched the above (2), (4), (8), (9) and (10) compounds. The enriched fraction containing the above compounds was separated by preparative TLC Silica gel (400 mesh size) with chloroform:methylcyandie (5:2) as the solvent system gave each compound 75% purity. Again each compound was purified by preparative TLC (Silica gel, 400 mesh) with acetone:pet-ether (4:6) as solvent system gave the pure compounds (2), (4), (8), (9) and (10).
D 4 (2 g) fraction was again subjected to column chromatography over column grade Silica gel (80-120 mesh) using ethylacetate:benzene with increasing percentage of ethylacetate which gave a crude mixture of five more polar compounds (3) (5), (6), (7) and (11) along with the less and more polar minor components. The above crude mixture was put on preparative TLC (Silica gel, 400 mesh size) with chloroform:methylcyanide (5:2) which gave each compound in 50% pure form. Each of the above 50% pure compounds was again loaded on preparative TLC (Silica gel, 400 mesh size) with acetone:pet-ether (4:6) to enrich it to 90% purity and again each was finally purified to obtain all the more polar compounds (3), (5), (6), (7) and (11) by using ethylacetate:benzene (9:1) as solvent system on preparative TLC (400 mesh size, Silica gel).
EXAMPLE 2
Neem seeds which were stored at least for 2-4 months after collection were powdered and 10 kg of the powder was stirred with 30 liters of methanol:hexane (1:2) for 2 hours and filtered. The filtrate containing two layers, one of methanol and other of hexane were separated and the solvents removed from both the layers to yield the triterpenes along with water soluble polar compounds 0.7 kg. The lipid portion weighed 1.8 kg. 0.7 kg of methanol extract was treated with warm (about 40° C.) acetone and decanted. The clear solution was stripped off the solvent to give triterpene-rich pest control agents 250 g.
The triterpenes-active fraction (150 g) was separated by using column grade Silica gel (60-120 mesh size) and acetone:pet-ether solvent system with increasing percentage of acetone as the elution gradient to collect four broad fractions A (30 g), B (42 g), C (55 g) and D (26 g).
Rechromatography of fraction D (26 g) on Silica gel (60-120 mesh) using chloroform:methylcyanide resulted in five broad fractions D 1 (9 g), D 2 (4 g), D 3 (4 g), D 4 (5 g) and D 5 (4 g).
D 3 (4 g) fraction was again put on column for further separation over Silica gel (60-120 mesh size) with acetone:pet-ether with increasing percentage of acetone which gave the mixture of (2), (4), (8), (9) and (10) along with less and more polar constituents. Preparative TLC of this mixture on Silica gel (400 mesh size) enriched the above five compounds (2), (4), (8), (9) and (10) with ethylacetate:benzene (9:1) to 50% purity. The enriched fraction containing the above compounds was further separated by preparative TLC on Silica gel (400 mesh size) with chloroform:methylcyanide as solvent system (5:2) to give each of the above compounds in 75% purity. Again each one was purified on preparative TLC (Silica gel, 400 mesh size) with acetone:pet-ether (4:6) which gave the pure compounds.
D 4 (4 g) fraction was again subjected to column chromatography over column grade Silica gel (60-120 mesh) using chloroform:methylcyanide with increasing percentage of methylcyanide which gave a crude mixture of five more polar compounds (3), (5), (6), (7) and (11) along with the less and more polar compounds. The above crude mixture was separated on preparative TLC (Silica gel, 400 mesh size ) with ethylacetate:benzene (9:1) which gave each compound in 50% pure form. The above 50% was again loaded on preparative TLC (Silica gel, 400 mesh size) with chloroform:methylcyanide (5:2) to give 90% pure compounds and finally they were purified by preparative TLC using acetone:pet-ether (4:6) to get very pure compounds viz. (3), (5), (6), (7) and (11).
The antifeedant activity of all the compounds was evaluated as follows:
A test solution containing 20 ppm of each compound was prepared. Weighed discs of leaves were treated with the above solution and the larvae of Heliothis armigera were released on these treated leaves. A untreated control experiment was run simultaneously. The weight of the leaves after 24 hrs and 48 hrs were recorded to evaluate the antifeedant activity of the compounds. Table 1 shows antifeedant activity of compounds 3,5 and 6.
TABLE 1______________________________________Compound of % Protectionthe formula After 24 hr After 48 hr______________________________________3 50 605 50 606 75 80______________________________________
EXAMPLE 3
Neem seeds which were stored for at least 2-4 months after collection, were powdered and 10 kg of the powder was stirred with 30 liters of methanol:hexane (1:2) for 2 hrs and filtered. The filtrate containing two layers, one of the methanol and the other of hexane were separated by using a separatory funnel and the solvents removed from both the layers to yield triterpenes including azadirachtin and its derivatives along with water soluble polar compounds weighing 0.7 kg. The lipid portion weighed 1.8 kg.
0.7 kg of the aqueous methanol extract was treated with 7 liters of warm acetone (35°-40° C.) in three lots and the acetone solubles were decanted and the solvent removed to yield the triterpene active fraction weighing 250 gms. The residue (450 gms) which was insoluble in acetone was discarded. Azadirachtin content in the above triterepene active mixture was estimated by HPLC using (60:40) methanol:water 1 ml/ml C-18 reverse phase column and 215 nm UV detector. Azadirachtin peak was identified by comparing with that of authentic sample and the percentage of azadirchatin was found to be 8%.
EXAMPLE 4
Neem cake (10 kg) obtained by expelling the oil in an expeller was stirred with 90% aq. methanol and hexane (30 liters, 1:2) for 2 hrs and filtered. The aqueous methanol layer and the hexane layer were separated in a separatory funnel and the solvents removed separately to give 0.8 kg of the aqueous methanol solubles and 0.8 kg of lipid fraction respectively.
The aqueous methanol solubles 0.8 kg was shaken with 10 liters of isobutanol and water (1:1) and isobutanol layer was separated in a separatory funnel which was distilled off to give triterpene active fraction, 280 gms.
Azadirachtin content of the above triterpene active fraction using HPLC (50:50, methanol:water, 1 ml/ml C-18 reverse phase column) and the UV detector at 217 nm was found to be 10%.
EXAMPLE 5
Neem seed powder (10 kg) was extracted with stirring with a mixture of aqueous methanol (85%) and heptane (30 liters, 1:2) and filtered. The filtrate consisting of both aqueous methanol and heptane layers was separated in a separatory funnel and the solvents removed to give aqueous methanol solubles (0.75 kg) and the lipid fraction in the heptane solubles (2.0 kg).
Methanol solubles (0.75 kg) were partitioned between ethylenedichloride and water (3 liters each) and the ethylenedichloride layer was separated and concentrated to give 250 gms of triterpene active fraction. Azadirachtin content using HPLC at 215 nm UV wavelength and acetonitrile:water (60:40) 1 ml/ml C-18 reverse phase column was found to be 9%.
1. The HPLC chromatogram of the triterpene active fraction is depicted in FIG. 5.
2. The bioefficacy data generated for triterpene active fraction at 1000 ppm are given in Table 2.
TABLE 2______________________________________BIOEFFICACY DATA OF TRITERPENE ACTIVE FRACTIONDURING FIELD TRIALS ON VARIOUS CROPS ANDCOMPARISON WITH OTHER NEEM BASEDINSECT-CONTROL AGENTS.Tobacco nursery Plot size: 6 m × 1 m No. of seedlings damaged by larvae of Spodoptera litura Days after sprayingProduct 2 9______________________________________1. Triterpene active fraction 3.04 2.502. Commercial sample 1 3.27 3.443. Commercial sample 2 3.50 3.084. Commercial sample 3 4.77 5.315. Control 8.37 8.91______________________________________Mustard Plot size: 6 m × 6 mProduct Yield (Quintal/Hectare)______________________________________1. Triterpene active fraction 14.52. Commercial sample 1 13.73. Commercial sample 4 11.74. Control 9.5______________________________________Cotton Plot size: 8 m × 8 mPercentage bud damage due to spotted bollworm Erias vittella;percentage boll damage due to pink bollworm Pectinophoragossipiella and seed cotton yield (Quintal/hectare). Product % bud damage % boll damage Yield______________________________________1. Triterpene 32.1 25.4 18.9 active fraction2. Commercial 32.6 26.5 17.7 sample 13. Commercial 39.7 32.7 14.6 sample 34. Control 45.4 38.5 11.7______________________________________Safflower Plot size: 5 m × 5 mPercentage of capitula damage due to Helithis armigera and yield(Quintal/hectare)Product % Capitula damage Yield______________________________________1. Triterpene active fraction 26.5 15.42. Commercial sample 1 30.4 13.63. Commercial sample 4 36.5 12.74. Control 52.5 11.4______________________________________Sorghum Plot size: 6 m × 6 mDead heart percentage due to shootfly Atherigona Soccata, andsorghum stem borer Chilo pertellus. % Dead heart % Dead heart % Dead heart due to stem Product 21st day after 28 days borer.______________________________________1. Triterpene 21.8 32.7 10.6 active fraction2. Commercial 25.4 36.9 14.7 sample 13. Commercial 26.5 37.6 17.6 sample 34. Control 35.6 42.8 38.5______________________________________Sorghum: GRAIN AND FODDER YIELD Grain yield Fodder yield Product Quintal/hectare Tonne/hectare______________________________________1. Triterepene active 16.1 8.7 fraction2. Commercial sample 1 14.3 6.93. Commercial sample 3 12.5 6.74. Control 8.6 5.4______________________________________
EXAMPLE 6
Neem seeds which were stored for at least 2-4 months after collection were powdered and 10 kg of the powder was stirred with 30 liters of aqueous (85%) methanol:hexane (1:2) for 2 hours and filtered. The filtrate containing two layers one of methanol and other of hexane were separated and the solvents removed from both the layers to yield the triterpenes along with water soluble polar compounds 0.7 kg and 1.8 kg of the lipid fraction respectively.
The lipid fraction (1 kg) was dissolved in acetone (1.5 liters and chilled to 0° to -10° C. for 12 hrs. The solid separated was filtered at 0° C. and the filtrate containing the unsaturated lipids was concentrated to give the lipid-active fraction, 0.5 kg. The saturated fats were used for other purposes.
EXAMPLE 7
Neem cake obtained by the expelling oil in an expeller (20 kg) was stirred with 85% aqueous methanol and hexane (60 liters) (1:2) for three hours and filtered. The aqueous methanol layer and the hexane layer were separated and solvent removed separately to give 1.6 kg of mixture of triterpenes and water soluble polar compounds and 1.6 kg of lipid fraction.
The lipid fraction (1 kg) was dissolved in 1 liter of ethylene dichloride and chilled to 0° to -10° for 12 hrs and the solid separated was filtered. The filtrate containing the unsaturated lipids were concentrated to give the lipid active fraction 0.450 kg. The saturated fats were used for other purposes.
EXAMPLE 8
Neem seeds which were stored at least for 2-4 months after collection were powdered and 10 kg of the powder was stirred with 30 liters of methanol:hexane (1:2) for 2 hours and filtered. The filtrate containing two layers one of methanol and other of hexane were separated and the solvents removed from both the layers to yield the triterpenes along with water soluble polar compounds 0.7 kg and 1.8 kg of the lipid fraction respectively.
The lipid fraction (1 kg) was dissolved in 1 liter of ethylacetate and chilled at 0° to -10° for 12 hrs. The solid separated was removed by filtration at 0° and the filtrate which contained unsaturated lipids was concentrated to give the lipid active fraction, 0.6 kg. The saturated fats were used for other purposes.
The bioefficacy data generated during field trials at 400 ppm with lipid-active fraction on different aphids on various crops are given in Table 3 which also also shows a comparative bioefficacy with those of some neem pesticides.
TABLE 3______________________________________BIOEFFICACY DATA OF LIPID-RICH ACTIVE FRACTIONDURING FIELD TRIALS AGAINST DIFFERENT APHIDS ONVARIOUS CROPS.(Number denotes the average number of apids/5 plants).______________________________________Day after Lipid activespray Fraction Margosan-O Neemark______________________________________Precount 48.7 48.2 46.21st spray1 40.0 31.2 40.22. 31.2 27.7 30.24. 18.7 27.0 35.210. 16.2 28.2 37.714 22.2 30.0 37.015 second spray1 17.7 24.7 20.22 15.0 18.5 25.04 15.2 27.2 27.710 16.2 35.7 30.514 22.2 38.2 37.215 Third spray1 17.2 31.2 30.22 20.2 27.7 40.74 22.0 29.5 47.010 22.7 31.7 57.014 23.7 37.5 57.015 Fourth spray1 17.7 22.2 47.22 20.7 27.5 45.04 22.5 30.7 48.210 22.5 30.0 56.214 22.0 35.0 59.0______________________________________Mustard Aphid Lipaphis erysimi; 1 plot size 6 m × 6 mMustard sawfly: Athalia proxima 2. Lipid activeDay after Fraction Margosan-O Jawanspray 1 2 1 2 1 2______________________________________Precount 38 11 34 13.2 38 11First spray1 20 22 282 17 18 264 15 18 3010 15 18 3214 16 21 3715 Second spray1 12 7 17 7 30 102 12 7 17 7 27 104 10 7 15 7 29 1010 11 8 15 8 31 1014 12 8 16 8 34 1115 Third spray1 13 5 10 6 35 92 13 5 11 6 30 94 15 6 11 7 32 910 15 7 11 7 37 914 17 7 13 7 39 1015 Fourth spray1 12 5 10 6 27 82 10 5 11 6 25 84 11 6 12 7 29 910 11 6 12 7 34 914 13 6 15 8 39 11______________________________________Safflower Aphid: Daetynotus carthami Plot size 5 m × 5 mDay after Lipid activespray Fraction Margosan-O Jawan______________________________________Precount 37 39 37First spray1 24 22 302 21 17 274 17 17 2510 18 18 2114 18 15 3715 Second spray1 8 8 282 6 8 204 6 9 1810 7 13 1914 6 14 2715 Third spray1 3 9 202 3 9 174 4 9 1710 6 11 2214 6 13 2615 Fourth spray1 1 7 182 4 7 174 4 11 1110 6 14 2214 7 16 26______________________________________Sorghum Apid: Schizophis Sorshiella Plot size 6 m × 6 mDay after Lipid activespray Fraction Margosan-O Neemark______________________________________Precount 31.5 36.5 39.5Third spray1 16.2 30.2 30.22 16.0 26.2 27.75 17.2 24.2 22.510 18.2 26.7 28.514 19.2 29.5 29.215 Fourth spray1 13.5 21.7 21.52 14.5 21 17.75 14.0 23.7 21.510 15.2 26.3 24.714 15.5 28.2 29.2______________________________________ | The invention discloses novel triterpene derivatives of azadirachtin of the formulae 2 to 11 of the drawings and a process for isolating new triterpene derivatives of azadirachtin from the various parts of the neem plant(Azadirachta indica A-Juss), which process comprises grinding the parts of the neem plant to get a powder, extracting the powder with a binary immiscible solvent consisting of one polar and another non-polar solvent in a ratio of 1:2 to obtain an extract, filtering the extract to get a filtrate having two layers, one layer containing lipids and the other layer containing the new triterpene derivatives of azadirachtin and water soluble constituents including sugars, separating the layers by known methods, concentrating the layer containing the new triterpenes of the formulae 2-11 including derivatives of azadirachtin and water soluble salts, treating the resultant concentrate with a polar solvent and if necessary, warm the concentrate having the solvent, and filtering/decanting the resultant solution to produce a filtrate containing the mixture of the new triterpene derivatives of azadirachtin. The lipid layer is concentrated in any known manner, the lipid concentrate is treated with a polar solvent, chilled to a temperature of 0° to -10° C. and filtered to produce a filtrate containing lipids. The new triterpene derivatives of azadirachtin are useful in suppressing the insect pest population below the econcmic threshold level by their antifeedant and growth inhibitory activities. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/677,559 filed on May 3, 2005.
BACKGROUND OF THE INVENTION
[0002] A. Field of the Invention
[0003] The field of the present invention relates generally to apparatuses and devices used for supporting clothes, wash clothes, towels or other objects in or near a shower or bath area. More specifically, this invention relates to such apparatuses and devices that are configured to removably but securely attach to a hard, non-porous wall or other generally smooth surface. Even more specifically, this invention relates to such apparatuses and devices that utilize one or more mechanically activated vacuum or suction cups to removably attach to the wall or other surface.
[0004] B. Background
[0005] The walls of most shower and bath areas are at least partially covered or otherwise provided with generally non-porous materials to protect the underlying wall from water that is splashed or sprayed during the shower or bath. In particular, due to the nature of the configuration of the shower head and spray therefrom, indoor shower areas nearly always have the walls covered with a substantially non-porous material to protect the drywall or other water damagable wall material underlying the covering material. Common materials utilized for shower walls include tile, marble, plastics (such as PVC and other plastics), fiberglass, glass and various composite materials. In addition to being substantially non-porous, shower walls are generally configured, for both aesthetics and comfort reasons, with a hard and relatively flat, smooth surface. While such surfaces are generally attractive and suitable for use as a shower enclosure, they are known to have certain limitations with regard to installing apparatuses or devices on the shower wall area. For instance, it is generally difficult to attach a hook, nail, screw or other attaching mechanism to or through the wall of a shower or bath area, as one normally does to other walls, due to the materials utilized for shower and bath enclosures. In addition to being difficult to accomplish, attempting to pass such an attaching mechanism to or through such walls risks cracking, chipping or otherwise damaging the wall. As a result, most people are unable or unwilling to utilize these attaching mechanisms to attach otherwise useful or necessary apparatuses or devices to their shower wall. If the shower or bath area is not in their own home, such as showers at gyms, hotels and the like, the user is neither allowed nor desirous to permanently attach an attaching mechanism to the surrounding or nearby wall.
[0006] One device that would be particularly useful for attachment to a shower wall is a bar type of apparatus which a person could use to hang a wash cloth or like objects inside the shower or bathing area or their towel, robe, clothes or the like at or nearby while taking a shower or bath. Instead, people generally have to hang these objects well outside the shower or bath area or over the shower door or low wall and hang the wash cloth over the shower head, soap dish or other projection inside the shower or bath area. Unfortunately, with regard to the placement of a towel in a shower area, particularly showers in gyms and the like, the area for hanging the towel is either out of easy reach or in an area where it is likely to get wet from the shower spray. Naturally, when it is out of reach it is also often out of the person's sight. When the person is done with the shower and desires to dry off, he or she usually has to either reach for the towel or have to step out of the shower enclosure while wet to get the towel and begin drying off. As a result, it would be useful to have an apparatus that is suitable for supporting a towel on a shower wall, particularly one that is removably attached so that it can be placed where desired and suitable for use in locations not belonging to the user, including showers in gyms, motels, hotels or rental units.
[0007] Although some manufactures texture the floor of the shower or the user utilizes a non-slip floor covering, which can provide some degree of resistance to slipping, the walls are nearly always left very smooth. In fact, most shower areas have very few, if any, non-plumbing projections into the shower area that can be used to stabilize a person. An exception to this are those showers that are primarily configured for disabled persons, which are typically provided with one or more fixedly attached shower bars to help support the disabled person while he or she is showering or getting in and out of the bath. However, as well known, the vast majority of shower enclosures are not provided with any type of support/stabilizing bar and, as discussed above, the materials used for shower enclosure makes it difficult to add a bar to the shower.
[0008] A variety of hook or hook-like devices are available for attachment to the shower wall which can, to some extent, be used for hanging a towel or like object inside a shower enclosure. Generally, these and other devices utilize a single suction cup that is configured to adhere to the wall by pushing the cup base against the wall, usually while it or the wall is wet. Some of these hook devices include a cam-type of locking mechanism that is configured to better secure the hook device to the wall. As is well known, however, these suction cup devices generally do not work very well and are typically not suitable for use with a bar that is intended to support much weight. For instance, such devices typically do not have enough suction or gripping strength to support the weight of the typical towel, robe or clothes and are not useful at all for stabilizing a person in the shower area. Even if the typical shower suction cups can initially support the weight of a towel, they generally lack sufficient suction power to maintain their attachment to the wall, particularly in light of the soap, water and steam which are present on shower enclosure walls.
[0009] In general, the use of mechanically activated suction cups as a gripping device to ease the handling of large pieces of glass, sheet metal, plastic, fiberglass, polished stone or like materials is well known. Typical, mechanically activated suction hand cups comprise a handle portion with a suction cup member that is activated by operating a lever to engage the suction cup against the material the user desires to lift or otherwise handle. Suction cup assemblies generally comprise a rubber suction cup member that is pressed against the material such that when the lever is activated a suction force is created between the suction cup and the material, thereby allowing the user to utilize the handle to lift or move the object to which the suction cup is now attached. To release the suction and disengage the object from the suction cup, the user moves the lever in the opposite direction. These devices are not configured for use as an object supporting bar in a shower or bath area.
[0010] What is needed, therefore, is a shower bar that is configured to be securely, yet removably attached to the typical wall surface utilized for shower and bath enclosures. The preferred shower bar apparatus should be configured to attach to a shower or bath wall with enough suction or gripping force to support a wash cloth, shower-sized towel, robe, clothes or other materials on the shower wall without slipping therefrom. The preferred shower bar apparatus will be easy to attach and remove from the shower wall surface. Preferably, the shower bar apparatus will be aesthetically pleasing and relatively inexpensive to manufacture.
SUMMARY OF THE INVENTION
[0011] The removably attachable shower bar of the present invention provides the benefits and solves the problems identified above. That is to say, the present invention discloses a shower bar that is configured to be removably, but securely attached to the wall of a shower or bath enclosure to support a wash cloth, towel, robe, clothes or other materials in or near the shower or bath. The shower bar of the present invention can be easily attached and removed from various places in the shower or bath enclosure as determined by the user, such as inside the shower enclosure or on a wall next to the shower enclosure. The shower bar of the present invention provides sufficient attachment force that, if need be, it can help stabilize a person in the shower so as to prevent or check a person from slipping and falling in the enclosure, thereby reducing the likelihood the person will suffer severe or life-threatening injury from a fall. The shower bar of the present invention can be configured to have an aesthetically pleasing appearance and be relatively inexpensively manufactured.
[0012] In one general aspect of the present invention, the shower bar comprises a support bar, activator arm and one or more suction cup assemblies that cooperate together to attach to a surface, such as a wall of a shower or bath enclosure. In a preferred embodiment, the support bar has a first end section at a first end, a second end section at a second end and a center section that interconnects the first end section and the second end sections. The support bar has a channel, which in the preferred embodiment is downwardly directed, that receives the activator arm when the shower bar is attached to the surface. The first and second end sections are both disposed inwardly towards the surface of the tub or shower in order to dispose the center section of the support bar in a spaced apart relation to the surface. In one configuration, the support bar is configured in a substantially U-shape having a first end and a second end, at which are located the suction cup assemblies. The activator arm is in pivotal relation with the support bar such that the upward or downward movement thereof either engages or disengages the shower bar from the surface. Each of the suction cup assemblies have a cup housing, a suction member at an outwardly disposed open second end of the cup housing and a mechanism for disposing the cup housing against the suction member. The suction member, which generally will be made out of rubber or the like, is configured to sealably connect to the cup housing so as to define a suction chamber therein and securely attach the shower bar to the surface. In the preferred embodiment, the disposing mechanism comprises a pivot pin that interconnects the ends of the activator arm with one end of an activation rod. The other end of the activation rod is attached to the suction member. In one embodiment, a plate member interconnects the end of the activation rod and the suction member.
[0013] In operation, the user places the suction member against the surface at the location he or she desires to have a shower bar with the activator arm in the downward or disengaged position. To secure shower bar to the surface (i.e., shower wall), the user merely places activator arm in the engaged position by raising the activator arm upward into the support bar channel. The upward movement of the activator arm pushes the second end of the cup housing against the suction member and creates the suction force in the suction chamber to hold shower bar in place. To remove the shower bar, the user engages a releasing mechanism, which in a preferred embodiment comprising an arm release hole on the upper side of the support bar, by placing an elongate object into the arm release hole and pushing downward to initiate the downward motion of the activator arm. This downward motion displaces the second end of the cup housing away from the suction member and releases the shower bar from the surface.
[0014] Accordingly, the primary objective of the present invention is to provide a removably attachable shower bar that provides the advantages discussed above and overcomes the disadvantages and limitations associated with presently available shower wall attachment devices.
[0015] It is also an important objective of the present invention to provide a removably attachable shower bar that securely but removably attaches to the smooth, generally non-porous surfaces utilized in and around shower and bath areas.
[0016] It is also an important objective of the present invention to provide a removably attachable shower bar that sufficiently attaches to generally non-porous shower and bath walls to support the weight of a wash cloth, towel, robe, clothes and the like without slipping down or otherwise disengaging from the wall.
[0017] It is also an important objective of the present invention to provide a removably attachable shower bar that comprises a support bar which is integrally connected to a pair of mechanically activated suction cups and pivotal activator arm that is operatively connected to the suction cups so as to removably secure the bar to the wall of the shower or bath enclosure surface or release the suction cups therefrom.
[0018] It is also an objective of the present invention to provide a removably attachable shower bar that can be sufficiently attached to a shower wall to stabilize a person so as to prevent or slow a fall in the shower.
[0019] It is also an objective of the present invention to provide a removably attachable shower bar that has an aesthetically pleasing appearance and which can be manufactured relatively inexpensively.
[0020] The above and other objectives of the present invention will be explained in greater detail by reference to the attached figures and the description of the preferred embodiment which follows. As set forth herein, the present invention resides in the novel features of form, construction, mode of operation and combination of processes presently described and understood by the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In the drawings which illustrate the preferred embodiments and the best modes presently contemplated for carrying out the present invention:
[0022] FIG. 1 is a perspective view of the removably attachable shower bar configured according to the principles of a preferred embodiment of the present invention shown attached to a wall surface;
[0023] FIG. 2 is a cross-sectional top view of the removably attachable shower bar of FIG. 1 taken through the support bar showing the components of the activator arm, activation mechanism and suction cup assemblies;
[0024] FIG. 3 is a cross-sectional side view of the removably attachable shower bar of FIG. 1 taken through one of the suction cup assemblies showing the activator arm and activation mechanism in the disengaged position;
[0025] FIG. 4 is a bottom view of the support bar and integrally formed cup housing of a preferred embodiment of the removably attachable shower bar of the present invention;
[0026] FIG. 5 is a side view of a preferred configuration for the suction cup base used with the removably attachable shower bar of the present invention; and
[0027] FIG. 6 is a top view of a preferred configuration for the activator arm used with the removably attachable shower bar of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] With reference to the figures where like elements have been given like numerical designations to facilitate the reader's understanding of the shower bar of the present invention, the preferred embodiments of the present invention are set forth below. As will be recognized by those skilled in the art, the enclosed figures and drawings are merely illustrative of the preferred embodiments and represent several different ways of configuring the present invention. Although specific components, materials, configurations and uses are illustrated, it should be understood that a number of variations to the components and to the configuration of those components described herein and in the accompanying figures can be made without changing the scope and function of the invention set forth herein.
[0029] A removably attachable shower bar that is manufactured out of the materials and pursuant to one embodiment of the present invention is shown generally as 10 in FIGS. 1 through 3 . As shown in these figures, shower bar 10 generally comprises a support bar 12 , a pair of suction cup assemblies 14 and an activator arm 16 that are configured to securely, but removably attach shower bar 10 to a generally hard smooth surface, shown as 18 in FIG. 1 , such as the walls of a shower or bath enclosure or the sides of a bathtub (as may be desired by the user). As described in more detail below, suction cup assemblies 14 are mechanically activated suction cups that are activated by the pivotally attached activator arm 16 so as to securely engage surface 18 and to provide an apparatus to support a wash cloth, towel, robe, clothes or other objects that may be accessed by a person utilizing the shower or bathtub. As shown in FIGS. 1 through 3 , the suction cup assemblies 14 of the shower bar 10 of the present invention generally comprise cup housing 20 and cup base 22 , which are configured to provide the suction force necessary to securely attach shower bar 10 to surface 18 so that the user can utilize shower bar 10 to support one or more objects. In the preferred embodiment, as shown in the figures, support bar 12 and cup housing 20 are integrally formed and configured from a sturdy material, such as molded plastic. The dimensions and configuration of the support bar 12 and cup assemblies 14 must be sufficient in length and circumference to provide the desired amount of suction against surface 18 and to provide the user with the desired amount of space to hang his or her objects (as described above).
[0030] As shown in FIG. 4 , which is a view of the underside of a preferred embodiment of support bar 12 and cup housing 20 , support bar 12 is formed with an open channel 24 for receiving activator arm 16 therein when shower bar 10 is secured to surface 18 . In addition, cup housing 20 is formed with suction chamber 26 for housing the operating components of the cup assemblies 14 . As explained in more detail below, support bar 12 has a release mechanism, such as arm release hole 28 , that is configured to allow the user to initiate the downward movement of activator arm 16 so as to release shower bar 10 from surface 18 . Although the preferred embodiment utilizes channel 24 , primarily to provide a more unified and aesthetically pleasing shower bar 10 , support bar 12 can be solid and activator arm 16 can be configured to abut against the underside of support bar 12 instead of inside channel 24 .
[0031] As shown in FIGS. 2 and 3 , activator arm 16 is in pivotal relation with support bar 12 and cup base 22 operatively attaches to activator arm 16 by way of activation rod 30 . The first end 32 of activation rod 30 is provided with a first activation rod hole 34 for receiving pivot pin 36 through a cooperatively configured second pivot pin hole 38 in the ends of support bar 12 near where it connects to cup housing 20 (as best shown in FIG. 4 ). Pivot pin 36 secures activation rod 30 , and therefore cup base 22 , to activator arm 16 in a manner that allows activator arm 16 to pivot between the engaged position shown in FIG. 1 to the disengaged or released position shown in FIG. 3 . As shown in FIG. 2 , which is a cross-section view of shower bar 10 through a position just above the center of suction cup assemblies 14 , pivot pin 36 passes through the first end 40 and second end 42 of support bar 12 and first end 44 and second end 46 of activator arm 16 to obtain the pivotal relationship between support bar 12 and activator arm 16 necessary for the mechanical activation of suction cup assemblies 14 . As best shown in FIGS. 2 and 4 , activator rod 30 passes from suction chamber 26 of cup housing 20 to inside channel 24 for connection to pivot pin 36 , which connects to activator arm 16 , by way of a rod hole 48 at the first end 50 of cup housing 20 . The second end 42 of activation rod 30 is attached to the suction member 52 at the second end 54 of cup housing 20 , as best shown in FIG. 5 . In a preferred embodiment, a plate member 56 interconnects the second end 42 of activation rod 30 with the suction member 52 of cup base 22 . In the preferred embodiment, plate member 56 is a hard plastic material.
[0032] In the preferred embodiment, shown in the figures, shower bar 10 is configured in a generally U-shape with support bar 12 having a first end section 58 at first end 40 , second end section 60 at second end 42 and center section 62 disposed between first 58 and second 60 end sections (as well as first 40 and second 42 ends), as best shown in FIG. 2 . Support bar 12 is configured to dispose the center section 62 thereof in spaced apart relation to surface 18 , as shown in FIG. 1 , so the user may easily hang or otherwise place the objects over support bar 12 . The first end 50 of cup housing 20 of each suction cup assembly 14 is attached to the first 40 and second 42 ends of support bar 12 . In one preferred embodiment, shown in FIG. 4 , cup housings 20 are integral with support bar 12 . The suction member 52 of each suction cup assembly 14 is disposed at the second end 54 of cup housings 20 , which are disposed outwardly from support bar 12 , so as to define suction chamber 26 when suction member 52 is sealably connected or engaged with second end 54 of cup housings 20 (which occurs through the upward movement of activator arm 16 into channel 24 of support bar 12 ). As stated above, the mechanically activated suction cups for the shower bar 10 of the present invention comprises a mechanism for disposing the second end 54 of cup housings 20 against suction member 52 of each suction cup assembly 14 . In the preferred embodiment, the suction cup assembly 14 disposing mechanism comprises the pivot pin 36 and activation rod 30 , with the pivot pin 36 connecting the first end 32 of activation rod 30 to one end of activator arm 16 and the second end 42 of activation rod 30 connected to suction member 52 , as best shown in FIGS. 2 and 3 . In the preferred embodiment of the present invention, activator arm 16 is also configured in a generally U-shaped configuration, having a first end section 64 at first end 44 , second end section 66 at second end 46 and a center section 68 disposed therebetween, as best shown in FIG. 6 . The first 44 and second 46 ends of activator arm 16 have a third pivot pin hole 70 for receiving pivot pin 36 and an activation rod slot 72 for receiving activation rod 30 therethrough, as also best shown in FIG. 6 . As best shown in FIG. 2 , activation rod 30 passes through first 44 and second 46 ends of activator arm 16 and is attached to activator arm 16 by the insertion of pivot pin 36 through third pivot pin hole 70 and first activation rod hole 34 .
[0033] In one exemplary embodiment, support bar 12 and cup housing 20 are made from an injection molded plastic. Although other dimensions can be used, in one embodiment support bar 12 is approximately eight to eighteen inches in width, cup housing 20 is approximately three and one-half inches in width and the distance from cup base 22 to the outside edge of support bar 12 is approximately four inches. Suction member 52 can be approximately three inches in diameter and one-eighth of an inch thick and be made out of a rubber or vinyl material. Activation rod 30 can be square, rectangular, round or other shapes. In one configuration, activation rod 30 is approximately one-half inch wide and one and three-fourths of an inch long with a one-fourth inch first pivot pin hole 34 for pivot pin 36 . In use, suction member 52 is pressed against surface 18 at the location desired by the user with activator arm 16 in the downward or disengaged position shown in FIG. 3 . Activator arm 16 is then pivotally raised from the position shown in FIG. 3 to the upward or engaged position shown in FIG. 1 (i.e., activator arm 16 disposed in channel 24 of support bar 12 ). As activator arm 16 pivots upward, it pulls activation rod 30 in the direction away from surface 18 and causes cup housing 20 , by force from first 44 and second 46 ends of activator arm 16 against first end 50 of cup housing 20 , to press against suction member 52 so as to create a substantial suction force against surface 18 to hold support bar 10 in place thereon. The action of suction member 52 against surface 18 tightly holds activator arm 16 in channel 24 of support bar 12 . When the user desires to remove shower bar 10 from surface 18 or move it to another location, he or she merely pushes an elongated member through arm release hole 28 against activator arm 16 to initiate a pivotal downward movement of activator arm 16 . As activator arm 16 pivots downward, it pushes activation rod 30 towards surface 18 , causing suction member 52 to release the suction against surface 18 . If desired, shower bar 10 can be provided with a quick release button or other mechanism that the user pushes to initiate the downward movement of activator arm 16 to disengage shower bar 10 . When released, shower bar 10 can be removed or moved to another location, where it can be attached to the new surface as described above.
[0034] While there are shown and described herein a specific embodiment of the invention, it will be readily apparent to those skilled in the art that the invention is not so limited, but is susceptible to various modifications and rearrangements in design and materials without departing from the spirit and scope of the invention. In particular, it should be noted that the present invention is subject to modification with regard to the dimensional relationships set forth herein and modifications in assembly, materials, size, shape, and use. For instance, there are components described herein that can be replaced with equivalent functioning components to accomplish the objectives of the present invention. One such modification is the use of different materials than those set forth herein. | A shower bar is provided for secure but removable attachment to a surface, such as a wall in a shower or bath area. The shower bar has a support bar connected to a pair of mechanically activated suction cup assemblies and a pivotal activator arm that operatively engages the suction cup assemblies to hold the shower bar to the surface of the wall or release it therefrom. The support bar has a channel that receives the activator arm therein when the shower bar is secured against the surface. Each of the suction cup assemblies has a cup housing that seals against a suction member to define a suction chamber in the cup housing. Pivot pins at the ends of the activator arm connect to activation rods that operatively engage the cup housing against the suction member. An arm release hole is provided to release the shower bar from the surface. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to previously-filed provisional application Ser. No. 60/785,322 filed Mar. 23, 2006, which is relied on and incorporated herein fully by reference.
BACKGROUND OF THE INVENTION
Many homes have a separate facility or general area for the purpose of cleaning laundry, such as clothes, curtains, linens, dish clothes, and towels. This laundry facility or area typically contains a washer and dryer, clothes racks, and detergents and cleaners. In many homes, the process of washing laundry typically includes: (1) moving dirty laundry from a bedroom or bathroom to the laundry facility; (2) washing and drying the laundry; (3) placing the clean laundry into a container so that it can be returned to its respective bedroom or bath room; (4) folding or hanging the laundry; and (5) placing the laundry in its proper place in the room (such as in a closet or dresser) where it is stored prior to use.
Traditionally, the laundry process required a person to move throughout the house back and forth from the laundry facility to complete his or her task. This process also required significant movement of laundry, as well as handling and folding, increasing both labor and time.
Consequently, there is a need for an invention that can reduce the amount of time required by the person cleaning the laundry and returning it to its proper place in the residence, while at the same time improve the quality and condition of the laundry when returned or stored.
SUMMARY OF THE INVENTION
The present invention provides improved household laundry functions which decrease the overall time and effort of the laundry process of collecting dirty laundry, washing, drying, hanging, and storing laundry. This present invention also improves the quality of the laundry output.
One embodiment of the present invention provides a building structure, typically a house, preferably configured to include five structural elements.
The first structural element is composed of closets, accessible from two sides, herein referred to as “dual access closets.” The second and third structural elements relate to the laundry facility and/or the hallway, herein referred to as “the specifically configured laundry facility” and the “the specifically configured hallway,” respectively. These elements may also be referred to as the “laundry facility” and “hallway” for ease of explanation. The second structural element is the configuration of the laundry facility and the hallway in a manner that allows full and efficient access to the dual access closets. The third structural element is the narrow width configuration of the laundry facility and hallway.
A fourth structural element is the configuration of the rooms where the laundry will be used, such as bedrooms and dressing rooms, in a manner that allows full and efficient access to the dual access closets. The fifth element of the present invention is the placement of the following in relationship to each other: the laundry facility, the hallway, the dual access closets, and the rooms where the laundry will be used, such as bedrooms, dressing rooms, bathrooms and kitchen.
In one embodiment of the present invention, the specifically configured laundry facility is centrally located among a majority of rooms where the laundry will be used, such as bedrooms, dressing rooms, bathrooms, and kitchen, and is separated from at least some of the adjoining rooms by walls containing dual access closets. The dual access closets can be accessed from both sides: the laundry facility on one side and the adjacent room(s) on the other. Dirty laundry can be collected with minimal or no steps from the closet(s) adjacent to the laundry facility and placed in the washer. Of chief benefit, clean laundry can be hung or shelved from the washer and/or dryer into the closet(s) adjacent to the laundry facility with minimal or no steps. The clean laundry is conveniently accessible to the end-user(s) without any further movement of laundry.
Additionally, the building structure is preferably configured so that rooms that are not directly adjacent to the specifically configured laundry facility, such as bedrooms and bathrooms, are located on a hallway common to the specifically configured laundry facility and the non-adjacent rooms. The specifically configured hallway is configured in a manner so that the wall dividing the non-adjacent rooms from the hallway may include dual access closets accessible from the common hallway on one side and the respective non-adjacent room on the other. The non-adjacent rooms are placed near the laundry facility in order to minimize steps taken in the laundry process.
In a variation of the present invention, also utilizing the above-described five structural elements, the laundry facility is combined with the hallway. Thus, most of the rooms where the laundry is used, such as bedrooms and dressing rooms, are adjacent to the hallway, as well as the laundry equipment. In the presently described embodiment, the specifically configured hallway is used instead of the specifically configured laundry facility. The specifically configured hallway is configured in a manner so that the wall dividing the rooms from the hallway may include dual access closets accessible from the hallway on one side and the respective room on the other.
A significant advantage of the present invention is that the occupants of the bedrooms, dressing rooms, and/or bathrooms are not disturbed during the laundry process of collecting dirty laundry and returning clean laundry.
In another embodiment, the laundry facility is placed adjacent to the kitchen; or in the case of a two story structure, the kitchen is adjacent to the stairway, the top of which is either adjacent to or in close proximity to the laundry facility on the second floor. Laundry and meal preparation are two of the most time-consuming household processes and are frequently performed simultaneously. Therefore, locating these two rooms adjacent to each other benefits both processes. While many homes locate these two rooms adjacent to each other, the present invention offers the advantage of allowing the meal preparer to more quickly return to the kitchen due to the efficiencies of the laundry process. Alternately, if the laundry processor is an office worker or other type worker, the office or other type room may be placed adjacent to the laundry facility.
By way of explanation, several terms used within the present description are defined as follow. As used herein, reach-in closets are closet that do not have an aisle; clothes and other laundry items are removed and stored (hung and shelved) by standing outside of the closet. Walk-in closets, on the other hand, do have an aisle; clothes and other laundry items are removed and stored (hung and shelved) by entering (or walking into) the closet. Laundry movement efficiency, as used herein, refers to the reduction of steps required to collect dirty laundry and return clean laundry to closets, cabinets, shelves, etc. where it will be stored and used in order to reduce the time and effort required in the household laundry process of collecting dirty laundry, washing, drying, hanging, and storing laundry. The terms non-adjacent rooms, non-adjacent dual access closets, and non-adjacent dual access linen cabinets, as used herein, refer to rooms, closets, and cabinets not adjacent to the laundry facility.
Other objects, features, and aspects of the present invention are provided by various combinations and sub-combinations of the disclosed elements, as well as methods of utilizing the same, which are discussed in greater detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
A full and 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, which makes reference to the accompanying figures, in which:
FIG. 1 is a top schematic view of a building structure arranged in accordance with an embodiment of the present invention;
FIG. 2 is a top schematic view of another building structure arranged in accordance with an embodiment of the present invention;
FIG. 3 is a top schematic view of a building structure arranged in accordance with an alternate embodiment of the present invention;
FIG. 4 is a top schematic view of a building structure arranged in accordance with an alternate embodiment of the present invention;
FIG. 5 is a top schematic view of another building structure arranged in accordance with an alternate embodiment of the present invention;
FIG. 6 is a top schematic view of another building structure arranged in accordance with an alternate embodiment of the present invention;
FIG. 7 is a top schematic view of another building structure arranged in accordance with an alternate embodiment of the present invention;
FIG. 8 is a top schematic view of another building structure arranged in accordance with an alternate embodiment of the present invention;
FIG. 9 is a top schematic view of another building structure arranged in accordance with an alternate embodiment of the present invention;
FIG. 10 is a top schematic view of another building structure arranged in accordance with an alternate embodiment of the present invention;
FIG. 11 is a top schematic view of another building structure arranged in accordance with an alternate embodiment of the present invention;
FIG. 12 is a top schematic view of another building structure arranged in accordance with an alternate embodiment of the present invention;
FIG. 13 is a top schematic view of a laundry facility of the building structure of FIG. 1 ;
FIG. 14 is a top diagrammatic view of fans used in combination with the laundry facility of FIG. 13 ;
FIG. 15 is a top schematic view of a dual access closet of the building structure of FIG. 1 ; and
FIG. 16 is a top schematic view of a dual access closet of a building structure in accordance with an alternative embodiment of the present invention.
Repeat use of reference characters in the present drawings is intended to represent same or analogous features or elements of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to 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 modifications and variations can be made in the present invention without departing from the scope or spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on or in another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. Furthermore, the embodiments also contain labels of rooms (e.g., “master bedroom”) showing a plausible configuration of the building structure, but it should be understood that these labels are for ease of understanding, and the invention should not be limited to the designs shown and described herein.
FIG. 1 illustrates a building structure 10 constructed in accordance with an embodiment of the present invention. Building structure 10 comprises a number of other structures including a master bedroom 12 , a laundry facility 14 , bedrooms 16 and 18 , kitchen 20 , and family room 22 . A hallway 24 is adjacent to and connects laundry facility 14 , bedrooms 16 and 18 , and master bedroom 12 . Master bedroom 12 includes a master bath 26 and a dual access closet 28 . Bedrooms 16 and 18 include dual access closets 30 and 32 , respectively, and are connected by a bath 34 located between the bedrooms. Baths 26 and 34 include dual access linen closets 36 and 38 , respectively. Laundry facility 14 includes laundry equipment 40 , and, in another embodiment, may include additional laundry equipment 42 .
In another embodiment illustrated in FIG. 2 , building structure 10 consists of two stories, a first floor 44 and a second floor 46 . First floor 44 and second floor 46 are connected by a stairway 48 .
Referring to FIGS. 1 and 2 , the first structural element presents as dual access closets 28 , 30 , and 32 , as well as dual access linen cabinets 36 and 38 . The second structural element configures laundry facility 14 in a manner that allows full and efficient access to the dual access closet 28 from the laundry facility. Thus, the length and height dimensions of the wall in laundry facility 14 common to dual access closet 28 are configured to equal or exceed the length and height dimensions of the opening for dual access closet 28 .
To accommodate the non-adjacent rooms and closets, the second structural element configures hallway 24 to allow full and efficient access to dual access closets 30 and 32 from the hallway. Thus, the height of the wall in hallway 24 common to dual access closets 30 and 32 equals or exceeds the height of the respective opening of dual access closets 30 and 32 . The length of specifically configured hallway 24 equals or exceeds the combined length of bedrooms 16 and 18 and bath 34 .
The third structural element presents as a relatively narrow configuration of specifically configured laundry facility 14 . This narrow configuration allows dirty laundry to be collected from dual access closet 28 and made available to laundry equipment 40 and 42 with minimal or no steps. Of chief benefit, this relatively narrow configuration allows clean laundry to be hung or stored into dual access closet 28 from laundry facility 14 with minimal or no steps. While a width of only three feet between laundry equipment 40 and 42 and closet 28 is sufficient for normal laundry processes and provides the greatest degree of laundry movement efficiency, however, a width of more than three feet may be preferred and is acceptable in the present invention. Likewise, specifically configured hallway 24 presents as a narrow configuration (approximately three to four feet) in order to increase laundry movement efficiency for the non-adjacent rooms. It should be understood by one of ordinary skill in the art that laundry facility 14 and hallway 24 , as well as the other structures included in building structure 10 , may be constructed having other dimensions smaller or larger without departing from the scope and spirit of the present invention.
The fourth structural element configures master bedroom 12 and bedrooms 16 and 18 in a manner that allows full and efficient access to respective dual access closets 28 , 30 , and 32 . Thus, the length and height dimensions of the respective walls in bedrooms 12 , 16 , and 18 common to respective dual access closets 28 , 30 , and 32 equal or exceed the length and height dimensions of the respective closets' openings in order to allow full and efficient access to the closets by the occupant(s) of each respective bedroom.
The fifth structural element presents as the placement of specifically configured laundry facility 14 in relationship to dual access closet 28 , and the placement of specifically configured master bedroom 12 in relationship to the closet. Laundry facility 14 is located on the side of dual access closet 28 opposite master bedroom 12 . Master bedroom 12 is located on the side of dual access closet 28 opposite laundry facility 14 . As a result, dual access closet 28 is located between specifically configured laundry facility 14 and specifically configured master bedroom 12 in the manner described above and in such a manner that one side opens to the laundry facility and the other side opens to master bedroom 12 .
For the placement of hallway 24 in relationship to laundry facility 14 , the fifth structural element presents as the placement of hallway 24 adjacent to laundry facility 14 in order to increase laundry movement efficiency. Dual access closets 30 and 32 are located along hallway 24 near laundry facility 14 , as are dual access linen cabinets 36 and 38 .
For the placement of hallway 24 , dual access closets 30 and 32 , cabinets 36 and 38 , and non-adjacent rooms 16 , 18 , 26 , and 34 in relationship to one another, the fifth structural element presents as follows: Hallway 24 is located on the side of dual access closets 30 and 32 opposite respective bedrooms 16 and 18 . Bedrooms 16 and 18 are placed on the respective side of dual access closets 30 and 32 opposite hallway 24 . As a result, dual access closets 30 and 32 are located between specifically configured hallway 24 and respective bedrooms 16 and 18 in the manner described above and in such a manner that one side opens to hallway 24 and the other side opens to the respective bedrooms. In like manner, dual access linen cabinets 36 and 38 open to hallway 24 on one side and respective baths 26 and 34 on the other.
The combination of the five structural elements permits dirty laundry to be collected from dual access closet 28 and made available to laundry equipment 40 and 42 with minimal or no steps and, of chief benefit, permits clean laundry to be removed from the laundry equipment and hung or stored in dual access closet 28 with minimal or no steps. The clean laundry is conveniently accessible to the occupant(s) of master bedroom 12 without any further movement of laundry. The quality of the laundry output benefits from the minimal amount of time that elapses between the time the laundry is removed form equipment 40 and 42 and hung or stored in dual access closet 28 thereby decreasing wrinkles in the laundry output. The quality of the laundry output also benefits from the fact that the laundry will not be transported to another location, decreasing the possibility of soiling and/or wrinkling.
For the non-adjacent dual access closets 30 and 32 and dual access linen cabinets 36 and 38 , the combination of the five structural elements allows both dirty laundry to be collected from the closets, as well as from the cabinets, and clean laundry to be hung and stored into the same with minimal steps. The clean laundry is conveniently accessible to the occupant(s) of bedrooms 16 and 18 and bathrooms 26 and 34 .
A significant advantage of the present invention is that the occupants of bedrooms 12 , 16 , and 18 and of bathrooms 26 and 34 are not disturbed during the laundry process of collecting dirty laundry and returning clean laundry.
Still referring to FIG. 1 , in another embodiment, laundry facility 14 is located adjacent to kitchen 20 . In yet another embodiment as illustrated in FIG. 2 , the kitchen is located adjacent to stairway 48 , the top of which is located adjacent to laundry facility 14 on the second floor.
FIG. 3 illustrates a building structure 10 . For laundry processing, FIG. 3 is constructed similar to the building structure illustrated in FIG. 1 with the following exceptions. Dressing room 50 is adjacent to dual access closet 28 , whereas in FIG. 1 , master bedroom 12 is adjacent to dual access closet 28 . FIG. 3 also adds passage 52 to allow direct access from laundry facility 14 into dressing room 50 . In the presently described embodiment, all closets and laundry storage have been removed from master bedroom 12 . Closets within laundry facility 14 and/or dressing room 50 may be enclosed using doors and walls, or may be left open. Closets 29 a , 29 b , 29 c , and 29 d may be used for hanging laundry or other storage. In yet another embodiment, building structure 10 can include a slanted wall 54 and nook 56 , as opposed to being a strictly square design; while these features do not enhance laundry functions, they do illustrate that the invention can present with architectural interest.
FIG. 4 illustrates building structure 10 constructed similar to the building structure illustrated in FIG. 1 and described above. In another embodiment, dual access closets 28 , 30 , and 32 ( FIG. 1 ) are replaced by walk-in dual access closets 58 , 60 , and 62 ( FIG. 4 ), respectively.
The first structural element presents as walk-in dual access closets 58 , 60 , and 62 . Dual access linen cabinets 36 and 38 are also provided. The second structural element configures laundry facility 14 in a manner that allows full and efficient access to the dual access closet 58 from the laundry facility. An opening 64 provides a connection between laundry facility 14 and closet 58 , wherein full and efficient access is provided to the closet by placing the opening 64 in line with an aisle 66 of dual access closet 58 and in line with laundry equipment 40 .
To accommodate non-adjacent rooms 16 and 18 , the second structural element configures hallway 24 to allow full and efficient access to walk-in dual access closets 60 and 62 from the hallway. Full and efficient access from hallway 24 is provided for walk-in dual access closets 60 and 62 by placing openings 68 and 70 in line with respective aisles 72 and 74 . In FIG. 4 the doors for openings 68 and 70 are illustrated with bi-fold doors. It should be understood that other types of doors may be used.
The third structural element presents as a relatively narrow configuration of specifically configured laundry facility 14 thereby increasing laundry movement efficiency. While a width of only three feet between laundry equipment 40 and 42 and a solid wall adjacent to master bedroom 12 is sufficient for normal laundry processes and provides the greatest degree of laundry movement efficiency, a width of more than three feet may be preferred and is acceptable in the present invention. Likewise, specifically configured hallway 24 presents as relatively narrow configuration (approximately three to four feet) thereby increasing laundry movement efficiency for non-adjacent bedrooms 16 and 18 . It should be understood by one of ordinary skill in the art that laundry facility 14 and hallway 24 , as well as the other structures included in building structure 10 , may be constructed having other dimensions smaller or larger without departing from the scope and spirit of the present invention.
The fourth structural element configures master bedroom 12 and bedrooms 16 and 18 to allow full and efficient access to respective walk-in dual access closets 58 , 60 , and 62 . Thus, the wall in master bedroom 12 common to walk-in dual access closet 58 provides opening 76 in line with aisle 66 in order to allow full and efficient access to the closet by occupant(s) of the master bedroom. The walls in bedrooms 16 and 18 common to respective walk-in dual access closets 60 and 62 provide respective openings 78 and 80 in line with respective aisles 72 and 74 in order to allow full and efficient access to the closets by occupant(s) of the respective bedrooms.
The fifth structural element is placement of specifically configured laundry facility 14 in relationship to walk-in dual access closet 58 , and the placement of specifically configured master bedroom 12 in relationship to the closet. Laundry facility 14 is located on the side of walk-in dual access closet 58 that is opposite master bedroom 12 . Master bedroom 12 is located on the side of walk-in dual access closet 58 that is opposite laundry facility 14 . As a result, walk-in dual access closet 58 is placed between specifically configured laundry facility 14 and specifically configured master bedroom 12 in the manner described above and in such a manner that one side opens to the laundry facility and the other side opens to the master bedroom.
For the placement of hallway 24 in relationship to laundry facility 14 , the fifth structural element presents as the placement of hallway 24 adjacent to laundry facility 14 in order to increase laundry movement efficiency. Walk-in dual access closets 60 and 62 are located along adjacent hallway 24 near laundry facility 14 , as are dual access linen cabinets 36 and 38 .
For the placement of hallway 24 , dual access closets 60 and 62 , cabinets 36 and 38 , and non-adjacent rooms 16 , 18 , 26 and 34 , the fifth structural element presents as follows: Hallway 24 is located on the side of walk-in dual access closets 60 and 62 opposite respective bedrooms 16 and 18 . Bedrooms 16 and 18 are located on the sides of respective walk-in dual access closets 60 and 62 that are opposite hallway 24 . As a result, walk-in dual access closets 60 and 62 are located between hallway 24 and respective bedrooms 16 and 18 in the manner described above and in such a manner that openings 68 and 70 open to the hallway and openings 78 and 80 open to bedrooms 16 and 18 , respectively. In like manner, dual access linen cabinets 36 and 38 open to hallway 24 on one side and respective bathrooms 26 and 34 on the other. In another embodiment, laundry facility 14 is located adjacent to kitchen 20 .
In another embodiment as illustrated in FIG. 5 , a building structure 10 is constructed similar to the building structure of FIG. 4 . Two walk-in dual access closets 58 a and 58 b are added by expanding walk-in dual access closet 58 ( FIG. 4 ). Aisles 66 a and 66 b are defined by walk-in dual access closets 58 a and 58 b , respectively, and an aisle 66 c is defined between the closets. Opening 76 provides access to walk-in dual access closets 58 from master bedroom 12 and is inline with aisle 66 c . In another embodiment, an opening on the wall opposite opening 64 as denoted by shadow lines 82 provides access to walk-in dual access closets 58 . It should be understood that opening 82 may be in addition to opening 76 or may replace opening 76 thereby eliminating the need for aisle 66 c.
Openings 64 and 82 provide full and efficient access to walk-in dual access closets 58 by placing the openings inline with aisles 66 a and 66 b . Opening 76 provides full and efficient access to walk-in dual access closets 58 by placing the opening inline with aisle 66 c . Walk-in dual access closets 58 are located between laundry facility 14 and master bedroom 12 such that the closets are accessible from the laundry facility on one side and the master bedroom on the other allowing improved laundry efficiency as described above. It should be understood by one of ordinary skill in the art that other structural elements of building structure 10 illustrated in FIG. 5 are similar in construction and use as those described above with respect to the building structure shown in FIG. 4 .
FIG. 6 illustrates a building structure 10 . For FIG. 6 , description of the five structural elements is similar to FIG. 1 above with the exceptions described as follows. The first structural element presents as dual access closets 28 , 30 and 32 as in FIG. 1 . However, FIG. 6 offers the advantage of two dual access closets 28 and 30 , servicing two bedrooms 12 and 16 , adjacent to laundry facility 14 as opposed to only one dual access closet 28 servicing one bedroom 12 adjacent to laundry facility 14 in FIG. 1 . As in FIG. 1 , dual access closet 32 is directly across hallway 24 from laundry facility 14 .
The second structural element configures laundry facility 14 not only to allow full and efficient access to dual access closet 28 as does FIG. 1 , but to also allow same for dual access closet 30 . Thus, the dimensions of laundry facility 14 are configured to accommodate both closet 28 and 30 . Also, laundry facility 14 is configured such that laundry equipment 40 is placed at a distance from the door to closet 30 to allow full and efficient access to dual access closet 30 .
In FIG. 6 , the third structural element is similar to FIG. 1 in that laundry facility 14 has a relatively narrow configuration.
For FIG. 6 , the description of the fourth structural element regarding the configuration of the bedrooms is similar to that of FIG. 1 .
For FIG. 6 , the fifth structural element differs from FIG. 1 only in the placement of bedroom 16 and corresponding dual access closet 30 , in that bedroom 16 is located on the side of dual access closet 30 opposite laundry facility 14 , instead of opposite hallway 24 as in FIG. 1 . In FIG. 6 , the total distance between laundry equipment 40 and 42 and dual access closet 30 is reduced over the distance between same in FIG. 1 .
In another embodiment as illustrated in FIG. 7 , building structure 10 is a two-story structure. It should be understood by one of ordinary skill in the art that the structural elements of building structure 10 of FIG. 7 are similar in construction and use as those described with respect to building structure 10 of FIG. 6 , such that two dual access closets 28 and 30 are adjacent to laundry facility 14 and one dual access closet 32 is directly across hallway 24 a from laundry facility 14 .
Referring to FIG. 6 , in another embodiment kitchen 20 is placed adjacent to laundry facility 14 to allow full and efficient access to the kitchen from the laundry facility. Thus the kitchen 20 and the three bedrooms 12 , 16 and 18 form a rectangle around the laundry facility providing the shortest distance between the laundry facility and the rooms where the laundry will be used ( 20 , 12 , 16 , and 18 ) of all the embodiments presented herein. In FIG. 7 , kitchen 20 is located adjacent stairway 48 to allow laundry to be efficiently moved from laundry facility 14 to the kitchen via the stairway.
In another embodiment and referring to FIG. 8 , building structure 10 is a two-story building structure, which includes four dual access closets 28 , 30 , 32 a and 32 b that present as the first structural element. All four dual access closets are adjacent to laundry facility 14 and are of the reach-in type.
The second structural element configures laundry facility 14 in a manner that allows full and efficient access to dual access closets 28 , 30 , and 32 from the laundry facility. Thus, the height dimension of the walls in laundry facility 14 common to respective dual access closets 28 , 30 , and 32 is configured to equal or exceed the height dimension of the closets' respective openings. Also the length dimension of the wall in laundry facility 14 common to dual access closet 28 equals or exceeds the length of closet 28 and the length dimension of the wall in the laundry facility common to dual access closets 30 and 32 equals or exceeds the combined length of closets 30 and 32 .
The third structural element presents as a narrow configuration of specifically configured laundry facility 14 . Because dual access closet 28 is parallel to dual access closets 30 and 32 , and vise versa, access from all dual access closets to laundry equipment 40 and optional laundry equipment 42 is best accomplished by placing the laundry equipment in the middle of the laundry facility with the fronts of the washer and dryer facing each other and at distance from each other that allows passage when the doors to the laundry equipment are open. This configuration allows both dirty laundry to be collected from dual access closets 28 , 30 , and 32 and clean laundry to be hung or stored into same with minimal or no steps.
The fourth structural element configures master bedroom 12 and bedroom 16 in a manner that allows full and efficient access to respective dual access closets 28 and 30 . Thus the length and height dimensions of the respective walls in bedrooms 12 and 16 common to respective dual access closets 28 and 30 equal or exceed the length and height dimensions of respective openings to the closets in order to allow full and efficient access to the closets by occupants of the bedrooms. Since dual access closet 32 opens to hallway 24 a instead of bedroom 18 , the fourth structural element configures hallway 24 a in a manner that allows full and efficient access to the closet. Thus the height dimension of the wall in hallway 24 a common to dual access closet 32 equals or exceeds height dimensions of the openings to the closets in order to allow full and efficient access to the closets by occupants of bedroom 18 ; the length dimension of the hallway's wall equals or exceeds the combined length of bedroom 18 .
The fifth structural element presents as the placement of specifically configured laundry facility 14 in relationship to dual access closet 28 , and the placement of specifically configured master bedroom 12 in relationship to the closet. Laundry facility 14 is placed on the side of dual access closet 28 that is opposite master bedroom 12 . Specifically configured master bedroom 12 is placed on the side of dual access closet 28 opposite laundry facility 14 . As a result, dual access closet 28 is placed between specifically configured laundry facility 14 and specifically configured master bedroom 12 in the manner described above and in such a manner that one side opens to the laundry facility and the other side opens to the master bedroom. The fifth structural element also presents as the placement of the laundry facility 14 in relationship to the dual access closet 30 , and the placement of bedroom 16 in relationship to the dual access closet 30 . Laundry facility 14 is placed on the side of dual access closet 30 that is opposite bedroom 16 . Bedroom 16 is placed on the side of dual access closet 30 opposite laundry facility 14 . Thus, dual access closet 30 is placed between the specifically configured laundry facility 14 and bedroom 16 in the manner described in the two preceding sentences and in such a manner that one side opens to laundry facility 14 and the other side opens to bedroom 16 .
The fifth structural element also presents as the placement of laundry facility 14 in relationship to the dual access closet 32 , and the placement of hallway 24 a in relationship to the closet. Laundry facility 14 is placed on the side of dual access closet 32 that is opposite hallway 24 a . Hallway 24 a is placed on the side of dual access closet 32 opposite laundry facility 14 . As a result, dual access closet 32 is located between specifically configured laundry facility 14 and hallway 24 a in the manner described above and in such a manner that one side opens to laundry facility 14 and the other side opens to hallway 24 a . Bedroom 18 is located on hallway 24 a directly across from respective dual access closet 32 . In another embodiment, kitchen 20 is located adjacent to stairway 48 , the top of which is near laundry facility 14 .
In another embodiment and referring to FIG. 9 , building structure 10 is a two-story building structure, which includes dual access closets 28 and 30 adjacent to laundry facility 14 and dual access closets 32 across hallway 24 a from laundry facility 14 . It should be understood by one of ordinary skill in the art that the advantage of the presently described embodiment is that closets 32 are located within rooms 18 and that the disadvantage is that closets 32 are located across hallway 24 a from laundry facility 14 . It should also be understood that the other structural elements of building structure 10 are similar in construction and operation to those described above with respect to FIG. 8 .
In another embodiment and referring to FIG. 10 , building structure 10 includes laundry facility 14 coaxial with hallway 24 b , which is common to laundry facility 14 and bedrooms 16 and 18 . It should be understood by one of ordinary skill in the art that building structure 10 is beneficial for use of a laundry cart in that there would be no turns to make due to the fact that laundry facility 14 is in a straight line with hallway 24 b common to laundry facility 14 and non-adjacent bedrooms 16 and 18 .
The first structural element presents as walk-in dual access closet 58 and reach-in dual access closets 30 and 32 . Additionally, dual access linen cabinets 36 and 38 are provided. The second structural element configures laundry facility 14 in a manner that allows full and efficient access to dual access closet 58 from laundry facility 14 ; thus opening 64 is provided in laundry facility 14 to allow full and efficient access to closet 58 by placing opening 64 in line with aisle 66 of closet 58 and in line with laundry equipment 40 . Dual access linen closet 36 is provided adjacent to laundry facility 14 and master bathroom 12 to allow linens, such as towels and sheets, to be passed directly from laundry facility 14 to master bathroom 26 .
To accommodate non-adjacent bedrooms 16 and 18 and closets 30 and 32 , the second structural element configures hallway 24 b to allow full and efficient access to dual access closets 30 and 32 from hallway 24 b . Thus, the height of the wall in hallway 24 b common to dual access closets 30 and 32 equals or exceeds the height of the respective closets' openings; the length of the specifically configured hallway equals or exceeds the combined length of bedroom 16 , bathroom 34 , and bedroom 18 .
The third structural element presents as a relatively narrow configuration of specifically configured laundry facility 14 . This narrow configuration allows dirty laundry to be collected from dual access closet 58 and made available to laundry equipment 40 with minimal or no steps. This relatively narrow configuration also allows clean laundry to be hung or stored into dual access closet 58 from laundry facility 14 with minimal or no steps. While a width of only three feet between laundry equipment 40 and a solid wall is sufficient for normal laundry processes and offers the greatest degree of laundry movement efficiency, a width of more than three feet may be preferred and is acceptable in the present invention.
The fourth structural element configures master bedroom 12 , and bedrooms 16 and 18 in a manner that allows full and efficient access to respective dual access closets 58 , 30 , and 32 . Thus, the wall in master bedroom 12 common to walk-in dual access closet 58 provides opening 76 in line with aisle 66 in order to allow full and efficient access to closet 58 by occupant(s) of master bedroom 12 . The length and height dimensions of the respective walls in bedrooms 16 and 18 common to respective dual access closets 30 and 32 equal or exceed the length and height dimensions of the respective closets' openings in order to allow full and efficient access to the closets by the occupants of the respective bedrooms.
The fifth structural element presents as the placement of specifically configured laundry facility 14 in relationship to dual access closet 58 , and the placement of specifically configured master bedroom 12 in relationship to dual access closet 58 . Laundry facility 14 is placed on the side of dual access closet 58 that is opposite master bedroom 12 . Master bedroom 12 is placed on the side of dual access closet 58 opposite laundry facility 14 . As a result, dual access closet 58 is placed between specifically configured laundry facility 14 and specifically configured master bedroom 12 in the manner described above and in such a manner that one side opens to laundry facility 14 and the other side opens to master bedroom 12 . In like manner, dual access linen cabinet 36 opens to laundry facility 14 on one side and master bathroom 26 on the other.
For the placement of hallway 24 in relationship to laundry facility 14 , the fifth structural element presents as the placement of hallway 24 b adjacent to laundry facility 14 in order to increase laundry movement efficiency. Dual access closets 30 and 32 are placed on hallway 24 b near laundry facility 14 as are dual access linen cabinets 38 . Hallway 24 b is also placed in-line with laundry facility 14 rendering the structure ideal for the use of a laundry cart in that there would be no turns to make with the cart in order to access all dual access closets; therefore, laundry cart storage 07 is provided.
For the placement of hallway 24 b , dual access closets 30 and 32 , linen cabinets 38 , and non-adjacent rooms 16 , 18 and 34 in relationship to each other, the fifth structural element presents as follows: Hallway 24 b is placed on the side of dual access closets 30 and 32 opposite respective bedrooms 16 and 18 . Bedrooms 16 and 18 are placed on the respective side of dual access closets 30 and 32 opposite hallway 24 b . As a result, dual access closets 30 and 32 are placed between the specifically configured hallway 24 b and respective bedrooms 16 and 18 in the manner described above and in such a manner that one side opens to hallway 24 b and the other side opens to respective bedrooms 16 and 18 . In like manner, dual access linen cabinets 38 open to hallway 24 b on one side and respective bathrooms 34 on the other.
In another embodiment and referring to FIG. 11 , a building structure 10 for a smaller house is shown including a single dual access closet 28 . Structure and function of laundry facility 14 , dual access closet 28 and master bedroom 12 are similar to those described in FIG. 1 . In another embodiment, kitchen 20 is located adjacent to laundry facility 12 .
In another embodiment and referring to FIG. 12 , a building structure 10 is disclosed where the laundry facility 14 and hallway 24 of other embodiments described above (e.g., FIG. 1 ) are combined into a single laundry facility hallway (indicated at 15 and referred to as “combined facility”). An advantage of the presently described embodiment is a reduction of square footage over structures with a separate laundry facility. Possible disadvantages of the presently described embodiment is a lack of room for storage of laundry supplies, lack of room for optional laundry equipment 42 ( FIG. 1 ), congestion and clutter in combined facility 15 during the laundry process, the disturbance of occupants in adjacent rooms 16 and 34 by the sound produced by laundry equipment 40 , as well as the significant distance between laundry equipment 40 and kitchen 20 . This structure would require no turns for the use of a laundry cart to reach all dual access closets, and therefore, laundry cart storage 07 is provided.
The first structural element presents as dual access closets 28 , 30 , 32 and 33 . The second structural element configures combined facility 15 in a manner that allows full and efficient access to dual access closets 28 , 30 , 32 , and 33 from the combined facility. Thus, the height of the walls in combined facility 15 common to dual access closets 28 , 30 , 32 , and 33 equals or exceeds the height of the respective closets' openings; the length of the specifically configured combined facility equals or exceeds the combined length of laundry cart closet 07 , master bedroom 12 , and bedroom 19 .
The third structural element presents as a relatively narrow configuration of the combined facility 15 . This narrow configuration allows dirty laundry to be collected from dual access closets 28 , 30 , 32 , and 33 and made available to laundry equipment 40 with minimal or no steps. This relatively narrow configuration also allows clean laundry to be hung or stored into dual access closets 28 , 30 , 32 , and 33 from combined facility 15 with minimal or no steps. While a width of only three feet between laundry equipment 40 and a solid wall is sufficient for normal laundry processes and offers the greatest degree of laundry movement efficiency, however, a width of more than three feet may be preferred and is acceptable in the present invention.
The fourth structural element configures master bedroom 12 and bedrooms 16 , 18 , and 19 in a manner that allows full and efficient access to respective dual access closets 28 , 30 , 32 , and 33 . Thus, the length and height dimensions of the respective walls in bedrooms 12 , 16 , 18 , and 19 common to respective dual access closets 28 , 30 , 32 , and 33 equal or exceed the length and height dimensions of respective closets' openings in order to allow full and efficient access to the closets by the occupants of the respective bedrooms.
The fifth structural element presents as the placement of the specifically configured combined facility 15 in relationship to dual access closets 28 and 33 , and the placement of respective master bedroom 12 and bedroom 19 in relationship to the respective closets. Combined facility 15 is placed on the side of dual access closets 28 and 33 that is opposite respective master bedroom 12 and bedroom 19 . Master bedroom 12 and bedroom 19 are placed on the respective side of dual access closets 28 and 33 opposite combined facility 15 . As a result, dual access closets 28 and 33 are placed between combined facility 15 and master bedroom 12 and bedroom 19 in the manner described above and in such a manner that one side opens to combined facility 15 and the other side opens to the respective bedroom.
The fifth structural element also presents as the placement of specifically configured combined facility 15 in relationship to the dual access closets 30 and 32 , and the placement of specifically configured bedrooms 16 and 18 in relationship to the respective closets. Combined facility 15 is placed on the side of dual access closets 30 and 32 opposite respective bedrooms 16 and 18 . Bedrooms 16 and 18 are placed on the respective side of dual access closets 30 and 32 opposite combined facility 15 . As a result, dual access closets 30 and 32 are placed between specifically configured combined facility 15 and respective bedrooms 16 and 18 in the manner described above and in such a manner that one side opens to combined facility 15 and the other side opens to the respective bedroom.
It should be understood that FIGS. 13 , 14 , 15 , and 16 are offered as possible additions to the present invention, in that the other aspects of the invention can function without FIGS. 13 , 14 , 15 , and 16 . It should be further understood that FIGS. 13 , 14 , 15 , and 16 operate independent of each other.
Referring to FIG. 13 , an overhead rod 84 , either permanent or retractable, running length-wise through laundry facility 14 permits immediate hanging of clothes that are to be transferred to any non-adjacent closets. The quality of the laundry output benefits from the minimal amount of time that elapses between when laundry is removed from equipment 40 and hung on rod 84 thereby decreasing wrinkles in the laundry output. A second overhead rod 86 running parallel to rod 84 and several inches from rod 84 allows large items to be draped over both rods for drying. The purpose of rod 86 is to allow airflow to assist in the drying process and to prevent the large items from touching the floor. The double rod feature is particularly helpful for large items that cannot be placed in the dryer (of equipment 40 ), such as electric blankets. It should be understood by one of ordinary skill in the art that the number of hanging rods, such as rods 84 and 86 , is variable based on the size and structure of laundry facility 14 .
Referring to FIG. 14 , a fan or multiple fans 88 may be placed in the closets described above (such as closet 28 of FIG. 1 ), preferably attached to the ceiling of the closets, or in laundry facility 14 ( FIG. 1 ) to permit air drying of clothes.
Referring to FIG. 15 , folding and transporting of laundry are further reduced by including shelving in the dual access closets described above, such as dual access closet 28 ( FIG. 1 ). It should be understood by one of ordinary skill in the art that shelves 90 can be used in both reach-in and walk-in dual access closets. Shelving 90 accommodates laundry baskets and/or other containers for the sorting and storage of clean clothing and linens, such as underwear, socks, towels, washcloths, sheets, etc. This feature eliminates the need for folding the aforesaid items and conveniently places items in an accessible place for the end-user. The need for transporting these items is eliminated for dual access closets adjacent to laundry facility 14 ( FIG. 1 ), such as closet 28 ( FIG. 1 ), and minimized for the non-adjacent dual access closets, such as closet 30 ( FIG. 1 ). Shelving 90 preferably has an adjustable height feature to accommodate the varying needs of end-users and may be placed in the closet(s) underneath or above hanging clothes or may run floor to ceiling, within or beside the closet(s), such as closet 28 ( FIG. 1 ).
Referring to FIG. 16 , in another embodiment of the present invention, a revolving hanger system 92 is disclosed and may be used in a dual access closet, such as closet 28 ( FIG. 1 ). As described above with respect to FIG. 1 , dual access closet 28 is located within a common wall adjacent to laundry facility 14 on one side and master bedroom 12 on the other. Door 94 opens to laundry facility 14 ( FIG. 1 ) on one side, while door 96 opens to another room located opposite the common wall from the laundry facility. Although closet 28 opens to laundry facility 14 ( FIG. 1 ) via door 94 , it should be understood that closet 28 may be employed between a room and a common hallway. Doors 94 and 96 are depicted as sliding doors to closet 28 , but it should be understood that the doors can be hinged, pocket doors, folding doors, etc., as long as the doors allow users to access the closet from opposite sides (denoted by arrows 98 and 100 ), respectively. Hangers holding clothes and other laundry can be placed on hanger system 92 , which moves along a path within closet 28 ( FIG. 1 ) as denoted by arrows 102 and 104 . As a result, items placed on hanger system 92 from the right side of closet 28 ( FIG. 1 ) as denoted by arrow 104 will move to counterclockwise along the path of the hanger system to the closet's left side as denoted by arrow 102 and vise versa. It should be understood by one of ordinary skill in the art that the manner of rotation of hanging system 92 can be altered depending on the size and structure of the rooms adjacent to the closet and the needs of the end-users. Therefore, clean laundry may be placed and organized on revolving hanger system 92 while standing in one spot from laundry facility 14 ( FIG. 1 ), and an occupant of a room on the opposite side, such as master bedroom 12 ( FIG. 1 ), may select from all the items on the revolving hanger system while standing in another spot. Dirty laundry may also be placed and organized on revolving hanger system 92 while standing in one spot and can also be collected while standing in another spot. As a result, the amount of time and labor required in the laundry process is optimized.
While one or more embodiments of the present invention have been described above, it should be understood that any and all equivalent realizations of the present invention are included within the scope and spirit thereof. Thus, the embodiments presented herein are by way of example only and are not intended as limitations of the present invention. Therefore, it is contemplated that any and all such embodiments are included in the present invention as may fall within the scope of the present invention. | Structural elements and features are provided to significantly reduce the time and effort required in the household laundry process of collecting dirty laundry, washing, drying, hanging, and storing laundry. These same structural elements improve the quality of the laundry output. A reduction in time and effort is accomplished by locating a laundry facility central to a plurality of rooms within the building structure and placing closets within the walls separating the laundry facility from the adjacent rooms. These closets are accessible from the laundry facility on one side and the respective room on the other. In another aspect of the invention, rooms that are not directly adjacent to the laundry facility may be located on a hallway common to the laundry facility and the non-adjacent rooms. The walls dividing the non-adjacent rooms from the common hallway may likewise include closets that are accessible from the common hallway on one side and the respective room on the other. In a variation of the present invention the laundry facility is combined with the hallway. Most of the rooms where the laundry will be used are adjacent to the laundry facility/hallway combinations. The walls dividing the rooms from the hallway may likewise include closets that are accessible from the hallway on one side and the respective room on the other. | 4 |
[0001] This application claims priority to German Patent Application DE10160996.5, filed Dec. 12, 2001, the entirety of which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] This invention relates to a device for air mass flow control.
[0003] The provision of air systems, in particular cooling-air systems for gas turbines, is known from the state of the art. These systems, in particular those provided for cooling purposes in the hot section of the engine, are dimensioned or designed such that they give adequate cooling also under the most adverse conditions, for example at maximum power and the associated highest temperature ranges.
[0004] Many of these air systems are not designed adaptively, which results in excessive air mass flow and overcooling under part-load operating conditions or operating conditions requiring lesser cooling. As a consequence, a larger air mass than actually required is supplied to the turbine.
[0005] Disadvantageously, with an excessive cooling-air mass being taken from the compressor, the efficiency of the gas turbine is compromised. This decreased efficiency leads to an increase of the specific fuel consumption of the gas turbine, with the consequence that costs increase and the aircraft range is reduced.
[0006] Designs are known in state of the art in which valve elements, flaps or similar devices provided in the respective air ducts can be opened or closed by means of a separately controlled or governed actuator. Reference is here made to the U.S. Pat. Nos. 4,462,204 and 4,807,433, as well as 6,202,403, for example.
[0007] These arrangements, however, incur high manufacturing effort and operational complicacy due to the necessity for appropriate governing or controlling means.
BRIEF SUMMARY OF THE INVENTION
[0008] In a broad aspect, the present invention provides a device for air mass flow control that, while being simply designed and easily and safely operable, is self-controlling and enables the cooling-air mass flows to be accommodated automatically.
[0009] It is a particular object of the present invention to provide means for the solution of the above problem by the present invention featuring the characteristics described herein, with further advantages and aspects of the present invention becoming apparent from the description below.
[0010] The present invention accordingly provides a device for air mass flow control with at least one inlet duct which issues into an air duct or the like. The present invention furthermore provides for a counter-pressure duct which is located downstream of the mouth of the inlet duct and branches off from the air duct.
[0011] The present invention also covers a double-acting shut-off element that is connected between the counter-pressure duct and the inlet duct and is movable to control the flow in the inlet duct.
[0012] The present invention is characterized by a variety of merits.
[0013] The adaptive, self-controlling design of the device ensures that it automatically adjusts to the respective operating points or operating conditions of the gas turbine. Thus, the supply of cooling-air is accommodated to the actual demand. Accordingly, removal of an excessive air mass from the compressor is avoided. As a consequence, overall efficiency of the gas turbine increases and fuel consumption decreases accordingly, for example at cruising speed.
[0014] The arrangement according to the present invention, therefore, makes use of the pressure differences which occur in the engine in dependence on the respective operating point to control or govern the shut-off element. The present invention accordingly provides for a very simple, mechanical means of control, fully dispensing with additional electronic monitoring or control/governing devices.
[0015] In a particularly advantageous form, the shut-off element includes a double-action piston-cylinder unit. Thus, a pressure-controlled metering valve is provided which can have high simplicity of design and construction and high reliability of operation. Shut-off elements of this type enable the individual components of a gas turbine to be separately supplied with cooling air.
[0016] The entire arrangement can be manufactured in a very easy and cost-effective way and requires low maintenance effort.
[0017] In a particularly favorable design, the piston itself provides the means for flow control. In such a design, additional shut-off elements or similar means are not required. In a favorable form, the piston itself can be brought into the flow area of the inlet duct, or air duct, as a shut-off element to control its cross-section and, thus, the air mass flow.
[0018] In an alternative form or development of the present invention, provision can also be made such that the means for flow control can include additional structure to control or govern several inlet ducts. It may in this case be favorable to provide a slider-type element, an annular element or a similar means to enable control of several cooling-air ducts at the same time.
[0019] Since the varying pressure differences encountered are used as input variable, the device according to the present invention provides both for continuous and staged control of the cooling-air mass flow.
[0020] The device according to the present invention is, therefore, a self-contained control/governing system which does not require external actuation or similar means.
[0021] In accordance with the present invention, the device can be used either locally for the control of the cooling-air mass flow of an individual component or for the control of cooling-air flows of a plurality of components, for example cooling-air flows in annuli or the like.
[0022] With regard to the underlying technical principle, the amount of the pressure difference is not crucial for the operation of the device.
[0023] Summarizing, then, the reduction of the cooling-air mass flows gives rise to an increased efficiency of the gas turbine. This provides for lower fuel costs and enables longer flight missions to be executed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Further aspects and advantages of the present invention are described by way of the embodiments shown on the accompanying drawings, in which:
[0025] [0025]FIG. 1 is a schematic partial sectional view of a partial area of a gas turbine according to the present invention,
[0026] [0026]FIG. 2 is a highly simplified representation of a first embodiment of the device according to the present invention showing a state of control involving high pressure differences,
[0027] [0027]FIG. 3 is a presentation, analogically to FIG. 2, involving low pressure differences,
[0028] [0028]FIG. 4 is a simplified representation of a further embodiment in the initial state, and
[0029] [0029]FIG. 5 is a presentation, analogically to FIG. 4, in a state with reduced air mass flows.
DETAILED DESCRIPTION OF THE INVENTION
[0030] [0030]FIG. 1 shows, in highly simplified representation, a side view of a partial area of an aircraft gas turbine. A combustion chamber is here indicated by the reference numeral 7 . A downstream turbine features a turbine casing 8 within which stator vanes 9 of a first stage and rotor blades 10 of the first stage are shown. The rotor blades 10 are attached to a rotor disk 11 of the first stage in conventional manner. Further in the downstream direction, a stator vane 12 of a second stage is shown which is associated with a rotor blade 13 of the second stage, this rotor blade 13 again being attached to a rotor disk 14 of the second stage. Reference numeral 15 indicates a turbine exit guide vane.
[0031] [0031]FIG. 1 further shows, in highly simplified form, a piston-cylinder unit 4 which is a part of an embodiment of the device for air mass flow control according to the present invention. The piston-cylinder unit 4 is located in the area of an inlet duct 1 , exposed to a cooling air flow, with flow in the inlet duct issuing into an air duct 2 branching off from the inlet duct 1 . The inlet duct 1 and air duct 2 may, for example, be used for ducting air from the cooling air flow to cool the stator vanes 9 or 12 , respectively.
[0032] In the downstream direction, a counter-pressure duct 3 is provided by which pressure, for instance, from the turbine section of the engine, is applied to the rearward area of the piston 5 of the piston-cylinder unit 4 .
[0033] Furthermore, the piston-cylinder unit 4 comprises a spring 16 by which a suitable pre-load is applied to the piston 5 to bias the piston in the desired direction.
[0034] Operation of the invention becomes apparent from FIGS. 2 and 3. FIG. 2 shows a state with a high pressure difference. In this state, the pressure force in the inlet duct 1 exceeds the sum of the pressure force in the counter-pressure duct and of the pre-load force of the spring 16 . The piston 5 is accordingly displaced (to the right in FIG. 2) such that the flow area of the air duct 2 is cleared or not obstructed. FIG. 3 then shows an operating condition with a low pressure difference. As a result of the low pressure difference, the pressure force in the counter-pressure duct 3 , together with the pre-load force applied by the spring 16 , exceeds the pressure force in the inlet duct 1 , with the effect that the piston 5 is displaced (to the left in FIG. 3) to partly cover the free cross-section of the air duct 2 , thus reducing the supply of air. In the preferred embodiment, flow in the air duct 2 is never completely shut off by the piston 5 so that there is always a minimum air flow through the ducts during operation. Alternatively, the piston can be used to completely shut off flow in the duct. In the embodiment shown, in a relaxed state, the piston is displaced to the left to close off the air duct 2 , although this can be reversed if the application so warrants. Further, the shut-off mechanism can be configured to operate in a continuous manner where the piston progressively varies the opening in the duct in response to changes in the pressure differential, or in a digital or staged manner in which the piston is either in a fully open or a fully closed position.
[0035] [0035]FIGS. 4 and 5 show a further embodiment of the present invention, in which a piston-cylinder unit 4 is similarly applied. Same parts are identified with the same reference numerals. The representation of FIGS. 4 and 5 corresponds, for example, to a front view of the arrangement of FIG. 1. As becomes apparent, a common slider-type element 6 is provided which is coupled to the piston 5 . Displacement of the piston involves rotation of the slider-type element enabling it to control or govern the flow area of several air ducts 2 , at the same time. In this case, flow in the inlet duct 1 may not issue into the air ducts 2 .
[0036] It is apparent that a plurality of modifications other than those described herein may be made to the embodiments here shown without departing from the inventive concept and different aspects of the present invention can be combined in different ways to create different embodiments. | A device for air mass flow control in a gas turbine engine includes at least one inlet duct 1, which can issue into an air duct 2, a counter-pressure duct 3, and a double-action shut-off element, which is connected between the counter-pressure duct 3 and the inlet duct 1 and is responsive to pressure differences between the two ducts to control air flow in the air duct 2. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to ink reservoirs for thermal ink jet ("TIJ") print cartridges.
TIJ technology is widely used in computer printers. Very generally, a TIJ includes a print head typically comprises several tiny controllable ink jets, which are selectively activated to release a jet or spray of ink from an ink reservoir onto the print media (such as paper) in order to create an image or portion of an image. TIJ printers are described, for example, in the Hewlett-Packard Journal, Volume 36, Number 5, May, 1985, and Volume 39, Number 4, August, 1988.
In TIJ pens it is necessary to connect the ink reservoir to the print head. The size of this connection affects the design of the printer that the pens are used in. An ideal reservoir-to-print-head coupler, from a printer design point of view, would be no longer than the TIJ head is long, and would be high or tall enough to allow the drive and pinch wheels to get as close to the print head as possible. Any increase in the size of this coupler will compromise the paper handling ability, which may affect the print quality, and increase the size of the printer. Smaller printers are desirable as they conserve desk space and the materials from which the printer is fabricated.
An intended application for this invention is for a spring bag TIJ pen, although it is not limited to the spring bag pen. In one exemplary spring bag pen design, the pen frame made of a first molded material is lined with a second molded material, such as polyethylene, on the inside to produce a surface suitable for staking the films of the spring bag. The first molded material from which the frame is made could be, for example, an engineering plastic, and provides the necessary structure for the pen which could not be accomplished with the second molded material. This invention relates to the fluid connection of the first and second molded materials in such a way as to provide a space-efficient, leak-resistant connection.
Conventional methods of connecting materials include the use of glue, seals, such as gaskets or 0-rings, or mechanical press fits. In these cases two or more separate parts are fabricated and assembled together to form a single unit. Each part must be designed and sized with respect to its needs in manufacturing, structural integrity, and with the tolerance of the mating part in mind. Such joints as these take up much more space than joints fabricated in accordance with this invention. In addition to taking up much space, the traditional methods produce a joint whose reliability can be affected by the part tolerances, surface finishes, and the assembly operation. The method of this invention provides a joint which is less susceptible to surface finish defects than joints obtained by such traditional methods.
SUMMARY OF THE INVENTION
A thermal inkjet print cartridge ink reservoir in accordance with the invention is characterized by a compact, leak-resistant joint between first and second moldable materials which define the frame of the reservoir. The reservoir includes a first frame element having a snout end and defining an interior standpipe member through which a channel opening extends. The channel opening extends between the ink reservoir chamber and a thermal inkjet print head. The first frame element is fabricated from a first moldable plastic.
The ink reservoir includes a second frame element fabricated from a second moldable plastic material characterized by a shrink rate as the material cools from a molten state. The second frame element is formed by injection molding and surrounds the periphery of the standpipe member to thereby provide the compact, leak-resistent joint, in that the second moldable material has shrunk about the periphery of the standpipe member to define the joint.
A method in accordance with this invention is for forming a leak-resistant joint between first and second moldable materials, and includes the following steps:
molding the first material into a predetermined first shot structure defining an interior fluid standpipe through which a channel opening extends;
positioning the first shot structure in a second shot mold;
injecting the second moldable material in a molten state into the mold as a second shot wherein the second material surrounds the standpipe member, the second material characterized by a shrink rate as the material cools; and
permitting the second material to cool, whereupon the second material shrinks about the periphery of the standpipe, thereby forming a leak-resistant seal between the first and second materials about the standpipe.
Use of this method to join the two materials allows the surface of the first shot to be used, as molded, and the molding negates the effects of the tolerance and surface finish of the second molded material on the joint. When the second molded material is molded onto the first molded material it shrinks as it cools and produces a tight joint.
This method of connection is more reliable than conventional methods. Since the second molded material, e.g., polyethylene, is molded onto the first molded material, which can be used as a structural element, the first molded material imparts stiffness to the second molded material. The second molded material therefore can be designed to be thinner in cross section than if the part were made by conventional methods. Because the second molded material is never handled as a separate part on an assembly line, as would be the case in a traditional two-part design, its cross sections are not burdened by the stiffness that handling would require, and therefore the design is more compact from this perspective also.
BRIEF DESCRIPTION OF THE DRAWING
These and other features and advantages of the present invention will become more apparent from the following detailed description of an exemplary embodiment thereof, as illustrated in the accompanying drawings, in which:
FIG. 1 illustrates a thermal inkjet print cartridge ink reservoir embodying the present invention.
FIG. 2 is a close-up view of the snout region of the rigid engineering plastic member comprising the ink reservoir of FIG. 1.
FIG. 3 is a close-up view of the snout region of the ink reservoir of FIG. 1, showing both the rigid plastic member and the polyethylene member comprising the ink reservoir.
FIG. 4 is a cross-sectional view taken along line 4--4 of FIG. 2.
FIG. 5 is a cross-sectional view taken along line 5--5 of FIG. 3.
FIG. 6 illustrates the second "shot" process in which the polyethylene member comprising the frame of the ink reservoir is molded.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1-6 illustrates a compact thermal inkjet print cartridge ink reservoir 20 in accordance with this invention. In this exemplary embodiment, the backbone or frame 22 of the reservoir 20 comprises two chemically dissimilar plastics, an engineering plastic, e.g., a glass-filled modified polyphenylene oxide (such as the material sold under the trademark "NORYL"), and 10 percent glass-filled polyethylene, which are molded one onto the other to form a leak-resistant joint in accordance with this invention. The frame 22 is stiffened by a pair of sheet metal covers 24 (only one of which is visible in FIG. 1) which attach to its sides. This structure of frame 22 and covers 24 is intended for use with a spring bag ink delivery system of the type described in pending U.S. patent application Ser. No. 07/717,735, filed Jun. 19, 1991, now U.S. Pat. No. 5,359,353 entitled "Spring-Bag Printer Ink Cartridge with Volume Indicator," by David S. Hunt and W. Bruce Reid and assigned to a common assignee with the present invention. A print head (not shown) is connected at the snout end 26 of the reservoir for selectively releasing a jet of ink from the reservoir.
In accordance with the invention, the seal between the two dissimilar materials comprising the frame 22 employs a shrink fit at the container snout end to clamp the two plastics tightly together. FIG. 2 illustrates the snout end 26 of the reservoir 20 in its form prior to molding the polyethylene 22B onto the engineering plastic frame member 22A. The member 22A is an integrally formed frame member molded of the engineering plastic. At the snout end 26, the member 22A defines an interior, upright fluid standpipe 28 having an interior opening 30 defined therein which extends through the standpipe to an opening formed in the exterior surface of the frame member 22A. It is through this opening that the ink will flow from the reservoir. The ink jet head (not shown) will be positioned along the surface 36.
The end 26 of the member 22A is shown in further detail in the cross-sectional view of FIG. 4. FIG. 2 illustrates the open region 32 surrounding the upwardly extending fluid standpipe 28 within the frame 22A. A pair of spaced ribs 34 and 35 protrude from the exterior side of the standpipe 28.
Now referring to FIGS. 3 and 5, the reservoir frame 22 is shown with the polyethylene layer 22B molded to the inside surface of the frame 22A. The layer 22B in the region 26 is best illustrated in the cross-sectional view of FIG. 5. The polyethylene material 22B has been molded around the periphery of the standpipe 28, without covering the opening 30. The polyethylene material 22B provides a surface to which the spring bag film may be staked. It is therefore important that there be no leaks between the standpipe 28 and the surrounding molded layer of polyethylene, as this would defeat the integrity of the reservoir, and permit ink to leak from the reservoir, or air to get into the reservoir.
The method of molding the layer 22B to the frame element 22A is now described. First, the frame element 22A of modified polyphenylene oxide, i.e., a first molded material, is fabricated in a plastic injection mold. This part 22A, referred to as the "first shot," is illustrated in FIGS. 2 and 4. The first shot 22A is next inserted into a second mold, where the polyethylene 22B, i.e., the second molded material, is molded onto it. The polyethylene is injected into the mold under appropriate pressure and at an appropriate temperature. For polyethylene, an exemplary pressure is in the range of 4,000 to 10,000 psi, and an exemplary melt temperature is 400° F. This polyethylene "second shot" has a degree of mold shrinkage (such as, for high density polyethylene without glass, about 0.022 inches/inch); upon cooling, the polyethylene material shrinks tightly onto the ribs of the first shot. Thus, the necessary property of the second molded material is that it shrinks during the cooling process.
FIG. 6 illustrates the second shot molding process. A cavity mold pin 50 is extended above the top of the channel 30. The cavity mold pin 50 is attached to and moves with the mold half 54. A channel cavity mold pin 52 is inserted into the channel opening 30 formed in the frame member 22A and against the cavity mold pin 50. The mold halves 54 and 56 are closed together, defining the interior opening into which the molten polyethylene is injected or "shot," together with surfaces of the first molded material. Thus, according to another aspect of the invention, the mold cavity for the second shot is partially defined by surfaces of the first shot, i.e., the first molded material. Surfaces of the frame member 22A serve as stop surfaces against which the respective mold halves bear when the mold is closed to stop the flow of the molten second material. Thus, in FIG. 6 surfaces 23A and 23B of the frame member 22A are contacted, or brought in close proximity, such as 0.001 inch or less, by corresponding surfaces of the mold halves 54 and 56, and prevent flow of the second material into the mold cavities generally indicated by 55 and 57.
After the second "shot" of polyethylene is cooled, forming the polyethylene member 22B, the mold halves 54 and 56 are separated. The mold pin 52 is withdrawn during mold separation.
The molded joint resulting from this invention retains water and thermal inkjet printing inks, and keeps air out under moderate pressure and vacuum, through a range of environmental conditions normally experienced by office products. The internal stresses inherent to the second shot, as it shrinks about the standpipe, keep it from pulling away from the first shot. The mold and first shot material, which are at a lower temperature than the second shot molding temperature, cool the second shot material. When the polymer passes through its glass transition temperature, it changes phases from liquid to solid. When in the solid state the plastic temperature continues to drop from its glass transition temperature T g to the mold temperature, e.g., where T g is on the order of 300° F. and the mold temperature is on the order of 100° F. The thermal contractions during this part of the cooling process results in the formation of internal stresses in the now solid second shot.
The process of this invention is applicable to multicavity molding and also two-shot molding, where both plastics are injected during different cycles of the same molding machine. As is well known in the art, multi-cavity molds are used to produce as many parts per cycle as there are cavities in the mold.
Pressure decay leak-testing of parts fabricated using this seal show minimal leak rates. Further, the seal has proven to endure throughout the print cartridge assembly process, during which the ink reservoir is subjected to mechanical and thermal stresses. The seal has been tested successfully with various ribs and different plastic materials, such as polysulfone for the first shot, i.e., the first molded material, and glass-filled polyethylene as the second shot, i.e., the second molded material. Other materials may be suitable for the first and second molded materials.
The joint created by the method of the present invention is resistent to air leaks into the reservoir and ink leaks out of the reservoir, i.e., it is resistent to the leakage of air into the closed ink reservoir via the joint at the materials interface at the standpipe, and to the leakage of ink out of the interface via the joint. The joint is of value even if not air-tight, as it would be necessary for air to bubble through the interface formed by the materials of the first and second shots wetted by ink via a bubble generator effect. Air would bubble through the interface only under a pressure differential well above conditions likely to be faced by an ink jet cartridge.
While the standpipe described above has two ribs, such ribs are not necessary for the joint to properly function as a leak-resistent joint. The ribs do add leak-resistent margin by making the capillary path that the ink must travel to leak out more tortuous, and therefor adds to the energy necessary for the ink to leak. However, some applications may not allow the use of such ribs, and the joint without ribs is still leak-resistent.
While the preferred embodiment has employed dissimilar plastic materials as the first and second molded materials, that is not necessary to obtain a leak-resistent joint with the invention. In fact, in particular applications, the same material can be used for both materials, so long as the material is characterized by the property that it shrinks upon cooling from the liquid state to the solid state.
The first shot material is typically characterized by a higher melting temperature than the second shot material. The first shot material could be compounded or non-compounded relative to the virgin base material. In this context a "compounded" material is one in which additives such as glass bead, glass fiber, talc, metal particles, or the like have been blended with the base material. For example, compounded materials suitable for use as the first shot material include 20% glass-filled modified polyphenylene oxide or glass-filled polysulfone. Polyethylene terephthalate (PET), either filled or non-filled, is also suitable for use as the first shot material.
The second shot material preferably has a melting point which is equal to or less than the melting temperature of the first shot material, although in some applications a second shot material with a higher melting temperature than the first shot could be used. The second shot material can be compounded or non-compounded material, such as glass-filled or non-glass-filled polypropylene, or the like, or even glass-filled or non-glass-filled polysulfone.
An advantage gained from this invention is the ability to attach the two plastic parts without an intermediate assembly step. Each plastic material is specified for its unique properties in different aspects of print cartridge reservoir assembly and operation; previously such a combination had to be fabricated separately and then joined. Using this seal, no assembly equipment is required, only one part need be handled, and there is no yield loss associated with imperfect joints. The two plastic components are attached to each other without resorting to devices such as snap fits, screw holes, etc., which would take up additional space; instead, all of the space in the ink reservoir is utilized for attachment of the covers and the spring bag films, ensuring adequate stiffness and making effective use of the available space for storing ink.
It is understood that the above-described embodiments are merely illustrative of the possible specific embodiments which may represent principles of the present invention. Other arrangements may readily be devised in accordance with these principles by those skilled in the art without departing from the scope and spirit of the invention. | A method for joining two materials together to form a compact leak-resistant seal, particularly suited for use in thermal inkjet print cartridge ink reservoirs. The seal employs a shrink fit to clamp the two materials together. The method includes the steps of forming the first material into a desired first shot structure, placing the first shot structure in a second shot mold, and injecting the second material into the mold under adequate pressure and at an appropriate temperature. The second material has a high degree of mold shrinkage. Upon cooling, the second material shrinks tightly onto the first shot structure to form a molded joint which keeps air out and ink in when wetted and during normal shipping, storage, and operating conditions. | 1 |
This application is a continuation of application Ser. No. 22,857 filed Mar. 6, 1987, now abandoned.
BACKGROUND OF THE INVENTION
This invention generally relates to the use of microorganisms to enhance oil recovery from petroleum reservoirs. Here, a specific strain of bacteria is used to plug high permeability zones and increase waterflood efficiency by redirecting the flood to lower permeabiltiy, oil-bearing zones.
Petroleum that is in underground reservoirs is brought to the surface in a variety of ways. One of the more notable publicly held ideas of oil recovery is the "gusher," however, due to the changing nature of oil reserves, and economic and environmental policies, the gusher is the thing of the past. Surface pumps, which are a common highway sight, oftentimes provide the lift force necessary to bring oil to the surface in those reservoirs where the reservoir pressure is insufficient. Additionally, subsurface pumps can be coupled with the surface pumps to assist in the lifting duty. However, there comes a time in the life of many reservoir formations in which the reservoir pressure and the pumping devices are not enough to overcome the oil viscosity and the capillary forces of the formation. At this point, enhanced oil recovery (EOR) techniques are useful to recover additional oil that refuses to come to the surface by the means described above.
The term "EOR" spans a panoply of techniques and devices that are used to recover the last bit of oil reserves. There are devices and methods for: steam injection, water injection, gas drive, emulsification, injecting plugging agents, etc. One "device" that may perform many of these feats is a microorganism, most notably, a bacteria.
The idea of using bacteria to increase or enhance oil recovery is not new. Many laboratory investigations and a number of field tests have been performed both in the U.S. and elsewhere [see generally, J. Davis, Petroleum Microbiology (1967) and works collected in J. E. Zajic et al., Microbes and Oil Recovery, Bioresource Publications, El Paso (1985)]. Several technical meetings devoted exclusively to microbial enhanced oil recovery (MEOR) have been held. Some of the previous literature consists of anecdotal accounts or inadequately controlled studies, resulting in a skeptical appraisal of the technology. [See also D. Hitzman, Petroleum Microbiology and the History of its Role in Enhanced Oil Recovery, Proc. Int'l. Conf. on Micro. Enh. Oil Rec., p 162, (May 16-21, 1982), and E. Donaldson et al., There are Bugs in My Oil Well, Chemtech, p 602 (October 1985).]
The principle behind MEOR is based on the fact that microbes can produce most of the agents now employed in chemical EOR; i.e., water-soluble polymers, surfactants, co-surfactants and solvents such as ethanol and acetone, and acids. (See M. Singer, Microbial Biosurfactants in Zajic, Microbes and Oil Recover, U.S. Pat. No. 4,522,261 to McInerney et al., U.S. Pat. No. 2,807,570 to Updegraff and U.S. Pat. No. 2,660,550 to Updegraff et al.) Some microbial-produced products, e.g., xanthan biopolymer, are now commercially used for EOR. Such use is dependent on the cost-effectiveness of the microbial product compared to competing non-microbial products, e.g., xanthan as compared to polyacrylamide. In this application, the definition of MEOR applies to processes involving the in-situ application of microbial processes and usually excludes EOR processes which merely involve the use of chemical products which are produced in a fermentation plant.
The specific application of microorganisms for EOR in this invention is their use for the selective plugging of zones of high permeability (i.e., thief zones) in petroleum reservoirs. To back up a bit, when water injection is used to recover oil, it is injected downhole in an injection well to move any oil out of the formation to be recovered at a producing well. The water pushes the oil out of the small interstices and pores of the rocks, but it pushes the oil out of the wider spaces and larger pores (i.e., zones of higher permeability) first, leaving the smaller areas still filled with oil. Since petroleum is formed in stratified sedimentary deposits, several distinct layers of oil-bearing sands are usually present over the vertical profile of an oil well. Different layers can vary widely in permeability and porosity, as well as other propeties. Since a waterflood will naturally seek the zone of least resistance (or highest permeability) low permeability zones may be bypassed. After a time, recoverable oil is "watered out" of the high permeability zones, but the low permeability streaks still contain considerable recoverable oil. "Profile modification" provides a way that the residual oil may be recovered from these lower permeability zones. Current technology involves the injection of water-soluble polymers, which selectively enter the high permeability zones. Cationic cross-linking agents, i.e., Cr +3 , Ti +4 , or Al +3 , held in solution by a complexing agent (i.e., citrate) or by oxidation state, are co-injected with the polymer or are swept after the polymer. (See U.S. Pat. No. 4,552,217 to Wu et al.) As the polymer gradually cross-links and gels into a water-insoluble 3-D matrix in the high permeability zones, the waterflood is channeled into zones of lower permeability, thus increasing oil production. There are problems associated with the techniques of profile modification with cross-linking polymers. Such polymers are relatively expensive, they may shear-degrade upon injection at the wellhead and may not penetrate sufficiently before gelling. For this reason, the use of microorganisms may prove promising in profile modification because it may eliminate some of these problems.
As with other techniques, using microbes to plug high permeability zones is not exactly new. Some early researchers are listed in J. Davis, "Petroleum Microbiology" (1967) and more recently there is U.S. Pat. No. 4,558,739 to McInerney et al.; and D. Revus, A Study of Reservoir Selective Plugging Utilizing In Situ Growth of Bacteria to Improve Volumetric Sweep Efficiency, Masters Thesis, Univ. of Oklahoma (1982), P. Kalish et al., The Effect of Bacteria on Sandstone Permeability, 16 Jour. Pet. Tech. 805 (July 1964). C. Brierly et al., Investigation of Microbially Induced Permeability Loss During In-Situ Leaching, Bureau of Mines (NTIS Publication) (April 1982). They use microbes in a variety of ways to enhance oil recovery. Some researchers have used the bacteria that naturally exists in the formation and have simply injected nutrients downhole to stimulate their growth and plug the formation [see U.S. Pat. No. 4,475,590 to Brown and L. Allison, Effect of Microorganisms on Permeability of Soil Under Prolonged Submergence, 63 Soil Science 439 (1947)]. Others have injected bacteria downhole followed by a nutrient solution. Some researchers depend on the biomass of the bacteria for plugging purposes, while others show that exopolymers produced by the bacteria are effective in closing off areas of high permeability.
Another factor in this plugging technique is the size of the organism being injected. Smaller bacteria may penetrate the formation a bit easier than larger bacteria. To that end, the spores of different bacteria may be used for injection to penetrate even deeper. Spores penetrate a reservoir formation easier and become lodged in these permeable zones, so that when they are stimulated to grow by a nutrient solution, they will plug more pores more effectively.
Other problems exist with the nutrient solutions used in the prior art. For example, downhole in a petroleum reservoir, there are conditions that put further constraints on microorganisms. More specifically, connate water, in many formations, has both high concentrations of salt (NaCl), alkaline earth ions (Ca +2 , Mg +2 , Ba +2 ), and heavy metal ions. Such ions can form insoluble precipitates with many of the standard components of bacterial nutrient media. These precipitates can plug the wellbore and prevent injection of cells or nutrients. Furthermore, some of these ions are inhibitory or toxic or microbial cells and some (e.g., Ca +2 ) are inhibitory to production of microbial biopolymer. Bacteria and the nutrient source that are injected downhole must be tolerant to these if they are to survive.
The downhole environment is usually anoxic, unlike the highly oxygenated condition above. To be able to survive and live in both environments, a bacteria must either be shielded from oxygen (which may be difficult and expensive) or must be tolerant to it (e.g., a facultative anaerobe). [Bacteria can be broadly divided into 3 categories based on their ability to utilize and tolerate oxygen: (1) obligately aerobic bacteria, which require molecular oxygen for growth; (2) obligately anearobic bacteria, to which molecular oxygen is toxic; and (3) facultative anaerobes, which can grow either in the presence or absence of atmospheric oxygen. Of the three, facultative anaerobes appear to be the most suitable MEOR candidates, since they can survive exposure of air during storage and injection while retaining the ability to grow well anaerobically.]
The most important ingredient, i.e., the bacteria, sometimes must be selected for these exact conditions that exist in a reservoir. Also, the nutrient's solution has to be tailored to both the bacteria and the reservoir in which it will be injected. All these considerations must be merged together to provide the desired result in plugging the formation thief zones.
OBJECTS OF THE INVENTION
It is an object of this invention to inject a bacterium, in the spore form, into a petroleum reservoir to selectively plug highly permeable thief zones, so that enhanced oil recovery techniques, such as water injection, and other enhanced oil recovery methods will be more effective. It is a further object of this invention to develop novel techniques for spore preparation and injection that do not cause well-face plugging.
SUMMARY OF THE INVENTION
Mature petroleum reservoirs are frequently waterflooded to increase oil production. When a heterogeneous permeability profile exists, the flood poorly sweeps the less permeable zones. "Profile modification" is the enhancement of waterflood efficiency, generally accomplished by the injection of soluble, cross-linkable polymers and a cross-linking agent. The injected polymer selectively enters a highly permeable, watered-out "thief zones" where it sets into an insoluble cross-linked gel, thus channeling the waterflood into the tighter, oil-bearing zones.
The present microbial process should improve sweep efficiency more effectively than is currently possible with injected polymer, and at a significantly lower cost. We have isolated strains of bacteria from saline sediments which are halotolerant (able to live in a moderately salty environment), spore forming, thermotolerant (able to live within a wide temperature range), biopolymer-producing facultative anaerobes; that is, they can grow and produce a viscous biopolymer within a petroleum reservoir. When spores of these bacteria, pretreated in accordance with our techniques, are injected along with the specially designed nutrient solution of this disclosure, they selectively penetrate higher permeability zones. After germination and growth, their biomass, and the exopolymer (the polymer that is secreted outside of the cell) that is produced in-situ, gives the desired profile modification. The effectiveness is superior to injected polymers since the non-viscous spore suspension penetrates further, and the chemicals cost one-tenth that of polymers. Since the polymer is formed in-situ, there is no degradation from injection shear or storage. The novel techniques we have developed for spore preparation, injection, medium and cross-linker formulation and cross-linker delivery overcome problems of injectability, precipitation and control prevalent in the prior art and render the technique operable and practical.
It is also within the scope of this invention to reduce the permeability of underground formations to restrict the spread of contaminant materials. For example, to prevent the flow of hazardous wastes into underground aquifiers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an example of a MEOR continuous testing unit.
FIG. 2 shows the pressure response of cummulative nutrient addition on growing cells in a core.
DETAILED DESCRIPTION OF THE INVENTION
MEOR requires the use of halotolerant, facultative anaerobes since most oil field connate waters are salty and oxygen tension is nil. The cells must be thermophilic (able to grow above 55° C.) or "thermotolerant" (able to grow over a wide temperature range including 40°-50° C. and survive exposure to above 55° C.) since petroleum reservoirs are most frequently within this temperature range. The cells (or spores from the cells) must be small-sized and mobile (or motile) so they can penetrate far into the porous rock. They must have non-fastidious nutrient requirements since laboratory culture media would be prohibitively expensive for field application where huge volumes are injected. The cells must be able to grow and produce the desired product under in-situ conditions of pH, temperature, heavy metal ion concentration, etc. Although some oil-bearing formations are too hot, impermeable or otherwise inhospitable to microbial presence, many are within a temperature range of 20°-80° C. and can support microbial presence and growth. Microbes used for MEOR must also be non-pathogenic and must not produce any animal or plant toxins, since they may be injected near water supply aquifiers.
Although many microbes can utilize hydrocarbons as the sole carbon and energy source, all known species that do this are aerobes which require molecular oxygen for the initial attack on hydrocarbons. If facultative anaerobes are used for MEOR, non-petroleum carbon sources should be supplied. Unless hydrocarbon-utilizing anaerobes can be created through recombinant DNA techniques, sufficient non-hydrocarbon metabolizable components must be present in the petroleum. Suitable carbon substrates are cheap carbohydrates such as molasses and whey and possibly inexpensive synthetic substrates such as methanol. Nitrogen, phosphorous and other nutrients must also be supplied if these are not present in the carbon substrate or in the rock. Nutrients must be supplied at the correct time that microbial activity is desired; loss or absorption of nutrients would be an economic debit.
Facultative anaerobic halophilic, or halotolerant, thermotolerant bacteria may be used to achieve profile modification through the production of exopolymer and/or the growth of cells within highly permeable rock, thereby decreasing the permeability of this rock. The exopolymer forms an insoluble matrix within the rock pores which is resistant to bio-, shear, and thermal degradation. Ionic or other cross-linking agents are preferably used to enhance polymer stability in-situ. However, since the polymer is produced in-situ and not injected from the surface (where water solubility is essential), such cross-linking agents are an optional feature of our invention.
The spores which are injected are small enough to penetrate high permeability zones, but not the oil-bearing low permeability zones. The spores are prepared by growing cells on a sporulation medium to give a spore concentrate (10 9 spores/ml). This spore suspension is stable for long periods of time and is pretreated (by aging, lysozyme or other enzyme treatment) and filtered to remove cellular debris and improve injectability. The spore suspension may be diluted 1:1000 with nutrient or brine prior to injection, i.e., the injected spore concentration is approximately 10 6 /ml.
The Bacteria
The bacteria of choice have been described in U.S. application Ser. No. 23,070 which is herein incorporated by reference. They are two strains of Bacillus licheniformis (dubbed SLS-1 NRRL No 18179 and Salton-1, NRRL No. 18178 ) and possess the following characteristics: motility; facultative anaerobiasis; exopolymer production; sporulation, thermotolerance, and halotolerance. They will alter the profile of a petroleum reservoir by their own mass and their exopolymer when they are lodged in zones of high permeability. Since they are motile the bacteria may reach further into the permeable zone.
The biopolymer may be produced in larger quantities if one or a mixture of the following ingredients is added directly to the culture medium: phosphate in the form tri-polyphosphate, citric acid, Al +3 (as aluminum citrate), or ammonium nitrate. Polyphosphate is an essential component of the preferred medium, in a salt form such as sodium, potassium or ammonium tri-polyphosphate.
BENCH-SCALE CONTINUOUS CORE TESTS
Automated Core Test Apparatus
An automated bench-scale laboratory unit was operated continuously for performing core 2 and packed column testing to demonstrate the feasibility of this MEOR approach. A simplified flow schematic of the unit is shown in FIG. 1. Six core experiments can be run simultaneously and independently. Oil 4 and brine 6, bacteria and nutrients 8 were fed through separate feed pumping systems (oil was pumped through pump 10 and brine, bacteria, and nutrients through pump 12). Sterile brine 6, bacterial cells (or spores) and nutrients 8 were pumped through 0.125" OD tubing using a Milton Roy or a peristaltic pump 12. To maintain anaerobic conditions, a small purge of nitrogen was bed into each vesel 6 and 8. Feed rates, depending on predetermined experimental conditions normally ranged from 0.03-1.0 ml/min. This has a field correlation feed rate of 0.3-11 linear ft/day. For temperature control, all cores 2 were placed in a constant temperature incubator 14. All experiments were conducted at 40° C. (104° F.). Differential pressure was recorded using tranducers 16 with appropriate diaphragms. In most experiments, pressure taps 18 were located at intervals along the length of the core 2. This was accomplished by drilling a 0.125" OD hole into and through the resin and epoxy (on the surface of the core 2) and into the sandstone of the core 12 such that fluid transmitted through the core 2 flowed out the hole. The holes in the resin were tapped and threaded and fitted with gyrolock connectors. Nylon tubing was connected from these fittings to a pressure transducer. Pressure signals were processed and converted to a digital signal by a signal demodulator 20. Calibration of the transducers 16 were performed using a preset nitrogen calibration pressure setup. A computer 22 continuously monitored (and every 30 minutes printed and logged to hard copy or floppy disk) the cores' pressure and other readings. The printout gave a time-pressure log so as to follow the pressure differential for the entire length of each core 2. This enabled an accurate compilation of pressure measurements for the entire duration of each core experiment independently. Flow rates were measured both from time-pump feed rates and from effluent product collection rates; these rates were continuously taken. The effluent samples were collected and continuously using a fraction collector 24.
CORE PREPARATION
Berea sandstone cores, obtained from Cleveland Quarries (Amherst, Ohio) were of 2" diameter and received as cylinders of specified lengths and permeabilities. A specified core is coated with epoxy and cast in a resin mold. After cutting the core to a designated length and facing the ends, it was placed in a core holder to be attached to the continuous flow apparatus and then vacuum saturated with brine for an accurate pore volume determination. An oil-brine saturated core was prepared by pumping several pore volumes of brine followed by adding several pore volumes of crude oil to a irreducible water saturation. Brine was then pumped through the core until no more oil was observed in the effluent. At this time, initial brine permeability was determined. For most experimental runs, the flow tubing, fittings, and valvings were disinfected and then completely flushed with sterile brine before each startup. Calculations for % porosity and % pore volume of oil saturation were also determined before starting each core experiment.
INJECTION OF CELLS AND NUTRIENT
Depending on the purpose of a designated experimental run, a core may or may not be oil saturated. The sequence of additions for an experiment are as follows:
1. Brine injection to determine permeability.
2. Add 0.3-1.0 pore volumes of cell or spore suspension at a concentration of approximately 10 6 cells/ml.
3. Add 0.3-1.0 pore volumes of specifically formulated nutrient solution; thous could be added with the cells (as has been demonstrated).
4. A cross-linker (Al +3 or Cr +3 ) could also be added either with a waterflush or in combination with cells and/or nutrient material. The concentration of cross-linker would be about 1000 ppm. Such cross-linker is preferably held in solubilized form by polyphosphate salt.
5. Incubation ("lock in") for 5-10 days.
6. Commence brine addition or add a second nutrient and/or cross-linker batch. At this time a check is also made for permeability reduction and effluent samples are analyzed for biopolymer concentration.
7. Incubation (repeated).
8. Steps 6 and 7 can be repeated.
9. Final brine addition to check for lasting permeability reduction.
MONITORING PERFORMANCE DURING CORE RUNS
Cell growth along with biopolymer production for the enhancement of lasting permeability reduction is the ultimate goal of our MEOR process. Monitoring the extent of this growth and production during an on-going core experiment can be accurately accomplished by recording gas pressure buildup as cells grow, calculating and evaluating pressure gradients and overall permeability calcuations (while pumping) during sequential additions, and by performing analyses on effluent samples taken; i.e., cell plate count, biopolymer concentration, and residual sucrose (the most frequently used carbon source) concentration, etc. Several demonstration experiments were completed using this basic apparatus.
EXAMPLE 1 (Nutrient Utilization)
FIG. 2 shows the pressure response of cumulative nutrient addition on growing cells in the core. Previously added cells (to the core) were fed 4 separate batches of nutrient with approximately five days' incubations between each addition. Separate curves are shown for the pressure response at: (1) at core's inlet, (2) 30% length from the inlet, and, (3) 70% length from the inlet. As shown, pressure response increases as a function of time as a result of step-wise nutrient addition to the core's previously added cells. The increase in static pressure during incubation is due to cell gas production (CO 2 ) while the increase in dynamic (pumping) pressure with each injection is due to the accumulation of cell mass/biopolymer throughout the length of the core. It has been repeatedly demonstrated that when core effluent cell count and nutrient sucrose utilization increase, a desired reduction in core permeability results (as is shown here; i.e., 367 millidarcy or md to 58 md).
EXAMPLE 2 (Long Distance Transport)
To verify the present of in situ produced biopolymer at extended distances from the injection site, a 40 ft. packed Berea "slim tube" (crushed sandstone) was constructed with pressure transducers and sampling ports at 10 intervals. The initial brine permeability of the slim tube (76 cc pore volume) was 6.7 d (6700 md) and after feeding 2.3 pore volumes (abbreviated PV) of 6×10 7 cells/ml at a rate of 0.11 ml/min (80 ft/day) for 17 hours, the sample port at the end (40 ft. length) of the tube showed 10 4 cells/ml of cells identical to those fed and 113 ppm biopolymer that these cells produced. As time and subsequent additions proceeded, the overall permeability was reduced to 0.4 d (400 md), and the biopolymer concentration at the end of the slim tube in the effluent was measured at 1222 ppm.
This experiment enabled measurements of polymer production-pentration and adsorption over a long distance corresponding to a "thief zone" in the field. The results show that the cells and subsequently produced biopolymer completely penetrated to the end of the tube, demonstrating the effectiveness of the MEOR technique. Total "plugging" of the slim tube is further evidenced by the following points:
1. Throughout the course of the experiment, the feed pump rate had to be reduced. The progressively slower rate was needed to stay below the pressure limitations on the equipment. The pressure buildup and slower feed rate demonstrates the effectiveness of biopolymer buildup in the total length of the slim tube.
2. Permeability reduction for the overall length of the slim tube is 94%.
3. Significant increases in the rate of change of pressure differentials occurred during the duration of the run.
In the "Slim Tube" experiment product samples were taken at specified times and locations along the packed core during the course of the experiment. The 40 ft. Berea-packed column had both transducers and sampling ports at the inlet and each subsequent 10 ft. interval.
These results show that overall permeability reduction continues to increase due to the increase of in situ produced biopolymer throughout the length of the 40 ft. slim tube. By continually monitoring pressure response and the concentration of biopolymer at the sample ports, a good representation of experimental progress (for permeability reduction) was continually available.
This experiment also demonstrated that the Salton bacteria cells will transport through high permeability Berea core at a reasonable concentration for process effectiveness.
CELL AND SPORE PENETRATION EXPERIMENTS
EXAMPLE 3 (Cell Injection Phase)
A cell penetration experiment using a moderately permeable Berea sandstone core (146 md, 9 cm in length) and a highly permeable core (1361 md, 9 cm long) was conducted to measure the flow properties of the cell suspension. Three pore volumes of 4×10 5 cells/ml were added to each core. High retention of the cells on the sandstone with each core resulted; i.e., essentially 100% of the cells injected were retained on the respective cores.
A second cell migration experiment was run using a 9 cm long×5 cm diameter Berea core to obtain more information on Salton cell penetration. Again, the majortiy of the cells were retained within the core. The following material balanced was calculated:
Total Liquid recovery=99.4%
Total vegative cell count feed=1.06×10 8 cells/ml
Total recovered cell count=3.06×10 5 cells/ml
This showed that greater than 99% of the feed cells were retained on the core. From these two tests it became apparent that spores, not cells, should be the penetrating/migrating species through the sandstone. The cells appear either too large and/or adhesive to the core material and cannot travel through the network of rock pores for any appreciable distance.
EXAMPLE 4 (Spore Pretreatment)
When cells of Bacillus bacteria are induced to sporulate, microscopic observation of fresh spores reveals small, optically refractile spores plus considerable adhering cell debris. When such "fresh" spores were diluted to approximately 10 6 spores/ml and injected into a Berea core of 1000 md permeability, poor injectability was obtained with almost immediate face plugging. Visual observation revealed a film of sticky proteinaceous matter on the face of the core. The concentrated spore suspension was then treated by adding 1 mg/ml lysozyme at 40° C. for 2 hours. The spores were then filtered through Whatman No. 1 paper. Microscopic observation revealed that the previous adherent material was no longer present. Subsequent injection of these treated spores into a core gave good injectability with no buildup of any faceplugging layer.
It was later observed that aging of a fresh spore suspension for a period in excess of two months has a beneficial effect similar to that which can be obtained with lysozyme in a few hours.
EXAMPLE 5 (Spore Injection)
Spore transport and spore adsorption/desorption characteristics were studied in a high and a low permeability core. A 10 7 /ml concentration of pretreated spores was injected into each core for 23.33 hours. The low permeability core received 18.1 pore volumes (PV) of spores followed by the same amount of brine; the high permeability core received 8.5 PV spores followed by the same amount of brine.
TABLE 1______________________________________Low Permeability High PermeabilityCore Core______________________________________9.2 cm Length 16.3 cm5.1 cm Diameter 5.0 cm35.0 ml Pore Volume 74.4 mlPERMEABILITY(feed rate - 5.2 ft/d (field))123 md Brine 800 md105 md 50% Spores Added 800 md82 md 100% Spores Added 686 md______________________________________
The pressure drop data for the high permeability core indicate that the spores penetrated farther than in the low permeability core. After completing the material balance for the high permeability core, the following conclusions have been made:
1. Breakthrough of injected spores in the core effluent occurred at 0.5 PV which is a measure of the "inaccessible pore volume" for spore transport.
2. Over the course of the experiment, spore concentration in the effluent increased from 4×10 2 to 1.8×10 6 spores/ml.
3. 95% of the injected spores were retained by the high permeability core even after extensive brine flushing. A negligible concentration of spores was detected in the effluent during the injection and subsequent brine flushing from the low permeability core.
Significant overall permeability reduction was observed in both cores but the pressure drop data suggest some spore accumulation at the front of each core.
EXAMPLE 6 (Spore Injection)
In proposed field application, large volumes of fluids will pass through the well bore surface where any face plugging mechanism is a concern. A Salton spore suspension (conc.=1.3×10 6 spores/ml) was injected into a small cross section, low permeability (141 md) Berea core at a rate of 1 PV/hr in two operational modes; i.e., continuous recycle and straight-through single pass.
TABLE 2______________________________________PERMEABILITIES (recycle)1. Brine 141 md2. After 138 pv 140 md Spores Added3. After 337 pv 132 md Spores AddedPERMEABILITIES (single pass)1. After 91 pv 124 md Spores Added (428 pv cum.)2. After 151 pv 115 md Spores Added (488 pv cum.)3. After 184 pv 110 md Spores Added (521 pv cum.)______________________________________ Core Parameters: L = 8.5 cm D = 1.4 cm PV = 6.5 ml
The results of Table 2 show the permeability calculations for the single pass and recycle experiments. Further it was observed that no feed spores were detected in the effluent sent back to recycle. It can thus be safely assumed that for the 365 hours of recycling 337 PV of spores, essentially 100% of the spores remained on the core. Also, by carefully reviewing the pressure drop data along the length of the core, the predominant weight fraction of the feed was in the very front (face) of the core. This almost certainly accounts for the 6% permeability reduction after 337 PV were recycled.
The same core was then used for straightthrough, single pass operation and was continuously injected with 184 PV of a 1.35×10 6 /ml spore feed. Again, no spores were detected in the effluent. After 184 PV were added in the single-pass mode and 337 PV in the recycle mode (521 total PV added) a 22% permeability reduction was measured. After feeding over 500 PV of the spore suspension, no indication of any face plugging was evident, i.e., only a +0.3 psig pressure change at the face of the core.
EXAMPLE 7 (Spore Retention)
Spores were injected in a single pass to a Berea core of relatively high starting brine permeability (approximately 2100 md). The essential core parameters are listed below:
Core length=10.85 cm
Diameter=5.04 cm
Pore volume=49.7 ml
Only two pressure transducers, inlet and outlet, were attached to the core; 145 PV of spores were injected (average conc.=1.9×10/ 6 ml) into the core over 339 hours at an average feed rate of 0.36 ml/min. The results show that spore breakthrough (2.5×10 2 spores/ml) occurred after 20.7 ml (0.42 PV) and the concentration of spores continued to increase during pumping to an effluent concentration of 5.6×10 5 spores/ml at the conclusion of the experiment. An accurate material balance was completed for this run as follows:
Total spores fed (145 PV)=1.43×10 10
Total spores recovered (effluent)=5.73×10 8
Spores recovered=4%
Spores remaining on core=96%
This result indicates that the majority of the spores are retained by the core after feeding 145 PV. Permeability has continued to decrease throughout the duration of the run from approximately 2100 md at the beginning to 60 md at the end of the experiment. No plugging was observed at the core face; injection rate decreased only 13%; and the injection pressure increased less than 1 psig.
It has been experimentally shown that under conditions of our invention, cells and spores can easily penetrate Berea core material. These conditions are:
(1) Use of selected bacteria such as our SLS and SALTON-1 strains which form small, compact spores and motile cells.
(2) Pretreatment of spores with a proteolytic enzyme such as lysozyme (or with autogenous proteases generated by long-term aging of spores) so as to remove adhering cell debris and sticky proteins.
(3) Use of polyphosphate ion in the nutrient solution which chelates and prevents precipitation with ions present in the connate brine such as calcium and magnesium.
In the Examples, cells and viscous biopolymer were evident the total length of the core. Since the experiment used a high permeability core, it is safe to say that field "thief zones" can be altered successfully by this microbial profile modification process. In no experiments where our preferred precedures have been used has there been any significant face plugging. Cells and spores have easily gone into the respective cores of low or high permeability. If continuous flow measurements are taken in low permeability cores using cells or spores, little or no penetration is observed by pressure drop data, but no face plugging is evident after many pore volumes of nutrient or recycle solution has been added. In contrast to this, continuous injection experiments of spores into high permeability cores, develop a gradient of spore concentration (by observing pressure drop data) with some fraction (e.g., 5%) of feed spores collected at the effluent after a suitable period.
Our proposed MEOR process will give the germinated cells time to grow, multiply, and produce biopolymer. This "incubation" time is, if all components have been properly selected, less than a week in duration. We have observed substantial incubation gas production over the total length of core, cell growth followed by biopolymer production and lasting permeability reduction to continual brine flushing.
The magnitude of profile modification with our process can easily be as low as 65% permeability reduction and as high as 95%. The level of reduction depends on several factors; i.e., beginning permeability, amount of bacteria added, incubation time, and obviously, proper nutrient. The ease of reducing permeability seems to increase when using cores that are in excess of 600 md, which is desirable since the "thief zones" we wish to plug are high permeability. Also, a certain level (concentration) of cells may be necessary before substantial amounts of biopolymer are formed and permeability is reduced.
The first amount of injected cells may act as a "conditioner" for the sandstone, enabling further spore/cell addition to perform their required tasks, i.e., germination, reproduction, and biopolymer production. Incubation times of 5-10 days allows processing steps to be completed. Nutrient composition and the quantity added are "critical" process requirements. All nutrient formulations must be optimized to maximize biopolymer production. Also, when more than one addition of nutrient is made, more than one cell/spore addition may be required to adhieve maximum permeability reduction. Alternatively profile modification can be accomplished by injecting the nutrient solution into an injection well and the spores or cells or mixtures thereof into an adjacent production well, or vice versa. If all steps have been achieved to ensure significant profile modification, permeability reduction will be more resistant to erosion due to continual water flooding and elapsed time.
Sine many modifications and variations of the present invention are possible within the spirit of this disclosure, it is intended that the embodiments that are disclosed are only illustrative and not restrictive. Reference is made to the following claims rather than the specific description to indicate the scope of the invention. | The present invention is a bacteria and its use in a Microbial Enhanced Oil Recovery (MEOR) process. Any one of two newly isolated strains of bacteria are injected downhole in a petroleum reservoir to modify its profile. This bacteria has the capability to plug the zones of higher permeability within the reservoir so that a subsequent waterflood may selectively enter the oil bearing less permeable zones. The injected water is used to drive this oil to an area where it may then be recovered. | 2 |
BACKGROUND OF THE INVENTION
Major problems exist in producing oil from heavy oil reservoirs due to the high viscosity of the oil. Because of this high viscosity, a high pressure gradient builds up around the well bore, often utilizing almost two-thirds of the reservoir pressure in the immediate vicinity of the well bore. Furthermore, as the heavy oils progress inwardly to the well bore, gas in solution evolves more rapidly into the well bore. Since gas dissolved in oil reduces its viscosity, this further increases the viscosity of the oil in the immediate vicinity of the well bore. Such viscosity effects, especially near the well bore, impede production; the resulting waste of reservoir pressure can reduce the overall primary recovery from such reservoirs.
Similarly, in light oil deposits, dissolved paraffin in the oil tends to accumulate around the well bore, particularly in screens and perforations to admit oil into the well and in the oil deposit within a few feet of the well bore. This precipitation effect is also caused by the evolution of gases and volatiles as the oil moves through the oil deposit into the vicinity of the well bore, thereby decreasing the solubility of paraffins and causing them to precipitate. Further, the evolution of gases causes an auto-refrigeration effect which reduces the temperature, thereby decreasing solubility of the paraffins. Similar to paraffin, other condensable constituents may also plug up, coagulate or precipitate near the well bore. These constituents may include gas hydrates, asphaltenes and sulfur. In certain gas wells, liquid distillates can accumulate in the immediate vicinity of the well bore, which also reduces the relative permeability and causes a similar impediment to flow. In such cases, accumulations near the well bore reduce the production rate and reduce the ultimate primary recovery.
Electrical resistance heating has been employed to heat the reservoir in the immediate vicinity of the well bore. Basic systems are described in Bridges U.S. Pat. No. 4,524,827 and in Bridges et al. U.S. Pat. No. 4,821,798. Tests employing systems similar to those described in these prior patents have demonstrated flow increases in the range of 200% to 400%.
Various proposals have been made over the years to use electrical energy for oil well heating, in a power frequency band (e.g. DC or 60 Hz AC), in the short wave band (100 kHz to 100 MHz), or in the microwave band (900 MHz to 10 GHz). Various down-hole electrical heat applicators have been suggested; these may be classified as monopoles, dipoles, or arrays of antennas. A monopole is defined as a vertical electrode whose length is somewhat smaller than the depth of the deposit; the return electrode, usually of large diameter, is often located at a distance remote from the deposit. For a dipole, two vertical, closely spaced electrodes are used and the combined extent is smaller than the depth of the deposit. These dipole electrodes are excited with a voltage applied to one relative to the other.
In the past, radio-frequency (RF) dipoles have been used to heat earth formations. These RF dipoles were based on designs used for the radiation or reception of electromagnetic energy in the radio frequency or microwave spectrum. In an oil well an RF dipole is usually in the form of a pair of long, axially oriented, cylindrical conductors. The spacing between these elongated conductors is generally quite close at the point where the voltage is applied to excite such antennas. The use of such dipoles emplaced vertically have been described, as in Bridges et al. U.S. Pat. No. 4,524,827, to heat portions of the earth formations above the vaporization point of water by dielectric absorption of short-wave band energy. However, such arrangements have been found to be costly and inefficient in heating moist earth formations, such as heavy oil deposits, because of the cost and inefficiency of the associated short-wavelength generators and because short wavelengths do not penetrate moist deposits as well as the long wavelengths associated with power-frequency resistive heating systems. Further, if an RF dipole is used to heat moist deposits by resistance heating the heating pattern is inefficient because the close spacing of the cylindrical conductors at the feed point creates intense electric fields. Such high field intensities create hot-spots that waste energy and that cause electrical breakdown of the electrical insulation.
Where heating above the vaporization point of water is not needed, use of frequencies significantly above the power frequency band is not advisable. Most typical deposits are moist and rather highly conductive; high conductivity increases losses in the deposits and restricts the depth of penetration for frequencies significantly above the power frequency band. Furthermore, use of frequencies above the power frequency band may require expensive radio frequency power sources and coaxial cable or waveguide power delivery systems.
Bridges et al. U.S. Pat. No. 5,070,533 describes a power delivery system which utilizes an armored cable to deliver AC power (2-60 Hz) from the surface to an exposed vertical monopole electrode. In this case, an armored cable for the kind commonly used to supply three-phase power to down-hole pump motors is employed. However, the three phase conductors are conductively tied together and thereby form, in effect, a single conductor. From an above-ground source, the power passes through the wellhead and down the cable to energize an electrode embedded in the pay zone of the deposit. The current then returns to the well casing and flows on the inside surface of the casing back to the generator.
A monopole design, such as disclosed in U.S. Pat. No. 5,070,533, represents the state of the art to install electrical resistance heating in vertical wells. However, the use of electrical heating arrangements like those employed for vertical wells introduces major difficulties in horizontal well completions. These difficulties must be addressed to make electrically heated horizontal wells practical and economical.
Drilling technology has advanced to a point where horizontal well completions are commonplace. In many cases, the length of a horizontal producing zone can be over several hundred meters. Horizontal completions often result in highly economic oil wells. In some oil fields, however, the results from horizontal completions have sometimes been disappointing. This may occur for some deposits, such as certain heavy oil reservoirs where a near-wellbore, thermally-responsive, flow impediment or skin-effect forms. In such cases, the use of electrical, near-wellbore heating offers the opportunity to suppress skin effects. This can make otherwise marginal heavy-oil or paraffin-prone oil fields highly profitable. To use electrical heating methods, existing vertical well electrical heating technology must be redesigned and tailored for horizontal completions.
Long horizontal well completions, or even long vertical well installations, that employ near well-bore electrical heating introduce several important problems not adequately resolved by application of the aforementioned vertical well electrical heating technology. The spreading resistance of the electrode (the resistance of the formation in contact with the electrode) is approximately inversely proportional to the length of the heating electrode. Typically, the spreading resistance of an electrode a few meters long in a vertical well is in the order of a few ohms. This electrode is supplied with power via a cable or conductor that usually has a resistance of a few tenths of an ohm. In the case of a vertical well, the resistance of the cable, the spreading resistance of the small electrode in the pay zone and the spreading resistance of the casing used as the return electrode are all in series. In this case the power dissipated in each resistance is proportional to the value of the resistance. (For a vertical well, the spreading resistance of the casing can be neglected.) For this example, only about ten percent of the power applied at the wellhead is dissipated in the power delivery cable.
In the case of a long horizontal electrode, however, the spreading resistance may be only a few tenths of an ohm because of the long length of the horizontal electrode. This value can be very small compared to the series resistance of the power delivery conductor. The spreading resistance of the horizontal electrode can be comparable to the spreading resistance of the casing, if the casing functions as the return electrode. Because the spreading resistance of the electrode is comparable to the series resistance of the return electrode and also to the resistance of the cable, only a small fraction of the power delivered to the wellhead will be dissipated in the deposit.
Another problem with applying vertical well electrical heating technology horizontally is the large power requirement implied by the long lengths of possible horizontal wells. For example, a producing zone of six meters depth with a five meter vertical electrode may exhibit an unstimulated flow rate of 100 barrels per day. Typically, the vertical well could be electrically stimulated with about 100 kilowatts (kW) to produce up to about 300 barrels of low-water content oil per day. For this example, the energy requirement at the wellhead would be about eight kilowatt hours (kWh) per barrel of oil collected. Assuming a power delivery efficiency of 85%, and a thermal diffusion loss of 20% from the heated zone to adjacent cooler formations, the power delivered to the deposit to increase the temperature of the nearby formation and ingressing oil to a temperature of 55° C. would be in the order of five kilowatt hours (kWh) per barrel. The power dissipation along the vertical electrode would be about 20 to 25 kilowatts (kW) per meter. This rather high power intensity, 20 kW per meter along the electrode, assures that the formation at least several meters away from the well bore will be heated to a temperature where the viscosity is reduced by at least an order of magnitude, thereby enhancing the production rate. The thermal diffusion of energy to adjacent non-deposit formations is suppressed by the compact shape of the heated zone, which has a low surface area to volume ratio and which experiences a high heating rate.
On the other hand, a single screen/electrode combination in a horizontal completion well may be as long as 300 meters. Based on vertical well experience, the unstimulated flow rate could be about 300 barrels per day with the expectation that the electrically stimulated rate would be increased to about 900 barrels per day. About 300 kW at the wellhead would be needed to sustain this stimulated flow, assuming conditions similar to the vertical well example discussed above. Further, assuming that the vertical well technology is applied to a horizontal well completion, the power dissipation along the horizontal electrode would be about one kW per meter as opposed to 20 kW per meter in the deposit for the vertical electrode.
In the above example there is a one kW dissipation per meter in the deposit along the horizontal screen/electrode, as opposed to the 20 kW dissipation per meter for the vertical screen/electrode. This low power intensity along the electrode/screen suggests that the temperature rise in the deposit along the horizontal screen may be much lower than that along the screen of a vertical well. The principal reasons are that the surface area to volume of the heated zone is much larger than for the vertical well, and the heating rate is too slow, enhancing the heat loss by thermal diffusion to the cooler nearby formations. The heat from this one kW per meter dissipation may be insufficient to raise the temperature of the heated zone to where the viscosity of the oil is reduced enough to afford worthwhile flow increase. This suggests that the well head power requirement per barrel of oil of eight kWh that was based on experience with vertical wells may be too low for a horizontal well with a long uninterrupted electrode.
An additional problem is that the electrical current distribution injected into the deposit from a long horizontal electrode may also be highly non-uniform. Similar non-uniform distributions have resulted in hot spots near the tips of vertical electrodes and has necessitated the use of expensive, high performance electrical insulation materials near the electrode tips of vertical wells. Similar hot spots can be expected to occur for horizontal completions, especially if the delivered power is in the order of several hundred kilowatts. Aside from the hot spots, such non-uniform heating along the electrode can result in inefficient use of electrical energy.
Another problem is that of heterogeneity of the horizontal formation through which the horizontal well is completed. If the resistivity of the formation varies along the length of the completion, greater heating rates may occur in regions where the resistivity is low. This could be a serious problem, since the location of the producing zone may not be accurately characterized. For example, if a horizontal well unknowingly is directed into a barren formation that has a low resistivity, most of the electrical heating power may be dissipated in this low resistivity barren region, thereby creating a hot spot and lowering the overall efficiency.
STATEMENT OF THE INVENTION
The overall objective of this invention is to configure the geometry and to control the excitation of the electrodes, in horizontal wells, such that substantial benefits from the electrical heat stimulation of horizontal wells can be more fully realized.
Specifically, an array including a series of relatively short horizontal electrodes is deployed in the horizontal well completion; the excitation, spacing and lengths of these smaller electrodes are chosen such that substantial resistance is presented to the power delivery conductors.
Groups of short electrodes are deployed so that at least one of the electrodes in the group, at any given time, serves as the return current electrode for one or more of the other electrodes in the group. Further, the excitation, spacing and lengths of these electrodes are chosen such that preselected regions of enhanced power dissipation and temperature rise occur along the horizontal borehole.
The excitation and geometry of preselected electrodes are controlled such that the power delivery efficiency is enhanced, thermal diffusion losses to adjacent formations are reduced, and the applied power more effectively utilized to stimulate the production of oil and gas.
The excitation and spacing of the short, iterated electrodes can be used to control the current distribution along the electrodes so as to suppress hot spots.
The spacing between electrodes is chosen to be large compared to the diameter of the electrodes to suppress excess heating effects between adjacent excited electrodes.
The excitation, positioning and spacing of the short electrodes is chosen such that an electrically stimulated production zone associated with one region of enhanced dissipation and temperature rise does not substantially overlap an adjacent electrically stimulated production zone.
In line with the foregoing objectives, the following specific benefits for horizontal, electrically heated wells utilizing the present invention are noted:
The amount of power needed to realize a significant economic benefit from electrical heating near the production borehole in a horizontal well can be reduced to economically attractive values; specifically, the capital equipment costs of the above-ground electrical equipment can be economically attractive.
The resistance presented to the power delivery conductors by the electrode assembly can be made sufficiently high to realize an acceptable power delivery efficiency with conventional cable or conductor designs.
The energy lost to adjacent formations by thermal diffusion can be reduced, thereby permitting more effective and efficient use of the applied electrical power.
The temperature rise in the formations near the electrodes can be made great enough to make electrical stimulation heating effective near the well bore.
The power requirements can be reduced without significantly affecting the electrically enhanced production rates.
Hot spots caused by excessive power dissipation near one or more electrodes can be suppressed to realize increased reliability and efficiency.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph that presents the approximate flow-rate enhancement for horizontal electrodes radiating from a vertical shaft or borehole and emplaced in a low API heavy oil deposit for one and two radials. The flow rate is normalized to that for a vertical well and the length of the horizontal borehole is normalized as a function of its length relative to the height of the producing formation;
FIG. 2 is a simplified illustration of a "transmission line" characterization of a horizontal electrode emplaced in a heavy oil deposit between two highly conductive layers;
FIG. 3 is a simplified illustration of a series of iterated electrodes, showing just two electrodes, for a horizontal well completion;
FIG. 4 is a longitudinal sectional view of a portion of a horizontal well completion employing a series of iterated electrodes;
FIG. 5 is a cross section taken approximately along line 5--5 in FIG. 4;
FIG. 6 is a graph that presents the pressure profile as a function of the radial distance from the well for a heavy oil well in Canada. Two profiles are presented: one for unstimulated production and the other for electrically stimulated near-well bore heating; and
FIG. 7 is a graph that presents an estimated pressure profile for an iterated electrode horizontal well configuration as a function of distance along the horizontal borehole.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A key factor is that power consumption is approximately proportional to the length of a horizontal screen/electrode, whereas an increase in flow of oil is not proportional to the length of the screen/electrode.
There are several methods of completing horizontal wells. One method is by forming a vertical shaft in a heavy oil deposit. Then, horizontal well bores are drilled radially outwardly up to about thirty meters from the vertical shaft. Studies have been conducted on the benefits of extending the length of such radial boreholes as well as increasing the number of radial boreholes. More typically, a single horizontal well can be realized by slowly deviating the angle of the borehole from vertical to horizontal on a large radius and guiding the drill to pass horizontally through the main portion of the deposit. Such apparatus typically can exhibit horizontal penetration of the reservoir in a range of one hundred to five hundred meters.
In the case where radial well bores are formed from the shaft of a vertical well bore, the benefits are not proportional to the length of the radials drilled outwardly from the vertical well bore. FIG. 1 illustrates the flow rate enhancement as a function of either one horizontal (radial) bore, curve 13, or two radial bores that are 180 degrees opposed, curve 14; the horizontal length of each horizontal bore is normalized to the thickness of the deposit. Note that increasing the length of just one radial, curve 13, by a factor of four, only increases the production by a factor of about 2.5. Adding an additional radial in the opposite direction, curve 14, thus effectively increasing the length of the initial radial by a factor of two, further increases production by only approximately 32%. The reason is that zones of influence from adjacent horizontal bores (radials) overlap so that the production that would be realized from one radial completion is partially captured by the installation of an adjacent radial completion. Also, the ends of a horizontal completion tend to produce more oil than a similar section in the middle of the same horizontal completion. This occurs because the tips of the horizontal completion are exposed to a much larger section of the deposit and therefore have a much larger zone of influence than segments in the middle of the bore length.
Studies have demonstrated that the total production is not doubled if an additional well is installed too close to another well. The key to increasing production in a given reservoir by additional wells is to space them sufficiently such that zones of influence of adjacent wells do not overlap significantly.
The data shown in FIG. 1 are an important aspect of optimal design for electrically heated horizontal wells. The problem is that the design complexity and power required by an electrically heated well is nearly directly proportional to the length of a continuous horizontal heating electrode. On the other hand, the increase in flow rate is not proportional to the length of the electrode, but rather to some reduced fraction of that length. To offset this, groups of shorter electrodes, each of which creates a local region of enhanced dissipation and temperature rise, are deployed along the horizontal borehole, in accordance with the present invention. Each of these groups should be spaced such that the production zones of influence created in the high temperature regions do not overlap substantially. However, this spacing should still be close enough such that the reservoir pressure near the horizontal borehole at any position is maintained at some small incremental value above the pressure within the horizontal screen/electrode. This small incremental value should be a small fraction of the difference between the shut-in reservoir pressure and the pressure within the horizontal screen/electrode.
An examination of FIG. 1 shows that increasing the length of a horizontal screen electrode beyond about twice the thickness of the oil deposit does not produce a significant proportionate increase in oil production. Further examination of this data shows that the spacing between heated regions should be equal to or larger than 0.3 times the thickness of the deposit and preferably greater than one-third the thickness to prevent overlap in production zones of influence.
Additional problems arise in the case of a continuous horizontal electrode that is emplaced in a thin horizontal deposit. Such an arrangement can cause the resistance presented to the electrical power delivery system to be too low for efficient power delivery. In addition, as current flows along a screen/electrode some of the current leaks off into the over burden and the under burden. Such an arrangement is illustrated in FIG. 2. FIG. 2 shows an electrode 18 immersed in a moderately high resistivity oil reservoir 19 having a low height (depth) H. The reservoir 19 is located between two highly conductive formations, the overburden 20 and the under burden 21. Textbook relationships can be used to analyze the input impedance and the propagation losses along the horizontal electrode 18. General transmission line equations were used to compile Table 1 (see Table 1.23 and page 44-47 in "Fields and Waves in Communications and Electronics" by Ramo et al., 1965, J. Wiley and Sons, New York). Also, the characteristic wave impedance of a single cylindrical electrode between two conducting planes was used from "Reference Data for Radio Engineers", page 22-23, Howard Sams, ITT, New York, 1968. Calculations were made that used measured values of the series impedance of a steel tube and an aluminum tube. These results are illustrated in Table 1 for three cases where the resistivity of the reservoir is ten ohm-meters. The first case is for 60 Hz excitation using a casing diameter D of 4.5 inches (11.4 cm) for steel casing as the electrode and a spacing H of four meters between highly conducting barren layers 20 and 21 (see FIG. 2). In this example the series impedance of the casing was measured to be in the order of 10 -3 ohms per meter. By reducing the operating frequency to six Hz, the skin effect of the high permeability of the steel was reduced, and this reduced the series impedance of the tubing to about 10 -4 ohms per meter. For comparison, an aluminum tube was measured to have a series impedance of 10 -5 ohms per meter. The calculations for Table 1 were based on a horizontal electrode equally spaced between two conducting layers in a ten ohms per meter deposit. The deposit is four meters thick (H, FIG. 2) and the conductor or electrode is equally spaced between the highly conducting layers 20 and 21 of over burden and under burden (FIG. 2).
TABLE 1______________________________________Horizontal Electrodes 18, Deposit Ten Ohm-meters, H FourMeters, Low Resistivity Burden Layers 20,21 (See FIG. 2) 6 Hz 60 Hz 6 Hz Alum., Steel, Steel, D = 15 cm 0D D = 11.4 cm D = 25 cm (12 cm 1D)______________________________________Travel path along 23 m 60 m 223 melectrode for 50%of initial heatingrateInput Impedance of 0.2Ω 0.083Ω 0.02Ωelectrodes for above50% path______________________________________
It is seen from Table 1 that a current leaking or stripping effect occurs that limits the effective heating reach of a steel electrode to no more than sixty meters and of an aluminum electrode to no more than two hundred twenty three meters. The impedance presented to the power delivery system is quite low; it ranges between about 0.08 and 0.02 ohms for a six Hz excitation frequency for steel and aluminum respectively.
If the resistivity of the deposit is increased to twenty five ohm-meters, the heating reach at six Hz is increased to about 100 meters and 350 meters, respectively, for the steel and the aluminum conductors. Similarly, the input impedance is increased to 0.13 and 0.03 ohms, respectively, for the steel and aluminum conductors. Much of the input impedance for the steel electrode is caused by the higher series resistance of the steel electrode. As such, a substantial fraction of the power applied to the steel electrode will be dissipated in just heating the electrode rather than in heating the deposit.
One of the difficulties noted earlier, in extending vertical well completion methods to horizontal applications, is that in a vertical well the casing is usually used as the return electrode. In the case of a horizontal completion, the electrode length could be comparable to the length of the usual return electrode, the well casing. Thus, the spreading resistance of the barren formations near the casing would dissipate about as much power as the deposit formation near the horizontal electrode, thereby wasting power. One solution is for the return electrode(s) to become one of the electrode(s) in the horizontal borehole.
Another advantage of using symmetrical excitation, as described below for FIG. 4, is that, for a fixed-length heating zone, each electrode exhibits about twice as much spreading resistance as for the monopole arrangement usually used in vertical wells, where the length of the electrode in the reservoir is much smaller than the return current electrode, ordinarily the production casing. To realize this advantage in a horizontal bore, the geometry of the electrodes may be about the same and the voltage applied to one electrode should be of opposite polarity to that applied to the nearby electrodes. This can be simply done by not grounding the output terminals of the power source or of the transformer that supplies power to the wellhead. Thus, by using a symmetrical excitation arrangement the power is more effectively applied to the deposit, minimizing power losses which would otherwise be wasted in a barren formation. The power delivery efficiency is improved by increasing the spreading resistance presented to the power delivery system.
The configuration shown in FIGS. 3 and 4 utilizes an iterated electrode array rather than a grouping of dipoles. The reasons are that the geometry and heating patterns of the commonly used RF dipole configuration are not appropriate to overcome the difficulties noted earlier. For example, the spacing between electrodes for an RF dipole configuration is small and may lead to inefficient use of electrical energy. On the other hand, the spacing between electrodes of the iterated array is much larger. Such spacing is determined by reservoir responses to electrical heating such that "zones of influence" from different electrodes only overlap partially, as determined from reservoir studies. This results in the total space occupied by all the electrodes in a horizontal borehole being typically less than fifty percent of the total length of that horizontal borehole. In addition, the heating patterns implied by the far-field radiation patterns of dipole arrays are only applicable if the media is dry. On the other hand, the media in a heavy oil deposit is usually moist and the heating pattern is controlled by the near fields rather than by the far or radiated fields.
FIG. 3 illustrates a well 30 that has been deviated to form a horizontal borehole. For illustrative purposes, longitudinal dimensions have been greatly foreshortened. In addition, the diameters of the casing and screen as illustrated may be different, depending on the depth of the well and the method of installing the screen/electrode assembly. Also, the lengths of the electrodes and FRP screen isolation sections are chosen for easy illustration; they may be significantly different for an actual installation.
The well 30, FIG. 3, is installed by first drilling a vertical borehole from the earth surface 32 through at least some of the overburden 33. The boring is deviated, in a deeper portion of the well 30, to form the generally horizontal section 37 of the borehole.
The radius of the deviation section 39 from the vertical portion of well 30 to its "horizontal" borehole 37 may be in the order of forty meters or even more (e.g., one hundred meters). The horizontal borehole 37 lies in an oil reservoir 34, between the overburden 33 and the underburden 35. After the boring tool is removed, a screen/electrode assembly 38 attached to a casing string 39 is lowered through the vertical borehole to be inserted into the horizontal borehole 37.
The upper part of the well 30, in the overburden 33, may be identical to the upper portion of the vertical, monopole-type well in FIG. 1 of U.S. Pat. No. 5,070,533 except that the cable 40, the feed-through connector 41, and the cable 42 to the power supply (not shown) have two conductors. These conductors are insulated one from the other and are supplied with power from an ungrounded two terminal source (or from two terminals of a three terminal source) where one terminal is positive phased with respect to ground and the other terminal is negative phased. Cable 40 within the well 30 may also have a metallic armor. The upper parts of the well 30 include a surface casing 44, a flow line 45 connection to a product gathering system (not shown), a wellhead chamber 46, a pump rod lubricator or bushing 47, a pump rod 48, a production tubing 49, a pump 50, and a tubing anchor 51. The pump 50 may be located below the liquid level 59 at any depth.
The casing string in well 30 is grouted as at 52, down to and beyond the packer/hanger 53 that attaches the upper casing to the more horizontal portions of the casing, blank spacers 54, and a screen/electrode assembly 38. The outermost portions of the screen/electrode assembly 38 in the horizontal borehole 37 includes the blank steel spacer section 54, fiber reinforced plastic (FRP) or other electrical insulator pipe sections 55A, 55B and 55C, a positive electrode 56A and a negative electrode 56B. These electrodes are formed from sections of steel pipe. The polarity designates the positive or negative phased A.C. terminals or connections. Direct current is not used. Both the FRP pipe sections and the electrodes are usually perforated or slotted to admit oil into the interior of the well; the well grouting is ordinarily porous enough for this purpose.
In the vertical portion of well 30 the insulated cable 40 is guided through two or more centralizers 60A and 60B that are perforated (perforations not illustrated) to permit liquid flow, and eventually extends through another centralizer 60C. The cable 40 is terminated in a connector assembly 61 that is attached to a dual-wire-cable-to-single-wire-cable plastic distributor block 62, which is also perforated for oil flow. A connector 63 connects one cable conductor to the single conductor in an insulated cable 64A. The conductor in cable 64A is connected to a "T" connector 65 that provides a connection 65A to electrode 56A. The other conductor from assembly 61 is connected, by a connector 66, to the conductor in a cable 64B that is similar in construction to cable 64A. The "T" connector 65 may also house a simple switch that will disconnect electrode 56A from the conductor in cable 64A if the temperature of electrode 56A becomes too high. Components 66, 64B, 68 and 68A provide similar functions, with electrode 56B connected to the wire in cable 64B by a connection 68A from "T" connector 68. Connections 65A and 68A are insulated as shown for the "T" connectors 74 and 77 in FIG. 4.
The deposit around the screen/electrode assembly 38 of FIG. 3 is heated by applying A.C. voltage to the two conductors of cable 42 at the surface 32. This causes A.C. current to flow through the down-hole cable 40 and thence to the conductors 64A and 64B in the screen/electrode assembly 38 in horizontal borehole 37. This applies an A.C. voltage between electrodes 56A and 56B, thereby causing current to flow through the reservoir liquids that fill the void between the horizontal borehole and the screen/electrode assembly 38 and the portions of the reservoir 34 that are adjacent to the electrodes. One advantage of the arrangement shown in FIG. 3 is that the return current electrode(s) (e.g., 56A or 56B) are in the deposit and no power or heat is wasted in adjacent barren formations, as might be the case if vertical well technology were routinely applied in the horizontal well 30.
FIG. 4 illustrates in more detail the iterated electrode construction of the invention. In this example, cylindrical, perforated electrodes 72 and 73 of about two meters length are positioned at ten meter intervals along the horizontal bore. The perforations in electrodes 72 and 73, and in other components illustrated in FIG. 4, have not been shown; they allow oil to enter the well casing. The electrodes 72 and 73 are spaced from each other by means of a perforated or slotted fiber-reinforced plastic pipe (casing) 75. By applying oppositely polarized potentials between adjacent electrodes, currents are injected into the reservoir that will heat the formations near the electrodes. The positively phased electrodes 72 are each connected to the positively phased conductor in the insulated cable 70 via the conductors 76 in a series of insulated "T" connectors 74. The negatively phased electrodes 73 are each connected to the negatively phased conductor in an insulated cable 71 via the conductors 78 in a series of insulated "T" connectors 77. Each electrode 72, 73 has an axial length of two meters; the inter-electrode spacing is ten meters.
FIG. 5 shows a cross section of the screen/electrode assembly taken approximately along line 5--5 in FIG. 4. FIG. 5 includes some of the perforations or slots 75A that are needed to permit fluids to enter the electrodes and their support, the FRP casing or pipe 75; perforations 75A are small enough to prevent sand particles from entering with the oil. The conductor 79 in cable 70 is covered with insulating material and provides a conductive connection between the insulated cable 70 and the electrode 72.
As discussed above and illustrated in FIG. 1, doubling the length of a horizontally completed well in a homogeneous reservoir does not double the production rate. On the other hand, doubling the length of the electrode in a horizontal electrically heated well doubles the power requirements, but also may not provide an increase in the oil flow rate proportionate to the increase in power.
The much increased surface-to-volume ratio of the heated formations near a long uninterrupted horizontal electrode is another cause for inefficiency. Such an increase will greatly augment the thermal diffusion losses to adjacent formations in comparison with those experienced in vertical wells. The low power injected per meter along an uninterrupted horizontal electrode also makes it difficult to increase the temperature of the formations adjacent a long horizontal electrode to a temperature high enough to significantly reduce the viscosity.
To address these difficulties, it is more effective to use a series of small (short) electrodes that are widely spaced along the horizontal screen, as illustrated in FIG. 4. Each of the heated volumes near each electrode then has a surface-to-volume ratio and heating rates similar to those experienced for vertical well heating electrodes, thereby suppressing excessive heat losses due to thermal diffusion. If properly done, such would reduce the power requirements as well as increase the input resistance and reduce the thermal diffusion losses.
FIG. 6 provides some insight as to the size and spacing of the iterated electrodes of this invention. In FIG. 6 the pressure difference between the shut-in reservoir pressure and the pressure in the well near the perforations is shown as a function of the radial distance from the well. Curve 93 is with and curve 94 is without electrical stimulation. The reservoir parameters used are representative of those found for a vertical electrically heated well in a heavy oil reservoir in Canada. Note that the electrical heating from this one well significantly reduces the flowing reservoir pressure out to a distance of about 4.5 to 6 meters (15 to 20 feet).
This suggests that short horizontal electrodes (three meters length) need not be spaced closer than ten meters (30 feet) apart. Using the data from FIG. 6, FIG. 7 was developed. FIG. 7 plots the pressure drop (as previously defined for FIG. 6) against the distance along an iterated horizontal bore completion. This drop was estimated using a ten meter spacing between three meter electrodes at spacings 111, 112 and 113. This was done by taking curve 92 of FIG. 6 and plotting it symmetrically with respect to each of the center points of the three electrodes. These plots are shown in curves 103, 104 and 105. The composite pressure drop is shown by curve 107; curve 107 is developed by combining the pressure drops from curves 103-105. Note that in the overlap regions between electrodes the pressure drop is reduced substantially, such that at points 108A and 108B the pressure drop found for just one of the two adjacent electrodes is reduced by a factor of about two. These effects almost simulate the pressure drop effect of a continuously slotted horizontal electrode, but the iterated arrangement does not have the disadvantages of a continuous electrode.
TABLE 2______________________________________Design Example, Horizontal Bore Iterated Electrodes,Connected in Pairs, All Pairs in Parallel______________________________________Power Supply:Rating 400 KwLoad resistance (minimum) 1.7 ohmsMaximum current 480 ampsOperating frequency 6 Hz (or higher)Reservoir:Thickness (height) 4 metersResistivity 25 ohm-metersHorizontal bore length 300 metersUnstimulated production rate 300-500 bbl/dayIterated Electrodes:Length 2 metersDiameter 0.2 metersSpacing between paired electrodes 6 metersSpacing between electrode pairs 30 metersTotal number of electrode pairs 10Spreading resistance per electrode 8.7 ohmsSpreading resistance, total 1.7 ohmsPower dissipation/pair 40 Kw______________________________________
Table 2 presents a "first-cut" design example for an iterated electrode in a horizontal well. The purpose is to demonstrate, using plausible values, that practical and economically attractive configurations of the iterated electrode line are possible. This assumes a configuration such as those illustrated in FIGS. 3 and 4. The other assumptions are noted in Table 2. The power delivery requirement of 400 Kw over a frequency range of three Hz to no more than 3000 Hz was considered to be practical. A maximum current in the range of 500 to 650 Amperes into a 1.7 ohm load resistance is within the state of the art for existing power conditioning units that have been successfully field tested. The required current carrying capacity of 480 amperes is within a factor of two or less of the published rating for the total current carrying capability of the larger diameter downhole pump motor cables. The reservoir parameters are plausible for a Canadian heavy oil deposit with a 300 meter horizontal completion.
The parameters chosen for the iterated electrode array were chosen for illustrative purposes. The spreading resistance of each electrode as an isolated element in a homogeneous medium was developed as follows: Spreading Resistance={(resistivity)/(2πL)}1n{2L/a-1}, where "L" is the length of the electrode and "a" is its radius. This value was calculated to be about 8.7 ohms; each of the pairs would exhibit twice that resistance, or 17.4 ohms. Ten pairs of these electrodes in parallel would have a resistance of about 1.7 ohms. Such a high load resistance permits high power delivery efficiencies both within the casing and within the horizontal screen.
The wellhead power per electrode pair is 40 Kw or about 30 Kw per electrode pair in the deposit assuming reasonable values for delivery efficiencies and thermal diffusion losses. Ideally, 40 Kw of electrical stimulation, at the wellhead, per pair of electrodes should stimulate production of low water content oil by about 100 to 150 bbl/day per pair. The overall production increase would be from 300 to 500 bbl/day to 1000 to 1500 bbl/day.
The average power dissipation per meter of electrode length is 10 kW per meter, referencing the wellhead input. This is sufficient to provide about 240 kWh per day per meter of electrode. At 8 kWh of power at the wellhead per barrel of oil produced, this results in a stimulated production of up to thirty barrels/day per meter of electrode length and up to 1200 bbl/day overall. The effectiveness of the electrical stimulation is progressively reduced as the heating rate per meter of electrode length is reduced. Very slow heating rates allow substantial thermal diffusion to occur, even if the heating zone is quite compact. This reduces the effectiveness of the electrical stimulation. The lower limit for the heating rate is controlled by the thermal diffusion properties of the formation, the oil-to-water ratio, and the amount of ingressing liquids per meter length. A lower limit of 1.5 kW per meter can be used as the lower bound for the average power dissipated per meter of electrode for high resistivity deposits and low production overall production rates. Higher power dissipation per meter of electrode length is preferred, in the order of 3 kw per meter and higher.
The lower limit on the value of resistance (impedance) presented to the power delivery system should be at least twice the value of the series resistance of the power delivery system that appears at the feed point to the interated array, such as at the connector 61 in FIG. 3. If the power is delivered via cable, the series impedance of conventional power cables that deliver power to downhole pumps would be no less than 0.3 ohms per 1000 meter length. They would require the resistance presented by the array to be at least 0.6 ohms to realize a 67% power delivery efficiency.
The lowest limit on the resistance presented to the power delivery system can be estimated based on the assumption that an idealized downhole transformer is used to terminate a conventional power delivery cable and that the series impedance of the power cable and transformer is negligible. In this case the lower limit on the load impedance will be determined by the current carrying capacity of the insulated conductors used within the screen to carry the current to the electrodes in the array. The largest size metallic conductor would not exceed one inch (2.54 cm) in diameter, excluding insulation. Assuming a power dissipation limit along the conductor of about 80 to 100 watts per meter length of a one inch diameter copper conductor, the maximum continuous load current would be about 1400 amperes. To deliver 400 kW at 1400 amperes requires a load resistance no smaller than 0.2 ohms.
While the foregoing techniques have been described in the context of a long horizontal completion, there are some vertical well installations that may require the use of an iterated electrode design. Such a well typically would exhibit high unstimulated flow rates and lengths in excess of ten meters. The spacing of the electrodes would also be governed according to the vertical resistivity profile wherein the electrodes would be placed in regions of high resistivity and fluid permeability. Regions of low resistivity would be avoided as well as regions of low oil saturation and/or fluid permeability.
In the case of horizontal wells, the assumption that the deposit is precisely horizontally layered may not apply. Therefore, the electrode emplacement considerations just noted for a vertical well would also apply for a quasi-horizontal well; in this specification and in the appended claims, the term "horizontal" should be recognized as including quasi-horizontal well completions. | An electrical heating system for enhancing production from an oil well, particularly an oil well of the kind commonly known as a horizontal well, the well including an initial well bore extending downwardly from the surface of the earth through one or more overburden formations and communicating with a producing well bore extending from the initial well bore into at least one oil producing formation. The producing well bore may or may not be truly horizontal The heating system includes an electrode array comprising a plurality of at least three tubular, electrically conductive heating electrodes extending through the producing well bore. Each electrode has a given length, usually two to three meters, and a smaller diameter D. The sum of the electrode lengths is substantially less than the length of the producing well bore. The electrodes are spaced from each other by isolation sections; the length of an isolation section is much greater than the electrode diameter D. The heating system further includes an electrical power delivery apparatus for energizing the electrodes with A.C. power, but with a phase displacement of at least 90°. | 4 |
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] The present invention contains subject matter related to Japanese Patent Application JP 2004-188526 filed in the Japanese Patent Office on Jun. 25, 2004, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an imaging apparatus, method and program, for monitoring events occurring in a broad area, from a panorama image obtained by photographing the area while sequentially changing the photographing direction. The invention also relates to a recording medium and an imaging system.
[0004] 2. Description of the Related Art
[0005] In any electronic still camera hitherto used widely, the solid-state imaging element such as a CCD converts the light coming from an object through the lenses to an image signal. The image signal is recorded in a recording medium. The image signal can be reproduced from the recording medium. Most electronic still cameras have a monitor that can display any still picture recorded and selected. In the electronic still camera, the image signal supplied to the monitor represents one image of the object. The image displayed covers only a small area. From the image it is impossible to monitor events that are happening in a broad area.
[0006] In view of this, monitor cameras are used in increasing numbers. Each monitor camera photographs an object, while the photographing direction is sequentially changed, thus providing a plurality of images. The images are synthesized into a panorama image, from which the events occurring in a broad area can be monitored. Particularly in recent years, there has been proposed the technique of reducing and combining a plurality of video signals, thus generating a one-frame video signal (see, for example, Japanese Patent Application Laid-Open Publication No. 10-108163). An integrated monitor/recorder system has been proposed, in which images are collected from monitor video cameras and recorded in a recording medium such as video tape, thereby to monitor a broad area (see, for example, Japanese Patent Application Laid-Open Publication No. 2000-243062).
SUMMARY OF THE INVENTION
[0007] Assume a monitor camera is installed in an area which unauthorized persons are forbidden to enter. Then, it is most important for the camera to efficiently and reliably photograph any intruders.
[0008] To detect any changes in the monitored area, from the images recorded in a recording medium such as video tape, however, a watchman must carefully observe all images, each input every time the camera scans the area. He or she needs to find any change in the image, however small it is, or perceive any object that appears, however small it is. Tremendous labor and time are required. In addition, changes in the area may be overlooked because this system depends on the eyes of the watchman.
[0009] When the area is monitored at night, the watchman cannot help but try to find intruders, if any, from the dark images the camera has photographed. It is extremely difficult for him or her to detect intruders, particularly if the area being monitored is large.
[0010] The dark images photographed at night disable the watchman to determine in which building an intruder has entered the premises, or in which route the intruder has walked. The broader the area monitored, the more difficult it is to determine the behavior of the intruder.
[0011] The present invention has, been made in consideration of the foregoing. It is desirable to provide an imaging apparatus and an imaging method, which can monitor a broad area, day and night, to watch a specific object, such as a man, in connection with the background. It is also desirable to provide a program that enables computers to perform the method, a recording medium in which the program is recorded, and an imaging system storing the program.
[0012] According to the present invention, there is provided an imaging apparatus comprising:
an imaging means for photographing an area, while sequentially setting a photographing direction to unit images that constitute a panorama image of the entire area; a panorama-image generating means for generating a panorama image by combining a plurality of unit images obtained by the imaging means; a panorama-image storage/management means for storing and managing the panorama image generated by the panorama-image generating means; a thermography imaging means for photographing an object that has a temperature falling within a preset temperature range as a thermal image; a direction control means for sequentially shifting the photographing direction of the thermography imaging means within the area being photographed; a thermal-image generating means for combining a plurality of thermal images provided by the thermography imaging means, thereby to generate a panorama thermal image of the entire area; an image-synthesizing means for synthesizing the panorama image generated by the panorama-image generating means, with the panorama thermal image generated by the thermal-image generating means; and an image-displaying means for displaying the synthesized image generated by the image-synthesizing means.
[0021] According to the present invention, there is also provided an imaging method comprising the steps of:
photographing an area, while sequentially setting a photographing direction to unit images that constitute a panorama image of the entire area; generating a panorama image by combining a plurality of unit images obtained in the photographing step; storing and managing the panorama image generated in the panorama-image generating step; controlling a thermography imaging unit for photographing an object that has a temperature falling within a preset temperature range as a thermal image, while sequentially shifting the photographing direction of the thermography imaging unit within the area being photographed; generating a panorama thermal image of the entire area by combining a plurality of thermal images provided by the thermography imaging unit; synthesizing the panorama image generated in the panorama-image generating step, with the panorama thermal image generated in the thermal-image generating step; and displaying the synthesized image generated in the image-synthesizing step.
[0029] According to the present, invention, there is also provided a program for causing computers to perform the steps of:
photographing an area, while sequentially setting a photographing direction to unit images that constitute a panorama image of the entire area; generating a panorama image by combining a plurality of unit images obtained in the photographing step; storing and managing the panorama image generated in the panorama-image generating step; controlling a thermal camera in a thermography imaging unit that photographs an object having a temperature falling within a preset temperature range as a thermal image, while sequentially shifting the photographing direction of the thermography imaging unit within the area being photographed; generating a panorama thermal image of the entire area by combining a plurality of thermal images provided by the thermography imaging unit; synthesizing the panorama image generated in the panorama-image generating step, with the panorama thermal image generated in the thermal-image generating step; and displaying the synthesized image generated in the image-synthesizing step.
[0037] According to the present invention, there is also provided a recording medium storing a program for causing computers to perform the steps of:
photographing an area, while sequentially setting a photographing direction to unit images that constitute a panorama image of the entire area; generating a panorama image by combining a plurality of unit images obtained in the photographing step; storing and managing the panorama image generated in the panorama-image generating step; controlling a thermal camera in a thermography imaging unit that photographs an object having a temperature falling within a preset temperature range as a thermal image, while sequentially shifting the photographing direction of the thermography imaging unit within the area being photographed; generating a panorama thermal image of the entire area by combining a plurality of thermal images provided by the thermography imaging unit; synthesizing the panorama image generated in the panorama-image generating step, with the panorama thermal image generated in the thermal-image generating step; and displaying the synthesized image generated in the image-synthesizing step.
[0045] According to the present invention, there is also provided an imaging system comprising:
an imaging means; a thermography imaging means for photographing an object that has a temperature falling within a preset temperature range as a thermal image; a control apparatus including:
a panorama-image generating means for generating a panorama image of the entire area by combining a plurality of unit images obtained by the imaging means; a panorama-image storage/management means for storing and managing the panorama image generated by the panorama-image generating means; a direction control means for sequentially shifting the photographing direction of the thermography imaging means within the area being photographed; a thermal-image generating means for combining a plurality of thermal images provided by the thermography imaging means, thereby to generate a panorama thermal image of the entire area; and an image-synthesizing means for synthesizing the panorama image generated by the panorama-image generating means, with the panorama thermal image generated by the thermal-image generating means; and
at least one terminal device that is configured to access the control apparatus through a network, to acquire the synthesized image generated by the image-synthesizing means, by accessing the control apparatus, and to display the synthesized image acquired.
[0055] In the present invention, the thermography imaging unit that photographs an object existing in an area and having a temperature falling within a preset temperature range is sequentially shifted in terms of photographing direction. A plurality of thermal images provided by the thermography imaging unit are combined, forming a panorama thermal image. The panorama thermal image is synthesized with a panorama image provided by a visible-light camera, thereby forming a synthesized image. The synthesized image is displayed.
[0056] Hence, the invention enables a watchman to perceive the movement or change of any person in the area photographed, from the luminance distribution shown in the thermal image. Therefore, the watchman need not observe all images, each input every time the camera scans the area. His or her labor can be much reduced. In addition, the invention prevents the watchman from overlooking changes in the area. The invention therefore helps to achieve very reliable surveillance, because even a little movement of the person can be detected. In addition, the region in which the object exists can be identified, even at night, with the luminance distribution of the thermal image. Thus, the position of the region can be reliably determined in connection with the background, from the resultant synthesized image.
BRIEF DESCRIPTION OF THE DRAWINGS
[0057] FIG. 1 is a diagram showing a monitor system according to the present invention;
[0058] FIG. 2 is a block diagram illustrating the camera unit and the monitoring apparatus that are incorporated in the monitor system;
[0059] FIG. 3 is a diagram explaining how the camera unit photographs, at a view angle u, an area indicated by a black frame;
[0060] FIG. 4 is a diagram depicting an image displayed in the screen of a display;
[0061] FIG. 5 is a diagram showing a panorama thermal image displayed by a display; and
[0062] FIG. 6 is a diagram depicting a synthesized image displayed by a display.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0063] The preferred embodiment of the present invention will be described in detail, with reference to the accompanying drawings. As FIG. 1 shows, a monitor system 1 according to this invention comprises a camera unit 2 , a tracking imaging unit 81 , a thermal camera 82 , a monitoring apparatus 5 , a display 6 , a terminal device 9 , a terminal display 10 , and a network 8 . The camera unit 2 photographs an object, generating an image signal. The monitoring apparatus 5 receives an image signal from at least the camera unit 2 . The display 6 is connected to the monitoring apparatus 5 . The terminal device 9 is operated by users to execute application programs. The terminal display 10 is connected to the terminal device 9 . The network 8 achieves interactive communication between the camera unit 2 , monitoring apparatus 5 and terminal device 9 .
[0064] The camera unit 2 incorporated in the monitor system 1 comprises a pan-tilter section 3 and a camera section 4 that are formed integral with each other. The pan-tilter section 3 is a rotating base that can change the photographing direction around two axes, i.e., panning axis, and tiling axis.
[0065] The camera section 4 is held on the pan-tilter section 3 that is a rotating base. Controlled by the monitoring apparatus 5 , the camera section 4 photographs an object, while adjusting the photographing direction in the horizontal direction or vertical direction. When the camera section 4 is controlled by the monitoring apparatus 5 , it sequentially changes the photographing angle, photographing the object either magnified or reduced scale. Two or more camera sections 4 may be provided for the monitoring apparatus 5 . In this case, the same object can be photographed at different angles, providing image that represents images of the object, viewed from different angles.
[0066] The monitoring apparatus 5 is constituted by an electronic apparatus such as a personal computer (PC). The apparatus 5 records the image signal and the like that are transmitted from the camera unit 2 and tracking imaging unit 81 . The apparatus 5 supplies the recorded image signal and the like to the display 6 , which displays images to the user. The user may designate a desired part of the image displayed or a desired position in the image. Then, the monitoring apparatus 5 selects an optimal part of the image signal and causes the display 6 to display that part of the image, which the optimal part of the image signal represents. The monitoring apparatus 5 serves as main control apparatus, as well, to control the entire network 8 . Upon receiving requests from any other terminal devices 9 , the apparatus 5 transmits the image signal. The configuration of the monitoring apparatus 5 will be described later in detail.
[0067] The network 8 is, for example, the Internet in which the monitoring apparatus 5 is connected to the telephone line. Alternatively, it is a public communications network, such as integrated service digital network (ISDN) or broadband-ISDN (B-ISDN), either connected to TAs and modems that can achieve interactive communication of information. If the monitor system 1 is utilized in a small area, the network 8 may be a local area network (LAN). The network 8 may otherwise be a so-called optical-fiber communications network. Further, the network 8 may be designed to transmit NPEG-image data, in addition to still-picture data. If this is the case, the MPEG-image data is continuously transmitted via one channel and the still-picture data is transmitted via another channel at regular intervals, both in accordance with the Internet protocol (IP).
[0068] The terminal device 9 is a PC that the user uses at home or in the office, in order to acquire image from the monitoring apparatus 5 through the network 8 so that a desired process may be performed on the image. The terminal device 9 is connected to the network 8 , along with other terminal devices 9 . The users of these terminal devices 9 can therefore obtain any application program from the monitor system 1 at the same time. The terminal device 9 acquires video data from the monitoring apparatus 5 and supplies the data to the terminal display 10 . The terminal display 10 displays the image represented by the video data. When the terminal device 9 is operated by the user, it generates a request signal. The request signal is transmitted to the monitoring apparatus 5 . The structure of the terminal device 9 is not explained here; it can be understood from the description of the monitoring apparatus 5 .
[0069] The components of the monitor system 1 according to this invention will be described in detail, with reference to FIG. 2 .
[0070] As is illustrated in FIG. 2 , the camera unit 2 , tracking imaging unit 81 , thermal camera 82 and monitoring apparatus 5 are connected to a controller bus 21 .
[0071] The pan-tilter section 3 incorporated in the camera unit 2 has a tilt section 3 a and a pan section 3 b . The tilt section 3 a and the pan section 3 b cooperate to control the rotating base so that the photographing direction may be changed. The camera section 4 , i.e., another component of the camera unit 2 , comprises a lens section 22 , a lens control section 23 , an imaging section 24 , an IEEE (Institute of Electrical and Electronics Engineers) 1394 interface 25 , a GPS (Global Positioning System)-signal receiving section 28 , and a meta-data generating section 29 . The main function of the lens control section 23 is to change the angle of view of the lens section 22 . The imaging section 24 is arranged, extending at right angles to the optical axis of the lens section 22 . The IEEE1394 interface 25 transmits the image signal generated by the imaging section 24 , to an image input/output section 13 . The GPS-signal receiving section 28 is designed to determine the position that the camera unit 2 takes at present. The meta-data generating section 29 is coupled to the GPS-signal receiving section 28 . Note that the IEEE1394 interface 25 may be replaced by the Ethernet (trademark).
[0072] The monitoring apparatus 5 comprises a buffer memory 51 , an encoder 52 , a server 53 , an image-compressing section 54 , a graphic controller 55 , a CPU 56 , a memory card 61 , and a clock 62 . The buffer memory 51 is connected to the IEEE1394 interface 25 . The encoder 52 and server 53 are connected to the buffer memory 51 . The image-compressing section 54 compresses the image read from the server 53 . The graphic controller 55 is connected to the server 53 and image-compressing section 54 and generates image that is to be supplied to the display 6 . The CPU 56 supplies control signals via the control bus 21 , in order to control the other components of the monitoring apparatus 5 . The memory card 61 and the clock 62 are connected to an I/O port 58 .
[0073] The monitoring apparatus 5 further comprises a keyboard 59 and a mouse 60 . The user may operate the keyboard 59 and mouse 60 to designate a desired part of the image displayed by the display 6 or a desired position in the image.
[0074] The tilt section 3 a and the pan section 3 b drive the stepping motor in accordance with a drive signal supplied from the CPU 59 . Thus driven, the stepping motor rotates the rotating base. As a result, the photographing direction of the camera section 4 mounted on the rotating base is changed in the horizontal or vertical direction.
[0075] In accordance with a drive signal supplied from the CPU 56 , the lens control section 23 causes the lens section 22 to perform automatic diaphragm control and automatic focusing control. Based on the same drive signal, the lens control section 23 changes the angle of view with respect to the object that is to be photographed. Thus, the camera section 4 can photograph the object, while sequentially adjusting the photographing magnification.
[0076] The imaging section 24 is constituted by a solid-state imaging element such as a charge-coupled device (CCD). The lens section 22 focuses the image of the object on the imaging surface of the section 24 . The imaging section 24 performs photoelectric conversion on this image, generating an image signal. The image signal is transmitted to the IEEE 1394 interface 25 .
[0077] The GPS-signal receiving section 28 receives a signal from the GPS system. On the basis of this signal, the section 28 determines the position of the camera unit 2 and the photographing direction thereof. If two or more camera units 2 are installed, the GPS-signal receiving section 28 can make it possible to control the photographing directions of the respective camera units 2 . The signal output from the GPS-signal receiving section 28 is supplied to the meta-data generating section 29 . The meta-data generating section 29 generates position data items and meta-data. The position data items represent the latitude, longitude, orientation and altitude. The meta-data consists of parameter data items, e.g., time and other parameters. From the meta-data generating section 29 , the position data items and the meta-data are supplied to the encoder 52 . The GPS-signal receiving section 28 and the meta-data generating section 29 may not be used in the present invention.
[0078] The tracking imaging unit 81 and the thermal camera 82 are similar to the camera unit 2 and will not be described.
[0079] The thermal camera 82 is a camera that detects infrared rays emanating from, for example, a human body, thus accomplishing so-called thermography. That is, the camera 82 provides a thermal image that indicates the temperature distribution on the human body. The thermal camera 82 has a detector (not shown) that corresponds to the imaging section 24 . The detector detects the infrared rays emanating from the human body. The detector converts the intensity of infrared rays to an electric signal. The electric signal is amplified to a predetermined level. A so-called thermal image is thereby formed. Hereinafter, the signal representing the thermal image will be referred to as “thermal-image signal.”
[0080] The thermal camera 82 is configured to convert an image of any object the surface temperature of which falls within a preset range, into a thermal image. The temperature range may be set to, for example, temperature of the human body ±about 3° C. Then, the thermal camera 82 can detect exclusively the infrared rays coming from the human body. The user can set any desired temperature range in the thermal camera 82 , merely by operating a mouse 60 or the like, as will be explained later.
[0081] The buffer memory 51 temporarily stores the image signal or thermal-image signal supplied from the IEEE1394 interface 25 , in accordance with a control signal supplied from the CPU 56 . The image signal or thermal image signal, which is stored in the buffer memory 51 , is supplied to the encoder 52 . The encoder 52 compresses the data in accordance with, for example, the JPEG (Joint Photographic Experts Group) standards. The encoder 52 may add the position data or meta-data supplied from the meta-data generating section 29 , to the image signal or thermal image signal to be compressed and encoded. The encoder 52 outputs the image signal or thermal image signal, thus compressed and encoded, to the server 53 or the image-compressing section 54 . The process the encoder 52 performs can be dispensed with, if neither the image signal nor the thermal-image signal is compressed and encoded.
[0082] The server 53 records the image signal or thermal image signal output from the encoder 52 , in association with the position data and the meta-data. The sever 53 may be replaced by, for example, a hard disc or a disc-shaped recording medium that can be removed. The image signal recorded in the server 53 is read to the image-compressing section 54 or the graphic controller 55 , under the control of the CPU 56 . The image signal or thermal image signal recorded in the server 53 may be recorded in the memory card 61 . In this case, the user can transfer the image signal or thermal image signal to any other PC. Further, the image signal or thermal image signal recorded in the server 53 may be recorded in a network server (not shown). Then, the server 53 can be replaced by the network server.
[0083] The image-compressing section 54 generates compressed image data, or thumbnail image data, from the JPEG-type image signal read from the server 53 . Controlled by the CPU 56 , the image-compressing section 54 reads the image signal from the server 53 and generates a moving-picture data from the image signal read. The method that the image-compressing section 54 carries out to generate the moving-picture data is, for example, MPEG, Motion-JPEG, Motion-JPEG2000, or the like.
[0084] The graphic controller 55 processes the image signal or thermal image signal read from the server 53 , or the image signal or thermal image signal output from the image-compressing section 54 , so that the display 6 may display the image represented by the image signal or thermal image signal. Moreover, the graphic controller 55 controls the contrast and luminance in which the display 6 displays the image.
[0085] When the user operates the keyboard 59 or mouse 60 , designating a desired part of the image displayed or a desired position in the image, the CPU 56 transmits a drive signal or a control signal via the control bus 21 . The drive signal drives the pan-tilter section 3 or the lens control section 23 . The control signal controls the components of the monitoring apparatus 5 . Upon receiving a request signal from the terminal device 9 , the CPU 56 selects an optimal still-picture data item, moving-picture data item or information item, which are stored in the server 53 . The data item or information item selected is transmitted to the terminal device 9 .
[0086] How the monitor system 1 according to this invention operates will be explained below.
[0087] FIG. 3 is a diagram explaining how the camera unit 2 photographs, at a view angle u, an area indicated by a black frame. To photograph this area in its entirety at the view angle u, the photographing direction must be sequentially changed in the horizontal direction or vertical direction. Assume that the area to be photographed can be expressed as i×j times the size of a frame (hereinafter called “unit image”) obtained at a given photographing view angle u. Then, it is necessary to set at least i×j photographing directions. The i×j unit images, obtained by photographing the object at the view angle u, are combined to provide an image of the entire area.
[0088] The unit images constituting the image of the area photographed have coordinates (M, N) each. The X-axis ordinates of the unit images, 1 , 2 , . . . M, and i, are arranged from the left in the horizontal direction. The Y-axis ordinates of the unit images, 1 , 2 , . . . N, and j, are arranged from the top in the vertical direction. Thus, when the CPU 56 transmits a drive signal to the tilt section 3 a and pan section 3 b , the tilt section 3 a and the pan section 3 b change the photographing direction of the camera section 4 , first to the coordinates (1, 1) of the upper-left unit image. Then, the camera section 4 photographs the upper-left unit image, generating an image signal. The buffer memory 51 temporarily stores this image signal. The encoder 52 compresses and encodes the image signal in accordance with the JPEG standards. To the image signal thus processed, there are added the position data and the meta-data. Note that the position data is transmitted from the GPS-signal receiving section 28 and represents the photographing direction and the like. The resultant combination of the image signal, the position data and the meta-data is recorded in the server 53 .
[0089] The CPU 56 transmits another drive signal to the tilt section 3 a and pan section 3 b . Driven by this signal, the tilt section 3 a and pan section 3 b shift the photographing direction of the camera section 4 to the right by one frame, setting the direction to the coordinates (2, 1). Then, the camera section 4 photographs the unit image at the coordinates (2, 1), generating an image signal. This image signal is recorded in the server 53 , too. Controlled by the CPU 56 , the camera section 4 photographs the unit images at the coordinates (3, 1), the coordinates (4, 1), . . . the coordinates (i, 1), one after another, while the photographing direction is being shifted in the horizontal direction.
[0090] After the camera section 4 finishes photographing all unit images of the first row, the CPU 56 controls the pan-tilter section 3 , which sets the photographing direction at the first coordinates (1, 2) of the second row. The camera section 4 photographs the unit image at the coordinates (1, 2). Under the control of the CPU 56 , the camera unit 2 photographs the other unit image, one after another. When the unit 4 finishes photographing the last unit image at the coordinates (i, j), the image signals representing i×j unit images are recorded in the server 53 .
[0091] The image signals representing the unit images are sequentially read from the server 53 to the image-compressing section 54 . The section 54 compresses each input signal, generating a signal that represents an image much smaller than the screen of the display 6 . Each unit image thus compressed is supplied via the graphic controller 15 to the display 6 . The display 6 displays all i×j unit images, represented by the image signals stored in the server 53 . The i×j unit images, thus displayed, constitute a panoramic entire image (panorama image). Namely, an entire image showing the latest state of the area photographed is obtained as the camera unit 2 performs the above-mentioned photographing at regular intervals. The data that represents the panorama image can be stored and managed in the server 53 .
[0092] FIG. 4 depicts an entire image constituted by i×j unit images and displayed in the entire-image displaying section 70 of the display 6 . The monitoring apparatus 5 may cause the entire-image displaying section 70 to display the unit images constituting entire image, along with the borders between the unit images, or display only the entire image that is, so to speak, seamless. Further, the apparatus 5 may cause the entire-image displaying section 70 to display an image of the entire area, photographed at a specific angle of view, instead of the panoramic whole image of the area.
[0093] A screen 45 has a magnified image displaying section 71 . In the magnified image displaying section 71 , any unit image constituting the entire image displayed in the entire-image displaying section 70 designated by the user can be displayed in a magnified form. Alternatively, a moving picture photographed in the photographing direction of a unit image may be displayed in the magnified image displaying section 71 . Seeing the moving picture, the user can recognize, in real time, the direction in which the designated unit image has been photographed.
[0094] The user can designate a desired part of the image displayed in the entire-image displaying section 79 or the magnified image displaying section 71 , or a desired position in the image, by operating the keyboard 59 or the mouse 60 . In the image displaying sections 70 and 71 , a reference line or a pointer may be displayed, which the user can move by operating the mouse 60 or the like, in order to designate the desired part of the image or the desired position in the image.
[0095] Keys 72 , 73 , 75 and 76 are displayed in the screen 45 . The user may select these keys, instead of operating the mouse 60 . If the keys are selected, the magnification for any unit image displayed in the magnified image displaying section 71 will be increased or decreased, the photographing direction of the camera section 4 will be adjusted in the horizontal and vertical directions, and various operating modes will be set.
[0096] The thermal camera 82 may be operated in the same way as the camera unit 2 is. Then, the thermal camera 82 can provide a panoramic thermal image of the area that is to be monitored. Hereinafter, the panoramic thermal image will be referred to as “panorama thermal image.”
[0097] FIG. 5 shows a panorama thermal image displayed in the entire-image displaying section 70 . If the temperatures that the thermal camera 82 should detect is temperature of the human body ± about 3° C., the thermal image of any region in which a man exists will be displayed as a luminance distribution. As a result, a panorama thermal image constituted by combining thermal images of such regions is displayed as a luminance image, as is illustrated in FIG. 5 . The regions other than these are not be displayed at all.
[0098] The unit images constituting the panorama thermal image have a size that depends on the photographing angle of the thermal camera 82 . Nonetheless, they need not be of the same size as the unit images obtained by the camera unit 2 .
[0099] The user may designate any region in which a man exists. Then, the image of this region can be magnified and displayed in the magnified image displaying section 71 . The body temperature distribution in the man or men can be recognized in detail from the luminance distribution displayed in the magnified image displaying section 71 .
[0100] In the monitor system 1 according to the present invention, a panorama thermal image may be synthesized with the entire image, forming a synthesized image. The entire-image displaying section 70 may display the synthesized image, as is illustrated in FIG. 6 . Seeing the synthesized image displayed in the entire-image displaying section 70 , the user can easily recognize any region detected as a thermal image, in which a man exists, in connection with the entire image.
[0101] Thus, the present invention enables the watchman to perceive the movement or change of any person in the area photographed, from the luminance distribution shown in the thermal image. Therefore, the watchman need not observe all images, each input every time the camera scans the area. His or her labor can be much reduced. In addition, the invention prevents the watchman from overlooking changes in the area. The invention therefore helps to achieve very reliable surveillance.
[0102] If the monitor system 1 is used to perform surveillance at night, the camera unit 2 provides dark entire images only, from which the movement of any person cannot be perceived. Nevertheless, any region in which a man exists can be identified with a specific luminance distribution in any thermal image obtained from the thermal camera 82 that detects the infrared rays emanating from any human body. To determine the position that said region assumes in the area monitored, the dark panorama thermal image obtained at night is synthesized with the entire image obtained in daytime and stored in the server 53 . From the resultant synthesized image, the user can correctly determine the position of the man or men identified with the specific luminance distribution, in connection with the background. Hence, the monitor system 1 , if installed in an area which unauthorized persons are forbidden to enter, enables the user to recognize, the route along which an intruder is walking in the area, even at night.
[0103] In the monitor system 1 , the photographing directions of the camera unit 2 and thermal camera 82 are shifted, thereby providing unit images, and the unit images are combined, forming a panorama image. The monitor system 1 is therefore useful, particularly when a broad area is monitored for any intruders.
[0104] If a man touches an object such as a wall, heat will be conducted from the hand to the wall, and the touched part of the wall will be displayed as a specific luminance distribution. In this case, the range of temperature detection for the thermal camera 82 is set to an optimal one. Then, the luminance distribution in said touched part to which heat is conducted from the man is discarded so that the thermal image can be generated that show the movement of a man or men only.
[0105] In the monitor system 1 according to this invention, the entire-image displaying section 70 displays a synthesized image. The user may click the mouse 60 , selecting that part of the synthesized image which has a specific luminance distribution. Then, the tracking imaging unit 81 photographs that part of the area which corresponds to said part of the synthesized image.
[0106] If the tracking imaging unit 81 is used, the relative position on the manorama thermal image that the part of the specific luminance distribution takes in the thermal image is detected, and the photographing direction of the tracking imaging unit 81 is then automatically set to the relative position detected.
[0107] To make the tracking imaging unit 81 track a specific object such as a man, panorama thermal images are taken at predetermined intervals, and the luminance difference between two panorama thermal images, one preceding the other, and both obtained in the same photographing direction. The relative position of the image region in which a man is displayed at present is thereby recognized. Then, the photographing direction of the tracking imaging unit 81 is set to that relative position of the image region. The sequence of these operations is repeated, thus obtaining the latest images that indicates the movement of the specific object.
[0108] The tracking imaging unit 81 may be a camera, such as a snooper scope, which can provide dark-field images. If the watchman recognizes a specific object, such as a human intruder, from the thermal image obtained at night, the tracking imaging unit 81 tracks this object. Thus, the tracking imaging unit 81 keeps photographing the object as it moves, providing images of the specific object in real time even at night.
[0109] Moreover, the data representing synthesized images is stored in the server 53 in the monitor system 1 . The user of the terminal device 9 , who has accessed the monitoring apparatus 5 via the network 8 , can observe any synthesized image on the terminal display 10 that is connected to the terminal device 9 . If a plurality of terminal devices 9 are connected to the apparatus 5 via the network 8 , many users can see the synthesized image at the same time. Further, the data items representing synthesized images, respectively, may be sequentially stored in the server 53 as they are generated. In this case, the user of any terminal device 9 can examine the synthesized images in detail, one by one retroactively.
[0110] It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof. | The present invention provides an imaging apparatus that monitors a broad area, day and night, to watch a specific object, such as a man, in connection with the background. The imaging apparatus includes a camera unit, a panorama-image generating section generating a panorama image of the entire area by combining a plurality of unit images obtained by the camera unit, a panorama-image storage/management section storing and managing the panorama image generated by the panorama-image generating section, a thermal camera photographing an object that has a temperature falling within a preset temperature range as a thermal image, a direction controller sequentially shifting the photographing direction of the thermal camera within the area being photographed, a thermal-image generating section combining a plurality of thermal images provided by the thermal camera, thereby to generate a panorama thermal image of the entire area, an image-synthesizing section synthesizing the panorama image generated by the panorama-image generating section, with the panorama thermal image generated by the thermal-image generating section, a display displaying the synthesized image generated by the image-synthesizing section. | 7 |
BACKGROUND INFORMATION
[0001] A device for injecting fuel having at least one fuel injector is described in German Patent Application No. DE 100 50 599. This fuel injector is provided with an intensifier piston, which intensifies the pressure of the liquid supplied to the fuel injector from a rail pressure to a higher pressure by hydraulic transmission. The disadvantage is that this type of pressure intensification is very expensive and complicated.
[0002] It is also known to connect two feed pumps one behind the other in series in order to attain a predetermined pressure in a fuel line and in the fuel injector that is flow-connected to the fuel line. Since the pressure increase produced by the second feed pump is not needed in every operating state, this solution is very expensive.
SUMMARY OF THE INVENTION
[0003] The device according to the present invention for injecting fuel has the advantage over the related art that the pressure intensification in the fuel injector is simpler and more economical in that an electromagnetic pressure intensifier is situated on at least one fuel injector.
[0004] It is particularly advantageous that the electromagnetic pressure intensifier is connected immediately upstream from the at least one fuel injector. In this way only a very small volume needs to be brought to a higher pressure, so that little energy is expended to increase the pressure and the pressure increase is attainable in a very short time.
[0005] According to a preferred exemplary embodiment, the electromagnetic pressure intensifier is plugged, clipped, welded, or pressed onto an input channel of the fuel injector. These connections are particularly simple and inexpensive. The electromagnetic pressure intensifier is flow-connected to a fuel line.
[0006] It is also advantageous to use an electromagnetic, piezoelectric, or magnetostrictive fuel injector as the fuel injector.
[0007] In addition, it is advantageous if the electromagnetic pressure intensifier has an electromagnet with an exciter coil and an armature, the armature being operatively connected to a piston which is positioned so that it is axially movable in a pressure chamber of the electromagnetic pressure intensifier, since a pressure intensifier of this sort is of particularly simple construction and may be produced very cost-effectively.
[0008] Additionally advantageous is that the electromagnetic pressure intensifier has an inlet channel that opens into the pressure chamber through an intake port, and that the pressure chamber has an outlet that is flow-connected to an inlet channel of the fuel injector.
[0009] It is also advantageous if the flow connection from the inlet channel to the pressure channel is closable and a pressure increase in the pressure chamber and downstream from the outlet of the pressure chamber is achievable via an axial stroke of the piston.
[0010] A preferred embodiment provides for the flow connection from the inlet channel to the pressure chamber to be closed via a separate valve in the inlet channel, via the piston, or via an interaction of the piston with the armature, followed by attainment of a brief pressure intensification via a stroke of the piston.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows a view of a fuel injector having an electromagnetic pressure intensifier.
[0012] FIG. 2 shows a first exemplary embodiment.
[0013] FIG. 3 shows a second exemplary embodiment of the electromagnetic pressure intensifier.
DETAILED DESCRIPTION
[0014] FIG. 1 shows a fuel injector having an electromagnetic pressure intensifier.
[0015] The device according to the present invention has at least one fuel injector 1 , which in the case of direct injection, for example, injects fuel into a combustion chamber of a combustion engine, and in the case of manifold injection injects fuel into a so-called intake manifold of a combustion engine. The at least one fuel injector 1 is flow-connected to a fuel line 2 , for example a fuel rail, through which the at least one fuel injector 1 is supplied with fuel. Fuel injector 1 is designed for example as an electromagnetic, piezoelectric, or magnetostrictive valve, but may explicitly be executed in any way desired.
[0016] A feed unit 3 is provided which is designed for example as a dynamic pump and conveys fuel from a reservoir 4 under elevated pressure into fuel line 2 .
[0017] In order to fulfill the increasingly stringent emission standards, the emissions of an internal combustion engine in a so-called cold start must be reduced. This is accomplished in the related art by increasing the pressure in fuel line 2 , so that the spray produced by fuel injector 1 has a smaller mean droplet size. The requisite pressure increase in fuel line 2 is so high, however, that it cannot be attained by provided feed unit 3 . In the related art an additional second feed unit is therefore connected downstream from feed unit 3 ; it is designed, for example, as a dynamic pump, and increases the pressure in the fuel line to the necessary level, or a higher-performance, more expensive feed unit is utilized.
[0018] To eliminate the costs of this second, more expensive, feed unit, the present invention provides for an electromagnetic pressure intensifier 5 to be situated on the at least one fuel injector 1 to increase the pressure. For example, at least one pressure intensifier 5 is provided on each fuel injector 1 .
[0019] The at least one electromagnetic pressure intensifier 5 is connected directly upstream from the at least one fuel injector 1 , and for example is plugged, clipped, pressed, or welded or the like onto an input channel 8 of fuel injector 1 . In this way, electromagnetic pressure intensifier 5 is firmly connected to fuel injector 1 and situated directly on the latter.
[0020] According to the present invention, the pressure of the fuel is not increased already in fuel line 2 , as in the related art, but just shortly before and/or in fuel injector 1 , via electromagnetic pressure intensifier 5 . The volume within fuel injector 1 is a great deal smaller than the volume of fuel line 2 from reservoir 4 to fuel injector 1 , so that significantly less energy is required to increase the pressure. In addition, the pressure increase is attained faster in injector 1 through the electromagnetic pressure intensifier 5 than through a feed unit 3 situated in fuel line 2 , at a greater distance from fuel injector 1 in terms of the flow connection.
[0021] FIG. 2 shows a first exemplary embodiment of the electromagnetic pressure intensifier.
[0022] In the case of the electromagnetic pressure intensifier according to FIG. 2 , the parts that remain the same or work the same as in the device according to FIG. 1 are identified by the same reference numerals.
[0023] For example, electromagnetic pressure intensifier 5 is a re-engineered electromagnetic fuel injector which is executed, for example, as described below. Electromagnetic pressure intensifier 5 has a housing 9 in which an electromagnet 7 having an exciter coil 10 and an axially movable armature 11 is situated. A pressure chamber 14 , in which a piston 15 actuated by electromagnet 7 is situated so that it is axially movable with respect to an axis 12 , is provided in housing 9 . Armature 11 , piston 15 , and/or exciter coil 10 are situated, for example, centered with respect to axis 12 . Over part of its axial length, armature 11 is surrounded ring-like by exciter coil 10 , which is situated in an induction cup 13 . An inlet channel 16 opens via an intake port 17 into pressure chamber 14 of pressure intensifier 5 , for example on the periphery of pressure chamber 14 . Inlet channel 16 is flow-connected upstream to fuel line 2 . Pressure chamber 14 of electromagnetic pressure intensifier 5 is flow-connected to fuel injector 1 via an outlet 18 .
[0024] Piston 15 of electromagnetic pressure intensifier 5 is mechanically coupled with armature 11 and connected to it. Piston 15 is moved by means of a return spring 21 into a first position, in which piston 15 bears against a stop 22 for example, and in which intake port 17 opens into pressure chamber 14 . When no current is flowing through exciter coil 10 , piston 15 is in this first position, thus enabling a dry-running operation.
[0025] If current is applied to exciter coil 10 , armature 11 executes an axial stroke with piston 15 , for example in the direction of fuel injector 1 . According to the first exemplary embodiment, after a first partial stroke, piston 15 covers intake port 17 , thereby closing the flow connection with inlet channel 16 . Intake port 17 may also be closed in any other way desired, for example, by a separate valve in inlet channel 16 . After intake port 17 is closed, the remaining partial stroke of piston 15 produces a pressure increase in pressure chamber 14 and in the part of fuel injector 1 that is flow-connected to outlet 18 of electromagnetic pressure intensifier 5 , since fuel injector 1 is closed at this time and piston 15 is therefore operating on a closed volume of liquid. In this way, pressure intensifier 5 produces a pressure increase in the fuel shortly before the opening of fuel injector 1 . When fuel injector 1 opens after a predefined pressure increase has been reached, at least part of the fuel whose pressure has been increased by electromagnetic pressure intensifier 5 is injected into the combustion chamber or into the intake manifold of the internal combustion engine. The predefined pressure increase is dependent on the particular operating state of the internal combustion engine, and is calculated in each case from parameters of the engine controller in order to open the fuel injector at an optimal point in time.
[0026] For example, housing 9 has an air flow hole 30 in the area of coil 10 in order to ensure pressure equalization.
[0027] After or shortly before or simultaneous with the closing of fuel injector 1 , exciter coil 10 is de-energized, so that piston 15 of electromagnetic pressure intensifier 5 is moved by the force effect of return spring 21 on piston 15 from a second position back to the first position. Since intake port 17 is again open in the first position, liquid flows from inlet channel 16 into pressure chamber 14 and into fuel injector 1 downstream from outlet 18 of electromagnetic pressure intensifier 5 , replacing the quantity of fuel injected in the last injection.
[0028] FIG. 3 shows a second exemplary embodiment of the electromagnetic pressure intensifier.
[0029] In the case of the electromagnetic pressure intensifier according to FIG. 3 , the parts that remain the same or work the same as in the device according to FIG. 1 and in the electromagnetic pressure intensifier according to FIG. 2 are identified by the same reference numerals.
[0030] The second exemplary embodiment of the electromagnetic pressure intensifier differs from the first exemplary embodiment in that inlet channel 16 is closed not by piston 15 , but by an interaction of armature 11 with piston 15 , and that an antechamber 23 is provided between coil 10 and pressure chamber 14 when viewed in the axial direction. Inlet channel 16 does not open into pressure chamber 14 , as in the first exemplary embodiment, but rather into antechamber 23 . Armature 11 and piston 15 are not connected to each other in a single piece in the second exemplary embodiment, but are executed as separate parts which are situated in such a way that they are at least partially movable relative to each other in the axial direction.
[0031] In antechamber 23 a first return spring 21 . 1 is provided, which has one of its ends braced against piston 15 and acts on armature 11 with its other end to return it to its position. A second return spring 21 . 2 , which has one of its ends braced against housing 9 and acts on piston 15 with its other end to return it to its position, is provided in pressure chamber 14 . First return spring 21 . 1 is softer than second return spring 21 . 2 .
[0032] For example, inlet channel 16 is partially formed in armature 11 , and leads centrally with regard to axis 12 into antechamber 23 via at least one intake port 17 provided on armature 11 . Intake port 17 may also be provided on the periphery of antechamber 23 , however, and inlet channel 16 may not be provided in armature 11 , but separately or on housing 9 .
[0033] Armature 11 , piston 15 , and/or coil 10 are situated, for example, centered with respect to axis 12 . Armature 11 has a closing section 24 on its end facing piston 15 , which is spherically shaped, for example. Antechamber 23 is connected to pressure chamber 14 via a connecting orifice 25 . Piston 15 has a pressure chamber inlet 28 , which is situated centered with regard to axis 12 and has on its end facing antechamber 23 a , for example, spherical valve seat 29 . Valve seat 29 of piston 15 cooperates with closing section 24 of armature 11 after a predefined axial stroke of armature 11 , and opens or closes the flow connection between antechamber 23 and pressure chamber 14 .
[0034] When no current is flowing through exciter coil 10 , piston 15 is in the first position against stop 22 , with armature 11 and piston 15 spaced at a distance from each other axially. As a result, when no current is flowing through exciter coil 10 there is a flow connection from antechamber 23 via connecting orifice 25 and pressure chamber inlet 28 of piston 15 into pressure chamber 14 , which is used to fill pressure chamber 14 and fuel injector 1 .
[0035] If current is applied to exciter coil 10 , only armature 11 first executes an axial stroke, for example in the direction of fuel injector 1 . After a first partial stroke of armature 11 , armature 11 strikes valve seat 29 of piston 15 with its closing section 24 , and in this way closes pressure chamber inlet 28 . After a first partial stroke of armature 11 , armature 11 moves piston 15 along with it, so that armature 11 and piston 15 carry out a mutual stroke in the subsequent partial stroke of armature 11 . After pressure chamber inlet 28 is closed, the mutual partial stroke of armature 11 and piston 15 produces a pressure increase in pressure chamber 14 and in the part of fuel injector 1 that is flow-connected to outlet 18 of electromagnetic pressure intensifier 5 , since fuel injector 1 is closed at this time and piston 15 is therefore operating on a closed volume of liquid. When fuel injector 1 opens after a predefined pressure increase has been reached, at least part of the fuel whose pressure has been increased by electromagnetic pressure intensifier 5 is injected into the combustion chamber or into the intake manifold of the internal combustion engine.
[0036] After or shortly before or simultaneous with the closing of fuel injector 1 , exciter coil 10 is de-energized, so that piston 15 and armature 11 execute a mutual return stroke in the direction of stop 22 due to the force effect from second return spring 21 . 2 . After piston 15 has reached stop 22 , armature 11 alone executes an additional return stroke due to the force effect from first return spring 21 . 1 . Due to this motion of armature 11 relative to piston 15 , pressure chamber 28 is again opened, so that liquid flows from inlet channel 16 and/or antechamber 23 into pressure chamber 14 and into fuel injector 1 downstream from outlet 18 of electromagnetic pressure intensifier 5 , and in so doing replaces the quantity of fuel injected in the last injection. | A fuel injector of a fuel injecting device that is known is provided with an intensifier piston, which intensifies the pressure of the liquid supplied to the fuel injector from a rail pressure to a higher pressure by hydraulic transmission. The disadvantage is that this type of pressure intensification is very expensive and complicated. In the device according to the present invention, the pressure intensification is simpler and more economical. The present invention provides for at least one electromagnetic pressure intensifier to be provided on at least one fuel injector. | 5 |
FIELD OF THE INVENTION
The present invention relates to methods and compositions for fracturing subterranean formations. In particular, the present invention provides a novel fracturing fluid for fracturing such formations.
BACKGROUND OF THE INVENTION
In order to increase the productivity of oil and gas wells, or to bring back into production wells that have essentially gone dry, it is common practice to conduct a procedure known as fracturing the well. In such a procedure, fluids known as fracturing fluids, are injected into the well at very high hydrostatic pressures. The fluids are typically viscous gels, and act under pressure to open pores and cracks in the formation, thereby to increase the overall permeability of the well. Typically, the fluids also are used to transport proppants, such as sand or ground walnut shells into the cracks and pores, thereby to ensure that the pores and cracks formed during fracturing remain open under the lower pressures that will exist after fracturing, when the well is producing.
The fluid that has been used to fracture the formation is removed by the introduction of viscosity lowering agents into same, which permit the fluid to be more easily pumped from the formation. These agents are known as breakers because they tend to break down the fracturing gel. Breakers can act on a gel in a number of ways, such as by the random oxidation of polymers to shorten the chain length thereof. In the present invention, a breaker is utilized to adjust the pH of a gel, to break same by hydrolysis. The pH of the resulting formulation in accordance with the present invention can generally range from between about 1.0 to about 2.0. However, most preferably, the pH will range from 1.4 and below.
The fracturing fluid of the present invention is a phosphate alkyl ester gel. It is known that a gel can be produced by mixing trivalent cations, such as aluminum, with a phosphate alkyl ester. However, gels obtained with known phosphate alkyl esters have not been commercially acceptable, because the viscosity developed with same has been insufficient or slow to develop.
Phosphate alkyl esters may be mono-esters, di-esters or tri-esters. In the mono-ester, one primary mono-hydric alcohol, of C 5 -C 16 length is ester linked to a phosphate. A di-ester has two such alkyl alcohols linked to a phosphate. A tri-ester has three alkyl alcohols linked to it. As disclosed in Canadian Patent Application No. 2,216,325, commonly owned by the present applicant, commercially valuable gels are feasible with a di-ester content above 50%, preferably above 65%, and a tri-ester content below 5%. The remainder may be mono-ester.
In the aforementioned copending Canadian Application No. 2,216,325, gel development is enhanced in two important ways. First, the phosphate alkyl esters are neutralized with primary amines. Secondly, the applicants utilize a surfactant to enhance gel development. An appropriate surfactant is ammonium alkyl (C 6 -C 20 ) sulfate.
In the present invention, similar or increased gel development is accomplished by reacting the phosphate alkyl esters with a mineral acid, preferably sulfuric acid, before mixing the ester with the hydrocarbon being gelled. This step accomplishes two important purposes. First, the acid treatment tends to increase the dialkyl percentage of the ester, and secondly, the sulfuric acid reacts with the alkyl phosphate esters to form alkyl sulfates, which act as a surfactants, to assist in the subsequent cross link reaction.
The prior art, in particular U.S. Pat. No. 4,787,994 shows the use of sulfuric acid (or alternatively a low molecular weight sulphonic acid such as xylene sulphonic acid) with mono- or di-ester alkyl phosphates, to preferentially attract the alkali metal ions of the activator (such as sodium aluminate). This is disclosed as being effective to increase the available cross-linking sites in the alkyl phosphate ester, and thereby permit increased cross-linking by the aluminate ions. The prior art does not, however, disclose the use of sulfuric acid to increase the di-ester content of a solution containing mono-, di-, and tri-ester alkyl phosphates. Nor does the art show the formation of alkyl sulfates in situ. The present invention, moreover, does not utilize an alkali aluminate activator, but rather an iron citrate one, which is a departure from the prior art, in that the pH of the solution with an aluminate activator is in the 3.5-4.0 range, as opposed to the 1.0-2.0 range of the present invention.
Accordingly, it will be understood that the present invention represents a significant advance over the system described and claimed in Applicant's Canadian Patent Application No. 2,216,325, while sharing some part of the technology described herein. The present invention, moreover, is an advance over the technology of U.S. Pat. No. 4,787,994, in that it does not require the use of an alkali aluminate activator.
In order to break the gel of the present invention the preferred breaker is a pH adjusting breaker, such as calcium oxide or sodium carbonate. It is preferred that the breaker be encapsulated in a porous inert substance, such as nylon.
In a broad aspect, then, the present invention relates to a fracturing fluid for use in fracturing subterranean formations comprising: a hydrocarbon base; and acidified alkyl phosphate esters complexed with metallic cations, to form a gel, in said hydrocarbon base.
BRIEF DESCRIPTION OF THE DRAWINGS
In drawings that illustrate the present invention by way of example:
FIG. 1 is a graph illustrating the relative Brookfield viscosities of a phosphate ester composition prepared according to the present invention, and a conventional phosphate ester composition;
FIG. 2 is a graph illustrating the effect of acid concentration on viscosity in a fluid according to the present invention;
FIG. 3 is a graph illustrating the effect of activator loading on viscosity; and
FIG. 4 is a graph illustrating the effect of gellant loading on viscosity formation.
DETAILED DESCRIPTION
The phosphate ester gels of the present invention are made from primary mono-hydric alcohols of C 5 -C 16 chain length. It is preferred to utilize alcohols of chain length C 8 -C 12 , but it will be understood that since the gels of the present invention are intended to act on hydrocarbon fluids, such as diesel fuel, kerosene, or other common hydrocarbon fluids, the selection of an optimal chain length alcohol will be a matter of choice for one skilled in the art. The alkyl alcohols are combined with phosphates, by known techniques to produce mono- di and tri-alkyl esters which may generally be represented as follows:
The relative proportions of mono-alkyl, di-alkyl and tri-alkyl esters are important. The applicant has discovered that the di-alkyl phosphate ester content must be at least 50% for any gel development to occur, and must be at least 65% for commercially feasible gel to form. Moreover, tri-alkyl phosphate ester content must be lower than 5%, or poor gel rheological characteristics will result. There must be at least a small percentage of mono-alkyl phosphate ester present to initiate gelling.
In order to increase the di-alkyl content of the ester, commercially available alkyl phosphate preparation is acidified with sulfuric acid. This increases the di-alkyl content of the alkyl phosphate ester, and also results in the formation of sulfates, which are then available as surfactants.
Moreover, acidifying the phosphate ester mixture will lower the pH thereof, which will also enhance gel viscosity. It will be understood that, in view of the teaching of the present invention (in particular having regard to FIG. 2 ), a person skilled in the art will find the selection of the appropriate quantity of acid, of a desired strength, to be an obvious matter of choice involving no undue experimentation or the like. In this regard, it must be understood that the design criteria for any particular fracturing job will vary and it is not sufficient merely to always obtain the maximum, or any given, viscosity. Moreover, since the chemical environment in a formation will be unique, the fracturing fluid for it must be adjusted according, using the application of well accepted principles of engineering, and the present invention.
The partially acidified phosphate ester is then mixed in the hydrocarbon fluid to be gelled, with a trivalent cation, preferably iron ferric, supplied as ferric citrate, pH about 2.5.
The phosphate-alkyl esters and cations form a mesh-like network in the hydrocarbon fluid, resulting in a gel. The hypothesized reaction is as follows:
It will be understood that such a network will transform the essentially two dimensional phosphate-alkyl ester to a three dimensional, very viscous gel.
The gelling rate is moreover greatly enhanced in the presence of a surfactant. The sulphate groups formed in the present invention provide the necessary alteration of surface chemistry to result in enhancement of reaction rates.
The effects of the present invention is illustrated in FIG. 1 . As will be appreciated, the use of sulfuric acid to treat the mixed alkyl phosphate ester base fluid results in about a two-fold viscosity increase. The enhanced viscosity illustrated in FIG. 1 was obtained using sulfuric acid added to obtain a pH of 0.55. This represented a sulfuric acid concentration of 10%. The effect of varying sulfuric acid concentration is illustrated in FIG. 2, from which it can be appreciated that the selection of an appropriate acid concentration will be a matter of choice to one skilled in the art, in view of the teachings of this invention. It will be understood, however, that the acid should be permitted to react with the alkyl phosphate ester for 1-2 hours before activation, to ensure maximum di-ester formation.
To form a gel in a hydrocarbon solvent according to the present invention, 0.2-1.5% (by weight of hydrocarbon) acidified phosphate alkyl ester is utilized in a refined hydrocarbon, such as diesel fuel or kerosene. As discussed above, acidification levels are a matter of choice. Activator is added in about the same ratio as the gellant (i.e., a ratio of about 1:1, typically). However, a significant advantage of the present invention over the prior systems, is that it is not sensitive to overloading of activator. As illustrated in FIG. 3, the gels of the prior art may easily be over-activated, and at activator levels of only about 5% over ideal, show significant viscosity reduction. At levels of about 125% of gellant, viscosity is typically lost. This is a significant disadvantage of the prior systems, because precision is sometimes difficult to obtain in the field. The system of the present invention, however, is not affected adversely by even 200% loading of activator relative to gellant. About 80% of the maximum gel viscosity is attained, typically, in the first minute of mixing of the acidified ester with the activator. The constituents can and advantageously are, therefore, blended “on the fly” as they are pumped into a formation.
Referring lastly to FIG. 4, the effect of total gellant loading on viscosity is shown. To illustrate that selection of the amount of gellant to be added to a fluid to be gelled will be a matter of choice for one skilled in the art and apprised of the present invention.
The gel may be broken by the use of pH adjusting breakers, such as soda ash, caustic, lime, amines, and acids.
It will be appreciated, therefore, that the present invention provides a reliable viscous gel for use with hydrocarbon solvents, which can be broken on a consistent and effective basis. | A fracturing fluid is provided for use in fracturing subterranean formations. It comprises a hydrocarbon base. In the base, acidified alkyl phosphate esters are complexed with metallic cations, to form a gel. | 8 |
The government has rights in this invention pursuant to Contract No. DAAK20-81-C-0433 awarded by the Department of the Army.
BACKGROUND OF THE INVENTION
The present invention relates in general to a thin film deposition technique employing cathode sputtering, and pertains, more particularly to a co-sputtering cathode system or apparatus for the deposition of doped thin films particularly on large area substrates.
Planar magnetron sputtering has been used as a general purpose technique for the deposition of thin films in both laboratory and production applications. An advantage of planar magnetron sputtering is that it permits relatively high rates of deposition, limits umwanted substrate bombardment and heating, and is particularly adapted for use with large flat substrates without requiring special planetary tooling or excessively large throw distances. Planar magnetron sputtering is characterized by a visible plasma area magnetically confined to a selected region or regions of the cathode which are the only areas with significant emission of sputtered material. The emitting areas or zones assume the form of closed figures in the target plane.
For many applications it is desired to deposit doped films on large area substrates with close control of both uniformity and dopant level. The deposition of doped films has involved the use of a doped target. However, techniques involving doped targets are subject to variations in consistancy of the deposited film particularly over a time span due to concentration or depletion of dopant in the target. Additional disadvantages associated with doped targets are that they may be difficult or impossible to fabricate and that there is a loss in flexibility in changing dopant material or doping level.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an improved sputtering cathode apparatus or system for the deposition of doped thin films particularly on large area substrates.
Another object of the present invention is to provide an improved planar magnetron sputtering apparatus for the deposition of doped films and in which the deposition is to be closely controlled both as to uniformity thereof and dopant level.
A further object of the present invention is to provide a co-sputtering cathode system particularly adapted for the deposition of doped thin films on large area substrates and without requiring the use of a doped target. By eliminating the necessity of a doped target in accordance with the present invention there is also eliminated variations that occur in such doped target deposition films due to concentration or depletion of dopant in the target.
Still another object of the present invention is to provide a planar magnetron sputtering apparatus in which the dopant level may be precisely and uniformly controlled.
Another object of the present invention is to provide an improved planar magnetron sputtering apparatus or system which is more adaptable in its operation in that one dopant may be readily replaced by another without disturbing the host target assembly. This is accomplished in accordance with the present invention by virtue of the use of separately disposed host and dopant materials rather than with the use of a doped target material.
To accomplish the foregoing and other objects of this invention there is provided a sputtering cathode apparatus for the deposition of a doped thin film on a substrate. The apparatus and system of the present invention is particularly useful in the deposition of doped thin films on large area substrates. The substrate typically moves over the sputtering cathode apparatus which is stationary. The apparatus of this invention comprises a planar magnetron sputtering means including means defining a frame-shaped plasma area and having a host target material disposed in the magnetron area. The host target material may comprise zinc sulfide. There is also provided a diode sputtering means disposed inside the framed area and thus outside of the plasma sputtering area. This diode-sputtering means comprises a dopant material in the form of a diode cathode. The dopant material may comprise manganese. Means are provided for electrically exciting both the host target material and the dopant material to provide for co-deposition of these materials. The means for electrically exciting the materials may comprise separate RF sources. For RF sputtering, co-excitation of the sources is desired to prevent beating of RF modes. The co-excitation assures that the sources will not be out of phase. The dopant level is controlled by the relative power fed to the respective host and dopant targets.
BRIEF DESCRIPTION OF THE DRAWINGS
Numerous other object features and advantages of the invention should now become apparent upon a reading of the following detailed description taken in conjunction with the accompanying drawing, in which:
FIG. 1 is a plan view of the sputtering cathode system of this invention illustrating the phosphor host target and dopant target;
FIG. 2 is a cross sectional view of the cathode system illustrated in FIG. 1 showing further details, particularly of the planar magnetron sputtering apparatus; and
FIG. 3 is an electric circuit associated with the apparatus of FIGS. 1 and 2.
DESCRIPTION OF PREFERRED EMBODIMENT
With reference to the drawings, and in particular FIGS. 1 and 2, there is shown a sputtering cathode apparatus for the deposition of a doped thin film on a substrate 10. The system or apparatus that is described includes a magnetron cathode for the host material which is preferrably sputtered at a relatively high rate for process efficiency in combination with a separate, electrically isolated, diode cathode for the dopant material. The substrate 10 is passed over the assembly in linear motion as indicated by the arrow 12 and at a sufficient rate to average the deposition of the host and dopant. In connection with the magnetron cathode, there is defined a plasma region from which sputtering takes place and which is in the shape shown in FIG. 1 in the form of rectangular-shaped picture frame with a rectangular region in the center from which no sputtering takes place. It is this center region that has disposed therein the electrically isolated diode cathode for the dopant material.
FIG. 1 illustrates the picture frame configuration of the phosphor host target 14 which is disposed in the magnetron plasma area illustrated between the permanent magnets shown in FIG. 2. As illustrated in FIG. 1 there is also provided a dopant target 16 which is outside the aforementioned magnetron plasma area in a central, rectangular-shaped area 18. FIG. 2 also illustrates the host target 14 and the dopant target 16 each being respectively excited from an RF source 24, 26. In FIG. 2 the connections from each RF source are shown schematically. Associated with each of these sources is a co-excitation device 22. In the case of RF sputtering, co-excitation of the power supplies used for the separate targets is desired to prevent the beating of RF modes. Further details of the circuitry are depicted in FIG. 3 and discussed in further detail hereinafter.
The host target material may comprise, for example, zinc sulfide. The dopant target material may, for example, comprise manganese. As indicated previously this substrate is passed by linear motion over the sputtering cathode system. The distance from the targets to the substrate illustrated by dimension d in FIG. 2 may be on the order of about 3 inches.
FIG. 2 also shows further details of the planar magnetron sputtering apparatus. This apparatus includes a support member 30 which may be constructed of magnetic stainless steel. This preferably has a form of water jacket 32. Cooling fluid is introduced into the support member 30 for the purpose of keeping it cool. A further support member 34 includes means for supporting a series of permanent magnets 36. FIG. 2 illustrates the manner in which the permanent magnets 36 are placed indicating north and south poles by the respective designations N and S. The support member 34 is preferably constructed of a nonmagnetic aluminum. It is noted that the plasma region is established basically between the permanent magnets such as in the area A designated in FIG. 2. The width of this area also corresponds with the width of the overlaying host target material 14.
A copper sheet 40 also essentially in a picture frame shape is supported over the planar magnetron sputtering means. There is also provided a thin copper plate 42 for support of the dopant material 16. The plates 40 and 42 are preferably provided in integral single piece construction with the plate separated by appropriate insulation layers 44. The copper plates 40 and 42 are made, for example, 1/8-1/4 inch thick. These plates are nonmagnetic and provide good heat conduction to the support base 30.
As indicated previously, the magnetron cathode and diode cathodes are co-excited. FIG. 2 schematically illustrates this co-excitation. FIG. 3 gives some further circuit detail. In FIG. 3 there is shown an RF oscillator 50 which has output lines 51 and 52 coupling to the respective RF amplifiers 55 and 56. The RF amplifier 55 has an output line 57 and that couples to one impedance matching network 58. Similarly, the RF amplifier 56 has an output line 60 that couples to a second impedance matching network 62. Once again the RF oscillator 50 feeds signals to the RF amplifiers that are in phase so that the proper co-excitation occurs. In FIG. 3 the output of the impedance matching network is shown coupling to the host target 14 while the output of the impedance matching network 62 is shown coupling to the dopant target 60.
Having described a limited number of embodiments of the present invention, it should now be apparent to those skilled in the art that numerous other embodiments are contemplated as following within the scope of this invention. For example, one host target material and dopant material has been described herein but it is understood that the concepts of the invention may be applied in the deposition of other types of doped thin films. Also, in accordance with the invention the percentage of doping is readily controlled by controlling the gain of the RF amplifiers 55 and 56. The gain of the amplifers can be controlled separately so as to control dopant level. Also, in accordance with the invention the replacement of one dopant by another is affected quite easily by demounting the dopant backing plate with its target and simply replacing it. This can be accomplished quite quickly without disturbing the host target assembly. | The deposition of thin films is carried out by a co-sputtering cathode technique particularly suited for deposition of doped thin films on large area substrates. A relatively large planar magnetron sputtering apparatus having a rectangular (picture frame shaped) plasma region is provided to obtain efficient sputtering of the host material. A vacant center area defined by the plasma region is provided for diode sputtering of the dopant. In RF sputtering, co-excitation of the power source is desired to prevent RF mode beating. | 7 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This Nonprovisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No. 10-2004-0015057 filed in Korea on Mar. 5, 2004, the entire contents of which are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to an apparatus and method for driving a plasma display panel, and more particularly, to an apparatus and method for driving a plasma display panel, wherein electromagnetic interference is minimized and stability is improved.
BACKGROUND OF THE RELATED ART
[0003] A plasma display panel (hereinafter, referred to as a ‘PDP’) is adapted to display an image including characters or graphics by light-emitting phosphors with ultraviolet of 147 nm generated during the discharge of a gas such as He+Xe, Ne+Xe or He+Ne+Xe. This PDP can be easily made thin and large, and it can provide greatly increased image quality with the recent development of the relevant technology. Particularly, a three-electrode AC surface discharge type PDP has advantages of lower driving voltage and longer product lifespan as a voltage necessary for discharging is lowered by wall charges accumulated on a surface upon discharging and electrodes are protected from sputtering caused by discharging.
[0004] FIG. 1 is a perspective view illustrating the structure of a discharge cell of a conventional three-electrode AC surface discharge type PDP.
[0005] Referring now to FIG. 1 , a discharge cell of a three-electrode AC surface discharge type PDP includes a scan electrodes Y and a sustain electrode Z which are formed on the bottom surface of an upper substrate 10 , and an address electrode X formed on a lower substrate 18 . The scan electrodes Y includes a transparent electrode 12 Y, and a metal bus electrode 13 which has a line width smaller than that of the transparent electrode 12 Y and is disposed at one side edge of the transparent electrode. Further, the sustain electrode Z includes a transparent electrode 12 Z, and a metal bus electrode 13 Z which has a line width smaller than that of the transparent electrode 12 Z and is disposed at one side edge of the transparent electrode.
[0006] The transparent electrodes 12 Y and 12 Z, which are generally made of ITO (indium tin oxide), are formed on the bottom surface of the upper substrate 10 . The metal bus electrodes 13 Y and 13 Z are generally formed on the transparent electrodes 12 Y and 12 Z made of metal such as chromium (Cr), and serves to reduce a voltage drop caused by the transparent electrodes 12 Y and 12 Z having high resistance. On the bottom surface of the upper substrate 10 in which the scan electrodes Y and the sustain electrode Z are placed parallel to each other is laminated an upper dielectric layer 14 and a protective layer 16 . The upper dielectric layer 14 is accumulated with a wall charge generated during plasma discharging. The protective layer 16 is adapted to prevent damages of the upper dielectric layer 14 due to sputtering caused during plasma discharging, and improve efficiency of secondary electron emission. As the protective layer 16 , magnesium oxide (MgO) is generally used.
[0007] A lower dielectric layer 22 and barrier ribs 24 are formed on the lower substrate 18 in which the address electrode X is formed. A phosphor layer 26 is applied to the surfaces of both the lower dielectric layer 22 and the barrier ribs 24 . The address electrode X is formed on the lower substrate 18 in the direction in which the scan electrodes Y and the sustain electrode Z intersect with each other. The barrier ribs 24 are in the form of stripe or lattice to prevent leakage of an ultraviolet and a visible light generated by discharging to an adjacent discharge cell. The phosphor layer 26 is excited with an ultraviolet generated during the plasma discharging to generate any one visible light of red, green and blue lights. An inert mixed gas is injected into the discharge spaces defined between the upper substrate 10 and the barrier ribs 24 and between the lower substrate 18 and the barrier ribs 24 .
[0008] This PDP is driven with one frame being time-divided into a plurality of sub-fields having a different number of emission in order to implement the gray scale of an image. Each of the sub fields is divided into an initialization period for initializing the entire screen, an address period for selecting a scan line and selecting a cell from the selected scan line, and a sustain period for implementing gray scales according to the number of discharging.
[0009] In this time, the initialization period is divided into a set-up period where a ramp-up waveform is applied, and a set-down period where a ramp-down waveform is applied. If it is desired to display an image with 256 gray scales, a frame period (16.67 ms) corresponding to 1/60 seconds is divided into eight sub-fields SF 1 to SF 8 , as shown in FIG. 2 . Each of the sub-fields SF 1 to SF 8 is subdivided into the initialization period, the address period and the sustain period, as described above. The initialization period and the address period of each of the sub-fields SF 1 to SF 8 are the same every sub-field, whereas the sustain period increases in the ratio of 2 n (where, n=0,1,2,3,4,5,6,7) in each sub-field.
[0010] FIG. 3 is a block diagram of an apparatus for driving a PDP in the prior art.
[0011] Referring to FIG. 3 , the conventional apparatus for driving the PDP includes an address driving unit 32 for driving address electrodes X 1 to Xm disposed in a panel 30 , a scan driving unit 34 for driving scan electrodes Y 1 to Yn disposed in the panel 30 , a sustain driving unit 36 for driving sustain electrodes Z 1 to Zn disposed in the panel 30 , a driving voltage generator 40 for supplying driving voltages to the driving units 32 , 34 and 36 , and a timing controller 38 for supplying control signals SCS 1 to SCS 3 to the driving units 32 , 34 and 36 .
[0012] The driving voltage generator 40 generates a variety of driving voltages so that a driving waveform as shown in FIG. 4 can be generated, and supplies the generated voltages to the address driving unit 32 , the scan driving unit 34 and the sustain driving unit 36 . For example, the driving voltage generator 40 generates voltages, such as Vsetup, −Vw, Vr and Vs, and supplies the voltages to the scan driving unit 34 . It generates a voltage Vs, and provides the voltage to the sustain driving unit 36 . Furthermore, the driving voltage generator 40 generates a voltage Va, and provides it to the address driving unit 32 .
[0013] The timing controller 38 generates a variety of the switching control signals so that the driving waveform as shown in FIG. 4 can be generated, and supplies the generated switching control signals to the address driving unit 32 , the scan driving unit 34 and the sustain driving unit 36 . For example, the timing controller 38 generates a first switching control signal SCS 1 and a second switching control signal SCS 2 , and supplies the signals to the scan driving unit 34 and the sustain driving unit 36 , respectively. Also, the timing controller 38 generates a third switching control signal SCS 3 and a data clock DCLK, and supplies them to the address driving unit 32 .
[0014] The address driving unit 32 serves to supply image data data, which are received from the outside, to the address electrodes X 1 to Xm, under the control of the data clock DCLK and the third switching control signal SCS 3 , both of which are supplied from the timing controller 38 .
[0015] The scan driving unit 34 supplies a reset pulse, a scan pulse scan and a sustain pulse sus to the scan electrodes Y 1 to Ym, under the control of the first switching control signal SCS 1 outputted from the timing controller 38 .
[0016] The sustain driving unit 36 supplies a positive polarity voltage (Vs), the sustain pulse sus and an erase pulse erase to the sustain electrodes Z 1 to Zn, under the control of the second switching control signal SCS 2 outputted from the timing controller 38 .
[0017] The driving waveform applied to the electrodes will now be described in detail with reference to FIG. 4 . In a set-up period of the initialization period, a ramp-up waveform Ramp-up is applied to all the scan electrodes Y at the same time. A weak discharge is generated within cells of the entire screen by the ramp-up waveform Ramp-up, thus generating wall charges within the cells. In the set-down period, after the ramp-up waveform Ramp-up is applied, a ramp-down waveform Ramp-down, which falls from a voltage of the positive polarity that is lower than the peak voltage of the ramp-up waveform Ramp-up, is applied to the scan electrodes Y at the same time. The ramp-down waveform Ramp-down generates a weak erase discharge within the cells to erase the wall charges generated by a set-up discharge and unnecessary charges among space charges and also to allow the wall charges necessary for an address discharge to uniformly remain within the cells of the entire screen.
[0018] In the address period, simultaneous when the scan pulse scan of the negative polarity is sequentially applied to the scan electrodes Y, the data pulse data of the positive polarity is applied to the address electrodes X. As a voltage difference between the scan pulse scan and the data pulse data and the wall voltage generated in the initialization period are added, the address discharge is generated within cells to which the data pulse data is applied. The wall charges are generated within cells selected by the address discharge.
[0019] Meanwhile, during the set-down period and the address period, a positive DC voltage of the sustain voltage level (Vs) is applied to the sustain electrodes Z.
[0020] In the sustain period, the sustain pulse sus is alternately applied to the scan electrodes Y and the sustain electrodes Z. Then, in cells selected by the address discharge, a sustain discharge is generated in the form of a surface discharge between the scan electrodes Y and the sustain electrodes Z whenever every sustain pulse sus is applied as wall voltages within the cells and the sustain pulse sus are added. After the sustain discharge is completed, an erase ramp waveform erase having a small pulse width is applied to the sustain electrodes Z to erase the wall charges within the cells.
[0021] In such a conventional PDP, during the sustain period, the scan electrodes Y and the sustain electrodes Z are alternately applied with the sustain pulse sus. At this time, when the sustain pulse sus is supplied to the scan electrodes Y, the sustain electrodes Z is supplied with the ground voltage GND. When the sustain pulse sus is provided to the sustain electrodes Y, the scan electrodes Z is supplied with the ground voltage GND. That is, since a high current flows when the sustain pulse sus is provided to a given electrodes Y or Z, the remaining electrode to which the sustain pulse sus is not supplied is connected to the ground voltage GND, so that the operation is stabilized. However, during the sustain period, in order for the scan electrodes Y and the sustain electrodes Z to be connected to the sustain pulse sus and the ground voltage GND in an alternate way, switching means included in the scan driving unit 34 and the sustain driving unit 36 perform lots of switching operations. Accordingly, there is a problem in that high EMI is generated. Furthermore, in the prior art, since lots of switching means (i.e., line is long) are needed in order for the scan electrodes Y and the sustain electrodes Z to be connected to the ground voltage GND, there is a problem in that additional noise is generated.
[0022] Generally, in order to stabilize the operation of a PDP, any one of the scan electrodes Y and the sustain electrodes Z has to be connected to the ground voltage GND so that a voltage level can be stabilized. Practically, however, if any one of the scan electrodes Y and the sustain electrodes Z is connected to the ground voltage GND, introduction of external noise, generation of EMI, etc. can be minimized. In the prior art, however, since a variety of driving waveforms are supplied to the scan electrodes Y and the sustain electrodes Z, it is difficult to secure the stability of a PDP.
[0023] Moreover, in the prior art, the scan driving unit 34 and the sustain driving unit 36 include switching means which are connected to the scan electrodes Y and the sustain electrodes Z, respectively, in a push-pull type. If the switching means are connected in the push-pull type as such, lots of the switching means are needed. As a result, there are problems in that the manufacture cost is increased, leakage current is generated, etc.
SUMMARY OF THE INVENTION
[0024] Accordingly, the present invention has been made in view of the above problems occurring in the prior art, and it is an object of the present invention to provide an apparatus and method for driving a plasma display panel, wherein electromagnetic interference can be minimized and stability can be also improved.
[0025] To achieve the above object, according to the present invention, there is provided an apparatus for driving a PDP, including a plurality of scan electrodes and sustain electrodes, which are formed parallel to each other, and a scan driving unit for alternately supplying sustain pulses of the positive polarity and the negative polarity to the scan electrodes during a sustain period, wherein the sustain electrodes are connected to a ground voltage source, and thus always keep a ground voltage.
[0026] The scan driving unit includes a first switching means disposed between a sustain voltage source of the positive polarity and the scan electrodes, a second switching means disposed between a sustain voltage source of the negative polarity and the scan electrodes, a third switching means disposed between the ground voltage source and the scan electrodes, and fourth switching means and diodes, which are connected between a common terminal of the first to third switching means and the scan electrodes, respectively, in a parallel manner.
[0027] If the first switching means is turned on, the voltage of the positive polarity of the sustain voltage source is applied to the scan electrodes as the sustain pulse of the positive polarity through the first switching means and the diodes.
[0028] If the second switching means and the fourth switching means are turned on, the sustain pulse of the negative polarity is applied to the scan electrodes.
[0029] After the sustain pulse of the positive polarity is applied, the third switching means and the fourth switching means are turned on, and after the sustain pulse of the negative polarity is applied, the third switching means are turned on. Thus, the voltage of the ground voltage source is applied to the scan electrodes.
[0030] The scan driving unit includes a first switching means disposed between a sustain voltage source of the positive polarity and the scan electrodes, a second switching means disposed between a sustain voltage source of the negative polarity and the scan electrodes, a third switching means disposed between the ground voltage source and the scan electrodes, fourth switching means respectively disposed between the second switching means and the scan electrodes, and fifth switching means and diodes, which are connected between a common terminal of the first and third switching means and the scan electrodes, respectively, in a parallel manner.
[0031] If the first switching means is turned on, the voltage of the positive polarity of the sustain voltage source is applied to the scan electrodes as the sustain pulse of the positive polarity through the first switching means and the diodes.
[0032] If the second switching means and the fourth switching means are turned on, the sustain pulse of the negative polarity is applied to the scan electrodes.
[0033] After the sustain pulse of the positive polarity is applied, the third switching means and the fifth switching means are turned on, and after the sustain pulse of the negative polarity is applied, the third switching means are turned on. Thus, the voltage of the ground voltage source is applied to the scan electrodes.
[0034] According to the present invention, there is provided a method of driving a PDP, including the steps of alternately supplying sustain pulses of the positive polarity and the negative polarity to scan electrodes during a sustain period of sub-fields, and supplying a ground voltage to sustain electrodes, which are formed parallel to scan electrodes, during a sub-field period.
[0035] In the present invention, since sustain electrodes always keep a ground voltage, introduction of external noise, generation of EMI, etc. can be minimized. Furthermore, in the present invention, sustain electrodes are always kept to a ground voltage, i.e., the flow path of current shortens. Due to this, generation of additional noise can be prevented, and the stability of a PDP can be thus secured.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] Further objects and advantages of the invention can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings in which:
[0037] FIG. 1 is a perspective view illustrating the structure of a discharge cell of a conventional three-electrode AC surface discharge type PDP;
[0038] FIG. 2 shows one frame of a PDP;
[0039] FIG. 3 is a block diagram of an apparatus for driving a conventional PDP;
[0040] FIG. 4 is a waveform showing a method of driving a conventional PDP;
[0041] FIG. 5 is a block diagram showing an apparatus for driving a PDP according to an embodiment of the present invention;
[0042] FIG. 6 is a detailed circuit diagram of the scan driving unit shown in FIG. 5 ;
[0043] FIG. 7 shows sustain pulses supplied to scan electrodes corresponding to the timing diagram of the switches shown in FIG. 6 ;
[0044] FIG. 8 is another detailed circuit diagram of the scan driving unit shown in FIG. 5 ; and
[0045] FIG. 9 shows sustain pulses supplied to scan electrodes corresponding to the timing diagram of the switches shown in FIG. 8 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0046] Preferred embodiments of the present invention will be described in more detail with reference to the drawings.
[0047] FIG. 5 is a block diagram showing an apparatus for driving a PDP according to an embodiment of the present invention.
[0048] Referring to FIG. 5 , the apparatus for driving the PDP according to an embodiment of the present invention includes a address driving unit 52 for driving address electrodes X 1 to Xm disposed in a panel 50 , a scan driving unit 54 for driving scan electrodes Y 1 to Yn disposed in the panel 50 , a driving voltage generator 58 for applying a driving voltage to the driving units 52 , 54 , and a timing controller 56 for applying control signals SCS 1 , SCS 2 to the driving units 52 , 54 . At this time, sustain electrodes Z 1 to Zn (omitted) disposed in the panel 50 are connected to a ground voltage GND.
[0049] The driving voltage generator 58 generates a variety of driving voltages, and supplies the generated voltages to the address driving unit 52 and the scan driving unit 54 so that a predetermined driving waveform can be generated.
[0050] The timing controller 56 generates various switching control signals, and applies them to the address driving unit 52 and the scan driving unit 54 so that a predetermined driving waveform can be generated. For example, the timing controller 56 generates a first switching control signal SCS 1 , and applies it to the scan driving unit 54 . It also generates a second switching control signal SCS 2 and a data clock DCLK, and applies them to the address driving unit 52 .
[0051] The address driving unit 52 supplies image data data, which are supplied from the outside, to the address electrodes X 1 to Xm according to the data clock DCLK and the second switching control signal SCS 2 , both of which are supplied from the timing controller 56 .
[0052] The scan driving unit 54 applies a reset pulse, a scan pulse, and sustain pulses of the negative polarity and the positive polarity to the scan electrodes Y 1 to Ym, according to the first switching control signal SCS 1 that is supplied from the timing controller 56 . At this time, the scan driving unit 5 supplies the sustain pulses, which switch from the negative polarity and the positive polarity, and vice versa, to the scan electrodes Y 1 to Ym in order to generate a sustain discharge together with the sustain electrodes Z 1 to Zn to which the ground voltage GND is always applied.
[0053] FIG. 6 is a detailed circuit diagram of the scan driving unit shown in FIG. 5 .
[0054] Referring to FIG. 6 , the scan driving unit 54 includes a driving voltage supply unit 60 , and fourth switches S 4 connected to the scan electrodes Y 1 to Ym, respectively. The fourth switches S 4 are disposed between the driving voltage supply unit 60 and the scan electrodes Y, and supply the driving voltage received from the driving voltage supply unit 60 to the scan electrodes Y. At this time, the fourth switches S 4 are connected in the open drain manner.
[0055] In this case, the switches according to the present invention can be implemented using MOS TR, FET, IGBT, SCR, and the like. If the fourth switches S 4 are connected in the open drain manner, leakage current between the scan electrodes Y 1 to Yn, etc. can be prevented from occurring. Since the fourth switches S 4 are also disposed in the scan electrodes Y one by one, the number of components mounted in the scan driving unit 54 can be minimized. Further, fourth diodes D 4 , which are respectively connected to the fourth switches S 4 in a parallel manner, are further disposed between the driving voltage supply unit 60 and the scan electrodes Y (where, the fourth diodes D 4 can be diodes within the fourth switches S 4 or external diodes additionally disposed). The fourth diodes D 4 serve to supply the driving voltage, which is supplied from the driving voltage supply unit 60 , to the scan electrodes Y, and also to prevent the driving voltage from the scan electrodes Y from being supplied to the driving voltage supply unit 60 .
[0056] The driving voltage supply unit 60 includes a first switch S 1 connected between a sustain voltage source +Vs of the positive polarity and the fourth switches S 4 , a second switch S 2 connected between a sustain voltage source −Vs of the negative polarity and the fourth switches S 4 , and a third switch S 3 connected between a ground voltage GND and the fourth switches S 4 . The first to third switches S 1 to S 3 are turned on and off under the control of the timing controller 56 .
[0057] FIG. 7 shows sustain pulses supplied to the scan electrodes corresponding to the timing diagram of the switches shown in FIG. 6 .
[0058] The process where the sustain pulses are supplied from the scan driving unit 54 will now be described in detail with reference to FIG. 7 . As shown in FIG. 7 , according to the present invention, during a sustain period, the sustain electrodes Z are kept to the ground voltage GND, and the scan electrodes Y are alternately supplied with the sustain pulse sus+ of the positive polarity and the sustain pulse sus- of the negative polarity (actually, the ground voltage GND is provided between the voltage +Vs, −Vs of the positive polarity and the negative polarity for a predetermined time). Then, as a wall voltage within cells that are selected in a previous address period, and voltage values of the sustain pulse sus+ or sus− of the positive polarity or the negative polarity are added, a sustain discharge is generated in the form of surface discharge between the scan electrodes Y and the sustain electrodes Z whenever the sustain pulses sus+, sus− are applied.
[0059] This will be described in more detail. When the sustain pulse sus+ of the positive polarity is applied, the first switch S 1 is turned on. If the first switch S 1 is turned on, a voltage of the sustain voltage source +Vs of the positive polarity is supplied to the scan electrodes Y 1 to Yn through the first switch S 1 and the fourth diodes D 4 . At this time, the scan electrodes Y 1 to Yn are supplied with the sustain pulse sus+ of the positive polarity.
[0060] After the sustain pulse sus+ of the positive polarity is supplied to the scan electrodes Y 1 to Yn, the third and fourth switches S 3 , S 4 are turned on. If the third switch S 3 is turned on, the ground voltage GND is applied to the scan electrodes Y 1 to Yn through the third and fourth switches S 3 , S 4 .
[0061] After the ground voltage GND is applied to the scan electrodes Y 1 to Yn, the third switch S 3 is turned off and the second switch S 2 is turned on. If the second switch S 2 is turned on, the voltage of the sustain voltage source −Vs of the negative polarity is applied to the scan electrodes Y 1 to Yn through the second and fourth switches S 2 , S 4 . At this time, the scan electrodes Y 1 to Yn are supplied with the sustain pulse sus- of the negative polarity.
[0062] After the scan electrodes Y 1 to Yn are supplied with the sustain pulse sus− of the negative polarity, the third switch S 3 is turned on, and the second and fourth switches S 2 , S 4 are also turned off. If the third switch S 3 is turned on, the ground voltage GND is applied to the scan electrodes Y 1 to Yn via the third switch S 3 and the fourth diodes D 4 . Practically, in the present invention, while this process is repeatedly performed, the sustain pulses sus+, sus− of the positive polarity and the negative polarity are alternately supplied to the scan electrodes Y 1 to Yn.
[0063] On the other hand, in an address period, the second switch S 2 keeps turned on. Further, when the second switch S 2 keeps turned on, the fourth switches S 4 are sequentially turned on to supply the scan pulse scan to the scan electrodes Y. At this time, the address driving unit 52 supplies the data pulse, which is synchronized to the scan pulse scan, to the data lines X 1 to Xm.
[0064] As described above, in the present invention, the sustain electrodes Z are always (during one sub-field period) supplied with the ground voltage GND. If the ground voltage GND is always supplied to the sustain electrodes Z as such, introduction of external noise, generation of EMI, etc., can be minimized, and the stability of a PDP can be improved accordingly.
[0065] Further, in the present invention, the sustain electrodes Z are always connected to the ground voltage GND. Thus, a sustain driving unit as in the prior art can be omitted, and EMI, etc., which is generated due to driving of the sustain driving unit, can be prevented. In addition, in the present invention, since the sustain electrodes Z are directly connected to the ground voltage GND, additional generation of noise can be prevented. Moreover, in the present invention, only one switching means S 4 is connected to each of the scan electrodes Y in the off drain mode. Therefore, the number of components can be minimized, the manufacture const can be reduced, and leakage current between electrodes can be thus prevented.
[0066] Meanwhile, in the present invention, the scan driving unit 54 can be constructed in various forms. For example, according to the present invention, the scan driving unit 54 can be constructed, as shown in FIG. 8 .
[0067] FIG. 8 is another detailed circuit diagram of the scan driving unit shown in FIG. 5 .
[0068] Referring to FIG. 8 , the scan driving unit 54 according to the present invention includes a driving voltage supply unit 64 , and fourth switches S 4 and fifth switches S 5 , which are disposed between scan electrodes Y 1 to Ym respectively.
[0069] The driving voltage supply unit 64 includes a first switch S 1 connected to a sustain voltage source +Vs of the positive polarity, a third switch S 3 connected to the ground voltage GND, and a second switch S 2 connected to a sustain voltage source −Vs of the negative polarity. The first to third switches S 1 to S 3 are turned on and off under the control of the timing controller 56 .
[0070] The fourth switches S 4 are connected between the second switch S 2 and the scan electrodes Y 1 to Ym, respectively, and are turned on and off under the control of the timing controller 56 . The fifth switches S 5 are connected between a common terminal of the first and third switches S 1 , S 3 and the scan electrodes Y 1 to Ym, respectively, and are turned on and off under the control of the timing controller 56 . In this case, the fourth switches S 4 are connected to the fourth diodes D 4 in a parallel manner, and the fifth switches S 5 are connected to the fifth diodes D 5 in a parallel manner. The fourth and fifth diodes D 4 and D 5 serve to prevent a driving voltage, which is supplied from the scan electrodes Y 1 , from being applied to the driving voltage supply unit 64 .
[0071] The process in which the sustain pulse is supplied from the scan driving unit 54 will now be described in detail with reference to FIG. 9 .
[0072] Referring to FIG. 9 , the first switch S 1 is turned on. If the first switch S 1 is turned on, the voltage of the sustain voltage source +Vs of the positive polarity is applied to the scan electrodes Y 1 to Yn via the first switch S 1 and the fifth diode D 5 . At this time, the scan electrodes Y 1 to Yn are supplied with the sustain pulse sus+ of the positive polarity.
[0073] After the scan electrodes Y 1 to Yn are supplied with the sustain pulse sus+ of the positive polarity, the first switch S 1 is turned off, and the third and fifth switches S 3 and S 5 are also turned on. If the third and fifth switches S 3 and S 5 are turned on, the ground voltage GND is applied to the scan electrodes Y 1 to Yn through the third and fifth switches S 3 and S 5 .
[0074] After the ground voltage GND is applied to the scan electrodes Y 1 to Yn, the third and fifth switches S 3 , S 5 are turned off, and the second and fourth switches S 2 , S 4 are also turned on. If the second and fourth switches S 2 , S 4 are turned on, the voltage of the negative polarity of the sustain voltage source −Vs is applied to the scan electrodes Y 1 to Yn through the second switch S 2 and the fourth switch S 4 . At this time, the scan electrodes Y 1 to Yn are supplied with the sustain pulse sus- of the negative polarity.
[0075] After the sustain pulse sus- of the negative polarity is applied to the scan electrodes Y 1 to Yn, the second and fourth switches S 2 , S 4 are turned off, and the third switch S 3 is also turned on. If the third switch S 3 is turned on, the ground voltage GND is applied to the scan electrodes Y 1 to Yn through the third switch S 3 and the fifth diode D 5 . Practically, in the present invention, while this process is repeatedly performed, the sustain pulses sus+, sus− of the positive polarity and the negative polarity are alternately applied to the scan electrodes Y 1 to Yn.
[0076] On the other hand, in an address period, the second switch S 2 keeps turned on. Further, when the second switch S 2 keeps turned on, the fourth switches S 4 are sequentially turned on to sequentially apply scan pulses scan to the scan electrodes Y. At this time, the address driving unit 52 applies the data pulse, which is synchronized to the scan pulse scan, to the data lines X 1 to Xm.
[0077] As such, in the present invention, the sustain electrodes Z are always (during one sub-field period) supplied with the ground voltage GND. If the ground voltage GND is always applied to the sustain electrodes Z as such, introduction of external noise, generation of EMI, etc. can be minimized, and the stability of a PDP can be improved accordingly.
[0078] Furthermore, in the present invention, since the sustain electrodes Z are always connected to the ground voltage GND, a sustain driving unit as in the prior art can be omitted. Generation of EMI, which is generated due to driving of the sustain driving unit, can be also prevented. Moreover, in the present invention, since the sustain electrodes Z are directly connected to the ground voltage GND, additional generation of noise can be prevented.
[0079] While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention. | Disclosed herein is an apparatus and method for driving a plasma display panel, wherein electromagnetic interference is minimized and stability is improved. According to the present invention, the apparatus for driving a PDP includes a plurality of scan electrodes and sustain electrodes, which are formed parallel to each other, and a scan driving unit for alternately supplying sustain pulses of the positive polarity and the negative polarity to the scan electrodes during a sustain period, wherein the sustain electrodes are connected to a ground voltage source, and thus always keep a ground voltage. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International Patent Application No. PCT/US2015/036804, filed Jun. 19, 2015, entitled “POROUS GRANULES CONTAINING MIXTURE OF RUBBER AND SILICA POWDERS” and published as WO 2015/196151, which claims the benefit of U.S. Provisional Patent Application No. 62/015,300, filed Jun. 20, 2014, entitled “POROUS GRANULES CONTAINING MIXTURE OF RUBBER AND SILICA POWDERS”; the contents of all of which are hereby incorporated by reference herein in their entirety.
COPYRIGHT NOTICE
[0002] ©2016 Amtek Research International LLC. A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 37 CFR §1.71(d).
TECHNICAL FIELD
[0003] This disclosure relates to macroscopic, porous granules containing a mixture of silica and rubber powders and, in particular, to incorporation of a rubber powder in the manufacture of vehicle tires and battery separators.
BACKGROUND INFORMATION
[0004] With respect to vehicle tires, the two major ingredients in a rubber compound are the rubber itself and a filler, combined in such a way as to achieve different objectives. Depending on the intended use of the tire, the objective may be to optimize performance, to maximize traction in both wet and dry conditions, or to achieve superior rolling resistance. The desired objective can be achieved through careful selection of one or more types of rubber, together with the type and amount of filler to blend with the rubber.
[0005] In general, there are four major rubbers used: natural rubber, styrene-butadiene rubber (SBR), polybutadiene rubber (BR), and butyl rubber (along with halogenated butyl rubber). The first three are primarily used as tread and sidewall compounds, while butyl rubber and halogenated butyl rubber are primarily used for the inner liner, which is the inside portion that holds the compressed air inside the tire.
[0006] The most popular fillers are carbon black and silica, and there are several types of each. Recycled rubber powder can also be used as part of the formulation. The selection depends on the performance requirements, because they are different for the tread, sidewall, and apex. Other ingredients also come into play to aid in the processing of the tire or to function as anti-oxidants, anti-ozonants, and anti-aging agents. In addition, the “cure package”—a combination of curatives and accelerators—is used to form the tire and provide its elasticity.
[0007] Once the formulation is determined, the next challenge is how to mix all of the ingredients together. The mixing operation is typically a batch operation, with each batch producing more than 200 kg of rubber compound in fewer than three to five minutes. The mixer is a sophisticated piece of heavy equipment with a mixing chamber that has rotors inside. The main function of the mixer is to break down the rubber bale, fillers, and chemicals and mix them with other ingredients.
[0008] The sequence in which the ingredients are added can be critical, as well as the mixing temperature, which can rise as high as 160° C. to 170° C. If the temperature is too high, the compound can be damaged, so the mixing operation is typically accomplished in two stages. The curative package is normally added in the final stage of mixing, and the final mixing temperature cannot exceed 100° C. to 110° C. to prevent occurrence of scorching.
[0009] Once the mixing is completed, the batch is dumped out of the mixer and sent through a series of machines to form a continuous sheet called a “slap.” The slap is then transferred to other areas for bead wire assembly preparation, inner liner calendering, one or both of steel and fabric belt/ply cord calendering, tire sidewall extrusion, and tire tread extrusion.
[0010] Tire components such as tread, sidewall, and apex are prepared by forcing uncured rubber compound through an extruder to shape the tire tread or sidewall profiles. Extrusion is an important operation in the tire manufacturing process because it processes most of the rubber compounds produced from the mixing operation and then prepares various components for the ultimate tire building operation.
[0011] With respect to battery separators, a lead-acid storage battery is commonly found in two modes of design: the valve-regulated recombinant cell and the flooded cell. Both modes include positive and negative electrodes that are separated from each other by a porous battery separator. The porous separator prevents the electrodes from coming into physical contact and provides space for an electrolyte to reside. Such separators are formed of materials that are resistant to the sulfuric acid electrolyte and sufficiently porous to permit the electrolyte to reside in the pores of the separator material, thereby permitting ionic current flow with low resistance between adjacent positive and negative plates.
[0012] Separators for lead-acid storage batteries have been formed of different materials as the technology has developed. Sheets of wood, paper, rubber, PVC, fiberglass, and silica-filled polyethylene have all found use over time. A type of separator currently favored for use in flooded lead-acid storage batteries used in automotive starting-lighting-ignition (SLI) service is the silica-filled polyethylene separator. The microporous polyethylene matrix contains a large fraction of silica particles to provide wettability for the acid electrolyte and to help define the pore structure of the separator. A separator of this type is described in U.S. Pat. No. 7,211,322.
[0013] Another application for flooded lead-acid storage batteries is the traction or deep-cycle battery, which commonly uses a separator made partly of rubber. Traditionally, this separator was a porous hard rubber, cross-linked with sulfur. Improvements on the rubber separator have included the addition of silica particulate filler to the rubber matrix before curing, and cross-linking with electron-beam radiation instead of chemical cross-linking agents.
[0014] All of these rubber-containing separators have the advantageous effects for deep-cycle batteries of promoting long cycle life by controlling water loss during charge. During the charging of the lead-acid storage battery, the active material on the negative electrode is first reduced from lead sulfate to lead. As the available active material is converted to lead, the potential of the electrode is lowered. As the potential on the negative electrode drops, an increasing fraction of the charging current is involved in the evolution of hydrogen by reduction of the hydronium ions present in the adjacent electrolyte. Meanwhile, at the positive electrode, the charging operation is oxidizing the active material from lead sulfate to lead oxide, accompanied by a rise in the potential of the positive electrode. As the potential rises, an increasing fraction of the charging current is involved in the production of oxygen by oxidation of adjacent water molecules and the production of hydronium ions to replace those consumed at the negative electrode. The net effect of the evolution of hydrogen at the negative electrode and the evolution of oxygen at the positive electrode is the consumption of water from the acid electrolyte. This loss of water results in an increase in the concentration of the sulfuric acid, an increase in the resistance of the battery, and eventual failure. By reducing the rate of water loss from the battery, rubber-containing separators extend the service life of deep cycle batteries.
[0015] Despite the advances made in the art with respect to improved separators containing some form of rubber, there continues to be a need for a low-cost separator, with low resistance to ion flow that limits the water loss and improves the cycle life of lead-acid storage batteries used in deep cycle service.
SUMMARY OF THE DISCLOSURE
[0016] This disclosure relates to the use of granules that contain mixtures of silica powder and cross-linked rubber powder in the manufacture of battery separators or vehicle tires. A granule contains silica and rubber powders in proportional amounts that form a silica powder carrier within which rubber powder particles are distributed. Incorporating silica-rubber granules in the manufacturing process of polyethylene separators offers a way to limit water loss in and improve the cycle life of a deep cycle lead-acid battery. Incorporating silica-rubber granules in the manufacturing process of vehicle tires and battery separators affords advantages including easier material handling, reduced production of dust, and reduction in the number of ingredients measured and added to the formulation.
[0017] Additional aspects and advantages will be apparent from the following detailed description, which includes reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIGS. 1A and 1B are optical micrographs showing, respectively, lower and higher magnifications of silica-rubber granules formed by mechanical compression.
[0019] FIGS. 2A and 2B are optical micrographs showing, respectively, surface and cross-sectional views of a polyethylene separator formed from silica-rubber granules as described in Example 2.
[0020] FIG. 3 is a graph showing, by comparison to an acid blank, the hydrogen evolution suppression effect exhibited by the porous separator of Example 2.
[0021] FIG. 4 is a graph showing the antimony suppression effect exhibited by the porous separator of Example 2.
[0022] FIG. 5 is a graph showing the electrical current efficiency achieved by the porous separator of Example 2 in the presence of antimony in the acid electrolyte.
DETAILED DESCRIPTION
[0023] The following describes silica-rubber granules containing a mixture of silica and rubber powders. Additionally, methods of using the silica-rubber granules in the manufacture of vehicle tires and battery separators are described herein. The macroscopic silica-rubber granules are inherently dust-formation suppressing. By comparison, silica particles and rubber particles, such as particles in the 100 nm to 100 micron size range, can release a significant amount of silica and rubber dust as the materials are poured into a hopper during manufacturing.
[0024] Benefits of the dust-formation suppressing silica-rubber granules include less material loss from dust entrained in air during conveying and handling, reduced worker exposure to silica and rubber particle dust, decreased personal protective equipment requirements, and a cleaner workplace. The granules have additional shipping and handling benefits as compared to smaller particles. The increased bulk density of the granules reduces the shipping costs. The low friability and high crush strength facilitate ease of handling. The granules are free-flowing, which results in better conveying and feeding to manufacturing equipment.
[0025] As used herein, “particles” includes agglomerates of particles as well. For example, silica particles can agglomerate together, depending on factors such as the density of silanol groups on the surface of the particles. Precipitated silica agglomerates can be as large as about 40 microns. By contrast, the silica-rubber granules described herein are larger than silica agglomerates. For example, the macroscopic granules can have a size of about 100 microns to about 5 mm or about 500 microns to about 5 mm.
[0026] The silica-rubber granule contains a first amount of a silica powder component and a second amount of a rubber powder component, the first amount of the silica powder component being greater than the second amount of the rubber powder component to form a granule in which the silica powder component is a carrier within which the rubber powder component is distributed.
[0027] The silica powder component and the rubber powder component can be held together by compression-formed adhesion to form the granule. Alternatively, the silica powder component and the rubber powder component can be held together by spray-drying formed adhesion to form the granule. The spray-drying can be from a mixture including a solvent, the silica powder component, and the rubber powder component. A common solvent is water, although other solvents can be used. In many cases, when using compression or spray-drying to form the granule, the addition of a binder will not be required to form the granule.
[0028] The silica powder can contain precipitated silica, precipitated silica derivatives, fumed silica, fumed silica derivatives, or mixtures thereof. There are numerous derivatives of precipitated silica and fumed silica that one of ordinary skill in the art, with the benefit of this disclosure, would understand could be used in the silica-rubber granules. For example, silica particles surface-treated with silane coupling agents or aluminosilicates could be used. The precipitated silica can be amorphous. Furthermore, the precipitated silica can have a surface area of about 50 m 2 /g to about 350 m 2 /g, about 75 m 2 /g to about 300 m 2 /g, about 100 m 2 /g to about 250 m 2 /g, or about 125 m 2 /g to about 200 m 2 /g, as measured by nitrogen adsorption using Brunauer-Emmett-Teller (BET) analysis.
[0029] The rubber powder can contain a cross-linked rubber powder, such as, for example, a cross-linked natural rubber, a cross-linked styrene-butadiene rubber, a cross-linked polybutadiene rubber, a cross-linked butyl rubber, derivatives of any of the foregoing, or combinations of any of the foregoing.
[0030] The silica-rubber granules can contain additives in addition to the silica powder component and the rubber powder component. The choice of additives will generally depend upon the desired ultimate formulation for the end product, such as a vehicle tire or battery separator. In the case of vehicle tires and battery separators, exemplary additives include carbon black, antioxidants, colorant, and lubricant. The additives can be in powder form for compression formation of the granules, but can also be dissolved in a solvent, such as for spray-drying formation of the granules.
[0031] In some cases, the silica-rubber granules contain at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, or at least about 95% of the silica powder component, on a weight-to-weight basis. Likewise, in some cases, the silica-rubber granules contain less than about 40%, less than about 35%, less than about 30%, less than about 25%, less than about 20%, less than about 15%, less than about 10%, or less than about 5% of the rubber powder component, on a weight-to-weight basis. The silica-rubber granule can contain, for example, a ratio, by weight, of the first amount of the silica powder component to the second amount of the rubber powder component from about 3:2 to about 19:2, about 3:2 to about 9:1, about 7:3 to about 9:1, about 3:1 to about 9:1, or about 4:1 to about 9:1.
[0032] As discussed above, methods of manufacturing battery separators are described herein. In particular, methods of manufacturing battery separators with reduced dust production are described herein. In some cases, the methods include mixing, such as in a low-temperature blender, polyethylene with the silica-rubber granule and a plasticizer to form a mixture. The mixture can then be heated above the melting point of the polyethylene and extruded through a sheet die. The resulting extruded sheet can then be processed and calendared in a variety of ways, as is known in the art, to form the finished battery separator. As discussed above, because the silica-rubber granule is inherently dust-formation suppressing, mixing polyethylene with the silica-rubber granule results in reduced dust production as compared to mixing polyethylene with silica particles and rubber particles.
[0033] In many cases, the polyethylene is an ultra-high molecular weight polyethylene powder. The plasticizer can be a process oil, such as a naphthenic process oil. Additives, such as carbon black, antioxidants, colorants, and lubricants, can be added at the time of mixing, if not already sufficiently included within the silica-rubber granules themselves.
[0034] As is known in the art, additional process oil may be added during the extrusion process. Additional rubber powder, separate from the silica-rubber granules, can be added downstream of the main mixing process.
[0035] Without wishing to be bound by theory, it is believed that during rubber compounding or battery separator extrusion, the silica-rubber granules are broken down due to the high shear energy involved in the processes. During the breakdown, the granules are transformed back into silica particles and rubber particles, likely having sizes of about 1 micron to about 100 microns. However, at that point in the processes, the materials are within the process equipment and dust is not liberated to the workplace surrounding the process equipment.
EXAMPLE 1
[0036] This example represents silica-rubber granules containing an 85/15 mixture, by weight, of precipitated silica and cross-linked rubber powder (Edge Rubber Co.) that were formed by mechanical compression in accordance with a dry granulation process. The uniformity of the rubber dispersion throughout the granule is observed in the optical micrographs at different magnifications shown in FIGS. 1A and 1B .
EXAMPLE 2
[0037] This example represents formation of a battery separator by an extrusion process. A mixture of ultra-high molecular-weight polyethylene (UHMWPE), silica-rubber granules formed as described in Example 1, and a naphthenic process oil was blended together and then fed into a 27 mm twin screw extruder. Additional oil was added at the throat of the extruder. The mixture was extruded at elevated temperature (about 215° C.) through a sheet die and into a calender roll stack, where a rib pattern was embossed on the sheet. The oil-filled sheet was then extracted, removing most of the process oil, to form a porous separator containing 65.3 wt. % silica, 11.5 wt. % rubber, and 23 wt. % UHMWPE. The separator had a backweb thickness of 0.33 mm and an overall rib height of 1.08 mm.
[0038] The uniformity of the rubber distribution is shown in the surface and cross-sectional optical micrographs in FIGS. 2A and 2B , respectively.
EXAMPLE 3
[0039] This example records data from tests performed on the porous separator formed in Example 2. A leachate solution was formed from the separator in Example 2 by adding 9.94 grams to 100 ml of H 2 SO 4 (s.g.=1.210) and then heating for 7 days at 70° C. The leachate was then cooled to room temperature, and electrochemical testing was performed with regard to antimony suppression, antimony selectivity, and hydrogen suppression.
[0040] FIG. 3 shows that the leachate had a moderate-to-strong suppression effect on H 2 evolution. Peak currents for charge and discharge waves are increased, but voltages were stable. Discharge capacity was only slightly increased.
[0041] FIG. 4 shows that the separator with the silica-rubber granules had a stronger antimony suppression effect than that of Edge Rubber rubber powder-containing separators tested. The effect is even stronger than that of some other Edge Rubber rubber powder samples/lots.
[0042] FIG. 5 shows that, in the antimony control test, higher current efficiency was achieved compared to conventional separators made with Edge Rubber rubber powder.
[0043] In summary, silica-rubber granules were used to produce a porous polyethylene separator sheet by an extrusion process. An even flow of extrudate was observed from the die, and uniform distribution of rubber particles was observed in the sheet. The resulting separator exhibited increased activity with respect to the reduction of hydrogen evolution. This performance was demonstrated by an ECC test, showing a strong decrease in hydrogen current; an AST showing a 1.31 selectivity value, which is higher than the 1.24 maximum selectivity value measured for any other separators made with Edge Rubber rubber powder; and an ACT, showing a 39.9% current efficiency, which is higher than the 32.5% maximum current efficiency measured for any other separators made with Edge Rubber rubber powder. These silica-rubber granules appear to offer potential performance benefits in the porous separator.
[0044] The following are prophetic examples of silica-rubber granule formation processes.
EXAMPLE 4
[0045] Silica-rubber granules are formed by spray-drying an aqueous dispersion of natural rubber latex and silica.
EXAMPLE 5
[0046] Silica-rubber granules are formed by precipitation of an aqueous or solvent dispersion of polymer/rubber powder/silica into a non-solvent for the polymer. A specific implementation of this example is polyvinyl alcohol, polyacrylamide, or polyvinylpyrolidone used as a water soluble polymer in an aqueous dispersion with rubber powder and silica. A droplet of this dispersion falling into methanol will cause these polymers to precipitate, and thereby hold together the rubber and silica. A drying process that removes the solvent leaves behind a granule.
[0047] Those having skill in the art will understand that many changes may be made to the details of the above-described embodiments without departing from the underlying principles of the invention. The scope of the present invention should, therefore, be determined only by the following claims. | Granules containing mixtures of silica powder and cross-linked rubber powder are used in the manufacture of battery separators or vehicle tires. A granule contains silica and rubber powders in proportional amounts that form a silica powder carrier within which rubber powder particles are distributed. Incorporating silica-rubber granules in the manufacturing process of polyethylene separators offers a way to limit water loss in and improve the cycle life of a deep cycle lead-acid battery. Incorporating silica-rubber granules in the manufacturing process of vehicle tires affords advantages including easier material handling, reduced production of dust, and reduction in the number of ingredients measured and added to the formulation. | 1 |
FIELD OF THE INVENTION
This invention relates to an engine oil pressure-operated system for starting and stopping of a compression-ignition internal combustion engine by moving a control member of a fuel injector pump of the engine respectively to a "run" position and a "stop" position, and/or for changing automatically from partial or complete decompression to complete compression of an internal combustion engine.
DESCRIPTION OF PRIOR ART
The prior art known to me comprises British Patent specifications Nos. 990, 072, 1,035,976, 1,068,607, 1,103,919, 1,109,387, 1,136,761, 1,237,842, 1,352,003 and 1,352,093.
SUMMARY OF THE INVENTION
As seen from one aspect of the invention, there is provided an engine oil pressure-operated system for starting and stopping of a compression-ignition internal combustion engine by moving a control member of a fuel-injector pump of the engine respectively to a "run" position and a "stop" position, comprising an oil pressure-operated device connected to the control member and operable by oil pressure from the engine to move the control member to the "run" position against a return spring which is operative in the absence or upon removal of oil pressure from said device to move the control member to the "stop" position, and valve means selectively operable firstly to supply oil pressure from the engine to said device and secondly to alternatively connect said device to drain.
Preferably said valve means is an electrically operable three-way solenoid valve.
Preferably the connection to drain is a connection to the engine sump.
If the engine is of a type adapted to be partially or completely decompressed during starting, said system may include a second oil pressure-operated device connected to a second control member and responsive to oil pressure via said valve means to move the second control member from a partial or complete decompression position to a complete compression position with a delay after the first-mentioned device has moved the first-mentioned control member to its "run" position.
Preferably a second return spring is operative to move the second control member to the partial or complete decompression position in the absence or upon removal of oil pressure from said second device.
As seen from another aspect of the invention, there is provided an engine oil pressure-operated system for changing automatically from partial or complete decompression to complete compression of an internal combustion engine, comprising an oil pressure operated piston-in-cylinder device connected to an engine compression-control member and arranged to be supplied with oil from the engine so as to be responsive to oil pressure from the engine to move the control member from a partial or complete decompression position to a complete compression position.
IN THE DRAWINGS
The single FIGURE is a partly sectioned drawing of a preferred form of engine oil pressure-operated system embodying both aspects of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawing, the illustrated system is adapted for use with a range of compression ignition internal combustion engines which are available from Petters Limited and which are known as the PH/PJ single and twin cylinder diesel engines. The illustrated system comprises a cylinder 1 containing a piston with an oil seal 2 and a return spring 3. An operating rod 4 is connected to the piston and extends movably through a hole 5a in a pivoted governor arm 5 to allow a speeder/governor spring 5b of the engine to move the governor arm 5 to a "run" position when the rod 4 has been extended out of the cylinder 1 in a manner to be described. The rod 4 is fitted with a lock-nut and washer assembly 4a for moving the arm 5 positively to a "stop" position when the rod 4 retracts into the cylinder in a manner to be described. The cylinder 1, piston-with-oil 2, return spring 3 and piston rod 4 are manufactured by Schrader Limited and are available as an assembly known as their Part No. 44828, one inch (1") diameter, neck mounted, suitable for use with oil. The governor arm 5 is part of the engine and forms a control member of one or two fuel injector pumps (not shown) of the engine--according to the number of cylinders--the arm 5 being movable to the "run" position and the "stop" position as desired. The cylinder 1 is arranged to be supplied with engine oil pressure via a three way solenoid valve 6 having three ports A, B, and C. The solenoid valve 6 is manufactured by Alpha Controls Limited to their type reference SIRAI, Ref. No. L 3332/5, 1/4" BSP (British Standard Pipe) entry ports (i.e., ports A and B in the drawing), 1/8" BSP vent port (i.e., port C) body orifice 3 millimeters, operating pressure 4.5 bar, suitable for use with oil. The valve 6, when energised electrically, opens port A to port B and closed port C. When the valve 6 is unenergised, port C is opened to port B while port A is closed. The oil pressure supply from the engine is connected to port A. Port B is connected to cylinder 1 whilst port C is connected to the crankcase, sump or lubricating oil tank of the engine (not shown).
A second cylinder 7 contains a second piston with an oil seal 8 and a return spring 9. An operating rod 10 is connected to the piston 8 and also to a second control arm 11. The cylinder 7 is connected by a pipe 12 to the port B of valve 6. The control arm 11 is also part of the engine and can be moved selectively to a "start" position to cause partial or complete decompression of the engine, by opening the exhaust valve or valves, to permit easy starting of the engine, or to a "run" position to apply complete compression to the engine. The cylinder 7, piston-with-oil seal 8, return spring 9 and operating rod 10 are manufactured by Schrader Limited to their Part No. 40410 AV, 1" diameter, trunnion mounted, suitable for use with oil.
When the arm 5 is rotated clockwise by movement of control rod 4 to the right as seen in the drawing, the supply of fuel from the injector pump to each cylinder of the compression-ignition engine is cut off, stopping the engine. Movement of the control rod 4 to the left enables spring 5b to rotate arm 5 counterclockwise and hence enables the injector pump to supply fuel to each engine cylinder.
Movement of operating rod 10 to the right, rotating arm 11 clockwise, causes the application of partial or complete decompression of the engine, by opening the exhaust valve or valves, to permit easy starting of the engine. Movement of operating rod 10 to the left, rotating arm 11 counterclockwise, applies complete compression to the engine.
Because of the provision of the pipe 12, when oil pressure is supplied by valve 6 to cylinders 1 and 7, movement of operating rod 4 to the left takes place before movement of rod 10 to the left, with the result that fuel is supplied to each engine cylinder, while partial or complete decompression is still applied to the engine.
In operation, the solenoid valve 6 is energised (by means not shown) simultaneously with operation of an electric starter motor (not shown) for cranking the engine. The solenoid valve 6 remains energised for as long as the engine is required to run. As the engine is motored or cranked on the starter motor, oil pressure builds up and feeds via port A through to port B and so to the cylinder 1. When the pressure is sufficient to overcome the force of the return spring 3, the piston 2 moves the operating rod 4 to the left and hence rotates the control arm 5 counterclockwise to the "run" position, enabling fuel to be supplied to each engine cylinder. Soon afterwards, the oil pressure causes the piston 8 to move the operating rod 10 to the left, rotating arm 11 counterclockwise to apply complete compression to the engine, to start the engine running.
When it is required to stop the engine, whether because of a fault or for any other reason, the valve 6 is de-energised, closing port A and opening port B to port C, so that piston 2 and operating rod 4 are moved to the right by the compression spring 3, rotating arm 5 clockwise to the "stop" position in which fuel supply to each engine cylinder from the injector pump is shut off. After a short delay, due to the restriction of pipe 12, the compression spring 9 moves the piston 8 and the operating rod 10 to the right, rotating arm 11 clockwise to its "start" position, in which partial or complete decompression is applied to the engine in readiness for the next time of starting of the engine.
The system provides protection against loss of oil pressure, since failure of the oil pressure supply will result in the spring 3 moving piston 2 and rod 4 to the right, rotating arm 5 clockwise and shutting off the fuel supply. Similarly, the engine cannot be started unless it has sufficient oil to provide the necessary oil pressure to move both pistons 2 and 8 and operating rods 4 and 10 to the left.
In a modification for use with a compression ignition engine not requiring partial or complete decompression for starting, the cylinder 7, piston 8, spring 9, operating rod 10, arm 11 and pipe 12 may be omitted, provided that the connection of the pipe 12 to the cylinder 1 is closed off in order to avoid loss of oil.
In another modification, the cylinder 7, piston 8, spring 9, operating rod 10 and arm 11 can be used without the cylinder 1, piston 2, spring 3, operating rod 4, arm 5 and valve 6, by connecting the pipe 12 directly to the oil pressure supply. In this case, when cranking the engine by hand, the spring 9 causes the engine initially to be partially or completely decompressed. Then, during cranking, the oil pressure builds up so as automatically to move piston 8 and rod 10 to the left, rotating arm 11 counter-clockwise to apply complete compression to the engine, to start the engine running. Other compression ignition internal combustion engines may require a different cylinder diameter and/or piston stroke for operating the fuel pump control member and/or the compression control member if provided, or even a different solenoid valve.
It is a matter of choice, how long a time delay is required after moving arm 5 to "run" before moving arm 11 to "run". | For starting a compression-ignition internal combustion engine, a solenoid valve is electrically energized simultaneously with the starter motor (the valve remaining electrically energized while the engine afterwards continues to run) to supply oil pressure from the engine oil pump to a first piston-in-cylinder device to move a fuel injection pump lever from "stop" to "run" against a first return spring, so that fuel supply always (even when starting) depends upon adequate oil pressure. A second piston-in-cylinder device with a second return spring is responsive after a delay to the oil pressure to change the engine from at least partial decompression to full compression. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method for coating textile substrates such as carpets and textile fabrics with an improved latex-containing coating composition.
2. Description of the Prior Art
In the manufacture of coated textile substrates such as tufted carpets, a liquid coating composition containing latex normally is applied to the back of the carpet and the resulting laminate is heated in an oven to dry the backing layer and bond it to the carpet. The latex backing serves to lock the tufts into the carpet substrate, and to provide adhesions for the jute or foam layer which can be laminated to the back of the carpet. The latex backing layer also imparts to the carpet the desired hand characteristics, adds dimensional stability, adds weight to the carpet, acts to promote fire retardancy, and fills in the space between the stitches. One latex coating can comprise the total backing operation in some cases. If a secondary foam layer is applied, a latex composition similar to the undercoat composition may be employed.
Latex carpet backing compositions are presently formulated on the basis of 100 parts by weight of dry latex. Included in the standard formulations are up to 800 parts of filler. Prior art attempts to reduce the cost of these latex coating compositions in the carpet backing and fabric coating industries has almost always involved the use of increased amounts of filler. There also have been some attempts to extend (i.e., replace a portion of) the latex solids with starches, hydrocarbon oils and waxes. These prior art extenders suffer from the drawbacks of decreasing the fire retardancy of the article thus requiring increased amounts of fire retardants such as aluminum trihydrate (a filler), phosphates, borates, halogens, antimony oxidex and the like. This increase in fire retardant offsets any cost advantage from extending the latex with the prior art extenders.
Thus, it would be of great value and represent significant monetary savings if a latex extender could be found which does not adversely effect the properties of the latice including, inter alia, fire retardancy. Moreover, since most latex solids are petroleum based products, a significant reduction in utilization of these increasingly scarce materials will have an obvious beneficial impact on our natural resource picture.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide an improved method for coating a textile substrate which does not suffer from the drawbacks of the prior art.
More specifically, it is an object of the present invention to provide a method for coating textile substrates in which the latex in the coating system is extended with a low cost additive which does not adversely effect the latice properties.
It is also an object of the present invention to provide a method for coating a textile substrate in which the latex extender imparts increased flame retardancy to the article.
Another object of the present invention is to provide a method for coating a textile substrate in which the extended latex coating is more stable and can be applied to the substrate more uniformly.
It is another object of the present invention to provide an improved carpet coating method in which the adhesion strength of the dried latex coating to the carpet tufts and any secondary backing layers is as good or better than an unextended latex formulation.
Still another object of the present invention is to provide a carpet or textile article which contains an extended latex coating having the abovedescribed characteristics.
In accordance with these and other objectives the present invention comprises an improvement in the process of the steps applying a latex-based composition to a textile substrate and heating to dry the composition and bond it to the substrate, the improvement comprising formulating the latex-based composition by replacing from about 5 to about 40 parts by weight of the latex normally present in the composition based on 100 parts dry latex solids with an alkali metal silicate extender, and further adding to the composition a latex compatible metal compound which will react in situ with the silicate extender during the drying step to render the silicate extender less water soluble.
The present invention also comprises a laminated article comprising a textile substrate having bonded thereto a dried latex-based coating layer said coating layer being formed as described above.
Surprisingly, the silicate extending latex coating composition employed in the process of the present invention is more stable and better dispersed than the straight latex formulation. The pH of the latex dispersion employed in the process of the present invention is higher than that of the conventional latex system and this results in easier application and a more smooth and level coating on the carpet or textile substrate.
DESCRIPTION OF THE INVENTION
The present invention relates to a method for coating textile substrates such as carpets and textile fabrics with a latex based backing layer. While specific reference herein will be made to backings for tufted carpets, it will be recognized by one of ordinary skill in the art that the coating systems of the present invention have general utility in all types of carpet and coated textile applications.
By latex, applicant intends to refer to both natural and synthetic latexes. Included among commonly employed synthetic latexes are aqueous dispersions of polystyrene, styrene butadiene copolymer (SBR) carboxylated SBR's, neoprene, polyvinyl chloride, polyvinyl acetate, acrylonitrile copolymers, acrylic polymers and copolymers and the like.
In the formulation of a latice compound the basis is taken as 100 parts by weight of dry latex. The conventional latex latice also contains about 100-800 parts of filter. Normally these fillers comprise alumina trihydrate, which has fire retardant properties, calcium carbonate (called whiting) and clay. In addition to fillers the conventional latice also contains from about 0.5-2.0 dry parts of a thickener (e.g., sodium polyacrylate) to control viscosity and about 1 to 10 dry parts of specialty components such as soaps, color additives, stabilizers, accelerators, and the like. In the process of the invention the conventional latex, filler, thickener and specialty materials may be employed as desired.
The present invention is based on the surprising discovery that the latex component of the carpet or textile coating composition can be replaced in the conventional formulation by from about 5 to 40% by weight of an alkali metal silicate. In the extended latex formulations according to the present invention the sum of the latex and silicate extender remain 100 parts in the conventional formulation. Preferred silicate amounts are in the range of from about 15 to 25 parts by weight. Most preferred are silicate amounts of about 20 parts by weight.
The alkali metal silicates useful in the process of the present invention include the silicates of lithium, sodium, potassium, rubidium and cesium. Preferred are the silicates of sodium and potassium or mixtures thereof. Included in the sodium silicates are the "water glass" compositions which vary in formula from about Na 2 O.3.75 SiO 2 to 2 Na 2 O.SiO 2 . Other useful sodium silicate salts include sodium metasilicate anhydrous sodium metasilicate pentahydrate, sodium sesquisilicate, sodium orthosilicate and the like. Exemplary of similar potassium salts are K 2 Si 4 O 9 , K 2 SiO 3 and K 2 Si 2 O 5 .
In the prior art the above-described silicates have been employed as fire retardants in various materials such as wall board, paper, adhesives, and latex resin systems including paints. The solubility characteristics, the high fusion temperature required and moisture regain causing loss of adhesion have taught away from the inclusion of silicates in carpet backing applications.
In addition to the silicate extender, the coating composition employed in the present invention should also contain a latex compatible metal compound which reacts with the silicate to form a less water soluble product. While not wishing to be bound by any particular theory, applicant believes that the metal compounds useful in the present invention react with soluble silicate salts to form less soluble silica gels. Any metal compound which can be incorporated in a latex system without adversely affecting the system stability or other properties, and which will react with the silicate to decrease its water solubility can be employed. Preferred are oxygen containing metal salts and metal oxides.
Among the preferred reactive metal compounds are calcium carbonate, clay, zinc oxide, trisodium phosphate and tetra sodium (or potassium) pyrophosphate. The latex-based coating composition employed in the method of the present invention can be formulated in the conventional manner by simply mixing together the ingredients (i.e., latex, extender, fillers, metal reactants, etc.) at room temperature. The silicate reactive metal compounds employed generally react very slowly, if at all, under ambient temperatures and, therefore, the inclusion of these compounds in the latex coating composition can be effected prior to the actual coating process without adversely affecting the coating composition stability. After application the latex based coating composition is dried by heating the coated substrate. During the heating step the metal compounds react with the silicate extender to render the latter less water soluble.
The amount of reactive metal compound employed depends on how reactive the compound is towards the silicate and how well the latex system will tolerate the compound. One skilled in the art can readily determine the useful range of additions for various metal compounds based on these criteria. By way of example, calcium carbonate is only moderately reactive with silicates and is relatively inert in latex systems. Therefore, amounts of about 50 to 800 parts by weight based on 100 parts latex plus silicate may be employed. Zinc oxide, on the other hand, is much more reactive and much less tolerable in latex systems. Zinc oxide additions, therefore, should be in the range of about 3 to 10 parts. Similarly, trisodium phosphate and tetra sodium (or potassium) pyrophosphate can be added in amounts of from about 3 to 10 parts. Clay is possibly one of the most reactive with silicates in the presence of heat if used in an amount of about 20 to 200 parts based on 100 parts latex plus silicate.
In the process of the present invention a coating of the aqueous extended latex dispersion described above is applied to the back of a carpet or textile substrate. This is preferably performed by conventional "lick-rolling" techniques whereby the carpet or fabric is continuously fed over a rotating applicator (lick-roller) which is rotating in a trough of latex. A doctor blade downstream from the trough scrapes or wipes the coating to the proper thickness. Any other conventional coating processes, of course, may be employed. As is customary in the carpet industry the primary back coat or precoat is preferably applied to the coat at a rate of about 18-34 ounces per square yard (dry solids).
After the precoat is applied the coated substrate is continuously forwarded to drying ovens. Drying temperatures of about 200°-375° F. are normally employed. Dryer residence time will generally depend on the weight of the backing compound applied, the type of compound applied and the dryer efficiency.
The product produced by the process of the present invention is a backed carpet or coated fabric having a portion of the latex in the coating replaced with the above-described in situ reacted silicate extender. The article containing this improved cured latex composition is significantly lower in cost and possesses strength, adhesion and fire retardancy characteristics at least as good as conventional materials. Moreover, the article produced according to the present invention exhibits better hand characteristics. In addition, the replacement of high smoke yielding hydrocarbons with the non-smoking inorganic extender of the present invention results in a safer consumer product.
The following examples are included for illustrative purposes only and are not intended to limit the scope of the invention.
EXAMPLE 1
This example shows a conventional precoat formulation normally employed to back coat a tufted carpet. The following ingredients were mixed together at room temperature in a tank equipped with an agitator.
______________________________________Ingredient Dry Weight % Solids Wet Weight______________________________________Latex (carboxylatedstyrene butadiene) 100 48.0 208.33Water -- -- 126.04Whiting (CaCO.sub.3) 475 100 475.00Aluminum Hydrate(Al.sub.2 (OH).sub.3) 75 100 75.00Thickener 0.70 10 7.00TOTALS 650.70 891.37______________________________________
The resulting dispersion had a solids content of 73%, a viscosity of 60-65 cp (Brookfield RVF 5 at 20), and a weight of 14.0±.2 lbs./gal. The cost per dry pound of the formulation was $.0720.
The coating formulation was applied as a precoat to a tufted carpet back by lick rolling techniques resulting in an application rate of about 16-22 ozs./sq.yd. The coated carpet was continuously fed through a drying oven at a rate of about 25 ft./min. and a drying temperature of about 270°-285° F.
EXAMPLE 2
This example shows the process of the present invention employing a silicate extender and CaCO 3 as the reactive compound. The procedure of Example 1 was repeated except that the following information was employed:
______________________________________Ingredient Dry Weight % Solids Wet Weight______________________________________Latex 80 48 166.67Water -- -- 127.70Sodium Metasilicate 20 50 40.00 pentahydrateWhiting (CaCO.sub.3) 550 100 550.00Thickener 0.70 10 7.00TOTALS 650.70 891.37______________________________________
The resulting dispersion had the following properties:
Solids: 73%
Viscosity: 60-65 cp.
lbs./gal.: 14±.5
Cost/dry lb.: 0.621
EXAMPLE 3
This Example shows the process of the present invention employing a silicate extender and ZnO as the reactive metal compound. The procedure of Example 1 was repeated except that the following formulation was employed:
______________________________________Ingredient Dry Weight % Solids Wet Weight______________________________________Latex 80.00 48 166.67Water -- 125.18Sodium Metasilicate 20.00 50 40.00 pentahydrateZinc Oxide 4.00 50 8.00Aluminum hydrate 550.00 100 550.00Thickener .70 10 7.00TOTALS 654.70 896.85______________________________________
Properties were as follows:
Solids: 73%
Viscosity: 60-65 cp
EXAMPLE 4
This Example shows the process of the present invention employing a silicate extender and tetra sodium pyrophosphate as the reactive metal compound. The procedure of Example 1 was repeated except that the following formulation was employed:
______________________________________Ingredient Dry Weight % Solids Wet Weight______________________________________Latex 80.00 48 166.67Water -- -- 101.81Sodium Metasilicate 20.00 50 40.00 pentahydrateTSPP 3.00 100 30.00Aluminum hydrate 550.00 10 550.00Thickener .70 7.00TOTALS 653.70 895.48______________________________________ | The method for coating textile substrates such as carpets and textile fabrics with a latex backing is improved by replacing up to about 40% by weight of the normally employed latex solids in the coating composition with an alkali metal silicate extender such as sodium silicate, and further adding a latex compatible metal compound which will react with the silicate extender to render the silicate values less water soluble. The improved backing layer provides a significant cost reduction, increased fire retardancy and beneficial modification of other properties of the coated substrate. | 8 |
FIELD OF THE INVENTION
The present invention relates to an internal combustion engine especially useful for automobiles. This internal combustion engine produces exhaust gases with reduced noxious gas content. Oxides of nitrogen are reduced. Furthermore, the rate of fuel consumption is improved.
DESCRIPTION OF THE PRIOR ART
At the present time, there is a great demand for internal combustion engines for automobiles which emit clean exhaust gas having a reduced amount of oxides of nitrogen but which internal combustion engines also have a desirably low rate of fuel consumption. Exhaust gas recirculation (EGR) and lean combustion are frequently provided in such engines. It is known that increasing the burning velocity will tend to prevent combustion fluctuations and will tend to prevent misfiring in engines equipped with exhaust gas recirculation which also employ lean combustion.
In order to increase the burning velocity, there has been recently proposed several suction systems in which a sub-suction path is provided separately from the main suction path. The sub-suction path injects a gas into the combustion chamber, thereby generating a swirl of the gases in the combustion chamber.
However, internal combustion engines having such a sub-suction path are not presently satisfactory.
SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to provide an improved internal combustion engine having a sub-suction path substantially free of the problems of prior engines.
Another object is to provide an improved internal combustion engine substantially free of misfiring during deceleration.
Another object of the present invention is to provide an improved internal combustion engine producing exhaust gas having a reduced hydrocarbon content.
Yet another object of the present invention is to provide an improved internal combustion engine producing exhaust gases having a reduced content of oxides of nitrogen.
Yet another object of the present invention is to provide an internal combustion engine in which the air-fuel ratio can be finely controlled.
Still another object of the present invention is to provide an improved internal combustion engine which is substantially free of misfiring during deceleration at low running rates and at intermediate running rates when such engine is equipped with exhaust gas recirculation.
The above and other objects are accomplished according to the present invention by providing an internal combustion engine comprising a combustion chamber, a fuel supply device, a main suction path, and a sub-suction path. The combustion chamber has a suction valve and a piston operable to make a suction stroke. The fuel supply device has a draft passage comprising an air-metering portion and a throttle valve downstream of the air-metering portion. The main suction path connects the fuel supply device with the combustion chamber. The sub-suction path is separate from the main suction path and comprises a downstream portion as well as first and second upstream portions. The outlet of the downstream portion creates a swirl of gases in the combustion chamber. The inlet of the downstream portion is in fluid communication with the outlet of the first upstream portion. It is also in fluid communication with the outlet of the second upstream portion. The inlet of the first upstream portion is in fluid communication with the draft passage at a point between its air-metering portion and its throttle valve. The inlet of the second upstream branch is vented to the atmosphere. The second upstream branch has a vacuum operated valve responsive to the vacuum in the main suction path at a point downstream of the throttle valve. In the engine of the present invention, the gas to be introduced into the sub-suction path is solely made to flow through the air-metering portion of the fuel supply device during operations other than deceleration. In this manner, a finely controlled air-fuel ratio can be attained. During deceleration, on the other hand, the gas is sucked directly from the atmosphere such that misfiring is reliably prevented.
BRIEF DESCRIPTION OF THE DRAWING
The single figure of the drawing is a sectional view showing significant elements of the internal combustion engine of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the single figure of the drawing, there is shown an internal combustion engine of the present invention. The internal combustion engine has a cylinder 1 attached to a cylinder head 2 having a piston 3 operable therein. The cylinder 1, cylinder head 2 and piston 3 define a combustion chamber 4 into which a main suction path is opened. The main suction path 5 has a serial passage which leads from a suction port 6 formed in the cylinder head 2 via a suction manifold 7 and a carburetor 8. The carburetor 8 constitutes a fuel supply device. An air cleaner 9 is mounted on the carburetor 8. The suction port 6 is oriented in a direction to generate a swirl of gases in the combustion chamber 4. This swirl of gases turns centering around the axis of the cylinder 1. The swirling direction is predetermined such that the air-fuel mixture supplied from the suction port 6 will flow into an exhaust port 10 after it has swept an ignition plug (not shown). The ports 6 and 10 are opened or closed by the actions of a suction valve 11 and an exhaust valve 12 respectively. The valves 11 and 12 are opened and closed by the action of an opening control mechanism. The opening control mechanism comprises return springs 13 and 14, cams 16 and 17, driven by a camshaft 15 as well as rocker arms 18 and 19. The valves 11 and 12 are seated upon their respective valve seats 20 and 21 when the valves are closed.
The sub-suction path 22 has a smaller effective opening area than does the main suction path 5. The outlet of the sub-suction path 22 constitutes a pipe 23. The extreme outlet of the pipe 23 is in the form of an injection nozzle. The pipe 23 is embedded in the cylinder head 2. The sub-suction path 22 can be divided into a single downstream portion 24 and two upstream portions 24a and 24b. The inlet of the downstream portion 24 is coincidental with the outlets of the first upstream portion 24a and the second upstream portion 24b.
The first upstream portion 24a forms a part of the passage of the carburetor-line path and may act as a fuel supply device. The second upstream portion 24b forms a part of the atmosphere line path. The first upstream portion 24a comprises a path 25 which is formed in the body 8a of the carburetor 8. The path 25 itself is divided midway into two branches which open into the carburetor. The first such branch is designated an upstream portion 25a whereas the second branch is designated as a downstream portion 25b. Both open into the draft passage 8b of the carburetor 8. The inlets 25a and 25b are spaced from each other in the flow direction of the draft passage 8b such that the upstream inlet 25a is always open between the venturi 8c and the throttle valve 8d. On the other hand, the downstream inlet 25b is opened and closed by the throttle valve 8d.
The second upstream portion 24b is itself branched and is connected to the air cleaner 9. In other words, it is vented to the atmosphere since the path 26 bypasses both the venturi 8c and the throttle 8d of the carburetor 8. The atmospheric vent of the second portion 24b is designated 26'. A vacuum operated valve 27 is located in the second upstream portion 24b. The valve 27 divides the second upstream portion 24b into an upstream porton 26a and a downstream portion 26b. The vacuum operated valve 27 has a vacuum chamber 27b which is defined by a diaphram 27a. The vacuum chamber 27b is in fluid communication with a vacuum signal line 28, the inlet of which is in fluid communication with the main suction path 5 at a point downstream of the throttle valve 8d. The vacuum valve 27 is normally closed by the action of a return spring 27c. The vacuum valve 27 is opened when the diaphram 27a compresses the return spring 27c. This action occurs when the vacuum in the vacuum chamber 27b is increased. The degree of vacuum required to open the vacuum operated valve 27 is set equal to the vacuum generated in the main suction path 5 during deceleration.
When the vacuum operated valve 27 is opened, the path 26, i.e., the path 26a, is supplied with fuel in the form of an air-fuel mixture. The float chamber 8e of the carburetor 8 is connected via a fuel-supply path 29 to the path 26a.
The fuel supply path 29 and the air cleaner 9 are connected via an air supply path 30. The system is provided with three jets 31, 32, 33. The jet 31 meters the fuel coming from the float chamber 8e. The jet 32 meters the air from the path 30. The jet 33 meters the air-fuel mixture as has its air-fuel ratio set at a predetermined value by the coactions of the two jets 31 and 32.
Exhaust gas is recirculated from the exhaust system via an EGR valve into the main suction path 5. However, since the construction of that portion of the system is similar to that of the prior art, it is unnecessary for an understanding of the present invention and it is therefore omitted from the drawing.
The engine of the present invention functions as follows.
First of all, in low-and intermediate-load running ranges, the throttle valve 8d has a relatively small opening. Since, under such conditions, the vacuum in the suction manifold 7 is sufficiently lower than that during deceleration, the vacuum-operated valve 27 is closed. During the suction stroke, on the other hand, since the pressure differential between the outlet end 23 of the sub-suction path 22 and the carburetor-line inlet ends 25a, 25b becomes remarkably high, the gas is injected at a remarkably high velocity from the sub-suction path 22 into the combustion chamber 4 so that an intense swirl of the suction gas is generated in the combustion chamber 4. As a result, the burning velocity is accelerated so that lean combustion can be stably sustained even with a high exhaust gas recirculation rate.
Second, during the idling operation, since one carburetor-line inlet end 25b is closed by the throttle valve 8d, the gas is sucked only from the other inlet end 25a into the sub-suction path 22 so that the gas injection rate from said sub-suction path 22 is reduced. During idling, since fuel is supplied from the carburetor 8 solely through idle port 8f, a low gas injection rate is preferred.
Third, during the deceleration, since the engine is running at a high speed with the throttle valve 8d closed, the vacuum in the suction manifold 7 is so great that the vacuum-operated valve 27 is opened. The gas is then sucked into the sub-suction path 22 not only from the inlet 25a but also from the atmosphere-line inlet 26' so that the gas injection rate from said sub-suction path 22 into the combustion chamber 4 is increased. Thus, it is possible to prevent misfiring which is otherwise prone to take place during deceleration. Furthermore, the hydrocarbon content of the exhaust gas is reduced. In order to further inhibit misfiring during deceleration, it is preferred that the fuel or an air-fuel mixture be supplied to the atmosphere-line path 26. Taking the improvement in the rate of fuel consumption into consideration, it is also possible to cut off the fuel supply to the atmosphere-line path 26.
In the running ranges other than deceleration, since the flow rate of the air to be sucked into the combustion chamber 4 is wholly metered through the venturi 8c, a proper air-fuel ratio is preferably realized.
Although the foregoing description refers to a preferred embodiment, the present invention should not be limited thereto but can include the following modifications:
First, the outlet of the sub-suction path may open directly into the combustion chamber, and an opening control valve, opened during the suction stroke, can be separately provided in the sub-suction path.
Second, the sub-suction path may be formed with either of the carburetor-line inlet ends 25a and 25b.
Third, the present invention can also be used with multi-or single-cylinder engines which are not equipped with a suction manifold.
Fourth, the atmosphere-line inlet of the sub-suction path may be connected to either the inside of the draft passage of the carburetor upstream of the venturi or to an auxiliary air cleaner which is provided separately and indepehdently of the carburetor air cleaner.
Fifth, the carburetor can be of two-barrel type, and in this case the carburetor-line path of the sub-suction path can be opened into the primary draft passage of the two-barrell carburetor.
Sixth, the fuel supply device can be something other than a carburetor such as an electronically controlled fuel injection device. In other words, the fuel supply device-line path of the sub-suction path may be opened between an air flow meter acting as the air metering portion of the injection type fuel supply device and the throttle valve disposed downstream thereof.
Still other modifications will be apparent to those of ordinary skill in the art without departing from the spirit of the invention as described above and as claimed below. | An internal combustion engine, which is equipped with a sub-suction path for generating a swirl of the suction gas in the combustion chamber in addition to a main suction path to be opened or closed by a suction valve. The sub-suction path is equipped at its inlet side paths with two fuel supply device-line and atmosphere-line paths, the former of which is opened into the draft passage of a fuel supply device and between the air metering portion of said fuel supply device and a throttle valve downstream of the air metering portion and the latter of which is vented to the atmosphere while bypassing said air metering portion and said throttle valve. With the aforementioned atmosphere-line path, moreover, there is connected a vacuum-operated valve which is made operable in accordance with the vacuum prevailing downstream of said throttle valve. | 5 |
FIELD OF THE INVENTION
[0001] The invention relates in general to channel coding and decoding techniques, and in particular, to blocks oriented codes, such as turbo-codes or LDPC codes, for example.
BACKGROUND OF THE INVENTION
[0002] Channel coding is a very important component in wireless communication systems like UMTS, WLAN (Wireless Local Area Network) and WPAN (Wireless Personal Area Network). In packet based transmission systems like WLAN and WPAN, as well as mobile radio systems (UMTS, HSDPA), the latency of the used channel decoder is of major importance. The latency of a decoder, or the decoding latency, is the time between the reception of the last bit of a block to be decoded and the output of the first result bit, i.e., after decoding.
[0003] In mobile radio, the reduction of latency can simplify the implementation complexity and the packet operation of the systems. In WLAN or WPAN systems, latency is an important parameter which has to be taken into account to ensure the functionality of the higher layers (MAC layer and above) and the efficient use of the spectrum resource by reducing the idle times.
[0004] FIG. 1 illustrates a stop-and-wait protocol in IEEE 802.11 WLAN systems, which is an error free case. More precisely, a typical situation in an 802.11 type of protocol based on CSMA-CA multiple access method is depicted. The source TX is sending a data block of length N at position 1 . The destination RX receives the data block after the transmission delay at position 2 . After the end of the data block reception at position 3 , the TX destination sends out an acknowledgement ACK at position 4 . This acknowledgement signal needs to be received by the RX source after an SIFS interval (Short InterFrame Space) at position 5 . In the 802.11a standard this SIFS interval is equal to 16 microseconds.
[0005] In a block based channel decoder, the decoding process can only start after the reception of the last bit in the block. Thus, the decoder needs to be very much overdimensioned in order to fulfill the timing requirements given by the standard. Thus, the channel coding of choice are convolutional coding schemes, which can already start the decoding with the first received bit. In this case, the available decoding time is much longer than in a block code case, especially when only small or no channel interleaving schemes are used.
[0006] Turbo-codes are other types of coding schemes which offer very good performance. However, due to the iterative structure of the decoder, the decoding latency is greater than the decoding latency of a convolutional code. Further, in case of turbo codes, larger blocks are better for the performance and the throughput, but lead to a higher latency.
[0007] For all these reasons, the latency problem of the turbo code decoder has generally prevented the use of this class of channel codes in the packet domain like the WLAN standard 802.11a/b/g. Consequently, in existing systems using packet transmission, either no coding or convolutional coders are generally used.
[0008] U.S. published patent application no. 2002/0194555A1 teaches that a reduction in the latency time can be obtained by reducing the size of the block at the cost of a correlative reduction in the performance of the system. European patent no. 1,337,063 teaches an analysis of a quality of service (QoS) for performing an equal segmentation of a frame to be turbo-code encoded to obtain an optimal length of the sub-frames.
[0009] However, as indicated above, such a length reduction is not compatible with good performance and throughput for turbo codes, but also more generally for blocks oriented codes, including also Low Density Parity Check codes (LDPC codes), for example.
SUMMARY OF THE INVENTION
[0010] An object of the invention is to reduce the latency of a blocks oriented code decoder, such as a a turbo-code decoder, for example, in order to adapt it to the actual needs of a specific application while maintaining good decoding and communication performance.
[0011] Another object of the invention is to permit the use of turbo code in the field of packet based transmission systems, like WLAN and WPAN systems, or in Digital Subscriber Line systems, like ADSL, VDSL or more generally xDSL, while controlling the turbo-code decoding latency and maintaining the performance needs.
[0012] According to one aspect, a method of encoding blocks of data with a blocks oriented code is provided. For example, depending on the application and/or the kind of data (control data, application data . . . ), the size of the block of data can be different and/or the required decoding latency can be different.
[0013] The method comprises receiving a block of data to be encoded, and
[0014] a) if the size of the block is consistent with a desired decoding latency, encoding the block of data, and
[0015] b) if the size of the block is not consistent with the desired turbo-code decoding latency, then nonequally splitting the block of data in a set of several sub-blocks to be sequentially and successively encoded with the blocks oriented code. The last sub-block to be encoded has a last sub-block size consistent with a decoding latency equal to or being the closest to the desired decoding latency and at least another sub-block having the greatest sub-block size. The greatest sub-block size is consistent with a given turbo-code decoding speed.
[0016] The method further comprises sequentially and successively encoding the sub-blocks of the set.
[0017] According to another aspect, a method of decoding a received block of data encoded with a blocks oriented code is provided. The method comprises receiving a control information indicating whether or not the received encoded block of data comprises a sequence of several encoded sub-blocks in which the last sub-block to be decoded has a chosen sub-block size consistent with a decoding latency equal to or being the closest to a desired decoding latency and at least another sub-block has the greatest sub-block size.
[0018] Depending on the control information, the method may comprise decoding the block of data as a whole, or sequentially and successively decoding the encoded sub-blocks. The decoding of each encoded sub-block begins at the end of the reception of the encoded sub-block.
[0019] In other words, if for example the length of the block of data to be encoded leads to a latency decoding which is consistent with the needs of the application, or if the data contained in the block of data are latency non-restricted data, then the block of data is encoded without any preprocessing.
[0020] However, if for example the data of the block are latency-restricted data and if the decoding of the block of data would lead to latency which is not consistent with the needs of the application, for example with the duration of the SIFS interval, a preprocessing is applied to the block of data. More precisely, such a large block is nonequally segmented into smaller sub-blocks. The latency is for example defined by the latency of the last block decoding. The larger sub-blocks permit one to maintain good performance decoding and are also better for the overall throughput, provided of course that the decoder can decode the blocks fast enough, so that at the end of the reception of sub-block N+1, sub-block N is decoded and the decoder is available. Accordingly, the greatest size of sub-block of the set of sub-blocks needs to be consistent with the decoding speed of the decoder. Consequently, with the nonequal segmentation according to these aspects of the invention, the latency can be controlled and satisfy the requirement of the specific application, whereas good communication performance are maintained.
[0021] In a typical case of a turbo-code a broad range of blocks sizes are defined. For example in the UMTS systems blocks sizes of 40 to 5114 bits with a one bit resolution are defined. Thus, it is generally possible to choose the size of the last sub-block in order to have a decoding latency equal to the desired latency.
[0022] However, the method is not limited to turbo-code, and the use of other blocks oriented codes is possible. For example codes like LUPC codes, BCH codes, Reed-Solomon codes, Reed-Muller codes, etc. can be used.
[0023] For LDPC codes the possible block sizes which can be used are given by the used architecture. Preferably, for a given efficient architecture only a limited set of sizes can be easily implemented. For example, in the case of WIMAX (IEEE 80.216e standard) 19 different block sizes are defined. For DVB-S2 LDPC codes, 9 different block sizes are defined.
[0024] In the turbo code case it is also possible to restrict the block sizes to a limited set (as for example around 20 different sizes for CDMA 2000). Thus, depending on the type of blocks oriented code used and/or the type of application or standard, the sizes of the sub-blocks may be chosen within a set of predefined sizes.
[0025] In such a case, if it is not possible to choose among the set of predefined sizes, a size of the last sub-block leading to the desired latency, the sub-block size of the last sub-block is chosen in the set to be consistent with a decoding latency which is the closest to the desired latency.
[0026] It is not mandatory for the largest sub-block to be the first sub-block to be encoded and decoded. For example, the first sub-block of the set can be a small control block.
[0027] Further, the set of sub-blocks could comprise large sub-blocks each having the same largest size followed by a last sub-block of a smaller size for being consistent with a latency equal to or being the closest to a desired latency. However, a simple way for implementing the nonequal splitting is obtained with sizes of the sub-blocks decreasing from the first sub-block to be encoded to the last sub-block to be encoded.
[0028] Preferably, the set of sub-blocks comprises a sub-set of sub-blocks in which the respective sizes of the sub-blocks decrease monotonically from the first sub-block of the sub-set to be encoded to the last sub-block of the sub-set to be encoded. The first sub-block of the sub-set has the greatest size. The size of a current sub-block of the sub-set being is half of the size of the preceding sub-block of the sub-set.
[0029] According to one embodiment in which the blocks oriented code is turbo code the encoding method further comprises
[0030] a) adapting the interleaving pattern associated to the turbo-code encoding to the size of the block, if the size of the block is consistent with a desired turbo-code decoding latency, and
[0031] b) respectively adapting the interleaving pattern associated to the turbo-code encoding to the size of the successive sub-blocks, if the size of the block is not consistent with the desired turbo-code decoding latency.
[0032] According to another embodiment still related to turbo-code, the decoding method further comprises depending on the control information, turbo-code decoding the block of data as a whole while adapting the interleaving and de-interleaving pattern associated to the turbo-code decoding to the size of the received block, or sequentially and successively turbo-code decoding the encoded sub-blocks while respectively adapting the interleaving and de-interleaving pattern associated to the turbo-code decoding to the size of the successive sub-blocks.
[0033] In other words, if for example the length of the block of data to be encoded leads to a latency decoding which is consistent with the needs of the application, or if the data contained in the block of data are latency non-restricted data, the block of data is turbo encoded without any preprocessing, while the interleaving and de-interleaving patterns of the turbo encoding means and turbo decoding means are adapted to the actual length of the block of data.
[0034] Another important feature of these embodiments includes adapting the interleaving and de-interleaving patterns associated to the turbo-code encoding and turbo-code decoding to the size of each sub-block resulting from the nonequal segmentation of the block.
[0035] The control of the turbo decoding latency may further comprise an adaptation of the number of iterations performed during turbo-code decoding. When the block of data to be encoded comprises an initial CRC word, in case b) above, a CRC word is calculated from the data decoded in all the sub-blocks and the calculated CRC word is compared with the initial CRC word after having decoded the last encoded sub-block.
[0036] In a particular but non-limiting application, the encoded blocks of data are transmitted through a wireless data communication system of the WPAN or WLAN type, or through a wireless data communication system like an UMTS mobile radio system.
[0037] According to another aspect, an apparatus adapted to encode blocks of data with a blocks oriented code comprises an encoding device having a main input adapted to receive a block of data to be encoded, and a splitter having a splitter input, and a splitter output. The splitter is adapted to split a block of data into a set of sub-blocks in which the last sub-block to be encoded has a last sub-block size consistent with a decoding latency equal to or being the closest to a desired decoding latency and at least another sub-block has the greatest sub-block size. The greatest sub-block size is consistent with a given decoding speed. The splitter output is adapted to sequentially deliver the sub-blocks.
[0038] A blocks oriented code encoder has an encoder data input, encoding means, and an encoder control input adapted to receive an information representative of the size of the block of data to be encoded. Global control means are adapted to receive control information and to either couple the splitter input to the main input and the encoder data input to the splitter output, or couple the encoder data input to the main input, depending on the control information.
[0039] The sizes of the sub-blocks may decrease from the first sub-block to be encoded to the last sub-block to be encoded.
[0040] Preferably, the set of sub-blocks comprises a sub-set of sub-blocks in which the respective sizes of the sub-blocks decrease monotonically from the first sub-block of the sub-set to be encoded to the last sub-block of the sub-set to be encoded. The first sub-block of the sub-set has the greatest size, and the size of a current sub-block of the sub-set is half of the size of the preceding sub-block of the sub-set.
[0041] According to an embodiment directed to a turbo code, the encoding means are flexible turbo-code encoding means, and the apparatus further comprises internal control means for adapting the turbo-code encoding means to the size information.
[0042] The blocks oriented code may be an LDPC code. The sizes of the sub-blocks may belong to a set of predefined sizes.
[0043] According to another aspect, an apparatus adapted to decode blocks of data encoded with a blocks oriented code comprises a decoding device having an adaptable latency. The decoding device comprises an input for receiving encoded blocks of data, decoding means, a control input adapted to receive a control information indicating whether or not a received block of data is nonequally split into a set of sub-blocks a n d an information representative of the size of the encoded block of data or of the size of each sub-block of the set. The decoding means is adapted, depending on the control information, to decode the block of data as a whole, or sequentially and successively decode the encoded sub-blocks. The decoding of each encoded sub-block begins at the end of the reception of the encoded sub-block.
[0044] The blocks oriented code may be an LDPC code.
[0045] According to an embodiment in which the blocks oriented code is a turbo code, the decoding device is a flexible turbo-code decoding device having an adaptable latency. The decoding means are flexible turbo-code decoding means, and the flexible turbo-code decoding device further comprise internal control means for adapting the turbo-code decoding means to the size information.
[0046] The fact that the turbo-code encoding device and the turbo-code decoding device are flexible, is an important feature of such embodiments. As a matter of fact, a flexible turbo-code encoding device is a device having a configuration (a software and/or a hardware configuration) capable, once implemented, to correctly process the input data, in accordance with the interleaving pattern which is different depending on the size of the processed block or sub-block of data, and regardless of the size, i.e., regardless of the content of the interleaving pattern, i.e., for example the content of interleaving tables.
[0047] A flexible turbo-code decoding device is also a device having a configuration (software and/or hardware configuration) capable, once implemented, to correctly process and distributes during each iteration, the data outputted from the processing means of the turbo-code decoder, in accordance with the interleaving and/or deinterleaving patterns which are different depending on the size of the processed block or sub-block of data, and regardless of the size, i.e., regardless of the content of the interleaving and deinterleaving tables.
[0048] This is more particularly important for a turbo-code decoding device that can be implemented in a terminal of a wireless communication system, such as a mobile phone, especially when such turbo-code decoding device is partly hardware implemented.
[0049] This is even more particularly important when the turbo-code decoding means comprise several producers which output at each cycle of a clock signal several data to be correctly distributed at each iteration to the corresponding producers in accordance with interleaving and/or de-interleaving patterns.
[0050] Thus, according to a particular embodiment of the invention, the flexible turbo-code decoding means comprises a source memory means partitioned in N elementary source memories for storing a sequence of input data, processing means clocked by a clock signal and having N outputs for producing per cycle of the clock signal N data respectively associated to N input data respectively stored in the N elementary source memories at relative source addresses, N single port target memories, N interleaving tables containing for each relative source address the number of one target memory and the corresponding relative target address therein.
[0051] Further, the internal control means are adapted to modify the content of the interleaving tables in accordance with the size information. For example, depending on the size of the block of data, a particular interleaving pattern can be read from a memory which stores several patterns corresponding to several possible sizes, and stored in the interleaving tables.
[0052] To ensure the flexibility of the turbo-code decoding means, flexible turbo-code decoding means further comprises, for example, a flexible distributing structure connected to the processing means, the interleaving tables and the target memories. The flexible structure is arranged for distributing the outputted data to the corresponding target memories in accordance with the content of the interleaving tables regardless of the content of the interleaving tables.
[0053] Several approaches are possible to realize such a flexible distributing structure. According to a first approach, the flexible distributing structure comprises N cells, each cell being connected between the N outputs of the processing means, the N interleaving tables, and the port of one target memory. Each cell is adapted to receive data from the N outputs of the processing means, to select up to N received data in accordance with the contents of said interleaving tables, and to write the selected data sequentially in the associated target memory.
[0054] According to another approach, the flexible distributing structure comprises N cells connected in a ring structure. Each cell is further connected between one output of the processing means, one interleaving table, and the port of one target memory. Each cell is adapted to receive data from the output of the processing means and from its two neighboring cells, and to dispatch at least some of the received data to at least one of the two neighboring cells or to write at least some of these received data sequentially in the associated target memory, in accordance with the contents of the interleaving tables.
[0055] Another approach for controlling the turbo-code decoding latency comprises modifying the number of iterations associated to the turbo-code decoding operations. More precisely, the internal control means of the turbo-code decoding device are adapted to modify the number of iterations performed by the processing means of the turbo-code decoding means, in accordance with a desired turbo-code decoding latency.
[0056] According to another aspect, a wireless communication system is provided, in particular of the WPAN or WLAN type, comprising at least an apparatus as defined above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0057] Other advantages and features of the invention will appear on examining the detailed description of embodiments, these being in no way limiting and of the appended drawings in which:
[0058] FIG. 1 illustrates a typical situation in an 802.11 type protocol based on a CSMA/CA multiple access method according to the prior art;
[0059] FIG. 2 illustrates diagrammatically an embodiment of an apparatus according to the invention;
[0060] FIG. 3 shows an example of a flexible turbo-code encoder according to the prior art;
[0061] FIG. 4 shows an embodiment of a turbo-code decoder according to the prior art;
[0062] FIG. 5 illustrates diagrammatically a first example of processing a block of data according to the prior art;
[0063] FIG. 6 illustrates diagrammatically another example of processing a block of data according to the invention;
[0064] FIG. 7 illustrates a latency reduction through nonequal block segmentation according to the invention;
[0065] FIG. 8 illustrates CRC checking means according to the prior art;
[0066] FIGS. 9-12 illustrate diagrammatically in greater detail a first embodiment of a flexible turbo-code decoding device according to the invention;
[0067] FIGS. 13-16 illustrate diagrammatically a second embodiment of a turbo-code decoding device according to the invention; and
[0068] FIGS. 17-19 illustrate diagrammatically another embodiment of the invention more particularly directed to an LDPC code.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0069] In FIG. 2 , APP 1 refers to an apparatus according to an embodiment of the invention for turbo-code encoding blocks of data, and APP 2 refers to an apparatus according to an embodiment of the invention for turbo-code decoding blocks of data.
[0070] The apparatuses APP 1 and APP 2 respectively comprise a flexible turbo-code encoding device TECD and a flexible turbo-code decoding device TDD. Both apparatuses communicate through a transmission channel TCH and can be, for example, incorporated respectively in two terminals belonging to a wireless communication system of the WPAN type or WLAN type.
[0071] The turbo-code encoding device TECD comprises a main input BE for receiving a block of data to be encoded, and a splitter SPL having a splitter input BE 1 , segmentation means SGM for splitting a block of data into a set of sub-blocks each having a chosen sub-block size, and a splitter output BS 1 for sequentially delivering said sub-blocks.
[0072] The architecture of such a splitter is conventional and the splitter may be, for example, realized by software. The splitter input BE 1 is connected to the main input BE by a multiplexer BX 1 , controlled by global control means GCM. The splitter output BS 1 is connected to a first input of a second multiplexer DX 2 .
[0073] The second input of the multiplexer BX 2 is directly connected to the other output of the multiplexer BX 1 . The second multiplexer BX 2 is also controlled by the global control means GCM. The output of the second multiplexer BX 2 is connected to a turbo-encoder data input BE 2 of a turbo-encoder TENC.
[0074] The turbo-encoder TENC further comprises flexible turbo-code encoding means TNCM, a turbo-encoder control input BC 2 for receiving information SIF representative of the size of the block or sub-block of data to be encoded.
[0075] The turbo-encoder TENC further comprises internal control means connected between the control input BC 2 and the flexible turbo-code encoding means for adapting the turbo-code encoding means TNCM to the size information SIF. Before transmitting the encoded blocks or sub-blocks of data on the transmission channel TCH, a channel interleaving processing may be generally performed by a channel interleaver CHIL.
[0076] FIG. 3 shows an example of turbo-code encoding means TNCM. The turbo-code encoding means TNCM comprises two constituent convolutional encoders and an interleaver. The convolutional encoders are fixed to be RSC (Recursive Systematic Convolutional) encoders of rate ½.
[0077] In Turbo-code encoders forward error correction is enabled by introducing parity bits. For Turbo-codes, the original information, denoted as systematic information, is transmitted together with the parity information. The first RSC encoder works on the block of information in its original, the second one in an interleaved sequence.
[0078] The systematic information of the second encoder is not transmitted because it can be reconstructed by de-interleaving from the systematic output of the first encoder. By this a rate of R=⅓ is achieved.
[0079] Depending on the size of the block of data to be encoded, the interleaving pattern of the interleaver is different. For example, a memory can store different sets of interleaving patterns respectively associated to different sizes of block of data. Depending on the size of the block of data to be encoded, the corresponding set will be extracted from the memory to be stored in the interleaving table of the interleaver. The turbo-code encoding means are thus flexible.
[0080] The flexible turbo-code decoding device TDD comprises an input BE 4 for receiving encoded blocks of data, flexible turbo-code decoding means TDCDM, a control input BC 3 receiving (for example, from the MAP layer) a control information CCIF indicating whether or not the received block of data is nonequally split into a set of sub-blocks, and an information SIF (also for example from the MAP layer) representative of the size of the encoded block or sub-block of data received at the input BE 4 , and internal control means ICM 2 for adapting the turbo-code decoding means TDCM to the size information.
[0081] Before being turbo-code decoded, the received blocks or sub-blocks of data are channel deinterleaved into channel deinterleaving means. In this embodiment, the channel deinterleaving means comprise two memories CHDIL 1 and CHDIL 2 working in a ping-pong manner. More precisely, whereas one block or sub-block of data is written in the interleaved form in one memory, the previously received block or sub-block of data, which has been written in the other memory, is read from this other memory in an order such that it is deinterleaved. Then, the block or sub-block written in the other memory is read by the turbo-code decoding means TDCDM whereas the following block or sub-block is written in the other memory.
[0082] As explained above, a turbo-code encoder comprises 2 RSC encoders. On the receiver side, there is a corresponding component decoder for each of them. Each component decoder implements for example a Maximum-A-Posteriori (MAP) Algorithm, and is usually a Soft-in-Soft-out (SISO) decoder.
[0083] Each block of information is decoded in an iterative manner. The systematic information and the parity information serve as inputs of the first component decoder (MAP 1 ). The soft-output of MAP 1 reflects its confidence on the received bits of being sent either as ‘0’ or ‘1’. These confidences are interleaved in the same manner as in the encoder and passed to the second component decoder (MAP 2 ) as a-priori information. The second component decoder uses this information to bias its estimation comprising the interleaved systematic information and the parity information of the second encoder. The soft-outputs are again passed on to MAP 1 , and so on. The exchange continues until stop criteria is fulfilled. Stop criteria range from simple cases, such as “fixed number of iterations”, over cyclic redundancy check (CRC) to rather complex statistical analysis.
[0084] Implementation issues for Turbo-decoder architectures using the MAP algorithm have already been discussed in several papers and are well known [A.Worm. Implementation Issues of Turbo - Decoders . Phd thesis, Institute of Microelectronic Systems, Department of Electrical engineering and Information Technology, University of Kaiserslautern, Forschungsberichte Mikroelektronik, Bd.3, Germany, 20013.
[0085] The MAP algorithm is transformed into the logarithmic domain to reduce operator strength [P. Robertson, E. Villebrun and P. Hoeher: A comparison of Optimal and Sub - Optimal MAP decoding Algorithms Operating in the Log - Domain ; Proc. 1995 International Conference on Communications (ICC'95), June 1995, Seattle, Wash., USA]: multiplications become additions, and additions are replaced by a modified comparison. It includes a forward recursion, a backward recursion and soft-output calculation.
[0086] Decoding Turbo codes by searching the most likely codeword is far too complex. Therefore, iterative decoding is advised. The two convolutional codes are decoded separately. While doing this, each decoder incorporates information that has been gathered by the other. This “gathering of information” is the exchange of soft-output values, where the bit-estimates of one unit are transformed into a priori information for the next. The decoders hence have to be soft-input soft-output (SISO) units.
[0087] The confidence in the bit estimation is represented as a Log-Likelihood-Ratio (LLR):
Λ ( d k ) = ln P ( d k = 1 ) P ( d k = 0 )
[0088] The sign shows whether this bit is supposed to be one or zero whereas the confidence in the decision is represented by the magnitude.
[0089] In order to extract the information that has been gathered during the last decoding stage, the systematic and a priori information that lead to this estimate have to be subtracted. This yields:
L 1 ( d k )=Λ 1 ( d k )− y k s −L deint 2 ( d k )
L 2 ( d k )=Λ 2 ( d k )− y kint s −L int 1 ( d k )
[0090] This is called the extrinsic information. The confidence of one decoder in a bit to have a certain value biases the initial guess of the other.
[0091] FIG. 4 shows turbo-code decoding means TDCDM comprising two MAP decoders, interleaving means IL and de-interleaving means DIL. Feeding the input of one decoder as a priori information input to the next enables the improvement over the decoding iterations. It also gave Turbo codes their name, as it resembles the “feedback-of-exhaust” used in combustion turbo engines. Inputs to the decoder are the received channel values (systematic, parity 1 and parity 2 ); during the very first MAP 1 operation, the a priori information is set to zero.
[0092] In addition to the SISO decoders MAP 1 and MAP 2 , memories are needed to store the input and output values, in particular for the interleaver and deinterleaver pattern. Of course, only one MAP unit can be used and therefore, the MAP 1 and MAP 2 operations are done serially on the same MAP unit.
[0093] For a given architecture of turbo-code decoding means TDCDM, the latency of the decoding process can be calculated. By adapting some parameters, different latencies can be reached based on the existing architecture. The parameters set can be divided in two main classes. One class is the fully adaptable parameters, which can be adapted during the operation of the turbo-code decoding means TDCDM. A second class is the implementation time adaptable parameters, which are the parameters that have to be fixed before the actual implementation of the turbo-code decoding means TDCDM.
[0094] The fully adaptable parameters are the number of iterations and the block size, whereas the implementation time adaptable parameter is the number of producers that is a number of data (LLR for example) which are produced per cycle of clock by a MAP unit. Thus, for a given number of producers and a given number of iterations, the block size of the block of data to be decoded sets the latency of the turbo-code decoding means.
[0095] Referring now again to FIG. 2 , the global control means GCM receives from an upper layer (for example a MAC layer) a control information CIF related to a required decoding latency for a block of data received at the main input BE. If, for example, the control information CIF indicates that the received data are latency-non restricted data or if the block of data would lead to a decoding latency consistent with the indication given by the control information CIF, the global control means GCM will control the multiplexer DX 1 , DX 2 in order to directly connect the input BE 2 of the turbo-encoder TENC to the main input BE. The received block of data will be turbo-encoded without being split. An example of such a situation is given in FIG. 5 in which the received block of data BLD has a length of 4096 bits. Of course, the internal control means ICM 1 have adapted the interleaving pattern to the size of the block of data (size information SIF).
[0096] Because of a coding rate of ⅓, the block of data BLD is encoded into a block of data TCBLD having a length of 3×4096 bits (=12288 bits). The turbo-encoded block of data TCBLD is then transmitted and received by the receiver in order to be turbo-decoded. The internal control means ICM 2 of the turbo-code decoding device TDD adapt the interleaving and de-interleaving pattern to the size information SIF which is known from the turbo-code decoding device, for example from the MAP layer. The block TCBLD is then turbo-code decoded in order to retrieve the initial block of data BLD of 4096 bits.
[0097] However, if the control information CIF indicates that the size of block of data which is received at the main input BE would lead to a latency decoding which is greater than the required latency, the global control means will control the multiplexers DX 1 and DX 2 to connect the main input BE to the splitter input BE 1 and to connect the splitter output BS 1 to the input BE 2 of the turbo-code encoder TENC.
[0098] Further, the global control means GCM control the splitter SPL in order to nonequally segment the block of data into a chosen number of sub-blocks. These sub-blocks will be sequentially and successively turbo-code encoded.
[0099] The last sub-block of the set to be encoded has a last sub-block size which is consistent with the desired turbo-code decoding latency. Generally speaking, at least another sub-block has the greatest sub-block size. The greatest sub-block size is consistent with a given turbo-code decoding speed.
[0100] More precisely, an example of such a segmentation is illustrated in FIGS. 6 and 7 . In this example, the received block data BLD, having a block size of 4096 bits, is split into six sub-blocks SBLD 1 -SBLD 8 . The first sub-block SBLD 1 has a sub-block size of 2048 bits, and the sizes of the sub-blocks following this first sub-block decrease from the first sub-block SBLD 1 to the last sub-block SBLD 6 to be encoded.
[0101] In fact, in the present embodiment, this set of sub-blocks comprises a sub-set of sub-blocks SBLD 1 -SBLD 5 in which the respective sizes of the sub-blocks decrease monotically from the first sub-block SBLD 1 to the last sub-block SBLD 5 . The first sub-block of the sub-set has the greatest size (2048 bits) and the size of a current sub-block of the sub-set is a half of the size of the preceding sub-block of the sub-set. Thus, the last sub-block SBLD 5 of the sub-set has a size of 128 bits.
[0102] Finally, the last sub-block SBLD 6 of the set of sub-blocks has also a size of 128 bits. This size is consistent with a desired latency which in the present case equal to 1.97 microseconds.
[0103] The six sub-blocks SBTD 1 -SBLD 6 are successively turbo-encoded and the turbo-encoder TENC delivers respectively and successively six encoded sub-blocks TCSBLD 1 -TCSBLD 6 . Each turbo-encoded sub-block TCSBLD 1 has a length equal to 3 times the size of the corresponding sub-block SBLD 1 (coding rate ⅓).
[0104] After transmission, the six encoded sub-blocks TSBLD 1 -TCSBLD 6 are successively received. Each sub-block TCSBLD 1 is then turbo-decoded. The decoding process starts directly after the reception of the first sub-block TCSBLD 1 . Of course, for the decoding, the internal control means ICM 2 have adapted the interleaving and de-interleaving pattern to the sub-block size.
[0105] Provided that the decoder can decode the block fast enough, so that at the end of the reception of sub-block n+1 (i.e., at the end of the writing sub-block n+1 in memory CHDIL 1 for example), sub-block n (which was written in memory CHDIL 2 for example) is decoded and the decoder is available (i.e., memory CHDIL 2 is available for receiving sub-block n+2, while sub-block n+1 is had from memory CHDIL 1 ). The latency is thus defined by the latency of the last sub-block decoding, as depicted in FIG. 7 .
[0106] That is the reason why the greatest size of the sub-block of the set is chosen to be consistent with the given decoding speed of the decoder. This is done to avoid, for example, a conflict between the two ping-pong deinterleaving memories CHDIL 1 and CHDIL 2 , or to avoid, a too complex management and read/write control of these two memories.
[0107] Generally, each block of data received at the main input BE of the turbo-encoder TECD comprises at the end a CRC (Cyclic Redundancy Check) word. This CRC word, which is attached to the data block in reverse order during the encoding, is transmitted and received with the other encoded data by the receiver. The turbo-code decoding device also comprises a cyclic redundancy check unit CRCU ( FIG. 8 ) for calculating from a received encoded block of data a calculated CRC word. Such a unit CRCU is well known by those skilled in the art. This CRC word is stored in a CRC register CRG 1 . Therefore, certain input parameters are necessary, which are the length of the CRC and the CRC polynominals.
[0108] The transmitted CRC word (which is called CRC sum) is stored in the register CRG 2 . Comparison means are adapted to compare the content of the register CRG 1 with the register CRG 2 . When equal, the CRC check is positive.
[0109] When a block of data has been split before being turbo-encoded, the calculated CRC word is obtained from the decoding of all the sub-blocks resulting from the segmentation of the initial data block. In other words, the CRC register is written during the decoding of all the sub-blocks. The comparison with the CRC sum is made only after the decoding of the last sub-block.
[0110] We will now refer to FIG. 9 , which illustrate two variations of implementation of a flexible turbo-code decoding means TDCDM, which permit turbo-decode blocks of data or sub-blocks of data, regardless of the value of the block size or sub-block size. For further details concerning these two variations of implementation, one skilled in the art can refer to U.S. published patent application no. 2004/0052144A1.
[0111] In this example which illustrates a first variation of the invention, the MAP 1 unit, as well as the MAP 2 unit, is a multi-LLR producer which has N outputs (N=3) for producing, per cycle of the clock signal which clocks the MAP unit, N data (N LLR) respectively associated to N input data respectively stored in N elementary source memories which form source memory means SMM.
[0112] A structure CLS of N cells is connected to the N outputs of the MAP 1 unit as well as to interleaving table means constituted by N interleaving tables. After having passed through the structure CLS, the N produced data (the N produced LLR) are stored in target memory means TMM constituted by N target memories.
[0113] Each of the source memory and the target memory is a single port memory. For the MAP 2 unit, the target memory means TMM act as source memory means and the source memory means SMM of the MAP 1 unit act as target memory means for the MAP 2 unit. Further, the interleaving table means is replaced by deinterleaving table means DILTM.
[0114] The structure and the operation of the turbo-code decoding means will be now described more in details in reference to FIGS. 10 to 12 . Although the device is described by using interleaving table means, it is clear that the same concept applies to deinterleaving table means which can be in fact considered as being also in a certain way interleaving table means.
[0115] As illustrated in greater detail in FIG. 10 , where N is equal to 3, each cell CLi of structure CLS is connected between the N outputs of the processing means MAP 1 , the N interleaving table ILTi and the port of one target memory TMi.
[0116] Generally speaking, each cell is adapted to receive data from the N outputs of the processing means, to select up to N received data in accordance with the contents of the interleaving tables, and to write the selected data sequentially in the associated target memory.
[0117] Each interleaver table ILTi comprises, for each relative source address of one source memory, the relative target address of a corresponding target memory as well as the number of this target memory. The number of the target memory and the corresponding relative target address therein constitute a target information associated to a data (LLR).
[0118] According to this first variation, each cell comprises sorting buffer means connected to the N outputs of the processing means, to the N interleaving tables and to the corresponding target memory. This is for receiving N data with their associated number of target memory and the associated relative target address, selecting from the N data those having an associated number of target memory identical to the number of the target memory connected to the cell, and delivering them sequentially to the target memory.
[0119] Of course it is possible that during one time-step the sorting buffer means of a cell does not select any data, and consequently does not deliver any data to the corresponding target memory.
[0120] As illustrated more particularly in FIG. 11 , the sorting buffer means of a cell CLi comprises especially sorting means SMM, and register means RGM. As illustrated diagrammatically in FIG. 10 , all the sorting means SMM of all the cells CLi form together a single LLR distributor referenced LLRD.
[0121] We refer now to FIGS. 11 and 12 to describe in greater detail one embodiment of a sorting buffer means of a cell CLi. Because in this example N is equal to three, three data are received in FIGS. 11 and 12 on the three inputs of the sorting buffer means. However, none of those or some of those or all the N data have to be stored in the local target RAM TMi, depending on their target information, and more particularly, on their associated number of target memory.
[0122] All these N data are received in the same clock cycle. However, only one data can be stored per cycle in the target RAM TMi. Thus, such a buffer must be able to store N values and output one value to memory in the same cycle.
[0123] Such a buffer does not need to support random access. It is implemented as a special register file capable of storing up to N values in parallel. A value is composed of a LLR-data with its associated target information, including the associated relative address.
[0124] Write and read accesses to a buffer can be modeled with writing windows where values can be stored in registers and reading windows. The writing window contains N registers, the worst case number of concurrent write accesses. Shifting it only by the number of values actually written prevents the creation of “holes” with irrelevant values.
[0125] FIG. 12 illustrates diagrammatically one embodiment of the sorting means SMM buffer still assuming that N is equal to 3. The sorting means comprises here two stages of two multiplexers 2:1 controlled by control signals C j k ,
[0126] When a control signal takes the value 1, the data which is received at the input 1 of the multiplexer is delivered at the output. By analogy, when a control signal takes the value 0, the data which is received at the input 0 is delivered at the output of the multiplexer.
[0127] The sorting means SSM are associated with the number of the target memory which is actually connected to the cell CLi. When a data arrives at the input of the sorting means SSM, its associated number of target memory is compared with the number of the target memory which is actually connected to the cell CLi. If these two numbers are identical, a decision variable r x is associated with the data and takes the value 1, for example. In the contrary, the decision variable r x takes the value 0.
[0128] Control means, realized by logic gates, generates then the control signals as mentioned thereafter:
C 1 1 =r 1
C 1 2 =r 1
C 2 1 =r 2 or r 1
C 2 2 =r 2
[0129] Thus, from the inputs, only those which are relevant for this buffer are selected and aligned such that they form an uninterrupted sequence starting from s 1 for example. These sorted sequence and the total number of relevant inputs (R) is passed to the register means RGM. The output s 1 to s R are stored in the register means RGM. This ensures a continuous filling of the register's means RGM of relevant data only.
[0130] When reading from the register means RGM, the local address a and the data d are separated again and are used to address the local target RAM accordingly.
[0131] We refer now to FIGS. 13 to 16 for the description of a second variation of flexible turbo-code decoding means. Turning first to FIG. 13 , the MAP 1 unit, as well as the MAP 2 unit, is a multi-LLR producer which has N outputs (here: N=4) for producing, per cycle of the clock signal which clocks the MAP unit, N data (here: N LLR) respectively associated to N input data respectively stored in N elementary source memories which form source memory means SMM.
[0132] N cells connected in a ring structure RGS are connected to the N output of the MAP 1 unit as well as to interleaving table means constituted by N interleaving tables. After having passed through the ring structure RGS, the N produced data (the N produced LLR) are stored in target memory means TMM constituted by N target memories.
[0133] Each of the source memory and the target memory is a single port memory. For the MAP 2 unit, the target memory means TMM act as source memory means and the source memory means SMM of the MAP 1 unit act as target memory means for the MAP 2 unit. Further, the interleaving table means is replaced by deinterleaving table means DILTM.
[0134] The structure and the operation of the turbo-code decoding means will be now described in greater detail in reference to the following FIGS. Further, as for the first variation, although the device is described now by using interleaving table means, it is clear that the same concept applies to deinterleaving table means which can be in fact considered as being also in a certain way interleaving table means.
[0135] As illustrated in greater detail in FIG. 14 , in which N is equal to 4, each cell CLi of the ring structure RGS is connected between one output of the processing means MAP 1 , one interleaving table ILTi and the port of one target memory TMi.
[0136] Generally speaking, all the cells are adapted to receive data from the respective outputs of the processing means and from their two respective neighboring cells, and to dispatch at least some of these received data to at least one of the two respective neighboring cells or to write respectively at least some of these received data sequentially in the associated target memories, in accordance with the contents of the interleaving tables.
[0137] Bach interleaver table ILTi comprises, for each relative source address of one source memory, the relative target address of a corresponding target memory as well as the number of this target memory. The number of the target memory and the corresponding relative target address therein constitute a target information associated to a data (LLR).
[0138] As illustrated more particularly in FIG. 15 , a cell CLi comprises distribution means (LD) connected to a corresponding output of the processing means MAP 1 and to the corresponding interleaving table, and also distribution means (RID, LID) connected to the two neighboring cells.
[0139] The distribution means are adapted to receive generated data respectively associated with their target information. The distribution means will then deliver the generated data associated with their target information together with corresponding direction information.
[0140] Further to the distribution means, each cell comprises also sorting buffer means LB, LOB, ROB, connected to the distribution means, but also to the corresponding target memory and to the two neighboring cells.
[0141] Generally speaking, sorting buffer means are adapted to receive the corresponding data associated with their target information and their corresponding direction information, to select from these data those which are to be actually passed through in accordance with the corresponding direction information, and delivering them sequentially.
[0142] Turning now again to the distribution means, it appears in FIG. 15 that the distribution means comprises a local distributor LD connected to the corresponding output of the processing means MAP 1 and to the corresponding interleaving table. The local distributor receives a generated local data associated with its target information containing the corresponding number of the target memory and the corresponding relative target address therein.
[0143] This local distributor LD of the cell CLi has only to decide whether the incoming data is stored in the target RAM TMi connected to the cell CLi, or has to be sent left or right. The direction for non-local data is determined based on the shortest path to the target RAM.
[0144] The local distributor, which is formed for example by a logic circuit, delivers the received data with its target information and generates a direction information for this data. This direction information is for example a word of two bits. For example, the values (0,0) means “go ahead” to the target RAM TMi. The values (0,1) means “go left” whereas the values (1,0) means “go right”.
[0145] A look-up table, not represented in FIG. 15 , is associated with the cell and contains a mapping of the different values of the direction information and the numbers of the different cells (i.e., the numbers of the different target memories). When a data arrives, the local distributor LD compares the number of the corresponding target memory associated with this data with the content of the look-up table to generate a corresponding direction information.
[0146] Two additional distributors are necessary in each cell for the left and right inputs. More precisely, the distribution means of the cell CLi comprises a right-in distributor RID and a left-in distributor LID.
[0147] The right-in distributor is adapted to receive a right-in data delivered by the right neighboring cell associated also with a target information. The right-in distributor delivers the right-in data associated with its target information, together with a direction information. The direction information is also generated using the look-up table.
[0148] By analogy, the left-in distributor LID is adapted to receive a left-in data delivered by the left neighboring cell and for delivering the left-in data associated with its target information, together with a direction information.
[0149] As illustrated in FIG. 15 , a data received by the local distributor LD can be stored in the local target memory TMi or be sent left or right. By analogy, a data received by the right-in distributor can be stored to the local target RAM THi or be sent to the left neighboring cell. A data received by the left-in distributor LID can be stored in the local RAM TMi or be sent to the right neighboring cell.
[0150] The sorting buffer means comprises a local out sorting buffer LB having three inputs respectively connected to the local, right-in and left-in distributors. The local out sorting buffer LOB has also one output connected to the port of the local target memory TMi.
[0151] The local out sorting buffer LD is adapted to receive the corresponding data associated with their target information and their corresponding direction information, selecting from these data those which are to be stored in the target memory TMi in accordance with the corresponding direction information, and for writing them sequentially in the target memory in accordance with their relative destination addresses.
[0152] In the present case, the local out buffer LB can receive 0, 1 2 or 3 data in one clock cycle, to be stored in the local target RAM. In other words, as several data sets may have the same target, the local buffer needs to be capable of storing more than one data per cycle and to deliver them sequentially one data per cycle. A specific architecture for such a buffer will be described more in details thereafter.
[0153] The left out sorting buffer LOB is adapted to receive the corresponding data associated with their target information and their direction information, to select for these data those which are to be delivered to the right-in distributor of the left neighboring cell in accordance with their direction information, and for delivering sequentially the selected data with their target information.
[0154] By analogy, the sorting buffer means comprises also a right-out sorting buffer ROB having two inputs respectively connected to the local and left-in distributor of the right neighboring cell. The right out sorting buffer ROB is adapted to receive the corresponding data associated with their target information and their direction information, selecting from these data those which are to be delivered to the left-in distributor of the right neighboring cell in accordance with their direction information, and to deliver sequentially the selected data with their target information.
[0155] We refer now to FIGS. 16 and 6 to describe more in details one embodiment of the local out buffer LB.
[0156] As already explained, three data are received on the three inputs of the local out buffer LB. However, none of those or some of those or all the three data have to be stored in the local target RAM TMi, depending on their direction information.
[0157] All these three data are received in the same clock cycle. However, only one data can be stored per cycle in the target RAM TMi. Thus, such a buffer must be able to store three values and output one value to memory in the same cycle.
[0158] Such a buffer does not need to support random access. It is implemented as a special register file capable of storing up to three values in parallel. A value is composed of a LLR-data with its associated target information, including the associated relative address.
[0159] Write and read accesses to a buffer can be modeled with writing windows where values can be stored in registers and reading windows. The writing window contains three registers, the worst case number of concurrent write accesses. Shifting it only by the number of values actually written prevents the creation of “holes” with irrelevant values.
[0160] As for the first variation, FIG. 6 illustrates diagrammatically one embodiment of the sorting means SMM. The sorting means comprises two stages of two multiplexers 2:1 controlled by control signals C j k
[0161] When a control signal takes the value 1, the data which is received at the input 1 of the multiplexer is delivered at the output. By analogy, when a control signal takes the value 0, the data which is received at the input 0 is delivered at the output of the multiplexer.
[0162] The sorting means SSM are associated with a referenced direction information for this buffer, for example the referenced direction information (0,0) for the local out sorting buffer LB. When a data arrives at the input of the sorting means SSM, its direction information is compared with the referenced direction information. If these two direction information are identical, a decision variable r x is associated with the data and takes the value 1, for example. In the contrary, the decision variable r x takes the value 0.
[0163] Control means, realized by logic gates, generates the control signals as follows:
C 1 1 =r 1
C 1 2 =r 1
C 2 1 =r 2 or r 1
C 2 2 =r 2
[0164] Thus, from the inputs, only those which are relevant for this buffer are selected and aligned such that they form an uninterrupted sequence starting from s 1 for example. These sorted sequences and the total number of relevant inputs (R) are passed to the register means. The output s 1 to s R are stored in the register means RGM. This ensures a continuous filling of the register's means RGM of relevant data only.
[0165] When reading from the register means RGM, the local address a and the data d are separated again and used to address the local target RAM accordingly.
[0166] Of course, an analogous architecture is used for the left out sorting buffer and the right out sorting buffer, with the differences that they have only two inputs instead of three.
[0167] The invention is not limited to turbo-code but can be applied more generally to blocks oriented code, as for example LDPC codes. Low-Density Parity-Check (LDPC) codes were introduced by Gallager in 1962 and rediscovered in 1996 by MacKay and Neal. LDPC codes are also described for example in U.S. published patent application no. 2003/0126551. For a long time they had no practical impact due to their computational and implementation complexity. This changed with advances in microelectronics that led to more computational power at hand for simulation and which now enables implementation. Due to their excellent error correction performance they are considered for future telecommunication standards.
[0168] An LDPC code is a linear block code defined by its sparse M×N parity check matrix H. It contains j ones per column and k ones per row, called row and column degree respectively. A (j,k)-regular LDPC code has row and column degree of uniform weight, otherwise the code is called irregular. A parity check code can be represented by a bipartite graph. The M check nodes correspond to the parity constraints, the N variable nodes represent the data symbols of the codeword. An edge in the graph corresponds to a one in the parity check matrix.
[0169] In the LDPC code encoder the packet to encode of size (N-M) is multiplied with a generator matrix G of size (N−M)×N. This multiplication leads to an encoded vector of length N. The generator matrix G and the parity check matrix H satisfy the relation GH t =0 where 0 is the null matrix.
[0170] An example of such a structure of an LDPC code encoding means LNCM is illustrated in FIG. 17 . The LDPC encoder incorporating these encoding means LNCM may include a puncturing unit, depending on the system in which this encoder is incorporated (ARQ system with or without incremental redundancy, for example).
[0171] FIG. 18 illustrates an encoding device TECD including an LDPC encoder LENC. Only the differences between FIGS. 2 and 18 will now be described. The encoding device TECD further comprises a memory containing a set of predefined sizes consistent with the architecture of the LDPC encoder.
[0172] If, for example, the control information CIF indicates that the received data are latency-nonrestricted data or if the block of data would lead to a decoding latency consistent with the indication given by the control information CIF. The global control means GCM will control the multiplexer DX 1 , DX 2 in order to directly connect the input BE 2 of the LDPC encoder LENC to the main input BE. The received block of data will be encoded without being split taking into account the size information SIF.
[0173] However, if the control information CIF indicates that the size of block of data which is received at the main input BE would lead to a latency decoding which is greater than the required latency, the global control means will control the multiplexers DX 1 and DX 2 to connect the main input BE to the splitter input BE 1 and to connect the splitter output BS 1 to the input BE 2 of the LDPC code encoder LENC.
[0174] Further, the global control means GCM control the splitter SPL in order to nonequally segment the block of data into a chosen number of sub-blocks. These sub-blocks will be sequentially and successively turbo-code encoded. With this respect the global control means will choose the sizes of the sub-blocks in the set of sizes contained in the memory MMS, and in particular the size of the last sub-block which will lead to a decoding latency equal to the desired latency, if possible, or the closest to the desired decoding latency, if not possible.
[0175] The LDPC code encoded block of data or the encoded sub-blocks are then transmitted and received by the receiver in order to be decoded. Generally speaking an LDPC code decoder comprises a decoding module which receives the encoded vector of length N and delivers an intermediate vector of length N by using the parity check matrix H. Then a de-mapping module extracts from the intermediate vector the decoded vector of length (N-M).
[0176] The basic structure of an LDPC code decoder based on message passing concept includes variable nodes and check nodes. An example of such a structure referenced LDCDM is depicted in FIG. 19 .
[0177] In this FIG., the references V 1 to V 7 represent the variable nodes connected to the input buffer IB of the decoder, and the references C 1 to C 3 are the check nodes. In a real implementation, both variable and check nodes can be seen as processing units with dedicated memory elements.
[0178] More precisely LDPC codes can be decoded using message passing algorithms, either in hard or soft decision form. The decoding is then an iterative process, which exchanges messages between variable and check nodes. Typically a Belief Propagation (BP) algorithm can be used, which exchanges soft-information iteratively between variable and check nodes. The code performance mainly depends on the randomness of the parity check matrix, the codeword size N and the code rate R=(N−M)/N.
[0179] Many publications describe LDPC decoders and the decoding algorithm implemented therein. An example of such a publication is “VLSI Implementation-Oriented (3,k)-Regular Low-Density Parity-Check Codes”, Tong Zhang and Keshab K. Parhi, IEEE Workshop on Signal Processing Systems (SiPS), September 2001.
[0180] The LDPC decoding means LDCDM, incorporated in the decoding device TDD, are adapted to decode the received block or sub-blocks of data, depending on the value of the information CCIF and taking into account the size information SIF.
[0181] Of course all what has been detailed concerning the CRC calculation and verification for the turbo-code is also true for the blocks oriented codes in particular the LDPC code. | To control a decoding latency, larger blocks are nonequally segmented into smaller ones. The decoding process starts directly after reception of the first small block. The latency is defined by the latency of the last small block decoding. Changing the number of iterations during the turbo-code decoding also permits control of the decoding latency. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is directed to a method, apparatus, and computer readable storage medium directed to a casino wagering game which is related to roulette and allows the player to make poker hands.
[0003] 2. Description of the Related Art
[0004] Casino games are currently a billion dollar industry. Casinos are always looking for new games to attract players to their casinos. The game of roulette has grown stale as players have become attracted to other more exciting wagering games.
[0005] Therefore, what is needed is a new variation of roulette which players will find more exciting than the standard version and can also encourage additional wagers from players.
SUMMARY OF THE INVENTION
[0006] It is an aspect of the present invention to provide an enjoyable and novel roulette game that can be used for wagering and can attract additional bets over a standard roulette game.
[0007] The above aspects can be obtained by a method that includes (a) receiving a first wager on a selected card value, the selected card value comprising a card rank and a suit; (b) spinning a roulette wheel comprising a plurality of slots, each slot marked with card values, each card value comprising a card rank and a suit, the wheel stopping when a ball lands in a result slot with a result slot card value; and (c) paying the first wager, if the selected card value matches the result slot card value.
[0008] The above aspects can also be obtained by a method that includes (a) receiving a first wager for a first proposition involving two cards; (b) spinning a roulette wheel comprising a plurality of slots, each slot marked with card values, each card value comprising a card rank and a suit, the wheel stopping when a ball lands in a first result slot with a first result slot card value; (c) spinning the roulette wheel to rest on a second result slot with a second result card value; and (d) if the first result card value and the second result card value render true the first proposition, then paying the first wager.
[0009] The above aspects can also be obtained by a method that includes (a) receiving a first wager for a first proposition involving two cards; (b) rolling a first die, each side of the first die marked with card values, each card value comprising a card rank and a suit, which results in a first roll; (c) receiving a second wager on a selected outcome for a second roll; (d) rolling a second die, each side of the second die marked with card values, each card value comprising a card rank and a suit, which results in a second roll; (e) if the first roll and the second roll render true the first proposition, then paying the first wager; and (f) if the second roll matches the selected outcome for the second roll, the paying the second wager.
[0010] The above aspects can also be obtained by an apparatus that includes (a) receiving a first wager for a first proposition involving two cards; (b) rolling a first die, each side of the first die marked with card values, each card value comprising a card rank and a suit, which results in a first roll; (c) rolling a second die, each side of the second die marked with card values, which results in a second roll; (d) if the first roll and the second roll render true the first proposition, then paying the first wager.
[0011] The above aspects can also be obtained by an apparatus that includes (a) a roulette wheel; and (b) a ball to spin inside the roulette wheel and land on one of a plurality of markings, wherein the markings are card values.
[0012] The above aspects can also be obtained by an apparatus that includes (a) a first die with different card values on each side, each card value comprising a card rank and a suit; and (b) a second die with various card values on each side, each various card value picturing four different suits.
[0013] These together with other aspects and advantages which will be subsequently apparent, reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Further features and advantages of the present invention, as well as the structure and operation of various embodiments of the present invention, will become apparent and more readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings of which:
[0015] FIG. 1 is an illustration of an exemplary roulette wheel, according to an embodiment;
[0016] FIG. 2 is an illustration of an exemplary roulette individual card betting layout, according to an embodiment;
[0017] FIG. 3 is an illustration of an exemplary poker hand betting layout, according to an embodiment;
[0018] FIG. 4 is a flowchart illustrating an exemplary method of implementing a roulette wagering game, according to an embodiment;
[0019] FIG. 5 is a three-dimensional view of exemplary dice with card values;
[0020] FIG. 6 is an illustration of an exemplary betting layout for use with dice with card values;
[0021] FIG. 7 is an illustration of an exemplary poker betting layout for use with dice with card values; and
[0022] FIG. 8 is a flowchart illustrating an exemplary method of implementing a dice wagering game, according to an embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.
[0024] The present general inventive concept relates to a method, apparatus, and computer readable storage medium
[0025] The present general inventive concept relates to a roulette wheel that has more interesting and exciting potential outcomes than the standard 36 number roulette wheel with two additional zeros.
[0026] In an embodiment, a poker roulette wheel can have card values as outcomes. For example, the cards 6 to ace of each of the four suits can be used, for a total of nine cards times four suits equals 36 values plus two zeros. This is the same number of possible results on a standard roulette wheel.
[0027] The poker roulette wheel can be spun consecutively, and each result can be stored and displayed. With consecutive results, a variety of interesting wagers can be made since these wagers can involve more than just one single spin on the wheel. For example, a player can wager that the next two spins will form a blackjack. If the next two spins result in cards that comprise both an ace and a 10 valued card, then this would form a blackjack and such a wager would be a winner. Contrast this with standard roulette in which each spin and wager is independent of prior spins.
[0028] FIG. 1 is an exemplary illustration of a roulette wheel, according to an embodiment.
[0029] The wheel has 38 slots, 36 card values plus a single zero and a double zero. Each slot has a respective marking. A ball will spin in the wheel and land inside a slot and the slot's respective marking is considered the result or outcome of the spin. The markings on the wheel comprise card values comprise the cards 6, 7, 8, 9, 10, jack, queen, king, and ace, in each of four different suits (for 36 card values plus two zeros=38 total slots, which is the same number of slots as a standard roulette wheel).
[0030] Note that the wheel illustrated in FIG. 1 is just one example, as other configurations can be used as well. For example, no zeros can be used, only one zero can be used, additional markings for slots can be used besides zeros and card values (e.g. a casino specific marking). The wheel is not limited to 38 slots but other numbers of slots can be used as well. For example, the wheel can comprise 2 to ace in all four suits (and one or more zeros as well).
[0031] In embodiments, any card values can be selected for inclusion on such a wheel, and can be mixed with numbers or other non-card markings for slots (e.g. such markings could be letters using in a BINGO game).
[0032] FIG. 2 is an exemplary illustration of a roulette individual card betting layout, according to an embodiment.
[0033] In this layout, bettors can select an individual card value to wager on in hopes that the result of the roulette wheel spin will match the selected card value. The layout has four rows of card values, one for each suit. Each card value is a betting area where a bettor can place a bet. The layout has a zero and a double zero betting area to bet on these slots. The layout also has three betting areas for the color of the result, red, green, or black. The layout also has betting areas for each of the four suits.
[0034] The layout as illustrated in FIG. 2 can be used to place a bet on the next spin of the roulette wheel. Note that the payouts in FIG. 2 (and any other Figure/table herein) are just exemplary, and modifications can easily be made. For example, the green payout can also pay 15/1, 16/1, or any other reasonable payout as well as 17/1.
[0035] FIG. 3 is an exemplary illustration of a poker hand betting layout, according to an embodiment.
[0036] The layout as illustrated in FIG. 3 can be used to place a wager on two or more successive spins of the roulette wheel.
[0037] There is a two-ball row with three events/wagers which can occur based on the next two spins of the roulette wheel. For example, a bettor can bet on a blackjack, and if the next two spins of the wheel result in a 10 value card and an ace (in either order), this is considered a blackjack and this wager has one. The bettor can also bet on a high pair (jj, qq, kk, or aa), and if the next two spins of the wheel result in such a pair the bettor has won. The bettor can also bet on a “combo zeros” bet in which the next two spins will be zeros (either single zero or double zero).
[0038] There is also a three-ball row with six events/wagers which can occur based on the next three spins of the roulette wheel. These events are: high pair, two pair, three of a kind, straight, flush, straight flush. Note these hands are made for three card values only (e.g. a 5, 6, 7 would be considered a straight). Note that the player can make a two pair wager in the three-ball row. In this case, a two pair can be considered a three of a kind, since the third card matches the first card and the second, although of course in other interpretations a two pair would not be possible with three cards.
[0039] There is also a four-ball row with six events/wagers which can occur based on the next four spins of the roulette wheel. These events are: high pair, two pair, three of a kind, straight, flush, straight flush or better. Note these hands are made for four card values only (e.g. a 5, 6, 7, 8 would be considered a straight).
[0040] There is also a five-ball row with six events/wagers which can occur based on the next five spins of the roulette wheel. These events are: high pair, two pair, three of a kind, straight, flush, five of a kind. Note these hands are made for five card values only (e.g. a 5, 6, 7, 8, 9 would be considered a straight). Note that additional wagers (also can be considered ‘propositions’) can be included as well in addition to those mentioned.
[0041] Note the difference in payouts across the layout. For example, a two ball high pair pays more than a five ball high pair because with five balls (cards), it is of course easier to make a high pair. On the other hand, note that a five ball flush pays more than a three ball flush, because the five ball flush is harder to achieve (since five cards need to match suit vs. three for the three ball flush). Of course, players are free to mix and match their wagers to their own preferences.
[0042] FIG. 4 is a flowchart illustrating an exemplary method of implementing a roulette wagering game, according to an embodiment.
[0043] The method can begin with operation 400 , which receives one ball and/or two ball and/or three ball and/or four ball and/or five ball wagers. For example, a five ball wager is a wager which uses the next five spins before the result can be determined. For example, the player can make a five ball wager that the next five spins will result in five of a kind (five identical cards).
[0044] From operation 400 , the method can proceed to operation 402 , which spins the poker roulette wheel a first time and pays the one ball wagers. One ball wagers can easily be determined winners or losers based on the one ball wager and the outcome of the first spin.
[0045] From operation 402 , the method can proceed to operation 404 , which spins the poker roulette wheel a second time and pays the two ball wagers. Two ball wagers can be determined winners or losers based on the two ball wager and the outcome of both the first spin and the second spin.
[0046] From operation 404 , the method can proceed to operation 406 , which spins the poker roulette wheel a third time and pays the three ball wagers. Three ball wagers can be determined winners or losers based on the three ball wager and the previous three spins.
[0047] From operation 406 , the method can proceed to operation 408 , which spins the poker roulette wheel a fourth time and pays the four ball wagers. Four ball wagers can be determined winners or losers based on the four ball wager and the previous four spins.
[0048] From operation 408 , the method can proceed to operation 410 , which spins the poker roulette wheel a fifth time and pays the five ball wagers. Five ball wagers can be determined winners or losers based on the five ball wager and the previous five spins.
[0049] It is noted that before operations 404 , 406 , 408 , 610 , additional wagers can be received as well. For example, a one-ball wager can be placed on the next spin, regardless of any other wagers live for the round (five spins). Before the dealer spins the fourth spin, then the casino may allow a 2-ball wager on the fourth and the fifth spin.
[0050] Table I below illustrates an example paytable for the two card (two ball) wagers.
TABLE I Expected House Hand Pays Combinations Probability Frequency Value Edge 0 & 00 (any 700 2 0.14% 722 −2.91% 2.91% order) 00 & 00 1400 1 0.07% 1444 −2.98% 2.98% 0 & 0 1400 1 0.07% 1444 −2.98% 2.98% Any Two Zeros 300 4 0.28% 361 −16.62% 16.62% JJ-AA 20 64 4.43% 23 −6.93% 6.93% Pair 8 144 9.97% 10 −10.25% 10.25% Blackjack 10 128 8.86% 11 −2.49% 2.49%
[0051] Table II below illustrates an example paytable for the three card (three ball) wagers.
TABLE II Expected House Hand Pays Combinations Probability Frequency Value Edge Straight Flush 300 168 0.31% 327 −7.84% 7.84% Three of a Kind 90 576 1.05% 95 −4.48% 4.48% Flush 16 2,916 5.31% 19 −9.66% 9.66% Straight 19 2,688 4.90% 20 −2.03% 2.03% Two Pairs N/A N/A N/A N/A N/A N/A Pair, JJ-AA 6 6784 12.36% 8 −13.46% 13.46% Pair 2 15,264 27.82% 4 −16.55% 16.55%
[0052] Table III below illustrates a number of possible combinations for each three card hand.
TABLE III Hand Combinations Straight Flush 168 Three of a Kind. Flush 36 Three of a Kind, no flush 540 Flush, 3 different cards 1,848 Flush, with pair 864 Straight 2,520 Pair, no zeros 12,960 Pair, one zero 864
[0053] Table IV below illustrates an example paytable for the four card (four ball) wagers.
TABLE IV Expected House Hand Pays Combinations Probability Frequency Value Edge Four of a Kind 700 2,880 0.14% 724 −3.18% 3.18% or Straight Flush Four of a Kind 850 2,304 0.11% 905 −5.97% 5.97% Straight Flush 3500 576 0.03% 3620 −3.29% 3.29% Flush 75 26,244 1.26% 79 −4.34% 4.34% Straight 50 36,864 1.77% 57 −9.83% 9.83% Three of a 20 80,640 3.87% 26 −18.79% 18.79% Kind Two Pairs 33 57,600 2.76% 36 −6.08% 6.08% Pair, JJ-AA 3 455,168 21.83% 5 −9.74% 9.74% Pair 1 1,024,128 49.12% 2 −1.77% 1.77%
[0054] Table V below illustrates a number of possible combinations for each 4 card hand.
TABLE V Hand Combinations Straight Flush 576 Four of a Kind, flush 36 Four of a Kind, no flush 2,268 Flush, 4 different cards 11,520 Flush, with pair 12,096 Flush, with 2 Pairs 864 Flush, with 3 of a Kind 1,152 Straight 36,288 Three of a Kind, no 72,576 zeros Three of a Kind, one 4,608 zero Two Pairs (no zeros) 54,432 Pair, no zeros 762,048 Pair, one zero 110,592 Pair, two zeros 3,456
[0055] Table VI below illustrates an example paytable for the five card (five ball) wagers.
TABLE VI Expected House Hand Pays Combinations Probability Frequency Value Edge Five of a Kind or 6000 11,616 0.01% 6821 −12.02% 12.02% Better (Five of a Kind, Straight Flush or Royal Flush) Four of a Kind or 175 403,296 0.51% 196 −10.42% 10.42% Better (Four of a Kind, Five of a Kind, Straight Full House or 65 1,140,576 1.44% 69 −4.99% 4.99% Better (Full House, Four of a Kind, Five of a Kind, Straight Flush or Royal Flush) Straight Flush or 30000 2,400 0.00% 33015 −9.13% 9.13% Better (Straight Flush or Royal Flush) Five of a Kind 8000 9,216 0.01% 8598 −6.94% 6.94% Four of a Kind 190 400,896 0.51% 198 −3.36% 3.36% Full House 100 746,496 0.94% 106 −4.85% 4.85% Flush 300 236,196 0.30% 335 −10.27% 10.27% Straight 125 614,400 0.78% 129 −2.30% 2.30% Three of a Kind 10 7,059,456 8.91% 11 −2.00% 2.00% Two Pairs 7 9,432,576 11.90% 8 −4.76% 4.76% Pair, JJ-AA 1.5 24,278,016 30.64% 3 −15.48% 15.48% Pair 0.4 54,625,536 68.94% 1.5 −3.48% 3.48%
[0056] Table VII below illustrates a number of possible combinations for each five card hand.
TABLE VII Hand Combinations Royal Flush 480 Straight Flush 1,920 Five of a Kind, suited 36 Five of a Kind, off-suited 9,180 Four of a Kind, flush 1,440 Four of a Kind, no flush 367,200 Four of a Kind, one zero 23,040 Full House, flush 2,880 Full House, no flush 734,400 Flush, 5 different cards 58,080 Flush, with pair 120,960 Flush, with 2 Pairs 30,240 Flush, with 3 of a Kind 20,160 Straight 612,000 Three of a Kind, no zeros 5,140,800 Three of a Kind, one zero 737,280 Three of a Kind, two zeros 23,040 Two Pairs, no zeros 7,711,200 Two Pairs, one zero 552,960 Pair, no zeros 30,844,800 Pair, one zero 7,741,440 Pair, two zeros 552,960 Pair, three zeros 11,520
[0057] In a further embodiment, hands can be made from dice instead of spins on a roulette wheel. Dice can be used, wherein each die has card values on each side. This embodiment can be played similarly to the embodiments described herein but instead of using a roulette wheel to generate cards and then hands, dice can be used to generate cards and hands. The method described in FIG. 4 can be used with respect to dice, in that instead of spinning the wheel a successive die is rolled to generate a card value. Otherwise, the method as described in relation to FIG. 4 can be applied to the dice embodiment below described.
[0058] Table VIII illustrates one example of a set of dice with respective card values. It is noted that the layouts illustrated in Table VIII are just exemplary, and different card values and/or number of dice can be used. Note that each die is different. It does not matter which card value has which position on each die relative to the other values on that particular die. Note that the dice can be rolled simultaneously or in succession. If the dice are rolled in succession, then bets can be made on the next roll each of die in addition to any prior bets being made on hands that will be made by multiple dice.
TABLE VIII Die #1 (9h, 10c, Jd, Qs, Kh, Ac) Die #2 (9c, 10d, Js, Qh, Kc, Ad) Die #3 (9d, 10s, Jh, Qc, Kd, As) Die #4 (9s, 10h, Jc, Qd, Ks, Ah) Die #5 (9, 10, J, Q, K, A of “All Suits”, which shows a suit in each corner of face)
[0059] FIG. 5 is a three-dimensional view of exemplary dice with card values. Note that these are just examples and other combinations of card values can be used as well. Note the multi-suited ace 500 , which is an card with the rank of ace but which also pictures all four suits. All of the other card ranks can be multi-suited as well. A multi suited card can have the rank of the card but can also take on any of the four suits. For example, a multi suited ace 500 can serve as an ace of diamonds, ace of clubs, ace of hearts, and ace of spades. Thus, if four other cards are: 10 hearts, jack hearts, queen hearts, king hearts, and the fifth card is a multi suited ace, then the five cards would comprise a royal flush.
[0060] FIG. 6 is an illustration of an exemplary betting layout for use with dice with card values.
[0061] A dice roll #1 row 600 can be used to receive bets on an outcome of a roll of a first die. A dice roll #2 row 602 can be used to receive bets on an outcome of a roll of a second die. A dice roll #3 row 604 can be used to receive bets on an outcome of a roll of a third die. A dice roll #4 row 606 can be used to receive bets on an outcome of a roll of a fourth die. A dice roll #5 row 608 can be used to receive bets on an outcome of a roll of a fifth die. Note the fifth die can optionally be a multi-suit die, wherein each rank can take on all suits. A suit specific bet on this die may not be possible. Note these bets can be placed at any time before the respective die is rolled. After the five dice are rolled in succession, a new round can start and the first die can be rolled again. Each of the indicia for each row matches the indicia on the respective die. This layout can be used with the dice configured as illustrated in Table VIII. A suit/color column 610 can be used by the player to place bets on the suit or color of the next roll. The suit/color column 610 can be bet after each roll, and is typically resolved after each roll.
[0062] FIG. 7 is an illustration of an exemplary poker hand betting layout for use with dice with card values.
[0063] The layout contains betting areas (squares) in which players can place chips in order to make certain hands (or propositions). If there is an ‘X’ in a betting area it signifies that that particular proposition is impossible to make and is not allowed. For example, it is not possible to make three of a kind with only two cards.
[0064] The layout contains a two-dice bet column for bets after two dice have been rolled, a three-dice bet column for bets after three dice have been rolled, a four-dice bet column for bets after four dice have been rolled, and a five-dice bet column for bets after five dice have been rolled. For example, betting on a three of a kind to occur after four dice are rolled pays 10:1 (ten to one).
[0065] Note that some payouts are written in each betting circle. The payouts listed are merely examples. Any betting area that does not contain an ‘X’ or a payout should typically have a payout written inside the betting area when the game is in actual play (some payouts are simply not included in the figure). The casino may also decide not to offer certain wagers even though they may be possible. For example, the casino may not wish to offer a high card wager for five dice, because the payout would be too low.
[0066] FIG. 8 is a flowchart illustrating an exemplary method of implementing a dice wagering game, according to an embodiment. Note that FIG. 8 is similar to FIG. 4 , but uses dice instead of a roulette wheel.
[0067] The method can start with operation 800 , which can receive 1 card and/or 2 card and/or three card and/or four card and/or five card wagers.
[0068] From operation 800 , the method can proceed to operation 802 , which rolls the first die and pays the one card wagers. From operation 802 , the method can proceed to operation 804 , which rolls the second die and pays the two card wagers. From operation 804 , the method can proceed to operation 806 , which rolls the third die and pays the three card wagers. From operation 806 , the method can proceed to operation 808 , which rolls the fourth die and pays the four card wagers. From operation 808 , the method can proceed to operation 810 , which rolls the fifth die and pays the five card wagers.
[0069] It is noted that all of the wagers may be paid (resolved) at the end of operation 810 instead of roll by roll (this can also be the case with respect to FIG. 4 as well). It is also noted that each of the five die can be different (for example as illustrated in Table VIII), or alternatively some or all of the dice can be identical.
[0070] As with FIG. 4 , any results can typically be posted publicly so players can see the prior results so they know if they qualify to make certain bets and what cards they would need to qualify (e.g. if the first die rolls a Ac, the player knows the next roll must be an A to make a 2 card high pair). Also as with FIG. 4 , upon each operation ( 802 to 810 ), additional wager(s) can be taken before each roll. For example, a player can make a 1 card wager in operation 800 , and then after operation 802 , the player can make a new 1 card wager before operation 804 on the outcome of the second roll. The player can also make a new 2 card wager before operation 804 to be resolved on rolls two and three (operations 804 and 806 ).
[0071] Described herein is a method in which wagers can be resolved using a roulette wheel and also dice. Any of the methods/apparatus described herein can also be used with a deck of cards, whereby cards are dealt to generate card values.
[0072] It is also noted that any and/or all of the above embodiments, configurations, variations of the present invention described above can mixed and matched and used in any combination with one another.
[0073] Moreover, any description of a component or embodiment herein also includes hardware, software, and configurations which already exist in the prior art and may be necessary to the operation of such component(s) or embodiment(s).
[0074] Further, the operations described herein can be performed in any sensible order. For example, when a player wins a particular stage the player can be paid at that point in time or when the entire game (all stages) is over. As another example, if the player exceeds a current respective point threshold for that stage, the dealer can take the players respective wager at that point or continue to play out the entire game before taking the wager. Further, cards can be dealt face down and revealed at a later time or dealt face up, as each of these variations are interchangeable. Any operations not required for proper operation can be optional. Further, all methods described herein can also be stored on a computer readable storage to control a computer.
[0075] The many features and advantages of the invention are apparent from the detailed specification and, thus, it is intended by the appended claims to cover all such features and advantages of the invention that fall within the true spirit and scope of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | A roulette game which can form poker hands. A roulette wheel has card values on the outside as opposed to the standard numbered values. The wheel can be spun a plurality of times in sequence, and each spin can be used as a card value. After five such spins, a five card poker hand can be created, although with less spins, a smaller poker hand can also be created. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates to a foldable knife, more particularly to a foldable knife having an actuating portion adapted to push a blade body out of a retaining space of the foldable knife by one single hand of a user.
BACKGROUND OF THE INVENTION
[0002] The currently commercially available foldable knife is illustrated in FIG. 1 . The foldable knife 10 includes a knife holder 12 and a blade body 11 , wherein one end of the blade body 11 is pivotally connected with one end of the knife holder 12 . The blade body 11 can thus rotate about the knife holder 12 , thereby retaining the blade body 11 into a retaining groove 13 formed on one side of the knife holder 12 . When the user wants to open the foldable knife 10 , he/she must use one hand to hold the knife holder 12 and the other hand to pull the blade body 11 out of the retaining groove 13 , so as to pull out the knife blade 12 .
[0003] However, the structural design of the conventional foldable knife 10 describe above requires the use of both hands to pull the blade body 11 out of the knife holder 12 . Under some special circumstances or for some emergency cases, the user can not pull out the foldable knife 10 with only one free hand. For example, if one hand of a diver were trapped by fishnet, he/she would not have both hands free to open the foldable knife 10 to cut off the fishnet. Therefore, the life of the diver will be threatened if the oxygen contained in the scuba can not sustain until he/she rescues himself/herself.
[0004] Therefore, referring again to FIG. 1 , some manufacturers of foldable knifes add a protrusively formed actuating rod 14 on both sides of the blade body 11 . When the blade body 11 is retained in the retaining groove 13 , the two actuating rods 14 provides the user the means to open the knife. Therefore, it is easy to rotate the blade body 11 out of the retaining groove 13 of the knife holder 12 by pushing the actuating rod 14 with only one hand.
[0005] However, since modern people requires a more personal and artistic structural design for knifes, the two actuating rods 14 are often very small in size, so as to reduce their influence on the structural design. However, the smaller the actuating rod is designed, the harder for user to open the knife. Especially for those users of unskillful fingers, the force exerted on the small actuating rod often hurts the fingers of the users.
[0006] Moreover, the two actuating rods 14 of the foldable knife 10 are often not exceeding the outer edge of the knife holder 12 for the convenience of carrying and for the overall design style. Therefore, when the user of the foldable knife 10 wants to push the actuating rod 14 , the force exerted on the actuating rod 14 forms an angle with the direction of the blade body 11 rotating away from the retaining groove 13 . The effective force that the user exerted to the actuating rod is thus small due to the presence of such an angle. Even worse, if the direction of the force that the user exerted on the actuating rod 14 is wrong, it is possible that the user can not rotate the blade body 11 out from the retaining groove 13 .
[0007] For the above reasons, it is an important issue to design a foldable knife that is operable by one single hand, so as to enhance the functionality and the usefulness of the foldable knife, yet keeping the foldable knife of an artistic and esthetic style.
SUMMARY OF THE INVENTION
[0008] In accordance with the background description set forth above, the inventors of the present invention have devoted themselves to the study and experimentation of foldable knifes with due diligence. Finally, a new foldable knife, which is the subject matter of the present invention, is developed.
[0009] It is an object of the present invention to provide a foldable knife operable with one single hand. The foldable knife comprises a blade body and a knife holder. The knife holder includes a first plate and a second plate stacked on the first plate. A retaining space is formed between the first plate and the second plate, so as to retain the blade body therein. One end of the blade body comprises a sharp portion, while the other end of the blade body is pivotally connected to one end of the knife holder. In this manner, the blade body can be retained in the retaining space or can be rotated out of the retaining space. At least one surface of the blade body includes an actuating rod formed thereon. An actuating portion is formed on the first plate to cooperate with the actuating rod. When the knife body is retained in the retaining space, the actuating rod is aligned to the adjacent actuating portion. At this time, one can operate the actuating portion to push the actuating rod moving towards outside of the knife holder, thereby pushing the blade body out of the retaining space.
[0010] It is another object of the present invention to form an elastic structure in the knife holder. When the actuating portion pushes the actuating rod and moves towards outside of the knife holder, the elastic structure can eject the blade body again out from the knife holder when the blade body is pushed out of the knife holder.
[0011] It is yet another object of the present invention to provide a foldable knife that can reduce the force that the user needs to exert for rotating the blade body out of the knife holder. It is much easier to rotate the blade body out of the knife holder by operating the actuating portion to push the actuating rod than operating on the actuating rod directly.
[0012] The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a perspective view of a conventional foldable knife.
[0014] FIG. 2 is a perspective view of a foldable knife of the present invention.
[0015] FIG. 3 is an explosive view of the foldable knife of the present invention.
[0016] FIG. 4 is a side elevation of the foldable knife, in accordance with one aspect of the present invention.
[0017] FIG. 5 a side elevation of the foldable knife, in accordance with another aspect of the present invention.
[0018] FIG. 6 is a sectional view of the foldable knife of the present invention before it is being folded.
[0019] FIG. 7 a sectional view of the foldable knife of the present invention after it is being folded.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Referring to FIG. 2 , a foldable knife of the present invention includes a blade body 21 and a knife holder 30 , wherein the knife holder 30 is composed of a first plate 31 and a second plate 32 stacked with the first plate 31 . There is formed a retaining space 33 between the first plate 31 and the second plate 32 , so as to retain the blade body 21 . One end of the blade body 21 includes a sharp portion 22 , while the other end is pivotally connected to one end of the knife holder 30 . The blade body 21 can then be retained in the retaining space 33 , or rotated out from the retaining space. Moreover, at least one surface of the blade body 21 includes an actuating rod 23 , while an actuating portion 40 is formed on the first plate 31 incorporating with the actuating rod 23 . When the blade body 21 is retained in the retaining space, the actuating rod 23 is situated at the position of the actuating portion 40 , as shown in FIG. 3 and FIG. 4 . Referring now to FIG. 5 , one can push the actuating rod 23 directly from operating the actuating portion 40 , so as to push the blade body 21 out from the retaining space 33 . In this manner, the blade body 21 is rotated out of the knife holder 30 .
[0021] Referring again to FIG. 2 , the side surfaces of one end of the blade body 21 is pivotally connected to the inner surfaces of one end of the knife holder 30 (i.e. the opposite surfaces of the first plate 31 and the second plate 32 ) via at least a pivot 34 , such that the blade body 21 can rotate about the center of the pivot 34 .
[0022] Referring to FIG. 2 and FIG. 3 , the first plate 31 includes an upper cover 35 and a lower covered 36 stacked with the upper cover 35 . The actuating portion 40 is disposed between the upper cover 35 and the lower cover 36 . In addition, a guiding hole 45 is formed on one side of the first plate 31 facing the blade body 21 adjacent the actuating portion 40 . The guiding hole 45 provides one part of the actuating portion 40 to protrude therefrom. Furthermore, a sliding groove 41 is formed on the upper cover 35 corresponding to the actuating portion 40 . One end of a sliding piece 42 of the actuating portion 40 protrudes the first plate 31 , thereby providing users of the foldable knife to push thereon. The other end of the sliding piece 42 is restricted between the upper cover 35 and the lower cover 36 , such that the sliding piece 42 is moving smoothly when pushed.
[0023] In addition, referring again to FIG. 2 and FIG. 3 , the actuating portion 40 further includes a foil 43 . The one end of the foil 43 and the other end of the foil 43 form a bending angle. The best bending angle is determined according to the position of the sliding groove 41 and the sliding track 44 . In this particular embodiment, the bending angle is between 30 degrees and 180 degrees. One end of the foil 43 is pivotally connected to one end of the knife holder 30 . In this manner, the other end of the foil 43 can be rotated about the center of the pivotal connections between the foil 43 and the knife holder 30 and protrudes the guiding hole 45 , thereby pushing the actuating rod 23 . The blade body 21 is then pushed out from the retaining space 33 . Further, a sliding track 44 is formed on the other end of the foil 43 so as to dispose the sliding piece 42 therein. Moreover, the sliding track 44 crosses the sliding groove 41 .
[0024] Referring to FIG. 4 , where an aspect of the knife holder 30 is illustrated. The foil 43 is retained in the knife holder 30 . The sliding piece 42 is situated in the sliding groove 41 away from the other end of the foil 43 . The sliding piece 42 is also situated in the sliding track 44 away from the other end of the foil 43 . Referring to FIG. 5 , where another aspect of the knife holder 30 is illustrated. The sliding piece 42 moves along the sliding groove 41 towards the other end of the foil 43 . At the same time, the sliding piece 42 is situated in the sliding track 44 pushing the foil 43 to move. The sliding track 44 can thus move along the sliding piece 42 , so as to protrude the foil 43 out of the knife holder 30 and to push the actuating rod 23 .
[0025] Referring to FIG. 2 , FIG. 3 , FIG. 4 , and FIG. 5 , the foil 43 in the present invention can be pivotally connected with the pivot 34 . In this manner, the foil 43 can rotate about the center of the pivot 34 . However, it is appreciated that the foil 43 can be pivotally connected to any position of the handle 30 . As long as the foil 43 can rotate within the knife holder so as to protrude part of the foil 43 out of the guiding hole 45 thereby pushing the actuating rod 23 , it is considered within the scope of the present invention.
[0026] Referring again to FIG. 3 , the actuating portion 40 further includes a recovery spring 46 . The recovery spring 46 is disposed between the upper cover 35 and the lower cover 36 . One end of the recovery spring 46 is connected with the sliding piece 42 , while the other end thereof is connected with the other end of the first plate 31 away from the pivot 34 . The recovery spring 46 is preferably disposed on the upper cover 35 (or the lower cover 36 ) directly facing the sliding groove 41 . In this manner, referring to FIG. 4 , when the sliding piece 42 is situated in the sliding groove 41 away from the other end of the foil 43 , the pitch of the recovery spring 46 is denser. On the other hand, referring to FIG. 5 , when the sliding piece 42 is moving in the sliding groove 41 towards the other end of the foil 43 , the pitch of the recovery spring 46 becomes looser, thereby generating an elastic recovery force. This elastic recovery force will be used to pull the sliding piece 42 back to the position in the sliding groove 41 away from the other end of the foil 43 . Thus, after the user of the foldable knife 20 pushes the sliding piece 42 to rotate out the blade body 21 from the knife holder 30 , the foil 43 and the sliding piece 42 can be recovered to their original position by taking advantage of the elastic recovery force.
[0027] Referring again to FIG. 3 , the knife holder 30 (as shown in FIG. 2 ) includes an elastic structure 37 . When the actuating portion 40 pushes the actuating rod 23 to move towards outside of the knife holder 30 and the blade body 21 is pushed outside of the knife holder 30 , the elastic structure 37 can no longer eject the blade body 21 out of the knife holder 30 .
[0028] Referring again to FIG. 3 , the elastic structure 37 includes an actuating piece 24 and an elastic strip 38 , wherein the actuating piece 24 is disposed on the other end of the blade body 21 . A notch 25 is formed on the elastic piece 24 . The elastic strip 38 is extendedly disposed in the knife holder 30 (as shown in FIG. 2 ). One end of the elastic strip 38 is disposed adjacent the actuating piece 24 . When the blade body 21 is rotated into the retaining space 33 , the edge of the actuating piece 24 having the largest outer radius will press the elastic strip 38 , thereby deforming the elastic strip 38 to reserve some elastic restoration force. Therefore, when the blade body 21 is rotated into the retaining space 33 , the user of the foldable knife 20 (as shown in FIG. 2 ) can use only one hand to hold the knife holder 30 and use the thumb and the index finger to push the actuating rod 23 . In this manner, the actuating piece 24 starts rotating and gradually releases the pressing force of the elastic strip 38 until the elastic strip 38 extrudes into the notch 25 . Since the elastic strip 38 reserves the elastic restoration force through deformation, the restoration force is exerted to the notch 25 of the actuating piece 24 , thereby generating the torque for rotating the blade body 21 out of the retaining space 33 . The blade body 21 is then rapidly ejected out of the knife holder 30 .
[0029] Referring to FIG. 2 and FIG. 3 , the surface of the second plate 32 facing the retaining space 33 includes an slightly bent elastic foil 54 formed thereon facing the blade body 21 . When the blade body is retained in the retaining space 32 , the surface of the blade body 21 press on the elastic foil 54 and deforms the elastic foil 54 . When the blade body 21 is rotated out of the retaining space, the elastic foil 54 will be recovered to its slightly bent shape, thus making the end point of the elastic foil 54 contacts the bottom edge of the blade body 21 . In this manner, the stability of the blade body 21 disposed on the knife holder 30 is enhanced. This can prevent the foldable knife 20 from accidentally cutting the fingers of the user when the blade body 21 rotates out abruptly. On the contrary, when the elastic foil 54 is deformed from pressing, the bottom edge of the blade body 21 can be released from the contact with the end point of the elastic foil 54 . At this time, the blade body 21 can be rotated into the retaining space 33 , and presses the elastic foil 54 again.
[0030] Referring to FIG. 3 , an extension foil 50 is extrusively formed on the foil 43 opposite to one end of the sliding track 44 . When the foil 43 rotates in the first plate 31 (as shown in FIG. 2 ), the extension foil 50 also rotates between the upper cover 35 and the lower cover 36 . Further, a penetrating hole 52 is formed on one surface of the lower cover 36 facing the upper cover 35 and being between one end of the lower cover 36 adjacent the pivot 34 and the actuating portion 40 , so as to contain therein a locking element 51 . A positioning hole 53 is formed on one end of the blade body 21 opposite to the sharp portion 22 and facing one side of the first plate 31 . (The preferred position of the positioning hole 53 is between the actuating piece 24 and the actuating rod 23 .) In this manner, referring to FIG. 3 and FIG. 7 , the positioning hole 53 aligns with the penetrating hole 52 when the blade body 21 is retained in the retaining space, the sliding piece 42 is situated in the sliding groove 41 away from the other end of the foil 43 , and the sliding piece 42 is situated in the sliding track 44 away from the other end of the foil 43 . The extension foil 50 in the first plate 31 is also aligned to the penetrating hole 52 . Now that the locking element 51 contained in the penetrating hole 52 moves towards the retaining space when blocked by the extension foil 50 and enters the positioning hole 53 , so as to affix the blade body 21 .
[0031] Under this condition, the actuating portion 40 is being operated and the foil 43 starts rotating. The blade body 21 is the driven to rotate out of the retaining space. Referring to FIG. 3 and FIG. 6 , the extension foil 50 is also driven to leave its original position. Now, the locking element 51 can move towards the upper cover 35 (or being blocked by the blade body 21 and moves towards the upper cover 35 ). The blade body 21 can then be rotated out of the retaining space. On the contrary, referring again to FIG. 3 and FIG. 7 , when the blade body 21 is retained in the retaining space 33 , the extension foil 50 is aligned to the penetrating hole 52 since the actuating portion 40 is not being operated. The locking element 51 is then pushed towards the retaining space 33 , whereby the locking element 51 can enter the positioning hole 53 to affix the blade body 21 when the blade body enters the retaining space 33 .
[0032] While the invention has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the following claims. | The present invention is to provide a foldable knife operable with one single hand, which comprises a knife holder including a retaining space formed between a first plate and a second plate, a blade body having one end pivotally connected to one end of the knife holder and capable of being retained in the retaining space or rotated out of the retaining space, at least an actuating rod formed on one surface of the blade body; and an actuating portion formed on the first plate to cooperate with the actuating rod. When the knife body is retained in the retaining space, the actuating rod is aligned to the adjacent actuating portion adapted to push the actuating rod moving towards outside of the knife holder, thereby pushing the blade body out of the retaining space. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation application of U.S. application Ser. No. 10/698,192 filed Oct. 31, 2003 now U.S. Pat. No. 7,128,061 entitled “Supercharger.”
FIELD OF THE INVENTION
The present invention generally relates to superchargers. More particularly, the invention concerns a centrifugal supercharger.
BACKGROUND OF THE INVENTION
Superchargers have become pervasive in automobiles, boats, aircraft, and commercial stationary engines as the need to maximize power output has increased due to the use of smaller engines. Centrifugal superchargers employ a high-speed impeller to develop their boost pressure. Although such high-speed machinery places extreme demands on the associated drive machinery, e.g., bearings, seals, shafts, housing components, and the like, centrifugal compressors benefit from very high thermodynamic efficiencies, resulting in optimum engine outputs.
Most centrifugal superchargers employ some sort of speed increasing mechanism to provide the rotation speed for the centrifugal compressor portion of the device to work. This mechanism, which is usually comprised of two parallel shafts with either a belt or gear system connecting them, requires matching cylindrical bores for the shafts and bearings. In the current art, a minimum of two bearing bores and two locating pin bores are machined in each part that comprise the supercharger case and cover, and the two are assembled like two halves of a clam shell, e.g. the separating plane of the individual case components is orthogonal to both shafts. This process requires eight (8) precision boring operations. A significant problem exists in manufacturing the very precise bores of the case components. For example, the accuracy needed to obtain the desired relationship between the two shafts requires true position and parallelism tolerances of 0.0005 inches. These extremely tight tolerances challenge the capabilities of even the newest and best state-of-the-art computer-controlled machining centers. Manufacturing these assemblies requires expensive and time-consuming set-up, machining, measuring and matching procedures. Even with very careful manufacturing procedures, a significant component rejection rate exists, due to parts that do not meet the strict tolerance requirements.
In view of the above, there exists a need for an efficient supercharger that is easy to manufacture and service.
SUMMARY OF THE INVENTION
The present invention provides a very efficient supercharger that is easy to manufacture and service.
One feature of the present invention comprises a supercharger that has a case, or housing that is split into a primary section and a removable section. This two-piece housing greatly enhances and simplifies the ability to attain the required precision manufacturing tolerances.
Another feature of the present invention comprises a sleeve, or intermediate member disposed substantially around a shaft located within the supercharger housing. The intermediate member may be used on the driveshaft, the impeller shaft, or may be used on both shafts. Between the intermediate member and the shaft are bearing assemblies that allow the shafts to rotate. One feature of the intermediate member is that it has a coefficient of thermal expansion (CTE) that is substantially similar to the CTE of the bearing assemblies.
Yet another feature of the present invention comprises a disengagement device located between the supercharger impeller and the engine, or motor that drives the supercharger. The disengagement device allows selective disengagement of the impeller from the engine.
A further feature of the present invention comprises an impeller shaft support designed to reduce mechanical stress and associated rotodynamic instabilities.
Yet another feature of the present invention comprises a supercharger impeller having at least three sets of blades. A first set of primary blades has a first height and a set of secondary, or splitter blades have a second, shorter height. A third set of splitter blades has a third height that is less than the height of the second set of splitter blades.
Another feature of the present invention comprises a supercharger having a modular compressor housing. The modular compressor housing includes two or more modular components. In one embodiment, the compressor housing includes a main housing and a shroud. In other embodiments, the compressor housing includes a main housing, a shroud and a diffuser.
These and other features and advantages of the present invention will be appreciated from review of the following detailed description of the invention, along with the accompanying figures in which like reference numerals refer to like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view showing a supercharger, its driveshaft, and pulley arrangement attached to an engine;
FIGS. 2A and 2B are cross-sectional and exploded views, respectively, of a supercharger in accordance with the principles of the present invention;
FIGS. 2C and 2D are plan, and elevation views, respectively, of an oil reservoir cover for use with the supercharger of the present invention;
FIGS. 3A and 3B are cross-sectional views of a sleeve assembly for use with the supercharger of the present invention;
FIG. 3C is an isometric view of an impeller shaft cartridge assembly for use with the supercharger of the present invention;
FIG. 3D is cross-sectional view of a portion of the supercharger of the present invention, illustrating a lubrication conduit and an end view of the impeller shaft and sleeve;
FIGS. 4A and 4B are exploded and cross-sectional views, respectively, depicting a disengagement device for use with the supercharger of the present invention;
FIG. 4C illustrates a graph of an impeller shaft acceleration/deceleration rate of a conventional supercharger;
FIG. 4D illustrates a graph of an impeller shaft acceleration/deceleration rate of a supercharger constructed according to one embodiment of the present invention;
FIGS. 5A and 5B are cross-sectional views of a spacer assembly for use with the supercharger of the present invention;
FIGS. 6A and 6B are perspective and side views, respectively, of an impeller for use with the supercharger of the present invention; and
FIGS. 7A and 7B are side and exploded views, respectively, of a modular compressor housing for use with the supercharger of the present invention.
It will be recognized that some or all of the Figures are schematic representations for purposes of illustration and do not necessarily depict the actual relative sizes or locations of the elements shown. The Figures are provided for the purpose of illustrating one or more embodiments of the invention with the explicit understanding that they will not be used to limit the scope or the meaning of the claims.
DETAILED DESCRIPTION OF THE INVENTION
In the following paragraphs, the present invention will be described in detail by way of example with reference to the attached drawings. Throughout this description, the preferred embodiment and examples shown should be considered as exemplars, rather than as limitations on the present invention. As used herein, the “present invention” refers to any one of the embodiments of the invention described herein, and any equivalents. Furthermore, reference to various feature(s) of the “present invention” throughout this document does not mean that all claimed embodiments or methods must include the referenced feature(s).
Referring to FIG. 1 , a supercharger 10 constructed according to the present invention includes a driveshaft 12 for receiving rotational force from an engine 14 via a pulley and belt assembly 16 . More particularly, one end of the driveshaft 12 is attached to supercharger 10 and the opposite end is attached to the pulley and belt assembly 16 . In the illustrated embodiment, driveshaft 12 is depicted as relatively long with respect to the other engine components. However, driveshaft 12 may be considerably shorter such that the supercharger is in close proximity to the pulley and belt assembly 16 without departing from the scope of the present invention. Furthermore, driveshaft 12 may by comprised of an additional shaft member with supporting bearing structure such as described in U.S. Pat. No. 6,092,511 without departing from the scope of the present invention.
Referring to FIGS. 2A and 2B , supercharger 10 comprises driveshaft 12 , impeller shaft 20 , impeller 22 , compressor housing 24 , gear housing 26 and lubrication reservoir 28 . In operation, air is drawn through opening 24 a in the compressor housing 24 and into impeller 22 . Impeller 22 , in conjunction with the compressor housing 24 , compresses the air before discharging it out of the compressor housing 24 . Preferably, impeller 22 is designed to discharge the air smoothly into compressor housing 26 , without substantial discontinuity or aerodynamic perturbation that may reduce performance.
Driveshaft 12 is mechanically coupled to impeller shaft 20 such that rotation of the driveshaft imparts rotation on the impeller shaft 20 , thereby causing rotation of impeller 22 . The mechanical coupling between the input drive and impeller shafts includes a drive gear 30 disposed about driveshaft 12 and an impeller gear (not shown) disposed about impeller shaft 20 . In a preferred embodiment, the drive gear 30 has a larger circumference than the impeller gear, thereby causing the impeller gear to rotate faster than the drive gear 30 .
As shown in FIGS. 2A and 2B , the gear housing 26 defines a chamber that contains the drive gear and impeller gear. Gear housing 26 includes a primary section 26 a and a removable section 26 b configured to mate with the lower section. Removable section 26 b is attached to primary section 26 a by way of conventional removable fasteners 34 such as screws or bolts, which pass through apertures 34 a in the removable section and corresponding apertures 34 b in primary section. Gear housing 26 also contains driveshaft bearing assemblies 38 a , 38 b disposed on either side of drive gear 30 and impeller shaft bearing assemblies 40 a , 40 b disposed on either side of the impeller gear (not shown). Bearing assemblies 40 a , 40 b may comprise single or multiple bearing elements. The bearing elements may be deep-groove or angular contact types, without departing from the scope of this invention. Advantageously, and in the case of multiple angular contact bearing elements, the bearing assemblies 40 a , 40 b may be configured in tandem pairs (shown), or may be rigidly preloaded duplex sets, configured in either “DF” or “DB” arrangements.
The impeller gear (not shown) is coupled to impeller shaft 20 such that the rotation of impeller gear imparts rotation to the impeller shaft and impeller 22 . Drive gear 30 is connected to driveshaft 12 such that the rotation of drive gear 30 imparts rotation to the impeller shaft 20 .
As best seen in FIG. 2B , removable gear housing section 26 b includes a semicircular recess 31 , which, in combination with a corresponding recess 33 in primary gear housing section 26 a , provides an opening dimensioned for the passage of driveshaft 12 . Gear housing 26 is thereby split in two sections along a dividing plane that is substantially parallel with the rotational axis of driveshaft 12 . In the illustrated embodiment, the dividing plane is substantially coplanar with the rotational axis of the driveshaft 12 . Removing the removable gear housing section 26 b provides access to driveshaft 12 , drive gear 30 and driveshaft bearing assemblies 38 a , 38 b . It will be appreciated that the gear housing 26 may be split in any number of different ways. For example, the gear housing 26 maybe split along a dividing plane that is substantially parallel with the impeller shaft 20 . Alternatively, the gear housing 26 may be split along multiple dividing planes that may be substantially parallel with both the impeller shaft 20 and the driveshaft 12 . Or, the gear housing 26 may be split along other suitable planes.
One feature of this aspect of the invention is that the demanding manufacturing tolerances for the gear housing 26 are much easier to achieve, thereby increasing manufacturability, and decreasing waste generated by parts that are out-of-tolerance. In addition, the number of precision machining operations required to manufacture the gear housing 26 can be significantly reduced, e.g., from 8 individual boring operations to two. Advantageously, this reduces manufacturing costs. In addition, this invention feature adds rigidity to the supercharger 10 , and maximizes the manufacturing precision, thereby resulting in improved alignments between gears and shafts for smoother, quieter operation, simplified manufacturing processes, and reduced overall manufacturing costs.
Again referring to FIGS. 2A , 2 B and 4 A, gear housing 26 preferably includes a cover plate 42 , that when removed provides access to the impeller shaft 20 , impeller gear (not shown) and impeller shaft bearing assemblies 40 a , 40 b . The cover plate 42 includes an aperture 44 dimensioned for the passage of the driveshaft. The cover plate 42 is removably attached to the gear housing primary section 26 a by way of cover plate fasteners 46 such as screws, bolts or equivalents, which pass through cover plate apertures 48 , and into corresponding gear housing apertures 50 in the gear housing primary section 26 a . In addition, the cover plate 42 is attached to the gear housing removable section 26 b by way of conventional fasteners 46 such as screws, bolts or equivalents, which pass through cover plate apertures 48 , and into corresponding gear housing apertures 52 in the gear housing removable section 26 b.
Some centrifugal superchargers employ the existing lubrication system of the host engine for the supercharger lubrication. However, there exist several advantages of having a self-contained supercharger lubrication system, wherein the supercharger's lubricating fluid is separate from the engine's lubricating fluid. One advantage of a self-contained lubrication system is simplification and ease of installation. Some existing supercharger self-contained lubrication systems utilize a splash system wherein one or more gears are dipped into an oil bath. However, these designs suffer from the disadvantage that built-up heat cannot be discharged.
Referring again to FIG. 2A , according to another embodiment of the present invention, lubrication reservoir 28 is self-contained within the gear housing 26 such that the supercharger 10 does not require lubrication to be drawn from an external source, such as the engine 14 . Additionally, in another embodiment of the present invention, the lubrication reservoir 28 is preferably separate and detachable from the gear housing 26 , thereby reducing service and repair costs. Lubrication reservoir 28 further includes at least one lubrication inlet 54 and at least one lubrication outlet 56 . The lubrication is preferably either in the form of oil, such as engine oil, or in the form of an oil-air mist delivered by appropriate means such as an atomizer (not shown). Advantageously, in a preferred embodiment, hot lubricating fluid is drained into the lubrication reservoir 28 via the lubrication inlet 54 and allowed to cool before being recirculated.
Some superchargers provide an air-assist approach to augmenting lubricating oil circulation within the supercharger gearcase. Generally, the air assist approach results in an air-oil mist lubrication, which aids in achieving reliable operation and the minimization of bearing assembly failure.
In one embodiment of the present invention, the supercharger 10 preferably includes an air assist approach, wherein compressed air from the supercharger 10 is introduced into the lubricating oil by use of a mixing air-assist nozzle assembly (not shown). Such an air-assist assembly may be similar to one described in U.S. Pat. No. 6,293,263. In operation, engine oil, under pressure, mixes with supercharger discharge air, also under pressure, and introduces an air-oil lubricating mist into the supercharger. The lubricating mist is preferably directed towards the supercharger 10 internal gear, shaft, and bearing components.
One advantage of using an oil/air mist is that the oil can be readily sprayed onto the gears and bearings, thereby maximizing gear and bearing life. Further, the pressurized air atomizes the oil and improves distribution and also assists in driving the oil out of the gear housing 26 after use (and into the lubrication reservoir 28 ), thereby minimizing the oil cycle time in the gear housing 26 , and providing improved lubrication and cooling of the gears and bearings.
Referring to FIGS. 2A , and 2 C-D, some embodiments of the present invention may include a reservoir 28 having a reservoir baseplate 29 that may include inlet and outlet ports 32 for the circulation of cooling fluid or water. As shown in FIG. 2D , such an embodiment incorporates passageways communicating with the inlet and outlet ports 32 , but that do not communicate with reservoir 28 . The passageways supply cooling fluid to the heat transfer elements 35 , that are in contact with any lubricating oil within reservoir 28 . The cooling fluid can be provided from a variety of sources including the engine cooling system, or in the case of a marine application, lake or sea water. Advantageously, as shown in FIGS. 2C-D , the heat transfer elements 35 , are attached-to or cast-into the baseplate 29 and provide improved cooling performance.
Referring now to FIGS. 3A-D , the precision bearing fit and alignment required for high-speed supercharger operation is often difficult to maintain. One problem stems from the intrinsic difference in the coefficient of thermal expansion (CTE) between the bearing assemblies, which are typically ferrous-based, and the gear housing, which is usually made of aluminum. For example, the CTE for aluminum is relatively high (0.00001244 unit length change, per degree Fahrenheit) when compared to ferrous materials such as cast iron (0.00000655), carbon steel (0.00000533), and 440C stainless steel (0.0000056). Most bearing assemblies, such as those used by the present invention, are comprised of steel or ceramic (Silicon Nitride) rolling elements, retained in angular position and alignment by a cage, and interposed between inner and outer steel races. Typical material of the steel races would be SAE52100 ferrous-based steel, although other ferrous-based materials may be used including 440C, and martensitic Chromium steels with homogeneous carbonitride microstructure.
As shown in FIGS. 3A-D , according to another aspect of the present invention, an intermediate member, sheath, or sleeve 60 is disposed around the impeller shaft bearing assemblies 40 a , 40 b . Sleeve 60 preferably comprises a ferrous-based material having a CTE that is substantially similar to the CTE of the bearing assemblies 40 a , 40 b . According to some embodiments, the CTE of the sleeve preferably includes a CTE that may range between about 0.000004 and about 0.000007 in/in-° F. (i.e., 4.0×10 −6 , and 7.0×10 −6 in/in-° F.). Suitable ferrous-based materials for the sleeve 60 include, but are not limited to, grade G2 gray iron, DURA-BAR®, free-machining steels such as 12L14, and all other ferrous-based materials having a CTE that is substantially similar to the CTE of the bearing assemblies 40 a , 40 b (DURA-BAR is a registered trademark of Wells Manuf. Co. of Skokie, Ill.).
As shown in FIGS. 3A-D , the sleeve 60 includes an opening 62 for gear engagement. Additionally, the sleeve 60 includes a lubrication conduit 64 in fluid communication with a lubrication oil supply conduit 51 , and lubrication apertures 65 in fluid communication with lubrication conduit 64 . Lubricating oil may then drain back to reservoir 28 via drain port 66 , which is aligned to be in communication with port 54 (shown in FIG. 2A ). It will be appreciated that the sleeve, or sheath 60 may comprise any configuration that results in the sleeve, or intermediate member being positioned between the bearing assemblies 40 a , 40 b and the gear housing 26 . The intermediate-member may also be comprised of more than one component.
According to some embodiments, the intermediate member, or sleeve 60 is pressed or shrink-fitted into the gear housing 26 . In other embodiments, sleeve 60 may be installed with a clearance fit into housing 26 , and retained thereto by a fastener, or other suitable device.
Referring now to FIG. 3D , in the illustrated embodiment, a replaceable shaft-bearing cartridge 68 comprises sleeve 60 , bearing assemblies 40 a , 40 b , and impeller shaft 20 . The shaft-bearing cartridge 68 installs into supercharger primary section 26 a with a slight clearance fit, resulting in an annular gap 67 , interposed between sleeve 60 and primary section 26 a . In one embodiment, the annular gap 67 may range from about 0.0015 inch to about 0.0002 inch. This gap may change with any change in temperature of the sleeve 60 or the primary section 26 a.
In a preferred embodiment, lubricating oil, supplied under pressure via conduit 51 , which is in communication with conduit 63 , is forced into annular gap 67 and creates a hydrostatic supporting force, which reacts to gear loads during supercharger 10 operation. Advantageously, this hydrostatic load supporting mechanism also promotes vibration damping characteristics, resulting in quieter operation of the supercharger 10 .
One feature of the sleeve 60 is that it maintains the bearing assemblies 40 a , 40 b securely in the gear housing 26 during a range of supercharger 10 operating temperatures. More importantly, the fit between bearing races 40 a , 40 b and sleeve 60 are maintained regardless of operating temperature. This is achievable because the CTE's of the sleeve 60 and the bearing assemblies 40 a , 40 b are substantially matched, thereby expanding and contracting in unison. This feature is especially beneficial to the high-speed impeller shaft 20 bearings 40 a , 40 b , which may operate at speeds exceeding 60,000 RPM. It will be appreciated that a sleeve(s) 60 may also be placed around the driveshaft bearing assemblies 38 a , 38 b.
Referring now to FIG. 3C , the shaft-bearing cartridge 68 may be employed as an insertable device that lends itself to manufacturing and assembly advantages in addition to the aforementioned thermal stability advantage. For example, the shaft-bearing cartridge 68 permits pre-assembly which allows it to be inserted and/or removed as a single unit, thereby reducing service and repair costs. Additionally, the use of a pre-assembled, replaceable shaft-bearing cartridge 68 allows repairs to be performed in the field.
Referring to FIGS. 4C-D , superchargers can experience very fast drive- and impeller shaft acceleration rates. The acceleration rates are amplified by the step-up ratio between the driveshaft 12 and the impeller shaft 20 , which is typically in the range of 3:1 to 5:1 (i.e., 3 to 1 and 5 to 1). That is, the impeller shaft 20 may rotate five times faster than the driveshaft 12 . High acceleration and deceleration forces, generally caused by “blipping” the engine, can stress the impeller shaft 20 and its related components, and cause de-stabilizing effects of bearings 40 a , 40 b , sufficient to cause catastrophic failure. However, the most severe stresses and bearing instabilities generally occur during the transition from very high to relatively slow impeller shaft 20 rotational speeds. An extreme example would be a very rapid rotational acceleration immediately followed by a very rapid deceleration. Such an acceleration rate with the peak point of destabilization is depicted in FIG. 4C .
Again referring to FIGS. 4A and 4B , according to another feature of the present invention, the supercharger 10 preferably includes a disengagement device 70 for disengaging the impeller 22 from the engine 14 . In the illustrated embodiment, the driveshaft 12 is disengageable from the engine 14 . As best seen in FIG. 4B , the disengagement device 70 is disposed between the driveshaft 12 and the primary drive pulley 72 . According to some embodiments, the disengagement device 70 comprises a one-way clutch, such as a sprag, overrunning clutch, or other suitable device. In a preferred embodiment, the disengagement device 70 is preferably integrated into the primary drive pulley 72 , which may also comprise part of belt and pulley system 16 , as described in FIG. 1 .
As shown in FIG. 4B , in a preferred embodiment, the disengagement device 70 comprises a sprag clutch 71 located between the primary drive pulley 72 and the driveshaft 12 . A sprag clutch employs sprags (not shown), that due to their oblong shape, wedge between driveshaft 12 and the outer sprag bearing race 78 , when rotation occurs in a first direction, but allow driveshaft 12 and outer sprag race 78 to move independently of each other when rotation occurs in the opposite direction. Furthermore, upon rapid deceleration of the primary drive pulley 72 rotational speed, the sprag clutch 71 disengages and allows driveshaft 12 , drive gear 30 , impeller shaft 20 , and impeller 22 to overrun and gently coast to a reduced rotational speed. As shown in FIG. 4D , the feature of the present invention dramatically reduces the peak destabilizing event, or rapid deceleration. The wedging action of the sprags locks driveshaft 12 and the outer sprag bearing races 78 together, thereby enabling the transfer of rotational force, or torque between the engine 14 and the driveshaft 12 .
By way of example, a FORMSPRAG® sprag clutch (part number CL42875) can be used as the clutch in the present invention (FORMSPRAG is a registered trademark of Dana Corporation of Toledo, Ohio). Of course, other types of clutches, including, but not limited to roller clutches, spring clutches, centrifugal clutches, friction clutches, non-friction clutches, mechanical clutches, pneumatic clutches, hydraulic clutches, electrical clutches, diaphragm clutches and hysteresis clutches, can be employed without departing from the scope of the present invention. It will be appreciated that the disengagement device 70 may be located anywhere between the engine 14 and the impeller 22 . For example, the disengagement device 70 may be located between the driveshaft 12 and the impeller shaft 20 , or between the impeller shaft 20 and the impeller 22 .
According to other embodiments, the disengagement device 70 may comprise a speed-sensitive engagement mechanism such as a traditional centrifugal clutch. Alternatively, the disengagement device 70 may comprise both a speed-sensitive engagement feature and an overrunning or disengaging feature. Advantageously, the speed-sensitive engagement feature permits the supercharger 10 to be substantially disengaged from the engine 14 during very low speed operation and engine idle, when supercharger 10 noise maybe objectionable.
High-performance superchargers (such as for competitive drag racing applications) require high rotational speeds that create high air-flow and pressure ratios, thereby creating significant rotordynamic problems and challenges. One such problem is the inherent lack of stiffness at the impeller-to-impeller shaft shoulder connection point. In a typical supercharger, the impeller abuts against a spacer, which in turn abuts against a shoulder on the impeller shaft. The diameter of the impeller shaft shoulder is normally only slightly larger than the diameter of the impeller shaft, thereby resulting in a relatively low bending stiffness in the region between the impeller and the adjacent support bearing. Low stiffness in this region may result in impeller shaft bending at rotational speeds that are within the range of the supercharger's high-speed operation, giving rise to rotordynamic critical speeds, identified by dynamic instabilities and/or excessive vibration. Excessive impeller shaft bending and associated dynamic instabilities frequently results in the impeller contacting the compressor housing, causing catastrophic failure of the impeller.
Referring to FIGS. 5A and 5B , another feature of the present invention is illustrated. A spacer assembly 80 is disposed around the impeller shaft 20 between the impeller 22 and the impeller shaft inner bearing race 81 . The impeller shaft 20 comprises a distal section 20 a , which is adjacent to the impeller 22 , and has a first diameter. A proximal section 20 b is adjacent to the impeller shaft inner bearing race 81 , and has a second, larger diameter. The first and second impeller shaft sections 20 a , 20 b meet at a transition section 20 c . The spacer assembly 80 comprises a tubular spacer 84 disposed between the impeller 22 and the transition section 20 c and an impeller spacer 82 disposed between the tubular spacer 84 and the base of the impeller 22 . The two spacers 82 , 84 mechanically couple the distal impeller shaft section 20 a to the impeller shaft inner bearing race 81 , resulting in a much stiffer construction and a significant reduction in vibration between components. Put differently, the tubular spacer 84 adds additional support to the distal impeller shaft section 20 a by contacting, and supporting the impeller spacer 82 at a diameter that is approximate to the diameter of the impeller shaft inner bearing race 81 .
As best seen in FIG. 5A , transition section 20 c preferably comprises a curvilinear taper providing a gradual transition between the first and second impeller shaft sections. In the illustrated embodiment, transition section 20 c is substantially concave. However, as would be understood to those of ordinary skill in the art, transition section 20 c may also be substantially convex or substantially straight, without departing from the scope of the present invention. Advantageously, the transition section 20 c is configured to significantly reduce impeller shaft stress at critical rotational speeds. More particularly, the tubular spacer 84 allows the transition section 20 c to be shaped in a preferred configuration, e.g., a fillet with generous radius, thereby dramatically increasing the fatigue resistance of the impeller shaft 20 . This is because the transition section 20 c can be shaped to minimize localized stresses, thereby eliminating or minimizing the formation of fatigue cracks.
Referring now to FIG. 5B , other advantages of replaceable shaft-bearing cartridge 68 become apparent. In this preferred embodiment, bearings 40 a , 40 b are of the angular contact type, and are mounted as duplex tandem pairs, known in the art as “DT”, with the pairs, in turn mounted “back-to-back” to each other. Bearings 40 a are firmly retained to impeller shaft 20 proximal section 20 b by retaining washer 86 and threaded fastener 87 , which engages a mating threaded receptacle in proximal section 20 b . Bearings 40 b are retained by spacers 84 , 82 , impeller 22 , washer 88 and impeller fastener 89 , which engages a mating threaded portion of distal section 20 a . Preferably, a static preload force should be applied in order to maintain stability of 40 a , 40 b . Preload is provided by spring elements 83 , which generate a preload force against retainers 85 . In this preferred embodiment, the preload force may range from about 50 lbf to about 400 lbf.
Alternative embodiments are also possible, and these are described and incorporated herein as within the scope of the present invention. In one such embodiment, angular contact bearings 40 a , 40 b may be configured as rigidly preloaded duplex sets, and mounted either back-to-back (known in the art as “DB”) or face-to-face (known in the art as “DF”). Advantageously, the clamping forces acting on bearings 40 a , 40 b inner races are developed by threaded fastener 87 and impeller fastener 89 , which in turn enable the rigid preloading of bearings 40 a , 40 b.
Referring now to FIGS. 6A and 6B , high performance superchargers often have air, or gas flow rates that exceed 200 lbm/min. and pressure ratios exceeding 3.0 (i.e., pressures greater than three times ambient atmospheric pressure). Of course, this places extraordinary demands on most centrifugal superchargers and their associated impellers. Proper impeller design is critical for the overall performance of the supercharger. A primary impeller design challenge involves attaining sufficient airflow performance without resorting to undesirable designs. An example of an undesirable design is an impeller having excessively large passageways, which preclude aerodynamic choke, but result in poor blade loading and other deleterious effects.
On one hand, it is desirable to have a low blade count at the impeller inlet to decrease aerodynamic blockage and increase airflow. On the other hand, in order to increase impeller efficiency, a high blade count is preferred further along the airflow passageway (especially near the impeller outlet). Such a design allows the specific impeller work (e.g., total work per unit blade) to be reduced, thereby reducing blade loading effects to more efficient levels.
Referring to FIGS. 6A and 6B , another feature of the present invention is illustrated. An impeller 22 suitable for use with the supercharger 10 is shown. Impeller 22 preferably comprises at least three sets of blades including primary blades 22 a , secondary blades 22 b , and tertiary blades 22 c . In the illustrated embodiment, the impeller 22 comprises a set of primary blades 22 a having a first height, a set of secondary blades 22 b having a second height, and a set of tertiary blades 22 c having a third height. The blade heights are configured such that the first height is greater than the second height, which is greater than the third height. As would be understood to those of ordinary skill in the art, the impeller 22 may consist of additional or fewer sets of blades having different heights without departing from the scope of the present invention.
As depicted in FIG. 2A , air or other gasses are drawn into the impeller through opening 24 a in the compressor housing 24 . Referring to FIG. 6B , the air enters the impeller 22 through the inlet region 90 , which has a relatively low blade count since the secondary blades 22 b and tertiary blades 22 c do not extend up to the top of the impeller 22 . The air is compressed as it travels through a middle region 92 having a relatively medium blade count and a lower region 94 having a relatively high blade count since all three sets of blades extend through this region.
Specifically, in a preferred embodiment (as shown in FIGS. 6A and 6B ) of the present invention, the impeller 22 would include five primary blades 22 a , five secondary blades 22 b , and 10 tertiary blades 22 c . Alternative embodiment impellers 22 may have a range of 3 to 9 primary blades 22 a , with 3 to 9 secondary blades 22 b , and 6 to 18 tertiary blades 22 c . It will be appreciated that other blade numbers and/or arrangements may be employed without departing from the scope of the present invention.
One feature of this aspect of the invention is that the relatively low blade count within inlet region 90 induces a low density air flow that minimizes aerodynamic blockage. Conversely, the relatively high blade count within outlet region 96 provides excellent aerodynamic performance by minimizing blade loading.
Referring now to FIGS. 7A and 7B ; centrifugal compressors for superchargers commonly employ an exit assembly such as a compressor housing or volute. Compressor housings are often complex structures that pose both design and manufacturing difficulties. By 10 way of example, one manufacturing problem involves providing access to the inner flow path passage for cleaning (e.g., polishing) and/or maintenance. Other manufacturing problems relate to installing and supporting the core in the mold when casting the compressor housing. Complex cores result in unacceptably high reject rates, but simpler cores limit design options in the critical diffuser region.
As shown in FIGS. 7A and 7B , another feature of the present invention is illustrated. A modular compressor housing 24 suitable for use with the supercharger 10 is depicted. The modular compressor housing 24 comprises at least two modular components as opposed to a single casting. In the illustrated embodiment, modular compressor housing 24 comprises three modular components including a main housing or scroll 98 , a shroud 100 and a backplate 102 . As an assembly, shroud 100 and backplate 102 form an annular space or diffuser passageway 104 . Alternatively, two of the three components can be combined into a single component, thereby forming a, modular compressor housing 24 having two components. For example, the shroud 100 and scroll 98 may be combined into a single component.
As shown in a preferred embodiment of FIG. 7A , diffuser passageway 104 is curved approximately 45° toward the axial direction, resulting in a more compact overall dimension of compressor housing 24 . Advantageously, curved diffuser passageway 104 affords a reduction in compressor housing 24 dimension without unduly shortening the length of diffuser passageway 104 . Shortening the length of the diffuser passageway reduces the maximum pressure recovery attainable from the diffuser, which deleteriously affects performance of the compressor stage. The amount of curvature toward the axial may range from 20° to 60° without departing from the scope of this feature of the invention.
Referring to FIG. 7B , shroud 100 may be cast and machined separately and attached to the main housing 98 using fasteners such as screws, bolts, or other suitable fasteners. The backplate 102 may be attached to the main housing 98 by way of force-fit or friction fit, thereby covering the shroud 100 . Alternatively, the backplate 102 may be attached using suitable removable fasteners. Advantageously, by removing the backplate 102 and shroud 100 components, the interior of the compressor housing 24 is accessible for blending, de-burring, polishing, cleaning, and/or maintenance. Additionally, the compressor housing 24 may incorporate alternative diffusers including, but not limited to, vaneless diffusers, channel or wedge diffusers and low-solidity vane diffusers. Advantageously, the modular design of the compressor housing 24 permits different diffusers to be installed, thereby enabling compressor “tuning.” This reduces the number of parts that must be maintained in stock, thus reducing costs. Also advantageously, the modular design affords ease of manufacture of the curved diffuser passageway 104 .
Thus, it is seen that a centrifugal supercharger is provided. One skilled in the art will appreciate that the present invention can be practiced by other than the above-described embodiments, which are presented in this description for purposes of illustration and not of limitation. The description and examples set forth in this specification and associated drawings only set forth preferred embodiment(s) of the present invention. The specification and drawings are not intended to limit the exclusionary scope of this patent document. Many designs other than the above-described embodiments will fall within the literal and/or legal scope of the following claims, and the present invention is limited only by the claims that follow. It is noted that various equivalents for the particular embodiments discussed in this description may practice the invention as well. | A centrifugal supercharger is provided. One embodiment of the supercharger comprises a two-piece housing wherein a parting area is substantially aligned with a rotational axis of a drive- or impeller shaft. Another embodiment comprises a sleeve, or intermediate member disposed substantially between the housing and a bearing assembly(s) located within the supercharger housing. Another embodiment comprises a disengagement device located between the supercharger impeller and the engine. The disengagement device allows selective disengagement of the impeller from the engine. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the subject matter of the disclosure contained therein. This Abstract is submitted with the explicit understanding that it will not be used to interpret or to limit the scope or the meaning of the claims. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 61/977,464 filed on Apr. 9, 2014.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to detecting and monitoring biofilm formation within anthropogenic water and other fluid systems to provide information to aid in controlling the operation and treatment of the water or other fluid system.
[0004] 2. Description of Related Art
[0005] Many anthropogenic water or fluid systems, such as cooling towers and boilers, are prone to growth of biofilms. Biofilms contain mixed communities of bacteria that adhere to surfaces, such as pipe walls, of components within the fluid system. The bacteria in underlying layers of biofilms continue to reproduce and create a dense bacterial cluster. As these biofilm layers form they also accumulate other inorganic and organic debris, increasing in size and restricting flow with the fluid system and causing blockages, which can result in increasing operating costs (such as pumping requirements) and maintenance costs for the fluid system. Various chemical treatments and biocides are known to be added to such fluid systems to remove biofilms and aid in controlling growth and recolonization. Effective treatment to remove biofilms and to prolong the amount of time before the fluid systems are re-contaminated can save significant amounts of money. An effective and thorough treatment may save costs for labor and treatment chemicals by reducing the frequency of periodic treatments or reducing the amount of chemicals needed for routine maintenance and/or periodic treatments. Such a treatment may also save on energy costs through the operation of clean heat exchange surfaces and reduce the amount of bleed-off/make-up cycles to remove contaminated water and replace it with fresh water.
[0006] In order to effectively control and treat biofilms in fluid systems, it is beneficial to be able to monitor the growth of biofilms within the fluid system. Some fluid systems are on a periodic treatment schedule without any means of detecting biofilms, which results in treating the fluid system when not needed. This can be costly and can result in unnecessary damage to components of the fluid system since many biofilm treatments are acidic or corrosive. Some fluid systems rely on visual inspection of components to determine the presence of biofilm growth. This can make it difficult to detect the presence of biofilms in areas of the fluid system that are not easily inspected by visual means.
[0007] It is also known to use an automated monitoring system to monitor for biofilm growth or other types of contaminants in a fluid system. For example, US Patent Application Publication No. 2013/0344533 discloses a “scaffold” structure biosensor with an embedded dye/clay mixture. A portion of water is withdrawn from the fluid system and enters a “dampening basin” upstream of the biosensor to achieve laminar flow over a scaffold structure biosensor. If microorganisms are present, there is a reaction with the dye embedded in the scaffold and a signal detection unit may be used to detect a change in color. The disadvantages of such a monitoring system include that preparation of the dye/clay mixture embedded in the sensor scaffold is difficult and requires replacement of the entire biosensor structure when replenishment is needed. Additionally, it appears that the flow of sample water is continuously exposed to the dye/clay mixture, which would cause the dye to be consumed more quickly and increases maintenance time and costs. Finally, it appears that the sample water is in an open biosensor structure where it could be contaminated by external contaminants.
[0008] Another automated monitoring system and method is disclosed in U.S. Pat. No. 7,190,457. The system described in the '457 patent uses multiple optical probes to obtain signals indicating biofilm growth and can differentiate between bulk or suspended bacteria and biofilm growth. The system in the '457 patent can be used externally to the fluid system, with an isolated sample of fluid disposed on a representative substrate, such as glass or metal, or it can be used by directly inserting the optical probed into the flow of fluid within the fluid system. The disadvantage of the external configuration is that it requires removal of samples from the fluid system and is not as accurate as a measurement of fluid flowing through the fluid system. The disadvantages of the direct application are that it requires waterproof components and does not take advantage of any laminar flow characteristics in the area where the test is being conducted.
[0009] None of the known prior art references disclose a closed biofilm monitoring or detecting system for use in-line with a flowing fluid system that uses a dye that is injectable at the time of or near the time of measuring or detecting biofilm growth, that does not require waterproof light source or optical detector components, and that incorporates laminar flow characteristics in the area to be tested. There is a need for a simple monitoring system that can be easily added on to existing fluid systems and that is capable of automated, in-line monitoring for biofilm growth and automated control of operational parameters of the fluid system in response to detected biofilm growth.
SUMMARY OF THE INVENTION
[0010] This invention provides a system and method for real-time detection and monitoring of biofilm formation within anthropogenic water and other fluid systems, such as a cooling tower or boiler system, to provide information to aid in controlling the operation and treatment of the water or other fluid system. A monitoring or detecting system according to a preferred embodiment of the invention comprises a narrow lumen tube through which a portion of water or fluid from the fluid system is diverted and flows and into which an amount of bio-reactive dye is periodically injected. The narrow lumen tube passes through a sensor comprising a light source and optical detector that periodically measures a light transmission or emission corresponding to growth of a biofilm within the tube. The use of a narrow lumen tube allows for laminar flow through the test or measurement area at the sensor, which is characterized by the flow rate of water or other fluid being at its maximum velocity through the center of the lumen and being virtually zero at the lumen walls (the hydrodynamic boundary layer). The physics of laminar flow allow microbial adhesion and subsequent biofilm formation on the inner walls of the narrow lumen tube, resulting in biofilm growth in the monitoring or detecting system that corresponds to biofilm growth or favorable biofilm growth conditions within the fluid system, The biofilm growth in the narrow lumen tube would grow faster than expected in most parts of the fluid system. Depending on the level of growth of biofilm in the narrow lumen tubing, the monitoring and detecting system may indicate when conditions in the fluid system favor biofilm growth or may indicate that biofilm growth is already occurring in the fluid system. Thus the monitoring and detecting system can provide early warning or indication of a potential biofilm issue in the fluid system or the likely existence of actual biofilm in the fluid system.
[0011] According to another preferred embodiment of the invention, a bio-reactive dye is periodically injected into the narrow lumen tube through which the fluid to be tested flows. A preferred dye is Erythrosine, which selectively binds to bacterial cells. Dye is only injected at or near the time a measurement is made using a light source and optical detector that detects a transmission or emission of light through the tube or from the dye within the tube. This configuration conserves the amount of dye used in the system. According to another preferred embodiment, the monitoring system comprises a dye reservoir for containing the dye to be injected, a control valve that periodically opens and closes to release an amount of dye from the reservoir, and a venturi injector that injects the released dye into a tube through which the fluid to be tested is flowing.
[0012] According to another preferred embodiment of the monitoring system, the fluid to be tested flows through the monitoring system, the level of biofilm growth is measured, and the fluid is returned to the fluid system. During normal operations of the fluid system and monitoring system, fluid continuously is withdrawn from the fluid system, flows through the monitoring system and is returned to the fluid system. The fluid is only measured for detection of biofilm growth at certain intervals, which may be at predetermined and preprogrammed time intervals, when a measurement or the difference between two measurements is above a predetermined threshold, and/or when a manual entry is made to initiate a measurement. Continuously flowing fluid through the monitoring system simulates the flow of fluid through the fluid system, giving the same amount of time for growth of biofilms in the monitoring system as in the fluid system to achieve more accurate measurements corresponding to, the level of growth on components in the fluid system.
[0013] According to another preferred embodiment of the invention, the monitoring system comprises a plurality of interchangeable, narrow lumen tubing segments. Preferably, these tubing segments would be in a pre-cut format with quick connects for easy install and replacement. According to another preferred embodiment, the monitoring system comprises a housing having inlet and outlet bulkhead fittings that are connectable to tubing or piping in the fluid system to allow a portion of fluid from the fluid system to flow through the monitoring system and then be returned to the fluid system. The narrow lumen tubing segments and inlet and outlet bulkhead fittings preferably have quick connect features allow easy connection of the components to allow fluid to flow from the fluid system, through the monitoring system for measurement and then back to the fluid system, making installation and replacement of tubing easy.
[0014] According to another preferred embodiment, a monitoring system is configured to detect the transmission or emission of light from one or more light sources through the fluid flowing in the narrow lumen tube or from a compound or dye injected into the fluid in the narrow lumen tube using one or more optical detectors. A light source and an optical sensor are configured relative to the narrow lumen tube to measure the transmission or emission of light through or from the fluid in the tube. Data or signals from the optical sensor or sensors indicate a level of biofilm growth within the narrow lumen tubing that corresponds to a level of biofilm growth in various parts of the fluid system.
[0015] According to yet another preferred embodiment, a monitoring system comprises an display and user interface that provides information regarding the measured or calculated level of biofilm growth and allows a user to input data and instructions into the monitoring system and/or any control system for the fluid system that is connected (by wired or wireless connection) to the monitoring system, such as instructions to run a high resolution test or instructions to add treatment products to the fluid system.
[0016] According to another preferred embodiment, a monitoring system comprises a controller with processing capabilities that allow it to send and receive signals, make calculations, display data, store data and/or save data to a removable memory card or other connected device, and process one or more tests that are selected by a user (such as a low resolution or high resolution test). A preferred controller is configured to interact with a light source, optical sensor, dye injector system, and a display and user interface. According to another preferred embodiment, a controller is also capable of automatically sending signals to alter one or more operating parameters of the fluid system, making recommendations for altering operating parameters, and accepting manual input of operating parameter changes and sending signals to other devices or equipment to carry out the manually input changes, in order to control operation of the fluid system. The information provided by the monitoring system may be displayed on a screen on the monitoring system housing, thereby allowing the user to make manual changes to the fluid system based on the information, such as manually adjusting a valve, to manually input instructions into the sensing system meter which are then sent to other devices or equipment or to manually input instructions into a separate electronic control system to make changes to the fluid system based on the information. The information may also be communicated to a separate or remote control system, directly (through a plug-in connection) or by wireless communication, to remote users (such as supervisors or remote operators), to achieve automated control over the fluid system. The monitoring system is preferably part of a larger control system with numerous configurations of applied electronics and the ability to communicate data from the monitoring system to computers or other instruments in order to control operation of a fluid system. The operating parameters (such as rate or amount of treatment product(s) added, “fresh” water or fluid added, blowdown, feed or other fluid system adjustments) may be altered (such as by opening or closing valves in the fluid system, operating pumps, or through manual addition of treatment products or chemicals) would be altered if the information indicates a change is needed, such as when the calculated value of biofilm growth falls outside a specified range or is above or below a pre-set threshold value. Additionally, calculated values may be compared and the difference may indicate a need to alter or automatically trigger an alteration in operating parameters for the fluid system, which may improve accuracy in controlling the fluid system.
[0017] According to another preferred embodiment, an alarm signal, such as an audible signal, a visual signal or both, may be generated when a calculated property or value is outside a given range or below or greater than a pre-set value. The alarm signal may be generated by monitoring system and may be communicated wirelessly to a remote control system for the fluid system, computer screen, or user's/supervisor's cell phone or email. According to yet another preferred embodiment, additional alarm signals may also be generated when a calculated level of biofilm growth is within one or more ranges or above or below one or more pre-set values for that property. These additional alarm signals may alert a user when a biofilm level is approaching a value that would require a change in an operating parameter (such as an increase or decrease in treatment product or biocide added to the fluid system) or when the value is at a critical level requiring immediate attention. Preferably, the additional alarm signals are audibly or visually distinct from each other.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The system and method of the invention are further described and explained in relation to the following drawing wherein:
[0019] FIG. 1 is block diagram showing a system for detecting biofilm growth according to a preferred embodiment of the invention;
[0020] FIG. 2 is a simplified diagram of an external display/user interface for a monitoring system according to the preferred embodiment;
[0021] FIG. 3 is a block diagram showing a temperature controlled test configuration for several monitoring systems according to an embodiment of the invention;
[0022] FIG. 4 is a graph showing the results of a viability assay to determine biofilm density in sections of narrow lumen tubing in an experiment using three monitoring systems according to a preferred embodiment;
[0023] FIG. 5 is a graph showing the results of a viability assay to determine biofilm density in sections of narrow lumen tubing in a second experiment using three monitoring systems according to a preferred embodiment;
[0024] FIG. 6 is a graph showing the results of a viability assay to determine biofilm density in sections of narrow lumen tubing in a third experiment using three monitoring systems according to a preferred embodiment;
[0025] FIG. 7 is a graph showing the output from optical sensors in the three monitoring systems used in the third experiment showing increase in signal corresponding to increase in biofilm thickness.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] Referring to FIG. 1 , a preferred embodiment of a biofilm detecting or monitoring system 10 is depicted in simple, block diagram form. Biofilm detecting or monitoring system 10 preferably comprises a housing 12 , a controller 14 , a sensor housing 16 , a dye reservoir 18 , a valve 22 , a venturi 26 , an inlet port 28 , an outlet port 34 , and optionally a USB or other type of port 28 for transmission of data received by the controller 14 from a sensor within sensor housing 16 . Monitoring system 10 also preferably comprises a plurality of tubing or conduit segments, such as 20 , 24 , 30 , and 32 connecting various components as further described below.
[0027] Housing 12 is preferably a waterproof or water-resistant box having a removable or openable cover or door allowing access to the interior of housing 12 , such as for maintenance or replenishment of the dye in dye reservoir 18 . The controller 14 , sensor housing 16 , dye reservoir 18 , valve 22 , and venturi 26 are all preferably disposed within housing 12 so they are protected from exposure to water or other fluid from the fluid system or other environmental impacts. Housing 12 also preferably has mounting structure that allows the monitoring system 10 to be mounted or otherwise securely attached to an existing structure (such as a wall) around the fluid system to be tested, preferably near the point where a portion of fluid is withdrawn from the fluid system and diverted to the monitoring system 10 .
[0028] A portion of the fluid flow through the fluid system may be withdrawn from a side stream fluid source (such a coupon rack for example) or from a main line of circulation or fluid flow through the fluid system, depicted in FIG. 1 as line 42 , and diverted to the monitoring system 10 through tubing (or piping) 44 . Tubing 44 is connected in fluid communication with inlet port or inlet bulkhead fitting 28 , which is also directly connected to venturi injector 26 . Alternatively, venturi injector 26 could be connected to inlet port 28 by a length of tubing. On a downstream side of venturi injector 26 is tube or tubing 32 , which is preferably a narrow lumen tube having a high internal surface area to volume ratio and configured such that, at a constant flow rate through the tubing 32 , the velocity of the moving fluid varies from virtually zero at the lumen walls (the hydrodynamic boundary layer) to a maximum flow rate along the center line of tube 32 . Most preferably the internal diameter of tube 32 is between about 1 mm to about 20 mm, but other sizes may also be used. Tube 32 passes through sensor housing 16 and is connected on a downstream side of sensor housing 16 to outlet port or outlet bulkhead fitting 36 . Tubing 40 is connected in fluid communication with outlet port 36 to return the fluid from monitoring system 10 back to line 42 of the fluid system. Inlet port 28 and outlet port 36 and venturi injector 26 preferably are threaded or have quick-connecting fittings allowing tubing to be quickly and easily connected or disconnected. Although it is preferred to return the fluid tested in monitoring system 10 to the same source or line 42 from which the fluid was withdrawn, tubing 40 may be connected to any part of the fluid system (preferably downstream from where the fluid was withdrawn for monitoring) to return the fluid to the fluid system. In this way, a portion of fluid from the fluid system continuously flows through monitoring system 10 during normal operations of monitoring system 10 and the fluid system. Valves or other control mechanisms may be added to tubing 44 , tubing 40 , inlet port 28 and/or outlet port 36 to restrict or stop flow of fluid to monitoring system 10 , without necessarily restricting fluid flow through the fluid system, if desired.
[0029] A dye reservoir 18 is also preferably disposed inside housing 12 . Dye reservoir 18 preferably contains a bio-revealing dye that indicates the presence of biological material when exposed to light within sensor housing 16 . The most preferred dye is Erythrosine, but other dyes, such as dental plaque disclosing solution, FDC green number 3, FDC blue number 1, other food dyes and fluorescent dyes or a combination of the foregoing may also be used. A valve 22 is preferably used to control the release of dye from dye reservoir 18 and the dye is injected into the fluid through a venturi injector 26 . Valve 22 is preferably a solenoid valve, but other types of valves may also be used. Dye reservoir 18 is preferably connected in fluid communication with tubing 20 , which is connected to valve 22 and tubing 24 is connected to venturi injector 26 .
[0030] A portion of fluid from fluid system to be tested is diverted to monitoring system 10 through tubing 44 , as previously described. Dye from dye reservoir 18 is periodically injected into the fluid to be tested and then passes through sensor housing 16 in tubing 32 . Sensor housing 16 is preferably a waterproof or water-resistant box having a removable or openable cover or door allowing access to the interior of sensor housing 16 , such as for maintenance or replacement of tubing 32 . Disposed within sensor housing 16 is a light source and an optical sensor or detector, with tubing 32 disposed between the light source and optical sensor in a configuration that allows for detection of optical properties, such as fluorescence of the Erythrosine dye. A light source within sensor housing 16 is preferably an LED emitting light in a wavelength range of 545 to 570 nm. Detection is accomplished using an ambient light sensor (photo transistor), which allows for current to flow through in proportion to the amount of light hitting the base, this current flows through a resistive network to a corresponding output voltage base. The output data (or signal) from the light sensor (or optical sensor) will be processed by controller 14 , which will read real time and log at programmable intervals for dynamic data acquisition and evaluation. Other sensors, such as a phototransistor or photodiode, may also be used as an optical sensor within sensor housing 16 . Other types of light sources, such as laser, incandescent, infrared or ultraviolet light, and other wavelengths may also be used, with corresponding changes in the light sensor as will be understood by those of ordinary skill in the art. Tubing 32 , through which fluid passes, is insertable in fluid communication with venturi injector 26 and outlet port 36 and configured to pass through sensor housing 16 in a manner that allows light from a light source to contact the fluid in tubing 32 and be detected by an optical sensor to obtain a reading indicating the level of biofilm growth within tubing 32 . Most preferably, these components are configured so that light passed is directed at tubing 32 in a direction substantially perpendicular to the direction of fluid flow through tubing 32 . Once a biofilm grows within tubing 32 to a predetermined level, tubing 32 may be removed from monitoring system 10 and replaced with a new piece of tubing 32 to begin the monitoring process over, as more fully described below.
[0031] A controller or microcontroller 14 is also preferably disposed within housing 12 . Controller 14 is connected to an optional external display/user interface 38 , valve 22 , the light source and optical sensor within sensor housing 16 , and optional USB or data port 28 , as shown by dashed lines in FIG. 1 . Controller 14 sends and receives signals or data from the connected components of monitoring system 10 . Controller 14 sends a signal to valve 22 to open and close the valve to allow dye to be periodically injected into the fluid within tubing 32 . Controller 14 also sends signals to a light source within sensor housing 16 to periodically direct light to tubing 32 , which is detected or measured by an optical sensor within sensor housing 16 . That optical sensor then sends a signal or data back to controller 14 , indicating the level, if any, of biofilm growth within tubing 32 . The level of biofilm growth within tubing 32 is indicative of biofilm growth on components of the fluid system. Controller 14 sends information regarding the measurements of biofilm growth to an external display/user interface 38 . One or more data ports 28 are preferably disposed in housing 12 and connected to controller 14 , to allow monitoring system 10 to connect to other devices (such as a computer or server), to an external power source, or to receive removable memory cards. One or more data ports 28 (such as a USB port) allow controller 14 to send or receive data, such as software updates, operational instructions (such as whether to run a low resolution or high resolution test or instructions or data regarding an adjustment to an operating parameter for the fluid system in response to the biofilm measurement), and/or biofilm growth measurements based on signals from the optical sensor. These ports would interact with the controller 14 of monitoring system 10 according to known methods understood by those of ordinary skill in the art.
[0032] Controller 14 preferably has sufficient memory to store readings or measurements from the optical sensor for a period of time. A preferred controller 14 has electrically erasable programmable read-only memory (EEprom) of 256 bytes, with each byte storing 8 bits of information (2 digit hexadecimal number). An analog to digital converter on the controller 14 is preferably a 10 bit module, so that that each measurement will have 10 bits of binary information. Controller 14 and optical sensor in sensor housing 16 are preferably configured to allow operation in a low resolution (or standard) mode and a high resolution mode. In low resolution mode, the A/D measurement is bit shifted to save room on the chip for data logging purposes. When run in high resolution mode, the A/D measurement is split into 2 ‘cells’ of the EEprom, using more space, but quadrupling the resolution. Other configurations and storage capabilities may be use with monitoring system 10 , as will be understood by those of ordinary skill in the art. Controller 14 may be battery powered, connected to an external power source (such as NC power), or both. Battery power provides flexibility in placement of monitoring system 10 , since it would not need to be placed near an outlet or other power source.
[0033] A screen or external display/user interface 38 is preferably located on an outer face of housing 12 in a location that is easily accessible by a user or operator. The external display/user interface 38 preferably comprises a display screen 40 to provide information regarding operation of monitoring system 10 and the level of biofilm growth within tubing 32 . For example, as shown in FIG. 2 , a visual representation of the biofilm formation displayed on screen 46 may include a bar that increases in size as greater deposits are detected and/or a numerical or percentage indication of growth. Screen 46 may also include an alphanumeric status, indicating a level of risk associated with the degree of biofilm growth detected, which may flash if an alarm status is reached to indicate that attention or action is needed. Monitoring system 10 may also include an audible alarm or series of alarms corresponding to increasing levels of biofilm growth detected. Screen 46 may also indicate the status or strength of the battery for monitoring system 10 (if battery powered), display the date and time, and/or other information related to monitoring system 10 , such as a version associated with the equipment or programming for controller 14 . External display/user interface 38 also preferably comprises a plurality of buttons or knobs 48 that allow an operator to input information and/or manually operate various components of monitoring system 10 . Buttons or knobs 48 may alternatively be touch screen type buttons included within display screen 46 . Buttons or knobs 48 (or touch screen) allow a user to provide inputs to monitoring system 10 , such as selection of the particular test to be performed (low resolution or high resolution), changing measuring cycle timing, resetting the system for a new monitoring cycle, recall of stored data from prior tests, or sending electronic data or commands to other devices or components of the fluid system being tested or a control system that controls various components of the fluid system. In conjunction with the controller 14 , the external display/user interface 38 may be programmed for a variety of functions as will be understood by those of ordinary skill in the art.
[0034] When monitoring system 10 is connected to a fluid system, a portion of fluid from the fluid system is diverted to monitoring system through tubing 42 and into tubing 32 . Controller 14 is preferably preprogrammed to periodically initiate a measurement cycle, with multiple measurement cycles being completed within each monitoring cycle. Although other measurement cycle times may be used, a once per day cycle is preferred. A measurement cycle begins with controller 14 sending a signal to open valve 22 to allow dye from reservoir 18 to be injected into the fluid through venturi injector 26 . The suction from the venturi injector 26 is activated when valve 22 is open, allowing a small quantity of dye to be introduced into the water or other fluid that will flow to sensor housing 16 through tubing 32 . In normal operation, valve 22 is open for between ½ a second and 2 seconds once per day and in its non-activated mode is closed, which prevents unintended release of dye and failure of monitoring system 10 if power to the monitoring system 10 is lost. During normal operation of a measurement cycle, controller 14 will turn on a light source (LED) in sensor housing 16 for approximately 60 seconds and check the corresponding voltage at an optical sensor within sensor housing 16 . An analog to digital converter takes the analog voltage and converts it to a 10 bit digital hexadecimal value and makes comparisons to an initial state reading. The first reading or measurement during a monitoring cycle is saved as the initial state or comparison value. As biofilm grows on tubing 32 , the sensor voltage will increase, which causes a greater deviation from the initial value. With each measurement cycle, the results of the measurement and/or comparison to the initial reading are preferably displayed on display screen 46 and stored in memory.
[0035] Controller 14 may also optionally operate a high resolution measurement cycle if biofilm is detected. A high resolution measurement cycle may be preprogrammed to automatically run if biofilm is detected at a predetermined level or may be manually run by selecting or activating a button 48 on external display/user interface 38 . If a reading or measurement during a normal operation measurement cycle indicates the presence of biofilm in tubing 32 , then controller 14 may confirm the presence of biofilm by running a high resolution test where a reading is made immediately before and after dye has been introduced into tubing 32 . Under normal operating conditions, the dye will not impact the voltage change on the optical sensor; but by running a high resolution reading it will be possible to detect small changes associated with the dye changing the color of the biofilm. This high resolution test may be used as a confirmation step to identify the fouling as biofilm and not just mineral deposits. The results of the high resolution test may be displayed as are the results of a normal operation test on screen 46 or may be separately displayed to distinguish between normal operation (low resolution) results and high resolution results. One or more high resolution tests may be run in each monitoring cycle.
[0036] If any measured or calculated result, comparison of results, difference in results, or deviation is out of a pre-determined or pre-set range of desired values or is above or below a pre-determined or pre-set threshold value, then monitoring system 10 may generate an alarm indicating that an adjustment or modification of one or more operating parameters for the fluid system is needed. An alarm may be visual, audible, or both, and may be communicated locally at housing 12 or remotely at another location, such as a control room for the fluid system or via email or text to an operator. Preferably, a warning message, such as an increase in risk level from “low” to “moderate” and ultimately to “high” (although other wording an additional intermediate levels may also be used), is displayed on screen 46 . As the amount of fouling increases during a monitoring cycle, the severity of the warning level also preferably increases. Audible alarms may also be used in place of or in conjunction with visual indicators on screen 46 . Most preferably, an initial alarm within a monitoring cycle is triggered when the difference between the sensor reading and the initial reading reaches around 15% difference. Additional, higher level alarms, are preferably triggered when that difference is around 30%, 50%, and 65%.
[0037] When an alarm is triggered, it indicates that there is biofilm growth within tubing 32 or that the amount of biofilm growth has reached or exceeded a predetermined level, which indicates the presence of biofilm growth (and a similar amount of biofilm growth) on other components of the fluid system. To keep the fluid system operating properly, it is important to treat the fluid system to remove the biofilm and help control re-growth. An alarm triggered by monitoring system 10 indicates that action is needed to adjust one or more operating parameters of the fluid system to treat the biofilm growth. Such adjustments are preferably automatically made when biofilm growth is detected or when a certain level of biofilm growth is detected, in response to an alarm signal from controller 14 . Most preferably, controller 14 is configured to automatically initiate such adjustments by sending signals to the separate control system for the fluid system or by directly sending signals to smart components within the fluid system, such as opening or closing valves to release a dose (or a series of doses) of biocide or other treatment products into the fluid system. Such adjustments may also be performed manually, manually entered into the monitoring system 10 to be communicated to a separate control system for the fluid system to automatically carry out the adjustment commands, or may be manually entered into a separate control system for the fluid system and then automatically carried out by that control system. Other adjustments in operating parameters may include altering the amount of non-biocide treatment products added to the fluid system, adjusting blowdown rate, adjusting fresh-water make-up rate, increasing or decreasing flow rates through the fluid system, or other adjustments as needed to remove biofilm and help control regrowth. Controller 14 also preferably sends an email or text message to designated personnel or computer stations when an alarm is triggered and when any operational adjustments or treatment dosing has automatically occurred.
[0038] Monitoring system 10 can also be used to determine the effectiveness of the adjustments made in treating the biofilm. By continuing to monitor the level of biofilm within tubing 32 , monitoring system 10 can determine whether the operating adjustments are sufficient to remove the biofilm from components in the fluid system. Once the level of biofilm in tubing 32 returns to zero or near zero, a monitoring cycle is completed and a new monitoring cycle begins again. Alternatively, housing 12 and sensor housing 16 may be opened, tubing 32 disconnected and removed and a new piece of tubing 32 inserted to begin a new monitoring cycle. Monitoring system 10 may also be manually reset to initiate a new monitoring cycle. Monitoring cycles are preferably repeated to continuously monitor biofilm growth within the fluid system.
[0039] An embodiment of the monitoring system 10 and method of monitoring biofilm growth was tested at various temperature ranges to confirm the effectiveness of the monitoring system 10 , as well as to determine the impact of temperature on propagation of biofilm and to correlate output signals of the optical sensor to a biofilm growth rate. Three identical monitoring systems (shown as 10 A, 10 B, and 10 C in FIG. 3 ) were connected in series to a 30 gal drum of tap water (to simulate the fluid system), as shown in FIG. 3 . The drum of tap water was inoculated with overnight cultures of Pseudomonas species (5 mL) and Bacillus species (5 mL) in TSB (tryptic soy broth). Each monitoring system comprises a controller and a sensor housing have a light source and optical sensor, as shown in FIG. 1 . The 30 gal drum containing the bacterial latent water was maintained at ambient temperature of about 72° F. and it was used to deliver a constant flow through the entire PVC tubing (e.g. tubing 44 , 32 , and 40 ) for all three monitoring systems 10 A, 10 B, and 10 C. Temperature controlled water baths set at 80° F. and 90° F. were placed between the first and second monitoring systems (between 10 A and 10 B) and between the second and third monitoring systems (between 10 B and 10 C), respectively. The water baths were used to raise the temperature of water flowing through the second and third monitoring systems 10 B and 10 C to simulate the temperature environments that may be encountered in a cooling tower system in the field (as an example of a type of fluid system with which a monitoring system according to the invention could be used). Coiled sections of the PVC tubing were submerged in the temperature controlled water baths to give the internal solution flowing within the tubing enough residence time to equilibrate to the bath temperature while within the respective coiled zones, so the water fed into monitoring system 10 B was around 80° F. and the water fed into monitoring system 10 C was around 90° F.
[0040] Noting the time and date for the start of the experiment, some of the bacteria latent solution was pumped into the monitoring systems to fill the tubing and the water was then allowed to sit stagnant for almost 16 hours to initiate the biofilm growth in the tubing 32 within each monitoring system. The water was then continuously pumped through each monitoring system 10 A, 10 B, and 10 C and recycled back to the drum for a monitoring cycle duration of 16 days. The controller 14 in each monitoring system in this experiment operated 24 measuring cycles per day over 16 days (although other time periods for the monitoring cycle and each measuring cycle could also be used), collecting a low resolution measurement from the optical sensor for each measuring cycle. High resolution tests were not run for this experiment. Erythrosine was used as the dye and injected into the drum, rather than using a dye reservoir and venturi injector for each monitoring system 10 A, 10 B, and 10 C. For comparison to the optical sensor readings and for calibration of those readings, bioassay and microscopic analysis of sections of the narrow lumen tubing 32 from each monitoring system were analyzed. A 2 cm sample section was cut from the narrow lumen tubing 32 in each monitoring system ( 10 A at ambient temperature, 10 B at 80° F., and 10 C at 90° F.) and a thin section of each tube section was isolated for brightfield microscopic analysis. The tubing used for the experiment was long enough to allow sections to be removed for testing and the tubing resected over the course of the experiment.
[0041] Additionally, a viability assay was performed on each section of tubing to determine the biofilm density (Log 10 CFU per cm 2 ) on several days between days 7 and 16 of the monitoring cycle. The results of this viability assay are shown in FIG. 4 . The tubing from monitoring system 10 C at 90° F. showed a markedly higher initial biofilm growth, while the tubing from monitoring system 10 A at ambient temperature and 10 B at 80° F. were tracking similarly and approached the same cell density by Day 16 to within one log. The time and date of each section removal was noted for comparison to the data obtained from the optical sensor and stored on the microcontroller. It was found that the signals from the optical sensor correlated to the increase in biofilm growth to allow calibration of the optical sensor signals to biofilm density.
[0042] Another experiment was conducted using three monitoring systems 10 A, 10 B, and 10 C. Each monitoring system was identical and comprises a controller, inlet and outlet ports, narrow lumen tubing, and a sensor housing have a light source and optical sensor, similar to that shown in FIG. 1 This experiment did not include any temperature modification and the monitoring systems were not connected in series as in the previously described experiment. A biofilm growth promoting solution containing cultures of Pseudomonas species (5 mL) and Bacillus species (5 mL) in TSB (tryptic soy broth) was added to the tubing (e.g. tubing 32 ) in each monitoring system and allowed to sit for 8 hours to initiate biofilm growth. A biofilm revealing dye (erythrosine) was added to the biofilm forming solution at a rate of 3 drops per liter of solution. For purposes of this experiment, the dye was not injected into flowing water through a venturi as previously described with respect to FIG. 1 . After biofilm initiation, tap water at ambient temperature (around 72° F.) was filtered with a granulated activated carbon filter and then continuously pumped through the tubing of each monitoring system for a monitoring cycle of 14 days. The controller 14 in each monitoring system operated 14 measuring cycles, one for each day of the monitoring cycle (although other time periods for the monitoring cycle and each measuring cycle could also be used), collecting a low resolution measurement from the optical sensor for each measuring cycle. No high resolution tests were run in this experiment. For comparison to the optical sensor readings and for calibration of those readings, bioassay and microscopic analysis of sections of the narrow lumen tubing 32 from each monitoring system were analyzed. Five-seven sample sections of 2 cm-3 cm each were cut from the narrow lumen tubing 32 in each monitoring system and a thin section of each tube section was isolated for confocal microscopic analysis and stereoscopic analysis. The tubing used for the experiment was long enough to allow sections to be removed for testing and the tubing resected over the course of the experiment. Using confocal microscopy and special biofilm fluorescent stains, the thickness of the biofilm layer on the PVC tubing segments was measured and recorded. Additionally, a viability assay was performed on each section of tubing to determine the biofilm density (Log 10 CFU per cm 2 ). The time and date of each section removal was noted for comparison to the data obtained from the optical sensor and stored on the microcontroller.
[0043] The results of tubing analysis from this 14 day experiment are shown in FIG. 5 . Another experiment was run with this same set-up and methodology for a 16 day monitoring cycle. The results of the tubing analysis from this 16 day experiment are shown in FIG. 6 . FIG. 7 shows the shows the output from the optical sensors (voltage) from monitoring systems 10 A, 10 B, and 10 C for the 16 day experiment described above. It can be seen that as the thickness of the biofilm in the tube increases the output signal from the sensor increases, which corresponds to the increase in bacterial counts and to the thickness data observed by the confocal microscopy.
[0044] These experiments show that monitoring systems according to preferred embodiments of the invention are capable of bacterial colonization and supporting biofilm growth regardless of temperature of the influent, while also allowing the monitoring systems' optical sensors and controllers to accurately read and track biofilm density over time. Additionally, the use of removable tubing 32 through the monitoring system allows for a measurable method for bioassay and determination of actual cell density, by removal and testing, if so desired.
[0045] References herein to calculating or measuring a value or property and the like are intended to include any form of direct measurement, converting data or a signal, making a calculation based on one or more data points or signals, or otherwise comparing, interpreting, correlating, or manipulating one or more data points or signals. Those of ordinary skill in the art will also appreciate upon reading this specification and the description of preferred embodiments herein that modifications and alterations to the system may be made within the scope of the invention and it is intended that the scope of the invention disclosed herein be limited only by the broadest interpretation of the appended claims to which the inventors are legally entitled. | A system and method for monitoring or detecting a level of biofilm growth in a fluid system and controlling operating parameters of the fluid system based a measured level of growth. The monitoring system and method comprises a dye injection system for periodically injecting dye into a portion of fluid from the fluid system, passing the portion of fluid though a narrow lumen tube to achieve laminar flow and using a light source and optical sensor to detect a transmission or emission indicating a level of biofilm growth in the tube corresponding to a level of growth on components in the fluid system. Information based upon the measurements or calculations made by the monitoring system may be used to manually or automatically alter various operating parameters to control the fluid system and aid in maintaining stable operation of the fluid system within preferred specifications. | 2 |
[0001] This non-provisional application claims the benefit of Provisional Appl. Ser. No. 60/561,864, entitled “FAST PARAMETRIC NON-RIGID IMAGE REGISTRATION BASED ON FEATURE CORRESPONDENCES,” filed on Apr. 12, 2004.
BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to medical imaging, and more particularly, to an efficient deformable registration methodology using a B-spline based free-form deformation model. The method utilizes sparse feature correspondences to estimate an elastic deformation field in a closed form. In a multi-resolution manner, the method is able to permit the recovery of small to large non-rigid deformations, such that the resulting deformation is globally smooth and guaranteeing one-to-one mapping between two images being registered.
[0003] Non-rigid (i.e., deformable) registration is an active and important topic of research in medical imaging. This process has numerous clinical applications, such as, for example, the study of PET-CT chest images and MR kidney perfusion time series, where respiratory motion causes gross changes in shape of the organs. It is employed in computational anatomy to adapt an anatomical template to individual anatomies. It is also used in brain imaging for spatial normalization of functional images, group analysis, and the like. Despite vast research efforts, however, non-rigid registration remains a primarily academic interest, and is not currently used in industry.
[0004] The reasons for the lack of industrial use are varied. State-of-the-art non-rigid registration methods are relatively slow, with running times on a typical workstation on the order of minutes to hours. Furthermore, most non-rigid registration methods do not directly solve the problem of anatomical correspondences. In many registration algorithms, maximum image similarities are pursued, and correspondences are only generated somewhat as a byproduct at the end of the registration. This poses problems when it comes to validation, since correct anatomical correspondences are the ultimate goal of a good registration method, as opposed to the ability and accuracy to transform one image into a clone of the other image. Finally, there is still no widely accepted validation protocol for measuring the quality of a deformation field generated by a registration method. For most available algorithms, no formal justification for the uniqueness of the solution is provided.
[0005] Existing methods for non-rigid registration fall into three general categories: feature-based registration, intensity-based registration, and hybrid methods that integrate the former. Feature based models utilize anatomical knowledge in determining sparse feature correspondences. These can be the faster of the implementations. The well-known disadvantage with this procedure is the need for user interaction to select good features for determining feature correspondences. Compared to rigid-registration, more features are necessary in non-rigid registration in order to recover a dense local deformation field, thus demanding a more automatic and principled method for extracting features, finding correspondences, and estimating elastic deformation. Intensity based methods are much more widely used in non-rigid registration. See, e.g., D. Rueckert, L. I. Sonda, C. Hayes, D. L. G. Hill, M. O. Leach, and D. J. Hawks, “Nonrigid Registration Using Free-Form Deformations: Application to Breast MR Images,” IEEE Transactions on Medical Imaging, Vol. 18, No. 8, pp. 712-721, August 1999. They can be fully automated without prior feature extraction. Typically a dense local deformation field is recovered by optimizing certain energy functions. A regularization term is usually included to explicitly force the smoothness of the deformation field. However, the intensity-based methods do not directly solve the anatomical correspondence problem. Another major concern with this method is that it tends to be very slow. By not discriminating good image elements (e.g., salient anatomical boundary features) from poor ones (e.g., noise, pixels/voxels in homogeneous regions that induce correspondence ambiguity), the cost functions to be optimized are often complex and non-convex, thereby making optimization prone to be stuck in local minima. Hybrid methods aim to integrate the merits of the feature-based and intensity-based models. See, e.g., D. Shen and C. Davatzikos, “Hammer: Hierarchical Attribute Matching Mechanism for Elastic Registration,” IEEE Transactions on Medical Imaging, Vol. 21, No. 11, pp. 1421-1439, November 2002; J. Kybic and M. Unser, “Fast Parametric Elastic Image Registration, IEEE Transactions on Image Processing [need cite]. These have been the subject of greater interest in recent times.
[0006] One important aspect of non-rigid registration is the choice of the local transformation (deformation) model. In the prior art, both parametric and non-parametric models have been considered. In parametric local deformation models, the thin-plate spline model and free form deformation model are most popular. In non-parametric models, elastic deformation and viscous fluid models are commonly employed.
SUMMARY OF INVENTION
[0007] In view of the foregoing, it is an object of the invention to provide a system and methodology that utilizes an efficient non-rigid registration algorithm that can register large volumes of data and time series in real time or near to real time.
[0008] It is another object of the invention to provide a system and methodology that utilizes a non-rigid registration algorithm that provides for a recovered deformation field that guarantees good anatomical correspondences.
[0009] It is yet another object of the invention to provide a system and methodology that utilizes a non-rigid registration algorithm that is easily adaptable to multi-modalities and images of different anatomical structures.
[0010] It is still another object of the invention to provide a system and methodology that utilizes a non-rigid registration algorithm that is robust to image noise, intensity change and inhomogeneity, partial occlusion and missing parts.
[0011] It is yet another object of the invention to provide a system and methodology that utilizes a non-rigid registration algorithm that assures consistent results regardless of which image is treated as the fixed image and which image is treated as the moving image.
[0012] It is still another object of the invention to provide a system and methodology that utilizes a non-rigid registration algorithm that provides for a recovered deformation field that should ideally conform to the actual biomechanical deformations within the tissue of interest.
[0013] It is yet another object of the invention to provide a system and methodology that utilizes a non-rigid registration algorithm that provides for a recovered deformation field that can detect where structure appears or disappears between the fixed and moving images.
[0014] In accordance with an aspect of the present invention, there is provided a system and methodology for non-rigidly registering a fixed to a moving image utilizing a B-Spline based free form deformation (FFD) model. The methodology utilizes sparse feature correspondences to estimate an elastic deformation field in a closed form. In a multi-resolution manner, the method is able to recover small to large non-rigid deformations. The resulting deformation field is globally smooth and guarantees one-to-one mapping between the images being registered. The method generally comprises the steps of: detecting feature points on the fixed image and feature points on the moving image; assigning a feature vector to each feature point; calculating the dissimilarity of each pair of feature vectors for feature pairs on the fixed image and the moving image; calculating the correspondence between feature pairs based on dissimilarity measure: Xi and Xi′; solving for a dense deformation field P using a closed form FFD model; and transforming the moving image and the feature points on the moving image using a current FFD deformation field estimate. In accordance with another aspect of the present invention, there is provided a memory medium containing program instructions which, when executed by a processor, enable a computer to implement the foregoing method.
[0015] These and other advantages of the invention will be apparent to those of ordinary skill in the art by reference to the following detailed description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a schematic of a computer system for carrying out a preferred embodiment of the invention;
[0017] FIG. 2 a is a flowchart of a method in accordance with the invention;
[0018] FIG. 2 b is an exemplary fixed image and a set of feature points thereon;
[0019] FIG. 2 c is an exemplary moving image corresponding to the fixed image depicted in FIG. 2 b and the set of detected feature points on the moving image which correspond to a set of feature points on the moving image; and
[0020] FIG. 3 is a comparison of the recovered space deformation and ground truth deformation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] FIG. 1 depicts an operating environment for an illustrated embodiment of the present invention, comprising a computer system 100 for implementing non-rigid image registration. The system 100 includes a conventional computer 102 , comprising a processing unit 104 , a system memory 106 , and a system bus 108 that couples the various system components including the system memory to the processing unit 104 . The processing unit is of conventional design and includes a typical arithmetic logic unit (ALU) 110 for performing computations, a collection of registers 112 for temporary storage of data and instructions, and a control unit 114 as is well known in the art. The system bus 108 may be any of several types of bus structures including a memory bus or memory controller, peripheral bus, and a local bus using any of a variety of bus architectures. The system memory 106 includes read only memory (ROM) and random access memory (RAM). The system memory 106 further includes a basic input/output system (BIOS) which contains the basic routine that helps to transfer information between elements in computer 102 . The computer 102 further includes data storage 116 which may comprise a hard disk drive, magnetic disk drive, optical disk drive or the like and the appropriate interfaces to the system bus 108 . The drives and their associated computer-readable media provide non-volatile storage of computer readable instructions, data structures, program modules and other data for the computer 102 . A number of program modules may be stored on the hard disk, magnetic disk, optical disk, ROM or RAM, including an operating system, one or more application programs, other program modules, and program data. The application programs may include a computer program 117 adapted for carrying out the methodology of the invention as discussed in greater detail hereinbelow. A user of the system can enter commands via a keyboard 118 coupled to the system bus 108 through a serial or USB interface 120 . The computer may be provided with a network interface 122 to enable networked communication with a remote computer(s) 124 . The remote computer can be a personal computer, server, router, network PC, peer device or other common network node. A display 126 is coupled to the system bus 108 through a video adapter 128 in a conventional manner.
[0022] Referring now to FIG. 2 a , there is depicted a flowchart of a method of using a non-rigid registration algorithm in accordance with an aspect of the present invention to register a fixed image ( FIG. 2 b ) on the computer display ( 125 depicted in Fig. with a moving image on the computer display depicted in FIG. 2 c . In accordance with this method, it is assumed that a proper rigid registration algorithm has been applied to bring the two images into rough spatial alignment. An exemplary rigid registration algorithm is disclosed in the following publication: C. Xu, X. Huang, Y. Sun, C. Chefdhotel, J. Guehring, F. Sauer, V. Sebastion, “A Hybrid Rigid Registration Model for 2D/3D Medical Images,” Invention Disclosure, Siemens Corporate Research, Inc., August 2003, which is hereby incorporated by reference herein. The inventive method consists of picking feature points on the fixed image and assigning a feature vector to each feature point. Good feature points are chosen as those salient regions with the highest local entropy, thus those having the highest complexity and information content. The feature vector can contain geometry, intensity, and further information derived from local image properties. For each feature point (region) on the fixed image, a search is made for its closest counterpart on the moving image, and a correspondence is assumed between them. Since a rigid registration is assumed to have already occurred, this search for correspondences can be constrained in a relatively small search window. To account for multi-modality image registration, the similarity measure for intensity components can be local mutual information, squared local cross correlation, and the like. With reference to the flow chart of FIG. 2 a , the fixed image ( FIG. 2 b ) and moving image ( FIG. 2 c ) are brought into rough alignment at steps 200 a and 200 b . At step 202 a , feature points are detected on the fixed image. These are designated as exemplary points 1 , 2 and 3 in FIG. 2 b . In step 202 b , feature points are similarly detected on the moving image. These are likewise indicated as points 1 , 2 and 3 in FIG. 2 c . In step 204 a , a feature vector is assigned to each point for the fixed image shown in FIG. 2 b . In step 204 b , a feature vector is assigned to each point for the moving image depicted in FIG. 2 c . In step 206 , the dissimilarity of each pair of feature vectors for feature pairs on the fixed and moving images is calculated. Given a set of correspondences {Xi} on the fixed image ( FIG. 2 b ) and {Xi} on the moving image, where i=1, . . . , n, the deformation is modeled using a Cubic B-spline Free Form Deformation (FFD) model. The FFD is a space deformation model, which essentially deforms an object by manipulating a regular control lattice P that is overlaid on the volumetric embedding space. This is described in more detail below. In step 208 , the correspondence between feature pairs {Xi} and {Xi′} is calculated. In step 210 , a closed form solution to solve for the dense deformation field represented by P is solved utilizing FFD model. In step 212 , the moving image ( FIG. 2 c ) is transformed using the current FFD deformation field estimate. If the deformation update is not small enough, at step 214 the procedure is looped back to step 206 through a predefined number of iterations until the deformation update is sufficient.
[0023] In order to utilize similarity measures for finding local correspondences, suppose a local window centered at a feature point is W, the fixed image is f, and the moving image is m. The first multi-modal similarity measure is the Squared Normalized Cross Correlation:
R = ( ∑ ( i , j ) ∈ w ( f ( i , j ) - ( f _ ) ) ( m ( i , j ) - ( m _ ) ) ∑ ( i , j ) ∈ w ( f ( i , j ) - ( f _ ) ) 2 ∑ ( i , j ) ∈ w ( m ( i , j ) - ( m _ ) ) 2 ) 2
where f denotes the mean intensity value in the local window on the fixed image, and m is the mean intensity value in a local window on the moving image. Another similarity measure is the Local Mutual Information, where we denote the intensity probability distribution in the small window in the fixed image or volume as p f , and that in the testing window in the moving image or volume as P m . With the joint density as P f,m , the local mutual information is defined as
MI = H ( f ) + H ( m ) - H ( f , m ) = ∫ ∫ P f , m ( i 1 , i 2 ) log P f , m ( i 1 , i 2 ) P f ( i 1 ) P m ( i 2 ) ⅆ i 1 ⅆ i 2
[0024] As described briefly above, given a set of corresponding points between the fixed image and the moving image, we model the deformation using a Cubic B-spline FFD model, which is a space deformation model that deforms an object by manipulating a regular control lattice P overlaid on the volumetric embedding space. In the registration problem, the inverse inference problem is considered, in which the deformations between images are solved with respect to the control lattice coordinates that are parameters of FFD. The following describes the closed-form FFD based registration method in detail.
[0025] Considering a regular lattice of control points:
P m,n =( P m,n x P m,n y ); m= 1, . . . , M, n=1 , . . . , N
overlaid to an image region
Γ={ x }={( x,y )|1≦ x≦X, 1 ≦y≦Y}
Denote the initial configuration of the control lattice as P 0 , and the deforming control lattice as P=P 0 +δP. Under these assumptions, we consider the FFD parameters are the deformations of the control points in both directions (x,y);
Θ={(δ P m,n x ,δP m,n y )};( m,n )∈[1 ,M]×[ 1 ,N]
Given the deformation of the control lattice from P 0 to P, the deformed location L(x)=(x′,y′) of a pixel x=(x,y), is defined in terms of a tensor product of a Cubic B-spline:
L ( x ) = x + δ L ( x ) = ∑ k = 0 3 ∑ l = 0 3 B k ( u ) B l ( v ) ( P i + k , j + l 0 + δ P i + k , j + l )
where, by definition:
x = ∑ k = 0 3 ∑ l = 0 3 B k ( u ) B l ( v ) P i + k , j + l 0
are the initial coordinates of the pixel x.
δ L ( x ) = ∑ k = 0 3 ∑ l = 0 3 B k ( u ) B l ( v ) δ P i + k , j + l
is the incremental deformation at pixel x,
δP i+k,j+l , (k,l)∈[0,3]×[0,3], in which
i = ⌊ x X · ( M - 1 ) ⌋ + 1
and
j = ⌊ y Y · ( N - 1 ) ⌋ + 1 ,
consists of the deformations of pixel x's (sixteen) adjacent control points,
B k (u) is the k th basis function of the Cubic B-spline given by;
B 0 ( u )=(1 −u ) 3 /6 , B 1 ( u )=(3 u 3 −6 u 2 +4)/6
B 2 ( u )=(−3 u 3 +3 u 2 +3 u+ 1)/6, B 3 ( u )= u 3 /6
with
u = x X · M - x X _ · M π _ · B l ( v )
is similarly defined.
From the equation above, we have:
L ( x ) - x = ∑ k = 0 3 ∑ l = 0 3 B k ( u ) B l ( v ) δ P i + k , j + l
In accordance with the inventive method for efficient non-rigid image registration, we pick n feature sample points x i =(x i , y i ), i=1, . . . ,n, from the target (fixed) image ( FIG. 2 b ), and find their correspondences x i ′=(x i ′, y i ′), on the source (moving) image ( FIG. 2 c ). In a typical 256*256 image, n can range from several hundred to several thousand, and can be chosen depending on the estimated intrinsic resolution of the image deformation to be recovered Assuming x i ′ is the deformed location L(x), then the relationship between the two point sets can be depicted in a matrix equation format as follows:
U=Sp
where, U is the displacement matrix between the correspondence pairs:
U = ( x 1 ′ - x 1 y 1 ′ - y 1 x 2 ′ - x 2 y 2 ′ - y 2 ⋮ ⋮ x n ′ - x n y n ′ - y n ) n × 2 ,
S is the Cubic B-spline basis matrix:
S = ( … … [ b i 1 + 0 , j 1 + l ] … [ b i 1 + 1 , j 1 + l ] … [ b i 1 + 2 , j 1 + l ] … [ b i 1 + 3 , j 1 + l ] … ⋰ ⋰ ⋰ ⋰ ⋰ … [ b i c + 0 , j c + l ] … [ b i c + 1 , j c + l ] … [ b i c + 2 , j c + l ] [ b i c + 3 , j c + l ] … … ⋰ ⋰ ⋰ ⋰ ⋰ … … [ b i n + 0 , j n + l ] … [ b i n + 1 , j n + l ] … [ b i n + 2 , j n + l ] … [ b i n + 3 , j n + l ] … ) ,
And p is comprised of the FFD parameters in a matrix:
( δ P 1 , 1 x δ P 1 , 1 y δ P 1 , 2 x δ P 1 , 2 y ⋮ ⋮ [ δ P i c + 0 , j c + l x ] [ δ P i c + 0 , j c + l y ] ⋮ ⋮ [ δ P i c + 1 , j c + l x ] [ δ P i c + 1 , j c + l y ] ⋮ ⋮ [ δ P i c + 2 , j c + l x ] [ δ P i c + 2 , j c + l y ] ⋮ ⋮ [ δ P i c + 3 , j c + l x ] [ δ P i c + 3 , j c + l y ] ⋮ ⋮ δ P M , N x δ P M , N y ) ( M × N ) × 2.
In the B-Spline basis matrix S, c=1, . . . , n is the index of a corresponding pair, and [b i c +k,j c +l ] is the abbreviation for:
[ b i c +k,j c +l ]=B k ( u c ) B 0 ( v c ) B k ( u c ) B 2 ( v c ) B k ( u c ) B k ( v c ) B k ( u c ) B 3 ( v c ) .
In the FFD parameter p matrix, [δP i c +k,j c +l ] is the abbreviation for:
[ δ P i c + k , j c + l ] = ( δ P i c + k , j c + 0 δ P i c + k , j c + 1 δ P i c + k , j c + 2 δ P i c + k , j c + 3 ) ,
and the column indices of a [b i c +k,j c +l ] in S are the same as the row indices as a [δP i c +k,j c +l ] in matrix p. Thus, based on this parametric free form transformation model, a closed form solution for the control lattice deformation can be solved utilizing Singular value Decomposition efficiently as:
p • = S + U
In real applications, since the process of finding the correspondences introduces errors, the solution to the foregoing is the Ordinary Least Squares (OLS) solution to the problem:
p minimize ∑ i = 1 n x i ′ - L ( p ; x ) .
This approach efficiently recovers relatively large to local non-rigid deformations utilizing sparse feature correspondences in closed form. The resulting deformation field has been demonstrated to be globally smooth, and minimizes the distance between the target feature points and transformed source feature points. FIG. 3 is a comparison of the recovered space deformation and ground truth deformation for the exemplary images depicted in FIGS. 2 b and 2 c . In this example, the moving image is a phantom image generated by artificially deforming the regular control lattice. Accordingly, the ground-truth deformed control lattice that originally generated the moving image is known. By comparing the deformation field recovered by the registration method disclosed herein with the ground truth deformation, the accuracy of the registration method is known.
[0026] The present invention has been shown and described in what are considered to be the most practical and preferred embodiments. It is anticipated, however, that departures may be made therefrom and that obvious modifications will be implemented by those skilled in the art. It will be appreciated that those skilled in the art will be able to devise numerous arrangements and variations which, although not explicitly shown or described herein, embody the principles of the invention and are within their spirit and scope. | A method and system for non-rigidly registering a fixed to a moving image utilizing a B-Spline based free form deformation (FFD) model is disclosed. The methodology utilizes sparse feature correspondences to estimate an elastic deformation field in a closed form. In a multi-resolution manner, the method is able to recover small to large non-rigid deformations. The resulting deformation field is globally smooth and guarantees one-to-one mapping between the images being registered. The method generally comprises the steps of: detecting feature points on the fixed image and feature points on the moving image; assigning a feature vector to each feature point; calculating the dissimilarity of each pair of feature vectors for feature pairs on the fixed image and the moving image; calculating the correspondence between feature pairs based on the dissimilarity measure; solving for a dense deformation field P using a closed form FFD model; and transforming the moving image and the feature points on the moving image using a current FFD deformation field estimate. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to methods of manufacturing reduced-warp nitride substrates for semiconductors, and to nitride semiconductor substrates manufactured by the method.
[0003] Substrates on which semiconductor devices are fabricated are round wafers, and given that the devices are fabricated on the front surface of the substrates by such methods as photolithography, doping, diffusion, and vapor deposition including chemical vapor deposition (CVD), the front surface must be flat, with minimal warp. When fabricating semiconductor devices onto silicon and onto gallium arsenide in particular as substrates, Si and GaAs wafers with minimal warp, polished to an optically smooth, mirror finish are employed.
[0004] Sapphire wafers are used as the substrates for blue light emitting diodes in which indium gallium nitride is the light-emitting layer. InGaN/GaN-based LEDs formed onto sapphire substrates have performed well and are dependable. The sufficiently moderate cost of sapphire substrates has meant that InGaN-based LEDs can be made at low-cost.
[0005] Nevertheless, there are drawbacks to sapphire. For one, with sapphire being an insulator, rather than attaching n electrodes to the bottom, a GaN layer onto the surface of which the n electrodes are attached is applied, thus requiring excess area. Another is that since sapphire does not cleave, it cannot be rent into chips along natural cleavages. And because it is GaN and InGaN that are grown onto the heterosubstrate there is misfit, which leads to heavy defects.
[0006] Under the circumstances, then, it is desirable that GaN itself be the substrate. GaN substrates have become producible by depositing a thick GaN film onto a heterosubstrate base using vapor-phase deposition and removing the base to create a GaN freestanding layer. And in terms of size, 50-mm diameter substrates—long-awaited—have also become possible.
[0007] Vapor-phase grown GaN-crystal wafers are, however, used as-grown for epitaxial deposition substrates. In the front side of GaN substrates that have been vapor-phase deposited and nothing more roughness is considerable and warp is serious; growing GaN and InGaN onto such substrates will not necessarily lead to a lowering of defects over the situation with sapphire substrates. And LEDs created experimentally on as-grown GaN substrates certainly do not perform better than LEDs manufactured on sapphire.
[0008] Because the formation of semiconductor devices onto GaN substrates is by photolithography, flat, mirror-finish wafers with minimal warp are desired as the substrates. Polishing and etching technology is necessary to render the surface of a wafer optically smooth. Polishing and etching technologies have already been established for fully developed semiconductor substrates such as Si and GaAs. Si and GaAs crystal can be grown by gradually solidifying a melt, as in the Czochralski method or the Bridgeman method. Since long, columnar ingots with few dislocations can be produced by growing from the liquid phase, the ingots are sliced with an internal-diameter saw to produce wafers. This means that warp is minimal from the start.
[0009] With GaN on the other hand, growth, being impossible from the liquid phase, is by means of vapor-phase deposition. Furthermore, what form optimal polishing and etching methods should take is still not understood. If GaN is to be hetero-deposited onto crystal of a different kind, such as has three-fold symmetry, the growth will necessarily be c-axis oriented. The surfaces are a (0001) plane and a (000{overscore ( 1 )}) plane. Because GaN crystal does not have reverse symmetry, the (0001) and (000{overscore (1)}) planes are not crystallographically equivalent. The (0001) face is one in which gallium atoms range in lines globally over the episurface and the (000{overscore (1)}) face is one in which nitrogen atoms range in lines globally over the episurface.
[0010] The former can be referred to as the (0001) Ga face, or simply the Ga face; the latter, as the (000{overscore (1)}) N face, or simply the N face. Physiochemically the Ga face is extremely unyielding and rugged, and is not dissolved by chemical agents. The N face is also physiochemically robust, but is corroded by certain types of strong acids and alkalis. GaN crystal has such asymmetry.
[0011] When GaN is grown onto a base substrate, the front side and back side become either the Ga face or the N face. Depending on how the base substrate is selected, the front side can be made the Ga face or the N face. The back side then becomes the face with the opposite polarity.
[0012] For the sake of simplicity, a case in which the front side is the (0001) Ga face, and the back side is the (000{overscore (1)}) N face will be considered. The same statements can be made, and the same design features implemented in the opposite situation as well.
[0013] Since the subject of the present invention is warp, to begin with a definition of warp will be given. Warp can be expressed as radius of curvature, or curvature. These are exact expressions and can be given locally. Even in situations in which the warp is complex and the substrate has heavy roughness, exact warp can be expressed using a local curvature expression. For example, warp with a saddle point and cylindrical-lens-like warp can also be expressed.
[0014] But with uniform buckling in round wafers, warp is often represented by a simpler expression. If the roughness is uniform the wafer is measured taking the height H to the planar face from the surface of the center area in the convexity, according to which a value for the warp is given. This is intuitive, and facilitates measurement. The absolute value is determined by this warp measurement.
[0015] The sign of the warp will be given by its orientation. This definition is indicated in FIG. 1 . Warp curving outward along the front side will be termed positive (H>0); warp curving inward along the front side will be termed negative (H<0).
[0016] In situations in which long monocrystal ingots with few dislocations can be produced—such as is the case with Si and GaAs—since the ingots are sliced with an internal-diameter saw or a wire saw, warp is slight from the start. To produce GaN crystal, however, with growth from the liquid phase being impossible, vapor-phase growth is carried out. Because rendering GaN crystal is by heteroepitaxy onto a heterosubstrate that differs from GaN in thermal expansion coefficient, and then removal of the heterosubstrate, considerable warp appears in GaN crystal. This problem is due not only to the difference in thermal expansion coefficient, but also to the many dislocations that come about because the base substrate and the overlying film are different materials. The dislocations give rise to irregular stresses, which due to the volume of dislocations is why warp comes about.
[0017] As-grown, platelike, 20-50 mm diameter GaN crystal from which the base substrate has been removed has a warp of from ±40 μm to as much as ±100 μm, although the value will differ depending on the type and crystal-plane orientation of the base substrate, and on the vapor-phase deposition parameters.
[0018] With the warp in a GaN wafer substrate being that extensive, in a situation in which a photolithographic resist on the wafer is to be exposed its dimensions will be thrown out of balance. Thus the warp must be extensively reduced. Warp in Si and GaAs wafers also has to be lessened, but with GaN there is a special reason why warp has to be reduced. Since GaN is transparent, when the wafer is set on a susceptor with a built-in heater and heated, not much of radiant heat from the heater heating the GaN crystal occurs. Seeing as how thermal conduction from the susceptor is the principal heat-transmission means, the back side of the GaN crystal desirably is flat, with its entire surface in contact with the susceptor without gaps.
[0019] Instances of the above outward-curving (positive warp, H>0) mean that the wafer center portion comes apart from the susceptor. Such cases are still the better, because the thermal conduction is from the peripheral margin heading toward the center. Oppositely, in instances of the above inward-curving (negative warp, H<0), with only the center contacting susceptor the wafer ends up turning, leading to positional instability. Not only that, but source-material gases circle to the back side through the encompassing, lifted-up area, causing thin-film growth or etching to occur on the backside of the substrate also. Consequently, negative warp is even less suited to semiconductor fabrication needs than positive warp.
[0020] Because as-grown GaN crystal has a warp H of from ±40 μm to ±100 μm, the number one objective is to decrease the warp to be within a +30 μm to −20 μm range.
[0021] More advantageously, the warp should be decreased to within a +20 μm to −10 μm range.
[0022] Furthermore, if possible, bringing the warp to within +10 μm to −5 μm would even better meet fabrication needs.
[0023] There are any number of examples of devising a crystal growth method to minimize warp in the products. These may be grossly bifurcated into those that reduce warp by lateral overgrowth of the GaN to alleviate vertically oriented stress and reduce internal stress, and those that grow two layers having competing actions and eliminate warp by the balance between the actions. Every one of these is a way of attempting to reduce, via the deposition parameters, warp in crystal being grown; they are not ways of attempting to reduce warp in crystal already produced.
[0024] 2. Description of the Background Art
[0025] Japanese Unexamined Pat. App. Pub. No. H11-186178 addresses the problem of incidents of warp and cracking in GaN crystal that due to the difference in the coefficients of thermal expansion of Si and GaN occur when a GaN film is grown onto an Si substrate to create a GaN/Si composite substrate.
[0026] This reference relates that to prevent warp and cracking from occurring in GaN crystal, stripes of SiO 2 film are formed onto an Si substrate, and when GaN film is grown onto the substrate, atop the SiO 2 growth of GaN does not initially occur, thereby alleviating stress and reducing warp in the GaN/Si composite substrate. This substrate is not an independent film of GaN, but rather a composite substrate in which a thin GaN layer on the order of 10 μm is provided on an Si base, so that internal stress in the GaN layer can be reduced by having the SiO 2 intervene.
[0027] Japanese Unexamined Pat. App. Pub. No. 2002-208757 concerns manufacturing nitride semiconductor substrates of satisfactory crystallinity, by employing lateral overgrowth and, to keep warp under control, dispersing throughout the substrate overall the coalescence boundaries, where defects concentrate.
[0028] Japanese Unexamined Pat. App. Pub. No. 2002-335049 proposes a deposition method that by reducing dislocations by means of lateral overgrowth to diminish stress, also reduces warp.
[0029] Japanese Unexamined Pat. App. Pub. No. 2002-270528 proposes a deposition method in which reducing dislocations by means of lateral overgrowth to reduce stress keeps warp from occurring.
[0030] Japanese Unexamined Pat. App. Pub. No. 2002-228798 exploits Si crystal not as a semiconductor but as a mirror. The goal is to create concave or convex mirror surfaces from Si crystal. To get Si crystal to possess a desired curvature, it must be deformed. To do so, a thin film of diamond is built up on an Si substrate, and the Si substrate is deformed by the stress between the diamond thin film/Si substrate. In other words, the original planar article is forcibly buckled to lend it a concave or convex mirror surface. The reference states that Si can be buckled into a curvature of choice depending on the diamond formation parameters.
[0031] Japanese Unexamined Pat. App. Pub. No. 2003-179022 addresses the problem that after forming semiconductor devices onto a large-caliber Si wafer, the wafer is back-side ground and the back side is mechanically planed to reduce the wafer to a desired thickness, but a processing distortion layer is formed, producing a warp of 800 μm, and etching away the layer takes too much time. This reference states that, given the realization that the processing distortion layer on the Si wafer back side is amorphous, warp is eliminated by exposing the Si back side for 5 seconds with light from a halogen lamp to momentarily heat the wafer to 600-700° C. and convert the processing distortion layer from an amorphous to a crystalline state. Thus this is an example not of ridding the wafer of the processing distortion layer, but eliminating warp in the wafer by qualitatively transforming the layer.
[0032] Inasmuch as nitride semiconductor is chiefly produced using vapor-phase deposition to build up a thin film onto a heterosubstrate and removing the base substrate, with dislocations due to the difference in thermal expansion coefficients and the mismatching lattice constants occurring at a high density, warp is serious. Although methodologies for diminishing warp by devising growth methods to diminish internal stress have been variously proposed, they are yet insufficient.
[0033] Even with such methodologies, manufacturing nitride semiconductor crystal of large film thickness and large diameter means the dislocations and warp will be considerable, and when the base substrate is removed the crystal often ends up cracking. Even if the crystal does not crack, the warp will be large, reaching ±40 μm to as much as ±100 μm.
SUMMARY OF THE INVENTION
[0034] Objects of the present invention are in such crystal substrates in which warp is large to reduce the warp by means of a post-deposition process.
[0035] A first object is bringing out a processing method so that the warp figure for nitride semiconductor substrate as 2-inch wafers is brought to within a range of +30 μm to −20 μm. A second object is bringing out a processing method that brings the warp figure for GaN substrates to within +20 μm to −10 μm. A third object of the present invention is making available a processing method in which, the warp figure for nitride semiconductor substrates is reduced to within +10 μm to −5 μm by means of a post-deposition process. A fourth object of the present invention is bringing out nitride semiconductor substrates in which the warp is within +30 μm to −20 μm.
[0036] A method of manufacturing nitride semiconductor substrates according to one aspect of the present invention addresses warp in a nitride semiconductor substrate by mechanically grinding, to introduce a damaged layer into, the concave face of the buckled substrate, thereby extending the concave face, bringing it close to being planar and reducing the warp.
[0037] In accordance with a nitride substrate manufacturing method in another aspect of the invention, by mechanically grinding, to introduce a damaged layer into, the concave face of a nitride semiconductor substrate in which there is warp, the concave face is extended to deform it convexly; and by etching the convexly deformed surface to remove the damaged layer partially or entirely and bring down the convex face, the substrate is brought close to being planar, which reduces the substrate warp.
[0038] According to a manufacturing method in a further aspect of the invention, by mechanically grinding, to introduce a damaged layer into, the concave face of a nitride semiconductor substrate in which there is warp, the concave face is extended to deform it convexly; the convexly deformed surface is etched to remove the damaged layer partially or entirely and bring down the convex face; and by mechanically grinding, to introduce a damaged layer into, the surface that has turned into a concave face on the opposite side, the concave face is extended, rendering it a convex face; by etching the surface that has now been convexly deformed and bringing down that convex face, the substrate is brought close to being planar, which reduces the substrate warp.
[0039] A further aspect of the invention is a manufacturing method according to which, by mechanically grinding, to introduce a damaged layer into, the concave face of a nitride semiconductor substrate in which there is warp, the concave face is extended to deform it convexly; and by mechanically grinding, to introduce a damaged layer into, the surface that has turned into a concave face on the opposite side, the concave face is extended, rendering it a convex face; by etching the surface that has now been convexly deformed and bringing down that convex face, the substrate is brought close to being planar, which reduces the substrate warp.
[0040] From the following detailed description in conjunction with the accompanying drawings, the foregoing and other objects, features, aspects and advantages of the present invention will become readily apparent to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] FIG. 1 is exaggerated, outline sectional views of a substrate, representing definitions of the sign given to warp, in which convex warp along the front side is positive, and convex warp along the backside is negative.
[0042] FIG. 2 is a graph plotting measurements of front-side roughness (Ra: μm) and damaged layer depth for when the front side of a 2-inch GaN wafer underwent a grinding operation with #80, #325, and #1000 diamond grit. The horizontal axis is the grit (mesh) number, the right vertical axis is the level of surface roughness Ra (μm), and the left vertical axis is damaged layer depth (μm). It is apparent from the graph that with the grit as the mediating agent, the deeper the damaged layer is, the larger the surface-roughness level becomes.
[0043] FIG. 3 is a graph plotting measured values of warp H against those of etching depth when a damaged layer on the back side (N face) of a post-back-side-ground GaN wafer was wet-etched utilizing a KOH solvent. The horizontal axis is the etching depth (μm), and the vertical axis is the wafer warp H(μm). From the graph it is evident that etching a wafer with an initial −33 μm concave warp (curving inward along the front side) proceeded to decrease the warp. When some 5 μm had been etched, the warp became a constant −10 μm or so, not decreasing to less than that.
[0044] FIG. 4 is a graph plotting measured values of warp H against those of etching depth when a damaged layer on the front side (Ga face) of a GaN wafer after having been ground utilizing a chlorine plasma was dry-etched. The horizontal axis is the front-side etching depth (μm), and the vertical axis is the wafer warp H(μm). From the graph it is evident that etching a wafer with an initial +41 μm convex warp (curving outward along the front side) proceeded to decrease the warp. When some 6 μm had been etched, the warp became a constant +10 μm or so, not decreasing to less than that.
[0045] FIG. 5 is crystal-section views for explaining fundamental techniques of the present invention for reducing warp in wafers by combining formation of a damaged layer by grinding, and reduction of the damaged layer by etching. The upright lines represent dislocations, and the speckles represent damaged layers. FIG. 5A illustrates a technique for a situation in which a post-growth substrate crystal is convexly buckled along the front side (H>0), in which grinding the back side creates a damaged layer on the back side, extending the back side and reducing the warp. FIG. 5B illustrates a technique for a situation in which a post-growth substrate crystal is concavely buckled along the front side (H<0), in which grinding the front side introduces a damaged layer on the front side, extending the front side and reducing the warp. FIG. 5C illustrates a technique for a situation in which grinding the back side has produced a damaged layer to excess, resulting in concave warp along the front side, in which the damaged layer on the back side is removed by etching, which thins down the damaged layer to reduce the warp.
DETAILED DESCRIPTION OF THE INVENTION
[0046] From stages in manufacturing a GaN substrate to grinding and etching in the present invention will be explained in more detail.
[0047] 1. Growing GaN Ingots—GaN freestanding layers are created according to the method set forth in Japanese Unexamined Pat. App. Pub. Nos. 2000-12900 and 2000-22212. An epitaxial lateral overgrowth (ELO) mask is laid onto a (111) GaAs wafer, and the GaN is grown by a vapor-phase epitaxy technique such as hydride or metalorganic-chloride vapor phase epitaxy (HVPE or MO-chloride VPE).
[0048] The GaN is grown on the ELO mask to reduce stress in the crystal, and moreover is subjected to facet growth to reduce dislocations. The deposition yields GaN of 100 μm to several mm in thickness, and the GaAs substrate is removed to give an independent GaN substrate.
[0049] Techniques for removing the GaAs base substrate include dissolving with aqua regia, shaving off by polishing, and delaminating by a lift-off process. GaN films grown thin render single, freestanding GaN wafers; when thick they are cut with a wafer saw to yield a plurality of wafers.
[0050] As-grown GaN crystal after the GaAs has been removed is often convex along the back side, and the warp amplitude His often ±40 μm to as much as ±100 μm. The roughness (R max ) along the back side can be 10 μm or more. Such serious warp occurs owing to the large difference in thermal expansion coefficient between the base substrate and the GaN, and to the massive dislocations produced by their mismatching lattices. Occurrences of such warp are inevitable despite a mask-utilizing lateral overgrowth technique as just discussed being carried out.
[0051] To have the GaN substrates be as they should for manufacturing semiconductor devices onto them, the warp must be decreased, and the front and back sides planarized (lowering the degree of surface roughness). Henceforth a discussion of the present invention will develop.
[0052] 2. Evaluating Damaged layer in Ground Substrates—The post-grinding damaged layer on the substrates was evaluated by cross-sectional observation using scanning electron microscopy (SEM) and cathode luminescence (CL).
[0053] From the observation results, it was evident that on a substrate in which the GaN crystal face was ground employing #325 diamond grit, the depth of the damaged layer was approximately 4.8 μm.
[0054] The mesh (size) of the diamond grit correlates with the surface roughness. The rougher the grit is the rougher the surface ground with the grit will be. With finer grit texture, the face ground with the grit will turn out planar. In turn, since the damaged layer arises from grinding, the damaged layer ought to bear a relationship to the roughness of the grit. This means that by way of the roughness of the grit texture, there ought to be a correlation between the thickness of the damaged layer and the surface roughness.
[0055] Given these considerations, the relation between the depth of the damaged layer and the surface roughness was investigated. The results are shown in the FIG. 2 graph. The horizontal axis is the mesh (#). The larger the number, the finer the grit is. Plotted in the graph are damaged layers on GaN crystal planed with #80, #325 and #1000 grit, versus roughness. The vertical axis on the left indicates damaged layer depth (thickness in μm), while the vertical axis on the right indicates surface roughness Ra (μm).
[0056] From the graph it will be understood that the lower the surface roughness, the thinner will be the damaged layer. The depth of the damaged layer is dependent on the grain size of the diamond grit employed. The significance of this is that the depth of the damaged layer can be controlled. Using a fine-textured grit diminishes the damaged layer and makes it smooth. By the same token, using a coarse-textured grit allows a thick damaged layer to be created deliberately.
[0057] Grinding with a grit of a suitable texture smoothes, and produces a damaged layer on, the GaN substrate face. The damaged layer acts to stretch the surface on which it is formed. If the action is excessive, the crystal will end up buckling oppositely. In order to rectify this, the damaged layer should be partially removed, and to do so etching was carried out. For the etch, both wet etching using chemical agents and dry etching using plasma were tried.
[0058] 3. Study of Front-Side Wet Etching—After being processed, the surface of a GaN substrate underwent wet etching. KOH (aqueous solution, 8 N concentration) was heated to 80° C., and the GaN substrate was wet-etched by immersing it into the solution. The warp was not, however, altered. This means that a GaN crystal face on which a damaged layer has been produced by polishing is not wet-etched by KOH.
[0059] The (0001) faces of GaN have polarity. One face (the Ga face) is terminated with gallium atoms, and the other face (the Ga face) is terminated with nitrogen atoms. The Ga face is hard and unyielding, and is chemically stable. No chemical agent that can effectively etch a Ga face exists. Since the front side was the Ga face and the back side the N face, when the substrate was dipped into the KOH solution the back-side N face was slightly etched but the front-side Ga face was not etched at all. Because the front side, being polished, had the damaged layer, KOH did not remove the front-side damaged layer.
[0060] Wet-etching GaN with a strong alkali like heated KOH, or a strong acid such as H 3 PO 4 has been documented. But such instances have amounted only to erosion of the N face. The GaN that the present invention inventors manufacture possesses a composite front side in which the N face and the Ga face appear in alternation. Since wet-etching the GaN in an etchant such as KOH or H 3 PO 4 etches only the N face, creating pits, the front side ends up being ragged. Despite the pains taken to polish the front side, it ends up ruined, not amounting to anything. Ultimately, therefore, wet-etching of the front side (Ga face) proves to be impossible.
[0061] 4. Back-Side Wet Etching—The back side (N face) of GaN substrates is ground. A damaged layer is created on the back side by polishing, and the substrates buckle convexly along the back side (warp: negative). It was discovered that when substrates having a negative warp are wet-etched with an 8 N KOH solution at 80° C. or with H 3 PO 4 phosphoric acid, with elapsed etch time the absolute value of the warp decreases. That is, the back side—being the N face—is etched by a strong alkali and a strong acid, and by the very diminishment of the diminishing damaged layer, the warp is curtailed. This means that back-side polishing and wet etching form a method that can be utilized to curtail warp.
[0062] Results of thus utilizing the method are shown in FIG. 3 . Under conditions for back-side wet etching identical to those just noted, the back side of a GaN substrate was wet-etched. The horizontal axis in the graph represents the wet-etching depth (μm), and the vertical axis, warp (μm). From the graph it is evident that wet-etching a concave GaN substrate whose front side possessed an initial −33 μm concave warp curtailed the warp. When some 5 μm had been etched, the warp went to around −10 μm; etching beyond that did not lead to diminishment of the −10 μm warp.
[0063] In addition, variation in the thickness was under several μm, which was at the non-problematic level.
[0064] Wet-etching the back side of the substrate gave the GaN crystal—whose front side, being globally mirror-finished, was transparent—a clouded appearance like frosted glass. This was because the back side had been surface-roughened. Since the warp was reduced, in situations in which it is acceptable for the back side to be glazy, the substrate can be used in that state.
[0065] There are situations, however, in which the back side being glazy would create problems—in which the back side has to be a mirrorlike surface. In such cases, arrangements have to be made to remove the damaged layer by dry-etching the back side. When removal is by dry etching, the back side does not become frosted-glasslike.
[0066] The fact that wet-etching the Ga face is impossible, while wet-etching the N face is possible has been noted. The N face (back side) can be rid of a damaged layer by either wet etching or dry etching. For the front side, removal is only by means of dry etching.
[0067] 5. Study of Front-Side Dry Etching—Inasmuch as wet etching is ineffectual, the only option for etching the front side (Ga face) is by dry etching. Provided that dry etching is feasible, by that means removing a damaged layer along the front side of a GaN substrate ought to be possible.
[0068] Performing dry etching of GaN under the following conditions makes it possible to etch the front side.
Equipment: reactive ion etcher Gas: halogen gas (chlorine gas) Chlorine flow rate: 5 sccm to 100 sccm Pressure during etch: 0.1 Pa to 10 Pa Plasma power: antenna - 100 W to 500 W bias - 5 W to 20 W
[0069] Plotted in FIG. 4 is the relationship between front-side etching depth and warp when the front side (Ga face) of a GaN substrate was dry-etched at: chlorine flow rate=10 sccm; pressure=1 Pa; antenna power 300 W; bias 10 W. The horizontal axis is the etching depth (μm); the vertical axis is the warp (μm). Although the warp was initially 40 μm, the etching carried out proceeded to curtail the warp: When the etching depth was 0.8 μm, the warp had decreased to +30 μm; at 1.3 μm etching depth the warp had decreased to +22 μm; at 2 μm etching depth, the warp had subsided to +16 μm; at 3.6 μm etching depth, the warp had subsided to +13 μm; at 5.5 μm etching depth, the warp had curtailed to +10 μm; and when the etching depth had gone to over 6 μm, the warp no longer subsided, staying at the +10 μm level.
[0070] It was realized that although with the front side being the Ga face, the front side could not be etched by wet etching techniques, with a dry etching technique—reactive ion etching (RIE)—the Ga face too could be etched. Then it was also realized that by means of the etching, positive warp (convexity in the front side) decreases. This was a crucial discovery. With the damaged layer being on the front side, the layer brought about positive warp (convexity along the front side). Since what gave rise to the positive warp was curtailed because the front side was reduced, the warp proceeded to decrease. Such is the plausible interpretation.
[0071] 6. Study of Back-Side Dry Etching—Under the same conditions as with the front side, dry etching was possible on the back side (N face) of a GaN substrate. By means of dry etching using chlorine plasma, removal of a damaged layer from the back side was also possible. Removing the damaged layer from the back side altered the warp from being concave with respect to the front side to being convex with respect to the front side. (The warp changed heading from negative-ward to positive-ward.) And removing the damaged layer on the substrate back side was possible without spoiling the surface smoothness of the back side.
[0072] 7. Controlling Warp—Herein it will become clear that warp can be controlled by combining grinding or a like mechanical process, and dry etching. A damaged layer forms when either the front side (Ga face) or the back side (N face) is ground. The damaged layer produces compressive force on the ground face, tending to stretch it. The front side therefore deflects convexly when a damaged layer is made on the front side. And the back side deflects convexly when a damaged layer is made on both sides. The warp rate can be modulated by the thickness d of the damaged layer, and the damaged layer can be removed by dry etching. If thus the thickness of the damaged layer is decreased, the warp will change from being convex to being concave. These are the reasons why warp can be controlled by the formation of a damaged layer.
[0073] Such instances are illustrated in FIG. 5 . The plural vertical lines drawn within the wafers represent dislocations. Further, fine stipples are drawn by the front/back side of the wafers; these are the damaged layer produced by grinding. FIG. 5A illustrates a technique for a wafer whose front side is convex (H>0), in which grinding the concave back side creates a damaged layer on the back side to curtail the warp. FIG. 5B illustrates a technique for a wafer whose front side is concave (H<0), in which grinding the concave front side forms a damaged layer on the front side to curtail the warp. FIG. 5C illustrates a technique of back-side dry-etching in which the back side of a wafer whose front side is concave (H<0) is ground to create on the back side a damaged layer, and the damaged layer on the back side is reduced and thinned down.
[0074] The warp in a GaN substrate deposited by a vapor-phase deposition onto a heterosubstrate, from which the base substrate is removed, is ±40 to as much as ±100 μm. If thus the warp is large, the error in the optical exposure pattern during device fabrication by photolithography will be too great. When contact exposing a substrate it is pressed upon, and if there is warp, the substrate can crack. Therefore, warp in the GaN substrate has to be +30 μm to −20 μm. More desirably, the warp is +20 μm to −10 μm, and optimally it is +10 μm to −5 μm.
[0075] GaN substrates are transparent. Forming thin films onto the GaN wafers by metalorganic chemical vapor deposition (MOCVD) or molecular-beam epitaxy (MBE), or vapor-depositing electrodes on the wafers means that they are placed on a susceptor with a built-in heater and heated; but because the wafers are transparent, they do not sufficiently absorb the radiant heat from the heater. Rather than the radiant heat, a wafer absorbs heat from the susceptor due to thermal conduction. Because the absorption route is by thermal conduction, it is vulnerable to how the wafer and susceptor are in contact. To make the heating uniform, the state of contact between the wafer and susceptor must be made uniform. If there is warp in the wafer, thermal conduction will be restricted to the central portion (concave warp) or to the peripheral portion (convex warp). With uniform heating being impossible on account of such warp, a strong, diametrically oriented temperature distribution is set up in the wafer. Consequently, the characteristics of the fabricated devices end up being inconsistent. In this respect GaN substrates differ vastly from Si and GaAs substrates.
[0076] Thus, as far as warp is concerned, more severe conditions are imposed on GaN substrates than on Si or GaAs substrates. Since in order to make thermal conduction uniform, globally even contact with the susceptor is sought, zero warp is ideal. The spread in which warp is tolerated is not identical above and below zero: a tolerance range in which above, where warp is convex, is up to 30 μm, and below, where warp is concave, is as far as 20 μm.
[0077] Thus the ranges of warp that can be tolerated are
Equipment: reactive ion etcher Gas: halogen gas (chlorine gas) Chlorine flow rate: 5 sccm to 100 sccm Pressure during etch: 0.1 Pa to 10 Pa Plasma power: antenna - 100 W to 500 W bias - 5 W to 20 W
[0078] Advantageous Features of the Invention—If with warp being large semiconductor devices are fabricated by photolithography onto GaN crystal wafer obtained by using vapor-phase deposition to grow GaN onto a heterosubstrate and stripping off the heterosubstrate, error in the transfer pattern will be significant. And there will be instances of cracking in the wafer when it is vacuum-chucked.
[0079] Inasmuch as the present invention brings the wafer warp to within +30 μm to −20 μm, even vacuum-chucked the wafer will not crack. Wafers according to the present invention do not fracture even when masks for contact exposure are set onto the wafers. Since there is no warp, the mask pattern is accurately transferred onto the resist, and errors do not appear in the optical exposure pattern. These features improve device-fabrication yields.
[0080] Inasmuch as a damaged layer is exploited to eliminate warp, the damaged layer of the present invention remains behind to some extent. A maximum of 50 μm of the damaged layer along the back side, and a maximum of 10 μm of the layer along the front side will in some cases be present. The damaged layer along the front side is so thin as not to be a hindrance when fabricating devices. Even along the back side, since the damaged layer is 50 μm or less, disruptions, such as growth of cracks or incidents of fracturing, following from wafer-processing based operations do not arise.
[0081] What the present inventors discovered is that grinding a nitride substrate surface with grit having a coarse mesh produces a damaged layer and the damaged layer has a stretching effect on the surface, and that by means of etching to diminish the damaged layer this action that tends to stretch the surface is curtailed. Accordingly, a novel technique by the present invention is the production of a planar substrate with minimal warp by introducing a (grinding) damaged layer onto the front side/back side of a nitride substrate, and removing the layer in part.
[0082] When the warp His taken into consideration including its sign, front-side damaged layer introduction S and back-side etching T increase the warp H, while front-side etching U and back-side damaged layer introduction W decrease the warp H. This means:
H Graduated Increase Processes front-side damaged layer introduction S, back-side etching T, H Graduated Decrease Processes front-side etching U, back-side process- transformed layer introduction W.
With front-side damaged layer introduction S and front-side etching U being stand-alone processes they do not necessarily have to form a pair. Likewise, with back-side etching T and back-side damaged layer introduction W being stand-alone processes they do not necessarily have to form a pair. But because the etching process has to be for removing a damaged layer, front-side damaged layer introduction S has to go ahead of front-side etching U Likewise, back-side damaged layer introduction W has to precede back-side etching T.
[0083] Going a step further, the sign of these processes is taken to express increase/decrease in warp. Thus, S and T take positive values; U and W take negative values. Since the absolute value of the change in warp due to etching is smaller than that of change in warp due to a damaged layer, S+T is positive; U+W is negative. That is:
S>0; T>0 (1)
U<0; W<0 (2)
S+U> 0 (3)
W+T< 0 (4)
[0084] Letting the initial warp be H i and the final warp be H o , then fundamentally
H i +S+U+W+T=H o (5)
[0085] Ideally the final warp H o is 0, but there is an optimal range about 0, and it is satisfactory to have the range be
+30 μm≧H o ≧−20 μm (6)
Given the significance of Equation (5), what this means is that increasing the warp through front-side grinding (since S is positive), decreasing the warp by front-side grinding (since U is negative), decreasing the warp by back-side grinding (since W is negative), and increasing the warp by back-side grinding (since T is positive) produces an appropriate (from −20 μm to +30 μm) final warp H o . For the sake of simplicity, the final warp H o may be conceived of as being 0. Given the parameters in Equations (1) through (4), no matter what the initial warp H i , it should be possible to bring the final warp to 0, or else to within the appropriate range (6).
[0086] Nevertheless, the fact that the final thickness of the damaged layer along the front side is 10 μm or less imposes a restriction on S+U (positive value). In turn, the fact that the thickness of the damaged layer along the back side is 50 μm or less imposes a restriction on W+T (negative value).
[0087] Because on W+T can be a negative number whose absolute value is considerably large, implementations in which the initial warp H i is positive mean for the present invention that with the degree of freedom being especially large, the invention is more easily embodied.
[0088] When the initial warp H i is positive—i.e., when there is a convexity along the front side (Ga face)—then steps S and U can be omitted, and the warp can be curtailed simply according to
(H i >0) H i +W+T=H o (7)
In other words, this means that back-side grinding W and back-side etching T alone are sufficient. Moreover, if it is the case that change in warp can be accurately controlled by back-side grinding, then the back-side etching T may be omitted. That is, such cases make it that
(H i >0) H i +W=H o (8)
This maintains that warp can be eliminated by back-side grinding W alone (Embodiment 3).
[0089] In instances in which the initial warp H i is negative—i.e., when there is a concavity along the front side (Ga face)—then since H has to be increased, S and T (S, T both positive) are required. But given this, because T necessarily entails W, what can be omitted is only front-side etching U Then what is possible in such instances is
(H i <0) H i +S+W+T=H o (9)
This states that warp can be curtailed by means of front-side grinding S, back-side grinding W, and back-side etching T alone (Embodiment 2).
[0090] Nonetheless, in some cases in which the initial warp H i is negative, using all four steps will be advisable:
(H i <0) H i +S+U+W+T=H o (10)
This states that warp can be curtailed by means of front-side grinding S, front-side etching U, back-side grinding W, and back-side etching T alone (Embodiment 1).
[0091] Techniques (9) and (10) can be utilized even when the initial warp H i is positive. Accordingly, noting down altogether techniques possible by the present invention would be as follows.
(H i >0) H i +W=H o (8)
(H i >0) H i +W+T=H o (7)
(H i pos./neg.) H i +S+W+T=H o (9)
(H i pos./neg.) H i +S+U+W+T=H o (10)
EMBODIMENTS
[0092] GaN was grown by HVPE onto a GaAs base substrate as described earlier. The GaAs base substrate was removed to render freestanding, independent GaN crystals. The as-grown GaN crystal substrates thus obtained were 50.8 mm in diameter (2-inch) and 500 μm in thickness.
[0093] The substrates had a concavity along the front side (Ga face), with the absolute value of the warp being 40 μm or more (H<−40 μm). The surface roughness of the front side was R max 10 μm or more. The surface roughness and warp were measured employing a stylus surface profilometer (“Surfcom,” manufactured by Tokyo Seimitsu Co.).
[0094] The GaN crystals were affixed by means of wax to a platen made of alumina ceramic, and were then ground under the conditions tabulated below.
TABLE I GaN crystal substrate front-/back-side grinding conditions GaN Crystal Outer diameter: 2-inch (50.8 mm φ); Thickness: 500 μm Grinding surface (0001) plane; Ga face or else Nface Grinding device Rotary-type grinder Grinding parameters Grit dia.: 200 mm φ Grit/grain size: Diamond, #325 Working revs: 400 rpm Feed rate: 5 μm/min. Grinding slurry supply rate: 5 L/min.
[0095] The planarity (warp) of the GaN crystal substrate still affixed to the polishing platen immediately after grinding was ±2 μm, and the surface roughness R max was 0.5 μm. Because the polishing platen is perfectly flat, it stands to reason that warp in a substrate bound fast to the platen will be slight.
[0096] The polishing platen was heated to 100° C. to peel the GaN crystal substrate off the platen.
[0097] The GaN crystal substrate broken away from the polishing platen was ultrasonically cleansed in isopropyl alcohol. Warp in the GaN substrate in respective stages was then measured.
[0098] Grinding as just described was carried out on both the front side (Ga face) and back side (N face).
[0099] The grinding produced damaged layers. Arrangements were made to etch the substrate so as to remove the damaged layer at once following grinding. Although the N face (back side) could be wet-etched using KOH, on the Ga face (front side), inasmuch as wet etching is ineffectual, dry etching using a chlorine plasma was performed. Of course, dry etching the back side also is possible. The etching conditions were:
TABLE II Dry etching parameters Equipment Reactive ion etcher Gas Chlorine Chlorine flow rate 10 sccm Pressure during etch 1 Pa Plasma power Antenna: 300 W; Bias: 10 W
[0100] Either the front side or the back side may be ground first. For Procedure A and Procedure B below, the respective sequences are indicated. It is not necessary to set the procedure so that an etching operation always follows on a grinding operation; both substrate sides may be ground, following which both sides may then be etched (Procedure C and Procedure D).
[0101] Inasmuch as cleaning and drying are performed following the respective stages, such as when the substrate is broken away from the polishing platen, and after etching, herein they have been omitted.
[0102] Procedure A
Front-side grinding Front-side dry etch (chlorine plasma) Back-side grinding Back-side wet etch (KOH), or dry etch (chlorine plasma)
[0107] The procedural order written out in slightly more detail would be as follows.
[0108] Grow substrate→Affix to platen→Grind front side→Break away from (lift off of) platen→Dry-etch front side→Affix to platen→Grind back side→Break away from (lift off of) platen→Wet-etch or dry-etch back side.
[0109] Procedure B
Back-side grinding Back-side wet etch (KOH), or dry etch (chlorine plasma) Front-side grinding Front-side dry etch (chlorine plasma)
[0114] The procedural order written out in slightly more detail would be as follows.
[0115] Grow substrate→Affix to platen→Grind back side→Break away from (lift off of) platen→Wet-etch or dry-etch back side→Affix to platen→Grind front side→Break away from (lift off of) platen→Dry-etch front side.
[0116] Procedure C
Front-side grinding Back-side grinding Front-side dry etch (chlorine plasma) Back-side wet etch (KOH), or dry etch (chlorine plasma)
[0121] Procedure D
Back-side grinding Front-side grinding Back-side wet etch (KOH), or dry etch (chlorine plasma) Front-side dry etch (chlorine plasma)
[0126] In Embodiment 1 set forth below, Procedure A is adopted, with the substrate warp being measured in the post-grown free state, in the post-grinding bound state as adhered to the platen, in the free state after being broken away from the platen, in the free state following front-side etching, in the bound state as adhered to the platen following back-side grinding, and in the free state following back-side etching.
Embodiment 1
Concave Warp (H<0): Front-Side Grinding→Front-Side DE→Back-Side Grinding→Back-Side DE
[0127] The warp in the free state of a (2-inch φ, 500-μm thickness) GaN crystal from which the GaAs base substrate had been removed was H=−50 μm (front-side concavity). The back side was affixed to the polishing platen and the front side was ground. The grinding conditions were as described earlier. The absolute value of the post-grinding front-side warp in the GaN crystal as affixed in the bound state was no more than 1 μm. The warp in the GaN crystal in the free state as having been lifted off the platen was H=+30 μm.
[0128] This means that along the front side the crystal had gone convex. The reason for this is because a thick damaged layer had been introduced into the front side by the grinding, and the damaged layer generated stress that tended to stretch the front side. Because the presence of a damaged layer on the front side is not acceptable, the front side was given a dry etch (DE) with a chlorine plasma. Thereafter the warp proved to be H=+10 μm. Although the condition of convexity along the front side did not itself change, the amount of warp was reduced. In addition, the front side was affixed to the platen and the back side was ground. The grinding conditions were as described earlier. The post-grinding back-side warp in the GaN crystal as adhered fast to the platen was no more than 1 μm.
[0129] The warp in the GaN crystal in the free state as having been undone from the platen was −20 μm. The reason for this is because a damaged layer had been produced along the back side by the grinding, and the damaged layer acted to stretch that surface. The warp in the free state after the back side next had been dry-etched was H=−5 μm. This means that the warp had for the most part disappeared. This warp sufficiently satisfies according to the present invention the condition: +30 μm≧H≧−20 μm; it satisfies the more preferable condition: +20 μm≧H≧−10 μm; and in fact it satisfies the optimal condition: +10 μm≧H≧−5 μm.
[0130] Grinding gives rise to a damaged layer and since the layer pressingly stretches the ground surface, the warp changes to the opposite side. And the further significance is that when the damaged layer is removed by etching, the warp is curtailed in correspondence with the amount removed. In sum, what this means is that by combining grinding and etching, the warp can be reduced or eliminated.
TABLE III Embodiment 1 change in warp immediately after crystal growth, after front-side grinding, after lift-off, after front-side dry etch, after back-side grinding, after lift-off, and after back-side dry etch Stage Warp H(μm) Just after crystal-growth (free state) −50 After front-side grinding (bound state) 0 After lift-off (free state) +30 After front-side dry etch (free state) +10 After back-side grinding (bound state) 0 After lift-off (free state) −20 After back-side dry etch (free state) −5
Embodiment 2
Concave Warp (H<0): Front-Side Grinding→Back-Side Grinding→Back-Side DE
[0131] Embodiment 2 is one in which the front-side dry etch (DE) of Embodiment 1 was omitted.
[0132] The warp in the free state of a (2-inch φ, 500-μm thickness) GaN crystal from which the GaAs base substrate had been removed was H=− 50 μm (front-side concavity). The back side was affixed to the polishing platen and the front side was ground. The grinding conditions were as described earlier. The absolute value of the post-grinding front-side warp in the GaN crystal as affixed in the bound state was no more than 1 μm. The warp in the GaN crystal in the free state as having been lifted off the platen was H=+30 μm.
[0133] This means that along the front side the crystal had gone convex. The reason for this is because a thick damaged layer had been introduced into the front side by the grinding, and the damaged layer generated stress that tended to stretch the front side. No dry etch was performed on the front side, but the front side was affixed to the platen and the back side was ground. The grinding conditions were as described earlier. In the back-side grinding there were instance in which local cracking occurred. The post-grinding back-side warp in the GaN crystal as adhered fast to the platen was no more than 1 μm.
[0134] The warp in the GaN crystal in the free state as having been undone from the platen was −30 μm. The reason for this is because a damaged layer had been produced along the back side by the grinding, and the damaged layer acted to stretch that surface. The back side was next dry-etched. Thereafter the warp in the free state was H=−20 μm. This warp satisfies according to the present invention the condition: +30 μm≧H≧−20 μm. This is a warp range within which photolithography is possible. Of particular significance here is that because front-side etching was not carried out, a factor that makes H positive was diminished.
TABLE IV Embodiment 2 change in warp immediately after crystal growth, after front-side grinding, after lift-off, after back-side grinding, after lift-off, and after back-side dry etch Stage Warp H(μm) Just after crystal-growth (free state) −50 After front-side grinding (bound state) 0 After lift-off (free state) +30 After front-side dry etch (free state) — After back-side grinding (bound state) 0 After lift-off (free state) −30 After back-side dry etch (free state) −20
Embodiment 3
Convex Warp (H>0): Back-Side Grinding
[0135] The warp in the free state of a (2-inch φ, 500-μm thickness) GaN crystal from which the GaAs base substrate had been removed was H=+30 μm (front-side convexity). The crystal was affixed to a ceramic platen, and both sides were ground so as to lessen the damaged layer. That meant a fine-mesh grit was employed. The Ra was not more than 5 nm.
[0136] In this embodiment, warp could be eliminated without creating a front-side-ground damaged layer and without etching, which was simpler. The front side was affixed to the polishing platen and the back side was ground. The grinding conditions were as described earlier. The post-grinding back-side warp in the GaN crystal as adhered fast to the platen was no more than 1 μm. The warp in the GaN crystal in the free state as having been lifted off the platen was +10 μm. Because the warp was “+,” back-side etching was not performed. Significant in this embodiment—an instance in which the warp was convex—is that the warp could be curtailed simply by introducing a damaged layer into the back side.
TABLE V Embodiment 3 change in warp immediately after crystal growth, after back-side grinding, and after lift-off Stage Warp H(μm) Just after crystal-growth (free state) +30 After front-side grinding (bound state) — After lift-off (free state) — After front-side dry etch (free state) — After back-side grinding (bound state) 0 After lift-off (free state) +10 After back-side dry etch (free state) —
[0137] Herein, should the warp be negative after the back side is ground (convexity along back side), etching the back side to take away part of the damaged layer will bring the surface closer to planar (H→0).
[0138] Only selected embodiments have been chosen to illustrate the present invention. To those skilled in the art, however, it will be apparent from the foregoing disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. Furthermore, the foregoing description of the embodiments according to the present invention is provided for illustration only, and not for limiting the invention as defined by the appended claims and their equivalents. | In an independent GaN film manufactured by creating a GaN layer on a base heterosubstrate using vapor-phase deposition and then removing the base substrate, owing to layer-base discrepancy in thermal expansion coefficient and lattice constant, warp will be a large ±40 μm to ±100 μm. Since with that warp device fabrication by photolithography is challenging, reducing the warp to +30 μm to −20 μm is the goal. The surface deflected concavely is ground to impart to it a damaged layer that has a stretching effect, making the surface become convex. The damaged layer on the surface having become convex is removed by etching, which curtails the warp. Alternatively, the convex surface on the side opposite the surface having become convex is ground to generate a damaged layer. With the concave surface having become convex due to the damaged layer, suitably etching off the damaged layer curtails the warp. | 2 |
This is a continuation of application Ser. No. 292,165, filed Aug. 12, 1981.
BACKGROUND OF THE INVENTION
The present invention relates to a sliding type door assembly equipped with a brake mechanism.
FIGS. 1 to 3 show a conventional sliding type door assembly. A vehicle body B includes a rear outer panel 1 on which a channel-shaped guide rail 3 is bolted. A sliding type door D is equipped with a guide follower 4 at a rear end thereof which slides in guide rail 3. Sliding type door D can thus move along the guide rail.
A front end portion 3a of guide rail 3 is curved toward the inside of vehicle body B so as to close sliding door D when it comes in a position as shown in FIG. 2.
Guide follower 4 includes a base bracket 6, a roller bracket 8, a sliding roller 9 and a pair of guide rollers 10. Base bracket 6 is affixed to the rear end of door inner panel 5 of sliding door D. Roller bracket 8 is rotatably connected through a shaft 7 to the base bracket. Sliding roller 9 is rotatably supported by roller bracket 8 so that it can move on the bottom of guide rail 3. Guide rollers 10 are rotatably supported by roller bracket 8 and can rotate on a side portion of guide rail 3.
In the aforesaid conventional door assembly, sliding door D is closed without receipt of any braking force or the like. Thus, if a hand H contacts the sliding door (as shown in FIG. 3) when it is closed, a finger may be accidentally pressed between the sliding door and vehicle body B.
OBJECT OF THE INVENTION
The object of the present invention is to provide a sliding type door assembly for a vehicle wherein a door can be braked so that one or more fingers can be prevented from being pressed between the vehicle body and the door.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side view showing a conventional vehicle;
FIG. 2 is a sectional view taken along the line II--II in FIG. 1;
FIG. 3 is a sectional view taken along the line III--III in FIG. 1;
FIG. 4 is a perspective view showing a sliding type door assembly according to a preferred embodiment of the present invention;
FIG. 5 is a sectional view taken along the line V--V in FIG. 4;
FIG. 6 is a perspective view showing a further embodiment of the present invention;
FIG. 7 is a perspective view showing a sliding type door assembly according to another embodiment of the present invention;
FIG. 8 is a perspective view showing an essential portion of the sliding door assembly as shown in FIG. 7;
FIG. 9 is a sectional view taken along the line IX--IX in FIG. 8;
FIG. 10 is a perspective view showing a braking mechanism according to another embodiment of the present invention;
FIG. 11 is a sectional view taken along the line XI--XI in FIG. 10;
FIG. 12 is a perspective view showing a connecting means according to the present invention;
FIG. 13 shows a pair of handles according to another embodiment of the present invention; and
FIG. 14 is a sectional view taken along the line XIV--XIV in FIG. 14.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 4 to 6 show a first embodiment of the present invention. A guide follower 4 is attached to sliding type door D at the rear side portion thereof. A lock device (not shown) is provided in such a manner that door D can move along guide rail 3 fixed to the vehicle body by means of bolts. The construction thereof is conventional.
Guide follower 4 includes a base bracket 6, a roller bracket 8, a sliding roller 9 and a pair of guide sliders 10'. Base bracket 6 is affixed at the rear end of the inner panel of sliding door D although not shown. Roller bracket 8 is rotatably connected to base bracket 6 through a shaft 7. Slide roller 9 is rotatably supported by roller bracket 8 for rolling engagement with the bottom surface of guide rail 3. Guide sliders 10' are in contact with a side surface of guide rail 3. Bent portions 8a of roller bracket 8 are inserted into each guide slider 10'.
A conventional guide roller can be used in place of the guide slider 10'.
The guide follower 4 is equipped with a braking mechanism S. Braking mechanism S includes a brake arm 12, a brake shoe 14, a spring 13, and brake release flanges 20, 22. Brake arm 12 is rotatably attached to roller bracket 8 with a shaft 16. Brake shoe 14 is fixed to the front end of brake arm 12 and has a braking surface 14a which is curved to make complete contact corresponding with peripheral surface of the slide roller 9 (see FIG. 5). Brake shoe 14 is biased by spring 13 to normally contact the peripheral surface of slide roller 9. Brake release flanges 20, 22 are formed by bending the other end of brake arm 12 upwardly and downwardly, respectively.
Upwardly bent brake release flange 20 is engaged through an adjusting nut 24 with one end of an actuating or connecting rod 26. The other end of rod 26 is connected to a brake release handle 30 which is rotatably provided on a shaft 29' together with a door operation handle 28. In operation, clockwise rotation of brake release handle 30 (as shown by the arrow in FIG. 4) causes the brake arm 12 to turn counterclockwise by way of the rod 26. Thus, brake shoe 14 disengages from slide roller 9 so that the braking is released.
The downwardly bent brake release flange 22 functions as follows: As shown in FIG. 6, when guide follower 4 enters the curved portion of guide rail 3, the roller bracket 8 rotates around the shaft 7 to some minor degree. In response thereto, brake arm 12 engages base bracket 6 so that brake arm 12 rotates to disengage brake shoe 14 from slide roller 9.
Guide follower 4 enters the curved portion of guide rail 3 just before door D is closed, or immediately after it is closed. At that time, the braking is released.
While guide follower 4 slidably moves on guide rail 3 at its straight portion, flange 22 does not engage any members.
In the aforesaid embodiment flange 22 and base bracket 6 constitute an automatic brake release mechanism AB.
In operation, when door D moves from a closed to an open position, handle 28 is actuated to rotate counterclockwise so that the door lock device (not shown) unlatches. At that time, the brake release flange 22 is in the condition shown in FIG. 6. Brake shoe 14 is disengaged from slide roller 9 so that no braking force is exerted. After the door lock device is unlatched, door D is pulled in a given direction. Thus, the door moves along the curved portion of guide rail 3 to enter the straight portion of the guide rail. As the guide follower enters the straight portion, the engagement of flange 22 with base bracket 6 is released so that brake shoe 14 moves toward slide roller 9. At the same time, slide roller 9 moves away from brake shoe 14. Accordingly, brake shoe 14 slightly contacts slide roller 9 so that only a minor friction force is exerted thereon.
If brake release handle 30 is actuated together with door handle 28 when door D is opened, then no friction force is exerted.
When door D moves from its open position to the closed position, the door is braked to stop. Even if one or more fingers contact the rear end of the door in order to close it, the door cannot be closed because the slide roller 9 moves up on the curved braking surface of the brake shoe 14 so as to produce a large braking force.
Therefore, brake release handle 30 must be actuated to move brake shoe 14 away from slide roller 9 for door D to be closed.
At the curved portion of guide rail 3, as already stated, flange 22 engages base bracket 6 so that the braking is automatically released. Thus, the door D can be smoothly closed even if the brake release handle 30 does not operate.
The door D can be easily closed if the brake release handle 30 is continuously actuated until the curved portion of the guide rail 3 and thereafter released.
FIGS. 7 through 9 show a further embodiment of the present invention. A base bracket 120 and a roller bracket 122 supported rotatably thereby are provided at a rear portion of sliding door type door 101. A guide follower 130 is rotatably attached to roller bracket 122. The guide follower 130 moves along guide rail 110.
Guide follower 130 includes a slide roller 132 and a pair of guide sliders 134. Slide roller 132 moves on a channel 112 of guide rail 110 and particularly on a bottom portion 114 thereof. Guide sliders 134 engage side walls 116, 118 of guide rail 110. Slide roller 132 is supported through a shaft 124 on roller bracket 122. Guide sliders 134 are supported by a pair of projections 126 of roller bracket 122.
A brake device includes a braking mechanism 140 and a brake release handle 170. Braking mechanism 140 functions to normally brake the slide roller 132 so that door D is prevented from freely moving by means of its braking force. Brake release handle 170 is connected through a linkage or connecting rod 141 to braking mechanism 140 and supported rotatably by a shaft 160 which also rotatably supports a door operation handle 150. The brake release handle 170 has an operated portion 172 placed in parallel with and in cooperation with an operated portion 152 of the door operation handle 150.
The braking mechanism 140 includes a brake arm 143, a brake shoe 144, an operated portion 148 and a spring 149. Brake arm 143 is rotatably supported by roller bracket 122. Brake shoe 144 is fixed to one end 143a of arm 143 and normally engages the periphery of slide roller 132 to control rotation thereof. The operated portion 148 is formed as a flange at the other end 143b of arm 143 and engages the right end portion of linkage 41 with an adjustable nut 146. Spring 149 is wound around pin 142 to bias arm 143 so that brake shoe 144 engages slide roller 132.
In operation, to move door 1 from its closed position to its open position, door operation handle 150 and brake release handle 170 are manually actuated simultaneously in opposite directions A and A' (as shown in FIG. 8), respectively. As handle 150 turns, rod 154 moves in direction C so that a lock device (not shown) is unlatched. Thus, rotation of brake handle 170 causes the linkage or rod 141 to move in the direction opposite to direction C so that brake arm 143 can rotate in direction D against the biasing force of the spring 149. Brake shoe 144 moves away from slide roller 132 to release the braking action. During this operation, door 1 can be easily opened by moving the door in a given direction since no braking force is exerted on slide roller 132.
Even if the brake release handle 170 is not actuated, the door can be opened by actuating only door operation handle 150. As slide roller 132 moves away from brake shoe 144 when the door is opened, the braking force decreases to such an extent that the door can be opened.
In order to close the door in a normal manner, only brake release handle 170 can be rotated in direction A while door 1 is moved to close without receipt of any braking force.
The brake device prevents the door from closing. That is, as brake shoe 144 normally contacts the slide roller 132 under the biasing force of spring 149, slide roller 132 moves up on the curved portion of brake shoe 144 so that a large braking force is exerted on slide roller 132 as in the first embodiment.
The door can be stopped at any desired intermediate position between the closed and opened positions of the door. During closing or opening operation of the door, brake release handle 170 can be released to rotate to its original position so that brake shoe 144 suddenly engages slide roller 132, stopping the door.
FIGS. 10 and 11 show another embodiment of the present invention which is a modification of the embodiment shown in FIGS. 7 through 9. Like or corresponding parts or members are designated by the same reference numerals, and only modified portions thereof will be described.
A wedge member 180 is attached to one end 143a of brake arm 143 between one of guide sliders 134 and side wall 118 of the guide rail so that sliding of the guide slider can be controlled. Wedge member 180 engages a flat recessed portion 182 of guide slider 134.
In this embodiment, braking shoe 144 is omitted. Guide slider 134 provides the necessary braking action instead of slide roller 132.
FIG. 12 shows another embodiment of the present invention which is another modification of the embodiment shown in FIGS. 7 to 9. A single handle 150 is used commonly for both purposes of door operation and brake release. Handle 150 is connected not only through a linkage 154 to the lock device but also through linkage 141 and a conversion plate 190 to brake mechanism 140.
In operation, whenever the door is opened, the braking force is released. Whenever the door is closed, also, braking is released.
FIGS. 13 and 14 show another embodiment of the present invention. A handle 250 for operating a door is attached to a base plate 252 in such a manner that it can rotate about a pair of shafts 256. A hole 201C is formed in outer panel 201b of door 201. Base plate 252 is fixed at the periphery of hole 201C by means of bolts 254. An operation portion 258 and an actuating portion 259 of handle 250 are positioned at the opposite sides. Actuating portion 259 is connected to the door lock device by way of a remote control rod 260.
A brake release handle 262 is rotatably secured of the handle by shafts 256. An actuating portion 266 of handle 262 in opposition to an operation portion 264 thereof is connected to an end of a remote control rod 268. The other end of remote control rod 268 is connected to a driven portion of a brake arm as shown in FIGS. 4 and 8.
A return spring 276 is disposed between a seat 272 formed at inner portion 250a of door operation handle 250 and a seat 276 formed at the inner portion 262a of the brake release handle 262. Thus, both handles 262, 250 can return to their original positions by means of the biasing force of return spring 276.
In operation, when the door is opened, door operation handle 250 is rotated against the biasing force of return spring 276 in the direction of arrow Y (FIG. 14). At the same time, brake release handle 262 is rotated in the direction opposite arrow Y. The door lock device is unlatched to disengage from a striker (not shown) while brake arm 12 or 143 is actuated against the biasing force of spring 13 or 149 to release the braking mechanism. As the brake mechanism is released, the door can be smoothly opened.
It should be noted that the door can be smoothly opened even if only the door operation handle 150 is operated as above-stated.
The pitch L between bolts 254 for fastening base plate 252 can be set large because spring 272 is provided between both handles. For this reason, base plate 252 can be rigidly fixed. Also, the attachment hole or holes of the door panel can be small so that the cooling efficiency within the vehicle can increase. As the number of springs between both handles can be increased, the door can be surely prevented from accidentally opening. In case a coil spring is used, the handles can be easily assembled to facilitate automatic assembling. | A sliding type door assembly for a vehicle, includes a guide rail fixed to the body of the vehicle, a door moving along the guide rail between its closed position and rear most open position, a guide follower attached to the door in such a manner that the guide follower can follow the door along the guide rail when the door moves, a brake mechanism for applying the braking power to the door by controlling the movement of the guide follower in relation to the guide rail, and a brake release means connected to the brake mechanism for releasing the brake mechanism. | 4 |
FIELD OF THE INVENTION
[0001] This invention pertains to a method for selectively treating diseases caused by cells that express IL-13 receptor and particularly to a method of treating solid tumors containing such cells.
BACKGROUND OF THE INVENTION
[0002] Malignant glioma, including glioblastoma multiforme (GBM) and anaplastic astrocytoma (AA) occurs in approximately 17,500 patients annually in the United States. Despite an aggressive multimodal approach to its treatment, no curative therapy is known. Median survival expectation is 9-12 months from diagnosis for GBM and 24-48 months for AA. Despite numerous investigational trials, patients with a recurrence of malignant glioma after initial radiotherapy do not live long.
[0003] One approach to eradicating tumor cells is to target cytotoxic agents to the cells. To accomplish this, antibodies or growth factors that bind to cells can be attached to cytotoxic molecules. The binding sites on such cells are known as cell receptors. This method is selective in situations where the targeted receptors are present in substantially higher amounts on target cells than in normal cells. Selectivity is desirable as it minimizes toxicity to normal cells. Exceptionally high levels of the receptor for Interleukin-13 (“IL13R”) have been identified in a number of tumor cells, including malignant gliomas. In contrast, only a few types of normal cells express IL13R and only at low levels. Consequently, IL 13 when combined with a cytotoxic agent has the potential to be a highly effective therapeutic agent for the treatment of IL13R-expressing tumor cells.
[0004] To explore the efficacy of such an approach a recombinant fusion protein has been constructed. The fusion protein consists of a truncated bacterial toxin derived from Pseudomonas , PE38QQR, fused to IL13. This agent is more completely described and preliminary cytotoxicity studies can be found in Int. J. Cancer 92, 168-175, which is incorporated herein by reference in its entirety. Unfortunately, when this therapeutic agent is administered systemically, particularly for malignancies in the central nervous system such as malignant gliomas, the drug does not have suitable efficacy.
[0005] In general poor overall efficacy of systemic chemotherapy for central nervous system malignancies is attributable to the exclusion of most anti-tumor agents from the brain. Moreover, malignant cells evade treatment by invading brain tissue adjacent to a tumor where they are further sheltered from exposure to any drug that does pass through the blood brain barrier. Thus, even those drugs that do penetrate the blood brain barrier fail to become concentrated in brain tumors and are generally destined to be metabolized and produce undesirable side effects.
[0006] New methods are therefore needed that can be used to deliver tumor-targeting drugs directly to tumors, particularly brain tumors, to produce high drug levels within the tumor while minimizing systemic exposure. Ideally such methods will be useful for treating intra-cranial malignancies, such as glioma, in addition to other solid tumors.
[0007] The invention provides such a method and composition. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.
BRIEF SUMMARY OF THE INVENTION
[0008] A method of treating tumors that express a receptor for IL-13 is disclosed. The method involves directly introducing into such tumors a cytotoxin that targets the IL-13 receptor. The cytotoxic agent can be introduced by convection-enhanced delivery through a suitable catheter or by other means. Where a convection-enhanced catheter is employed, the method involves positioning the tip of a catheter at least in close proximity to the tumor. After the catheter is positioned, it is connected to a pump which delivers the active agent through the catheter tip to the tumor. A pressure gradient from the tip of the catheter is maintained during infusion.
DETAILED DESCRIPTION OF THE INVENTION
[0009] The present invention is directed to a method for killing a cell that expresses a receptor for interleukin 13 and that is located in a solid tissue comprising, inserting at least one catheter directly into the solid tissue and through the catheter administering a cytotoxic agent to the solid tissue under pressure at a flow rate of about 30 μl/h or more to about 1 ml/h for a predetermined period of time such that a portion of the cytotoxic agent contacts a cell that expresses a receptor for interleukin 13 in the solid tissue and kills the cell.
[0010] Any suitable cytotoxic agent that selectively targets tumors that contain cells on which IL-13 receptors reside can be used in practicing the present invention. Such agents typically will have at least two domains, a targeting domain and a cytotoxic domain.
[0011] Suitable targeting domains selectively bind the IL-13 receptor and will generally have an affinity constant for the IL-13 receptor that is at least 1/10,000 of the affinity of native IL-13. In addition, targeting domains must maintain their affinity for the IL-13 receptor when joined to the cytotoxic domain. Suitable targeting domains will include for example, IL-13 itself and its derivatives. Suitable IL-13 derivatives include genetically constructed derivatives and chemical derivatives. Genetic derivatives can include truncations, deletions, or mutations so long as a suitable binding affinity for IL-13 receptor is maintained. Similarly, chemical modifications of IL-13 include any chemical modifications that do not preclude binding of the targeting moiety to the IL-13 receptor in the cytotoxin.
[0012] Many toxin molecules are known and are suitable for use in the cytotoxic domain. Suitable toxins include pseudomonas exotoxin , ricin, diphtheria toxin, and the like. Suitable cytotoxic domains maintain their cytotoxicity when joined with the targeting domain in the cytotoxin. As with the targeting domain, derivatives of the cytotoxin, including genetic and chemical derivatives are also suitable for use so long as sufficient cytotoxicity is preserved in the ultimate cytotoxin molecule.
[0013] The targeting and cytotoxin domains can be joined by any suitable means that provides for retention of the targeting and cytotoxicity characteristics of the cytotoxin. For example, the two domains can be joined chemically such as through cysteine disulfide or other chemical conjugation methods. Desirably, the domains are joined at the the genetic level in a recombinant fusion protein, as is the case with IL13-PE38QQR.
[0014] For administration the drug can be dissolved in any suitable pharmaceutical excipient. Suitable excipients include standard solutions of phosphate-buffered saline, normal saline (0.9 wt. %) and preferably 0.2 wt. % human serum albumin in 0.9 wt. % saline.
[0015] Any disease caused by cells that express the well known IL-13 receptor can be treated by administration of IL13-PE38QQR. For example, malignant glioblastoma multiforme cells, astrocytoma cells, Kaposi sarcoma cells and renal cell carcinoma among other cells express the IL-13 receptor and can be treated. The method can be used to treat a variety of types of tumors, and is especially useful for treating brain tumors, brain stem tumors, and spinal cord tumors.
[0016] Any suitable method for delivering the cytotoxin to the tumor can be used. For example, tumors can be injected with the cytotoxin as through a syringe. Preferably however, the cytotoxin is administered through a catheter by inserting the catheter directly into tissue in the proximity of the tumor. Preferred catheters include those manufactured by Medtronic (e.g., Ventricular #41207, Ventricular #41101, Cardiac/peritoneal #43209, Peritoneal #22014, Peritoneal #22013, #10532, etc.), Phoenix Biomedical Corp (e.g., spiral-port ventricular catheter), and IGN. Other types of catheters (e.g., end-port catheters, side-port catheters, fish-mouth catheters, and the like) also can be employed.
[0017] In use, a catheter is joined with a pump that withdraws the cytotoxin from a container and produces enough pressure to cause the drug to flow through the catheter to the tumor cells at controlled rates. Any suitable flow rate can be used such that the tissue is not disrupted or, in the case of brain tissue, the intracranial pressure is maintained at suitable levels so as not to injure the brain tissue. For example flow rates of about 30 μL/h or more to about 1 ml/h are easily tolerated in brain tissue. Catheters for convection-enhanced drug delivery and general methods for administering drugs with such devices are known. See, e.g., U.S. Pat. No. 5,720,720; Am. J. Physiol. 277, R1218-1229; Proc. Nat'l Acad. Sci. (1994) 91, 2076-2080; J. Neurosurg. (1995) 82, 1021-1029. More than a single catheter can be used for the infusion if faster rates than can be achieved with a single catheter are desired. In addition, the treatments can be repeated by reinserting the catheters, if they have been removed, and producing a flow of the cytotoxin to the tumor or tissue around the tumor.
[0018] Penetration of the cytotoxin into the tissue is greatly facilitated by positive pressure infusion over a period of days, taking advantage of convection rather than diffusion to aid in drug delivery. This provides for a greater distribution of drug in the treatment area which increases the likelihood that a portion of the drug will come into contact with cells containing IL-13 receptors. When such a contact occurs, the IL-13 targeting domain is thought to bind to the IL-13 receptor. Subsequent to this binding event the cytoxin enters the cell and the toxin domain poisons the cell thereby causing cell death and obliteration of the disease caused by the cell.
[0019] Any suitable amount of drug that can be administered in this manner. Suitable amounts are amounts that are effective at retarding the growth of or eradicating the disease causing cells without causing an overabundance of undesirable side effects. For example, with IL13-PE38QQR as little as about 1 μg or more to about 1 mg can be administered in a single treatment. More preferably about 2 μg or more to about 600 μg, even more preferably about 4 μg or more to about 400 μg, and still more preferably about 5 fig or more to about 50 μg is administered.
[0020] Tumors can be resected prior to treatment with the drug or, alternatively, tumors can be treated with the drug and then resected. In some case the later procedure may result in the accumulation of necrotic tissue which can be removed. In either situation it is desirable to follow resection with a treatment with the drug so that any disease-causing cells that may have evaded resection and/or the initial drug treatment can be neutralized.
[0021] Recent preclinical data demonstrated that the molecular mechanisms of tumor cytotoxicity induced by IL-13PE38QQR includes the induction of apoptosis in tumor cells (Kawakami et al., Mol. Cancer Ther., 1, 999-1007 (2002)). The data that support this observation includes: (a) the time dependent induction of proapoptotic caspases 3, 8 and 9 in tumors treated with IL-13PE38QQR; (b) cleavage of procaspase-3 and poly(ADP-ribose) polymerase (PARP) and; (c) the release of cytochrome C from the mitochondria to the cytosol following injection of IL-13PE38QQR intratumorally. These data demonstrate the mechanisms for the anti-tumor activities of IL-13PE38QQR include the induction of tumor cell apoptosis. The following examples further illustrate the invention but, of course, should not be construed as in any way limiting its scope.
EXAMPLE 1
[0022] This example demonstrates an effective treatment for malignant glioblastoma multiforme. The method takes advantage of a therapeutic agent that targets receptors for interleukin-13 (IL-13R), an immunoregulatory Th2-derived cytokine, on glioblastoma multiforme cells. Interleukin-13 receptors are over-expressed on human glioblastoma cell lines and primary cell cultures. The cytotoxin comprises a fusion protein composed of human IL-13 and a mutated and truncated form of Pseudomonas exotoxin known as PE38QQR. Intratumoral injections of the IL-13 cytotoxin in concentrations of 50 and 100 μg/kg/day for five consecutive days into nude mice having subcutaneous U251 glioblastoma tumors caused a complete response (eradication of the tumor) in 80% and 100% mice, respectively. This response lasted for over eight months after the IL-13 cytotoxin therapy. Three alternate day intratumoral injections of the IL-13 cytotoxin at a dose of 250 μg/kg/day into subcutaneous U87 glioblastoma tumors also produced the same response in all mice.
[0023] Intraperitoneal injections of the IL-13 cytotoxin at 25 or 50 μg/kg/dose for five days, twice daily, caused a regression in U251 tumors of about 45% and 58% and caused a complete response in 1 of 5 and 2 of 5 of the treated animals, respectively. A 50 μg/kg intraperitoneal injection into nude mice having U87 xenografts caused a reduction in the tumor burden to one-half. In addition, daily intravenous injections of IL-13 cytotoxin at doses of 25 and 50 μg/kg for five days suppressed the growth of subcutaneous U251 tumors by 75% and 81% and provided a complete response in 1 of 6 animals in each group. The IL-13 cytotoxin therapy manifested no toxicity in any of the treated mice.
[0024] IL-13 cytotoxin was also directly injected into glioblastoma multiforme tumors xenografted into the right caudate nucleus of nude rat brain. A single injection of 33.3 μg/kg of IL-13 cytotoxin into intracranial tumors increased median survival by >20% compared to control rats.
EXAMPLE 2
[0025] This example demonstrates the maximum tolerated dose of recombinant ligand-targeted cytotoxin IL13- pseudomonas exotoxin 38QQR (IL13-PE38QQR) that can be delivered by a continuous 96 hour intratumoral infusion in patients with recurrent malignant gliomas. The treatment takes advantage of the high density of IL-13 specific receptors on high-grade glioma specimens. Tissue penetration in the brain of this macromolecule is facilitated by positive pressure infusion, taking advantage of convection. A total of 30 patients in groups of 3-6 were selected based on histologic confirmation of malignant glioma and radiographic evidence of recurrence measuring 1.0 to 5.0 cm in maximum diameter, KPS>60. A stereotaxic biopsy at study entry confirmed the presence of glioma. The IL13-PE38QQR was delivered via 2 intratumoral catheters at a rate of 0.2 ml/hr. The concentration of the IL13-PE38QQR in the infusate was increased in each group. Each patient received 2 treatments 8 weeks apart. Three patients have successfully completed both treatment courses at the starting concentration level of 0.125 μg/ml providing for a dose of 4.8 mg.
EXAMPLE 3
[0026] This example demonstrates positive-pressure microinfusion, also known as convection-enhanced delivery, of IL13-PE38QQR to control malignant glioma. Malignant glioma cells, but not normal brain cells, express IL-13 receptors and are thought to internalize IL 13-PE38QQR toxin, leading to tumor cell death.
[0027] This example further demonstrates the histologically-effective concentration (HEC). Tumor biopsy and placement of at least one intratumoral catheter is performed on Day 1 , and IL13-PE38QQR infusion is performed over 48 hrs at 400 μL/hr on Day 2-4. The tumor is resected on Day 8, with the goal to accomplish an “en-bloc” resection of the tumor with catheter in place. Tumor tissue is evaluated for evidence of a cytotoxic effect including changes in apoptotic index and proliferation rate, as well as necrosis adjacent to the catheter. Following the resection, two or three catheters are placed into brain adjacent to the tumor resection cavity. Post-resection infusion of 750 μL/hr total for 96 hrs is administered on Days 10 - 14 to treat any residual surviving glioma that has invaded adjacent brain tissue. Pre-and post-resection infusion starts with IL 13-PE38QQR concentrations of 0.25 μg/mL IL13-PE38QQR.
[0028] Pre-operative infusions were well-tolerated in five of six patients tested. In one patient, progressive tumor-related hemiparesis at study entry halted pre-operative drug infusion. In 2 patients, transient changes in affect and cognition were noted during the infusion. All resections and post-resection infusions were well tolerated. One of six patients receiving post-operative infusions at 0.25 μg/mL experienced steroid-responsive hemiparesis with MRI changes one month later. Tumor specimen in one patient after pre-operative IL13-PE38QQR infusion at 0.5 μg/mL reveals regional necrosis in an ovoid zone extending 2-2.5 cm from catheter tip, consistent with drug effect.
[0029] Dose limiting toxicity is defined as any Grade 3 or Grade 4 toxicity which is definitely or probably related to study drug. The maximum tolerated dose (“MTD”) is the dose-level below that which causes dose-limiting toxicity in two or more of up to six patients. Geographic necrosis is defined by loss of cellular integrity with eosinophilic staining or by complete cell loss. The finding of greater than about 90% of cells necrotic in the post-infusion specimen, as compared with the pre-infusion biopsy, in a radial distribution at least 2 cm from the catheter tip, demonstrates drug efficacy.
[0030] Patients are treated with the following concentrations of the drug: 0.2, 0.5, 1, 2, 3, 4, 6, and 8 by infusing the drug in a pharmaceutically acceptable excipient at a rate of 0.4 ml/h for 48 hours when treated prior to tumor resection. This provides doses of 5, 10, 20, 40, 60, 80, 120, and 150 μg. Post resection treatments with the drug is with identical concentrations administered more aggressively at 0.75 ml/min for 96 hours for total doses of 20, 40, 70, 140, 220, 290, 430, and 580 μg, respectively.
[0031] The following Table I demonstrates demographics of six patients:
TABLE I Date of Original Diagnosis Age Sex KPS Tumor Site; Pathology Cohort 1 Patient 1 Dec. 18, 2000 58 M 100 R temporo-parietal; GBM Patient 2 Feb. 5, 1997 (AA) 35 M 100 R temporal; GBM Patient 3 Sep. 28, 1998 33 F 100 R parieto-occipital; GBM Cohort 2 Patient 4 Dec. 1, 1999 53 F 80 L fronto-temporo-parietal; GBM Patient 5 Jan. 21, 1997 39 F L fronto-central; GBM Patient 6 Jan. 7, 2000 45 F 90 R fronto-temporal; GBM
[0032] The following Table II demonstrates the toxicity profile and efficacy of the drug treatment when administered prior to tumor resection:
TABLE II Pre-Resection IL13-PE38QQR Concentration Toxicities of Pre-Resection (μg/mL) Infusion Pathology at Resection Cohort 1 Patient 1 0.25 Mildly decreased cognition No definite necrosis during infusion Patient 2 0.25 Flattened affect & decreased No definite necrosis cognition during infusion Patient 3 0.25 Transient field cut No definite necrosis Cohort 2 Patient 4 0.5 None 2 × 2.5 oval region of necrosis around catheter Patient 5 0.5 Increased R hemiparesis; Fragmentary; insufficient infusion halted dose Patient 6 0.5 None Necrosis, but resection suboptimal for anatomy
[0033] Table II shows that 0.25 μm/ml of the drug is infused intratumorally prior to tumor resection, the treatment was well tolerated. When 0.5 μg/ml of the drug was administered the treaetment was well tolerated and demonstrated efficacy as shown by tumor necrosis.
[0034] The following Table III demonstrates the toxicity profile and efficacy of the drug treatment when administered after tumor resection:
TABLE III IL13-PE38QQR Toxicities of Concentration Post-Resection (μg/mL) Infusion Surgical Issues Cohort 1 Patient 1 0.25 None Post-op field cut Patient 2 0.25 None Patient 3 0.25 None Only one catheter usable post-op, run at 400 μL/hr Cohort 2 Patient 4 0.25 Transient Catheter blockage severe Rt delayed post-op hemiparesis infusion by 1 day with abnormal MRI at week 5 Patient 5 0.25 None Patient 6 0.25 None
[0035] Table III shows that 0.25 μm/ml of the drug is infused into the situs of the tumor after tumor resection, the treatment was well tolerated. When 0.5 μg/ml of the drug was administered the treaetment was well tolerated and demonstrated efficacy as shown by tumor necrosis.
[0036] Table IV shows that when 0.25 lm/ml of the drug is infused into the situs of the tumor after tumor resection, the treatment was well tolerated. When 0.5 μg/ml of the drug was administered the treatment was well tolerated and demonstrated efficacy as shown by tumor necrosis.
TABLE IV Study Entry Progression-Free Overall Survival Date Duration (wks) Duration (wks) Cohort 1 Patient 1 Jun. 5, 2001 22+ 22+ Patient 2 Jun. 13, 2001 9 21+ Patient 3 Jun. 20, 2001 pend 20+ Cohort 2 Patient 4 Aug. 9, 2001 10 13+ Patient 5 Aug. 20, 2001 pend 12+ Patient 6 Aug. 20, 2001 11+ 11+
[0037] This example has demonstrated that direct intratumoral infusion of IL13-PE38QQR is well tolerated. Direct intratumoral infusion followed by resection is an efficacious treatment for IL-13-expressing brain tumors. IL13-PE38QQR at concentrations of 0.5 μg/mL is cytotoxic for malignant glioma. In addition, post-operative infusion of IL13-PE38QQR into the brain adjacent to resected tumors is well-tolerated such that malignant glioma can be efficaciously treated by direct infusion with IL13-PE38QQR after resection.
EXAMPLE 4
[0038] In preclinical studies, intracerebral injection of IL13-PE38QQR into rat brain was without neurotoxicity at concentrations up to 100 μg/mL. In this trial, the starting concentration is 0.5 μg/mL. Since many glioma cell lines are inhibited at concentrations of 1-10 ng/mL, this regimen could provide a therapeutic dose to tumor.
EXAMPLE 5
[0039] In one clinical glioma study intracerebral injection of IL13-PE38QQR is accomplished using a daily volume of 4.8 mL/catheter (0.2 mL/hr×24 hours), and total infused volume of 38.4 mL/course was held constant. There was a 96 hour infusion at weeks 1 and 9, with the dosing over this period according to the following table:
TABLE V Dose level Dose (μg/ml) Total Dose (μg) 1 0.125 4.8 2 0.25 9.6 3 0.5 19.2 4 1.0 38.4 5 2.0 76.8 6 4.0 153.6 7 6.0 230.4 8 9.0 345.6 9 12.0 460.8
[0040] This study currently is at dose level 4, and data generated to date are presented on the following four pages:
Cohort #1: 0.125 μg/mL for 96 hours, Week 1 and 9 Radiographic Patient #; Date of Related AEs Related AEs and/or Initials; Age; Study Infusion #1 Grade ≧ 2 and Infusion #2 Grade ≧ 2 and Pathology Date of Sex; Dx Entry Date; Dose SAEs: Weeks 1-8 Date; Dose SAEs: Weeks 9-17 Response Progression Comments #1001; CT Nov. Nov. 28, 2000- — Jan. 23, 2001- — — Mar. 15, 2001 Last Follow-Up: 42yoM; 27, Dec. 2, 2000; Jan. 27, 2001; PFS: 15 weeks Sep. 27, 2002 High grade 2000 0.125 μg/mL 0.125 μg/mL Survival: glioma 95+ Weeks #1002; RS Feb. 19, Feb. 20, 2001- Abnormal vision; Apr. 17, 2001- Brain edema — May 28, 2001 Date of Death: 33yoM; 2001 Feb. 24, 2001; Brain edema Apr. 21, 2001; (SAE, Week 14, PFS: 14 weeks Nov. 20, 2001 Malignant 0.125 μg/mL (SAE, Week 1, 0.125 μg/mL May 25, 2001); Survival: giloma Feb. 26, 2001); Stupor (SAE, 39 weeks Headache; Week 14, May Nausea; Vomiting 25, 2001) #1003; JC Mar. 5, Mar. 6, 2001- Aphasia; Cranial May 1, 2001- Aphasia (SAE, — Jun. 28, 2001 Date of Death: 55yoM; 2001 Mar. 10, 2001; nerve neuropathy; May 5, 2001; Week 11, PFS: 16 weeks Jul. 10, 2001 Malignant 0.125 μg/mL Motor neuropathy 0.125 μg/mL May 21, 2001); Survival: glioma Confusion (SAE, 18 weeks Week 11, May 21, 2001); Hemiparesis (SAE, Week 11, May 21, 2001); #2004; JG May 25, May 26, 2001- Hemiparesis NA/CR Heart arrest Pathologic — Date of Death: 51yoM; 2001 May 30, 2001; (SAE, Week 7, (SAE, Week 13, CR at Week 7 Aug. 23, 2001 Recurrent 0.125 μg/mL Jul. 10, 2001) Aug. 23, 2001); Survival: glioblastoma 13 weeks #5005; TW Jul. 10, Jul. 13, 2001- — NA/PR — Radiographic Mar. 18, 2002 Last Follow-Up: 41yoM 2001 Jul. 17, 2001; PR at Week 9 PFS: 35 weeks Sep. 27, 2002 Malignant 0.125 μg/mL Survival: astrocytoma 63+ weeks #5006; TD Oct. 23, Oct. 25, 2001- — NA/PD — — Jan. 7, 2002 Date of Death: 52yoM 2001 Oct. 29, 2001; PFS: 10 weeks Jul. 24, 2002 Recurrent 0.125 μg/mL Survival: glioblastoma 39 weeks
[0041]
Cohort #2: 0.25 μg/mL for 96 hours, Week 1 and 9
Related AEs
Radiographic
Patient #;
Date of
Grade ≧ 2
Related AEs
and/or
Initials; Age;
Study
Infusion #1
and SAEs:
Infusion #2
Grade ≧ 2 and
Pathology
Date of
Sex; Dx
Entry
Date; Dose
Weeks 1-8
Date; Dose
SAEs: Weeks 9-17
Response
Progression
Comments
#1007; JK
Dec. 18,
Dec. 19, 2001-
Embolus
NA/PD
—
—
Feb. 8, 2002
Resected on
51yoF;
2001
Dec. 23, 2001
Lower
PFS: 7 weeks
Feb. 8, 2002;
Anaplastic
0.25 μg/mL
Extremity
Date of Death:
Astrocytoma
(SAE, Week
Feb. 27, 2002
7, Feb. 2,
Survival:
2002)
10 weeks
#2008; MA
Jan. 9, 2002
Jan. 10, 2002-
Pneumocephaly
Withdrew
Back Pain (SAE,
—
—
Prior SRT
52yoF;
Jan. 14, 2002
SAE, Week 2,
Consent
Week 9, Mar. 12,
Last Follow-Up:
Malignant
0.25 μg/mL
Jan. 17, 2002)
2002); Motor
Sep. 27, 2002
Glioma
Neuropathy (SAE,
Survival:
Week 9,
37+ weeks
Mar. 12, 2002)
#1009; AS;
Jan. 28,
Jan. 29, 2002-
Aphasia;
NA/PD
—
—
Mar. 26, 2002
Last Follow-Up:
46yoM;
2002
Feb. 2, 2002;
Thrombosis
PFS: 8 weeks
Sep. 27, 2002
Recurrent
0.25 μg/mL
(SAE,
Survival:
Glioma
Week 7,
34+ weeks
Mar. 15, 2002)
[0042]
Cohort #3: 0.5 μg/mL for 96 hours, Week 1 and 9
Radiographic
Patient #;
Date of
Related AEs
Related AEs
and/or
Initials; Age;
Study
Infusion #1
Grade ≧ 2 and
Infusion #2
Grade ≧ 2 and
Pathology
Date of
Sex; Dx
Entry
Date; Dose
SAEs: Weeks 1-8
Date; Dose
SAEs: Weeks 9-17
Response
Progression
Comments
#2010; DT;
Mar. 22,
Mar. 23, 2002-
Deep
NA/SAE
Infection (SAE,
—
—
Last Follow-Up:
46yoM;
2002
Mar. 27, 2002
Thrombophlebitis
Week 9,
Sep. 27, 2002
Recurrent
0.5 μg/mL
(SAE, Week 7,
May 21, 2002);
Survival:
Astrocytoma
May 9, 2002)
Deep Vein
27+ weeks
Thrombosis (SAE,
Week 9,
May 21, 2002)
#2011; RT;
Mar. 27,
Mar. 28, 2002-
—
NA
Ataxia (SAE, Week
—
—
Last Follow-Up:
67yoM;
2002
Apr. 1, 2002
12, Jun. 18, 2002);
Sep. 27, 2002
Recurrent
0.5 μg/mL
Cerebral Edema
Survival:
Residual
(SAE, Week 12,
27+ weeks
Malignant
Jun. 18, 2002);
Glioma
Confusion;
Hemiparesis (SAE,
Week 12,
Jun. 18, 2002);
Stupor (SAE, Week
12, Jun. 18, 2002)
#5012; TH;
Apr. 4,
Apr. 5, 2002-
—
Jun. 5, 2002-
Ataxia;
—
Jul. 8, 2002
Only 1
43yoM;
2002
Apr. 9, 2002
Jun. 9, 2002
Hydrocephalus
PFS: 13 weeks
Catheter used.
Residual
0.5 μg/mL
0.5 μg/mL
(SAE, Week 17,
Last Follow-Up:
Recurrent
Jul. 29, 2002)
Sep. 27, 2002
Malignant
Survival:
Glioma
25+ weeks
[0043]
Cohort #4: 1.0 μg/mL for 96 hours, Week 1 and 9
Radiographic
Patient #;
Date of
Related AEs
Related AEs
and/or
Initials; Age;
Study
Infusion #1
Grade ≧ 2 and
Infusion #2
Grade ≧ 2 and
Pathology
Date of
Sex; Dx
Entry
Date; Dose
SAEs: Weeks 1-8
Date; Dose
SAEs: Weeks 9-17
Response
Progression
Comments
#3013; AR;
Jul. 15,
Jul. 16, 2002-
Hallucinations;
Sep. 10, 2002-
—
—
—
Last Follow-Up:
31yoM;
2002
Jul. 20, 2002
Headache;
Sep. 14, 2002
Sep. 27, 2002
GBM
1.0 μg/mL
1.0 μg/mL
Survival
10+ weeks
EXAMPLE 6
[0044] In another clinical glioma study intracerebral injection of IL13-PE38QQR is accomplished using a 48 hour infusion of 400 μL/hour), starting one week prior to tumor resection, and a 96 hour infusion (750 μL/hour) was begun two days after tumor resection. The treatment was run in three stages as follows:
Stage 1 Dosage Pre-Resection Post-Resection level Dose (μg/ml) Total dose (μg) Dose (μg/ml) Total dose (μg) 1 0.25 4.8 0.25 18.0 2 0.5 9.6 0.25 18.0 3 1.0 19.2 0.25 18.0 4 2.0 38.4 0.25 18.0 Dosage level Dose (μg/ml) Total dose (μg) Stage 2 (Post Resection) 1 0.5 36.0 2 1.0 72.0 3 2.0 144.0 Stage 3 (Post Resection) 1 5 90 2 6 108 3 7 126
[0045] This study currently is at dose level 1 of Stage Two, and data generated to date ed on the following five pages:
Cohort #1: 0.25 μg/mL Pre-Resection; 0.25 μg/mL Post-Resection Related Related AEs AEs Patient #; Biopsy/ Grade ≧ 2 Grade ≧ 2 Initials; Age; Date of Catheter Infusion #1 and SAEs: Infusion #2 and SAEs: Date of Sex; Dx Diagnosis Date Date; Dose Infusion 1 Pathology Date; Dose Infusion 2 Progression Comments #101; DMH Dec. 8, Jun. 5, Jun. 6, 2001- Headache No evidence Jun. 14, 2001- Fatigue — Mild hyponatremia; 58yoM; 2000 2001 Jun. 8, 2001; of necrosis Jun. 18, 2001; visual deficit post-op R-temporal 0.25 μg 0.25 μg Last Follow-up: GBM Sep. 27, 2002 Progression Free Survival: 68+ Weeks #102; HJM Feb. 5, Jun. 13, Jun. 14, 2001- Confusion No evidence Jun. 22, 2001- Brain Aug. 15, 2001 Partial seizures 35yoM; 1997 2001 Jun. 16, 2001; of necrosis Jun. 26, 2001; edema; PFS: 9 Weeks increased; R-temporal [initial 0.25 μg 0.25 μg Headache; quadrantanopia; GBM AA] Pain Progressive Disease Died: Mar. 13, 2002 Survival: 39 Weeks #103; CGM Sep. 28, Jun. 20, Jun. 21, 2001- — No evidence Jun. 29, 2001- — Sep. 26, 2001 Hemiparesis; 33yoF; 1998 2001 Jun. 23, 2001; of necrosis Jul. 3, 2001; PFS: 14 Weeks Paresthesia; R-parieto- 0.25 μg 0.25 μg Post-op: 1 catheter occipital GBM used, was run at 400 μL/hr; ? PD vs. translent enhancement Last Follow-up: Sep. 27, 2002 Survival: 62+ Weeks
[0046]
Cohort #2: 0.5 μg/mL Pre-Resection; 0.25 μg/mL Post-Resection
Related AEs
Patient #;
Biopsy/
Grade ≧ 2
Initials; Age;
Date of
Catheter
Infusion #1
and SAEs:
Sex; Dx
Diagnosis
Date
Date; Dose
Infusion 1
Pathology
#201; JAR;
Nov. 30,
Aug. 9,
Aug. 10, 2001-
—
2 × 2.5 cm
53yoF;
1999
2001
Aug. 12, 2001;
oval necrosis
L Fronto-
0.5 μg
tempor-parietal
GBM
#202; NWC;
Dec. 1,
Aug. 20,
Aug. 21, 2001-
—
Suboptimal
45yoF;
1999
2001
Aug. 23, 2001;
specimen w/
R Fronto-
0.5 μg
necrosis
temporal GBM
#104; TMW
Jan. 22,
Aug. 20,
Aug. 22, 2001-
Headache;
Fragmentary
38yoF;
1997
2001
Aug. 23, 2001;
Hemiparesis
L Fronto-
0.5 μg
(SAE, before
parietal GBM
Insufficient
first infusion,
dose,
Aug. 21, 2001);
replaced in
Speech
enrollment
disorder
#105; S-C
Oct. 16,
Oct. 30,
Oct. 31, 2001-
Headache
—
51yoF;
2000
2001
Nov. 2, 2001;
GBM
0.5 μg
#203; JWS
Dec. 14,
Nov. 5,
Nov. 6, 2001-
—
Major (>75%)
46yoM;
1999
2001
Nov. 8, 2001;
necrosis 1 cm
GBM
0.5 μg
from tip
Patient #;
Related AEs
Initials; Age;
Infusion #2
Grade ≧ 2 and
Date of
Sex; Dx
Date; Dose
SAEs: Infusion 2
Progression
Comments
#201; JAR;
Aug. 18, 2001-
Hemiparesis
Oct. 16, 2001
Catheter kinking delayed
53yoF;
Aug. 23, 2001;
(SAE, Sep. 11,
PFS: 9 Weeks
post-op infusion;
L Fronto-
0.25 μg
2001); Seizure
Died Jan. 3, 2002
tempor-parietal
(SAE, Sep. 11,
Survival: 21 weeks
GBM
2001)
#202; NWC;
Aug. 28, 2001-
Depression; Ear
Oct. 24, 2001
AR25 headache/sinusitis.
45yoF;
Sep. 1, 2001;
disorder;
PFS: 9 Weeks
Died Dec. 23, 2001
R Fronto-
0.25 μg
Fatigue;
Based on
Survival: 17 weeks
temporal GBM
Headache;
Clinical
Sensory
Evidence
neuropathy
#104; TMW
Aug. 29, 2001-
Amnesia; Ataxia;
Sep. 26, 2001
Post-op 2 catheters used
38yoF;
Sep. 2, 2001;
Headache;
PFS: 5 Weeks
tolerated well. Patient
L Fronto-
0.25 μg
Incoordination;
replaced in enrollment b/c
parietal GBM
Sensory
did not receive enough
neuropathy;
pre-infusion drug
Died Mar. 11, 2002
Survival: 28 Weeks
#105; S-C
Nov. 8, 2001-
Sensory
Dec. 31, 2001
Tissue Enhancement (PD
51yoF;
Nov. 12, 2001;
Neuropathy
PFS: 8 Weeks
vs. Drug)
GBM
0.25 μg
Last Follow-up: Sep. 27, 2002
Survival: 47+ Weeks
#203; JWS
Nov. 13, 2001-
—
Feb. 22, 2002
Tissue Enhancement (PD
46yoM;
Nov. 17, 2001;
PFS: 15 Weeks
vs. Drug)
GBM
0.25 μg
Resected Feb. 25, 2002.
Last Follow-up: Sep. 27, 2002
Survival: 46+ Weeks
[0047]
Cohort #3: 1.0 μg/mL Pre-Resection; 0.25 μg/mL Post-Resection
Related AEs
Patient #;
Biopsy/
Grade ≧ 2
Related AEs
Initials; Age;
Date of
Catheter
Infusion #1
and SAEs:
Pathol-
Infusion #2
Grade ≧ 2 and
Date of
Sex; Dx
Diagnosis
Date
Date; Dose
Infusion 1
ogy
Date; Dose
SAEs: Infusion 2
Progression
Comments
#301; MJS
Mar. 14,
Feb. 8,
Feb. 9, 2002-
—
1.0 cm
Feb. 16, 2002-
Pulmonary
Jul. 24, 2002
Last Follow-up:
69yoF;
2000
2002
Feb. 11, 2002;
necrosis
Feb. 20, 2002;
Emboius (SAE,
PFS:
Sep. 27, 2002
GBM
1.0 μg
0.25 μg
Apr. 21, 2002)
23 Weeks
Survival:
33+ Weeks
#401; RRL
Aug. 21,
Feb. 27,
Feb. 27, 2002-
Speech
—
Mar. 7, 2002-
Facial Paralysis;
Jul. 3, 2002
Last Follow-up:
57yoM;
2001
2002
Mar. 1, 2002;
Disorder
Mar. 10, 2002;
Dehydration
PFS:
Sep. 27, 2002
Grade 3 AA
1.0 μg
0.25 μg
(SAE, Apr. 25,
18 Weeks
Survival:
2002)
30+ Weeks
#402; RKW
Mar. 24,
Mar. 21,
Mar. 22, 2002-
Aphasia;
—
Apr. 1, 2002-
CSF leakage f/u
Jun. 21,
Last Follow-up:
49yoM;
1996
2002
Mar. 24, 2002;
Headache;
Apr. 4,
(SAE, Mar. 30,
2002 PFS:
Sep. 27,
Anaplastic
1.0 μg
CSF
2002; 0.25 μg
2002); Headache;
13 Weeks
2002
Oligo-
Drainage r/t
Pneumocephalus
Survival:
dendroglioma
(SAE, Mar.
(SAE, Apr. 10,
27+ Weeks
30, 2002);
2002);
Seizure;
Meningitis (SAE,
Sensory
Apr. 15, 2002);
Neuropathy
Cranlotomy Flap
Edema (SAE,
Apr. 23, 2002);
Pulmonary
Embolus (SAE,
May 11, 2002)
#106; HLW
Apr. 9,
Mar. 26,
Mar. 27, 2002-
—
—
Apr. 4, 2002-
Headache; Motor
—
Last Follow-up:
52yoM;
2000
2001
Mar. 29, 2002;
Apr. 8, 2002;
Neuropathy;
Sep. 27, 2002
Anaplastic
1.0 μg
0.25 μg
Seizure: Sensory
Progression
Oligo-
Neuropathy;
astrocytoma
Broken Leg
26+ Weeks
(SAE,
Aug. 21, 2002)
[0048]
Cohort #4: 2.0 μg/mL Pre-Resection; 0.25 μg/mL Post-Resection
Patient #;
Biopsy/
Related AEs
Pa-
Related AEs
Initials; Age;
Date of
Catheter
Infusion #1
Grade ≧ 2 and
thol-
Infusion #2
Grade ≧ 2 and
Date of
Sex; Dx
Diagnosis
Date
Date; Dose
SAEs: Infusion 1
ogy
Date; Dose
SAEs: Infusion 2
Progression
Comments
#107; KJN
Jan. 3,
May 14,
May 15, 2002-
—
—
May 23, 2002-
—
—
Last Fallow-up:
24yoF;
2002
2002
May 17, 2002;
May 27, 2002;
Sep. 27, 2002
GBM
2.0 μg
0.25 μg
Progression
Free Survival:
19+ Weeks
#302; PCJ
—
May 17,
May 18, 2002-
Hyponatremia
—
May 25, 2002-
CSF Leakage
Aug. 22, 2002
Died:
48yoM;
2002
May 20, 2002;
(SAE, Week 1,
May 29, 2002;
(SAE, Week 6,
PFS:
Sep. 25, 2002
GBM
2.0 μg
May 21, 2002);
0.25 μg
Jun. 22, 2002);
14 Weeks
Survival:
Headache (SAE.
Expressive
18 Weeks
Week 1,
Dysphasia (SAE,
May 21, 2002);
Week 11,
Vomiting (SAE,
Jul. 26, 2002)
Week 1,
May 21, 2002)
#303; DMD
Oct. 18,
Jun. 5,
Jun. 6, 2002-
—
—
Jun. 13, 2002-
—
Aug. 6, 2002
Last Follow-up:
43yoM;
2001
2002
Jun. 8, 2002;
Jun. 17, 2002;
PFS:
Sep. 27, 2002
GBM
2.0 μg
0.25 μg
9 Weeks
Survival:
16+ Weeks
[0049]
Cohort #5: 0.5 μg/mL Post-Resection
Patient #;
Resection/
Post Resection
Initials; Age;
Date of
Catheter
Infusion
Infusion Related AEs Grade ≧ 2 and
Date of
Sex; Dx
Diagnosis
Data
Date; Dose
SAEs
Progression
Comments
#204; CAM
Apr. 3,
Jul. 24, 2002
Jul. 26, 2002-
Pulmonary Embolism (SAE, Week 2,
Aug. 19, 2002
Last Follow-up: Sep. 27, 2002
60yoM;
2002
Jul. 30, 2002;
Jul. 31, 2002); Deep Vein Thrombosis
PFS: 3 Weeks
Survival: 9+ Weeks
GBM
0.5 μg
(SAE, Week 2, Aug. 2, 2002)
#205; LJP
Jan. 8,
Jul. 29, 2002
Jul. 31, 2002-
Thrombosis (SAE, Week 2, Aug. 8, 2002);
—
Last Follow-up: Sep. 27, 2002
56yoM;
2002
Aug. 4, 2002;
Hemiparesis (SAE, Week 8, Sep. 17, 2002)
Progression Free Survival: 9+
GBM
0.5 μg
Weeks
#108; J-V
Apr. 3,
Jul. 29, 2002
Jul. 31, 2002-
—
—
Last Follow-up: Sep. 27, 2002
47yoM;
2002
Aug. 4, 2002;
Progression Free Survival: 9+
GBM
0.5 μg
Weeks
EXAMPLE 7
[0050] In another clinical study intracerebral injection of IL 13-PE38QQR is accomplished using escalating infusion duration from 4 days (51.8 mL) to a maximum of 7 days (90.7 mL), to identify a MTD based on infusion duration; infusion rate held constant at 540 mL/hr (total) as follows:
Duration Dose level Conc. (μg/μL) (Days) Total Dose (μg) Increment (%) 1 .05 4 25.9 — 2 .05 5 32.4 25 3 .05 6 38.9 20 4 .05 7 45.4 16.7
[0051] A second protocol is employed in which concentration escalated from 1.0 a maximum of 4.0 mg/mL (assuming 7-day infusion) to identify a MTD based on ion; infusion rate held constant at 540 mL/hr (total) as follows:
Dose level Conc. (μg/μL) Total Dose (μg) Increment (%) 1 1.0 90.7 100 2 2.0 181.4 100 3 3.0 272.2 50 4 4.0 362.8 33
[0052] This study currently is at dose level 2, and data generated to date are presented lowing two pages:
Cohort #1: 0.5 μg/mL × 4 Days Patient #; Biopsy/ Related AEs Initials; Age; Date of Catheter Pre-resection Date of Grade ≧ 2 Date of Sex; Dx Diagnosis Date Infusion Date Resection and SAEs Pathology Progression Comments 0110-1101; Apr. 28, 1992 Jul. 30, 02 Jul. 31, 2002 Aug. 13, 2002 Seizure — — — JJK; 48 yoF; (Grade 2); Anaplastic Headache Glioma (Grade 2) 0108-1102; Aug. 8, 2001 Aug. 5, 2002 Aug. 6, 2002 Aug. 19, 2002 — — — — B-C; 56 yoM; Glioblastoma 0108-1103; Jul. 9, 2001 Aug. 12, 2002 Aug. 13, 2002 Aug. 26, 2002 — — — — Y-E; 54 yoM; Glioblastoma Multipforme
[0053]
Cohort #2: 0.5 μg/mL × 5 Days
Patient #;
Biopsy/
Pre-resection
Initials; Age;
Date of
Catheter
Infusion
Date of
Related AEs
Date of
Sex; Dx
Diagnosis
Date
Date
Resection
Grade ≧ 2 and SAEs
Pathology
Progression
Comments
0108-1201;
April
Sep. 30, 2002
Oct. 1, 2002
Oct. 14, 2002
—
—
—
—
I-P; 35 yoF;
1999
Projected
GBM
0108-1202;
March
Sep. 30, 2002
Oct. 1, 2002
Oct. 14, 2002
—
—
—
—
Z-F; 61 yoM;
2002
Projected
GBM
[0054] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
[0055] The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
[0056] Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Of course, variations of those preferred embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context. | A method of treating tumors that express a receptor for IL-13 is disclosed. The method involves directly introducing into the tumor a cytotoxin that targets the IL-13 receptor. The cytotoxic agent can be introduced by convection-enhanced delivery through a suitable catheter or by other means. Where a convection-enhanced catheter is employed, the method involves positioning the tip of a catheter at least in close proximity to the tumor. After the catheter is positioned, it is connected to a pump which delivers the active agent through the catheter tip to the tumor. A pressure gradient from the tip of the catheter is maintained during infusion. | 0 |
This application is a continuation of application Ser. No. 800,262, filed on Nov. 21, 1985 now abandoned.
The present invention relates to a semiconductor memory device, particularly to a MOS static memory device of high density and low power consumption.
Among the conventional MOS static memory cells, the Japanese Patent Laid Open Kokai No. 53-148989 is known as one in which the load consists of resistance. The circuit of this laid-open patent is shown in FIG. 1. In the figure, numerals 1-4 designate n-channel MOS transistors (hereinafter referred to as MOST). Numerals 1 and 2 designate transfer MOST's and numerals 3 and 4 driver MOST's. Numerals 5 and 6 designate data lines, numeral 7 a word line, and numerals 8 and 9 load resistances. Information stored in storing nodes 12 and 13 is held by supply current from a power supply line 10 (voltage: Vcc). Numeral 11 represents a ground line (voltage: Vss). Each of the above load resistances 8 and 9 can be formed by a polycrystalline silicon layer which is the same layer as that forming the gates of the MOST's 1-4. Alternatively, the load resistances can be a stacked polycrystalline silicon layer which is different from the gate material, wherein a portion of the polycrystalline silicon layer is left as an intrinsic semiconductor or made into a low impurity region to form the load resistance. Information is written into or read out from the above memory cell through the data lines 5 and 6 by changing the level of the word line 7 from the low-level voltage to the high-level voltage.
Owing to the recent processing in semiconductor technology of fine process, the static RAM tends to have higher density than previously possible. Accordingly, it is required to reduce the area occupied by the memory cell. The possibility of realizing a higher density RAM was studied on the basis of the above-mentioned prior art memory cell, and, as a result, the following defect became apparent.
α-particles emanating, for instance, from the impurities in the packaging material are irradiated to the surface of a semiconductor memory chip to reverse the information stored in the storing node of the memory cell, whereby random errors are generated. Regarding the so-called soft error, in this memory cell, the storing capacitances C 14 and 15, composed of gate capacitance, p-n junction capacitance and so on, decreases as the area of the memory cell decreases, and the amount of stored charge Q (=C·V, V: stored voltage) decreases. As a result, the frequency of generation of the soft error due to irradiation of the α-particles becomes higher than in former devices. Accordingly, to strengthen the resistance to soft error to the same extent as formerly, some means is needed for increasing the amount of stored charge to the same extent as former devices.
SUMMARY OF THE INVENTION
An object of the present invention is to overcome the above-mentioned defect of the prior art and provide a static memory cell occupying a small area, which can realize a high density static RAM.
A further object of the present invention is to provide a semiconductor memory device suitable for a high density memory which occupies a small area and has the same high reliability as conventional devices.
To achieve the above objects, the semiconductor memory device of the present invention is constructed by providing an electrode on an insulating layer which is located on the drain and/or the gate of the MOS transistors constituting the memory cell of a static memory device, thereby to increase the capacitance of the storing node of the memory cell. It is known that the above memory cell consists of, for instance, as described later, a circuit comprising load resistances and four MOST's, and in this case, it is advantageous to form the above-mentioned electrode, for increasing the capacitance, between the MOST's and the load resistance, namely to form the load resistance on the electrode with an insulating layer interposed between them. In addition, the power supply voltage or the ground voltage is applied to the electrode.
The basic concept of the present invention will now be explained using FIG. 2. FIG. 2 shows an example of the circuit diagram of the present invention. In the figure, numerals 16 and 17 designate the storing capacitances which are newly added to the storing nodes 12 and 13, respectively. The remaining numerals in FIG. 2 indicate the same portions as in FIG. 1. The characteristic feature of the present invention resides in that the increase of the storing capacitance is realized by the newly added capacitances which are different from the conventional stray capacitance. According to the present invention, a semiconductor memory device which strongly resists the soft error can be obtained as a result of the increase of the amount of stored charge due to the storing capacitances 16 and 17.
Even if the storing capacitances to be newly added are small, they are effective to that extent, and the effect for reducing soft errors is enhanced as the capacitances increase. Since the semiconductor memory device has the construction of an integrated circuit, the upper limits of the capacitances are thus automatically determined by the shape and size of each memory cell. The electrode for increasing the above capacitances may be constructed by an electrically conductive material which is used for integrated circuits, for instance, polycrystalline silicon. In addition, so long as insulation is maintained, it is advantageous that the above-mentioned insulating layer becomes thinner, because the capacitance becomes larger.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a circuit diagram showing the semiconductor memory device according to the prior art;
FIG. 2 is a circuit diagram showing the semiconductor memory device of an embodiment of the present invention;
FIGS. 3, 4 and 5 are sectional views showing the structures of the semiconductor memory devices in the first, second and third embodiments of the present invention, respectively; and
FIG. 6 is a layout pattern showing the structure of the semiconductor memory device in the fourth embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
EMBODIMENT 1
FIG. 3 is a sectional view showing the main structure of the semiconductor memory device of this embodiment. The circuit of this semiconductor memory device is shown in FIG. 2 as mentioned above. That is, this circuit includes the storing capacitances 16 and 17 which are newly added to the storing nodes 12 and 13 of a static semiconductor memory device comprising two driver MOST's 3 and 4 constituting a flip-flop, and two transfer MOST's 1 and 2 respectively connected to the drains of the two driver MOST's, wherein the gates and drains of the two driver MOST's are cross-connected to each other, with each drain being connected to one end of each load resistance and each source being grounded, and the other end of the load resistance is connected to a power supply, and the word line 7 and data lines 5 and 6 are connected to the transfer MOST's.
By referring to FIG. 3, the structure of the semiconductor memory device of this embodiment is explained below.
Insulating isolation layers 19, 20 and 21 are provided in a p-type substrate 18, together with an n-channel transfer MOST 34 having a drain and a source, made of n-type impurity layers 22 and 23, respectively, and gate 26, and an n-channel driver MOST 35 having a gate 27 (the source and drain thereof are not seen in this sectional view because they exist in the direction perpendicular to the surface of the paper so as to sandwich the gate). Then, the capacitances 16 and 17 shown in FIG. 2 are constructed on the MOST's 34 and 35 by sandwiching a 6000 Å-thick insulating material layer 29 (SiO 2 film or composite film of SiO 2 and Si 3 N 4 ) between the storing nodes (numerals 12 and 13 in FIG. 2, and one of them corresponding to numerals 23 and 27 in FIG. 3) and an electrode 30 composed of the second polycrystalline silicon layer. After forming thereon a 4000 Å-thick insulating material layer 32 composed of, for instance, SiO 2 , a load resistance 33 is formed by the third polycrystalline silicon layer. The power supply voltage or the ground voltage is applied to the electrode 30. In FIG. 3, numerals 24 and 25 designate gate insulating films, and numerals 28 and 31 designate insulating layers. In addition, FIG. 3 shows half of the circuit shown in FIG. 2, for instance, the structure corresponding to the portions which correspond to the transfer MOST 1, driver MOST 4, load resistance 8, storing node 12 and storing capacitance 16. The remaining half of the circuit of FIG. 2 is omitted from the drawing of FIG. 3 because it has the same structure. The same thing can be said with FIGS. 4 and 5 which are described later.
The semiconductor memory device of this embodiment is a 256 kilobit static-type one whose memory cell area is 100 μm 2 , and 60% or more of the area becomes the effective area for forming the storing capacitance. As a result, the storing capacitance is remarkably increased, and the occurrence of soft errors is remarkably decreased. Namely, while the storing capacitance of the semiconductor memory device of the prior art having the same size as this embodiment and having four MOST's was 10 fF (femto-farad), the storing capacitance of the semiconductor memory device of this embodiment became 15 fF. As a result, an increase of 5 fF was obtained. For this, the soft error rate of the semiconductor memory device of this embodiment decreases by three figures as compared with the conventional device. In other words, if the soft error rate of the above conventional semiconductor memory device is assumed to be 1000 FIT, a highly reliable semiconductor memory device having the soft error rate of 1 FIT or less can be obtained by the present invention.
In addition, in the structure that the load resistance is formed after the electrode for obtaining the new capacitance is formed, as in this embodiment, the polycrystalline silicon layer forming the load resistance becomes the upper layer. Therefore, the device of this embodiment has the other advantage that, since the heat-treatment is applied only once, the heat-treatment time of the polycrystalline silicon layer can be reduced, by which the deviation of the load resistance value depending on the heat-treatment time can be made small. Accordingly, the above structure is very effective.
EMBODIMENT 2
FIG. 4 is a sectional view showing the main structure of the semiconductor memory device of this embodiment. The numerals in this figure are same as those in FIG. 3. The characteristic feature of this embodiment resides in that the electrode 30 is fixed to the power supply voltage (Vcc). In this structure, the electrode of the power supply side of the load resistance 33 and the power supply side of the electrode 30 can be shared by each other. This is very effective because the wiring of the electrode 30 can be performed without increasing the area occupied by the memory cell.
Further, as in Embodiment 1, the semiconductor memory device of this embodiment also showed the effect of increasing the storing capacitance and remarkably reducing the soft error rate.
EMBODIMENT 3
FIG. 5 is a sectional view showing the main structure of the semiconductor memory device of this embodiment. The numerals other than 36 in this figure are same as those in FIG. 3. The characteristic feature of this embodiment resides in that the electrode 30 is fixed to the ground voltage (Vss). In this structure, the ground side terminal of the memory cell 36 and the ground side of the electrode 30 can be shared by each other. This is also very effective because the wiring of the electrode 30 can be performed without increasing the area occupied by the memory cell.
In addition, as in the above-mentioned Embodiments 1 and 2, the semiconductor memory device of this embodiment also showed the effect of increasing the storing capacitance and remarkably reducing the soft error rate.
EMBODIMENT 4
FIG. 6 shows the layout pattern of the semiconductor memory device of this embodiment. MOST's 109, 110, 111 and 112 are formed with n-type impurity diffusion layers 101 and 102 and the first polycrystalline silicon layers 103, 104 and 105, and the storing capacitances 16 and 17 of FIG. 2 are formed with the storing node (corresponding to numeral 12 or 13 of FIG. 2) and the electrode 106 composed of the second polycrystalline silicon layer. The capacitance represented by numeral 16 (17) of FIG. 2 can be formed on the n-type impurity diffusion layer represented by numeral 113 (115) and on the first polycrystalline silicon layer represented by numeral 114 (116). Not only the electrode 106 may be common to the whole memory cell, but also all of the area occupied by the storing node in the layout pattern can be used to form the capacitance to be newly added except the contact region for connecting the load resistance (formed with the third polycrystalline silicon layers 107 and 108) and the storing node. It is thus very effective. In addition, since the electrode 106 may be fixed to either Vcc or Vss, flexibility can be given to the memory cell design. Thus, it is further effective. The hatched portions in FIG. 6 represent the portions on which the storing capacitance can be formed.
As described above, according to the present invention, a static memory cell occupying a small area and having strong resistance to the α-ray can be provided, and it is greatly effective for realizing a high density RAM.
The present embodiments have been explained for the memory cell formed on a p-type substrate, but it is needless to say that the present invention can be applied to the memory cell formed in the p-type well in a n-type substrate.
If the types of the impurities and the well used in the above explanation of the present invention are reversed, the effect of the present invention is the same. Further, it is needless to say that, if the present invention is applied to a memory cell in which the transfer MOST's consist of p-channel MOST's and the driver MOST's consist of n-channel MOST's, the same effect can be obtained. | A semiconductor memory device is provided in which an electrode applied with the power supply voltage or the ground voltage is provided on an insulating layer over the drain and/or the gate of the MOS transistors constituting the memory cell of a static memory device, thereby to increasing the capacitance of the storing node of the memory cell. This semiconductor memory device significantly reduces the occurrence of soft errors. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a thread cutting apparatus for use with, in particular, a sewing machine which includes a stitch forming device and a work-sheet feeding device and which forms stitches on the work sheet by means of relative movements of the stitch forming device and the work-sheet feeding device.
2. Related Art Statement
There is known a thread cutting apparatus which is employed in a sewing machine and which includes a thread-cutting control cam fixed to a lower shaft of the sewing machine and a blade moving mechanism which cooperates with the control cam to move a blade to cut a sewing thread or threads. In the prior thread cutting apparatus, the control cam and the moving mechanism are disconnectably connectable to each other. The prior apparatus additionally includes an exclusive operable member or an exclusive drive device for connecting the blade moving device to the control cam via an exclusive connecting device or transmission mechanism. The exclusive drive device may be provided by a solenoid and a control circuit for the solenoid, and the exclusive transmission mechanism may be provided by a link mechanism. Those exclusive drive device and transmission mechanism are provided in addition to the other mechanisms of the sewing machine, such as a shuttle, shuttle drive device, bobbin-thread take-up, work-sheet feeding device, etc.
However, since the prior thread cutting apparatus needs the exclusive solenoid, solenoid control circuit, transmission mechanism, etc. for cutting the sewing threads, the employment of the cutting apparatus in the sewing machine results in increasing the size of the sewing machine, increasing the total number of parts used in the same, and increasing the production cost of the same. In addition, the employment of those exclusive mechanisms for the thread cutting function leads to lowering the degree of freedom of the designing of the other mechanisms of the sewing machine by limiting, e.g., the sizes, spaces, and/or movable ranges thereof or therefor.
Japanese Patent Application laid open for opposition under Publication No. 2(1990)-14779 discloses a thread cutting apparatus which utilizes a drive source provided primarily for feeding a work sheet, secondarily for connecting a blade moving device to a thread-cutting control cam. However, this apparatus also suffers from the disadvantage of a very complex construction.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a thread cutting apparatus which enjoys a simple construction, thereby contributing to improving the freedom of designing of, e.g., a sewing machine with which the thread cutting apparatus is used.
The above object has been achieved by the present invention. According to a first aspect of the present invention, there is provided a thread cutting apparatus comprising a pair of blades at least one of which is movable relative to the other blade to cut a thread, a movable-blade actuating device including a thread-cutting control cam which is rotatable about an axis line, and a cam follower which is movable to an operative position thereof where the cam follower follows the control cam to move the movable blade to cut the thread, and an inoperative position thereof where the cam follower does not follow the control cam, a biasing device which provides a biasing force to bias the cam follower toward the inoperative position, a first movable member which is operatively engaged with the cam follower and which is movable to a first position thereof, and a second position thereof to move the cam follower to the operative position against the biasing force of the biasing device, a second movable member which is movable between a third and a fourth position thereof and which engages, when being moved from the third position to the fourth position, the first movable member to move the first movable member to the second position, and a rotary member which is rotatable with the control cam and which holds the first movable member at the second position, against the biasing force of the biasing device, after the second movable member is moved from the fourth position to the third position, the rotary member permitting the first movable member to be moved to the first position, owing to the biasing force of the biasing device, after the control cam is rotated, the cam follower follows the rotation of the cam, and the movable blade is moved to cut the thread.
In the thread cutting apparatus in accordance with the first aspect of the invention, the thread-cutting control cam and the rotary member are rotatable with each other. When the control cam is rotated and the cam follower follows the rotation of the cam, the rotary member is also rotated while holding the first movable member at the second position, and the movable blade is moved to cut the thread. Thus, the present thread cutting apparatus enjoys a simple construction. The biasing device may indirectly apply the biasing force to the first movable member via the cam follower, or may otherwise apply directly the biasing force to the first movable member.
According to a preferred feature of the first aspect of the invention, the thread-cutting control cam and the rotary member are provided by a single rotatable member which is rotatable about the axis line. In this case, the thread cutting apparatus enjoys a very simple construction.
According to another feature of the first aspect of the invention, the thread-cutting control cam comprises a cylindrical cam having a cam groove formed in an outer circumferential surface thereof. In this case, the cam follower may forcedly be rotated about an axis line perpendicular to the axis line of the control cam. For example, in the case where the control cam is fixed to a lower shaft of a sewing machine, the cam is rotated with the lower shaft, i.e., rotated about a horizontal axis line. In the latter case, the cam follower may be rotated about a vertical axis line, in a plane parallel to a horizontal top surface of a sewing bed of the sewing machine. The thread can be cut with reliability by forcively rotating the cam follower.
According to another feature of the first aspect of the invention, the rotary member includes a cylindrical base portion whose center line coincides with the axis line, and an annular rib which projects concentrically from one end of the base portion and which has a recess extending in a circumferential direction of the annular rib, the rotary member holding the first movable member at the second position where a first portion of the first movable member is supported on an outer circumferential surface of the annular rib, the recess permitting the first movable member to be moved therethrough to the first position where the first portion of the first movable member is positioned inside the annular rib, owing to the biasing force of the biasing device. The employment of the rotary member having the annular rib and the recess contributes to reducing the production cost of the present apparatus.
According to another feature of the first aspect of the invention, the thread cutting apparatus is used with a sewing machine including an upper shaft, and a lower shaft for rotating a shuttle, and the thread-cutting control cam and the rotary member are fixed to the lower shaft of the sewing machine. In this case, the lower shaft primarily provided for driving the shuttle is secondarily used as means for supplying energy to cut the thread. Thus, the construction of the thread cutting apparatus is simplified.
According to another feature of the first aspect of the invention, the thread cutting apparatus is used with a sewing machine including a feeding member for feeding a work sheet, and the second movable member comprises the feeding member, the third position of the second movable member being in a normal range in which the feeding member is movable to feed the work sheet during a stitch-forming operation of the sewing machine, the fourth position of the second movable member being outside the normal range. Since the work-sheet feeding member is provided in the vicinity of the movable blade, the utilization of the feeding member as the second movable member contributes to reducing the size of the present apparatus.
According to another feature of the first aspect of the invention, the first movable member comprises a rotatable member which is rotatable about an axis line thereof to each of the first and second positions. Although the first movable member may be provided by a linearly movable member, a rotatable member can more easily be produced as the first movable member.
According to another feature of the first aspect of the invention, the rotatable member includes three arm portions which project radially from the axis line thereof and one of which is operatively engaged with the cam follower and the other two of which are engageable with the second movable member and the rotary member, respectively. In this case, the single rotatable member can operatively connect the cam follower to both the second movable member and the rotary member, thereby simplifying the construction of the thread cutting apparatus.
According to another feature of the first aspect of the invention, the thread cutting apparatus further comprises a support member which supports the cam follower such that the cam follower is movable along, and rotatable about, an axis line of the support member, and the cam follower is moved to the operative position along the axis line thereof and is rotated at the operative position about the axis line of the support member to move the movable blade to cut the thread. In this case, the construction of the thread cutting apparatus is simplified.
According to another feature of the first aspect of the invention, the thread cutting apparatus further comprises a support member which supports the cam follower such that the cam follower is movable along, and rotatable about, an axis line of the support member which is substantially perpendicular to the axis line of the thread-cutting control cam, wherein the cam follower is moved to the operative position along the axis line of the support member and is rotated at the operative position about the axis line to move the movable blade to cut the thread, and wherein the first movable member comprises a rotatable member which is rotatable, to each of the first and second positions, about an axis line thereof which is substantially perpendicular to the axis line of the support member. In this case, the thread cutting apparatus enjoys a simplified construction.
According to another feature of the first aspect of the invention, the cam follower includes a pair of engagement portions which are spaced apart from each other in a direction parallel to the axis line of the support member, and the rotatable member includes an engagement arm whose end portion is sandwiched between the pair of engagement portions of the cam follower such that the rotation of the rotatable member and the axial movement and rotation of the cam follower are permitted. In this case, the cam follower and the rotatable member that are rotatable about the respective axis lines substantially perpendicular to each other, are held in engagement with each other in a simple and stable fashion.
According to another feature of the first aspect of the invention, the movable blade comprises a reciprocating blade which reciprocates along a straight line.
According to another feature of the first aspect of the invention, the thread cutting apparatus further comprises a support member which supports the cam follower such that the cam follower is movable along, and rotatable about, an axis line of the support member which is substantially perpendicular to the axis line of the thread-cutting control cam, wherein the movable-blade actuating device comprises an intermediate lever which is rotatable about, and immovable along, an axis line thereof parallel to the axis line of the support member, and which is engaged with the cam follower and the movable blade, and wherein when the cam follower is rotated, the intermediate lever reciprocates the movable blade along the straight line. In this case, the movable-blade actuating device enjoys a simple construction.
According to another feature of the first aspect of the invention, the movable-blade actuating device comprises a spring member which provides a biasing force to hold the movable blade at an inoperative position thereof and which permits the movable blade to be moved thereagainst by the thread-cutting cam and the cam follower so as to cut the thread.
According to another feature of the first aspect of the invention, the thread cutting apparatus further comprises an input device which is operable to input an electric thread-cutting command, and a control device which is operable, in response to the thread-cutting command, for moving the second movable member from the third position to the fourth position.
According to another feature of the first aspect of the invention, the thread cutting apparatus is used with a sewing machine including a feeding member for feeding a work sheet and a feeding-pitch adjusting member whose inclination angle is changeable within a normal range for adjusting a work-sheet feeding pitch of the feeding member, and the thread-cutting apparatus further comprises a control device which inclines the adjusting member by an angle beyond the normal range so that the second movable member is moved from the third position to the fourth position and the thread is cut by the pair of blades.
According to another feature of the first aspect of the invention, the thread cutting apparatus is used with a sewing machine including a feeding member for feeding a work sheet and a feeding-pitch adjusting member whose inclination angle is changeable within a normal range for adjusting a work-sheet feeding pitch of the feeding member, and the thread-cutting apparatus further comprises an input device which is operable to input an electric thread-cutting command, and a control device which is operable, in response to the thread-cutting command, for inclining the adjusting member by an angle beyond the normal range so that the second movable member is moved from the third position to the fourth position.
According to a second aspect of the present invention, there is provided a thread cutting apparatus comprising a pair of blades at least one of which is movable relative to the other blade to cut a thread, a movable-blade actuating device including a thread-cutting control cam which is rotatable about a first axis line, and a cam follower which is movable to an operative position thereof where the cam follower follows the control cam to move the movable blade to cut the thread, and an inoperative position thereof where the cam follower does not follow the control cam, the cam follower being movable along, and rotatable about, a second axis line, the cam follower being moved to the operative position along the second axis line and rotated at the operative position about the second axis line to move the movable blade to cut the thread, a biasing device which provides a biasing force to bias the cam follower toward the inoperative position, a first movable member which is operatively engaged with the cam follower and which is movable to a first position thereof, and a second position thereof to move the cam follower to the operative position against the biasing force of the biasing device, a second movable member which is movable between a third and a fourth position thereof and which engages, when being moved from the third position to the fourth position, the first movable member to move the first movable member to the second position, and a holding device which holds the first movable member at the second position, against the biasing force of the biasing device, after the second movable member is moved from the fourth position to the third position, the holding device permitting the first movable member to be moved to the first position, owing to the biasing force of the biasing device, after the control cam is rotated, the cam follower follows the rotation of the cam, and the movable blade is moved to cut the thread.
In the thread cutting apparatus in accordance with the second aspect of the invention, the cam follower can be moved along, and rotated about, the second axis line, so that the cam follower can be moved to the operative position along the second axis line and rotated at the operative position about the second axis line to move the movable blade to cut the thread. Thus, the thread cutting apparatus enjoys a simple construction. The cam follower may be moved relative to a support member, such as a shaft member, which defines the second axis line, or otherwise may be moved with the support member along the second axis line. Similarly, the cam follower may be rotated about the support member defining the second axis line, or otherwise may be rotated with the support member about the second axis line.
According to a preferred feature of the second aspect of the invention, the thread cutting apparatus further comprises a support member which supports the cam follower such that the cam follower is movable along, and rotatable about, the second axis line which is substantially perpendicular to the first axis line of the thread-cutting control cam.
According to another feature of the second aspect of the invention, the movable-blade actuating device comprises an intermediate lever which is rotatable about, and immovable along, a third axis line parallel to the second axis line of the support member and which is engaged with the cam follower and the movable blade, and wherein when the cam follower is rotated, the intermediate lever moves the movable blade to cut the thread. In this case, the movable-blade actuating device enjoys a simplified construction.
According to another feature of the second aspect of the invention, one of the cam follower and the intermediate lever includes an engagement projection which projects substantially parallel to the second axis line and the other of the cam follower and the lever includes an engagement recess which is engaged with the engagement projection irrespective of which one of the operative and inoperative positions is taken by the cam follower, the rotation of the cam follower about the second axis line being transmitted to the intermediate lever via the engaged projection and recess. In this case, even if the cam follower may be moved between the operative and inoperative positions, the cam follower and the intermediate lever are easily held in engagement with each other.
According to a third aspect of the present invention, there is provided a thread cutting apparatus for use with a sewing machine including an operable member which is operable within a normal range to control an operation of the sewing machine, the apparatus comprising, a pair of blades at least one of which is movable relative to the other blade to cut a thread, a movable-blade actuating device including a thread-cutting control cam which is rotatable about an axis line, and a cam follower which is movable to an operative position thereof where the cam follower follows the control cam to move the movable blade to cut the thread, and an inoperative position thereof where the cam follower does not follow the control cam, and a connecting device which operatively connects the operable member with the cam follower such that when the operable member is operated to a special position outside the normal range, the cam follower is moved to the operative position.
In the thread cutting apparatus in accordance with the third aspect of the invention, when the operable member is operated to the special position outside or beyond the normal range, the cam follower is moved to the operative position, so that the movable blade is moved to cut the thread. The connecting device may comprise a known device such as a zero-max link mechanism.
According to a preferred feature of the third aspect of the invention, the thread cutting apparatus further comprises a biasing device which produces a biasing force to bias the cam follower toward the inoperative position, and a holding device which holds the cam follower at the operative position, against the biasing force of the biasing device, after the operable member is moved to a position within the normal range, the holding device permitting the cam follower to be moved to the inoperative position, owing to the biasing force of the biasing device, after the control cam is rotated, the cam follower follows the rotation of the cam, and the movable blade is moved to cut the thread. In this case, the holding device holds the cam follower at the operative position, against the biasing force of the biasing device, even after the operable member has been moved to a position within the normal range, and permits the cam follower to be moved to the inoperative position, owing to the biasing force of the biasing device, after the movable blade has been moved to cut the thread. Therefore, the present thread cutting apparatus enjoys a better operability than an apparatus wherein an operable member must be held at a special position outside a normal operation range throughout each thread cutting operation and must be returned to a position inside the normal range after the thread cutting operation.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and optional objects, features, and advantages of the present invention will better be understood by reading the following detailed description of the preferred embodiments of the invention when considered in conjunction with the accompanying drawings, in which:
FIG. 1 is a plan view of a thread cutting apparatus embodying the present invention, the apparatus being in a state in which a stitch forming operation is carried out on a sewing machine;
FIG. 2 is a side view of the apparatus of FIG. 1;
FIG. 3 is a bottom view of the apparatus of FIG. 1;
FIG. 4 is an inverted side view of the apparatus of FIG. 1, with a thread-cutting unit thereof being partially cut away;
FIG. 5 is a plan view corresponding to FIG. 1, showing the apparatus of FIG. 1 in a state in which a thread cutting operation is carried out on the sewing machine;
FIG. 6 is a side view corresponding to FIG. 2, showing the apparatus of FIG. 1 being in the state shown in FIG. 5;
FIG. 7 is an enlarged view of a portion of the apparatus of FIG. 1;
FIG. 8 is a perspective view of a stitch forming device and a work-sheet feeding device of the sewing machine with which the apparatus of FIG. 1 is used;
FIG. 9 is a view for illustrating the manner in which a work-sheet feed pitch adjuster 21 of the sewing machine is inclined;
FIG. 10 is an electric arrangement of the sewing machine;
FIG. 11 is a time chart representing a thread cutting operation carried out on the sewing machine;
FIG. 12 is an illustrative view of a work-sheet feed pitch selecting device of another thread cutting apparatus as a second embodiment of the present invention; and
FIG. 13 is an illustrative view of a work-sheet feed pitch selecting device of yet another thread cutting apparatus as a third embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIGS. 1 to 10, there will be described a thread cutting apparatus for use with a sewing machine. The thread cutting apparatus embodies the present invention.
As shown in FIGS. 1 to 4, the thread cutting apparatus includes a thread-cutting cylindrical control cam 2 fixed to an end of a lower shaft 1 of the sewing machine that extends in a right and a left direction of the sewing machine. The lower shaft 1 is rotated with an upper shaft 30 to which a sewing needle 42 is connected via a needle bar (not shown), as shown in FIG. 8. A thread cutting unit 3 is disposed above the control cam 2 with which the unit 3 cooperates to provide a movable-blade actuating device. The cutting unit 3 includes a thread-cutting frame 4 fixed to a main frame (not shown) of the sewing machine. A movable mess or blade 5 is supported by the frame 4 such that the movable blade 5 can be reciprocated by being guided in a straight groove 4a extending parallel to the lower shaft 1. A fixed blade 6 is fixed to the frame 4 and cooperates with the movable blade 5 to cut a needle thread conveyed by the needle 42 and a bobbin thread supplied from a bobbin (not shown) accommodated in a shuttle 28 (FIG. 8).
A first support shaft 7 which extends in a direction substantially perpendicular to the lower shaft 1 is fixed to a portion of the frame 4, and a first link 8 is supported by the first support shaft 7 such that the first link 8 is rotatable about the shaft 7 but is immovable in an axial direction of the shaft 7. The first link 8 provides a lever having a first elongate hole 8a which is rotatably engaged with a first pin 5a fixed to the movable blade 5 to reciprocate the blade 5 to cut the sewing threads. A second pin 5b fixed to the movable blade 5 is engaged with the guide groove 4a of the frame 4. A second support shaft 9 which extends parallel to the first support shaft 7 is fixed to another portion of the frame 4, and a second link 10 is supported by the second support shaft 9 such that the second link 10 is rotatable about the shaft 9 and is movable in an axial direction of the shaft 9. A torsion spring 11 produces a biasing force to bias, via the first link 8, the movable blade 5 toward a retracted or inoperative position thereof where the movable blade 5 cannot cooperate with the fixed blade 6 to cut the sewing threads. However, the movable blade 5 can be moved along the guide groove 4a to an advanced or operative position thereof where the blade 5 cooperates with the fixed blade 6 to cut the threads. A compression spring 12 produces a biasing force to bias the second link 10 toward an inoperative position thereof where an engagement pin 16 fixed to the second link 10 cannot engage a cam groove 2b of the control cam 2. However, the second link 10 can be moved, against the biasing force of the compression spring 12, relative to the second shaft 9 to an operative position thereof where the pin 16 can engage the cam groove 2b. The first link 8 has a second elongate hole 8b, and the second link 10 has an engagement projection 10a which is engaged with the elongate hole 8a irrespective of which position is being taken by the second link 10 relative to the second shaft 9.
A third support shaft 17 which extends parallel to the lower shaft 1 is fixed to the frame 4, and a thread-cutting switch member 18 is supported by the third shaft 17 such that the switch member 18 is rotatable about the shaft 17 and is immovable in an axial direction of the shaft 17. The switch member 18 has three arms which extend radially outwardly from an axis line of the third shaft 17.
The first arm of the switch member 18 extends in a frontward and downward direction of the sewing machine and has a circular boss 18a projecting parallel to the lower shaft 1. During a stitch forming operation of the sewing machine, the circular boss 18a is positioned radially inwardly of an annular rib 2a which projects concentrically from the control cam 2 in a direction parallel to the lower shaft 1. As shown in FIG. 4, the annular rib 2a has a recess 2c extending in a circumferential direction of the cam 2 over a length which enables the circular boss 18a to pass therethrough. The second arm 18b of the switch member 18 extends in an upward direction of the sewing machine and a top portion thereof is positioned in a route in which a projection 20a of a work-sheet feeder 20 to which a feed dog 19 is fixed is moved. The position of the second arm 18b is outside a forward-direction maximum feed amount or limit of a normal range within which the feeder projection 20a can be moved during the stitch forming operation of the sewing machine. Therefore, during the stitch forming operation of the sewing machine, the second arm 18b and the feeder projection 20a cannot engage each other even in the case where a forward-direction maximum feed pitch (indicated at "FORWARD MAX" in FIG. 9) may be selected by an operator through a feed-pitch input device 50 (FIG. 10).
The third arm of the switch member 18 extends in a rearward direction of the sewing machine and includes an end portion 18c having an upper and a lower curved (i.e., part-cylindrical) surface. The end portion 18c is sandwiched between an upper and a lower base portion 10b, 10b of the second link 10 via which the second link 10 can be rotated about the second shaft 9. The end portion 18c is engaged with the two base portions 10b, 10b such that the rotation of the switch member 18 about the third shaft 17 is permitted and the rotation and axial movement of the second link 10 about and along the second shaft 9 are permitted. The biasing force of the compression spring 12 is applied to the third arm 18c of the switch member 18 via the second link 10, so that the first arm or circular boss 18a is positioned radially inwardly of the rib 2a of the cam 2. However, when the second arm 18b of the switch member 18 is pushed rearward by the feeder projection 20a, the switch member 18 is rotated about the third shaft 17 and the third arm 18c is moved downward against the biasing force of the spring 12, so that the circular boss 18a is moved upward to a position outside the rib 2a and the engagement pin 16 fixed to the second link 10 is moved downward to the operative position where the pin 16 can engage the cam groove 2b of the cam 2. Thus, when the thread-cutting switch member 18 is rotated by the movement of the feeder projection 20a beyond the normal range, the thread-cutting unit 3 and the thread-cutting control cam 2, i.e., the movable-blade actuating device is placed in an operative state in which the actuating device can reciprocate the movable blade 5 between the retracted and advanced positions to cut the sewing threads. The switch member 18 (18a, 18b, 18c) is integrally formed of a synthetic resin.
As shown in FIG. 8, the feed dog 19 which feeds a work sheet (not shown) such as a fabric or cloth sheet relative to the sewing needle 42, is provided above the shuttle 28 which cooperates with the needle 42 to form stitches on the work sheet. The feed dog 19 is fixed to an upper surface of the work-sheet feeding member or feeder 20 provided around the shuttle 28, and is movable forward and backward, and upward and downward, together with the feeder 20. The shuttle 28 is rotated by the lower shaft 1 which is rotated in synchronism with the rotation of the upper shaft 30 which reciprocates the needle 42 upward and downward. The upper shaft 30 is rotated or driven by a main motor 32. The upward projection 20a is integrally formed with a portion of the feeder 20 provided on a left-hand side of the dog 19.
An end portion of the feeder 20 which is remote from the feed dog 19 is rotatably supported by upper end portions of a feed arm 34. A lower end portion of the feed arm 34 is rotatably supported via a feed-arm shaft 36 by the main frame of the sewing machine. One end of a feed link 38 is connected to an intermediate portion of the feed arm 34, and a guided member 40 is rotatably connected to the other end of the feed link 38. The guided member 40 is movably engaged with a guide groove 42 formed in a feed-pitch adjusting member or adjuster 21, and the adjuster 21 is fixed to an output shaft of a pulse motor 22 fixed to the main frame of the sewing machine. The feed link 38 is moved by a horizontal-feed cam 23 fixed to the lower shaft 1, so that the feeder 20 or feed dog 19 is moved in a horizontal direction, i.e., a forward and a backward direction thereof respectively corresponding to a rearward and a frontward direction of the sewing machine. In addition, the feeder 20 or dog 19 is moved upward and downward by a vertical-feed cam (not shown).
The feeder 20, feed link 38, guided member 40, feed-pitch adjuster 21, feed arm 34, feed-arm shaft 36, etc. cooperate with one another to provide a known zero-max link mechanism wherein the work-sheet feed pitch, i.e., amount of movement of the feed dog 19 in the horizontal direction can be adjusted by changing the angle of inclination of the feed-pitch adjuster 21. As shown in FIG. 9, when a center line of the adjuster 21, indicated at solid line, extends vertically, that is, the adjuster 21 is positioned at zero degree, the feed pitch is zero, that is, the work sheet is not fed forward or backward. As the angle of inclination of the center line of the adjuster 21 increases toward the front side of the sewing machine, the backward-direction feed pitch increases up to a maximum or limit ("BACKWARD MAX") indicated at two-dot chain line. On the other hand, as the angle of inclination of the center line of the adjuster 21 increases toward the rear side of the sewing machine, the forward-direction feed pitch increases up to a maximum or limit ("FORWARD MAX") indicated at one-dot chain line. When the feed dog 19 is moved in the forward direction thereof, the work sheet is fed in the rearward direction of the sewing machine; and when the feed dog 19 is moved in the backward direction thereof, the work sheet is fed in the frontward direction of the sewing machine.
For a stitch forming operation, a work-sheet feed pitch is selected or input by the operator through the feed-pitch input device 50 shown in FIG. 10. In response to an output signal from the input device 50, a central processing unit (CPU) 52 of a computer as a control device controls a drive circuit 54 to drive the pulse motor 22 and thereby rotate the feed-pitch adjuster 21 within the normal angular range between the forward-direction and backward-direction maximum feed pitches shown in FIG. 9.
When the stitch forming operation ends, the operator may operate a thread-cut-command input device 56 which generates, in response thereto, a command signal which is supplied to the CPU 52 which controls, in response thereto, the drive circuit 54 to drive the pulse motor 22 so that the center line of the adjuster 21 is inclined to a special angular position, indicated at broken line in FIG. 9, outside the normal angular range. This special position cannot be established by operating the feed-pitch input device 50. Thus, the feeder 20 or projection 20a is placed in a state in which the projection 20a can be moved beyond the normal movement range thereof, i.e., forward-direction maximum feed pitch thereof, in the rearward direction of the sewing machine. A needle-position sensor 58 is connected to the CPU 50. The sensor 58 detects a phase or position of the sewing needle 42 and supplies a detection signal indicative of the detected needle position to the CPU 50.
Next, there will be described the operation of the thread cutting apparatus constructed as described above, by reference to FIGS. 5, 6, and 7 and the time chart of FIG. 11.
When a stitch forming operation ends, the CPU 52 controls the main motor 32 to stop the sewing needle 42. Then, if a thread-cut command is input by the operator through the thread-cut-command input device 56, an electric command signal is supplied from the input device 56 to the CPU 52 which drives, at a time, t 1 , shown in FIG. 11, the pulse motor 22 to rotate the feed-pitch adjuster 21 to the special position, indicated at broken line in FIG. 9, beyond the normal range, when the lower shaft 1 is rotated by the main motor 32 to a predetermined phase detected by the needle-position sensor 58. Thus, the feeder 20 is fed in the forward direction thereof (i.e., in the rearward direction of the sewing machine) beyond the forward-direction maximum feed pitch, and the projection 20a pushes the second arm 18b of the thread-cutting switch member 18 in the rearward direction. Consequently the third arm 18c of the switch member 18 is moved downward with the second link 10 against the biasing force of the compression spring 12 and the engagement pin 16 fixed to the link 10 is moved downward to the operative position thereof where the pin 16 can engage the cam groove 2b of the thread-cutting control cam 2. In this way, the switch member 18 is rotated because of the special inclination of the feed-pitch adjuster 21.
In addition, since, at time t 1 , the recess 2c of the annular rib 2a of the cam 2 is positioned right above the circular boss 18a of the first arm of the thread-cutting switch member 18, the boss 18c is moved upward through the recess 2c to a position radially outside the rib 2a. When the lower shaft 1 is rotated from this state, a portion of the rib 2a is moved to a position below the boss 18a, at a time, t 2 , shown in FIG. 11. Subsequently, at a time, t 3 , the feeder 20 starts moving in the frontward direction of the sewing machine, because of the rotation of the horizontal-feed cam 23, so that the feeder projection 20a is moved away from the second arm 18b of the switch member 18. However, since the circular boss 18b is supported on the annular rib 2a of the cam 2, the switch member 18 keeps the second link 10 such that the pin 16 is held in the state in which the pin 16 can engage the cam groove 2b, as shown in FIGS. 5 to 7. While the feeder 20 is moved in the frontward direction, the adjuster 21 is automatically returned, at a time, t 4 , to the zero ("0") position.
As the lower shaft 1 is further rotated, the cam 2, pin 16, links 10, 8, etc. cooperate with one another to start, at a time, t 5 , reciprocating the movable blade 5 to cut the sewing threads. After the thread cutting operation ends at a time, t 6 , the recess 2c of the annular rib 2a is moved to a position below the circular boss 18a of the switch member 18, at a time, t 7 , so that the third arm 18c of the switch member 18 is moved upward because of the biasing or elastic force of the compression spring 12 and the circular boss 18a is moved downward through the recess 2c. The thread-cutting operation of the sewing machine ends at a time, t 8 . Thus, the thread-cutting switch member 18 is automatically switched from the thread-cutting position to the stitch-forming position. The movable blade 5 can be moved only while the switch member 18 is placed in the thread-cutting position.
As is apparent from the foregoing description, the thread-cutting switch member 18 is rotated by the feeder 20 (or projection 20a) as the work-sheet feeding device, so that the engagement pin 16 as a cam follower is moved to the operative position where the pin 16 can engage the cam groove 2b of the cam 2 and thereby move the movable blade 5 to cut the threads. Thus, the work-sheet feeding device 20, 20a is utilized as a drive source for moving the movable blade 5. In addition, the provision of the present thread cutting apparatus does not lower the degree of freedom of designing of the shuttle 28, the feed device 19, 20, etc. of the sewing machine. Since the present thread cutting apparatus does not need an exclusive drive source or control circuit, the employment of the apparatus contributes to reducing the size of the sewing machine and simplifying the construction of the same.
Since in the illustrated embodiment the projection 20a is provided on the conventional feeder 20 so that the projection 20a can engage and push the second arm 18b of the thread-cutting switch lever 18, the movable-blade actuating device 2, 3 is easily placed in the state in which the actuating device 2, 3 can actuate the movable blade 5 to cut the threads.
While the present invention has been described in its preferred embodiment, the present invention may otherwise be embodied.
For example, although in the illustrated embodiment the operator inputs a thread-cut command in the sewing machine through the electric input device 56, it is possible to employ a mechanical connecting device which operatively connects a manually operable member to the feed-pitch adjuster 21 such that when the operable member is operated to a special position beyond a normal range, the adjuster 21 is inclined to the special angular position indicated at broken line in FIG. 9. For example, FIG. 12 shows a feed-pitch selecting member 80 which is manually operable within a normal range from 0 to 4 degrees in each of the forward and backward directions of the feeder 20 and which is also operable to a special position, i.e., thread-cutting position beyond the normal range. Similarly, FIG. 13 shows a feed-pitch selecting knob 90 which is manually turnable within a normal angular range in each of the forward and backward directions of the feeder 20 and which is also turnable to a special angular position, i.e., thread-cutting position beyond the normal range. However, these modified arrangements are somewhat more complex than that of the arrangement shown in FIGS. 1 to 11. The mechanical connecting device which operatively connects the manually operable member 80, 90 to the feed-pitch adjuster 21 may be provided by a known zero-max link mechanism as described previously.
In addition, while in the illustrated embodiment the thread-cutting switch lever 18 is rotated by the work-sheet feeder 20 which feeds the work sheet in the frontward and rearward directions of the sewing machine, it is possible to replace the feeder 20 with a movable member which is movable in the right and left directions of the sewing machine.
Although in the illustrated embodiment the thread-cutting switch lever 18 is rotated by the work-sheet feeder 20, it is possible to replace the feeder 20 with an embroidery frame (not shown) which supports a work sheet and is movable in a two-dimensional plane relative to the sewing needle 42.
Moreover, although in the illustrated embodiment the sewing needle 42 vertically reciprocates at a fixed position in the horizontal plane, the principle of the present invention is applied to a sewing machine including a sewing needle which is movable in the horizontal plane. In the latter case, the switch lever 18 may be rotated by a stitch forming device which moves the sewing needle in the horizontal plane.
It is to be understood that the present invention may be embodied with other changes, improvements, and modifications that may occur to those skilled in the art without departing from the scope and spirit of the invention defined in the appended claims. | A thread cutting apparatus including a pair of blades one movable relative to the other to cut a thread, an actuating device including a cam rotatable about an axis line, and a cam follower which is movable to an operative position where the cam follower follows the cam to move the movable blade to cut the thread, and an inoperative position where the cam follower does not follow the cam, a biasing device which provides a biasing force to bias the cam follower toward the inoperative position, a first movable member which is operatively engaged with the cam follower and which is movable to a first position, and a second position to move the cam follower to the operative position against the biasing force of the biasing device, a second movable member which is movable between a third and a fourth position and which engages, when being moved from the third position to the fourth position, the first movable member to move the first movable member to the second position, and a rotary member which is rotatable with the cam and which holds the first movable member at the second position, against the biasing force of the biasing device, after the second movable member is moved from the fourth position to the third position, the rotary member permitting the first movable member to be moved to the first position, owing to the biasing force of the biasing device, after the movable blade is moved to cut the thread. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention.
This invention relates to insensitive, high performance explosives.
2. Description of the Prior Art.
The use of organic nitro compounds as explosives is well known. These compounds are self-oxidizing, i.e., the nitro groups provide the oxygen used in oxidation.
The highest detonation pressures achievable with the currently used organic nitro compounds are about 390 kbar. Further, the best performers (those from which detonation pressures approaching 390 Kbar are achievable) are highly sensitive. Thus, the use of the highest performing organic nitro compounds as explosives is risky and impractical. On the other hand, the lower performing explosives which possess acceptable stability are, without exception, underoxidized and generally exhibit low densities. The densities of the stable explosives are generally less than two grams per cm 3 . These two factors, i.e., the underoxidized nature of the stable organic nitro compounds and their low densities, severely limit their performance.
SUMMARY OF THE INVENTION
It has now been found that the performance of explosives based on commonly used organic nitro compounds can be increased to about 530 kbar by adding certain dense and stable but highly energetic inorganic oxidizers. Among the suitable oxidizers are: (NF 4 ) 2 TiF 6 , NF 4 BF 4 , Ti(ClO 4 ) 4 , (NF 4 ) 2 NiF 6 and other hereinafter named compounds.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Typical examples of performance increases achievable by the use of the inorganic oxidizers of this invention are illustrated in the following table.
TABLE______________________________________ Examples of TheoreticalPerformance Improvements DetonationSystem Weight % Pressure (kb)______________________________________Nitroquanidine (NQ) 100 255NQ + (NF.sub.4).sub.2 TiF.sub.6 43-57 349Triaminotrinitrobenzene (TATB) 100 280TATB + NF.sub.4 BF.sub.4 29-71 375TATB + (NF.sub.4).sub.2 TiF.sub.6 30-70 408HMX 100 382HMX + NF.sub.4 BF.sub.4 51-49 449HMX + Ti (C10.sub.4).sub.4 70-30 456HMX + (NF.sub.4).sub.2 TiF.sub.6 52-48 471HMX + (NF.sub.4).sub.2 NiF.sub.6 56-44 527______________________________________
The detonation pressures set forth in the foregoing table were calculated by means of the Kamlet correlation (J. Chem. Phys., 48, 23 (1968)), a method commonly used for the performance evaluation of explosives. The percentage of oxidizer used was chosen to obtain complete combustion of the organic nitro compound (to CO 2 , N 2 and HF in the case of HMX or NQ and to COF 2 , N 2 and HF in the case of TATB). As can be seen from the table, the performance of organic nitro explosives is significantly increased by the addition of dense energetic inorgaic oxidizers.
Laboratory tests have shown that the oxidizers and explosives are mutually compatible. For example, HMX and NF 4 BF 4 were found to be stable at 150° C. and drop weight tests of the HMX/NF 4 BF 4 mixtures showed only a moderate increase in sensitivity over that of pure HMX.
The examples given in the above table are illustrative only and are not intended to limit the scope of the invention. Other commonly used, underoxidized organic nitro compounds of suitable stability could be substituted for the explosives given as examples in the table. Similarly, other inorganic oxidizers could be substituted for those listed in the table.
The primary requirements for suitable oxidizers are high energy content, high density, high thermal stability and low reactivity with the organic nitro compounds. From this point of view, NF 4 + containing salts are ideally suited. The NF 4 +cation is isoelectronic with the extremely inert CF 4 molecule and, therefore, in spite of its high energy content, a relatively high activation energy is required to cause it to react with other compounds.
The concept of this invention is not limited to fluorine containing oxidizers. As can be seen from the example of Ti(ClO 4 ) 4 in the table, this fluorine-free oxidizer is equally useful. By analogy with the NF 4 + salts, Ti(ClO 4 ) 4 possesses all the necessary properties for use as an explosive ingredient.
Although oxygen containing oxidizers will be as effective as fluorine containing oxidizers in most explosives, fluorine containing oxidizers are advantageous in aluminized formulations. The addition of aluminum is known to increase the performance of an explosive, but the Al 2 O 3 combustion product formed in a fluorine-free system may not remain for a long enough time in the gas phase. AlF 3 , on the other hand, is formed as a combustion product when fluorine containing oxidizers are used. Since AlF 3 (sublimation point 1270° C.) is much more volatile than Al 2 O 3 (boiling point 2250° C.), the use of fluorine containing oxidizers offers a distinct advantage for aluminized systems in that efficiencies higher than those obtainable with oxygen containing oxidizers are achieved.
It has been stated above that the oxidizers listed in the table are illustrative only. Examples of other suitable oxidizers are NF 4 + salts such as: NF 4 Sb 3 F 16 , NF 4 SbF 6 , NF 4 HF 2 , NF 4 BiF 6 , NF 4 PF 6 , NF 4 GeF 5 , NF 4 AsF 6 , NF 4 Ti 2 F 9 , NF 4 Ti 3 F 13 , NF 4 Ti 6 F 25 , (NF 4 ) 2 SnF 6 and NF 4 SnF 5 and other metal perchlorates.
The salts disclosed herein are not soluble in organic nitro compounds so their use in liquid explosives in conjunction with liquid organic compounds is not possible. However, they may be used in plastic bonded (solid) explosives of the type wherein explosive ingredients are bound in a suitable binder (many of which are known in the art) and in slurries where oxidizer particles are suspended in liquid organic nitro compounds. | Insensitive, high performance explosives obtained by combining certain enetic, high density inorganic compounds with insensitive, underoxidized organic nitro compounds. | 2 |
TECHNICAL FIELD
[0001] The present invention relates generally to a computer-aided method for teaching and training, and a system to implement such method. In particular, the present invention relates to guided teaching in, for example, teaching a language to non-native speakers of the language, which combines the guidance of a teacher and the teaching materials presented in an interactive, audio-visual manner.
BACKGROUND
[0002] As the new generation is exposed to using computer as a communication means, instant messaging software is popular among students as a communication outside the classroom. Students are also used to the audio-visual stimulation common in most video games. Many automated teaching systems adopting a computer game format have been created in order to replace the conventional classroom method and to make learning a more attractive and enjoyable experience to students.
[0003] In teaching language, for example, a teaching approach is for the student to do exercises related to the words to be taught. The student may be asked to give a definition of a word, fill a word in a blank part of a passage, or to identify a picture related to a specific word, while a number of answers are given for the student to choose from. There are existing software packed with graphics and sound effects using such approach to enhance learning effectiveness that may be able to arouse the students' interest in doing the exercise. However, the value of those software can be doubtful if appropriate guidance in reaching the correct answer sensibly is not provided, as the student who may simply make wild guesses and be frustrated by repeatedly failed attempts to arrive at the right answer, thus losing motivation to participate as a whole.
[0004] Obviously, the main disadvantage of such automated teaching method is that it lacks the human touch and the guidance from a teacher, which are the crucial elements that these products have thus far failed to capture from the conventional teaching method. The guidance of a teacher serves to guide the student back on the right track to think sensibly when a wrong answer is selected by leading the student through a brainstorming process, using additional data or hint that can assist the student to reach the correct answer in a sensible manner but not by wild guessing that very often is merely the effect of reflexive sense. Such discussion creates a bond between teacher and student and forms a friendly, appealing and interactive learning atmosphere which is only found in conventional classroom approach.
[0005] There are drawbacks however in conventional classroom approach that has to be refined using modern technology. The major one perhaps is the pre-requisite for the teacher to be very proficient in all aspects of the subject matter. Due to the complexity of some subjects such as language, it very often takes exhaustive training to groom high caliber teachers who shall have a strong grasp of grammar as well as the intuition for application of the language. Hence, it makes sense to have a system that can equip the teacher with preloaded data and answer keys to support his teaching, with which the teacher is able to gradually pick up more knowledge about a particular subject matter as he uses the system to teach repeatedly along. That way, teacher can focus on playing the role as a facilitator to guide the students through an interactive learning process, and be released from the cumbersome task of digesting the details before giving the lesson.
[0006] Moreover, globalization has called for increased international communication. A few languages, such as English and Mandarin, are becoming more popularly used around the world, which in turn leads to an increase in the demand of language teachers to teach non-native speakers. A user-friendly teaching system is required to reduce the training period of the teachers. Undoubtedly, the value of a system with pre-loaded data is especially outstanding in situation where supply of experienced teachers or trainers is limited.
[0007] Another advantage of a preloaded database is that it can upkeep a curriculum systematically that can be then delivered in a method preset by the system, avoiding the subject matter and additional hint delivered by one teacher to deviate much from another. In addition, when a teacher departs or is absent, substitute teachers can readily assume his role using the same system loaded with teaching material to be delivered in manner already adapted by the students.
[0008] As it is rather time consuming to gather information and statistics on classroom experience for refining curriculum, a good system shall allow storing valuable information generated by teachers and students in the classroom for the purpose. In addition, flexibility for sharing the same among different teachers and students should be emphasized. The teacher himself may sometimes have much insight to offer in teaching a particular subject matter. The same situation applies to students too. In teaching vocabulary, for example, a student may have created a sentence to demonstrate the use of a word that is worth sharing with the students in other classes, on the other hand, may have misunderstood the usage of another word that can be applied as teaching material so that the other students can learn from sharing such mistake. One can imagine how many creative examples of vocabulary application and teaching ideas have gone down the drain due to the inability of educational systems to capture and share them amongst the teachers and students. In other words, an effective teaching system should not only restrict learning from the input of the teacher and the students in one class, but should also facilitate the sharing of such input in an larger scale, covering classes taking the same course within a school using the same LAN, or even other schools conducting classes using the same WAN.
[0009] There are difficulties though in sharing teaching content and method of teaching between classes that need to be addressed too—Due to also the effects of globalization and the impact of modern technologies, it is not uncommon nowadays for people of different cultural backgrounds and language abilities to learn under one roof or remotely apart. Therefore, there should be a system that can support cross cultural teaching and learning to allow students to learn together and progress at individual pace without affecting his peers too much.
[0010] Another essential feature needed of a system with preloaded curriculum is that it should be able to handle the large amount of input from different sources by identifying what should and should not be stored. There should be a resource effective component to ensure that the data so stored is of quality and that it is easily accessible to the users concerned.
[0011] No matter how well a teaching and learning process is designed and how experienced the teacher is in applying the process to teach, students may fail to perform the way they should in light of the many distractions facing them. Hence, a good system should be equipped with a control to appraise effectiveness and most importantly suggest remedial action accordingly.
[0012] To ensure teaching effectiveness, very often educators or trainers need to give extra support to the slower performers. There should be a system that allows and structures tutorial sessions to be carried out by a peer teacher or student taking the role of the original teacher in similar manner as the original lesson has been taught. Although the teacher may select manually the students he believes to be weaker in performance and those stronger ones to be the buddy teacher, it will spare the teacher from such cumbersome process if the system can also automatically identify student tutors, the participating students and most importantly, to structure the appropriate teaching contents to be used in the relevant extra tutorial session.
[0013] Last but not least, although in class face-to-face teaching is a preferred method of implementation, a good system shall acknowledge distant learning being a solution for educators and trainers in times of technical problems such as bad weather, war or wide spread epidemics etc. or where expertise about a particular subject matter cannot be made available simultaneously at different classrooms located apart. Therefore, the system should cater for different implementation methods, allowing at least one student and or one teacher/trainer leading a class of student(s)/trainees located remotely away from the more experienced teacher(s) to take part
[0014] The invention is a computer aided method and system that effectively apply information technologies to turn teaching and learning process into a fun-filled interactive logical guessing game, which can address the above educational problems by incorporating scientific education management methodologies into teaching and learning.
SUMMARY OF THE INVENTION
[0015] The object of the present invention is to provide a computer-aided method for guided teaching, wherein teaching materials of various styles and stimuli are used.
[0016] In accordance with the present invention, there is provided a computer aided method for guided teaching and learning, using vocabulary as an example of subject matter. There are at least two methods of implementation. Implementation Method (1) for at least one teacher and one student within the same LAN, using at least one teacher workstation, with at least one student workstation, using at least one central processing unit, as well as an optional network or delivery device to support multimedia transmission of classroom discussions if needed. Implementation Method (2) for at least one teacher and one student or group of students on the WAN, using at least one central processing unit, as well as an optional network or communication to support multimedia transmission of classroom discussions if needed. The computer aided method and system comprising the steps of
[0017] In Implementation Method (1):
(a) presenting a question that is the subject item to the student at a student display; (b) receiving answer from the teacher at the teacher workstation, wherein the answer is received by the teacher from the student or students in class; (c) sharing the answer submitted on at least one student display; (d) determining whether the answer is correct; (e) presenting feedback to the answer at all student displays or workstations; (f) receiving input from the teacher at the teacher workstation for the teacher to give further information related to the question on student display; (g) presenting information sequentially and structurally using at least one of a plurality of styles and stimuli corresponding to the input from the teacher or student on the student display;
[0025] In Implementation Method (2):
(a) presenting a question that is the subject item at a teacher or student display; (b) allowing the teacher(s) and student(s) located apart to communicate interactively using separate device(s); (c) receiving answer from a remote teacher using a workstation whereas the answer is received by the remote teacher from the student or students in class; or receiving answer submitted directly by a remote student using a workstation; (d) sharing the answer submitted by the remote teacher or student on other displays or workstations connected together on the same WAN; (e) determining by the system whether the answer is correct; (f) presenting feedback by the system instantly to the answer submitted at all remote displays or workstations; (g) receiving input from the teacher at the teacher workstation for the teacher to give further information related to the question on student display; (h) presenting information sequentially and structurally using at least one of a plurality of styles and stimuli corresponding to the input from the teacher or student on the student display;
[0034] The present invention provides significant advantages over the conventional teaching method, for example, the teacher may provide guidance to the student on the student display or on remote workstation connected to the teacher's workstation, using various styles and stimuli, such as text, sound, voice, audio, graphics, pictures, photographs, animation, comics or video, in a guided teaching approach. Such guidance is applicable in many teaching modes and is especially effective when the teacher uses multiple choice questions to interact with the students in the teaching process. The students will not be frustrated after selecting a wrong answer because the teacher, with the aid of the system, can guide the student to reach the correct answer afterwards.
[0035] In one embodiment of the present invention, after presenting the question to the student on the student display, the teacher may present additional information related to the question on the student display to guide the student to reach the right answer.
[0036] In another embodiment of the present invention, the teacher is provided, on his teacher display, with the necessary information for guiding the student(s) to learn, including the correct answer to the question he present to the student for teaching.
[0037] In another embodiment of the present invention, the additional information may be presented in a plurality of styles and stimuli, comprising: text, sound, voice, audio, graphics, pictures, photographs, animation, comics or video to arouse the interests of the student to learn.
[0038] In another embodiment of the present invention, the teacher may save and share teacher notes with other teachers on the same LAN or WAN.
[0039] In another embodiment of the present invention, the student may save and share notes with other workstations on the same LAN or WAN.
[0040] In another embodiment of the present invention, the teacher notes shared among teachers on the same LAN or WAN may be presented in a plurality of styles and stimuli, comprising: text, sound, voice, audio, graphics, pictures, photographs, animation, comics or video.
[0041] In another embodiment of the present invention, the student notes shared among teachers on the same LAN or WAN may be presented in a plurality of styles and stimuli, comprising: text, sound, voice, audio, graphics, pictures, photographs, animation, comics or video.
[0042] In another embodiment of the present invention, the system saves and shares notes submitted by teachers and students systematically.
[0043] In another embodiment of the present invention, the teacher is provided with a feature to retrieve flexibility the saved notes authorized to be shared.
[0044] In another embodiment of the present invention, a system is provided to ensure the teaching materials and hints delivered to the students by various teachers either located physically in the same class with the students or remotely away from the students are consistent.
[0045] In another embodiment of the present invention, the teacher may adjust the teaching materials pre-set in the system.
[0046] In another embodiment of the present invention, a system is provided to automatically formulate the level of difficulty of the questions and teaching mode applicable presented to the students according to the performance of the students.
[0047] In another embodiment of the present invention, the teacher is provided with a feature to dynamically re-formulate the level of difficulty of the questions and teaching mode at his discretion.
[0048] In another embodiment of the present invention, a system is provided to allow another person, for example, a replacement teacher or a student, to take up the role of the original teacher without much deviation from the original teaching style.
[0049] In another embodiment of the present invention, a system is provided to assign the appropriate students to conduct or to take extra tutorial session, whereby to appoint at least one students if needed who is qualified for taking the role of the teacher in the same manner as the original lesson has been conducted.
[0050] In another embodiment of the present invention, a system is provided to adaptively formulate the teaching content of the extra tutorial session based on the attendance record and performance of the students assigned to take the extra tutorial session.
[0051] In another embodiment of the present invention, a system is provided for the teacher to re-formulate the teaching content of the extra tutorial session based on the attendance record and performance of the students assigned to take the extra tutorial session.
[0052] In another embodiment of the present invention, the key information taken down by the system or provided by different teachers and students joining the same teaching process is recorded by the system for future review of the course materials.
[0053] In another embodiment of the present invention, the system provides extra means of communication to allow sharing of such interactive guided teaching and learning process with other remote venues simultaneously using a cascade remote network or other device(s) to support conference meeting between the teacher(s) and student(s).
[0054] In another embodiment of the present invention, the system identifies automatically the quality of the teacher and student notes and processes the notes to make it easily accessible to teachers and students.
BRIEF DESCRIPTION OF DRAWINGS
[0055] The above and other aspects, features, and advantages of the present invention will become more apparent upon consideration of the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawing figures, wherein:—
[0056] FIG. 1 is a flowchart which illustrates the log-in process in accordance with an embodiment of the present invention;
[0057] FIG. 2 is a flowchart which illustrates the retrieval of teaching materials in accordance with an embodiment of the present invention;
[0058] FIGS. 3 a - 3 c are a set of flowcharts which illustrates the process of the guided teaching and learning method in accordance with an embodiment of the present invention;
[0059] FIG. 4 a shows the screen capture on the teacher workstation in accordance with an embodiment of the present invention to illustrate teaching, controlling the display of data on student's display or workstations, capturing and sharing input from teachers and students, displaying more data or hints using different stimuli and extra language translation support, adjusting level of difficulty by the teachers dynamically.
[0060] FIGS. 4 b and 4 c show the screen capture on the student display in accordance with an embodiment of the present invention;
[0061] FIG. 4 d shows the screen capture in accordance with an embodiment of the present invention to illustrate how the teacher prepares in advance teaching notes and pre-selects from database materials shared by other teachers and students for supporting teaching. The materials shared may be presented in various styles and stimuli, such as text, sound, voice, audio, graphics, pictures, photographs, animation, comics or video;
[0062] FIG. 4 e show the screen capture on the teacher or student workstation in accordance with an embodiment of the present invention to illustrate the student workstation used in distant learning;
[0063] FIG. 5 a shows the screen capture on the teacher workstation in accordance with an embodiment of the present invention to illustrate teaching, controlling display of data on student's display or workstations, capturing and sharing input from teachers and students, displaying more data using different stimuli and extra language support, adjusting level of difficulty by the teachers dynamically;
[0064] FIG. 5 b shows the screen capture on the student display in accordance with an embodiment of the present invention;
[0065] FIG. 5 c shows the screen capture on the student display in accordance with an embodiment of the present invention;
[0066] FIG. 5 d shows the screen capture in accordance with an embodiment of the present invention to illustrate how the teacher prepares teaching notes and pre-selects from database the materials shared by other teachers and students for supporting teaching;
[0067] FIG. 5 e show the screen capture on the teacher or student workstation in accordance with an embodiment of the present invention to illustrate the teacher or student workstation used in distant learning;
[0068] FIG. 6 illustrates a network arrangement in accordance with an embodiment of the present invention;
[0069] FIG. 7 is a flowchart which illustrates an individual practice session in accordance with an embodiment of the present invention;
[0070] FIG. 8 shows the screen capture which illustrates the recording of the score of students or trainees in the individual practice session in accordance with an embodiment of the present invention;
[0071] FIG. 9 is a flowchart which illustrates the adaptive teaching in accordance with an embodiment of the present invention;
[0072] FIG. 10 is a Remote teaching network diagram illustrating the method of implementation of the guided teaching and learning method on LAN;
[0073] FIG. 11 is a user interface of video conference between at least one teacher and one student on LAN;
[0074] FIG. 12 is a cascade remote teaching network diagram illustrating the method of implementation of the guided teaching and learning method on WAN;
[0075] FIG. 13 is a user interface of video conference between at least one teacher and one student on WAN.
DETAILED DESCRIPTION OF THE INVENTION
Log-In
[0076] As illustrated in FIGS. 1 and 6 , a preferred embodiment of the present invention allows the teacher to log-in at a teacher workstation [ 10 ] to record the teacher's attendance for a guided teaching session. The teacher, as well as the remote teacher(s) in the case of distant learning, may also log-in the students who are present for the student attendance record. Once the teacher logs in, he is provided with the option to trigger additional communication devices, for example, video conference system, to support interactive teaching and learning. The teacher workstation [ 10 ] may, for example, be a notebook computer or a terminal, with a display device and a keyboard.
[0077] As illustrated in FIG. 2 , in step [ 300 ], the teacher inputs the information related to the guided teaching session, for example, the grade, the class, the subject, as well as the lesson that can retrieve the relevant teaching mode and the pre-loaded teaching materials. The teaching mode defines the type of question used in the teaching and learning e.g. English, to be presented to the students. Some examples of the teaching mode are:
[0000]
Teaching mode
Description of question type
LNI
Listen to the description and identify a related
picture, video, picture, or other subject matters
LNW
Look at an object and write
MPC
Multiple choice
FIE
Fill in the essay
LMC
Listen to Mandarin or another language and choose an
answer in English
FIB
Fill in the blank
TOF
True or false
LRW
Link the right word
RNW
Read and write
WIN
Arrange pictures, video or subject matters in a logical
manner based on hints given
QNA
Question and answer
DIP
Definition of idiomatic phrase
PNV
Passage and vocabulary
[0078] Various teaching modes are provided so that the same set of materials used in teaching a language can be applied in different teaching modes according to the level of students and the desired outcome.
A Preferred Embodiment Dip Mode
[0079] A preferred embodiment for teaching idiomatic English, also known as phrasal verbs in a guided teaching session, is used to illustrate the present invention. A phrasal verb contains a verb and a preposition, which carries a specific meaning only when the two parts are combined and used together.
[0080] Regardless of the subject matter and the teaching mode chosen, the guided teaching session may be divided into the following major steps:
[0081] 1. Show and ask;
[0082] 2. Show more and prompt;
[0083] 3. Show and challenge; and
[0084] 4. Show and instruct
1. Show and Ask
[0085] In a preferred embodiment, as illustrated in FIGS. 3 a , 4 a and 6 , in step [ 302 ], a question set [ 110 ] containing a set of question items and a number of answers [ 112 a ] for selection is displayed at the teacher workstation [ 10 ]. The question set [ 110 ] is a number of question items being sentences each containing a verb and a following blank for student to insert an appropriate preposition. The students are given a list of answers [ 112 a ] to select from. In step [ 304 ], the teacher selects a question item among the question set [ 110 ] to work on and to be presented on a student display [ 12 ]. By way of example, the question item [ 114 a ] is selected.
[0086] The student display [ 12 ] may, for example, be a projector and screen for displaying to the whole class of students, or an individual monitor for each student. FIG. 4 b shows the screen displaying the question item [ 114 b ] selected by the teacher and the answers [ 112 b ] available for selection.
[0087] In step [ 306 ], the teacher discusses and interacts with the students until he has obtained one answer from the students to be entered. In step [ 308 ], the teacher clicks on the answer [ 116 ] selected by the students on the teacher workstation [ 10 ].
[0088] The answer [ 116 ] selected by the student will be shown on the student display [ 12 ]. In this preferred embodiment, a line is connected from the relevant verb to the selected preposition [ 116 ] to show the students the selected answer.
[0089] In step [ 310 ], a central processing unit [ 14 ] performs the comparison of the selected answer [ 116 ] with the correct answer. A feedback [ 118 ] is displayed on the student display [ 12 ]. The feedback [ 118 ] may be in the form of text, graphics or animation combined with sound effect, for indicating whether the selected answer [ 116 ] is correct or not.
[0090] When the guided teaching and learning process is conducted remotely, the host teacher can use a screen similar to teacher screen [ FIG. 4 a ] and [ FIG. 5 a ] to allow the remote teacher using button [ 114 a ] on FIG. 4 a or [ 204 ] on FIG. 5 a to input answer to the question present on the all the student displays, whereas the answer is collected by the teacher from his student(s). Meanwhile, the optional communication in the form of, for example, video conference serves to support interactive discussions.
2. Show More and Prompt
[0091] As illustrated in FIGS. 3 b , 4 a and 4 b , in step [ 312 ], if the selected answer [ 116 ] is wrong, the teacher may explain why the answer is wrong to the students by giving further information [ 120 ] related to the question [ 114 b ]. The information [ 120 ] is provided to guide the students to have a second attempt to get to the correct answer, which can be in the form of various styles and stimuli, such as text, sound, voice, audio, graphics, pictures, photographs, comics, video, or a combination of the above, to make the teaching process more appealing to the students.
[0092] By way of example, the information [ 120 ] is the definitions of the phrasal verbs given as the answers [ 112 b ] in text form. The teacher may select the phrasal verb of which the definition is to be shown from box [ 136 ] at the teacher workstation [ 10 ].
[0093] The information [ 120 ] is shown in box [ 138 ] on the teacher workstation [ 10 ]. The teacher may click Show button [ 140 ] to display the information [ 120 ] at the student display [ 12 ]. By way of example, the information [ 120 ] may also be provided in an audio form, that is, by executing an audio file containing the syllabus of the definition.
[0094] Such audio file may also contain a version in the native language of the student to enable the student to understand the information [ 120 ] more easily. The teacher may present the definitions of some or all the phrasal verbs in the answers [ 112 a ] one by one by clicking to select on [ 136 ]. After learning the definitions of the phrasal verbs, the students can easily select the right answer. The provision of the information [ 120 ] allows the students to make an educated selection rather than a wild guess.
[0095] As illustrated in FIG. 4 c , in step [ 314 ], the teacher leads a brainstorming discussion with the students to obtain an answer [ 122 ] from the students and inputs the answer at the teacher workstation [ 10 ]. The student display [ 12 ] shows the answer [ 122 ] and the feedback [ 124 ]. The teacher may choose to present the correct answer [ 126 ] as shown in step [ 316 ] or to repeat step [ 312 ] to give further information [ 120 ] to the students.
3. Show and Challenge
[0096] As illustrated in FIGS. 3 c , 4 a and 4 c , after displaying the correct answer [ 126 ], in step [ 318 ], the teacher may review his or other teachers' teaching notes [ 128 ] with respect to the question set [ 110 ], stored in the central processing unit [ 14 ] by selecting a level indicator [ 133 ] using pull down list [ 130 ]. The teaching notes [ 128 ] may be examples created by the teacher (see Review before class below) or used by other teachers to illustrate the correct answer [ 126 ]. The teaching notes [ 128 ] are grouped with respect to each specific question set and are automatically assigned a level indicator [ 133 ] on the level of difficulty according to the class for which the teacher has saved the teaching notes [ 128 ] for. By clicking the “Display” button [ 141 ], the teaching notes [ 128 ] stored in the system may be shown at the student display [ 12 ].
[0097] The teacher may also create his own teaching notes [ 128 ] in class in box [ 129 ] and show the teaching notes [ 128 ] at the student display [ 12 ] by clicking the Show button [ 132 ]. The teaching notes [ 128 ] will be saved for future reference. The teacher may save the teaching notes [ 128 ] without showing on the student display [ 12 ] by clicking the Save button [ 134 ]. If the teacher wants to make the teaching notes [ 128 ] available for other teachers, he may click the Share button [ 137 ] to authorize the sharing.
[0098] In step [ 320 ], the teacher guides the students to create their own sentences using the phrasal verb taught in the question [ 114 a ]. The teacher may enter the sentences [ 144 ] created by the students as reference notes in box [ 146 ] at the teacher workstation [ 10 ].
[0099] In step [ 322 ], the teacher may discuss with the students about the created sentence [ 144 ] and give his comments. If the created sentence [ 144 ] is a good example of the use of the phrasal verb, the teacher may save the sentence for future use by clicking the button [ 148 ]. If the created sentence [ 144 ] seems to be a common error made by many students, the teacher may save the sentence for future teaching purpose. If the teacher wants to make the sentences [ 144 ] available for other teachers, he may click the Share button [ 151 ] to authorize the sharing too.
4. Show and Instruct
[0100] The teacher may proceed to the next question by repeating from step [ 304 ]. In the course of teaching, the teacher may provide instructions to the students on homework assignments. In step [ 324 ], the teacher may enter the instructions [ 152 ] in box [ 154 ] at the teacher workstation [ 10 ] and click Show button to show the instructions [ 152 ] on the student display [ 12 ].
Review Before Class
[0101] As shown in FIG. 4 d , the teacher may preview the teaching materials, for example the question set [ 110 ] and the answers [ 112 ] for selection before conducting the teaching session. The teacher can therefore become acquainted with the teaching materials before class.
[0102] The teacher may also create some examples of sentences or other stimuli to illustrate the correct answer. Such examples or stimuli may be saved as teaching notes [ 128 ] in box [ 129 ] by clicking Save button [ 134 ] for the teacher's own retrieval or by clicking Share button [ 135 ] for sharing with other teachers. The teaching notes [ 128 ] are saved with respect to each question set and are assigned a level indicator [ 133 ] according to the level of the class the teaching notes [ 128 ] has been created for. The teacher may also review the teaching notes [ 128 ] of other teachers by selecting the level indicator [ 133 ] at box [ 130 ]. The teacher may pre-select the teaching notes [ 128 ] or stimuli of the teachers to be shown in the class by checking the box [ 131 ]. The pre-selected teaching notes or stimuli may be recalled in class by clicking Display button [ 141 ] as shown in FIG. 4 a.
[0103] In order to facilitate the teacher in shuffling and viewing the saved teaching notes or stimuli of other teachers', the central processing unit [ 14 ] may keep track of the number of times the teaching notes or stimuli have been selected to show to the students, and automatically delete the teaching notes below a predetermined selection rate in a period of time.
[0104] The teacher may also save some instructions [ 152 ] to be presented in class to students by inputting in box [ 154 ] and clicking Save button [ 142 ]. He may also share the instructions with other teachers by clicking Share button [ 169 ].
Another Embodiment
FIB Mode
[0105] In addition to the above embodiment for teaching phrasal verbs, the present invention is also applicable in other teaching mode. In another preferred embodiment for teaching vocabulary, the present invention is used in providing fill-in-the-blank questions using the FIB mode. The students are given a selection of words, which usually carry clear meanings by themselves. The teacher is allowed to provide additional hint or information to the students for reaching the correct answer.
[0106] As illustrated in FIGS. 5 a and 5 b , the teacher may click button “Show/Hide”[ 202 ] to present the question at a box [ 204 ] on the student display [ 12 ]. The teacher may also click button “Play”[ 206 ] to play a pre-recorded audio form of the question. A list of answers containing one correct answer is provided in box [ 208 ] on the student display [ 12 ]. The teacher may choose to hide the list of answers by clicking button [ 268 ] to create bigger challenge. The teacher may enter an answer in the blank in [ 204 ], which is collected from the students. A box [ 214 ] will show whether the answer entered is correct. If the answer is wrong, the teacher may further click the “Show/Hide” button [ 216 ] to show the additional information [ 218 ] on the student display [ 12 ] in box [ 220 ] which will assist the students in reaching the correct answer. By way of example, the information may be the definition of a word in box [ 208 ] or other stimuli related that can guide the students to think and choose sensibly. The teacher is allowed to modify the information in box [ 218 ] generated in the teacher workstation [ 10 ] if appropriate. The “Play” button [ 206 ] is disabled before the teacher enters the answer collected from the student. Should the teacher choose to disclose the correct answer to the students who have failed in several attempts, he can then click the button “Play and Show”[ 212 ] to display the answer [ 210 ] on the student display [ 12 ], he can also trigger extra material or text in other language [ 297 ] to display on [ 298 ] so as to make the students understand the meaning of a word more easily.
[0107] In FIG. 5 d . The teacher may review the teaching notes and stimuli of other teachers or to input his own teaching notes or stimuli in box [ 221 a ] before class. The teacher may enter his teaching notes or stimuli to be shown on the student display [ 12 ] by clicking the Save button [ 260 ]. The teacher may authorize the sharing of his teaching notes or stimuli with other teachers by clicking the Share button [ 262 ]. Further, a box [ 222 ] is provided for displaying and selecting the examples provided by other students and a box [ 224 ] is provided for entering the instructions for the students, for example, to do homework assignment that the teacher can also share with other teachers by clicking Share button [ 333 ].
Multi-Lingual Display
[0108] The teacher may select the language of the student display [ 12 ] according to the need of the students stored in the student's profile by selecting a language in box [ 219 ] on FIG. 5 a . By way of example, Chinese is used as the language of the student display [ 12 ], which also means that the student concerned would like to use Chinese as a plurality of extra languages to relate the subject matter easily, so that it is easier for him to understand the meaning of it.
[0109] There may be a mix of students from different countries in the class. Each student may prefer to have the student display [ 12 ] in his own language. In another preferred embodiment as shown in FIG. 5 e , Distant Learning Screen, each teacher in a remote class or student learning from home, is provided with his own student display [ 12 ] including an input device, for example a workstation. The teacher or student may reset the selected language using pull down list [ 225 ] on his workstation in case he wants to choose to learn a second language as he learns English along.
[0110] Details regarding students taking part in the guided teaching and learning will be stored in the system using a user profile which includes the extra language translation the relevant student will like to use as extra material [ 600 ] on FIG. 5 e used to help the student to learn more easily. The student can re-select his choice of language on his student display using pull down list [ 500 ] on 5 e.
Editing Materials
[0111] In this preferred embodiment, the teacher may easily edit the teaching materials, such as the question, the supplemental information and even the teaching notes or stimuli before class. As illustrated in FIG. 2 , in step [ 301 ], the teacher may retrieve the teaching materials for editing. The teacher may edit the questions or prepare his own teaching notes on a page as illustrated in FIG. 5 d . The teacher may edit the question in box [ 250 ] and click button “Edit base note” [ 252 ] to save the amendment. The teacher may also edit the supplemental information in box [ 254 ] and click button “Edit base note” [ 256 ] to save the amendment. The teacher may prepare the teaching notes or stimuli in box [ 258 ] and save the same by clicking Save button [ 260 ]. The teacher may further authorize the sharing of his teaching notes or stimuli with other teachers by clicking the Share button [ 262 ]. He may choose the level of difficulty of the teaching notes by clicking the level button [ 293 ] on 5 d and [ 133 ] on 4 d to make it easier for him to get to the type of teacher notes or stimuli most suitable for his own students.
Networking
[0112] As illustrated in FIG. 6 , the teacher workstation [ 10 ] and the student displays [ 12 ] are connected to the central processing unit [ 14 ], which may be, for example, a personal computer or a sever of the school. The server of the school may be connected to other computers [ 16 ], for example, in a student computer laboratory, or in the teacher office. The teachers and the students may also use their own computers [ 18 ] at home to access the central processing unit [ 14 ] via the Internet. There are two ways of implementation, Method (1) and Method (2). The central processing unit [ 14 ] of a school may be connected with the central processing unit [ 14 ] of another school to share the teaching materials. A global server [ 20 ] may contain the most updated software patch and teaching materials. The central processing units [ 14 ] may be connected to the global server [ 20 ] for regular downloading of the updated software patch and teaching materials.
Method (1)—Computer Aided Method for Teaching and Learning in Class on LAN (RTN)
[0113] Each student either has a workstation, or shares a common display with the class using a projector. The teacher teaches using the same guided teaching method. The teacher screen will be similar to, for example, FIGS. 4 a and 5 a . The student screen will be similar to, for example, FIGS. 4 b and 4 c as well as 5 b and 5 c . The student(s) also has an optional conference device ( FIG. 10 ) showing the teacher and all the participating students.
Method (2)—Computer Aided Method for Teaching and Learning in Class on WAN Using the Concept of Cascade Remote Teaching Network (CRTN)
[0114] Each Remote Teaching Network can support up to as many students as physically feasible in a remote classroom or training venue. In the event that there are more students than the venue can accommodate, new RTN groups can be created.
[0115] These new RTN groups can be cascaded to the main RTN network in a pyramid structure ( FIG. 11 ). The head teacher interacts with the RTN group teachers or student learning individually from home via the Video Conference Monitor. Each RTN group teacher interacts with his/her group of students similar to RTN in Method (1). The CRTN group teachers act as relays of the head teacher as well as other guest teachers [ 430 ] in FIG. 13 to present the teaching materials to the students in his own locale.
[0116] While the communication network is based on Internet, the connectivity for each student to the network may include DSL, cable modem, T1, satellite, wireless or whatever means available at the geographic locale of the student.
Video Conference Monitor
[0117] The key to a successful remote learning experience is the additional communication device—All the remote participating venues are equipped with communication device(s), for example, an extra computer (Video Conference Monitor) connecting to the internet. Upon a successful login to the system, the VCM automatically broadcast communication signals between the head teacher, guest teachers and all the participating venues. [ FIGS. 10 , 11 , 12 , and 13 ] joining the guided teaching and learning process.
Individual Practice Session
[0118] In addition to classroom teaching, the students may be requested to do homework assignment by taking individual practice session so as to enhance teaching and learning effect. In an individual practice sessions, by way of example as illustrated in FIG. 7 , each student is given multiple choice questions related to the teaching materials. The students may access the questions in a computer laboratory in school or at home via the Internet.
[0119] As illustrated in FIG. 8 , the scores of the students are recorded by the central processing unit [ 14 ] in FIG. 6 . By way of example, the student receives 1 score for each correct answer. The average score of all the students in the class therefore serves as an indicator on how familiar the class is with the teaching materials.
Adaptive Teaching
[0120] In a preferred embodiment as illustrated in FIG. 9 , in step [ 400 ], the central processor unit [ 14 ] records the scores of the students in attending individual practice sessions. The central processor unit [ 14 ] then suggests the level of difficulty to be adopted for the guided teaching session, the individual practice session and the tutorial session (which will be further described below) in step [ 402 ], according to a pre-determined table matching the average score to the level of difficulty. The teacher may re-adjust the level of difficulty using [ 273 ] as shown in FIG. 4 a and [ 230 ] as shown in FIG. 5 a.
[0121] By way of example, in providing fill-in-the-blank questions as illustrated in FIG. 5 b , the level of difficulty in providing fill-in-the-blank questions in a guided teaching session may be formulated by increasing or reducing the number of answers provided in box [ 208 ]. The more answers available to the students for selection, the more words the students need to know of the meaning before they can get at the right answer. As such, the level of difficulty increases with the number of answers for selection. The system can automatically generate the number of answers for selection according to the average score of the students in the individual practice session. The teacher may further adjust the number of answers if necessary according to the response of the students in class by using the pull down list [ 230 ] and [ 273 ].
Tutorial Session
[0122] Some students may be required to take extra tutorial session to be conducted by the more advanced student in the class. The advanced student may take the role of the teacher and host a guided teaching session for his classmates using the present invention. The students who need to take the extra tutorial session may be those who skip the class or those who score low in the individual practice session. In another preferred embodiment, the central processing unit [ 14 ] may assign the students to conduct or to take the extra tutorial session according to the attendance record of the students and their score recorded in the individual practice session. The teacher may preset a practice score and an attendance level to be the benchmark for a student to be qualified to be the teacher in the tutorial session or to be required to take the tutorial session. The central processing unit [ 14 ] may match the score of the students in the individual practice session and the attendance record to the benchmark score and attendance level to suggest to the teacher the students who may qualify as a teacher in the tutorial session or who may be required to take the tutorial session. The teacher may also assign students to the tutorial session according to his own observation. In addition, the system can automatically structure the appropriate teaching content based on the participating students' scores and behavior.
Saving Key Data
[0123] The central processing unit [ 14 ] will save the key data in the course of the guided teaching session, such as, the time required for the students to correctly answer a question, the number of times the teacher gives additional information on the student display for the students to select the correct answer and the number of wrong answers made by the students before reaching the correct answer. Such data may be used to review the course and to design better teaching materials, such as the questions, answers and additional information, to make teaching more effective.
Database Structure
[0124] The following databases are used as part of the method and system of the present invention.
[0000]
TABLE 1
Login Table
Name
Description
LogInID
Unique ID for login
UserName
User Name for login
Password
Password
UserType
Type of users (Teacher/Admin/Students . . . etc)
[0125] Table 1 holds the information for login. When a user login as illustrated in FIG. 1 , he will select the user type and input his username and password. The system will then obtain the login ID from the Login Table and check whether the user is authorized to login. If the login is successful, the system will load the corresponding screen according to the user type. The system will at the same time retrieve the component for video conferencing wherever necessary to support remote teaching and learning interactively.
[0000]
TABLE 2
Lessons Table
Name
Description
LessonID
Unique ID for lesson
ModeID
Unique ID for teaching mode
ClassID
Unique ID for class
Level Of Difficulty
Level of difficulty
[0126] Each lesson contains the teaching materials of the guided teaching system or the tutorial session, for example, the questions, the answers for selection, the additional information in various styles and stimuli, such as text, sound, voice, audio, graphics, pictures, photographs, animation, comics, or video. Table 2 holds a list of the Lesson ID.
[0127] After the teacher has input the required information and the lesson number in FIG. 2 , the system will select the relevant Lesson ID from the Lessons Table and load the corresponding teaching materials to the teacher workstation [ 10 ] and the student display [ 12 ] according to the level of difficulty & the teaching mode applicable, which are determined by the system automatically through analysis of student performance and learning behavior.
[0000]
TABLE 3
Mode Table
Name
Description
ModeID
Unique ID for teaching mode
Name
Name of teaching mode
Description
Description of teaching mode
[0128] Table 3 stores a list of the teaching mode. This table relates the teaching mode such as FIB, MPC, TOF and LRW and the description of the teaching mode to the Mode ID.
[0000]
TABLE 4
LessonItemID Table
Name
Description
LessonItemID
Unique ID for lesson Item
LessonID
Unique ID for lesson
[0129] Each Lesson Item contains the teaching materials of each question. Table 4 contains the Lesson Item ID and the Lesson ID. After selecting a Lesson by the teacher, the system will select the relevant Lesson Item ID from the LessonItemID Table and load the corresponding teaching materials to the teacher workstation [ 10 ] and the student display [ 12 ] according to the Lesson Item ID.
[0000]
TABLE 5
Phrase Table
Name
Description
Phrase ID
Unique ID for the phrase
Phrase
The question phrase
Audio
Audio file of the phrase
Definition
Definition of the phrase
DefinitionAudio
Audio file of the definition of the phrase
Example
Example of the phrase
ExampleAudio
Audio file of the example of the phrase
[0130] Table 5 contains phrases to be listed in box [ 112 A] on teacher workstation [ 10 ] and box [ 112 B] on student display [ 12 ] as well as examples of application [ 110 ] reflected on teacher workstation [ 10 ] which are to be displayed one by one [ 114 B] on the student display [ 12 ]. Each example of application can be combined with the relevant idiomatic phrase, which is the lesson item to be taught, from [ 112 ] on student display [ 12 ] to form a meaningful statement [ 126 ]. There is also a list of definitions to illustrate the meaning of the idiomatic phrases. Each phrase is loaded according to the phrase ID.
[0000]
TABLE 6
Vocabulary Table
Name
Description
VocabID
Unique ID for vocabulary
Vocab
Vocabulary
Definition
Definition of vocabulary
DefinitionAudio
Definition of vocabulary in audio format
Example
Example of the application of the vocabulary
ExampleAudio
Audio file of the example of the application
Answer
Answer of the example
Extra Language Translation
Meaning of the vocabulary in another
language
[0131] Table 6 contains the vocabulary, which may be the answers for selection in a question. The vocabulary is to be combined with the definition of vocabulary, extra language translations and the data from other tables such as the digital file etc. to form a complete question set. The audio recording of the pronunciation of the vocabulary, its example of the application, audio of the example of the application, and the answer of the example and extra language translation are also included in this table.
[0000]
TABLE 7
Digital File Table
Name
Description
DigitalFileID
Unique ID for digital file
Type
Type of the digital file
FilePath
Retrieval path of the digital file
Description
Description related to the digital file
[0132] Table 7 contains the ID for identifying the digital file related to each question. The digital file combines the data from other tables, such as the Phrase and the vocabulary, which may be the answers for selection, to form a complete question. This table also contains the type, the retrieval path and the description of the digital file.
[0000]
TABLE 8
Classes Table
Name
Description
ClassID
Unique ID for class
SubjectID
Unique ID for subject
ClassName
Name of class
Term
Term number
SchoolYear
School Year
[0133] Table 8 contains the information of each class. The system may retrieve the name of the class, subject to be taught, the term, the school year and other information of each class by the Class ID.
[0000]
TABLE 9
Student Table
Name
Description
StudentID
Unique ID for student
ClassName
Name of class
PersonalID
Personal ID for student
FirstName
First name of student
MiddleName
Middle name of student
LastName
Last name of student
ExtraLanguage
The type of extra language preferred
[0134] Table 9 contains the information of the students. The system may retrieve the information of the student, such as, the name of class, the student personal ID number, the first name, middle name and last name and the preferred extra language of the student by the Student ID. The additional language that used in translating the main object of learning e.g. vocabulary and phrasal verb, of the student display for selection may be set according to the nationality or personal profile of the student.
[0000]
TABLE 10
Student Test Summary Log Table for the Individual Practice Session
Name
Description
SummaryLogID
Unique ID for the Student Test Summary Log
StudentID
Unique ID for student
Score
Score of the Test
Remarks
Remark for the Test Summary Log
Correct
Number of correctly answered questions in a test
Wrong
Number of wrongly answered questions in a test
[0135] Table 10 contains the students' test results in the Individual Practice Sessions. The table contains the score, the number of correctly and wrongly answered questions, and the remarks of the test. The score will be referred to in nominating the level of difficulty of questions for adaptive teaching, and in selecting the students to participate in the Tutorial Session. The teacher uses the data in combination of his in-class experience to dynamically re-adjust the level of difficulty of questions. The test results may be retrieved by the Student ID.
[0000]
TABLE 11
Teacher Table
Name
Description
Teacher ID
Unique ID for teacher
PersonalID
Personal ID for teacher
FirstName
First name of teacher
MiddleName
Middle name of teacher
LastName
Last name of teacher
Employment Date
Date of employment
[0136] Table 11 contains the information of the teachers. The system may retrieve the information of the teachers, such as, the personal ID number, the first name, middle name and last name of the teacher, as well as the date the teacher was employed to teach by the Teacher ID.
[0000]
TABLE 12
Teaching Notes Table
Name
Description
NoteID
Unique ID for the teaching notes
ContentType
Type of teaching content of the teaching notes
Content ID
Unique ID of the ContentType
TeacherID
Unique ID of the teacher to identify the author
Date
The creation date of the teaching notes
UsageCount
Number of times the teaching notes was used in a lesson
Note
Content of the teaching notes
Note Level
Level of difficulty or grade level of the Teaching notes
[0137] Table 12 contains the information of the teaching notes. The system may retrieve the content of the teaching notes, content type, level of difficulty, author, creation date and usage count by the NoteID. The Date and UsageCount keep track of the number of times the teaching notes have been selected to show to the students, and the teaching notes below a predetermined selection rate in a period of time will be automatically deleted.
[0000]
TABLE 13
Class Memo Table
Name
Description
ClassMemoID
Unique ID for the class memo
LessonID
Unique ID of the Lesson
TeacherID
Unique ID of the teacher to identify the author
Date
The creation date of the class memo
Memo
Content of the class memo
[0138] Table 13 contains the information of the class memo. The system may retrieve the content of the class memo, its date of creation, lesson and author by ClassMemoID.
[0000]
TABLE 14
Student Memo Table
Name
Description
StudentMemoID
Unique ID for the student memo
LessonID
Unique ID of the Lesson
StudentID
Unique ID of the student to identify the author
Date
The creation date of the student memo
Memo
Content of the Student memo
[0139] Table 14 contains the information of the student memo. The system may retrieve the content of the student memo, its date of creation, lesson and author by StudentMemoID.
[0000]
TABLE 15
ModeLevel Table
Name
Description
ModelLevelID
Unique ID for the ModeLevel
Level
Level of difficulty of the teaching mode
Description
Description on the content of the teaching mode
[0140] Table 15 contains the information of the level of difficulty of the teaching mode. The system may retrieve level of difficulty of the teaching mode and its related content by ModeLevelID.
[0141] There are also databases containing other information, for example, the instructions to the students, the examples from the students to be used in quiz or test, the common error made by the students for teaching purpose and future reference, and the object of learning (e.g. vocabulary and phrasal verb) in other languages, which are used in the guided teaching session as described in the disclosed embodiments.
[0142] In addition to be used in class teaching, the present invention is also applicable in one-to-one teaching and long distance learning via the Internet. The present invention is not limited to teaching in school, but is also applicable to training in various aspects.
[0143] While the invention has been described in detail with reference to disclosed embodiments, various modifications within the scope of the invention will be apparent to those of ordinary skill in this technological field. It is to be appreciated that features described with respect to one embodiment typically may be applied to other embodiments. | The present invention is a computer aided method and system for guided teaching and learning with the aid of an optional communication device, comprising the steps of: (a) presenting a question to the student at a student display; (b) receiving answer from the teacher at the teacher workstation, wherein the answer is received by the teacher from the student or directly from the students remotely; (c) sharing the answer submitted on at least one student displayed) determining whether the answer is correct; (e) presenting feedback to the answer at all student displays or workstations; (f) receiving input from the teacher at the teacher workstation for the teacher to give further information related to the question on student display; and (g) presenting information using a plurality of styles and stimuli corresponding to the input from the teacher or student on the student display. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not applicable.
INCORPORATION-BY-REFERENCE OF MATERIALS SUBMITTED ON A COMPACT DISC
[0004] Not applicable.
BACKGROUND OF THE INVENTION
[0005] 1. Field of the Invention
[0006] The present invention relates to a progressive damping device for furniture, which is designed to prevent impacts between the mobile parts of furniture provided with self-closing systems, and provides progressive closure according to the speed and energy acquired in the closure, whilst complying with a general composition comprising a cylinder in which a dynamic fluid circulates, and in the interior of which there is displaced a piston which has a rod provided with an elastoplastic valve, which delimits respective compression and expansion chambers.
[0007] 2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
[0008] In this field there are known devices provided with dampers for furniture with a self-closing system, for the purpose of preventing impact between the mobile part of the furniture, such as a drawer, and the fixed part. Amongst these devices, reference can be made to Spanish patent P-200400369 “Damping device for furniture” by the same inventor, which describes a damper based on a fluid-dynamic cylinder in which the cylindrical body is provided with a piston which is displaced in relation to the cylindrical body. The said piston has a cylindrical form and is modified by two faces which are opposite one another, and the dimensions of which decrease to form a coaxial extension. However, this damping mechanism does not provide progressive damping based on speed.
[0009] In order to prevent problems of impact of the furniture during closure by obtaining progressive damping, a number of devices have been developed, most of which are highly complex, thus adding to their production costs and making assembly difficult. In order to solve this problem, the same applicant submitted the additional Spanish patent P-200500139, in which graduation of the damping action was achieved according to the speed of the impulse to be damped. For this purpose, this damping device comprises an inner cylindrical sleeve which is prolonged by means of a strip of an elastoplastic nature, and extends diametrically in the form of a bridge which projects beyond the point of the extension of the piston in the form of a basket. This basket will permit graduation in the damping of the closure of the furniture by means of its resilient flexure, but the part which is provided with the basket is produced by injection, and the point of injection coincides with the strip of the basket. This means that it is difficult to predict the exact modulus of flexure, including the origin of possible points of occurrence of rupture cracks.
[0010] These problems are exacerbated by the dimensions of the parts with a greatly reduced size. In addition, this basket forms together with the extension of the piston an end in the form of a crosspiece, which is interposed in the fluid discharge flow.
BRIEF SUMMARY OF THE INVENTION
[0011] In view of this situation, the present invention proposes a device for damping progressively according to speed, which comprises a cylinder body in which a dynamic fluid circulates, and the interior of which comprises a piston with a rod which extends from the cylinder body, and delimits two chambers, one for compression in the damping, and the other for expansion, which, depending on the position of the piston, have a variable volume.
[0012] The piston is a cylindrical sleeve which contains in its interior a displaceable elastoplastic valve, which is provided with symmetrical resilient fins with a total radial dimension which is greater than the inner diameter of the interior annular projection of the cylindrical sleeve. The longitudinal position of these resilient fins when not flexed being such that their distance to the wall which closes the head of the elastoplastic valve is greater than the distance between the active side of the interior annular projection and the seating wall of the cylindrical sleeve, with these resilient fins reaching the active side of the interior annular projection before the wall which closes the head of the elastoplastic valve abuts the seating wall of the cylindrical sleeve.
[0013] The resilient fins of the elastoplastic valve are equidistant, there are preferably two of them, and their radial length is larger than the smaller inner diameter of the interior annular projection of the cylindrical sleeve, including in the state of flexure of the resilient fins.
[0014] The cylindrical sleeve has its interior annular projection with its respective sides equidistant from the seating walls of the cylindrical sleeve, thus facilitating its reversible assembly.
[0015] The point of support of the resilient fins on the interior annular projection of the cylindrical sleeve will be derived from the impact provided in the movement in the direction of damping, on the active side of the annular projection.
[0016] As far as the functioning is concerned, account must be taken of the fact that this is a device for damping progressively according to the speed and the force of the impact. Consequently, when there is a normal closure speed or a normal impact, the resilient fins are supported on the active side of the interior annular projection, without being flexed, and the closure wall of the head of the elastoplastic valve remains at a minimum distance from the seating wall of the cylindrical sleeve. In this case, the dynamic fluid will flow both through the cylindrical sleeve and the elastoplastic valve, and via the exterior of this cylindrical sleeve.
[0017] In the case when the impact force is high, there is a high impact, or the closure force is greater, the resilient fins will be supported on the active side of the annular projection, and will be flexed to a greater or lesser extent, depending on the energy which they absorb in the impact, by this means achieving progressive damping. The closure wall of the head of the elastoplastic valve is supported completely on the seating wall of the cylindrical sleeve, such that the passage of the dynamic fluid in the interior of the cylindrical sleeve is closed.
[0018] When the fluid absorbs to a large extent the energy of the initial impact, the resilient fins will abandon their flexed position, since the system is balanced. In this position, the head of the elastoplastic valve will be situated in the low-impact position, and there will once more be a minimum distance between the closure wall and the seating wall of the cylindrical sleeve, thus permitting the passage of the fluid through the cylindrical sleeve and the elastoplastic valve, as well as on the exterior of this cylindrical sleeve.
[0019] This device must be able to be re-armed for further use, and so on. Consequently it must be ensured that the re-arming process can be undertaken with a lesser effort, i.e. the flow of fluid transferred between the expansion and compression chambers in the re-arming phase must be greater than in the braking phase.
[0020] The cylindrical sleeve, for its part, is symmetrical in relation to its two axes, which results in greater ease of assembly and production. Each wall of the cylindrical sleeve will have a different function, depending on the position in which the assembly is carried out.
[0021] With reference to the configuration of the elastoplastic valve, in its production there will be no breakage points in the injection process, since this injection need not be carried out at any specific geometric point, and no critical dimensions arise. This facilitates the production process and subsequent assembly, since the part is symmetrical relative to its longitudinal axis.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0022] In order to understand better the nature of the invention, the attached drawings represent an industrial embodiment, purely by way of illustrative and non-limiting example.
[0023] FIG. 1 is a cross-section of the damping device at the beginning of the path, showing in perspective an enlarged detail of the elastoplastic valve ( 6 ), the cylindrical sleeve ( 10 ) and the cylinder body ( 1 ) in dismantled form.
[0024] FIG. 2 is a schematic view of the damping device in the position corresponding to the beginning of the path of the piston ( 2 ), indicating the corresponding detail of the elastoplastic valve ( 6 ) and the cylindrical sleeve ( 10 ) in this position.
[0025] FIG. 3 is a schematic view of the damping device in the position corresponding to the end of the path of the piston ( 2 ).
[0026] FIG. 4 is an enlargement of the detail shown in FIG. 2 , and is a view in cross-section of the damping device at the beginning of the path.
[0027] FIG. 5 is a schematic view of the damping device when a low impact occurs during the closure.
[0028] FIG. 6 is a schematic view of the damping device when a high impact occurs during the closure.
[0029] FIG. 7 shows the cross-section indicated in FIG. 8 , according to line VII-VII′ of the cylindrical sleeve ( 10 ).
[0030] FIG. 8 shows the profile of the cylindrical sleeve ( 10 ).
[0031] FIG. 9 is the front view of the elastoplastic valve ( 6 ).
[0032] FIG. 10 is the profile view of the elastoplastic valve ( 6 ).
[0033] FIG. 11 is the plan view of the elastoplastic valve ( 6 ).
[0034] In these figures, the following alphanumerical references are given:
1 —Cylinder body 2 —Piston 3 —Piston rod ( 2 ) 4 —Chamber for compression in damping 5 —Expansion chamber 6 —Elastoplastic valve of the piston ( 2 ) 7 —Resilient fins of the elastoplastic valve ( 6 ) 8 —Stops of the elastoplastic valve ( 6 ) 9 —Elastoplastic valve head ( 6 ) 9 a —Wall which closes the head ( 9 ) 10 —Cylindrical sleeve of the piston ( 2 ) 10 a —Cylindrical sleeve wall ( 10 ) 11 —Interior annular projection of the cylindrical sleeve ( 10 ) 11 a —Interior annular projection side ( 11 ) 12 —Fluid transfer lines.
DETAILED DESCRIPTION OF THE INVENTION
[0050] With reference to the aforementioned references and drawings, the appended plans illustrate a preferred embodiment of the subject of the invention, with reference to a progressive damping device for furniture which, as illustrated in FIG. 1 , comprises a cylinder body ( 1 ) through which a dynamic fluid circulates, and the interior of which comprises a piston ( 2 ) which has a rod ( 3 ) which extends outside the cylinder body ( 1 ), and delimits two chambers, for compression during damping ( 4 ), and for expansion ( 5 ), and which have a variable volume, depending on the position of the piston ( 2 ) ( FIGS. 2 and 3 ).
[0051] As illustrated in FIG. 1 , the piston ( 2 ) is a cylindrical sleeve ( 10 ) which contains in its interior a displaceable elastoplastic valve ( 6 ) which is provided with symmetrical resilient fins ( 7 ) with a total radial dimension which is greater than the inner diameter of the interior annular projection ( 11 ) of the cylindrical sleeve ( 10 ), the longitudinal position of these resilient fins ( 7 ) when not flexed being such that their distance to the wall ( 9 a ) which closes the head ( 9 ) of the elastoplastic valve ( 6 ) is greater than the distance between the active side ( 11 a ) of the interior annular projection ( 11 ) and the seating wall ( 10 a ) of the cylindrical sleeve ( 10 ), with these resilient fins ( 7 ) reaching the active side ( 11 a ) of the interior annular projection ( 11 ) before the wall ( 9 a ) which closes the head ( 9 ) of the elastoplastic valve ( 6 ) abuts the seating wall ( 10 a ) of the cylindrical sleeve ( 10 ).
[0052] The resilient fins ( 7 ) of the elastoplastic valve ( 6 ) are equidistant, there are preferably two of them, and their radial length is larger than the smaller inner diameter of the interior annular projection ( 11 ) of the cylindrical sleeve ( 10 ), including in the state of flexure of the resilient fins ( 7 ). The dimensions of the length and thickness of these resilient fins ( 7 ) can be determined accurately, and different numbers and forms of the fins can be combined, since it is possible to opt for embodiments with three or four resilient fins ( 7 ), with thicknesses and lengths which differ from one another.
[0053] The cylindrical sleeve ( 10 ) has its interior annular projection ( 11 ) with its respective active sides ( 11 a ) equidistant from the respective seating wall ( 10 a ), thus facilitating its reversible assembly.
[0054] The point of support of the resilient fins ( 6 ) on the interior annular projection ( 11 ) of the cylindrical sleeve ( 10 ) will be derived from the impact provided in the movement in the direction of damping, on the active side ( 11 a ) of the interior annular projection ( 11 ).
[0055] As far as the functioning is concerned, account must be taken of the fact that this is a device for damping progressively according to the speed and the force of the impact.
[0056] As can be seen in FIG. 5 , when there is a normal closure speed or a normal impact, the resilient fins ( 7 ) are supported on the active side ( 11 a ) of the interior annular projection ( 11 ), without being flexed, and the closure wall ( 9 a ) of the head of the elastoplastic valve ( 6 ) remains at a minimum distance from the seating wall ( 10 a ) of the cylindrical sleeve ( 10 ). In this case, the dynamic fluid will flow both through the cylindrical sleeve ( 10 ) and the elastoplastic valve ( 6 ), and via the exterior of this cylindrical sleeve ( 10 ).
[0057] In the case when the impact force is high, there is a high impact, or the closure force is greater, as illustrated in FIG. 6 , the resilient fins ( 6 ) will be supported on the active side ( 11 a ) of the annular projection ( 11 ), and will be flexed to a greater or lesser extent, depending on the energy which they absorb in the impact, by this means achieving progressive damping. The closure wall ( 9 a ) of the head of the elastoplastic valve ( 6 ) is supported completely on the seating wall ( 10 a ) of the cylindrical sleeve ( 10 ), such that the passage of the dynamic fluid in the interior of the cylindrical sleeve ( 10 ) is closed.
[0058] When the fluid absorbs to a large extent the energy of the initial impact, the resilient fins will abandon their flexed position, since the system is balanced. In this position, the head ( 9 ) of the elastoplastic valve ( 6 ) will be situated in the low-impact position, and there will once more be a minimum distance between the closure wall ( 9 a ) and the seating wall ( 10 a ) of the cylindrical sleeve ( 10 ), thus permitting the passage of the fluid through the cylindrical sleeve ( 10 ) and the elastoplastic valve ( 6 ), as well as on the exterior of this cylindrical sleeve ( 10 ).
[0059] This device must be able to be re-armed for further use, and so on. Consequently it must be ensured that the re-arming process can be undertaken with a lesser effort, i.e. the cross-section of passage of the flow of fluid transferred between the expansion and compression chambers in the re-arming phase must be greater than in the braking phase.
[0060] As illustrated in FIG. 4 , the stops ( 8 ) of the elastoplastic valve ( 6 ) are supported on the interior annular projection ( 11 ) in the re-arming phase, so that the cylindrical sleeve ( 10 ) moves together with the elastoplastic valve ( 6 ).
[0061] The cylindrical sleeve, for its part, is symmetrical in relation to its two axes, which results in greater ease of assembly and production. In other words, each wall of the cylindrical sleeve will have a different function, depending on the position in which the assembly is carried out.
[0062] With reference to the configuration of the elastoplastic valve ( 6 ), in its production there will be no breakage points in the injection process, since this injection need not be carried out at any specific geometric point, and no critical dimensions arise. This facilitates the production process and subsequent assembly, since the part is symmetrical relative to its longitudinal axis. | A progressive damping device for furniture is designed to prevent impacts between the mobile parts of furniture provided with self-closing systems, and provides progressive closure according to the speed and energy acquired in the closure. The damping device generally includes a cylinder in which a dynamic fluid circulates, and in the interior of which there is displaced a piston which has a rod provided with an elastoplastic valve, which delimits respective compression and expansion chambers. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/278,880 filed Oct. 13, 2010, which is incorporated herein by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to a method of synthesizing a tetradentate amido macrocyclic ligand and its metal complex.
[0005] 2. Brief Description of the Related Art
[0006] Macrocyclic ligands with various donor atoms are very important to stabilize metals with high valent oxidation states. Such macrocyclic complexes play a significant role in mimicking either structure and/or functions of several metallo enzymes, especially enzymes which use hydrogen peroxides or oxygen for their activity. Amongst many, the development of oxidation resistant stable tetraamido macrocyclic ligand (TAML) developed by Collins and co-workers has drawn much attention in the last two decades or more.
[0007] Various metal complexes with unusually high oxidation states using TAMLs have been frequently reported previously by Collins et al. Interestingly, iron complexes of TAMLs (Fe-TAMLs) posses a unique property of activating either hydrogen peroxide or oxygen and act as green oxidation catalysts. Using Fe-TAML and hydrogen peroxide in water, several oxidation chemistries have been demonstrated starting from pollutants remediation associated with the textile, pulp and paper, and pesticides industries to rapidly killing anthrax-like spores and removing sulfur from hydrocarbon fuels. In order to synthesize TAMLs, several synthetic routes have been reported with varying success. In one such instance to synthesize the macrocyclic ligands uses of inorganic or organic azides were encountered, which is not desirable in terms of safety. Coupling of an aromatic diamine and a diacid derivative in a two step process has been utilized; however, yield of ligands using this method is very low.
[0008] In recent years an improved synthetic method TAML ligand has been reported. The method uses synthesis of phthalic acid protected amino acid derivatives and then subsequently macrocycle synthesis using several steps. Uffelman and co-workers developed a new synthetic method of making acid chloride of amino acids using phosphorous pentachloride in presence of and reacting with the aromatic amines. Even though over the years easier methods have been developed, synthesis of such macrocyclic ligands needs a much simpler approach.
[0009] Several tons of hydrogen peroxide (H 2 O 2 ) are annually used for stoichiometric oxidation purposes. The activity of H 2 O 2 can be enhanced by using various metal complexes. However, the major challenge is to find suitable metal complexes, which can withstand both oxidative stress and also attain high valent metal oxidation states for activity. In this context, a major research effort has evolved over the years focused on the development of metal complexes which mimic structures and/or functions of H 2 O 2 or oxygen activating metallo-enzymes. Ligands that possess various donor atoms and geometries are very important in order to achieve suitable H 2 O 2 activating metal complexes or catalysts.
[0010] Examples of metal ligand containing bleaching compositions are found in U.S. Pat. Nos. 6,241,779; 6,136,223; 6,099,586; 5,876,625 and 5,853,428, the disclosures of which are incorporated herein be reference. An example of a long-lived homogenous amide containing macrocyclic compounds is found in U.S. Pat. No. 6,054,580, the disclosure of which is incorporated herein by reference.
BRIEF SUMMARY OF INVENTION
[0011] To achieve the above objectives, the present invention is directed to a new method of synthesis for a tetradentate amido macrocyclic ligand and its metal complex, resulting in much higher yields. Further, the newly synthesized Fe-complex has been tested as an activator of H 2 O 2 and found to be very efficient in performing various oxidation chemistries.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0012] FIG. 1 is the molecular structure of tetradentate amidomacrocyclic ligand and its Fe-complex.
[0013] FIG. 2 is the reaction scheme leading to the production of tetradentate amidomacrocyclic ligand.
[0014] FIG. 3 is the electro spray ionization mass spectrum (ESI-MS) of Fe-Complex (negative ion mode) and its theoretical isotope distribution (inset).
[0015] FIG. 4 is a graphical depiction of the change of absorbance as a function of time and wavelength.
[0016] FIG. 5 is a table listing the dyes that were bleached and the time of bleaching at pH 10 and ph 11.5.
[0017] FIG. 6 shows the molecular reaction of oxidation of a tertiary amine to its corresponding N-oxide.
[0018] FIG. 7 is a chart listing the turn over numbers and percent yield for pyridine, triethylamine, and 4-dimenthylaminopyridine synthesis.
DETAILED DESCRIPTION OF THE INVENTION
[0019] With reference to FIGS. 1-7 , the new methodology of synthesizing tetradentate amide based macrocyclic ligand and its iron complex can be described. The molecular structure of tetradentate amide based macrocyclic ligand 1 and its iron complex 2 are shown in FIG. 1 . Tetradentate amide based macrocyclic ligand 1 was synthesized using standard reactions of amine and acid chlorides with high yield. Ligand 1 was used to develop its iron complex 2, which is soluble and stable in aqueous solution. Iron complex 2 activates H 2 O 2 in water under ambient conditions and acts as an excellent oxidation catalyst.
[0020] A new tetradentate amide based macrocyclic ligand 1 and its Fe-complex 2 are synthesized according to FIG. 2 . More specifically, O-phenylenediamine (3 gm, 27.8 mmol) and triethylamine (27.8 mmol, 3.8 mL) were dissolved in 47 mL of dry THF (dried over sodium and benzophenone). Di-tert-butyl-carbonate (6.05 gm, 27.8 mmol) was dissolved in 50 mL of THF. Both the solutions were combined in two gas tight syringes separately and added in a three neck round bottom flask containing 50 mL THF via a syringe pump at 0° C. The addition was completed within 16 hours. The reaction mixture was then further stirred at room temperature for another 4 hours. After the reaction, solvent was removed using a rotoevaporator. The residue was dissolved in 200 mL dichloromethane and washed with 5% Na 2 CO 3 (3×100 mL). The organic layer was collected and dried using anhydrous sodium sulfate. After filtration, the organic layer was concentrated using a rotoevaporator to yield the slightly yellow product 3. The compound was further purified by recrystallizing from benzene. Initially one of the amine groups of O-phenylenediamine was protected with a tert-butyloxycarbonyl (BOC) group to obtain (2-Amino-phenyl)-carbamic acid tert-butyl ester 3. The stability of the BOC group under basic conditions and its easy removal by acids is of primary advantage for synthesizing the ligand following this method.
[0021] Compound 4 was synthesized through a reaction involving (2-Amino-phenyl)-carbamic acid tert-butyl ester 3. More specifically, (2-Amino-phenyl)-carbamic acid tert-butyl ester 3 (2.08 gm, 10 mmol,) was dissolved in 50 mL dry THF. To this solution was added triethylamine (1.4 mL, 10 mmol). The mixture was transferred to a 100 mL two neck round bottom flask and cooled to 0° C. Dimethylmalonyl chloride (1.45 mL, 11 mmol) dissolved in 50 mL dry THF was added into a dropping funnel and the solution was combined slowly for 60 minutes to the other solution drop-wise under nitrogen atmosphere. During the addition, a white precipitate was noted to be formed. The free amine group of (2-Amino-phenyl)-carbamic acid tert-butyl ester 3 reacts with both acid chlorides of dimethylmalonyl chloride to produce compound 4. The reaction proceeds very rapidly in the presence of a triethylamine. Low temperature was maintained since the reaction is an exothermic reaction. After addition of dimethylmalonyl chloride, the reaction mixture was brought to room temperature and stirred overnight under inert atmosphere. After the reaction, the solution was filtered to remove insolubles and filtrate was collected. The residue was dissolved in 200 mL dichloromethane and washed with 5% Na 2 CO 3 (3×100 mL). The organic layer was collected and dried using anhydrous sodium sulfate. After filtration, the organic layer was concentrated using a rotoevaporator to yield an off-white crude product, compound 4. Following evaporation of the solvent, the product was washed with diethyl ether and dried in vacuum. The compound 4 was further purified by recrystallizing from benzene.
[0022] In the next step, the BOC protecting group was removed by treating with trifluoroacetic acid, which occurs within minutes. Compound 4 (1.5 gm, 3.18 mmol) was dissolved in 10 mL dichloromethane and cooled to 0° C. To this solution was added a mixture of trifluoroacetic acid (10 mL) and dichloromethane (20 mL) drop-wise over a period of 30 min under inert atmosphere. After the addition, the reaction mixture was brought to room temperature and stirred for another 2 hours. The reaction mixture then was concentrated using a rotoevaporator to obtain a slightly yellow viscous liquid. This solution was diluted with 75 mL of water and the pH was adjusted with enough 1 M sodium hydroxide solution to bring the pH of the solution to 10 and then extracted with 20 mL of dichloromethane (3×20 mL). The organic layer was dried using anhydrous sodium sulfate. After filtration, the organic layer was concentrated using rotevaporator to yield the white product of compound 5.
[0023] For the synthesis of 3, 4 and 5, either washing with dilute mineral acid and/or bases or simple recrystallization from benezene was performed to purify the product with no column chromatography required. Compound 5 (0.408 g, 1.31 mmol) was dissolved in 30 mL dry THF and to the solution was added triethylamine (0.38 mL). The solution was collected in a gas tight syringe. Oxalyl chloride (0.11 mL, 1.31 mmol) was dissolved in 30 mL dry THF and collected in another gas tight syringe. Both solutions were added drop-wise via syringe pump, into a round bottom flask containing 30 mL dry THF that had been cooled to 0° C. and maintained under inert atmosphere. The addition was completed in 16 hours. The mixture was allowed to continue stirring for an additional 4 hours at room temperature. Finally, ligand 1 was synthesized by adding separate solutions of oxalyl chloride and compound 5 in tetrahydrofuran very slowly using a syringe pump. This process is required to reduce other side reactions and maximize macrocycle production. In fact, the structure of 5 may be helpful to some extent in keeping the two amine groups close together which can easily react with oxalyl chloride to form the macrocycle. During the reaction the macrocycle precipitates out from the solution and can be recovered just by simple filtrations. Washing with water was necessary to remove any triethylamine hydrochloride salt which co-precipitates with the ligand during reaction. The resulting product was transferred to a round bottom flask and 200 mL of diethyl ether added. The mixture was sonicated for 15 minutes and then filtered. The precipitate was collected and rinsed with additional ether to further purify the material. The resulting product was dried for 12 hours under vacuum at 80° C. to yield the desired macrocyclic ligand 1. The 1 H-NMR spectra for all the intermediates including the macrocycle were obtained and indicates the formation of the compounds.
[0024] After synthesizing the ligand 1, the Fe-complex 2 was developed. Ligand 1 was first deprotonated using a strong base and reacted with ferrous chloride in dry tetrahydrofuran. More specifically, 1 (200 mg, 0.61 mmol) was dissolved in 30 mL dry THF in a 100 mL Schlenk flask containing a magnetic stir bar and fitted with an N 2 gas line. The mixture was cooled to 0° C. using an ice bath. To this mixture was added n-butyllithium (2.56 mmol, 1 mL) and the reaction mixture was stirred for 15 minutes. After stirring for an additional 15 minutes at room temperature, ferrous chloride (85.217 mg, 0.67 mmol) was added and the solution was allowed to stir overnight under N 2 atmosphere. During the reaction the mixture turned deep brown. After exposing the reaction mixture to air, the desired Fe(III)-complex 2, which precipitated from the solution, was collected by filtration. The Fe-complex 2 was purified simply by passing through an alumina column.
[0025] Electro spray ionization mass spectrum (ESI-MS) of the metal complex was obtained and indicates the formation of the metal complex as shown in the FIG. 3 . The calculated isotopic distribution is shown in FIG. 3 inset and is in full agreement with the actual isotope distribution observed. The composition of the complex was further verified by elemental analysis which is in agreement with that of desired product. Electrochemical study shows that Fe-complex 2 has two electrochemically reversible peaks at E 1/2 =0.64 V (E p =63 mV) and E 1/2 =0.84 V (E p =77 mV) corresponding to two successive one electron oxidations.
[0026] The complex is stable in neutral to alkaline aqueous solutions for several days at moderately high temperature (60-70° C.). However, heating of the aqueous solution of the Fe-complex to 90° C. causes the catalyst to demetallate rapidly as indicated by changes in the UV-Vis spectra. Demetallation gives rise to the free ligand, which was verified by 1 H-NMR. This is a limitation of using complex 2 at very high temperature. Macrocyclic ring size of thirteen atoms and amide planarity are critical for hydrolytic stability of iron complexes of deprotonated amide ligands. A tetradentate amide ligand with a ring size of fourteen atoms has been reported but the Fe-complex was found to be extremely unstable in water. In the present invention, complex 2 has been synthesized with a ring size of thirteen atoms and the size provides adequate stability to the Fe-complex in aqueous solution.
[0027] The catalytic behavior of the complex as an H 2 O 2 activator in a variety of oxidation processes is shown in FIGS. 4-5 . A working solution of catalyst 2 in Na 2 EDTA carbonate/bicarbonate buffer (pH 10) was prepared for use in all reactions. This was done by adding 66.6 μL of a 15,000 ppm EDTA stock solution and 100 μL of a 0.5 mM solution of catalyst 2 to a 100 mL volumetric flask followed by mixing and dilution with 0.1 M carbonate/bicarbonate buffer (pH 10). Final concentrations of EDTA and catalyst 2 were 10 ppm and 0.5 μM respectively. 2980 μL of this working solution was placed in a quartz cuvette fitted with a magnetic stir bar inside. To this solution was added 10 μL of a 3.6 mM purified dye solution (Final dye concentration: 12 μM). The bleaching experiment was initiated by adding 10 μL of 9.4 M H 2 O 2 to the dye solution in the cuvette yielding a H 2 O 2 concentration of 31.3 mM. The change of absorbance was monitored as a function of time at the specified wavelengths. Similarly bleaching of all the dyes were also checked using H 2 O 2 alone at pH 10 and 11.5.
[0028] Several water soluble organic dyes were bleached at room temperature in aqueous carbonate/bicarbonate buffer (pH 10) using complex 2 in presence of H 2 O 2 as primary oxidant. Organic dye (12 μM) and a small amount of catalyst (0.5 μM) were combined in buffer solution and the reaction was initiated by adding H 2 O 2 (3 mM). A small amount of sodium salt of ethylenediamine tetraacetate (EDTA) was added into the reaction mixture to remove any free transition metal ion in the solution and thus minimize hydroxyl radical dominated chemistry. FIG. 4A shows the bleaching of several dyes at room temperature. FIG. 5 shows the list of dyes which were bleached using complex 2. λ max was the wavelength used to determine bleaching time. Bleaching time is defined to be the time at which both A≦half of initial value and the slope of A vs time curve approaches zero for a chosen λ max . All the reactions were performed in pH 10 or 11.5 carbonate buffer with 10 ppm EDTA, dye concentration of 12 μM, H 2 O 2 concentration 31.3 mM, and catalyst 2 concentration of 0.5 μM at 25° C. Methyl Violet, Clayton Yellow, Orange IV, Napthol B green were bleached rapidly. However, the bleaching of Methyl Orange was very slow. H 2 O 2 alone when tested to bleach the dyes under similar conditions was found to be much slower in bleaching the dyes. FIG. 4A shows the bleaching of Orange IV in presence of H 2 O 2 at pH 10 which shows practically no bleaching of dyes. The catalyst however becomes inactivated after a certain time and bleaching is not as effective as previously reported with Fe-TAML catalysts. The bleaching experiment was also done at pH 11.5 and testing did not show any difference in activity compared to experiments at pH 10.
[0029] The ability of the catalysts to remove color from pulp and paper effluent along with H 2 O 2 under ambient conditions was also determined. The pH of the effluent was adjusted to 9.5 using concentrated sodium hydroxide solution. To 100 mL of the effluent solution was added 600 μL 2.17 mM solution of catalyst 2. 300 μL 9.4 M hydrogen peroxide was added to this solution and stirred at room temperature for 4 hours. As a control, to another 100 mL effluent solution, was added 300 μL 9.4 M hydrogen peroxide that was also stirred for 4 hours at room temperature. The solutions were diluted and absorbances of the solutions were measured and compared to the unbleached solutions. Absorbances at 466 nm were recorded and used to calculate color disappearance. FIG. 4B revealed that catalyst 2 (13 μM; 6 mg catalyst/L effluent) can remove 52% color (calculated using absorbance at 466 nm) of the effluent within 4 hours at pH 9.5. H 2 O 2 itself can also remove color under similar reaction conditions although bleaching is less (30%).
[0030] FIG. 6 shows the oxidization of a tertiary amine to its corresponding N-oxides, which have tremendous usefulness both in synthetic and biological applications. The reactions were carried out at pH 10 using catalyst 2 and H 2 O 2 at room temperature. The reactions show turn over numbers of 667 with very good yields of N-oxides. For comparison, amines were also oxidized with only hydrogen peroxide. The N-oxides (products) and reactants (amines) were checked after the reaction either by GC/MS or ESI-MS. Pyridine (0.05 mL, 0.620 mmol) was added to 1 mL 0.1 M carbonate/bicarbonate buffer. To this solution was added 0.34 mL of 9.4 M hydrogen peroxide (3.10 mmol) and 0.36 mL of 2.15×10 −3 M of catalyst 2 (0.775 μmol). The solution was stirred at room temperature for 2 hours. An aliquot of the solution was added to acetonitrile, filtered and analyzed by GC/MS to check the N-oxide of pyridine. Product formation was checked by LC/MS too. No other detectable product was observed under the reaction condition. Quantification of product was performed by checking the disappearance of pyridine by GC/MS. As shown in FIG. 7 , a turn over number (TON=Moles of product formed/moles of catalyst) of 407 was observed for pyridine-N-oxide synthesis. Under the reaction conditions, 50.8% yield of product was obtained. When hydrogen peroxide alone was used, only 20% yield was obtained under similar conditions. In case of trienthylamine, a higher TON of 667 was obtained with 66.67% yield. 4-Dimethylaminopyridine was also used for the reaction. Corresponding N-oxide formation was checked by mass spectrometer but not quantified.
[0031] The Fe-Complex may be used as an activator of hydrogen peroxide for oxidation purposes, including without limitation, (a) pulp and paper effluent bleaching, (b) dye bleaching, and (c) small molecule synthesis by oxidation (e.g. N-oxides, epoxides, aldehydes and the like may be synthesized from the oxidation of suitable precursor molecules).
[0032] The present invention has been described with reference to certain preferred and alternative embodiments that are intended to be exemplary only and not limiting to the full scope of the present invention as set forth in the appended claims. | A tetradendate amide based macrocyclic ligand and its Fe(III) complex which act as activators of hydrogen peroxide. The synthetic methodology to develop the ligands is new, simple and provides better yield for each step of the ligand synthesis. The Fe(III)-complexes and hydrogen peroxide together are can perform several environmentally benign oxidation reactions. Organic dye bleaching, bleaching of pulp and paper effluent and N-oxide synthesis may be performed using the newly developed catalyst and hydrogen peroxide. Alcohol oxidation and alkene epoxidation may also be performed using the catalysts and hydrogen peroxide. | 3 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application is related to, claims priority from and incorporates by reference Japanese Patent Application No. 2011-181664, filed on Aug. 23, 2011.
TECHNICAL FIELD
[0002] The present invention relates to an image forming apparatus, especially relates to a configuration of a medium stacking device including a guide for a medium to be stacked.
BACKGROUND
[0003] Conventionally, in such a medium stacking device, in order to regulate a position of a sheet in a width direction which is orthogonal to a carrying direction of the stacked sheet, two sheet guides have been disposed at the left and right of the sheet (see JP Laid-Open Patent Application No. H8-034525 (page 3, FIG. 1 ).
[0004] However, since the conventional sheet guide cannot completely prevent an incline of the guided medium, the medium is sometimes inclined with respect to the carrying direction. One of objects of the present invention is to eliminate the above mentioned problems by a simple configuration.
SUMMARY
[0005] A medium stacking device of the present invention includes a medium stacking part stacking a medium, and a first movement part movably provided with respect to the medium stacking part. The first movement part has a first medium restriction part restricting a position of the medium, and a first movement restriction part including a plurality of restriction members, each of which engaging with the medium stacking part and restricting a direction of the movement of the first movement part.
[0006] According to the present invention, the first movement part can minimize the incline of the medium which is being carried.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a schematic configuration diagram of a main part configuration viewed from the front surface of an image forming apparatus of a first embodiment employing a medium stacking device according to the present invention.
[0008] FIG. 2 is a configuration diagram viewed from the front surface (Y axis plus side) of a manual feed tray in the first embodiment.
[0009] FIG. 3 is an external perspective view illustrating the configuration of the medium stacking device in the first embodiment.
[0010] FIG. 4 is a configuration diagram viewed from the lower side of the medium stacking device in the first embodiment.
[0011] FIG. 5 is an external perspective view illustrating a configuration of the surface (upper surface) of a medium stacking plate of the medium stacking device.
[0012] FIG. 6 is an external perspective view illustrating a configuration of the rear surface (lower surface) of the medium stacking plate.
[0013] FIG. 7 is an external perspective view illustrating a configuration of a sheet guide illustrated in FIG. 3 in the first embodiment.
[0014] FIG. 8 is a diagram excluding the medium stacking plate from the configuration diagram of FIG. 4 in the first embodiment.
[0015] FIG. 9 is a K-K cross-sectional view illustrating a cross-section along a position passing a center of screws illustrated in FIG. 4 in the first embodiment.
[0016] FIG. 10 is a size explanation diagram illustrating a position relationship between the sheet guide installed to the medium stacking plate and a pinion gear rotatably axially fixed to the medium stacking plate in the first embodiment.
[0017] FIG. 11A is a partially enlarged diagram for explaining an engagement position with a mesh of the pinion gear and a rack as an example in the first embodiment. FIG. 11B is a diagram illustrating another example of a mesh of the pinion gear and the rack in the first embodiment.
[0018] FIG. 12 is a diagram used to an operation explanation of the sheet guide of the medium stacking device stacking recording sheets in the first embodiment.
[0019] FIG. 13 is a configuration diagram viewed from the lower side of the medium stacking device in the second embodiment according to the present invention.
[0020] FIG. 14 is an M-M cross-sectional view illustrating a cross-section along a position passing a center of screws shown in FIG. 13 . The upper side of the medium stacking device is placed up.
[0021] FIG. 15 is a diagram used to an operation explanation of the sheet guide of the medium stacking device stacking recording sheets in the second embodiment.
[0022] FIG. 16 is a configuration diagram of the medium stacking device viewed from the lower side in the third embodiment according to the present invention.
[0023] FIG. 17 is an external perspective view illustrating a configuration of a sheet guide in the third embodiment.
[0024] FIG. 18 is an external perspective view illustrating a configuration of a sheet guide in the fourth embodiment.
DETAILED DESCRIPTION OF EMBODIMENTS
First Embodiment
[0025] In FIG. 1 , a sheet tray 51 is disposed, and a sheet feeding part 30 is provided in a sheet feeding side of the sheet tray 51 in the lower part of an image forming apparatus 1 having a configuration as an electrographic printer. Recording sheets 52 are stacked in the sheet tray 51 , and the sheet feeding part 30 feeds the recording sheets 52 as a media one by one. A pickup roller 31 , a feed roller 32 , and a separation piece 33 are provided in the sheet feeding part 30 . The pickup roller 31 is provided so as to be contacted and pressed against the recording sheets 52 stacked to a certain height. The feed roller 32 and the separation piece 33 separate the recording sheets 52 fed by the pickup roller 31 one by one.
[0026] A manual feed tray 300 is provided with a medium stacking device 302 , a pickup roller 303 , a feed roller 304 and a retard roller 305 . The recording sheets 370 ( FIG. 2 ) are stacked on the medium stacking device 302 . The pickup roller 303 is provided so as to be contacted and pressed against a contact part 311 ( FIG. 2 ) of a medium stacking plate 310 of the medium stacking device 302 . The feed roller 304 and the retard roller 305 separate the sheets one by one fed by the pickup roller 303 . The recording sheets 370 on the medium stacking device 302 are fed to the feed roller 304 by rotation of the pickup roller 303 by drive of motor (not shown), are separated one by one by the feed roller 304 and the retard roller 305 , and are sent to a sheet carrying part 40 .
[0027] The sheet carrying part 40 carries each of the recording sheets 52 that are separated into a sheet and fed from the sheet feeding part 30 to an image forming part 10 via carrying roller pairs 41 , 42 , and carries the recording sheets 370 ( FIG. 2 ) separated into a sheet and fed from the manual feed tray 300 via the carrying roller pair 42 to the image forming part 10 in the same manner. The image forming part 10 includes four toner image forming parts 11 K, 11 Y, 11 M, 11 C (if not necessary to be especially distinguished, may merely be referred to as a toner image forming part 11 ) sequentially and tandemly arranged from the upstream side of the carrying direction of the recording sheets 52 , 370 and, a transfer part 13 transferring a toner image formed by the toner image forming part 11 on the upper surface of the sheet by Coulomb force.
[0028] The toner image forming part 11 K forms a black (K) toner image. The toner image forming part 11 Y forms a yellow (Y) toner image. The toner image forming part 11 M forms a magenta (M) toner image. The toner image forming part 11 C forms a cyan (C) toner image. In each toner image forming part 11 , the photosensitive drum 12 is charged by a charging roller (not shown), image data is written on the rotating photosensitive drum 12 by a light head (not shown), and the image data is developed with toner. Thereby, each color of the toner images can be obtained on the photosensitive drum 12 .
[0029] The transfer part 13 includes a transfer belt 14 carrying the recording sheet 52 carried from the sheet tray 51 or the recording sheet 370 ( FIG. 2 ) carried from the manual feed tray 300 in the arrow direction, and four transfer rollers 15 disposed so as to face each photosensitive drum 12 of each toner image forming part 11 across the transfer belt 14 . The transfer part 13 sequentially transfers the toner image to the recording sheet 52 , the toner image for each color being formed by Coulomb force on each photosensitive drum 12 corresponding to each toner image forming part 11 .
[0030] A fuser 20 fixes the toner image transferred on the recording sheets 52 , 370 in the transfer part 13 on the recording sheet by heat and pressure. The recording sheets 52 , 370 on which the toner image is fixed are ejected on a stacking part 56 on which the printed recording sheets are stacked via a carrying roller pair 53 and an ejection roller pair 54 .
[0031] Each of the axes of X, Y, and Z, in FIG. 1 are as follows: X axis is the carrying direction when the recording sheet 52 passes the image forming part 10 ; Y axis is the rotation axial direction of the photosensitive drum 12 ; and Z axis is the direction orthogonal to the above mentioned axes. In addition, in a case where each of the axes of X, Y, and Z are shown in the other figures mentioned below, the rotation axial directions respectively indicates identical directions. That is, X, Y, and Z axes in each of the figures show disposition directions of description parts in each of figures configuring the image forming apparatus 1 shown in FIG. 1 . Note that the image forming apparatus 1 is herein disposed so that Z axis is a substantially vertical direction.
[0032] FIG. 2 is a configuration diagram viewed from the front surface (Y axis plus side) of a manual feed tray 300 . FIG. 3 is an external perspective view illustrating the configuration of the medium stacking device 302 . FIG. 4 is a configuration diagram viewed from the lower side of the medium stacking device 302 .
[0033] In FIG. 2 , a frame 301 of the manual feed tray 300 is fixed to the image forming apparatus 1 main body. The medium stacking device 302 stacking the recording sheets 370 is rotatably held by the frame 301 as mentioned below. Note that parts other than the manual feed tray 300 of the image forming apparatus 1 may referred to as the image forming apparatus 1 main body. The pickup roller 303 is dispose at a position so as to contact the contact part 311 of the medium stacking plate 310 of the medium stacking device 302 . The feed roller 304 is rotatably held by the image forming apparatus 1 main body, and is rotated and driven by a drive motor (not shown). An idler gear 306 links the pickup roller 304 to the feed roller 303 . The retard roller 305 is linked to a torque limiter (not shown). A spring 308 biases the retard roller 305 toward the feed roller 304 . A spring 309 biases the medium stacking device 302 toward a direction in which the contact part 311 of the medium stacking device 302 contact pickup roller 303 .
[0034] Note that the manual feed tray 300 herein, for example, includes the frame 301 , the medium stacking device 302 , the pickup roller 303 , the spring 309 , and the idler gear 306 .
[0035] As shown in FIG. 3 and FIG. 4 , the medium stacking device 302 includes the medium stacking plate 310 as a medium stacking part, a sheet guide 320 as a first movement part, a sheet guide 321 as a second movement part, a pinion gear 381 as a first gear part, and a pinion gear 382 as a second gear part. A pair of posts 335 , 336 formed on both of end parts of the medium stacking plate 310 are respectively inserted into guide grooves 301 a , 301 b ( FIG. 2 ) formed on the frame 301 . Thereby, the medium stacking device 302 is rotatably held. Furthermore, as mentioned above, the contact part 311 of the medium stacking device 302 is biased in the direction where the contact part 311 contacts the pickup roller 303 by the spring 309 . The pinion gears 381 and 382 are positioned along in the medium carrying direction and at a substantially middle of the sheet guides 320 and 321 .
[0036] FIG. 5 is an external perspective view illustrating a configuration of the surface (upper surface) of a medium stacking plate 310 of the medium stacking device 302 . FIG. 6 is an external perspective view illustrating a configuration of the rear surface (lower surface) of the medium stacking plate 310 .
[0037] As shown in FIG. 5 and FIG. 6 , a center plate part 340 is formed in a center part of the medium stacking plate 310 , and extends in a direction of arrow A (vertical to Y axis, however not always vertical to Z axis) indicating a carrying direction of the stacked recording sheets 370 ( FIG. 2 ). Guide grooves 331 , 332 , 333 , 334 are alternately formed from both sides of the center plate part 340 . The guide grooves extend in a width direction (Y axis direction) of the stacked recording sheets. An insertion part 331 a , 332 a , 333 a , 334 a is formed in each guide groove 331 - 334 . The insertion parts 331 extend outward only a predetermined width in both directions which are orthogonal each other in a position close to the center plate part 340 . All of the guide grooves 331 - 334 and the insertion parts 331 a - 334 a penetrate to the rear side of the medium stacking plate 310 as shown in FIG. 6 .
[0038] FIG. 7 is an external perspective view illustrating a configuration of a sheet guide 320 illustrated in FIG. 3 . Note that since the configuration of the sheet guide 321 herein is identical to that of the sheet guide 320 , the configuration will be explained with reference to the sheet guide 320 .
[0039] The sheet guide 320 includes a guide block 350 extending in the direction of arrow A along which the stacked recording sheets are carried, and a pair of racks 355 , 356 as a first movement restriction part extending in the width direction (Y axis direction) of the recording sheet. A restriction surface 351 as a first medium restriction part and a stacking surface 352 a are formed in the guide block 350 . The restriction surface 351 that is vertical surface with respect to Y axis, extends in the direction of arrow A, and restricts a position of the width direction of the recording sheet. The stacking surface 352 a that is orthogonal to the restriction surface 351 extends in the direction of arrow A. The edges of the width direction of the recording sheets are stacked on the stacking surface 352 a . Note that a pair of racks 355 , 356 of the sheet guide 321 corresponds to a second movement restriction part. The restriction surface 351 of the sheet guide 321 corresponds to a second medium restriction part. In this embodiment, each of the movement restriction parts is realized with two restriction members (racks 355 and 356 ). The number of the restriction members for one movement restriction part is preferably two, but may be three or more.
[0040] Rack holding members 353 , 354 respectively holding the racks 355 , 356 are formed below a plate-shaped part 352 . The upper surface of the plate-shaped part 352 is the stacking surface 352 a . The each rack 355 , 356 projects downward from the lower surface of the plate-shaped part 352 so that the upper surface of each rack 355 , 356 and the lower surface of the plate-shaped part 352 have a predetermined interval g. As shown in FIG. 7 , the racks 355 , 356 have the predetermined interval between them, and are formed at a position where the racks shifted in the direction of arrow A with respect to a width center of the guide block 350 . The position relationship of these will be explained below.
[0041] The rack 355 and the rack 356 are plate-shaped members having flat surfaces in parallel to the stacking surface 352 a . The racks 355 and the rack 356 are formed vertically with respect to the restriction surface 351 , and have a substantially identical shape, and are formed in parallel. A restriction part 355 b and a restriction part 356 b are formed in one edge of the guide block side of the rack 355 and the rack 356 . A restriction part 355 f and a restriction part 356 f are formed in the other edge of the guide block side of the rack 355 and the rack 356 . In addition, in the opposite side of arrow A of the rack 355 and the rack 356 , a tooth part 355 d and a tooth part 356 d are formed between both of the restriction parts, and in the arrow A side, a pair of bias parts 355 c , 355 e and a pair of bias parts 356 c , 356 e are formed in the neighborhood of both of the restriction parts.
[0042] As shown in FIG. 3 and FIG. 4 , the rack holding members 353 , 354 of the sheet guide 320 are installed to the medium stacking plate 310 so that the rack holding members 353 , 354 are respectively guided to the guide grooves 333 , 331 of the medium stacking plate 310 . The rack holding members 353 , 354 of the sheet guide 321 are installed to the medium stacking plate 310 so that the rack holding members 353 , 354 are respectively guided to the guide grooves 332 , 334 of the medium stacking plate 310 . Installation method of the guide grooves will be explained hereinafter.
[0043] Here, the case where the sheet guide 320 shown in FIG. 7 is installed to the medium stacking plate 310 shown in FIG. 5 and FIG. 6 will be explained. First, the sheet guide 320 is rotated substantially 90 degrees around X axis in a direction of arrow B. Respectively, a front edge of the restriction part 355 f of the rack 355 is inserted in a direction of arrow C ( FIG. 5 ) so that the front edge is substantially vertically inserted into the insertion part 333 a of the guide groove 333 of the medium stacking plate 310 . In addition, a front edge of the restriction part 356 f of the rack 356 is inserted in a direction of arrow C ( FIG. 5 ) so that the front edge is substantially vertically inserted into the insertion part 331 a of the guide groove 331 of the medium stacking plate 310 . The sheet guide 320 is pushed and entered until the plate-shaped part 352 abuts on the upper surface of the medium stacking plate 310 .
[0044] For this reason, the width of the insertion part 333 a is made to be wider than each width Wa 1 , Wa 2 of the restriction parts 355 b , 355 f . In addition, the width of the insertion part 333 a is made to be wider than each width Wb 1 , Wb 2 of the restriction parts 356 b , 356 f . Furthermore, the width of the rack holding part 353 is made to be narrower than each width Wa 1 , Wa 2 of the restriction parts 355 b , 355 f . The width of the guide groove 333 is formed to have a width suitable for guiding the inserted rack holding member 353 . In the same manner, the width of the rack holding part 354 is made to be narrower than each width Wb 1 , Wb 2 of the restriction parts 356 b , 356 f . The width of the guide groove 331 is formed to have a width suitable for guiding the inserted rack holding member 354 .
[0045] At the stage where the plate-shaped part 352 abuts on the upper surface of the medium stacking plate 310 , the sheet guide 320 is rotated around X axis in the opposite direction of a direction of arrow B. Thereby, the rack holding member 353 and the rack holding member 354 is respectively inserted into to the guide groove 333 and the guide groove 331 , and the rack 355 and the rack 356 respectively extends in parallel via the medium stacking plate 310 on the lower surface of the medium stacking plate 310 . Furthermore, until the guide block 350 is positioned at one end side of the medium stacking plate 310 , the sheet guide 320 is guided and moved by the guide grooves 333 , 331 . Thereby, the sheet guide 320 , for example, as shown in FIG. 3 , is placed at an initial position. The initial position mentioned herein indicates a farthest part position of the sheet guide 321 .
[0046] In the same manner, a front edge of the restriction part 355 f of the rack 355 of the sheet guide 321 is inserted in a direction of arrow C ( FIG. 5 ) so that the front edge is substantially vertically inserted into the insertion part 332 a of the guide groove 332 of the medium stacking plate 310 . In addition, a front edge of the restriction part 356 f of the rack 356 is inserted in a direction of arrow C ( FIG. 5 ) so that the front edge is substantially vertically inserted into the insertion part 334 a of the guide groove 334 of the medium stacking plate 310 . Until the guide block 350 is positioned at another end side of the medium stacking plate 310 , the sheet guide 321 is guided and moved by the guide grooves 332 , 334 . Thereby, the sheet guide 321 , for example, as shown in FIG. 3 , is placed at the initial position.
[0047] As shown in FIG. 4 and FIG. 6 , the guide wall 341 a and the guide wall 341 b are formed on the lower surface of the medium stacking plate 310 . The guide wall 341 a faces the bias parts 356 c , 356 e of the rack 356 of the sheet guide 320 . The guide wall 341 b faces the abutment parts 356 a , 356 g of the rack 356 of the sheet guide 320 . The abutment parts 356 a , 356 g receive bias force from the bias parts 356 c , 356 e , contact the guide wall 341 b , and guide the movement of the rack 356 of the sheet guide 320 without shaking the sheet guide. In the same manner, the guide wall 342 a and the guide wall 342 b are formed on the lower surface of the medium stacking plate 310 . The guide wall 342 a faces the bias parts 355 c , 355 e of the rack 355 of the sheet guide 320 . The guide wall 342 b faces the abutment parts 355 a , 355 g of the rack 355 of the sheet guide 320 . The abutment parts 355 a , 355 g receive bias force from the bias parts 355 c , 355 e , contact the guide wall 342 b , and guide the movement of the rack 355 of the sheet guide 320 without shaking the sheet guide. The guide walls 341 a and 341 b functions as support parts for the abutment parts 356 a and 356 g . The support parts function to allow the first and second medium restriction parts to move in predetermined directions. In the embodiments, the abutment parts 355 a , 355 g of the rack 355 contact the guide walls 341 a , 341 b , and slidably move along the surfaces of the guide walls 341 a , 341 b . As long as the support parts allows the medium restriction parts to move without shaking the sheet guide, there is no structural or material restriction for the support parts. For example, the support part may have a curved surface other than the plane surface. The support part may have a projection shape which protrudes toward the abutment part and of which a tip contacts the abutment part so that the movement of the abutment part is restricted by the tip of the support part.
[0048] In the same manner, the guide wall 344 a and the guide wall 344 b are formed on the lower surface of the medium stacking plate 310 . The guide wall 344 a faces the bias parts 356 c , 356 e of the rack 356 of the sheet guide 321 . The guide wall 344 b faces the abutment parts 356 a , 356 g of the rack 356 of the sheet guide 321 . The abutment parts 356 a , 356 g receive bias force from the bias parts 356 c , 356 e , contact the guide wall 344 b , and guide the movement of the rack 356 of the sheet guide 321 without shaking the sheet guide. In the same manner, the guide wall 343 a and the guide wall 343 b are formed on the lower surface of the medium stacking plate 310 . The guide wall 343 a faces the bias parts 355 c , 355 e of the rack 355 of the sheet guide 321 . The guide wall 343 b faces the abutment parts 355 a , 355 g of the rack 355 of the sheet guide 321 . The abutment parts 355 a , 355 g receive bias force from the bias parts 355 c , 355 e , contact the guide wall 343 b , and guide the movement of the rack 355 of the sheet guide 321 without shaking the sheet guide.
[0049] FIG. 8 is a diagram excluding the medium stacking plate 310 from the configuration diagram of FIG. 4 in the first embodiment. FIG. 9 is a K-K cross-sectional view illustrating a cross-section along a position passing a center of screws 345 , 346 illustrated in FIG. 4 .
[0050] As shown in FIG. 8 , the sheet guide 320 and the sheet guide 321 have a substantially identical shape. When the sheet guides are installed to the medium stacking plate 310 and each the sheet guide is at the initial position, in the direction of arrow A that is the moving direction of the recording sheet, the racks 355 , 356 of each sheet guide alternately are disposed in parallel at a predetermined interval. Especially, the tooth part 355 d of the sheet guide 320 is adjacent to the tooth part 356 d of the sheet guide 321 and the tooth part 356 d of the sheet guide 320 is adjacent to the tooth part 355 d of the sheet guide 321 . One part of a region of each of front edge sides of the tooth parts adjacent to each other face at a predetermined interval in the center part of the width direction (Y axis direction) of the recording sheet 370 of the medium stacking plate 310 .
[0051] As shown in FIG. 8 , the pinion gear 381 and the pinion gear 382 are respectively disposed in the center part of the width direction of the recording sheet 370 of the medium stacking plate 310 at a position where the tooth part 356 d of the sheet guide 320 and the tooth part 355 d of the sheet guide 321 face, and a position where the tooth part 355 d of the sheet guide 320 and the tooth part 356 d of the sheet guide 321 face. The pinion gear 381 and the pinion gear 382 are respectively rotatably fixed at the medium stacking plate 310 by the screw 345 and the screw 346 .
[0052] As shown in FIG. 9 , the tooth part 381 a and a flange part 381 b are formed in the pinion gear 381 . The tooth part 381 a meshes with the tooth part 356 d of the rack 356 of the sheet guide 320 and with the tooth part 355 d of the rack 355 of the sheet guide 321 . The flange part 381 b projects so as to cover each part of the rack 356 of the sheet guide 320 and the rack 355 of the sheet guide 321 . In the same manner, the tooth part 382 a and a flange part 382 b are formed in the pinion gear 382 . The tooth part 382 a meshes with the tooth part 356 d of the rack 356 of the sheet guide 321 and with the tooth part 355 d of the rack 355 of the sheet guide 320 . The flange part 382 b projects so as to cover each part of the rack 356 of the sheet guide 321 and the rack 355 of the sheet guide 320 . Note that, in FIGS. 4 , 8 , only each pitch circle (standard circle) 381 p , 382 p of each tooth part 381 a , 382 a of the pinion gear 381 , 382 are shown by dotted lines.
[0053] The plate-shaped part 352 of the guide block 350 of the sheet guide 320 installed to the medium stacking plate 310 is restricted by the medium stacking plate 310 . In addition, the racks 355 , 356 of the sheet guide 320 are restricted by each of the flange parts 381 b , 382 b of the pinion gears 381 , 382 . Accordingly, the sheet guide 320 is not detached below (here, the minus side of Z axis). In addition, since the widths of the racks 355 , 356 are respectively formed wider than the widths of the guide grooves 331 , 333 of the medium stacking plate 310 . Accordingly, the sheet guide 320 is not detached above (here, plus side of Z axis). In the same manner, the sheet guide 321 installed to the medium stacking plate 310 is configured so as not to detach in upper and lower directions with respect to the medium stacking plate 310 .
[0054] Note that, as shown in FIG. 9 , a wave washer 383 is arranged in a compressed manner between the pinion gear 382 and the medium stacking plate 310 , and biases the pinion gear 382 toward the screw 346 . This wave washer 383 adjusts a rotation load of the pinion gear 382 , and thereby, adjusts the movement load of the sheet guides 320 , 321 . The wave washer 383 may respectively be provided to the two pinion gears 381 , 382 . However, here, as described below since two of the pinion gears 381 and 382 link each other, the wave washer 383 may provided only to the pinion gear 382 .
[0055] As shown in FIG. 4 (see FIG. 8 ), the abutment parts 356 a , 356 g of the sheet guide 320 contact the guide wall 341 b of the medium stacking plate 310 by bias from the bias parts 356 c , 356 e , and restrict an mesh position of the pinion gear 381 and the rack 356 as well as a movement range of the sheet guide 320 with respect to the medium stacking plate 310 . In the same manner, the abutment parts 355 a , 355 g of the sheet guide 320 contact the guide wall 342 b of the medium stacking plate 310 by bias from the bias parts 355 c , 355 e , and restrict an mesh position of the pinion gear 382 and the rack 355 as well as a movement range of the sheet guide 320 against the medium stacking plate 310 .
[0056] Meanwhile, the abutment parts 356 a , 356 g of the sheet guide 321 contact the guide wall 344 b of the medium stacking plate 310 by bias from the bias parts 356 c , 356 e , and restrict an mesh position of the pinion gear 382 and the rack 356 as well as a movement range of the sheet guide 321 with respect to the medium stacking plate 310 . In the same manner, the abutment parts 355 a , 355 g of the sheet guide 321 contact the guide wall 343 b of the medium stacking plate 310 by bias from the bias parts 355 c , 355 e , and restrict an mesh position of the pinion gear 381 and the rack 355 as well as a movement range of the sheet guide 321 against the medium stacking plate 310 .
[0057] FIG. 10 is a size explanation diagram illustrating a position relationship between the sheet guides 320 , 321 installed to the medium stacking plate 310 and the pinion gears 381 , 382 rotatably axially fixed to the medium stacking plate 310 . Note that, here, for the sake of convenience, “′” are putted to the reference numbers of each configuration element of the sheet guide 321 , to distinguish each configuration element of the sheet guide 320 . Note that FIG. 10 corresponds to FIG. 8 the medium stacking device 302 viewed from the lower side (the minus side of Z axis), and the direction of arrow A in FIG. 10 shows the carrying direction of the stacked recording sheet.
[0058] As shown in the above figure, the sheet guides 320 , 321 have the same identical figure. Restriction surfaces 351 , 351 ′ face each other and extend in the direction of arrow A. And the racks 355 , 356 of the sheet guide 320 and the racks 355 ′, 356 ′ of the sheet guide 321 are disposed so as to be alternately positioned in the direction of arrow A. Furthermore, the pinion gear 381 is disposed so as to mesh with each of the racks between the rack 356 of the sheet guide 320 and the rack 355 ′ of the sheet guide 321 extending each other in parallel. The pinion gear 382 is disposed so as to mesh with each of the racks between the rack 355 of the sheet guide 320 and the rack 356 ′ of the sheet guide 321 .
[0059] A length in the direction of arrow A of the guide block 350 ( 350 ′) is defined as L. A diameter of each pitch circle (standard circle) 381 p , 382 p of each pinion gear 381 , 382 disposed in line in direction of arrow A is defined as d. A position relationship between the rack 355 ( 355 ′) and the rack 356 ( 356 ′) extending in parallel to the rack 355 will be explained.
[0060] A hypothetical center line being the perpendicular bisector between each of rotation centers 381 c , 382 c of the pinion gears 381 , 382 and extending in a width direction (Y axis direction) of the stacked recording sheet is defined as P. A distance from the hypothetical center line P to the rotation center 381 c is defined as X. A distance from the hypothetical center line P to the rotation center 382 c is defined as X.
[0061] At this time, a distance from the hypothetical center line P to a pitch line (standard line) 355 p ′ of the rack 355 ′ being an engagement position of the pinion gear 381 is defined as Z. The distance Z is obtained by the following Formula:
[0000] Z=X−d/ 2.
[0000] The tooth part 355 d ( FIG. 8 ) is formed so that this position is a pitch line (standard line) 355 p ′ of the rack 355 ′. In addition, a distance from the pitch line (standard line) 355 p ′ of the rack 355 ′ to a pitch line (standard line) 356 p ′ of the rack 356 ′ being the engagement position with the pinion gear 382 is defined as Y. The distance Y is obtained by the following Formula:
[0000] Y= 2 X.
[0000] The tooth part 356 d ( FIG. 8 ) is formed so that this position is a pitch line (standard line) 356 p ′ of the rack 356 ′.
[0062] In addition, with respect to the restriction surface 351 ′ having the length L in the direction of arrow A, the substantially center in the direction of arrow A of the restriction surface 351 ′ is disposed so as to coincide with the hypothetical central line P, and at least one of the racks 355 ′, 356 ′ is disposed in the direction of arrow A side (downstream side) and the opposite side of the direction of arrow A side (upstream side) based on the substantially center. Note that, in the drawing, rack 355 ′ on the downstream side, rack 356 ′ on the upstream side. In this case, obviously shown in the arrangement in FIG. 10 , when a width of the rack 355 ′ is defined as w 1 , and a width of the rack 356 ′ is defined as w 2 , Z and K are necessary to be set by the following formulae:
[0000] Z>w 1, and
[0000] K=L/ 2−( Z+d )> w 2.
[0063] By forming in this manner, the sheet guide 320 and the sheet guide 321 having the same shape can be disposed and face each other, can be installed to the medium stacking plate 310 .
[0064] Note that, here, the substantially center in the direction of arrow A of the restriction surface 351 ′ is disposed so as to coincide with the hypothetical central line P. However, if the substantially center mentioned herein indicates the hypothetical center line P being included in a region having a length of L/2±20%, same effects can be obtained by the arrangement of the line P.
[0065] In addition, the engagement position mentioned herein is a position where the pinion gear 381 meshes with the racks 355 ′, 356 , and the pinion gear 382 meshes with the racks 355 , 356 ′. FIGS. 11A and 11B are partially enlarged diagrams for explaining an engagement position with a mesh of the pinion gear 381 and the rack 355 ′ as an example.
[0066] As shown in FIG. 11A , the pinion gear 381 and the rack 355 ′ are engaged so that one of tangential lines of the pitch circle (standard circle) 381 p of the pinion gear 381 is positioned in the substantially center of a range h 2 from an addendum to a dedendum of the tooth part 355 d ′ of the rack 355 ′. A position on the rack 355 ′ where the pitch circle (standard circle) 381 p of the pinion gear 381 contacts in this way corresponds to the pitch line (standard line) 355 p ′ of the rack. Accordingly, the engagement position mentioned herein corresponds to a position where the pitch circle (standard circle) of the pinion gear contacts the pitch line (standard line) of the rack.
[0067] The above mentioned engagement position is merely one example. The engagement position may be a position in a region where a range h 1 and the range h 2 intersect. The range h 1 is from the addendum to the dedendum of the tooth part 381 a of the pinion gear 381 . The range h 2 is from the addendum to the dedendum of the tooth part 355 d ′ of the rack 355 ′. For example, as shown in FIG. 11B , in a case where the pinion gear 381 is shifted, a position relationship causing the pinion gear 325 to engage with the rack 355 ′ differs from that shown in FIG. 11A . The engagement position of the other pinion gear with the rack is identical to the above mentioned engagement position.
[0068] In addition, for example, the tooth part 355 d of the rack 355 and the tooth part 356 d of the rack 356 have the identical pitch and the identical phase viewed from the restriction surface 351 in the sheet guide 320 shown in FIG. 7 . The sheet guide 321 is configured in the same manner as mentioned above. In addition, for example, the pinion gear 381 and the pinion gear 382 shown in FIG. 8 , have the identical number of teeth, and as shown in FIG. 11 , the number herein is 16, which is even number. Furthermore, the pinion gears respectively include the flange parts 381 b , 382 b , and have the identical module.
[0069] In the above mentioned configuration, operation of the sheet guides 320 , 321 in the medium stacking device 302 of the manual feed tray 300 will be explained with reference to FIG. 12 . Note that FIG. 12 is a diagram used to an operation explanation of the sheet guides 320 , 321 of the medium stacking device 302 stacking recording sheets 370 . In the above figure, only a region in the recording sheet 370 where the medium stacking device exists is specified by drawing with diagonal lines.
[0070] Firstly, the medium stacking device 302 is pushed down against bias of the spring 309 by an operation device (not shown), so that the contact part 311 of the medium stacking device 302 shown in FIG. 2 is separated only at a predetermined interval from the pickup roller 303 , and the medium stacking device 302 is restricted at the position where the medium stacking device 302 is pushed down. In the state where the medium stacking device 302 is pushed down in this way, the recording sheets 370 are placed on the manual feed tray 300 . At this time, the sheet guide 320 and the sheet guide 321 are moved to outside and the recording sheets 370 are stacked on the medium stacking device 302 so that the width direction edges of the recording sheet 370 are positioned on each of the stacking surfaces 352 a of the sheet guide 320 and the sheet guide 321 . Each of the restriction surfaces 351 of the sheet guides 320 and 321 are moved in a center direction until the restriction surfaces 351 abut on end surfaces of the recording sheets 370 .
[0071] At this time, each of the restriction surfaces 351 of the sheet guide 320 and the sheet guide 321 are symmetrically moved away from and toward a line connecting each of the rotate center s of the pinion gears 381 and 382 (see FIG. 8 ) as the center line. Accordingly, when the guide block 350 of either the sheet guide 320 or sheet guide 321 is moved, the other guide block 350 is also symmetrically moved via the pinion gears. Thereby, the width direction position of the recording sheet 370 can be restricted.
[0072] As mentioned above, since the tooth part 355 d of the rack 355 and the tooth part 356 d of the rack 356 are configured to have the identical pitch and the identical phase viewed from the restriction surface 351 , and the pinion gear 381 and the pinion gear 382 have the identical shape, even if a rack and pinion is configured with the two racks 355 , 356 in this way, sliding motion can be smoothly performed.
[0073] After determination of a position of the width direction of the recording sheet 370 on the medium stacking device 302 is performed as mentioned above, position restriction by an operation device (not shown) is unlocked, and as shown in FIG. 2 , the top sheet of the stacked recording sheets 370 contacts the pickup roller 303 by bias force of the spring 309 . In such a state, the pickup roller 303 activates and the recording sheet 370 is fed, the recording sheet 370 is fed in the direction of arrow A in FIG. 12 . At this time, the recording sheet 370 may skew in a rotation direction of either arrow Ma or arrow Mb.
[0074] For example, when the recording sheet 370 skews in the direction of arrow Ma, the rear edge side in the direction of arrow A of the restriction surface 351 of the sheet guide 321 receives a pressure force Fa from the recording sheet 370 generated by skew, and the front edge side in the direction of arrow A of the restriction surface 351 of the sheet guide 320 receives a pressure force Fc from the recording sheet 370 generated by skew. At this time, a movement force Fd is generated at the front edge side of the sheet guide 321 toward the center direction to rotate in the direction of arrow Mc, a movement force Fb is generated at the rear edge side of the sheet guide 320 toward the center direction to rotate in the direction of arrow Md.
[0075] At this time, the movement force Fd, which is generated at the front edge side of the sheet guide 321 , is led to the front edge side of the sheet guide 320 via the rack 355 ′ of the sheet guide 321 , the pinion gear 381 , the rack 356 of the sheet guide 320 shown in FIG. 10 , and reaches the front edge side of the sheet guide 320 as a force cancelling the pressure force Fc from the recording sheet 370 . In the same manner, the movement force Fb, which is generated at the rear edge side of the sheet guide 320 , is led to the rear edge side of the sheet guide 321 via the rack 355 of the sheet guide 320 , the pinion gear 382 , the rack 356 ′ of the sheet guide 321 shown in FIG. 10 , and reaches the rear edge side of the sheet guide 320 as a force cancelling the pressure force Fa from the recording sheet 370 .
[0076] In a case where the recording sheet 370 skews in the direction of arrow Mb, in the same manner, a pressure force which each sheet guide 320 , 321 respectively receives from the recording sheet 370 is cancelled.
[0077] As mentioned above, according to the medium stacking device of the embodiment, since the pinion gears 381 , 382 arranged at the positions being separated in the direction of arrow A respectively link to the racks extending from the sheet guides 320 , 321 , even if skew is generated in the carried recording sheet, an incline of the sheet guides 320 , 321 is suppressed, and the skew of the recording sheet can be diminished.
Second Embodiment
[0078] FIG. 13 is a configuration diagram viewed from the lower side (the minus side of Z axis) of the medium stacking device 402 in the second embodiment according to the present invention. FIG. 14 is an M-M cross-sectional view illustrating a cross-section along a position passing a center of screws 345 , 346 shown in FIG. 13 . The upper side of the medium stacking device 402 is placed up in FIG. 4 .
[0079] The image forming apparatus employing this medium stacking device 402 has main different points from the image forming apparatus employing the above mentioned medium stacking device 302 of the first embodiment shown in FIG. 4 . The points are that, for example, upper layer gears 481 d , 482 d are added to the pinion gears 481 , 482 ( 381 , 382 in embodiment 1) and the pinion gears are formed as a two stage gear, and that an idler gear 400 meshing with these upper gears 481 d , 482 d is added. In the invention, a transferring part means a part that functions to convey a power from the first gear part to the second gear part. In this embodiment, the transferring part is configured with the upper layer gears 481 d , 482 d and idler gear 400 . As long as the transferring part is able to convey the power from the first gear part to the second gear part, there is no structural restriction. The number of parts, gears for the transferring part vary according to the configuration. Instead of the mechanical structure by gears discussed above, friction force or magnetic force may be useful to realized the transferring part.
[0080] Accordingly, the same reference numbers are put to, and explanation and figures are omitted for parts of the image forming apparatus employing this medium stacking device 402 that are common with the image forming apparatus 1 of the first embodiment mentioned above ( FIG. 1 ). Different parts of the image forming apparatus from those of the image forming apparatus 1 are intensively explained. Note that since the main configuration of the image forming apparatus of the embodiment is common with the main configuration of the image forming apparatus 1 of the first embodiment shown in FIG. 1 other than the medium stacking device 402 , FIGS. 1 , 2 will be referred if needed.
[0081] In FIG. 13 and FIG. 14 , in the pinion gears 481 , 482 , not only the first stage gear meshing with each rack, as explained in the first embodiment, but also the upper layer gears 481 d , 482 d being a second stage gear are formed via flange parts 481 b , 482 b . In FIG. 13 , pitch circles of the upper layer gears 481 d , 482 d are shown. The idler gear 400 is disposed in the center part of these pinion gears 481 , 482 , and is rotatably fixed in the center point between axes of the pinion gears 481 , 482 by a screw 401 to medium stacking plate 310 . In FIG. 13 , a pitch circle 400 p of the idler gear 400 is shown by dotted lines.
[0082] As shown in FIG. 14 , a wave washer 405 is arranged in a compressed manner between the idler gear 400 and the medium stacking plate 310 and, biases the idler gear 400 toward the screw 401 . Note that a notch part 455 h for allowing attachment of the idler gear 400 to the medium stacking plate 310 is formed in a rack 455 ( 355 in the first embodiment) of the sheet guides 420 , 421 ( 320 , 321 the first embodiment).
[0083] The idler gear 400 respectively meshes with each upper layer gear 481 d , 482 d of these pinion gears 481 , 482 at the center parts of the pinion gears 481 , 482 and causes the pinion gear 481 to link to the pinion gear 482 .
[0084] Note that, here, the sheet guide 420 corresponds to a first movement part. The sheet guide 421 corresponds to a second movement part. The pair of racks 455 , 456 of the sheet guide 420 corresponds to a first movement restriction part. The pair of racks 455 , 456 of the sheet guide 421 corresponds to a second movement restriction part. The restriction surface 351 of the sheet guide 420 corresponds to a first medium restriction part. The restriction surface 351 of the sheet guide 421 corresponds to a second medium restriction part.
[0085] In the above mentioned configuration, operation of the sheet guide 420 , 421 in the medium stacking device 402 of will be explained with reference to FIG. 15 . Note that FIG. 15 is a diagram used to an operation explanation of the sheet guides 420 , 421 of the medium stacking device 402 stacking the recording sheets 370 . In the above figure, only a region in the recording sheet 370 where the medium stacking device exists is specified by drawing with diagonal lines.
[0086] Firstly, the medium stacking device 402 is pushed down against bias of the spring 309 by an operation device (not shown), so that the contact part 311 of the medium stacking device 302 shown in FIG. 2 (herein referred to as 402 ) is separated only at a predetermined interval from the pickup roller 303 , and the medium stacking device 402 is restricted at the position where the medium stacking device 402 is pushed down. In the state where the medium stacking device 402 is pushed down in this way, the recording sheets 370 are placed on the manual feed tray 300 . At this time, the sheet guide 420 and the sheet guide 421 are moved to outside and the recording sheets 370 are stacked on the medium stacking device 402 so that the width direction edges of the recording sheet 370 are positioned on each of the stacking surfaces 352 a of the sheet guide 420 and the sheet guide 421 . Each of the restriction surfaces 351 of the sheet guides 420 and 421 are moved in a center direction until the restriction surfaces 351 abut on end surfaces of the recording sheets 370 .
[0087] At this time, each of the restriction surfaces 351 of the sheet guide 420 and the sheet guide 421 are symmetrically moved away from and toward and a line connecting each of the rotate centers of the pinion gears 481 and 482 (see FIG. 13 ) as the center line. At this time, the pinion gear 481 and the pinion gear 482 simultaneously rotate in the identical direction with the movement of the sheet guide 420 and the sheet guide 421 , while the idler gear 400 links these gears rotating in the opposite direction. As mentioned above, in the case where the idler gear 400 is added, even the two racks 455 , 456 are used to configure the rack and pinion, sliding motion can be smoothly performed.
[0088] Thereby, after determination of a position of the width direction of the recording sheet 370 on the medium stacking device 402 is performed as mentioned above, position restriction by an operation device (not shown) is unlocked and as shown in FIG. 2 , the top sheet of the stacked recording sheets 370 contacts the pickup roller 303 by bias force of the spring 309 . In such a state, the pickup roller 303 activates and the recording sheet 370 is fed, the recording sheet 370 is fed in the direction of arrow A in FIG. 15 . At this time, the recording sheet 370 may skew in a rotation direction of either arrow Ma or arrow Mb.
[0089] For example, when the recording sheet 370 skews in the direction of arrow Ma, the rear edge side in the direction of arrow A of the restriction surface 351 of the sheet guide 421 receives the pressure force Fa from the recording sheet 370 generated by skew. At this time, the front edge side of the sheet guide 420 generates the movement force Fd toward the center direction to rotate in the direction of arrow Mc.
[0090] These forces generated by skew toward the direction of arrow Ma cause the pinion gear 481 and the pinion gear 482 ( FIG. 13 ) to rotate in the opposite direction each other. However, these pinion gear 481 and pinion gear 482 linked by the idler gear 400 cannot rotate in the opposite direction each other. Accordingly, the sheet guide 421 does not rotate in the direction of arrow Ma. In the same manner, in a case where the recording sheet 370 skews toward the direction of arrow Mb, the sheet guide 421 does not rotate in direction of arrow Mb. Since the forces act with respect to the sheet guide 420 in the same manner, the sheet guide 420 and the sheet guide 421 can always keep the respective restriction surfaces 351 in parallel with respect to the direction of arrow A being the sheet carrying direction.
[0091] As mentioned above, according to the medium stacking device of the embodiment, since the pinion gears 481 , 482 arranged at the positions being separated in the direction of arrow A link to the idler gear 400 , even if skew is generated in the carried recording sheet, thereby, since an incline of the sheet guides 420 , 421 is suppressed, and the skew of the recording sheet can be diminished.
Third Embodiment
[0092] FIG. 16 is a configuration diagram of the medium stacking device 502 viewed from the lower side (the minus side of Z axis) in the third embodiment according to the present invention. FIG. 17 is an external perspective view illustrating a configuration of a sheet guide 520 ( 521 ).
[0093] The image forming apparatus employing this medium stacking device 502 has a main different point from the image forming apparatus employing the above mentioned medium stacking device 302 of the first embodiment shown in FIG. 4 . The point is that instead of the pinion gears 381 , 382 , the flanges 581 , 582 without a gear are fixed by the screws 345 , 346 to the medium stacking plate 310 , and plate-shaped extending parts 555 , 556 are formed instead of the racks in each sheet guide 520 , 521 . In this embodiment, the movement restriction parts are realized with two restriction members (extending parts 555 and 556 ). The number of the restriction members for one movement restriction part is preferably two, but may be three or more.
[0094] Accordingly, the same reference numbers are put to, and explanation and figures are omitted for parts of the image forming apparatus employing this medium stacking device 502 that are common with the image forming apparatus 1 of the first embodiment mentioned above ( FIG. 1 ). Different parts of the image forming apparatus from those of the image forming apparatus 1 are intensively explained. Note that since the main configuration of the image forming apparatus of the embodiment is common with the main configuration of the image forming apparatus 1 of the first embodiment shown in FIG. 1 other than the medium stacking device 502 , FIGS. 1 , 2 will be referred if needed.
[0095] The extending part 555 of the sheet guide 520 is formed to have a width forming a necessary minimum gap to guide and smoothly slide a side part 555 b and a side part 555 a . The side part 555 b is guided by the guide wall 342 a formed in the medium stack plate 310 and the side part 555 a is guided by the guide wall 342 b formed in the medium stack plate 310 . In the same manner, the extending part 556 of the sheet guide 520 is formed to have a width forming a necessary minimum gap to guide and smoothly slide a side part 556 b and a side part 556 a . The side part 556 b is guided by the guide wall 341 a formed in the medium stack plate 310 and the side part 556 a is guided by the guide wall 341 b formed in the medium stack plate 310 .
[0096] Note that, here, the side parts 555 a , 555 b of the extending part 555 and the side parts 556 a , 556 b of the extending part 556 correspond to an abutment part. The guide walls 341 a , 341 b , 342 a , and 342 b correspond to support parts.
[0097] In addition, the extending part 555 of the sheet guide 521 is formed to have a width forming a necessary minimum gap to guide and smoothly slide a side part 555 b and a side part 555 a . The side part 555 b is guided by the guide wall 342 a formed in the medium stack plate 310 and the side part 555 a is guided by the guide wall 343 b formed in the medium stack plate 310 . In the same manner, the extending part 556 of the sheet guide 521 is formed to have a width forming a necessary minimum gap to guide and smoothly slide a side part 556 b and a side part 556 a . The side part 556 b is guided by the guide wall 344 a formed in the medium stack plate 310 and the side part 556 a is guided by the guide wall 344 b formed in the medium stack plate 310 .
[0098] The flange 581 restricts detachment of the extending part 556 of the sheet guide 520 and the extending part 555 of the sheet guide 521 below (here, the minus side of Z axis. The flange 582 restricts detachment of the extending part 555 of the sheet guide 520 and the extending part 556 of the sheet guide 521 below (here, the minus side of Z axis). Accordingly, the respective sheet guide 520 and the sheet guide 521 herein individually move without linking each other.
[0099] Note that, here, the sheet guide 520 corresponds to a first movement part. The sheet guide 521 corresponds to a second movement part. The pair of extending parts 555 , 556 of the sheet guide 520 corresponds to a first movement restriction part. The pair of racks 555 , 556 of the sheet guide 521 corresponds to a second movement restriction part. The restriction surface 351 of the sheet guide 520 corresponds to a first medium restriction part. The restriction surface 351 of the sheet guide 521 corresponds to a second medium restriction part.
[0100] In the above mentioned configuration, operation of the sheet guides 520 , 521 in the medium stacking device 502 will be explained.
[0101] Firstly, the medium stacking device 502 is pushed down against bias of the spring 309 by an operation device (not shown), so that the contact part 311 of the medium stacking device 302 shown in FIG. 2 (herein referred to as 502 ) is separated only at a predetermined interval from the pickup roller 303 , and the medium stacking device 502 is restricted at the position where the medium stacking device 502 is pushed down. In the state where the medium stacking device 502 is pushed down in this way, the recording sheets 370 are placed on the manual feed tray. At this time, the sheet guide 520 and the sheet guide 521 are moved to outside and the recording sheets 370 are stacked on the medium stacking device 502 so that the width direction edges of the recording sheet 370 are positioned on each of the stacking surfaces 352 a of the sheet guide 520 and the sheet guide 521 . Each of the restriction surfaces 351 of the sheet guides 520 and 521 are moved in a center direction until the restriction surfaces 351 abut on end surfaces of the recording sheets 370 .
[0102] At this time, since the sheet guide 520 and the sheet guide 521 do not link each other, they need to be individually moved by a user.
[0103] After determination of a position of the width direction of the recording sheet 370 on the medium stacking device 502 is performed as mentioned above, position restriction by an operation device (not shown) is unlocked and as shown in FIG. 2 , the top sheet of the stacked recording sheets 370 contacts the pickup roller 303 by bias force of the spring 309 . In such a state, the pickup roller 303 activates and the recording sheet 370 is fed, the recording sheet 370 is fed in the direction of arrow A in FIG. 12 .
[0104] At this time, in the case where skew generates in the recording sheet 370 and a pressure force acts on the restriction surface 351 , since a farthest side part of an extending part from a point of action of force contacts the guide wall of the medium stacking plate 310 , skew can be reduced in comparison with the case where only one extending part having similar dimension accuracy is used.
[0105] For example, in the case where the sheet leading side (direction of arrow A side) of the restriction surface 351 of the sheet guide 520 shown in FIG. 17 is pressed by a pressure force Fc 1 due to skew of the recording sheet stacked on the medium stacking device 502 , a front edge 555 h of the side part 555 b of the extending part 555 contacts the guide wall 342 a ( FIG. 16 ) of the medium stacking plate 310 , thereby, an incline of the sheet guide 520 with respect to the direction of arrow A can be restricted.
[0106] In the same manner, in the case where the sheet trailing side (opposite side of direction of arrow A side) of the restriction surface 351 of the sheet guide 520 shown in FIG. 17 is pressed by a pressure force Fc 2 due to skew of the recording sheet stacked on the medium stacking device 502 , a front edge 556 h of the side part 556 a of the extending part 556 contacts the guide wall 341 b ( FIG. 16 ) of the medium stacking plate 310 , thereby, an incline of the sheet guide 520 with respect to the direction of arrow A can be restricted. Such a mechanism of prevention of rotation of the sheet guide 521 disposed so as to face the sheet guide 520 is similar to the above mentioned mechanism.
[0107] As mentioned above, according to the medium stacking device of the embodiment, even if skew is generated in the carried recording sheet, thereby, since an incline of the sheet guides 520 , 521 is suppressed with respect to the sheet carrying direction (the direction of arrow A), and the skew of the recording sheet can be diminished. Furthermore, according to the explanation on FIG. 10 of the first embodiment mentioned above, respectively, one of the extending part 556 and the extending part 555 is disposed in the direction of arrow A side and the other is disposed in the opposite side of the direction of arrow A side based on the center in the direction of arrow A of the restriction surface 351 . Thereby, the above mentioned effects of the embodiment can be more efficiently obtained regardless of directions of skew.
[0108] Note, in the embodiment, the sheet guide to which the two extending parts are provided is shown as an example. However, same effects can be obtained by a sheet guide having two or more extending parts.
Fourth Embodiment
[0109] FIG. 18 is an external perspective view illustrating a configuration of a sheet guide 620 ( 621 ) in the fourth embodiment.
[0110] A medium stacking device employing the sheet guide 620 ( 621 ) has a main different point from the image forming apparatus employing the above mentioned medium stacking device 502 of third embodiment shown in FIG. 16 . The point is that extending parts 655 , 656 ( 555 , 556 in the third embodiment) have a different shape from that of the extending parts 555 , 556 . Accordingly, the same reference numbers are put to, and explanation and figures are omitted for parts of the image forming apparatus employing these sheet guides 620 ( 621 ) that are common with the image forming apparatus 1 of the first embodiment mentioned above ( FIG. 1 ). Different parts of the image forming apparatus from those of the image forming apparatus 1 are intensively explained. Note that since the main configuration of the image forming apparatus of the embodiment is common with the main configuration of image forming apparatus 1 of the first embodiment shown in FIG. 1 other than the medium stacking device, FIGS. 1 , 2 will be referred if needed. In this embodiment, the movement restriction parts are realized with two restriction members (extending parts 655 and 656 ). The number of the restriction members for one movement restriction part is preferably two, but may be three or more.
[0111] A shape of the extending part 655 , 656 of the sheet guide 620 ( 621 ) corresponds to a shape of the rack 355 , 356 of the sheet guide 320 ( 321 ) shown in FIG. 7 explained in first embodiment other than the tooth parts 355 d , 356 d . Accordingly, when this sheet guide 620 ( 621 ) is installed to the medium stacking plate 310 , in FIG. 16 explained in the third embodiment, instead of the side parts 555 b , 556 b of respective extending parts 555 , 556 , like the bias parts 355 c , 355 e and the bias parts 365 c , 365 e in FIG. 4 , the bias parts 655 c , 655 e of the sheet guide 620 face and press the guide wall 342 a ; the bias parts 656 c , 656 e of the sheet guide 620 face and press the guide wall 341 a ; the bias parts 655 c , 655 e of the sheet guide 621 face and press the guide wall 343 a ; and the bias parts 656 c , 656 e of the sheet guide 621 face and press the guide wall 344 a.
[0112] In the above mentioned configuration, since method of setting recording sheets on the medium stacking device is identical to that of the above mentioned third embodiment, the explanation of the method will be herein omitted.
[0113] When a set recording sheet is carried in the direction of arrow A, for example, in a case where a sheet leading side (side of direction of arrow A) of the restriction surface 351 of the sheet guide 621 shown in FIG. 18 is pressed by the pressure force Fc 1 due to skew of the recording sheet stacked on the medium stacking device, since forces are respectively led to a direction where the bias part 655 e presses the guide wall 342 a and the bias part 656 e presses the guide wall 341 a , a restrative force Fa 4 generated from the bias part 655 e and a restrative force Fa 2 generated from the bias part 656 e respectively resist these forces. Thereby, an incline of the sheet guide 620 with respect to the direction of arrow A can be restricted.
[0114] In the same manner, in a case where a sheet trailing side (opposite side of direction of arrow A) of the restriction surface 351 of the sheet guide 620 shown in FIG. 18 is pressed by the pressure force Fc 2 due to skew of the recording sheet stacked on the medium stacking device, since the front edge part 656 h of the side part 656 a of the extending part 656 functions as a fulcrum, forces are respectively led to a direction where the bias part 655 c presses the guide wall 342 a and the bias part 656 c presses the guide wall 341 a , a restrative force Fa 3 generated from the bias part 655 c and a restrative force Fa 1 generated from the bias part 656 c respectively resist these forces. Thereby, an incline of the sheet guide 620 with respect to the direction of arrow A can be restricted. Such a mechanism of prevention of incline of the sheet guide 621 disposed so as to face the sheet guide 620 is similar to the above mentioned mechanism.
[0115] As mentioned above, according to the medium stacking device of the embodiment, even if skew is generated in the carried recording sheet, thereby, since an incline of the sheet guide 620 , 621 is suppressed with respect to the sheet carrying direction (the direction of arrow A), and the skew of the recording sheet can be diminished. Furthermore, according to the explanation on FIG. 10 of the first embodiment mentioned above, respectively, one of the extending part 656 and the extending part 655 is disposed in the direction of arrow A side and the other is disposed in the opposite side of the direction of arrow A side based on the center of the restriction surface 351 in the direction of arrow A. Thereby, the above mentioned effects of the embodiment can be more efficiently obtained regardless of directions of skew.
[0116] Note, in the embodiment, the sheet guide to which the two extending parts are provided is shown as an example. However, same effects can be obtained by a sheet guide having two or more extending parts.
[0117] Through the specification, a pair of racks ( 355 , 356 ), a pair of extending parts ( 555 , 556 ), and another pair of extending parts ( 655 and 656 ) are disclosed as the restriction members for the movement restriction parts. However, the restriction members are not necessarily only two components, but may be three or more components which function to regulate the movement of the sheet guide.
[0118] In the above mentioned embodiments, applications of the present invention to an electrographic printer are explained. However, the present invention is not limited to the embodiments and may be applied to a multifunction printer (MFP), a facsimile device, a photocopy machine, and the like. In addition, in the above mentioned embodiments, applications of the present invention to manual feed trays are explained. However, the present invention may be applied to a cassette tray, an Auto Document Feeder (ADF), and the like. | A medium stacking device includes a medium stacking part stacking a medium, and a first movement part movably provided with respect to the medium stacking part. The first movement part has a first medium restriction part restricting a position of the medium, and a first movement restriction parts including a plurality of restriction members, each of which engaging with the medium stacking part and restricting a direction of the movement of the first movement part. | 1 |
FIELD OF THE INVENTION
The present invention relates to retort systems for in-container preservation of foodstuffs, and more particularly, to retort systems that use spray water to aid in the distribution and mixing of steam and air within a sealed vessel.
BACKGROUND OF THE INVENTION
Overpressure retorts are used for the in-container preservation of foodstuffs, either for pasteurization or sterilization processes. In general, these machines use a combination of pressure and temperature to sterilize packaged food according to a predefined schedule. Their popularity has increased in the past few years because of the development of processes that allow for the use of media other than only saturated steam. Using other fluids enables the application of an additional partial overpressure on top of the basic steam vapor pressure associated with the process temperature. Such additional overpressure is useful in coping with new types of containers that are being introduced on the market.
The additional overpressure is usually achieved by adding air to the interior of the retort vessel. As air has poor heat transfer properties, the mixture of steam and air has to be assisted for good heat transfer to the containers and their content. This can be accomplished in any number of ways. In steam-air retorts, the mixture is recirculated through the retort load by means of fans. In full immersion retorts, the load is immersed in water. In trickling water type retorts, water is trickled from the top of the retort to the bottom, passing through the load in-between. In spray water retorts, water is sprayed from the top (and optionally also from the sides) of the container through the load. The latter type can make use of external means to heat the water or alternatively can have direct steam injection into the vessel.
FIG. 1 illustrates a recirculation system in a known spray water retort. A cylindrical pressure vessel 10 houses a load 12 , a header 14 , and various spray nozzles 16 . The load is supported on a horizontal pallet (not shown). Distribution pipes 18 extend the longitudinal length of the vessel. Using the various spray nozzles 16 , the distribution pipes 18 direct process water into the vessel and onto the load. The header 14 is positioned at select locations needed to support the distribution network (e.g., in the middle of the vessel). Use of side spray nozzles 20 is optional, depending on the type of load being processed. In general, the spray pattern shown provides a good distribution of process water through the load. The process water is collected in a lower sump 22 , passed through a strainer 24 , and recirculated through the system via a recirculation pump 26 . The recycled process water is passed through piping 28 and one or more filters 30 and then reintroduced to the distribution pipes. Control valves 32 regulate the recirculation process.
Referring to FIG. 2 , the nozzles used have a solid cone spray characteristic, with a cone angle β of approximately 75 degrees. This angle can vary slightly, depending on the pressure of the fluid in the distribution pipes. In one arrangement, this pressure is on the order of 1 bar overpressure. The distance D between the nozzles and the load in prior art arrangements is generally in the range of about 70 mm to about 200 mm. The distance is chosen so that the spray water flowing through the load provides a good temperature distribution. The load may be baskets (which are typically used for cans and jars) or stacks of trays (which are typically used for containers that are not rigid enough to allow stacking on top of each other, e.g., plastic lunch bowls and pouches).
During use, the load is subjected to a preservation phase having a predefined temperature schedule and a predefined pressure schedule. The temperature distribution is important within each individual basket or stack, and also between the different baskets or stacks placed along the length of the retort. The fluid flow per nozzle and the number of nozzles in the retort system determine the total flow of process water being continuously recirculated over and through the load. From experience it was found that satisfactory temperature distributions are achieved with a flow capacity per processing position (i.e., a basket or stack) of approximately 30 m 3 /hr per cubic meter load for static processing retorts, and, 40 m 3 /hr for agitation processing retorts. A typical flow per nozzle is in the order of 17 liters/min. In some arrangements, the recirculation system is also used for cooling the load after completion of the preservation phase.
Recently, a new type of paperboard package has been introduced for use with various types of foodstuffs. These packages are generally composed of a coated paperboard folded into a rectilinear shape. Currently, fluids such as juices, soups, soy milk, etc. are packaged in these kinds of containers. The packages have some degree of protective coatings on their surfaces, but, in general, are susceptible to fluid absorption along their exposed edges. The edges typically do not receive coatings due to manufacturing cost considerations. The amount of absorption that may occur is a factor in determining the package quality. If there is too much absorption, the package will be considered defective.
The spray water retort process described above has been found to cause excessive fluid absorption in some paperboard packages. Thus, a need exists for an improved retort system that reduces the amount of absorption and thereby reduces the number of defective packages. The present invention is directed to fulfilling these needs and others as described below.
SUMMARY OF THE INVENTION
In accordance with teachings of the present invention, a retort system is described that uses one or more solid cone spray nozzles with spray angles in the range of about 100 degrees to about 115 degrees. Multiple embodiments are described that alter other aspects of the retort process in order to adjust to the wide angle nozzles and reduce moisture absorption in a paperboard container during processing of foodstuffs therein.
In one embodiment, the distance between the nozzles and the container is in the range of about 70 mm to about 200 mm. In another embodiment, the flow rate if each nozzle is reduced relative to known systems, while the total vessel flow rate is the same as known systems as per cubic meter load. Further, an overpressure may be added to the vessel via compressed air. In accordance with other aspects, an Impact value is defined which relates nozzle flow rate, pressure, distance, etc. with moisture absorption in paperboard containers.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a schematic cross-sectional side view prior art spray water retort system;
FIG. 2 is a schematic side view of a prior art spray nozzle;
FIG. 3 is a schematic cross-sectional side view of one embodiment of a spray water retort system formed in accordance with the present invention;
FIG. 4 is a schematic side view of one embodiment of a spray nozzle formed in accordance with the present invention;
FIG. 5 is a table showing spray characteristics of wide spray nozzles relative to a straight jet nozzle;
FIG. 6 is a schematic cross-sectional side view of an alternative embodiment of a retort system formed in accordance with the present invention; and
FIG. 7 is a schematic cross-sectional side view of another embodiment of a retort system formed in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The inventors herein have determined that the impact of the water droplets from the nozzles on a container is an important parameter in causing edgewise moisture penetration. As used herein, the term “container” 48 is meant to describe a load that includes a paperboard component. The greater the droplet impact on the container, the greater the moisture penetration into the exposed paperboard edges. The droplet impact administered to a load in prior art nozzle arrangements has resulted in excessive moisture penetration into exposed paperboard edges. The present invention includes a number of features that seek to decrease the impact of the water droplets by altering the nozzle characteristics and impact pattern. These features may be used singularly or jointly depending on the characteristics of the container and depending on the pressure and temperature profiles required for the particular foodstuff.
Referring to FIGS. 3 and 4 , the present invention includes the use of a water spray nozzle with a wider spray range. Instead of using a nozzle with a spray angle of 75 degrees (as in FIG. 2 ), the present invention uses a nozzle 50 with a spray angle γ in the range of about 100 degrees to about 115 degrees. The nozzle 50 is still preferably a solid cone nozzle. As used herein with respect to the present invention, the adjective “solid cone” refers to spray volumes having two dimensional base shapes—for example, circular as well as non-circular base shapes (squares, triangles, etc.) Alternatively, air-atomizing nozzles that produce a cloud of small droplets could be used. Using a wider spray angle results in an increase in the spray width and overall spray area. In one embodiment, the distance D′ between the nozzle 50 and the container contact surface is in the range of about 70 mm to about 200 mm, with the shorter distance typically occurring at the tops of the load. See FIG. 3 particularly. In another embodiment, good results have been obtained using a minimum distance of 100 mm.
In addition, the flow capacity of the wider spray nozzles may be reduced to an amount in the range of about 5.5 liters/min to about 7 liters/min, which is approximately 40% of the prior flow capacity. Reducing the flow of the nozzles, however, can have an adverse effect on the temperature distribution. In order to assure that a good temperature distribution is maintained in the retort load, the number of nozzles has been increased so that the total flow is equivalent to the pre-existing total flow levels, as per cubic meter of load.
In FIG. 3 , the crosswise number of distribution pipes is increased from 3 to 5 top pipes, with a corresponding increase in nozzles per processing station as well. Further, distribution pipes and nozzles 50 are located on each side. FIGS. 6 and 7 show alternative embodiments with increased distribution and nozzle arrangements. It should be understood that any alternative distribution arrangement or number of nozzles which results in similar flow characteristics through the container and which provides the reduced droplet impact on the container, is to be regarded as similar to the above described solution, and, as a consequence, part of the present invention.
Reducing the flow capacity per nozzle to a level at or below approximately 5 liters/min is not generally advisable. While doing so will reduce the droplet impact on the container, it will also require the use of a large number of nozzles in order to maintain the total flow—which adds cost of the system. Furthermore, such reduced flow nozzles have typically smaller orifices that could easily clog with debris, scale particles, or other objects.
To further understand the relationship between nozzle spray angle and impact force, the inventors have used a system of numerically defining what arrangements will produce satisfactorily low levels of edge-wicking. This system uses an “Impact” value that is defined below. First, however, referring to FIG. 5 , a graphical illustration of the relationship between nozzle spray angle and a solid cone nozzle's percentage impact efficiency and its percentage total impact force is described visually.
In FIG. 5 there are two lines plotted. The lower line 60 is a plot of the percentage of the total impact that would be felt at a given distance between the nozzle and the receiving surface, according to a given spray angle, and as compared to a straight jet of water. The upper line 66 is a plot of the percentage of the droplet impact efficiency of a nozzle at the same distance, according to a given spray angle. A reduction in efficiency means the impact effect is reduced when the spray angle increases (due to flow losses occurring inside the nozzle.)
For example, a straight jet of water would produce a total impact force of X amount at a given distance of Y between the nozzle and the impact surface. A nozzle having a spray angle of 75 degrees for the same circumstances would result in an impact force at the container surface that is only 0.25% of the total impact force of the straight jet nozzle. The droplet impact efficiency for the 75 degree spray angle nozzle would be roughly 65% of the value of the droplet impact efficiency for the straight jet nozzle.
As will be appreciated from viewing FIG. 5 , widening the spray angle does not significantly lower the percentage of the total impact force that is used, but instead lowers the droplet impact efficiency of the nozzle. A lower impact efficiency means less edge-wicking will occur. By enlarging the spray angle from 75 degrees to 110 degrees, these efficiencies reduce from about 65% and 0.25% to about 38% and 0.1%, respectively, resulting in approximately 4 times less efficiency (i.e., the result of (65/38)×(0.25/0.1).
The inventors herein have used a numeric relationship between the impact on a paperboard container and the amount of edge-wicking on the containers closest to the nozzles. The Impact is defined as:
Impact=(0.0324)·(Flow)·√{square root over (pressure)}·( Imp Eff )·( Perc Tot Imp )·(Distance Factor)
where 0.0324 is a numerical adjustment factor (due to the units used), Flow is the flow rate through the nozzle in units of liter/min, pressure is the supply pressure of the nozzle in units of kg/cm 2 , Imp Eff is the impact efficiency (unitless), Perc Tot Imp is the percentage of the total theoretical impact (unitless); and Distance Factor is a unitless factor correcting for distance that is different from 30 cm (for which the data is given in FIG. 5 .)
Current experimental tests have determined that an Impact reduction of 8 or greater (versus the pre-existing value) results in acceptably low levels of edge-wicking on the containers closest to the nozzles, while maintaining a good temperature distribution in each of the load positions throughout the complete retort process. Impact reduction below 8 appears to result in too great of edge-wicking. Thus, a designer should adjust the number of nozzles, the nozzle spray angles, nozzle water pressure, flow rate, and distance, etc. between the nozzle and the container accordingly. In one embodiment, good results have been found using an Impact reduction of about 10. In absolute terms, a safe impact of 0.00012 kg/cm2 or less is preferred, though positive effects may be experienced with an impact of 0.00014 kg/cm2.
To use the retort system, at the outset, the load is placed in the vessel and the vessel doors are closed. The recirculation pump is started, and the process water is thereafter continuously re-circulated. Process water goes through the distribution tubes, out the nozzles, and onto the containers.
The processing of a particular food will follow predefined temperature, pressure, and distribution rate profiles and formulas. As stated above, heated process water or direct steam injection may be used to influence temperature within the vessel. Conventional temperature means may be provided to control spray water temperature. Optional steam spreaders may be installed within the vessel above the water level, to distribute steam over the complete shell length. Controlled direct steam injection and/or heating of the spray water results in the pre-programmed temperature profile. Steam condensates are discharged to maintain the water working level. During the sterilization phase, temperature is preferably controlled to about +/−1° F. (+/−0.5° C.).
Pressure is provided by compressed air arranged to enter the vessel at select times. This results in the process following the pre-defined pressure profile. In one embodiment, the pressure within the retort is controlled by use of one or more proportional compressed air and pressure relief valves. Pressure is preferably controlled to about +/−0.4 psi (+/−0.025 bar).
A control system orchestrates the entire process, including applying spray water, regulating internal temperature, and modulating valves for compressed air inlet and pressure relief.
While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention. For example, the process fluid is typically water, though other fluids may be considered for use as well. | A retort is described for use with paperboard containers ( 48 ) to reduce moisture absorption during processing of foodstuffs therein. The improvement includes using solid cone spray nozzles ( 50 ) with spray angles in the range of about 100 degrees to about 115 degrees. In one embodiment, the distance (D′) between the nozzles and the container is in the range of about 70 mm to about 200 mm. In another embodiment, the flow rate if each nozzle ( 50 ) is reduced relative to known systems, while the total vessel flow rate is kept the same as per cubic meter load. Further, an overpressure may be added to the vessel via compressed air. In accordance with other aspects, an Impact reduction is used which relates nozzle flow rate, pressure, distance, etc. with moisture absorption in paperboard containers. | 0 |
BACKGROUND OF THE INVENTION
The hand-held transmitters or control units and the remote receivers and servos used with them in the control of slave devices such as powered model airplanes, boats, cars and the like all utilize batteries, or battery packs, usually of the nickel-cadmium cell type. It is a characteristic of these batteries that on a momentary voltage check, without a short, preceding power drain, they exhibit a satisfactory voltage level. However, on a subsequent power drain of even short duration the voltage level may fall substantially.
The battery checking device of the present invention measures both the voltage and current, the energy level, of the battery and is thus particularly adapted for checking nickel-cadmium battery cells. The circuit is relatively simple in configuration and utilizes diodes and an SCR switching element and thus has no moving parts. No external batteries or power source for the checker is required and a means is provided for adjustably adapting the checker for various battery voltages within a predetermined range. The device is small, pocket size, and plugs directly into the battery to be checked without requiring that the battery be removed from the model.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded, perspective view of the apparatus of the present invention.
FIG. 2 is a schematic diagram of the electrical circuit of the apparatus shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring initially to FIG. 1, the apparatus includes two housing halves, the upper housing member being indicated at 10 and the lower housing member being indicated at 11. These housing members are identical but, when assembled, one is inverted with respect to the other. The housing portions are held together by screws 12, accessible from the upper face of the housing, and screws 13, accessible at the lower face of the housing.
Supported on the housing wall by means of the nut 14 is a normally open switch 15, the manually operable push-button 15a of the switch being accessible at the exterior of the housing. Vertically arranged within the housing is a circuit board 16 which supports a load resistor R 1 . The board also supports a potentiometer 17 having an adjusting screw 17a which functions to adjust the electrical resistance of the potentiometer as will be further referred to with reference to FIG. 2.
Extending from the board 16 are two light emitting diodes 18 and 19 (LED), the diodes being supported in the bosses 11a and 11b respectively in the interior of the housing. The tips of the diodes 18 and 19 are generally flush with the outer face of the housing elements 10 and 11 when assembly is completed. Additional circuit components, not visible in FIG. 1, are present in the assembly, these being more specifically referred to subsequently with reference to FIG. 2.
Extending through a grommet 26 enclosing an aperture in the base of the housing member 11 is a dual conductor cable 27 which is attached to contact pins 28, the pins being housed within a conventional molded plug 33, the cap portion 32 protecting the wire and pin connection. The plug 33 is of conventional type and is adapted to plug directly into the charging receptacle on the battery support portion of the model.
Referring to FIG. 2, when the plug 33 is inserted in the charging receptacle on the battery pack, the pins 28 are connected across the battery terminals so that a DC voltage of, for example, 4.8 volts (assuming the battery is at rated voltage) is impressed across the pins. Since switch 15 is normally open, the battery potential is not impressed across the circuit components and this functions as a safety factor preventing draining of the battery should the plug 33 be inadvertently left inserted in the charging receptacle of the battery pack for an extended time period. The manually operated switch, when closed, impresses the battery potential across the load resistor R 1 , which may be a three watt, 22 ohm resistor. The closure of the switch 15 also impresses the battery potential across a voltage divider network composed of potentiometer 17, resistance R 3 (which may have a resistance of 5.6 kilohms) and the resistor R 2 (which may have a resistance of 1 kilohm). Battery voltage is further impressed across a series connected resistor R 5 (which may have a resistance of 15 ohms), a light emitting diode (LED) 18 emitting green light when in the forward conducting state and a silicon controlled rectifier (SCR) 31. The gate 31a of the SCR is connected to the junction between resistor R 2 and R 3 .
Finally, the battery voltage, at the closure of switch 15, is impressed across a series connected first diode D 2 , resistor R 6 (which may have a resistance of 220 ohms) and a light emitting diode 19 which, when conducting in the forward mode, emits red light. A second diode D 1 is connected between the junction of the diode D 2 with the LED 19 and the junction of the LED 18 with the SCR 31. The diodes D 1 and D 2 are identical germanium diodes having the identification IN60. A table, setting out the preferred resistance values and identification of the solid state components is below:R 1 22 ohms 3 wattsR 2 1 k.R 3 5.6 k.Potentiometer 17 2 k.R 5 15 ohmsR 6 220 ohmsLED 18 FLV-365LED 19 FLV-160SCR 31 C13YD 1 IN60D 1 IN60
In operation, referring primarily to FIG. 2, with the plug 33 plugged into the battery charge receptacle (not shown) in a battery pack (assumed to have a rated output of 4.8 volts), 4.8 volts will be impressed across terminals 28. The switch 15 may then be manually closed, and held closed, preferably for approximately 5 seconds. This loads the battery by connecting load resistor R 1 across its terminals. The voltage dividing network, made up of resistors 17, R 3 and R 2 , is also connected across the battery being checked. If the battery voltage is 4.6 volts or higher, the voltage drop across R 2 is high enough to trigger SCR 31 to the on mode. It will be understood that this trigger-on voltage at the gate of SCR 31 can be adjusted by means of potentiometer 17, the preferable adjustment, for the rated 4.8 volt battery, being that which permits SCR 31 to go to the on or forwardly conducting mode when the battery voltage is 4.6 volts or above.
With SCR 31 in the on mode, the main current path to SCR 31 is through the current limiting resistor R 5 and the LED 18, a secondary current path being through current limiting resistor R 6 and diodes D 2 and D 1 . This current flow causes the voltage at the junction of D 2 and D 1 to drop to a level too low to forwardly bias the LED 19 to go to the on mode; the LED 18, in the primary current path will be forwardly biased to on and will emit green light.
After the 15 second interval during which switch 15 is held closed, the switch button is released momentarily and again pressed to close the switch. If the battery is charged or at an acceptable stored energy level, during the 15 second interval when load resistor R 1 is across the battery terminals, the battery voltage will not have dropped below the 4.6 volt trigger level. The post-interval reclosing of switch 15 thus again causes SCR 31 to go to the on mode and LED 18 will again emit green light while LED 19 remains off. However, if the battery is weak, the voltage, under the 15 second loading, will drop to less than the critical 4.6 volt triggering value. Upon the momentary closing of switch 15 SCR 31 will not be triggered to the on mode. With SCR 31 off, the voltage level at the D 2 - D 1 junction will initially approach the battery voltage level causing LED 19 to be forwardly biased to the on mode and to emit red light. With LED 19 on, the resulting voltage drop across LED 19 provides a sufficient reverse bias on diode D 1 to hold it in the off mode assuring that LED 18 cannot, simultaneously with LED 19 go to the on mode.
Checking the battery with a 15 second closure of the switch 15, then a momentary reclosure, and noting the LED condition during the reclosure, thus provides a means for checking both the voltage and current condition, the energy level, of the battery. If the checker is inadvertently left connected to the battery, as long as switch 15 is not moved to closed position, there is no battery drain. Potentiometer 17 can be factory adjusted (by means of element 17a) to permit the device to be used to check a relatively wide range of rated battery voltages.
While the invention has been disclosed and described in some detail in the drawings and foregoing description, they are to be considered as illustrative and not restrictive in character, as other modifications within the scope of the invention may readily suggest themselves to persons skilled in the art. | Disclosed is a device for checking the energy level of a battery, or battery pack, of the type used in the powering of transmitters, receivers and servos used in powered model airplanes, boats, cars, etc. The circuit connects a silicon controlled rectifier (SCR) and two light emitting diodes (LED) so that the diodes give a no, no-go indication of the battery's available output compared to a predetermined standard. Initially, in the checking procedure, the battery has power withdrawn through a load resistor prior to the final go, no-go indication. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a water recovery system and, more particularly, to an apparatus and method for transforming the water vapor present in the atmosphere into water fit for human consumption, although the invention may be utilized by industrial facilities which require water for operation.
2. Description of the Prior Art
Several types of systems are available which are capable of turning atmospheric humidity into liquid water. Such systems are commonly referred to as dehumidification systems. A common type passes air through a coil which is cooled below the dew point of the outside air. Such systems presently suffer from the disadvantage that they require large amounts of energy which make them commercially impracticable.
Such water recovery systems, if they were economically feasible, would be of great advantage in areas of the world where there is sparce rainfall, although appreciable relative humidity. For example, in a desert area adjacent to an ocean, the relative humidity may be significant during most of the year, but the amount of rainfall received would be small. The advantages of a device which is capable of transforming the relative humidity of the atmosphere into water which is both suitable for consumption by humans and commercial purposes are easily seen. Also, a system which could be adapted for individual homes and commercial establishments would be highly desirable.
Present systems such as desalinization systems suffer from the disadvantages that they require that piping be installed to carry salt water to the facility and require large amounts of energy to operate which make them economically unfeasible in many instances.
What is presently needed is a system which will overcome the disadvantages present in the prior art.
SUMMARY AND OBJECTS OF THE INVENTION
The above-mentioned problems of the prior art have been overcome by the present invention which fulfills the stated requirements. The present invention is a water recovery system using refrigeration which is capable of economically converting the water vapor present in the atmosphere into water which may be transformed to a form suitable for human consumption or commercial purposes.
A general object of the invention is to provide a commercially feasible method of extracting water vapor from the atmosphere in a relatively short period of time.
A primary object of the invention is to provide a water recovery system which is simply constructed and economical to produce.
Yet another object of the invention is to provide a water recovery system which is reliable and may be used by those with no technical background.
Still another aspect of the invention is to provide a water recovery system which may be installed and operated at a cost less than that required for comparable desalinization plants.
Other objects and advantages of the invention will appear from the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a preferred embodiment of my water recovery system;
FIG. 2 is an elevational view of a preferred embodiment of my water recovery system; and
FIG. 3 is a diagrammatic representation of my invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the present invention is susceptible to modifications and alternative constructions, an illustrative embodiment is shown in the drawings and will be described in detail hereinbelow. It should be understood, however, that it is not the intention to limit the invention to the particular form disclosed; but on the contrary, the intention is to cover all modifications, equivalences and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.
Referring initially to FIGS. 1 and 2 collectively, there is shown therein my water recovery system 10.
The water recovery system comprises an air intake housing 12 and an enclosure 14.
The air intake housing 12 has an input port 16 and an output port 18. The enclosure 14 has an input opening 30, air vent 32 and exhaust vent 34.
Located within the air intake housing 12 are air intake louvers 20, air prefilter 22 and high efficiency air filter 24. The air intake louvers 20 are located in the vicinity of the input port 16 within the air intake housing 12 and are fixed in the open position and serve to protect the interior of the air intake housing 12 and the air prefilter and high efficiency air filter 22 and 24, respectively, from damage due to rain. The air prefilter 22 is located between the input port 16 and the high efficiency air filter 24 and serves to remove large particles of contaminants such as dirt, sand, debris and the like from air which enters the input port 16. The high efficiency air filter 24 is designed to eliminate smaller particles of contaminants from the air after the air has been initially cleansed of larger contaminant particles by the air prefilter 22.
The air intake housing 12 is connected to the enclosure 14 by conventional means well known to those skilled in the art. The air intake housing is connected to the enclosure in such a manner that the output port 18 is flush with the input opening 30 and the output port covers the input opening so that during operation air will not be able to enter the input opening unless it has first entered the input port 16.
Access panels 5, 7 and 9 are provided for the enclosure 14 so that entry into the enclosure for repairs, cleaning, etc. may be easily accomplished.
The enclosure 14 comprises a precipitating chamber 36, mixing chamber 38, and elimination chamber 40.
The precipitating chamber 36 is separated from the mixing chamber 38 by a panel 42 which is continuous and has an opening 44. In the opening 44 is located coil louvers 46 which when in the closed position prevent air from flowing through the opening 44 from the precipitating chamber to the mixing chamber. Conversely, when the coil louvers 46 are in the open position air is free to flow from the precipating chamber to the mixing chamber through the opening 44.
Inside the precipitating chamber 36 is located a stainless steel drain pan 48 and water elimination coil 50. The drain pan 48 is located below the water elimination coil 50. At the bottom of the drain pan 48 is located an opening 52 to which is connected to fluid transfer means such as a pipe 54. The pipe 54 is also connected to a water collection tank 56. A transfer pump 58 is provided for transferring water from the collection tank 56 to a water storage tank 60 by means of a pipe 62, the transfer pump is activated when the level of water in the collection tank reaches a predetermined level by means of an automatic device which is well known to those having ordinary skill in the art.
Located between the water collection tank 56 and the water storage tank 60 is a chemical storage tank 64, chemical inducing pump 66 and pipe 68. The pipe 68 is connected to the pipe 62 at junction A in a conventional manner. The chemical storage tank 64 contains chemicals well known to those skilled in the art for chemically treating the water which is pumped into the water storage tank. The chemical inducing pump 66 is provided for injecting controlled amounts of water treatment chemicals into the pipe 62 at junction A as water is being pumped into the water storage tank 60. These chemicals are well known to those having ordinary skill in the art and it is not deemed necessary to describe them.
At the top of the mixing chamber 38, the air vent 32 is covered by a screen 70 which prevents large objects from entering the mixing chamber by means of the air vent. Located at the air vent 32 are outside air louvers 116. When the outside air louvers 116 are open, outside air is free to travel from the environment surrounding the enclosure into the mixing chamber 38 by means of the air vent 32. Accordingly, when the outside air louvers are in the closed position, air is prevented from entering the mixing chamber from the outside environment by means of the air vent 32.
The mixing chamber is separated from the elimination chamber 40 by means of a panel 72. The panel 72 has an opening 74 through which air may pass from the mixing chamber to the elimination chamber. Located in the elimination chamber side are a condenser coil 75, a fan motor 76 and a fan 78.
The condenser coil 75 is mounted adjacent to the opening 74 in such a manner that air traveling from the mixing chamber to the elimination chamber will come into contact with the outer surface of the condenser coil.
The fan which is operably connected to the fan motor by means of a belt 81 is operated so that air is blown out of the elimination chamber through the exhaust vent 34.
The exhaust vent 34 also is covered by a screen 80 which is attached in a conventional manner to the enclosure immediately surrounding the exhaust vent. The screen 80 prevents the high speed elimination by any projectiles which may inadvertently or accidentally be expelled by the fan 78 and also prevents objects from being dropped into the fan through the exhaust vent from the surrounding environment.
A power generating means is provided for supplying electrical power to the system. Such power generating means may be a combined conventional diesel engine-electrical generator 82. It will be understood that other electrical power sources may be used.
A muffler 83 is attached to the exhaust of the diesel engine to decrease the noise pollution of the engine.
The electrical output of the electrical generator is connected by means of a power cable 84 to an electrical panel 86 for distribution to all units which require electrical power.
Now referring to FIG. 3, there is illustrated therein an enclosure 14a, having an input port 16a, an air vent 32a and an exhaust vent 34a.
The enclosure 14a comprises an air intake channel 12a, a precipitating chamber 36a, a mixing chamber 38a and an elimination chamber 40a.
In the intake channel 32 is located an air filter 21. The purpose of the air filter 21 is to eliminate particles of contaminants from the air which may enter the enclosure through the input port 16a. The filter not only insures that particles of sand and dirt will be eliminated from the air and thus will be prevented from being present in the water produced by the system, but also insures that the air passing through the air intake channel and precipitating chamber 36a is clean, thus keeping dirt and other particles from deteriorating the system components.
Heat transfer means such as a compressor 100, condenser coil 75a, combination filter-drier 104, reservoir 106, refrigerant sight glass 108, refrigerant solenoid valve 110, expansion valve 112, water elimination coil 50a and accumulator 114 is provided for the transfer of heat from the water eliminator coil 50a to the condenser coil 75a, in a manner which is well known to those having ordinary skill in the art.
In the precipitating chamber 36a is located the water elimination coil 50a which will remove water vapor from the air during operation. The process by which the water vapor is removed from the air is discussed in detail hereinbelow. The water elimination coil 50a is designed in such a way that air will come into contact with its outer surface. The panels 25, 26, 25a and 26a are situated so that the amount of air coming into contact with the outer surface of the water elimination coil is maximized when air flows through the precipitation chamber.
Located in the precipitation chamber under the water elimination coil is a drain pan 48a for catching water which precipitates onto the water elimination coil during operation. The drain pan 48a is connected to a water collection tank 56a in such a manner that water may flow from the drain pan 48a to the collection tank 56a.
A large water storage tank 60a is provided in the preferred embodiment. When desired, water may be transferred from the water collection tank to the water storage tank 60a. Chemical treatment of the water may be performed as the water travels to the storage tank or within the storage tank.
In the preferred embodiment, a chemical treatment tank 64a is provided from which chemicals for purifying water may be added to the water obtained as water is transferred from the water collection tank to the water storage tank.
In the opening between the panels 25a and 26a are located coil louvers 46a. The coil louvers 46a are of such a construction that they may be continuously varied from a totally open position, which will not obstruct the air flow between the precipitating and mixing chamber, to a completely closed position which will prevent air from passing therethrough. As can be seen, if the coil louvers 46a are closed, no air will flow through the input port 16a.
Outside air louvers 116a are mounted in the air vent 32a. The outside air louvers 116a are of a type which may be continuously varied from a completely closed position, which will prevent the passage of air therethrough, to a totally open position whereupon the outside air louvers will present negligible opposition to the flow of air through the air vent 32a.
The condenser coil 75a is mounted in the elimination chamber in the vicinity of the opening formed by panels 25b and 26b. The condenser coil 75a is located so that the amount of air passing from the mixing chamber to the elimination chamber which comes into contact with the outside surface of the condenser coil is maximized. It should be noted that it is possible to locate the condenser coil in the mixing chamber near the opening and achieve the same results.
An exhaust fan 78a is located at the exhaust vent 34a. The fan is connected so that it will expell air from the elimination chamber through the exhaust vent.
The compressor in my system is of the standard type having a suction side input 99 and a discharge side output 101. The discharge side output 101 is connected by means of tubing conventional for heat transfer systems to the input of the condenser coil 75a. The output of the condenser coil is connected by means of tubing to the filter-drier 104 which is connected to the input side of the reservoir 106. The output of the reservoir is connected to the refrigerant sight glass 108 which is connected to the refrigerant solenoid valve 110 thence to the expansion valve 112 which is subsequently connected to the water elimination coil 50a. The output of the water elimination coil is connected to the accumulator 114 which is connected to the suction side input 99 of the compressor 100. Thus, those skilled in the art will recognize that the heat transfer system comprising the above-identified units comprises a closed series loop and the refrigerant in the system will not escape to the outside environment and simiarly those will be no transfer of outside air into the heat transfer system. The method of operation of the heat transfer system is well known to those skilled in the art and accordingly will not be described herein.
Automatic Control Units (ACU) Nos. 1 and 2, 118 and 120, respectively, are provided. The ACUs are of a type known to those skilled in the art which have a monitoring sensor (in this particular situation a pressure sensor) and are capable of operating a servo motor in a predetermined manner to accomplish a desired result. In my invention, ACU Nos. 1 and 2, 118 and 120, respectively, are operably connected to motors, 112 and 124, respectively. The motors 112 and 124 are also operably connected to the coil louvers 46a and outside air louvers 116a. Thus, when the pressure sensor preceives a given pressure, the ACU will operate the motor to adjust the louvers to attempt to maintain a predetermined pressure in the heat transfer system. Thus, as the pressure perceived by the pressure sensor varies, the louvers will be opened or closed accordingly.
There is operably connected at the suction side 99 of the compressor 100 a pressure sensor of ACU No. 1, 118, which is operably connected to the coil louvers 46a through the motor 122.
The discharge side 101 of the compressor 100 is operably connected to ACU No. 2, 120, by means of a pressure sensor in the discharge line of the compressor. ACU No. 2 is operably connected to the outside air louvers 116a through the motor 124 and is capable of moving the outside air louvres 116 to a position which is a function of the pressure perceived by the pressure sensor.
While the automatic control units such as the ones described above are well known in the art, this is the first time known to the inventor that such units have been used in the particular manner described or to perform the above-identified function.
As is known to those having ordinary skill in the art, the compressor and consequently the heat transfer system will perform at greatest efficiency when it is operated at full load conditions. Full load condition is dependent on the type and model of compressor. Therefore, the conditions at which greatest efficiency will occur cannot be stated specifically except to state that it is when the compressor is operated at full load. The automatic control units aid in maintaining full load conditions on the compressor.
ACU No. 1 is designed so that if the suction pressure increases above the full load condition, the coil louvres 46a will be closed an amount sufficient to lower the suction pressure to the desired value. Similarly, if the suction pressure decreases, the coil louvres will be opened an amount sufficient to return the discharge pressure to full load conditions. Such operation insures that the compressor will be operated at its most efficient condition and thus at its most economical condition.
ACU No. 2 has a pressure sensor located at the discharge side output 101 of the compressor and is able to control the position of the outside air louvers 116a. As the discharge pressure of the compressor increases, the outside air louvers will be opened by ACU No. 2. Similarly, if the discharge pressure of the compressor decreases, ACU No. 2 will automatically close the outside air louvres 116a to a position sufficient to return the discharge pressure to the desired level. This particular method of operation tends to keep the compressor operating at maximum efficiency.
A power source 135 is provided for supplying electrical power to the units requiring it.
Referring to the figures generally, the operation of the system will now be described. The compressor is activated in a conventional manner and the refrigerant in the heat transfer system begins to flow in the direction of the arrow 130. The temperature of the water elimination coil decreases and the temperature of the condenser coil increases.
The fan motor is also energized and the exhaust fan begins to expel air from the elimination chamber. Consequently air is drawn into the elimination chamber from the mixing chamber. Air is drawn into the mixing chamber past the coil louvers and the outside air louvers. Accordingly, air is drawn into the precipitation chamber through the air intake channel.
Outside air which enters the air intake channel 50 through the input port passes the air intake louvers, and through the air filters. After passing through the air filters, the air then comes into contact with the water elimination coil. Since the water elimination coil has been cooled to just above the freezing point of water, water will precipitate onto the water elimination coil from the passing air and fall into the drain pan.
The water which falls into the drain pan passes to the water collection tank. At desired times, the water in the water collection tank is pumped to the water storage tank. As the water is pumped into the water storage tank, chemicals from the chemical storage tank are added to it by means of the chemical inducing pump. The water in the chemical storage tank is retained there until it is desired to use it.
The air which has been sucked into the precipitating chamber through the input port travels into the mixing chamber where it is mixed with outside air which has entered through the air vent. The air in the mixing chamber is sucked into the elimination chamber where it passes the condenser coil. As the air passes the heated condenser coil, there is a transfer of heat from the condenser coil to the air. Consequently, the air cools the condenser coil and thus the air becomes heated. The air in the elimination chamber is then expelled out through the exhaust vent by means of the exhaust fan.
Since it is highly desirable to operate the compressor at maximum efficiency and thus at full load conditions, there is in the suction side input of the compressor a pressure sensor for monitoring the pressure in that portion of the heat transfer system. Should the pressure in the suction side of the compressor increase above the desired or optimum level (which would be due to an overly large amount of heat being transferred to the water elimination coil from the surrounding air), ACU No. 1 will automatically activate the motor 122 and begin to close the coil louvers, thus restricting the amount of air which will travel through the precipitating chamber and consequently decrease the amount of heat energy transferred from the air to the water elimination coil thus causing the pressure in the suction side of the compressor to decrease to the desired value.
If the pressure at the suction side input of the compressor decreases below the desired or optimum level, ACU No. 1 will automatically open the coil louvers so that the air flow in the precipitating chamber increases, causing the amount of heat transferred to the water elimination coil from the surrounding air to increase. This in turn will cause the pressure at the suction side input of the compressor to increase to the desired level.
Similarly, a pressure sensor is provided in the discharge side output of the compressor for monitoring the pressure in that portion of the heat transfer system. If the pressure on the discharge side output of the compressor begins to increase, it is monitored by the pressure sensor which is connected to ACU No. 2 which controls the position of the outside air louvers. Such a pressure increase would be due to an insufficient transfer of heat from the condenser coil to the air passing the condenser coil. Consequently, ACU No. 2 is programmed to open the outside air louvers, thus increasing the amount of outside air (which enters the air vent) which will pass the condenser coil. The pressure at the discharge side output will then decrease to the desired level. It will be noted that this is accomplished since the volume of air per unit time drawn by the exhaust fan is a constant under design static pressure.
As can be seen, if the pressure at the discharge side output of the compressor decreases, ACU No. 2 causes the outside air louvers to close, thus causing the air which passed the condenser coil to comprise a smaller proportion of outside air which entered the mixing chamber through the air vent. The pressure at the discharge side output will then increase to the desired level.
Thus, by the automatic control of the coil louvres and the outside air louvres by means of ACUs No. 1 and 2 in relation to the pressure at the suction side input and discharge side output of the compressor, respectively, it is possible to automatically and continually operate the compressor at maximum load and thus at maximum efficiency even though the relative humidity of the air may vary.
It will be seen that a different arrangement of components is possible which will produce the same result. By way of example and not by way of limitation, the condenser coil 75a may be mounted in the opening formed by the panels 25b and 26b and a fan may be mounted in the elimination chamber at the opening in the panels 25b and 26b. The fan should be positioned so as to draw air out of the mixing chamber. Thus, it will be seen that this will accomplish the result desired. It will also be seen that such an arrangement eliminates the need for an elimination chamber.
Clearly what has been shown is a device which is simply constructed and inexpensive to manufacture which is capable of transforming water vapor in the atmosphere into drinkable water at a very reasonable cost. | An apparatus for transforming the water vapor in the atmosphere into liquid water comprising a precipitating chamber, a mixing chamber, heat transfer system, and means for moving atmospheric air through the system.
A method of producing liquid water from the atmosphere comprising the steps of passing a first stream of air past a heat absorbing element of a heat transfer system to cause water to precipitate onto the heat absorbing element; mixing the first air stream with a second air stream; passing the mixed air streams past the heat dissipating element of the heat transfer system; varying the proportion of amount of air from the first and second air streams to a predetermined ratio which is a function of the atmospheric conditions. | 4 |
BACKGROUND OF THE INVENTION
This invention has to do with saw blades. More particularly, the invention is concerned with an improvement in saw blades comprising a variation progressively in the rake angle of the teeth from negative to positive to enable faster initiation of the stroke on the one hand, and greater cutting albeit with greater resistence at the terminal end of a stroke whereby cutting effort is maintained relatively constant over a saw stroke.
In general, the invention pertains to blades employable in hand saws which are operated in a reciprocating manner. The blades for such saws are generally made with a negative rake, that is, the cutting surface of the tooth is slanted back for smooth cutting. A positive rake, one in which the cutting surface of the tooth is slanted forward is best adapted for rapid cutting. In general, the negative rake angle of a tooth is used for workpiece cutting cross-cut saws, the positive rake is used for rip-sawing wood or cutting very homogeneous materials. A positive rake is also advantageous in saws used for pruning, tree trimming and the sawing of wet wood.
Having a negative rake angle on the tooth enables a cross-cut saw to start easily and cut smoothly, but cutting efficiency is relatively poor. On the other hand, a positive rake angle tooth such as is provided in a rip-saw cuts very efficiently, but it is difficult to start a stroke and the teeth tend to stick in the kerf since the teeth tend to dig in to the workpiece at the initiation of the stroke. Such sticking causes buckling of the blades particularly in thin, push saws like keyhole saws, and in some instances tends to snap the blades in tension, on small pull saws like coping saws and jeweler's saws.
In presently known pruning saws of the pull type snagging of teeth is reduced by curving the blade so that the initial part of the stroke has reduced engagement force, nonetheless snagging is still present to a degree, and caused by the self-engagement tendency of the positive rake angle teeth of the saw.
SUMMARY OF THE INVENTION
It is a major objective of the present invention to provide a novel saw blade. It is a further object of the invention to provide a novel saw blade having a progressive change in rake angle of teeth from leading to trailing end. It is a further object of the invention to provide a saw which starts a cut more easily, cuts efficiently and ameliorates problems inherent in all types of saws by providing the optimum performance at any given position along the saw blade. It is a highly particular object of the invention to provide a saw blade for a reciprocating saw in which cutting effort is relatively constant over the length of the blade and the teeth are configured in such a manner as to cut easily for initiation, but to cut less easily at the end of the stroke when blade speed is highest whereby cutting efficiency and cutting ease are maximized over a given stroke.
In particular, the invention provides in a blade for a reciprocating saw having a cutting edge comprising a plurality of longitudinally aligned teeth, the improvement comprising the blade teeth having a negative rake angle near the leading end of the blade for reducing needed force for cutting at the beginning of a stroke, and a positive rake angle near the trailing end of the blade for increasing the force necessary for cutting to decelerate the saw during or at the end of the stroke, whereby cutting actions are related to expected blade speed at any given point on the saw and a relatively constant muscular effort is required over the length of a stoke. The rake angle of the first leading end tooth typically is not more than -3 degrees, and the rake angle of successive teeth changes progressively to not less than +5 degrees within the first half of the blade length. Thus in a preferred embodiment, the negative rake angle of the leading end tooth is not more than -3 degrees, the positive rake angle of the teeth on the trailing half of the blade is not less than +5 degrees, and the tooth-to-tooth progression in the positive rake direction is not greater than one degree. Additionally, the positive rake angle at the trailing end of the blade typically is greater than the positive rake angle at the midpoint of the blade.
In one embodiment of the invention each tooth has two points, the points being spaced by a notch; the blade preferably being generally symmetrical about its longitudinal midpoint, whereby the leading edges of the end teeth have a negative rake angle, for reduced effort stroking in either direction. In such embodiments the two pointed teeth may be separated by one or more single point teeth along the linear extent of the blade.
In a highly preferred embodiment of the invention, there is provided a blade for a reciprocating saw, the blade having a cutting edge comprising a plurality of longitudinally aligned teeth, the blade having first, second and third cutting zones; the first zone comprising 25% of the blade length, the second zone comprising the next 50% of the blade length, and the third zone comprising the remaining 25% of the blade length; the teeth in the first cutting zone having a negative rake angle, the teeth in the second cutting zone having a positive rake angle not less than 0 degrees and not greater than 10 degrees, and the teeth in the third cutting zone having a positive rake angle of more than 10 degrees, e.g. up to about 15 degrees. In another embodiment of the invention there is provided in a reciprocating saw blade having a cutting edge comprising a linear series of teeth, the improvement comprising the teeth having different rake angles varying from negative to positive with increasing blade speed in cutting at the tooth, whereby cutting effort progresses from easier to harder from leading blade portion to trailing blade portion on a cutting stroke.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be fully described as to an illustrative embodiment thereof in conjunction with the attached drawings in which:
FIG. 1 is a perspective view of a bow saw employing a blade according to the invention;
FIG. 2 is an enlarged fragmentary view of one form of saw blade according to the invention;
FIG. 3 is an enlarged fragmentary view of a further embodiment of the present invention;
FIG. 4 is a graphical depiction of cutting velocity versus rake angle progression over the saw blade according to the invention;
FIG. 5 is a perspective view of a hacksaw provided with a blade according to the invention;
FIG. 6 is a view like FIG. 5, and of a carpenter's saw provided with a blade according to the invention; and
FIG. 7 is a view like FIG. 5, and of an additional bow saw provided with a blade according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As will be evident from the foregoing, the present invention provides a hand saw blade in which the initial teeth at the leading end of the blade have a substantial negative rake, and the rake angle is gradually changed toward a positive rake angle within the first half of the blade, the remainder of the blade continuing with positive rake angle teeth. The length of the negative rake angle tooth portion of the blade depends on the overall blade length.
It has been determined that the greatest amount of sawing force is applied at the beginning of a saw stroke. This is due in part to the requirement that the mass of the saw itself be accelerated and in part to the necessity to overcome the "stiction" of the points of the teeth resting on the surfaces of the softer material being cut and embedding or self-engaging themselves in that material.
Once the saw begins to move and pick up velocity, both of the resistive forces of inertia and stiction are greatly diminished. The force peak at the beginning of the stroke is all the more fatiguing because applied muscle force encounters the static and the slow moving resistance of the saw. Therefore, a blade design which minimizes the cutting force at the beginning of the stroke, until blade velocity is achieved, results in a greatly reduced physical effort to produce efficient sawing.
The present invention achieves a nearly constant muscular effort by providing the leading end teeth with approximately a -5 degree rake angle, this rake angle gradually changing to a +10 degree rake within the first half of the blade length. A further embodiment of the invention provides an increased positive rake angle of up to 15 degrees in the trailing few inches of the blade, to transfer the deceleration energy of the saw into cutting action. The described configuration is achievable in a variety of saw blades each of which when assembled with a handle arrangement provides a saw with unusually smooth starting and fast cutting action, and all with minimal muscular effort and fatigue.
With reference now to the drawings in detail, in FIG. 1 there is shown sawing a workpiece log L a bow saw B comprised of a saw blade 10 according to the invention, supported in tensioned relation by terminals 12, 14 of the bow 16. Saw blades 20 and 30 shown in FIGS. 2 and 3, respectively, and to be more particularly described hereinafter, illustrate one form of blade mounting structure in the form of holes 18 adapted to receive fasteners which are themselves not shown. In this manner the blades 10, 20, or 30 can be mounted in a bow such as the bow 16. It is further to be noted here that the bow 16 is but one form of handle defining blade support, with the blades of the invention being capable of mounting permanently or removably in a wide variety of saw types, the general type being generically known as a reciprocating saw of FIGS. 5, 6 and 7.
With reference now to FIG. 3 in particular, the saw blade 30 has a cutting edge 32 comprising a plurality of longitudinally aligned teeth 34. The blade 30 is typically comprised of three sections, a first leading section denominated 1 in the drawing constitutes about 25% of the overall length of the blade. Section 1 appears at the bottom of FIG. 3 and it will be observed has teeth 341 which are sloped rearwardly or have a negative rake with reference to the blade 30. These teeth are raked at about a -3 degrees at the first or end tooth 341a and are raked less as the tooth progression moves toward the center of the blade 30. The teeth 341 in blade section 1 are particularly adapted to easy startup of a blade stroke, although they are not as aggressive in cutting for a given amount of muscle effort.
The blade 30 has a middle, second section 2, generally constituting about 50% of the overall blade length. Blade section 2 has teeth 342 which have a positive rake angle, that is a rake angle not less than 0, and generally not more than 10 degrees.
The blade 30 has a third trailing section 3, generally constituting about 25% of the overall blade length. Blade section 3 has teeth 343 which have a positive rake angle, up to about 15 degrees being preferred. The positive rake angle teeth 342, 343 are more efficient in cutting owing to their inherent tendency to dig into the workpiece, but they are hard starting for the same reason. The present saw blade utilizes the inherent strengths of both negative and positive rake angle teeth, while avoiding substantially the problems of either. The key to this result is the progressive change in rake angle from leading to trailing ends of the blade considered from the standpoint of the saw user. Thus the difficulty in startup is related to the absence of appreciable speed, and the energy expended in realizing speed of blade movement is necessarily counteracted by further energy expenditure in slowing the saw down at the end of a stroke, whereby all energy input is not consumed in overcoming friction. The present saw blade provides in its first (leading) section 1 negatively rake angled teeth 341 so it it is easy starting, and in its second and third sections 2, 3 (trailing) positive rake angle teeth which move easily with high cutting efficiency once started, and finally progressing to a final positive rake level at which blade speed is effectively translated into cutting energy, simultaneously reducing saw speed with relatively little muscle energy involved, and increasing rapidly the depth of the kerf.
In general, the desired result is realized where the rake angle of the first leading end tooth 341 is not more than -3 degrees in rake angle, and in which the rake angle of successive teeth 342, 343 changes progressively to not less than +5 degrees, the preferred rate of change in the positive rake direction (section 1 to section 3) being not greater than 1 degree. Additionally the positive rake angle at the trailing end of the blade (section 3) is preferably greater than the positive rake angle at the midpoint of the blade (section 2).
In FIG. 4 the net effect of tooth rake angle on the velocity of a reciprocating saw blade is clearly illustrated. When the sawing force applied is generally constant, which is the case with the limited strength and energy applied to the operation of a hand saw, the factor controlling cutting velocity is the individual tooth rake angle. In FIG. 4 Section 1 represents the leading end of the saw blade according to the invention, where the tooth rake angle is negative. The saw starts easily and with a continuing constant applied force achieves a maximum velocity in approximately the first 25% of the blade length. In the Section 2 shown the acceleration has ceased, and the continuing applied force acts on teeth that are near 0 rake in the central 50% of the blade length, which produces nearly constant velocity for a constant force. In Section 3 shown the individual tooth rake angle changes to a maximum positive rake, with each successive tooth taking a more aggressive cut, thereby decelerating the blade in the trailing 25% of its length. In normal manual cutting the applied force diminishes near the end of stroke, and the kinetic energy carries the stroke to its conclusion. According to the invention, more of the energy is converted to cutting work which decelerates the blade near the end of stroke. This not only improves the working efficiency, but also allows the application of normal cutting force for a longer portion of the stroke, producing more cutting action per saw stroke. Tests conducted by the inventor have shown that the tooth rake angle distribution shown in FIG. 3 operates generally as illustrated in FIG. 4 to produce increased cutting efficiencies of as much as 50% as compared to prior art saws.
Turning now to FIG. 2, there is shown a special form of blade according to the invention. More particularly, the blade 20 has a longitudinal series of teeth 36, each of which is configured to have two points, i.e., be bicuspid, with a valley shaped notch 38 therebetween. Each of the adjacent teeth 36 are separated by a smaller single point tooth 40. The tooth pattern of the FIG. 2 blade provides a negative rake on edge 360 of the first tooth 361 at the leading end of the blade when starting the stroke in Section 1, and a negative rake on edge 362 of the first tooth 363 at the leading end of the blade when starting the stroke in Section 3. A positive rake angle is simultaneously provided on these same teeth 361, 363, at edges 364, 366. In this embodiment, when the stroke direction is through Sections 1, 2 and 3 successively, the leading edge rake angle on each tooth is essentially the same as shown in the saw blade of FIG. 3. Also when the stroke direction is reversed for the same blade of FIG. 2, when the stroke direction is through Sections 3, 2, and 1 successively, the leading edge rake angle on each tooth is again the same. The blade operates then with a reciprocating stroke which cuts identically in both directions of stroke, wherein the leading 25% of the blade has negative rake on the leading tooth edges, the central 50% of the blade has approximately 0 rake angle on the leading tooth edges, and the trailing 25% of the blade has positive rake angle on the leading tooth edges. Since the principal cutting teeth are bicuspid, the leading edges of the teeth are also those towards the direction of motion.
In FIGS. 5, 6 and 7, other saw structures i.e. a hacksaw H, a carpenter's saw C and a bow saw S respectively are depicted, the former two with blade teeth like those shown in FIG. 3, and the third with blade teeth like those shown in FIG. 2.
There is thus provided an improved form of saw blade for a reciprocal saw. | A blade for a reciprocating saw having a cutting edge comprising a plurality of longitudinally aligned teeth, the improvement comprising the teeth having a negative rake angle near the leading end of the blade for reducing needed force for cutting at the beginning of a stroke, and a positive rake angle near the trailing end of the blade for increasing the force necessary for cutting to decelerate the saw during or at the of the stroke, whereby cutting actions are related to expected blade speed at any given point on the saw and relatively constant muscular effort is required over the length of a stroke. | 8 |
FIELD OF THE INVENTION
This invention relates to internal combustion engine diagnostics and, more particularly, to diagnosing fault conditions in an internal combustion engine air/fuel ratio control system.
BACKGROUND OF THE INVENTION
It is well-established in automotive internal combustion engine controls that conventional engine exhaust gas catalytic treatment devices operate at high efficiency when the engine air/fuel ratio is controlled substantially at the stoichiometric ratio, as illustrated by the curves 100, 102, and 104 of FIG. 1, representing the efficiency in treating the exhaust gas constituent elements of hydrocarbons HC, carbon monoxide CO and oxides of nitrogen NOx, respectively, as a function of engine air/fuel ratio. Feedback signals indicating air/fuel ratio control performance are provided by engine exhaust gas oxygen sensors which have a characteristic output "S" voltage curve, such as curve 110 of FIG. 2. Actual engine air/fuel ratio information may be provided by monitoring the output signal of an oxygen sensor positioned in the engine exhaust gas path upstream, according to the normal direction of exhaust gas flow, from the catalytic treatment device. The performance of the overall engine emissions control system including that of the air/fuel ratio control system and the exhaust gas treatment system may be determined by monitoring the output of an oxygen sensor positioned in the exhaust gas path downstream, according to the normal direction of exhaust gas flow, from the catalytic treatment device.
When the downstream oxygen sensor output signal is within a predetermined voltage range defined by lower voltage Vl and upper voltage Vr, which may be approximately 200 and 600 millivolts, respectively, for a typical zirconium oxide sensor as illustrated by curve 110 of FIG. 2, a healthy catalytic treatment device should operate efficiently. Any signal deviation outside the predetermined voltage range should be rapidly driven back into the range through the activity of the closed-loop engine air/fuel ratio controller, and through the oxygen storage and release activity of the conventional catalytic treatment device. Signal 120 of FIG. 3 illustrates a typical output signal pattern for a downstream oxygen sensor in a properly operating engine and emissions control system with a high catalytic treatment efficiency, indicated by only temporary excursions of the downstream sensor signal VO2 into saturation, indicated by a signal VO2 being below Vl or above Vr.
Downstream oxygen sensor voltage signal deviations outside the predetermined voltage range that persist for a significant amount of time indicate a system performance problem that may likely lead to a significant reduction in exhaust gas aftertreatment efficiency which, if left unremedied, may lead to substantial increase in vehicle emissions. Signal 122 of FIG. 4 illustrates a typical downstream oxygen sensor signal with a rich bias which may indicate an engine or emissions control system fault condition, such as may be caused by a heavily loaded evaporative canister, indicated by too significant an amount of time above the threshold signal voltage Vr, and signal 124 of FIG. 5 illustrates a potential fault condition corresponding to a lean bias of the downstream sensor, such as may be caused by a system air leak, indicated by too significant an amount of time below the threshold signal voltage Vl.
Proposed diagnostics to detect performance deterioration in specific engine and exhaust system components are typically complex, throughput intensive, and expensive to incorporate, making them poorly suited to applications requiring system level diagnostics with even reasonable controller throughput and cost constraints, and making them difficult to install, calibrate and maintain.
It would therefore be desirable to develop a simple, inexpensive, yet reliable engine control system diagnostic, especially to diagnose whether the engine air/fuel ratio controller is operating in a manner supporting efficient operation of the catalytic treatment device.
SUMMARY OF THE INVENTION
The present invention is directed to a desirable engine control system diagnostic for determining and indicating conditions that reduce the efficiency of operation of a catalytic treatment device through a simple, unintrusive procedure which adds little additional controller throughput burden and which is relatively easy to install, calibrate and maintain.
More specifically, the present diagnostic diagnoses deviation in exhaust gas treatment performance by monitoring the condition of the post-converter oxygen sensor, located in a position in the engine exhaust gas path downstream, according to the direction of exhaust gas flow, from the catalytic treatment device. The output signal of the sensor is monitored for deviations into saturation regions defined by predetermined voltage threshold values. Sustained operation in a saturation region indicates a potential engine control or emissions control system problem, such as a poorly responding engine air/fuel ratio control, a deterioration in the oxygen storage and release capacity of the catalytic converter, an air leak in the system, or a heavily loaded evaporative system canister. The time of operation in a saturation region is determined through a post-converter oxygen sensor sampling process while closed-loop air/fuel ratio control is active, and while operating conditions are present in which engine exhaust gas volume is relatively high, such as during engine acceleration and high speed cruising. Several samples of the post-converter exhaust gas oxygen concentration are taken during the sampling process. The relationship of the samples to a predetermined threshold value representing the threshold into the closest saturation region then indicates the performance of the system in supporting efficient engine emissions reduction. If the relationship indicates unacceptably low efficiency, a fault condition may be indicated such as by storing information in non-volatile memory device indicating the condition, and by notifying the vehicle operator so that appropriate action may be taken to identify the source of the condition and to make appropriate correction.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be best understood by reference to the preferred embodiment and to the drawings in which:
FIG. 1 is a graphical illustration of the typical effect of engine air/fuel ratio on catalyst efficiency in a conventional catalytic treatment means;
FIG. 2 is a graphical illustration of a typical exhaust gas oxygen sensor "S" curve;
FIGS. 3-5 graphically illustrate the post-converter exhaust gas oxygen sensor output signal characteristic for varying performance levels of the engine and exhaust gas treatment systems;
FIG. 6 is a general schematic drawing of the engine control and diagnostic hardware of the preferred embodiment; and
FIGS. 7-10 are computer flow diagrams illustrating a series of controller operations for carrying out the diagnostic of this invention in accord with the preferred embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 6, intake air received in internal combustion engine 10 past intake air or throttle valve 14 is combined with an injected fuel quantity for combustion in any of a plurality of engine cylinders (not shown), producing exhaust gasses which are guided out of the engine via exhaust gas conduit 26 to a catalytic treatment device 28, which may be a conventional three-way catalytic converter. The treated exhaust gas passes out of the device 28 through exhaust pipe 30 for release to the atmosphere.
Conventional oxygen concentration sensors 32 and 34, which may be conventional zirconium oxide sensors, are positioned in the conduit 26 and tailpipe 30, respectively, on either side of the converter 28. Upstream sensor 32 is positioned upstream of the converter 28 along the normal direction of flow of engine exhaust gas, and downstream sensor 34 in tailpipe 30 is positioned downstream of the converter 28 along the normal direction of flow of engine exhaust gas. Upstream sensor 32 transduces the concentration of oxygen passing through the conduit 26 by the sensor 32 prior to catalytic treatment thereof by catalytic treatment device 28, and outputs signal Vafr indicative thereof, for example for use as a measure of actual engine air/fuel ratio in a conventional closed-loop air/fuel ratio control process. Downstream sensor 34 transduces the concentration of oxygen passing through the pipe 30 after treatment thereof by the catalytic treatment device 28, and outputs signal VO2 indicative thereof, for example for use in the diagnostic process of this embodiment, to be described.
Engine intake mass airflow rate is sensed through conventional mass airflow sensor 16, such as a hot wire device or other generally available airflow sensor which outputs signal MAF indicating the mass of intake air passing thereby. Engine coolant temperature sensor 20, such as a conventional thermocouple or thermistor placed in or in proximity to a path of circulation of engine coolant (not shown) transduces engine coolant temperature into output voltage signal TEMP.
Conventional engine controller 36, such as a single-chip microcontroller including such generally-known elements as a central processing unit CPU 38, random access memory device RAM 40, read only memory device ROM 42, and non-volatile memory device NVRAM 44. The CPU further includes a conventional arithmetic logic circuit (not shown) for carrying out such operations as sampling input signals, such as signal VO2, and carrying out mathematical operations, such as manipulating input signal samples through predetermined formulae, such as formulae representing lag filter processes stored in controller read only memory 42, comparing samples to thresholds, etc. as is generally understood in the art. More generally, the elements of the controller 36 operate to provide for sampling of input signals, such as including the described signals, MAF, TEMP, Vafr, and VO2 and, through execution of a series of controller operations stored in the form of controller instructions in ROM 42, processes the input signals and generates a series of output control and diagnostic output signals for application to common engine control actuators and engine diagnostic indicators.
Included in the controller instructions are the operations illustrated in FIGS. 7-10 for carrying out engine and emission control system diagnostics. Generally, such operations provide for detection of appropriate test conditions and, when such conditions are present, samples, filters, and analyzes the signal VO2 to determine whether the downstream oxygen sensor is persisting in a saturation condition indicating an improperly responding air/fuel ratio control and a resulting low efficiency emission treatment system. The operations of FIG. 7 are initiated upon power-up of the controller 36 of FIG. 1, such as when ignition power is manually applied to the controller 36 by the vehicle operator. The controller is configured to automatically initiate the operations of FIG. 7 when ignition power is applied to the controller, beginning at an initial step 200 and proceeding to a next step 202 at which standard initialization operations are provided, including setting pointers, flags, and counters to predetermined initial values and by clearing memory locations for use in controller operations. A diagnostic startup flag is next set at a step 204 for use in the routine of FIG. 8. Interrupts, including standard timer and event-based interrupts are enabled to occur following time intervals or following control events at a next step 206, including a timer interrupt setup to occur at least every fifty milliseconds while the controller 36 is operating. The interrupt of at least fifty milliseconds is enabled and is pre-configured to direct controller operations to the routine of FIG. 8, to be described. After enabling the interrupts, background operations are carried out at a next step 208. Such operations may include any low priority operations required to be executed repeatedly while the controller is operating, including conventional system diagnostic and maintenance operations generally known in the art, which may be temporarily suspended upon the occurrence of the enabled timer and event-based interrupts.
For example, upon occurrence of the timer interrupt of at least fifty milliseconds that was enabled at the step 206, any current operations, such as the background operations of the step 208, are temporarily suspended to allow for servicing of the interrupt, which servicing includes execution of the operations of the routine of FIG. 8, beginning at a first step 220 and proceeding to a step 222 to determine the status of the startup flag. If the startup flag is set, indicating that the current iteration of the routine of FIG. 8 is the first since the power-up of the controller, a next step 224 is executed to set diagnostic values to initial values, such as by clearing random access memory locations having the labels of FO2, RICHSUM, LEANSUM, RICHCNT, LEANCNT, RNUMAVG, LNUMAVG and TESTCNT. Additionally, the memory location having label DNCNT is set to an initial value of eighty, LEANAVG is set to 200, RICHAVG is set to 600, and the startup flag is cleared.
After initializing the values at the step 224, or if no initialization was determined to be required at the step 222, the input signal TEMP indicating engine coolant temperature is sampled at a next step 226. If TEMP exceeds sixty degrees Celsius at a next step 228, a first test condition requiring the engine to be sufficiently warmed up that it may be assumed that the oxygen sensors 32 and 34 of FIG. 1 are active, is met, and the signal MAF indicating engine intake airflow rate is next sampled at a step 232. A further test condition is analyzed at a next step 234 in which MAF is compared to a MAF range defined by a low MAF value MAFLO, of about ten grams per second, and a high MAF value MAFHI of about thirty grams per second. IF MAF is within the range, then a representative measure of the function of the air/fuel ratio control system may be made as is generally understood in the art, and the current diagnostic continues by proceeding to sample signal VO2 at a next step 236. The VO2 sample is next filtered in accord with a conventional lag filter process at a step 238 to form filtered value FO2, as follows
FO2=FO2+K(VO2-FO2)
in which K is a predetermined filter coefficient of about 0.1 in this embodiment. After filtering VO2, the count value DNCNT, used to monitor the number of VO2 samples used to form value FO2 is decremented at a next step 240. If DNCNT is determined to have been decremented to zero at a next step 242, then a sufficient number of samples have been incorporated into the formation of FO2 to assure a reasonable representation of the exhaust gas oxygen content downstream of the catalytic treatment device 28 of FIG. 1, and DNCNT is reset to eighty and a test counter TESTCNT is incremented at a next step 244 as a count of the number of valid FO2 values that have been generated. The FO2 value is next analyzed at steps 246 and 248, to determine whether it indicates the downstream oxygen sensor is operating in saturation, indicating a potential system failure. More specifically, if FO2 is less than a calibrated minimum oxygen sensor signal LEANMIN, which is set to 100 millivolts in this embodiment indicate the threshold voltage below which the sensor signal VO2 indicates the sensor is within the saturation region. If FO2 is less than LEANMIN, then a lean signal data analysis routine is executed at a next step 258 to analyze the lean sensor output signal information, through the operations of the routine of FIG. 9, to be described. After executing the operations of the routine of FIG. 9, the routine of FIG. 8 resumes by proceeding to a next step 230, at which the routine of FIG. 8 returns controller operations to any prior operations that were suspended upon occurrence of the interrupt that invoked the operations of FIG. 8.
Returning to step 246, if FO2 is not less than LEANMIN, then FO2 is next compared to a calibrated threshold voltage RICHMAX defining the voltage threshold above which the sensor signal VO2 indicates the sensor is operating within an upper saturation region. RICHMAX is set to about 800 millivolts in this embodiment. If FO2 exceeds RICHMAX at the step 248, a rich data analysis routine is next executed at a step 260, by executing the operations of the routine of FIG. 10 to analyze FO2 and any prior FO2 values to determine if the system has been operating in rich saturation for an extended period of time indicating a potential system fault condition under which the catalytic treatment device 28 of FIG. 1 may not be operating at a high level of catalytic treatment efficiency.
Upon completing execution of the operations of FIG. 10, the routine of FIG. 8 continues from the described step 260 to the described step 230 to return to any prior controller operations. Returning to the step 248, if FO2 was determined to not be greater than the threshold voltage RICHMAX, then the current filtered oxygen sensor signal indicates operation outside of saturation, such that exhaust gas conversion efficiency may be assumed to be at an acceptable level, and the routine moves to a next step 250, to compare TESTCNT to a calibrated value, such as about 3000 in this embodiment. If TESTCNT exceeds the calibrated value, then a sufficient amount of time outside saturation has occurred prior to any diagnosis of a fault condition though the operations of the routines of FIGS. 9 and 10 that the system may be diagnosed as "healthy" which corresponds to a sufficient amount of system operation outside of saturation to support efficient catalytic treatment of engine exhaust gas. For example, if, prior to 3000 samples being determined to be outside of saturation at the step 250, either the lean data analysis routine of FIG. 9 or the rich data analysis routine of FIG. 10 were to diagnose a fault condition, the fault would be stored and/or indicated, and the diagnostic operations would cease until the next controller power-up operation, such that the step 252 would not be executed. Accordingly, if the step 252 is executed, there has been no fault detected over a significant amount of analysis to indicate that the system is operating in a manner supporting efficient catalytic treatment of the engine exhaust gas and, to indicate such condition, the routine moves to a next step 252 to indicate that no fault condition has been detected, such as by storing a code in controller non-volatile memory. The interrupt used to initiate the routine of FIG. 8 is next disabled at a step 254 to prevent further air/fuel ratio control system diagnostics until the next engine startup. Alternatively, rather than disabling an interrupt, a flag may be set in controller memory indicating the current diagnostic is complete. Such a flag would then be checked upon each occurrence of the interrupt and, if set, the operations of the routine of FIG. 8 would not be executed following the interrupt. Such an alternative allows for continued use of the interrupt for other purposes, such as for carrying out other system control or diagnostic operations, for example that may be required periodically while the controller 36 is operating. After disabling the interrupt or, in the alternative embodiment, setting the described flag, the described step 230 is executed to return to any operations that were ongoing at the time of the interrupt. However, if TESTCNT does not exceed the calibrated value at the step 250, further information is required to complete the diagnostic of this embodiment, and the routine moves directly to the described step 230 without disabling the interrupt or setting the flag. Returning to the steps 228 and 234, if either test condition is not met, such as the TEMP signal being less than sixty degrees Celsius at the step 228 or the signal MAF being outside the predetermined range at the step 234, the diagnostic is not continued, as test conditions do not support accurate diagnostic analysis, by proceeding to the described step 230. Further, if DNCNT is not equal to zero at the step 242, more samples are required in the generation of an informational FO2 value, and the routine is exited via the step 230 to wait for the next interrupt to gather yet another VO2 sample.
The lean data analysis operations of FIG. 9 are executed when initiated at the described step 258 of FIG. 8 to analyze the filtered oxygen sensor samples found to be in the lower saturation region, to determine if the time in saturation indicates air/fuel ratio control performance not supporting highly efficient catalytic treatment of the engine exhaust gas. The routine begins at a step 300 and proceeds to a next step 302 at which LEANSUM, which is a sum of all FO2 values for the current diagnostic test that were determined to be less than the lower threshold LEANMIN, is updated by adding to it the current FO2 value. A count LEANCNT of all FO2 values used to form LEANSUM is next incremented at a step 304. If LEANCNT is equal to a calibrated threshold, set to twenty in this embodiment, at a next step 306, then enough FO2 values have been processed and incorporated into LEANSUM to yield a measure of the amount of deviation in sensed oxygen by downstream sensor 34 of FIG. 1 below the threshold LEANMIN to determine whether the deviation is a mere transient deviation or whether a significant deviation below LEANMIN is persisting, indicating a performance problem.
Accordingly, if LEANCNT is equal to twenty at the step 306, the sum of lean deviations is processed by first preserving a current lean signal average value LEANAVG as OLDLEANAVG at a step 308, and next by generating an average of the twenty FO2 values that was used to form LEANSUM at a next step 310 through a simple averaging process, for example by storing the quotient of LEANSUM divided by LEANCNT as LEANAVG. LEANSUM and LEANCNT are next cleared at a step 312 to allow for a next test iteration, and the two most recent average values are filtered through a conventional filtering process at a next step 314. The filtering process may be a conventional infinite impulse response filter taking the form of a common lag filter having a calibratable filter coefficient, set to about 0.3 in this embodiment. For example, the filter process may be as follows
FAVG=OLDLEANAVG+C(LEANAVG-OLDLEANAVG)
in which FAVG is the filter output and C is the filter coefficient. After filtering the average values, a count of the number of average values incorporated into the filtered average is maintained by incrementing a stored count value LNUMAVG at a next step 315. The filtered averages are next compared to a predetermined lean threshold value LEANTHR defining the largest filtered average value that indicates operation within the lean (lower voltage) saturation region. LEANTHR is set to about 150 millivolts in this embodiment to indicate a threshold into a lean saturation range. Any filtered average value less in magnitude than the threshold LEANTHR indicates a sustained presence in saturation that will likely drive the catalytic treatment device 28 of FIG. 1 into a low efficiency operating range, as described. Accordingly, if the filtered average is less than LEANTHR at the step 316, and at least two averages were used in the formation of the filtered average value as determined by comparing LNUMAVG to two at a next step 318, then a lean fault condition is indicated at a next step 320, such as by storing a fault code in controller memory, by illuminating an indicator on a vehicle instrument panel (not shown), by energizing an aural alert means, such as a chime or tone, or by providing any means of indicating or storing a failure of the air/fuel ratio control system that may lead to reduced catalytic treatment efficiency, to support conventional repair or replacement activities. After indicating the failure or fault condition, the interrupt that invoked operation of the routine of FIG. 8, and thus of FIG. 9, is disabled at a step 322 so the diagnostic of FIG. 8 is not executed until the next time the controller 36 is turned on, such as following a vehicle startup operation. The manner of disabling the interrupt may be that described for the step 254 of FIG. 8. A step 324 is next executed to return to the operations following the step 258 of FIG. 8.
Returning to the step 318, if the number of averages used to form the filtered average value as indicated by LNUMAVG is less than two, further analysis is required to accurately diagnose the air/fuel ratio control system and the described step 324 is executed. Likewise, if LEANCNT was not yet incremented to twenty as determined at the step 306 or if the filtered averages were determined to not be less than LEANTHR at the step 316, the described step 324 is executed to return to the operations of FIG. 8.
The rich data analysis operations of FIG. 10 are executed when initiated at the described step 260 of FIG. 8, beginning at a first step 350 and proceeding to a next step 352 at which RICHSUM, which is a sum of all FO2 values for the current diagnostic test that were greater than the upper threshold RICHMAX, is updated by adding to it the current FO2 value. A count RICHCNT of all FO2 values used to form RICESUM is next incremented at a step 354. If RICHCNT is equal to a calibrated threshold, set to twenty in this embodiment, at a next step 356, then enough FO2 values have been processed and incorporated into RICHSUM to yield a measure of the amount of deviation in sensed oxygen by downstream sensor 34 of FIG. 1 above the threshold RICKMAX to determine whether the deviation is a mere transient deviation or whether a significant deviation above RICHMAX is persisting, indicating a performance problem.
Accordingly, if RICHCNT is equal to twenty at the step 356, the sum of rich deviations is processed by first preserving a current rich signal average value RICHAVG as OLDRICHAVG at a step 358, and next by generating an average of the twenty FO2 values that were used to form RICHSUM at a next step 360 through a simple averaging process, for example by storing the quotient of RICKSUM divided by RICHCNT as RICHAVG. RICHSUM and RICHCNT are next cleared at a step 362 to allow for a next test iteration, and the two most recent average values are filtered through a conventional filtering process at a next step 364. The filtering process may be a conventional infinite impulse response filter taking the form of a common lag filter having a calibratable filter coefficient, set to about 0.3 in this embodiment. For example, the filter process may be as follows
FAVG=OLDRICHAVG+C(RICHAVG-OLDRICHAVG)
in which FAVG is the filter output and C is the filter coefficient. After filtering the average values, a count of the number of average values incorporated into the filtered average is maintained by incrementing a stored count value RNUMAVG at a next step 365. The filtered averages are next compared to a predetermined rich threshold value RICHTHR defining the largest filtered average value that indicates operation within the rich (upper voltage) saturation region. RICHTHR is set to about 750 millivolts in this embodiment to indicate a threshold into a rich saturation range. Any filtered average value greater in magnitude than the threshold RICHTHR indicates a sustained presence in saturation that will likely drive the catalytic treatment device 28 of FIG. 1 into a low efficiency operating range, as described. Accordingly, if the filtered average is greater than RICHTHR at the step 366, and at least two averages were used in the formation of the filtered average value as determined by comparing RNUMAVG to two at a next step 368, then a rich fault condition is indicated at a next step 370, such as by storing a fault code in controller memory, by illuminating an indicator on a vehicle instrument panel (not shown), by energizing an aural alert means, such as a chime or tone, or by providing any means of indicating or storing a failure of the air/fuel ratio control system that may lead to reduced catalytic treatment efficiency, to support conventional repair or replacement activities. After indicating the failure or fault condition, the interrupt that invoked operation of the routine of FIG. 8, and thus of FIG. 10, is disabled at a step 372 so the diagnostic of FIG. 8 is not executed until the next time the controller 36 is turned on, such as following a vehicle startup operation. The manner of disabling the interrupt may bee that described for the step 254 of FIG. 8. A step 374 is next executed to return to the operations following the step 260 of FIG. 8. Returning to the step 368, if the number of averages used to form the filtered average value as indicated by RNUMAVG is less than two, further analysis is required to accurately diagnose the air/fuel ratio control system and the described step 374 is executed. Likewise, if RICHCNT was not yet incremented to twenty as determined at the step 356 or if the filtered averages were determined to not be greater than RICHTHR at the step 366, the described step 374 is executed to return to the operations of FIG. 8.
The preferred embodiment for the purpose of explaining this invention is not to be taken as limiting or restricting this invention since many modifications may be made through the exercise of ordinary skill in the art without departing from the scope of the invention. | An automotive internal combustion engine air/fuel ratio control system is diagnosed by monitoring the oxygen content of catalytically treated engine exhaust gas for sustained deviations into regions of saturation in which the catalytic treatment device is characterized by low treatment efficiency. The oxygen content of catalytically treated engine exhaust gas is periodically sampled under test conditions and the samples processed into representative values for comparison to a predetermined range. Persistent excursions outside the range indicate a fault condition in which the air/fuel ratio control system operation is not supportive of efficient exhaust gas aftertreatment. | 5 |
FIELD OF THE INVENTION
This invention relates to wire bonder and, more specifically, to a wire bonder having a gas diffuser which reduces the hardness of a free air ball of a conductive wire in order to avoid damage to a bond pad of a semiconductor device and or a circuit pattern of a circuit board and to achieve improved bondability of the conductive wire.
BACKGROUND OF THE INVENTION
Generally, a semiconductor package is fabricated by attaching a semiconductor die to a circuit board (die bonding). The circuit board and the semiconductor die may then be electrically connected. In accordance with one method, conductive wires (wire bonding) may be used to electrically connect the circuit board and the semiconductor die. The semiconductor die and the conductive wires may then be encapsulated by an encapsulant (encapsulation).
The wire bonding process may includes the following steps: creating a free air ball (FAB) at one end of a conductive wire protruding downwardly through a lower end of a capillary using an electric flame-off (ER)) tip; moving the capillary toward a bond pad of a semiconductor die and primarily bonding the FAB to the bond pad (ball bonding); and moving the capillary toward a pattern of a circuit board and secondarily bonding the distal end of the conductive wire to the pattern (stitch bonding).
The conductive wire may be made of gold. In some cases, the gold wire is currently replaced by a cheaper copper wire. Since the Vickers hardness of the copper wire and its FAB is relatively high compared to that of the gold wire and its FAB, the use of the copper wire increases the probability of damage to the bond pad of the semiconductor die. That is, the bond pad is apt to crack when the relatively hard FAB of the copper wire is brought into close contact with the bond pad. Particularly, when the copper wire is applied to a low-dielectric constant (k) semiconductor device, weak active regions of the semiconductor device may lead to damage or cracking of the semiconductor device. Although the price of a copper wire is about one hundredth of that of a gold wire, the relatively high hardness of the copper wire increases the number of defects during wire bonding.
Therefore, a need existed to provide a system and method to overcome the above problem. The system and method would provide a wire bonder which reduces the hardness of a free air ball of a conductive wire.
SUMMARY OF THE INVENTION
A wire bonder has a capillary through which a wire passes. A discharge tip is positioned near a bottom section of the capillary and provides a flame to a distal end of the wire. A gas diffuser is positioned beside the capillary to diffuse a heated gas to the distal end of the wire.
A wire bonding method comprises: diffusing a heated gas to a conductive wire positioned at a lower end of a capillary; and providing an electric flame to a distal end of the conductive wire to create a free air ball.
A wire bonder has a capillary through which a conductive wire passes. A heater is positioned above the capillary to heat the conductive wire.
The present invention is best understood by reference to the following detailed description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view illustrating the construction of a wire bonder according to an embodiment of the present invention;
FIG. 2 is a schematic cross-sectional view illustrating a hot gas diffuser of a wire bonder according to the present invention;
FIG. 3 is a flow chart illustrating a wire bonding method of the present invention;
FIGS. 4A through 4E are schematic views sequentially illustrating the individual steps of a wire bonding method according to the present invention;
FIGS. 5A and 5B are graphs showing changes in ball shear and stitch pull with increasing temperature of a conductive wire after wire bonding in accordance with the present invention, respectively;
FIG. 6 is a schematic view illustrating the construction of a wire bonder according to a further embodiment of the present invention; and
FIG. 7 is a schematic view illustrating the construction of a wire bonder according to another embodiment of the present invention.
Common reference numerals are used throughout the drawings and detailed description to indicate like elements.
DETAILED DESCRIPTION
Referring to FIG. 1 , a schematic view of a wire bonder 100 according to one embodiment of the present invention is shown. As illustrated in FIG. 1 , the wire bonder 100 comprises a capillary 110 , an electric flame-off tip 120 , and a gas diffuser 130 .
The capillary 110 has a through-hole therein through which a conductive wire 140 passes. A transducer 150 is coupled to the capillary 110 to deliver ultrasonic energy to the capillary 110 . A clamp 160 is positioned above the capillary 110 to clamp or unclamp the conductive wire 140 during wire bonding.
A heater block 171 is installed below the capillary 110 . A circuit board 172 is securely mounted on the heater block 171 , and a semiconductor die 173 is attached to the circuit board 172 . The heater block 171 provides heat to a free air ball to be created at the distal end of the conductive wire 140 . The circuit board 172 is brought into close contact with the heater block 171 by a clamp 174 .
The electric flame-off tip 120 is installed beside the capillary 110 . The electric flame-off tip 120 provides an electric flame to the distal end of the conductive wire 140 positioned at the lower end of the capillary 110 to create a free air ball. That is, the electric flame-off tip 120 induces the creation of a free air ball at the distal end of the conductive wire 140 to enable ball bonding of the conductive wire 140 .
The gas diffuser 130 is installed beside the capillary 110 opposite to the electric flame-off tip 120 . The gas diffuser 130 supplies a hot forming gas to the conductive wire 140 during the wire bonding process. In accordance with one embodiment, the gas diffuser 130 supplies a hot forming gas around 25° C.-300° C. to the conductive wire 140 . If the temperature of the hot forming gas is lower than 25° C., a decrease in the hardness of a free air ball of the conductive wire 140 is insufficient and an improvement in the bondability of the conductive wire 140 is not significant. Meanwhile, a temperature higher than 300° C. in the present embodiment is substantially difficult to achieve in view of the characteristics of a heater, which will be described below.
In accordance with one embodiment, the conductive wire 140 may be made of a conductive material selected from, but not limited to, copper, gold, aluminum and equivalents thereof. The forming gas may be selected from nitrogen, hydrogen, air, mixtures thereof and equivalents thereof, but is not limited thereto. The listing of the above is given as an example and should not be seen to limit the scope of the present invention.
In the present embodiment, the hot forming gas is diffused from the gas diffuser 130 to the free air ball of the conductive wire 140 at the lower end of the capillary 110 to reduce the hardness of the free air ball. Therefore, the wire bonder can avoid damage to a bond pad of the semiconductor die 173 or a circuit pattern of the circuit board 172 and can achieve improved bondability of the conductive wire 140 .
In addition, direct supply of the hot forming gas to the free air ball of the conductive wire 140 eliminates the need for an excessive increase in the temperature of the heater block 171 . That is, there is no need for raising the temperature of the heater block 171 to heat the free air ball of the conductive wire 140 . Excessive heating of the heater block 171 has a bad influence on the circuit board 172 or the semiconductor die 173 .
Referring to FIG. 2 , a schematic cross-sectional view of a hot gas diffuser 130 of a wire bonder according to one embodiment is shown. As illustrated in FIG. 2 , the gas diffuser 130 includes a body 131 , a heater 136 , a power supply 137 , and a forming gas supply 138 .
The body 131 has an inner diameter surface 132 so as to define a space therein along the lengthwise direction thereof, a forming gas inlet port 134 in flow communication with the space defined by the inner diameter surface 132 at an upper end thereof, and a forming gas outlet port 135 in flow communication with the space defined by the inner diameter surface 132 at a lower end thereof. In accordance with one embodiment, the body 131 has an inner diameter surface 132 that defines a channel formed in an interior of and running a length of the body 131 .
A helical groove 133 is formed extending from the forming gas inlet port 134 to the forming gas outlet port 135 on the inner diameter surface 132 of the body 131 . With this configuration, a forming gas is introduced into the body 131 through the forming gas inlet port 134 , flows downwardly along the groove 133 on the inner diameter surface 132 to reach the forming gas outlet port 135 , and is sprayed out through the forming gas outlet port 135 . That is, the helical groove 133 serves to allow the forming gas to stay in the space of the body 131 as long as possible.
The heater 136 is inserted into the space defined by the inner diameter surface 132 of the body 131 . That is, the heater 136 is inserted into the space along the lengthwise direction of the body 131 . A gap is formed between the heater 136 and the inner diameter surface 132 of the body 131 to allow the forming gas to flow downwardly along the helical groove 133 . The heater 136 may take on a plurality of different configurations. There is no restriction on the structure and shape of the heater 136 . For example, the heater 136 may consist of a heating coil and a ceramic material surrounding the heating coil, and may be in the shape of a bar. The forming gas can be typically heated to 25-300° C. by the heater 136 . As a result, the temperature of the hot forming gas sprayed through the periphery of the heater 136 reaches 25-300° C.
The power supply 137 applies power to the heater 136 . The power supply 137 may be a direct or alternating current power supply.
The forming gas supply 138 is connected to the forming gas inlet port 134 of the body 131 to supply a forming gas at constant flow and pressure to the body 131 . The forming gas supplied from the forming gas supply 138 may be at different temperatures (including room temperature).
Due to this construction, the forming gas supplied from the forming gas supply 138 is heated to around 25-300° C. in the gas diffuser 130 . The hot forming gas is sprayed toward the free air ball of the conductive wire 140 ( FIG. 1 ) at the lower end of the capillary 110 ( FIG. 1 ).
The heating and spraying of the forming gas are explained in more detail below. First, a forming gas at room temperature is introduced into the body 131 through the forming gas inlet port 134 of the body 131 . Then, the heater 136 is operated by power applied from the power supply 137 . The forming gas introduced into the body 131 is heated to about 25-300° C. by the heater 136 while flowing downwardly along the helical groove 130 formed on the inner diameter surface 132 . Finally, the hot forming gas is sprayed out through the forming gas outlet port 135 of the body 131 .
Referring to FIG. 3 , a flow chart of a wire bonding method of the present invention is shown. As illustrated in FIG. 3 , the wire bonding method of the present invention comprises the following steps: diffusion of a hot forming gas (S 1 ), formation of a free air ball (S 2 ), ball bonding (S 3 ), looping (S 4 ) and stitch bonding (S 5 ).
Referring to FIGS. 4A through 4E , there are sequentially illustrated schematic views for explaining the individual steps of the wire bonding method according to the present invention. As illustrated in FIG. 4A , and in step S 1 of FIG. 3 , a hot forming gas is diffused to the conductive wire 140 positioned at the lower end of the capillary 110 , through which the conductive wire 140 passes. In accordance with one embodiment, a hot forming gas at 25° C.-300° C. is diffused to the conductive wire 140 by heating a forming gas in the gas diffuser 130 .
In the case where the conductive wire 140 is made of copper or aluminum, nitrogen, or a mixed gas of nitrogen and hydrogen gases is desirable as the hot forming gas. The reason for the use of the nitrogen/hydrogen mixed gas is because the nitrogen gas protects a free air ball from oxidation and the hydrogen gas reduces the free air ball while protecting the free air ball from oxidation. In accordance with one embodiment, the nitrogen and hydrogen gases are substantially mixed in a ratio of 95:5.
Alternatively, in the case where the conductive wire 140 is made of gold, nitrogen or air is desirable as the hot forming gas. That is, since the free air ball of the gold wire does not substantially undergo oxidation, the use of hydrogen gas as the hot forming gas is excluded. Further, the hot forming gas may be continuously diffused to the conductive wire 140 without being stopped throughout steps S 2 , S 3 , S 4 and S 5 of FIG. 3 .
As illustrated in FIG. 4B , and in step S 2 of FIG. 3 , the electric flame-off tip 120 provides an electric flame to the distal end of the conductive wire 140 positioned at the lower end of the capillary 110 , through which the conductive wire 140 passes, to create a free air ball 141 . That is, the free air ball 141 is created by applying power to the electric flame-off tip 120 to deliver a flame from the electric flame-off tip 120 to the distal end of the conductive wire 140 positioned at the lower end of the capillary 110 . It is known that the free air ball 141 is created at a temperature of about 1,000° C. At this time, the hot forming gas is still diffused to the free air ball 141 so as to maintain the free air ball 141 at the same temperature as the hot forming gas.
As illustrated in FIG. 4C , and in step S 3 of FIG. 3 , the free air ball of the conductive wire 140 is primarily bonded to the semiconductor die 173 (ball bonding). Specifically, the capillary 110 descends toward the semiconductor die 173 , and then ultrasonic energy is delivered to the capillary 110 in a state where the free air ball is pressed against a bond pad of the semiconductor die 173 to bond the free air ball of the conductive wire 140 to the bond pad of the semiconductor die 173 .
As illustrated in FIG. 4D , and in step S 4 of FIG. 3 , the capillary 110 moves toward the circuit board 172 (looping).
As illustrated in FIG. 4E , and in step S 5 of FIG. 3 , the distal end of the conductive wire 140 is secondarily bonded to the circuit board 172 (stitch bonding). Specifically, the capillary 110 is moved toward the circuit board 172 , and then ultrasonic energy is delivered to the capillary 100 in a state in which the distal end of the conductive wire 140 is pressed against a circuit pattern of the circuit board 172 to bond the distal end of the conductive wire 140 to the circuit pattern.
The following table shows changes in the hardness of the copper wire and the free air ball. The hardness tests were conducted at various temperatures between 100 to 250° C. From the results in the table, it can be confirmed that the copper wire had a hardness of 65 to 75 Hv at room temperature, 31 Hv at 100° C. and 20 Hv at 250° C. In addition, the free air ball was found to have a hardness of 45 to 55 Hv at room temperature. These results indicate that the free air ball will have lower hardness values at 100° C. and 250° C. than the hardness at room temperature.
Cu wire
Wire diameter: 1.0 mil
Room Temp.
100° C.
250° C.
Hardness (Hv)
FAB
45-55
Wire
65-75
31
20
Referring to FIGS. 5A and 5B , there are shown changes in ball shear and stitch pull versus temperature of the conductive wire 140 after wire bonding in accordance with the present invention, respectively. The temperatures of the hot forming gas supplied by the gas diffuser were varied from about 90° C. to about 230° C. while maintaining the temperature of the heater block at 100° C.
The x- and y-axis in FIG. 5A show temperature and ball shear, respectively. The ball shear of the conductive wire was determined by measuring a force applied when the ball bonding region of the conductive wire formed on the bond pad was pushed in the lateral direction using a tool equipped with a sensor until the ball bonding region was separated from the bond pad. As illustrated in FIG. 5A , the ball shear increased by about 0.9 gr whenever the temperature of the hot forming gas was raised by about 10° C. In conclusion, the supply of the hot forming gas during wire bonding increased the ball shear of the conductive wire in the ball bonding region with increasing temperature.
Referring to FIG. 5B , the x- and y-axis in FIG. 5B show temperature and stitch pull, respectively. The stitch pull of the conductive wire was determined by measuring a force applied when a hook equipped with a sensor was tied to the conductive wire after wire bonding and was then raised at a predetermined speed until the wire was cut. As illustrated in FIG. 5B , the stitch pull increased by about 0.02 gr whenever the temperature of the hot forming gas was raised by about 10° C. In conclusion, the supply of the hot forming gas during wire bonding increased the stitch pull of the conductive wire with increasing temperature.
Referring to FIG. 6 , a schematic view of a wire bonder 200 according to a further embodiment of the present invention is shown. As illustrated in FIG. 6 , the wire bonder 200 comprises a capillary 110 , an electric flame-off tip 120 and a heater 210 .
A conductive wire 140 penetrates the capillary 110 . A transducer 150 is coupled to the capillary 110 to deliver ultrasonic energy to the capillary 110 . A clamp 160 is installed above the capillary 110 to clamp or unclamp the conductive wire 140 . A heater block 171 , a circuit board 172 , a semiconductor die 173 and a clamp 174 pressing the circuit board 172 are installed below the capillary 110 .
The heater 210 is positioned between the clamp 160 and the capillary 110 and has a substantially circular tubular shape. The conductive wire 140 penetrates the heater 210 and is heated by the heater 210 . The heater 210 may take on a plurality of forms. For example, the heater 210 may be a thermoelectric element. However, this is given as an example and should not be seen to limit the scope of the present invention. A power supply unit is connected to the heater 210 to supply power to the heater 210 . In the present embodiment, the heater 210 provides a temperature of 25 to 300° C. to the conductive wire 140 . As a result, the heat energy provided by the heater 210 enables effective wire bonding and improves the bondability of the conductive wire.
Referring to FIG. 7 , a schematic view of a wire bonder 300 according to another embodiment of the present invention is shown. As illustrated in FIG. 7 , the wire bonder 300 may comprise a capillary 110 , a gas diffuser 130 for supplying a hot forming gas to a free air ball created at the lower end of the capillary 110 , and a heater 210 positioned above the capillary 110 to heat a conductive wire 140 . Due to this construction, the hot forming gas is directly diffused to the free air ball to improve the ball shear or stitch pull of the conductive wire 140 . In addition, the conductive wire 140 penetrating the capillary 110 is preheated to achieve improved bondability upon wire bonding.
This disclosure provides exemplary embodiments of the present invention. The scope of the present invention is not limited by these exemplary embodiments. Numerous variations, whether explicitly provided for by the specification or implied by the specification, such as variations in structure, dimension, type of material and manufacturing process may be implemented by one of skill in the art in view of this disclosure. | A wire bonder has a capillary through which a wire passes. A discharge tip is positioned near a bottom section of the capillary and provides a flame to a distal end of the wire. A gas diffuser is positioned beside the capillary to diffuse a heated gas to the distal end of the wire. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 11/870,691, filed on Oct. 11, 2007 and claims priority from and the benefit of Korean Patent Application No. 10-2006-0099498, filed on Oct. 12, 2006, both of which are hereby incorporated by reference for all purposes as if fully set forth herein.
BACKGROUND OF THE INVENTION
[0002] 1 Field
[0003] The present disclosure relates to a backlight assembly and a liquid crystal display device including the same. More particularly, the present disclosure relates to a backlight assembly and a liquid crystal display device including the backlight assembly, where the liquid crystal display device is slim, lightweight, and requires low manufacturing costs because the device integrates a bottom chassis and a lamp cover.
[0004] 2. Discussion of the Background
[0005] Liquid crystal display (“LCD”) devices have increasingly been used in a broad range of applications because LCDs are lightweight, compact, and require low power consumption. An LCD device includes an LCD module and a driving circuit for driving the LCD module.
[0006] The LCD module includes an LCD panel including liquid crystal cells arranged in a matrix format between two transparent substrates, and a backlight assembly which emits light to the LCD panel.
[0007] The backlight assembly includes a lamp for emitting light to the LCD panel, a lamp housing for covering the lamp, a light guide plate for guiding incident light from the lamp toward the LCD panel, a reflection sheet located on the inner surface of the light guide plate, and a plurality of optical sheets stacked on the light guide plate.
[0008] Although there are various types of backlight assemblies, a backlight assembly including a lamp cover for seating the lamp is commonly used. However, stacking the lamp cover on the backlight assembly increases the thickness of the LCD device. This structure increases the LCD device's manufacturing costs because the LCD device includes the lamp cover for preventing light emitted from the lamp from proceeding thereunder and a reflection material coated on the lamp cover for guiding the light toward the light guide plate.
SUMMARY OF THE INVENTION
[0009] The present disclosure provides a backlight assembly and an LCD device including the backlight assembly, where the liquid crystal display device is slim, lightweight, and requires low manufacturing costs because the device integrates a bottom chassis and a lamp cover.
[0010] Additional features of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention.
[0011] The present application discloses a backlight assembly, comprising: a light source; a light guide plate; and a bottom chassis comprising an accommodating portion, a light source cover configured to accommodate the light source, and first and second sidewalls, the accommodating portion comprising a first accommodating portion and a second accommodating portion configured to separatably engage with each other, wherein the light source cover is formed on a first edge of the first accommodating portion, the first sidewall is formed on a second edge of the first accommodating portion, and the second sidewall is formed on an edge of the second accommodating portion.
[0012] The present application also discloses a liquid crystal display device, comprising: a liquid crystal display panel; a driving circuit to drive the liquid crystal display panel; a light source to provide the liquid crystal display panel with light; a light guide plate to guide the light emitted from the light source toward the liquid crystal display panel; and a bottom chassis comprising an accommodating portion, a light source cover configured to accommodate the light source, and first and second sidewalls, the accommodating portion comprising a first accommodating portion and a second accommodating portion configured to separatably engage with each other; and a top chassis enclosing edge portions of the liquid crystal display panel and covering side surfaces of the bottom chassis, wherein the light source cover is formed on a first edge of the first accommodating portion, the first sidewall is formed on a second edge of the first accommodating portion, and the second sidewall is formed on an edge of the second accommodating portion.
[0013] The present application discloses a backlight assembly, comprising: a lamp; a light guide plate configured to guide light emitted from the lamp; an optical sheet disposed on the light guide plate; and a chassis configured to accommodate the lamp, the light guide plate, and the optical sheet, the chassis comprising a first chassis and a second chassis, wherein the first chassis and the second chassis are configured to be separatably coupled together such that an upper surface of the first chassis is coplanar with an upper surface of the second chassis, the coplanar upper surfaces forming an accommodating portion, and wherein the light source cover is formed on a first edge of the first chassis, the first sidewall is formed on a second edge of the first chassis, and the second sidewall is formed on an edge of the second chassis.
[0014] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The accompanying drawings, which are included to provide a further understanding of the invention are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the description serve to explain the principles of the invention.
[0016] FIG. 1 is an exploded perspective view showing an LCD according to an exemplary embodiment of the present invention.
[0017] FIG. 2 is a cross-sectional view taken along line I-I′ of FIG. 1 .
[0018] FIG. 3 is a graphical view showing a first bottom chassis engaged with a second bottom chassis of FIG. 1 .
[0019] FIG. 4A , FIG. 4B , FIG. 5A , FIG. 5B , FIG. 5C , FIG. 5D , FIG. 6A and FIG. 6B are graphical views showing the first bottom chassis and the second bottom chassis of FIG. 3 according to exemplary embodiments of the present invention.
[0020] FIG. 7 is a graphical view showing a method of engaging the first bottom chassis and the second bottom chassis shown in FIG. 4A and FIG. 4B .
[0021] FIG. 8 is a perspective view showing a backlight assembly shown in FIG. 1 .
[0022] FIG. 9 is a cross-sectional view of the LCD device including a lamp cover and a mold frame according to an exemplary embodiment of the present invention.
[0023] FIG. 10 is a perspective view showing an LCD device according to an exemplary embodiment of the present invention.
[0024] FIG. 11 is a graphical view showing a reflection sheet according to an exemplary embodiment of the present invention.
[0025] FIG. 12 is a cross-sectional view taken along line II-II′ of FIG. 10 .
[0026] FIG. 13 is a graphical view showing a bottom chassis according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0027] Various exemplary embodiments of the invention are described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure is thorough, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the size and relative size of layers and regions may be exaggerated for clarity. Like reference numerals in the drawings denote like elements.
[0028] It will be understood that when an element such as a layer, film, region or substrate is referred to as being “on”, “connected to”, or “coupled to” another element or layer, it can be directly on, directly connected to, or directly coupled to the other element or layer, or intervening elements or layers may also be present. In contrast, when an element is referred to as being “directly on”, “directly connected to”, or “directly coupled to” another element or layer, there are no intervening elements or layers present.
[0029] FIG. 1 is an exploded perspective view showing an LCD device according to an exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line I-I′ of FIG. 1 .
[0030] The LCD device shown in FIG. 1 and FIG. 2 includes an LCD panel 120 , a backlight assembly 170 , a mold frame 110 , a top chassis 100 , and a bottom chassis 90 divided into a first bottom chassis 92 and a second bottom chassis 94 .
[0031] The LCD panel 120 includes a thin film transistor (“TFT”) substrate 124 , and a color filter substrate 122 facing the TFT substrate 124 . Liquid crystals (not shown) are disposed between the TFT substrate 124 and the color filter substrate 122 . The LCD panel 120 displays an image by controlling the light transmissivity of the liquid crystals using TFTs switching element that are arranged in a matrix format. The color filter substrate 122 includes RGB color filters thereon for generating a desired color. Therefore, light transmitted through the liquid crystals is expressed as a desired color through the RGB color filters for displaying an image.
[0032] The top chassis 100 covers an upper edge portion of the LCD panel 120 , and side surfaces of the top chassis 100 are formed to cover side surfaces of the mold frame 110 and the bottom chassis 90 .
[0033] The mold frame 110 accommodates the LCD panel 120 and the backlight assembly 170 to prevent movement thereof and to absorb an outside impact on the LCD panel 120 and the backlight assembly 170 . The mold frame 110 may be formed of synthetic resins or plastics to be insulated from a driving circuit.
[0034] The backlight assembly 170 includes a lamp 182 , a reflection sheet 190 , a light guide plate 160 , a diffusion sheet 176 , a prism sheet 174 , and a protection sheet 172 and supplies light to the LCD panel 120 .
[0035] The lamp 182 may be comprised of at least one cold cathode fluorescence lamp having a bar shape for generating light, a lamp electrode line 183 connected to both ends of the lamp 182 for applying a driving voltage. Alternatively, the at least one cold cathode fluorescent lamp may be replace with a plurality of light emitting diodes for generating light. The lamp 182 may be fixed by a lamp holder 184 .
[0036] The sheets include the diffusion sheet 176 , the prism sheet 174 , and the protection sheet 172 . The diffusion sheet 176 and the prism sheet 174 are combined with two or three sheets, and diffuse and converge light emitted from the light guide plate 182 , improving brightness and a viewing angle of the LCD device. The protection sheet 172 may be stacked on the diffusion sheet 176 or the prism sheet 174 for protecting sheets sensitive to dust or scratching and for preventing movement of the sheets and the backlight assembly 170 .
[0037] The light guide plate 160 uniformly distributes light emitted from the lamp 182 across the entire surface of the light guide plate 160 , and then guides the light toward the LCD panel 120 . For doing so, the light guide plate 160 may be formed of a transparent, thermal resistant polycarbonate, or a transparent acryl resin with a high refraction index. The light guide plate 160 has a protrusion portion 162 formed on at least one side surface thereof as shown in FIG. 8 . The protrusion portion 162 of the light guide plate 160 is fixed to a groove 164 of an inner sidewall 314 of the bottom chassis 90 .
[0038] Referring back to FIG. 1 , the reflection sheet 190 reflects light emitted from a lower portion of the light guide plate 160 back toward the light guide plate 160 . For doing so, the reflection sheet 190 may have a basic material coated with a highly reflective material. The basic material may include aluminum (Al), polyethylene terephthalate (PET), etc. and the reflective material may include silver (Ag), titanium (Ti), etc. The bottom chassis 90 is divided into the first bottom chassis 92 and the second bottom chassis 94 .
[0039] FIG. 3 shows a graphical view of the first bottom chassis 92 engaged with the second bottom chassis 94 of FIG. 1 . The first bottom chassis 92 includes a first accommodating portion 192 , a first inner sidewall 312 , a first lamp cover 302 , and first and second opening portions 402 and 404 . The second bottom chassis 94 includes a second accommodating portion 194 , a second inner sidewall 314 , a second lamp cover 304 , and third and fourth opening portions 406 and 408 .
[0040] The first bottom chassis 92 and the second bottom chassis 94 are engaged to face each other. The first accommodating portion 192 of the first bottom chassis 92 and the second accommodating portion 194 of the second bottom chassis 94 provide an accommodating space, which accommodates the light guide plate 160 , the optical sheets 172 , 174 and 176 , and the reflection sheet 190 . The first accommodating portion 192 and the second accommodating portion 194 are formed to be symmetrical to each other, and their facing surfaces may be formed in an ‘L’ shape and a reverse ‘L’ shape.
[0041] FIG. 4A and FIG. 4B show graphical views of exemplary embodiments of the first bottom chassis 92 and the second bottom chassis 94 of FIG. 3 , respectively.
[0042] Referring to FIG. 4A and FIG. 4B , the first bottom chassis 92 includes a first mounting portion 202 formed to overlap and engage an area of the second accommodating portion 194 , a first mounting hole 502 , and a first accommodating hole 512 . The second bottom chassis 94 includes a second mounting portion 204 formed to overlap and engage an area of the first accommodating portion 192 , a second accommodating hole 504 , and a second mounting hole 514 . The first accommodating portion 192 forms the first mounting portion 202 such that a stepped portion is formed at an area in contact with the second accommodating portion 194 .
[0043] The first mounting portion 202 is formed from the first accommodating portion 192 in a single body and second mounting portion 204 is formed from the second accommodating portion 194 in a single body.
[0044] When the first bottom chassis 92 engages the second bottom chassis 94 , the first mounting portion 202 engages and overlaps the second accommodating portion 194 at an area equivalent to the width of the first mounting portion 202 , and the second mounting portion 204 engages and overlaps the first accommodating portion 192 at an area equivalent to the width of the second mounting portion 204 . In this manner, the engagement of the first bottom chassis 92 and the second bottom chassis 94 may prevent light emitted from the lamp 182 from leaking through a gap between the facing surfaces of the first accommodating portion 192 and the second accommodating portion 194 . Further, the intersection and overlapping of the first accommodating portion 192 and the second accommodating portion 194 strengthens the engagement between the first bottom chassis 92 and the second bottom chassis 94 .
[0045] FIG. 5A , FIG. 5B , FIG. 5C and FIG. 5D show graphical views of exemplary embodiments of the first bottom chassis 92 and the second bottom chassis 94 of FIG. 3 , respectively.
[0046] As shown in FIG. 5A and FIG. 5B , a second mounting portion 204 a of the second bottom chassis 94 is formed such that a stepped portion is formed across the entire width of the second bottom chassis 94 and in contact with the first accommodating portion 192 across the entire width of the first bottom chassis 92 . The first accommodating portion 192 is also formed to overlap and engage the second accommodating portion 194 across the entire width of the second bottom chassis 94 . Alternatively, as shown in FIG. 5C and FIG. 5D , the first accommodating portion 192 may form a first mounting portion 202 a to overlap and engage the second accommodating portion 194 across the entire width of the second bottom chassis 94 .
[0047] The first mounting portion 204 a is formed from the first accommodating portion 192 in a single body, and the second mounting portion 202 a is formed from the second accommodating portion 194 in a single body.
[0048] FIG. 6A and FIG. 6B show graphical views of exemplary embodiments of the first bottom chassis 92 and the second bottom chassis 94 of FIG. 3 , respectively.
[0049] As shown in FIG. 6A and FIG. 6B , the first mounting portion 212 is arranged under the first accommodating portion 192 to form a stepped portion and overlaps and engages an area in contact with the second accommodating portion 194 . In other words, the second accommodating portion 194 is mounted on the first mounting portion 212 which partially extends from the first accommodating portion 192 and forms a stepped portion by a constant distance. Likewise, the second mounting portion 214 partially extends from the second accommodating portion 194 and forms a stepped portion by a constant distance. The first mounting portion 212 is formed from the first accommodating portion 192 in a single body, and the second mounting portion 214 is formed from the second accommodating portion 194 in a single body.
[0050] Alternatively, the first accommodating portion 192 includes a first inner sidewall 322 perpendicular to the first accommodating portion 192 , and the second accommodating portion 194 includes a second inner sidewall 324 perpendicular to the second accommodating portion 194 . The first inner sidewall 322 includes sidewalls 322 a and 322 b formed at both sides of the first accommodating portion 192 , and the second inner sidewall 324 includes sidewalls 324 a and 324 b formed at the both sides of the second accommodating portion 194 .
[0051] As shown in FIG. 7 , the overlap and engagement of the first accommodating portion 192 to the second accommodating portion 194 may be strengthened by using screws 506 and 507 . A screwing method will be described with reference to FIG. 4A and FIG. 4B as previously described above. The first mounting hole 502 formed in the first mounting portion 202 and the second accommodating hole 504 formed at a position corresponding to the first mounting hole 502 are aligned and secured by the first screw 506 . The second mounting hole 514 formed in the second mounting portion 204 and the first accommodating hole 512 formed at a position corresponding to the second mounting hole 514 are aligned and secured by the second screw 507 . Alternatively, a plurality of screws may be used at desired positions for improving a securing strength. In this way, the overlap and engagement of the first accommodating portion 192 and the second accommodating portion 194 may prevent light from leaking toward the lower portion of the light guide plate 160 . Further, the light guide plate 160 , the optical sheets 172 , 174 , and 176 , and the reflection sheets 186 and 188 may be more easily accommodated by dividing the bottom chassis 90 into the first bottom chassis 92 and the second bottom chassis 94 .
[0052] As shown in FIG. 8 , the first inner sidewall 312 accommodates the light guide plate 160 , the optical sheets 172 , 174 , and 176 , and the reflection sheets 186 and 188 . The light guide plate 160 is fixed by the first inner sidewall 312 . The groove 164 is formed at a position corresponding to the protrusion portion 162 of the light guide plate 160 in the first inner sidewall 312 perpendicular to the first accommodating portion 192 (refer to FIG. 3 , FIG. 4A and FIG. 4B ). Accordingly, by combining the groove 164 of the first inner sidewall 312 with the protrusion 162 of the light guide plate 160 , the securing strength of the light guide plate 160 and the bottom chassis 90 may be improved. Alternatively, the protrusion portion 162 may be formed on the second inner sidewall 314 , and the groove 164 may be formed on the light guide plate 160 at a position corresponding to the protrusion portion 162 Like the first inner sidewall 312 , the second inner sidewall 314 may have a groove 164 or a hole into which the protrusion portion 162 of the light guide plate 160 is inserted.
[0053] The first lamp cover 302 and the second lamp cover 304 extend from one side surfaces of the first bottom chassis 92 and the second bottom chassis 94 , respectively, and are bent to enclose a lamp reflection layer 185 and the lamp 182 fixed by the lamp holder 184 . The first lamp cover 302 and the second lamp cover 304 are formed in a ‘C’ shape, for example, to accommodate the lamp 182 and the lamp reflection layer 185 . Accordingly, the first lamp cover 302 and the second lamp cover 304 accommodate the lamp 182 . The lamp electrode line 183 for applying a driving voltage to the lamp 182 is exposed to an external circuit and is disposed between the first and second lamp covers 302 and 304 and the mold frame 110 . More specifically, as shown in FIG. 2 , the lamp electrode line 183 disposed between the first lamp cover 302 and the mold frame 110 is supported and secured by bending side surface of the first lamp cover 302 . Further, as shown in FIG. 9 , when the side surface of the first lamp cover 302 is flat, a protrusion portion 110 a of the mold frame 110 is formed between the first lamp cover 302 and the mold frame 110 to support and fix the lamp electrode line 183 . Meanwhile, the first lamp cover 302 may be formed of a material with high reflectivity for reflecting light generated from the lamp 182 toward the light guide plate 160 , thereby improving light efficiency of the LCD device.
[0054] The lamp reflection layer 185 may be formed of a material with high reflectivity on an inner surface of the first lamp cover 302 . The lamp reflection layer 185 reflects light emitted from the lamp 182 toward an incident surface of the light guide plate 160 , thus improving light efficiency. The lamp reflection layer 185 is attached to the inner surface of the first lamp cover 302 by an adhesive. Alternatively, the lamp reflection layer 185 may be coated with a reflective material such as Ag or Al to enclose the inner surface of the first lamp cover 302 . The second lamp cover 304 has the same structures as the first lamp cover 302 . Therefore, repetitive descriptions will be omitted.
[0055] As shown in FIG. 3 and FIG. 8 , the first to fourth opening portions 402 , 404 , 406 and 408 allow the lamp electrode line 183 connected to the lamp 182 to be exposed to an external circuit. The first opening portion 402 is exposed by a constant distance at an area in contact with the first lamp cover 302 and the first inner sidewall 312 ; the second opening portion 404 is exposed by a constant distance at an area in contact with the first lamp cover 302 and the second inner sidewall 314 ; the third opening portion 406 is exposed by a constant distance at an area in contact with the second lamp cover 304 and the second inner sidewall 314 ; and the fourth opening portion 408 is exposed by a constant distance at an area in contact with the second lamp cover 304 and the first inner sidewall 312 . The lamp electrode lines 183 connected to the lamp 182 inserted into the first lamp cover 302 are exposed through the first opening portion 402 and the second opening portion 404 . The lamp electrode lines connected to the lamp 182 inserted into the second lamp cover 304 are exposed at the third opening portion 406 and the fourth opening portion 408 . Accordingly, the lamp electrode lines 183 may be easily moved and connected to an external circuit.
[0056] FIG. 10 and FIG. 12 show a perspective view and a cross-sectional view, respectively, of the LCD device according to another exemplary embodiment of the present invention.
[0057] FIG. 10 and FIG. 12 are the same configurations as those of FIG. 1 and FIG. 2 , except for the addition of a reflection sheet. Accordingly, any repetitive descriptions will be omitted.
[0058] The reflection sheet includes first and second reflection sheets 186 and 188 where the reflection sheet reflects light emitted to the lower portion of the light guide plate 160 back toward the light guide plate 160 . For doing so, the first and second reflection sheets 186 and 188 may have a basic material coated with a material with high reflectivity. The basic material may be Al, PET, etc. and the reflective material may be Ag, Ti, etc.
[0059] The first reflection sheet 186 is bent into a shape similar to the second lamp cover 304 and the second reflection sheet 188 is bent into a shape similar to the first lamp cover 302 . The first reflection sheet 186 and the second reflection sheet 188 are stacked on the first lamp cover 302 and the second lamp cover 304 and reflect light generated from the lamp 182 back toward the light guide plate 160 , thus improving light efficiency. Meanwhile, as shown in FIG. 11 , a single reflection sheet 187 may be formed to have both ends 84 and 86 bent into a shape similar to the first lamp cover 302 and the second lamp cover 304 and to enclose the lamp 182 .
[0060] FIG. 13 shows a perspective view of a bottom chassis according to an exemplary embodiment of the present invention.
[0061] As shown in FIG. 13 , the bottom chassis comprises an accommodating portion 292 , an inner sidewall 332 , first and second lamp covers 322 and 324 , and a light guide plate inserting portion 334 . The accommodating portion 292 and the inner sidewall 332 provide an accommodating space which may accommodate the light guide plate 160 , the optical sheets 172 , 174 , and 176 , and the reflection sheet 190 . The first and second lamp covers 322 and 324 extend from both sides of the bottom chassis and are bent in a shape to enclose the lamp 182 fixed by the lamp holder 184 and the lamp reflection layer 185 . The first and second lamp covers 322 and 324 are formed in a ‘C’ shape to accommodate the lamp 182 and the lamp reflection layer 185 in a ‘C’ shape. The light guide plate inserting portion 334 is formed to provide an open area facing the inner sidewall 332 . Because the area corresponding to the sidewall 332 of the bottom chassis is open, the light guide plate 160 , the optical sheets 172 , 174 , and 176 , and the reflection sheet 190 may be easily accommodated.
[0062] As described above, the backlight assembly and the LCD device including the backlight assembly according to the present invention enclose the lamp by bending both sides of the bottom chassis and dividing the bottom chassis into the first and second bottom chassis. Accordingly, since an additional lamp cover is unnecessary, the present invention may reduce manufacturing costs and provide a slim, lightweight LCD device.
[0063] Although exemplary 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 taught herein, which may appear to those skilled in the present art, will still fall within the spirit and scope of the present invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. | Provided is a backlight assembly and a liquid crystal display including: a light source; a light guide plate; and a bottom chassis comprising an accommodating portion, a light source cover configured to accommodate the light source, a first sidewall, and a second sidewall, the accommodating portion comprising a first accommodating portion and a second accommodating portion detachably coupled with each other, wherein the light source cover is formed on a first edge of the first accommodating portion, the first sidewall is formed on a second edge of the first accommodating portion, and the second sidewall is formed on an edge of the second accommodating portion. | 6 |
This application claims the benefit of U.S. Provisional Application No. 60/788,714 filed Apr. 4, 2006, which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD OF THE INVENTION
The present invention relates generally to the field of treatment of wastewater and process water, more specifically, to the reduction in the level of ammonia and organic ammonia compounds in wastewater and process water, regardless of source.
BACKGROUND OF THE INVENTION
Human and animal waste is the primary source of nitrogen in most wastewater discharges. In addition, certain process waters, including but not limited to industrial process waters, contain significant amounts of nitrogen compounds. Wastewater containing nitrogen compounds such as ammonia; organic nitrogen, nitrates, and nitrites that contaminate ground and surface water resources are a major concern in a world facing potable water shortages. Traditional wastewater systems do little or nothing to reduce the level of nitrogen in the released wastewater. No low-cost technology is available to directly remove ammonia from wastewater. Release of these nitrogen compounds to environmental surface water, or especially ground water, is to be avoided. In addition, the removal of nitrogen compounds from certain processes using this method may be advantageous.
Existing systems of wastewater treatment are limited to treating wastewater with bacterial digestion, oxidation, settling, and disinfection (usually using chlorination). More advanced methods, such as ozone and ultraviolet radiation, also are used to treat water and wastewater. There are no existing systems in which wastewater containing ammonia is treated to directly remove ammonia from the water. Existing systems discuss sterilization, oxidation, and biological systems but not electro-chemical technologies.
It is known to use of ozone alone to sterilize water and/or treat the organic content water. For example, U.S. Pat. No. 4,007,120 issued to Bowen, and entitled “Oxidation and ozonation chamber”, describes the use of ozone to treat and disinfect water. U.S. Pat. No. 4,053,399 issued to Donnelly, et al. and entitled “Method and system for waste treatment”, describes the use of ozone to oxidize and disinfect wastewater. U.S. Pat. No. 4,176,061 issued to Stopka, and entitled “Apparatus and method for treatment of fluid with ozone”, describes the use of ozone in the form of micro-bubbles to oxidize and to disinfect wastewater. U.S. Pat. No. 4,255,257 issued to Greiner, et al. and entitled “Process for the treatment of water”, describes the use of pressurized ozone to treat water. U.S. Pat. No. 4,545,716 issued to Boeve, and entitled “Method of producing ultrapure, pyrogen-free water”, describes the use of highly-concentrated, substantially-pure ozone to treat deionized water. U.S. Pat. No. 4,572,821 issued to Brodard, et al. and entitled “Apparatus for dissolving ozone in a fluid”, describes the use of pressurized ozone to treat water. U.S. Pat. No. 5,130,032 issued to Sartori, and entitled “Method for treating a liquid medium”, describes the use of ultrasound to disperse ozone in water and the use of ultrasound to aid in the cleanup of ozonated water. U.S. Pat. No. 5,207,993 issued to Burris, and entitled “Batch liquid purifier”, describes the use of ozone in water with recirculation of the water through the ozone injection region to purify water. U.S. Pat. No. 5,868,945 issued to Morrow, et al. and entitled “Process of treating produced water with ozone”, describes the use of ozone to treat water, containing hydrocarbons, at elevated temperatures. U.S. Pat. No. 6,006,387 issued to Cooper, et al. and entitled “Cold water ozone disinfection”, describes the use of ozone dissolved in water to disinfect mechanical assemblies. U.S. Pat. No. 6,115,862 issued to Cooper, et al. and entitled “Cold water ozone disinfection”, describes the use of ozone dissolved in water to disinfect mechanical assemblies. The disclosures of each of these references are herein incorporated by reference to the extent that they are not inconsistent with this application.
There also are disclosures relating to the use of oxidation, singly, to treat wastewater or water. For example, U.S. Pat. No. 3,992,295 issued to Box Jr., et al. and entitled “Polluted water purification”, describes a process of catalyzed oxidation. U.S. Pat. No. 4,141,829 issued to Thiel, et al. and entitled “Process for wet oxidation of organic substances”, describes a process of oxidation occurring at elevated temperatures. U.S. Pat. No. 4,604,215 issued to McCorquodale, and entitled “Wet oxidation”, describes a process of oxidation occurring at elevated temperatures. U.S. Pat. No. 4,699,720 issued to Harada, et al. and entitled “Process for treating waste water by wet oxidations”, describes a process of oxidation using catalysts. U.S. Pat. No. 4,793,919 issued to McCorquodale, and entitled “Wet oxidation system”, describes a process of oxidation occurring with mixing or stirring of the fluid. U.S. Pat. No. 5,053,142 issued to Sorensen, et al. and entitled “Method for treating polluted material”, describes a process of oxidation occurring in a fluid. U.S. Pat. No. 5,057,220 issued to Harada, et al. and entitled “Process for treating waste water”, describes a process of oxidation using catalysts. U.S. Pat. No. 5,145,587 issued to Ishii, et al. and entitled “Method for treatment of waste water”, describes a process of oxidation at elevated temperatures. U.S. Pat. No. 5,158,689 issued to Ishii, et al. and entitled “Method for purification of waste water”, describes a process of oxidation at elevated temperatures.
Additionally, U.S. Pat. No. 5,370,801 issued to Sorensen, et al. and entitled “Method for treating polluted material”, describes a process of oxidation occurring in a fluid. U.S. Pat. No. 5,614,087 issued to Le, and entitled “Wet oxidation system”, describes a process of oxidation occurring in a stirred or mixed fluid. U.S. Pat. No. 5,807,484 issued to Couture, et al. and entitled “Waste water treatment”, describes a process of oxidation using trickle filters. U.S. Pat. No. 5,888,389 issued to Griffith, et al. and entitled “Apparatus for oxidizing undigested wastewater sludges”, describes a process of supercritical oxidation occurring in a fluid at elevated temperatures and pressures.
No systems exist in the field of electrolytic removal of ammonia by direct electrolysis or by high pH chemical conversion at an electrolytic electrode. Needs exist for new systems of electrolytic removal of ammonia by direct electrolysis or by high pH chemical conversion at an electrolytic electrode.
SUMMARY OF THE INVENTION
A method is disclosed that directly removes ammonia (ammonium) from clarified wastewater. Further a system is disclosed that applies this method to treat and to remove specified levels of ammonia from wastewater and other process waters.
Human and animal waste can be treated by physical, chemical, or biological means such as: aerobic digestion, anaerobic digestion, advanced oxidation, chemical action, filtration, and solids separation. While major reductions in solids can be expected using these conventional processes, there is little reduction in nitrogen containing compounds, particularly ammonia.
A primary result of this invention is to directly remove ammonia in its aqueous form from wastewater or other process waters. Ammonia in water is typically in the form of ammonium ion —NH 4 . This is a form that is readily used by plants and is one major cause of algae and plant growth in the environment where wastewater is discharged.
This invention provides a simple and direct method to remove aqueous ammonia by electro-chemistry and electrolysis. Metallic electrodes are placed into the wastewater stream. A direct current voltage is applied to the plate electrodes; and current flows from the anode to the cathode. Electrolysis of the water occurs, generating oxygen at the anode and hydrogen at the cathode. This electrolysis has another important effect. The pH at the cathode is increased. We find that the pH at or near the cathode can exceed 9. At this pH aqueous ammonia is converted to ammonia gas. The addition of air at or below the cathode sparges the ammonia from the water and removes it from the system. The ionic polarity of the ammonium has an important secondary effect. Ammonium is directly attracted to the anode, and, in some conditions, electrolysis of the ammonium into ammonia occurs. Again, the addition of air at the anode sparges the ammonia, removing it from the system.
Approximately up to 98%, or more, of ammonia is removed from the overall wastewater stream using a system based on this inventive method.
The configuration described has a number of advantages. The ammonia is removed from the system with the application of electrical energy. There are no waste products. The ammonia that is removed from the wastewater can be recovered using standard refrigeration techniques and can result in a valuable byproduct fertilizer. Unlike biological solutions, our invention does not rely on living organisms for the success of the process. The process described herein is unlikely to be upset or interrupted by the presence of materials that are toxic to the organisms necessary for biological systems to operate.
It is therefore an object of the invention to describe a method and to provide a system and an apparatus for the treatment and/or removal of ammonia-containing compounds from wastewater or process waters that greatly reduces the level of ammonia reaching the environment.
These and further and other objects and features of the invention are apparent in the disclosure, which includes the above and ongoing written specification, with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of the method of the invention.
FIG. 2 is a schematic of one embodiment of the invention wherein the electrodes have a defined physical separation.
FIG. 3 is a schematic a second embodiment of the invention wherein closely spaced electrodes are mechanically separated by a thin porous membrane.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Two embodiments of a method of ammonia removal are disclosed herein. The embodiments differ in their potential electrical efficiency, but otherwise operate similarly. Those skilled in the art may recognize that other embodiments are possible but we decline to list all possible combinations herein.
The ammonia removal from the waste or process stream can reach approximately 90% to 98%, or higher, using the inventive system described below.
One embodiment of the system consists of one or more pairs of electrode plates arranged in a substantially planar fashion. The effectiveness of this or other embodiments is not impacted by the use of other geometries such as cylindrical geometries. The electrodes must be fabricated from corrosion resistant materials such as, but not limited to, titanium, platinum, or gold. Coatings may be placed on the titanium. These coatings may retard corrosion of the substrate and may aid in the efficiency of the electrolysis process. These coatings may consist of, but are not limited to, thin layers of such oxides as rhenium oxide, zirconium oxide, and rhodium oxide.
The embodiment uses, but is not limited to, electrodes whose width is 30 centimeters (cm) and whose length is 100 cm. This results in an electrode area of ˜3000 square centimeters (cm 2 ). Electrode dimensions can range from a few cm to hundreds of cm and are limited only by the physical constraints of the application and the engineering required to hold the electrode spacing to adequate tolerances. The electrodes are held in position using insulating spacers located at arbitrary points, but ideally near the edges of the plates where the flow of wastewater is not impeded. The sole purpose of the insulating spacers is to provide for the positive location of the electrodes, thus preventing the accidental shorting of the electrodes.
A voltage, typically, but not limited to, 4.5 V, is placed between the electrodes. The applied voltage can span the range of between 3.0 V and 50 V depending in the spacing of the electrodes and the conductivity (salinity) of the water. It is advantageous to keep the current density on the electrodes below 0.15 amperes (A) per cm 2 in order to maximize the electrode lifetime. In any case the successful operation of this embodiment is not significantly impacted by the absolute magnitude of the current on the electrodes.
In operation, electrical current flows uniformly through the water between the plates. This current heats the water and is a parasitic loss and has no beneficial action. It is therefore advantageous to operate with the electrode spacing as small as is mechanically possible. The spacing is typically limited by the flatness of the electrodes, particle content of the wastewater, and the operational safety margin desired for the system. The first embodiment uses, but is not limited to, a spacing of 3 millimeters (3 mm). Smaller electrode spacings permit lower operational voltages for the system. Voltage regulation provides no added performance to the system. During electrolytic cell operation, the pH of the water near the cathode increases to level>9. At or above a pH of 9, aqueous ammonium (NH 4 ) is converted to gaseous ammonia (NH 3 ).
Wastewater flows through the space between the plates. In this embodiment the water flows from the bottom of the electrodes to the top. Other water flow patterns are possible but upward flow assists in the removal of gaseous ammonia from the volume between the plates.
Fine bubbles of air are injected into the volume of water at the bottom of the electrode plates. The air flows upwards along and between the electrodes. This air carries with it gases generated at the electrodes including the ammonia released by the electro-chemical and electrolytic process. This gas can be released directly to the air if regulations permit or the ammonia in the gas stream can be captured using standard condensation techniques.
Under normal operation this embodiment at a voltage of 4.5 V will conduct a total current of ˜100 A per electrode pair. An embodiment consisting of multiple electrode pairs will draw a total current in multiples of the base 100 A per electrode pair. Someone skilled in the art will recognize that multiple electrodes can be electrically connected either in series or in parallel depending on the necessities of a particular installation. At an operational voltage of 4.5 V the embodiment as described will consume a peak electrical power of 450 watts (W) per electrode pair.
A second embodiment of the system consists of one or more pairs of porous electrodes arranged in a substantially planar fashion. The effectiveness of this or other embodiments is not impacted by the use of other geometries such as cylindrical geometries. The porosity of the electrodes is needed in order to maintain a flow of wastewater through the cell. The electrodes are fabricated from corrosion resistant materials such as but not limited to titanium. Other coatings may be placed on the titanium. These coatings may consist of, but are not limited to, thin layers of such oxides as rhenium oxide, zirconium oxide, and rhodium oxide.
The embodiment uses, but is not limited to, electrodes whose width is 30 cm and whose length is 100 cm. This results in an electrode area of ˜3000 cm 2 . Electrode dimensions can range from a few cm to hundreds of cm and are limited only by the physical constraints of the application and the engineering required to hold the electrode spacing to adequate tolerances.
The electrodes are positioned closely together using an insulating membrane with a thickness of 1 mm. The membrane materials are such as but not limited to Nafion 450™ to separate the anode from the cathode. The anode is typically on the effluent side and is used to protect the membrane from fouling with organics. The sole purpose of the thin membrane is to provide for the smallest possible spacing of the electrodes, thus minimizing the operational voltage and, hence, power. A voltage, typically, but not limited to, 1.5 V, is placed between the electrodes. The applied voltage can span the range of between 1.0 V and 50 V depending in the thickness of the membrane and the conductivity (salinity) of the water.
In operation current flows through the water saturated membrane between the plates. This current heats the water and is a parasitic loss and has no beneficial action. It is therefore advantageous to operate with thinnest membrane possible. The spacing is typically limited by the uniformity of the membrane and the operational safety margin desired for the system. The second embodiment uses, but is not limited to, a membrane thickness of 1 mm. During electrolytic cell operation, the pH of the water near the cathode increases to level>pH 9. At or above a pH of 9, aqueous ammonium (NH 4 ) is converted to gaseous ammonia (NH 3 ).
Wastewater flows through the electrodes and the membrane. In this embodiment the water flows from the bottom of the electrodes to the top. But the flow is arranged to move through the anode, the membrane, and out the cathode. Other water flow patterns are possible but flow through the anode refreshes the water in the membrane and the upward flow assists in the removal of gaseous ammonia from the volume between the plates.
Fine bubbles of air are injected into the volume of water at the bottom of the cathode. The air flows upwards along and between the cathodes. This air carries with it gases generated at the electrodes including the ammonia released by the electro-chemical and electrolytic process. This gas can be released directly to the air if regulations permit or the ammonia in the gas stream can be captured using standard condensation techniques.
Under normal operation at a voltage of 1.5 V the second embodiment will conduct a total current of ˜100 A per electrode pair. An embodiment consisting of multiple electrode pairs will draw a total current in multiples of 100-A per electrode pair. Someone skilled in the art will quickly recognize that the electrodes can be electrically connected either in series or in parallel depending on the necessities of a particular installation. At an operational voltage of 1.5 V the embodiment as described will consume a peak electrical power of 150 W per electrode pair. Note the power consumption of the second embodiment is 33% of that used by the first embodiment.
All embodiments of this invention suffer from the accumulation of mineral deposits on the cathode. The most common of these deposits is calcium carbonate. Calcium and other metal anions move to the cathode where the high pH of the water takes the carbonates from solution. If left unchecked this would eventually completely cover the electrode and prevent the successful operation of the system. Three methods for preventing the build up of carbonates are possible. First, reversing the polarity of the plates on a regular basis removes the built up deposits. If the cathode becomes the anode the acidic environment will dissolve the carbonate buildup. Second, the application of a moderate level of ultrasonic acoustic energy prevents the build up of mineral deposits. Third, frequent abrasion of the surface with a mechanical scrubber prevents the excessive buildup of minerals. In the case of the membrane used in embodiment two, an occasional detergent wash may be necessary to remove greases and oils that may accumulate in the membrane. The oxygen generated from the anode side assists membrane cleanliness.
The preferred method to keep the surface clean is an engineering decision based on the many tradeoffs that must be made for any particular implementation. In principle, the formation of mineral deposits can be totally eliminated by having a waste stream consisting of softened water. For large volumes of water this is impractical.
Reference is made to FIGS. 1-3 . FIG. 1 is a flow diagram of the method of the invention. The cell electrodes, electrical systems, wastewater flow, an air/ammonia components found in the invention are described. The ammoniated waste water inputs at the bottom of the electrodes and exits at the top. Air containing ammonia is vented at the top of the system. FIG. 2 provides a detailed schematic view of the components and arrangement of the first embodiment. A schematic of a second embodiment using porous membranes is seen in FIG. 3 .
FIG. 1 shows the block diagram of the method for ammonia removal. Wastewater 1 flows into the lower portion of the treatment tank 2 . An assembly of planar electrodes 3 is suspended in the treatment tank 2 . Voltage is applied to the electrode with a direct current power supply 4 . Air 5 is supplied with a low pressure bubbling system 6 (e.g. venturi air injection). Ammonia gas 7 is released below the electrode assembly 3 . The injected air 5 sparges the released ammonia 7 and the resulting gas mixture 8 is exhausted from the treatment tank 2 . The treated wastewater 9 leaves the treatment tank 2 near the top of the tank.
FIG. 2 shows a detailed schematic of the first embodiment. Wastewater 11 flows into a canister filter 12 (or equivalent) to ensure that the water has no significant particle content. The filtered wastewater 13 flows in the treatment unit 14 . The treatment unit 14 contains an electrical series configuration of electrolysis electrodes 16 . The treatment unit 14 consists of a sandwich of hollow insulating plastic plates 15 and electrolysis electrodes 16 . The insulating plates can be composed of any suitable plastic such as but not limited to acrylic, polycarbonate, Teflon, or PVC. The insulating plastic plates 15 serve to precisely space the electrodes 16 and electrically isolate them. Water is fed into a series of distribution holes 17 located at the bottom of each cell (between the electrodes 16 ). The number, size, and length of the holes are determined by the need to minimize the leakage electrical current flowing around the plates. In the water distribution manifold sparging air 18 is injected. This sparging air 18 rises between the electrodes. A direct current power supply 19 applies voltage to the electrodes 16 at the first electrode plate 20 and the last electrode plate 21 . The applied voltage per cell is the total applied voltage divided by the number of electrolysis cells 15 in the treatment unit 14 . Ammonia gas 22 is formed on the electrodes 16 . The sparging air 18 to the exhaust 24 carries gaseous ammonia 22 away. The resultant gas mixture flows from the treatment unit 14 where it is exhausted or potentially recovered. An ultrasonic transducer 23 applies sonic energy to the electrolysis cells 15 to prevent the build up of carbonate on the electrodes 16 . The treated wastewater 25 exits the treatment unit 14 .
FIG. 3 shows a close up detailed schematic of the second embodiment. The schematic for FIG. 3 is similar to that of FIG. 2 except that the space between electrodes of opposite polarity is filled with a porous membrane and the spacing is reduced. Wastewater 30 flows into a canister filter 31 (or equivalent) to ensure that the water has no significant particle content. The filtered wastewater 32 flows in the treatment unit 33 . The treatment unit 33 contains an electrical series configuration of electrolysis electrodes 34 consisting of a sandwich of hollow insulating plastic positioning plates 35 and hollow porous electrolysis electrodes 34 . The insulating plates can be composed of any suitable plastic such as but not limited to acrylic, polycarbonate, Teflon, or PVC. The insulating plastic plates 35 serve to precisely position the electrodes 34 together, to clamp the electrodes onto the 1-mm thick membrane 36 , and electrically isolate the electrodes 34 . Water is fed through holes 42 in the bottom plastic positioning plates 35 into one set of electrodes and is exhausted at the top of adjacent porous electrodes of opposite polarity. Sparging air 37 is injected into the hollow electrodes 34 as needed. A direct current power supply 38 applies voltage to the electrodes 34 at the first electrode plate 39 and the last electrode plate 40 . The applied voltage per electrode pair (a cell) is the total applied voltage divided by the total number of electrolysis cells. Ammonia gas 41 is formed on the surface of the electrodes 34 . Gaseous ammonia 41 migrates into the hollow electrodes and is carried away by the sparging air 37 and water. The treated wastewater 43 , having passed through the electrolysis system, exits the treatment unit 33 .
While the invention has been described with reference to specific embodiments, modifications and variations of the invention may be constructed without departing from the scope of the invention. | A method and system are described to treat ammonia-containing wastewater or process waters. Sewage containing human or animal waste and certain process liquids, typically water, contains high levels of nitrogen in the form of ammonia. An electro-chemical method to extract the ammonia from the wastewater is also described. The system described is one implementation of this method. One or more electrolysis cells convert ammonium to ammonia where the generated ammonia gas can readily be extracted for disposal or reuse. Such a system can involve electrolysis cells of numerous types as described herein. | 2 |
TECHNICAL FIELD
[0001] Embodiments of the invention relate generally to systems and methods for reimbursing insured individuals for losses, and, more particularly, to systems, methods, and financial-services products that may be used to facilitate the purchase of approved replacement items or to spend funds according to spending categorization or time-based rules.
BACKGROUND OF THE INVENTION
[0002] Consumers and businesses often purchase insurance to cover losses to property ranging from personal items to buildings and infrastructure. Coverage can vary widely. Home insurance, for example, may cover more than just a physical structure. A typical homeowner's policy usually covers the loss of items within the home, such as furniture, clothing, electronics, appliances, artwork, jewelry, and other items. Renter's insurance covers many of the same items, excluding fixtures and the like. Insurance may also, in some cases, cover additional living expenses, such as temporary housing, food and restaurant expenses, dry cleaning, transportation, etc.
[0003] When a loss occurs, conventional practice is for the insurance company (the “issuer”) to assess the damage, estimate the loss, and provide a “live” check to the insured. In some instances, the policy also covers recurring incidental expenses, such as hotel bills, food, transportation, and the like. While the issuer of the policy may control the amount of the check, it cannot determine how the insured will actually use the money, either initially or over time. Moreover, issuing live checks is expensive, and vulnerable to loss and fraud.
[0004] The Commercial and financial industries have, over the past few years, actively embraced the “stored-value card” or “debit card” concept. These cards provide the holder with a pre-defined spending limit based on either a bank-account balance or a set amount associated with the card. The cardholder may use the card at participating establishments to purchase goods and services until the funds associated with the card are exhausted. Like credit cards, debit cards and some stored-value cards require authorization or activation by in individual cardholder prior to an initial use, and, in some cases, the use of a personal identification number (“PIN”) to make purchases with the card.
[0005] While less expensive and more secure than live checks, stored-value cards can still be used freely—i.e., with no restriction on what is purchased, regardless of the nature of the loss. This limits the ability of the issuer to tailor a spending program to a particular loss, and to exhibit flexibility in terms of what is purchased. Particularly in cases where the issuer provides ongoing funding for living expenses (e.g., as the insured's house is being repaired), the issuer may wish to provide the insured with a periodic (typically weekly) budget and restrict expenditures to legitimate items. In addition, the issuer may wish to accord budgetary flexibility on some items (allowing the insured to “borrow” from the next period's budget for essentials such as food, for example) but not on others.
[0006] What is needed is a system and associated techniques and products that allow for item-level monitoring and flexibility, particularly in connection with time-based or recurring expenses.
BRIEF SUMMARY OF THE INVENTION
[0007] Embodiments of the present invention permit insurance companies to issue stored-value cards (or other means to access a financial account) governed by a set of rules that limit purchases to approved replacement items and/or recurring living expenses based on losses actually incurred by the insured within certain categories and according to time-based, insurer-specified spending limits. In various embodiments, these limits can be altered by the insurer in response to changed circumstances or the needs (or behavior) of the insured.
[0008] In one aspect of the invention, a system that operates in conjunction with a financial account is provided for permitting usage of the funds associated with the financial account to purchase goods and/or services. The system includes an event-detection module for detecting a purchase event initiated by an individual associated with the financial account. A rules engine applies a rule set against the purchase event to determine if the potential purchase complies with the rule set. The rule set includes both a category-based rule and a time-based rule, such that a maximum amount may be spent on purchases during a particular time period (e.g., a month) within a particular category (e.g., food, housing, transportation, medical care, etc.). The system further includes a messaging module for approving the purchase if it complies with the rule set.
[0009] In some instances, the financial account is established in response to an insurance claim. The financial account may represent an amount of money available to the owner or owners of the insurance policy on which the claim was filed. In some cases, the rule set associated with the financial account limits purchases during the specified time period to amounts below a predefined limit for the category. However, in some embodiments, an exception may be made wherein a purchase above the limit is allowed (up to an alternative limit, for example), but the amount over the allowed amount is deducted from an amount allowed for a subsequent time period or from a general settlement amount issued to cover contents and/or structural damage. The system may also include a data-storage component for storing rule sets associated with financial accounts. In some cases, the rule set may also limit what can be purchased (e.g., limiting purchases to particular items) and/or where they may be purchased. For example, the rules may specify that the individual(s) associated with the financial accounts may only purchase specified items from particular businesses.
[0010] In another aspect of the invention, a device associated with a financial account is provided. The device may include a data-storage medium for storing computer-readable program code governing the authorization and use of the device. In some instances, the device is a stored-value card, a debit card or a credit card. In other cases, the device is a virtual device, such as an on-line credit, gift certificate, or balance made available to its users. The program code may include instructions for implementing rules governing use of the device, such as restrictions on goods or services to which the money in the account may be applied, how much may be spent during a particular time period within a particular category of goods and services, who may spend it, a date by which the money must be spent, and/or establishments where the money is spent.
[0011] In yet another aspect, a computer-implemented method is provided for authorizing and governing the use of funds associated with a financial account. The computer-implemented method comprises receiving a purchase event identifying a purchase by an individual associated with the financial account, and a rule set is applied against the purchase event to determine if the purchase complies with the rule set. The rule set includes both a category-based component and a time-based component, such that a maximum amount may be spent on purchases during a particular time period (e.g., a month) within a particular category (e.g., food, housing, transportation, medical care, etc.). The purchase is approved if it complies with both the time and category-based rules.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The present invention is described in detail below with reference to the attached drawing, wherein:
[0013] FIG. 1 is a flow chart illustrating the operation of a system in accordance with various embodiments of the invention; and
[0014] FIG. 2 is a block diagram illustrating the components of a system in accordance with various embodiments of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0015] When a consumer or business suffers a loss of property due to fire, theft or other event, an insurance claim may be filed to cover the replacement cost associated with the loss. Often, the claim arises from an insurance policy owned either by an entity (e.g., a corporation) or a couple (e.g., a husband and wife). In either case, common practice is to issue a live check in the amount deemed appropriate given the loss. For example, if a fire consumes clothing, appliances and household items in a couple's home, the couple can file a claim against their homeowner's policy requesting reimbursement for the lost items. Once an amount is agreed upon, the insurer issues a check.
[0016] In some instances, proceeds from an insurance claim may be used to for recurring living expenses such as groceries, housing (e.g., a hotel), transportation, medical expenses, and other daily expenditures. However, the insurance companies may want to put in place rules that govern how the proceeds (or relevant portion thereof) can be spent during any one time period or on certain items. For example, the insurer may have negotiated special rates with a hotel chain, allotting $5,000 per month for a hotel based on these rates and $1,500 per month for restaurant and grocery expenses. With such constraints in place, the insurer can ensure that the insured party uses the proceeds from their claim appropriately.
[0017] FIG. 1 illustrates the operation of a representative embodiment of the present invention, in which the holder of a stored-value card purchases items using funds in a financial account associated with the card. As used herein a “card” may refer to a debit card, a credit card, a gift card, an online stored-value account, or other device (either physical or virtual) that is associated with the financial account. In order to help the cardholder budget her purchases and use the funds to cover basic living expenses, some (or all) of the funds may be subject to certain usage rules. The rules may, for example, determine how much can be spent during a particular time period (e.g., monthly) and/or for a particular category of good or service. In such cases, the card may be identified as a “temporary living expense card” and its use may be limited to such purchases. In other instances, a general settlement account may be set up with a pool of funds that are available generally, and may be used to augment funds allocated to a particular category, if so approved. In other cases, the rules may dictate that, even if funds are available in a general settlement account, limits on certain living expenses (e.g., food, clothing, housing) may be capped.
[0018] As shown in FIG. 1 , an insurance claim is filed and a financial account is established on behalf of the claimant(s). The insurer defines a rule set for the account ( 102 ) that governs allowable purchases using the account. In some cases, funds are allocated to a particular category ( 104 ). For example, if the account is initially funded with $75,000 to cover a year of living expenses, $60,000 may be allocated to “shelter” (e.g., for hotel bills) and $15,000 for food. Other categories such as transportation (to pay for a rental car, for example), medical expenses, and clothing may be set up. Further, these funds may be allocated over a series of time periods ( 106 ) to assist the insured parties with budgeting. Using the example above, the $60,000 allocated to shelter may be divided into twelve monthly tranches of $5,000 each. As a result, requests for payment authorization for purchases that, in total, exceed $5,000 in any one month may be denied or, in some cases, subject to an additional approval process.
[0019] Once set up, the insured party is given access to the financial account and uses the card to purchase goods and services ( 108 ). Information describing the purchase (type of goods being purchased, amount, date, establishment at which goods are being purchased or lodging obtained, category of goods or services, etc.) is analyzed and a decision ( 110 ) is made as to whether to approve the purchase or not. If, for example, the proposed purchase is a hotel bill for $3,000 but only $2,500 remains in the account, the purchase may be declined ( 112 ). If the purchase is approved but attributed to a category having specific spending limits, a second rule check is performed ( 114 ) to determine if the particular purchase is governed by the rules. Using the example above, the $5,000 monthly stipend may be applied against a series of charges to hotels, and the purchases denied if they exceed $5,000 for a particular month. If the purchase does not fall within a limited category, the purchase is authorized ( 115 ). If the purchases falls within a limited category, a check is made to determine of the purchase is within the specified limits ( 116 ). If it is within the limit, the purchase is authorized ( 15 ).
[0020] In some instances, spending in excess of the funds remaining on the card (or usable during the current spending period) may be allowed. For example, the base rule may limit monthly spend on food to $1,000, but allow a “buffer” or excess spend of $200 per month. The excess may be quantified as an absolute amount or as a percentage of the overall monthly budget (i.e., 10%). In such cases, a determination whether to allow the excess spend is made ( 117 ). If so, the purchase is authorized ( 115 ), the funds are debited from the account (either a general account, another category, or the same category but from a future time period) and allocated to the appropriate category ( 118 ). If the category has no limits, the funds are debits from the account without any category allocation.
[0021] In some cases, the excess amount may be deducted from a subsequent period's allocated funds. For example, an approved excess spend of $200 in one month may be “deducted” from the budgeted amount for the following month, leaving, in the example above, $800 budgeted for food. In some cases, the excess spend may be spread across some or all of the remaining time periods (e.g., $40/month for five months) to lessen the impact on any one month. In other examples, the allocation of funds may be unequal across time periods to allow for seasonal adjustments (e.g., holidays, summer vacations, etc.). One or more spending reports ( 120 ) may be generated and provided to the cardholder and/or the financial institution managing the account.
[0022] In some cases, the spending reports may be used as feedback ( 122 ) to update the rule set. For example, if the cardholder routinely spends more money in a particular category than originally allocated to that category, the rule set may be updated such that the spending limit for that category may be increased. Likewise, if a cardholder rarely uses the funds (e.g., funds allocated to a hotel are not used because she is staying with a relative) the funds can be reallocated to other categories.
[0023] FIG. 2 illustrates a system for implementing the techniques described above. A card or cards 200 may have stored thereon computer-readable instructions and/or data governing usage restrictions, by means, e.g., of a magnetic strip 222 , an embedded chip or memory device 244 , or both. More typically, however, the card 200 may include only identifying information, with purchases approved and the rules enforced from a central location, as described below. The card 200 may also include components for providing or processing either account, identity, payment, health, transactional, or other information and communicating with central processing units or computers operated by the providers of services, such as credit card institutions, banks, health care providers, universities, retailers, wholesalers or other providers of goods or services employers, or membership organizations. Card features may also enable the card to communicate with or be accessed by other devices, including those used by retailers (e.g., point-of-sale computers), and personal computers used in other business applications or at home (for example, a personal computer having a built-in or attached card reader).
[0024] A central computing device 206 processes purchase transactions related to the use of the card 20 , and includes an event-detection module 208 , a rules engine 210 , a messaging module 212 , and in some instances one or more data-storage devices 214 (e.g., hard disks). The data-storage devices 214 and/or central computing device 206 may store financial information pertaining to the account related to the card 200 as well as instructions for activating and authorizing use of the card. The central computer device 206 may send and receive communications regarding card usage over a network 216 , such as the Internet or, in some cases, a private network. Cardholders may use one or more computing and/or communication devices (e.g., a computer 218 or a hand-held device 220 ) to send and receive account information and authorization messages from the central computing device 206 .
[0025] For example, the central computing device 206 receives messages and/or events from cardholders wishing to use the card 200 to purchase goods and services. However, in some implementations, the card 200 may be associated with a financial account having one or more usage restrictions, and in such cases the event-detection module 28 identifies an potential purchase request from a cardholder and the rules engine processes computing instructions that apply the rule set against the purchase request to determine if is an authorized purchase.
[0026] The rule set—which may be organized in a database containing rule sets for multiple cardholders, as described below—may include category and time-based restrictions as described above, and/or may also implement guidelines or incentives (e.g., using the card at a particular retailer allows the cardholder to receive special discounts and other offers). In other cases the rules may dictate that the cardholders use the cards at specific locations (either physical or web-based) and/or for specific items. This may be the case where, for example, the card is issued based on an insurance claim against particular property such as electronics and clothing lost in a house fire. In such instances, the card issuer or the insurance company may operate a retail portal that allows cardholders to shop for replacement items directly, or in some cases via referrals to other participating retailers.
[0027] Further, the insurance company may attribute usage rules to the card (and, by extension, the funds in the account associated with the card) that limit what the cardholders can purchase, where they can make specific types of purchases, price restrictions on certain goods, and/or a deadline (e.g., the end of the current recurring time period) by which certain (or all) purchases must be made. These rules are stored in the data-storage device 214 and implemented by the rules engine 210 each time the card 200 is used—i.e., each time event-detection module 208 detects an attempt to make a purchase. For example, with a master set of rules stored in a database, rules engine 210 implements only those rules applicable to a particular cardholder. Each cardholder's database record may contain pointers to the rules associated with that cardholder, along with arguments or values (particular types of items, allowed retailers, spending limits, etc.) for the parameters called for in the rules. These may be modified centrally as appropriate, and the specified rules in their current form, with the current parameter values, are invoked for each cardholder whenever he uses the card.
[0028] For example, a couple who recently suffered a loss due to a fire in their home may need to purchase new furniture, new clothing, new appliances, new electronics, and other household goods to replace those lost or damaged in the fire, as well as monthly living expenses such as hotel bills, groceries, etc. Using the technique and system described above, the card is associated with a financial account funded by their insurance company. The insurance company may instruct the card issuer that only a certain amount may be charged on the card per month related to food purchases. Alternatively, the card issuer may transmit purchase information (cardholder identity and item to be purchased, for example) to a third party server, and allow the purchase to go through only upon receipt of approval once received from the insurance company.
[0029] In some implementations, the merchandise available to the cardholder may be pre-specified by the insurer funding the financial account to which the card is related. Such a restriction may be used to ensure that the cardholders use the funds from their claim to purchase actual replacement items, and, in some cases, may facilitate the collection of referral fees from the retailers in exchange for channeling customers to their establishment. In certain instances, the merchandise available to a particular cardholder may be limited only to the exact items (or approved alternatives) claimed as lost pursuant to their policy. All of these restrictions may be implemented in rules, as described above.
[0030] In some cases, a third-party may work with one or more online retailers (e.g., Amazon.com) and/or brick-and-mortar retailers with an extensive online presence (e.g., Sears, Target, etc.) to build cardholder-specific portals at which on the approved merchandise is available and, in some cases, use of the activated cards may be limited—by user-specific rules—to purchases from these portals. In other cases, the cards may be authorized for use at any retail establishment without any restrictions whatsoever. The third parties may contract with specific insurers, card issuers or both to provide these services.
[0031] The components of the central computing device 26 may be implemented by computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc. that performs particular tasks or implement particular abstract data types. Those skilled in the art will appreciate that the invention may be practiced with various computer system configurations, including hand-held wireless devices such as mobile phones or PDAs, multiprocessor systems, microprocessor-based or programmable consumer electronics, minicomputers, mainframe computers, and the like. The invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices.
[0032] The central computing device 206 may include a general-purpose computing device in the form of a computer including a processing unit, a system memory, and a system bus that couples various system components including the system memory to the processing unit. Computers typically include a variety of computer-readable media that can form part of the system memory and be read by the processing unit. By way of example, and not limitation, computer readable media may comprise computer storage media and communication media. The system memory may include computer storage media in the form of volatile and/or nonvolatile memory such as read only memory (ROM) and random access memory (RAM). A basic input/output system (BIOS), containing the basic routines that help to transfer information between elements, such as during start-up, is typically stored in ROM. RAM typically contains data and/or program modules that are immediately accessible to and/or presently being operated on by processing unit. The data or program modules may include an operating system, application programs, other program modules, and program data. The operating system may be or include a variety of operating systems such as Microsoft WINDOWS operating system, the Unix operating system, the Linux operating system, the Xenix operating system, the IBM AIX operating system, the Hewlett Packard UX operating system, the Novell NETWARE operating system, the Sun Microsystems SOLARIS operating system, the OS/2 operating system, the BeOS operating system, the MACINTOSH operating system, the APACHE operating system, an OPENSTEP operating system or another operating system of platform.
[0033] Any suitable programming language may be used in accordance with the various embodiments of the invention. Illustratively, the programming language used may include assembly language, Ada, APL, Basic, C, C++, C*, COBOL, dBase, Forth, FORTRAN, Java, Modula-2, Pascal, Prolog, Python, REXX, and/or JavaScript for example. Further, it is not necessary that a single type of instruction or programming language be utilized in conjunction with the operation of the system and method of the invention. Rather, any number of different programming languages may be utilized as is necessary or desirable.
[0034] The computing environment may also include other removable/nonremovable, volatile/nonvolatile computer storage media. For example, a hard disk drive may read or write to nonremovable, nonvolatile magnetic media. A magnetic disk drive may read from or writes to a removable, nonvolatile magnetic disk, and an optical disk drive may read from or write to a removable, nonvolatile optical disk such as a CD-ROM or other optical media. Other removable/nonremovable, volatile/nonvolatile computer storage media that can be used in the exemplary operating environment include, but are not limited to, magnetic tape cassettes, flash memory cards, digital versatile disks, digital video tape, solid state RAM, solid state ROM, and the like. The storage media are typically connected to the system bus through a removable or non-removable memory interface.
[0035] The processing unit 206 that executes commands and instructions may be a general purpose computer, but may utilize any of a wide variety of other technologies including a special purpose computer, a microcomputer, mini-computer, mainframe computer, programmed micro-processor, micro-controller, peripheral integrated circuit element, a CSIC (Customer Specific Integrated Circuit), ASIC (Application Specific Integrated Circuit), a logic circuit, a digital signal processor, a programmable logic device such as an FPGA (Field Programmable Gate Array), PLD (Programmable Logic Device), PLA (Programmable Logic Array), RFID processor, smart chip, or any other device or arrangement of devices that is capable of implementing the steps of the processes of the invention.
[0036] The network 216 may include a wired or wireless local area network (LAN) and a wide area network (WAN), wireless personal area network (PAN) and/or other types of networks. When used in a LAN networking environment, computers may be connected to the LAN through a network interface or adapter. When used in a WAN networking environment, computers typically include a modem or other communication mechanism. Modems may be internal or external, and may be connected to the system bus via the user-input interface, or other appropriate mechanism. Computers may be connected over the Internet, an Intranet, Extranet, Ethernet, or any other system that provides communications. Some suitable communications protocols may include TCP/IP, UDP, or OSI for example. For wireless communications, communications protocols may include Bluetooth, Zigbee, IrDa or other suitable protocol. Furthermore, components of the system may communicate through a combination of wired or wireless paths.
[0037] While particular embodiments of the invention have been illustrated and described in detail herein, it should be understood that various changes and modifications might be made to the invention without departing from the scope and intent of the invention. From the foregoing it will be seen that this invention is one well adapted to attain all the ends and objects set forth above, together with other advantages, which are obvious and inherent to the system and method. It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated and within the scope of the appended claims. | Stored-value cards are governed by a set of rules that limit purchases to approved replacement items and/or recurring living expenses based on losses actually incurred by the insured within certain categories and according to time-based, insurer-specified spending limits. These limits can be altered in response to changed circumstances or the needs (or behavior) of the insured. A system for implementing various aspects of this technique includes an event-detection module for detecting a purchase event initiated by an individual associated with the financial account. A rules engine applies a rule set against the purchase event to determine if the potential purchase complies with the rule set. The rule set includes both a category-based rule and a time-based rule, such that a maximum amount may be spent on purchases during a particular time period (e.g., a month) within a particular category (e.g., food, housing, transportation, medical care, etc.). The system further includes a messaging module for approving the purchase if it complies with the rule set. | 6 |
This invention relates to an improved apparatus and method for secure entry systems, characterized by using a rotating electronic security code or equivalent technology with an automatic self-learning receiver. The invention is especially useful in multi-user applications, where many persons can individually operate or activate a single gate or door, for example. It can also be beneficial for smaller numbers of users, although single users or individual homeowners might find it easier and slightly more secure to use conventional systems (such as those described herein) that require manual “learning”.
BACKGROUND OF THE INVENTION
A wide range of “keyless” security systems exist, including remote controlled gate operators and the like for residential, industrial, and/or business installations. Depending on the installation and circumstances, a large number of users may need to pass through a given entry on a regular basis. Similarly, in certain circumstances, there may be a substantial turnover or addition to the number or identity of users needing access (or having authorized access) during any given period of time. For example, employment changes, expansion, and similar factors can affect the number and identity of persons needing access through a particular company's entry gate, door, barrier arm, turnstile, or any other access control point.
In many applications, such systems include multiple transmitters (one is given to each authorized user), each of which activates a single receiver. Transmitters can take many forms, including (without limitation) cards, handheld electronic keys, RF or other frequency button activated devices, etc. The receiver is typically located at or near the controlled gate or door and, upon receiving an appropriate signal from any such transmitter, the receiver activates (typically opens or unlocks) the gate or door.
Security of such entries is improved by providing user-specific remote controls a unique, identifiable transmitter/controller for each user. That improved security normally comes at some cost, in that such user-specific controls can be burdensome to program, use, and administer, if they are available at all.
Such systems vary widely in their complexity and consequent degree of security. For example, transmitters commonly range from 256 code combinations (using eight DIP switches) to 65,536 code combinations (using 16 bit keys).
Criminals or other persons have attacked security system technologies with technologies of their own. Among other things, these counter-efforts include code breakers such as code scanners (signal-generating devices that can generate a massive series of signals, one of which may be the “correct” signal that activates the security system's receiver), and code grabbers (which can surreptitiously record a signal as it is generated by an authorized user, and can subsequently re-emit that identical signal). Such counter-efforts can seriously compromise the security of certain systems.
Later generation security systems attempted to address those counter-technologies. One such effort was to utilize 32-bit keys to increase the number of code combinations. However, this increase in bit keys only added to the number to combinations that a code scanner had to try before the right combination was “cracked.” Against a code grabber, this increase provided no additional protection.
Rotating code or code hopping security systems address the problem by utilizing code generators to produce different signals each time a transmitter emits a signal. With the addition of encryption and a 64-bit transmission length, such systems have substantially improved security. “Unique” identifying information is typically “burned” into each transmitter's internal chips or circuitry, and that information can be used within the security system not only to control which transmitters are “authorized” to open a gate (by way of example), but even to track and log which transmitters were in fact used at which time(s). Examples of such improved technology are discussed in U.S. Pat. Nos. 5,517,187 and 5,686,904. Commonly, that “unique” information is part of the signal that is transmitted to the receiver in order to activate the gate, door, etc.
Typically, for these systems to be-effective, the system administrator has to control and track the distribution of the transmitters, but that commonly involves only two actions: an initial “check-out” (when the transmitter is given to the user/tenant) and subsequent “check-in” (such as when the tenant turns in his or her keys/controllers/etc. upon terminating their lease). In the event of some intervening problem, however, such control and tracking of users and their respective transmitters can enable the manager/owner to “disable” the transmitter (even though it has not been returned to the manager/owner) by removing its “identification” from the list of authorized users within the receiver. This “authorized list” is a control level that is independent of the “learning” process required for each transmitter. Even if a transmitter is “learned” into the receiver, this further control can override and prevent activation of the gate or door based on that “unique” identification information in the transmitter.
Newer 64-bit technology has now raised the number of unique code combinations into the billions, and is further secured when combined with the aforementioned rotating code and encryption technologies. Against such systems, contemporary code scanners and code grabbers are ineffective, and at least currently, this type of security system is extremely difficult (or even virtually impossible) to “crack”. Foreseeably, further advances in computer technology and manufacture will increase those combinations even further and may add additional “security” aspects to the technology.
Despite their advantages, conventional rotating code or code hopping security systems have some shortcomings. Among other things, they can be difficult or burdensome to administer when there are multiple users and/or there is turnover among the users. This difficulty arises at least in part from the fact that each transmitter (with its “unique” identifying code or other unique information) typically must be “learned” into the receiver (see, e.g., U.S. Pat. No. 5,686,904) before the transmitter is operational. In this “learn” process, a button or several buttons on the receiver are manually pushed, which switches the receiver from normal operation to “learn” mode. While the receiver is in that “learn” mode, the transmitter that is to be “learned” is then aimed towards the receiver and its transmit button pushed. The transmitter emits and the receiver receives a 64-bit or other signal which contains various sub-signals or information (such as a synchronization signal, a button signal, facility code signal, etc.). Once that transmitter's signal is received, compared, and processed, the transmitter is “activated” and available for future use (in effect, the receiver side of the system will thereafter recognize that unique transmitter and its signals as “authorized”). This “learning” process must be repeated for each other transmitter before those other transmitters will activate the receiver.
Consequently, and as indicated above, despite the benefits of this rotating code or code hopping technology, it can be cumbersome to administer in a large user situation. For example, if such a system is used in an apartment or business complex, each tenant's transmitter must be “manually” learned or programmed before the tenant can use it. Such transmitters are used, for example, to open a common gate that permits entry into an apartment complex parking or common areas. Under this scenario, either each tenant must be taught how to program or “learn” his transmitter into the receiver, or the management/owner of the complex must do so for each tenant/transmitter. If there is a power failure, the “learning” can be lost from the receiver (unless flash memory, emergency backup power sources, permanent memory, or similar technology is provided), which requires that all transmitters to be relearned. Even if permanent memory is used, however, other failure of the receiver or access control system can require that all the transmitters be relearned into the replacement equipment. During any such period of inoperability (not only during the power outage itself, but during any period of time required to “relearn” the transmitters), access to the complex can either be precluded (even for tenants that are authorized to enter) or uncontrolled (such as if the gate is left open to prevent a massive number of frustrated tenants from not being able to enter the complex).
Other problems can occur in such multi-user systems, such as when one tenant or user tries to enter through the gate while another transmitter is being “learned”. Also, if the apartment manager or owner programs in or “learns” all the transmitters himself, he could be programming hundreds or even thousands of transmitters, a very daunting task.
OBJECTS AND ADVANTAGES OF THE INVENTION
It is, therefore, an object of the present invention to provide an improved security system that provides the heightened security of technology such as rotating code or code hopping, without the administrative burdens currently associated with that technology. The invention is especially useful for installations involving a large user population, although single or small user populations can benefit from the invention as well.
Another object of the invention is the provision of a system of the aforementioned character that has the ability to automatically or remotely “learn” some or most transmitters, such as at least being able to “automatically” learn all transmitters after the first transmitter is “manually” learned.
A further object of the invention is the provision of a security system method and apparatus of the aforementioned character, that automatically learns in new transmitters without the users necessarily realizing that their transmitters are being “learned”.
Some of the objects of the invention incorporate aspects of existing technology, such as requiring multiple signal transmissions from any given transmitter before the transmitter is “learned” (this is known within “manually” learned systems). Similarly, although alternative embodiments of the invention could be modified using existing “manual learning” technology to learn via a single transmission (or by more than two transmissions), the preferred embodiment of the invention requires two signals from any given transmitter, thereby taking advantage of the rotating code or code hopping technology. Under anticipated usage, this double press would be relatively transparent to a user, so that the user would not necessarily even realize that he or she was in the “learn” mode.
Yet another object of the invention is providing a security method and system having the ability to manually preprogram (or “teach” or learn into) a receiver the codes or similar information to identify and function with one or more transmitters, so that all transmitters that correspond to such preprogrammed information (including even the first transmitter used) will be automatically “learned” into the receiver upon pressing the transmitter button, thereby avoiding the need to manually learn even the first such transmitter.
A still further object of the present invention is the providing a security system improvement that is compatible with, and has the ability to operate within, a multitude of prior art access control systems (including, by way of example and not by way of limitation, Weigand controllers, computers, and telephone systems).
An additional object of the present invention is the provision of a security system of the aforementioned character, in which the automatic learning of transmitters can occur at any suitable location within the system, or via cooperation of various portions of the system. By way of example, preferred control logic or circuitry of the receiver can be positioned within the actual access control system (such as Weigand or other controllers, an associated telephone or telephone system, an associated computer, etc.) or at any other suitable location capable of interacting with the corresponding transmitters and the rest of the security system.
Other objects and advantages of the invention will be apparent from the foregoing, as well as from the following specification and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flowchart illustrating a preferred embodiment of the receiver algorithm during its “normal” (non-“learning” or housekeeping) mode.
FIG. 2 is a flowchart illustrating a preferred embodiment of the receiver algorithm when information for at least one transmitter is already in memory and a new signal for the same transmitter is being processed.
FIG. 3 is a flowchart illustrating a preferred embodiment of the receiver algorithm when a new transmitter is pressed a first time.
FIG. 4 is a flowchart illustrating a preferred embodiment of the receiver algorithm when a new transmitter is pressed a second time and within a span of a predetermined period (such as 10 seconds).
FIG. 5 is a flowchart illustrating a preferred embodiment of the receiver algorithm when a new transmitter is manually “learned” in.
FIG. 6 is a flowchart illustrating one of the many alternative embodiments of the receiver algorithm during “normal” housekeeping mode.
FIG. 7 is a flowchart illustrating one of the many alternative embodiments of the receiver algorithm when a new transmitter is pressed a first time.
FIG. 8 is a flowchart illustrating one of the many alternative embodiments of the receiver algorithm when a new transmitter is pressed a second time (within a predetermined period).
FIG. 9 is a block diagram depicting a preferred method of entering information into a receiver within the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment of the invention is illustrated in the Figures, which include flowcharts of interactions between a first transmitter, a second transmitter and a receiver. The preferred method and apparatus can utilize any suitable code hopping encoder and decoder, such as the model HCS301 available from Microchip Technology Incorporated (“Microchip”). Examples of suitable hopping code technology are provided in Microchip's HCS301 product catalog and U.S. Pat. No. 5,686,904, the latter of which is hereby incorporated by reference herein regarding, among other things, its teachings of encryption and decryption algorithms and synchronization or hop code technology.
In a preferred embodiment, a single receiver may be used with hundreds to several thousand transmitters, with the number of transmitters limited only by the receiver memory. As indicated above, the invention is especially useful in applications involving a large number of users (such as in a large apartment complex, a business, or a factory). Persons of ordinary skill in the art will understand, however, that many of the benefits of the invention can be experienced in applications involving a smaller number of users.
Only the first transmitter and the second transmitter are illustrated in the Figures. Persons of ordinary skill in the art will understand, however, that the preferred method and apparatus can include third and subsequent transmitters that are learned and that operate similarly to the second transmitter.
In a preferred embodiment, the receiver is factory programmed with a 12-bit reference discrimination code. This reference discrimination information is unique and contains 12 bits of information that enables the receiver to identify and discriminate authorized from unauthorized transmitters. Authorized transmitters are similarly factory programmed with the same discrimination code.
As indicated above, preferred transmitters can take any suitable form, including (without limitation) cards, handheld electronic keys, RF or other frequency button activated devices, etc. In the preferred embodiment, the receiver first manually learns the characteristics of the first transmitter (similarly to the manual learning required with prior art systems).
The first transmitter is similar to the second transmitter, except the second transmitter has a different transmitter identification signal. By virtue of coordinated programming between the receiver (typically programmed by the installing company) and the transmitters (typically programmed or “burned” in by a manufacturer), the receiver can recognize each transmitters as belonging to an “authorized” group of transmitters. Accordingly, the “first” transmitter can be any of the authorized group of transmitters provided for a particular installation.
Furthermore, because each transmitter is typically programmed or burned with a distinct transmitter identification signal, each individual transmitter can be singled out for different security clearances or similar control processes. For example, tenants might be charged an additional fee each month for access to their complex's pool hall and gym, and their individual transmitter's code can be authorized to allow them entry through gates or doors for those areas of the complex. If they choose to not continue to pay, that code control can be changed by the landlord or manager to remove that user from the “authorized list” for that gate or door, without requiring any changes to the user's transmitter.
With regard to the preferred embodiment generally, and referring to the figures, all transmitters pass through the logic of FIG. 1 . Depending on whether the signal is emitted for the first time, the second time, the third time or third time with some problem with aspects of the signal, four different paths, represented by different portions of the figures, will be encountered. Those various paths are discussed in greater detail below, but a general overview is set forth here.
If the receiver is being manually programmed for the first time, the logic proceeds from FIG. 1 then FIG. 5 , via the connection PROG 100 . If the transmitter emits a second signal for validation, the logic proceeds from FIG. 1 through FIG. 2 , via the connection C. If the transmitter emits a third or a subsequent time and there is no problem with the signal and its processing, the logic proceeds from FIG. 1 to FIG. 2 . If there is a problem during the third or a subsequent signal emission, however, the logic proceeds from FIG. 1 , to FIG. 2 , to FIG. 3 , to FIG. 1 again, and then to FIG. 4 . If a second transmitter emits a signal for the first time, the logic proceeds from FIG. 1 , to FIG. 3 , to FIG. 1 again, and then FIG. 4 . If the second transmitter emits a signal for the second time for validation, it is processed through FIG. 1 then FIG. 2 . If the second transmitter is emitted for the third or a subsequent time and there is no problem with any aspects of the signal, processing proceeds from FIG. 1 to FIG. 2 . If there is problem with any third or subsequent transmission, processing proceeds from FIG. 1 , to FIG. 2 , to FIG. 3 , to FIG. 1 again, and then to FIG. 4 .
In a preferred embodiment of the invention, only the first transmitter has to be manually “learned” in. Once “learned” in, all subsequent transmitters are “automatically learned.” That is, subsequent transmitters are initialized without first pressing the learn button on the receiver. Turning now to the logic or circuitry illustrated in FIG. 1 , when no transmitter signal is detected, the receiver “keeps house” by continuously updating a ten (10) second timer if the “ADD” flag 20 is set. Persons of ordinary skill in the art will understand that the ten-second interval can be programmed to any suitable length without departing from the scope of the invention. They will similarly understand that the logic or circuitry illustrated in the Figures can be embodied in a wide variety and combination of chips, integrated circuits, and the like, depending on the particular installation and components utilized.
In this “housekeeping” mode, the receiverlooks for the programming switch to be pressed 30 . To “learn” the first transmitter, the receiver preferably is manually placed in “learn” mode (such as by pushing a button on the receiver) and the first transmitter is activated to send its signal (typically accomplished by the user pushing a button on the transmitter, indicated by block GC 38 in FIG. 5 ). The first signal is thereby emitted from the first transmitter and processed by the receiver. In FIG. 1 , when the “learn” button on the receiver is pushed, the “SW Push?” block 30 is triggered and the logic or algorithm 10 is moved to the condition illustrated in FIG. 5 (via the common element indicated as PROG 100 ), to begin a logic sequence.
In the preferred embodiment, the first transmitter may be provided with multiple buttons that can be programmed in various ways, including requiring a user to press a left button, a right button, or both in order to communicate with the receiver. Persons of ordinary skill in the art will understand that, as indicated above, any suitable transmitter device can be utilized within the scope of the invention.
As indicated above, the preferred transmitter signal includes 64 bits of information, although persons of ordinary skill in the art will understand that a wide variety of signals can be utilized effectively with the invention. The preferred 64-bit signal preferably contains encrypted and non-encrypted portions of the signal, including a button signal, a facility code signal, the aforementioned unique “burned-in” transmitter identification signal (these three portions preferably constitute a first subset of the entire signal) and a 32-bit hop code signal. In the preferred embodiment, the first subset of the signal uses 4 bits for the button information or signal, 12 bits for the facility code information or signal, and 16 bits for the transmitter ID information or signal. Preferably, the 32-bit hop code is encrypted and the others portions of the signal are not. The preferred 32-bit hop code is decrypted into the same 4-bit button information or signal as in the first subset, 12-bit discrimination signal and a 16-bit synchronization signal. As illustrated in FIG. 5 , upon detecting this 64-bit signal, the receiver verifies that all 64-bits of the signal are good 42 . The receiver then decrypts 44 the encryption component of the 64-bit signal and verifies that the transmitted 12-bit discrimination signal portion matches the receiver's 12-bit reference discrimination code at block 46 . If it does match, the receiver confirms 130 whether other characteristics of the first transmitter are already in its memory before writing 132 those characteristics in its electronically erasable (“EE”) memory. This writing or storing 132 of information constitutes a “learn-in” process of the receiver. Persons of ordinary skill in the art will understand that other memory will work, including RAM. However, if memory is required without power supply, then EE memory is used.
As indicated above, in the preferred embodiment, if the discrimination signal matches the reference discrimination code at block 46 , then the receiver searches its EE memory at step 130 for the same information as the emitted information. When “learning” the first transmitter, the first time that first transmitter's button is pushed, no similar information will be found in the receiver's EE memory bank (unless it has been previously programmed, as discussed in connection with alternative embodiments discussed below). In a preferred embodiment, the receiver then stores 132 in its EE memory the 4-bit button signal, the 12-bit facility code signal, the 16-bit first transmitter identification signal, and the 16-bit sync signal. Persons of ordinary skill in the art will understand that, in alternative embodiments, less than all of this information can be stored in the receiver's EE memory for later verification, use, and processing. The amount of information stored in the EE memory corresponds to a selection by the owner/manager of a balance between (1) a higher or lower level of security (more information stored corresponds to higher security) and (2) a varying degree of flexibility in terms of checking one or more signals before a subsequent transmitter is recognized and processed. In alternative embodiments, the first transmitter can be manually “learned” in at the factory. In such embodiments, when a user pushes the first transmitter button for the first time, he does not have to manually push the receiver's “learn” button.
Once the first transmitter is “learned” in the receiver, the receiver automatically recognizes other transmitters without manual intervention. In a preferred embodiment, this is accomplished by the receiver returning to housekeeping/normal operation mode after learning in the first transmitter. In this condition, there is no output signal unless the first transmitter is pressed a second time. In a preferred embodiment, all transmitters are checked two times before they are initiated, although existing technology can set this to require only one or more than two times. When the first transmitter is pushed a second time, as before, the receiver looks to see that all incoming 64 bits of information/signal is “good” (see FIG. 1 , block 42 ). Once verified, the receiver decrypts a component of the 64 bits of information and rechecks the 12-bit discrimination signal against its own 12-bit reference discrimination code to ensure that they match, at 46 . The logic which receives the 64 bit signal, decrypts the signal and verifies whether the discrimination signal matches the receiver discrimination code in the receiver is the same for FIG. 1 as it is in FIG. 5 . Therefore, the logic for FIG. 1 and FIG. 5 could be programmed to run as different sub-routines or, in the preferred embodiment, in the same sub-routine.
Persons of ordinary skill in the art will understand that, in alternative embodiments, other signals instead of or in addition to the discrimination signal could be used to validate the transmitters. To clarify, in the preferred embodiment, the first transmitter is “learned” in after the first manual push of the receiver as explained above and shown in FIG. 5 . However, there is no output unless the first transmitter is pressed a second time. In contrast, subsequent transmitters are “learned” in when they are pushed twice within a 10 second time span.
If the discrimination signal condition is satisfied (if there is a match at 46 ), the receiver verifies at 48 / 50 whether other components of the 64 bits of signal information from the transmitter are already in EE memory. If the result of verification 48 / 50 is “yes”, the circuit/logic continues through connection “C” (which is used in the figures to indicate a flow path connection of the logic rather than any action at that point) on FIG. 1 to “C” on FIG. 2 . If the result of verification 48 / 50 is “no”, the circuit/logic continues through connection “D” (which, again, is used in the figures to indicate a flow path connection of the logic rather than any action at that point) on FIG. 1 to “D” on FIG. 3 . The “first” signal of the first transmitter (like the first signal of subsequent transmitters) will result in the “D” path. A similar convention is used for “E” on FIGS. 3 and 4 .
In passing, and unless the context indicates otherwise, the abbreviations in the Figures should be interpreted as follows: FAC=Facility code; TRANS=Transmitter; CKMORE=Check more; 4 BUT=4-bit Button code; WIGOUT=Weigand controller output.
Persons of ordinary skill in the art will understand that this checking at 48 / 50 is performed to determine whether the first transmitter is already “learned” or stored in the receiver. If it is already in memory and this is the “second” check, the second check satisfies the multiple check requirement of the receiver. However, since this is the first check, the logic continues with further verification.
In alternative embodiments, and as indicated above, the option shown in the block “FAC MATCH MODE?”, in FIG. 2 , is left to the owner/manager so that flexibility is retained as to the number of signals the receiver must verify before further processing. Among other things, these settings can be programmed via a PC or similar device (not shown) connected to the security system at the installation site.
In the exercise of “manually learning” the first transmitter, then, the logic proceeds through point D, FIG. 3 , and if the “ADD” Flag 300 is not set, the logic proceeds down FIG. 3 to check the parts of the signal in a selected combination and order of information. As illustrated, the FACILITY MATCH MODE 302 logic is encountered, and it is there as a flexibility for checking just the button signal 304 or both the button signal and facility signal 306 before the validation is satisfied. Persons of ordinary skill in the art will understand that the logic through this area of the circuit can be configured to provide higher or lower levels of security (both the FAC and 4 BUT have to match, only the 4 BUT has to match, etc.). In the preferred embodiment illustrated in FIG. 3 , only the 4 BUT has to match. If it does not match, the circuit returns to CKCK 12 ( FIG. 3 ) and CKCK 12 (FIG. 1 ), and “tries” again.
If the 4-bit button information is on the “authorized” list (such as via outcomes “Y” below elements 304 or 306 , FIG. 3 ), the circuit sets the “ADD” FLAG record function 312 and at 314 saves the 4-bit BUT code, the FAC code, and the Transmitter number to RAM or other usable memory. The circuit saves the 16-bit SYNC code to RAM at 316 , sets up a 10-second timer at 318 , and returns to the CKCK transmitter click 12 (also shown at the top of FIG. 1 ). Persons of ordinary skill in the art will understand that these steps 312 , 314 , 316 , and 318 can be performed in a variety of orders.
If the receiver instead verifies “yes” at 48 / 50 (such as a second or subsequent push of the receiver), the circuit can check the parts of the signal in a variety of combinations and orders (similar to the description of elements 302 , 304 , 306 above regarding FIG. 3 ). As illustrated, the Facility Code portion of the signal is checked first at 55 , followed by the button signal (such as at 56 or 57 , depending on the result of the check at 55 ). Persons of ordinary skill in the art will understand that the logic through this area of the circuit can be configured to provide higher or lower levels of security (both the FAC and 4 BUT have to match or only the 4 BUT has to match, etc.). In the preferred embodiment illustrated in FIG. 2 , only the 4 BUT has to match. If it does not match, the circuit returns to CKMORE 58 ( FIG. 2 ) to CKMORE 48 (FIG. 1 ), and “tries” again.
When the first transmitter is pressed a second time, algorithm circuitry in the transmitter increases the sync number of its second signal above the sync signal of its original signal, this is designated as a second-second sync signal. In the preferred embodiment, the transmitter's sync number increases by one each time a button is pushed. Although persons of ordinary skill in the art will understand that larger increments may also work and will satisfy the same criteria (i.e., that the transmitter's subsequent sync signal be larger than its previous signal). Once a check against the receiver memory for similar information is performed and satisfied (such as illustrated by the “Y” result coming from blocks 56 or 57 , FIG. 2 , and button, facility and transmitter identification number of block 61 ), the receiver compares the “new” sync number with the sync number previously stored for that transmitter. If the new sync number is larger and it is within 128 of the prior sync number 64 , the new sync number is stored in the receiver EE memory and a clearance signal is output for clearance. This is shown in FIG. 2 as a “WIGOUT” output. In a preferred embodiment, the new sync number must be between 1 and 128 larger in number than the prior sync number, although persons of ordinary skill in the art will understand that other numbers will work as well and the numbering scheme is limited only by the amount of receiver memory. Likewise, instead of a WIGOUT output to a weigand controller, other signals and other access controllers may be configured and used, such as a computer or a telephone system.
In situations where the first transmitter is accidentally pressed while it is carried in a purse or a pocket, the sync number in the transmitter increases the same number of times as the number of accidental pressing. If this number is 129 or larger, the next time the receiver receives a signal from this first transmitter, the receiver will not generate an output. If it is 128 or less, the receiver and transmitter go off without further verification (see FIG. 2 blocks 64 and 65 ) and an output signal is sent. Instead, if it is between 129 and 16,000, the receiver requires that the first transmitter verifies itself again before given clearance.
The process is initiated by setting the “SYNC OFF FLAG” 67 . A person of ordinary skill in the art will understand that a 16,000 limit is arbitrary and that other numbers will suffice, limited only by the receiver memory. In a preferred embodiment, if the new received sync signal is above 16,000, the receiver ignores the 64 bit information and resets itself to housekeeping mode. A sync signal outside of this range cannot be verified and is assumed to come from an illegal transmitter. Likewise, if the 64 bit information and the 12 bits discrimination signal do not match, then the transmitter cannot be verified and is assumed to be from an illegal transmitter. Where a new 64 bit information with a sync signal between 129 and 16,000 of the prior sync signal is received, the first transmitter is “auto learned” as if transmitted for the first time. In this case, on the logic moves to “SET ADD” 69 and the button signal, facility code signal, first transmitter signal and new sync signal or second-second sync signal are written to random access memory (“RAM”) ( FIG. 3 block 314 and 316 ) and a 10 second timer is set 318 . The logic then looks for a new signal 12 . When a follow up signal is received within the next 10 seconds, the receiver again verifies the 64 bit signal 42 , decrypts the signal 44 and verifies the discrimination signal for matching 46 . If satisfied, the receiver further checks that the incoming button signal, facility code signal, first transmitter signal and second-second sync signal matched the ones just saved in RAM 61 (see FIG. 4 ). The logic moves to FIG. 4 because the “ADD FLAG” was set in FIG. 3 .
During the verification process for a sync number that is out of range, the logic proceeds first by verifying that the new sync number is in the range of the one previously stored 72 , FIG. 4 . Since it is, because this is a second signal emitted within 10 seconds, the receiver moves the logic to block 86 and stores the first-second subset including the 4 bit BUT signal, 12 bit FAC code signal and 16 bit first transmitter identification signal and 16 bits sync signal, or first-second sync signal, in EE memory 86 . The receiver then clears the “ADD” flag 88 and sends a WIGOUT signal 68 . In a preferred embodiment, the second sync signal, must be within 2 of the first sync number that was just stored in RAM. However, a person of ordinary skill in the art will understand that other higher increments may also serve the same purpose.
If the new sync number is not the same as the previous sync number 72 , the old sync number in the receiver is increased 74 , and a second check of the old sync number against the new sync number takes place. This logic verifies that when a new signal is emitted within 10 seconds of the old signal, the new sync number is 2 of the old sync number. Once verified, it then stores the first-second subset as described above.
In real life situation, if a user encounters the above scenario wherein the user presses his transmitter button and nothing happens, he will undoubtedly press it again, probably within 10 seconds. In doing so, he will gain access to whatever location or thing he desires without having to manually reset the receiver. This is the case described above.
When a second user with a second transmitter is pressed for the first time, like before, the second transmitter emits a 64 bit signal which includes 4 bit button signal, 12 bit facility code signal, 16 bit second transmitter signal and 32 bit hop code signal (block 42 , FIG. 1 ). The receiver decrypts the signal and verifies that the 12 bit discrimination signal matches the 12 bit reference discrimination code 46 . The receiver then processes the other information and determines whether the second transmitter is already in memory 50 . Since this second transmitter has not been entered, no “SET FLAG” has been set 300 , so the receiver proceeds to verify whether there it is in a “FAC MATCH MODE” 302 . If so, both the 4 BUT and FAC are verified, if not, only the 4 BUT signal is verified 304 . Once satisfied, the logic proceeds with setting the “ADD FLAG” 312 and stores the BUT, FAC and TRANS signals to RAM 314 .
As with the first transmitter, the logic will not emit an output unless the second transmitter is verified a second time. Thus, a 10 second timer is set 318 and the logic looks for a second signal 12 . If the transmitter is pressed again within 10 seconds, the 64 bit signal is checked 42 , the receiver decrypts 44 the signal and the discrimination signal is verified 46 (FIG. 1 ).
Since this second transmitter is not in EE memory, the logic proceeds to “ADD FLAG SET?” 300 of FIG. 3 . In determining that it is set, because this is a second emission within 10 seconds of the first, and the flag was set during the first emission, the logic moves to block 61 , FIG. 4 . The receiver then verifies that the second signal from the second transmitter has a same second-second subset signal (which include the button signal, facility code signal and second transmitter signal) as the ones previously emitted and stored in RAM 61 . The new sync signal, also known as a second-second sync signal is then verified and stored in memory if it is 2 of the previous sync signal. The receiver performs this functions by increasing the previously saved sync number 70 . The logic then determines whether the saved sync (with the increase 70 ) equals the newly emitted sync 72 . If they are equal, the logic moves to block 80 “SYNC OFF FLAG SET?”. Since the flag is set, it writes the button signal, facility signal, transmitter identification signal and new sync number to EE memory 86 , clears the “ADD” flag 88 and sends an output signal 68 .
If the second transmitter is pressed a third time and emits a second-third signal, that signal is processed through the logic of FIG. 1 and FIG. 2 the same way as did the second signal of the first transmitter. The second-third signal, as before, includes sub-components. They consists of the same button signal, the same facility code signal, the same transmitter identification signal, the same discrimination signal and a new second-third sync number. In a preferred embodiment, after a receiver has been “learned” in, either automatically (as in the second transmitter) or manually (as in the first transmitter), a user only needs to push the transmitter once for entry. The only exception is when the sync number of the user transmitter is 129 times larger but 16,000 times smaller than the prior sync number. Under that scenario, the user must push the transmitter a second time and within 10 seconds of the first push in order to “re-learn” the transmitter and gain access, as described above.
In an alternative embodiment, the logic just described does not have to be located in a separate receiver. Instead, a receiver could be a phone system and the phone system itself may determine admittance, not a weigand controller. Alternatively, the logic may reside in a computer or some other device that is capable of making a final determination. Still another alternative, the logic may reside in a device but that device does not make a final determination. A person of ordinary skill in the art will understand that the logic described in the foregoing permits automatic learning in a security system and that ultimate clearance determination could be performed by a multitude of device currently in the prior art. As such, the receiver could be any one of those devices or a separate device connected to one of those controllers.
In an alternative embodiment, all button signals, facility code signals and a range of transmitter identification signals are manually programmed into the receiver (see FIG. 9 ). When the first transmitter is then used for the first time, it must be pushed twice within 10 seconds in order to validate the first transmitter. If so, only the sync signal of the first transmitter is written to EE memory. Referring to FIG. 6 , when no signal is detected, the receiver keeps house by updating a 10 second timer. In this mode, the receiver waits for a user to input program features.
In this alternative embodiment, as before, the receiver keeps house by continually updating a 10 second timer, FIG. 6 block 308 . Once a button on the receiver keypad 312 is pushed, the logic moves to FIG. 9 . Information for a group of transmitters are then entered by a user 500 . The entered information is entered via a keypad located on the receiver. The entry includes the button signal, facility code signal and a range of transmitter identification signals 504 . In addition, the user may enter a time zone for that entry to further restrict access to a particular transmitter, several transmitters or a range of transmitters, among other things, for entry during a particular period only. Once entered, the button signal, facility code signal and transmitter identification signal for the first transmitters and all subsequent transmitters within that range of transmitter identification signal are written to EE memory 506 .
Back in FIG. 6 , when the first transmitter is pressed for the first time, the receiver verifies that all 64 bits signal is good 316 (for ease of illustration, only the first transmitter is discussed since all transmitters are validated the same way). It then decrypts 318 the encrypted portion of the signal and verifies that the incoming 12 bits discrimination signal matches its 12 bits reference discrimination code 320 . The receiver determines whether this first subset signal is already in memory 322 . If yes, it reads the time zone for the first transmitter 324 .
Since this is a first emission, the “SET SYNC OFF FLAG” is set (see FIG. 7 block 396 ) to begin learning the first transmitter, specifically the sync number of the first transmitter. The logic then moves to block 354 since this is the first time this transmitter is used. “SET SYC” 356 is triggered and the first subset including the button signal, facility code signal and first transmitter identification signal and the first sync signal is then saved in RAM 398 and a 10 second timer is triggered 402 . The receiver then waits for a second validating signal at “CKCK” 300 . In a preferred embodiment, 10 seconds is used in conjunction with two successive pushes of a button for validation. Persons of ordinary skill in the art will understand that different combinations may suffice such as waiting 15 seconds between two successive pushes or 5 seconds between three successive pushes. The goal is to require validation by having additional looks, including a second look, at the incoming signal before the transmitter is validated.
When the first transmitter is pressed a second time, emitting a first-second signal, and within 10 seconds, the 64 bits signal (including a first-second subset signal) is checked, FIG. 6 block 316 , part of the signal gets decrypted 318 and the discrimination signal is verified 320 . Since the first subset signal and first sync signal are now in RAM 398 , the first-second subset signal is compared with the previous first subset signal (see FIG. 8 block “ISEQ” 360 ). IF the previous saved sync equals the new first-second sync 422 , the “SYNC OFF FLAG” 432 is cleared and the logic moves to output a command 368 . If the two sync numbers do not match, the new sync is saved 426 and the logic looks for a second check to verify 300 .
If the signals matched the logic moves back to FIG. 7 block 368 . The new sync signal, also known as a first-second sync signal, is saved to EE memory 366 . In the preferred embodiment, the first-second sync signal is saved to EE memory only if it is within 2 of the first sync signal. The time zone is again checked 370 and 372 . If the transmitter is valid and the time zone is proper, the transmitter signal is put in a transaction buffer for output clearance. Although the receiver is now satisfied and will output a clearance signal, persons of ordinary skill in the art will understand that a variety of actions can occur in addition to or instead of outputting a clearance signal, such as printing the transaction for record 379 .
The receiver is now reset to housekeeping (“CKCK” FIG. 7 block 300 ) and monitors for incoming signals. If the first transmitter is pressed again, first-third signal, the logic, as before, verifies the 64 bit signal, decrypts the signal and checks whether the discrimination signals match. It then moves to determine whether the first-third subset signal is in memory 322 . Since the information for this transmitter is already in memory, the “SYNC OFF FLAG” 352 is not set. Also, since this is not the first time this transmitter is used 354, the logic bypasses all the other sequence and only determines whether the new sync number, first-third sync number, is within 128 (block 364 ) or is between 129 and 16,000 (block 390 ), as described before. If it is within 128, the new sync number is saved to memory 366 and the logic sends the signal for output 376 . If it is within 16,000, the “SYNC OFF FLAG” is set and the first-third signal and the new sync number are saved to RAM 398 for another validation 300 .
In some of the many alternative embodiments of the invention, a valid time zone can operate a relay for the clearance output. In addition, all clearance output or transactions can be saved to a transaction buffer, for printing, record-keeping, or other purposes.
While the preferred embodiment and method of the invention has been described with some specificity, the description and drawings set forth herein are not intended to be delimiting, and persons of ordinary skill in the art will understand that various modifications may be made to the embodiments and methods discussed herein without departing from the scope of the invention, and all such changes and modifications are intended to be encompassed within the appended claims. | A security system for control access of multiple users to a selected area combines rotating electronic security code or equivalent technology with an automatic self-learning receiver. The first transmitter is “learned” by the receiver manually, but subsequent transmitters are learned without the need for actuating the conventional “manual learn” mode of the receiver. Instead, by simply sending the transmit signal twice within a fixed time period, users of the subsequent transmitters use “self-learning” circuitry (interposed between conventional transmitter and receiver technology) in a way that is relatively transparent to the user. Other aspects of conventional systems are provided, such as separate control via computer or otherwise of an authorized list of uniquely-identified transmitters. In alternative embodiments, even the first transmitter/controller can be programmed into the receiver (such as at the time of manufacturing or installing the system). | 6 |
This application is a Continuation of application Ser. No. 10/036,377, filed on Jan. 7, 2002, which claims priority to Korean Patent Application No. 2390/2001, filed in Korea on Jan. 16, 2001. The entire disclosures of these applications are hereby incorporated in their entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a mobile communication terminal, and more particularly, to apparatus and methods of selecting special characters in a mobile communication terminal.
2. Background of the Related Art
Generally, as the functions of mobile communication terminals (hereinafter abbreviated “terminal” or “terminals”) develop, character input functions are more frequently used. Such functions used to be just for inputting, for example, names into a phone directory. Lately, terminals have functioned as a personal digital assistant (PDA), as a time scheduler, for Internet communication, and the like, as well as a phone directory, thereby requiring more character input. Therefore, in order to provide users with various character input functions, character inputs for various languages are required. Specially, when alphabet letters are edited in an editing mode, inputs for special characters, such as alphabet letters from the European alphabet, for example, “ë, Ë or e”, are required as well as the basic English language 26 letter alphabet.
A related art method of selecting special characters includes the steps of selecting a predetermined alphabet letter and selecting an European alphabet letter by a toggle method using a predetermined key during a special character input mode.
For instance, to input an European alphabet letter “À”, as shown in Table 1 below, a user, first pushes a key “2(A,B,C)” on a key pad to input the alphabet letter “A”, and then pushes a predetermined key, in this case “O”, to select a special character input mode. Once the user selects the special character input mode, a plurality of European alphabet letters, which are stored as related to or associated with the alphabet letter “A”, are displayed on an LCD screen, as shown in Table 2 below. In this case, “_” indicates the location of the cursor, that is, the location where the special character is required, and two or three European alphabet letters are displayed on the screen therebelow.
TABLE 1
Store phone number
0123-456-7890
Please input name!
MOOA —
TABLE 2
Store phone number
0123-456-7890
Please input name!
MOOA —
ÀÁ Â
When a plurality of the European alphabet letters are displayed, the user pushes the key “0”, known as the “toggle key”, repeatedly to search the displayed European alphabet letters. That is, when the key “0” is pushed repeatedly, the plurality of the European alphabet letters show up in the following order: ÀÁ Â. The user then selects the desired “À” among the toggled European alphabet letters.
However, this related art method of searching for special characters requires a minimum of two key inputs (2,0) and a maximum of seven key inputs (2,0,0,0,0,0,0) to select the desired European alphabet letter. That is, the user has to push the keys “2” and “0” to select “À”. Further, the user has to push the keys “2” and “0”, and then push the key “0” successively five times to select “Å”.
Moreover, the related art method of searching for special characters requires the user to push the key “0” an additional five times if the user mistakenly passes the search location of the desired European alphabet letter. Furthermore, when a particular European alphabet letter is not available, the user will only recognize this through a plurality of trial and error inputs. Consequently, the related art method of searching for special characters is inconvenient and requires a plurality of key manipulations, thereby preventing fast character input.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.
SUMMARY OF THE INVENTION
An object of the invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter.
The invention is directed to a method of selecting special characters in a mobile communication terminal that substantially obviates one or more of problems of the related art method discussed above.
Another object of the invention is to provide a method of selecting special characters in a mobile communication terminal having convenient key manipulation.
Yet another object of the invention is to provide a method of selecting special characters in a mobile communication terminal which is less time consuming than related art methods with less key manipulations.
A further object of the invention is to provide a method of selecting special characters in a mobile communication terminal utilizing software, without having to provide the terminal with additional hardware.
To achieve at least the above objects and other advantages in whole or in part and in accordance with the purposes of the invention, as embodied and broadly described herein, a method of selecting special characters in a mobile communication terminal according to the invention includes inputting an alphabet letter in an editing mode, displaying a plurality of European alphabet letters corresponding to the inputted alphabet letter, wherein a series of numbers are associated with the European alphabet letters, respectively, and selecting one of the European alphabet letters using a numeral key on a key pad.
To further achieve at least the above objects and other advantages in whole or in part and in accordance with the purposes of the invention, as embodied and broadly described herein, a method of selecting special characters in a mobile communication terminal includes inputting an alphabet letter, sensing activation of a mode conversion key, displaying input-available European alphabet letters on an additional screen if activation of the mode conversion key is sensed, and selecting one of the displayed European alphabet letters.
To even further achieve at least the above objects and other advantages in whole or in part and in accordance with the purposes of the invention, as embodied and broadly described herein, a method of selecting special characters in a mobile communication terminal includes storing a set of European alphabet letters in a memory, inputting an alphabet letter to be changed, sensing activation of a mode conversion key, displaying a plurality of European alphabet letters corresponding to the inputted alphabet letter on a pop-up window when activation of the mode conversion key is sensed, wherein the European alphabet letters are read from the memory, and selecting a desired one of the displayed European alphabet letters.
Additionally, to achieve at least the above objects and other advantages in whole or in part and in accordance with the purposes of the invention, as embodied and broadly described herein, apparatus for selecting special characters in a mobile communication terminal include means for inputting an alphabet letter, means for displaying a plurality of European alphabet letters corresponding to the inputted alphabet letter, wherein a series of numbers are associated respectively with each of the European alphabet letters, and means for selecting one of the European alphabet letters.
Moreover, to achieve at least the above objects and other advantages in whole or in part and in accordance with the purposes of the invention, as embodied and broadly described herein, apparatus for selecting special characters in a mobile communication terminal include means for inputting an alphabet letter, means for determining whether a mode conversion key has been activated, means for displaying European alphabet letters on an additional screen if it is determined that the mode conversion key has been activated, means for selecting one of the displayed European alphabet letters.
To even further achieve at least the above objects and other advantages in whole or in part and in accordance with the purposes of the invention, as embodied and broadly described herein, apparatus for selecting special characters in a mobile communication terminal include means for storing a set of European alphabet letters, means for inputting an alphabet letter to be converted to a European alphabet letter, means for determining whether a mode conversion key has been activated means for displaying a plurality of European alphabet letters corresponding to the inputted alphabet letter on a pop-up window when it is determined that the mode conversion key has been activated, wherein the European alphabet letters are read from the memory; and means for selecting a desired one of the displayed European alphabet letters.
Further, to achieve at least the above objects and other advantages in whole or in part and in accordance with the purposes of the invention, as embodied and broadly described herein, a computer-readable medium is provided having stored thereon a sequence of instructions which, when executed by a processor, cause the processor to perform the steps of determining whether an alphabet letter has been input in an editing mode, displaying a plurality of European alphabet letters corresponding to the inputted alphabet letter, wherein a series of numbers are associated respectively with each of the European alphabet letters; and determining whether one of the European alphabet letters has been selected using a numeral key on the keypad.
Furthermore, to achieve at least the above objects and other advantages in whole or in part and in accordance with the purposes of the invention, as embodied and broadly described herein a computer-readable medium is provided having stored thereon a sequence of instructions which, when executed by a processor, cause the processor to perform the steps of determining whether an alphabet letter has been inputted, determining whether a mode conversion key has been activated, displaying European alphabet letters on an additional screen if it is determined that the mode conversion key has been activated, and determining whether one of the displayed European alphabet letters has been selected.
Additionally, to achieve at least the above objects and other advantages in whole or in part and in accordance with the purposes of the invention, as embodied and broadly described herein a computer-readable medium is provided having stored thereon a sequence of instructions which, when executed by a processor, cause the processor to perform the steps of storing a set of European alphabet letters in a memory, determining whether an alphabet letter to be converted to a European alphabet letter has been inputted, determining whether a mode conversion key has been activated, displaying a plurality of European alphabet letters corresponding to the inputted alphabet letter on a pop-up window when it is determined that the mode conversion key has been activated, wherein the European alphabet letters are read from the memory; and determining whether a desired one of the displayed European alphabet letters has been selected.
Also, to achieve at least the above objects and other advantages in whole or in part and in accordance with the purposes of the invention, as embodied and broadly described herein, apparatus for selecting special characters in a mobile communication terminal include a key input unit configured to allow input of an alphabet letter by a user, a display configured to display a plurality of European alphabet letters corresponding to the inputted alphabet letter, wherein a series of numbers are associated respectively with each of the European alphabet letters and a user may select a desired European alphabet letter by pressing a key on the key input unit designating the number respectively associated with the desired European alphabet letter.
Further, to achieve at least the above objects and other advantages in whole or in part and in accordance with the purposes of the invention, as embodied and broadly described herein, apparatus for selecting special characters in a mobile communication terminal include a key input unit configured to allow input or an alphabet letter by a user, a controller that determines whether a mode conversion key has been activated, a display configured to display European alphabet letters on an additional screen if the controller determines that the mode conversion key has been activated, wherein a series of numbers are associated respectively with each of the European alphabet letters and a user may select a desired European alphabet letter by pressing a key on the key input unit designating the number respectively associated with the desired European alphabet letter.
Furthermore, to achieve at least the above objects and other advantages in whole or in part and in accordance with the purposes of the invention, as embodied and broadly described herein, apparatus for selecting special characters in a mobile communication terminal include a memory configured to store a set of European alphabet letters, a key input unit configured to allow input of an alphabet letter to be converted to a European alphabet letter a controller configured to determine whether a mode conversion key has been activated, a display configured to display a plurality of European alphabet letters corresponding to the inputted alphabet letter on a pop-up window when the controller determine that the mode conversion key has been activated, wherein the European alphabet letters are read from the memory and wherein a series of numbers are associated respectively with each of the European alphabet letters and a user may select a desired European alphabet letter by pressing a key on the key input unit designating the number respectively associated with the desired European alphabet letter.
It is to be understood that both the foregoing general description and the following detailed description of the invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
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.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in detail with reference to the following drawings in which like reference numerals refer to like elements. The 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 schematic block diagram of a mobile communication terminal according to an embodiment of the invention;
FIG. 2 is an operational flowchart illustrating a method of selecting an European alphabet letter according to an embodiment of the invention;
FIG. 3 shows an exemplary set of European alphabet letters and corresponding English alphabet letters;
FIG. 4A is a schematic diagram of a display showing an editing mode of a mobile communication terminal according to an embodiment of the invention;
FIG. 4B is a schematic diagram of a display showing a plurality of European alphabets displayed on a pop-up window display according to an embodiment of the invention; and
FIG. 4C is a schematic diagram of a display showing an input alphabet letter replaced by a specific European alphabet letter.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Reference will now be made in detail to embodiments of the invention, examples of which are illustrated in the accompanying drawings.
FIG. 1 is a schematic block diagram of a mobile communication terminal according to an embodiment of the invention. Referring to FIG. 1 , a controller 100 performs an overall control operation for the terminal and a control operation to edit a European alphabet letter. A key input unit 110 functions as an input device for user data and includes a plurality of numeral keys and various function keys. A display unit 120 , which in this embodiment is a liquid crystal display (LCD), indicates a state of the terminal, and illustrates steps of the program.
A memory 130 includes a ROM that stores an operation program, and an EEPROM and RAM that store user data. The memory 130 also has a character string storage area. A signal processor 140 modulates a voice signal input from a microphone into voice data, and outputs the voice data to a RF unit 150 . The signal processor 140 also demodulates voice data input from the RF unit 150 into a voice signal and outputs the voice signal to a speaker. In a CDMA (code division multiple access) mobile communication system, the signal processor 140 samples a voice signal input through a microphone, converts the voice signal into a PCM (pulse code modulated) signal, and voice-encodes the PCM signal again. The voice-encoded signal undergoes processing, such as quadrature modulation.
The RF unit 150 transmits/receives various data through an antenna in accordance with instructions from the controller 100 . In CDMA, the quadrature-modulated signal is modulated into an analog signal and then the analog signal, which is carried on an RF signal, is transmitted to a base station.
FIG. 2 illustrates an operational flowchart for selecting a European alphabet letter according to the invention in a mobile communication terminal such as that shown in FIG. 1 .
Referring to FIG. 2 , specific alphabet letters, for example, A, C, E, I, N, O, U, Y, a, c, e, i, n, o, u, and y, divided into Capital and small letters are stored as a character set of European alphabet letters in the memory 130 , as shown in FIG. 3 . However, the invention is not limited to the European alphabet but may utilize other character sets relevant to other respective countries and having different valid ASCII, such as other European countries, South American countries, etc.
FIG. 2 is an operational flowchart illustrating a method of selecting specific characters, in this case a European alphabet letter, according to an embodiment of the invention. As shown in FIG. 9 , in step S 10 , the controller 100 checks whether an editing mode has been selected via the key input unit 110 . The editing mode is a mode in which edited letters, such as for phone number storage, schedule storage, memo storage, Internet access, etc., are input into the mobile communication terminal. A selected editing mode, such as that shown in FIG. 4A , is displayed on the display unit 120 . During the editing mode, a mode conversion key and a save key are displayed at lower left and right hand areas on the display, respectively.
A user inputs an alphabet letter in step S 11 . For example, when a user inputs the alphabet letter “N” in the editing mode, the controller 100 next checks at step S 12 whether a mode conversion key has been activated, or pressed. If the user fails to activate the mode conversion key, the controller 100 proceeds to step S 17 to check whether an end key has been activated, or pressed. if, in step S 17 it is determined that the end key has not activated, the process goes back to step S 11 and awaits input of a next alphabet letter.
Thereafter, the user inputs the alphabet letter “a” in order to input the European alphabet letter “á”. If the mode conversion key is selected again while the cursor is on the alphabet letter “a”, the controller 100 checks, in step S 13 , whether the alphabet letter “a” is changeable into a European alphabet letter. The changeable European alphabet letters according to this exemplary embodiment are shown in FIG. 3 .
As a result of the checking step, if the inputted alphabet letter is changeable into a European alphabet letter, the controller 100 reads a plurality of European alphabet letters corresponding or relating to the alphabet letter “a” from the character set storage area of the memory 130 . The controller 100 displays the read European alphabet letter on a specific area of the display unit 120 . That is, plurality of the European alphabet letters are displayed on an extra area of the display unit 120 , or a pop-up window, as shown in FIG. 4B . In this case, a series of numbers are associated with the respective European alphabet letters on the display, as shown in FIG. 4B , so that the European alphabet letters may be selected using numeral keys 0 to 9 of the keypad. When the pop-up window appears, the mode conversion key and the cancel key show up on the display at lower left and right-hand areas of the display.
Thus, the user can input the European alphabet letter “á” by pressing the key “2” after having ascertained that the desired European alphabet letter “á” exists among the European characters displayed on the pop-up window. On the other hand, if the desired European alphabet letter is not in the group of European alphabet letters displayed, the user may select another input mode by selecting the mode conversion key at the lower left area of the display. If the user selects the cancel key at the lower right area of the display, the program returns to the editing mode, as shown in FIG. 4A .
In step S 15 , the controller 100 checks whether the user has input, or pressed a selected key (character key on the key pad) associated with a specific European alphabet letter. For example, if the user presses the key “2”, the alphabet letter “a” is replaced by the corresponding European alphabet letter “á”, as shown in FIG. 4C .
Thereafter, the above steps are repeated so that the user may input other alphabet and European alphabet letters. When the user presses the save key after completion of the input steps, the controller 100 stores the corresponding user data in the memory 130 .
The invention enables a user to input European alphabet letters with a couple of key manipulations, i.e., by activations of a mode switch key and a character key on the key pad, and by displaying available European alphabet letters, to which a series of numbers are associated respectively, on an auxiliary screen, or pop-up window.
Accordingly, the invention enables a user to select a European alphabet letter conveniently with a reduced number of key manipulations in comparison to related art methods.
Moreover, the invention enables a user to input a European alphabet letter without additional hardware by adding a European alphabet letter mode to a terminal having an English mode, a Numeral mode, and an ASCII mode.
The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the invention. The present teaching can be readily applied to other types of apparatuses. The description of the invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. | Apparatus and methods of selecting special characters in a mobile communication terminal are provided. The method includes storing a set of European alphabet letters in a memory, inputting an alphabet letter to be converted in a European alphabet letter, determining a mode conversion key has been activated, displaying a plurality of European alphabet letters corresponding to the inputted alphabet letter on a pop-up window when it is determined that the mode conversion key has been activated, wherein the European alphabet letters are read from the memory, and selecting a desired one of the displayed European alphabet letters. | 6 |
BACKGROUND OF THE INVENTION
It has become a widely accepted practice in the textile industry to treat textile materials, especially cellulosic materials such as cotton or rayon, but also wool, silk and various synthetic fibers, for the purpose of rendering the material resistant to the action of flame and heat. Such practice has assumed increasing importance with the adoption of legislation designed to protect the public against the hazards of flammable fabrics in articles of clothing, toys, household articles such as curtains and drapes, and the like.
A broad group of flameproofing agents or flame retardants which have received extensive attention is represented by the inorganic and the organic phosphorus compounds. One theory to explain why such phosphorus compounds function as flame retardants for substrates, especially organic substrates such as cellulose, is that they produce phosphorus pentoxide during exposure to flame. The liberated P 2 O 5 , which is a Lewis acid, thereupon acts on the organic fiber substrate to dehydrate it, forming water and carbon, which are less flammable than the gaseous and tarry products of ordinary degradation. Another theory is that the phosphorus compounds change the path of degradation to prevent the formation of levoglucosan, to increase the amount of carbon, water and carbon dioxide and to reduce the ammount of flammable, volatile gases and flammable tars. Examples of agents which have been employed in the prior art for this purpose include salts of orthophosphoric acid and other acids of phosphorus, such as diammonium phosphate, and salts formed from mixtures of an aliphatic organic base and an acid of phosphorus. The acids of phosphorus which have been used to form salts with organic bases include, for example, orthophosphoric acid, phosphoric acid, pyrophosphoric acid, and methyl phosphonic acid. Typical organic bases include cyanamide and urea. These salts may be employed per se, or in association with haloalkyl phosphonic acid derivatives and phosphate esters, which are also flameproofing agents.
Another type of phosphorus-containing flameproofing agent comprises the haloalkylphosphonic acids and their salts, such as chloromethylphosphonic acid. These compounds react with a portion of the hydroxyl groups of the cellulose or other hydroxyl-containing fiber molecule, thereby forming ethers and chemically modifying the textile material by incorporating phosphorus into the fibers.
One of the drawbacks of such phosphorus-containing flame retardants has been their ability to undergo ion exchange when the textile material is laundered in water containing alkali metal or alkaline earth metal compounds which causes a loss of fire retardance. Thus, textiles can be rendered fire retardant by the application of a compound such as diammonium phosphate to form a monophosphate ester of cellulose, Cell-O-P(O)-(OH) 2 , or an ammonium salt thereof. However, this fire retardance can be lost in a single laundering in water containing even small amounts of alkali metal or alkaline earth metal compounds, because of the conversion of this readily decomposable monophosphate ester or ammonium salt into an alkali metal or alkaline earth metal salt which does not decompose readily into P 2 O 5 when heated.
These ion exchange properties are exhibited by a number of phosphorus flame retardants. The phosphorus can be in a compound linked chemically to the cellulose or in a compound which is deposited as an insoluble deposit in or on the textile fibers. The groups which are usually associated in ion exchange properties are acidic OH groups. But, ion exchange can take place with other groups which are capable of linking with metal ions such as alkali metal and alkaline earth metal ions. The groups can be attached to the phosphorus atoms or attached to other atoms which are on the textile.
Normally the metal ions that cause the most trouble during laundering are the so-called hard water ions such as calcium and magnesium. We will refer to hard water ions as being the ones causing loss of fire retardance, but it is to be understood that both the usual hard water ions and ions such as sodium and potassium can be ion exchanged by the fire retardant fabric with subsequent loss of fire retardance. The process of this invention protects the fabric not only from hard water ions, but also all of the alkali metal and alkaline earth metal ions.
No matter what the mechanism of the ion exchange, the effect on the fire retardance of the textile laundered in hard water is the same: a loss of fire retardance associated with a pick-up of hard water ions. This is theoretically due to these metals, such as calcium, tying up phosphorus during the combustion process so that phosphorus may not function as a flame retardant.
Thus, for example, it is known that cellulose can be phosphonomethylated by treatment with the sodium salt of chloromethylphosphonic acid in accordance with the equation:
ClCH.sub.2 P(O)(ONa).sub.2 + Cell-OH + NaOH → Cell-OCH.sub.2 P(O)(ONa).sub.2 + NaCl.
When the treated textile is acidified with an acid such as hydrochloric acid, the sodium salt is transformed into the acid form of phosphonomethylated cellulose which has two free acid groups on the phosphorus atom. Whether it is in the salt form or in the free acid form, it is capable of picking up calcium ions by ion exchange when it is laundered in hard water, to form a calcium phosphonate salt which does not readily decompose.
A similar tendency toward ion exchange with calcium and other ions in hard water is found in textiles treated with salts or organic bases and phosphoric acid, which present some acid groups for ion exchange.
It has been proposed (see U.S. Pat. No. 2,728,680) to apply a mixed solution of a soluble chloride of tetravalent titanium and a soluble inorganic phosphate to cellulosic material as a flame retardant. The mixture is gelatinized and adhered onto the fabric. The solutions, however, only contain a small amount of phosphorus (0.02 to 0.17 part of phosphorus per part of titanium) and attempts to add higher proportions of phosphorus to such titanium tetrachloride solutions result in precipitation of titanium phosphate. The addition to the solution of antimony trichloride, another known flame retardant agent, is thus recommended in the patent to improve the fire resistant properties of the treated fabric, particularly after laundering.
In U.S. patent application Ser. No. 307,796, filed Nov. 20, 1972, now U.S. Pat. No. 3,827,907, there is disclosed a novel and efficacious method whereby the durability of flame retardant properties of textile materials treated with phosphorus-containing agents affixed to the material in an amount of from about 0.5 to about 5, percent of phosphorus based on the weight of the material is improved by the aftertreatment of the textile material with a salt of a heavy metal or a transition metal, i.e., a metal which is in Group I-B, IV-A, IV-B, V-A, V-B, VII-B and VIII of the Periodic Table of Elements. Titanyl sulfate has been found to be a particularly efficacious metal salt for use in that aftertreatment process.
The treatment disclosed in that aforesaid application Ser. No. 307,796, serves to increase the flameproofing effect of the flameproofing agent and protect it against ion exchange or other effects of exposure to hard water, thereby promoting flame resistance and increasing its retention over a large number of launderings.
While the treatment disclosed in the aforesaid application represents a substantial improvement in the art, the search has continued for improved methods for imparting durable flame retardance to cellulosic fiber-containing textile materials. It has been found, for example, that treatments applied to a textile material to obtain acceptable flame retardance properties may adversely affect other properties of the textile material. The textile material may shrink a substantial amount (e.g., about 10 or 20 percent or more) during treatment with a phosphorus-containing flame retardant material as compared with an untreated textile material. Other properties of the textile material may also be adversely affected.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of this invention to provide an improved method for imparting durable flame retardant properties to cellulosic fiber-containing textile materials which substantially reduces or alleviates the above-noted problems of the prior art.
It is a specific object of this invention to provide an improved method for imparting durable flame retardant properties without appreciable shrinkage of the treated textile material and the resulting product.
In accordance with one aspect of the present invention, there is provided in a process wherein durable flame retardant properties are imparted to a web of cellulosic or protein fiber material by treatment thereof with a phosphorus-containing flameproofing agent which is affixed to the fiber in an amount of from about 0.5 to about 5, percent phosphorus by weight of the fiber and which has ion exchange capability and thereafter applying to said treated web a titanyl sulfate solution to improve the durability of the flame retardant properties, the improvement which comprises applying said phosphorus-containing flameproofing agent in correlation with antimony oxide and a polymeric halogen-containing material to affix on the fiber an amount of from about 0.5 to about 10, percent of the total of (phosphorus plus antimony plus halogen) by weight of the fiber whereby said phosphorus-containing flameproofing agent is applied in reduced amounts without substantially adversely affecting the flame retardant properties of the treated web.
In accordance with another aspect of the present invention, there is provided the product of the above process.
The essence of the particular invention is the discovery that the relatively large amount of phosphorus affixed to the flame retardant textile material in prior processes (to achieve flame retardancy) can adversely affect other physical properties and that part of the phosphorus can be replaced with a mixture of antimony oxide and a polymeric halogen-containing material to achieve acceptable flame retardant properties without adversely affecting these other properties.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The materials or substrates to which the present invention is applicable include textiles or webs formed of cotton and other cellulose fibers such as linen, regenerated cellulose, viscose rayon, and partially etherified or esterified cellulosic materials; other forms of cellulosic material such as paper or wood products; proteinaceous textiles, such as wool, silk, or fiber made from casein; as well as textile blends containing one or several of the foregoing fiber types. The textile materials may be in the form of fibers, yarns, fabrics (woven, non-woven or knitted), webbing and so on.
The practice of the invention will be illustrated with regard to cotton textiles, but it is to be understood that this is for purposes of illustration, and is not to be regarded as limiting.
The present invention is especially applicable in conjunction with the process disclosed in the aforesaid U.S. patent application Ser. No. 307,796, now U.S. Pat. No. 3,827,907, in which organic or inorganic phosphorus compounds are applied to the textile material or other substrate by impregnation and chemical modification and which phosphorus compounds contain groups such as acid or hydroxy groups, that is, groups which are capable of undergoing ion exchange either in the free acid form or the salt form such as the ammonium or alkali metal salt. Examples of useful inorganic phosphorus compounds include phosphoric acid, H 3 PO 4 , its salt such as diammonium phosphate, as well as combinations of phosphoric acid with organic bases such as urea, cyanamide or dicyandiamide. However, the cellulose or other substrate may also be reacted with a phosphorus compound such as a haloalkyl phosphonic acid derivative, e.g., chloromethylphosphonic acid, to the extent that the resulting product is capable of undergoing further reaction with titanyl sulfate.
In accordance with the present invention, the phosphorus compound is applied to the fabric in correlation with antimony oxide and a polymeric halogen-containing material such that the resulting fabric contains a reduced amount of phosphorus (as compared with a similar fabric contacted with the phosphorus compound as the only flame retardant compound) without substantially detrimentally affecting the flame retardant properties of the fabric.
Generally, the phosphorus compound is applied to the substrate by impregnation with a suitable phosphorus compound-containing solution. In accordance with the present invention, the impregnation solution can also contain antimony oxide and a polymeric halogen-containing material.
Suitable polymeric halogen-containing materials include the homopolymers and copolymers of vinyl chloride and vinylidene chloride. The commercially available polyvinyl chloride- and/or polyvinylidene chloride-containing latexes (such as the "Geon" and "Polyco" latexes available from the B. F. Goodrich Chemical Co. and Borden Chemical Co., respectively) are preferred as the polymeric halogen-containing materials.
The substrate is suitably treated to provide a total (phosphorus plus antimony plus halogen of the polymeric halogen-containing material) on the substrate of from about 0.5 to about 10, preferably from about 2 to about 6, percent by weight of the substrate. Generally, the substrate has a phosphorus content from about 0.15 to about 3, preferably from about 0.5 to about 2, percent by weight of the substrate, an antimony content of from about 0.15 to about 4, preferably from about 0.75 to about 2.5, percent by weight of the substrate, and a halogen content (from the polymeric halogen-containing material) of from about 0.15 to about 4, preferably from about 0.75 to about 2.5, percent by weight of the substrate.
The phosphorus, antimony oxide and the polymeric halogen-containing material-treated textile material is thereafter treated with a titanyl sulfate-containing solution to improve the durability of the flame retardant properties. While the aforesaid U.S. patent application Ser. No. 307,796 discloses the use of heavy metal or transition metal (i.e., those metals which fall in Groups I-B, IV-A, IV-B, V-A, V-B, VI-B, VII-B and VIII of the Periodic Chart of Elements), it has been found that titanyl sulfate is particularly advantageous with respect to durability of flame retardant properties, product color, and freedom from volatility and corrosiveness to reaction vessels of the metal salt-containing solution. As different arrangements of the Periodic Chart of the Elements are known in the art, when the terms "Periodic Chart of the Elements", "Periodic Chart" or "Periodic Table" are used in this specification, these terms shall be understood to refer to the particular arrangement which is shown at pages 56-57, Lange's Handbook of Chemistry, Ninth Edition, Handbook Publishers, Inc., Sandusky, Ohio (1956).
The titanyl sulfate can be applied to the pretreated flameproofed textile substrates from any suitable solvent which does not dissolve or otherwise undesirably attack the substrate and in which the titanyl sulfate used is soluble. Because of economic reasons and also because of its beneficial swelling effect on substrates such as cellulose, water is the preferred solvent but other solvents such as alcohols are also usable.
The quantity of titanium which is desirably applied to the phosphorus, antimony oxide and polymeric halogen-containing material-pretreated textile substrate is that which is effective in permitting enough of the titanium ions to become attached to the ion exchange sites of the flameproofing compound such that there are not sufficient ion exchange sites left unoccupied to cause a loss in fire retardance by picking up calcium during laundering. In practice, such an effective quantity of the titaniun is readily determined in each case by a limited number of preliminary, empirical screening tests.
As a more quantitative guideline it may be suggested that in a system using a phosphorus compound having two OH groups as the flameproofing agent and titanyl sulfate (i.e., TiOSO 4 .H 2 SO 4 .8H 2 O) as the heavy metal salt, the flameproofing agent will be capable of picking up about one atom of titanium per atom of phosphorus. Accordingly, in such a case it is preferred to apply the titanyl sulfate solution to the pretreated textile in a proportion producing an atomic ratio of about 1:1 for Ti to P in the treated textile. However, a satisfactory finish may generally be obtained when the Ti/P atomic ratio is in the range from 0.5:1 to 5:1, preferably from 0.75:1 to 3:1.
In applying the titanium compound to the pretreated textile substrate somewhat better metal utilization, better durability of the finish and lower strength loss of the substrate may be obtained with some systems if the phosphorus compound is in the form of an ammonium or an alkali metal salt, preferably the sodium salt, than if the phosphorus compound present on the substrate has free acid groups.
The application of the titanyl sulfate solution to the phosphorus pretreated substrate is conveniently conducted at room temperature, e.g., between 15°C. and 35°C., although higher or lower temperatures may be used.
After the titanyl sulfate is applied to the textile material containing the phosphorus flame retardant, it is allowed to react for a period of time by any suitable technique such as soaking, padding, batching, or the like and then the unreacted chemicals are washed out.
The fabrics may be washed in water with a little non-ionic wetting agent. Basic materials may be added to the wash water to neutralize acidic materials in the fabric. Examples of basic materials that can be used are soda ash, ammonium hydroxide, sodium silicate, sodium phosphate, sodium borate, etc.
Although application of the antimony oxide and polymeric halogen-containing material is preferably accomplished by simultaneous application of all materials, it will be understood that the antimony oxide and polymeric halogen-containing material can be applied to the textile material before or after application of the phosphorus compound and after treatment of the phosphorus-containing material with titanyl sulfate. Regardless, the phosphorus compound is always applied to the textile material in a reduced amount (as compared with a similar textile material contacted with the phosphorus compound as the only flame retardant compound).
The invention is broadly applicable for improving any process in which a textile material is first treated with a phosphorus-containing flameproofing agent having ion exchange capability and then treated with the titanyl sulfate to improve the durability of the flame retardant properties.
Exemplifying the types of flameproofing treatments, but not limited thereto, to which the present invention is application are the phosphonomethylation of cellulosic textile materials, such as cotton, the production of which is known and described, for example, in U.S. Pat. No. 2,979,374. The cotton fibers, and the like, are reacted with an aqueous solution of an alkali metal salt of chloromethylphosphonic acid, thereby producing a phosphonomethyl ether of cellulose. Similarly, the cellulosic textile material may be one which has been treated with an aqueous solution of cyanamide and phosphoric acid, as described, for example in U.S. Pat. No. 3,567,359, or with dicyandiamide and phosphoric acid, as described in U.S. Pat. No. 3,479,211, or with phosphoric acid and urea, as described in U.S. Pat. No. 3,253,881. All of these phosphorus-containing flameproofed textile materials are thereafter contacted with a titanyl sulfate solution as described in the aforesaid U.S. patent application Ser. No. 307,796, now U.S. Pat. No. 3,827,907 to improve the durability of the flame retardant treatment.
Regardless of the particular treatment for application of the phosphorus to the substrate, utilization of the antimony oxide and polymeric halogen-containing material in conjunction therewith as defined above permits reduction in the amount of phosphorus affixed to the substrate without substantially detrimentally affecting the flame retardant, dimensional stability or other properties of the substrate.
The invention is additionally illustrated in connection with the following Examples which are to be considered as illustrative of the present invention. It should be understood, however, that the invention is not limited to the specific details of the Examples.
EXAMPLE I
Eight-ounce cotton twill is padded with a bath of 12 percent urea, 6 percent diammonium phosphate, 10 percent Polyco 2611 (a 56 percent solids vinyl chloride copolymer latex manufactured by Borden Chemical Co.), 4 percent antimony oxide, 0.4 percent Tamol SN (a sodium salt of a condensed naphthalene sulfonic acid from Rohm & Haas) and 0.45 percent Dowfax 2A1 (a sodium dodecyl diphenylether disulfonate from Dow Chemical Co.). The Tamol SN serves as a dispersant for the antimony oxide. The Dowfax 2A1 serves as a wetting agent and a latex stabilizer. Wet pick-up (W.P.U.) is 80 percent. The fabric is dried at 250°F. for 5 minutes, cured at 350°F. for 2 minutes, washed in 0.001 percent Triton X-100, extracted, soaked in a solution containing 30 percent of a titanyl sulfate cake for 5 minutes, padded out, neutralized in 0.6 percent soda ash, rinsed and dried.
Another sample of the same eight-ounce cotton twill is padded with a bath of 28 percent urea, 14 percent diammonium phosphate and 0.1 percent Triton X-100 (an ethoxylated nonylphenyl wetting agent) to a 75 percent wet pick-up. The fabric is dried at 250°F. for 5 minutes, cured at 330°F. for 6 minutes, washed in 0.6 percent soda ash, rinsed, and then extracted to remove excess water. The extracted fabric is soaked in a solution containing 50 percent of a titanyl sulfate cake for 5 minutes, squeezed to remove excess solution, neutralized in 0.6 percent soda ash, rinsed and dried.
The flame test results according to FF 3-71, the Children's Sleepwear Standard, initially and after launderings in water of 150 ppm hardness (as calcium carbonate) and shrinkage results during processing are given in Table I.
Table I__________________________________________________________________________ Shrinkage DuringTreating Bath Processing, % inComposition, % Warp Direction Char Lengths, inches 10 25 50P.sup.1 Sb.sup.2 Cl.sup.3 Initial Washes Washes Washes__________________________________________________________________________ 6 4 5.6 5 0.4 0.4 0.5 1.414 -- -- 18 0.5 1.8 2.2 2.5__________________________________________________________________________ .sup.1 Expressed as weight percent diammonium phosphate. .sup.2 Expressed as weight percent antimony oxide. .sup.3 Expressed as weight percent polyvinyl chloride solids.
These results show that the process of the present invention provides for a substantial reduction in phosphorus content affixed to the fabric with an increase in the flame retardant properties of the fabric. Shrinkage of the fabric during processing is dramatically decreased.
EXAMPLE II
A 3.5-ounce cotton broadcloth is padded with a bath of 12 percent urea, 6 percent diammonium phosphate, 9 percent Polyco 2611, 4 percent antimony oxide, 0.4 percent Tamol SN and 0.45 percent Dowfax 2A1 to a 85 percent W.P.U. The fabric is dried at 250°F. for 5 minutes, cured at 350°F. for 2 minutes, process washed in 0.6 percent soda ash, extracted, soaked in a solution containing 50 percent of a titanyl sulfate cake for 10 minutes, neutralized in 1 percent soda ash, rinsed and dried. Shrinkage in the warp direction during processing is 2.8 percent. Flame test results are entered in Table II.
EXAMPLE III
A 3.5-ounce cotton broadcloth is treated as in Example II, except that the process wash is performed in 0.001 percent Triton X-100. Shrinkage in the warp direction during processing is 2.5 percent. Flame test results are given in Table II.
EXAMPLE IV
Four ounce cotton flannelette is padded with a bath of 12 percent urea, 6 percent diammonium phosphate, 7 percent Polyco 2611, 4 percent antimony oxide, 0.4 percent Tamol SN and 0.45 percent Dowfax 2A1 to a 100 percent W.P.U. The fabric is dried at 250°F. for five minutes, cured at 350°F. for 2 minutes, process washed in 0.6 percent soda ash, extracted, soaked in a solution containing 50 percent of a titanyl sulfate cake for ten minutes, neutralized in 10 percent soda ash, rinsed and dried. Shrinkage in the warp direction during processing is 5.8 percent. Flame test results are entered in Table II.
EXAMPLE V
Four ounce cotton flannelette is treated as in Example IV except that the process wash after the cure was done in 0.001 percent Triton X-100. Shrinkage in the warp direction during processing is 5.9 percent. Flame test results are entered in Table II. (Run 5-A)
A comparative 3.3-ounce cotton flannelette sample is padded with a bath of 26 percent Polyco 2611, 12 percent antimony oxide, 0.6 percent Tamol SN and 0.45 percent Dowfax 2A1 to a 100 percent W.P.U.; dried for 5 minutes at 250°F., cured three minutes at 330°F., and process washed at 60°C. in 0.001 percent Triton X-100. The flame test results for this comparative sample which illustrates the effect of treating the cloth with antimony oxide and polymeric halogen-containing material only are shown below in Table II. (Run 5-Comp.)
EXAMPLE VI
A 3.5-ounce cotton broadcloth is padded with a bath of 12 percent urea, 6 percent diammonium phosphate, 8 percent Polyco 2611, 3.3 percent antimony oxide, 0.36 percent Tamol SN, and 0.45 percent Dowfax 2A1 to an 85 percent W.P.U. The fabric is dried at 250°F. for 5 minutes, cured at 320°F. for 2 minutes, process washed in 0.001 percent Triton X-100, soaked in 35 percent titanyl sulfate cake for 3 minutes, neutralized in 0.6 percent soda ash, rinsed and dried. Shrinkage in the warp direction is 2.6 percent. Flame test results are entered in Table II.
Table II______________________________________Char Lengths, inches.sup.4Example Initial 10 Washes 25 Washes 50 Washes______________________________________2 1.4 -- 2.6 3.03 1.6 -- 2.9 2.94 2.3 -- 1.8 4.75-A 2.8 -- 1.4 4.45-Comp. 3.1 -- -- BEL.sup.56 2.1 1.6 2.0 2.9______________________________________ .sup.4 Determined according to FF 3-71 when laundered in water of 150 ppm hardness. .sup.5 Burned Entire Length.
EXAMPLE VII
The procedure of Example I is repeated on a number of 8-ounce cotton twill samples. Each sample is measured to determine the shrinkage (percent in warp direction) which occurs during processing and 5 launderings. In addition, unprocessed samples of the same material are also given the same launderings.
These tests are repeated on the same fabric which has been preshrunk to yield a maximum of 1 percent shrinkage during the 5 launderings.
The fabrics and shrinkage results obtained are shown below:
Shrinkage, % in Warp Direction Fabric Treating During AfterFabric Bath Composition Processing LaunderingsPre-Shrunk P.sup.1 Sb.sup.2 Cl.sup.3______________________________________No 6 4 5.6 8 0" 14 -- -- 20 0" -- -- -- 0 10Yes 6 4 5.6 -1 0" 14 -- -- 11 0" -- -- -- 0 1______________________________________ .sup.1 Expressed as weight percent diammonium phosphate. .sup.2 Expressed as weight percent antimony oxide. .sup.3 Expressed as weight percent polyvinyl chloride solids.
These results show that the process of the present invention affords the substantial decrease in shrinkage during processing both onto fabric which is pre-shrunk and fabric which is not pre-shrunk.
EXAMPLE VIII
A 3.5-ounce cotton broadcloth is padded with a bath of 12 percent urea, 5.2 percent mono-ammonium phosphate, 8 percent Polyco 2611, 4 percent antimony oxide, 0.4 percent Tamol SN and 0.45 percent Dowfax 2A1 to an 85 percent W.P.U. The fabric is dried for 5 minutes at 250°F., cured for 2 minutes at 350°F., washed in 0.001 percent Triton X-100, extracted, soaked for five minutes in a 35 percent solution of titanyl sulfate, padded out, neutralized in 0.6 percent soda ash, rinsed and dried. The treated fabric shows an average char length of 3.1 inches after fifty launderings when tested according to the Children's Sleepwear Standard (FF 3-71).
EXAMPLE IX
A 3.5-ounce cotton broadcloth is treated as in Example VIII except that in the place of 5.2 percent mono-ammonium phosphate, the pad bath contains 4.5 percent H 3 PO 4 . The treated fabric shows an average char length of 3.8 inches after fifty launderings when tested according to the Children's Sleepwear Standard.
EXAMPLE X
A 3.5-ounce cotton broadcloth is padded with a bath of 12 percent urea, 6 percent diammonium phosphate and 0.1 percent Triton X-100 to an 85 percent W.P.U. The fabric is dried 5 minutes at 250°F., cured two minutes at 350°F.
A portion (Run A) of the fabric is washed in 0.001 percent Triton X-100extracted, soaked in a 35 percent solution of titanyl sulfate for 5 minutes, neutralized in 0.6 percent soda ash, rinsed and dried. The fabric is then padded to an 80 percent W.P.U. with a bath of 8 percent Polyco 2611, 4 percent antimony oxide, 0.3 percent Tamol SN, and 0.45 percent Dowfax 2A1, dried for 5 minutes at 250°F., cured for 2 minutes at 350°F., and washed in 0.001 percent Triton X-100.
Another portion (Run B) of the urea-diammonium phosphate-containing fabric is padded with a bath of 8 percent Polyco 2611, 4 percent antimony oxide, 0.3 percent Tamol SN and 0.45 percent Dowfax 2A1 at a 75 percent W.P.U., dried five minutes at 250°F., cured 2 minutes at 350°F., and washed in 0.001 percent Triton X-100. The fabric is extracted, soaked in a solution containing 35 percent titanyl sulfate for five minutes, neutralized in 0.6 percent soda ash, rinsed and dried.
The fabric from Run A shows an average char length of 3.2 inches and the fabric from Run B shows an average char length of 2.9 inches, both after 50 launderings when tested according to the Children's Sleepwear Standard (FF 3-71). Both fabrics show moderate shrinkage (less than 10 percent in the warp direction) during processing.
The principles, preferred embodiments and modes of operation of the present invention have been described in the foregoing specification. The invention which is intended to be protected herein, however, is not to be construed as limited to the particular forms disclosed, since these are to be regarded as illustrative rather than restrictive. Variations and changes may be made by those skilled in the art without departing from the spirit of the invention. | An improvement in a process for imparting flame retardant properties to textile materials by reacting the textile materials with phosphorus-containing compounds or salts thereof and aftertreating the textile material with a salt of a heavy metal is disclosed. In the improved process, the phosphorus-containing compounds are applied in correlation with antimony oxide and a polymeric halogen-containing material. Reduced amounts of phosphorus may be affixed on the textile material (thus substantially reducing fabric shrinkage during processing) without substantially adversely affecting the flame retardant properties of the treated material. Titanyl sulfate is utilized as the heavy metal salt. In addition, the treatment is applicable to cellulosic fibers, e.g., cotton or rayon, as well as to wool, silk and other natural and man-made fibers or blends of these fibers. | 3 |
This application is a continuation of application Ser. No. 08/039,993, filed Mar. 30, 1993, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to radiography using PSL (photo-stimulable luminescence), and more particularly to cassettes used in such radiography.
2. Description of the Prior Art
In conventional radiography ("X-ray photography"), a plate is made by forming one or more silver halide emulsion layers on a flexible film base which is supported within a light-tight cassette. The interior of the cassette is coated with one or more X-ray sensitive luminescent layers. The cassette containing an unexposed X-ray film plate is loaded into an X-ray machine, and after exposure the cassette and exposed X-ray film plate are removed for development and fixing of the latent image produced. This is usually done automatically by feeding the cassette into a light-tight apparatus in which the cassette is opened, the exposed film plate is extracted and chemically processed and a new, unexposed film plate is loaded into the cassette which is then re-closed, the reloaded cassette and developed film plate being delivered to respective exit slots of the processing apparatus.
In the PSL system, a PSL X-ray plate has applied thereto a layer of a photostimulable luminescent material which comprises a phosphor, for example a europium-activated barium fluorohalide, and a binder. The phosphor has the characteristic that it can be energised to a metastable excited state by X-rays, and can then be stimulated by visible or infrared light to return to the ground state with the emission of visible light (of a different wavelength from the stimulating light). The excited state has a half-life of at least several hours or days in the absence of stimulating light. A PSL plate is potentially re-usable many times. The technique is described in an article by Sonoda et al. in Radiology, Volume 148 (September 1983), at pages 833 to 838, and it offers the potential advantages of better image resolution at lower X-ray dosages for the patient.
The phosphor is deposited as a layer on a flexible base which also requires enclosure in a light-tight cassette.
Current practice in PSL radiography is to pass the exposed PSL plate in its cassette to an automatic processing machine in which the PSL plate is removed from the cassette, scanned, exposed overall to light to return the PSL material to its ground state and then reloaded into a cassette for reuse. For scanning, the exposed PSL plate is transported past a laser, typically a helium-neon laser emitting at a wavelength of 633 nm, which scans line-wise across the plate in front of a light-guide comprising a bundle of optical fibers whose input ends are arranged in a line across the path of the plate close to the laser scanning line for the reception of light emitted, typically at wavelengths close to 400 nm, when the PSL material is stimulated by the laser. The light-guide is arranged to pass the emitted light to a photo-multiplier tube or other receptor. The result is a storable electronic raster image. The electronic image may be subjected to any desired computer image-enhancement techniques and it may be displayed on a video display unit, fed to a laser printer for the production of a plain paper copy, or used to control a laser arranged to expose a photographic film plate to produce an X-ray plate of conventional appearance.
The cassettes used in PSL radiography must have external dimensions which, are compatible with those of conventional X-ray photography cassettes so that the PSL cassettes can be exposed in the cassette holder of a conventional X-ray machine. This is not, of course, to imply that all radiography cassettes are of the same format: they are not, they vary in format from about A5 paper size suitable for wrist X-rays to about A2 for chest X-rays and even larger. In fact, the practice has developed of depositing the phosphor layer on a conventional X-ray film base and of exposing it in a conventional X-ray photography cassette which is modified only in that it does not contain any X-ray sensitive luminescent layer.
Thus currently used PSL cassettes have not been designed with the specific purpose of PSL radiography in mind, and they suffer from a number of disadvantages which will be explained later in this specification.
DESCRIPTION OF THE INVENTION
OBJECT OF THE INVENTION
It is an object of this invention to provide a PSL cassette in which at least some of the disadvantages of currently used PSL cassettes are alleviated or avoided.
SUMMARY OF THE INVENTION
According to this invention, there is provided a cassette for photo-stimulable luminescence ("PSL") radiography, characterised in that such cassette comprises a flat rigid base plate and a cap or cover for the base plate which is releasably securable to the base plate so as to cover in light-tight fashion a layer of PSL material applied to the inside of the base plate.
A PSL cassette according to the invention offers a number of very important advantages over the use of a conventional PSL cassette which contains a separate flexible PSL plate. The flexible plate of a conventional PSL cassette will inevitably in use undergo flexure. As a result the layer of PSL material will be stressed. This will inevitably lead to breakdown of the PSL material.
In a conventional PSL cassette, it is possible to prolong the life of the PSL material by a suitable choice of binder for the phosphor and by increasing the proportion of binder in the PSL material. But if the proportion of binder is increased, the proportion of phosphor will be reduced so resolution will also be reduced. It might be possible to make some gain in resolution by making the PSL material thicker, but it will be appreciated that increasing the thickness of a PSL layer will lead to an increase in scattering which is a further cause of loss of resolution. These problems do not arise in a PSL cassette according to the invention. Because the PSL material is held on a flat and substantially rigid plate it will not be stressed by flexure. It will therefore have a longer useful service life. Also, and at least as importantly, because the layer of PSL material is not stressed in that way, it can be made thinner, and with a higher proportion of phosphor to binder, without any substantial deleterious effect on its service life, thus leading to a significant potential increase in resolution.
A PSL cassette according to the invention offers further advantages. Because a conventional PSL plate is flexible, it must be held flat after removal from its cassette for transport through a scanner and this may imply a need for both faces of such a plate to be contacted, for example, by transport rollers, by this or any other contact with the coated face of the plate will involve a risk that the PSL layer will become scratched. This disadvantage too is alleviated by the adoption of this invention. Because the PSL plate of the cassette of the invention is flat and rigid, it can readily be transported through a scanner without any contact between parts of the scanner transport system and the PSL layer. Such transport could for example be effected by rollers bearing on the edge faces of the plate. A further advantage of using a flat and rigid PSL plate is that the light-guide of the scanner apparatus can be located closer to the path of the plate while still giving a reliable clearance for the passage of the plate without any contact between the plate and the light-guide. A small, but nevertheless reliable, clearance between the plate and the light-guide promotes the efficiency and resolution with which light emitted by the PSL material is collected.
A cassette in which the PSL material is directly applied to one part of a cassette, whereby disadvantages inherent to the use of a separate flexible plate are avoided, is disclosed in EP A1 0 347 647. A cassette in accordance with this disclosure has the disadvantage that the PSL material is fitted to a flexible support whereby it is liable to stresses as hereinbefore described.
Preferably, the cap of the inventive cassette is formed with a peripheral flange which surrounds and substantially conforms to edge faces of the base plate. This helps to promote light-tightness of the cassette when the cap is on the base plate.
In the most preferred embodiments of the invention, the edge faces of the base plate at least partially slope inwardly towards the face bearing the layer of PSL material. The edge faces of the base plate may thus be partially rounded or bevelled. Such bevelling of the edge faces of the base may be relatively slight, so that they make an angle of about 100° to the coated surface instead of 90 if they were perpendicular thereto. The purpose of this rounding or bevelling is to facilitate the reunion or re-assembly of the cap and base plate altar they have been separated and the PSL coating on the base has been scanned and erased (by exposure to flooding light, e.g. from fluorescent tubes). If there is a slight misalignment of the cap and the base plate, this will be automatically corrected as the top surface of the base enters the open interior of the cap and one or other edge of the base contacts the corresponding side of the cap, with a self-centering effect. This allows the tolerances of the transport mechanisms in the scanner to be less stringent. Advantageously, the edge faces of the base plate are substantially flat. For a given angle of bevel, this increases permissible tolerances which will still allow self-centering, and it is also very simple to form the base in this way.
Preferably, edge faces of the base plate are coated with opaque flock. This helps to promote light-tightness of the cassette.
The base plate may be manufactured from any suitable material, but it is advantageously of sandwich construction comprising a pair of sheets with a cellular layer bonded between them. Such materials are already available commercially and are inexpensive. They combine low mass with a high degree of flatness and rigidity, and they are easy to machine to size and shape. The central cellular layer may for example be of a rigid polyurethane foam material while the pair of sandwiching sheets are of glass fiber reinforced plastics material. Base plates for a PSL cassette in accordance with this invention may easily be cut to size from sheets of such material. The foam layer which might otherwise be exposed at the edge faces of such base plates may be covered in flock as aforesaid, for the dual purposes of promoting light-tightness and affording a neat appearance to those edge faces.
Preferably, the cap is made of black plastic material such as polyethylene or polyvinyl chloride. Such materials are light-tight, and easily mouldable to form caps for PSL cassettes in accordance with this invention while also being tough and hard-wearing so that they can protect the layer of PSL material, without being so hard that there is a serious risk of damage to the layer of PSL material caused by pressing the cap and base plate together.
In some preferred embodiments of the invention, the top wall of the cap is lined on its exterior face with a cushion. The provision of such a cushion, which suitably comprises a layer of soft foam material faced with a thin soft plastics film, is of further assistance in avoiding damage to the PSL material, and is especially suitable for use in portable X-ray machines and in other instances where a patient may be required to lie directly on top of the cassette.
In a cassette according to the present invention, the base plate may have a peripheral heel protruding from the bottom end of the base plate in a plane parallel to that of the bottom face of the plate. Suitably, such heel protrudes over a distance such that its outer edge coincides generally with the lower edge of the peripheral flange of the cap.
Advantageously, the base plate carries a programmable erasable memory chip. Various kinds of data may be entered on such a memory chip, for example patient identification data such as name and date of birth, and data relating to the exposure used and/or to any signal processing. The use of such a memory chip, for example a so-called electrically erasable programmable read only memory (EEPROM) and its advantages are known from conventional radiography (X-ray photography), but in that case, and also in the case of previously known PSL cassettes, the memory chip has had to be incorporated in the cassette which is separable from the X-ray sensitive image recording material. The separation of the cassette cover bearing such data from the X-ray plate which takes place during processing of such known cassettes inevitably gives rise to the possibility that data relating to one patient may become associated with the X-ray plate of another patient. Incorporating the memory chip in the base plate of a cassette according to such preferred embodiments of the present invention has the further advantage that the memory chip is at no stage in the processing detached from the X-ray sensitive layer thus avoiding the possibility of confusing data in that way.
BRIEF DESCRIPTION OF THE DRAWINGS
A PSL cassette embodying the present invention will now be described, by way of example, with reference to the drawings, in which:
FIG. 1 is a sectional view of the base plate and cap or cover in engagement, i.e. in assembled relationship,
FIG. 2 is a sectional view of the base plate and cap disengaged, and
FIG. 3 is an enlarged view of a modification of a detail section designated 3 in FIG. 2.
DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION
Referring to the drawings, the cassette consists of a base plate 10 and a cap or cover 20. The base plate 10 has a coating 11 of PSL material on its upper surface and its edge faces have a slight bevel indicated at 12. The cap 20 has a top plate 21 with a peripheral flange forming sides 22 projecting downwards from the top plate so as to fit the base 10 closely, the sides 22 having a bevel conforming to that of the edge faces of the base 10.
Latching mechanisms are located at suitable points around the edge faces of the base and cap, e.g. towards the ends of a pair of opposite edge faces. Each latching mechanism comprises a captive pin 13 and spring 14 located in a hole 15 in the edge of the base, and a matching hole 23 in the side of the cap. The pin 13 projects beyond the edge of the base by only a small distance and itself has a bevelled end, so that when the cap 20 is pressed down onto the base, the pin 13 is pressed in until the hole 23 of the cap is opposite the pin, whereupon the pin springs out again into the hole to hold the cap on the base.
The edge faces 28 of the base 10 and/or the inside surfaces of the sides 22 of the cap 20 are coated with black flock material 16 to assist in preventing light from reaching the PSL layer 11 when the base and cap are engaged. (Such light would tend to discharge the energisation of the PSL material and so degrade the stored image.) The flock material can conveniently be applied by electrostatic spraying.
The base plate 10 carries a programmable erasable memory chip 17, for example a so-called electrically erasable programmable read only memory (EEPROM). Various kinds of data may be entered on such a memory chip, for example patient identification data, such as name and date of birth, data relating to the exposure used and/or to any signal processing, and an indication of the number of times the PSL material carried by that base plate 10 has been exposed in an X-ray machine.
The cap 20 may have a ridge (not shown) formed around the border of its inside top surface, adjacent to the sides 22, to provide a slight spacing between that inside top surface and the PSL coating on the base 10. However, this inside surface of the top plate 21 is preferably lined with a cushion 25 which suitably comprises a layer of soft foam material faced with a thin soft plastics film. These measures will help to minimize wear and abrasion of the PSL layer 11.
The cap 20 is readily disengageable from the base plate 10 by pressing in the spring-loaded pins 13.
A scanner machine for scanning the present PSL cassette is described in our European application No. 92 201 110.1, entitled "Scanner for PSL radiographic cassettes", filed on Apr. 4, 1992.
FIG. 3 shows an improved feature of the described cassette. This figure is an enlargement of detail section 3 of FIG. 2 (the locking mechanism being omitted). The base plate 10 is provided with a peripheral heel or shoulder 26 protruding from the base and extending outwardly, its outer edge 29 coinciding practically with the outer edge 27 of the peripheral flange of the cap 21. This feature has the advantage that if the cassette is taken up by the operator from a desk or the like the operator's fingers do not pull on the lower edge of the cap but instead on the peripheral rim of the base plate. The described feature is particularly important if a plurality of cassettes are stacked onto each other, the increased mass causing an excessive loading and occasional distorsion of the slanting sides of the lowest cassette if engaged to lift the stack.
The base plate 10 and the cap may be releasably secured together in other ways than by means of the described locking pins 13 and holes 23.
For instance, patches of a fastener of the burr-and-nap type such as that widely sold under the Trade Mark Velcro may be applied respectively to the base and cap.
Alternatively, co-operating patches comprising a plurality of inter-engaging elements of a nail-like shape may be used. Such like patches are sold under the Trade Mark Dual Lock, manufactured by 3M. | A cassette for a photo-stimulable luminescence (PSL) radiography which comprises a flat rigid base having one surface of which a layer of PSL material is adapted to be supported, a cover for the flat base constituted of a top wall coextensive in area with the one surface of the flat base and a flange extending around the periphery of the cover top wall and projecting at an angle to the cover top wall, the peripheral flange of the wall being disposed in close-fitting relation to side edges of the base when the base and cover are assembled, and cooperating releasable detent means on the peripheral flange of the cover and the side edges of the base for securing the cover and base together, the cover being separable from the base upon release of the detent means to permit the base for radiographic exposure of the PSL layer. Preferably, the rigid base has significant thickness so that its side edges are in the form of side faces and the base side faces are inclined laterally with the side walls of the cover being correspondingly inclined in order to facilitate assembly of the cover on the base. | 6 |
BRIEF DESCRIPTION OF THE DRAWINGS
[0001] FIG. 1A is a perspective view of an embodiment of a downforce controller.
[0002] FIG. 1B is a side elevation view of the embodiment of the downforce controller of FIG. 1A .
[0003] FIG. 1C is a cross-sectional view of the downforce controller of FIG. 1A .
[0004] FIG. 2A is a side elevation view of an embodiment of a planter row unit incorporating the downforce controller of FIG. 1A .
[0005] FIG. 2B is a side elevation view of an embodiment of a planter and a tractor drawing the planter row unit of FIG. 2A through a field.
[0006] FIG. 3 schematically illustrates an embodiment of an electronic control system for controlling one or more downforce controllers.
[0007] FIG. 4 is a top view of an embodiment of a fluid control system for controlling multiple downforce controllers.
[0008] FIG. 5 is a cross-sectional view of another embodiment of a downforce controller including a lift pressure control valve.
[0009] FIG. 6 is a top view of another embodiment of a fluid control system for controlling multiple downforce controllers.
[0010] FIG. 7 is a fluid schematic illustrating an embodiment of a manifold for controlling pressure delivered to a downforce controller.
DESCRIPTION
Downforce Controller
[0011] Referring now to the drawing figures, wherein like reference numerals designate identical or corresponding parts throughout the several views, FIGS. 1A-1C illustrate an embodiment of a downforce controller 100 . Referring to FIG. 1A , the downforce controller 100 includes a manifold 110 and a cylinder 130 . The manifold 110 preferably includes a manifold body 102 , a lift control conduit 120 , and a cavity (not shown) sized to receive a down pressure control valve 140 . The manifold body 102 preferably includes a supply passage 112 , a return passage 114 , and a lift control passage 116 . Each passage 112 , 114 , 116 preferably includes a left fitting, a right fitting, and an aperture connecting the left and right fittings. Referring to the cross-sectional view of FIG. 1C , the manifold body 110 preferably includes a control pressure diagnostic passage 118 and a down chamber connection passage 111 .
[0012] The cylinder 130 includes a barrel 132 , a rod 170 , and a gland 138 . The cylinder 130 is mounted to the manifold 110 . In the embodiment illustrated in FIGS. 1A-1C , the barrel 132 is mounted to the manifold body 102 . Referring to the cross-sectional view of FIG. 1C , the gland 138 is mounted to a lower end of the barrel 132 and the rod 170 is slidably mounted within the gland 138 . The rod 170 includes a piston 174 which separates an interior volume of the barrel 132 into a down chamber 136 and a lift chamber 134 .
[0013] The down pressure control valve 140 is preferably a electro-hydraulic pressure reducing-relieving valve. The down pressure control valve 140 preferably includes a solenoid 142 having an electrical port 144 . The down pressure control valve 140 preferably includes a flow control valve 150 having a supply port 152 , a return port 154 , and a control port 158 ( FIG. 1C ). The pressure control valve 140 is preferably a PDR08-P proportional pressure relief valve available from Hydac International GmbH in Sulzbach, Germany (“Hydac”). The down pressure control valve 140 is preferably mounted to the manifold body 102 . The down pressure control valve 140 is preferably oriented substantially parallel with the cylinder 130 .
[0014] Referring to FIG. 1C , the supply port 152 of the pressure control valve 140 is in fluid communication with the supply passage 112 . The return port 154 is in fluid communication with the return passage 114 . The control port 158 is in fluid communication with the control pressure diagnostic passage 118 . The control pressure diagnostic passage 118 is in fluid communication with the down chamber connection passage 111 . The down chamber connection passage 111 is in fluid communication with the down chamber 136 . The control pressure diagnostic passage 118 and the down chamber connection passage 111 collectively comprise a passage placing the control port 158 in fluid communication with the down chamber 136 . The conduit 120 places the lift control passage 116 in fluid communication with the lift chamber 134 . The control pressure diagnostic passage 118 is preferably capped with a cap 119 which may be removed in order to place a gauge, transducer, or other pressure measurement device in fluid communication with the control port 158 .
[0015] In operation, the flow control valve 150 establishes a control pressure at the control port 158 by selectively allowing flow between the control port 158 , the supply port 152 , and the return port 154 as is known in the art. The solenoid 142 changes an operating state of the down pressure control valve 140 (e.g., by imposing a force on a component of the flow control valve 150 ) to modify the control pressure as is known in the art. The control pressure set by the solenoid 142 preferably corresponds to a signal received at the electrical port 144 .
Implement Installation and Operation
[0016] Turning to FIGS. 2A and 2B , an embodiment of the downforce controller 100 is illustrated installed on a planter 10 drawn by a tractor 5 . The planter 10 includes a transversely extending toolbar 14 to which multiple row units 200 are mounted in transversely spaced relation.
[0017] For attachment purposes, the manifold body 102 of the downforce controller 100 includes a pin eye 182 ( FIGS. 1A-1C ) and the rod 170 includes a clevis 172 . Referring to FIG. 2A , a controller attachment bracket 214 is mounted to the front bracket 212 . The downforce controller 100 is pivotally connected to the controller attachment bracket 214 by an upper pin 215 - 1 extending through the pin eye 182 . The downforce controller 100 is pivotally connected at a lower end to a parallel linkage 216 by a lower pin 215 - 2 extending through the clevis 172 . A manifold 700 is preferably mounted to the toolbar 14 .
[0018] Continuing to refer to FIG. 2A , the parallel linkage 216 supports the row unit 200 from the toolbar 14 , permitting each row unit to move vertically independently of the toolbar and the other spaced row units in order to accommodate changes in terrain or upon the row unit encountering a rock or other obstruction as the planter is drawn through the field. A ride quality sensor 364 , preferably an accelerometer, is mounted to the row unit 200 and disposed to measure the vertical velocity and acceleration of the row unit 200 . Each row unit 200 further includes a mounting bracket 220 to which is mounted a hopper support beam 222 and a subframe 224 . The hopper support beam 222 supports a seed hopper 226 and a fertilizer hopper 228 as well as operably supporting a seed meter 230 and a seed tube 232 . The subframe 224 operably supports a furrow opening assembly 234 and a furrow closing assembly 236 .
[0019] In operation of the row unit 200 , the furrow opening assembly 234 cuts a furrow 38 into the soil surface 40 as the planter 10 is drawn through the field. The seed hopper 226 , which holds the seeds to be planted, communicates a constant supply of seeds 42 to the seed meter 230 . The seed meter 230 of each row unit 200 is preferably selectively engaged to a drive 372 via a clutch 370 such that individual seeds 42 are metered and discharged into the seed tube 232 at regularly spaced intervals based on the seed population desired and the speed at which the planter is drawn through the field. The drive 372 and clutch 370 may be of the types disclosed in U.S. patent application Ser. No. 12/228,075, incorporated herein in its entirety by reference. A seed sensor 360 , preferably an optical sensor, is supported by the seed tube 232 and disposed to detect the presence of seeds 42 as they pass. The seed 42 drops from the end of the seed tube 232 into the furrow 38 and the seeds 42 are covered with soil by the closing wheel assembly 236 .
[0020] The furrow opening assembly 234 preferably includes a pair of furrow opening disk blades 244 and a pair of gauge wheels 248 selectively vertically adjustable relative to the disk blades 244 by a depth adjusting mechanism 268 . The depth adjusting mechanism 268 preferably pivots about a downforce sensor 362 , which preferably comprises a pin instrumented with strain gauges for measuring the force exerted on the gauge wheels 248 by the soil 40 . The downforce sensor 362 is preferably of the type disclosed in Applicant's co-pending U.S. patent application Ser. No. 12/522,253, incorporated herein in its entirety by reference. In other embodiments, the downforce sensor is of the types disclosed in U.S. Pat. No. 6,389,999, incorporated herein in its entirety by reference. The disk blades 244 are rotatably supported on a shank 254 depending from the subframe 224 . Gauge wheel arms 260 pivotally support the gauge wheels 248 from the subframe 224 . The gauge wheels 248 are rotatably mounted to the forwardly extending gauge wheel arms 260 .
[0021] Referring to FIG. 2B , a GPS receiver 366 is preferably mounted to an upper portion of the tractor 5 . A monitor 310 is preferably mounted in a cab 7 of the tractor 5 . One or more speed sensors 368 , such as a Hall-effect wheel speed sensor or a radar speed sensor, are preferably mounted to the tractor 5 .
Electrical Control System
[0022] Turning to FIG. 3 , an electrical control system 300 for controlling and measuring downforce and other implement functions is illustrated schematically. In the electrical control system, the monitor 310 is preferably in electrical communication with the down pressure control valves 140 and a lift pressure control valve 740 (described herein with respect to FIG. 7 ), as well as the drives 370 and the clutches 372 . The monitor 310 is preferably in electrical communication with the downforce sensors 362 as well as the seed sensors 360 , the downforce sensors 362 , the speed sensors 368 , and the GPS receiver 366 .
[0023] The monitor 310 preferably includes a central processing unit (“CPU”) 316 , a memory 314 , and a graphical user interface (“GUI”) 312 allowing the user to view and enter data into the monitor. The monitor 310 is preferably of the type disclosed in Applicant's co-pending U.S. patent application Ser. No. 13/292,384, the disclosure of which is hereby incorporated herein in its entirety by reference, such that the monitor is capable of displaying downforce and seeding information to the user.
Downforce Fluid Control System
[0024] Turning to FIG. 4 , an embodiment of a fluid control system 400 is illustrated installed on four downforce controllers 100 (each installed on a respective row unit 200 ), the toolbar 14 and the tractor 5 . The fluid control system includes a supply 430 , preferably a power-beyond supply port located on the tractor 5 , and a tank 440 , preferably a power-beyond tank port (not shown) located on the tractor 5 . The supply 430 and tank 440 are in fluid communication with the manifold 700 .
[0025] Turning to FIG. 7 , an embodiment of the manifold 700 is illustrated schematically. The manifold 700 includes a filter 710 (preferably model no. CP-SAE-120 available from Hydac), a check valve 720 (preferably model no. RV 16A-01 available from Hydac), and the lift pressure control valve 740 (preferably an equivalent valve to the down pressure control valve 140 ). The supply 430 is in fluid communication with the filter 710 , a pressure port of the lift pressure control valve 740 , and a supply hose 422 connected to a supply port of the manifold 700 . The tank 440 is in fluid communication with the check valve 720 , a tank port of the lift pressure control valve 740 , and a return hose 424 connected to a return port of the manifold 700 . A control port of the lift pressure control valve 740 is preferably in fluid communication with a lift control hose 426 connected to a lift control port of the manifold 700 .
[0026] Returning to FIG. 4 , the supply hose 422 is in fluid communication with the supply passage 112 of the first downforce controller 100 - 1 . The supply passage 112 of each downforce controller 100 is in fluid communication with the supply passage 112 of an adjacent downforce controller 100 via an inter-row supply hose 412 . The distal port of the supply passage 112 of the distal downforce controller (e.g., the right-hand port of the supply passage of the downforce controller 100 - 4 as illustrated in FIG. 4 ) is preferably capped with a cap 450 .
[0027] The return hose 424 is in fluid communication with the return passage 114 of the first downforce controller 100 - 1 . The return passage 114 of each downforce controller 100 is in fluid communication with the return passage 114 of an adjacent downforce controller 100 via an inter-row return hose 414 . The distal port of the return passage 114 of the distal downforce controller (e.g., the right-hand port of the return passage of the downforce controller 100 - 4 as illustrated in FIG. 4 ) is preferably capped with a cap 450 .
[0028] The lift control hose 426 is in fluid communication with the lift control passage 116 of the first downforce controller 100 - 1 . The lift control passage 116 of each downforce controller 100 is in fluid communication with the lift control passage 116 of an adjacent downforce controller 100 via an inter-row lift hose 416 . The distal port of the lift control passage 116 of the distal downforce controller (e.g., the right-hand port of the lift control passage of the downforce controller 100 - 4 as illustrated in FIG. 4 ) is preferably capped with a cap 450 .
Operation
[0029] In operation of the fluid control system 400 and the electronic control system 300 , the monitor 310 preferably receives a downforce signal from each downforce sensor 362 . The monitor 310 preferably uses the downforce signal to display the downforce measured at each row unit 200 . The monitor 310 preferably uses the downforce signal to select a target net downforce to be applied to each row unit 200 by each downforce controller 100 . For example, if the downforce signal for a given row unit 200 is in excess of a threshold, the monitor 310 preferably reduces the target net downforce to be applied by the corresponding controller 100 . In other embodiments, the monitor 310 allows the user to simply select a target net downforce for each downforce controller 100 . Once the target net downforce is selected for each downforce controller, the monitor 310 preferably sends control signals to each down pressure control valve 140 and the lift pressure control valve 740 such that the net downforce applied by each downforce controller 100 more closely approximates the corresponding target net downforce. In some embodiments, the monitor 310 selects desired control pressures according to the methods disclosed in Applicant's co-pending U.S. patent application No. 61/515,700, incorporated herein in its entirety by reference.
Downforce Controller—Alternative Embodiments
[0030] Turning to FIG. 5 , an alternative embodiment of a downforce controller 500 is illustrated in cross-section. The downforce controller 500 includes a manifold 510 and a conduit 520 , allowing incorporation of an individual lift control valve 140 - 1 to control the pressure in the lift chamber 134 . The individual lift pressure control valve 140 - 1 is preferably substantially similar to the pressure control valve 140 . It should be appreciated that the right hand side of the manifold 510 is similar to the manifold 110 except that the lift control passage 116 is preferably omitted.
[0031] The manifold 510 preferably includes a manifold body 502 , a lift control conduit 520 , and a cavity sized to receive the individual lift pressure control valve 140 - 1 . The manifold body 502 preferably includes a supply passage 512 and a return passage 514 . Each passage 512 , 514 preferably includes a left fitting, a right fitting, and an aperture connecting the left and right fittings. The manifold body 510 preferably includes a control pressure diagnostic passage 518 and a down chamber connection passage 511 .
[0032] The supply port of the individual lift pressure control valve 140 - 1 is in fluid communication with the supply passage 512 . The return port of the individual lift pressure control valve 140 - 1 is in fluid communication with the return passage 514 . The control port of the individual lift pressure control valve 140 - 1 is in fluid communication with the control pressure diagnostic passage 518 . The control pressure diagnostic passage 518 is in fluid communication with the down chamber connection passage 511 . The down chamber connection passage 511 is in fluid communication with the down chamber 136 . The control pressure diagnostic passage 518 and the down chamber connection passage 511 collectively comprise a passage placing the control port of the individual lift pressure control valve 140 - 1 in fluid communication with the down chamber 136 . The conduit 520 places the lift control passage 516 in fluid communication with the lift chamber 134 . The control pressure diagnostic passage 518 is preferably capped with a cap (not shown) which may be removed in order to place a gauge or other pressure measurement device in fluid communication with the control port of the individual lift pressure control valve 140 - 1 .
[0033] Turning to FIG. 6 , a modified fluid control system 600 is illustrated installed on four downforce controllers 500 (each installed on a respective row unit 200 ), the toolbar 14 and the tractor 5 . The fluid control system 600 preferably includes the same supply 430 and tank 440 as the fluid control system 500 .
[0034] The supply passage 112 and return passage 114 of the first downforce controller 500 - 1 are in fluid communication with the supply 430 and the tank 440 , respectively. As with the fluid control system 500 , the supply passage 112 and the return passage 114 of each downforce controller 500 are in fluid communication with the supply passage 112 and the return passage 114 , respectively, of an adjacent downforce controller 500 via the supply hose 412 and the return hose 414 , respectively.
[0035] Similarly, the supply passage 512 and return passage 514 of the rightmost downforce controller 500 - 4 are in fluid communication with the supply 430 and the tank 440 , respectively. The supply passage 512 and the return passage 514 of each downforce controller 500 are in fluid communication with the supply passage 512 and the return passage 514 , respectively, of an adjacent downforce controller 500 via an inter-row supply hose 612 and an inter-row return hose 614 , respectively.
[0036] The individual lift control valve 140 - 1 is preferably in electrical communication with the monitor 130 . In operation of the modified fluid control system 600 , the monitor 130 is preferably configured to select pressures of both the lift pressure control valve 140 - 1 and the down pressure control valve 140 - 1 . The monitor 130 is preferably configured to alter the commanded lift pressure and down pressure for each downforce controller 500 based on the downforce signal received from the downforce sensor 362 of the corresponding row unit 200 .
[0037] In other embodiments of the downforce controller 500 , the down chamber connection passage 511 is in fluid communication with the control port of the lift pressure control valve 140 - 1 via a pilot-operated blocking valve whose pilot pressure port is in fluid communication with the control port of the down pressure control valve 140 - 1 such that lift pressure is only applied when the down pressure exceeds a threshold. Similarly, in other embodiments of the downforce controller 100 , the lift control passage 116 is in fluid communication with the conduit 120 via a pilot-operated blocking valve whose pilot pressure port is in fluid communication with the control port of the down pressure control valve 140 such that lift pressure is only applied when the down pressure exceeds a threshold. In such embodiments, the pilot-operated blocking valve is preferably housed within the manifold body.
[0038] In other embodiments of the downforce controller 100 and the downforce controller 500 , the down pressure control valve 140 and/or the lift pressure control valve 740 and/or the individual lift pressure control valve 140 - 1 are replaced with a manually operated pressure reducing-relieving valves such that the user may manually select the lift and/or down pressure applied to each row unit 200 .
[0039] In still other embodiments of the downforce controller 100 , a spring is incorporated in the lift chamber 134 such that the spring is compressed as the rod 170 extends. A bottom of the spring is preferably adjustable from outside the cylinder (e.g., by a lockable sliding mechanism supporting an annular ring on which the spring rests) such that the user is enabled to adjust the compression and reaction force of the spring as the rod extends. In such embodiments, the conduit 120 and lift control passage 116 are preferably omitted.
[0040] The foregoing description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiment of the apparatus, and the general principles and features of the system and methods described herein will be readily apparent to those of skill in the art. Thus, the present invention is not to be limited to the embodiments of the apparatus, system and methods described above and illustrated in the drawing figures, but is to be accorded the widest scope consistent with the spirit and scope of the appended claim. | A downforce controller for an agricultural implement having a double-acting hydraulic cylinder. The cylinder is configured to be coupled to an agricultural row unit and an agricultural toolbar for transmitting a net downforce between the agricultural toolbar and the agricultural row unit. A first pressure in a first chamber of the cylinder and a second pressure in a second chamber of the cylinder have counteracting effects on the net downforce. A manifold coupled to the cylinder is in fluid communication with the first chamber. A pressure control valve coupled to the manifold is in fluid communication with the manifold and the first chamber. | 5 |
This application is a continuation-in-part of U.S. Ser. No. 748,544 filed Aug. 22, 1991, now U.S. Pat. No. 5,327,518, entitled "AUDIO ANALYSIS/SYNTHESIS SYSTEM."
TECHNICAL FIELD
The present invention relates to methods and apparatus for acoustic signal processing and especially for audio analysis and synthesis. More particularly, the present invention relates to the analysis and synthesis of audio signals such as speech or music, whereby time-, frequency- and pitch-scale modifications may be introduced without perceptible distortion.
BACKGROUND OF THE INVENTION
For many years the most popular approach to representing speech signals parametrically has been linear predictive (LP) modeling. Linear prediction is described by J. Makhoul, "Linear Prediction: A Tutorial Review," Proc. IEEE, vol. 63, pp. 561-580, April 1975. In this approach, the speech production process is modeled as a linear time-varying, all-pole vocal tract filter driven by an excitation signal representing characteristics of the glottal waveform. While many variations on this basic model have been widely used in low bit-rate speech coding, the formulation known as pitch-excited LPC has been very popular for speech synthesis and modification as well. In pitch-excited LPC, the excitation signal is modeled either as a periodic pulse train for voiced speech or as white noise for unvoiced speech. By effectively separating and parameterizing the voicing state, pitch frequency and articulation rate of speech, pitch-excited LPC can flexibly modify analyzed speech as well as produce artificial speech given linguistic production rules (referred to as synthesis-by-rule).
However, pitch-excited LPC is inherently constrained and suffers from well-known distortion characteristics. LP modeling is based on the assumption that the vocal tract may be modeled as an all-pole filter; deviations of an actual vocal tract from this ideal thus result in an excitation signal without the purely pulse-like or noisy structure assumed in the excitation model. Pitch-excited LPC therefore produces synthetic speech with noticeable and objectionable distortions. Also, LP modeling assumes a priori that a given signal is the output of a time-varying filter driven by an easily represented excitation signal, which limits its usefulness to those signals (such as speech) which are reasonably well represented by this structure. Furthermore, pitch-excited LPC typically requires a "voiced/unvoiced" classification and a pitch estimate for voiced speech; serious distortions result from errors in either procedure. Time-frequency representations of speech combine the observations that much speech information resides in the frequency domain and that speech production is an inherently non-stationary process. While many different types of time-frequency representations exist, to date the most popular for the purpose of speech processing has been the short-time Fourier transform (STFT). One formulation of the STFT, discussed in the article by J. L. Flanagan and R. M. Golden, "Phase Vocoder," Bell Sys. Tech. J., vol. 45, pp. 1493-1509, 1966, and known as the digital phase vocoder (DPV), parameterizes speech production information in a manner very similar to LP modeling and is capable of performing speech modifications without the constraints of pitch-excited LPC.
Unfortunately, the DPV is also computationally intensive, limiting its usefulness in real-time applications. An alternate approach to the problem of speech modification using the STFT is based on the discrete short-time Fourier transform (DSTFT), implemented using a Fast Fourier Transform (FFT) algorithm. This approach is described in the Ph.D. thesis of M. R. Portnoff, Time-Scale Modification of Speech Based on Short-Time Fourier Analysis, Massachusetts Institute of Technology, 1978. While this approach is computationally efficient and provides much of the functionality of the DPV, when applied to modifications the DSTFT generates reverberant artifacts due to phase distortion. An iterative approach to phase estimation in the modified transform has been disclosed by D. W. Griffin and J. S. Lim in "Signal Estimation from Modified Short-Time Fourier Transform," IEEE Trans. On Acoust., Speech and Signal Processing, vol. ASSP-32, no. 2, pp. 236-242, 1984. This estimation technique reduces phase distortion, but adds greatly to the computation required for implementation.
Sinusoidal modeling, which represents signals as sums of arbitrary amplitude- and frequency-modulated sinusoids, has recently been introduced as a high-quality alternative to LP modeling and the STFT and offers advantages over these approaches for synthesis and modification problems. As with the STFT, sinusoidal modeling operates without an "all-pole" constraint, resulting in more natural sounding synthetic and modified speech. Also, sinusoidal modeling does not require the restrictive "source/filter" structure of LP modeling; sinusoidal models are thus capable of representing signals from a variety of sources, including speech from multiple speakers, music signals, speech in musical backgrounds, and certain biological and biomedical signals. In addition, sinusoidal models offer greater access to and control over speech production parameters than the STFT.
The most notable and widely used formulation of sinusoidal modeling is the Sine-Wave System introduced by McAulay and Quatieri, as described in their articles "Speech Analysis/Synthesis Based on a Sinusoidal Representation," IEEE Trans. on Acoust., Speech and Signal Processing, vol. ASSP-34, pp. 744-754, August 1986, and "Speech Transformations Based on a Sinusoidal Representation," IEEE Trans. on Acoust., Speech and Signal Processing, vol. ASSP-34, pp. 1449-1464, December 1986. The Sine-Wave System has proven to be useful in a wide range of speech processing applications, and the analysis and synthesis techniques used in the system are well-justified and reasonable, given certain assumptions.
Analysis in the Sine-Wave System derives model parameters from peaks of the spectrum of a windowed signal segment. The theoretical justification for this analysis technique is based on an analogy to least-squares approximation of the segment by constant-amplitude, constant-frequency sinusoids. However, sinusoids of this form are not used to represent the analyzed signal; instead, synthesis is implemented with parameter tracks created by matching sinusoids from one frame to the next and interpolating the matched parameters using polynomial functions.
This implementation, while making possible many of the applications of the system, represents an uncontrolled departure from the theoretical basis of the analysis technique. This can lead to distortions, particularly during non-stationary portions of a signal. Furthermore, the matching and interpolation algorithms add to the computational overhead of the system, and the continuously variable nature of the parameter tracks necessitates direct evaluation of the sinusoidal components at each sample point, a significant computational obstacle. A more computationally efficient synthesis algorithm for the Sine-Wave System has been proposed by McAulay and Quatieri in "Computationally Efficient Sine-Wave Synthesis and its Application to Sinusoidal Transform Coding," Proc. IEEE Int'l Conf. on Acoust., Speech and Signal Processing, pp. 370-373, April 1988, But this algorithm departs even farther from the theoretical basis of analysis.
Many techniques for the digital generation of musical sounds have been studied, and many are used in commercially available music synthesizers. In all of these techniques a basic tradeoff is encountered; namely, the conflict between accuracy and generality (defined as the ability to model a wide variety of sounds) on the one hand and computational efficiency on the other. Some techniques, such as frequency modulation (FM) synthesis as described by J. M. Chowning, "The Synthesis of Complex Audio Spectra by Means of Frequency Modulation," J. Audio Eng. Soc., vol. 21, pp. 526-534, September 1973, are computationally efficient and can produce a wide variety of new sounds, but lack the ability to accurately model the sounds of existing musical instruments.
On the other hand, sinusoidal additive synthesis implemented using the DPV is capable of analyzing the sound of a given instrument, synthesizing a perfect replica and performing a wide variety of modifications. However, as previously mentioned, the amount of computation needed to calculate the large number of time-varying sinusoidal components required prohibits real-time synthesis using relatively inexpensive hardware. As in the case of time-frequency speech modeling, the computational problems of additive synthesis of musical tones may be addressed by formulating the DPV in terms of the DSTFT and to implement this formulation using FFT algorithms. Unfortunately, this strategy produces the same type of distortion when applied to musical tone synthesis as to speech synthesis.
There clearly exists a need for better methods and devices for the analysis, synthesis and modification of audio waveforms. In particular, an analysis/synthesis system capable of altering the pitch frequency and articulation rate of speech and music signals and capable of operating with low computational requirements and therefore low hardware cost would satisfy long-felt needs and would contribute significantly to the art.
SUMMARY OF THE INVENTION
The present invention addresses the above described limitations of the prior art and achieves a technical advance by provision of a method and structural embodiment comprising: an analyzer responsive to either speech or musical tone signals which for each of a plurality of overlapping data frames extracts and stores parameters which serve to represent input signals in terms of an overlap-add, quasi-harmonic sinusoidal model, and; a synthesizer responsive to the stored parameter set previously determined by analysis to produce a synthetic facsimile of the analyzed signal or alternately a synthetic audio signal advantageously modified in time-, frequency- or pitch-scale.
In one embodiment of the present invention appropriate for speech signals, the analyzer determines a time-varying gain signal representative of time-varying energy changes in the input signal. This time-varying gain is incorporated in the synthesis model and acts to improve modeling accuracy during transient portions of a signal. Also, given isolated frames of input signal and time-varying gain signal data the analyzer determines sinusoidal model parameters using a frequency-domain analysis-by-synthesis procedure implemented using a Fast Fourier Transform (FFT) algorithm. Advantageously, this analysis procedure overcomes inaccuracies encountered with discrete Fourier transform "peak-picking" analysis as used in the Sine-Wave System, while maintaining a comparable computational load. Furthermore, a novel fundamental frequency estimation algorithm is employed which uses knowledge gained from analysis to improve computational efficiency over prior art methods.
The synthesizer associated with this embodiment advantageously uses a refined modification model, which allows modified synthetic speech to be produced without the objectionable artifacts typically associated with modification using the DSTFT and other prior art methods. In addition, overlap-add synthesis may be implemented using an FFT algorithm, providing improved computational efficiency over prior art methods without departing significantly from the synthesis model used in analysis.
The synthesizer also incorporates an improved phase coherence preservation algorithm which provides higher quality modified speech. Furthermore, the synthesizer performs pitch-scale modification using a phasor interpolation procedure. This procedure eliminates the problems of information loss and noise migration often encountered in prior art methods of pitch modification.
In an embodiment of the present invention appropriate for musical tone signals, a harmonically-constrained analysis-by-synthesis procedure is used to determine appropriate sinusoidal model parameters and a fundamental frequency estimate for each frame of signal data. This procedure allows for fine pitch tracking over the analyzed signal without significantly adding to the computational load of analysis. Due to a priori knowledge of pitch, the synthesizer associated with this embodiment uses a simple functional constraint to maintain phase coherence, significantly reducing the amount of computation required to perform modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a system level block diagram of a speech analyzer according to the present invention showing the required signal processing elements and their relationship to the flow of the information signals.
FIG. 2 is a flowchart illustrating the information processing task which takes place in the time-varying calculator block of FIG. 1.
FIG. 3 is an illustration of overlap-add synthesis, showing the relationship of windowed synthetic contributions and their addition to form a synthesis frame of s n!.
FIG. 4 is a functional block diagram illustrating the closed-loop analysis-by-synthesis procedure used in the invention.
FIGS. 5 and 6 are flowcharts showing the information processing tasks achieved by the analysis-by-synthesis block of FIG. 1.
FIGS. 7-9 are flowcharts showing the information processing tasks achieved by the fundamental frequency estimator block of FIG. 1.
FIG. 10 is a flowchart showing the information processing tasks achieved by the harmonic assignment block of FIG. 1.
FIG. 11 is a system level block diagram of a speech analyzer according to the present invention similar in operation to the speech analyzer of FIG. 1 but which operates without incorporating time-varying gain sequence σ n!.
FIG. 12 is a system level block diagram of a musical tone analyzer according to the present invention showing the required signal processing elements and their relationship to the flow of the information signals.
FIGS. 13-15 are flowcharts showing the information processing tasks achieved by the harmonically-constrained analysis-by-synthesis block of FIG. 12.
FIG. 16 is a system level block diagram of a musical tone analyzer according to the present invention similar in operation to the musical tone analyzer of FIG. 12 but which operates without incorporating time-varying gain sequence σ n!.
FIG. 17 is a system level block diagram of a speech synthesizer according to the present invention, showing the required signal processing elements and their relationship to the flow of the information signals.
FIGS. 18A and 18B are illustrations of distortion due to extrapolation beyond analysis frame boundaries. The phase coherence of s k n! is seen to break down quickly outside the analysis frame due to the quasi-harmonic nature of the model.
FIGS. 19A and 19B are illustrations of the effect of differential frequency scaling in the refined modification model. The phase coherence of the synthetic contribution breaks down more slowly due to "pulling in" the differential frequencies.
FIGS. 20 and 21 are flowcharts showing the information processing tasks achieved by the pitch onset time-estimator block of FIG. 17.
FIGS. 22A and 22B are illustrations of virtual excitation sequences in both the unmodified and modified cases, and of the coherence constraint imposed on the sequences at boundary C'.
FIGS. 23 and 24 are flowcharts showing the information processing tasks achieved by the speech synthesizer DFT assignment block of FIG. 17.
FIG. 25 is a system level block diagram of a speech synthesizer according to the present invention similar in operation to the speech synthesizer of FIG. 17 but which is capable of performing time- and pitch-scale modifications.
FIGS. 26 and 27 are flowcharts showing the information processing tasks achieved by the phasor interpolator block of FIG. 25.
FIG. 28 is a system level block diagram of a musical tone synthesizer according to the present invention showing the required signal processing elements and their relationship to the flow of the information signals.
FIG. 29 is a system level block diagram of a musical tone synthesizer according to the present invention similar in operation to the musical tone synthesizer of FIG. 28 but which is capable of performing time- and pitch-scale modifications.
FIG. 30 is a system level block diagram showing the architecture of a microprocessor implementation of the audio synthesis system of the present invention.
DETAILED DESCRIPTION
FIG. 1 illustrates an analyzer embodiment of the present invention appropriate for the analysis of speech signals. Speech analyzer 100 of FIG. 1 responds to an analog speech signal, denoted by s c (t) and received via path 120, in order to determine the parameters of a signal model representing the input speech and to encode and store these parameters in storage element 113 via path 129. Speech analyzer 100 digitizes and quantizes s c (t) using analog-to-digital (A/D) converter 101, according to the relation
s n!=Q{s.sub.c (n/F.sub.s)}, (1)
where F s is the sampling frequency in samples/sec and Q{·} represents the quantization operator of A/D converter 101. It is assumed that s c (t) is bandlimited to F s /2 Hz.
Time-varying gain calculator 102 responds to the data stream produced by A/D converter 101 to produce a sequence σ n! which reflects time-varying changes in the average magnitude of s n!. This sequence may be determined by applying a lowpass digital filter to |s n!|. One such filter is defined by the recursive relation
y.sub.i n!=λy.sub.i n-1!+(1-λ)y.sub.i-1 n!, 1≦i≦I, (2)
where y 0 n!=|s n!|. The time-varying gain sequence is then given by
σ n!=y.sub.I n+n.sub.σ !, (3)
where n.sub.σ is the delay in samples introduced by filtering. The frequency response of this filter is given by ##EQU1## where the filter parameters λ and I determine the frequency selectivity and rolloff of the filter, respectively. For speech analysis, a fixed value of I=20 is appropriate, while λ is varied as a function of F s according to
λ=0.9.sup.F.sbsp.s.sup./8000, (5)
assuring that the filter bandwidth is approximately independent of the sampling frequency. The filter delay n.sub.σ can then be determined as ##EQU2## where <·> represents the "round to nearest integer" operator. A flowchart of this algorithm is shown in FIG. 2. Time-varying gain calculator 102 transmits σ n! via path 121 to parameter encoder 112 for subsequent transmission to storage element 113.
It should be noted that any components of s n! with frequencies close to F s /2 will be "aliased" into low-frequency components by the absolute value operator |·|, which can cause distortion in σ n!. Therefore, it is advisable to apply a lowpass filter to any s n! known to contain significant high-frequency energy before taking the absolute value. Such a filter need only attenuate frequencies near F s /2, thus it need not be complicated. One example is the simple filter defined by
s' n!=0.25s n-1!+0.5s n!+0.25s n+1!. (7)
Consider now the operation of speech analyzer 100 in greater detail. The signal model used in the invention to represent s n! is an overlap-add sinusoidal model formulation which produces an approximation to s n! given by ##EQU3## where σ n! controls the time-varying intensity of s n!, w s n! is a complementary synthesis window which obeys the constraint ##EQU4## and s k n!, the k-th synthetic contribution, is given by ##EQU5## where ω j k =2πf j k /F s and where 0≦f j k ≦F s /2. The "synthesis frame length" N s typically corresponds to between 5 and 20 msec, depending on application requirements. While an arbitrary complementary window function may be used for w s n!, a symmetric, tapered window such as a Hanning window of the form ##EQU6## is typically used. With this window, a synthesis frame of N s samples of s n! may be written as
s n+kN.sub.s !=σ n+kN.sub.s !(w.sub.s n!s.sup.k n!+w.sub.s n-N.sub.s !s.sup.k+1 n-N.sub.s !), (12)
for 0≦n<N s . FIG. 3 illustrates a synthesis frame and the overlapping synthetic sequences which produce it.
Given σ n!, the objective of analysis is to determine amplitudes {A j k }, frequencies {ω j k } and phases {φ j k } for each s k n! in Equation 8 such that s n! is a "closest approximation" to s n! in some sense. An approach typically employed to solve problems of this type is to minimize the mean-square error ##EQU7## in terms of the parameters of s n!. However, attempting to solve this problem simultaneously for all the parameters may not be practical.
Fortunately, if s n! is approximately stationary over short time intervals, it is feasible to solve for the amplitude, frequency and phase parameters of s k n! in isolation by approximating s n! over an analysis frame of length 2N a +1 samples centered at n=kN s . The overlapping frames of speech data and the accompanying frames of envelope data required for analysis are isolated from s n! and σ n! respectively using frame segmenter blocks 103. The synthetic contribution s k n! may then be determined by minimizing ##EQU8## with respect to the amplitudes, frequencies and phases of s k n!.
The analysis window w a n! may be an arbitrary positive function, but is typically a symmetric, tapered window which serves to force greater accuracy at the frame center, where the contribution of s k n! to s n! is dominant. One example is the Hamming window, given by ##EQU9## The analysis frame length may be a fixed quantity, but it is desirable in certain applications to have this parameter adapt to the expected pitch of a given speaker. For example, as discussed in U.S. Pat. No. 4,885,790, issued to R. J. McAulay et al, the analysis frame length may be set to 2.5 times the expected average pitch period of the speaker to provide adequate frequency resolution. In order to ensure the accuracy of s n!, it is necessary that N a ≧N s .
Defining x n! and g n! by ##EQU10## and making use of Equation 10, E k may be rewritten as ##EQU11## where frame notation has been omitted to simplify the equations. Unfortunately, without a priori knowledge of the frequency parameters, this minimization problem is highly nonlinear and therefore very difficult to solve.
As an alternative, a slightly suboptimal but relatively efficient analysis-by-synthesis algorithm may be employed to determine the parameters of each sinusoid successively. This algorithm operates as follows: Suppose the parameters of l-1 sinusoids have been determined previously, yielding the successive approximation to x n!, ##EQU12## and the successive error sequence
e.sub.l-1 n!=x n!-x.sub.l- 1 n!. (19)
Given the initial conditions x 0 n!=0 and e 0 n!=x n!, these sequences may be updated recursively by
x.sub.l n!=x.sub.l-1 n!+g n!A.sub.l cos(ω.sub.l n+φ.sub.l)
e.sub.l n!=e.sub.l-1 n!-g n!A.sub.l cos(ω.sub.l n+φ.sub.l), (20)
for l≧1. The goal is then to minimize the squared successive error norm E l , given by ##EQU13## in terms of A l , ω l and φ l .
At this point it is still not feasible to solve simultaneously for the parameters due to the embedded frequency and phase terms. However, assuming for the moment that ω l is fixed and recalling the trigonometric cos(α+β)=cosαcosβ-sinαsinβ,
the expression for E l becomes ##EQU14## In this case the problem is clearly in the form of a linear least-squares approximation which when optimized in terms of a l and b l yields "normal equations" of the form
a.sub.l γ.sub.11 +b.sub.l γ.sub.12 =ψ.sub.1
a.sub.l γ.sub.12 +b.sub.l γ.sub.22 =ψ.sub.2, (23)
where ##EQU15## Solving for a l and b l gives
a.sub.l =(γ.sub.22 ψ.sub.1 -γ.sub.12 ψ.sub.2)/Δ
b.sub.l =(γ.sub.11 ψ.sub.2 -γ.sub.12 ψ.sub.1)/Δ, (25)
where Δ=γ 11 γ 22 -γ 12 2 . By the Principle of Orthogonality, given a l and b l , E l can be expressed as
E.sub.l =E.sub.l-1 -a.sub.l ψ.sub.1 -b.sub.l ψ.sub.2. (26)
Having determined a l and b l , A l and φ l are then given by the relations
A.sub.l =(a.sub.l.sup.2 +b.sub.l.sup.2).sup.1/2
φ.sub.l =-tan.sup.-1 (b.sub.l /a.sub.l). (27)
This establishes a method for determining the optimal amplitude and phase parameters for a single sinusoidal component of s k n! at a given frequency. To determine an appropriate frequency for this sinusoid, an ensemble search procedure may be employed. While a variety of search strategies are possible, the most straightforward is an "exhaustive search." In this procedure, ω l is varied over a set of uniformly spaced candidate frequencies given by ω c i!=2iπ/M for 0≦i≦M/2 (assuming that M is an even number). For each ω c i!, the corresponding value of E l is calculated using Equation 26, and ω l is chosen as that value of ω c i! which yields the minimum error. A l and φ l are then chosen as the amplitude and phase parameters associated with that frequency value.
In order to guarantee that x l n! converges to x n!, it is necessary that M>2N a ; furthermore, in order to guarantee a level of accuracy which is independent of the analysis frame length, M should be proportional to N a , i.e.
M=υN.sub.a,
where υ is typically greater than six. Finally, to facilitate computation it is often desirable to restrict M to be an integer power of two. For example, given the above conditions a suitable value of M for the case when N a =80 would be M=512.
Having determined the parameters of the l-th component, the successive approximation and error sequences are updated by Equation 20, and the procedure is repeated for the next component. The number of components, J k!, may be fixed or may be determined in the analysis procedure according to various "closeness of fit" criteria well known in the art. FIG. 4 shows a functional block diagram of the analysis procedure just described, illustrating its iterative, "closed-loop" structure.
Due to a natural high-frequency attenuation in the vocal tract referred to as "spectral tilt," speech signals often have energy concentrated in the low-frequency range. This phenomenon, combined with the tendency of analysis-by-synthesis to select components in order of decreasing amplitude and with the fact that slight mismatches exist between speech signals and their sinusoidal representations, implies that analysis-by-synthesis tends to first choose high-amplitude components at low frequencies, then smaller sinusoids immediately adjacent in frequency to the more significant components. This "clustering" behavior slows the analysis algorithm by making more iterations necessary to capture perceptually important high-frequency information in speech. Furthermore, low-amplitude components clustered about high-amplitude components are perceptually irrelevant, since they are "masked" by the larger sinusoids. As a result, expending extra analysis effort to determine them is wasteful.
Two approaches have been considered for dealing with the effects of clustering. First, since clustering is caused primarily because high-frequency components in speech have small amplitudes relative to low-frequency components, one solution is to apply a high-pass filter to s n! before analysis to make high-frequency components comparable in amplitude to low-frequency components. In order to be effective, the high-pass filter should approximately achieve a 6 dB/octave gain, although this is not critical. One simple filter which works well is defined by
s.sub.pf n!=s n!-0.9s n-1!. (28)
Since in this approach the "prefiltered" signal s pf n! is modeled instead of s n!, the effects of prefiltering must be removed before producing synthetic speech. This may be done either by applying the inverse of the filter given by Equation 28 to s n!, or by removing the effects from the model parameters directly, using the formulas
A'.sub.j =A.sub.j /|G(e.sup.jω.sbsp.l)|
φ'.sub.j =φ.sub.j -∠G(e.sup.jω.sbsp.l), (29)
where
G(e.sup.jω)=1-0.9e.sup.-jω.
A second approach to the problem of clustering is based on the observation that low-amplitude sinusoids tend to cluster around a high-amplitude sinusoid only in the frequency range corresponding to the main lobe bandwidth of W a (e j ω), the frequency spectrum of w a n!. Thus, given a component with frequency ω l determined by analysis-by-synthesis, it may be assumed that no perceptually important components lie in the frequency range
ω.sub.l -B.sub.m1 /2≦ω≦ω.sub.l +B.sub.m1 /2, (30)
where B m1 is the main lobe bandwidth of W a (e j ω). The frequency domain characteristics of a number of tapered windows are discussed by A. V. Oppenheim and R. W. Schafer in Discrete-Time Signal Processing, Englewood Cliffs, N.J.: Prentice-Hall, 1989, pp. 447-449. Therefore, the proposed analysis-by-synthesis algorithm may be modified such that once a component with frequency ω l has been determined, frequencies in the range given by Equation 30 are eliminated from the ensemble search thereafter, which ensures that clustering will not occur.
The amount of computation required to perform analysis-by-synthesis is reduced greatly by recognizing that many of the required calculations may be performed using a Fast Fourier Transform (FFT) algorithm. The M-point discrete Fourier transform (DFT) of an M-point sequence x n! is defined by ##EQU16## where
W.sub.M.sup.mn =e.sup.-j(2π/M)mn. (32)
When x n! is a real-valued sequence the following identities hold: ##EQU17## For the purposes of analysis-by-synthesis the M-point DFT's of e l-1 n!g n! and g 2 n! are written as ##EQU18## Noting that W M m (n+M) =W M mn , these DFT's may be case in the form of Equation 31 (provided that M>2N a ) by adding M to the negative summation index values and zero-padding the unused index values.
Consider now the inner product expressions which must be calculated in the analysis-by-synthesis algorithm. From Equation 24, for the case of ω l =ω c i!=2iπ/M, γ 11 is given by ##EQU19## Using Equation 33 and recalling that cos 2 θ=1/2+1/2cos2θ, this becomes
γ.sub.11 =1/2GG 0!+1/2 e{GG 2i!}. (36)
Similarly, expressions for γ 12 and γ 22 can also be derived:
γ.sub.12 =-1/2 m{GG 2i!}
γ.sub.22 =1/2GG 0!-1/2 e{GG 2i!}. (37)
The first three parameters may therefore be determined from the stored values of a single DFT which need only be calculated once per analysis frame using an FFT algorithm, provided that M is a highly composite number. Furthermore, if M is an integer power of 2, then the particularly efficient "radix-2" FFT algorithm may be used. A variety of FFT algorithms are described by A. V. Oppenheim and R. W. Schafer in Discrete-Time Signal Processing, Englewood Cliffs, N.J.: Prentice-Hall, 1989.
Similar expressions for ψ 1 and ψ 2 can be derived directly from the DFT identities given above:
ψ.sub.1 = e{EG.sub.l-1 i!} (38)
and
ψ.sub.2 =- m{EG.sub.l-1 i!}. (39)
These parameters may thus be expressed in terms of the stored values of EG l-1 m!. However, since e l-1 n! changes for each new component added to the approximation, EG l-1 m! must be computed J k! times per frame. In order to reduce the amount of computation further, the identities described above may be used to update this DFT sequence.
According to Equation 20, the updated error sequence after the l-th component, e l n!, is given by
e.sub.l n!=e.sub.l-1 n!-A.sub.l g n!cos(ω.sub.l n+φ.sub.l). (40)
From this it is clear that the updated DFT EG l m! is then ##EQU20## Recalling that ω l =2πi l /M, this becomes
EG.sub.l m!=EG.sub.l-1 m!-1/2A.sub.l e.sup.jφ.sbsp.l GG ((m-i.sub.l)).sub.M !-1/2A.sub.l e.sup.-jφ.sbsp.l GG ((m+i.sub.l)).sub.M !, (42)
where ((·)) M denotes the "modulo M" operator. EG l m! can therefore be expressed as a simple linear combination of EG l-1 m! and circularly shifted versions of GG m!; this establishes a fast method of analysis-by-synthesis which operates in the frequency domain. A flowchart of this algorithm is given in FIGS. 5 and 6.
It should be apparent to those skilled in the art that there are occasions when EG l m! will be a useful quantity in and of itself. For instance, if the goal of analyzing a signal made up of sinusoidal components plus noise is to determine the Fourier transform of the noise term, then EG l m! corresponds to this quantity after removing the sinusoidal signal components.
Recalling that e o n!=x n!, then according to Equation 34, ##EQU21## Substituting the definitions of x n! and g n! from Equation 16, XG m! and GG m! may be written as ##EQU22## that is, XG m! and GG m!, the two functions required for fast analysis-by-synthesis, are the zero-padded M-point DFT's of the sequences x n!g n! and g 2 n!, respectively. This first sequence is the product of the speech data frame and the envelope data frame multiplied by the analysis window function w a n!; likewise, g 2 n! is simply the square of the envelope data frame multiplied by w a n!.
Referring to FIG. 1, multiplier block 104 responds to a frame of speech data received via path 123 and a frame of envelope data received via path 122 to produce the product of the data frames. Analysis window block 106 multiplies the output of multiplier block 104 by the analysis window function ω a n!, producing the sequence x n!g n! described above. Squarer block 105 responds to a frame of envelope data to produce the square of the data frame; the resulting output is input to a second analysis window block to produce the sequence g 2 n!. At this point x n!g n! and g 2 n! are input to parallel Fast Fourier Transform blocks 107, which yield the M-point DFT's XG m! and GG m!, respectively. Analysis-by-synthesis block 108 responds to the input DFT's XG m! and GG m! to produce sinusoidal model parameters which approximate the speech data frame, using the fast analysis-by-synthesis algorithm discussed above. The resulting parameters are the amplitudes {A j k }, frequencies {ω j k } and phases {φ j k } which produce s k n!, as shown in Equation 10.
System estimator 110 responds to a frame of speech data transmitted via path 123 to produce coefficients representative of H(e j ω), an estimate of the frequency response of the human vocal tract. Algorithms to determine these coefficients include linear predictive analysis, as discussed in U.S. Pat. No. 3,740,476, issued to B. S. Atal, and homomorphic analysis, as discussed in U.S. Pat. No. 4,885,790, issued to R. J. McAulay et al. System estimator 110 then transmits said coefficients via path 124 to parameter encoder 112 for subsequent transmission to storage element 113.
In order to perform speech modifications using a sinusoidal model it is necessary for the frequency parameters associated with a given speech data frame to reflect the pitch information embedded in the frame. To this end, k n! may be written in quasi-harmonic form: ##EQU23## where ω j k =jω o k +Δ j k , and where J k! is now the greatest integer such that J k!ω o k ≦π. Note that only one component is associated with each harmonic number j. With this formulation, the fundamental frequency ω o k =2πf o k /F s must now be determined.
Fundamental frequency estimator 109 responds to the analyzed model parameter set from analysis-by-synthesis block 108 and to vocal tract frequency response coefficients received via path 124 to produce an estimate of the fundamental frequency ω o k of Equation 45. While many approaches to fundamental frequency estimation may be employed, a novel algorithm which makes use of the analyzed sinusoidal model parameters in a fashion similar to the algorithm disclosed by McAulay and Quatieri in "Pitch Estimation and Voicing Detection Based on a Sinusoidal Speech Model," Proc. IEEE Int'l Conf. on Acoust., Speech and Signal Processing, pp. 249-252, April 1990, is described here: If ω o k is defined as that value of ω which minimizes the error induced by quantizing the frequency parameters to harmonic values, ##EQU24## then ω o k is approximately equal to ##EQU25## assuming that N a is on the order of a pitch period or larger. This estimate is simply the average of {ω i k /i} weighted by (iA i k ) 2 .
Again suppressing frame notation, given an initial fundamental frequency estimate ω' o =2πf' o /F s , it is possible to arrange a subset of the analyzed sinusoidal model parameters in the quasi-harmonic form of Equation 45 and to update the fundamental frequency estimate recursively. This is accomplished by passing through the frequency parameters in order of decreasing amplitude and calculating each frequency's harmonic number, defined as <ω j /ω o >. If this equals the harmonic number of any previous component, the component is assigned to the set of parameters which are excluded from the quasi-harmonic representation; otherwise, the component is included in the quasi-harmonic set, and its parameters are used to update ω o according to Equation 47. Any harmonic numbers left unassigned are associated with zero-amplitude sinusoids at appropriate multiples of the final value of ω o .
In the case of speech signals, the above algorithm must be refined, since a reliable initial estimate is usually not available. The following procedure is used to define and choose from a set of candidate fundamental frequency estimates: Since, in conditions of low-energy, wideband interference, high-amplitude components correspond to signal components, it may be assumed that the frequency f of the highest amplitude component whose frequency is in the range from 100 to 1000 Hz is approximately some multiple of the actual pitch frequency, i.e. f o ≈f/i for some i.
In order to determine an appropriate value of i, a set of values of i are determined such that f/i falls in the range from 40 to 400 Hz, the typical pitch frequency range for human speech. For each i in this set the recursive fundamental frequency estimation algorithm is performed as described above, using an initial frequency estimate of ω' o i!=2πf' o i!/F s , where f' o i!=f/i. Given the resulting refined estimate, a measure of the error power induced over the speech data frame by fixing the quasi-harmonic frequencies to harmonic values may be derived, yielding ##EQU26##
Due to the inherent ambiguity of fundamental frequency estimates, a second error measure is necessary to accurately resolve which candidate is most appropriate. This second quantity is a measure of the error power induced by independently organizing the parameters in quasi-harmonic form and quantizing the amplitude parameters to an optimal constant multiple of the vocal tract spectral magnitude at the component frequencies, given by ##EQU27## where P e is the power of the parameter set excluded from the quasi-harmonic representation, ##EQU28##
At this point a composite error function P T i! is constructed as P T i!=P f +P a , and the refined estimate ω o i! corresponding to the minimum value of P T i! is chosen as the final estimate ω o . This algorithm is illustrated in flowchart form by FIGS. 7 and 9. In the case where interference is sufficiently strong or narrowband that the analyzed component at frequency f cannot be assumed to be a signal component, then the algorithm described above nay still be employed, using a predefined set of candidate frequencies which are independent of the analyzed parameters. Fundamental frequency estimator 109 then transmits ω o via path 125 to parameter encoder 112 for subsequent transmission to storage element 113.
Harmonic assignment block 111 responds to the fundamental frequency estimate ω o and the model parameters determined by analysis-by-synthesis to produce a quasi-harmonic parameter set as in Equation 45. This is accomplished by assigning each successive component a harmonic number given by <ω j /ω o > in order of decreasing amplitude, refraining from assigning components whose harmonic numbers conflict with those of previously assigned components. The resulting parameter set thus includes as many high-amplitude components as possible in the quasi-harmonic parameter set. The harmonic assignment algorithm is illustrated in flowchart form by FIG. 10. Harmonic assignment block 111 then transmits the quasi-harmonic model amplitudes {A j k }, differential frequencies {Δ j k } and phases {φ j k } via paths 126, 127 and 128 respectively, to parameter encoder 112 for subsequent transmission to storage element 113.
While the time-varying gain sequence σ n! acts to increase model accuracy during transition regions of speech signals and improves the performance of analysis in these regions, it is not absolutely required for the model to function, and the additional computation required to estimate σ n! may outweigh the performance improvements for certain applications. Therefore, a second version of a speech analyzer which operates without said time-varying gain (equivalent to assuming that σ n!=1) is illustrated in FIG. 11.
Speech analyzer 1100 operates identically to speech analyzer 100 with the following exceptions: The signal path dedicated to calculating, transmitting and framing σ n! is eliminated, along with the functional blocks associated therewith. A second difference is seen by considering the formulas giving DFT's XG m! and GG m! in Equation 44 for the case when σ n!=1; ##EQU29## That is, XG m! is now the DFT of the speech data frame multiplied by the analysis window, and GG m! is simply the DFT of the analysis window function, which may be calculated once and used as a fixed function thereafter.
Analysis window block 1103 responds to a frame of speech data received via path 1121 to multiply said data frame by the analysis window function w a n! to produce the sequence x n!g n!. Fast Fourier Transform block 1105 responds to x n!g n! to produce the M-point DFT XG m! defined above. Read-only memory block 1104 serves to store the precalculated DFT GG m! defined above and to provide this DFT to analysis-by-synthesis block 1106 as needed. All other algorithmic components of speech analyzer 1100 and their structural relationships are identical to those of speech analyzer 100.
FIG. 12 illustrates an analyzer embodiment of the present invention appropriate for the analysis of pitched musical tone signals. Musical tone analyzer 1200 of FIG. 12 responds to analog musical tone signals in order to determine sinusoidal model parameters in a fashion similar to speech analyzer 100. Musical tone analyzer 1200 digitizes and quantizes analog musical signals received via path 1220 using A/D converter 1201 in the same manner as A/D converter 101
Time-varying gain calculator 1202 responds to the data stream produced by A/D converter 1201 to produce an envelope sequence σ n! as described in speech analyzer 100. The same filtering operation of Equation 2 is used; however, the filter parameters λ and n.sub.σ are varied as a function of the nominal expected pitch frequency of the tone, ω' o , received via path 1221 according to the relation ##EQU30## where ξ=2-cosω' o , and n.sub.σ is calculated using Equation 6. The purpose of this variation is to adjust the filter's selectivity to the expected pitch in order to optimize performance. Time-varying gain calculator 1202 transmits σ n! via path 1222 to parameter encoder 1210 for subsequent transmission to storage element 1211.
Overlapping frames of musical signal data and the accompanying frames of envelope data required for analysis are isolated from s n! and σ n! respectively using frame segmenter blocks 1203 in the same manner as in speech analyzer 100. Multiplier block 1204 responds to a musical signal data frame received via path 1223 and an envelope data frame received via path 1224 to produce the product of the data frames. Analysis window block 1206 multiplies the output of multiplier block 1204 by the analysis window function described in speech analyzer 100, producing the product of the sequences x n! and g n! defined by Equation 16. Squarer block 1205 responds to a frame of envelope data to produce the square of the envelope data frame; the resulting output is input to a second analysis window block to produce the sequence g 2 n!. At this point x n!g n! and g 2 n! are input to parallel Fast Fourier Transform blocks 1207, which yield the M-point DFT's XG m! and GG m! defined in Equation 44, respectively.
Harmonically-constrained analysis-by-synthesis block 1208 responds to the input DFT's XG m! and GG m! and to ω' o to produce sinusoidal model parameters which approximate the musical signal data frame. These parameters produce s k n! using the quasi-harmonic representation shown in Equation 45. The analysis algorithm used is identical to the fast analysis-by-synthesis algorithm discussed in the description of speech analyzer 100, with the following exception: Since an unambiguous initial fundamental frequency estimate is available, as each candidate frequency ω c i! is tested to determine the l-th component of x n!, its harmonic number is calculated as <ω c i!/ω o k >. If this equals the harmonic number of any of the previous l-1 components, the candidate is disqualified, ensuring that only one component is associated with each harmonic number. As each new component is determined, the estimate of ω o k is updated according to Equation 47. This algorithm is illustrated in flowchart form by FIGS. 13 through 15.
Harmonically-constrained analysis-by-synthesis block 1208 then transmits the fundamental frequency estimate ω o k and the quasi-harmonic model amplitudes {A j k }, differential frequencies {Δ j k } and phases {φ j k } via paths 1225, 1226, 1227 and 1228 respectively, to parameter encoder 1210 for subsequent transmission to storage element 1211. System estimator 1209 responds to a musical signal data frame transmitted via path 1223 to produce coefficients representative of H(e j ω), an estimate of the spectral envelope of the quasi-harmonic sinusoidal model parameters. The algorithms which may be used to determine these coefficients are the same as those used in system estimator 110. System estimator 1209 then transmits said coefficients via path 1229 to parameter encoder 1210 for subsequent transmission to storage element 1211.
As previously mentioned, the time-varying gain sequence σ n! is not required for the model to function; therefore, a second version of a musical tone analyzer that operates without said time-varying gain is illustrated in FIG. 16. Musical tone analyzer 1600 incorporates the same alterations as described in the discussion of speech analyzer 200. Furthermore, although the spectral envelope H(e j ω) is required to perform pitch-scale modification of musical signals, when this type of modification is not performed the spectral envelope is not required in musical tone analysis. In this case, signal paths 1229 and 1620 and functional blocks 1209 and 1601 are omitted from analyzers 1200 and 1600, respectively.
FIG. 17 illustrates a synthesizer embodiment of the present invention appropriate for the synthesis and modification of speech signals. Speech synthesizer 1700 of FIG. 17 responds to stored encoded quasi-harmonic sinusoidal model parameters previously determined by speech analysis in order to produce a synthetic facsimile of the original analog signal or alternately synthetic speech advantageously modified in time- and/or frequency-scale.
Parameter decoder 1702 responds to the stored encoded parameters transmitted from storage element 1701 via path 1720 to yield the time-varying gain sequence σ n! of Equation 8 (if calculated in analysis), the coefficients associated with vocal tract frequency response estimate H(e j ω) discussed in the description of speech analyzer 100, and the fundamental frequency estimate ω o k , quasi-harmonic model amplitudes {A j k }, differential frequencies {Δ j k } and phases {φ j k } used to generate a synthetic contribution according to Equation 45. Although storage element 1701 is shown to be distinct from storage element 113 of speech analyzer 100, it should be understood that speech analyzer 100 and speech synthesizer 1700 may share the same storage element.
Consider now the operation of speech synthesizer 1700 in greater detail. Referring to Equations 12 and 45, time- and frequency-scale modification may be performed on isolated synthesis frames, using different time and frequency scale factors in each successive frame if desired. A simple approach to time-scale modification by a factor ρ k using the overlap-add sinusoidal model is to change the length of synthesis frame k from N s to ρ k N s with corresponding time scaling of the envelope sequence σ n! and the synthesis window w s n!. Frequency-scale modification by a factor β k is accomplished by scaling the component frequencies of each synthetic contribution s k n!. In either case, time shifts are introduced to the modified synthetic contributions to account for changes in phase coherence due to the modifications.
Unfortunately, this simple approach yields modified speech with reverberant artifacts as well as a noisy, "rough" quality. Examination of Equation 45 reveals why. Since the differential frequencies {Δ j k } are nonzero and independent, they cause the phase of each component sinusoid to evolve nonuniformly with respect to other components. This "phase evolution" results in a breakdown of coherence in the model as the time index deviates beyond analysis frame boundaries, as illustrated in FIGS. 18A and 18B. Time-shifting this extrapolated sequence therefore introduces incoherence to the modified speech.
The present invention overcomes the problem of uncontrolled phase evolution by altering the component frequencies of s k n! in the presence of modifications according to the relation
jβ.sub.k ω.sub.o.sup.k +Δ.sub.j.sup.k /ρ.sub.k.
This implies that as the time scale factor ρ k is increased, the component frequencies "pull in" towards the harmonic frequencies, and in the limit the synthetic contributions become purely periodic sequences. The effect is to slow phase evolution, so that coherence breaks down proportionally farther from the analysis frame center to account for the longer synthesis frame length. The behavior of a synthetic contribution modified in this way is illustrated in FIGS. 19A and 19B.
Based on this new approach, a synthesis equation similar to Equation 12 may be constructed:
s n+N.sub.k !=σ .sup.n +kN.sub.s !{w.sub.s .sup.n !s.sub.ρk.βk.sup.k n!+w.sub.s .sup.n -N.sub.s !s.sub.ρk.βk+1.sup.k+1 n-ρ.sub.k N.sub.s !}, (55)
for 0≦n<ρ k N s , where N k =N s Σ i=0 k-1 ρ i is the starting point of the modified synthesis frame, and where ##EQU31##
Techniques for determining the time shifts δ k and δ k+1 will be discussed later. It should be noted that when β k >1, it is possible for the component frequencies of s.sub.ρk,βk n! to exceed π, resulting in "aliasing." For this reason it is necessary to set the amplitude of any component whose modified frequency is greater than π to zero.
Pitch onset time estimator 1703 responds to the coefficients representing H(e j ω) received via path 1721, the fundamental frequency estimate received via path 1722, and the quasi-harmonic model amplitudes, differential frequencies and phases received via paths 1723, 1724 and 1725 respectively in order to estimate the time relative to the center of an analysis frame at which an excitation pulse occurs. This function is achieved using an algorithm similar to one developed by McAulay and Quatieri in "Phase Modelling and its Application to Sinusoidal Transform Coding," Proc. IEEE Int'l Conf. on Acoust., Speech and Signal Processing, pp. 1713-1715, April 1986, and based on the observation that the glottal excitation sequence (which is ideally a periodic pulse train) may be expressed using the quasi-harmonic sinusoidal representation of Equations 8 and 45, where the synthetic contributions s k n! are replaced by ##EQU32## and where the amplitude and phase parameters of e k n! are given by
b.sub.l.sup.k =A.sub.l.sup.k /|H(e.sup.jω.sbsp.l.spsp.k)|
θ.sub.l.sup.k=φ.sub.l.sup.k -∠H(e.sup.jω.sbsp.l.spsp.k). (58)
This process is referred to as "deconvolution." Assuming for simplicity that ω l k =lω o k and suppressing frame notation, Equation 57 may be rewritten as ##EQU33## where
ψ.sub.l (τ.sub.p)=θ.sub.l +lω.sub.o τ.sub.p. (60)
One of the properties of the vocal tract frequency response estimate H(e j ω) is that the amplitude parameters A l k are approximately proportional to the magnitude of H(e j ω) at the corresponding frequencies ω l k ; thus, the deconvolved amplitude parameters {b l k } are approximately constant. If, in addition, the "time-shifted" deconvolved phase parameters {ψ l (τ p )} are close to zero or π for some value of τ p (termed "maximal coherence"), then e k n! is approximately a periodic pulse train with a "pitch onset time" of τ p . By assuming the condition of maximal coherence, an approximation to s k n! may be constructed by reversing the deconvolution process of Equation 58, yielding ##EQU34## where m is either zero or one.
The pitch onset time parameter τ p may then be defined as that value of τ which yields the minimum mean-square error between s k n! and s.sub.τ k n! over the original analysis frame, ##EQU35## Assuming that N a is a pitch period or more, this is approximately equivalent to finding the absolute maximum of the pitch onset likelihood function ##EQU36## in terms of τ. Unfortunately, this problem does not have a closed-form solution; however, due to the form of ψ l (τ), L(τ) is periodic with period 2π/ω o . Therefore, the pitch onset time may be estimated by evaluating L(τ) at a number (typically greater than 128) of uniformly spaced points on the interval -π/ω o ,π/ω o ! and choosing τ p to correspond to the maximum of |L(τ)|. This algorithm is shown in flowchart form in FIGS. 20 and 21.
DFT assignment block 1704 responds to the fundamental frequency ω o k received via path 1722, the sets of quasi-harmonic model amplitudes, differential frequencies and phases received via paths 1723, 1724 and 1725 respectively, pitch onset time estimate τ p k received via path 1726, frequency-scale modification factor β k and time-scale modification factor ρ k received via paths 1727 and 1728, respectively, to produce a sequence Z i! which may be used to construct a modified synthetic contribution using an FFT algorithm.
Consider the operation of DFT assignment block 1704 in greater detail. Referring to Equation 10, since the component frequencies of s k n! are given by ω l k =2πi l /M, a synthetic contribution may be expressed as ##EQU37## Recognizing that A l k cos(2πi l n/M+φ l k )= e{A l k e -j (2πi.sbsp.l n/M+ φ.sbsp.l.spsp.k.sub.) }, this becomes ##EQU38## Thus, by Equation 31, any sequence expressed as a sum of constant-amplitude, constant-frequency sinusoids whose frequencies are constrained to be multiples of 2π/M is alternately given as the real part of the M-point DFT of a sequence Z i! with values of A l k e -j φ.spsb.l.spsp.k at i=i l and zero otherwise. This DFT may be calculated using an FFT algorithm.
According to Equation 56, in the presence of time- and frequency-scale modification a synthetic contribution is given by ##EQU39## where
ω.sub.l.sup.k =β.sub.k lω.sub.o.sup.k +Δ.sub.l.sup.k /ρ.sub.k, (67)
ζ.sub.l.sup.k =φ.sub.l.sup.k +β.sub.k lω.sub.o.sup.k δ.sup.k. (68)
Except for the case when β k =ρ k =1, the modified frequency terms no longer fall at multiples of 2π/M; however, an FFT algorithm may still be used to accurately represent s.sub.ρk,βk k n!. Ignoring frame notation, this is accomplished by calculating the DFT indices whose corresponding frequencies are adjacent to ω l : ##EQU40## where · denotes the "greatest integer less than or equal to" operator.
The length of the DFT used in modification synthesis, M, is adjusted to compensate for the longer frame lengths required in time-scale modification and is typically greater than or equal to ρ k M. Each component of s.sub.ρk,βk k n! is then approximated using two components with frequencies ω 1 ,l =2πi 1 ,l /M and ω 2 ,l =2πi 2 ,l /M in the following manner: Given a single sinusoidal component with an unconstrained frequency ω l of the form
c.sub.l n!=A.sub.l cos(ω.sub.l n+ζ.sub.l)=a.sub.l cosω.sub.l n+b.sub.l sinω.sub.l n, (71)
two sinusoids with constrained frequencies are added together to form an approximation to c l n!: ##EQU41## Letting N s =ρ k N s and using the squared error norm ##EQU42## minimization of E l in terms of the coefficients of c l n! leads to the conditions ##EQU43##
Expanding the first condition using Equation 72 yields ##EQU44## Equations 71 and 72 may be substituted into this equation: however, noting that ##EQU45## for all α, β and N, the resulting expression simplifies to ##EQU46## Similarly, the other conditions of Equation 74 are given by the equations ##EQU47## Equations 76 and 77 form a pair of normal equations in the form of Equation 23 which may be solved using the formulas of Equation 25 for a 1 ,l and a 2 ,l ; likewise, Equations 78 and 79 are a second, independent pair of normal equations yielding b 1 ,l and b 2 ,l.
The inner product terms in Equations 76-79 may be calculated using the relations ##EQU48## where the function F N (ω), defined as ##EQU49## may be precalculated and used as required. Given the parameters determined from the two sets of normal equations, the amplitude and phase parameters of c l n! are derived using the relationships of Equation 27. The resulting amplitude and phase parameters can then be assigned to the M-point sequence Z i! as described previously at index values i 1 ,l and i 2 ,l.
In speech signals, synthetic contributions are highly correlated from one frame to the next. In the presence of modifications, this correlation must be maintained if the resulting modified speech is to be free from artifacts. To accomplish this, the time shifts δ k and δ k+1 in Equation 56 may be determined such that the underlying excitation signal obeys specific constraints in both the unmodified and modified cases. Examining Equation 59, if the component amplitudes are set to unity and the phases set to zero, a "virtual excitation" sequence, or an impulse train with fundamental frequency ω o k and shifted relative to the synthesis frame boundary by τ p k samples, results. In "Phase Coherence in Speech Reconstruction for Enhancement and Coding Applications," Proc. IEEE Int'l Conf. on Acoust., Speech and Signal Processing, pp. 207-210, May 1989, McAulay and Quatieri derive an algorithm to preserve phase coherence in the presence of modifications using virtual excitation analysis. The following is a description of a refined version of this algorithm.
As illustrated in FIGS. 22A and 22B, in synthesis frame k the unmodified virtual excitation of the k-th synthetic contribution has pulse locations relative to frame boundary A of τ p k +iT o k , where T o k =2π/ω o k . These impulses are denoted by O's. Likewise, the pulse locations of the virtual excitation of the (k+1)-st synthetic contribution relative to frame boundary B are τ p k+1 +iT o k+1 ; these pulses are denoted by X's. For some integer i k , a pulse location of the k-th contribution is adjacent to frame center C; likewise, for some i k+1 a pulse location of the k+1-st contribution is adjacent to frame center C. The values of i k and i k+1 can be found as
i.sub.k = (N.sub.s /2-τ.sub.p.sup.k)/T.sub.o.sup.k
i.sub.k+1 = -(N.sub.s /2+τ.sub.p.sup.k+1)/T.sub.o.sup.k+1 +1. (82)
The time difference between the pulses adjacent to frame center C is shown as Δ.
In the presence of time- and frequency-scale modification, the relative virtual excitation pulse locations are changed to n=(τ p k +iT o k )/β k -δ k and n=(τ p k+1 +iT o k+1 )/β k+1 -δ k+1 for modified synthetic contributions k and k+1, respectively. In order to preserve frame-to-frame phase coherence in the presence of modifications, the time shift δ k+1 must be adjusted such that the time difference between pulses adjacent to modified frame center C' is equal to Δ/β av , where β av =(β k +β k+1 )/2. This condition is also shown in FIGS. 22A and 22B. The coherence requirement leads to an equation which can be solved for δ k+1 , yielding the recursive relation ##EQU50## The algorithms involved in DFT assignment block 1704 are illustrated in flowchart form in FIGS. 23 and 24.
FFT block 1705 responds to the complex sequence Z i! produced by DFT assignment block 1704 to produce a complex sequence z n! which is the M-point DFT of Z i! according to Equation 31. Overlap-add block 1706 responds to the complex sequence output by FFT block 1705, time-scale modification factor ρ k received via path 1728, and time-varying gain sequence σ n! received via path 1729 to produce a contiguous sequence s n!, representative of synthetic speech, on a frame-by-frame basis. This is accomplished in the following manner: Taking the real part of the input sequence z n! yields the modified synthetic contribution sequence s.sub.ρk,βk k n! as in the discussion of DFT assignment block 1704. Using the relation expressed in Equation 55, a synthesis frame of s n! is generated by taking two successive modified synthetic contributions, multiplying them by shifted and time scaled versions of the synthesis window w s n!, adding the two windowed sequences together, and multiplying the resulting sequence by the time scaled time-varying gain sequence σ n!.
It should be understood that if speech analysis was performed without the time-varying gain sequence, then data path 1729 may be omitted from synthesizer 1700, and the overlap-add algorithm implemented with σ n!≡1. In addition, it should be readily apparent to those skilled in the art that if only time-scale modification is desired, data path 1727 may be omitted, and the modification algorithms described may be implemented with β k =1 for all k. Likewise, if only frequency-scale modification is desired, then data path 1728 may be omitted, and the modification algorithms described may be implemented with ρ k =1 for all k.
Given s n!, overlap-add block 1706 then produces an output data stream by quantizing the synthetic speech sequence using a quantization operator as in Equation 1. Digital-to-analog (D/A) converter 1707 responds to the data stream produced by overlap-add block 1706 to produce an analog signal s c (t) which is output from speech synthesizer 1700 via path 1730.
While time- and frequency-scale modification of analyzed speech is sufficient for many applications, for certain applications other information must be accounted for when performing modifications. For instance, when speech is frequency-scale modified using speech synthesizer 1700, the component frequencies used in the sinusoidal model are changed, but the amplitude parameters are unaltered except as required to prevent aliasing; this results in compression or expansion of the "spectral envelope" of analyzed speech (of which |H(e j ω)| is an estimate). Since identifiable speech sounds are critically determined by this envelope, such "spectral distortion" may seriously degrade the intelligibility of synthetic speech produced by synthesizer 1700. Therefore, it is important to consider an approach to altering the fundamental frequency of speech while preserving its spectral envelope; this is known as pitch-scale modification.
A second version of a speech synthesizer capable of performing time- and pitch-scale modification on previously analyzed speech signals is illustrated in FIG. 25. Speech synthesizer 2500 operates identically to speech synthesizer 1700, except that an additional step, phasor interpolator 2501, is added to counteract the effects of spectral distortion encountered in speech synthesizer 1700.
Phasor interpolator 2501 responds to the same set of parameters input to pitch onset time estimator 1703, the pitch onset time τ p k determined by pitch onset time estimator 2502 received via path 2520, and the pitch-scale modification factor β k received via path 2521 in order to determine a modified set of amplitudes {A j k }, harmonic differential frequencies {Δ j k }, and phases {φ j k } which produce a pitch-scale modified version of the original speech data frame.
Consider now the operation of phasor interpolator 2501 in greater detail: According to the discussion of pitch onset time estimator 1703, a synthetic contribution to the glottal excitation sequence as given in Equation 57 is approximately a periodic pulse train whose fundamental frequency is ω o k . In a manner similar to the pitch-excited LPC model, it might be expected that scaling the frequencies of e k n! by β k and "reconvolving" with H(e j ω) at the scaled frequencies {βω j k } would result in synthetic speech with a fundamental frequency of β k ω o k that maintains the same spectral shape of H(e j ω), and therefore the same intelligibility, as the original speech. Unfortunately, since the frequencies of e k n! span the range from zero to π, this approach results in component frequencies spanning the range from zero to β k π. For pitch scale factors less than one, this "information loss" imparts a muffled quality to the modified speech.
To address this problem, consider the periodic sequence obtained from e k n! by setting ω l k =lω o k : ##EQU51## The goal of modifying the fundamental frequency of e o k n! without information loss is to specify a set of modified amplitude and phase parameters for the modified residual e.sub.β n!, given by ##EQU52## (where J k!=J k!/β k ) which span the frequency range from zero to π. Since as a function of frequency the pairs of amplitude and phase parameters are evenly spaced, a reasonable approach to this problem is to interpolate the complex "phasor form" of the unmodified amplitude and phase parameters across the spectrum and to derive modified parameters by resampling this interpolated function at the modified frequencies.
Again suppressing frame notation, this implies that given the interpolated function (ω), where ##EQU53## the modified amplitudes are given by b l =| (βlω o )|, and the modified phases by θ l =∠ (βlω o ).
While any interpolation function I(ω) with the properties I(lω o )=0 for l≠0 and I(0)=1 may be employed, a raised-cosine interpolator of the form ##EQU54## makes the computation of (ω) much simpler, since all but two terms drop out of Equation 87 at any given frequency. Furthermore, since I(ω) is bandlimited, the effect of any single noise-corrupted component of e k n! on the modified parameters is strictly limited to the immediate neighborhood of that component's frequency. This greatly reduces the problem of inadvertently amplifying the background noise during modification by assuring that noise effects concentrated in one part of the spectrum do not "migrate" to another part of the spectrum where the magnitude of H(e j ω) may be greatly different.
The discussion of phasor interpolation to this point has ignored one important factor; the interpolated function (ω) is seriously affected by the phase terms {θ l }. To see this, consider the case when θ l =0 for all l; in this case, (ω) is simply a straightforward interpolation of the amplitude parameters. However, if every other phase term is π instead, (ω) interpolates adjacent amplitude parameters with opposite signs, resulting in a very different set of modified amplitude parameters. It is therefore reasonable to formulate phasor interpolation such that the effects of phase on the modified amplitudes is minimized.
As mentioned above, when the phase terms are all close to zero, phasor interpolation approximates amplitude interpolation. Furthermore, examining Equation 87 reveals that when the phase terms are all close to π, phasor interpolation is approximately interpolation of amplitudes with a sign change, and that deviation from either of these conditions results in undesirable nonlinear amplitude interpolation. Recalling the description of pitch onset time estimator 1703, τ p is estimated such that the "time-shifted" phase parameters {ψ l (τ p )} have exactly this property. Therefore, the phasor interpolation procedure outlined above may be performed using {ψ l (τ p )} instead of {θ l }, yielding the modified amplitude parameters {b l } and interpolated phases {ψ l (τ p )}. The modified phase terms may then be derived by reversing the time shift imparted to {ψ l (τ p )}:
θ.sub.l =ψ.sub.l (τ.sub.p)-lω.sub.o τ.sub.p. (89)
At this point all that remains is to specify appropriate differential frequency terms in the equation for e k n!. Although this task is somewhat arbitrary, it is reasonable to expect that the differential frequency terms may be interpolated uniformly in a manner similar to phasor interpolation, yielding ##EQU55## This interpolation has the effect that the modified differential frequencies follow the same trend in the frequency domain as the unmodified differentials, which is important both in preventing migration of noise effects and in modifying speech which possesses a noise-like structure in certain portions of the spectrum.
Given the amplitude, phase and differential frequency parameters of a modified excitation contribution, the specification of a synthetic contribution to pitch-scale modified speech may be completed by reintroducing the effects of the spectral envelope to the amplitude and phase parameters at the modified frequencies ω l k =β k lω o k +Δ l k :
A.sub.l.sup.k =b.sub.l.sup.k β.sub.k |H(e.sup.jω.sbsp.l.spsp.k)|
φ.sub.l.sup.k =θ.sub.l.sup.k +∠H(e.sup.jω.sbsp.l.spsp.k), (91)
where the multiplicative factor of β k on the amplitude parameters serves to normalize the amplitude of the modified speech. The algorithm used in phasor interpolator 2501 is illustrated in flowchart form in FIGS. 26 and 27. All other algorithmic components of speech synthesizer 2500 and their structural relationships are identical to those of speech synthesizer 1700. As in speech synthesizer 1700, data path 2522 (which is used to transmit time-scale modification factor ρ k ) may be omitted if only pitch-scale modification is desired, and modification may be implemented with ρ k =1 for all k.
FIG. 28 illustrates a synthesizer embodiment of the present invention appropriate for the synthesis and modification of pitched musical tone signals. Music synthesizer 2800 of FIG. 28 responds to stored encoded quasi-harmonic sinusoidal model parameters previously determined by music signal analysis in order to produce a synthetic facsimile of the original analog signal or alternately synthetic speech advantageously modified in time- and/or frequency-scale. Parameter decoder 2802 responds to encoded parameters retrieved from storage element 2801 via path 2820 in a manner similar to parameter encoder 1702 to produce the time-varying gain sequence σ n! of Equation 8 (if calculated in analysis) and the fundamental frequency estimate ω o k , quasi-harmonic model amplitudes {A j k }, differential frequencies {Δ j k } and phases {φ j k } used to generate a synthetic contribution according to Equation 45.
DFT assignment block 2803 responds to the fundamental frequency received via path 2821, the sets of quasi-harmonic model amplitudes, differential frequencies and phases received via paths 2822, 2823 and 2824 respectively, frequency-scale modification factor β k and time-scale modification factor ρ k received via paths 2825 and 2826, respectively, to produce a sequence Z i! which may be used to construct a modified synthetic contribution using an FFT algorithm. The algorithm used in this block is identical to that of DFT assignment block 1704 of FIG. 17, with the following exception: The purpose of the excitation pulse constraint algorithm used to calculate time shifts δ k and δ k+1 in DFT assignment block 1704 is that the algorithm is relatively insensitive to errors in fundamental frequency estimation resulting in an estimate which is the actual fundamental multiplied or divided by an integer factor.
However, for the case of pitched musical tones, such considerations are irrelevant since the fundamental frequency is approximately known a priori. Therefore, a simpler constraint may be invoked to determine appropriate time shifts. Specifically, denoting the phase terms of the sinusoids in Equation 56 by Φ j k n! and Φ j k+1 n! respectively, where ##EQU56## and denoting the unmodified phase terms from Equation 45 as φ j k n! and φ j k+1 n!, a reasonable contraint on the phase behavior of corresponding components from each synthetic contribution is to require that the differential between the unmodified phase terms at the center of the unmodified synthesis frame match the differential between the modified phase terms at the modified frame center. Formally, this requirement is given by
Φ.sub.j.sup.k+1 -ρ.sub.k N.sub.s /2!-Φ.sub.j.sup.k ρ.sub.k N.sub.s /2!=Φ.sub.j.sup.k+1 -N.sub.s /2!-Φ.sub.j.sup.k N.sub.s /2!, for all j. (93)
Solving this equation for δ k+1 using the phase functions just defined yields the recursion ##EQU57## Note that there is no dependence on j in this recursion, verifying that δ k+1 is a global time shift that needs to be calculated only once per frame. Furthermore, there is no dependence on the pitch onset time estimate τ p k as in DFT assignment block 1704; therefore, pitch onset time estimation as in speech synthesizer 1700 is not required for music synthesizer 2800. All other algorithmic components of music synthesizer 2800 and their structural relationships are identical to those of speech synthesizer 1700. As in speech synthesizer 1700, if only time-scale modification is desired, data path 2825 may be omitted, and the modification algorithms described may be implemented with β k =1 for all k. Likewise, if only frequency-scale modification is desired, then data path 2826 may be omitted, and the modification algorithms described may be implemented with ρ k =1 for all k.
A second version of a music synthesizer capable of performing time- and pitch-scale modification on previously analyzed musical tone signals is illustrated in FIG. 29. Music synthesizer 2900 operates identically to speech synthesizer 2500, with the exception that the time shift parameters used in modification synthesis are calculated according to Equation 94. As in speech synthesizer 2500, data path 2921 (which is used to transmit time-scale modification factor ρ k ) may be omitted if only pitch-scale modification is desired, and modification may be implemented with ρ k =1 for all k.
The architecture of a possible implementation of an audio analysis/synthesis system using a general-purpose digital signal processing microprocessor is illustrated in FIG. 30. It should be noted that this implementation is only one of many alternative embodiments that will be readily apparent to those skilled in the art. For example, certain subgroups of the algorithmic components of the various systems may be implemented in parallel using application-specific IC's (ASIC's), field-programmable gate arrays (FPGA's), standard IC's, or discrete components. | A method and apparatus for the automatic analysis, synthesis and modification of audio signals, based on an overlap-add sinusoidal model, is disclosed. Automatic analysis of amplitude, frequency and phase parameters of the model is achieved using an analysis-by-synthesis procedure which incorporates successive approximation, yielding synthetic waveforms which are very good approximations to the original waveforms and are perceptually identical to the original sounds. A generalized overlap-add sinusoidal model is introduced which can modify audio signals without objectionable artifacts. In addition, a new approach to pitch-scale modification allows for the use of arbitrary spectral envelope estimates and addresses the problems of high-frequency loss and noise amplification encountered with prior art methods. The overlap-add synthesis method provides the ability to synthesize sounds with computational efficiency rivaling that of synthesis using the discrete short-time Fourier transform (DSTFT) while eliminating the modification artifacts associated with that method. | 6 |
CROSS-REFERENCE TO A RELATED APPLICATION
This application is a National Phase Patent Application of International Patent Application Number PCT/EP2007/000153, filed on Jan. 3, 2007, which claims priority of International Patent Application Number PCT/DE2006/000014, filed on Jan. 4, 2006, and German Patent Application Number 10 2006 031 757.2, filed on Jul. 4, 2006.
BACKGROUND
The invention relates to a method for automatically correcting frame faults in video assist frames of a video assist system, and to an apparatus for carrying out the method.
U.S. Pat. No. 4,928,171 discloses a video assist system for a motion-picture camera, in which a video image sensor is arranged in an optical beam path of the motion-picture camera, which is interrupted periodically depending on the frame capture frequency of the motion-picture camera. A video assist system of this type serves to generate a video image in parallel with the exposure of film frames of the motion-picture film, which video image on the one hand enables image viewing independently of looking into the camera viewfinder during film capture and on the other hand facilitates the postprocessing of the exposed motion-picture film on the basis of the recorded video sequences.
For this purpose, part of the capture beam path of the motion-picture camera is branched off into a video beam path and directed to the video image sensor of the video assist system or a video camera. In this case, the camera lens of the motion-picture camera projects a frame in the image plane of the motion-picture film, which is moved intermittently for example at a film transport rate of 24 frames per second, if a rotating mirror diaphragm arranged in the capture beam path of the motion-picture camera downstream of the camera lens, with a diaphragm aperture sector, releases the capture beam path during the exposure of a film frame. In the time in which the motion-picture film is transported further by a film frame division, the diaphragm mirror sector of the rotating mirror diaphragm conceals the capture beam path to the image plane and directs the film frame onto the plane of a ground glass screen or fiber plate, from which the image that arises there is imaged on the video image sensor via a video assist lens.
The video image sensor integrates the light of the video beam path that falls onto its light-sensitive layer. The integrated signals are periodically read out from the video image sensor and represented as video output signals on a video monitor or stored on a suitable storage medium.
Situated between the ground glass screen or fiber plate and the video assist lens is at least one further beam splitter which branches off the image of the ground glass screen to an eyepiece via which a cameraman can view the film frame on the ground glass screen. Via a further beam splitter, a possibly illuminated format depiction can be imaged on the ground glass screen, which makes it easier for the cameraman to identify the frame center and the frame limits of the exposed film frame primarily in the dark.
The ground glass screens used for visually assessing an image or motif to be captured and for imaging the video assist frames are frosted either by a grinding process or in a chemical etching process, while fiber plates are produced from a bundle of individual light-guiding fibers that are oriented parallel. Both a ground glass screen and a fiber plate have a structure, however, which is disturbing particularly in the case of small-format frames such as are customary when capturing films. Although these structures can be reduced in the case of a ground glass screen by using a particularly fine abrasive grain during the grinding process, the ground glass screen becomes too transparent as a result, whereby the assessment of the optimum focus setting becomes impossible and the image brightness becomes nonuniform. The same disadvantages occur in the case of ground glass screens which are coated with a transparent lacquer in order to reduce the granularity on their matt surface.
Fiber plates have the advantage of a ground glass screen that the structure is smaller, but they are more expensive than ground glass screens and, particularly at relatively small apertures of the imaging camera lens, reveal a regular, usually honeycomb-shaped, structure that disturbs the artistic assessment of the image or motif. In this case, the structures of the ground glass screen or fiber plate are discernible all the more clearly, the more the camera lens is stopped down.
In order to improve the image quality of an image imaged on a ground glass screen or fiber plate, it is known from DE 100 20 307 to connect the ground glass screen or fiber plate to a drive device which moves the ground glass screen or fiber plate in oscillatory fashion at a frequency lying significantly above the temporal resolution capability of the eyes at approximately 60 hertz. With the aid of such an arrangement, although the appearance of the granularity and the honeycomb-shaped structure can be prevented or at least significantly reduced, the mechanical movement of the ground glass screen or fiber plate can be realized only with considerable outlay within a motion-picture camera and is also unable to solve the problem of optical vignetting explained below.
Before the video beam path branched off from the capture beam path reaches the video image sensor, the beam path passes firstly through the camera lens and then through the video assist lens. If there were no ground glass screen present between the two lenses, then it would be necessary, in order to avoid a keyhole effect, in which a decrease in brightness toward the edge of the video assist frame, that is to say optical vignetting, occurs, to meet the condition stipulating that the exit pupil of the camera lens lies in the entrance pupil of the video assist lens and said entrance pupil is smaller than the exit pupil of the camera lens. This condition cannot be met in practise, however, because there are a large number of camera lenses from the same or different manufacturers and the exit pupils of the respective camera lenses lie at different locations. One major reason for this is that the pupil position of a camera lens is irrelevant to the latter's essential task of imaging a capture object on the motion-picture film.
However, even when a ground glass screen or fiber plate is arranged between the camera lens and the video assist lens, optical vignetting or a brightness decrease toward the edge of the video assist frame occurs because the ground glass screen does not fully compensate for the different pupil positions between the camera lens and the video assist lens. Only an ideal ground glass screen behaving like a Lambertian emitter, whose luminance is constant in all directions and thus forms an ideal diffusely emitting area, would be able to compensate for the different pupil positions between the camera lens and the video assist lens and thus fully eliminate the keyhole effect. In this case, however, light would be sent into all spatial segments and only a fraction would come into the entrance pupil of the video assist or the eyepiece at the optical viewfinder, whereby a very dark image would arise there.
A further component-dictated frame fault in the generation of video assist frames by means of a video assist system is caused by the inherent noise of the video image sensor comprising a semiconductor component and occurs in or at different locations or pixels of the video assist frame in the case of successive video frames.
SUMMARY
It is an object of the present invention to specify a method for automatically correcting frame faults of the type mentioned in the introduction which eliminates or minimizes ground glass screen-based frame faults without restriction in the selection of parts or components of the motion-picture camera, the camera accessories or the video assist system and without additional hardware outlay.
The method according to an exemplary embodiment of the invention reduces or eliminates ground glass screen structures, on the one hand, and on the other hand obtains a uniformly bright video assist frame over the entire frame area without this imposing particular demands on the quality of the ground glass screen, type and quality of the camera lens or of the video assist lens or an additional hardware outlay being required there.
The exemplary solution according to an exemplary embodiment of the invention is based on the fault analysis that the ground glass screen or fiber plate structure visible on the video assist frame can be attributed to the fact that the ground glass screen or fiber plate superimposes on the capture frame a discrete bright/dark pattern similar to a “fixed pattern noise”, as is known from the field of semiconductor image sensors. This structure is stationary, the ratio of disturbance signal to noise signal depending on the aperture of the camera lens, such that the ground glass screen or fiber plate structure is hardly discernible in the case of a large diaphragm aperture of the camera lens, while when the camera lens is stopped down, that is to say in the case of a small diaphragm aperture, the capture beams fall onto the ground glass screen or fiber plate in a very much more parallel fashion, such that the structures of said screen or plate have a greater and greater effect.
By contrast, the vignetting or keyhole effect depends on the following factors:
1. on the video assist lens used; 2. on the chosen diaphragm aperture of the video assist lens; 3. on the camera lens used; 4. on the chosen diaphragm aperture of the camera lens.
Since the video assist lens used for the video assist system respectively employed is known, only points 2 to 4 remain as influencing variables for the vignetting or keyhole effect.
According to an exemplary embodiment of the invention, both problems are solved by calibrating the video assist system before film frames are captured, by capturing a homochromatic, unstructured and uniformly illuminated background, for example a neutral grey, uniformly illuminated sheet of paper, for different diaphragm apertures of the camera lens. During frame capture, the respective settings of the camera lens, in particular the diaphragm apertures of the camera lens, are fed to a controller controlling the calibration and, having been assigned to the frame capture instances, are stored in a frame store. After the calibration of the video assist system, an inverted image of the stored video assist calibration frames is superimposed on the video assist frames branched off from the capture beam path in a manner dependent on the diaphragm aperture of the camera lens and the “fixed pattern noise” of the ground glass screen structure is thereby removed.
The same calibration steps are also used for eliminating the vignetting or keyhole effect, parameters 2 to 4 mentioned above additionally being taken into account. The brightness ratios measured during the calibration on the individual video assist frames produce a set of curves with parameters 2 to 4 mentioned, which are used to calculate correction values pixel by pixel.
In order to separate the influence of the ground glass screen structure from the influence of vignetting in the frame faults that occur and additionally also to take account of the unavoidable inherent noise of the video image sensor, the solution according to the invention is based on the following consideration.
The ground glass screen structure represents a local disturbance in a manner similar to the randomly occurring inherent noise that changes from frame to frame, while vignetting is a curve which goes over the entire frame and on which the ground glass screen structure is superimposed as a higher frequency. In order to eliminate the high-frequency components of the ground glass screen structure, correction of the vignetting is achieved by averaging at a predetermined location of the video assist frames over a specific number of pixels, for example over a pixel group of 10 times 10 pixels. For compensation of the ground glass screen structure, once again an array or a pixel group of 10 times 10 pixels, for example, is selected, the average value of said pixel group is determined and a correction factor is determined for each pixel from the latter's deviations from the average value.
In order to correct the randomly occurring inherent noise, by contrast, with unchanged setting parameters of the camera lens and of the video assist lens, an average value of the brightness over a plurality of video assist frames is determined and it is assigned to the individual pixels of the video assist frames that are subsequently branched off from the film capture beam path.
Specifically, the following steps are carried out in order to eliminate or in order to reduce the ground glass screen-based frame faults, said steps being based on the basic method for automatically correcting frame faults in video assist frames of a video assist system in which the video assist system is calibrated by capturing at least one video assist frame of a single-colored, unstructured and uniformly illuminated, flat capture object for a predefined diaphragm aperture of the camera lens and storing it as a video assist calibration frame in a frame store, and the stored and inverted video assist calibration frame is superimposed on the video assist frames captured after the calibration.
Since the calibration cannot be carried out once for any video assist systems, because the ground glass screen structure depends on the ground glass screen respectively used (the designation “ground glass screen” and “ground glass screen structure” hereinafter also includes “fiber plate” and “fiber plate structure”) and is an individual structure of said ground glass screen and, moreover, the positioning of the video image sensor can be set in relation to the ground glass screen used, the calibration must be repeated whenever the ground glass screen is exchanged or the position of the video image sensor with respect to the ground glass screen is altered. In a practical embodiment, therefore, depending on the measurement system used, a calibration frame or a plurality of calibration frames is or are stored upon initiation of the user and the corresponding correction factors are determined, wherein the respective calibration operation can be carried out very rapidly.
During calibration it was ascertained that the ground glass screen structure stands out with respect to the inherent noise of the video image sensor when the camera lens is stopped down, that is to say in the case of small diaphragm apertures of the camera lens, in which case, when viewing individual frames, the inherent noise has a similar effect to the frame faults caused by the ground glass screen structure. In order to make the inherent noise distinguishable from the ground glass screen structure despite the small influence of said noise on the occurrence of frame faults in video assist frames, rather than taking account of just one frame for a predefined diaphragm aperture of the camera lens during calibration, a plurality of frames are taken into account. Since the inherent noise is distributed randomly from frame to frame in the video assist frames, while the ground glass screen structure is positionally invariable in accordance with the individual construction of the ground glass screen, a video assist frame averaged over a plurality of individual frames takes into account exclusively the ground glass screen structure and not the ground glass screen structure plus the inherent noise.
Furthermore, in order to correct the ground glass screen structure, a plurality of video assist calibration frames are captured for different settings of the camera lens and stored in conjunction with the respective lens setting and, depending on the respective setting of the camera lens, a stored and inverted video assist calibration frame assigned to said setting of the camera lens is superimposed on the video assist frames captured after the calibration.
According to a further exemplary feature of the invention, what are suitable as different settings of the camera lens are different diaphragm apertures of the camera lens which are used in capturing a plurality of video assist calibration frames for the calibration of the video assist system. The video assist calibration frames are stored in conjunction with the respective diaphragm aperture of the camera lens and, depending on the respective diaphragm aperture of the camera lens, are superimposed as inverted video assist calibration frame on the video assist frames captured after the calibration.
In order to correct the vignetting effect, a plurality of video assist calibration frames are captured using different camera lenses, different diaphragm apertures of the camera lenses and different diaphragm apertures of a video assist lens and the brightness values of a plurality of areas of the video assist calibration frames depending on the camera lenses used, the different diaphragm apertures of the camera lenses and the different diaphragm apertures of the video assist lens are stored.
By contrast, in order to eliminate or reduce the inherent noise of the video image sensor, the brightness values of the pixels of a plurality of video assist calibration frames captured using the same camera lens are captured with the setting of the camera lens, in particular the diaphragm aperture of the camera lens, remaining constant and the setting of the diaphragm aperture of the video assist lens remaining constant and an average value of the brightness of all the pixels of the captured video assist calibration frames is formed, which is assigned to the individual pixels of the video assist frames captured after the calibration.
In practise, in order to filter out the ground glass screen structure from the video assist frames, brightness values of the individual pixels of a video assist calibration frame are stored together with the address of the individual pixels in a frame store, the stored brightness values of the pixels of a pixel group are used to form an average value of the brightness of said pixel group, a correction factor is calculated from the deviation of the brightness values of individual pixels from the average value of the brightness of the pixel group, and the brightness values of the pixels of the video assist frames captured after the calibration are combined with the correction factor and output as corrected pixel brightness values to a display or further processing unit.
In this case, in order to determine the correction factors, the brightness values of the individual pixels of a plurality of video assist calibration frames are captured for different settings of the camera lens and are stored in conjunction with the respective setting of the camera lens and the assigned addresses of the individual pixels in the frame store, an average value of the brightness of a predefined pixel group is formed, a correction factor
V ME =I PG /I N
is determined for each individual pixel for the respective setting of the camera lens, where I PG is the average value of the brightness of the predefined pixel group and I N is the brightness value of each individual pixel, and the individual pixels of the video assist frames captured after the calibration are multiplied by the correction factor V ME .
In particular, the brightness values of the individual pixels of a plurality of video assist calibration frames are captured for different diaphragm apertures of the camera lens and are stored in conjunction with the respective diaphragm aperture or F-number and the assigned addresses of the individual pixels in the frame store, an average value of the brightness of a predefined pixel group is formed, a correction factor
V MB =I PG /I N
is determined for each individual pixel for the respective diaphragm aperture or F-number of the camera lens, where I PG is the average value of the brightness of the predefined pixel group and I N is the brightness value of each individual pixel, and the individual pixels of the video assist frames captured after the calibration are multiplied by the correction factor V MB .
Since there is no variation in the brightness changes—attributable to the ground glass screen structure—of the individual pixels of the video assist frames on account of the ground glass screen individually used, but rather only in the brightness amplitude thereof, alternatively for approximate determination of the correction factors the brightness values of the pixels of a video assist calibration frame can be captured for the smallest possible diaphragm or largest possible F-number of the camera lens and can be stored in conjunction with the respective diaphragm aperture or F-number and the assigned addresses of the individual pixels in the frame store, a correction factor
V M =V MA *C*BZ or V M =V MA *C*BZ 2
can be determined for each individual pixel, where V MA is the correction factor for each individual pixel for maximum stopping down of the camera lens, C is a constant dependent on the video assist system, and BZ is the F-number, and the individual pixels of the video assist frames captured after the calibration can be multiplied by the correction factor V M .
In this determination of the correction factors which simplifies the calibration, it is necessary to capture a correction frame of the video assist frame, that is to say a video assist calibration frame, and to determine the correction factor that can be allocated to each pixel, only once for a minimum possible diaphragm aperture of the camera lens, while all the other correction factors for the individual pixels of the video assist frames can be approximated mathematically.
A cross check of this approximation taking account of the formula mentioned above reveals that in the case of a large diaphragm aperture, that is to say for example in the case of an F-number of 2, the disturbances caused by the ground glass screen structure hardly have any effect because the influence of the correction factor is also small, while in the case of a large F-number of 32, for example, that is to say in the case of a small diaphragm aperture of the camera lens, the ground glass screen structure has a very great effect, which leads to a very high influence of the correction factors allocated to these diaphragm apertures.
Both the precise and the approximated determination of the correction factors can be used for correcting the ground glass screen structure only when the brightness difference between adjacent pixels of the video assist frames acquired does not exceed a predefined magnitude or a predefined percentage deviation, because even ground glass screens having coarse ground glass screen structures do not have an abrupt change in the brightness structures of adjacent pixels. If the brightness difference between adjacent pixels of the captured video assist calibration frames becomes too large, then it must be assumed that a format depiction is involved at these locations, said format depiction indicating the contours of the captured camera frame to the cameraman. No correction factor is determined at these locations of the video assist calibration frames, rather a correction factor equal to one is stored for the relevant pixels of the video assist calibration frame.
Therefore, an upper limit of 50% for a deviation of the brightness difference between adjacent pixels of a video assist calibration frame is defined as a criterion for the capture of the video assist calibration frames, that is to say that in the case of a larger deviation the correction factor “one” is stored for the relevant pixels.
Alternatively, it is possible to predefine a magnitude for the brightness deviation for which, upon being reached or exceeded, the correction factors “one” are stored for the relevant pixels of the video assist calibration frame.
Accordingly, the difference between the brightness values of adjacent pixels or pixel groups is determined and only those pixels for which the deviation of the brightness values is less than a predefined value are multiplied by a correction factor, or only those pixels for which the deviation of the brightness values of adjacent pixels is less than or equal to 50% are multiplied by a correction factor.
In order to correct the vignetting effect, during the calibration according to the basic method in accordance with the features of claim 1 taking account of the additional parameters of the video assist lens respectively used, the chosen diaphragm aperture of the video assist lens, the camera lens used and the chosen diaphragm aperture of the camera lens, the brightness values of a plurality of pixel groups of the video assist calibration frame or of the video assist calibration frames are captured for different camera lenses, different settings of the diaphragm aperture of the camera lens and different settings of the diaphragm aperture of the video assist lens and are stored together with the indication of the respective camera lens, the settings of the diaphragm aperture of the camera lens, the settings of the diaphragm apertures of the video assist lens and an addressing of the pixel groups in the frame store, in that a vignetting correction factor
V v =IG MAX /IG N
is determined for each pixel group and stored, where IG MAX is the brightness of the brightest pixel in the frame center of a video assist calibration frame and IG N is the brightness value of the relevant pixel group. The brightness values of the pixels of the video image sensor of the video assist system for the video assist frames captured after the calibration, depending on the camera lens used, the setting of the diaphragm aperture of the camera lens and the setting of the diaphragm aperture of the video assist lens are combined with the correction factor V v .
In practise, the requisite sets of curves of the parameters or correction tables can be provided by the camera manufacturer, which necessitates suitable measuring devices but makes the sets of curves or correction tables determined usable for any motion-picture camera of the same type if the corresponding correction factors are determined in calibration measurement series and are provided for each camera user.
The correction tables or sets of curves of the abovementioned parameters that have been determined and defined in this way are transferred into a frame store of the video assist system, which can be done both during initial production and in the context of software updates. In the case of software updates, the relevant data can be made available over the Internet, for example, such that the camera user can download the respective up-to-date correction tables and store them in the video assist system.
In order to separate the influence of the ground glass screen structure, which represents a local disturbance like the inherent noise of the video image sensor, from the influence of vignetting, which can be represented as a curve which goes over the entire video image and on which the ground glass screen structure is superimposed with a higher frequency, in order to eliminate the high-frequency components of the ground glass screen structure, correction of the vignetting effect is achieved by averaging over a specific number of pixels, for example over a pixel group of 10 times 10 pixels, at a predetermined location of the video assist calibration frames. For the compensation of the ground glass screen structure, once again an array for a pixel group of 10 times 10 pixels, for example, is selected, the average value of said pixel group is determined and then the correction factors are determined for each pixel of the video assist calibration frames from the deviations from the average values.
This gives rise, for each pixel of a video assist calibration frame depending on the ground glass screen used and on the respective F-number or diaphragm aperture of the camera lens, to a correction factor
V MB =I PG 100 /I N
for each individual pixel for a predefined F-number, where I PG 100 indicates the average value over the pixel group of 10×10 equals 100 pixels, for example, and I N is the brightness value of each individual pixel.
This results overall, for each pixel of a video assist calibration frame, in the relationship
U CORR =U MEAS *V MB *V V
where U CORR is the corrected brightness value of a pixel, U MEAS is the measured brightness value of a pixel, V MB is the correction factor dependent on the ground glass screen used and on the respective F-number or diaphragm aperture of the camera lens, and V V is the vignetting correction factor dependent on the respective camera lens, the setting of the diaphragm aperture of the camera lens and the setting of the diaphragm aperture of the video assist lens.
Using the abovementioned simplified formula for the correction of the ground glass screen structure with the smallest possible diaphragm aperture, the relation
U CORR =U MEAS *V V
can be used.
The method according to the invention for automatically correcting frame faults in a video assist frames of a video assist system can be used at various points in the generation of the video assist frame.
In a first exemplary variant, the video frames generated by the video assist system are converted into a correctly colored video frame and the frequency compensation between the frame capture frequency of the motion-picture camera and the video standard of the video assist system is performed. This is followed by acquiring the video assist calibration frames for determining and storing the correction factors and, after the calibration, carrying out multiplication by the correction values of the captured brightness values of the individual pixels.
Accordingly, an apparatus for carrying out the method comprises a video assist system connected to a motion-picture capture and containing a video assist lens, which is directed at a ground glass screen arranged in a beam path tapped off from the film capture beam path of the motion-picture camera, a video image sensor and a controller, to which setting and status data of a camera lens arranged in the film capture beam path of the motion-picture camera are applied and which is connected to a frame store. The output of the video image sensor of the video assist system is connected to the input of an image or color conditioning, the output of which is connected via an A/D converter both to the frame store and to a first input of a multiplier, the second input of which is connected to the output of an amplifier connected to the output of the frame store and the output of which is connected to the input of a D/A converter.
In one exemplary variant, the raw data of the video image sensor are stored and the correction is carried out in the film capture operating mode. The frequency compensation likewise takes place at this point in the image processing, while the conversion of the colors and the conditioning of the video signal take place subsequently.
Accordingly, in this variant, the output of the video image sensor is connected via an A/D converter both to the frame store and to a first input of a multiplier, the second input of which is connected to the output of an amplifier connected to the output of the frame store and the output of which is connected via a D/A converter to the input of an image or color conditioning.
An exemplary advantageous embodiment of the apparatus according to an exemplary embodiment of the invention for carrying out the method for automatically correcting frame faults in video assist frames of a video assist system is characterized in that the storage of the correction factors for correcting the ground glass screen structure is effected separately from the storage of the correction factors of the vignetting effect in other address areas of a frame store since the respective correction factors are determined in different, mutually separate calibration processes and at different times.
The method according to an exemplary embodiment of the invention and the apparatus according to an exemplary embodiment of the invention are suitable both for analog and for digital video assist systems, wherein the parameters of the camera lens that are required for determining the correction factors in the calibration process and for taking them into account in the real film capture operating mode and the settings of said camera lens are obtained in accordance with U.S. Pat. No. 6,148,151 A, for example, which provide inter alia information about the lens type and the respective diaphragm aperture.
BRIEF DESCRIPTION OF THE DRAWINGS
Further details of the invention and the considerations on which the invention is based will be explained in more detail on the basis of a plurality of exemplary embodiments illustrated in the figures, in which:
FIG. 1 shows a schematic block diagram of the optical functional elements and of the beam path of a motion-picture camera with an analog video assist system.
FIG. 2 shows a schematic block diagram of the optical functional elements and of the beam path of a motion-picture camera with a digital video assist system.
FIG. 3 shows a block diagram of a video assist system with image or color conditioning before determining and taking account of correction factors for correcting ground glass screen-based frame faults.
FIG. 4 shows a block diagram of a video assist system with storage of raw data of the video image sensor and performance of the image or color conditioning after determining or taking account of correction factors for correcting the inherent noise of the video image sensor, the ground glass screen structure and the vignetting effect.
FIG. 5 shows the profile of the brightness values of the pixels of an upper or lower frame line—reaching into the frame corners—of a video image sensor.
FIG. 6 shows an enlarged illustration of the brightness values of the first 50 pixels of the brightness distribution in accordance with FIG. 5 .
FIG. 7 shows an illustration of the brightness distribution—averaged over 20 pixels, of the first 50 pixels in accordance with FIG. 6 .
FIG. 8 shows an illustration of a correction of the vignetting effect by means of a brightness distribution—averaged over 20 pixels in each case—of the pixels of an upper or lower line in accordance with FIGS. 5 and 7 .
DETAILED DESCRIPTION
The optical systems of a motion-picture camera 1 with a video assist system 2 , 3 which are illustrated schematically in FIGS. 1 and 2 show a camera lens 10 , through which a capture beam path A enters into the motion-picture camera 1 and impinges on a rotating mirror diaphragm 11 , which is composed of a circular-disc-shaped mirror surface and a diaphragm adjusting blade that is arranged coaxially with respect to the circular-disc-shaped mirror surface and is adjustable with respect to the mirror surface, such that a variable mirror surface or a diaphragm aperture angle of 0° to 180° of the rotating mirror diaphragm 11 can be set. If the capture beam path A impinges on the aperture or bright sector of the rotating mirror diaphragm 11 , then it passes to a film plane 12 , which is defined by an image window at which a motion-picture film is guided along in a film channel. During the transport of the motion-picture film, the image window or the film plane 12 is covered by the circular-disc-shaped mirror surface of the rotating mirror diaphragm 11 and the capture beam path A is deflected as video beam path V onto a ground glass screen 13 , on which a frame corresponding to the film frame on the motion-picture film is imaged. The capture frame imaged on the ground glass screen 13 can be viewed by a viewer 8 via a first beam splitter 14 and an eyepiece 17 and be captured by an analog video assist system 2 in accordance with FIG. 1 or a digital video assist system 3 in accordance with FIG. 2 .
A second beam splitter 16 , which is arranged in the beam path between the ground glass screen 13 and the first beam splitter 14 , reflects a frame field marking 15 or ground glass screen illumination onto the plane of the ground glass screen 13 , such that the viewer 8 can view the capture frame in conjunction with frame field boundaries or in brightened fashion.
The video beam path V passing through the first beam splitter 14 to the analog or digital video assist system 2 or 3 is imaged onto the area of a video image sensor 5 by means of a video assist lens 4 , which sensor converts the optical capture frame into video image signals.
In the case of the analog video assist system 2 illustrated schematically in FIG. 1 , the video image sensor 5 is connected to a video assist electronic unit 6 , which is constructed in accordance with the block diagram in FIGS. 3 and 4 and receives data and setting signals of the camera lens 10 via a signal line 18 or alternatively via a radio transmission network or the like.
The digital video assist system 3 illustrated in FIG. 2 is composed of a sensor unit 31 , which contains the video assist lens 4 and the video image sensor 5 , and a processing computer 32 , which contains a digital video assist electronic unit 7 , which can likewise be constructed analogously to the block diagrams of FIG. 4 or 5 .
The video assist electronic unit 6 of the analog video assist system 2 and the video assist electronic unit 7 of the digital video assist system, respectively, are connected, besides the illustrated connection to the camera lens 10 , via further signal lines to the camera controller and external control devices via which the video assist electronic unit 6 or 7 , receives a diaphragm index signal from the motion-picture camera 1 , said signal corresponding to the position or the diaphragm aperture angle of the rotating mirror diaphragm 11 with respect to the capture beam path A and corresponding to the respective exposure conditions of the video beam path V and thus to the exposure conditions on the video image sensor 5 , camera status data and camera status signals or metadata, such as, for example, the film transport speed, information about the motion-picture film consumption, the charge state of the rechargeable battery, further information about the camera lens 10 in the form of the zoom and focus settings and the like and also time code signals.
On the output side, the video assist systems 2 , 3 output the analog or digital assist signals generated from the image signals and also capture, control and/or status signals of the motion-picture camera 1 as metadata to a processing unit and also camera control signals to an electronic control unit of the motion-picture camera 1 for the setting of camera and accessory desired values and, through the connection of a monitor, enable viewing of the assist frames composed of the analog or digital assist signals directly at the video assist system 2 , 3 and thus at or in direct proximity to the motion-picture camera 1 .
The data and setting signals of the camera lens 10 comprise a coding of the camera lens 10 respectively used and also the setting of predefinable parameters of the camera lens 10 , in particular of the iris diaphragm aperture of the camera lens 10 . In order to eliminate the vignetting effect explained below, a signal indicating the diaphragm aperture of the video assist lens 4 is applied to the video assist electronic unit.
The block diagram—illustrated in FIG. 3 —of the video assist electronic unit 6 in accordance with FIG. 1 or 7 in accordance with FIG. 2 contains an image or color conditioning device 91 , which is connected to the output of the video image sensor 5 , which receives the capture frame imaged on the ground glass screen 13 via the video assist lens 4 and converts the optical image into video signals, an analog/digital (A/D) converter 92 , which is connected to the output of the image or color conditioning device 91 and the output of which is connected both via frame stores 93 , 94 and an amplifier 95 to a first input of a multiplier 96 and directly to a second input of the multiplier 96 , and also an output-side digital/analog (D/A) converter 97 , the output of which is connected to a processing unit described above, a monitor or the like.
In this embodiment, the video images generated by the video assist system are converted into a correctly colored video image, the frequency compensation between the frame capture frequency of the motion-picture camera and the video standard of the video assist system is performed, and this is followed by acquiring the video assist calibration frames for determining and storing the correction factors and, after the calibration, carrying out the subtraction of the correction values from the captured brightness values of the individual pixels.
Depending on the application or degree of equipment, the frame store 93 , 94 can be subdivided into a frame store 93 for correcting the ground glass screen structure 93 and a frame store 94 for correcting vignetting effects and is connected to a controller 90 , to which the additional signals and data of the camera lens 10 and of the video assist lens 5 are applied on the input side via signal lines 18 , 40 .
In an alternative embodiment, the video assist electronic unit can be constructed in accordance with the block diagram illustrated in FIG. 4 , which differs from the embodiment in accordance with FIG. 3 to the effect that the image or color conditioning device 91 is not inserted into the connection of the output of the video image sensor 5 to the input of the analog/digital converter 92 , but rather into the connection of the output of the digital/analog converter 97 to the output of the video assist electronic unit.
In this alternative embodiment, the raw data of the video image sensor are stored and the correction is carried out in the film capture operating mode. The frequency compensation likewise takes place at this point in the image processing, while the conversion of the colors and the conditioning of the video signal take place subsequently.
An explanation is given below of the function of the video assist electronic unit 6 illustrated in the block diagram in FIGS. 3 and 4 for the analog video assist system 2 or respectively 7 for the digital video assist system 3 with respect to eliminating or reducing ground glass screen-based frame faults.
In order—for eliminating ground glass screen-based frame faults, firstly to eliminate or filter out the unavoidable, randomly occurring inherent noise of the video image sensor that varies from video image to video image and from pixel to pixel, a plurality of video images are captured and average values of the brightness over the plurality of video images are determined. Said average values are subsequently used for a representation of the video images from which the inherent noise of the video image sensor has been eliminated.
The profile—illustrated in FIG. 5 —of the brightness values of the pixels of a frame line of the video image sensor in an upper or lower line reaching into the region of the frame corners is manifested for a video camera or a video assist system without inherent noise. It can be gathered from this illustration that a brightness profile that decreases continuously from the frame sensor to the frame sides is superimposed on the frame-dependent brightness fluctuations of the pixels. This vignetting effect is attributable to the type of camera lens used, the diaphragm aperture thereof and the type of video assist lens used and the diaphragm aperture thereof. If it is assumed that the video assist lens used with the video assist system used is known, the camera lens used, the diaphragm aperture thereof and the diaphragm aperture of the video assist lens remain as parameters.
The brightness fluctuations from pixel to pixel of a frame line that are illustrated in FIG. 5 are, however, not just attributable to the brightness fluctuations of the pixels of a capture frame, but rather also comprise frame faults caused by the ground glass screen structure.
FIG. 6 shows, in an enlarged illustration, the profile of the brightness of the first 50 pixels of the pixels of an upper or lower frame line that are illustrated in FIG. 5 and shows the extent of the brightness fluctuations in this quasi “zoomed” region of the brightness profile of the pixels of a frame line.
In order to separate the influence of the invariable ground glass screen structure, which is exclusively dependent on the ground glass screen, from the vignetting effect, which is dependent on the parameters referred to above, in accordance with FIG. 7 an average value of the brightness distribution is determined over a predefinable number of pixels, over 20 pixels of a frame line in the exemplary embodiment illustrated. In the case of the brightness distribution illustrated in FIG. 6 , the average values of the brightness values of the first 50 pixels of this frame line that are illustrated in FIG. 7 are produced.
As an alternative and for practical improvement of accuracy, it is possible to determine the average value of the brightness distribution over an area of, for example, 10×10 or 20×20 pixels.
If the averaging of the first 50 pixels of a frame line as illustrated in FIG. 7 is applied to the pixels of the entire frame line, then the averaging over in each case 20 pixels of the chosen frame line as illustrated in FIG. 8 is produced. This staircase-shaped curve indicates the correction factors for eliminating or reducing the vignetting effect. Brightness differences within a step of the curve illustrated in FIG. 8 which remain the same over an arbitrarily selectable multiplicity of video assist frames therefore indicate, taking account of the inherent noise, the brightness deviations which are attributable to the ground glass screen structure. Accordingly, the correction factors assigned to the individual pixels can take account of the frame faults attributable to the ground glass screen structure and output an image signal from which the ground glass screen-based frame faults on account of the ground glass screen structure and the vignetting effect have been eliminated. | A method for automatically correcting frame faults in video assist frames of a video assist system in a video beam path branched off from a capture beam path of a motion-picture camera, a ground glass screen being arranged in said video beam path, is provided. The video assist system is calibrated by capturing at least one video assist frame of a single-colored, unstructured and uniformly illuminated, flat capture object for a predefined diaphragm aperture of the camera lens and storing it as a video assist calibration frame in a frame store, wherein the stored and inverted video assist calibration frame is superimposed on the video assist frames captured after the calibration. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is directed at a system which senses the washing cycle steps of an automatic laundry washing machine and signals the controlled flow of one or more cleaning chemicals into the machine washing chamber.
2. The Prior Art
Most commercial laundry washing machines have a liquid chemical feed dispenser which injects fabric treating chemicals into the washer. Among such chemicals are alkali, detergent, bleach, souring agent and fabric softener. More than 90% of these dispensers are interfaced electrically with the internal controller of the washing machine.
There are two types of controls used in washing machines: one is called a non-programmable, and the other a programmable type. The non-programmable control has fixed wash formulas, set up by the machine manufacturer, which cannot be altered. Switching contacts ride on cams encased in the programmer that operates the various functions of the washer.
Programmable models are run by a chart or card which the installer of the chemical dispenser cuts to create a wash formula. Each cut in the chart or card causes a microswitch to open or close creating operation of a function of a wash formula.
A electrical signal from inside the washing machine internal controls, i.e. the program, is normally required to activate injection of a cleaning chemical. On most older washers and even some of the newer ones, locating and tying into these control circuits is not always easy. Also, once an installer has gone into the controls, there is a great risk that those internal controls are damaged or otherwise adversely affected.
Where an installer is not a representative of the washing machine manufacturer, there is also the further problem of voiding factory warranties. Manufacturers do not want unauthorized technicians tampering with the internal controls of their machine.
There have been a number of patents issued focusing upon the problem of delivering cleaning chemicals to the washer. U.S. Pat. No. 4,335,591 (Gillespie) reports use of separate sequence controllers connected to a line of multiple washers. Each of the controllers intercommunicates with every other one and operates a series of electromagnetic valves to deliver detergent and bleach based upon electronic energizing signals.
U.S. Pat. No. 3,982,666 and U.S. Pat. No. 3,881,328, both to Kleimola et al., disclose a detergent dispensing system for sequentially and automatically injecting detergents, fabric conditioners and other cleaning chemicals into a laundry washing machine. A signaling device synchronized with the washing machine cycle selectively actuates and deactuates solenoid-operated valves positioned upstream of Venturi-Aspirators assigned to each chemical line. Predetermined quantities of each liquid chemical can thereby be delivered at any desired point in the machine cycle.
Another automated laundry system is reported in U.S. Pat. No. 4,103,520 (Jarvis et al.). Here an injector having a plurality of liquid additive reservoirs and associated timed control valves selectively can inject liquid additives into the washer. An adaptor connected to both the washer and injector controls sequencing throughout the operating cycle of the washer. This adaptor establishes sequential program signals to the injector where the washer does not have a built-in programer.
Automatic dishwashing machines as described in U.S. Pat. No. 2,834,364 (Federighi et al ) have also been fitted with sensors to activate addition of cleaning chemicals. The patent describes a hot water feed pipe to which is connected a pressure switch When there is a drop in water pressure, the switch causes an electric valve to open which allows a quantity of liquid soap or detergent to flow into the washing tank.
Common to the aforementioned art is the requirement for invading the machine housing to connect into the programer controlling the dispenser system. Thus, there arises the problem of installation difficulty, equipment compatibility and, ultimately, voiding of machine warranties.
Accordingly, it is an object of the present invention to provide a system for dispensing laundry treating chemicals to an automatic washing machine without requiring the dispenser installer to invade the machine housing.
Another object of the present invention is to provide a system for dispensing laundry treating chemicals into ar automatic washing machine that is very simple to install and operate.
Another object of the present invention is to provide a system for delivering detergent, fabric softener, alkali, bleach and/or souring agent to an automatic washing machine for the laundering of fabrics.
Another object of the present invention is to provide a system for dispensing laundry treating chemicals into ar automatic washing machine which does not result in voiding machine manufacturer warranties.
Another object of the present invention is to provide a system for the delivery of laundry treating chemicals tc an automatic washing machine which is not limited by a washing sequence formula pre-programmed into the machine itself.
Still a further object of the present invention is to provide an apparatus for dispensing laundry treating chemicals into an automatic washing machine that operates to accomplish the objects as aforedescribed.
SUMMARY OF THE INVENTION
An apparatus for washing fabrics is provided including:
a washing device having:
a housing;
a wash chamber in said housing;
a hot and a cold water inlet conduit in said housing communicating with said chamber;
at least one laundry treating chemical inlet conduit in said housing communicating with said chamber; and
optionally, a wash program selector in said housing;
a hot water line outside said housing connecting a source of hot water to said hot water inlet conduit;
a cold water line outside said housing connecting a source of cold water to said cold water inlet conduit;
at least two sensing means for sensing a flow of water and converting a flow signal therefrom into an electronic impulse, a first of said means connected to and sensing a flow in said hot water line and a second of said means connected to and sensing a flow in said cold water line;
a plurality of pumps;
a control head receiving and storing said electronic impulses and comprising a program to selectively activate said plurality of pumps;
a plurality of laundry treating chemical supply, containers, one of said containers holding a detergent;
at least one conduit connecting said supply containers to said at least one laundry treating chemical inlet conduit, said pumps activating transfer of detergent through said connecting conduit; and
optionally, a means for communicating between said wash program selector and said control head.
BRIEF DESCRIPTION OF THE DRAWING
Various features and advantages of the present invention will more readily be apparent through the following description in conjunction with the accompanying drawings of which:
FIG. 1 is a diagrammatic plan view of the overall machine and dispenser system;
FIG. 2 is a broad schematic view of the electrical and fluid connections interconnecting the machine and dispenser system; and
FIG. 3 is a schematic view of the system with a more detailed illustration of the electrical wiring, switches and logic circuits.
DETAILED DESCRIPTION OF THE INVENTION
By reference to FIG. 1, the system is seen to include a washing machine (1) with wash chamber (2), hot and cold water (4,5) lines leading into the washer, water flow sensors (6,7) in each of the water lines, a control head (8), a series of pumps (9) and a series of laundry treating chemical supply containers (10). Each of these features will now be discussed in more detail.
Focus of this invention is to allow a chemical supplier representative to install the chemical dispensers (10) and their external control head (8) without connecting to electrical wiring of control timers inside the washing machine housing (11). Therefore, a critical aspect of the invention is placement of a water flow sensor (6, 7) within the water lines (4,5) leading into the washing machine housing. These sensors will be activated by the flow of water to set-off a mechanical or electrical switch, which in turn will send an electronic impulse tc the control head (8). Whenever there is any flow of water, the sensor will continuously emit the electronic impulse over the &time period of flow. Once the water flow has ceased the emitted electronic impulse will also cease.
A typical laundry wash sequence will include cycles where either hot or cold water will be required exclusively. For instance, the main wash step using detergent will normally involve a hot or warm water fill. On the other hand, a subsequent rinse cycle will normally exclusively utilize cold water. Therefore, it is necessary to monitor both the hot and the cold water lines separately to determine the stage of the washing sequence. It should be noted that not every water flow induced electronic impulse results in the triggering of a chemical delivery. Cycles such as certain of the rinses do not include injected chemicals. However, the electronic impulse must be registered by the control head to keep count and accurately track the washing sequence.
Flow sensors may be placed either directly in the water line or adjacent thereto. For instance, a butterfly rotating valve may be used within the water line. Alternatively, a non-invasive sensor may consist of a photo cell positioned around the outside of a transparent segment of the water delivering conduit. There may also be a combination of mechanical valve within the water line signaling a magnetic pick-up device surrounding the outside of the water conduit.
Within the context of the present invention, the term "hot" water refers to a temperature in the range of from about 100° F. to about 180° F., most preferably from about 120° F. to 140° F. Likewise, the term "cold" water encompasses a temperature range from about 40° F. to about 80° F., preferably between about 50° F. and 70° F.
Another highly important component of the present system is a control head (8). Within the control head is a stepping switch (22), dip switches (32), a reversing relay (50), pump relay (40), and programming relays (60).
Stepping switch (22) comprises a series of terminals (24) (shown in FIG. 3 as being 10 in number). Switch member (25) is movable from one terminal to the next in a semi-circular fashion step-wise, each step being actuated by a change in electronic impulse.
From the stepping switch terminal, the electronic impulse is transferred to one of a group of dip switches (32) which may either be in the "on" or "off" position dependent upon the particular wash program desired. Where a dip switch (32) is in the "on" position, the signal will pass to delivery instructing programming relays (60). A further series of electrical connections transmit signals from the relays (60) to activate the respective pumps (9) which then deliver cleaning chemicals into the wash chamber (2) of machine (1).
Some washing machines are user programmable. The programs are set by a chart or card upon which a formula sequence is cut. Each cut in the card or chart causes a microswitch to open or close creating occurrence of a certain function in the wash sequence. These programs operated by a program selector (3) can be interfaced through an electrical connection (12) with the chemical formula relays (60) of control head (8).
Operation of the system is best explained as follows. The washing machine will operate in the same manner as is normally done, whether the machine is user programmable or non-programmable. When the washer is started for a particular wash formula, an operator will activate a switch on formula box (3) that corresponds to the classification of wash being done. This box is normally located outside of and normally on the front of a machine. When the switch on the formula selector (3) is "on", contacts of the relays (60) corresponding to the program formula will close.
When water enters the machine (hot, cold or both), contacts of one or both the water flow sensors (6,7) will send an electronic impulse to stepping switch coil (22) of the control head (8). Stepping switch (22) through its switch member (25) will contact terminals (24) in sequence. Thereby will be electrically energized a wire leading from the terminal to a respective dip switch (32). Those dip switches in the "on" position will then further send a signal to the programming relays (60) which trigger pumps that dispense the appropriate cleaning chemical from supply containers (10). This sequence will be repeated every time water enters to fill the washer. Each time the stepping switch coil receives a new electronic impulse, the next terminal, running from (1) to (10), will energize.
An installer of the dispenser system will set the on/off functions of dip switches (32) to correspond t the formulas being used by the formula box. The "on" positions of the dip switch will allow voltage to pass through that switch to the common C terminal of the relay. This then allows the electronic impulse to go from the normally open (N.O.) contact of the relay, which is now in the closed position, that was closed when the formula switch on the formula box was turned on. The electronic impulse will then go from the normally open (N.O.) contact of the relay to the central pumping unit (40). Thereupon, the proper chemical feed pump will activate to inject a chemical into the washer.
When the last step of a wash formula is started, the feed pump for the last chemical will cause the stepping switch member (25) to return to the zero terminal position.
To start another wash formula, a transformer (44) is energized when the last pump turns on. Reset contacts in the stepping switch are closed, and the coil (42) of a reversing relay (50) are energized. Relay (50) will then switch back and forth from N.O. to N.C. moving the switch member (25) of the stepping switch (22) back to the zero position.
An external power source, not from the washing machine (1), should be used so the dispenser system can be powered from a standard outlet.
Advantageously, the control head should be able to program up to six formulas. A formula would be composed of a series of steps in an amount corresponding to a fill cycle of the wash chamber (2) with water. Typical formulas are illustrated below.
TABLE I______________________________________FormulasLight Cleaning Medium Cleaning Heavy CleaningFormula Formula Formula______________________________________Detergent/Bleach Water Flush Water FlushRinse Detergent Water FlushRinse Bleach AlkaliSoftener Rinse Detergent Rinse Rinse Softener Rinse Softener/Sour______________________________________
Any number of typical laundry treating chemicals may be employed with the present system. Invariably, the wash cycle will include feeding of a detergent to the wash solution in the laundry filled wash chamber. Examples of useful detergents are anionic, nonionic, cationic, zwitterionic and amphoteric surfactants. Among the most useful anionic surfactants are soap, alkylbenzene sulfonates, alkyl ether sulfates and alkyl sulfates. Useful nonionic surfactants include alkoxylated derivatives of fatty acids and fatty alcohols.
Normally, the last chemical to be added to a wash sequence is that of a fabric softener which normally is a quaternary ammonium compound. Typical of this class ar ditallow dimethyl ammonium methosulfate or chloride salts.
Other performance chemicals may be added and these can include alkali such as sodium carbonate, sodium hydroxide and sodium silicate. Bleach may also be included in one or more of the cycles. Normally, the bleach will be sodium hypochlorite but peroxygen bleaches may also be utilized when necessary. Souring agents, fluorescent brighteners, anti-redeposition agents, perfumes, enzymes and other fabric treating chemicals may be injected into the wash liquor. All of the aforementioned chemicals can either be delivered separately in separate cycles or can be delivered separately within a single cycle. Alternatively, several of the aforementioned chemicals can be combined within a single liquid product to be dispensed from a single supply container.
It is to be understood that the invention in its broader aspect is not limited to the specific elements shown and described above. Rather, the invention includes within the scope of the accompanying claims any departures made from such elements which do not sacrifice its chief advantages. | An apparatus for cleaning fabrics includes a washing machine having a housing, a wash chamber, hot and cold water inlet conduits in the housing leading to the chamber, and at least one laundry chemical inlet conduit. Water flow sensing means are placed in the hot and cold water lines, respectively, located outside of the housing. The flow of water generates a signal in the sensing means which then sends an electronic impulse to a control head having a program that stores and selectively activates a plurality of pumps. These pumps deliver laundry chemicals from supply containers into the wash chamber of the machine. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 11-268359, filed Sep. 22, 1999, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor memory, for example, a semiconductor memory to synchronize input of a command and write or read of data with an external clock, such as a synchronous DRAM.
In the case of semiconductor memory which synchronizes input of a command and write or read of data with an external clock, the operation of circuits in a chip is synchronized with some basic pulses, which are generated within the chip by using the external clock as a trigger. In such a semiconductor memory, an access time from input of read command to data output is determined by the number of pulses in the external synchronous clock. For example, in a synchronous DRAM, the number of the pulses in the external synchronous clock is called as CAS latency (CL) and it is important value for a specification. A column operation synchronous pulse, which is synchronized with the operation of the column system circuit within a chip, is generated at a timing to fill this value. Further, the timing of this column operation synchronous pulse is usually determined uniquely by the above CL. The same pulse can be used even if a column command represents “read” or “write”, since the pulse control is advantageously simplified when the column operation synchronous pulses of read and write are identical.
FIGS. 1 to 3 illustrate the above described conventional semiconductor memory, respectively. FIG. 1 is a block diagram showing extractively a circuit in reference to the control of a column system basic pulse in the synchronous DRAM. FIG. 2 is a circuit diagram showing a constitutional example of an input column address latch controller in the circuit shown in FIG. 1 . FIG. 3 is a circuit diagram showing a column pulse transfer controller in the circuit shown in FIG. 1 .
As shown in FIG. 1, a circuit in reference to the control of the column system basic pulse in the synchronous DRAM comprises an external clock input buffer 11 , pulse generators 12 - 1 , 12 - 2 , 13 - 1 , 13 - 2 , delay circuits 14 - 1 , 14 - 2 , a CAS input buffer 15 , a RAS input buffer 16 , a CS input buffer 17 , a decoder 18 , a decoder and latch circuit 19 , a WE input buffer 20 , an input column address latch controller 21 , address input buffers 22 - 1 , 22 - 2 (ADD 1 , ADD 2 ), address latches 23 - 1 , 23 - 2 , core buses 24 - 1 , 24 - 2 (addresses K 1 , K 2 ), a burst length counter 25 , a column pulse transfer controller 26 , a column bank controller 27 , a DQ buffer 28 , a data line 29 , an off chip driver 30 , an output pulse generator 31 , transfer gates 32 - 1 to 32 - 7 , 32 - 9 to 32 - 12 , a column address decoder 33 , a memory cell allay 34 and an inverter 35 or the like.
As shown in FIG. 2, the above column address latch controller 21 is composed of a NAND gate 41 , a transfer gate 42 and inverters 43 , 44 , 45 .
Further, as shown in FIG. 3, the above column pulse transfer controller 26 is composed of a NOR gate 51 , transfer gates 52 to 54 and inverters 55 to 60 . A signal CL 2 OPN controls the transfer gate 52 to open the transfer gate 52 when the CAS latency is 2 . A signal CL 3 OPN controls the transfer gate 53 to open the transfer gate 52 when the CAS latency is 3 .
In FIGS. 1 to 3 , in order to simplify the illustrations, it is shown that only one-sided MOS transistor gates of transfer gates 32 - 1 to 32 - 7 , 32 - 9 to 32 - 12 , 42 , 52 to 54 are provided with signals. However, other sided MOS transistor gates are provided with inverted ones of the above signals. Here, the transfer gates 32 - 1 to 32 - 7 , 32 - 9 to 32 - 12 , 42 , 52 to 54 are formed by connecting a current path of a P channel type MOS transistor and a current path of an N channel type MOS transistor in parallel.
In this example, two kinds of column system basic pulses are used for a column operation synchronization and a column address latch. These two kinds of column system basic pulses are activated at the same timing.
FIGS. 4 and 5 are timing charts for showing signal waveforms of the CL 2 and the CL 3 schematically. FIG. 4 shows a signal waveform in the case that the CL 2 , i.e., the CAS latency is 2 and FIG. 5 shows a signal waveform in the case that the CL 3 , i.e., the CAS latency is 3 , respectively.
As shown in FIG. 1, the external clock input buffer 11 is connected to two pulse generators 12 - 1 and 13 - 1 . As shown in the timing chart of FIG. 4, respective pulse generators 12 - 1 and 13 - 1 generate pulse signals Pa and Pb, which have different pulse widths each other, from leading edges of an external clock VCLK. These respective pulse generators 12 - 1 and 13 - 1 are connected to pulse generators 12 - 2 and 13 - 2 via delay circuits 14 - 1 and 14 - 2 , which are composed identically, respectively. These pulse generators 12 - 2 and 13 - 2 generate pulse signals Pa′ and Pb′ from edges of the above pulse signals Pa and Pb, respectively. The pulse generators 12 - 1 , 13 - 1 and 12 - 2 , 13 - 2 are identically composed. The pulse signals Pa′, Pb′ are obtained by shifting the pulse signals Pa, Pb for a certain period of time, respectively. In the present example, as described later, it is assumed that the pulse signals Pb, Pb′ are used for the column operation synchronous pules and the pulse signals Pa, Pa′ are mainly used for the column address latch pulse.
If the column access information is inputted from a command pin, a decoder 18 is connected to the CAS input buffer 15 , the RAS input buffer 16 and the CS input buffer 17 , respectively, to decode these signals and generate a column system activated signal Pc. Further, the decoder and the latch circuit 19 is connected to the WE input buffer 20 in addition to the CAS input buffer 15 , the RAS input buffer 16 and the CS input buffer 17 . If the inputted command is write, the decoder and the latch circuit 19 activates a write enable signal Pe. If the inputted command is read, it activates a read enable signal Pf, respectively.
When the column system activated signal Pc is activated, the input column address latch controller 21 outputs a column address entry pulse Pd. This pulse Pd opens the transfer gates 32 - 6 and 32 - 7 . Therefore, the address information of the address input buffers 22 - 1 and 22 - 2 are transferred to the address latches 23 - 1 and 23 - 2 in a column address counter 39 , so that addresses K 1 and K 2 of the core buses 24 - 1 and 24 - 2 are decided.
On the other hand, activation of the column system activated signal Pc allows the burst length counter 25 to be activated. The pulse signal Pb counts up the activated burst length counter 25 by number of times corresponding to the burst length. During this time, the activated burst length counter 25 is activating a burst operation activated signal Pg.
As understood from the circuit construction shown in FIG. 3, in the case that the CAS latency is 2 (CL 2 ), the column pulse transfer controller 26 activates a column pulse transfer signal Pj soon after the burst operation activated signal Pg is activated. This column pulse transfer signal Pj opens the transfer gates 32 - 3 and 32 - 4 to transfer the pulse signal Pa′ to the column bank controller 27 as a column operation synchronous pulse Pp and transfer the pulse signal Pb′ to the address latches 23 - 1 and 23 - 2 in a column address counter 39 as a column address latch pulse Pq. At this time, by the inverter 35 , a inverted signal of the above column address latch pulse Pq is also transferred to the address latches 23 - 1 and 23 - 2 .
In the present example, there is a margin in the activating timing of the column pulse transfer signal Pj with respect to the timing for activating these pulse signals Pa′ and Pb′. Therefore, finding a logical OR of the column system activated signal Pc and the burst operation activated signal Pg, the column pulse transfer signal Pj is generated.
Using the column operation synchronous pulse Pp as a trigger, the column bank controller 27 generates a write pulse Pl when the write enable signal Pe is active and generates a read pulse Pm when the read enable signal Pf is active. The write pulse Pl opens a write gate of the DQ buffer 28 in a memory cell portion MCA. As a result, it becomes possible to write into the memory cell allay 34 . Further, the read pulse Pm opens a read gate of the above DQ buffer 28 to output a cell data Pn to the data line 29 . The cell data Pn of the above data line 29 is transferred to the off chip driver 30 . After inputting a command, if the external clock VCLK at second cycles becomes active, the output pulse generator 31 outputs an output pulse Po by using the activated external clock VCLK as a trigger. This output pulse Po opens the transfer gate 32 - 5 , which is arranged on the output terminal of the off chip driver 30 . Then, an output data Dout is outputted to catch up with the external clock VCLK at third cycles.
On the other hand, while the column address latch pulse Pq, which is activated at the same time as the column operation synchronous pulse Pp, has been generated, the transfer gates 32 - 10 and 32 - 12 as backward registers are closed. The transfer gates 32 - 10 and 32 - 12 are located within the address latches 23 - 1 and 23 - 2 in the column address counter 39 . During read and write operation to the memory cell portion MCA as the column operation synchronous pulse Pp as a trigger, the core bus addresses K 1 and K 2 are latched. The column operation synchronous pulse Pp is generated at the same time as the column address latch pulse Pq. Further, at the same time, the transfer gates 32 - 9 and 32 - 11 as forward registers are opened and the address information at a single digit before is recorded in this register. Hereby, the information of the address latch 23 - 1 is transferred to the address latch 23 - 2 . If the pulse Pq is deactivated, the transfer gates 32 - 10 and 32 - 12 as the backward registers are opened to output the recorded address information at a single digit before to the core buses 24 - 1 and 24 - 2 .
In the case of CL 3 , as understandably from the timing chart in FIG. 5, the burst operation activated signal Pg turns to a column pulse transfer signal Ph with being delayed by one cycle by the pulse signal Pb at the register within the column pulse transfer controller 26 . In other words, the pulse signals Pa and Pb are transferred as the column operation synchronous pulse Pp and the column address latch pulse Pq with being delayed from the command input by one cycle, so that the access to the memory cell portion MCA is also delayed from the command input by one cycle and the date is outputted to catch up with the external clock VCLK at fourth cycle.
Next, the case that the write command is interrupted during the read operation of the CL 2 and the CL 3 is considered. As shown in FIG. 4, in the case of the CL 2 , upon inputting the write command, latches of the core bus addresses K 1 and K 2 due to the column address latch pulse Pq are released. Accordingly, the latching of the address is the same as that upon normal input of commands. On the contrary, in the case of the CL 3 , as shown in FIG. 5, when the write command is inputted, the core bus addresses K 1 and K 2 are latched in response to the column address latch pulse Pq. Therefore, the addresses ADD 1 and ADD 2 are latched from the address input buffers 22 - 1 and 22 - 1 to be held in the address latches 23 - 1 and 23 - 3 within the counter at once. Then, after the column address latch pulse Pq is inactive, the addresses ADD 1 and ADD 2 are outputted to the core buses 24 - 1 and 24 - 2 .
As described above, using the same column operation synchronous pulse in read and write, there is a merit such that a system for latching the address when the column command interrupts during the column burst operation.
In the mean time, in the above described conventional synchronous DRAM, as shown in FIGS. 6 and 7, after the completion of the write burst, the case that a precharge command is inputted at the next cycle. FIG. 6 is a timing chart illustrating the operation in the case that the CAS latency is 2 (CL 2 ) and FIG. 7 is a timing chart illustrating the operation in the case that the CAS latency is 3 (CL 3 ). Here, a time from writing by the write pulse Pm to resetting of the word line WL is determined as tWR. The time from input of the precharge command to the word line reset is not changed in the CL 2 and the CL 3 . On the other hand, the timing of the column operation synchronous pulse is uniquely determined by the CAS latency, which is important for determining a timing of the read operation. In other words, even when the column command is read or write, in the column operation synchronous pulse, the CL 3 is delayed than the CL 2 . Therefore, if the CAS latency is 3 (CL 3 ), tWR is smaller than in the case where the CAS latency is 2 (CL 2 ). Consequently, a word line WL is reset before the data is completely written into a memory cell immediately before precharging.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to provide a semiconductor memory, which is capable of sufficiently securing an operational margin of a column system circuit.
The object of the present invention is attained by a semiconductor memory for synchronizing at least a part of input of a command and write or read of data with an external clock and generating a column operation synchronous pulse having the same number as that of a burst length within the semiconductor memory by using an internal operation synchronous pulse having the external clock as a trigger and after inputting a column system command, using the internal operation synchronous pulse as a trigger comprising a first path to which a first column operation synchronous pulse is transferred during read; a second path to which a second column operation synchronous pulse, which is different from the first column operation synchronous pulse, is transferred during write; and a switching circuit for selectively switching the first path and the second path.
Further, the object of the present invention is attained by a semiconductor memory for synchronizing input of a command and write or read of data with an external clock and generating a column operation synchronous pulse having the same number as that of a burst length within the semiconductor memory by using an internal operation synchronous pulse having the external clock as a trigger and after inputting a column system command, using the internal operation synchronous pulse as a trigger comprising a first pulse generator for generating a first column operation synchronous pulse for read within a chip with an external clock as a trigger; a second pulse generator for generating a second column operation synchronous pulse for read within a chip with the external clock as a trigger; a first signal line provided with a first column operation synchronous pulse for read to be outputted from the first pulse generator during read; a second signal line provided with a second column operation synchronous pulse for write to be outputted from the second pulse generator during read; and a column pulse transfer controller for controlling transfer of a first column operation synchronous pulse from the first pulse generator to the first signal line and transfer of a second column operation synchronous pulse from the second pulse generator to the second signal line, respectively.
Still further, the object of the present invention is attained by a synchronous DRAM comprising a first pulse generator for generating a first column operation synchronous pulse for read within a chip with an external clock as a trigger; a second pulse generator for generating a second column operation synchronous pulse for read within a chip with the external clock as a trigger; a first signal line provided with a first column operation synchronous pulse for read to be outputted from the first pulse generator during read; a second signal line provided with a second column operation synchronous pulse for write to be outputted from the second pulse generator during read; a first transfer gate to be arranged between the first pulse generator and the first signal line; a second transfer gate to be arranged between the second pulse generator and the second signal line; and a column pulse transfer controller for controlling the first and second transfer gate and controlling transfer of a first column operation synchronous pulse from the first pulse generator to the first signal line and transfer of a second column operation synchronous pulse from the second pulse generator to the second signal line, respectively.
In the semiconductor memory of the present invention, which has the above configurations, the timing of a synchronous pulse can be adjusted in conformity to a limiting factor to secure sufficiently an operational margin of a column system circuit, since a column operation synchronous pulses, which are different between read and write, is used. Hence, if the CAS latency is 3 , tWR is smaller than in the case where the CAS latency is 2 . Consequently, so that a problem such that a word line is reset before the data is completely written into a memory cell immediately before precharging is avoided.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.
FIG. 1 is a block diagram showing extractively a circuit in reference to the control of a column system basic pulse in a synchronous DRAM to explain with respect to a conventional semiconductor memory;
FIG. 2 is a circuit diagram showing a constitutional example of an input column address latch controller in the circuit shown in FIG. 1 to explain with respect to a conventional semiconductor memory;
FIG. 3 is a circuit diagram showing a column pulse transfer controller in the circuit shown in FIG. 1 to explain with respect to a conventional semiconductor memory;
FIG. 4 is a timing chart showing respective signal waveforms typically in the case that the CAS latency is 2 in the semiconductor memory shown in FIGS. 1 to 3 ;
FIG. 5 is a timing chart showing respective signal waveforms typically in the case that the CAS latency is 3 in the semiconductor memory shown in FIGS. 1 to 3 ;
FIG. 6 is a timing chart illustrating the operation in the case that the CAS latency is 2 ;
FIG. 7 is a timing chart illustrating the operation in the case that the CAS latency is 3 ;
FIG. 8 is a block diagram showing a construction of a synchronous DRAM schematically to explain with respect to a semiconductor memory according to a first embodiment of the present invention;
FIG. 9 is a block diagram showing extractively a circuit in reference to the control of a column system basic pulse in a synchronous DRAM to explain with respect to a semiconductor memory according to a first embodiment of the present invention;
FIG. 10 is a circuit diagram showing a constitutional example of an input write address latch controller in the circuit shown in FIG. 9 to explain with respect to a first embodiment of the present invention;
FIG. 11 is a circuit diagram showing a constitutional example of a column pulse transfer controller in the circuit shown in FIG. 9 to explain with respect to a first embodiment of the present invention;
FIG. 12 is a timing chart showing respective signal waveforms typically in the case that a write command interrupts during the read operation when the CAS latency is 3 in the semiconductor memory shown in FIGS. 9 to 11 ; and
FIG. 13 is a block diagram showing extractively a circuit in reference to the control of a column system basic pulse in a synchronous DRAM to explain with respect to a semiconductor memory according to a second embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 8 to 11 illustrate a semiconductor memory according to a first embodiment of the present invention, respectively. FIG. 8 is a block diagram schematically showing a construction of a synchronous DRAM. FIG. 9 is a block diagram showing extractively a circuit in reference to the control of a column system basic pulse in this synchronous DRAM. FIG. 10 is a circuit diagram showing a constitutional example of an input write address latch controller in the circuit shown in FIG. 9 . FIG. 11 is a circuit diagram showing a constitutional example of a column pulse transfer controller in the circuit shown in FIG. 9 . In FIGS. 8 to 11 , the identical reference numerals are given to the elements, which correspond to the elements in FIGS. 1 to 3 .
As shown in FIG. 8, the memory cell allay in this synchronous DRAM is divided into four banks, namely, banks MCA- 1 to MCA- 4 . Respective banks MCA- 1 to MCA- 4 are composed of memory cell allays 34 - 1 to 34 - 4 , CSL drivers 40 - 1 to 40 - 4 , DQ buffers 28 - 1 to 28 - 4 , and circuit blocks 50 - 1 to 50 - 4 each having column address decoder and controller or the like, respectively.
Further, corresponding to the above respective banks MCA- 1 to MCA- 4 , column bank controllers 27 - 1 to 27 - 4 are provided, respectively. The column bank controllers 27 - 1 to 27 - 4 controlled DQ buffers 28 - 1 to 28 - 4 provided in the banks MCA- 1 to MCA- 4 . Commands CMD are inputted to CAS input buffer 15 , RAS input buffer 16 , CS input buffer 17 and WE input buffer 20 via command pads 62 . A decoder and latch 19 is connected to the input buffers 15 , 16 , 17 and 20 , and latching and decoding the commands CMD. The decoder and latch 19 controlling the each column bank controllers 27 - 1 to 27 - 4 . Address signals S ADD are inputted to column address counter 39 via address pads 63 and address input buffers 22 . Each column address decoders provided in the circuit blocks 50 - 1 to 50 - 4 connected to receive the output signals (core bus addresses K 1 and K 2 ) of the column address counter 39 . The DQ buffers 28 - 1 to 28 - 4 in the above respective banks MCA- 1 to MCA- 4 are intended to be inputted with a data S DATA from a data input/output pads 64 via data lines 29 , respectively or the data outputted from the DQ buffers 28 - 1 to 28 - 4 are intended to be outputted to the outside via the data lines 29 , off chip drivers (OCD.) 30 and the data input/output pads 64 . Further external clock VCLK inputted in the clock input pad 65 supplied with column pulse generator 66 via an external input buffer 11 . Each column bank controllers 27 - 1 to 27 - 4 connected to receive column operation synchronous pulses Ppr and Ppw generated by the column pulse generator 66 .
As shown in FIG. 9, the circuit in reference to the control of the column system basic pulse in a synchronous DRAM is composed of the external clock input buffer 11 , pulse generators 12 - 1 , 12 - 2 , 12 - 3 , 13 - 1 and 13 - 2 , delay circuits 14 - 1 , 14 - 2 , the CAS input buffer 15 , the RAS input buffer 16 , the CS input buffer 17 , a decoder 18 , the decoder and latch circuit 19 , the WE input buffer 20 , an input column address latch controller 21 , address input buffers 22 - 1 , 22 - 2 , address latches 23 - 1 , 23 - 2 , core buses 24 - 1 , 24 - 2 (addresses K 1 , K 2 ), a burst length counter 25 , a column pulse transfer controller 26 ′, the column bank controller 27 , the DQ buffer 28 , a data line 29 , an off chip driver 30 , an output pulse generator 31 , transfer gates 32 - 1 to 32 - 8 , a column address decoder 33 , the memory cell allay 34 , an inverter 35 , an input write address latch controller 36 , an AND gate 37 and signal lines 38 - 1 , 38 - 2 or the like.
The circuit shown in FIG. 9 is composed of a pulse generator 12 - 3 , a transfer gate 32 - 8 , a signal line 38 - 1 for transferring a column operation synchronous pulse Ppr for read, a signal line 38 - 2 for transferring a column operation synchronous pulse Ppw for write, an input write address latch controller 36 and an AND gate 37 or the like in addition to the conventional circuit shown in FIG. 1 .
In other words, according to the present invention, the column operation synchronous pulse (internal operation synchronous pulse) into a write only pulse and a read only pulse. In this embodiment, an example of a method using different column operation synchronous pulse in a read operation and a write operation, respectively, despite of CAS latency (CL), a write operation is performed at a conventional timing that the CAS latency is 2 (CL 2 ).
The above pulse generator 12 - 3 is connected to the delay circuit 14 - 1 in parallel with the pulse generator 12 - 2 . This pulse generator 12 - 3 generates a pulse signal Pa′w to be activated by the same timing as that of the pulse signal Pa′. The pulse signal Pa is transferred to the signal line 38 - 1 as a column operation synchronous pulse Ppr for read in response to the column pulse transfer signal Ph generated by the column pulse transfer controller 26 ′ during a read operation when the CAS latency is 3 (CL 3 ). The pulse signal Pa′w generated by the pulse generator 12 - 3 is transferred to the signal line 38 - 2 as a column operation synchronous pulse Ppw for write in response to the transfer signal Pjw despite of the CAS latency. Further, a pulse signal Pa′r is transferred to the signal line 38 - 1 as a column operation synchronous pulse Ppr for read by a read column pulse transfer signal Pjr when the CAS latency is 2 (CL 2 ). The pulse Pa′w is transferred to the signal line 38 - 2 as the column operation synchronous pulse Ppw for write by the transfer signal Pjw to be generated by the column pulse transfer controller 26 ′ during a write operation.
Further, the column pulse transfer controller 26 ′ is provided with a write input pulse Pr to be outputted from the WE input buffer 20 , a write enable signal Pe and a read enable signal Pf in addition to the pulse signal Pb to be outputted from the above pulse generator 13 - 1 , the column system activated signal Pc to be outputted form the above decoder 18 and the burst operation activated signal Pg to be outputted from the above burst length counter 25 . Further, the column pulse transfer controller 26 ′ is intended to output the pulse signal Ph for controlling the above transfer gates 32 - 1 and 32 - 2 , a column pulse transfer signal Pjr for read for controlling the above transfer gate 32 - 3 , a column pulse transfer signal Pjw for write for controlling the above transfer gate 32 - 8 and a column pulse transfer signal Pja for controlling the above transfer gate 32 - 4 .
As shown in FIG. 10, the above input write address latch controller 36 is comprised of a NAND gate 71 , a transfer gate 72 and inverters 73 , 74 and 75 . A write column address entry pulse Ps is outputted from the input write address latch controller 36 to be provided to one input terminals of the AND gate 37 . Then, the write column address entry pulse Ps releases latches of the core bus addresses K 1 and K 2 in the address latches 23 - 1 and 23 - 2 by the column address latch pulse Pq.
Further, as shown in FIG. 11, the above column pulse transfer controller 26 ′ is composed of AND gates 81 to 83 , NAND gates 84 to 89 , an OR gate 90 , a transfer gate 91 and inverters 92 to 96 . This column pulse transfer controller 26 ′ basically comprises two flip-flop latch circuits. Upon inputting the column command at the CL 2 or inputting a write command at the CL 3 , the above flip-flop latch circuit activates an output signal Pj′ of the NAND gate 86 from the column system activated signal Pc to latch the activated output signal Pj′ with the burst operation activated signal Pg. When the burst operation is completed, the latch is released with the signal SC and the output signal Pj′ of the NAND gate 86 is deactivated. The above signal SC is a negative pulse to be generated at completion of the burst operation. Here, the explanation thereof is omitted. During the read operation, a signal Pjr is generated from the output signal Pj′ of the NAND gate 86 and during the write operation, the transfer signal Pjw is generated from the output signal Pj′ of the NAND gate 86 . During write and read operation, a signal Pja is generated from the output signal Pj′ of the NAND gate 86 . On the other hand, the flip-flop circuit at the lower column activates the output the pulse signal Ph′ of the NAND gate 88 from the column system activated signal Pc upon inputting the read command at the CL 3 to latch the activated output signal Ph′ with the burst operation activated signal Pg. When the transfer gate 91 is opened due to deactivation of the pulse signal Pb, the signal Ph′ is changed into the signal Ph at one cycle's delay. Further, in the CL 3 , as well as in the CL 2 , after the burst operation is completed, the latch is released by the signal SC and the output signal Ph′ is deactivated. In this state, the transfer gate 91 is opened by deactivation of the pulse signal Pb, so that the column pulse transfer signal Ph is deactivated at one cycle's delay.
The above column pulse transfer controller 26 ′ has a system such that the latch of the output signal Ph′ of the NAND gate 88 is released by the signal SA and the latch of the output signal Pj′ of the NAND gate 86 is released. When the read interrupts during the write burst at the CL 3 or when the write interrupts during the read burst at the CL 3 , the column pulse transfer controller 26 ′ is capable of switching the output signal Ph′ of the NAND gate 88 to the output signal Pj′ of the NAND gate 86 .
In FIGS. 9 to 11 , in order to simplify the illustrations, it is shown that only one sided MOS transistor gates of transfer gates 32 - 1 to 32 - 8 , 72 , 91 are provided with signals. However, other sided MOS transistor gates are provided with inverted ones of the above signals. Further, the CL 2 ACT and the CL 3 ACT in FIG. 11 are signals to be activated at the CL 2 and the CL 3 , respectively.
Next, with reference to a timing chart in FIG. 12, the operation of the synchronous DRAM having the above described construction is explained below.
FIG. 12 is the timing chart showing the write interruption during the read burst operation at the CL 3 . Using the above described column synchronous pulse system, during the write interruption during the read burst at the CL 3 , the address informations ADD 1 and ADD 2 in the address input buffers 22 - 1 and 22 - 2 are latched, so that the latches of the address latches 23 - 1 and 23 - 2 of the core buses 24 - 1 and 24 - 2 should be released.
In the present embodiment, only upon inputting the write command, the core bus address latch mask pulse Psis activated at the same time of the column address entry pulse Pd. Then, the activated core bus address latch mask pulse Ps masks the column address latch pulse Pq to output the addresses ADD 1 and ADD 2 to the core buses 24 - 1 and 24 - 2 . The above pulse Ps is generated by the input write address latch controller 36 (see FIG. 10 ). This controller 36 is composed of the write input pulse Pr in addition to the input signal of the input column address latch controller 21 for generating the column address entry pulse Pd. The logic configurations of the input write address latch controller 36 and the input column address latch controller 21 are substantially identical and they are activated at the approximately same timing. Therefore, at the same time that the input write address latch controller 36 opens the transfer gates 32 - 10 and 32 - 12 and entries the addresses ADD 1 and ADD 2 , the latch state of the address latches 23 - 1 and 23 - 2 are released. As a result, the entry addresses ADD 1 and ADD 2 are transferred to the core buses 24 - 1 and 24 - 2 at the same timing as that of a normal command input.
According to the above configurations, since a column operation synchronous pulses, which are different between read and write, is used, the semiconductor memory of the present invention is capable of adjusting a timing of a synchronous pulse in conformity to a limiting factor to secure sufficiently an operational margin of a column system circuit. Thus, in the case that the CAS latency is 3 , tWR is smaller compared with the case that the CAS latency is 2 , so that a problem such that a word line is reset in the course that writing into a memory cell just before precharging is not sufficient is avoided.
FIG. 13 is a block diagram showing extractively a circuit in reference to the control of a column system basic pulse in a synchronous DRAM to explain with respect to a semiconductor memory according to a second embodiment of the present invention. According to the above first embodiment, the output signal of the delay circuit 14 - 1 is provided to the pulse generators 12 - 2 and 12 - 3 . On the contrary, according to the present embodiment, the delay circuit 14 - 3 is further arranged and the output signal of this delay circuit 14 - 3 is provided to the pulse generator 12 - 2 so that the output signal of the above delay circuit 14 - 1 is provided to the pulse generator 12 - 3 . In addition, the delay circuit 14 - 4 , the pulse generator 13 - 3 and the transfer gate 32 - 13 are further arranged.
According to the above construction, the same operation as that of the circuit shown in FIG. 9 is performed to basically obtain the same effect as that of the circuit shown in FIG. 9 .
As explained above, according to the present invention, a semiconductor memory such that the operational margin of the column system circuit can be sufficiently secured.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. | To provide a semiconductor memory for synchronizing input of a command except for POWER-DOWN-EXIT or the like and write or read of data with an external clock and generating a column operation synchronous pulse having the same number as that of a burst length within the semiconductor memory by using an internal operation synchronous pulse having this external clock as a trigger and after activation of a column system circuit, using the internal operation synchronous pulse as a trigger. This semiconductor memory uses column pulse transfer signals, which are different between read and write to control a column system circuit. | 7 |
CROSS REFERENCE TO RELATED APPLICATION
This non-provisional application claims priority from provisional application U.S. Ser. No. 60/411,733 filed Sep. 18, 2002.
FIELD OF THE INVENTION
The present invention relates to cyclopentylindole derivatives and pharmaceutical compositions comprising said derivatives useful for the treatment of various psychiatric disorders and premature ejaculation.
BACKGROUND OF THE INVENTION
Selective serotonin reuptake inhibitors (SSRIs) are effective for the treatment of mental depression and have been reported to be useful for treating chronic pain. See R. W. Fuller, “Pharmacologic Modification of Serotonergic Function: Drugs for the Study and Treatment of Psychiatric and Other Disorders,” J. Clin. Psychiatry, 47:4 (Suppl.) April 1986, pp. 4–8 and Selective Serotonin Reuptake Inhibitors. Edited by J P Feighner and W F Boyer, Chichester, England. John Wiley & Sons, 1991, pp 89–108. SSRI's have also demonstrated efficacy for the treatment of anxiety disorders. More recently, SSRI's have demonstrated efficacy in the treatment of premature ejaculation. See Kim and Paick, Short-term Analysis of the Effects of As Needed Use of Sertraline at 5 pm for the Treatment of Premature Ejaculation, Urology 54:544–547 (1999); Kim and Paick, Self Therapy with Sertraline given PRN at 5 pm in treatment of Premature Ejaculation, Journal of Urology 54:544–547 (1998); McMahon and Touma, Treatment of Premature Ejaculation with Paroxetine Hydrochloride As Needed: 2 Single-Blind Placebo Controlled Crossover Studies Journal of Urology 161:1826–1830 (1999); Haensal et al., Clomipramine and sexual function in men with premature ejaculation and controls Journal of Urology 158:1310–1315 (1998); and McMahon and Touma, Treatment of Premature Ejaculation with Paraoxetine Hydrochloride International Journal Impotence Research 11:241–246 (1999).
In U.S. Pat. No. 5,468,768, C 5-7 cycloalkyl indole derivatives, more particularly examples of substituted indol-3yl cyclohexyl amines were disclosed for the treatment of headache. See also U.S. Pat. No. 5,583,149. In U.S. Pat. No. 5,468,767 C 5-7 cycloalkyl indole derivatives, more particularly examples of substituted indol-3yl cyclohexyl amines were disclosed for the treatment of depression. See also U.S. Pat. No. 5,607,961. None of said patents discloses use of said derivatives for the treatment of premature ejaculation. Thus, novel SSRI's effective for the treatment of premature ejaculation and other disorders would be greatly advantageous.
SUMMARY OF THE INVENTION
Thus according to a first embodiment of a first aspect of the present invention are provided compounds of Formula (I)
and pharmaceutically acceptable salts or solvates thereof
wherein
A 1 and A 2 are each independently C 1-4 alkylene or a bond; A 3 is a bond, C 1-4 alkylene or C 1-4 alkylidene; A 4 is C 1-4 alkylene or a bond and is attached to X, X 1 or X 2 ; X, X 1 , X 2 and X 3 are independently C or CH; J is C 1-4 alkyl;
p is 0 or 1;
R 1 and R 2 are independently H, C 1-3 alkyl, C 3-6 cycloalkyl, phenyl, —O-phenyl, —N(H)C(O)O—C 1-4 alkyl or C 1-4 alkyl-N(H)C(O)O—;
said C 3-6 cycloalkyl, phenyl or O-phenyl being independently and optionally substituted with C 1-4 alkyl, C 1-3 alkoxy, indolyl or halo;
wherein said indolyl is optionally substituted by halo or cyano;
or are independently selected from the group of heterocyclic moieties consisting of thienyl, furanyl, pyrrolyl, pyrrolinyl, pyrrolidinyl, imidazolyl, imidazolinyl, imidazolidinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, pyridyl, pyrimidinyl, piperidinyl, piperazinyl, morpholino, adamantyl, indolyl, isoindolyl, indolinyl, quinolinyl, dihydroquinolinyl, tetrahydroquinolinyl, isoquinolinyl, dihydroisoquinolinyl and tetrahydroisoquinolinyl, wherein said heterocyclic moieties are optionally substituted with halo, C 1-4 alkyl, C 1-4 alkoxy or cyano; or wherein -A 1 -R 1 and -A 2 -R 2 together with the nitrogen to which they are attached form pyrrolyl, pyrrolinyl, pyrrolidinyl, imidazolyl, imidazolinyl, imidazolidinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, pyridyl, pyrimidinyl, piperidinyl, piperazinyl, morpholino, indolyl, isoindolyl, indolinyl, isoindolinyl, quinolinyl, dihydroquinolinyl, tetrahydroquinolinyl, isoquinolinyl, dihydroisoquinolinyl or tetrahydroisoquinolinyl and are optionally substituted with halo, C 1-4 alkyl, C 1-4 alkoxy, cyano or benzyl;
R 3 is H or C 1-4 alkyl;
m is 0 or 1;
R 4 and R 5 are independently hydrogen, cyano, halo, nitro, C 1-3 alkyl or C 1-3 perfluoroalkyl;
wherein said R 4 or R 5 may be independently attached to G 1 , X, X 1 , X 2 or X 3 ; n is 0 or 1;
G is N, O or S; G 1 is N, C or CH; Y is (D)H wherein D is C; and Z is (E)H wherein E is C; provided that
both R 4 and R 5 are not attached to the same of said G 1 , X, X 1 , X 2 or X 3 ; if G is or S, then m is 0; if G is N, then m is 1; if R 1 is C 3-6 cycloalkyl, phenyl or O-phenyl being independently and optionally substituted with C 1-4 alkyl, C 1-3 alkoxy, indolyl or halo; wherein said indolyl is optionally substituted by halo or cyano, then R 2 is H or C 1-3 alkyl; if R 2 is C 3-6 cycloalkyl, phenyl or O-phenyl being independently and optionally substituted with C 1-4 alkyl, C 1-3 alkoxy, indolyl or halo; wherein said indolyl is optionally substituted by halo or cyano, then R 1 is H or C 1-3 alkyl; if -A 1 -R 1 and -A 2 -R 2 together with the nitrogen to which they are attached form pyrrolyl, pyrrolinyl, pyrrolidinyl, imidazolyl, imidazolinyl, imidazolidinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, pyridyl, pyrimidinyl, piperidinyl, piperazinyl, morpholino, indolyl, isoindolyl, indolinyl, isoindolinyl, quinolinyl, dihydroquinolinyl, tetrahydroquinolinyl, isoquinolinyl, dihydroisoquinolinyl or tetrahydroisoquinolinyl and are optionally substituted with halo, C 1-4 alkyl, C 1-4 alkoxy, cyano or benzyl, then p is 0; if R 1 is —N(H)C(O)OC 1-4 alkyl, C 1-4 alkyl-N(H)C(O)O— or said heterocyclic moiety wherein said heterocyclic moiety contains a nitrogen atom and said nitrogen atom is attached to A 1 , then A 1 is C 2-4 alkylene; if R 2 is —N(H)C(O)OC 1-4 alkyl, C 1-4 alkyl-N(H)C(O)O— or said heterocyclic moiety wherein said heterocyclic moiety contains a nitrogen atom and said nitrogen atom is attached to A 2 , then A 2 is C 2-4 alkylene; if R 1 is N(H)C(O)O—C 1-4 alkyl, C 1-4 alkyl-N(H)C(O)O— or a heterocyclic moiety selected from the group consisting of thienyl, furanyl, pyrrolyl, pyrrolinyl, pyrrolidinyl, imidazolyl, imidazolinyl, imidazolidinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, pyridyl, pyrimidinyl, piperidinyl, piperazinyl, morpholino, adamantyl, indolyl, isoindolyl, indolinyl, quinolinyl, dihydroquinolinyl, tetrahydroquinolinyl, isoquinolinyl, dihydroisoquinolinyl and tetrahydroisoquinolinyl, wherein said heterocyclic moieties are optionally substituted with halo, C 1-4 alkyl, C 1-4 alkoxy or cyano, then R 2 is H or C 1-3 alkyl; if R 2 is —N(H)C(O)O—C 1-4 alkyl, C 1-4 alkyl-N(H)C(O)O— or a heterocyclic moiety selected from the group consisting of thienyl, furanyl, pyrrolyl, pyrrolinyl, pyrrolidinyl, imidazolyl, imidazolinyl, imidazolidinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, pyridyl, pyrimidinyl, piperidinyl, piperazinyl, morpholino, adamantyl, indolyl, isoindolyl, indolinyl, quinolinyl, dihydroquinolinyl, tetrahydroquinolinyl, isoquinolinyl, dihydroisoquinolinyl and tetrahydroisoquinolinyl,
wherein said heterocyclic moieties are optionally substituted with halo, C 1-4 alkyl, C 1-4 alkoxy or cyano, then R 1 is H or C 1-3 alkyl;
if R 4 or R 5 are attached to G 1 , then G 1 is C; if A 4 , R 4 or R 5 are attached to X, then X is C; if A 4 , R 4 or R 5 are attached to X 1 , then X 1 is C; if A 4 , R 4 or R 5 are attached to X 2 , then X 2 is C; if R 4 or R 5 are attached to X 3 , then X 3 is C.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein p is 0.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein G is N and G 1 is CH.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein G is S and G 1 is CH.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein G is N and G 1 is N.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein G is S and G 1 is N.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein G is O and G 1 is N.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein R 1 is methyl and R 2 is methyl.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein R 1 is H and R 2 is C 3-6 cycloalkyl wherein said C 3-6 cycloalkyl is substituted with indolyl and wherein said indolyl is optionally substituted by halo or cyano.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein A 1 is a bond, R 1 is methyl, A 2 is a bond and R 2 is methyl.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein R 1 and R 2 are independently H, C 1-3 alkyl, C 3-6 cycloalkyl, phenyl, —O-phenyl, —N(H)C(O)O—C 1-4 alkyl or C 1-4 alkyl-N(H)C(O)O—; said C 3-6 cycloalkyl, phenyl or O-phenyl being independently and optionally substituted with C 1-4 alkyl, C 1-3 alkoxy or halo.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein R 1 and R 2 are independently H, C 1-3 alkyl, phenyl, said phenyl being independently and optionally substituted with C 1-4 alkyl, C 1-3 alkoxy or halo.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein R 1 and R 2 are independently H or unsubstituted C 1-3 alkyl or phenyl.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein R 1 and R 2 are independently H or unsubstituted C 1-3 alkyl or phenyl and A 1 and A 2 are independently C 1-4 alkylene.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein -A 1 -R 1 and -A 2 -R 2 together with the nitrogen to which they are attached form pyrrolyl, pyrrolinyl, pyrrolidinyl, piperidinyl, piperazinyl, morpholino, indolyl, isoindolyl, indolinyl, isoindolinyl, quinolinyl, dihydroquinolinyl, tetrahydroquinolinyl, isoquinolinyl, dihydroisoquinolinyl or tetrahydroisoquinolinyl and are optionally substituted with halo, C 1-4 alkyl, C 1-4 alkoxy, cyano or benzyl.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein -A 1 -R 1 and -A 2 -R 2 together with the nitrogen to which they are attached form unsubstituted pyrrolyl, pyrrolinyl, pyrrolidinyl, piperidinyl, piperazinyl, morpholino, indolyl, isoindolyl, indolinyl, isoindolinyl, quinolinyl, dihydroquinolinyl, tetrahydroquinolinyl, isoquinolinyl, dihydroisoquinolinyl or tetrahydroisoquinolinyl.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein -A 1 -R 1 and -A 2 -R 2 together with the nitrogen to which they are attached form unsubstituted pyrrolidinyl, piperidinyl, morpholino or isoindolinyl.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein R 3 is H and m is 1.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein n is 0.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein R 4 and R 5 are halo.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein R 4 is C 1-3 alkyl and is attached to G 1 .
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein R 4 is C 1-3 perfluoroalkyl and is attached to G 1 .
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein R 4 is hydrogen.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein R 4 is fluoro.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein R 4 is cyano.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein R 4 is cyano or fluoro.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein R 4 and R 5 are each fluoro.
According to another embodiment of the first aspect of the present invention are compounds of Formula (I) wherein the hydrogen atom attached to D is in the trans configuration to the hydrogen atom attached to E.
According to another embodiment of the first aspect of the present invention are compounds of Formula (I) wherein the hydrogen atom attached to D is in the cis configuration to the hydrogen atom attached to E.
According to another embodiment of the first aspect of the present invention are compounds of Formula (I) wherein D in relation to the four moieties to which it is attached has an absolute configuration of S; E in relation to the four moieties to which it is attached has an absolute configuration of S.
According to another embodiment of the first aspect of the present invention are compounds of Formula (I) wherein D in relation to the four moieties to which it is attached has an absolute configuration of S; E in relation to the four moieties to which it is attached has an absolute configuration of R.
According to another embodiment of the first aspect of the present invention are compounds of Formula (I) wherein D in relation to the four moieties to which it is attached has an absolute configuration of R; E in relation to the four moieties to which it is attached has an absolute configuration of S.
According to another embodiment of the first aspect of the present invention are compounds of Formula (I) wherein D in relation to the four moieties to which it is attached has an absolute configuration of R; E in relation to the four moieties to which it is attached has an absolute configuration of R.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein A 3 is a bond.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein A 3 is C 1-4 alkylene.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein A 3 is C 1-4 alkylidene.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein A 3 is methylene.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein A 4 is a bond.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein A 4 is methylene.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein A 4 is attached X 1 .
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein A 4 is attached X.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein R 4 is attached X.
According to another embodiment of the first aspect of the present invention are provided compounds of Formula (I) according to the first embodiment of the first aspect wherein
A 1 and A 2 are each independently C 1-4 alkylene or a bond; A 3 is a bond; A 4 is a bond and is attached to X 1 ; X and X 1 are each C; X 2 and X 3 are each CH; p is 0; R 1 and R 2 are independently H, C 1-3 alkyl, C 3-6 cycloalkyl, phenyl, —O-phenyl, —N(H)C(O)O—C 1-4 alkyl or C 1-4 alkyl-N(H)C(O)O—;
said C 3-6 cycloalkyl, phenyl or O-phenyl being independently and optionally substituted with C 1-4 alkyl, C 1-3 alkoxy or halo; or are independently selected from the group of heterocyclic moieties consisting of thienyl, furanyl, pyrrolyl, pyrrolinyl, pyrrolidinyl, imidazolyl, imidazolinyl, imidazolidinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, pyridyl, pyrimidinyl, piperidinyl, piperazinyl, morpholino, adamantyl, indolyl, isoindolyl, indolinyl, quinolinyl, dihydroquinolinyl, tetrahydroquinolinyl, isoquinolinyl, dihydroisoquinolinyl and tetrahydroisoquinolinyl, wherein said heterocyclic moieties are optionally substituted with halo, C 1-4 alkyl, C 1-4 alkoxy or cyano; or wherein -A 1 -R 1 and -A 2 -R 2 together with the nitrogen to which they are attached form pyrrolyl, pyrrolinyl, pyrrolidinyl, imidazolyl, imidazolinyl, imidazolidinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, pyridyl, pyrimidinyl, piperidinyl, piperazinyl, morpholino, indolyl, isoindolyl, indolinyl, isoindolinyl, quinolinyl, dihydroquinolinyl, tetrahydroquinolinyl, isoquinolinyl, dihydroisoquinolinyl or tetrahydroisoquinolinyl and are optionally substituted with halo, C 1-4 alkyl, C 1-4 alkoxy, cyano or benzyl;
R 3 is H;
m is 1;
R 4 is hydrogen, cyano, halo, nitro, C 1-3 alkyl or C 1-3 perfluoroalkyl and is attached to X; n is 0; G is N; G 1 is CH; Y is (D)H wherein D is C; and Z is (E)H wherein E is C; provided that
if R 1 is —N(H)C(O)OC 1-4 alkyl, C 1-4 alkyl-N(H)C(O)O— or said heterocyclic moiety wherein said heterocyclic moiety contains a nitrogen atom and said nitrogen atom is attached to A 1 , then A 1 is C 2-4 alkylene; if R 2 is —N(H)C(O)OC 1-4 alkyl, C 1-4 alkyl-N(H)C(O)O— or said heterocyclic moiety wherein said heterocyclic moiety contains a nitrogen atom and said nitrogen atom is attached to A 2 , then A 2 is C 2-4 alkylene; if R 1 is N(H)C(O)O—C 1-4 alkyl, C 1-4 alkyl-N(H)C(O)O— or a heterocyclic moiety selected from the group consisting of thienyl, furanyl, pyrrolyl, pyrrolinyl, pyrrolidinyl, imidazolyl, imidazolinyl, imidazolidinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, pyridyl, pyrimidinyl, piperidinyl, piperazinyl, morpholino, adamantyl, indolyl, isoindolyl, indolinyl, quinolinyl, dihydroquinolinyl, tetrahydroquinolinyl, isoquinolinyl, dihydroisoquinolinyl and tetrahydroisoquinolinyl, wherein said heterocyclic moieties are optionally substituted with halo, C 1-4 alkyl, C 1-4 alkoxy or cyano, then R 2 is H or C 1-3 alkyl; and if R 2 is —N(H)C(O)O—C 1-4 alkyl, C 1-4 alkyl-N(H)C(O)O— or a heterocyclic moiety selected from the group consisting of thienyl, furanyl, pyrrolyl, pyrrolinyl, pyrrolidinyl, imidazolyl, imidazolinyl, imidazolidinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, pyridyl, pyrimidinyl, piperidinyl, piperazinyl, morpholino, adamantyl, indolyl, isoindolyl, indolinyl, quinolinyl, dihydroquinolinyl, tetrahydroquinolinyl, isoquinolinyl, dihydroisoquinolinyl and tetrahydroisoquinolinyl, wherein said heterocyclic moieties are optionally substituted with halo, C 1-4 alkyl, C 1-4 alkoxy or cyano, then R 1 is H or C 1-3 alkyl.
According to various embodiments of a second aspect of the present invention are provided pharmaceutically acceptable formulations comprising compounds of Formula (I) as defined herein.
Disorders of particular interest include depression, attention deficit hyperactivity disorder, obsessive-compulsive disorder, post-traumatic stress disorder, substance abuse disorders and sexual dysfunction including (in particular) premature ejaculation. The compounds of the present invention may be administered alone or as part of a combination therapy.
Premature ejaculation may be defined as persistent or recurrent ejaculation before, upon or shortly after penile penetration of a sexual partner. It may also be defined as ejaculation occurring before the individual wishes [see The Merck Manual, 16 th edition, p. 1576, published by Merck Research Laboratories, 1992].
Thus according to various embodiments of a third aspect of the present invention are provided methods of treating conditions selected from the group consisting of depression, attention deficit hyperactivity disorder, obsessive-compulsive disorder, post-traumatic stress disorder, substance abuse disorders and sexual dysfunction including and in particular premature ejaculation comprising the administration to a human in need thereof an effective amount of pharmaceutically acceptable formulations comprising compounds of the present invention as defined herein.
Other embodiments of the present invention may comprise suitable combinations of two or more of the embodiments and/or aspects disclosed herein.
Yet other embodiments and aspects of the invention will be apparent according to the description provided below.
DETAILED DESCRIPTION OF THE INVENTION
The description of the invention herein should be construed in congruity with the laws and principals of chemical bonding. For example, it may be necessary to remove a hydrogen atom in order accommodate a substitutent at any given location.
An embodiment or aspect which depends from another embodiment or aspect, will describe only the variables having values or provisos that differ from the embodiment or aspect from which it depends.
If a variable is quantified with a value of zero, then any bond attaching said variable should no longer be represented, e.g., if n in (R 3 ) n equals 0, then the bond attaching R 3 to G should no longer be represented.
As used herein, “halo” or “halogen” includes fluoro, chloro, bromo and iodo.
As used herein, “C 1-4 alkylene” means a one to four carbon alkane having one hydrogen atom removed from two different carbon atoms in said alkane, e.g., —CH 2 CH 2 CH 2 —.
As used herein, “C 1-4 alkylidene” means a one to four carbon alkane having two hydrogen atoms removed from one carbon atom in said alkane, e.g.,
As used in the embodiments and claims herein the term “bond” is used as a means of eliminating an intervening variable to allow for a direct link between the remaining variables or atoms. For example, if where “A 1 and A 2 are each independently C 1-4 alkylene or a bond” A 1 is a bond, then R 1 is attached to N via a single bond.
It should be understood that the alternating double bond designations in the six-membered ring of the 5,6-membered fused structure represented in Formula (I) are relative and represent the delocalized π orbital electrons of said ring.
It is to be understood that the present invention may include any and all possible stereoisomers, geometric isomers, diastereoisomers, enantiomers, anomers and optical isomers, unless a particular description specifies otherwise.
The compounds of this invention may exist in the form of pharmaceutically acceptable salts. Such salts may include addition salts with inorganic acids such as, for example, hydrochloric acid and sulfuric acid, and with organic acids such as, for example, acetic acid, citric acid, methanesulfonic acid, toluenesulfonic acid, tartaric acid and maleic acid. Further, in case the compounds of this invention contain an acidic group, the acidic group may exist in the form of alkali metal salts such as, for example, a potassium salt and a sodium salt; alkaline earth metal salts such as, for example, a magnesium salt and a calcium salt; and salts with organic bases such as a trimethylammonium salt and an arginine salt. In the case of a sublingual formulation a saccharin salt or maleate salt may be of particular benefit. The compounds of the present invention may be hydrated or non-hydrated.
The compounds of this invention can be administered in such oral dosage forms as tablets, capsules (each of which includes sustained release or timed release formulations), pills, powders, granules, elixirs, tinctures, suspensions, syrups and emulsions. The compounds of this invention may also be administered intravenously, intraperitoneally, subcutaneously, or intramuscularly, all using dosage forms well known to those skilled in the pharmaceutical arts. The compounds can be administered alone, but generally will be administered with a pharmaceutical carrier selected upon the basis of the chosen route of administration and standard pharmaceutical practice. Compounds of this invention can also be administered in intranasal form by topical use of suitable intranasal vehicles, or by transdermal routes, using transdermal skin patches. When compounds of this invention are administered transdermally the dosage will be continuous throughout the dosage regimen.
The dosage and dosage regimen and scheduling of a compounds of the present invention must in each case be carefully adjusted, utilizing sound professional judgment and considering the age, weight and condition of the recipient, the route of administration and the nature and extent of the disease condition. In accordance with good clinical practice, it is preferred to administer the instant compounds at a concentration level which will produce effective beneficial effects without causing any harmful or untoward side effects.
Synthesis
Compounds of the present invention may be synthesized according to the general schema provided below. Variables provided in the schema below are defined in accordance with the description of compounds of the above Formulae unless otherwise specified.
A preferred method for the preparation of trans-cyclopentanes of Formula I is illustrated in Scheme 1. An appropriately substituted indole is condensed with a appropriately substituted unsaturated ketone in the presence of a catalyst such as ytterbium triflate hexahydrate to an indolyl ketone intermediate 1. Ketone 1 is then reductively condensed with an appropriately substituted amine in the presence of reagents such as sodium cyanoborohydride, sodium triacetoxyborohydride, or the like, to give a 3-indolyl cyclopentyl amine of Formula I.
If desired, the intermediate Ketone 1 can be enzymatically resolved as described in Scheme 2. Racemic ketone 1 is incubated under appropriate conditions with an appropriate enzyme to selectively reduce the undesired ketone enantiomer to alcohol, 2. Alternatively, the desired ketone enantiomer can be selectively reduced to the alcohol 2. The resulting mixture can be separated by chromatography, recrystallization, or other methods know to those skilled in the art to give resolved ketone and resolved alcohol. The separated alcohol, 2, can be oxidized using reagents such as oxalyl chloride/DMSO, PCC, PDC, or the like, to give the opposite ketone enantiomer. Alternatively when the undesired ketone enantiomer is reduced to alcohol 2, the mixture can be reductively condensed with an appropriately substituted amine in the presence of reagents such as sodium cyanoborohydride, sodium triacetoxyborohydride, or the like, to give a 3-indolyl cyclopentyl amine of Formula I which is then separated from the undesired alcohol 2.
Another preferred method for the resolution of ketone intermediates 1 is illustrated in Scheme 3. Racemic ketone 1 is condensed with an optically active diol, such as (SS)-(−)-hydrobenzoin, to give a diastereomeric ketal intermediate 3. The single diastereomer of the ketal can be separated by methods known to those skilled in the art such as chromatography or recrystallization. Subsequent cleavage of the single diastereomer, 4, by hydrolysis, catalytic hydrogenation, or the like, provides resolved ketone intermediate 1.
INTERMEDIATES
Example 1
3-(3-oxocyclopentyl)-1H-indole-5-carbonitrile
2-Cyclopenten-1-one (4.1 g, 4.2 mL, 50 mMol) was added to a stirred solution of 5-cyanoindole (1.42 g, 10 mMol) and ytterbium triflate hexahydrate (124 mg, 0.2 mMol) in acetonitrile (15 mL). After stirring at room temperature for 7d, the reaction was concentrated to an oil and diluted with ether. The red oily mixture was filtered through celite and the filtrate was concentrated in vacuo. The crude product was purified by flash chromatography on silica gel (35 g) using a gradient of 20–35% ethyl acetate in hexane. Pure product fractions were concentrated and dried under high vacuum to give 3-(3-oxocyclopentyl)-1H-indole-5-carbonitrile (1.55 g, 69%). 1 H NMR (500 MHz, CDCl 3 ) δ 8.41 (1 H, bs), 7.99 (1 H, s), 7.45 (2 H, m), 7.12 (1 H, dd, J=2.44, 0.92 Hz), 3.72 (1 H, m), 2.77 (1 H, dd, J=7.63, 18.31 Hz), 2.56 (1 H, m), 2.40 (3 H, m), 2.10 (1 H, m). MS m/e 223.2 (M−H) + . Anal. calcd. for C 14 H 12 N 2 O: C, 74.98; H, 5.39; N, 12.49. Found: C, 74.75; H, 5.50; N, 12.23.
Example 2
3-(5-fluoro-1H-indol-3-yl)-cyclopentanone
The method given in Example 1, using 5-fluoroindole (35.3 mMol), gave 3-(5-fluoro-1H-indol-3-yl)-cyclopentanone (1.29 g, 84%). 1 H NMR (500 MHz, CDCl 3 ): δ 8.03 (1 H, bs), 7.30 (1 H, dd, J=8.85, 4.27), 7.26 (1 H, dd, J=9.46, 2.44), 7.04 (1 H, d, J=2.14), 6.97 (1 H, dt, J=8.85, 2.44), 3.66 (1 H, m), 2.75 (1 H, dd, J=7.32, 18.31 Hz), 2.53 (1 H, m), 2.42 (2 H, m), 2.34 (1 H, m), 2.11 (1 H, m). MS m/e 216.04 (M−H) + . Anal. calcd. for C 13 H 12 NOF: C, 71.87; H, 5.56; N, 6.44. Found: C, 71.97; H, 5.69; N, 6.31.
Example 3
3-(4-Fluoro-1H-indol-3-yl)-cyclopentanone
By the method of Example 1, using 4-fluoroindole (1.35 g, 10.0 mMol) as starting material, 3-(4-fluoro-1H-indol-3-yl)-cyclopentanone (700 mg, 32%) was obtained. 1 H NMR (500 MHz, CDCl 3 ) δ ppm 2.09 (m, 1 H) 2.38 (m, 3 H) 2.51 (m, 1 H) 2.74 (dd, J=18.16, 7.78 Hz, 1 H) 3.81 (m, 1 H) 6.77 (dd, J=11.14, 7.78 Hz, 1 H) 6.94 (d, J=2.14 Hz, 1 H) 7.11 (m, 2 H) 8.13 (s, 1 H). MS m/e 216.2 (M−H) − . Anal. calcd. for C 13 H 12 NOF: C, 71.87; H, 5.56; N, 6.44. Found: C, 71.90; H, 5.63; N, 6.29.
Example 4
3-(4-Bromo-1H-indol-3-yl)-cyclopentanone
By the method of Example 1, using 4-bromoindole (1.96 g, 10.0 mMol) as starting material, 3-(4-bromo-1H-indol-3-yl)-cyclopentanone (405 mg, 15%) was obtained. 1 H NMR (400 MHz, CDCl 3 ) δ ppm 2.09 (m, 1 H) 2.38 (m, 3 H) 2.56 (m, 1 H) 2.85 (dd, J=18.22, 7.46 Hz, 1 H) 4.32 (m, 1 H) 7.03 (m, 2 H) 7.30 (dd, J=7.46, 5.99 Hz, 2 H) 8.15 (s, 1 H). MS m/e 276.1 (M−H) − . Anal. calcd. for C 13 H 12 NOBr: C, 56.13; H, 4.34; N, 5.03. Found: C, 56.23; H, 4.34; N, 5.14.
Example 5
3-(5-Chloro-1H-indol-3-yl)-cyclopentanone
By the method of Example 1, using 5-chloroindole (1.52 g, 10.0 mMol) as starting material, 3-(5-chloro-1H-indol-3-yl)-cyclopentanone (1.09 g, 47%) was obtained. 1 H NMR (400 MHz, CDCl3) δ ppm 2.09 (m, 1 H) 2.38 (m, 3 H) 2.52 (m, 1 H) 2.74 (dd, J=18.10, 7.58 Hz, 1 H) 3.66 (m, 1 H) 7.01 (d, J=1.71 Hz, 1 H) 7.16 (dd, J=8.80, 1.96 Hz, 1 H) 7.29 (d, J=9.29 Hz, 1 H) 7.58 (d, J=1.96 Hz, 1 H) 8.07 (s, 1 H). MS m/e 232.2 (M−H) − . Anal. calcd. for C 13 H 12 NOCl: C, 66.81; H, 5.17; N, 5.99. Found: C, 67.10; H, 5.23; N, 5.75.
Example 6
3-(5-Bromo-1H-indol-3-yl)-cyclopentanone
By the method of Example 1, using 5-bromoindole (1.96 g, 10.0 mMol) as starting material, 3-(5-bromo-1H-indol-3-yl)-cyclopentanone (1.30 g, 47%) was obtained. 1 H NMR (500 MHz, CDCl3) δ ppm 2.08 (m, 1 H) 2.38 (m, 3 H) 2.52 (m, 1 H) 2.74 (dd, J=18.16, 7.48 Hz, 1 H) 3.65 (m, 1 H) 6.98 (d, J=2.14 Hz, 1 H) 7.24 (d, J=8.55 Hz, 1 H) 7.29 (dd, J=8.54, 1.84 Hz, 1 H) 7.74 (d, J=1.22 Hz, 1 H) 8.12 (s, 1 H). MS m/e 276.2 (M−H) − . Anal. calcd. for C 13 H 12 NOCl: C, 56.13; H, 4.34; N, 5.03. Found: C, 56.18; H, 4.36; N, 4.97.
Example 7
3-(5-Iodo-1H-indol-3-yl)-cyclopentanone
By the method of Example 1, using 5-iodoindole (2.43 g, 10.0 mMol) as starting material, 3-(5-iodo-1H-indol-3-yl)-cyclopentanone (1.34 g, 41%) was obtained. 1 H NMR (500 MHz, CDCl 3 ) δ ppm 2.08 (m, 1 H) 2.37 (m, 3 H) 2.52 (m, 1 H) 2.73 (dd, J=18.31, 7.32 Hz, 1 H) 3.64 (m, 1 H) 6.94 (d, J=2.14 Hz, 1 H) 7.15 (d, J=8.55 Hz, 1 H) 7.45 (dd, J=8.55, 1.53 Hz, 1 H) 7.95 (d, J=0.92 Hz, 1 H) 8.09 (s, 1 H). MS m/e 324.1 (M−H) − . Anal. calcd. for C 13 H 12 NOI: C, 48.02; H, 3.72; N, 4.30. Found: C, 48.01; H, 3.71; N, 4.25.
Example 8
3-(6-Fluoro-1H-indol-3-yl)-cyclopentanone
By the method of Example 1, using 6-fluoroindole (1.35 g, 10.0 mMol) as starting material, 3-(6-fluoro-1H-indol-3-yl)-cyclopentanone (1.6 g, 75%) was obtained. 1 H NMR (500 MHz, CDCl3) δ ppm 2.10 (ddd, J=17.70, 12.51, 8.85 Hz, 1 H) 2.38 (m, 3 H) 2.52 (m, 1 H) 2.74 (dd, J=18.31, 7.32 Hz, 1 H) 3.68 (m, 1 H) 6.90 (td, J=9.16, 2.44 Hz, 1 H) 6.95 (d, J=1.53 Hz, 1 H) 7.05 (dd, J=9.61, 2.29 Hz, 1 H) 7.51 (dd, J=8.55, 5.19 Hz, 1 H) 8.05 (s, 1 H). MS m/e 216.2 (M−H) − . Anal. calcd. for C 13 H 12 NOF.0.35H 2 O: C, 69.85; H, 5.73; N, 6.27. Found: C, 69.95; H, 5.73; N, 5.94.
Example 9
3-(6-Chloro-1H-indol-3-yl)-cyclopentanone
By the method of Example 1, using 6-chloroindole (1.52 g, 10.0 mMol) as starting material, 3-(6-chloro-1H-indol-3-yl)-cyclopentanone (1.01 g, 43%) was obtained. 1 H NMR (500 MHz, CDCl 3 ) δ ppm 2.09 (ddd, J=17.85, 12.51, 9.00 Hz, 1 H) 2.38 (m, 3 H) 2.52 (m, 1 H) 2.74 (dd, J=18.16, 7.48 Hz, 1 H) 3.68 (ddd, J=16.25, 8.93, 6.87 Hz, 1 H) 6.97 (dd, J=2.29, 0.76 Hz, 1 H) 7.10 (dd, J=8.55, 1.83 Hz, 1 H) 7.36 (d, J=1.53 Hz, 1 H) 7.51 (d, J=8.55 Hz, 1 H) 8.06 (s, 1 H). MS m/e 232.2 (M−H) − . Anal. calcd. for C 13 H 12 NOCl: C, 66.81; H, 5.17; N, 5.99. Found: C, 66.74; H, 5.06; N, 5.87.
Example 10
3-(6-Bromo-1H-indol-3-yl)-cyclopentanone
By the method of Example 1, using 6-bromoindole (1.96 g, 10.0 mMol) as starting material, 3-(6-bromo-1H-indol-3-yl)-cyclopentanone (0.95 g, 34%) was obtained. 1 H NMR (500 MHz, CDCl 3 ) δ ppm 2.09 (ddd, J=17.78, 12.44, 9.16 Hz, 1 H) 2.38 (m, 3 H) 2.52 (m, 1 H) 2.74 (dd, J=18.31, 7.63 Hz, 1 H) 3.68 (m, 1 H) 6.96 (d, J=1.83 Hz, 1 H) 7.23 (dd, J=8.39, 1.68 Hz, 1 H) 7.47 (d, J=8.54 Hz, 1 H) 7.53 (d, J=1.83 Hz, 1 H) 8.01 (br s, 1 H). MS m/e 276.1 (M−H) − . Anal. calcd. for C 13 H 12 NOBr: C, 56.13; H, 4.34; N, 5.03. Found: C, 56.26; H, 4.35; N, 4.88.
Example 11
3-(7-Fluoro-1H-indol-3-yl)-cyclopentanone
By the method of Example 1, using 7-fluoroindole (405 mg, 3.0 mMol) as starting material, 3-(7-fluoro-1H-indol-3-yl)-cyclopentanone (526 mg, 81%) was obtained. 1 H NMR (500 MHz, CDCl 3 ) δ ppm 2.13 (ddd, J=17.85, 12.36, 9.16 Hz, 1 H) 2.40 (m, 3 H) 2.54 (m, 1 H) 2.77 (dd, J=18.16, 7.48 Hz, 1 H) 3.70 (m, 1 H) 6.94 (dd, J=11.29, 7.63 Hz, 1 H) 7.05 (m, 2 H) 7.39 (d, J=7.63 Hz, 1 H) 8.18 (br s, 1 H). MS m/e 216.1 (M−H) − .
Example 12
3-(7-Chloro-1H-indol-3-yl)-cyclopentanone
By the method of Example 1, using 7-chloroindole (1.0 g, 6.6 mMol) as starting material, 3-(7-chloro-1H-indol-3-yl)-cyclopentanone (479 mg, 31%) was obtained. 1 H NMR (400 MHz, CDCl 3 ) δ ppm 2.11 (ddd, J=17.85, 12.35, 9.17 Hz, 1 H) 2.39 (m, 3 H) 2.53 (m, 1 H) 2.76 (dd, J=17.97, 7.46 Hz, 1 H) 3.69 (ddd, J=16.38, 9.05, 6.85 Hz, 1 H) 7.04 (dd, J=2.69, 1.22 Hz, 1 H) 7.08 (2s, 1 H) 7.22 (dd, J=7.70, 0.86 Hz, 1 H) 7.52 (d, J=8.07 Hz, 1 H) 8.26 (s, 1 H). MS m/e 232.1 (M−H) − . Anal. calcd. for C 13 H 12 NOCl: C, 66.81; H, 5.17; N, 5.99. Found: C, 66.78; H, 5.19; N, 6.03.
Example 13
3-(7-Bromo-1H-indol-3-yl)-cyclopentanone
By the method of Example 1, using 7-bromoindole (1.09 g, 5.56 mMol) as starting material, 3-(7-bromo-1H-indol-3-yl)-cyclopentanone (527 mg, 34%) was obtained. 1 H NMR (500 MHz, CDCl 3 ) δ ppm 2.11 (ddd, J=18.08, 12.44, 9.16 Hz, 1 H) 2.39 (m, 3 H) 2.53 (m, 1 H) 2.76 (dd, J=18.16, 7.48 Hz, 1 H) 3.69 (m, 1 H) 7.02 (t, J=7.78 Hz, 1 H) 7.05 (d, J=2.44 Hz, 1 H) 7.37 (d, J=7.63 Hz, 1 H) 7.56 (d, J=7.93 Hz, 1 H) 8.18 (br s, 1 H). MS m/e 276.1 (M−H) − . Anal. calcd. for C 13 H 12 NOBr: C, 56.13; H, 4.13; N, 5.03. Found: C, 56.02; H, 4.14; N, 4.83.
Example 14
Chiral HPLC Resolution of 3-(3-Oxocyclopentyl)-1H-indole-5-carbonitrile
The (1S)- and (1R)-enantiomers of 3-(3-oxocyclopentyl)-1H-indole-5-carbonitrile were resolved by chiral HPLC on a Chiral Technologies Chiralcel OD column (20μ, 50×500 mm) using a mobile phase gradient of ethanol/hexane (10–100% containing 0.01% diethylamine). Flow rate was varied over the gradient from 60–50 mL/min. The first isomer to elute was (1S)-3-(3-oxocyclopentyl)-1H-indole-5-carbonitrile ([α] 25 −24.4 (589 nm, c 2.62 mg/mL, MeOH); t R 10.8 min*). The second isomer to elute was (1R)-3-(3-oxocyclopentyl)-1H-indole-5-carbonitrile ([α] 25 +10.5 (589 nm, c 2.64 mg/mL, EtOH); t R 12.5 min*). *Chiral Technologies Chiralcel OD analytical column (4.6×25 mm), 15% ethanol in hexane containing 0.1% diethylamine, flow rate 1.0 mL/min.
Example 15
Enzymatic resolution of 3-(3-Oxocyclopentyl)-1H-indole-5-carbonitrile
Alternatively, (1S)-3-(3-oxocyclopentyl)-1H-indole-5-carbonitrile was obtained by enzymatic resolution of racemic 3-(3-oxocyclopentyl)-1H-indole-5-carbonitrile utilizing ketoreductase KRED-1004 (Biocatalytics, Inc., Pasadena, Calif.) in the presence of isopropanol as co-substrate and NADPH as cofactor. The 1 L reaction mixture consisted of 10 mM potassium phosphate buffer (pH 6.0), 15% methanol, 2% isopropanol, 50 mg NADPH, 50 mg KRED-1004 and 500 mg 3-(3-oxocyclopentyl)-1H-indole-5-carbonitrile in water. After incubating at 30° C., 75 rpm for 3 d, the reaction reached completion by RP-HPLC analysis. The reaction mixture was then extracted with 1 L of ethyl acetate to afford 516 mg mixture of (1S)-3-(3-oxocyclopentyl)-1H-indole-5-carbonitrile and (1R,3S)-3-(3-hydroxy-cyclopentyl)-1H-indole-5-carbonitrile. The enantio excess (ee) of (1S)-3-(3-oxocyclopentyl)-1H-indole-5-carbonitrile was determined to be greater than 95% by chiral HPLC.
The ketone/alcohol mixture (2.4 g) was purified by flash chromatography on 110 g silica gel with a step gradient of 0, 1, and 2% methanol in methylene chloride. The two components were concentrated and dried under high vacuum to yield (1S)-3-(3-oxocyclopentyl)-1H-indole-5-carbonitrile (1.1 g, 46%) and (1R,3S)-3-(3-hydroxycyclopentyl)-1H-indole-5-carbonitrile (0.94 g, 39%). (The configuration of the alcohol was determined to be cis by a NOE method.)
Analytical data for (1S)-3-(3-oxocyclopentyl)-1H-indole-5-carbonitrile: 1 H NMR (500 MHz, CDCl 3 ) δ 8.38 (1 H, bs), 7.98 (1 H, s), 7.45 (2 H, m), 7.11 (1 H, dd, J=2.44, 0.91 Hz), 3.71 (1 H, m), 2.77 (1 H, dd, J=7.63, 18.31 Hz), 2.56 (1 H, m), 2.40 (3 H, m), 2.10 (1 H, m). MS m/e 223.2 (M−H) + . [α] 25 −22.3 (589 nm, c 1.54 mg/mL, MeOH).
Analytical data for (1R,3S)-3-(3-hydroxycyclopentyl)-1H-indole-5-carbonitrile: 1 H NMR (500 MHz, CDCl 3 ) δ 8.26 (1 H, bs), 8.04 (1 H, s), 7.40 (2 H, m), 7.15 (1 H, dd, J=2.44, 0.91 Hz), 4.52 (1 H, m), 3.31 (1 H, p, J=8.24), 2.55 (1 H, m), 2.15 (1 H, m), 1.98 (2 H, m), 1.83 (1 H, m), 1.76 (1 H, m). MS m/e 225.2 (M−H) + . Anal. calcd. for C 14 H 14 N 2 O.0.65 H 2 O: C, 70.66; H, 6.48; N, 11.77. Found: C, 70.87; H, 6.80; N, 11.44. [α] 25 −13.8 (589 nm, c 1.54 mg/mL, MeOH).
Example 16
Separation of (3S)-3-(5-fluoro-1H-indol-3-yl)-cyclopentanone from its racemic mixture
A solution of racemic 3-(5-fluoro-1H-indol-3-yl)-cyclopentanone (5 g, 23 mMol), (S,S)-(−) hydrobenzoin (5 g, 23 mMol) and p-toluenesulfonic acid monohydrate (0.44 g, 2.3 mMol) in of benzene (150 mL) was heated to reflux under a Dean-Stark trap for 40 min. The reaction mixture was concentrated and the residue was purified by chromatography on silica gel using ethyl acetate/hexane (0%–20%) as the eluent. The pure fractions were concentrated to give a mixture of two diastereomers (5 g, 53%). The mixture was dissolved in ethyl acetate (5 mL) and diluted with hexane (30 mL). The resulting solution was cooled in a refrigerator for 2 d to give the crystalline single diastereomer, (3S)-3-(5-fluoro-1H-indol-3-yl)-cyclopentanone (S,S)-hydrobenzoin ketal (1.6 g, 86.8% de by chiral HPLC). [α] 25 −7.35 (589 nm, c 6.04 mg/mL, MeOH). 1 HNMR (500 MHz, CDCl 3 ) δ 1.98 (m, 1H); 2.36 (m,4H); 2.67 (m,1H); 3.50 (m, 1H); 4.75 (s, 2H); 6.94 (t, 1H); 7.09 (s, 1H); 7.30 (m, 11H); 7.93 (s, 1H). M−1=412.
A solution of the above ketal (207 mg, 0.5 mMol) in methanol (35 mL) and 3N HCl (1 mL) was stirred for 18 hr. The solution was concentrated and the residue was dissolved in ethyl acetate. The solution was washed with aqueous sodium bicarbonate, washed with brine, and dried over magnesium sulfate. The solution was concentrated to give the crude product which was purified by chromatography on silica gel using ethyl acetate/hexane (0–50%) as the eluent to give (3S)-3-(5-fluoro-1H-indol-3-yl)-cyclopentanone (68 mg, 63%, 81% ee by chiral HPLC. [α] 25 −10.67 (589 nm, c 12.36 mg/mL, MeOH). 1 H NMR (500 MHz, CDCl 3 ) δ 2.09 (m, 1H); 2.50 (m,4H); 2.80 (m, 1H); 3.64 (m, 1H); 6.96 (m, 1H); 7.02 (d, 1H); 7.26 (m, 2H); 8.20 (s,1H). M+1=218.
Example 17
1-methyl-3-(3-oxo-cyclopentyl)-1H-indole-5-carbonitrile
3-(3-oxocyclopentyl)-1H-indole-5-carbonitrile (11.21 g, 0.05 mMol) was dissolved in anhydrous DMSO (30 mL) and added dropwise to a suspension of sodium hydride (2.25 g, 0.055 mMol, 60% in mineral oil) in dry DMSO (50 mL) under nitrogen at 25–30° C. The reaction was heated to 40° C. for 15 min, then cooled to room temperature. Methyl iodide (3.42 mL, 0.055 mMol) was added dropwise, maintaining reaction temperature at 25–30° C. with an external ice water bath. After stirring for 2 h at room temperature, the reaction was poured into 1 L ice water. The tan solid was filtered, washed with H 2 O, dissolved in ethyl acetate (750 mL), extracted with H 2 O (500 mL) and brine (500 mL), and dried over sodium sulfate. The ethyl acetate extract was concentrated in vacuo and the product was purified by chromatography on silica gel with a 10% step gradient of 25–45% ethyl acetate in hexane. Pure product fractions were concentrated in vacuo and dried under high vacuum to give 1-methyl-3-(3-oxo-cyclopentyl)-1H-indole-5-carbonitrile (8.52 g, 72%). 1 H NMR (500 MHz, CDCl 3 ) δ 7.95 (1 H, s), 7.46 (1 H, dd, J=8.54, 1.22), 7.34 (1 H, d, J=8.54), 6.94 (1 H, s), 3.78 (3 H, s), 3.69 (1 H, m), 2.74 (1 H, dd, J=7.63, 18.01 Hz), 2.53 (1 H, m), 2.38 (3 H, m), 2.06 (1 H, m). MS m/e 239.3 (M+H) + . Anal. calcd. for C 15 H 14 N 2 O: C, 75.60; H, 5.92; N, 11.75. Found: C, 75.31; H, 5.86; N, 11.55. IR (KBr) 2219, 1728 cm −1 .
Example 18
1-Ethyl-3-(3-oxo-cyclopentyl)-1H-indole-5-carbonitrile
1-Ethyl-3-(3-oxo-cyclopentyl)-1H-indole-5-carbonitrile (1.96 g, 70%) was prepared by the previous example on a 10 mMol scale using iodoethane. 1 H NMR (500 MHz, CDCl 3 ) δ 7.94 (1 H, s), 7.43 (1 H, dd, J=8.55, 1.53), 7.35 (1 H, d, J=8.55), 7.01 (1 H, s), 4.15 (2 H, q, J=7.32), 3.68 (1 H, m), 2.73 (1 H, dd, J=7.63, 18.00 Hz), 2.52 (1 H, m), 2.36 (3 H, m), 2.07 (1 H, m), 1.45 (3 H, t, J=7.32). MS m/e 253.4 (M+H) + . Anal. calcd. for C 16 H 16 N 2 O.0.14 EtOAc: C, 75.16; H, 6.52; N, 10.59. Found: C, 74.90; H, 6.15; N, 10.68. IR (KBr) 2218, 1739, 2974 cm −1 .
Synthesis of Compounds of Formula (I)
Example 19
General Example for the synthesis of 3-(3-alkylaminocyclopentyl)-1H-indole-5-carbonitriles and 3-(3-dialkylaminocyclopentyl)-1H-indole-5-carbonitriles
3-(3-oxocyclopentyl)-1H-indole-5-carbonitrile, 1-methyl-3-(3-oxo-cyclopentyl)-1H-indole-5-carbonitrile, or 1-ethyl-3-(3-oxo-cyclopentyl)-1H-indole-5-carbonitrile (0.5 mMol) and the amine (R 2 R 3 NH, 5.0 mMol) were dissolved in ethanol to a final volume of 5 mL. After stirring for 15 min, sodium triacetoxyborohydride (430 mg, 2.0 mMol) was added and the reaction stirred for 3 h. (In the case of primary amines (R 2 NH 2 ), the reactions were catalyzed by the addition of 3 drops glacial HOAc. In some cases, additional reaction time was necessary for completion.) The reaction was then diluted with water (10 mL) and extracted three times with ethyl acetate (10 mL). The organic extracts were dried over sodium sulfate and concentrated in vacuo. The residue was purified by preparative reverse phase HPLC to give the product as an oily trifluoroacetic acid salt of cis/trans diastereomers. Where indicated, the free base was isolated by extraction of the TFA salt from saturated sodium carbonate solution with ethyl acetate.
The following compounds of Formula (Ex-19) were prepared by the above method:
Yield
LCMS t R ,
HPLC
Cmpd.
R 1
R 2
R 3
Form
(%)
MH +
min.
method*
1
H
H
Me
TFA
50
240.12
0.870
A
2
H
H
Et
TFA
63
254.11
0.903
A
3
H
Me
Me
TFA
95
254.12
0.867
A
4
H
Me
Et
TFA
36
268.13
0.903
A
5
H
Et
Et
TFA
35
282.15
0.980
A
6
H
—(CH 2 ) 4 —
TFA
42
280.13
0.953
A
7
H
Base
43
328.24
1.220
B
8
H
Base
44
342.20
1.293
B
9
H
H
—(CH 2 ) 2 Ph
Base
50
330
1.673
C
10
H
Me
—(CH 2 ) 2 Ph
Base
54
344
1.643
C
11
H
—(CH 2 ) 2 —O—(CH 2 ) 2 —
Base
27
296
1.093
C
12
H
Me
—CH 2 Ph
Base
80
330
2.097
C
13
H
H
—CH 2 Ph
Base
43
316
1.590
C
14
H
—(CH 2 ) 5 —
Base
79
294
1.840
C
15
H
n-Pr
n-Pr
Base
29
310
2.007
C
16
H
H
n-Pr
Base
40
268
1.887
C
17
Me
H
Me
Base
36
254.24
1.163
B
18
Me
H
Et
Base
48
268.26
1.203
B
19
Me
H
—CH 2 Ph
Base
47
330.24
1.400
B
20
Me
H
—(CH 2 ) 2 Ph
Base
41
344.26
1.473
B
21
Me
Me
Me
Base
67
268.26
1.150
B
22
Me
Me
Et
Base
69
282.22
1.163
B
23
Me
Et
Et
Base
29
296.31
1.220
B
24
Me
—(CH 2 ) 4 —
Base
76
294.24
1.187
B
25
Me
—(CH 2 ) 5 —
Base
80
308.22
1.203
B
26
Me
—(CH 2 ) 2 —O—(CH 2 ) 2 —
Base
60
310.20
1.143
B
27
Me
Me
—CH 2 Ph
Base
76
344.20
1.357
B
28
Me
Me
—(CH 2 ) 2 Ph
Base
70
358.30
1.477
B
29
Me
H
n-Pr
Base
10
282.29
1.300
B
30
Me
n-Pr
n-Pr
Base
58
324.30
1.340
B
31
Et
Me
Bn
Base
30
358
1.743
C
32
Et
Me
Me
Base
27
282
1.460
C
*HPLC Methods:
A. Gradient conditions for YMC ODS-A C18 S7 3.0 × 50 mm:
Solvent A 10% MeOH-90% H2O-0.1% TFA
Solvent B 90% MeOH-10% H2O-0.1% TFA
0–100% B, 2 m gradient time, 1 m hold at 100% B.
Flow rate 5 mL/min.
B. Gradient conditions for XTERRA C18 S5 4.6 × 50 mm:
Solvent A 10% MeOH-90% H2O-0.1% TFA
Solvent B 90% MeOH-10% H2O-0.1 TFA
0–100% B, 2 m gradient time, 1 m hold at 100% B.
Flow rate 5 mL/min.
C. Gradient conditions for XTERRA S7 3.0 × 50 mm:
Solvent A 10% MeOH-90% H2O-0.1% TFA
Solvent B 90% MeOH-10% H2O-0.1% TFA
0–100% B, 3 min. gradient time, 1 mim hold at 100% B.
Flow rate 4 mL/min.
Example 20
General Example for synthesis of 3-(5-Fluoro-1H-indol-3-yl)-cyclopentyl-dialkylamines
3-(5-fluoro-1H-indol-3-yl)-cyclopentanone (0.5 mMol) and amine (R 2 R 3 NH, 5.0 mMol) were dissolved in EtOH to a final volume of 5 mL. After stirring for 15 min., sodium triacetoxyborohydride (430 mg, 2.0 mMol) was added and the reaction continued for 2–3 d. In some cases, additional reaction time was necessary for completion.) The reaction was then diluted with 10 mL water and extracted three times with 10 mL EtOAc. The organic layers were pooled, dried over Na 2 SO 4 , and concentrated under vacuum. Purification by preparative reverse phase HPLC gave the product as an oily trifluoroacetic acid salt.
The above procedure was followed for each of the following compounds of Formula (Ex-20):
Yield
LCMS
Cmpd.
R 1
R 2
R 3
Form
(%)
MH +
t R , min.*
33
H
Me
Me
TFA
71
247.2
0.943
34
H
Et
Me
TFA
72
261.2
0.990
35
H
Et
Et
TFA
63
275.2
1.013
36
H
—(CH 2 ) 4 —
TFA
53
273.2
0.993
*HPLC Method:
YMC ODS-A C18 57 3.0 × 50 mm column;
Solvent A 10% MeOH-90% H2O-0.1% TFA
Solvent B 90% MeOH-10% H2O-0.1% TFA
0–100% B, 2 m gradient time, 1 m hold at 100% B.
Flow rate 5 mL/min.
Example 21
Specific procedure for the synthesis of 3-(3-Dimethylaminocyclopentyl)-1H-indole-5-carbonitrile
3-(3-oxocyclopentyl)-1H-indole-5-carbonitrile (2.24 g, 10 mMol) and dimethylamine (2.0 M solution in THF, 50 mL, 100 mMol) were dissolved in EtOH (150 mL). After stirring for 15 min, sodium triacetoxyborohydride (8.50 g, 40 mMol) was added and the reaction stirred for 4 h. The reaction was then diluted with water (100 mL) and made acidic (pH 3) with HCl (6 M). The reaction was then adjusted to pH 10 with sodium carbonate. It was extracted three times with ethyl acetate (100 mL) and the organic extracts were dried over sodium sulfate, concentrated in vacuo, and dried under high vacuum to give 3-(3-dimethylaminocyclopentyl)-1H-indole-5-carbonitrile (Compound 3, 2.5 g, 100%) as mixture of cis/trans diastereomers. 1 H NMR (500 MHz, d4-MeOH) δ 8.02 (0.7 H s), 7.99 (0.3 H, s), 7.46 (0.4 H, s), 7.44 (0.6 H, s), 7.35 (1 H, dd, J=8.55 1.53), 7.24 (0.7 H, s), 7.21 (0.3 H, s), 3.49 (0.4 H, m), 3.37 (0.6 H, m), 2.92 (0.3 H, m), 2.83 (0.7 H, m), 2.41 (0.7 H, m), 2.36 (6 H, s), 2.22 (1.3 H, m), 2.07 (1 H, m), 1.80 (2 H, m), 1.67 (1 H, m). MS m/e 254.2 (M+H) + , 252.2 (M−H) + . LCMS (YMC ODS-A C18 S7 3.0×50 mm) t R , 0.857 min., MH + 254.19.
Example 22
3-(4-Fluoro-1H-indol-3-yl)-cyclopentyl-dimethyl-amine
By the method of Example 21, using 3-(4-fluoro-1H-indol-3-yl)-cyclopentanone (217 mg, 1.0 mMol) as starting material, 3-(4-fluoro-1H-indol-3-yl)-cyclopentyl-dimethylamine (77 mg, 31%) was obtained. 1 H NMR (400 MHz, d 4 MeOH) δ ppm 1.90 (m, 4 H) 2.23 (m, 3 H) 2.54 (m, 1 H) 2.81 (m, 6 H) 3.57 (m, 2 H) 6.63 (m, 1 H) 7.07 (m, 3 H). LCMS (XTERRA C18 S5 4.6×50 mm) t R , 1.153 min., MH + 247.28.
Example 23
3-(4-Bromo-1H-indol-3-yl)-cyclopentyl-dimethyl-amine
By the method of Example 21, using 3-(4-bromo-1H-indol-3-yl)-cyclopentanone (278 mg, 1.0 mMol) as starting material, 3-(4-bromo-1H-indol-3-yl)-cyclopentyl-dimethylamine (131 mg, 43%) was obtained. 1 H NMR (500 MHz, d 4 MeOH) δ ppm 1.93 (m, 2 H) 2.27 (m, 3 H) 2.67 (m, 1 H) 2.87 (d, J=3.66 Hz, 6 H) 3.70 (m, 1 H) 4.06 (m, 1 H) 6.95 (t, J=7.93 Hz, 1 H) 7.17 (m, 1 H) 7.32 (m, 2 H). LCMS (XTERRA C18 S5 4.6×50 mm) t R , 1.373 min., MH + 307.19, 309.19.
Example 24
3-(5-Chloro-1H-indol-3-yl)-cyclopentyl-dimethyl-amine
By the method of Example 21, using 3-(5-chloro-1H-indol-3-yl)-cyclopentanone (234 mg, 1.0 mMol) as starting material, 3-(5-chloro-1H-indol-3-yl)-cyclopentyl-dimethylamine (83 mg, 32%) was obtained. 1 H NMR (400 MHz, d4MeOH) δ ppm 1.85 (m, 2 H) 2.28 (m, 3 H) 2.60 (m, 1 H) 2.84 (s, 6 H) 3.60 (m, 2 H) 7.03 and 7.05 (2d, J=1.96 Hz, 1 H) 7.12 and 7.15 (2s, 1 H) 7.27 and 7.29 (2s, 1 H) 7.52 and 7.54 (2d, J=1.83 Hz, 1 H). LCMS (XTERRA C18 S5 4.6×50 mm) t R , 1.260 min., MH + 263.24.
Example 25
3-(5-Bromo-1H-indol-3-yl)-cyclopentyl-dimethyl-amine
By the method of Example 21, using 3-(5-bromo-1H-indol-3-yl)-cyclopentanone (278 mg, 1.0 mMol) as starting material, 3-(5-bromo-1H-indol-3-yl)-cyclopentyl-dimethylamine (248 mg, 81%) was obtained. 1 H NMR (400 MHz, d4-MeOH) δ ppm 1.74 (m, 3 H) 2.11 (m, 3 H) 2.39 (s, 6 H) 2.93 (m, 1 H) 3.32 (m, 1 H) 7.06 (2s, 1 H) 7.13 (2t, J=1.71 Hz, 1 H) 7.22 (2s, 1 H) 7.66 (2d, J=1.47 Hz, 1 H). LCMS (XTERRA C18 S5 4.6×50 mm) t R , 1.307 min., MH + 307.21.
Example 26
3-(5-Iodo-1H-indol-3-yl)-cyclopentyl-dimethyl-amine
By the method of Example 21, using 3-(5-iodo-1H-indol-3-yl)-cyclopentanone (325 mg, 1.0 mMol) as starting material, 3-(5-iodo-1H-indol-3-yl)-cyclopentyl-dimethylamine (330 mg, 93%) was obtained. 1 H NMR (400 MHz, d4-MeOH) δ ppm 1.76 (m, 3 H) 2.12 (m, 3 H) 2.43 (2s, 6 H) 2.97 (m, 1 H) 3.32 (m, 1 H) 7.02 (2s, 1 H) 7.13 (2s, 1 H) 7.31 (2t, J=1.71 Hz, 1 H) 7.86 (2d, J=1.22 Hz, 1 H). LCMS (XTERRA C18 S5 4.6×50 mm) t R , 1.383 min., MH + 355.21.
Example 27
3-(6-Fluoro-1H-indol-3-yl)-cyclopentyl-dimethyl-amine
By the method of Example 21, using 3-(6-fluoro-1H-indol-3-yl)-cyclopentanone (217 mg, 1.0 mMol) as starting material, 3-(6-fluoro-1H-indol-3-yl)-cyclopentyl-dimethylamine (135 mg, 55%) was obtained. 1 H NMR (400 MHz, d4MeOH) δ ppm 1.77 (m, 3 H) 2.15 (m, 3 H) 2.49 (s, 6 H) 3.10 (m, 1 H) 3.38 (m, 1 H) 6.75 (m, 1 H) 7.00 (m, 2 H) 7.47 (ddd, J=8.68, 5.75, 5.62 Hz, 1 H). LCMS (XTERRA C18 S5 4.6×50 mm) t R , 1.103 min., MH + 247.29.
Example 28
3-(6-Chloro-1H-indol-3-yl)-cyclopentyl-dimethyl-amine
By the method of Example 21, using 3-(6-chloro-1H-indol-3-yl)-cyclopentanone (234 mg, 1.0 mMol) as starting material, 3-(6-chloro-1H-indol-3-yl)-cyclopentyl-dimethylamine (227 mg, 86%) was obtained. 1 H NMR (400 MHz, d4MeOH) δ ppm 1.74 (m, 3 H) 2.10 (m, 3 H) 2.35 (s, 6 H) 2.83 (m, 1 H) 3.33 (m, 1 H) 6.93 (dt, J=8.50, 2.35 Hz, 1 H) 7.03 (d, J=13.69 Hz, 1 H) 7.29 (d, J=1.47 Hz, 1 H) 7.48 (m, 1 H). LCMS (XTERRA C18 S5 4.6×50 mm) t R , 1.273 min., MH + 263.24.
Example 29
3-(6-Bromo-1H-indol-3-yl)-cyclopentyl-dimethyl-amine
By the method of Example 21, using 3-(6-bromo-1H-indol-3-yl)-cyclopentanone (278 mg, 1.0 mMol) as starting material, 3-(6-bromo-1H-indol-3-yl)-cyclopentyl-dimethylamine (280 mg, 91%) was obtained. 1 H NMR (400 MHz, d4MeOH) δ ppm 1.72 (m, 3 H) 2.14 (m, 3 H) 2.28 (d, J=4.40 Hz, 6 H) 2.75 (m, 1 H) 3.33 (m, 1 H) 7.01 (dd, J=14.18, 0.73 Hz, 1 H) 7.06 (ddd, J=8.50, 2.87, 1.83 Hz, 1 H) 7.44 (m, 2 H). LCMS (XTERRA C18 S5 4.6×50 mm) t R , 1.330 min., MH + 307.21.
Example 30
3-(7-Fluoro-1H-indol-3-yl)-cyclopentyl-dimethyl-amine
By the method of Compound 3, using 3-(7-fluoro-1H-indol-3-yl)-cyclopentanone (217 mg, 1.0 mMol) as starting material, 3-(7-fluoro-1H-indol-3-yl)-cyclopentyl-dimethylamine (144 mg, 59%) was obtained. 1 H NMR (400 MHz, d4MeOH) δ ppm 1.74 (m, 3 H) 2.17 (m, 3 H) 2.34 (d, J=2.20 Hz, 6 H) 2.84 (m, 1 H) 3.34 (m, 1 H) 6.77 (dd, J=11.13, 8.19 Hz, 1 H) 6.90 (m, J=10.39, 5.07, 4.83, 2.45 Hz, 1 H) 7.05 (d, J=15.16 Hz, 1 H) 7.33 (t, J=7.70 Hz, 1 H). LCMS (XTERRA C18 S5 4.6×50 mm) t R , 1.130 min., MH + 247.29.
Example 31
3-(7-Chloro-1H-indol-3-yl)-cyclopentyl-dimethyl-amine
By the method of Example 21, using 3-(7-chloro-1H-indol-3-yl)-cyclopentanone (234 mg, 1.0 mMol) as starting material, 3-(7-chloro-1H-indol-3-yl)-cyclopentyl-dimethylamine (238 mg, 90%) was obtained. 1 H NMR (400 MHz, d4MeOH) δ ppm 1.74 (m, 3 H) 2.17 (m, 3 H) 2.34 (d, J=1.71 Hz, 6 H) 2.86 (m, 1 H) 3.35 (m, 1 H) 6.94 (td, J=7.83, 2.45 Hz, 1 H) 7.07 (td, J=3.18, 1.22 Hz, 1 H) 7.11 (s, 1 H) 7.48 (td, J=7.46, 0.73 Hz, 1 H). LCMS (XTERRA C18 S5 4.6×50 mm) t R , 1.273 min., MH + 263.24.
Example 32
3-(7-Bromo-1H-indol-3-yl)-cyclopentyl-dimethyl-amine
By the method of Example 21, using 3-(7-bromo-1H-indol-3-yl)-cyclopentanone (278 mg, 1.0 mMol) as starting material, 3-(7-bromo-1H-indol-3-yl)-cyclopentyl-dimethylamine (286 mg, 93%) was obtained. 1 H NMR (400 MHz, d4MeOH) δ ppm 1.75 (m, 3 H) 2.17 (m, 3 H) 2.34 (d, J=1.96 Hz, 6 H) 2.85 (m, 1 H) 3.36 (m, 1 H) 6.89 (td, J=7.70, 2.20 Hz, 1 H) 7.07 and 7.11 (2s, 1 H) 7.22 (d, J=7.58 Hz, 1 H) 7.52 (td, J=7.34, 0.73 Hz, 1 H). LCMS (XTERRA C18 S5 4.6×50 mm) t R , 1.303 min., MH + 307.21.
Example 33
(1S,3R)-3-(3-Dimethylaminocyclopentyl)-1H-indole-5-carbonitrile
and
(1S,3S)-3-(3-Dimethylaminocyclopentyl)-1H-indole-5-carbonitrile
(1S)-3-(3-oxocyclopentyl)-1H-indole-5-carbonitrile (112 mg, 0.5 mMol) and dimethylamine (2.0 M solution in THF, 2.5 mL, 5.0 mMol) were dissolved in ethanol (2 mL). After stirring for 15 min, sodium triacetoxyborohydride (424 mg, 2.0 mMol) was added and the reaction continued for 2 h. The reaction was then diluted with water (5 mL) and made acidic (pH 3) with 6 M HCl. The reaction was then adjusted to pH 10 with sodium carbonate. It was extracted two times with ethyl acetate (50 mL) and the extracts were dried over sodium sulfate, concentrated in vacuo, and dried under high vacuum to give (1S)-3-(3-dimethylaminocyclopentyl)-1H-indole-5-carbonitrile (125 mg, 100%) as a cis/trans diastereomeric mixture. 1 H NMR (500 MHz, d4-MeOH) δ 8.02 (0.7 H s), 7.99 (0.3 H, s), 7.46 (0.3 H, s), 7.44 (0.7 H, s), 7.35 (1 H, dd, J=8.24 1.53), 7.24 (0.7 H, s), 7.20 (0.3 H, s), 3.49 (0.3 H, m), 3.36 (0.7 H, m), 2.83 (0.2 H, m), 2.75 (0.8 H, m), 2.39 (1 H, m), 2.31 (6 H, s), 2.21 (1 H, m), 2.05 (1 H, m), 1.80 (2 H, m), 1.66 (1 H, m).
The (3R)- and (3S)-diastereomers of (1S)-3-(3-dimethylaminocyclopentyl)-1H-indole-5-carbonitrile were resolved by chiral HPLC on a Chiral Technologies Chiralpak AD column (20μ, 50×500 mm) with a mobile phase of 10% ethanol in hexane-0.1% diethylamine at a flow rate of 75 mL/min. Analytical HPLC retention times refer to the following analytical chiral HPLC method: Chiralpak AD column, 4.6×250 mm with 10 μm packing. Solvents: 10% Ethanol/hexane (0.10% diethyl amine added in hexane as modifier). Flow: 1 mL/min for 20 min. UV detector at 280 nm. Loop volume: 20 μL. Injection load: 20 μL of a 1 mg/mL solution in ethanol.
Compound 48: (1S,3R)-3-(3-Dimethylaminocyclopentyl)-1H-indole-5-carbonitrile. 1 H NMR (500 MHz, d4-MeOH) δ 8.03 (1 H, d, J=0.92), 7.46 (1 H, d, J=8.55), 7.36 (1 H, dd, J=8.24 1.53), 7.25 (1 H, s), 3.39 (1 H, m), 2.81 (1 H, m), 2.42 (1 H, m), 2.35 (6 H, s), 2.22 (1 H, m), 2.08 (1 H, m), 1.86 (1 H, m), 1.77 (1 H, m), 1.67 (1 H, m). [α] 25 +12.95 (589 nm, c 1.58 mg/mL, EtOH). Analytical HPLC retention time 13 min.
Compound 49: (1S,3S)-3-(3-Dimethylaminocyclopentyl)-1H-indole-5-carbonitrile. 1 H NMR (500 MHz, d4-MeOH) δ 7.99 (1 H, s), 7.45 (1 H, d, J=8.54), 7.36 (1 H, dd, J=8.24 1.52), 7.21 (1 H, s), 3.49 (1 H, m), 2.85 (1 H, m), 2.32 (6 H, s), 2.25 (1 H, m), 2.12 (2 H, m), 1.99 (1 H, m), 1.80 (1 H, m), 1.66 (1 H, m). [α] 25 −26.50 (589 nm, c 1.58 mg/mL, EtOH). Analytical HPLC retention time 8.4 min.
Example 34
(1R,3S)-3-(3-Dimethylaminocyclopentyl)-1H-indole-5-carbonitrile
and
(1R,3R)-3-(3-Dimethylaminocyclopentyl)-1H-indole-5-carbonitrile
(1R)-3-(3-Oxocyclopentyl)-1H-indole-5-carbonitrile was reacted by the procedure used in Example 33, to give (1R)-3-(3-dimethylaminocyclopentyl)-1H-indole-5-carbonitrile (125 mg, 100%) as a cis/trans diastereomeric mixture. Yield: 1 H NMR (500 MHz, d4-MeOH) δ 8.02 (0.7 H s), 7.99 (0.3 H, s), 7.46 (0.3 H, s), 7.44 (0.7 H, s), 7.35 (1 H, dd, J=8.24 1.53), 7.24 (0.7 H, s), 7.20 (0.3 H, s), 3.49 (0.3 H, m), 3.36 (0.7 H, m), 2.83 (0.2 H, m), 2.75 (0.8 H, m), 2.39 (1 H, m), 2.31 (6 H, s), 2.21 (1 H, m), 2.05 (1 H, m), 1.80 (2 H, m), 1.66 (1 H, m).
The (3S)- and (3R)-diastereomers of (1R)-3-(3-dimethylaminocyclopentyl)-1H-indole-5-carbonitrile were separated by the method given in Example 33. Analytical HPLC retention times refer to the method give in Example 33.
Compound 50: (1R,3S)-3-(3-Dimethylaminocyclopentyl)-1H-indole-5-carbonitrile. 1 H δ (500 MHz, d4-MeOH) 8.03 (1 H, d, J=0.92), 7.46 (1 H, d, J=8.55), 7.36 (1 H, dd, J=8.24, 1.53), 7.25 (1 H, s), 3.38 (1 H, m), 2.86 (1 H, m), 2.43 (1 H, m), 2.38 (6 H, s), 2.23 (1 H, m), 2.09 (1 H, m), 1.86 (1 H, m), 1.78 (1 H, m), 1.68 (1 H, m). [α] 25 −8.12 (589 nm, c 1.71 mg/mL, EtOH). Analytical HPLC retention time 9.7 min.
Compound 51: (1R,3R)-3-(3-Dimethylaminocyclopentyl)-1H-indole-5-carbonitrile. 1 H NMR (500 MHz, d4-MeOH) δ 8.01 (1 H, s), 7.47 (1 H, d, J=8.24), 7.37 (1 H, dd, J=8.24 1.52), 7.23 (1 H, s), 3.53 (1 H, m), 3.10 (1 H, m), 2.47 (6 H, s), 2.29 (1 H, m), 2.19 (2 H, m), 2.07 (1 H, m), 1.84 (1 H, m), 1.73 (1 H, m). [α] 25 +13.99 (589 nm, c 1.5 mg/mL, EtOH). Analytical HPLC retention time 8.6 min.
Example 35
(1S,3S)-3-(5-Fluoro-1H-indol-3-yl)-cyclopentyl-dimethylamine
and
(1R,3S)-3-(5-Fluoro-1H-indol-3-yl)-cyclopentyl-dimethylamine
A solution of (3S)-3-(5-fluoro-1H-indol-3-yl)-cyclopentanone (290 mg, 1.34 mMol), dimethylamine (2.0 M solution in THF, 6.7 mL, 13.4 mMol) in ethanol (10 mL) was stirred for 15 min. Sodium triacetoxyborohydride (1.1 g, 5.4 mMol) was added and the reaction stirred for 1 h. The reaction was extracted three times with ethyl acetate/aqueous sodium bicarbonate solution. The ethyl acetate extracts were dried over magnesium sulfate and concentrated in vacuo to give (3S)-3-(5-fluoro-1H-indol-3-yl)-cyclopentyl-dimethylamine (400 mg, 100%) as a cis/trans diastereomeric mixture. The diastereomeric mixture was separated by preparative chiral HPLC using a Chiralpak AD column (50×500 mm with 20 μm packing) and 10% ethanol/hexane (0.1% diethylamine added in hexane as modifier) as the eluent at a flow rate of 60 mL/min for 50 min. The UV detector was set at 280 nm, the injection loop volume was 10 mL, and the injection load was 35–165 mg in a ethanol/hexane (1:1) solution.
Compound 52: (1S,3S)-3-(5-Fluoro-1H-indol-3-yl)-cyclopentyl-dimethylamine. 1 H NMR (MeOH-d4): δ 7.28 (dd, J=8.7, 4.5 Hz, 1H), 7.22 (dd, J=10.2, 2.4 Hz, 1H), 7.14 (s, 1H), 6.86 (dt, J=2.4 Hz, 1H), 3.68 (t, 1H), 3.55 (m, 1H), 2.84 (s, 6H), 2.28 (m, 4H), and 1.88 (m, 2H). FIMS: m/z 247.4 (M+H) + ; m/z 245.4 (M−H) − . [α] 25 −13.54 (589 nm, c 3.07 mg/mL, EtOH). >97% purity (reverse-phase HPLC); >99% purity with >99% ee (Chiralpak AD, 10% ethanol, 90% hexane (0.1% diethylamine), 0.5 mL/min, R t =12.1 min)
Compound 53: (1R,3S)-3-(5-Fluoro-1H-indol-3-yl)-cyclopentyl-dimethylamine. 1 H NMR (MeOH-d4): δ 7.27 (dd, J=9.0, 4.5 Hz, 1H), 7.24 (dd, J=8.7, 4.2 Hz, 1H), 7.21 (s, 1H), 6.86 (dt, J=9.3, 2.4 Hz, 1H), 3.35 (m, 1H), 3.18 (m, 1H), 2.58 (s, 6H), 2.47 (m, 1H), 2.18 (m, 2H), 1.86 (m, 2H), and 1.75 (q, J=10.5 Hz, 1H). FIMS: m/z 247.4 (M+H) + ; m/z 245.4 (M−H) − . [α] 25 +2.54 (589 nm, c 2.79 mg/mL, EtOH). >99% purity (reverse-phase HPLC); >99% purity with >98% ee (Chiralpak AD, 10% ethanol, 90% hexane (0.1% diethylamine), 0.5 mL/min, R t =15.7 min)
Example 36
(1R,3R)-3-(5-Fluoro-1H-indol-3-yl)-cyclopentyl-dimethylamine
and
(1S,3R)-3-(5-Fluoro-1H-indol-3-yl)-cyclopentyl-dimethylamine
Similarly, (3R)-3-(5-fluoro-1H-indol-3-yl)-cyclopentanone was reacted by the method in Example 35 on a 0.92 mMol scale to give 240 mg (100%) of (3R)-3-(5-fluoro-1H-indol-3-yl)-cyclopentyl-dimethylamine as a cis/trans diastereomeric mixture. The diastereomeric mixture was separated by preparative chiral HPLC using a Chiralpak AD column (50×500 mm with 20 μm packing) and 10% ethanol/hexane (0.1% diethylamine added in hexane as modifier) as the eluent at a flow rate of 60 mL/min for 50 min. The UV detector was set at 280 nm, the injection loop volume was 10 mL, and the injection load was 35–165 mg in a ethanol/hexane (1:1) solution.
Compound 54: (1R,3R)-3-(5-Fluoro-1H-indol-3-yl)-cyclopentyl-dimethylamine. 1 H NMR (MeOH-d4): δ 7.27 (dd, J=8.7, 4.5 Hz, 1H), 7.22 (dd, J=9.9, 2.4 Hz, 1H), 7.11 (s, 1H), 6.84 (dt, J=9.0, 2.4 Hz, 1H), 3.49 (t, 1H), 3.31 (m, 1H), 2.61 (s, 6H), 2.24 (m, 2H), 2.19 (q, J=15.3, 6.9 Hz, 2 H), and 1.80 (m, 2H). FIMS: m/z 247.4 (M+H) + ; m/z 245.4 (M−H) − . [α] 25 +14.03 (589 nm, c 1.71 mg/mL, EtOH). >89% purity (reverse-phase HPLC); >99% purity with >99% ee (Chiralpak AD, 10% ethanol, 90% hexane (0.1% diethylamine), 0.5 mL/min, R t =13.0 min)
Compound 55: (1S,3R)-3-(5-Fluoro-1H-indol-3-yl)-cyclopentyl-dimethylamine. 1 H NMR (MeOH-d4): δ 7.26 (dd, J=8.7, 4.5 Hz, 1H), 7.21 (dd, J=9.9, 2.4 Hz, 1H), 7.11 (s, 1H), 6.83 (dt, J=2.4 Hz, 1H), 3.31 (m, 1H), 2.90 (m, 1H), 2.41 (s, 6H), 2.39 (m, 1H), 2.20 (m, 1H), 2.10 (m, 1H), 1.80 (m, 2 H), and 1.68 (q, J=10.5 Hz, 1H). FIMS: m/z 248.3 (M+H) + ; m/z 245.4 (M−H) − . [α] 25 −12.32 (589 nm, c 1.93 mg/mL, EtOH). >97% purity (reverse-phase HPLC); >98% purity with >98% ee (Chiralpak AD, 10% ethanol, 90% hexane (0.1% diethylamine), 0.5 mL/min, R t =14.7 min)
Example 37
(1S,3R)-3-(3-Dimethylamino-cyclopentyl)-1-ethyl-1H-indole-5-carbonitrile
Compound 56
(1S,3S)-3-(3-Dimethylamino-cyclopentyl)-1-ethyl-1H-indole-5-carbonitrile
Compound 57
(1R,3S)-3-(3-Dimethylamino-cyclopentyl)-1-ethyl-1H-indole-5-carbonitrile
Compound 58
(1R,3R)-3-(3-Dimethylamino-cyclopentyl)-1-ethyl-1H-indole-5-carbonitrile
Compound 59
A solution of (1S,3R)-3-dimethylaminocyclopentyl)-1H-indole-5-carbonitrile (350 mg, 1.4 mMol) and potassium t-butoxide (233 mg, 2.1 mMol) in anhydrous THF (20 mL) was stirred under nitrogen for 30 m. Diethylsulfate (320 mg, 2.1 mMol) was added and the solution was stirred for 1.5 h. The reaction was poured into H 2 O (250 mL) and extracted with ethyl acetate. The organic extracts were washed with brine, dried over sodium sulfate, and concentrated in vacuo. The residue was purified by chromatography on silica gel (10 g) with 3% 2M NH 3 /methanol in CH 2 Cl 2 . The pure product fractions were concentrated and dried in vacuo to give (1S,3R)-3-(3-dimethylamino-cyclopentyl)-1-ethyl-1H-indole-5-carbonitrile (Compound 56) (208 mg, 53%). 1 H NMR (500 MHz, d4-MeOH) δ 8.02 (1 H s), 7.51 (1 H, d, J=8.55), 7.40 (1 H, dd, J=8.55 1.53), 7.28 (1 H, s), 4.21 (2 H, q, J=7.33), 3.36 (1 H, m), 2.76 (1 H, m), 2.40 (1 H, m), 2.32 (6 H, s), 2.21 (1 H, m), 2.06 (1 H, m), 1.83 (1 H, m), 1.75 (1 H, m), 1.65 (1 H, dd, J=21.97, 11.59), 1.41 (3 H, t, J=7.33). LCMS (XTERRA C18 S5 4.6×50 mm) t R , 1.253 min., MH + 282.29.
The following compounds were prepared using procedures similar to the above:
Compound 57: (1S, 3S)-3-(3-Dimethylamino-cyclopentyl)-1-ethyl-1H-indole-5-carbonitrile was prepared on a 0.071 mMol scale to yield 4 mg (20%). 1 H NMR (500 MHz, d4-MeOH) δ 7.99 (1 H s), 7.51 (1 H, d, J=8.55), 7.41 (1 H, dd, J=8.55 1.53), 7.24 (1 H, s), 4.21 (2 H, q, J=7.33), 3.48 (1 H, m), 2.83 (1 H, m), 2.31 (6 H, s), 2.25 (1 H, m), 2.11 (2 H, m), 1.98 (1 H, m), 1.79 (1 H, m), 1.66 (1 H, m), 1.41 (3 H, t, J=7.33). LCMS (XTERRA C18 S5 4.6×50 mm) t R , 1.253 min., MH + 282.29.
Compound 58: (1R,3S)-3-(3-Dimethylamino-cyclopentyl)-1-ethyl-1H-indole-5-carbonitrile was prepared on a 0.17 mMol scale to yield 26 mg (54%). 1 H NMR (500 MHz, d4-MeOH) δ 8.02 (1 H s), 7.50 (1 H, d, J=8.55), 7.40 (1 H, dd, J=8.55 1.53), 7.27 (1 H, s), 4.21 (2 H, q, J=7.33), 3.36 (1 H, m), 2.74 (1 H, m), 2.39 (1 H, m), 2.31 (6 H, s), 2.21 (1 H, m), 2.05 (1 H, m), 1.83 (1 H, m), 1.75 (1 H, m), 1.64 (1 H, dd, J=22.28, 11.59), 1.41 (3 H, t, J=7.33). LCMS (XTERRA C18 S5 4.6×50 mm) t R , 1.257 min., MH + 282.29.
Compound 59: (1R,3R)-3-(3-Dimethylamino-cyclopentyl)-1-ethyl-1H-indole-5-carbonitrile was prepared on a 0.065 mMol scale to yield 7 mg (38%). 1 H NMR (500 MHz, d4-MeOH) δ 7.99 (1 H s), 7.51 (1 H, d, J=8.55), 7.41 (1 H, dd, J=8.55 1.53), 7.24 (1 H, s), 4.21 (2 H, q, J=7.33), 3.48 (1 H, m), 2.82 (1 H, m), 2.30 (6 H, s), 2.25 (1 H, m), 2.12 (2 H, m), 1.98 (1 H, m), 1.78 (1 H, m), 1.65 (1 H, m), 1.41 (3 H, t, J=7.33). LCMS (XTERRA C18 S5 4.6×50 mm) t R , 1.257 min., MH + 282.29.
Example 38
Alternate procedure for the preparation of racemic Cis-3-(3-dimethylaminocyclopentyl)-1H-indole-5-carbonitrile
Sodium cyanoborohydride (2.8 g, 45 mMol) was added to a solution of racemic 3-(3-oxocyclopentyl)-1H-indole-5-carbonitrile (5 g, 22.3 mMol) and N-methylbenzylamine (7.25 mL, 56 mMol) in methanol (200 mL). The resulting mixture was stirred for 16 hr and then concentrated in vacuo. The residue was dissolved in ethyl acetate and washed with aqueous sodium bicarbonate, then with brine, and dried over magnesium sulfate. The ethyl acetate solution was concentrated in vacuo to give the crude product which was dissolved in methylene chloride (150 mL). Di-tert-butyl-dicarbonate (21 g, 96 mMol), triethylamine (13 mL, 94 mMol), 4-dimethylaminopyridine (200 mg, 1.64 mMol) were added to the solution. The resulting mixture was stirred for 2 h. The reaction mixture was washed with aqueous sodium bicarbonate. The aqueous layer was extracted with methylene chloride (2×50 mL). The methylene chloride extracts were combined, washed with aqueous sodium bicarbonate, and with brine, dried over magnesium sulfate. The methylene chloride solution was concentrated in vacuo to give the crude product as a mixture of cis/trans diastereomers. The mixture was separated by chromatography on silica gel using ethyl acetate/hexane (0–30%) to give cis-1-BOC-3-[3-(N-benzyl-N-methylamino)-cyclopentyl]-1H-indole-5-carbonitrile (5 g, 63%) and trans-1-BOC-3-[3-(N-benzyl-N-methylamino)-cyclopentyl]-1H-indole-5-carbonitrile (1 g, 13%) as evidenced by NOE NMR experiment. 1 H NMR (500 MHz, CDCl 3 ) cis: δ 1.67 (s, 9H); 1.83 (m, 3H); 2.06 (m,1H); 2.18 (s, 3H); 2.20 (m, 1H); 2.40 (m,1H); 3.00 (m, 1H); 3.25 (m,1H); 3.56 (dd, 2H); 7.33 (m, 5H); 7.48 (s, 1H); 7.53 (d, 1H); 7.89 (s, 1H); 8.23 (d, 2H). M+1=430. trans: δ 1.66 (s, 9H); 1.76 (m, 2H); 1.97 (m,1H); 2.10 (m, 1H); 2.18 (s, 3H); 2.23 (m, 2H); 3.08 (m, 1H); 3.39 (m,1H); 3.55 (s, 2H); 7.32 (m, 5H); 7.43 (s, 1H); 7.55 (d, 1H); 7.87 (s, 1H); 8.20 (d, 2H). M+1=430.
A mixture of cis-1-BOC-3-[3-(N-benzyl-N-methylamino)-cyclopentyl]-1H-indole-5-carbonitrile (500 mg, 1.2 mMol), 10% palladium on carbon (200 mg), formaldehyde (1.2 mL of 30% aqueous, 12 mMol), and acetic acid (0.1 mL) in methylene chloride (10 mL) and methanol (20 mL) was stirred under hydrogen (balloon pressure) for 4 h. The mixture was filtered and the filtrate was concentrated in vacuo. The residue was dissolved in methylene chloride (10 mL) and trifluoroacetic acid (3 mL) and stirred for 18 h. The solution was concentrated in vacuo, and the residue was dissolved in ethyl acetate. The ethyl acetate solution was washed with aqueous NaHCO 3 , and then brine, and dried over magnesium sulfate. The solution was concentrated to give the crude product which was purified by preparative HPLC to give cis-3-(3-dimethylaminocyclopentyl)-1H-indole-5-carbonitrile (120 mg, 40%).
Example 39
(1S)-3-(3-Amino-cyclopentyl)-1H-indole-5-carbonitrile
and
(3S,3′S)-Bis-(3-(5-cyano-1H-indol-3-yl)cyclopentyl)amine
A mixture of the (1S)-3-(3-oxocyclopentyl)-1H-indole-5-carbonitrile (1.0 g, 4.5 mMol), ammonium acetate (5.5 g, 71 mMol), sodium cyanoborohydride (0.3 g, 4.76 mMol), and 4A molecular sieves (3 g) in 20 mL of methanol was stirred at room temperature overnight. Reaction was filtered and the filtrate was concentrated. The residue was partitioned between ethyl acetate/aqueous sodium bicarbonate. The organic layer was washed by aqueous sodium bicarbonate and brine, dried with MgSO 4 , and concentrated to give the crude product (0.9 g) which was separated by preparative HPLC (Column: XTERRA 30×75 mm S5; Solvent A=10% methanol/90% H 2 O/0.1% TFA, Solvent B=90% methanol/10% H 2 O/0.1% TFA; Start 15% B, Final 100% B, Gradient time 8 min, Flow rate 30 mL/min).
Compound 60: (1S)-3-(3-Amino-cyclopentyl)-1H-indole-5-carbonitrile was the first to elute (149 mg, 15%) 1 H NMR (400 MHz, d4-MeOH) δ 8.0 (1H, m), 7.42 (1 H, m), 7.32 (1 H, m), 7.17 (1 H, d), 3.55 (1 H, m), 1.53–2.18 (m, 6H). LCMS (XTERRA C18 S7 3.0×50 mm) t R , 1.07 min., MH + 226.17.
Compound 61: (3S,3′S)-Bis-(3-(5-cyano-1H-indol-3-yl)cyclopentyl)amine eluted second (310 mg, 32%). 1 H NMR (400 MHz, d4-MeOH) δ 8.0 (1 H, d), 7.43 (2 H, d), 7.35 (2 h, d), 7.20 (2 H, d), 3.51 (2 H, m), 1.6–2.6 (12 H, m). LCMS (XTERRA C18 S7 3.0×50 mm) t R , 1.90 min., MH + 434.19.
Example 40
Serotonin Transporter Binding Assay
HEK-293 cells that stably express human serotonin transporters (HEK-hSERT cells) were grown at 37° C. in 5% CO 2 as a monolayer in medium consisting of EMEM supplemented with 10% fetal bovine serum and G418 sulfate (500 μg/mL). To prepare membranes for radioligand binding experiments, cells were rinsed twice with phosphate-buffered saline (138 mM NaCl, 4.1 mM KCl, 5.1 mM Na 2 PO 4 , 1.5 mM KH 2 O 4 , 11.1 mM glucose, pH 7.4). Cells were transferred from plates to polypropylene tubes (16×100 mm), centrifuged at 1,200×g for 5 min and were frozen at −80° C. until assay. Following centrifugation, pellets were resuspended by homogenization in buffer consisting of 50 mM Tris (pH 7.7 at 25° C.), 120 mM NaCl and 5 mM KCl and then centrifuged at 32,000×g for 10 min. Following centrifugation, supernatants were discarded and pellets were resuspended in buffer consisting of 50 mM Tris (pH 7.4 at 25° C.), 150 mM NaCl and 5 mM KCl. Membrane homogenates (200 μl/plate) were incubated with 1 nM [ 3 H]-citalopram (specific activity=85 Ci/mMol) and increasing concentrations of test compounds for 1 hr at 25° C. in a total volume of 250 μl. The assay buffer consisted of 50 mM Tris (pH 7.4 at 25° C.), 120 mM NaCl and 5 mM KCl (pH 7.4 with conc. HCl). Plates were incubated for 1 hr at 25° C., then filtered through 0.5% PEI treated Whatman GF/B filters using a Brandel cell harvester. Filters were washed three times with 3 mL of ice-cold tris wash buffer. Non-specific binding was defined with 10 μM fluoxetine. Amount of radioligand bound in the presence and absence of competitor was analyzed by plotting (−)log drug concentration versus the amount of radioligand specifically bound. The midpoint of the displacement curve (IC 50 , nM), signifies the potency. K i values were calculated using the method of Cheng and Prusoff (1973).
Example 41
Norepinephrine Transporter Binding Assay
MDCK cells that stably express human norepinephrine transporters (HEK-hNET cells) were supplied by Receptor Biology, Inc. Pellets were resuspended by homogenization in buffer consisting of 50 mM Tris (pH 7.4 at 25° C.), 120 mM NaCl and 5 mM KCl. Membrane homogenates (200 μl/well, 8 ug protein) were incubated with 2.7 nM [ 3 H]-nisoxetine (specific activity=80 Ci/mMol) and increasing concentrations of test compounds for 1 hr at 4° C. in a total volume of 250 μl. The assay buffer consisted of 50 mM Tris (pH 7.4 at 25° C.), 120 mM NaCl and 5 mM KCl (pH 7.4 with conc. HCl). Plates were incubated for 1 hr at 4° C., then filtered through 0.5% PEI treated Whatman GF/B filters using a Brandel cell harvester. Filters were washed three times with 3 mL of ice-cold tris wash buffer. Non-specific binding was defined with 10 μM desipramine. Amount of radioligand bound in the presence and absence of competitor was analyzed by plotting (−)log drug concentration versus the amount of radioligand specifically bound. The midpoint of the displacement curve (IC 50 , nM), signifies the potency. K i values were calculated using the method of Cheng and Prusoff (1973).
Compounds of the present invention demonstrate SERT binding and may be useful for the treatment of depression, anxiety disorders, premature ejaculation, chronic pain, obsessive-compulsive disorder, feeding disorders, premenstrual dysphoric disorder and panic disorders. Moreover, particular compounds of Formula I demonstrate no norepinephrine reuptake inhibition, and therefore should have a reduced probability of any cardiovascular liabilities associated with norepinephrine reuptake inhibition.
In the table below, binding results are denoted as follows:
COMPOUND
NAME
STRUCTURE
SERT
NE Reuptake
1
3-(3-Methylamino-cyclopentyl)-1H-indole-5-carbonitrile
B
E
2
3-(3-Ethylamino-cyclopentyl)-1H-indole-5-carbonitrile
B
E
3
3-(3-Dimethylamino-cyclopentyl)-1H-indole-5-carbonitrile
A
E
4
3-[3-(Ethyl-methyl-amino)-cyclopentyl]-1H-indole-5-carbonitrile
B
E
5
3-(3-Diethylamino-cyclopentyl)-1H-indole-5-carbonitrile
B
E
6
3-(3-Pyrrolidin-1-yl-cyclopentyl)-1H-indole-5-carbonitrile
B
E
7
3-[3-(1,3-Dihydro-isoindol-2-yl)-cyclopentyl]-1H-indole-5-carbonitrile
B
E
8
3-[3-(3,4-Dihydro-1H-isoquinolin-2-yl)-cyclopentyl]-1H-indole-5-carbonitrile
B
D
9
3-(3-Phenethylamino-cyclopentyl)-1H-indole-5-carbonitrile
B
D
10
3-[3-(Methyl-phenethyl-amino)-cyclopentyl]-1H-indole-5-carbonitrile
B
D
11
3-(3-Morpholin-4-yl-cyclopentyl)-1H-indole-5-carbonitrile
A
E
12
3-[3-(Benzyl-methyl-amino)-cyclopentyl]-1H-indole-5-carbonitrile
B
D
13
3-(3-Benzylamino-cyclopentyl)-1H-indole-5-carbonitrile
B
D
14
3-(3-Piperidin-1-yl-cyclopentyl)-1H-indole-5-carbonitrile
A
E
15
3-(3-Dipropylamino-cyclopentyl)-1H-indole-5-carbonitrile
B
E
16
3-(3-Propylamino-cyclopentyl)-1H-indole-5-carbonitrile
A
E
17
1-Methyl-3-(3-methylamino-cyclopentyl)-1H-indole-5-carbonitrile
B
E
18
3-(3-Ethylamino-cyclopentyl)-1-methyl-1H-indole-5-carbonitrile
A
E
19
3-(3-Benzylamino-cyclopentyl)-1-methyl-1H-indole-5-carbonitrile
B
D
20
1-Methyl-3-(3-phenethylamino-cyclopentyl)-1H-indole-5-carbonitrile
B
D
21
3-(3-Dimethylamino-cyclopentyl)-1-methyl-1H-indole-5-carbonitrile
B
E
22
3-[3-(Ethyl-methyl-amino)-cyclopentyl]-1-methyl-1H-indole-5-carbonitrile
B
E
23
3-(3-Diethylamino-cyclopentyl)-1-methyl-1H-indole-5-carbonitrile
A
E
24
1-Methyl-3-(3-pyrrolidin-1-yl-cyclopentyl)-1H-indole-5-carbonitrile
B
E
25
1-Methyl-3-(3-piperidin-1-yl-cyclopentyl)-1H-indole-5-carbonitrile
A
E
26
1-Methyl-3-(3-morpholin-4-yl-cyclopentyl)-1H-indole-5-carbonitrile
A
E
27
3-[3-(Benzyl-methyl-amino)-cyclopentyl]-1-methyl-1H-indole-5-carbonitrile
A
E
28
1-Methyl-3-[3-(methyl-phenethyl-amino)-cyclopentyl]-1H-indole-5-carbonitrile
B
D
29
1-Methyl-3-(3-propylamino-cyclopentyl)-1H-indole-5-carbonitrile
A
E
30
3-(3-Dipropylamino-cyclopentyl)-1-methyl-1H-indole-5-carbonitrile
A
E
31
3-[3-(Benzyl-methyl-amino)-cyclopentyl]-1-ethyl-1H-indole-5-carbonitrile
B
E
32
3-(3-Dimethylamino-cyclopentyl)-1-ethyl-1H-indole-5-carbonitrile
A
E
33
3-(5-Fluoro-1H-indol-3-yl)-cyclopentyl]-dimethyl-amine
A
E
34
Ethyl-[3-(5-fluoro-1H-indol-3-yl)cyclopentyl]-methyl-amine
B
E
35
Diethyl-[3-(5-fluoro-1H-indol-3-yl)-cyclopentyl]-amine
5
E
36
5-Fluoro-3-(3-pyridin-1-yl-cyclopentyl)-1H-indole
B
E
37
3-(4-Fluoro-1H-indol-3-yl)-cyclopentyl-dimethyl-amine
C
Not tested
38
3-(4-Bromo-1H-indol-3-yl)-cyclopentyl-dimethyl-amine
B
Not tested
39
3-(5-Chloro-1H-indol-3-yl)-cyclopentyl-dimethyl-amine
B
Not tested
40
3-(5-Bromo-1H-indol-3-yl)-cyclopentyl-dimethyl-amine
B
Not tested
41
3-(5-Iodo-1H-indol-3-yl)-cyclopentyl-dimethyl-amine
C
Not tested
42
3-(6-Fluoro-1H-indol-3-yl)-cyclopentyl-dimethyl-amine
B
Not tested
43
3-(6-Chloro-1H-indol-3-yl)-cyclopentyl-dimethyl-amine
B
Not tested
44
3-(6-Bromo-1H-indol-3-yl)-cyclopentyl-dimethyl-amine
B
Not tested
45
3-(7-Fluoro-1H-indol-3-yl)-cyclopentyl-dimethyl-amine
B
Not tested
46
3-(7-Chloro-1H-indol-3-yl)-cyclopentyl-dimethyl-amine
A
Not tested
47
3-(7-Bromo-1H-indol-3-yl)-cyclopentyl-dimethyl-amine
B
Not tested
48
(1S,3R)-3-(3-dimethylaminocyclopentyl)-1H-indole-5-carbonitrile
A
E
49
(1S,3S)-3-(3-dimethylaminocyclopentyl)-1H-indole-5-carbonitrile
A
E
50
(1R,3S)-3-(3-dimethylaminocyclopentyl)-1H-indole-5-carbonitrile
A
E
51
(1R,3R)-3-(3-dimethylaminocyclopentyl)-1H-indole-5-carbonitrile
A
E
52
(1S,3S)-3-(5-fluoro-1H-indol-3-yl)-cyclopentyl-dimethylamine
B
E
53
(1R,3S)-3-(5-fluoro-1H-indol-3-yl)-cyclopentyl-dimethylamine
A
E
54
(1R,3R)-3-(5-fluoro-1H-indol-3-yl)-cyclopentyl-dimethylamine
B
E
55
(1S,3R)-3-(5-fluoro-1H-indol-3-yl)-cyclopentyl-dimethylamine
B
E
56
(1S,3R)-3-(3-Dimethylamino-cyclopentyl)-1-ethyl-1H-indole-5-carbonitrile
A
E
57
(1S,3S)-3-(3-Dimethylamino-cyclopentyl)-1-ethyl-1H-indole-5-carbonitrile
B
E
58
(1R,3S)-3-(3-Dimethylamino-cyclopentyl)-1-ethyl-1H-indole-5-carbonitrile
A
E
59
(1R,3R)-3-(3-Dimethylamino-cyclopentyl)-1-ethyl-1H-indole-5-carbonitrile
B
E
60
(1S)-3-(3-Amino-cyclopentyl)-1H-indole-05-carbonitrile
C
Not tested
61
(3S,3′S)-bis-(3-(5-cyano-1H-indol-3-yl)cyclopentyl)amine
B
Not tested
A: Ki < 1 nM;
B: 1 nM < Ki < 10 nM;
C: 10 nM < Ki < 100 nM;
D: 100 nM < Ki < 1000 nM
E: Ki > 1000 nM | The present invention relates to compounds of Formula (I) and pharmaceutically acceptable salts or solvates thereof and pharmaceutically acceptable formulations comprising said compounds
useful for the treatment of premature ejaculation, depression, attention deficit hyperactivity disorder, obsessive-compulsive disorder, post-traumatic stress disorder and substance abuse disorders. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 60/402,546, filed Aug. 12, 2002.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an anti-mine unit or assembly of very robust construction that will explode anti-personnel mines and will dig up, expose, exhume and/or explode anti-tank mines. The detonation of the mines is done under a complex cover of cables and plates in order to absorb and deflect shrapnel and blast.
[0004] 2. Description of Related Art
[0005] Land mines are one of the weapons in the arsenal of modern warfare. There are land mines designed for different purposes, e.g., anti-personnel, anti-tank, etc. In time of war, it is frequently necessary to clear a minefield for the construction of an airfield, or to at least clear a path through the minefield for an advance. Minefields are often not completely cleared during wartime, and quite frequently civilians are injured by an exploding land mine years after the combat is over. Clearing minefields is hazardous duty. Several devices have been developed in an effort to clear minefields efficiently while reducing casualties which may otherwise occur while clearing minefields.
[0006] For example, U.S. Pat. No. 655,584, issued Aug. 7, 1900 to Schwartz, describes a combined roller and harrow consisting of a frame rotatably supporting a sectional or two-part roller and having a cross-strip detachably secured thereto at the rear.
[0007] U.S. Pat. No. 731,146, issued Jun. 16, 1903 to Wilmeth, describes a combined agricultural machine for multiple services in the tilling of soil. The invention provides for the operation of soil-working bits or members in a circular or rotative manner.
[0008] U.S. Pat. No. 1,102,326, issued Jul. 7, 1914 to Dalsing, describes a plow having means for swinging the cultivator blades laterally in and out between rows of plants so that the ground may be cultivated between the rows.
[0009] U.S. Pat. No. 1,679,628, issued Aug. 7, 1928 to Roby, describes an attachment mechanism between a plow and drill that insures proper travel of the drill, as well as permitting sharp turning thereof when necessary.
[0010] U.S. Pat. No. 2,920,405, issued Jan. 12, 1960 to Cole, describes a combination grading tool comprising a rake carrying frame member adapted to be hitched to a tractor for suspension from the rear thereof and a scarifier unit.
[0011] U.S. Pat. No. 2,964,863, issued Dec. 20, 1960 to Shepherd, describes a machine with movable trunnions. Various implements, such as a bulldozer blade, a ripper, a scraper blade, a push-loading scraper, a backfilling blade, or the like, may be provided.
[0012] U.S. Pat. No. 3,260,003, issued Jul. 12, 1966 to Rolfe, describes a bulldozer or like implement for attachment to a tractor.
[0013] U.S. Pat. No. 4,593,766, issued Jun. 10, 1986 to Gossard, describes a crawler tractor with a dozer blade and fitted with accessories to loosen the ground in the strafing pit area of a gunnery range and simultaneously remove from the ground rocks the size of a man's fist and larger and spent projectiles. The tractor is provided with an electromagnet positioned ahead of the dozer blade. Positioned to the rear of the tractor is a chisel bar with a plurality of chisel blades. Just ahead of the chisel bar is a rock rake that is supported with its tines at such an angle that their tips barely scrape the surface of the earth. Ahead of the rock rake, there is a drag consisting of a section of railroad rail suspended from the drawbars of the chisel assembly at a height sufficient to just scrape the surface of the ground during operation of the tractor.
[0014] U.S. Pat. No. 4,667,564, issued May 26, 1987 to Schreckenberg, describes an apparatus for clearing land mines that is provided with clearing elements which can freely move up and down independently of one another, and which are disposed in a movable carrier which is embodied as an attachment for a tracked or wheeled vehicle. Each clearing element is a small, rigid clearing plate having a supporting arm, which is suspended on a support associated with the movable frame, and is movable about a horizontal pivot axis which extends transverse to the direction of travel. The supporting arms of all of the clearing plates are the same length. All of the clearing plates, without contacting one another and at a slight distance from one another, are disposed in a compound arrangement which is parallel to the support and is arranged behind the latter in the direction of travel. The compound arrangement is either V-shaped, having its point facing in the direction of travel, or extends continuously at an angle to the direction of travel.
[0015] U.S. Pat. No. 5,183,119, issued Feb. 2, 1993 to Wattenburg, describes an anti-snag plowing system suitable for clearing mines. The plowing system comprises several digging-knife units, or plows, and a harrow. Both are attached in tandem to a chain matrix, which is pulled with either a helicopter or tractor. The digging-knife units rotate if the digging-knives hit an immovable snag. The harrow is covered with a chain blanket, and may have magnetic or sonic wave mine triggers if the system is used for clearing mines.
[0016] U.S. Pat. No. 6,330,920, issued Dec. 18, 2001 to Wanner, describes a mine stripper with numerous plow blades that rotate as they dig deeper to achieve an equilibrium depth of about nine inches and a basket that presses against the top of these blades to receive dislodged mines while sifting away attached soil.
[0017] WO93/11402, published Jun. 10, 1993 to Aardvark Clear Mine Limited, describes an apparatus for clearing mines. The apparatus includes a support on which is mounted a first impact device, such as a flail rotor. Also mounted on the support are a number of ground engaging members, each of which are adapted to extend below the surface of the ground being cleared so that when the support is moved across the surface, the members expose mines in their path. After being exposed, the first impact device generates an impact on the exposed mines.
[0018] None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant inventions as claimed.
SUMMARY OF THE INVENTION
[0019] The invention is an anti-mine unit or assembly for use with a tractor, bulldozer, or other implement that will explode anti-personnel mines and will dig up, expose and/or explode anti-tank mines. Heavy tubes having thick sidewalls, e.g., ¾ 41 thick, are welded together to form a frame from which heavy cables are supported. The heavy cables may be cut from 2″ and 3″ cables normally used in drag lines and other very heavy equipment. Digging cables, drag cables, curtain cables and deflector cables are attached to the frame with a thick top plate, e.g., ¾ 41 thick steel plate, to dig up, expose and/or explode anti-tank mines, explode anti-personnel mines, keep the explosions and shrapnel controlled, and clear a pathway for the vehicle's drive wheels or tracks.
[0020] The cables are arranged so that as the vehicle moves forward, a row of cables having digging blades penetrates the ground, then a row of drag cables having ground engaging blades rides over the ground detonating mines by contact and by weight. A pair of deflector cables is suspended from the frame in front of each track or front wheel to move any unearthed and undetonated mines out of the path of the vehicle's tracks or wheels. Curtain cables are suspended from the sides and rear of the frame and, together with the top plate, serve to diminish the force of detonations to protect the vehicle, the operator of the vehicle, and nearby personnel.
[0021] Accordingly, it is a principal object of the invention to provide an anti-mine unit for safe reduction of mines in minefields.
[0022] It is another object of the invention to provide an anti-mine unit that protects personnel assigned to dig up and/or explode mines in a minefield.
[0023] It is a further object of the invention to provide an anti-mine unit that not only explodes anti-personnel mines but dig ups anti-tank mines.
[0024] Still another object of the invention is to provide an anti-mine unit that will be able to withstand the shock of exploding mines, and still be useful to continue the minefield reduction without the need for placing individuals at risk to sweep the mines.
[0025] It is an object of the invention to provide improved elements and arrangements thereof in an anti-mine unit for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
[0026] 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
[0027] [0027]FIG. 1 is an environmental side view of an anti-mine unit according to the present invention mounted on a bulldozer.
[0028] [0028]FIG. 2 is a perspective view of the frame of the anti-mine unit with the top plate, rear curtain and side curtains removed.
[0029] [0029]FIG. 3 is a fragmented perspective view, partly in section, of the front portion of the frame of the anti-tank unit showing attachment of the digging and drag cables.
[0030] [0030]FIG. 4 is a side view of a deflector cable of the anti-tank unit of the present invention.
[0031] [0031]FIG. 5 is a fragmented rear view showing two adjacent deflector cables of the anti-tank unit of the present invention.
[0032] [0032]FIG. 6 is a fragmented side view of the left side curtain of the anti-tank unit of the present invention, partially assembled.
[0033] [0033]FIG. 7 is a fragmented perspective view of the top portion of a curtain cable of the anti-tank unit of the present invention.
[0034] [0034]FIG. 8 is a side view, partly in section, showing the relation of a curtain cable to the frame of the anti-mine unit of the present invention when under stress from an explosion.
[0035] [0035]FIG. 9 is a front perspective view part of a wire cutter blade holder bracket of the anti-mine unit of the present invention.
[0036] [0036]FIG. 10 is a side view of one of the wire cutters attached to the front beam of the anti-mine unit of the present invention.
[0037] [0037]FIG. 11 is a fragmented perspective view, partly in section, of the front beam of the anti-mine unit of the present invention showing staggering of the digging and drag cable brackets.
[0038] [0038]FIG. 12 is a perspective view of the top plate of the anti-mine unit of the present invention.
[0039] Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0040] The present invention is an anti-mine assembly or unit 100 adapted for being mounted to a heavy equipment vehicle or other prime mover for digging up, exposing and/or safely exploding mines, such as anti-personnel mines and heavy mines like anti-tank mines. The anti-mine unit 100 includes a frame, a plurality of digging cables, a plurality of drag cables, at least one side curtain, a rear curtain, and a top plate. The anti-mine unit 100 also has a pair of deflector cables mounted in front of the vehicle's tracks or front wheels, and may optionally one or more wire cutters mounted on the front of the frame.
[0041] In FIG. 1, the frame 1 of the anti-tank unit 100 is shown mounted to a bulldozer C upon the hydraulically operated hoist H 1 in place of the bulldozer blade. Normally, bulldozers have caterpillar tracks, as shown. The anti-mine unit 100 may also be mounted or placed upon other heavy equipment, such as tractors, front end loaders, tanks, scout cars, armored personnel carriers, tank retrievers, and others. For example, the anti-mine unit 100 may be mounted on a tracked front end loader, or a hydraulic excavator, with a quick hitch plate and a hydraulic swivel, the front end loader having the bucket removed and the operator cab well protected. The frame 1 preferably extends substantially or entirely across an end of the prime mover, and may be welded of 5″ round stock material of abnormally thick sidewalls, e.g., ¾ 41 thick steel, to have sufficient strength to withstand explosions from exploding mines. It is also considered feasible that square or rectangular stock material may be used, but round or cylindrical stock material, such as a pipe, is more easily accessible.
[0042] As shown in FIG. 2, the frame 1 has a front, beam 2 , an upper rear beam 8 , a lower rear beam 9 , upper right and left side beams 4 , 5 extending from the front beam 2 to the upper rear beam 8 , lower right and left side beams 14 , 15 extending diagonally from the front beam 2 to the lower rear beam 9 , right and left vertical rear beams 6 , 7 extending from the ends of the upper rear beam 8 to the corresponding ends of the lower rear beam 9 , and mounting beams 17 , 18 extending from the upper rear beam 8 to the lower rear beam 9 parallel to and between vertical rear beams 6 and 7 .
[0043] Front beam 2 , upper rear beam 8 , and upper side beams 4 and 5 define a substantially rectangular support on which the top plate 40 is mounted. Upper side beam 5 , lower side beam 15 , and vertical rear beam 7 defines a substantial triangular shape, as does upper side beam 4 , lower side beam 14 , and vertical rear beam 6 , in order to rigidly support front beam 2 in an elevated position at the front end of the anti-mine unit 100 .
[0044] The front beam 2 is preferably of large diameter, such as ten inches, in order to provide more and better area for the many welds that will be placed upon it, such as attachment of the front wire cutters 31 . Each of the mounting rear beams 17 , 18 , generally not less than ¾ 41 thick, has mounts 19 , 20 , respectively, for mounting the frame 1 to the prime mover. The frame 1 also has a plurality of lifting eyes 16 positioned on the front beam 2 and upper rear beam 8 to permit a lifting machine or vehicle to lift the frame 1 onto or off of the prime mover.
[0045] [0045]FIG. 11 shows a portion of the front beam 2 in greater detail. The front beam 2 has a plurality of digging cable shackles 21 and drag cable shackles 22 attached thereto by welding. Each shackle 21 ,. 22 is defined by an opposing pair of links or lugs having aligned apertures defined therein for receiving a shackle bolt or pin. It will be noted that the drag cable shackles 22 have two pairs of apertures defined therein, the upper pair for receiving a drag cable, the lower pair for receiving a digging cable. The digging cable shackles 21 may have a half-moon support 410 welded below the aperture for supporting the shackle pin, and the drag cable shackles 22 may have a similar half-moon support 420 welded below the aperture for the same purpose. The digging cable shackles 21 and drag cable shackles 22 are mounted in alternating fashion and are staggered or offset radially in order to facilitate insertion and removal of the shackle pins for quick removal and replacement of the cables, while permitting close placement of adjacent cables.
[0046] As best shown in FIGS. 2 and 3, the top of the frame 1 is supported by the diagonal braces 10 , 11 extending from the center of front beam 2 to the rear corners of the upper frame. The diagonal braces 10 , 11 are supported by the drag cable support beam 12 and the digging cable support beam 13 , which extend between upper side beams 4 and 5 . Drag lift cables 122 are attached to drag cable support beam 12 , while digging lift cables 132 are attached to digging cable support beam 13 . The drag lift cables 122 and digging lift cables 132 will prevent the drag cables 220 and digging cables 110 , respectively, from flaring out in front of the front beam 2 and possibly missing a ground mine if a mine is detonated under the assembly and top plate 40 .
[0047] To help dig through soil and rock, the digging cables 110 are sufficiently flexible to accommodate corrections to the right or left made by the prime mover. The digging cables 110 move upward and downward to follow the contour of the ground. Referring to FIG. 3, the digging cables 110 are detachably secured to the front beam 2 by the digging cable shackles 21 and the lower apertures (not numbered) of the drag cable shackles 22 . One of each pair of the digging cables 110 is attached to a corresponding digging cable shackle 21 , while the other of each pair is attached to the lower aperture of an adjacent corresponding drag cable shackle 22 . There are thirty-one pairs of digging cables 110 secured by 1¼ 41 pins 120 through the apertures in the shackles 21 , 22 for a ten foot long front beam 2 . The digging cables 110 are offset to permit the removal of the pins 120 for replacing digging cables 110 that are damaged by mine explosions, as described above.
[0048] Each digging cable 110 , being of 3″ diameter, is welded to digging cable head 124 by digging cable head cap 126 . The welding is effected by use of stainless steel, such as “308-16” rods. The ground end of each digging cable 110 has an end cap 112 welded to the cable 110 , and welded to the end cap 112 is a digger blade 114 and an upper blade 116 . As needed or desired, extra weight (not shown) may be added to each digging cable 110 to permit the digging cables 110 to perform effectively in hard, rough or muddy terrains. An example would be adding a block or weighted sleeve, such as a ½″, ¾ 41 or 1″ steel sleeve, or a bar, such as a 2″ by 4″ steel bar, to each end cap 112 .
[0049] The digger blade 114 needs to be of sufficient length and thickness, such as eight inches long by ¾ 41 thick, to effectively penetrate into and dig below the ground or ground level in order to make contact with and exhume, expose and/or explode mines that lie below the ground or ground level. When desired, such as when there are no known anti-tank mines in a minefield, and explosion of anti-personnel mines is all that is required, the digging cables 110 can be turned over to allow the upper blade 116 to engage the ground directly.
[0050] The upper blade 116 is cut back at the angle α of about 40° with respect to an axis normal to end cap 112 in order to reduce stresses when going through brush or high grass, and to allow the digging cables 110 to reach the ground and any hidden detonators. At the end of each digging cable 110 , there is a lift cable eye 118 , to which a corresponding digging lift cable 132 is attached. The digging lift cables 132 are intended to keep the digging cables 110 under the front beam 2 despite any tilting or stress placed upon the anti-mine unit 100 .
[0051] Similar to the digging cables 110 , the drag cables 220 are sufficiently flexible to accommodate corrections to the right or left made by the prime mover, and move upward and downward to follow the contour of the ground. The drag cables 220 generally do not push soil or rock, and can work in mud or underwater.
[0052] The drag cables 220 are used in pairs, and each of the fifteen pairs is detachably secured to the front beam 2 by a pin 120 through the upper aperture (not numbered) of a corresponding drag cable shackle 22 . A blade or lug 240 fits between the pair of apertures in each drag cable shackle 22 , and is welded to two arms 242 , which are in turn welded to two caps 246 , which are in turn welded to the cables of the pair of drag cables 220 . The drag cables 220 may be a little thinner, e.g., two inches in diameter, than the digging cables 110 , but welds are still by stainless 308 - 16 stock material or welding rods.
[0053] Three steel sleeves 224 , 226 , 228 , of ½ 41 thickness, are positioned upon each drag cable 220 , and each sleeve 224 , 226 , 228 has ground engaging blades 230 , 232 , 234 , which are intended to contact the ground and any detonators at or slightly below ground level. On the other side of the ground blades 230 , 232 , 234 , a grass blade 236 is welded upon each sleeve 224 , 226 , 228 to permit the drag cables 220 to be turned over for penetration of high grass, brush or hay, and is recessed at an angle α of about 40° in order to better penetrate.
[0054] A drag lift cable 122 is attached to an aperture in one of the grass blades 236 of a drag cable 220 in order to ensure that the drag cables 220 maintain appropriate orientation. As needed or desired, extra weight (not shown) may be added to each drag cable 220 to permit the drag cables 220 to perform effectively in hard, rough or muddy terrains. An example would be adding a block or weighted sleeve, such as a ½41 , ¾ 41 or 1″ steel sleeve, or a bar, such as a 2″ by 4″ steel bar, to one of the sleeves 224 , 226 , 228 of each drag cable 220 .
[0055] As shown in FIGS. 1 - 2 and 6 - 8 , both of the sides and the rear of the anti-mine unit 100 have a curtain (not numbered) of 2″ curtain cables 330 in close proximity to one another. These curtain cables 330 provide protection to the prime mover and personnel in the vicinity from shrapnel and flying dirt and rocks caused by mine explosions beneath the top plate 40 by keeping the dangers in a confined area. The right and left side curtains are mounted upon the upper side beams 4 , 5 , respectively, using the side curtain hangers 33 , and the rear side curtain is mounted upon the upper rear beam 8 using the rear curtain hangers 35 .
[0056] Extended pin 332 mounts the curtain cables 330 , which are each welded to an elbow 336 . Elbow 336 is of ¾ 41 steel sheet cut to size and shape. Washers 338 are welded to elbows 336 to space the cables 330 and allow free rotation of the elbows 336 . Five curtain cables 330 are placed every ten inches. As the curtain cables 330 will be placed under strain during explosions, they will be expected to fly outward. As shown in FIG. 8, a heavy tube 34 , which may be a solid rod, may be welded to the upper side beams 4 , 5 , and will keep the curtain cables 330 at or below 70° from vertical and facilitate shrapnel being forced into the ground and the recovery of the curtain cables 330 . The curtain cables 330 will generally flex when they come in contact with the ground or rocks.
[0057] Just in front of the track or tires of the prime mover are the deflector cables 370 L, 371 L (as best shown in FIGS. 4 and 5), which are 3″ cables that are intended to sweep exhumed and unexploded anti-tank mines from the path of the track/wheels of the prime mover. The deflector cables 370 L, 371 L are sufficiently flexible to accommodate corrections to the right or left made by the prime mover.
[0058] The upper rear beam 8 has deflector cable shackles 37 welded thereto. The deflector cables 370 L, 371 L are welded to caps 384 , which are in turn welded to arms 382 , which are in turn welded to blade or lug 380 , the blade 380 being affixed to the shackle 37 by a pin (not numbered) similar to the pin 120 mentioned above. The deflector cables 370 L, 371 L are relatively hefty and stiff but have end caps 374 welded thereto. Plows 376 , 378 are welded to the end caps 374 . Unlike ground plows, plows 376 , 378 are not intended to turn earth, but are generally trapezoidal with a horizontal, linear bottom edge for scraping the earth to move any exhumed land mines, especially anti-tank mines, away from the tracks or wheels of the prime mover.
[0059] A pair of deflector cables 370 L, 371 L are mounted on each side of the rear of frame 1 to provide the greatest possible protection for the prime mover. It is preferred that each pair of deflector cables 370 L, 371 L are bolted together at the bottom to prevent the pair from spreading apart.
[0060] [0060]FIGS. 9 and 10 are directed to wire cutters 31 which may optionally be mounted to front beam 2 . Wire cutters are seen to be important, as most mine barriers are surrounded by wire to keep people out (false minefields, wire with signs only, will often be very successful in keeping enemy assaults from being sent through very accessible terrain). Inexpensive and versatile, a wire cutter 31 is comprised of a blade holder having right and left sides 310 , 312 and a blade 314 . Wire cutter mounts 302 , 304 , 306 are mounted upon the front beam 2 . Cutter braces 316 , 318 are welded to the rear of the blade holders and removably attached to the mounts 302 , 304 , 306 by a long bolt 308 , while the blade 314 of the wire cutter 31 is removably attached to the blade holder by a plurality of bolts 320 .
[0061] As shown in FIGS. 1 and 12, the top plate 40 is rigidly secured, such as by welding, upon the top of the frame 1 such that the top plate 40 is prevented from flying off of the assembly after a mine explosion. The top plate 40 substantially or entirely covers the top of the frame 1 , and may be of a size, such as 5′ by 10′, that fits within the area defined by the lifting eyes 16 , as shown in FIG. 2. The top plate 40 has a plurality of holes 42 , preferably about two inches in diameter, to permit damaged digging and drag cables 110 , 220 to be detached and replaced without difficulty, and to allow chains or cables to be passed therethrough for lifting the drag cables 220 . Steel washers (not shown), about ½ 41 thick, may be welded to the underside or on top of the holes 42 to prevent the holes 42 from being damaged or split after a mine explosion. The top plate 40 may be ¾ 41 thick and will be effective in reducing shrapnel and “bouncing betty” type mines from injuring nearby personnel.
[0062] This anti-mine unit 100 , mounted upon a tracked or wheeled prime mover, is able to quickly and easily reduce a minefield of anti-personnel mines. Anti-tank mines can be exhumed and gathered, easily and safely. Any anti-tank mines that are booby-trapped to explode upon removal can be exploded under a very hefty and stout assembly that will yield with the blast and still retain integrity, even if some of the individual cables are damaged. Though it is advisable to provide a prime mover with armored cab, to protect the operator, very little shrapnel or blast debris should cause damage to personnel to the rear or sides, even though they should be removed by at least fifty yards or meters.
[0063] Though the anti-mine unit 100 is designed to not miss any mines by the overlap of the various cables, the minefield should be swept by other personnel. It goes without saying that with the anti-mine unit 100 detonating the vast majority of mines in the field, if not all, risk to sweeping personnel is greatly reduced.
[0064] 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. | An anti-mine unit or assembly is adapted for being mounted to a prime mover or transport vehicle to reduce the dangers when clearing minefields. The anti-mine unit includes a frame, a plurality of digging cables, a plurality of drag cables, at least one side curtain of curtain cables, a rear curtain of curtain cables, and a top plate. The anti-mine unit may include a wire cutting device and a plurality of deflector cables. Heavy tubes of thick sidewalls are welded together to form the frame from which heavy cables are supported. The digging cables, drag cables, curtain cables and deflector cables are secured to the frame such that the cables, frame, and thick top plate form a unit that digs up, exposes and/or explodes mines, keeps the explosions and shrapnel controlled, and clears a pathway for the vehicle's drive wheels or tracks. | 5 |
This invention relates to a laryngeal mask airway and a method for its use in intubation with an endotracheal tube. As used hereafter, "ETT" indicates an endotracheal tube, and "LMA" indicates a laryngeal mask airway.
The ETT is the most typical and effective device for ventilating the lungs of a patient, particularly an unconscious patient under general anesthesia. The ETT comprises a flexible tube which has an inflatable cuff near its distal end. The ETT is inserted into the trachea, a procedure called "intubation", and the cuff inflated below the vocal cords to seal the trachea and provide protection against the passage of regurgitated stomach contents into the trachea. It is important that the cuff is below the vocal cords to provide a proper seal and avoid damage to the vocal cords. In some patients, conventional intubation is very difficult or impossible.
The LMA is a more recently developed alternative ventilation device. The LMA comprises an airway tube and an inflatable mask at the distal end of the airway tube. The mask can be easily inserted into the pharynx of the patient and then inflated to seal against the laryngeal inlet. The LMA has the disadvantage of not adequately preventing the passage of regurgitated stomach contents into the trachea. The LMA also does not guarantee the ability to provide positive pressure ventilation.
A recently developed technique involves using the LMA as a guide for insertion of the ETT. In 1993, the American Society of Anesthesiologists added this technique to its Difficult Airway Algorithm. According to this technique, the LMA is placed in its normal position adjacent to the laryngeal inlet, and the ETT is then inserted into the airway tube of the LMA, through the mask, and into the trachea. In some patients, especially men, the standard 6.0 ETT, having an inside diameter of 6.0 mm and a length of 28.5 cm, will not extend into the trachea a sufficient distance to position the ETT cuff below the vocal cords. This problem, as well as a number of proposed solutions, is discussed in an article entitled "Intubation through the Laryngeal Mask Airway" by John H. Pennant et al, Anesthesiology, V. 84, No. 4, October 1995. Such solutions include: use of a 5.0 mm microlaryngeal tube, which is longer than the standard 6.0 ETT; use of a shortened version of the LMA (the ST-LMA); and cutting off about 2 cm of the LMA airway tube. Yet another proposed solution is discussed in an article entitled "Modified Intravent LMA" by J. Brimacombe et al., Anaesthesia and Intensive Care, Vol. 19, No. 4, November 1991. Brimacombe's solution involves drastic modifications of an LMA which include a slit from the proximal end of the LMA to its distal aperture, and removal of the mask aperture cross-bars.
Each of the proposed solutions suffer from at least one of the following problems, wherein the above-mentioned proposed solutions having such problems are indicated in parentheses: (1) does not employ standard 6.0 ETT (5.0 microlaryngeal tube); (2) does not maintain the structural integrity of the LMA mask (solution of Brimacombe); and (3) does not allow removal of the LMA from the patient while leaving the ETT in place, because an insufficient length of the ETT is exposed (cutting off 2 cm of LMA tube and shortened LMA). The ETT must be held in position while removing the LMA. Otherwise, the ETT will tend to be removed from its desired position when the LMA is removed. A sufficient length of the ETT must be exposed in order to grasp the ETT while simultaneously removing the LMA.
With respect to problem (1), the standard 6.0 ETT as compared to the 5.0 microlaryngeal tube has a lower resistance to gas flow and typically is more efficacious in providing adequate ventilation and oxygenation. Problem (2) does not allow reuse of the LMA, and does not allow ventilation with the LMA. With respect to problem (3), leaving the LMA in place with the ETT can make certain types of surgeries, such as facial, oral, or throat surgery, difficult or impossible. It is also frequently desirable to stabilize the ETT with tape or some other means at the mouth of the patient, and/or to insert a nasal or oral gastric tube into the patient. Neither of these procedures can be carried out when the LMA is left in the patient. If long term intubation is necessary (i.e. subsequent to a surgical procedure), oral hygiene and clearing of secretions is difficult with the LMA in place. Prolonged placement can also lead to injury or edema in the oropharyngeal cavity.
SUMMARY OF THE INVENTION
It is, therefore, an object of the invention to provide an LMA which can be used to intubate a patient with an ETT so as to guarantee placement of the cuff below the vocal cords.
It is also an object of the invention that the LMA allows use of a standard 6.0 ETT, maintains the structural integrity of the mask, and allows easy removal of the LMA from the patient while leaving the ETT in the trachea.
The above objects are realized by an LMA of the type having an inflatable mask for sealing around the laryngeal inlet of a patient, and also having an airway tube connected to the mask and being adapted to deliver air therethrough to the mask and the laryngeal inlet, wherein the airway tube comprises: a first tube section having a first proximal end and a first distal end, the first distal end being connected to the mask; and a second tube section having a second proximal end and a second distal end, the second distal end being removably connected to the first proximal end, and wherein the second tube section has a pair of radially opposite separation lines longitudinally extending from the second proximal end to the second distal end to thereby allow the second tube section to be split apart along the separation lines.
According to another aspect of the invention, there is provided a method of intubating a patient with an ETT by using an LMA, wherein the ETT is of the type which comprises a tube having a proximal end, a distal end, and an inflatable cuff adjacent to the distal end, and wherein the LMA is of the type described above, the method comprising: (a) providing an airway tube for the LMA as described above; (b) inserting the LMA into the patient so that the mask is positioned immediately adjacent to the laryngeal inlet; (c) after step (b), inserting the ETT through the airway tube and through the mask so as to extend into the trachea of the patient; (d) after step (c), peeling away the second tube section by splitting it apart along the separation lines; and (e) during or after step (d), further inserting the ETT into the trachea to position its cuff below the vocal cords of the patient.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an LMA in accordance with the invention.
FIG. 2 is a view of the LMA of FIG. 1 as viewed along line 2--2 in FIG. 1.
FIG. 3 is an enlarged, cross-sectional view of a portion of the LMA shown in FIGS. 1 and 2.
FIGS. 4-9 show the LMA of FIGS. 1-3 in use to intubate a patient with an ETT.
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of the invention will now be described with reference to the FIGURES.
Referring to FIG. 1, the illustrated LMA 10 is of the type having an inflatable mask 12 and an airway tube 14 connected to mask 12 and being adapted to deliver air therethrough to mask 12. Mask 12 is shown as being in a deflated state, and is conventional in having an inflatable ring 16, a web 18, and a tubular inlet member 20 having one end integral with web 18 and the other end permanently connected to airway tube 14 in the manner described below. Mask 12 is preferably comprised of flexible silicone rubber. An inflation tube 22, also preferably silicone rubber, is connected at one end to ring 16 so as to communicate with its interior. At the other end of inflation tube 22 is a check valve 24 having a pilot bulb 26 associated therewith. Pilot bulb 26 has approximately the same capacity as ring 16, and serves as an inflation indicator.
Airway tube 14 comprises a tube section 28 and a tube section 30. Tube section 28 is preferably shorter in length than tube section 30, and is most preferably about one inch long where LMA 10 is a size 3 or 4 LMA. Tube section 28 has a proximal end 28a and a distal end 28b, and tube section 30 has a proximal end 30a and a distal end 30b. Distal end 28b is fixedly and permanently connected (i.e. by welding) to inlet member 20, and proximal end 28a is removably connected to distal end 30b in a manner described with reference to FIG. 3. Tube section 30 has a pair of radially opposite separation lines 32 longitudinally extending from proximal end 30a to distal end 30b. Only one separation line 32 is shown in FIG. 1. Separation lines 32 are preferably formed by scoring the wall of tube section 30. Since it is desired that LMA 10 be usable to ventilate the lungs of a patient, separation lines 32 are preferably impermeable to air. As will be further discussed with reference to FIG. 7, separation lines 32 allow tube section 30 to be split apart. To assist the user in splitting apart, or peeling away, tube section 30, a pair of radially opposite wings 34 are provided at proximal end 30a. Wings 34 radially and outwardly extend from proximal end 30a at respective positions circumferentially offset from separation lines 32.
The material employed for tube section 30 can be any nontoxic and sterilizable material that is peelable along separation lines 32. Such material should preferably have at least some flexiblity. Flexible polyvinyl chloride and silicone rubber are preferred with regard to flexibility, but semi-rigid materials such as polyethylene or tetrafluroethylene could also be used if tube section 30 Was suitably preshaped to approximate the necessary contour for placement in the patient. Wings 34 can be integral with and be the same material as tube section 30. Or, wings 34 can be comprised of a different material and be permanently connected to proximal end 30a. The material for tube section 28 can be the same as or different than the material employed for tube section 30. Silicone rubber is preferred.
Also shown in FIG. 1 is a connector 36 as removed from proximal end 30a. Connector 36, preferably comprised of a substantially rigid plastic, is adapted to be tightly and sealingly received in tube section 30 at proximal end 30a. A breathing circuit can be connected to LMA 10 by means of connector 36.
Referring now to FIG. 2, this partial view of LMA 10 shows the other separation line 32 as well as other details of mask 12. Mask 12 further has an interior or lumen 38, an aperture 40 into which inlet member 20 opens, and cross-bars 42 which extend across aperture 40.
Referring now to FIG. 3, this enlarged and partial cross-sectional view shows the manner in which proximal end 28a and distal end 30b are removably connected. Connector 44, comprised of any suitably rigid plastic, preferably has tapered ends and an intermediate portion of substantially uniform diameter along the length thereof. One portion of connector 44 is received in, and preferably permanently secured within, proximal end 28a, and the other portion of connector 44 is sized to be tightly and removably received within distal end 30b. FIG. 3 shows distal end 30b as being disconnected from proximal end 28a. Connector 44 preferably has an inside diameter large enough to receive a 6.0 ETT therethrough.
The use of LMA 10 in intubating a patient with an ETT will now be described with reference to FIGS. 4-9. It should be understood that the anesthesiologist's and/or technician's hands are not shown for clarity of illustration. The hand(s) of at least one person manipulate(s) LMA 10 and the ETT as shown in FIGS. 4-9.
Referring now to FIG. 4, there is shown a patient 46 having an oral cavity 48, a throat 50, an esophagus 52, a trachea 54, a laryngeal inlet 56, and vocal cords 58. Mask 12 of LMA 10 is positioned immediately adjacent to laryngeal inlet 56 and is inflated with a syringe 60 or other suitable means to establish a seal around laryngeal inlet 56. Connector 36 is received within proximal end 30a to allow connection to a breathing circuit (not shown). It is desirable at this point to briefly ventilate the lungs of patient 46 with LMA 10 in order to oxygenate the patient and confirm the correct placement of the LMA.
Referring now to FIG. 5, there is shown a fiberoptic tube 62 of a bronchoscope after having been preloaded with an ETT 64 (preferably a 6.0 ETT) and inserted through LMA 10 so as to extend into trachea 54. The distal end of fiberoptic tube 62 is positioned below vocal cords 58 as shown. Use of the bronchoscope and its fiberoptic tube 62 is desirable since the anesthesiologist can view the position of the fiberoptic tube's distal end, thereby easing the task of locating laryngeal inlet 56. ETT 64, having a deflated cuff 66 and inflation tube 68, is preloaded onto fiberoptic tube 62 since a handpiece (not shown) connected to the proximal end of fiberoptic tube 62 would not permit sliding of ETT 64 over the fiberoptic tube once it is inserted into patient 46.
Referring now to FIG. 6, ETT 64 is shown after having been moved downward over fiberoptic tube 62 and into trachea 54. As shown, in this particular patient 46, cuff 66 is not positioned below vocal cords 58 as desired. Fiberoptic tube 62 can now be removed while holding the proximal end of ETT 64 to prevent unintended withdrawal of the ETT.
Referring now to FIG. 7, after removing fiberoptic tube 62 and also deflating ring 16, a first person grasps opposing wings 34 with each hand, and a second person holds ETT 64. The first person then pulls on each wing 34 to start peeling away tube section 30, thereby causing connector 36 (FIG. 6) to simply fall away if not previously removed. As tube section 30 is peeled away by the first person, mask 12 and tube section 28 are gradually withdrawn through throat 50 and oral cavity 48, while at the same time ETT 64 can be advanced further into trachea 54 by the second person. Once tube section 30 is completely peeled away, mask 12 and tube section 28 are moved upwardly by the first person to completely remove them from ETT 64, while the second person continues to hold ETT 64 to prevent its unintended withdrawal. Mask 12 and tube section 28 can be sterilized and reused with a new, peelable tube section.
Referring now to FIG. 8, ETT 64 is shown after the LMA is completely removed therefrom and from patient 46. ETT 64 is shown after having been advanced to its desired position with cuff 66 below vocal cords 58. FIG. 9 shows ETT 64 in this desired position after having cuff 66 inflated with syringe 70 or other suitable means. FIG. 9 also shows a conventional breathing circuit connector 72 received within the proximal end of ETT 64. A breathing circuit can accordingly be connected to ETT 64 by means of connector 72 to start normal ventilation.
Therefore, the LMA of the invention successfully achieves intubation with an ETT, and also allows use of a standard 6.0 ETT, maintains the structural integrity of the mask for ventilation and reuse, and allows its easy removal while leaving the ETT in place.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. For example, rather than use a connector to removably connect proximal end 28a to distal end 30b, such ends could be adapted to removably mate with one another without requiring a connector. With regard to the method of using the inventive LMA, the LMA could be used in a "blind" intubation without using the bronchoscope. It is, therefore, to be understood the within the scope of the appended claims, the invention can be practiced otherwise than as specifically described. | A laryngeal mask airway (LMA) is provided which can be easily and effectively used to intubate a patient with an endotracheal tube (ETT). The LMA of the invention is of the type having an inflatable mask and an airway tube connected to the mask. The airway tube comprises a first tube section having a distal end connected to the mask, and a second tube section having a distal end removably connected to the proximal end of the first tube section. The second tube section has longitudinally extending separation lines which allow it to be split apart. This feature enables complete removal of the LMA and successful incubation with the cuff of the ETT below the vocal cords of the patient. | 0 |
FIELD
[0001] The present disclosure relates generally to cargo loading systems and, more specifically, to cargo loading systems utilizing compact centrifugal air blowers.
BACKGROUND
[0002] Conventional aircraft cargo systems typically include various tracks and rollers that span the length of an aircraft. Cargo may be loaded from an aft position on an aircraft and conducted by the cargo system to a forward position and/or, depending upon aircraft configuration, cargo may be loaded from a forward position on an aircraft and conducted by the cargo system to an aft position. Conventional systems are typically designed to accommodate a particular pallet size. Conventional systems are typically comprised of numerous components that may be time consuming to install, replace and maintain.
SUMMARY
[0003] A cargo loading system in accordance with the present disclosure may comprise a cargo shuttle having a frame, an air cushion located beneath the cargo shuttle, a compact centrifugal air blower positioned within the frame of the cargo shuttle and comprising an outlet in fluid communication with the air cushion, a stator integrated into a first heat diffuser, and a magnet concentrically surrounding the stator. The compact centrifugal air blower may include impeller concentrically surrounding the stator and physically coupled to the magnet. The outlet and/or inlet may be perpendicular to the stator. The compact centrifugal air blower may pump air into the air cushion at a rate between about 6 kPa and about 70 kPa. The height of the compact centrifugal air blower may be between about 25 mm and about 50 mm. The impeller may be concentrically surrounded by a second heat diffuser.
[0004] A compact centrifugal air blower in accordance with the present disclosure may comprise an outlet in fluid communication with an air cushion, a stator integrated into a first heat diffuser, an impeller concentrically surrounding the stator, wherein a magnet is physically coupled to the impeller, and a second heat diffuser concentrically surrounding the impeller. The outlet may be perpendicular to the stator. The blower may include an inlet perpendicular to the stator. Further, the compact centrifugal air blower may pump air into the air cushion at a rate between about 6 kPa and about 70 kPa and a height of the compact centrifugal air blower is between about 25 mm and about 50 mm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The subject matter of the present disclosure is particularly pointed out and distinctly claimed in the concluding portion of the specification. A more complete understanding of the present disclosure, however, may best be obtained by referring to the detailed description and claims when considered in connection with the drawing figures, wherein like numerals denote like elements.
[0006] FIG. 1 illustrates a portion of a cargo management system, in accordance with the present disclosure;
[0007] FIG. 2 illustrates a portion of a cargo management system, in accordance with the present disclosure;
[0008] FIG. 3 illustrates a portion of a cargo management system, in accordance with the present disclosure;
[0009] FIG. 4 illustrates a portion of a cargo management system, in accordance with the present disclosure; and
[0010] FIGS. 5A and 5B illustrate, respectively, a perspective view and a cross-sectional view of a compact centrifugal blower, in accordance with the present disclosure.
DETAILED DESCRIPTION
[0011] The detailed description of embodiments herein makes reference to the accompanying drawings, which show embodiments by way of illustration. While these embodiments are described in sufficient detail to enable those skilled in the art to practice the inventions, it should be understood that other embodiments may be realized and that logical and mechanical changes may be made without departing from the spirit and scope of the inventions. Thus, the detailed description herein is presented for purposes of illustration only and not for limitation. For example, any reference to singular includes plural embodiments, and any reference to more than one component or step may include a singular embodiment or step. Also, any reference to attached, fixed, connected or the like may include permanent, removable, temporary, partial, full and/or any other possible attachment option.
[0012] As used herein, “aft” refers to the direction associated with the tail of an aircraft, or generally, to the direction of exhaust of the gas turbine. As used herein, “forward” refers to the direction associated with the nose of an aircraft, or generally, to the direction of flight or motion.
[0013] Aircraft cargo management systems as disclosed herein allow cargo to be loaded into an aircraft and positioned within the aircraft in a simple, elegant manner. In that regard, aircraft cargo management systems as disclosed herein may reduce part count and associated replacement/wear costs over time.
[0014] Cargo loading systems of the present disclosure comprise one or more compact centrifugal air blowers which provide air to air cushions to elevate one or more cargo shuttles. The compact nature of the air blowers allows for improved fitment within an aircraft cargo area.
[0015] With reference to FIGS. 1 and 2 , an aircraft cargo management system 100 in accordance with the present disclosure is illustrated using an x, y, and z axes for ease of illustration. Air cushion cargo shuttle 114 and 116 are shown forward of an aft portion of an aircraft. In various embodiments, air cushion cargo shuttle 114 may be coupled to an aft drive shuttle belt 106 and air cushion cargo shuttle 116 may be coupled to an aft drive shuttle belt 108 . Aft drive shuttle belt 106 is coupled to an aft drive shuttle unit 102 , and aft drive shuttle belt 108 is coupled to an aft drive shuttle unit 104 .
[0016] In various embodiments, a floor panel 112 is positioned beneath air cushion cargo shuttle 114 . Similarly, a floor panel 150 may be positioned beneath air cushion cargo shuttle 116 . As used with respect to air cushion cargo shuttle 114 and 116 , the term “beneath” may refer to the negative z direction. As used with respect to air cushion cargo shuttle 114 and 116 , the term “above” may refer to the positive z direction. In various embodiments, support rails 222 and 224 are laterally adjacent to floor panels 112 and 150 , and may be mounted to another aircraft component, such as an airframe, and may be capable of supporting the weight of cargo. Floor panel 112 may comprise at least one of a composite material or a metallic material.
[0017] Air cushion cargo shuttle 114 may, for example, be coupled to forward drive shuttle belt 208 and air cushion cargo shuttle 116 is coupled to forward drive shuttle belt 218 . Forward drive shuttle belt 208 is coupled to forward shuttle drive unit 204 . Forward drive shuttle belt 218 is coupled to forward shuttle drive unit 220 . Cargo 202 is shown as resting on support rails 222 and cargo 201 is shown as resting on support rails 224 . In various embodiments, cargo shuttle 116 may be used to lift cargo 201 off support rails 224 in the positive z direction and move cargo 201 forward or aft.
[0018] Forward drive shuttle belt 208 , forward drive shuttle belt 218 , aft drive shuttle belt 106 , and aft drive shuttle belt 108 (collectively, a “shuttle belt”) may comprise any suitable belt capable of pulling an air cushion cargo shuttle. For example, a shuttle belt may comprise a flat belt. In that regard, a flat shuttle belt may not occupy excess space along the z direction. For example, a shuttle belt may comprise a polyurethane coated belt that includes a communications and power bus. In that regard, the structural support and power/data functions are provided by a single shuttle belt structure. For example, in various embodiments, a shuttle belt may comprise steel wires oriented in parallel and coated with polyurethane to hold the steel wires together, provide anti-friction properties, and noise dampening properties. Among the steel wires may be copper wires or other wires that are capable of carrying an electrical current at any suitable voltage. In that regard, the shuttle belt may comprise one or more copper wires to carry high voltage power and/or low voltage electrical signals that may convey data.
[0019] The shuttle belts may be wound around a portion of forward shuttle drive unit 204 , forward shuttle drive unit 220 , aft drive shuttle unit 102 and aft drive shuttle unit 104 (collectively, “shuttle drive unit”). In that regard, a shuttle drive unit may comprise a cylindrical structure (e.g., a bobbin) to which a shuttle belt is affixed. The shuttle drive unit comprises a motive device, such as an electric motor, to rotate the bobbin in a desired direction.
[0020] With reference to FIGS. 3 and 4 , air cushion cargo shuttle 114 may further comprise an air cushion 330 positioned beneath air cushion cargo shuttle 114 . It should be understood that air cushion cargo shuttle 116 is similarly structured and thus the features discussed herein relative to air cushion cargo shuttle 114 are also applicable to air cushion cargo shuttle 116 . Air cushion 330 is in fluid communication with an outlet of a centrifugal air blower 304 . In that regard, centrifugal air blower 304 may blow air beneath air cushion cargo shuttle 114 and, more specifically, into volume 302 . Volume 302 is shown in proximity to floor panel 112 .
[0021] Centrifugal air blower 304 is shown located beneath air cushion cargo shuttle 114 . Air cushion cargo shuttle 114 may comprise one or more centrifugal air blowers. In various embodiments, centrifugal air blower 304 is a compact air blower designed to fit entirely and/or at least partially beneath air cushion cargo shuttle 114 and within air cushion 330 . For example, centrifugal air blower 304 may comprise a height 520 (with momentary reference to FIG. 5B ) that is equal to or less than the height (measured along the z axis) of air cushion 330 . For example, the height along the z axis of the air cushion 330 may be about 2 inches. In such embodiments, height 520 of air cushion cargo shuttle 114 may be less than about 2 inches. In various embodiments, height 520 of air blower 304 may be between 1 inch (25 mm) to 5 inches (125 mm), 1.5 inch (37 mm) and 3 inches (75 mm), and about 2 inches (50 mm), where the term about in this context may refer to +/−0.5 inch (12 mm).
[0022] In various embodiments, compact centrifugal air blower 304 comprises a permanent magnet motor. For example, with reference to FIG. 5 , blower 304 may comprise a direct-current brushless motor having a stator 522 surrounded by a magnet 524 . Stator 522 may be physically coupled to a heat diffuser, such as first heat diffuser 526 . In various embodiments, stator 522 is press fit into a cavity 528 of first heat diffuser 526 .
[0023] Blower 304 may further comprise an impeller 530 . In various embodiments, magnet 524 is physically coupled to impeller 530 , and magnet 524 and impeller 530 concentrically surround stator 522 . For example, magnet 524 may be a cup style magnet integrated into impeller 530 . Impeller 530 and magnet 524 may rotate around stator 522 , pumping air out compact centrifugal air blower 304 . Impeller 530 may comprise, for example, a heat conducting metallic material such as aluminum. In such embodiments, impeller 530 may act to cool magnet 524 during operation of blower 304 .
[0024] In various embodiments, blower 304 may comprise a second heat diffuser 532 which concentrically surrounds impeller 530 . Second heat diffuser 532 may act to cool stator 522 during operation of blower 304 . In various embodiments, second heat diffuser 532 acts to diffuse the high velocity air leaving impeller 530 , converting it to a lower velocity, higher pressure air. Second heat diffuser 532 may be coupled to stator 522 via, for example, press fitting into cavity 528 . The heat generated in stator 522 may be conducted through cavity 528 and into second heat diffuser 532 . In various embodiments, second heat diffuser 532 may be a vaned centrifugal compressor diffuser.
[0025] Blower 304 may further comprise an inlet 540 which provides air to blower 304 . In various embodiments, inlet 540 draws air from outside of air cushion 330 in to blower 304 . Inlet 540 may, for example, be oriented perpendicularly to stator 522 .
[0026] In various embodiments, blower 304 may comprise an outlet 542 . Outlet 542 is in fluid communication with and provide pressurized air to air cushion 330 . Similar to inlet 540 , outlet 542 may be oriented perpendicularly to stator 522 . In various embodiments, inlet 540 comprises a constant velocity configuration that reduces turbulence in the incoming air. Although described in connection with a single blower 304 , system 100 may comprise multiple blowers, and each blower may comprise one associated inlet, though in various embodiments one blower is associated with multiple inlets. In further embodiments, a single inlet may supply air to one or more compact centrifugal air blowers.
[0027] In various embodiments, impeller 530 forces air across second heat diffuser 532 and out of inlet 540 . Such configurations may provide improved cooling of stator 522 by providing air flow across and through second heat diffuser 532 .
[0028] Centrifugal air blower 304 is controlled by centrifugal air blower controller 302 . Air cushion cargo shuttle 114 may comprise one or more centrifugal air blower controllers. In various embodiments, each centrifugal air blower has one associated centrifugal air blower controller, though in various embodiments one centrifugal air blower controller controls multiple centrifugal air blowers. Centrifugal air blower controller 302 may provide power and instructions to centrifugal air blower 304 to control how and when centrifugal air blower 304 operates.
[0029] As shown, air cushion cargo shuttle 114 has four centrifugal air blower controllers 302 , 414 , 416 , and 418 driving four centrifugal air blowers 304 , 420 , 422 , and 424 to blow air into four different volumes 402 , 426 , 428 , and 430 . Each centrifugal air blower controller may further comprise a proximity sensor that may be configured to measure the proximity of a portion of air cushion cargo shuttle 114 to floor panel 112 . For example, proximity sensors 406 , 408 , 410 and 412 may be associated with each centrifugal air blower controller 302 , 414 , 416 , and 418 . Proximity sensors 406 , 408 , 410 and 412 may be used in a closed loop control mechanism to modulate the output of four centrifugal air blowers 304 , 420 , 422 , and 424 . In that regard, centrifugal air blower controllers 302 , 414 , 416 , and 418 may command four centrifugal air blowers 304 , 420 , 422 to blow air into volumes 402 , 426 , 428 , and 430 until the proximity sensors 606 , 608 , 610 and 612 indicate that a desired proximity has been reached.
[0030] Moreover, data from proximity sensors 406 , 408 , 410 and 412 may be used to detect and compensate for uneven cargo loads. For example, in the event cargo 202 shifts to one portion of air cushion cargo shuttle 114 or otherwise exerts more force on a portion of air cushion cargo shuttle 114 relative to another, data from proximity sensors 406 , 408 , 410 and 412 may detect that one portion of air cushion cargo shuttle 114 is not as far from floor panel 112 as one or more other portions of air cushion cargo shuttle 114 . In that regard, where insufficient distance from floor panel 112 is achieved, a centrifugal air blower controller may command its associated centrifugal air blower to increase output to compensate for the uneven load.
[0031] In that regard, in operation, cargo such as cargo 202 may be loaded onto air cushion cargo shuttle 114 at an aft position, such as a position proximate aft drive shuttle unit 102 . Cargo 202 may be positioned onto air cushion cargo shuttle 114 using power drive unit 308 and roller 306 . During loading of cargo 202 , air cushion cargo shuttle 114 may be in contact with floor panel 112 . Once cargo 202 is suitably positioned on top of air cushion cargo shuttle 114 (where the phrase “on top” in this context may refer to distance across the positive z direction), a control system for centrifugal air blower controller 302 may instruct centrifugal air blower 304 to begin operation. In this manner, air from inlets 540 is pulled into centrifugal air blower 304 and centrifugal air blower 304 blows this air into volume 402 . As more air is blown into volume 402 , the increased air pressure may act to lift air cushion cargo shuttle 114 apart from floor panel 112 . In this context, the phrase “lift apart” may refer to movement of air cushion cargo shuttle 114 in the positive z direction. In various embodiments, the pressure in volume 402 may reach between 1 psi (6.89 kPa) to 10 psi (68.9 kPa), between 2 psi (13.7 kPa) and 6 psi (41.3 kPa), and about 4 psi (27.5 kPa), where the term about in this context may refer to +/−0.5 psi (3.4 kPa).
[0032] A control system comprising, for example, a processor and a tangible, non-transitory memory may be configured to be in electrical and/or logical communication with centrifugal air blower controller 302 . For example, the control system may communicate with centrifugal air blower controller 302 via one or more shuttle belts. The control system may instruct the centrifugal air blower controller 302 to start, stop, and modulate the output of centrifugal air blower 304 .
[0033] During operation of centrifugal air blower 304 , cargo 202 may lift apart from floor panel 112 , thus reducing the friction between air cushion cargo shuttle 114 and the floor panel 112 . Stated another way, dry friction may be equal to the coefficient of friction multiplied by the normal force. By eliminating the contact between air cushion cargo shuttle 114 and the floor panel 112 , the two surfaces do not interact to cause friction. In various embodiments, there may be contact between air cushion cargo shuttle 114 and the floor panel 112 during operation of centrifugal air blower 304 , though the air pressure will oppose the normal force (i.e., force in the negative z direction) exerted by cargo 202 and thus friction will be reduced because of this reduction in the normal force.
[0034] While cargo 202 is lifted apart from floor panel 112 , the forward shuttle drive unit 204 may rotate its bobbin, causing forward drive shuttle belt 208 to pull air cushion cargo shuttle 114 and cargo 202 forward. Aft drive shuttle unit 104 may be allowed to exert a low level drag force on shuttle drive belt 108 , thus allowing aft drive shuttle belt 108 to extend in a forward direction. A low level drag force exerted by aft drive shuttle unit 104 may prevent excessive cargo velocity and may maintain stability in the event an aircraft is not precisely level. Once cargo 202 is positioned in the aircraft at a desired position, the control system may instruct the centrifugal air blower controller 302 to turn off or lower the output of centrifugal air blower 304 . In that regard, due to loss of air pressure in volume 402 , air cushion cargo shuttle 114 may move in a negative z direction and contact floor panel 112 . As air cushion cargo shuttle 114 moves towards floor panel 112 , cargo 202 may come to rest on support rails 222 . Thus, the air cushion cargo shuttle 114 may separate from the cargo 202 as the cargo 202 is restrained from motion in the negative z direction by support rails 222 . In this manner, air cushion cargo shuttle 114 may be brought aft to load additional cargo. The aft drive shuttle unit 102 may rotate its bobbin, causing aft drive shuttle belt 108 to pull air cushion cargo shuttle 114 aft. Additional cargo may now be loaded and the process may proceed again.
[0035] Benefits, other advantages, and solutions to problems have been described herein with regard to specific embodiments. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in a practical system. However, the benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of the disclosure. The scope of the disclosure is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” Moreover, where a phrase similar to “at least one of A, B, or C” is used in the claims, it is intended that the phrase be interpreted to mean that A alone may be present in an embodiment, B alone may be present in an embodiment, C alone may be present in an embodiment, or that any combination of the elements A, B and C may be present in a single embodiment; for example, A and B, A and C, B and C, or A and B and C. Different cross-hatching is used throughout the figures to denote different parts but not necessarily to denote the same or different materials.
[0036] Systems, methods and apparatus are provided herein. In the detailed description herein, references to “one embodiment,” “an embodiment,” “an example embodiment,” etc., 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 is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. After reading the description, it will be apparent to one skilled in the relevant art(s) how to implement the disclosure in alternative embodiments.
[0037] Furthermore, no element, component, or 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 claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112(f), unless the element is expressly recited using the phrase “means for.” As used herein, the terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. | The present disclosure includes cargo loading systems and components including cargo systems utilizing one or more air cushions to elevate one or more cargo shuttles. Air is delivered to the air cushions by compact centrifugal air blowers. Such compact centrifugal air blowers are designed to provide sufficient power to inflate air cushions, while having a sufficiently short profile. | 5 |
RELATED APPLICATIONS
[0001] This application is related to U.S. Provisional Patent Application Ser. No. 60/993,512, filed Sep. 11, 2007 entitled RETROFIT SYSTEM FOR DOORS, WINDOWS AND FRAMED OPENINGS.
TECHNICAL FIELD
[0002] This invention relates to molding systems for installation in homes, offices, and other buildings and, more particularly, to retrofit decorative molding systems which are quickly and easily mounted in position directly over existing molding elements without requiring the use of adhesives, nails, other similar fastening elements.
BACKGROUND ART
[0003] Individuals are continuously upgrading their residences and/or offices in order to improve the visual appeal of their homes or businesses. Frequently, these upgrades include decorative or aesthetic improvements or enhancements which are employed for making homes/businesses more visually attractive both for the owner as well as for resale of the home/business. In addition, similar improvements or enhancements are also employed by home/business builders in order to impart greater interest and excitement to a newly built home/business to enable the home/business to be more attractive and saleable.
[0004] Although these improvements and enhancements may take many different forms, frequently, owners and builders add decorative features to a home/business which involve moldings, such as casement moldings, employed about doors, windows, entryways, and the like, as well as accent molding, ceiling molding or lineal segments mounted along the juncture between a wall and ceiling, along the perimeter of the room, such as chair rails, and the like. Use of molding of this general nature, and in and these particular areas, has become increasingly popular, and has generated substantial interest in the consumer market as well as in the homebuilder or office building market.
[0005] Although substantial interest has been generated focusing on the use and installation of various molding elements in existing homes/businesses as well as homes/businesses being professionally constructed, difficulties and drawbacks are frequently encountered in the installation of molding elements, which difficulties and drawbacks have not been resolved. In particular, it is well-known that molding elements or segments are typically constructed from wood, plastic or polymer materials, and require technical expertise for properly measuring and cutting the molding segments in the desired manner. Typically, one skilled in the finish carpentry trade is needed to obtain optimal results.
[0006] In general, the experienced tradesman or one having extraordinary technical skill is required for cutting the molding members to have the precisely desired length for having the adjacent segments abut each other in a manner which is visually acceptable. In particular, corners require mitered cuts of each segment to assure that the abutting segments are interconnected at a precisely 90° angle. Clearly, finish carpentry skills are required to cut precise lengths at accurate right angles in order to achieve desired results. In addition, in order to eliminate unsightly holes in finished surfaces caused by nails or screws, labor intensive filling of the holes is required.
[0007] One area which is of particular interest to consumers is in the area of remodeling, redesigning or improving existing structures. In this regard, existing molding which has been installed around door frames, window casements, and the like, are areas in which consumers frequently wish to upgrade or retrofit in order to produce a new, aesthetically pleasing, visual result. Although it is possible to remove existing molding around doors and windows, this process is extremely difficult and costly.
[0008] In particular, window and door assemblies generally comprise a number of frame elements which are assembled to form the window or door in the desired shape. In conventional remodeling, existing window or door frames must frequently be removed in order to install new window or door frames. In some instances, the removal of window or door frames may result in deformation being caused to components thereof, preventing the reuse of any existing structures. Furthermore, the complete removal of existing window and door frames with its associated molding requires substantial labor intensive effort due to the need to remove nails and/or repair any destruction caused by removing components secured in place by adhesives.
[0009] An additional problem found in prior art constructions is a requirement that molding components are mounted in place by use of adhesives or fastening materials such as nails. In particular, the use of nails causes unsightly holes to be formed in the molding members, which are incapable of being totally hidden, or require labor intensive efforts to obscure, and result in unsightly and unpleasant visual effects. In addition, the use of adhesives adds an additional level of difficulty to the installation process, often causing unwanted spattering and drops to be formed which are difficult to remove. Furthermore, the material employed for adhesives is often corrosive and/or toxic, thereby requiring special treatment and handling, as well as being environmentally unfriendly.
[0010] Although substantial effort has been expended in developing prior art products which have attempted to reduce or eliminate these problems, no prior art system has been capable of eradicating these problems. Consequently, molding installation occurring today continues to suffer from all of the drawbacks and difficulties detailed above.
[0011] Therefore, it is a principal object of the present invention to provide a retrofit decorative molding system which is easily employed to redecorate or retrofit existing molding installations with ease and simplicity.
[0012] Another object of the present invention is to provide a retrofit decorative molding system having the characteristic features described above which is quickly and easily installed by both professionals and homeowners and provides error free, aesthetically pleasing results.
[0013] Another object of the present invention is to provide a retrofit decorative molding system having the characteristic features described above which virtually eliminates any gaps, holes, or other visually unappealing defects commonly found in prior art constructions.
[0014] Another object of the present invention is to provide a retrofit decorative molding system having the characteristic features described above which is employed without requiring the removal of any exisiting molding components.
[0015] Another object of the present invention is to provide a retrofit decorative molding system having the characteristic features described above which is capable of being installed without requiring the formation of any mitered edges or abutting edges.
[0016] Another object of the present invention is to provide a retrofit decorative molding system having the characteristic features described above which is capable of being installed without requiring any adhesives, chemical-based fasteners, and/or environmentally unfriendly compositions.
[0017] Other and more specific objects will in part be obvious and will in part appear hereinafter.
SUMMARY OF THE INVENTION
[0018] By employing the present invention, all of the difficulties and drawbacks found in prior art installations for redesigning molding systems employed around windows, doors, and the like are overcome and a retrofit molding system is achieved which is capable of being quickly and easily installed in any desired location by unskilled individuals, without requiring the use of mitered corners, abutting junctures, nails, adhesives, and the like. In accordance with the present invention, this unique, and easily installed, retrofit molding system employs a plurality of supporting brackets which are quickly and easily mounted to existing molding strip surfaces and are constructed for receiving and supportingly retaining any desired new, visually distinctive, decorative substitute molding strips. In this regard, the new, substitute molding strips are formed in a wide variety of decorative and visually distinctive appearances in order to satisfy the desires of any individual for a visually distinctive and aesthetically pleasing appearance.
[0019] In addition, the retrofit molding system of the present invention incorporates corner forming assemblies which are quickly and easily mounted in the corners of every window, door, or other area in which the retrofit system is installed. By employing the corner forming assemblies of the present invention, the need for mitering the newly installed, retrofit molding systems is completely eliminated and the need for a high level of technical skill is avoided.
[0020] In addition, by eliminating the need for any mitered corners, the presence of any gaps or unsightly abutment joints in the newly installed system are completely avoided, as well as any unsightly nail or screw holes in visible surfaces. By employing the combination of the components forming the retrofit molding system of the present invention, any desired location can be quickly and easily redecorated with a completely installed retrofit molding system for enhancing the visual and aesthetic appeal of any window, door, or other similar area.
[0021] In accordance with the present invention, any desired visual configuration for redesigning the molding surrounding windows, doors, and the like is quickly and easily achieved in any desired location without requiring the existing molding to be removed or the door frame assembly or window casement assembly being reconstructed. Furthermore, by employing the retrofit molding system of the present invention, the use of adhesives, nails or other fastening elements which would be visible are also eliminated.
[0022] In the present invention, support brackets are employed which are quickly and easily mounted to the existing molding strips by employing threaded screw members. Once the brackets are mounted in position, the desired, newly selected, decorative molding strips are quickly and easily securely affixed to the support brackets. In addition, mitering of abutment joints are totally eliminated by employing corner mounted support brackets or clips and fully constructed corner block covers which are quickly and easily mounted to the supporting clips/brackets to complete the visual appearance of the corners.
[0023] By employing preformed corner assemblies, which comprise the clip/brackets and the corner covers, a visually distinctive, aesthetically pleasing, corner structure is realized without requiring any molding strips to be cut, abutted to each other, or mitered. As a result, ease of installation is realized, as well as a professionally completed, visually pleasing appearance which can be obtained by any individual even with unskilled installers.
[0024] In the present invention, each of the retrofit molding strips, as well as the corner block covers are constructed in a wide variety of decorative, visually distinctive configurations. As a result, individuals are able to select from numerous product choices in order to achieve a retrofit molding system installation which satisfies the personal desires of the consumer. In this way, any desired visual appearance for a particular door, window, or other area is capable of being satisfied, with a complete installation of the retrofit decorative molding system of the present invention being completed quickly and easily, without requiring the use of nails, adhesives, or any other undesirable fasteners. Furthermore, the final installation is devoid of any mitered joints, abutting edges, visible holes, as well as the gaps or separations which typically occur in these constructions.
[0025] Furthermore, by employing the present invention, an individual is able to change or alter the retrofit molding system in its entirety after its installation. Since the newly installed decorative molding strips and corner block covers are all mounted in position by being secured to support bracket members, an individual is able to change the visual appearance of any molding system installed about windows or doors with ease and simplicity by merely removing the decorative elements after installation and mounting a new system with a totally different aesthetic visual appearance as a substitute therefor. In this way, decorative touches in a particular room or throughout an entire home can be altered at will, without requiring extensive or inexpensive reconstruction costs.
[0026] The invention accordingly comprises an article of manufacture possessing the features, properties, and relation of elements which will be exemplified in the article hereinafter described, and the scope of the invention will be indicated in the claims.
THE DRAWINGS
[0027] For a fuller understanding of the nature and objects of the invention, reference should be had for the following detailed description, taken in connection with the accompanying drawings, in which:
[0028] FIG. 1 is an exploded perspective view of a fully installed retrofit molding system in accordance with the present invention mounted to any existing doorway;
[0029] FIG. 2 is a perspective view of a decorative panel which forms a component of the retrofit decorative molding system of FIG. 1 ;
[0030] FIG. 3 is an end in view of the decorative panel of FIG. 2 ;
[0031] FIG. 4 is a perspective view of a panel supporting clip forming a component of the retrofit molding system of FIG. 1 ;
[0032] FIG. 5 is a side elevation view of the panel supporting clip of FIG. 4 ;
[0033] FIG. 6 is a cross-sectional plan view of a typical installation of the decorative panel and panel supporting clip mounted to the molding of a conventional framed doorway;
[0034] FIG. 7 is a perspective view of an alternate panel supporting clip for use in the retrofit decorative molding system of the present invention;
[0035] FIG. 8 is a cross-sectional plan view of a typical installation employing the alternate panel supporting clip and decorative panel mounted to a reduced width molding framed doorway;
[0036] FIG. 9 is a perspective view, partially broken away, of the retrofit decorative molding system of the present invention fully installed in the corner of a typical doorway;
[0037] FIG. 10 is an exploded perspective view of the retrofit decorative molding system installation of FIG. 9 ;
[0038] FIG. 11 is a front perspective view of the corner forming clip/bracket which forms a component of the retrofit decorative molding system of FIG. 1 ;
[0039] FIG. 12 is a rear perspective view of the corner forming clip/bracket of FIG. 11 ;
[0040] FIG. 13 is a front perspective view of the corner forming block cover which forms a component of the retrofit decorative molding system of FIG. 1 ; and
[0041] FIG. 14 is a rear perspective view of the corner forming block cover of FIG. 13 .
DETAILED DESCRIPTION
[0042] By referring to FIGS. 1-14 , along with the following detailed discussion, the preferred construction and operation of the retrofit decorative molding system of the present invention can best be understood. Although this disclosure fully details the preferred embodiment of the present invention, alterations and variations in the embodiment provided herein can be made without departing from the scope of this invention. Consequently, it should be understood that the disclosure of the embodiment shown in FIGS. 1-14 and discussed in the following disclosure are provided for exemplary purposes only and should not be interpreted in a limiting sense.
[0043] In FIG. 1 , a typical installation of retrofit decorative molding system 20 of the present invention is provided, depicting the complete assembly of molding system 20 to a door frame. In FIGS. 1 , a door frame is depicted for exemplary purposes only, and it should be understood that virtually a identical retrofit decorative molding system 20 would be installed in a substantially identical manner about a window casement, or any other similar construction.
[0044] In the installation depicted in FIG. 1 , all of the components forming retrofit decorative molding system 20 are shown in association with pre-existing door frame assembly 24 . In this regard, all of the principal components forming door frame assembly 24 are shown with pre-existing molding 25 representing a principal component of door frame assembly 24 . Furthermore, as is evident from the foregoing detailed discussion, the particular visual appearance employed for retrofit molding system 20 and shown in FIGS. 1-14 represent one configuration of numerous alternate configurations, each of which provide a unique and distinctive visual appearance.
[0045] In the preferred construction of the present invention, retrofit decorative molding system 20 comprises elongated, longitudinally extending decorative panels 200 , panel supporting clips 100 , corner forming clip or bracket 300 , and corner forming block cover 400 . By employing these components and mounting these components in the manner shown in the Figures and detailed below, the construction, installation, and use of retrofit decorative molding system 20 of the present invention is achieved quickly and easily, without requiring trained personnel for its use and installation. Furthermore, as detailed below, adhesive, nails, and visible fastening means in the outside surface are eliminated, as well as the need for mitering any component.
[0046] In FIGS. 2 and 3 , the preferred construction for decorative panel 200 is shown. As depicted, decorative panel 200 comprises an elongated, longitudinally extending, substantially straight length of pre-formed material incorporating top surface 210 which incorporates particularly desired decorative appearance formed therein. As discussed above, top surface 210 is constructed with numerous alternate configurations, each of which provides a unique and distinctive visual appearance. In this way, any desired visually distinctive, aesthetically pleasing decorative design desired by a consumer can be provided, with the retrofit decorative molding system 20 effectively establishing the precise visual appearance sought by the consumer.
[0047] Typically, decorative panel 200 is constructed in uniform elongated lengths, which are then cut to a particular desired dimension. In this regard, the installer would merely measure the length required for covering molding 25 from the floor to the top of the doorway just below the pre-existing mitered corner and then cut the preformed length of panel 200 to the desired dimension. As a result, decorative panel 200 incorporates substantially flat terminating ends 203 and 204 .
[0048] In the preferred embodiment, decorative panels 200 are formed from closed cell polymer materials which are molded in order to enable a wide variety of alternate configurations, designs, and visual appearances to be achieved with reasonable manufacturing costs. In this regard, although virtually any closed cell polymer can be employed, it has been found that polyurethane represents the preferred material of choice.
[0049] In the preferred construction, decorative panel 200 incorporates bottom surface 211 , and side surfaces 212 and 213 . In addition, elongated, longitudinally extending slot 202 is formed in bottom surface 211 , spaced inwardly from side surface 212 . Furthermore, panel 200 incorporates flange 201 formed at the terminating end of side surface 213 with flange 201 and extending inwardly therefrom to form L-shaped abutment surface 215 . As detailed below, by employing this construction for decorative panel 200 , decorative panel 200 is quickly and easily securely affixed to panel supporting clips 100 , for achieving the complete installation of retrofit decorative molding system 20 both quickly and easily.
[0050] In FIGS. 4 and 5 , the preferred embodiment for panel supporting clips 100 is depicted. And shown therein, panel supporting clip 100 comprises a single, substantially rectangular shaped plate member 110 which incorporates a plurality of interconnected sloping sections, along with screw receiving holes 104 and 105 formed therein. In addition, plate member 100 is constructed with an overall sloping shape in order to accommodate the typical sloped configuration of conventional molding 25 affixed to door frame assemblies 24 . Although the precise configuration of molding 25 would typically vary in its visual appearance, the overall sloping shape employed is generally consistent, with the configuration of plate member 110 being constructed for accommodating virtually all molding configurations.
[0051] In addition, plate member 110 incorporates proximal terminating end 111 and distal terminating end 112 . Proximal terminating end 111 incorporates flange or wall 102 mounted thereto, substantially at right angles to terminating end 111 of plate member 110 and extending in a first direction relative to plate member 110 . Furthermore, flange 102 incorporates a plurality of outwardly extending barb members 106 formed at the terminating end thereof.
[0052] In completing the construction of plate member 110 of panel supporting clip 100 , distal end 112 incorporates wall 103 mounted thereto at substantially right angles therewith, with wall 103 extending from distal end 112 in a direction opposite from flange 102 of proximal end 111 . Furthermore, wall 103 incorporates a plurality of outwardly extending locking flanges 101 which, as further detailed below, cooperate with L-shaped abutment surface 215 of flange 201 to securely retain decorative panel 200 in the precisely desired position. In the preferred construction, the plurality of flanges 101 are affixed to wall 103 at substantially right angles thereto, with each flange 101 being positioned in juxtaposed, parallel, spaced, relationship with each other.
[0053] By referring to FIGS. 1 and 6 , along with the following detailed disclosure, the rapid, easy, and trouble-free installation of decorative panel 200 to door frame assembly 24 can best be understood. Furthermore, as is evident from this disclosure, decorative panel 200 is securely mounted to pre-existing door frame assembly 24 without requiring the use of any externally visible nails, screws, adhesives, or other fastening means.
[0054] As a result, once installed, decorative panels 200 are completely free of any unsightly holes formed by such fastening means as well as being completely free of any gaps, cracks, or crevices which might otherwise exist using prior art installations. Furthermore, the use of any undesirable adhesives is also completely avoided, thereby providing an installation which is environmentally friendly.
[0055] As depicted, a plurality of panel supporting clips 100 are mounted to existing molding 25 of door frame assembly 24 . Preferably, the plurality of panel supporting clips 100 are mounted in spaced intervals along the length of molding 25 , in order to provide secure, supporting, locking engagement of decorative panels 200 with door frame assembly 24 . In securely affixing supporting clips 100 to molding 25 , screws 700 are preferably employed which are merely inserted through screw receiving holes 104 and 105 of plate member 110 and threadedly engaged with door frame assembly 24 as well as wall and stud assembly 500 to which door frame assembly 24 is affixed. Once each of the plurality of panel supporting clips 100 are mounted in place, each pre-cut length of decorative panel 200 is ready to be securely affixed to clips 100 .
[0056] In order to securely mount decorative panel 200 to panel supporting clips 100 , the user is only required to position inwardly extending flange 201 below the plurality of locking flanges 101 of clip 100 , effectively bringing L-shaped abutment surface 215 into locking engagement with flanges 101 . Once in this position, side surface 213 of decorative panel 200 is securely mounted to supporting clip 100 .
[0057] Thereafter, the entire affixation process is quickly and easily completed by inserting flange 102 of clip 100 onto longitudinally extending slot 202 of panel 200 . This insertion process brings barbed members 106 of flange 102 into frictional, secure, locking engagement with the walls of slot 202 . When this quick, simple, and easily achieved mounting process is completed, decorative panel 200 is securely affixed to panel supporting clips 100 and pre-existing door frame assembly 24 .
[0058] In installing retrofit decorative molding system 20 of the present invention to door frame assembly 24 , each of the two additional decorative panels 200 are mounted to door frame assembly 24 using the identical process detailed above. Once all of the decorative panels 200 have been fully installed, retrofit decorative molding system 20 is almost complete. The only remaining elements to be mounted to door frame assembly 24 , in order to complete the entire installation, are the two corner forming clips/brackets 300 and corner forming covers 400 , the installation details of which are provided below.
[0059] As is evident from the foregoing detailed discussion, the installation of each decorative panel 200 is achieved quickly and easily, without requiring the use of any adhesives, nails, or screw members for fastening decorative panels 200 to door frame assembly 24 . As a result, unsightly nail or screw holes are completely avoided, as well as any requirement that adhesives be used. In this way, an environmentally friendly installation system is realized, as well as achieving a complete installation which is aesthetically pleasing and visually satisfying, while also being accomplished quickly and easily.
[0060] Furthermore, by employing retrofit decorative molding system 20 of the present invention, previously existing door frame assembly 24 remains completely intact, without any requirement that any portion of existing door frame assembly 24 needs to be disassembled. As a result, the installation of retrofit decorative molding system 20 of the present invention is accomplished quickly and expeditiously, while also being completed with substantially less labor and cost.
[0061] In some installations, door and/or window molding comprises a width which is substantially smaller than the width of more typical molding. In other to enable retrofit molding system 20 of the present invention to be quickly and easily affixed to all existing molding 25 , regardless of the width of the molding, an alternate panel supporting clip construction is employed. By referring to FIGS. 7 and 8 , along with the following detailed disclosure, the construction and installation of alternate panel supporting clip 800 can best be understood.
[0062] In this alternate construction, panel supporting clip 800 incorporates plate member 810 which comprises a plurality of interconnected sloping sections to accommodate the typical sloped configuration of molding 25 affixed to door frame assembly 24 . In addition, plate member 800 comprises proximal terminating end 811 and a distal end 812 which is interconnected with U-shaped portion 803 . Since the reduced width molding 25 is typically unable to support plate member 810 in its entirety, U-shaped extension portion 803 is formed as an integral component of support clip 800 , preferably being interconnected to distal end 812 .
[0063] Alternate panel supporting clip 800 also incorporates L-shaped extension 801 which is interconnected at one end to U-shaped portion 803 and terminates at its opposed end with outwardly extending flange 814 . Preferably, outwardly extending wall 815 is also formed on the outside surface of L-shaped extension 801 . In addition, terminating end 811 of plate member 810 of clip 800 incorporates upstanding flange 802 extending perpendicularly from plate member 810 , with a plurality of barbed members 806 extending outwardly therefrom. Finally, clip 800 incorporates screw receiving holes 804 and 805 formed therein which cooperate with screw members to secure alternate panel supporting clip 800 to pre-existing door frame assembly 24 .
[0064] Using the construction detailed above, a plurality of alternate panel supporting clips 800 are quickly and easily installed to existing molding 25 of door frame assembly 24 . In this regard, the plurality of panel supporting clips 800 are mounted to reduced width molding 25 in spaced intervals along the length of molding 25 , in order to provide secure, supporting, locking engagement of decorative panels 200 with door frame assembly 24 having reduced width molding 25 . In securely affixing supporting clips 800 to reduced width molding 25 , screws 700 are preferably employed and are merely inserted through screw receiving holes 804 and 805 of clip 800 .
[0065] In this regard, screw member 700 inserted through receiving hole 805 is threaded directly into reduced width molding 25 . However, screw member 700 inserted through receiving holes 804 extends beyond the width of the molding 25 and is incapable of being threadedly engaged with molding 25 . However, due to the placement of screw receiving hole 804 in U-shaped portion 803 as well as the construction of U-shaped portion 803 , the bottom surface of U-shaped portion 803 is in contact with wall/stud assembly 500 and enables screw member 700 to be threadedly engaged directly in wall/stud assembly 500 . In this way, alternate panel supporting clip 800 is quickly and easily mounted to door frame assembly 24 , while still enabling molding 25 to be retained on door frame assembly 24 without any removal thereof. Once each of the plurality of alternate panel supporting clips 800 are mounted in place, the pre-cut lengths of decorative panel 200 are ready to be securely affixed to clips 800 .
[0066] In order to securely mount decorative panels 200 to alternate panel supporting clips 800 , the user is only required to position inwardly extending flange 201 of panel 200 below outwardly extending flange 814 of L-shaped extension 801 of clip 800 , effectively bringing L-shaped abutment surface 215 into locking engagement with flange 814 and outwardly extending wall 815 . Once in this position, side surface 213 of decorative panel 2000 is securely mounted to supporting clip 800 .
[0067] Thereafter, the entire affixation process is quickly and easily completed by inserting upstanding flange 802 of clip 800 into longitudinally extending slot 202 of panel 200 . This insertion process brings barbed members 806 of flange 802 into frictional, secure, locking engagement within slot 202 . When this quick, simple, and easily achieved mounting process is completed, decorative panel 200 is securely affixed to alternate panel supporting clips 800 and pre-existing door frame assembly 24 .
[0068] Once all of the decorative panels 200 are mounted to alternate clips 800 , the installation of retrofit decorative molding system 20 is almost complete. As is evident from the foregoing detailed disclosure, the installation of decorative panels 200 are achieved quickly and easily, without requiring the use of any adhesives, nails, or screw members for fastening decorative panels 200 to door frame assembly 24 . As a result, unsightly nail or screw holes are completely eliminated along with any requirement that adhesives be employed. In this way, an environmentally friendly installation is realized, as well as the attainment of a complete installation which is aesthetically pleasing and is visually satisfying, while also being accomplished with speed and efficiency.
[0069] Furthermore, by employing retrofit decorative molding system 20 of the present invention, previously existing door frame assembly 24 with reduced width molding 25 remains completely intact, without any requirement that any portion of existing door frame assembly 24 needs to be disassembled. As a result, substantially less labor and costs are required in achieving a complete installation of retrofit molding system 20 of the present invention.
[0070] The entire installation of retrofit decorative molding system 20 of the present invention is completed by mounting corner forming clip/bracket 300 and corner forming block cover 400 to each corner of doorframe assembly 24 . By referring to FIGS. 9-14 , along with the following detailed discussion, the construction of each of these components, along with their rapid, trouble-free installation can best be understood.
[0071] As depicted, corner forming clip/bracket 300 comprises a preformed bracket assembly having a supporting base 314 and is constructed for being quickly and easily securely affixed to the corner forming portions of molding 25 . Preferably, corner forming clip/bracket 300 is formed from plastic material which has been molded to achieve a construction for being quickly and easily positioned in overlying relationship with corner forming molding 25 and is secured thereto by screws 700 . In this regard, corner forming clip/bracket 300 incorporates screw receiving holes 306 , 307 , 308 , and 309 formed on base 314 .
[0072] In order to enable corner forming clip/bracket 300 to be quickly and easily mounted in place on molding 25 , clip/bracket 300 incorporates side forming flanges 315 and 316 which extend from base 314 . In addition, flanges 315 and 316 are configured for contacting and peripherally surrounding the side edges of corner forming molding 25 while positioning base 314 in overlying relationship with corner forming molding 25 .
[0073] Furthermore, clip/bracket 300 incorporates end extensions 303 and 304 which extend from base of 314 and are constructed for overlying and covering the terminating ends of decorative panels 200 after being affixed to doorframe assembly 24 . In this way, the terminating ends of decorative panels 200 are not visible, and no visible gap or other opening exists between decorative panels 200 and corner forming block cover 400 and/or corner forming clip/bracket 300 .
[0074] In order to enable corner forming block cover 400 to be quickly and easily securely mounted to corner forming clip/bracket 300 , corner forming clip/bracket 300 incorporates upstanding oval shaped wall member 305 mounted to the top surface of base 314 . In the preferred construction, upstanding, oval shaped wall member 305 comprises outwardly extending locking plates 301 and 302 extending from opposed walls of oval shaped wall member 305 . As detailed below, outwardly extending plates 301 and 302 provide frictional, locking interengagement with a corresponding locking wall formed on corner forming seam cover 400 . In this way, corner forming seam cover 400 and corner forming clip/bracket 300 are quickly and easily placed in secure locked engagement with each other in order to complete the assembly of retrofit decorative molding system 20 .
[0075] In the preferred embodiment, corner forming clip/bracket 300 also incorporates an upstanding U-shaped wall 317 which is mounted to base 314 in cooperating spaced relationship with oval shaped wall member 305 . In this way, a rigid construction is realized.
[0076] In its preferred construction, corner forming seam cover 400 comprises a generally rectangular shape which is established by plate 405 . In addition, plate 405 has a rear surface 406 and a front, forward facing surface 407 . Preferably, plate 405 also incorporates side forming flanges 408 and 409 which extend substantially perpendicularly from two adjacent side edges of plate 405 . Side edges 408 and 409 are constructed and are positioned for being placed in spaced, cooperating association with flanges 315 and 316 of clip/bracket 300 when corner forming seam cover 400 is mounted in place.
[0077] In order to provide a visually interesting, aesthetically pleasing, decorative visual appearance to each corner of the doorframe or window frame being reconstructed, corner forming seam cover 400 incorporates a unique, decorative, visually interesting surface construction on forward, front facing surface 407 . In this regard, virtually any desired visual configuration can be employed for the exposed panel of front surface 407 . As depicted in FIG. 13 , a raised panel configuration is shown for exemplary purposes only. However, other configurations such as interwoven strips, rosettes, logos, aesthetic shapes, designs, florettes, and the like may all be employed if desired. In addition, a miter simulating configuration can also be employed in order to provide the doorway or window frame with the visual appearance of a mitered joint.
[0078] Regardless of the configuration employed for surface 407 of corner forming seam cover 400 , it is important to note that in employing retrofit decorative molding system 20 of the present invention no components used in the construction need to be cut with a mitered configuration, as required in typically installed doorway and window frame configurations. Using the present invention, straight cuts and cover elements are employed which are easily cut and mounted in place, by individuals having ordinary skill. Furthermore, by employing the present invention, installation ease and convenience is also realized.
[0079] It is also important to recognize that the use of the present invention completely eliminates any need for adhesives while also eliminating the presence of any gaps or crevices that typically occur in prior art installations. In this way, an aesthetically pleasing and visually satisfying construction is achieved. Furthermore, no component employed in the present invention is secured in place by nails or screws which results in visible surface holes or apertures being formed. As a result, the aesthetic pleasing result of the present invention is further enhanced.
[0080] The construction of corner forming seam cover 400 is completed by incorporating locking wall 412 on rear surface 406 of plate 405 . In its preferred construction, locking wall 412 extends from surface 406 substantially perpendicularly therefrom and incorporates inside wall 413 and outside wall 414 .
[0081] As discussed above, inside wall 413 is constructed with a dimension for being mounted in cooperating association with oval shaped wall member 305 and being secured in place by engagement with locking plates 301 and 302 . By employing this construction, corner forming seam cover 400 is quickly and easily securely affixed to corner forming clip/bracket 300 by advancing locking wall 412 into secure locking engagement with oval shaped wall member 305 . Once in position, these components are secured and maintained in engagement with each other due to the frictional contact between the locking elements thereof. As a result, corner forming seam cover 400 is quickly and easily mounted in place, completing the desired installation of retrofit decorative molding system 20 of the present invention.
[0082] It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently obtained and, since certain changes may be made in the above article without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
[0083] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. | By providing a plurality of supporting clips which are quickly and easily mounted to the existing molding of a doorway or window frame and are constructed for receiving and supportingly retaining elongated, longitudinally extending decorative panels which are formed from a wide variety of decorative and visually distinctive appearances, a retrofit decorative molding system is achieved which is capable of being quickly and easily installed to any desired existing frame assembly by any unskilled individual, without requiring the use of mitered corners, abutting junctures, nails, adhesives, and the like. In addition, corner forming elements are employed to complete the construction. Furthermore, disassembly or removal of the existing components is required. By employing the combination of the components of the present invention, any desired frame assembly can be quickly and easily retrofitted with a completely installed decorative molding system for enhancing the visual and aesthetic appeal of any room or building. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 60/434,744, filed Dec. 19, 2002.
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to hearing aids and more particularly, to interactively modeling binaural shells for hearing aids.
2. Discussion of the Related Art
In most humans, hearing impairment occurs in both ears rather than a single ear. As a result, most humans require a hearing aid for both ears in order to compensate for their hearing loss. Hearing aids, however, are typically custom made because most humans have different levels of hearing loss and different inner canal, meatus and/or concha structures.
In order to manufacture a hearing aid or pair thereof, a health care professional takes impressions of a patient's left and right ears, which are duplicates of the contours of the patient's ears, and then forwards these impressions to a hearing aid manufacturer. The hearing aid manufacturer then replicates the impressions into, for example, hearing aid shells so they will fit the patient and, then installs electronic hearing components into the shells thus completing the manufacturing process.
In an effort to streamline the above manufacturing process, several computerized methods of manufacture have been developed. These methods commonly referred to as electronic modeling systems include sundry electronic detailing and modeling procedures, which are used to aid in the manufacture of hearing aid shells. These methods, however, typically manufacture each shell separately thus leading to inconsistencies between the shells resulting in increased production time and cost.
SUMMARY OF THE INVENTION
The present invention overcomes the foregoing and other problems encountered in the known teachings by providing a system and method for interactively modeling binaural shells for hearing aids.
In one embodiment of the present invention, a method for modeling binaural shells for hearing aids comprises the steps of loading data associated with a first and a second ear shell, registering the data associated with the first and the second ear shells, processing the first ear shell, storing data associated with the processing of the first ear shell, mapping the data associated with the processing of the first ear shell to the second ear shell, and adjusting the mapped second ear shell.
In another embodiment of the present invention, a system for modeling binaural shells for hearing aids comprises a memory device for storing a program, a processor in communication with the memory device, the processor operative with the program to load data associated with a first and a second ear shell, register the data associated with the first and the second ear shells, process the first ear shell, store data associated with the processing of the first ear shell, map the data associated with the processing of the first ear shell to the second ear shell, and adjust the mapped second ear shell.
In yet another embodiment of the present invention, a computer program product comprising a computer useable medium having computer program logic recorded thereon for modeling binaural shells for hearing aids, the computer program logic comprises program code for loading data associated with a first and a second ear shell, program code for registering the data associated with the first and the second ear shells, program code for processing the first ear shell, program code for storing data associated with the processing of the first ear shell, program code for mapping the data associated with the processing of the first ear shell to the second ear shell, and program code for adjusting the mapped second ear shell.
In another embodiment of the present invention, a system for modeling binaural shells for hearing aids, comprises a means for loading data associated with a first and a second ear shell, a means for registering the data associated with the first and the second ear shells, a means for processing the first ear shell, a means for storing data associated with the processing of the first ear shell, a means for mapping the data associated with the processing of the first ear shell to the second ear shell, and a means for adjusting the mapped second ear shell.
In yet another embodiment of the present invention, a method for modeling binaural shells for hearing aids, comprises loading data associated with a first ear shell, processing the first ear shell, storing data associated with the processing of the first ear shell, loading data associated with a second ear shell, registering the first and second ear shells, mapping the data associated with the processing of the first ear shell to the right ear shell, and interactively adjusting the mapped second ear shell.
In another embodiment of the present invention, a method for modeling binaural shells for hearing aids, comprises loading data associated with a first and a second ear shell that has been obtained by scanning an auditory canal, concha, or meatus of an ear, registering the data associated with the first and the second ear shells to represent the surface of the loaded data as a three-dimensional model, processing the first ear shell by performing a detailing and/or modeling procedure on the first ear shell, storing data associated with the processing of the first ear shell in a database and/or memory, mapping the data associated with the processing of the first ear shell to the second ear shell so that the processing that occurred on the first ear shell is performed on the second ear shell, and interactively adjusting the mapped second ear shell via an input means to compensate for an inconsistency in the mapped second ear shell.
The foregoing advantages and features are of representative embodiments and are presented to assist in understanding the invention. It should be understood that they are not intended to be considered limitations on the invention as defined by the claims, or limitations on equivalents to the claims. Therefore, this summary of features and advantages should not be considered dispositive in determining equivalents. Additional features and advantages of the invention will become apparent in the following description, from the drawings and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an electronic modeling system according to an exemplary embodiment of the present invention;
FIG. 2 is an ear impression that has been scanned according to an exemplary embodiment of the present invention;
FIG. 3 illustrates a surface reconstruction according to an exemplary embodiment of the present invention;
FIG. 4 illustrates a bottom line cut according to an exemplary embodiment of the present invention;
FIG. 5 illustrates a bottom line open cut according to an exemplary embodiment of the present invention;
FIG. 6 illustrates a rounding according to an exemplary embodiment of the present invention;
FIG. 7 illustrates a tapering according to an exemplary embodiment of the present invention;
FIG. 8 illustrates a local offsetting according to an exemplary embodiment of the present invention;
FIG. 9 illustrates an ipsilateral routing of signal (I-ROS) cutting according to an exemplary embodiment of the present invention;
FIG. 10 illustrates a detailed hearing aid shell according to an exemplary embodiment of the present invention;
FIG. 11 illustrates an adjusted wall thickness according to an exemplary embodiment of the present invention;
FIG. 12 illustrates a faceplate and centerline according to an exemplary embodiment of the present invention;
FIG. 13 illustrates an integrated faceplate according to an exemplary embodiment of the present invention;
FIG. 14 illustrates a ventilation channel according to an exemplary embodiment of the present invention;
FIG. 15 illustrates a receiver hole according to an exemplary embodiment of the present invention;
FIG. 16 illustrates collision detection according to an exemplary embodiment of the present invention;
FIG. 17 illustrates labeling according to an exemplary embodiment of the present invention;
FIG. 18 is a flowchart illustrating binaural electronic modeling according to an exemplary embodiment of the present invention; and
FIG. 19 is a flowchart illustrating binaural electronic modeling according to another exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
FIG. 1 is a block diagram of an electronic modeling system 100 according to an exemplary embodiment of the present invention. As shown in FIG. 1 , the modeling system 100 includes, inter alia, a three-dimensional (3D) scanner 105 , a central processing unit (CPU) 110 and a prototyping machine (i.e., prototyper) 115 . The CPU 110 includes a memory 120 and is operatively connected to an input 135 and an output 140 .
The memory 120 includes a random access memory (RAM) 125 and a read only memory (ROM) 130 . The memory 120 can also include a database, disk drive, tape drive, etc., or a combination thereof. The RAM 125 functions as a data memory that stores data used during the execution of the program in the CPU 110 and is used as a work area. The ROM 130 functions as a program memory for storing a program executed in the CPU 110 . The input 135 is constituted by a keyboard, mouse, etc. and the output 140 is constituted by a liquid crystal display (LCD), cathode ray tube (CRT) display, printer, etc.
The scanner 105 , which is used to scan an impression of an ear, may communicate directly to the CPU 110 via a wired and/or wireless connection or in-directly via a database 145 or a server. The database 145 may be connected to the scanner 105 or the CPU 110 via a local area network (LAN), wide area network (WAN) or the internet, etc. The scanner 105 may be an optical, ultrasound, magnetic resonance (MR) or computed tomographic (CT) type 3D scanner.
The prototyper 115 , which is used to model a hearing aid shell, may communicate directly with the CPU 110 via a wired and/or wireless connection or in-directly via a database 150 or a server. The database 150 may also be connected to the prototyper 115 or the CPU 110 via a LAN, WAN or the internet, etc. The prototyper 115 may produce a physical version of the hearing aid shell using a prototyping/modeling technique such as Milling, stereo lithography, solid ground curing, selective laser sintering, direct shell production casting, 3D-printing, topographic shell fabrication, fused deposition modeling, inkjet modeling, laminated object manufacturing, nano-printing, etc.
An electronic detailing and modeling procedure for interactively modeling binaural shells for hearing aids in accordance with the present invention will now be described. It is to be understood, however, that other electronic detailing and/or modeling procedures may be used in accordance with the present invention to model binaural shells for hearing aids. In addition, the following procedures may be performed in a number of different sequences with satisfying results.
The electronic detailing procedure of the present invention uses several functions to model binaural shells based on data related to a patient's ear impressions such as surface reconstruction, line cut, canal tapering, local relaxing, canal extension, band selection, offset, etc. In the first step of the procedure, data associated with a patient's ear impressions is loaded into the CPU 110 , memory 120 or database 145 (of FIG. 1 ). This is accomplished by scanning the patient's ear impressions using the 3D scanner 105 (of FIG. 1 ) and storing the data in a format such as point cloud format (i.e., .ASC) or stereo lithography format (i.e., .STL), etc. FIG. 2 illustrates an ear impression that has been scanned in point cloud format.
Included in the loading procedure is a surface reconstruction of the scanned ear impression. An example surface reconstruction of the scanned ear impression is shown in FIG. 3 . A surface reconstruction is typically used because data from the 3D scanner 105 may consist of certain outliers, noise and holes, which result in an incomplete or inadequate surface model of the impression. In order to reconstruct the surface, a robust data pre-processing method (e.g., rapid triangulation, 3D alpha shape, delaunay mesh generation, Quickhuall, voronori, etc.) is implemented to remove the outliers, reduce the noise and fill small holes while preserving the original geometry of the surface model (i.e., impression shell). The surface reconstruction may additionally remove a number of defects resulting from different sources such as scars, earwax, tissue, or hair in the ear.
Subsequent to the creation of the surface model, a number of modifications and/or processing steps are performed to create a final model of the hearing aid shell to be manufactured. One of the first modifications performed on the surface model of the hearing aid shell is a line cut function and/or procedure for reducing the model (i.e., impression shell) to a desired size and shape. This is accomplished by defining a cutting plane that divides the impression shell into two parts and, removing a portion of the impression that is not desired. The line cut also includes several functions such as, open line cut, close line cut and rounding. All of which may be used to modify the impression shell. Open line cut is used to cut the impression at specified positions resulting in an open model at the area of application. Close line cut is similar to the open line cut; however, it has an additional step that fills open contours at specified cutting positions resulting in a closed impression at the area of application.
An example of a bottom line cut with filling is shown in FIG. 4 . As shown in FIG. 4 , a cutting plane is defined, which intersects the impression shell at a desired position, and the area below the cutting plane is removed. Then the open intersect contour is filled. An example of a bottom line open cut is shown in FIG. 5 . As shown in FIG. 5 , a cutting plane is defined, which intersects the impression shell at a desired position, and the area below the cutting plane is removed. The bottom contour is left un-filled. The rounding function allows an impression cut followed by predetermined levels of rounding. In other words, this function replaces the planar surface resulting from the line close cut with a rounded interpolated surface that captures the curvature of the impression. An example of rounding is shown in FIG. 6 . As shown in FIG. 6 , after using the rounding function, the right area of an impression shell is removed. In addition, the cutting area is filled with a rounded interpolated surface.
After performing the line cut and its associated functions, the impression shell may be further modified by using tapering and extension functions. The tapering function is used to trim the canal tip (of the ear canal) if it is overly extended and taper the resulting impression. The tapering function as shown in FIG. 7 is typically used to smooth the edge of a line following a close cut operation. In contrast to tapering, extension is used to extend the canal along the topology of the canal tip when the resulting canal is too short.
Additional modifications to the impression shell may also be performed during the electronic detailing process. These modifications are accomplished through use of the following functions, inter alia: (1) local relaxing; (2) band selection; (3) offset and (4) ipsilateral routing of signal (I-ROS) cutting. Local relaxing is used to remove additional bumps, artifacts or voids or fill up dimples or depressions in the resulting impression shell by implementing the relaxation on a selected local surface area (e.g., a region of interest) and recovering the surface. Band selection is used to provide more specific band-like shapes around the impression and is typically used in conjunction with an offset to apply changes (e.g., expansion and shrinkage) to the specified band of the impression. Offset is used to make volumetric changes such as expansion and shrinkage in the impression for fitting assessment and remarks. This function has two modes: (1) local offset and (2) global offset. In local offset only the selected portion of an impression will be changed as indicated by the shaded area in FIG. 8 whereas in global offset the entire impression may be changed. I-ROS utilizes a non-occluding design without contralateral routing and is used to create impressions for patients with mild to moderate high frequency hearing loss. As shown in FIG. 9 , I-ROS cutting is performed, whereby the upper right hand corner of the ear impression is removed as indicated by the perpendicular cut. Upon completion of detailing the detailed impression (as shown in FIG. 10 ) is transferred to a point cloud or stereo lithographic format and stored in a CPU, database or memory for future use, particularly for electronic modeling of the hearing aid shell.
Upon completion of the electronic detailing procedure, an electronic modeling procedure is undertaken to create a physical version of the detailed impression. The electronic modeling procedure for use with the present invention performs several operations on the detailed impression such as adjusting its wall thickness, integrating a faceplate, forming a vent channel and receiver holes, labeling, collision detection, etc. to create the physical version of the detailed impression.
One of the first operations undertaken on the impression shell is to optimize the impression's geometry. As shown in FIG. 11 , the detailed impression's (of FIG. 10 ) wall thickness is modified in order to increase the strength and stability of the impression. Another operation that may be performed on the impression is to apply a face or cover plate to the impression. FIGS. 12 and 13 illustrate a faceplate and an impression with the faceplate integrated thereto. In order to integrate the faceplate to the impression an area is created for the faceplate by cutting away part of the impression. This area is carefully configured so that the faceplate will be in alignment with electronic hearing components that are or will be placed in the impression. Once the cutting is complete the faceplate is applied to the impression.
In order to ensure proper performance of the physical version of the impression, a pressure compensation/ventilation channel or a sound bore are created. FIG. 14 illustrates a ventilation channel that runs for example, inside the impression. Similarly, electronic components should be easily connected. FIG. 15 illustrates a receiver hole that is used to connect a transducer tube to other components of the impression.
Component placement is an additional process undertaken during electronic modeling. It is typically an iterative process in which components are placed on or in the impression until an acceptable arrangement is obtained. Several design tools are used to assist in component placement such as locking and placing components in relation to the impression surface and collision detection (as shown in FIG. 16 ) so that components do not interfere with each other or the impression. After the modeling process is complete, a unique identifier is typically placed on the physical version of the impression. FIG. 17 illustrates the labeling of an earpiece. The label or identifier may be a serial number, barcode or color code, etc.
FIG. 18 is a flowchart illustrating binaural electronic modeling according to an exemplary embodiment of the present invention. As shown in FIG. 18 , data from a left ear shell is loaded into the CPU 110 (step 1805 ). Subsequently, the data from a right ear shell is loaded into the CPU 110 (step 1810 ). As discussed above with reference to FIGS. 2 and 3 the data from the left and right ear shells is loaded by first acquiring a physical ear impression of a patient's ear from a medical professional and then scanning the data with the scanner 105 . The scanned data is stored in a point cloud, stereo lithographic, rhino, wavefront, etc. format and is then transmitted to the CPU 110 . Once the data is in the CPU 110 it is reconstructed to form a pair of 3D surface shell models. The 3D models of the shells are geometric surfaces parameterized by a set of vertices, which are connected to each other by triangles. The 3D models of the shells are viewed by an operator via an output device 140 (of FIG. 1 ) such as a cathode ray tube (CRT) display. It is to be understood that the process described with reference to FIG. 18 , is almost fully automated and may handle most of the steps with no or very little operator interaction. The operator, however, may interact when necessary via an input device 135 (of FIG. 1 ) such as a keyboard or a personal digital assistant (PDA).
After the left and right ear shells are loaded into the CPU 110 , they are registered using for example, a feature-based, point based, model based or global similarity registration (step 1815 ). During registration the parameterized set of vertices or triangles (i.e., vertex/triangle) associated with the shells is stored in a memory 120 and/or database 145 (of FIG. 1 ). This enables the determination of the transformation matrix between two shells and thus, the corresponding vertex/triangle in one shell and a vertex/triangle in another shell can be located. Once in the memory 120 or database 145 , the data associated with the features of the left and right ear are stored in corresponding registration fields. For example, the data associated with the left ear canal and concha and the data associated with the right ear canal and concha are stored in left and right ear fields corresponding to canal and concha, respectively. It is to be understood that the registration fields are also used to store data for general ear features such as curvature, moments, principle vectors, etc. or specific ear features such as canal, canal tip, base, helix/anti-helix, concha, tragus/anti-tragus, etc.
As shown in FIG. 18 , after the left and right ear shells have been registered modeling begins on the left ear shell (step 1820 ). It is to be understood that any number of modeling steps and/or functions may take place in step 1820 including but not limited to detailing steps such as line cut, tapering, extension, relaxing, offsetting, etc. and modeling steps such as adjusting wall thickness, integrating a faceplate, forming a vent channel and receiver holes, labeling, collision detection, etc. In addition, the detailing and modeling steps may take place in any order and the modeling in step 1820 may begin on the right ear. It is to be understood, however, that the detailing steps are to be completed before executing the modeling steps. For exemplary purposes, however, a detailing step such as a line cut takes place in step 1820 . After the line cut takes place its status and parameters (e.g., the parameters associated with the location of the cutting plane where the line cut took place) are recorded and stored in a memory such as a RAM 125 (of FIG. 1 ) (step 1825 ).
As further shown in FIG. 18 , the data stored in step 1825 is then mapped to the right ear shell (step 1830 ). This is accomplished by recording the position of the operation (e.g., recording the operation name and parameters) in step 1820 and using the registration data (e.g., the transformation matrix) to determine the corresponding position on the right ear shell where the operation will take place. The recorded operation will then be performed on the right ear shell. In other words, the data associated with the line cut that was applied to the left ear shell in step 1820 is now applied to the right ear shell so that the same line cut takes place on the right ear shell. After step 1830 , an operator interactively adjusts the resulting mapped right ear shell via an input 135 (of FIG. 1 ) (step 1835 ). Thus, for example, the operator manually adjusts the cutting plane resulting from the mapped line cut in an up and/or down position to compensate for any error introduced during the mapping step 1830 .
Subsequently, an additional detailing step takes place (step 1840 ). As discussed above with reference to step 1820 any number of detailing and/or modeling procedures may take place in step 1840 and in any order. For this discussion, however, another detailing step such as a tapering, takes place on the left ear shell in step 1840 . After the tapering takes place the status and parameters of the tapering are stored (step 1845 ) and then mapped to the right ear shell (step 1850 ). Both of these steps are similar to or the same as steps 1825 and 1830 but with different data being involved. Following the mapping step 1850 , an operator interactively adjusts the resulting ear shell (step 1855 ) and the finalized shells are stored in a database, output to the operator for review, or the steps 1820 – 1855 are repeated to include any number of additional detailing modifications necessary to result in a satisfactory ear shell.
FIG. 19 is a flowchart illustrating binaural electronic modeling according to another exemplary embodiment of the present invention. For purposes of discussion a modeling process is described rather than a detailing process, however, the following steps are applicable to detailing as well. As shown in FIG. 19 , data from a left ear shell is loaded into the CPU 110 (step 1905 ) and then modeled (e.g., the left shell's wall thickness is modified) in step 1910 . After the modeling is complete the data associated with the process is stored in the RAM 125 (step 1915 ) and another modeling takes place (e.g., inserting a label onto the shell) (step 1920 ). Subsequently, the data from step 1920 's modeling is stored in the RAM 125 (step 1925 ) and the left ear shell model is completed.
As shown in FIG. 19 , after modeling the left ear shell, the data associated with the right ear shell is loaded into the CPU 110 (step 1930 ). The left and right ear shells are then registered (step 1935 ) and the modeling from step 1910 is mapped to the right ear shell (step 1940 ). An operator then manually adjusts the resulting right ear shell (step 1945 ). After step 1945 , the modeling from step 1920 is mapped to the right ear shell ( 1950 ) and if necessary an operator manually adjusts the resulting right ear shell (step 1955 ) and the ear shell models are output via an output device 140 or stored in the memory 120 or a database 150 (of FIG. 1 ).
It is to be understood that the present invention may be implemented in various forms of hardware, software, firmware, special purpose processors, or a combination thereof. In one embodiment, the present invention may be implemented in software as an application program tangibly embodied on a program storage device. The application program may be uploaded to, and executed by, a machine comprising any suitable architecture.
It is to be further understood that, because some of the constituent system components and method steps depicted in the accompanying figures may be implemented in software, the actual connections between the system components (or the process steps) may differ depending on the manner in which the present invention is programmed. Given the teachings of the present invention provided herein, one of ordinary skill in the art will be able to contemplate these and similar implementations or configurations of the present invention.
It should also be understood that the above description is only representative of illustrative embodiments. For the convenience of the reader, the above description has focused on a representative sample of possible embodiments, a sample that is illustrative of the principles of the invention. The description has not attempted to exhaustively enumerate all possible variations. That alternative embodiments may not have been presented for a specific portion of the invention, or that further undescribed alternatives may be available for a portion, is not to be considered a disclaimer of those alternate embodiments. Other applications and embodiments can be straightforwardly implemented without departing from the spirit and scope of the present invention. It is therefore intended, that the invention not be limited to the specifically described embodiments, because numerous permutations and combinations of the above and implementations involving non-inventive substitutions for the above can be created, but the invention is to be defined in accordance with the claims that follow. It can be appreciated that many of those undescribed embodiments are within the literal scope of the following claims, and that others are equivalent. | A system and method for modeling binaural shells for hearing aids, wherein the system is configured to load data associated with a first and a second ear shell. The system is further configured to register the data associated with the first and the second ear shells and process the first ear shell. The system is also configured to store data associated with processing the first ear shell and then map the data associated with processing the first ear shell to the second ear shell. Subsequently, the mapped second ear shell is interactively adjusted by an operator to compensate for an inconsistency in the mapped second ear shell. | 1 |
This application is a Divisional application of application Ser. No. 09/025,731, filed Feb. 18, 1998, now U.S. Pat. No. 6,171,892, which is a Divisional application of application Ser. No. 08/784,998, filed Jan. 17, 1997 now U.S. Pat. No. 5,798,551, the contents of which are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor integrated circuit device and a method for manufacturing the same and, more particularly, to a technique which is particularly effective when applied to a semiconductor integrated circuit device having an SRAM (Static Random Access Memory).
A memory cell of an SRAM or a semiconductor memory device is composed of: a flip-flop circuit acting as an information storage unit for storing information of 1 bit; and a pair of transfer MISFETs (Metal Insulator Semiconductor Field Effect Transistors) for controlling the electrical connection between writing/reading data lines and the flip-flop circuit.
The flip-flop circuit of the memory cell is composed of a pair of CMOS (Complementary Metal Oxide Semiconductor) inverters, for example. Each of these CMOS inverters is composed of one drive MISFET and one load MISFET. In this case, the memory cell is of a complete CMOS type of a combination of two drive MISFETs, two load MISFETs and two transfer MISFETs. Of these MISFETs, the transfer MISFETs and the drive MISFETs are of n-channel type whereas the load MISFETs are of p-channel type.
A pair of input/output terminals of the flip-flop circuit (the CMOS inverter) are cross-connected through a pair of wiring lines called “local wiring lines”, for example. Moreover, one of these input/output terminals is supplied with a power supply voltage (e.g., 3 V) of a circuit through a power supply voltage line whereas the other is supplied with a reference voltage (e.g., 0 V) of the circuit through a reference voltage line.
In U.S. Pat. No. 5,523,598, issued Jun. 4, 1996, there is disclosed an SRAM of the complete CMOS type, which is equipped with a pair of aforementioned local wiring lines. In this SRAM, the gate electrodes of the six MISFETs constituting the memory cells, the power supply voltage line connected with one input/output terminal of the flip-flop circuit, the reference voltage line connected with the other input/output terminal, the pair of local wiring lines, and the data lines connected with the drain regions of the transfer MISFETs are individually provided in different conductive layers. In this SRAM, moreover, the local wiring lines and other conductive layers (e.g., the reference voltage line) are arranged to intersect each other so that the reduction in the alpha particle soft error resistance, which might occur upon the miniaturization of the memory cell size and the lowering of the operating power supply voltage, is prevented by forming a capacitor element in the intersection region to increase the storage node capacitance of the memory cells.
SUMMARY OF THE INVENTION
Various problems arise in connection with the SRAM disclosed in U.S. Pat. No. 5,523,598. In the SRAM disclosed the reference voltage line, and the data lines are formed in different conductive layers. As a result, the mask registration allowance when forming the connection holes in the interlayer insulating film by using a photoresist as the mask is increased, resulting in increase of the memory cell size. When the gate electrodes are formed of a conductive film of a first layer, the local wiring lines are formed of a conductive film of a second layer, and the power supply lines are formed of a conductive film of a third layer, for example, it is necessary to ensure the registration allowance for both the gate electrodes and the local wiring lines.
In the SRAM disclosed in the aforementioned U.S. Pat. No. 5,523,598, the paired local wiring lines are formed of the same conductive film. This makes it necessary to arrange the two local wiring lines transversely in the memory cell, so that the memory cell size is increased.
An object of the present invention is to provide a semiconductor integrated circuit device (for example, a semiconductor memory such as a complete CMOS SRAM) having a reduced memory cell size, and a method of fabricating such semiconductor device.
Another object of the present invention is to provide a semiconductor integrated circuit device (e.g., semiconductor memory such as a complete CMOS SRAM) having improved alpha particle soft error resistance, and a method of fabricating such semiconductor device. particle soft error resistance, and a method of fabricating such semiconductor device.
The aforementioned and other objects and novel features of the present invention will become apparent from the following description to be made with reference to the accompanying drawings.
Illustrations of the invention to be disclosed herein will be briefly described in the following. These illustrations are representative of the present invention and do not define the scope thereof, the scope being defined by the appended claims.
According to the present invention, there is provided a semiconductor integrated circuit device comprising an SRAM including memory cells having a flip-flop circuit composed of a pair of drive MISFETs and a pair of load MISFETs, and having a pair of transfer MISFETs, which device is constructed such that the individual gate electrodes of the drive MISFETs, the load MISFETs and the transfer MISFETs are composed of a first conductive film formed over a major face of a semiconductor substrate; one of the local wiring lines cross-connecting a pair of input/output terminals of the flip-flop circuit, is composed of a second conductive film formed over that first conductive film; and the other of the local wiring lines is composed of a third conductive film formed over the second conductive film, and a method of fabricating the device.
The semiconductor integrated circuit device of the present invention is constructed such that the one and the other of the local wiring lines are so arranged as to have at least partially and vertically overlapping portions, and the one and the other of the local wiring lines and an insulating film interposed therebetween constitute a capacitor element.
In regard to a method for manufacturing a semiconductor integrated circuit device, there is provided a method for manufacturing a semiconductor integrated circuit device (e.g., an SRAM) containing memory cells each having a flip-flop circuit including a pair of drive MISFETs and a pair of load MISFETs, and a pair of transfer MISFETs, comprising the steps of:
(a) preparing (e.g., providing) a semiconductor substrate having a major face, over which the individual gate electrodes of the drive MISFETs, the load MISFETs and the transfer MISFETs are formed;
(b) forming a pair of local wiring lines cross-connecting a pair of input/output terminals of the flip-flop circuit, over the gate electrodes;
(c) forming side wall spacers on the individual side walls of the gate electrodes and the local wiring lines; and
(d) forming connection holes reaching the source regions of the drive MISFETs or the load MISFETs by depositing a second insulating film of an etching rate different from (e.g., greater than) that of the first insulating film over the local wiring lines, on which the side wall spacers are formed, and by etching the second insulating film. Also provided is the device fabricated by this method.
In regard to a method for manufacturing a semiconductor integrated circuit device, there is also provided a method for manufacturing a semiconductor integrated circuit device (e.g., an SRAM) containing memory cells each having a flip-flop circuit composed of a pair of drive MISFETs and a pair of load MISFETs, and a pair of transfer MISFETs, comprising the steps of:
(a) preparing (e.g., providing) a semiconductor substrate having a major face, over which the individual gate electrodes of the drive MISFETs, the load MISFETs and the transfer MISFETs are formed;
(b) forming one of a pair of local wiring lines cross-connecting a pair of input/output terminals of the flip-flop circuit, over the gate electrodes;
(c) forming the other of the paired local wiring lines over the local wiring line formed in step (d);
(d) forming side wall spacers on the individual side walls of the gate electrodes and the one and the other of the local wiring lines, by etching a first insulating film which is deposited over the other of the local wiring lines; and
(e) forming connection holes reaching the source regions of the drive MISFETs or the load MISFETs by depositing a second insulating film of an etching rate different from that of the first insulating film over the other of the local wiring lines, on which the side wall spacers are formed, and by etching the second insulating film. Also provided is the device fabricating by this method.
According to the means thus far described, the paired local wiring lines cross-connecting the input/output terminals of the flip-flop circuit of the memory cell are formed in different conductive layers vertically with respect to the substrate. Therefore the space, required when the paired local wiring lines are composed of the same conductive film, for arranging the two local wiring lines transversely, can be eliminated, and the local wiring lines can be arranged partially in an overlapping manner, thereby reducing the area occupied by the memory cell.
According to the means thus far described, the one and the other of the local wiring lines are so arranged as to overlap vertically, and a capacitor element is formed of the one and the other of the local wiring lines and an insulating film interposed therebetween, so that the storage node capacitance of the memory cell can be increased, preventing the lowering of alpha particle soft error resistance entailed by the miniaturization of the memory cell size and the lowering of the operation power supply voltage. For example, the capacitor area can be about half the area of the memory cell, which realizes a thick capacitor dielectric. Soft error immunity can be achieved even at a 1.8 V supply voltage.
According to the means thus far described, the mask registration allowance when the connection holes are formed in the interlayer insulating film by using a photoresist as the mask can be eliminated, reducing the area occupied by the memory cells. The connection holes can be formed by a self-alignment technique (self-aligned to both the gates and the local wiring lines).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view showing a memory cell of an SRAM of a first embodiment according to the present invention.
FIG. 2 is a section of the memory cell taken along line A-A′ of FIG. 1 .
FIG. 3 is a section of the memory cell taken along line B-B′ of FIG. 1 .
FIG. 4 is a top plan view showing the memory cell (for about four) of the SRAM of this first embodiment according to the present invention.
FIG. 5 is an equivalent circuit diagram of the memory cell of the SRAM of the first embodiment according to the present invention.
FIG. 6 is a top plan view showing a method for manufacturing the memory cell of the SRAM of the first embodiment according to the present invention.
FIGS. 7 ( a ) and 7 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIGS. 8 ( a ) and 8 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIG. 9 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIGS. 10 ( a ) and 10 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIGS. 11 ( a ) and ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIG. 12 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIGS. 13 ( a ) and ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIG. 14 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIGS. 15 ( a ) and 15 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIGS. 16 ( a ) and 16 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of the first embodiment according to the present invention.
FIG. 17 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIGS. 18 ( a ) and 18 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIG. 19 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIGS. 20 ( a ) and 20 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIG. 21 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIGS. 22 ( a ) and 22 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIG. 23 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIGS. 24 ( a ) and 24 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIG. 25 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIGS. 26 ( a ) and 26 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIG. 27 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIG. 28 is a section showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIG. 29 is a section showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIG. 30 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIG. 31 is a section showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIG. 32 is a section showing the method for manufacturing the memory cell of the SRAM of this first embodiment according to the present invention.
FIG. 33 is a top plan view showing a memory cell of an SRAM of a second embodiment according to the present invention.
FIG. 34 is a section of the memory cell taken along line A-A′ of FIG. 33 .
FIG. 35 is a section of the memory cell taken along line B-B′ of FIG. 33 .
FIG. 36 is an equivalent circuit diagram showing the memory cell of the SRAM of this second embodiment according to the present invention.
FIG. 37 is a top plan view showing a method for manufacturing the memory cell of the SRAM of this second embodiment according to the present invention.
FIGS. 38 ( a ) and 38 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this second embodiment according to the present invention.
FIG. 39 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this second embodiment according to the present invention.
FIGS. 40 ( a ) and 40 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this second embodiment according to the present invention.
FIG. 41 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this second embodiment according to the present invention.
FIGS. 42 ( a ) and 42 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this second embodiment according to the present invention.
FIG. 43 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this second embodiment according to the present invention.
FIGS. 44 ( a ) and 44 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this second embodiment according to the present invention.
FIG. 45 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this second embodiment according to the present invention.
FIGS. 46 ( a ) and 46 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this second embodiment according to the present invention.
FIG. 47 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this second embodiment according to the present invention.
FIGS. 48 ( a ) and 48 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this second embodiment according to the present invention.
FIG. 49 is a top plan view showing a method for manufacturing a memory cell of an SRAM of a third embodiment according to the present invention.
FIG. 50 is a section showing the method for manufacturing the memory cell of the SRAM of this third embodiment according to the present invention.
FIG. 51 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this third embodiment according to the present invention.
FIG. 52 is a section showing the method for manufacturing the memory cell of the SRAM of this third embodiment according to the present invention.
FIG. 53 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this third embodiment according to the present invention.
FIG. 54 is a section showing the method for manufacturing the memory cell of the SRAM of this third embodiment according to the present invention.
FIG. 55 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this third embodiment according to the present invention.
FIG. 56 is a section showing the method for manufacturing the memory cell of the SRAM of this third embodiment according to the present invention.
FIG. 57 is a section showing the method for manufacturing the memory cell of the SRAM of this third embodiment according to the present invention.
FIG. 58 is a section showing the method for manufacturing the memory cell of the SRAM of this third embodiment according to the present invention.
FIG. 59 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this third embodiment according to the present invention.
FIG. 60 is a section showing the method for manufacturing the memory cell of the SRAM of this third embodiment according to the present invention.
FIG. 61 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this third embodiment according to the present invention.
FIG. 62 is a section showing the method for manufacturing the memory cell of the SRAM of this third embodiment according to the present invention.
FIG. 63 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this third embodiment according to the present invention.
FIG. 64 is a section showing the method for manufacturing the memory cell of the SRAM of this third embodiment according to the present invention.
FIG. 65 is a top plan view showing a method for manufacturing a memory cell of an SRAM of a fourth embodiment according to the present invention.
FIG. 66 is a section showing the method for manufacturing the memory cell of the SRAM of this fourth embodiment according to the present invention.
FIG. 67 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this fourth embodiment according to the present invention.
FIG. 68 is a section showing the method for manufacturing the memory cell of the SRAM of this fourth embodiment according to the present invention.
FIG. 69 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this fourth embodiment according to the present invention.
FIG. 70 is a section showing the method for manufacturing the memory cell of the SRAM of this fourth embodiment according to the present invention.
FIG. 71 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this fourth embodiment according to the present invention.
FIG. 72 is a section showing the method for manufacturing the memory cell of the SRAM of this fourth embodiment according to the present invention.
FIG. 73 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this fourth embodiment according to the present invention.
FIG. 74 is a section showing the method for manufacturing the memory cell of the SRAM of this fourth embodiment according to the present invention.
FIG. 75 is a section showing the method for manufacturing the memory cell of the SRAM of this fourth embodiment according to the present invention.
FIG. 76 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this fourth embodiment according to the present invention.
FIG. 77 is a section showing the method for manufacturing the memory cell of the SRAM of this fourth embodiment according to the present invention.
FIG. 78 is a section showing the method for manufacturing the memory cell of the SRAM of this fourth embodiment according to the present invention.
FIG. 79 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this fourth embodiment according to the present invention.
FIG. 80 is a section showing the method for manufacturing the memory cell of the SRAM of this fourth embodiment according to the present invention.
FIG. 81 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this fourth embodiment according to the present invention.
FIG. 82 is a section showing the method for manufacturing the memory cell of the SRAM of this fourth embodiment according to the present invention.
FIG. 83 is a top plan view showing the method for manufacturing a memory cell of the SRAM of a fifth embodiment according to the present invention.
FIGS. 84 ( a ) and 84 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this fifth embodiment according to the present invention.
FIG. 85 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this fifth embodiment according to the present invention.
FIGS. 86 ( a ) and ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this fifth embodiment according to the present invention.
FIG. 87 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this fifth embodiment according to the present invention.
FIGS. 88 ( a ) and 88 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this fifth embodiment according to the present invention.
FIG. 89 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this fifth embodiment according to the present invention.
FIGS. 90 ( a ) and 90 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this fifth embodiment according to the present invention.
FIGS. 91 ( a ) and 91 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this fifth embodiment according to the present invention.
FIG. 92 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this fifth embodiment according to the present invention.
FIGS. 93 ( a ) and 93 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this fifth embodiment according to the present invention.
FIG. 94 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this fifth embodiment according to the present invention.
FIGS. 95 ( a ) and 95 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this fifth embodiment according to the present invention.
FIG. 96 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this fifth embodiment according to the present invention.
FIGS. 97 ( a ) and 97 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this fifth embodiment according to the present invention.
FIG. 98 is a top plan view showing the method for manufacturing a memory cell of the SRAM of a sixth embodiment according to the present invention.
FIGS. 99 ( a ) and 99 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this sixth embodiment according to the present invention.
FIG. 100 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this sixth embodiment according to the present invention.
FIGS. 101 ( a ) and 101 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this sixth embodiment according to the present invention.
FIG. 102 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this sixth embodiment according to the present invention.
FIGS. 103 ( a ) and 103 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this sixth embodiment according to the present invention.
FIG. 104 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this sixth embodiment according to the present invention.
FIGS. 105 ( a ) and 105 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this sixth embodiment according to the present invention.
FIGS. 106 ( a ) and 106 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this sixth embodiment according to the present invention.
FIGS. 107 ( a ) and 107 ( b ) are sections showing the method for manufacturing the memory cell of the SRAM of this sixth embodiment according to the present invention.
FIG. 108 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this sixth embodiment according to the present invention.
FIG. 109 is a top plan view showing the method for manufacturing the memory cell of the SRAM of this sixth embodiment according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
While the present invention will be described in connection with specific and preferred embodiments, it will be understood that it is not intended to limit the invention to those embodiments. To the contrary, it is intended to cover all alterations, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
Throughout the present disclosure, where devices are described as including or comprising specific components, and methods are described as comprising or including specific steps, it is contemplated that devices of the present invention also consist essentially of, or consist of, the recited components, and methods of the present invention also consist essentially of, or consist of, the recited steps. Accordingly, throughout the present disclosure any described device or process can consist essentially of, or consist of, the recited components or steps.
The present invention will be described in detail in connection with its embodiments with reference to the accompanying drawings. Throughout all the drawings for explaining the embodiments, the portions having the same functions are designated by the same reference numerals, and their repeated description will be omitted.
Embodiment 1
FIG. 5 is an equivalent circuit diagram of a memory cell of an SRAM of a first embodiment of the present invention. This memory cell is arranged at the intersection between a pair of complementary data lines (a data line DL and a data line DL) and a word line WL and is composed of a pair of drive MISFETs Qd 1 and Qd 2 , a pair of load MISFETs Qp 1 and Qp 2 and a pair of transfer MISFETs Qt 1 and Qt 2 . Of these MISFETs, the drive MISFETs Qd 1 and Qd 2 and the transfer MISFETs Qt 1 and Qt 2 are of p-channel type, and the load MISFETs Qp 1 and Qp 2 are of p-channel type. In short, this memory cell is constructed of a complete CMOS type using four n-channel MISFETs and two p-channel MISFETs.
Of the six MISFETs constituting the aforementioned memory cell, the paired drive MISFETs Qd 1 and Qd 2 and the paired load MISFETs Qp 1 and Qp 2 constitute a flip-flop circuit acting as an information storing unit for storing information of 1 bit. One input/output terminal (a storage node) of this flip-flop circuit is electrically connected with one of the source and drain regions of the transfer MISFET Qt 1 , and the other input/output (i.e., a storage node) is electrically connected with one of the source and drain regions of the transfer MISFET Qt 2 .
The data line DL is electrically connected with the other of the source and drain regions of the transfer MISFET Qt 1 , and the data line DL is electrically connected with the other of the source and drain regions of the transfer MISFET Qt 2 . Moreover, one end (each source region of the load MISFETs Qp 1 and Qp 2 ) of the flip-flop circuit is connected with the power supply voltage (Vcc), and the other (each source region of the drive MISFETs Qd 1 and Qd 2 ) is connected with a reference voltage Vss. The power supply voltage (Vcc) is, e.g., 3 V whereas the reference voltage (Vss) is, e.g., 0 V (GND).
The input/output terminals of the flip-flop circuit are cross-connected through a pair of local wiring lines L 1 and L 2 . In the present embodiment, these paired local wiring lines L 1 and L 2 are arranged in different conductive layers, as will be described hereinafter.
A specific construction of the memory cell will be described with reference to FIG. 1 (a top plan view of about one memory cell), FIG. 2 (a section taken along line A-A′ of FIG. 1 ), FIG. 3 (a section taken along line B-B′ of FIG. 1) and FIG. 4 (a top plan view of about four memory cells). Incidentally, FIGS. 1 and 4 show only connection holes for connecting the conductive layer constituting the memory cell and upper and lower conductive layers but omit the insulating films isolating the individual conductive layers.
The six MISFETs constituting the memory cell are formed in the active region which is surrounded by an element isolating groove 2 of a semiconductor substrate 1 made of single crystalline silicon. The drive MISFETs Qd 1 and Qd 2 and the transfer MISFETs Qt 1 and Qt 2 of n-channel type are formed in the active region of a p-type well 3 , and the load MISFETs Qp 1 and Qp 2 of p-channel type are formed in the active region of an n-type well 4 .
Each of the paired transfer MISFETs Qt 1 and Qt 2 include n-type semiconductor regions 5 and 5 (the source region and the drain region) formed in the active region of the p-type well 3 , a gate oxide film 6 formed on the surface of the active region, and a gate electrode 7 formed over the gate oxide film 6 . The individual gate electrodes 7 of the transfer MISFETs Qt 1 and Qt 2 are constructed so as to have a polycide structure, in which an n-type polycrystalline silicon film and a W (tungsten) silicide (WSi 2 ) film are stacked, for example, and are integrated with the word line WL. This word line WL is extended in a first direction (in the lateral direction of FIGS. 1 and 4 ), and the paired transfer MISFETs Qt 1 and Qt 2 are arranged adjacent to each other in the first direction. The paired transfer MISFETs Qt 1 and Qt 2 are so arranged that their gate length direction is a second direction (the vertical direction of FIGS. 1 and 4) perpendicular to the first direction.
Channel forming regions of the transfer MISFETs Qt 1 and Qt 2 are formed, in the active region of the p-type well 3 , under the gate electrodes 7 thereof and between n-type semiconductor regions 5 and 5 .
Each of the paired drive MISFETs Qd 1 and Qd 2 is composed of the n-type semiconductor regions 5 and 5 (the source region and the drain region) formed in the active region of the p-type well 3 , the gate oxide film 6 formed on the surface of the active region, and a gate electrode 8 formed over the gate oxide film 6 . The n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 1 is formed in the active region shared with the n-type semiconductor region (one of the source region and the drain region) of the transfer MISFET Qt 1 , and the n-type semiconductor region 5 (the drain region) of the n-type semiconductor region 5 of the drive MISFET Qd 2 is formed in the active region shared with the n-type semiconductor region 5 (one of the source region and the drain region) of the transfer MISFET Qt 2 . The individual gate electrodes 8 of the drive MISFETs Qd 1 and Qd 2 are, illustratively, made to have a polycide structure in which an n-type polycrystalline silicon film and a silicide film are stacked, for example.
Channel forming regions of the driver MISFETs Qd 1 and Qd 2 are formed, in the active region of the p-type well 3 , under the gate electrodes 8 thereof and between the source region and the drain region thereof.
Each of the paired load MISFETs Qp 1 and Qp 2 is composed of p-type semiconductor regions 9 and 9 (the source region and the drain region) formed in the active region of the n-type well region 4 , the gate oxide film 6 formed on the surface of the active region, and the gate electrode 8 formed over the gate oxide film 6 . The gate electrode 8 of the load MISFET Qp 1 is integrated with the gate electrode 8 of the drive MISFET Qd 1 , and the gate electrode 8 of the load MISFET Qp 2 is integrated with the gate electrode 8 of the drive MISFET Qd 2 .
Channel forming regions of the load MISFETs Qp 1 and Qp 2 are formed, in the active region of the n-type well 4 , under the gate electrodes 8 thereof and between the source region and the drain region thereof.
The drive MISFET Qd 1 is arranged in the second direction between the load MISFET Qp 1 and the transfer MISFET Qt 1 , and the drive MISFET Qd 2 is arranged in the second direction between the load MISFET Qp 1 and the transfer MISFET Qt 2 . The paired drive MISFETs Qd 1 and Qd 2 and the paired load MISFETs Qp 1 and Qp 2 are so individually arranged that their gate length direction is the first direction.
On the surfaces of the individual n-type semiconductor regions 5 and 5 (the source regions and the drain regions) of the drive MISFETs Qd 1 and Qd 2 and the transfer MISFETs Qt 1 and Qt 2 , there are formed Ti (titanium) silicide (TiSi 2 ) layers for reducing the sheet resistances of the n-type semiconductor regions 5 and 5 . Likewise, on the surfaces of the individual p-type semiconductor regions 9 and 9 (the source regions and the drain regions) of the load MISFETs Qp 1 and Qp 2 , there are formed the Ti-silicide layers for reducing the sheet resistances of the p-type semiconductor regions 9 and 9 .
Side wall spacers 11 of a silicon oxide film are formed on the individual side walls of the gate electrode 7 (the word line WL) of the transfer MISFETs Qt 1 and Qt 2 and the gate electrodes 8 of the drive MISFETs Qd 1 and Qd 2 (the load MISFETs Qp 1 and Qp 2 ). A silicon oxide film (a cap insulating film) 12 is formed over the gate electrode 7 (the word line WL) and the gate electrode 8 .
Over the aforementioned six MISFETs, there is formed a silicon nitride film 13 , over which is formed one (i.e., the local wiring line L 1 ) of the paired local wiring lines L 1 and L 2 . One end portion of this local wiring line L 1 is electrically connected through a connection hole 14 , which is opened in the silicon nitride film 13 and the silicon oxide film 12 , with the gate electrode 8 which is shared by the load MISFET Qp 2 and the drive MISFET Qd 2 . Another end portion of the local wiring line L 1 is electrically connected through a connection hole 15 , which is opened in the silicon nitride film 13 , with the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 1 . Still another end portion of the local wiring line L 1 is electrically connected through a connection hole 16 , which is opened in the silicon nitride film 13 , with the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 1 . In short, the local wiring line L 1 connects the gate electrode 8 of the drive MISFET Qd 2 (the load MISFET Qp 2 ), the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 1 and the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 1 with one another. The local wiring line L 1 is formed of a TiN (titanium nitride) film, for example. The local wiring line L 1 can be made of materials other than TiN, a refractory metal such as W or a refractory metal silicide such as a W-silicide.
The local wiring line L 1 is formed over the channel forming regions of the driver MISFETs Qd 1 and Qd 2 , of the load MISFETs Qp 1 and Qp 2 , and of the transfer MISFETs Qt 1 and Qt 2 .
Over the local wiring line L 1 , there is formed the other (the local wiring line L 2 ) of the paired local wiring lines L 1 and L 2 through an interlayer insulating film 17 of a first layer which is formed of a silicon oxide insulating film of PSG (Phospho Silicate Glass). one end portion of the local wiring line L 2 is electrically connected through a connection hole 18 , which is opened in the silicon nitride film 13 and the silicon oxide film 12 , with the gate electrode 8 which is shared by the load MISFET Qp 1 and the drive MISFET Qd 1 . Another end portion of the local wiring line L 2 is electrically connected through a connection hole 19 , which is opened in the interlayer insulating film 17 and the silicon nitride film 13 , with the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 2 . Still another end portion of the local wiring line L 2 is electrically connected through a connection hole 20 , which is opened in the interlayer insulating film 17 and the silicon nitride film 13 , with the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 2 . In short, the local wiring line L 2 connects the gate electrode 8 of the drive MISFET Qd 1 (the load MISFET Qp 1 ), the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 2 and the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 2 electrically with one another. The local wiring line L 2 is composed of an Al (aluminum) film which is overlaid and underlaid with barrier metal layers of TiN, for example. In the connection holes 18 , 19 and 20 thus far described, moreover, there is buried plugs 29 which are composed of a W-film for ensuring the reliability of electrical connection between the local wiring line L 2 and the gate electrode 8 , and electrical connection between the n-type semiconductor region and the p-type semiconductor region 9 .
The local wiring line L 2 is formed over the channel forming regions of the driver MISFETs Qd 1 and Qd 2 , of the local MISFETs Qp 1 and Qp 2 , and of the transfer MISFETs Qt 1 and Qt 2 .
Over the local wiring line L 2 , there are formed, through an interlayer insulating film 21 of a second layer made of silicon oxide, a power supply voltage line 22 and a reference voltage line 23 . The power supply voltage line 22 is electrically connected through a connection hole 24 , which is opened in the interlayer insulating films 21 and 17 and the silicon nitride film 13 , with the individual p-type semiconductor regions 9 (the source regions) of the load MISFETs Qp 1 and Qp 2 to supply these p-type semiconductor regions 9 with the power supply voltage (Vcc). The reference voltage line 23 is electrically connected through a connection hole 25 , which is opened in the interlayer insulating films 21 and 17 and the silicon nitride film 13 , with the individual n-type semiconductor regions (the source regions) of the drive MISFETs Qd 1 and Qd 2 to supply the n-type semiconductor regions with the reference voltage (Vss). The power supply voltage line 22 and the reference voltage line 23 are composed of an Al film which is overlaid and underlaid with barrier metal layers, for example. In the connection holes 24 and 25 , there are buried plugs 37 which are composed of a W-film, for example, for ensuring the reliability of electrical connection between the power supply voltage line 22 and the p-type semiconductor region 9 , and electrical connection between the reference voltage line 23 and the n-type semiconductor region 5 .
Over the power supply voltage line 22 and the reference voltage line 23 , there are formed, through an interlayer insulating film 26 of a third layer made of silicon oxide, the paired complementary data lines (the data line DL and the data line DL). One (the data line DL) of these complementary data lines is electrically connected through a connection hole 27 , which is opened in the interlayer insulating films 26 , 21 and 17 and the silicon nitride film 13 , with the n-type semiconductor region 5 (the other of the source region and the drain region) of the transfer MISFET Qt 1 . The other (the data line DL) of the complementary data lines is electrically connected through the connection hole 27 , which is opened in the interlayer insulating films 26 , 21 and 17 and the silicon nitride film 13 , with the n-type semiconductor region 5 (the other of the source region and the drain region) of the transfer MISFET Qt 2 . The data line DL and the data line DL are composed of Al films which are overlaid and underlaid with barrier metal layers of TiN. In the connection holes 27 and 27 , although not shown, there are buried plugs which are composed of W-films for ensuring the reliability of electrical connection between the data lines (DL and DL) and the n-type semiconductor region 5 .
Thus, in the SRAM of the present embodiment, the paired local wiring lines L 1 and L 2 cross-connecting the input/output terminals of the flip-flop circuit of the memory cell are formed in the different conductive layers. Thanks to this construction, the space, which is required for arranging the two local wiring lines transversely when the paired local wiring lines are formed in the same conductive layer, is not required, so that the local wiring lines L 1 and L 2 can be arranged partially in an overlapping manner, thereby reducing the area occupied by the memory cell.
A method for manufacturing the memory cell of the SRAM of the present embodiment will be described with reference to FIGS. 6 to 32 . Of these showing the memory cell manufacturing method, sections (a) are taken along line A-A′ of the top plan views, and sections (b) are taken along line B-B′ of the top plan views. These individual top plan views show only the conductive layers and the connection holes but do not show the insulating films.
First of all, a groove 30 is formed in the periphery (element isolating region) of an active region AR of the major face of the semiconductor substrate 1 made of p-type single crystal silicon, as shown in FIGS. 6 and 7 ( a ) and ( b ). This groove 30 is formed by depositing a silicon oxide film 31 and a silicon nitride film 32 consecutively over the semiconductor substrate 1 and then by dry-etching the silicon nitride 32 , the silicon oxide film 31 and the semiconductor substrate 1 consecutively by using a photoresist as the mask.
Next, a silicon oxide film 36 is buried in the groove 30 to form the element isolating groove 2 , as shown in FIGS. 8 ( a ) and 8 ( b ). The element isolating groove 2 is formed by depositing the silicon oxide film 36 thickly over the semiconductor substrate 1 , including the inside of the groove 30 , by a CVD (Chemical Vapor Deposition) method and then by etching back (chemico-mechanical polishing (CMP)) the silicon oxide film 36 by using the silicon nitride film 32 as an etching stopper.
Next, the silicon nitride film 32 and the silicon oxide film 31 , left on the surface of the active region AR, are etched away. After this, as shown in FIGS. 9 and 10 ( a ) and 10 ( b ), the semiconductor substrate 1 of the active region AR where the drive MISFETs Qd 1 and Qd 2 and the transfer MISFETs Qt 1 and Qt 2 are formed is doped with ions of p-type impurity (boron) to form the p-type well 3 , and the semiconductor substrate 1 of the active region AR where the load MISFETs Qp 1 and Qp 2 are formed is doped with ions of an n-type impurity (phosphorous or arsenic) to form the n-type well 4 . After this, the individual surfaces of the p-type well 3 and the n-type well 4 are thermally oxidixed to form gate oxide film 6 .
Next, an n-type polycrystalline silicon film 33 , a W-silicide film 34 and the silicon oxide film 12 are consecutively deposited over the semiconductor substrate 1 by a CVD method, as shown in FIGS. 11 ( a ) and ( b ). After this, the silicon oxide film 12 , the W-silicide film 34 and the n-type polycrystalline silicon film 33 are patterned by using a photoresist as the mask, as shown in FIGS. 12 and 13 ( a ) and 13 ( b ), to form the gate electrode 7 (the word line WL) of the transfer MISFETs Qt 1 and Qt 2 and the gate electrodes 8 and 8 of the drive MISFETs Qd 1 and Qd 2 (the load MISFITs Qp 1 and Qp 2 ).
Next, as shown in FIGS. 14 and 15 ( a ) and 15 ( b ), the p-type well 3 is doped with ions of n-type impurity (phosphorous or arsenic) to form the n-type semiconductor regions 5 and 5 (the source region and the drain region) of the transfer MISFETs Qt 1 and Qt 2 , and the drive MISFETs Qd 1 and Qd 2 , and the n-type well 4 is doped with the ions of p-type impurity (boron) to form the p-type semiconductor regions 9 and 9 (the source region and the drain region) of the load MISFETs Qp 1 and Qp 2 . After this, the silicon oxide film, deposited over the semiconductor substrate 1 by a CVD method, is anisotropically etched to form the side wall spacers 11 on the individual side walls of the gate electrode 7 (the word line WL) of the transfer MISFETs Qt 1 and Qt 2 and the gate electrodes 8 and 8 of the drive MISFETs Qd 1 and Qd 2 .
Next, there are etched the gate oxide film covering the surfaces of the individual n-type semiconductor regions 5 and 5 (the source region and the drain region) of the drive MISFETs Qd 1 and Qd 2 and the transfer MISFETs Qt 1 and Qt 2 , and the gate oxide film 6 covering the surfaces of the p-type semiconductor regions 9 and 9 (the source region and the drain region) of the load MISFETs Qp 1 and Qp 2 . After this, as shown in FIG. 16, a Ti-film 35 is deposited over the semiconductor substrate 1 by sputtering.
Next the semiconductor substrate 1 is annealed (thermally treated) to cause a reaction between the Ti-film 35 and the semiconductor substrate 1 (the n-type semiconductor region 5 and the p-type semiconductor region 9 ). After this, the unreacted Ti-film 35 is etched to form the Ti-silicide layer 10 on the surfaces of the p-type semiconductor region 5 and the p-type semiconductor region 9 , as shown in FIGS. 17 and 18 ( a ) and 18 ( b ). After this, the semiconductor substrate 1 is annealed, if necessary, to reduce the resistance of the Ti-silicide layer 10 . Instead of forming the Ti-silicide layer 10 , a Co (cobalt) film may be formed over the semiconductor substrate 1 by sputtering to cause a reaction between the semiconductor substrate 1 (the n-type semiconductor region 5 and the p-type semiconductor region 9 ) and the Co film, thereby to form a Co-silicide layer.
Next, the silicon nitride film 13 , as thin as about 30 nm, is deposited over the semiconductor substrate 1 , as shown in FIGS. 19 and 20 ( a ) and ( b ). After this, the connection hole 14 is opened in the silicon nitride film 13 and the silicon oxide film 12 over the gate electrodes 8 of the drive MISFET Qd 2 (or the load MISFET Qp 2 ) by a dry-etching method using a photoresist as the mask. Simultaneously with this, the silicon nitride film 13 over the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 1 is etched off to form the connection hole 15 , and the silicon nitride film 13 over the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 1 is etched to form the connection hole 16 . Next, the local wiring line L 1 is formed over the silicon nitride film 13 , as shown in FIGS. 21 and 22 ( a ) and ( b ). The local wiring line L 1 is formed by patterning the TiN film, having a thickness of about 100 nm and deposited over the semiconductor substrate 1 by a sputtering method or a CVD method, by a dry-etching method using a photoresist as the mask. This local wiring line L 1 is connected through the connection hole 14 with the common gate electrode 8 of the load MISFET Qp 2 and the drive MISFET Qd 2 , through the connection hole 15 with the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 1 , and through the connection hole 16 with the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 1 .
Next, the interlayer insulating film 17 of PSG is deposited over the local wiring line L 1 by the CVD method, as shown in FIGS. 23 and 24 ( a ) and ( b ). After this, the interlayer insulating film 17 , the silicon nitride film 13 and the silicon oxide film 12 lying over the gate electrode 8 of the drive MISFET Qd 1 (the load MISFET Qp 1 ) are opened to form the connection hole 18 by a dry-etching technique using a photoresist as the mask. Simultaneously with this, the interlayer insulating film 17 and the silicon nitride film 13 over the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 2 are etched to form the connection hole 19 , and the interlayer insulating film 17 and the silicon nitride film 13 over the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 2 are etched to form the connection hole 20 .
Next, W-films are buried in the connection holes 18 , 19 and 20 to form the plugs 29 , as shown in FIGS. 25 and 26 ( a ) and ( b ). After this, the local wiring line L 2 is formed over the interlayer insulating film 17 . The burying operation of the W-film is carried out by etching back the W-film which is deposited over the interlayer insulating film 17 by a sputtering method. The local wiring line L 2 is formed by depositing the TiN film, the Al film and the TiN film consecutively over the interlayer insulating film 17 by a sputtering method and then by patterning those films by a dry-etching method using a photoresist as the mask. The local wiring line L 2 is connected through the connection hole 18 with the common gate 8 of the load MISFET Qp 1 and the drive MISFET Qd 1 , through the connection hole 19 with the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 2 , and through the connection hole 20 with the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 2 .
Next, the interlayer insulating film 21 of silicon oxide is deposited over the local wiring line L 2 by a CVD method, as shown in FIGS. 27, 28 and 29 . After this, the interlayer insulating films 21 and 17 and the silicon nitride film 13 over the individual p-type semiconductor regions 9 and 9 (the source regions) of the load MISFETs Qp 1 and Qp 2 are opened to form the connection holes 24 and 24 by the dry-etching method, using a photoresist as the mask. Simultaneously with this, the interlayer insulating films 21 and 17 and the silicon nitride film 13 over the individual n-type semiconductor regions 5 and 5 (the source regions) of the drive MISFETs Qd 1 and Qd 2 are opened to form the connection holes 25 and 25 .
Next, W-films are buried in the connection holes 24 and 25 to form the plug 37 . After this, as shown in FIGS. 30, 31 and 32 , the power supply voltage line 22 and the reference voltage line 23 are formed over the interlayer insulating film 21 . These power supply and reference voltage lines 22 and 23 are formed by depositing a TiN film, an Al film and a TiN film consecutively over the interlayer insulating film 21 by a sputtering method, and then by patterning those films by a dry-etching method using a photoresist as the mask. The power supply voltage line 22 is connected through the connection holes 24 and 24 with the individual p-type semiconductor regions 9 and 9 (the source regions) of the load MISFETs Qp 1 and Qp 2 , and the reference voltage line 23 is connected through the connection holes 25 and 25 with the individual n-type semiconductor regions 5 and 5 (the source regions) of the drive MISFETS Qd 1 and Qd 2 .
After this, the interlayer insulating film 26 of silicon oxide is deposited over the power supply voltage line 22 and the reference voltage line 23 by a CVD method. After this, the interlayer insulating films 26 , 21 and 17 and the silicon nitride film 13 over the individual n-type semiconductor regions 5 and 5 (the drain regions) of the transfer MISFETs Qt 1 and Qt 2 are opened to form the connection holes 27 and 27 by a dry-etching method using a photoresist as the mask. Subsequently, W-films are buried in the connection holes 27 and 27 to form plugs, and the data lines DL and DL are then formed over the interlayer insulating film 26 . These data lines DL and DL are formed by depositing a TiN film, an Al film and a TiN film consecutively over the interlayer insulating film 26 by a sputtering method, and then by patterning those films by a dry-etching method using a photoresist as the mask. The data line DL is connected through one of the connection holes 27 and 27 with the n-type semiconductor region 5 (the drain region) of the transfer MISFET Qt 1 , and the data line DL is connected through the other of the connection holes 27 and 27 with the n-type semiconductor region 5 (the drain region) of the transfer MISFET Qt 2 . The memory cell, as shown in FIGS. 1 to 4 , is thus completed by the steps described.
Embodiment 2
FIG. 33 is a top plan view showing a memory cell of an SRAM of the present embodiment; FIG. 34 is a section taken along line A-A′ of FIG. 33; FIG. 35 is a section taken along line B-B′ of FIG. 33; and FIG. 36 is an equivalent circuit diagram showing the memory cell of the SRAM of the present embodiment.
In the SRAM of the present embodiment, as shown, the paired local wiring lines L 1 and L 2 cross-connecting the input/output terminals of the flip-flop circuit of the memory cell are formed in different conductive layers, as in the SRAM of the foregoing embodiment 1. In the SRAM of the present embodiment, moreover, the upper local wiring line L 2 overlaps with the lower local wiring line L 1 over a wide area, and a capacitor element C is composed of the local wiring lines L 1 and L 2 and a thin insulating film (a silicon nitride film 42 ) interposed between the wiring lines. Specifically, the upper local wiring line L 2 is one electrode of the capacitor element C, the lower local wiring line L 1 is the other electrode, and the insulating film (the silicon nitride film 42 ) is its dielectric film.
A method for manufacturing the memory cell of the SRAM of the present embodiment will be described with reference to FIGS. 37, 38 ( a ) and ( b ), 39 , 40 ( a ) and ( b ), 41 , 42 ( a ) and ( b ), 43 , 44 ( a ) and ( b ) 45 , 46 ( a ) and ( b ), 47 and 48 ( a ) and ( b ). Of the individual Figures showing the memory cell manufacturing method, sections (a) are taken along line A-A′ of the top plan views, and sections (b) are taken along line B-B′ of the top plan views. Moreover, the individual top plan views show only the conductive layers and the connection holes but do not show the insulating films.
First of all, in accordance with the manufacturing method of the foregoing embodiment 1, as shown in FIGS. 6 et seq., up to and including FIGS. 18 ( a ) and ( b ), an element isolating groove 2 , a retype well 3 , an n-type well 4 and a gate oxide film 6 are formed over a major face of the semiconductor substrate 1 . After this, drive MISFETs Qd 1 and Qd 2 and transfer MISFETs Qt 1 and Qt 2 are formed in a p-type well 3 , and load MISFETs Qp 1 and Qp 2 are formed in an n-type well 4 . Moreover, a Ti-silicide layer 10 is formed so as to reduce the sheet resistance over the surfaces of n-type semiconductor regions 5 and 5 (the source region and the drain region) of the transfer MISFETs Qt 1 and Qt 2 and the drive MISFETs Qd 1 and Qd 2 and over the surfaces of p-type semiconductor regions 9 and 9 (the source region and the drain region) of the load MISFETs Qp 1 and Qp 2 .
Next, as shown in FIGS. 37 and 38 ( a ) and ( b ), a silicon nitride film 13 , as thick as about 50 nm, is deposited over the semiconductor substrate 1 . After this, the silicon nitride film 13 and a silicon oxide film 12 over a gate electrode 8 of the drive MISFET Qd 2 (or the load MISFET Qp 2 ) are opened to form a connection hole 14 by a dry-etching method using a photoresist as the mask. Simultaneously with this, the silicon nitride film 13 over the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 1 is etched to form a connection hole 40 , and the silicon nitride film 13 over the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 1 is etched to form a connection hole 41 .
Next, as shown in FIGS. 39 and 40 ( a ) and ( b ), a local wiring line L 1 is formed over the silicon nitride film 13 . This local wiring line L 1 is formed by patterning a TiN film, having a thickness of about 100 nm and deposited over the silicon nitride film 13 by a sputtering method or a CVD method, by a dry-etching method using a photoresist as the mask. The local wiring line L 1 is given an area wide enough to cover the six MISFETs constituting the memory cell. Specifically, the local wiring line L 1 is so arranged as to cover the gate electrode 8 of the drive MISFET Qd 1 (the load MISFET Qp 1 ), the gate electrode 8 of the drive MISFET Qd 2 (the load MISFET Qp 2 ), the gate electrode 7 (the word line W 1 ) of the transfer MISFETs Qt 1 and Qt 2 , the common n-type semiconductor region (one of the source region and the drain region) of the transfer MISFETs Qt 1 and Qt 2 and the drive MISFETs Qd 1 and Qd 2 , and the p-type semiconductor region 9 (the drain region) of the load MISFETs Qp 1 and Qp 2 .
The local wiring line L 1 is connected through the connection hole 14 with the gate electrode 8 of the drive MISFET Qd 2 (the load MISFET Qp 2 ), through the connection hole 40 with the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 1 , and through the connection hole 41 with the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 1 .
Next, as shown in FIGS. 41 and 42 ( a ) and ( b ), a silicon nitride film 42 having a thickness of about 30 nm is deposited over the local wiring line L 1 . After this, the silicon nitride films 17 and 13 and the silicon oxide film 12 over the gate electrode 8 of the drive MISFET Qd 1 (the load MISFET Qp 1 ) are opened to form a connection hole 18 by a dry-etching method using a photoresist as the mask. Simultaneously with this, the silicon nitride films 17 and 13 over the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 2 are etched to form the connection hole 19 , and the silicon nitride films 17 and 13 over the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 2 are etched to form a connection hole 20 .
Next, as shown in FIGS. 43 and 44 ( a ) and ( b ), a local wiring line L 2 is formed over the silicon nitride film 42 . This local wiring line L 2 is formed by patterning the TiN film, which is so deposited as to have a thickness of about 100 nm by a sputtering method or a CVD method, by a dry-etching method using a photoresist as the mask. The local wiring line L 2 can be made of not only TiN but also a refractory metal such as W or a refractory metal silicide such as W-silicide. The local wiring line L 2 is connected through the connection hole 18 with the gate electrode 8 of the drive MISFET Qd 1 (the load MISFET Qp 1 ) through the connection hole 19 with the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 2 , and through the connection hole 20 with the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 1 .
The local wiring line L 2 is so formed over the lower local wiring line L 1 as to have an area wide enough to cover the six MISFETs constituting the memory cell and is substantially completely superposed on the local wiring line L 1 in the region excepting the open regions of the connection holes 18 , 19 and 20 and their registration allowance region. As a result, the capacitor element C can be composed of both the local wiring lines L 1 and L 2 and the silicon nitride film 42 (the dielectric film) interposed therebetween and made thinner than the local wiring lines L 1 and L 2 , and can be given a large capacitance, so that the amount of stored charge of the storage node can be increased to improve the alpha particle soft error resistance of the memory cell. If, moreover, the thin insulating film, interposed between the local wiring lines L 1 and L 2 , is made of a highly dielectric material such as tantalum pentoxide (Ta 2 O 5 ), the amount of stored charge of the storage node can be further increased.
Next, as shown in FIGS. 45 and 46 ( a ) and ( b ), an interlayer insulating film 21 made of silicon oxide is deposited over the local wiring line L 2 by a CVD method. After this, the interlayer insulating film 21 and the silicon nitride films 17 and 13 over the individual p-type semiconductor regions 9 and 9 (the source regions) of the load MISFETs Qp 1 and Qp 2 are opened to form connection holes 24 and 24 by a dry-etching method using a photoresist as the mask. Simultaneously with this, the interlayer insulating film 21 and the silicon nitride films 17 and 13 over the individual n-type semiconductor regions 5 and 5 (the source regions) of the drive MISFETs Qd 1 and Qd 2 are opened to form connection holes 25 and 25 .
Next, as shown in FIGS. 47 and 48 ( a ) and ( b ), W-films are buried in the connection holes 24 and 25 to form plugs 29 , and power supply voltage line 22 and reference voltage line 23 are then formed over the interlayer insulating film 21 . These power supply and reference voltage lines 22 and 23 are formed by depositing a TiN film, an Al file and a TiN film consecutively over the interlayer insulating film 21 by a sputtering method, and then by patterning those films.
After this, an interlayer insulating film 26 of silicon oxide is deposited over the power supply voltage line 22 and the reference voltage line 23 by a CVD method. After this, the interlayer insulating films 26 and 21 and the silicon nitride films 17 and 13 over the individual n-type semiconductor regions 5 and 5 (the drain regions) of the transfer MISFETs Qt 2 and Qt 2 are opened to form connection holes 27 and 27 by a dry-etching method using a photoresist as the mask. Subsequently, W-films are buried in the connection holes 27 and 27 to form plugs, and the data lines DL and DL are then formed over the interlayer insulating film 26 . These data lines DL and DL are formed by depositing a TiN film, an Al film and a TiN film consecutively over the interlayer insulating film 26 by a sputtering method and then by patterning those films. The memory cell, as shown in FIGS. 33 to 35 , is thus completed by the steps described.
Embodiment 3
In the SRAM of the present embodiment, the paired local wiring lines L 1 and L 2 cross-connecting the input/output terminals of the flip-flop circuit of the memory cell are formed in the same conductive layer. The method for manufacturing the memory cell of this SRAM will be described with reference to FIGS. 49 to 64 . Of the individual Figures showing the memory cell manufacturing method, sections are taken along line C-C′ of the top plan views. Moreover, the individual top plan views show only the conductive layers and the connection holes but do not show the insulating films.
First of all, as shown in FIGS. 49 and 50, a p-type well 3 and a n-type well 4 are formed over the principal face of a semiconductor substrate 1 , and an element isolating field oxide film 28 and a gate oxide film 6 of a MISFET are then formed over those surfaces. After this, drive MISFETs Qd 1 and Qd 2 and transfer MISFETs Qt 1 and Qt 2 are formed in the p-type well 3 , and load MISFETs Qp 1 and Qp 2 are formed in the n-type well 4 . A gate electrode 7 (the word line WL) of the transfer MISFETs Qt 1 and Qt 2 and gate electrodes 8 and 8 of the drive MISFETs Qd 1 and Qd 2 (the load MISFETs Qp 1 and Qp 2 ) are formed of a polycrystalline silicon film having a thickness of about 300 nm. Side wall spacers on the individual side walls of the gate electrode 7 (the word line WL) and the gate electrode 8 are formed by etching a silicon oxide film.
Next, as shown in FIGS. 51 and 52, in order to reduce the sheet resistance, a Ti-silicide layer 10 is formed on the individual surfaces of the gate electrode 7 (the word line WL) of the transfer MISFETs Qt 1 and Qt 2 , the gate electrodes 8 and 8 of the drive MISFETs Qd 1 and Qd 2 (the load MISFETs Qp 1 and Qp 2 ), individual n-type semiconductor regions 5 and 5 (the source region and the drain region) of the transfer MISFETs Qt 1 and Qt 2 and the drive MISFETs Qd 1 and Qt 2 , and individual p-type semiconductor regions 9 and 9 of the load MISFETs Qp 1 and Qp 2 .
In order to form the Ti-silicide layer 10 , a silicon oxide film 12 covering the individual surfaces of the gate electrode 7 (the word line WL) and the gate electrode 8 , a gate oxide film 6 covering the surfaces of the individual n-type semiconductor regions 5 and 5 (the source region and the drain region) of the drive MISFETs Qd 1 and Qd 2 and the transfer MISFETs Qt 1 and Qt 2 , and a gate oxide film 6 covering the surfaces of the individual p-type semiconductor regions 9 and 9 (the source region and the drain region) of the load MISFETs Qp 1 and Qp 2 are etched. After this, a Ti-film is deposited over the semiconductor substrate 1 by sputtering. Next, the semiconductor substrate 1 is annealed to cause reactions individually between the Ti-film and the semiconductor substrate 1 (the n-type semiconductor region 5 and the p-type semiconductor region 9 ) and between the Ti-film and the polycrystalline silicon film (the gate electrodes 7 and 8 ), and the unreacted Ti-film is then etched away.
Next, as shown in FIGS. 53 and 54, a silicon nitride film 13 , as thin as about 30 nm, is deposited over the semiconductor substrate 1 by a CVD method. After this, the silicon nitride film 13 is dry-etched by using a photoresist as the mask to form a connection hole 43 , which reaches the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 1 and the gate electrode 8 of the drive MISFET Qd 2 (the load MISFET Qp 2 ), and a connection hole 44 which reaches the p-type semiconductor region 9 (the drain region) of the load MISFET QP 2 and the gate electrode 8 of the drive MISFET Qd 1 (the load MISFET Qp 1 ). Simultaneously with this, a connection hole 45 is formed over the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 2 , and a connection hole 46 is formed over the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 1 . At this time, the surface of a field oxide film 28 is covered with the silicon nitride film 13 , so that it is not removed by the dry-etching treatment.
Next, as shown in FIGS. 55 and 56, the paired local wiring lines L 1 and L 2 , composed of a TiN film, are formed over the silicon nitride film 13 . For forming these local wiring lines L 1 and L 2 , a TiN film having a thickness of about 50 to 100 nm is deposited over the silicon nitride film 13 by a sputtering method or a CVD method. Next, a silicon nitride film 47 having a thickness of about 100 nm is deposited over the TiN film by a CVD method. After this, the silicon nitride film 47 and the TiN film are patterned by a dry-etching method using a photoresist as the mask. The local wiring lines L 1 and L 2 can be made of not only TiN but also a refractory metal such as W or a refractory metal silicide such as a W-silicide.
The local wiring line L 1 is so arranged as to overlap with the gate electrode 8 of the drive MISFET Qd 1 (the load MISFET Qp 1 ) and the gate electrode 7 (the word line WL) of the transfer MISFETs Qt 1 and Qt 2 , and the local wiring line L 2 is so arranged as to overlap with the gate electrode 8 of the drive MISFIT Qd 2 (the load MISFET Qp 2 ) and the gate electrode 7 (the word line WL) of the transfer MISFETs Qt 1 and Qt 2 . Thanks to this construction, a capacitor element C′ is composed of the local wiring line L 1 , the gate electrode 8 and the thin silicon nitride film 13 interposed therebetween, and a capacitor element C′ is formed of the local wiring line L 2 , the gate electrode 8 and the silicon nitride film 13 interposed therebetween, so that the charge storage capacity of the storage node can be increased to improve the alpha particle soft error resistance of the memory cell. These capacitor elements C′ act effectively similarly to those of the capacitor element C of the foregoing embodiment 2 (of FIG. 36 ).
The local wiring line L 1 is connected through the connection hole 43 with the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 1 and the gate electrode 8 of the drive MISFET Qd 2 (the load MISFET Qp 2 ), and through the connection hole 46 with the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 1 . In other words, the gate electrode 8 of the drive MISFET Qd 2 (the load MISFET Qp 2 ), the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 1 , and the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 1 are connected with one another through the local wiring line L 1 .
The local wiring line L 2 is connected through the connection hole 44 with the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 2 and the gate electrode 8 of the drive MISFET Qd 1 (the load MISFET Qp 1 ), and through the connection hole 45 with the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 2 . In other words, the gate electrode 8 of the drive MISFET Qd 1 (the load MISFET Qp 1 ), the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 2 , and the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 2 are connected with one another through the local wiring line L 2 .
Next, as shown in FIG. 57, a silicon nitride film 53 having a thickness of about 200 nm is deposited over the silicon nitride film 47 by a CVD method. After this, as shown in FIG. 58, this silicon nitride film 53 is anisotropically etched by a RIE (Reactive Ion Etching) method to form side wall spacers 48 on the individual side walls of the gate electrode 7 (the word line WL), the gate electrode 8 and the local wiring lines L 1 and L 2 .
Next, as shown in FIGS. 59 and 60, an interlayer insulating film 49 of a silicon oxide, such as PSG, of an etching rate different from that of the silicon nitride films 47 and 53 (the side wall spacer 48 ) is deposited by a CVD method over the silicon nitride film 47 and the side wall spacers 48 . The etching rate of the material of insulating film 49 is greater than that of the silicon nitride of films 47 and 53 (side wall spacer 48 ), for example. After this, the interlayer insulating film 49 over the individual p-type semiconductor regions 9 and 9 (the source regions) of the load MISFETs Qp 1 and Qp 2 are opened to form connection holes 50 and 50 by a dry-etching method using a photoresist as the mask. Simultaneously with this, the interlayer insulating film 49 over the individual n-type semiconductor regions and (the source regions) of the drive MISFETs Qd 1 and Qd 2 is opened to form connection holes 51 and 51 , and the interlayer insulating film 49 over the individual n-type semiconductor regions 5 and 5 (the other of the source region and the drain region) of the transfer MISFETs Qt 1 and Qt 2 is opened to form connection holes 52 and 52 .
At the aforementioned step of forming the connection holes 50 , 51 and 52 by etching the interlayer insulating film 49 of PSG, due to the silicon nitride film 47 formed over the local wiring lines L 1 and L 2 , and the side wall spacers of silicon nitride formed on the individual side walls of the gate electrode 7 (the word line WL), the gate electrode 8 and the local wiring lines L 1 and L 2 are hardly etched because their etching rates are different from (e.g., much less than) that of the material of the interlayer insulating film 49 .
The connection holes 50 , 51 and 52 and the local wiring lines L 1 and L 2 can be positionally displaced due to the misregistration of the photoresist mask used for forming the connection holes 50 , 51 and 52 by etching the interlayer insulating film 49 and the photoresist mask used for forming the local wiring lines L 1 and L 2 by etching the TiN film. However, in the present embodiment, even with a partial overlap between any of the connection holes 50 , 51 and 52 and the local wiring line L 1 or the local wiring line L 2 , neither the local wiring line L 1 nor the local wiring line L 2 is exposed from the side wall of any of the connection holes 50 , 51 and 52 when the interlayer insulating film 49 is etched, thereby preventing short circuit between the conductive film to be deposited at a later step in the connection holes 50 , 51 and 52 and the local wiring line L 1 or the local wiring line L 2 .
The connection holes 50 , 51 and 52 , the gate electrode 7 (the word line WL) and the gate electrode 8 can be relatively displaced due to misregistration between the photoresist mask to be used for forming the connection holes 50 , 51 and 52 by etching the interlayer insulating film 49 and the photoresist mask to be used for forming the gate electrode (the word line WL) and the gate electrode 8 by etching the polycrystalline silicon film. However, in the present embodiment, even with a partial overlap between any of the connection holes 50 , 51 and 52 and the gate electrode 7 (the word line WL) or the gate electrode 8 , the gate electrode 8 is not exposed from the side wall of the connection hole 50 or 51 , and the gate electrode 7 (the word line WL) is not exposed from the side wall of the connection hole 52 when the interlayer insulating film 49 is etched, thereby preventing short circuit between the conductive film to be deposited at a later step in the connection holes 50 , 51 and 52 and the gate electrode 7 (the word line WL) or the gate electrode 8 .
In short, according to the manufacturing method of the present embodiment, when the connection holes 50 , 51 and 52 are laid out, it is unnecessary to take into consideration the registration allowance between the connection holes 50 , 51 and 52 and the local wiring lines L 1 and L 2 and the registration allowance between the connection holes 50 , 51 and 52 and the gate electrode 7 (the word line WL) and the gate electrode 8 . As a result, the connection holes 50 , 51 and 52 can be laid out so as to be closer to the local wiring lines L 1 and L 2 , the gate electrode 7 (the word line WL) and the gate electrode 8 by a distance corresponding to those registration allowances. Therefore, the area occupied by the memory cell can be reduced in both the first direction and the second direction perpendicular to the first direction.
In order that the side wall spacer 48 may function as the etching stopper when the interlayer insulating film 49 is etched, the thickness of the silicon nitride film 53 constituting the side wall spacer 48 has to be larger than the registration allowance of the photoresist mask. The thickness of the silicon nitride film 53 is set to at least about 200 nm when the sum of (1) the registration allowance between the connection holes 50 , 51 and 52 and the local wiring lines L 1 and L 2 , and (2) the registration allowance between the connection holes 50 , 51 and 52 and the gate electrode 7 (the word line WL) and the gate electrode 8 , is about 200 nm, for example.
Next, the thin silicon nitride film 13 at the bottoms of the connection holes 50 , 51 and 52 is etched. After this, as shown in FIGS. 61 and 62, power supply voltage line 22 , reference voltage line 23 and an intermediate wiring line 54 are formed over the interlayer insulating film 49 . The power supply voltage line, reference voltage line and intermediate wiring line 22 , 23 and 54 are formed by depositing a W-film, an Al film and a W-film consecutively over the interlayer insulating film 49 by a sputtering method, and then by patterning those films. Plugs of W-film may be formed, if necessary, in the connection holes 50 , 51 and 52 .
Next, as shown in FIGS. 63 and 64, an interlayer insulating film 26 of silicon oxide is deposited by a CVD method over the power supply voltage line 22 , the reference voltage line 23 and the intermediate wiring line 54 , and the interlayer insulating film 26 over the intermediate wiring line 54 is opened to form a connection hole 55 by a dry-etching method using a photoresist as the mask. After this, the data lines DL and DL are formed over the interlayer insulating film 26 . These data lines DL and DL are formed by depositing a TiN film, an Al film and a TiN film consecutively over the interlayer insulating film 26 by sputtering and then by patterning those films.
Embodiment 4
In the SRAM of the present embodiment, the paired local wiring lines L 1 and L 2 are formed in the same conductive layer as in the SRAM of the foregoing embodiment 3. A method for manufacturing the memory cell of this SRAM will be described with reference to FIGS. 65 to 82 .
First of all, as shown in FIGS. 65 and 66, a p-type well 3 and an n-type well 4 are formed in the major face of a semiconductor substrate 1 , and a field oxide film 28 for isolating the elements and a gate oxide film 6 of an MISFET are then formed on those surfaces. After this, drive MISFETs Qd 1 and Qd 2 and transfer MISFETs Qt 1 and Qt 2 are formed in the p-type well 3 , and load MISFETs Qp 1 and Qp 2 are formed in the n-type well 4 . A gate electrode 7 (the word line WL) of the transfer MISFETs Qt 1 and Qt 2 and gate electrodes 8 and 8 of the drive MISFETs Qd 1 and Qd 2 (the load MISFETs Qp 1 and Qp 2 ) are composed of a polycrystalline silicon film. The insulating films (the cap insulating films) covering the gate electrode 7 (the word line WL) and the gate electrode 8 individually are composed of a silicon nitride film 56 . This silicon nitride film 56 is deposited thicker (the thickness is more than about 300 nm) than a later described silicon nitride film 13 . Side wall spacers 11 on the individual side walls of the gate electrode 7 (the word line WL) and gate electrode 8 are formed by etching a silicon oxide film anisotropically.
Next, as shown in FIGS. 67 and 68, the silicon nitride film 56 over the gate electrode 8 of the drive MISFET Qd 1 (the load MISFET Qp 1 ) is etched to form a connection hole 57 , and the silicon nitride film 56 over the gate electrode 8 of the drive MISFET Qd 2 (the load MISFET Qp 2 ) is etched to form a connection hole 58 . The connection hole 57 is formed in the region to be connected with the local wiring line L 2 at a later step, and the connection hole 58 is formed in the region to be connected with the local wiring line L 1 at a later step.
Next, as shown in FIGS. 69 and 70, a Ti-silicide layer is formed on the individual surfaces of the gate electrode 8 of the drive MISFET Qd 1 (the load MISFET Qp 1 ), exposed at the bottom of the connection hole 57 , the gate electrode 8 of the drive MISFET Qd 2 (the load MISFET Qp 2 ), exposed at the bottom of the connection hole 58 , n-type semiconductor regions 5 and 5 (the source region and the drain region) of the transfer MISFETs Qt 1 and Qt 2 , the n-type semiconductor regions 5 and 5 (the source region and the drain region) of the drive MISFETs Qd 1 and Qd 2 , and p-type semiconductor regions 9 and 9 (the source region and the drain region) of the load MISFETs Qp 1 and, Qp 2 .
In order to form the Ti-silicide layer 10 , the gate oxide film 6 , covering the surfaces of the individual n-type semiconductor regions 5 and 5 (the source region and the drain region) of the drive MISFETs Qd 1 and Qd 2 and transfer MISFETs Qt 1 and Qt 2 , and the gate oxide film 6 , covering the surface of the individual p-type semiconductor regions 5 and 5 (the source region and the drain region) of the load MISFETs Qp 1 and Qp 2 , are etched. After this, a Ti-film is deposited over the semiconductor substrate 1 by sputtering. Next, the semiconductor substrate 1 is annealed to cause reactions between the Ti-film and the semiconductor substrate 1 (the n-type semiconductor region 5 and the p-type semiconductor region 9 ) and between the Ti-film and the polycrystalline silicon film (the gate electrode 8 exposed at the bottoms of the connection holes 57 and 58 ), and the unreacted Ti-film is etched off.
Next, as shown in FIGS. 71 and 72, the silicon nitride film 13 , as thin as about 30 nm, is deposited over the semiconductor substrate 1 by a CVD method. After this, the silicon nitride film 13 is dry-etched by using a photoresist as the mask to form a connection hole 43 , which reaches the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 1 and the gate electrode 8 of the drive MISFET Qd 2 (the load MISFET Qp 2 ), and a connection hole 44 which reaches the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 2 and the gate electrode 8 of the drive MISFET Qd 1 (the load MISFET Qp 1 ). Simultaneously with this, a connection hole 45 is formed over the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 2 , and a connection hole 46 is formed over the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 1 .
Since a connection hole 58 is formed in advance over the gate electrode 8 of the drive MISFET Qd 1 (the load MISFET Qp 1 ), the connection hole 43 partially overlaps the connection hole 58 over the gate electrode 8 . Likewise, since a connection hole 57 is formed in advance over the gate electrode 8 of the drive MISFET Qd 2 (the load MISFET Qp 2 ), the connection hole 44 partially overlaps the connection hole 57 over the gate electrode 8 .
In short, by the manufacturing method of the present embodiment, when the connection holes 43 , 44 , 45 and 46 are laid out, it is unnecessary to consider the registration allowance between those connection holes 43 to 46 and the gate electrode 8 and the registration allowance between the connection holes 43 to 46 and the connection holes 57 and 58 . As a result, the connection holes 43 to 46 can be laid out so as to be closer to the gate electrode 8 by a distance corresponding to those registration allowances. Therefore the area occupied by the memory cell in the first direction can be reduced.
Specifically, even if the connection holes 43 , 44 , 45 and 46 overlap the gate electrode 8 when they are formed by etching the silicon nitride film 13 , they do not reach the gate electrode 8 because the silicon nitride film 56 , thicker than the silicon nitride film 13 , is formed over the gate electrode 8 . Since, moreover, there is a large difference in the etching rate between the silicon nitride film and the silicon oxide film, the side wall spacers 11 , which are composed of the silicon oxide film on the individual side walls of the gate electrode 7 (or the word line WL) and the gate electrode 8 , are hardly etched when the silicon nitride film 13 is etched to form the connection holes 43 , 44 , 45 and 46 .
As a result, even if those connection holes 43 to 46 overlap the gate electrode 8 when they are formed, the conductive film deposited in the connection holes 43 to 46 and the gate electrode 8 do not short circuit at a later step.
Next, as shown in FIGS. 73 and 74, a TiN film having a thickness of about 100 nm is deposited over the silicon nitride film 13 by a sputtering method or a CVD method, and a silicon nitride film 47 having a thickness of about 100 nm is then deposited over that TiN film by a CVD method. After this, the silicon nitride film 47 and the TiN film are patterned by a dry-etching method using a photoresist as the mask to form paired local wiring lines L 1 and L 2 composed of the TiN film.
The local wiring line L 1 is connected through the connection hole 43 and the connection hole 58 with the gate electrode 8 of the drive MISFET Qd 2 (the load MISFET Qp 2 ), through the connection hole 43 with the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 1 , and through the connection hole 46 with the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 1 . The local wiring line L 2 is connected through the connection hole 44 and the connection hole 57 with the gate electrode 8 of the drive MISFET Qd 1 (the load MISFET Qp 1 ) through the connection hole 44 with the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 2 , and through the connection hole 45 with the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 2 .
The local wiring line L 1 is so arranged as to overlap with the gate electrode 8 of the drive MISFET Qd 1 (the load MISFET Qp 1 ) and the gate electrode 7 (the word line WL) of the transfer MISFETs Qt 1 and Qt 2 , and the local wiring line L 2 is so arranged as to overlap with the gate electrode 8 of the drive MISFET Qd 2 (the load MISFET Qp 2 ) and the gate electrode 7 (the word line WL) of the transfer MISFETs Qt 1 and Qt 2 . Thanks to this construction, a capacitor element C′ is formed of the local wiring line L 1 , the gate electrode 8 and the silicon nitride film 13 interposed therebetween, and a capacitor element C′ is formed of the local wiring line L 2 , the gate electrode 8 and the silicon nitride film 13 interposed therebetween, so that the amount of charge of the storage node can be increased to improve the alpha particle soft error resistance of the memory cell.
Next, as shown in FIG. 75, a silicon nitride film 59 is deposited by a CVD method over the silicon nitride film 47 covering the local wiring lines L 1 and L 2 , and an interlayer insulating film 49 of PSG is deposited over the silicon nitride film 59 by the CVD method.
Next, as shown in FIG. 76 and 77, the interlayer insulating film 49 over the individual p-type semiconductor regions 9 and 9 (the source regions) of the load MISFETs Qp 1 and Qp 2 are opened by a dry etching method using a photoresist as the mask to form connection holes 50 and 50 .
Simultaneously with this, the interlayer insulating film 49 over the individual n-type semiconductor regions 5 and 5 (the source regions) of the drive MISFETs Qd 1 and Qd 2 are opened to form connection holes 51 and 51 , and the interlayer insulating film 49 over the individual n-type semiconductor regions 5 and 5 (the drain regions) of the transfer MISFETs Qt 1 and Qt 2 are opened to form connection holes 52 and 52 . This etching treatment is interrupted at the instant when the silicon nitride film 59 is exposed at the bottoms of the connection holes 50 , 51 and 52 .
Next, the etching gas for the silicon oxide is changed to that for the silicon nitride, to etch the silicon nitride film 59 in the connection holes 50 , 51 and 52 and the thin silicon nitride film 13 below the former, as shown in FIG. 78 . This etching treatment is carried out in the connection holes 50 , 51 and 52 under the condition that the side wall spacers are formed on the individual side walls of the gate electrode 7 (the word line WL), the gate electrode 8 and the local wiring lines L 1 and L 2 .
Thus, in the foregoing embodiment 3, the connection holes 50 , 51 and 52 are formed in the Interlayer insulating film 49 after the side wall spacers 48 have been formed in advance on the individual side walls of the gate electrode 7 (the word line WL), the gate electrode 8 and the local wiring lines L 1 and L 2 . In the present embodiment, on the contrary, the side wall spacers of silicon nitride are formed when the connection holes 50 , 51 and 52 are formed by opening the interlayer insulating film 49 .
In this embodiment, like embodiment 3, the gate electrode 7 (the word line WL), the gate electrode 8 and the local wiring lines L 1 and L 2 are not exposed on the side walls of the connection holes 50 , 51 and 52 even if the connection holes 50 , 51 and 52 , the gate electrode 7 (the word line WL), and the gate electrode 8 overlap with each other and the connection holes 50 , 51 , and 52 and the local wiring lines overlap each other due to the misregistration of the photoresist mask. In short, in the case the manufacturing method of the present embodiment is used, when the connection holes 50 , 51 and 52 are laid out, it is unnecessary to take into consideration the registration allowance between the connection holes 50 , 51 and 52 and the local wiring lines L 1 and L 2 and the registration allowance between the connection holes 50 , 51 and 52 and the gate electrode 7 (the word line WL) and the gate electrode 8 . As a result, the connection holes 50 , 51 and 52 can be laid out so as to be closer to the local wiring lines L 1 and L 2 , the gate electrode 7 (the word line WL) and the gate electrode 8 by a distance corresponding to those registration allowances so that the area to be occupied by the memory cell can be reduced.
In order that the side wall spacers formed by the silicon nitride film 59 may function as the etching stopper, the thickness of the silicon nitride film 59 is made larger than the registration allowance of the aforementioned photoresist mask.
Next, as shown in FIGS. 79 and 80, the power supply voltage line 22 , the reference voltage line 23 and the intermediate wiring line 54 are formed over the interlayer insulating film 49 in accordance with the manufacturing method of the aforementioned embodiment 3. Next, as shown in FIGS. 81 and 82, the interlayer insulating film 26 is deposited over the power supply voltage line 22 , the reference voltage line 23 and the intermediate wiring line 54 , and the interlayer insulating film 26 over the intermediate wiring line 54 is opened to form the connection hole 55 by a dry-etching method using a photoresist as the mask. After this, the data lines DL and DL are 5 formed over the interlayer insulating film 26 .
According to the manufacturing method of the present embodiment, there are required neither the registration allowance between the connection holes 50 , 51 and 52 and the local wiring lines L 1 and L 2 nor the registration allowance between the connection holes 50 , 51 and 52 and the gate electrode 7 (the word line WL) and the gate electrode 8 , and further neither the registration allowance between the connection holes 43 and 44 and the gate electrode 8 nor the registration allowance between the connection hole 43 and the n-type semiconductor region 5 (between the connection hole 44 and the p-type semiconductor region 9 ). As a result, the memory cell can be made smaller than that of the foregoing embodiment 3.
Embodiment 5
In the SRAM of the present embodiment, the paired local wiring lines L 1 and L 2 are formed in different conductive layers, so that a capacitor element C is formed of the upper local wiring line L 2 , the lower local wiring line L 1 and a thin insulating film interposed therebetween. The method for manufacturing the memory cell of this SRAM will be described with reference to FIGS. 83, 84 ( a ) and ( b ), 85 , 86 ( a ) and ( b ), 87 , 88 ( a ) and ( b ), 89 , 90 ( a ) and ( b ), 91 ( a ) and ( b ), 92 , 93 ( a ) and ( b ), 94 , 95 ( a ) and ( b ), 96 and 97 ( a ) and ( b ).
First of all, as shown in FIGS. 83 and 84 ( a ) and ( b ), in accordance with the manufacturing method of the foregoing embodiment 1, the element isolating groove 2 and then the p-type well 3 and the n-type well 4 are formed in a major face of the semiconductor substrate 1 , and the gate oxide film 6 of the MISFET is formed over the p-type well 3 and the n-type well 4 . After this, the drive MISFETs Qd 1 and Qd 2 and the transfer MISFETs Qt 1 and Qt 2 are formed in the p-type well 3 , and the load MISFETs Qp 1 and Qp 2 are formed in the n-type well 4 . The gate electrode 7 (the word line WL) and the gate electrode 8 are composed of a polycrystalline silicon film, and the cap insulating film is composed of the silicon oxide film 12 . The side wall spacers 11 on the individual side walls of the gate electrode 7 (the word line WL) and the gate electrode 8 are formed by etching a silicon oxide film.
Next, as shown in FIGS. 85 and 86 ( a ) and ( b ), in accordance with the manufacturing method of the foregoing embodiment 3, the Ti-silicide layer 10 is formed to reduce the sheet resistance over the individual surfaces of the gate electrode 7 (the word line WL) of the transfer MISFETs Qt 1 and Qt 2 , the gate electrode 8 and 8 of the drive MISFETs Qd 1 and Qd 2 (the load MISFETs Qp 1 and Qp 2 ), the individual n-type semiconductor regions 5 and 5 (the source region and the drain region) of the transfer MISFETs Qt 1 and Qt 2 and the drive MISFETs Qd 1 and Qd 2 , the individual p-type semiconductor regions 9 and 9 (the source region and the drain region) of the load MISFETs Qp 1 and Qp 2 .
Next, as shown in FIGS. 87 and 88 ( a ) and ( b ), the silicon nitride film 13 , deposited over the semiconductor substrate by a CVD method and having a small thickness of about 50 nm, is etched to form the connection hole 14 over the gate electrode 8 of the drive MISFET Qd 2 (the load MISFET Qp 2 ), the connection hole 40 over the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 1 and the connection hole 41 over the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 1 . After this, the TiN film, deposited over the silicon nitride film 13 by a sputtering method or a CVD method and having a thickness of about 100 nm, is patterned to form the local wiring line L 1 . This local wiring line L 1 is given an area wide enough to cover the six MISFETs constituting the memory cell. The local wiring line L 1 is connected through the connection hole 14 with the gate electrode 8 of the drive MISFET Qd 2 (the load MISFET Qp 2 ), through the connection hole 40 with the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 1 , and through the connection hole 41 with the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 1 .
Next, as shown in FIGS. 89 and 90 ( a ) and ( b ), the silicon nitride film 42 , deposited over the semiconductor substrate 1 by a CVD method and having a small thickness of about 30 nm, is etched to form the connection hole 18 over the gate electrode 8 of the drive MISFET Qd 1 (or the load MISFET Qp 1 ), the connection hole 19 over the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 2 , and the connection hole 20 over the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 2 . After this the local wiring line L 2 of a TiN film is formed over the silicon nitride film 42 . The local wiring line L 2 is connected through the connection hole 18 with the gate electrode 8 of the drive MISFET Qd 1 (the load MISFET Qp 1 ), through the connection hole 19 with the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 2 , and through the connection hole 20 with the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 2 .
The local wiring line L 2 is formed by depositing a TiN film having a thickness of about 100 nm over the silicon nitride film 42 by a sputtering method or a CVD method, by then depositing the silicon nitride film 47 having a thickness of about 100 nm over the TiN film by a CVD method, and thereafter by patterning the silicon nitride film 47 and the TiN film by a dry etching method using a photoresist as the mask. The local wiring line L 2 is given an area wide enough to cover the six MISFETs constituting the memory cell and to overlap the lower local wiring line L 1 substantially completely in the region excepting the open regions of the connection holes 18 , 19 and 20 and the registration allowance region. As a result, the capacitor element C is formed of the local wiring lines L 1 and L 2 (the paired electrodes) and the silicon nitride film 42 (the dielectric film) made thinner than the local wiring lines L 1 and L 2 . Moreover, the charge of the capacitor element C can be increased so that the amount of stored charge of the storage node can be increased to improve the alpha particle soft error resistance of the memory cell.
Next, as shown in FIGS. 91 ( a ) and ( b ), the side wall spacers 48 are formed on the individual side walls of the gate electrode 8 , the lower local wiring line L 1 and the upper local wiring line L 2 . The side wall spacer 48 is also formed on the side wall of the gate electrode 7 (the word line WL), although not shown. The side wall spacers 48 are formed by etching a silicon nitride film which is deposited over the silicon nitride film 47 by a CVD method and has a thickness of about 200 nm.
Next, as shown in FIGS. 92 and 93 ( a ) and ( b ), the interlayer insulating film 49 of PSG having a thickness of about 400 nm is deposited over the silicon nitride film 47 by a CVD method. After this, the interlayer insulating film 49 is opened by a dry-etching method using a photoresist as the mask to form the connection holes 50 and 50 over the p-type semiconductor regions 9 and 9 (the source regions) of the load MISFETs Qp 1 and Qp 2 , the connection holes 51 and 51 over the n-type semiconductor region 5 and 5 (the source regions) of the drive MISFETs Qd 1 and Qd 2 , and the connection holes 52 and 52 over the n-type semiconductor regions 5 and 5 (the drain regions) of the transfer MISFETs Qt 1 and Qt 2 . Since, at this time, the side wall spacers 48 on the silicon nitride film act as the etching stoppers, neither the gate electrode 8 is exposed at the side walls of the connection holes 50 and 51 , nor is exposed the gate electrode 7 (the word line WL) at the side wall of the connection hole 52 . Likewise, neither the lower local wiring line L 1 nor the upper local wiring line L 2 is exposed at the side walls of the connection holes 50 , 51 and 52 .
In short, when the manufacturing method of the present embodiment is applied to the SRAM in which the paired local wiring lines L 1 and L 2 are arranged in the different conductive layers, it is unnecessary to take into consideration the registration allowance between the connection holes 50 , 51 and 52 and the upper local wiring line L 2 , and the registration allowance between the connection holes 50 , 51 and 52 and the gate electrode 7 (the word line WL) and the gate electrode 8 . As a result, the connection holes 50 , 51 and 52 can be so arranged as to be closer to the upper local wiring line L 2 , the lower local wiring line L 1 , the gate electrode 7 (word line WL) and the gate electrode 8 by a distance corresponding to those registration allowances so that the area occupied by the memory cell can be reduced. In order that the side wall spacers 48 may function as the etching stoppers when the interlayer insulating film 49 is etched, the thickness of the silicon nitride film constituting the side wall spacers 48 is made larger than the registration allowance of the aforementioned photoresist mask.
In the present embodiment, the side wall spacers 48 of the silicon nitride are formed in advance on the individual side walls of the gate electrode 7 (the word line WL), the gate electrode 8 , the lower local wiring line L 1 and the upper local wiring line L 2 , and the connection holes 50 , 51 and 52 are then formed in the interlayer insulating film 49 . As in the foregoing embodiment 4, the silicon nitride film and the interlayer insulating film 49 are deposited over the silicon nitride film 47 covering the upper local wiring line L 2 so that the side wall spacers may be formed when the interlayer insulating film 49 is opened to form the connection holes 50 , 51 and 52 .
Next, as shown in FIGS. 94 and 95 ( a ) and ( b ), in accordance with the manufacturing method of the foregoing embodiment 3, the power supply voltage line 22 , the reference voltage line 23 and the intermediate wiring line 54 are formed over the interlayer insulating film 49 . After this, as shown in FIGS. 96 and 97 ( a ) and ( b ), the interlayer insulating film 26 is deposited over the power supply voltage line 22 , the reference voltage line 23 and the intermediate wiring line 54 , and the interlayer insulating film 26 over the intermediate wiring line 54 is opened to form the connection hole 55 . After this, the data lines DL and DL are formed over the interlayer insulating film 26 .
According to the present embodiment, the paired local wiring lines L 1 and L 2 are formed in different conductive layers and are so arranged as to be superposed on each other so that the area occupied by the memory cell can be reduced. At the same time, there are made unnecessary the registration allowance between the connection holes 50 , 51 and 52 and the upper local wiring line L 2 , the registration allowance between the connection holes 50 , 51 and 52 and the lower local wiring line L 1 , and the registration allowance between the connection holes 50 , 51 and 52 and the gate electrode 7 (the word line WL) and the gate electrode 8 , so that the area occupied by the memory cell can be further reduced.
According to the present embodiment, the upper local wiring line L 2 and the lower local wiring line L 1 are so arranged as to overlap with each other over a wide area, and the capacitor element C is composed of the local wiring lines L 1 and L 2 and the thin insulating film interposed therebetween, so that the alpha particle soft error resistance of the memory cell can be improved.
Embodiment 6
In the SRAM of the present embodiment, the paired local wiring lines L 1 and L 2 are formed in different conductive layers, so that a capacitor element C is formed of the upper local firing line L 2 , the lower local wiring line L 1 and a thin insulating film interposed therebetween. The method for manufacturing the memory cell of this SRAM will be described with reference to FIGS. 98, 99 ( a ) and ( b ), 100 , 101 ( a ) and ( b ), 102 , 103 ( a ) and ( b ), 104 , 105 ( a ) and ( b ), 106 ( a ) and ( b ), 107 ( a ) and ( b ), 108 and 109 .
First of all, as shown in FIGS. 98 and 99 ( a ) and ( b ), in accordance with the manufacturing method of the foregoing embodiment 1, the element isolating groove 2 and then the p-type well 3 and the n-type well 4 are formed in a major face of the semiconductor substrate 1 , and the gate oxide film 6 of the MISFET is formed over the p-type well 3 and the n-type well 4 . After this, the drive MISFETs Qd 1 and Qd 2 and the transfer MISFETs Qt 1 and Qt 2 are formed in the p-type well 3 , and the load MISFETs Qp 1 and Qp 2 are formed in the n-type well 4 . The gate electrode 7 (the word line WL) and the gate electrode 8 are composed of a polycrystalline silicon 8 a and Ti-silicide film 8 b film, and the cap insulating film is composed of the silicon nitride film 12 a. The side wall spacers 11 on the individual side walls of the gate electrode 7 (the word line WL) and the gate electrode 8 are formed by anisotropically etching a silicon nitride film which is deposited over the gate electrodes 7 , 8 and the cap insulating film 12 a.
Next, as shown in FIGS. 100 and 101 ( a ) and ( b ), in accordance with the manufacturing method of the foregoing embodiment 1, the Ti-silicide layer 10 is formed to reduce the sheet resistance over the individual n-type semiconductor regions 5 and 5 (the source region and the drain region) of the load MISFETs Qp 1 and Qp 2 , and the individual p-type semiconductor regions 9 and 9 (the source region and the drain region) of the load MISFETs Qp 1 and Qp 2 .
Next, as shown in FIGS. 102 and 103 ( a ) and ( b ), the silicon oxide film 13 a, deposited over the semiconductor substrate by a CVD method and having a small thickness of about 50 nm, is etched to form the connection hole 14 over the gate electrode 8 of the drive MISFET Qd 2 (the load MISFET Qp 2 ), the connection hole 40 over the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 1 and the connection hole 41 over the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 1 . After this, a TiN film, deposited over the silicon nitride film 13 a by a sputtering method or a CVD method and having a thickness of about 100 nm, is patterned to form the local wiring line L 1 . This local wiring line L 1 is given an area wide enough to cover the six MISFETs constituting the memory cell. The local wiring line L 1 is connected through the connection hole 14 with the gate electrode 8 of the drive MISFET Qd 2 (the load MISFET Qp 2 ), through the connection hole 40 with the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 1 , and through the connection hole 41 with the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 1 .
Next, as shown in FIGS. 104 and 105 ( a ) and ( b ), the silicon nitride film 42 , deposited over the semiconductor substrate 1 by a CVD method and having a small thickness of about 30 nm, is etched to form the connection hole 18 over the gate electrode 8 of the drive MISFET Qd 1 (or the load MISFET Qp 1 ), the connection hole 19 over the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 2 , and the connection hole 20 over the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 2 . After this the local wiring line L 2 of a TiN film is formed over the silicon nitride film 42 . The local wiring line L 2 is connected through the connection hole 18 with the gate electrode 8 of the drive MISFET Qd 1 (the load MISFET Qp 1 ), through the connection hole 19 with the n-type semiconductor region 5 (the drain region) of the drive MISFET Qd 2 , and through the connection hole 20 with the p-type semiconductor region 9 (the drain region) of the load MISFET Qp 2 .
The local wiring line L 2 is formed by depositing a TiN film having a thickness of about 100 nm over the silicon nitride film 42 by a sputtering method or a CVD method, by then depositing the silicon nitride film 47 having a thickness of about 100 nm over the TiN film by a CVD method, and thereafter by patterning the silicon nitride film 47 and the TiN film by a dry etching method using a photoresist as the mask. The local wiring line L 2 is given an area wide enough to cover the six MISFETs constituting the memory cell and to overlap the lower local wiring line L 1 substantially completely in the region excepting the open regions of the connection holes 18 , 19 and 20 and the registration allowance region. As a result, the capacitor element C is formed of the local wiring lines L 1 and L 2 (the paired electrodes) and the silicon nitride film 42 (the dielectric film) made thinner than the local wiring lines L 1 and L 2 . Moreover, the charge of the capacitor element C can be increased so that the amount of stored charge of the storage node can be increased to improve the alpha particle soft error resistance of the memory cell.
Next, as shown in FIGS. 106 ( a ) and ( b ), the side wall spacers 48 a are formed on the individual side walls of the lower local wiring line L 1 and the upper local wiring line L 2 . The side wall spacer 11 a is also formed on the side wall of the gate electrode 7 , 8 (the word line WL). The side wall spacers 48 a are formed by anisotropically etching a silicon nitride film which is deposited over the silicon nitride film 47 by a CVD method and has a thickness of about 200 nm.
Next, as shown in FIGS. 107 ( a ) and ( b ) and 108 , the interlayer insulating film 49 of PSG having a thickness of about 400 nm is deposited over the silicon nitride film 47 by a CVD method. After this, the interlayer insulating film 49 is opened by a dry-etching method using a photoresist as the mask to form the connection holes 50 and 50 over the p-type semiconductor regions 9 and 9 (the source regions) of the load MISFETs Qp 1 and Qp 2 , the connection holes 51 and 51 over the n-type semiconductor region 5 and 5 (the source regions) of the drive MISFETs Qd 1 and Qd 2 , and the connection holes 52 and 52 over the n-type semiconductor regions 5 and 5 (the drain regions) of the transfer MISFETs Qt 1 and Qt 2 . Since, at this time, the side wall spacers 48 a, 11 a of the silicon nitride film and the silicon nitride film 47 act as etching stoppers, neither the gate electrode 8 is exposed at the side walls of the connection holes 50 and 51 , nor is exposed the gate electrode 7 (the word line WL) at the side wall of the connection hole 52 . Likewise, neither the lower local wiring line L 1 nor the upper local wiring line L 2 is exposed at the side walls of the connection holes 50 , 51 and 52 .
In short, when the manufacturing method of the present embodiment is applied to the SRAM in which the paired local wiring lines L 1 and L 2 are arranged in different conductive layers, it is unnecessary to take into consideration the registration allowance between the connection holes 50 , 51 and 52 and the upper local wiring line L 2 , and the registration allowance between the connection holes 50 , 51 and 52 and the gate electrode 7 (the word line WL) and the gate electrode 8 . As a result, the connection holes 50 , 51 and 52 can be so arranged as to be closer to the upper local wiring line L 2 , the lower local wiring line L 1 , the gate electrode 7 (word line WL) and the gate electrode 8 by a distance corresponding to those registration allowances so that the area occupied by the memory cell can be reduced. In order that the side wall spacers 48 a, 11 a, and the silicon nitride film 47 may function as the etching stoppers when the interlayer insulating film 49 is etched, the thickness of the silicon nitride film constituting the side wall spacers 48 a is made larger than the registration allowance of the aforementioned photoresist mask.
In the present embodiment, the side wall spacers 48 a, 11 a of the silicon nitride are formed in advance on the individual side walls of the gate electrode 7 (the word line WL), the gate electrode 8 , the lower local wiring line L 1 and the upper local wiring line L 2 , and the connection holes 50 , 51 and 52 are then formed in the interlayer insulating film 49 . As in the foregoing embodiment 4, the silicon nitride film and the interlayer insulating film 49 can be deposited over the silicon nitride film 47 covering the upper local wiring line L 2 so that the side wall spacers may be formed when the interlayer insulating film 49 is opened to form the connection holes 50 , 51 and 52 .
Next, as shown in FIGS. 107 ( a ) and ( b ) and 109 , in accordance with the manufacturing method of the foregoing embodiment 3, the power supply voltage line 22 , the reference voltage line 23 and the intermediate wiring line 54 are formed over the interlayer insulating film 49 . After this, as shown in FIGS. 96 and 97 ( a ) and ( b ), the interlayer insulating film 26 is deposited over the power supply voltage line 22 , the reference voltage line 23 and the intermediate wiring line 54 , and the interlayer insulating film 26 over the intermediate wiring line 54 is opened to form the connection hole 55 . After this, the data lines DL and DL are formed over the interlayer insulating film 26 .
According to the present embodiment, the paired local wiring lines L 1 and L 2 are formed in different conductive layers and are so arranged as to be superposed on each other so that the area occupied by the memory cell can be reduced. At the same time, there are made unnecessary the registration allowance between the connection holes 50 , 51 and 52 and the upper local wiring line L 2 , the registration allowance between the connection holes 50 , 51 and 52 and the lower local wiring line L 1 , and the registration allowance between the connection holes 50 , 51 and 52 and the gate electrode 7 (the word line WL) and the gate electrode 8 , so that the area occupied by the memory cell can be further reduced.
According to the present embodiment, the upper local wiring line L 2 and the lower local wiring line L 1 are so arranged as to overlap with each other over a wide area, and the capacitor element C is composed of the local wiring lines L 1 and L 2 and the thin insulating film interposed therebetween, so that the alpha particle soft error resistance of the memory cell can be improved.
Although our invention has been specifically described in connection with its embodiments, it should not be limited thereto but can naturally be modified in various manners without departing from the gist thereof.
The metal material of the local wiring lines can be selected from a variety of materials in addition to those of the foregoing embodiments. For example, the lower local wiring line may be made of a first-layer aluminum metal (TiN/Al/TiN) whereas the upper local wiring line may be made of a second-layer aluminum metal. In this case, the power supply voltage line and the reference voltage line are made of a third layer aluminum metal whereas the complementary data lines are made of a fourth-layer aluminum metal.
The effects obtained by the present invention disclosed herein will be briefly described in the following.
According to the SRAM of the present invention, the paired local wiring lines cross-connecting the input/output terminals of the flip-flop circuit of the memory cell are formed in different conductive layers. As a result, the space, required to arrange the paired local wiring lines transversely when the two local wiring lines are composed of a common conductive film, can be eliminated, so that the local wiring lines can be so arranged as to overlap partially to reduce the area occupied by the memory cell.
According to the SRAM of the present invention, the lower local wiring line and the upper local wiring line are so arranged as to overlap with each other, and a capacitor element is composed of those local wiring lines and the insulating film interposed therebetween. As a result, the storage node capacitance of the memory cell can be increased to prevent a drop in the alpha particle soft error resistance which may be caused by the miniaturization of the memory cell size and the drop in the operation power supply voltage.
According to the SRAM of the present invention, refractory metal silicide layers of a low resistance material are formed on the surfaces of the source and drain regions of the drive MISFETs, the load MISFETs and the transfer MISFETs constituting the memory cell, so that the high-speed operation of the memory cell can be realized.
According to the SRAM of the present invention, the active region of the semiconductor substrate (the p-type well) where the drive MISFETs and the transfer MISFETs are formed, and the active region of the semiconductor substrate (the n-type well) where the load MISFETs are formed, are isolated by the grooves which are opened in the semiconductor substrate. As a result, the area occupied by the element isolating region can be made lower than that of the case that the isolation is achieved by the field insulating film formed by a LOCOS method, so that the area occupied by the memory cell can be reduced.
According to the method for manufacturing the SRAM of the present invention, the mask registration allowance, when the connection holes are made in the interlayer insulating film by using a photoresist as the mask, can be eliminated to reduce the area occupied by the memory cell.
While we have shown and described several embodiments in accordance with the present invention, it is understood that the same is not limited thereto, but is susceptible of numerous changes and modifications as known to those skilled in the art. Therefore, we do not wish to be limited to the details shown and described herein, but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims. | Disclosed is a semiconductor integrated circuit device (e.g., an SRAM) having memory cells each of a flip-flop circuit constituted by a pair of drive MISFETs and a pair of load MISFETs, the MISFETs being cross-connected by a pair of local wiring lines, and having transfer MISFETs, wherein gate electrodes of all of the MISFETs are provided in a first level conductive layer, and the pair of local wiring lines are provided respectively in second and third level conductive layers. The local wiring lines can overlap and have a dielectric therebetween so as to form a capacitance element, to increase alpha particle soft error resistance. Moreover, by providing the pair of local wiring lines respectively in different levels, integration of the device can be increased. Side wall spacers can be provided on the sides of the gate electrodes of the MISFETs and on the sides of the local wiring lines, and connection holes to semiconductor regions of these MISFETs are self-aligned to both the gate electrodes and the local wiring lines, whereby capacitor area can be increased and integration of the device can also be increased. | 8 |
BACKGROUND
1. Technical Field
The present disclosure relates to electrical connectors and, more particularly, to electrical connector housings which are configured and adapted to reduce breakage of latch members thereof.
2. Discussion of Related Art
Housings for certain electrical connectors are molded from dielectric plastic material and are intended to be secured to mating or complementary connector receptacles when the connector and receptacle has been moved together in a mated condition. In so doing the respective arrays of electrical contacts are mated to complete electrical connections therebetween. In some of these connectors or receptacles, hardware is fastened to or structures are provided on the respective housings to ensure proper and secure mating of the connector with the receptacle when in the mated condition. Desirably, each respective housing includes an integral latching element or the like. For example, integrally molded latch arms may be disposed along opposed sides of the housing of one of the connector and receptacle and may extend forwardly to latchingly engage with corresponding/complementary latching surfaces of the housing of the other of the connector and receptacle, when the connector and receptacle are moved together into a mated condition.
Exemplary latch arms used for securing connector and receptacles together are disclosed in U.S. Pat. No. 4,867,700, the entire content of which is incorporated herein by reference, and assigned to assignee hereof. The latch arms include rearward portions which are deflectable to unlatch the latch arms when it is desired to separate and unmate the connector and the receptacle, in which case the latch arms can be said to be hingedly joined to the housing.
Such latch arms are subjected to stress and torque during mating and unmating of the connector and receptacle. Accordingly, the hinge joint must be rugged and durable to withstand many cycles of mating and unmating, especially taking into consideration that the hinge joint is molded of plastic material which can commonly lose strength over time when worked and subjected to temperature cycling as well.
A need exists for an electrical connector or connector receptacle which is configured and adapted to reduce the degree of torque transmitted to the latch arms or the like.
A need further exists for an electrical connector or connector receptacle which is configured and adapted to reduce the degree of motion of the latch arm and/or reduces the degree of flexure in the hinge connecting the latch arm to the connector or receptacle.
SUMMARY
The present disclosure relates to electrical connector housings which are configured and adapted to reduce breakage of latch arms thereof.
According to an aspect of the present disclosure, an electrical connector for mating with a complementary connector receptacle is provided. The electrical connector includes a housing configured and adapted for selective matable connection with a corresponding complementary connector receptacle; a pair of latch arms provided on opposite sides of the housing; and a pair of latch guards extending from the sides of the housing and overlying at least a portion of a respective latch arm. Each latch arm includes latching projections at a forward end of the latch arm which are configured and adapted for selective engagement with corresponding latching means provided on the connector receptacle; and a hinge joint spaced a selected distance rearwardly from the forward end thereof for joining the latch arm to a respective side of the housing. Accordingly, as a latch arm is twisted about the hinge joint, at least a portion of the latch arm abuts against the respective latch guard and additional twisting of the latch arm about the hinge joint is prevented.
Each latch guard may extend distally and proximally of the hinge joint.
Each latch arm may include a first stop feature extending therefrom at a location between the latching projection and the hinge joint. The first stop feature desirably extends towards the housing. Accordingly, upon twisting of the latch arm about the hinge joint, the first stop feature is engagable with the respective latch guard to stop twisting of the latch arm.
Each latch arm desirably includes a rearward portion extending rearwardly from the respective hinge joint. Each latch arm may include a second stop feature extending therefrom at a location rearward of the hinge joint. The second stop feature desirably extends towards the housing.
In use, upon twisting of the latch arm about the hinge joint, the second stop feature is engageable with the respective latch guard to stop twisting of the latch arm.
Each latch arm is desirably deflectable about the hinge joint. Accordingly, flexure of the forward end of the latch arm toward the housing is stopped by the first stop feature. Additionally, flexure of the rearward end of the latch arm toward the housing is stopped by the second stop feature.
It is envisioned that the housing and the latch arms are fabricated from a dielectric material.
According to another aspect of the present disclosure, wherein an electrical connector for selective mating with a complementary connector receptacle is provided, and wherein the electrical connector includes a housing, a pair of latch arms hingedly connected to and extending from opposite sides of the housing, the improvement includes a pair of latch guards extending from opposite sides of the housing. Each latch guard overlies at least a portion of a respective latch arm. The latch guards stop twisting of the latch arms about the hinge joint in a direction transverse to a longitudinal axis of the latch arms.
Each latch arm desirably includes a latching projection at a forward end thereof for selectively engaging a corresponding latching means provided on the connector receptacle.
The hinge joint is desirably spaced a selected distance rearwardly from the forward end of the latch arm. Desirably, each latch guard extends distally and proximally of the hinge joint.
In use, the latch guards stop twisting of the latch arms about an axis transverse to a pivot axis of the hinge joint.
Each latch arm may include a first stop feature extending therefrom at a location between the latching projection and the hinge joint. In use, upon twisting of the latch arm about the hinge joint, the first stop feature is engagable with the respective latch guard to stop twisting of the latch arm. Each latch arm may include a rearward portion extending rearwardly from the respective hinge joint. Each latch arm may further include a second stop feature extending therefrom at a location rearward of the hinge joint. As such, upon twisting of the latch arm about the hinge joint, the second stop feature is engageable with the respective latch guard to stop twisting of the latch arm.
For a better understanding of the present invention and to show how it may be carried into effect, reference will now be made by way of example to the accompanying drawings.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an electrical connector according to an embodiment of the present disclosure;
FIG. 2 is a top, perspective view of a bottom half-shell of the electrical connector of FIG. 1 ;
FIG. 3 is a top, plan view of the bottom half-shell of FIGS. 1 and 2 ;
FIG. 4 is a bottom, plan view of the bottom half-shell of FIGS. 1–3 ;
FIG. 5 is a front, elevational view of the bottom half-shell of FIGS. 1–4 ;
FIG. 6 is a side elevational view of the bottom half-shell of FIGS. 1–5 ;
FIG. 7 is a top, perspective view of a top half-shell of the electrical connector of FIG. 1 ;
FIG. 8 is a bottom, plan view of the top half-shell of FIGS. 1 and 7 ;
FIG. 9 is a top, plan view of the top half-shell of FIGS. 1 , 7 and 8 ;
FIG. 10 is a front, elevational view of the top half-shell of FIGS. 1 and 7 – 9 ;
FIG. 11 is a side elevational view of the top half-shell of FIGS. 1 and 7 – 10 , and
FIG. 12 is a side elevational view of the electrical connector of FIG. 1 , illustrating the blocking feature of the latch guards.
DETAILED DESCRIPTION OF EMBODIMENTS
Embodiments of the presently disclosed electrical connector will now be described in detail with reference to the drawing figures wherein like reference numerals identify similar or identical elements. As used herein and as is traditional, the term “distal” refers to that portion which is furthest from the user while the term “proximal” refers to that portion which is closest to the user. In addition, terms such as “above”, “below”, “forward”, “rearward”, etc. refer to the orientation of the figures or the direction of components and are simply used for convenience of description.
Referring to FIGS. 1–11 , an electrical connector, according to an embodiment of the present disclosure, is generally designated as 100 . Connector 100 includes a housing 102 having a top half-shell 102 a and a bottom half-shell 102 b . As seen in FIG. 1 , housing 102 includes a receiving recess 104 having a plurality of electrical contact channels 106 formed therein. Each contact channel 106 may include an electrical contact therein (not shown) for electrical connection with a complementary electrical contact of a connector receptacle (not shown). Contact channel 106 is particularly shaped to mate with a complementary element or structure of the connector receptacle.
Housing 102 , including top half-shell 102 a and/or bottom half-shell 102 b , may be made from a dielectric material. Desirably, top half-shell 102 a and bottom half-shell 102 b are secured to one another by fastening means, such as screws 108 , or other securing structures, such as, for example, clips, snap-fit engaging structure and the like.
Electrical connector 100 , as described herein, is an eight position connector for use with an eight wire communications cable. However, it should be understood that the invention can also be applied to other connectors which are terminable to different numbers of wires.
As seen in FIGS. 1–6 , bottom half-shell 102 b of housing 102 includes a bottom wall 112 , a rear wall 114 extending substantially orthogonally from bottom wall 112 , and a pair of spaced apart side walls 116 a , 116 b extending substantially orthogonally from bottom wall 112 . Bottom half-shell 102 b includes a plurality of channels 118 a – 118 d formed therein for accommodating electrical contacts and/or wire cables therein.
With continued reference to FIGS. 1–6 , electrical connector 100 further includes a pair of latch arms 120 , 122 integrally joined to side walls 116 a , 116 b of bottom half-shell 102 b of housing 102 at respective flexible integral hinge joints 124 , 126 located approximately midway along latch arms 120 , 122 . Each latch arm 120 , 122 includes a respective forward portion 120 a , 122 a concluding in a free end 120 b , 122 b . Each free end 120 b , 122 b of latch arms 120 , 122 includes a latching projection 120 c , 122 c , respectively, which extends towards a respective side wall 116 a , 116 b of bottom half-shell 102 b . Each projection 120 c , 122 c defines a latching surface 120 d , 122 d . In use, latching surfaces 120 d , 122 d selectively engage corresponding complementary recesses (not shown) provided in or on the connector receptacle.
Each latch arm 120 , 122 further includes a respective rearward portion 120 e , 122 e extending rearwardly from respective hinge joints 124 , 126 . Desirably, rearward portions 120 e , 122 e of latch arms 120 , 122 are configured and adapted for gripping by a user.
Each hinge joint 124 , 126 is capable of enabling latch arm deflection in a plane “P” (see FIGS. 1 , 5 , 6 , 10 and 11 ). Plane “P” is desirably co-planar to an upper or lower surface of housing 102 of electrical connector 100 , or orthogonal to a front surface of housing 102 of electrical connector 100 . In particular, each latch arm 120 , 122 may be deflected at or about respective hinge joints 124 , 126 , so as to move in plane “P” in the direction of arrows “A”, as seen in FIGS. 3 and 4 .
Desirably, each latch arm 120 , 122 includes a distal or first stop feature 121 a , 123 a , respectively, projecting from an inner surface of forward portion 120 a , 122 a , towards respective side walls 116 a , 116 b of bottom half-shell 102 b . In use, as will be described in greater detail below, distal stop features 121 a , 123 a prevent excessive or over-flexure of forward portions 120 a , 122 a of latch arms 120 , 122 toward side walls 116 a , 116 b of bottom half-shell 102 b . In particular, if forward portions 120 a , 122 a of latch arms 120 , 122 are deflected towards respective side walls 116 a , 116 b of bottom half-shell 102 b , stop features 121 a , 123 a abut against respective side walls 116 a , 116 b of bottom half-shell 102 b and prevent further flexure of forward portion 120 a , 122 a towards respective side walls 116 a , 116 b of bottom half-shell 102 b.
Each latch arm 120 , 122 further includes a proximal or second stop feature 121 b , 123 b , respectively, projecting from an inner surface of rearward portion 120 e , 122 e , towards respective side walls 116 a , 116 b of bottom half-shell 102 b . In use, as will be described in greater detail below, proximal stop features 121 b , 123 b prevent excessive or over-flexure of rearward portions 120 e , 122 e of latch arms 120 , 122 toward side walls 116 a , 116 b of bottom half-shell 102 b . In particular, if rearward portions 120 e , 122 e of latch arms 120 , 122 are deflected towards respective side walls 116 a , 116 b of bottom half-shell 102 b , stop features 121 b , 123 b abut against respective side walls 116 a , 116 b of bottom half-shell 102 b and prevent further flexure of rearward portion 120 e , 122 e towards respective side walls 116 a , 116 b of bottom half-shell 102 b.
During mating of electrical connector 100 to a complementary connector receptacle, forward portions 120 a , 122 a of latch arms 120 , 122 are deflected outwardly (i.e., away from side walls 116 a , 116 b of bottom half-shell 102 b ) near respective free ends 120 b , 122 b as latching projections 120 c , 122 c ride over mating projections provided on the connector receptacle (not shown). As forward portions 120 a , 122 a of latch arms 120 , 122 are deflected outwardly, rearward portions 120 e , 122 e of latch arms 120 , 122 deflect inwardly due to the pivoting or flexure about hinge joints 124 , 126 . Over deflection or over flexure of rearward portions 120 e , 122 e of latch arms 120 , 122 is prevented when proximal stop features 121 b , 123 b of latch arms 120 , 122 abut against and/or otherwise contact side walls 116 a , 116 b of bottom half-shell 102 b . Upon complete and proper mating, latching surfaces 120 d , 122 d of latch arms 120 , 122 latch behind the respective projections provided on the connector receptacle (not shown).
Turning now to FIGS. 1 and 7 – 10 , top half-shell 102 a of housing 102 includes a top wall 132 , a rear wall 134 extending substantially orthogonally from top wall 132 , and a pair of spaced apart side walls 136 a , 136 b extending substantially orthogonally from top wall 132 . Top half-shell 102 a includes a plurality of channels 138 a – 138 d formed therein for accommodating electrical contacts and/or wire cables therein. Channels 138 a – 138 d of top half-shell 102 a correspond to and register with channels 118 a – 118 d of bottom half-shell 102 b.
With continued reference to FIGS. 1 and 7 – 11 , top half-shell 102 a includes a latch guard, wall, ledge or flange 140 , 142 projecting from each side wall 136 a , 136 b thereof. Desirably, each latch guard 140 , 142 extends from a front edge of side wall 136 a , 136 b proximally along substantially an entire length of side wall 136 a , 136 b . More desirably, latch guards 140 , 142 substantially overlie respective latch arms 120 , 122 of bottom half-shell 102 b when top half-shell 102 a is connected to bottom half-shell 102 b.
As seen in FIGS. 1 and 12 , at least distal stop features 121 a , 123 a of latch arms 120 , 122 extend at least partially beneath respective latch guards 140 , 142 . Additionally, at least a portion of rearward portions 120 e , 122 e of latch arms 120 , 122 are disposed beneath latch guards 140 , 142 . Accordingly, in use, excessive twisting of latch arms 120 , 122 , about hinge joints 124 , 126 (i.e., in a direction orthogonal to plane “P” of the latch arm 120 , 122 and orthogonal to a longitudinal axis of the latch arms 120 , 122 or about rotational axis “C”) is prevented by latch guards 140 , 142 . The abutment of latch arm 122 , either at a forward end of latch guard 142 or at a rearward end of latch guard 142 , is shown in phantom in FIG. 12 .
In particular, if, during manipulation of electrical connector 100 or during mating of electrical connector 100 to a connector receptacle, either latch arm 120 , 122 should twist about hinge joints 124 , 126 (i.e., forward portions 120 a , 122 a of latch arms 120 , 122 deflect in a direction transverse to the pivot plane of the latch arms 120 , 122 ) at least a portion of the latch arm 120 , 122 (e.g., stop features 121 a , 123 a , 121 b , 123 b ) will abut against a respective latch guard 140 , 142 and prevent or inhibit any further twisting of latch arm 120 , 122 about hinge joints 124 , 126 in a direction transverse to the pivot plane.
Provision of latch guards 140 , 142 on electrical connector 100 reduce the risk of damage to latch arms 120 , 122 as a result of excessive twisting of latch arms 120 , 122 as described above.
Desirably, housing 102 and latch arms 120 , 122 are fabricated from dielectric materials, including and not limited to plastic and the like.
It is to be understood that the foregoing description s merely a disclosure of particular embodiments and is no way intended to limit the scope of the invention. Other possible modifications will be apparent to those skilled in the art and all modifications are to be defined by the following claims. | An electrical connector for mating with a complementary connector receptacle is provided and includes a housing configured and adapted for selective matable connection with a corresponding complementary connector receptacle; a pair of latch arms provided on opposite sides of the housing; and a pair of latch guards extending from the sides of the housing and overlying at least a portion of a respective latch arm. Each latch arm includes a hinge joint spaced a selected distance rearwardly from a forward end thereof for joining the latch arm to a respective side of the housing. Accordingly, as a latch arm is twisted about the hinge joint, at least a portion of the latch arm abuts against the respective latch guard and additional twisting of the latch arm about the hinge joint is prevented. | 7 |
FIELD OF THE INVENTION
[0001] The present invention relates to a refiner plate, which is typically used in a type of milling machine known as an attrition mill or disc refiner.
BACKGROUND
[0002] Different types of “engineered” wood particles are used to produce a corresponding variety of engineered wood products. In the production of highly refined wood products such as fiberboard and paper, chips or other comminuted wood or wood refuse is milled or ground to produce small “particles” or bundles of fibers. Attrition mills or “disc refiners” are commonly used for this purpose. As a class, these produce a fine defibration and fibers with a high degree of slenderness.
[0003] Two general types of disc refiners are the “single-revolving-disc” and the “double-revolving-disc.” Both types rely on relative spinning motion between two coaxially disposed discs defining a small gap between opposed, grinding faces of the discs. In the single-revolving-disc design, one of the discs is stationary, while in the double-revolving-disc design, the two discs counter-rotate.
[0004] Raw material, typically chips, is input to the disc refiner substantially along the axis of rotation of the disc(s). The material is flung radially outwardly through the gap as a result of centrifugal force imparted to the material as a result of contact with the grinding faces of the spinning disc(s).
[0005] Two such discs 2 a , 2 b , are shown in cross-section in FIG. 1 . There is a gap “G” between grinding faces 3 of the two discs through which the material being worked travels as it is refined into particles. Due to elasticity and therefore flexure of the discs, the spacing of the gap “G” changes as a result of the forces encountered when working the material. Particularly, the presence of the material tends to spread the discs apart.
[0006] This is typically compensated for by providing a slight “face taper” on the discs, shown highly exaggerated in FIG. 1 , so that the grinding faces 3 are not absolutely perpendicular to the axis of rotation L when the discs are not processing any material. The face taper is small, so that the grinding face is flat to within about 0.0025″ even when unloaded.
[0007] FIG. 2 shows an annular sector of one of the discs 2 looking down the axis of rotation L. The axis of rotation L is an axis of azimuthal symmetry of the disc. Visible on the disc 2 is the grinding face 3 . With additional reference to FIG. 3 showing a cross-section of the disc, the grinding face 3 is defined by top surfaces 4 a of protruding structures 4 known and referred to in the art as “bars.” The bars 4 project above an annular body portion 9 of the disc.
[0008] The top surfaces 4 a of all of the bars are typically at the same elevation “h bar ” with respect to a reference plane “P REF ” ( FIG. 3 ) that is perpendicular to the axis of rotation L. The top surfaces h bar of two opposed discs provide the desired grinding action.
[0009] Referring back to FIGS. 2 and 3 , raw material flows across the grinding face 3 in the directions indicated as “D FLOW ,” i.e., radial directions r with respect to the axis L. Due to the azimuthal symmetry of the bars shown in this example, the disc 2 may equally well spin in either of the directions indicated as “D SPIN .”
[0010] The bars 4 are spaced apart by depressions known and referred to in the art as “grooves” 5 , the top surfaces 5 a of which are at a lower elevation “h groove ,” than the top surfaces 4 a of the bars.
[0011] The grooves 5 are typically provided with a radially spaced apart series of structures known and referred to in the art as “dams” 6 that extend cross-wise across the grooves to join adjacent bars. The dams 6 have top surfaces 6 a that are at an elevation “h dam ” that is, at least for the most part, lower in elevation than the top surfaces of the bars; however the elevation of a given dam increases with the dam's radial distance from the axis L, and the top surface 6 a of the radially outermost dam is often at the same elevation as the top surfaces 4 a of the connected, adjacent bars.
[0012] The bars 4 , grooves 5 , and dams 6 can be recognized to form a pattern that is typically repeated in some fashion over the entire grinding face, similar to a tread pattern on a shoe or a tire. An extreme variability in such patterns has been provided in the prior art as would be expected by the analogy to tires and shoes.
[0013] The top surfaces of the grooves in conjunction with the elevation of the top surfaces of the dams provide for flinging the material up onto the top surfaces of the bars where the material is ground. Because refinement results from grinding, it is generally desirable that the top surfaces of the bars that perform this grinding lie in a single plane and are as wide as possible consistent with providing the beneficial effects of the grooves and dams.
[0014] U.S. Pat. No. 5,704,559 to Fröberg et al. represents a different strategy and model than that described above, one which relies on a certain cooperation between the patterns of the two discs.
[0015] A single “bar” as described above in the context of the '559 patent has both high and low bar portions, the terms “high” and “low” being used to describe the overall elevation of the bar portions with respect to a reference plane “P REF ” that is perpendicular to the axis of rotation L.
[0016] Referring to FIGS. 4-6 showing two refining elements 10 and 11 according to the '559 patent, a refining element 10 has a bar 12 a and an opposed refining element 11 has a bar 12 b . The refining element 10 is stationary and the refining element 11 rotates.
[0017] The bar 12 a includes high bar portions 13 that are disposed directly opposite corresponding low bar portions 16 of the bar 12 b ; and the bar 12 b includes high bar portions 15 that are disposed directly opposite corresponding low bar portions 14 of the bar 12 a . The bars 12 a and 12 b are spaced apart to provide a gap 12 through which raw material flows in the direction D FLOW ( FIG. 4 ). The refining element 11 spins in the direction D SPIN ( FIGS. 5-6 ).
[0018] The top surfaces of both the high and low bar portions, 13 - 16 are angled with respect to the reference plane P REF ( FIG. 4 ). Particularly, the surfaces are inclined in the direction of increasing radial distance from the axis of rotation L.
[0019] In addition, transition surfaces connecting the high and low bar portions of the same refining element are also angled from the perpendicular to the reference plane P REF . This feature is particularly asserted to “knead” more softly the material being worked, here referred to as “pulp,” as well as force the pulp to move between the two discs. It is further asserted that this working of the pulp is rendered even more effective due to the inclined top surfaces of the bar portions. It is asserted more generally that the configuration effectively disperses impurities without reducing the “freeness” of the pulp and improves the strength of the pulp.
[0020] Further, the high bar portions 15 on the rotating element 11 have a greater length, in the direction D FLOW , than the high bar portions 13 on the stationary element 10 , and this is asserted to provide a “pump effect” which increases throughput (capacity).
[0021] Whether or not an improvement in pulp strength, impurity distribution or throughput can be realized from the configuration of the '559 patent, it is a disadvantage that opposed bars of the respective refiner elements must be closely toleranced to align with each other. It is also an inherent disadvantage of “kneading” the pulp as taught in the '559 patent that this action breaks down the fibers and requires that a large amount of power be provided to the rotating element. Accordingly, there is a need for a refiner plate that provides for further improvements over the prior art.
SUMMARY
[0022] A refiner plate defines an axis of rotation that further defines variations in azimuth. The refiner plate includes an annular body portion and a plurality of azimuthally spaced-apart elongate bars projecting from the body portion. The bars have top surfaces, each top surface having an elevation that varies, with respect to a reference plane perpendicular to the axis of rotation, as a function of azimuth.
[0023] A disc refiner further defines a direction of rotation of the refiner plate. Preferably, each top surface slopes downwardly in the direction opposite the direction of rotation, to provide for relief. Preferably in addition, each bar has a side intersecting the respective top surface that leans forwardly in the direction of rotation, to provide for attack.
[0024] It is to be understood that this summary is provided as a means of generally determining what follows in the drawings and detailed description and is not intended to limit the scope of the invention. Objects, features and advantages of the invention will be readily understood upon consideration of the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a cross-sectional view of a pair of opposed refiner plates in a typical disc refiner.
[0026] FIG. 2 is a plan view of a broken sector of a typical prior art a refiner plate.
[0027] FIG. 3 is a cross-sectional view of the sector of FIG. 2 , taken along a line 3 - 3 thereof.
[0028] FIG. 4 is a cross-sectional view of a pair of opposed refining elements according to U.S. Pat. No. 5,704,559.
[0029] FIG. 5 is a plan view of a broken sector of one of the refining elements of FIG. 4 .
[0030] FIG. 6 is a plan view of a broken sector of the other refining element of FIG. 4 .
[0031] FIG. 7 is a pictorial view of a pair of refiner plates according to the present invention, with a sector of one of the refiner plates broken to reveal a cutting face.
[0032] FIG. 8 is a plan view of the broken sector of FIG. 7 .
[0033] FIG. 9 is a pictorial view of the broken sector of FIG. 8 .
[0034] FIG. 10 is a cross-sectional view of the sector of FIG. 8 , taken along a line 10 - 10 thereof.
[0035] FIG. 11 is a cross-sectional view like that of FIG. 10 showing two sectors in cooperation.
[0036] FIG. 12 is a cross-sectional view of a sector like that shown in FIG. 10 having a jointed top surface according to a first alternative embodiment.
[0037] FIG. 13 is a cross-sectional view of a sector like that shown in FIG. 10 having a jointed top surface according to a second alternative embodiment.
[0038] FIG. 14 is a side elevation of a generic combination of refiner plates providing for relief according to the invention.
[0039] FIG. 15 is a side elevation of another combination of refiner plates providing for relief according to the invention.
[0040] FIG. 16 is a plan view of a broken sector of one of the refiner plates of FIG. 15 showing a relief in schematic form.
[0041] FIG. 17 is a side elevation of still another combination of refiner plates providing for relief according to the invention.
[0042] FIG. 18 is a plan view of a broken sector of one of the refiner plates of FIG. 17 showing a relief in schematic form.
[0043] FIG. 19 is a side elevation of yet another combination of refiner plates providing for relief according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0044] Reference will now be made in detail to specific preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings.
[0045] Referring to FIG. 7 , a pair of refiner plates 20 and 22 are shown in opposition, as they would be confronting one another in an attrition mill (not shown).
[0046] Relative spinning of the discs about an axis of rotation “L” is provided as known in the art. That is, either one of the discs can be made to spin while the other disc is held stationary, or both of the discs can be made to spin in counter-rotation.
[0047] A sector of the refining plate 22 is shown broken out in FIG. 7 . The removal of this sector reveals a corresponding sector of the plate 20 that is shown in plan, i.e., looking down the axis of rotation L, in FIGS. 8 and 9 where it is referenced as 20 a . A face 21 of the sector 20 a is seen in plan in FIG. 8 and faces upwardly in FIG. 9 . The face 21 exhibits an exemplary pattern of elongate bars 24 , corresponding grooves 26 , and dams 28 . It should be understood that the pattern shown, while being preferred, is not essential to the invention, and that the shape of the grooves and the presence of the dams, while preferably being provided substantially as shown, are also not essential to the invention.
[0048] Moreover, while the bars 24 are essentially linear as viewed in FIG. 8 , bars can have other configurations, particularly curved configurations, as can grooves and dams.
[0049] The sector 20 a as shown spins in the direction “D SPIN .” Material to be refined flows radially over the face 21 from the axis of rotation L in directions “D FLOW .” It should be understood that this material may be any material, but it is typically and preferably wood, and more particularly and preferably, wood chips.
[0050] The direction D SPIN lies along an azimuthal direction “AD,” and the direction D FLOW lies along a perpendicular, radial direction “r.” Both the azimuthal and radial directions are therefore defined with respect to the axis of rotation L, an azimuthal direction being a direction of constant radius, and a radial direction being a direction of constant azimuth.
[0051] While the elongate bars 24 as shown in FIG. 8 are oriented precisely along radial lines r, they may deviate somewhat from such lines, and they will necessarily so deviate if they are curved. In any case, bars are oriented generally in radial directions, meaning that they extend in radial directions at least more so than they extend in azimuthal directions.
[0052] FIG. 10 shows the cross-section indicated in FIG. 8 . The bars 24 project above an annular body portion 19 of the refiner plate. Space between the bars 24 defines grooves 26 . Preferably, adjacent bars viewed in radial cross-sections taken at the same radial distance have the same profile, such as shown.
[0053] A reference plane “P REF ” is shown that lies in the plane of FIG. 8 and is perpendicular to the axis of rotation L (see FIG. 7 ). This reference plane is used to reference elevation. It is to be understood that elevation can vary in radial directions and that there will in general be a lack of perfect perpendicularity of the reference plane and the perpendicular to the axis of rotation, as a result of the face taper discussed above, and that this variation can be ignored for all practical purposes herein.
[0054] The refiner plates 20 and 22 are preferably annular according to standard practice, but would not need to be to function. In any case, the axis of rotation L is an axis of symmetry of the refiner plates.
[0055] According to the invention, it is desired to provide for increased cutting action, decreased grinding action, or both, as compared to prior art disc refiners and refiner plates. To the extent the material to be refined is cut rather than ground, the resulting particles will be exposed to a minimum of damage and therefore have superior mechanical characteristics such as strength. At the same time, the power required to produce particles is dramatically reduced, providing important practical cost savings.
[0056] Continuing with reference to FIG. 10 and as also seen in FIG. 9 , in accord with this intention the bars 24 have top surfaces 24 a that are angled with respect to the reference plane by a relief angle θ, sloping downwardly away from the direction of rotation D SPIN and therefore varying as a function of azimuth. More particularly, in this example, the top surfaces 24 a are planar; they have a maximum elevation “h MAX ” at a leading or “upstream” side 25 of the bar that faces in the direction of spin D SPIN ; and a minimum elevation h MIN at a trailing or “downstream” side 27 of the bar, the elevation decreasing in proportion to the relief angle θ. The relief angle θ is positive in the direction shown in FIG. 10 , indicating the direction of slope.
[0057] FIG. 11 shows a cross-section like that of FIG. 10 of the bars corresponding to the disc 20 and an opposed disc 28 , showing a manner of cooperation between two discs. The opposed disc 28 may have bars with top surfaces that are parallel to the reference plane P REF , i.e., a zero relief angle θ, as in the prior art.
[0058] The disc 28 is assumed to be stationary. An instance of material “M” to be refined is shown that is also, for simplicity, assumed to be stationary. Because the disc 20 spins in the direction D SPIN , the bar 24 , will first impact the material M at a sharp cutting edge “SE” (referenced also in FIG. 9 ) defined by the intersection of the top surface 24 a 1 of the bar 24 1 and the leading side 25 1 of the bar. This edge will be made sharper as the relief angle θ ( FIG. 10 ) is increased and the attack angle α is decreased.
[0059] The sharp edge SE will tend to cut the material M into smaller pieces. As these pieces are transmitted toward the trailing side 27 1 of the bar, the greater spacing between the top surface 24 a 1 and the top surface 28 a 2 of the opposing bar 28 2 of the disc 28 reduces the amount of grinding that would otherwise occur. In effect, to a substantial extent, grinding has been replaced with cutting.
[0060] In that regard, the top surfaces 24 a define a face “F” of the refiner plate that corresponds to the “grinding face” described above in connection with the prior art. The term “grinding face” will be used herein to describe the face “F” and the like herein according to the present invention for consistency with prior art usage and definition of terms, but it should be understood that grinding action provided by the face “F” can be greatly reduced, or essentially eliminated according to the invention and to this extent the term is a misnomer.
[0061] The relief angle is preferably in the range 1<θ<30 degrees measured with respect to the reference plane, is more preferably in the range 2<θ<10 degrees, and is most preferably 6 +/−1 degrees, or about 6 degrees.
[0062] A non-zero relief angle both increases cutting action and decreases grinding action, the more so with increased relief angle θ. However, there is a limit to the amount of relief that is desirable for two reasons. First, the strength of the cutting edge SE is reduced with greater relief. Second, the top surface if sloped too much allows the material M to fall from the trailing side 27 to a lower elevation where it is not well positioned to be cut by the cutting edge SE of the next bar.
[0063] Returning to FIG. 10 , the leading side 25 of the bars is also preferably angled from the perpendicular to the reference plane, leaning forwardly into the direction of rotation, to define an attack angle α. The attack angle α is preferably in the range 45<α<90 degrees measured with respect to the reference plane, and is most preferably in the range 85+0/−10 degrees.
[0064] The attack angle provides for attack as known in the art, though it should be noted that a smaller attack angle provides for a greater amount of attack. Greater attack contributes to increasing cutting action, by further sharpening the cutting edge SE.
[0065] FIGS. 12 and 13 show two illustrative alternative embodiments of bars according to the present invention that employ jointed top surfaces. FIG. 12 shows a jointed top surface 34 a for a bar 34 projecting from a body portion 39 of a refiner plate 38 . The top surface 34 a has two planer portions 34 a 1 and 34 a 2 . The portion 34 a 1 is leading or upstream with respect to the direction of rotation D SPIN , relative to the portion 34 a 2 , which is trailing or downstream. The upstream portion 34 a 1 is provided with a non-zero relief angle θ and the downstream portion 34 a 2 is provided with a zero relief angle. The relief angle of the upstream portion 34 a 1 can be substantially greater than that described above and still provide for the essentially the same overall elevation of the bar. This configuration maximizes the cutting action while minimizing the effect on the grooves and dams.
[0066] The relief angle can be made larger than in the bars 24 as a consequence of adjusting widths “W” of the portions, namely an upstream width W 1 and downstream width W 2 of the upstream and downstream portions 34 a 1 and 34 a 2 , as will be readily appreciated by persons of ordinary mechanical skill.
[0067] FIG. 13 shows another jointed top surface 44 a for a bar 44 projecting from a body portion 49 of a refiner plate 48 . The bar 44 has an upstream portion 44 a , and a downstream portion 44 a 2 . In this case, which is inverse to that described immediately above, the downstream portion 44 a 2 is provided with a non-zero relief angle and the upstream portion 44 a 1 has a zero relief angle. This provides for some additional grinding and less cutting; however, it may be desirable to maximize the life of the refiner plate. That is, the refiner plate may be renewed by the process known as “jointing” by grinding or facing the upstream portion 44 a 1 . Widths W of the portions, namely an upstream width W 1 and downstream width W 2 of the upstream and downstream portions 44 a 1 and 44 a 2 respectively, may be adjusted to provide a desired trade-off.
[0068] A refiner plate having bars defining a particular relief angle, or in the case of the jointed surface embodiments a particular combination of relief angles, may be and according to the invention often are preferably paired with an opposed refiner plate having bars defining a different relief angle or set of relief angles, as next illustrated in connection with FIGS. 14-16 .
[0069] FIG. 14 shows a generic pair of opposed refiner plates in side elevation. One of the plates 50 has a “grinding face” 53 with bars (not shown) all having a “relief” referenced as “R 50 ,” i.e., a relief angle that defines the hidden line shown. The other plate 60 has a “grinding face” 63 that similarly has a relief “R 60 .” Tests have indicated that it is preferable to provide that the relief R 50 is not equal to the relief R 60 . For example, the relief R 50 may be 6° while the relief R 60 may be zero. Testing of this particular combination shows a very significant reduction in power consumption; on the other hand, the quality of the particles produced is not optimum in that there is a tendency to produce particles that are over-size. This trade off will be advantageous, however, where power consumption considerations are paramount and particle quality of is of lesser concern, such as in pre-processing or pre-refining operations.
[0070] FIG. 15 shows the refiner plate 50 of FIG. 14 paired with an alternative refiner plate 70 according to the invention. The refiner plate 70 has bars (not shown) having top surfaces comprising multiple planar segments at varying elevations. More particularly, the plate 70 in this example provides a set of two reliefs R 71 and R 72 that increase with radial distance r from the axis of rotation L. Referring in addition to FIG. 16 showing schematically a sector of the refiner plate 70 in plan, the relief R 71 is applied to a radially innermost portion of the plate 70 defined between radial distances “r 1 ” and “r 2 ” referenced from the axis of rotation L. The relief R 72 is then applied to the remaining (in this case), radially outermost portion of the plate between the radial distances r 2 and “r 3 .” A single bar may extend over both the innermost and outermost portions and therefore have two reliefs, or separated bars aligned but spaced apart in the radial direction such as shown in FIG. 8 can be provided; where such bars are disposed within the innermost region they may have one relief R 71 , and where such bars are disposed within the outermost region they may have the other relief R 72 .
[0071] Test results for the two refiner plates 50 and 70 , where the relief R 50 is 6° while the reliefs R 71 and R 72 are zero and 6°, respectively, show both high quality particles and a power reduction of 10-15% over the prior art.
[0072] FIGS. 17-18 illustrate another refiner plate 80 having bars (not shown) with top surfaces comprising multiple planar segments at varying elevations. Particularly, the plate 80 provides for four different reliefs R 81 , R 82 , R 83 , and R 84 that increase with radial distance r from the axis of rotation L. For example, the reliefs R 81-84 can be zero degrees, 2°, 4°, and 6°, progressing from relatively radially inner portions to relatively radially outer portions of the refiner plate.
[0073] FIG. 19 shows yet another alternative refiner plate 90 defining a relief R 90 that is actually a continuum of relief angles that continuously vary with distance r, preferably increasing with radial distance as shown. The top surfaces of the bars in this example will be helical rather than planar. And helical top surfaces may be combined with planar top surfaces such as shown in FIG. 16 in any combination.
[0074] Such a manner of providing for relief may be combined with the manner shown in the embodiment of FIG. 16 .
[0075] It is to be understood that, while a specific refiner plate has been shown and described as preferred, other configurations and methods could be utilized, in addition to those already mentioned, without departing from the principles of the invention. The terms “refiner plate,” “disc refiner” and “bar” are terms art and are therefore intended to have the specific meanings ordinarily attributed to them by persons of ordinary skill.
[0076] 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 to exclude 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. | A refiner plate defines an axis of rotation that further defines variations in azimuth. The refiner plate includes an annular body portion and a plurality of azimuthally spaced-apart elongate bars projecting from the body portion. The bars have top surfaces having elevations that vary as functions of azimuth. A disc refiner further defines a direction of rotation of the refiner plate. Preferably, each top surface slopes downwardly in the direction opposite the direction of rotation, to provide for relief. Preferably in addition, each bar has a side intersecting the respective top surface that leans forwardly in the direction of rotation, to provide for attack. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
The present application claims the benefit of U.S. Provisional Application 60/156,814, filed Sep. 29, 1999.
FIELD OF THE INVENTION
The present invention relates generally to the field of electronic commerce. More particularly, the present invention relates to a method of and system for processing transactions, such as order entry and execution, and inquiries, such as order status and account information inquiries. The present invention provides increased availability to customers, increased reliability of execution, and increased auditability of the books and records of a firm.
DESCRIPTION OF THE PRIOR ART
Currently, a substantial amount of business is conducted using electronic commerce. There have been several phases in the development of electronic commerce. In each of these phases, more flexibility has been added to the way systems are constructed and the way systems perform has changed radically for both businesses and customers.
Prior to the development of the Internet, the typical structure of systems was to build a set of initially monolithic back-end servers, and then add new services in front of these to communicate with clients. A three-tier model of computing evolved, with an intermediate application server that addressed the problems of manageability and scalability as the number of clients grew. In practice, these systems were never as simple as the architectural diagrams made them out to be. They generated islands of computing, each with incompatible services and clusters of inaccessible data. This led to a spider's web of interconnected activity and ensured that little problems at one end of the network became large problems throughout the network. A new class of software was developed to integrate heterogeneous services.
True electronic commerce began with Web sites, brochures, and manual order entry. Initially, the Web was treated as just another client. There was a class of simple application Web servers that created its own data and used its own protocols. The simplest application to write were read-only brochure and e-mail order entry systems, which allowed more efficient distribution of information. They did not, however, have a significant impact on the customer experience and did not change consumer behavior. Competition among early adopters centered around who had the most seductive graphics and interactive content. These systems typically were flashy front-ends attached to unchanged back-end systems. Much of the real work was still done by people.
For many industries, the first generation model created little customer value. This was true for the stock brokerage industry. The first generation companies did not deliver real-time products electronically. The brokerage industry operates in a real-time world where prices change continuously and transaction completion requires integration with market data providers, trading venues, and settlement agencies. This mandates the integration of multiple inputs, processes and outputs.
In the second generation of electronic commerce, the entire customer interaction, from entering an order to delivering the end result, is done online. The customer becomes acutely aware of the underlying frailties of the assorted systems that perform the subprocesses of the order. The design of these systems reflects to customers the status of the respective processes.
Prior to the Internet, old-line financial institutions monopolized access to information. They turned the resulting customer ignorance about products and performance into profits. Access to information has allowed customers to disintermideate commissioned brokers as information distributors and take control of their financial lives. The Internet has empowered customers with more information and choices. The Internet economy has shifted the balance of power to customers.
Current electronic commerce systems have two salient characteristics. First, they are divided primarily along business and application ownership lines. The system and application boundaries are determined exclusively by the organization that owns the application or service. The second characteristic is that they are built with data control residing in physical control. Data belongs to a particular business and that business determines its location, which has forced accessing applications to choose between deployment on that same platform or inferior performance. The combination of these two factors has led to a tightly coupled, monolithic, centralized model with a classic two- or three-tiered client/server architecture.
Today, almost all corporate data is available from only one, very large system, and clients must submit requests to that system to both update and read data. The availability of the central system determines the availability of the entire system. The central system holds all the corporate data and the access to it. The present monolithic system is limited both in terms of availability and scalability. The availability of the central system determines the availability of the entire system. The central system holds all the corporate data and controls the access to it. The scalability of the total system is determined by the scalability of the central system.
Currently existing electronic commerce systems allow for continuously available, but not real-time, status of orders, or continuously available order entry without rapid electronic delivery from open markets. However, no current system maintains a continuously available, scalable order entry system for a business that has rapid electronic delivery from open markets together with real-time order status.
SUMMARY OF THE INVENTION
The present invention provides a method of and system for conducting electronic commerce. In the system of the present invention, an enterprise is segmented into a single firm side system, and multiple customer facing and street side systems. The firm side system maintains a single system of record for the enterprise. The firm side system settles orders, maintains customer account balances, and generally maintains the books and records of the enterprise. The firm side system maintains authoritative storage for the books and records of the enterprise. The firm side system has read-only access to data records replicated from the customer facing and street side systems. The system replicates data from the authoritative data storage of the firm side system to read-only storage associated with the customer facing systems and the street side systems.
The customer facing systems provide an interface between the enterprise and the customer for order entry, order status, and account and market information. Each customer facing system has associated therewith authoritative data storage and read-only data storage. The customer facing system writes to its associated authoritative data storage. The system replicates data records written to the authoritative data storage of any one of the customer facing systems to the authoritative data storage of each of the other customer facing systems. The system also replicates data records written the authoritative data storage of any one of the customer facing systems to the read-only data storage of the firm side system.
The street side systems are in communication with the customer facing systems. The street side systems provide an interface between the enterprise and various markets. Each street side system has associated therewith authoritative data storage that is written to by the street side system and read-only data storage. The system replicates data records written to the authoritative data storage of any one of the street side systems to the authoritative data storage of each of the other street side systems and to the read-only data storage of each of the customer facing systems and firm side system.
The system of the present invention writes and replicates data records to the authoritative data storage of the customer facing systems and the street side systems using an insert only/insert always strategy, without regard referential integrity and data normalization. Each data record is written or replicated as separate line in the data storage. The inquiry application in the customer facing system aggregates the data records to determine the true state of a transaction.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a system according to the present invention.
FIG. 2 is a diagram of data management and replication according to the present invention.
FIG. 3 is a pictorial view illustrating a transaction record format according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, and first to FIG. 1 , a system according to the present invention is designated generally by the numeral 11 . According to the present invention, an enterprise is segmented into a customer facing side 13 , a firm side 15 , and a street side 17 . The system of the present invention finds application to a retail brokerage enterprise.
Customer side 13 is implemented in a plurality of customer side utilities 19 . Each customer side utility 19 includes applications for interacting with customers or customers' agents. The applications of the customer side utility 19 include order entry applications and query applications for providing information such as order status, balances, positions, market data, and the like. Customer side utilities 19 are adapted to respond to asynchronous requests from customers received through gateways indicated generally at 21 .
Customers can communicate with customer side utilities 19 using customer PC's connected to the Internet using standard Web browser-enabled applications. Customers may also communicate asynchronous requests to customer side utilities 19 through the public switch telephone network using telephones 25 . Gateways 21 may communicate with telephones 25 through voice response units or DTMF-enabled applications. Additionally, customers may communicate with customer side utilities 19 through intermediary retail sales representatives or brokers using personal computers 27 running Web based applications, terminal emulator programs, or the like.
The street side of the system of the present invention is implemented in a plurality of street side utilities 29 . In the retail brokerage example of the present invention, street side utilities 29 provide all functionality necessary for executing customer orders. Thus, each street side utility 29 is adapted to communicate asynchronously and diversely through a network indicated generally at 31 with exchanges, indicated generally at 33 , mutual fund companies, indicated generally at 35 , and the like.
According to the present invention, the firm side of the enterprise is implemented in a firm side utility 37 . Firm side utility 37 has access to the authoritative source of data comprising the books and records of the enterprise. Among other things, firm side utility 37 includes applications for settling orders, updating balances, and the like. Firm side utility 37 is adapted to perform end-of-day accounting, bulk processing, and it comprises the source of business intelligence for the enterprise. In the preferred embodiment, firm side utility 37 is implemented using a Geographically Distributed Parallel Sysplex (GDPS) infrastructure available from International Business Machines Corporation. The GDPS system provides failover redundancy to maintain the mission critical records of the firm.
Customer side utilities 19 , firm side utility 15 , and street side utilities 17 are interconnected for asynchronous communication with each other by a network indicated generally at 39 . A customer request received at a gateway 21 is routed to a customer side utility. In the case of an order, the request is forwarded to a street side utility 29 for execution.
Referring now to FIG. 2 , there is shown a block diagram of the data architecture system 11 . Each customer side utility 19 has associated therewith customer side writable data storage 41 . Customer side writable data 41 has a limited set of data that is updated only by a customer side utility 19 . Customer side writable data is authoritative for customer side utilities 19 .
According to the present invention, whenever a customer side utility 19 writes a data record to its associated customer side writable data 41 , the system of the present invention replicates that data record to each of the other customer side writable data storage systems 41 .
Data records written to customer side writable data 41 are also replicated to customer side replicated data 43 , which is accessible by firm side utility 37 . Firm side utility 37 uses customer side replicated data 43 in its work to settle orders, update balances, and the like. Firm side utility 37 uses customer side replicated data, and other data to settle orders, update balances, and the like. Firm side utility 37 writes the authoritative data of the firm to a single firm writable data storage 45 . Firm writable data 45 is replicated to firm replicated data 47 associated with each customer side utility 19 . Firm replicated data 47 is read-only by customer side utilities 19 . Customer side utilities 19 access firm replicated data 47 , together with customer side writable data 41 in order to respond to customer inquiries.
Each street side utility 29 has associated therewith street side writable data storage 49 . Street side writable data 49 is written to by street side utilities 29 and it comprises the authoritative data for street side utilities 29 . Whenever a data record is written to street side writable data 49 , that data record is replicated to each street side writable data 49 . Additionally, data records written to street side writable data 49 are replicated to street side replicated data 51 associated with firm side utility 37 and street side replicated data 53 associated with customer side utilities 19 . Basic street side data associated with order status and execution is made available immediately through replication to customer side utilities 19 . Additionally, firm side writable data 45 is replicated to firm replicated data 55 associated with street side utilities 29 .
FIG. 3 illustrates the format of a transaction data record according to the present invention. Each transaction record includes a transaction identifier or number field 71 . Each customer side utility 19 has a unique transaction numbering set or scheme so that the same transaction number is not assigned to more than one transaction. When a customer side utility 19 receives a transaction request from a customer, the receiving customer side utility assigns a transaction number to the transaction. All data records relating to the transaction are identified by the transaction number.
A transaction data record also includes a transaction type field 73 , which identifies the type of transaction. In the retail securities environment, examples of transaction types include buy and sell orders. Those skilled in the art will recognize other transaction types, such as limit orders and the like. The status of the transaction is reflected in a status field 75 . In the retail securities environment, for purchase and sale transactions, the status may be placed, canceled, and filled. Status field 75 includes a timestamp, which indicates the time at which the order was placed, canceled, or filled. The timestamp information is used to resolve conflicts. For example an order may be nearly simultaneously canceled and filled. The status change with the earlier timestamp will take precedence over the conflicting status change.
Other information concerning the transaction or status change is contained in an other information field 77 . Examples of other information includes the number of shares, the company, and the transaction price.
According to the present invention, data records are written to customer side writable data 41 using an insert-only/insert-always strategy, as opposed to an update strategy, without regard to referential integrity or data normalization. More specifically, each data record is written as a separate row in a database rather than as an update.
The problem with an update strategy is that there must be a record to update. For example, when an order is placed, an order record is created. Whenever the order's state changes, the order record gets updated. However, in a distributed environment, with asynchronous linkages among systems, state changes may not occur in the anticipated order. An update event may occur or be received at a system without a record to change. The customer may gain access to the system through any of the customer side utilities 19 . Accordingly, the customer may not interact with the same customer side utility on each access. Since transactions are processed and data records are replicated at finite speed, there are certain latencies inherent in the system. Also, there may be periodic failures or interruptions in links over which internal messages are transmitted or data is replicated. Thus, the data associated with a particular customer side utility 19 may not be complete or current.
Additionally, in current systems, a record that does not exist cannot be changed. Databases enforce constraints of this type through referential integrity. According to referential integrity, there is a relationship between two rows of a database that refer to each other. If the required relationship refers to something that does not exist, the database will not allow the update to occur. According to the present invention, each data record is inserted without regard to referential integrity.
Normalization aims at eliminating duplication of data. Instead of keeping the same data in multiple locations, in current systems the data is defined in one place, then it is referred to from any other place that is related to it. If the system of the present invention used normalized data in the replicated systems, then updates to an order would refer to the original order rather than duplicate that information. Because updates can arrive at different rates, the possibility exists that the original order information may not be there to refer to. Therefore instead of normalizing data, the system of the present invention duplicates information so that each data record carries with it essential information about the order. Thus, the customer side utility 19 can display the order information that it has no matter in which order the data records relating to the order arrive.
According to the present invention, the inquiry applications of customer side utilities 19 contain logic for aggregating the data records with respect to a single transaction to determine the true or best estimate of the state of the transaction. For example, if the data storage associated with a particular customer side utility contains a data record indicating that an order has been filled, but no data record indicating that the order has been placed, the customer side utility will report that the order has been filled. Similarly, if the data storage contains records indicating that an order has been both filled and canceled, the customer side utility will report that the order has been filled or canceled based upon which event occurred earlier.
It may be seen that the system of the present invention provides improved availability and ensures scalability while retaining flexibility. Because the system of the present invention uses smaller components, and asynchronous links to couple them, the system of the present invention is split into simpler parts that will each be more reliable. In addition, the customer side utilities 19 are continuously available by replication and load balancing among them. Customer side utilities 29 communicate with other parties by diverse routing so that a failure of one system does not stop the flow requests and responses.
Customer side utilities 19 and street side utilities 29 are independently scalable. Because customer side utilities 19 are replicated for availability, they may be scaled by further replicating more systems. The load on the firm side utility 37 is reduced because the inquiry load from customers and the communication with other parties is removed. Therefore, the size of the firm side utility system 37 can be reduced to a sustainable point on the technology curve. The street side systems 29 can be scaled independently and replicated just like the customer side utility systems 19 .
From the foregoing, it may be seen that the present invention provides a continuously available, scalable order entry system for a business that has rapid electronic delivery from open markets together with real-time order status. The customer-facing and street-facing parts of the enterprise may be scaled independently to meet increasing volumes of transactions and inquiries. Order state data are replicated across the system so that real-time information is available to the customers.
The present invention has been illustrated and described with respect to presently preferred embodiments. Those skilled in the art will recognize alternative embodiments, given the benefit to the foregoing disclosure. Accordingly, the foregoing disclosure is intended for purposes of illustration rather than limitation. | A method of and system for conducting electronic commerce segments an enterprise is segmented into a single firm side system, and multiple customer facing and street side systems. The firm side system maintains a single system of record for the enterprise. The customer facing systems provide an interface between the enterprise and the customer. The street side systems are in communication with the customer facing systems. The street side systems provide an interface between the enterprise and various markets. | 6 |
RELATED APPLICATIONS
The present invention claims priority from Korean patent application number 10-2010-0086907, filed in the Korean Patent Office on Sep. 6, 2010, which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
This invention relates to a hinge assembly for a steam cleaner capable of pivoting in front/rear (X) and left/right (Y) directions, and more particularly to a hinge assembly for a steam cleaner capable of being adjusted automatically in a straight direction after a swerving force is removed, when a base assembly was swerved while locking automatically a left/right directional pivoting action.
BACKGROUND OF THE INVENTION
In general, a hinge assembly used for a steam cleaner can be pivoted in front/rear and left/right directions. In this case, a front/rear directional pivoting action aids to push or pull a push stick assembly in slightly laid state, and a left/right directional pivoting action allows a base assembly with a pad to be swerved in a degree when it bumps against a corner or other things (for example, table's leg).
When the steam cleaner is not used, the push stick assembly is stood perpendicularly or in close to the perpendicular, and locked with a fixing member such that it cannot be pivoted in front/rear directions.
The fixing member can lock said front/rear directional pivoting action. If the fixing member is used, it is releasably fitted in a base assembly.
Hence, the fixing member should be unlocked or locked each time when the steam cleaner is used or not used. This work is very annoying.
In particular, the fixing member is unlocked during the use of steam cleaner. Therefore, since the push stick assembly tends to swerve in left/right directions when pushing or pulling it in a straight direction, a user may feel inconvenient.
In addition, since the left/right directional pivoting action is performed only along a left and right pivoting center axis, when base assembly 100 is swerved at the angle of θ to push stick assembly 300 as shown in FIG. 11 , the base assembly is maintained at θ angle even if the push stick assembly is pulled back. Therefore, a user has to swerve base assembly 100 or push stick assembly 300 such that they are in line, and this work is very annoying.
Moreover, a conventional steam cleaner is primarily used to clean a wooden floor or a carpet (in some case, there is a tray to prevent a pad attachment protrusion (so-called Velcro) from being caught by a carpet when using a steam cleaner). Indeed, when cleaning floors of hard materials such as tile using such steam cleaner, smudged stains may not be cleanly removed since a pad-type cleaning cloth is only used, but a brush is not used.
SUMMARY OF THE INVENTION
This invention has been invented to solve the aforementioned problem. Therefore, the object of this invention is to provide a hinge assembly for a steam cleaner, characterized in that a left/right directional pivoting action of the steam cleaner is locked at ordinary times, but the steam cleaner is automatically pivoted in left/right directions when any external force is applied.
In order to achieve the aforementioned object, according to Claim 1 of this invention, it is provided a hinge assembly for a steam cleaner comprising:
a first member fitted in a base assembly and having a front and rear pivoting center axis which supports to be pivoted in front/rear directions; a second member fitted in a push stick assembly; a left and right pivoting center axis member having a left and right pivoting center axis by which the second member is supported to be pivoted in left/right directions relative to the first member; and an eccentric member fitted in parallel eccentrically to the left and right pivoting center axis;
wherein the left/right directional pivoting action of the steam cleaner is locked by the eccentric member when the first and second members are in line in a longitudinal direction, and the left/right directional pivoting action is allowed when an external force is applied to the locked state, and the locked state is unlocked.
According to Claim 2 of this invention, it is provided a hinge assembly for a steam cleaner:
wherein the eccentric member comprises a locking hole formed in the first member; a left and right pivotable groove connected to the locking hole; a locking piece fitted slidably in the second member; and an elastic portion imparting elasticity to the locking piece.
According to this constitution, the locking piece is locked in the locking hole at ordinary times, but the locking piece leaves for the left and right pivotable groove when an external force is applied, to allow the left/right directional pivoting action, thereby enabling an automatic lock and unlock.
According to Claim 3 of this invention, it is provided a hinge assembly for a steam cleaner:
wherein the left and right pivotable groove may preferably be inclined downwardly toward the locking hole.
According to this constitution, when the external force by which the base assembly is pivoted in left/right directions is removed (i.e., pulling back), the base assembly is automatically swerved in a straight direction instantly the locking piece is automatically guided to the locking hole and locked therein.
According to Claim 4 of this invention, it is provided a hinge assembly for a steam cleaner comprising:
a first member fitted in a base assembly and having a left and right pivoting center axis which supports to be pivoted in left/right directions; a second member fitted in a push stick assembly; a front and rear pivoting center axis member having a front and rear pivoting center axis by which the second member is supported to be pivoted in front/rear directions relative to the first member; and an eccentric member fitted in parallel eccentrically to the left and right pivoting center axis;
wherein the front/rear directional pivoting action of the steam cleaner is locked by the eccentric member when the first and second member are in line in a longitudinal direction, and the front/rear directional pivoting action is allowed when an external force is applied to the locked state, and the locked state is unlocked.
As can be clearly seen from the above description, a preferable embodiment of this invention will exhibit the following effect.
The hinge assembly for a steam cleaner according to this invention has the eccentric member which is coupled and fitted in parallel eccentrically to the left and right pivoting center axis. Hence, when the first and second members are in line in a longitudinal direction, the left/right directional pivoting action is locked, and it is very convenient in cases such as pushing the steam cleaner in front/rear directions or keeping it in standing. When an external force is applied to the locked state, the left/right directional pivoting action is automatically unlocked and allowed such that the base assembly can be swerved in a degree when it bumps an obstruction, and it is very convenient during the use of steam cleaner.
Further, since the left and right pivotable groove is inclined downwardly toward the locking hole, when the external force by which the base assembly is pivoted in left/right directions is removed (i.e., pulling back), the base assembly is automatically swerved in a straight direction instantly the locking piece is automatically guided to the locking hole and locked therein. Hence, since a user doesn't need to swerve intentionally the push stick assembly, the steam cleaner can be conveniently used.
BRIEF DESCRIPTION OF THE INVENTION
FIG. 1 is a projective view of a steam cleaner according to a preferable embodiment of this invention.
FIG. 2 is a projective view showing a sheet cover removed from a hinge assembly of FIG. 1 .
FIG. 3 is a projective view showing a spring and locking piece removed from FIG. 2 .
FIG. 4 is a projective view showing a left and right pivoting center axis member removed from FIG. 3 .
FIGS. 5 a and 5 b are front and cross-sectional views showing a locked eccentric member.
FIGS. 6 a and 6 b are front and cross-sectional views showing an eccentric member pivoted in a right direction.
FIGS. 7 a and 7 b are front and cross-sectional views showing an eccentric member pivoted in a left direction.
FIGS. 8 and 9 are top and bottom projective views showing a brush tray removed from FIG. 1 .
FIG. 10 is a schematic view showing that a base assembly is automatically adjusted in a straight direction when pulling back the swerved base assembly according to this invention.
FIG. 11 is a schematic view showing that a base assembly is still swerved when pulling back the swerved base assembly according to the conventional art.
DETAILED DESCRIPTION OF THE INVENTION
In the following, preferable embodiments according to this invention will be described with reference to the accompanying drawings.
FIG. 1 is a projective view of a steam cleaner according to a preferable embodiment of this invention; FIG. 2 is a projective view showing a sheet cover removed from a hinge assembly of FIG. 1 ; FIG. 3 is a projective view showing a spring and locking piece removed from FIG. 2 ; FIG. 4 is a projective view showing a left and right pivoting center axis member removed from FIG. 3 ; FIGS. 5 a and 5 b are front and cross-sectional views showing a locked eccentric member; FIGS. 6 a and 6 b are front and cross-sectional views showing an eccentric member pivoted in a right direction; FIGS. 7 a and 7 b are front and cross-sectional views showing an eccentric member pivoted in a left direction; FIGS. 8 and 9 are top and bottom projective views showing a brush tray removed from FIG. 1 ; FIG. 10 is a schematic view showing that a base assembly is automatically adjusted in a straight direction when pulling back the swerved base assembly according to this invention.
As shown in FIGS. 1 to 4 , the steam cleaner according to a preferable embodiment of this invention comprises base assembly 100 , push stick assembly 300 , and hinge assembly 500 by which base assembly 100 is connected to push stick assembly 300 .
Base assembly 100 comprises a body having upper case 110 and lower case 120 , steam jet 130 formed on bottom plate 121 of lower case 120 , and pad attachment protrusion 140 molded on the lower surface of bottom plate 121 in front and rear portions of steam jet 130 .
Push stick assembly 300 comprises housing 310 in which a steam-generating member (non shown) for supplying steam to steam jet 130 is mounted, and a handle rod (not shown) fitted on the top end of housing 310 .
Hinge assembly 500 comprises first member 510 fitted in base assembly 100 , second member 530 fitted in push stick assembly 300 , left and right pivoting center axis member 550 by which first member 510 is connected to second member 530 , and eccentric member 570 fitted in parallel eccentrically to left and right pivoting center axis member 550 , as major components.
First member 510 has first tube 511 , front and rear pivoting center axis 513 formed protrusively at the lower left and right sides of first tube 511 , and a pair of first arms 515 protruded upwardly at the upper front and rear portions of first tube 511 .
Front and rear pivoting center axis 513 is a centric support axis allowing a pivot about X axis in front and rear directions, and supports the coupled upper case 110 and lower case 120 .
Front and rear pivoting center axis 513 is fitted within base assembly 100 . When a steam clear is kept in standing, base assembly 100 and first tube 511 are interlocked such that they cannot be pivoted backward (in use, if a little force is applied backward, the locked state is unlocked).
Front and rear pivoting center axis 513 may be integrally formed with first tube 511 by an injection molding method, or it may be coupled with first tube 511 as an separate part.
Second member 530 has second tube 531 , and a pair of second arms 535 protruded downwardly at the upper front and rear portions of second tube 531 .
Second arm 535 is placed on the outer surface of first arm 515 and telescoped on first arm 515 . The first and second arms are supported by left and right pivoting center axis member 550 such that they can be pivoted about Y axis in left/right directions.
Left and right pivoting center axis member 550 has left and right pivoting center axis 551 , flange 553 formed at the rear end of left and right pivoting center axis 551 , and screw 555 coupled at the front end of left and right pivoting center axis 551 .
When left and right pivoting center axis 551 is telescoped into first arm 515 from the inner side to the outer side of first arm 515 , flange 553 is stopped at the inner side of first arm 515 , and coupled using screw 555 at the front end of left and right pivoting center axis 551 inserted through first arm 515 and second arm 535 .
According to this constitution, tube 150 for supplying steam passes through first and second members 510 and 530 , and is connected to steam jet 130 of base assembly 100 . That is, no obstruction (for example, left and right and/or front and rear pivoting center axis, eccentric member, and the like) is inside first and second members 510 and 530 .
Eccentric member 570 is spaced-apart at an eccentric distance (e) above left and right pivoting center axis 551 . Hence, when first and second members 510 and 530 are in line in a longitudinal direction (see FIGS. 5 a and 5 b ), a left/right directional pivoting action is locked. In addition, when an external force is applied to the locked state, the left/right directional pivoting action is automatically unlocked and allowed (see FIGS. 6 a , 6 b , 7 a and 7 b ). These actions are automatically adjusted.
Eccentric member 570 comprises locking hole 571 formed in first member 510 ; left and right pivotable groove 573 connected to locking hole 571 ; locking piece 575 fitted slidably in second member 530 ; and elastic portion 577 imparting elasticity to locking piece 575 .
Flange 576 is formed at the front side of locking piece 575 . The flange obstructs the locking piece, and acts as one side's sheet for spring 578 as described below.
Elastic portion 577 has spring 578 , and sheet cover 579 , and the sheet cover acts as the other side's sheet for spring 578 .
In addition, left and right pivotable groove 573 may preferably be inclined (at a angle) downwardly toward locking hole 571 .
Eccentric member 570 as described above will exhibit functions and effects as follows:
First, as shown in FIGS. 5 a and 5 b , when a steam cleaner is kept in standing, or pushed or pulled in a straight direction (i.e., the first and second members are in line in a longitudinal direction), locking piece 575 is inserted in locking hole 571 , and a left/right directional pivoting action is locked.
However, if base assembly 100 bumps against an obstruction during the use of steam cleaner, the base assembly is swerved at θ angle (see FIG. 10 ), in a right direction as shown in FIGS. 6 a and 6 b , or a left direction as shown in FIGS. 7 a and 7 b.
That is, base assembly 100 and first member 510 is simultaneously swerved to position locking piece 575 into left and right pivotable groove 573 .
Thus, a need of locking or unlocking a fixing member is omitted, and the locked state is automatically unlocked by eccentric member 570 . This makes the use of steam cleaner very convenient.
Then, if the counter force from the obstruction is removed by pulling back the steam cleaner in the swerved state, locking piece 575 positioned in left and right pivotable groove 573 inclined tends to return to locking hole 571 , which was its original position, resulting in enabling an automatic lock.
By this automatic locking action, a left/right directional pivoting action is locked, and base assembly 100 is positioned in a straight direction. Hence, a user doesn't need to swerve base assembly 100 or push stick assembly 300 .
In case of the prior art, a user should swerve base assembly 100 in a right position, and then push it in front/rear directions, since it is not easy to push base assembly 100 in a swerved state. According to this invention, this annoying work may be omitted.
Preferably, tray 170 with brush 177 may be additionally fitted, as shown in FIGS. 9 and 10 . The brush may be used to rub a floor such as tile.
Tray 170 may be removed when cleaning a wooden floor using a steam cleaner, and it may be fitted in base assembly 100 when cleaning a badly stained concrete or tile floor using the steam cleaner.
Tray 170 has tray plate 170 a , a tray frame with rim 170 b protruded slightly upwardly around tray plate 170 a , steam jet through-hole 172 formed in tray plate 170 a , and brush 177 formed on the lower surface of tray plate 170 a.
Steam jet through-hole 172 may preferably be placed below steam jet 130 .
Further, the tray frame with brush 177 covers pad attachment protrusion 140 , and thus it acts to prevent damages due to friction with a rigid floor.
Tray 170 is removably attached to base assembly 100 using removable members.
The removable members include front removable piece 171 and rear removable pieces 173 and 174 .
Front removable piece 171 is formed protrusively at the front left and right sides of the tray frame, exactly from the front left and right sides of rim 170 b toward the rear. When it is coupled with upper case 110 , it acts to press and hold the front top surface of upper case 110 .
Rear removable pieces 173 and 174 has rear removable engaged piece 173 protruded upwardly at the rear left and right sides of the tray frame, exactly the rear left and right sides of rim 170 b toward the upside, and rear removable and engaged stopping piece 174 formed at the rear side of upper case 110 and engaged with rear removable and engaged protruding piece 173 .
Preferably, rear removable and engaged protruding piece 173 has elastic property, and it may be bended backward until it is engaged with rear removable and engaged stopping piece 174 . That is, rear removable and engaged protruding piece 173 acts to press and hold upper case 110 such that the upper case is not raised upwardly.
By using these removable members, rear removable and engaged stopping piece 174 is engaged with rear removable and engaged protruding piece 173 while piece 174 pushes back slightly the piece 173 and falls down, and their coupling is completed, by a series of operations that base assembly 100 is first slightly bended forward, is coupled with front removable piece 171 , and then is stood perpendicularly.
In the state that two pieces is coupled, tray 170 may be removed by lifting up push stick assembly 300 while pressing plate 175 using foot. By this work, rear removable and engaged stopping piece 174 is pivoted about front removable piece 171 and is unengaged with rear removable and engaged protruding piece 173 . Then, tray 170 is completely removed from the base member by drawing piece 174 out of piece 173 .
Thus, tray 170 may be simply coupled with the base assembly by the mechanism that the tray is surrounded and pressed at the front side and it is pressed from above at the rear side. Once the tray is coupled with the base assembly, since the tray may be removed only when a physical force is applied, it tray may be stably used (the base assembly with the tray attached has a double structure by which the tray should be drawn out upwardly at the rear side, and in a sharp angle direction at the front side. Therefore, since the tray is held in the front side when pulling a steam cleaner, and is held in the rear side when pushing it, the tray cannot easily be removed from the base assembly)
While this invention has been shown and described in connection with the preferably embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.
For example, contrary to the embodiment described above, it will be appreciated that an eccentric member may be fitted in a hinge assembly having a first member with a left and right pivoting center axis and a second member with a front and rear pivoting center axis.
The hinge assembly according to this invention may be applied to any article having front/rear and left/right directional pivoting mechanisms.
The description of numerical numbers:
100: base assembly
110: upper case
120: lower case
121: bottom plate
130: steam jet
140: pad attachment protrusion
150: tube
170: tray
170a: tray plate
170b: rim
171: front removable piece
172: steam jet through-hole
173, 174: rear removable piece
173: rear removable and
engaged protruding piece
174: rear removable and
engaged stopping piece
175: pressing plate
177: brush
300: push stick assembly
310: housing
500: hinge assembly
510: first member
511: first tube
513: front and rear pivoting center axis
515: first arm
530: second member
531: second tube
535: second arm
550: left and right pivoting
551: left and right pivoting center axis
center axis member
553: flange
555: screw
570: eccentric member
571: locking hole
573: left and right pivotable
575: locking piece
groove
576: flange
577: elastic portion
578: spring
579: sheet cover | This invention relates to a hinge assembly for a steam cleaner capable of pivoting in front/rear (X) and left/right (Y) directions, and more particularly, to a hinge assembly for a steam cleaner capable of being adjusted automatically in a straight direction after a swerving force is removed, when a base assembly was swerved while locking automatically a left/right directional pivoting action. | 8 |
TECHNICAL FIELD OF THE INVENTION
In one aspect, the present invention relates to novel, improved methods and systems for identifying that one of a series of past events which most closely resembles a current happening.
BACKGROUND OF THE INVENTION
As in the case of humans, the optimum response of a mechanical, electromechanical, electronic, or other device to a present event can, in many cases, be optimized by taking into account the response made by the device to that historical event most closely matching a current event. Identification of the appropriate historical event can be accomplished by matching information representing the current event with information representing each of a series of past events and identifying that past event which is best correlated with the current event. A technique for doing this optically and the theory involved are described in THE FOUNDATION OF EMPIRICAL KNOWLEDGE, WITH A THEORY OF ARTIFICIAL INTELLIGENCE, Pieter J. van Heerden, N.V. Uitgeverij Wistik-Wassenaar, The Netherlands, 1968 and in U.S. Pat. Nos. 3,296,594 issued Jan. 3 1967 to van Heerden for OPTICAL ASSOCIATIVE MEMORY and 3,492,652 issued Jan. 27, 1970 to the same patentee for OPTICAL ASSOCIATIVE MEMORY SYSTEM.
SUMMARY OF THE INVENTION
We have now invented, and disclosed herein, certain new and novel methods and apparatus for carrying out this matching of functions which have the advantage that the matching of functions and identification of the past event most closely correlated with the current event can be accomplished much faster than it could be optically and with at least equal, if not greater, accuracy.
Speaking generally, this is accomplished in accord with the principles of the present invention by representing the current event and each of the past events with which the current event is to be matched by a string of binary digits. A herein described manipulation of these strings of digits is then employed to identify that past event which most closely matches the current event.
The strings of digits representing the past or historical events can be derived from that string of digits representing the current event. Alternatively, those digit strings can be derived from a binary digit string made available from a separate or independent source.
The required manipulation of the binary digits is carried out electronically. The system includes: an array of delay circuits for generating the series of binary digits representing past events from that string of digits representing the current event or the independently supplied data, circuits which function to identify that past event best correlated with the present event, and output circuitry which converts incoming information from the function matching circuitry to an optimum format. In addition, the system has switching means which allows binary digit strings to be inputted to the delay circuits from the independent source instead of inputting to those circuits the string of digits representing a current event.
Our novel information of data processing system has the advantage that it is made up of relatively uncomplicated circuit elements, that large binary digit strings can be handled, and that the requisite circuits can be provided on a single chip although this is certainly not required.
OBJECTS OF THE INVENTION
From the foregoing, it will be apparent to the reader that one primary and important object of the present invention resides in the provision of novel, improved methods and apparatus for making available to a mechanical, electromechanical, electronic, or other device information for optimizing the operation of that device.
Another primary and important object of the invention resides in the provision of methods and apparatus in accord with the preceding object in which the data inputted to the device is obtained by identifying that past event best correlated with a current event and inputting a set of data representing the thus identified historical event to the controlled device.
Still other more specific but nevertheless important objects of the invention reside in the provision of methods and apparatus in accord with the preceding object:
in which the data representing the historical event best matching the current event can be rapidly and accurately identfified;
in which, in conjuction with the preceding object, electronic data processeing is employed to identify that set of data representing the historical event best correleted with the current event;
in which the data representing past or historical events can be selectively: (1) derived from the data representing the current event, or (2) made available from an independent source.
which employ system elements that can be provided in the large numbers needed in practical applications of the invention on a single chip.
Other important objects and features and additional advantages of the invention will be apparent to the reader from the foregoing and the appended claims and as the ensuing detailed description and discussion of the invention proceeds in conjuction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
In the drawing:
FIG. 1 shows the relationship between FIGS. 1A and 1B which, taken together, constitute a block diagram of a system embodying the principles of the present invention and designed to identify that string of binary digits representing a past or historical event which is most closely correlated with a string of binary digits representing a current event of situation;
FIG. 2 is a schematic of one of several identical circuits employed in the system of FIG. 1 to: (a) add the string of digits representing the current event to each of the strings of digits representing past events by modulo two addition, and (b) identify the number of excess zeros in each of the resulting sum-representing strings of digits, the number of excess zeros being indicative of the degree of correlation between the current and past events;
FIG. 3 is a schematic of one of several identical comparator circuits employed in the system of FIG. 1 in a multilevel, single elimination array to identify that sum-representing string of digits having the greatest number of excess zeros by comparing successive pairs of the sum-representing strings of digits;
FIG. 4 is a schematic of a circuit employed in the system of FIG. 1 to: (a) convert the string of binary digits obtained by modulo two adding the strings representing the current and best correlated past events to the string of digits representing the best correlated historial event, and (b) output the latter string of digits from the system; and
FIG. 5 is a schematic of a switching circuit which is incorporated in the system of FIG. 1 and allows data representing historical events to be derived from data inputted from an independent source instead of being derived from the data representing the current event.
DETAILED DESCRIPTION OF THE INVENTION
We pointed out above that an input of optimum character for a wide variety of applications can be obtained by: (1) comparing what is happening in the present with what happened at each of a number of times in the past, and (2) deriving the input from that past event which most closely matches the present happening. We also pointed out that this comparison is made by characterizing the current event and past events with strings of binary digits and by identifying that string of digits representing a past event which has the highest degree of correlation with the string of digits representing the current event or a relatively recent event. Both the current and relatively recent events are for the most part referred to as the "current event" as a matter of covenience.
The identification of that event in the past which is most closely correlated with the current event is accomplished by adding the string of digits representing the current event with the string of digits representing each of the past events. The "adding module two (modulo two") from the of addition in which 1+1=0, 0+0=0, and 1+0=1 is employed; thus, the sum of each column is either a "1" or a "0", and there is no carryover from one column to the next.
It can be shown that the sum thus obtained by modulo two adding the strings of digits representing two randomly correlated events will contain equal number of ones and zeros and that the number of excess zeros; i.e., the number of zeros in excess of the expected 50 percent will increase with the degree of correlation between the two events. Thus, by modulo two adding the string of digits representing the current event in turn to that string representing each of the past events and counting the number of excess zeros in the stringe of digits representing each resulting sum, one can identify that past event which has the highest correlation with the current event.
In many cases, the most useful result can be obtained when the binary digits representing the past events are obtained from the string of binary digits representing the current event. If the digits representing the current event are acquired at equal intervals, those strings of digits representing the past events can be obtained by writing a series of binary digit strings representing the original string repeatedly delayed by one digit; i.e., the interval at which successive integers are acquired (clock time).
The string of digits representing the current event can be represented by the function or binary time series f(t) and the remaining binary digit streams, representing the related and relevant past events, by the terms D 1 f(t), D 2 f(t) . . . D k f(t) where k is the number of digits by which the time series f(t) is delayed; i.e., f(t-k). The expression "t" in the function f(t) represents the number of pulses in that time-related function (or in the hereinafter discussed, time related function g(t)). For example, in an application in which 113 pulses (each a 0 or a 1) are required at intervals of, say, one microsecond, the string of binary digits will contain 113 integers acquired over a period of 112 microseconds, the first digit having been acquired at t=0.
To illustrate, f(t) might be:
1110001011100010111100
In that example, D 1 f(t) would be:
11100010111000101110,
k is 20, and the entire series of time-related functions would be the following:
TABLE 1__________________________________________________________________________Time →-20 -19 -18 -17 -16 -15 -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1__________________________________________________________________________ 0f(t) 1 1 1 0 0 0 1 0 1 1 1 0 0 0 1 0 1 1 1 0 0D.sup.1 f(t) 1 1 1 0 0 0 1 0 1 1 1 0 0 0 1 0 1 1 1 0D.sup.2 f(t) 1 1 1 0 0 0 1 0 1 1 1 0 0 0 1 0 1 1 1D.sup.3 f(t) 1 1 1 0 0 0 1 0 1 1 1 0 0 0 1 0 1 1D.sup.4 f(t) 1 1 1 0 0 0 1 0 1 1 1 0 0 0 1 0 1D.sup.5 f(t) 1 1 1 0 0 0 1 0 1 1 1 0 0 0 1 1D.sup.6 f(t) 1 1 1 0 0 0 1 0 1 1 1 0 0 0 1D.sup.7 f(t) 1 1 1 0 0 0 1 0 1 1 1 0 0 1D.sup.8 f(t) 1 1 1 0 0 0 1 0 1 1 1 0 1D.sup.9 f(t) 1 1 1 0 0 0 1 0 1 1 1 1D.sup.10 f(t) 1 1 1 0 0 0 1 0 1 1 1D.sup.11 f(t) 1 1 1 0 0 0 1 0 1 1D.sup.12 f(t) 1 1 1 0 0 0 1 0 1D.sup.13 f(t) 1 1 1 0 0 0 1 1D.sup.14 f(t) 1 1 1 0 0 0 1D.sup.15 f(t) 1 1 1 0 0 0D.sup.16 f(t) 1 1 1 0 0D.sup.17 f(t) 1 1 1 0D.sup.18 f(t) 1 1 1D.sup.19 f(t) 1 1D.sup.20 f(t) 1__________________________________________________________________________
In this same example, the best match between the function f(t) representing the current event and the function D k f(t) representing each of the past events is obtained by modulo two adding the string of integers representing the current event to the string representing each of the pasts of that event and counting the numbers of excess zeros in each of the resulting sums. The sum is represented by the expression (1+D k )f(t); i.e., (1+D k )f(t)=f(t)+D k f(t)=f(t)+f(t-k).
For example, and with respect to the same f(t) as was identified above:
______________________________________f(t) 1 1 1 0 0 0 1 0 1 1 1 0 0 0 1 0 1 1 1 0 0D.sup.1 f(t) 1 1 1 0 0 0 1 0 1 1 1 0 0 0 1 0 1 1 1 0.sup.+(1 + D.sup.1)f(t) 0 0 1 0 0 1 1 1 0 0 1 0 0 1 1 1 0 0 1 0;______________________________________
the expected number of zeros in the sum is 10.5; the actual number of zeros is 12; and the excess number of zeros is 1.5, indicating that there is but a slight correlation between the current event (f(t)) and the past event (D 1 f(t)).
Table 2 below contains the entire set of sums (1+D)f(t) by modulo two addition for the particular f(t) being employed as an example:
TABLE 2__________________________________________________________________________*Time in Microseconds -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1__________________________________________________________________________ 0f(t) 1 1 1 1 0 0 0 1 0 1 1 1 0 0 0 1 0 1 1 1 0 0(1 + D) f(t) 0 0 0 1 0 0 1 1 1 0 0 1 0 0 1 1 1 0 0 1 0(1 + D.sup.2) f(t) 0 0 1 1 0 1 0 0 1 0 1 1 0 1 0 0 1 0 1 1(1 + D.sup.3) f(t) 0 1 1 1 1 0 1 0 1 1 1 1 1 0 1 0 1 1 1(1 + D.sup.4) f(t) 1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1(1 + D.sup.5) f(t) 1 1 0 1 1 1 1 1 0 1 0 1 1 1 1 1 0(1 + D.sup.6) f(t) 1 0 1 0 1 1 0 1 0 0 1 0 1 1 0 1(1 + D.sup.7) f(t) 0 1 0 0 1 0 0 1 1 1 0 0 1 0 0(1 + D.sup.8) f(t) 1 0 0 0 0 0 0 0 0 0 0 0 0 0(1 + D.sup.9) f(t) 0 0 0 1 0 0 1 1 1 0 0 1 0(1 + D.sup.10) f(t) 0 0 1 1 0 1 0 0 1 0 1 1(1 + D.sup.11) f(t) 0 1 1 1 1 0 1 0 1 1 1(1 + D.sup.12) f(t) 1 1 1 0 0 1 1 0 0 1(1 + D.sup.13) f(t) 1 1 0 1 1 1 1 1 0(1 + D.sup.14) f(t) 1 0 1 0 1 1 0 1(1 + D.sup.15) f(t) 0 1 0 0 1 0 0(1 + D.sup.16) f(t) 1 0 0 0 0 0(1 + D.sup.17) f(t) 0 0 0 1 0(1 + D.sup.18) f(t) 0 0 1 1(1 + D.sup.19) f(t) 0 1 1(1 + D.sup.20) f(t) 1 1(1 + D.sup.21) f(t) 0 1__________________________________________________________________________ *In this example, one microsecond is the interval between succeeding pulses
In this particular example, the highest correlation with the current event is between it and the past event represented by the function D 8 f(t). In particular: (1+D 8 )f(t)=[f(t)+f(t-8)] has 14 digits. The average number of digits is therefore 7, the actual number of zeros is 13, and the excess number of zeros is 13-7=6. This is an almost perfect correlation as the maximum possible number of zeros for a binary string with 14 integers is 7 (identical series). In other words, the more nearly the actual number of excess zeros approaches the theoretical number, the higher the degree of correlation there is between the two functions.
It will be remembered that it is the best correlated function D ko f(t) that is wanted as an output, not the sum of that function and f(t) shown in Table 2; i.e., (1+D ko )f(t). Once the closest correlation is found, D ko f(t) can easily and surprising be obtained by adding the related sum (1+D ko )f(t) to the original function f(t) because:
(1+D.sup.ko)f(t)+f(t)=
f(t)+D.sup.ko f(t)+f(t), and
f(t)+f(t)+D.sup.ko f(t)=D.sup.ko f(t)
inasmuch as f(t)+f(t) always equals zero because the terms in f(t) are the same and must be a zero or one, and 1+1=0 and 0+0=0 (these are the two possibilities in adding the like integers together).
Those skilled in the arts to which this invention relates will of course appreciate that the string of digits employed above as an example to represent an event is very much simpler than will typically be the case in actual practice. In an actual case, the string representing the current event may be several tens of thousands or even several hundreds of thousands of digits long. The duration of the intervals between the acquisition of digits may be measured in microseconds as in the example; but the duration of the interval may be longer or shorter. The several intervals between the acquisition of digits may be of equal, or different, durations. Therefore, it is not intended that the foregoing example be construed as a limit on the scope of protection sought in the appended claims.
Referring now to the drawing, FIG. 1 depicts a system 20 for identifying that one of a series of past or historical events which has the highest degree of correlation with a current (or recent) event in accord with the principles of the present invention. For purposes of discussion, it will first be assumed that the event with which the correlation is being made is a current event which can be represented by the expression or function f(t) and presented as a string of sequentially acquired binary digits. This string, identified as 2 in FIG. 1, is routed first to a modulo two adder 22 and then to a switch 24 which is employed to pass either: (a) the string 2 of binary digits, or (b) a string of binary digits 4 stored in a memory 26.
The output from switch 24, identified by reference character 7, is transmitted to the first (28-1) of a series of delay-by-one circuits 28-1 . . . 28-k with the output from each delay-by-one circuit 28 being inputted to the next in the series of delay-by-one circuits 28. These circuits therefore generate the strings of binary digits representing those several events D 1 f(t), D 2 f(t) . . . D k f(t) in the past history of the current event related by the function f(t).
Downstream from delay circuits 28 is a serially arranged set of circuits 30-0 . . . 30-7. Each of these circuits includes a modulo two adder 32 and an up/down counter 34 (see FIG. 2).
In each of the modulo two adders 30-0 . . . 30-7, the binary string of digits representing the current event-related function f(t) is added by modulo two addition to the string of binary digits outputted from an associated delay-by-one circuit 28 and representing a past or historical event D 1 f(t), D 2 f(t) . . . D k f(t) to form the binary digit strings representing the sums (1+D 1 )f(t), (1+D 2 )f(t) . . . (1+D 2 )f(t). The up/down counter 34 in each circuit 30 then counts the number of excess zeros in the binary digit string representing the sum (1+D)f(t) generated in its associated modulo two adder. The output from each circuit 30 thus contains: (1) a string of binary digits 10 representing the sum (1+D)f(t) generated in the modulo two adder 32 of that circuit, and (2) data (binary digit string) representing the number of excess zeros in that sum as counted in the up/down counter 34 of the circuit.
Next in the exemplary system 20 depicted in FIG. 1 of the drawing is a single elimination array 36 of comparators 38-1 . . . 38-7. These comparators are arranged in three tiers or levels 40, 42, and 44.
The comparators 38-1 . . . 38-4 in the first level 40 are inputted from an adjacent pair of modulo two adder, up/down counter circuits 30. Thus, the number of comparators 38 in the first or initial level 40 is one-half the number of circuits 30.
Each comparator 38 in the second and any subsequent level is inputted from an adjacent pair of comparators 38 in the preceding level so that each subsequent level has one-half the number of comparators in the preceding level with the final level having a single comparator 38-7.
Each comparator 38 in the first level 40 identifies that one of the sums (1+D)f(t) represented by the binary digit strings inputted to it which has the larger number of excess zeros and outputs that information. Comparator 38-1 in the illustrated circuit, for example, determines whether the binary digit string representing the sum (1+D 1 )f(t) or that binary digit string representing (1+D 2 )f(t) has the larger number of excess zeros while comparator 38-4 in level 1 similarly ascertains whether the binary digit string representing the past event-related function (1+D k-1 )f(t) or the past event-related function (1+D k )f(t) has the larger number of excess zeros and outputs that information.
From each comparator 38-1 . . . 38-4, the winner--i.e., the binary digit string with the larger number of excess zeros--advances to the next, intermediate level 42 of comparators 38. In this second, and each succeeding, level in comparator array 36, each comparator 38 is inputted from an adjacent pair of comparators 38 in the preceding level. Thus, in the illustrated system 20, the outputs from the comparators 38-1 and 38-2 in the first level 40 are inputted to the comparator 38-5 in the second level 42; and the outputs from the first level comparators 38-3 and 38-4 are inputted to the second level comparator 38-6.
As in the first level, the winner from each second level comparator--i.e., the binary digit string with the larger number of excess zeros--is advanced to the next level of comparators, in this case, final or output level 44 with its single comparator 38-7. Therefore outputted from comparator 38-7 is the sum of the current event-related function f(t) and that one of the functions (1+D ko )f(t) in the historical past of function f(t) which is most closely correlated with function f(t).
This string of binary digits, identified by reference character 1 in FIG. 1, is inputted to modulo two adder 22 where the string of binary digits 2 representing the current event-related function f(t) is added by modulo two addition to the string 1 of modulo two digits. Thus, binary adder 22 outputs that string of binary digits identified by reference character 3. This string of binary digits is of course the one representing that historical event-related function D ko f(t) which has the highest degree of correlation with the current event-related function f(t). The signal outputted from modulo two adder 22 in the form of a string of binary digits can therefore be employed to advantage to optimize the performance of the mechanical, electrical, mechanical, electronic, or other device identified in FIG. 1 by reference character 46.
The delay-by-one circuits 28 employed to generate the past event-related functions Df(t) may be D-type flip-flops as described in ELECTRONIC CIRCUITS, Holt, John Wiley & Sons, New York, NY, section 9-4, pages 263-266, 1978.
One representative circuit 30 in which binary adder 32 and up/down counter 34 are related in the manner discussed above is illustrated in FIG. 2. The up/down counter is mudo two conventional as is adder 32, which contains circuits for performing the exclusive-OB operation A+B=(A B) (A B). The strings of binary digits 2 and 9 representing: (1) the current event-related function f(t), and (2) a past event-related function D k f(t) are inputted to a modulo two adder 32, which consequently outputs a string 10 of binary digits representing the sum (1+D k )f(t). This output is supplied to the input side of up/down counter 34. It is also supplied to the input side of that comparator 38 in the initial tier or level 40 of comparator array 36 to which the particular circuit 30 is serially connected (see FIG. 1).
Also inputted to the up/down counter 34 are two additional signals identified by reference characters 6 and 8 in FIG. 1. These are respectively a clock signal and a signal for resetting counter 34 to zero. Both are conventional. The up/down counters 34 in the several mudo two adder/counter circuits 30 may be reset simultaneously--for example, at selected time intervals--or individually as the capacity of each counter 34 is reached.
As discussed above, the output from the up/down counter 34 is a set of data 11 identifing the number of excess zeros in the function (1+D)f(t) generated by the modulo two adder 32 of a particular circuit 30.
Turning now to FIG. 3, the comparators 38 employed in system 20 are equally conventional. Each includes a known comparator circuit 48 and an equally conventional data selector 50. The comparator 48 and data selector 50 identify, and output, that string 10 of binary digits representing a winning sum (1+D k )f(t) and the string 11 of binary digits identifying the number of excess zeros in the sum (1+D k )f(t). It is to be noted, in this respect, that both the string 10 and the string 11 of binary digits are needed as outputs. It is the ultimate, winning string 10 of digits that is formated into the output from system 20 whereas the string 11 of binary digits represents the number of excess zeros in binary digit string 10 and is, therefore, a measure of the degree of correlation between a given, historical event-related function (1+D)f(t) and the current event-representing function f(t).
Modulo two adder 22, shown in FIG. 4, includes circuits collectively identified by reference character 52 and typically of the same character as those identified by reference character 32 in FIG. 2. As discussed above, modulo two adder 22 is employed to add the string 2 of binary digits representing the current event-related function f(t) to that string 1 of binary digits representing the past event-related function D ko f(t) bearing the highest degree of correlation to function f(t) modulo two. The resulting sum is that above-discussed string of binary digits (identified by reference character 3 in FIG. 4) which represents the winning function D ko f(t) and is outputted from system 20.
The final major component of system 20, selector switch 24, is shown in detail in FIG. 5. In that figure, reference character 5 represents a single which is assumed to be: (1) present, that is 1111 . . . etc., if a match is to be made between a function of the character discussed above and identified by the expression f(t) and the functions D k f(t) representing the past history of that event, and (2) absent, that is 0000 . . . etc., if, instead, the match is to be made between the function f(t) and past events related to a function g(t) available from memory 26. These events in the history of function g(t) are identified as D 1 g(t), D 2 g(t) . . . D k g(t).
As is shown in FIG. 5, the binary digit string 2 representing f(t) is routed to switch 24 includes three gates 54, 56, and 58. In the first case, gate, 54, an "AND gate" will always output f(t), whether f(t) is a "1" or a "0", while at the same time gate 58, an "AND gate" with inputs 000 . . . etc. and g(t), will always output a "0". The "OR gate" 56 will therefore always output f(t) because it is inputted from the two parallel AND gates 54 and 56. Conversely, if switching signal 5 is 000 . . . etc., gate 54 will always output a "0", while "AND gate" 58, for which the input is now 111 . . . etc. and g(t), will always output g(t), and therefore the "OR gate" 56 now will always output g(t). With either input of gate 56 active, a stream of binary digits representing either the current event-related function f(t) (signal 5 present) or a binary stream of digits available from memory and representing a function g(t) (signal 5 absent) is outputted from OR gate 56 as indicated by reference character 7 in FIG. 5. In both cases the operation of the system is the same except that, if the function g(t) is selected from memory 26: (1) it is the binary digit strings representing functions D 1 g(t), D 2 g(t) . . . D k g(t) that are generated in delay-by-one circuits 28, and (2) it is the past event-related function D ko g(t) most closely correlated to current event-related function f(t) that is outputted from system 20.
The mode of operation employing memory 26 may be used, for example, to determine whether there is available from images stored in memory 26, for instance as in TV pictures of hundred lines of 200 binary digits each, scanned successively, and therefore represented by segments of 20000 binary digits each, and image similar to that image represented by the string 2 of binary digits. In this scenario, the image available at 2 (the current event) is represented by the function f(t), and the images stored in memory (the past events) are represented by the functions g 1 f(t), g 2 f(t) . . . g r f(t) where the expression "r" represents the number of images stored in memory 26. The degree of correlation between the function f(t) and the functions g(t), D 1 g(t), D 2 g(t) . . . D k g(t) for each of the images represented by a function g(t) is ascertained and the correlations compared in system 20 in the manner discussed above. The function g(t) or D k g(t) with the highest degree of correlation will thus be the one related to that image which most closely resembles the image represented by the function f(t). It may be that the recognizable part in the TV picture of the example, call it g r (t), although of exactly the same dimensions, is displaced with respect to the part to be recognized in f(t), vertically and horizontally. This simply means that some D k g(t) will provide the exact match with the digits of the image to be recognized and therefore will emerge as the winner.
The best match between the current image and those created in the past may be between two images in which one element of the image (or the entire image) is shifted to different coordinates. This contingency is easily provided for. For example, memory may hold multiple images, each represented by a string of k binayr digits. The best match between the current and past event-related functions, taking shifted image and image elements into account, will be found by modulo two adding with the terms of f(t) all members of each set g(t), D 1 g(t), D 2 g(t) . . . D k g(t) and then identifying that resulting sum (1+D)g(t) with the largest number of excess zeros.
As discussed above, and depending upon the particular application of the invention, it may be that event in the more recent past of a current event represented by f(t) having the highest degree of correlation with an event in the more distant past of the current event or an event in the past of a current event represented by g(t) that can most usefully by outputted from the modulo two adder 22 of system 20. In this case, the function with which the correlation is to be made can be identified as D m f(t), the historical past of f(t) as D m+1 f(t), D m+2 f(t) . . . D k f(t), and the past of g(t) by the same series D 1 g(t), D 2 g(t) . . . D k g(t) as was set forth above. The term "m" will typically be 1 or another small number, but it may be any number smaller than k.
It will be obvious to those skilled in the arts to which this invention relates that those just-discussed implementations of the invention can be carried out in system 20 as easily as those in which it is the current event related by the function f(t) with which the correlation is to be made. The only essential differences are that: (1) the string 2 of modulo two digits inputted to the first of the serially connected binary adders 30-0 is the string representing D m f(t), and (2) the strings inputted to the remaining ones of the modulo two adders 30-1 . . . 30-K represent the functions D m+1 f(t), D m+2 f(t) . . . D k f(t) (or D 1 g(t), D 2 g(t) . . . D k g(t)).
The information embodied in those strings of binary digits representing the functions f(t) and g(t) and the historical pasts of those functions--D 1 f(t), D 2 f(t) . . . D k f(t) and D 1 g(t), D 2 g(t) . . . D k g(t)--may be of the same type or of many different types. For example in the case of a robot designed to emulate human responses, f(t) might be composed of information representing: analogs of human drives F 1 (t), sensory inputs f 2 (t), and muscular responses f 3 (t) with f(t) representing short, regularly alternating, segments of f 1 (t), f 2 (t), and f 3 (t).
In many cases, the device 46 to which data is outputted from system 20 wil be computer controlled. In these applications, system 20 has the advantage that its output is in binary form, facilitating the acquisition of the outputted data by the device controlling computer(s). Other applications require, or can at least more easily utilize, an input in analog form. In those applications, a conventional D/A (digital-to-analog) converter can be employed to convert the data outputted from system 20 to the more useful, or required, analog form.
It is also to be understood that the term "device" has been used above in a very loose sense. The "device" with a modus operandi controlled (at least in part) by data inputted to it in accord with the principles of the present invention may be a very simple one or that which is controlled may be a complex system.
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description; and all changes which came within the meaning and range of equivalency of the claims are thereofre intended to be embraced therein. | Methods and systems that employ electronic data processing to identify a set of data which can be outputted to a mechanical, electromechanical, electronic, or other device to optimize the performance of that device. The data to be outputted is identified by writing a function which represents a current event or situation as a string of binary digits, finding that one of a series of functions similarly representing past or historical events which is most closely correlated with the current event-representing function, and outputting the string of digits representing the thus identified historical event. The functions representing historical events can be derived from the function representing the current event or from information supplied from a separate source. The system includes delay circuits for generating the historical event-representing strings of digits, circuits for adding the string of digits representing the current situation to the string of digits representing each of the historical events by modulo two addition and counting the number of excess zeros in each resulting sum, a single elimination array of comparators for matching successive pairs of sum-representing strings of digits in enough levels to identify that string of digits with the largest number of excess zeros, and circuitry for: converting the winning string of digits back to the format in which the associated historical event is represented and outputting the string of digits in that format. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to therapeutic systems. More specifically, the present invention relates to methods and apparatus for providing electrical and thermal stimulation.
[0003] 2. Description of the Related Art
[0004] For a variety of therapeutic applications, several treatment modalities are currently known in the art including electrical stimulation, heat therapy and thermostimulation. Electrical stimulation involves the application of an electrical current to a single muscle or a group of muscles. The resulting contraction can produce a variety of effects from strengthening injured muscles and reducing oedema to relieving pain and promoting healing. Many electrical stimulation systems are limited to two to four channels and therefore allow only two to four pads to be applied to a patient. The pads are usually quite small and typically powered with a battery. This results in the application of a small amount of power and a low treatment depth of the resulting electric field. The shallow depth of the electric field generated by conventional electrical stimulation systems limits performance and patient benefit. Some systems have attempted to address this limitation by applying more current, often from a line or main supply source. However, the small size of conventional electrical stimulation pads is such that on the application of larger amounts of power, i.e. the use of higher currents, patients often report the experience of pain or discomfort.
[0005] Heat therapy or thermal stimulation itself is very useful as it has a number of effects such as relaxation of muscle spasm and increased blood flow that promotes healing. However, combination therapy, i.e. the synergistic use of other modalities such as massage, ultrasound and/or electrical stimulation has been found to be more effective than heat therapy alone.
[0006] Thermostimulation is one such combination therapy that involves the use of heat therapy and electrical stimulation simultaneously. With thermostimulation, the healing benefits of heat are provided along with the strengthening, toning, pain relieving and healing benefits of electrical stimulation. Moreover, the application of heat has been found effective in that it allows the patient to tolerate higher currents. This yields higher electric fields strengths, greater depths of penetration and therefore, more positive results than could be achieved with electrical stimulation without heat.
[0007] Unfortunately, there are several problems associated with conventional thermostimulation systems. One problem is due to poor or inadequate pad design. That is, conventional pads are small, hard and die cut with sharp flat edges. The rectangular shape of the pads does not conform to the natural shape of muscle tissue. In addition, conventional pads tend to exhibit a current fall off over the length of the pad. This limits the performance of conventional pads. Further, the connectors are subject to detachment and therefor often fail to comply with government requirements in certain countries. (See for example EN standard 60601-2-35 for medical electrical devices.)
[0008] Further, conventional thermostimulation pads are not waterproof. As a consequence, sweat from the patient combined with the pad gel can cause the stimulation connector and press studs to short directly to the patient, which can result in the patient being shocked or burned.
[0009] Moreover, conventional thermostimulation pads are generally inflexible and yield to breakage of the heating element if bent or folded too frequently. More significantly, conventional thermostimulation pads are not designed to detect, measure and/or monitor temperature of the pad when on the patient. Consequently, effective temperature regulation is not provided with conventional thermostimulation systems.
[0010] Hence, a need remains in the art for an improved system or method for thermostimulation therapy that is more safe and effective.
SUMMARY OF THE INVENTION
[0011] The need in the art is addressed by the thermostimulation system and method of the present invention. The inventive thermostimulation system is adapted for use with a console for providing electrical currents for thermal and electrical stimulation in response to a first input from an operator via at least one electrical connector. Generally, the inventive thermostimulation system includes at least one inline control system coupled to the console for regulating the currents to an associated thermostimulation pad. The pad has a temperature sensor adapted to provide a feedback signal to the inline control system.
[0012] In more specific embodiments, plural pads and inline control systems are connected to the console. Each inline control system has a first microprocessor for providing heat and stimulation current control for the pad and a second microprocessor for providing over-temperature control for the pad. Each inline control system has a display and a button to allow confirmation of temperatures of more than 38 degrees Celsius. Each pad has a connector integrated multilayer construction with a heating element implemented with a wire matrix and slots for flexibility. In addition to a temperature sensor, each pad also includes two electrical stimulation contacts having a wire conductor along the length thereof. Each pad is connected to an associated inline control system via a flat cable. Specially designed strain relief grommets are provided on both ends of the flat cable where they terminate with the pad or inline control system.
[0013] The inventive thermostimulation method includes the steps of applying a thermostimulation pad with connector integrated multilayer construction to a patient having a temperature sensor adapted to feedback a temperature signal; coupling the pad to a console via an inline control system; setting the console to generate predetermined electrical currents to the inline control system for thermal and electrical stimulation via a first connector; and regulating the temperature of the pad via the inline control system in response to the predetermined electrical current for thermal stimulation and the feedback temperature signal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a perspective view of a typical thermostimulation system implemented in accordance with conventional teachings.
[0015] FIG. 2 is a simplified block diagram of a typical thermostimulation electrical system provided within the console of FIG. 1 .
[0016] FIGS. 3 a - 3 c illustrate the typical conventional thermostimulation pad of FIGS. 1 and 2 in more detail. FIG. 3 a is a top view of the pad, FIG. 3 b is a sectional side view taken along the line 3 b - 3 b of FIG. 3 a , and FIG. 3 c is a bottom view of the pad.
[0017] FIG. 4 is a simplified perspective view of a thermostimulation system implemented in accordance with an illustrative embodiment of the present teachings.
[0018] FIG. 5 shows a perspective bottom view of the pad of FIG. 4 .
[0019] FIG. 6 is an exploded upside down view of a portion of the pad of FIG. 4 in disassembled relation.
[0020] FIG. 6 a is a top plan view of the heating element of the illustrative embodiment of the pad of FIG. 4 .
[0021] FIG. 6 b is a magnified view of a portion of the heating element of FIG. 6 a.
[0022] FIGS. 6 c - g show the grommet used in the pad of FIG. 4 .
[0023] FIG. 6 c shows an upper section of the illustrative implementation of the grommet.
[0024] FIG. 6 d shows a lower section of the illustrative implementation of the grommet.
[0025] FIG. 6 e is a top view of the grommet.
[0026] FIG. 6 f is a side view of the grommet.
[0027] FIG. 6 g is a perspective view of the upper section of the grommet.
[0028] FIG. 7 is a perspective side view of the inline control system of FIG. 4 fully assembled.
[0029] FIG. 8 is a perspective side view of the inline control system of FIG. 7 disassembled.
[0030] FIG. 9 is a sectional side view of the inline control system of FIG. 4 fully assembled.
[0031] FIG. 10 below is an electrical block diagram of the inventive system including the control system elements.
[0032] FIGS. 11 a - c are flow diagrams of the firmware in accordance with an illustrative embodiment of the present teachings.
[0033] FIG. 11 a is a flow diagram of the firmware executed by the main microcontroller of FIG. 10 .
[0034] FIG. 11 b is a flow diagram of the firmware executed by the safety microcontroller of FIG. 10 .
[0035] FIG. 11 c is a flow diagram of the firmware executed by the main and safety microcontrollers of FIG. 10 for a self-test mode of operation.
DESCRIPTION OF THE INVENTION
[0036] Illustrative embodiments and exemplary applications will now be described with reference to the accompanying drawings to disclose the advantageous teachings of the present invention.
[0037] While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications, and embodiments within the scope thereof and additional fields in which the present invention would be of significant utility.
Conventional Thermostimulation System
[0038] FIG. 1 is a perspective view of a typical thermostimulation system implemented in accordance with conventional teachings. The system 10 ′ includes a conventional thermostimulation console 20 ′ and a plurality of thermostimulation pads 30 ′. The console may be purchased from Ross Estetica of Barcelona Spain. (See http://corporativa.ross.es/rosseng/ross/indexross.htm.)
[0039] FIG. 2 is a simplified block diagram of a typical thermostimulation electrical system provided within the console of FIG. 1 . The system 10 ′ includes a power supply 22 ′ disposed in the console 20 ′ that provides current for the pads 30 ′ through a set of attenuators 24 ′ and 26 ′ for each pad 30 ′. The first attenuator 24 ′ regulates current to a set of stimulation contacts 32 and 34 provided on an exposed surface of the pad 30 ′ and the second attenuator 26 ′ regulates current to a heating coil 36 ′ embedded within the pad. A pad select switch 28 ′ provides an enable signal for each attenuator under operator control and outputs the setting level status to the operator via a display 29 ′. Note that the system 10 ′ only sets the heat and stimulation current levels. As no temperature sensor is provided in the conventional pad 30 ′, no pad temperature regulation or control is possible.
[0040] In addition, it should also be noted that the electrical arrangement of FIG. 2 is provided for illustration only. Other electrical arrangements may be known and used in the art.
[0041] FIGS. 3 a - 3 c illustrate the typical conventional thermostimulation pad 30 ′ of FIGS. 1 and 2 in more detail. FIG. 3 a is a top view of the pad, FIG. 3 b is a sectional side view taken along the line b-b of FIG. 3 a , and FIG. 3 c is a bottom view of the pad. The conventional pads 30 ′ are fabricated of silicone sheets glued together to encapsulate a foil heater with a separate wire for an electrostimulation pad. The pads are die cut from rolled sheets of silicone and therefore typically have sharp edges that are often uncomfortable to the patient. The upper surface is translucent and the bottom surface is gray silicone.
[0042] As best illustrated in the side view of FIG. 3 b , the conventional pad 30 ′ includes the first and second electrically conductive strips 32 ′ and 34′ for electrostimulation. Shown more clearly in the bottom view of FIG. 3 c , the strips 32 ′ and 34′ are fabricated of carbon loaded silicone (i.e., polymerized siloxane or polysiloxane) or other suitable material. Returning to FIG. 3 b , the conductive strips 32 ′ and 34 ′ are secured to a pad body 38 ′ by a layer or pad of glue 35 ′.
[0043] Typically, the pad body 38 ′ is also fabricated of silicone. A second layer of silicone 39 ′ is provided on the pad body 38 ′ for structural support. The upper surface of the second layer 39 ′ is typically treated with a primer (not shown) and the heating element 36 ′ is mounted between the primed second layer 39 ′ and a primed third layer of silicone 42 ′. The heating element 36 ′ is typically a coil fabricated with aluminum foil.
[0044] Stimulation current is provided via wires 70 ′ attached to the conductive strips 32 ′ and 34 ′ by first and second press stud type connectors 44 ′ and 46 ′. Though not shown in FIG. 3 b , the connectors 44 ′ and 46 ′ extend through the third, second and first structural layers 42 ′, 39 ′ and 38 ′ sequentially to connect with the electrical stimulation strips 32 ′ and 34 ′. Silicone covers 48 ′ and 49 ′ extend around the upper end of the connectors 44 ′ and 46 ′ respectively to protect the patient from electrical burns. In FIG. 3 b , the cover 48 ′ is shown depressed to expose the connector 44 ′ to illustrate that a wire from the console 20 ′ may be clipped thereto.
[0045] A second set of connectors 52 ′ and 54 ′ extend through the third layer 42 ′ to the heating coil 36 ′ and provide electrical connectivity thereto. Silicone covers 56 ′ and 58 ′ are provided for the second set of connectors 52 ′ and 54 ′ respectively.
[0046] As noted above, there are several shortcomings associated with the conventional pad design set forth above. That is, conventional pads are hard and die cut with sharp flat edges. The rectangular shape of the pads does not conform to the natural shape of muscle tissue. In addition, conventional pads tend to exhibit a current fall off over the length of the pad. This limits the performance of conventional pads. Further, the connectors are subject to detachment and therefor often fail to comply with government requirements in certain countries i.e., EN standard 60601-2-35 for medical electrical devices. In addition, conventional thermostimulation pads are not waterproof and have recesses into which materials can be deposited which are difficult to clean and could carry risk of infection from patient to patient. As a consequence, sweat from the patient combined with the pad gel can cause the stimulation connector and press studs to short directly to the patient, which can result in the patient being shocked or burned. Moreover, conventional thermostimulation pads are too hard and, being too inflexible, yield to frequent bending and breakage of the coil disposed therein. More significantly, conventional thermostimulation pads are not designed to detect, measure and/or monitor temperature. Hence, a need remains in the art for an improved system or method for thermostimulation therapy that is more safe and effective. As discussed more fully below, the inventive pads address this need in the art.
Inventive System
[0047] Overall System
[0048] FIG. 4 is a simplified perspective view of a thermostimulation system implemented in accordance with an illustrative embodiment of the present teachings. As shown in FIG. 4 , the system 10 includes a conventional thermostimulation console 20 ′ with, in accordance with the present teachings, a plurality of novel thermostimulation pad assemblies 30 electrically coupled thereto. Each pad assembly 30 includes a novel inline control system 40 and an associated multilayer injection molded dual function (heat and stimulation) pad 50 of unique design and construction with integrated sensor in accordance with the present teachings. Each control system 40 is connected to an associated pad 50 via a cable 60 . As discussed more fully below, in the best mode, the cable 60 is flat.
[0049] Pads
[0050] FIG. 5 shows a perspective bottom view of the pad 50 of FIG. 4 . FIG. 6 is an exploded upside down view of a portion of the pad 50 of FIG. 4 in disassembled relation. As shown in FIGS. 5 and 6 , the pad 50 includes first and second elongate substantially parallel conductive strips 552 and 554 . In the illustrative embodiment, each conductive strip has a Shore hardness of 50 A—i.e. medical grade (USB Class 6) ten percent (10%) carbon loaded silicone. For example, Wacker LR 3162 could be used. This product has an electrical resistance of 1 kΩ per cm. In the illustrative embodiment, the strips are 51.5 millimeters (mm) wide, 521 mm in length and 1.85 mm thick. Those of ordinary skill in the art will appreciate that the present teachings are not limited to the dimensions of the illustrative embodiment.
[0051] A polymer connector 556 is coupled to one end of the first and second strips 552 and 554 and serves as an end piece therefor and the second end of each strip is free. In the illustrative embodiment, the connector 556 is fabricated of Shore 40 A silicone and serves as an insulator and support for wires 558 and 559 that provide a connection to the strips 552 and 554 respectively. In practice, one of the strips is powered a positive contact and the other provides a negative contact.
[0052] The two strips 552 and 554 are molded and then the end piece 556 is molded separately. These pieces are glued together and placed back into a mold and the next layer 560 is over-molded over the assembly to provide a single molded piece consisting of the strips 552 , 554 , end piece 556 , and layer 560 . In the preferred embodiment, the over-layer 560 is made of medical grade Shore 40 A polymer or other material suitable for a particular application. Note the grooves 553 and 555 and recess 557 within the over-layer adapted to receive and seat the strips 552 and 554 and the end piece 556 respectively. The wires 558 and 559 are then laid into the slots running through the overmould layer and into the grooves in the stimulation strips 552 and 554 . The wires are then glued in place using a carbon loaded RTV (room temperature vulcanized) silicone glue. This allows for the electrical current to be passed from the wires 558 and 559 to the stimulation strips 552 and 554 . Once cured, the remaining space in the slot in the 560 overmould layer is filled with non-conductive RTV silicone glue up to the same level of the surface of the overmould layer 560 .
[0053] As shown in FIG. 6 , a heating element 570 is provided over the layer 560 . In the best mode, the heating element 570 is implemented as a built in wire matrix and is held in place with a layer of silicone 580 . First and second temperature sensors 572 and 574 are mounted in the heating element 570 , one is a live sensor measuring temperature and feeding this information back to the control box and the second is a back up should the first sensor fail. In the illustrative embodiment, each temperature sensor is implemented as a conventional 1 kilo-ohm RTD (resistive temperature detector). In the illustrative embodiment, the heating element is a wire matrix bonded in silicone with a thickness of 0.75 mm, over the majority of the surface apart from where the RTDs are mounted, and is rated at 400 watts per square meter using 24 volts alternating current. Note the provision of slots 576 in the heating element 570 . These slots serve to improve flexibility in all planes of the element.
[0054] In the illustrative embodiment, as illustrated in the top plan view of FIG. 6 a and the magnified view of FIG. 6 b , the extension 578 of the heating element 570 has a number of solder connections to facilitate electrical connection of the heating element 570 to the cable 60 . The extension tab 578 is adapted to be received within a strain relief grommet 582 in the heater over-layer 580 along with the extensions 562 of the end piece 556 and 564 of the layer 560 . In the illustrative embodiment, the grommet does not come into contact with the extension 578 . The grommet 582 receives the flat cable 60 which is then stripped back and the associated wires are connected to the various solder pads on the extension 578 . FIG. 6 c shows the upper section 584 of the illustrative implementation of the grommet 582 . FIG. 6 d shows the lower section 586 of the illustrative implementation of the grommet 582 . FIG. 6 e is a top view of the grommet, FIG. 6 f is a side view of the grommet and FIG. 6 g is a perspective view of the upper section of the grommet 582 . In the preferred embodiment, the grommet 582 is made of TPU (thermoplastic polyurethane) and is implemented in two halves, an upper section 584 and a lower section 586 . The upper and lower sections 584 and 586 are glued together and these sections are glued to the flat cable 60 . In the best mode, the upper and lower sections 584 and 586 of the grommet 582 are glued together and to the cable 60 with cyanoacrylate glue.
[0055] Those skilled in the art will appreciate that the present invention is not limited to the materials utilized in the fabrication of the illustrative embodiment. Other materials may be used without departing from the scope of the present teachings.
[0056] In the illustrative embodiment, the heater over-layer 580 is Shore 40 A medical grade silicone in construction. Nonetheless, as noted above, it should be noted that the present invention is not limited to any particular material or hardness.
[0057] Each pad is assembled from the stimulation side. In the best mode, the structure of the pad 50 is based on a multi-step injection molding process, with over-molding of the various layers to build up the base of the pad to the complete pad thickness and embed and encapsulate the various components within it, such as the electrostimulation wires and heating element. The final step is to insert and bond the top lid of the pad into the assembled structure. The steps of the injection molding process include moulding of the stimulation strips, over moulding of the stimulation strips to encapsulate the stimulation wires to create the patient facing surface of the pad and the moulding of the lid of the pad 580 which encapsulates the heating element and creates the upper facing surface of the pad and seals in the flat cable and grommet.
[0058] Hence, in accordance with the present teachings, the strips 552 and 554 and the layers 560 , 570 and 580 and the grommet 582 are molded into a single unitary multilayer injection molded dual function (heat and electrostimulation) construction.
[0059] Flat Cables
[0060] Returning to FIG. 4 , a novel flat cable 60 connects each pad to its associated inline control and a conventional cable 70 is used to connect each inline control system to the console 20 . The flat cables 60 enhance patient comfort. In the illustrative embodiment, the flat cable 60 linking the control system 40 to the pad 50 is approximately 2.5 meters long and 17.38 mm wide. The cable 60 has inner core of 14 insulated wires, with an outer protective sheath in a white polyvinyl chloride (PVC). Flat cables are commercially available from manufacturers such as Spectra Strip of Hampshire, Great Britain.
[0061] Inline Control System
[0062] FIG. 7 is a perspective side view of the inline control system 40 of FIG. 4 fully assembled.
[0063] FIG. 8 is a perspective side view of the inline control system 40 of FIG. 7 disassembled. As shown in FIG. 8 , the control system 40 includes a two part injected molded ABS plastic housing 410 with an upper casing 412 and a lower casing 414 . The housing 410 is adapted to retain a multilayer printed circuit board 418 on which an integrated circuit 420 is disposed. A microprocessor (not shown) is provided by the integrated circuit 420 . Numerous additional electrical components are mounted onto the printed circuit board 418 along with a liquid crystal display (LCD) 422 .
[0064] As shown in FIG. 8 , a small Perspex window 430 protects the LCD 422 . In the best mode, the LCD display 422 shows both the target and actual temperatures for the associated pad. The window 430 seats within an aperture 426 in the upper casing 412 of the housing 410 . A plate 430 contoured to fit within a depression on the upper surface of the upper casing 412 is fitted with a manual override switch 432 . The switch 432 connects to the control circuitry on the printed circuit board 418 via a flexible wire 434 and pins 436 .
[0065] In the illustrative embodiment, a switch is used to enable the user to confirm when a user wants to heat a pad 50 above 38 degrees Celsius. The round cable 70 coming from the console 20 enters the top of the control system 40 and is held in place by a second grommet 438 . The flat cable 60 enters the system 40 from the bottom and is held in place by a third grommet 440 that is also used as a strain relief device at the cable termination with the pad. In the illustrative embodiment, this grommet is a standard, over-the-counter cable retention fixator. As discussed more fully below, the third grommet 440 is a two section grommet which captures the flat cable as it enters the system 40 . The system 40 is then held together by four screws 416 . As illustrated in the sectional side view of FIG. 9 , when secured together, the upper and lower casings 412 and 414 provide first and second chambers for seating the second grommet 438 and the third grommet 440 .
[0066] Electronics
[0067] As mentioned above, each pad has a heating element, two RTD sensors (one for active temperature control and another for backup) and two stimulation pads that make electrical contact with the user.
[0068] FIG. 10 is an electrical block diagram of the inventive system 10 including the control system elements 40 . The circuitry of the control system 40 is powered by the heating current from the console 20 . The control system 40 provides intelligent operation for the pad 50 , monitoring the current going to both electrostimulation pads 552 and 554 and the heating element 570 . These currents can be set at different levels by the control system 40 depending on the program selected or manually adjusted after a program is selected. The conventional console 20 does not allow for the temperature to be measured or monitored but instead typically has a heating current level setting described as a “heating percentage”. Since a regulation or control functionality is not conventionally available, the current sent to the pads could allow them to heat to more than 42 degrees Celsius, a level which is outside of safe levels and the requirements set by the EN60601-2-35 standard.
[0069] As illustrated in FIG. 10 , in the illustrative embodiment, each control system 40 is implemented with first and second microcontrollers (implemented in the best mode with microprocessors) 404 and 402 , that control and interrupt the current to the stimulation electrodes 552 and 554 and the heating element 570 of FIG. 6 respectively. The first controller 404 serves as a main controller and the second controller 402 serves as a safety controller. As discussed more fully below, each microcontroller runs unique software (i.e. firmware) stored on a tangible medium, such as an electrically erasable programmable read only memory (EPROM), in the integrated circuit 420 of FIG. 8 .
[0070] Software
[0071] FIGS. 11 a - c are flow diagrams of the firmware executed by the microprocessors in accordance with an illustrative embodiment of the present teachings. FIG. 11 a is a flow diagram of the firmware executed by the main microcontroller 402 of FIG. 10 . FIG. 11 b is a flow diagram of the firmware executed by the safety microcontroller 402 of FIG. 10 . FIG. 11 c is a flow diagram of the firmware executed by the main and safety microcontrollers of FIG. 10 for a self-test mode of operation. Both microcontrollers monitor the heating power control devices to determine whether they perform the correct on-off switching action or have failed as a short circuit or an open circuit. During the power up stage, the MMC and SMC communicate using an asynchronous communications link. In the illustrative embodiment, the microprocessors communicate with each other every second to pass status information using an I2C serial interface.
[0072] The MMC 404 sends messages to the SMC to tell it which test is being performed and then the SMC 402 sends the results of the tests at each stage. Only if all the stages pass with no failures is power applied to the heating circuit 570 in the pad.
[0073] During power up ( 602 ), or at a power setting greater than five percent (5%) of maximum, the main microcontroller (MMC) 404 performs a self-test ( 604 ) to detect any possible failures and then communicates with the safety microcontroller (SMC) 402 . As illustrated in FIG. 11 c , the self-tests are synchronised such that all hardware functionality is tested before enabling heating power to the patient.
[0074] The pad assembly, including the electronics, is calibrated. Calibration information is stored in an EPROM (not shown) within the MMC 404 . In order that the SMC 402 can accurately determine whether the associated regulated pad is overheating, a calibrated maximum temperature value is passed from the MMC to the SMC during the power up procedure.
[0075] After checking for faults ( 606 ) the MMC 404 enables stimulation ( 608 ) and monitors the percentage power setting of the console 20 (see steps 614 - 616 ). This is used to set a target temperature for the pad. This target temperature is displayed on the LCD 422 . Should the target temperature be greater than 38° C. the software 600 requires the operator to press the front panel switch on the console 20 to confirm the intention to set a higher temperature. Table I below lists illustrative target temperatures corresponding to various power levels.
[0000] TABLE I Power setting % Target Temperature 5-20 36 20-30 37 30-40 38 40-50 39 50-60 40 60-100 41
In the illustrative embodiment, a reduction in target temperature would not have to be confirmed.
[0076] During the pre-heating stage of a procedure the CTEMS unit demand 100% heat for three minutes. This is to heat up the pads prior to placement on a patient. This is interpreted as a demand for 41° C. and if this temperature is not confirmed by the operator the unit will heat up to the safety temperature of 38° C.
[0077] The MMC controls the temperature using a PID control loop. The actual temperature is measured using the temperature sensor 572 embedded in the pad. The SMC monitors the pad temperature using the other temperature sensor 574 .
[0078] There is a two colour LED in the front facing section of the connection box. This will flash red and green and is used to provide status information.
[0000]
TABLE II
LED
Information
Green flashing
Heating up to target
Green continuous
Target reached
Red flashing
Over temperature, when actual is above
target but not above 42° C.
Red continuous
Fault, heating and stimulation disabled. This
could be temperature above 42° C. or a
hardware fault.
[0079] As shown in FIG. 11 b , after performing self-tests ( 634 ) the SMC 402 measures the safety temperature via the second sensor 574 and disables the associated pad 50 if the specified maximum temperature is reached or exceeded.
[0080] Operation
[0081] The following describes the method of operation of the inventive system 10 in accordance with an illustrative implementation thereof:
[0082] 1. First, the operator plugs the pad cord 70 into the front of the console 20 .
[0083] 2. Next, the operator selects the desired program and starts the preheating phase. The display will flash at 41° C. and then heat up to 38° C. unless the override button 432 ( FIG. 8 ) is pressed at which stage it would heat to 41° C. The preheating phase lasts for 3 minutes (and can be repeated).
[0084] 3. Once the preheating is complete, the user presses “pause” on the system itself and the LCD display on the connection box will go blank.
[0085] 4. The patient is laid on the bed and the pads are strapped to the patient in the desired configuration.
[0086] 5. The operator then presses pause again and the program starts. The LCD 422 will then show the actual and target temperature again and the user will have to press the membrane button on each pad if the system program has a current % of 40% or above to allow the pad to heat to above 38° C.
[0087] 6. The pad control system 40 will then monitor the temperature and ensure that it does not go above the desired level.
[0088] 7. If the LED goes continually red for a period of more than a couple of minutes pad control system 40 will interrupt all the currents (both electrical stimulation and heat) to the pad and the operator will put the system on pause and replace the pad.
[0089] Thus, the present invention has been described herein with reference to a particular embodiment for a particular application. Those having ordinary skill in the art and access to the present teachings will recognize additional modifications, applications and embodiments within the scope thereof.
[0090] It is therefore intended by the appended claims to cover any and all such applications, modifications and embodiments within the scope of the present invention.
[0091] Accordingly, | A thermostimulation system and method. The inventive thermostimulation system is adapted for use with a console for providing electrical currents for thermal and electrical stimulation in response to a first input from an operator via at least one electrical connector. Generally, the inventive thermostimulation system includes at least one inline control system coupled to the console via electrical connector for regulating the currents to an associated thermostimulation pad via a second connector. The pad has a temperature sensor adapted to provide a feedback signal to the inline control system. In more specific embodiments, plural pads and inline control systems are connected to the console. Each inline control system has a first microprocessor for providing heat and stimulation current control for the pad and a second microprocessor for providing overcurrent safety control for the pad. Each inline control system has a display and a patient over-temperature control switch. Each pad has a connector integrated multilayer construction with a heating element implemented with a wire matrix and slots for flexibility. In addition to a temperature sensor, each pad also includes two electrical stimulation contacts having a wire conductor along the length thereof. Each pad is connected to an associated inline control system via a flat connector. Specially designed strain relief grommets are provided on both ends of the flat cable. | 0 |
CROSS-REFERENCE TO OTHER APPLICATIONS
[0001] This application is a divisional application of Ser. No. 09/738,823 filed Dec. 1, 2000, entitled “IR Source, Method and Apparatus” the entire disclosure of which is incorporated herein by reference.
[0002] This invention relates to an IR (infra-red) source, and more particularly to a structure of an IR source to be used on targets to allow the siting of weapons having appropriate sensors on the target.
[0003] In the accompanying drawings:
[0004] [0004]FIG. 1 shows an exploded view of the apparatus.
[0005] [0005]FIG. 2 shows a side view of a target, in this case a drone aircraft, with the apparatus mounted thereon.
[0006] [0006]FIG. 3 shows a top view of the target depicted in FIG. 2.
[0007] [0007]FIG. 4 shows a view of what an observer perceives from the IR source.
OVERVIEW
[0008] An overview of the apparatus of the present invention is depicted in FIG. 1. The IR source 1 is comprised of a catalytic assembly 10 , which radiates when contacted by a first fluid 15 , positioned within an exit 17 of a housing 5 . Housing 5 is depicted in two parts to more clearly show that catalytic assembly 10 is positioned within exit 17 of housing 5 . It should further be understood that there can be multiple exits 17 each with a catalytic assembly 10 positioned therein.
[0009] The catalytic assembly 10 is comprised an element 50 with a catalyst 51 positioned thereon. The catalytic assembly 10 can be made from a single element or a plurality of elements.
[0010] The entrance 16 of housing 5 is adapted to be connected to the source of first fluid 15 , in this case the exhaust port of an internal combustion engine. The first fluid 15 enters the housing through entrance 16 and is directed through catalyst assembly 10 then out exit 17 .
[0011] The housing 5 comprises an exterior surface 19 with a partition 35 extending outwardly therefrom. The partition 35 is positioned such that a second fluid 8 flowing toward the downstream face 11 of catalytic assembly 10 will be deflected away from the downstream face 11 .
[0012] Within housing 5 , baffle 30 is positioned outwardly from the interior surface 18 to direct the first fluid 15 flow toward catalytic assembly 10 .
[0013] [0013]FIG. 2 shows the apparatus of FIG. 1 mounted on a target 60 , in this case an aerial drone. The apparatus is connected to an engine 61 such that the first fluid 15 , in this case the exhaust from the engine, causes the catalytic assembly to radiate. Catalytic assembly 10 is positioned in the exit 17 such that the generated radiation 75 is visible to a distant observer 70 . FIG. 2 also shows that the engine 61 is integrated into the propulsion system, attached to a propeller 62 , of the target 60 .
[0014] [0014]FIG. 3 shows another view of target 60 to illustrate that multiple catalytic assemblies 10 can be employed.
[0015] [0015]FIG. 4 shows a schematic representation from the distant observer's perspective. The device is intended as an IR source that can be acquired by a sensor that is part of a weapon (not shown). The sensor is manipulated by the distant observer 70 . Thus an irradiance 71 at the location of the sensor, assumed to the distant observer 70 , must be sufficient for the sensor to detect.
DETAILED DESCRIPTION
[0016] The catalytic assembly 10 is comprised of at least one element 50 with a catalyst 51 positioned thereon. As those skilled in the art will recognize, there are numerous structures for element 50 as well as numerous catalyst for catalyst 51 and still further numerous ways of positioning the catalyst on the element. Element 50 must be capable of radiating, elements providing greater emissivity are preferred. In the case of the present invention, a metallic, short channel element, woven metal 10×10 mesh constructed of Haynes 230, was used. Other element structures such as expanded metal, gauze, foam, or monolith constructed of almost any material including metals or ceramics could be used.
[0017] It is preferred that the shape of the material chosen for element 50 , or most downstream element 50 in the case where multiple elements 50 are employed, provide a radiation pattern off the downstream face 11 in more than a single direction. An element 50 is comprised of members 52 , in this case wire woven into a mesh. Wire has a round cross-section that generates a hemispherical radiating pattern off the downstream face 11 . If the shape of the members at the downstream face were planar, a typical monolith, the members 52 would generate a radiation pattern in a single direction. It would be possible, however, to use members 52 with cooperating planer surfaces to generate a multi-directional radiation pattern. For example, two planar surfaces oriented at an acute angle to one another.
[0018] Depending upon the element chosen and the application, a single or multiple element catalytic assembly might be devised. The most downstream surface of the most downstream element 50 , based on the flow of the first fluid through the catalyst assembly, is defined as the downstream face 11 . In the case of a multiple element 50 catalytic assembly, it is preferred that the members 52 of respective elements 50 be offset to one another relative to the flow of the first fluid 15 through the catalytic assembly.
[0019] The catalyst 51 is application dependent, depending upon the composition and operating conditions of the first fluid 15 in combination with the weapon sensor and the range on which the target will be used. The catalyst must be positioned on the element, or elements, such that the catalytic assembly 10 when contacted with the first fluid 15 radiates. Positioning could be accomplished through any number of commonly used deposition techniques or integrated into the composition of the element. In the case of the present embodiment wherein the first fluid 15 is the exhaust gas of an internal combustion engine, any precious metal catalyst, such as platinum or palladium, could be used.
[0020] While this embodiment depicts the first fluid 15 as an exhaust gas of an internal combustion engine, this should not be considered a limitation of the invention. It is preferred that the invention utilizes a first fluid 15 that is presently available onboard the target, the exhaust gas or a fuel. The present invention, however, will function as intended if the first fluid is ancillary to the target, for example a bottled fuel. In addition, it is anticipated that other engines, other than internal combustion, may be used to generate the second fuel 15 .
[0021] The housing 5 is the structure that holds the catalytic assembly 10 in the housing's exit 17 . The design of exit 17 is application dependent, but it is preferred that the opening be sized to permit the maximum exposure of the catalytic assembly 10 downstream face 11 to a distant observer. It should be realized, that the housing can be adapted to the first fluid source with multiple entrances 16 . The material selected for the housing is application dependent.
[0022] A partition 35 extends outwardly from the housing 5 exterior surface 19 . Where the target is moving, such as in the depicted aerial drone, the catalyst assembly 10 could be cooled by a second fluid 8 passing over the surface. It is preferred that the partition 35 be located upstream of the downstream face 11 , relevant to the flow of fluid 8 , to prevent as much as possible this cooling effect, in the presented embodiment thereby defining a partition angle 36 that is acute. The partition 35 also has an overhang 9 that extends beyond the width of the downstream face 11 to account for non-parallel second fluid 8 flow patterns.
[0023] When the housing 5 is adapted to be in fluid communication with the source of the first fluid, the passage created by the housing may have turns. In order to assure maximum utilization of the catalyst 51 , it is preferred that the first fluid be distributed equally throughout the catalyst assembly 10 . In the present embodiment, baffle 21 extends outwardly from the interior surface 18 of housing 5 to accomplish this objective. When baffle 21 is performing this function, as depicted in this embodiment, it is preferred that the baffle in cooperation with the downstream face define a baffle angle 22 that is acute. Baffle 21 , however, might be employed to simply reduce the pressure drop between entrance 16 and exit 17 . The shape and positioning of the baffle is based on the application, but in the preferred embodiment that baffle was given a fair surface and the surface was given a parabolic shape.
[0024] In the method of the present invention, the catalytic assembly 10 is engineered such that the catalyst 51 cooperates with the first fluid 15 to create a radiation 75 . The amount of radiation 75 required is dependent upon the sensor being used and the parameters of the range such as distance from sensor, which is illustrated herein as the distance from observer 70 to the target. The first fluid can either by a fluid onboard the target, exhaust gas or fuel, or from an ancillary source added to the target. To provide additional benefit to the observer by illuminating the target from multiple perspectives, multiple exits 17 each with a catalyst assembly 10 can be positioned at different locations on the target. | The invention is an apparatus for producing an IR (infra-red) signature. In the method, the apparatus is mounted on a target to give the target an infra-red signature whereby the target can be acquired by an appropriate weapon sensor. | 5 |
This is a continuation of application Ser. No. 850,497, filed Nov. 11, 1977 now abandoned.
BRIEF SUMMARY OF INVENTION
In order to concentrically support a roll or workpiece having an internal bore on a fluid-expanded mandrel or internal chuck, despite looseness between said bore and the external supporting surfaces areas of the mandrel or internal chuck, it is necessary to spread the looseness uniformly about the bore, despite the tendency for the roll or workpiece and the mandrel or internal chuck to hang eccentrically, with respect to each other, when first assembled.
Concentricity is achieved by driving the expanding members outwardly by means of very stiff springs, which are, in turn, driven outwardly a fixed and equal amount, by fluid actuated means. The stiffness of the springs is so great that their relative deflection by the weight of any part involved is negligible. The eccentricity which results upon first assembly is removed, by the lifting up, against the force of gravity, of the downwardly hanging part, when the fluid actuated means drives the springs outwardly.
The use, in a correspondingly inverted manner, of very stiff springs to drive inwardly the jaws of an external chuck, permits concentric chucking of workpieces which do not have an internal bore.
VIEWS OF THE DRAWINGS
FIG. 1 is a perspective view of a roll of sheet material with an expanding mandrel threaded through the core;
FIG. 2 is a cross-sectional view of a prior art air-expanding mandrel;
FIG. 3 is a cross-sectional view of an air-expanding mandrel in accordance with the invention;
FIGS. 4, 5 and 6 are, respectively, a partly exploded longitudinal view of a commercial embodiment of an air-expanding mandrel and two cross-sectional views thereof;
FIG. 7 is a partly exploded cross-sectional view of an air-expanding internal chuck; and
FIG. 8 is a cross-sectional view of an air-contracting external chuck.
DETAILED DESCRIPTION
A specific environment in which the invention is useful is one in which sheet material is unrolled at an input end of a sheet material processing machine and rolled up at the output end. If the machine is run so that the sheet material is fed through at a constant linear speed, the rotational speed of the input and output rolls will be very high at the end and start, respectively, of the run.
Unbalance of said rolls, caused by eccentric mounting, causes vibration which can damage the equipment and must be controlled by reducing the speed of the machine.
To explain how eccentric mounting can occur, reference is made to FIG. 1 which shows a roll of sheet material 17 resting on the floor, with an mandrel 10 (called a shaft in the industry) loosely placed inside the fiber core 18 on which the sheet material is wound. It will be noted that the shaft 10 is provided with outer leaves 13 which can be expanded against the internal bore 19 of core 18 so that the roll 17 can be supported by shaft 10. The looseness or clearance between shaft 10 and the bore 19 is grossly exaggerated in the drawing, for purpose of exposition. In actual practice, the shaft 10 will have a clearance of only about 1/16 inch for a 3 inch internal diameter core. This amount of clearance permits easy insertion of the shaft 10 in roll 17, and reduces the required range of expansion of the outer leaves 13.
FIG. 2 shows what happens when the bladder 16 of shaft 10 is pressurized to clamp shaft 10 inside the bore 19.
The bladder 16 bears against the inner leaves 12, driving them outwardly, thereby pushing out the spacing collars 15, which project through holes in the main body 11 of shaft 10 and the spacing collars 15 drive outwardly three of the four outer leaves 13. The fourth bottommost leaf 13 is not driven outwardly, but stays in contact with the main body, as shown at 23, because the outward force from bladder 16 is equal on all leaves 13, and only the bottommost leaf is restrained by the weight of shaft 10, from separating from the main body 11.
FIG. 2 shows the leaves 13 fully expanded within the bore 19, with the shaft 10 eccentric with respect to bore 19, as shown by the zero clearance at 23 and the large clearance on the diametrically opposite side at 21.
It will be noted from FIG. 2 that, when the bladder is fully expanded, there is everywhere a clearance 22 between the outside of the inner leaves 12 and the inside of the main body 11. That is, the inner leaves 12 do not bottom on the inside of main body 11 when the bladder 16 is fully expanded. Thus, the force of the bladder 16 is completely transmitted to the outer leaves and the extent of outward motion is determined only by the size of internal bore 19. If bottoming did take place, the further outward motion of the outer leaves 13 would be halted and they could no longer grip the internal bore 19 with proper force.
The instant invention is a departure from the prior art just discussed in that bottoming of the inner leaves is desired and very stiff springs connect the inner and outer leaves, to transmit the outward force from inner leaf to outer leaf, while yet accommodating slight differences in the internal diameters of the cores of different rolls. The springs are sufficiently stiff so that relative deflections of different ones of the several springs, because of the weights of the parts involved, is negligible. Thus, substantial concentricity is achieved.
FIG. 3 is a cross-section of one embodiment of the invention, with features exaggerated to show the construction. In the figure the shaft 30 is shown with the outer leaves 33 expanded against the inner bore 19 of a roll core. It will be noted that, in contrast to the embodiment of FIG. 2, the inner leaves 32 are bottomed out against the inner bore of the main body 31, there being no clearance comparable to the clearance 22 of FIG. 2. Furthermore, the outer leaves 33 are not fixedly spaced from the inner leaves 32, as in FIG. 2, but the outer and inner leaves 33 and 32 are, instead, held apart apart a variable distance by very stiff cup washers 41.
Cup washer 41 compresses to a variable extent, when shaft 30 is used in different cores, to accommodate the slight variation of actual core size among a set of cores of nominally identical size. However, cup washer 41 is not very limber. Instead, it is so stiff that difference in deflection of the topmost cup washer 41, and the bottommost cup washer 41, caused by the weight of the shaft 30 as it lies in the roll after expansion of bladder 36, is negligible.
In a typical core-shaft combination, the total radial clearance (both sides summed) between a nominal 3 inch core and an unexpanded 3 inch shaft would be about 0.04 inches. This is enough to permit easy insertion of the shaft into the core. With the prior art shaft of FIG. 2, the resulting radial eccentricity would be about 0.02 inches. With the improved shaft of FIG. 3, the radial eccentricity is reduced to any desired amount, depending on the choice of the stiffness of the cup washers. That stiffness is limited only by the bursting and crushing strength of the core, and by the variance in actual core sizes within the nominal size. If all the cores are sized exactly alike, the cup washers could be tailored to exert maximum safe pressure when both the inner and outer leaves are fully seated. If some cores are smaller and some larger, the cup washers must not be so stiff as to damage the smallest core when both the inner and outer leaves are fully seated. The range of expansion in larger cores is determined by the requirement that the outer leaf must push against the core with sufficient force to prevent slipping between shaft and core. In actual practice, the parts are sized so that the cup washer, of the Belleville type, is deflected to about 75% of full rated load for properly sized cores.
In the prior art embodiment of FIG. 2, the inner and outer leaves 12, 13 are fastened together, so that the outer leaf 13 cannot fall off the shaft 10. However, as shown in FIG. 3, the outer leaf 33 is not fastened to the inner leaf 32, so that the outer leaf 33 could fall off. The inner and outer leaves 32,33 cannot be fastened to each other, as a fastening would defeat the purpose of cup washers 41. Accordingly, a lost motion connection is established between the inner and outer leaves, in order to hold the outer leaves captive. This lost motion connection will be explained in connection with FIGS. 4, 5 and 6, which disclose a commerical embodiment, with the bladder deflated.
Shaft 60 includes a main body tube 61 mounted on stub shafts 62, which are machined at their outer ends to provide journal surfaces 64 and 65, concentric with the outer surface of main body tube 61. These parts are held assembled by set screws 66.
Shaft 60 also includes inner and outer leaves 72 and 73. Each outer leaf is connected to its corresponding inner leaf by a number of push nut connections, as shown in FIG. 5 and by at least two loose-play hold-back connections as shown in FIG. 6. The connections in each case include a flat head socket cap screw 74 screwed into either a push nut 75 (FIG. 5) or a captive nut 77 (FIG. 6).
Separating the inner end of the push nuts 75 and the outer face of the inner leaves 72 are the cup washers 71, so that when the bladder 76 inflates and bottoms the inner leaves 72 against the inside of main body tube 61, the outer leaves 73 are forced outwardly by means of the outward push of cup washers 71.
On the other hand, the captive nuts 77, which have an enlargement at their radially inner ends and have a loose fit connection with the holes of the inner leaves 72 through which they pass, prevent the inner and outer leaves 72,73 from separating by more than a fixed amount. Thus, the captive nut connections prevent the outer leaves 73 from falling off.
A shop-line air hose connection 78 is provided for inflating bladder 76. The connection is a rotary joint type. A side entry joint can be used where the period of use is short and the air in the bladder will retain its pressure. In actual practice, 60 pounds/square inch is used to completely seat the inner leaves and thereby thrust the outer leaves against the inner bore of the cardboard core. Even with slightly undersized cores, this resulting spring pressure is not sufficient to injure a 3" core.
A pilot sleeve 79 is provided at each end of shaft 60 so that the external surface of the shaft 60 is smooth, when the outer leaves are retracted. This makes the loading of shaft 60 into a roll easier.
The outer leaves in the embodiments of FIGS. 4 to 6 are held captive but are nonetheless loose. If desired, in order to make insertion of the shaft 60 into a roll easier, retracting springs can be inserted into spaces such as marked A in FIG. 6, to withdraw the outer leaves when the bladder 76 is deflated. Such springs must be provided with clearances, so as not to interfere with the seating of the outer surface of inner leaves 72 on the inner bore of main body tube 61.
Another embodiment of the invention is an expanding chuck for holding workpieces during a machining operation. Chuck 80 of FIG. 7 is a single ended chuck rather than a double ended mandrel. It includes a main body 81 which is mounted on the machine spindle by chuck adapter 82. The expanding chuck includes inner and outer leaves 92 and 93. Flat head screws 94 and push nuts 95 cooperate with cup washeres 91 to transmit the outward push from inner leaf 92 to outward leaf 93. The outer leaves will not fall off because the cup washers 91 are captive to the short stubs 96 which extend inwardly from the push nuts 95. For example only, the cup washers could be staked to the short stubs 96. The rubber boot 86 can be inflated either by air or by hydraulic fluid. It is to be noted that many machines in the machine shop are provided with pressurized fluid spindles, either for actuating chucks, or for operations such as gun drilling. Accordingly, a fluid expanding chuck has widespread utility.
In a typical fluid expanding chuck, adapted for chucking a workpiece, such as a roll, with a 6 inch diameter bore 5 inches long, at 80 pounds per square inch air pressure, the chuck can concentrically support such a roll weighing 3,200 pounds and turn it with a slip-free torque of 3,500 inch pounds.
The inventive concept is also applicable to an internal air-contracted chuck, wherein the parts of FIG. 7 are turned inside out, as shown in FIG. 8. The operation of the chuck of FIG. 8 need not be explained, since its construction and operation will be evident from what has preceded.
As will be understood by those skilled in the art, the outer leaves can be replaced by smaller area lugs, ribs or buttons, which will, because of their smaller area, indent the inside bore of a core, and therefore afford a greater slip-free torque. | A fluid actuated expanding mandrel or internal chuck is provided with means including very stiff springs to cause the expanding members to move outwardly a substantially equal amount, whereby a roll or workpiece is concentrically mounted, despite looseness between the bore of the roll or workpiece and the mandrel or internal chuck. A correspondingly inverted arrangement affords concentric chucking on the outer diameter of solid workpieces. | 8 |
TECHNICAL FIELD
[0001] The present invention relates to a pile foundation for placing a structural object, and particularly, to a pile foundation and a pile foundation installation method suitable for a soft ground.
BACKGROUND ART
[0002] Conventionally, a structural object, such as a solar panel and a house, is placed on a foundation installed on the ground surface in order to be always level with the ground. However, the structural object or the like and the foundation may be sedimented or tilted due to their weights when the ground for installing the structural object or the like is a soft ground, such as a wetland and a peatland.
[0003] Consequently, proposed is an invention related to a pile foundation that prevents sedimentation or tilt of a structural object or a foundation on a soft ground by fixing the foundation to the ground surface by driving a plurality of driving piles.
[0004] For example, the specification of U.S. Pat. No. 5,039,256 proposes a pile foundation including a cylindrical body filled with concrete or cement and including a plurality of driving piles penetrating through the cylindrical body (Patent Literature 1). According to Patent Literature 1, the pile foundation can be carried and reused as a foundation of another structural object after removal of the structural object or the like.
CITATION LIST
Patent Literature
[0005] Patent Literature 1: U.S. Pat. No. 5,039,256
SUMMARY OF INVENTION
Technical Problem
[0006] However, concrete is used as a material of the pile foundation in the invention described in Patent Literature 1. Therefore, in a cold region where the ambient temperature becomes below 0 degrees Celsius, the moisture contained in the concrete may be frozen, and the moisture may expand. The concrete may be cracked or ruptured, and this so-called frost damage may occur. Furthermore, the weight of concrete is large, and the transportation cost is high. The transportation work and the construction work become heavy labor and burdensome. Furthermore, much time is required from filling to solidification of concrete, and the manufacturing efficiency is low. The pile foundation is not suitable for mass production, and it is difficult to reduce the manufacturing cost. Therefore, an improvement is highly demanded.
[0007] On the other hand, when a light, inexpensive steel material or the like is used to manufacture the pile foundation without using the concrete material, the thermal conductivity is high, and the ambient temperature is easily transmitted to the ground through the steel material. Therefore, for example, when the ambient temperature is below 0° C. degrees, the cold air is transmitted to the ground. The moisture in the ground is frozen, and ice layers are formed, causing the soil to rise. This so-called frost heaving phenomenon occurs. The frost heaving phenomenon causes a problem of pushing up or tilting the pile foundation, thereby tilting and damaging a structural object placed on the pile foundation.
[0008] The present invention has been made to solve the problems and the like, and an object of the present invention is to provide a pile foundation and a pile foundation installation method that can facilitate and reduce the cost of manufacturing and transportation of structural members as well as construction work at the site, thereby enabling mass production and various cost reductions and enabling to effectively take countermeasures for frost damage and frost heaving.
Solution to Problem
[0009] The present invention provides a pile foundation supported on a ground surface by a plurality of driving piles, for placing a structural object on top, the pile foundation including a pile foundation body including: a lower plate disposed on a bottom side; an upper plate disposed on a top side; and a support post that supports the lower plate and the upper plate substantially parallel at a predetermined interval, wherein the lower plate and the upper plate are provided with a plurality of pile holes through which the driving piles penetrate downward in a substantially radial pattern.
[0010] In an aspect of the present invention, the pile foundation body may include a thermally insulated pyramid-shaped frost heaving prevention pyramid on a bottom surface of the lower plate, an apex of the frost heaving prevention pyramid facing downward.
[0011] In an aspect of the present invention, the frost heaving prevention pyramid may be formed in a polygonal pyramid shape, and the pile hole may be formed on each side surface of the frost heaving prevention pyramid.
[0012] In an aspect of the present invention, the pile foundation body may include a sedimentation suppression plate formed with a greater dimension to the outside than the lower plate, the sedimentation suppression plate provided on the lower plate.
[0013] In an aspect of the present invention, a plurality of the support posts of the pile foundation body may support outer edges between the upper plate and the lower plate.
[0014] In an aspect of the present invention, the support post of the pile foundation body may be formed in a rectangular solid shape and disposed at a center, and four angle steels of a same type may be used for each of the lower plate and the upper plate to surround and fix four upper side surfaces and four lower side surfaces of the rectangular-solid support post to form a substantially rectangular frame shape.
[0015] The present invention provides a pile foundation installation construction method of inserting the plurality of driving piles into the pile holes from the upper plate to the lower plate in the pile foundation body to drive the plurality of driving piles into a ground in a substantially radial pattern to install the pile foundation.
Advantageous Effects of Invention
[0016] According to the present invention, the manufacturing and transportation of a structural member as well as construction work at the site can be facilitated and inexpensive, thereby enabling mass production and various cost reductions and enabling to effectively take countermeasures for frost damage and frost heaving.
BRIEF DESCRIPTION OF DRAWINGS
[0017] FIG. 1 is a perspective view showing a first embodiment of a pile foundation according to the present invention.
[0018] FIG. 2 is an enlarged perspective view showing a pile foundation body according to the present first embodiment.
[0019] FIG. 3 is an enlarged perspective view showing a frost heaving prevention pyramid according to the present first embodiment.
[0020] FIG. 4 is a side view showing a state in which the pile foundation of the present first embodiment is installed on the ground.
[0021] FIG. 5 is a perspective view showing a second embodiment of the pile foundation according to the present invention.
[0022] FIG. 6 is an enlarged perspective view showing a pile foundation body according to the present second embodiment.
[0023] FIG. 7 is an assembly diagram showing a pile foundation body according to the present second embodiment.
DESCRIPTION OF EMBODIMENTS
[0024] Hereinafter, a first embodiment of a pile foundation and a pile foundation installation construction method according to the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 4 , a pile foundation 1 a according to the present first embodiment mainly includes: a pile foundation body 2 a installed on a ground surface F; and a plurality of driving piles 3 driven into the ground to support the pile foundation body 2 a . Hereinafter, each component will be described in detail.
[0025] The pile foundation body 2 a is supported on the ground surface F, such as a soft ground, to enable placing a structural object O on top. As shown in FIGS. 1 to 4 , the pile foundation body 2 a of the present first embodiment includes: a lower plate 21 a disposed on the bottom side; an upper plate 22 a disposed on the top side; a plurality of support posts 23 a that support the lower plate 21 a and the upper plate 22 a substantially parallel at a predetermined interval; a frost heaving prevention pyramid 4 arranged on the bottom surface of the lower plate 21 a ; and a sedimentation suppression plate 5 formed to be larger than the lower plate 21 a.
[0026] The lower plate 21 a is disposed on the bottom side of the pile foundation body 2 a and formed in a rectangular shape. In the present first embodiment, the lower plate 21 a is formed by a substantially square-shaped plate material. The lower plate 21 a includes a plurality of pile holes 24 formed in an elliptical shape in order to insert the plurality of driving piles 3 in a substantially radial pattern.
[0027] The upper plate 22 a is disposed on the top side of the pile foundation body 2 a , substantially parallel to the lower plate 21 a , and is formed in a rectangular shape. In the present first embodiment, the upper plate 22 a is formed by a substantially square-shaped plate material just like the lower plate 21 a . A plurality of pile holes 24 are formed in an elliptical shape on the upper plate 22 a in order to insert the plurality of driving piles 3 in a substantially radial pattern. The positions of the pile holes 24 of the lower plate 21 a and the pile holes 24 of the upper plate 22 a in the vertical direction are shifted to adjust the driving angles of the driving piles 3 , and the driving piles 3 penetrate in a radial pattern. Common components can be used for the lower plate 21 a and the upper plate 22 a , and the production cost can be reduced by reducing the types of components constituting the pile foundation body 2 a . In the present first embodiment, bolts for fixing the structural object O placed at the upper center position of the upper plate 22 a are attached.
[0028] The shape of the lower plate 21 a and the upper plate 22 a is not limited to the rectangular shape, and one of a triangular shape, a polygonal shape with five or more sides, a circular shape, and the like may be appropriately selected. The material used for the lower plate 21 a and the upper plate 22 a is not particularly limited, and it is desirable to appropriately select a material, such as a hot-dip galvanized steel material, a stainless steel material, and a reinforced plastic material, with rigidity for supporting the structural object O and with appropriate corrosion resistance to oxidization, ultraviolet rays, and the like, because the material is to be exposed to the outside for a long time.
[0029] The support posts 23 a support the lower plate 21 a and the upper plate 22 a substantially parallel at a predetermined interval. As shown in FIGS. 1 and 2 , the support posts 23 a according to the present first embodiment are four substantially columnar bars fixed by bolts at four corners of each of the lower plate 21 a and the upper plate 22 a , the four corners being outer edges of the lower plate 21 a and the upper plate 22 a.
[0030] The shape of the support posts 23 a is not limited to the substantially columnar shape, and one of a cylindrical shape, a prismatic shape, a square-tube shape, and the like is appropriately selected. Like the lower plate 21 a and the like, the material used for the support posts 23 a is appropriately selected from materials with rigidity and corrosion resistance, such as a hot-dip galvanized steel material and a stainless steel material.
[0031] Next, the frost heaving prevention pyramid 4 will be described. The frost heaving prevention pyramid 4 is made of a thermally insulated material and is arranged between the ground surface F and the lower plate 21 a as shown in FIGS. 3 and 4 to prevent cold air transmitted from the outside from being transmitted to the ground surface F and to the ground through the lower plate 21 a . Examples of the thermally insulated material include, but not limited to, chemical synthetic resin, such as plastic and synthetic rubber, natural rubber, ceramics, and FRP. Although the shape of the frost heaving prevention pyramid 4 is not particularly limited, the shape is a pyramid shape in the present first embodiment. The frost heaving prevention pyramid 4 is arranged on the bottom surface of the lower plate, with the apex facing downward. This is intended to install and insert the apex of the frost heaving prevention pyramid 4 into the ground surface F as shown in FIG. 4 to increase the installation surface with respect to the ground surface F for stable installation, even if there is some roughness on the ground surface F. Therefore, there is an advantage that leveling of the installation location is not required.
[0032] The frost heaving prevention pyramid 4 according to the present first embodiment is formed into a substantially quadrangular pyramid by a plastic material as shown in FIGS. 3 and 4 and is fixed to the bottom surface of the lower plate 21 a by bonding, bolting, or the like through a sedimentation suppression plate 5 described later. Each side surface of the frost heaving prevention pyramid 4 includes four pile holes 24 to communicate with the pile holes 24 arranged on the lower plate 21 a to insert the driving piles 3 .
[0033] The shape of the frost heaving prevention pyramid 4 is not limited to the substantially quadrangular pyramid, and the shape may be, for example, a triangular pyramid shape, a polygonal pyramid shape with five or more sides, or a conic shape. Although the frost heaving prevention pyramid 4 according to the present first embodiment is formed separately from the lower plate 21 a , the frost heaving prevention pyramid 4 may be formed integrally with the lower plate 21 a.
[0034] The sedimentation suppression plate 5 is a plate material largely widened outside with respect to the lower plate 21 a and is arranged on the lower plate 21 a , thereby increasing the installation area with respect to the ground surface F to function as a floating body and increasing the effect of suppressing the sedimentation of the pile foundation 1 a . Although the sedimentation suppression effect increases with an increase in the size of the sedimentation suppression plate 5 , the level of the strength of the ground, the strength of the sedimentation suppression plate 5 , the cost, and the like are taken into account to determine the size. The sedimentation suppression plate 5 according to the present first embodiment is placed between the lower plate 21 a and the frost heaving prevention pyramid 4 as shown in FIG. 4 .
[0035] Although the sedimentation suppression plate 5 according to the present first embodiment is formed separately from the lower plate 21 a or the frost heaving prevention pyramid 4 , the arrangement is not limited to this. The sedimentation suppression plate 5 may be formed integrally with one or both of the lower plate 21 a and the frost heaving prevention pyramid 4 .
[0036] Next, the driving piles 3 will be described. The driving piles 3 have a columnar shape, a cylindrical shape, a prismatic shape, a square-tube shape, or the like and are made of elongated bars with a predetermined length. The driving piles 3 are inserted to the pile holes 24 arranged on the pile foundation body 2 a and driven into the ground to support the pile foundation body 2 a on the ground surface F. The plurality of driving piles 3 according to the present first embodiment include four driving piles 3 as shown in FIGS. 1 and 2 .
[0037] The shape, the length, the number, and the like of the driving piles 3 are not limited to the four cylinders illustrated in the present first embodiment, but are appropriately selected according to the shape and the size of the pile foundation body 2 a , the shape and the weight of the structural object O to be mounted, the softness level and the strength of the ground for installation, and the like.
[0038] Next, action of each component in the pile foundation 1 a of the present first embodiment will be described along with the pile foundation installation method according to the present first embodiment.
[0039] First, although the pile foundation body 2 a according to the present first embodiment may be assembled in a factory, the pile foundation body 2 a can be easily assembled by bolts and nuts. Therefore, the constituent members can be transported to a pile foundation construction site and assembled at the site. The transportation space of the constituent members is small, and the constituent members can be easily managed. Therefore, the manufacturing cost, the transportation cost, and the management cost can be reduced.
[0040] Next, the assembled pile foundation body 2 a is placed on the ground surface F, with the frost heaving prevention pyramid 4 facing downward as shown in FIG. 4 . In this case, the apex of the frost heaving prevention pyramid 4 can be installed and inserted into the ground surface F to increase the installation area with respect to the ground surface F for stable installation, even if there is some roughness on the ground surface F. Therefore, leveling of the ground surface F to form a plane surface is not required, and this reduces the construction term and the cost.
[0041] Next, the driving piles 3 are inserted into the pile holes 24 from the upper plate 22 a to the lower plate 21 a and to the frost heaving prevention pyramid 4 , and the driving piles 3 are driven into the ground in a substantially radial pattern. Although it is desirable to drive the driving piles 3 into the hard ground below the soft ground if the ground is a soft ground, the sedimentation suppression plate 5 suppresses sedimentation and tilt of the pile foundation 1 a even if the driving piles 3 cannot be driven into the ground with sufficient strength. Specifically, the sedimentation suppression plate 5 resists the sedimentation because the installation area with respect to the ground surface F and the underground is wide, and large buoyance is generated in a soft ground close to liquid. Therefore, the resistance to the sedimentation and the buoyance of the sedimentation suppression plate 5 can suppress the sedimentation of the entire pile foundation 1 a and the structural object O placed on the pile foundation 1 a.
[0042] The sedimentation suppression and the buoyance of the sedimentation suppression plate 5 can be appropriately adjusted by changing the size of the sedimentation suppression plate 5 . Therefore, when the load on the plurality of pile foundations la varies due to the weight balance according to the parts supporting the structural object O or due to wind pressure on the structural object or when the softness level of the ground varies due to the installation location, the size of the sedimentation suppression plate 5 can be appropriately adjusted to control the amount of sedimentation and the sedimentation speed to suppress the tilt of the mounted structural object O.
[0043] Since the frost heaving prevention pyramid 4 is made of a thermally insulated material, the heat of the air is not easily transmitted to the soil, and the effect of frost heaving in a winter term in a cold region, such as Hokkaido, can be suppressed.
[0044] Since the pile foundation body 2 a according to the present first embodiment is formed by a material with corrosion resistance, adverse effects caused by frost damage or rust can be prevented.
[0045] Furthermore, after the installation of the pile foundation la of the present first embodiment, the driving piles 3 can be pulled out from the ground to move or reuse the pile foundation body 2 a . The pile holes 24 in the frost heaving prevention pyramid 4 are formed so that the driving piles 3 penetrate through the side surfaces. Therefore, when the driving piles 3 are pulled out, the driving piles 3 can be easily pulled out without being caught on the side surfaces of the frost heaving prevention pyramid 4 .
[0046] The following effects can be obtained according to the pile foundation 1 a and the pile foundation installation method of the present first embodiment.
1. The number of components is small, and an expensive mold is not necessary. Therefore, manufacturing is easy, and the manufacturing cost can be reduced. 2. The pile foundation body 2 a can be assembled at the installation site. Therefore, the transportation space can be small, and the transportation cost and the installation cost can be reduced. 3. Problems of frost damage and frost heaving when the pile foundation 1 a is installed in a cold region can be suppressed, and long-term stable use is possible. 4. The pile foundation 1 a can be easily installed on a soft ground or on a land without leveling of ground, and the structural object O, such as a solar power system, can be installed. 5. Sedimentation caused by the weight of the structural object O can be effectively suppressed. 6. Work of pulling out the driving piles 3 after the installation is easy, and the pile foundation 1 a can be easily exchanged or reused.
[0053] Next, a second embodiment of the pile foundation according to the present invention will be described with reference to the drawings. In a pile foundation 1 b of the present second embodiment, the same or corresponding components as those of the first embodiment are designated with the same reference signs, and the description will not be described again.
[0054] As shown in FIGS. 5 to 7 , the pile foundation 1 b of the present second embodiment includes: a pile foundation body 2 b installed on the ground surface F; and the plurality of driving piles 3 driven into the ground to support the pile foundation body 2 b . The pile foundation body 2 b according to the present second embodiment includes: a lower plate 21 b disposed on the bottom side; an upper plate 22 b disposed on the top side; a support post 23 b disposed at the center to support the lower plate 21 b and the upper plate 22 b substantially parallel at a predetermined interval; and the frost heaving prevention pyramid 4 arranged on the bottom surface of the lower plate 21 b.
[0055] As shown in FIGS. 5 to 7 , the support post 23 b is formed in a rectangular-solid shape and disposed substantially at the center of the pile foundation body 2 b . The support post 23 b according to the present second embodiment is formed by a square tube to reduce the weight and to increase the rigidity. Hot-dip galvanization, stainless processing, or the like is applied to the support post 23 b to increase the corrosion resistance.
[0056] When the strength of the rectangular-solid support post 23 b is insufficient, the support post 23 b may be reinforced by diagonal plate materials or bars in the square tube, or the support post 23 b may be formed by a prism, although not shown.
[0057] Next, the lower plate 21 b and the upper plate 22 b according to the present second embodiment are formed by combining four angle steels 25 of the same type in a frame shape. More specifically, the angle steels 25 are disposed in a substantially rectangular frame shape to surround four upper side surfaces and four lower side surfaces of the rectangular-solid support post 23 b and are fixed by bolts, nuts, or the like as shown in FIG. 7 .
[0058] Each of the angle steels 25 is provided with one pile hole 24 for inserting one driving pile 3 . Four angle steels 25 constituting the lower plate 21 b and four angle steels 25 constituting the upper plate 22 b are arranged to be vertically symmetrical as shown in FIGS. 5 to 7 . The pile holes 24 of the lower plate 21 b and the upper plate 22 b are shifted in the vertical direction, and the driving piles 3 penetrate in a substantially radial pattern.
[0059] A placing plate 26 provided with a plurality of bolts are fixed on top of the upper plate 22 b according to the present second embodiment, and the structural object O is connected on top of the pile foundation body 2 b.
[0060] According to the pile foundation 1 b of the present second embodiment, the following effects can be obtained in addition to the effects of the pile foundation 1 a of the first embodiment. The lower plate 21 b and the upper plate 22 b can be easily formed by combining the angle steels 25 of the same type. The support post 23 b according to the present second embodiment is disposed at the center of the pile foundation body 2 b , and the support post 23 b can be thick, which is advantageous in increasing the strength. Furthermore, the types of components are reduced, and the assembly is easy. Therefore, the manufacturing cost can be reduced.
[0061] The pile foundation according to the prevent invention is not limited to the embodiments, and changes can be appropriately made.
[0062] For example, although not shown, the length of the support posts can be adjustable to allow adjusting the tilt angles of the driving piles 3 .
REFERENCE SIGNS LIST
[0000]
1 a , 1 b pile foundations
2 a , 2 b pile foundation bodies
3 driving pile
4 frost heaving prevention pyramid
5 sedimentation suppression plate
21 a , 21 b lower plates
22 a , 22 b upper plates
23 a , 23 b support posts
24 pile hole
25 angle steel
26 placing plate
O structural object
F ground surface | [Problem] To provide a pile foundation and a pile foundation installation method for which the manufacturing to transporting of structural members and installation work at the site are simple and inexpensive, mass production and cost reduction are possible, and frost damage countermeasures and frost heaving countermeasures can be effectively performed. [Solution] A pile foundation ( 1 ), on top of which a structural object is placed, supported at the ground surface (F) by a plurality of batter piles ( 3 ), has a pile foundation body ( 2 ) comprising a lower plate ( 21 ) disposed on the bottom side, an upper plate ( 22 ) disposed on the top side, and a support post ( 23 ) for supporting the lower plate ( 21 ) and the upper plate ( 22 ), separated by a prescribed gap, to be substantially parallel. A plurality of piling holes ( 24 ), through which each of the batter piles ( 3 ) pass through in a downward direction in a substantially radial form, are formed in the lower plate ( 21 ) and the upper plate ( 22 ). | 4 |
BACKGROUND OF THE INVENTION
Door alarm apparatus of the propped-against type have been developed in the past. These apparatus are intended to be set up in front of a door, once the door has been closed, and have the feature that they are intended only for temporary installation, when the door is closed and not in use. This invention relates to such door alarm apparatus and more specifically to those apparatus adapted to hold or otherwise activate a handgun shaped alarm member.
Such apparatus in the past have taken principally two formats. The first is an apparatus wherein the activating member is jammed against the door and frictionally held in position with respect to the floor surface behind the door. Such frictional holding has been assured by usually a large frictional surface area of the apparatus in contact with the floor, or, alternately, has been assured by a wedging member digging into or otherwise scraping along the floor mounting ever increasing resistance as the door is opened thereagainst.
The second format includes the fixed mounting of the apparatus to the wall immediately adjacent the door.
These prior art teachings exhibit certain shortcomings which this invention hopes to overcome. Particularly, those which are permanently mounted to the wall area adjacent the door are undesirable as they are not readily removable when the door is in use. Those which wedge or frictionally act against with the floor are also undesirable as they may easily be knocked over or dislodged from their intended position by a child or pet who brushes against them. Moreover, they provide no precise fixed reference point with respect to the closed position of the door. Such latter type devices may be wedged tightly against the door in a first installation and not so tightly against the door in a second installation. Moreover, for those of this type which are propped or lean against the door the angle at which they are leaned against the door may vary from use to use.
It is important to develop such an easily removable alarm apparatus which is easily installed to a predetermined and fixed spatial frame of reference with respect to the closed door. This enables a precise adjustment of the trigger mechanism which assures uniform operation not generally available with prior devices. It is also desirable to provide such an apparatus with a secured anchorage which will prohibit the apparatus from being dislodged from its operational position by the movements of a child or a pet.
An object of this invention is to provide a threshold plate door alarm which alarm may be securely attached to the threshold plate in a predetermined and fixed spatial association with the closed door.
A second object of this invention is to provide such an apparatus which may be securely anchored in such predetermined position.
A third object of this invention is to provide such an apparatus which is easily removable from its installed position.
A further object of this invention is to provide an activator and carriage for communicating with and operating a handgunlike shaped audible alarm member.
SUMMARY OF THE INVENTION
The objectives of this invention are achieved in a threshold plate door alarm apparatus which may include a carriage component suitable for positioning and supporting a handgun-shaped audible alarm component. Extending outwardly from the carriage may be an anchoring hook which may by inserted into an anchoring receptacle permanently mounted on the inside of the threshold plate of a door. This hook may include a canted barb which may mate with a canted receiving hole in the anchor plate.
An activating rod may be wedged between the closed door and the activating trigger of the audible alarm component. This activating rod which is preferably interchangeable as to various predetermined lengths may be wedged against the door in the horizontal position and may exert a predetermined pressure against the trigger of the audible alarm component as a function of the fixed distance between the closed door and the trigger member of the audible alarm component, such pressure being determinative of the pressure and movement by the door necessary to set off the alarm.
DESCRIPTION OF THE DRAWINGS
The operation, advantages and structural features of the invention can easily be understood from a reading of the following detailed description of the invention in conjunction with the accompanying drawings in which like numerals refer to like elements, and in which:
FIG. 1 shows the assembled threshold plate alarm apparatus.
FIG. 2 is a detail of the anchor plate and the canted barb of the anchoring hook shown in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
A removable threshold plate door burglar alarm apparatus includes a carriage member 101, FIG. 1, which carriage member comprises a base plate 103 and a plurality of vertical supports 105. Vertical supports 105 have connected therebetween a plurality of horizontal supports 107 which horizontal supports 107 are positioned to cradle and securely hold a handgun-shaped audible alarm component 109.
Handgun-shaped alarm component 109 is wedged between the vertical and horizontal supports 105, 107 of the carriage 101 to be securely positioned with respect thereto. While the handgun alarm component 109 may be inserted into the carriage 101 from above and may have limited free movement forward with respect to this carriage 101, it is absolutely stopped and cradled from further movement with respect to the downward and backward directions.
Carriage 101 is positionable in close proximity to the threshold plate 111 of a closed door 113. The carriage base 103 rests upon the floor. An anchoring hook 115 extends outwardly from the carriage base 101 towards the door 113 in a generally horizontal direction. This anchoring hook 115 includes an extended canted barb portion 117 thereof.
Mounted on the inside slanting portion of the threshold 111 is a shallow anchor plate 119. This anchor plate 119, FIG. 2, includes a receiving hole 121 of a shape and dimensions for slidably receiving the canted barb portion 117 of the anchoring hook 115 for inhibiting movement of this barb 117 with respect to a direction away from the closed door 113, as well as, a direction laterally, left or right, with respect to the closed door 113.
An activating rod 123, FIG. 1, is wedged between the closed door 113 and a trigger portion 125 of the handgun-shaped alarm component 109. This activating rod is positioned with sufficient force to hold it essentially horizontally between the closed door 113 and the trigger member 125, having a shape at the trigger mating end for conformally mating with the trigger 125.
A flexible cap or bushing 127 is positioned over the door mating and on the activating rod 123. This cap is compressible efficiently to wedge the activating rod to its operating position without moving the trigger member 125 of the alarm component 109.
In operation, the alarm apparatus may easily be installed or removed from its position against the door 113. In the installed position it is securely anchored with respect to the threshold plate 111 and is not easily moved or jarred out of position by a bump or a vibration caused by running feet or the playful activity of children or pets. More importantly, the length of the anchoring hook 115 and its mating with the anchor plate 119 predetermines the position of the carriage base 103 on the floor with respect to the closed door 113. Therefore, the distance between the trigger member 125 and the closed door 113 is predetermined and constant from installation to installation. This provides for a predetermined and constant pressure exerted by the operating rod 123 and the compressed rod cap 127. The activating force and distance of movement by the door 113 is therefore predetermined for each installation.
While the apparatus described herein may have many embodiments existing within the thrust and scope of the invention with many of the various elements described above being constructed of a variety of materials, as an example, the elements set forth herein may be constructed of materials as follows. The carriage 101 including its base 103 and vertical and horizontal supports 105, 107 can be made of polyethylene, polypropylene, or polycarbonite "plastic" material of sufficient thickness and strength to support the handgun shaped alarm component 105 and securely hold this component against the trigger member 125 operating pressure. Handgun shaped audible alarm component 109 can be a diecast structure made of aluminum white metal, or other readily available material. A spring loaded anvil, light explosive cap, air percussion member or other mechanism may be employed for providing an audible alarm, which mechanism may be triggered by the physical movement of trigger member 125.
Anchor plate 119 is preferably constructed of metal such as brass or aluminum which may easily be anchored to the threshold plate 111 by means of wood screws. Anchor hook 115 including the canted barb 117 may also be made of metal such as brass, bronze or aluminum which will permit a narrow conformation while providing sufficient strength for the hook 115. The hook 115 may have a swedged or otherwise flat end which can be bolted, clamped or screwed to the carriage base 103. The manufacture of the hook 115 of metal will assure that the barb 117 which extends vertically downwardly from the essentially horizontal extension of the hook 115 and then is canted at an angle backwardly toward the carriage base 103 to lock into the receiving hole 121 of the anchoring plate 119 will have sufficient strength to resist operational stresses placed thereupon.
Anchor plate 119 receiving hole 121 includes a first bore extending orthogonally thereinto and a secondary bore extending at an angle into the sidewall of the first bore for receiving the canted barb 117.
Activating rod 123 may be made of polycarbonite or other high-strength plastic, or reinforced fiberglass or metal of sufficient diameter to eliminate a bending of the rod 123 under the force of the opening door 113. Rubber cap 127 may be made of butal rubber or other crushible resilient material.
The apparatus is inserted into the operating position by sliding the anchoring hook 115 and barb 117 downwardly and backwardly away from the door. Activating rod 123 is then wedged into position.
The carriage base 103, vertical supports 105 and horizontal supports 105 can be made of various sizes and with various spaces between members in order to support and cradle an audible alarm component 109 of different shapes and sizes. Each carriage 101 could be sized for a specific alarm component 109.
As with specifying the base 103, vertical supports 105 and horizontal supports 105 to be of various sizes, the activating rod 123 can be of any one of various predetermined lengths depending upon the dimensions of the carriage 101 components and of the alarm component 109 it is to be used with. Normally, the trigger engaging end of this activating rod 123 conforms to the shape of the trigger.
Alarm component 109 need not be made in the shape of a hand gun. While the aesthetic appearance of this component 109 may be altered the functional operation may be just as well satisfied by an alarm component 109 of another shape.
The structural dimensions of the carriage base 103, anchoring hook 115 and canted barb portion 117 as well as the materials of which they are made may play an additional role in providing security for the door. If the carriage base 103 is of a sufficient height to enable the hook 115 and barb portion 117 to intercept the door 113 as it swings open, they can act to impede or limit the amount of opening of the door 113 after the alarm 109 has been energized. This structure therefore provides a positive stop of the door motion prohibiting intrusion.
The structural strength of the base 103, anchoring hook 115, canted barb portion 117 and anchor plate 119 must be sufficient to resist an intruder under such design considerations. The length of the hook 115 determines the distance the door 113 swings open before engaging this mechanical stop.
Alternate embodiments of the invention described herein may be made without departing from the intent and scope of the invention presented. It is therefore the intent of this disclosure to act as an illustrative presentation of the invention and not to limit the subject invention to the precise embodiment provided herein. | A door alarm apparatus, for signaling when a door has been jimmied or otherwise set ajar, is provided having a member which may be propped or otherwise jammed against a door, this door being in the normally closed position, for activating an alarm connected to this member where the member may be positioned in a fixed and predetermined spatial relationship to the threshold plate of the door whereby an anchoring component part of the may slidably mate with an anchoring component affixed to the threshold plate. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to battery busbars and more particularly to battery busbars for use on underwater deep submergence batteries.
2. Description of the Prior Art
The conventional method of rendering deep submergence batteries impermeable to shorting agents is to semi-permanently encapsulate the bussing system within polyurethane. This encapsulated system exhibits several serious disadvantages. The tops of pressure compensated deep submergence batteries utilized to power submersibles have been exposed to battery electrolyte spilled or carried from the cells by vented gas. This carryover phenomena is encouraged by the rapid decompression experienced during the submersibles ascent. This electrolyte establishes electrically conductive paths to the battery's bussing system. Through these paths cell to cell shorts are established and resistance between the battery and seawater ground is often reduced below the minimal acceptable limit for continuing a mission. Even with extensive maintenance these grounds are only temporarily eliminated.
In addition, the polyurethane potted bussing also precluded or made extremely difficult maintenance procedures. It is highly desirable to jumper a single cell or several cells out of a battery circuit during maintenance when the cells state of charge is significantly out of balance with the rest of the battery. With the potted bussing system this procedure requires chipping of large sections of polyurethane and then jumpering the cell. After the charging, the potting must be repoured and allowed to cure. Similarly, when a cell was determined to be in need of replacement it required removing the polyurethane potting, replacing the cell and then repouring the potting and allowing it to cure. In either case, chipping the potting is a time consuming as well as a dangerous task. Repouring the potting and allowing time to cure is a time consuming task. In addition, most of the polyurethane compounds utilized have been identified as cancer suspect agents and therefore must be carefully handled in an approved manner. In shott, the utilization of polyurethane insulation makes maintenance and repair extremely difficult and time consuming and does not provide adequate insulation in the presence of battery electrolytes.
SUMMARY OF THE INVENTION
The present invention overcomes the disadvantages and limitations of the prior art by providing an improved intercell busbar. The present invention utilizes a bussing conductor having silver-plated copper pin terminations for carrying battery current with a minimal voltage drop. An elastomeric insulating molded material insulates the conductor. A flange seal held in abutting relationship to a battery terminal post by a plastic lock nut seals the connection between the elastomeric insulation and the battery cell top after connection of the intercell busbar to the battery.
Accordingly, one object of the present invention is to provide an improved quick-disconnect, intercell busbar for use on deep submergence batteries.
Another object of the present invention is to provide a completely self-contained underwater battery busbar system.
A still further object of the present invention is to provide an intercell busbar which is reliable in operation and inexpensive to manufacture.
Another object of the present invention is to provide an intercell busbar for use on deep submergence batteries which eliminates shorts caused by electrolyte contamination or seawater intrusion.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given here and after. A detailed description indicates the preferred embodiments of the invention and is 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 when considered in connection with the accompanying drawings in which like reference numerals designate like parts throughout the figures thereof and wherein.
It should be understood that the foregoing abstract of the disclosure is for the purpose of providing a non-legal brief statement to serve as a search scanning tool for scientists, engineers and researchers and is not intended to limit the scope of the invention as disclosed herein nor is it intended that it should be used interpreting or in any way limiting the scope or fair meaning of the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view illustrating a preferred embodiment of the invention.
FIG. 2 illustrates in a partial section view the embodiment of FIG. 1 connected to a pair of battery terminal posts.
FIG. 3 is a cross-sectional view of an alternative embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is an illustration of the overall system operation of the preferred embodiment. The quick-disconnect intercell busbar generally designated by the numeral 10 electrically interconnects battery cells 12 and 14. As shown in FIG. 2 battery cell 12 includes a terminal post 16 having an intercore 20 fabricated of electrically conductive materials surrounded by an electrically insulating layer 18. Core 20 contains an opening 22 therein adapted to receive termination 24 of busbar 10 in a butting relationship thereto. The outside surface 26 of electrically insulating layer 18 is threaded to accept lock nut 28 which is threaded on the inside surface 30 thereof.
Intercell busbar 10 carries the current flowing between battery cells 12 and 14 through a flexible conductor 32. The flexible conductor 32 is fabricated from an electrically conductive material such as copper, aluminum, etc. Conductor 32 is terminated at either end into silver-plated copper pins 24 and 34. A soft silver solder is used to make the connection between the pins 24 and 34 and the conductor 32 in order to reduce the resistance through the busbar 10. Pins 24 and 34 are designed to accept contact bands 36 and 38 which are respectively held in place by caps 40 and 42. The caps 40 and 42 may be secured in place by screws not shown if desired. The termination pins 24 and 34 with contact bands 36 and 38 attached thereto are adapted to plug or fit into female battery cell terminal post such that contact bands 36 or 38 abut intercore 20 within opening 22 thereby providing an electrical connection therebetween.
Electrical and waterproof insulation of conductor 32 is provided by elastomeric insulating material 44 molded around conductor 32. A flange seal 46 is molded integral to elastomeric insulating material 44 adjacent termination pins 24 and 34. Lock nuts 28 and 50 are disposed to abut the top surface of flange seals 46 and 48 and screw down onto the threaded portions of threaded plastic cell top extension 18 and 52. As shown in FIG. 2 lock cap or lock nut 28 is screwed down over the threaded portion of cell top extension 18 such that flange seal 46 is disposed in abutting relationship between lock nut 28 and cell top extension thereby effecting a watertight seal between female terminal post 16 and molded insulating material 44.
Monitoring of cell voltage is accomplished through a small conductor 60 which electrically connects conductor 32 to volt meter 62. Molded elastomeric insulating material section 64 provides the necessary strain relief for conductor 60. Conductor 60 is also electrically insulated.
Intercell busbar 10 is installed by pushing pin terminations 24 and 34 into female terminal posts 16 and 66 extending respectively outward from the two battery cells 12 and 14 to be connected in series or in parallel. The electrical connection between the battery cells 12 and 14 is thus established through the contact bands 36 and 38, the termination pins 24 and 34 and the conductor 32. The height of cell top extensions 18 and 52 are such that when the busbar 10 is mated with the female terminal posts 16 and 66 flange seals 46 and 48 abut the cell top extensions 18 and 52. Lock nuts 28 and 50 are then screwed down onto the threaded portion of cell top extensions 18 and 52 until flange seals 46 and 48 establish a seal between the bottom surfaces 70 and 72 and the top surfaces 74 and 76 of cell top extensions 18 and 52. When both lock nuts 28 and 50 are torqued down in this manner electrical isolation from the surrounding environment is complete and intercell busbar 10 is installed and ready for operation.
Now turning to FIG. 3, an alternate embodiment of the present invention is illustrated in cross section generally designated by the numeral 100. Busbar 100 consists of a elongated copper conductor 102 having openings 104 and 106 therethrough at opposite ends thereof. Molded elastomeric insulating material 108 surrounds conductor 102. Insulating material 108 contains openings 110 and 112 adjacent the top surface 114 of conductor 108 and openings 116 and 118 adjacent the bottom surface 120 of conductor 102. Openings 112, 106, 118 form a single path through busbar 100 while openings 110, 104 and 116 also provide a single path through busbar 100. Lips 122 and 124 are molded integral to insulating material 108 adjacent openings 116 and 118, respectively. Lips 122 and 124 include projections 130 and 132, respectively; configured to abut the outside surface of cell top extension 134 of terminal post 136 thereby providing a watertight seal therebetween. Plastic cell top extension 134 provides electrical insulation to conductor portion 138 of battery terminal post 136.
Silver plated contact disc 140 is disposed in abutting relationship to conductor 102 within opening 116. In its operational state, contact disc 140 is sandwiched in abutting relationship between conductor portion 138 of terminal post 136 and conductor 102 thereby providing an electrical path from battery cell 126 through multilam disc 140 through conductor 102 through contact disc 142 to the next battery terminal post.
Once intercell busbar 100 is emplaced with lip 122 in abutting relationship with terminal post 136, cover lid 146 is emplaced over opening 110. Cover lid 146 contains a downwardly extending threaded member 144 adapted to screw into terminal post 136. When tightened, cover lid 146 effects a pressure contact between conductor 102 multilam disc 140 and terminal post 136 and contact disc 140 thereby creating and maintaining an excellent electrical interconnection. In addition, cover lid 146 forms a waterproof seal between cover lid 146 and insulating material 108, thereby effecting complete isolation from the surrounding environment of the electrical path through busbar 100 from battery cell 126 to another battery cell (not shown). Likewise opening 112 of molded insulation 108 is covered with cover lid 150 having a downwardly extending threading member 152 for threaded engagement with a terminal post (not shown).
The molded elastomeric insulating material 44 and 108, lips 122 and 124, cover lid 146 and 150 as well as strain relief 64, may be fabricated from polychloroprene and chlorosulphonated polyethelene for successful operation. However, many other elastomers are equally well suited depending upon the ambient operating temperature and medium. The lock nuts 28 and 50 as well as cell top extensions 18 and 52 may be fabricated from polysulfone or polyvinylchloride materials among others. Again, other plastics are also suitable depending upon the operating temperature and surrounding environment.
Therefore, many modifications and embodiments of the specific invention will readily come to mind to one skilled in the art having the benefit of the teachings presented in the foregoing description and the accompanying drawings of the subject invention and hence it is to be understood that the invention is not limited thereto and that such modifications, etc., are intended to be included within the scope of the appended claims. | A quick disconnect intercell busbar for providing an easily removable, inidually insulated bussing system for deep submergence batteries. A bussing conductor having silver plated copper pin terminations carries battery currents with a minimal voltage drop. The busbar is insulated to provide sealing of the battery electrical circuits thereby eliminating shorts caused by electrolyte contamination or seawater intrusion. A low current conductor connected to the bussing conductor with suitable insulation provides for monitoring of cell voltages. | 7 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to thin film solar cell processing. More specifically, this invention relates to methods of forming copper indium gallium (sulfide) selenide (CIGS) solar cells, cadmium telluride (CdTe) solar cells, and copper zinc tin (sulfide) selenide (CZTS) solar cells using laser annealing techniques.
BACKGROUND OF THE INVENTION
[0002] Solar cells have been developed as clean, renewable energy sources to meet growing demand. Currently, crystalline silicon solar cells (both single crystal and polycrystalline) are the dominant technologies in the market. Crystalline silicon solar cells must use a thick substrate (>100 um) of silicon to absorb the sunlight since it has an indirect band gap. Also, the absorption coefficient is low for crystalline silicon because of the indirect band gap. The use of a thick substrate also means that the crystalline silicon solar cells must use high quality material to provide long minority carrier lifetimes to allow the carriers to diffuse to the junction. Therefore, crystalline silicon solar cell technologies lead to increased costs. Thin film solar cells based on amorphous silicon (a-Si), CIGS, CdTe, CZTS, etc. provide an opportunity to increase the material utilization since only thin films (<10 um) are generally required. CdTe and CZTS films have direct band gaps of about 1.5 eV and therefore, are efficient absorbers for wavelengths shorter than about 1100 nm. The absorption coefficient for CdTe is about 10 5 /cm and the absorption coefficient for CZTS is about 10 4 /cm. CIGS films have direct bandgaps in the range of 1.0 eV (CIS) to 1.65 eV (CGS) and are also efficient absorbers across the entire visible spectrum. The absorption coefficient for CIGS is about 10 5 /cm. Additionally, thin film solar cells can be fabricated at the module level, thus further decreasing the manufacturing costs. Furthermore, thin film solar cells may be fabricated on inexpensive substrates such as glass, plastics, and thin sheets of metal. Among the thin film solar cells, CIGS has demonstrated the best lab cell efficiency (above 20%) and the best large area module efficiency (>12%).
[0003] The increasing demand for environmentally friendly, sustainable and renewable energy sources is driving the development of large area, thin film photovoltaic (TFPV) devices. With a long-term goal of providing a significant percentage of global energy demand, there is a concomitant need for Earth-abundant, high conversion efficiency materials for use in photovoltaic devices. A number of Earth abundant direct-bandgap semiconductor materials now seem to show evidence of the potential for both high efficiency and low cost in Very Large Scale (VLS) production (e.g. greater than 100 gigawatt (GW)), yet relatively little attention has been devoted to their development and characterization.
[0004] Among the TFPV technologies, CIGS and CdTe are the two that have reached volume production with greater than 10% stabilized module efficiencies. Solar cell production volume must increase tremendously in the coming decades to meet sharply growing energy needs. However, the supply of In, Ga and Te may impact annual production of CIGS and CdTe solar panels. Moreover, price increases and supply constraints in In and Ga could result from the aggregate demand for these materials used in flat panel displays (FPD) and light-emitting diodes (LED) along with CIGS TFPV. Also, there are concerns about the toxicity of Cd throughout the lifecycle of the CdTe TFPV solar modules. Efforts to develop devices that leverage manufacturing and R&D infrastructure related to TFPV using more widely available and more environmentally friendly raw materials should be considered a top priority for research.
[0005] The immaturity of TFPV devices exploiting Earth abundant materials represents a daunting challenge in terms of the time-to-commercialization. That same immaturity also suggests an enticing opportunity for breakthrough discoveries. A quaternary system such as CIGS or CZTS requires management of multiple kinetic pathways, thermodynamic phase equilibrium considerations, defect chemistries, and interfacial control. The vast phase-space to be managed includes process parameters, source material choices, compositions, and overall integration schemes. Traditional R&D methods are ill-equipped to address such complexity, and the traditionally slow pace of R&D could limit any new material from reaching industrial relevance when having to compete with the incrementally improving performance of already established TFPV fabrication lines.
[0006] However, due to the complexity of the material, cell structure and manufacturing process, both the fundamental scientific understanding and large scale manufacturability are yet to be improved for CIGS and CZTS solar cells. As the photovoltaic industry pushes to achieve grid parity, much faster and broader investigation is needed to explore the material, device, and process windows for higher efficiency and a lower cost of manufacturing process. Efficient methods for forming different types of CIGS and CZTS solar cells that can be evaluated are necessary.
[0007] The efficiency of TFPV solar cells depends on many properties of the absorber layer and the buffer layer such as crystallinity, grain size, composition uniformity, density, defect concentration, doping level, surface roughness, etc. Many of these properties may be improved by annealing the layers at high temperatures (i.e. about 600 C-1000 C). However, this is above the melting point of soda lime glass (600 C), a common substrate for thin film solar cells as well as other potential substrates such as plastic sheets.
[0008] Therefore, there is a need to develop methods of heating the layers used to fabricate thin film solar cells without degrading the substrate or other layers. There is a need for methods of heating that promote grain growth and decrease the surface roughness. There is a need for methods of heating that decrease the concentrations of defects and vacancies within the layers leading to improved efficiency. There is a need for methods of heating that promote the interdiffusion of layers or dopants to achieve a desired layer composition and structure. There is a need for methods of heating that can be used to remove surface contamination before subsequent processing steps. There is a need for methods of heating that can be used to alter the optical transmission properties of various layers.
SUMMARY OF THE INVENTION
[0009] In some embodiments of the present invention, lasers are used to thermally treat one or more layers used in the fabrication of TFPV solar cells. In some embodiments, the laser is a pulsed laser. In some embodiments, the laser is a continuous wave (CW) laser.
[0010] In some embodiments of the present invention, lasers are used to anneal the absorber layer of a single-graded CIGS solar cell to enhance interdiffusion of the In and Ga. The laser anneal step may optionally be followed by an H 2 Se or Se anneal to fill the Se vacancies. This process would improve the open circuit voltage (Voc) of the solar cell by creating a Ga rich surface layer.
[0011] In some embodiments of the present invention, a single-graded CIGS absorber layer is followed by the deposition of a thin layer of In—Ga—Se. This film stack is then annealed using a laser to form a double graded CIGS material. Optionally, this step may then be followed by an H 2 Se or Se anneal to fill the Se vacancies. This process would improve the open circuit voltage (Voc) of the solar cell by creating a Ga rich surface layer.
[0012] In some embodiments of the present invention, CIGS, CZTS, or CdTe films are printed on a substrate followed by an anneal using a laser. The laser anneal may result in a film with higher density and larger grains.
[0013] In some embodiments of the present invention, a Na-free CIGS layer is followed by the deposition of Na 2 Se. This film stack is then annealed using a laser to incorporate the Na into the underlying CIGS layer in a uniform manner and improve the efficiency of the solar cell.
[0014] In some embodiments of the present invention, a laser is used to ablate oxides and excess Na from the surface of a CIGS absorber layer in an inert atmosphere. In some embodiments of the present invention, a laser is used to ablate oxides from the surface of a CZTS absorber layer in an inert atmosphere. The substrate can then be transported into a dry deposition chamber for the deposition of CdS without exposing the substrate to an air ambient. The use of the laser ensures that only the top few nanometers of material are removed.
[0015] In some embodiments of the present invention, an anneal step using a laser can be used to activate n-type dopants on a CIGS or CZTS surface to create an inverted n-type layer on the surface. The n-type layer can be important for reducing interface recombination by the formation of a buried homojunction.
[0016] In some embodiments of the present invention, an anneal step using a laser can be used after the deposition of the CIGS, CZTS, or CdTe absorber layer and the CdS buffer layer to improve the optical transmittance of the CdS layer and remove recombination centers at the absorber layer/CdS interface. This step may increase the quantum efficiency and Voc, resulting in increased solar cell efficiency.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. The drawings are not to scale and the relative dimensions of various elements in the drawings are depicted schematically and not necessarily to scale.
[0018] The techniques of the present invention can readily be understood by considering the following detailed description in conjunction with the accompanying drawings, in which:
[0019] FIG. 1 illustrates a simplified cross-sectional view of a TFPV solar cell stack fabricated in accordance with some embodiments of the present invention.
[0020] FIG. 2 illustrates a simplified cross-sectional view of a TFPV solar cell stack fabricated in accordance with some embodiments of the present invention.
[0021] FIG. 3 illustrates a simplified cross-sectional view of a TFPV solar cell stack fabricated in accordance with some embodiments of the present invention.
[0022] FIG. 4 illustrates a simplified cross-sectional view of a TFPV solar cell stack fabricated in accordance with some embodiments of the present invention.
[0023] FIG. 5 illustrates a simplified schematic of a laser annealing system in accordance with some embodiments of the present invention.
[0024] FIG. 6 illustrates a simplified schematic of the use of a laser annealing system in accordance with some embodiments of the present invention.
[0025] FIG. 7 illustrates a flow chart illustrating a method for fabricating a TFPV solar cell stack, in accordance with some embodiments of the present invention.
DETAILED DESCRIPTION
[0026] A detailed description of one or more embodiments is provided below along with accompanying figures. The detailed description is provided in connection with such embodiments, but is not limited to any particular example. The scope is limited only by the claims and numerous alternatives, modifications, and equivalents are encompassed. Numerous specific details are set forth in the following description in order to provide a thorough understanding. These details are provided for the purpose of example and the described techniques may be practiced according to the claims without some or all of these specific details. For the purpose of clarity, technical material that is known in the technical fields related to the embodiments has not been described in detail to avoid unnecessarily obscuring the description.
[0027] As used herein, “CIGS” will be understood to represent the entire range of related alloys denoted by Cu(In x Ga 1-x )(S y Se 2-y ) where 0≦x≦1 and 0≦y≦2. As used herein, “CZTS” will be understood to represent the entire range of related alloys denoted by Cu 2 ZnSn(S y Se 1-y ) 4 where 0≦y≦1.
[0028] In FIGS. 1-4 below, a TFPV material stack is illustrated using a simple planar structure. Those skilled in the art will appreciate that the description and teachings to follow can be readily applied to any simple or complex TFPV solar cell morphology. The drawings are for illustrative purposes only and do not limit the application of the present invention.
[0029] FIG. 1 illustrates a simple CIGS TFPV material stack, 100 , consistent with some embodiments of the present invention. The convention will be used wherein light is assumed to be incident upon the top of the material stack as illustrated. A back contact layer, 104 , (typically Mo) is formed on a substrate, 102 , (typically soda lime glass (SLG)). The back contact layer is typically between about 0.2 um and 1.0 um in thickness. The back contact layer is typically formed using a physical vapor deposition (PVD) process but may also be formed using an evaporation process. A CIGS absorber layer, 106 , is formed on top of the back contact layer. The absorber layer is typically between about 0.5 um and 3.0 um in thickness. The absorber layer may be formed using a variety of techniques such as PVD, co-evaporation, printing or spraying of inks, CVD, etc. Advantageously, the absorber layer is deficient in Cu. The Cu deficiency may be controlled by managing the deposition conditions. Advantageously, a small amount of Na is contained in the absorber layer. The Na may be added by out-diffusion from the SLG substrate or may be purposely added in the form of Na 2 Se after the deposition of the absorber layer. Optionally, the absorber layer undergoes a selenization process after formation to fill the Se vacancies within the matrix. The selenization process involves the exposure of the absorber layer to H 2 Se, Se vapor, or diethylselenide (DESe) at temperatures between about 400 C and 600 C. During the selenization process, a layer of MoSe 2 forms at the back contact/absorber layer interface and forms a good ohmic contact between the two layers. A buffer layer, 108 , (typically CdS) is then formed on top of the absorber layer. The buffer layer is typically between about 30 nm and 80 nm in thickness. The buffer layer is typically formed using a CBD technique or by PVD. Optionally, an intrinsic ZnO (iZnO) layer, 110 , is then formed on top of the buffer layer. The iZnO layer is a high resistivity material and forms part of the transparent conductive oxide (TCO) stack that serves as part of the front contact structure. The TCO stack is formed from transparent conductive metal oxide materials and collects charge across the face of the TFPV solar cell and conducts the charge to the opaque metal grids used to connect the solar cell to external loads. The iZnO layer makes the TFPV solar cell less sensitive to lateral non-uniformities caused by differences in composition or defect concentration in the absorber and/or buffer layers. The iZnO layer is typically between about 30 nm and 80 nm in thickness. The iZnO layer is typically formed using a reactive PVD technique or CVD technique. A low resistivity top TCO layer, 112 , (examples include Al:ZnO (AZO), InSnO (ITO), InZnO, B:ZnO, Ga:ZnO, F:ZnO, F:SnO 2 , etc.) is formed on top of the iZnO layer. The top TCO layer is typically between about 0.3 um and 2.0 um in thickness. The top TCO layer is typically formed using a reactive PVD technique or CVD technique. An anti-reflection coating (ARC) layer, 114 , (typically MgF 2 ) is formed on top of the top TCO layer. The ARC layer increases the efficiency of the TFPV solar cell by reducing the reflection of the incident sunlight. Contained within the ARC layer is an opaque metal grid, 116 , (typically Al or Ni:Al). The metal grid is typically between about 0.5 um and 2.0 um in thickness.
[0030] FIG. 2 illustrates a simple CdTe TFPV material stack, 200 , consistent with some embodiments of the present invention. The CdTe TFPV solar cell illustrated in FIG. 2 is shown in a superstrate configuration wherein the glass substrate faces the incident sunlight. The convention will be used wherein light is assumed to be incident upon the top of the material stack as illustrated. The formation of the CdTe TFPV solar cell will be described starting with the glass substrate. A low resistivity bottom TCO layer, 204 , (typically ITO) is formed on top of the substrate, 202 , (typically SLG). The bottom TCO layer is typically between about 0.5 um and 2.0 um in thickness. The bottom TCO layer is typically formed using a reactive PVD technique or CVD technique. An intrinsic SnO 2 layer, 206 , is then formed on top of the ITO layer. The SnO 2 layer is a high resistivity material and forms part of the transparent conductive oxide (TCO) stack that serves as part of the front contact structure. The SnO 2 layer makes the TFPV solar cell less sensitive to lateral non-uniformities caused by differences in composition or defect concentration in the absorber and/or buffer layers. The SnO 2 layer is typically between about 0.3 um and 2.0 um in thickness. The SnO 2 layer is typically formed using a reactive PVD technique or CVD technique. A buffer layer, 208 , (typically CdS) is then formed on top of the SnO 2 layer. The buffer layer is typically between about 30 nm and 80nm in thickness. The buffer layer is typically formed using a CBD technique or PVD technique. A CdTe absorber layer, 210 , is formed on top of the buffer layer. The absorber layer is typically between about 0.5 um and 5.0 um in thickness. The absorber layer may be formed using a variety of techniques such as PVD, co-evaporation, printing or spraying of inks, CVD, etc. A back contact layer, 212 , (typically Cu:graphite, HgTe, ZnTe:Cu, Te, Cu 2 Te, As 2 Te 3 /Cu, Sb 2 Te 3 ) is formed on top of the absorber layer. The back contact layer is typically between about 0.3 um and 2.0 um in thickness. The back contact layer is typically formed using a PVD process, evaporation process, or CVD technique.
[0031] FIG. 3 illustrates a simple CZTS TFPV material stack, 300 , consistent with some embodiments of the present invention. The convention will be used wherein light is assumed to be incident upon the top of the material stack as illustrated. A back contact layer, 304 , (typically Mo) is formed on a substrate, 302 , (typically SLG). The back contact layer is typically between about 0.2 um and 1.0 um in thickness. The back contact layer is typically formed using a PVD process but may also be formed using an evaporation process. A CZTS absorber layer, 306 , is formed on top of the back contact layer. The absorber layer is typically between about 0.5 m and 3.0 um in thickness. The absorber layer may be formed using a variety of techniques such as PVD, co-evaporation, printing or spraying of inks, CVD, sol-gel processing, etc. Advantageously, the absorber layer is deficient in Cu. A buffer layer, 308 , (typically CdS) is then formed on top of the absorber layer. The buffer layer is typically between about 30 nm and 80 nm in thickness. The buffer layer is typically formed using a CBD technique or PVD technique. Optionally, an intrinsic ZnO (iZnO) layer, 310 , is then formed on top of the buffer layer. The iZnO layer is a high resistivity material and forms part of the transparent conductive oxide (TCO) stack that serves as part of the front contact structure. The TCO stack is formed from transparent conductive metal oxide materials and collects charge across the face of the TFPV solar cell and conducts the charge to the opaque metal grids used to connect the solar cell to external loads. The iZnO layer makes the TFPV solar cell less sensitive to lateral non-uniformities caused by differences in composition or defect concentration in the absorber and/or buffer layers. The iZnO layer is typically between about 30 nm and 80 nm in thickness. The iZnO layer is typically formed using a reactive PVD technique or CVD technique. A low resistivity top TCO layer, 312 , (examples include Al:ZnO (AZO), InSnO (ITO), InZnO, B:ZnO, Ga:ZnO, F:ZnO, F:SnO 2 , etc.) is formed on top of the iZnO layer. The top TCO layer is typically between about 0.3 um and 2.0 um in thickness. The top TCO layer is typically formed using a reactive PVD technique or CVD technique. An anti-reflection coating (ARC) layer, 314 , (typically MgF 2 ) is formed on top of the top TCO layer. The ARC layer increases the efficiency of the TFPV solar cell by reducing the reflection of the incident sunlight. Contained within the ARC layer is an opaque metal grid, 316 , (typically Al or Ni:Al). The metal grid is typically between about 0.5 um and 2.0 um in thickness.
[0032] FIG. 4 illustrates a simple CIGS TFPV material stack, 400 , consistent with some embodiments of the present invention. The CIGS TFPV solar cell illustrated in FIG. 4 is shown in a superstrate configuration wherein the glass substrate faces the incident sunlight. The convention will be used wherein light is assumed to be incident upon the top of the material stack as illustrated. The formation of the CIGS TFPV solar cell will be described starting with the glass substrate. A similar structure and similar method would also be applicable to the formation of a CZTS TFPV solar cell fabricated with a superstrate configuration. A low resistivity bottom TCO layer, 404 , (typically ITO or AZO) is formed on top of the substrate, 402 , (typically SLG). The bottom TCO layer is typically between about 0.3 um and 2.0 um in thickness. The bottom TCO layer is typically formed using a reactive PVD technique or CVD technique. An intrinsic iZnO layer, 406 , is then formed on top of the ITO layer. The iZnO layer is a high resistivity material and forms part of the transparent conductive oxide (TCO) stack that serves as part of the front contact structure. The iZnO layer makes the TFPV solar cell less sensitive to lateral non-uniformities caused by differences in composition or defect concentration in the absorber and/or buffer layers. The iZnO layer is typically between about 30 nm and 80 nm in thickness. The iZnO layer is typically formed using a reactive PVD technique or CVD technique. A buffer layer, 408 , (typically CdS) is then formed on top of the iZnO layer. The buffer layer is typically between about 30 nm and 80 nm in thickness. The buffer layer is typically formed using a CBD technique or CVD technique. A CIGS absorber layer, 410 , is formed on top of the buffer layer. The absorber layer is typically between about 0.5 um and 3.0 um in thickness. The absorber layer may be formed using a variety of techniques such as PVD, co-evaporation, printing or spraying of inks, CVD, etc. A back contact layer, 212 , (typically Mo) is formed on top of the absorber layer. The back contact layer is typically between about 0.2 um and 1.0 um in thickness. The back contact layer is typically formed using a PVD process but may also be formed using an evaporation process.
[0033] As mentioned previously, many of the electrical and optical properties of the absorber layers and the buffer layers of TFPV solar cells can be improved with heat treatments. However, for isothermal techniques such as furnace treatments or quasi-isothermal techniques such as rapid thermal annealing (RTA), the upper temperature range is limited due to the substrate and other layers present in the device since these techniques heat the entire structure. As an example, soda lime glass has a glass transition temperature between about 550 C and about 600 C and heat treatments of the absorber layers and the buffer layers must be kept well below this threshold.
[0034] The high absorption coefficients for CIGS, CdTe, and CZTS make them well suited for laser processing using laser with wavelengths shorter than about 1100 nm. Examples of suitable lasers include semiconductor diode lasers (e.g. AlGaAs/AlGaAs/GaAs: 700-900 nm continuous wave; GaInP/AlGaInP/GaAs: 660-690 nm continuous wave;), Nd:YAG (diode-pumped solid state, rod) doubled to 532 nm (pulsed); Nd:YAG (flashlamp) doubled to 532 nm (pulsed); and TiSaph (tunable) (690-1040 nm) (pulsed). These lasers have peak powers up to about 300 kW. Due to the strong absorption, the energy of the laser will be delivered only to the near surface region of the layer (i.e. <0.1 um). Therefore, it should be possible to raise the temperature of the surface to temperatures well above the glass transition temperature of the substrate without damaging the substrate or underlying layers. Furthermore, the laser beam may be focused into a useful shape that can be scanned across the surface of the TFPV module. Examples of such useful shapes comprise circles, rectangles, squares, ovals, etc. Such a system should be able to process the sample at a rate of up to about 10,000 mm 2 /sec. Due to the long heating and cooling time, furnace anneals can achieve rates of only about 1,000 mm 2 /sec.
[0035] FIG. 5 illustrates a simplified schematic of a laser annealing system in accordance with some embodiments of the present invention. In FIG. 5 , a TFPV solar cell has been partially fabricated by forming a back contact layer, 504 , on a substrate, 502 . In the case of CIGS or CZTS solar cells, the optional deposition of a Na 2 Se layer may have been performed. Illustrated in FIG. 5 is a laser system, 508 , that produces a laser beam, 510 , that is directed and focused on the surface of the solar cell stack by mirrors, 512 , and lenses, 514 . The laser system may be pulsed or may be a CW laser system. The laser system is selected such that the energy of the photons is greater than the bandgap of the layer being annealed. In the case of most CIGS, CZTS, and CdTe films, this requires a laser with a wavelength shorter than about 1100 nm. Therefore, any of the laser systems that emit in the visible range are suitable. The laser annealing environment may be vacuum, inert gas, a Se-containing atmosphere, or an S-containing atmosphere. When annealing in an S or Se-containing atmosphere, the annealing step may increase the S or Se concentration in the material and fill S or Se vacancies which improve the efficiency of the solar cell.
[0036] FIG. 6 illustrates a simplified schematic of the use of a laser annealing system in accordance with some embodiments of the present invention. In FIG. 6 , a laser beam has been focused into a rectangular shape as indicated by 602 . However, the beam may be of any useful shape as mentioned previously. The laser beam may be caused to scan across the surface of the solar cell stack, 606 , as indicated by the arrows, 604 . The scanning pattern indicated in FIG. 6 is for illustrative purposes only and is not meant to be limiting. Those skilled in the art will appreciate that the details of the scanning pattern may be adapted to the specific geometry and constraints of the substrate and system being used. Alternatively, the substrate with the back contact and the absorber layer, 606 , can be moved and the laser beam would remain stationary.
[0037] FIG. 7 illustrates a flow chart illustrating a method for fabricating a TFPV solar cell stack, in accordance with some embodiments of the present invention. The method will generally describe the process for forming a CIGS or CZTS TFPV solar cell. The method begins with a glass substrate, 700 . A back contact layer is formed on the substrate in step 702 as described previously. The back contact is patterned in step 704 in a process commonly known as P1 scribe. This step divides the back contact layer into a plurality of smaller cells on the substrate. In step 706 , the absorber is formed on the scribed back contact. The absorber may be CIGS or CZTS as discussed previously. In step 708 , the absorber layer is annealed using a laser as described previously. In step 710 , the buffer layer is formed on the annealed absorber layer. Typically, the buffer layer is CdS as discussed previously. In step 712 , the buffer layer is annealed using a laser as described previously. CdS has an absorption edge at about 600 nm, so laser systems that emit wavelengths less than about 600 nm are advantageous for this step. The buffer layer and absorber layers are then patterned in step 714 in a process commonly known as P2 scribe. This step divides the buffer layer and absorber layers into a plurality of smaller cells on the substrate. The scribe pattern for P2 is generally different from the scribe pattern of P1. In step 716 , the front contact or TCO layer is formed on the scribed buffer layer. The TCO layer is then patterned in step 718 in a process commonly known as P3 scribe. This step divides the TCO layer into a plurality of smaller cells on the substrate. The scribe pattern for P3 is generally different from the scribe pattern of P1 and P2. This generally completes the formation of the TFPV solar cell stack. In step 720 , the substrate and the TFPV solar cell stack are encapsulated to protect the device from environmental elements such as water, dirt, dust, etc. In step 722 , the encapsulated substrate is integrated into a frame and other components to for a solar cell module. Finally, in step 724 , the solar cell module is tested for performance and reliability.
[0038] The use of lasers for the heat treatment of the absorber layer and/or the buffer layer for TFPV solar cells may have a number of benefits. Annealing at high temperature is known to improve the crystallinity of thin films by recrystallizing incomplete reaction phases, removing crystal defects, increasing grain size, increasing the density, and re-orienting the grains. The use of lasers allows the absorber layer and/or the buffer layer to be heated to temperatures close to their melting point without damaging other layers of the structure due to the shallow absorption of the laser beam. Similarly, the surface roughness of the layers will be improved after laser annealing due to enhanced migration of the surface atoms. Laser annealing may be used to improve the compositional homogeneity of the absorber layer and/or the buffer layer due to increased atomic diffusion at the elevated temperatures. The CdTe, CIGS, and CZTS absorber layers are complex, multi-component materials and their optical properties are sensitive to their composition and uniformity. The use of lasers for annealing the absorber layer and/or the buffer layer may allow non-equilibrium phases to be quenched due to the short timescales that are typical of laser materials processing. The expectation is that the laser beam is used to melt a thin film comprised of different phases. In the liquid state, compositions that are not stable under equilibrium conditions can exist. The heat flow out of the material at the end of the laser pulse or after the laser beam has passed (in the case of a CW laser), is fast and may quench the non-equilibrium composition into the solid phase. These compositions may have advantageous properties.
[0039] In one example of the use of laser annealing of the absorber layer, a single-graded CIGS absorber layer may be formed on the back contact. In this single-graded scenario, the Ga concentration is non-uniform throughout the layer with the Ga concentration being higher near the absorber/back contact interface. The single-graded CIGS absorber layer may then be laser annealed to enhance the interdiffusion of the In and Ga and optionally followed by a low temperature selenization step. In this example, the laser annealing could improve the open circuit voltage (Voc) and the solar cell efficiency by moving some of the Ga toward the absorber/buffer layer interface. The Voc is improved because the substitution of Ga for In increases the band gap of the material and the Voc scales with the band gap. A similar example may be described for a CZTS absorber layer where Zn or Sn are the materials of interest.
[0040] In another example of the use of laser annealing of the absorber layer, a single-graded CIGS absorber layer may be formed on the back contact. This layer is followed by the deposition of a thin layer of In—Ga—Se. This film stack may then be laser annealed to form a double-graded CIGS absorber layer wherein the Ga concentration is higher at both the absorber/back contact interface and at the absorber/buffer layer interface. The double-graded CIGS absorber layer may then be subjected to a low temperature selenization step. More specifically, a precursor layer containing elements such as Ga, Al, Ag, or S can be deposited on the single-graded absorber layer discussed previously. Laser annealing may be used to incorporate these elements in the surface region of the absorber layer to increase the band gap in the depletion region of the device. The depletion region naturally forms at the absorber/buffer layer interface. The laser annealed absorber layer may then be subjected to a low temperature selenization step. The precursor layer may be deposited from solutions. As an example, Ga can be deposited from solutions such as gallium trichloride (GaCl 3 ), gallium acetylacetonate (Ga(Ch 3 COCHCOCH 3 ) 3 ), or gallium acetate (C 6 H 9 GaO 6 ). As discussed previously, the laser annealing may be performed in a Se-containing atmosphere to further improve the efficiency. A similar example may be described for a CZTS absorber layer.
[0041] In another example of the use of laser annealing of the absorber layer, a printed CIGS absorber layer may be annealed to increase the density and increase the grain size of the layer. Printed CIGS absorber layers typically utilize formulations, inks, slurries, etc. of small or nanoparticles of the layer composition. Generally, these are colloidal suspensions of the particles. During the synthesis of the particles, the surfaces often contain organic groups and/or oxides phases of the constituents. Typically, the layer is subjected to separate steps to remove the organic and oxide contaminants. Examples of steps that are used include etching in KCN to remove the oxides and annealing in N 2 or H 2 to remove the organic contaminants. These steps could be followed by laser annealing to increase the density and increase the grain size of the layer by consolidating the nanoparticles. Additionally, the techniques described in the previous examples could be incorporated to form graded layers of CIGS. In some embodiment, the laser annealing step may be used to remove the organic contaminants. A similar example may be described for a CZTS absorber layer.
[0042] In another example of the use of laser annealing of the absorber layer, a Na-free absorber layer may be formed on the back contact followed by the deposition of Na 2 Se on top of the absorber layer. Laser annealing may be used to incorporate the Na into the absorber layer. The incorporation of a small amount of Na has been found to provide a number of benefits such as improved Voc and improved fill factor, improved grain size and orientation, improved p-type doping, and grain boundary passivation. Additionally, the presence of Na impacts other properties such as metastability, MoSe 2 formation, and allows the absorber performance to be maintained across a wider compositional range. A similar example may be described for a CZTS absorber layer.
[0043] In another example of the use of laser annealing of the absorber layer, surface oxides and excess Na can be ablated from the surface prior to the deposition of the buffer layer. Advantageously, this process may be performed in a vacuum, N 2 , or inert atmosphere and the substrate may be transported into the buffer layer deposition without being exposed to air. This may improve the absorber/buffer layer interface by preventing the growth of unwanted oxides. The laser may be used to remove the top few nanometers of the layer by managing the laser power and the scan speed. A similar example may be described for a CZTS absorber layer.
[0044] In another example of the use of laser annealing of the absorber layer, n-type dopants can be activated during the laser anneal process. Halogen atoms such as Cl, Br, and I are n-type dopants in CIGS materials. These atoms can be ion implanted into the absorber layer and then activated using a laser anneal process to form an inverted n-type layer. The inverted n-type layer will form a buried homojunction resulting in a reduction in the interface recombination. A similar example may be described for a CZTS absorber layer.
[0045] In an example of the use of laser annealing of the buffer layer, the CdS buffer layer may be deposited on the absorber layer. A laser annealing process may then be used to improve the optical transmittance of the buffer layer. The optical transmittance of the buffer layer is higher after the laser annealing. Additionally, laser annealing may lead to a reduction in recombination centers. This may increase the quantum efficiency and increase the Voc of the solar cell.
[0046] Although the foregoing examples have been described in some detail for purposes of clarity of understanding, the invention is not limited to the details provided. There are many alternative ways of implementing the invention. The disclosed examples are illustrative and not restrictive. | A method for forming copper indium gallium (sulfide) selenide (CIGS) solar cells, cadmium telluride (CdTe) solar cells, and copper zinc tin (sulfide) selenide (CZTS) solar cells using laser annealing techniques to anneal the absorber and/or the buffer layers. Laser annealing may result in better crystallinity, lower surface roughness, larger grain size, better compositional homogeneity, a decrease in recombination centers, and increased densification. Additionally, laser annealing may result in the formation of non-equilibrium phases with beneficial results. | 8 |
This invention relates generally to motors and more particularly to a high speed water turbine driven motor for drilling or grinding operations.
BACKGROUND OF THE INVENTION
Fluid driven drills such as by either air or water are known in the art. A preferred application for such types of drills is in dental work since there is no electricity involved at the portion of the instrument placed in a person's mouth. Moreover, very high speeds can be obtained utilizing air or water turbines to drive the drill.
Other applications for high speed drills is in the drilling of printed circuit boards. Thus rather than a hand held drill motor, these applications would normally involve a permanently mounted motor in a circuit drilling machine mechanism.
While the foregoing described motors have been satisfactory, their life is severely limited by the life of bearings utilized in rotatably mounting the rotor shaft carrying the drill or grinding tool or other instrument to be rotated. The enormously high speeds attainable by these drills simply cannot be handled by presently available mechanical type bearings. The only solution, accordingly, is to operate such drills at lower speeds or to redesign the bearings with expensive components far out of proportion of the overall cost of the tool and its particular job. Neither solution is really satisfactory.
BRIEF DESCRIPTION OF THE PRESENT INVENTION
With the foregoing considerations in mind, the present invention contemplates a high speed water driven motor for drills, grinders and the like in which high rotational speed can be maintained over extended periods of time without seriously affecting the bearings.
More particularlay, in accord with this invention, rather than mechanical type bearings, there are provided conically shaped water bearings so designed as to "float" the rotor shaft on a film of water derived from the high pressure water source utilized in driving appropriate turbine wheels on the rotor shaft. The continuous flow of water through the water bearings as well as through the turbine provides for a substantially frictionless bearing support over sustained high speed running periods, generated heat simply being carried away by the continuous flow of water through the bearing.
The foregoing described design lends itself well for drill motors in printed circuit drilling board systems as well as in hand held drills for use by dentists either for drilling purposes or grinding purposes.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of this invention will be had by now referring to the accompanying drawings, in which:
FIG. 1 is a cross sectional view with certain portions shown in full lines of the water powered high speed motor of this invention;
FIG. 2 is a cross section of an inlet nozzle for a turbine portion of the motor looking in the direction of the arrows 2--2 of FIG. 1;
FIG. 3 is a plan view of a disk type spring looking in the direction of the arrows 3--3 of FIG. 1 and,
FIG. 4 is a cross section with certain components shown in full lines of a modified embodiment of the motor of this invention designed for hand held operation.
DETAILED DESCRIPTION OF THE INVENTION
Referring first to FIG. 1, the water powered high speed motor comprises a casing 10 defining an inner chamber designated generally by the arrow 11.
Within the chamber 11 is a rotor shaft 12 having oppositely directed conical end surfaces 13 and 14. These end surfaces cooperate with first and second axially spaced oppositely directed conical bearing blocks 15 and 16 respectively. The first bearing block 15 is secured in a stationary position relative to the casing 10 while the second conical bearing block 16 is mounted to the casing for axial movement towards and away from the first bearing block. This mounting is accomplished by means of a resilient spring 17 which functions to bias the second block 16 in an axial direction to increase the engaging pressure between the bearing blocks and the conical end surfaces; that is, in an upward direction as viewed in FIG. 1.
The first and second bearing blocks 15 and 16 are provided with water inlet passages indicated at 18 and 19 respectively. The passage 19 is shown broken off to avoid obscuring portions of the drawings. However, this passage 19 connects to the passage 18 as indicated by the dashed line 20 in FIG. 1. The passages 18 and 19 pass into each bearing block to communicate with the surfaces of the bearing blocks and the conical end surfaces of the shaft.
Shown on the shaft 12 between the first and second bearing blocks 15 and 16 are turbine wheel means 21 in the form of first and second axially spaced wheels with turbine blades forming mirror images of each other such that water directed tangentially to the blades will cause rotation of the shaft 12. Towards this latter end, there is provided a turbine wheel water inlet nozzle 22 which guides water through the turbine wheels 21 and thence from the turbine wheels into the inner chamber 11 of the casing 10.
Referring to the upper portion of FIG. 1, there is shown at 23 a high water pressure inlet passage for directing water through the casing to the water bearings and turbine wheels. More particularly, water from the inlet passage 23 passes through a valve head 24 and water filter screen 25 to the bearing passage 18 and the connected bearing passage 19 for the bearings 15 and 16 respectively. The high pressure water received in these inlet passages essentially results in the conical end surfaces of the shaft being caused to float on a thin film of water covering the engaging surfaces of the bearing blocks to provide a water bearing. Because of the biasing of the second block 16 relative to the first block 15 as by the spring 17, the blocks can seperate axially slightly to accomodate the thin film of water between the bearing surfaces and the conical shaft end surfaces. It will be understood that water will continuously flow through the inlet passages to the bearings and thence from between the bearing surfaces into the inner chamber 11 of the casing 10.
Referring again to the upper portion of FIG. 1, the same high pressure water in the inlet passage 23 also is directed through a latteral valve port cooperating with the valve head 24 and partially eclipsed by this valve head. This latteral port leads into a passage 26 for directing the water through the inlet nozzle structure 22 between the turbine wheels 21. Water will rotate the turbine wheels 21 passing through these wheels into the inner chamber 11 of the casing 10.
The water from the bearings as well as coming from the turbine wheels into the chamber 11 will then be exhausted through an appropriate outlet passage 27 shown in the lower portion of the casing 10 in FIG. 1.
It can be appreciated from the foregoing that the same high pressure water in the inlet passage 23 serves to control not only the water bearing operation but also to rotate the rotor shaft, the water bearing being such as to permit very high speed rotation of the rotor shaft by the flow of water through the turbine wheels without any significant wear on the bearing surfaces. In this latter respect, it will be understood that any heat developed is continuously being carried away by the water film itself constituting the actual bearing and holding the bearing surfaces in a seperated relationship.
In the particular embodiment of FIG. 1, there is additionally provided a rotor shaft speed control means to, in effect, govern the speed of rotation of the rotor shaft. With particular reference to the central portion of FIG. 1, this speed control means includes tachometer pump means in the form of pump wheels 28 secured to the shaft 12 between the turbine wheels 21 and first bearing block 15. The wheels 28 have slanted blades in mirror image relationship such that rotation of the shaft results in a build up in water pressure between the wheels. This build up in water pressure is communicated through a water passage 29 extending up the left of the casing 10 to be applied under a rubber diaphram 30 supporting the valve head 24 by way of valve stem 31.
The area above the rubber diaphram 30 is subject to controlled air pressure by an input duct 32.
When the foregoing components, the tachometer wheels rotate with the rotor shaft and will generate a water pressure constituting a function of the speed of this shaft, this water pressure being applied under the rubber diaphram 30 to oppose a given constant air pressure applied through the inlet port 32 above the diaphram. As described heretofore, the flow of high pressure inlet water in the passage 23 to the turbine wheels 21 takes place through lateral valve ports partially eclipsed by the valve head 24, these valve ports connecting the inlet water passage 23 with the passage 26 leading to the turbine wheels. Accordingly, when the valve head 24 moves downwardly as a result of downward movement of the rubber diaphram 30 and valve stem 31, the lateral ports are opened up further to thereby permit an increased flow of water to take place from the passage 23 to the passage 26 and thus to the turbine wheels. When the valve head 24 is moved upwardly, on the other hand, the lateral ports are closed off more thereby decreasing the water flow from the inlet passage 23 to the passage 26 and to the turbine wheels.
From the foregoing, it can thus be seen that when the generated water pressure by the tachometer wheels 28 exceeds a predetermined pressure, such predetermined pressure being applied to the top of the rubber diaphram 30 through the inlet port 32, the raising up of the diaphram 30 and thus the valve head 24 will close off the lateral ports more than they are already eclipsed to thereby reduce the water flow to the turbine wheels. This action results in a slowing down of the speed of the rotor shaft and thus a decrease in the generated water pressure by the tachometer wheels 28 and thus a decrease in the water pressure beneath the diaphram 30. It will thus be seen that a self regulation takes place so that the speed of the rotor is held at a substantially constant value.
If it is desired to run the rotor 12 at maximum speed, a very high pressure may be applied to the top of the rubber diaphram 30 through the inlet port 32 to seat completely this diaphram on the periphery of the opening through which the stem 31 extends thus sealing this opening and further positioning the valve head 24 well below the lateral ports so that maximum flow can take place from the passage 23 to the passage 26 and thus maximum flow through the turbine wheels will take place.
In running the rotor at maximum speed, it is desirable not to have high pressure generated by the tachometer wheels 28 as described under normal governing conditions. Accordingly, there is provided an air inlet 33 at the top of the casing through which air can be forced through a check valve 34 into the fluid passage 29 to force all liquid out from between the tachometer wheels 28 thereby reducing any friction which would otherwise be caused by the presence of liquid between these wheels. When these conditions are met, the rotor 12 could run at maximum speed.
The water bearings comprising the tapered end surfaces 13 and 14 on the rotor shaft 12 and the first and second bearing blocks 15 and 16 maybe designed in accord with the teachings of our U.S. Pat. No. 3,929,393 issued Dec. 30, 1975 which discloses a water-rubber bearing system.
Where the motor described in FIG. 1 is to be used in a circuit board drilling system, an appropriate centrifugal type clutch 35 could be secured to the rotor shaft 12, this clutch 35 operating in accord with the teachings of our U.S. Pat. No. 4,017,203 issued Apr. 12, 1977. An appropriate drill 36 is shown secured in the centrifugal clutch 35.
If it is desired to monitor the speed of the drill 36, the motor may incorporate an appropriate means for detecting the rate of rotation of the rotor shaft 12. In FIG. 1, one such means is shown in the form of a magnetic stainless steel flat structure secured to the upper end of the rotor 12 above the conical end surface 13 as shown at 37. Embedded adjacent to this stainless steel flat 37 is a magnetic pickup 38 responsive to the change in flux resulting from rotation of the flat 37.
The variable signal from the magnetic pickup 38 can readily be converted to an output rpm reading thus providing a continuous monitoring of the rotor speed.
Referring now to FIG. 2, there is shown in the cross sectional view further details of the turbine wheel water inlet nozzle 22. As shown, there are provided tangential passages 22' defined circumferentially about the inlet of the turbine wheels.
FIG. 3 illustrates the spring 17 in further detail wherein the arcuate slots 17' will provide the desired resiliency for the second bearing 16 of FIG. 1 in an axial direction but inhibit any movement in a radial or lateral direction.
Referring now to FIG. 4, there is shown a modified embodiment of the water motor of this invention in the form of a hand held type motor and wherein the speed control means is not included. However, the remaining basic components are essentially the same as those described in conjunction with FIG. 1.
Thus, with specific reference to FIG. 4 the motor includes a casing 39 defining an inner chamber 40. A rotor shaft 41 in turn is provided with oppositely directed conical end surfaces 42 and 43 cooperating with first and second bearing blocks 44 and 45. The second bearing block 45 is again supported by a spring structure 46 for limited axial movement and to bias the same towards the bearing block 44. The rotor 41 is thus held captive between the bearing blocks.
Suitable inlet water passages 47 and 48 are provided for the water blocks so that under high pressure water, there results a water bearing or thin film of water between the tapered surfaces of the shaft and blocks respectively all as described with respect with FIG. 1.
Also as in the case of FIG. 1, the rotor shaft 41 includes turbine wheel means 49 having a nozzle input structure 50 for receiving water under high pressure in an inlet water passage 51. This high pressure water passes not only through the turbine blades 49 but also into the passages 47 and 48 for the water bearings as in the case of FIG. 1. From the water bearings and from the top and under side of the respective turbine wheels the water passes to the inner chamber 40 and thence through an outlet passage which is coaxially arranged about the inlet passage 51. This coaxial outlet passage is indicated at 52.
In the embodiment of FIG. 4, rather than a centrifugal clutch, there is shown a simple collet 53 for supporting an instrument such as a grinding wheel 54 to be rotated at high speed.
By avoiding the use of the speed control in the embodiment of FIG. 4, the overall size of the motor can be greatly reduced. Actually, the straight-line torque characteristic of the turbine coupled with the fast-rising friction characteristic of the water bearings combine to maintain speed as load is applied even without the speed controller described in conjunction with FIG. 1.
From all the foregoing, it will thus be evident that the present invention has provided a greatly improved water powered high speed motor. The use of water bearings in combination with a turbine wherein the same high water pressure source operates the bearings as well as rotates the turbine wheels enables very high rotor speeds to be acheived without requiring frequent replacement of bearings nor oversized complicated and expensive bearing structures. | The water powered motor includes a casing housing a rotor shaft. First and second water bearings of conical shape support opposite end portions of the shaft for high speed rotation. The central portion of the shaft has turbine wheels subject to high velocity water flow through the casing. The same high water pressure for driving the turbine also provides water to the water bearings to "float" the rotor shaft so that very high speeds can be attained with minimum friction. The preferred application for the motor is that of a high speed drill for drilling printed circuit boards. However, it may be miniaturized for use as a dentist's drill. | 1 |
BACKGROUND OF THE INVENTION
The invention relates to a damping device for movable furniture parts comprising a fluid damper which is in the form of a rotational damper and which is radially displaceably supported and which includes two members which are rotatably movable relative to each other, namely a housing and a drum disposed in the housing, wherein disposed in the housing is a damping fluid, for example a silicone oil, and during damping one of the two members is rotated by an actuating member and the other member is held fast.
Damping devices of that kind are used in modern articles of furniture so that, when closing a door or a drawer, the door or a front panel of the drawer is prevented from hitting against the body of the article of furniture with excessive force.
Advantageously, damping devices of that kind are provided with a freewheel so that they move unimpededly into their readiness position when the door or the drawer is opened.
BRIEF SUMMARY OF THE INVENTION
The object of the invention is to provide a damping device of the kind set forth in the opening part of this specification with an improved and structurally simple freewheel arrangement.
The object in accordance with the invention is attained in that the rotational damper is pressed against a retaining element by the actuating member during the damping action.
It is advantageously provided that the drum is in the form of a rotor which, in the damping action, is rotated by the actuating member and that the housing is held by the retaining element.
The retained member can advantageously be held by frictional engagement or by a directional tooth locking means.
An advantageous embodiment of the invention provides that the rotational damper is mounted pivotably by means of a rocker member fixed to a carrier.
In a further embodiment of the invention it is provided that the rotational damper is mounted with a mounting axis in at least one and preferably two mutually opposite inclined elongate holes in a carrier.
In order to ensure, also in the case of a drawer or door which is closed very slowly, that the damping action of the damping device does not nullify the action of the device pulling the drawer or door shut so that the door or drawer would not be completely closed, a further preferred embodiment of the invention has a spring which lifts the rotational damper or the member of the rotational damper which is retained during the damping action off the retaining element.
Various embodiments of the invention are described hereinafter with reference to the Figures of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a diagrammatic side view of a pull out guide assembly for a drawer, equipped with a damping device according to the invention during a closing movement,
FIG. 2 shows the same side view as in FIG. 1 during an opening movement,
FIG. 3 shows a side view of a pull out guide assembly, equipped with a damping device according to the invention in a further embodiment, during closure of the drawer,
FIG. 4 shows the same side view as that of FIG. 3 during opening of the drawer,
FIG. 5 is a view in section taken along line A—A in FIG. 3,
FIG. 6 shows a side view of a pull out guide assembly, equipped with a further embodiment of the damping device according to the invention, during closure of the drawer,
FIG. 7 shows the same view as that in FIG. 6 during opening of the drawer,
FIG. 8 shows a side view of a pull out guide assembly for a drawer, equipped with a further embodiment of the damping device according to the invention, during closure of the drawer,
FIG. 9 shows the same side view as in FIG. 8 during opening of the drawer, and
FIG. 10 is a view in section taken along line A—A in FIG. 8 .
DETAILED DESCRIPTION OF THE INVENTION
Drawers are guided slidably in a body 1 of an article of furniture with side walls 1 ; by means of pull out guide assemblies. The drawers have, at each of two sides respective drawer side walls 3 which cover rails 4 , 5 , 6 of the pull out guide assembly as far as a fixing limb 4 ′ of the support rails 4 . The drawer side walls 3 likewise covers a damping device 14 according to the invention.
Fixed on pull out rail 6 is a carrier 7 of the damping device 14 , which carries a rotational damper 20 . A pinion 10 is mounted on the spindle of the rotational damper 20 .
The carrier 7 is provided with a groove 15 in which a slider 8 is horizontally slidably mounted. The slider 8 has a rack profile 16 meshing with the pinion 10 . A tension spring 12 is fixed on the one hand to the slider 8 and on the other hand to the carrier 7 .
The slider 8 further has a slider abutment 9 which projects through a slot in the pull out rail 6 . An abutment 11 is provided, for the slider 8 , on the support rail 4 at the body side.
When a drawer 2 is opened, the tension spring 12 pulls the slider 8 into the damping position. When now the drawer 2 is closed the slider abutment 9 strikes against the abutment 11 at the body side, whereupon no further relative movement occurs between the slider 8 and the body rail 4 . The pull out rail 6 however is moved further rearwardly together with the housing 7 and thereby the pinion 10 which rolls against the rack profile 16 is rotated and the rotational damper 20 supported on the carrier 7 comes into action.
When the drawer 2 is opened the slider 8 is moved by the tension spring 12 into the initial position again, that is to say into the damping position.
Disposed in the carrier 7 , at the side which is towards the front panel member 2 of the drawer, is a retaining element or holding jaw 17 which, for example, is formed from a rubber or a plastic material involving a high degree of friction.
In the embodiment shown in FIGS. 1 and 2 the rotational damper 20 is mounted slidably with the pinion 10 in longitudinal slots 13 in the carrier 7 .
The longitudinal slots 13 are oriented to incline upwardly in a direction towards the front panel member 2 of the drawer and lie in the resultant of the forces which act in the damping operation on the rotational damper 20 . The rotational damper 20 is therefore pressed with a sufficient force against the retaining element 17 .
When the drawer 2 is closed, after the abutment 9 of the slider 8 has hit against the abutment 11 at the body side, then as stated above relative movement occurs between the carrier 7 and the slider 8 . By virtue of that relative movement, the rotational damper 20 is urged against the retaining element 17 and thereby a housing of the rotational damper 20 is held non-rotatably in the housing 7 by the retaining element 17 . In other words, the pinion 10 rotates a rotational drummer piston disposed in the housing of the rotational damper 20 and the damping device 14 is in action.
When, in contrast, the drawer 2 is opened, the rotational damper 20 slides in the longitudinal slots 13 , as shown in FIG. 2, downwardly and thus rearwardly relative to the carrier 7 . The housing of the rotational damper 20 is thus disposed at a spacing from the retaining element 17 , and the entire rotational damper 20 is rotated together with its housing when the relative movement occurs between the slider 8 and the pinion 10 . No damping or braking action thus takes place.
In the embodiments shown in FIGS. 3 to 10 the rotational damper 20 is mounted on the carrier 7 by means of a rocker member 21 . The rocker member 21 is tiltable about an axis 18 . The axis 18 , by means of which the rocker member 21 is supported on the carrier 7 , is set back, with respect to the depth of the article of furniture, in relation to a spindle 19 by means of which the rotational damper 20 is mounted with the pinion 10 on the rocker member 21 .
When unloaded, therefore, the rocker member 21 with the rotational damper 20 will assume the position shown in FIG. 4, that is to say the housing of the rotational damper 20 is disposed at a spacing from the retaining element 17 . However, as soon as the abutment 9 of the slider 8 hits against the abutment 11 at the body side upon closure of the drawer 2 , a relative movement again occurs between the slider 8 and the carrier 7 and the rocker member 21 is urged with the rotational damper 20 in the direction of the arrow A in FIG. 3 against the retaining element 17 , whereby the housing of the rotational damper 20 is held non-rotatably and the damping action of the rotational damper 20 comes into effect. The rotational damper 20 is moved upon movement of the rocker member 21 in approximately parallel relationship with the direction of movement of the slider 8 .
In the embodiment shown in FIGS. 3 to 5 the retaining element 17 is a rubber or plastic member which holds the housing of the rotational damper 20 by frictional engagement.
In the embodiment shown in FIGS. 6 and 7 the retaining element 17 and the housing of the rotational damper 20 are provided with a directional tooth locking means 23 . The function of the damping device 14 is the same as in the above-described embodiment. The housing of the rotational damper 20 is held fast by the retaining element 17 ; by means of the directional tooth locking means 23 ; instead of by frictional engagement.
In the embodiment shown in FIGS. 8 to 10 , a spring 22 , which is in the form of a leg spring, is mounted on the carrier 7 and urges the rocker member 21 in the direction of the arrow B in FIG. 9 . In other words, if no, or only a slight, pressure is applied to the pinion 10 by the slider 8 , the rocker member 21 is urged in the direction of the arrow B by the spring 22 and the housing of the rotational damper 20 is certain to be moved away from the retaining element 17 so that the drawer can move into the closed position unimpeded by the damping device 14 .
What is common to all embodiments is that the pinion 10 of the rotational damper 20 and the rack profile of the actuating member are constantly in engagement with each other.
The pull out guide assembly according to the invention is preferably provided with a drawer retraction device as is described for example in EP 0 391 221 B1. In that case the spring of the drawer retraction device must be stronger than the tension spring 12 so that the drawer 2 is certain to be closed. | A damping device ( 14 ) for movable furniture parts comprising a fluid damper which is in the form of a rotational damper ( 20 ) and which includes two members which are rotatably movable relative to each other, namely a housing and a drum disposed in the housing. A damping fluid, for example a silicone oil, is disposed in the housing. During the damping action one of the two members is rotated by an actuating member and the other member is held fast. The rotational damper ( 20 ) is radially displaceably mounted and during the damping action is pressed by the actuating member against a retaining element ( 17 ). | 0 |
This application is a continuation of now abandoned application Ser. No. 07/436,790, filed on Nov. 15, 1989.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a rotating head apparatus used for, in for instance, a magnetic recording apparatus.
2. Description of the Prior Art
The conventional rotating head apparatus hitherto used has a structure as shown in FIG. 23 and FIG. 24. That is, a rotary cylinder 2 which rotates at 1,000 rpm -2,000 rpm relative to a magnetic tape 1 and a stationary cylinder 3, which does not rotate, guide the magnetic tape 1. On the stationary cylinder 3, a lead 4 is provided for regulating the position of the magnetic tape 1 at the time of running. A rotating head 5 mounted on the rotary cylinder 2 is projected by several 10 microns outward from the periphery of the rotary cylinder 2. The number 6 represents a recess in which the magnetic head is disposed.
The rotary cylinder 2 rotates at 1,000-2,000 rpm and at the same time the magnetic tape 1 runs while being wound slantwise (helical) with a specified angle around the rotary cylinder 2 and the stationary cylinder 3 with a specified tape tension. The rotating head 5, which is mounted on the rotary cylinder 2 by projecting itself by several 10 microns outward from the periphery of the rotary cylinder, rotates by making contact with the tape 1.
With the conventional structure, an air film 7 is formed on the periphery of the cylinder as shown in FIG. 24. So, the contact state of the rotating head 5 with the magnetic tape 1 changes at different positions in the helical path, for example at a tape contact inlet (A), a tape contact middle position (B) and a tape contact outlet (C). Thus, as shown in FIGS. 25(A)-25(C), assuming that an angle α is be an angle formed in the tape width direction, perpendicular to the tape running direction, by the center line n of the magnetic gap of the rotating head and a normal line m to a tape-contacting surface of the rotating head contacting the magnetic tape, the angle α changes depending on the scanning position of the rotating head.
Furthermore, because the state of air film 7 varies as the cylinder rotating speed varies, there is such a problem that the angle o formed between the lines m and n varies in accordance with the variations in the cylinder rotating speed.
Experimental data is shown in FIGS. 28A to FIG. 31C on the contact state made between rotary head 5 and tape 1. The data in FIGS. 28A to FIG. 31C represent measurements of a distance between micrometer 9 and the tape 1 at the respective points of the tape contact inlet (A), middle position (B) and tape contact outlet (C), by scanning with the micrometer in a cross direction of the tape and also by changing the rigidity of the tape and the cylinder rotating speed in an experimental installation shown in FIG. 27. Experimental conditions are shown respectively as follows: in FIG. 28 cylinder rotating speed 1,800 rpm, high tape rigidity; in FIGS. 29A-29C, cylinder rotating speed is 1,800 rpm, at a low tape rigidity; in FIGS. 30A-30C, cylinder rotating speed 5,400 rpm, low tape rigidity; and in FIGS. 31A-31C, the cylinder rotating speed is 5,400 rpm, at a high speed rigidity. FIGS. 32A and 32C show experimental data, obtained through the use of an interference fringe, of the contact state between the head and the tape at the position of the tape contact inlet (A) and the tape contact outlet (C), and from these figures it becomes clear that the center of contact between the head and the tape at the tape contact inlet (A) locates higher than the head end, while at the tape contact outlet (C) the center of contact between the head and the tape locates lower than the head end. From this experimental data, it is understood that the contact state between the tape and the head varies with the variation of the cylinder rotating speed, tape rigidity, and the scanning position of the rotating head.
FIGS. 25(A)-25(C) and FIGS. 26A-25(C) show examples of contact states between the rotating head 5 and tape 1 of the conventional rotating head apparatus, in which the tape rigidity of FIGS. 26(A)-26(C) is higher than that of FIG. 25, where α is the angle formed between the lines m and n. As the space to the tape 1 near the magnetic gap becomes larger in accordance with the angle α which becomes larger, signal recording and reproducing performances reduce with larger space loss. With the conventional rotating head apparatus, the existence of larger value α (for example, at the tape inlet (A) and the tape outlet (C) in FIG. 24) often causes the problem of lowering the signal recording and reproducing performances. The variations in tape rigidity and thickness following the variation in the kind of the tape also cause a problem of changing the value α as shown in FIGS. 25(A)-25(C) and FIGS. 26(A)-26(C).
Assuming that an angle β is an angle formed in the tape longitudinal direction, parallel to the tape running direction, by the center line n of the magnetic gap of the rotating head 5 and the normal line m to the contact surface between the tape 1 and the rotating head 5, the space to the tape 1 near the magnetic gap becomes larger as the value of β becomes larger, so that space loss becomes larger, thereby lowering the performances of signal recording and reproducing. Such a case occur frequently such that the value of β does not become 0 as shown in FIGS. 33A-33C and FIGS. 34A-34C. FIG. 35 shows measurements of the value β made in accordance with the cylinder rotating speed and scanning position of the head. The value of β, like that of α, changes in accordance with the variations of the cylinder rotating speed, tape rigidity, and scanning position of the rotating head.
To prevent the change of the angle α or the angle 8 dependent on the scanning position of the rotating head, such a method is known that moves the rotating head in the tape width direction or in the tape longitudinal direction according to the scanning position of the rotating head as shown in Japanese Patent Publication No. 61-144721 published on Jul. 2, 1986 and Japanese Patent Publication No. 63-4249 published on Jan. 28, 1988.
Japanese Patent Publication No. 61-144721 discloses a rotating head apparatus which has a means for detecting a rotational position of the rotating head relative to the stationary cylinder, and a means for moving the rotating head in a direction parallel to the tape running direction according to the detected rotational position of the rotating head so as to keep an optimum contact (β=0) between the rotating head and the magnetic tape at any scanning position. Japanese Patent Publication No. 63-4249 discloses a rotating head apparatus which has a means for detecting a rotational position of the rotating head relative to the stationary cylinder, and a means for moving the rotating head in a direction parallel to the tape width direction according to the detected rotational position of the rotating head so as to keep an optimum contact (α=0) between the rotating head and the magnetic tape at any scanning position.
To move the rotating head as above, the apparatus has a circuit for generating from an output signal of the rotational position detecting means a drive voltage signal which is a cyclic saw-tooth waveform signal synchronized with the rotation of the rotating head. The rotating head is driven by the drive voltage signal to change the amount of its deviation gradually in each scanning cycle.
However, in these prior art references, no consideration is made on the change of the angle α or the angle β dependent on the kind of the tape or on the rotational speed of the rotating head.
SUMMARY OF THE INVENTION
An object of this invention is to provide a rotating head apparatus for preventing signal recording or reproducing performance from lowering, by improving the contact state of a magnetic tape and a rotating head in accordance with variations in the kind of the tape and the cylinder rotating speed by keeping the value of α or β almost 0°.
In order to achieve the above object a rotating head apparatus of this invention comprises a stationary cylinder for guiding a running magnetic tape wound thereon slantwise at a specified angle, a rotating head which rotates at a specified rotating speed and has a magnetic gap for recording signals on or reproducing signals from the magnetic tape, a moving means for moving the rotating head, a discriminating means for discriminating the kind of the magnetic tape or the rotating speed of the rotating head, and a control means for controlling the moving means in accordance with an output of the discriminating means so that the magnetic gap is placed in an optimum position relative to the magnetic tape.
In a preferred embodiment, the control means includes a rotational phase detector for detecting a rotational phase of the rotating head, a saw-tooth waveform voltage signal generator for generating from an output of the rotational phase detector a periodic saw-tooth waveform voltage signal synchronized with the rotation of the rotating head, and a voltage level control circuit for controlling the peak level of the saw-tooth waveform voltage signal according to the output of the discriminating means. The moving means is driven by the saw-tooth waveform voltage signal with the controlled peak level.
This invention prevents signal recording or reproducing performance from lowering based on the above structure, by decreasing space loss with the aid of optimum control of the position to stabilize the contact state between the tape and the head.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a cross-sectional view showing a major part of a rotating head apparatus of a first embodiment of the prevent invention;
FIG. 2 is a perspective view showing a part of the rotating head apparatus of the first embodiment of the present invention;
FIG. 3 is a circuit diagram showing a control circuit of the first embodiment of the present invention;
FIGS. 4a-4f signal waveform diagrams for explaining an operation of a driving circuit of the first embodiment of the present invention;
FIGS. 5A-5C are diagrams for explaining an operation of the first embodiment of the present invention;
FIGS. 6A-6C are cross-sectional views showing a major part of the rotating head apparatus of the first embodiment of the present invention, in which FIG. 6A shows an enlarged view at the tape contact inlet; FIG. 6C shows an enlarged view at the middle position, and (C) shows an enlarged view at the tape contact outlet;
FIGS. 7A-7C are cross-sectional views showing the major part of the rotating head apparatus of the first embodiment of the present invention;
FIG. 8 shows one example of a detecting means of the first embodiment of the present invention;
FIG. 9 is a cross-sectional view showing a major part of a rotating head apparatus of a second embodiment of the present invention;
FIG. 10 is a cross-section view showing a major part of a rotating head apparatus of a third embodiment of the present invention;
FIG. 11 is a circuit diagram showing a control circuit of the third embodiment of the present invention;
FIG. 12 and FIG. 13 are signal waveform diagrams showing an operation of a driving circuit of the third embodiment of the present invention;
FIG. 14 is a cross-sectional view showing a major part of a rotating head apparatus of a fourth embodiment of the present invention;
FIG. 15 is a perspective view showing a structure of a major part of the rotating head apparatus of the fourth embodiment of the present invention;
FIGS. 16A-16C are diagrams showing an operation of the rotating head of the fourth embodiment of the present invention;
FIG. 17 is a circuit diagram showing a control circuit of the fourth embodiment of the present invention;
FIGS. 18s-18t are signal waveform diagrams showing an operation of a driving circuit of the fourth embodiment of the present invention;
FIG. 19 is a sectional view showing a structure of a major part of a rotating head apparatus of a fifth embodiment of the present invention;
FIG. 20 is a circuit diagram showing a control circuit of the fifth embodiment of the present invention;
FIGS. 21u -21w and FIGS. 22u-22w are signal waveform diagrams showing an operation of a driving circuit of the fifth embodiment of the present invention;
FIG. 23 is a side view of a conventional rotating head apparatus;
FIG. 24 is a top view of the conventional rotating head apparatus;
FIGS. 25(A)-25(C) are cross-sectional views showing a major part of the conventional rotating head apparatus, in which FIGS. 25A shows an enlarged view at the tape contact inlet; FIG. 25(B) shown an enlarged view at the middle position, and FIG. 25(C) shows an enlarged view at the tape contact outlet;
FIGS. 26(A)-26(C) are cross-sectional views showing the major part of the conventional rotating head apparatus, in which FIG. 26(A) shows an enlarged view at the tape contact outlet; FIG. 26(B) shows an enlarged view at the middle position, and FIG. 26(C) shows an enlarged view at the tape contact outlet;
FIG. 27 is a schematic diagram showing an experimental apparatus;
FIGS. 28A through FIG. 31C show experimental data;
FIGS. 32A and 32C show is experimental data in which contact state between the head and the tape is seen at the positions of the tape contact inlet (FIG. 32A) and the tape contact outlet (FIG. 32C) by utilizing interference fringes;
FIGS. 33A-33C are cross-sectional view of a part of the conventional rotating head apparatus, in which FIG. 35A shows an enlarged view at the tape contact inlet; FIG. 33B shows an nlarged view at the middle position, and FIG. 33C shows an enlarged view at the tape contact outlet;
FIGS. 34A-34C are cross sectional views of a part of the conventional rotating head apparatus, in which FIG. 34A shows an enlarged view at the tape contact inlet; FIG. 34B shows an enlarged view at the middle position, and FIG. 34C shows an enlarged view at the tape contact outlet; and
FIG. 35 shows measurement data.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a structure of a rotating head apparatus of a first embodiment of the present invention. In this embodiment, a rotating head is moved in a direction perpendicular to the tape running direction to keep in optimum contact with a tape according to the kind of the tape. In FIG. 1, a rotating head 14 attached to a head mounting table 15 which is made of an insulating material is fixed to a rotary cylinder 11 via electromechanical conversion elements 16 and 17, and a frame 18. The head 14 may be one of a pair of rotating heads which are 180° apart from each other, for example. A slip ring 19 as a known means transmits a signal from a control circuit 20 to the electromechanical conversion elements 16 and 17. The electromechanical conversion elements 16 and 17 are displaced by an electrical signal. The details of the electromechanical conversion elements 16 and 17 are shown in FIG. 2. In FIG. 2, a thin phosphor bronze plate 17 is supported by a frame 18, and provided on opposite major surfaces thereof with piezoelectric ceramics 16a and 16b at the middle part. The plate 17 allows an electrical voltage to be supplied to the piezoelectric ceramics 16aand 16b. A flexible material like the phosphor bronze plate 17 shows such a behavior as bending like a bow when a voltage is supplied to the piezoelectric ceramics 16a and 16b. The bending direction is determined by the characteristics of the piezoelectric ceramics and the polarity of the voltage to be applied. Such a structure is widely known as the piezobimorph. Therefore, supplying a voltage will bend the electromechanical conversion elements 16 and 17 upward as shown in FIG. 5(A). On the contrary, reversing the polarity of the voltage to be applied to each piezoelectric ceramic will bend the elements downward as shown in FIG. 5(C). When no voltage is applied, they become parallel with the frame 18 as shown in FIG. 5(B). In this way, the rotating head moves pivotally to keep optimum contact with the tape.
Keeping always the value of α zero will allow a stable signal transmission between the rotating head 14 and the tape 13, by changing a head support in accordance with the contact state between the rotating head 14 and the tape 13 as shown in FIG. 5A-5C against the variation of normal line m to the contact plane of the tape 13 and the rotating head 14, as shown in FIGS. 25(A) through 25(C) (if the rigidity of the tape is low) or in FIGS. 26(A) through 26(C) (if the rigidity of the tape is high).
Namely, in the position (angle of rotation θ=0°) at the tape contact inlet (A) in FIG. 6A, because the angle α formed between the normal line m to the contact surface of the rotating head 14 with the tape 13, and the center line of the magnetic gap of the rotating head 14 is larger, the value of o is made nearly 0° by applying a control voltage as shown in FIG. 5(A) from the control circuit 20.
Following this, while the rotating head 14 moves from the position of the tape contact inlet (A) (angle of rotation θ=0°), the control voltage from the control circuit 20 is set so that the angle α will always become nearly 0°. Therefore, at the middle position (B), the position of the tip of the rotating head 14 (magnetic gap) comes to the position as shown in FIG. 6(B). Even while the position comes from the middle position (B) (angle of rotation θ=90°) to the position (angle of rotation θ=180°) of the tape contact outlet (C), the control voltage from the control circuit 20 is set so that the angle α will always come to nearly 0°.
Therefore, at the position of the tape contact outlet (C), the position of the tip (magnetic gap) of the rotating head 14 will come to the position as shown in FIG. 6(C). By setting the control voltage so that the angle α rotating head 14 becomes always 0° as shown in FIGS. 6(A), 6(B), and 6(C), the simple structure as shown above allows the contact state with the tape 13 near the magnetic gap of the rotating head 14 to be optimum, thus making it possible to keep the space loss at a minimum.
However, when the kind of the tape is changed as shown in FIGS. 25(A)-25(C) and FIGS. 26(A)-26(C) of the conventional example for example, the contact state (the value of α) between the tape and the head also changes. Therefore, by setting a selecting switch 32 (See FIG. 1) to select the corresponding kind of the tape, the control circuit 20 sets the control voltage so that the value α is set to 0° in accordance with an output of the selecting switch 32.
First of all, selecting the kind of the tape with the selection switch 32 will cause the control circuit 20 to generate an output voltage according to the selected kind of tape and drive the electromechanical conversion elements 16 and 17 through the slip ring 19, and will then allow the locus of movement of the rotating head 14 to be changed in accordance with the selected kind of tape. FIGS. 7A-7C show a contact state between the head 14 and tape 13 in case the rigidity of the tape is higher than that of the tape in FIGS. 6A-6C. Although the operation in FIGS. 7A-7C show is the same as in FIG. 6, the value of α is smaller than that of FIGS. 6A-6C because the rigidity of the tape is higher than that of FIGS. 6A-6C (see FIGS. 25(A)-25(C) and 26(A)-26(C). Therefore, a smaller amount of deviation of the head than the case of FIGS. 6A-6C is caused by lowering the value of the control voltage.
Then, detailed explanation will follow for the control circuit 20 and the selecting switch 32 in FIG. 1.
FIG. 3 shows a circuit diagram of the circuit 20 and switch 32 for generating a voltage applied to the piezoelectric ceramic 16. Explanation on the circuit operation of FIG. 3 follows below using FIGS. 4a-4f.
The operation reference signal of the circuit shown in FIG. 3 is generated by detecting the rotary phase of the rotating head 14 by a pulse generator 25. This is carried out by arranging two magnets 22 on the lower surface of the rotary plate 21 which rotates in one body with the rotating head 21 and a coil 23 and a yoke 24 opposing the magnets 22 as shown in FIG. 1. Namely, the relationship of the arrangement among the rotating head 14, magnet 22 and yoke 24, and coil 23 is made workable so that magnet 22 and yoke 23, and coil 23 will come closer each other when the rotating head 14 plunges into the tape 13. Then, when the rotating head 14 plunges into the tape 13, the magnet 22 passes near the coil 2 and then an instantaneous current is generated on the coil 23, thus a trigger is generated by the pulse generator 25. Assuming that the rotating head 14 is rotating at 30 revolutions per second, a trigger with a period of 1/60 second is generated, so that a pulse with a period of 1/60 second as shown in FIG. 4(a) is generated by the pulse generator 25. Therefore, the time at which this pulse (reference) signal is built up and the time at which the rotating head 14 plunges into the tape end approaches to the same time.
When the reference signal approaches to a high voltage, transistors 27 and 28 are closed via a resistor 26, so that a differential waveform as shown in FIG. 4(b) is generated by a capacitor 30 and a resistor 31 at point b. The peak value of this differential waveform is the value determined by a power source 33 (33a-33c). That is, with the selection switch 32 (32a-32c), turning a selecting button 32a to ON will make the peak value E 1 of the power source 33a, turning a selecting button 32b to ON will make the peak value E 2 of the power source 33b, and turning a selecting switch 32c to ON will make the peak value E 3 of the power source 33c. Thereafter, an explanation will follow of the selecting switch 32a turned to ON. In this case the peak value comes to E 1 .
When the reference signal comes to a low voltage, the transistors 27 and 28 become open, so that the electrical charge of the capacitor 30 is discharged through a diode 34. Also, the reference signal controls a transistor 36 via a resistor 35. Because the transistor is closed when the reference signal is at the high voltage, the charge on a capacitor 38 is almost zero. However, when the reference signal is at the low voltage, the transistor 36 opens and the charge of the capacitor 38 will rise at the rate of a time constant to be determined by a resistor 37 and the capacitor 38. That is, at the point C in FIG. 3 a voltage waveform as shown in FIG. 4(C) is generated in accordance with the reference signal. Therefore, the waveform in FIG. 4(C) is converted into a waveform as shown in FIG. 4(d) by an inverting amplifier 39. Furthermore, since adding a signal in FIG. 4b and a signal in FIG. 4d by an adder 40 provides a periodic saw-tooth waveform voltage signal as shown in FIG. 4e, applying this signal to the piezoelectric ceramic 16 will allow the rotating head 14 to be at a state as shown in FIG. 5(A) and FIG. 25(A), while to be at a state as shown in FIG. 5(B) and FIG. 25(B), and to be at a state as shown in FIG. 5(C) and FIG. 25(C). In addition, because a selecting switch 32 in FIG. 1 allows the peak value as shown in FIG. 4e to be altered, movement of the head can be changed according to the kind of tape. In case the rigidity of the tape is higher (see FIGS. 26A-26C), the value of α is smaller, so that it is necessary to make the movement of the head smaller. Then assuming E 1 >E 2 , the peak value is made E2 by turning ON the selecting button 32b, thereby leading the signal to be supplied to the piezoelectric ceramic 16 to the one as shown in FIG. 4f. Therefore, the movement of the head becomes smaller than the state where the selecting button 32a is turned ON, thereby making it possible to always make the value of α nearly 0.
As mentioned above, according to the present embodiment, a simple structure allows the contact state between the tape and the rotating head to be improved depending upon the kind of the tape, and can provide a rotating head apparatus which prevents the performance of signal recording and reproduction from lowering.
In the present embodiment, selecting buttons are employed as the selecting switch, it is not confined within the present embodiment only and the same effect is obtainable by turning switches 32a and 32b ON/OFF by use of cassette detection holes 42a and 42b of a cassette 41 as shown in FIG. 8. In FIG. 8, in order to set the switch 32a ON for instance, the cassette detection hole 42a may be closed and the cassette detection hole 42b may be opened. Pins 43a and 43b are to be inserted to the holes 42a and 42b, respectively.
In the present embodiment, although the viewpoint is focused only on the rigidity of the kind of the tape, it is not limited to this embodiment and is possible to control deviation of the head with provisions like the selecting switch by focussing the viewpoint on other factors like tape thickness, etc.
Furthermore, means for moving the rotating head may be constructed as shown in FIG. 9, not only limiting the method as shown above. In FIG. 9, 45 is a lever, 48 is a guide member, the shape of each of parts 45a and 48a is an arc whose center is positioned at the tip of the magnetic gap of a rotating head 14. The lever 45 is tensioned with a tension spring 47 so that it is always in contact with a piezoelectric ceramic 46 and is furthermore tensioned with a tension spring 49 so that the part 45a is in contact with the part 48a. Therefore, the lever 45 turns by expansion of the piezoelectric ceramic 46 with its fulcrum on the center of curvature in a direction of thickness near the magnetic gap on the rotating head 14. The method of applying a voltage to the piezoelectric ceramic 46 may be done in accordance with the kind of the tape as shown in FIG. 4e and 4f by the method described before. According to the embodiment in FIG. 9, there is such an advantage that the scanning locus of the rotating head against the tape 13 becomes straight because the tip of the rotating head does not move.
A third embodiment of the present invention will be described below. In this embodiment, a rotating head is moved in a direction perpendicular to the tape running direction according to the rotation speed of the cylinder to keep optimum contact with a tape. FIG. 10 shows a cross-section of a major part of the third embodiment of the present invention, and the construction is almost the same as the first embodiment but a control circuit 50 is different. As is seen from the experimental data in FIG. 28A to FIG. 31C, the higher the rotational speed of the cylinder, the larger the amount of lifting of the tape, and thus the amount of movement of the head should be larger as the amount of curling becomes larger at the tape end. In the first embodiment, the control voltage is supplied in accordance with the kind of the tape, but in the third embodiment the control voltage in accordance with the rotation speed of the cylinder is supplied to the piezoelectric ceramic. FIG. 11 shows a circuit diagram showing the details of the control circuit 50. In FIG. 11 the peak value of the differential waveform is varied in accordance with the rotational speed of the cylinder. Explanation follows with reference to FIG. 11, FIG. 12h-12q, and FIGS. 13h-13qand FIG. 12h-12q show the case in which the rotational speed of the cylinder is at 1800 rpm, and FIGS. 13h-13q show the case in which the rotational speed is at 5400 rpm. When a pulse generated by the pulse generator 25 in the same manner as in the first embodiment closes a transistor 52 via a resistor 51 when it at a high voltage, a constant current 53 is discharged by the transistor 52. Therefore, no current will flow to point i in FIG. 11. Then, as the transistor 52 will open when the generated pulse reaches to a lower voltage level, the voltage waveform as shown in FIG. 12-i or FIG. 13-i will be generated because a part of constant current 53 flows to a capacitor 54 at point i in FIG. 11. Supposing that a peak value of FIG. 12-i be Ea and a peak value in FIG. 13-i is Eb, a relationship of Ea>Eb arises from the figure. Therefore, supposing the value of a power source 56 is Ec (Ea>Ec>Fb), a voltage waveform as shown in FIG. 12-J or FIG. 13-j will arise at point j in FIG. 11 by a comparator 55. By applying this voltage waveform to a monostable multivibrator 57 whose time constant T is 1/60 sec. or more, a voltage waveform as shown in FIG. 12-k or FIG. 13-k is generated at point k in FIG. 11. That is, the rotational speed of 1,800 rpm will correspond to a high voltage while the rotational speed of 5,400 rpm will correspond to a low voltage. Therefore, supposing that the value of a power source 60 is Ed, a resistor 61a is Ra, a resistor 61b is Rb, the value of a resistor 61c is Rc, when a transistor 59 will be closed through a resistor 58 when point k in FIG. 11 is at a high voltage, the current from the power source 60 will flow to the transistor 59, and the voltage at point l in FIG. 11 becomes Ed·Rb / (Ra+Rb).
Also, when the transistor 59 opens when point k in FIG. 11 is at a low voltage, the voltage at point l in FIG. 11 becomes Ed·(Rb+Rc) / (Ra+Rb+Rc). Supposing here that Ra=Rb=Rc, the voltage at point l is Ed/2 at the rotational speed of 1,800 rpm, and is 2Ed/3 at the rotational speed of 5,400 rpm. This value corresponds to the peak value in the embodiment, and the remaining circuit configuration is the same as in the case of FIG. 3. Therefore, the voltage waveform at point q in FIG. 11 becomes as shown in FIG. 12-q or FIG. 13-q.
By applying the voltage wave q as outputted from the control circuit 50 to the piezoelectric ceramic 16, the head 14 is moved. As mentioned before, the higher rotational speed of the cylinder causes the greater lifting of the tape, and thus the resultant tape curling becomes larger. But, as seen from FIG. 12-q and FIG. 13-q, the optimum contact between the head and the tape can be kept regardless of the cylinder rotation speed because the amount of movement of the head becomes larger at the higher cylinder rotation speed.
Although in this embodiment a case is shown that two kinds of cylinder speeds 1,800 rpm and 5,400 rpm, are used with one cylinder, it is not limited within the scope of this embodiment along, i.e. such rotational speeds as 1,800 rpm and 3,600 rpm will be also applicable. Also, the method of deviating the head is not limited to the present embodiment alone.
A fourth embodiment of the present invention is shown. In this embodiment, a rotating head is deviated in a direction parallel to the tape running direction according to the kind of the tape to keep in optimum contact with the tape. FIG. 14 is a structural view showing the fourth embodiment of the present invention. A rotating head 74 mounted on a head mounting table 75 made of an insulating material is fixed to a rotary cylinder via electromechanical conversion elements 76, 77 and a frame 78. A slip ring 79, as is already known, is used for transmitting signals from a control circuit 80 to the electromechanical conversion elements 76 and 77. The electromechanical conversion elements 76 and 77 cause a displacement by an electrical signal, and the details of the electromechanical conversion elements 76 and 77 are shown in FIG. 15. In FIG. 15, the thin phosphor bronze plate 77 is supported with a frame 78, and is provided on its opposite major surfaces at the middle thereof with piezoelectric ceramics 76a and 76b. Therefore, as shown in FIGS. 16(A) or 16(B) by applying a voltage, the electromechanical conversion elements 76 and 77 will bend in the direction of the arrow, that is, parallel to the tape running direction. When not applying a voltage, the elements 76 and 77 become parallel with the frame 78 as shown in FIG. 16(C). By shifting the head in this manner, keeping the value of β always 0° will allow stable signal transmission to be made between the rotating head 74 and the tape 73.
However, a variation in the kind of the tape, for example, as shown in FIGS. 33A-33C and FIGS. 34A-34C changes contact state (value of β) between the tape and the head. So by setting a selection means 92 (see FIG. 14) to select the kind of the control circuit 80 generates a proper voltage in accordance with an output of the selection means.
The locus of rotary movement of the rotating head 74 is changed according to the kind of the tape, by first selecting the kind of the tape with the selection means 92, and moving the electromechanical conversion elements 86 and 77, through the slip ring 79 with an output voltage of the control circuit 80 depending on the selected kind of the tape.
In case the rigidity of the tape is small according to experimental results in FIGS. 33A-33C and FIGS. 34A-34C, the amount of head movement may be increased by increasing the value of the control voltage because the value of β is larger than the case that the rigidity of the tape is high.
Explanation will follow in detail with regard to the control circuit 80 and the selection button 92 is FIG. 14. FIG. 17 shows a circuit configuration of the control circuit 80 and the selection switch 92 (92a-92c) to supply voltage to the piezoelectric ceramic 76. The motion reference signal of the circuit shown in FIG. 17 is generated by detecting the rotary phase of the rotating head 74 by a pulse generator 85 (FIG. 18-s). Explanation for this is omitted as this is carried out in the same method as the first embodiment. As transistors 87 and 88 are closed via a resistor 86 when the reference signal becomes a higher voltage, a differential waveform is generated by a capacitor 90 and a resistor 91 at part t (FIG. 18-t). The peak level of the differential waveform is a value to be determined by power sources 93a-93c. Here, the construction of the selection switch 92 (92a-92c) is arranged in such a manner that in FIG. 17 setting a selection switch 92a ON makes the peak level Ea of the power source 93a, setting a selection switch 92b ON makes the peak level Eb of the power source 93b, and setting a selection switch 92c ON makes the peak level Ec of the power source 93c. In this connection, supposing Ea>Eb, setting the selection switch 92a ON makes the peak level Ea, and the signal to be supplied to the piezoelectric ceramic 76 becomes as shown in FIG. 18-t. The condition of the selection switch 92b being ON makes the peak level Eb, and the signal to be supplied to the piezoelectric ceramic 76 becomes as shown in FIG. 18 t'. Therefore, the amount of head movement allows the value of β to be always nearly 0° as it can be changed according to the kind of tape, by turning the switch 92a ON when the rigidity of the tape is lower while when the rigidity of the tape is higher by turning the switch 92b ON.
According to the present embodiment as above, improvement on the contact state between the tape and the rotating head to be made in accordance with the kind of the tape in a simple construction provides a rotating head apparatus which protects deterioration of performance of signal recording or reproduction.
In the present embodiment a selection means was made of a selecting switch, however, it is not only limited to such embodiment alone, but such a configuration also provides the same effect by turning switches ON and OFF with use of a cassette detection hole (see FIG. 8).
In this embodiment the kind of the tape is depended on rigidity alone, but it is not limited to it, moreover, controlling the quantity of the head deviation by depending on such other factors as tape thickness may be applicable.
An explanation follows below for a fifth embodiment of the present invention. In this embodiment, a rotating head is moved in a direction parallel with the tape running direction according to the cylinder rotating speed to keep optimum contact with the tape. FIG. 19 shows a cross-section showing a major part of the fifth embodiment of the present invention, in which the configuration is almost the same as that of the fourth embodiment, but differ in a control circuit 100. In FIG. 35, as is known in the experimental data, it is necessary to make the amount of head movement larger at the higher rotational speed of the cylinder at which the amount of the tape lift becomes bigger.
In the fourth embodiment, a control voltage in accordance with the kind of the tape is supplied to the piezoelectric ceramic 76, but in the fifth embodiment a control voltage in accordance with the cylinder rotational speed is supplied to the piezoelectric ceramic 76.
FIG. 20 shows a circuit diagram showing the details of the control circuit 100, and differs from the circuit as shown in FIG. 17 in a part of selecting means (switch 92, power supply 93). In FIG. 20, the peak level of the differential waveshape is varied in accordance with the cylinder rotational speed. The explanation will follow hereinafter by using FIGS. 21u-21w and FIGS. 22u-22w . FIGS. 21u-21w shows the case of the cylinder rotational speed of 1,800 rpm while FIGS. 22u-22 w is for speed of 5,400 rpm.
A pulse generator 85 generates a reference pulse signal in the same method as the first embodiment (see point u in FIG. 21u and FIG. 22u). Supposing the value of a power source 101 be Ef, the value of a resistor 102a be Ra, the value of a resistor 102b be Rb, and the value of a resistor 102c be Rc, the voltage at FIG. 21v becomes Ef·Rb / (Ra+Rb), and voltage at FIG. 22v becomes Ef·(Rb+Rc) / (Ra+Rb+Rc) as in the same manner as that explained in FIG. 11 of the third embodiment. Here, for example, supposing Ra=Rb=Rc, the voltage at point l is Ef/2 at the cylinder rotational speed of 1,800 rpm and 2Ef/3 at a speed of 5,400 rpm. This value corresponds to the peak level in the fourth embodiment, and the remaining circuit configuration is the same as that in FIG. 17. Therefore, the voltage waveform of part w in FIG. 20 becomes as shown in FIG. 21-w or FIG. 22-w.
The head 74 is moved by supplying the voltage waveform w outputted from the control circuit 100 to the piezoelectric ceramic 76 as shown in FIG. 16. As mentioned earlier, the higher cylinder rotational speed causes the larger amount of tape lift. But as is seen from FIG. 21-w and FIG. 22-w, the contact state between the head and the tape is kept stable regardless of the cylinder speed because the higher cylinder rotational speed causes the larger amount of head movement.
The selection of the cylinder rotational speed may not be limited to 1,800 rpm and 5,400 rpm, but may be any other speeds, for example 1,800 rpm and 3,600 rpm. | A rotating head apparatus includes an electromechanical conversion element which moves a magnetic head. The electromechanical conversion element allows the contact state between the tape and a rotating head to be stably optimum by varying a voltage applied to the electromechanical conversion element cyclically and according to an output from a discriminator which discriminates the kind of the tape or the rotation speed of the rotating head. Therefore, the apparatus makes it possible to keep the space loss minimum, and prevents a reduction of the performance of signal recording and reproducing. | 6 |
TECHNICAL FIELD
This application is the U.S. National phase of international application PCT/SEO2/00721 filed 10 Apr. 2002 which designates the U.S.
The present disclosure relates to a method of and a network for delivering streaming data from a streaming server to a client and to devices and servers used in delivering streaming data.
BACKGROUND
Digital communication technology offers convenient ways of distributing and copying data, but few means exist of protecting copyright controlled media against unauthorized access or re-distribution.
Some copyright owners have a strong economic interest of protecting their rights and this has lead to an increasing demand for Digital Rights Management (DRM). Generally, the protecting of copyright restricted data transmitted over an insecure channel requires cryptographic mechanisms such as authorization of legal users and encryption of the data. The management of the rights involves establishing trust relations, managing cryptographic keys and charging as well as a specification of the allowed utilization of the media.
A special difficulty arises in wireless networks or other communication systems exposed to disturbances. Due to the broadcast nature, eavesdropping is potentially very easy, which calls for encryption. But in this case, sensitive authentication information and/or encrypted data may be corrupted by errors during the transmission, which could break or distort the communication. Particularly sensitive data comprise real-time or other streaming media where there is little or no time to repair or re-send corrupted data. Moreover, encryption may have an impact on bandwidth economy, and may computationally overload a thin client such as a cellular telephone.
In the case of severely restricted storage capacity of the receiving device, e.g. a cellular telephone or a so-called “personal digital assistant” (PDA), it is not feasible to include DRM solutions that require large storage capacity. For the same reason it is not suitable or not even possible to have several different DRM solutions in one device. Therefore, a DRM solution should make as much use as possible of some pre-existing security architecture. On the other hand, the restricted environment in such a device also has benefits that should be exploited in a DRM solution. First, the limited storage restrictions are likely to prevent storage of the entire streaming data for later extraction. Second, it is not particularly easy to extract the digital contents from the device in any other shape; i.e. we may consider the device to be, or can with small means be turned into or include a so-called “tamper resistant module”.
Most existing DRM solutions are partly based on “security by obscurity”, i.e. the methods used are kept secret from the users. This makes it difficult to establish a trust in the solution from the point of view of the users. Second, though this obscurity admittedly makes attacks more difficult, this is only true as long as the obscurity is maintained. History has repeatedly shown that when someone eventually manages to reverse-engineer the solution, or when there is a “leak”, security of the system is immediately compromised. Hence, a solution based on publicly known algorithms and protocols as far as possible has great benefits.
STATE OF THE ART
Various methods of content protection and rights management exist, but none is feasible for transmitting streaming data over an insecure medium exposed to disturbances. Solutions that may have some relevance to this subject are listed and briefly commented in the following.
Commonly used terms and abbreviations include the following:
DRM (Digital Rights Management): a general framework that may encompass one or more of the following techniques.
Cryptography, see A. Menezes, P. van Oorschot, and S. Vanstone: “Handbook of Applied Cryptography”, CRC Press, 1997.
Watermarking: a process by which a data producer superimposes digital marks on the actual data so that the combined data can be tied to the data producer and so that the marking is resistant to tampering. That is, it should be difficult to completely remove the marks while maintaining a certain “quality” of the data. Watermarking is normally a software technique.
Copy protection: a process in which data are stored and distributed so as to make copying with a retained quality difficult and/or such that a copy can be traced back to the copier. Full protection usually requires special purpose hardware.
The following protocols for transport of real-time media will be referred to in the description hereinafter:
RTP (Real Time transport Protocol): IETF Proposed Standard for transport of real-time and streaming data, see Schulzrinne, H., Casner, S., Frederick, R., Jacobson, V., “RTP: A Transport Protocol for Real-Time Applications”, IETF Request For Comments RFC 1889.
SRTP (Secure RTP or The Secure Real Time Transport Protocol): IETF Draft; security protocol for RTP encompassing encryption using an error-robust, relatively light-weight stream cipher that adds no extra header for the encryption, which makes transmission using SRTP less bandwidth consuming and less sensitive to disturbances compared to e.g. IPsec.
RTSP (Real Time Streaming Protocol): IETF proposed standard for controlling digital streams, much in the same way as a “remote control” for a audio/video device.
ROHC (RObust Header Compression): IETF Proposed Standard for compression of e.g. UDP and RTP-headers (as of Mar. 5, 2001). The compression decreases the size of the packet, which reduces the probability of bit errors and makes it more suitable for transport over noisy channels. Since SRTP only encrypts the RTP-payload, ROHC and SRTP are fully compatible.
Standardized Solutions
There are several standardization bodies discussing DRM and streaming media, the most mature standards work being the Intellectual Property Management and Protection (IPMP) in Moving Picture Experts Group (MPEG). MPEG IPMP offers a framework for DRM, but does not include the DRM in itself; it intentionally leaves this open for proprietary solutions.
Open Platform Initiative for Multimedia Access (OPIMA) works on the standardization of a framework for access control, content management and protection tools. It works on downloadable and/or replaceable security for Internet and pay TV applications, but does not address the wireless environment.
IETF (or more precisely its research group, IRTF) is presently setting up a study group for DRM.
Proprietary Solutions
The Microsoft Corporation has its Windows Media Rights Manager 7. This solution gives the user a possibility to buy a license at a so called clearing house, which can then be used to play a specific media that can be contained on a CD, in an e-mail or a streaming server. The licenses are tied to the computer, not to the user. The solution aims for the PC market in which both storage and processing resources are not restricted so that special purpose software can be downloaded and executed for the playback.
Verance claims to have a special wireless DRM, but the system seems only to be based on watermarking. Its solution does not seem to incorporate encryption of the streaming media.
E-vue manufactures MPEG-4 compliant encoding and authoring tools. No details are given on the site, but its network solutions are transport protocol independent, which would require inclusion of separate encryption on a higher level.
In the published European patent application EP-1041823 for Toshiba a system for secure MPEG-4 distribution is disclosed. It does not offer a real DRM solution; it mainly specifies how to encrypt MPEG-4 and include it in an RTP frame. After the encryption of MPEG-4, an extra encryption header is added to the payload. The encryption is not done at transport layer and requires special-purpose software and/or hardware.
In the published European patent application EP-1062812 for Intertrust a general DRM solution is disclosed using a so called secure container which could contain streaming media, control information and a device for opening the container and extracting cryptographic keys. No solution is explicitly offered for use in an environment exposed to disturbances. Also, since the keys are in the container, they must be extracted and verified before the streaming can be continued, which would have a large impact on the real-time requirements.
In the published International patent application WO 2000/52583 for Audible Inc. a framework is disclosed for authorization of playback device for playing streaming data, but no reference is made to encryption or ciphering despite the fact that transport over a secure medium is not assumed.
Problems
No DRM solution exists complying with real-time requirements in an environment exposed to disturbances. The existing solutions also require extensive storage in the client and/or special-purpose software and/or hardware. Existing DRM solutions are in general proprietary and do not use standard protocols, which require implementations of several DRM solutions in a client. This may be impossible if the storage capacity is scarce. In addition, the non-disclosure of the algorithms used makes them less credible to most users.
Another problem associated with existing solutions is that the digital rights are issued for a specific hardware or a small set of hardware devices, e.g. a PC and the possibility to copy the media once to a CD, as opposed to a specific user.
SUMMARY
It is an object of the one or more of the disclosed embodiments to provide a method and device for a robust and secure downloading of streaming data, in particular streaming data protected by copyright.
In the method disclosed herein existing secure transport protocols are used, this giving the benefit of an easy extension to DRM. Since cryptographic protection of the data content is already in place, it is in principle only necessary to extend the protocol by suitable AAA-like (Authentication, Authorization, and Accounting) mechanisms.
In the method and network the following components may be used:
A robust, lightweight, and secure standardized real-time transport protocol.
A key distribution mechanism.
A charging service.
A tamper-proof module.
Generally, in the method and network for accessing streaming data, e.g. data protected by copyright, the following events may take place but not necessary in the order given below:
A request or order from a client or client device for streaming data.
Authentication of the client.
Charging.
Transmission of the streaming data
The parts interacting in the access of streaming media generally include a Client or client device, an Order Server (OS) and a Streaming Server (SS), the client ordering the media from the Order Server, the Order Server handling the media order and the Streaming Server delivering the streaming media to the Client.
The method and network offer a simple way of distributing material protected by copyright that is adapted to streaming purposes, real-time, possibly interactive data transfer being a special case. By using a robust protocol in the method and network, they are much more suited for wireless clients and heterogeneous environments than existing solutions. The advantage of using a standardized protocol, like SRTP, WTLS, etc., is that it can be implemented in many devices not only for the purpose of Digital Rights Management and therefore can be reused to significantly save storage capacity. This is crucial for client devices having low capacities such as cellular telephones and PDAs.
The proposed method and network and the components thereof, even the tamper resistant module which can be included in the client device, are or can be based on open standards and known algorithms. Is often difficult to evaluate other DRM solutions because they are partly based on “security by obscurity”, i.e. they may depend on secret procedures or implementations. Since secret algorithms protecting a desired object has a tendency to eventually become public, e.g. the GSM encryption algorithm, DVD encryption algorithms, etc., such solutions are generally considered to be weak in the cryptography region: they are not open to public scrutiny before implementation. In this case, as in all contemporary public cryptography, the strength of the procedure once evaluated will rely on the keys and the key management.
Another advantage of an open, largely standardized solution is that anyone can use it to protect and distribute his/her data. For instance, a relatively unknown “garage rockgroup” or an independent film maker or writer, can in a simple, low cost way, distribute their works to a greater audience in a secure way. One can envision a web-portal hosting producers of such works.
Another advantage, when using the method and network as described herein, for a special-purpose thin client, is that it is much less feasible for a “hacker” to access or store the streaming data than in the case where the receiver is a more open and powerful device such as a personal computer. Though it may still be possible to record an analog output signal, the high quality digital signal should be well protected inside the device. In other words the thin client can for many practical purposes in itself be considered a tamper resistant device. In contrast to the build-your-own environment for personal computers, where it is potentially very simple to bypass a hardware copy protection, it is much easier to obtain security in the more controlled manufacturing of cellular telephones and other portable devices. In fact, manufacturers may obtain security certification of their products.
If this is coupled to an additional DRM module and watermarking, the copyright protection is as good as in any existing solution.
If the Order Server is managed by an operator and the Client has a subscription with this operator, this trust relation can be exercised for authentication and charging purposes. Assuming further that the Streaming Server is a content provider, if an operator and a content provider cooperate with each other, e.g. in the form of a music download portal, the user trusting the operator has a reason to feel more secure against fraud from pirate or spoofing content providers.
The method and network are very flexible in the sense that they can provide different levels of anonymity for the Client depending on the actual implementation. For instance, a totally anonymous solution can be obtained with respect to the Streaming Server, the Order Server, and also possible financial institutions involved, by using anonymous digital payments for access and content payment. On the other extreme end of the spectrum, a very tight connection to the user can be obtained by using an Identity Module and possible watermarking techniques. From the point of view of an operator or a content provider this could be very attractive, since it gives better means for tracking down an unlawful copy to the user who provided the copy.
Since the Streaming Server is housing the media and also can make the final validation of the request before transmitting the data, the Streaming Server has maximum control over the media.
The Order Server initiated request also gives an extra benefit in a multicast scenario, e.g. in Internet TV, Video/Radio Broadcasting.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the methods, processes, instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
While the novel features of the invention are set forth with particularly in the appended claims, a complete understanding of the invention, both as to organization and content, and of the above and other features thereof may be gained from and the invention will be better appreciated from a consideration of the following detailed description of non-limiting embodiments presented hereinbelow with reference to the accompanying drawings, in which:
FIG. 1 is a general block diagram illustrating an elementary network comprising parts involved in a procedure for delivering streaming media from a Streaming Server to a Client which requests the media from an Order Server,
FIG. 2 is a block diagram illustrating the functions of a DRM module of a Client,
FIG. 3 is a block diagram illustrating optional trust management in the network of FIG. 1 ,
FIG. 4 is signalling diagram illustrating steps executed in delivering streaming data,
FIG. 5 is schematic diagram showing the basic parts of a digital ticket,
FIG. 6 is a schematic block diagram of a Client showing some basic components thereof, some of which may be optional and some which are alternatives,
FIG. 7 is a schematic block diagram of an Order Server showing some basic components thereof, some of which may be optional and some which are alternatives, and
FIG. 8 is a schematic block diagram of a Streaming Server showing some basic components thereof, some of which may be optional and some which are alternatives.
DETAILED DESCRIPTION
In a system for ordering and receiving streaming media the interaction of three nodes, a Client 1 , an Order Server (OS) 3 and a Streaming Server (SS) 5 which form an elementary network, will now be described, see FIG. 1 .
The Client 1 may be a device having a limited processing and storage capacity, e.g. a cellular telephone, a PDA, etc, having conventional manual input means and means for rendering streaming data on a display and/or by a loudspeaker, see also the block diagram of FIG. 6 . The Client may optionally have built-in special-purpose DRM tamper-resistant soft- or hardware modules. These modules may be associated with a content provider, a financial institution, or a network operator. The Client may optionally also contain or be connected to an Identity Module (IM), which is a tamper resistant device containing data of the user or a subscription, e.g. a SIM card, a smart card, etc. The IM may be issued by a content provider, a network operator or a third party such as a bank.
The Order Server OS 3 handles the requests from the Client and manages primarily the charging related to the requested media, see also the block diagram of FIG. 7 . The Streaming Server 5 , see also the block diagram of FIG. 8 , houses and manages the streaming data according to conditions set by the Order Server and by the Client.
In a practical situation the Order Server 3 and the Streaming Server SS 5 may be integrated with each other or the tasks described herein that are performed in any of the Order Server and Streaming Server may be allocated to two or more servers.
The procedure for obtaining/delivering streaming media starts with the Client 1 presenting a request for a certain object of streaming media to the Order Server 3 . This request may also contain additional information for charging purposes, such as means of payment, credit card number or other monetary information and desired usage of the streaming data, such as duration, format of media, etc. As a response to the Client request, the Order Server 3 may performs tasks like authentication of the Client, charging and preparation for the transfer of the media object requested. The preparation may include QoS (Quality of Service) allocation, which in turn can be associated with the amount of money that the user is willing to pay for the service. The charging may for instance utilize a pre-existing operator-subscriber relation between the Client 1 and the Order Server 3 , a credit card number provided by the Client or an anonymous, e.g. electronic, payment system. Alternatively some kind of pre-paying mechanism may be used. If the request is granted, the Streaming Server 5 can stream the media object to the Client over a standardized, robust and secure protocol, such as SRTP, WTLS, etc. or other protocols adapted for this purpose. If the media utilization agreement made so allows, the streaming may be controlled by the user via a protocol like the RTSP. An example of this may be a user at a sports arena who wants to see slow motion replays of an ice hockey match event from several different angles. Such control signalling may need to be authenticated so that only the intended receiver of the stream can control it.
The use of a standardized protocol allows that already existing implementations are reused, which is helpful to a client 1 that is thin, i.e., has limited storage resources.
A robust transport allows a relatively high bit error rate without severely affecting performance of the streaming data.
The streaming data is encrypted in order to make it possible to protect the content of the data from any unauthorized entity getting access thereto.
A high-level protocol for Digital Rights Management will now be described in more detail, with a focus on authorization, key management and charging. As mentioned above, the implementation may make use of special purpose soft- or hardware if such exists. Thus, with reference to FIG. 4 a high-level protocol for Digital Rights Management will now be described. The different steps performed in the protocol are denoted by arrows connecting the Client 1 and the Order Server 3 to each other and arrows connecting the Client and the Streaming Server 5 to each other.
Step No. 1, Arrow 11 : Pre-Order
Before the Client 1 actually orders some media object some actions may be taken in communicating between the Client and the Order Server 3 , such as finding information on media type, quality, pricing, previewing, etc. Some of this information can possibly also be obtained from the Streaming Server 5 , such as lists of available media objects, information whether they can be obtained through the Order Server 3 , data types, preview files.
Step No. 2, Arrow 12 : Order
The Client 1 is involved in communication with the Order Server 3 resulting in a formal order or order-request of some specific media object sent from the Client to the Order Server, e.g. over WAS, HTTP or I-mode, certain rights being associated with the order. The receiving of the order request initiates a sequence of actions that may include exchange of security information, such as authentication of the Client, to be used in the order process and/or in the charging process and/or in the ticket creation process to be described below.
Step No. 3, Arrow 13 : Clearing/Charging
The request of step No. 2 also initiates a clearing or charging action, in the normal case where the media object, actually the contents thereof, is charged for. The Client 1 specifies how to pay for the order, in the order message or by some pre-existing agreement, and grants the Order Server 3 the right to charge. The Order Server may optionally be in contact with a clearing house/broker to handle the charging request, such as to check that there is a sufficient amount of money on the user's account, etc.
Step No. 4, Arrow 14 : Ticket Delivery
The Order Server 3 then creates a digitally signed ticket or digitally signed tickets, which it sends back to the Client 1 . Such a ticket is a receipt of the order and contains information of the agreement that is necessary for the Client in order to obtain the requested media object from the Streaming Server 5 and to retrieve the contents thereof. This might be information about the Streaming Server and about requested media, cryptographic information, such as a key and other parameters for the streaming data, and usage rights or conditions, i.e. authorization information, for the requested media, e.g. the number of accesses allowed, initiation and expiration time. When receiving the ticket the Client 1 may check that the contents of the ticket coincides with the previously made order.
Step No. 5: Ticket Forwarding
To initiate the delivery of the media, the whole ticket or preferably a special part of the ticket is sent from the Client 1 to the Streaming Server 5 . Alternatively, information derived from the received ticket can be sent to the Streaming Server. Optionally, the Client may add information on the aspect of the granted rights to the media that is requested in the media session setup step to be described below. Additional data may also be added to cryptographically tie this information to the Client, via the cryptographic information put into the ticket by the Order Server 3 . The Streaming Server verifies the validity of the ticket, e.g. that it still is valid, that it was issued by a legitimate Order Server, that the rights requested by the Client comply with the rights written in the ticket, etc.
Step No. 6: Security Setup
The cryptographic information conveyed in the ticket can either be used directly or to obtain extended authentication and/or to derive additional cryptographic information, such as session (SRTP) keys, separate encryption and integrity protection keys, etc. Such keys may be derived, e.g. by using a key management protocol.
Step No. 7: Media Session Setup
If the ticket is valid, preparation of the actual streaming of media is made. Thus, in order to render the media, certain configuration and manipulation procedures may be necessary, such as configuring codecs, transmitting originating and destination network addresses and ports, fast forward to desired locations, etc. This may be handled by a control protocol, such as the RTSP.
Step, No. 8: Streaming/Charging
After all preparations having been made, the Streaming Server 5 starts streaming the media to the Client 1 in accordance with what is ordered. The Client receives the data and decrypts it, typically “on the fly” in real-time, using the previously obtained key. Optionally, if the agreement allows, the Client 1 may interact with the Streaming Server, using e.g. RTSP, to control the media flow according to what it wishes. Additional charging may be used to allow e.g. volume or time based pricing of media. This type of charging does not require any additional payment from the Client 1 , but rather marks consumption of the ticket, by using up its rights. For example, in the case of time based charging, the ticket may contain some amount of time distributed over a certain set of media. The Streaming Server 5 may record the time used and send receipts to the Client. Similarly, for volume based pricing the Streaming Server may record the amount of data streamed instead of time.
Optionally, if the ticket expires, the Client can again contact the Order Server 3 , in the case where it wishes to continue the streaming. This re-negotiation may use previously exchanged information, and can therefore be a faster and more lightweight transaction to reduce interruption of the data flow. The protocol then proceeds from step No. 5.
Examples of Ticket Content
The digital tickets may contain various information, which may depend on the relations between the Order Server 3 , the Streaming Server 5 and the Client 1 , the existence of a Public Key Infrastructure (PKI), and a hardware identity of the media player, i.e. of the Client. The tickets could contain information on the requested media, the usage conditions allowed and they can also act as receipts or vouchers for the associated economic transaction.
1. If the Order Server 3 and the Client 1 have an operator/subscriber relation, one ticket may contain the session key, e.g. the SRTP key, encrypted with some secret data manifesting the relation, such as a cryptographic key known to the Order Server and which may be contained in an Identity Module in the Client. Another ticket may contain the session key encrypted with a public key belonging to the Streaming Server 5 . The former ticket may act as a receipt for the Client whereas the latter ticket may act as a token to be shown or passed to the Streaming Server at the final request for the media.
2. If the Client 1 has a known public key, the Order Server 3 may leave the generation of the session key to the Streaming Server 5 , and the tickets may not carry this information.
In either case, tickets may optionally contain the identity of the playing device, i.e. of the Client, such as an IP address, a hardware identity etc. Tickets may contain a time stamp, a counter value or something e.g. to indicate the freshness of a ticket or to prevent unauthorized replay. A ticket sent from the Order Server 3 aimed for the Streaming Server 5 may contain a Client identifier, with which the Streaming Server may e.g. watermark the media. It can provide anonymity to the Client except in the case of copyright infringement, in which case the Order Server may reveal the identity connected to this identifier.
Also the tickets may be optionally digitally signed by the Order Server, e.g. with a public key belonging to the Order Server for integrity protection, e.g. to protect against spoofing.
A ticket may e.g. contain the following fields, see FIG. 5 :
A field 31 for general parameters. These parameters may contain information that both the Client 1 and the Streaming Server 5 have to receive, e.g. identities, information on rights, authentication and encryption algorithms.
A field 32 for streaming server specific parameters. The contents of this field cannot be accessed by the client and may contain information necessary for the streaming server 5 to establish a cryptographic relation with the client 1 . A cryptographic key encrypted by the order server 3 , that can be decrypted by the Streaming Server is included. This can be done using the streaming server public key or a key pre-shared between the streaming server and the order server. The same cryptographic key is also included in the client parameters, see below. A special embodiment of the cryptographic key is the SRTP key or a key that can be used to derive the SRTP key.
A field 33 for Client specific parameters. This field may contain information necessary for the Client 1 to establish a cryptographic relation with the Streaming Server 5 . A Client decipherable cryptographic key encrypted by the Order Server 3 that can be decrypted by the Client is included. This can be done by using the Client public key or key pre-shared between the Client and the Order Server.
A field 34 for authentication information. This fields contains information for the streaming server 5 and the client 1 for verifying the validity of the ticket. Either the field contains a signature made with the order server public key which both the streaming server 5 and the client can verify or it contains two parts, one part of which can be verified by the streaming server and another part-of which can be verified by the client. The latter can be achieved using a message authentication code using keys pre-shared by the order server and the streaming server, and by the order server and the client, respectively.
It can be observed that using the procedures described above it is very easy to tie access rights for the media to the user, i.e. an identity, rather than to the hardware to which the downloading is made. This can be accomplished, for instance, by using an Identity Module, such as an SIM card in a mobile terminal, involved in the transactions. Alternatively a credit card number can serve this purpose. By using anonymous, electronic, payments, the access is tied to the user without revealing his identity.
To further enhance security against unlawful copying or playback, the controlled environment in a mobile terminal can be easily extended by an optional hardware security module. Such a module can prevent or control transmission of the data to an external digital device and/or put a watermark to the signal based on the user identity so that the user can be traced. An example of such a module will now be described.
The DRM Module
A DRM module, such as a special purpose tamper resistant integrated circuit or a physically protected device, may be optionally included in the Client 1 to make it even more difficult to prevent unlawful access to the media. In the block diagram of FIG. 2 the functions of such a module 41 for an SRTP based solution are illustrated.
It is preferred that the module at least (1) contain some secret data K 1 stored in a secure memory 43 , such as a cryptographic key, which may be a resource common to or stored in the IM. This data can be utilized to tie the usage rights to a subscriber identity or a device. It may also (2) include a device F 1 , 45 for performing a decryption algorithm or cryptographic one-way function, which takes as input the secret data k 1 delivered from the secure memory 43 on a line 44 comprising an interface a, 46 , and the encrypted SRTP key, as provided on an input line 47 of the module 41 , and produces as output the decrypted SRTP key on a line 49 . A third version (3) the module 41 may also contain the entire SRTP decryption functionality, as illustrated by the block 51 , to which the decrypted SRTP key is provided on the line 49 . The SRTP decryption block 51 receives the data of the encrypted media stream on a line 52 input to the module and delivers a decrypted stream of data on a line 52 output of the module 41 . In this way, the SRTP key, which passes in clear text over an interface B at 53 in the line 49 is entirely protected within the module 41 . In this case it may be advantageous to allow an interface C, 55 at an input line 57 to the module to insert a key into the interface B 53 , so that this SRTP implementation can be reused for other purposes. The function F 1 in the block 45 will in such a case prevent unauthorized use, when somebody attempts to override the DRM functionality.
For example, the use of the DRM module 41 can be as follows. First, the digital ticket is received by the Client 1 and the streaming session is set up, Steps Nos. 5-7.
The encrypted SRTP key is provided to the DRM module 41 on the input line 47 . The key is received by the function block F 1 45 that uses it and the secret information K 1 stored in the secure memory 43 to produce the plain text SRTP key that is provided to the line 49 and appears on the B interface 53 and is accessed by the SRTP decryption block 51 .
The incoming encrypted SRTP stream can now be provided to the DRM module 41 on the input line 52 , is decrypted by the block 51 and the plain text RTP packets are delivered from the decryption block on the output line 52 ′.
It is not possible to extract the keys available on the B interface 53 outside the DRM module 41 . However, it is possible to enter plain text SRTP keys on the C interface 55 in input line 57 and thereby use the DRM module also for decrypting SRTP streams when the plain text SRTP key is known. It can be observed that decrypting and encrypting according to the SRTP can be done in the same way and that the DRM module 41 thus can be used for encrypting as well as decrypting in the case where the plain text SRTP key is known.
Though less likely, in the most extreme case, not shown, the Client could be a wireless device with an antenna input and an e.g. analog audio output, where everything connected in-between is implemented in a tamper resistant way.
Trust Management
To provide trust management in the case where there is no pre-existing relation, and/or authentication between the communicating parties the following optional “certificate” structure can be used, as illustrated by the block diagram of FIG. 3 . With certificate is meant some data confirming the identity and/or rights of a certain party or equipment.
The Order Server 3 may want to ensure that the Streaming Server 5 has the rights to the streaming media for which the Order Server is charging, and this may be demonstrated by utilizing a certificate 61 issued by a rights owner. The ownership of this certificate may be demonstrated to the Order Server at appropriate time/times. This certificate may also be obtained dynamically, during the order process.
The Streaming Server 5 , on the other hand, may want to know that the Client 1 has lawful equipment to handle the media without violating the given rights, and also that the equipment is not malfunctioning and/or stolen or otherwise illegally obtained. For this purpose the Client's equipment may optionally contain a certificate 63 or token issued by the manufacturer of the equipment to prove e.g. that it is original equipment, that it contains the relevant DRM module 41 , etc. If the Order Server 3 is managed by an operator, the Order Server may check whether the equipment is registered in a database, which keeps track of stolen, unauthorized or defective equipment, such as the GSM network's Equipment Identity Register (EIR) 65 , see “GSM System Survey”, Ericsson Student Text, EN/LZT 123 3321 R3A.
The Streaming Server 5 may also want to protect from a “false Order Server” attack, wherein a Client 1 is claimed to have paid for a certain media object without having done so. This may be resolved by the mechanisms described above, if an established agreement between the Order Server 3 and the Streaming Server exists, see the arrow 67 of FIG. 3 . Such an agreement can be created by e.g. the use of a Clearing house certificate, see item 69 , issued by a party that the Streaming Server trusts, and which indicates that the Order Server should be a trusted party. This certificate may also be obtained dynamically, during the order process.
An example will now be described in which a preferred method is executed.
The Client 1 finds, by surfing on the World Wide Web from a wireless terminal, an offer to buy/view a rock video-clip for limited use, e.g. a time period of 30 minutes. The Client also decides to pay a little extra for Hifi-quality audio. The Client specifies the desired media and usage and agrees on the price. The Order Server 3 receives this information and charges, based on a previous contractual agreement with the Client such as e.g. a telephone or Internet subscription. The Order Server also checks the status with the Streaming Server 5 to see that the requested media can be delivered according to the specified conditions or that the Streaming Server reserves capacity therefor. The Order Server produces a ticket and sends it, encrypted and signed/authenticated, to the Client with the following contents: a reference to the requested data, e.g. a file name, a session encryption key for the SRTP stream, a freshness token to protect against replay, information on the validity period, i.e. 30 min, QoS data, and the identity and address of the Client and the Streaming Server. From the ticket, the Client 1 extracts the data, most importantly the session key, and forwards it in encrypted shape to the Streaming Server 5 along with the authorization of the Order Server, i.e. the signature/authentication tag of the Order Server. The Streaming Server extracts the ticket content, checks freshness and authorization of the Client made by the Order Server 3 . Finally, the Streaming Server starts to send the encrypted stream to the Client. The DRM module 41 in the Client produces a decrypted stream, as described with reference to FIGS. 1 , 2 and 4 , which is played on the device. Halfway through the video, the Client is disturbed by a local noise. Over RTSP, the Client “rewinds” the stream a bit, and restarts the media stream sent from the Streaming Server 5 from that point. The Client may need to accompany the control request with the ticket, or information derived therefrom, so that the Streaming Server can check the validity. The RTSP messages may also be authenticated by the Client, so that no one else can take control over the streaming, or do denial of service.
Additionally, the Streaming Server 5 may confirm the transaction of the media with the Order Server 3 so that the charging is not done until the actual media has been delivered. Alternatively, acknowledgments of delivery may be sent from the Streaming Server to the Order Server prior to or during the transaction, to allow flexible charging, e.g. proportional to the time spent or to the amount of data actually delivered.
While specific embodiments of the invention have been illustrated and described herein, it is realized that numerous additional advantages, modifications and changes will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative devices and illustrated examples shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. It is therefore to be understood that the appended claims are intended to cover all such modifications and changes as fall within a true spirit and scope of the invention. | In a procedure for delivering streaming media, a Client first requests the media from an Order Server. The Order Server authenticates the Client and sends a ticket to the Client. Then, the Client sends the ticket to a Streaming Server. The Streaming Server checks the ticket for validity and if found valid encrypts the streaming data using a standardized real-time protocol such as the SRTP and transmits the encrypted data to the Client. The Client receives the data and decrypts them. Copyrighted material adapted to streaming can be securely delivered to the Client. The robust protocol used is very well suited for in particular wireless clients and similar devices having a low capacity such as cellular telephones and PDAs. | 7 |
RELATED APPLICATIONS
[0001] This patent arises from provisional patent application No. 60/732,831 filed on Nov. 2, 2005, entitled “PRINTER DRIVER SYSTEMS AND METHODS FOR AUTOMATIC GENERATION OF EMBROIDERY DESIGNS”, which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] The present disclosure pertains to automatic generation of embroidery designs and, more particularly, to printer driver systems and methods for automatic generation of embroidery designs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] FIG. 1 : Example printer driver system for generating embroidery designs when printing documents via a general purpose computer operating system
[0004] FIG. 2 : Example operations of the example printer driver system of FIG. 1 .
[0005] FIG. 3 : Example operations of an example compositing method used by the printer driver system of FIG. 1 .
[0006] FIG. 4 : Example of Compositing Input Records for a Printing File Containing Three Overlapping Polygons. FIG. 4 shows an original printing file containing three overlapping polygons [two red, one blue (with a hole)]. The output contours (here 5 polygons) are shown on the right.
[0007] FIG. 5 : An example illustration of handing collinear cases: Lines [AB], [CD] and [EF] are collinear segments. Points C, E, F, D are reported as intersection points. As a result, four intersection points are inserted into line [AB], two points are inserted into line [CD]. Note: collinear segments are handled in lines 4 and 15 without increasing the degree of the algorithm.
[0008] FIG. 6 : Segment Pairs using winding rule fill mode illustrated. A is the starting drawing point. Segment pairs are {ABleft, CDright} and {EFleft, PQright} at event point A in (a). Segment pair is {ABleft, PQright} at event point D in (b).
[0009] FIG. 7 : Segment Selection and Duplication
[0010] FIG. 8 : Re-order of Coincident Segments Hit by Scan Ray (i.e. segments have identical end points).
[0011] FIG. 9 : Part (a) shows coincident segments in a Segment Pool and the incorrect hole that may potentially be generated. Part (b) shows the correct result with no coincident/redundant segments.
[0012] FIG. 10 : V 1 is the first event point in this example. After traversal at V 1 , edges in dashed lines are visited edges. At event point P 1 , Edge P 1 P 2 is the start traversal edge. P 1 P 6 is to the left of edge P 1 P 2 and is unvisited. Therefore, traversal edge P 1 P 2 generates a hole. Similarly, at event point M 1 , edge M 1 M 2 is an odd edge and on the left edge V 1 V 7 has been visited, therefore, traversal edge M 1 M 2 generates the outer edge of a new polygonal object.
[0013] FIG. 11 : The left side shows an outline traversal in segment pool A. At vertex D, there are three edges that can be chosen: edge DE, DF and edge DG. Since the traversal started at event point A indicates an outer edge and DE is the leftmost of the three edges (DE, DG and DG) it is chosen. A hole traversal in a segment pool B is shown on the right. At vertex D′, there are three edges that can be chosen: D′E′, D′F′ and D′C′. Because the traversal path starting at A′ indicates a hole, the rightmost edge D′C′ is chosen.
[0014] FIG. 12 : Example graphics metafile. Left: original metafile image, Middle: wire-frame outlines of original metafile records, Right: wire-frame outlines of composite result.
[0015] FIG. 13 : Illustration of example end-cap types and join types.
[0016] FIG. 14 : Illustration of an example method to generate round end-cap stroke path outlines.
[0017] FIG. 15 : Illustration of an example method and generate square end-cap stroke path outlines.
[0018] FIGS. 16 and 17 : Example method to process round type joints.
[0019] FIGS. 18 and 19 : Example method to process miter type joints.
[0020] FIGS. 20 and 21 : Example method to process bevel type joints.
[0021] FIG. 22 : Represents the process or machine readable and executable instructions to find segment pairs when a winding-rule fill mode is specified.
[0022] FIG. 23 : Represents the process or machine readable and executable instructions delineating the general elimination, selection and duplication process.
[0023] FIG. 24 : Modified segment arrangement criteria for the situation of multiple coincident segments.
[0024] FIG. 25 : Polygonal Intersection Processes.
[0025] FIG. 26 : Sorted Segments inside Status Tree. There are three segments in this figure; they are: [AB], [EF] and [CD]. At event point E, the order of the segments in the status tree is: [EF], [CD], [AB], in sequence.
[0026] FIG. 27 : Example of Twin Segment
[0027] FIG. 28 : Example of border information. In this situation, edge border information for object 50 is: edge V1V2 border ID is 10, V2V3 border ID is 30, and V3V1 border ID is 20.
DESCRIPTION
[0028] Printer drivers are traditionally software programs that facilitate communication between an operating system's printing sub-system and an actual hardware device that physically imprints a particular type of substrate. While considerable complexity may exist in the implementation of a printer driver, from the end user's perspective, utilization of such a driver appears simply as part of a seamless process whereby the user selects a “print” command under a given application running within the operating system and then the active document within that application is visually reproduced on the desired printing device. Under some circumstances, printer drivers are used to produce output that is not directly communicated to an actual hardware device. In such cases, the printing device may be referred to as a “virtual” printer in that it may exist to primarily produce electronic files (e.g. image or typesetting files such as jpeg's, bmp's or pdf's). Once created, these files may then be subsequently viewed, transferred or edited by the user for a variety of purposes.
[0029] The method described here specifies a printer driver that can be thought of in either sense (i.e. traditional or virtual) and is unique in that it produces output that effectively reproduces printed documents as embroidered designs. This output when connected to actual hardware such as an embroidery machine allows the machine to appear to the computer operator as simply another printer to which documents may be easily sent. When not connected to hardware, the driver provides the functionality of a virtual printer whereby an embroidery data file may be generated that effectively encompasses the complete specification of an embroidery design. This data file may then be used to view a pictorial representation of embroidery data on a computer screen for editing or further manipulation. Alternatively, this data file may also be manually transferred as input to embroidery equipment where the file presents all data necessary for the equipment to sew out or produce the related embroidery design on material or a provided garment. In another embodiment, this data file can be transferred to a web-service to be embroidered on apparel like T-shirts or hats. The actual transfer may be done using many different protocols like html, low-level sockets, web-service protocols like SOAP, XML-RPC, etc. The printer driver may transfer the low level vector graphics information to the web-service, which then generates embroidery data based on that information. The user is then directed to the web-page through a browser, where he can manipulate the design and select garments on which he wants the design embroidered. After the user confirms the selection the, embroidered garments are delivered to him.
[0030] The embroidery process is substantially different from other more traditional imprinting technologies such as CMYK inkjet processes or screen printing processes. Images are created on fabric using embroidery by placing sequences of stitches at various locations, with various orientations, using a multitude of thread colors. One common type of information stored within embroidery data relates to the relative locations of needle penetration points. This information is often stored using a Cartesian coordinate system (e.g. sequences of x, y values representing the horizontal and vertical location of each needle penetration and subsequently the end point locations for stitches which may be visualized as small line segments). There is already at least one automated system known and disclosed within U.S. Pat. Nos. 6,397,120, 6,804,573, 6,836,695 and 6,947,808 that allows automatic conversion from graphical data (e.g. a scanned image bitmap) into embroidery design data. These patents disclose various aspects of image preparation, shape interpretation, and translation to specific embroidery data primitives based on a variety of factors. The methods described here can be used to preprocess and integrate the raw data supplied by an operating system to its printing subsystem such that it may be re-formed in a way that makes it appropriate or compatible as input to an automatic embroidery data generation system. More specifically, an overview of the systems methods disclosed here is presented in FIG. 1 and employs a low-level printer driver that forwards various types of printing commands to a variety of supporting software. Overall, allowing the user to convert artwork into embroidery designs by the simple act of printing that artwork (e.g., clicking a print button) may offer considerable advantage over other potential methods such as saving the artwork in specific formats or at specific resolutions for later importing by an automatic embroidery generation system. This contrast in use is one of several features that distinguish it from other methods.
[0031] The printer driver that facilitates the disclosed method may be configured as a raster printer that supports bezier curves and other forms of vector and bitmap data (e.g., vector outline representations of fonts, rectangles, ellipses, etc.). Configuration in this way, for example, tells the printer subsystem to send font glyphs instead of bitmaps and bezier curve points instead of normal straight line paths for outline data. This is useful in that it may provide greater accuracy in the image specification when compared to simple, fixed resolution bitmap information. Vector data is the term used to refer to graphical information where a region is specified by mathematically precise shape specifiers such as the edge contours that bound it. Often these boundaries are described as smooth curve or poly-line information. Alternatively, bitmap or raster data refers to more discrete data often in the form of pixels, where a region is specified as a function of what groups of pixels it contains. When the print driver is forced to process bitmap data (e.g., as a result of such data being forwarded from an application program), processing such as that described in previously mentioned prior art should be performed to convert that data to vector outline information. Once vector data is obtained, it is then the responsibility of the printer driver to further process it in order to make it suitable for embroidery design generation.
[0032] When a user prints a particular document (using the print facility supported by the computer's operating system), the printer subsystem calls various routines in a printer driver DLL (dynamic link library) with data to be printed. Example names of such routines may include DrvTextOut, DrvBitBlt, DrvFillPath, and DrvStrokeAndFillPath. These are some of the routines that are standardized as part of the Microsoft Windows operating system printing subsystem. The implementations of these driver routines, as developed in the preferred embodiment described here, convert this vector information into more basic data structures that specify regions such as polygons, rectangles and paths, and then store them as records in a dynamically sized memory block. The path structure may be composed of several sub paths, which are typically either straight line paths or bezier curve points. A path structure may be composed of multiple closed figures formed from several sub paths. The printer dll may also generate additional parts of a path required to close a figure by connecting the first and the last points in a path or sub-path structure.
[0033] The closed or open figures (i.e., shapes) resultant from path structures may be of two types—fill and stroke. A fill shape uses a path structure to delineate its outer most boundaries, whereas a stroke shape uses a path structure to delineate a continuous curve with a predetermined thickness and is typically not actually bounded by the path or sub-path. The printer subsystem specifies a number of attributes to be used to draw such shapes. For example, for fill shapes, the printer subsystem could specify the brush type and color while for stroke shapes it could specify pen color, pen width, end cap and join types. More examples on the type and variety of properties that may be specified for shapes at the printer driver level may be found within printer driver development documentation provided by Microsoft and other operating system vendors. This information is associated with the record of each individual shape. Some of the properties specified by the printer subsystem might not be able to be expressed directly as stitches because of the inherent limitations of embroidery. In such situations, the closest representation may be automatically chosen by default while the user may choose to modify it later-in or completely-after the embroidery generation process. For example, a pattern brush specified for a fill shape would be presented as a solid brush to the system with a default color where this shape will translate to a particular area of embroidery using the specified color as a thread color using a specified fill pattern to approximate the texture or nature of the pattern.
[0034] After the printer subsystem signals an end to the printing of a document (e.g., by calling the function DrvEndDoc) the printer dll transfers raw vector data to the Embroidery Generation Support Program (referred to hereafter as the EG method). Various methods can be used to transfer the data to the EG method such as saving it to a (temporary) file, passing individual messages for each record or utilizing a shared block of memory. In one embodiment, the printer dll passes a predetermined unique message to the EG method indicating that the raw vector data is available in a shared memory block. Prior to passing the message, the printer dll copies the shape records and associated information in a predetermined order from the internal dynamic memory block to the shared memory block.
[0035] The EG method uses a Path Generator (PG) method to generate polygonal boundaries from generic curves/poly-lines and also for stroked paths (e.g., sequences of curves and line segments to be drawn using a GDI pen with particular attributes). Line attributes that are associated with pen types (e.g. pen width, pen color, etc.) may then be used to create a set of polygons that delineate an exterior edge boundary of a stroked path. In some cases, Microsoft Windows® GDI path functions may be called to generate polygons along a stroke path which are visually identical to the original line drawing path after filling occurs during rasterization. However, these functions are typically not sufficient for use here since their precision is often tied to a particular raster resolution.
[0036] The EG method then uses a Metafile Composting (MC) method that sequentially takes shapes (e.g., polygons) where filling modes and color attributes are specified as input and then outputs a set of consistently formed non-overlapping maximally contiguous regions. Input polygons need not necessarily be regular polygons, i.e. polygon vertices may be specified in any order (clockwise or counter-clockwise) and the polygon itself may be self-overlapped. The output is order-specified, i.e. the outer most edge for each region is specified in a counter-clockwise order and any contours indicating holes are specified in a clockwise order. This constraint may not be required, but is often useful in simplifying many subsequent processing tasks including computation of intermediate data such as skeletons (e.g., Voronoi diagram computation), deformation of regions, etc. The EG method then analyzes the composite objects (i.e. the outputted regions) and generates stitch data which can then be fed to an embroidery machine for stitching. The actual methods used to generate stitch data are similar to those already disclosed in the previously mentioned prior art system. A more detailed description of the EG method and some related methods is now provided.
[0037] A stroked path typically has symmetrical properties. Specifically, all end-cap types are symmetrical along the path's center line; all types of joints are symmetrical along the joint angle bisectors. The PG method maintains visual features after adding the stroke outline points and maintains shared points between different connected segment paths consistently. Thus, paths generated by the PG method may be substantially more accurate and resolution independent than ones generated by built-in GDI functions.
[0038] The PG method invokes several methods to compute the end cap and joins based on the attributes specified at the print driver level.
[0039] The Process Round End Cap (PREC) method is used to compute edge boundary vertices at the end point of a stroked path when the selected pen type indicates round end caps as one of its attributes. To maintain the symmetrical property of the round end-caps, the middle point of the arc (Refer to FIG. 14 ) is added first, then boundary edge vertices on left and right sides of the arc are added recursively until a minimum threshold value for smoothness of the arc is meet. Detailed operations of the process are illustrated in FIG. 14 .
[0040] The PG method uses a Process Square End Cap (PSEC) method to compute edge boundary vertices at the end point of a stroked path when the associated pen type indicates squared end caps. Right corner points and left corner points are added first. Example operations are shown in FIG. 15 .
[0041] Process Round Join (PRJ) method is used to compute edge boundary vertices when the selected pen type indicates a round join type. First, the bisector of the two connected path segments is computed (see FIG. 16 ). For the convex side of the path, two vectors are projected from the common join point of the specified related medial path where each vector is projected a distance of one half the pen width and orthogonal to each of the related medial path line segments. The ends of these vectors indicate the end points of the curved boundary to be computed on the outer convex edge side of the path. Then the endpoint of a bisector of these two vectors (again projected a distance of one half the specified pen width) is inserted into the boundaries vertex list. The rest of the vertices are then computed by recursively introducing new bisectors as specified in FIG. 17 and illustrated in FIG. 16 .
[0042] Process Miter Join (PMJ) method is used to compute edge boundary vertices when the selected pen type indicates a miter join type. Here the bisector of the two connected path segments is computed (see FIG. 18 ). Point P y on the concave side (see FIG. 18 ) is computed on the bisector based on the path radiation R (i.e., based on one half the specified pen width). Point P x on the convex side is computed based on the miter limit length. If the limit is not set with the associated pen property, then P x is computed using the extensions of two side boundaries (see FIG. 18 ).
[0043] Process Bevel Join (PBJ) method is used to compute edge boundary vertices when the selected pen type indicates a bevel join type. The bisector of the two connected path segments is computed (see FIG. 20 ). Point P y is computed similar to the methods used within the PMJ method. Point P x is calculated on the bisector based on the pen width. Line P m P n is calculated perpendicular to the bisector line and Point P m and P n are the intersections with two side boundaries which are parallel to the related path segment. A final boundary shape is illustrated in FIG. 20 . The MC method (also referred to as the composting method) receives the printing records and translates them into a set of closed contours that delineate the contiguous regions equivalent to those that would result from rendering (e.g., printing) the original file on an arbitrarily sized display. These printing records may be thought of as analogous to a computer graphics metafile (CGM) specification in that they are an ordered list of commands that may be used to reproduce a visual picture or image. The ISO specification is a four-part standard defining a file format for the application-independent capture, storage and transfer of graphical pictures. Compositing computer graphics metafiles (CGM) is the process of applying various Boolean operators among potentially overlapped primitive shapes specified within a file designed to create a visual image. On a raster-type device such as a computer's CRT display or inkjet printer when a subset of vector commands overlaps or otherwise intersects with previously drawn or executed commands, the pixels within the overlapped areas are simply reset to the color specified by the more recent vector commands. Thus, potential redundancies within a metafile (i.e. situations where multiple commands repeatedly “paint” within the same area) are resolved through a process of rasterization in which more recent commands always take precedence over those that were previously executed. However, for many applications, the loss of flexibility that results from rasterization (e.g., loss of detailed outline information) makes it less suitable for developing a usable composite representation of a metafile's vector commands. Specifically, it may be desirable to eliminate redundancies within vector outlines by actually modifying the underlying outlines directly so that painting within any given area never occurs more than once (i.e., no overlapping occurs). This may provide such benefits as greater compression of picture information. Also, the result may be used for other applications such as computerized embroidery imprinting in which it is often undesirable to repeatedly sew or place stitches within a single area of fabric. Note that compositing is not a strict requirement of the print driver method disclosed here. Without compositing, embroidery data may still be generated separately for each of the individual underlying print records. However, there are many situations where such an approach yields embroidery data that may not be practical for actual production on embroidery equipment (e.g., sewing repeatedly over the same area or triggering excessive thread trims or redundant needle movements even when sewing a single same-colored contiguous area). Hence, compositing is included here as a desirable step to achieve a more consistent usable result for embroidery data generation.
[0044] The compositing method is comprised of four general operations: 1) Finding intersections among the edges of regions (e.g., polygonal boundary intersection). 2) Finding segment fill pairs. 3) Arranging segments and 4) Re-establishing segment lists and the resultant associated output regions.
[0045] The MC method first executes a Find Polygonal Object Boundary Intersection (FPOBI) method which permits the reliable and predictable detection of intersecting polygonal edges. This method makes use of the line sweep technique and algebraic predicates, but has also been further extended to handle additional requirements and degeneracies precipitated by the compositing operations. Some of the degeneracies have been tackled individually in previous work, but still do not facilitate a comprehensive and robust solution to the specific issues discussed here. Previous work includes a method for testing two simple polygonal objects using enveloping triangulations. Another method includes heuristics for detecting whether two polygons intersect using a grid-based method, a method that works optimally when the polygon edges are distributed in a uniform manner (which would not be typical of input cases dealt with here). This method offers some distinct benefits when compared to basic line-segment intersection algorithms. Numerous methods have been presented that solve the problem of finding intersections among line-segments. Unfortunately, it has also been shown that several prior art methods largely rely upon models of exact computation that may become computationally impractical for engineering solutions implemented using hardware which supports only IEEE floating point representations. One previous method proposed the plane-sweep algorithm for finding intersections among line-segments which solves the problem in time O((n+k)logn). This method also has been reported to be quite sensitive to numerical errors and, hence, must also rely upon a model of exact computation to produce correct results. Thus, one proposed solution relies upon algebraic predicates to alleviate many of the numerical issues prevalent in the line sweep algorithm and argue that this algorithm may be superior to others since it requires a comparatively lower degree predicate than that which would be required by other algorithms.
[0046] The MC method is different from Polygon Clipping or other operators that compute Boolean operations among specified regions. Algorithms that facilitate a Boolean set of operations that may be used to unite, subtract, or intersect solid objects with each other is a common component of many solid modeling systems. Polygon Boolean operations are derived from polygon clipping algorithms. Many polygon clipping algorithms have significant limitations, (e.g., some algorithms are limited to convex polygons, some algorithms require that the clip polygon be rectangular; some algorithms do not allow polygon self-intersections). Commonly encountered CGMs (computer graphics metafiles) cannot be easily modified to adhere to such restrictions (including those produced by the print driver method described here). Even the simple case of detecting if one polygon lies within the boundaries of another polygon becomes less obvious when one of the input polygons intersects with itself (a degeneracy that is common within metafile records). Vatti's algorithm and Greiner and Hormann's algorithm can be used for testing polygon self-overlaps by counting the winding number. However, overlaps that result in zero-area portions of the polygon would still not be eliminated as is inherently required by the problem presented here. Many efficient polygon clipping algorithms have been published in the literature, however, a direct substitution of such algorithms to handle the task of metafile compositing is generally infeasible. Hence, the metafile compositing method described here is largely focused on developing Boolean operators suitable for input sets with large numbers of polygonal objects containing varied degeneracies, to provide a fast, robust, comprehensive and practical solution.
[0047] The MC method is related to the problem of map overlay studied within computational geometry. Solutions to this problem involve detecting and subsequently processing the intersections and unions of polygonal objects that are placed within a two-dimensional space (e.g., outlines of highways, rivers, lakes, etc.). Thus, if each vector command within a graphics metafile is considered as a layer in a geometric map, the techniques used in map overlay may be applied to the problem of metafile compositing. The input of a map overlay operation consists of two or more topologically structured layers and the output is a new layer in which the new areas in that layer are given attributes that are based on the input layers. The procedures are similar in that an overlay operation takes two or more data layers as input and results in an output layer, just as a metafile contains many records and the output may be considered as a single layer. However, there are several differences. First, the ordering of input records or layers within metafile compositing is important; if the input order is changed, the output may be different. Thus, when applying map overlay algorithms to metafile compositing, the time sequential features of the metafile records are taken into account. Second, in map overlay algorithms, different layers have different attributes. However, in metafile compositing, different records may have identical attributes, for example, the same color. Therefore, in certain situations, merging operations may be performed for same attribute layers when constructing the output. Finally, in map overlay one region may receive attributes from many layers; in compositing CGM, any given region typically only receives attributes from a single record.
[0048] CGM command records (e.g., the printing records) may contain degenerate polygonal objects, such as zero-length segments, zero-area polygonal objects, grazing and self-overlapping. Many records may also be drawn in the same region redundantly. The vertex list order is not specified. The closed area is the brush painting area, thus, some records may be drawn in clockwise order while others are drawn in counter-clockwise order. CGM records may be attribute filled using different modes (e.g., alternate edge/scanline versus winding rule fills). Filling modes must be considered to generate correct results.
[0049] CGM input records paint arbitrary, potentially overlapping regions sequentially where the ordering of records combined with their fill attributes is important. For example, for records with different fill colors, the newly drawn record hides the previously drawn record if they are overlapping or partially overlapping. Based on this property, the Boolean operation of “NOT” is performed if two input records have different colors and the newly drawn record has a higher drawing priority (e.g., is present later within the list of input records).
[0050] Overlapping records that have identical fill attributes (e.g., same color) in certain instances may be processed to eliminate the extra overlapping portion since this does not affect the visual appearance of the metafile. Thus, in these instances, a merging or logical “OR” operation may be performed.
[0051] Other prior art methods such as graph exploration for overlaying planar subdivisions do not address issues of numerical accuracy or degeneracy within input data sets. Unfortunately, without consideration of such issues, a practical and robust solution is difficult to obtain. Examples of such degeneracies include zero-length segments, zero-area polygonal objects, grazing, self-overlapping, and multiple congruent polygonal region boundaries. The MC method disclosed here has been shown to work for very large numbers of polygons where such input data may contain large numbers of degeneracies of the types mentioned previously. The method considers not only the original geometric coordinates, but also the original drawing sequence and filling modes. Output display is visually identical to the input, the difference being that all overlap of dissimilar attributes and all adjacency of like attributes are removed. The method's performance within the presence of degeneracies and large input sets is one feature which distinguishes it from previously published related work.
[0052] In order to disclose the details of the MC method some basic definitions are first provided. The terms defined may relate to terminology used here as well as in prior art that may discuss other methods that employ sweep-line approaches to solve problems within computational geometry. First, an “event point” is defined as a point in the plane at which the sweep algorithm evaluates and processes current input and data structures. Event points are ordered according to their y and then x coordinate values. In the MC method event points are the endpoints of line segments or computed intersection points between two or more line segments where these line segments represent the outer boundaries of polygonal regions. An “edge” refers to the connection between two event points (i.e., its end points). Its domain is a finite, non-self-intersecting open curve. An edge has two end-points and its length is greater than zero. E[A i A j ] denotes an edge that has A i and A j as its end-points. A “segment” is similar to an edge in that it is also a closed line. It stores an upper-end-point and a lower-end-point. Let S[A i A j ] denote a segment that has A i and A j as its end-points. Let A i < y A j denote that point A i is smaller than A j along the y-axis. Similarly, A i < x A j denotes that point A i is smaller than A j along the x-axis. If A i < y A j , or A i = y A j and A i < x A j , in the printer device coordinate scheme, A i is the upper-end-point and A j is the lower-end-point. A “segment pair” consists of two segments which intersect the sweep line and lie on opposite edges of a given region. It indicates an area between two segments that is part of a GDI fill area for a particular metafile record or polygonal object. A “segment pool” contains segments having a particular attribute (e.g., color) as inherited from the original input data (i.e., the attribute of its related polygonal object). Multiple segment pools are maintained within the MC method where there is one and only one pool for every attribute present within the input data. A segment pool invariant is that while segments may share end points, no segment within a given pool may be coincident with any other segment within that pool. Note: segments may be added to a particular attributed pool, even though originally they may not have exhibited that attribute. However, once added to the pool they then lose their previous attribute and inherit that of the pool. A half opened edge, which only includes the origin point, is called a “half-edge.” E[V i V j ] denotes a Half-edge that has vertex V i as its origin and vertex V j as its destination. If one walks along a main-half-edge, the face of an associated region lies to the left. For a twin-half-edge, the face of an associated region lies to the right. A closed polygon P is described by the ordered set of its vertices V 0 , V 1 , V 2 , . . . , V n , V 0 =V n+1 , where n>=3. It contains all main and twin half-edges consecutively connecting the vertices V i , i.e. the main half-edges are E[V 0 V 1 ), E[V 1 V 2 ), . . . E[V n−1 V n ), E[V n V n+1 )=E[V n V 0 ) and the twin half-edges are E[V n V n−1 ), E[V n−1 V n−2 ), . . . E[V 1 V 0 ), E[V 0 V −1 )=E[V 0 V n ). A “polygonal object” O is described by a set of polygons P 0 , P 1 , P 2 , . . . , P n where P 0 is the outer polygon, which is specified in a counter-clockwise order and P 1 , P 2 , . . . , P n are inside P 0 and are specified in clockwise order. In terms of metafile compositing, a polygonal object is a distinct, named set of attributes that represents a contiguous graphic region. The attributes hold data describing the graphic, such as color, drawing sequence, etc.
[0053] Let S be the set of segments of all polygonal objects in the plane. Let Q be the sorted vertices of segments (sorted by y and then x values) in the plane; these points will be evaluated as “event points” within the algorithm. Let r be the sorted list that stores those segments that intersect with a sweep line. P is the pointer that indicates the current event point being evaluated within Q. Let U(P) be the set of segments which have P as their upper endpoint. Let L(P) be the subset of τ which has P as its lower endpoint. Let C(P) be the subset of τ which has P as its interior point, meaning P is on that segment but is not the endpoint. S l (P) and S r (P) denote, respectively, the left and right neighbor segments of P in τ. Let A be the collection of segments in τ (the status tree). Let M l (A) be the left-most segment of A and M r (A) be the right most segment of A. Note, lines of pseudo-code shown in FIG. 25 represent an overview of the method used to find boundary intersections. Lines printed in bold, represent modifications over that which was presented in previous methods.
[0054] There are many differences between the sweep-line methods disclosed here when compared to other commonly-known sweep line algorithms. Other published algorithms do not address details on the treatment of special cases and degeneracies or, when present, such details are only partially explained. For example, some methods assume any two segments or curves will intersect at most at a single point which may not be true. Here, an attempt is made to avoid such assumptions and fully consider the details of degenaricies to allow a comprehensive engineering solution.
[0055] A predicate arithmetic model is used to determine if two segments intersect in line 1 of FindNewEvent (see FIG. 25 ), an approximation of this intersection point is also computed and stored. Using algebraic predicates, the determination of whether two segments intersect is guaranteed to be correct as long as input data coordinates do not exceed what may be represented by 24-bit integers. In this specific application, input coordinates of metafile records are stored as 16-bit integers. However, the construction and storage of actual resultant intersection points does not have the same guarantee of accuracy and inevitably some rounding of results may occur potentially shifting the locations of intersection points from their true positions. Such rounding may potentially impact the final output in that certain polygonal vertices may be inaccurate to the extent that IEEE floating point arithmetic results yield slightly different values for their positions. However, particular care is taken such that this rounding will not prevent the method from constructing its output. This is primarily achieved by assuring some degree of consistency in the rounding that will occur and allowing the algorithm to effectively ignore such rounding. For example, when two segments intersect, where one or both of those segments emanate from previously computed intersections at one or more of their end points, the original end points of the related segment (rather than the “intersection end points”) are used for both detection and construction of an intersection point.
[0056] It has been suggested that the order of the segments in the status-tree corresponds to the order in which they are intersected by the sweep line just below the related event point. However, this appears to be insufficient in some cases (see example in FIG. 26 ). According this method, the key value for [AB] cannot be found, because an intersection point below the sweep line is not present. Here, in such cases, a super-key may be used to sort the segments in the status-tree: the first attribute of the super-key is the x-coordinate of the point intersected by the sweep line and the segment at the event point; the second attribute of the super-key is the segment's slope.
[0057] An intersection is a point where lines intersect by definition. This definition is used by most previously published work. However, for polygonal object intersection, this is not always applicable. If two segments from the same polygonal object intersect at both end points, this intersection may not be considered as an intersection of the object. Only intersections of segments that are from different polygonal objects should be reported. In lines 6 , 17 , 19 and 22 of HandleEventPoint and line 5 of FindNewEvent, segment classification is performed before reporting intersections. Typical CGM records cannot be assumed to be simple polygons. Rather, they tend to exhibit all types of deficiencies, such as self-intersections and grazing contact between multiple polygons (e.g. holes) even within a single polygonal object. The above algorithm can be modified slightly for detecting and finding self-overlapping intersections.
[0058] These compositing methods presented here are intended to eliminate redundant segments and re-establish link-listed polygonal objects. This is accomplished primarily through the creation and use of segment pools where segments having a particular shared attribute are organized together in a single pool. As the sweep-line process progresses, each segment (through its association with a segment pair) may either be discarded or moved to one or two segment pools. Another invariant of the sweep-line process regarding segment pools is that while segments may share end points, no segment within a given pool may be coincident with any other segment within that pool and no two segments will cross each other. Preservation of this invariant is largely addressed within the Overlapped Segments Selection Criteria algorithm summarized in FIG. 24 . For example, lines 2 and 3 of the algorithm imply that S m or S n may be selected into different segment pools with different attributes or neither may be selected. Similarly, the duplication rule cannot generate coincident or duplicated segments to an individual segment pool. After this sweep completes, a segment pool has the property that traversing segments within the pool (via another sweep pattern) generates one or more cycles (i.e., closed contours containing no self-crossings).
[0059] Segment pairs (see definitions disclosed earlier in this specification) are found at each event-point (event-points include original segment end points and segment intersections) based on CGM filling rules. These pairs are intended to indicate areas between each pair that comprise filled portions of related polygonal objects. Finding segment pairs is a pre-processing step for segment arrangement (e.g. selection and duplication to segment pools) that effectively eliminates unneeded or redundant segments of a polygon (i.e. segments that have been occluded due to filling rules or self overlap). Similar to the algorithm used for finding intersections, it is assumed that a scan-line goes from top to bottom, halting at each event point. Segment pairs are easily located if the original related print or metafile record uses an alternate edge fill mode. More specifically, it can be done by just selecting the odd and even segments on the scan-line and pairing them up respectively. If a record and its related polygonal specification use a winding-rule fill mode, the original drawing direction must be stored and the fill depth must also be tracked. FIG. 22 depicts the algorithm used here for finding segment pairs when a winding-rule fill mode is specified.
[0060] Segment pairs may change at each event point. For example, at event point A in FIG. 6 ( a ), segment pairs are {AB left , CD right } and {EF left , PQ right }. While at event point D in FIG. 6 ( b ), segment pairs are {AB left , PQ right } (i.e. the pair segment AB changes at different event points due to the winding rule fill mode).
[0061] The Segment Arrangement (SA) method described here determines at each “event point” whether an input segment should be eliminated, selected or duplicated based on metafile drawing and filling rules. Elimination means a segment that is drawn underneath other primitives will not be put into any segment pool. Selection means an original segment will be moved into a segment pool with similar attributes. Duplication means an original segment is copied into a segment pool with different attributes (where the copied segment then assumes the attributes of the pool into which it was copied). These three rules, shown in detail below constitute guidelines for the final arrangement algorithms. In general, segment selection and duplication are based on two factors: attribute values and age of the related polygonal object. A polygonal object is said to be younger if it appeared sequentially later within the list of metafile records. If a polygonal object is created earlier, it is considered older. For example, for differently colored objects, segments that are from younger objects may be selected and duplicated for those objects that are underneath or overlapped by them. These can be observed, in FIG. 7 , where object C is specified last and its segments will be selected and copied for object B.
[0062] Rules for Segment Elimination, Selection and Duplication are described as follows: Let S face (i) denote the face that is associated with segment S belonging to polygonal object i, where polygonal objects are ordered by their age. Note if j<i this indicates that the i th object is younger than the j th object. {SL i , SR i } denotes a segment pair where SL i denotes the left segment (of the pair) of the i th polygonal object at a specific event point and SR i denotes the right segment. According to the CGM filling method, the following selection and duplication rules are defined in order to separate the segments according to their attributes:
[0063] The “Elimination Rule” is defined as follows: if S j is between any segment pair {SL i ,SR i }, S j will be hidden in either of the following two cases: Case 1: j<i or Case 2: Attributes(S face (i))=Attributes(S face (j)). If S j is hidden, it will not be placed or duplicated into a segment pool.
[0064] The “Selection Rule” is defined as follows: S j will be moved to a segment pool in either of the following two cases: Case 1: S j is not inside or between any segment pair {SL i , SR i }, or Case 2: Of all segment pairs that S j lies between, let {SL i ,SR i } denote the youngest pair. If j>i and Attributes(S face (i))≠Attributes(S face (j)) S j will be moved.
[0065] The “Duplication Rule” is defined as follows: Of all segment pairs that Sj lies between, let {SL i ,SR i } denote the youngest pair. If j>i and Attributes(Sface(i))≠Attributes(Sface(j)), let S j ′ be the duplication of S j where Attributes(S′face(i)) are assigned Attributes(Sface(i)) and S j ′ is placed into the associated segment pool.
[0066] To further the operations of segment arrangement, an object stack is used to store active polygonal objects, where an object is considered to be active while scan lines continue to intersect with it. When the scan line hits the left segment of a segment pair, the object that is associated with that left segment is pushed on to the stack. Similarly, when the scan ray hits the right segment of a segment pair, the object associated with the right segment is popped off the stack.
[0067] Assuming a ray comes from infinity on the left and moves toward infinity on the right. Let S k denote a segment that intersects with the ray, where k=0, 1, . . . , n. At each event point, all segments are sorted from left to right (using the same method used previously for finding intersections) and stored in a queue. Therefore, S O is the left most segment, and S n is the right most segment.
[0068] It is not safe to assume that S O through S n do not overlap. It may be commonly found that many segments are coincident (i.e., share the same two end points). Such cases require additional bookkeeping and are discussed next. FIG. 23 delineates the general elimination, selection and duplication algorithm.
[0069] Lines 1 and 4 in FIG. 23 must be modified when several segments are coincident, because otherwise any one of these coincident segments could be arbitrarily or unpredictably hit first by the scan ray. In such cases, coincident segments are reordered and grouped into a “right group” and a “left group” where each group is then sorted. Specifically, Let S be the coincident segments which intersect with the scan ray. Let S left be the segments in S that belong to the left group (i.e. segments that are marked as the left segment within their corresponding segment pairs) and similarly, let S right be the remaining segments in S that are marked as right segments. S left and S right are then sorted by their related polygonal object's age (ascending order, youngest first). Let S m and S n denote the youngest segments within S left and S right respectively. Ø denotes an empty segment set. Thus, the modified segment arrangement criteria for the situation of multiple coincident segments are refined in FIG. 24 .
[0070] Note that in this special case, “Not Selected” implies “elimination”, therefore, the elimination criterion is omitted altogether. Additionally, according to these new coincident segment selection and duplication rules, S right will be processed first then S left . In the case of duplication, if there is at least one left segment and one right segment overlapping, even if they are not a segment pair, they will not be used for duplication. For selection, only the youngest left segment and youngest right segment will be selected. An example is illustrated in FIG. 8 . Let SR 2 SL 3 SR 4 SR 6 SL 7 SR 8 SL 8 SR 9 in FIG. 8 ( a ) be overlapping segments where their order represents their intersection sequence with the scan ray. In this case, only SR 9 and SL 8 will be selected if the related face attributes of SR 9 and SL 8 are different. However, if the attributes of SR 9 and SL 8 are identical, neither SR 9 nor SL 8 will be selected or copied.
[0071] After segment pools are populated, a Generate Composite Objects (GCO) method must execute to generate new resultant objects that represent the final composite shapes within the image. This method effectively builds new objects using the segments contained within each pool. As a segment pool may contain segments inherited from initially unrelated or differently attributed polygonal objects, there is no inherent linking or sequencing among them (other than obviously being placed within the same pool). Thus, a final step is to reconstruct a consistent and uniform traversal of such segments to indicate the boundaries of the one or more polygonal objects contained in a pool (i.e. so objects are comprised of an outer edge contour specified in counter clockwise vertex order and zero or more inner edge contours, indicating holes, specified in clockwise order). This is accomplished most efficiently by performing one final sweep-line process (using the rules below) on each pool to construct the appropriate contours as just described.
[0072] Rule 1: Segment traversal in each segment pool starts from an unvisited odd-segment at each event point where the even/odd attribute of a segment is determined as when alternate edge filling rules are applied. Each segment can only be visited once and all segments in the pool must be visited. For example, the arrowed lines in FIG. 10 indicate the starting segments at event points V 1 , P 1 and M 1 .
[0073] Rule 2: If there is an unvisited even numbered segment on the left of an odd numbered segment emanating from the same event point at the start of a traversal, the traversal path forms a hole. Oppositely, if the segment on the left of an odd numbered segment is visited, the traversal path forms the outer edge of a polygonal object (see example in FIG. 10 ).
[0074] Rule 3: At each vertex during traversal, if there are two or more edges unvisited, the leftmost edge is chosen if the traversal is along an outside boundary whereas the rightmost edge is chosen if it is a hole (as previously determined using rules 1 & 2). FIG. 11 shows how this rule is applied.
[0075] In addition to pool attributes (i.e. pool ID, color etc.), each segment is also associated with its twin segment which is stored in a different pool (analogous to the two half edges that comprise any edge). This association allows border information to be constructed for each object when a traversal is performed in each segment pool. More specifically, the twin segment's attributes are checked during the traversal. If the twin segment's attribute information is changed (e.g. the adjacent object with which this object borders has changed), the starting point of the edge is flagged as an “Adjacent Object Transfer Point.” And the border ID is set to is twin segment ID (where ID's are uniquely assigned to every resultant object generated). This border information basically specifies exactly where objects are touching or adjacent to other objects and can be quite useful when generating embroidery data. For example, to ensure solid registration (with no visible gap between adjacent objects) it may be useful to modify the embroidery generated for one object (appearing earlier in a sewing sequence) such that it extends or partially overlaps underneath another object to be sewn later in a sewing sequence only where the two objects are adjacent to one another. This will ensure that even if some visible shrinkage is present in the embroidered representation (i.e. due to stitch tension, etc.), the two objects will still be visibly adjacent to each other with no apparent gap. This auto-overlap type feature is difficult to facilitate if border information is not generated for each object.
[0076] After MC method is executed, embroidery primitive data generation can proceed by translating objects into specific embroidery stitching pattern. One embodiment of this method executes as disclosed in U.S. Pat. Nos. 6,397,120, 6,804,573, 6,836,695 and 6,947,808 where embroidery primitive control points are generated based on the geometric properties of the related shapes. Common border information (as mentioned above and referred to within the patents) further guides this process. After control points are generated, the actual x, y coordinates of stitch end points are produced by a stitch generation method. These end-points may then be easily reformed into any one of dozens of different proprietary machine file formats for viewing in editing programs or direct download for production on actual embroidery sewing equipment. | An example printer driver system and method disclosed herein includes determining a set of line segments corresponding to received image information, determining a first polygon from a first subset of the set of line segments, determining a second polygon from a second subset of the set of line segments, determining that a first line segment in the first subset and a second line segment in the second subset are collinear, removing the first line segment from the set of line segments, subtracting the first line segment from the second line segment to form a third line segment, replacing the second line segment in the set of line segments with the third line segment, determining a path corresponding to the set of line segments, determining a set of coordinates corresponding to the path, and instructing an embroidery machine to stitch the path in a substrate using the set of coordinates. | 3 |
This invention was made in the performance of work under a contract with the United States Department of the Air Force, and the United States Government has certain rights therein.
BACKGROUND OF THE INVENTION
Linear electrooptic switching and second-harmonic generation are processes that require materials possessing second-order nonlinear susceptibilities. That is, materials for which the polarization of the material has a term that responds to the square of the electric field. For optical switching, an applied DC or low frequency field can then modulate the material response to an optical field leading to optical switching. In second harmonic generation, the polarization at the second harmonic is proportional to the square of the applied optical field at the fundamental (first harmonic) frequency. It has long been known that for materials with inversion symmetry, i.e. materials that cannot in some way distinguish between up and down, the second-order susceptibility must vanish. Even though materials such as silica (SiO 2 ) may have a crystal structure without inversion symmetry, the random orientations found in amorphous or glassy forms of the material ensures a macroscopic inversion symmetry.
There are myriad applications for materials with second-order nonlinearities, particularly in integrated optics and optoelectronics. For example, LiNbO 3 waveguide switches for optical crossbar applications are commercially available. As optoelectronics matures with widespread applications in optical information processing, there is a growing need for the development of improved high-speed waveguide switches, directional couplers, and other signal routing devices. Compatibility with semiconductor optoelectronics will lead to a major simplification and growth of the market for these devices. LiNbO 3 switches are based on a bulk crystal technology, which is not directly compatible with semiconductors such as Si and GaAs or other III-V compounds that are widely used for the fabrication of laser sources and detectors in optoelectronics.
There is also increasing interest in harmonic generation in waveguides, particularly to convert the infrared output of III-V semiconductor lasers to the visible. Here again compatibility with traditional semiconductor materials is a major issue. Present techniques rely principally on external harmonic generation, usually involving resonant cavity effects, with relatively complex optical and mechanical arrangements.
Fused silica is ubiquitous in modern technology. Its extremely low linear optical losses have enabled the fiber optics industry. SiO 2 also plays a dominant role in microelectronics technology where the unique properties of the Si-SiO 2 interface are largely responsible for the behavior of metal-oxide semiconductor (MOS) devices underlying advances in computer hardware.
Unlike its related quartz crystalline phase, fused silica is amorphous with a macroscopic inversion symmetry that forbids second-order nonlinear processes. Thus, the discovery by U. Osterberg and W. Margulis, Opt. Lett. 11, 516 (1986) of efficient second harmonic generation (SHG) in a variety of Si-Ge glass fibers upon "training" with optical fields has generated considerable interest in the physics and applications of this unexpected phenomenon. R. H. Stolen and H. W. K. Tom, Opt. Lett. 12, 587 (1987) showed that the nonlinearity could be induced in a much shorter time by seeding the fiber simultaneously with both the fundamental optical (1.06 μm) and the second harmonic (532 nm) beams and proposed a mechanism based on static electric-field-induced nonlinearities. The field arises from charge separation and trapping in the fiber material. Recently, D. Z. Anderson, V. Mizrahi and J. E. Sipe, Opt. Lett. 16, 796 (1991) have proposed a photovoltaic effect based on interference between the fundamental and harmonic fields that phenomenologically accounts for the observed strength of this field, which (see A. Kamal, M. L. Stock, A. Szpak, C. H. Thomas, D. A. Weinberger, M. Frankel, J. Nees, K. Ozaki, and J. Valdmanis, in Digest of Optical Society of America Annual Meeting (Optical Society of America, Washington, D.C., (1990) paper PD25) is about four orders of magnitude larger than the field expected from optical rectification. This field interacts with the material third-order nonlinearity, χ.sup.(3), to provide an effective χ.sup.(2) =χ.sup.(3) E dc . Similar field-induced nonlinearities have been observed in a variety of material systems, e.g. paraelectric PLZT by A. Mukherjee, S. R. J. Brueck and A. Y. Wu, Opt. Commun. 76, 220 (1990). An alternative explanation is an orientation of nonlinear moieties in the glass, although no microscopic indentification of these moieties or of the magnitude of their nonlinearities has been put forward.
SUMMARY OF THE INVENTION
According to the invention, a permanent second-order nonlinearity χ.sup.(2) in the near surface region of bulk fused SiO 2 is induced by a temperature/static electric-field poling process. The induced X.sup.(2) s achieved are three to four orders of magnitude larger than those found in the fiber experiments (as mentioned in the above-cited Osterberg article) and approach that of traditional nonlinear optical materials such as LiNbO 3 .
BRIEF DESCRIPTION OF THE DRAWINGS
Reference is now made to the drawings in which
FIG. 1. is a schematic diagram of an arrangement in accordance with the invention for producing a permanent second-order nonlinearity χ.sup.(2) in bulk fused SiO 2 ;
FIG. 2 is a graph of SHG signal at 533 nm from a poled optosil™ sample vs. the angle of incidence for a TM polarized fundamental beam at 1.06 μm;
FIG. 3 is a graph of SHG signal vs. the poling voltage for a fixed temperature and poling time. The signal was obtained on a single sample with successive polings at higher poling voltages; and
FIG. 4 is a graph of SHG signal as material is successively etched away for two samples with identical poling voltages (5 kV) and temperatures (280° C.) but different poling times.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the invention, referring to FIG. 1, χ.sup.(2) nonlinearity is produced in a sample 11 of fused SiO 2 (silica) 1-mm thick by first heating it from source 13 to temperature in the range of about 200° C. to about 325° C. in a laboratory ambient while applying from source 14 a dc bias of from about 3 kV to about 4 kV to electrodes 15 and 17 on opposite sides of the SiO 2 sample. After 10 to 15 minutes of poling, the heater is turned off and the sample cooled to room temperature while maintaining the dc field. The electrodes 15 and 17 which may be stainless steel and/or Si may be in intimate or close contact with the sample 11. Other electrode materials such as evaporated Au or Ag may be used. Once cooled, the electric field is removed and a stable χ.sup.(2) nonlinearity is observed. Samples maintained at room temperature without special precautions for several months maintain the nonlinearity without significant degradation. Application of heat alone, above about 200° C. for a duration that varies with the temperature, removes the nonlinearity. While the voltage to be used is not proportional to the sample thickness, nonlinearities are obtained when 180-μm thick samples are placed atop a 1-mm thick sample and the above-mentioned voltage of about 5 kV is applied across both samples.
During the poling, the current decays in about two to three minutes. The maximum current varies from 0.8 μA to 5 μA; no correlation has been established as yet between this current and the sample properties. However, the integrated current is roughly constant for all samples.
The second-order nonlinearity of these poled samples may be observed under irradiation with 10-ns laser pulses at the fundamental wavelength of 1.06 μm from an unfocussed (1-mm spot size) Q-Switched Nd-YAG laser beam operating at 10 Hz at an intensity of 10 MW/cm 2 . Under these conditions, a strong second harmonic wave is produced. For example, such wave as recorded with a photomultiplier tube has an observed signal-to-noise ratio of approximately 104:1.
Since the poling breaks the symmetry along the electric field direction, the effective c-axis of the nonlinearity is along this direction, and a second harmonic (SH) polarization may be induced only along this direction. Orienting the z-axis (i.e., the "3" direction) of a three-dimensional Cartesian coordinate system along the c-axis of the poled sample, the induced SH polarization can be written as:
ρ2ω.sub.z =2ε.sub.o {χ.sup.(2).sub.31 (E.sub.x.sup.2 +E.sub.y.sup.2)+χ.sup.(2).sub.33 E.sub.z.sup.2 } (1)
where ε o is the dielectric constant, E x , E y , and E z are the electric fields in the direction of the x,y, and z axes, and χ.sup.(2) 31 and χ.sup.(2) 33 are the appropriate tensor elements of the second-order nonlinear susceptibility. Defining the plane containing the propagation vector of the pump beam and the surface normal as the horizontal plane, and, and propagating the p-polarized input beam at an angle θ with respect to the c-axis, the induced SH polarization ρ can be written as:
ρ=2ε.sub.o E.sub.1.sup.2 (χ.sup.(2).sub.31 cos .sup.2 θ sin θ+χ.sup.(2).sub.33 sin .sup.3 θ)(2)
The observed power of the SHG wave is P 2 ω ∝|ρ| 2 cos 2 θ where the cos 2 θ factor comes from the increase of the beam cross-sectional area (and decrease in intensity) with increasing angle. There is no SHG wave for normal incidence irradiation. A theoretical fit to the angular dependence of the SHG power shows that the SHG wave should maximize at an incident angle of approximately 60°. As shown in FIG. 2, a large second harmonic wave was measured at 60° angle between the propagation vector of the incident light and the surface normal.
Scanning the laser spot transversely across the sample yields a smooth nonlinearity profile over the area covered by the 1-cm 2 electrode used for poling. As shown in FIG. 3, the SHG wave increases as a ˜3.2-3.5 power law with the applied voltage for fixed poling temperatures and times. Heating to about 200° C. erases the nonlinearity. The nonlinearity may be recycled through a number of cycles of depoling (by application of heat alone) and repoling (by application of heat and electric field) without degradation of the wave. CW irradiation at a power level of 100 mW/cm 2 at 257 nm for over an hour does not effect the nonlinearity. This is in contrast to the fiber results, where uv irradiation does erase the nonlinearity as shown by I. C. S. Carvalho, P. M. P. Gouvea, W. Margulia, J. P. vod der Weid, and B. Lesche, Proc. of the 1991 Conference on Lasers and Electrooptics (Optical Society of America, Washington, D.C., 1991, paper JTuA3)
Regarding SHG waves at other wavelengths, 8-10 ns pulses of 0.1 mJ energy at the wavelengths of 532 nm and 750 nm are obtained from a frequency doubled Q-switched YAG laser and a pulsed dye laser pumped by the frequency doubled YAG laser, repectively. These pulses are used to generate SHG waves at 266 nm and at 375 nm, respectively.
No fringes occur as the angle of incidence is varied at any wavelength. This indicates that the nonlinear layer thickness is less than or comparable to the coherence length, which is 3 μm at 532 nm as shown by I. H. Malitson, J. Opt. Soc. Amer. 55, 1205 (1965). The absence of fringes also indicates that the nonlinearity is generated only on one side of the sample. From the periodicity of the interference fringes observed from two adjacent samples, it is seen that the nonlinearity is always on the positive-biased side of the sample. The nonlinearity moves from one side to the other under repoling with reversed polarity.
The depth profile of the nonlinearity is determined by differential chemical etching using 49% HF acid solution. FIG. 4. shows the variation of the SHG as a function of the layer depth for samples poled for a duration of 15 minutes and for a duration of two hours. Etch depths are determined by surface profilometer scans at each etch step. There is significant roughening of the sample surface by the etching. An index matching fluid is used to insure an optically smooth surface for comparability of the results. While the initial SHG signal measured using 1.06-μm pulses is approximately the same for both samples, the increase of the layer thickness on longer poling time is significant. For the nominal 15 min. poling, the characteristic depth of layer thickness is ≦4 μm.
The χ.sup.(2) coefficient can be measured by comparing the signal from poled SiO 2 samples with the SHG signal generated in crystal quartz (1-mm thick) and LiNbO 3 (76-μm thick) reference samples at four different wavelengths. The maximum SHG signal in these reference samples, generated over a full coherence length (much shorter than these sample lengths) is given by
P.sup.2ω.sub.max ∝|ρ|.sup.2 cos .sup.2 θL.sub.c.sup.2 /π.sup.2 (3)
where L c (=π/Δk) is the coherence length for the SHG at the corresponding wavelength. For an exponentially decaying nonlinearity, as found for the poled fused silica samples, the SHG power is
P2ω(L)∝|ρ(0)|.sup.2 {(e.sup.-2αL +1-2e.sup.-2αL cos ΔkL)/(Δk.sup.2 +α.sup.2)}(4)
where α -1 is the characteristic length of the nonlinearity. For an exponentially decaying nonlinearity, the limit of L→∞ can be used and the SHG power becomes proportional to P 2 ω →|ρ(0)| 2 {Δk 2 +α 2 } -1 . From the observed etching rate, the inverse characteristic length of the nonlinearity is measured. The strength of the nonlinearity is estimated from this series of measurements as χ.sup.(2) ˜1×10 -12 m/V.
It will be appreciated that in accordance with the present invention there has been provided a very large second-order nonlinearity in the near surface regions of bulk fused silica. The χ.sup.(2) coefficient is three orders of magnitude larger than that reported for fibers. The χ.sup.(2) value of 1×10 -12 m/V is of the same order as crystal quartz.
One possibility for the microscopic mechanism of this nonlinearity involves the creation and orientation of AlO 3/2 .spsb.- -Na + or other nonlinear complexes during the poling process. However, this model leads to questionably large values for the hyperpolarizability (i.e., the molecular nonlinearity). Another possibility is the generation of a large dc field (˜10 6 -10 7 V/cm) by charge transport under the poling conditions. This large field then interacts with the third-order susceptibility of the quartz to produce an effective second-order nonlinearity. Most likely, the mobile charge carriers in this temperature range are alkali ions such as Na + .
Because of the ready manufacturability of silica optical materials and their integration with semiconductor optoelectronics, this nonlinearity has important applications in waveguide and other optoelectronic devices. | A large second-order nonlinearity (χ.sup.(2) ˜1 pm/V˜0.2 χ.sup.(2) 22 of LiNbO 3 ) is induced in the near surface (˜4 μm) region of commercial fused silica optical flats by a temperature (250°-325° C.) and electric field (E˜5×10 4 V/cm) poling process. Once formed, the nonlinearity is roughly 10 3 -10 4 larger than that found in fiber second-harmonic experiments and is very stable at room temperature and laboratory ambient. The nonlinearity can be cycled by repeated depoling (temperature only) and repoling (temperature and electric field) processes. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of application Ser. No. 09/290,532, filed Apr. 12, 1999, now U.S. Pat. No. 6,107,688 issued Aug. 22, 2000, which is a continuation of application Ser. No. 08/892,718, filed Jul. 15, 1997, now U.S. Pat. No. 5,969,423, issued Oct. 19, 1999.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to a method of sputter deposition of an aluminum-containing film onto a semiconductor substrate, such as a silicon wafer. More particularly, the invention relates to using hydrogen and oxygen ,as with argon during the deposition of aluminum or aluminum alloys to form an aluminum-containing film which is resistant to hillock formation.
2. State of the Art
Thin film structures are becoming prominent in the circuitry components used in integrated circuits (“ICs”) and in active matrix liquid crystal displays (“AMLCDs”). In many applications utilizing thin film structures, low resistivity of metal lines (gate lines and data lines) within those structures is important for high performance. For example with AMLCDs, low resistivity metal lines minimize RC delay which results in faster screen refresh rates. Refractory metals, such as chromium (Cr), molybdenum (Mo), tantalum (Ta), and tungsten (W), have resistances which are too high for use in high performance AMLCDs or ICs. Additionally, the cost of refractory metals is greater than non-refractory metals. From the standpoint of low resistance and cost, aluminum (Al) is a desirable metal. Furthermore, aluminum is advantageous because it forms an oxidized film on its outer surfaces which protects the aluminum from environmental attack, and aluminum has good adhesion to silicon and silicon compounds.
An aluminum film is usually applied to a semiconductor substrate using sputter deposition. Sputter deposition is generally performed inside the vacuum chamber where a solid slab (called the “target”) of the desired film material, such as aluminum, is mounted and a substrate is located. Argon gas is introduced into the vacuum chamber and an electrical field is applied between the target and the substrate which strikes a plasma. In the plasma, gases are ionized and accelerated, according to their charge and the applied electrical field, toward the target. As the argon atoms accelerate toward the target, they gain sufficient momentum to knock off or “sputter” atoms and/or molecules from the target's surface upon impact with the target. After sputtering the atoms and/or molecules from the target, the argon ions, the sputtered atoms/molecules, argon atoms and electrons generated by the sputtering process, form a plasma region in front of the target before coming to rest on the semiconductor substrate, which is usually positioned below or parallel to the target within the vacuum chamber. However, the sputtered atoms and/or molecules may scatter within the vacuum chamber without contributing to the establishment of the plasma region and thus not deposit on the semiconductor substrate. This problem is at least partly resolved with a “magnetron sputtering system” which utilizes magnets behind and around the target. These magnets help confine the sputtered material in the plasma region. The magnetron sputtering system also has the advantage of needing lower pressures in the vacuum chamber than other sputtering systems. Lower pressure within the vacuum chamber contributes to a cleaner deposited film. The magnetron sputtering system also results in a lower target temperature, which is conducive to sputtering of low melt temperature materials, such as aluminum and aluminum alloys.
Although aluminum films have great advantages for use in thin film structures, aluminum has an unfortunate tendency to form defects, called “hillocks”. Hillocks are projections that erupt in response to a state of compressive stress in a metal film and consequently protrude from the metal film surface.
There are two reasons why hillocks are an especially severe problem in aluminum thin films. First, the coefficient of thermal expansion of aluminum (approximately 23.5×10 −6 /°C.) is almost ten times as large as that of a typical silicon semiconductor substrate (approximately 2.5×10 −6 /° C). When the semiconductor substrate is heated during different stages of processing of a semiconductor device, the thin aluminum film, which is strongly adhered to the semiconductor substrate, attempts to expand more than is allowed by the expansion of the semiconductor substrate. The inability of the aluminum film to expand results in the formation of the hillocks to relieve the expansion stresses. The second factor involves the low melting point of aluminum (approximately 660° C.), and the consequent high rate of vacancy diffusion in aluminum films. Hillock growth takes place as a result of a vacancy-diffusion mechanism. Vacancy diffusion occurs as a result of the vacancy-concentration gradient arising from the expansion stresses. Additionally, the rate of diffusion of the aluminum increases very rapidly with increasing temperature. Thus, hillock growth can thus be described as a mechanism that relieves the compressive stress in the aluminum film through the process of vacancy diffusion away from the hillock site, both through the aluminum grains and along grain boundaries. This mechanism often drives up resistance and may cause open circuits.
The most significant hillock-related problem in thin film structure manufacturing occurs in multilevel thin film structures. In such structures, hillocks cause interlevel shorting when they penetrate or punch through a dielectric layer separating overlying metal lines. This interlevel shorting can result in a failure of the IC or the AMLCD. Such a shorted structure is illustrated in FIG. 11 .
FIG. 11 illustrates a hillock 202 in a thin film structure 200 . The thin film structure 200 comprises a semiconductor substrate 204 , such as a silicon wafer, with a patterned aluminum layer 206 thereon. A lower dielectric layer 208 , such as a layer of silicon dioxide or silicon nitride, is deposited over the semiconductor substrate 204 and the patterned aluminum layer 206 . The lower dielectric layer 208 acts as an insulative layer between the patterned aluminum layer 206 and an active layer 210 deposited over the lower dielectric layer 208 . A metal line 212 is patterned on the active layer 210 and an upper dielectric layer 214 is deposited over the metal line 212 and the active layer 210 . The hillock 202 is shown penetrating through the lower dielectric layer 208 and the active layer 210 to short with the metal line 212 .
Numerous techniques have been tried to alleviate the problem of hillock formation, including: adding elements, such as tantalum, cobalt, nickel, or the like, that have a limited solubility in aluminum (however, this generally only reduces but not eliminates hillock formation); depositing a layer of tungsten or titanium on top or below the aluminum film (however, this requires additional processing steps); layering the aluminum films with one or more titanium layers (however, this increases the resistivity of the film); and using hillock resistant refractory metal films such as tungsten or molybdenum, rather than aluminum (however, as previously mentioned, these refractory metals are not cost effective and have excessive resistivities for use in high performance ICs and AMLCDs).
In particular with AMLCDs and, more particularly, with thin film transistor-liquid crystal displays (“TFT-LCDs”), consumer demand is requiring larger screens, higher resolution, and higher contrast. As TFT-LCDs are developed in response to these consumer demands, the need for metal lines which have low resistivity and high resistance to hillock formation becomes critical.
Therefore, it would be advantageous to develop an aluminum-containing material which is resistant to the formation of hillocks and a technique for forming an aluminum-containing film on a semiconductor substrate which is substantially free from hillocks, while using inexpensive, commercially-available, widely-practiced semiconductor device fabrication techniques and apparatus without requiring complex processing steps.
BRIEF SUMMARY OF THE INVENTION
The present invention relates to a method of introducing hydrogen and oxygen gas, along with argon gas, into a sputter deposition vacuum chamber during the sputter deposition of aluminum or aluminum alloys onto a semiconductor substrate, including but not limited to glass, quartz, aluminum oxide, silicon, oxides, plastics, or the like, and to the aluminum-containing films resulting therefrom.
The method of the present invention involves using a standard sputter deposition chamber, preferably a magnetron sputter deposition chamber, at a power level of between about 1 and 4 kilowatts (KW) of direct current power applied between a cathode (in this case the aluminum target) and an anode (flat panel display substrate—i.e., soda lime glass) to create the plasma (after vacuum evacuation of the chamber). The chamber is maintained at a pressure of between about 0.5 and 2.5 millitorr with an appropriate amount of argon gas, hydrogen gas, and oxygen gas flowing into the chamber. The argon gas is preferably fed at a rate between about 25 and 90 standard cubic centimeters per minute (“sccm”). The hydrogen gas is preferably fed at a rate between about 50 and 400 sccm. The oxygen gas is preferably fed at a rate between about 0.25 and 2 sccm (preferably in an atmospheric air stream). The ratio of argon gas to hydrogen gas is preferably between about 1:1 and about 1:6. The films with higher hydrogen/argon ratios exhibited smoother texture than lower hydrogen/argon ratios. The deposition process is conducted at room temperature (i.e., about 22° C.).
The aluminum-containing films resulting from this method have an average oxygen content between about 12 and 30% (atomic) oxygen in the form of aluminum oxide (Al 2 O 3 ) with the remainder being aluminum. The aluminum-containing films exhibit golden-yellow color when formed under the process parameters described. The most compelling attribute of the aluminum-containing films resulting from this method is that they are hillock-free, even after being subjected to thermal stresses.
Although the precise mechanical and/or chemical mechanism for forming these aluminum-containing films is not completely understood, it appears that the hydrogen gas functions in the manner of a catalyst for delivering oxygen into the aluminum-containing films. Although the flow of the oxygen gas into the vacuum chamber is small compared to the flow of argon gas and hydrogen gas, there is a relatively large percentage of oxygen present in the deposited aluminum-containing films. In experiments by the inventors, oxygen gas was introduced into the vacuum chamber without any hydrogen gas being introduced (i.e., only oxygen gas and argon gas introduced). The resulting films deposited on the substrate did not have a measurable amount (by x-ray photoelectron spectroscopy) of oxygen present.
As stated previously, oxygen is present in the deposited aluminum-containing film in the form of aluminum oxide. However, aluminum oxide is an insulator. It is counter-intuitive to form an insulative compound (which should increase the resistivity of the film) in a film which requires very low resistivity. However, it has been found that the formation of the aluminum oxide does not interrupt the conducting matrix of aluminum grains within the aluminum-containing film. Thus, the resistivity of the aluminum-containing film is surprisingly low, in the order of between about 6 and 10 micro ohm-cm. This is particularly striking in light of the fact that aluminum oxide is present in the range of between about 12 and 30% (atomic). The grain size of these aluminum-containing films is between about 400 and 600 angstroms (Å).
Aside from being substantially hillock-free and having a low resistivity (i.e., high conductivity), the resultant aluminum-containing films have additional desirable properties including low roughness, low residual stress, and good mechanical strength (as determined by a simple scratch test compared to pure aluminum or by the low compressive stress (between about −5×10 8 and −1×10 9 dyne/cm 2 ), which is considered to be an indication of high scratch resistance). Measurements of the aluminum-containing films have shown that the roughness before and after annealing is low compared to pure aluminum (about 600-1000 Å before annealing and 400-550 Å after annealing). Low roughness prevents stress migration, prevents stress-induced voids, and, consequently, prevents hillock formation. Additionally, low roughness allows for better contact to other thin films and widens the latitude of subsequent processing steps, since less rough films result in less translation of crests and valleys in the film layers deposited thereover, less diffuse reflectivity which makes photolithography easier, no need to clad the aluminum in the production of AMLCDs (rough aluminum traps charge which effects electronic performance [i.e., high or variable capacitance]), and more uniform etching.
The mechanical strength of the aluminum-containing films resulting from the process of the invention is higher than conventionally sputtered thin films of aluminum and some of its alloys. A high mechanical strength results in the resulting aluminum-containing films being resistant to both electromigration and stress induced voiding.
This combination of such properties is superior to that of thin films of aluminum and its alloys which are presently known. These properties make the aluminum-containing films of the present invention desirable for electronic device interconnects. These properties are also desirable in thin films for optics, electro-optics, protective coatings, and ornamental applications.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and distinctly claiming that which is regarded as the present invention, the advantages of this invention can be more readily ascertained from the following description of the invention when read in conjunction with the accompanying drawings in which:
FIGS. 1 and 2 are illustrations of scanning electron micrographs of an aluminum thin film produced by a prior art method before annealing and after annealing, respectively;
FIGS. 3 and 4 are illustrations of scanning electron micrographs of an aluminum thin film (Test Sample 1) produced by a method of the present invention before annealing and after annealing, respectively;
FIGS. 5 and 6 are illustrations of scanning electron micrographs of an aluminum thin film (Test Sample 2) produced by a method of the present invention before annealing and after annealing, respectively;
FIG. 7 is an x-ray photoelectron spectroscopy graph showing the oxygen content through the depth of an aluminum-containing film produced by a method of the present invention;
FIG. 8 is a graph of roughness measurements (by atomic force microscopy) of various aluminum-containing films made in accordance with methods of the present invention;
FIG. 9 is a cross-sectional side view illustration of a thin film transistor utilizing a gate electrode and source/drain electrodes formed from an aluminum-containing film produced by a method of the present invention;
FIG. 10 is a schematic of a standard active matrix liquid crystal display layout utilizing column buses and row buses formed from an aluminum-containing film produced by a method of the present invention; and
FIG. 11 is a cross-sectional side view illustration of interlevel shorting resulting from hillock formation.
DETAILED DESCRIPTION OF THE INVENTION
The method of the present invention preferably involves using a conventional magnetron sputter deposition chamber within the following process parameters:
Power (DC): between about 1 and 4 KW
Pressure: between about 0.5 and 2.5 millitorr
Argon Gas Flow Rate: between about 25 and 90 sccm
Hydrogen Gas Flow Rate: between about 50 and 400 sccm
Oxygen Gas Flow Rate: between about 0.25 and 2 sccm
Argon:Hydrogen Gas Ratio: between about 1:1 and 1:6
The operation of the magnetron sputter deposition chamber generally involves applying the direct current power between the cathode (in this case the aluminum target) and the anode (substrate) to create the plasma. The chamber is maintained within the above pressure range and an appropriate mixture of argon gas, hydrogen gas, and oxygen gas is delivered to the chamber. The aluminum-containing films resulting from this method have between about 12 and 30% (atomic) oxygen in the form of aluminum oxide (Al 2 O 3 ) with the remainder being aluminum.
It is believed that the primary hillock prevention mechanism is the presence of the hydrogen in the system, since it has been found that even using the system with no oxygen or virtually no oxygen present (trace amounts that are unmeasurable by present equipment and techniques) results in a hillock-free aluminum-containing film. It is also believed that the presence of oxygen in the film is primarily responsible for a smooth (less rough) aluminum-containing film, since roughness generally decreases with an increase in oxygen content in the film.
EXAMPLE 1
A control sample of an aluminum film coating on a semiconductor substrate was formed in a manner exemplary of prior art processes (i.e., no hydrogen gas present) using a Kurdex—DC sputtering system to deposit aluminum from an aluminum target onto a soda-lime glass substrate.
The substrate was loaded in a load lock chamber of the sputtering system and evacuated to about 5×10 −3 torr. The load lock was opened and a main deposition chamber was evacuated to about 10 −7 torr before the substrate was moved into the main deposition chamber for the sputtering process. The evacuation was throttled and specific gases were delivered into the main deposition chamber. In the control deposition, argon gas alone was used for the sputtering process. Once a predetermined amount of argon gas was stabilized (about 5 minutes) in the main deposition chamber, about 2 kilowatts of direct current power was applied between a cathode (in this case the aluminum target) and the anode (substrate) to create the plasma, as discussed above. The substrate was moved in front of the plasma from between about 8 and 10 minutes to form an aluminum-containing film having a thickness of about 1800 angstroms.
Table 1 discloses the operating parameters of the sputtering equipment and the characteristics of the aluminum film formed by this process.
TABLE 1
Control Sample
Sputtering Process Parameters
Power (KW)
2
Pressure (mtorr)
2.05
Gas Flow (sccm)
Argon = 90
Characterization Parameters and Properties
Thickness (Å)
1800
Stress (dyne/cm 2 ) (compressive)
−4.94 × 10 8 (C)
Roughness (Å)
1480 (unannealed)
2040 (annealed)
Resistivity (μΩ-cm)
2.70
Grain Size (Å)
1000-1200
Hillock Density
approx. 2 to 5 × 10 9 /m 2
The measurements for the characterization parameters and properties were taken as follows: thickness—Stylus Profilometer and scanning electron microscopy; stress—Tencor FLX using laser scanning; roughness—atomic force microscopy; resistivity—two point probe; grain size—scanning electron microscopy; and hillock density—scanning electron microscopy.
FIG. 1 is an illustration of a scanning electron micrograph of the surface of the aluminum film produced under the process parameters before annealing. FIG. 2 is an illustration of a scanning electron micrograph of the surface of the aluminum-containing film produced under the process parameters after annealing. Both FIGS. 1 and 2 show substantial hillock formation both before and after annealing.
EXAMPLE 2
Two test samples (test sample 1 and test sample 2) of an aluminum film coating on a semiconductor substrate were fabricated using the method of the present invention. These two test samples were also formed using the Kurdex—DC sputtering system with an aluminum target depositing on a soda-lime glass substrate.
The operating procedures of the sputtering system were essentially the same as the control sample, as discussed above, with the exception that the gas content vented into the main deposition chamber included argon, hydrogen, and oxygen (wherein oxygen is preferably introduced in an atmospheric air stream). Additionally, the pressure in the main deposition chamber during the deposition and the thickness of the aluminum-containing film were varied from that control sample for each of the test samples.
Table 2 discloses the operating parameters of the sputtering equipment and the characteristics of the two aluminum films formed by the process of the present invention.
TABLE 2
Test Sample 1
Test Sample 2
Sputtering Process Parameters
Power (KW)
2
2
Pressure (mtorr)
0.66
2.5
Gas Flow (sccm)
Argon = 25
Argon = 90
Hydrogen = 50
Hydrogen = 200
Oxygen Flow (sccm)
about 0.25 to 0.5
about 0.25 to 0.5
Characterization Parameters
and Properties
Thickness (Å)
2000
1800
Stress (dyne/cm 2 )
4.93 × 10 8 (T)*
−1.6 × 10 8 (C)**
Roughness (Å)
980 (unannealed)
640 (unannealed)
520 (annealed)
410 (annealed)
Resistivity (μΩ-cm)
6.4
7.2
Grain Size (Å)
400-600
400-600
Film Oxygen Content
approx. max. 25%
approx. max. 20%
Hillock Density
no hillocks present
no hillocks present
*Tensile
**Compressive
FIG. 3 is an illustration of a scanning electron micrograph of the surface of the Test Sample 1 before annealing. FIG. 4 is an illustration of a scanning electron micrograph of the surface of the Test Sample 1 after annealing. FIG. 5 is an illustration of a scanning electron micrograph of the surface of the Test Sample 2 before annealing. FIG. 6 is an illustration of a scanning electron micrograph of the surface of the Test Sample 2 after annealing. As it can be seen from FIGS. 3-6, no hillocks form on either sample whether annealed or not.
EXAMPLE 3
A number of aluminum-containing films were made at different ratios of Ar/H 2 and various system pressures were measured for oxygen content within the films. The oxygen gas flow rate was held constant at about 2 sccm and the power was held constant at 2 KW. The oxygen content was measure by XPS (x-ray photoelectron spectroscopy). The results of the measurements are shown in Table 3.
TABLE 3
Sample
Ar/H 2
Pressure
Oxygen Content
Number
(sccm)
Ar/H 2 Ratio
(millitorr)
Range (atomic %)
1
90/400
0.225
2.50
12-25
2
90/300
0.300
2.40
15-30
3
50/200
0.250
1.50
15-25
4
25/50
0.500
0.60
25-30
5
90/50
1.800
2.10
15-25
An XPS depth profile for sample 4 (Ar/H 2 (sccm)=25/50, pressure=0.60) is illustrated in FIG. 7 which shows the oxygen content varying on average between about 25 and 30% (atomic) through the depth of the film.
FIG. 8 illustrates the roughness of the aluminum-containing film samples. As FIG. 8 illustrates, the higher the amount of hydrogen gas delivered to the sputter deposition chamber (i.e., the lower the Ar/H 2 ratio—x-axis), the smoother the aluminum-containing film (i.e., lower roughness—y-axis).
FIG. 9 illustrates a thin film transistor 120 utilizing a gate electrode and source/drain electrodes which may be formed from an aluminum-containing film produced by a method of the present invention. The thin film transistor 120 comprises a substrate 122 having an aluminum-containing gate electrode 124 thereon which may be produced by a method of the present invention. The aluminum-containing gate electrode 124 is covered by an insulating layer 126 . A channel 128 is formed on the insulating layer 126 over the aluminum-containing gate electrode 124 with an etch stop 130 and contact 132 formed atop the channel 128 . An aluminum-containing source/drain electrode 134 which may be produced by a method of the present invention is formed atop the contact 132 and the insulating layer 126 , and contacts a picture cell electrode 136 . The aluminum-containing source/drain electrode 134 is covered and the picture cell electrode 136 is partially covered by a passivation layer 138 .
FIG. 10 is a schematic of a standard active matrix liquid crystal display layout 150 , utilizing column buses 152 and row buses 154 formed from an aluminum-containing film produced by a method of the present invention. The column buses 152 and row buses 154 are in electrical communication with pixel areas 156 (known in the art) to form the active matrix liquid crystal display layout 150 .
Having thus described in detail preferred embodiments of the present invention, it is to be understood that the invention defined by the appended claims is not to be limited by particular details set forth in the above description, as many apparent variations are possible without departing from the spirit or scope thereof | An aluminum-containing film having an oxygen content within the film. The aluminum-containing film is formed by introducing hydrogen gas and oxygen gas along with argon gas into a sputter deposition vacuum chamber during the sputter deposition of aluminum or aluminum alloys onto a semiconductor substrate. The aluminum-containing film so formed is hillock-free and has low resistivity, relatively low roughness compared to pure aluminum, good mechanical strength, and low residual stress. | 8 |
RELATED APPLICATION DATA
This application is a division of application Ser. No. 09/476,686, filed Dec. 30, 1999 (now U.S. Pat. No. 7,562,392), which claims priority benefit to provisional application 60/134,782, filed May 19, 1999. (Appendix A attached hereto is taken from the provisional application 60/134,782.)
The specification of the present application is essentially identical to that of a companion application filed by the same inventor on the same date, applicaton Ser. No. 11/620,999.
The technology detailed in the present application is also related to that detailed in application Ser. No. 09/343,104, filed Jun. 29, 1999 (now abandoned in favor of continuing application Ser. No. 10/764,430, filed Jan. 23, 2004); Ser. No. 09/292,569, filed Apr. 15, 1999 (now abandoned in favor of continuing application Ser. No. 10/379,393, filed Mar. 3, 2003, (now U.S. Pat. No. 7,263,203); Ser. No. 09/314,648, filed May 19, 1999 (now U.S. Pat. No. 6,681,028); 60/141,763, filed Jun. 30, 1999; 60/158,015, filed Oct. 6, 1999; 60/163,332, filed Nov. 3, 1999; 60/164,619, filed Nov. 10, 1999; Ser. No. 09/452,023, filed Nov. 30, 1999 (now U.S. Pat. No. 6,408,082); Ser. No. 09/452,021, filed Nov. 30, 1999 (now U.S. Pat. No. 7,044,395); and in U.S. Pat. No. 5,862,260.
INTRODUCTION
16 year old Bob struts into the coffee shop down from high school with a couple of buddies, a subtle deep pound in the ambient sound track lets them know they're in the right place. The three of them instinctually pull out of their pockets their audio Birddawgs (a small hand held unit about the size and style of an auto-door-alarm device, or “fob”), and when they see the tiny green light, they smile, high five, and push the big “GoFetch” button in synchrony. That tune will now be waiting for them at home, safely part of their preferred collection and ever-so-thankfully not lost to their collective bad memory (if they even knew the name of the artist and tune title in the first place!).
33 year old Mary is at home listening to the latest batch of holiday tunes being offered up over her 2-decade-long favorite radio station. She's spent many days now half-consciously culling the tunes for that perfect arrangement for the new year's bash that she regrettably agreed to host. 10:40 AM rolls around and some new tune catches her ear, a tune she knows can work well following the jingle-cats rendition of Strawberry Fields. She half jogs over to the stereo and hits the “GoFetch” button. In a few days, she'll sit down at the computer and put together the final sound track for the gala evening ahead, her play list dutifully waiting for her shuffling instructions and desired start time.
49 year old Jack (the financial analyst) is thoroughly bored sitting in the crowded gate D23 at Dulles. Droning 20 feet up and over his head is the airport network station, currently broadcasting the national weather report. As the segue to the business segment approaches, the teaser review mentions that they'll be having a report on today's rally in the bond market and the driving forces behind it. Jack pulls out his Birddawg-enabled Palm Pilot on the off-chance they actually will have a little depth in the reporting. Indeed, as the segment plays and starts discussing the convoluted effects of Greenspan's speech to the Internet-B-Free society, he taps the “GoFetch” button, knowing that once he gets back to his main browsing environment he will be able to follow dozens of links that the airport network has pre-assigned to the segment.
The foregoing and other features and advantages will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a device according to one embodiment.
FIG. 2 is a block diagram of a system in which the device of FIG. 1 may be utilized.
DETAILED DESCRIPTION
Referring to FIG. 1 , a device 10 according to one embodiment includes a microphone 12 , an A/D converter 13 , a processor 14 , one or more indicators 16 , one or more buttons 18 , a wireless interface 20 , and a power source 22 .
The device can be packaged in a small plastic housing, preferably as small as is practical (e.g., sized and configured to serve as a key chain ornament, perhaps akin to the Tomagatchi toys that were recently popular). The housing has one or more small holes to permit audio penetration through the housing to the microphone 12 .
The processor 14 can take various forms, including a dedicated hardware device (e.g., an ASIC), a general purpose processor programmed in accordance with instructions stored in non-volatile RAM memory, etc.
The indicators 16 can be as simple as a single LED lamp, or as complex as an alphanumeric LCD or other multi-element display. In one embodiment, the indicator simply indicates when the processor has decoded a watermark in audio sensed by the microphone. More elaborate signaling techniques can of course be used, including two- or three-color LEDs that can be used to signal different states with different colors, indicators with flashing patterns or changing displays, etc.
The buttons 18 are used by the user to indicate an interest in the audio just-heard. In one embodiment, there is a single button 18 , and it is emblazoned with a stylized legend that can serve as a trademark or service mark, e.g., GetIt!, GoFetch, Birddawg, something Batman-esque (“Wham,” “Zappp,” “Pow!!,” etc.), or something more mundane (e.g., Capture).
The power source 22 can be a battery, solar cell, storage capacitor, or other source of energy suitable for powering the components of the device 10 .
The wireless interface 20 serves to exchange data with a relay station 24 ( FIG. 2 ). In one embodiment, the interface is radio-based, and provides a one-way communications channel. In other embodiments other wireless technologies can be used (e.g., IR), and/or two-way communication can be provided.
The relay station can be a cellular repeater (if the interface transmits using cellular frequencies and protocols), or a local receiver, e.g., associated with the user's computer. The relay station can also be a paging system relay station (e.g., as are used for two-way pagers), or may be a low earth orbit satellite-based repeater.
In operation, the processor monitors the ambient audio for the presence of encoded data, e.g., a digital watermark, and decodes same. If power considerations permit, the device is “always-on.” In other embodiments, one of the buttons 18 can be used to awaken the device. In such other embodiments, another button-press can serve to turn-off the device, or the device can power-down after a predetermined period, e.g., of not sensing any watermarked audio.
A number of techniques for watermarking audio (and decoding same) are known, as illustrated by U.S. Pat. Nos. 5,862,260, 5,963,909, 5,940,429, 5,940,135, 5,937,000, 5,889,868, 5,833,432, 5,945,932, WO9939344 (corresponding to U.S. application Ser. No. 09/017,145, now U.S. Pat. No. 6,145,081), and WO9853565 (corresponding to U.S. application Ser. Nos. 08/858,562 and 08/974,920, now U.S. Pat. Nos. 5,940,135 and 6,175,627, respectively). Commercially-available audio watermarking software includes that available from AudioTrack, Verance (formerly Aris/Solana), Cognicity, Liquid Audio, and others.
The data payload encoded by the watermark (the audio-ID) may take various forms. One is a Digital Object Identifier—an ID corresponding to the standardized digital object numbering system promulgated by the International DOI Foundation (www.doi.org). Another is to include plural data fields variously representing, e.g., the name of the publisher, the name of the artist, the title of the work, the date of publication, etc., etc. Another is to encode a unique identifier (UID), e.g., of 16-64 bits. The UID serves as an index to a remote database where additional information (e.g., publisher, artist, title, date of publication, etc., are stored).
The data transmitted from the device 10 to the relay station 24 typically includes some or all of the watermark payload data, and also includes data identifying the device 10 , or its user (user-ID data). Again, this data can include several data fields (e.g. user name, audio delivery information such as email address or URL, age, gender, model of device 10 , etc.). Alternatively, a serial number or other unique identifier can be used, which serves as an index to a database have a corresponding record of information relating to the user and/or device.
The audio-ID and user-ID data are typically formatted and encoded by the device 10 according to a protocol that provides error correcting, framing, and other data useful in assuring reliable transmission to the relay station, and/or for further transport.
Some embodiments of device 10 recognize just a single form of watermarking, and can understand only payload data presented in a single format. In other embodiments, the device may be capable of recognizing watermarking according to several different techniques, and with several different payload formats. This latter functionality can be achieved, e.g., by cyclically trying different decoding techniques until one that produces valid output data (e.g., by reference to a checksum or other indicia) is obtained. That decoding technique and payload interpretation can thereafter be used until valid output data is no longer obtained.
In some embodiments, the device 10 transmits data to the relay station at the moment the user presses the button 18 . In other embodiments, a store-and-forward mode is used. That is, when the user presses the button 18 , the decoded watermark data is stored in memory within the device. Thereafter, e.g., when the device is coupled with a “nest” or “holster” at the user's computer (or when download capability is otherwise activated), the stored data is downloaded—either through that device or otherwise.
The infrastructure between the device 10 and delivery of the audio to its ultimate destination can take myriad forms. One is shown in FIG. 2 . In this arrangement, some or all of the data received by the relay station 24 is routed through the internet 26 to a server 28 . (The server 28 can be a “MediaBridge” server of the type described, e.g., in the assignee's applications 60/164,619, filed Nov. 10, 1999, and Ser. No. 09/343,104, filed Jun. 29, 1999.) Server 28 parses the data and routes some or all of it to a data repository 30 at which the audio requested by the user is stored. This repository, in turn, dispatches the audio to the user (e.g., to a computer, media player, storage device, etc.), again through the internet. (Address information detailing the destination 32 of the audio may be included in the data sent from the device 10 , or can be retrieved from a database at the server 28 based on a user-ID sent from the device 10 .)
In some embodiments, the repository 30 (which may be co-located with server 28 , or not) includes various data beyond the audio itself. For example, the repository can store a collection of metadata (e.g., XML tags) corresponding with each stored item of audio. This metadata can be transmitted to the user's destination 32 , or can be used, e.g., for rights management purposes (to limit the user's reproduction or re-distribution rights for the audio, etc.), to establish a fee for the audio, etc. One suitable metatag standard is that under development by <indecs> (Interoperability of Data in E-Commerce Systems, www.indecs.org).
The audio data can be delivered in streaming form, such as using technology available from RealNetworks (RealAudio), Microsoft (Windows Media Player), MP3, Audiobase, Beatnik, Bluestreak.com, etc. The former three systems require large (e.g., megabytes) player software on the receiving (client) computer; the latter do not but instead rely, e.g., on small Java applets that can be downloaded with the music.
Alternatively, the audio can be delivered in a file format. In some embodiments the file itself is delivered to the user's destination 32 (e.g., as an email attachment). In others, the user is provided a URL to permit access to, or downloading of, the audio. (The URL may be a web site that provides an interface through which the user can pay for the requested music, if pre-payment hasn't been arranged.)
The user's destination 32 is typically the user's own computer. If a “live” IP address is known for that computer (e.g., by reference to a user profile database record stored on the server 28 ), the music can be transferred immediately. If the user's computer is only occasionally connected to the internet, the music can be stored at a web site (e.g. protected with a user-set password), and can be downloaded to the user's computer whenever it is convenient.
In other embodiments, the destination 32 is a personal music library associated with the user. The library can take the form, e.g., of a hard-disk or semiconductor memory array in which the user customarily stores music. This storage device is adapted to provide music data to one or more playback units employed by the user (e.g. a personal MP3 player, a home stereo system, a car stereo system, etc.). In most installations, the library is physically located at the user's residence, but could be remotely sited, e.g. consolidated with the music libraries of many other users at a central location.
The personal music library can have its own internet connection. Or it can be equipped with wireless capabilities, permitting it to receive digital music from wireless broadcasts (e.g. from a transmitter associated with the server 28 ). In either case, the library can provide music to the user's playback devices by short-range wireless broadcast.
In many embodiments, technology such as that available from Sonicbox, permits audio data delivered to the computer to be short range FM-broadcast by the user's computer to nearby FM radios using otherwise-unused radio spectrum.
Some implementations support several different delivery technologies (e.g., streaming, file, URL), and select among them in accordance with the profiles of different users.
Payment for the audio (if needed) can be accomplished by numerous means. One is by charging of a credit card account associated with the user (e.g., in a database record corresponding to the user-ID).
Some implementations make use of secure delivery mechanisms, such as those provided by InterTrust, Preview Systems, etc. In addition to providing secure containers by which the audio is distributed, such systems also include their own secure payment facilities.
By such arrangements, a user can conveniently compile an archive of favorite music—even while away from home.
To provide a comprehensive disclosure without unduly lengthening this specification, the disclosures of the applications and patents cited above are incorporated herein by reference.
Having described and illustrated the principles of my technological improvements with reference to a preferred embodiment and several variations thereof, it should be apparent that the detailed embodiments are illustrative only and should not be taken as limiting the scope of my work.
For example, while the foregoing is illustrated with reference to a button that is activated by the user to initiate capture of an audio selection, other interfaces can be used. For example, in some embodiments it can be a voice-recognition system that responds to spoken commands, such as “capture” or “record.” Or it can be a form of gesture interface.
Likewise, while the foregoing is illustrated with reference to a stand-alone device, the same functionality can be built-into radios (including internet-based radios that receive wireless IP broadcasts), computer audio systems, and other appliances. In such case the microphone can be omitted and, in some cases, the wireless interface as well. (The data output from the device can be conveyed, e.g., through the network connection of an associated computer, etc.)
Moreover, while the foregoing is illustrated with reference to an embodiment in which audio, alone, is provided to the user, this need not be the case. As in the Dulles airport scenario in the introduction, the server 28 can provide to the user several internet links associated with the sensed audio. Some of these links can provide commerce opportunities (e.g., to purchase a CD on which the sensed audio is recorded). Others can direct the user to news sites, concert schedules, fan-club info, etc. In some such embodiments, the ancillary information is provided to the user without the audio itself.
Although not particularly detailed, the data provided to the user's destination typically includes information about the context in which the data was requested. In a simple case this can be the time and date on which the user pressed the Capture button. Other context information can be the identification of other Birddawg devices 10 that were nearby when the Capture button was pressed. (Such information can be gleaned, e.g., by each device transmitting a brief WhoAmI message periodically, receiving such messages from other nearby devices, and logging the data thus received.)
Still other context information might be the location from which the Capture operation was initiated. This can be achieved by decoding of a second watermark signal, e.g., on a low level white-noise broadcast. The public address system in public places, for example, can broadcast a generally-indiscernable noise signal that encodes a watermark signal. Devices 10 can be arranged to detect two (or more) watermarks from the same audio stream, e.g., by reference to two pseudo-random sequences with which the different watermarks are encoded. One identifies the audible audio, the other identifies the location. By such an arrangement, for example, the device 10 can indicate to the server 28 (and thence to the user destination 32 ) the location at which the user encountered the audio. (This notion of providing location context information by subliminal audio that identifies the location has powerful applications beyond the particular scenario contemplated herein.)
In some embodiments, the device 10 can buffer watermark information from several previous audio events, permitting the user to scroll back and select (e.g., in conjunction with a screen display 16 ) the ID of the desired audio.
An arrangement like the foregoing may require that the decoded watermark information be interpreted for the user, so that the user is not presented simply a raw binary watermark payload. The interpreted information presented to the user can comprise, e.g., the source (CNN Airport News, WABC Radio, CD-ROM, MTV), the artist (Celine Dion), the title (That's the Way It Is), and/or the time decoded (3:38:02 p.m.), etc.
One way to achieve the foregoing functionality is to convey both the binary UID payload and abbreviated text (e.g., 5- or 6-bit encoded) through the watermark “channel” on the audio. In one such arrangement, the watermark channel conveys data a UID, four characters of text, and associated error-correcting bits, every ten seconds. In the following ten seconds the same UID is conveyed, together with the next four characters of text.
Another way to achieve such functionality is to provide a memory in the device 10 that associates the watermark payload (whether UID or field-based) with corresponding textual data (e.g., the source/artist/title referenced above). A 1 megabyte semiconductor non-volatile RAM memory, for example, can serve as a look-up table, matching code numbers to artist names and song titles. When the user queries the device to learn the identify of a song (e.g., by operating a button 18 ), the memory is indexed in accordance with one or more fields from the decoded watermark, and the resulting textual data from the memory (e.g. source/artist/title) is presented to the user.
Such a memory will commonly require periodic updating. The wireless interface 20 in device 10 can include reception capabilities, providing a ready mechanism for providing such updated data. In one embodiment, the device “awakens” briefly at otherwise idle moments and tunes to a predetermined frequency at which updated data for the memory is broadcast, either in a baseband broadcast channel, or in an ancillary (e.g. SCA) channel.
In variants of the foregoing, internet delivery of update data for the memory can be substituted for wireless delivery. For example, a source/artist/title memory in the device 10 can be updated by placing the device in a “nest” every evening. The nest (which may be integrated with a battery charger for the appliance) can have an internet connection, and can exchange data with the device by infrared, inductive, or other proximity-coupling technologies, or through metal contacts. Each evening, the nest can receive an updated collection of source/artist/title data, and can re-write the memory in the device accordingly. By such arrangement, the watermark data can always be properly interpreted for presentation to the user.
The “Capture” concepts noted above can be extended to other functions as well. One is akin to forwarding of email. If a consumer hears a song that another friend would enjoy, the listener may send a copy of the song to the friend. This instruction can be issued by pressing a “Send” button, or by invoking a similar function on a graphical (or voice- or gesture-responsive) user interface. In response, the device so-instructed can query the person as to the recipient. The person can designate the desired recipient(s) by scrolling through a pre-stored list of recipients to select the desired one. (The list can be entered through a computer to which the device is coupled.) Alternatively, the user can type-in a name (if the device provides a keypad), or a portion thereof sufficient to uniquely identify the recipient. Or the person may speak the recipient's name. As is conventional with hands-free vehicle cell phones, a voice recognition unit can listen to the spoken instructions and identify the desired recipient. An “address book”-like feature has the requisite information for the recipient (e.g., the web site, IP address, or other data identifying the location to which music for that recipient should stored or queued, the format in which the music should be delivered, etc.) stored therein. In response to such command, the appliance dispatches instructions to the server 28 , including an authorization to incur any necessary charges (e.g., by debiting the sender's credit card). Again, the server 28 attends to delivery of the music in a desired manner to the specified recipient.
Still further, a listener may query the device (by voice, GUI or physical button, textual, gesture, or other input) to identify CDs on which the ambient audio is recorded. Or the listener may query the device for the then-playing artist's concert schedule. Again, the appliance can contact a remote database and relay the query, together with the user ID and audio ID data. The database locates the requested data, and presents same to the user—either through a UI on device 10 , or to the destination 32 . If desired, the user can continue the dialog with a further instruction, e.g., to buy one of the CDs on which the then-playing song is included. Again, this instruction may be entered by voice, GUI, etc., and dispatched from the device to the server, which can then complete the transaction in accordance with pre-stored information (e.g. credit card account number, mailing address, etc.). A confirming message can be relayed to the device 10 or destination 32 for presentation to the user.
While the foregoing particularly contemplates audio, the principles detailed above find applications in many other media, and in many other applications of the MediaBridge server 28 .
Moreover, while the foregoing particularly contemplates watermarks as the channel by which audio is identified, in other embodiments different techniques can be used. For example, digital radio protocols provide ID fields by which audio can be identified. Similarly, IP protocols for internet delivery of radio include identification fields within their packet formats. Accordingly, audio distributed according to formats that include audio IDs therein can likewise be employed.
Accordingly, I claim all such modifications as may fall within the scope and spirit of the following claims, and equivalents thereto. | A camera-equipped portable device captures visual information (e.g., from a movie), ascertains a corresponding identifier, and uses the identifier to enable one or more further functions. One of these can be internet search. Such functionality can also be based on digital data—without requiring a camera capability. | 6 |
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