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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to mobile apparatus preferably carried on the frame of a tractor for movement through a field of row crops, such as cotton to agitate the plants in the rows being transversed and to knock insects therefrom so that the insects fall into a plurality of open pans moving between the rows whereby the insects are completely incinerated destroyed by the heat and flame from burners located in the open topped pans.
2. State of the Prior Art
Apparatus for removing insects from field row crops such as cotton, and for destroying the insects removed from the plants, have been previously proposed, Representative examples of the prior art proposals are found in the following patents:
______________________________________Pat No. Patentee Issue Date______________________________________ 803,371 Tanner Oct. 31, 19051,530,681 Long Mar. 24, 19252,564,774 Allen Aug. 21, 19512,608,023 Dillon Aug. 26, 19522,617,229 Huseby Nov. 11, 19522,740,228 Riggs Apr. 3, 1956______________________________________
SUMMARY OF THE INVENTION
This invention provides an improved means for removing and destroying insects from multiple rows of row crops in a single pass through a field. While the invention is particularly advantageous for use in removing and destroying boll weevils and larvae from cotton plants, it may also be used for removing and destroying other types of insects from cotton and from other types of row crops.
It is an object of this invention to provide an improved tractor mountable insect collecting and destroying apparatus for collecting insects from growing plants in multiple rows by agitating the plants so that the insects drop into pans carried by the apparatus beneath the agitating means, and for destroying the insects by burning in the open topped pans heated by elongated burners mounted longitudinally therein.
It is an object of this invention to provide insect removing and destroying apparatus which includes a supporting frame which is readily attachable to and detachable from the front end of a tractor, a plurality of transversely spaced, elongated metal pans suspended beneath the frame, flexible agitator means for each pan for agitating the sides of plants in the rows passed by the pans and for knocking bugs therefrom, an elongated gas burner in each pan for heating the pans and destroying insects falling therein, a vertically adjustable agitator rod mounted above the pans and extending the full width of the apparatus for knocking insects from the tops of the plants as the apparatus passes along the rows, yieldable mounting means for each pan enabling each pan to swing rearwardly and upwardly when encountering an unyielding object, and motor operated means for selectively raising and lowering all of the pans simultaneously.
BRIEF DESCRIPTION OF THE DRAWINGS
With the foregoing more important objects and features in view and such other objects and features which may become apparent as this specification proceeds, the invention will be understood from the following description taken in conjunction with the accompanying drawings, in which like characters of reference are used to designate like parts, and in which:
FIG. 1 is a perspective view showing the invention mounted on the front end of a row crop tractor which is shown in phantom;
FIG. 2 is a vertical sectional view taken along line 2--2 in FIG. 1;
FIG. 3 is a partial front elevational view of the right hand portion of the invention shown in FIG. 1;
FIG. 4 is a diagramatic view of the gas supply and distribution system for the gas burners included in the invention;
FIG. 5 is a side elevational view of the invention on a reduced scale;
FIG. 6 is a partial bottom plan view of one of the gas burner pipes included in the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings and particularly to FIG. 1, the insect removing and destroying apparatus of this invention, generally indicated by the numeral 10, is illustrated as being detachably mounted forward of the front wheels 8 of a row crop tractor 9. The apparatus 10 includes a frame having a pair of parallel, transversely spaced longitudinal support members 11 and 12, and a pair of longitudinally spaced parallel transverse support members 14 and 15. The longitudinal support members 11 and 12 are preferably heavy gauge angle iron bars which extend rearwardly along opposite sides of the front end of the tractor and are bolted to the tractor by bolts 13. Major portions of the longitudinal support members 11 and 12 project forwardly of the tractor's front wheels 8 and have mounted thereon the parallel transverse support member 14 and 15, which are, for example, elongated pipes. The front transverse support member 14 is clamped on top of the longitudinal support members 11 and 12 by a pair of U-bolt clamps 16, 16. Each of the clamps 16 comprises a pair of U-bolts 17, 17 straddling the front transverse support member 14 on opposite sides of one of the longitudinal support members 11 and 12 and a clamping plate 18, positioned on the underside of the respective longitudinal support member, which is provided with apertures through which the downwardly extending legs of the U-bolts project. Nuts 19 are threaded on the ends of the U-bolts 17, 17 beneath the clamping plate 18 and are tightened against the plate 18 to draw the U-bolts downwardly and thus to secure the front transverse support member 14 firmly against the top of the longitudinal support members 11 and 12.
The rear transverse support member 15 is rotatably mounted on journal bearings 20, 21 affixed on top of the longitudinal support members 11 and 12 respectively and is prevented from axial motion. The member 15 may be rotated through an appropriate arc by means of a double acting fluid piston and cylinder motor 22. The cylinder 23 of the motor 22 is pivotally attached by a clevis 24 to a bracket 25 laterally projecting from the longitudinal support member 12 to which it is secured by welding, or other appropriate means. The end of the piston rod 26 extending from the cylinder 23 is forked and pivotally connected to a lever arm 27 non-rotatably affixed to the transverse support bar 15. Hydraulic lines extend from the cylinder 23 to the cab 7 of the tractor 9 where suitable hydraulic controls (not shown) for operating the motor 22 are mounted.
Suspended beneath the transverse support members 14 and 15 are a plurality of elongated intermediate insect destroying boat-shaped metal pans 28, and elongated right and left end pans 29 and 30. The end pans 29 and 30 and the three intermediate pans 28 are approximately equally spaced along the transverse support bars 14 and 15. Sufficient space is provided between adjacent pans to permit the passage of rows of cotton C, or other crops, between the pans as the tractor, with the insect removing and destroying apparatus of this invention attached, moves along the rows (FIG. 3). Each of the three intermediate pans 28 and each of the end pans 29 and 30 are supported at the rear by a bracket arm 31, affixed to and depending radially from the rear transverse support member 15, and by a chain 32 secured to the lower end of the bracket 31 by one end, and fastened to a ring 33 welded at the rear of the pan. The front end of each of the pans is pivotally supported from the front transverse support member 14 by a link 34 which is pivotally connected at its upper end between a pair of spaced parallel ears 35, 35 affixed to and depending from the member 14 by a pivot pin 36 (FIG. 2). The lower end of each of the links 34 is pivotally connected between the upper forked end 37 of an upstanding bracket 38 by a pivot pin 39. The bracket 38 has an arched base 40 with opposite end flanges 41, 41 that are shaped to conform to the inside surface of one of the respective pans and that are welded thereto.
It will be noted that the front transverse support member 14 is located directly above the front portions of the burner pans and at the front of the vehicle 9 instead of at the rear thereof. Such support member 14 serves to knock the insects from the plants and to drop them into the open topped burner pans, whereby they are incinerated by the hot pans and by the flame from the perforated burners.
The insect destroying metal pans 28, 29 and 30 can be lifted to provide ground clearance sufficient for turning or road travel by actuating the hydraulic motor 22 to force the piston rod 26 outwardly thereby turning the crank arm 27 forwardly and the bracket arms 31 rearwardly. Rearward motion of the bracket arms 31 from the position shown in FIG. 1 pulls the pans 28, 29 and 30 rearwardly and simultaneously lifts the pans above the ground. As the pans are pulled to the rear, the links 34 swing upwardly and lift the front ends of the pans so that the pans move rearwardly and upwardly in substantially parallel relationship to the ground. The pans are lowered by reversing the hydraulic motor 22 to retract the piston rod 26 and pull the crank arm 27 rearwardly thereby swinging the brackets 31 down.
The three intermediate metal pans 28 are substantially identical in structure because they are each designed to catch insects which are knocked from plants in rows on both sides of the pans along which the pans travel. The end pans 29 and 30 are of less width then the pans 18 because they are are designed to catch bugs knocked from the outside branches of plants in only the outside rows along which the apparatus 10 moves. The apparatus 10, as shown in FIG. 1, is designed to remove and destroy insects from four crop rows at a time, thus it requires three intermediate pans 28 and the two end pans 29 and 30. By extending the length of the transverse support bars 14 and 15 equally on opposite sides of the longitudinal support bars 11 and 12, and by adding additional intermediate pans 28, the apparatus 10 can be made to service more than four crop rows at one time. The intermediate pans 28 are preferably about 38 inches wide and about 45 inches long while the end pans 29 and 30 are preferably about 24 inches wide and about 45 inches long. Each of the pans 28, 29 and 30 includes an elongated perforated gas burner pipe 42 that runs the length of the pan and projects through an aperture 43 in the rear wall of the pan. The forward end 44 of the burner pipe 42 is curved upwardly and connected to a gas supply line 46 by suitable coupling means 45.
The bottom side of the burner pipe 42 includes multiple jet apertures 47 spaced lengthwise along the pipe in two longitudinal rows 48 and 49 as seen in FIG. 6. Each of the rows of jet apertures is offset circumferentially from a median longitudinal line at the bottom of the pipe so that burner gases are directed downwardly and laterally on each side of the pipe. The gases, when ignited, produce flames which impinge upon the bottom inner surface of the pan on opposite sides of the burner for heating the pan to a temperature sufficient to burn insects falling into the pan. The flame from the burner perforations or jets also directly contacts and incinerates the insects within the pans. The burner pipe 42 is closed at its rear end by a cap 50, or optionally by a plug (not shown) and is slightly elevated from the bottom of the pan to facilitate self-cleaning as it moves forward. The forward end portion of the pipe 42 extends beneath the arched base 40 of the bracket 38 which locates the pipe 42 with respect to the bottom of the pan. The intermediate pans 28 have gently outwardly and upwardly curved sides 51, 51 (FIG. 3) on opposite sides of a central bottom runner portion 52. The upwardly curved sides 51, 51 funnel insects to the burner pipe 42 and heated area adjacent thereto. Flanges 53, 53 of rubber, or other elastomeric material, and approximately three inches wide, are secured along the outboard edges of the sides 51, 51 by rivets 54 so as to protect the plants C from abrasive damage. The two end pans 29 and 30 each have one gently outwardly and upwardly curved side 51 on the inside of a bottom runner portion 52 and a steep outer side 51'. The gently curved sides 51 of the end pans 29 and 30 have elastomeric flanges 53 secured along the outboard edges thereof. The steep sides 51' of the pans 29 and 30 are on the outside of the apparatus 10 and do not require a protective elastomeric flange 53 because the steep sides normally are located intermediately between a pair of adjacent rows of plants and do not contact the plants. Above each of the pans 28, 29 and 30 is a vertically adjustable resilient agitator or apron generally indicated at 56 mounted upon an L-shaped bracket 57. The bracket 57 has a generally horizontal foot portion 58 and an integral upright portion 59. The end of the foot portion 58 is attached to the base 40 of the bracket 38 and extends rearwardly therefrom. The upright portion 59 has a plurality of longitudinally spaced apertures 60 through which bolts, screws or other suitable fasteners are selectively applied to secure the agitator 56 to the bracket. The agitators or aprons 56 each comprise a resilient strip 62, of rubber or other suitable elastomeric material extending laterally from the upright portion 59 of the bracket 57 and a clamp 63 transversely embracing the strip 62. The clamp 63 is secured at a selected height along the length of the upstanding bracket portion 59 by passing bolts or other fasteners through vertically spaced apertures in the clamp and through selected ones of the apertures 60 in the upstanding bracket portion 59. The resilient agitator strips 62 for each of the pans 28, 29 and 30 are of a length to extend transversely across substantially the full width of the pan. In the case of the intermediate pans 28, the strip 62 is fastened medially of its length to the bracket 57 so that equal portions of the strip extend laterally from the bracket 57 over the opposite sides of the pan 28. In the case of the end pans 29 and 30, the strip 62 is secured by one end to the bracket 57 so that the resilient agitator strip extends laterally from only one side of the bracket 57. The agitators 56 are not motor operated but they simply react to the force exerted by the plants C brushing against them as the apparatus 10 moves along the plant rows.
As an alternate form (not shown), the agitators 56 may comprise metal plates which are hinged adjacent to the upstanding portion 59 of the bracket 57 and which are spring loaded to extend laterally from the bracket 57 across one side of the pan. In the case of the intermediate pans 28, a pair of spring loaded, hinged metal plates would be provided to extend laterally across the pan 28 in opposite directions. In the case of the end pans 29 and 30, only one hinged plate would be required.
A rigid horizontal agitator rod 64 extends transversely above all of the pans 28, 29 and 30 for the full width of the apparatus 10. A pair of spaced vertical rods 65, 65 which are rigidly connected to the agitator rod 64 as by welding, adjustably support the rod 64 from a pair of mounting brackets 67, 67 fastened to the longitudinal support members 11 and 12 respectively. The mounting brackets 67 each comprise a vertically oriented open ended cylinder 68 (FIG. 2) for slidably receiving one of the vertical support rods 65. The cylinder 68 has laterally extending flanges 69, 69 by which the bracket 67 is bolted or otherwise secured to one of the longitudinal support bars 11 and 12. The horizontal agitator rod 64 can be adjusted vertically to a selected height above the insect destroying pans 28, 29 and 30 and beneath the longitudinal support bars by sliding the vertical support rods 65 up or down within the mounting bracket cylinders 68 and by locking the rods within cylinders 68 at a selected position by tightening set screws 70 in the cylinders 68 which bear against the rod 65. The horizontal agitator rod 64 is adjusted to a suitable height for brushing against the tops of the plants C as shown in FIG. 3. The functions of the rigid horizontal agitator bar 64 and of the resilient agitators 56 are to brush against the tops and sides of the plants respectively, as the apparatus 10 moves along the crop rows, with sufficient force to knock insects from the plants. The insects knocked from the plants tend to fall toward the ground and are collected in the pans 28, 29 and 30 moving between the rows on top of the ground. The pans 28, 29 and 30 are of sufficient length so that when the insects are knocked from the plants by the agitators 56 and 64, most of the insects will fall within the pans and will be destroyed by the flames from the burner pipe 42 or by contact with the heated metal pans. The opening 43 at the rear end of the pans 28, 29 and 30 allows destroyed insects and other debris to pass out of the pan by the normal movement of the pan in operation.
The burner pipes 42 are supplied with a combustible gas, such as propane, from a gas tank 71 mounted on the longitudinal support members 11 and 12 in front of the tractor 9 as shown in FIG. 5. The system for the distribution of gas from the gas tank 71 is shown diagramatically in FIG. 4. It includes a main on-off valve 72 on top of the gas tank and a high pressure gas regulator valve 73, adjustable between about 45 and 100 PSIG, serially connected in a conduit 74 going from the tank 71 to a gas distributor manifold 75. Branching off from the manifold 75 are five individual lines feeding the gas burner pipes 42 in the two end pans 29, and 30 and in the three intermediate pans 28. Five individual gas control valves 76 are provided adjacent the manifold 75 for separate control of the five individual gas lines 46. The lines 46 leading from the individual gas control valves 76 are preferably flexible hoses. The conduit 74 leading to the manifold 75 is a rigid pipe which is supported by a bracket 77 strapped to the tank 71.
In use, the main gas valve 72 is turned on and the regulator valve 73 is adjusted to the desired gas pressure for distribution to the gas burners 42. In normal use, all of the individual regulator valves 76 are turned on to supply gas to the burner pipes in each of the pans 28, 29 and 30. The gas jets from the burner pipes 42 are preferably ignited manually, but an automatic ignition (not shown) may be optionally provided in each pan if desired. Once the burners 42 are ignited, the apparatus 10 is ready for travel and the tractor begins its movement through a field of row crops such as cotton, parallel to the rows so that the pans 28, 29 and 30 are spaced between the rows. The pans are lowered by operating the hydraulic motor 22 in a manner already described so that the pans slide on top of the ground or just above the ground. If any of the pans encounters an obstruction, such as a stone or other object close to the ground, the pan automatically swings rearwardly and upwardly because of its flexible support from the front transverse support rod 14 by hinged links 34 and from the rigid bracket arm 31 by chain 32. The motion of the apparatus 10 through the field causes the rigid agitator bar 64 and the agitators 56 to brush the plants in the rows with sufficient impact to knock insects from the plants. The insects falling into the pans 28, 29 and 30 are burned and the debris exits from the pans through the rear opening 43. At the end of the row, the operator may lift the pans by means of the hydraulic motor 22 while turning and positioning the apparatus for another pass through the field.
While in the foregoing there has been described and shown a preferred embodiment of the invention, various modifications and equivalents may be resorted to within the spirit and scope of the invention as claimed.
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Tractor mountable apparatus for collecting and destroying insects from multiple rows of plants, such as cotton, as the tractor passes along the rows is disclosed. The apparatus comprises a supporting frame including longitudinal support members mountable upon the front end of a tractor to project forward rather than rearwardly thereof, and transverse support members carried by the longitudinal support members. A plurality of insect destroying open topped metal pans are suspended from the transverse support members and are spaced to pass between rows of plants as the apparatus moves through a field. Each of the pans has an elongated perforated gas fired burner for heating the pan and for completely incinerating insects falling into the pans and laterally extending resilient agitator means or flexible aprons mounted thereon for knocking insects from the side branches of the plants. A vertically adjustable transverse agitator rod extends across the entire width of the apparatus directly above the pans for engaging the tops of plants and for knocking insects therefrom into the pans. Each of the pans is mounted to swing rearwardly and upwardly when encountering a stone or other low lying ground object, and motor operated means is provided for simultaneously raising and lowering all of the pans at the will of an operator.
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ORIGIN OF THE INVENTION
The invention described herein was made in the performance of work under a NASA contract, and is subject to the provisions of Public Law 96-517 (35 USC 202) in which the Contractor has elected to retain title.
BACKGROUND OF THE INVENTION
Microshells of a diameter less than five milimeters can be formed by flowing a material in a molten state through an outer nozzle and another fluid such as gas through an inner nozzle to form a gas-filled pipe that breaks off into gas-filled shells. The shells fall into the top of a drop tower along which they are cooled to a solid state. If the shells are cooled rapidly, then the outside of the shell will not be precisely spherical, but will have a wavey surface. On the other hand, if the shell is cooled slowly, then the gas bubble within the shell will be off center.
One way to heat the shell material and the container and nozzle through which it passes, is by a resistance heater, either to heat the material to its molten temperature or to maintain it and the container at that temperature during shell formation. It is found that for high temperature-melting material, that the material tends to form unwanted lumps or particles of material. Also, microbubbles of gas in the material tend to coelesce to form bubbles of sufficient size to detract from the final spheres. A method for producing fluid-filled spheres which produced spheres with precisely spherical surfaces and gas bubbles that were precisely centered within the shell, and which avoided blockages of the nozzles by unwanted particles in the molten material which flows through the nozzles, would be of considerable value.
SUMMARY OF THE INVENTION
In accordance with one embodiment of the present invention, a method and apparatus are provided for forming accurately spherical and centered fluid-filled shells. One system includes a container with outer and inner nozzles through which molten liquid and a fluid such as gas pass to form a hollow extrusion that forms multiple molten shells. The molten shells drop into the top of a drop tower along which they are cooled to a state at which the shell is hard. The upper portion of the tower is heated to cool the molten shells at a relatively slow rate, to thereby provide time for dissipation of surface waves while the shell cools to a highly viscous state, or slightly above the melting temperature. The rest of the tower can be cooled to cool the viscous shell to a hardened state.
The shells can be initially formed by placing solid material into a container and then rapidly heating the material to its molten temperature in a period of less than 15 minutes even for material of a refractory-type melting temperature of over 1500° C. to minimize recrystallization and possible forming of unwanted gas bubbles. A molten material passes through a filter to block unwanted impurities such as oxides, and then into the other nozzle. The outer nozzle is formed in the bottom wall of a container that has integral bottom and side walls, so that the walls of the nozzle are integral with the container, to thereby avoid warping during heating from room temperature to a highly elevated temperature.
The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of apparatus for forming fluid-filled shells constructed in accordance with the present invention.
FIG. 2 is a view taken on the line 2--2 of FIG. 1.
FIG. 3 is a sectional side view, not to scale, of a system which includes the apparatus of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a microshell generator 10 which is used to form fluid-filled shells of at least a moderately high melting temperature material, that is, of a material that does not become molten ("molten" is herein defined as a viscosity less than about 10 poise) until it is heated to a temperature of more than about 1000° F. (537° C.). The generator includes a container 12 for holding a molten shell-forming material 14 which is forced out of an outer nozzle 16. The generator also includes a gas conduit 18 leading to an inner nozzle 20 that lies within an outer nozzle, and through which gas 21 is forced. The flowing molten material and gas form a gas-filled extrusion 22 that breaks up into individual gas-filled shells 24.
As shown in FIG. 3, an entire apparatus for generating shells 26 includes a drop tower 28 along which a shell 24 falls and along which it is cooled so that hardened shells 24H can be collected at the bottom of the tower.
It is found that when shells of high temperature (e.g. over 1000° F.) material are dropped in a molten state through a drop tower, which may be cooled along some or all of its height, the shells do not have a precisely spherical outer surface. Instead, the outer surface has ripples. Applicant has surmised that such ripples are caused by surface waves generated at the time when the molten shell 24 in FIG. 1 separates from the extrusion 22 passing out of the upper nozzle. If the molten shell is cooled very quickly, then it will reach a high viscosity (for glass) or harden, before the surface waves have dissipated, and the surface waves will appear in the hardened shell. For shells formed of relatively low melting temperature material (considerably below 1000° F.)) the difference in temperature between a molten shell and a drop tower at ambient temperature (72° F.) is not very great. Accordingly, the shell may cool slowly enough so that the surface waves will diminish by the time the shell has become highly viscous or hardened. As a result, surface waves do not appear in the outer surface of the shell.
Applicant avoids undulations in the outer surface of each microshell that is formed of high melting temperature material by heating the upper portion 30 of the drop tower 30, as by a clamp shell heater 31. Applicant heats the upper portion 30 of the tower to a temperature slightly below the liquid or melting temperature of the shell material. (at least one-half the temperature above ambient at which the material becomes molten). The heated portion 30 has a length of about 5 feet. When shells of a diameter no more than about one centimeter, and preferably no more than 0.5 centimeter, of high melting temperature materials are dropped through the tower which has a heated upper portion, there is sufficiently slow cooling of the shells so that the surface waves have dissipated by the time the shell has cooled to a temperature at which it has just about hardened.
The length of the heated upper portion 30 of the tower must not be too great, or else the gas bubble within each shell will become uncentered. The gas bubble tends to be centered in the heated upper portion of the tower, so the walls of the shell are of uniform thickness, by reason of an inherent normal mode oscillation and because of surface tension. If a molten shell is under zero gravity, which occurs when the shell is in free fall (without high wind resistance which prevents its continued acceleration by gravity), the gas bubble will become precisely centered within the shell. It may be noted that the drawings do not show any acoustic waves applied to the molten shell to break up the extrusion 22. During the first several feet of shell fall, the shell is not moving so fast that it experiences any significant wind resistance, and therefore the shell experiences no more than about one-tenth its weight and the bubble will remain centered within the shell. However, as the downward descent of the shell continues, and the shell velocity increases, the increased wind resistance prevents continued acceleration of the shell under the force of gravity. The gravity force then experienced by the shell increases towards 1G (1G is the force per unit mass on an object at the earth's surface which is stationary). It is therefore important to cool the shell to a temperature at which it is highly viscous or just about the melting temperature (at least about 10 poise) before the shell is moving down at a considerable speed such as more than about 16 feet per second, to prevent decentering of the gas bubble. All but the very smallest shells (e.g. below about 0.05 milimeter) will accelerate to a speed of about 16 feet per second during a time of about 1/2 second during which it falls a distance of about five feet, in a tower having a gas pressure on the order of one atmosphere. Accordingly, the heated upper portion 30 of the tower has a height about five feet (below the nozzle tip), to avoid surface waves and to avoid decentering of the bubble within the shell.
The lower portion 32 of the drop tower is preferably cooled significantly below ambient temperature, that is, cooled to at least 20° C. below ambient temperature (72° F. or 22° C.). This permits cooling of a shell of high melting temperature material to its hardened state during its fall through a drop tower of reasonable height, such as a total height of about 45 feet. Applicant maintains an atmosphere 34 within a drop tower of 45 feet height, wherein the atmosphere 34 is composed of helium gas at a pressure of about 170 rds that of atmospheric. The helium gas is cooled to a temperature of about -195° C. by liquid nitrogen and is flowed upwardly from a source 36 into a lower portion of the tower, to a vent 38 which is located a short distance below the heated upper portion 30 of the tower.
The container 12 of the microshell generator of FIG. 1 includes integral bottom and side walls 40, 42. The walls forming the outer nozzle 16 are integral with the bottom wall 40. By integral, it is meant that the walls of the nozzle are formed from the same block of material as the bottom and side walls of the container, without any bonding agent between them (which could fail at elevated temperatures and without any press fit which would produce stresses). By making the outer nozzle walls completely integral with the container, applicant avoids distortions of the outer nozzle, that arise when it is heated from room temperature to above 1000° F. Similarly, the walls of the inner nozzle 20 as well as the gas conduit 18 which passes through the molten material 14, are integral, to avoid twisting or other distortion caused during heating.
Applicant forms shells by removing a cover 44 on the container and placing one or more solid pieces of a high melting temperature material in the container 12. Applicant then later purges the atmosphere in the top of the container by passing helium gas into an intake 46 and out through a vent 48. The material is heated to a temperature above 1000° F. at which it is molten. It would be a simple matter to heat the container and its contents by resistance heating. However, because of the high temperatures involved, it requires considerable time for resistance heating. For very high melting temperatures of over 1500° C., it requires several hours to resistance heat a material from ambient temperature to perhaps 1500° C. If material is slowly heated past its melting temperature, recrystallization occurs. Recrystallization can result in the release and merging of gas, and the consequent formation of many tiny bubbles of various gases, the merged bubbles being of sufficient size to form substantial defects in the formed shells. Applicant minimizes the creation of such impurities of particles, by heating the very high temperature melting material rapidly. This is accomplished by induction heating, wherein large rapaidly varying currents are passed through a coil 50, to induce currents in a metallic material therewithin, which may be the shell material being heated, the container 12 or both. Since recrystallization occurs when heating of a material from ambient temperature lasts for about 30 minutes, applicant heats the material from about ambient temperature to its molten temperature of at least about 1500° C. in a few minutes, and in any case during a period of less than 15 minutes.
The molten shell material 14 is pressurized by pressured gas applied at the inlet 46, to push the molten material eventually through the outer nozzles 16. Applicant uses a filter 52 formed of multiple ceramic granuals or monolithic porous structures of other suitable materials, to filter out any undesireable particles and impurities. The pressured molten shell material 14 flows through flow channels 54 of a spacer 56 and into the outer nozzle.
The tip 20T of the inner nozzle is spaced behind the tip of the outer nozzle 16 by more than twice the diameter of the outer nozzle. This avoids the need to construct a very thin tip at the inner nozzle and to place it accurately concentric with the outer nozzle. Instead, Bernoulli forces cause small diameter streams of fluid such as gases to self center themselves within a flowing stream of forming material within the outer nozzle.
Applicant has formed microshells of a variety of materials and sizes using apparatus of the type shown in the figures. In one example, chunks of lead borate glass were placed in the container 12 and the container was heated to a temperature of 1650° F. (900° C.) to melt the glass. Gas under a pressure of about 30 psi was applied to the intake 46 while the vent 48 was blocked, to press the molten glass through the filter and through the outer nozzle 16. Spring loaded holdowns 64 press the cover of the container firmly in place against the pressure of the gas. Nitrogen or helium gas from a source 66 flowed out of the inner nozzle. The nozzles were of a size to form microshells having an outer diameter of about 0.5 milimeter. In the drop tower (FIG. 3) the upper five feet were heated to a temperature of about 930° F. (500° C.). Thermocouples labelled "TC" monitor the temperature in the drop tower.
Thus, the invention provides a method and apparatus for generating microshells having accurately spherical outer surfaces and having inner gas or other liquid bubbles precisely centered with respect to the outer surface of the shell. The upper surface of the drop tower into which the molten shells drop, is heated to at least 400° C. above ambient temperature along a length on the order of five feet, to cool the molten shell slowly enough to enable dissipation of surface waves. Immediately after the surface ripples die down, the shell is rapidly solidified to prevent decentering of the gas bubble as the shell falls along a drop tower filled with gas. The apparatus for generating shells can include a hole forming the outer nozzle, with the walls of the outer nozzle integral with the entire bottom wall of the container, to prevent distortion during heating from ambient temperature to a high temperature at which the shell material is molten. Such heating preferably occurs rapidly, within less than 15 minutes, to avoid recrystallization and the generation of undesirable small bubbles.
Although particular embodiments of the invention have been described and illustrated herein, it is recognized that modifications and variations may readily occur to those skilled in the art. Consequently, it is intended that the claims be interpreted to cover such modifications and variations.
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A system is described for forming accurately spherical and centered fluid-filled shells, especially of high melting temperature material. Material which is to form the shells is placed in a solid form in a container, and the material is rapidly heated to a molten temperature to avoid recrystallization and the possible generation of unwanted microbubbles in the melt. Immediately after the molten shells are formed, they drop through a drop tower whose upper end is heated along a distance of at least one foot to provide time for dissipation of surface waves on the shells while they cool to a highly viscous, or just above melting temperature so that the bubble within the shell will not rise and become off centered. The rest of the tower is cryogenically cooled to cool the shell to a solid state.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the art of operating cells that are used for the electrolysis of brine to produce chlorine and caustic, and in particular to such cells wherein a diaphragm divides the cell into anolyte and catholyte portions, with the diaphragm being of relatively hydrophobic material such as highly crystalline polytetrafluoroethylene. It concerns a method of re-wetting the diaphragm so that flow therethrough may be re-established at a desired greater value.
2. Description of the Prior Art
The operation of diaphragm-type electrolytic cells to produce caustic and chlorine is well known to those skilled in the art. Though it has been usual to use asbestos for the diaphragms of such cells, there has recently been a trend to change to different diaphragm materials, such as crystalline polytetrafluoroethylene, because of the considerable occupational-hazard problems encountered in the manufacture of asbestos and the expense of meeting them. The crystalline polytetrafluoroethylene material is quite satisfactory as a diaphragm material, except for its drawback of being rather hydrophobic and consequently tending to dewet while in service. When the diaphragm dewets, flow of material through the diaphragm slows down greatly or even substantially stops. It has often been necessary to halt the electrolysis operation when this happens and possibly also disassemble the cell in order to take appropriate steps to bring the diaphragm back into service.
In the operation of a diaphragm cell, the efficiency of the entire operation is importantly affected by the flow of liquid through the diaphragm. The brine can be supplied to the anolyte chamber only at a rate such that, considering the flow through the diaphragm, the level in the anolyte chamber remains at a tolerable level. It is usual for a diaphragm to begin to be somewhat slow in passing liquid after some days or weeks of service. Diaphragms of polytetrafluoroethylene sometimes pass liquid too slowly even at the start-up of an electrolysis operation because they have become partially dewetted before the electrolysis begins.
Many wetting agents are known, but most of them are not at all satisfactory for use in connection with a cell for the electrolysis of brine to produce caustic and chlorine. The usual nonionic wetting agents (ones of the propylene oxide-ethylene oxide type) are substantially unstable or insoluble in alkaline media.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention comprises the improvement, in a process of electrolyzing an aqueous solution of alkali-metal halide in a cell having a porous and hydrophobic diaphragm between the anolyte and catholyte compartments of said cell, which consists in adding to brine fed to said cell an amount of C 8 to C 14 alkyl glycoside, preferably decyl glycoside, effective to cause wetting of said diaphragm. Most usually the alkali-metal halide is sodium chloride. Concentrations of C 8 to C 14 alkyl glycoside on the order of 50 to 2000 parts per million in the brine are effective. The invention is of particular usefulness in connection with the use of diaphragms of highly crystalline polytetrafluoroethylene, such as a material commercially available for use as electrolysis-cell diaphragms which is sold by W. L. Gore and Associates, Inc., Elkton, Maryland, under the trademark "GORE-TEX".
Suitable alkyl glycoside compositions may be prepared in various ways well known to those skilled in the chemistry of carbohydrate derivatives. Adequate directions for the preparation of a suitable decyl glycoside appear in U.S. Pat. No. 3,772,269. We have obtained suitable results by reacting cornstarch, first, with propylene glycol and then with n-decanol under conditions that yield a product which consists mainly of decyl glucoside, i.e., a product having an average of about one anhydroglucose unit (AGU) per molecule.
Experiments with a laboratory-scale electrolysis cell having a diaphragm with an area of 116 square centimeters have been performed. Under usual conditions, when such equipment is operating satisfactorily, the rate of flow of electrolyte through the diaphragm is on the order of 6 to 12 milliliters per minute. If the diaphragm becomes dewetted or plugged, the rate of flow decreases to 2 milliliters per minute or less. We have found that additions of decyl glycoside to the brine may be used to restore the desired greater flow rates, permitting the in situ re-wetting of the diaphragm and saving the labor and expense which attend a re-wetting of the diaphragm by methods previously known, which necessarily involve disassembling and re-assembling the electrolysis cell.
The invention is illustrated by the following specific Examples.
EXAMPLE I
A highly crystalline polytetrafluoroethylene diaphragm having an area of 116 square centimeters was wetted with an acetone solution containing one percent by weight of a polyglycol nonionic surfactant, and then put into service in a diaphragm-type chlor-alkali electrolysis cell. An initial flow rate through the diaphragm of 2.3 milliliters per minute was observed. Inasmuch as such flow rate was substantially less than the flow rate ordinarily obtained with diaphragms of similar dimensions freshly installed in the same equipment, it was deduced that the diaphragm inadvertently become dewetted. Addition of 1000 parts per million of decyl glycoside to the brine had the effect, within one hour, of raising the flow rate through the diaphragm to 6.5 milliliters per minute, which value was thereafter maintained.
EXAMPLE II
A chlor-alkali cell for the electrolysis of brine was operated with a diaphragm of highly crystalline polytetrafluoroethylene having an area of 116 square centimeters for a period of three days under conditions usual for such cell, i.e., 50 percent salt cut, 75 millimeters head, and current efficiency of 87 percent. The diaphragm of the cell became dewetted, as was apparent from (1) the increase in the voltage required in order to maintain the desired current density from an initial 4.6 volts to 10 volts and (2) the decrease in the flow of brine through the diaphragm from a normal value of about 6.5 milliliters per minute or more to a low value, i.e., 1.6 milliliters per minute, even though the head had been increased to 450 millimeters. Decyl glycoside was added to the anolyte-5 milliliters of a solution of 10 weight percent of decyl glycoside dissolved in saturated brine. This made the concentration of decyl glycoside in the brine of the anolyte approximately 1250 parts per million. A remarkable improvement in the operation of the cell was obtained; within 45 minutes, the flow rate through the diaphragm rose to about 7 milliliters per minute and then remained at such higher value for approximately 1 hour and 15 minutes. Thereafter, however, over the course of the next hour, the flow rate decreased to less than 3 milliliters per minute. A second addition of decyl glycoside (also 5 milliliters) was then made. Within 15 minutes the flow rate through the diaphragm rose to over 8 milliliters per minute and remained at such value or higher for at least 2.5 hours.
EXAMPLE III
A laboratory-scale diaphragm-type chlor-alkali electrolysis cell was being operated with a diaphragm of highly crystalline polytetrafluoroethylene. The cell was permitted to operate over a weekend, and on Monday morning, it was discovered that the flow rate through the diaphragm had decreased to nil. There was then made an addition to the anolyte of 0.4 milliliter of the same solution as that used in Example II, i.e., a solution prepared by diluting 20 milliliters of an aqueous solution containing 50 weight percent of decyl glycoside with saturated brine to obtain a total volume of 100 milliliters, thereby obtaining a solution of 10 weight percent of decyl glycoside. Addition of 0.4 milliliter of such solution to the anolyte made the concentration of decyl glycoside in the anolyte 100 parts per million. Almost immediately there was a resumption of substantial flow of electrolyte through the diaphragm. Within half a minute, the flow rate increased to 8 milliliters per minute, and it later increased to between 10 and 11 milliliters per minute and remained at such value for a substantial period of time.
While we have shown and described herein certain embodiments of our invention, we intend to cover as well any change or modification therein which may be made without departing from its spirit and scope.
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By adding to the anolyte of an alkali-brine electrolysis cell of the kind that has a diaphragm of relatively hydrophobic material such as polytetrafluoroethylene, a small quantity of C 8 to C 14 alkyl glycoside, the wetting performance of said anolyte is much improved, and in some instances, good flow of anolyte through the diaphragm is readily re-established, without need for dismantling the cell to re-wet the diaphragm.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser. No. 11/083,909, filed Mar. 18, 2005 and entitled “Solar Powered Radio Frequency Device Within an Energy Sensor System”, which claims the benefit of U.S. Provisional Application No. 60/554,188, filed Mar. 18, 2004 and entitled “A Non-Intrusive Energy Sensor with Wireless Communications”. This application is also a continuation-in-part of U.S. patent application Ser. No. 10/892,837, now U.S. Pat. No. 7,089,089 entitled “Methods and Apparatus for Retrieving Energy Readings from an Energy Monitoring Device” and filed Jul. 16, 2004, which claims the benefit of U.S. Provisional Application No. 60/488,700 filed Jul. 18, 2003 and entitled “A Wireless Communication Network and RF Devices for Non-Intrusive Energy Monitoring and Control.” This application is also related to U.S. patent application Ser. No. 11/122,411 entitled “Grouping Mesh Clusters” and filed the same day as the present application. The foregoing applications are incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
The Field of the Invention
In facilities, e.g. buildings or installations, where a significant amount of power is used among a variety of units, it would be desirable to allow the building owner to allocate energy costs to the different units, i.e. consumers, within the facility. For a commercial office building, these units may include the different tenants within the building or the common loads for the facility, such as the elevators or HVAC systems. For an industrial facility, these units may include the different production lines, machines or processes within the facility. As opposed to allocating costs based on a fixed or formulaic approach (such as pro-rata, e.g. dollars per square foot or based on the theoretical consumption of a process/machine), an allocation based on actual measurements using appropriate monitoring devices may result in more accurate and useful information as well as a more equitable cost distribution.
Both installation and ongoing, i.e. operational and maintenance, costs for these monitoring devices are important considerations in deciding whether a monitoring system is worth the investment. While monitoring devices may be read manually, which does not increase the installation cost, manual data collection may increase on-going/operational costs. Alternatively, monitoring devices may be interconnected and be automatically read via a communications link. However, typical communication links require wiring to interconnect the devices which increases the installation cost. In addition, a particular tenant in the building may wish to verify that they are being billed correctly by reading the energy meter or other energy monitoring device that is accumulating their energy usage. This may be a straightforward, although labor intensive and cumbersome, process with a typical energy meter which provides a display viewable by the tenant.
Emerging wireless mesh (or ad-hoc) networking technologies can be used to reduce the installation costs of monitoring devices while providing for automated data collection. Also called mesh topology or a mesh network, mesh is a network topology in which devices are connected with many redundant interconnections between network nodes. Effectively, each network node acts as a repeater/router with respect to received communications where the device is not the intended recipient in order to facilitate communications between devices across the network. Using wireless interconnections permits simpler and cost-effective implementation of mesh topologies wherein each device is a node and wirelessly interconnects with at least some of the other devices within its proximity using RF based links. Mesh networking technologies generally fall into two categories: high-speed, high bandwidth; and low speed, low bandwidth, low power. The first category of devices is typically more complex and costly than the second. Since energy monitoring does not typically require high speed/high bandwidth communication, the second category of devices is often sufficient in terms of data throughput.
Energy monitoring devices may include electrical energy meters that measure at least one of kWh, kVAh, kVARh, kW demand, kVA demand, kVAR demand, voltage, current, etc. Energy monitoring devices may also include devices that measure the consumption of water, air, gas and/or steam.
Poor data integrity may manifest itself as poor data quality. Poor data quality may restrict the ability to execute business plans and may cost organizations money. Poor data quality may manifest itself in a failure of analytics and a failure in business initiatives. Analytic systems that do not implement at least some data quality mechanisms may suffer from limited acceptance or failure due to the lack attention to data quality issues. A Global Data Management Survey by Pricewaterhousecoopers in 2001 recorded the 75% of enterprises reported significant problems as a result of data quality issues. More than 50% had incurred extra costs due to the need for internal reconciliation, 33% had been forced to delay or scrap new systems, 33% had failed to bill or collect receivables. 20% had failed to meet a contractual or service level agreement. As analytical systems begin to be used on energy measurements, there is a significant need to ensure that there are data quality mechanisms to increase the level of data quality within an energy analytic system. In addition, there is a significant need to report the level of data quality within the energy analytic system.
Companies' reliance on data may be increasing sharply and irreversibly in the future as more ‘automated’ decisions may be based on data. This increases companies' exposure to bad data and raises a need for data integrity to be addressed in an energy analytic system. An analytic system that relies on historical data stores and real time data to present data, analysis, or report and perhaps automatic decisions may have a significantly reduced value if a data integrity quality system and analysis is not addressed within the analytic system. There is an increasing need to have data integrity issues addressed within an energy analytic system especially within a wireless mesh communication system.
BRIEF SUMMARY OF THE INVENTION
These and other limitations are overcome by embodiments of the invention, which relate to systems and methods for controlling or measuring data integrity in a mesh network. In one embodiment, a system for monitoring energy data that is representative of the energy from at least a point of an energy distribution system includes a wireless mesh network. A first radio frequency (“RF”) device operates to monitor energy at least at one point of the energy distribution system, construct energy data representative of at least a portion of the monitored energy, construct a communication packet containing the energy data, and transmit the communication packet on the wireless mesh network. A second RF device is coupled to the first RF device with a wireless link. The second RF device operates to receive the communication packet from the wireless mesh network and retransmit the communication packet over the wireless mesh network. The wireless link between the first RF device and the second RF device includes a data link. A data integrity function couples with at least one of the first and second RF devices, and operates to monitor data integrity of the energy data. The data integrity of the energy logs and communication system may be verified by using validation rules, estimation rules, editing rules and a data validation engine. The reporting of the data integrity may be facilitated by using a number of nines representation, alarm indications, signal to noise ratios and graphical depiction of the communication network with reliability indications. The data integrity of the logs within remote device may be preserved using a lossy style of compression, removing interval data and storing the data within remote devices accessible by a data link. The communication packet typically contains a value representative of at least a portion of the energy data.
In another embodiment, a system for controlling data quality within an energy distribution system includes a mesh network having a first RF device and a second RF device. The first RF device and the second RF device are able to communicate over a plurality of wireless links. The system also includes a communication validation function coupled to the first RF device and the second RF device. The communication validation function operates to monitor the plurality of wireless links in order to facilitate the transmission of energy data on the mesh network by adjusting at least one of the first RF device, the second RF device, and the plurality of wireless links.
Additional features 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 the practice of the invention. The features and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
To further clarify the above and other advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
FIG. 1 depicts a system of energy sensors within a commercial building communicating over a wireless mesh network;
FIG. 2 depicts an embodiment of a communication diagram depicting mesh communication links;
FIG. 3 depicts an embodiment of a communication diagram depicting mesh communication links;
FIG. 4 depicts an embodiment of a communication diagram depicting mesh communication links;
FIG. 5 depicts some of the general components within an RF data communication packet payload;
FIG. 6 depicts an energy sensor equipped with various commissioning aids;
FIG. 7 depicts a block diagram of an energy sensor;
FIG. 8 depicts a block diagram of an energy sensor utilizing power derived from the measured energy signal to power the metering device; and,
FIG. 9 illustrates an exemplary flowchart for monitoring data quality for an energy management system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Herein, the phrase “coupled with” is defined to mean directly connected to or indirectly connected through one or more intermediate components. Such intermediate components may include hardware, communication and software-based components. Additional intermediate components may include electrical field coupled and magnetic field coupled components. The figures included in this document refer to various groups of items using a number prefix and a letter as a suffix, such as 120 a , 120 b , and 120 c . The number listed alone without the letter suffix refers to at least one of these items. An example of this is when a group of items such as the energy sensors 120 are referred to as energy sensors 120 , this is meant to refer at least one of the energy sensors 120 a , 120 b , 120 c , 120 d , 120 e , 120 f , 120 g , 120 h , or 120 i.
The integrity of data on an energy management system is important to the overall analysis and billing potential of the energy management system. Bad data integrity can lead to data quality issues. Data quality issues within an energy management system may cause incorrect billing, maintenance problems, distribution issues and electrical failure. There are at least three areas for improvement that a data integrity function can assist with data quality issues within an energy management system. These three areas include ensuring a reliable communication network, preserving data during a network outage, and validating data. A data integrity function is a measure or control of data quality within a communication and analysis network. A data integrity function may include a system that may ensure a reliable communication network, a system that may preserve data during a communication network breakdown, or a system for validating, estimating, and editing data measured or received by a device or system.
Two of the benefits of data integrity system, ensuring reliable communication network and preserving data during a network outage, may be particularly of interest with a wireless network such as a wireless mesh network; however methods covering all three data integrity methods are disclosed within this document.
The present embodiments reduce the costs of energy metering by reducing the installation costs and commissioning costs for metering points. In addition, the present embodiments reduce the need for additional external components such as potential transformers, current transformers, and measurement cabinets. The present embodiments are able to reduce these costs by using various combinations of the following technology discussed below. By reducing these costs, the number of metering points within an energy distribution system, such as an electrical energy distribution system, may be increased; similar approaches may be used to increase the number of metering points throughout other energy distribution systems such as water, air, gas and steam distribution systems.
Referring now to FIG. 1 , a wireless network composed of a radio frequency (“RF”) repeater converter 110 , RF repeater 115 , and energy sensors 120 are used to transmit communication data packets between the energy management station 100 and the energy sensors 120 . As shown in FIG. 1 , this wireless network may be deployed within a commercial building space. An RF device includes at least one of RF repeater converter 110 , RF repeater 115 , energy sensors 120 , RF signal strength sensors, or RF display devices 140 . The RF devices make use of an RF mesh network for communication. Using RF communications, the present embodiments may be able to reduce the cost of metering an additional point or to reduce the cost of communicating an existing metering point in an energy distribution system back to the energy management station 100 or SCADA software by significantly reducing the cost of making communication wires available at the metering point and maintaining the communication wires between the energy management station 100 and the metering point.
The energy management station 100 may be software residing on a computer or firmware residing on an intelligent electronic device (IED). The energy sensor 120 is an IED that is able to meter at least one energy related parameter and communicate over an RF mesh network. An energy sensor 120 may include various measurement coupling devices. This allows the energy sensor 120 to measure or couple with measurements of various forms of energy. An alternate embodiment of the energy sensor 120 may include a measurement coupling device such as a digital input used for a pulse counter used to read pulses. An example is shown in FIG. 1 , where an energy sensor 120 a is monitoring pulses from a flow meter 125 over a pulse connection. These pulses may originate from another energy meter that may measure water, air, gas, electrical or steam energy. An alternative embodiment may contain a measurement coupling device that directly couples with the energy being measured.
The energy management station 100 is coupled with a RF repeater converter 110 via the communication backbone 105 . The RF repeater converter 110 may allow the energy management station 100 to communicate over the network and receive data from the energy sensors 120 within the wireless network. The energy management station 100 may have a connection to a communication backbone 105 , such as an Ethernet Network, LAN or WAN, or to an alternative communication medium and may be able to communicate to the wireless network through a RF repeater converter 110 that is connected to an alternative medium, such as a satellite or telephone connection. The alternative communication medium or communication backbone can be composed of any communication channel such as a phone network, Ethernet, intranet, Internet, satellite, or microwave medium.
In FIG. 1 , the wireless communication paths 150 represent some of the possible wireless communication paths possible between the RF devices. The wireless network technology used is an adhoc wireless mesh network technology. An adhoc network may have no infrastructure or may comprise an unplanned infrastructure. The adhoc network allows for a communication network to be setup while careful infrastructure planning in advance is typically required with communication networks such as wired Ethernet networks. A mesh network is a network that may contain multiple paths to communicate information. A mesh network comprises a number of RF devices. Typically each RF device is capable of receiving messages from other RF devices and that RF device retransmitting the message onto the mesh network.
An example of this is shown in FIG. 1 , where the energy sensor 120 e may transmit a message or communication packet(s) 1000 containing an energy measurement it has taken to the intended recipient the energy management station 100 . The initial transmission from sensor 120 e may only be received by the RF devices within transmission range of sensor 120 e . The communication packet 1000 may contain transmission route information 1020 such as how many hops, or direct device to device communication transfers, between RF devices were required last time a message was sent or received from energy management station 100 . If another RF device, such as energy sensor 120 g , receives the message from energy sensor 120 e , it may be able to compare the number of hops the transmissions usually take to be received by the destination and compare this to the number of hops indicated in the communication packet 1000 and determine if it should retransmit the message based on a reduction in the number of hops required from the transmission. The same evaluation process may be carried out by other communication indicators such as a measure of signal to noise ratio or a measure of success rate. In the above example, energy sensor 120 d would determine that it is one hop closer to the energy management station 100 and retransmit the communication packet 1000 . The energy sensor 120 d may add it's route information such as how many hops between other RF devices where required last time a message was sent or received from energy management station 100 to itself. Further, storing and evaluating the route information allows the RF devices and the mesh network system to monitor and react to the communications efficiency of data communications.
RF devices such as RF repeater converters 110 , RF repeaters 115 , energy sensors 120 , and RF display devices 140 that use the adhoc wireless mesh networking technology may be automatically recognized by the other RF devices within communication range. These additional RF devices can be used to extend the wireless network range, bandwidth, throughput, and robustness. For example, if an energy sensor 120 i is installed in an area that is not currently within the range of the mesh network, the installer need only add at least one appropriate RF repeater 115 to extend the range of the mesh network. In another example, the system may be designed with a second RF repeater 115 b that overlaps some of the service area of the first RF repeater 115 a , in this scenario the energy sensor 120 i that is in the overlapped area has at least two different communication paths back to the energy management station 100 . This increases the robustness of the system in that if the first RF repeater is damaged or is temporarily blocked due to RF noise, the energy sensor 120 may still be able to communicate via the second RF repeater 115 . The mesh network can be made secure such that additional RF devices must be either secured to the network or contain a security key that is accepted by an authentication device within the network. The communication security may comprise a public and private key system where the encrypted or signed data and the public key are transmitted on the RF mesh network.
The RF devices may be able to automatically modify their RF transmission power to only be as strong as required to reach an RF repeater or other RF device in the mesh network with adequate signal to noise ratio (SNR). This adjustment of RF transmission power may be referred to as a RF power control. For example, the microprocessor 825 (see FIG. 7 ) within the RF device may slowly increase power until at least one RF device closer to the target, for instance the energy management station 100 , successfully receives the message. Alternatively, when a communication packet 1000 is received from another RF device, that packet may contain the set transmission power of that RF Transceiver 875 . The transmission power information may be used by itself or with another measure such as signal to noise by the microprocessor 825 to determine the required RF transmission power of the RF Transceiver 875 .
Another example of microprocessor 825 controlling the RF transmission power of the RF Transceiver 875 may occur if a transmission is sent from the source RF device and is picked up by at least two separate RF devices. The source RF device may receive the communication packet as retransmitted by both RF device and may either modify the next communication packet so that it is not repeated by one of the devices or modify the transmission power of its RF transceiver 875 so that only one RF device is within RF range of the transmission. This has an added benefit of reducing the range of the RF transmission zones to increase security as well as reduce the power requirement of the RF repeater. If the RF device that transmits the communication packet does not receive confirmation of successful transmission or does not see the packet retransmitted from another RF device, the transmitting RF device may increase the transmission power in an attempt to reach another RF device within the mesh wireless network.
The RF device's control over the RF transmission power may be used to create mesh zones. An RF zone may be used if a number of RF devices are within communication range of each other but by limiting their RF transmission power they would limit their range of their RF transmissions to be within a RF zone. At least one of the RF devices participating within this RF zone would act as a repeater or gateway to the rest of the mesh network. The RF device may be able to dynamically modify their RF transmission power depending on the communication packets intended destination or next intended hop to their destination.
As a result of the RF devices ability to modify their transmission range, the network security may be enhanced as RF power is set to a minimum required level. In addition, the RF devices power supply requirements are lowered.
The installation of mesh networks such as the energy sensor 120 or RF repeater 115 can be complicated by intermittent network connections due to marginal transmission and reception of data over the network. During the commissioning of the system, all that may normally be done is to verify that each RF device 120 may ultimately communication with the energy management system 100 . This verification simply tells the installer that the system is currently working properly, but it does not tell how much operating margin the radios have. For low cost devices, it is usually not feasible to include measurement of signal strength.
The operating conditions of a mesh network radio can change due to near body effects, temperature, interference, fading and multipaths. If RF device 120 reception is close to the operating limit of the radio, then small changes of the operating conditions can render a RF device 120 non-communicating, potentially resulting in one or more RF devices 120 no longer in communication to the energy management station 100 .
This disclosure proposes the use of a RF device 120 with a variable RF power to validate the correct operation of the system at a reduced RF power level. During commissioning the system is switched to lower power mode. The RF device 120 may have either or both a variable RF transmission power and a variable RF reception capability. Once the mesh network has been verified to be fully operational, the system is switched to operating mode. This verification may require the installation of appropriate RF repeater 115 or RF repeater converters 110 to complete the network. During normal operation the mesh network node power may be increased to a higher (normal) power level assuring that the reception and transmission of mesh network data is well above any marginal radio operating parameter. Alternatively, the power level may be allowed to be increased to the higher (normal) power level if the RF device is operable to automatically adjust it's transmission power during normal operation.
The RF repeaters 115 are used to receive and retransmit wireless packets between the energy sensors 120 and the energy management station 100 or between two RF devices. For example, the RF repeater 115 may facilitate communication between energy sensor 120 i and energy sensor 120 h or RF display device 140 . These RF repeaters 115 may be capable of performing routing of the wireless packet. These routing tables may be stored in the RF repeater in non-volatile memory so that after a power outage, network communication can quickly be restored. The RF devices may use a self-healing feature that makes use of a network architecture that can withstand a failure in at least one of its transmission paths such as a mesh or partially mesh network. The self-healing feature may allow an RF device to redirect a communication packet such as to avoid a nonfunctioning RF repeater 115 or RF device. In addition, the RF repeaters 115 may be able to determine if they are the final destination for a communication packet, decode the packet, and further carry out the instruction provided. This instruction can be the modification of a setup within the RF device, request to read a register, part of a firmware upgrade, communication acknowledgment, or an instruction to generate an alternate communication packet. At least a portion of the RF repeater 115 may be implemented within an ASIC chip.
The RF repeater converters 110 or gateway device 110 may be used to repeat the RF signals as necessary in a similar manner as the RF repeaters 115 . In some cases, the RF repeater 115 functionality may be left out of the RF repeater converters 110 to reduce cost; however, when the RF repeater converters 110 have this capability there can be an additional cost savings as the network is extended without the requirement of a RF repeater 115 . In addition, the RF repeater converters 110 may be operable to provide a bridge between the wireless mesh network and other communication devices such as a Ethernet backbone, power line carrier, phone network, internet, other wireless technologies, microwave, spread spectrum, etc. In addition, the RF repeater converters 110 may be able to determine if they are the final destination for a communication packet, decode the packet, and further carry out the instruction provided. This instruction can be the modification of a setup within the RF device, part of a firmware upgrade, communication acknowledgment, or an instruction to generate an alternate communication packet. At least a portion of the RF repeater converter 110 may be implemented within an ASIC chip.
The energy sensors 120 may be capable of repeating the RF signals in the same way as the RF repeaters 115 . In some cases, the RF repeater 115 functionality may be left out of the energy sensor 120 to reduce cost; however, when the energy sensors 120 have this capability there can be an additional cost savings as the network is extended without the requirement of an RF repeater 115 . Energy sensors 120 that can act as RF repeaters 115 can increase the range and robustness of the network as well as reduce the number of components required to make up the wireless mesh network. The sensors 120 have the additional task of generating a communication data packet containing a measurement that they have taken or calculated. In addition, the energy sensor 120 may report the status of the energy sensor 120 . In addition, the energy sensors 120 may be able to determine if they are the final destination for a communication data packet, decode the packet, and further carry out the instruction provided. This instruction can be the modification of a setup within the energy sensor 120 , request to read a register, part of a firmware upgrade, communication acknowledgment, or an instruction to change an output or control a device. An energy sensor 120 is used to monitor or measure at least one energy parameter. This energy parameter may be monitored directly, indirectly or via another monitoring device such as an energy meter with a pulse output or an energy meter with a communication port. Alternately, the energy sensor 120 may monitor a parameter that has an effect on an energy distribution system such as temperature, vibration, noise, breaker closure, etc. At least a portion of the energy sensor 120 may be implemented within an ASIC chip.
The RF devices may include wireless RF display devices 140 . These RF display devices 140 may be mobile, mounted or adhered to the outside of a measurement cabinet. The RF display devices 140 may display readings or alarms from one or more energy sensors 120 . These energy sensors 120 may be within the measurement cabinet, in the vicinity of the RF display device 140 , or accessible via communications over the RF network. The display devices 140 may contain user interfaces such as keypads, stylists or touch screens that allow access to various displays and quantities within the energy sensors. The RF display device 140 may be mobile and used to communicate to more than one energy sensor 120 . Alternatively, the RF display device 140 may communicate to the energy management station 100 and display information or alarms from the energy management station 100 . In addition, these RF display devices 140 are able to correlate various readings from different energy sensors 120 or specified values, perform calculations and display various parameters or derivations of parameters from the energy sensors 120 they have access to the wireless mesh network. For example, if an IED 135 is able to measure the voltage on the bus or the voltage is a specified constant and the expected power factor is supplied, the RF display device 140 is able to correlate the values and calculate various energy parameters, such as kVA, kVAR and kW with at least usable accuracy, and display them on the screen or log them into memory. A permanently or semi-permanently mounted RF display device 140 may be usable as active RF repeater 115 to boost the RF signals from sensors within a measurement cabinet or within the vicinity of the RF display device 140 . At least a portion of the RF display device 140 may be implemented within an ASIC chip.
The energy sensors 120 are able to take a measurement directly and provide the data wirelessly to the energy management station 100 via the RF repeaters 115 and RF repeater converters 110 . Alternatively, the energy sensors 120 or other RF devices can be built into the IED 135 directly such as represented with IED 135 . In this example, the energy sensor 120 b and energy sensor 120 c may communicate to the energy management station 100 through a RF gateway integrated into IED 135 which is connected to communication backbone 105 . Depending on the integration of the RF device within the IED 135 , the RF device may be able perform IED setup, modification to registers, firmware upgrade and control of the IED 135 . In an alternate configuration, a RF repeater converter 110 may be connected to a communication port such as a RS232 port on the IED 135 . For example, the communication port 870 may be wired directly to a RS 232, RS 485, universal serial bus (“USB”) or Ethernet port on the IED 135 . The RF device, such as the repeater converter 110 , may be operable to receive wireless communication over the mesh network and if that communication is addressed to an IED 135 connected to the RF device, the RF device would provide the information to the IED 135 over the communication port 870 . Further, if the IED 135 sent a message or a response to a message received over the RF device, the RF device may be able to transmit the message onto the wireless mesh network. This effectively would enable a legacy IED 135 , an IED 135 device without RF wireless communications, to send and receive packets over the wireless mesh network, using the RF device to send and receive communication packets. The RF device acting as this interface may modify the communication packets to change protocol or add routing information. The RF device may act as a data concentrator where the energy data may be manipulated before transmission such as receiving voltage data from one sensor and current data from another sensor and combining such data. More than one legacy device or IED 135 may be connected to the communication port. This may be complete using more than one communication channel for example two RS 232 interfaces or using an interface such as RS 485 that allows more than one device sharing one communication channel. For example, if there were a number of IEDs connected over RS 485, the RF device would be able to coordinate communication to each individual IED on the RS 485 communication line. Alternatively, there may be a more direct coupling between the two communication ports.
Further, the RF repeater converter 110 may be able to draw power from the communication port of the device to power itself and provide full communication to the device over the wireless mesh network. Three examples of the power available from a communication port are power provided by a USB communication port, power over Ethernet, or parasitic power drawn from an RS-232 port. Alternatively, the RF repeater converter 110 can be powered from an external power source or powered by an alternative power source described later on in this document.
An RF device 200 may be powered by an intermittent or non-reliable power supply such as a solar panel. The above power sources may be intermittent or have periods of being unable to produce enough power for the RF device. The present embodiments may make use of a super capacitor to store the power when it is available and allows for short higher power draws for the RF device. For example, an RF repeater 115 can sit in a low power listening mode, when it receives a packet, the power requirement may increase for the device and finally if the RF repeater is required to retransmit the particular packet, the power requirement will increase again to a sufficient level to transmit to the next RF device in the routing path. The super capacitor is able to store excess energy not required in the low power listening mode and provide extra energy as required in the higher power modes such as when the RF device is required to transmit information or when the microprocessor 825 in the RF device needs additional power to perform a quick, more complex calculation. Other energy storage devices 815 such as a rechargeable battery may be able to function similarly to the super capacitor. An alternative embodiment may be the use of a non-rechargeable battery that may be replaceable to supply any additional power requirements not supplied by the alternative power sources discussed in above in this document.
By using the super capacitor or battery to store energy, the RF devices are operable to transmit a message to the Energy Management Station 100 when the RF device's alternative power supply has diminished or has been removed. The RF devices can be setup with a tolerance threshold such that a momentary (user defined) time must elapse when the power supply is able to provide less power than set by an additional threshold or when the power is cut off entirely before the RF device transmits that power has been removed. This requirement of a passing of a user specified amount of time when the power supplied is less than a threshold reduces the network traffic of the mesh network due to a regular periodic outage that only lasts a short time is not reported.
Alternatively, the RF device can be configured to transmit a message saying that power is low within the device. One of the recipients of this type of message may be the energy management station 100 . This message may be sent when both the power supply and the reserved power held by the super capacitor or battery is running low and may indicate that either a better alternative power supply may be used or it may be necessary to charge the reserve power.
Both of the above messages, “power supply low or removed” and “power low within device”, can contain any child RF nodes that may lose communication to the rest of the RF mesh network due to the loss of the RF device that has an imminent power loss. Alternatively, this information may be determinable by the energy management station 100 .
The RF devices may use long life batteries to power the devices for an extended period of time. These batteries can be made of various technologies such as lithium-ion batteries that can last up to 10 years with a low power draw or other technologies that allow the batteries to have a long life. This solution can be used to give the installer one of the easiest RF devices 200 to install. The RF device 200 can simply be outfitted with a strong adhesive or a magnetic mount. For example, to extend the RF mesh network, the installer only has to take an RF repeater that uses a long life battery and simply stick or magnetically mount it in almost any location.
The RF devices, such as the repeater converters 110 or the repeaters 115 , can be built to fit general form factors, and able to draw power off of these standard form factors. For example, an RF device may be made to have a form factor with an interface to a general purpose outlet. This allows the RF mesh network to be extended to any location the repeater can be plugged into a general purpose outlet. Typically this form factor may have a general purpose outlet interface to allow another plug to be plugged into it. For example, if the general purpose outlet (GPO) was already being used, the RF repeater may fit between the GPO and the existing plug. Another similar example is building a repeater 115 into a form factor that may allow it to screw into a standard Edison light socket and allow the light bulb to screw into the repeater form factor. These implementations may use the appliance or light bulb as an RF antenna. Even though the Edison light socket may not always be powered on, when it is powered on the repeater may store energy in a super cap or rechargeable battery.
The RF devices may have a configurable setting that can indirectly determine what average power is required for the device to perform. For example on the energy sensors 120 , the user is able to modify sleep, transmit, and sample intervals. For instance, if the sample interval is increased from say a sample every 30 seconds to a sample every 1 minute, the energy sensor 120 is only required to take one reading each minute instead of two readings per minute which may reduce the power required to run the energy sensor 120 . This reduction in power may increase the battery life of an energy sensor 120 that relies on battery power. In addition, it may increase the ride through time of the energy sensor 120 if power supplied to the device were insufficient or removed. Further by modifying the transmit interval on an energy sensor 120 , the data the energy sensor 120 collected may be stored in the energy sensor 120 and only sent at a specific interval in order to send more data in each communication data packet but be able to transmit the data less often. For example, an energy sensor 120 that samples each minute may only transmit each hour thus significantly reducing the overall power required within an hour to transmit versus an energy sensor 120 that transmits sixty times in an hour. Likewise, a repeater 115 or repeater converter 110 may queue received communication data packets until a specified time interval or timeout has expired when all the data may be transmitted in one transmission. In addition, the RF devices may queue data until sufficient power is stored to allow transmission of the data and continued operation. The data queued within a RF device may be stored within non-volatile memory such that it is not lost due to a power failure. Alternatively, the data may be transferred into non-volatile memory before a power failure on the RF device.
An external power supply can be used to supply extra power allowing the RF device to charge the super cap or rechargeable battery. Typically this may be used either just before installation of the RF device or during commissioning to provide the extra power required to perform setup commands or to handle extra RF communication to set up the device. Alternatively, the external power supply may be used to charge the super capacitor during a period when the device has low power or when the device has indicated that it has low power. This external power supply is a device that is able to generate an electromagnetic field that in turn is used to power the RF device. This means that there is not a requirement for a direct physical connection. Using the electromagnetic field to charge the RF device has the advantage that there is no requirement for a conductive wire or pad on the RF device that may corrode over time. Alternatively the external power can be designed to directly couple to the device where there is a requirement for a physical connection. There may be communication between the RF device and the external power supply such that the external power supply may be able to indicate to the user the level of charge within the RF device.
The RF devices may contain non-volatile memory to store RF device configuration. This is to prevent loss of the configuration if power to the device is momentarily lost. In addition, the RF device may store at least a portion of the routing tables within non-volatile memory. This facilitates a fast network recovery if power is lost. For example, when an RF device powers up after a power down, it may know which RF repeater 115 or RF device to send communication packets to without the requirement of a broadcast packet or repeating a network routing table discovery phase.
A large cost associated with adding a metering point is the installation cost. Typically this installation cost comprises labor and material cost. There are a number of individual costs associated with installing a metering point in an energy distribution system. The RF devices may reduce or eliminate many of these costs and simplify the installation by using various form factors, powering methods, mounting techniques and installation methods. These methods are further discussed in the following paragraphs.
As discussed earlier, one of these costs is running communication wire to each IED 135 or energy sensor 120 . Often installation sites require that any run wire must be enclosed within a conduit. This significantly increases the cost of enabling communication in a device; however, communication is often important to an energy management system. The IEDs 135 and energy sensors 120 may use RF wireless mesh networks. A preferred embodiment is an RF wireless mesh network including of RF repeaters 115 and RF repeater converters 110 . In using this wireless network, communication wire need not be brought to each installation point. In fact, an energy management system that uses purely a wireless RF mesh network need not have any communication wire installed; however, in practice, communication wiring may be used in conjunction with a repeater converter 110 that facilitates communication between the traditional communication medium and the mesh network. One example where both communication wiring and RF wireless mesh networks may be used may be where there are existing wired communications perhaps to a substation. In this case, a repeater converter 110 may be connected to the existing wired communication and provide connection to the energy sensors 120 using wireless RF communication packets. In another case, a repeater converter 110 may be used in conjunction with a telephone, cellular, or satellite modem to provide a connection over a large distance to the RF mesh network of energy sensors 120 and other RF devices.
The physical installation of the energy sensor 120 or IED 135 is another significant installation cost. The physical installation typically requires creating a mounting hole or a method of securing the sensor to the measurement cabinet 200 b . In many cases, a hole must be cut in the measurement cabinet 200 b for the metering devices display to be mounted.
Additional physical installation costs for an energy sensor 120 or IED 135 installation are inserting the energy sensor 120 or IED 135 into the primary or secondary current loop which means using a CT shorting block or de-energizing the point in the electrical distribution system, breaking the secondary current loop, and adding the new device into the loop. There are significant wiring costs to connect the meter to the current transformer. Even with using a non-intrusive CT there is wiring that needs to be installed and worked around to connect the non-intrusive CT to the metering device during the installation process. In addition, connection must be made to the electrical bus or the potential transformer to measure voltage. In addition, it is often necessary to wire separate control power to the metering device.
The energy sensor 120 and RF devices may reduce these installation costs by using powering technologies already described. These powering technologies may not require a directly wired connection to an electrical power supply. In addition, the energy sensor may incorporate a non-intrusive current transformer (CT) as described in the following paragraphs so that the primary or secondary current loop need not be broken. Further, the energy sensor may incorporate a non-intrusive capacitive voltage detection as described later in the document.
The IED 135 and energy sensor 120 may incorporate a non-intrusive CT. This allows simple and inexpensive installation comprising the non-intrusive CT, which incorporates the sensor microprocessor and may incorporate the wireless communication hardware, is separated, slipped over the current carrying wire or fuse, and reconnected to form a CT core around the wire or fuse. FIG. 6 depicts an electrical energy sensor 500 comprised of sections 925 and 930 separated operable for a current carrying wire put inside the 925 section of the electrical energy sensor 500 . An electrical energy sensor 500 is an embodiment of the energy sensor 120 used for monitoring electrical energy parameters. The section 930 is coupled with section 925 to form a non-intrusive CT sensor. The electromagnetic field generated by the current carrying wire is captured by the CT and may be used to power the microprocessor in addition to allowing the current carried by the wire to be measured. The electrical energy sensor 500 may incorporate tabs 905 that may be bent when installing the sensor over a wire or a fuse. These plastic tabs are then able to hold onto the wire or fuse due to the friction and pressure created by inserting the wire into the electrical energy sensor 500 . As the electrical energy sensor 500 is able to hold its location on the current carrying wire or fuse, it is not required to mount the sensor to any location in the cabinet. In cases where it is desired to monitor two or more phases of current, the electrical energy sensors 500 may have wires that extend from them to one or more other non-intrusive CTs. Alternatively two or more separate electrical energy sensors 500 may be used where these two or more electrical energy sensors 500 communicate their reading wirelessly to a master electrical energy sensor 500 or alternatively to the energy management station or an additional RF device. It is possible for the master electrical energy sensor 500 , additional RF device, or the energy management station 100 to correlate these two or more readings.
Alternatively the form factor depicted in FIG. 6 may be used for a RF repeater 115 or RF repeater converter 110 . This form factor may allow for an easy method for extending the RF mesh network, as the form factor is able to draw power from the magnetic fields generated by the current carrying wire. This may allow for network range extension over large distances by installing this form factor RF repeater 115 or other RF device over electrical distribution wires. Alternatively, these repeaters may be able to act as RF repeaters 115 for communication, packets and frequencies from other RF systems. Some examples of these RF communications from other RF systems may include but not limited to cell phone frequencies, wireless Ethernet connections, and other radio frequency transmissions. Alternatively, a repeater converter 110 may be used in this form factor to detect power line carrier on the wire and be able to boost the signal, repeat the signal or convert the power line carrier to another communication medium such as the wireless mesh network.
Alternatively, the energy sensor 120 or the electrical energy sensor 500 may be manufactured to fit over a standard high rupturing capacity (HRC) fuse or other type of fuse. The energy sensors 120 may be able to use the fuse resistance to monitor the current flowing through the fuse by compensating for fuse resistance over current and temperature ranges. Alternatively, the energy sensors 120 may incorporate a non-intrusive CT to measure the current flowing through the fuse element. The energy sensors 120 can monitor parameters of the fuse, such as the various levels of current and temperature over time, to determine when the fuse needs to be replaced and the energy sensors 120 may be able to predict fuse failure and transmit fuse failure information over the RF network.
Another embodiment of the energy sensor 120 is incorporating the energy sensor 120 into a breaker. In this case, the breaker has an integrated energy sensor 120 with wireless communications. The wireless communications used in the present embodiments may form a wireless RF mesh network.
Alternative embodiments are building the RF device, such as the energy sensor 120 or RF repeater 115 , into a power bar, outlet box, general purpose standard outlet, or Edison light socket. These embodiments have the advantage of ease of installation and monitoring of a specific load.
As described above, a large cost of metering to certain points in an energy distribution system are running communication wires to each point; however, with the wireless mesh network used by the present embodiments only the wireless mesh network extends to the energy sensor 120 . Adding active RF repeaters 115 near the existing mesh network border extends the wireless mesh network. Alternatively using repeater converters 110 can extend the mesh network over existing communication means such as but not limited to a modem, Ethernet, telephone, satellite, spread spectrum, or RS485 communication methods. The RF repeaters are simple and inexpensive to install due to the power supply technology mentioned above in this document.
The RF devices may comprise an RF signal strength sensor. This RF signal strength sensor has an indication that measures the signal strength of the RF signal received from another device in the mesh network. In addition, it may indicate if an energy sensor mounted near the RF signal strength sensor may be able to communicate to the mesh network. This may include communication to the energy management station, an RF display device, or another RF device. This indication device may be incorporated within another RF device. This RF strength indication allows the installer or commissioning individual to determine where an RF repeater 115 needs to be installed to extend the network. The RF signal strength sensor may have the ability to indicate the number of independent paths from the current location to the energy management station or any specified location within the mesh network. Using this device, the installer may be able to determine the best locations for RF devices including energy sensors 120 , repeaters 115 , displays devices 140 , and repeater converters 110 as well as the best orientation for the RF device or RF antenna. This device may be used to troubleshoot or add additional routing paths to the network and overall increase the network reliability and robustness. At least a portion of the RF signal strength sensor detection circuit may be implemented within an ASIC chip.
The present embodiments' energy management station 100 , RF display device 140 , and RF signal strength sensor may have a user display that can show the RF routing paths available between various RF devices. This information can be coupled with the physical location of the device if it is known and the present embodiments are capable of showing the possible routing paths as well as indicating the strength of each RF link. The RF display device 140 , RF signal strength sensor and energy management station 100 may be able to analyze this data and indicate the best locations to add repeaters or sensors. Alternatively the installer or commissioner may be able to quickly pick out the best locations for an RF repeater 115 based on the presentation of the routing paths and signal strengths. For example, FIG. 1 is a representation that may be displayed to the installer. Each RF link 150 shown may include an indication of signal strength such as a number, symbol, bar indicators or colors that indicate the signal strength over the communication link 150 . In addition, a distance, signal to noise ratio, and error rate of the communication path may be calculated, stored in a database 103 , and shown on the diagram. The distance for a communication path may be determined by sending a small communication “distance ping” between two RF devices and determining the distance based on the time the distance ping was sent and received at a RF device, hardware delay, and speed of communication medium.
Reducing the initial commissioning cost and cost of commissioning errors reduces the overall total cost of ownership in metering a point on an energy distribution system. Typically commissioning costs of energy metering points are relatively high. Often there is a need to have a factory representative on site to fully commission a system. In addition, there can be errors that are difficult to correct if the incorrect settings are sent to the metering device. An example of a commissioning error occurs when an electrical monitoring device is set to an incorrect PT or CT ratio for electrical energy monitoring as incorrect primary measurements may be calculated from the secondary measurements. Another example may include setting up an incorrect value per pulse for the monitoring of a pulse output from another metering device. Additional commissioning costs include the manual setup for communication of monitoring devices with the SCADA software. Each metering point connected may have communications configured at the metering point as well as at the software system. Any error in these configurations at either site can result in no communications and may require troubleshooting which further increases commissioning cost. The RF devices may reduce or eliminate many of the costs resulting from the commissioning of an energy sensor 120 or communication device by using automatic device detection, communication configuration and logging of data as described below. In addition, the RF devices may contain automatic or at least partially automatic location methods when commissioning the metering point. These methods are described below.
Referring to FIG. 6 , the electrical energy sensors 500 may indicate the direction of energy flow in the wire 505 . The direction of energy flow is calculated from the phase detected of the current in the wire with the current CT and the phase of the voltage detected. The energy flow through the electrical energy sensor 500 may be used to indicate a supply or load of electrical energy through a metering point. A quick indication may be performed using two different color LEDs. For example, a red LED may indicate that the energy flow detected on the wire 505 corresponds to a generation or supply of power and the green LED corresponds to a load or demand of electrical power. The installer or commissioning of the electrical energy sensor 500 may be able to determine if the electrical energy sensor 500 is connected in the correct orientation on a wire 505 . For example, if the electrical energy sensor 500 is connected to a metering point that should register as a load and the LED illuminates indicating a supply or generation of power, the installer may reinstall the electrical energy sensor 500 the opposite orientation so that the flow of energy flows in the opposite direction through the electrical energy sensor 500 . Alternatively a single LED may be used to indicate energy flow direction through the electrical energy sensor 500 . This single LED may be able to indicate two different colors or simply indicate one of the two energy flow directions if illuminated and the opposite energy flow direction if not illuminated.
The RF devices and energy management station 100 may be operable to detect a new RF device when it is activated within the communication range of the mesh network. Using auto detection, the energy management station 100 may be able to auto configure all communication settings. In addition, the energy management station 100 and the RF devices may be able to automatically determine the routing method to use to communicate as well as alternate routing if available. As soon as the energy management station 100 has automatically detected and configured communication to the energy sensor 120 or IED 135 , it may be operable to start querying at least one reading or configuration setting of the RF device. These readings and configuration settings may be recorded in database 103 along with a device identification code. These recorded configuration settings may be used to detect configuration changes within the device or to assist in compensation for reading or displaying data recorded when incorrect configuration settings were used. The device identification code may be used to assist in locating the device within the energy distribution diagram or within a physical location. In addition, the energy management station 100 may allow a retroactive configuration change to be made. This means that if an error in the configuration of the RF device or energy sensor 120 is detected after some logging has taken place, the energy management station 100 may be able to calculate and correct logged parameters in the database 103 . Alternatively the energy management station 100 may be able to calculate corrected data and display this data to the user.
The energy management station 100 is coupled with a database 103 used to log data from the energy sensors 120 and energy information that may be at least partially derived from the data retrieved from the energy sensors 120 . The energy management station 100 may monitor and log the configuration and routing paths of the wireless network and any of the RF devices within the wireless network range. The energy management station 100 may be configured to auto detect any new repeater converter 110 , repeater 115 , sensor 120 , or RF display device 140 . When the energy management station 100 detects a new RF device, it may automatically add it to its routing table and determine which other RF devices are within range of the new RF device. The energy management station 100 may uses this information to modify the routing table to have more efficient communications. As cost may also be a factor within the network such as when there is a satellite, long distance carrier, or cellular phone connection within the routing, the energy management station 100 allows the operator to set an indicator representing the cost associated with certain communication links. The energy management station may be capable of trying to reduce costs in the communication routing by evaluating the cost of various paths. In addition, the energy management station 100 may be able to pick the most reliable and quickest routing path based on recorded history of alternate communication links. Alternatively at least a portion of the RF devices, contain routing intelligence and determine the best path for at least some of the communication. This may be done via a collaboration protocol or frequency between the RF devices. Using this auto-detect and auto configuration technology, the network is able to adapt to changes in the network such as new RF devices, failed RF devices, or inadequate power supply to an RF device.
An important process in commissioning is programming the location of the monitored devices into the energy management station 100 or the Supervisory Control and Data Acquisition (SCADA) software. Location of the energy sensor 120 may be the physical location or the point the energy sensor 120 is monitoring on an energy distribution network diagram (one line diagram). A one-line diagram is a standard term for a simple block diagram showing the energy distribution system. Alternatively, the physical location of the device may be preferred such as the building number, floor number, substation number, or geographic coordinates. Typically both the physical location and the point in the energy distribution system that the energy sensor 120 is monitoring are useful. It may also be useful to record the location of other RF devices within the communication network during commissioning. To reduce commissioning time and thereby reduce cost of ownership, the RF devices automate this process through various methods and alternatively provide some standardized record keeping for IED 135 and RF devices. The techniques used to automate and simplify the ability to locate RF devices, energy sensors 120 , and IED 135 are discussed below.
Referring now to FIG. 6 , a number of commissioning location devices are depicted. The RF devices, such as energy sensors 120 , and IED may contain an identification tag. This identification tag may be represented by a barcode number 615 or may be embedded in a MAC address, or comprise some other at least semi-unique identification code. The identification tag may be stored within the memory of the RF device and may be retrieved via communications to the RF device. For example, the energy management station 100 may be able to retrieve a RF device's identification tag over the mesh network. There are other alternatives that can be used as an identification device or method such as Radio frequency identification (RFID). For example, any string capable as being used as a unique or at least semi-unique electronic fingerprint such as a serial number or a MAC address may be used to uniquely identify one device out of a number of RF devices. This identification code may be present on a removable portion of the RF device such as a peal-off label 610 or a break-off label 605 . The identification code may be represented by a barcode 615 a on the break off tag 605 , a barcode 615 b on the peel off tag 610 , or on the RF device itself as a barcode 615 c . These labels may have an area 620 a or 620 b that can either be used for taking notes on the location of the RF device or required RF device settings. The information may be recorded in a manner that can be automatically read by the energy management station 100 such as a computer punch card or alternatively the energy management station 100 may be able to recognize symbols or handwriting in the area 620 a or 620 b . Information that may be recorded consists of items such as building, floor, bus, feeder etc. An example commissioning method using these break-off tags 605 or peal-off tags 610 consists of the energy sensor 120 or RF device being connected to a point in the energy distribution system, such as a current carrying wire, the commissioner of the RF device may break off a tag 605 or peel off a tag 610 and take notes on the tag in the areas 620 a or 620 b . Later at the energy management station 100 , the tag 605 or 610 is read into the energy management station 100 and any notes or RF device settings on the tag are either automatically read in or manually entered in. The energy management station 100 may be able to read the bar code 615 a or 615 b on the tag and match the settings or location to the RF device within the mesh network or communication ability of the energy management station 100 .
Referring to FIG. 6 , an optical port 625 is shown on the RF device or energy sensor 120 . A handheld computing device 635 , such as a WinCETM or PalmOSTM device, may be able to establish an IRDA or other type of optical communication link 630 via the optical port 645 to the RF device or energy sensor 120 on the optical port 625 . Alternatively a laptop, palmtop, or cell phone may be used to establish a communication link 630 to the RF device or energy sensor 120 . Alternatively the communication link may be hard wired or using a limited range RF communication. The handheld device 635 may be able to record the identification tag represented by the barcode 615 from the energy sensor 120 . Alternatively the handheld device 635 may be able to read the Radio frequency identification (RFID). Alternatively the handheld device 635 may read the bar code 615 c on the energy sensor 120 to record the identification tag. The operator of the handheld device 635 may be able to enter any location or setting notes into the handheld device 635 . This information may be added using the area 620 c or the keyboard 650 . This information can either be immediately sent over the RF mesh network to the energy management station 100 or recorded in the handheld device 635 and synchronized to the energy management station 100 at a later time. Alternatively the handheld device 635 may comprise at least a part of the energy management station 100 . The handheld device 635 may contain an RF device and be operable to communicate directly on the RF mesh network. Alternatively, the handheld device 635 can connect to the RF mesh network via the IRDA communication link 630 made to the RF device. The handheld device 635 may be able to integrate itself into the mesh network and report s the identifications of the units around it. The handheld device 635 may be able to display routing information from the energy sensor 120 to the energy management station 100 in addition to the RF strength and RF robustness of the network between the RF device or energy sensor 120 and the energy management station 100 .
The installer or commissioner of the RF device can make use of a GPS (Global Positioning System) to determine the location of the metering point. This information may then be recorded on the break-off tag 605 , peel-off tag 610 , or handheld computing device 635 . Alternatively, the location information may be recorded by the installer manually and entered into the energy management station 100 . A preferred embodiment may include the GPS system 630 coupled with the handheld device 635 with the physical location being automatically recorded in the handheld device 635 . Alternatively another positioning system may be used as the GPS system 630 may not function correctly at some install sites.
The energy management station 100 may be operable to estimate the physical location of the RF device using triangulation. This is done by using the RF mesh network and existing knowledge of the location of at least one other RF device. The location detection is completed using RF devices at known locations, speed of RF transmission, as well as the strength of RF transmission from an RF device at a known location to the RF device.
A camera may be used to further indicate the RF device position and install location. A digital camera can be coupled with the handheld device 635 . This image may be communicated via a communication link to the energy management station 100 .
As depicted in FIG. 6 , a microphone 640 is included in the RF device or energy sensor 120 . This microphone may contain an actuation button and can be used by the installer of the RF device to record a brief message. This message can be used to determine the location of a energy sensor 120 or RF device and the recommended settings for the RF device. The energy sensor 120 may use the RF mesh network to transmit the message to the energy management station 100 for retrieval by an operator at the energy management station 100 . Voice communications may be transmitted in between two RF devices or an RF device and the energy management station 100 . Alternatively, the energy management station 100 or the RF device may use voice recognition to determine the location from the installers message.
Referring to FIG. 7 , a block diagram of the internal components that may be used in an energy sensor 120 is depicted. The energy sensor 120 and other RF devices such as the RF repeater converter 110 , RF repeater 115 , RF display device 140 , and RF strength sensor may be derived from a limited combination of the internal components of a full featured energy sensor 120 described below.
The energy sensor 120 may contain five sections, a power section 800 , a measurement section 826 , a communication section 858 , control section 883 and a processor section 890 . Each of these sections is discussed in more detail below. The energy sensor 120 may be completely implemented within an ASIC chip or alternatively any combination of the blocks described to make up the energy sensor 120 may be implemented within an ASIC chip.
The power section 800 may comprise of a power coupling device 805 , a power rectifying circuit 810 , energy storage device 815 , and a power control unit 820 . The power-coupling device 805 is used to couple with the alternate power source. This may be but is not limited to a thermal electric generator, solar panel, electrical power, battery, vibration generator, or alternate energy converter used to harness one of the other alternate power supplies as described above in the power supply section in this document. The power rectifying circuit 810 is used to convert an alternating or fluctuating power source to a more stable DC power source. It may use the energy storage device 815 to store excess energy that in turn is able to supply power when the alternate power source is unable to supply required power for the device. The energy storage device 815 is typically a super capacitor or rechargeable battery. The power control unit 820 is controlled by the microprocessor 825 . The microprocessor 825 may be able to monitor the energy available via the power rectifying circuit 810 and determine how much power each component in the energy sensor 120 is to receive via the power control unit 820 . Alternatively, the power control unit 820 may contain a microprocessor and be operable to control at least part of the power distribution within the energy sensor 120 .
The measurement section 826 may comprise a measurement-coupling device 830 , an analog to digital converter 835 , a microphone 840 , a camera 845 , a digital input 850 , and a keypad 865 . The measurement-coupling device 830 may be used by the sensor 120 to make an analog measurement of an energy parameter. The A/D 835 converts this energy parameter from an analog signal to a digital signal. The microphone 840 is used to convert a sound recording to an analog signal. The A/D 835 may convert this to a digital signal. The microprocessor 825 may be able to store the sound recording in memory 855 and may be able to transmit the information recorded to the energy management station 100 or another RF device. Similarly, the camera 845 may be used to record an image or stream of images that may be stored in the memory 855 and may be transmitted to the energy management station 100 or another device. The digital input 850 couples with the microprocessor 825 and may be used to monitor the status of a switch, a breaker, or to monitor pulses from another metering device such as a flow meter, gas meter or electrical meter. The keypad 865 can be used to switch displays or make a change in the setup of the RF device.
The communication section 858 may comprise a display 860 , communication port 870 , RF transceiver 875 and RF antenna 880 . The microprocessor may use the display 860 to provide information to the user such as measurement parameters, setup information, and measurements. The communication port 870 may contain more than one communication channel. The communication port 870 may be used to drive the IRDA port and in addition another communication port 870 may directly coupled to an Ethernet, modem, power line carrier, or serial port. The RF transceiver 875 may be used by the microprocessor 825 to transmit and receive communication packets wirelessly on the RF mesh network. Alternatively, the RF transceiver 875 may be separated from the sensor 120 and may couple with the microprocessor 825 through the communication port 870 .
The control section 883 may comprise an analog output 884 and a digital output 885 . The analog output 884 may be used to transmit the measurement information via an analog signal to another device or be used to perform a control function such as but not limited to controlling a thermostat. The digital output 885 can be used to transmit the measurement information in the form of pulses or to perform a control action such as but not limited to tripping a breaker, resetting a breaker, turning on an alarm, etc.
The processing section 890 comprises a microprocessor 825 and a memory 855 . Some of the tasks the microprocessor 825 is used for include storing and reading data within the memory 855 , coordinating the power distribution in the sensor 120 via the power control unit 820 , creating and reading communication packets, encoding and decoding the communication packets for the wireless network, and reading measurement via the A/D 835 .
The memory 855 may be used to store any communication packets created by the microprocessor 825 or received from another RF device 200 within the memory 855 . The communication packet would be held in the memory 855 until such time they are transmitted on the mesh network or an acknowledgement is received that the packet has been received by another RF device 200 or by the energy management station 100 . These stored packets may consist of packets generated within the microprocessor 825 or communication packets received from another RF device being held for retransmission on the mesh network. If a transmission was received acknowledging that a received packet was either retransmitted using another RF device or acknowledgement from the target device was received, the stored communication packet may no longer be held for transmission. There may be a direct link between a component in the communication section 858 and the memory 855 to better facilitate this transfer of communication packets for storage. Alternately, the communication section 858 may make use of a separate memory area for storage.
This storage of communication packets may occur if the power control unit 820 logic shuts down any outgoing RF transmissions due to the power requirement to make such a transmission and where the communication packets created by the microprocessor 825 or received over the mesh network are stored until sufficient power is available to make the RF transmission. Any communication packet 1000 received over the mesh network or data created by the microprocessor 825 may be stored directly in the memory or processed by the microprocessor so that only relevant, important or high priority data is stored within the memory 855 or that the data or communication packet is compressed before storage.
At least some data within the communication packet 1000 that is received or created by the RF device 200 may be stored within a memory in the RF device 200 . This data may be stored until the space allocated within the memory 855 to store such data nears capacity, the data is deemed irrelevant, or a communication is received by the RF device 200 that the data was received by the target RF device 200 or the energy management station 100 . The energy management station 100 or target RF device 200 may send out a periodic communication packet 1000 that indicates a least one specific communication packet 1000 was received. If this communication packet 1000 is received by a RF device 200 holding a at least a piece of the communication packet 1000 referenced, the RF device 200 may delete or mark the for deletion any data stored for the referenced communication packet. Intermediate RF devices 200 may send a similar communication packet 1000 to the mesh network indicating the data it has received and is holding until acknowledgement is received that the original communication packet 1000 reached its destination. A RF device receiving this communication from an intermediate RF device 200 that is closer to the target RF device 200 or energy management station 100 may similarly delete or mark for deletion any data it is storing from the reference communication packet 1000 . Alternately any RF device 200 that receives a packet acknowledging receipt of a communication packet 1000 may log the fact that the data is being held at another RF device 200 but not immediately delete or mark for deletion the referenced communication packet 1000 .
The data integrity function in the RF devices 200 may delete or mark for deletion data in a non chronological manner. For instance, if a specific RF device 200 holds data for every fifteen minutes for the last day and has been unable to transmit this data to the energy management station 100 or another RF device 200 to be stored and the memory allocated to store the fifteen minute interval data is reaching capacity, rather than deleting the oldest data in the memory, the data integrity function may remove intermediate data such as every other fifteen minute data so that while data is being lost by the system there remains a distribution of data over the whole range. Eventually, the memory may only contain data with a half an hour interval or hour interval. The data integrity function may alter the remaining records such that data is not completely lost. For example, if average energy usage over a set interval was to be deleted, the data integrity function may merge the data with the next record in the memory log. Alternately, if the maximum demand over an interval was to be deleted, the data integrity function may modify the next chronological record to store the maximum of its recording and the recording to be deleted. Alternately, instead of the complete log entry for a specific timestamp being removed, the data integrity function may only remove specific data such as the lowest energy demand reading from the memory logs.
Alternately, the data integrity function may limit or reduce the number of bits of memory used to store numeric values and thus effectively reduce the number of significant figures within a numeric record. For example, rather than using 8 significant figures to store an accumulated energy reading, the data integrity function may dynamically reduce the number of significant figures in a data log storing only 7 significant figures and thus freeing up a few bits of memory space for each record stored. The number of significant figures or number of data bits used to store a value may be recorded by the RF device 200 and the energy management station 100 to indicate a confidence value to the stored reading in the database 103 .
The microprocessor 825 may be operable to perform energy calculations at a metering point and store the energy values in the memory 855 . In addition, it may be able to control the power distribution within the energy sensor 120 through the power control unit 820 . In addition the microprocessor is able to encode and decode the communication packets sent over the RF transceiver 875 .
Referring to FIG. 8 , the measurement-coupling device 830 doubles as a power-coupling device 805 . For example, the energy sensor 120 may incorporate a non-intrusive CT and be used to monitor electrical current in a non-intrusive manner such as the electrical energy sensor 500 shown in FIG. 6 . The current induced in the measurement-coupling device 830 (non-intrusive CT) may be switched to the power rectifying circuit 810 or the analog to digital converter by a switch 895 . Typically, when a measurement is being taken, the output of the measurement-coupling device 830 is switched by the microprocessor 825 to the analog to digital converter 835 to reduce the CT burden of the energy sensor 120 , during this time, the energy sensor 120 is powered from the energy storage device 815 otherwise the current is switched to the power rectifying circuit 810 . The energy sensor 120 is able to measure the current flowing through the conductor 900 that passes through the center of the sensor 120 . As shown in FIG. 6 , the current carrying wire may be held in place by the tabs 905 effectively holding the sensor to the current carrying wire. The electrical energy sensor 500 embodiment of energy sensor 120 may contain two main separable pieces, 925 and 930 . The section 925 may contain all the electronics as well as a large section of the non-intrusive CT; however, it is possible for both sections to contain the electronics. The remaining section 930 can be removed so that the electrical energy sensor 500 can be placed around the current carrying wire at which time the section 930 is connected to the section 925 which in combination comprises a CT core around the current carrying wire 900 .
The indication of the actual voltage may be supplied over a RF link or by an operator. The operator may use a standard voltage meter to measure the voltage and input the measured value into the electrical energy sensor 500 , a handheld unit 635 or energy management station 100 . Alternatively, there may be voltage leads or voltage terminals on the energy sensor 500 that allows direct measurement of voltage. This may allow the computation of additional power parameters in the electrical energy sensor 500 such as kW, kVAR, kVA, etc.
The electrical energy sensor 500 may be able to use a specified voltage and power factor to calculate energy and power information from the current readings of the electrical energy sensor 500 . An electrician may specify the voltage and power factor. Alternatively the power factor may be able to be determined using a voltage phase detection with a capacitive voltage detector as described above. Alternatively, voltage may be provided to the electrical energy sensor 500 from another IED device that may be monitoring voltage at another location where the voltage in the wire can be derived. This may be calculated by using a known voltage on another bus and the PT ratio or electronic equipment used to couple the two electrical busses together. Alternatively, the calculations for power factor, voltage, energy, and power may be done in the other RF devices such as the RF display device 140 . Alternatively the handheld device 635 or the energy management station 100 may be used.
The energy sensor 120 may be able to monitor any meter, such as a water, air, gas, electric or steam meter, via the digital input or an analog sensor used as the measurement coupling device 830 and wirelessly transmit the data to another RF device or the energy management station 100 .
The energy management station 100 may be software residing on a computer, handheld device 635 , or firmware residing on an intelligent electronic device (IED) such as IED 135 . The energy management station 100 is coupled with a repeater converter 110 a that allows it to communicate over the network and receive data from the energy sensors 120 within the wireless mesh network. Alternatively, the energy management station 100 is able to communicate directly on the RF mesh network. The energy management station 100 is operable to receive power up and power down messages from the RF devices and alert the system operator.
The energy management station 100 may automatically detect new RF devices added to the mesh network or added within the communication range of the energy management station such as through a serial connection, existing modem connection, wireless transceiver, Ethernet connection, or a combination of these communication mechanisms or other communication mechanisms. The energy management station 100 may automatically configure communication with the RF device and may immediately start to record configuration, identification, and measurement data from the RF device or energy sensor 120 into the database 103 . If the configuration data is changed in the future, the option may be made available to make the change retroactive within the database. This allows the correction of any setup error or delay in the entry of the configuration settings.
The data that is collected at the energy management station 100 in the database 103 may be used for energy cost analysis. The RF devices may reduce the cost of ownership of each metering point and therefore may allow many additional metering points monitoring energy further down the energy distribution system closer to the individual loads. This allows a large amount of data to be known throughout the complete energy distribution system. The energy management station 100 may be able convert this data to energy distribution system knowledge and may present it in such a way as to make the economic consequence of various energy consuming loads, energy storage, and energy generation clear to the system operator. This allows the system operator to make informed decisions concerning the use of energy dollars within a facility.
It may be possible to have additional energy management stations 100 within an energy distribution monitoring system. A preferred embodiment utilizing more than one energy management station comprises stations that may coordinate communication activities with one of them taking on the role of a master station and the others as client stations. An alternative embodiment of using more than one energy management station 100 comprises at least one of the additional energy management stations 100 acting independently of the rest, logging, displaying, analyzing, and alarming on the data independently.
The energy management station 100 may be able to send a known or specified voltage and power factor to an energy sensor 120 . This may allow the energy sensor 120 to calculate energy and power information from the current sensed in a current carrying wire. Alternatively the additional calculations to determine the power and energy parameters may be done at the energy management station 100 either as the real time values arrive or at a later time based on the data collected from the energy sensor 120 . The voltage may be a specified by the system operator or alternatively the energy management station 100 may be able to estimate the voltage based on the voltage read through another energy sensor 120 or IED 135 that it is able to communicate to. In addition, the energy management station 100 may be able to analyze the supplied energy distribution system and calculate the voltage passed through various transformers, breakers, or switches to determine what the voltage may be at the energy sensor 120 . For example, if the voltage can be measured at a 480V bus the energy management system may be able to recognize a transformer on the one line energy distribution network diagram and determine what the voltage might be at the load side of the bus where the energy sensor 120 is installed. These calculations may include transformer and line loss calculations. Similarly it may be able to estimate power factor using this method as well as knowledge of the load and the electrical components between the power factor that is being measured and the load.
The voltage, phase, and current readings may be used to calculate other energy and power parameters such as kW, kVAR, and kVA. The voltage and phase may be specified by a system operator, measured from another energy sensor or voltage meter, or be calculated based on various specified and measured values throughout the energy distribution system as discussed above. The energy management station 100 may be operable to store the measured, specified, and calculated parameters within the database 103 . Alternatively the RF devices may be able to store these parameters within an internal database. These parameters may include a measured current, specified power factor, specified voltage, calculated kW, calculated kVAR, and calculated kVA. Alternatively the voltage phase may be detected using the capacitive voltage detection discussed above. The voltage phase may be used to calculate the power factor. In addition, the capacitive voltage detection may be able to determine a change in the line voltage from the specified voltage. If available, the measured voltage and calculated power factor may be stored in the database and may be at least partially used in the energy and power calculations. Other information may be stored in the database 103 such as specified error tolerances for specified values and calculated error tolerances for calculated and measured values. In addition, timestamp information, physical device location, device identification, other energy parameters, energy events, etc may be stored within the database 103 .
The energy management station 100 may be able to access the RF signal strength within each wireless connection on the mesh network and estimate the coverage of the mesh network. It may be able to display this information on a geographical map showing the estimated and measured coverage of the RF mesh network. The RF signal strength, error rate, signal to noise ratio and utilization of each wireless connection may also be represented on the diagram. Alternatively this information may be displayed on an energy distribution diagram. In addition, the energy management station 100 may be able to analyze the mesh network and based on signal strength and error rate, and may be able to suggest where an RF repeater 115 may be located to increase the coverage and robustness of the network.
The energy management station 100 may be able to perform an upgrade on an RF device over a wireless link. Preferably this wireless link is an RF mesh network and at least one routing path may exist between the RF device and the energy management station 100 . Alternatively, a portion of the communication path may be an alternate communication medium such as an Ethernet connection. In addition, if more than one routing path exists to the RF device, it may be possible for a faster communication rate and thereby a faster firmware upgrade to the device. The RF devices may be able to signal to the energy management station 100 if they have sufficient backup power for a firmware upgrade in the event that an external power supply fails.
The microprocessor in the energy sensor 120 , RF devices, and the energy management station 100 may assemble the RF communication data packets 1000 . In addition the microprocessor 825 in the energy sensor 120 may be able to calculate energy parameters as well as construct, encode and decode RF communication data packets 1000 . This RF communication data packet 1000 may be optimized for efficient, high speed, low collision communications. In addition, the communication data packet 1000 may be highly flexible in that it may contain only a few energy parameters to a large amount of energy parameters and from only a few pieces of routing information to a large amount of routing information. As shown in FIG. 5 , some of the information that may be contained within the RF wireless payload includes a packet start marker 1005 or preamble, sensor ID 1010 , EEM data 1015 , routing information 1020 , signal strength 1022 , battery life 1025 , time of data collected 1030 , time sync information, physical location 1035 , energy distribution metering location, volts 1040 , power factor 1045 , current 1050 , I2R 1052 , V2h 1053 , watts 1055 , VAR 1060 , VA 1065 , public security key 1070 error codes 1073 and a packet end marker 1075 .
The error codes 1073 may comprise of a cyclic redundancy error checking or preferably contain forward error correction. The forward error correction may be used by the receiving RF device or energy management station 100 to correct information in the data packet that may have been corrupted during transport. Using forward error correction may increase the wireless mesh network range, decrease the required RF antenna, decrease the transmit power required at each RF device and assist in any corruption of the data packet occurring during transport such as transport over long distances or outside of a partial RF shield. The RF devices may be able to intelligently assemble the information in each packet so not to include redundant or unnecessary information within the RF payload. A RF device or energy management station 100 may assemble a communication data packet 1000 to be used as a time sync another RF device or energy management station 100 . An RF device or energy management station 100 receiving or processing the communication packet 1000 containing the time sync, may be able to adjust it's time to correspond to the time sync sent in the communication packet. The time syncing process may account for any packet decoding delays and speed of communications. The communication packet 1000 may be digitally signed and may use a private key and public key signing system. Alternatively the communication packet 1000 may be digitally encrypted and may use a private key and public key exchange between two or more RF devices including the energy management station 100 .
Referring now to FIG. 2 , an example of a communication diagram is show that depicts radio frequency (“RF”) devices communicating on a wireless mesh network. The wireless mesh network composed of radio frequency (“RF”) devices 200 used to transmit communication data packets between the energy management station 100 and the RF devices 200 . An RF device 200 includes at least one of RF repeater converter 110 , RF repeater 115 , energy sensors 120 , RF signal strength sensors or RF display devices 140 . This figure shows RF device 200 a linked to RF device 200 b over wireless communication link 150 a , and RF device 200 b linked to RF device 200 d over communication link 150 b . RF device 200 d is linked to RF device 200 c over communication link 150 e and to the repeater converter 110 . RF device 200 c is linked to repeater converter 110 over communication link 150 c . The repeater converter 110 is linked to the energy management station 100 over a direct link 205 . The energy management station 100 is connected to a database 103 .
With any communication network tying together energy sensors, it is important to ensure the robustness of the network. Typically this is sometimes taken for granted with a wired communication system; however, even in a wired case problems may appear and data can be lost. With a wireless network, especially a low powered, adhoc network such as mesh wireless communication system, critical paths may be disabled and communication between energy sensors and energy management station or data storage location may be delayed. In a wireless communication network, especially an ad-hoc mesh network, there may be additional reasons to employ a communication validation function. A communication validation function may provide a measure of robustness or redundancy between communication paths. This may be during the commissioning of a system to ensure better operation after the commissioning process.
The present embodiments' energy management station 100 , RF display device 140 , and RF signal strength sensor may have a user display that can show the RF routing paths available between various RF devices. This information can be coupled with the physical location of the device if it is known and the present embodiments are capable of showing the possible routing paths as well as indicating the strength of each RF link. The RF display device 140 , RF signal strength sensor and energy management station 100 may be able to analyze this data and indicate the best locations to add repeaters or sensors. Alternatively the installer or commissioner may be able to quickly pick out the best locations for an RF repeater 115 based on the presentation of the routing paths and signal strengths. For example, FIG. 2 is a representation that may be displayed to the installer. Each RF link 150 shown may include an indication of signal strength such as a number, symbol, bar indicators or colors that indicate the signal strength over the communication link 150 . In addition, a distance, signal to noise ratio, and error rate of the communication path may be calculated, stored in a database 103 , and shown on the diagram. The distance for a communication path may be determined by sending a small communication “distance ping” between two RF devices and determining the distance based on the time the distance ping was sent and received at a RF device, hardware delay, and speed of communication medium.
There is a need to represent link quality between nodes using a simple measure. While the link quality can be disclosed using signal to noise ratio or bit error rate, the meaning of these terms are not always well understood by operators. A way to compile this data or engineering measures to a common link quality indicator is important. One method of representing the link quality between nodes can be through a number of nines indicator. For example, 2 number of nines may indicate that 99% or 99 out of 100 communication packets are successfully transmitted over the link. This could be referred to as probability of success. The communication validation function may be able to indicate the number of nines between two individual nodes directly or between two individual nodes using a network of intermediate nodes.
This representation of link quality may be able to indicate were wireless mesh repeaters need to be moved or added to increase the robustness of the mesh network while keeping the costs of adding additional repeater low. The communication validation function may be able to include redundant intermediate paths using various intermediate nodes between two communicating mesh nodes or a mesh node and the energy management system within the calculation of link quality indication.
The communication validation function may alarm when one or more communication links throughout the energy management system fall below a certain link quality. The alarm may be triggered by a percentage drop in the link quality from a normal or average link quality for a specific communication link or when the link quality passes a preset threshold. This link quality may be a representation such as the number of nines discussed above or signal to noise ratio measured between two RF devices. The communication validation function may alarm when communication to a node or through a communication path is no longer viable.
One way the communication validation function may ensure a good wireless communication network is to track the path taken by at least some of the packets.
Each RF device 200 may add a marker to packets it passes. The marker may be a few bits of information incorporated within or added on to either end of the communication packet 1000 . The route information 1020 within the communication packet 1000 may be used to contain this “route taken” information.
Alternatively, each RF device 200 may simply store an identification information from the communication packet to indicate that it received the packet. This identification information may be stored in the RF device 200 along with course of action information. For example, each RF device 200 may contain a log containing identification of each packet it received or created, where the packet was received from, time the packet was received, and what action was taken such as retransmitting the packet to the mesh network. This communication log may be transmitted to the energy management station 100 at a preset interval or upon request from the energy management station 100 . Alternatively, the communication log may be transmitted due to an failure within the mesh network or RF device 200 . The communication log may either be pushed from the RF device 200 to the energy management station 100 or be requested by the energy management station 100 . The communication log may be used by the communication validation function to track the use of the mesh network.
The communication verification function may be able to indicate the existence, usage and reliability of wireless links formed within the mesh network. For example, in FIG. 2 , through analyzing the path at least some of the communication packets 1000 took, the communication verification function may be able to indicate that communications paths 150 a - 150 e as shown connect RF devices 200 a , 200 b , 200 c , 200 d and the repeater converter 110 . In addition, the communication verification function may be able to determine the number of proven paths a specific RF device 200 may be able to use to communication to the energy management station. For example, RF device 200 d may use mesh link 150 d to communication directly to the repeater converter 110 or may use wireless link 150 e , RF device 200 c , and wireless link 150 c to communicate to the repeater converter 110 . The communication verification function may be able to determine critical paths such as indicated by RF device 200 b with only one wireless link 150 b to get information to RF device 200 d and the rest of the network. Conceivably, if either wireless path 150 b or RF device 200 d were not functioning properly or unavailable, the data in RF device 200 a and RF device 200 b would be unable to reach the energy management station 100 . The communication verification function may be able to detect this possibility of only one critical path and take action such as create an alarm or indication to the user. The number of redundant paths required may be set by the user or commissioner of the system. For instance, the system may be set to ensure that there are at least 3 independent paths.
The communication verification function may temporarily disable certain wireless paths to check if the mesh network is able to generate a backup or redundant path. The command may indicate to only stop for a set amount of time or to stop until another command is received to resume. Before temporarily disabling the communication link 150 , the communication verification function may send a command to a device to transmit a message at a regular interval. By temporarily disabling a certain wireless path or a RF device 200 from repeating any mesh signals, the communication verification function may be able to find out if an alternate path exists. For example in FIG. 2 , the communication verification function may send a message to RF device 200 a or RF device 200 b to transmit a packet to the energy management station 100 at a regular interval 1 minute interval. The internal may be set to any length. Then the communication verification function may send a signal or communication packet to RF device 200 d to stop retransmitting packets on the mesh network or the instruction may be more specific to stop transmitting packets sent from RF device 200 b to the mesh network for 5 minutes. By effectively disabling the communication path 150 b , the communication verification function is able to verify if the mesh network is able to adopt and determine if there is an alternate path. For instance, in the example above, the mesh network may find an alternate wireless path between RF device 200 a and RF device 200 d in which the wireless path 150 b is not critical to operation but perhaps RF device 200 d is critical. Further the communication verification function may send a command to RF device 200 d to temporarily stop repeating any mesh communication from either RF device 200 a or RF device 200 b . In this case, the communication verification function may be able to determine if there is a link between RF device 200 a or RF device 200 b to any other the other RF devices 200 besides RF device 200 d . The communication verification function may alarm or set off an alarm within the energy management system 100 . The alarm may be transmitted over the wireless mesh network to a handheld device or mobile indicator 140 .
If the communication verification device is unable to determine enough alternate paths exists for the mesh network reliability, it may indicate that an additional repeater 115 or RF device 200 should be installed. The communication verification function may be able to indicate the general or specific area that this repeater 115 should be installed. Alternately, the communication verification function may indicate which RF nodes need an alternate communication path. For instance, as shown in FIG. 3 , a RF repeater 115 was added that created direct links to RF device 200 a , RF device 200 b and RF device 200 c over wireless communication links 150 g , 150 h and 150 i.
Referring to FIG. 4 , an embodiment of mesh network is shown with multiple repeater converters 110 to used to convert the mesh wireless signals to a media and protocol that is able to interface with the energy management station. The communication path 205 between the repeater converters 110 a and 110 b may be two independent communication connection from each repeater converters 110 a and 110 b to independent communication ports on the energy management station 100 such as but not limited to an RS 232 or USB connection. Alternately, these may share a signal communication interface such as but not limited to a wired or wireless Ethernet connection or RS-485 link. The repeater converter 110 a may be sufficient to send and receive communication to the whole of the mesh network; however, repeater converter 110 b may be added to increase reliability of the mesh network. This repeater converter 110 b may function as a mesh repeater to hop signals from RF device 200 a to RF device 200 c and may function as an additional path for the RF mesh devices 200 to send and receive communication packets 1000 to the energy management station 100 . This may reduce possibility of a network outage if repeater converter 110 a is temporarily unavailable.
The repeater converters 110 a and 110 b in FIG. 4 may communicate to each other which RF devices 200 each are primarily responsible for communication. For instance, repeater converter 110 b may primarily repeat communication packets 1000 between the energy management station 100 and RF devices 200 a and 200 b while repeater converter 110 a may be the preferred mesh path for communication packets 1000 between the energy management station 100 and RF devices 200 c and 200 d . This organization between the repeater converters 110 b may be a function of better quality data links to destination RF devices 200 , lower number of hops to destination RF devices and load balancing of communication packets 1000 between the RF devices 200 . In addition, the RF devices 200 and the repeater converters 110 a and 110 b may alter their RF transmission power such that messages are only received by RF devices 200 within a limited RF range. This may allow for more than one message to be simultaneously carried by the mesh network. For example, this may allow repeater converter 110 a to communicate to RF device 200 d at the same time repeater converter 110 b is communication with RF device 200 a.
The RF devices 200 may determine the next RF device 200 that is typically the successful wireless path of communication packets 1000 sent to a specific destination. The RF device 200 may send the next communication packet it receives that has the same specific destination to the specific RF device 200 on the first retransmission attempt such to reduce the number of RF collisions by other RF devices 200 receiving and retransmitting the communication packet. For example, in FIG. 3 , a wireless communication packet 1000 sent from RF devices 200 a with a target destination of the energy management station 110 may be able to be reached by both the RF device 200 b and RF repeater 115 and potentially retransmitted from both. However, typically the quickest or most successful path for mesh communication from this RF device 200 a includes the RF repeater 115 and not the RF device 200 b . This may be determined by RF device 200 a from a communication packet 1000 from the energy management station 100 , RF device 200 b or RF repeater 115 acknowledging the receipt of the information and the most successful wireless path used to deliver the communication packet 1000 . Alternately the data integrity function in the energy management station 100 may determine the best wireless paths of the communication packet 1000 it received and if the that path was specified by the originating RF device 200 a and any intermediate RF devices 200 . If the path was not specified or incorrectly specified, the data integrity function may and for at least one specific destination and send out communication packets 1000 with instruction to specific RF devices 200 on the preferred path to use to retransmit data to that one specific destination to the RF devices 200 . With this information, the next communication packet 1000 sent by RF device 200 a may be specifically addressed to only be repeated by repeater 115 to the energy management station 100 . Repeater 115 may interpret the communication packet 1000 is to be sent to the energy management station 100 and then using it's own determined best path to the energy management station 100 , repeat the transmission and specifically address RF device 200 c which would then repeat it specifically to repeater converter 110 which would convert the communication packet 1000 to interface to the communication link 205 and send the communication packet to the energy management station 100 . The data integrity function within energy management station 100 may analyze the communication path taken by the packet, log the communication path taken, or instruct RF devices 200 within the mesh network of an alternate communication path this use with the next communication packet 1000 targeted to the same nodes.
The RF devices 200 and IED 135 may contain the data integrity function where the data integrity function includes routines to clean or self healing of the data. This may be referred to as a data validation engine (“DVE”) and at least a portion may be contained with the energy management station 100 . This data integrity function may include a self healing function where missing data is filled in or rebuilt from logged data within the original device or from other sensors. An example of this where energy data may be monitored at an incoming point at a certain energy junction as well as the outgoing points where one of the monitoring points data logs are missing data. The self healing function may recognize that energy metering flow into and out of this junction point nets zero meaning all energy supplied to this junction is accounting for by the outgoing energy meters. For example, in FIG. 1 , the energy measured by IED 135 is distributed by the two feeders measured by energy sensors 120 b and 120 c . If data is missing from energy sensor 120 b , the self healing function may be able to calculate the missing data from subtracting any data measured in energy sensor 120 b from IED 135 . Alternately, if the data is missing from both energy sensor 120 b and 120 c , the self healing function may be able to determine the average percentage of energy delivered via both feeders and divide the energy measured by IED 135 . Alternatively, if the data is missing from IED 135 and the energy sensor 120 c , the self healing function may be able to closely estimate the IED 135 from the measured data in energy sensor 120 b and the percentage energy that energy sensor 120 b typically monitors of the whole energy delivered by IED 135 . This type of data healing may occur from any of the energy sensors 120 or IED 135 within the system with some logged or preset data of the relationships between the energy sensors 120 or the IED 135 .
Referring now to FIG. 9 , an exemplary flowchart is used to illustrate one embodiment for monitoring data quality within a RF device 200 or IED 135 used within an energy management system. This example depicts a data quality system that includes at least one of two methods of verifying the quality of the energy data measured by a sensor or receive over communication packet from another sensor. These two methods are a validation and estimation of the energy data and a communication acknowledgment system. The blocks or sections within the data quality system 960 may span over multiple devices. Alternately, some of the validation, estimation and editing (“VEE”) functions or additional VEE functions may be performed in the energy management station 100 . The data quality system 960 is processed on at least one of measured energy data (block 962 ) and energy data received over communication network (block 964 ). The energy data or communication packet 1000 received may be stored in memory (block 966 ) within the device such as but not limited to memory 855 . Storing the energy data in block 966 may be optional portion of this process and in some cases the whole communication packet 1000 may alternatively be stored with a memory. Alternately the energy data may come from historical data records already stored with the memory as shown in block 961 . The data quality process 960 may include a validation and estimation functions which may included one or more of the processes indicated by blocks 968 , 970 , 972 , 974 , 976 , 978 , 980 , 982 , 984 , 986 and 987 . The validation and estimation functions are described in the description the follows. If the validation and estimation functions are not included in the data quality process 960 , the process moves from storing the energy data in block 966 to transmitting the data to the network in block 988 . The data quality system 960 may include a communication acknowledgement system shown in block 990 , 992 and 994 discuss in the description to follow. If the data integrity system does not include the communication acknowledgment system, it may be complete at block 988 .
The communication acknowledgement system may wait for an acknowledgment to be received from another RF device 200 used to further transmit the communication packet 1000 to a designated endpoint or from the endpoint itself once it has received the communication packet 1000 either directly or through other RF devices 200 . This waiting for acknowledgment is shown in block 990 . If the acknowledgment is not received within a set amount of time as shown in block 992 , the communication packet may be retransmitted to the network in block 998 . The RF device 200 may change the communication packet 1000 before retransmitting to the network to affect routing within the network. Alternatively, the RF device 200 may use another method of communication if available. An example, the alternate method of communication may be but not limited to a backup method of communication using an interface over a plain old telephone system (“POTS”) line, a paging network, cellular network, alternate radio frequency or modulation, or a satellite connection. Using this communication validation system, once an acknowledgment is received, the data that may still be stored with the memory of the RF device 200 or IED 135 is marked as received by the endpoint or a subsequent RF device 200 within a wireless communication network.
The RF devices 200 and IED 135 data integrity function may include a validation function, estimation function and editing function. Any individual function or combination of these three functions may reside within a validation, estimation, editing (“VEE”) function. This VEE function may exist in any of the energy sensors 120 , repeaters 115 , and repeater converters 110 within the mesh network. The VEE function may comprise of one or more VEE rules. These VEE rules may comprise any number of validation rules, estimation rules and editing rules. Placing VEE functions and VEE rules into the IED 135 or RF devices 200 directly may reduce the processing burden on the energy management station 100 . In addition, any users that use an energy management station 100 that does not include a VEE module may still benefit when the actual measurement devices, such as the EED 135 or RF device 200 , or communication devices, such as the RF repeater 115 , RF repeater converter 110 , or any hardware used to receive and transmit communication packets, contain VEE functionality at the device level. The VEE function may be able to process a measurement or logged measurement made by an energy sensor 120 or EED 135 to ensure that reading complies with any preset VEE rules.
FIG. 9 indicates one embodiment of this validation and estimation process within blocks 968 , 970 , 972 , 974 , 976 , 978 , 980 , 982 , 984 , 986 and 987 . As energy data enter this process at block 968 from either blocks 961 , 962 or 964 (may pass through block 966 ) a validation process is run against the data using one or more validation rules. If the data passes the validation process at block 970 , the data is marked as validated meaning it has passed validation at block 972 and is transmitted to the network at block 988 . If the data did not pass the validation process at block 970 , it may be marked as failing validation at block 974 and may have estimation process and rules run on the energy data at 976 . This estimation process may use data from other RF devices 200 , IED 135 , or historical energy data intervals. At block 978 , if unable to calculate an estimation value using available estimation rules, the data is marked with an estimation failed indication (block 986 ) as may stored within the memory (block 987 ) for further editing or to run through this estimation process once new data is received or measured. If at block 978 , the estimation process is successful, the data may be marked as estimated (block 980 ) and may have a validation process (block 986 ) run against the newly estimated value. This validation process (block 986 ) may use different validation rules from the validation process at block 968 . If the validation process is successful (block 984 ), the data may be marked as passing validation; however, the data may retain the estimation indication from block 980 . The data or data record may then be stored or updated in the memory of the device at block 987 . If the second validation process was unsuccessful (block 984 ), the data may be marked as estimation failed and may be stored within the memory (block 987 ) for further editing or to run through the estimation process once new data is received or measured. The data may be transmitted on to the network at block 988 and carry through the process as already described.
For example, a validation rules may include but are not limited to the following examples. For example, a validation rule may check that the measured energy used over an specific interval does not exceed a maximum, check to ensure the energy readings did not increase by more than a set amount, and check another energy meters readings to verify both energy meters are within a preset percentage of each other. Another example of a validation rule may comprise of summing up all interval data during a billing period and comparing this summation to the difference between the cumulative energy reading at the end of the billing period and the one at the start of this billing period. These two numbers should be nearly equal or within a preset percentage. A typical VEE rule may compare those two numbers and accept them if they are within x % of each other.
Another validation rule example may compare any given interval data reading to the one before, and reject it if there is more than x % difference between them. Alternatively, the validation rule may compare each interval data reading to the same interval timeframe for the previous business day, month, year etc. For example, the kWh reading on Thursday from 10:15 to 10:30 should be within y % of the kWh reading on Wednesday from 10:15 to 10:30.
Another validation rule example may compare each interval data between a main meter and a backup or secondary meter. Typically all revenue metering points are nearby such that a wired or wireless communication would be possible. Again, these reading may be validated if they are within x % of each other. Typically x % may be a function of the meter's accuracy such that, for example, if both meters are class 0.2 meters, the difference between their readings should be less than 0.4%. Of course, it may be set to any value.
Another validation rule may be where the meter, RF device 200 or IED 135 may proactively recognize when specific events happen (error codes, power cycles . . . ) and flag the relevant intervals as requiring an estimation rule or editing rule. Alternatively, in the case that a measurement does not pass with a specific validation rule, the VEE function may flag the relevant interval to require an estimation rule or editing rule. This flag indication may be stored along side the measurement value or within the same set of data within the log memory 855 . This indication flag may be resilient or be made to be resilient so that the flag may remain with this set of data for the life of the data.
The estimation function may estimate the value based on previously logged measurement data, data from other sensors or alternatively mark the data unclean and wait for additional measurements. The VEE function may then use these new measurements and may use previous recorded measurements to estimate the data and replace the data. The VEE function may request data from other meters to assist the validation and estimation process. The new estimated value may have to pass the validation function before it is recorded in the memory log as valid data. An estimated value may be generated when the data being tested does not pass the validation function within the IED 135 or RF device 200 , the data is missing, the data is corrupt or otherwise unavailable.
Estimation rules that may be applied within the IED 135 or RF device 200 may include but are not limited to the following example. One example is an estimation rule that may replace bad or missing interval data with readings for the same intervals coming from the backup meter. This information may be transferred over a wired link, power line carrier, or a wireless communication link such as but not limited to IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11s optical link, or a wireless mesh network. When only one interval is missing or flagged as bad, an estimation rule may use the difference between cumulative energy reading at billing period end and cumulative energy reading at billing period start minus summation of all good interval data. For example, the billing period may begin at the start of the day and end at the completion of the day. The estimation may be calculate by the difference of the cumulative energy recorded at the beginning of the day and the cumulative energy reading at the end of the day minus the summation of all the energy demand intervals throughout the day. Another example of an estimation rule is using the average interval consumption for this site or using the same interval the day before.
The editing function may interface with a user interface, such as a display and keypad, on the IED 135 or RF device 200 and allow an operator to edit a recorded data value. The editing function may further comprise an editing rule that only allows data that was unable to pass the validation or estimation functions to be edited. Any data that has been edited may be marked with a flag to so indicate it has been edited. In addition, it may be marked by who the edit took place. The edit indication flag may be resilient or be made to be resilient such that the flag stays with the data for the life of the data. Another example of an editing rule may comprise a security process to ensure the operator attempting to change the value is authorized to edit a data value. The security process and authorization may be unique for different recorded values. For example, a recorded value such as an energy reading that may affect a bill may require different authorization than editing a voltage value. The editing process may involve the user using another device such as a handheld device 635 which comprises an user interface and is operative to communicate to the IED 135 or RF device 200 to edit a data value. Alternately, the energy management station 100 may be used to provide the user interface to allow the data value to be edited. This energy management station 100 may allow this edit process to be run locally at the energy management station 100 . Alternatively, the energy management station 100 may allow the edit to take place on the EED 135 or RF device 200 providing a user interface to the device via a communication link.
As part of the VEE function, the following interval data flags may be used. Raw data flag or no flag may indicate the data has not been through any VEE function. Any edited or estimated data may contain an edited/estimated flag. For Edited data, a trace also may be kept of the person who edited this data based on the authorization process or a user ID. Any data that has passed validation process may be marked with a validation passed flag. Any data that has failed a validation process may be marked with a validation failed flag. A verified data flag may indicate that data has failed at least one of the required validation checks but was determined to represent actual usage by either another validation flag or through an editing process. Typically a set of data may have some of its flags change as it progresses through the validation process; however, there may be 1 exception that is when the estimated or edited indication flag is set, it is resilient and remains with the specific set of data for the life of this set of data. For example, the meter accumulates a load profile for 24 hours, but the 9:00 to 9:15 interval is missing for whatever reason. The first validation attempts failed because of this missing interval, and the whole set of data is being marked as having failed validation. Then the meter estimates and creates this interval through one of the mechanisms described earlier, and flags this interval as having been estimated. Then, the whole set of data goes through validation again, and, this time, passes. At this point, the entire set of data gets marked as having passed validation, but the interval that was estimated remains marked as such forever, even though it is now part of a set of validated data.
The VEE function within the specific IED 135 , energy sensor 120 or other RF devices 200 may be able to request another measurement is taken by the original measurement device or another IED 135 or RF device 200 to assist in the validation and estimation process. Having the IED 135 or energy sensor 120 make this request rather than a VEE function on the energy management station 100 may decrease time required to take an unscheduled measurement to assist in the VEE function.
Whenever data is rebuilt from other data using the self healing function, VEE function, or other calculations, a confidence value or indicator may be generated to be stored with the data. This confidence value may indicate the level of confidence or cleanliness of the data. The confidence value may be contain a statistical probability indication of the data used within the log especially if the data was calculated using averages from the data log. In addition, the confidence value may indicate the accuracy of the sensor used to measure, calculate, or generate the energy data value. The data integrity function either within the energy management station 100 , the RF devices 200 or the IED 135 may alarm if the confidence level is outside of a preset tolerance or has significantly altered from historical levels.
It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, that are intended to define the spirit and scope of this invention.
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Systems and methods for ensuring data integrity in a mesh network. A mesh network can include multiple RF devices. Transmitting quality data in or on the mesh network is improved using communication validation functions. The communication validation functions ensure a reliable communication network, preserve data during a network outage, and validate data. The communication validation functions can measure or control data quality within a communication and analysis network. The communication validation function operates to control data quality, for example, by measuring the quality of wireless links, ensuring the presence of redundant links, testing the ability of the mesh network to establish a backup communication path, generating alarms based on communication thresholds, tracking the communication path followed by communication packets, and identifying placement locations for additional RF devices.
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BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention relates in general to drill bits and, in particular, to an improved system, method, and apparatus for a steel tooth drill bit having enhanced tooth breakage resistance.
[0003] 2. Description of the Related Art
[0004] In the prior art, steel tooth drill bits are great tools for drilling multiple formations due to the ability of their teeth to flex when encountering hard formations. However, this ability to provide flexure can cause cracking at the base of the teeth in the weld deposit and carburized area under the iron-based hardfacing deposits. Moreover, the cracks can grow during service or can aggravate pre-existing thermal cracks from the initial manufacturing process.
[0005] The manufacturing cracks can be caused by a variety of sources, but are primarily from the thermal stresses induced during the welding process while using iron-based hardfacing materials at the base of the teeth and subsequent hardening and carburization of the cone. The hardfacing can relieve the stress in the form of a crack. The cracks can propagate directly into the base steel of the teeth and/or the cone shell. The extent of the cracking is dependent upon the thermal management of the cone during the heat-up, welding, and the cooling down of the cone. Another factor affecting the extent of the cracking is how brittle the carburized case is underneath the hardfacing deposit.
[0006] During operation, the combination of the flexing of the teeth, formations drilled, operating parameters, and the corrosive environment can cause the cracks to grow while the drill bit is in service. This crack propagation can cause the teeth to eventually break off or cause the cracks to grow into the cone shell, both of which impede performance.
[0007] It is known that nickel-based hardfacing minimizes the transport of carbon into the steel substrate and generally does not produce a carburized case in the steel underneath the hardfacing deposit. In addition, the thermal stresses in nickel-based hardfacing are not as great as in iron-based hardfacing, such that nickel-based hardfacing is less likely to have thermal cracks. Nickel-based hardfacing is also very corrosion resistant compared to iron-based hardfacing.
SUMMARY OF THE INVENTION
[0008] In general, if cracks occur in nickel-based hardfacing they typically arrest in the hardfacing deposit and generally do not propagate into the steel substrate. This is primarily due to the round blunt tip crack of nickel-based materials, contrasted with the sharp tip crack in iron-based materials. However, iron-based hardfacing materials are more durable than current nickel-based hardfacing materials. The area of the teeth that receives most of the damage due to impacting is at or near the top of the teeth. Therefore, the crest and a portion of the flanks require a highly durable iron-based hardfacing. Since the bases of the teeth do not receive significant impacting those portions are very suitable for nickel-based hardfacing. By placing the nickel-based hardfacing at least at the bases of the teeth and/or the surrounding cone shell, the overall durability of the drill bit is improved.
[0009] Typically, the hardfacing is applied by an oxygen acetylene welding process, but other welding or coating processes of applying the hardfacing material may be used. Some high-content nickel alloys with hard component materials also may be used.
[0010] The bases of the teeth are provided with nickel-based hardfacing to significantly reduce any potential cracking therein and in the adjacent areas of the cone. All other portions of the teeth are hardfaced with iron-based materials such that all surfaces of the teeth are protected with one or the other type of hardfacing. In addition, manufacturers of drill bits prefer to weld with nickel-based materials due to ease of heat management in the teeth base and cone surface areas of the cutting structure.
[0011] The foregoing and other objects and advantages of the present invention will be apparent to those skilled in the art, in view of the following detailed description of the present invention, taken in conjunction with the appended claims and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] So that the manner in which the features and advantages of the present invention, which will become apparent, are attained and can be understood in more detail, more particular description of the invention briefly summarized above may be had by reference to the embodiments thereof that are illustrated in the appended drawings which form a part of this specification. It is to be noted, however, that the drawings illustrate only some embodiments of the invention and therefore are not to be considered limiting of its scope as the invention may admit to other equally effective embodiments.
[0013] FIG. 1 is an isometric view of one embodiment of a drill bit constructed in accordance with the invention;
[0014] FIG. 2 is an enlarged photographic image of one embodiment of a cutter on the drill bit of FIG. 1 and is constructed in accordance with the invention;
[0015] FIG. 3 is an enlarged photographic image of another embodiment of a cutter on the drill bit of FIG. 1 and is constructed in accordance with the invention; and
[0016] FIG. 4 is a high level flow diagram of one embodiment of a method constructed in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Referring to FIG. 1 , one embodiment of a system, method, and apparatus for an earth boring bit 11 constructed in accordance with the invention is shown. Earth boring bit 11 includes a bit body 13 having threads 15 at its upper end for connecting bit 11 into a drill string (not shown). Bit 11 is depicted with three legs, and each leg of bit 11 is provided with a lubricant compensator 17 . At least one nozzle 19 is provided in bit body 13 for spraying cooling and lubricating drilling fluid from within the drill string to the bottom of the bore hole.
[0018] At least one cutter is rotatably secured to each leg of the bit body 13 . Preferably three cutters 21 , 23 (one cutter being obscured from view in the perspective view of FIG. 1 ) are rotatably secured to the bit body 13 . A plurality of teeth 25 are arranged in generally circumferential rows on cutters 21 , 23 . Teeth 25 may be integrally formed from the material of cutters 21 , 23 , which is typically steel.
[0019] Referring now to FIGS. 2 and 3 , two embodiments of earth boring bits having cutters 21 , 23 or roller cones that employ the novel elements of the invention are shown. Although the cutters 21 , 23 and teeth 25 are shown with certain types of geometry, those skilled in the art will recognize that the invention is not limited to the illustrated embodiments.
[0020] For example, in the enlarged view of FIG. 2 , the teeth 25 on the cutter 21 of the earth boring bit are shown with two different types of hardfacing materials 31 , 33 formed thereon. The invention may be applied to only some of the teeth or all of the teeth, and on one of the cutters or all of the cutters. Furthermore, the invention also may be applied to other teeth or other portions of the drill bit other than the cutters. The first type of hardfacing 31 is formed from a nickel-based material and is located on proximal or base portions 35 of at least some of the teeth 25 . Optionally, the first hardfacing may comprise an alloy, such as a nickel alloy, or an alloy having a high nickel content with some hard component materials such as, for example, monocrystalline WC, sintered WC (crushed or spherical), cast WC (crushed or spherical), and/or with a matrix of Ni—Cr—B—Si. In the embodiment of FIG. 2 , the first hardfacing 31 also is located on surfaces of the cutter 21 adjacent the aforementioned teeth 25 , such that the first hardfacing 31 smoothly transitions from the cutter 21 to the teeth 25 .
[0021] The second type of hardfacing 33 is formed from an iron-based material and is located on distal or upper portions of the same teeth with hardfacing 31 . Thus, all surfaces of the teeth 25 and, optionally, portions or the entire surface of the cutter 21 itself is protected with hardfacing materials. The second hardfacing 33 may be located at and adjacent to the top portions of the teeth 25 , such as on the crests and portions of the flanks of the teeth. Optionally, and as shown in FIG. 3 , only the base portions of teeth 45 on cutter 40 may be provided with the first hardfacing 41 (i.e., without application of hardfacing 41 directly to the surfaces of cutter 40 ). The remaining portions of teeth 45 are protected by the second hardfacing 43 , as described herein.
[0022] Referring now to FIG. 4 , the invention also comprises a method of fabricating a cutter for an earth boring bit. The method begins as indicated at step 51 , and comprises providing a cutter with teeth extending from the cutter (step 53 ); applying a first hardfacing on portions of at least some of the teeth (step 55 ); applying a second hardfacing that differs from the first hardfacing on other portions of said at least some of the teeth (step 57 ); before ending as indicated at step 59 .
[0023] Alternatively, the method may comprise one or more of the following steps, including: applying the first hardfacing on base portions of said at least some of the teeth, and/or on surfaces of the cutters adjacent said at least some of the teeth; and/or applying the second hardfacing to crests and portions of flanks of said at least some of the teeth. In addition, one embodiment of the method may comprise sequentially applying nickel-based hardfacing (e.g., a high-content nickel alloy with hard component materials) as the second hardfacing, after applying iron-based hardfacing as the first hardfacing.
[0024] While the invention has been shown or described in only some of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes without departing from the scope of the invention.
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A drill bit having steel teeth is provided with a combination of hardfacing materials on the teeth. The bases of the teeth are hardfaced with nickel-based materials to significantly reduce any potential cracking therein. Portions of the supporting cones adjacent the teeth also may be fabricated with the nickel-based hardfacing. All other portions of the teeth are hardfaced with iron-based materials.
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TECHNICAL FIELD
[0001] The present invention concerns a continuous digester, according to the preamble of claim 1 .
STATE OF THE ART
[0002] In Prior Art for cooking of chemical cellulose pulp with continuous digesters it has been a well known practice to use a vertical digester vessel, with an established down-flow process developed in the vessel from the upper inlet end and down to the lower outlet end.
[0003] During the first 3 decades of implementation of such continuous digesters was a long countercurrent washing zone established in bottom of the digester, most often over some 40-50% of the total height of the digester. This type of cooking process is often recited as “conventional cooking”.
[0004] However, as higher production capacity came into demand this wash zone was reduced to only the final 5-10% of the total pulp retention time of the digester, while using more of the retention time in the digester for the actual cooking or delignification process. “Modified continuous cooking” was thus launched; having many variants such as ITC-cooking (Iso Thermal Cooking), EAPC-cooking (Enhanced Alkali Profile Cooking) etc.
[0005] Many of the old digesters, having been designed for “conventional cooking” or “Modified continuous cooking” also tried to increase production capacity, and this resulted in that the digester most often became overloaded, and the originally intended wash zone lost some of its function as a wash effect. Then some of the washing had to be done in subsequent wash equipment.
[0006] Attempts have been made to design and improve the bottom wash of the digester. As early as 1969 was U.S. Pat. No. 3,475,271 issued, where the wash zone was more or less inverted in relation to common wash zones. Common wash zones had extraction screens in the wall of the digester, while adding wash liquid to bottom via nozzle below the extraction screens or even integrated with the bottom scraper. In U.S. Pat. No. 3,475,271 the system was inverted, such that wash liquid was added via “distribution screens” in the wall of the digester, and having a tubular extraction screen co-rotating with the bottom scraper. However, this system was no success as it included a complicated and expensive tubular body as long as the digester itself and co-rotating with the bottom scraper. The tubular body also had to have a diameter in the range of ⅕ to ⅓ of the diameter of the digester vessel, which meant that a large volume of the digester was not used for the important cooking process, all in order for establishment of sufficient extraction screen area for being able to withdraw the volumes of spent liquor.
[0007] Similar tubular central screen body was also used in some smaller pin chip digesters installed in the early 70-ies. In a typical installation in a pin chip digester with total height of about 22 meter was the height of the tubular screen body about 7.5 meter, i.e. roughly ⅓ of the total digester height. The diameter of the screen body was about 1.5 meter in the vessel having a diameter of about 3.7 meter. This meant that a large volume of the total digester volume was not available for the cooking process and hence a low production capacity per volume unit of the digester.
[0008] The concept with central screen bodies was also shown in WO2005/116327 and WO2005/116328, but in these embodiments was the central screen body integrated with the stationary central pipe. As the screen body was implemented in the central pipe, having a relatively small diameter, a limited withdrawal capacity could be obtained.
[0009] The above mentioned disadvantages with central tubular screen bodies included spacious screen bodies reducing the total volume of the digester, and had only a reduced rubbing action from the descending chip column on the screen surface for maintaining this screen surface free from blocking objects (i.e. chips in differing state of delignification)
THE OBJECT AND PURPOSE OF THE INVENTION
[0010] The principle object of the invention is to obtain an improved withdrawal capacity in the bottom of the digester, while still not being spacious and reducing the available volume in the digester used for the cooking process.
[0011] A specific objective is to enable an improved wash zone in the bottom of the digester and especially for those digesters that are operating in an overloaded state such that the original wash effect in the bottom of the digester has disappeared. Thus suitable for an up-grade in those overloaded digesters.
[0012] Yet another specific objective is to be able to maintain a high withdrawal capacity in a relatively small screen area, by increasing the rubbing action from the descending pulp column keeping the draining apertures of the screen clean, which is made possible by exposing the screen area for an increased vertical downward thrust from the descending pulp column.
[0013] The invention can advantageously be used when cooking hard wood and softwood chips, bagasse and other annual plants.
SHORT DESCRIPTION OF THE INVENTION
[0014] The characteristics of the invention are defined by the independent claims, and optional embodiments are defined in dependent claims in order of dependency of preceding claims. The invention is also disclosed in a preferred embodiment, but any specific feature of this embodiment could as such be included in the invention optionally, if not specifically defined as a necessary feature for the argued effect.
DESCRIPTION OF DRAWINGS
[0015] FIG. 1 shows a continuous digester in its basic features according to prior art;
[0016] FIG. 2 shows a first embodiment of the cone diverter using circular drainage apertures;
[0017] FIG. 3 shows a second embodiment of the cone diverter using elongated slot-like drainage apertures;
[0018] FIG. 4 shows the principle drainage structure of the cone diverter;
[0019] FIG. 5 a shows a detail view of an embodiment with circular drainage apertures as seen from the pulp side;
[0020] FIG. 5 b shows a side view seen from section A-A in FIG. 5 a ; and
[0021] FIG. 6 shows a detail view of an embodiment with elongated slot-like drainage apertures as seen from the pulp side.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0022] FIG. 1 shows a typical design of a conventional continuous digester. The cellulose material CH IN is fed to the top of the digester vessel with additional charge of cooking chemicals WL. Excess liquor LIQ RET is withdrawn in a top separator via a first strainer section 60 and a pump 30 .
[0023] In a first cooking circulation comprising a strainer section 61 , pump 31 , heating device 40 and a central pipe 21 a is the cellulose material heated to the necessary cooking temperature and cooking chemicals WL is added.
[0024] The cellulose material is thereafter moving down in a plug flow concurrent with the flow of cooking chemicals trough the digesting zone until it reaches an extraction circulation which terminates the cooking zone. The extraction circulation comprises a strainer section 62 , here with 2 screen rows, pump 32 , and a central pipe 22 a. A larger part of the withdrawn and used treatment liquor is extracted from the digester and sent to recovery REC, or alternatively sent to any black liquor impregnation vessel preceding the cooking vessel.
[0025] Below the strainer section 62 of the extraction circulation is a counter current hi-heat washing zone established, and the cellulose material is moving down in a plug flow trough the washing zone until it reaches a wash circulation which terminates the hi-heat washing zone. The wash circulation comprises a strainer section 63 , here with 1 screen row, pump 33 , and a central pipe 23 a. As indicated is this wash circulation complemented with a heating device 41 .
[0026] As indicated in this drawing could also the wash circulation be complemented with an addition of cooking chemicals WL OPT , which then modifies the washing zone to a cooking zone.
[0027] Finally, cold wash and dilution liquid DL is added to the bottom of the digester via a number of vertical and horizontal nozzles, which results in a counter current wash displacement zone towards the wash circulation, in order to remove cooking chemicals and dissolved organic material, as well as lowering of the temperature of the pulp before out feed from the digester, and dilution of the pulp in order to facilitate out feed of digested cellulose material CH OUT .
[0028] In the bottom of the digester is in a conventional manner a bottom scraper arranged, comprising a drive shaft 70 , scraper arms 71 and a cone diverter 72 . The purpose of the cone diverter 72 is to force the central volume of the chip column towards the scraper arms, avoiding the risk for channelling inside the digester. Unless said cone diverter it may cause a non-uniform chip column movement as a more rapid flow in the centre of the digester may be developed towards the central outlet bucket 52 compared with chip column movement close to the digester walls.
[0029] While FIG. 1 only discloses the basic features of conventional continuous digester, it is to be understood that the system could be modified in a number of ways. For example, the number of circulations could be more than those shown in FIG. 1 . The heating devices 40 , 41 could either be heaters using direct heating with steam, i.e. mixing steam into the circulation, or heat exchangers.
[0030] In FIG. 2 is a detail view of the bottom scraper shown in FIG. 1 , but here modified according the inventive concept. The bottom scraper comprises the drive shaft 70 , the scraper arms 71 and a cone diverter 72 , all co-rotating as one common unit. The pulp descending down the vessel in a plug flow is broken up by the bottom scraper and paddles 73 push the pulp towards the outlet bucket 52 before being fed out via the blow line BL. During this process is dilution/wash liquid DL added via horizontal and vertical nozzles. The upper inclined surface of the cone diverter 72 has an inclination angle (α) in the range 30±10 degrees in relation to the vertical, here indicated as the centre line CL. According to the invention is the upper inclined surface equipped with draining apertures in fluid communication with a liquid receiving chamber CC inside the cone diverter, said liquid receiving chamber connected to a drainage channel 70 a to the exterior of said vessel. In this first embodiment are the draining apertures 80 drilled circular holes having the edges of the drainage apertures all aligned with the inclined surface of the cone diverter. The opening of the drainage apertures 80 have a smallest diameter less than 5 millimeter, but equal or larger than 1 millimeter, and the appropriate size is dependent on the type of wood material being fed to the digester. If ordinary sized chips are fed to the digester could larger holes be used in the recommended range 1-5 millimeter, preferably in the range 2-4 millimeter, than if saw dust or similar small fractions are fed to the digester. The total effective open area of the apertures in the cone diverter is typically in the range 10-30%, and preferably at least 15%.
[0031] In the bottom of the digester are typically narrower slots or bore holes used in any draining structures as the wood material is delignified to a great extent and thus more vulnerable for withdrawal compared to locating draining structures in the top of the digester.
[0032] As indicated in FIG. 2 is a displacement wash effect developed from the dilution/wash liquid nozzles and towards the drainage apertures in the upper inclined surface of the cone diverter 72 (indicated by broken arrows). This means that the added dilution/wash liquid DL will displace the liquid towards the apertures, and ideally should the displacement front end at the surface of the cone diverter such that the old liquid in the pulp is withdrawn and replaced with new fresh dilution/wash liquid DL. As indicated is also a part of the added liquid DL also flowing directly towards the outlet bucket 52 as well as towards the lowermost strainer section 63 a.
[0033] In FIG. 3 is a detail view of the bottom scraper shown in FIG. 1 , but here modified according the inventive concept but with drainage apertures in the cone diverter having an elongated slot like form. As indicated are rows of slots arranged over the the upper inclined surface of the cone diverter 72 . Also in this embodiment are the drainage apertures having a smallest width across the slot less than 5 millimeter, and preferably equal or larger than 1 millimeter. The length of the slots could vary in the range from 50 to 200 millimeters or even longer.
[0034] In FIG. 4 is the general drainage structure shown, which is similar to both embodiments shown in FIGS. 2 and 3 . Here the cone diverter 72 is seen in a vertical section view. When the drained liquid has passed the apertures of the upper inclined surface of the cone diverter, indicated with multiple arrows, all the drained liquid will be collected in a receiving chamber CC inside the cone diverter. The liquid receiving chamber CC is then connected at its bottom to a drainage channel 70 a to the exterior of said vessel. In this embodiment is the drainage channel 70 a located inside of the vertical drive shaft 70 of the bottom scraper, i.e. as a concentric bore trough said drive shaft. As indicated on the right hand side of the receiving chamber CC could the upper inclined surface of the cone diverter be supported by vertically oriented reinforcing ribs 72 a, here only one shown, but in a number sufficient to withstand the axial downward thrust from the pulp column. Alternatively could also horizontally oriented reinforcing rings be used between the ribs and the inclined surface of the cone diverter. As indicated with arrow RA is a rubbing action exposed to the inclined surface of the cone diverter and the apertures therein, and as the cone angel α is in the range 45±15 degrees in relation to the vertical is the downward thrust increasing proportionally to the increase of this cone angle. However a cone angel α of about 45 degrees is the optimum trade-off for obtaining a high rubbing effect as well as a smooth redirection of the central pulp volume towards the scraper arms avoiding channeling.
[0035] In FIG. 5 a is shown a detail view of an embodiment with circular drainage apertures 80 as seen from the pulp side. In FIG. 5 b is this embodiment seen in section A-A in FIG. 5 a , with the pulp side marked as PS and the liquid receiving chamber side marked as CC. The direction of rotation of the cone diverter surface is indicated by arrow ROT, and the trailing edges 81 b of the drainage apertures on the upper inclined surface of the cone diverter are recessed in relation to the inclined surface of the cone diverter in a direction towards the liquid receiving chamber CC.
[0036] The leading edges 81 a of the drainage apertures 80 on the upper inclined surface of the cone diverter 72 are at least aligned with the inclined surface of the cone diverter, but in this embodiment they are also elevated in relation to the inclined surface of the cone diverter in a direction away from the dilution/wash liquid DL
[0037] In this context the leading edge is the edge that is initially exposing the drainage aperture 80 for a new pulp volume as the cone diverter is rotating and the trailing edge is the edge that is closing the drainage aperture 80 for the pulp volume having being exposed to drainage by said drainage aperture. The design reassembles a cheese grater, but with no cutting edges directed towards the pulp volume inside the digester as the cone diverter rotates.
[0038] In FIG. 6 is shown a detail view of an embodiment with elongated slot-like drainage apertures 80 a, 80 b, 80 c as seen from the pulp side. Here are the slots arranged in rows, with an upper row with slots 80 a, an intermediate row with slots 80 b and a lower row with slots 80 c. The number of rows are used is dependent on the height of the cone diverter, i.e. size and capacity of the digester, as well as the length of extension of each slot. Preferably could also the slots have a width that is slightly increasing towards the liquid receiving chamber CC, i.e. if the slot width at the pulp side is 4 millimeter then the slot width at the side towards the liquid receiving chamber CC could be some 0.1 to 0.5 millimeter wider. This in order to let pass any obstacle trough the apertures if initially trapped in the slots and thus avoiding permanent blockage.
[0039] As to the lower end of each slot it could preferably have an inclined end surface, such that this end surface is closer to the strict horizontal location, i.e. the end surface at an angle (90°-α), or even with less inclination angle (α being the cone diverter angle as indicated in FIG. 2 ). This in order to establish a sloping surface such that obstacles caught against the slots in their upper slot part, and rubbed against the entire slot length, may be pushed out from the lower end of the slot.
[0040] The invention could be altered in many ways under the inventive scope as defined in claims. Whether or not circular holes or slots should be used is a matter of convenience for production and keeping manufacturing costs low. Slots could preferably be made using water or laser cutting techniques.
[0041] The invention could also be combined with a dilution scraper, i.e. a scraper adding dilution liquid also via its arms. In such embodiment could preferably dilution liquid be added as well via the drive shaft of the bottom scraper, but in a separate supply channel, preferably in form of a coaxial outer channel. Such a supply of dilution liquid to the arms of the bottom scraper could also be used to back flush the apertures via any appropriate controllable valve means.
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The continuous digester is for producing pulp from comminuted cellulosic material. The digester has a cone diverter on a bottom scraper arranged in the bottom of the digester for assisting in out feed of pulp produced. The cone diverter of the bottom scraper has an upper inclined surface of the cone diverter with an inclination angle in the range 30±10 degrees in relation to the vertical. In order to improve washing performance in the bottom of the digester, especially for overloaded digesters, the upper inclined surface is equipped with draining apertures in fluid communication with a liquid receiving chamber inside the cone diverter. The liquid receiving chamber is connected via a drainage channel to the exterior of the vessel.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 14/157,971, filed Jan. 17, 2014, now U.S. Pat. No. 8,945,441, which is a division of U.S. patent application Ser. No. 13/834,454, filed Mar. 15, 2013, now U.S. Pat. No. 8,662,878, which is a continuation of U.S. patent application Ser. No. 13/354,046, filed Jan. 19, 2012, now U.S. Pat. No. 8,439,666, which is a continuation of U.S. patent application Ser. No. 11/633,763, filed Dec. 4, 2006, now U.S. Pat. No. 8,128,393, each of which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
Generally, the present invention relates to materials and methods for fabricating molds having nano-sized cavities for molding nanoparticles therein. More particularly, the molds include laminated layers of polymeric materials and can include arrays of nano-sized cavities of predetermined shapes.
ABBREVIATIONS
AC=alternating current
Ar=Argon
° C.=degrees Celsius
cm=centimeter
8-CNVE=perfluoro(8-cyano-5-methyl-3,6-dioxa-1-octene)
CSM=cure site monomer
CTFE=chlorotrifluoroethylene
g=grams
h=hours
1-HPFP=1,2,3,3,3-pentafluoropropene
2-HPFP=1,1,3,3,3-pentafluoropropene
HFP=hexafluoropropylene
HMDS=hexamethyldisilazane
IL=imprint lithography
IPDI=isophorone diisocyanate
MCP=microcontact printing
Me=methyl
MEA=membrane electrode assembly
MEMS=micro-electro-mechanical system
MeOH=methanol
MIMIC=micro-molding in capillaries
mL=milliliters
mm=millimeters
mmol=millimoles
M n =number-average molar mass
m.p.=melting point
mW=milliwatts
NCM=nano-contact molding
NIL=nanoimprint lithography
nm=nanometers
Pd=palladium
PAVE perfluoro(alkyl vinyl) ether
PDMS=poly(dimethylsiloxane)
PEM=proton exchange membrane
PFPE=perfluoropolyether
PMVE perfluoro(methyl vinyl) ether
PPVE perfluoro(propyl vinyl) ether
PSEPVE=perfluoro-2-(2-fluorosulfonylethoxyl)propyl vinyl ether
PTFE=polytetrafluoroethylene
SAMIM=solvent-assisted micro-molding
SEM=scanning electron microscopy
Si=silicon
TFE=tetrafluoroethylene
μm=micrometers
UV=ultraviolet
W=watts
BACKGROUND
Polymer materials have been used as molds and as laminate molds for many years. However, the typical polymer molds and laminate molds have many drawbacks with respect to the scale of what can be molded therein. Such drawbacks generally result from chemical and physical interaction between the materials of the molds and the materials being molded therein. Typically, as the structures to be molded are reduced in size and approach tens or hundreds of micrometers or less, the typical mold materials fail to perform as molds. These failures can include the failure to accept material into such mold cavities and failure to release, especially release cleanly, any materials that do enter the mold cavities. Therefore, there is a need in the art for materials that can form molds having cross-sectional dimensions of less than tens of micrometers, less than micrometers, and less than 500 nanometers that can accept materials into mold cavities and cleanly release materials molded therein. Furthermore, the smaller the feature sizes of the article being formed in the mold, the closer that feature size comes to defects and blemishes produced by the conventional molding materials and methods.
The applicants have previously disclosed PFPE based materials that overcome these drawbacks and disclose herein further methods, materials, and articles for overcoming such drawbacks.
SUMMARY
According to the present invention, a laminate nanomold includes a layer of perfluoropolyether, where the layer of perfluoropolyether defines a cavity having a predetermined shape and a support layer coupled with the layer of perfluoropolyether. In some embodiments, the laminate also includes a tie-layer coupling the layer of perfluoropolyether with the support layer. According to other embodiments, the tie-layer includes a photocurable component and a thermal curable component.
In some embodiments, the laminate further includes a plurality of cavities defined in the perfluoropolyether layer. Each cavity of the plurality of cavities can have a predetermined shape selected from the group of cylindrical, 200 nm diameter cylinders, cuboidal, 200 nm cuboidal, crescent, and concave disc. In some embodiments, the plurality of cavities includes cavities of a variety of predetermined shapes. According to alternative embodiments, each cavity of the plurality of cavities is less than about 10 micrometers in a largest dimension, less than about 5 micrometers in a largest dimension, less than about 1 micrometer in a largest dimension, less than about 750 nanometers in a largest dimension, less than about 500 nanometers in a largest dimension, less than about 300 nanometers in a largest dimension, less than about 200 nanometers in a largest dimension, less than about 100 nanometers in a largest dimension, less than about 75 nanometers in a largest dimension, less than about 50 nanometers in a largest dimension, less than about 40 nanometers in a largest dimension, less than about 30 nanometers in a largest dimension, less than about 20 nanometers in a largest dimension, or less than about 10 nanometers in a largest dimension.
According to other embodiments, the perfluoropolyether layer is less than about 50 micrometers thick, less than about 40 micrometers thick, less than about 30 micrometers thick, less than about 20 micrometers thick, less than about 15 micrometers thick, less than about 10 micrometers thick.
In some embodiments, the support layer includes a polymer. In other embodiments, the polymer of the support layer includes polyethylene terephthalate. In alternative embodiments, the support layer is less than about 20 mil thick, less than about 15 mil thick, less than about 10 mil thick, or less than about 5 mil thick.
In certain embodiments, the support layer introduces a modulus of greater than 1000 to the laminate. In other embodiments, the layer of perfluoropolyether is coupled with the support layer by photoinitiator coupling and thermalinitiator coupling. In some embodiments, the perfluoropolyether includes a photocurable component. In yet other embodiments, the layer of perfluoropolyether has a footprint greater than about 25 square centimeters, a footprint greater than about 50 square centimeters, or a footprint greater than about 100 square centimeters.
In some embodiments, each cavity of the plurality of cavities is less than about 5 micrometers from an adjacent cavity, less than about 2 micrometer from an adjacent cavity, less than about 1 micrometers from an adjacent cavity, less than about 750 nanometers from an adjacent cavity, or less than about 500 nanometers from an adjacent cavity. In some embodiments, the perfluoropolyether has less than about 10 percent sol fraction.
According to other embodiments of the present invention, a method of making a laminate nanomold includes positioning a patterned master adjacent to a support layer, inserting the positioned patterned master and adjacent support layer between nips of a roll laminator, delivering a curable perfluoropolyether between the patterned master and the support layer adjacent an input side of the roll laminator, activating the roll laminator to laminate the patterned master with the support layer, wherein the curable perfluoropolyether is dispersed between the patterned master and the support layer, and treating the laminate to activate a curable component of the curable perfluoropolyether such that the perfluoropolyether is solidified. In some embodiments, the method further includes, before positioning the patterned master adjacent the support layer, configuring a tie-layer with the support layer such that when activated the curable perfluoropolyether binds with the tie-layer.
According to further embodiments of the present invention, a laminate polymer mold includes a first polymer layer coupled to a second polymer layer by a tie-layer disposed between the first polymer layer and the second polymer layer, wherein the tie-layer includes a fluoropolymer having a photocurable component and a thermal curable component. In some embodiments, the polymer of the first or second layers includes a fluoropolymer. In other embodiments, the polymer of the first or second layers includes a perfluoropolyether. In further embodiments, the polymer of the first or second layers includes a polyethylene terephthalate. In still further embodiments, the fluoropolymer of the tie-layer includes a perfluoropolyether.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic of a laminate mold according to an embodiment of the present invention;
FIG. 2 is a schematic of a roll apparatus for fabricating a laminate mold according to an embodiment of the present invention;
FIG. 3 is a schematic of a roll apparatus for fabricating a laminate mold according to another embodiment of the present invention;
FIG. 4 is a schematic of separation of a laminate mold from a master template according to an embodiment of the present invention;
FIG. 5 is an SEM image of a top surface of a laminate mold having 200 nm cavities arranged in a hexagonal array according to an embodiment of the present invention;
FIG. 6 is an SEM image of a polymer replica fabricated from the laminate mold of FIG. 5 showing hexagonally arranged 200 nm posts formed from the 200 nm cavities of the laminate mold; and
FIGS. 7A and 7B are graphs showing sample IR data according to an embodiment of the present invention.
DETAILED DESCRIPTION
Generally, the present invention discloses laminate molds of varying polymer materials and methods of making such molds. The molds generally include arrays of nano-sized cavities formed with predetermined shapes and controlled spacing between the cavities.
I. NON-EXHAUSTIVE LIST OF DEFINITIONS
As used herein, the term “pattern” can mean an array, a matrix, specific shape or form, a template of the article of interest, or the like. In some embodiments, a pattern can be ordered, uniform, repetitious, alternating, regular, irregular, or random arrays or templates. The patterns of the present invention can include one or more of a micro- or nano-sized reservoir, a micro- or nano-sized reaction chamber, a micro- or nano-sized mixing chamber, a micro- or nano-sized collection chamber. The patterns of the present invention can also include a surface texture or a pattern on a surface that can include micro- and/or nano-sized cavities. The patterns can also include micro- or nano-sized projections.
As typical in polymer chemistry the term “perfluoropolyethers” herein should be understood to represent not only its purest form, i.e., the polymeric chain built from three elements—carbon, oxygen, and fluorine, but variations of such structures. The base family of perfluoropolyethers itself includes linear, branched, and functionalized materials. The use within this patent also includes some substitution of the fluorine with materials such as H, and other halides; as well as block or random copolymers to modify the base perfluoropolyethers.
As used herein, the term “monolithic” refers to a structure having or acting as a single, uniform structure.
As used herein, the term “non-biological organic materials” refers to organic materials, i.e., those compounds that include covalent carbon-carbon bonds, other than biological materials. As used herein, the term “biological materials” includes nucleic acid polymers (e.g., DNA, RNA) amino acid polymers (e.g., enzymes, proteins, and the like) and small organic compounds (e.g., steroids, hormones) wherein the small organic compounds have biological activity, especially biological activity for humans or commercially significant animals, such as pets and livestock, and where the small organic compounds are used primarily for therapeutic or diagnostic purposes. While biological materials are of interest with respect to pharmaceutical and biotechnological applications, a large number of applications involve chemical processes that are enhanced by other than biological materials, i.e., non-biological organic materials.
As used herein, the term “partial cure” refers to a condition wherein less than about 100% of a polymerizable group of a material is reacted. In certain embodiments, the term “partially-cured material” refers to a material that has undergone a partial cure process or treatment.
As used herein, the term “full cure” refers to a condition wherein about 100% of a polymerizable group of a material is reacted. In certain embodiments, the term “fully-cured material” refers to a material which has undergone a full cure process or treatment.
As used herein, the term “photocured” refers to a reaction of polymerizable groups whereby the reaction can be triggered by actinic radiation, such as UV light. In this application UV-cured can be a synonym for photocured.
As used herein, the term “thermal cure” or “thermally cured” refers to a reaction of polymerizable groups, whereby the reaction can be triggered or accelerated by heating the material beyond a threshold temperature.
Following long-standing patent law convention, the terms “a”, “an”, and “the” refer to “one or more” when used in this application, including the claims. Thus, for example, reference to “a cavity” includes a plurality of such cavities, and so forth.
II. MATERIALS
In certain embodiments, the present invention broadly describes and employs solvent resistant, low surface energy polymeric materials for fabricating articles or articles, such as molds having micro- and/or nano-sized cavities. According to some embodiments the low surface energy polymeric materials include, but are not limited to fluoropolyether or perfluoropolyether (collectively “PFPE”), poly(dimethylsiloxane) (PDMS), poly(tetramethylene oxide), poly(ethylene oxide), poly(oxetanes), polyisoprene, polybutadiene, fluoroolefin-based fluoroelastomers, and the like. An example of forming a mold with such materials includes casting liquid PFPE precursor materials onto a patterned substrate (or master) and then curing the liquid PFPE precursor materials to generate a replica pattern of the master. For simplification purposes, most of the description will focus on PFPE materials, however, it should be appreciated that other polymers, such as those recited herein, can be applied to the methods, materials, and articles of the present invention.
According to certain embodiments of the present invention, “curing” a liquid polymer, for example a liquid PFPE precursor, means transforming the polymer from a liquid state to a non-liquid state (excluding a gas state) such that the polymer does not readily flow, such as a material with a relatively high viscosity or a rubbery state. In some embodiments, the non-liquid state that the polymer is transformed to is a gel state. In some embodiments, the polymer in the non-liquid state can include un-reacted polymerizable groups. In other embodiments, the polymer liquid precursor is capable of undergoing a first cure to become non-liquid such that the polymer becomes not fully soluble in a solvent. In other embodiments, when the liquid polymer precursor is cured it is meant that the polymer has transitioned into a non-liquid polymer that forms fibers about an object drawn through the material. In other embodiments, an initial cure of the liquid polymer precursor transitions the polymer to a non-conformable state at room temperature. In other embodiments, following a cure, the polymer takes a gel form, wherein gel means an article that is free-standing or self-supporting in that its yield value is greater than the shear stress imposed by gravity.
Representative solvent resistant elastomer-based materials include but are not limited to fluorinated elastomer-based materials. As used herein, the term “solvent resistant” refers to a material, such as an elastomeric material that does not substantially swell or dissolve in common hydrocarbon-based organic solvents or acidic or basic aqueous solutions. Representative fluorinated elastomer-based materials include but are not limited to fluoropolyether and perfluoropolyether (collectively “PFPE”) based materials.
In certain embodiments, functional liquid PFPE materials exhibit desirable properties for use in a micro- or nano-sized molds. For example, functional PFPE materials typically have one or more of the following characteristics: low surface energy, are non-toxic, UV and visible light transparent, highly gas permeable, cure into a tough, durable, highly fluorinated elastomeric or glassy materials with excellent release properties, resistant to swelling, solvent resistant, biocompatible, non-reactive surfaces, combinations thereof, and the like. The properties of these materials can be tuned over a wide range through the judicious choice of additives, fillers, reactive co-monomers, and functionalization agents, examples of which are described further herein. Such properties that are desirable to modify, include, but are not limited to, modulus, tear strength, surface energy, permeability, functionality, mode of cure, solubility, toughness, hardness, elasticity, swelling characteristics, absorption, adsorption, combinations thereof, and the like.
Some examples of methods of adjusting mechanical and or chemical properties of the finished material includes, but are not limited to, shortening the molecular weight between cross-links to increase the modulus of the material, adding monomers that form polymers of high Tg to increase the modulus of the material, adding charged monomer or species to the material to increase the surface energy or wetability of the material, combinations thereof, and the like.
According to one embodiment, materials for use herein (e.g., PFPE materials) have surface energy below about 30 mN/m. According to another embodiment the surface energy is between about 7 mN/m and about 20 mN/m. According to a more preferred embodiment, the surface energy is between about 10 mN/m and about 15 mN/m. The non-swelling nature and easy release properties of the presently disclosed materials (e.g. PFPE materials) allow for the fabrication of laminate articles.
II.A. Perfluoropolyether Materials Prepared from a Liquid PFPE Precursor Material Having a Viscosity Less Than About 100 Centistokes
As would be recognized by one of ordinary skill in the art, perfluoropolyethers (PFPEs) have been in use for over 25 years for many applications. Commercial PFPE materials are made by polymerization of perfluorinated monomers. The first member of this class was made by the cesium fluoride catalyzed polymerization of hexafluoropropene oxide (HFPO) yielding a series of branched polymers designated as KRYTOX® (DuPont, Wilmington, Del., United States of America). A similar polymer is produced by the UV catalyzed photo-oxidation of hexafluoropropene (FOMBLIN® Y) (Solvay Solexis, Brussels, Belgium). Further, a linear polymer (FOMBLIN® Z) (Solvay) is prepared by a similar process, but utilizing tetrafluoroethylene. Finally, a fourth polymer (DEMNUM®) (Daikin Industries, Ltd., Osaka, Japan) is produced by polymerization of tetrafluorooxetane followed by direct fluorination. Structures for these fluids are presented in Table I. Table II contains property data for some members of the PFPE class of lubricants. Likewise, the physical properties of functional PFPEs are provided in Table III. In addition to these commercially available PFPE fluids, a new series of structures are being prepared by direct fluorination technology. Representative structures of these new PFPE materials appear in Table IV. Of the abovementioned PFPE fluids, only KRYTOX® and FOMBLIN® Z have been extensively used in applications. See Jones, W. R., Jr., The Properties of Perfluoropolyethers Used for Space Applications, NASA Technical Memorandum 106275 (July 1993), which is incorporated herein by reference in its entirety. Accordingly, the use of such PFPE materials is provided in the presently disclosed subject matter.
TABLE I
NAMES AND CHEMICAL STRUCTURES OF
COMMERCIAL PFPE FLUIDS
NAME
Structure
DEMNUM ®
C 3 F 7 O(CF 2 CF 2 CF 2 O) x C 2 F 5
KRYTOX ®
C 3 F 7 O[CF(CF 3 )CF 2 O] x C 2 F 5
FOMBLIN ® Y
C 3 F 7 O[CF(CF 3 )CF 2 O] x (CF 2 O) y C 2 F 5
FOMBLIN ® Z
CF 3 O(CF 2 CF 2 O) x (CF 2 O) y CF 3
TABLE II
PFPE PHYSICAL PROPERTIES
Average
Viscosity
Molec-
at
Vis-
Pour
Vapor Pressure,
ular
20° C.,
cosity
Point,
Torr
Lubricant
Weight
(cSt)
Index
° C.
20° C.
100° C.
FOMBLIN ®
9500
255
355
−66
2.9 × 10 −12
1 × 10 −8
Z-25
KRYTOX ®
3700
230
113
−40
1.5 × 10 −6
3 × 10 −4
143AB
KRYTOX ®
6250
800
134
−35
2 × 10 −8
8 × 10 −6
143AC
DEMNUM ®
8400
500
210
−53
1 × 10 −10
1 × 10 −7
S-200
TABLE III
PFPE PHYSICAL PROPERTIES OF FUNCTIONAL PFPES
Average
Viscosity
Molecular
at 20° C.,
Vapor Pressure, Torr
Lubricant
Weight
(cSt)
20° C.
100° C.
FOMBLIN ®
2000
85
2.0 × 10 −5
2.0 × 10 −5
Z-DOL 2000
FOMBLIN ®
2500
76
1.0 × 10 −7
1.0 × 10 −4
Z-DOL 2500
FOMBLIN ®
4000
100
1.0 × 10 −8
1.0 × 10 −4
Z-DOL 4000
FOMBLIN ®
500
2000
5.0 × 10 −7
2.0 × 10 −4
Z-TETROL
TABLE IV
Names and Chemical Structures of Representative PFPE Fluids
Name
Structure a
Perfluoropoly(methylene oxide) (PMO)
CF 3 O(CF 2 O) x CF 3
Perfluoropoly(ethylene oxide) (PEO)
CF 3 O(CF 2 CF 2 O) x CF 3
Perfluoropoly(dioxolane) (DIOX)
CF 3 O(CF 2 CF 2 OCF 2 O) x CF 3
Perfluoropoly(trioxocane) (TRIOX)
CF 3 O[(CF 2 CF 2 O) 2 CF 2 O] x CF 3
a wherein x is any integer.
In some embodiments, the perfluoropolyether precursor includes poly(tetrafluoroethylene oxide-co-difluoromethylene oxide)α,ω diol, which in some embodiments can be photocured to form one of a perfluoropolyether dimethacrylate and a perfluoropolyether distyrenic compound. A representative scheme for the synthesis and photocuring of a functionalized perfluoropolyether is provided in Scheme 1.
II.B. Perfluoropolyether Materials Prepared from a Liquid PFPE Precursor Material Having a Viscosity Greater than about 100 Centistokes
The methods provided herein below for promoting and/or increasing adhesion between a layer of a PFPE material and another material and/or a substrate and for adding a chemical functionality to a surface include a PFPE material having a characteristic selected from the group including, but not limited to a viscosity greater than about 100 centistokes (cSt) and a viscosity less than about 100 cSt, provided that the liquid PFPE precursor material having a viscosity less than 100 cSt is not a free-radically photocurable PFPE material. As provided herein, the viscosity of a liquid PFPE precursor material refers to the viscosity of that material prior to functionalization, e.g., functionalization with a methacrylate or a styrenic group.
Thus, in some embodiments, PFPE material is prepared from a liquid PFPE precursor material having a viscosity greater than about 100 centistokes (cSt). In some embodiments, the liquid PFPE precursor is end-capped with a polymerizable group. In some embodiments, the polymerizable group is selected from the group including, but not limited to an acrylate, a methacrylate, an epoxy, an amino, a carboxylic, an anhydride, a maleimide, an isocyanato, an olefinic, and a styrenic group.
In some embodiments, the PFPE material includes a backbone structure selected from the group including, but not limited to:
wherein X is present or absent, and when present includes an endcapping group, and n is an integer from 1 to 100.
In some embodiments, the PFPE liquid precursor is synthesized from hexafluoropropylene oxide or tetrafluoro ethylene oxide as shown in Scheme 2.
In some embodiments, the liquid PFPE precursor is synthesized from hexafluoropropylene oxide or tetrafluoro ethylene oxide as shown in Scheme 3.
In some embodiments the liquid PFPE precursor includes a chain extended material such that two or more chains are linked together before adding polymerizable groups. Accordingly, in some embodiments, a “linker group” joins two chains to one molecule. In some embodiments, as shown in Scheme 4, the linker group joins three or more chains.
In some embodiments, X is selected from the group including, but not limited to an isocyanate, an acid chloride, an epoxy, and a halogen. In some embodiments, R is selected from the group including, but not limited to an acrylate, a methacrylate, a styrene, an epoxy, a carboxylic, an anhydride, a maleimide, an isocyanate, an olefinic, and an amine. In some embodiments, the circle represents any multifunctional molecule. In some embodiments, the multifunctional molecule includes a cyclic molecule. PFPE refers to any PFPE material provided herein.
In some embodiments, the liquid PFPE precursor includes a hyperbranched polymer as provided in Scheme 5, wherein PFPE refers to any PFPE material provided herein.
In some embodiments, the liquid PFPE material includes an end-functionalized material selected from the group including, but not limited to:
In some embodiments the PFPE liquid precursor is encapped with an epoxy moiety that can be photocured using a photoacid generator. Photoacid generators suitable for use in the presently disclosed subject matter include, but are not limited to: bis(4-tert-butylphenyl)iodonium p-toluenesulfonate, bis(4-tert-butylphenyl)iodonium triflate, (4-bromophenyl)diphenylsulfonium triflate, (tert-butoxycarbonylmethoxynaphthyl)-diphenylsulfonium triflate, (tert-butoxycarbonylmethoxyphenyl)diphenylsulfonium triflate, (4-tert-butylphenyl)diphenylsulfonium triflate, (4-chlorophenyl)diphenylsulfonium triflate, diphenyliodonium-9,10-dimethoxyanthracene-2-sulfonate, diphenyliodonium hexafluorophosphate, diphenyliodonium nitrate, diphenyliodonium perfluoro-1-butanesulfonate, diphenyliodonium p-toluenesulfonate, diphenyliodonium triflate, (4-fluorophenyl)diphenylsulfonium triflate, N-hydroxynaphthalimide triflate, N-hydroxy-5-norbornene-2,3-dicarboximide perfluoro-1-butanesulfonate, N-hydroxyphthalimide triflate, [4-[(2-hydroxytetradecyl)oxy]phenyl]phenyliodonium hexafluoroantimonate, (4-iodophenyl)diphenylsulfonium triflate, (4-methoxyphenyl)diphenylsulfonium triflate, 2-(4-methoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine, (4-methylphenyl)diphenylsulfonium triflate, (4-methylthiophenyl)methyl phenyl sulfonium triflate, 2-naphthyl diphenylsulfonium triflate, (4-phenoxyphenyl)diphenylsulfonium triflate, (4-phenylthiophenyl)diphenylsulfonium triflate, thiobis(triphenyl sulfonium hexafluorophosphate), triarylsulfonium hexafluoroantimonate salts, triarylsulfonium hexafluorophosphate salts, triphenylsulfonium perfluoro-1-butanesufonate, triphenylsulfonium triflate, tris(4-tert-butylphenyl)sulfonium perfluoro-1-butanesulfonate, and tris(4-tert-butylphenyl)sulfonium triflate.
In some embodiments the liquid PFPE precursor cures into a highly UV and/or highly visible light transparent elastomer. In some embodiments the liquid PFPE precursor cures into an elastomer that is highly permeable to oxygen, carbon dioxide, and nitrogen, a property that can facilitate maintaining the viability of biological fluids/cells disposed therein. In some embodiments, additives are added or layers are created to enhance the barrier properties of the articles to molecules, such as oxygen, carbon dioxide, nitrogen, dyes, reagents, and the like.
In some embodiments, the material suitable for use with the presently disclosed subject matter includes a silicone material having a fluoroalkyl functionalized polydimethylsiloxane (PDMS) having the following structure:
wherein:
R is selected from the group including, but not limited to an acrylate, a methacrylate, and a vinyl group;
R f includes a fluoroalkyl chain; and
n is an integer from 1 to 100,000.
In some embodiments, the material suitable for use with the presently disclosed subject matter includes a styrenic material having a fluorinated styrene monomer selected from the group including, but not limited to:
wherein R f includes a fluoroalkyl chain.
In some embodiments, the material suitable for use with the presently disclosed subject matter includes an acrylate material having a fluorinated acrylate or a fluorinated methacrylate having the following structure:
wherein:
R is selected from the group including, but not limited to H, alkyl, substituted alkyl, aryl, and substituted aryl; and
R f includes a fluoroalkyl chain with a —CH 2 — or a —CH 2 —CH 2 — spacer between a perfluoroalkyl chain and the ester linkage. In some embodiments, the perfluoroalkyl group has hydrogen substituents.
In some embodiments, the material suitable for use with the presently disclosed subject matter includes a triazine fluoropolymer having a fluorinated monomer.
In some embodiments, the fluorinated monomer or fluorinated oligomer that can be polymerized or crosslinked by a metathesis polymerization reaction includes a functionalized olefin. In some embodiments, the functionalized olefin includes a functionalized cyclic olefin.
According to an alternative embodiment, the PFPE material includes a urethane block as described and shown in the following structures provided in Scheme 6:
According to an embodiment of the present invention, PFPE urethane tetrafunctional methacrylate materials such as the above described can be used as the materials and methods of the present invention or can be used in combination with other materials and methods described herein, as will be appreciated by one of ordinary skill in the art.
According to some embodiments, urethane systems include materials with the following structures.
According to this scheme, part A is a UV curable precursor and parts B and C make up a thermally curable component of the urethane system. The fourth component, part D, is an end-capped precursor, (e.g., styrene end-capped liquid precursor). According to some embodiments, part D reacts with latent methacrylate, acrylate, or styrene groups contained in a base material, thereby adding chemical compatibility or a surface passivation to the base material and increasing the functionality of the base material.
II.C. Fluoroolefin-Based Materials
Further, in some embodiments, the materials used herein are selected from highly fluorinated fluoroelastomers, e.g., fluoroelastomers having at least fifty-eight weight percent fluorine, as described in U.S. Pat. No. 6,512,063 to Tang, which is incorporated herein by reference in its entirety. Such fluoroelastomers can be partially fluorinated or perfluorinated and can contain between 25 to 70 weight percent, based on the weight of the fluoroelastomer, of copolymerized units of a first monomer, e.g., vinylidene fluoride (VF 2 ) or tetrafluoroethylene (TFE). The remaining units of the fluoroelastomers include one or more additional copolymerized monomers, that are different from the first monomer, and are selected from the group including, but not limited to fluorine-containing olefins, fluorine containing vinyl ethers, hydrocarbon olefins, and combinations thereof.
These fluoroelastomers include VITON® (DuPont Dow Elastomers, Wilmington, Del., United States of America) and Kel-F type polymers, as described in U.S. Pat. No. 6,408,878 to Unger et al. These commercially available polymers, however, have Mooney viscosities ranging from about 40 to 65 (ML 1+10 at 121° C.) giving them a tacky, gum-like viscosity. When cured, they become a stiff, opaque solid. As currently available, VITON® and Kel-F have limited utility for micro-scale molding. Curable species of similar compositions, but having lower viscosity and greater optical clarity, is needed in the art for the applications described herein. A lower viscosity (e.g., 2 to 32 (ML 1+10 at 121° C.)) or more preferably as low as 80 to 2000 cSt at 20° C., composition yields a pourable liquid with a more efficient cure.
More particularly, the fluorine-containing olefins include, but are not limited to, vinylidine fluoride, hexafluoropropylene (HFP), tetrafluoroethylene (TFE), 1,2,3,3,3-pentafluoropropene (1-HPFP), chlorotrifluoroethylene (CTFE) and vinyl fluoride.
The fluorine-containing vinyl ethers include, but are not limited to perfluoro(alkyl vinyl) ethers (PAVEs). More particularly, perfluoro(alkyl vinyl) ethers for use as monomers include perfluoro(alkyl vinyl) ethers of the following formula:
CF 2 ═CFO(R f O) n (R f O) m R f
wherein each R f is independently a linear or branched C 1 -C 6 perfluoroalkylene group, and m and n are each independently an integer from 0 to 10.
In some embodiments, the perfluoro(alkyl vinyl) ether includes a monomer of the following formula:
CF 2 ═CFO(CF 2 CFXO) n R f
wherein X is F or CF 3 , n is an integer from 0 to 5, and R f is a linear or branched C 1 -C 6 perfluoroalkylene group. In some embodiments, n is 0 or 1 and R f includes 1 to 3 carbon atoms. Representative examples of such perfluoro(alkyl vinyl) ethers include perfluoro(methyl vinyl) ether (PMVE) and perfluoro(propyl vinyl) ether (PPVE).
In some embodiments, the perfluoro(alkyl vinyl) ether includes a monomer of the following formula:
CF 2 ═CFO[(CF 2 ) m CF 2 CFZO) n R f
wherein R f is a perfluoroalkyl group having 1-6 carbon atoms, m is an integer from 0 or 1, n is an integer from 0 to 5, and Z is F or CF 3 . In some embodiments, R f is C 3 F 7 , m is 0, and n is 1.
In some embodiments, the perfluoro(alkyl vinyl) ether monomers include compounds of the formula:
CF 2 ═CFO[(CF 2 CF{CF 3 }O) n (CF 2 CF 2 CF 2 O) m (CF 2 ) p ]C x F 2x+1
wherein m and n each integers independently from 0 to 10, p is an integer from 0 to 3, and x is an integer from 1 to 5. In some embodiments, n is 0 or 1, m is 0 or 1, and x is 1.
Other examples of useful perfluoro(alkyl vinyl ethers) include:
CF 2 ═CFOCF 2 CF(CF 3 )O(CF 2 ) m C n F 2n+1
wherein n is an integer from 1 to 5, m is an integer from 1 to 3. In some embodiments, n is 1.
In embodiments wherein copolymerized units of a perfluoro(alkyl vinyl) ether (PAVE) are present in the presently described fluoroelastomers, the PAVE content generally ranges from 25 to 75 weight percent, based on the total weight of the fluoroelastomer. If the PAVE is perfluoro(methyl vinyl) ether (PMVE), then the fluoroelastomer contains between 30 and 55 wt. % copolymerized PMVE units.
Hydrocarbon olefins useful in the presently described fluoroelastomers include, but are not limited to ethylene (E) and propylene (P). In embodiments wherein copolymerized units of a hydrocarbon olefin are present in the presently described fluoroelastomers, the hydrocarbon olefin content is generally 4 to 30 weight percent.
Further, the presently described fluoroelastomers can, in some embodiments, include units of one or more cure site monomers. Examples of suitable cure site monomers include: i) bromine-containing olefins; ii) iodine-containing olefins; iii) bromine-containing vinyl ethers; iv) iodine-containing vinyl ethers; v) fluorine-containing olefins having a nitrile group; vi) fluorine-containing vinyl ethers having a nitrile group; vii) 1,1,3,3,3-pentafluoropropene (2-HPFP); viii) perfluoro(2-phenoxypropyl vinyl) ether; and ix) non-conjugated dienes.
In certain embodiments, the brominated cure site monomers can contain other halogens, preferably fluorine. Examples of brominated olefin cure site monomers are CF 2 ═CFOCF 2 CF 2 CF 2 OCF 2 CF 2 Br; bromotrifluoroethylene; 4-bromo-3,3,4,4-tetrafluorobutene-1 (BTFB); and others such as vinyl bromide, 1-bromo-2,2-difluoroethylene; perfluoroallyl bromide; 4-bromo-1,1,2-trifluorobutene-1; 4-bromo-1,1,3,3,4,4,-hexafluorobutene; 4-bromo-3-chloro-1,1,3,4,4-pentafluorobutene; 6-bromo-5,5,6,6-tetrafluorohexene; 4-bromoperfluorobutene-1 and 3,3-difluoroallyl bromide. Brominated vinyl ether cure site monomers include 2-bromo-perfluoroethyl perfluorovinyl ether and fluorinated compounds of the class CF 2 Br—R f —O—CF═CF 2 (wherein R f is a perfluoroalkylene group), such as CF 2 BrCF 2 O—CF═CF 2 , and fluorovinyl ethers of the class ROCF═CFBr or ROCBr═CF 2 (wherein R is a lower alkyl group or fluoroalkyl group), such as CH 3 OCF═CFBr or CF 3 CH 2 OCF═CFBr.
Suitable iodinated cure site monomers include iodinated olefins of the formula: CHR═CH—Z—CH 2 CHR—I, wherein R is —H or —CH 3 ; Z is a C 1 to C 18 (per)fluoroalkylene radical, linear or branched, optionally containing one or more ether oxygen atoms, or a (per)fluoropolyoxyalkylene radical as disclosed in U.S. Pat. No. 5,674,959. Other examples of useful iodinated cure site monomers are unsaturated ethers of the formula: I(CH 2 CF 2 CF 2 ) n OCF═CF 2 and ICH 2 CF 2 O[CF(CF 3 )CF 2 O] n CF═CF 2 , and the like, wherein n is an integer from 1 to 3, such as disclosed in U.S. Pat. No. 5,717,036. In addition, suitable iodinated cure site monomers including iodoethylene, 4-iodo-3,3,4,4-tetrafluorobutene-1 (ITFB); 3-chloro-4-iodo-3,4,4-trifluorobutene; 2-iodo-1,1,2,2-tetrafluoro-1-(vinyloxy)ethane; 2-iodo-1-(perfluorovinyloxy)-1,1,-2,2-tetrafluoroethylene; 1,1,2,3,3,3-hexafluoro-2-iodo-1-(perfluorovinyloxy)propane; 2-iodoethyl vinyl ether; 3,3,4,5,5,5-hexafluoro-4-iodopentene; and iodotrifluoroethylene are disclosed in U.S. Pat. No. 4,694,045. Allyl iodide and 2-iodo-perfluoroethyl perfluorovinyl ether also are useful cure site monomers.
Useful nitrile-containing cure site monomers include, but are not limited to those of the formulas shown below:
CF 2 ═CF—O(CF 2 ) n —CN
wherein n is an integer from 2 to 12. In some embodiments, n is an integer from 2 to 6.
CF 2 ═CF—O[CF 2 —CF(CF)—O] n —CF 2 —CF(CF 3 )—CN
wherein n is an integer from 0 to 4. In some embodiments, n is an integer from 0 to 2.
CF 2 ═CF—[OCF 2 CF(CF 3 )] x —O—(CF 2 ) n —CN
wherein x is 1 or 2, and n is an integer from 1 to 4; and
CF 2 ═CF—O—(CF 2 ) n —O—CF(CF 3 )—CN
wherein n is an integer from 2 to 4. In some embodiments, the cure site monomers are perfluorinated polyethers having a nitrile group and a trifluorovinyl ether group.
In some embodiments, the cure site monomer is:
CF 2 ═CFOCF 2 CF(CF 3 )OCF 2 CF 2 CN
i.e., perfluoro(8-cyano-5-methyl-3,6-dioxa-1-octene) or 8-CNVE.
Examples of non-conjugated diene cure site monomers include, but are not limited to 1,4-pentadiene; 1,5-hexadiene; 1,7-octadiene; 3,3,4,4-tetrafluoro-1,5-hexadiene; and others, such as those disclosed in Canadian Patent No. 2,067,891 and European Patent No. 0784064A1. A suitable triene is 8-methyl-4-ethylidene-1,7-octadiene.
In embodiments wherein the fluoroelastomer will be cured with peroxide, the cure site monomer is preferably selected from the group including, but not limited to 4-bromo-3,3,4,4-tetrafluorobutene-1 (BTFB); 4-iodo-3,3,4,4-tetrafluorobutene-1 (ITFB); allyl iodide; bromotrifluoroethylene and 8-CNVE. In embodiments wherein the fluoroelastomer will be cured with a polyol, 2-HPFP or perfluoro(2-phenoxypropyl vinyl) ether is the preferred cure site monomer. In embodiments wherein the fluoroelastomer will be cured with a tetraamine, bis(aminophenol) or bis(thioaminophenol), 8-CNVE is the preferred cure site monomer.
Units of cure site monomer, when present in the presently disclosed fluoroelastomers, are typically present at a level of 0.05-10 wt. % (based on the total weight of fluoroelastomer), preferably 0.05-5 wt. % and most preferably between 0.05 and 3 wt. %.
Fluoroelastomers which can be used in the presently disclosed subject matter include, but are not limited to, those having at least 58 wt. % fluorine and having copolymerized units of i) vinylidene fluoride and hexafluoropropylene; ii) vinylidene fluoride, hexafluoropropylene and tetrafluoroethylene; iii) vinylidene fluoride, hexafluoropropylene, tetrafluoroethylene and 4-bromo-3,3,4,4-tetrafluorobutene-1; iv) vinylidene fluoride, hexafluoropropylene, tetrafluoroethylene and 4-iodo-3,3,4,4-tetrafluorobutene-1; v) vinylidene fluoride, perfluoro(methyl vinyl) ether, tetrafluoroethylene and 4-bromo-3,3,4,4-tetrafluorobutene-1; vi) vinylidene fluoride, perfluoro(methyl vinyl) ether, tetrafluoroethylene and 4-iodo-3,3,4,4-tetrafluorobutene-1; vii) vinylidene fluoride, perfluoro(methyl vinyl) ether, tetrafluoroethylene and 1,1,3,3,3-pentafluoropropene; viii) tetrafluoroethylene, perfluoro(methyl vinyl) ether and ethylene; ix) tetrafluoroethylene, perfluoro(methyl vinyl) ether, ethylene and 4-bromo-3,3,4,4-tetrafluorobutene-1; x) tetrafluoroethylene, perfluoro(methyl vinyl) ether, ethylene and 4-iodo-3,3,4,4-tetrafluorobutene-1; xi) tetrafluoroethylene, propylene and vinylidene fluoride; xii) tetrafluoroethylene and perfluoro(methyl vinyl) ether; xiii) tetrafluoroethylene, perfluoro(methyl vinyl) ether and perfluoro(8-cyano-5-methyl-3,6-dioxa-1-octene); xiv) tetrafluoroethylene, perfluoro(methyl vinyl) ether and 4-bromo-3,3,4,4-tetrafluorobutene-1; xv) tetrafluoroethylene, perfluoro(methyl vinyl) ether and 4-iodo-3,3,4,4-tetrafluorobutene-1; and xvi) tetrafluoroethylene, perfluoro(methyl vinyl) ether and perfluoro(2-phenoxypropyl vinyl) ether.
Additionally, iodine-containing endgroups, bromine-containing endgroups or combinations thereof can optionally be present at one or both of the fluoroelastomer polymer chain ends as a result of the use of chain transfer or molecular weight regulating agents during preparation of the fluoroelastomers. The amount of chain transfer agent, when employed, is calculated to result in an iodine or bromine level in the fluoroelastomer in the range of 0.005-5 wt. %, preferably 0.05-3 wt. %.
Examples of chain transfer agents include iodine-containing compounds that result in incorporation of bound iodine at one or both ends of the polymer molecules. Methylene iodide; 1,4-diiodoperfluoro-n-butane; and 1,6-diiodo-3,3,4,4-tetrafluorohexane are representative of such agents. Other iodinated chain transfer agents include 1,3-diiodoperfluoropropane; 1,6-diiodoperfluorohexane; 1,3-diiodo-2-chloroperfluoropropane; 1,2-di(iododifluoromethyl)perfluorocyclobutane; monoiodoperfluoroethane; monoiodoperfluorobutane; 2-iodo-1-hydroperfluoroethane, and the like. Also included are the cyano-iodine chain transfer agents disclosed European Patent No. 0868447A1. Particularly preferred are diiodinated chain transfer agents.
Examples of brominated chain transfer agents include 1-bromo-2-iodoperfluoroethane; 1-bromo-3-iodoperfluoropropane; 1-iodo-2-bromo-1,1-difluoroethane and others such as disclosed in U.S. Pat. No. 5,151,492.
Other chain transfer agents suitable for use include those disclosed in U.S. Pat. No. 3,707,529. Examples of such agents include isopropanol, diethylmalonate, ethyl acetate, carbon tetrachloride, acetone and dodecyl mercaptan.
II.D. Dual Photo-Curable and Thermal-Curable Materials
According to other embodiments of the present invention, a dual cure material includes one or more of a photo-curable constituent and a thermal-curable constituent. In one embodiment, the photo-curable constituent is independent from the thermal-curable constituent such that the material can undergo multiple cures. A material having the ability to undergo multiple cures is useful, for example, in forming layered articles or in connecting or attaching articles to other articles or portions or components of articles to other portions or components of articles. For example, a liquid material having photocurable and thermal-curable constituents can undergo a first cure to form a first article through, for example, a photocuring process or a thermal curing process. Then the photocured or thermal cured first article can be adhered to a second article of the same material or any material similar thereto that will thermally cure or photocure and bind to the material of the first article. By positioning the first article and second article adjacent one another and subjecting the first and second articles to a thermal curing or photocuring, whichever component that was not activated on the first curing. Thereafter, either the thermal cure constituents of the first article that were left un-activated by the photocuring process or the photocure constituents of the first article that were left un-activated by the first thermal curing, will be activated and bind the second article. Thereby, the first and second articles become adhered together. It will be appreciated by one of ordinary skill in the art that the order of curing processes is independent and a thermal-curing could occur first followed by a photocuring or a photocuring could occur first followed by a thermal curing.
According to yet another embodiment, dual cure materials can include multiple thermo-curable constituents included in the material such that the material can be subjected to multiple independent thermal-cures. For example, the multiple thermal-curable constituents can have different activation temperature ranges such that the material can undergo a first thermal-cure at a first temperature range and a second thermal-cure at a second temperature range. Accordingly, the material can be adhered to multiple other materials through different thermal-cures, thereby, forming a multiple laminate layer article.
According to another embodiment, dual cure materials can include materials having multiple photo curable constituents that can be triggered at different wavelengths. For example, a first photo curable constituent can be triggered at a first applied wavelength and such wavelength can leave a second photo curable constituent available for activation at a second wavelength.
Examples of chemical groups which would be suitable end-capping agents for a UV curable component include: methacrylates, acrylates, styrenics, epoxides, cyclobutanes and other 2+2 cycloadditions, combinations thereof, and the like. Examples of chemical group pairs which are suitable to endcap a thermally curable component include: epoxy/amine, epoxy/hydroxyl, carboxylic acid/amine, carboxylic acid/hydroxyl, ester/amine, ester/hydroxyl, amine/anhydride, acid halide/hydroxyl, acid halide/amine, amine/halide, hydroxyl/halide, hydroxyl/chlorosilane, azide/acetylene and other so-called “click chemistry” reactions, and metathesis reactions involving the use of Grubb's-type catalysts, combinations thereof, and the like.
The presently disclosed methods for the adhesion of multiple layers of a article to one another or to a separate surface can be applied to PFPE-based materials, as well as a variety of other materials, including PDMS and other liquid-like polymers. Examples of liquid-like polymeric materials that are suitable for use in the presently disclosed adhesion methods include, but are not limited to, PDMS, poly(tetramethylene oxide), poly(ethylene oxide), poly(oxetanes), polyisoprene, polybutadiene, and fluoroolefin-based fluoroelastomers, such as those available under the registered trademarks VITON® AND KALREZ®.
Accordingly, the presently disclosed methods can be used to adhere layers of different polymeric materials together to form articles, such as laminate moldes, and the like.
II.E. Silicone Based Materials
According to alternate embodiments, novel silicone based materials include photocurable and thermal-curable components. In such alternate embodiments, silicone based materials can include one or more photo-curable and thermal-curable components such that the silicone based material has a dual curing capability as described herein. Silicone based materials compatible with the present invention are described herein and throughout the reference materials incorporated by reference into this application.
II.F. Phosphazene-Containing Polymers
According to some embodiments, articles and methods disclosed herein can be formed with materials that include phosphazene-containing polymers having the following structure. According to these embodiments, R, in the structure below, can be a fluorine-containing alkyl chain. Examples of such fluorine-containing alkyl chains can be found in Langmuir, 2005, 21, 11604, the disclosure of which is incorporated herein by reference in its entirety. The articles disclosed in this application can be formed from phosphazene-containing polymers or from PFPE in combination with phosphazene-containing polymers.
II.G. Materials End-Capped with an Aryl Trifluorovinyl Ether (TVE)
In some embodiments, articles and methods disclosed herein can be formed with materials that include materials end-capped with one or more aryl trifluorovinyl ether (TVE) group, as shown in the structure below. Examples of materials end-capped with a TVE group can be found in Macromolecules, 2003, 36, 9000, which is incorporated herein by reference in its entirety. These structures react in a 2+2 addition at about 150° C. to form perfluorocyclobutyl moieties. In some embodiments, Rf can be a PFPE chain. In some embodiments three or more TVE groups are present on a 3-armed PFPE polymer such that the material crosslinks into a network.
II.H. Sodium Naphthalene Etchant
In some embodiments a sodium naphthalene etchant, such as commercially available TETRAETCH™, is contacted with a layer of a fluoropolymer article, such as an article disclosed herein. In other embodiments, a sodium naphthalene etchant is contacted with a layer of a PFPE-based article, such as laminate articles disclosed herein. According to such embodiments, the etch reacts with C—F bonds in the polymer of the article forming functional groups along a surface of the article. In some embodiments, these functional groups can then be reacted with modalities on other layers, on a silicon surface, on a glass surface, on polymer surfaces, combinations thereof, or the like, thereby forming an adhesive bond. In some embodiments, such adhesive bonds available on the surface of articles disclosed herein, such as laminate mold articles, can increase adhesion between two articles, layers of an article, combinations thereof, or the like. Increasing the bonding strength between layers of a laminate mold can increase the functionality of the article, for example, by increasing the binding strength between laminate layers.
II.I. Trifunctional PFPE Precursor
According to some embodiments, a trifunctional PFPE precursor can be used to fabricate articles disclosed herein, such as laminate mold articles. The trifunctional PFPE precursor disclosed herein can increase the functionality of an overall article by increasing the number of functional groups that can be added to the material. Moreover, the trifunctional PFPE precursor can provide for increased cross-linking capabilities of the material. According to such embodiments, articles can be synthesized by the following reaction scheme.
In further embodiments, a trifunctional PFPE precursor for the fabrication of articles, such as for example laminate articles disclosed herein, is synthesized by the following reaction scheme.
II.J. Fluoroalkyliodide Precursors for Generating Fluoropolymers and/or PFPE's
In some embodiments, functional PFPEs or other fluoropolymers can be generated using fluoroalkyliodide precursors. According to such embodiments, such materials can be modified by insertion of ethylene and then transformed into a host of common functionalities including but not limited to: silanes, Gringard reagents, alcohols, cyano, thiol, epoxides, amines, and carboxylic acids.
Rf—I+=→Rf—CH 2 —CH 2 —I
II.K. Diepoxy Materials
According to some embodiments, one or more of the PFPE precursors useful for fabricating articles disclose herein, such as laminate articles for example, contains diepoxy materials. The diepoxy materials can be synthesized by reaction of PFPE diols with epichlorohydrin according to the reaction scheme below.
II.L. Encapped PFPE Chains with Cycloaliphatic Epoxides
In some embodiments, PFPE chains can be encapped with cycloaliphatic epoxides moeites such as cyclohexane epoxides, cyclopentane epoxides, combinations thereof, or the like. In some embodiments, the PFPE diepoxy is a chain-extending material having the structure below synthesized by varying the ratio of diol to epichlorohydrin during the synthesis. Examples of some synthesis procedures are described by Tonelli et al. in Journal of Polymer Science: Part A: Polymer Chemistry 1996, Vol 34, 3263, which is incorporated herein by reference in its entirety. Utilizing this method, the mechanical properties of the cured material can be tuned to predetermined standards.
In further embodiments, the secondary alcohol formed in this reaction can be used to attach further functional groups. An example of this is shown below whereby the secondary alcohol is reacted with 2-isocyanatoethyl methacrylate to yield a material with species reactive towards both free radical and cationic curing. Functional groups such as in this example can be utilized to bond surfaces together, such as for example, layers of PFPE material in laminate molds.
II.M. PFPE Diepoxy Cured with Diamines
In some embodiments, PFPE diepoxy can be cured with traditional diamines, including but not limited to, 1,6 hexanediamine; isophorone diamine; 1,2 ethanediamine; combinations thereof; and the like. According to some embodiments the diepoxy can be cured with imidazole compounds including those with the following or related structures where R1, R2, and R3 can be a hydrogen atom or other alkyl substituents such as methyl, ethyl, propyl, butyl, fluoroalkyl compounds, combinations thereof, and the like. According to some embodiments, the imidazole agent is added to the PFPE diepoxy in concentrations on the order of between about 1-25 mol % in relation to the epoxy content. In some embodiments the PFPE diepoxy containing an imidazole catalyst is the thermal part of a two cure system, such as described elsewhere herein.
II.N. PFPE Cured with Photoacid Generators
In some embodiments, a PFPE diepoxy can be cured through the use of photoacid generators (PAGs). The PAGs are dissolved in the PFPE material in concentrations ranging from between about 1 to about 5 mol % relative to epoxy groups and cured by exposure to UV light. Specifically, for example, these photoacid generators can posses the following structure (Rhodorsil™) 2074 (Rhodia, Inc):
In other embodiments, the photoacid generator can be, for example, Cyracure™ (Dow Corning) possessing the following structure:
II.O. PFPE Diol Containing a Poly(Ethylene Glycol
In some embodiments, commercially available PFPE diols containing a number of poly(ethylene glycol) units can be used as the material for fabrication of a article, such as laminate articles. In other embodiments, the commercially available PFPE diol containing a given number f poly(ethylene glycol) units is used in combination with other materials disclosed herein. Such materials can be useful for dissolving the above described photoinitiators into the PFPE diepoxy and can also be helpful in tuning mechanical properties of the material as the PFPE diol containing a poly(ethylene glycol) unit can react with propagating epoxy units and can be incorporated into the final network.
II.P. PFPE Diols and/or Polyols Mixed with a PFPE Diepoxy
In further embodiments, commercially available PFPE diols and/or polyols can be mixed with a PFPE diepoxy compound to tune mechanical properties by incorporating into the propagating epoxy network during curing.
II.Q. PFPE Epoxy-Containing a PAG Blended with a Photoinitiator
In some embodiments, a PFPE epoxy-containing a PAG can be blended with between about 1 and about 5 mole % of a free radical photoinitiator such as, for example, 2,2-dimethoxyacetophenone, 1-hydroxy cyclohexyl phenyl ketone, diethoxyacetophenone, combinations thereof, or the like. These materials, when blended with a PAG, form reactive cationic species which are the product of oxidation by the PAG when the free-radical initiators are activated with UV light, as partially described by Crivello et al. Macromolecules 2005, 38, 3584, which is incorporated herein by reference in its entirety. Such cationic species can be capable of initiating epoxy polymerization and/or curing. The use of this method allows the PFPE diepoxy to be cured at a variety of different wavelengths.
II.R. PFPE Diepoxy Containing a Photoacid Generator and Blended with a PFPE Dimethacrylate
In some embodiments, a PFPE diepoxy material containing a photoacid generator can be blended with a PFPE dimethacrylate material containing a free radical photoinitiator and possessing the following structure:
The blended material includes a dual cure material which can be cured at one wavelength, for example, curing the dimethacrylate at 365 nm, and then bonded to other layers of material through activating the curing of the second diepoxy material at another wavelength, such as for example 254 nm. In this manner, multiple layers of patterned PFPE materials can be bonded and adhered to other substrates such as glass, silicon, other polymeric materials, combinations thereof, and the like at different stages of fabrication of an overall article.
II.S. Other Materials
According to alternative embodiments, the following materials can be utilized alone, in connection with other materials disclosed herein, or modified by other materials disclosed here and applied to the methods disclosed herein to fabricate the articles disclosed herein. Moreover, end-groups disclosed herein and disclosed in U.S. Pat. Nos. 3,810,874; and 4,818,801, each of which is incorporated herein by reference including all references cited therein.
II.S.i Diurethane Methacrylate
In some embodiments, the material is or includes diurethane methacrylate having a modulus of about 4.0 MPa and is UV curable with the following structure:
II.S.ii Chain-Extended Diurethane Methacrylate
In some embodiments, the material is or includes a chain extended diurethane methacrylate, wherein chain extension before end-capping increases molecular weight between crosslinks, a modulus of approximately 2.0 MPa, and is UV curable, having the following structure:
II.S.iii Diisocyanate
In some embodiments, the material is typically one component of a two-component thermally curable system; may be cured by itself through a moisture cure technique; and has the following structure:
II.S.iv Chain Extended Diisocyanate
In some embodiments, the material is or includes, one component of a two component thermally curable system; chain extended by linking several PFPE chains together; may be cured by itself through a moisture cure; and includes the following structure:
II.S.v Blocked Diisocyanate
In some embodiments, the material is or includes: one component of a two component thermally curable system; and includes the following structure:
II.S.vi PFPE Three-Armed Triol
In some embodiments, the material is or includes a PFPE triol as one component of a two-component thermally curable urethane system; includes the benefits of being highly miscible with other PFPE compositions; and includes the following structure:
II.S.vii PFPE DiStyrene
In some embodiments, the material is or includes PFPE distyrene material that is UV curable, highly chemically stable, is useful in making laminate coatings with other compositions, and includes the following structure:
II.S.viii Diepoxy
In some embodiments, the material can be UV cured; can be thermally cured by itself using imidazoles; can also be thermally cured in a two-component diamine system; is highly Chemically stable; and includes the following structure:
II.S.ix Diamine
In some embodiments, the material can be thermally cured in a two-component diamine system; has functionality of 6 (3 amines available on each end); is highly chemically stable; and includes the following structure:
II.S.x Thermally Cured PU—Tetrol
In some embodiments, the material can be thermally cured in a two-component system, such as for example mixed in a 2:1 molar ratio at about 100-about 130 degrees C; forms tough, mechanically stable network; the cured network is slightly cloudy due to immiscibility of tetrol; and includes the following structure:
II.S.xi Thermally Cured PU—Triol
In some embodiments, the material can be thermally cured in a two-component system, such as for example mixed in a 3:2 molar ratio, at about 100-about 130 degrees C; forms tough, mechanically stable network; where the cured network is clear and colorless; and includes the following structure:
II.S.xii Thermally Cured Epoxy
In some embodiments, the material can be thermally cured in a two-component system, such as for example mixed in a 3:1 molar ratio, at about 100-about 130 degrees C; forms mechanically stable network; where the cured network is clear and colorless; has high chemical stability; and includes the following structure:
II.S.xiii UV-Cured Epoxy
In some embodiments, the material is a UV curable composition; includes ZDOL TX used to solubilize PAG; where the cured network is clear and yellow; has high chemical stability; and includes the following structure:
II.S.ixv UV-Thermal Dual Cure
In some embodiments, the material can be mixed in a 2:1 ratio (UV to thermal); forms cloudy network (tetrol); has a high viscosity; forms a very strong adhesion; has very good mechanical properties; and includes the following structure:
II.S.xv Orthogonal Cure with Triol
In some embodiments, the material can be mixed in a 2:1 ratio (UV to thermal); forms clear and colorless network; has a high viscosity; forms very strong adhesion; includes very good mechanical properties; and includes the following structure:
II.S.xvi UV Orthogonol System
In some embodiments, the material includes ZDOL-TX, which can be mixed in a 1:1 ratio (epoxy to methacrylate); forms clear and yellow network; has strong adhesion properties; has good mechanical properties; and includes the following structure:
II.S.xvii UV with Epoxy Dual Cure
In some embodiments, the material forms slightly yellow network; includes a ratio (2:1 UV to thermal); has good mechanical properties; good adhesion; is highly chemical stability; and includes the following structure:
II.S.xviii Orthogonal with Diisocyanate
In some embodiments, the material is one component thermal component (Isocyanate reacts with urethane linkage on urethane dimethacrylate); has good mechanical properties; forms a strong adhesion; cures to clear, slightly yellow network; and includes the following structure:
III. PATTERNED LAMINATE MOLDS FABRICATED FROM THE DISCLOSED MATERIALS
The materials of the present invention can be utilized to form laminate layers of nano-sized predetermined shape molds and lamination adhesion promoter tie-layers for fabricating such molds. Referring now to FIG. 1 , a general laminate mold 100 of the present invention includes a backing layer 102 affixed to a patterned mold layer 104 by a tie-layer 106 . In certain embodiments, tie-layer 106 is used to bond mold layer 104 to backing layer 102 . According to some embodiments, patterned mold layer 104 includes a patterned surface 108 . Mold layer 104 can be made from the materials disclosed herein, and combinations thereof. Patterns on patterned surface 108 can include cavities 110 and land area L that extends between cavities 110 . Patterns on patterned surface 108 can also include a pitch, such as pitch P, which is generally the distance from a first edge of one cavity to a first edge of an adjacent cavity including land area L between the adjacent cavities.
According to some embodiments, laminate mold 100 is fabricated from a two stage lamination process. Initially, a composition, (e.g. a material described herein such as a dual-cure composition) includes the structures shown below in Scheme 1 of Example 1.
Scheme 1 of Example 1: PFPE Dual Cure Composition
Next, the compositions shown in Scheme 1 of Example 1 are combined with 2.0% by weight diethoxyacetophenone photoinitiator and 0.1% by weight dibutyltin diacetate catalyst. Separately, two polymer sheets, 202 and 204 , are cut into desired dimensions. The two sheets are then configured adjacent each other along their face. According to some embodiments, the sheets are selected from film forming polymers such as, but not limited to, poly(ethylene terephthalate) (PET), polycarbonate (PC), Melinex 453® (Dupont Teijin Films) treated PET, Melinex 454® (Dupont Teijin Films) treated PET, Melinex 582® (Dupont Teijin Films) treated PET, corona treated polymers, silicone based polymers, glass, urethane based polymers, combinations thereof, and the like.
The configured sheets are then inserted into a two roll nip configuration, such as two roll laminator 200 , shown in FIG. 2 . Two roll laminator 200 has two rollers 202 and 204 , and at least one of the rollers 202 or 204 is driven by a motor. Rollers 202 and 204 are movable with respect to each other such that a distance between a centerline of rollers 202 and 204 can be increased and/or decreased and oppose each other under a reproducable pressure. Next, the polymer sheets 206 and 208 are positioned between rollers 202 and 204 and the rollers are closed onto the sheets. In some embodiments, rollers 202 and 204 can be fabricated with a rubber covering, rubber having a shore hardness value of 85, polymer materials, metal, ceramic materials, aluminum, stainless steel, and the like. In some embodiments, the rollers are configured to pinch the sheets at a pressure of between about 3 psig to about 80 psig. In other embodiments, the rollers are configured to pinch the sheets at a pressure of between about 5 psig and about 65 psig. In still other embodiments, the rollers are configured to pinch the sheets at a pressure of at least about 3 psig.
After one end of the configured two polymer sheets 206 and 208 are pinched between rollers 202 and 204 , a bead of tie-layer material 210 (e.g. dual-cure materials disclosed herein), is introduced between polymer sheets 206 and 208 near nip point 212 of the rollers 202 and 204 . Next, the two roll laminator is activated, thereby rolling polymer sheets 206 and 208 between rollers 202 and 204 and distributing tie-layer material 210 into a thin layer between polymer sheets 206 and 208 . In some embodiments, the tie-layer 210 is distributed into a layer of between about 5 micrometers and about 75 micrometers. In other embodiments, the tie-layer 210 is distributed into a layer of between about 10 micrometers and about 50 micrometers. In some embodiments, the tie-layer 210 is distributed into a layer of between about 15 micrometers and about 40 micrometers. In some embodiments, the tie-layer 210 is distributed into a layer of between about 20 micrometers and about 30 micrometers. In some embodiments, the tie-layer 210 is distributed into a layer of between about 10 micrometers and about 35 micrometers. In some embodiments, the tie-layer 210 is distributed into a layer of between about 10 micrometers and about 25 micrometers. According to some embodiments, the two roll laminator is actuated at a speed of about 5 ft/minute. According to another embodiment, the two roll laminator is actuated at a speed of less than about 5 ft/minute. According to other embodiments, the two roll laminator is actuated at a speed of between about 1 ft/minute and about 10 ft/minute. According to still another embodiment, the two roll laminator is actuated at a speed of about 1 ft/minute.
After roll laminating polymer sheets 206 and 208 with tie-layer 210 distributed therebetween, laminate 214 is cured (e.g., UV cured) to cure or partially cure tie-layer 210 . In some embodiments, laminate 214 is cured (e.g., UV cured) in a conveyer system (e.g., UV conveyer system) in which the conveyor is moved at about 8 ft/minute and the UV power output is about 200 Watts/inch. According to such embodiments, laminate 214 is positioned approximately 3 inches from the UV source for UV curing. In some embodiments, following curing, the cured laminate 214 is secondarily cured (e.g., placed in a thermal oven) for curing of tie-layer 210 . In some embodiments, thermal oven is set at, and preheated to, 100° C. and laminate 214 is subjected to the thermal condition of the thermal oven for about 10 minutes. After laminate 214 has been secondarily cured (e.g., thermal cured) polymer sheets 206 and 208 are separated. In some embodiments, polymer sheets 206 and 208 are separated by hand by peeling sheets 206 and 208 apart at a rate of about 1 inch per second. In preferred embodiments, tie-layer 210 remains substantially entirely on one of the polymer sheets, 206 or 208 .
In some embodiments, separately, a UV curable PFPE resin, having a formula shown as Scheme 2 of Example 1, is mixed with 2.0% by weight diethoxyacetophenone. In some embodiments, the UV curable PFPE resin and the 2.0% by weight diethoxyacetophenone is mixed by hand for more than about 2 minutes at room temperature in a glass vial.
Scheme 2 of Example 1—UV Curable PFPE Composition
Next, polymer sheet 206 with tie-layer 210 affixed thereto is positioned with respect to a patterned master 216 , as shown in FIG. 3 . In some embodiments, patterned master is a silicon wafer master patterned with an array of nano-sized structures having predetermined shapes. In other embodiments, patterned master 216 includes viruses, nanotubes, or dendrimers on surfaces. In other embodiments, patterned master 216 can include anodized alumina templates. In some embodiments, the nano-sized structures are 200 nm×200 nm×400 nm cylindrical posts. In other embodiments, the nano-sized structures are 2 micron×2 micron×0.7 micron cuboidal structures protruding from the silicon master.
In other embodiments, the nano-sized structures are 1 micron×1 micron×0.7 micron cuboidal structures protruding from the silicon master. In other embodiments, the nano-sized structures are 1 micron diameter×0.7 micron height cylindrical post structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.9 micron×0.9 micron×0.9 micron cuboidal structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.9 micron×0.9 micron×0.7 micron cuboidal structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.9 micron diameter×0.9 micron height cylindrical structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.8 micron×0.8 micron×0.8 micron cuboidal structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.8 micron×0.8 micron×0.6 micron cuboidal structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.8 micron diameter×0.8 micron height cylindrical structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.7 micron×0.7 micron×0.7 micron cuboidal structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.7 micron×0.7 micron×0.5 micron cuboidal structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.7 micron diameter×0.7 micron height cylindrical structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.6 micron×0.6 micron×0.6 micron cuboidal structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.6 micron×0.6 micron×0.3 micron cuboidal structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.6 micron diameter×0.6 micron height cylindrical structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.5 micron×0.5 micron×0.5 micron cuboidal structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.5 micron×0.5 micron×0.2 micron cuboidal structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.5 micron diameter×0.8 micron height cylindrical structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.4 micron×0.4 micron×0.4 micron cuboidal structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.4 micron×0.4 micron×0.7 micron cuboidal structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.4 micron diameter×0.4 micron height cylindrical structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.3 micron×0.3 micron×0.3 micron cuboidal structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.3 micron×0.3 micron×0.1 micron cuboidal structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.3 micron diameter×0.2 micron height cylindrical structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.2 micron×0.2 micron×0.2 micron cuboidal structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.2 micron×0.2 micron×0.05 micron cuboidal structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.2 micron diameter×0.2 micron height cylindrical structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.1 micron×0.1 micron×0.1 micron cuboidal structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.1 micron×0.1 micron×0.05 micron cuboidal structures protruding from the silicon master. In other embodiments, the nano-sized structures are 0.1 micron diameter×0.1 micron height cylindrical structures protruding from the silicon master.
According to still other embodiments, the nano-sized structures can be less than about 10 nm is a broadest dimension. In other embodiments, the nano-sized structures can be between about 5 nm and about 25 nm. In other embodiments, the nano-sized structures can be between about 5 nm and about 50 nm. In other embodiments, the nano-sized structures can be between about 5 nm and about 75 nm. In other embodiments, the nano-sized structures can be between about 5 nm and about 100 nm. In other embodiments, the nano-sized structures can be between about 5 nm and about 150 nm. In other embodiments, the nano-sized structures can be between about 5 nm and about 200 nm. In other embodiments, the nano-sized structures can be between about 5 nm and about 250 nm. In other embodiments, the nano-sized structures can be between about 5 nm and about 350 nm. In other embodiments, the nano-sized structures can be between about 5 nm and about 500 nm. In other embodiments, the nano-sized structures can be between about 5 nm and about 750 nm. In other embodiments, the nano-sized structures can be between about 5 nm and about 1 micrometer. In other embodiments, the nano-sized structures can be between about 5 nm and about 2 micrometers. In other embodiments, the nano-sized structures can be between about 5 nm and about 5 micrometers.
Next, polymer sheet 206 , having tie-layer 210 positioned adjacent a patterned side of patterned master 216 and the combination is introduced into nips of a two roll laminator, such as two roll laminator 200 described above. After polymer sheet 206 and patterned master 216 are affixed in rollers 202 and 204 , UV curable material 218 , such as that disclosed herein, is introduced between an interface of patterned master 216 and tie-layer 210 of polymer sheet 206 . Two roll laminator 200 is then activated to thereby laminate polymer sheet 206 , tie-layer 210 , UV curable material 218 , and patterned master 216 together. After the combination of layers has passed through two roll laminator 200 , the combination laminate is cured (e.g. UV cured) to cure curable material 218 into a solidified layer attached to tie-layer 210 . According to some embodiments, after patterned master 216 is separated from laminate layers 206 , 210 , and 218 , the resulting laminate includes a thin layer of curable material 218 adhered to tie-layer 210 which is adhered to polymer sheet 206 . Furthermore, curable layer 218 includes an inverse replica of features of patterned master 216 , such as cavities 110 . In some embodiments, curable layer 218 is between about 5 microns and about 50 microns thick. In some embodiments, curable layer 218 is between about 5 microns and about 30 microns thick. In some embodiments, curable layer 218 is between about 10 microns and about 25 microns thick. In some embodiments, curable layer 218 is less than about 75 microns thick. In some embodiments, curable layer 218 is less than about 70 microns thick. In some embodiments, curable layer 218 is less than about 65 microns thick. In some embodiments, curable layer 218 is less than about 60 microns thick. In some embodiments, curable layer 218 is less than about 55 microns thick. In some embodiments, curable layer 218 is less than about 50 microns thick. In some embodiments, curable layer 218 is less than about 45 microns thick. In some embodiments, curable layer 218 is less than about 40 microns thick. In some embodiments, curable layer 218 is less than about 35 microns thick. In some embodiments, curable layer 218 is less than about 30 microns thick. In some embodiments, curable layer 218 is less than about 25 microns thick. In some embodiments, curable layer 218 is less than about 20 microns thick. In some embodiments, curable layer 218 is less than about 15 microns thick. In some embodiments, curable layer 218 is less than about 10 microns thick. In some embodiments, curable layer 218 is less than about 7 microns thick.
In still other embodiments, laminate mold 100 is configured with a backing 102 and a single laminate layer 104 adhered directly to backing 102 . According to certain embodiments, laminate layer 104 is dual-cure materials disclosed herein, UV-curable materials, thermal curable materials, disclosed herein. Such laminate molds are fabricated, according to FIG. 3 , however, without using tie-layer 210 on backing layer 206 . Accordingly, backing layer 206 and patterned master 216 are configured in alignment with each other and with rollers 202 and 204 , as described herein. Next, either dual-cure materials described herein, UV-curable materials disclosed herein, or thermal curable materials are deposited between backing layer 206 and patterned master 216 on an input side of rollers 202 and 204 . Then, when the rollers are activated the dual-cure or UV-curable material is dispersed between backing 206 and patterned master 216 and conform to a pattern of patterned master 216 . Next, the laminate of backing 206 , un-cured dual-cure or UV-curable material, and patterned master 216 are subjected to a UV-curing treatment T, as shown in FIG. 4 . Following UV-curing, if a UV-curable material was used, the patterned master 216 and backing 206 are separated, as shown in the right side of FIG. 4 . However, if a dual-cure material was utilized, the UV-cured laminate is subjected to a thermal curing to active the thermal component of the dual-cure. Following thermal curing, the backing 206 and patterned master 216 is separated such that the dual-cure layer mimics the pattern of patterned master 216 and is adhered to backing 206 , as shown in FIG. 4 .
Referring now to FIG. 5 , a laminate mold 500 mimicking patterned structures of a patterned master 216 are shown. According to FIG. 5 , the structures mimicked are 200 nm diameter cylindrical cavities or cavities, the land area L is roughly 200 nm, and the pitch P is roughly 400 nm. FIG. 6 shows a molded material 600 molded from the laminate mold 500 of FIG. 5 , wherein structures 602 are 200 nm diameter cylindrical posts, land area L is roughly 200 nm, and pitch P is roughly 400 nm.
In some embodiments, cavities 110 can include any structure that is etched onto silicone wafer. In some embodiments, cavities 110 can include an array of structures which are a repetitious pattern, a random pattern, and combinations thereof of the same structure or a variety of structure sizes and shapes. According to some embodiments, cavities 110 have a cross-sectional diameter of less than about 5 micrometers. According to some embodiments, cavities 110 have a cross-sectional diameter of less than about 2 micrometers. According to some embodiments, cavities 110 have a cross-sectional diameter of less than about 1 micrometer. According to some embodiments, cavities 110 have a cross-sectional diameter of less than about 500 nm. According to some embodiments, cavities 110 have a cross-sectional diameter of less than about 250 nm. According to some embodiments, cavities 110 have a cross-sectional diameter of less than about 200 nm. According to some embodiments, cavities 110 have a cross-sectional diameter of less than about 150 nm. According to some embodiments, cavities 110 have a cross-sectional diameter of less than about 100 nm. According to some embodiments, cavities 110 have a cross-sectional diameter of less than about 75 nm. According to some embodiments, cavities 110 have a cross-sectional diameter of less than about 50 nm. According to some embodiments, cavities 110 have a cross-sectional diameter of less than about 40 nm. According to some embodiments, cavities 110 have a cross-sectional diameter of less than about 30 nm. According to some embodiments, cavities 110 have a cross-sectional diameter of less than about 20 nm. According to some embodiments, cavities 110 have a cross-sectional diameter of less than about 15 nm. According to some embodiments, cavities 110 have a cross-sectional diameter of less than about 10 nm.
According to some embodiments, cavities 110 have a depth of less than about 500 nm. According to other embodiments, cavities 110 have a depth of less than about 300 nm. According to some embodiments, cavities 110 have a depth of less than about 250 nm. According to some embodiments, cavities 110 have a depth of less than about 150 nm. According to some embodiments, cavities 110 have a depth of less than about 100 nm. According to some embodiments, cavities 110 have a depth of less than about 75 nm. According to some embodiments, cavities 110 have a depth of less than about 50 nm. According to some embodiments, cavities 110 have a depth of less than about 30 nm. According to some embodiments, cavities 110 have a depth of less than about 20 nm. According to some embodiments, cavities 110 have a depth of less than about 15 nm. According to some embodiments, cavities 110 have a depth of less than about 10 nm.
According to other embodiments, cavities 110 have a width to depth ratio of between about 1,000:1 and about 100,000:1. According to other embodiments, cavities 110 have a width to depth ratio of between about 1,000:1 and about 10,000:1. According to other embodiments, cavities 110 have a width to depth ratio between of about 100:1 and about 1,000:1. According to other embodiments, cavities 110 have a width to depth ratio of about 1,000:1. According to other embodiments, cavities 110 have a width to depth ratio of about 800:1. According to other embodiments, cavities 110 have a width to depth ratio of about 600:1. According to other embodiments, cavities 110 have a width to depth ratio of about 500:1. According to other embodiments, cavities 110 have a width to depth ratio of about 400:1. According to other embodiments, cavities 110 have a width to depth ratio of about 300:1. According to other embodiments, cavities 110 have a width to depth ratio of about 200:1. According to other embodiments, cavities 110 have a width to depth ratio of about 100:1. According to other embodiments, cavities 110 have a width to depth ratio of about 80:1. According to other embodiments, cavities 110 have a width to depth ratio of about 70:1. According to other embodiments, cavities 110 have a width to depth ratio of about 50:1. According to other embodiments, cavities 110 have a width to depth ratio of about 40:1. According to other embodiments, cavities 110 have a width to depth ratio of about 30:1. According to other embodiments, cavities 110 have a width to depth ratio of about 20:1. According to other embodiments, cavities 110 have a width to depth ratio of about 10:1. According to other embodiments, cavities 110 have a width to depth ratio of about 5:1. According to other embodiments, cavities 110 have a width to depth ratio of about 2:1.
According to some embodiments, a shape of cavities 110 are selected from the group of cylindrical, cuboidal, star, arrow, semi-spherical, conical, cresent, viral, cellular, concave disk, and any other shape that can be etched into a patterned master such as a silicon wafer.
In some embodiments, polymer sheet 206 is a PET sheet having a thickness of less than about 10 mil. In some embodiments, a PET sheet having a tie-layer 210 and a UV curable PFPE layer 218 can have a modulus of about 1400 MPa.
According to some embodiments, the land area of the laminate mold is between about 5% and about 99% of the entire surface area. According to some embodiments, the land area of the laminate mold is between about 5% and about 90% of the entire surface area. According to some embodiments, the land area of the laminate mold is between about 5% and about 80% of the entire surface area. According to some embodiments, the land area of the laminate mold is between about 5% and about 75% of the entire surface area. According to some embodiments, the land area of the laminate mold is between about 5% and about 60% of the entire surface area. According to some embodiments, the land area of the laminate mold is between about 5% and about 50% of the entire surface area. According to some embodiments, the land area of the laminate mold is between about 5% and about 40% of the entire surface area. According to some embodiments, the land area of the laminate mold is between about 5% and about 30% of the entire surface area. According to some embodiments, the land area of the laminate mold is between about 5% and about 25% of the entire surface area. According to some embodiments, the land area of the laminate mold is between about 5% and about 20% of the entire surface area. According to some embodiments, the land area of the laminate mold is between about 5% and about 15% of the entire surface area. According to some embodiments, the land area of the laminate mold is between about 5% and about 10% of the entire surface area.
According to some embodiments, the dual-cure material and the UV-curable material of the laminate molds of the present invention can include the materials described herein. In some embodiments, the PFPE formulations described herein are used themselves as the molded layer of the laminate. In further embodiments molded PFPE layers are adhered to backing substrates using tie-layers formulated with PFPEs containing various functional end groups. In further embodiments the tie-layer includes a dual-cure mixture of PFPE materials such that one component is capable of being cured by actinic radiation and another is capable of being cured thermally. In other embodiments, the molded PFPE layer itself may include a dual-cure PFPE formulation.
In some embodiments an additional tie-layer structure is not needed between the substrate and the PFPE mold. In further embodiments the PFPE formulation used to fabricate the mold is formulated such that it will adhere to a particular backing material upon curing. In further embodiments, the backing material is chemically functionialized to adhere to a particular PFPE mold formulation.
It should be appreciated, however, that the present invention can be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this presently described subject matter belongs. All publications, patent applications, patents, and other references mentioned herein are incorporated herein by reference in their entirety. Throughout the specification and claims, a given chemical formula or name shall encompass all optical and stereoisomers, as well as racemic mixtures where such isomers and mixtures exist.
IV. EXAMPLES
The following Examples have been included to provide guidance to one of ordinary skill in the art for practicing representative embodiments of the presently disclosed subject matter. In light of the present disclosure and the general level of skill in the art, those of skill can appreciate that the following Examples are intended to be exemplary only and that numerous changes, modifications, and alterations can be employed without departing from the scope of the presently disclosed subject matter.
Example 1
Step 1: To form an adhesion promoter for PFPE molds to PET, a dual-cure composition of the PFPE structures, shown below in Scheme 1 of Example 1, was mixed by hand stir for at least 2 minutes at room temperature in a glass vial. In particular, the dual-cure composition of PFPE structures includes the structures shown in Scheme 1 with 2.0% by weight diethoxyacetophenone photoinitiator and 0.1% by weight dibutyltin diacetate catalyst.
Step 2: Two 6″×12″×7 mil sheets of Melinex 453 (Dupont Teijin Films) treated poly(ethylene terephthalate) (PET) (one side treated) were provided. The two sheets were then configured with a treated side of one sheet facing an untreated side of the other sheet. The configured sheets were inserted into a two roll laminator having two 1″ diameter rubber coated rollers having a length of 8″ with both rubber rollers having a shore hardness value of 85. The rollers were closed, thereby pinching the configured sheets at a pressure of 60 psig pneumatically driven together by two cylinders of 1″ in diameter with approximately 2″ of the PET sheets extending beyond the exit side of the rollers. Approximately 2 mL of the dual-cure mixture was placed between the two PET sheets near the nip point on the input side of the rollers. The dual-cure was deposited in an even bead manner from a syringe having an opening of about 1 mm. The two roll laminator was then actuated at a speed of 1 ft/minute, driving the configuration through the nips and dispersing the dual-cure mixture between the two PET sheets and sealing the two PET sheets together with a thin film of dual-cure resin in between as shown in FIG. 2 . The two roll laminator was stopped prior to the two PET sheets passing completely through the nip point, such that about 1 inch of PET remained above the input side of the rollers.
Step 3: The PET/dual-cure resin/PET laminate was then UV cured in a UV conveyer system (UVPS conveyor system with Mercury arc lamp source model UVPS6T). The UV conveyor moved at 8 ft/minute with a power output of 200 Watts/inch placed approximately 3 inches above the sample. Prior to subjecting the PET/dual-cure resin/PET laminate to the UV cure, the UV conveyer was allowed to warm-up for about 10 minutes to reach full operating potential.
Step 4: Next, the UV-cured PET/dual-cure resin/PET laminate was placed in a thermal oven set at, and preheated to, 100° C. for 10 minutes. Following this, the PET/dual-cure/PET laminate was allowed to cool at room temperature for 1 minute before the PET sheets were separated by hand by peeling the two PET sheets apart at a rate of about 1 inch per second. The sheets separated cleanly with the dual-cure resin remaining on the PET non-Melinex 453 side of the laminate and the Melinex 453 treated side peeling off free of dual-cure resin.
Step 5: Separately, the UV curable PFPE resin, having the formula below in Scheme 2 of Example 1, was mixed by hand for about 2 minutes at room temperature in a glass vial with 2.0% by weight diethoxyacetophenone.
Step 6: Next, an 8″ silicon wafer master patterned with an array of 200 nm×200 nm×400 nm cylindrical posts was configured with the PET/dual-cure laminate sheet, formed in Steps 1-4, such that the dual-cure side was facing the patterned side of the wafer. The laminate and the wafer were then inserted into a two roll laminator having two 1″ diameter rubber coated rollers 8″ in length with both rubber rollers having a shore hardness value of 85. The rollers were closed, thereby pinching the configured sheets at a pressure of 60 psig, pneumaticaly driven by two steel cylinders of 1″ diameter with 1″ of the layers protruding beyond the exit side of the rollers. Approximately 1 mL of the UV-curable PFPE compound, described in Step 5, was evenly placed between the PET/dual-cure sheet and the wafer near the nip point on the inlet side of the rollers. The UV-curable PFPE was disposed in a bead pattern from a syringe having an opening of about 1 mm. The laminator was then actuated at a speed of 6 ft/min, laminating the PET/dual cure sheet to the 8″ patterned wafer with a thin film of UV-curable PFPE distributed in between as shown in FIG. 3 . The two roll laminator was then stopped when about 1 inch of the PET/dual-cure laminate/UV-curable PFPE/silicon master remained on the inlet side of the rollers. The rollers were carefully opened to release the PET/dual-cure laminate/UV-curable PFPE/silicon master laminate.
Step 7: The Dual cure sheet/UV-curable PFPE/Silicon wafer laminate was exposed to UV light through the PET sheet using a floodlamp (Oriel Arc Lamp, Mercury-Xenon, model 81172) placed approximately 3 inches from the sample for 1 minute to cure the UV-curable PFPE resin. Prior to exposing the dual-cure sheet/UV-curable PFPE/silicon wafer laminate to the UV floodlamp, the UV light source was allowed to warm up for 10 minutes. After exposure for 10 minutes, the light was extinguished and the dual-cure sheet/UV-curable PFPE/silicon wafer laminate was removed. Following removal from the floodlamp, the dual-cure sheet/UV-curable PFPE layer was carefully separated, by hand peeling at about 1 inch per second from the silicon master. Upon separation, a thin (10-20 micron) PFPE layer was adhered to the dual-cure adhered to the PET and the thin PFPE layer included features of the etched silicon wafers. An example of these procedures is shown in FIG. 4 .
Step 8: The PFPE mold was inspected after fabrication by scanning electron microscopy (SEM). FIG. 5 shows a representative image. FIG. 5 is an SEM image of a PFPE/PET laminate mold with 200 nm cavities in a hexagonal array.
Step 9: Mechanical Properties of the laminate mold formed in steps 1-7 were compared to a 1 mm thick mold made purely from the UV curable PFPE composition shown in Scheme 2. The thick mold was formed by casting directly onto the silicon master and UV curing under nitrogen for 2 minutes using an (ELC-4001 UV flood lamp available from Electrolite Corp, Bethel, Conn.).
Mold Material
Modulus (MPa)
UV-curable PFPE
7
(scheme 2)
PFPE/PET Laminate
1440
Step 10: The laminate mold formed in Step 7 was configured with a 6″×12″×7 mil sheet of Melinex 453 such that the patterned side of the mold was facing the treated side of the PET. The sheets were inserted into a two roll laminator having two 1″ diameter rubber coated rollers 6″ in length; one with a shore hardness of 30, and the other with a shore hardness of 70. The pattern on the laminate mold was facing the 30 durometer roller. The rollers were closed, thereby pinching the configured sheets at a pressure of 40 psig pneumaticaly driven by two steel cylinders of 1″ diameter with 1 inch of the layers protruding beyond the exit side of the rollers. Approximately 1 mL of a UV-curable optical adhesive, Dymax 1180-M (DYMAX Corp. Torrington, Conn.), was placed between the two PET sheets at the nip point on the top of the rollers. The laminator was then actuated at a speed of 4.6 ft/min, sealing the two PET sheets together with a thin film of Dymax 1180-M resin in between.
Step 11: The laminate was UV cured on the conveyer system described with respect to Step 3, moving at 8 ft/minute with a power output of 200 Watts/inch placed approximately 3 inches above the sample. The laminate was UV cured with the PET backed PFPE mold side toward the UV lamp.
Step 12: The layers were then carefully separated by hand peeling at about 1 inch per second to reveal a replicate pattern of the original patterned silicon master formed in the Dymax 1180-M. The fidelity of the pattern was inspected using SEM. FIG. 6 shows a representative image of the replica pattern formed from the laminate mold. FIG. 6 is an SEM image of a polymer replica on PET of hexagonally packed 200 nm posts formed from a PFPE/PET laminate mold.
Example 2
Step 1: To form an adhesion promoter for PFPE molds to PET, a dual-cure composition of the PFPE structures, shown in Scheme 1 of Example 1, was mixed by hand stir for at least 2 minutes at room temperature in a glass vial. In particular, the dual-cure composition of PFPE structures includes the structures shown in Scheme 1 of Example 1 with 2.0% by weight diethoxyacetophenone photoinitiator and 0.1% by weight dibutyltin diacetate catalyst.
Step 2: Two 6″×12″×7 mil sheets of Melinex 453 (Dupont Teijin Films) poly(ethylene terephthalate) (PET) were cut. The two sheets were then configured with a treated side of one sheet facing an untreated side of the other sheet. The configured sheets were inserted into a two roll laminator having two different size rollers. One roller is a 16 mm diameter rubber covered roller 9″ l length with a shore hardness of 30 and the other roller is a 30 mm diameter aluminum roller 9″ in length. The rollers were closed, thereby pinching the configured sheets at a pressure of 5 psig pneumaticaly driven together by 2 steel cylinders of 1.5″ diameter with 1″ of the layers protruding beyond the exit side of the rollers. Approximately 2 mL of the dual-cure mixture was placed between the two PET sheets near the nip point on the input side of the rollers. The dual-cure was deposited in an even bead manner from a syringe having an opening of about 1 mm. The two roll laminator was then actuated at a speed of 3 ft/minute, driving the configuration through the nips and dispersing the dual-cure mixture between the two PET sheets and sealing the two PET sheets together with a thin film of dual-cure resin in between. The two roll laminator was stopped prior to the two PET sheets passing completely through the nip point, such that about 1 inch of PET remained above the input side of the rollers.
Step 3: The PET/dual-cure resin/PET laminate was then UV cured in a UV flood lamp (ELC-4001 from Electro-Lite Corp, Bethel, Conn.) (Mercury arc lamp with an output range of 290-420 nm (365 nm peak)) and illuminated for 1 minute at approximately 3 inches from the lamp. Prior to subjecting the PET/dual-cure resin/PET laminate to the UV cure, the UV flood lamp was allowed to warm-up for about 10 minutes to reach full operating potential.
Step 4: Next, the UV-cured PET/dual-cure resin/PET laminate was placed in a thermal oven set at, and preheated to, 100° C. for 10 minutes. Following this, the PET/dual-cure/PET laminate was allowed to cool at room temperature for 1 minute before the PET sheets were separated by hand by peeling the two PET sheets apart at a rate of about 1 inch per second. The sheets separated cleanly with the dual-cure resin remaining on the PET non-Melinex 453 side of the laminate and the Melinex 453 treated side peeling off free of dual-cure resin.
Step 5: Separately, the UV curable PFPE resin, having the formula in Scheme 2 of Example 1, was mixed by hand for more than about 2 minutes at room temperature in a glass vial with 2.0% by weight diethoxyacetophenone.
Step 6: Next, a 6″ silicon master containing a patterned array of 2 μm×2 μm×0.7 μm cuboidal posts was configured with the PET/dual-cure laminate sheet, formed in Steps 1-4, such that the dual-cure side was facing the patterned side of the wafer. The laminate and the wafer were inserted into a two roll laminator having two different size rollers. One roller is a 16 mm diameter rubber coated roller, 9″ in length with a shore hardness of 30 and the other roller is a 30 mm diameter aluminum roller 9″ in length. The rollers were closed, thereby pinching the configured sheets at a pressure of 5 psig pneumaticaly driven by two steel cylinders of 1.5″ diameter with 1″ of the layers protruding beyond the exit side of the rollers. Approximately 1 mL of the UV-curable PFPE compound, described in Step 5, was evenly placed between the PET/dual-cure sheet and the wafer near the nip point on the inlet side of the rollers. The UV-curable PFPE was disposed in a bead pattern from a syringe having an opening of about 1 mm. The laminator was then actuated at a speed of 3 ft/minute, laminating the PET/dual cure sheet to the 6″ patterned wafer with a thin film of UV-curable PFPE distributed in between. The two roll laminator was then stopped when about 1 inch of the PET/dual-cure laminate/UV-curable PFPE/silicon master remained on the inlet side of the rollers. The rollers were carefully opened to release the PET/dual-cure laminate/UV-curable PFPE/silicon master laminate.
Step 7: The Dual cure sheet/UV-curable PFPE/Silicon wafer laminate was exposed to UV light through the PET sheet using a UV flood lamp (ELC-4001 from Electro-Lite Corp, Bethel, Conn.) (Mercury arc lamp with an output range of 290-420 nm (365 nm peak)) and were illuminated for 1 minute approximately 3 inches from the lamp. Prior to exposing the dual-cure sheet/UV-curable PFPE/silicon wafer laminate to the UV floodlamp, the UV light source was allowed to warm up for 10 minutes. After exposure for 10 minutes, the light was extinguished and the dual-cure sheet/UV-curable PFPE/silicon wafer laminate was removed. Following removal from the floodlamp, the dual-cure sheet/UV-curable PFPE layer was carefully separated, by hand peeling at about 1 inch per second from the silicon master. Upon separation, a thin (10-20 micron) PFPE layer was adhered to the dual-cure adhered to the PET and the thin PFPE layer included features of the etched silicon wafers.
Example 3
Step 1: To form an adhesion promoter for PFPE molds to PET, a dual-cure composition of the PFPE structures, shown in Scheme 1 or Example 1, was mixed by hand stir for at least 2 minutes at room temperature in a glass vial. In particular, the dual-cure composition of PFPE structures includes the structures shown in Scheme 1 of Example 1 with 2.0% by weight diethoxyacetophenone photoinitiator and 0.1% by weight dibutyltin diacetate catalyst.
Step 2: One 6″×12″×7 mil sheet of Melinex 453 (Dupont Teijin Films) poly(ethylene terephthalate) (PET) and one 6″×12″×4 mil sheet of Melinex 454 (amine functionalized) (Dupont Teijin Films) PET were prepared. The two sheets were then configured with the Melinex 453 PET treated side facing an untreated side of the Melinex 454 PET sheet. The configured sheets were inserted into a two roll laminator having two different size rollers. One roller is a 16 mm diameter rubber coated roller, 9″ in length with a shore hardness of 30 and the other roller is a 30 mm diameter aluminum roller 9″ in length. The rollers were closed, thereby pinching the configured sheets at a pressure of 5 psig pneumaticaly driven together by two steel cylinders of 1.5″ diameter with 1″ of the layers protruding beyond the exit side of the rollers. Approximately 2 mL of the dual-cure mixture was placed between the two PET sheets near the nip point on the input side of the rollers. The dual-cure was deposited in an even bead manner from a syringe having an opening of about 1 mm. The two roll laminator was then actuated at a speed of 3 ft/minute, driving the configuration through the nips and dispersing the dual-cure mixture between the two PET sheets and sealing the two PET sheets together with a thin film of dual-cure resin in between. The two roll laminator was stopped prior to the two PET sheets passing completely through the nip point, such that about 1 inch of PET remained above the input side of the rollers.
Step 3: The Melinex 454 PET/dual-cure resin/Melinex 453 PET laminate was then UV cured in a UV flood lamp (ELC-4001 from Electro-Lite Corp, Bethel, Conn.) (Mercury arc lamp with an output range of 290-420 nm (365 nm peak)) and illuminated for 1 minute at approximately 3 inches from the lamp. Prior to subjecting the Melinex 454 PET/dual-cure resin/Melinex 453 PET laminate to the UV cure, the UV flood lamp was allowed to warm-up for about 10 minutes to reach full operating potential.
Step 4: Next, the UV-cured Melinex 454 PET/dual-cure resin/Melinex 453 PET laminate was placed in a thermal oven set at, and preheated to, 100° C. for 10 minutes. Following this, the laminate was allowed to cool at room temperature for 1 minute before the PET sheets were separated by hand by peeling the two PET sheets apart at a rate of about 1 inch per second. The sheets separated cleanly with the dual-cure resin remaining on the Melinex 454 PET sheet of the laminate and the Melinex 453 treated side peeling off free of dual-cure resin.
Step 5: Separately, the UV curable PFPE resin, having the formula in Scheme 2 of Example 1, was mixed by hand for more than about 2 minutes at room temperature in a glass vial with 2.0% by weight diethoxyacetophenone.
Step 6: Next, a 6″ silicon master containing a patterned array of 2 μm×2 μm×0.7 μm cuboidal posts was configured with the Melinex 454 PET/dual-cure laminate sheet, formed in Steps 1-4, such that the dual-cure side was facing the patterned side of the wafer. The laminate and the wafer were inserted into a two roll laminator having two different size rollers. One roller is a 16 mm diameter rubber coated roller, 9″ in length with a shore hardness of 30 and the other roller is a 30 mm diameter aluminum roller 9″ in length. The rollers were closed, thereby pinching the configured sheets at a pressure of 5 psig pneumaticaly driven together by two steel cylinders of 1.5″ diameter with 1″ of the layers protruding beyond the exit side of the rollers. Approximately 1 mL of the UV-curable PFPE compound, described in Step 5, was evenly placed between the Melinex 454 PET/dual-cure sheet and the wafer near the nip point on the inlet side of the rollers. The UV-curable PFPE was disposed in a bead pattern from a syringe having an opening of about 1 mm. The laminator was then actuated at a speed of 3 ft/minute, laminating the Melinex 454 PET/dual cure sheet to the 6″ patterned wafer with a thin film of UV-curable PFPE distributed in between. The two roll laminator was then stopped when about 1 inch of the Melinex 454 PET/dual-cure laminate/UV-curable PFPE/silicon master remained on the inlet side of the rollers. The rollers were carefully opened to release the Melinex 454 PET/dual-cure laminate/UV-curable PFPE/silicon master laminate.
Step 7: The Dual cure sheet/UV-curable PFPE/Silicon wafer laminate was exposed to UV light through the Melinex 454 PET sheet using a UV flood lamp (ELC-4001 from Electro-Lite Corp, Bethel, Conn.) (Mercury arc lamp with an output range of 290-420 nm (365 nm peak)) and were illuminated for 1 minute approximately 3 inches from the lamp. Prior to exposing the dual-cure sheet/UV-curable PFPE/silicon wafer laminate to the UV floodlamp, the UV light source was allowed to warm up for 10 minutes. After exposure for 10 minutes, the light was extinguished and the dual-cure sheet/UV-curable PFPE/silicon wafer laminate was removed. Following removal from the floodlamp, the dual-cure sheet/UV-curable PFPE layer was carefully separated, by hand peeling at about 1 inch per second from the silicon master. Upon separation, a thin (10-20 micron) PFPE layer was adhered to the dual-cure adhered to the PET and the thin PFPE layer included features of the etched silicon wafers.
Example 4
Step 1: To form an adhesion promoter for PFPE molds to PET, a dual-cure composition of the PFPE structures, shown in Scheme 1 of Example 1, was mixed by hand stir for at least 2 minutes at room temperature in a glass vial. In particular, the dual-cure composition of PFPE structures includes the structures shown in Scheme 1 of Example 1 with 2.0% by weight diethoxyacetophenone photoinitiator and 0.1% by weight dibutyltin diacetate catalyst.
Step 2: One 6″×12″×7 mil sheet of Melinex 453 (Dupont Teijin Films) poly(ethylene terephthalate) (PET) and one 6″×12″×4 mil sheet of Melinex 582 (carboxyl functionalized) (Dupont Teijin Films) PET were prepared. The two sheets were then configured with the Melinex 453 PET treated side facing an untreated side of the Melinex 582 PET sheet. The configured sheets were inserted into a two roll laminator having two different size rollers. One roller is a 16 mm diameter rubber coated roller, 9″ in length with a shore hardness of 30 and the other roller is a 30 mm diameter aluminum roller 9″ in length. The rollers were closed, thereby pinching the configured sheets at a pressure of 5 psig pneumaticaly driven together by two steel cylinders of 1.5″ diameter with 1 inch of the layers protruding beyond the exit side of the rollers. Approximately 2 mL of the dual-cure mixture was placed between the two PET sheets near the nip point on the input side of the rollers. The dual-cure was deposited in an even bead manner from a syringe having an opening of about 1 mm. The two roll laminator was then actuated at a speed of 3 ft/minute, driving the configuration through the nips and dispersing the dual-cure mixture between the two PET sheets and sealing the two PET sheets together with a thin film of dual-cure resin in between. The two roll laminator was stopped prior to the two PET sheets passing completely through the nip point, such that about 1 inch of PET remained above the input side of the rollers.
Step 3: The Melinex 582 PET/dual-cure resin/Melinex 453 PET laminate was then UV cured in a UV flood lamp (ELC-4001 from Electro-Lite Corp, Bethel, Conn.) (Mercury arc lamp with an output range of 290-420 nm (365 nm peak)) and illuminated for 1 minute at approximately 3 inches from the lamp. Prior to subjecting the Melinex 582 PET/dual-cure resin/Melinex 453 PET laminate to the UV cure, the UV flood lamp was allowed to warm-up for about 10 minutes to reach full operating potential.
Step 4: Next, the UV-cured Melinex 582 PET/dual-cure resin/Melinex 453 PET laminate was placed in a thermal oven set at, and preheated to, 100° C. for 10 minutes. Following this, the laminate was allowed to cool at room temperature for 1 minute before the PET sheets were separated by hand by peeling the two PET sheets apart at a rate of about 1 inch per second. The sheets separated cleanly with the dual-cure resin remaining on the Melinex 582 PET sheet of the laminate and the Melinex 453 treated side peeling off free of dual-cure resin.
Step 5: Separately, the UV curable PFPE resin, having the formula in Scheme 2 of Example 1, was mixed by hand for more than about 2 minutes at room temperature in a glass vial with 2.0% by weight diethoxyacetophenone.
Step 6: Next, a 6″ silicon master containing a patterned array of 2 μm×2 μm×1.4 μm cuboidal posts was configured with the Melinex 582 PET/dual-cure laminate sheet, formed in Steps 1-4, such that the dual-cure side was facing the patterned side of the wafer. The laminate and the wafer were inserted into a two roll laminator having two different size rollers. One roller is a 16 mm diameter rubber coated roller, 9″ in length with a shore hardness of 30 and the other roller is a 30 mm diameter aluminum roller 9″ in length. The rollers were closed, thereby pinching the configured sheets at a pressure of 5 psig pneumaticaly driven together by two steel cylinders of 1.5″ diameter with 1 inch of the layers protruding beyond the exit side of the rollers. Approximately 1 mL of the UV-curable PFPE compound, described in Step 5, was evenly placed between the Melinex 582 PET/dual-cure sheet and the wafer near the nip point on the inlet side of the rollers. The UV-curable PFPE was disposed in a bead pattern from a syringe having an opening of about 1 mm. The laminator was then actuated at a speed of 3 ft/minute, laminating the Melinex 582 PET/dual cure sheet to the 6″ patterned wafer with a thin film of UV-curable PFPE distributed in between. The two roll laminator was then stopped when about 1 inch of the Melinex 582 PET/dual-cure laminate/UV-curable PFPE/silicon master remained on the inlet side of the rollers. The rollers were carefully opened to release the Melinex 582 PET/dual-cure laminate/UV-curable PFPE/silicon master laminate.
Step 7: The Dual cure sheet/UV-curable PFPE/Silicon wafer laminate was exposed to UV light through the Melinex 582 PET sheet using a UV flood lamp (ELC-4001 from Electro-Lite Corp, Bethel, Conn.) (Mercury arc lamp with an output range of 290-420 nm (365 nm peak)) and were illuminated for 1 minute approximately 3 inches from the lamp. Prior to exposing the dual-cure sheet/UV-curable PFPE/silicon wafer laminate to the UV floodlamp, the UV light source was allowed to warm up for 10 minutes. After exposure for 10 minutes, the light was extinguished and the dual-cure sheet/UV-curable PFPE/silicon wafer laminate was removed. Following removal from the floodlamp, the dual-cure sheet/UV-curable PFPE layer was carefully separated, by hand peeling at about 1 inch per second from the silicon master. Upon separation, a thin (10-20 micron) PFPE layer was adhered to the dual-cure adhered to the PET and the thin PFPE layer included features of the etched silicon wafers.
Example 5
Step 1: To form an adhesion promoter for PFPE molds to PET, a dual-cure composition of the PFPE structures, shown in Scheme 1 of Example 1, was mixed by hand stir for at least 2 minutes at room temperature in a glass vial. In particular, the dual-cure composition of PFPE structures includes the structures shown in Scheme 1 of Example 1 with 2.0% by weight diethoxyacetophenone photoinitiator and 0.1% by weight dibutyltin diacetate catalyst.
Step 2: Two 6″×12″×7 mil sheets of Melinex 453 (Dupont Teijin Films) poly(ethylene terephthalate) (PET) were cut. The two sheets were then configured with a treated side of one sheet facing an untreated side of the other sheet, however, untreated side was treated with a 1 minute corona treatment. The configured sheets were inserted into a two roll laminator having two different size rollers. One roller is a 16 mm diameter rubber coated roller, 9″ in length with a shore hardness of 30 and the other roller is a 30 mm diameter aluminum roller 9″ in length. The rollers were closed, thereby pinching the configured sheets at a pressure of 5 psig pneumaticaly driven together by two steel cylinders of 1.5″ diameter with 1 inch of the layers protruding beyond the exit side of the rollers. Approximately 2 mL of the dual-cure mixture was placed between the two PET sheets near the nip point on the input side of the rollers. The dual-cure was deposited in an even bead manner from a syringe having an opening of about 1 mm. The two roll laminator was then actuated at a speed of 3 ft/minute, driving the configuration through the nips and dispersing the dual-cure mixture between the two PET sheets and sealing the two PET sheets together with a thin film of dual-cure resin in between. The two roll laminator was stopped prior to the two PET sheets passing completely through the nip point, such that about 1 inch of PET remained above the input side of the rollers.
Step 3: The PET/dual-cure resin/PET laminate was then UV cured in a UV flood lamp (ELC-4001 from Electro-Lite Corp, Bethel, Conn.) (Mercury arc lamp with an output range of 290-420 nm (365 nm peak)) and illuminated for 1 minute at approximately 3 inches from the lamp. Prior to subjecting the PET/dual-cure resin/PET laminate to the UV cure, the UV flood lamp was allowed to warm-up for about 10 minutes to reach full operating potential.
Step 4: Next, the UV-cured PET/dual-cure resin/PET laminate was placed in a thermal oven set at, and preheated to, 100° C. for 10 minutes. Following this, the PET/dual-cure/PET laminate was allowed to cool at room temperature for 1 minute before the PET sheets were separated by hand by peeling the two PET sheets apart at a rate of about 1 inch per second. The sheets separated cleanly with the dual-cure resin remaining on the 1 minute corona treated PET non-Melinex 453 side of the laminate and the Melinex 453 treated side peeling off free of dual-cure resin.
Step 5: Separately, the UV curable PFPE resin, having the formula in Scheme 2 of Example 1, was mixed by hand for more than about 2 minutes at room temperature in a glass vial with 2.0% by weight diethoxyacetophenone.
Step 6: Next, a 6″ silicon master containing a patterned array of 2 μm×2 μm×0.7 μm cuboidal posts was configured with the PET/dual-cure laminate sheet, formed in Steps 1-4, such that the dual-cure side was facing the patterned side of the wafer. The laminate and the wafer were inserted into a two roll laminator having two different size rollers. One roller is a 16 mm diameter rubber coated roller, 9″ in length with a shore hardness of 30 and the other roller is a 30 mm diameter aluminum roller 9″ in length. The rollers were closed, thereby pinching the configured sheets at a pressure of 5 psig pneumaticaly driven together by two steel cylinders of 1.5″ diameter with 1 inch of the layers protruding beyond the exit side of the rollers. Approximately 1 mL of the UV-curable PFPE compound, described in Step 5, was evenly placed between the PET/dual-cure sheet and the wafer near the nip point on the inlet side of the rollers. The UV-curable PFPE was disposed in a bead pattern from a syringe having an opening of about 1 mm. The laminator was then actuated at a speed of 3 ft/minute, laminating the PET/dual cure sheet to the 6″ patterned wafer with a thin film of UV-curable PFPE distributed in between. The two roll laminator was then stopped when about 1 inch of the PET/dual-cure laminate/UV-curable PFPE/silicon master remained on the inlet side of the rollers. The rollers were carefully opened to release the PET/dual-cure laminate/UV-curable PFPE/silicon master laminate.
Step 7: The Dual cure sheet/UV-curable PFPE/Silicon wafer laminate was exposed to UV light through the PET sheet using a UV flood lamp (ELC-4001 from Electro-Lite Corp, Bethel, Conn.) (Mercury arc lamp with an output range of 290-420 nm (365 nm peak)) and were illuminated for 1 minute approximately 3 inches from the lamp. Prior to exposing the dual-cure sheet/UV-curable PFPE/silicon wafer laminate to the UV floodlamp, the UV light source was allowed to warm up for 10 minutes. After exposure for 10 minutes, the light was extinguished and the dual-cure sheet/UV-curable PFPE/silicon wafer laminate was removed. Following removal from the floodlamp, the dual-cure sheet/UV-curable PFPE layer was carefully separated, by hand peeling at about 1 inch per second from the silicon master. Upon separation, a thin (10-20 micron) PFPE layer was adhered to the dual-cure adhered to the PET and the thin PFPE layer included features of the etched silicon wafers.
Example 6
Step 1: To form an adhesion promoter for PFPE molds to polycarbonate, a dual-cure composition of the PFPE structures, shown in Scheme 1 of Example 1, was mixed by hand stir for at least 2 minutes at room temperature in a glass vial. In particular, the dual-cure composition of PFPE structures includes the structures shown in Scheme 1 of Example 1 with 2.0% by weight diethoxyacetophenone photoinitiator and 0.1% by weight dibutyltin diacetate catalyst.
Step 2: One 6″×12″×7 mil sheet of Melinex 453 (Dupont Teijin Films) poly(ethylene terephthalate) (PET) and one 6″×12″×6.5 mil sheet of polycarbonate (PC) were cut. The two sheets were then configured with a treated side of the PET sheet facing the sheet of PC. The configured sheets were inserted into a two roll laminator having two different size rollers. One roller is a 16 mm diameter rubber coated roller, 9″ in length with a shore hardness of 30 and the other roller is a 30 mm diameter aluminum roller 9″ in length. The rollers were closed, thereby pinching the configured sheets at a pressure of 5 psig pneumaticaly driven together by two steel cylinders of 1.5″ diameter with 1 inch of the layers protruding beyond the exit side of the rollers. Approximately 2 mL of the dual-cure mixture was placed between the PET/PC sheets near the nip point on the input side of the rollers. The dual-cure was deposited in an even bead manner from a syringe having an opening of about 1 mm. The two roll laminator was then actuated at a speed of 3 ft/minute, driving the configuration through the nips and dispersing the dual-cure mixture between the PET/PC sheets and sealing the PET/PC sheets together with a thin film of dual-cure resin in between. The two roll laminator was stopped prior to the PET/PC sheets passing completely through the nip point, such that about 1 inch of the PET/PC sheets remained above the input side of the rollers.
Step 3: The PC/dual-cure resin/PET laminate was then UV cured in a UV flood lamp (ELC-4001 from Electro-Lite Corp, Bethel, Conn.) (Mercury arc lamp with an output range of 290-420 nm (365 nm peak)) and illuminated for 1 minute at approximately 3 inches from the lamp. Prior to subjecting the PC/dual-cure resin/PET laminate to the UV cure, the UV flood lamp was allowed to warm-up for about 10 minutes to reach full operating potential.
Step 4: Next, the UV-cured PC/dual-cure resin/PET laminate was placed in a thermal oven set at, and preheated to, 100° C. for 10 minutes. Following this, the PC/dual-cure/PET laminate was allowed to cool at room temperature for 1 minute before the PET/PC sheets were separated by hand by peeling the PET/PC sheets apart at a rate of about 1 inch per second. The sheets separated cleanly with the dual-cure resin remaining on the PC side of the laminate and the Melinex 453 treated PET peeling off free of dual-cure resin.
Step 5: Separately, the UV curable PFPE resin, having the formula in Scheme 2 of Example 1, was mixed by hand for more than about 2 minutes at room temperature in a glass vial with 2.0% by weight diethoxyacetophenone.
Step 6: Next, a 6″ silicon master containing a patterned array of 2 μm×2 μm×0.7 μm cuboidal posts was configured with the PC/dual-cure laminate sheet, formed in Steps 1-4, such that the dual-cure side was facing the patterned side of the wafer. The laminate and the wafer were inserted into a two roll laminator having two different size rollers. One roller is a 16 mm diameter rubber coated roller, 9″ in length with a shore hardness of 30 and the other roller is a 30 mm diameter aluminum roller 9″ in length. The rollers were closed, thereby pinching the configured sheets at a pressure of 5 psig pneumaticaly driven together by two steel cylinders of 1.5″ diameter with 1 inch of the layers protruding beyond the exit side of the rollers. Approximately 1 mL of the UV-curable PFPE compound, described in Step 5, was evenly placed between the PC/dual-cure sheet and the wafer near the nip point on the inlet side of the rollers. The UV-curable PFPE was disposed in a bead pattern from a syringe having an opening of about 1 mm. The laminator was then actuated at a speed of 3 ft/minute, laminating the PC/dual cure sheet to the 6″ patterned wafer with a thin film of UV-curable PFPE distributed in between. The two roll laminator was then stopped when about 1 inch of the PC/dual-cure laminate/UV-curable PFPE/silicon master remained on the inlet side of the rollers. The rollers were carefully opened to release the PC/dual-cure laminate/UV-curable PFPE/silicon master laminate.
Step 7: The Dual cure sheet/UV-curable PFPE/Silicon wafer laminate was exposed to UV light through the PC sheet using a UV flood lamp (ELC-4001 from Electro-Lite Corp, Bethel, Conn.) (Mercury arc lamp with an output range of 290-420 nm (365 nm peak)) and were illuminated for 1 minute approximately 3 inches from the lamp. Prior to exposing the dual-cure sheet/UV-curable PFPE/silicon wafer laminate to the UV floodlamp, the UV light source was allowed to warm up for 10 minutes. After exposure for 10 minutes, the light was extinguished and the dual-cure sheet/UV-curable PFPE/silicon wafer laminate was removed. Following removal from the floodlamp, the dual-cure sheet/UV-curable PFPE layer was carefully separated, by hand peeling at about 1 inch per second from the silicon master. Upon separation, a thin (10-20 micron) PFPE layer was adhered to the dual-cure adhered to the PET and the thin PFPE layer included features of the etched silicon wafers.
Example 7
Step 1: To form an adhesion promoter for PFPE molds to silicon rubber, a dual-cure composition of the PFPE structures, shown in Scheme 1 of Example 1, was mixed by hand stir for at least 2 minutes at room temperature in a glass vial. In particular, the dual-cure composition of PFPE structures includes the structures shown in Scheme 1 of Example 1 with 2.0% by weight diethoxyacetophenone photoinitiator and 0.1% by weight dibutyltin diacetate catalyst.
Step 2: One 6″×12″×7 mil sheet of Melinex 453 (Dupont Teijin Films) poly(ethylene terephthalate) (PET) and one 6″×12″×10 mil sheet of corona treated silicone rubber (SR) were cut. The two sheets were then configured with the corona treated side of the silicone rubber sheet facing a treated side of the PET sheet. The configured sheets were inserted into a two roll laminator having two different size rollers. One roller is a 16 mm diameter rubber coated roller, 9″ in length with a shore hardness of 30 and the other roller is a 30 mm diameter aluminum roller 9″ in length. The rollers were closed, thereby pinching the configured sheets at a pressure of 5 psig pneumaticaly driven together by two steel cylinders of 1.5″ diameter with 1 inch of the layers protruding beyond the exit side of the rollers. Approximately 2 mL of the dual-cure mixture was placed between the SR/PET sheets near the nip point on the input side of the rollers. The dual-cure was deposited in an even bead manner from a syringe having an opening of about 1 mm. The two roll laminator was then actuated at a speed of 3 ft/minute, driving the configuration through the nips and dispersing the dual-cure mixture between the SR/PET sheets and sealing the SR/PET sheets together with a thin film of dual-cure resin in between. The two roll laminator was stopped prior to the SR/PET sheets passing completely through the nip point, such that about 1 inch of SR/PET remained above the input side of the rollers.
Step 3: The SR/dual-cure resin/PET laminate was then UV cured in a UV flood lamp (ELC-4001 from Electro-Lite Corp, Bethel, Conn.) (Mercury arc lamp with an output range of 290-420 nm (365 nm peak)) and illuminated for 1 minute at approximately 3 inches from the lamp. Prior to subjecting the SR/dual-cure resin/PET laminate to the UV cure, the UV flood lamp was allowed to warm-up for about 10 minutes to reach full operating potential.
Step 4: Next, the UV-cured SR/dual-cure resin/PET laminate was placed in a thermal oven set at, and preheated to, 100° C. for 10 minutes. Following this, the SR/dual-cure/PET laminate was allowed to cool at room temperature for 1 minute before the SR/PET sheets were separated by hand by peeling the SR/PET sheets apart at a rate of about 1 inch per second. The sheets separated cleanly with the dual-cure resin remaining on the SR sheet and the Melinex 453 treated PET side peeling off free of dual-cure resin.
Step 5: Separately, the UV curable PFPE resin, having the formula in Scheme 2 of Example 1, was mixed by hand for more than about 2 minutes at room temperature in a glass vial with 2.0% by weight diethoxyacetophenone.
Step 6: Next, a 6″ silicon master containing a patterned array of 2 μm×2 μm×1.4 μm cuboidal posts was configured with the SR/dual-cure laminate sheet, formed in Steps 1-4, such that the dual-cure side was facing the patterned side of the wafer. The laminate and the wafer were inserted into a two roll laminator having two different size rollers. One roller is a 16 mm diameter rubber coated roller, 9″ in length with a shore hardness of 30 and the other roller is a 30 mm diameter aluminum roller 9″ in length. The rollers were closed, thereby pinching the configured sheets at a pressure of 5 psig pneumaticaly driven together by two steel cylinders of 1.5″ diameter with 1 inch of the layers protruding beyond the exit side of the rollers. Approximately 1 mL of the UV-curable PFPE compound, described in Step 5, was evenly placed between the SR/dual-cure sheet and the wafer near the nip point on the inlet side of the rollers. The UV-curable PFPE was disposed in a bead pattern from a syringe having an opening of about 1 mm. The laminator was then actuated at a speed of 3 ft/minute, laminating the SR/dual cure sheet to the 6″ patterned wafer with a thin film of UV-curable PFPE distributed in between. The two roll laminator was then stopped when about 1 inch of the SR/dual-cure laminate/UV-curable PFPE/silicon master remained on the inlet side of the rollers. The rollers were carefully opened to release the SR/dual-cure laminate/UV-curable PFPE/silicon master laminate.
Step 7: The Dual cure sheet/UV-curable PFPE/Silicon wafer laminate was exposed to UV light through the SR sheet using a UV flood lamp (ELC-4001 from Electro-Lite Corp, Bethel, Conn.) (Mercury arc lamp with an output range of 290-420 nm (365 nm peak)) and were illuminated for 1 minute approximately 3 inches from the lamp. Prior to exposing the dual-cure sheet/UV-curable PFPE/silicon wafer laminate to the UV floodlamp, the UV light source was allowed to warm up for 10 minutes. After exposure for 10 minutes, the light was extinguished and the dual-cure sheet/UV-curable PFPE/silicon wafer laminate was removed. Following removal from the floodlamp, the dual-cure sheet/UV-curable PFPE layer was carefully separated, by hand peeling at about 1 inch per second from the silicon master. Upon separation, a thin (10-20 micron) PFPE layer was adhered to the dual-cure adhered to the SR and the thin PFPE layer included features of the etched silicon wafers.
Example 8
Step 1: To form an adhesion promoter for PFPE molds to PET, a dual-cure composition of the PFPE structures, shown in Scheme 1 of Example 1, was mixed by hand stir for at least 2 minutes at room temperature in a glass vial. In particular, the dual-cure composition of PFPE structures includes the structures shown in Scheme 1 of Example 1 with 2.0% by weight diethoxyacetophenone photoinitiator and 0.1% by weight dibutyltin diacetate catalyst.
Step 2: One 6″×12″×7 mil sheet of untreated poly(ethylene terephthalate) (PET) was cut. The PET sheet was configured adjacent a 6″ silicon master containing a patterned array of 2 μm×2 μm×1.4 μm cuboidal posts. The configured PET sheet/silicon wafer master were inserted into a two roll laminator having two different size rollers. One roller is a 16 mm diameter rubber coated roller, 9″ in length with a shore hardness of 30 and the other roller is a 30 mm diameter aluminum roller 9″ in length. The rubber roller was positioned adjacent the silicon master and the aluminum roller was positioned adjacent the PC. The rollers were closed, thereby pinching the configured sheets at a pressure of 5 psig pneumaticaly driven together by two steel cylinders of 1.5″ diameter with 1 inch of the layers protruding beyond the exit side of the rollers. Approximately 2 mL of the dual-cure mixture was placed between the PET/master configuration near the nip point on the input side of the rollers. The dual-cure was deposited in an even bead manner from a syringe having an opening of about 1 mm. The two roll laminator was then actuated at a speed of 3 ft/minute, driving the configuration through the nips and dispersing the dual-cure mixture between the PET/master configuration and sealing the PET/master configuration together with a thin film of dual-cure resin in between. The two roll laminator was stopped prior to the PET/master configuration passing completely through the nip point, such that about 1 inch of PET/master configuration remained above the input side of the rollers.
Step 3: The PET/dual-cure resin/master laminate was then UV cured in a UV flood lamp (ELC-4001 from Electro-Lite Corp, Bethel, Conn.) (Mercury arc lamp with an output range of 290-420 nm (365 nm peak)) and illuminated for 3 minutes at approximately 3 inches from the lamp. Prior to subjecting the PET/dual-cure resin/master laminate to the UV cure, the UV flood lamp was allowed to warm-up for about 10 minutes to reach full operating potential.
Step 4: Next, the UV-cured PET/dual-cure resin/master laminate was placed in a thermal oven set at, and preheated to, 115° C. for 3 hours. Following this, the PET/dual-cure/master laminate was allowed to cool at room temperature for 1 minute before the PET sheet was separated from the master by hand by peeling the PET sheet away at a rate of about 1 inch per second. Following this, the PET/dual-cure laminate was separated cleanly from the master wafer to reveal a patterned dual-cure mold adhered to the PET.
Example 9
Step 1: To form an adhesion promoter for PFPE molds to PET, a UV curable composition of the PFPE structures, shown in Scheme 2 of Example 1, was mixed by hand stir for at least 2 minutes at room temperature in a glass vial. In particular, the UV-curable composition of PFPE structures includes the structure shown in Scheme 2 of Example 1 and 2.0% by weight diethoxyacetophenone.
Step 2: One 6″×12″×6.5 mil sheet of polycarbonate (PC) was cut. The PC sheet was configured adjacent a 6″ silicon master containing a patterned array of 2 μm×2 μm×1.4 μm cuboidal posts. The configured PC/silicon master was inserted into a two roll laminator having two different size rollers. One roller is a 16 mm diameter rubber coated roller, 9″ in length with a shore hardness of 30 and the other roller is a 30 mm diameter aluminum roller 9″ in length. The rubber coated roller was positioned adjacent the silicon master and the aluminum roller was positioned adjacent the PC. The rollers were closed, thereby pinching the configured sheets at a pressure of 5 psig pneumaticaly driven together by two steel cylinders of 1.5″ diameter with 1 inch of the layers protruding beyond the exit side of the rollers. Approximately 2 mL of the UV-curable mixture was placed between the PC/master configuration near the nip point on the input side of the rollers. The UV-curable mixture was deposited in an even bead manner from a syringe having an opening of about 1 mm. The two roll laminator was then actuated at a speed of 3 ft/minute, driving the configuration through the nips and dispersing the UV-curable mixture between the PC/master configuration and sealing the PC/master configuration together with a thin film of UV-curable mixture in between. The two roll laminator was stopped prior to the PC/master configuration passing completely through the nip point, such that about 1 inch of PC/master configuration remained above the input side of the rollers.
Step 3: The PC/UV-curable mixture/master laminate was then UV cured in a UV flood lamp (ELC-4001 from Electro-Lite Corp, Bethel, Conn.) (Mercury arc lamp with an output range of 290-420 nm (365 nm peak)) and illuminated for 3 minutes at approximately 3 inches from the lamp. Prior to subjecting the PC/UV-curable mixture/master laminate to the UV cure, the UV flood lamp was allowed to warm-up for about 10 minutes to reach full operating potential.
Step 4: Next, the PC/UV-curable mixture laminate was separated cleanly from the master wafer to reveal a patterned UV-curable mold adhered to the PC.
Example 10
Gel Fraction
Dual cure materials are synthesized as given previously. For each sample, approximately 2 g of uncured material is weighed into a 20 mL glass vial of known weight. Between samples, the material is stored in a desiccator. For thermal tests, the vials are labeled as T1-T7, for uv curing, the vials are labeled as U1-U6. IR spectra were taken of all samples. FIGS. 7A and 7B are graphs showing sample IR data.
For the thermal cure tests, a digital convection oven is set to 100° C. The vial is placed in the oven for the determined amount of time (10 sec, 30 sec, 1 min, 2 min, 4 min, 8 min, or 12 min). The vial is removed from the oven and allowed to cool to room temperature. The sample is checked for fiber formation using tweezers, in a manner similar to a “toothpick test”, known to those skilled in the art. The sample vial is then filled with approximately 20 mL of SOLKANE™ (1,1,1,3,3-pentafluorobutane) (Solvay Solexis, Brussels, Belgium) and shaken for 2 minutes to extract the sol fraction. The liquid is decanted off and passed through a 45 μm filter into a glass vial of known weight, labeled as T1a, T2a, etc. All vials are placed in a vacuum oven and taken to dryness (about 2 hours). The vials are weighed to determine the masses of the sol fraction and gelled material.
For the uv cure tests, a low power uv oven (24-28 mW/cm 2 at 365 nm) provided by Electro-lite (Electro-Lite Corporation, Bethel, Conn.). The vial is placed in the uv oven, purged with nitrogen for 2 minutes, then cured for the determined amount of time (10 sec, 30 sec, 1 min, 2 min, 4 min, 8 min, or 12 min). The vial is removed from the uv oven. The sample is checked for fiber formation using tweezers, in a manner similar to a “toothpick test”, known to those skilled in the art. The sample vial is then filled with approximately 20 mL of SOLKANE™ (1,1,1,3,3-pentafluorobutane) (Solvay Solexis, Brussels, Belgium) and shaken for 2 minutes to extract the sol fraction. The liquid is decanted off and passed through a 45 μm filter into a glass vial of known weight, labeled as U1a, U2a, etc. All vials are placed in a vacuum oven and taken to dryness (about 2 hours). The vials are weighed to determine the masses of the sol fraction and gelled material.
Results of Solgel Fraction Study:
Vial #
Cure type
Cure time
% sol fraction
T1
Thermal
10
sec
91.56
T2
Thermal
30
sec
52.57
T3
Thermal
60
sec
32.58
T4
Thermal
2
min
11.6
T5
Thermal
4
min
20.23
T6
Thermal
8
min
7.71
T7
Thermal
12
min
8.81
U1
UV
10
sec
76.49
U2
UV
30
sec
81.5
U3
UV
60
sec
23.33
U4
UV
2
min
16.21
U5
UV
4
min
3.16
U6
UV
8
min
0.85
Tweezer Test
Sample
Result
T1
N
T2
N
T3
Y/N
T4
Y
T5
Y
T6
Y
T7
Y
U1
N
U2
Y/N
U3
Y
U4
Y
U5
Y
U6
Y
Y/N means no fibers initially, but when SOLKANE ™ is added, a few fibers can be seen in solution
Samples having properties appropriate for the present applications include #s T6 and T7 (thermally cured at 100° C. for greater than 8 min.) and U5 and U6 (UV cured at 24-28 mW/cm 2 at 365 nm for greater than 4 min).
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A laminate nanomold includes a layer of perfluoropolyether defining a cavity that has a predetermined shape and a support layer coupled with the layer of perfluoropolyether. The laminate can also include a tie-layer coupling the layer of perfluoropolyether with the support layer. The tie-layer can also include a photocurable component and a thermal curable component. The cavity can have a broadest dimension of less than 500 nanometers.
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[0001] The present invention relates to a method and system for the distribution of multimedia tracks through computer networks, magnetic media and personal computers in general.
BACKGROUND OF THE INVENTION
[0002] Currently, several kinds of methods and commercial tools are used to distribute music or video files through computer networks, particularly the Internet which, thanks to its millions of users, is one of the most interesting and effective markets but is also a source of illegal distribution of material.
[0003] The turnover and competition involved in the music/motion picture market therefore continuously require new methods and systems for promoting songs, videos and films, and at the same time for protecting the rights of the owner on copyrighted products. Until recently, promotion and distribution of songs, videos and films were performed almost exclusively through radio and television channels in a variety of programs. In this manner, the audio/video content, although copyrighted, reaches simultaneously a plurality of users in a manner that is completely cost-free for them, the costs of the promotion of the material being borne entirely by sponsors or advertisers. In recent years, the rapid growth of the Internet and the new technologies used to encode multimedia files on computer media have attracted the attention of millions of users. It is now possible to encode any audio/video track in a multimedia file in different formats and play it on a normal personal computer, and most of all to make a copy thereof without compromising at all the audio/video quality of the source file.
[0004] Moreover, the Internet makes it very easy to browse through a large quantity of archives that are available worldwide, looking for specific titles and finally downloading the desired multimedia track: recent market research has demonstrated that one of the most widely searched terms on the Internet is the word “MP3”, which refers to audio files encoded in a well-known compressed format.
[0005] In order to listen to an MP3 audio file, or likewise play a file that also contains video, for example encoded according to the MPEG4 standard, the user requires an MP3 or MP4 player. MP3/MP4 players are generally available in the form of a hardware apparatus or of a software application that runs on the personal computer of the user. Many MP3 and MP4 players are provided for free, and so are many MP3 audio and MP4 video files. The quality of MP3 files is very high, not far from that of a normal CD. Moreover, MP3s are much smaller in terms of size than their CD counterparts, approximately in a ratio of 1:12, which makes them suitable for downloading from a computer network, particularly the Internet.
[0006] Of course, Internet sites cannot legally provide MP3 files of copyrighted material unless authorized by the author or owner.
[0007] However, the very nature of the MP3 digital file, which can be played by any player that is compatible with the standard, makes copying of the audio track by means of user-to-user exchanges, without as mentioned any loss of quality between the copy and the original, extremely easy and uncontrollable.
[0008] The file protection attempts made so far are based substantially on protection by means of DRM schemes, which allow to play back the track with limitations (for example, only on the device indicated by the user at the time of purchase). However, even this protection is in practice scarcely useful, since while the audio/video file is being played by the player, it is in any case possible to make a simultaneous recording of the audio or video by means of conventional software programs, which generate an unprotected MP3 or MP4 file, once again without any loss of quality.
[0009] Likewise, it is in any case not unusual for the buyer of a CD or DVD to convert the files into MP3/MP4 format in order to then make them available for peer-to-peer exchanges, i.e., directly from a user's computer to another user's computer, by means of known programs for sharing and swapping files in general, such as e-Mule, BitTorrent and KaZaa, just to mention the best-known ones.
[0010] In the background art, attempts at music file distribution of the peer-to-peer type in a controlled manner are known. In particular, U.S. patent application Ser. No. 10/029,997 discloses a method for distributing music files in encrypted and tagged form in order to identify the chain of users who transferred the product. The encrypted file receives the addition of a portion of the same music content in unencrypted form, so as to allow to listen to part of the track.
SUMMARY OF THE INVENTION
[0011] The aim of the present invention is to provide a method and a system for distributing music, films and videos, including copyrighted material, through a computer network, particularly the Internet, that overcome the problems observed above with reference to the background art.
[0012] Within this aim, an object of the present invention is to provide a method and a system that overcome the problem of the impossibility of protecting multimedia files, dissuading the user from illegally circulating copyrighted audio tracks and instead providing the user with an incentive to purchase the file legally.
[0013] A further object of the present invention is to provide a method and a system that do not encumber unnecessarily the quantity of data to be exchanged, avoiding in particular redundancies in content.
[0014] Another object of the present invention is to provide a method and a system that make a music file encoded according to the system preliminarily indistinguishable from a music file deposited according to the conventional method, for example in the MP3 format.
[0015] Still another object of the present invention is to provide a method and a system that allow authors and producers of music and of other multimedia content to approach the maximum possible number of users, by converting Internet channels from illegal distribution channels to channels for promoting their content.
[0016] This aim, these objects and others that will become better apparent hereinafter are achieved by a method for distributing music files through a computer network, comprising the steps of: selecting an audio/video track encoded in a digital file according to a conventional encoding which comprises a header and a division into frames; converting a plurality of said conventionally encoded frames into encrypted frames; applying a digital signature in the header; generating an audio file which comprises a signed header, a plurality of frames with conventional encoding and a plurality of encrypted frames.
[0017] This aim and these objects are also achieved by a digital file for personal computers, comprising a header which comprises a digital signature and a division into frames, said frames being divided into frames that are encoded according to conventional encoding and encrypted frames, and by a data encoder for personal computers, comprising means for applying a digital signature to a digital file which comprises a header and a division into frames, said frames being divided into frames that are encoded according to conventional encoding and encrypted frames.
[0018] Advantageously, such conventional encoding is MP3 encoding for music files and MP4 for films/videos.
[0019] Conveniently, the plurality of frames with conventional encoding comprises the initial sequence of consecutive frames that constitute the audio file and the plurality of encrypted frames comprises a sequence of consecutive frames.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Further characteristics and advantages of the present invention will become better apparent from the following detailed description, given by way of non-limiting example and illustrated in the accompanying drawings, wherein:
[0021] FIG. 1 is a schematic view of a network system used to distribute music/video files encoded according to the present invention;
[0022] FIG. 2 is a block diagram of a file that is encoded conventionally in the MP3 format;
[0023] FIG. 3 is a block diagram that represents a file encoded in the MP3 format and partially encrypted.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] FIG. 1 is a general view of a preferred embodiment of the architecture of the system, where a user computer station 2 accesses, through a computer network, particularly the Internet, a server 1 of a service provider that acts as an operator and certifier in the management of music files 20 distributed through official distributors 3 or peer-to-peer networks 4 .
[0025] In greater detail, the server 1 of the certifier contains means for verifying the authenticity of the data sent by the client 2 and for providing the information needed to apply digital signatures to music files 20 , as will be explained hereinafter.
[0026] The client 2 is an application, to be installed at the station of each user, that allows to select music files 20 and, under the control of the server 1 and/or in cooperation with it, to apply thereto one's own digital signature, so as to generate a version of the music file 20 ′ that can be associated with the user.
[0027] The authorized distributors 3 represent all the distributors that put on the market music/video files stored on digital media, be they CDs, DVDs, memory cards or others, or distributors that allow to download directly onto one's own computer the music files one is interested in, according to the most recent distribution models.
[0028] The peer-to-peer networks 4 instead represent all the applications that allow to share among users in a network files of any kind and are often used for the unauthorized sharing and distribution of copyrighted material.
[0029] The music file 10 is an audio/video file encoded according to any encoding mode that can be understood by an audio/video player. By way of non-limiting example, the present description will always reference files encoded in the MP3/MP4 format, since these standards are the best-known and most widespread commercially for the encoding of music and video files. However, files that use similar structures, such as files in the XVID, DIVX or Ogg/Vorbis format are of course suitable for the application of the invention.
[0030] It should be noted that for the sake of simplicity in explanation, the present description refers to files of the musical type, and specifically to files of the MP3 type. However, this description must be understood merely as a non-limiting example, since the same considerations apply to any type of multimedia file, i.e., audio, video or audio-video, constituted by a frame composed of a succession of fields.
[0031] The MP3 file 10 is shown in greater detail in FIG. 2 , where it is shown that the MP3 file, like most files encoded according to any other layer of the MPEG standard, is constituted by a sequence of independent frames, each of which is independent.
[0032] In particular, FIG. 2 illustrates a first portion 11 of the file, identified as ID3 area, which stores corollary data, such as for example data related to the ownership of the file, such as the Author, Major, Producer, Internet retailer, distributor and so forth.
[0033] FIG. 3 instead illustrates an audio file 20 that is signed and encrypted according to the present invention.
[0034] In this case, the header area 21 bears, in addition to the data mentioned above, also the digital signature of the client 2 used by the user or a unique identifier that acts as a key to associate the data mentioned above, such as the Author, Major, producer, Internet retailer and so forth, on the server side.
[0035] Moreover, there is therein a first plurality of frames 22 encoded according to the standard and left unencrypted and a second plurality of encrypted frames 23 . In this manner, the portion 22 of the music file can still be played by means of any MP3 player, while the portion 23 cannot be played, since the encryption process compromises the possibility of interpretation by a conventional player.
[0036] Operation of the system is as follows.
[0037] A first user 2 personally produces a music file and identifies himself and accredits himself at the server 1 .
[0038] Otherwise, he comes into possession of an unencrypted music file, for example by purchasing a file on the Internet or on a memory medium, in the form of a CD, a DVD, a memory card or any other medium suitable to store digital data, through authorized distributors 3 . The medium contains, in addition to the music files in a format that can be played by means of the corresponding player, also a copy 20 of the files encoded in MP3 format and partially encrypted, each containing its own identification code.
[0039] The memory medium, or its package, bears internally, in electronic and/or paper format, the access keys that allow the user, once he has connected to an appropriately provided Internet site, which in turn is connected to the server 1 , to identify himself as a user who has regularly purchased the content of the CD and the unlocking code of the tracks 20 .
[0040] Likewise, if the distributor is a distributor of music in digital format over the Internet that allows the user to download music directly into his own personal computer, the user can be provided with two versions of the tracks that he has selected: a freely playable version 10 and an encrypted version, accompanied by the same information mentioned above.
[0041] Both encoding and encryption can of course be performed by using any appropriate encoding or encryption algorithm, widely known in computer literature, as well as proprietary protection schemes or algorithms that are compatible with the formats used.
[0042] Once the user 2 has come into possession of the audio/video files he is interested in, in addition to playing the audio or video, he may decide, as often occurs, to share them with the other users of the network by means of peer-to-peer channels. However, instead of circulating the normally encoded and freely playable version, by means of the client 2 he applies, if it is not already present in the file 20 received from the distributor, his own signature in the portion 21 of the encrypted file 20 and circulates the partially encrypted version of the track.
[0043] At this point, a third user who might come into possession of the file 20 will be able to play back only the portion 22 of the music file 20 .
[0044] However, by connecting to the server 1 he will be able to notify to the server 1 his intention to purchase a copy of the track, by using the file 20 , or the digital signature contained therein, as a starting point, thus generating an income, in the form of a refund or credit according to appropriate cost schemes that are beyond the technical context of the present invention, for the user who circulated the encrypted or partially encrypted file 20 and for the other rights holders (Author, Major, et cetera).
[0045] As a consequence of the purchase made, the third user also receives a copy of the file 20 that is partially encrypted and which he can decide in turn to circulate after applying his own digital signature in the section 21 .
[0046] It has been shown that the present method and system achieve the intended aim and objects. Since the user obtains a tangible benefit from the distribution of music/video files in partially encrypted form according to the described schemes, he in fact loses interest in circulating illegal copies of the music tracks.
[0047] At the same time, the possibility of economic returns on purchase by other users, encouraged by the partial playing of the file 20 , of such track, prompts the user to circulate the encrypted files as much as possible, contributing to the distribution of the track, to the full benefit of the author, of the distributor and all the chain of the rights holders, who benefit, and no longer suffer, from the distribution of files over the computer network.
[0048] Moreover, thanks to the encryption of frames in a separate manner, it is possible to keep portions of the track unencrypted, so as to allow partial playing thereof without having to replicate content in a redundant manner. Likewise, the structure of the file remains unchanged, thus making the content of the file encoded according to the teachings of the invention formally indistinguishable from a corresponding file encoded in a conventional manner.
[0049] Numerous modifications are clearly possible and can be readily performed by the person skilled in the art without abandoning the scope of the protection of the present invention. For example, it is clear that the present invention can be applied also for the distribution of music/video files independently of the Internet. A financial sponsor, for example, might use the method according to the present invention to generate executable software files that can be distributed through different channels, for example on compact discs included in music or computer magazines or as bonuses in video games or computer programs in general. Moreover, it is equally evident that the application of the digital signature in the portion 21 of the file 20 can be performed directly by the server 1 or by the distributor 3 if the user has been identified, and that such digital signature can replace preceding signatures or be added to them in order to generate repayment schemes of a different type (for example of the type known as “multilevel”).
[0050] Finally, it is clear that the operations for partial or total encryption of the file can be performed directly by the client 2 on the basis of his own digital signature.
[0051] Therefore, the scope of the protection of the claims must not be limited by the illustrations or by the preferred embodiments illustrated in the description by way of example, but rather the claims must include all the characteristics of patentable novelty that reside within the present invention, including all the characteristics that would be treated as equivalent by the person skilled in the art.
[0052] The disclosures in Italian Patent Application no. MI2008A000221, from which this application claims priority, are incorporated herein by reference.
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A method for distributing multimedia files through a computer network comprises the steps of selecting a multimedia track from an archive, encoded in a digital file according to a conventional encoding which comprises a header and a division into frames; converting a plurality of the conventionally encoded frames into encrypted frames; applying a digital signature in the header; generating an audio file which comprises a signed header, a plurality of frames with conventional encoding and a plurality of encrypted frames.
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BACKGROUND OF THE INVENTION
It is well known to use a vibration damper in a clutch assembly for a vehicle clutch ahead of a manually-operated transmission or in a torsional coupling between driving and driven shafts. Also, where a lock-up clutch is inserted into a torque converter of an automatic transmission, a vibration damper is necessary in the direct drive mode of the torque converter as the torsional vibrations will not be damped hydraulically.
In our earlier patent applications Ser. No. 801,989 filed May 31, 1977 now U.S. Pat. No. 4,188,805, and Ser. No. 860,348 filed Dec. 14, 1977, now U.S. Pat. No. 4,188,806, we disclosed torsional vibration dampers for various types of torsional couplings utilizing floating equalizers journalled on a hub connected to a driven shaft; such as a transmission input shaft. In each application two or more groups of springs operate in parallel with two or three spring sets in each group. In Ser. No. 801,989, the spring sets in each group are separated from each other to prevent rubbing and wear on the ends of the springs by the configuration of the arms of each floating equalizer. In Ser. No. 860,348, the arms of each equalizer provides a spring enclosure housing the ends of two adjacent spring sets and generally V-shaped locking dividers have tabs received in slots in the equalizer arms to retain the dividers therein and separate the springs.
SUMMARY OF THE INVENTION
The present invention relates to an improved spring separator or divider received in the oppositely disposed arms of a floating equalizer or transfer member. A self-locating divider is positioned in each equalizer arm to allow for any differences in damper spring set lengths. Each equalizer arm has axially aligned windows to receive the ends of the divider wherein each window can accumulate a relatively large variation in total length of the damper springs. The windows allow the divider to relocate and prevent uneven loading and a resultant possible failure mode.
The present invention also relates to an improved floating equalizer journalled on the hub of a torsional vibration damper which replaces a previous arrangement of two floating equalizers. The improved equalizer comprises a pair of plates joined together at pairs of oppositely disposed peripheral flanges and housing a substantial portion of the three spring sets in each of the two parallel groups. Two sets of axially aligned windows are located on each side of a centerline passing through the drive tangs and receive the ends of spring dividers. The windows are arcuate to allow a limited amount of movement of each divider under the force of the compressed springs when torque is applied to the assembly. Thus, both of the dividers are capable of movement along with the rotational movement of the equalizer.
Further objects are to provide a construction of maximum simplicity, efficiency, economy and ease of assembly and operation, and such further objects, advantages and capabilities as will later more fully appear and are inherently possessed thereby.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a rear elevational view of a torsional vibration damper assembly mounted on a piston plate of a torque converter lock-up clutch.
FIG. 2 is a cross sectional view of the assembly taken on the irregular line 2--2 of FIG. 1.
FIG. 3 is a rear elevational view partially in cross section of the vibration damper removed from the piston plate input means.
FIG. 4 is an enlarged elevational view of a self-locating divider in an equalizer.
FIG. 5 is a rear elevational view of a plate to form a floating equalizer.
FIG. 6 is an enlarged partial cross sectional view taken on the line 6--6 of FIG. 5.
FIG. 7 is an enlarged partial cross sectional view similar to FIG. 6 but with a portion of a divider shown in elevation.
FIG. 8 is an enlarged perspective view of the self-locating spring divider.
FIG. 9 is a rear elevational view of an alternate embodiment of vibration damper assembly connected to a piston plate.
FIG. 10 is an elevational view of a plate forming one side of a floating equalizer.
FIG. 11 is an enlarged partial elevational view of a self-locating divider in the equalizer.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring more particularly to the disclosure in the drawings wherein are shown illustrative embodiments of the present invention, FIGS. 1 through 3 disclose a torsional vibration damper assembly 10 adapted for use in a lock-up clutch for a torque converter (not shown) wherein a piston plate 11 provides an annular friction surface 12 adjacent the outer periphery 13 and has an inner annular flange 14 defining a central opening 15. Secured to the piston 11, such as by rivets 16, are a pair of oppositely disposed drive tangs 17, each having a generally arcuate base 18 and an offset projection 19 extending inwardly into the damper. The projection has inwardly converging edges generally coinciding with the edges of the hub arms.
A hub assembly 22 of the damper includes a hub barrel 23 and first and second hub plates 28 and 36, respectively, secured together by rivets 24. The hub barrel has a generally cylindrical body internally splined at 25 and having a shoulder 26 for a purpose to be described later and counterbored openings 27 for the rivets 24. The first hub plate 28 includes a flat annular body internally splined at 29 and having openings 31 for the rivets. Extending outwardly are a pair of oppositely disposed arms 32 slightly offset at 33 and terminating in circumferentially extending lips 34. The arms have outwardly diverging edges 35 generally aligned with the edges of the drive tang projections 19.
The second hub plate 36 also has a generally annular flat body internally splined at 37 and provided with openings 38 for the rivets. A pair of oppositely disposed arms 39 extend from the body and are slightly offset at 41. The arms have diverging edges 40 (FIG. 3) terminating in circumferentially extending fingers 42 substantially identical to those of the first plate 28. Extending axially forwardly of the plate 36 are a pair of oppositely disposed arcuate flanges 43 (FIG. 2) formed with exterior shoulders. When assembled, the splines 25, 29 and 37 of the barrel and first and second hub plates are axially aligned to receive the splined end of a transmission input shaft (not shown), and the rivets 24 extend through axially aligned openings 27, 31 and 38 and are headed to secure the three parts together. As seen in FIG. 2, the arms 32 and 39 of the first and second hub plates 28 and 36, respectively, are offset in opposite directions to form circumferentially extending slots 44 receiving the inwardly extending projections 19 of the drive tangs 17 therein.
A pair of floating equalizers 45 and 46 are journalled on the shoulder 26 and shoulders of flange 43 of the hub assembly 22, with each equalizer being formed of front and rear plates 47 and 48, respectively, the rear plate being shown in FIG. 5. This plate 48 has a generally annular flat portion 49 with a central opening 51 journalled on the shoulder 26, and a pair of oppositely disposed slightly outwardly and then inwardly curved arms 52, 52; approximately one-half of the arm curving to a greater extent to terminate in a peripheral flange 53 having spaced openings 54. Formed in the curved arm is a slightly elongated window 55, and an indented portion 56 is located immediately outwardly of the window. The remaining portion of the arm provides a curved edge 57 adapted to receive the hub arms 32, 39 in a manner to be later described.
The front equalizer plate 47 is substantially identical with the plate 48 except the arms, as seen in FIG. 2, have less total curvature. The peripheral flanges 53 of the pair of plates are suitably secured together, as by rivets 58 received in the openings 54. The plates of the equalizer 45 are journalled on the shoulders 26, 43 inside of the plates for equalizer 46 as seen in FIGS. 2 and 3. The elongated windows 55 of each pair of plates are axially aligned to receive a spring divider or separator 61. As more clearly shown in FIG. 8, the divider is formed of sheet metal bent into an elongated pin which is generally triangular in cross section. The pin has a curved base 62 and generally converging sides 63, the opposite ends of the sides being cut away at 64 to form a projection 65 from the base and adjacent portions of the arms. Each projection 65 of the pin is received in one of the pairs of axially aligned windows 55 with the base 62 located against the edge of the indentation 56 and the lower edge of the cut away portions 64 abutting the interior surface of the adjacent plate.
Two groups of spring sets 66, 67, 68 are positioned in the damper to engage the arms or sides 63, 63 of each divider 61, with spring sets 66 and 68 also abutting the diverging edges 35 of the hub arms 32, 39. The elongated openings or windows 55 allow limited movement of the dividers 61 as seen in FIG. 4, to compensate for any differences in spring set lengths. Thus, the dividers can relocate within the allowed movement to prevent uneven loading during operation. As shown in FIG. 4, each divider 61 has a limited length of movement in the window indicated at "X".
In operation, torque applied to the piston plate 11 due to engagement of the friction surface 12 with the interior surface of a torque converter housing causes rotation of the piston plate and drive tangs 17. The drive tangs move counterclockwise, as seen in FIG. 1, in the slots 44 relative to the hub arms 32, 39 to compress the springs 66; the curved edges 57, 57 of the equalizer plates allowing movement of the tangs into the space formed therebetween. Compression of springs 66 will cause the dividers 61 in equalizer 45 to move toward the far edge of the windows 55 away from springs 66, as seen in FIGS. 1 and 3, and causing rotation of the equalizer 45 to compress springs 67. Compression of the central springs cause movement of the spring dividers 61 in the equalizer 46 to the far edge of windows 55 therein away from springs 67 to cause rotation of the equalizer 46. Movement of this equalizer and associated dividers compresses the springs 67 to urge the arms 32, 39 of the hub assembly 22 to rotate, thus rotating the transmission input shaft. The curved edges 57 of the equalizer 46 form a space or slot to receive the hub arms 32, 39 therein upon rotation of the equalizer relative to the hub assembly.
FIGS. 9 through 11 disclose a second vibration damper assembly 71 wherein parts identical to those of FIGS. 1-8 have the same reference numeral with a script a. This assembly includes a piston plate 11a having drive tangs 17a secured thereto by rivets 16a, a hub assembly 22a including hub arms with circumferentially extending slots receiving the drive tangs and a single floating equalizer 72 journalled on the hub assembly. The equalizer comprises a pair of substantially identical plates 73, 73 forming the spring housing; the rear plate 73 being shown in FIGS. 9-11. This plate includes a flat annular body portion 74 having a central opening 75 journalled on the hub assembly 22a and a slightly outwardly and then inwardly curved portion 76 terminating in a pair of diametrically opposed curved arms 77 with radial flanges 78 having spaced openings 79 for rivets 81.
Located within the curved portion 76 are two pairs of elongated openings or windows 82; each pair of windows being diametrically opposed and positioned within the arc of the arms 77. Both the front and rear plates have the windows 82, which are axially aligned in the plates to receive the ends or projections 65a of a spring divider or separator 61a or 61a'. Each window allows an arc of movement of the divider between positions A and B as shown in FIG. 11. Thus, not only does the equalizer 72 float on the hub assembly 22a, but also movement of the spring dividers 61a, 61a' assists in the damping action.
When torque is applied through the piston plate 11a to the drive tangs 17a, rotation of the drive tangs in a counterclockwise direction, as seen in FIG. 9, compresses the damper springs 66a and urges the spring dividers 61a to move in the windows 82 from position A to position B to compress the springs 67a; with the springs 67a urging the second spring dividers 61a' against the edge of their associated windows to rotate the equalizer 72. Movement of dividers 61a' acts to compress the third set of springs which urges the hub assembly 22a to rotate and drive the output member. The damper will operate in the opposite direction under coast conditions for a vehicle.
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A vibration damper assembly used in a torsional coupling between driving and driven members providing a low rate, high amplitude deflection, wherein the damper assembly includes a hub operatively connected to a driven shaft and having arms, at least one floating equalizer journalled on the hub, drive tangs connected to a driving member, and two or more groups of damper springs interposed between the drive tangs, hub arms and floating equalizers. To separate the damper springs in an equalizer, a spring separator or divider is mounted for limited arcuate movement in opposed arms of the equalizers.
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TECHNICAL FIELD
[0001] The invention relates to underground pipe bursting and replacement systems of the static type which operate by pushing or pulling a string of rods to which a bursting head or other tooling is attached.
BACKGROUND OF THE INVENTION
[0002] Pipe bursting is a well known process that brings enormous potential for the efficient and unobtrusive replacement of buried pipelines. Currently the there are two widely used but separate systems used to accomplish pipe bursting. The choice of the system is most often dependent on the type of utility being upgraded.
[0003] Gravity sanitary sewer systems are made up of interconnected pipes buried at depths from (4) to (40) foot beneath the surface. These systems make use of ‘manholes’ to provide access for maintenance and cleaning of the interiors of the pipes. It is advantageous to minimize the damage and potential need for replacement of these manholes during the bursting operation. To do that requires practicing the method described in U.S. Pat. No. 6,299,382. That method calls for use of a pneumatic actuated tool, hydraulic winch with the guide cable passed through the existing pipe, and a front-mounted bursting head. Hence, primarily for that reason, most gravity sewer pipe bursting is done with pneumatic tools.
[0004] Potable water pipes are also widely in need of replacement. These systems, by the nature of the fact that they are pressure fed and therefore independent of the effects of gravity, tend to be buried at shallow depths in moderate climates. In addition, they do not have manholes, unlike the gravity sewer systems. For these reasons, water pipes are typically burst with a machine that requires an access pit at each end of the job. In the situation where there is no manhole present, having two access pits is not necessarily disadvantageous. The machine that fits this description is called a static system. Using significant hydraulically actuated force applied through a rod string, the tooling used on a static system splits the existing pipe and expands the surrounding soil. This style of bursting has four major components:
[0005] A. Tooling. This subsystem performs the function of cracking the pipe, expanding the adjacent soil with a conical form and a lastly provides a means of attachment of the product pipe to the rear of the tooling.
[0006] B. Rod String. The rods, threaded at each end, are engaged end to end into a string. This string transmits the pull force between the hydraulic pulling unit and the tooling.
[0007] C. Hydraulic power pack. This subsystem exists purely to provide pressurized hydraulic flow for operation of the pulling unit. The power pack may even be a hydraulic excavator configured to power auxiliary equipment as needed.
[0008] D. Downhole Unit. This is generally the most complex part of the machine; it entails the greatest amount of mechanism and complication of any of the four components. Hydraulic cylinders are employed to cyclically stroke a rod engagement system. The rod engagement may be through the threaded end, or by a mechanism that grips the rod outer surface or engages features on the outer surface. The engagement system must grip or engage the rod and apply thrust force in one direction, while sliding freely along the length of the rod in the opposite direction. This system must have the capability of being shifted relative to direction of operation so that rods may be added to, or removed from the string. An optional subsystem in downhole unit is a device to aid in the threading and unthreading of rods.
[0009] Two known pit launch static bursting machines are known commercially as the McLaughlin pit launch and the Vermeer PL8000. These are low force (10,0000 lb) pulling machines having a hole approximately 8″ in diameter in the front of the machine to accept small backreamers into the machine. When this is done, the vise floats (moves) with the spindle to allow the tooling to enter the machine. Since the pulling force was low, the hole did not present major problems with respect to soil entry or shoring area. With higher pulling forces, providing a hole in the front shore plate of the machine becomes problematic because soil will tend to enter the machine through the hole.
SUMMARY OF THE INVENTION
[0010] The present invention relates to an improved static bursting system. According to one aspect of the invention, the system provides for plain bearing pullback without rotation, while allowing rotation during payout. Rod string rotation must be a feature of this design available during rod payout. In many applications where an existing line has collapsed, the rod string or winch rope cannot be passed through the collapsed section successfully. A system that rotates the drill string makes it possible to guide the unit through the collapse as rod is added using either a non-directional drill bit or a drill head as typically used in horizontal directional drilling (HDD).
[0011] While working through this collapsed section, modest axial thrust in the range of 1000 to 40,000 lb may be applied to the bit through the drill string during rotation. This allows the bit to displace material with the option of delivering drill fluid through the hollow drill string to float the soil out of the existing pipe. The thrust must be applied to the drill string through a bearing. Roller bearings of this capacity are moderately but not excessively large and costly.
[0012] Pullback is the process wherein rod is removed from the drill string, shortening the string. The tooling is progressively pulled through the existing pipe, cracking the pipe and expanding the local soil. During the process, the rod string is not rotated. Forces applied to the drill string are in the range of 60,000 to 250,000 lb, significantly greater than during rod payout. Bearings of this capacity are very large and costly. To avoid the encumbrance of these bearings, according to the invention, a plain load bearing flange is used instead. This bearing will not support rotation during pullback and will in fact cause the rotation motor to stall should rotation be attempted when high axial pullback forces are applied. To achieve a successful design in this style, the shaft should be free to float a short distance between being loaded on the payout direction against the roller bearing and being thrust against the plain bearing load flange in the pullback direction. This float may be small in magnitude, e.g. between 0.05 and 0.25 inch.
[0013] It is advantageous but not necessary to preload the shaft against the roller bearing when no load is applied to the rod string. This preload can be modest, in the 500 to 2000 lb range. It is best achieved with a preloaded spring, the spring is depressed a short percentage of its design travel in the installed condition. This preload does not change as axial thrust in the payout direction is applied. As axial thrust in the pullback direction is applied, the modest spring force is overcome and the spring compresses further. This allows axial movement of the shaft relative to the bearings. As the shaft moves through the short distance per the design, it soon contacts the plain bearing load flange.
[0014] According to the invention, the drill string is allowed to rotate during payout to drill through obstructions within a collapsed pipe. During pullback, the unit is unable to rotate the rod string, therefore rendering tooling such as back reamers that function with rotation unusable. Pullback tooling is therefore limited to conical expanders, blades and other devices that perform hole and pipe expansion via axial movement only.
[0015] The invention further provides a “bungee vise” that aids in extending or retracting the drill string. During both the payout and pullback phases of a bursting job, the movement of the rod is stopped momentarily to add or remove the last rod of the string. During this moment, there are residual forces applying an elastic load to the rod string. During payout, that elastic load may be due to an arced path that the existing pipeline follows, or it might be due to an obstruction encountered at the front of the rod. Because the rod string is small in diameter compared to the existing host pipe, any load will cause an imperceptible buckling that will disappear should the load be released. The buckling uses up a small percentage of the length of the rod string, as little as nothing or as great as 12 inches. Unloading of the rod during the period when the rod is stopped would cause the rod to thrust back this distance, resulting in location issues for rod thread up and causing wasted travel every time the process is repeated.
[0016] During pullback, the process is similar but opposite. The elastic load applied to the tooling by the product pipe will produce residual load even when the rod string has been halted and work done by the tooling has halted. If the rod is not secured while the last rod is being removed, then the string will be pulled by the elastic pipe forces back into the bore. This distance can be anywhere from nothing to 3 feet depending on the soil conditions.
[0017] In order to overcome these potential problems with residual load, a vise of the invention is configured to grip the rod string and provide frictional force due to high hydraulically induced clamping forces. In addition to the frictional force, should the residual loads be exceptionally high, the gripping jaws are configured to encounter a shoulder on the rod after a brief amount of axial slippage. This slippage is best kept to a minimum, preferably in the range of 0.10 to 0.25 inch, in order to limit damage to the gripped surfaces on the rod and jaw.
[0018] The vise is called on to do another task, that of restraining the rod string from rotating while the last rod is being rotated with significant torque to either add it to or remove it from the drill string. While the threading operation is in process, the vise holds the residual axial load of the string while simultaneously preventing the string from rotating as torque is applied to add or remove another rod.
[0019] A further aspect of the invention relates to the thrust cylinders. In a static bursting system, the rod thrust or pullback is normally applied to the rod string via actuation of hydraulic cylinders. Normally, hydraulic cylinders are designed in a manner where flexible hydraulic hoses are plumbed to the cylinder body through ports in the cylinder wall. Pressurized hydraulic fluid is fed to the cylinders through these ports and the cylinder rod is extended or retracted relative to the cylinder body as a function of which port the fluid is supplied to.
[0020] In the commonplace configuration just described, most mobile hydraulic equipment is assembled with the cylinder body fixed or pinned to the frame of the machine. Further, the rod, not the cylinder body, is permitted to extend or retract relative to that same frame. This works well in most cases as the flexible hoses do not have to move any appreciable distance during movement of the rod. Should the rod end be pinned to the frame and the cylinder end with hoses attached be allowed to move, this would not be the case.
[0021] Moving hoses are prone to abrasive wear, leaking and pinching in machine features. Also, the slack in the hoses that must be accommodated in the retracted condition would make them prone to being snagged on other machine components and possibly torn out of the ports at either end. In the case of the machine used as an example herein, the travel of the cylinders is 46.5″ from fully retracted to fully extended. In this case, successfully accommodating moving hoses over that length would prove difficult.
[0022] Conventional cylinders as described above with a rod extending through one end of the cylinder have forces that are not equal in the extension and retraction directions. The area of the cylinder bore is always greater than the area of the cylinder bore less the cross sectional area of the rod. This is well understood in hydraulic cylinder application and allows the design of the cylinder to be tailored with variation in rod size should the retraction direction not be the primary work direction. A larger rod diameter causes the rod side of the cylinder to have a small area and therefore permits rapid retraction for a given hydraulic pump flow rate. A bursting machine using the concepts disclosed herein uses the more powerful extension direction to pull rod back, and the less powerful direction to thrust rod in the payout direction. The cylinders each have a rod that is large in comparison to the cylinder size, thus there is no compromise on performance of the machine due to either using cylinders in the ‘wrong’ direction, or using cylinders available through an industrial catalog that would have a small rod diameter.
[0023] Conventional static bursting machines are configured with the cylinder body stationary and the rod attached to the moving carriage. This carriage serves to grip or propel the rod string in the direction chosen by the operator. According to the invention, the cylinders are configured with the cylinder body attached to the carriage and the rod anchored at the front of the machine where they are loaded against the shoring plate. While the rod size in these cylinders is large in comparison to the cylinder body, it is still smaller than the cylinder body. By reversing the normal orientation, the tooling at the end of the rod string may be pulled into the machine and ‘docked’ between the cylinder rods. This would still be possible in the conventional orientation that has been described, however it should be understood that the machine would require greater overall width. This increased width has the potential to encumber operation and will require additional weight, added pit excavation, and greater difficulty in machine placement should there be other utilities located adjacent to the host pipe being burst.
[0024] The combination of the relatively large rod diameter coupled with the desire not to feed the hydraulic cylinders through flexible hoses that move with the bodies creates an opportunity to feed the cylinders through drilled longitudinal passages in the rod. The hydraulic hoses are attached to the rod at the rod end which is anchored to the frame or shore plate. These dual passages are drilled the length of the rod to provide both ingress and egress of the hydraulic fluid to the cylinder cavities. These passages eliminate any need for the hoses to move with the carriage.
[0025] Another option according to this aspect the invention that is used in the example below works with the reverse cylinder configuration to narrow the machine further. Offsetting the cylinders such that the cylinders are positioned diagonally relative to the frame of the machine, above and below the spindle shaft will orient the rods so that docked tooling may be removed from between the rods while still allowing the operator to stand close to the center line of the machine. This position close to the center line becomes important when the operator is loading or removing rods manually into/from the docking area along the centerline.
[0026] The invention further provides a collapsing rod cradle made to support and align a rod when it is added to or removed from the rod string. The design of this support or cradle becomes complicated when applied to a bursting machine such as that described previously and further having a spindle that applies the pulling or thrusting force via direct threaded attachment to the rod string. The rods are added or removed in a zone that is between the vise and the spindle frame face. Further, during this operation it is necessary for the front end of the rod to reside in the vise, the back half of the rod must sit in a cradle that is in the vicinity of the spindle face. During the cycle of traversing the spindle from right to left, the zone where the rod was added is now ‘compressed’ until the spindle frame nearly touches the vise.
[0027] While this right to left spindle frame movement is intended to move the rod string, it also results in the spindle frame occupying the volume where the rod cradle was performing its function of supporting the rod. Once the rod is tied into the rod string by making up the thread between the last and next to last rods, as well as between the last rod and the spindle, the cradle is no longer needed. It would be possible to use a cradle mechanism that collapses into the area below the spindle frame as the frame moves from right to left, and reset into position as the frame moved left to right. Such a design has been used in the past on machines such as the Vermeer PL8000 directional boring machine. In this case, spoil or contamination bound to enter into the machine and fall into the hull would impair the free movement of the device.
[0028] For the aforementioned reason, the cradle of the invention is preferably designed in not only a telescoping manner, but is also engineered to follow a path during retraction that would cause it to move away from the rod as it is retracted. This distance gained between the cradle and the rod helps prevent the rod upset from hanging up on the cradle as the relative axial movement occurs. Any entanglement between the cradle and rod could result in a damaged cradle mechanism.
[0029] In contrast to the known static pulling machines mentioned above, the machine of the invention uses a front shore plate with a slotted opening to provide good shoring area and limit soil entry into the machine. The shore plate is removed prior to entry of the tooling into the machine through a relatively large (15.5″ diameter) front hole. This is a unique feature when the floating vise is combined with a removable shore plate. These and other aspects of the invention are further described in the detailed description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] In the accompanying drawings, where like numerals denote like elements:
[0031] FIG. 1 is a perspective view of a rod pushing and pulling machine according to the invention;
[0032] FIG. 2 is a perspective view of an auxiliary shore plate used with the machine of FIG. 1 ;
[0033] FIG. 3 is a perspective view of the spindle assembly, jaw assembly and cylinders of the machine of FIG. 1 , with the cylinders extended and the jaw assembly in its front position;
[0034] FIG. 4 is the same view as FIG. 3 , with the cylinders retracted;
[0035] FIG. 5 is the same view as FIG. 3 , with the cylinders extended and the jaw assembly in its rear position (the “final docking” position);
[0036] FIG. 6 is a perspective view of the jaw assembly of the preceding figures;
[0037] FIG. 7 is a top view of the jaw assembly of FIG. 6 ;
[0038] FIG. 8 is a side view of the jaw assembly of FIG. 6 ;
[0039] FIG. 9 is a front view of the jaw assembly of FIG. 6 ;
[0040] FIG. 10 is a top view of the spindle assembly of the preceding figures with cradle extended;
[0041] FIG. 11 is a top view of the spindle assembly of the preceding figures with cradle retracted;
[0042] FIG. 12 is a side view, in section, taken along the line 12 - 12 in FIG. 10 ;
[0043] FIG. 13 is the same view as FIG. 12 , showing the cradle in its retracted position (line 13 - 13 in FIG. 11 );
[0044] FIG. 14 is a sectional view taken along the line 14 - 14 in FIG. 10 ;
[0045] FIG. 15 is a top view of a thrust cylinder of FIG. 1 , in an extended position;
[0046] FIG. 16 is a side view of the thrust cylinder of FIG. 15 ;
[0047] FIG. 17 is a sectional view taken along the line 17 - 17 in FIG. 16 ;
[0048] FIG. 18 a top view of the rod shown in FIGS. 15-17 ;
[0049] FIG. 19 is an enlarged sectional view of the seal carrier shown in FIG. 17 ;
[0050] FIG. 20 is an enlarged sectional view of rod seal shown in FIG. 17 ;
[0051] FIG. 21 is enlarged side view of the piston and seals of FIG. 18 ;
[0052] FIG. 22 is an exploded view of the cradle assembly of the machine of FIG. 1 ;
[0053] FIG. 23 is a side view of a rod section used in the invention;
[0054] FIG. 24 is a lengthwise sectional view of the rod shown in FIG. 23 ; and
[0055] FIGS. 25 and 26 are side and end views, respectively of the load flange of FIG. 14 .
DETAILED DESCRIPTION
[0056] FIG. 1 shows a downhole machine 10 of a pipe bursting machine of the invention. A spindle frame 12 is shown with its sheet metal cover in place. Spindle frame 12 traverses right-to-left a distance equal to 40% of the overall length of the entire machine. The spindle shaft l 15 of spindle frame 12 is connected to a rod string 11 by a threaded joint in the end of a spindle shaft extension 20 which is made as a separate part for ease of replaceability.
[0057] Force to perform the pipe bursting operation is applied to spindle frame 12 via a pair of hydraulic cylinders 26 . A cylinder rod 14 of each cylinder 26 is attached to a front shore plate 25 . Shore plate 25 is placed against the access pit wall and the face of the existing or host pipe. A rod box 31 stores rods to add to or remove from rod string 11 . When rod box 31 is full, tabs 47 are rotated upwards and a lifting hook is engaged. Box 31 is then replaced with a box full of rods or an empty box, as the situation demands. Box 31 sits on a tray 46 . Tray 46 holds box 31 in position to facilitate easy manual rod placement into or away from a rod cradle 17 . A front access door 48 is removed to extract or replace rods. Tray 46 is removable for transport. When tray 46 is removed, the mate to eye 49 is exposed. This pair of eyes 49 facilitate lifting the entire lower unit 10 into or out of the access pit.
[0058] Tie down loops 35 are used in transport to secure the lower unit 10 to a truck bed or trailer. A storage box 53 holds the operator's manual. A cover 27 protects a large pilot-controlled hydraulic valve (not shown). This valve facilitates the high hydraulic flows required to actuate the main thrust cylinders 26 . The pilot flows that control the valve are metered at a control station 37 by the machine operator. Direction and flow rate of the main thrust cylinders 26 , as well as spindle motor direction, are controlled at station 37 .
[0059] Four height adjustment legs 34 are provided at the four corners of the machine 10 . A hydraulic cylinder 41 of each leg 34 is secured to an outer frame 33 of leg 34 . Frame 33 is bolted to main hull 23 which contains the majority of the working components of the lower unit 10 . Extension of cylinder 41 moves inner leg 45 down, forcing foot 39 against the pit bottom. Foot 39 is free to pivot about a pin 43 . Similar height adjustment legs 34 are located at all four corners of the machine 10 . The cylinders 41 are actuated by the operator at hydraulic control station 29 .
[0060] At the front of the unit, shore plate 25 has notches 55 on its upper edge for mounting an auxiliary shore plate 19 thereon ( FIG. 2 ). Auxiliary shore plate 19 doubles up over shore plate 25 with its main face forward. A downwardly opening slot 21 allows the rod string to pass through plate 19 as well as allowing the auxiliary shore plate 19 to be lifted off rod string 11 when nearing completion of the bursting job. This removal becomes necessary so that the tooling may be drawn through the large center hole 28 in shore plate 25 surrounding the rod string 11 . Tabs 24 , located on both sides of plate 19 , fit into notches 55 to assure alignment and proper height of slot 21 . A series of slots 22 near the upper edge of plate 19 allow it to be lowered into or raised out of the pit.
[0061] FIG. 3 is an isometric view from the same vantage as FIG. 1 , however it differs in that all external components of machine 10 have been removed. Spindle assembly 12 is supported vertically by track rollers 17 . Two track rollers 17 are visible; they in fact exist at all four corners of the assembly 12 . Track rollers 12 may be those available from Torrington Manufacturing, effectively small steel wheels with an internal needle roller bearing. In this view, cylinder body 16 is visible throughout its length. Rod cradle 18 is shown fully extended with a crotch 30 aligned with shaft extension 20 . Cylinder rod 14 is also fully extended, making the area for rod placement and removal of rods between shaft extension 20 and rod string 11 easy to see.
[0062] A vise assembly 15 is shown with rod string 11 clamped in one of two jaw sets 72 , 73 . Serrations 51 on jaws 72 , 73 can clamp on an added rod to apply torque. Vise 15 is further guided and restrained by cylinder rods 14 which pass through cylindrical sleeves 63 forming ends of the frame 36 supporting vise 15 for movement along cylinder rods 14 . Shoulders 13 at the front ends of cylinder rods 14 are mounted to and react in thrust against shore plate 25 . Hydraulic ports 57 and 61 on each rod 14 are used to connect flexible hydraulic supply hoses to feed the thrust cylinders 26 made up of rod 14 and cylinder body 16 . Hydraulic control valve 59 sequences the operation of the jaws in vise 15 .
[0063] FIG. 4 is the same set of components as FIG. 3 , however rods 14 have been fully retracted into cylinder bodies 16 . With shoulders 13 attached to shore plate 25 (such as by bolts) and the shore plate 25 further bolted to hull 23 , the result of retracting rod 14 is actually to move cylinder bodies 16 and attached spindle assembly 12 closer to shore plate 25 . In this position, vise 15 is very close to spindle assembly 12 , leaving no room for rod cradle 18 . Rod cradle 18 , partially visible behind vise 15 , has retracted into spindle assembly 12 with its supporting arms 101 inside spindle assembly 12 and crosspiece 102 against the spindle frame 12 . Rod string 11 is now in position to be threaded to spindle extension 20 . This is accomplished by clamping the forward set of jaws 72 in vise 15 against rod string 11 (operation shown completed) and rotating the spindle extension 20 in the appropriate direction.
[0064] Referring to FIG. 5 , rod 14 is then fully extended from cylinder body 16 . Vise 15 is pulled along with spindle assembly 12 from its normal working position. This is accomplished by engaging jaw set 72 against rod string 11 and extending rod 14 to move the entire assembly of assembly 12 and vise 15 to the right. This position is desirable when tooling must be pulled into hull 23 for final docking as explained hereafter. Vise 15 is more completely visible in FIG. 6 . Sleeves 63 are hollow, permitting them to be centered on rods 14 . This provides torque reaction when the rod string is tightened, as well as permitting sliding along rods 14 when room must be made for docking of the tooling as per FIG. 5 .
[0065] Front faces 67 of vise frame 36 are configured to rest against the back of shore plate 25 . In doing so, they react against residual elastic pipe forces that may be present. Idler rollers 69 set on spaced vertical axles 70 keep rod string 11 centered relative to the vise and therefore to the rest of the machine. Rollers 69 are engineered so that shoulders on the rod will pass freely through them. A pair of cylinders 71 actuate clamping of jaws 72 and 73 . Another cylinder 65 , while the same size as cylinder 71 , is positioned to rotate jaws 73 about the axis of rod string 11 . This is done when jaws 73 are clamped and serrated surfaces 51 of jaws 73 grip the rod securely. Cylinder 65 breaks loose the threaded joint between rod string 11 and the endmost rod, allowing the endmost rod to be removed from the string. To loosen the threaded joint between rod string 11 and the endmost joint, jaws 73 turn approximately 30°, in any case less than 360°. This feature is only used to loosen threaded rod joints, never to tighten, because jaws 73 create very high torque relative to the spindle rotation drive motor.
[0066] FIG. 7 shows all of the jaws 72 and 73 from above. In this figure, jaws 72 are clamped on the available rod, while jaws 73 are open. In FIG. 8 , a greater portion of cylinder 65 is exposed. In FIG. 9 , idler rollers 69 are fully visible in profile, shown guiding and centering rod string 11 . This view demonstrates how cylinder 71 is positioned to provide clamp load on rod string 11 .
[0067] In FIG. 10 , rod cradle 18 is shown fully extended. The four track rollers 17 are mounted at respective corners of a rectangular spindle frame 140 , and a grease zerk manifold 139 is exposed through an opening in the top of frame 140 . Frame 140 includes a pair of front and rear walls 141 , 142 having pairs of aligned openings 143 , 144 therein in which cylinder bodies 16 are mounted, as well as internal structural members 146 on which various spindle assembly components are mounted as shown in FIG. 14 . Openings 143 , 144 preferably open laterally so that cylinders 26 can be removably mounted therein. Pairs of generally C-shaped holders 147 , 148 are placed over the outside of cylinder body 16 and bolted to frame 140 to hold cylinders 26 in place. To hold cylinder bodies 16 stationary relative to frame 140 , openings 143 and front holder 147 engage an annular groove 77 on the outside of cylinder body 16 , discussed further in connection with FIGS. 15-17 below.
[0068] As shown in FIG. 12 , an arm 101 is configured to slide freely through a concentrically positioned center hole in bushing 103 . A collar 105 fixed to the outside of arm 101 limits outward travel of cradle 18 by bumping against the inner face of bushing 103 . A piston 107 provides the reaction force needed to hold cradle 18 in the proper position. Piston 107 is secured near the rear end of arm 101 behind collar 105 and slides freely within a tube 113 . Piston 107 is not located concentrically on arm 101 . In this manner, the angle between the axis of arm 101 and the axis of tube 113 will vary as cradle 18 is moved away back and forth through its range of travel, urged to extend by a gas spring 112 which is attached at one end to the inside of tubular arm 101 at the position of collar 105 . Cap 109 seals tube 113 at its rear end, and optional oiler 111 provides drip lubrication to the interior of tube 113 .
[0069] The change in angle causes cradle 18 to fall away from the bottom of the rod as arms 101 of cradle 18 are retracted into their respective tubes 113 . As shown in FIGS. 12 and 13 , piston 107 biases the rear end of arm 101 downwardly relative to the opening through bushing 103 , causing the front end to which cradle 18 is attached to be lifted upwardly. This displacement lessens as the distance between piston 107 and bushing 103 becomes greater, causing cradle 18 to drop downwardly a slight distance as piston reaches the position shown in FIG. 13 . In this position, the angle between the axis of arm 101 and axis of tube 103 is smaller that as shown in FIG. 12 .
[0070] Referring to FIG. 14 , a front end portion of the spindle shaft 115 is mounted in a front plain bearing 119 . Bearing 119 is contained in a bearing housing 121 that is bolted to the front face of spindle assembly 12 . Bearing 119 is designed only for handling radial forces transmitted from shaft 115 . A rear end portion of spindle shaft 115 is supported by a set of tapered roller bearings 127 located in a housing 123 that is also bolted to spindle assembly 12 . Tapered roller bearings 127 support shaft 115 in both thrust and pullback directions. However, bearings 127 are sized only to handle the magnitude of thrust developed by the machine in payout, in this example about 40,000 lb. During pullback, the capacity of bearings 127 would be greatly exceeded by the 250,000 lb. of pullback force that can be produced by the main thrust cylinders 26 . For this reason, the system has been designed to allow the shaft 115 to float, unloading the tapered roller bearings 127 in the pullback direction.
[0071] Spring can 131 is loaded against taper roller bearings 127 by a coil spring 129 for small magnitudes of pullback, such as breaking or unthreading the rod joint. When the load increases above a threshold level such as 1000 lb, the spring 131 has compressed far enough that a flange 117 mounted on shaft 115 at an intermediate position along its length contacts the face of a load flange 125 . As shown in FIGS. 25 and 26 , load flange 125 is preferably in the form of a wedge with its wide end bolted to and braced against frame 140 . The narrow end of load flange 125 has a cylindrical cutaway 126 to provide clearance for the spindle shaft 115 , and a counterbore the bottom of which forms a load bearing surface 128 . When flange 117 is in substantial contact with surface 128 of flange 125 , shaft 115 will not rotate due to the high friction induced. This is desired in that the machine is intended for static pipe bursting or other non-rotating pullback operations. Use of the plain bearing 119 and load flange 125 with flange 117 avoids the size and expense of a tapered roller bearing capable of handling 250,000 lb.
[0072] A sprocket 133 is torsionally keyed to shaft 115 . A roller chain (not shown) drives sprocket 133 under the operator's control to thread or unthread rods or turn small diameter tooling during payout. A water swivel 137 allows drilling fluids to pass to the hollow drill stem while being fed by a non-rotating hose. Locknuts 135 are used to secure sprocket 133 to shaft 115 in the axial direction.
[0073] FIGS. 15-21 show the structure of cylinders 26 in detail. Hydraulic port 57 at the distal end of rod 14 communicates with a flow passage 97 inside rod 14 which opens onto the piston side of rod 14 . Connecting the hydraulic fluid pressure source to port 57 while connecting port 61 to tank fills cylinder body 16 with fluid and extends rod 14 . Port 61 communicates with another lengthwise flow passage 99 which extends almost to the rear end of rod 14 . Passage 99 communicates with an outwardly opening annular groove 94 through a radial port 87 . Fluid in groove 94 enters the space on the rod side of a piston 90 mounted at the rear end of rod 14 through a series of cutaways 89 in piston 90 , retracting rod 14 when port 57 is connected to tank.
[0074] Piston 90 is mounted on the end of rod 14 by a steel lock ring 95 . A split nylon wear ring 93 mounted in an annular groove on the outside of piston 90 slides along the inside of cylinder 16 . Leakage between piston side and rod side is prevented by a urethane umbrella-type seal 96 mounted in another groove frontwardly from wear ring 93 . A seal carrier or cap 75 is secured by threads 83 to the front end of cylinder body 16 . Cap is supported on rod 14 by a nylon split bearing ring 81 and leakage is prevented by a series of nylon seals 82 . As discussed above, rod 14 has a large diameter relative to cylinder body 16 , making the annular space 88 on the rod side thin, so that only a small flow of fluid is required retract the cylinder in FIGS. 15-17 . For this purpose, the cross section area of annular space 88 is from about 10% to 60% of the cross sectional area of the cylinder cavity. (This equates to a ratio of working surface area of from 10:1 to 1.67:1.) If annular space 88 is excessively thin (<10% of the cross sectional area of the cylinder cavity), retraction of the cylinder will not be powerful enough. On the other hand, when it is too wide (exceeds 60% of the cross sectional area of the cylinder cavity) the cylinder begins to behave like a conventional hydraulic cylinder.
[0075] FIGS. 23 and 24 show a preferred form of drill rod 100 of the type used to make rod string 11 . Multiple rods 100 are joined together end-to-end to create a string 11 as long as 500 feet or more. Male thread 116 mates into the next rod's female thread 122 . An undercut 118 is provided for jaws 72 to grip. Should the axial load be high, the rod 100 may slip until a shoulder 119 contacts jaw 72 . Jaws 73 engage the outer surface of each rod 100 outside of female thread 122 . An axial bore 124 of rod 100 is optionally used conduct fluid from the downhole machine to the front of the rod string. Bore 124 also reduce the weight of rods 100 to facilitate manual handling.
[0076] Operation of downhole machine 10 according to the invention is as follows. A typical job will involve pushing a rod string out through an existing pipeline from the exit pit (where machine 10 is) to the entry opening in the pipeline, such as in a trench or manhole. To extend a rod string 11 , the machine 10 starts in the position shown in FIG. 3 , but with no rod string 11 present. A rod 100 is removed from box 31 and placed in cradle 18 at crotch 30 with the male threaded end 116 facing shaft extension 20 , which has a female thread ( FIG. 14 ). The female end 122 is placed in rear jaws 73 , and jaws 73 are closed on it. The spindle assembly 12 is then operated to thread shaft extension 20 over male end 116 . Once this is done, jaws 73 are opened and spindle assembly 20 is moved to the left by retraction of cylinders 26 to assume the position shown in FIG. 4 . Jaws 72 are then operated to grip rod 100 at undercut 118 . The spindle shaft 115 and extension 20 are then rotated in reverse to unthread extension 20 from male end 116 . Cylinders 26 are then extended to move spindle assembly 12 to the right to assume the position shown in FIG. 3 , and the machine 10 is ready to accept another rod 100 .
[0077] The procedure for adding the second and subsequent rods 100 is the same as described above, except that jaws 73 are not closed on the female end 122 of the new rod 100 , and the male end 116 of the previous rod is positioned between jaws 73 as shown in FIG. 3 . Instead, the female end of rod 122 is brought over male end 116 of the previous rod held in jaws 72 . When spindle assembly 12 is then operated to thread shaft extension 20 over male end 116 of the new rod, female end 122 of the new rod is threaded onto male end 116 of the previous rod at the same time. In the process of retracting the cylinders 26 to assume the position of FIG. 4 , the entire rod string 11 is pushed forward. This process is repeated until the leading end of string 11 emerges from the entry opening.
[0078] Once the push out operation is complete, a bursting head or other tooling is mounted on the distal end of rod string 11 in preparation for pullback through the existing hole or pipeline. Such a bursting head preferably also pulls in a replacement pipe at the same time in a manner well known in the art.
[0079] Pullback starts with vise 72 closed on neck or undercut 118 as shown in FIG. 4 . Jaws 72 are opened, and cylinders 26 are extended to move spindle assembly 12 to the right, pulling the rod string 11 and bursting head with it. Once spindle assembly 12 has reached the position shown in FIG. 3 , jaws 72 are closed on the neck 118 of the second to last rod 100 , and jaws 73 are actuated by an automatic cycle that clamps female end 122 of the last rod 100 and rotates it a sufficient distance under the action of cylinder 65 to loosen the threaded joint; one-eighth to one-quarter turn is generally enough for this purpose. Jaws 73 are then opened and returned to their non-rotated position. Spindle shaft 115 is then rotated to unthread the last rod 100 the rest of the way from the second to last rod, with spindle assembly 12 moving about an inch to the right during this process. Jaws 73 are then closed again on last rod 100 , and spindle assembly 20 is operated to unthread last rod 100 from shaft extension 20 . When this is done, jaws 73 are opened, and the last rod 100 may be manually removed and placed in storage box 31 . Rods 100 are sized to be lifted and handled by one person; in this embodiment, rods 100 weigh 52 pounds each.
[0080] The pullback steps are then repeated as required until the first rod 100 , having the bursting head attached thereto, is encountered. At this time, outer shore plate 19 is removed by attaching chains with hooks to openings 22 , exposing center hole 28 . Last rod 100 is then removed in a normal manner, resulting in a leading end portion 91 of bursting head 92 held in jaws 72 . Shaft extension 20 is then threaded onto bursting head 92 , and jaws 72 remain closed. Cylinders 26 are then extended, pulling back bursting head 92 through hole 28 into the position shown in FIG. 5 . Vise assembly 15 travels back as well because it is locked to bursting head 92 by jaws 72 . Bursting head 92 is then unthreaded from shaft extension 20 and jaws 72 are opened, allowing bursting head 92 to be lifted out of the pit.
[0081] In the foregoing manner, the machine 10 of the invention can be used for pipe bursting and replacement. During the pushing out step, it may often be desirable to mount a drill bit on the leading end of the drill string in order drill a pilot bore through the ground, if there is no existing pipeline to follow. The drill bit may of the type having an angled steering face and can be steered with machine 12 using the well known push-to-steer, push-and-spin to bore straight ahead method. The drill bit might also be needed to drill through collapsed or block portions of an existing pipeline to be replaced. The machine of these invention is capable of performing these functions as well as pull back under much higher loads, without need for expensive high capacity roller bearings.
[0082] While certain embodiments of the invention have been illustrated for the purposes of this disclosure, numerous changes in the method and apparatus of the invention presented herein may be made by those skilled in the art, such changes being embodied within the scope and spirit of the present invention as defined in the appended claims. For example, while the invention has been discussed as a static bursting system, it is also possible to use a bursting or pipe splitting head capable of deliver cyclic impacts to the pipeline being burst.
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A rod pushing and pulling machine includes at least one hydraulic cylinder having a front end thereof engagable with a reaction surface at an entry opening of a existing pipeline or borehole, a spindle assembly, and a dual vise assembly. The spindle assembly includes a frame, a spindle shaft rotatably mounted in the frame, a distal end of the spindle shaft being threaded for engagement with a mating thread of a rod, a drive system for rotating the spindle shaft in threading and unthreading directions, the spindle frame being secured to a rear end of the hydraulic cylinder for pushing or pulling of a rod string engaged to the spindle shaft upon extension or retraction of the hydraulic cylinder, and a support assembly for the spindle shaft. The support assembly includes a set of roller bearings rotatably supporting the spindle shaft, a radial flange on the spindle shaft, and a load flange secured to the spindle frame positioned to engage the radial flange, whereby the radial flange comes into engagement with the load flange during pulling operation to prevent rotation of the spindle shaft during pulling operation, and leaves engagement with the load flange during pushing operation so that the spindle shaft may rotate during pushing operation supported by the roller bearings. The dual vise assembly has two pairs of separately actuable jaws positioned to grip a rod nearest the spindle shaft and a rod adjacent the rod nearest the spindle shaft.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] n/a
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] n/a
NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] n/a
REFERENCE TO A SEQUENCE LISTING
[0004] n/a
BACKGROUND
[0005] 1. Field of the Invention
[0006] The present invention relates to bulk vending machines that sell items, such as capsule toys, and in particular to bulk vending machines that sell items in combination with a redemption certificate for points that can be redeemed at a website for premium prizes by a customer, and for collection of marketing information by the seller.
[0007] 2. Description of the Prior Art
[0008] Recent Product manufacturers and retailers have always been interested in finding new ways to better attract and hold customers. One method commonly used, particularly by national brands, is to sponsor some form of sweepstakes event to differentiate themselves from a competitor and help build brand awareness. In addition to sweepstakes type attractions, others have tried to integrate gaming concepts into the retail environment to help attract customers.
[0009] The psychological attraction to the dream of winning prizes in a contest is strong and can be used to encourage compliance with marketing surveys.
[0010] Some have incorporated a game of chance into the retail environment prior to the check stand. A method of randomly determining the value of a coupon presented to a coupon validator machine by a shopper prior to proceeding to the checkout counter is disclosed in U.S. Pat. No. 5,368,129 granted Nov. 29, 1994 to Van Kohom. The coupon validator prints the randomized discount amount on the coupon which is returned to the shopper for use at the checkout counter.
[0011] Others have incorporated a game of chance at the check stand. U.S. Pat. No. 4,854,590 granted Aug. 8, 1989 to Joliff, et al. discloses a microprocessor based system for connection to a cash register and activated upon each ring-up of a valid sale. The system randomly determines if the customer has won, and if so, what amount has been won.
[0012] U.S. Pat. No. 6,634,550 granted Oct. 21, 2003 to Walker, et al. discloses a virtual slot machine display device tied to a point of sale terminal The game presentation includes images of products and indicates what has been won, such as a free product, a discount on a product selected for purchase, a coupon, or an upsell offer.
[0013] U.S. Pat. No. 6,048,268 granted Apr. 11, 2000 to Humble discloses a promotional game operating in conjunction with a point of sale terminal displaying the image of a game card. The game card has areas which appear covered and are exposed by customer selection similar to that of a scratch ticket game. The processor selects prizes and varies the odds of winning a prize as a function of the identity of products purchased by the participant or their dollar value.
[0014] U.S. Pat. No. 4,157,829 granted Jun. 12, 1979 to Goldman, et al. discloses an instant lottery game for a centrally controlled remote vending machine. Upon the receipt of a wager of a proper amount, the central computer generates random indicia to be matched with the patron's pre-selected indicia to determine and pay a cash prize amount. There is no vending of a product, just a lottery game.
[0015] U.S. Pat. No. 4,213,524 granted Jul. 22, 1980 to Miyashita, et al. discloses an automatic vending machine with lottery bonus. A plurality of electric lamps arranged geometrically on a front panel of the machine and a lamp control circuit for lighting the lamps successively and repeatedly in response to a vending signal produces a winning signal for discharging an extra article as a free addition if the light spot is stopped at a predetermined lamp having a lucky number.
[0016] U.S. Pat. Publication No. 20030186732 filed Oct. 2, 2003 by Viglione discloses a vending machine offering a game of chance or skill. A game is played for a predetermined prize only after payment and selection of a product.
[0017] U.S. Pat. Publication No. 20020107610 filed Aug. 8, 2002 by Kaehler, et al. discloses a vending machine randomly dispensing prize items, in addition to selected items,
[0018] U.S. Pat. No. 5,007,641 granted Apr. 16, 1991 to Seidman and U.S. Pat. No. 5,080,364 granted Jan. 14, 1992 to Seidman discloses a promotional game on an automated redemption machine. Prizes are awarded at random to patrons who present appropriate barcoded symbols from coupons or product packages bearing a particular code.
SUMMARY OF THE INVENTION
[0019] Provided herein by this description and claims, is a bulk vending machine for selling items in combination with a redemption certificate for points that can be redeemed at a website for premium prizes by a customer, and for collection of marketing information by the seller, comprising: storage and vend actuation means for a plurality of items, currency validation means for authenticating a customer's payment to provide credit value toward the purchase of an item, a redemption certificate associated with the item, said certificate having security means for validating the certificate in an online registration system, said online registration system comprising a server computer having a database for inputting redemption certificate information and associating said certificate information with customer account information collected during registration, said certificate information comprising points that are stored within the customer account information, said database in operative association with an online point redemption database, wherein customer appreciation prizes are awarded based upon the level of points redeemed by the customer, and wherein marketing information is generated and stored on the server from the combination of customer account information, redemption certificate information, and point redemption database information.
[0020] In a preferred embodiment, the item is a toy, such as light up toys and glow sticks.
[0021] In another preferred embodiment, the vending machine further comprises wherein the marketing information includes time of sale, location of sale, frequency of redemption, and information concerning the prizes redeemed.
[0022] In another preferred embodiment, the vending machine further comprises wherein the prizes are high value electronics including mp3 players, and console gaming stations.
[0023] In another preferred embodiment, there is provided a method for increasing the sales of items offered in a bulk vending machine, comprising: packaging the item in combination with a redemption certificate for points, said certificate redeemable at a website for premium prizes by a customer, and collecting marketing information obtained during the customer's account registration and redemption activities, wherein a plurality of items are stored and offered for sale from a bulk vending machine, and wherein a redemption certificate is packaged with the item, said redemption certificate having security means for validating the certificate in an online registration system, said online registration system comprising a server computer having a database for inputting redemption certificate information and associating said certificate information with customer account information collected during registration, said certificate information comprising points that are stored within the customer account information, said database in operative association with an online point redemption database, wherein customer appreciation prizes are awarded based upon the level of points redeemed by the customer, and wherein marketing information is generated and stored on the server from the combination of customer account information, redemption certificate information, and point redemption database information.
[0024] In another preferred embodiment, the method further comprises wherein the marketing information includes time of sale, location of sale, frequency of redemption, and information concerning the prizes redeemed.
[0025] In another preferred embodiment, the method further comprises wherein the prizes are high value electronics including mp3 players, and console gaming stations.
[0026] In another preferred embodiment, a vending machine marketing system is provided, which comprises: a server subsystem for serving content, via a communication network, to a user computer, and for receiving one or both of data and commands from the user computer; a registration subsystem for verifying and then registering the user, wherein the verifying includes determining a validity of a redemption certificate obtained with the purchase of a light up toy or glow in the dark novelty from a vending machine, and wherein the registering is for allowing the user to access a restricted portion of the vending machine marketing system; and a prize redemption subsystem for providing a user with a delivered prize based upon redemption of points associated with the redemption certificate.
[0027] In another preferred embodiment, a vending machine marketing system is provided, which comprises: a storage subsystem for storing data relating to a plurality of registration codes, each of the registration codes corresponding to one of a plurality of redemption certificates sold with an item from a vending machine; a server subsystem for serving content, via a communication network, to a user computer, and for receiving one of the registration codes transmitted from the user computer via one or both of the communication network and an additional communication network; a registration subsystem for verifying the one of the registration codes against the data relating to the plurality of registration codes, and subsequently registering the user in the system after the verifying; and a prize redemption subsystem for providing a user with a delivered prize based upon redemption of points associated with the redemption certificate.
[0028] In another preferred embodiment, a computer readable medium is provided for storing computer readable program code for performing the methods claimed or disclosed herein by utilizing a computer system as claimed or disclosed herein.
BRIEF DESCRIPTION OF THE FIGURES
[0029] FIG. 1 is a photographic representation of a web-based glow machine.
[0030] FIG. 2 is a photographic representation of an original glow machine.
[0031] FIG. 3 is a a schematic block diagram of a current embodiment of the system and its interactions with some external entities.
[0032] FIG. 4 shows a schematic diagram of a possible hardware implementation of an embodiment of the invention.
[0033] FIG. 5 shows a schematic diagram of a more complex hardware implementation of another embodiment of the invention.
[0034] FIG. 6 shows a manner of a user registering with the System of the current embodiment for utilizing the System features.
[0035] FIG. 7 shows a block diagram of another embodiment of the system and its interactions with some external entities.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] A conventional vending machine for dispensing a variety of items is used. FIGS. 1 and 2 show a vending machine selling encapsulated light up toys and glow in the dark novelties. A customer will normally deposit coins or bill into the vending machine at a coin entry slot or bill entry slot for validation by a corresponding coin validator or bill validator within the machine. The amount of currency validated by the machine may be shown on a display. When sufficient currency has been deposited to enable the machine to vend one of its products, corresponding selection buttons are enabled to permit the customer to make his selection and activate the vending of the selected product through the delivery chute. Any excess accumulated credit value is returned to the patron by a coin changer through the coin return.
[0037] Most of today's vending machines have a standardized communication interface called MDB (Multi-Drop Bus) to enable the various machine components to communicate with one another even though they may have been produced by separate manufacturers. The MDB protocol is maintained and managed by the National Association For Automated Merchandising (NAMA) and is here incorporated by reference. MDB is an RS-232 derivative having an optically coupled interface and a master/multi-slave topology. It uses a pair of 6-pin Molex Mini-Fit Jr. connectors to carry both communications and power. Its protocol allows the controller to know when coins have been received by the coin validator, to know when bills have been received by the bill validator, to know how full the coin changer is, and to command the coin changer to return any excess credit to the customer when the vend cycle has been completed. Part of the MDB protocol includes identification of up to 16 different coin or token types.
[0038] The current system functions basically as follows: A consumer purchases an encapsulated light up toy or glow in the dark novelty from a vending machine. The toy or novelty is contained within a plastic capsule, and the container includes a redemption certificate. The redemption certificate can take the form of a tag, piece of paper, other indicator or storage device, having a registration code and directions for directing the customer to a web site address. The customer/user can load the System web site using the web address in a browser application running on the user's computer, and then enter the registration certificate code. Each registration certificate can have the same, or different, quantities of points associated with it. In preferred embodiments, the customer is directed to establish a customer account. Marketing information, taken from the registration code process and/or the customer account formation process, is collected and provided to the vendor. Once the customer account reaches pre-determined point totals, the customer may redeem the points for prizes, which are then shipped to the customer using the address information provided by the customer.
[0039] The System of the current embodiment utilizes a server subsystem including a web server subsystem for generating both dynamic and static web pages as is known in the art, and for receiving data and./or commands from the user computer. One or more databases support the functioning of this server subsystem. The web server utilizes various scripting or other executable programs for providing dynamic content to the user's computer, which is attached to the web server via some computer network, such as the Internet, for example. The web server can also utilize various animated motion programs, such as a Flash program, java scripts, etc., to provide dynamic content to the user.
[0040] In order to provide the customer with the redemption certificate, a ticket printer, e.g. a barcoded ticket printer, such as the PSA-66-ST by FutureLogic, may be used to produce coded redemption certificates that contain codes to redeem prizes at the web glow machine website. Once the customer, receives the certificate and enters the information into the web interface, a customer account is created and marketing information is collected. The customer account holds the points accumulated from the customer's certificate entries, which can then be redeemed at various levels for increasingly valuable prizes, such as mp3 players, video game consoles, and so forth.
[0041] Information from each machine is transmitted on a regular basis from each of the machines over an internet or intranet link to a remote database. Code printing and barcode printing software, such as that available from Avery Dennison Corporation, provides serialization capability for 1D and 2D barcodes. When barcodes are entered into a control computer, it is validated and stored in its local database. If the serial number has been previously read, then it is not validated.
[0042] In one embodiment, the certificate may take the form of an RFID tag. RFID tags compliant with the EPC96 standard carry a product identification code as well as a product serial number. The data read from an RFID tag is treated the same as previously described for the serialized code or barcode style redemption certificate.
[0043] The vending machine marketing system is comprised of a server subsystem for interacting with the customers/users via a user computer being operated by the user. The server subsystem can utilize a server, for serving content, including web pages, data, commands, and/or programs, for example, to the user computer. In addition, the server subsystem can include a reception subsystem, for receiving information and commands from the users. Alternatively, the server and reception subsystem might be combined into a single computer application, such as a commercially available web server, for example, running on one or more computers. The current system will utilize commercially available applications to implement much of the server subsystem.
[0044] The vending machine marketing system also comprises a Storage Subsystem, for storing system data, user IDs and passwords, toy registration codes, personalized user information, etc. utilized by the various subsystems. The Storage Subsystem of the current system will utilize a commercially available database application running on commercially available hardware, for example.
[0045] A Registration Subsystem is used within the vending machine marketing system for registering the user and the user's toy into the system. In one embodiment, this can provide the user with access to restricted portions of the system. The Registration Subsystem may utilize its own dedicated application and hardware, or could be combined with or share the Server Subsystem applications and/or hardware. The registration subsystem examines the registration code against stored data relating to a plurality of registration codes.
[0046] A Prize Redemption Subsystem generates and/or provides the redemption data to be served by the server to the users for use in displaying the redemption information on the users computers. This data is obtained and/or derived from data stored in the Storage Subsystem.
[0047] The Subsystems may utilize unique applications and/or hardware, or may be combined with one or more of the other Subsystems and/or the Server Subsystem applications and hardware.
[0048] Referring now to the figures, FIG. 1 shows how the capsule toys having the glow in the dark feature are displayed, and how the standard vending machine features are also included, such as money slot, vend buttons, instructions, toy dispensing trough, and display of internet certificate instructions.
[0049] FIG. 2 shows an original glow machine displaying the capsule toys that have the glow in the dark feature are displayed, and the standard vending machine features, such as money slot, vend buttons, instructions, and toy dispensing trough.
[0050] FIG. 3 Shows a top-level block diagram of the vending machine marketing system, interacting with various users 10 . The users 10 should have previously purchased and registered one or more toys from a Vending Machine 9 , who obtained the toys from a manufacturer 8 , or via a distributor.
[0051] FIG. 4 shows an example implementation of the vending machine marketing system, in one of its simplest forms. The system 1 A comprises a server 12 , a database 14 , and a router/modem 16 to connect to a public communications network 20 . A user 10 A, utilizing a workstation 18 , is also connected to the communications network via a router and/or modem 19 , for example. In this implementation, the server 12 , along with the database 14 and router/modem 16 and the appropriate software, implement all of the subsystem functions of the System by executing various application programs on the server 12 hardware, for example. Of course, the system 1 A may also support many additional users in a manner similar to that shown for user 10 A, for example.
[0052] The current embodiment can utilize the Internet as the public communications network. However, other communications networks could be utilized, such as telephone networks, cellular networks, dedicated networks, cable TV networks, power lines, etc. Furthermore, combinations of these networks can be used for various functions. However, because of the ubiquitous nature of the Internet, a solution utilizing that diverse network (which can utilize many individual communications networks) is utilized in the current embodiment.
[0053] Furthermore, the System might also utilize a private communication network for at least part of the system. For example, the Registration Subsystem 6 of FIG. 3 might be connected to a private computer network located at the retail store 8 , where the user might register the toy, for example, as discussed in more detail below. Alternatively, the toy might automatically be registered at the time of purchase (e.g., by scanning a code at the register, for example), and thus not require any user interaction at all beyond purchasing the toy. Or the user might send in a registration card to implement registration, as another example.
[0054] FIG. 5 shows a more complex implementation 1 B of the System. In this example system 1 B, a plurality of servers 21 A- 21 n can be utilized to implement the server subsystem 2 functions of FIG. 3 . Furthermore, a plurality of CPUs 23 A- 23 n can be utilized to implement the Virtual World Providing Subsystem 7 functions of FIG. 3 . A plurality of database storage devices 25 A- 25 n may be used to implement the Storage Subsystem 5 functions of FIG. 3 . And a CPU 30 can be used to implement the Registration Subsystem 6 functions of FIG. 3 , for example. Finally, a router 29 can be used to connect to the Public Communications Network 20 .
[0055] Note that, although FIG. 5 shows multiple servers 21 A-n, multiple CPUs 23 A-n, and multiple databases 25 A-n, any of these might be implemented on one or more shared computers in various configurations, executing one or more computer program applications, as desired. As the number of users supported by the system 1 C grows, additional hardware can be added to increase the capacity of the system, as necessary, in a manner similar to that shown in the Figure.
[0056] Continuing with FIG. 5 showing the more complex implementation 1 B, a plurality of users can be supported in various configurations. For example, a plurality of users 10 B operating single workstations 18 A- 18 n, individually connected to the public communications network 35 , can be supported. Furthermore, complex user networks can also be supported. Retailers and or Toy Manufacturers might also have access to the system, as represented by the example shown in 8 A, should an online-ordering system be implemented for selling toys. Of course, alternate implementations are also possible, depending on the types and number of users and/or retailers being supported, and also depending on the state-of-the-art computer technology.
[0057] In one embodiment, the System uses an Apache web server running in a Linux environment. For webserver hardware, an Intel 2 Ghz+CPUs with 2 GB RAM running Gentoo linux with the appropriate extensions (e.g., mod_php4 and mod_perl) can be utilized. The server will serve flash content to a web browser running a web browser application using PHP, Perl, and actionscript, and flash plugins. A MySQL database application will also be utilized for the storage subsystem.
[0058] The client (user) side Flash application make the calls to a number of PHP files. These PHP files then “interface” with the MySQL database to obtain the necessary data. All are served by the Apache web server, which can serve HTML, XML, along with the appropriate flash and other content.
[0059] This is effectively a 3 layer type of setup: Flash layer⇄PHP layer (this handles requests to the back end)⇄MySQL database, as shown in FIG. 1A . FIG. 1B shows the interaction between the client (user) and server subsystem data flows in more detail. A dedicated database server running MySQL on a dedicated computer running the Gentoo linux OS can be used in the current system.
[0060] A secure Apache SSL server can be utilized for the registration subsystem, likely sharing the computer with the other Apache server.
[0061] One implementation of the current system utilizes an Apache Secure Web server for serving files over secure connection (HTTPS, SSL mode), and an Apache Web server for serving files over regular HTTP.
[0062] User registration is a flash application with PHP backend. The user registration uses a form-driven flash application which validates the registration code and creates a user account within the system. A form driven flash application is designed for guiding the user through the registration and account creation process, and validating the registration code.
[0063] An authentication/login process is a flash application validating user credentials on the server side and spawning an API core in case of validation. It also has module designed for password retrieval based on collected user information, and currently passes user data to a client side API, and may in the future pass user data and a generated encryption key for a current session to a client side API.
[0064] To ensure users privacy, prevent cheating and preserve validity/authenticity of information, additional security layers can be designed which encrypts all data being passed back and forth in-between parts of the APIs (client/server).
[0065] The chosen Encryption technique of the current embodiment may be a modification of TEA routines, using a Feistel cypher with 128 bit key. Keys are generated at the login stage and securely passed to client side via HTTPS, after which the adoption centre spawns the client side API and passes the encryption data specific for the session. Additional measures which can be taken to prevent cheating and maintain data coherency include using different permutations of the original key for every data transmission.
[0066] Referring now to FIG. 6 , the current system functions basically as follows: A consumer purchases an encapsulated light up toy or glow in the dark novelty from a vending machine. The toy or novelty is contained within a plastic capsule, and the container includes a redemption certificate. The redemption certificate can take the form of a tag, piece of paper, other indicator or storage device, having a registration code and directions for directing the customer to a web site address. The customer/user can load the System web site using the web address in a browser application running on the user's computer, and then enter the registration certificate code. Each registration certificate can have the same, or different, quantities of points associated with it. In preferred embodiments, the customer is directed to establish a customer account. Marketing information, taken from the registration code process and/or the customer account formation process, is collected and provided to the vendor. Once the customer account reaches pre-determined point totals, the customer may redeem the points for prizes, which are then shipped to the customer using the address information provided by the customer.
[0067] Referring now to FIG. 7 , the Prize Redemption Subsystem is shown where the customer/user redeems his or her points within the online store 40 . The store then communicates with warehouse 42 and delivery service 44 to forward prizes to the customer.
[0068] The references recited herein are incorporated herein in their entirety, particularly as they relate to teaching the level of ordinary skill in this art and for any disclosure necessary for the commoner understanding of the subject matter of the claimed invention. It will be clear to a person of ordinary skill in the art that the above embodiments may be altered or that insubstantial changes may be made without departing from the scope of the invention. Accordingly, the scope of the invention is determined by the scope of the following claims and their equitable Equivalents.
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The present invention relates to bulk vending machines that sell items in combination with a redemption certificate for points that can be redeemed at a website for premium prizes by a customer, and for collection of marketing information by the seller.
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FIELD OF THE INVENTION
The present invention relates to novel protoberberine alkaloid derivatives obtained from various protoberberine alkaloids quaternium as substrate through various derivatization reactions or their physiologically acceptable salts, their preparation method and the use of them as a drug for inhibition of ulcerative colitis. The use as anti-ulcerative colitis (UC) drugs of some known protoberberine alkaloid derivatives obtained from various protoberberine alkaloids quaternium as substrate through various derivatization reactions is also involved. The specific protoberberine alkaloid derivatives or their physiologically acceptable salts are as follows: dihydrocoptisine, dihydropseudocoptisine, dihydroberberine, dihydropalmatine, 3-methyldihydrocoptisine, (±)-8-cyanodihydrocoptisine, (±)-8-cyanodihydropseudocoptisine, 8-oxodihydrocoptisine, 8-oxodihydropseudocoptisine, (±)-8-acylmethyldihydrocoptisine, 8-(1-acyl-2-alkyl-ethenyl)-13-alkylcoptisine quaternium, and 8-(1-acyl-2-alkyl-ethenyl)-13-alkylberberine quaternium. The present invention belongs to innovative drug research field.
BACKGROUND OF THE INVENTION
Inflammatory bowel disease (IBD) is a kind of chronic inflammatory disease with its etiology and pathogenesis being unclear up to now. At present, the common clinical IBD includes Crohn's disease (CD) and Ulcerative colitis (UC, also known as chronic non-specific UC), which are reported as high incidence rate, long duration, and recurrent attacks and the like. With increasing knowledge for this disease in the field of medical sciences and the development of medical diagnostic tools in recent years, clinical statistics has made it very clear that approximately 5%-7% of patients of UC will progress toward malignant transformation and probably will lead to cancerization ultimately arisen from UC, with serious dysplasia of intestinal glands and carcinoma of colon and rectum often being formed, and pathologically, the incidence of undifferentiated-type predominates in patients of UC, and too often with high degree of deterioration and poor prognosis. At present, the lack of efficient drug and other effective therapy for the treatment of UC is severe, leading to no complete cure to UC clinically. So it has been identified as nasty disease in the field of medical sciences, which seriously affected the lives of the patients. (At present, there are only several drugs, such as mesalazine (e.g. SASP etc.), immunosuppressive agents, and hormone and on the like, being used to treat UC clinically. Although some efficacy is observed, many problems abound nowadays, such as relapse after treatment and serious side effect, among others).
The lesions of UC are mainly confined to the mucosal layer of colon, too often with ulcer being the most dominant symptom and relapse after treatment and severe gastrointestinal inflammation being its characteristics, which also often implicates rectum and distal colon. These symptoms can also extend to the proximal end, and even the entire colon. According to national collaborative group of IBD, the incidence rate of UC was about 11.62 cases in 100,000 people each year in China, and hospitalized UC patients were mainly mild (35.4%) and moderate (42.9%) cases. In western countries, the morbidity of UC was 79-268 cases in 100,000 people each year, while, in Asia in the late 20th century, it was 7.8-18.1 cases and 8.6 cases in 100,000 people each year in Japan and Singapore, respectively. In recent years, morbidity of UC has shown a tendency of increasing across China (Maybe it is due to our increasing understanding for this disease and the development of medical diagnostic tools). Realistically, getting UC would make patients suffer not only from mental and physical pain, but also from heavy economic burden to themselves.
At the early stage of UC, there can be diffuse inflammation of mucosa, edema, hyperemia, and local hemorrhage, and with diffuse fine granule in the mucosal surface, fragile organization, and easy bleeding when touched also often being observed. Lymphocytes, plasma cells, eosinophils and neutrophils infiltration can be found in the mucosa and submucosa. With the progression of the disease, a large number of neutrophils will gather in the bottom of intestinal glands, leading to the formation of a small crypt abscess. When the crypt abscess are mixed together and broken up, mucosa will show wide shallow small irregular ulcer. The ulcer may develop along the longitudinal axis of colon, merging into irregular large ulcer gradually. In the process of repeated episodes of chronic colitis, a lot of new granulation tissue will proliferate, often together with inflammatory polyp. Due to the continuous damage and repair, mucosa will lose its normal structure and fibrous tissue will increase, leading to atrophic changes such as glands being degenerated, arranged in disorder, and reduced in number. With the healing of ulcer, forming of scar, and hypertrophying of muscular layer of mucosa and muscle layer, the colon will deform, colonic pouch will disappear, and even intestinal lumen will narrow, leading to the organic and functional changes of colon, which will seriously affect the health of human body.
Recent investigations have shown that the occurrence and progression of chronic IBD, including CD and UC, are closely related to an imbalance of microenvironment homeostasis function of intestinal epithelial cells. The disorder of homeostasis function of intestinal epithelial cell can trigger non-controllable endoplasmic reticulum stress response (unresolving ER stress), leading to extensive and persistent endoplasmic reticulum damage in intestinal epithelial cells, often with “programmed cell death”, namely, apoptosis. Also, it has been reported that the occurrence and progression of IBD are closely related to the non-controllable endoplasmic reticulum stress response within intestinal epithelial cells. Especially the abnormality of key downstream transcription factor, X-box-binding protein 1 (xbp1), which associates with non-controllable endoplasmic reticulum stress response within intestinal epithelial cells plays a key role in the incidence of UC.
Generally, the transcription factor xbp1 plays a very important role for the expansion of endoplasmic reticulum and the growth of glandular epithelial cells sharing secretion function, such as plasma cells, islet cells in the pancreas, and salivary gland cells, and for the adaption of epithelial cells to inflammatory stimulation environment. Of almost all cell types from human body, xbp1 serve as a key regulator in maintaining the basic function of endoplasmic reticulum through directly regulating the transcriptional function of a core set of genes. Kaser and coauthors have created a gene knockout mouse model with xbp1 defect of intestinal epithelial cells (XBP1−/−) in 2008 for the first time. They found that animals with xbp1 gene knockout would generate not only the deficiency of Paneth cell and the obvious change of phenotype of goblet cell, but also the spontaneous inflammatory changes in the ileum. At the same time, further discovery was made by researchers on the basis of the above findings that the sense mutant of the xbp1 gene also related closely to the occurrence and progression of IBD. The above experimental results demonstrated that xbp1 gene plays an important role in maintaining the homeostasis of intestinal epithelial cells and in resisting the apoptosis of intestinal epithelial cell induced by ER stress. Similarly, by taking the SNPs technology in clinical studies, it was found that patients getting IBD typically show some variations in the coding region of the xbp1 gene, making them to be more sensitive to predisposing factors of IBD. Taken together, according to research data from not only clinical genetics but also in laboratories, it can be make clear that transcription factor xbp1 plays a very important role in the self homeostasis regulation of intestinal epithelial cell. The failure or weakness of xbp1 expression will increase the sensibility of body to inducing factor of IBD, promote getting IBD, and lead to deterioration of IBD.
However, there has no claim as yet to chemically synthesized small molecule drug or natural medicine monomer in the field of developing innovative anti-IBD drugs with xbp1 as target during recent research across the world. Base on the above findings from laboratory to clinical test, i.e., the research information about the close relationship between the expressive failure and abnormality of xbp1 and the increasing morbidity of IBD, it is speculated that xbp1 may be the potential new drug target for treating IBD. Therefore, the object of the present invention is to screen and discovery selective agonists of xbp1 on the basis of different aspects such as gene transcription regulation of xbp1, mRNA expression, and protein synthesis and the like by establishing drug screening model in vitro with xbp1 as target, in combination with cytology and molecular biology means, mainly including dual luciferase reporter gene, real-time quantitative polymerase chain reaction (PCR) and Western Blot (WB) techniques.
Moreover, the present invention also provides a reliable, accurate, and effective method for discovering anti-IBD drug by high-throughput screening.
The present invention obtains some protoberberine alkaloid derivatives or their physiologically acceptable salts by structure modifications of kinds of protoberberine alkaloid quaternium. In pharmacodynamic experiments at molecular and animal level, these protoberberine alkaloid derivatives show certain or significant anti-UC activity with a few of them showing far more efficiency than substrates and positive drug. Especially, the above mentioned compounds 1, 2, and 7 show significant transcriptional activation effect on xbp1 gene at molecular level in vitro, wherein the EC 50 values are 2.29×10 −9 (mol/L), 7.06×10 −9 (mol/L), and 2.21×10 −7 (mol/L), respectively. On the other hand, in vivo experiments show that the disease activity index (DAI) (including mental state, weight loss, bloody stool, shape of stool and other evaluation indicators) inhibitory rate of compound 7 (500 mg/kg) in UC model is up to 64%, and on the case of compound 1 (300 mg/kg) and 2 (300 mg/kg), the inhibition rates are as high as 69% and 80%, respectively, while the positive drug SASP (300 mg/kg) is only 32%. In addition, the histopathological test results show that the high-dose group of compound 7 (500 mg/kg) has significant improvement on the colon inflammatory lesion, with intestinal epithelial cells arranged perfectly, and even the cell polarity arrangement can recover to the normal physiological state. Therefore, the results from in vivo experiments of different animal species and different pathogenesis demonstrate that the protoberberine alkaloid derivatives obtained in the present invention exhibit far more significant anti-UC activity in vivo than those currently used clinically, such as SASP, and thus they have important medicinal value in preparing drugs for the treatment of UC. In addition, comparing with substrates, the solubility of these prepared protoberberine alkaloid derivatives has also been significantly improved, especially in those poor solvents for substrates.
SUMMARY OF THE INVENTION
The technical matter to be solved by the present invention is to provide a kind of drug for the treatment of UC, that is, the protoberberine alkaloid derivatives as shown in general formula I-VIII or the physiologically acceptable salts thereof.
To solve the above problem, the present invention provides the following technical solutions:
The first aspect of the present invention provides a class of protoberberine alkaloid derivatives as shown in general formula I-VIII or the physiologically acceptable salts thereof.
The second aspect of the present invention provides the preparation method of protoberberine alkaloid derivatives as shown in general formula I-VIII or the physiologically acceptable salts thereof.
The third aspect of the present invention provides the pharmaceutical composition comprising the protoberberine alkaloid derivative as shown in general formula I-VIII or the physiologically acceptable salts thereof.
The fourth aspect of the present invention provides the use of the protoberberine alkaloid derivative as shown in general formula I-VIII or the physiologically acceptable salts thereof in treatment of cancer.
The protoberberine alkaloid derivative as shown in general formula I or the pharmaceutically acceptable salts thereof comprises dihydrocoptisine, dihydroberberine, dihydropalmatine, 8-oxodihydrocoptisine, 8-oxodihydropseudocoptisine:
wherein:
represents a single bond or a double bond;
R 2 and R 3 are independently represents OCH 3 , or R 2 and R 3 form a OCH 2 O together;
when is a single bond, R 8 represents H; when is a double bond, R 8 represents O;
R 9 and R 10 are independently represents OCH 3 with R 11 representing H, or R 9 and R 10 form OCH 2 O together with R 11 representing H, or R 10 and R 11 form OCH 2 O together with R 9 representing H.
13-Substituted dihydrocoptisine derivative as shown in the following general formula (II):
wherein:
R 13 represents H, or R 13 represents aliphatic group of formula C n H 2n+1 or C m H 2m− ,
wherein n represents an integer between 1 and 20, and m represents an integer between 1 and 20; or
R 13 is NHR 13 ′ wherein R 13 ′ is selected from H or alkyl of formula C n H 2n+1 , wherein n represents an integer between 1 and 20; or
R 13 is OR 13 ′ wherein R 13 ′ is selected from H or alkyl of formula C n H 2n+1 , wherein n represents an integer between 1 and 20; or
R 13 is COOR 13 ′ wherein R 13 ′ is selected from H or alkyl of formula C n H 2n+1 , wherein n represents an integer between 1 and 20; or
R 13 is selected from halogen, C1-C20 alkyl sulphanyl, C1-C20 alkylacyl, or C1-C20 alkylacyloxy;
wherein the alkyl in the above aliphatic group, C1-C20 alkyl sulphanyl, C1-C20 alkylacyl, or C1-C20 alkylacyloxy is straight chain or branched chain.
Dihydropseudocoptisine and 13-substituted dihydropseudocoptisine as shown in the following general formula (III):
wherein:
R 13 represents H; or R 13 represents aliphatic group of formula C n H 2n+1 , wherein n represents an integer between 1 and 20; or
R 13 represents aliphatic group of formula C m H 2m−1 , wherein m represents an integer between 2 and 20; or
R 13 is OR 13 ′ wherein R 13 ′ is selected from H or alkyl of formula C n H 2n+1 , wherein n represents an integer between 1 and 20; or
R 13 is CH 2 NHR 13 ′ wherein R 13 ′ is selected from H or alkyl of formula C n H 2n+1 , wherein n represents an integer between 1 and 20; or
R 13 is CH 2 OR 13 ′ wherein R 13 ′ is selected from H or alkyl of formula C n H 2n+1 , wherein n represents an integer between 1 and 20; or
R 13 is CH 2 COOR 13 ′ wherein R 13 ′ is selected from H or alkyl of formula C n H 2n+1 , wherein n represents an integer between 1 and 20; or
R 13 is CH 2 R 13 ′ wherein R 13 ′ is selected from halogen, C1-C20 alkyloxy, C1-C20 alkyl sulphanyl, C1-C20 alkylacyl, or C1-C20 alkylacyloxy;
wherein the alkyl in the above aliphatic group, C1-C20 alkyloxy, C1-C20 alkyl sulphanyl, C1-C20 alkylacyl, or C1-C20 alkylacyloxy is straight chain or branched chain.
8-Substituted dihydrocoptisine and 8-substituted dihydropseudocoptisine as shown in the following general formula (IV):
wherein:
R 8 represents CN; or
R 8 is CH 2 NHR 8 ′ wherein R 8 ′ is selected from H, benzyl or alkyl of formula C n H 2n+1 , wherein n represents an integer between 1 and 20; or
R 8 ′ represents alkyl of formula C m H 2m−1 , wherein m represents an integer between 2 and 20; or R 8 is COOR 8 ′ wherein R 8 ′ is selected from H, benzyl or alkyl of formula C n H 2n+1 , wherein n represents an integer between 1 and 20; or R 8 ′ represents alkyl of formula C m H 2m−1 , wherein m represents an integer between 2 and 20;
R 9 and R 10 form a OCH 2 O together and R 11 represents H; or R 10 and R 11 form a OCH 2 O together and R 9 represents H.
(±)-8-Acylmethyl substituted dihydrocoptisine as shown in the following general formula (V):
wherein:
R 8 ′ represents aliphatic group of formula C n H 2n+1 wherein n represents an integer between 1 and 20; or
R 8 ′ represents aliphatic group of formula C m H 2m−1 , wherein m represents an integer between 2 and 20; or
R 8 ′ is selected from OH, NH 2 , halogen or C1-C20 alkyloxy, C1-C20 alkyl sulphanyl;
wherein the alkyl in the above C1-C20 alkyloxy, C1-C20 alkyl sulphanyl is straight chain or branched chain.
(±)-8-Acylmethyl substituted dihydrocoptisine as shown in the following general formula (VI):
wherein:
R8′ is selected from H, OH, NH 2 , NO 2 , phenyl, methylenedioxy, 1,2-ethylenedioxy, halogen, C1-C20 alkyl, C1-C20 alkyloxy, C1-C20 alkyl sulphanyl, C1-C20 alkylacyl, or C1-C20 alkylacyloxy; wherein the alkyl in the above C1-C20 alkyl, C1-C20 alkyloxy, C1-C20 alkyl sulphanyl, C1-C20 alkylacyl, or C1-C20 alkylacyloxy is straight chain or branched chain.
Protoberberine alkaloid quaternium as shown in the following general formula (VII), comprising 8-(1-acyl-2-alkyl-ethenyl)-13-alkylcoptisine quaternium and 8-(1-acyl-2-alkyl-ethenyl)-13-alkylberberine quaternium:
wherein:
R 8 ′ represents aliphatic group of formula C n H 2n+1 , wherein n represents an integer between 1 and 20, or R 8 ′ represents aliphatic group of formula C m H 2m−1 , wherein m represents an integer between 2 and 20; or
R 8 ′ is selected from OH, NH 2 , halogen, C1-C20 alkyloxy, C1-C20 alkyl sulphanyl;
wherein the alkyl in the above C1-C20 alkyloxy, C1-C20 alkyl sulphanyl is straight chain or branched chain;
R 9 and R 10 independently represents OCH 3 , or R 9 and R 10 form a OCH 2 O together;
R 13 is H or R 13 represents aliphatic group of formula C n H 2n+1 , wherein n represents an integer between 1 and 19.
Protoberberine alkaloid quaternium as shown in the following general formula (VIII), comprising 8-(1-acyl-2-alkyl-ethenyl)-13-alkylcoptisine quaternium and 8-(1-acyl-2-alkyl-ethenyl)-13-alkylberberine quaternium:
wherein:
R8′ represents H, OH, NH 2 , NO 2 , phenyl, methylenedioxy, 1,2-ethylenedioxy, halogen, C1-C20 alkyl, C1-C20 alkyloxy, C1-C20 alkyl sulphanyl, C1-C20 alkylacyl, or C1-C20 alkylacyloxy;
wherein the alkyl in the above C1-C20 alkyl, C1-C20 alkyloxy, C1-C20 alkyl sulphanyl, C1-C20 alkylacyl, or C1-C20 alkylacyloxy is straight chain or branched chain;
R 9 and R 10 independently represents OCH 3 , or R 9 and R 10 form a OCH 2 O together;
R 13 is H or R 13 represents aliphatic group of formula C 1 H 2n+1 , wherein n represents an integer between 1 and 19.
The most preferred compounds of the present invention are selected from the group consist of compounds 1-29:
The second aspect of the present invention provides the preparation methods of the present compounds. Said protoberberine alkaloid derivatives or their physiologically acceptable salts can be synthesized, respectively, by the following synthetic methods:
(1) Dihydrocoptisine, dihydropseudocoptisine, dihydroberberine, dihydropalmatine, and 13-methyldihydrocoptisine of the present invention can be synthesized by the following synthetic method:
(2) (±)-8-Cyanodihydrocoptisine and (±)-8-cyanodihydropseudocoptisine of the present invention can be synthesized by the following synthetic method:
(3) 8-Oxodihydropseudocoptisine of the present invention can be synthesized by the following synthetic method:
(4) 8-Oxodihydrocoptisine of the present invention can be synthesized by the following synthetic method:
(5) (±)-8-Acylmethyl substituted dihydrocoptisine, 8-(1-acyl-2-alkyl-ethenyl)-13-alkylcoptisine quaternium and 8-(1-acyl-2-alkyl-ethenyl)-13-alkylberberine quaternium of the present invention can be synthesized by the following synthetic method:
The third aspect of the present invention also relates to the pharmaceutical compositions comprising the present compounds as active ingredients. Methods for preparing said pharmaceutical compositions will be readily apparent to those skilled in the art. The present compounds can be combined with one or more pharmaceutically acceptable solid or liquid excipient and/or adjuvant to form any dosage form suitable for human or animal use. Generally, the pharmaceutical composition will comprise from 0.1 wt % to 95 wt % of the present compounds.
The present invention compounds or its pharmaceutical compositions may be administered intestinally or parenterally in unit dosage form, for example, oral, intravenous, intramuscular, subcutaneous, nasal, oral mucosa, ocular, lung, respiratory tract, skin, vagina, rectum etc.
The dosage form may be liquid, solid or semi-solid formulation. Liquid formulation may be, for example, solution (including true solution and colloid solution), emulsions (including o/w type, w/o type and multiple emulsions), suspensions, injections (including aqueous injections, powder and infusion), eye drops, nasal drops, lotions and liniments, etc.; solid formulation may be, for example, tablets (including conventional tablets, enteric-coate tablets, lozenges, dispersible tablets, chewable tablets, effervescent tablets, orally disintegrating tablets), capsules (including hard capsules, soft capsules, enteric capsules), granules, powders, pellets, pills, suppositories, films, patches, gas (powder) aerosols, sprays, etc.; semi-solid formulation may be, for example, ointments, gels, pastes, etc.
The present compounds may be formulated into general preparations, also sustained release preparations, controlled-release preparations, targeting preparations and particulate delivery systems.
Tablets can be prepared by mixing the present compounds with various widely used excipients what is known in the art, including diluents, binders, wetting agents, disintegrants, lubricants, glidants. Diluents may be starch, dextrin, sucrose, glucose, lactose, mannitol, sorbitol, xylitol, microcrystalline cellulose, calcium sulfate, calcium hydrogen phosphate, calcium carbonate, etc.; wetting agents may be water, ethanol, isopropanol, etc.; binder may be starch, dextrin, syrup, honey, glucose solution, microcrystalline cellulose, arabic gum, gelatin, sodium carboxymethyl cellulose, methyl cellulose, hydroxypropylmethyl cellulose, ethyl cellulose, acrylic resins, carbomer, polyvinyl pyrrolidone, polyethylene glycol, etc.; disintegrants may be dry starch, microcrystalline cellulose, low substituted hydroxypropyl cellulose, cross-linked poly vinyl pyrrolidone, cross-linked sodium carboxymethyl cellulose, sodium carboxymethyl starch, sodium bicarbonate and citric acid, polyoxyethylene sorbitan fatty acid esters, sodium lauryl sulfate, etc.; lubricants and glidants may be talc, silicon dioxide, stearate, tartaric acid, liquid paraffin, polyethylene glycol, etc.
Tablets may be further treated with suitable coating materials, for example, sugar-coated tablets, film-coated tablets, enteric coated tablets, or double tablets and multilayer tablets.
In order to prepare capsules, the present compounds may be mixed with diluents, glidants and the mixture is directly placed into hard or soft capsules. The present compounds may also be formulated into granules or pellets with diluents, binders, and disintegrants, and then placed into hard or soft capsules. The diluents, binders, wetting agents, disintegrants, glidants which are used in the preparation of tablets can also be used to prepare capsules of the present compounds.
The present compounds may be formulated into injection, using water, ethanol, isopropanol, propylene glycol or their mixture as solvents, and adding an appropriate amount of solubilizers, cosolvents, pH modifiers, osmo-regulators widely used in this field. Solubilizers or cosolvents may be poloxamer, lecithin, hydroxypropyl-β-cyclodextrin etc.; pH modifiers may be phosphate, acetate, hydrochloric acid, sodium hydroxide, etc.; osmo-regulators may be sodium chloride, mannitol, glucose, phosphate, acetate, etc. For the preparation of freeze-dried powder injection, proppants such as mannitol, glucose and the like may be added.
Moreover, if necessary, the pharmaceutical formulations may be added with colourants, preservatives, fragrances, flavorants or other additives.
To achieve the purpose of the medication, enhance the therapeutic effect, the present compounds or pharmaceutical compositions can be administered via any known route.
The dosage of the pharmaceutical compositions may vary in a wide range according to the nature and severity of the disease, the individual circumstances of the patient or animal, route of administration and the dosage form. In general, the suitable daily dose of the present compounds is 0.001-150 mg/Kg body weight, preferably 0.1-100 mg/Kg body weight, more preferably 1-60 mg/Kg body weight, most preferably 2-30 mg/Kg body weight. The above mentioned dosage may be administered at one dosage unit or several dosage units, depending on the doctor's clinical experience and therapeutic regimens including other means.
The present compounds or pharmaceutical compositions may be administered alone or in combination with other therapeutic or symptomatic drugs. When there is a synergistic effect between the present compounds and other therapeutic agents, the dose should be adjusted according to actual situation.
In the fourth aspect, the present invention provides the application of the compounds in the preparation of drugs for the treatment of UC. In activity test experiments at molecular and animal levels, the protoberberine alkaloid derivatives and their physiologically acceptable salts involved in the present invention show significant or certain anti-UC activity with a few of them showing far more efficacy than substrates and positive drug, and thus they have important medicinal value in the treatment of UC. Especially, the above mentioned compounds 1, 2, and 7 show significant transcriptional activation effect on xbp1 gene in vitro, wherein the EC 50 values are 2.29×10 −9 (mol/L), 7.06×10 −9 (mol/L), and 2.21×10 −7 (mol/L), respectively. On the other hand, animal experiments in vivo show that, the disease activity index (DAI) (including mental state, weight loss, bloody stool, shape of stool and other aspects of evaluation) inhibitory rate of compound 7 (500 mg/kg) in UC model is up to 64%, and on the case of compound 1 (300 mg/kg) and 2 (300 mg/kg), the inhibition rates are as high as 69% and 80%, respectively, while the positive drug SASP (300 mg/kg) is only 32%. In addition, the histopathological test results show that the high-dose group of compound 7 (500 mg/kg) has significant improvement on the inflammatory lesion, with intestinal epithelial cells arranged perfectly, and even the cell polarity arrangement can recover to the normal physiological state. Therefore, the results from in vivo experiments of different animal species and different pathogenesis demonstrate that the protoberberine alkaloid derivatives obtained in the present invention exhibit far more significant anti-UC activity in vivo than those currently used clinically, such as SASP, and thus they have important medicinal value in preparing drugs for the treatment of UC. In addition, comparing with substrates, the solubility of these prepared protoberberine alkaloid derivatives has also been significantly improved, especially in those poor solvents of substrates.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the results of toxicity test of each compound for intestinal epithelial cells IEC-6 determined by MTT assay in vitro.
FIG. 2 shows the results of activating effect on xbp1 upstream promoter of different compounds of the present invention.
FIG. 3 shows that the EC 50 value of compound 1 is 2.29×10 −9 (mol/L).
FIG. 4 shows that the EC 50 value of compound 2 is 7.06×10 −9 (mol/L).
FIG. 5 shows that the EC 50 value of compound 7 is 2.21×10 −7 (mol/L).
FIG. 6 shows that the EC 50 value of compound 10 is 4.73×10 −8 (mol/L).
FIG. 7 shows the effect of compound 7 on the weight of rats suffering from UC.
FIG. 8 shows the effect of compound 7 on the pathological change of colon tissue of rats suffering from UC.
FIG. 9 shows the effect of compound 7 on the pathological change of colon tissue of C57/blc mice suffering from UC.
DETAILED DESCRIPTION OF THE INVENTION
Preparation Example 1
Preparation Process of Compounds 1-29 and their Structural Identification Data
Preparation of Compound 1
To a stirred solution of coptisine (102 mg, 0.29 mmol) and K 2 CO 3 (110 mg, 0.80 mmol) in methanol (4 mL), 5% NaOH solution (0.8 mL) containing NaBH 4 (9 mg, 0.24 mmol) was added dropwise in ice bath. After addition, the ice bath was removed and the reaction mixture was stirred continually at room temperature for 3 h until the reaction completed. The precipitated product was filtered, washed with 30% ethanol (5 mL) and 80% ethanol (3 mL) and then recrystallized from ethanol to provide yellow solid (59 mg, 64.1% yield).
1 H-NMR (DMSO-d 6 ) δ (ppm): 2.78 (t, J=5.7 Hz, 2H, NCH 2 C H 2 ), 3.04 (t, J=5.7 Hz, 2H, NC H 2 CH 2 ), 4.15 (s, 2H, NCH 2 ), 5.96 (s, 2H, OCH 2 O), 5.99 (s, 2H, OCH 2 O), 6.08 (s, 1H, ArH), 6.46 (d, J=7.8 Hz, 1H, ArH), 6.68 (d, J=7.8 Hz, 1H, ArH), 6.74 (s, 1H, ArH), 7.28 (s, 1H, ArH). MS (m/z): 321.3.
Preparation of Compound 2
To a stirred solution of pseudocoptisine (310 mg, 0.87 mmol) and K 2 CO 3 (300 mg, 2.17 mmol) in methanol (8 mL), 5% NaOH solution (1.5 mL) containing NaBH 4 (33 mg, 0.87 mmol) was added dropwise. The reaction mixture was stirred at room temperature for 3 h until the reaction completed and the precipitated product was filtered, washed to neutral with water and then dried to provide yellow solid (222 mg, 79.3% yield).
1 H-NMR (DMSO-d 6 ) δ (ppm): 2.78 (t, J=5.7 Hz, 2H, NCH 2 C H 2 ), 3.00 (t, J=5.7 Hz, 2H, NC H 2 CH 2 ), 4.06 (s, 2H, NCH 2 Ar), 5.91 (s, 2H, OCH 2 O), 5.99 (s, 2H, OCH 2 O), 6.04 (s, 1H, ArH), 6.57 (s, 1H, ArH), 6.70 (s, 1H, ArH), 6.75 (s, 1H, ArH), 7.26 (s, 1H, ArH).
Preparation of Compound 3
To a stirred solution of berberine (810 mg, 2.18 mmol) and K 2 CO 3 (753 mg, 5.45 mmol) in methanol (8 mL), 5% NaOH solution (1.5 mL) containing NaBH 4 (83 mg, 2.19 mmol) was added dropwise. The reaction mixture was stirred at room temperature for 3 h until the reaction completed and the precipitated product was filtered, washed to neutral with water and then dried to provide yellow solid (619 mg, 84.2% yield).
1 H-NMR (CDCl 3 ) δ (ppm): 2.78 (t, J=5.7 Hz, 2H, NCH 2 C H 2 ), 3.04 (t, J=5.7 Hz, 2H, NC H 2 CH 2 ), 3.70 (s, 3H, OCH 3 ), 3.75 (s, 3H, OCH 3 ), 4.20 (s, 2H, NCH 2 Ar), 5.99 (s, 2H, OCH 2 O), 6.04 (s, 1H, ArH), 6.68 (d, J=8.4 Hz, 1H, ArH), 6.74 (s, 1H, ArH), 6.81 (d, J=8.7 Hz, 1H, ArH), 7.28 (s, 1H, ArH).
Preparation of Compound 4
To a stirred solution of palmatine (82 mg, 0.21 mmol) and K 2 CO 3 (72 mg, 0.52 mmol) in methanol (5 mL), 5% NaOH solution (0.5 mL) containing NaBH 4 (8 mg, 0.21 mmol) was added dropwise. The reaction mixture was stirred at room temperature for 3 h until the reaction completed and the precipitated product was filtered, washed to neutral with water and then dried to provide yellow solid (59 mg, 79.0% yield).
1 H-NMR (CDCl 3 ) δ (ppm): 2.91 (t, J=5.4 Hz, 2H, NCH 2 C H 2 ), 3.16 (t, J=5.4 Hz, 2H, NC H 2 CH 2 ), 3.85 (s, 6H, 2OCH 3 ), 3.89 (s, 3H, OCH 3 ), 3.94 (s, 3H, OCH 3 ), 4.33 (s, 2H, NCH 2 Ar), 6.00 (s, 1H, ArH), 6.60 (s, 1H, ArH), 6.75 (s, 1H, ArH), 7.18 (s, 1H, ArH).
Preparation of Compound 5
Coptisine (300 mg, 0.84 mmol) was dissolved in methanol (8 mL), water solution (1 mL) containing KCN (55 mg, 0.84 mmol) was added dropwise. The reaction mixture was stirred at room temperature for 2 h until the reaction completed. Then, the reaction mixture was filtered and the filter cake was washed with water and then dried to provide yellow solid (230 mg, 79.0% yield).
1 H-NMR (DMSO-d 6 ) δ (ppm): 2.79-2.84 (m, 2H, NCH 2 C H 2 ), 3.05-3.15 (m, 1H, NC H 2 CH 2 ), 3.44-3.48 (m, 1H, NC H 2 CH 2 ), 6.01 (s, 2H, OCH 2 O), 6.03 (d, J=3.6 Hz, 2H, OCH 2 O), 6.17 (s, 1H, CHCN), 6.41 (s, 1H, ArH), 6.66 (d, J=7.8 Hz, 1H, ArH), 6.79 (s, 1H, ArH), 6.90 (d, J=8.1 Hz, 1H, ArH), 7.36 (s, 1H, ArH).
Preparation of Compound 6
Pseudocoptisine (37 mg, 0.10 mmol) was dissolved in methanol (3 mL), and water solution (0.5 mL) containing KCN (7 mg, 0.11 mmol) was added dropwise. The reaction mixture was stirred at room temperature for 2 h until the reaction completed. Then, the reaction mixture was filtered and the filter cake was washed with water and then dried to provide yellow solid (9 mg, 25.0% yield).
1 H-NMR (DMSO-d 6 ) δ (ppm): 2.86 (br s, 2H, NCH 2 C H 2 ), 3.15-3.35 (m, 2H, NC H 2 CH 2 ), 5.80 (s, 1H, CHCN), 6.01-6.03 (m, 4H, OCH 2 O), 6.36 (s, 1H, ArH), 6.75 (s, 1H, ArH), 6.80 (s, 1H, ArH), 6.93 (s, 1H, ArH), 7.34 (s, 1H, ArH).
Preparation of Compound 7
To a stirred solution of coptisine (99 mg, 0.28 mmol) in 5N NaOH (1.5 ml), acetone (0.2 mL, 2.7 mmol) was added dropwise. The reaction mixture was stirred at room temperature for 1 h until the reaction completed. The reaction mixture was filtered and the filter cake was washed to neutral with water, and then recrystallized from acetone to provide yellow solid (59 mg, 56.2% yield).
1 H-NMR (DMSO-d 6 ) δ (ppm): 2.01 (s, 3H, CHCH 2 COC H 3 ), 2.43-2.49 (m, 1H, CHC H 2 COCH 3 ), 2.68-2.75 (m, 2H, NCH 2 C H H 2 ), 2.91 (dd, J 1 =14.4 Hz, J 2 =5.7 Hz, 1H, CHC H 2 COCH 3 ), 3.17-3.23 (m, 2H, NC H 2 CH 2 ), 5.08 (t, J=5.7 Hz, 1H, C H CH 2 COCH 3 ), 5.89 (s, 1H, ArCH═C), 5.96-6.02 (m, 4H, 2OCH 2 O), 6.49 (d, J=7.8 Hz, 1H, ArH), 6.71 (d, J=7.8 Hz, 1H, ArH), 6.75 (s, 1H, ArH), 7.24 (s, 1H, ArH). MS (m/z): 337.2.
Preparation of Compound 8
A stirred mixture of heliotropin (411 mg, 2.74 mmol) and homopiperony lamine (0.5 mL, 3.04 mmol) was heated at 160° C. for 1 h. Then, the temperature was allowed to fall to 80° C. and CH 3 OH (6 mL) was added. When the temperature returned to room temperature, NaBH 4 (125 mg, 3.30 mmol) was slowly added portion wise and the mixture was refluxed for an additional 1 h, then cooled to room temperature, and poured into water (10 mL). The aqueous phase was extracted with CHCl 3 and the organic layer was washed with brine, and dried over anhydrous MgSO 4 and then filtered. Concentration of the organic layer in vacuo followed by purification of the residue by column chromatography (silica gel, CHCl 3 /CH 3 OH (v/v), 100:1) gave yellow oil as an intermediate product (795 mg, 97.0% yield).
1 H-NMR (DMSO-d 6 ) δ (ppm): 2.86-2.91 (m, 2H, NCH 2 C H 2 ), 2.99-3.05 (m, 2H, NC H 2 CH 2 ), 4.04 (s, 2H, NCH 2 Ar), 5.97 (s, 2H, OCH 2 O), 6.04 (s, 2H, OCH 2 O), 6.68 (dd, J 1 =8.1 Hz, J 2 =1.5 Hz, 1H, ArH), 6.82 (s, 1H, ArH), 6.84 (d, J=8.1 Hz, 1H, ArH), 6.94 (d, J=8.1 Hz, 1H, ArH), 7.00 (dd, J 1 =8.1 Hz, J 2 =1.5 Hz, 1H, ArH), 7.16 (d, J=1.5 Hz, 1H, ArH).
Anhydrous CuSO 4 (4.2 g, 26.32 mmol) was dissolved in formic acid (15 mL) in reaction flask and maintained in 50° C. oil bath for 30 min to dehydration. The above obtained yellow oil (3.987 g, 13.32 mmol) and glyoxal (3.4 mL, 26.71 mmol) were added and the reaction mixture was heated to 100° C. and stirred for 4 h. During the reaction, concentrated hydrochloric acid was added in following order: 0.3 mL of con. HCl was added when the thermal preservation was up to 45 min; 0.3 mL was added when it was up to 90 min; 0.4 mL was added when it was up to 150 min; 0.4 mL was added when it was up to 210 min; and then 0.3 mL was added when it was up to 230 min. When the addition was completed, the reaction was carried on for 10 min, and then allowed to cool down to 10° C. to freeze for 1 h. The reaction mixture was filtered and the filter cake was dried and then recrystallized from DMF to provide pseudocoptisine (1.15 g, 24.3% yield) and recrystallized from 80% CH 3 OH to provide compound 8 (718 mg, 16.1% yield).
1 H-NMR (DMSO-d 6 ) δ (ppm): 3.01 (t, J=5.7 Hz, 2H, NCH 2 C H 2 ), 4.53 (t, J=5.7 Hz, 2H, NC H 2 CH 2 ), 6.04 (s, 2H, OCH 2 O), 6.26 (s, 2H, OCH 2 O), 6.92 (s, 1H, ArH), 7.39 (s, 1H, ArH), 7.67 (s, 1H, ArH), 8.40 (s, 1H, ArH), 8.58 (s, 1H, ArH).
Preparation of Compound 9
Potassium ferricyanide (2.2 g, 6.68 mmol) was dissolved in the solution of 5N NaOH (5 mL) followed by addition of coptisine (500 mg, 1.41 mmol). The mixture was refluxed for 10 h until the reaction completed, and then allowed to return to room temperature. The reaction mixture was filtered and filter cake was washed with water to neural and then dried to give yellow solid (344 mg, 73.0% yield).
1 H-NMR (DMSO-d 6 ) δ: 2.86 (t, J=5.4 Hz, 2H, NCH 2 C H 2 ), 4.09 (t, J=5.4 Hz, 2H, NC H 2 CH 2 ), 6.07 (s, 2H, OCH 2 O), 6.19 (s, 2H, OCH 2 O), 6.92 (s, 1H, ArH), 7.11 (s, 1H, ArH), 7.15 (d, J=8.1 Hz, 1H, ArH), 7.34 (d, J=8.1 Hz, 1H, ArH), 7.47 (s, 1H, ArH).
Preparation of Compound 10
To a stirred solution of berberine (95 mg, 0.26 mmol) in 5N NaOH (1 ml), butanone (0.3 mL, 3.35 mmol) was added dropwise. After addition, the reaction mixture was heated to 60° C. for 3 h and then the reaction mixture was extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was washed to neutral with water, dried over anhydrous MgSO 4 and then filtered and concentrated under reduced pressure to give crude product. The crude product was dissolved in anhydrous tetrahydrofuran (3 mL) followed by addition of HOAc (0.5 mL) and formaldehyde (0.6 mL, 6.02 mmol) dropwise. The reaction mixture was refluxed for 3 h. After the reaction completed, the reaction mixture was concentrated and added with 2 N HCl (2 mL), then stirred at room temperature for 1 h and extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was dried over anhydrous MgSO 4 and then filtered and concentrated under reduced pressure to give crude product, which was purified via silica gel column chromatography (CHCl 3 /MeOH (v/v)=20:1) to give pure yellow solid (35 mg, 28.8% yield).
1 H-NMR (DMSO-d 6 ) δ (ppm): 0.86 (t, J=6.9 Hz, 3H, CH 2 C H 3 ), 2.42 (q, J=7.2 Hz, 2H, C H 2 CH 3 ), 3.15 (s, 3H, ArCH 3 ), 2.94-3.11 (m, 2H, NC H 2 CH 2 ), 3.84 (s, 3H, OCH 3 ), 3.88 (s, 3H, OCH 3 ), 3.97-4.01 (m, 1H, NC H 2 CH 2 ), 4.41-4.44 (m, 1H, NC H 2 CH 2 ), 6.03 (s, 1H, ArH), 6.26 (d, J=4.5 Hz, 2H, OCH 2 O), 6.67 (s, 1H, ArH), 7.23 (s, 1H, C═CH 2 ), 7.28 (d, J=9.0 Hz, 1H, ArH), 7.43 (s, 1H, C═CH 2 ), 7.52 (d, J=8.4 Hz, 1H, ArH).
Preparation of Compound 11
To a stirred solution of (±)-8-acetonyldihydrocoptisine (205 mg, 0.54 mmol) in anhydrous tetrahydrofuran (4 mL), HOAc (2 mL) and formaldehyde (1 mL, 10.04 mmol) was added dropwise. The reaction mixture was refluxed for 5 h. After the reaction completed, the reaction mixture was concentrated and added with 2 N HCl (2 mL), then stirred at room temperature for 1 h and extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was dried over anhydrous MgSO 4 and then filtered and then concentrated under reduced pressure to give crude product, which was purified via silica gel column chromatography (CHCl 3 /MeOH (v/v)=20:1) to give pure yellow solid (170 mg, 71.5% yield).
1 H-NMR (DMSO-d 6 ) δ: 2.60 (s, 3H, COCH 3 ), 2.91 (s, 3H, ArCH 3 ), 2.91-3.09 (m, 2H, NCH 2 C H 2 ), 4.39-4.48 (m, 2H, NC H 2 CH 2 ), 6.16 (s, 2H, OCH 2 O), 6.35 (d, J=10.5 Hz, 2H, OCH 2 O), 6.81 (s, 1H, C═CH 2 ), 7.15 (s, 1H, ArH), 7.16 (s, 1H, C═CH 2 ), 7.40 (s, 1H, ArH), 8.03 (m, 2H, ArH). MS (m/z): 402.1 [M-Cl] + .
Preparation of Compound 12
To a stirred solution of coptisine (105 mg, 0.30 mmol) in 5 N NaOH (1 ml), butanone (0.3 mL, 3.35 mmol) was added dropwise. The reaction mixture was stirred at 60° C. for 3 h and then the mixture was extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was washed to neutral with water, and dried over anhydrous MgSO 4 , and filtered, and then concentrated under reduced pressure to give intermediate product. The intermediate product was dissolved in anhydrous tetrahydrofuran (3 mL) followed by addition of HOAc (0.5 mL) and formaldehyde (0.6 mL, 6.02 mmol) dropwise. The reaction mixture was kept refluxing for 3 h. After the reaction completed, the reaction mixture was concentrated and added with 2 N HCl (2 mL), then stirred at room temperature for 1 h and extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was dried over anhydrous MgSO 4 and then filtered and concentrated under reduced pressure to give crude product, which was purified via silica gel column chromatography (CHCl 3 /MeOH(v/v)=20:1) to give pure yellow solid (43 mg, 32.3% yield).
1 H-NMR (CDCl 3 ) δ: 1.16 (t, J=7.2 Hz, 3H, CH 2 C H 3 ), 2.90 (s, 3H, ArCH 3 ), 3.05 (q, J=7.2 Hz, 2H, C H 2 CH 3 ), 3.13-3.32 (m, 2H, NCH 2 C H 2 ), 4.27-4.34 (m, 1H, NC H 2 CH 2 ), 4.90-4.98 (m, 1H, NC H 2 CH 2 ), 6.05 (d, J=2.1 Hz, 2H, OCH 2 O), 6.18 (s, 1H, OCH 2 O), 6.27 (s, 1H, OCH 2 O), 6.83 (s, 1H, ArH), 7.04 (s, 1H, ArH), 7.17 (s, 1H, C═CH 2 ), 7.24 (s, 1H, C═CH 2 ), 7.67 (d, J=9.0 Hz, 1H, ArH), 7.80 (d, J=9.0 Hz, 1H, ArH). MS (m/z): 416.1 [M-Cl] + .
Preparation of Compound 13
To a stirred solution of coptisine (300 mg, 0.84 mmol) in 5 N NaOH (1.5 ml), 2-pentanone (0.8 mL, 7.52 mmol) was added dropwise. The reaction mixture was stirred at 60° C. for 3 h. The reaction mixture was extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was washed to neutral with water, and dried over anhydrous MgSO 4 , and filtered, and then concentrated under reduced pressure to give intermediate product. The intermediate product was dissolved in anhydrous tetrahydrofuran (5 mL) followed by addition of HOAc (1 mL) and formaldehyde (1.5 mL, 15.06 mmol) dropwise. The reaction mixture was kept refluxing for 3 h. After the reaction completed, the reaction mixture was concentrated and added with 2 N HCl (2 mL), then stirred at room temperature for 1 h and extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was dried over anhydrous MgSO 4 and then filtered and concentrated under reduced pressure to give crude product, which was purified via silica gel column chromatography (CHCl 3 /MeOH (v/v)=20:1) to give pure yellow solid (130 mg, 33.1% yield).
1 H-NMR (CDCl 3 ) δ: 0.98 (t, J=7.2 Hz, 3H, CH 2 CH 2 C H 3 ), 1.71 (q, J=7.2 Hz, 2H, CH 2 C H 2 CH 3 ), 2.90 (s, 3H, ArCH 3 ), 2.90-3.01 (m, 2H, C H 2 CH 2 CH 3 ), 3.04-3.14 (m, 1H, NCH 2 C H 2 ), 3.28-3.36 (m, 1H, NCH 2 C H 2 ), 4.26-4.28 (m, 1H, NC H 2 CH 2 ), 4.94-5.01 (m, 1H, NC H 2 CH 2 ), 6.05 (br s, 2H, OCH 2 O), 6.16 (s, 1H, OCH 2 O), 6.27 (s, 1H, OCH 2 O), 6.82 (s, 1H, ArH), 7.03 (s, 1H, ArH), 7.15 (s, 1H, C═CH 2 ), 7.32 (s, 1H, C═CH 2 ), 7.66 (d, J=8.7 Hz, 1H, ArH), 7.80 (d, J=8.7 Hz, 1H, ArH). MS (m/z): 430.2 [M-Cl] + .
Preparation of Compound 14
To a stirred solution of coptisine (190 mg, 0.53 mmol) in 5 N NaOH (1 ml), 2-hexanone (0.5 mL, 4.04 mmol) was added dropwise. The reaction mixture was stirred at 60° C. for 3 h. The reaction mixture was extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was washed to neutral with water, and dried over anhydrous MgSO 4 , and filtered, and then concentrated under reduced pressure to give intermediate product. The intermediate product was dissolved in anhydrous tetrahydrofuran (4 mL) followed by addition of HOAc (1 mL) and formaldehyde (1 mL, 10.04 mmol) dropwise. The reaction mixture was kept refluxing for 3 h. After the reaction completed, the reaction mixture was concentrated and added with 2 N HCl (2 mL), then stirred at room temperature for 1 h and extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was dried over anhydrous MgSO 4 and then filtered and concentrated under reduced pressure to give crude product, which was purified via silica gel column chromatography (CHCl 3 /MeOH (v/v)=20:1) to give pure yellow solid (106 mg, 41.4% yield).
1 H-NMR (DMSO-d 6 ) δ: 0.91 (m, 3H, CH 2 CH 2 CH 2 C H 3 ), 1.36 (m, 2H, CH 2 CH 2 C H 2 CH 3 ), 1.58 (m, 2H, CH 2 C H 2 CH 2 CH 3 ), 2.91 (s, 3H, ArCH 3 ), 2.91-3.05 (m, 2H, C H 2 CH 2 CH 2 CH 3 ), 3.05-3.16 (m, 2H, NCH 2 C H 2 ), 4.22 (s, 2H, NC H 2 CH 2 ), 6.16 (s, 2H, OCH 2 O), 6.25 (s, 1H, OCH 2 O), 6.36 (s, 1H, OCH 2 O), 6.78 (s, 1H, C═CH 2 ), 7.14 (s, 1H, ArH), 7.19 (s, 1H, C═CH 2 ), 7.39 (s, 1H, ArH), 8.03 (s, 1H, ArH). MS (m/z): 444.2 (M-Cl) + .
Preparation of Compound 15
To a stirred solution of coptisine (300 mg, 0.84 mmol) in 5 N NaOH (1.5 ml), 2-heptanone (1 mL, 7.18 mmol) was added dropwise. The reaction mixture was stirred at 60° C. for 3 h. The reaction mixture was extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was washed to neutral with water, and dried over anhydrous MgSO 4 , and filtered, and then concentrated under reduced pressure to give intermediate product. The intermediate product was dissolved in anhydrous tetrahydrofuran (5 mL) followed by addition of HOAc (1 mL) and formaldehyde (1.5 mL, 15.06 mmol) dropwise. The reaction mixture was kept refluxing for 3 h. After the reaction completed, the reaction mixture was concentrated and added with 2 N HCl (2 mL), then stirred at room temperature for 1 h and extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was dried over anhydrous MgSO 4 and then filtered and concentrated under reduced pressure to give crude product, which was purified via silica gel column chromatography (CHCl 3 /MeOH (v/v)=20:1) to give pure yellow solid (97 mg, 23.3% yield).
1 H-NMR (DMSO-d 6 ) δ: 0.91 (br s, 3H, CH 2 CH 2 (CH 2 ) 2 C H 3 ), 1.33-1.35 (m, 4H, CH 2 CH 2 (C H 2 ) 2 CH 3 ), 1.58-1.61 (m, 2H, CH 2 C H 2 (CH 2 ) 2 CH 3 ), 2.93 (s, 3H, ArCH 3 ), 2.93-3.14 (m, 4H, C H 2 CH 2 (CH 2 ) 2 CH 3 , NCH 2 C H 2 ), 4.45 (br s, 2H, NC H 2 CH 2 ), 6.18 (s, 2H, OCH 2 O), 6.29 (s, 1H, OCH 2 O), 6.40 (s, 1H, OCH 2 O), 6.79 (s, 1H, C═CH 2 ), 7.16 (s, 1H, ArH), 7.19 (s, 1H, C═CH 2 ), 7.42 (s, 1H, ArH), 8.05 (s, 2H, ArH). MS (m/z): 458.2 (M-Cl) + .
Preparation of Compound 16
To a stirred solution of coptisine (200 mg, 0.56 mmol) in 5 N NaOH (1 ml), 2-octanone (1 mL, 6.26 mmol) was added dropwise. The reaction mixture was stirred at 60° C. for 3 h. The reaction mixture was extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was washed to neutral with water, and dried over anhydrous MgSO 4 , and filtered, and then concentrated under reduced pressure to give intermediate product. The intermediate product was dissolved in anhydrous tetrahydrofuran (4 mL) followed by addition of HOAc (0.5 mL) and formaldehyde (1 mL, 10.04 mmol) dropwise. The reaction mixture was kept refluxing for 3 h. After the reaction completed, the reaction mixture was concentrated and added with 2 N HCl (2 mL), then stirred at room temperature for 1 h and extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was dried over anhydrous MgSO 4 and then filtered and concentrated under reduced pressure to give crude product, which was purified via silica gel column chromatography (CHCl 3 /MeOH (v/v)=20:1) to give pure yellow solid. (65 mg, 22.8% yield)
1 H-NMR (DMSO-d 6 ) δ: 0.88 (br s, 3H, CH 2 CH 2 (CH 2 ) 3 C H 3 ), 1.31 (br s, 6H, CH 2 CH 2 (C H 2 ) 3 CH 3 ), 1.58-1.60 (m, 2H, CH 2 C H 2 (CH 2 ) 3 CH 3 ), 2.73-3.15 (m, 4H, C H 2 CH 2 (CH 2 ) 3 CH 3 , NCH 2 C H 2 ), 2.93 (s, 3H, ArCH 3 ), 4.45 (br s, 2H, NC H 2 CH 2 ), 6.18 (s, 2H, OCH 2 O), 6.29 (s, 1H, OCH 2 O), 6.40 (s, 1H, OCH 2 O), 6.78 (s, 1H, C═CH 2 ), 7.16 (s, 1H, ArH), 7.19 (s, 1H, C═CH 2 ), 7.42 (s, 1H, ArH), 8.05 (s, 2H, ArH).
Preparation of Compound 17
To a stirred solution of coptisine (100 mg, 0.28 mmol) in 5 N NaOH (1 ml), 2-nonanone (0.5 mL, 2.91 mmol) was added dropwise. The reaction mixture was stirred at 60° C. for 3 h. The reaction mixture was extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was washed to neutral with water, and dried over anhydrous MgSO 4 , and filtered, and then concentrated under reduced pressure to give intermediate product. The intermediate product was dissolved in anhydrous tetrahydrofuran (3 mL) followed by addition of HOAc (0.5 mL) and formaldehyde (0.6 mL, 6.02 mmol) dropwise. The reaction mixture was kept refluxing for 3 h. After the reaction completed, the reaction mixture was concentrated and added with 2 N HCl (2 mL), then stirred at room temperature for 1 h and extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was dried over anhydrous MgSO 4 and then filtered and concentrated under reduced pressure to give crude product, which was purified via silica gel column chromatography (CHCl 3 /MeOH (v/v)=20:1) to give pure yellow solid (30 mg, 20.4% yield).
1 H-NMR (DMSO-d 6 ) δ: 0.87 (br s, 3H, CH 2 CH 2 (CH 2 ) 4 C H 3 ), 1.28-1.31 (m, 8H, CH 2 CH 2 (C H 2 ) 4 CH 3 ), 1.58-1.61 (m, 2H, CH 2 C H 2 (CH 2 ) 4 C 3 ), 2.83-3.15 (m, 4H, C H 2 CH 2 (CH 2 ) 4 CH 3 , NCH 2 C H 2 ), 2.93 (s, 3H, ArCH 3 ), 4.45 (br s, 2H, NC H 2 CH 2 ), 6.18 (s, 2H, OCH 2 O), 6.29 (s, 1H, OCH 2 O), 6.40 (s, 1H, OCH 2 O), 6.78 (s, 1H, C═CH 2 ), 7.16 (s, 1H, ArH), 7.19 (s, 1H, C═CH 2 ), 7.42 (s, 1H, ArH), 8.05 (s, 2H, ArH).
Preparation of Compound 18
To a stirred solution of coptisine (200 mg, 0.56 mmol) in 5 N NaOH (1 ml), 2-decanone (1 mL, 5.28 mmol) was added dropwise. The reaction mixture was stirred at 60° C. for 3 h. The reaction mixture was extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was washed to neutral with water, and dried over anhydrous MgSO 4 , and filtered, and then concentrated under reduced pressure to give intermediate product. The intermediate product was dissolved in anhydrous tetrahydrofuran (4 mL) followed by addition of HOAc (0.5 mL) and formaldehyde (1 mL, 10.04 mmol) dropwise. The reaction mixture was kept refluxing for 3 h. After the reaction completed, the reaction mixture was concentrated and added with 2 N HCl (2 mL), then stirred at room temperature for 1 h and extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was dried over anhydrous MgSO 4 and then filtered and concentrated under reduced pressure to give crude product, which was purified via silica gel column chromatography (CHCl 3 /MeOH (v/v)=20:1) to give pure yellow solid (59 mg, 19.6% yield).
1 H-NMR (DMSO-d 6 ) δ: 0.88 (t, J=9.0 Hz, 3H, CH 2 CH 2 (CH 2 ) 5 C H 3 ), 1.27 (br s, 10H, CH 2 CH 2 (C H 2 ) 5 CH 3 ), 1.58-1.61 (m, 2H, CH 2 C H 2 (CH 2 ) 5 CH 3 ), 2.93 (s, 3H, ArCH 3 ), 2.93-3.15 (m, 4H, C H 2 CH 2 (CH 2 ) 5 CH 3 , NCH 2 C H 2 ), 4.45 (br s, 2H, NC H 2 CH 2 ), 6.18 (br s, 2H, OCH 2 O), 6.29 (s, 1H, OCH 2 O), 6.40 (s, 1H, OCH 2 O), 6.79 (s, 1H, C═CH 2 ), 7.16 (s, 1H, ArH), 7.19 (s, 1H, C═CH 2 ), 7.42 (s, 1H, ArH), 8.05 (s, 2H, ArH).
Preparation of Compound 19
To a stirred solution of coptisine (200 mg, 0.56 mmol) in 5 N NaOH (1 ml), 2-undecanone (1 mL, 4.87 mmol) was added dropwise. The reaction mixture was stirred at 60° C. for 3 h. The reaction mixture was extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was washed to neutral with water, and dried over anhydrous MgSO 4 , and filtered, and then concentrated under reduced pressure to give intermediate product. The intermediate product was dissolved in anhydrous tetrahydrofuran (4 mL) followed by addition of HOAc (0.5 mL) and formaldehyde (1 mL, 10.04 mmol) dropwise. The reaction mixture was kept refluxing for 3 h. After the reaction completed, the reaction mixture was concentrated and added with 2 N HCl (2 mL), then stirred at room temperature for 1 h and extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was dried over anhydrous MgSO 4 and then filtered and concentrated under reduced pressure to give crude product, which was purified via silica gel column chromatography (CHCl 3 /MeOH (v/v)=20:1) to give pure yellow solid (55 mg, 17.8% yield).
1 H-NMR (DMSO-d 6 ) δ: 0.86 (t, J=6.6 Hz, 3H, CH 2 CH 2 (CH 2 ) 6 C H 3 ), 1.26-1.31 (m, 12H, CH 2 CH 2 (C H 2 ) 6 CH 3 ), 1.58-1.60 (m, 2H, CH 2 C H 2 (CH 2 ) 6 CH 3 ), 2.93 (s, 3H, ArCH 3 ), 2.93-3.14 (m, 4H, C H 2 CH 2 (CH 2 ) 6 CH 3 , NCH 2 C H 2 ), 4.45 (br s, 2H, NC H 2 CH 2 ), 6.18 (br s, 2H, OCH 2 O), 6.29 (s, 1H, OCH 2 O), 6.40 (s, 1H, OCH 2 O), 6.78 (s, 1H, C═CH 2 ), 7.16 (s, 1H, ArH), 7.18 (s, 1H, C═CH 2 ), 7.42 (s, 1H, ArH), 8.05 (s, 2H, ArH).
Preparation of Compound 20
To a stirred solution of coptisine (230 mg, 0.65 mmol) in 5 N NaOH (1 ml), methoxyacetophenone (780 mg, 5.19 mmol) was added slowly. The reaction mixture was stirred at 60° C. for 3 h. The reaction mixture was extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was washed to neutral with water, and dried over anhydrous MgSO 4 , and filtered, and then concentrated under reduced pressure to give intermediate product. The intermediate product was dissolved in anhydrous tetrahydrofuran (4 mL) followed by addition of HOAc (0.5 mL) and formaldehyde (1 mL, 10.04 mmol) dropwise. The reaction mixture was kept refluxing for 3 h. After the reaction completed, the reaction mixture was concentrated and added with 2 N HCl (2 mL), then stirred at room temperature for 1 h and extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was dried over anhydrous MgSO 4 and then filtered and concentrated under reduced pressure to give crude product, which was purified via silica gel column chromatography (CHCl 3 /MeOH (v/v)=20:1) to give pure yellow solid (140 mg, 41.0% yield).
1 H-NMR (DMSO-d 6 ) δ: 2.94 (s, 3H, OCH 3 ), 2.94-3.13 (m, 2H, NCH 2 C H 2 ), 3.89 (s, 3H, ArCH 3 ), 4.54 (br s, 2H, NC H 2 CH 2 ), 6.17 (s, 2H, OCH 2 O), 6.19 (s, 1H, OCH 2 O), 6.43 (s, 1H, OCH 2 O), 6.83 (s, 1H, C═CH 2 ), 6.97 (s, 1H, C═CH 2 ), 7.15 (d, J=9.0 Hz, 2H, ArH), 7.16 (s, 1H, ArH), 7.42 (s, 1H, ArH), 7.97 (d, J=8.7 Hz, 2H, ArH), 8.06 (m, 2H, ArH). MS (m/z): 494.2 (M-Cl) + .
Preparation of Compound 21
To a stirred solution of coptisine (100 mg, 0.28 mmol) in 5 N NaOH (1 ml), 1-acetonaphthone (0.5 mL, 3.28 mmol) was added dropwise. The reaction mixture was stirred at 60° C. for 3 h. The reaction mixture was extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was washed to neutral with water, and dried over anhydrous MgSO 4 , and filtered, and then concentrated under reduced pressure to give intermediate product. The intermediate product was dissolved in anhydrous tetrahydrofuran (3 mL) followed by addition of HOAc (0.5 mL) and formaldehyde (0.6 mL, 6.02 mmol) dropwise. The reaction mixture was kept refluxing for 3 h. After the reaction completed, the reaction mixture was concentrated and added with 2 N HCl (2 mL), then stirred at room temperature for 1 h and extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was dried over anhydrous MgSO 4 and then filtered and concentrated under reduced pressure to give crude product, which was purified via silica gel column chromatography (CHCl 3 /MeOH (v/v)=20:1) to give pure yellow solid (34 mg, 22.1% yield).
1 H-NMR (DMSO-d 6 ) δ: 2.98 (s, 3H, ArCH 3 ), 3.10-3.20 (m, 2H, NCH 2 C H 2 ), 4.57-4.78 (m, 2H, NC H 2 CH 2 ), 6.18 (s, 2H, OCH 2 O), 6.44 (d, J=9.9 Hz, 2H, OCH 2 O), 6.82 (s, 1H, C═CH 2 ), 7.08 (s, 1H, C═CH 2 ), 7.20 (s, 1H, ArH), 7.460 (s, 1H, ArH), 7.64-7.76 (m, 2H, ArH), 8.04-8.14 (m, 4H, ArH), 8.24 (d, J=8.4 Hz, 1H, ArH).
Preparation of Compound 22
To a stirred solution of coptisine (250 mg, 0.70 mmol) in 5 N NaOH (1 ml), 6-acetyl-1,4-benzodioxane (1 mL, 6.67 mmol) was added slowly. The reaction mixture was stirred at 60° C. for 3 h. The reaction mixture was extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was washed to neutral with water, and dried over anhydrous MgSO 4 , and filtered, and then concentrated under reduced pressure to give intermediate product. The intermediate product was dissolved in anhydrous tetrahydrofuran (5 mL) followed by addition of HOAc (0.5 mL) and formaldehyde (1.5 mL, 15.06 mmol) dropwise. The reaction mixture was kept refluxing for 3 h. After the reaction completed, the reaction mixture was concentrated and added with 2 N HCl (2 mL), then stirred at room temperature for 1 h and extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was dried over anhydrous MgSO 4 and then filtered and concentrated under reduced pressure to give crude product, which was purified via silica gel column chromatography (CHCl 3 /MeOH (v/v)=20:1) to give pure yellow solid (110 mg, 28.1% yield).
1 H-NMR (DMSO-d 6 ) δ: 2.95 (s, 3H, ArCH 3 ), 2.99-3.14 (m, 2H, NCH 2 C H 2 ), 4.37 (br d, J=9.0 Hz, 4H, OCH 2 CH 2 O), 4.54 (br s, 2H, NC H 2 CH 2 ), 6.19 (s, 2H, OCH 2 O), 6.24 (s, 1H, OCH 2 O), 6.44 (s, 1H, OCH 2 O), 6.86 (s, 1H, C═CH 2 ), 6.99 (s, 1H, C═CH 2 ), 7.10 (d, J=8.4 Hz, 1H, ArH), 7.17 (s, 1H, ArH), 7.44 (s, 1H, ArH), 7.45 (d, J=2.1 Hz, 2H, ArH), 7.54 (dd, J 1 =8.4 Hz, J 2 =2.1 Hz, 1H, ArH), 8.07 (s, 2H, ArH).
Preparation of Compound 23
To a stirred solution of coptisine (200 mg, 0.56 mmol) in 5 N NaOH (1 ml), 4-isobutylacetophenone (1 mL, 5.40 mmol) was added dropwise. The reaction mixture was stirred at 60° C. for 3 h. The reaction mixture was extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was washed to neutral with water, and dried over anhydrous MgSO 4 , and filtered, and then concentrated under reduced pressure to give intermediate product. The intermediate product was dissolved in anhydrous tetrahydrofuran (4 mL) followed by addition of HOAc (0.5 mL) and formaldehyde (1 mL, 10.04 mmol) dropwise. The reaction mixture was kept refluxing for 3 h. After the reaction completed, the reaction mixture was concentrated and added with 2 N HCl (2 mL), then stirred at room temperature for 1 h and extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was dried over anhydrous MgSO 4 and then filtered and concentrated under reduced pressure to give crude product, which was purified via silica gel column chromatography (CHCl 3 /MeOH (v/v)=20:1) to give pure yellow solid (117 mg, 37.4% yield).
1 H-NMR (DMSO-d 6 ) δ: 0.92 (d, J=6.6 Hz, 6H, CH 2 CH(C H 3 ) 2 ), 1.89-1.96 (m, 1H, CH 2 C H (CH 3 ) 2 ), 2.60 (d, J=6.9 Hz, 2H, C H 2 CH(CH 3 ) 2 ), 2.96 (s, 3H, ArCH 3 ), 2.99-3.14 (m, 2H, NCH 2 C H 2 ), 4.56 (br s, 2H, NC H 2 CH 2 ), 6.19 (br s, 2H, OCH 2 O), 6.25 (s, 1H, OCH 2 O), 6.45 (s, 1H, OCH 2 O), 6.87 (s, 1H, C═CH 2 ), 7.03 (s, 1H, C═CH 2 ), 7.18 (s, 1H, ArH), 7.43 (d, J=7.5 Hz, 2H, ArH), 7.44 (s, 1H, ArH), 7.89 (d, J=7.5 Hz, 2H, ArH), 8.05 (s, 2H, ArH).
Preparation of Compound 24
To a stirred solution of coptisine (250 mg, 0.70 mmol) in 5 N NaOH (1 ml), acetophenone (0.8 mL, 6.85 mmol) was added slowly. The reaction mixture was stirred at 60° C. for 3 h. The reaction mixture was extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was washed to neutral with water, and dried over anhydrous MgSO 4 , and filtered, and then concentrated under reduced pressure to give intermediate product. The intermediate product was dissolved in anhydrous tetrahydrofuran (5 mL) followed by addition of HOAc (0.5 mL) and formaldehyde (1.5 mL, 15.06 mmol) dropwise. The reaction mixture was kept refluxing for 3 h. After the reaction completed, the reaction mixture was concentrated and added with 2 N HCl (2 mL), then stirred at room temperature for 1 h and extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was dried over anhydrous MgSO 4 and then filtered and concentrated under reduced pressure to give crude product, which was purified via silica gel column chromatography (CHCl 3 /MeOH (v/v)=20:1) to give pure deep yellow solid (120 mg, 34.3% yield).
1 H-NMR (DMSO-d 6 ) δ (ppm): 2.96 (s, 3H, ArCH 3 ), 2.96-3.15 (m, 2H, NCH 2 C H 2 ), 4.58 (br s, 2H, NC H 2 CH 2 ), 6.19 (s, 2H, OCH 2 O), 6.26 (s, 1H, OCH 2 O), 6.46 (s, 1H, OCH 2 O), 6.88 (s, 1H, C═CH 2 ), 7.07 (s, 1H, C═CH 2 ), 7.18 (s, 1H, ArH), 7.45 (s, 1H, ArH), 7.62-7.67 (m, 2H, ArH), 7.76 (t, J=7.2 Hz, 1H, ArH), 7.96 (d, J=7.8 Hz, 2H, ArH), 8.08 (m, 2H, ArH).
Preparation of Compound 25
To a stirred solution of coptisine (100 mg, 0.28 mmol) in 5 N NaOH (0.8 ml), pinacotone (0.2 mL, 1.60 mmol) was added dropwise. The reaction mixture was stirred at 60° C. for 3 h. The reaction mixture was extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was washed to neutral with water, and dried over anhydrous MgSO 4 , and filtered, and then concentrated under reduced pressure to give intermediate product. The intermediate product was dissolved in anhydrous tetrahydrofuran (4 mL) followed by addition of HOAc (0.3 mL) and formaldehyde (0.3 mL, 3.01 mmol) dropwise. The reaction mixture was kept refluxing for 1 h. After the reaction completed, the reaction mixture was concentrated and added with 2 N HCl (1.5 mL), then stirred at room temperature for 1 h and extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was dried over anhydrous MgSO 4 and then filtered and concentrated under reduced pressure to give crude product, which was purified via silica gel column chromatography (CHCl 3 /MeOH (v/v)=20:1) to give pure yellow solid (30 mg, 22.2% yield).
1 H-NMR (CDCl 3 ) δ (ppm): 1.48 (s, 9H, 3CH 3 ), 2.92 (s, 3H, ArCH 3 ), 2.96-2.99 (m, 1H, NCH 2 C H 2 ), 3.42-3.49 (m, 1H, NCH 2 C H 2 ), 4.09-4.15 (m, 1H, NC H 2 CH 2 ), 5.08-5.14 (m, 1H, NC H 2 CH 2 ), 6.07-6.09 (m, 2H, OCH 2 O), 6.20 (s, 1H, OCH 2 O), 6.29 (s, 1H, OCH 2 O), 6.84 (s, 1H, ArH), 7.06 (s, 1H, ArH), 7.23 (s, 1H, C═CH 2 ), 7.64 (s, 1H, C═CH 2 ), 7.67 (d, J=9.0 Hz, 1H, ArH), 7.80 (d, J=9.0 Hz, 1H, ArH). MS (m/z): 444.2 (M-Cl) + .
Preparation of Compound 26
To a stirred solution of coptisine (300 mg, 0.84 mmol) in 5 N NaOH (1.5 ml), 3-methyl-2-butanone (0.5 mL, 4.70 mmol) was added dropwise. The reaction mixture was stirred at 60° C. for 3 h. The reaction mixture was extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was washed to neutral with water, and dried over anhydrous MgSO 4 , and filtered, and then concentrated under reduced pressure to give intermediate product. The intermediate product was dissolved in anhydrous tetrahydrofuran (5 mL) followed by addition of HOAc (1.2 mL) and formaldehyde (1 mL, 10.04 mmol) dropwise. The reaction mixture was kept refluxing for 1 h. After the reaction completed, the reaction mixture was concentrated and added with 2 N HCl (2.5 mL), then stirred at room temperature for 1 h and extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was dried over anhydrous MgSO 4 and then filtered and concentrated under reduced pressure to give crude product, which was purified via silica gel column chromatography (CHCl 3 /MeOH (v/v)=20:1) to give pure yellow solid (140 mg, 35.6% yield).
1 H-NMR (DMSO-d 6 ) δ (ppm): 1.16-1.20 (m, 6H, 2CH 3 ), 2.92 (s, 3H, ArCH 3 ), 2.87-3.10 (m, 2H, NCH 2 C H 2 ), 3.67-3.76 (m, 1H, COCH), 4.27-4.50 (m, 2H, NC H 2 CH 2 ), 6.17 (s, 2H, OCH 2 O), 6.31 (s, 1H, OCH 2 O), 6.39 (s, 1H, OCH 2 O), 6.85 (s, 1H, C═CH 2 ), 7.15 (s, 1H, ArH), 7.28 (s, 1H, C═CH 2 ), 7.41 (s, 1H, ArH), 8.04 (s, 2H, ArH). MS (m/z): 430.2 (M-Cl) + .
Preparation of Compound 27
To a stirred solution of coptisine (300 mg, 0.84 mmol) in 5N NaOH (1.5 ml), methyl cyclopropyl ketone (0.4 mL, 4.27 mmol) was added dropwise. The reaction mixture was stirred at 60° C. for 3 h. The reaction mixture was extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was washed to neutral with water, and dried over anhydrous MgSO 4 , and filtered, and then concentrated under reduced pressure to give intermediate product. The intermediate product was dissolved in anhydrous tetrahydrofuran (5 mL) followed by addition of HOAc (1.2 mL) and formaldehyde (1 mL, 10.04 mmol) dropwise. The reaction mixture was kept refluxing for 1 h. After the reaction completed, the reaction mixture was concentrated and added with 2 N HCl (2.5 mL), then stirred at room temperature for 1 h and extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was dried over anhydrous MgSO 4 and then filtered and concentrated under reduced pressure to give crude product, which was purified via silica gel column chromatography (CHCl 3 /MeOH (v/v)=20:1) to give pure yellow solid (204 mg, 52.1% yield).
1 H-NMR (DMSO-d 6 ) δ (ppm): 1.03-1.13 (m, 4H, 2CH 2 ), 2.93 (s, 3H, ArCH 3 ), 2.93-3.12 (m, 3H, NCH 2 C H 2 , COCH), 4.42-4.46 (m, 2H, NC H 2 CH 2 ), 6.18 (s, 2H, OCH 2 O), 6.33 (s, 1H, OCH 2 O), 6.44 (s, 1H, OCH 2 O), 6.85 (s, 1H, C═CH 2 ), 7.16 (s, 1H, ArH), 7.39 (s, 1H, C═CH 2 ), 7.41 (s, 1H, ArH), 8.05 (s, 2H, ArH). MS (m/z): 428.2 (M-Cl) + .
Preparation of Compound 28
To a stirred solution of coptisine (300 mg, 0.84 mmol) in 5N NaOH (1.5 ml), methyl cyclohexyl ketone (0.6 mL, 4.37 mmol) was added dropwise. The reaction mixture was stirred at 60° C. for 3 h. The reaction mixture was extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was washed to neutral with water, and dried over anhydrous MgSO 4 , and filtered, and then concentrated under reduced pressure to give the intermediate product. The intermediate product was dissolved in anhydrous tetrahydrofuran (5 mL) followed by addition of HOAc (1.2 mL) and formaldehyde (1 mL, 10.04 mmol) dropwise. The reaction mixture was kept refluxing for 1 h. After the reaction finished, the reaction mixture was concentrated and added with 2 N HCl (2.5 mL), then stirred at room temperature for 1 h and extracted with CHCl 3 /MeOH (v/v=10:1). The organic layer was dried over anhydrous MgSO 4 and then filtered and concentrated under reduced pressure to give crude product, which was purified via silica gel column chromatography (CHCl 3 /MeOH (v/v)=20:1) to give pure yellow solid (105 mg, 24.7% yield).
1 H-NMR (DMSO-d 6 ) δ (ppm): 1.14-1.95 (m, 10H, 5CH 2 ), 2.85-3.14 (m, 2H, NCH 2 C H 2 ), 2.91 (s, 3H, ArCH 3 ), 3.44-3.51 (m, 1H, COCH), 4.23-4.49 (m, 2H, NC H 2 CH 2 ), 6.16 (s, 2H, OCH 2 O), 6.29 (s, 1H, OCH 2 O), 6.38 (s, 1H, OCH 2 O), 6.82 (s, 1H, C═CH 2 ), 7.14 (s, 1H, ArH), 7.28 (s, 1H, C═CH 2 ), 7.40 (s, 1H, ArH), 8.03 (s, 2H, ArH). MS (m/z): 470.2 (M-Cl) + .
Preparation of Compound 29
To a stirred solution of 13-methylcoptisine (41 mg, 0.11 mmol) and K 2 CO 3 (45 mg, 0.33 mmol) in methanol (4 mL), 5% NaOH solution (0.5 mL) containing NaBH 4 (6 mg, 0.16 mmol) was added dropwise. The reaction mixture was stirred at room temperature for 2 h until the reaction completed and the precipitated product was filtered, washed to neutral with water and then dried to give yellow solid (28 mg, 75.7% yield).
1 H-NMR (DMSO-d 6 ) δ (ppm): 2.15 (s, 3H, ArCH 3 ), 2.68 (br s, 2H, NCH 2 CH 2 ), 3.03 (br s, 2H, NCH 2 CH 2 ), 4.14 (s, 2H, NCH 2 Ar), 6.00 (s, 2H, OCH 2 O), 6.03 (s, 2H, OCH 2 O), 6.64 (d, J=8.1 Hz, 1H, ArH), 6.77 (d, J=8.1 Hz, 1H, ArH), 6.84 (s, 1H, ArH), 7.03 (s, 1H, ArH).
Pharmacological Experiment 1
Example of Bioresearch on Compounds for Anti-UC
1. Cytotoxicity Assay of Compounds
(1) Method: Intestinal epithelial cell IEC-6 at high confluence (>90%) were digested with 0.25% trypsin/0.1% EDTA and then seeded in a 96-well plate at a density of 2×10 3 /well. The next day the medium was discarded and cultivated with testcompounds at 1×10 −5 mol/L. The cytotoxicity was measured by MTT assay (n=5) at 0 h, 24 h, and 72 h after co-culture of IEC-6 cells and test compounds.
(2) Results: During the test, 1×10 −5 mol/L test compounds according to the present invention did not show significant cytotoxicity on IEC-6 cell. There was no significant difference statistically ( FIG. 1 ).
(3) Conclusion: A series of protoberberine alkaloid derivatives or its physiologically acceptable salts according to the present invention are suitable for screening downstream experiment with IEC-6 cell model.
The cytotoxicity test results on IEC-6 cell model of protoberberine alkaloid derivatives or their physiologically acceptable salts according to the present invention at 1 uM are shown in FIG. 1 . It is shown that, in addition to the compounds 16-19 and 21, the other test compounds have no significant cytotoxicity when incubated with IEC-6 cells for 24 h at this concentration. The result after 3 days is the same as that after 24 h (data not shown here) and does not show significant cytotoxicity.
2. Transcriptional Activation Effect on pGL3-pxbp1 of 24 Test Compounds with No Obvious Cytotoxity on IEC-6 Cell
(1) Method: IEC-6 cells in the period of vigorous growth were seed in 48 well plate at a density of 5×10 4 to disperse the cells uniform and then it was placed in a humidifying cell incubator filled with 5% CO 2 at 37° C. to incubate. Plasmid transfection (0.6 μg/well) was carried out when the cells confluencing up to 70%-80%. After 4 h, each compound of 1×10 −5 mol/L was added into these wells (n=3), respectively, and incubated for another 36 h-48 h together with existing transfected cells. Luciferase activity detection on test samples was proceeded using dual luciferase report gene detection kit (Promega, USA).
(2) Results: According to the statistical analysis, 24 test compounds were found to show transcriptional activation effect on the xbp1 upstream promoter as compared with controls (with non-transfected plasmid cells as control group 1, and transfected cells by pGL-xbp1 without compound as control group 2).
(3) Conclusion: The protoberberine alkaloid derivatives or their physiologically acceptable salts according to the present invention show transcription activation effect on the expression of xbp1 gene.
The experimental results are shown in FIG. 2 .
Different test compounds have certain transcriptional activation effect on xbp1 gene promoter. In FIG. 2 , con 1 is used as background and con 2 is pGL3 empty vector control. The results show that these new compounds can activate the transcription of xbp1 molecule to varying degrees, and thus have certain transcriptional activation effect.
3. Determination of EC 50 Values of Compounds 1, 2, 7, and 10
(1) Method: IEC-6 cells in the period of logarithmic phase were seed in 48 well plate at a density of 5×10 4 to disperse the cells uniform and then it was placed in a humidifying cell incubator filled with 5% CO 2 at 37° C. to incubate. Plasmid transfection (0.6 μg/well) was carried out when the cells confluencing up to 70%-80%. After 4 h, different concentrations of compounds 1, 2, 7, and 10 were added (n=3), respectively, and incubated for another 36 h-48 h together with existing transfected cells. Luciferase activity detection on test samples was proceeded using dual luciferase report gene detection kit (Promega, USA).
(2) Results: The experimental results are shown in FIGS. 3-6 .
4. In vivo Test Results of Compound 7
(1) Method: In vivo test was carried out according to the literature: Y. Yoshioka, H. Akiyama, M. Nakano, T. Shoji, T. Kanda, Y. Ohtake, T. Takita, R. Matsuda, T. Maitani. Orally administered apple procyanidins protect against experimental inflammatory bowel disease in mice, international immunopharmacology, 2008, 1802-1807.
(2) Results and conclusions: Compound 7 has preliminary therapeutic effect on acute UC SD rats induced by acetic acid in vivo.
{circle around (1)} Compound 7 can reduce the weight loss in SD rats suffering from UC induced by acetic acid ( FIG. 7 ).
As shown in FIG. 7 , compared to the normal control group (blue curve), body weight of the model group (red curve) is decreased significantly (**P<0.01); compound 7 group (300 mg/kg) (green curve) can reduce the weight loss of the animals when compared to the model group (red curve) (#p<0.05, ##p<0.01). These test results show that compound 7 of 300 mg/kg can reduce the weight loss of SD rats suffering from UC to a certain extent. Comparing with the case before administration, the body weight change value of each group is: for the normal control group it is increased by 5.6%; for the model group it is decreased by 19.2%; and for compound 7 group it is decreased by 10%.
Compound 7 (300 mg/kg) can improve the inflammatory damage on SD rats suffering from UC induced by acetic acid ( FIG. 8 ).
As shown in FIG. 8 , for the normal control group it is observed that there is visible smooth intestinal wall and proper film tension, with mucosa without edema, hemorrhage, and obvious ulcer and that the histopathological examination shows that the structure in each layer of colon is normal without inflammatory change. While for the model group, severe swell can be seen in intestinal wall of colon tissue with obvious hemorrhage and exudation, and about 1 cm diameter ulcer is also seen in mucous layer (white arrow), the pathological section shows typical inflammatory characters with structure damage in each layer of colonic tissue. For drug groups, both the macroscopic and the histopathological results show that compound 7 has good therapeutic effect on UC, with inflammatory edema and hemorrhage being significantly reduced, and the intestinal epithelial cells even returning to normal alignment and regular polarity.
{circle around (2)} Effect of compound 7 on disease activity index (DAI) and macroscopic score of colon tissue in SD rats with acetic acid-induced UC (see Table 1).
Disease activity index (DAI) is evaluated by weight loss, shape of stool, hematochezia, and other indicators; macroscopic score of colon tissue is evaluated by intestinal mucosal hyperemia, edema of intestinal wall, ulcer size, and other indicators. The lower the DAI and macroscopic score is, the more close to the normal physiological state. In Table 1: **p<0.01 when compared with the normal control group; ##p<0.01 when compared with the model group.
TABLE 1
Effect of different groups on DAI and macroscopic score of
colon tissue in SD rats with acetic acid-induced UC
macroscopic
Groups
n (start/end)
DAI
score
Normal control group
6/6
0.00 ± 0.00
0.12 ± 0.00
Model group (acetic
6/6
3.15 ± 0.45**
0.12 ± 0.00
acid-induced)
Compound 7 group
6/6
1.15 ± 0.22##
2.05 ± 0.45##
(300 mg/kg)
{circle around (4)} Compound 7 can efficiently reduce the weight loss in C57/blc mice with DSS-induced UC in a good dose-dependent manner (see Table 2).
In Table 2, **p<0.01 when compared with the normal control group; ##p<0.01 when compared with the model group. The inhibitory effect of compound 7 of high dose (HD) group on the weight loss of experimental animal is even more prominent than that of the clinical conventional drug SASP for treating UC.
TABLE 2
The therapeutic effect of compound 7 on C57/blc mice with
DSS-induced acute UC in vivo
Body weight
Change
n (start/
(g) x ± SD
of body
Groups
end)
start
end
weight (%)
Normal control
10/10
23.02 ± 1.2
24.43 ± 0.8
↑ 6.14
group
Model group
10/10
23.83 ± 1.3
17.51 ± 2.1
↓ 26.52**
(DSS-induced)
SASP group
10/10
23.83 ± 2.3
20.09 ± 0.9
↓ 15.69##
(300 mg/kg)
Compound 7 HD
10/10
24.16 ± 1.1
21.57 ± 1.5
↓ 10.76##
group (500 mg/kg)
Compound 7 MD*
10/10
24.16 ± 1.3
20.54 ± 2.1
↓ 15.15##
group (250 mg/kg)
*MD: Medium dose group.
{circle around (5)} Compound 7 can improve the colon damage of C57/blc mice with DSS-induced UC in a dose-dependent manner (colon histopathology, HE×200) ( FIG. 9 ).
As shown in FIG. 9 , “a” represents the normal control group, “b” represents DSS model group, “c” represents positive drug SASP group, “d” represents compound 7 in HD group (500 mg/kg), “e” represents compound 7 in MD group (250 mg/kg), and “f” represents compound 7 in low dose (LD) group (125 mg/kg). Comparing with the normal control group (a), it is observed that the basic structure of intestinal epithelial cells is completely lost in the DSS model group (b) with obvious inflammatory edema, mucosa exfoliation with severe congestion and hemorrhage, infiltration of inflammatory cell into the muscular layer, and destroyed structure of muscle layer, which proves that the model is successful. Comparing with the DSS model group (b), positive drug SASP group (c) shows the improvement of visible colitis lesions and partial recovery of structure of each layer. While for the compound 7 in HD group (d), the lesion of inflammatory bowel diseases is more significantly improved, the intestinal epithelial cells arrange regularly, and the polarity arrangement of intestinal epithelial cells can even return to the normal physiological state. Moreover for the compound 7 in MD group (e) and in LD group (f), the inflammatory lesions of colon tissue also has a partial remission with a certain dose-effect relationship.
{circle around (6)} Effect of compound 7 on DAI and macroscopic score of colon tissue in C57/blc mice with DSS-induced UC (see Table 3).
DAI is evaluated by weight loss, shape of stool, hematochezia, and other indicators; macroscopic score of colon tissue is evaluated by intestinal mucosal hyperemia, edema of intestinal wall, ulcer size, and other indicators. The lower the DAI and macroscopic score is, the more close to the physiological state of the normal animal. In Table 3: **p<0.01 when compared with the normal control group; ##p<0.01 when compared with the model group.
TABLE 3
Effect of compound 7 on DAI and macroscopic score of
colon tissue in C57/blc mice with DSS-induced UC
macroscopic
score
Groups
n (start/end)
DAI
of colon tissue
Normal control group
10/10
0.00 ± 0.00
0.15 ± 0.01
Model group
10/10
3.33 ± 0.54**
5.54 ± 1.23**
(DSS-induced)
SASP group (300 mg/kg)
10/10
2.27 ± 0.43##
3.24 ± 0.77##
Compound 7 in HD
10/10
1.33 ± 0.31##
2.05 ± 0.28##
group (500 mg/kg)
Compound 7 in MD
10/10
2.01 ± 0.27##
3.30 ± 0.66##
group (250 mg/kg)
Compound 7 in LD
10/10
3.01 ± 0.38
4.93 ± 0.61
group (125 mg/kg)
5. In vivo Test Results of Compound 1
{circle around (1)} Compound 1 can effectively reduce the weight loss in C57/blc mice with DSS-induced UC in a good dose-dependent manner (see Table 4).
From Table 4, it is shown that compound 1 can reduce the weight loss in C57/blc mice with DSS-induced UC. In Table 4, **p<0.01 when compared with the normal control group; #p<0.05, ##p<0.01 when compared with the model group. It is not very obvious for compound 1 in HD group to inhibit the weight loss of experimental animal which is probably related with the inhibition of compound 1 to the animal appetite (data not shown). Yet, with the dosage of compound 1 gradually decreased (on the case of 75 mg/kg of dose) the experimental animals gain in body weight, even more prominent than the positive drug SASP.
TABLE 4
The therapeutic effect of compound 1 on C57/blc mice with
DSS-induced acute UC in vivo
Body weight
Change
n (start/
(g) x ± SD
of body
Groups
end)
start
end
weight (%)
Normal control
10/10
20.75 ± 1.1
22.25 ± 0.9
↑ 7.22
group
Model group
10/10
21.15 ± 1.2
19.80 ± 1.1
↓ 6.38**
(DSS-induced)
SASP group
10/10
20.85 ± 1.4
21.15 ± 0.6
↑ 1.44##
(300 mg/kg)
Compound 1 HD
10/10
20.07 ± 1.1
19.87 ± 1.0
↓ 1.00##
group (500 mg/kg)
Compound 1 MD
10/10
20.30 ± 1.1
19.95 ± 1.6
↓ 1.72#
group (250 mg/kg)
Compound 1 LD
10/10
20.65 ± 1.3
21.15 ± 1.1
↑ 2.42##
group (75 mg/kg)
Effect of compound 1 on DAI and macroscopic score of colon tissue in C57/blc mice with DSS-induced UC (see Table 5).
DAI is evaluated by weight loss, shape of stool, hematochezia, and other indicators; macroscopic score of colon tissue is calculated by intestinal mucosal hyperemia, edema of intestinal wall, ulcer size, and other indicators. The lower the DAI and macroscopic score is, the more close to the physiological state of the normal animal. In Table 5: **p<0.01 when compared with the normal control group; #p<0.05, ##p<0.01, when compared with the model group.
TABLE 5
Effect of compound 1 on DAI and macroscopic score of colon
tissue in C57/blc mice with DSS-induced UC
macroscopic
score of
Groups
n (start/end)
DAI
colon tissue
Normal control group
10/10
0.00 ± 0.00
0.15 ± 0.01
Model group
10/10
3.39 ± 0.64**
5.69 ± 1.12**
(DSS-induced)
SASP group (300 mg/kg)
10/10
2.54 ± 0.23##
2.95 ± 0.52##
Compound 1 HD group
10/10
2.33 ± 0.11##
2.66 ± 0.46##
(300 mg/kg)
Compound 1 MD group
10/10
1.81 ± 0.27##
2.01 ± 0.16##
(150 mg/kg)
Compound 1 LD group
10/10
2.99 ± 0.14#
4.93 ± 0.61
(75 mg/kg)
6. In vivo Test Results of Compound 2.
{circle around (1)} Compound 2 can effectively reduce the weight loss in C57/blc mice with DSS-induced UC in a good dose-dependent manner (see Table 6).
As shown in table 6, it is indicated that compound 2 can effectively reduce the weight loss in C57/blc mice with DSS-induced UC at a dose of 300 mg/kg. In Table 6, **p<0.01 when compared with normal control group; ##p<0.01 when compared with the model group.
TABLE 6
The therapeutic effect of compound 2 on C57/blc mice with
DSS-induced acute UC in vivo
Body weight
Change
n (start/
(g) x ± SD
of body
Groups
end)
start
end
weight (%)
Normal control
10/10
27.22 ± 2.2
29.43 ± 1.6
↑ 8.12
group
Model group
10/10
28.60 ± 1.5
22.25 ± 1.8
↓ 22.22**
(DSS-induced)
SASP group
10/10
27.89 ± 2.5
25.09 ± 0.9
↓ 12.09##
(300 mg/kg)
Compound 2
10/10
28.56 ± 1.2
26.17 ± 1.5
↓ 8.37##
group (300 mg/kg)
Effect of compound 2 on DAI and macroscopic score of colon tissue in C57/blc mice with DSS-induced UC (see Table 7).
DAI is evaluated by weight loss, shape of stool, hematochezia, and other indicators; macroscopic score of colon tissue is evaluated by intestinal mucosal hyperemia, edema of intestinal wall, ulcer size, and other indicators. The lower the DAI and macroscopic score is, the more close to the physiological state of the normal animal. DAI: Disease activity index; in Table 7: **p<0.01 when compared with the normal control group; ##p<0.01 when compared with the model group. Compound 2 can effectively alleviate the loose stools, hematochezia, and other symptoms of subjects at the dosage of 300 mg/kg, and shows more prominent efficacy than the positive drug SASP.
TABLE 7
Effect of compound 2 on DAI and macroscopic score of
colon tissue in C57/blc mice with DSS-induced UC
macroscopic
score of
Groups
n (start/end)
DAI
colon tissue
Normal control group
10/10
0.00 ± 0.00
0.10 ± 0.01
Model group
10/10
3.85 ± 0.34**
5.59 ± 1.01**
(DSS-induced)
SASP group (300 mg/kg)
10/10
2.27 ± 0.43##
3.24 ± 0.77##
Compound 2 group
10/10
1.05 ± 0.26##
2.94 ± 0.21##
(300 mg/kg)
|
Disclosed are derivatives of protoberberine biological alkaloids or physiologically acceptable salts thereof produced by means of a derivative reaction of a source material of biological alkaline quaternary ammonium salts of protoberberine alkaloids, a preparation method for same and pharmaceutical uses thereof. The derivatives of protoberberine biological alkaloids or the physiologically acceptable salts thereof show activity inhibiting ulcerative colitis and can be used in the preparation of drugs for same.
| 2
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BACKGROUND OF THE INVENTION
The present invention relates generally to a torsion bar-type automotive vehicle suspension. More specifically, the invention relates to a torsion bar suspension which is compact enough to provide adequate road clearance for the vehicle.
In conventional torsion bar-type suspension, a lower suspension arm supporting a vehicle wheel via a knuckle is pivotably suspended by means of a torsion bar. The torsion bar is fixed to the vehicle body at one end by means of a bracket with a bushing assembly. In this case, the bracket must be large enough to accommodate the bushing assembly and allow the torsion bar to pass through the axial opening of the bushing assembly. Such brackets may provide only marginally sufficient road clearance for the vehicle. In other words, the bracket may be so big as to strike the road surface while the vehicle is travelling over rough roads.
In addition, since the bifurcated inner ends of the lower arm are connected to the torsion bar in axial alignment with respect to the latter, when forces are applied to the knuckle along the longitudinal axis of the torsion bar, such as during acceleration, deceleration and so forth, relatively large lateral forces are applied at the junction between the rear leg of the bifurcated lower arm and the torsion bar. Due to these lateral forces, the the bushing in the bushing assembly deforms laterally, resulting in compliance steering by which the toe angle of the wheel will change in the toe-out direction. As will be appreciated, due to this toe-out change, the cornering force will be reduced, thereby degrading driving stability.
SUMMARY OF THE INVENTION
Therefore, it is an object of the present invention to provide a torsion bar-type vehicle suspension which has a suspension arm connected to the vehicle body by means of a bracket of reduced size.
Another and more specific object of the present invention is to provide a torsion bar suspension which has a suspension arm with front and rear legs extending therefrom, which legs are connected to the vehicle body at a position offset laterally from the vehicle longitudinal axis.
According to the present invention, a torsion bar suspension is provided with a torsion bar connected to a lower suspension arm and independent of the connection between the lower suspension arm and the vehicle body. The torsion arm is connected to the lower arm at a position remote from the position in which the lower arm is connected to the vehicle body. The torsion bar suspension also incorporates a compression rod for connecting the lower suspension arm to the vehicle body, which compression rod is located outboard of the torsion bar and connected to the vehicle body at a point rearward of its connection to the lower arm. A bushing assembly is provided between the vehicle body and the lower arm, allowing lateral and vertical movement of the lower arm relative to the vehicle body.
In a preferred structure, the pivotal axis of the lower arm is inclined forward, i.e., its forward end is lower than the rearward end and the torsion bar extends parallel to this pivotal axis.
A torsion bar suspension for an automotive vehicle, according to one aspect of the present invention, comprises a suspension arm rotatably supporting a vehicle wheel at the outer end thereof and having first front leg portion and second rear leg portion, first bracket secured to the vehicle body and pivotably securing the first leg of the suspension arm onto the vehicle body, a torsion bar connected to the first leg of the suspension arm and extending essentially along the longitudinal vehicle axis at one end thereof, the other end thereof being secured to the vehicle body, second bracket secured to the vehicle body and pivotably connecting the rear leg of the suspension arm onto the vehicle body, the second bracket being located outer-side of the torsion bar, and a compression rod interpositioned between the second leg of the suspension arm and the second bracket so that is may be connected to the second bracket at rear side of the rear end of the second leg.
According to another aspect, a torsion bar suspension for an automotive vehicle comprises an upper suspension arm, a lower suspension arm having an outer end cooperative with the outer end of the upper suspension arm for rotatably suspensing a vehicle wheel and having first and second inner ends connected to a vehicle body, a first pivot means for connecting the first inner end of the lower arm so that the lower arm is pivotable above a pivot axis extending essentially along the vehicle longitudinal axis, a torsion bar connected to the first inner end of the lower arm at a portion remote from the first pivot means, the torsion bar extending to align the axis thereof with the pivot axis of the first pivot means, a rod member connecting the second inner end of the lower arm to the vehicle body, the rod member having an axis extending across the axis of the torsion bar, the rod member connected to the vehicle body at a position laterally offset from the torsion bar and at rearward of the rear end of the second inner end of the lower arm.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be understood more fully from the detailed description given herebelow and from the accompanying drawings of the preferred embodiment of the present invention, which, however, should not be taken to limit the invention but are for explanation and understanding only:
In the drawings:
FIG. 1 is a plan view of the preferred embodiment of a torsion bar suspension according to the present invention;
FIG. 2 is a side elevation of part of the torsion bar suspension of FIG. 1;
FIG. 3 is an enlarged view in partial section of the area labelled A in FIG. 1;
FIG. 4 is an enlarged view in partial section of the area labelled B in FIG. 1;
FIG. 5 is an enlarged view in partial section of the area labelled C encircled in FIG. 1; and
FIG. 6 is an explanatory diagram of the forces applied to parts of the torsion bar suspension of FIG. 1 during acceleration of the vehicle.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, particularly to FIGS. 1 and 2, a torsion bar-type vehicle suspension generally comprises upper and lower arms 10 and 12 respectively extending essentially perpendicularly to the longitudinal axis of the vehicle. The outer ends of the upper and lower arms 10 and 12 support a vehicle wheel via a knuckle (not shown). The inner ends of the upper and lower arms 10 and 12 are both pivotably connected to the vehicle body. The lower arm 12 is associated with a torsion bar 18 which provides a resilient damping force for absorbing relative displacements between the vehicle body and the vehicle wheel.
Upper and lower ball joints 20 and 22 are rigidly secured to the outer ends of the upper and lower arms 10 and 12 by mean of fastener bolts 24. The upper and lower ball joints 20 and 22 serve to pivotably support the knuckle 14 which has a spindle (not shown) for rotatably supporting the wheel hub, and/or a brake assembly in per se known manner.
The upper arm 10 has a generally U-shaped configuration defined by bifurcated legs 28 and 30 respectively extending inwardly. Each of the legs 28 and 30 has an inner end 32, each of which is rotatably engaged to one end 34 of a connecting rod 36 via bushing assemblies 38, which connecting rod is rigidly secured to the vehicle body.
As shown in FIG. 3, the bushing assembly 38 comprises an outer collar 40, an elastic bushing 42 which is made of rubber, for example, and an inner collar 44. The outer collar 40 has a radially extending flange 46 at one end and is adapted to be rigidly secured within an opening 48 in the inner end 32 of leg 28 or 30. The inner collar 44 has radial flanges 50 and 52 at both ends. The flanges 50 and 52 serve to retain the elastic bushing 42 over the inner collar. The hollow tubular inner collar 44 accommodates the end of the connecting rod 36. The connecting rod 36 has smaller diameter sections 34 at both ends to which the inner ends 32 of the legs 28 and 30 of the upper arm 10 are connected. The smaller diameter sections 34 are threaded to engage fastener nuts 56 so as to fix the inner ends 32 to the connecting rod 36.
With this construction, the upper arm 10 is pivotable about the axis P 1 of the connecting rod 36.
As shown in FIGS. 1 and 2, the lower arm 12 has a body 58 and front and rear extensions 60 and 62. The rear extension 62 is connected to a compression rod 64 which is, in turn, connected to a connecting bracket 66 of the vehicle body. On the other hand, the front extension 60 has bifurcated end sections 68 and 70 with through openings 72. A connecting rod 74 extends through the opening 72 of the bifurcated end sections 68 and 70 is fixed thereto by means of a fastener nut 76 engaging a threaded portion 78 of the connecting rod 74. The portion of the connecting rod 74 between the end sections 68 and 70 passes through a bushing assembly 80 rigidly fixed to the vehicle body.
As apparent from FIG. 2, a longitudinal axis P 2 of the connecting rod 74 is inclined forward at an angle θ 1 with respect to the vehicle horizontal plane. This tilt angle θ 1 is intended to suppress pitching movement of the vehicle body, and especially to suppress diving of the vehicle body during deceleration and so forth. Hereafter, the foregoing angle θ 1 of the connecting rod 74 will be referred to as the "anti-dive angle".
As shown in FIG. 4, the bushing assembly 80 comprises an outer collar 82 which is rigidly secured to the vehicle body, although it is not shown in the drawings by what means it is fixed to the vehicle body, an elastic bushing such as a rubber bushing 84 and an inner collar 86. As apparent from FIG. 4, the inner collar 86 extends beyond the ends of the elastic bushing 84 to cover almost the entire length of the connecting rod 74 and has a flange 88 at one end thereof, which flange 88 contacts the end section 68.
The front end of the torsion bar 18 is attached to the inner end section 70 of the extension 60 by means of a fixing bracket 90 secured to the front end of the torsion bar 18 and rigidly fixed to the end section 70 by means of fastener bolts 92 and nuts 94. A dust cover 96 fits over the junction of the torsion bar 18 and the end section 70. The longitudinal axis P 3 of the torsion bar 18 is approximately aligned with the axis P 2 of the connecting rod 74 and so matches the anti-dive angle. It should be appreciated that the rear end of the torsion bar 18 is fixed to the vehicle body in a per se well-known manner, although it is not shown in the drawings.
As shown in FIG. 5, the front end of the compression rod 64 is connected to the rear extension of the lower arm 12 by means of a fastener bolt 98. The rear end of the compression rod 64 is equipped with a bushing assembly 100 by which the compression rod is connected to the vehicle body bracket 66. The bushing assembly 100 has an inner collar 102 extending coaxially with the compression rod, and a pair of elastic bushings 104 and 106 located on opposite sides of the bracket 66. The bushing assembly 100 is secured to the compression rod 64 by means of a fastener nut 108 engaging a threaded portion 110 of the compression rod.
In the foregoing structure, the lower arm 12 can be displaced about the compression rod 64 while deforming the bushings 102 and 104. On the other hand, the lower arm 12 is rotatable about an imaginary pivot axis which lies in approximate alignment with the axis P 2 of the connecting rod 74.
Additionally, the shown torsion bar vehicle suspension is provided with a shock absorber 112 responsive to vertical forces to allow relative vertical displacement between the vehicle body and the vehicle wheel while producing a damping force thereagainst. Also, a stabilizer 114 is provided to increase the reaction force to lateral forces in order to increase cornering force and so forth for the sake of driving stability.
From the geometrical point of view of the preferred structure of the torsion bar suspension as illustrated, the axis P 4 of the compression rod 64 is inclined forward at a given angle θ 2 with respect to the the axis P 3 of the torsion bar 18 on the plane extending through the pivot axis of the lower arm 12. That is, the above plane is inclined relative to vehicle horizontal plane at the angle approximately corresponding to the tilt angle θ 1 of the connecting rod 74. The torsion bar 18 is closer to the longitudinal axis of the vehicle than the junction between the compression rod 64 and the vehicle body bracket 66, i.e., it lies inward of the latter. In addition, as apparent from FIG. 2, the junction between the compression rod 64 and the vehicle body bracket lies at approximately the same elevation as the corresponding portion of the torsion bar 18. In other words, the junction, the axis P 4 of the compression rod 64 and the torsion bar 18 all lie in the same plane inclined at the angle θ 1 relative to the vehicle horizontal plane.
From the structural view point, the torsion bar 18 is connected to the end section 70 of the front extension 60 of the lower arm and is separated from the junction between the lower arm and the vehicle body and so is indirectly connected to the vehicle body. Furthermore, the rear extension of the lower arm 12 is connected to the vehicle body via the compression rod 64, the junction of which with the vehicle body is separated from the torsion bar 18 laterally. This structure effectively prevents impact of the mentioned junctions on the road surface during compliance steering or while travelling on rough roads.
While the vehicle is running, road shock and other vibrations are applied to the vehicle wheel. Due to the vibrations applied through the wheel, the upper and lower arms 10 and 12 pivot about their respective pivot axes P 1 and P 2 . Due to this pivotal movement of the lower arm 12, the fixing bracket 90 secured thereto thus rotates about the pivot axis P 2 , thus twisting the torsion bar 18. The torsion bar 18 produces a counteracting torsional force against the rotational force applied to the lower arm 12. This torsional force created by the torsion bar 18 serves as a damping force against vehicle wheel vibrations so as to stabilize the wheel. Furthermore, due to the torsional force of the torsion bar 18, the vehicle wheel is constantly biased towards the road surface so that roadand-tire traction remains approximately constant.
On the other hand, when a torque is applied to the wheel axle during acceleration, deceleration and so forth, a backward force Fo is applied to the knuckle at the point A. Due to this backward force Fo, compliance steering occurs, deforming the various bushings. Due to the backward force Fo, a force represented by the arrow f in FIG. 6 is applied to a point Co defined by the intersection of a line defined by the point A of the knuckle and a point C on the vehicle body bracket 66 and the axis P 4 of the torsion bar 18.
The force f at the point Co has an axial component f s of the force directed axially along the torsion bar 18, and a lateral component f h of the force directed perpendicular to the axis of the torsion bar 18. At the same time, a force F is applied to the point C on the vehicle body bracket 66 parallel to the line including the points A and Co. The force F has an axial component F S parallel to the axis P 4 of the compression rod 64 and a lateral component force F H perpendicular to the axis P 4 .
Due to the lateral component f h of the force f and the lateral component F H of the force F, the bushings 84 of the bushing assembly 80 and the bushings 104 and 106 of the bushing assembly 100 are deformed to allow horizontal pivotal displacement of the lower arm 12. This horizontal pivotal displacement of the lower arm 12 causes displacement of the wheel axis resulting in a change in toeing angle. According to the shown embodiment, the lateral component F H , which causes deformation of the bushings 104 and 106, is quite limitted so that pivotal movement of the lower arm 12 is minimized in order to reduce the magnitude of toe-angle change in the toe-out direction during compliance steering.
As a result, the suspension of the shown embodiment provides improved driving stability for the vehicle.
In addition, as set forth above, the connection of the lower arm of the suspension according to the present invention provides adequate road clearance for the vehicle so that impact between the suspension and the road surface is satisfactorily and successfully prevented. Furthermore, because the various connection between the vehicle body and the lower arm are remote from one another, the connections do not interfere with one another.
|
A torsion bar suspension is provided with a torsion bar connected to a lower suspension arm and independent of the connection between the lower suspension arm and a vehicle body. The torsion arm is connected to the lower arm at a position remote from the position in which the lower arm is connected to the vehicle body. The torsion bar suspension also includes a compression rod connecting the lower suspension arm to the vehicle body, which compression arm is located outward of the torsion bar and is connected to the vehicle body at a point rearward of its connection to the lower arm. A bushing assembly is provided between the vehicle body and the lower arm allowing lateral and vertical movement of the lower arm relative to the vehicle body.
| 1
|
FIELD OF THE INVENTION
The present invention relates to static progressive splinting. More particularly, the present invention relates to a monofilament slide lock that is used in connection with a splinting apparatus to allow for the adjustment of inelastic traction.
BACKGROUND OF THE INVENTION
The use of splints in the treatment of certain injuries to joints and soft tissue is often an integral part of rehabilitation. Initially, following surgery or an injury, splinting can be used to immobilize and protect the injured area to allow healing. Unlike a cast, however, a splint can be removed for basic hygiene or wound care or to allow a patient to perform therapeutic exercises. Furthermore, depending on the injury and required treatment, a splint can be used to allow a range of motion to an injured joint.
Static progressive splinting, a technique using mobilization splinting with inelastic traction, is one of the most efficient methods for lengthening soft tissue with limited pliability and for increasing the progressive range of motion (PROM) of contracted joints. By splinting and maintaining tissue at the available end-range under low-load stress, the structures have time to grow new cells, and a new end-range is established. After the tissues lengthen, the inelastic mobilization component can be adjusted in small increments to maintain low-load prolonged stress at the newly established end-range.
Over the past twenty years, therapists have adjusted static progressive splints to produce low loads over a prolonged time. While rubber band traction was commonly used in the prior art, modern day static progressive splinting requires the use of devices that can be easily adjusted by the patient as muscles relax in the splint. Accordingly, therapists today typically construct static progressive splints by attaching turnbuckles or similar locking mechanisms to a thermoplastic brace and connect straps, strings, monofilaments, or click strips to the locking mechanism in order to position the splinted joint near the end range of motion.
While these modern day static progressive splinting techniques are effective for soft tissue rehabilitation, they are often heavy, bulky, or cumbersome. As a result, the devices can cause patient fatigue and catch on a patient's clothing. In addition, the large size and complexity of the devices precludes a therapist from using multiple units with a single splint and prevents a patient from easily adjusting the position of the splint. Accordingly, there is a demand for an improved mobilization device for use in static progressive splinting.
SUMMARY OF THE INVENTION
The present invention overcomes the deficiencies of the prior art by providing an improved immobilization device for static progressive splinting. In accordance with the present invention, the improved monofilament slide lock comprises a housing, a glide member, and a locking wheel.
One embodiment of the present invention provides for a housing having a low profile, streamlined design in order to prevent the device from snagging on a patient's clothes. It is another feature of the invention for the housing to accommodate and secure more than one monofilament, further reducing the overall size of the splint for a patient.
Yet another feature of the invention is to provide a glide member with a simple push button device for adjusting the tension of the splint along an unlimited range of motion. In addition, the overall size and weight of the slide lock is reduced to eliminate patient fatigue and compliance.
These and other features and advantages of the present invention will be apparent to those skilled in the art upon review of the following detailed description of the drawings and preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a static progressive splinting system utilizing the present invention.
FIG. 2 is a perspective view of the present invention.
FIG. 3 is a perspective view of the housing of present invention.
FIG. 4 is a perspective view of the glide member of the present invention.
FIG. 5 is a perspective view of an alternate embodiment of the wheel of the present invention.
FIG. 6 is a perspective view of an assembly of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
A monofilament slide lock made in accordance with the principles of the present invention is depicted in FIGS. 2-6 . The present invention is to be used in a static progressive splinting system such as the one shown in FIG. 1 . The system 1 includes a sling 2 , a plurality of monofilaments 4 , a splint 5 , and a monofilament slide lock 8 for securing the tension of the monofilaments 4 . The slide lock 8 of the present invention generally comprises a housing 10 , a glide member 70 , and a locking wheel 100 .
As shown in FIG. 3 , the housing 10 has an upper ridge 20 and a lower ridge 30 positioned on a first sidewall 59 . The upper ridge 20 extends from the rear surface 50 of the first sidewall 59 to the front surface 40 and terminates at each end at a column 22 , 24 . A second sidewall 60 has an upper ridge 66 and two posts 62 , 64 . Both upper ridges 20 , 66 are preferably equipped with a textured outer surface 200 , 660 , and the second sidewall 60 is preferably linked to the lower ridge 30 on the first sidewall 59 with a connection strip 25 . While many methods of connecting the sidewalls 59 , 60 are well known in the art, the connection strip 25 is preferred because it maintains the alignment of the first sidewall 59 and second sidewall 60 when the housing 10 is assembled. Assembly of the housing 10 is then preferably completed by inserting the posts 62 , 64 into the holes 26 , 28 in each respective column 22 , 24 .
When the sidewalls 59 , 60 are assembled as shown in FIG. 2 , they define a slot 68 and a cavity (not shown) for the glide member 70 . The glide member 70 , shown in FIG. 4 , has a button 80 and a base portion 90 . In a completely assembled slide lock 8 shown in FIG. 2 , the button 80 preferably resides on the outside of the housing 10 and has a curved and textured top surface 82 to allow a patient to easily grip and move the device. The button 80 may also be equipped with a lip 81 that engages with the textured outer surfaces 200 , 660 of the upper ridges 20 , 66 .
The base portion 90 of the glide member 70 resides in the cavity of the housing 10 . In the preferred embodiment of the glide member 70 shown in FIG. 4 , the base 90 has two legs 92 , 95 that define a channel 99 and an arced open casing 97 . The channel 99 is preferably sized to receive the upper ridges 20 , 66 of the housing 10 while the arced open casing 97 is preferably sized to receive a locking wheel 100 such as is shown in FIG. 5 .
In FIG. 6 , the assembly of the slide lock 8 is shown. The upper ridge 20 of the first sidewall 59 of the housing 10 fits loosely within the channel 99 of the glide member 70 , allowing the glide member 70 to slide on the upper ridge 20 between the two columns 22 , 24 . The locking wheel 100 similarly fits loosely within the arced open casing 97 of the glide 70 , allowing the locking wheel 100 to rotate as the glide 70 slides between the two columns 22 , 24 .
In the preferred embodiment of a fully assembled slide lock 8 , the wall of the lower ridge 30 defines the floor 36 of the housing cavity and the upper ridges 20 , 66 slope downward from the rear surface 50 to the front surface 40 . In order to accommodate for the sloped upper ridges 20 , 66 , the front leg 92 of the glide 70 is preferable shorter than the rear leg 95 . With this configuration, when the glide 70 abuts the rear column 24 , the locking wheel 100 is held above the floor 36 , and when the glide 70 abuts the front column 22 , the locking wheel engages the floor 36 .
In order to use the completely assembled slide lock 8 shown in FIG. 2 as part of a static progressive splinting system 1 like that shown in FIG. 1 , the slide lock 8 is simply attached to a thermoplastic splint 5 and the monofilaments 4 from the sling 2 are passed through a front opening 42 , under the locking wheel 100 in the cavity, and out a rear opening 52 . In order to control the tension in the monofilaments 4 , the button 80 can then slide into place against the front column 22 , forcing the locking wheel 100 against the monofilaments 4 and the floor 36 . In this way, the slide lock 8 allows patients to adjust the tension of the monofilaments 4 to an infinite number of positions and thereby precisely control adjustments and document progress in the range of motion of an injured limb.
One skilled in the art of splinting should recognize that the monofilaments can be locked in place more effectively by adding textured surfaces to the slide lock of the present invention. For example, while a flat floor 36 will provide an adequate surface to secure the tension of the monofilaments 4 , the floor 36 could also be equipped with a bump 34 to enhance the strength of the bond between the locking wheel 100 and the floor 36 . Similarly, while a smooth outer surface on the locking wheel 100 will provide adequate tension, a knurled or textured outer surface 102 provides enhanced tension and is preferred. Finally, while smooth upper ridges 20 , 66 and a smooth button 80 are adequate, the interaction of a lip 81 on the button 80 with the textured outer surfaces 200 , 660 of the upper ridges 20 , 66 provide a more secure lock.
One skilled in the art of splinting should also recognize that the slide lock 8 of the present invention could be made of many different materials and in many different sizes. In the preferred design, however, the housing 10 and glide 70 are constructed from plastic while the locking wheel is made of metal since these materials are exceptionally economical and lightweight. Furthermore, a low-profile, streamlined design measuring 1 cm wide by 2.5 cm long and only 1.2 cm high has proven to be the most effective size for eliminating snagged clothing, minimizing bulk, and allowing multiple slide locks to be used on a single splint.
It should be understood that the illustrated embodiments are exemplary only and should not be taken as limiting the scope of the present invention. The claims should not be read as limited to the order or elements unless stated to that effect. Therefore, all embodiments that come within the scope and spirit of the following claims and equivalents thereto are claimed as the invention.
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The invention is a slide lock for adjusting static progressive splints having a housing, a glide member, and a wheel whereby a monofilament can pass through the housing and be securely held in place by using the glide to force the wheel toward the floor of the housing.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This Application relates to and claims priority from commonly owned U.S. Provisional Patent Application Ser. No. 60/776522, filed on Feb. 24, 2006 and U.S. patent application Ser. No. 11/431,366, filed on May 9, 2006.
FEDERALLY SPONSORED RESEARCH
[0002] Not Applicable
SEQUENCE LISTING OR PROGRAM
[0003] Not Applicable
TECHNICAL FIELD
[0004] This invention relates to a holding device and a method of coating hollow cylindrical objects using the device. More specifically, the present invention provides a holding device and a method of reproducibly and securely supporting and rotating one or more hollow cylindrical objects, such as stents, during a coating process while minimizing runout of the hollow cylindrical object during rotation, and surface contact between the hollow cylindrical object and the holding device.
BACKGROUND
[0005] Coatings are often applied to medical appliances, such as pacemakers, vascular grafts, stents, and heart valves, to have desired effects and increase their effectiveness. These coatings may deliver a therapeutic agent or drug to the lumen that reduces smooth muscle tissue proliferation or restenosis. Furthermore, medical devices may be coated to provide beneficial surface properties, achieving enhanced biocompatibility and to improve surface properties such as lubriciousness. Balloon delivery systems, stent grafts and expandable stents are specific examples of medical appliances or implants that may be coated and inserted within the body. Stents such as described in U.S. Pat. No. 4,733,665, are tiny, expandable mesh tubes supporting the inner walls of a lumen used to restore adequate blood flow to the heart and other organs.
[0006] Conventionally, coatings are applied to the stent in a number of ways including, though not limited to, dip coating, spin coating or spray coating. Spray coating processes generally require an apparatus to securely hold and rotate the flexible, tiny stent structure during the coating operation to allow a reproducible and homogeneous coating application on the whole surface.
[0007] However, holding devices known from the prior art have several drawbacks which may result in low volume production of medical devices, damage to the fragile stent structure, inhomogeneous coatings, uncoated areas, coating accumulations, and the like. Coating accumulations, such as shown in FIG. 13 , can lead to severe damages of the coating due to a possible loss of the coating during loading, transportation, and/or deployment of the stent. Coating defects, such as uncoated areas and coating thickness variations on the stent surface may compromise the implant's effectiveness due to potential complications arising from an inhomogeneous distribution of the therapeutic agent at the target site.
[0008] Stent holding devices, as described in U.S. Pat. No. 6,605,154, comprising a mandrel passing all the way through the inner hollow body of the stent to support the stent via support members, which partially penetrate into the opposing sides of the hollow body of the stent by incrementally moving at least one support member closer to the other, can have several disadvantages.
[0009] When using such stent holding devices there may be a risk of coating defects at the ends of the stent due to the design of the support elements. The clamping force can vary from stent to stent, which may lead to sagging or buckling of the stent. Mandrels having a small diameter and a comparatively long length of approximately 40-80 mm may easily bend resulting in a runout of the stent. In most cases the run out of the mandrel is several mm which may effect the coating weight consistency. Moreover stent holding devices, as described in U.S. Pat. No. 6,572,644, comprising members projecting out of a body to contact the stent may not center and secure the stent sufficiently.
[0010] Runout, sagging and buckling of the stent may cause an inhomogeneous coating thickness, coating defects on the stent surface and coating weight deviations. Coating consistency may vary from stent to stent depending on runout and positioning accuracy of the support members.
[0011] In addition, coating defects including uncoated areas may arise when stent holding devices are used having a structure which interferes with the spray plume as described in WO Pat. No. 2004/008995.
[0012] Damage of the coating may also occur after completion of the coating process during handling and inspection. Inspection of medical devices generally requires dismounting the stent from the holding device being used during the coating process in order to mount the stent to an inspection fixture that typically contacts the outer surface of the stent.
[0013] Finally, stent holding devices known by the prior art are not designed to support and/or coat multiple stents simultaneously or to be used for subsequent inspection of the coated stents.
SUMMARY
[0014] There is therefore a need for a device and a coating method which will improve the efficiency, stability and reproducibility of the stent coating process by securing the stent during the coating operation without disturbing the coating process, damaging the medical device and/or coating and by permitting higher volume, low cost production of high quality coated medical devices.
[0015] Accordingly, a multi-purpose holding device for handling, securing and rotating one or more medical devices and a method for coating one or more medical devices, such as stents, is provided. The holding device includes a rigid frame structure and interchangeable support members to allow precise alignment of the medical device within the frame structure and minimized runout. To avoid coating defects, the support member do not extend completely through the medical device, provide minimized surface contact with respect to the medical device and do not block the spray plume from uniformly coating the entire stent.
[0016] In one embodiment of the present invention, a holding device for handling, securing and rotating at least one stent is provided. The holding device comprises a frame and at least two support members being coupled to the frame and in contact with at least a portion of the stent. The support members have a first position of being engaged with the stent at two opposing sides to securely hold the stent and the support members can be rotated in relation to the frame to rotate the stent. At least one support member has a second position of being disengaged from the stent to unload the stent. In one or more embodiments, the holding device further comprises at least one shaft, which can be rotated in relation to the frame in order to transmit rotary motion to the support members. It may also comprise members to transmit rotary motion between the shaft and the support members. In addition, sleeves may be rotably mounted to the frame so that in the first position the support member is coupled to the sleeve to transmit rotary motion, and in the second position the support member is uncoupled from the sleeve. Each support member may comprises a structure at least partially surrounding the end of the stent and a member, such as a thread or a rod, connecting the surrounding portion of the structure in order to contact the stent. The member may be part of the structure or may be exchangeable, and may include at least one portion with a larger cross-section having a spherical or a cylindrical shape to center the stent. The support member may contact at least partially the inner surface of the stent and the portion of the support member contacting the inner surface of the stent may comprise at least two sides being parallel to the longitudinal axis of the stent. Alternatively, the support member may contact at least partially the inner surface of the stent and the portion of the support member contacting the inner surface of the stent may comprise at least two edges being parallel to the longitudinal axis of the stent.
[0017] In a next embodiment, a method is provided for securing and rotating at least one stent using a holding device having a frame and at least two opposing support members being coupled to the frame, which are coaxially arranged and can be rotated in relation to the frame. In a first step, at least one support member is located at a first position in which the distance between the support members is larger than the stent length. In a next step, a stent is positioned between the support members. Then, at least one support member is located at a second predetermined position in which the distance between the support members is smaller than the stent length to reproducibly secure the stent. In another step, rotary motion is transmitted to the support member to rotate the stent in relation to the frame. In one or more embodiments, a shaft being rotably mounted to the frame is additionally provided and rotary motion is induced in the shaft and transmitted to the support members to rotate the stent in relation to the frame. In a further step, the holding device may be positioned so that the holding device is at least partially in contact with one or more guide members and the holding device may be translated along the guide member. In another step, a coating may be applied to the stent.
[0018] In still another embodiment, an apparatus for translating and rotating one or more stents comprises at least one guide member and a detachable holding device having a frame, at least one shaft being rotable in relation to the frame, and at least two support members being rotable in relation to the frame and securing a stent at two opposing ends. The holding device is in contact with at least a portion of the guide member to secure its angular position and can be moved along the guide member to translate the stent, and the stent can be rotated in relation to the holding device by applying rotary motion to at least one of the rotable members being coupled to the frame.
[0000] In one or more embodiments, the apparatus may further comprise a spray source to apply a coating to the stent. The apparatus may additionally include at least one motion unit to transmit rotary and linear motion to the holding device in order to rotate and translate the stent. Furthermore, at least one inspection device may also be provided and the holding device can be moved along one or more guide members to position the stent in relation to the inspection device.
[0019] In yet another embodiment, a holding device for handling, securing and rotating at least one medical device is provided. The holding device includes a frame and at least one support member contacting at least a portion of the medical device, wherein the support member is coupled to the frame and can be rotated in relation to the frame to rotate the medical device.
[0000] In one or more embodiments, the holding device may further comprise a shaft being mounted to the frame, which can be rotated in relation to the frame to transmit rotary motion to at least one support member.
DRAWINGS
[0020] The accompanying drawings, which are incorporated in and constitute a part of this specification, serve to explain the principles of the invention. The drawings are in simplified form and not to precise scale.
[0021] FIG. 1A is a front view showing a holding device to support and to rotate one or more stents;
[0022] FIG. 1B is a front view showing the holding device with mounted stent;
[0023] FIG. 2 is a front view showing a holding device to support and to rotate one or more stents including a shaft and a guide section;
[0024] FIG. 3 is a top view showing a holding device to support and to rotate six stents;
[0025] FIG. 4A is a top view of a holding device to support and rotate two stents;
[0026] FIG. 4B is a cross-section view of the holding device of FIG. 4A ;
[0027] FIG. 5A is a top view of a holding device to support and rotate two stents during unloading;
[0028] FIG. 5B is an cross-section view of the holding device of FIG. 5A ;
[0029] FIG. 6A is an isometric view showing a support member to contact a stent;
[0030] FIG. 6B is an isometric detail view of FIG. 6A ;
[0031] FIG. 7 is an isometric view showing an alternative support member to contact a stent;
[0032] FIG. 8 is an isometric view showing an alternative support member to contact a stent;
[0033] FIG. 9A is an isometric view showing an alternative support member to contact a stent;
[0034] FIG. 9B is an isometric view showing an alternative support member to contact a stent having two centering elements;
[0035] FIG. 9C is an isometric view showing an alternative support member to contact a stent having one centering element;
[0036] FIG. 10 is an isometric view showing an apparatus comprising a holding device to support and to rotate two stents during a spray coating process;
[0037] FIG. 11 is an isometric view showing a holding device to support and to rotate two stents during the step of optical inspection;
[0038] FIG. 12 is an image of a portion of a coated stent; and
[0039] FIG. 13 is an image of a portion of a coated stent comprising a coating defect.
DETAILED DESCRIPTION
[0040] The following figures illustrate embodiments of a holding device and a method to secure and/or rotate one or more medical devices during various process steps, such as handling and the application and/or inspection of a coating. FIG. 1A and FIG. 1B depict a schematic of an exemplary holding device including a frame 17 and one set of support members 6 being bearing mounted to the frame to securely hold a stent. Referring now to FIG. 1A , stent 1 is positioned between the support members 6 , which are engaged with the stent at two opposing sides so that the stent is securely held and can be rotated in relation to the frame (first position). In FIG. 1B the support members are disengaged from the stent to unload the stent by moving at least one support member in axial direction away from the stent (second position). Both support members remain coupled to the frame.
[0041] The rigid frame structure of the holding device not only ensures secure handling of the stent, but also precisely coaxially aligns the support members holding the stent at both ends during rotation to prevent run out of the stent. The holding device is designed to secure and rotate multiple stents simultaneously resulting in minimized damage during handling and high volume production of medical devices.
[0042] To transmit rotational and/or translational motion to the stent, the holding device is preferably coupled to a motion unit comprising one or more motors. FIG. 2 shows a mechanism to transmit rotary motion to the stent. The support members 6 are engaged with the stent 1 at two opposing sides so that the stent is securely held and can be rotated in relation to the frame. To avoid stress due to torsion during rotation of the stent, both support members are preferably driven from either side. The two support members 6 are connected with belts 20 to the shaft 19 and rotary motion is transmitted from one support member 6 or from the shaft 19 via belts to the other support member 6 . Alternatively, the shaft and the support member may be equipped with gears and rotary motion is transmitted via gears to the stent. Guide or lock section 21 is provided to secure the angular position of the holding device during rotation of the stent and to prevent revolving of the holding device.
[0043] The holding device of the present invention is designed to secure and rotate multiple stents simultaneously, as depicted in the schematic representation of FIG. 3 . Shaft 19 and six sets of support members 6 being connected to the shaft with belts 20 are rotably mounted to the frame 17 . Rotary motion is transmitted from the shaft 19 or from one of the support members 6 to the opposing support member to rotate six stents simultaneously about their longitudinal axis within the frame structure.
[0044] The holding device may be further equipped with sleeves, stop members and a coupling to facilitate mounting of the support members, to ensure a reproducible engagement position between the stent and the support members, and to easily engage and disengage the stent.
[0045] With reference to FIG. 4A and FIG. 4B , the sleeves 29 are rotably mounted to the frame and coupled via belts 20 to the shaft 19 to facilitate mounting and to transmit rotary motion to the support members. A magnetic coupling 35 is provided to couple the stop members 34 to the sleeves 29 . The stop members 34 , which are in contact with the support members 6 , define the securing position of the support members 6 in relation to the stent 1 , so that the stent can be contacted at a predetermined position. Thus, axial displacement of the support members is prevented and a reproducible positioning of the support members in relation to the stent is ensured.
[0046] In a first position, as illustrated in FIG. 4A and FIG. 4B , the support members are engaged with the stent 1 and the stop members 34 are coupled to the sleeves 29 to secure the stent 1 . Rotary motion is transmitted between the shaft 19 and the stent 1 via belts 20 , sleeves 29 , coupling 35 , stop members 34 , and support members 6 . In a second position, as depicted in FIG. 5A and FIG. 5B , at least one support member 6 is disengaged from the stent 1 to unload the stent. The arrangement comprising support member 6 and stop member 34 is displaced in axial direction to release the stent 1 . Alternatively, the position of the support members 6 may be determined by a lock member, such as a pin or a securing ring, which may be detachably coupled to the support members.
[0047] The holding device of the present invention can include support members of different types to securely hold stents of various sizes, designs and rigidity. The support members are designed to center the stent so that the longitudinal axis of the stent is coaxial with the rotation axis and to provide a stable connection during transmission of rotary motion. In order to prevent deposition of coating material on the stent holding device, the contact area between the support member and the stent is preferably minimized, namely limited to the edges and/or to a small section within the inner surface near the ends of the stent. At least a portion of the support member may be interchangeable to facilitate cleaning and adaptation to various medical devices and coating setups. FIGS. 6 to 9 illustrate exemplary support members used to secure stents.
[0048] Referring to FIG. 6A , an exemplary support member with mounted stent is shown. The support member is shown in more detail in FIG. 6B . In order to reduce the contact area between support member 6 and stent 1 while securely holding stent 1 , the support member comprises passages 9 at the portion contacting the inner section of the stent. To facilitate stent mounting, the tips of the support members are preferably rounded and can have a hemispherical shape. The portion contacting the inner surface of the stent may be detachably mounted to facilitate cleaning and allow adaptation to various stent sizes. The passages 9 have the shape of slots and are equally distributed on the circumferential surface of the support member. Crosspieces 8 are formed, which comprise the outer surface of the support member 6 and secure the stent by contacting its inner surface. To securely hold the stent, the portion of the support member contacting the inner surface of the stent comprises at least two sides being parallel to the longitudinal axis of the stent. The support members can be constructed from a suitable metallic material, such as stainless steel, titanium, cobalt chromium alloys, or a suitable polymeric material like Polyetheretherketone (PEEK). The passages 9 are preferably manufactured using a micro mill or a micro ECM and may have various shapes. Alternatively, the support members may be made from a folded sheet or be constructed from a hollow profile and may comprise passages.
[0049] To avoid defects on the surface of the stent due to coating residuals that may accumulate on the support member or between support member and stent, it is desirable to further minimize the contact area between stent and support member. FIG. 7 depicts a variation of the support member 6 described before. It comprises a structure 8 contacting the inner surface of the stent 1 . The structure, which may be made from a bended wire having a diameter between 0.3 and 0.8 mm, includes two contact sections being located parallel to the longitudinal axis of the stent.
[0050] Alternatively as shown in FIG. 8 , the structure may comprise edge 11 and the inner surface of the stent is in contact with the edge being parallel to the longitudinal axis of the stent.
[0051] Another exemplary support member designed to prevent coating defects by minimizing the area contacting the stent is illustrated in FIG. 9A , FIG. 9B and FIG. 9C . Referring to FIG. 9A , the support member includes a structure 53 at least partially surrounding one end of the stent 1 , and member 52 that is connected to the structure 53 at both ends and contacts the stent. The member 52 may consist of a rod or a thread and the like. To facilitate cleaning or replacement of the portion of the support member contacting the stent, the member is preferably detachably mounted to the structure. The member 52 may be coupled to the structure 53 by means of a clamping mechanism to facilitate mounting and to secure the member 52 . Alternatively, the member can be part of the structure. As shown in FIG. 9B and FIG. 9C , the member 52 may furthermore comprise at least one portion having a larger cross-section to center the stent. Referring to FIG. 9B , two spheres 55 may be provided to contact the inner surface of the stent. The spheres are preferably located equidistant from the longitudinal center axis of the support member to align the stent in relation to the support member. With reference to FIG. 9C , a rod 56 is provided to contact the inner surface of the stent. The ends of the rod are located equidistant from the longitudinal center axis of the support member to align the stent in relation to the support member. Thus, a run out of the stent is prevented by precisely aligning the stent axis in relation to the rotation axis.
[0052] FIG. 10 shows an exemplary stent holding apparatus and spray coating setup. For increased production output, the apparatus can be equipped with a larger frame to accommodate twelve support members to secure up to six stents. Its compact design allows the integration of two apparatuses in an isolator to coat twelve stents simultaneously. The holding device 30 , shown in detail in FIG. 4A , is detachably connected via coupling 23 to the drive shaft 26 of a motion unit 25 and mounted to guide member 24 at guide section 21 . It is aligned via guide sections 21 in relation to the guide member 24 . The longitudinal axis of the guide member 24 is preferably parallel to the longitudinal axis of the drive shaft 26 in order to align the holding device in relation to the motion unit 25 . The guide section 21 of the holding device 30 is connected to guide member 24 to secure the angular position of the holding device during rotation of the stents and to secure the holding device against revolving. The support members 6 are connected via shaft 19 to drive shaft 26 of motion unit 25 . To easily connect shaft 19 to drive shaft 26 , the drive shaft may be equipped with an automated clamping mechanism 23 . The support members 6 are engaged with the stent at two opposing sides and the stent is securely held and can be rotated in relation to the frame 17 . Stop members 34 are coupled to the sleeves 29 to secure the stent.
[0053] Rotational and translational movement is transmitted from the drive shaft 26 of motion unit 25 via coupling 23 to the shaft 19 of the holding device 30 . Rotational movement is transmitted to the stents 1 via shaft 19 , belts 20 , sleeves 29 , couplings 35 , stop members 34 , and support members 6 . The drive shaft translates the holding device 30 along the guide member 24 to move the stents 1 in a linear direction.
[0054] Alternatively, rotary motion can be transmitted from the motion unit to the support member and linear motion is transferred to the frame. In another embodiment, each support member may be connected to a dedicated motion unit that transmits linear and/or rotary motion to the stent.
[0055] Two atomizers 27 are provided to apply a coating composition to both stents at the same time. During the application of the coating, the holding device 30 is moved in a linear direction relative to the two atomizers 27 generating spray plume 28 , and the stents are rotated. The center axis of the spray plume 28 is preferably perpendicular to the rotation axis of the stents 1 and both axes are located on the same plane. After application of the coating, the holding device can be removed from the drive shaft 26 and guide member 24 to continue, for example, with further process steps like drying and inspection.
[0056] By using the holding device of the present invention it is not required to dismount and remount the stents. Thus, damage of the medical devices during handling and inspection can be prevented resulting in savings in time and cost. As shown in the exemplary inspection setup of FIG. 11 , the stent holding device 30 is connected to guide members 24 , which is coupled to a linear stage 33 . The stent 1 can be moved in the x-axis direction along guide members 24 and in the y-axis direction along linear stage 33 to position the stent in relation to a measurement and/or inspection apparatus. By turning the shaft 19 of the holding device along its c-axis, the stent 1 is rotated and the coating is inspected using a microscope 32 .
[0057] The following method of precisely aligning and transmitting rotary and/or linear motion to one or more stents using the apparatus of the present invention is being provided by way of illustration and is not intended to limit the embodiments of the present invention. Referring back to FIG. 10 , the stents 1 are mounted, and engaged with the support members 6 . The axial position of the support members 6 is secured by connecting the stop members 34 to the sleeves 29 . To check proper mounting of the stents the shaft 19 may be manually rotated. In another step, the holding device 30 with loaded stents 1 is placed on the guide member 24 . The holding device is slid along guide member 24 and is moved towards and connected to the drive shaft 26 of motion unit 25 . Rotary motion is transmitted from the drive shaft 26 via shaft 19 , belts 20 , sleeves 29 , and stop members 34 to the support members 6 , and the stents 1 are rotated about their longitudinal axis. To move the holding assembly along the guide member 24 in relation to the atomizers 27 , linear motion is transmitted from the motion unit 25 . A coating can be applied by spraying a coating composition using the atomizers 27 . After application of the coating, the shaft 19 is disconnected from the drive shaft 26 of motion unit 25 and the holding device is removed from the guide member 24 . The stents may remain mounted on the holding device to allow drying of the coating and subsequent inspection. One skilled in the art can appreciate that drying may be accomplished in a variety of ways based on the coating formulation used. To inspect the coating, the stent holding device 30 may be placed with mounted stent 1 on an inspection table 31 , as shown in FIG. 11 , and may be moved along the x-axis and/or y-axis to align the stent in relation to microscope 32 . The stent may be rotated about its longitudinal axis by turning the shaft of the stent holding device along its c-axis.
Stent Coating Example
[0058] The following example is being provided by way of illustration and is not intended to limit the embodiments of the present invention.
[0059] Stents (manufactured by STI, Israel) having a diameter of 2 mm and a length of 20 mm may be coated.
[0060] The coating composition may include a non-bioabsorbable or bioabsorbable polymer, a solvent capable of dissolving the polymer at the concentration desired in the composition, and a therapeutic substance.
[0061] The coating composition may comprise a solvent, a polymer, and a therapeutic substance. The therapeutic substance may include, but is not limited to, proteins, hormones, vitamins, antioxidants, antimetabolite agents, anti-inflammatory agents, anti-restenosis agents, anti-thrombogenic agents, antibiotics, anti-platelet agents, anti-clotting agents, chelating agents, or antibodies. Examples of suitable polymers include, but are not limited to, synthetic polymers including polyethylen (PE), poly(ethylene terephthalate), polyalkylene terepthalates such as poly(ethylene terephthalate) (PET), polycarbonates (PC), polyvinyl halides such as poly(vinyl chloride) (PVC), polyamides (PA), poly(tetrafluoroethylene) (PTFE), poly(methyl methacrylate) (PMMA), polysiloxanes, and poly(vinylidene fluoride) (PVDF); biodegradable polymers such as poly(glycolide) (PGA), poly(lactide) (PLA) and poly(anhydrides); or natural polymers including polysaccharides, cellulose and proteins such as albumin and collagen. The coating composition can also comprise active agents, radiopaque elements or radioactive isotopes. The solvent is selected based on its biocompatibility as well as the solubility of the polymer. Aqueous solvents can be used to dissolve water-soluble polymers, such as Poly(ethylene glycol) (PEG) and organic solvents may be used to dissolve hydrophobic and some hydrophilic polymers. Examples of suitable solvents include methylene chloride, ethyl acetate, ethanol, methanol, dimethyl formamide (DMF), acetone, acetonitrile, tetrahydrofuran (THF), acetic acid, dimethyle sulfoxide (DMSO), toluene, benzene, acids, butanone, water, hexane, and chloroform. For the sake of brevity, the term solvent is used to refer to any fluid dispersion medium whether a solvent of a solution or the fluid base of a suspension, as the invention is applicable in both cases.
[0062] The stents may be mounted on the holding device of the present invention as illustrated in FIG. 4A . Two air-assisted external mixing atomizers can be used to disintegrate the coating composition into fine droplets and apply the coating to the stents. Alternatively, ultrasonic nozzles, or dispensers can also be employed for the application of the composition.
[0063] The holding device may move in a linear direction along the guide member in relation to the atomizers and may rotate both stents simultaneously at the same angular velocity. The two spray nozzles can disintegrate the coating solution into fine droplets at a liquid flow rate of about 0.1 to 80 ml/h and an atomizing pressure ranging from about 0.3 to about 1.5 bar. In order to achieve a fine atomization, the nozzles are preferably operated at an atomizing gas flow rate of 5 l/min and at an atomizing pressure of 0.8 bar. The nozzles generate droplets having a volumetric median diameter between approximately 2 and 7 microns and a largest droplet diameter of less than 20 microns. For best results, the spray axis of the atomizer is preferably perpendicular to the rotation axis of the stent and both axes are in the same plane. The spray nozzles may be positioned at a distance of approximately 12 to 35 mm from the nozzle tip to the outer surface of the stent.
[0000] A syringe pump, which is operated at a constant flow rate, can be used to feed the coating substance to the atomizer. The flow rate of the coating solution may range from about 1 to 50 ml/h and is preferably 5 ml/h
[0064] During the application of the coating solution, rotary motion is transmitted from the drive shaft of the motion unit to the stents to rotate the stents about their central longitudinal axes. The rotation speed can be from about 5 to about 250 rpm. By way of example, the stent may rotate at 130 rpm. The stents are translated along their central longitudinal axes along the atomizers. The translation speed of the stents can be from about 0.2 to 8 mm/s. When applying the coating solution, the translation speed is preferably 0.5 mm/s. The stents can be moved along the atomizer one time to apply the coating in one pass or several times to apply the coating in several passes. Alternatively, the atomizer may be moved one time or several times along the stent length.
[0065] Coating trials of several stents were performed. FIG. 12 shows a portion of a stent coated using the holding device of the present invention. The number of coating defects, especially at the ends of the stents, was reduced by using the holding device of the present invention.
[0066] While the invention will be described in connection with certain embodiments, it will be understood that the invention is not limited to these embodiments. On the contrary, the invention includes all alternatives, modifications and equivalents as may be included within the spirit and scope of the present invention. Details in the Specification and Drawings are provided to understand the inventive principles and embodiments described herein, to the extent that would be needed by one skilled in the art to implement those principles and embodiments in particular applications that are covered by the scope of the claim.
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This invention relates to a multi-purpose holding device to handle, support and rotate one or more hollow cylindrical objects. The holding device consists of a rigid frame and support members for precise alignment and rotation of one or more objects within the frame structure. A method is also provided to reproducibly support, rotate and inspect the hollow cylindrical objects.
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BACKGROUND OF THE INVENTION
The present invention relates to a looper for use in an overlocking sewing machine, and more particularly to a double-purpose looper capable of forming overlocked stitches with one needle and two threads and one needle and three threads.
Conventional overlocking sewing machines for producing overlocked stitches with one needle and three threads include a sewing needle, a lower looper and an upper looper secured to a looper holder, which cooperate to form such overlocked stitches. Overlocking sewing machines for forming overlocked stitches with one needle and two threads have a sewing needle, a lower looper and a spreader, which are cooperatively actuatable to produce such overlocked stitches.
In the conventional machine, as many differently shaped loopers and spreaders are needed as the stitches produced by their use. Formation of overlocked stitches with one needle and three threads or one needle and two threads on a single sewing machine requires two different loopers which are to be replaced with each other as demands dictate, an arrangement which is quite tedious and time-consuming.
Recently, as seen in U.S. Pat. No. 4,237,804 a sewing machine was proposed for stitching fabric edges with an overlocked stitch with one needle and three threads, the sewing machine including an upper looper and a separate movble member attached thereto, which together define a hook portion for overcasting a fabric edge with one needle and two threads as with a single spreader. When forming overlocked stitches with one needle and three threads, the movable member is brought away from the upper looper to release the hook portion and allow the upper looper to function as intended. In this machine, the combined hook portion moves along the same path as that of the upper looper when forming overlocked stitches with one needle and three threads, so that the hook portion and the upper looper will meet a lower looper at the same position to produce the respective stitches. The separate movable member which is necessary to cooperate with the upper looper in providing the combined hook portion for formation of overlocked stitches with one needle and two threads must be retracted, when not in use, into a position in which the movable member does not interfere with operation of the sewing machine, and hence a space must be reserved for retracting the movable member therein. Furthermore, when the combined hook portion picks up a thread from the lower looper, the thread therefrom tends to be caught in a gap defined between the upper looper and the separate movable member.
Thus, the known overlocking sewing machines even with the combined hook portion upper looper and movable member, are unable to form overlocked stitches of at least two types, reliably and smoothly, while permitting the change between stitch types to be quickly made.
It is therefore an object of the present invention to solve the foregoing problems encountered with the prior apparatus by providing a single looper element which enables the production of both one needle, three thread overlocked stitches and one needle, two thread overlocked stitches upon cooperation with a needle and a lower looper in a sewing machine.
This object and other objects, features and advantages of the present invention will become apparent from the following description when considered in connection with the accompanying drawings.
SUMMARY OF THE INVENTION
In general, the objects and advantages of the present invention are achieved by providing an improved looper having a unitary distal portion which serves as an upper looper and as a spreader, thus serving the functions of two different elements. In the present invention, the upper portion of the distal portion of the improved looper serves as an upper looper to produce overlocked stitches with one needle and three threads while the lower portion of the distal portion of the improved looper serves as a spreader for producing overlocked stitches with one needle and two threads. The unitary distal portion of the improved looper, includes upper and lower distal end portions jointly defining a hook portion therebetween. The hook portion can be considered to be a spreader portion which is operable to function as a spreader as described herein. The unitary distal portion preferably is curved toward the lower looper in the sewing machine, and is operable with a sewing needle and a lower looper, both of which are capable of carrying threads for the selective production of overlocked stitches with one needle and three threads or one needle and two threads. The improved looper of the present invention preferably includes an aperture in its unitary distal portion which is capable of supporting a thread for movement with the looper.
The improved looper of the invention is supported by holder means, preferably a looper holder, which in turn is mounted to driving means for the looper for movement therewith. The supporting of the improved looper to the holder means and to the driving means is accomplished at least in part by positioning means mounted on said holder means or said driving means for selectively positioning the improved looper with its unitary distal portion with respect to the driving means in a first or second position at which the looper driving means drives the looper along different paths, and thereby meets the lower looper at different positions. In its first position, the unitary distal portion of the improved looper is moved by the driving means along a first path and in its second position the unitary distal portion is moved along a second path. As will be hereinafter described, the positioning of the improved looper with its unitary distal portion in either of the two positions and moving the portion along the respective paths will determine the formation of overlocked stitches with either one needle and three threads or one needle and two threads.
Upon movement along one of its two paths, the improved looper, in cooperation with a needle carrying a thread and a lower looper also carrying a thread, will serve as an upper looper to pick up the lower looper thread for producing, with a third thread carried by it, overlocked stitches with one needle and three threads; while upon movement along the other of its two paths, the improved looper, again in cooperation with the needle and lower looper, each carrying a thread, will serve as a spreader having a front hook portion to catch and retain the lower looper thread for forming overlocked stitches with one needle and two threads.
More specifically, the improved looper in the first position is movable to cause the distal or hook portion to move along one path across the lower looper for forming, with a thread carried by the improved looper, an overlocked stitch with one needle and three threads, and the improved looper in the second position is movable to cause the distal or hook portion to move along a second path across the lower looper so as to pick up and spread a lower thread loop from the lower looper for forming an overlocked stitch with one needle and two threads.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a front elevation view of a double purpose looper according to the present invention;
FIG. 2 is a side elevation view of the looper of FIG. 1;
FIG. 3 is a top view of the looper shown in FIG. 1;
FIG. 4 is a front elevation view of the looper of FIG. 1, showing several related elements, and illustrating the paths along which the looper is moved and positions of the looper therealong in broken lines;
FIG. 5 is a front elevation view of another embodiment according to the present invention illustrated as in FIG. 4;
FIG. 6 is a side elevation view of the looper shown in FIG. 5;
FIG. 7 is a top view of the looper of FIG. 5;
FIG. 8 is a front elevation view of the looper of FIG. 5 illustrating supporting elements and a portion of the driving means for the looper of the present invention;
FIG. 9 is an enlarged front elevation view illustrating one step in the formation of a three thread stitch with the looper of the present invention;
FIG. 10 is an enlarged front elevation view of another step in the formation of a three thread stitch with the looper of the present invention;
FIG. 11 is an enlarged front elevation view of still another step in the formation of a three thread stitch with the looper of the present invention;
FIG. 12 is an enlarged side elevation view illustrating one step in the formation of a two thread stitch with the looper of the present invention;
FIG. 13 is an enlarged front elevation view of another step in the formation of a two thread stitch with the looper of the present invention; and
FIG. 14 is an enlarged front elevation view of still another step in the formation of a two thread stitch with the looper of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings where like elements have the same reference numbers, and specifically to FIGS. 1-4, the numeral 20 designates generally a looper constructed in accordance with the present invention, the looper having a unitary distal end portion bifurcated with upper and lower distal end portions 21, 22 which jointly define a hook portion 23 therebetween. Lower distal end portion 22 and hook portion 23 serve as a spreader portion to catch and retain lower looper thread 56, (FIG. 14), so as to assist in forming overlocked stitches with one needle and two threads. Upper looper portion 33 formed by upper distal end portion 21 having an upper surface 34 of said unitary distal portion serves as an upper looper to produce overlocked stitches with one needle and three threads. The upper distal end portion 21 has adjacent thereto in suitable position in looper 20 an aperture 24 for passage of a thread therethrough. The distal end portions are curved toward the back of a lower looper 27 as shown.
As best illustrated in FIGS. 2 and 3, looper 20 has a mounting flange 25 on one side of a rear or lower portion of the looper, flange 25 in this embodiment having an elongated aperture, preferably a slot, 26 extending longitudinally of the flange.
As shown in FIG. 4, the lower looper 27 is angularly movable about a shaft (not shown) disposed downwardly thereof for reciprocal movement in the directions of the arrows 28. A sewing needle 29 is movable downwardly in front of the lower looper 27 as it is withdrawn. The lower looper 27 has in its distal end an aperture 30 for passage of a thread therethrough.
Designated in FIG. 4 as 31 is a looper holder on which is mounted the flange 25 of the looper 20. The looper 20 is secured to the distal end portion of (as shown) looper holder 31 by a screw 32 extending through the elongated slot 26 into a threaded hole in the looper holder 31 in at least two positions which are determined by the positioning of the flange 25 on the looper holder, and screw 32 in slot 26. To selectively position looper 20 in position for the formation of overlocked stitches with one needle and three threads, the looper 20 is first moved forward toward the lower looper 28 into the solid-line position illustrated in FIG. 4 until the right end of the elongated aperture 26 abuts against the screw 32. The looper 20 is then fixed to the looper holder 31 by tightening the screw 32. In order to selectively position looper 20 in position for the formation of overlocked stitches with one needle and two threads, the screw 32 is loosened to allow the looper 20 to be retracted on the looper holder 31 until the left end of the elongated aperture 26 abuts against the screw 32. Then, the screw 32 is tightened to fix the looper 20 to the looper holder 31.
FIGS. 5-8 illustrate another embodiment of the present invention, reference numeral 40 generally designating the improved looper thereof with its unitary distal end portion. The unitary distal end portion of looper 40 is bifurcated with upper and lower distal portions 21, 22 jointly defining a hook portion 23 therebetween, and is curved toward the back of the lower looper 27. The looper 40 includes an aperture 24 for receiving a thread in the manner described above. Further in this embodiment, looper 40 is mounted on a looper holder 41, which in turn is fixedly mounted to an elongated member 42 of the looper driving means. Thus, whereas in the first embodiment, the elongated member served as the looper holder 31 to which looper 20 was mounted, in this embodiment the flanged member 41 serves as the looper holder to which looper 40 is mounted and which in turn is mounted on the elongated member 42.
Looper 40 has in its portion distant from the unitary distal end described above, a horizontally elongated aperture 43 through which a screw 44 extends into threaded engagement in a threaded hole in the looper holder 41. The looper 40 can be selectively positioned thereon by advancing the looper 40 to a first position or retracted to a second position upon loosening the screw 44, and can be secured in place in the first or second position by tightening the screw 44. To selectively position looper 40 in position for the formation of overlocked stitches with one needle and three threads, the looper 40 is displaced toward the lower looper 27 into the first solid-line position, in which the looper 40 is fastened by the screw 44. In order to selectively position looper 40 in position for the formation of overlocked stitches with one needle and two threads, screw 44 is loosened to allow looper 40 to be retracted on looper holder 41 away from lower looper 27, and the screw 44 then tightened.
FIG. 8 shows apparatus for driving a looper of the present invention. Although looper 40 is utilized in FIG. 8, the apparatus applies as well to looper 20. The driving apparatus comprises a drive shaft 45 located in a lower portion of the sewing machine, a crank 46 fixed to the shaft 45, and a swingable lever 47 connected at its distal end to one end of a connector link 48 by a pin 49. The other end of connector link 48 is connected by a pin 50 to an end of the crank 46. The swingable lever 47 is connected at its proximal end thereof to a shaft 51 rotatably journalled in a bearing (not shown) disposed downwardly of a bed of the sewing machine.
The looper holder 31 in the embodiment of FIGS. 1-4 is in the form of an elongated rod to which flange 25 is mounted, whereas in FIG. 8 the elongated member 42 is an element of the driving apparatus. Thus, looper holder 31 can be considered in relation to FIG. 8 as 42 and, like member 42, as having a lower end rotatably coupled to pin 49 and having an intermediate portion slidably inserted through a guide hole 52 in a guide member 53 that is angularly movably mounted on shaft 54 attached to a support (not shown) disposed downwardly of the sewing machine bed.
When the drive shaft 45 rotates, the lever 47 is caused by the connector link 48 to turn about the shaft 51, whereupon the elongated member 42 moves up and down as it swings about the shaft 54 causing the upper and lower distal ends 21, 22 of the looper to follow the path a or b shown in FIGS. 4 and 5.
The manner in which the looper 20, 40 of the invention is utilized to form an overlocked switch with one needle and three threads will now be described.
With the looper 20, 40 selectively positioned in the first solid line position in FIGS. 4 and 5, as described above, an upper thread 55 is threaded through the hole 24 in the looper 20, 40, a lower thread 56 is threaded through the hole 30 in the lower looper 27, and a sewing thread 57 is threaded through a thread hole in the sewing needle 29.
As the sewing machine is put into operation, the upper distal end portion 21 of the looper 20, 40 moves along the path a as the distal end portion 21 traverses the lower looper 27. At this time, the upper distal end portion 21 passes under the lower thread 56 as shown progressively in FIGS. 9, 10 and 11, and is raised with the lower thread 56 carried on upper surface 34. The looper 20, 40 continues to move upwardly to pass the upper thread 55 extending through the hole 24 under the lower thread 56 and until the upper thread 55 meets the sewing needle 29. The upper thread 55 is now caught by the sewing needle 29 as the latter is lowered. Thereafter, the looper 20, 40 is moved downwardly and the lower looper 27 is retracted forming an overlocked stitch with one needle and three threads (Japanese Industrial Standards: Classification B9070, Identification E13, E13A).
The manner in which the looper 20, 40 of the invention is utilized to form an overlocked stitch with one needle and two threads will now be described.
The looper is retracted to the second, broken line position in FIGS. 4 and 5 and secured in that position as heretofore described. In this position, the driving apparatus will cause the upper distal end portion 21 and hook portion 23 to follow the path b across the lower looper to form an over-locked stitch with one needle and two threads.
The sewing machine is operated with the lower thread 56 and the needle thread 57, but without the upper thread 55 in the looper 20, 40. The hook portion 23 of the distal portion of the looper 20, 40 as it moves upwardly picks up the lower thread 56 extending through the lower looper 27 as shown successively in FIGS. 12, 13 and 14. The looper 20, 40 continues to move upwardly with the lower thread 56 retained in hook portion 23, i.e. between the distal end portions 21, 22, and more particularly by lower distal end portion 22 as shown in FIG. 14, until the lower thread 56 is taken by the sewing needle 29 as the latter descends. The looper 20, 40 and the lower looper 27 are then retracted to form an overlocked stitch with one needle and two threads (Japanese Industrial Standards: Classification B9070, Identification E12, E12A).
Stated otherwise, the upper distal end portion 21 of the looper 20, 40 moves along the path b which is different from the path described by the upper distal end portion 21 as it is in the first position, as shown in FIGS. 4 and 5, and hence the upper distal end portion 21 does not move into the lower thread 56 carried by the lower looper 27. Instead, the lower distal end portion 22 portion follows a path b', as illustrated in FIG. 12, to pick up the lower thread 56, thus producing an overlocked stitch with one needle and two threads.
The looper 20, 40 of the present invention can be attached to the looper holder 31, 41, respectively, at front and rear positions with little difficulty, such that the looper will move across the lower looper 27 at different positions. When the looper 20, 40 is in the forward position, the looper serves as an upper looper in a sewing machine for forming overlocked stitches with one needle and three threads, and when the looper 20, 40 is in the rearward position, the looper serves as a spreader in a sewing machine for producing overlocked stitches with one needle and two threads. The arrangement of the present invention is highly advantageous in that it can form two kinds of overlocked stitches without the expense of having two different looper elements as with earlier sewing machines.
With the present invention, as described above, the unitary looper 20, 40 is easily movable from the first to the second position or vice versa in order to cause the distal end portions 21, 22 of the distal or hook portion to traverse the lower looper at different positions for the formation of overlocked stitches with one needle and two threads or one needle and three threads.
While in the illustrated embodiments the looper 20, 40 has been shown as being movable generally horizontally, it may be arranged so as to move generally vertically between first and second positions, and various manners of movement such as angular movement or sliding movement may be employed for shifting the looper.
The looper 20, 40 moves across the lower looper 27 at different positions simply by changing paths of movement of the distal or hook portion of the looper 20, 40. The arrangement of the invention is advantageous in that no additional member for defining a hook portion with the upper looper is needed resulting in smooth and reliable formation of overlocked stitches, a construction which is different from conventional arrangements in which upper loopers move along a single, fixed path. Since there is no need for reserving an additional space for withdrawing therein a separate member out of interference with the operation of the machine for forming overlocked stitches with one needle and three threads, as with the recently proposed apparatus, the present invention is readily applicable to small-size sewing machines having limited space available therein.
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A looper for a sewing machine capable of making overlocked stitches has a unitary distal portion which is operable for the selective production of overlocked stitches with one needle and three threads or one needle and two threads. The unitary distal portion of the looper includes an upper looper portion and a spreader portion. A holder is provided in connection with driving means for supporting the looper, and a positioning arrangement is provided to selectively position the unitary distal portion of the looper in a first position for movement along a first path or in a second position for movement along a second path for the selective production of the stitches.
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This application is a continuation-in-part of application Ser. No. 08/157,139, filed on May 5, 1993.
FIELD OF THE INVENTION
This invention relates generally to an improved system for indicating the size of a garment suspended from a garment hanger. Specifically, this invention relates to an improved system for easily indicating the sizes of garments on hangers in retail outlets. Structurally, a garment hanger is equipped with a size-indicating tab that cannot be easily removed from the hanger after it is attached thereto. The tab and tab-holder mounted on the hanger are of an improved ergonomic design that reduces the likelihood of carpal tunnel syndrome in assembly-line workers who attach the tabs to the hangers.
BACKGROUND OF THE INVENTION
The concept of a garment hanger that includes a label indicating the size of the garment hung thereon is well-known. However, modern safety standards require a size-indicating tab to be irremovable once installed on a hanger. From the standpoint of safety, if a small tab can be easily removed from a hanger, it may become lodged in a child's throat. But another problem has arisen in wake of the development of permanently attached size-indicating tabs. Specifically, the tabs are difficult to attach to the hangers and assembly-line workers may develop carpal tunnel syndrome as a result of installing the tabs on the hangers.
By way of background, retail stores have used hangers indicating the size of the garment for a long time. Examples of patented size-indicating garment hangers and/or size-indicating labels for garment hangers include the following U.S. Pat. Nos.: 1,321,926; 1,389,266; 3,535,808; Des. 244,197; 3,949,914; 4,997,114 and 4,115,940. Each of the above references include some sort of tag or label attached to the hanger that is visible to the consumer as he/she browses through racks of clothes in a retail store. Because many garments are sold with the hanger, the hangers often find their way into the homes of consumers. Because the tabs disclosed in the above references may be removed from the hangers, sometimes with surprising ease, the tabs have caused injury to young children who have a tendency to put small items in their mouths. The tabs can become lodged in the throat of a child inflicting serious injury or suffocation.
Therefore, the garment hanger industry began to develop size-indicating tabs that could not be easily removed from garment hangers. One such example is found in U.S. Pat. No. No. 5,096,101. This patent discloses a plastic tab that is forced over a tab holder that includes two triangular cross-sections. The U-shaped tab includes two inwardly protruding ends and two projections. Both the ends and the projections are captured underneath the enlarged regions of the triangular cross-sections. The result is a double-locking tab that cannot be removed from the hanger without substantially damaging or destroying the tab.
However, it will be noted that the tab disclosed by the 5,096,101 patent is rather difficult to attach to the tab holder. Specifically, the assembly-line worker must firmly grasp the tab and impart undue amounts of twisting and pushing forces on the tab to push it over both triangular cross-sections and into the locking position. Because the assembly-line worker must firmly grasp the tab and thereafter firmly press the tab inward or downward on the hanger to lock the tab into place, the probabilities for the occurrence of carpal tunnel syndrome are increased.
Carpal tunnel syndrome is a common nerve disorder affecting the hands, wrist and forearm of its victims. Specifically, carpal tunnel syndrome results from the compression of the median nerve at the wrist, within the carpal tunnel. The carpal tunnel acts as a conduit for important nerves, blood vessels and tendons extending through the wrist to the thumb and fingers. The compression of nerves in the carpal tunnel causes sensory and motor changes in the median distribution of the hand. Carpal tunnel syndrome usually occurs in women between ages 30 and 60 and poses a serious occupational health problem. Assembly-line workers, packers and persons who repeatedly use poorly designed tools are most likely to develop this disorder. Any strenuous use of the hands, including sustained grasping, twisting or turning, may aggravate this condition.
Difficult-to-install tabs like the ones shown in U.S. Pat. No. 5,096,101 may contribute to the development of carpal tunnel syndrome in assembly-line workers. Therefore there is a need for an improved size-indicating tab that is easier for the assembly-line worker to install on the garment hanger. The size-indicating tab must also include the non-removable aspects previously known so as to not create a child-safety problem.
SUMMARY OF THE INVENTION
The present invention makes a significant contribution to the garment hanger art by providing an improved size-indicating system. The hanger resulting from the present invention is safe for use in homes with small children and further is easy to manufacture and avoids requiring the assembly-line worker to perform an excessive amount of grasping, twisting or turning which may lead to the development of carpal tunnel syndrome.
The improved garment hanger includes a hang means connected to a middle portion of a garment support member. The tab-holding section is preferably mounted to one side of the hook or hang means where the hang means is connected to the garment support member. The tab-holding section includes a wall that is preferably connected to both the hang means and the garment support member. The wall extends outwardly toward the consumer as the garment and hanger are hung from a rack. The wall terminates at a bullet-shaped member which serves as a male connector for the tab. The bullet-shaped member is connected to the end of the wall at the base of the bullet-shaped member.
The improved size-indicating tab of the present invention is preferably U-shaped. A front end of the tab is disposed between two side members. The opposing side members extend away from the consumer and terminate in two inwardly curved ends. The front end of the tab serves as a rigid hinge connection between the two opposing side members and the outer front wall of the front end serves as a space for indicating the size of the garment.
When the tab is installed on the tab-holding section of the hanger, the front display wall, indicating the size of the garment, faces outward or frontward, toward the consumer. In a relaxed position the two inwardly curved ends of the tab are separated by a distance. This defined distance is approximately equal to the thickness of the wall that connects the bullet-shaped member to the hanger. When the tab is inserted over the bullet-shaped member, the inwardly curved ends extend past the base of the bullet-shaped member and snap inward toward their relaxed position and either positively engage or at least abuttingly engage the wall which connects the bullet-shaped member to the hanger.
In the preferred embodiment, the inwardly curved ends of the opposing side members of the tab are further characterized as terminating in substantially flat inner walls that engage the wall that connects the bullet-shaped member to the hanger. Each flat inner wall of a curved end is disposed between a rounded edge and a relatively square edge. The rounded edge is the distal or outermost portion of the tab and provides a smooth engagement between the tab and the narrow front end of the bullet-shaped member when the tab is pushed over the bullet-shaped member during installation of the tab. The square edge of each inwardly curved end is disposed adjacent to the base portion of the bullet-shaped member after the tab is installed. The engagement of the square edges of the curved ends of the tabs with the base portion of the bullet-shaped member precludes removal of the tab from the hanger without substantially damaging or destroying the tab.
Thus, a practically unremovable size-indicating tab is provided that is also easy to install. The rounded outermost edges of the tabs slide easily over the smooth bullet-shaped connecting member and do not require an excessive amount of strain, grasping or twisting action on the part of the assembly-line worker. Further, the relatively square edge disposed opposite the inwardly facing wall of the curved end is accommodated or captured underneath the base portion of the bullet-shaped member. To remove the tab from the tab-holding section, both square edges of the tab must be pulled outward and around the steps presented by the connection of the base portion of the bullet-shaped member to the wall which connects the bullet-shaped member to the hanger. Thus, both curved ends must be substantially spread apart and pulled off simultaneously. This complicated action is not within the mechanical skills of small children and therefore the size-indicating tab of the present invention does not present a child-safety threat.
It is therefore an object of the present invention to provide an improved size-indicating tab for garment hangers.
Another object of the present invention is to provide an improved size-indicating tab for garment hangers that is easier for assembly-line workers to install thereby reducing the risk of carpal tunnel syndrome in the workers.
Yet another object of the present invention is to provide an easy-to-install size-indicating tab that may also be used in homes with small children without creating any substantial risk to the safety of the children.
BRIEF DESCRIPTION OF THE DRAWINGS
This invention is illustrated more or less diagrammatically in the accompanying drawing, wherein:
FIG. 1 is a partial front elevational view of a garment hanger, tab-holder and tab made in accordance with the present invention;
FIG. 2 is a section view taken substantially along line 2--2 of FIG. 1;
FIG. 3 is the same section view shown in FIG. 2 illustrating the tab as it is being initially inserted over the tab holder;
FIG. 4 is the front elevation view of the tab showing the front display wall thereof;
FIG. 5 is an end view an alternative tab made in accordance with the present invention; and
FIG. 6 is a sectional view illustrating the alternative tab prior to insertion over an alternative tab holder, also made in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Like reference numerals will be used to refer to like or similar parts from Figure to Figure in the following description of the drawing.
As seen in FIG. 1, the garment hanger 10 includes a hang means 11 which is connected to the garment support member 12. In the retail environment, the distal end 13 of the hang means 11 is hung over a rack and is directed away from the consumer. Therefore, the size-indicating tab 24 is directed outward, toward the consumer. The tab-holding section, indicated generally at 15, (see FIGS. 2 and 3) is preferably connected to both the hang means 11 and the garment support member 12.
Referring to FIGS. 1 through 3 collectively, the tab-holding section 15 includes a wall or base member 16 which is connected to the garment support member 12 and the hang means 11. The wall or base member 16 is connected to the bullet-shaped member, also known as a seat member, 17 at the base portion 18 thereof. In the preferred embodiment, outwardly extending ribs 21, 22 may be disposed on the wall 16 to provide structural support and block access to the tab 24 after installation. Upper and lower ribs 51, 52 respectively also block access to the tab 24 after installation. The bullet-shaped member terminates at a narrow front end 23.
The size-indicating tab 24 engages the tab-holding section 15 as seen in FIG. 3. The tab 24 includes two opposing side members 25, 26. Both opposing side members 25, 26 are attached to the front end 27 of the tab 24. The front end 27 includes a front display wall 28 and a slot or bright 29 for accommodating the front end 23 of the bullet-shaped member or seat member 17.
The opposing side members 25, 26 terminate in two inwardly curved ends 31, 32. The inwardly curved ends 31, 32 feature rounded edges 33, 34, inwardly facing walls 35, 36 and square edges 37, 38.
As the tab 24 is inserted over the bullet-shaped member 17, the rounded edges 33, 34 initially engage the front end or nose 23 of the bullet-shaped member. The rounded configuration of the edges 33, 34 along with the general rounded configuration the front end 23 of the bullet-shaped member 17 make it easy to slide the curved ends 31, 32 of the tab 24 over the bullet-shaped member 17. It will be noted from FIGS. 1 and 2 that the distance between the inwardly facing walls 35, 36 of the tab 24 is generally about the same thickness as the wall 16 and the distance between the inwardly facing walls 35, 36 is substantially less than the average thickness of the bullet-shaped member and substantially less than the thickness represented by the base portion 18 of the bullet-shaped member 17. Thus, the tab 24 must be made of some resilient material, such as plastic or other thermoplastic materials, and must be forced over the bullet-shaped member 17.
The rounded edges 33, 34 and the rounded configuration of the bullet-shaped member 17 enables the tab 24 to be inserted over the bullet-shaped member 17 with a minimum of effort. Once the tab 24 is pushed past the bullet-shaped member 17, the inwardly facing walls 35, 36 are accommodated in the receiving sections 41, 42 that are disposed between the ribs 21, 22 and the base portion 18 of the bullet-shaped member 17. Any attempt to pull the tab 24 out of the tab-holding section 15 will result in the engagement of the square edges 37, 38 against the square edges 43, 44 of the base portion 18 of the bullet-shaped member 17. Thus, to remove the tab 24 from the tab-holding section 15, the opposing side members 25, 26 must be grasped, spread apart so that the flat inner walls 35, 36 of the inwardly curved end portions 31, 32 clear the edges 43, 44 of the base portion 18 of the bullet-shaped member 17. This sort of simultaneous grasping and pulling requires dexterity that is beyond the capabilities of small children.
Referring to FIGS. 2, 3 and 4 collectively, the tab 24 includes 3 areas for the display of the garment size. The front display wall 28 extends frontward or outward and faces the consumer as the consumer browses along full racks of clothes in a retail store. Outer side walls 45, 46 also provide a place to display the size of the garment.
Thus, a new sizing system is provided for the garment industry which reduces the aggravation and strain associated with carpal tunnel syndrome as well as providing a hanger that is safe for use in homes with small children. The tab 24 may be installed by pushing inward or in a plane represented by the front end 23 of the bullet-shaped member and the wall 16 or, the tab 24 may be inserted using a rolling action made easier by the rounded edges 33, 34 disposed at the distal ends of the side members 25, 26 of the tab 24. The accommodation of the front end 23 of the bullet-shaped member 17 in the slot or bight 29 in combination with the flat inwardly facing walls 35, 36 of the curved end portions 31, 32 provides rocking-free stability of the tab once installed on the hanger. The stability afforded by the installed tab 24 also precludes removal of the tab 24 from the hanger 10.
Because the opposing side members or side walls 25, 26 would have to be stretched substantially outward in order to remove the tab 24 from the hanger 10, the tab 24 would be substantially damaged and rendered useless if it were successfully removed. Rendering the tab 24 useless after one removal ensures that worn or structurally tired tabs 24 will not be installed on hangers 10 which may find their way into the homes of consumers with small children. The structure of the tab 24 ensures that it will be used only once.
FIGS. 5 and 6 illustrate additional embodiments of the tab 24a and tab-holding section 15a respectively. Referring first to FIG. 5, the sections 61a, 62a disposed between the slot 29a and the side members 25, 26 has been flattened. Referring to FIG. 5, instead of the rounded ribs 21, 22 as shown in FIGS. 2 and 3, squared ribs 21a, 22a are employed. The bullet-shaped member 17a is also slightly wider than the bullet-shaped member 17 shown in FIGS. 2 and 3. Like reference numerals with the suffix "a" are used to identify the remaining elements which are discussed above in connection with FIGS. 4 and 5.
Although only two preferred embodiments of the present invention has been illustrated and described, it will at once be apparent to those skilled in the art that variations may be made within the spirit and scope of the present invention. Accordingly, it is intended that the scope of the present invention be limited solely by the scope of the hereafter appended claims and not by any specific wording in the foregoing description.
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A combination garment hanger and garment size indicating system is provided in the form of a garment hanger equipped with a tab-holding section that accommodates a size-indicating tab. Once the size-indicating tab is inserted into the tab-holding section, it is substantially unremovable. Any removal of the tab from the tab-holding section substantially damages the tab and renders it useless. The tab is ergonomically designed to reduce the likelihood of carpal tunnel syndrome in assembly-line workers charged with the task of installing the tabs on garment hangers.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to structured trading card display kits. More particularly, the kits are provided for creating an organized showing of trading cards, with the cards being structured around specific indicia for each kit. The kits may or may not include the required trading cards therein.
2. Prior Art
Heretofore, various means for storing and/or displaying trading cards have been proposed. However, such means have proffered no structuring or organization in how the cards are displayed. Typically, the cards are merely merged haphazardly into a framed collage with no rhyme or reason thereto.
SUMMARY OF THE INVENTION
Accordingly, there is a need for a structured, organizational kit by means of which trading cards relating to particular indicia can be collected and displayed together, with or without informational data presented therewith.
These as well as other objects are met by the organizational structured trading card display kit comprising a frame, glass surrounded by and seated within the frame, a mat, a backing, and a second piece of glass, the mat being sandwiched between the pieces of glass, and the mat having a predefined number of cutouts therein, the number of cutouts being defined by indicia selected for which cards are to be displayed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective blown apart view of one embodiment a kit made in a accordance with the teachings of the present invention.
FIG. 2 is a side view through a second embodiment of a kit made in accordance with the teachings of the present invention.
FIG. 3 is a frontal view of a third embodiment of a kit made in accordance with the teachings of the present invention.
FIG. 4 is a frontal view of a fourth embodiment of a kit.
FIG. 5 is a frontal view of a fifth embodiment of a kit made in accord etc.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings in greater detail, there are illustrated therein various exemplary embodiments of the organizational trading card display kit made in accordance with the teachings of the present invention and generally identified by the reference numeral 10 . These exemplary embodiments should not be construed as limiting.
Each kit includes at least a frame 12 within which an inset glass plate 14 is nested. Behind the glass plate 14 is positioned, a mat 16 , which is of a thickness at least equal to, if not slightly greater than the thickness of a trading card 18 . Pinioning the mat 16 against the framed glass 14 is a second piece of glass 20 followed by a backing 22 which is releasable secured to the frame 12 in a manner compressing the glass 20 against the mat 16 which is, in turn compressed against the glass 14 .
The mat 16 includes a plurality of cutouts 24 therein each of which is sized and configured to snugly receive a trading card 18 therein. The number of cutouts 24 in each mat 16 is based on the indicia for the particular display kit 10 , as will be defined below.
Also provided are a plurality of blanks 26 created when the cutouts 24 are formed, equal in number to the number of cutouts 24 with the blanks 26 obviously fitting snugly into the cutouts 24 .
The above structures define the display kit 10 in its most simplistic form. However, this should not be construed as limiting.
For example, the display kits 10 may be provided for a collector to place his own cards in or, alternatively, if desired, the display kits 10 may also include the trading cards 18 pertaining to the particular kit 10 .
Turning now to the indicia for each display kit 10 , and using sports trading cards 18 as the example, such indicia may be, for example “1976 OAKLANd RAIDERS”; “JERSEY #31”, “BASKETBALL HALL OF FAMERS”; “OLYMPIC GOLD MEDALISTS-SKATING”; “HOME RUN HALL OF FAMERS”; “QUARTERBACK”; “JOE NAMATH”; “BLACK Hawks-1999”; “Babe Ruth-career”; “Soccer Hall of Framers”; “STEEL Curtain”; ad infinitum.
Further, whenever “STAT CARDS” 30 , cards bearing statistics, such as for a particular player, or “ROSTER Cards” 30 , such as for a team for a particular year, are available, these will also be accommodated for in each display kit 10 .
Still further, where no such cards 30 are available for a particular index, a tag 32 bearing a title for the collection being displayed will be provided as shown in FIG. 5 . However, this will not preclude use of a tag 32 even when a card 30 is available, as shown in phantom in FIG. 3 .
Still further, it is proposed to provide a mat 16 and frame 12 which may display “team colors” when a particular team is in the index for the collection, as shown in FIG. 4 . Here, the frame 12 is shown lined for the color silver and the mat is shown lined for the color blue, to indicate a team with those colors.
It will be understood that in some instances, a card 18 , 30 may not be available. For example, the 1976 Raiders team was comprised of 19 players, and thus 19 or 20 cutouts 24 would be provided dependent on the existence of a stat or roster card for the index. A collector may not have all 19 cards. For this reason, the blanks 26 are provided. A blank 26 is inserted into an unused cutout 24 , to provide a more aesthetic appearance to the display, hiding the underlying backing 22 .
As described above, the display kit 10 of the present invention provides a number of advantages, some of which have been described above and others of which are inherent in the invention. Also modifications may be proposed to the kit 10 with out departing from the teachings herein. For example, the frame 12 may be of any functional shape and may be positioned in any desired orientation, such as horizontally displayed. Accordingly, the scope of the invention is only to be limited as necessitated by the accompanying claims.
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The structured trading card display kit provides a way of displaying trading cards in an organized manner, based on a particular index assigned to the kit. The index can be selected from a large possible group and the kit includes structure identifying the index as well as a display assembly.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority under 35 U.S.C. §119 of German Patent Application No. 198 13 640.4, filed on Mar. 27, 1998, the disclosure of which is expressly incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a calender and process, in particular for treatment of a paper web, the calendar having a roll stack of at least three rolls, with at least one double-soft nip formed between two rolls having elastic surfaces.
2. Description of Background Information
A calender is known, for example, from European Patent Application EP 0 748 895 A2. Calendars of this type play mainly two roles in paper manufacture. The first role of the calender is to agglomerate the paper web. The second role is to produce specific surface characteristics, for example, the highest gloss possible and the highest smoothness possible.
The calender known from EP 0 748 895 A2 has, in a roll stack of 6 to 12 rolls, alternatingly a “hard” and a “soft” roll. The hard rolls are heated and have a very smooth surface. They are, as a rule, designed as steel or cast-iron rolls. The smooth surface of a hard roll “imprints” itself on the surface of the paper web, and gives the paper web the desired smoothness and, together with the warmth produced by heating, the desired gloss. The “soft” rollers have an elastic surface and serve primarily to agglomerate the paper web. Since the surface of the soft rolls is elastic, the soft rolls avoid crushing of the fibers of the paper web to a certain extent.
As a rule, it is desirable to smooth both sides of the paper web. Accordingly, in the known calender, both sides of the paper web must be passed over a hard roll with a smooth surface. For this, a “change nip”, which is formed by two soft rolls, is required. This change nip has the sole role of altering the sequence of hard and soft rolls (e.g., switching the sides of the web to which the hard roll and soft rolls are applied). The actual effect on the paper web in the change nip is generally considered slight or negligible.
A similar situation also results with other material webs which must be processed in a similar manner, such as a paper or cardboard web.
SUMMARY OF THE INVENTION
In view of the shortcomings of the prior art, an object of the invention is to improve the capacity for action on the material web, i.e., to reduce the number of rolls required to achieve the desired effects and processing.
According to a first aspect of the present invention, a calender for treatment of a material web includes a roll stack of three or more rolls. The roll stack has two or more rolls with an elastic surface forming a double-soft nip. One or more heaters heats the double-soft nip formed by the two rolls with an elastic surface. The double-soft roll nip delimited by the two rolls with an elastic surface, i.e., the two “soft” rolls, thus assumes an additional function beyond that of a “change nip”. In this double-soft nip, because of the elevated temperature, energy can be introduced into the material web such that additional agglomeration is possible. The nip is therefore referred to as a “double-soft nip”. Because of the elevated temperature, the double-soft nip can be used for processing where a change nip would be wasted for the processing of the material web. In a more advantageous case, it is possible in such an embodiment to eliminate one of the remaining nips such that, under certain circumstances, the structural height of the calender may be reduced. This significantly reduces costs.
In one embodiment of the invention, the roll stack has at least three rolls each with an elastic surface, forming at least two double-soft nips. The heater or heaters then heat at least one of the three rolls forming each of two double-soft nips. For example, the calender has at least two double-soft nips and each double-soft nip can have at least one heatable roll. Thus, it is possible to utilize the advantageous effects of the double-soft nip in the calender two or more times, as long as at least one of the soft rolls which form the double-soft nip is heated.
Optionally, at least one of the rolls with an elastic surface forming the double-soft nip has a smooth surface having an average roughness not greater than 0.5 μm Ra under operating conditions. A smooth surface of this kind is possible even though the surface is elastic. In this manner, it is possible not only to agglomerate the material web in the double-soft nip, but also to smooth the web at least on the side which contacts the soft roll with the smooth surface. The results are further improved if both rolls forming the double-soft nip have the smooth surface. In this case, it is possible to agglomerate the material web in the double-soft nip(s) and to smooth it on both sides. Under certain circumstances, superfluous roll gaps or nips in the calender can thereby be eliminated. The two-sidedness of the material web can also be significantly reduced.
Further optionally, each of the rolls with an elastic surface includes a rigid or hard core and a surface layer formed from an elastic material. In this manner, construction is simplified. The hard core supports the elastic surface layer. Moreover, by an appropriate selection of the thickness of the surface layer, some parameters of the double-soft nip can be influenced.
Still further optionally, the elastic material has a predetermined good heat conductivity, e.g., no less than 10 W/m·K. The thermal conductivity of the elastic material can be improved by a number of measures, for example, through interlayering of high thermal conductivity material with elastic material, or the dispersion of high conductivity material such as metal fiber or metal powder throughout the elastic material in a composite form. It is also possible to use a material which, by itself, has a predetermined good thermal conductivity. In this case, a higher temperature produced, for example, inside the roll, can penetrate to the surface with low losses. Of course, it is also possible to heat the surface directly from the outside.
When a surface layer is used, the surface layer may have a thickness less than approximately 4 mm. More advantageously, the surface layer has a thickness from approximately 0.02 to 2 mm. An appropriately thin layer provides good heat transport from the inside of the roll to the outside with an appropriately low thermal resistance, such that it is possible to obtain the necessary temperatures on the surface of the surface layer very quickly and with low losses. Moreover, a thin surface layer has additional advantages. For example, the thin surface layer enables fibers of the material web, in particular in the case of a paper web, to be pressed locally or superficially against the elastic surface. On the other hand, a roll having a very thin surface layer has almost the operating characteristics of a “hard” roll, i.e., the thinlayer roll yields, in operation, a surface form of the roll which corresponds, at least approximately, to the surface form of a hard roll. This is true in particular when two soft rolls oppose each other in the double-soft nip, since similar conditions are present on both sides of the nip or roll gap. The deformation of the elastic surface layer remains very slight, in many cases even imperceptible, with a thin layer and a material web located in the double-soft nip. Accordingly, it is possible to obtain virtually the same compressive tension conditions as in a roll gap or nip made of one soft and one hard roll or even (almost) made from two hard rolls.
The surface layer may be formed from a plastic material. Plastics are available in a great variety such that it is possible to select the suitable plastic for the specifications. The thinner the layer, the lower the modulus of elasticity can be.
Alternatively, the surface layer is formed from a paint film coating. Thus, it is possible to use a “hard” roll for the roll with an elastic surface layer, i.e., a roll core made of steel or cast iron, which is then painted. Double-soft nips formed with such rolls produce excellent results, even when heating occurs only to a small extent.
In a modification of the invention, one of the rolls forming a double-soft nip includes a surface layer coating selected from metal, ceramic, or plastic. With this coating, the still greater smoothness may be produced. For example, it is possible to deposit a chrome layer, whose thickness is, for example, 120 μm, on the surface layer. Such a chrome layer is very smooth or can be made very smooth. A roll thus coated may be used in a double-soft nip without damaging the material web. Tests have shown that the use of such a coating along with a hard roll, despite the elastic surface layer under the coating, results in a black glazing and in a greasiness of the paper web. Of course, instead of a chrome layer, it is also possible to use other metals, ceramic materials, or plastics.
In one embodiment of the invention, every center roll in the roll stack (of at least three rolls) includes the elastic surface. The calender thus has only double-soft nips, with the exception of the feed nip and the exit nip. In particular, in conjunction with the smooth surfaces of the elastic rolls, it is possible to achieve satisfactory results with fewer rolls having double-soft nips than with conventional calendars. Of course, it is also possible that the upper roll and the lower roll of the calender be designed with an elastic surface. In this case, all the roll nips may actually be designed as double-soft nips.
Optionally, every center roll in the roll stack (of at least three rolls) is designed similarly, i.e., is of interchangeable structure and is interchangeable with others of the center rolls. In this manner, a distinction between hard and soft rolls is removed, which simplifies warehousing significantly. Of course, the center rolls may have certain differences, for example, with regard to diameter. They are, however, interchangeable with each other.
According to another aspect of the present invention, a calender for treatment of a material web includes a roll stack of at least three rolls, the roll stack having at least two rolls formed of a rigid core with an elastic surface. The two rolls face one another to form a double-soft nip therebetween, and a heater is formed within at least one of the two rolls. The heater heats the double-soft nip, and the paper web is agglomerated and smoothed in the double-soft nip. This arrangement has the advantages noted above with respect to the first aspect of the invention.
Optionally, each of the two rolls facing one another includes a rigid core, and a surface layer formed from an elastic material. The surface layer forms the elastic surface. This arrangement has the advantages noted above with respect to a rigid core and surface layer. In this case, the surface layer preferably has an average roughness not greater than approximately 0.5 μm Ra for the purpose of smoothing. Moreover, the surface layer preferably has a thickness less than approximately 4 mm (more ideally approximately 0.02 to 2 mm), which has the advantages noted above with respect to particular thicknesses and thin surface layers in general. The surface layer preferably has an elastic modulus of less than approximately 4,000 N/mm 2 . Further, the thickness of the surface layer is preferably selected to be less than a distance of a shearing stress maximum of the outer surface of the surface layer.
The surface layer may include a coating, of a material different from that of the elastic material, having a surface roughness of less than approximately 0.5 μm Ra. This arrangement has the advantages noted above with respect to the coating. In one variation, the coating includes a chrome layer, having a thickness of approximately 120 μm, deposited on the surface layer.
According to still another aspect of the invention, a process for using a calendar to treat a material web, includes introducing a material web into a roll stack having at least two rolls formed with an elastic surface layer over a rigid core, agglomerating the material web in an elastic double-soft nip between the at least two rolls of the roll stack, heating the material web in the elastic double-soft nip to introduce energy into the material web and promote the agglomerating, and smoothing the material web in the elastic double-soft nip between the at least two rolls of the roll stack. In this manner, it is possible to agglomerate the material web in the double-soft nip(s) and to smooth the material web on both sides, which may make possible the elimination of superfluous roll gaps or nips in the calender. Surface differences between the two sides of the material web can also be significantly reduced.
The elastic surface layer in the double-soft nip may have an elastic modulus of less than approximately 4,000 N/mm 2 , and a thickness of not greater than approximately 4 mm, for the agglomerating of the material web in the elastic double-soft nip. This arrangement has the advantages noted above with respect to particular thicknesses and thin surface layers in general.
The elastic surface layer in the double-soft nip may also have a surface roughness not greater than approximately 0.5 μm Ra for the smoothing of the material web in the elastic double-soft nip. This arrangement has the advantages noted above for smooth surfaces in the double-soft nip.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is further described in the detailed description which follows, in reference to drawing by way of non-limiting examples of an exemplary embodiment of the present invention, in which like reference numerals represent similar parts throughout the drawing, and wherein:
The single FIGURE, FIG. 1, depicts an embodiment of a calender according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The particulars shown herein are by way of example and for purposes of illustrative discussion of the embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show structural details of the present invention in more detail than is necessary for the fundamental understanding of the present invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the present invention may be embodied in practice.
As shown in FIG. 1, a calender 1 has a roll stack comprising a plurality of rolls, in this case, six rolls. The rolls of the roll stack are divided into center rolls and two outer rolls. For example, a six roll stack has four center rolls, while a three roll stack would have only one center roll. In FIG. 1, the two outer rolls are an upper roll 2 at the top position and a lower roll 3 at the bottom position. A paper web 18 runs through the calender 1 and is guided by deflecting rolls 29 .
The upper roll 2 and the lower roll 3 may be designed as deflection adjustment rolls, e.g., rolls in which the amount of deflection is adjustable. The adjustment is carried out by pressure shoes 4 , 5 , which can operate hydrostatically or by other means.
Four center rolls 6 - 9 are disposed, substantially in a line, between the upper roll 2 and the lower roll 3 . Preferably, all the center rolls 6 - 9 are designed similarly, with a substantially similar structure. E.g., the center rolls 6 - 9 are of interchangeable dimensions, and may include interchangeable mounting structures. However, even though substantially interchangeable, the center rolls 6 - 9 may vary in diameter or other properties. Thus, a structural distinction is not made between hard and soft rolls, a fact which simplifies warehousing quite significantly.
Roll gaps 19 , 20 , and 21 are formed between the center rolls 6 - 9 , and roll gaps 16 , 17 are formed between the center rolls 6 , 9 and the upper roll 2 and the lower roll 3 , respectively.
Each center roll 6 - 9 has a surface layer 10 surrounding a core 11 . The core 11 is rigid and/or hard, e.g., the core 11 is made of steel, cast iron or a comparable material. The surface layer 10 is preferably formed from a plastic that is resilient (elastic). Plastics are available in a great variety such that it is possible to select the suitable plastic for the specifications. The thinner the surface layer 10 , the lower the modulus of elasticity of the material or plastic can be. Alternatively, the surface layer may be a paint film. Thus, it is possible to use a “hard” roll for the center rolls 6 - 9 with an elastic surface layer 10 , i.e., a roll core made of steel or cast iron, which is then painted. Double-soft nips of the roll gaps 19 - 21 formed with such rolls produce excellent results even when heating (as described below) occurs only to a small extent.
The thickness of the surface layer 10 is less than approximately 4 mm. However, preferably, the thickness of the surface layer 10 falls within the range from approximately 0.02 mm through 2 mm. In this manner, the surface layer 10 may be applied as a paint coating. In FIG. 1, for purposes of illustration, the thickness of the surface layer 10 is exaggerated.
An appropriately thin surface layer 10 provides heat transport from the inside of a heater center roll 6 - 9 to the outside with an appropriately low resistance, such that it is possible to very quickly obtain the necessary temperatures on the surface of the surface layer 10 with low losses. Moreover, a thin surface layer 10 has additional advantages discussed below (e.g., local pressing of the material web 18 fibers into the thin surface layer, yet some behavior at the roll gap similar to that of a hard roll).
The use of a hard core 11 and a surface layer 10 made of an elastic material simplifies construction. The hard core 11 supports the elastic surface layer 10 . By means of the selection of the thickness of the surface layer 10 , some parameters of the double-soft nip (described below) can be influenced.
Heat channels 12 are distributed about the circumference of selected center rolls 6 - 9 . The heat channels 12 constitute a heater for heating the roll through which the channels 12 are formed. In FIG. 1, all of the center rolls 6 - 9 have such heat channels 12 . However, the invention does not require that all of the center rolls 6 - 9 be heated, nor that all of the center rolls have heat channels 12 . It is sufficient for each double-soft nip (described below) in the roll gaps 19 - 21 to be heated from at least one side. For example, every other roll may be heated as long as it is ensured that each roll gap 19 - 21 is heated. Of course, it is also possible to heat the surface of the center rolls 6 - 9 directly from the outside.
The material which forms the surface layer 10 preferably has a predetermined good heat conductivity, such that heat which is fed via the heating channels 12 into the core 11 can penetrate relatively quickly to the surface of the roll. The heat transfer is further enhanced by the thinness of the surface layer 10 . It is particularly advantageous if the elastic material of the surface layer 10 has a predetermined good heat conductivity. A good heat conductivity can be obtained by various measures, for example, through interlayering of high heat conductive material with elastic or resilient material. The material of the surface layer may be any suitable plastic, for example, thermosetting plastics, acrylic resin, or acrylic resin lacquer. To improve the heat conductivity of the surface layer, metallic fiber, metallic powder, or other high thermal conductivity additive material, may be dispersed throughout the plastic (matrix). However, it is also possible to use a material which has a predetermined good thermal conductivity by itself. When the surface layer 10 has good heat conductivity, a higher temperature produced inside the roll can penetrate to the surface with low losses. In one variation of this embodiment, the thermal conductivity of the surface layer 10 is greater than or equal to 10 W/m·K (i.e., no less than 10 W/m·K).
In a modification of the embodiment, as shown in FIG. 1, the second center roll 7 (from the top) further includes, outside of the surface layer 10 , a coating 13 made of metal, ceramic, or plastic. The coating 13 , since metal, ceramic, or plastic is used, may be made even smoother than the surface of the surface layer 10 , and in the preferred embodiment, has a lower average roughness Ra than an uncoated opposing surface layer 10 on an opposing roll (e.g., as noted below, therefore less than 0.5 μm Ra, or even less than 0.1 μm Ra). When a roll having the coating 13 is employed, only one such roll should be present per roll nip. For example, a double-soft nip may be formed from a roll having only a surface layer 10 and another roll having a surface layer 10 coated with the coating 13 . With this coating 13 , the capability of producing still greater smoothness is obtained. For example, it is possible to deposit a chrome layer as the coating 13 , whose thickness is, for example, approximately 120 μm, on the surface layer 10 . Such a chrome layer as the coating 13 is very smooth, or can be made very smooth. A center roll 6 - 9 thus coated may be used in a double-soft nip of a roll gap 19 - 21 without damaging the material web 18 . Tests have shown that the use of the chrome layer as the coating 13 along with a hard roll, despite the elastic surface layer 10 under the coating 13 , results in a black glazing and in a greasiness of the paper web. Of course, as noted above, instead of a chrome layer, it is also possible to use other metals, ceramic materials, or plastics.
In the embodiment shown in FIG. 1, the upper roll 2 and the lower roll 3 are designed with “hard” roll jackets 14 , 15 . Consequently, between the top center roll 6 and the upper roll 14 , and between the bottom center roll 9 and the lower roll 15 , “soft” roll gaps or nips 16 , 17 are formed in which a hard roll faces a soft roll. The paper web 18 , which runs through the calender 1 and is guided by deflecting rolls 29 , lies, consequently, once with its top on a “hard” roll (i.e., the upper roll 14 ) and once with its bottom on a “hard” roll (i.e., the lower roll 15 ).
The remaining three roll gaps 19 - 21 are, in contrast, always delimited by two rolls 6 - 9 , each of which has an elastic surface. Consequently, the roll gaps at the interfaces of the rolls 6 - 9 form double-soft nips. As previously noted, each double-soft nip of the roll gaps 19 - 21 is heated by at least one set of heating channels 12 in a facing roll 6 - 9 . Preferably, the calender 1 has at least two double-soft nips and each double-soft nip has at least one heatable roll. Thus, it is possible to utilize the advantageous effects of the double-soft nips of the roll gaps 19 - 21 in the calender 1 a plurality of times, as long as at least one of the soft rolls which form the double-soft nip is heated.
Preferably, at least all of the center rolls 6 - 9 have an elastic surface layer 10 . The calender 1 thus has only double-soft nips (at the roll gaps 19 - 21 ), with the exception of the feed nip at the roll gap 16 and the exit nip at the roll gap 17 . In particular, in conjunction with the smooth surfaces of the elastic rolls 6 - 9 , it is possible to achieve sufficient processing with a few double-soft nips, and thereby to reduce the number of rolls. Of course, it is also possible that the upper roll 2 and the lower roll 3 of the calender 1 be designed with an elastic surface layer 10 . In this case, all the roll nips at the roll gaps 16 - 17 and 19 - 21 may actually be designed as double-soft nips.
When at least one of the rolls 6 - 9 forming the double-soft nip of a roll gap 19 - 21 is heatable, the double-soft nips thus assume an additional function. In the double-soft nips of the roll gaps 19 - 21 , because of the elevated temperature, energy can be introduced into the material web 18 such that at least additional agglomeration is possible. Because of this additional function, the double-soft nips of the roll gaps 19 - 21 are not simple change nips. That is, because of the elevated temperature, the double-soft nips of the roll gaps 19 - 21 can be used for processing.
The center rolls 6 - 9 all have a very smooth surface, i.e., under operating conditions with an average roughness not greater than approximately 0.5 μm Ra. The average roughness is even more advantageously kept at approximately 0.1 μm Ra or less. Such a smooth surface can be realized even in conjunction with an elastic surface, for example, in the manner described in German Patent No. DE 195 06 301 A1. The disclosure of German Patent No. DE 195 06 301 A1 is expressly incorporated by reference herein in its entirety.
Thus, it is possible not only to agglomerate the material web 18 in the double-soft nip of the roll gaps 19 - 21 , but also to smooth the material web 18 at least on the side which contacts the soft roll with the smooth surface. Processing is even more efficient if both rolls forming the double-soft nip of the roll gaps 19 - 21 have the smooth surface layer 10 and/or coating 13 as described. In this case, it is possible to agglomerate the material web 18 in the double-soft nip(s) of the roll gaps 19 - 21 and to smooth the material web 18 on both sides, which may make possible the elimination of superfluous roll gaps or nips in the calender 1 . Surface differences between the two sides of the material web 18 can also be significantly reduced.
The center rolls 6 - 9 have almost the operating behavior of a hard roll because of the low thickness of the surface layer 10 . Moreover, because of the elastic surface formed by the surface layer 10 , fibers of the paper web 18 are locally or superficially pressed into the surface of the center rolls 6 - 9 . Other than this local pressing, the rolls 6 - 9 have virtually the same behavior as their core 11 with respect to elasticity.
That is, although as previously discussed the thin surface layer 10 enables fibers of the material web 18 to be pressed locally or superficially into the elastic surface, at the same time, the center rolls 6 - 9 with a hard core 11 and a very thin surface layer 10 have almost the characteristic of a “hard” roll. For example, the center rolls 6 - 9 with the hard core 1 1 and thin surface layer 10 yield, in operation, a surface form of the rolls 6 - 9 which corresponds at least approximately to the surface form of a hard roll. This is true in particular when two soft rolls 6 - 9 oppose each other in the double-soft nip of the roll gaps 19 - 21 , since similar conditions are present on both sides of the double-soft nip or roll gap 19 - 21 . The deformation of the elastic surface layer 10 remains very slight, in many cases even imperceptible, with a thin layer 10 and a material web 18 located in the double-soft nip of the roll gaps 19 - 21 such that it is possible to obtain virtually the same compressive tension conditions as in a roll gap or nip made of one soft and one hard roll or even approaching that of two hard rolls.
The surface layer 10 is preferably made of a material which has an elastic modulus of approximately 4,000 N/mm 2 or less. The thickness of the surface layer 10 is also preferably selected to be less than the distance of the shearing stress maximum of the outer surface of the surface layer 10 . The center rolls 6 - 9 may be structured as described in the subsequently published German patent application 197 10 573. The disclosure of subsequently published German patent application 197 10 573 is expressly incorporated by reference herein in its entirety.
Accordingly, the embodiment of a calender 1 according to the invention obtains excellent results with regard to glazing even with few roll gaps. The paper web 18 is not only agglomerated, but simultaneously is given excellent smoothness and excellent gloss because of the smooth surfaces of the “soft” rolls in the double-soft nips of the roll gaps 19 - 21 . It is, therefore, possible to eliminate one or a more nips or roll gaps from the conventional calender, and the structural height of the calender may also be reduced. Accordingly, a significant cost savings is achieved through the use of the double-soft nips.
While the present invention has been described with reference to an exemplary embodiment, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent and/or insubstantially different structures, such as are within the scope of the appended claims.
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Calender for the treatment of a paper web including a roll stack of at least three rolls and with least one double-soft nip. The double-soft nip(s) are formed by two rolls, each with an elastic surface layer. At least one of the rolls forming the double-soft nip is heated. In a process using the calendar to treat a material web, the web is introduced into a roll stack having at least two rolls formed with an elastic surface layer over a rigid core, agglomerated in an elastic double-soft nip between the two rolls, heated to introduce energy into the material web and promote agglomerating, and smoothed in the elastic double-soft nip.
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FIELD OF THE INVENTION
[0001] The present invention relates to ceramic inkjet inks and to a method for decorating green or fired ceramic bodies by the use of inkjet printing.
[0002] The ceramic inkjet inks of the invention comprises ceramic inorganic pigments, having average particle size between 0.1 and 0.8 μm, dispersed in an organic medium and a dispersing agent which is the reaction product of a polyethyleneimine and a 12-hydroxystearic acid and ε-caprolactone co-polyester.
BACKGROUND OF THE ART
[0003] Most traditional ceramic manufactured products, such as wall tiles and floor tiles, are made of a ceramic body that confers form and mechanical properties to the object; the ceramic body generally has some porosity and poor aesthetic qualities.
[0004] Said ceramic body, which is defined “green” or, alternatively, “fired”, if previously fired, is then usually coated with a ceramic layer, called ceramic glaze; the ceramic glaze is completely sintered by firing, in such a way to gain suitable superficial aesthetic qualities and, in the meantime, to become a fluid-proof barrier; as a matter of fact, after firing, the ceramic glaze has usually no porosity and it is generally resistant to abrasion and to the attack of chemical agents such as acids, bases, dyes.
[0005] The aesthetic finishing of the ceramic material can be completed by a decoration phase, that is by the application of sinterable and variously coloured ceramic materials which are applied according to a preset drawing (décor).
[0006] The décor can be applied either on green or fired ceramic body, on which the glaze was previously set, or, in the so called third firing decorations, after the firing, on the sintered glaze.
[0007] Different techniques are used to transfer images to the ceramic substrate: i.e. screen printing and photogravure (commonly referred to as rotocolor). These technologies require flat substrate or with minimum roughness and they are suitable for mass production, but have very limited flexibility of new design set up and changeover among designs.
[0008] Another technique of printing decoration on ceramics is digital printing by inkjet technique.
[0009] Digital printing and decoration by inkjet technique is widely used in multiple sectors, such as graphic arts, textile industry, industrial marking and it is well known, both referring to the printing equipments and also to the inks used.
[0010] Peculiarly in ceramic applications, the thermal treatment, which is required once the substrate has been printed, makes the conventional inks, that are used in the other applications and are mainly based on organic pigments, unsuitable for use.
[0011] Two kind of inks for inkjet printing of ceramics are known: inks constituted by solutions of metallic cations and inks based on dispersions of inorganic pigments.
[0012] As far as inks based on dispersions of inorganic pigments are concerned, it is mandatory that the inorganic pigments are well dispersed into the liquid medium and possess nano-scale dimensions, for the ceramic inkjet ink flows at high speed through the small nozzles of the print head (30-100 μm in diameter).
[0013] Nano-scale dispersions of the inorganic pigments are usually obtained by milling with microspheres the pre-dispersed pigments in the medium, in the presence of milling aids.
[0014] Examples of ceramic inkjet inks based on dispersions of inorganic pigments in polar organic mediums are described in EP 2159269, WO 2006/126189, EP 1840178; the inks are generically said to contain antisettling and/or dispersing agents.
[0015] Nonetheless, there is still the industrial need for improved ceramic inkjet inks based on inorganic ceramic pigments having low viscosity, particle size below 0.8 μm, long shelf life and suitable to be printed on ceramic surfaces and passed through a high temperature kiln to form a permanently sintered glazed print.
[0016] It has now been found that the reaction product between a polyethyleneimine and a 12-hydroxystearic acid and ε-caprolactone co-polyester can conveniently be used in the preparation of inkjet inks for ceramic inkjet printing machines. Surprisingly, the reaction product between a polyethyleneimine and a 12-hydroxystearic acid and ε-caprolactone co-polyester, is perfectly suitable, in the milling phase, to fluidize the pre-dispersed inorganic ceramic pigments, allowing their rapid milling and subsequently preventing agglomeration and sedimentation of the nano-scale inorganic ceramic pigments in the final inks. The reaction products between a polyethyleneimine and a 12-hydroxystearic acid polyester are known products that belongs to a wide class of dispersing agents obtained by amidation and/or salification of polyimines and carboxyl terminated polyesters. They have been described in many patents; by way of example we cite: U.S. Pat. No. 4,224,212, U.S. Pat. No. 4,861,380, U.S. Pat. No. 5,700,395, U.S. Pat. No. 6,197,877 and JP 63-197529.
[0017] JP 63-197529, in particular, describes dispersing agents obtained by reaction between a polyethylenimine and a block polyester. The block polyester derives from a reaction of a monocarboxylic acid with ε-caprolactone followed by a reaction with 12-hydroxystearic acid. Though according to the general description of JP 63-197529, the dispersing agent can contain a high number of 12-hydroxystearic acid residues (up to 10 moles of 12-hydroxystearic acid residues per mole of ε-caprolactone), the examples show only co-polyesters prepared by a mixture of acids that contains between 10% and 26% (w/w) of 12-hydroxystearic acid.
[0018] Such wide class of dispersing agents reported above, is generally suitable for use as dispersing agents for various solids in organic liquids.
[0019] However, none of the above mentioned documents hints that the reaction product between a polyethylenimine and a 12-hydroxystearic acid and ε-caprolactone co-polyester, can be used as dispersing agent in applications where the solid is an inorganic vitrifiable ceramic pigment with nano scale dimensions, as required for the preparation and stabilization of ceramic inkjet inks.
[0020] The patent application WO 2012/076438 reports a dispersing agent suitable for grinding and stabilizing ceramic inkjet inks and it is obtained by reaction between a polyethylenimine and a polyester derived from ricinoleic acid. In this patent application it is pointed out that a dispersing agent obtained from polyethylenimine and 12-hydroxystearic acid homo-polyester is by far less effective in the ceramic pigments milling at the nanoscale range and dispersing activity, than the dispersing agent derived from polyethylenimine and ricinoleic acid polyester.
[0021] Now we found that the reaction product between a polyethylenimine and a 12-hydroxystearic acid and ε-caprolactone co-polyester, in the peculiar application, gives better performance than those of analogous dispersing agents derived from ricinoleic acid instead that from 12-hydroxystearic acid, even when the weight percentage in 12-hydroxystearic acid used in the co-polymer synthesis is high.
DRAWINGS
[0022] The reological curves (flow curves at variable shear rates) of a ceramic inkjet ink containing as dispersing agent the reaction product between a polyethylenimine and a 12-hydroxystearic acids-caprolactone co-polyester (Ink A) and of a comparative inkjet ink (Ink C) at 35° C. and 40° C. are reported in FIG. 1
SUMMARY OF THE INVENTION
[0023] In one aspect, the invention is a composition for ceramic inkjet inks comprising a ceramic inorganic pigment, an organic medium and a dispersing agent which is the reaction product between a polyethyleneimine and a 12-hydroxystearic acid and ε-caprolactone co-polyester, wherein said co-polyester contains from 10 to 90% (w/w) of residues derived from 12-hydroxystearic acid, from 10 to 90% (w/w) of residues derived from ε-caprolactone and the total sum to 100% is constituted by no more than 30% (w/w) of residues coming from monocarboxylic acids used as starters of the co-polyester and/or from other hydroxycarboxylic acids or C 6 -C 18 lactones and wherein said ceramic inorganic pigment has average particle size between 0.1 and 0.8 μm.
[0024] In another aspect, the invention is a method for decorating green or fired ceramic bodies by inkjet printing that comprises the following steps:
i. a ceramic inkjet ink comprising a ceramic inorganic pigment having average particle size between 0.1 and 0.8 μm is prepared by milling an inorganic ceramic pigment having initial average particle size between 1.0 and 10.0 μm in an organic medium, in the presence of a dispersing agent which is the reaction product between a polyethyleneimine and a 12-hydroxystearic acid and ε-caprolactone co-polyester, wherein said co-polyester contains from 10 to 90% (w/w) of residues derived from 12-hydroxystearic acid, from 10 to 90% (w/w) of residues derived from ε-caprolactone and the total sum to 100% is constituted by no more than 30% (w/w) of residues coming from monocarboxylic acids used as starters of the co-polyester and/or from other hydroxycarboxylic acids or C 6 -C 18 lactones; ii. a glaze is spread on the surface of a green or fired ceramic body; iii. the decoration is made by means of inkjet printing, by using one or more ceramic inkjet inks according to point i.; iv. the obtained substrate is fired at temperature comprised between 900 and 1250° C. for 15-240 minutes.
DETAILED DESCRIPTION OF THE INVENTION
[0029] The inorganic ceramic pigment of the inkjet ink of the present invention shall exhibit an average particle size (d 50 ) less than 0.8 μm, preferably from 0.1 to 0.5 μm and most preferably from 0.1 to 0.3 μm, as measured by laser diffraction particle size analysis (ISO 13320-2009).
[0030] The average particle size, i.e. the average equivalent diameter, is the diameter where 50 percent by weight of the particles have a larger equivalent diameter, and the other 50 percent by weight have a smaller equivalent diameter.
[0031] Any of the recognized classes of pigments used in ceramic decoration (ceramic pigments) may be used such as, for example, zirconates and silicates of Cr, Sn, Ni, Pr, Fe, Co and oxides thereof, and preferably those ceramic pigments selected from ZrPr, ZrPrSi, ZrFeSi, TiCrSb, CoAlZn, ZrVaSi, FeCrCoNi, CrCaSnSi, CoSi, and FeCrZn.
[0032] The organic medium present in the ceramic inkjet ink is preferably a polar organic medium or a substantially non-polar aliphatic or aromatic hydrocarbon or a halogenated hydrocarbon, including mixtures thereof.
[0033] For example, suitable polar organic mediums are selected among one of glycol ethers or glycol ether esters exhibiting a flash point in excess of 75° C., such as polypropylene glycol, tripropylene glycol monomethyl ether (Dowanol TPM), tripropylene glycol butyl ether (TPB), butyl glycol ether acetate.
[0034] Examples of suitable non-polar mediums are long chain aliphatic solvents such as isoparaffins, commercially available as ISOPAR products (ExxonMobil Chemical) and the corresponding products from BP and Total, dearomatised aliphatic hydrocarbons, commercially available as EXXSOL (ExxonMobil Chemical) and the corresponding products from Total, 2-isopropylnaphthalene and 2,6-diisopropylnaphthalene.
[0035] The preferred organic mediums are tripropylene glycol monomethyl ether and tripropylene glycol butyl ether.
[0036] The dispersing agent, which is the reaction product between a polyethyleneimine and a 12-hydroxystearic acid and ε-caprolactone co-polyester, is obtained by amidation and/or salification of a linear or branched polyethyleneimine with a 12-hydroxystearic acid and ε-caprolactone co-polyester.
[0037] Branched polyethyleneimines of differing molecular weight are commercially available, by way of example from BASF (under the trade name Lupasol®) and Nippon Shokubai (under the trade name Epomin®).
[0038] Linear polyethyleneimines can be prepared by hydrolysis of poly (N-acyl) alkyleneimines as described by Takeo Saegusa et al. in Macromolecules, 1972, Vol. 5, page 4470.
[0039] The polyethyleneimines are preferably branched and have an average molecular weight from 100 to 600,000, more preferably from 1,000 to 200,000, even more preferably from 1,000 to 100,000 and especially from 1,000 to 70,000.
[0040] The evaluation of the average molecular weight of polyethyleneimine is well known to the person skilled in the field and it is carried out by size exclusion chromatography, using a light scattering detector, such as an Agilent 1100 differential refractometer equipped with an Agilent 110 VWD UV photometer and a Wyatt Dawn EOS light scattering detector.
[0041] The 12-hydroxystearic acid and ε-caprolactone co-polyester may be prepared by polymerization of 12-hydroxystearic acid and ε-caprolactone at temperature between 150 and 180° C., as described for example in U.S. Pat. No. 4,224,212; in the preparation of the co-polyester it is preferred to include an esterification catalyst such as a tin salt of an organic acid, for example tin bis 2-ethylhexanoate, dibutyl tin dilaurate, a tetra-alkyl titanate, for example tetrabutyltitanate, a zinc salt of an organic acid, for example zinc acetate, a zirconium salt of an aliphatic alcohol, for example zirconium isopropoxide, toluene sulphonic acid or a strong organic acid such as a halo acetic acid, for example trifluoro acetic acid.
[0042] The weight percent of residues of 12-hydroxystearic acid in the co-polyester is within 10 and 90%, preferably within 30 and 90%, more preferably within 50 and 90%. High percentages of 12-hydroxystearic acid are preferred because surprisingly they do not impair the activity of the dispersing agent and they are economically attractive. The weight percent of residues of ε-caprolactone in the co-polyester is complementary to that of the residues of 12-hydroxystearic acid, unless when the co-polyester includes residues derived from other hydroxycarboxylic acids or C 6 -C 18 lactones, such as 12-hydroxydodecanoic acid, 5-hydroxydodecanoic acid, 5-hydroxydecanoic acid, 4-hydroxydecanoic acid and ricinoleic acid, and/or residues derived from unsubstituted monocarboxylic organic acids used as initiators in co-polyester synthesis. When these residues are present, their weight percent is less than 30%, preferably less than 10%; more preferably the 12-hydroxystearic acid ε-caprolactone co-polyester does not contain any other hydroxycarboxylic acid derivatives.
[0043] In the preferred embodiment the 12-hydroxystearic acid and ε-caprolactone co-polyester does not contain any residue derived from other hydroxyacids or lactones and it is a random polymer.
[0044] The 12-hydroxystearic acid and ε-caprolactone co-polyester shall be carboxyl terminated from one side, and may be eventually started with an organic monocarboxylic acid, different from the 12-hydroxystearic acid, and it can be aromatic, heterocyclic, alicyclic or preferably aliphatic and it is optionally substituted by halogen, C 1-4 -alkoxy groups. Preferably, in this case, the organic monocarboxylic acid is unsubstituted. When the organic monocarboxylic acid is aliphatic, it may be linear or branched, saturated or unsaturated, but it is preferably saturated. The total number of carbon atoms in the starting organic monocarboxylic acid can be as high as 50, but it is preferred that it contains not less than 8, more preferably not less than 12 and especially not less than 14 carbon atoms. It is also preferred that the organic monocarboxylic acid contains not more than 30, more preferably not more than 25 and especially not more than 20 carbon atoms.
[0045] Particularly useful effects have been obtained with co-polyesters having number-average molecular weight between 800 and 2,000 and polyethyleneimine having a number-average molecular weight of from 1,000 to 70,000.
[0046] The mean molecular weight of the 12-hydroxystearic acid and ε-caprolactone co-polyester is determined from the acid value (or “neutralization number” or “acid number” or “acidity”), which is the mass of potassium hydroxide (KOH) in milligrams that is required to neutralize one gram of co-polyester, as it is well known in the field.
[0047] The dispersing agent of the invention is obtained by reacting the polyethyleneimine and the above described 12-hydroxystearic acid and ε-caprolactone co-polyester at temperature between 50 and 250° C., preferably in an inert atmosphere. Preferably, the temperature is not less than 80° C. and especially not less than 100° C. and not greater than 150° C.
[0048] The weight ratio of 12-hydroxystearic acid and ε-caprolactone co-polyester to polyethyleneimine is preferably from 1 to 100.
[0049] At least two moles of co-polyester shall be attached to each mole of polyethyleneimine.
[0050] The ceramic inkjet ink typically contains from 5 to 60% by weight of the ceramic pigment, the precise quantity depending on the nature of the pigment and on the relative densities of the pigment and the organic medium. Preferably the dispersion contains from 15 to 45% by weight of the pigment.
[0051] The content of liquid organic medium is from 30 to 80% by weight based on the total weight of the ink, preferably from 45 to 80% by weight.
[0052] The content of the dispersing agent in the ink is between 2 and 15% by weight based on the total weight of the ink, preferably from 4 to 10% by weight.
[0053] The ceramic inkjet ink of the invention is prepared by milling a commercial ceramic inorganic pigment having average particle size between 1.0 and 10.0 μm, in the presence of the liquid organic medium and the reaction product between a polyethyleneimine and 12-hydroxystearic acid and ε-caprolactone co-polyester.
[0054] The inorganic ceramic pigment, the liquid organic medium and the reaction product of a polyethyleneimine and a 12-hydroxystearic acid and ε-caprolactone co-polyester may be mixed in any order, the mixture then being subjected to a mechanical treatment to reduce the particles of the pigment to an appropriate size by milling with milling beads having diameters from 0.1 to 0.5 mm.
[0055] When the pigment is milled, the temperature is preferably not greater than 45° C.
[0056] The viscosity of the ceramic inkjet ink is between 5 and 50 mPa·s, and preferably between 8 and 30 mPa·s.
[0057] The invention is further illustrated by the following examples wherein all references are to parts by weight unless expressed to the contrary.
EXAMPLES
Preparation of Dispersing Agent A
[0058] A mixture of 473.1 parts of 12-hydroxystearic acid, 176.9 parts of ε-caprolactone and 1.3 parts of tin bis 2-ethylhexanoate was stirred, under nitrogen, and heated at 180° C. for 10 hours, removing the esterification water. The product was an oil liquid with an acid value of 49 mg KOH/g (Polyester 1).
[0059] 25.4 parts of Lupasol WF (polyethylenimine from BASF having MW 25,000) and 324.6 parts of Polyester 1 were strirred, under nitrogen, and heated to 120° C. for 2 hours.
[0060] The dispersing agent (Dispers. A) was obtained as a viscous liquid.
Preparation of Dispersing Agent C (Comparative)
[0061] A mixture of 470.1 parts of ricinoleic acid, 179.8 parts of ε-caprolactone and 1.3 parts of tin bis 2-ethylhexanoate was stirred, under nitrogen, and heated at 180° C. for 10 hours, removing the esterification water. The product was an oil liquid with an acid value of 51 mg KOH/g (Polyester 2).
[0062] 25.4 parts of Lupasol WF (polyethyleneimine from BASF having MW 25,000) and 324.6 parts of Polyester 2 were strirred, under nitrogen, and heated to 120° C. for two hours. The dispersing agent (Dispers. C) was obtained as viscous liquid.
Solubility of Dispersing Agents
[0063] The solubility of dispersing agents was evaluated at 20° C. at a concentration of 5% by weight in tripropylen glycol butyl ether (TPB) and tripropylen glycol methyl ether (TMP) under stirring with a magnetic stirrer for 5 min. and after storage at 20° C. for 24 hours and for 7 days.
[0064] Both Dispers. A and Dispers. C are freely soluble in both solvents.
Preparation of the Ceramic Inkjet Inks
[0065] Two ceramic inkjet inks (Ink A and Ink C) were prepared, by using in each a different dispersant (Ink A with Dispers. A and Ink C with Dispers. C).
[0066] 7.8 g of dispersing agent were stirred and dissolved in 89.7 g of Dowanol TPM in 5 minutes.
[0067] 52.5 g of blue pigment (cobalt silicoaluminate) were added and mixed for 5 minutes.
[0068] The blue pigment had d 50 =2.0 μm, measured by particle Size Analysis (Mastersizer 2000, Malvern Instruments).
[0069] 200 g of grinding media (YTZ® Grinding Media 0.3 mm, made of Yttrium Stabilized Zirconia Grinding Beads, produced by Nikkato Corporation) and 60 g of the mixture prepared as described above were charged into a 125 ml grinding jar made in zirconium oxide and milled in a planetary ball mill (PM 200 produced by Retsch).
[0070] The dispersing agent performances were evaluated by measuring the particle size distribution of the pigment in the inkjet ink after milling, the rheological ink curves and the stability on storage of the inkjet inks at 60° C.
Particle Size Distribution of the Pigment
[0071] The particle sizes of the pigment (d 50 ), as measured by a Mastersizer 2000 Malvern Instrument, after 3 hours milling, are reported in Table 1
[0000]
TABLE 1
Milling time and particle size
milling time
d 50
InkJet ink
(hours)
(μm)
Ink A
3
245
Ink C *
3
267
* comparative
Rheological Curves
[0072] The rheological curves (flux curve at variable shear rate) at 35° C. and 40° C. are reported in FIG. 1 for Ink A and Ink C.
[0073] Ink A has lower viscosity than that of Ink C at all shear rates.
Stability
[0074] The stability of the inkjet inks was evaluated by visual examination of their omogeneity (or phase separation of liquid phases and/or sedimentation) after the storage at 60° C. for 12 days.
[0075] Both Ink A and Ink C are omogeneous after 12 days at 60° C.
[0076] On the stored inks the rheological curves at 35° and 45° C. were recorded: for both inks no significant variation with time 0 were observed.
[0077] From the comparison of the above results we can say that Dispers. A is a better milling aid than Dispers. C (lower particle size with same milling time) and it is better in reducing the viscosity of the ink. It has good solubility characteristics as well as good stabilizing capacity.
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Method for decorating green or fired ceramic bodies by inkjet printing comprising the use of a ceramic inkjet ink which is prepared by milling a ceramic inorganic pigment in an organic medium in the presence of a dispersing agent which is the reaction product of a polyethyleneimine and a 12-hydroxystearic acid and ε-caprolactone co-polyester, until the average particle size of the pigment is between 0.1 and 0.8 μm.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a national stage application of International Application No. PCT/EP2009/064020, filed on Oct. 23, 2009, which claims the benefit of German Patent Application No. DE 10 2008 053 145.6, filed on Oct. 24, 2008, the entire contents of both applications are incorporated herein by reference in their entireties.
BACKGROUND OF THE INVENTION
Field of the Invention
Embodiments of the present invention relate to a flow directing device for a cooking appliance with a fan mechanism, which comprises at least one fan wheel in an interior of the cooking appliance for circulating atmosphere, comprising at least one first flow directing member for subdividing the interior into a pressure chamber with the fan wheel and a cooking chamber, wherein the first flow directing member leaves free at least one suction port for sucking atmosphere from the cooking chamber into the pressure chamber in the area of the fan wheel and at least one blow-off port for blowing atmosphere from the pressure chamber into the cooking chamber when the fan wheel is in operation, at least one second flow directing member, which is mounted onto the fan mechanism or molded with the fan mechanism in the area of the suction port of the first flow directing member in order to improve the flow from the cooking chamber into the pressure chamber by forcing an axial main flow in the suction zone of the fan mechanism, and a cooking appliance with such a flow directing device.
Description of the Related Art
In the prior art, numerous measures for optimising a flow in the interior of a cooking appliance are known. Usually, a first flow directing member is used in the form of an air directing plate between a cooking chamber and a fan chamber or pressure chamber, which comprises a central suction port and leaves open blow-off ports facing the walls of the interior, so that a fan wheel arranged in the pressure chamber can suck atmosphere from the cooking chamber through the suction port and blow it out via the blow-off ports.
DE 203 14 818 U1, for example, deals with the targeted blowing of atmosphere from the pressure chamber into the cooking chamber via specially arranged blow-off ports in the first flow directing member. DE 10 2007 023 767, which is not pre-published, also deals with the blow-off ports of a first flow directing member, wherein movable elements should be arranged in blow-off ports, which move depending on the pressure progression in the cooking chamber. Another approach can be found, for example, in DE 203 09 268 U1 by using second flow directing members in the fan chamber in which a breaking up of the eddies should be forced while passing through a blow-off port between the pressure chamber and the cooking chamber, so that eddies spread out in the cooking chamber. Second flow directing members for forcing a homogeneous flow in the cooking chamber are also described in DE 203 12 031 U1.
A further flow directing device can be found, for example, in DE 10 2004 004 393 B4, in which a first flow directing member is in the form of a single piece with a second flow directing member. More precisely, the edge of the first flow directing member is turned in the form of an air directing plate in the area of its suction port to form a flow directing nozzle. This nozzle is a suction nozzle and is designed to improve the suction of atmosphere from a cooking chamber into a fan chamber of a cooking appliance. However, the disadvantage here is that a gap must be present at all times between a rotating fan wheel in the pressure chamber on the one hand, and the suction nozzle on the air directing plate on the other, in order to avoid damage. With cooking appliances in industrial kitchens in particular, this gap is large enough, due to tolerances, to enable atmosphere to flow from the pressure chamber directly into the suction area of the fan wheel, i.e., it is not directed via a blow-off port into the cooking chamber and via the suction port of the air directing plate into the suction area of the fan wheel, so that a short-circuit occurs with the atmosphere, which flows in from the cooking chamber through the suction port of the air directing plate. For this reason, this flow, which penetrates through the gap, is also known as a short-circuit flow, and occurs at a very sensitive point in the suction area of the fan wheel, i.e., in the deflection area of a main flow from the cooking chamber into the pressure chamber, more precisely, where a deflection occurs from a radial direction into an axial direction of the main flow. Thus, the short-circuit flow runs transverse to the main flow in the suction area of the fan wheel, so that it narrows the main flow and can itself cause a displacement and swirling of the main flow, which leads to an overall reduction in the effectiveness of the circulation of cooking chamber atmosphere by the fan wheel.
Generic flow directing devices for cooking appliances are described in EP 1 767 869 A2 and DT 25 19 604, wherein in both cases, a first flow directing member spreads out at least up to the suction port of a fan wheel, and in the case of DT 25 19 604, even extends into the suction port, while the second flow directing member is provided in the form of an outer contour of the fan wheel.
SUMMARY OF THE INVENTION
The object of the embodiments of the present invention is therefore to further develop the generic flow directing device in such a manner that it overcomes the disadvantages of the prior art. In particular, the effectiveness of a circulation within the interior of a cooking appliance should be improved.
This object is attained according to the embodiments of the present invention by means of the fact that each second flow directing member fulfils or performs a nozzle function, extends from the fan mechanism into the cooking chamber, and protrudes over or overlaps the edge of the suction port of the first flow directing member, while the first flow directing member spreads out into each second flow directing member.
Here, it is preferred that in cases when the fan mechanism comprises at least one radial fan, which includes a plurality of blades that are attached to a holding device, in particular, in the form of a support ring, and are arranged concentrically with a drive shaft, the second flow directing member is attached or molded with the shaft, the holding device, in particular, the support ring, and/or at least one blade.
According to embodiments of the present invention, it can here in turn be provided that the second flow directing member is in the form of a ring, in particular when attaching it to the holding device or molding it to the holding device.
Embodiments of the present invention are also directed to second flow directing members that extend into the pressure chamber up to the pressure area of the fan wheel.
Furthermore, it can be provided that each second flow directing member comprises a profile form of such a type that a flow from the cooking chamber into the pressure chamber only separates from the axial main flow as far as possible inside the pressure chamber, wherein preferably, an essentially hook-shaped profile or, in particular an asymmetric, U-shaped profile with an extended free end of the second flow directing member, is molded in the pressure chamber.
Additionally, embodiments of the present invention are directed to first flow directing members that are attached or are attachable to a wall of the interior.
Further embodiments of the present invention can also include by a third flow directing member in the pressure chamber, which, in particular, limits a blow-off area of the radial fan that extends conically outwards from the fan wheel of the radial fan.
Additionally, the third flow directing member can be attached to the first flow directing member, or can be moulded together with it.
Alternatively, the third flow directing member can be an extension of the second flow directing member, in particular at the free end of the second flow directing member in the pressure chamber.
According to the embodiments of the present invention, it is also recommended that the first flow directing member, the second flow directing member and/or the third flow directing member is or are in each case molded from at least one punched bending part and/or plate and/or is or are detachably affixed and/or is or are at least partially movable, or movable in sections.
Furthermore, the end of the second flow directing device can extend into the pressure chamber into a recess in the first and/or third flow directing device.
Particularly advantageous embodiments of the present invention are characterized by a plurality of fourth flow directing members, in particular, one fourth flow directing member for each blade, wherein, preferably, each fourth flow directing member is designed as a blade and/or as a blade extension, and most preferably extending through the support ring.
The embodiments of the present invention also provide a cooking appliance with a heating mechanism for heating atmosphere in a cooking chamber, a fan mechanism for circulating atmosphere at least in the cooking chamber and a flow directing device according to the embodiments of the present invention.
Additionally, the first flow directing member, the second flow directing member and/or the third flow directing member can be movable at least partially or in sections, preferably via a control or regulating mechanism, which interacts with the heating mechanism, the fan mechanism, a steam feed mechanism, a steam removal mechanism, a cooling mechanism, an energy saving mechanism, a microwave source, a gas feed mechanism, a gas removal mechanism, a sensing mechanism and/or a cleaning mechanism.
Finally, a shield, which can be of a grid or screen type, at least of the second flow directing member in the cooking chamber, can be affixed or is affixable in particular, to the first flow directing member, preferably in a detachable manner.
The embodiments of the present invention are thus based on the surprising finding that on the one hand, at least one first stationary flow directing member, for example, in the form of a standard air directing plate, is used in the interior of a cooking appliance, in order to separate the interior into a pressure chamber and a cooking chamber, wherein the first flow directing member leaves free a central suction port and at least one blow-off port on the edge side, and is affixed to the wall of the interior, while on the other hand, at least one second flow directing member is used, which fulfils or performs the function of a nozzle and which extends from a fan wheel in the pressure chamber, to which it is attached or molded together, through the suction port of the first flow directing member, so that the second flow directing member turns with the fan wheel. In a particularly advantageous manner, the nozzle, in particular, in the form of a ring is attached to a support ring for the blades of a radial fan, or is formed from a plurality of blade extensions. In any case, due to the nozzle, which rotates with the fan wheel, a radial flow is avoided in the suction area of the fan wheel, and thus, a short-circuit flow is also prevented. This increases the efficiency of the fan wheel and reduces the sensitivity of the entire cooking appliance to size tolerances.
Because radial fans are in principle relatively compact and are highly efficient, they are preferably used with a flow directing device according to the embodiments of the present invention. The high pressure area (the pressure side of the fan) and the suction area (the suction side of the fan) of a radial fan are relatively close to each other, so that due to the nozzle on the radial fan, a significant increase in fan capacity or reduction in the consumption capacity of the fan motor, is provided.
When the nozzle and the blades of the radial fan are affixed to a shared shaft, a separate fan housing is no longer required. The air directing plate and the nozzle, together with a wall of the interior, which is arranged opposite the air directing plate, form a type of fan housing. However, it is preferred that a shield is provided over the suction area of the radial fan in the cooking chamber in order to avoid injury, and is preferably attached to the first flow directing member.
Due to the size and geometry of the nozzle, further advantages can be attained, namely for the targeted directing of the flow. If the nozzle extends, on the one hand, in the pressure chamber into the area in which the blades of the radial fan create a pressure increase, the quantity of short-circuit flow is further reduced. If, on the other hand, the nozzle extends into the cooking chamber, an eddy formation in the suction area of the radial fan is reduced.
It is preferred according to the embodiments of the present invention that a third flow directing member is also used, which ensures that in the blow-off area of the radial fan, the pressure chamber comprises a chamber that extends radially outwards, so that the third flow directing member acts as a diffuser and further reduces the occurrence of short-circuit flows. The third flow directing member can be realised together with the first flow directing member.
Further features and advantages of the embodiments of the present invention are explained in the description of exemplary embodiments below with reference to the accompanying figures described below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a partial profile view of a cooking appliance according to an embodiment of the present invention;
FIG. 2 shows an enlarged view of detail AA in FIG. 1 ; and
FIG. 3 shows a perspective view of an alternative fan wheel for a cooking appliance according to an embodiment of the present invention.
DETAILED DESCRIPTION
A cooking appliance according to the embodiments of the present invention comprises, as is shown in FIG. 1 , an interior 1 , which houses a fan wheel 2 in the form of a radial fan wheel. The fan wheel 2 is mounted on a drive shaft 3 of a motor (not shown), which is located outside the interior 1 . If, as an alternative, the motor were to be located inside the interior 1 , then cooling measures would be required.
Although in principle, an axial fan could also be used, a radial fan has the advantage that atmosphere, which is brought into rotation, in particular cooking chamber atmosphere, does not impact against a rear wall 4 of the interior 1 , but is instead deflected into the fan wheel 2 . As a result, the arrangement is compact and has a high degree of efficiency.
The fan wheel 2 sucks in atmosphere centrally, namely, from a suction area 5 , (see the suction flow E in FIG. 1 ), and blows it off radially, namely, into a blow-off area 6 , (see the blow-off flow A in FIG. 1 ). In principle, a variant would also be feasible in which the atmosphere flows in the reverse direction, wherein measures would then have to be provided in order to avoid a transverse flow in the blow-off area 6 .
The interior 1 is divided by a first flow directing member, for example, in the form of an air directing plate 7 , at least partially into a cooking chamber 8 and a pressure chamber 9 . The air directing plate 7 is, for example, affixed in a detachable and lockable manner via bridges or bars (not shown) to the walls of the interior 1 . The fan wheel 2 is mounted separately in the cooking appliance, namely, with the fan wheel 2 in the pressure chamber 9 , without a fixed connection to the air directing plate 7 . The air directing plate 7 leaves gaps 10 a on its outer edges open for the blow-off flow A and comprises a central opening 10 b for the suction flow E, which is regulated in accordance with the suction area 5 .
Due to the circulation of the atmosphere in the interior 1 , evened heating of the item of food to be cooked (not shown) in the cooking chamber 8 is possible after the atmosphere has been heated using a heating means (not shown), both in conventional ovens and baking and roasting ovens, which also have a steam function and/or microwave charge, for example. The heating means can be designed in the form of heating coils around the fan wheel 2 , for example.
In order to improve the deflection of atmosphere from the suction area 5 into the fan wheel 2 , and to avoid transverse and counterflows, which could lead to short-circuit flows that could negatively impact the capacity of the fan, a nozzle 11 is provided as a second flow directing member in the area of the opening 10 b of the air directing member 7 on the fan wheel 2 . The nozzle 11 primarily directs atmosphere in the axial direction into the fan wheel 2 . As is shown in FIG. 1 , atmosphere is predominantly sucked in in the radial edge area of the suction area 5 of the fan wheel 2 in the form of a main flow H, for which reason the nozzle 11 is not only matched in terms of its arrangement and size to the suction area 5 , but also to the opening 10 b of the air directing plate 7 .
The fan wheel 2 comprises blades 12 . The end of each blade 12 , which, from the perspective of the axial direction, is located on the suction side of the fan wheel 2 , is here restricted by a ring-shaped wall 13 of a support ring, which is part of the fan wheel 2 and which is thus affixed on the shaft 3 in such a manner that it rotates. The nozzle 11 as depicted in the exemplary embodiment shown in FIG. 1 , is firmly attached to this support ring or to this ring-shaped wall 13 and is itself in the form of a ring, so that a continuous sealing off of the pressure chamber 9 against the main flow H is provided. As a result, transverse and counterflows are to a large extent avoided in the area of the main flow H.
In an alternative embodiment, the nozzle can be affixed in another manner to the fan wheel for the purpose of avoiding the aforementioned transverse and counterflows. In principle, it would be possible, for example, to mount the nozzle onto an extension of the shaft in such a manner that it either rotates or does not rotate, which, however would require a precise maintenance of tolerance limits in terms of the distance between the fan wheel and the nozzle, which should be kept as small as possible. This, however, would not be advantageous. By contrast, it is advantageous to mold the nozzle in the form of additional blades that extend from the wall 13 in the direction of the air directing plate 7 , or that extend as extensions of the blades 12 , which extend through the wall 13 in the direction of the air directing plate 7 . This embodiment enlarges the suction area 5 of the fan wheel 2 while maintaining the same installation space. Furthermore, the conveyance capacity of the fan wheel 2 is also enlarged, so that the cooking speed is increased or the capacity of the fan drive can be reduced. At the same time, the ejection behaviour of the fan wheel 2 is improved due to the fact that the profile through which the flow moves is enlarged when the fan wheel 2 is left. Due to the larger profile through which the flow moves, circulation around the heating means is also more effective, which leads to an improved heating of the item of food to be cooked.
Whether the nozzle 11 is in the form of a ring or in the form of a plurality of blade extensions on the support ring wall 13 , has no influence over the fact that the opening 10 b of the air directing plate 7 can be relatively freely selected, and the cooking appliance is no longer dependent to a high degree on tolerances with regard to the flow directing members 7 , 11 .
With regard to FIG. 2 , the progression of the various flows between the pressure chamber 9 and the cooking chamber 8 will now be described in detail.
In the area between the fan wheel 2 , which rotates when in operation, and the air directing plate 7 , there is a gap 14 . The gap 14 here is of such a size that it is guaranteed that the rotating fan wheel 2 together with the nozzle 11 under no circumstances brushes against the air directing plate 7 , which does not rotate. The dimensions of the gap 14 are in a way dependent on the production tolerances of both the air directing plate 7 or its opening 10 b, of the fan wheel 2 or its blades 12 , of the wall 13 , and of the nozzle 11 . The gap 14 opens a connection between areas with large pressure differences that leads to a counterflow G, which separates from the blow-off flow A, and which flows from the pressure chamber 9 into the cooking chamber 8 , more precisely from the blow-off area 6 of the fan wheel 2 into its suction area 5 . In order for this counterflow G to run first radially in the pressure chamber 9 in the direction of the rotation axis of the fan wheel 2 , then essentially axially in the area of the air directing plate 7 , and finally radially outwards in the cooking chamber 8 in order to avoid to the greatest extent possible an interaction with the main flow H, i.e. to form no short-circuit flow, the nozzle 11 extends from the perspective of the axial direction until at least up to the opening 10 b in the air directing plate 7 . In order to prevent the counterflow G from immediately flowing back into the suction area 5 , the nozzle 11 itself protrudes through the opening 10 b into the cooking chamber 8 . Furthermore, the counterflow G is deflected away in the radial direction from the suction flow E by the nozzle 11 widening out towards the suction area 5 . The radius of the edge 15 of the nozzle 11 , which faces away from the cooking chamber 8 , is by contrast larger than the radius of the opening 10 b in the air directing plate 7 . As a result, the flow resistance of the gap 14 is increased, on the one hand, and on the other hand the strength of an eddy formation and the volume of the counterflow G, is are reduced.
In order to prevent the rotating nozzle 11 from touching objects located in the cooking chamber 8 , such as an oven rack or similar structures, an air permeable shield 16 is provided. This shield 16 , which can be, for example, in the form of a grid or screen, is attached to the air directing plate 7 and also serves to protect against injury by preventing access to the fan wheel 2 .
An eddy formation can be further reduced in one embodiment according to embodiments of the present invention by the use of a third flow directing member in the form of an additional air directing plate 17 which functions as a diffuser. The additional air directing plate 17 can be mounted onto the first air directing plate 7 or be molded with the first air directing plate 7 . In any case, a distance B 1 between the additional air directing plate 17 and the rear wall 4 of the pressure chamber 9 is increased radially outwards relative to the longitudinal axis of the shaft 3 (rotation axis of the fan wheel), at least in the blow-off area 6 . The blow-off flow A, which flows out of the fan wheel 2 thus reaches the blow-off area 6 without significant changes to its profile, and flows onwards to the gaps 10 a between the first air directing plate 7 and the interior wall, wherein due to the flow directing mechanisms, eddy formations are avoided and short-circuit flows are reduced.
The invention is not restricted to the embodiments described in detail herein, but can be varied within the scope of protection of the appended claims. For example, the edge 15 of the nozzle 11 can protrude into a recess formed by a branching of the first and/or second air directing plate 7 , 9 for the purpose of further increasing the resistance experienced by the counterflow G.
An alternative fan wheel, or radial fan wheel 210 is shown in FIG. 3 and comprises a disc-shaped bearing disc 212 , several main blades 214 , which are affixed on the bearing disc 212 with the same degree of separation, and a support or bearing ring 218 , which is equipped with directing blades 216 and which is affixed at a distance to the bearing disc 212 on the main blades 214 .
The bearing disc 212 is provided with a central recess 220 , wherein a central axis of the recess 220 corresponds with a central axis 222 of the bearing disc 212 . In an area located radially in the interior, the bearing disc 212 , which is produced from a plate board, is provided with a hub designed to guarantee a reliable attachment to a drive device (not shown) and a stable radial runout of the radial wheel 210 , even under high rotational speeds. The main blades 214 are with the present embodiment arranged in such a manner that they incline backwards on the bearing disc 212 . In other words, a rotational speed vector 224 , which is applied tangentially on the outer circumference of the bearing disc 212 , incorporates an acute angle with a largest surface 226 of the main blade 214 , as is shown symbolically in FIG. 3 .
With the embodiment of the radial wheel 210 shown in FIG. 3 , the directing blades 216 are designed as a single piece with the main blades 214 so that largest surfaces of the directing blades 216 incorporate the same acute angle with the rotational speed vector 224 as the largest surfaces 226 of the main blades 214 . The main blades 214 are in each case angled at right-angles on an end area, which is set opposite the directing blades 216 , so that they can be affixed by adhesive bonding, for example, by glueing or spot-welding, to the bearing disc 212 which is preferably made of metal.
The directing blades 216 protrude orthogonally from the surface of the bearing disc 212 .
The bearing ring 218 is provided with slits, not shown in greater detail, which are punctuated by the directing blades 216 , which are connected as a single piece with the main blades 214 . The directing blades 216 are affixed using a adhesively bonded connection, in particular a weld or solder connection, to the bearing ring 218 , and protrude orthogonally from said ring. Radially external front sides of the main blades 214 and of the directing blades 216 are with the present embodiment of the radial wheel, aligned orthogonally to a largest surface 230 of the bearing disc 212 . Radially internal front sides 232 of the main blades 214 are curved, and thus only essentially aligned orthogonally to the largest surface 230 of the bearing disc 212 .
As depicted in FIG. 3 , the bearing ring 218 of the present embodiment, is designed as a single piece, made of a planar ring 234 and a suction mouth 236 , which connects radially internally, and is formed as a cone sheath section profile, and which provides a nozzle and thus also acts as a second flow directing member. The directing blades 216 are sized in such a manner that they extend from the radially external edge 238 of the planar ring 234 through to the radially internal edge 240 of the planar ring 234 . The inner edge 242 of the suction mouth 236 limits the suction profile of the radial wheel 210 .
Cooking chamber atmosphere that is sucked in by the radial wheel 210 and which flows through the suction port of a first flow directing member according to FIGS. 1 and 2 , is either directed through the suction mouth 236 , i.e., the second flow directing member, and accelerated outwards by the main blades 214 in the radial direction, or enters a gap, which remains between the suction mouth 236 and the first flow directing member. In the gap, the directing blades 216 ensure that unwanted turbulences, which could reduce the effectiveness of a fan arrangement that is equipped with the radial wheel 210 , are avoided. The directing blades 216 thus act as further flow directing members (fourth flow directing members) in order to increase the efficiency of the radial wheel 210 .
The features of the embodiments of the present invention explained in the above description, in the drawings and in the claims, can be integral both individually as well as in any combination required in order to realise the invention in its different embodiments.
LIST OF REFERENCE NUMERALS
1 Interior
2 Fan wheel
3 Shaft
4 Rear wall
5 Suction area
6 Blow-off area
7 Air directing plate
8 Cooking chamber
9 Pressure chamber
10 a Gap
10 b Opening
11 Nozzle
12 Blade
13 Support ring wall
14 Gap
15 Edge
16 Shield
17 Air directing plate
210 Radial wheel
212 Bearing disc
214 Main blade
216 Directing blade
218 Bearing ring
220 Recess
222 Central axis
224 Rotational speed vector
226 Surface
230 Surface
232 Front side
234 Planar ring
236 Suction mouth/nozzle
238 Radially external edge
240 Radially internal edge
242 Inner edge
H Main flow
G Counterflow
E Suction flow
A Blow-off flow
B 1 Distance
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A cooking appliance including an interior, a fan mechanism having at least one fan wheel in the interior, at least one first flow directing member for subdividing the interior into a pressure chamber that houses the fan wheel and a cooking chamber, in which the first flow directing member includes at least one suction port for sucking atmosphere from the cooking chamber into the pressure chamber when the fan wheel is in operation and at least one blow-off port for blowing atmosphere from the pressure chamber into the cooking chamber when the fan wheel is in operation; and at least one second flow directing member that is included with the fan mechanism in the area of the suction port of the first flow directing member in order to improve the flow from the cooking chamber into the pressure chamber by forcing an axial main flow H in the suction zone of the fan mechanism, where the second flow directing member performs a nozzle function, extends from the fan mechanism into the cooking chamber, and overlaps the edge of the suction port of the first flow directing member, and where the first flow directing member extends into the second flow directing member.
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BACKGROUND OF THE INVENTION
[0001] I. Field of the Invention
[0002] This invention relates generally to implantable medical devices for stimulating target tissue, and more particularly to, implantable pulse generators connecting to one or more elongated, electrode bearing leads and incorporating a locking mechanism for retaining a proximal end of the said lead in electrical and mechanical engagement with the input/output contacts of the pulse generator.
[0003] II. Discussion of the Prior Art
[0004] Dating back to the late 1950's and early 1960's, advances have been made in the treatment of patients through the application of electrical stimulation to target tissue from a pulse generator that is surgically implanted, subcutaneously or submuscellarly, within a patient. A medical lead, comprising an elongated, flexible, insulating lead body and having surface electrodes thereon at a distal end and flexible conductors extending through the lead body for connecting the electrodes to a proximal terminal, is used to deliver electrical stimulation from the device to tissue abutting the electrodes and, in the case of cardiac rhythm management devices, to convey depolarization signals picked up by the electrodes back to the pulse generator.
[0005] In a typical prior art design, the proximal terminal of the medical lead comprises a rigid, straight pin having one or more electrical contacts disposed along its length. The pulse generator, in turn, has a molded plastic or epoxy connecter affixed to a hermetically sealed housing containing a battery power supply and electronic circuitry for delivering pulses in accordance with control signals provided by a microprocessor-based controller. The input and output nodes of the electronic circuitry are connected by feed-through wires that pass through suitable seals and connect to contact rings in a terminal receiving bore formed in the connector. The contact rings in the connector are adapted to mate with the electrical contacts of the lead terminal when the lead terminal is properly inserted and locked in place in the connector.
[0006] In the beginning, the implantable pulse generators were generally the size of a hockey puck. With improvements in circuit design and integrated circuitry, cardiac pacemakers and spinal cord stimulators are presently about the size of a silver dollar and about four times as thick. Efforts are still underway to further reduce the size and thickness of the implantable devices to render them less noticeable cosmetically. One design feature that has made it difficult to reduce the thickness dimension of such devices is the lead securing mechanism used in the header of the pulse generator.
[0007] In a typical prior art design, the lead locking mechanism comprises a block or blocks of metal disposed in the connector and having a longitudinal bore(s) for receiving the proximal end portion of the lead's proximal terminal therein. A threaded, transversely-extending bore that intersects with the longitudinal bore is also provided in the block for receiving a set screw. Once the proximal lead terminal is inserted into the longitudinal bore of the block comprising the locking mechanism, the setscrew is tightened down against the terminal in one or more locations. This forces the terminal pin into intimate contact with the wall of the longitudinal bore. Such a locking device mandates a connector whose thickness must be sufficient to contain the block of the locking member, the setscrew and a seal plug assembly used to prevent ingress of bodily fluids through the threaded bore. Such a construction typically drives a connector thickness of at least 7 mm. The prior art design also requires the use of a torquing tool to advance the setscrew.
[0008] It is also advantageous that one be able to replace a pulse generator without also having to replace the medical lead. Industry standards have been established for lead terminals in terms of their size (diameter and length), the location of contacts and location of insulation and seals. Therefore, any lead locking mechanism in a pulse generator should be such that it cooperates with a portion of the terminal that is in compliance with the standard, such as the proximal tip portion of the lead.
[0009] The present invention offers a lead lock mechanism that allows for a thinner connector than has heretofore been possible to achieve using setscrew technology. Moreover, the lead lock mechanism of the present invention does not require any special tools to effect locking. Also, the lead lock mechanism of the present invention is designed to accommodate any medical leads conforming to a given international standard.
SUMMARY OF THE INVENTION
[0010] The instant invention provides a tool-less connector for an implantable medical device. The device may include an implantable pulse generator contained within a hermetically sealed housing and that has a connector affixed to a predetermined surface of the housing. The header includes first and second side surfaces and a front surface. At least one longitudinally extending bore is formed inwardly from the front surface and is adapted to receive a proximal terminal of a medical lead therein. The proximal terminal of the lead has a conductive pin at a proximal end thereof. At least one electrical contact is disposed in the connector. It is positioned to cooperate with the conductive pin of the lead terminal when the proximal terminal of the lead is fully inserted into the longitudinal bore in the header. First and second side ports extend inwardly from the first and second side surfaces of the connector and the side ports intersect with the longitudinal bore at a location that is in general alignment with the electrical contact. An elastomeric tube is inserted through one of the first and second side ports. In accordance with the present invention, a first latch member is adapted to be inserted through the first side port. The first latch member includes a pair of bifurcated legs that extend into the lumen of the elastomeric tube. Completing the arrangement is a second latch member that is insertable through the second side port into the lumen of the elastomeric tube. The second latch member has a tapered wedge surface that is adapted to spread the bifurcated legs of the first latch member apart and thereby press the elastomeric tube against the conductive pin of the lead. The force applied is sufficient to hold that conductive pin in place against the electrical contact when the first and second latch members are squeezed together, such as by being pinched between the physician's thumb and forefinger.
DESCRIPTION OF THE DRAWINGS
[0011] The foregoing features, objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of a preferred embodiment, especially when considered in conjunction with the accompanying drawings in which like numerals in the several views refer to corresponding parts.
[0012] FIG. 1 is a side elevation of a prior art implantable tissue-stimulating device over which the present invention is an improvement;
[0013] FIG. 2 is an isometric view of an implantable tissue stimulator device incorporating the tool-less lead locking mechanism of the present invention in an exploded form;
[0014] FIG. 3 is an isometric view of a first latch member shown in FIG. 2 ;
[0015] FIG. 4 is a side elevation of the first latch member of FIG. 3 ;
[0016] FIG. 5 is an isometric view of a second latch member shown in FIG. 2 ; and
[0017] FIG. 6 is a greatly enlarged transverse cross-section taken through the header of the implantable tissue stimulator incorporating the novel lead locking mechanism of the present invention illustrating the locking engagement of the first and second latching members.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] Referring to FIG. 1 , there is indicated generally by numeral 10 a prior art tissue stimulating device, such as a cardiac rhythm management device or a nerve stimulator. It is seen to comprise a hermetically sealed housing 12 which will typically contain a battery and electronic circuitry for producing pulses of preprogrammed amplitude, duration and repetition rate dictated by a microprocessor-based controller forming a part of the electronic circuit contained within the hermetically sealed housing 12 . The tissue-stimulating device 10 has a molded plastic connector 14 affixed to it and formed longitudinally in the connector is a lead receiving bore 16 into which the terminal portion 18 of a medical lead 20 is inserted.
[0019] As is well known in the art, the lead 20 comprises an elongated, flexible, plastic lead body 22 having one or more electrodes, as at 24 and 26 , proximate its distal end. These electrodes are connected by elongated flexible conductors (not shown) that extend through the lead body 24 and are insulated from one another. The conductors connect to contacts as at 28 and 30 , disposed on the proximal terminal 18 of the lead. Sealing rings on the lead, as at 32 and 34 , interface with the wall of the bore 16 to prevent ingress of body fluids into the bore of the connector 14 .
[0020] In accordance with the prior art, the implantable device 10 will include a locking mechanism in the connector for preventing disengagement of the contact areas 28 and 30 on the lead terminal 18 from mating contacts contained in the bore 16 . A typical prior art lead lock comprises a block of metal 36 having a longitudinal bore 38 formed therethrough, that bore being intersected by a transversely extending threaded bore 40 . Fitted into the threaded bore 40 is a setscrew 42 . An elastomeric plug is fitted into the bore 40 , again to prevent ingress of body fluids into the interior of the connector. At the time of implant, the setscrew is tightened using a torquing tool inserted through the elastomeric plug so as to tightly press the contact 30 on the lead against the wall of the bore 38 . Once the setscrew has been tightened down,
[0021] It can be appreciated from what has thus far been described that this prior art approach mandates a relatively wide connector, i.e., about 8 mm, in order to accommodate the locking block 36 a predetermined number of threads of the setscrew and a seal plug. Moreover, as mentioned, the implanting physician must be provided with an appropriate torquing tool, such as an Allen wrench, for tightening the setscrew.
[0022] Referring next to FIG. 2 , there is shown an implantable tissue-stimulating device incorporating the novel lead locking mechanism of the present invention. Again, the pulse generator 50 includes a hermetically sealed housing 52 having a molded plastic connector 54 affixed to a planar surface 56 of the housing. The connector 54 has a front surface 58 and opposed side surfaces 60 and 62 . Formed inward from the front surface 58 are lead receiving bores 64 and 66 which, as in the prior art design, are adapted to receive the proximal terminal of a pair of medical leads therein.
[0023] A first side port 68 extends inwardly from the side surface 60 of the connector to intersect with the longitudinal bores 64 and 66 . In a similar fashion, a second side port 70 ( FIG. 6 ) is formed inwardly of the side surface 62 of the connector to also intersect with the longitudinal bores 64 and 66 . An elastomeric tube or sleeve, preferably formed from silicon rubber and of one piece continuous construction is identified by numeral 72 . It is inserted through one of the first and second side ports to be centered crosswise in the connector and the tube 72 includes a lumen 74 . When the elastomeric tube is inserted in the manner shown in FIG. 2 , its outer periphery does not appreciably occupy the bores 64 and 66 .
[0024] With continued reference to FIG. 2 , associated with each of the bores 64 and 66 is a metal contact. More particularly, a metal contact 76 is associated with the bore 66 and a metal contact 78 is provided in the bore 64 . Each of the contacts 76 and 78 has a semicircular recess formed therein whose radius is only slightly larger than the radius of the terminal contact 30 on the medical lead 20 ( FIG. 1 ). As such, upon insertion of the lead terminals into the longitudinal bores 64 and 66 , the contact 30 of the lead terminal inserted into the bore 64 will fit into the semicircular recess of the contact 78 and slightly depress the elastomeric sleeve 72 . Likewise, as a lead terminal is inserted into the bore 66 , its contact 30 will fit into the semicircular recess of the contact 76 while again slightly compressing the elastomeric sleeve 72 .
[0025] To lock the leads in place against their respective contacts 76 - 78 and thereby prevent the leads from coming loose in the connector, a first latching member 80 is inserted into the lumen 74 from the side 60 of the connector and a second latching member 82 is inserted into the lumen 74 of the sleeve from the side 62 . Retention features on lumen 74 , latching members 80 and 82 , and on header 54 allow the device 50 to be shipped with 80 and 82 partially engaged. This minimizes any assembly by the physician. As will be explained in greater detail herein below, when the first and second latching members are squeezed together against the respective side surfaces 60 and 62 , the elastomeric sleeve 72 is radially expanded to thereby firmly press the contacts 30 of the medical lead against the respective contacts 76 and 78 located in the connector. This provides electrical connection between the lead and connector. Additionally, the resulting frictional forces are such that the lead terminal contacts are able to remain in place even when substantial pulling forces are applied to the leads. Moreover, the elastomeric sleeve 72 forms a seal with the latching members 80 , 82 and connector 54 to prevent ingress of body fluids into the interior of the header.
[0026] Referring next to FIG. 3 , there is shown an isometric view of the first latching member 80 shown in FIG. 2 . It is seen to comprise a molded plastic part having a head member 84 in the form of a oval disk with a slightly convex face 86 and generally flat base 88 . Integrally formed with the head member 84 and projecting generally perpendicular from the base 88 are legs 90 and 92 . The legs 90 and 92 have a somewhat flat outer surface 94 with radiused side edges 96 and 98 . Projecting outward from the surfaces 94 at the end of each of the legs is a protuberance 100 and 102 . Also rising from the surface 94 of each of the legs is a series of elongated knobs as at 104 . An aperture 106 is formed through the thickness dimension of the head 84 at the center thereof and longitudinally aligned with this aperture and projecting inwardly from each of the legs 90 and 92 are latches 108 and 110 ( FIG. 5 ).
[0027] Turning next to FIG. 5 , there is an isometric view of the second latching member 82 . It, too, comprises a generally oval-shaped head member 112 having a slightly convex outer face 114 and a generally flat interface 116 . Integrally molded with and projecting outwardly from the interface 116 is a wedge member 118 that tapers in thickness (from thicker to thinner) in progressing from the head 112 to the free ends of the wedge member 120 . Formed inwardly from the free end 120 is a cut-out that defines first and second arms 122 and 124 that are spaced from one another and positioned on either side of a center post 126 . Each of the arms 122 and 124 has a beveled surface 127 terminating in a shoulder 128 to form a barb. The cut-out in the wedge member 118 also defines inwardly projecting fingers 130 and 132 that are directed toward one another but separated by a gap. The fingers thereby result in the formation of latch surfaces 134 and 136 .
[0028] FIG. 6 is a transverse cross-section view taken through the locking mechanism with the latching members 80 and 82 fully engaged and latched. it can be seen that the wedge-shaped center post 126 serves to spread the legs 90 and 92 of the latching member 80 apart, thus compressing the elastomeric sleeve 72 against the lead terminals 30 to bring the lead terminals 30 in firm engagement with the contacts 76 and 78 . The protuberances 100 and 102 of the latching member 80 engage a shoulder formed in the lumen 74 of the sleeve 72 and that the barbs on fingers 130 and 132 mate with latches 108 and 110 of the member 80 , inhibiting separation of the latching members. The two pieces 80 and 82 may then be dismayed by a physician by inserting a tool or common torque wrench through orifice 106 in member 80 . During insertion of the tool or torque wrench, tabs 130 and 132 are separated by the tool and flexing of legs 122 and 124 . With the locking tabs spread apart, further insertion of the tool brings it into contact with center post 126 , thus allowing the user to push out latching member 82 and disengage the latch. Barbs 128 and protuberances 100 and 102 prevent the latching mechanisms 80 and 82 , respectively, from coming out.
[0029] This invention has been described herein in considerable detail in order to comply with the patent statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use such specialized components as are required. However, it is to be understood that the invention can be carried out by specifically different equipment and devices, and that various modifications, both as to the equipment and operating procedures, can be accomplished without departing from the scope of the invention itself.
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A device-to-lead terminal connector for an implantable medical device is designed to positively lock the proximal lead terminal within a lead bore formed in the connector of the implantable device. Rather than using a conventional setscrew locking arrangement, first and second latching members are insertable through side ports in the device connector that intersect with the lead bore and that contain an elastomeric sleeve. When the latching members are squeezed together, they cooperate to expand the elastomeric sleeve against the proximal lead terminal to press it into intimate electrical and mechanical engagement with a contact in the lead bore of the device connector. The need for a tool to effect locking of the lead terminal in place is dispensed with.
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BACKGROUND OF THE INVENTION
The present invention relates to a sequential chromatographic procedure for the purification of a human tumor necrosis factor, produced, by the LuKII cell line, termed TNF(LuKII), the characterization of TNF(LuKII) and hybridoma cell lines producing monoclonal antibodies to TNF(LuKII).
It has been reported that during certain bacterial infections, for example, staphylococcal and streptococcal, there sometimes occurs a concomittant regression of human tumors.
Coley and others treated human malignancies with heat-killed bacterial vaccines and obtained positive results in some patients.
The presence of a tumor inhibitory factor in the sera of mice infected with bacillus Calmette-Guerin (BCG) and subsequently injected with endotoxin was reported by E. A. Carswell et al, Proc. Natl. Acad. Sci. U.S.A., 72, 3666-3670 (1975). This sera has been observed to cause the hemorrhagic necrosis and regression of certain mouse tumors in vivo. This sera was also found to have cytotoxic/cytostatic effects on mouse and human tumor cells in vitro (E. A. Carswell et al, supra; L. Helson, et al, Nature (London), 258, 731-732 (1975); D. N. Mannel et al, Infect. Immun., 28, 204-211 (1980); F. C. Kull and P. Cuatrecasas, J. Immunol., 126, 1279-1283 (1981); K. Haranaka and N. Satomi, Jpn. J. Exp. Med., 51, 191-194 (1981)). A similar factor was found to be induced in rats (Carswell et al, supra) and rabbits (Carswell et al, supra, N. Matthews and J. F Watkins, Br. J. Cancer, 38, 302-309 (1978); J. M. Ostrove and G. E. Gifford, Proc. Soc. Exp. Biol. Med., 160, 354-358 (1979)).
The antitumor factor present in the sera of animals sensitized to BCG or other immunopotentiating agents, such as Corynebacterium parvum, Malaria or Zymosan (yeast cell wall), and then challenged with endotoxin has been termed tumor necrosis factor (TNF).
Biochemical studies have indicated that mouse serum TNF is a glycoprotein and that its activity is associated with both high molecular weight components, e.g., M r 150,000, (Kull and Cuatrecasas, supra and S. Green et al, Proc. Natl. Acad. Sci U.S.A., 73, 381-385 (1976)) and components in the M r 40,000-60,000 range, (D. N. Mannel et al, supra; Kull and Cuatrecasas, supra; and Haranaka, supra). The molecule is stable when frozen, preferably below -70° C. Its activity is destroyed at 70° C. for 30 minutes. It is pyrogenic in rabbits in a range from 5-500 microgram/kg and non-pyrogenic at 5 microgram/kg. TNF in rabbit serum has also been reported to have a molecular weight of 39,000, (N. Matthews et al, Br. J. Cancer, 42, 416-422 (1980)), and 67,000, (M. R. Ruff and G. E. Gifford, J. Immunol., 125, 1671-1677 (1980)).
Studies have indicated that both in vivo and in vitro activities of mouse TNF appear to be a property of the same molecule. The cellular source of TNF in the mouse was initially assumed to be the macrophage, because the agents used to prime for TNF production cause massive hyperplasia of macrophages in liver and spleen (Carswell et al, supra). From studies of macrophage-rich cell populations in vitro, (N. Matthews, Br. J. Cancer, 38, 310-315 (1978) and D. N. Mannel et al, Infect. Immun., 30, 523-530 (1980)) a similar conclusion was reached with regard to the source of mouse and rabbit TNF. Direct evidence that macrophages are at least one cell type in the mouse capable of producing TNF comes from studies with cloned lines of mouse histiocytomas (D. N. Mannel et al, supra and unpublished data). These cells constitutively produce low levels of TNF that are greatly increased after exposure to endotoxin.
B. D. Williamson et al, Proc. Natl. Acad. Sci. U.S.A., 80, 5397-5401 (1983), described the capacity of human cell lines of hematopoietic origin, e.g., B-cell lines, to produce a factor with TNF activity. The product of one of the B-cell lines (LuKII) was chosen for detailed studies. Evidence demonstrating that this molecule is a human TNF included the following: (1) the anticellular response of a panel of human cell lines to human TNF, e.g., TNF(LuKII), or mouse TNF are indistinguishable and can be potentiated in a synergistic fashion by interferon, (2) mouse L cells made resistant to mouse TNF are resistant to human TNF, e.g., TNF (LuKII), (3) mouse L cells made resistant to human TNF, e.g., TNF(LuKII) are resistant to mouse TNF , and (4) human TNF, e.g., TNF(LuKII), causes hemorrhagic necrosis of Method A sarcoma in the standard in vivo TNF assay, B. D. Williamson, supra.
Heretofore, there have been no known purification methodologies to obtain pure TNF(LuKII) which are rapid and efficient, for example, which do not require dialysis which may involve serious losses of material. At the present time there is also no hybridoma in existence which produces a monoclonal antibody to the pure TNF(LuKII), which would be extremely useful for purification, diagnostic, and perhaps therapeutic purposes.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide a process for the purification of TNF(LuKII) which yields both good recoveries of TNF activity and high specific activity material. The pure TNF(LuKII) can be used therapeutically.
It is another object of the present invention to isolate this TNF(LuKII) in a form suitable for producing hybridoma cell lines which produce monoclonal antibodies to TNF(LuKII), to allow for the rapid purification and detecting of the presence of TNF(LuKII) for diagnostic purposes.
This and other objects and advantages are realized in accordance with the present invention pursuant to which a purified TNF(LuKII), i.e., a human TNF having an activity of at least 1.5×10 5 units per milligram of total protein is obtained by contacting a TNF-containing protein composition, which has been harvested from human cell lines (e.g., human cell lines of hematopoietic origin, particularly B-cell lines such as the LuKII cell line) or produced by recombinant technologies, in separate adsorption stages with glass beads, lentil lectin bound to Sepharose, and procion red agarose, thereby selectively to adsorb TNF in each stage while leaving some impurities unadsorbed, each contact stage being followed by contact of the adsorbent with an eluant thereby to obtain a solution of more highly purified TNF after each stage. In a preferred process for obtaining purified TNF, the glass beads are the first stage adsorbent, the Sepharose-bound lentil lectin is the second stage adsorbent and the procion red agarose is the third stage adsorbent.
The purification process of the present invention allows the TNF(LuKII) eluted from one column to be applied, either directly or after dilution, onto the next column, thereby eliminating any need for dialysis and thus avoiding the losses associated with dialysis.
The TNF which is purified to obtain the TNF of the invention can be harvested from human cell lines of hematopoietic origin, particularly B-cell lines. Recombinant methodologies can also be used to produce a TNF-containing composition. For example, the gene responsible for TNF(LuKII) production can be implanted in E.coli which, in turn, produce TNF(LuKII) in large quantities. The recombinant techniques used are known (e.g., T. Maniatis et al, Molecular Cloning, Cold Spring Harbor Laboratory, 1982).
The purified TNF(LuKII) of the invention comprises a plurality of fractions of protein molecules of different molecular weights, each of which, it is believed, has TNF activity. More particularly, the TNF(LuKII) comprises at least three fractions. Even more particularly, the TNF(LuKII) comprises seven fractions, each of which, it is believed, has TNF activity.
The purified TNF(LuKII) of the invention may have different numbers of protein fractions, each fraction having a different molecular weight. For example, the TNF(LuKII) of the invention may have two fractions, for example, corresponding to the molecular weights of, for example, 70,000 and 25,000 daltons, respectively; or, the TNF(LuKII) of the invention may have three fractions, for example, corresponding to the molecular weights of, for example, 70,000, 25,000 and 19,000 daltons, respectively; or the TNF(LuKII) of the invention may have seven fractions corresponding to the molecular weights of 80,000; 70,000; 43,000; 25,000; 23,000; 21,000; and 19,000 daltons, respectively.
The TNF(LuKII) of the invention is further characterized in having a specific activity of at least 1.5×10 5 units per milligram of total protein, e.g., 1.5×10 5 to 1.5×10 8 units per milligram of total protein, more particularly, 1.5×10 6 to 1.5×10 8 , and even more particularly, about 1.5×10 7 units per milligram of total protein.
The TNF(LuKII) of the invention can contain chemically bound carbohydrate moieties, for example, glycosyl groups.
As described above, the inventive TNF(LuKII) comprises a plurality of protein fractions, e.g., at least three of and as many as seven or perhaps even more fractions which it is believed will have TNF activity. No matter how many fractions are obtained, each such protein fraction constituting the TNF(LuKII) is disruptable upon contact with enzymes such as trypsin or chymotrypsin to produce tryptic or chymotrypic digested proteins. At least one such protein fragment generated by enzyme digestion of each given protein fraction and at least one fragment generated by digestion of any other protein fraction or fractions, migrate to the same position following two dimensional analysis on a cellulose coated glass plate. Fragments generated following enzyme digestion of 70K and 25K proteins, for example, migrate to the same position on two dimensional peptide mapping analysis and are thus, related. In particular, two of the fragments generated by trypsin digestion of the 70K protein and two of the fragments generated by digestion of the 25K protein migrate to the same position upon two dimensional peptide mapping analysis, i.e., peptide homology. Peptide mapping analysis also shows that the 43K , 25K, 23K, 21K and 19K proteins, for example, are related, as are the 80K and 70K proteins.
In accordance with another aspect of the invention, several protein fractions of the inventive TNF(LuKII), having a different molecular weight, are recognized by monoclohal antibodies of the invention, produced by hybridomas, for example, ATCC HB 8887, deposited on Aug. 14, 1985.
In accordance with another aspect of the invention, the TNF(LuKII), which has a specific activity of 1.5×10 5 to 1.5×10 8 units per milligram of total protein, is in vitro cytotoxic or cytostatic, or has no effect on various human tumor cell lines.
For example, cytotoxic effects of hTNF on the following cell lines have been shown: SK-MG-4 (astrocytoma), MCF-7 (breast cancer), BT-20 (breast cancer), SK-BR-3 (breast cancer), ME-180 (cervix cancer), SK-CO-1 (colon cancer) and RPMI 7931 (melanoma).
Cytostatic effects of hTNF on the following cell lines, for example, have also been shown: SK-LU-1 (lung cancer), RPMI 4445 (melanoma), SK-MEL-29 (melanoma), SK-MEL-109 (melanoma) and SK-OV-3 (ovary cancer).
The present invention also concerns a method of producing monoclonal antibodies against TNF(LuKII) by propagating a hybridoma cell line which secretes such monoclonal antibody and harvesting secreted antibody.
Another aspect of the invention relates to a method of assaying a sample for the presence of TNF(LuKII), which comprises contacting the sample with a monoclonal antibody against TNF(LuKII), separating the antibody with any TNF(LuKII) which has combined therewith, and assaying the separated antibody for the presence of any TNF(LuKII) combined therewith. For example, using monoclonal antibodies of the invention, both enzyme linked immunosorbent assays and radioimmunoassays, can be used to detect the presence of TNF(LuKII) in a sample.
Two particular methods of assaying a sample for the presence of TNF(LuKII) are as follows:
(1) Competitive Method
An antibody, e.g., a monoclonal antibody, having an affinity to TNF(LuKII) is coated on a substrate, e.g., glass beads. Such coated beads are contacted with an unknown sample suspected of containing TNF(LuKII). Labelled TNF, e.g., radiolabelled or enzyme labelled, is allowed to contact the coated bead and unknown sample. Washing is then conducted. The amount of labelled TNF(LuKII) that binds is effected by any TNF(LuKII) in the unknown sample (unlabelled TNF(LuKII)). If there is no TNF(LuKII) in the sample, all the labelled TNF(LuKII) binds. The more TNF(LuKII) in the sample, the less labelled TNF(LuKII) binds. To determine the binding of the labelled TNF(LuKII), counts are taken if the label is a radiolabel and if an enzyme label is utilized, the enzymatic activity is determined.
(2) Non-Competitive Method
A substrate, e.g., polystyrene beads, is coated with an antibody, e.g., a monoclonal antibody having an affinity for TNF(LuKII). The coated beads are then contacted with an unknown sample suspected of containing TNF(LuKII). The bead is then washed and a labelled antibody having an affinity for TNF(LuKII) is then allowed to contact the bead. Washing is then conducted. The amount of antibody bound to the bead is a reflection of the TNF(LuKII) in the sample. If there is no TNF(LuKII) in the sample, there is no binding of the antibody. The more TNF(LuKII) in the sample, the greater the binding of the antibody. The TNF(LuKII) acts as a bridge between the labelled antibody and the unlabelled antibody.
The monoclonal antibodies of the invention can also be used to obtain the purified TNF(LuKII) of the invention. For example, a monoclonal antibody can be immobilized on a solid support, e.g., attached to Sepharose beads in a column, and the crude TNF(LuKII) passed through the column and the column washed with buffers. Immobilized TNF(LuKII) bound to the monoclonal antibody is then dissociated therefrom by using a dissociation buffer.
The invention also relates to the treatment of a patient having a tumor by administering to such patient a tumor-necrotic or a regression-effective amount of TNF(LuKII) of the invention, i.e., having a specific activity of at least 1.5×10 5 units per milligram of protein, more particularly, 1.5×10 5 to 1.5×10 8 units per milligram protein, more particularly, 1.5×10 6 to 1.5×10 8 and even more particularly, about 1.5×10 7 units per milligram of total protein.
DESCRIPTION OF THE DRAWINGS
The invention will be further described with reference to the accompanying drawings wherein:
FIG. 1a is a chromatograph of media conditioned by the LuKII cell line, containing TNF(LuKII), on a controlled pore glass column. LuKII culture media (8 liters) containing 200 units/mL of TNF(LuKII) was applied to a controlled pore glass column (50 mL) equilibrated with phosphate buffered saline (20 mM sodium phosphate, pH 7.0, 0.15M NaCl) (PBS). The column was washed with the following buffers in sequence: PBS (75 mL), PBS containing 20% ethylene glycol (v/v) (E 1 ) (225 mL), PBS (120 mL), 20 mM sodium phosphate, pH 7.0, containing 1.15 M NaCl (PBS+1M NaCL) (E 2 ) (175 mL), PBS (50 mL), 5 mM sodium phosphate, pH 6.8, (E 3 ) (225 mL), and 5 mM sodium phosphate, pH 6.8, containing 5% triethylamine (v/v) (E 4 ) (150 mL). Eluted fractions were collected in polypropylene bottles. The material eluted with the E 4 buffer was collected in 50 mL aliquots.
FIG. 1b is a lentil lectin Sepharose column chromatograph of TNF(LuKII) purified by controlled pore glass chromatography. 150 mL of the partially purified TNF(LuKII) eluted from the controlled pore glass column was loaded onto a lentil lectin sepharose column (10 mL) equilibrated with PBS. The column was washed sequentially with PBS (40 mL), PBS+1M NaCl (E 1 ) (24 mL), and PBS+1M NaCl containing 0.2M α-methyl-D-mannoside (E 2 ) (60 mL). The material eluted with the α-methyl-D-mannoside containing buffer was collected in 10 mL aliquots.
FIG. 1c is a procion red agarose column chromatograph of the TNF(LuKII) purified sequentially first on a controlled pore glass column and then on a lentil lectin sepharose column. 60 mL of partially purified TNF(LuKII) eluted from the lentil lectin column was diluted 1:1 with PBS and loaded onto a procion red agarose column (4 mL) equilibrated with 20 mM sodium phosphate, pH 6.8, 0.65M NaCl (PBS+0.5M NaCl). The column was washed with the following buffers in sequence: PBS+0.5M NaCl (E 1 ) (30 mL), PBS+1M NaCl (E 2 ) (8 mL), PBS (8mL), PBS containing 50% ethylene glycol (v/v) (E 3 ) (8 mL), PBS (8mL), 0.1M Tris-HCl, pH 9.4+0.1M NaCl (E 4 ) (8 mL), and 0.1M Tris-HCl, pH 9.4+0.1M arginine (E 5 ) (24 mL). The material eluted with the 0.1M Tris-HCl, pH 9.4+0.1M arginine buffer was collected in 4 mL aliquots.
FIG. 2 is a graph indicating the isoelectric point of TNF(LuKII). A 60 μL sample of purified TNF(LuKII) containing 1500 units was applied to a pH 3.5-9.5 ampholine gel.
FIG. 3 is an autoradiograph resulting from NaDodSO 4 polyacrylamide gel electrophoresis (PAGE) of purified 125 I-labeled TNF(LuKII). TNF(LuKII) was iodinated and fractionated by NaDodSO 4 /PAGE. Autoradiographs were developed for 18 hours (lane 1) and 0.5 hour (lane 2). The following proteins provided Mr markers: myosin (200,000), β-galactosidase (130,000), phosphorylase b (94,000), bovine serum albumin (67,000), ovalbumin (43,000), α-chymotrypsinogen (25,700), β-lactoglobulin (18,400), lysozyme (14,300) and cytochrome C (12,300).
FIG. 4 is a graph showing recovery of TNF(LuKII) activity after NaDodSO 4 /PAGE fractionation of TNF(LuKII). A sample of TNF(LuKII) containing 6000 units adjusted to contain 0.1% NaDodSO 4 and 0.1M β-mercaptoethanol was applied to a 12% polyacrylamide gel. Following electrophoresis, the gel was sliced and activity eluted and assayed. In an adjacent track, 125 I-labeled TNF(LuKII) was fractionated and autoradiographed to determine the Mr of the TNF(LuKII) active fractions.
FIGS. 5a and 5b are tryptic peptide maps of 125 I-labeled proteins in purified TNF(LuKII). 125 I-labeled TNF(LuKII) was fractionated on NaDodSO 4 /PAGE and individual protein bands present in gel slices were incubated overnight in the presence of 50 μg/mL of L-1-tosylamido-2-phenylethyl chloromethyl ketone-(TPCK)-treated trypsin. The individual gel slices were then washed with water and 10,000 CPM samples of each lyophilized to dryness. These samples were dissolved in a buffer containing formic acid and acetic acid and applied to cellulose pre-coated glass TLC plates at the origin (x). Electrophoresis was performed from right to left followed by ascending chromatography in a buffer containing butanol, pyridine and acetic acid. Autoradiographs of the tryptic maps of the Mr 80,000, 70,000, 43,000, 25,000, 23,000, 21,000 and 19,000 proteins are presented in FIG. 5a. FIG. 5b shows tryptic maps of the Mr 25,000, 70,000 and a mixture of the 25,000 and 70,000 proteins.
FIGS. 6a and 6b are chymotryptic peptide maps of 125 I-labeled proteins in purified TNF(LuKII). 125 I-labeled proteins present in the purified TNF(LuKII) preparation were processed as described in FIG. 5, except that for this digestion, 50 μg/mL of N-α-tosyllysine chloromethyl keton(TLCK)-treated chymotrypsin was used. Autoradiographs of the chymotryptic maps of the Mr 80,000, 70,000, 43,000, 25,000, 23,000, 21,000 and 19,000 proteins are presented in FIG. 6a. FIG. 6b shows chymotryptic maps of the Mr 25,000, 70,000, and a mixture of the Mr 25,000 and 70,000 proteins.
FIG. 7 shows the results of immunoblotting analysis of TNF(LuKII) with T1-18 mouse monoclonal antibody. A sample of TNF(LuKII) containing 10,000 units of TNF(LuKII) was fractionated by NaDodSO 4 /PAGE. Fractionated proteins were transferred to a nitrocellulose membrane and processed.
The invention will be further described in the following illustrative non-limiting examples wherein all parts are by weight unless otherwise expressed.
DETAILED DESCRIPTION OF INVENTION
Examples
Example 1
Production of Tumor Necrosis Factor
LuKII cells (a cell line of B-cell origin) were obtained as described in Pickering., L. A., Kronenberg, L. H. & Stewart, W. E., II, Proc. Natl. Acad. Sci U.S.A., 77, 5938-5942 (1980), and were cultured in the following manner in order to obtain human tumor necrosis factor produced by the LuKII cells [i.e., TNF(LuKII)]:
LuKII cells (8×10 5 cells/ml) were placed in RPMI 1640 media containing 8% fetal calf serum (FCS) with 10 ng/ml of mezerein (L.C. Services, Woburn, Mass.) for 48 hours. The cells were then removed from the media by centrifugation, resuspended in fresh RPMI 1640 media lacking any protein supplement and allowed to incubate for an additional 48 hours. Cells were removed by centrifugation, and the culture media used as the source of TNF(LuKII).
Example 2
Purification of TNF(LuKII)
Human TNF(LuKII) was purified sequentially using controlled pore glass, lentil lectin Sepharose and procion red agarose column chromatography as follows (all affinity chromatography procedures were carried out at room temperature and all column fractions were collected in polypropylene tubes or bottles):
The TNF(LuKII) culture fluid was applied to a column of controlled pore glass-350 (Electronucleonics, Fairfield, N.J.) which bound all of the TNF activity. The column was washed with several buffers in sequence (as described in the legend to FIG. 1a) and then the TNF activity was eluted with a 5 mM sodium phosphate buffer, pH 6.8, containing 5% triethylamine (FIG. 1a). The eluted TNF was then applied to a lentil lectin Sepharose column (Pharmacia, Piscataway, N.J.), which was then washed first with phosphate buffered saline (PBS) followed by a 0.02M sodium phosphate buffer, pH 6.8, containing 1.15M NaCl (PBS+1M NaCl). TNF activity was then eluted from this column with PBS+1M NaCl buffer containing 0.2M α-methyl-D-mannoside (FIG. 1b). All TNF activity bound to the lentil lectin Sepharose column and 39% of the activity was recovered in the α-methyl-D-mannoside-containing buffer. The further washing of the column with the above buffer containing 50% ethylene glycol eluted only a small amount of TNF activity TNF from the lentil lectin column was then diluted 1:1 with PBS and loaded onto a procion red agarose column (Bethesda Research Laboratory, Bethesda, Md.). The column was washed sequentially with several buffers (as described in the legend to FIG. 1c) which removed protein having no TNF activity. The column was then washed with 0.1M tris-HCl, pH 9.4, containing 0.1M arginine. The TNF activity was eluted with this buffer, yielding TNF with a specific activity of 1.5×10 7 units/mg of protein. Table 1 summarizes the purification scheme for TNF(LuKII) with specific activities of the resulting fractions.
TABLE I__________________________________________________________________________Purification of TNF(LukII) Load Recovery (Specific (Specific Load Activity) Recovery Activity) % FoldColumn (units) μ/mg (units) μ/mg Recovery Purification__________________________________________________________________________ControlledPore Glass 1.6 × 10.sup.6 5.3 × 10.sup.3 9.6 × 10.sup.5 3.8 × 10.sup.5 60% 72XLentil LectinSepharose 9.6 × 10.sup.5 3.8 × 10.sup.5 6.3 × 10.sup.5 1.3 × 10.sup.6 39% 245XProcion RedAgarose 6.3 × 10.sup.5 1 × 10.sup.6 6.3 × 10.sup.5 1.5 × 10.sup.7 39% 2830X__________________________________________________________________________
Example 3
Preparation of Monoclonal Antibody to TNF(LuKII)
BALB/c mice were injected with 1600 units of purified TNF(LuKII), with a specific activity of 1.5×10 7 units/mg. For the initial injection, TNF(LuKII) was mixed with Freund's complete adjuvant (1:1) and injected subcutaneously. Subsequent injections were given intraperitoneally in the absence of adjuvant. Serum antibody to TNF(LuKII) was determined by an enzyme linked immunosorbent assay (ELISA) in which the TNF(LuKII) was bound to polystyrene plates. After nine immunizations over a period of seven months, the spleen of one mouse with a high titer antibody directed against TNF(LuKII) was removed and fused with cells of the P 3 U 1 mouse plasmacytoma cell line Resulting clones were screened for their ability to bind TNF(LuKII) in ELISA assays. A hybridoma (designated T1-18) producing antibody reactive with TNF(LuKII) was isolated and subcloned. This hybridoma grown in tissue culture media as well as in ascites served as a source of TNF(LuKII) antibody. The hybridoma has been deposited with the ATCC as HB 8887, deposited on Aug. 14, 1985.
Example 4
Biochemical Characterization of Purified TNF(LuKII)
To initiate the characterization of the purified TNF(LuKII), isoelectrofocusing was performed using Ampholine Pagplates (pH 3.5 to 9.5) LKB Instruments, Gaitherburg, Md.). The gels were run at 30 watts for 1.5, hours at which time the pH gradient was measured. Human TNF was found to have an isoelectric point of approximately 6.7 (see FIG. 2). The gel was sliced into 18 equal pieces. The gel fractions were incubated for 18 hours in Eagle's Minimum Essential Medium (MEM) containing 10% fetal calf serum, and fractions were assayed for the presence of TNF(LuKII) in vitro.
Purified TNF(LuKII) was tested and was observed to cause hemorrhagic necrosis of the Meth A mouse sarcoma in the standard in vivo TNF assay. The in vivo TNF assay was performed as described (Williamson B. D. et al, supra). Essentially, (BALB/c×C57BL/6)F 1 female mice were injected intradermally with 5×10 5 Meth A BALB/c' sarcoma cells. After 7 days (tumor size approximately 7 mm average diameter), mice received either a single intravenous or intratumoral injection of the TNF(LuKII) preparation. After 24 hours, tumor hemorrhagic necrosis was scored according to Carswell et al, supra. TNF(LuKII) causes hemorrhagic necrosis of Meth A sarcoma after intraturmoral or intravenous injection and total tumor regression has been observed in some treated mice.
The in vitro assay for TNF was performed in 96-well microtiter plates. Serially diluted fractions were sterilized by ultraviolet radiation and the TNF-sensitive L cells (for example, derived from mouse L cells obtained from American Type Culture Collection) were added to each well at a density of 2×10 4 cells/well in 100 μL. After two days at 37° C., the plates were examined by phase-contrast microscopy and the percentage of dead cells was determined. The unitage of the samlle was calculated as the reciprocal of the highest dilution that killed 50% of the cells. All TNF assays were run in parallel with a laboratory standard and titers are expressed in laboratory units.
Purified TNF(LuKII) was iodinated as follows:
TNF(LuKII) was labeled with 125 I using 1,3,4,6-tetrachloro-3α, 6α-diphenylglycouril (Iodo-gen, Pierce Chemical Co., Rockford, Ill.) as follows. Polypropylene tubes were coated with 100 μg of Iodo-gen (dissolved in chloroform) by evaporation of the solvent. A 2 ml sample of TNF(LuKII) (50,000 units/ml) with a specific activity of 1.5×10 7 units/mg of protein was incubated for 25 minutes at room temperature in an Iodo-gen coated tube containing 2 mCi of 125 I. The labeled protein was then separated from the unbound 125 I using a P-4 column (Bio-Rad, Richmond, Calif.) equilibrated with phosphate buffered saline (PBS) containing 50 μg/mL of cytochrome-C. The iodinated material eluted in the void volume of the column was divided into aliquots and stored at -80° C.
Following iodination, the radioactively labelled proteins present in the preparations were analyzed by NaDodSO 4 /polyacrylamide gel electrophoresie (PAGE) which was performed in 18 cm slab gels according to conditions described by Laemmli, U.K. (1970), Nature (London), 227, 680-685.
All protein determinations were made using the Bio-Rad dye reagent (Bio-Rad, Richmond, Calif.), using bovine serum albumin as a standard.
As can be seen in FIG. 3, the purified preparation of TNF(LuKII) contained seven protein bands with molecular weights of 80,000, 70,000, 43,000, 25,000, 23,000, 21,000 and 19,000 daltons (80K, 70K, 43K, 25K, 23K, 21K, 19K). The same seven protein bands were observed when non-labeled purified TNF(LuKII) was fractionated by NaDodSO 4 /PAGE and examined by the silver staining of the gel. The Mr 80,000 and 70,000 forms were eluted from the gels and re-analyzed by NaDodSO 4 /PAGE. They migrated once again to the Mr 70,000-80,000 region and no smaller molecular weight components were observed. In further experiments, purified TNF(LuKII) was boiled in NaDodSO 4 , urea and β-mercaptoethanol and the same characteristic seven bands were found.
In order to ascertain which of the protein bands present in the purified TNF(LuKII) preparations was responsible for TNF activity, parallel samples of purified TNF(LuKII), one 125 I-labeled and one unlabeled, were treated with NaDodSO 4 (0.1%) and β-mercaptoethanol (0.1M) and then fractionated by NaDodSO 4 /PAGE. Upon completion of the electrophoresis, the lane containing the unlabeled TNF(LuKII) was cut into 4.4 mm slices and the slices put into Eagle's minimal essential media (MEM) containing 10% fetal calf serum (FCS). The proteins were then eluted from each gel slice by overnight incubation at 4° C. in MEM containing FCS. The samples were assayed for the presence of TNF as described above.
The parallel lane containing 125 I-labeled TNF(LuKII) was dried immediately following the completion of the electrophoresis and the protein bands located by autoradiograpy. As can be seen in FIG. 4, TNF activity was recovered from the gel at molecular weights of approximately 70,000 and 19,000 to 25,000 daltons, corresponding to 125 I-labeled protein bands at these positions. In experiments in which β-mercaptoethanol was not added to the TNF(LuKII) sample before NaDodSO 4 /PAGE, TNF activity was also recovered at the 70,000 and 19,000 to 25,000 molecular weight range.
Since it was observed that following NaDodSO 4 /PAGE, TNF activity was recovered at the 70,000 as well as the 19,000 to 25,000 dalton region, the relatedness of the various proteins present in the purified TNF(LuKII) preparations was then examined. To accomplish this, two dimensional chymotryptic and tryptic peptide mapping analyses of the individual protein bands present in the most purified TNF(LuKII) preparations were performed.
To perform the peptide mapping, an 125 I-labeled preparation of purified TNF(LuKII) was fractionated by NaDodSO 4 /PAGE and individual bands (i.e., 80K, 70K, 43K, 25K, 23K, 21K, 19K) localized by autoradiography were cut from the gel and treated with either TPCK treated trypsin or TLCK treated chymotrypsin. Digested fractions were then analyzed according to the methods of J. H. Elder et al, Nature (London), 267, 23-28 (1977).
As seen in FIG. 5a, the tryptic peptide maps demonstrate that the 43K, 25K, 23K, 21K and 19K proteins are related and that the 80K and 70K proteins are related. To examine the relationship between the larger molecular weight proteins (e.g., 70K and 80K) and the smaller molecular weight proteins (e.g., 19 to 25K), tryptic digests of the 70K and 25K proteins were mixed so that they contained equal amounts of radioactivity and the mixture was analyzed by peptide mapping analysis. As seen in FIG. 5b, two of the fragments (termed A and B) generated by digestion of the 70K protein and two of the fragments generated by digestion of the 25K protein overlap, i.e., migrate to the same position upon peptide mapping analysis. A similar analysis was carried out using chymotrypsin as the proteolytic enzyme. As seen in FIG. 6a, the 43K, 25K, 23K, 21K and 19K proteins are related and the 80K and 70K proteins are related. To once again examine the relatedness between the smaller and larger molecular weight proteins, the chymotrypsin digests 25K and 70K proteins were mixed and the mixture analysed by peptide mapping analysis. As seen in FIG. 6b, at least three of the fragments generated (termed A, B and C) following chymotrypsin digestion of the 25K protein migrate to the same position as three of the fragments generated by digestion of the 70K protein.
Further evidence for the relationships among the various proteins in purified TNF(LuKII) comes from immunoblotting analyses with T1-18 monoclonal antibody to TNF(LuKII). Western blotting analysis was performed essentially as described in Burnette, W. N. (1981), Anal.Biochem., 112, 195-203. Briefly, preparations of purified TNF(LuKII) were fractionated by NaDodSO 4 /PAGE and the proteins present in the gel were transferred to nitrocellulose paper overnight at 100 mA. Following incubation of the nitrocellulose paper in a buffer containing bovine serum albumin (BSA), the nitrocellulose paper was exposed for two hours to 40 mL of T1-18 monoclonal antibody-containing culture medium. The nitrocellulose paper was then washed extensively and incubated overnight in 10 mM Tris-HCl, pH 7.4, +0.9% NaCl containing 5% BSA and 125 I-labeled rabbit anti-mouse IgG. The nitrocellulose paper was further washed and exposed to X-ray film.
As seen in FIG. 7, exposure of this nitrocellulose paper to the X-ray film reveals that the monoclonal antibody to TNF(LuKII) reacts with proteins with molecular weights of 43K and 19K to 25K, thus showing shared determinants on the Mr 43,000 and 19-25,000 proteins. Antibody did not react with the higher molecular weight forms, even though these have been shown to be related to the Mr 43,000 and lower molecular weight components. This could be due to the inaccessability of the determinant on the Mr 70,000 and 80,000 species. Thus, analysis indicates that there are a number of structural related proteins in purified TNF(LuKII) and that TNF activity is associated with nondissociable high molecular weight and low molecular weight forms. It is concluded that the seven proteins in the purified TNF(LuKII) are the products of related genes or products of a single gene that undergoes extensive processing.
Thus, using peptide map analyses, and a monoclonal antibody to human TNF in western blotting analysis it has been demonstrated that the various molecular weight proteins present in the purified TNF(LuKII) preparations are related.
Example 5
The Relationship of Mouse TNF to TNF(LuKII)
A standard lot of partially purified mouse serum TNF with a specific activity of 2×10 4 units of TNF per mg of protein was used in these studies. A unit of TNF is defined as the amount of protein causing killing of 50% of the L cells in the standard in vitro TNF assay.
To investigate further the relationship of mouse TNF to TNF(LuKII), L cells were made resistant to TNF(LuKII) by repeated passage in TNF(LuKII)-containing medium. TNF(LuKII)-resistant cells showed complete cross-resistance to mouse TNF. L cell lines made resistant to mouse TNF or to partially purified TNF(LuKII) are resistant to purified TNF(LuKII). TNF(LuKII) is cytotoxic to mouse L cells sensitive to mouse TNF.
It will be appreciated that the instant specification and claims are set forth by way of illustration and not limitation, and that various modifications and changes may be made without departure from the spirit and scope of the present invention.
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Human TNF(LuKII) having a specific activity of at least 1.5×10 5 units per milligram of total protein is produced by contacting a TNF-containing protein composition, which has been harvested from human cell lines of hematopoietic origin or recombinant origin, in separate adsorption stages with glass beads, lentil lectin bound to Sepharose, and procion red agarose, thereby selectively to adsorb TNF in each stage, while leaving some impurities unadsorbed, each contact stage being followed by contact of the adsorbent with an eluant thereby to obtain a solution of more highly purified TNF after each stage. The purified human TNF(LuKII) is used to produce monoclonal antibodies against TNF(LuKII) and such antibodies can be used to assay samples for the presence of TNF(LuKII).
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FIELD OF THE INVENTION
The present invention relates to a magnetic recording medium, and more particularly it relates to a magnetic recording medium having excellent running durability.
BACKGROUND OF THE INVENTION
A strong demand has arisen for a magnetic recording medium having a higher recording density. One approach to meet this demand is to make the surface of the magnetic layer smooth. However, when the surface of the magnetic layer is made smooth, the friction coefficient between the magnetic layer and the tape running system increases as the magnetic recording medium runs. This results in the magnetic layer being easily damaged or the magnetic layer being easily peeled off in a short period of its use.
In the case of a video tape, the magnetic layer is put under harsh conditions, such as during a still mode. Under such harsh conditions, ferromagnetic particles easily come off from the magnetic layer. This causes the magnetic head gap bridging (head clogging).
Conventionally, abrasive agents (hard particles) such as corundum, silicon carbide, chromium oxide, etc. are added to the magnetic layer to improve the running durability of the magnetic layer. In the case when abrasive agents are added to the magnetic layer to improve the running durability of the magnetic layer, a comparatively large amount thereof must be added to exhibit its abrasive effects However, the addition of such large amounts of the abrasive agents to the magnetic layer causes great wear on the magnetic head. Moreover, such is unfavorable for smoothing the surface of the magnetic layer so as to improve the electromagnetic properties.
It is also proposed that a fatty acid or an ester of a fatty acid and an aliphatic alcohol is added as a lubricating agent to the magnetic layer to reduce the friction coefficient.
With the recent increasing usage of portable video tape recorders and flexible disk drive apparatuses for personal computers, the magnetic recording medium is expected to be used under various conditions such as at a low temperature or at a high temperature and a high humidity. Accordingly, the running durability of the magnetic recording medium must be stable so as not to change under various conceivable conditions. The above-described conventional lubricating agents are not satisfactory for this purpose.
In video tapes and floppy disks, as the size of the magnetic recording medium is minimized by shortening the recording wavelength, as well as the track width, ferromagnetic alloy particles are more increasingly used than iron oxide type ferromagnetic particles as a material for the magnetic composition, and those having a smaller particles size are increasingly used. In this way, relatively excellent electromagnetic properties can be obtained by radically minimizing the size of the magnetic particles, but it is difficult to simultaneously achieve excellent running durability.
As a result of investigations as to lubricating agents to avoid the above-described disadvantages, it was found that stable running durability, which is stable even under harsh conditions such as at a high temperature and a high humidity or at a low temperature and a low humidity, can be obtained by incorporating an alkane sulfonate or an alkyl sulfate into a magnetic layer. (U.S. patent application Ser. No. 033,704 filed on Apr. 3, 1987). However, an alkane sulfonate or an alkyl sulfate generally have a low solubility in an organic solvent and therefore crystals are deposited on the magnetic layer. This causes video head gap bridging, particularly at a low humidity.
Examples of the magnetic recording medium containing an alkane sulfonate as a lubricating agent are described in Japanese Patent Publication No. 12949/72, but the characteristics thereof are not fully satisfactory.
SUMMARY OF THE INVENTION
An object of the present invention is, therefore, to provide a magnetic recording medium having excellent electromagnetic properties, running durability which is stable even under various conditions of temperatures and humidities, and having reduced occurrences of head gap bridging.
The above and other objects have been met by the present invention which relates to a magnetic recording medium comprising a non-magnetic support having provided thereon a magnetic layer containing ferromagnetic particles and a binder, wherein the magnetic layer contains at least one compound selected from the group consisting of an ammonium sulfate and an ammonium sulfonate.
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, the ammonium sulfate and the ammonium sulfonate are preferably those compounds represented by formula (I). ##STR1## Wherein R 1 represents a saturated hydrocarbon group having from 10 to 24 carbon atoms, R 2 through R 5 each represents a hydrogen atom or a hydrocarbon group having from 1 to 22 carbon atoms, and n represents 0 or 1.
More preferably, the ammonium sulfate and the ammonium sulfonate are those represented by formula (I) wherein R 1 represents a saturated hydrocarbon group having from 16 to 24 carbon atoms, R 2 through R 5 each represents a hydrocarbon group having from 1 to 22 carbon atoms provided that at least one of R 2 through R 5 represents a saturated hydrocarbon group having from 16 to 22 carbon atoms, and n represents 0 or 1.
The non-magnetic supports used in the present invention may be those commonly used.
Examples of the non-magnetic supports include various synthetic resin films such as polyethylene terephthalate, polypropylene, polycarbonate, polyethylene naphthalate, polyamide, polyamide imide, or polyimide, and metal foils such as aluminum foil or stainless steel foil. The thickness of the support is generally from 3 to 50 μm, and preferably from 5 to 30 μm.
A backing layer may be provided on the surface of the support opposite to the surface provided with the magnetic layer.
Examples of the backing layer include those described in U.S. Pat. Nos. 4,474,843, 4,273,797, 4,419,406, 4,135,031, 4,544,601, and 4,567,083.
It is necessary that the ammonium sulfate or an ammonium sulfonate be incorporated in the magnetic layer of the magnetic recording medium of the present invention. The ammonium sulfate or ammonium sulfonate may be contained uniformly inside of the magnetic layer and preferably is contained locally on the surface of the magnetic layer. Non-limiting examples of the ammonium sulfate or ammonium sulfonate are illustrated as follows. ##STR2##
It is preferred that the solution of ammonium sulfonate or ammonium sulfate is top-coated on the magnetic layer in view of reducing the friction coefficient. The ammonium sulfonate or ammonium sulfate is dissolved in a solvent such as water, methanol, acetone, a mixed solvent of water and methanol, a mixed solvent of water and acetone, etc., and then top-coated on the magnetic layer by an air doctor coating method, a blade coating method, a rod coating method, an extruding coating method, an air knife coating method, a squeeze roll coating method, a transfer roll coating method, a gravure coating method, a kiss coating method, a cast coating method, a spray coating method, a spin coating method or a bar coating method. The coated amount of the top-coated layer is preferably from 10 to 500 mg/m 2 , more preferably from 20 to 200 mg/m 2 . When the ammonium sulfonate or ammonium sulfate is incorporated in the magnetic coating composition, the additive amount thereof is preferably from 0.01 wt % to 10.0 wt %, more preferably from 0.05 wt % to 6 wt %, based on the amount of the ferromagnetic particles.
The ferromagnetic particles used in the present invention are not limited. Examples thereof include ferromagnetic alloy particles, γ-Fe 2 O 3 , Fe 3 O 4 , Co-modified iron oxide, CrO 2 , modified barium ferrite, and modified strontium ferrite.
The shape of the ferromagnetic particles is not particularly limited, and an acicular shape, a granular shape, a cubic shape, a rice grain shape, a tabular shape, etc. are used. The specific surface area of the ferromagnetic particles is preferably 30 m 2 /g or more, and more preferably 45 m 2 /g or more in view of the electromagnetic properties.
Examples of the binders used for forming the magnetic layer include those conventionally used, such as a copolymer of vinyl chloride and vinyl acetate, a copolymer of vinyl chloride and vinyl acetate with vinyl alcohol, maleic acid and/or acrylic acid, a copolymer of vinyl chloride and vinylidene chloride, a copolymer of vinyl chloride and acrylonitrile, a copolymer of ethylene and vinyl acetate, cellulose derivatives (e.g., a nitrocellulose resin), an acrylic resin, a polyvinyl acetal resin, a polyvinyl butyral resin, an epoxy resin, a phenoxy resin, a polyurethane resin, and a polycarbonate polyurethane resin.
The total amount of the binders included in the magnetic layer of the magnetic recording medium of the present invention is generally from 10 to 100 parts by weight, and preferably from 20 to 40 parts by weight per 100 parts by weight of the ferromagnetic particles.
It is preferred that inorganic particles having a Mohs' hardness of 5 or more are included in the magnetic layer of the magnetic recording medium of the present invention.
The inorganic particles used in the present invention are not particularly limited so long as the inorganic particles have a Mohs' hardness of 5 or more. Examples of the inorganic particles having a Mohs' hardness of 5 or more include Al 2 O 3 (Mohs' hardness of 9), TiO (Mohs' hardness of 6), TiO 2 (Mohs' hardness of 6.5), Cr 2 O 3 (Mohs' hardness of 9) and α-Fe 2 O 3 (Mohs' hardness of 5.5). They may be used alone or in combination.
Inorganic particles having a Mohs' hardness of 8 or more are particular preferred. When relatively soft inorganic particles having a Mohs' hardness of 5 or less are used, the inorganic particles readily come off from the magnetic layer and do not function well as an abrasive agent, thereby causing head gap bridging and poor running durability.
The content of inorganic particles is generally from 0.1 to 20 parts by weight, and preferably from 1 to 10 parts by weight per 100 parts by weight of ferromagnetic particles.
It is also preferred that carbon black having an average particles size of from 10 to 300 nm is included in the magnetic layer in addition to the above-described inorganic particles. The preferred amount of the carbon black is from 1 to 50 wt % based on the amount of the ferromagnetic particles. The most preferred amount of the carbon black varies depending on the purpose of the recording medium, and tends to decrease with the increase of the recording density.
A method for preparing the magnetic recording medium of the present invention is illustrated hereinafter, referring to the case when an ammonium sulfonate or ammonium sulfate is included in the magnetic coating solution.
First of all, ferromagnetic particles, binders, the above-described ammonium sulfonate or ammonium sulfate and, if necessary, fillers and additives are mixed and kneaded with a solvent to prepare a magnetic coating solution. The solvents generally used for preparing the magnetic coating solution are used upon mixing and kneading.
The methods for mixing and kneading are not limited, and the order of adding each component can be optionally selected.
The mixing and kneading devices are those generally used, such as a two-roll mill, a three-roll mill, a ball mill, a pebble mill, a high speed impellor dispersing device, a high speed stone mill, a high speed impact mill, a disper, a kneader, a high speed mixer, a homogenizer, an ultrasonic dispersing device or the like.
The conventionally known additives such as a dispersing agent, an antistatic agent, a lubricating agent, etc. can be used in combination upon preparing the magnetic coating solution.
Examples of the dispersing agents include a fatty acid having from 12 to 22 carbon atoms such as caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, beheic acid, oleic acid, elaidic acid, linolic acid, linolenic acid or stearol acid; a metal soap composed of the above fatty acid and an alkali metal (e.g. Li Na, K, and Ba); an ester of the above fatty acid, an ester of the above fatty acid wherein a part of or all of the hydrogens are substituted with fluorine atoms, an amide of the above fatty acid, an aliphatic amine, a higher alcohol, a polyalkylene oxide alkylphosphate, an alkylphosphate, an akkylborate, a sarcosinate, an alkyl ether ester, a trialkylpolyolefin, an oxyquaternary ammonium salt, and a lecithin.
The preferred amount of dispersing agents added is from 0.1 to 10 parts by weight per 100 parts by weight of the ferromagnetic particles.
Examples of the antistatic agents used in the present invention include electroconductive fine particles such as carbon black and carbon black graft polymer; natural surface active agents such as saponin; nonionic surface active agents such as an alkylene oxide type surface active agent, a glycerine type surface active agent, and a glycidol type surface active agent; cationic surface active agents such as a higher alkyl amine, a quarternary ammonium salt, pyridine and other heterocyclic compounds (e.g., pyridine), a phosphonium, and a sulfonium; anionic surface active agents such as a compound having an acidic group, e.g., a carboxyl group, a phosphoril group, and a phosphate group; and amphoteric surface active agents such as an amino acid, an amino sulphonic acids, and a sulfate or a phosphate of an aminoalcohol.
When the above electroconductive particles are used as the antistatic agent, they are preferably used in an amount of from 0.1 to 10 parts by weight per 100 parts by weight of the ferromagnetic particles. When the above surface active agents are used as the antistatic agent, they are preferably used in an amount of from 0.12 to 10 parts by weight per 100 parts by weight of the ferromagnetic particles.
Examples of lubricating agents other than those according to the present invention include esters composed of a monobasic fatty acid having from 12 to 20 carbon atoms and an alcohol having from 3 to 20 carbon atoms such as butyl stearate and sorbitanoleate, a mineral oil, an animal and vegetable oil, an olefin oligomer, a fatty acid amide, a silicone oil, a modified silicone oil, an alkyleneoxide adduct product of fatty acid, grafite particles, molybdenum disulfide, tetrafluoroethylene polymer particles, and lubricating agents for plastics known in the art. The amount thereof is preferably from 0.2 to 2.0 wt % based on the amount of the ferromagnetic particles. More preferably, the amount thereof is from 0.2 to 1.0 wt % based on the amount of the ferromagnetic particles for the silicone oils, and from 0.5 to 1.5 wt % based on the amount of the ferromagnetic particles for those other than silicone oils.
The above-described functions and effects of the above additives, such as dispersing agents, antistatic agents, and lubricating agents, are not decisive, and it may be that, for example, a dispersing agent also functions as a lubricating agent or as an antistatic agent. Accordingly, it is understood that the above classifications of the additives due to their functions are not decisive. If additives having multifunctions are used, the added amounts thereof is preferably determined in light of the multiple effects.
The thus prepared magnetic coating solution is coated on the above described non-magnetic support. The magnetic layer can be provided directly on the non-magnetic support or can be provided through an adhesive layer, etc. on the non-magnetic layer.
The methods for coating the magnetic layer on the non-magnetic support include an air doctor coating method, a blade coating method, a rod coating method, an extruding coating method, an air knife coating method, a squeeze coating method, an impregnating coating method, a reverse roll coating method, a transfer roll coating method, a gravure coating method, a kiss coating method, a cast coating method, a spray coating method, and a spin coating method, as well as any other method generally used in th art.
The method for dispersing the above ferromagnetic particles and the binder, and the method for coating the magnetic layer on the support are disclosed in detail in Japanese Patent Application (OPI) Nos. 46011/79 and 21805/79 (the term "OPI" as used herein means an "unexamined published application".)
The dry thickness of the magnetic layer is generally from about 0.5 to 10 μm, and preferably from 1.5 to 7.0 μm.
In the case when the magnetic recording medium of the present invention is used in the shape of a tape, the magnetic layer thus coated on the support may be subjected to magnetic orientation to have the ferromagnetic particles orientated and then dried. If necessary, the magnetic layer is subjected to surface smoothening treatment followed by cutting into a desired shape.
The present invention will be illustrated in more detail by the following Examples and Comparative Examples which do not limit the present invention. In the following Examples and Comparative Examples, all parts and percents are by weight unless otherwise indicated.
EXAMPLES 1 TO 7 AND COMPARATIVE EXAMPLES 1 TO 5
The following composition was mixed, kneaded and dispersed for 48 hours using a ball mill, 5 parts of poly isocyanate were added thereto, and mixed, kneaded and dispersed for another 1 hour. The dispersed solution was filtrated using a filter having an average pore diameter of 1 μm to prepare a magnetic coating solution. The resulting magnetic coating solution below was coated using a reverse roll on a polyethylene terephthalate support having a 10 μm thickness so that the dry thickness of the magnetic layer was 4.0 μm.
Composition of the magnetic coating solution
______________________________________Ferromagnetic alloy particles (composed of 100 partsFe 94%, Zn 4% and Ni 2%; Coerciveforce 1,500 Oe; specific surface area 54mg/m.sup.2)Copolymer of vinyl chloride, vinyl 12 partsacetate and maleic anhydride (400X110A,manufactured by Nippon Zeon Co., Ltd.,Degree of polymerization 400)Abrasive agent (α-alumina, average 5 partsparticle diameter 3 μm)Additive (Shown in Table 1)Stearic acid 1 partCarbon black (average particle 2 partsdiameter 40 nm)Methyl ethyl ketone 300 parts______________________________________
The non-magnetic support thus coated with the magnetic coating solution was subjected to magnetic orientation using magnets of 3,000 gauss while the magnetic coating solution was undried, then dried and was subjected to a super calendering treatment followed by being slit to a width of 8 mm to prepare a 8 mm video tape.
EXAMPLES 8 TO 12 AND COMPARATIVE EXAMPLES 6 TO 12
The following composition was mixed, kneaded and dispersed for 48 hours using a ball mill, 5 parts of poly isocyanate were added thereto, and mixed, kneaded and dispersed for another 1 hour. The dispersion was filtrated using a filter having an average pore diameter of 1 μm to prepare a magnetic coating solution. The resulting magnetic coating solution was coated using a reverse roll on a polyethylene terephthalate support having 10 μm thickness so that the dry thickness of the magnetic layer was 4.0 μm.
Composition of the magnetic coating solution:
______________________________________Ferromagnetic alloy particles (composed of 100 partsFe: 94%, Zn: 4%, and Ni: 2%; Coercive force1,500: Oe; Specific surface area: 54 mg/m.sup.2)Copolymer of vinyl chloride, vinyl acetate 12 partsand maleic anhydride (400X110A,manufactured by Nippon Zeon Co., Ltd.,Degree of polymerization: 400)Abrasive agent (α-alumina, average 5 partsparticle diameter: 3 μm)Stearic acid 1 partCarbon black (average particle 2 partsdiameter: 40 nm)Methyl ethyl ketone 300 parts______________________________________
The non-magnetic support thus coated with the magnetic coating solution was subjected to magnetic orientation using magnets of 3,000 gauss while the magnetic coating solution was undried, dried and was subjected to a super calendering treatment, and thereafter top-coated with a solution of the compound as shown in Table 2 using a bar coater followed by being slit to a 8 mm width to prepare a 8 mm video tape.
Signals of 7 MHz were recorded on the thus obtained tapes and reproduced using a VTR ("JUJIX-8", manufactured by Fuji Photo Film Co., Ltd.). The reproduction output signals were measured and were shown in terms of relative values when the reproduced output signal of a standard tape (Comparative Example 1) was assumed to be 0 dB.
The thus obtained video tapes were contacted with a stainless steel pole (winding angle: 180°) at a 50 g tension (T 1 ) and the condition, tension (T 2 ), necessary to make the video tape run at a speed of 3.3 cm/s was measured. The friction coefficient μ of the video tape was calculated by the following equation based on the measured values, (shown in Tables 1 and 2).
μ=1/π.ln(T.sub.2 /T.sub.1)
The above test of the friction coefficient was carried out under two conditions, that is, Condition (a) at 20° C. and 70% RH and Condition (b) at 40° C. and 80% RH.
Recording and reproducing were carried out using the above described VTR at 20° C. and at 10% RH, and the number of occurrences of head gap bridging was measured during reproducing for 30 minutes.
The results are shown in Tables 1 and 2.
TABLE 1__________________________________________________________________________ Repro- Friction Additive duction coefficient (μ) Head clogging amounts output condition condition (number ofSample Additive (parts) (dB) (a) (b) occurrences/30 min.)__________________________________________________________________________Example 1 (A) 2 +1 0.20 0.20 0Example 2 (B) 2 +1 0.18 0.20 0Example 3 (C) 2 +1 0.20 0.25 0Example 4 (D) 2 +1 0.22 0.26 0Example 5 (E) 2 +1 0.22 0.27 0Example 6 (F) 2 +1 0.19 0.21 0Example 7 (G) 2 +1 0.20 0.23 0Comparative (H) 2 +1 0.24 0.26 10-20Example 1Comparative Oleic acid 2 +1 0.26 0.37 0Example 2Comparative 2-ethylhexyl 2 0 0.26 0.35 0Example 3 myristateComparative Stearic acid 2 +0.5 0.25 0.35 5-10Example 4Comparative None -- 0 0.27 0.39 5-10Example 5__________________________________________________________________________
TABLE 2__________________________________________________________________________ Repro- Friction Compounds duction coefficient (μ) Head clogging to be Coating output condition condition (number ofSample top-coated Solvent (amount) (dB) (a) (b) occurrences/30 min.)__________________________________________________________________________Example 8 (A) methanol 25 +1 0.16 0.19 0Example 9 (B) methanol 25 +1 0.15 0.16 0Example 10 (C) methanol 25 +1 0.18 0.22 0Example 11 (D) methanol 25 +1 0.19 0.21 0Example 12 (E) methanol 25 +1 0.20 0.22 0Comparative (H) methanol 25 +1 0.22 0.27 5-10Example 6Comparative Oleic acid acetone 25 +1 0.30 0.31 0Example 7Comparative 2-ethylhexyl acetone 25 0 0.35 0.35 0Example 8 myristateComparative Stearic acid acetone 25 0 0.28 0.31 5-10Example 9Comparative None -- -- 0 0.35 0.37 5-10Example 10Comparative None (Only methanol -- 0 0.35 0.37 5-10Example 11 solvent was coated.)Comparative None (Only Acetone -- 0 0.35 0.37 5-10Example 12 solvent was coated.)__________________________________________________________________________
Compounds (A) to (H) added or coated are shown below. ##STR3##
It is clear from the results of Tables 1 and 2 that Examples 1 through 12 using the ammonium sulfonate or ammonium sulfate according to the present invention exhibit high outputs, low friction coefficient under both Conditions (a) and (b), and reduced head gap bridging at a low humidity.
On the other hand, in the case when the compounds of the present invention were not used, or only a fatty acid or an ester were used, the reproduced outputs were low and particularly there is a serious problem that the friction coefficient under a high temperature and a high humidity (Condition (b)) was high.
Further in case when a sulfate or a sulfonate other than those according to the present invention were used, an excellent friction coefficient was obtained, but there was a problem as to head gap bridging under the harsh condition of a low humidity.
As stated in the foregoing, the magnetic recording medium of the present invention not only exhibits a high output but also has excellent still life as well as running durability, and further exhibits a low friction coefficient under a wide range of conditions of temperatures and humidities and improved head gap bridging at a low humidity.
While the invention has been described in detail and with reference to specific examples thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
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A magnetic recording medium comprising a non-magnetic support having provided thereon a magnetic layer containing ferromagnetic particles and a binder, wherein said magnetic layer contains at least one compound selected from the group consisting of an ammonium sulfate and an ammonium sulfonate.
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FIELD OF THE INVENTION
This invention relates to methods and materials for improving retention of anchors in wood structures, and, more particularly, relates to such methods and materials for use at the situs of a driven railroad spike into a wood cross tie.
BACKGROUND OF THE INVENTION
The rail industry has historically been plagued by the loosening and loss of rail spikes from wood cross ties, and has periodically undertaken a variety of efforts in response to this documented need for improvement of the spike/tie interface. Spike loss is caused by the lateral and vertical movement of a rail under load (relative to the cross tie, hereinafter referred to jointly as “lateral forces”), which movement creates a ratcheting effect on the rail spike and the tie. This ratcheting eventually results in loosening and, ultimately, dislodgement and loss of the spike and thus further loss of stability of the rail at the tie. Frequent replacement efforts are undertaken to replace lost spikes, the industry standard method involving the steps of driving a wooden plug into the aperture in the tie created by the previously driven and now lost spike, followed be driving of a new spike into the plugged aperture. This means of replacement proves to be at least as unstable and susceptible to spike ratcheting as was the original installation, and thus spike replacement efforts may reoccur several times over the useful life of the tie.
Wood railroad cross ties are treated (typically with creosote) when manufactured to prevent erosion and wood rot. A properly treated tie has a useful life of approximately 25 years depending upon geographical location of tie installation. However, once a spike is driven into a tie, the area that is displaced by the spike becomes exposed to the elements, particularly as the lateral forces described above enlarge the area of displacement. This untreated exposed area around the spike thus captures moisture and microorganisms and is susceptible to freeze and thaw cycles which over time lead to degradation of wood fiber and internal rot around the spike, further weakening the hold between the tie and spike. Industry standard spike replacement methods do little or nothing to address this loss of tie integrity.
This degradation of the tie at and around the site of spike setting in the cross tie also shortens the useful life of the tie leading to premature replacement. Weakened rail ties are hazardous and therefore must be constantly inspected for and attended to. Spike and rail cross tie maintenance and replacement are, therefore, expensive and ongoing undertakings.
Various mechanical means of improving rail spike retention have heretofore been suggested and or utilized (see U.S. Pat. Nos. 2,777,641, 3,865,307, 3,519,205, 3,964,679, 4,203,193, and 5,758,821). Aside from the added expense of such mechanical solutions, many have done little to address the issue of tie degradation around a spike, and have thus met with limited success.
A number of compounds have been heretofore known and/or utilized for improving the strength of an anchor/situs interface (see U.S. Pat. Nos. 4,706,806, 4,723,389, 4,907,917 and 5,397,202). Many of these, however, are not readily adaptable to wood rail cross ties, involve two stage applications and/or require the external application of heat for mixing the compound and thus special tools on site.
Moreover, some such compounds by their nature are harmful to the environment and are thus not used for such wide spread applications as is necessary for railway roadbed maintenance. Some such compounds have also not achieved the longevity of securement of the anchor that is desired and/or have done little to address degradation in and around a spike when set in a wood tie.
In particular, it has been heretofore suggested that a mixture of asphalt and sand be used to improve spike-set life. This combination alone has not proved to be an adequate solution for the problem of improving spike retention and has not found acceptance. Further improvement in this vein could, however, be justified, since affordability and ease of application in the field are potentially achieved by such an approach.
SUMMARY OF THE INVENTION
This invention provides a mixture and method for improving rail spike retention and wood cross tie useful life. The mixture and method are particularly well adapted for use when replacing rail spikes, the mixture being simple to apply at remote locations employing a single stage dry mixture application requiring no special tools, heat generated by driving of the spike effecting amalgamation of mixture components and dispersion in the spike aperture.
The dry mixture includes ground aromatic hydrocarbon material, silica sand, and a hydrocarbon resin adhesive/sealant material. More particularly, the mixture consists essentially of (by weight) between about 50% to 70% sub-angular silica sand having a grade between about 35 mesh and 100 mesh (preferably about 60%), between about 25% to 45% ground petroleum pitch (preferably about 35%), and between about 1% to 10% coumarone-indene resin on silicon dioxide (preferably about 5%).
The method of this invention includes the steps of depositiny the dry mixture into a formed aperture in the tie for receiving the spike and thereafter driving the spike into the aperture so that heat generated by driving the spike effects amalgamation of the mixture and dispersion of the mixture in the aperture. In this fashion the mixture fills and seals wood fibers adjacent to the aperture at the interior of the tie and adhesively and frictionally aids spike retention in the aperture.
The mixture and method may be used for both new installations (by preforming the spike receiving aperture in the tie) and spike replacement in old installations (utilizing the existing aperture formed when the now dislodged spike was driven into the tie).
It is therefore an object of this invention to provide a rail spike retention and tie preserving mixture and method.
It is another object of this invention to provide a rail spike retention and tie preserving mixture and method that are simple to apply at remote locations, requiring no special tools.
It is still another object of this invention to provide a rail spike retention and tie preserving mixture and method that are useful for both new installations (by preforming a spike receiving aperture in the tie) and spike replacement in old installations (utilizing the existing aperture formed when the now dislodged spike was driven into the tie).
It is another object of this invention to provide a rail spike retention and tie preserving mixture and method that employ a single stage dry mixture application, heat generated by driving of the spike effecting amalgamation of mixture components and dispersion in the spike aperture.
It is still another object of this invention to provide a rail spike retention and tie preserving mixture and method wherein heat generated by driving the spike into an aperture in the tie effects amalgamation of the mixture deposited therein and dispersion of the mixture in the aperture thereby filling and sealing wood fibers adjacent to the aperture at the interior of the tie and adhesively and frictionally aiding spike retention in the aperture.
It is yet another object of this invention to provide a dry mixture for application in an aperture in a wood cross tie to improve spike retention and tie preservation thereat, the dry mixture including ground aromatic hydrocarbon material, silica sand, and a hydrocarbon resin adhesive/sealant material.
It is still another object of this invention to provide a dry mixture for improving spike retention and tie preservation consisting essentially of (by weight) between about 50% to 70% sub-angular silica sand having a grade between about 35 mesh and 100 mesh, between about 25% to 45% ground petroleum pitch, and between about 1% to 10% coumarone-indene resin on silicon dioxide.
It is still another object of this invention to provide a dry mixture for improving spike retention and tie preservation including (by weight) about 60% sub-angular silica sand, about 35% ground petroleum pitch, about 5% coumarone-indene resin on silicon dioxide.
It is yet another object of this invention to provide a method for improving rail spike retention in a wood cross tie while protecting the tie from degradation due to environmental exposure of the interior of the tie around the driven spike, the method including the steps of depositing a dry mixture of ground aromatic hydrocarbon material, silica sand, and a hydrocarbon resin adhesive/sealant material into a formed aperture in the tie for receiving the spike, thereafter driving the spike into the aperture, and heat generated by driving of the spike into the aperture in the tie effecting amalgamation of the mixture and dispersion of the mixture in the aperture thereby filling and sealing wood fibers adjacent the aperture at the interior of the tie and adhesively and frictionally aiding spike retention in the aperture.
With these and other objects in view, which will become apparent to one skilled in the art as the description proceeds, this invention resides in the novel construction, combination, arrangement of parts and method substantially as hereinafter described, and more particularly defined by the appended claims, it being understood that changes in the precise embodiment of the herein disclosed invention are meant to be included as come within the scope of the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying FIGURES illustrate a complete embodiment of the invention according to the best mode so far devised for the practical application of the principles thereof, and in which:
FIG. 1 is a photographically based cross-sectional illustration of a prior art tie/spike installation for retaining a rail; and
FIG. 2 is an illustration based on a photograph taken of a cross-section of a wood cross tie (spike removed) having utilized the mixture and method of this invention.
DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a typical rail installation utilizing spike 9 having a shaft 11 and enlarged head 13 . At the time of initial installation, shaft 11 is driven into a wood rail cross tie 15 until head 13 engages flanged base 17 of a typical rail to thus stabilize the rail thereat. Aperture 19 in tie 15 is initially formed when spike 9 is driven into the tie.
Over time, due to spike ratcheting under lateral forces applied by rail traffic, enlargement of aperture 19 occurs (at 21 , 23 and 25 for example) as spike 9 ratchets Dut of aperture 19 (FIG. 1, at A). As this process of dislodgement progresses, the lateral forces continue to enlarge aperture 19 , particularly toward the bottom of the aperture (at 25 ). Even before such enlargement occurs moisture seepage around spike 9 can occur, but this process is accelerated by the enlargement of the aperture. Consequently, wood fibers adjacent to aperture 19 absorb moisture (generally the area at 27 ) accommodated in the enlarged areas and may remain moist for long periods thus promoting microbial growth and resulting degradation of wood fiber (i.e., wood rot). This weakening of wood fiber adjacent to spike 9 leads to further enlargement of aperture 19 , thereby promoting spike dislodgement from tie 15 and premature loss of tie integrity.
To alleviate the problem, when installing spike 9 (either in original installation where the aperture in the tie is preformed, for example by drilling, or, more commonly, in subsequent replacement of a spike dislodged as described above) a dry mixture in accord with this invention is deposited into aperture 19 . The dry mixture of this invention includes ground aromatic hydrocarbon material (preferably ground petroleum pitch), silica sand (preferably sub-angular (sharp edged) silica sand) and a hydrocarbon resin adhesive/sealant typical of the type used in various rubber, adhesive, paint and coating formations to promote adherence and material preservation. Various other known additives may be included (such as antimicrobials, bactericides, wood preservatives or water repellants and the like) in minor proportions.
The petroleum pitch used in the dry mixture is characterized by a softening point below that generated when spike 9 is driven into aperture 19 (typically spike driving generates heat in the spike substantially exceeding 150° F.). A softening point of between about 150° F. and 250° F. is adequate, though a softening point in the lower ranges risks repeated softening of the pitch while in use, a result which is not preferred. The petroleum pitch is further characterized by a density of about 1.230 g/cc at 51.4° F., a coking value of about 52, a flash (COC° C.) of about 312, and low sulfur content. A flake-type petroleum pitch, for example PULVERIZED PETROPITCH 250 produced by Crowley Chemical Company, Inc., is preferred. The petroleum pitch, when softened, promotes amalgamation of the mixture, dispersal throughout the aperture filling wood fibers adjacent thereto, and adherence.
The sub-angular silica sand of the mixture is preferably washed and dried high silicon dioxide content sand, having a mesh grade rating of S-35 to S-100 (S-70 mesh is preferred) characterized by sharp edges that markedly promote frictional retention of spike 9 in tie 15 found lacking heretofore.
The hydrocarbon resin adhesive/sealant material of this mixture is preferably a coumarone-indene resin on silicon dioxide in powder form such as that produced by Natrochem, Inc. (CI-10 DLC -A or CI-25 DLC -A), though a variety of equivalent compounds could be utilized (for example, hydrocarbon based powder materials with adhesive properties such as rosin esters, polyvinyls, butyrals, or combinations thereof). The adhesive/sealant qualities of this material provide significantly enhanced adhesion and waterproofing not found in the prior art.
The proportions of the above-identified components utilized in the mixture of this invention are (by weight) between about 50% to 70% sub-angular silica sand (preferably about 60%), between about 25% to 45% ground petroleum pitch (preferably about 35%), and between about 1% to 10% coumarone-indene resin on silicon dioxide (preferably about 5%). In dry state formulation, initially care is taken to assure relatively even distribution of the components throughout the mixture, dispersal being thereafter maintained in storage without further mixing (i.e., little or no settling of the components in transport and storage has been experienced). The mixture requires no special handling and has a long shelf life.
In the field, the dry mixture is deposited into the vacant aperture 19 , filling the aperture at least half full and preferably filling the aperture to the top of tie 15 . Spike 9 is then driven into aperture 19 . Heat generated by driving the spike softens the ground aromatic hydrocarbon material, effecting amalgamation of the mixture and dispersion thereof throughout the aperture and into the adjacent wood fibers, filling and sealing team (thus protecting tie 15 from degradative forces adjacent to the spike). The improved adhesive content and frictional surfaces provided by the mixture significantly promote better spike retention.
When cooled, the amalgamated mixture sets as a somewhat tacky, unitary structure. As seen in FIG. 2, where a spike set in the mixture in aperture 19 of tie 15 has been removed, aperture 19 remains substantially sealed by the remnants of the amalgamated mixture (generally at 29) clinging to the wood fibers even after spike removal. This is indicative of the adhesive and sealing capabilities of the mixture of this invention, tie 15 remaining protected thereby from environmental degradation even in those cases where dislodgement may occur. The particular test tie shown in FIG. 2, while the spike remained therein, was exposed to extensive surface moisture which, in tests on untreated installations, resulted in significant interior dampening of wood fiber adjacent to the aperture due to seepage around the spike and absorption into the tie thereat. As can be seen from the FIGURE, no discoloration due to moisture seepage and absorption is indicated. Further testing has shown that, under a variety of circumstances and conditions, the mixture of this invention provides a significantly better hold between the spike and the tie than heretofore known dry mixtures and industry standard methods, making spike dislodgement less likely and thereby decreasing spike replacement frequency.
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A rail spike retention and tie preserving mixture and method are disclosed for use in a wood cross tie at the situs of a driven rail spike, the mixture providing a single stage dry mixture application and including ground petroleum pitch, sub-angular silica sand and a hydrocarbon resin adhesive/sealant material. The mixture and method assure better spike retention in the tie while protecting the wood tie from degradation at and around the site of spike placement thus increasing the useful life of the tie.
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TECHNICAL FIELD
[0001] The present invention relates to the use of a laser to process light.
BACKGROUND
[0002] The use of lasers for processing light includes conversion of light from one part of the electromagnetic spectrum to another part of the spectrum. Typically, such processing involves the use of a nonlinear crystal in which an intensive laser beam interacts with an input laser beam, resulting in an output laser beam having a wavelength that is different from the intensive laser beam and the input beam. An example of a system in which such processing is performed is described in European patent published as EP0301803.
[0003] A drawback with such a prior art system is that it is incapable of processing of input light that is incoherent. For example, imaging of spatially extended sources that emit or reflect incoherent light is impossible in such a prior art system.
[0004] Such a prior art system is also not advantageous when a high quality laser beam is desired. In order to produce a high quality beam, the beam can e.g. be spatially filtered through a pinhole or it can be coupled to a single-mode optical fiber. However, both of these schemes lead to a significant loss in power, i.e. they are not energy efficient.
SUMMARY
[0005] In order to improve on prior art solutions there is provided, according to a first aspect, an arrangement for processing incoming incoherent electromagnetic radiation, said incoming incoherent electromagnetic radiation comprising radiation in a first wavelength interval. The arrangement comprises a focusing arrangement for focusing the incoming incoherent electromagnetic radiation, a first cavity configured to comprise an intra cavity laser beam, a nonlinear crystal arranged in the first cavity such that it is capable of receiving the focused incoherent electromagnetic radiation and, in dependence on the spatial overlap between the focused incoherent electromagnetic radiation and the intra-cavity laser beam, by interaction with the intra-cavity laser beam provide processed electromagnetic radiation, said processed electromagnetic radiation comprising radiation in a second wavelength interval.
[0006] In other words, such an arrangement is capable of enabling imaging, e.g. by utilizing a detector that is sensitive in the second wavelength interval, a source of radiation that emits or reflects incoherent light in a first wavelength interval.
[0007] Embodiments include those that comprise a scan unit configured such that it is capable of spatial scanning of incoherent light emanating from an extended light source and conveying the scanned incoherent light to the focusing arrangement.
[0008] Embodiments include those that comprise a single mode fibre probe and a lens for collecting incoherent light from inside an extended light source.
[0009] These are simple ways in which radiation from an extended object can be provided to the nonlinear crystal where the interaction with the intra cavity laser beam takes place.
[0010] The arrangement may be configured such that the first cavity is capable of receiving laser energy from a laser source operating in, e.g., a continuous wave mode or a pulsed mode, outside the first cavity. This configuration provides a possibility to generate a high intracavity field inside the first cavity at all frequencies supported by any laser media. This includes particularly the important class of diode lasers. The technique used is called “frequency locking” of a laser to an external cavity. Frequency locking often involves an electronic stabilization unit. Diode lasers are beneficial since they can be designed for operation at a specific wavelength within in a broad wavelength region. The wavelength flexibility can be used to facilitate a specific transformation between the first and second wavelength range.
[0011] The arrangement may be configured such that the first cavity comprises a lasant medium and a pump source for pumping said lasant medium, the pump source operating in, e.g., a continuous wave mode or a pulsed mode. In this case the lasant medium passively locks itself to the cavity which circumvent any need for active stabilization.
[0012] For example, the lasant medium may be of the type solid state, semiconductor, gas or liquid, and the pumping source may be a flash lamp, semiconductor laser, solid state laser, light emitting diode or current.
[0013] The non-linear crystal may be phase matched to optimize the conversion of incoming electromagnetic radiation in a first wavelength interval to the processed radiation in the second wavelength interval. In order to obtain a good interaction between the incoming radiation and the intra cavity beam to the processed radiation phase matching (PM) or quasi phase matching (QPM) is required. If phase matching or quasi phase matching is not fulfilled, the generation of the processed radiation will essentially cancel due to destructive interference as the incoming radiations propagates through the nonlinear crystal.
[0014] The nonlinear crystal may be configured to be tuned for obtaining phase matching. This can be accomplished using angle tuning of the nonlinear crystal, by applying temperature or pressure to crystal or through quasi phase matching.
[0015] The nonlinear crystal may be configured to be poled for obtaining phase matching. This is method is referred to as quasi phase matching. By (synthetically) changing the direction of the polarization of the dipole moment of the nonlinear crystal periodically, quasi phase matching can be obtained. The periodicity is specific to the interaction at hand. Two nonlinear crystals often used for quasi phase matching is PP KTP and PP LiNbO 3 ,
[0016] The nonlinear crystal may be configured to be poled in a fanned or chirped manner. The fanning implies that the periodicity of the poled crystal is different at different transverse positions in the crystal. Thus by translating the non-linear crystal transversely with respect to the incoming radiation (or vice versa), different wavelength components of the incoming radiation can be quasi phase matched, thus efficiently processed. The poling may also include a chirped structure leading to broad spectral acceptance.
[0017] The nonlinear crystal may be a Brewster cut. This is advantageous since it solves a practical problem that arises from the fact that three different wavelengths are involved, i.e. the wavelength of the incoming radiation, the wavelength of the intra cavity beam and the wavelength of the processed beam. It is difficult and expensive to manufacture dielectric coatings that can act as an antireflexion coating at all three wavelengths. However if the nonlinear crystal is Brewster cut, p-polarized will essentially be transmitted loss-less (or with very low loss), thereby elevating the need for coatings at the end surfaces. When using quasi phase matching all the three mentioned radiation fields can be p-polarized. Thus periodically poled crystals with Brewster cut ends are particularly advantageous.
[0018] The arrangement may be configured such that the interaction between the incoming electromagnetic radiation and the intra cavity beam comprises any one of difference frequency generation, DFG, sum frequency generation, SFG and any combination thereof. SFG and DFG constitute the underlying physical mechanism that allows processing of incoming radiation as described herein.
[0019] That is, the shortest wavelength of the second wavelength interval may be shorter than the shortest wavelength of said first wavelength interval. For example, the first wavelength interval may be an infrared wavelength interval and the second wavelength interval may be a visual wavelength interval, or the first wavelength interval may be a mid infrared wavelength interval and the second wavelength interval may be a near infrared wavelength interval. The longest wavelength of the second wavelength interval may be longer than the longest wavelength of said first wavelength interval. For example, the first wavelength interval may be an ultraviolet wavelength interval and the second wavelength interval may be a visual wavelength interval.
[0020] The first cavity may be a unidirectional ring cavity. In order to optimize the generation of the processed radiation, a very high intensity intra cavity beam is typically needed. The cavity which supports the intra cavity beam often comprises two or more mirrors aligned so as to form a standing wave cavity. A standing wave cavity is characterized by supporting a beam that propagates back and forth forming a standing wave. When a lasant medium is located in the cavity, “spatial hole burning” occurs. Spatial hole burning leads to secondary lasing emission characterized by emitting new wavelengths. Due to a lack of good phase matching of this (or these) new secondary mode(s), the overall efficiency of the SFG or DFG of interaction is reduced. In contrast to a standing wave cavity, the unidirectional ring cavity support a traveling wave which does not lead to standing wave formation and thus spatial hole burning. The unidirectional ring cavity will thus be able to accommodate an intense intra cavity beam leading to high interaction efficiency.
[0021] The first cavity may comprise a frequency selective element for narrowing the bandwidth of the intra cavity beam. This approach also has the purpose of reducing the formation of secondary lasing modes in a standing wave cavity. Typical frequency selective elements are etalons, Lyot filters, gratings and birefringent prism.
[0022] In a second aspect there is provided a method for processing incoming incoherent electromagnetic radiation, said incoming incoherent electromagnetic radiation comprising light in a first wavelength interval. The method comprises focusing the incoming incoherent electromagnetic radiation, maintaining an intra-cavity laser beam in a first cavity, receiving the focused incoherent electromagnetic radiation in a nonlinear crystal arranged in the first cavity and, in dependence on the spatial overlap between the focused incoherent electromagnetic radiation and the intra-cavity laser beam, by interaction with the intra-cavity laser beam providing a processed beam of electromagnetic radiation, said processed beam of electromagnetic radiation comprising radiation in a second wavelength interval.
[0023] As for the first aspect, such a method is capable of enabling imaging, e.g. by utilizing a detector that is sensitive in the second wavelength interval, a source of radiation that emits or reflects incoherent light in a first wavelength interval.
[0024] Use of an arrangement as summarized above in relation to the first aspect is a third aspect that provides large advantages when analyzing a sample from which the incoming light emanates. For example, molecular absorption bands as well as emission bands can be analyzed for gases such as CH 4 , CO, CO 2 , HCl, H 2 S, NH 3 , NO, N 2 O, NO 2 , SO 2 , water vapor, CFC and HFC.
[0025] According to a fourth aspect, an arrangement is provided for processing incoming electromagnetic radiation, said incoming electromagnetic radiation comprising radiation in a first wavelength interval and a plurality of spatial frequencies. The arrangement comprises a focusing arrangement for focusing the incoming electromagnetic radiation, a first cavity configured to comprise an intra cavity laser beam, a nonlinear crystal arranged in the first cavity such that it is capable of receiving the focused electromagnetic radiation and, in dependence on the spatial overlap between the focused electromagnetic radiation and the intra-cavity laser beam, by interaction with the intra-cavity laser beam provide processed electromagnetic radiation, said processed electromagnetic radiation comprising radiation in a second wavelength interval and at least a subset of said plurality of spatial frequencies.
[0026] In other words, such an arrangement is capable of enabling imaging, e.g. by utilizing a detector that is sensitive in the second wavelength interval, a source of radiation that emits in a first wavelength interval and comprising several spatial frequencies. Furthermore, such arrangement is capable of improving the spatial quality of the incoming radiation.
[0027] The arrangement may be configured such that the first cavity is capable of receiving laser energy from a laser source outside the first cavity. This configuration provides a possibility to generate a high intracavity field inside the first cavity at all frequencies supported by any laser media. This includes particularly the important class of diode lasers. The technique used is called “frequency locking” of a laser to an external cavity. Frequency locking often involves an electronic stabilization unit. Diode lasers are beneficial since they can be designed for operation at a specific wavelength within in a broad wavelength region. The wavelength flexibility can be used to facilitate a specific transformation between the first and second wavelength range.
[0028] The arrangement may be configured such that the first cavity comprises a lasant medium and a pump source for pumping said lasant medium. In this case the lasant medium passively locks itself to the cavity which circumvent any need for active stabilization.
[0029] For example, the lasant medium may be of the type solid state, semiconductor, gas or liquid, and the pumping source may be a flash lamp, semiconductor laser, solid state laser, light emitting diode or current.
[0030] The arrangement may be configured to focus and process incoming electromagnetic radiation that comprises any one of coherent radiation, incoherent radiation and a combination of coherent and incoherent radiation. Coherent illumination usual involves a laser or emission from a narrow band light source for illumination of an object. Typical applications of coherent illumination are for holography, speckle inteferometry or confocal microscopy. Incoherent illumination is employing polychomatic light for illumination, e.g. sun light. A typical example is usual pocket cameras that capture light from incoherently illuminated objects.
[0031] The focusing arrangement may be configured to perform an optical Fourier transform of the incoming electromagnetic radiation. Such a configuration will insure that the different spatial frequency components of the incoming radiation are spatially displaced from the optical axis of the system. Thus the higher the spatial frequency of the incoming radiation the more transversely displaced it will be. In consequence the spatial overlap between the intracavity beam and the incoming electromagnetic radiation can be controlled easily.
[0032] The arrangement may be configured such that the transverse dimension of the focused incoming electromagnetic radiation is adjusted relatively to the transverse dimension of the intra cavity laser beam so as to suppress at least a subset of said plurality of spatial frequencies of the incoming electromagnetic radiation. In such a configuration the incoming electromagnetic radiation is effectively low pass filtered. This configuration can be used for removal of unwanted spatial components of the incoming radiation. An example is “beam clean-up”, where essentially only the lowest order spatial component is wanted, i.e. the Gaussian intensity profile.
[0033] The arrangement may be configured such that the transverse dimension of the focused incoming electromagnetic radiation is smaller than the transverse dimension of the intra cavity laser beam so that at least a subset of said plurality of spatial frequencies of the incoming electromagnetic radiation is overlapping the intra cavity beam. In such cases, essentially all the spatial frequencies of the incoming radiation is processed (through sum or frequency generation) and a good upconveted image can be produced.
[0034] The non-linear crystal may be phase matched to optimize the conversion of incoming electromagnetic radiation in a first wavelength interval to the processed radiation in the second wavelength interval. In order to obtain a good interaction between the incoming radiation and the intra cavity beam to the processed radiation phase matching (QM) or quasi phase matching (QPM) is required. If phase matching or quasi phase matching is not fulfilled, the generation of the processed radiation will essentially cancel due to destructive interference as the incoming radiations propagates through the nonlinear crystal.
[0035] The nonlinear crystal may be configured to be tuned for obtaining phase matching. This can be accomplished using angle tuning of the nonlinear crystal, by applying temperature or pressure to crystal or through quasi phase matching.
[0036] The nonlinear crystal may be configured to be poled for obtaining phase matching. This is method is referred to as quasi phase matching. By (synthetically) changing the direction of the polarization of the dipole moment of the nonlinear crystal periodically, quasi phase matching can be obtained. The periodicity is specific to the interaction at hand. Two nonlinear crystals often used for quasi phase matching is PP KTP and PP LiNbO 3 ,
[0037] The nonlinear crystal may be configured to be poled in a fanned manner. The fanning implies that the periodicity of the poled crystal is different at different transverse positions in the crystal. Thus by translating the nonlinear crystal transversely with respect to the incoming radiation, different wavelength components of the incoming radiation can be quasi phase matched, thus efficiently processed.
[0038] The nonlinear crystal may be a Brewster cut. This is advantageous since it solves a practical problem that arises from the fact that three different wavelengths are involved, i.e. the wavelength of the incoming radiation, the wavelength of the intra cavity beam and the wavelength of the processed beam. It is difficult and expensive to manufacture dielectric coatings that can act as an antireflexion coating at all three wavelengths. However if the nonlinear crystal is Brewster cut, p-polarized will essentially be transmitted loss-less (or with very low loss), thereby elevating the need for coatings at the end surfaces. When using quasi phase matching all the three mentioned radiation fields can be p-polarized. Thus periodically poled crystals with Brewster cut ends are particularly advantageous.
[0039] The arrangement may be configured such that the interaction between the incoming electromagnetic radiation and the intra cavity beam comprises any one of difference frequency generation, DFG, sum frequency generation, SFG and any combination thereof. SFG and DFG constitute the underlying physical mechanism that allows processing of incoming radiation as described herein.
[0040] That is, the shortest wavelength of the second wavelength interval may be shorter than the shortest wavelength of said first wavelength interval. For example, the first wavelength interval may be an infrared wavelength interval and the second wavelength interval may be a visual wavelength interval, or the first wavelength interval may be a mid infrared wavelength interval and the second wavelength interval may be a near infrared wavelength interval. The longest wavelength of the second wavelength interval may be longer than the longest wavelength of said first wavelength interval. For example, the first wavelength interval may be an ultraviolet wavelength interval and the second wavelength interval may be a visual wavelength interval.
[0041] The first cavity may be a unidirectional ring cavity. In order to optimize the generation of the processed radiation, a very high intensity intra cavity beam is typically needed. The cavity which supports the intra cavity beam often comprises two or more mirrors aligned so as to form a standing wave cavity. A standing wave cavity is characterized by supporting a beam that propagates back and forth forming a standing wave. When a lasant medium is located in the cavity, “spatial hole burning” occurs. Spatial hole burning leads to secondary lasing emission characterized by emitting new wavelengths. Due to a lack of good phase matching of this (or these) new secondary mode(s), the overall efficiency of the SFG or DFG of interaction is reduced. In contrast to a standing wave cavity, the unidirectional ring cavity support a traveling wave which does not lead to standing wave formation and thus spatial hole burning. The unidirectional ring cavity will thus be able to accommodate an intense intra cavity beam leading to high interaction efficiency.
[0042] The first cavity may comprise a frequency selective element for narrowing the bandwidth of the intra cavity beam. This approach also has the purpose of reducing the formation of secondary lasing modes in a standing wave cavity. Typical frequency selective elements are etalons, Lyot filters, gratings and birefringent prism.
[0043] In a fifth aspect there is provided a method for processing incoming electromagnetic radiation, said incoming electromagnetic radiation comprising light in a first wavelength interval and a plurality of spatial frequencies. The method comprises focusing the incoming electromagnetic radiation, maintaining an intra-cavity laser beam in a first cavity, receiving the focused electromagnetic radiation in a nonlinear crystal arranged in the first cavity and, in dependence on the spatial overlap between the focused electromagnetic radiation and the intra-cavity laser beam, by interaction with the intra-cavity laser beam providing a processed beam of electromagnetic radiation, said processed beam of electromagnetic radiation comprising radiation in a second wavelength interval and at least a subset of said plurality of spatial frequencies.
[0044] As for the fourth aspect, such a method is capable of enabling imaging, e.g. by utilizing a detector that is sensitive in the second wavelength interval, a source of radiation that emits in a first wavelength interval and comprising several spatial frequencies. Furthermore, improving the spatial quality of the incoming radiation is also enabled.
[0045] Use of an arrangement as summarized above in relation to the fourth aspect is a sixth aspect that provides large advantages when analyzing a sample from which the incoming beam of light emanates. For example, molecular absorption bands as well as emission bands can be analyzed for gases such as CH 4 , CO, CO 2 , HCl, H 2 S, NH 3 , NO, N 2 O, NO 2 , SO 2 , water vapor, CFC and HFC.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] Embodiments will now be described with reference to the attached drawings, where:
[0047] FIG. 1 schematically illustrates an optical system,
[0048] FIG. 2 schematically illustrates a first arrangement for processing electromagnetic radiation,
[0049] FIG. 3 a is a photograph of a transmission mask,
[0050] FIG. 3 b is a photograph of an object image,
[0051] FIG. 3 c is a photograph of a processed object image,
[0052] FIGS. 4 a and 4 b are diagrams showing intensity levels of the images in FIG. 3 b and FIG. 3 c , respectively,
[0053] FIG. 5 is a diagram illustrating energy conversion efficiency,
[0054] FIGS. 6 a - d are diagrams showing intensity values for cross-sections of laser beams and corresponding calculated profiles,
[0055] FIG. 7 schematically illustrates a second arrangement for processing electromagnetic radiation,
[0056] FIGS. 8 a - c are diagrams showing intensity values for cross-sections of laser beams,
[0057] FIGS. 9 a and 9 b are diagrams of M 2 measurements,
[0058] FIGS. 10 a - c are diagrams showing intensity values for cross-sections of laser beams,
[0059] FIGS. 11 a - d are photographs intensity distributions of laser beams,
[0060] FIG. 12 is a diagram illustrating energy conversion efficiency,
[0061] FIG. 13 schematically illustrates a third arrangement for processing electromagnetic radiation, and
[0062] FIG. 14 is a diagram illustrating energy conversion efficiency.
DETAILED DESCRIPTION OF EMBODIMENTS
[0063] An efficient way to transform light from one part of the spectrum into a new desired part is by using sum frequency generation (SFG). An apparatus will be described in detail below where two solid state lasers at 1064 nm and 1342 nm respectively are mixed in a PP:KTP crystal located in the intense intra-cavity field of the 1342 nm laser cavity. This resulted in more than 700 mW of SFG, yellow light. In another apparatus, a solid state laser at 1342 nm and a tapered diode laser at 765 nm are mixed to generate more than 300 mW of 488 nm light, corresponding to a power conversion efficiency from 765 nm to 488 nm of 32%.
[0064] It will also be shown that a non-Gaussian tapered diode laser beam can be spatially filtered using SFG with a Gaussian solid state laser beam to produce a SFG beam with nearly Gaussian profile. The filtering characteristics depend on the spatial overlap in the focus plane of the two interacting beams. If the non Gaussian tapered diode beam is focused to a diameter where only its fundamental Gaussian spatial component overlaps the Gaussian beam of the solid state laser, it is possible to obtain an almost Gaussian SFG beam. Similarly if hard focusing is utilized all the detailed spatial features of the tapered diode laser beam will appear in the SFG beam.
[0065] If the input beam in reality is an image, comprising several spatial frequencies, not necessarily a near Gaussian laser beam, it will be described that it is possible, efficiently to transform an image at one wavelength into a new wavelength with high conversion efficiency. The basic principle of imaging conversion by nonlinear conversion is exemplified in the following.
[0066] One interesting feature of the described arrangements and methods is its promise to circumvent an important limitation to already existing mid-IR spectroscopy, namely the lack of efficient mid-IR detector systems. Using the suggested method also mid-IR radiation can conveniently be up-converted to the NIR region for efficient Si-based detection. It is expect that the sensitivity can be increased roughly by a factor of 100 as compared to the best scientific results published, or by 8 orders of magnitude as compared to room temperature systems.
[0067] In the following we will derive an expression for the intensity profile of an up-converted object field, E object =E object (x,y) where x and y denotes the transverse coordinates of the field. The up-converted image, E up =E up (x,y) will be a result of a SFG process between E object and a Gaussian intra-cavity field, U Gauss =U Gauss (U,V), where u and v are the transverse coordinates at the Fourier plane. The specific system under consideration is shown in FIG. 1 . We will assume that the object field is subject to coherent monochromatic illumination [Introduction to Fourier Optics, Joseph W. Goodman, third edition (2005)]. For simplicity we will assume that the system is operated in the non-saturated regime. This assumption implies that the amplitudes of the generating fields, E object and U Gauss can be approximated as being constant throughout the entire interaction length of the nonlinear crystal. Further a plane wave approximation is used and finally that the length of the crystal is short compared to the confocal length. All these assumptions are not necessary, but allow us to derive a simple relation between the light emitted from the object and the corresponding up-converted image at the image plane.
[0068] According to the Fourier optics theory [Introduction to Fourier Optics, Joseph W. Goodman, third edition (2005)], the electric field distribution, U FP at the Fourier plane is given by:
[0000] U FP ( u,v )= jλ 1 fF{E object ( fλ 1 x,fλ 1 y )}
[0000] where:
λ 1 is the wavelength of light emitted from the object,
f is focal length of the Fourier transforming lens,
F is the two dimensional Fourier transform
[0069] The electric field distribution, U Gauss of the intra cavity beam (of wavelength λ 2 ) at the Fourier plane is given by:
[0000]
U
Gauss
(
u
,
v
)
=
U
0
-
u
2
+
v
2
w
0
2
,
U
0
=
4
P
Gauss
π
n
2
ɛ
0
cw
0
2
[0000] where:
P Gauss is the power of the Gaussian electric field,
n 2 is the refractive index corresponding to λ 2 ,
∈ 0 is the vacuum permeability,
c is the speed of light, and
w 0 is the radius at the beam waist
[0070] The nonlinear interaction gives rise to a SFG field, U SFG of wavelength λ 3 at the Fourier plane. U SFG is given by [Introduction to Fourier Optics, Joseph W. Goodman, third edition (2005)]:
[0000]
U
SFG
(
u
,
v
)
=
-
j
2
π
d
eff
L
n
3
λ
3
U
FP
(
u
,
v
)
U
Gauss
(
u
,
v
)
[0000] where:
d eff is the effective nonlinearity of the crystal,
L is the length of the crystal,
λ 1 is the wavelength of the object field,
n 3 is the refractive index corresponding to λ 3 , and
n 1 , n 2 and n 3 are the refractive index corresponding at λ 1 , λ 2 and λ 3 .
λ 3 is determined by:
[0000]
1
λ
3
=
1
λ
1
+
1
λ
2
[0000] where λ 2 is the wavelength of the intra-cavity beam.
[0071] At the image plane the image, E up of U SFG is given by:
[0000]
E
up
(
x
,
y
)
=
-
j
λ
3
f
1
F
{
U
SFG
(
λ
3
f
1
u
,
λ
3
f
1
v
)
}
or
E
up
(
x
,
y
)
=
j
2
π
2
d
eff
L
λ
1
fw
0
2
n
3
f
1
3
λ
3
4
U
0
E
object
(
-
λ
1
f
λ
3
f
1
x
,
-
λ
1
f
λ
3
f
1
y
)
⊗
-
x
2
+
y
2
(
λ
3
f
1
π
w
0
)
2
[0000] where f 1 is the focal length of the Fourier transforming lens.
[0072] For the intensity profile I up :
[0000]
I
up
(
x
,
y
)
=
8
π
3
d
eff
2
f
2
λ
1
2
L
2
w
0
2
n
2
n
3
f
1
6
λ
3
8
P
Gauss
E
object
(
-
λ
1
f
λ
3
f
1
x
,
-
λ
1
f
λ
3
f
1
y
)
⊗
-
x
2
+
y
2
(
λ
3
f
1
π
w
0
)
2
2
[0073] This expression shows that a spatial filtering between the object field and the Gaussian field is taking place. We note that this expression is a generalization of the usual nonlinear theory [Parametric Interaction of Focussed Gaussian Light Beams, G. D. Boyd and D. A. Kleinman, J. of Applied Physics, Vol. 39, no. 8, pg. 3597-3641 (1968)], where Gaussian beams are involved. In the limit where the beam diameter w 0 becomes sufficiently large:
[0000]
I
up
(
x
,
y
)
=
16
π
d
eff
2
f
2
λ
1
2
L
2
n
1
n
2
n
3
c
ɛ
0
f
1
2
λ
3
4
w
0
2
P
Gauss
I
object
(
-
λ
1
f
λ
3
f
1
x
,
-
λ
1
f
λ
3
f
1
y
)
[0074] In this case a perfect up-converted image can be obtained, scaled with a factor:
[0000]
-
λ
3
f
1
λ
1
f
.
[0075] In this If the spatial diameter of E filter , e.g. defined as 1/e 2 level, is much wider than the spatial features of the object, the object E object is effectively low pass filtered. This has been used for beam clean up of a non-Gaussian beam. In the derivation we have for simplicity referred to a specific set-up as shown in FIG. 1 . However, the conclusions remain valid under more general conditions. For example, if an arbitrary number of lenses are arranged to transform the incoherent light source from the object plane to form an image at the image plane, an up-converted image will also be generated even though the non-linear medium is not located at any Fourier plane—provided that the spatial components of the incoming light is essentially within the Gaussian envelope of the intra-cavity beam at the position of the nonlinear crystal (and no depletion of the involved fields takes place). Besides conceptual simplicity of the set-up described in FIG. 1 , a special feature of situating the crystal in the Fourier plane is when filtering is wanted. In the Fourier plane the spatial frequencies of the incoming light is separated the most. Thus providing the best filtering plane. In this derivation we have not included the acceptance parameters of the non-linear process. The angular acceptance parameter of the specific SFG process will act as a filter limiting the resolution for a given set-up. The spectral acceptance parameter defines the spectral width of frequencies that can be up-converted for a specific set-up. Several methods can be used to elevate these limitations. In relation to the derivation above, we note in particularly that under incoherently illumination, our main conclusions remain intact, but emphasize that only light frequencies that fulfills the spectral phase match condition will be efficiently up-converted. Thus, the arrangement described here will act as a spectral filter. Below it will be described a method for scanning said phase match condition, thus the center frequency of the filter.
[0076] A first example of an apparatus in which electromagnetic radiation is processed is shown in FIG. 2 . It comprises a single-frequency 765 nm external-cavity tapered diode laser 201 , a high finesse, Z-shaped 1342 nm solid-state laser 203 that together with mirrors M 1 , M 2 , M 3 and M 3 forms a laser cavity 204 , and an intra-cavity PP:KTP crystal 205 . Characteristics of the 1342 nm laser 203 are described in further detail below with reference to FIG. 7 . The beam waist for the PP:KTP crystal 205 is located approximately 60 mm from mirror, M 2 and the size of the beam waist is 70 μm, ignoring a slight astigmatism arising from the tilted mirrors, M 2 and M 3 as well as from the passage of Brewster cut surfaces of the PP:KTP crystal 205 .
[0077] The intra-cavity power of the 1342 nm laser 203 is measured to be around 120 W when the laser crystal (LC) is pumped with 2 W of 808 nm light from a laser pump 211 .
[0078] The 765 nm tapered diode laser 201 is coupled to a single-mode polarization maintaining fiber 213 . The Gaussian output beam from the fiber 213 is collimated by a lens L 1 (f=100 mm) to a beam diameter of approximately 10 mm. This beam is used for coherent illumination of a transmission mask 215 to form an object beam E object (see FIG. 3 b ). The two slits forming a cross is 1 mm by 5 mm in width. Some minor diffraction effects appear in the transmitted image as can be seen in FIG. 3 b . The 765 nm object is transformed by a lens L 2 with f=100 mm in combination with curved mirror M 2 (f=−50 mm) to the Fourier plane inside the PP:KTP crystal 205 . The PP:KTP crystal 205 is placed at the beam Waist of the 1342 nm cavity 204 .
[0079] The 10 mm long Brewster cut PPKTP crystal 205 is temperature controlled using a Peltier element 217 . The temperature is set to 43.5° C. to facilitate optimum quasi-phase matching for sum frequency generation between the 1342 nm beam and the object beam at 765 nm. Finally the up-converted object beam is collimated by a 200 mm lens L 3 to form the up-converted image 219 at 488 nm.
[0080] FIG. 3 a shows the transmission mask 215 that is coherently illuminated by the 765 nm collimated external cavity laser 201 . The emitted light after passage of the mask 215 , corresponding to E object , is shown in FIG. 3 b . The Fourier transform of the object field E object is performed using a +100 mm lens L 1 placed 80 mm from the object plane and 62 mm from mirror M 2 . Mirror M 2 acts as a negative lens, f=−50 mm due to its radius of curvature. At the position of the beam waist inside the PP:KTP crystal 205 the high intra-cavity field of the 1342 nm laser 203 and the Fourier transformed object field interacts through SFG to generate a blue, 488 nm up-converted image 219 . This is shown in FIG. 3 c.
[0081] FIGS. 4 a and 4 b show the corresponding CCD images, i.e. FIG. 4 a shows the object image corresponding to FIG. 3 b and FIG. 4 b shows the object image corresponding to FIG. 3 c.
[0082] The image at 765 nm ( FIGS. 3 b and 4 a ) contains more noise since the sensitivity of the camera used to record the pictures is far less sensitive to infrared than to visible light. A camera is schematically illustrated by reference numeral 221 . Time of exposure is increased approximately 100 times for the 765 nm recording ( FIGS. 3 b and 4 a ). However it can clearly be seen that the blue upconverted image ( FIGS. 3 c and 4 b ) resembles the original object field ( FIGS. 3 b and 4 a ). The power transmitted through the mask 215 is 15 mW and the blue image contained 6 mW of power. We have thus obtained 40% efficiency in the up-conversion process. To our best knowledge, this is the highest up-conversion efficiency reported. This is illustrated in further detail in a graph in FIG. 5 . FIG. 5 shows discrete experimental results and a fitted linear curve of the 488 nm power as a function of the incident 765 nm power without any transmission mask inserted. As can be seen, the conversion efficiency from 765 nm to 488 nm is indeed 40%. The circulating 1342 nm power was 120 W for all experiments. This experimental situation corresponds to η SUM =0.003 W −1 . A very attractive feature is the linearity between incident and up-converted light which means that also very weak object images can be efficiently up-converted. This is in strong contrast to Second Harmonic Generation (SHG).
[0083] FIGS. 6 a and 6 c show a cross section of the 765 object beam 601 , 609 and the corresponding 488 nm up-converted image 603 , 611 at the image plane. FIGS. 6 b and 6 d show the calculated intensity profiles corresponding to FIGS. 6 a and 6 c respectively. FIG. 6 b shows, the cross section of the 765 nm coherently illuminated object radiation passing the 1 mm wide slit as it appears in the image plane 605 . Using the theory outlined the up-converted 488 nm image at the image plane is shown as 607 . When comparing with the experimentally obtained intensity profiles 601 , 603 a relatively good match is found. FIG. 6 d shows the same features 613 , 615 but corresponding to the 5 mm width of the cross.
[0084] The converted image in FIG. 3 c is not sharp due to different types of distortion. For example, the coupling concave mirror M 2 acts as a negative lens and induces astigmatism in the infrared beam due to angled incidence. Another effect seen in the blue image is the spatial filtering. The 1342 nm beam has a Gaussian profile and attenuates the high-frequency components of the image. The visible image has therefore no sharp edges. Larger 1342 nm beam profile or harder focusing of the infrared image would improve the quality (resolution) of the reproduction. The picture in FIG. 3 c is saturated—in reality it looks better. In addition to this, the visible light is generated throughout the nonlinear crystal and not in the focal plane only. All this contributes to the image distortion as shown in FIG. 3 c.
[0085] The use of Brewster cut nonlinear materials, i.e. crystal 205 , allows for low-loss coupling in and out of the nonlinear material. Furthermore, the different index of refraction at the generated field compared to the fundamental fields allows for the generated beam to bypass the mirrors of the diode pumped solid-state laser (DSSL) resonator in the laser 203 , resulting in a significant reduction in the constraints of the mirror coatings, which could be a problem considering tuning ranges in the mid-IR of more than 1 μm.
[0086] Although the apparatus described above involves the use of electromagnetic radiation in the infrared wavelengths, the apparatus may be used in other wavelength intervals. That is, instead of converting radiation from the IR or MIR to the visible or NIR, it is possible to use the same scheme to convert UV light down to the visible wavelength region, i.e. the region where standard Si detectors have high sensitivity. Typically Si detectors become highly insensitive when the incoming wavelength is below 300 nm. With availability of laser crystals which make possible a high circulating field at around 300-400 nm, UV light can be converted so as to fall in the zone of operation of the Si detectors. To increase the sensitivity of Si detectors to UV light, back-illuminated chips have been developed. These detectors increase tremendously the sensitivity, but demand a relatively expensive technology and still reach only limited spectral bandwidth.
[0087] The converted image may be projected on a conventional Si-based high-speed camera. Thus, the presented technique offers potentially high-speed detector in the MIR region of the spectrum, since the wavelength conversion is practically instantaneous. There is also no need to cool the detector, and there are no moving mechanical parts.
[0088] Now, with regard to improving the quality of a laser beam having a plurality of spatial frequencies, an experimental realization of nonlinear beam clean-up is presented in the following, where the main features of the generated beam are measured as a function of the size and quality of the single-pass 765 nm beam. We generate approximately 300 mW of 488 nm light with a good beam quality of M 2 =1.25 by mixing a high quality beam at 1342 nm with a lower quality beam at 765 nm.
[0089] The apparatus used is similar to the apparatus described above in connection with FIG. 2 , and it is shown in FIG. 7 . The apparatus comprises an external cavity tapered diode laser 701 oscillating at 765 nm and a 1342 nm Nd:YVO4 laser 703 in a Z-shaped high finesse cavity 704 with an intra-cavity periodically poled KTP (PPKTP) crystal 705 for SFG.
[0090] The 1342 nm solid-state laser 703 comprises an 8 mm long a-cut Nd:YVO4 crystal LC with a Nd-doping of 0.5 atm %. The high-finesse cavity 704 is formed by four mirrors: M 1 (plane end surface of the laser crystal), M 2 (r=−100 mm), M 3 (r=−150 mm) and a plane mirror M 4 . M 1 is coated for high reflection at 1342 nm and high transmission at 808 nm. Mirrors M 2 , M 3 and M 4 are coated for high reflection at 1342 nm and high transmission at 765 nm. The distance between M 1 and M 2 is 213 mm, the separation of M 2 and M 3 is 178 mm, and there is 248 mm between M 3 and M 4 . The 1342 nm cavity 704 forms an approximately circular beam waist of 70 μm between mirror M 2 and M 3 inside the Brewster's cut PPKTP crystal 705 . The beam intensity profile measured (using a detector not shown) on the beam leaking through mirror M 4 is nearly Gaussian with an M 2 value very close to unity.
[0091] The intra-cavity losses of the 1342 nm laser 703 are calculated from slope efficiency measurements, using two plane partly reflecting (PR) mirrors (not shown) at the position of M 4 (T=1.35% and T=3.5%). From these measurements, the passive round-trip loss of the 1342 nm cavity is found to be as low as α 1342 P =0.6%.
[0092] A precise measurement of the transmission coefficient of the HR coated mirror M 2 in the used configuration is made by substituting M 4 with a PR mirror (T=1.35%). The 1342 nm leakage through mirror M 2 is then used to calculate the circulating power in the high finesse cavity 704 . Intra-cavity powers of 120 W are measured when the system is pumped with 2 W of 808 nm light when the 765 nm single-pass laser 701 is turned off.
[0093] The tapered diode laser 701 is used in a standard Littrow configuration as shown in FIG. 7 . The rear surface of the AR coated tapered diode TD receives feedback from a reflective grating GR with 1800 lines/mm. This allows for single-frequency operation (sub MHz bandwidth) and tuneable output in a wavelength range of ±6 nm. The maximum output power from the ECDL 701 is 1.3 W at a drive current of 3.1 A. The output from the ECDL 701 is collimated by an aspheric lens AL and a cylindrical lens CL and passed trough a Faraday isolator FI to avoid feedback from the frequency conversion module. Mirrors CM 1 and CM 2 are used for beam alignment and the lens, L, focus the single-pass beam through mirror M 2 into a beam waist inside the nonlinear crystal 705 . Changing the focal length of the lens L from 100 to 300 mm and adjusting the position of the lens L resulted in a beam waist of 63-288 μm inside the PPKTP crystal 705 . The beamquality parameters of the tapered ECDL 701 along the horizontal and vertical axes at the position of the nonlinear crystal 705 are measured to be M 2 H =1.9 and M 2 V =2.4, respectively, at an output power of 1.3 W from the ECDL 701 , corresponding to 1.06 W at the position of the PPKTP crystal 705 , are measured.
[0094] The 10 mm long Brewster cut PPKTP crystal 705 is temperature controlled using a Peltier element 717 . The optimum temperature is found to be 41.5° C. to facilitate optimum phase matching for sum-frequency generation between the 1342 nm and 765 nm beams.
[0095] The focused beam in the PPKTP crystal 705 is the Fourier transform of the ECDL 701 far-field pattern. Thus, low-frequency components are in the centre of the focus, whereas small details are at the perimeter of the beam spot. Passing a focused beam through a pinhole (hard aperture) is a well-known method for filtering of non-Gaussian beams. A similar effect is seen in sum-frequency mixing by proper choice of overlap between the Gaussian beam (soft aperture) in the laser cavity and the incoming non-Gaussian beam. It is possible to suppress the higher spatial frequency components at the perimeter of the Fourier transform of the low-quality beam so that these components do not appear in the mixed beam profile.
[0096] Four different beam waists of the single-pass laser 701 are used to investigate the effect of nonlinear beam clean-up. In the examples to be described below, the focus sizes range from approximately 63 μm to a beam waist four times larger. The smaller the beam waist, the more spatial frequency components in the low-quality beam from the single-pass laser 701 are overlapping with the Gaussian beam of the solid-state laser 703 and thus more of the higher spatial frequencies are transferred to the SFG beam 730 . Using weak focusing of the single-pass beam from the single-pass laser 701 , most of the higher spatial frequency components are outside the Gaussian field of the solid-state laser 703 and hence do not contribute to the nonlinear frequency conversion process. Thus, the SFG output beam 730 consists only of the mixing between the Gaussian intra-cavity beam and the Gaussian part of the low quality single-pass beam resulting in a high quality nearly Gaussian SFG output.
[0097] It is primarily the slow (vertical) axis that is analyzed in the following since this corresponds to the higher M 2 value of the ECDL output, thus emphasizing the nonlinear filtering. The overlap between the nearly Gaussian beam profile of the solid-state laser 703 and the 765 nm laser 701 with different focusing is shown in FIG. 8 .
[0098] In FIGS. 8 a - c the beam profile in the vertical direction of the solid state laser 703 and the 765 nm laser 703 are shown for three different focusing conditions. FIG. 8 a shows the profile 801 in the vertical direction of the solid state laser 703 together with a strongly focused beam 803 from the 765 nm laser 701 . FIG. 8 b shows the profile 805 in the vertical direction of the solid state laser 703 together with a less strongly focused beam 807 from the 765 nm laser 701 . FIG. 8 c shows the profile 809 in the vertical direction of the solid state laser 703 together with a weakly focused beam 811 from the 765 nm laser 701 .
[0099] It is clearly seen from FIG. 8 that the higher spatial frequency components are outside the Gaussian spot when weak focusing is applied. When stronger focusing is used, more and more of the high-frequency components falls within the Gaussian beam profile of the solid-state laser, and the beam quality of the sum-frequency generated beam approaches that of the 765 nm beam. It is, however, not possible to use focusing below 63 μm in the present configuration due to mechanical limitations. In the weak focusing limit, a collimated beam has nearly constant intensity across the area that overlaps with the 1342 nm Gaussian field so that the SFG beam becomes a replica of the 1342 nm beam.
[0100] The effect of the nonlinear beam clean-up is clearly seen from M 2 measurements and from far-field images of the SFG beam 730 , recorded with a suitable detector 721 . The M 2 of the SFG beam 730 , along the horizontal axis and the vertical axis, versus the focus size is shown in FIGS. 9 a and 9 b , respectively. It is seen that the beam quality improves when the focus size increases, moving from a beam quality factor close to that of the single-pass laser at tight focusing toward a beam quality factor of approximately M 2 =1.25 for weak focusing. Along the horizontal axis the beam quality is improved to M 2 =1.28 following a similar trend as observed for the vertical axis.
[0101] The improved beam quality for weaker focusing is also seen from the intensity profile of the generated beam along the vertical direction as seen from FIG. 10 . FIG. 10 a shows the profile of the SFG 488 nm beam 730 corresponding to strong focusing of the beam from the 765 nm laser 701 (cf. FIG. 8 a ). FIGS. 10 b and 10 c show the situations for weaker focusing of the beam from the 765 nm laser 701 (cf. FIGS. 8 b and 8 c ). Note that the measured 488 nm beam 730 is the mirror image of the input beam, as it is passed through an additional lens for analysis.
[0102] As mentioned previously the beam quality of the output from a tapered amplifier laser diode is much higher along the fast axis compared to the slow axis. Using nonlinear beam clean-up separate processing of the fast and slow axis is possible simply by different focusing, corresponding to filtering in one plane using a narrow slit. It is therefore possible to filter only one axis and focus along the other axis to optimize the nonlinear conversion efficiency.
[0103] Also the visible appearance of the SFG output strongly improves when weaker focusing is employed, as seen in the pictures of FIG. 11 . FIG. 11 a shows the far-field intensity distribution of the 765 nm ECDL 701 . Characteristic lines are seen in the 765 nm light corresponding to higher spatial frequencies in the beam. These lines are also seen in the SFG output 730 when tight focusing is applied, as seen in FIG. 11 b . In FIG. 11 c the 765 nm beam waist is increased and the number of higher spatial frequencies is reduced and the beam becomes more Gaussian-like. In FIG. 11 d the beam waist is increased further and the resulting SFG output is very close to a Gaussian beam with M 2 close to unity.
[0104] The conversion efficiency of sum-frequency generation is known to depend strongly on the size of the interacting fields, e.g. the conversion efficiency decreases if the beam size of the injected beam is larger than optimum and the overlap is reduced. This is also evident from FIG. 12 where the generated SFG power is shown as a function of the incoming 765 nm laser power when focused into three different beam waists of 63 μm (reference numeral 1201 ), 136 μm (reference numeral 1203 ) and 288 μm (reference numeral 1205 ), respectively. More than 300 mW of SFG power is obtained using tight focusing in the non-linear crystal, corresponding to a conversion efficiency of 29% from the input 765 nm power to output 488 nm power. At lower 765 nm input power, before depletion of the intra-cavity 1342 nm field, and with better beam quality of the tapered diode laser, the conversion efficiency reaches 42%.
[0105] From FIG. 12 it is clear that the improved beam quality comes at the cost of reduced frequency conversion efficiency. Using a beam waist of 136 μm the SFG output has a significantly improved beam quality and the conversion efficiency still reaches 28% resulting in SFG output power close to 300 mW. Using weaker focusing to obtain a nearly perfect Gaussian output beam the blue output power is reduced to approximately 200 mW corresponding to a 765 to 488 nm conversion efficiency of 19%.
[0106] Comparing with other means of visible light generation in the fundamental Gaussian mode, e.g. by coupling the light from the external cavity tapered diode laser into a single-mode fiber and subsequently perform the frequency conversion process with the filtered output from the single-mode fiber, the nonlinear clean-up scheme shows superior performance. The coupling efficiency from a tapered diode laser, with a beam quality as used here, to a single-mode fiber is relatively low, typically around 50%. The overall conversion efficiency of the approach based on nonlinear filtering is therefore significantly higher than what can be obtained using single-mode fiber filtering. Furthermore the complexity of the nonlinear filtering approach is far less than using fiber coupling.
[0107] Turning now to FIG. 13 , an apparatus will be described that processes incoherent light that emanates from an extended source. For example an object or sample that is illuminated by incoherent light such as sunlight or any ordinary artificial light source.
[0108] The apparatus is similar to the apparatus described above in connection with FIG. 2 and comprises a 1342 nm Nd:YVO4 laser 1303 in a Z-shaped high finesse cavity 1304 with an intra-cavity periodically poled KTP (PPKTP) crystal 1305 for sum frequency generation.
[0109] The 1342 nm solid-state laser 1303 comprises an 8 mm long a-cut Nd:YVO4 crystal LC with a Nd-doping of 0.5 atm %. The high-finesse cavity 1304 is formed by three mirrors: M 1 (plane end surface of the laser crystal), M 2 (r=−100 mm), M 3 (r=−150 mm). M 1 is coated for high reflection at 1342 nm and high transmission at 808 nm. Mirrors M 2 and M 3 are coated for high reflection at 1342 nm and high transmission at 765 nm. The distance between M 1 and M 2 is 213 mm, the separation of M 2 and M 3 is 178 mm. The 1342 nm cavity 1304 forms an approximately circular beam waist of 70 μm between mirror M 2 and M 3 inside the Brewster's cut PPKTP crystal 1305 .
[0110] Lens arrangements 1330 and 1332 are arranged, together with a light scanner 1315 , along a common optical axis 1342 . Incoherent electromagnetic radiation 1338 , emanating from a spatially extended object 1301 , is conveyed by the scanner 1315 to the lens arrangement 1330 and focused inside the PPKTP crystal 1305 in the cavity 1304 . The scanner 1315 is configured such that it outputs scanned incoherent electromagnetic radiation 1340 along the optical axis 1342 . That is, the scanned radiation 1340 is time multiplexed such that, during a specific scan period, the scanner 1315 scans the whole angular extent of the object 1301 and sequentially outputs the scanned incoherent radiation 1340 along the optical axis 1342 .
[0111] Similar to the processing of an object beam, as described above in connection with FIG. 2 , quasi-phase matching for sum frequency generation takes place inside the PPKTP crystal 1305 between the 1342 nm beam from the solid-state laser 1303 and the focused incoherent radiation 1340 . Finally an up-converted object beam 1341 is collimated by the lens arrangement 1332 to a detector 1321 , which is configured to detect at 488 nm. The detector detects the collimated light 1341 at each image point (x,y) scanned by the scanner 1315 and provides it to an image processing and display unit 1350 in which an up-converted image 1352 is obtained.
[0112] A varaiation of this embodiment is to replace the extended object 1301 , the scanner 1315 and the lens with a single mode fibre probe and a lens for collecting light. From LIDAR theory it is known that only light emitted from a small volume around the focus point formed by the fibre tip/lens combination will be efficiently coupled to the fibre. Such an arrangement will allow sampling of a small volume in “mid air” (e.g. inside a burning flame), without probing the intermidiate medium.
[0113] FIG. 14 is a diagram, similar to the diagram in FIG. 5 , illustrating energy conversion efficiency during imaging in an apparatus such as the one illustrated in FIG. 13 . The line 1401 represents Ti:Sapphire and the line 1403 represents a tapered diode.
[0114] Although PPKTP crystals have been used in the examples described above, other crystals can be used, such as Brewster cut PP-LiNbO 3 or PP-LiOTiO 3 crystals. Moreover, the laser sources described above may be operated in any desired mode, continuous wave as well as pulsed.
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Processing of incoherent electromagnetic radiation is described, said incoming incoherent electromagnetic radiation comprising radiation in a first wavelength interval. An arrangement comprises a focusing arrangement for focusing the incoming incoherent electromagnetic radiation, a first cavity configured to comprise an intra cavity laser beam, a nonlinear crystal arranged in the first cavity such that it is capable of receiving the focused incoherent electromagnetic radiation and, in dependence on the spatial overlap between the focused incoherent electromagnetic radiation and the intra-cavity laser beam, by interaction with the intra-cavity laser beam provide processed electromagnetic radiation, said processed electromagnetic radiation comprising radiation in a second wavelength interval. In other words, such an arrangement is capable of enabling imaging, e.g. by utilizing a detector that is sensitive in the second wavelength interval, a source of radiation that emits incoherently in a first wavelength interval.
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FIELD OF THE INVENTION
This application is a continuation of U.S. Ser. No. 10/195,017 filed on Jul. 10, 2002, now U.S. Pat. No. 7,177,606 titled A CONTROL SYSTEM FOR CONTROLLING AN OUTPUT SIGNAL POWER LEVEL OF A WIRELESS TRANSMITTER.
The present invention relates to the field of wireless transmitters. More specifically, the present invention relates to the field of two-way satellite communication systems and other transmission systems where the maximum transmit signal power level is regulated.
BACKGROUND OF THE INVENTION
Two-way satellite communication systems transmit and receive data in various frequency bands. For example, some systems operate in the K a -band, which is between about 17 and 36 GHz. Other systems operate in bands such as the C-band (3.7-6.4 GHz) or the K u -band (11-15 GHz), for example. Future systems may use higher frequencies (e.g., 60 GHz).
Modulation and upconversion are essential methods used in two-way satellite communication systems and in other wireless communication systems. Upconversion is the translation of a signal's frequency from baseband, or the original frequency before modulation, to a higher frequency. The signal is then transmitted at this higher frequency. Upconversion is performed because most antennas can only receive signals that have short wavelengths. Frequency is the inverse of wavelength. Therefore, the higher the frequency a signal has, the shorter its wavelength. Consequently, signals upconverted to a higher frequency are easier to transmit.
Modulation is a method used to transmit and receive data using a carrier signal. Modulated signals can be analog or digital signals. By varying the phase of a digital carrier signal, for example, information can be conveyed. This type of modulation is called phase-shift keying (PSK). There are several schemes that can be used to accomplish PSK. The simplest method uses only two signal phases: 0 degrees and 180 degrees. The digital signal is broken up time wise into individual bits (binary digits-zeros and ones). The state of each bit is determined according to the state of the preceding bit. If the phase of the wave does not change, then the signal state stays the same (low or high). If the phase of the wave changes by 180 degrees—that is, if the phase reverses—then the signal state changes (from low to high, or from high to low). Because there are two possible wave phases, this form of PSK is sometimes called Binary Phase Shift Keying (BPSK).
A more complex form of PSK is called Quadrature Phase Shift Keying (QPSK). QPSK modulation employs four wave phases and allows binary data to be transmitted at a faster rate per phase change than is possible with BPSK modulation. In QPSK modulation, the signal to be transmitted is first separated into two signals: the In-phase (I) signal and the Quadrature (Q) signal. The I and Q signals are orthogonal, or 90 degrees out of phase. Thus, they are totally independent and do not interfere with each other. Each signal can then be phase shifted independently. Both the I and Q signals have two possible phase states. Combining the possible states for the I and Q signals results in four total possible states. Each state can then represent two bits. Thus, twice the information can be conveyed using QPSK modulation instead of BPSK modulation. For this reason, QPSK modulation is used in many two-way satellite communication systems.
Currently, upconversion in most two-way satellite communication systems entails a multi-stage conversion process. First, baseband QPSK I, Q streams arc modulated and then upconverted to an Intermediate Frequency (IF) (e.g., 1.7-2.2 GHz). This conversion is performed by in an Indoor Unit (IDU). The signal is then upconverted again to a transmit frequency, fTx (e.g., 29.5-30.0 GHz), in an Outdoor Unit (ODU) located at the terminal's antenna. The upconversion is then complete and the signal is ready for transmission.
The output signal (transmit signal) of the ODU has associated with it a certain power level. The ODU output signal power level is regulated in many countries and cannot exceed certain levels. The maximum allowable output signal power level varies by country.
In many two-way satellite communication systems, for example, the optimal output signal power level of the ODU is 4 watts. Some countries allow this output signal power level. However, other countries are more limiting in their regulations and allow ODU output signal power levels of no more than 2 watts, for example.
A high ODU output signal power level is preferable to a low ODU output signal power level because the higher output signal power level is easier to detect and receive. A high ODU output signal power level requires a smaller receiving antenna than does a small ODU output signal power level. Small antennas are usually easier and more cost-effective to design and constrict than are large antennas.
The same various limitations on transmitter output signal power levels could be imposed on any transmitting device used in wireless communication systems. Thus, as used hereafter and in the appended claims, the term “two-way satellite communication systems” will be used to refer expansively to all possible two-way satellite communication systems and other applications where the maximum output signal power level of a transmitter is regulated. In addition, the term “ODU” will be used to refer expansively to all possible transmitters.
Thus, there is a need in the art for a method and system of limiting the ODU output signal power level to various levels so that it is always equal to the maximum allowable power level depending on the country within which the two-way satellite communication system operates.
There have been several approaches to complying with the various ODU output signal power level restrictions. One solution is to fix the ODU output signal power level to equal the lowest maximum allowable output signal power level of the countries within which the two-way satellite communication system might operate. For example, if the lowest maximum allowable output signal power level is 2 watts, the ODU amplification circuitry could be modified so that the maximum power level of the output signal never exceeds 2 watts. This ODU output signal power level is obviously not optimal in the countries with higher maximum allowable output signal power levels.
Another traditional solution to limit the ODU output signal power level to various levels is to use Automatic Gain Control (AGC). AGC is a process or means by which the gain (output power versus input power) of the ODU is automatically adjusted as a function of a specified parameter, such as the output signal level. However, AGC cannot be used in the ODU of many two-way satellite communication systems because it takes too long to lock into the desired gain. Also, the ODU output signal power level needs to change according to varying weather conditions. It is currently difficult, if not impossible, for an AGC circuit to adjust for varying weather conditions.
Another possible solution is an IDU that is capable of adjusting the ODU input signal level power. This requires a means for calculating the ODU gain and an interface unit for communicating this gain information to the IDU. The IDU would then need to adjust the ODU input signal power level based on this gain information so that the ODU output signal power level can change to the desired level. However, this process is currently limited by the speed at which the interface unit between the ODU and ODU operates and is therefore too slow for many applications. In addition, it requires an IDU capable of adjusting the input signal level power of the ODU. This capability might not be present in many systems.
Another possible solution that has been explored is to monitor the direct current (DC) current of the output signal of the ODU. Then, according to the monitored DC current, the IDU varies the output signal level which is input into the ODU to adjust the power level of the output signal.
For example, if the power level of the output signal is desired to be less than 2 watts, but it is currently higher than 2 watts, then the DC current of the output signal is higher than it would be at the desired power level. Reducing the ODU input signal power level decreases the ODU output signal power level as well as the DC current of the output signal.
However, in many two-way satellite communication systems, it is difficult to correlate the DC current and the radio frequency (RF) output signal power. This is, in part, due to the use of a class-A wideband power amplifier (PA) in the ODU. Class-A PAs are used because they reproduce the input signal with little distortion. They are, however, the least efficient among the different classes of PAs because the power of their output signals is only a small percentage of the DC power used in the amplification process. The degree of inefficiency varies from PA to PA and thus, the correlation between the DC current of the output signal and its power level is unpredictable.
SUMMARY OF THE INVENTION
In one of many possible embodiments, the present invention provides a control system that controls an output signal power level of a wireless transmitter. The control system preferably includes a detector for detecting the signal power level of the transmitter, an attenuator with variable attenuation levels for selectively attenuating the output signal power level, and a processor for monitoring the output signal power level and comparing the output signal power level, as determined by the detector, to a predetermined threshold. The processor preferably controls the attenuator in accordance with the comparison of the output signal power level and the predetennined threshold.
Another embodiment of the present invention provides a method for controlling an output signal power level of a wireless transmitter. The method preferably comprises selectively controlling the output signal power level of a wireless transmitter in accordance with a comparison of the output signal power level and the predetermined threshold.
Additional advantages and novel features of the invention will be set forth in the description which follows or may be learned by those skilled in the art through reading these materials or practicing the invention. The advantages of the invention may be achieved through the means recited in the attached claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate preferred embodiments of the present invention and are a part of the specification. Together with the following description, the drawings demonstrate and explain the principles of the present invention. The illustrated embodiments are examples of the present invention and do not limit the scope of the invention.
FIG. 1 is a block diagram of a multi-stage modulator and upconverter that is used in an exemplary two-way satellite communication system and that could be used to implement an embodiment of the present invention.
FIG. 2 is a detailed block diagram of ODU components, all or some of which might be used to implement an embodiment of the present invention.
FIG. 3 is a block diagram of a driver circuit that could be used to implement an embodiment of the present invention.
FIG. 4 illustrates a configuration whereby the ODU input and output signal power levels are monitored by a microprocessor and attenuated by a step attenuator such that the output signal power level becomes equal to the maximum allowable power level according to an embodiment of the present invention.
Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides a method and system whereby an ODU produces an output signal with a maximum possible power level that stays within various signal power level restrictions. An IDU capable of adjusting the ODU input signal power level is not necessary under the embodiments of the present invention.
Using the drawings, the preferred embodiments of the present invention will now be explained.
FIG. 1 is a block diagram of a multi-stage modulator and upconverter that is used in an exemplary two-way satellite communication system and that could be used to implement an embodiment of the present invention. As shown in FIG. 1 , baseband QPSK I and Q signals are modulated and upconverted to an intermediate frequency (IF), f IF , in the IDU ( 101 ). The IF, f IF , is within, but not limited to, the L-band range (e.g., 1.7-2.2 GHz). This range is preferable because it is high enough that the ODU ( 100 ) upconversion will allow filtering of the ODU ( 100 ) local oscillator (LO).
The IDU ( 101 ) output signal is then sent to the ODU ( 100 ) via a connecting cable ( 103 ). The connecting cable ( 103 ) can be coaxial cable, for example. The ODU ( 100 ) modulates the signal received from the IDU ( 101 ) and upconverts it to the transmit frequency, f TX . The transmit frequency, f TX , is between 29.5 and 30 GHz in this exemplary system. These frequencies are within the Ka-band. Once the signal has been upconvertcd to the frequency f TX , it is ready for transmission.
As shown in FIG. 1 , the output signal of the ODU ( 100 ) is connected to an antenna ( 102 ). A preferred configuration of the ODU ( 100 ) in two-way satellite communication systems will be explained below in connection with FIG. 2 .
The antenna ( 102 ) can be any of a number of different types of antennas. A preferable antenna in two-way satellite communication systems is a dish antenna ( 102 ), as shown in FIG. 1 . The antenna ( 102 ) transmits the output signal of the ODU ( 100 ).
A more detailed description of the components that make up the ODU ( 100 )—all or some of which might be used to implement an embodiment of the present invention—will be given using the detailed block diagram of FIG. 2 .
As shown in FIG. 2 , the ODU ( 100 ) comprises a Block Up-Converter (BUC) ( 200 ) and a Low Noise Block (LNB) ( 201 ). The BUC ( 200 ) performs upconversion of a signal to be transmitted. The LNB ( 201 ), on the other hand, receives a signal transmitted from a satellite, for example, and down converts the signal (reduces its frequency) so that the received signal can be demodulated and its data extracted. The LNB ( 201 ) down converts the received signal because the detection circuitry (not shown) is preferably designed for lower frequencies and cannot operate with signals of frequencies in the GHz range.
For example, in many two-way satellite communication systems, the LNB ( 201 ) receives a signal of frequency f RX in the range of 19.7 GHz to 20.2 GHz as shown in FIG. 2 . The LNB ( 201 ) down converts this signal to a frequency in the range of 950 MHz to 1450 MHz. The signal is then demodulated and down converted to baseband by the detection circuitry (not shown) where the data can be extracted from the signal.
The key components of the BUC ( 200 ), shown in FIG. 2 , will now be explained.
An input signal with frequency f IF enters the BUC ( 200 ) and is input into a driver circuit ( 202 ). The driver circuit ( 202 ) is shown in more detail in FIG. 3 . As shown in FIG. 3 , the driver circuit ( 202 ) consists of a series of amplifiers ( 300 ) and thermopads ( 301 ). The amplifiers ( 300 ) amplify the input signal. The thermopads ( 301 ) compensate for changing temperature and keep the power output stable over temperature. The theremopads ( 301 ) provide power attenuation that varies with temperature, thus reducing the variations in the power of the signal.
Returning to FIG. 2 , the signal output from the driver circuit ( 202 ) is then filtered with a filter ( 203 ) to remove the possible interference present at unwanted frequencies that would alias down and interfere with the desired signal during the detection process.
The filtered signal is then mixed with a signal of frequency 3*f DRO (where * denotes multiplication) using an analog mixer ( 204 ). This signal is derived from the Dielectric Resonance Oscillator Phase Lock Loop (DRO PLL) ( 208 ). The DRO PLL ( 208 ) will be explained in more detail below.
Using common trigonometric identities, it can be shown that the signal output from the analog mixer ( 204 ) has a frequency f TX equal to 3*f DRO −f IF , where f DRO is the frequency of the output signal of the DRO PLL ( 208 ). In many two-way satellite communication systems, f TX is in the range of 29.5 GHz to 30 GHz, as shown in FIG. 2 .
The analog mixer ( 204 ) output signal is then filtered with another filter ( 205 ) before being amplified with a power amplifier (PA) ( 206 ) designed to amplify the signal to the optimal output power level (e.g., 4 watts). After being amplified by the PA ( 206 ), the signal is fed into an antenna ( 102 ; FIG. 1 ) preferably via a waveguide connector ( 104 ; FIG. 1 ). The antenna ( 102 ; FIG. 1 ) then transmits the signal.
As shown in FIG. 2 , a single DRO PLL ( 208 ) is preferably used to implement the present invention. A reference signal of frequency f REF is generated in the EU ( 101 ; FIG. 1 ) and sent to the ODU ( 100 ; FIG. 1 ). Inside the ODU ( 100 ; FIG. 1 ), a band pass filter ( 209 ) removes noise around this signal. The signal is then input into the DRO PLL ( 208 ) as its reference signal. The DRO PLL ( 208 ) generates a phase-locked signal (e.g., a sine wave) of frequency f DRO . Different harmonics of this signal can be mixed with the transmit IF signal and the receive signal to obtain the desired output signals.
For example, in many two-way satellite communication systems, f REF is 10.575 MHz. The output of the DRO PLL ( 208 ) is a phase-locked signal with f DRO equal to 10.575 MHz. The third hannonic of this signal is obtained by multiplying the signal by 3 using a multiplier ( 207 ). This signal is then mixed with the output of the first BUC ( 200 ) filter ( 203 ), as explained above, with an analog mixer ( 204 ) resulting in a signal of frequency f TX equal to 29.5 GHz to 30 GHz.
In the LNB ( 201 ), on the other hand, the second harmonic of the output signal of the DRO PLL ( 208 ) is used to down convert the received signal from the antenna ( 102 ; FIG. 1 ) to a frequency of 950 MHz to 1450 MHz. The second harmonic is obtained by multiplying the output signal of the DRO PLL ( 208 ) by 2 using another multiplier ( 210 ). This signal is then mixed with the received signal from the antenna ( 102 ; FIG. 1 ) using another analog mixer ( 211 ).
As shown in FIG. 2 , a microprocessor ( 212 ) is preferably used to monitor several status signals of the ODU ( 100 ; FIG. 1 ). Examples of signals to be monitored include the PLL Lock status output from the DRO PLL ( 208 ), Low DC Voltage status, and the ODU Controller status. The PLL, Lock status indicates whether or not the output signal of the DRO PLL ( 208 ) is locked in phase. The low DC Voltage status monitors the DC voltage to make sure it is high enough for proper ODU ( 100 ; FIG. 1 ) operation. The ODU Controller status indicates the health of the ODU ( 100 ; FIG. 1 ) control electronics. If one of these status signals indicates an error in the ODU ( 100 ; FIG. 1 ), the microprocessor ( 212 ) outputs a signal, TX Mute, that stops the ODU ( 100 ; FIG. 1 ) from transmitting by adjusting a bias ( 214 ) that mutes the PA ( 206 ).
The ODU ( 100 ; FIG. 1 ) communicates the status signals to the IDU ( 101 ; FIG. 1 ) so that the IDU ( 101 ; FIG. 1 ) circuitry can attempt to rectify the problem. This communication is accomplished via a Digital Satellite Equipment Control (DiSEqC) ( 213 ). An exemplary DiSEqC ( 213 ) operates at 22 kHz and uses pulse width keying (PWK). DiSEqC ( 213 ) messages are sent as sequences of short bursts of 22 kHz tones. Each bit of data occupies a specific time and the proportion of that time filled with the 22 kHz burst determines whether that bit is a 1 or a 0.
FIG. 4 illustrates an embodiment of the present invention. The embodiment entails a method and system whereby the input signal power level and the output signal power level of the ODU ( 100 ; FIG. 1 ) are monitored by the microprocessor ( 212 ) and can be attenuated by a step attenuator ( 402 ) such that the output signal power level becomes equal to the maximum allowable power level. The embodiment will be explained in more detail below.
As shown in FIG. 4 , the input and output signals of the ODU ( 100 ; FIG. 1 ) are coupled to detectors ( 400 a,b ). A preferable detector ( 400 a,b ) outputs a root-mean-square (rms) DC voltage that is equivalent to the detected signal power level. The detector ( 400 a,b ) can be a circuit comprising discrete components such as diodes, resistors, capacitors, and an operational amplifier. The detector can also be an integrated circuit (IC) chip, such as the AD8361 detector made by Analog Devices™.
After the detectors ( 400 a,b ), analog to digital converters (A/Ds) ( 401 a,b ) digitize the output signals of the detectors ( 400 a,b ), as shown in FIG. 4 . Digitization is performed because preferable microprocessors ( 212 ) function with digital signal inputs. The A/D ( 401 a,b ) outputs are then input into the microprocessor ( 212 ). Some microprocessors ( 212 ) have built in A/Ds and in this case, the external A/Ds would no longer be needed.
The microprocessor ( 212 ) compares the digitized ODU ( 100 ; FIG. 1 ) output signal power level to a preset threshold. This preset threshold is preferably equivalent to the maximum allowable output signal power level. The threshold is programmable and can be varied.
If the ODU ( 100 ; FIG. 1 ) output signal power level is above the threshold, the microprocessor ( 212 ) switches in a step attenuator ( 402 ) with a control signal, ATT. The control signal, ATT, preferably indicates to the step attenuator ( 402 ) the amount of attenuation necessary for the ODU ( 100 ; FIG. 1 ) output power signal level to equal the threshold level.
The step attenuator ( 402 ) can be an IC or a circuit consisting of discrete components, for example. An exemplary step attenuator ( 402 ) has an attenuation range of 15 dB with a 0.5 dB step resolution. The attenuation range and step resolution can vary depending on the specifications of the application.
The step attenuator ( 402 ) attenuates the ODU ( 100 ; FIG. 1 ) input signal by the amount specified by the control signal, ATT. This results in the attenuation of the ODU ( 100 ; FIG. 1 ) output signal. This method and system of signal power attenuation attenuates the ODU ( 100 ; FIG. 1 ) output signal power level without terminating the ODU ( 100 ; FIG. 1 ) output signal. It is also faster than previous methods of attenuation where communication with the IDU ( 101 ; FIG. 1 ) is required because the use of a DiSEqC ( 213 ), which currently operates at relatively slow rates (e.g., 22 khz), is not needed to attenuate the ODU ( 100 ; FIG. 1 ) output signal power level.
In a preferred embodiment, the settings of the step attenuator ( 402 ) are sent to the IDU ( 101 ; FIG. 1 ) through the DiSEqC ( 213 ), as shown in FIG. 4 , so that the IDU ( 101 ; FIG. 1 ) does not continue increasing the signal level at the ODU ( 100 ; FIG. 1 ) input if the ODU ( 100 ; FIG. 1 ) output signal power level exceeds the threshold.
As previously explained, the ODU ( 100 ; FIG. 1 ) input signal power level is also monitored by the microprocessor ( 212 ). The ODU ( 100 ; FIG. 1 ) input signal power level is monitored for a variety of purposes including ODU ( 100 ; FIG. 1 ) fault detection, fault isolation, and initial gain setting at the IDU ( 101 ; FIG. 1 ).
If the ODU ( 100 ; FIG. 1 ) output signal power level is still over the threshold level after the step attenuator ( 402 ) is set to its maximum attenuation level, the microprocessor ( 212 ) can preferably generate the signal, TX Mute, which mutes the ODU ( 100 ; FIG. 1 ) output signal using the bias ( 214 ) as explained previously.
The preceding description has been presented only to illustrate and describe the invention. It is not intended to be exhaustive or to limit the invention to any precise form disclosed. Many modifications and variations are possible in light of the above teaching.
The preferred embodiment was chosen and described in order to best explain the principles of the invention and its practical application. The preceding description is intended to enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims.
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A method and system for controlling an output signal power level of a wireless transmitter can be created by detecting the signal power level of the transmitter with a detector, selectively attenuating the output signal power level with an attenuator having variable attenuation levels, and monitoring the output signal power level and comparing the output signal power level, as determined by the detector, to a predetermined threshold with a processor. The processor preferably controls the attenuator in accordance with the comparison of the output signal power level and the predetermined threshold.
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This is a division of application Ser. No. 441,811, filed Feb. 12, 1974, now U.S. Pat. No. 3,905,738, issued Sept. 16, 1975.
BACKGROUND AND SUMMARY OF THE INVENTION
When articles are made of plastic on blow molding machines, the plastic is substantially stronger if the plastic material has been stretched in two directions at right angles to one another. This results in "bi-axial orientation". With some plastics bi-axial orientation is necessary in order to obtain a clear transparent article. With other materials the bi-axial orientation substantially increases the strength of the final product even though no clear transparency can be obtained.
This invention provides improved apparatus and method for making bi-axially oriented products by blow molding. In order to obtain more flexibility in handling the parison on the core rod, this invention uses a core rod which is covered with an elastic balloon. This balloon hugs the core rod when the balloon is deflated and the parison is applied over the surface of the balloon in the injection mold.
The core rod is transferred from the injection mold to a conditioning station where the plastic of the parison is brought to orientation temperature; that is, the temperature at which solidification begins. The parison is then stretched in the direction of its length by increasing the length of the core rod and stretching the balloon lengthwise of the core rod with the plastic material coated over the balloon.
This stretching operation is performed in a mold with special provision for permitting movement of the plastic in the mold lengthwise of the core rod and with no contact, or only light contact, between the plastic and the mold surfaces.
Following this initial stretching, the core rod and parison are moved to a second conditioning station and then to a blowing mold in which the parison is preferably blown to its final shape.
Other objects, features and advantages of the invention will appear or be pointed out as the description proceeds.
BRIEF DESCRIPTION OF DRAWING
In the drawing, forming a part hereof, in which like reference characters indicate corresponding parts in all the views:
FIG. 1 is a diagrammatic top plan view of blow molding apparatus for obtaining bi-axial orientation in accordance with this invention;
FIG. 2 is a greatly enlarged sectional view through the mold in which the parison is stretched to provide orientation in one axis; and
FIG. 3 is a fragmentary, enlarged, sectional view taken on the line 3--3 of FIG. 2.
DESCRIPTION OF PREFERRED EMBODIMENT
FIG. 1 shows a blow molding machine 10 which has five stations. The first station is an injection station 12 in which plastic is injected into a mold cavity to apply a parison to core rods 14 which extend from an indexing head 16 that supports the core rods. The core rods 14 are supported from the indexing head 16 in the usual manner.
After the injection step, the injection mold 12 opens and the indexing head moves the core rods to a second station which is a conditioning station 18 which is located at an angle of 72° , around the axis of rotation of the indexing head, with respect to the injection station 12.
The apparatus shown in FIG. 1 being a five position machine, each station is located at an angle of 72° with respect to each adjacent station and the indexing head 16 moves through an angle of 72° each time the core rods 14 are to be shifted from one station to the next.
At the conditioning station 18, there are means for bringing the parison to its orientation temperature by use of fluid from temperature control apparatus 20. The construction of the conditioning station 18 and its temperature control means 20 can be conventional and no further illustration of it is necessary for a complete understanding of this invention. The temperature to which molten plastic must be brought in order to obtain orientation by stretching of the plastic is well known and while it differs from one plastic to another, it is always the temperature at which the molten material begins to solidify.
With the next angular movement of the indexing head 16, the core rods are moved from the first conditioning station 18 to a second conditioning station 24 which includes a mold 26 and temperature control means 28. The construction and operation of this second conditioning station is the principal concern of the present invention and it will be described in more detail in connection with FIGS. 2 and 3. For the present it is sufficient to understand that the parison is stretched lengthwise of the core rod, while maintained at orientation temperature, in the mold 26 at the second conditioning station 24.
The core rods are moved next to a blowing station 30 having a mold in which the parison is blown, preferably to its final contour, while its temperature is maintained at approximately the orientation temperature by temperature control means 32.
Beyond the blowing station, the core rods are transferred to a stripper station 34 at which blown articles are stripped from the core rod in a conventional manner.
FIG. 2 shows a core rod 14 which has a shoulder 38 at one end for connecting the core rod to the indexing head 16 by screws 40 which tread into the face of the indexing head 16. These screws 14 also hold a hub 42 securely connected to the indexing head 16. This hub 42 extends around the neck end of the core rod 14.
The core rod is hollow but not of uniform inside diameter. For a portion of the length of the core rod there is a tube 44 which is concentric with the longitudinal axis of the interior of the core rod and this tube 44 has an outside diameter substantially less than the inside diameter of the core rod along most of the length of the tube 44 within the core rod. There is provided, therefore, an annular chamber 46 between the outside surface of the tube 44 and the inside surface of the core rod for a substantial portion of the core rod length, including all of the right hand or neck portion of the core rod in FIG. 2. Near the right hand end of the tube 42 there is a shoulder 48 at which the interior diameter of the core rod decreases to a bore 50 which has an inside diameter substantially equal to the outside diameter of the tube 44. The end of the tube 44 extends into this bore 50 with a press fit or other rigid connection of the tube 44 with the core rod 14.
Beyond the end of the tube 44 there is a chamber 52 within the core rod 14 and this chamber 52 has passages 54 opening through its side walls for flow of fluid from the chamber 52 into an annular space 56 between the outside surface of the core rod 14 and an inside surface of an elastic balloon 58 which covers the core rod. A plastic parison 60 coats the outside of the balloon 58.
When the core rod 14 is in the injection mold, the balloon 58 is fully deflated and hugs the outside surface of the core rod 14. The parison 60 is applied to the balloon 58 while the balloon is hugging the core rod and the initial expansion of the balloon to form the annular space 56 is obtained by a slight initial blowing of the balloon in the first conditioning station 18.
The purpose of this initial blowing is to permit the circulation of temperature controlling fluid along the inside surface of the balloon 58 for temperature control of the parison 60 but this is the subject matter of another patent application and it is mentioned here merely for the purpose of answering the question as to where the annular space 56 was first produced.
The chamber 52 does not extend all the way to the end of the core rod but the passages 54 are spaced along the length of the core rod for a substantial distance beyond the chamber 52 and these additional passages 54 are supplied with fluid from the chamber 52 through headers 62.
Temperature controlling fluid, for obtaining the necessary orientation temperature of the parison 60, is circulated in contact with the inside surface of the balloon 58. This circulation is obtained by passing the fluid, preferably liquid, through the tube 44 into the chamber 52 and from the chamber 52 through the passages 54 into the annular space 56 at various locations corresponding to the passages 54 which are spaced not only longitudinally along the length of the core rod but also axially around the circumference of the core rod. The fluid discharged into the space 56 from the passages 54 flows lengthwise of the space 56, toward the left in FIG. 2, and exhausts from the annular space 56 through inlet passages 64 leading from the annular space 56 through the wall of the core rod and into the annular space 46 within which the fluid flows toward the left and into an appropriate exhaust passage in the indexing head 16.
The next portion 56 has its end bonded to the hub 42; and in the construction illustrated, the parison 60 is applied over a part of the hub 42 beyond the balloon 58.
At the free end of the core rod 14, that is, the end remote from the indexing head 16, there is a longitudinal bore 68 and there is a core rod extension element 70 which has a stem portion that slides in the bore 68 like a piston in a cylinder. This core rod extension element 70 has a rounded head 72 and a threaded portion 74 adjacent to the rounded head 72 with a nut 76 that screws over the threads 74 to a clamp a washer 78 against the portion of the balloon 58 that contacts with the under side of the rounded head 72. This construction is shown most clearly in FIG. 3 which is on a slightly larger scale than FIG. 2. The parison 60 is omitted in FIG. 3 for clearer illustration.
The end of the balloon 58, remote from its neck portion, has an opening 80 through which the core rod extension element 70 extends. Around the edges of the opening 80, the balloon has a lip 81 which fits into a complementary recess in the back surface of the rouned head 72. The lip 81 is clamped into this recess by the washer 78 when the nut 76 is screwed up against the washer 78.
The pressure of the fluid in the annular space 56 tends to expand the balloon 58 and parison 60 to a larger diameter and also tends to increase the length of the balloon since the core rod extension element 70 can move longitudinally with respect to the otherwise fixed part of the core rod. The fluid pressure within the chamber 52, however, is substantially higher than that in the annular space 56 because of the pressure drop through the passages 54. To provide greater force for stressing the balloon 58 and parison 60, there is a communication passage 84 between the chamber 52 and the left hand end of the bore 68. Pressure exerted through this passage 84, against the end of the core rod extension element 70 pushes the extension element 70 toward the right in the bore 68 with a cylinder-and-piston action to move the core rod extension element 70 toward the right in FIG. 2, as indicated by the dotted line position, and thereby stretch the parison 60.
This stretching of the balloon and parison takes place in a mold having an upper section 86 and a lower section 88 which move toward and from one another in accordance with conventional practice. When the mold parts 86 and 88 are in contact with one another; that is, the mold is closed, they form a mold cavity 90 which is slightly larger in diameter than the parison 60 when the parison is introduced into the mold cavity 90. The cavity 90, however, is substantially longer than the parison 60, as will be evident from FIG. 2. The parison can expand only slightly in the cavity 90 without coming in contact with the walls of the cavity; but the parison 60 can be stretched for a substantial distance, as indicated by the dot and dash lines in FIG. 2.
There is a plunger 92 which extends through an opening in the end of the cavity 90 and the end face of this plunger 92 is shaped to produce the desired set or contour for the parison 60 at the end of the stretching operation. The balloon 58 tends to expand beyond the rounded head 72 as the result of pressure within the balloon, but the rounded head 72 restrains this expansion.
It is essential, however, to prevent the core rod extension element 70 from moving all the way into contact with the end of the cavity 90; that is, with contact with the end face of the plunger 92.
In order to limit the stroke of the core rod extension element 70, there is a pin 94 extending through a fixed portion of the core rod 14 and through a slot 96, best shown in FIG. 3, in the stem or piston portion of the core rod extension element 70.
In addition to the control of the temperature of the parison 60 by circulating temperature controlling fluid through the annular space 56 within the balloon 58, the apparatus as shown in the drawing also circulates cooling fluid through the clearance between the outside surface of the parison 60 and the inside surface of the cavity 90. FIG. 2 shows temperature control apparatus 28 diagrammatically and in position to deliver the temperature controlling fluid through a passage 98 in the upper mold section 86. There are exhaust passages 100 and 102 at the other end of the cavity 90 for the flow of temperature controlling fluid from the cavity 90 through passages indicated diagrammatically by the reference character 104 and these passages preferably lead to self-releasing regulators, that is, regulators that permit pressure to build up to a certain value and then reduce the pressure in accordance with the adjustment of the regulators.
The circulation of the pressure controlling fluid from the passage 98 to the exhaust passages 100 and 102 also serve another purpose. The pressure of this fluid in the clearance between the parison 60 and the surface of the cavity 90 tends to limit the expansion of the parison 60 in a radial direction. The pressure of this fluid is correlated with the pressure within the balloon 58 so that the plastic of the parison 60 will not be expanded into firm contact with the surface of the mold cavity 90 until the parison has been stretched to the desired extent for providing axial orientation in a longitudinal direction. It will be evident that if the parison 60 were pressed into firm contact with the mold cavity 90 before the parison had been stretched, then friction of the parison against the surface of the cavity 90 would reduce the amount of stretching of the plastic near the outside surface of the parison while that on the inside surface would stretch more easily and the orientation of the parison would not be uniform.
The plunger 92 slides in a bearing 110 carried by a fixed frame 112. The plunger 92 is connected with a piston rod 114 which threads into the plunger and is held by a lock nut 116. This piston rod 114 extends from a cylinder 118 which is representative of means for moving the plunger 92 in and out with respect to the mold cavity as desired. Other plungers 92 can be substituted for that shown depending upon the desired contour of the end of the parison when it leaves the mold cavity 90 and the plunger 92 is also shaped so that it stretches the portion of the parison which extends across the end of the core rod and thereby provides orientation of the end of the parison as well as its side walls. The cylinder 118 moves the plunger 92 as necessary to provide stretch of the end plastic of the parison comparable to that provided by the lengthening of the core rod.
The preferred embodiment of the invention has been illustrated and described, but changes and modifications can be made and some features can be used in different combinations without departing from the invention as defined in the claims.
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This injection blow molding machine has special provision for maintaining the plastic of a parison on a core rod at the orientation temperature of the plastic; and stretching the plastic of the parison lengthwise of the core rod for orientation in the direction of one axis without any substantial increase in the diameter of the parison. After this orientation in one axis, the temperature is controlled to maintain an orientation temperature, and the plastic of the parison is then blown to a larger diameter so as to obtain orientation in another axis for "bi-axial orientation". The core rod is covered by an elastic balloon, and provision is made for obtaining flow of the plastic on the core rod lengthwise of the rod during the first orientation operation.
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[0001] The present disclosure relates generally to injecting liquid into the stem or trunk of a tree, and more particularly, this disclosure relates to injecting liquid such as a pesticides, growth regulators or nutrient and/or fertilizers into the sapwood of a tree trunk.
[0002] Arborists may inject liquids, such as insecticides, fungicides, growth regulators, nutrients and/or fertilizers, into the sapwood of tree trunks in an effort to maintain or improve the health of the trees. For example and in one of the known methods, a borehole is formed into the sapwood, thereafter the outer end of the borehole is closed by fixedly mounting a plug in the outer end of the borehole, and thereafter a needle of an injector is inserted through a septum of the plug so that the tip of the needle projects farther into the borehole than the plug. Then, the injector may discharge liquid into the borehole by way of the portion of the needle that projects farther into the borehole than the plug. The needle may be withdrawn from the plug, and the plug's septum may seal the plug so that the injected liquid is contained in the inner portion of the borehole until the injected liquid is drawn upwardly in the sapwood of the tree. Alternatively, a needless injector used with a plug having a check valve is employed. In either case, the plug may optionally remain installed in the tree trunk for subsequent treatments by way of the plug.
[0003] For example, published PCT application WO2012114197 entitled “Tree Injection Apparatus and Methods” discloses an injector and an associated liquid supply assembly that includes a T-joint mounted between a barrel, a dosing assembly, a trigger assembly and a manifold assembly from which a supply of formulation for injection is provided from containers once they are pressurized.
[0004] Notwithstanding, the above-described tree injection equipment may be considered to be labor intensive and time consuming, such as when the tree injection formulation is decanted from a bulk product container into the tree injection equipment or potentially less hygienic when such equipment requires the use of pressurized product containers. Accordingly, there is a desire for tree injection system, apparatus and methods that provide a new balance of properties for enhanced tree management.
SUMMARY OF THE INVENTION
[0005] The following presents a simplified summary of this disclosure in order to provide a basic understanding of some aspects of this disclosure. This summary is not an extensive overview of the disclosure and is not intended to identify key or critical elements of the invention or to delineate the scope of the invention. The purpose of this section is to present some concepts of the disclosure in a simplified form as a prelude to the more detailed description that is presented later.
[0006] There is provided by the present invention an injection system for use in injecting a liquid into a tree, the system comprising: (A) a liquid supply assembly comprising a liquid supply inlet for providing the liquid to the assembly at ambient pressure, an electric pump for pressurizing and discharging the liquid from the assembly at a first pressure above ambient pressure through a liquid supply outlet, a pressure switch connected to the supply outlet and in electrical communication with the pump for selectively actuating the pump when the pressure of the liquid supply outlet falls below said first pressure.
[0007] The inventive system further comprises (B) an injection gun comprising an injector inlet in fluid communication with the liquid supply assembly (A) for receiving the liquid from the liquid supply assembly at said first pressure; an injector outlet for discharging the liquid from the injector assembly; a trigger assembly being in fluid communication with the injector inlet and the injector outlet and movable from a first position to a second position; and (C) a liquid dosage assembly for providing a metered dose of the liquid to the tree.
[0008] Advantageously, the dosage assembly (C) works cooperatively with the liquid supply system (A) and, in particular, with the pressure switch that is associated with the liquid supply system. The dosage assembly (C) comprises a first chamber for alternately being in fluid communication with the injector inlet and the injector outlet; and a second chamber that contains a gas under a second pressure above ambient pressure which is lower than said first pressure when the system is in operation. The second chamber is cooperatively associated with the first chamber such that it biases the first chamber via a piston or diaphragm arrangement when the trigger is moved from a first position, where the first chamber is in fluid communication with the injector inlet, to a second position where the first chamber is in fluid communication with the injector outlet. During operation, the respective volumes of the first and second chambers change in inverse proportion to one another both when the liquid in the first chamber is discharged through the injector outlet and also when the first chamber is re-filled with liquid received from the liquid supply assembly via the injector inlet. In this regard, the first chamber is for alternately receiving the a metered dose of the liquid from the injector inlet at said first pressure when the trigger is in the first position, and providing the metered dose of the liquid to the outlet at said second pressure when the trigger is in said second position.
[0009] Once triggered, a metered dose is injected into to the tree through the discharge nozzle at the tip of the injection gun when it is engaged with an appropriate borehole having an optional plug. A subsequent metered dose is received in to gun from the liquid supply system when the trigger returns to a starting position when a pressure differential is detected by the pressure switch and thereby selectively actuating the pump to retrieve liquid from an unpressurized supply container. The inventive system can be used with any number of known injection protocols such as, for example, those disclosed in published PCT applications WO/2012/114197 or WO/2013/149993 which are incorporated by reference herein. Suitable protocols can be those which use an injection gun with or without an injection needle and/or with or without the use of an injection plug. The appropriate protocol will depend upon various factors including the nozzle tip, the tree species, the target (insect, nematode, disease, abiotic stress, etc.), the injection liquid components and/or viscosity, the dose volume required and the injection pressure. After an injection is made, the trigger mechanism is reset to a base “untriggered” position and the pressure switch in the liquid supply assembly actuates the pump until the first chamber of the dosage assembly is refilled and ready for a subsequent injection.
[0010] A particular advantage of the inventive system is that the liquid to be injected can be provided by a standard, unpressurized product container. This reduces the chance for unwanted equipment leakage during use and attendant hygiene issues while also avoiding the need to maintain a pressurized bottle or container.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Having thus described the invention in general terms, reference will now be made to the accompanying drawings wherein:
[0012] FIG. 1 is a perspective view of a first side of a liquid supply assembly in accordance with one embodiment of the invention;
[0013] FIG. 2 is a perspective view of the liquid supply assembly shown in FIG. 1 with the product container removed from the liquid supply manifold;
[0014] FIG. 3 is a perspective view of a second side of a liquid supply assembly in accordance with one embodiment of the invention;
[0015] FIG. 4 a is a front plan view of the liquid supply assembly shown in FIG. 1 ;
[0016] FIG. 4 b is a side plan view of an injection gun assembly in accordance with one embodiment of the invention;
[0017] FIG. 5 is a schematic view of a liquid supply assembly in accordance with one embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Certain exemplary embodiments of this disclosure are described below and illustrated in the accompanying figures. The embodiments described are only for purposes of illustrating the present invention and should not be interpreted as limiting the scope of the invention, which, of course, is limited only by the claims below. Other embodiments of the invention, and certain modifications and improvements of the described embodiments, will occur to those skilled in the art and all such alternate embodiments, modifications, and improvements are within the scope of the present invention.
[0019] An example of a tree injection system of the present invention is described in the following, at least initially with reference to FIGS. 1-3 , in accordance with a first embodiment of this disclosure. A liquid supply system 10 includes a housing enclosure formed by side walls 12 a - 12 d , a base including a stabilizer 14 and a top portion including a manifold cover 26 and the various control components 28 , 30 and 32 . The enclosure may contain various components of the liquid supply system as shown in FIG. 5 including, among others, the pump 68 , motor 70 , battery 74 , pressure switch 72 and recirculation valve 78 .
[0020] In the exemplified embodiment, a liquid container 20 such as a product bottle that contains a liquid product to be injected 62 ( FIG. 5 ) is removably attached to the liquid supply system by removing the bottle lid (not shown) and then inserting the liquid supply inlet 34 into the top of the bottle 20 by positioning it on base 14 below the manifold 24 . For example, the liquid product may be one or more of insecticides, nematacides, fungicides, growth regulators, fertilizers, nutrients and/or other liquids that are suitable for being injected into trees. After it is properly positioned, the bottle 20 is then moved upward in the direction of arrow 35 through the bottle cage 18 a - 18 b to engage with the screw top 22 which is affixed to the bottom of manifold 24 . The liquid supply inlet 34 and liquid recirculation/vent pipe 66 pass through manifold 24 to provide fluid communication with the pump 68 and bottle 20 , respectively, at ambient pressure. The bracket 16 is closed after the bottle 20 is attached to the screw top 20 after which the tree injection system may be initiated.
[0021] Turning now to FIGS. 4 a -4 b , to initiate the system, if not already completed earlier, the dosing chamber 50 is calibrated to receive an appropriate injection dose of the selected liquid 62 (typically below 10 ml) and then a hand air pump (not shown) may be attached to the air supply valve 52 to pressurize the air chamber 48 of the dosing assembly 46 to an injection pressure appropriate to selected injection protocol, for example, typically between 2 to 4 bars. The appropriate injection pressure will depend on the protocol and/or tree species to be interrogated by the injection system. The power switch 32 is then placed in to the on position (while making sure that the emergency cut-off switch 30 is in the off position) in order to energize the pump motor 70 and start the pump 68 . The recirculation valve 78 is then opened with switch 28 (for example, for 4-5 sec) in order to charge the pump 68 , i.e., until the portion of the product tube 36 within the housing is filled with liquid 62 . The ambient pressure of headspace 64 during recirculation or normal operation is maintained by back pressure vent 80 . In the exemplified embodiment, opening the valve 78 pumps liquid from the product bottle 20 and recirculates it back to the bottle 20 via recirculation pipe 66 ). The pressure switch 72 is pre-set to a pressure above the pressure of air chamber 48 so that, once the recirculation valve 78 is closed, the liquid 62 is pumped out the port 38 through tube 36 to the gun 40 via inlet 41 into the dosing chamber 50 while the trigger 56 remains in the first upward position (as shown). The dosing chamber 50 is in fluid communication with the liquid supply system 10 while the trigger 56 is in such upward position. The pressure switch 72 and dosing chamber 50 are cooperatively associated so that the pump 68 remains actuated until the dosing chamber 50 is filled. For example, the pressure switch 72 can be set to turn off the pump 68 once the liquid pressure in the system downstream of the pump 68 reaches a value that is both higher than pressure in the air chamber 48 and also indicative of a condition where the dosing chamber 50 is filled with the injection liquid 62 . This can be a setting of from 5 to 7 bars, for example. Meanwhile, the pressure upstream of the pump 68 including the supply inlet 34 and the product bottle headspace 64 remain at ambient pressure.
[0022] Once the dosing chamber 50 is filled, an operator such as an arborist can take the gun 40 via palm grip 58 and handle 60 and engage the injection gun outlet 45 to a target tree via an appropriate borehole or opening. As noted above, the injection system of the invention can be used with injection protocols known in the art and the outlet 45 can be configured to accommodate a needle, to be used in needleless protocols, to set plugs, or the like, as dictated by the tree injection protocol being employed by the arborist/operator. Once the gun outlet 45 is engaged with a tree injection site, the operator will move the trigger 56 down to a second position (not shown) toward T-joint 42 of the main body of gun 40 . This second trigger position closes the fluid communication of the dosing chamber 50 to the liquid supply system 10 and opens the fluid communication of the dosing chamber 50 to the gun outlet 45 via barrel 44 . Once this occurs, the piston 54 is moved by the pressure in air chamber 48 (which is above ambient pressure) which pressure discharges the liquid from dosing chamber 50 through the gun outlet 45 at such pressure.
[0023] After the injection is complete the trigger 56 is released to return to the first position (for example, via a spring mechanism or the like) and the empty dosing chamber 50 is again in fluid communication with the liquid supply assembly 10 . The function of the trigger can, of course, be achieved by other activation means such as switches, buttons or remotely as known to those skilled in the art. At this point, the liquid pressure in the system downstream of the pump 68 is provided by the pressure in air chamber 48 . In accordance with an embodiment of the invention, as the pressure in air chamber 48 is lower that the value selected for the pressure switch 72 , the switch 72 actuates the pump 68 until the pressure returns to a pre-set value above ambient pressure that also corresponds to a pressure where the dosing chamber 50 is in a filled condition. Accordingly, use of the injection system of the invention requires significantly less time to inject multiple trees and/or trees with multiple injection sites as the dosing chamber can be emptied and filled quickly and automatically in rapid succession until the product bottle 20 is emptied or until the battery 74 is discharged. A discharged battery 74 can be recharged from a fixed or mobile power source via charging jack 76 . Moreover, empty product bottles 20 can be quickly replaced with a filled bottle 20 without turning off the system as the bottle and manifold 24 remain at ambient pressure. The tree injection system of the invention also avoids the need for decanting liquid product and for use of pressurized product bottles which improves operator safety and hygiene.
[0024] In the event of unforeseen circumstances, as shown in the exemplified embodiment, the system can be reset by pushing down on the switch cap 30 a of the emergency cut-off switch 30 . The cut-off switch 30 activates both the emergency electric switch 82 which turns off the pump motor 70 and also opens the recirculation valve 78 . In the exemplified embodiment, the recirculation valve is opened when the switch cap 30 a engages with lip 28 a of the recirculation valve switch 28 . Once this occurs, the downstream system pressure is provided by the air chamber 48 of the dosing assembly 46 which recirculates much of the liquid present in the gun 40 and line 36 back to the product bottle 20 .
[0025] By way of summary, the schematic of FIG. 5 discloses a product container 20 maintained at ambient pressure that contains tree injection liquid 62 which is pumped by pump 68 from liquid supply line 34 via supply tube 36 to the tree injection gun jet 40 at a selected pressure above ambient pressure and above the pressure in the air chamber 48 (which is also set above ambient pressure). During operation of the pump 68 , the headspace 64 of bottle 20 is maintained at ambient pressure (sometimes via operation of valve 80 and vent pipe 66 ) as liquid 62 is pumped from the bottle 20 and discharged through outlet 36 at a pressure above ambient pressure. The pump 68 is suitably a membrane pump that is selectively activated after the gun jet 40 is triggered to release liquid from the dosing chamber 46 , guided by a pressure valve 72 which stops the pump when the line pressure reaches a pre-set limit (e.g., 4-7 bars, more particularly 5-7 bars, or from 5 to 6 bars); suitably, the limit is selected to correspond with the dosing chamber 48 being in a filled condition. In one embodiment, the pump and other electric components are energized by a battery 74 . After operation, the main power switch 32 is switched off. To clean the system, the product bottle 20 can be replaced with a water bottle and the system is turned on. The tubes 34 / 36 and the injection gun 40 can be rinsed by several discharges of water through the injection gun 40 . Suitably, the discharged rinsing water is to be collected in a marked waste bottle for appropriate disposal.
[0026] Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims.
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There is provided by the present invention an injection system for use in injecting a liquid into a tree, the system comprising: (A) a liquid supply assembly ( 10 ) comprising a liquid supply inlet ( 34 ) for providing the liquid to the assembly at ambient pressure, an electric pump ( 68 ) for pressurizing and discharging the liquid from the assembly at a first pressure above ambient pressure through a liquid supply outlet ( 36 ), a pressure switch ( 72 ) connected to the supply outlet and in electrical communication with the pump for selectively actuating the pump when the pressure of the liquid supply outlet falls below said first pressure.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from Patent Application No. GB0422295.6 filed on Oct. 7, 2004 and entitled SYSTEM AND METHOD FOR DATA ENTRY.
FIELD OF THE INVENTION
[0002] This invention relates generally to the field of the entry of data into a data processing system, and more particularly to a system and method for reducing the likelihood of operator entry error.
BACKGROUND OF THE INVENTION
[0003] Many systems such as Global Positioning System (GPS) rely on the entry of multiple coordinates using keypads. In a GPS system, if one digit is mistyped then the navigation system might contain a positional error in the order of hundreds of kilometers. Equally, a navigational error in the order of meters can be dangerous and difficult to spot detect. Navigational errors are more likely in adverse climatic or acoustic conditions and many other situations where accuracy is often critical.
[0004] U.S. Pat. No. 3,593,311 discloses a data recorder with single operator entry-verify control, in which each character entered is compared with the character it is replacing and an error control bit is produced for an unequal comparison, requiring verification of any data entered during a verify cycle.
[0005] U.S. Pat. No. 6,748,568 discloses an apparatus and method for verifying proper data entry and detecting common typing errors, in which common keyboard typing errors are detected by using at least one parity bit. When error is detected, the data input operator can be warned or entry may be automatically suspended.
[0006] These approaches have the disadvantage that although errors in operator data entry may be detected, the result of such detection is only to require operator verification of the entry or to automatically suspend entry. A need therefore exists for a system and method for data entry wherein the abovementioned disadvantage is alleviated.
SUMMARY OF THE INVENTION
[0007] Briefly stated, a system and method for data entry by an operator uses data containing a first component and a second component derived therefrom, wherein the second component has error detection and correction abilities therein. The second component of the entered data is used to detect and correct error in the data entered for the first component. The first and second components are preferably characters (e.g., representing GPS position information) entered via a data entry device, while the second component preferably comprises Hamming code. The detection and correction can be performed after data entry and again after signal transmission.
[0008] According to an embodiment of the invention, a system for data entry includes means for operator entry of data containing a first component and a second component derived from the first component, wherein the second component includes error detection and correction abilities for the first component therefor; and means for receiving the entered data, deriving therefrom the second component, and using the second component to detect and correct error in the data received for the first component.
[0009] According to an embodiment of the invention, a method for data entry includes the steps of entering, by an operator using a data entry device, of data containing a first component and a second component derived therefrom, wherein the second component has error detection and correction abilities therein; and deriving from the entered data the second component and using the second component to detect and correct error in the data entered for the first component.
[0010] According to an embodiment of the invention, a program storage device readable by a machine, tangibly embodies a program of instructions executable by the machine to perform a method for verifying proper data entry into the machine using a data entry device, wherein the method includes the steps of receiving data containing a first component and a second component derived therefrom, wherein the second component has error detection and correction abilities contained therein; and determining from the received data the first component and the second component and using the second component to detect and correct error in the first component.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows a schematic diagram illustrating operator entry of GPS coordinates to a satellite navigation system.
[0012] FIG. 2 shows a flow chart illustrating the method used in the system of FIG. 1 ,
[0013] FIG. 3 shows a flow chart illustrating the method used to generate data for use in the system of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] Referring firstly to FIG. 1 , in a computer-based GPS navigation system 100 an operator (shown only by hands 200 ) enters GPS position data into a computer (e.g., a portable laptop personal computer) 300 via the computer's keyboard 310 . The computer 300 runs GPS navigation software (as is well-known and need not be described herein in further detail), and the entered geographic position 320 is displayed on the computer's display screen 330 . The operator might receive the GPS coordinate data from a variety of sources such as pre-coded information on printed maps, through audio instruction across radio communications, etc.
[0015] As will be explained in greater detail below, the operator may enter the GPS position data in an encoded form with one or more additional characters (e.g., numbers), and these additional characters can be used by the computer (by software—not shown—running on a processor—also not shown—within the computer) to detect error(s) in the key presses used to enter the data and to automatically correct the error(s).
[0016] Methods exist in signal transmission to incorporate error detection and correction digits (parity bits) onto a digital sequence. This can be used to reconstruct the original message in the presence of electrical noise or to raise an error flag in the presence of excessive noise. Normal language has a certain amount of built-in redundancy that usually allows a message to be reconstructed in the presence of some noise. The entry of a string of characters into a keypad for a system such as the GPS navigation system has heretofore not contained redundant information. Adding a number of characters to the key sequence can provide robust error detection and correction without either major technological change or significant process change. The entire operation can be performed in software.
EXAMPLE
[0017] Using numbers as an example, numbers in the range (0-9) occupy a small part of the total ASCII character set. A six-digit number string in base 10 may be represented efficiently as a twenty-digit binary number. Alternatively, the positional relationship of the key strokes to the binary message bits can be maintained if the binary number is encoded using twenty-four binary bits. This is a preferred implementation as the number of bit-errors arising from an incorrect keystroke is limited to four (in this example). It should also be noted that single-digit numbers in base 8 or lower may be encoded using three binary digits or less.
[0018] Encoding a binary number with error detection/correction bits is well understood, and typically involves the generation of parity bits. These parity bits may then be converted into ASCII text (or equivalent) and appended to the original message. The advantage of encoding the parity bits as text is that they can be entered using a data entry device (DED), and for purposes of this specification and claims, a DED includes a keyboard, keypad, voice recognition unit, or other human interface. Decoding the parity bits is then straightforward. The appropriate action can then be taken to correct the input automatically and possibly additionally to notify the user of a mistyped key. If automatic correction is not desired, the parity bits could be ignored by the user and flags suppressed subject to software coding for error handling and data entry.
[0000] Illustration:
[0019] Hamming coding is a well known technique for error correction and is frequently applied to binary data. Further information on Hamming coding is available from, for example, the website at http://www.ee.unb.ca/tervo/ee4253/hamming.htm or the website at http://www2.rad.com/networks/1994/err_con/hamming.htm.
[0020] The Hamming rule is expressed by the following inequality: d+p+1≦2 p , where d is the number of data bits and p is the number of parity bits. The result of appending the computed parity bits to the data bits is called the Hamming code word. The size of the code word c is obviously d+p, and a Hamming code word is described by the ordered set (c,d). For the case where a six-digit number in base 10 is encoded into twenty-four binary digits, then d=24. If d=24, then 25+p must be less than 2 p ; therefore p≧5. Five parity bits may be represented by a number in base 10. These parity bits then have a value less than 32 (in base 10). Thus, these bits may be encoded as two alpha or numeric characters—or even as one alphanumeric character in the range (0-9; a-z). Other strings may also be encoded using non-alphanumeric characters (e.g., @-#′/? . . . ).
[0021] In the example below, one of the numbers in the original character sequence has been entered incorrectly (Table 2) as part of GPS position data in the system 100 . Four binary digits are thus incorrect and are subsequently discovered by the parity bits. The example shows parity bits encoded into two characters for illustration. In practice, nine parity bits are needed to correct four bit-errors in such a sequence. This number of parity bits then can be encoded into three characters for transmission and subsequent decoding. The number of parity bits can be varied according to the nature of the character string.
TABLE 1 Original Character 2 0 5 8 5 6 (Number) Sequence: Binary Equivalent 0010 0000 0101 1000 0101 0110 +P{1 2 3 4 5 . . . } with Parity (P) calculated: Binary Encoding 0010 0000 0101 1000 0101 0110 0011 0000 with reformatted Parity mapped for keypad entry: Published characters with 2 0 5 8 5 6 3 0 Encoding including Reformatted Parity
[0022] The published characters are then sent via a transmission channel. We assume for this example that an error occurred in the fourth position during transmission or during receiving operator keyboard/keypad data entry.
TABLE 2 Keypad Input 2 0 5 7′ 5 6 3 0 with reformatted Parity and error (′) introduced into fourth character): Binary Decoding 0010 0000 0101 0111′ 0101 0110 0011 0000 showing location of error (′) in fourth character location: Recognized Input 2 0 5 8 5 6 error in fourth character corrected using Parity information (Parity discarded):
[0023] Thus, it can be seen that the parity data (the seventh and eighth characters entered in the published characters in Table 1 above) is used to automatically correct the error in the fourth character entered in the fifth table above.
[0024] It will be understood that a single key stroke typed in error can contain up to 8 bits in error using the entire standard ASCII range. Thus, the code must be capable of detecting potentially large numbers of incorrect bits. The aforementioned method is capable of expansion or contraction depending upon the application. Additionally, fewer parity bits are required to encode numbers in base 8 or lower.
[0025] Referring now also to FIG. 2 , the method used in the system 100 for automatic correction of operator entry is outlined in the following sequence 400 of steps. In step 410 , GPS position data characters (having a first portion and a second, parity portion) are entered by the operator as key presses on the keyboard 200 . In step 420 , the computer 300 derives the second, parity portion from the entered data. In step 430 , the computer 300 , using the parity data, automatically corrects error(s) in the first portion of the entered data.
[0026] Referring now also to FIG. 3 , the method for generation of enhanced GPS position data for subsequent use in the system 100 for automatic correction of operator entry (such as described in the steps 400 above) is outlined in the following sequence 500 of steps. In step 510 , an operator enters, via keyboard 200 , GPS position data having a first portion without parity. In step 520 , the computer 300 derives from the entered data a second, parity portion. In step 530 , the data in the first portion, together with the second, parity portion is published (e.g., in printed form) or transmitted to a data store (not shown) for future use.
[0027] It will be appreciated that the present invention is not limited to the ASCII character set. It will also be appreciated that the present invention is not restricted to detection/correction of a single keystroke. It will be further appreciated that the parity bits can be inserted at any predefined point in the message. It will be further appreciated that long sequences can be accommodated by splitting the sequence into smaller elements, each smaller elements having its own respective parity bits. It will be further appreciated that sequences with fewer characters than a preset number may be accommodated using padding bits.
[0028] Dividing the character string sequence and encoding each character into a predefined number of binary digits is an important part of the method and is necessary for efficient error correction. This sets a limit to the maximum number of incorrect bits received following mistyped key(s).
[0029] It will be further appreciated that the present invention is not limited to the Hamming code, and can alternatively utilize other error correction coding techniques. It will be further appreciated that the present invention is not restricted to GPS or navigational aids, and may be applied generally to a man-machine interface requiring data input. In addition, as an alternative to keyboard entry, the information may be transmitted and received reliably using non-electronic means such as voice or other audio, Braille, visual transmission, etc. The use of voice would allow voice recognition as the method of data entry.
[0030] The present invention reduces the risk of corruption through the signal channel, but there is always a risk of incorrect (initial) data being encoded. Most of the likely uses will generate the raw data for encoding from either a pre-existing database (e.g., a telephone directory) or automatically through a computer program (e.g., generating map coordinates for a map/navigation system). Such applications are likely to have their own automatic methods for verification. Where manual entry into a database is required, then the environment is usually more controlled and the appropriate level of manual checking might include manual verification by a second party. In less-controlled environments, double-checking by the person performing data entry might be more appropriate.
[0031] It will be appreciated that the system and method for automatic correction of data entry by an operator described above may (as mentioned above) be carried out in software running on a processor in the computer, and that the software may be provided as a computer program element carried on any suitable data carrier (not shown) such as a magnetic or optical computer disk.
[0032] In summary, it will be understood that the system and method for data entry described above addresses a major source of error at the man-machine interface, providing the following advantages: (a) reduced likelihood of operator entry error, (b) improved end-to-end system reliability, and (c) improved safety in mission-critical situations.
[0033] In another embodiment characters may be added onto the original character string to facilitate error detection and error correction i.e. encoding the original character string. The parity bits encoded within the original characters may be converted into ASCII text (or equivalent) and appended to the original character string as additional characters. The advantage of encoding the parity bits as text is that the parity bits can be entered using a standard keyboard or other input device. The encoded original character string is then transmitted across an interface for decoding separately as is shown in FIG. 3 .
[0000] Illustration:
[0034] As previously stated, the Hamming rule is expressed by the following inequality:
[0035] d+p+1≦2 p , where d is the number of data bits and p is the number of parity bits. The result of appending the computed parity bits to the data bits is called the Hamming code word. The size of the code word c is obviously d+p, and a Hamming code word is described by the ordered set (c,d). For the case where a six-digit number in base 10 is encoded into twenty-four binary digits, then d=24. If d=24, then 25+p must be less than 2 p ; therefore p≧5 for single error correction.
[0036] Five parity bits may be represented by a number in base 10. These parity bits then have a value less than 32 (base 10). Thus, these bits may be encoded as two alpha or numeric characters—or even as one alphanumeric character in the range (0-9; a-z). Other strings may also be encoded using non-alphanumeric characters (e.g., @-#′/? . . . ).
[0037] Table 3, below, expands on the parity requirements for a six-character string. The number of parity bits is tabulated together with the equivalent number of keypad characters necessary to complete the transmission. It will be seen that an additional five characters need to be appended to provide full single-keystroke (4-bit) protection and automatic recovery.
TABLE 3 Single-Bit Double-Bit Triple-Bit Quad-Bit Error- Error- Error- Error- Correction Correction Correction Correction (BEC) (BEC) (BEC) (BEC) Parity Bits 5 bits 10 bits 15 bits 20 bits Required Encoded Parity 2 characters 3 characters 4 characters 5 characters Characters for Keypad Input (4 bits per character)
[0038] The parity overhead reduces as the number of bits or characters in the protected string increases. The above example represents a worst-case study for a typical problem.
[0039] While the present invention has been described with reference to a particular preferred embodiment and the accompanying drawings, it will be understood by those skilled in the art that the invention is not limited to the preferred embodiment and that various modifications and the like could be made thereto without departing from the scope of the invention as defined in the following claims.
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A system and method for data entry by an operator uses data containing a first component and a second component derived therefrom, wherein the second component has error detection and correction abilities therein. The second component of the entered data is used to detect and correct error in the data entered for the first component. The first and second components are preferably characters (e.g., representing GPS position information) entered via a data entry device, while the second component preferably comprises Hamming code. The detection and correction can be performed after data entry and again after signal transmission.
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BACKGROUND OF THE INVENTION
This invention relates generally to an improved method for lubrication of metal workpieces being formed at elevated working temperatures of at least 250° C. and higher and more particularly to a novel lubricant combination for such method of metal forming which includes formation of a novel polymer lubricant in situ at the elevated working temperatures.
Various lubrication means are known whereby metal workpieces being formed at elevated temperatures with one or more die members, such as by forging or by extrusion, are provided with lubrication both prior to and during the metal forming operations. Both workpieces and die members are often heated to very elevated temperatures, particularly if ferrous metals are being formed, with the lubricant often being supplied in copious quantities to provide both lubrication and cooling of the die members. For example, U.S. Pat. No. 2,821,016 describes the hot forging of steel billets or slugs preheated at temperatures up to 2300° F. and thereafter formed with movable and fixed die members being maintained with the liquid lubricant below 1000° F. In doing so, the die members are flooded with a lubricating solution of colloidal graphite suspended in water containing a soluble oil. While such lubrication is reported to prevent "score+ marks on the forged product and die members, it has also been found that considerable cleaning of these articles is required to remove adherent carbon particles.
Other water-based lubricants have similarly been employed which are said to provide better lubrication means than achieved with "oil-base+ suspensions of graphite and still other particulates. For example, there is disclosed in U.S. Pat. No. 4,401,579 a lubricant composition employing fumaric acid salts as the primary lubricating and release agent for use in forging operations. As therein employed, such lubricant compositions can further include other suitable thickeners and polymethacrylates, polyvinyl alcohol, starch, gelatin, gum arabic and polysaccharides along with sufactants, wetting and dispersing agents. Suitable use of such lubrication means is further said to include other metal forming operations such as drawing, press forming, extrusion, wire drawing and other processes where workpiece temperatures reach at least about 800° F. In a reported test the die members were preheated to 500° F. with the die members being sprayed with the disclosed lubricant while low carbon steel billets heated to 2150° F. were being forged therein. A different lubricant composition is disclosed in U.S. Pat. No. 4,765,917 for use in elevated temperature metal forming operations. This water-based lubricant is said to comprise about one percent to about forty percent by weight of a polycarboxylic acid salt reaction product, such as trimellitic acid and an alkali metal or an alkaline earth metal hydroxide such that the pH of the composition is about 6.5 to about 10 along with about 0.1 percent to about 12 percent by weight of a water dispersible thickening agent, and the balance water. Said water-based lubricant is said to further optionally include extreme pressure additives, performance enhancers and biocidal agents. Representative extreme pressure additives are said to include phosphate esters while listed performance enhancers include ammonium phosphate and alkali-metal polyphosphates. As therein employed, such lubricant composition is reported suitable in hot forging processes and other metal forming operations such as drawing, press forming, extrusion, wire drawing and like processes where workpiece temperatures generally reach at least about 1100°-1300° F. for aluminum pieces and 1300° F.-2300° F. (generally 1800°-2000° F.) for steel workpieces. The average die temperature is reported to be about 600° F. with die temperatures varying from about 250° F. to 900° F. A reported test for hot drawing of steel artillery shell casings supplied such lubricant to the preheated punch or ram members over a time period varying between eight to eleven seconds with said time period said to be less than a twenty second spray period previously required with another prior art lubricant.
Various solid lubricants have also been employed as powders or particulates during the formation of metal workpieces at the aforementioned elevated work temperatures. A glass powder for such use is disclosed in U.S. Pat. No. 4,788,842 when forging ferrous alloy billets at working temperatures between about 800° C. and 1200° C. The solid lubricant is said to be removed from the finished article by sand blasting to produce a near metallic finish. In conducting the reported metal forming operation, such glass lubricant is applied as a coating to the preheated workpiece with the coated workpiece thereafter being forged. A different powdered lubricant is disclosed in U.S. Pat. No. 5,081,858 for the forging of hard to work metals such as stainless steel. The reported lubricant particles are electrically charged with high voltage for deposition on the preheated metal workpiece with the coated workpiece thereafter being found suitable for use in both cold and hot forging operations. Listed powdered lubricants include phosphoric acid, zinc calcium phosphate, metallic soap and oxalates.
It is also well known to lubricate various type mechanical systems operating at elevated temperatures with load bearing surfaces in dynamic physical contact, such as journal bearings, piston rings, gears, cams and the like. As the operating temperatures for these systems reach 300° C. and higher so as to even approach the melting points of conventional metals now being employed, it has become essential that more effective lubrication be provided. A recently developed lubrication means for ceramic bearing surfaces is disclosed in U.S. Pat. No. 5,139,876. As therein described, formation of a tenacious lubricating film is achieved upon treating the uncoated ceramic bearing surfaces at elevated temperatures with activating metal ions to form a deposit of the activating metal ions on the ceramic surface and thereafter exposing the treated ceramic surface to a vaporized polymer-forming organic reactant at elevated temperatures whereby an adherent solid organic polymer lubricating film is produced on the treated surface. Bearing surfaces formed with crystalline ceramic materials such as silicon nitride and silicon carbide as well as vitreous ceramics such as fused quartz can be provided with a protective coating resistant to dynamic wear conditions up to at least 500° C. and higher in this manner. In one embodiment, activated metal ions comprising a transition metal element is selected from the Periodic Table of Elements, to include iron and tin are initially deposited at temperatures of at least 300° C. on the ceramic surface. Formation of a lubricating film on the treated ceramic surface is achieved with vapor deposition again being conducted at elevated temperatures of approximately 300° C.-800° C. with various polymer forming organic reactants such as petroleum hydrocarbon compounds, mineral oils, various synthetic lubricants and to further include tricresyl phosphate (TCP) and triphenyl phosphate. Similarly, a copending application Ser. No. 07/937,425 entitled "High Temperature Lubrication For Metal and Ceramic Bearings", filed Aug. 31, 1992, in the names of Edgar Earl Graham and Nelson H. Foster, now U.S. Pat. No. 5,351,786, describes lubrication means provided with still other novel organic polymer lubricants formed in situ. In said method of lubrication, both metal and ceramic bearing surfaces undergo reduction of the friction coefficient and surface wear when provided with a novel class of phosphazene polymer lubricants vapor-deposited during atmospheric bearing operation at elevated temperatures of at least 300° C. During such operation the phosphazene starting compound becomes initially vaporized then polymerized in the vapor phase for subsequent deposition of the polymer product in lubricating amounts on at least one of the moving bearing surfaces. Suitable precursor reactants for such lubrication means include linear phosphazene, cyclophosphazene and cyclotetraphosphazene, including mixtures thereof, with a preferred reactant containing bis(4-fluorophenoxy)-tetrabis(3-trifluoromethylphenoxy) cyclotriphosphazene.
In a still more recently filed copending Ser. No. 08/109,949 application, filed Aug. 23, 1993 in the name of the present applicant and entitled "Elevated Temperature Metal Forming Lubrication", there is disclosed novel lubrication means when forming a preheated metal workpiece with a forming die at forming temperatures of at least 250° C. The disclosed lubrication means polymerizes a vaporizable and polymerizable organic reactant selected from the group consisting of phosphate esters and phosphazene compounds to form a solid polymer lubricant in situ when contacting the forming die with the preheated workpiece. A water-based suspension containing such organic reactant can be applied to the shaping region of the forming die as well as further applied to the preheated metal workpiece in carrying out the disclosed lubrication means. Evaluation tests reported in FIG. 2 of said copending application demonstrate an average five percent reduction in applied pressure during the hot forging of a steel workpiece with the disclosed lubrication means as compared with employment of a conventional graphite lubricant. In the disclosed evaluation, a water-based graphite lubricant containing about sixteen percent by volume graphite was compared with an aqueous emulsion formed by adding ten percent by volume ethanol and 0.5% by volume Durad 620B to water. The Durad 620B precursor lubricant is a commercially available tertiary-butylphenyl phosphate ester supplied by FMC Corporation under said trade name.
It is one object of the present invention, therefore, to provide a still further improved method for lubrication of metal workpieces being formed at elevated working temperatures which is less subject to the cost and shortcomings now being experienced with conventional lubrication means.
It is another object of the present invention to provide novel lubrication employing polymer lubricants in combination with graphite particulates for use in various metal forming operations at elevated temperatures.
It is a still further object of the present invention to provide a novel method for lubrication of metal workpieces being formed at elevated temperatures which employs relatively low lubricant levels.
These and further objects of the present invention will become apparent upon considering the following detailed description of the present invention.
SUMMARY OF THE INVENTION
It has now been found, surprisingly, that still more effective and efficient lubrication is provided with a small but effective amount of graphite lubricant being incorporated into the water-based starting lubricant disclosed in the aforementioned copending Ser. No. 08/109,949 application. More particularly, an addition of approximately 0.5 percent by volume graphite particulates in the therein disclosed aqueous emulsion containing said Durad 620B precursor lubricant enables significantly lower applied pressures to be employed when carrying out the forming of metal workpieces in otherwise the same manner. While graphite is an already recognized lubricant in various hot forging process, that its effect in combination with the phosphate ester is to still further lower applied pressures far below that previously experienced was simply not expected. Such combined lubrication means further enables considerably more satisfactory workpieces to be formed than was produced with Durad 620B lubrication alone at much higher applied pressures.
Accordingly, the essential steps in the presently improved method thereby requires (a) contacting the shaping region of the forming die with a liquid mist of a lubricant preparation containing a vaporizable and polymerizable organic reactant selected from the group consisting of phosphate esters and phosphazene compounds in combination with graphite particulates, (b) polymerizing the organic reactant in the applied lubricant preparation to form a solid polymer lubricant in situ, (c) forming the preheated metal workpiece with the lubricated forming die, and (d) removing the formed workpiece from the lubricated forming die. In one representative embodiment, the combined lubrication means of the present invention can be prepared for application as a simple physical admixture having the essential organic reactant and graphite particulates suspended together in an aqueous medium. Since the water-based emulsions disclosed in the previously identified copending Ser. No. 08/109,949 application can be employed for preparation of the present lubricant combination, the entire content of said application is hereby specifically incorporated by reference into the present application. For example, simply adding an aqueous colloidal graphite suspension to the previously disclosed water-based emulsions already having a suitable organic reactant suspended therein provides a satisfactory starting lubricant combination for use in accordance with the present invention. Application of the selected starting lubricant combination in accordance with the present invention can be carried out prior to conducting the actual metal forming operation as well as during an otherwise conventional metal forming process of this type. Thus already known manufacturing procedures which forge steel, titanium and nickel products from the heated billets in a continuous manner can be further improved with employment of the present lubrication means. The present lubricant combination can also be applied to a wide variety of forming dies including single die members having an internal cavity wherein the preheated metal workpiece is formed as well as multiple cavity die members and multi-part die constructions. Similarly the present lubricant combination can be applied to the die construction alone am well as applied to both heated metal workpiece and die construction while further having said die construction also being maintained at a sufficiently elevated temperature to remove liquid from the applied starting lubricant combination.
In a representative hot forging operation employing such combined means of lubrication with a ferrous alloy workpiece heated to at least 800° C. in a ferrous alloy forging die heated to around 150° C., the present method employs the steps of (a) exposing both workpiece and internal cavity of the forging die under atmospheric conditions and while heated at the specified elevated temperatures to a liquid mist formed with the present lubricant combination which includes a vaporizable and polymerizable aromatic phosphate compound and an organic liquid solvent therefor, (b) polymerizing the aromatic phosphate compound in the vapor-phase while in contact with the heated workpiece and the heated internal cavity of the forging die to form a vapor-deposited polymer lubricant on the contacted surfaces, (c) forging the lubricated workpiece in the lubricated forging die, and (d) removing the forged workpiece from the forging die. For other preferred embodiments employing aromatic phosphate compounds which are already liquid at ambient conditions such as tricresyl phosphate and triphenyl phosphate, the organic solvent can be eliminated from the present starting lubricant composition.
Representative phosphate esters found useful in the present lubrication method include triaryl phosphate esters such as tricresyl phosphate and triphenyl phosphate, mixed cresyl-xylenyl phosphates and cresyl-diphenyl phosphates. Correspondingly, the suitable phosphazene compounds include linear phosphazene, cyclophosphazene and cyclotetraphosphazene, with a preferred commercial product being available from the Dow Chemical Company as X-1P containing bis(4-fluorophenoxy)-tetrabis(3-trifluoromethylphenoxy) cyclotriphosphazene. A suitable graphite material for direct use in the present starting lubricant combination is finely divided colloidal graphite which is commercially available from numerous suppliers generally as a thick aqueous slurry containing from 10-20 volume percent of the graphite particulates.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating representative forging equipment employed to conduct metal forming according to the present invention; and
FIG. 2 is a graph enabling comparison to be made between lubrication provided with prior art graphite and phosphate esters lubricants and that afforded in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
There is depicted in FIG. 1, a block diagram representing typical hot forging equipment 10 which can be employed to form the organic polymer lubrication means of the present invention. Said conventional press apparatus 10 utilizes a commercially available 1300 ton press 12 sold by the Viking Forge Corporation, Streetsboro, Ohio in combination with three sets of fixed and movable die members 14, 16 and 18 being employed in a sequential manner. In customary practice, a steel workpiece is first preheated by induction heater 20 to about 2000° F. and transferred to the cooperating fixed and movable heated die members (not shown) in die set 14 for an initial forming step taking place with about 200 tons of applied pressure. Said workpiece is then immediately transferred to the cooperating die members of intermediate die set 16 where principal forming of the workpiece takes place at elevated working temperatures often exceeding 250° F. while applied pressures reach 1400 tons and greater. A final finishing step in forming the still heated workpiece to the desired shape and size is formed in die set 18 at applied pressures of about 1000 tons. Any surface scale formed during said forging process is thereafter generally removed from the finished article with shot-blasting or similar means 22. Heretofore, the die cavities (not shown) in all three die sets were flooded prior to the forging steps with a water-based lubricant 24 containing about sixteen percent by volume of graphite lubricant at a rate of about fifty-five gallons of said prior art lubricant being employed to forge 1045 steel workpieces during an eight hour work period in die sets constructed with H13 steel alloy. Such conventional lubrication means for steel forging has produced some undesirable sticking of the steel workpiece in the forming die cavities leading to premature failure of the die sets through rapid wear and destruction. An additional problem encountered with employment of said conventional lubrication means in the illustrated forging embodiment is believed again due to insufficient lubrication being provided at elevated working temperatures varying between 250° F. up to 900° F. which produced higher than desirable applied pressures being required during the intermediate forming step in excess of 1400 tons applied pressure.
In contrast thereto, much superior die lubrication is experienced in the above illustrated embodiment upon substituting the organic polymer lubricants disclosed in the copending Ser. No. 08/109,949 application. Comparative test results reported in said copending application demonstrated a five percent reduction in applied pressure being achieved with a starting lubricant emulsion formed upon adding ten percent by volume ethanol and 0.5 percent of a commercial aromatic phosphate compound (Durard 620B) to water. For a test evaluation of the present lubrication means, still further comparative tests were conducted in the same manner employing a starting lubricant which now added a small but effective amount of graphite particulates to the previously tested phosphate containing emulsion. Specifically, said previously tested emulsion was modified to further include 0.5 volume percent colloidal graphite and 0.5 volume percent of a commercial surfactant (ICI Tween 80). The particular graphite material that was employed was obtained from the Rite Lube Corporation as a seventeen percent aqueous slurry.
A graph depicting the applied pressure for intermediate die set 16 in the above illustrated forging embodiment when different lubrication means are employed is shown in FIG. 2. Plot 24 lists applied pressure values measured for a successive number of steel workpieces being processed with conventional graphite lubrication. Plot 26 provides the same measurements for said workpieces with lubrication being provided by the above illustrated phosphate containing emulsion devoid of graphite particulates. The measured applied pressure values for successive workpieces being lubricated with said above illustrated phosphate emulsion which now includes graphite are depicted in Plot 28 of said graph. As can be seen from said comparison, the later lubrication means in accordance with the present invention demonstrates a significant reduction in the applied pressure needed for production of a satisfactory forged product and continues to do so for a far greater number of workpieces than realized with the other lubricants. A still further benefit noted in conducting said evaluation is the absence of adherent graphite particles on the forged articles when employing the lubrication means of the present invention whereas articles lubricated with the conventional graphite lubrication required considerable graphite removal.
It will be apparent from the foregoing description that broadly useful and novel means have been provided to continuously lubricate metal workpieces being formed at elevated working temperatures of at least 250° C. It is contemplated that the present lubrication method can be applied to a broad range of metal forming processes other than that above illustrated, however, to include drawing, extrusion, wire drawing and still other elevated temperature metal working processes. Likewise, it is contemplated that the liquid lubricant compositions being applied in the present method of lubrication can be further modified for improved performance to include possible incorporation of additional graphite for lubrication as well as adding still other ingredients to the disclosed emulsions for increased stability during storage and use. Consequently it is intended to limit the present invention only by the scope of the appended claims.
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An improved method to lubricate a metal workpiece at elevated temperatures is described employing a novel polymer lubricant formed in situ. The novel lubricant is provided with a liquid mist of a lubricant preparation containing a vaporizable and polymerizable organic reactant in combination with graphite particulates being supplied to both workpiece and forming die at the elevated working temperatures.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] The application claims the benefit, under 35 U.S.C. §119(e), of U.S. Provisional Application Ser. No. 60/807,217 filed Jul. 13, 2006, the contents of which are incorporated herein by reference.
ORIGIN OF THE INVENTION
[0002] The invention described herein was made in the performance of work under a NASA contract and by employees of the United States Government and is subject to the provisions of Public Law 96-517 (35 U.S.C. §202) and may be manufactured and used by or for the Government for governmental purposes without the payment of any royalties thereon or therefor. In accordance with 35 U.S.C. §202, the contractor elected not to retain title.
TECHNICAL FIELD OF THE INVENTION
[0003] The present invention relates generally to thermocouples and in particular to the thermocouple designs capable of self validation.
BACKGROUND OF THE INVENTION
[0004] The basic concept of a sensor automatically monitoring its operational capability, i.e., self-validating performance, is generally recognized. An attempt is made to continuously monitor and self-validate the sensor's performance to determine the health of the sensor. The process of self-validation involves the continued assessment of a combination of: 1) reviewing physical parameters obtained real-time by means of electronic circuitry to obtain actual measurement data; and 2) utilizing a combination of statistical tools to estimate and predict a measurement value at a given time in the process and compare the predicted measurement value to the actual measurement data. Self-validation processes used by others include ARMA (Auto Regression Moving Average), LCSR (Loop Current Step Response), and Power Spectrum Density determination. The failure or success of any of these processes presupposes properly functioning sensor circuitry.
[0005] However, in many sensors, and particular thermocouples, the actual cause for failure is directly related to the physical bonding between the thermocouple sensor element and the attachment surface. As a consequence, conventional self-validating techniques may fail to reliably identify the bonded/debonded condition that directly leads to sensor failure.
[0006] For the reasons stated above, and for other reasons that will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for alternative approaches to thermocouple validation.
SUMMARY OF THE INVENTION
[0007] The various embodiments provide a Self-Validating Thermocouple (SVT) System capable of detecting sensor probe open circuits, short circuits, and unnoticeable faults such as a probe debonding and probe degradation. The various embodiments provide such capabilities by incorporating a heating or excitation element into the measuring junction of the thermocouple. By heating the measuring junction and observing the decay time for the detected DC voltage signal, it is possible to indicate whether the thermocouple is bonded or debonded. A change in the thermal transfer function of the thermocouple system causes a change in the decay time for the DC voltage signal. The various embodiments are further capable of traditional validation procedures as the excitation elements in accordance with the various embodiments do not interfere with the normal operation of the thermocouple.
[0008] The invention includes methods and apparatus of varying scope.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic of a basic thermocouple design.
[0010] FIGS. 2A and 2B depict portions of two thermocouple circuits having measuring junction excitation elements for use with the various embodiments.
[0011] FIG. 3 is a block schematic of a thermocouple system in accordance with an embodiment of the invention.
[0012] FIG. 4 is a flowchart of a method of validation in accordance with one embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0013] In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific preferred embodiments in which the inventions may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that process, mechanical, and electrical changes may be made without departing from the spirit and scope of the present invention. It is noted that the drawings are not to scale unless a scale is provided thereon. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims and equivalents thereof.
[0014] It is well known that a metal or other conductor subjected to a thermal gradient will generate a voltage. To measure the voltage, a closed circuit must be provided, thus requiring a return conductor. If the same material were used for the return conductor, its temperature-generated voltage would cancel out the voltage of the first conductor. However, the voltage response is dependent upon the conductor itself. By using a dissimilar metal for the return conductor, a measurable voltage differential will be developed that is related to the temperature gradient experienced by both conductors.
[0015] FIG. 1 is a schematic of a basic thermocouple design. The thermocouple 100 includes a first conductor 102 and second conductor 104 . Two junctions 106 and 108 are formed where the two conductors are joined, and the voltage differential can be read across nodes 110 and 112 . One junction, such as junction 106 , is a measuring junction while the remaining junction, such as junction 108 , is the reference junction.
[0016] The various embodiments include a heating or excitation element at the measuring junction. FIGS. 2A and 2B depict portions of two thermocouple circuits 200 A and 200 B having measuring junction excitation elements for use with the various embodiments. In FIG. 2A , the thermocouple 200 A includes a first capacitor 220 , a resistor 222 and a second capacitor 224 coupled in series at the measuring junction 206 . The thermocouple 200 A further includes a first inductor 228 and a second inductor 230 coupled in series with the measuring junction 206 . The resistor 222 acts as an excitation element. Elements located above the dashed line in FIG. 2A may generally be located on a circuit board of a thermocouple system while elements below the dashed line would be located at the sensing element. The excitation element 222 is in thermal contact with the measuring junction 206 . That is, the excitation element 222 is sufficiently coupled to the measuring junction to cause a temperature rise in the measuring junction 206 upon application of the alternating current (AC) stimulation signal. The excitation element 222 need not be in physical contact, and may be separated by a thermal compound capable of thermal transfer.
[0017] By applying an AC signal from the excitation and signal conditioning circuitry 226 , such as a pulse width modulated signal, to resistor 222 the measuring junction 206 will heat up. The AC stimulation signal, by itself, does not affect the thermocouple measuring junction 206 because inductors 228 and 230 act as an open circuit to the AC signal. In a similar manner, the DC voltage generated by the thermocouple will not affect the resistor 222 voltage since the capacitors 220 and 224 act as an open circuit to the DC signal. While two capacitors 220 and 224 and two inductors 228 and 230 are depicted in the embodiment of FIG. 2A , one capacitor and one inductor would suffice in that the path to the excitation element 222 could still act as an open circuit to a DC signal with one capacitor in the loop to the excitation and signal conditioning circuitry 226 and the path to the measuring junction 206 could still act as an open circuit to an AC signal with one inductor in the loop to the excitation and signal conditioning circuitry 226 . Other circuit configurations can also be used to satisfy these criteria. For one embodiment, the same lead could be used to supply the AC signal to the resistor 222 and to read the measuring junction 206 . For example, capacitor 220 and inductor 228 could both be coupled to a single lead in the excitation and signal conditioning circuitry 226 , and capacitor 224 and inductor 230 could both be coupled to a single lead in the excitation and signal conditioning circuitry 226 such that a circuit path containing the resistor 222 would be coupled in parallel with a circuit path containing the measuring junction 206 .
[0018] In FIG. 2B , the thermocouple 200 B includes one inductor 228 coupled in parallel with series-coupled capacitor 220 and resistor 222 between the excitation and signal conditioning circuitry 226 and the measuring junction 206 . The resistor 222 acts as an excitation element. Elements located above the dashed line in FIG. 2B may generally be located on a circuit board of a thermocouple system while elements below the dashed line would be located at the sensing element. The excitation element 222 is in thermal contact with the measuring junction 206 . The excitation element 222 need not be in physical contact, and may be separated by a thermal compound capable of thermal transfer. For a further embodiment, the same lead could be used to supply the AC signal to the resistor 222 and to read the measuring junction 206 . For example, capacitor 220 and inductor 228 could both be coupled to a single lead in the excitation and signal conditioning circuitry 226 such that a circuit path containing the resistor 222 would be coupled in parallel with at least a portion of a circuit path containing the measuring junction 206 .
[0019] By applying an alternating current (AC) signal, such as a pulse width modulated signal, to resistor 222 the measuring junction 206 will heat up. The AC stimulation signal, by itself, does not affect the thermocouple measuring junction 206 . In a similar manner, the DC voltage generated by the thermocouple will not affect the resistor 222 voltage since the capacitor 220 acts as an open circuit to the DC signal. Other designs may be utilized with the various embodiments, provided that the resulting excitation element provides one path inhibiting an AC signal and another path providing an open circuit to a DC signal. The embodiment of FIG. 2A adds improved noise immunity to the thermocouple circuit using a four-wire configuration while the embodiment of FIG. 2B reduces physical interfacing by using a three-wire configuration. As shown in FIG. 2B , a circuit path containing the resistor 222 may also include the measuring junction 206 .
[0020] Thermocouples including excitation elements in accordance with embodiments of the invention are compatible with traditional thermocouple systems. Typical systems would provide instrumentation such as a cold junction compensator, signal conditioner circuitry, analog/digital (A/D) converter, processor, power section, and system interface, e.g., a universal serial bus (USB) interface or the like. However, the various embodiments would further include thermocouple excitation means and a pulse wave modulator (PWM).
[0021] FIG. 3 is a block schematic of a thermocouple system 350 in accordance with an embodiment of the invention. The thermocouple system includes a measuring junction 306 and reference junction 308 . The measuring junction 306 includes an excitation element 322 in accordance with an embodiment of the invention. The excitation element 322 is coupled to receive an AC stimulation signal from PWM 354 through excitation circuitry 352 . A cold junction compensator 356 and signal conditioner circuit 358 are coupled to receive the detected DC signal from the measuring junction 306 . An A/D converter 360 is coupled to receive the compensated and conditioned signal and provide a digital signal representative of the expected temperature of the measuring junction 306 to the processor 362 . Interface (I/F) 364 is coupled to the processor 362 to provide input/output (I/O) capabilities to receive commands at the processor 362 to perform various validation methods in accordance with the embodiments, and to provide data output of the detected temperature and of detected health of the system 350 . Power section 366 may provide power to the various elements of the system 350 . Alternatively, power may be received through the I/F 364 .
[0022] A memory 368 may be included to store historical data on rise and/or decay times of the DC signal of the measuring junction 306 during validation. Preferably, the memory 368 is a non-volatile memory, such as flash memory or EEPROM (electrically erasable programmable read-only memory), so that historical data is retained in case of a power failure.
[0023] During operation of a self-validating thermocouple in accordance with the various embodiments, the following occurs.
[0024] Temperature measurement: The A/D converter measures the very small (μV to mV) voltage of the thermocouple and the cold junction compensators. Since the output voltage of the thermocouple is between μV and mV, it is generally necessary to use the internal gain of the A/D converter. The A/D converter also monitors the output of the cold junction compensator. Depending on the type of thermocouple used, the processor compensates the thermocouple output to obtain an accurate reading as is well understood in the art. The temperature may be calculated by using the following equation: Ttip=A 0 +A 1 Vout+A 2 Vout 2 + . . . +AnVout n . Alternatively, the temperature could be generated from a look-up table. Software in processor 362 can assist the user to operate in learning mode to automatically gather historical data of the thermocouple system during operation (monitoring and diagnostic mode). The user can also manually enter historical data.
[0025] Thermocouple Validation: To observe if the thermocouple is short or open, each differential line of the thermocouple is measured as being single ended to estimate the common mode. The leakage resistance of the capacitors of the AC-coupled PWM will either pull high or low any lead as the result of an open circuit. This condition can be detected by the processor, which then flags the condition as one of the failure modes. The thermocouple is slightly biased to have a common mode offset, which will change in the case of a short circuit. This condition can also be detected by the processor and flagged as another failure mode.
[0026] Bonding/Debonding Detection: Debonding of the thermocouple is evaluated based on a departure from a known thermal transfer function of the bonded system. When debonding occurs, the reduction in thermal mass translates into a different temperature rate of change, resulting in different rise and decay times. The processor sends a PWM excitation signal for the length of time needed to heat up the thermocouple. The difference in temperature (d[temp]/dt) and the time it takes to return to the original temperature before the excitation of the thermocouple indicates the health of the thermocouple and whether the thermocouple is bonded or debonded. For example, the thermocouple in a bonded condition will have faster decay in temperature, and thus detected DC voltage, than if it were in an unbonded condition. In addition, historical values of the rise and decay times can be compared with current values to indicate degradation of the thermocouple.
[0027] An operator may commence operation by selecting to start a diagnosis/monitoring sequence, wherein the PWM is used to estimate the time constants corresponding to the correct configuration. The user has the further option of using previous diagnostic values, which are stored in memory and readily available upon each commencement of operation.
[0028] FIG. 4 is a flowchart of a method of validation in accordance with one embodiment of the invention. The method of FIG. 4 may be initiated by an operator request, or the processor of the thermocouple system may be configured to periodically initiate the validation method, such as daily, weekly, or monthly. At 480 , an AC excitation signal is applied to the thermocouple. At 482 , the rise time and/or decay time of the DC signal of the thermocouple are observed. A thermocouple that is bonded to an object of interest, i.e., the object whose temperature is desired to be measured, will exhibit differing rise and decay times of its DC signal during and after, respectively, AC excitation. Optionally, the rise and/or decay times can be compared to historical data at 484 . Historical comparisons can be especially useful in detecting degradation of the thermocouple measuring junction where trends in the times can be observed. Values that are trending in one direction or the other, as opposed to random variation, can be indicative of degradation of the thermocouple. This failure mode may be used to indicate a need for calibration, repair, or replacement.
[0029] If the raw observations for rise and/or decay times at 482 , of the trend observations at 484 , indicate a failure at 486 , the resulting failure mode may be transmitted to the user or host system at 488 . If no failure is indicated at 486 , the validation may end at 490 .
[0030] The Self-Validating Thermocouple (SVT) System in accordance with the various embodiments not only facilitate detection of open or short faults, but also facilitates identification of degradation of the thermocouple as well as its bonded or debonded state. The SVT system may provide signal conditioning and data acquisition capability in-situ to each thermocouple. It is capable of interfacing and processing signals from the most commonly used thermocouple types (J, K, E, and T) as well as other thermocouple types. The SVT can periodically evaluate the health of the thermocouple and the measurement capability. The circuit is capable of detecting failures and notifying the user/operator of the failure mode. The SVT may automatically provide a stream of data to be analyzed, or the SVT may respond to individual requests at any time, i.e., on demand.
[0031] SVTs in accordance with the various embodiments will be valuable for anyone using thermocouples as temperature sensors that require highly reliable measurements. The invention could allow elimination of the need for redundant thermocouple measurements which, in turn, translates into savings in operating and maintenance costs. Finally, the present invention facilitates increased failure detection capabilities as well as improved dating validity and reliability.
[0032] Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement that is calculated to achieve the same purpose may be substituted for the embodiments shown. This application is intended to cover any adaptations or variations of the present invention. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.
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Self-Validating Thermocouple (SVT) Systems capable of detecting sensor probe open circuits, short circuits, and unnoticeable faults such as a probe debonding and probe degradation are useful in the measurement of temperatures. SVT Systems provide such capabilities by incorporating a heating or excitation element into the measuring junction of the thermocouple. By heating the measuring junction and observing the decay time for the detected DC voltage signal, it is possible to indicate whether the thermocouple is bonded or debonded. A change in the thermal transfer function of the thermocouple system causes a change in the rise and decay times of the thermocouple output. Incorporation of the excitation element does not interfere with normal thermocouple operation, thus further allowing traditional validation procedures as well.
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RELATED APPLICATION
This application is a continuation-in-part of my copending U.S. patent application Ser. No. 48,091, filed June 13, 1979, now abandoned entitled "Roofing Composition and Structure".
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to building materials, and more particularly to roofing compositions.
2. Prior Art
Historically the most popular modern flat roof composition is a built-up layered mat of tar paper, felt, etc., and asphalt or tar. Construction of such layered roofs is time-consuming and with recent increases in costs of petroleum products, has become quite expensive. Additionally, such layered roofs are difficult to provide with desired contours and slopes, are subject to deterioration from weathering, and have little thermal insulation benefits due to the great expense in constructing them thick enough to provide insulation.
It has been known in the art to provide a roofing compound, particularly as an insulating layer, as part of the roof. Such insulating layer compounds include both rigid insulation slabs or pads which are laid atop the roof base and thereafter covered with a standard laid up roof and wet or dry-type compounds which are poured or otherwise applied to the roof base and thereafter contoured to the desired roof contour. Such known arrangements include loose fill materials compacted by rollers or the like as well as insulating concrete materials which are poured and set.
Primarily such insulation compounds do not provide final roofing covers but rather are later covered with a standard laid up roof.
Other roofing structures include membrane roofs using plastic, rubber or pre-constructed lay-ups which are applied either with single layers or as multiple layers with or without overlying and/or underlying insulation.
A common feature of the majority of prior art insulating roof compounds is that they do not constitute a roofing surface but rather constitute merely a single layer of a multi-layer roofing surface. Moreover they are not weather resistant, and are expensive to obtain and install.
It would therefore be an improvement in the art to provide a roofing composition having high insulation properties which is capable of being directly applid to a roof base, being conformable to roof contours and desired slopes and which, when set, is capable of providing a final or finished roof.
SUMMARY OF THE INVENTION
It is therefore a principal object of this invention to provide an improved roofing composition.
It is another, and more specific object of this invention, to provide a roofing composition having high thermal insulation properties.
It is yet another, and more specific object of this invention, to provide a roofing composition which can be premixed remote from the building site, pumped or otherwise moved from a delivery truck to a roof, poured or screed into a desired roof contour and which will thereafter set to a film roof having weather resistant properties.
It is another, and more specific object of this invention, to provide a roofing composition which can be applied semi-moist, which will thereafter set to a uniform roof, which does not need a laid up or membrane roof overcoat, and which is weather resistant and has relatively high insulating properties.
It is another, and specific object of this invention, to provide a roofing composition composed of discrete pieces of foamed closed cell polyurethane or polystyrene resin, inexpensive inert powder or granular material such as fly ash, and an emulsion binder for the resin and ash ingredients which will set under atmospheric conditions to caulk and seal the pieces and particles.
This invention fulfills each of the above objects by providing a roofing composition composed of a mixture of chopped pieces of closed cell foamed plastics material, such as polystyrene or polyurethane, heavier inert particles of inexpensive filler material such as fly ash, and an emulsion binder which will set up under atmospheric conditions to bind together and seal the mixture into a water-proof weather-resisting layer. The composition may be pre-mixed remote from the use site, transported to the use site in a standard concrete mixer-type truck, and poured or pumped to the use site to form the weatherproof roof. The composition may be applied directly on top of the roof base of a building such as a metal deck, a concrete deck, precast concrete sections, precast concrete beams or channels, or other roof constructions. The composition can be applied over an under layer sealer such as a sheet or plastic coat or can be applied directly to the base. The composition is applied in a fully flowable condition and will conform with the roof contour. It is thin enough to fill cracks, gaps or undulating contours and can be screed or otherwise formed to the desired roof shape or slope. It can be built up at the edges and can be applied in any desired thickness. The composition exhibits good insulating capacity so that a sufficiently thick layer will avoid the necessity of using other external insulation for the building roof.
In a preferred embodiment water may be added to the compound to limit the agglomeration and to reduce stickiness.
Other objects, features, and advantages of the invention will be readily apparent from the following description of the preferred embodiments thereof, taken in conjunction with the accompanying drawings, although variations and modifications may be effected without departing from the spirit and scope of the novel concepts of the disclosure, and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a method of applying the roofing compound of this invention.
FIG. 2 is a fragmentary cross-sectional view of a roof portion of a structure roofed with the compound of this invention.
FIG. 3 is an enlarged fragmentary cross-sectional view of a roof formed from the compound of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The roofing composition of the present invention is preferably formed as a mixture of chopped pieces of closed cell foamed plastics material, fly ash, and an emulsion binder which sets up under atmospheric conditions to seal together the plastic pieces and fly ash particles into a weather-resisting water-proof layer or mat. The closed cell foamed plastics material may be a polystyrene, a polyurethane, or the like which can be economically obtained as a waste material from forming operations which use such plastics material in the manufacture of other items. For example, a large quantity of such material is presently available as waste from the forming of articles by trimming or cutting the articles from sheets of the material. This creates a large amount of waste scrap ideally suited for the plastics material component of the compositions of this invention.
The second ingredient, fly ash, is a standard waste material, readily available in large quantities from commercial power plants and the like. Being a waste commodity it is practically free in cost and being inert it combines with the plastics material to form the very desirable weather-resistant roof. The fly ash adds bulk and strength to the plastics material.
The third ingredient, is an emulsion binder forming a homogeneous mixture of the fly ash and the foamed plastics material and then setting under atmospheric conditions to caulk and seal the ingredients into a water-proof mat or layer. In general, water-based latex caulking compounds and sealants are useful and available under such trade names as "Rhoplex" Acrylic Emulsion for Aqueous Caulks and Sealants supplied by Rohm and Haas Company of Philadelphia, Pa., "Elvace" acetate/ethylene copolymer emulsion furnished by DuPont Company of Wilmington, Del. These emulsions can be latex based, of relatively high solids content (40-65%) of monomers such as styrenes, acrylic nitrites (particularly methyl acrylate), vinyl acetates, vinyl chlorides and the like latices. Such compositions will dry and set up under atmospheric conditions by cross-linking and polymerization, caulking and sealing together the plastics pieces and fly ash particles into a water-proof wear-resisting layer or mat.
The mixture of the three primary ingredients exhibit some surprising properties. First, the mixture remains fluid for sufficiently long periods of time to allow it to be mixed remote from the building site, trucked to the building site, and either poured or pumped onto the roof base. Due to the fluid nature of the mixture, it is easily spread and screed to the desired contours. Moreover, the mixture, again due to its fluid state, will evenly coat the roof irrespective of the roof underlayment. Thus, the mixture conforms to the roof surface, fills all gaps, cracks and undulations, can be screed to a desired slope, and yet is viscous enough so that it will not flow down high slopes. The composition can be built-up on arcuate curves at the edges of the roof, around window openings, or the like. Preferably, the foam plastics material is a closed cell polystyrene which has been modified to make it fire-resistant. Such modified polystyrenes are known in the trade and in general, the polystyrene has added to it, prior to the foaming, materials which will cause it to be self-extinguishing. One known method is to add chlorinated rubber to the polystyrene base. The particular modification of the plastics material to render it flame-resistant constitutes no part of my invention.
The composition of this invention, when set, accommodates hot and cold expansion or contraction as well as thermal expansion and contraction of the building. The set roofing composed of the composition of this invention is firm while retaining resiliency allowing it to be walked upon while its resiliency allows it to conform to building expansion and contraction.
Since the fly ash ingredient is completely inert and the polystyrene is substantially inert, the composition is weatherproof. Moreover, because the binder sets the ingredients into a firm layer or mat it will not lift from the roof in high winds.
A preferred mixture ratio of ingredients of the composition of this invention will be apparent from the following test batch:
approximately 21 cubic feet of 11/2 pound density chopped styrofoam (polystyrene) preferably chopped to particles or pieces having a maximum dimension equal to or less than 3/8 inch is mixed with 7.2 cubic feet (788 pounds) of fly ash. To this mixture 13 gallons (1.74 cubic feet) of an emulsion binder capable of caulking and sealing the styrofoam and fly ash into a water-proof mat under atmospheric conditions, is added. Suitable caulking-type binders and sealants for styrofoam plastics material are commercially available under the trademark "Elvace" (a trademark of DuPont Corporation, Wilmington, Del.) for acetate/ethylene emulsion, and "Rhoplex" (a trademark of Rohm and Haas Company, of Philadelphia, Pa.) for acrylic emulsions. In general, the binders are water-based or water-extended and set by polymerization and cross-linking under atmospheric conditions within a few hours. The term "copolymer emulsion binder" is used herein to designate such known caulking type binders and sealants which set under atmospheric conditions.
In a preferred embodiment, to the above mixture, may be added up to 34 gallons (4.5 cubic feet) of water to limit agglomeration and stickiness.
By volume, a desirable composition of this invention has about one part binder to four parts fly ash to twelve parts chopped styrofoam and to this may be added up to 2.5 parts of water.
A specific "copolymer emulsion binder" is an acrylic emulsion available from the Rohm and Haas Company under the name "Rhoplex LC-40" which is believed to be a copolymer of methacrylic acid esters having a chemical base as follows: ##STR1## wherein R 1 and R 2 are lower primary alcohols.
The mixture may be transported to the job site by a concrete mixer or the like truck and can thereafter be pumped to the roof through a standard concrete pump. Of course, the mixture can also be made on site if desired.
As a second example of a preferred mixture the following was prepared:
10 cubic feet of 11/2 pound density (per cubic foot) styrofoam fine chopped having a maximum length in any dimension of 3/8 inch; 10 cubic feet of 11/2 pound density (per cubic foot) styrofoam chopped coarse having a maximum length of 1/2 inch in any dimension; approximately 41/2 cubic feet (468 pounds) of fly ash; 13 gallons of acrylic copolymer; 3 gallons of a water reducing agent; 0.08 gallons of chlorinated rubber base; and a small amount of fungicide. To this was added up to 18 gallons of water to enhance the flowability of the mixture.
An acceptable water reducing agent may be volcanic ash. Acceptable chlorinated rubbers may be polymers of the type (C 10 H 11 Cl 7 )n. Polymers of this type are available from the Sherman Williams Paint Company of Chicago, Ill.
The preferred water reducing agent used in the above described second embodiment was a well known liquid accelerator for concrete sold under the trademark "Pozzolith" by Master Builders of Cleveland, Ohio, a division of the Martin-Marietta Company. These compositions are liquid admixtures of Pozzolanas obtainable from silicious material of volcanic origin, glass furnace slag, and the like. These materials react with lime in the presence of water to produce a cementatious compound. Addition of these agents allow the same flowability characteristics to be achieved with lesser amounts of water and reduce the set time and lighten the material being pumped. The chlorinated rubber was obtained from Rohm and Haas Corporation and is sold as chlorinated rubber base. It increases the fire resistance of the composition. The fungicide was added primarily because certain acrylic copolymer emulsion binders have a tendency to support micro-organisms.
After application and screeding the mixture is allowed to set. The build up of the mixture is both dependent upon the nature of the roof desired, the slope of the roof to be applied and the extent of insulation properties desired. The roof may, for example, be built up with from 2 to 6 inches of the mixture.
The resultant compound sets in approximately the same time as concrete and has been found to be firm enough to walk upon in 3 to 5 hours.
Although in the preferred mixture water has been used, the compound sets without use of water if desired. The compound does not exhibit hydration and, when properly set, is substantially water impervious.
Further, I have found that the appearance of the roof and its weather resistant properties can be enhanced by applying a final overcoat of the same acrylic emulsion used in the mix. The overcoat also aids in protecting the mixture. The binder emulsion, preferably an acrylic, when used as an overcoat, will exhibit sufficient resiliency to maintain coherence with the resilient roofing mixture. Specifically, I have found that even with the composition of the first above described specific example, the final overcoat can advantageously be an emulsion binder having added to it the chlorinated rubber base and fungicide described in connection with the second specific example. When using the final overcoat, it is preferable to delay application until substantially all of the water has evaporated from the roofing composition.
It is not necessary, when using the above roofing compound, to apply any further roofing. Specifically the necessity of using the heretofor used membrane or laid up roofing is eliminated.
As illustrated in the drawings, the roofing compound of this invention 10 consists of a substantially homogeneous mixture 11 of closed cell foamed plastic, fly ash, and emulsion binder. The mixture may be transported to the job site 12 by a concrete mixing truck 13 and thereafter pumped to the roof 15 by suitable means such as a standard concrete pump 16.
The roof is prepared for receipt of the mixture in any standard building manner. For example, a metal corrugated type roofing 18 may be utilized as a standard roof base. A preferred roofing deck is a G60 galvanized roof deck. Advantageously, the mixture disclosed herein will fill the grooves 19 of such corrugated roofing. Moreover, as shown in FIG. 2, the roofing may be built up to any desired level and can be sloped or tapered as shown at 20 to provide whatever contours are necessary for drainage or aesthetics. For example, the roof can be sloped upwardly at outside walls 21 and pitched to a central or peripheral drainage system.
As best shown in FIG. 3, the composition, when properly applied, will fully conform to the various contours of the base, filling all major cracks, roof joints, etc. The compound roof 11 may when desired, be provided with a final coat or seal skin 25 which preferably would consist of the same or a similar acrylic emulsion as is used for the mix binder.
I have provided a mixture according to the above formulation and I have found that the mixture can, if desired, be preformed into slabs, sheets or bricks. I have further found that the setting time is sufficiently prolonged as to allow transportation from a separate mixing site to a building site a distance substantially consistent with present day concrete practice. Moreover, I have found that the mixture, when premixed with water to prevent agglomeration and reduce stickiness, is not adversely effected by that water during the curing. Apparently the water evaporates out of the mixture at a rate which, although perhaps slightly slowing curing time, does not adversely effect the set of the mixture. The resultant composition, when fully set, in a brick of approximately 4 inch depth, has been tested to a compression resistance of 44 pounds per square inch with high resiliency at lower pressures.
It can therefore be seen from the above that my invention provides a new roofing composition which substantially eliminates many of the disadvantages of presently used roofing structures. Surprisingly, with a pourable roofing compound, I have been able to provide a roof structure which is weather resistant, of good insulating qualities, easily applied, quickly set and of sufficient strength and compression resistance to support normal roof activities while retaining adequate resiliency to compensate for building structure expansion and contraction.
In the above described preferred embodiment I have set forth specific examples. However, the relationship between materials disclosed in that example may be modified for different situations. Basically I believe that an acceptable roofing structure can be economically made anywhere within a range of, by volume, 50 to 70% foamed plastic material to 20 to 40% fly ash to 5-10% binder. The specific amount of emulsion binder to be utilized is dependent upon a number of factors, including the specific mixture of dry ingredients, the desired time to setting, the specifics of the emulsion binder used, and whether or not water is added. For example, with an acrylic emulsion having a smaller percentage of solids than that which I have used, a larger quantity of binder per cubic foot of dry ingredient may be desirable. To the above basic mixture water may be added.
The amount of water to be added is dependent upon environmental factors, the quantity and quality of the binder used, and the degree of flowability required.
Although the teachings of my invention have herein been discussed with reference to specific theories and embodiments, it is to be understood that these are by way of illustration only and that others may wish to utilize my invention in different designs or applications.
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A pourable roofing composition composed of chopped discrete small chunks or pieces of closed cell plastics material, such as polystyrene, polyurethane, and the like; inexpensive granular or powder particles of fly ash or the like inert particulate material which will hold down the light cellular plastic pieces; and an emulsion caulking or sealing type binder or adhesive capable of setting under atmospheric conditions to seal the composition into an all weather resisting waterproof layer. Suitable binders or adhesives are liquid based emulsions of acetates, acrylic resins, epoxy adhesives, and the like. The composition is flowable, can be premixed remote from the building or use site, can be transported to the site in a concrete mixer type truck, and can thereafter be spread over a roof base and screed to the desired contour and level. After an initial set, an overcoat of a sealer such as an acrylic resin-type sealer can be applied.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Section 371 of International Application No. PCT/EP2015/000236, filed Feb. 5, 2015, which was published in the German language on Aug. 13, 2015, under International Publication No. WO 2015/117759 A1 and the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to a plate apparatus suitable for heat and/or material exchange having a plurality of plates that contact each other flush along a peripheral seal while forming respective intermediate spaces and that have upper through-flow openings and lower through-flow openings for fluids, wherein a group of these upper and lower through-flow openings is allocated to at least two fluids to be mixed and is connected by correspondingly placed seals to every second plate intermediate space that carries a flow from top to bottom, and wherein in flush upper through-flow openings of the specified group a distribution lance runs across these openings and has outlet openings for at least one fluid.
To the extent the terms “seal” or “sealed” or the like are used here and in the following, these should be considered to relate not only to separate, standalone seals between adjacent plates, but also to include the material-joining connection of plates by welding or soldering—thus without additional sealing.
The invention is based on known plate heat exchangers, in which the through-flow openings are sealed relative to the plate intermediate spaces, such that every second plate intermediate space carries a flow of one fluid and the plate intermediate spaces lying therebetween carry a flow of the other fluid. As an example, DE 103 22 406 of the same applicant is referenced, whose content is incorporated herein by reference and is thus also included in the content of the present application. The theme of that application is the most uniform possible loading of the plate gap by the in-flowing medium. For that purpose, it is proposed to provide on the inflow side of the plate a plurality of inflow openings, which extend across the entire width of the plate and thus cause a more uniform loading of the plate gap across its width.
Consequently, there is also the need to load every second plate intermediate space with two different phases of a fluid, namely both with the liquid phase and also the gaseous phase. In this case, care must be taken, especially for the liquid phase, that a uniform distribution to the allocated plate intermediate spaces is ensured. For this purpose DE 1 269 144, from which the present application starts, proposes to arrange a distribution lance in the form of a spray tube in the upper through-flow openings. This spray tube has radially running spray openings, through which the fluid is supplied to plate intermediate spaces allocated to it while crossing the surrounding gas space. In this way, a thorough mixing of the liquid phase with the gas phase is produced before and in the plate intermediate space.
BRIEF SUMMARY OF THE INVENTION
The present invention is based on the object of further improving the thorough mixing of the two phases, in particular ensuring a wetting of the plate surface by the liquid phase across the entire plate width. Here, a large contact surface between both fluids should be created, so that not only physical reactions, in particular absorption processes, but also chemical reactions between the two fluids are promoted. As a result, the present invention should be suitable not only for the mixing and reaction of liquid and gaseous phases of the same medium, but also of different media. Not least of all, the invention should be distinguished by a compact and economical construction.
This object is achieved according to the invention, in that the outlet openings of the distribution lance are directed into those plate intermediate spaces that are arranged between the specified second plate intermediate spaces.
Thus, the outlet openings for the fluids to be mixed are not directed toward the allocated plate intermediate spaces, but instead toward the adjacent “incorrect” plate intermediate spaces. With respect to their area used for heat transfer, these adjacent plate intermediate spaces are blocked in the usual way by seals, that is, in terms of the essential part of the plate intermediate spaces with respect to the fluids to be mixed. Thus, the specified fluids can flow only into the upper edge region of the “incorrect” plate intermediate spaces, namely only up to the specified seal that runs, in general, a few millimeters to a few centimeters underneath the upper through-flow opening. In this way, the fluid mixture, especially its liquid phase, builds up above the specified seal until the fluid level rises to the lower edge of the through-flow openings lying above. Then the fluid can flow through these through-flow openings into the “correct” open plate intermediate space. The through-flow openings thus form, to some extent, a dam that builds up the fluid in the “incorrect” plate intermediate space, so that the fluid can overflow into the “correct” plate intermediate spaces allocated to it only when it reaches a sufficient fill quantity. This results in a pressure-less distribution of the fluid to the “correct” plate intermediate spaces and to an optimal thin-film wetting as it flows downward.
The use of the through-flow openings as dams has the result that the fluid is distributed optimally in the plate intermediate spaces, and indeed not only by wetting of the entire plate width, but also with respect to the uniform loading of the plate intermediate spaces following one after the other in the lance direction.
At the same time, it results in an enlargement of the contact surface between the two fluids, which significantly accelerates reactions between the two fluids. These reactions can be absorption processes, especially if one fluid exists in a liquid phase and the other fluid is in a gaseous phase; however, they could also be chemical reactions. In both cases, through heating or cooling media that flow through the adjacent plate intermediate spaces, heat can be supplied or dissipated depending on whether the process is an endothermic or exothermic process.
The plate apparatus according to the invention therefore opens up completely new application possibilities in physical and chemical process engineering.
It is also within the scope of the invention, however, especially for adiabatic processes, to shut down those plate intermediate spaces that typically carry a flow of a heating or cooling medium, and to use them just for forming the desired dams.
It is especially expedient if the outlet openings of the distribution lance are arranged directly in the plate intermediate spaces. Then, they do not have to run at an angle, but instead can be oriented in the radial direction, which significantly increases the accuracy and is especially also independent of the discharge speed of the fluid.
For better use of the damming function, it is expedient that the through-flow openings, in which the distribution lance runs, do not have the typical round contour, at least in the lower region, but instead have an approximately horizontal edge that runs significantly above its allocated seal and extends over at least approximately 60%, preferably at least approximately 75%, of the maximum width of the through-flow opening.
In addition, it is recommended that the plates underneath the through-flow openings surrounding the distribution lance have at least one significantly smaller discharge opening. This has the function that built-up fluid can still be discharged into the “correct” plate intermediate space, if the plate apparatus is no longer operating. The discharge openings therefore should be positioned in the lowest region directly over the seal surrounding the through-flow openings.
Because the distribution lance has a much smaller diameter than the through-flow openings surrounding it, it is recommended that it carries a flow of only the liquid phase, while the gas phase flows in the annular space surrounding the distribution lance. However, if both fluids are liquids, then it is recommended to feed the more viscous and/or heavier specific weight fluid to the distribution lance.
In the preferred use of the plate apparatus for the absorption of a refrigerant in the context of an absorption cooling unit or absorption heat pump, it is expedient to absorb refrigerant vapor by a liquid. Here, the adjacent plate intermediate spaces carry a flow of a coolant, which receives and dissipates the heat produced during the absorption.
In those use cases in which no exothermic or endothermic reactions take place in the plate apparatus, it is recommended that the plate intermediate spaces, that can be connected to a heating or cooling medium and are shut down in this case, contain spacers which ensure that the adjacent plate intermediate spaces carrying a flow of fluid do not buckle.
The spacers are expediently formed by wave profiles, which extend strip-shaped through the plate intermediate space to be supported.
Another expedient refinement of the invention consists in that the so-called second plate intermediate spaces, that is, those spaces where physical or chemical processes or reactions take place between multiple fluids, have a greater gap thickness than the adjacent plate intermediate spaces. The ratio of the gap thicknesses expediently lies between 1:1 and 1:2, depending on the different volume flows.
For further increasing the contact surface between the two fluids to be mixed with each other, it is recommended in one refinement of the invention to provide a wave-shaped running intermediate layer in the plate intermediate space allocated to the fluids, wherein this layer contacts at least one plate, preferably both plates, at its wave peaks and is perforated by a plurality of holes. In this way, the fluids are subjected to constant swirling and mixing while flowing down through the plate intermediate space. At the same time, this intermediate layer can function as a spacer, regardless of which pressure differences exist between adjacent plate intermediate spaces.
Preferred applications of the plate apparatus according to the invention are described below and in the claims. Here, the main advantage of the invention is that namely media whose viscosity is very different are mixed optimally in the plate intermediate spaces allocated to them, because the overflow dam produces a wide fluid distribution across the plate width already in the inflow area from the approximately point-wise fluid flow. In terms of energy it is especially beneficial that the distribution of the fluid having the higher viscosity to the individual plate gaps no longer has to be realized as before by high pressures and corresponding pressure losses in the distribution lance.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:
FIG. 1 is a plan view of one plate of the plate apparatus according to an embodiment of the invention;
FIG. 2 is an enlarged vertical section through multiple plates arranged one next to the other in an embodiment of the invention;
FIG. 3 is a cross section along the line III-III in FIG. 2 ;
FIG. 4 is a horizontal section through some adjacent plates according to an embodiment of the invention;
FIG. 5 is a perspective view of a plate apparatus according to an embodiment of the invention; and
FIG. 6 is a schematic absorption circuit illustrating the use of a plate apparatus according to an embodiment of the invention as an absorption cooling unit.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a plan view of a plate P 1 of a conventional plate heat exchanger. It has on its outer periphery a peripheral edge seal 1 and at its four corner regions the four typical through-flow openings 2 , 3 , 4 and 5 . Here, two upper/lower opposing through-flow openings—here the through-flow openings 2 and 5 —are blocked by sealing rings 2 a and 5 a relative to the visible heat transfer surface of the plate, while the two other through-flow openings 3 and 4 opposite them are open, so that the fluid flowing into these through-flow openings can wet the visible plate surface, as is indicated by the illustrated arrows. The visible plate side thus belongs to a plate intermediate space Z 0 or Z 2 in FIG. 2 , which typically carries a flow of a heating or cooling agent.
Behind the shown plate P 1 , however, there is an intermediate space Z 1 or Z 3 (see FIG. 2 ) that is allocated to the fluids to be mixed. Therefore, the through-flow openings 3 and 4 are surrounded there by seals, while the seals 2 a and 5 a are missing on the back side of the shown plate.
It can also be seen in FIGS. 1 and 2 that a distribution lance 6 having a significantly smaller diameter is arranged in the upper through-flow openings 2 . This distribution lance 6 runs, as FIG. 2 shows, axially through the through-flow openings 2 of adjacent plates P 0 , P 1 , P 2 , P 3 , P 4 . In those plate intermediate spaces that are not allocated to the fluids to be mixed, that is, in the “incorrect” plate intermediate spaces Z 0 and Z 2 , the distribution lance 6 has downward projecting outlet openings 6 a.
During the operation of plate heat exchangers the through-flow openings 2 carry a flow of a first fluid, usually a gas, and the distribution lance 6 carries a flow of a second fluid, in general a liquid. While the distribution of the gaseous first fluid takes place without a problem to the correct plate intermediate spaces, the liquid fluid is fed by means of the distribution lance 6 first to the “incorrect” plate intermediate spaces Z 0 , Z 2 , in which the through-flow openings 2 are surrounded by the specified seals 2 a . Thus, these “incorrect” plate intermediate spaces fill up with fluid until the lower edge of the through-flow openings 2 is reached. This state is shown in FIGS. 2 and 3 .
With further supply of fluid, the plate areas within the seal 2 a act as dams over which the fluid flows as a thin film on both sides downward into the “correct” plate gaps. Here, the lower edges of the through-flow openings 2 are formed by straight, horizontally running edge sections 2 b , so that the overflow already begins with a certain width. The edge sections 2 b here run at a level that preferably lies above half the distance between the lower edge of the seal 2 a on one side and the distribution lance 6 on the other side.
For very large plate assemblies having long distribution lances 6 , it can be expedient to increase the cross section of the outlet openings 6 a with increasing distance from the fluid entrance. This achieves a more uniform distribution of the fluid onto the plate intermediate spaces following one after the other.
FIG. 4 shows a horizontal section area through multiple plates. Here, spaces 7 and 8 in the form of corrugated inserts are arranged in the plate intermediate spaces. The spacers are dimensioned so that they contact both adjacent plates and thus create a support of the plates perpendicular to the plane of the plates. This arrangement prevents buckling of the plates when there are high differential pressures between adjacent plate intermediate spaces.
Here, the spacers that are arranged in those plate intermediate spaces that carry a flow of fluids to be mixed—in the embodiment the spacer 7 —are provided with a plurality of openings 7 a . In this way, the fluids pass through the spacer 7 , which promotes their mixing.
FIG. 4 also shows that the plate intermediate spaces—differently than as shown in FIG. 3 —can have different gap dimensions. In particular, the plate gaps carrying the flow of the fluids to be mixed can have a greater gap width than the plate gap that carries a flow of heating or cooling agent or is shut down.
FIG. 5 shows a perspective view of a complete plate apparatus for use in an absorption process. Here, as in FIG. 1 , the feeding of the gaseous or vaporous working medium and the solvent to be mixed with it is provided in the left upper region. While the solvent is fed to the distribution lance 6 , the supply of the working medium is realized via a pipe elbow 16 . The distribution lance 6 that runs in the interior of the plate holes 2 is sealed relative to the pipe elbow 16 and crosses through it at a suitable position. In this way, the working medium and the solvent can be fed separately and the mixture of both fluids begins only directly above the plates.
At the left lower edge, the solution enriched with working medium is discharged from the plate apparatus at a pipe connection 17 .
Connection nozzles 18 and 19 are allocated to the through-flow openings 3 and 4 in FIG. 1 and are used for the supply and discharge, respectively, of cooling water that receives the heat released during the absorption process.
FIG. 6 shows the preferred application of the plate apparatus in the context of an absorption process—in the shown embodiment in an absorption cooling unit, but the use is equally expedient in an absorption heat pump.
The function of absorption cooling units or heat pumps is known prior art and therefore will not be described in detail. What is essential in the present context is the construction of the absorber, which is marked in FIG. 6 by the reference symbol “A”. A suitable working medium in a gaseous or vaporous consistency is fed to the absorber. This working medium is to be mixed with a solvent, so that an absorption process is produced between the two fluids. For this purpose, the solvent, which usually has a relatively viscous consistency, is fed to the distribution lance 6 , while the gaseous or vaporous working medium is fed into the space surrounding the distribution lance. The mixing of the two fluids is then performed in the so-called second plate intermediate spaces, wherein a large reaction surface between the working medium and the solvent is provided by the fluid distribution across the width of the plate intermediate spaces. In this way, while crossing through the plate intermediate spaces, a strong absorption of the working medium by the solvent is produced, and after flowing through the plate intermediate spaces, the solvent is strongly enriched with working medium, when it leaves the plate intermediate space at the lower end.
The processing heat Q A released during the absorption process is received and dissipated by a fluid flowing in the specified first plate intermediate spaces.
In the present application the use was described in connection with an absorption process. However, it is equally within the scope of the invention to use the plate apparatus for chemical reactions, in which different media are to be mixed within one plate gap.
It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.
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A plate apparatus suitable for heat and/or material exchange has plates (P 0 , P 1 , P 2 , P 3 ) contacting each other flush along a peripheral seal ( 1 ) while forming respective intermediate spaces (Z 0 , Z 1 , Z 2 , Z 3 ) and having upper ( 2, 3 ) and lower ( 4, 5 ) through-flow openings for fluids. A group of these upper and lower through-flow openings ( 2, 5 ) is allocated to at least two fluids and is connected by correspondingly placed seals to every second plate intermediate space (Z 1 , Z 3 ) carrying a flow from top to bottom. In flush upper through-flow openings ( 2 ) of plates (P 0 , P 1 , P 2 , P 3 ) a distribution lance ( 6 ) runs across these openings and has outlet openings ( 6 a ) for at least one of the fluids. It is essential that the outlet openings ( 6 a ) are directed into those plate intermediate spaces (Z 0 , Z 2 ) arranged between the second plate intermediate spaces (Z 1 , Z 3 ) for the fluids to be mixed.
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FIELD OF THE INVENTION
This invention relates to a paper strength enhancing resin that is fluorescent.
BACKGROUND OF THE INVENTION
The addition of an amine across an activated aliphatic double bond is often called the Michael addition reaction, and this reaction can produce linear aminoacids or linear aminoesters. This reaction is shown in British Patent 1,256,804, U.S. Pat. No. 3,445,551 and U.S. Pat. No. 4,517,122. In the Bull. Chem. Soc. Jap. vol. 41, 1968, pages 256 to 259 it is reported that a linear aminoester had a molecular weight of 1000 and had a greenish yellow fluorescence. Japanese Patent No. SHO 44 [1969] 27907 reports that copolymers of linear aminoacids (containing polymerization control agents) with amines are subsequently reacted with epihalohydrin to produce a polymer resin that is useful to enhance the strength of both dry and wet paper.
SUMMARY OF THE INVENTION
This invention is a fluorescent resin having the formula: ##STR2## where each R is independently selected from the group consisting of methyl and hydrogen, X is a halogen selected from the group consisting of Cl, Br and I, and n is the integer 8 or a larger integer. Because the greatest known utility for these polymers is a strength enhancer for paper, n must be an integer small enough that the resin is water soluble; thus n should be smaller than about 50. The fluorescent property of the resin makes it particularly attractive as a paper additive in that it brightens and appears to whiten the paper, while common resins added to paper tend to yellow the paper and require the addition of brighteners and/or bleaches to bring them to the brightness level that is often desired.
DETAILED DESCRIPTION
In order to produce the resin of the invention certain important process parameters must be observed. The polymerization of the Michael addition product must be controlled such that the temperature does not exceed 165° C. A suitable range is 135° to 165° C. and it is preferable to operate at a temperature greater than 145° C. At temperatures above 165° C., the resin prepared is not fluorescent. The pressure should be 50 to 200 mm of Hg vacuum in order to achieve the molecular weight necessary to be useful as a paper strength enhancing agent--a weight average molecular weight of at least 1200. The reaction of this polymer with epihalohydrin to form the polymer of the invention should be carried out at a temperature in the range of 60° to 80° C. The amount of epihalohydrin employed should be about stoichiometrically equivalent to the number of ═NH groups in the polymer, that is, the ratio of epihalohydrin to =NH should be in the range of about 0.8-1.5/1. Preferably, the epihalohydrin is added in a slight excess over the number of secondary amine groups, that is, in a mole ratio of 1.2-1.4 moles per mole of secondary amine groups.
After reaction of the epihalohydrin, in order to complete the paper strength enhancing composition, the pH is adjusted to 3-5, preferably 4-4.5 by the addition of an inorganic acid such as sulfuric acid, and the concentration of the resin adjusted so that the amount of resin is about 10 to 35% by weight of the aqueous mixture, preferably 25-35%.
The fluorescent resin may be added to paper pulp during manufacture of paper at levels of 0.5 to 1.0 wt. % based on the wt of the pulp. The resin may also be coated on the surface of the paper with a size press. The resin is cured in the standard fashion, typically in the dryer section of the paper machine.
The use of the resin of the invention allows paper to be fluorescently tagged, making it easier to inventory, track and control paper in commerce.
Suitable amines useful in the preparation of the Michael addition products have the formula: ##STR3## where R 1 and R 2 are independently selected from H, CH 3 .
Suitable compounds having an activated aliphatic double bond useful in the preparation of the Michael addition products have the formula: ##STR4## where R is selected from CH 3 , C 2 H 5 , C 3 H 7 , and C 4 H 9 and R 3 is selected from H, CH 3 .
Suitable epihalohydrins useful in forming the polymers of the invention are epichlorohydrin, epibromohydrin and epiiodohydrin.
The Michael addition reaction can be carried out in a solvent such as tetrahydrofuran, or in the absence of a solvent.
TEST PROCEDURE FOR WET AND DRY STRENGTH
An aqueous solution of 1.0% resin is applied by size press application to bleached kraft paper and then dried. 4 inch×1 inch specimens of treated paper were re-wetted in distilled water by soaking 1 hr, lightly blotted to absorb excess water and then tested in a tensile strength instrument. Wet strength is reported in pounds required to break the test sample per inch of sample width. Dry strength is similarly measured for a treated sample that has not been re-wetted. A wet-to-dry strength ratio is also reported as percent.
FLUORESCENCE SPECTROSCOPY
Fluorescence emission spectra of solution samples and treated paper samples are reported as emission maxima for 300 nm excitation with relative intensities scaled vs. a zero standard.
MOLECULAR WEIGHT DETERMINATION
Molecular weights were determined in cresol by gel-permeation chromatography using nylon-6,6 molecular weight standards for comparison. M n =number average molecular weight, M w =weight average molecular weight, and D means dispersity and is the ratio M w M n .
EXAMPLES
EXAMPLE 1
34.4 g of methyl acrylate is slowly added to stirred ethylenediamine (24.0 g), keeping T<45° C. by adjusting the addition rate. Product was 56.6 g (96.8%) of linear monomer (by IR and GC-MS) which contained minor amounts of bis-adduct.
43.9 g of this monomer was heated neat to >135° C., using a water aspirator and simple still head to remove methanol formed by the polymerization. The pot thermometer broke during the run so that the final run temperature is not known. (Because the thermometer broke and the final temperature is unknown, this portion of this example was later repeated as follows:
43.9 g of the monomer was stirred under N 2 . Water aspirator vacuum was applied. Monomer was heated 15 minutes at 150° C., 70-80 mm Hg and 30 minutes at 160° C., 70-80 mm Hg. 11.2 g of distillate were collected during polymerization from the simple still. Polymer was cooled to 100° C., 80 ml of water added and the mixture stirred at 50° C. until dissolution was complete. 106.8 g of 25% solids polymer solution was obtained. M n =1100, M w =1300, D=1.2.)
Viscous polymer was cooled to <100° C. and 80 ml deionized water added to dissolve the product. 6.7 g of distillate were collected and 91.7 g of a 30.3% solids polymer solution was recovered. The polymer had the following properties:
M n =1000, M w =1220, D=1.22.
Fluorescence emission data: Polyamide solution
λmax=400-410 nm (blue, 300 nm excitation),
Intensity=40,000 (vs. 0 for standard).
50 g of this product (30.3% solids; 0.133 mole of secondary amine groups) was mixed with 50 g of deionized water and stirred under N 2 at 40° C. 13.9 g of epichlorohydrin (0.14 mole) was dripped in over 15 minutes and then the mixture was heated 1 hr at 75° C. The solution was cooled to room temperature and the pH adjusted from 6.5 to 4.6 with 0.4 ml concentrated H 2 SO 4 . 42.9 g of a 25.5% solids solution of the resin was obtained. M n =1580; M w =2410; D=1.53
Fluorescent emission was virtually identical to that of the polyamide.
TABLE 1______________________________________COMPARATIVE STRENGTH DATA lbs/in lbs/in % Av. Wet Av. Dry Wet/Dry______________________________________Resin of this Example 8.6 45.2 19Commercial polyamide- 13.0 48.4 27epichlorohydrin resin______________________________________
TABLE 2______________________________________COMPARATIVE FLUORESCENCE DATAFor bleached kraft paper, 300 nm excitation.Emission wavelength listed. Relative λ max., nm Intensity______________________________________Resin of this Example 400-410 32000 (tails to green)Commercial 340*-due 16000resin to polyamide absorptionControl, No Emission 0No resin______________________________________ *Not a visible emission, also observed in the resin of this Example.
EXAMPLE 2
Michael addition reaction was carried out in the manner similar to that described in example 1 using ethylenediamine and methyl methacrylate followed by polymerization. The resulting fluorescent polymer gave an emission maximum (300 nm excitation) of 530 nm (green).
EXAMPLE 3
A Michael addition reaction was carried out in a manner similar to that described in example 1 using 1,2-propanediamine and methyl acrylate followed by polymerization. The resulting fluorescent polymer gave an emission maximum (300 nm excitation) of 545 nm (yellow).
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A fluorescent resin suitable for use as a paper strength enhancing additive having the formula: ##STR1## where each R is independently selected from the class consisting of methyl and hydrogen, X is a halogen selected from the group consisting of Cl, Br and I, and n is the integer 8 or a larger integer.
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BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to a magnetic head having a confined current path, and more specifically, to a ballistic magneto resistive (BMR) sensor having a free layer stabilized by an in-stack bias and spacer-decoupling layer including nanoparticles.
2. Related Art
In the related art magnetic recording technology such as hard disk drives, a head is equipped with a reader and a writer that operate independently of one another. FIGS. 1 ( a ) and ( b ) illustrate related art magnetic recording schemes. A recording medium 1 having a plurality of bits 3 and a track width 5 has a magnetization 7 parallel to the plane of the recording media. As a result, a magnetic flux is generated at the boundaries between the bits 3 . This is commonly referred to as “longitudinal magnetic recording”.
Information is written to the recording medium 1 by an inductive write element 9 , and data is read from the recording medium 1 by a read element 11 . Coils 16 are used to supply a write current 17 to the inductive write element 9 , and a read current 15 is supplied to the read element 11 . An insulating layer (not illustrated for the sake of clarity) made of Al 2 O 3 or the like is deposited between the read element 11 and the write element 9 to avoid any interference between the respective read and write signals.
The read element 11 is a sensor that operates by sensing the resistance change as the sensor magnetization changes direction. A shield 13 reduces the undesirable magnetic fields coming from the media and prevents the undesired flux of adjacent bits from interfering with the one of the bits 3 that is currently being read by the read element 11 .
Due to requirements of increased bit and track density readable at a higher efficiency and speed, the related art magnetic recording scheme of FIG. 1( b ) has been developed. In this related art scheme, the direction of magnetization 19 of the recording medium 1 is perpendicular to the plane of the recording medium 1 . This is also known as “perpendicular magnetic recording”. This design provides more compact and stable recorded data. Also a soft underlayer (not illustrated) is required to increase the writer magnetic field efficiency. Further, an intermediate layer (not illustrated for the sake of clarity) can be used to control the exchange coupling between the recording layer 1 and soft underlayer.
FIGS. 2( a )-( c ) illustrate various related art read heads for the above-described magnetic recording scheme, known as “spin valves”. In the bottom type spin valve illustrated in FIG. 2( a ), a free layer 21 operates as a read sensor to read the recorded data from the recording medium 1 . A spacer 23 is positioned between the free layer 21 and a composed pinned layer 25 . On the other side of the composed pinned layer 25 , there is an anti-ferromagnetic (AFM) layer 27 . In the top type spin valve illustrated in FIG. 2( b ), the position of the layers is reversed.
FIG. 2( c ) illustrates a related art dual type spin valve. Layers 21 through 25 are substantially the same as described above with respect to FIGS. 2( a )-( b ). However, an additional spacer 29 is provided on the other side of the free layer 21 , upon which a second pinned layer 31 and a second AFM layer 33 are positioned. An extra signal provided by the second pinned layer 31 increases the resistance change ΔR.
The direction of magnetization in the pinned layer 25 is substantially fixed, whereas the direction of magnetization in the free layer 21 can be changed, for example (but not by of limitation) depending on the effect of an external magnetic field, such as the recording medium 1 .
When the external magnetic field is applied to a reader, the magnetization of the free layer 21 is altered, or rotated, by an angle. When the flux is positive the magnetization direction of the free layer 21 is rotated upward, and when the flux is negative the magnetization direction of the free layer 21 is rotated downward. If the applied external field changes the free layer 21 magnetization direction to be aligned in the same way as composed pinned layer 25 , then the resistance between the layers is low, and electrons can more easily migrate between those layers 21 , 25 .
However, when the free layer 21 has a magnetization direction opposite to that of the composed pinned layer 25 , the resistance between the layers is high. This high resistance occurs because it is more difficult for electrons to migrate between the layers 21 , 25 . Similar to the external field, the AFM layer 27 provides an exchange coupling and keeps the magnetization of composed pinned layer 25 substantially fixed.
The resistance change ΔR when the layers 21 , 25 are parallel and anti-parallel should be high to have a highly sensitive reader. The media bit is decreasing in size, and the correspondingly, the magnetic field from the media bit is weaker. As a result, it is necessary for the free layer to sense this media flux having a reduced magnitude. Therefore, it is important for the related art free layer to have a reduced thickness to maintain sufficient sensitivity of the free layer. In order to provide a high-sensitivity sensor that can sense a very weak magnetic field, this is accomplished by reducing the free layer thickness to about 3 nm in the case of an areal recording density of 150 to 200 Gbits/in 2 .
However, as a result of the thin free layer, there is a related art problem of a stronger spin transfer effect. The spin transfer effect is substantially inversely proportional to the thickness of the film. Thus, the stability of the free layer is reduced. Further, there is also a need for a high resistance change ΔR between the layers 21 , 25 of the related art read head. As discussed in greater detail below, a thicker free layer results in a higher value of ΔR.
The operation of the related art read head is now described in greater detail. In the recording media 1 , flux is generated based on polarity of adjacent bits in the case of longitudinal magnetic recording. If two adjoining bits have negative polarity at their boundary the flux will be negative. On the other hand, if both of the bits have positive polarity at the boundary the flux will be positive. The magnitude of flux determines the angle of magnetization between the free layer and the pinned layer.
FIG. 3 illustrates a related art synthetic spin valve. The free layer 21 , the spacer 23 and the AFM layer 27 are substantially the same as described above. However, the composed pinned layer 25 further includes a first pinned sublayer 35 separated from a second pinned sublayer 39 by a pinned layer spacer 37 . The first pinned sublayer 35 operates according to the above-described principle with respect to the composed pinned layer 25 . The second pinned sublayer 39 has an opposite spin state with respect to the first pinned sublayer 35 . As a result, the total composed pinned layer magnetic moment is reduced due to anti-ferromagnetic coupling between the first pinned sublayer 35 and the second pinned sublayer 39 . The synthetic read head has a composed pinned layer with a total magnetic flux close to zero, and thus greater stability and high pinning field can be achieved than with the single pinned layer structure. A buffer layer 28 is deposited below the AFM layer 27 for good spin-valve growth, and a cap 40 is provided on an upper surface of the free layer 21 .
FIG. 4 illustrates the related art shielded read head. As noted above, it is important to avoid the sensing of unintended magnetic flux from adjacent bits during the reading of a given bit. A cap (protective) layer 40 is provided on an upper surface of the free layer 21 to protect the spin valve against oxidation before deposition of top shield 43 , by electroplating in a separated system. Similarly, a bottom shield 45 is provided on a lower surface of the buffer layer 28 .
Related art magnetic recording schemes use a current perpendicular to plane (CPP) head, where the sensing current flows perpendicular to the spin valve plane. As a result, the size of the read head can be reduced without a loss of the output read signal. Various related art spin valves that operate in the CPP scheme are illustrated in FIGS. 5( a )-( c ), and are discussed in greater detail below. These spin-valves structurally differ primarily in the composition of their spacer 23 . The compositions and resulting difference in operation of these effects is discussed in greater detail below.
FIG. 5( a ) illustrates a related art tunneling magnetoresistive (TMR) head for the CPP scheme. In the TMR head, the spacer 23 acts as an insulator, or tunnel barrier layer. Thus, in the case of a very thin barrier that is the spacer 23 , the electrons can migrate from free layer 21 to pinned layer 25 or verse versa without change of spin direction. Current related art TMR heads have an increased magnetoresistance (MR) on the order of about 30-50%.
FIG. 5( b ) illustrates a related art CPP-GMR head. In this case, the spacer 23 acts as a conductor. In the related art CPP-GMR head, there is a need for a large resistance change ΔR, and a moderate element resistance for having a high frequency response. A low free layer coercivity is also required so that a small media field can be detected. The pinning field should also have a high strength. Additional details of the CPP-GMR head are discussed in greater detail below.
FIG. 5( c ) illustrates the related art ballistic magnetoresistance (BMR) head. In the spacer 23 , which operates as an insulator, a ferromagnetic region 47 connects the pinned layer 25 to the free layer 21 . The area of contact is on the order of a few nanometers. This is referred to as a nano-path or a nano-contact. As a result, there is a substantially high MR, due to electrons scattering at the domain wall created within this nanocontact. Other factors include the spin polarization of the ferromagnets, and the structure of the domain that is in nano-contact with the BMR head.
In the foregoing related art heads, the spacer 23 of the spin valve is an insulator for TMR, a conductor for GMR, and an insulator having a magnetic nano-contact for BMR. While related art TMR spacers are generally made of insulating materials such as alumina, related art GMR spacers are generally made of conductive metals, such as copper.
In the related art GMR head, resistance is minimized when the magnetization directions (or spin states) of the free layer 21 and the pinned layer 25 are parallel and is maximized when the magnetization directions are opposite As noted above, the free layer 21 has a magnetization of which the direction can be changed. Thus, the GMR system avoids perturbation of the head output signal by minimizing the undesired switching of the pinned layer magnetization.
GMR depends on the degree of spin polarization of the pinned and free layers, and the angle between their respective magnetizations. Spin polarization depends on the difference between the spin state (up or down) in each of the free and pinned layers. As the free layer 21 receives the flux from the magnetic recording media, the free layer magnetization rotates by a small angle in one direction or the other, depending on the direction of flux. The change in resistance between the pinned layer 25 and the free layer 21 is proportional to angle between the moments of the free layer 21 and the pinned layer 25 , as noted above. There is a relationship between the resistance change ΔR and the output read signal.
The GMR head has various requirements. For example, but not by way of limitation, a large resistance change ΔR is required to generate a high output signal. In order to generate the large resistance change ΔR, it is desirable to have thicker free layer. This relationship is shown in FIG. 6( a ). A similar relationship exists between the MR ratio and free layer thickness, as shown in FIG. 6( b ). Therefore, the thinner free layer, which is required to sense a smaller media bit with a weaker signal, also has a lower MR and AΔR in the related art CPP scheme. As a result, the related art spin transfer effect problem is increased.
As noted above, further increasing capacity of disk drives requires a small, high-sensitivity MR head that corresponds to the miniaturization of the head size. As head size decreases, the head output signal decreases. Accordingly, the free layer must be more sensitive to the media magnetic field. As discussed in S. Z. Hua et al., Phys. Review B67, 060401 (R) (2003), a high resistance change ΔR can be obtained using the foregoing related BMR concept (i.e., connection of at least two ferromagnetic layers to one another via a nano-contact). A substantially high BMR value can be achieved (e.g., thousands of percent of MR ratio).
The basis of the above-described BMR is disclosed in G. Tatara et al., Phys. Review Letters, Vol. 83, 2030 (1999), based on the thin domain wall between the two adjacent ferromagnetic layers that are antiparallel to each other.
In the related art BMR head, a key factor is the magnetic domain structure. Its configuration control and stability during the read process are extremely important for high-out put signal t. Further, for proper use of the BMR head, it is necessary to stabilize the free layer against thermal agitation and spin transfer effect and make it mono-domain.
Stabilization of the free layer in the related art has been done in the case of CPP-GMR, via an in-stack bias. This configuration is disclosed in U.S. Patent Publication No. 2004/0008454. In this related art in-stack bias, a decoupling layer is formed as a spacer above the free layer. The decoupling layer is made of a continuous conductive film having a thickness of 1 nm to 2 nm. The film may be made of a metal such as Cr, Ta or Cu.
Additionally, Japanese Patent Application Publication No. 10-229013 discloses a magneto-resistive effect element with an in-stack bias. More specifically, a bias film having a structure such that it can stabilize the free layer in mono-domain magnetic structure.
SUMMARY OF THE INVENTION
It is an object of the present invention to overcome the related art problems and disadvantages. However, such an object, or any object, need not be achieved in the present invention.
To achieve the above objects, a magnetic element including a spin valve is provided for reading a recording medium, and includes a free layer having a magnetization adjustable in response to an external field, a pinned layer having a substantially fixed magnetization, a spacer sandwiched between the pinned layer and the free layer, the spacer comprising a non-magnetic insulating matrix and a magnetic grain disposed therein to form nano-contacts, and an in-stack bias positioned on the free layer opposite the spacer, wherein the in-stack bias comprises a ferromagnetic layer pinned by exchange coupling with a first antiferromagnetic (AFM) layer, and an in-stack bias spacer including a magnetic grain disposed in an insulating matrix. The foregoing may also be implemented in a device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1( a ) and ( b ) illustrates a related art magnetic recording scheme having in-plane and perpendicular-to-plane magnetization, respectively;
FIGS. 2( a )-( c ) illustrate related art bottom, top and dual type spin valves;
FIG. 3 illustrates a related art synthetic spin valve for a magnetoresistive reader head;
FIG. 4 illustrates a related art synthetic spin valve having a shielded structure;
FIGS. 5( a )-( c ) illustrates various related art magnetic reader spin valve systems;
FIGS. 6( a )-( b ) illustrate the dependence of AΔR and MR, respectively on free layer thickness;
FIG. 7 illustrates magneto-resistive element according to a first exemplary, non-limiting embodiment of the present invention;
FIG. 8 illustrates magneto-resistive element according to a second exemplary, non-limiting embodiment of the present invention;
FIG. 9 illustrates magneto-resistive element according to a third exemplary, non-limiting embodiment of the present invention;
FIG. 10 illustrates magneto-resistive element according to a fourth exemplary, non-limiting embodiment of the present invention; and
FIG. 11 illustrates magneto-resistive element according to a fifth exemplary, non-limiting embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention includes an in-stack biased (also referred to as “exchange biased”) magnetic head having a confined current path according to the exemplary, non-limiting embodiments described herein, and equivalents thereof as would be known by one of ordinary skill in the art.
In the present invention, the term “read head” is used interchangeably with the term “magnetic sensor”, and refers to the overall apparatus for sensing data from a recording media. In this regard, “magnetic sensor” is one particular type of “magnetic element”, and where magnetic sensors are used in the specification, other magnetic elements (e.g., random access memory or the like) may be substituted therein, as would be known by one of ordinary skill in the art.
Additionally, the term “magnetic element” is defined to include “magnetoresistance effect element” and/or “magnetoresistance element” as is understand by those of ordinary skill in this technical field. However, the present invention is not limited thereto, and other definitions as would be understood by those of ordinary skill in the art may be substituted therefore without narrowing the scope of the invention. Further, the term “spin valve” is used to refer to the specific structural makeup of the read head layers.
FIG. 7 illustrates a BMR sensor (also referred to as a “magnetic sensor”) according to a first exemplary, non-limiting embodiment of the present invention. In this embodiment, a shield 101 is provided (preferably made of NiFe, but not limited thereto), upon which a buffer 103 is positioned. The buffer 103 is for good growth of an AFM layer 105 and the other films that are deposited on the buffer 103 .
The AFM layer 105 provides a coupling for a pinned layer 107 having a substantially fixed magnetization direction, which is positioned above the AFM layer 105 . The pinned layer 107 is preferably of a composed type, although another equivalent thereof, as would be known by one of ordinary skill in the art (e.g., single layer) may also be used. The composed pinned layer 107 includes a first pinned sublayer 109 spaced apart from a second pinned sublayer 113 by a non-magnetic pinned layer spacer 111 . For example, but not by way of limitation, these first and second pinned sublayers 109 , 111 may be ferromagnetic.
A spacer 115 is positioned between the pinned layer 107 and a free layer 117 . The spacer 115 is a film having nano-contacts 116 disposed in a non-magnetic insulating matrix (e.g., a nano-contact is made of a magnetic grains in an insulating matrix). At least one of the grains reaches both surfaces of the free layer and the pinned layer. The nano-contact is one or more grains. Preferably, only a substantially few grains for each nano-contact is preferred.
The free layer 117 is provided above the spacer 115 . As is the case in the related art, the magnetization direction of the free layer can rotate or switch in response to an external magnetic field. The magnetization direction is adjustable by the magnetic field. For example, but not by way of limitation, the external field may be generated from a medium such as a hard disk, and the pinned layer has a substantially fixed magnetization direction.
An in-stack bias 119 is positioned above the free layer 117 opposite to the spacer 115 . The in-stack bias 119 includes an in-stack bias spacer 120 positioned between the free layer 117 and a ferromagnetic layer 123 . The in-stack bias spacer 120 includes a second nano-contact 121 disposed in a non-magnetic insulating matrix 122 .
Another AFM layer 125 is provided above the ferromagnetic layer 123 to substantially (i.e., except for external magnetization effects, such as “noise” from the device in which the present invention is applied) fix its magnetization direction and to form the upper portion of the in-stack bias 119 . The magnetization direction of the ferromagnetic layer 123 is pinned by exchange coupling with the AFM layer 125 . Atop shield 127 is provided above the in-stack bias 119 , and an insulator 129 is provided between the top and bottom shields 101 , 127 , respectively, and on outside of the BMR sensor ( 103 through 125 ). A capping layer 126 is deposited on the top of the AFM layer 125 to protect the spin-valve stack against oxidation before top shield deposition.
In the foregoing exemplary, non-limiting embodiment of the present invention, the film structure of the in-stack bias 119 includes the in-stack bias spacer 120 which minimizes the exchange coupling between the free layer 117 and the ferromagnetic layer 123 , thus stabilizing the free layer 117 in the mondomain structure by magnetostatic coupling with the ferromagnetic layer 123 . Additionally, the current flows through the smaller space of the second nano-contacts 121 , such that the effective area A is reduced, the ΔR is increased. Further, the MR ratio increases, resulting in additional ballistic magnetoresistive effect due to the creation of a domain wall within the magnetic nano-contact of the in-stack bias spacer 120 .
As noted above, the pinned layer 107 can be a single ferromagnetic pinned layer or composed pinned layer. The composed pinned layer comprises the first pinned sublayer 109 and the second pinned sublayer 113 . The magnetizations of these sublayers 109 and 113 are coupled antiferromagnetically to each other. The first and second pinned sublayers 109 , 113 comprise a ferromagnetic material. A pinned layer spacer 111 is positioned between the layer 109 and the layer 113 . The ferromagnetic material in the pinned layer 107 comprises one of Fe, Ni and Co. The pinned layer 107 has a total thickness between about 3 nm and 8 nm. The non-magnetic pinned layer spacer 111 is made of at least one of Ru, Rh, Pd, Pt, Ir, Os, Ag and Cu, or alloys thereof, and has a thickness between about 0.3 nm and 1 nm.
In the foregoing embodiment, the pinned layer 107 magnetization is disclosed to be pinned by the AFM layer 105 . However, the present invention is not limited thereto, and alternative structures may be used, as would be understood by one of ordinary skill in the art. For example, but not by way of limitation, instead of being substantially fixed by the AFM layer 105 , the pinned layer 107 may be self-pinned by a hard magnetic layer.
In the present invention, the sensing current flows in the film thickness direction (e.g., from the bottom shield to the top shield or the opposite direction). This is called Current-perpendicular-to-plane (CPP) geometry.
FIG. 8 illustrates a second, non-limiting embodiment of the present invention. In this embodiment, those features that are the same as the first embodiment of FIG. 7 are not repeated. In FIG. 8 , the free layer 117 is a composed free layer, and includes a free layer spacer 203 positioned between an upper sublayer (first free sublayer) 201 and a lower sublayer (second free sublayer) 205 of the free layer 117 . The free layer spacer 203 is made of at least one of Ru, Rh, Pd, Pt, Ir, Os, Ag and Cu, or alloys thereof, and has a thickness between about 0.3 nm and 1 nm. The two sublayers 201 , 205 of the free layer 117 have a total thickness between about 1 nm and 5 nm.
FIG. 9 illustrates a third, exemplary, non-limiting embodiment of the present invention. In this embodiment, those features that are the same as the first embodiment of FIG. 7 are not repeated. In FIG. 9 , the free layer 117 is a composed free layer, and includes at least two, and preferably three, ferromagnetic sublayers 301 , 303 , 305 deposited on each other.
FIG. 10 illustrates a fourth, exemplary, non-limiting embodiment of the present invention. In this embodiment, those features that are the same as the first embodiment of FIG. 7 are not repeated. In FIG. 10 , the ferromagnetic layer 401 , the first AFM layer 403 and the capping layer 404 are deposited after patterning of the MR element and deposition of the insulator 129 . As a result, those layers 401 , 403 of the in-stack bias 119 are larger than the free layer 117 . Thus, the in-stack bias 119 further stabilizes the free layer 117 at its edges (i.e., at the edge of the sensor). Because the in-stack bias 119 is larger than the free layer 117 , and does not stop at the substantially same point as in the previous embodiments (i.e., the edges of the in-stack bias 119 extend beyond the edges of the free layer 117 ), this further stabilization can be achieved.
As the BMR sensor decreases in size and the chance of damage increases during lithography and ion milling if those steps are used, this embodiment avoids this edge effect. Further, as the vortex effect becomes dominant for a smaller size element, this exemplary embodiment substantially reduces the production of noise.
FIG. 11 illustrates a fifth, non-limiting exemplary embodiment of the present invention. In this embodiment, those features that are the same as the first embodiment of FIG. 7 are not repeated. In FIG. 11 , an additional hard bias stabilizer 501 is provided on top of insulator 129 . As a result, the free layer is further stabilized in an efficient manner. The hard bias stabilizer 501 is chosen from hard materials group including CoCr, CoPt and CoCrPt with a thickness from about 5 nm to 30 nm. This additional hard bias stabilizer 501 may also be used with the third and fourth embodiments as discussed above and illustrated in the drawings. The capping layer 126 is positioned above the first AFM 125 .
For all of the above exemplary, non-limiting embodiments of the present invention, the ferromagnetic material in the free layer is of at least one of Ni, Fe, and Co. Alloys of CoNi, CoFe, NiFe, CoFeNi or any combination thereof is preferred. Further, either or both of the AFM layers 105 , 125 is made of at least one of PtMn and IrMn, and has a thickness between about 5 nm and 20 nm. More generally, either or both of these AFM layers 105 , 125 can be made of X—Mn or XY—Mn, where X and Y are made of Pt, Ir, Pd, Ru, Rh, Os, Fe and Ni, and X is different from Y The capping layer 126 is made of at least one of Ta, Cr, Ru, Au and other non-magnetic materials and has a thickness of about 2 to 5 nm.
The first nano-contacts 116 and second nano-contacts 121 comprise at least one of Ni, Co and Fe, and have a diameter of less than about 10 nm. Further, the surrounding insulating matrix (insulator) in the spacer 120 includes at least one of oxides or nitrides such as Al 2 O 3 , AlN, SiO 2 and Si 3 N 4 . This material can also be a highly resistive, insulator having a resistivity higher than about 100 μΩ×cm. Alternatively, the nano-contact 116 may be surrounded by a non-magnetic, conductive matrix made of conductive material such as Cu, Au, Cr or equivalent thereof as the matrix.
With respect to the second nano-contact 121 in the in-stack bias layer 120 , the surrounding insulator) 122 includes oxides and/or nitrides, or a high resistivity material of about 100 μΩ×cm or higher. The second nano-contact 121 can also be surrounded by a non-magnetic conductive material.
Further, in FIGS. 8-11 , the direction of magnetization of the in-stack bias 123 (not illustrated for the sake of clarity) is opposite to the direction of the free layer 117 . However, the present invention is not limited thereto, and other configurations as may be envisioned by one of ordinary skill in the art may also be used.
The present invention has various advantages. For example, but not by way of limitation, the present invention includes a BMR sensor having a free layer stabilized by in-stack bias and an in-stack bias spacer having a nano-contact. As a result, the stability of the free layer is maintained and the effective area of the MR element is reduced due to the confined current path, which results in a higher output read signal.
Additionally, a domain wall is created between the free layer and the ferromagnetic pinned layer used in the stabilizer. Thus, there is an improvement in the MR ratio and resistance change.
Further, in the present invention, a method is provided for preparing the free layer having grains disposed in a matrix made by ion beam sputtering method using a target having at least magnetic material and insulator (e.g. magnetic material like Ni and insulator like Al 2 O 3 . Ni grows as grains surrounded by Al 2 O 3 ). The surface is etched to ensure that those grains reach the surface to form the nano-contact.
Additionally, the foregoing embodiments are generally directed to a magnetoresistive element for a magnetoresistive read head. This magnetoresistive read head can optionally be used in any of a number of devices. For example, but not by way of limitation, as discussed above, the read head can be included in a hard disk drive (HDD) magnetic recording device. However, the present invention is not limited thereto, and other devices that uses the ballistic magnetoresistive effect may also comprise the magnetoresistive element of the present invention. For example, but not by way of limitation, a magnetic random access memory (i.e., a magnetic memory device provided with a nano-contact structure, or a device) may also employ the present invention. Such applications of the present invention are within the scope of the present invention.
The present invention is not limited to the specific above-described embodiments. It is contemplated that numerous modifications may be made to the present invention without departing from the spirit and scope of the invention as defined in the following claims.
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An in-stack bias is provided for stabilizing the free layer of a ballistic magneto resistive (BMR) sensor. In-stack bias includes a decoupling layer that is a spacer between the free layer and a ferromagnetic stabilizer layer of the in-stack bias, and an anti-ferromagnetic layer positioned above the ferromagnetic layer. The spacer is a nano-contact layer having magnetic particles positioned in a non-magnetic matrix. The free layer may be single layer, composed or synthetic, and the in-stack bias may be laterally bounded by the sidewalls, or alternatively, extend above the sidewalls and spacer. Additionally, a hard bias may also be provided. The spacer of the in-stack bias results in the reduction of the exchange coupling between the free layer and ferromagnetic stabilizing layer, an improved AΔR due to confinement of current flow through a smaller area, and increased MR due to the domain wall created within the magnetic nano-contact.
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REFERENCE TO CO-PENDING APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application No. 61/684,558 filed Aug. 17, 2012, which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The present disclosure relates generally to constructions and, more particularly, to shafts constructed in the earth.
BACKGROUND
[0003] Shaft constructions are made in the earth for a number of reasons, including for subaqueous tunneling projects. In these projects, underground tunnels are oftentimes excavated or dug below a body of water such as a river, a lake, a harbor, or a port. The underground tunnels can stretch below the body of water from one side of the body to the other side. Before the tunnels are excavated, a shaft is commonly constructed in the earth down to a vertical depth of tunnel excavation. Shafts are usually constructed at the beginning and at the end of underground tunnels for launching and retrieving excavation equipment and machinery, and for other purposes.
[0004] Earth below the surface near these types of shafts, however, tends to be porous and imbued with groundwater and often has a water table relatively close to its surface. The phrase “water table” is customarily used to describe the depth in the earth below the surface at which water pressure head is equal to atmospheric pressure—in simpler terms, it is where the earth below the surface becomes saturated with groundwater. Constructing shafts below water tables can be challenging because the saturated groundwater can easily seep into the shafts. And inflows of groundwater can hinder and sometimes thwart a shaft's usefulness and, in some cases, can ultimately delay the scheduled construction project and increase project costs.
SUMMARY
[0005] A method of constructing a shaft in the earth may include several steps. One step includes installing a secant pile wall into the earth. The secant pile wall encloses a portion of the earth. Another step includes excavating the portion of the earth enclosed by the secant pile wall. The excavated portion leaves an interior of the shaft and exposes an inside surface of the secant pile wall. Yet another step includes placing a metal liner within the interior of the shaft. And yet another step includes partially or more filling a space located between the inside surface of the secant pile wall and the metal liner with a grout material.
[0006] A shaft construction in the earth may include a secant pile wall, a metal liner, and a grout material. The secant pile wall has an inside surface and has multiple recesses at the inside surface. The metal liner is located interiorly of the secant pile wall. And the grout material is located between the secant pile wall and the metal liner. The grout material is located within the recesses of the secant pile wall.
[0007] A method of constructing a shaft in the earth may include several steps. One step includes installing a secant pile wall into the earth. The secant pile wall encloses a portion of the earth. Another step includes excavating the portion of the earth enclosed by the secant pile wall. The excavated portion leaves an interior of the shaft and exposes an inside surface of the secant pile wall. Yet another step includes forming one or more first recess(es) in the inside surface of the secant pile wall. And another step includes placing a metal liner within the interior of the shaft. The metal liner has one or more second recess(es) located in its structure. Another step includes partially or more filling a space located between the inside surface of the secant pile wall and the metal liner with a grout material. The grout material fills in the first recess(es) and fills in the second recess(es). Friction generated between the grout material and the first recess(es) and between the grout material and the second recess(es) withstand groundwater uplift forces.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] These and other objects, features, and advantages of the present invention will be apparent from the following detailed description of preferred embodiments and best mode, appended claims, and accompanying drawings in which:
[0009] FIG. 1 is a sectional view of an example subaqueous tunneling project utilizing an embodiment of a shaft construction as described herein;
[0010] FIG. 2 is a fragmentary sectional view of an embodiment of a grout pre-treating that can be performed as a part of the shaft construction of FIG. 1 ;
[0011] FIG. 3 is a fragmentary sectional view of an embodiment of a secant pile wall of the shaft construction of FIG. 1 , the secant pile wall shown in the midst of its installation;
[0012] FIG. 4 is a fragmentary perspective view of the secant pile wall of FIG. 3 , shown fully installed in the earth;
[0013] FIG. 5 is a perspective view of an embodiment of a scarifying tool;
[0014] FIG. 6 is a fragmentary sectional view of the shaft construction of FIG. 1 , illustrating an embodiment of a metal liner and an embodiment of a rebar cage;
[0015] FIG. 7 is an enlarged perspective view with portions broken away and in section of a base of the shaft construction of FIG. 1 ;
[0016] FIG. 8 is a full sectional view of the shaft construction of FIG. 1 ; and
[0017] FIG. 9 is a top view of the shaft construction of FIG. 1 .
DETAILED DESCRIPTION
[0018] Referring in more detail to the drawings, FIG. 1 shows a pair of shaft constructions 10 made vertically below a surface S of the earth. In this example application, the shaft constructions 10 are part of an overall subaqueous tunneling project in which an underground tunnel T is excavated and stretches below a body of water B and between the shaft constructions. Here, one of the shaft constructions 10 is designated a launch shaft L for initiating the excavation and digging of the tunnel T via equipment and machinery, while the other shaft construction is designated a retrieval shaft R for recovering the equipment and machinery after tunnel construction. In these applications, the launch shaft L typically has a diameter greater than that of the retrieval shaft R—for example, an approximately twenty-four or twenty-two foot diameter launch shaft opening and an approximately thirteen or fifteen foot diameter retrieval shaft opening—and there can be numerous launch and retrieval shafts for a given construction project. Of course, other diameter values for the shafts are possible. Furthermore, the shaft constructions 10 can be made to a vertical depth of approximately one-hundred feet below the surface S and below the accompanying water table, and can be horizontally situated approximately one-hundred feet from the body of water B; of course, other depths and horizontal situations are possible in other projects. And though described in the context of a subaqueous tunneling project, the shaft constructions 10 shown and described herein could be used in other construction projects and applications, including those not necessarily near a body of water.
[0019] As an aside, and as used herein, the terms axial, radial, and circumferential and their related forms describe directions with respect to the generally cylindrical shape and longitudinal axis of the shaft construction 10 , unless otherwise specified. In this sense then, axial refers generally to a vertical direction up and down relative to the surface S, radial refers generally to a side direction left and right and orthogonal to the axial direction, and circumferentially refers generally to a circular direction around the axial direction.
[0020] Each of the shaft constructions 10 has been designed generally for use below water tables and in conditions of the earth that are porous and imbued with groundwater. Their construction provides an improved seal against groundwater inflow compared to previously-known shaft constructions, and in some cases is altogether impermeable to groundwater. Taking one of the shaft constructions 10 for description purposes, the shaft construction can have various designs and components and can be made with various processes and process sequences, depending in part upon the application in which it will be used and the extent of impermeability desired, as well as other and different considerations. In the embodiment of the figures, the shaft construction 10 may be generally made via a pre-treating grout process, a secant pile wall installation process, a metal liner placement process, a base plug installation process, and a grout material filling process.
[0021] The pre-treating grout process is performed in order to condition a pre-established working zone so that the zone is suitable for subsequent processes in the formation of the shaft construction 10 , by improving the strength of the earth beneath the working zone and by reducing its permeability, among other possible beneficial effects and objectives. The pre-treating grout process, however, is optional and need not be performed in some shaft constructions. Whether it is performed can depend upon assessments of the pre-established working zone site conditions and upon the particular application and project. The exact pre-treating grout process can vary among different projects and applications.
[0022] Referring now to FIG. 2 , in this embodiment eight grouting holes 12 are drilled into the earth and patterned around a footprint F, or general circumferential periphery, of the pre-established working zone and of the ensuing secant pile wall installation. More or less grouting holes 12 may be suitable in other embodiments. The working zone can be established based on planned routing of the underground tunnel, the conditions of the underlying earth, as well as other and different considerations. Once drilled, grouting machinery and equipment injects grouting material into the grouting holes 12 and disperses it vertically down the grouting holes to the depth of the shaft construction 10 and laterally into the surrounding earth. As shown as one example in FIG. 2 , cavities C and other voids that are present in the earth can be filled by the injected grouting material. The exact grouting material used during this process can depend on the conditions of the underlying earth, and can be a chemical or cement based grouting material.
[0023] After pre-treating, if it is indeed performed, the secant pile wall installation process frames an outer cylindrical boundary into the earth of the shaft construction 10 . Referring now to FIG. 4 , a resulting secant pile wall 14 serves as the primary structural support of the shaft construction 10 . The exact secant pile wall installation process can vary among different projects and applications. In the embodiment of FIGS. 3 and 4 , a first set of secant pile holes 16 is initially drilled into the earth adjacent the grouting holes 12 , with individual pile holes spaced away from one another in a generally circular pattern ( FIG. 3 shows this best). Concrete material is then forced into the secant pile holes 16 and allowed to harden and solidify in order to form a first set of secant piles 18 .
[0024] After this, a second set of secant pile holes 20 ( FIG. 4 ) is drilled into the earth at the spaces and locations between the individual piles of the first set of secant piles 18 . Because the spaces between the first set of secant piles 18 are dimensioned and measure less than a diameter of individual holes of the second set of secant pile holes 20 , the second set of holes are physically cut into the sides of the concrete material of the first set of piles. In other words, the first and second set of secant pile holes 16 , 20 —and thus the first and second sets of concrete secant piles—have neighboring holes and piles that intersect and overlap one another at their outer peripheries. As before, concrete material is forced into the second set of secant pile holes 20 and allowed to harden in order to form a second set of secant piles 22 .
[0025] As shown in FIG. 4 , once fully hardened, the first and second set of secant piles 18 , 22 produce the continuous and integral secant pile wall 14 . In one specific example, the individual neighboring secant piles overlap each other by approximately ten inches and the secant pile wall has a radial thickness of approximately fourteen inches; of course, other values of overlap and thickness are possible in other embodiments. Furthermore, the exact concrete material used during this installation can depend on the conditions of the underlying earth. In one specific example, a cement/bentonite concrete material is used. In other embodiments not shown in the figures, the secant pile wall could be made by other secant pile formation techniques, including one in which a concrete material is poured to form a hollow cylinder.
[0026] Although not shown in FIG. 4 , when initially produced the secant pile wall 14 encloses a portion of the earth radially-inwardly and inboard of the secant pile wall. The enclosed portion is subsequently excavated and removed out of the secant pile wall enclosure, leaving in some instances a somewhat empty an interior 24 of the shaft construction 10 and exposing an inside surface 26 of the secant pile wall 14 . Dewatering within the interior 24 can be performed at this stage, though it need not be.
[0027] With the inside surface 26 exposed, recesses 28 can be formed into the inside surface for subsequently receiving grout material during the grout material filling process and for generating friction against uplift forces upon final construction, both of which are described in greater detail below. The recesses 28 are shown best in FIGS. 7 and 8 . Although shown as wavy indentations, the recesses 28 can take multiple forms so long as they have the ability to generate friction against uplift forces. For example, the recesses 28 can simply be crude scrapes or gashes in the inside surface 26 , or can be more refined indentations such as the wavy profile shown or discrete notches randomly located or patterned on the inside surface. In the example of FIGS. 7 and 8 , the recesses 28 take the form of multiple grooves defined in the secant pile wall 14 and disposed all the way top-to-bottom between the open and closed ends of the shaft construction 10 ; an individual groove can extend circumferentially around the inside surface 26 , or the recesses 28 can be a single coarse spiral stretching between the open and closed ends. In other examples, the recesses 28 can extend along the full axial extent of the inside surface 26 between the open and closed ends of the shaft construction 10 , can extend along only a section of the inside surface such as a lower or upper or middle section, or can extend randomly on the inside surface. The recesses 28 are not limited to any particular form, shape, pattern, or quantity.
[0028] Whatever their form, the recesses 28 can be produced by any suitable technique and tooling. For example, FIG. 5 shows a scarifying tool 30 that can be used to score the secant pile wall 14 and create the recesses 28 on the inside surface 26 in the form of scraped grooves. In this embodiment, the scarifying tool 30 is a multi-piece metal structure composed of an inner ring 32 , an outer ring 34 , and four cross-bars 36 welded or bolted to and supporting the inner and outer rings. The inner ring 32 can have a plurality of first cutting teeth 38 attached to and extending from its bottom end for facilitating additional excavation in the event that the interior 24 was previously incompletely excavated. Likewise, one or more of the cross-bar(s) 36 can have a plurality of second cutting teeth 40 attached to and extending from their bottom end(s). And, a plurality of third cutting teeth 42 can be attached to and can extend from a bottom end of the outer ring 34 . In this embodiment, in order to be in position to make contact with the inside surface 26 , the third cutting teeth 42 project radially-outwardly beyond a side surface 44 of the outer ring 34 . The third cutting teeth 42 are also spaced continuously around the circumference of the outer ring 34 . The scarifying tool can have other designs, constructions, and components in other embodiments, with the precise design, construction, and component(s) dictated in part or more by the form of recesses to be created.
[0029] In use, a crane arm 46 may be securely coupled to the scarifying tool 30 , and may forcibly rotate the scarifying tool and move it axially up and down in the interior 24 defined by the secant pile wall 14 . The outer ring 34 is sized diametrically so that the third cutting teeth 42 engage the inside surface 26 and score the inside surface to form the recesses 28 . This scarifying operation can be performed with or without water in the interior 24 .
[0030] Referring now to FIG. 6 , after the secant pile wall installation process is completed and the scarifying finished, the metal liner placement process is performed in order to insert a metal liner 48 within the interior 24 of the shaft construction 10 and radially-inwardly and inboard of the secant pile wall 14 . The metal liner 48 helps seal against groundwater inflow in the fully constructed shaft construction 10 . The exact metal liner placement process, and metal liner component itself, can vary among different projects and applications and embodiments. In the embodiment of FIGS. 6 and 7 , the metal liner 48 is a multi-piece cylindrical structure made up of discrete metal liner segments that are connected together via bolting, welding, or another connection technique. In one specific example, the metal liner segments are made of steel and have an approximately one-eighth inch thickness. The metal liner segments can be fully cylindrical segments or partial cylindrical segments. In the embodiment of the figures, the metal liner 48 has a corrugated structure with multiple recesses 50 on both outside and inside surfaces 52 , 54 . Although the recesses 50 are shown somewhat complementary to the recesses 28 in this embodiment, in other embodiments the recesses need not be complementary at all and one recess could be scrapes while the other could be discrete and random indentations. Its corrugated structure aids in the overall structural integrity of the metal liner 48 , but need not necessarily take this form. Like the recesses 28 of the secant pile wall 14 , the recesses 50 subsequently receive grout material during the grout material filling process.
[0031] In the placement process, the metal liner segments can be connected together before insertion, and the assembled metal liner 48 can then be hoisted above the interior 24 and lowered into the interior via a crane. As an assembly, the metal liner 48 can extend the full axial extent of the shaft construction 10 , and can be sized with a diameter less than that of the secant pile wall 14 . As shown best in FIG. 6 , a space 56 is therefore defined between the outside surface 52 of the lowered metal liner 48 and the inside surface 26 of the secant pile wall 14 . In one specific example, the space 56 can measure approximately twelve inches from surface-to-surface, but of course other examples are possible.
[0032] Additionally, one or more seal(s) can be provided between the connected metal liner segments or at the fully assembled metal liner 48 in order to augment the sealing performance against groundwater intrusion. The seal(s) can take different forms in different examples. In one example, the seal includes multiple rubber gaskets that are bolted or otherwise disposed between the discrete metal liner segments. In another example, the seal can be applied to the fully assembled metal liner 48 in the form of a sprayed epoxy sealer. Still other examples can include stuck-on sealers, glue-based sealers, or tar-based sealers, among other possibilities. And although not shown, a cutout can be located in the metal liner 48 near its lower end for providing access for the subsequent tunnel digging operation.
[0033] Furthermore, a water stop assembly can be provided at a lower end 64 of the metal liner 48 . In one example, the water stop assembly includes a first ring-shaped steel plate welded to the inside surface 54 of the metal liner 48 and projecting radially-inwardly therefrom, and includes a second ring-shaped steel plate welded to the outside surface 52 and projecting radially-outwardly therefrom. The first and second ring-shaped steel plates can extend fully circumferentially around the metal liner 48 . In one specific example, the ring-shaped steel plates have a thickness of approximately one-half inches; of course, other thicknesses are possible in other examples. Additionally, the water stop assembly can include a first tubing that can be injected with a grout material, such as a chemical-based grout, and is positioned on the outside surface 52 of the metal liner 48 opposite the first ring-shaped steel plate. Likewise, a second tubing that can be injected with a grout material, such as a chemical-based grout, is positioned on the inside surface 54 opposite the second ring-shaped steel plate. In one specific example, the first and second tubings have a diameter of approximately one-half inches; of course, other diameters are possible in other examples. Still, the water stop assembly can have other designs, constructions, and components than described here.
[0034] The base plug installation process is performed in order to establish a secured and sealed base plug 58 at the bottom of the shaft construction 10 . The base plug installation process, and base plug 58 itself, can vary among different projects and applications and embodiments. In the embodiment of FIGS. 6-8 , a mud mat 60 composed of a concrete material is first laid on the floor over the exposed earth of the excavated interior 24 (the mud mat is represented by an upwardly-facing bracket in FIG. 8 ). The mud mat 60 can be poured via a tremie concrete pouring technique with a pipe submerged in groundwater sitting in the interior 24 , and can be laid before the metal liner 48 is inserted into the interior. Once the mud mat 60 is hardened, a rebar cage 62 of steel can be lowered on top of the mud mat—again, this step can be performed before the metal liner 48 is inserted into the interior 24 . The rebar cage 62 , if provided, serves as a reinforcement and structural skeleton of the base plug 58 .
[0035] At this point in time, the previously-described lowering of the metal liner 48 can take place; the metal liner can be lowered so that the lower end 64 of the metal liner is positioned close to the rebar cage 62 , abutting the rebar cage, or even slightly below an upper part of the rebar cage. In this embodiment, a concrete material is then poured over the rebar cage 62 via a tremie concrete pouring technique, if suitable, until the rebar cage is completely submerged in the concrete material. The hardened concrete material constitutes a base slab 66 of the base plug 58 . The base slab 66 can be poured to immerse and embed the lower end 64 of the metal liner 48 within the hardened concrete material. If the water stop assembly is provided, the base slab 66 can be poured to also immerse the water stop assembly including its steel plates and its tubings. This secures the base slab 66 and the metal liner 48 together at the lower end 64 , and augments the sealing performance of the shaft construction 10 ; the immersed water stop assembly in particular ensures sealing performance if there is undesired shrinkage of the base slab 66 upon hardening which could otherwise leave a gap between the base slab and the lower end 64 . In one specific example, the base plug 58 is approximately five feet in overall vertical and axial thickness. In different embodiments, the sequence of metal liner placement and base plug installation could differ; for example, the mud mat could be laid, the metal liner could be placed, and then the rebar cage could be lowered; and in another example, the metal liner could be placed, the mud mat could be laid, and then the rebar cage could be lowered, followed by the pouring of the base slab material.
[0036] The grout material filling process is performed to finalize the shaft construction 10 and fill the annular space 56 between the secant pile wall 14 and the metal liner 48 . The grout material filling process can vary among different projects and applications and embodiments. In the embodiment of FIGS. 7-9 , a grout material 68 , such as what-is-known-as neat grout, is poured into the space 56 until the space is completely full of grout material. The grout material 68 can fill in both the recesses 28 of the secant pile wall 14 and the recesses 50 of the metal liner 48 , and can harden therein. In this way, the grout material 68 can harden with protrusions received in the recesses 28 , 50 . After all of the materials have fully hardened and set, the shaft construction 10 can be dewatered, if needed. Moreover, the shaft construction 10 seals against groundwater intrusion without the need to dewater the pre-established working zone, though this can be performed if desired.
[0037] Referring now only to FIG. 8 , when constructed below a water table W and in earth porous and imbued in groundwater, resulting uplift forces U are constantly exerted against the base plug 58 . As shown and described herein, the shaft construction 10 has been designed with certain measures to withstand and counteract and oppose these exerted uplift forces U. One measure is the recesses 28 of the secant pile wall 14 filled with the grout material 68 . This generates friction and provides a mechanical interlocking functionality between the secant pile wall 14 and the grout material 68 that can hold the components of the shaft construction 10 in place. Another measure is the recesses 50 of the metal liner 48 filled with the grout material 68 . Again, this generates friction and provides a mechanical interlocking functionality between the metal liner 48 and the grout material 68 that can hold the components of the shaft construction 10 in place. Yet another measure is the lower end 64 of the metal liner 48 immersed and captured in the base slab 66 . Not all of these measures need to be provided in the shaft construction 10 , as only one of the measures may sufficiently withstand the uplift forces U exerted in a particular application. Indeed, in one embodiment, neither recesses 28 nor 50 need to be provided, as sufficient friction may be generated between the metal liner 48 and grout material 68 and between the secant pile wall 14 and grout material to withstand the uplift forces U.
[0038] While the forms of the invention herein disclosed constitute presently preferred embodiments, many others are possible. It is not intended herein to mention all the possible equivalent forms or ramifications of the invention. It is understood that the terms used herein are merely descriptive, rather than limiting, and that various changes may be made without departing from the spirit or scope of the invention.
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A method of constructing a shaft in the earth for use as, for example, a launch shaft or a retrieval shaft, may include several steps. One step includes installing a secant pile wall into the earth. The secant pile wall encloses a portion of the earth. Another step includes excavating the portion of the earth enclosed by the secant pile wall. The excavated portion leaves an interior of the shaft and exposes an inside surface of the secant pile wall. Yet another step includes placing a metal liner within the interior of the shaft. And yet another step includes partially or more filling a space located between the inside surface of the secant pile wall and the metal liner with a grout material.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of copending PCT Application PCT/US96/12160, filed Sep. 12, 1995, designating the United States, which claims priority from South African application no. 94/0711, filed Sep. 12, 1994, both of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to a process for treating a liquid. It also relates to a process for recovering citric acid.
SUMMARY OF THE INVENTION
[0003] According to a first aspect of the invention, there is provided a process for treating a liquid, which process comprises: (a) subjecting a liquid containing solution, citric acid as well as a less desirable component having a similar molecular weight to citric acid, to nanofiltration in a filtration step; and (b) obtaining, from the filtration step, a permeate in which the ratio of the concentration of the citric acid to that of the less desirable component is greater than the ratio of the concentration of the citric acid to that of the less desirable component in the solution.
[0004] In other words, there is a greater degree of rejection of the less desirable component than of the citric acid in the filtration step. The nanofiltration will normally involve contacting the liquid with a nanofiltration membrane. Nanofiltration will naturally also separate the citric acid from any component with a molecular weight which is significantly greater than that of citric acid.
[0005] The molecular weight or relative molecular mass of the less desirable component may be within 20% of that of citric acid. For example, the molecular weight of the less desirable component may be within 10%, and even within about 7%, of that of citric acid. In other words, the molecular weight of the second component may range from 0.8MW-1.2MW, e.g., 0.9MW-1.1MW, or even about 0.93MW—about 1.07MW, where MW is the molecular weight of the citric acid.
[0006] The Applicant believes that the process will have particular, but not necessarily exclusive, application in the treatment of fermentation broth to separate citric acid present therein as a fermentation product from residual glucose and/or fructose, thereby recovering the citric acid. It has been found that, with the process of the invention, the citric acid can be separated from residual glucose and/or fructose as well as other impurities such as medium and higher molecular weight by-products such as peptide and polysaccharides, produced by fermentation microorganisms, and which can be undesirable. In other words, the process has specific application in the recovery of citric acid from a fermentation broth, particularly from a clarified citric acid fermentation broth.
[0007] The clarified citric acid fermentation broth can typically be that obtained by fermenting a carbohydrate feedstock to produce citric acid-rich fermentation broth and waste solids, and separating the broth from the solids.
[0008] Citric acid has a similar molecular mass to glucose and fructose and can preferentially be separated from glucose and/or fructose in the process according to the invention, as a result of its greater permeability through the nanofiltration membrane as compared to that of glucose and/or fructose.
[0009] The filtration step may be carried out at a concentration of the citric acid in the broth of 5%-30% by mass, preferably 10%-20% by mass, and the nanofiltration may be carried out at a temperature of 10° C.-100° C., preferably 20° C.-50° C. The pressure drop across the nanofiltration membrane will depend on the nature of the membrane and one the nature of the citric acid and the less desirable component to be separated and can be established by routine experimentation.
[0010] The clarified citric acid fermentation broth may, before the filtration step, be subjected to cation exchange to remove cations, such as potassium and magnesium ions, therefrom.
[0011] The process may include further treating the citric acid solution from the filtration step to purify it and/or to obtain a more concentrated citric acid fraction, or solid citric acid or a derivative of citric acid, such as sodium citrate.
[0012] Thus, the citric acid solution from the filtration step may be purified by anion exchange, e.g., to remove traces of anionic impurities, and/or by contacting it with activated carbon to remove traces of organic matter.
[0013] The purified citric acid solution may then be concentrated. This may include treating the solution to obtain solid pure citric acid and residual mother liquor. The concentration may include subjecting the solution to at least one evaporation and crystallization sequence. In particular, the concentration may include passing the solution sequentially through an evaporator; a first crystallizer; a first centrifuge; optionally a dissolution tank, a second crystallizer and a second centrifuge; and producing mother liquor in the first centrifuge and, when present, in the second centrifuge. A portion of the mother liquor from the second centrifuge, when present, may then be recycled to the first crystallizer, while the mother liquor from the fist centrifuge is withdrawn. The contacting of the citric acid solution with the activated carbon hereinbefore referred to may instead, or additionally, be effected after the purified citric acid solution has been concentrated at least partially, e.g., after it has passed through the evaporator.
[0014] The process may also include: (i) recycling a portion of the mother liquor from the first centrifuge to upstream of the evaporator; and/or (ii) withdrawing at least a portion of the mother liquor from the first centrifuge as a liquid product; and/or (iii) drying and/or granulating at least a portion of the mother liquor from the first centrifuge to obtain a solid citric acid/carbohydrate product; and/or (iv) treating at least a portion of the mother liquor from the first centrifuge, in a recovery step, to recover citric acid for recycle, or citrate salts as product.
[0015] When the process includes treating at least a portion of the mother liquid from the first centrifuge in a recovery step to recover citric acid, this citric acid may be recycled to upstream and/or downstream of the nanofiltration step. The treatment in the recovery step may then comprise one of the following: calcium citrate precipitation by adding lime thereto and redissolving with sulphuric acid; solvent extraction of citric acid utilizing a suitable solvent, followed by re-extraction of citric acid from the solvent into water using concentration differences or heating; ion exchange using a resin which selectively adsorbs citric acid, followed by elution; or various types of chromatography.
[0016] At least a portion of the retentate from the filtration step may be withdrawn as a liquid product. Instead, or additionally, at least a portion of the retentate from the filtration step may be dried or granulated to obtain a solid citric acid product. Instead, or additionally, at least a portion of the retentate from the filtration step may be treated in a citric acid recovery step, which may then be the same as the citric acid recovery step, hereinbefore described, to recover citric acid or a derivative thereof therefrom.
[0017] The retentate from the filtration step may be combined with the mother liquor from the first centrifuge for withdrawal as a liquid product and/or for drying or granulating and/or for treatment in a recovery step, as hereinbefore described.
[0018] According to a second aspect of the invention, there is provided a process for recovering citric acid, which process comprises subjecting a clarified citric acid fermentation broth to nanofiltration in a filtration step to obtain as a permeate, a purified citric acid solution.
[0019] The clarified citric acid fermentation broth may, before the filtration step, be subjected to cation exchange as hereinbefore described. The citric acid solution from the filtration step may be treated further to purify it and/or to obtain a more concentrated citric acid fraction, or solid citric acid or a derivative of citric acid, as hereinbefore described. The filtration step may also be as hereinbefore described.
[0020] The invention will now be described by way of example, with reference to the accompanying simplified flow diagram in FIG. 1 of a process according to the invention for treating a fermentation broth, and with reference to the non-limiting examples.
BRIEF DESCRIPTION OF THE DRAWING
[0021] [0021]FIG. 1 is a flow diagram of a process for treating a fermentation broth.
DETAILED DESCRIPTION OF THE INVENTION
[0022] In FIG. 1, reference numeral 10 generally indicates a process according to the invention for treating a fermentation broth.
[0023] The process 10 includes a cation exchanger stage 32 . A clarified citric acid fermentation broth feed line 30 leads from a fermentation stage (not shown) into the stage 32 . A regeneration water/acid flow line 34 also leads into the stage 32 , while a waste product withdrawal line 36 leads from the stage 32 . A flow line 38 also leads from the stage 32 .
[0024] The flow line 38 leads to a nanofiltration step or stage 40 , with a waste product or retentate withdrawal line 42 leading from the stage 40 . A cleaning water/base and diafiltration flow line 41 leads into the nanofiltration stage 40 . A filtrate flow line 44 leads from the stage 40 to an anion exchanger 46 , with a regeneration water/base flow line 48 leading into the exchanger 46 . A waste product withdrawal line 49 leads from the stage 46 , while a flow line 50 leads from the exchanger 46 to an activated carbon bed stage 52 .
[0025] A flow line 54 leads from the stage 52 to an evaporation stage 56 , with a steam flow line 58 leading into the stage 56 . A condensate line 60 leads from the stage 56 . A flow line 62 leads from the stage 56 to a first crystallization stage 64 . A flow line 66 leads from the crystallization stage 64 to a first centrifugation stage 68 . A flow line 70 leads from the first centrifugation stage 68 to a dissolution tank 72 , with a water make-up line 74 leading into the tank 72 . A flow line 76 leads from the tank 72 to a second crystallization stage 78 , with a flow line 80 leading from the second crystallization stage 78 to a second centrifugation stage 82 . A mother liquor recycle line 84 leads from the stage 82 to the crystallization stages 64 , 78 . A flow line 86 leads from the second centrifugation stage 82 to a drier 88 , with a flow line 90 leading from the drier 88 to a screening stage 92 . A solid product withdrawal line 94 leads from the screening stage 92 .
[0026] The second crystallization stage 78 and second centrifugation stage 82 are used to improve crystal quality and are optional; they can be dispensed with, if necessary.
[0027] A mother liquor withdrawal line 96 leads from the first centrifugation stage 68 .
[0028] In a first embodiment of the invention, the line 96 can be routed back to the flow line 50 for recycling a portion of the mother liquor.
[0029] In a second embodiment of the invention, the flow line 96 call lead to a suitable liquid product withdrawal stage 98 .
[0030] In a third embodiment of The invention, the flow line 96 can lead to a drying and granulation stage 100 .
[0031] In a fourth embodiment of the invention, the flow line 96 can lead to a recovery stage 102 . A waste product withdrawal line 104 leads from the stage 102 . A citric acid recycle line 106 leads from the stage 102 back to upstream and/or downstream of stage 40 .
[0032] It will be appreciated that the first, second, third and fourth embodiments described hereinbefore are optional and can be used individually, or a combination of two or more of the embodiments can be used, as desired.
[0033] A flow line 108 can, if desired, lead from the flow line 42 to the flow line 96 upstream of the product withdrawal stage 98 , the drying and granulation stage 100 , and/or the citric acid recovery unit 102 .
[0034] In use, clarified citric acid fermentation broth, produced in known fashion in the fermentation stage, passes to the cation exchanger 32 where it is contacted with a suitable resin to remove cations such as calcium and sodium ions. If these ions are not removed they would form complexes with the citrate ions and be retained by the nanofilter element in the subsequent filtration stage 40 leading to product losses. The resin bed can be regenerated in known fashion, when required.
[0035] The broth then passes to the nanofiltration stage 40 where the citric acid is separated, by contacting the broth with a nanofiltration membrane, from glucose, fructose, and higher molcular weight components in the broth such as protein, residual anti-foaming agents, sucrose, peptides and polysaccharides which thus form the retentate. Smaller molecules as well as some anions pass through the nanofiltration membrane and, together with the citric acid and most of the water, form the permeate. The permeate is thus in the form of a purified citric acid solution in which the ratio or proportion of the concentration of citric acid to that of glucose and fructose is greater than the ratio or proportion or the concentration of citric acid to that of the glucose and fructose in the feed to the stage 40 . Thus, in the filtration stage 40 , glucose and fructose, which have a similar molecular weight ( 180 ) to citric acid ( 192 ) are separated therefrom.
[0036] The permeate from the filtration stage 40 passes to the anionic exchanger 46 where anionic impurities are removed and withdrawn. The resin bed of the anionic exchanger 46 is regenerated in known fashion, when required.
[0037] The citric acid containing solution from the exchanger 46 passes to the activated carbon bed stage 52 where traces of organics are removed.
[0038] The citric acid solution thereafter passes to the evaporator where it is concentrated, using steam, from a concentration of 10% to 20% by mass citric acid, typically up to about 65% to 80% by mass citric acid. Condensate from the evaporation stage 56 leaves along the line 60 . The concentrated citric acid solution passes to the first crystallization stage 64 where crystallization of the citric acid is effected. The stream then passes to the first centrifuge stage 68 where the citric acid crystals are separated from the mother liquor. The citric acid crystals pass into the dissolution tank 72 where they are redissolved in make-up water, whereafter they are recrystallized in the second crystallization stage 78 to improve crystal quality. The make-up water may be obtained from any suitable source, such as process condensate, a dilute citric acid stream, or the like. The stream from the crystallization stage 78 passes to the second centrifugation stage 82 where mother liquor is again removed. The moist crystals pass to the drier 88 , with dried crystals passing to the screening stage 92 . Dried solid substantially pure citric acid crystals are withdrawn along the flow line 94 .
[0039] The crystallization stages 64 , 78 typically comprise known crystallizers, and will thus include ancillary equipment normally associated therewith such as steam feed/condensate outlet lines, cooling fluid lines, and the like.
[0040] Mother liquor from the first centrifugation stage 68 is withdrawn along the flow line 96 .
[0041] In a first embodiment, a portion of this mother liquor can be recycled to the activated carbon bed 52 .
[0042] In a second embodiment, at least a portion of this mother liquor can be withdrawn as a liquid product in the stage 98 .
[0043] In a third embodiment, at least a portion of this mother liquor can be dried and granulated in the stage 100 to obtain a citric acid/carbohydrate solid commercial product.
[0044] In a fourth embodiment, at least a portion of this mother liquor can pass to the recovery stage 102 . Waste product, e.g., glucose and trace impurities, from the recovery stage 102 is withdrawn, while if pure citric acid is recovered, it may be recycled to upstream or downstream of stage 40 ; or if citrate salts are recovered, they will be recovered as product. A portion of the retentate from the nanofiltration stage 40 can be routed, by means of the flow line 108 , to the stream 96 and then routed to any of the optional stages 98 , 100 and/or 102 , If desired, to recover residual citric acid or a derivative thereof present in this stream.
[0045] In one version of the invention, the recovery stag 102 may utilize calcium citrate precipitation after lime addition; followed by sulphuric acid addition to form citric acid as well as the by product gypsum, to recover citric acid.
[0046] In another version, the citric acid in the mother liquor may, in the stage 102 , be extracted using a suitable solvent, followed by re-extraction citric acid from the solvent phase into water using concentration differences or with the aid of heat.
[0047] In yet another version, the recovery stage 102 may comprise an ion exchange resin which selectively adsorbs citric acid, with elution of the product into water thereafter taking place.
[0048] In yet a further version of the invention, the citric acid recovery stage may comprise various types of chromatography.
[0049] The Applicant believes that with the process 10 , citric acid can be recovered effectively and at relatively low cost. In addition it is believed that the process 10 will be relatively simple to operate.
EXAMPLES
[0050] The following examples are provided for illustrative purposes, and are not intended to limit the scope of the invention as claimed herein. Any variations in the exemplified methods which occur to the skilled artisan are intended to fall within the scope of the present invention.
Example 1
[0051] The process 10 of the invention was simulated theoretically as follows.
[0052] Clarified citric acid fermentation broth containing 18.4 weight percent citric acid, can be obtained by fermentating various cultures, such as Aspergillus niger , on a purified carbohydrate feedstock, and filtering off the resultant biomass. The broth leaving the fermenters can contain 0.2% (w/w) unfermented glucose or 0.2% (w/w) unfermented fructose.
[0053] The clarified citric acid fermentation broth is then subjected to cation exchange, to remove cations such as potassium and magnesium ions.
[0054] The clarified decationized citric acid fermentation broth is then contacted with a nanofiltration membrane, and 80 or more percent of the citric acid transfers to the permeate, which contains up to 18 weight percent citric acid. The permeate also contains the following from the clarified decationized citric acid fermentation broth: a portion of the glucose and fructose, anions, cations, amino acids and sucrose, as well as 80 or more percent of the water. The retentate can be treated in a citric acid recovery step, using the UOP™ Citric Acid Sorbex™ Process (Citrex™), to recover the remaining citric acid,
[0055] The permeate from the nanofiltration step can be subjected to anion exchange, to remove traces of anionic impurities, followed by contacting with activated carbon, to remove traces of organics.
[0056] The permeate can thereafter be concentrated by evaporation in an evaporator, followed by a first crystallizer, a first centrifuge, a dissolution tank, a second crystallizer and a second centrifuge; with 20% by weight of the mother liquor from the second centrifuge being recycled to the first crystallizer, while the mother liquor from the first centrifuge is withdrawn.
[0057] The process can include (i) recycling 25% (w/w) of the mother liquor from the first centrifuge to upstream of the evaporator, (ii) withdrawing 10.0% (w/w) of the mother liquor from the first centrifuge as a liquid product, (iii) drying and granulating 21.6% (w/w) of the mother liquor from the first centrifuge to obtain a solid citric acid/carbohydrate product; and (iv) treating the remainder of the mother liquor from the first centrifuge, together with 80% (w/w) of the nanofiltration retentate, using the UOP™ Citric Acid Sorbex™ Process (Citrex™) process (this process revolves around any one of various chromatographic techniques, such as ion exclusion chromatography, whereby citric acid is separated from the feed stream by selective adsorption onto a solid adsorbent) in a recovery step, to recover citric acid which can be recycled to downstream of the nanofiltration step.
[0058] In the Citrex recovery step, which uses a very dilute solution of sulfuric acid as desorbent, the extract can contain, from the feed stream, on a weight to weight basis: 92% of the citric acid, 1% of the glucose and fructose, 1% of the cations and anions, 1% of the amino acids and biomass, negligible sulfuric acid, and 44% of the water from both the feed stream and the desorbent stream. The balance of the above mentioned components report to the raffinate (waste stream).
[0059] In a simulation of the nanofiltration step or stage 40 , laboratory scale tests were conducted on simulated citric acid fermentation broths coding, by mass, 18-19% citric acid, 1% lactose, 0.2% glucose and 0.05% yeast extract. The yeast extract was used to mimic other components normally present in commercial formation broths. Each test was conducted with a pair of membranes, by treating a batch of the simulated broth.
[0060] Concentrations of each of the components were measured, and the rejections calculated. The results are set out in Tables 1. 2 and 3 (all percentages are on a mass bases).
TABLE 1 Results of Nanofiltration Test 1 Experiment 1 Citric Acid % Lactose % Glucose % Feed 18.8 0.88 0.22 Permeate- Membrane A 12.3 0.01 0.03 Permeate- Membrane B 14.6 0.18 0.09 Concentrate 29 2.1 0.47
[0061] [0061] TABLE 2 Results of Nanofiltration Test 2 Experiment 2 Citric acid % Lactose % Glucose % Feed 18 0.88 0 Permeate- Membrane A 11.4 0.01 none Permeate- Membrane B 11.7 0.05 0.07 Concentrate 28 1.9 0.38
[0062] [0062] TABLE 3 Rejections of the two membranes Rejections expressed as percentages Citric acid Lactose % Glucose % Filmtec NF45 Test 1 34.6 98.9 86.4 Test 2 36.7 98.9 >90 MPKW MPF23 Test 1 22.3 79.5 59.1 Test 2 35.0 94.3 65.0
[0063] One of the key parameters in nanofiltration is the rejection. For the simulated citric acid fermentation broths, it was expected, according to literature and product information, that membrane rejections would be in the order lactose>citric acid>glucose, However, as can be seen from Table 3, the actual rejection of citric acid was surprisingly found to be lower than that of glucose.
[0064] This feature thus provides the basis for a simple and efficient means of separating citric acid from high and medium molecular weight impurities as well as removing most of the residual glucose, in respect of fermentation broth.
[0065] It is to be appreciated that, together with the citric acid, other more valuable fermentation products can be separated from the glucose.
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A process for treating a liquid comprising subjecting a liquid containing, in solution, citric acid as well as a less desirable component having a similar molecular weight to citric acid, to nanofiltration in a filtration step. From the filtration step, a permeate in which the ratio of the concentration of the citric acid to that of the less desirable component is greater than the ratio of the concentration of the citric acid to that of the less desirable component in the solution, is obtained.
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TECHNICAL FIELD
The invention relates generally to multi-channel systems and, more particularly, to reducing skew in multi-channel systems.
BACKGROUND
Referring to FIGS. 1A and 1B of the drawings, the reference numeral 100 generally designates a conventional bed scanner. Scanner 100 generally comprises a housing 118 that includes a translucent or transparent sheet 112 , which is commonly referred to as “scan glass.” Below the sheet 112 , there is a carriage 102 , which is mounted on a track 120 , that moves between initial and final positions. As the carriage 102 moves between the initial and final positions, the light source 104 transmits light through sheet 102 . Light is then reflected off the scanned item along the optical axis 110 (through lens array 106 ) to image sensor 108 (which is generally a CMOS or charged coupled device (CCD) sensor array).
Turning to FIG. 1C , one line of sensor 108 is shown. This line includes sensors 114 - 1 to 114 -L that are sensitive to red, blue, and green wavelengths of visible spectrum (which are commonly used in color scanners). Each of these sensors 114 - 1 to 114 -L is coupled to one of the drivers 116 - 1 to 116 -L so as to generate output signals OUT 1 to OUTL.
Generally, the sensor 108 is divided in to several parts or sections where each part or sections includes several sensors (such as sensor 114 - 1 ). Typically, there are M parts or sections that include N sensors. As shown in FIG. 2 , each of the M parts of section is associated with one of the input devices 202 - 1 to 202 -M (where each has N channels) of processing circuitry 200 . These input devices 202 - 1 to 202 -M are typically N-channel analog front ends or AFEs that generate signals for a processing unit or processor 204 . Because each of the input devices 202 - 1 to 202 -M is a separate integrated circuit or IC (where each has some differences due to manufacturing process variations), there is skew between the inputs to the processing unit 204 . Thus, there is a need for a method and/or apparatus that compensates for skew.
Some examples of conventional circuits are: U.S. Pat. Nos. 6,696,995; 7,006,021; 7,342,520; U.S. Patent Pre-Grant Publ. No. 2009/0259781.
SUMMARY
A preferred embodiment of the present invention, accordingly, provides an apparatus. The apparatus comprises an image sensor; and an analog front end (AFE) having: a first AFE unit that is coupled to the image sensor through a first set of channels, wherein the first AFE unit outputs a first AFE data packet for each of the first set of channels during each cycle of a clock signal; and a second AFE unit that is coupled to the image sensor through a second set of channels and that is coupled to the first AFE unit, wherein the second AFE unit outputs the first AFE data packet for each of the first set of channels and a second AFE data packet for each of the second set of channels during each cycle of the clock signal.
In accordance with a preferred embodiment of the present invention, the clock signal further comprises a system clock signal, and wherein the first AFE unit outputs the first AFE packet for each of the first set of channels within the one cycle of a first clock signal, and wherein the second AFE unit outputs the second AFE packet for each of the second set of channels within the one cycle of a second clock signal, and wherein the first and second clock signals having frequencies that are integer multiples of the frequency of the system clock signal.
In accordance with a preferred embodiment of the present invention, the first and second AFE units further comprise first and second integrated circuits (ICs).
In accordance with a preferred embodiment of the present invention, the contact image sensor, the first AFE unit, and the second AFE unit are secured to a scanner board.
In accordance with a preferred embodiment of the present invention, the apparatus further comprises: a processor that is coupled to the AFE and that is secured to the scanner board; a driver that is coupled to the contact image sensor, that is coupled to the processor, and that is secured to the scanner board; and a communication port that is coupled to at least one of the AFE and processor and that is secured to the scanner board.
In accordance with a preferred embodiment of the present invention, the communication port further comprises a first communication port, and wherein the apparatus further comprises: a second communication port that is secured to a main board; a third IC that is coupled to the second communication port and that is secured to the main board; and a communication channel that is coupled to the first and second communication ports.
In accordance with a preferred embodiment of the present invention, low voltage differential signal (LVDS) transmissions are provided over the communication channel.
In accordance with a preferred embodiment of the present invention, CMOS transmissions are provided over the communication channel.
In accordance with a preferred embodiment of the present invention, an apparatus is provided. The apparatus comprises an image sensor; and an AFE having a plurality of AFE units coupled in series with one another in a sequence, wherein each AFE has a set of channels, and wherein each AFE unit is coupled to the image sensor through its set of channels, and wherein each AFE unit outputs an AFE data packet for each of its channels and an AFE data packet from each channel of each preceding AFE unit in the sequence during each cycle of a clock signal.
In accordance with a preferred embodiment of the present invention, a method is provided. The method comprises receiving analog image data at each channel of a plurality of AFEs, wherein the plurality of AFEs are coupled in series with one another in a sequence, and wherein the last AFE of the sequence is coupled to an IC; outputting, at about the same time, an AFE data packet from each AFE, corresponding to its first channel, to at least one of a subsequent AFE in the sequence and the IC; and repeating the step of outputting for of the remaining channels of each AFE such that the AFE data packet for each channel of each AFE is output to the IC within one cycle of a clock signal.
In accordance with a preferred embodiment of the present invention, the clock signal is a system clock signal, and wherein the method further comprises generating a plurality of output clock signals, wherein the frequency of each output clock is an integer multiple of frequency of the system clock signal, and wherein each clock signal is associated with at least one of the AFEs.
In accordance with a preferred embodiment of the present invention, each AFE data packet is output from its corresponding AFE within one clock cycle of the output clock signal of its corresponding AFE.
In accordance with a preferred embodiment of the present invention, the step of outputting further comprises outputting, substantially simultaneously, the AFE data packet from each AFE, corresponding to its first channel, to at least one of a subsequent AFE in the sequence and the processor.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
FIGS. 1A through 1C are diagrams of a conventional scanner;
FIG. 2 is a block diagram of a processing circuitry for the scanner of FIG. 1 ;
FIGS. 3A through 3C are block diagrams of examples of systems for a scanner in accordance with a preferred embodiment of the present invention;
FIG. 4 is a block diagram of processing circuitry for the systems of FIGS. 3A through 3C ;
FIG. 5 is an example of a timing diagram for the processing circuitry of FIG. 4 ;
FIG. 6A is a circuit diagram of an example of the analog front end (AFE) of FIGS. 3A through 3C ;
FIG. 6B is a timing diagram for the AFE of FIG. 6A ;
FIG. 7A is a circuit diagram of an example of the AFE of FIGS. 3A through 3C ;
FIG. 7B is a timing diagram for the AFE of FIG. 7A ;
FIGS. 8A through 8C are circuit diagrams of an example of the AFE of FIGS. 3A through 3C ;
FIG. 8D is a timing diagram for the AFE of FIGS. 8A through 8C ;
FIGS. 9A and 9B are circuit diagrams of an example of the AFE of FIGS. 3A through 3C ; and
FIG. 9C is a timing diagram for the AFE of FIGS. 9A and 9B .
DETAILED DESCRIPTION
Refer now to the drawings wherein depicted elements are, for the sake of clarity, not necessarily shown to scale and wherein like or similar elements are designated by the same reference numeral through the several views.
Turning to FIG. 3A , system 300 - 1 can be seen. In system 300 - 1 , there is a scanner board 302 - 1 (which is typically secured to a carriage, like carriage 102 ) and a main board 304 - 1 (which is typically secured to a housing, like housing 118 ), which communicate with one another over communication channel 316 - 1 . In system 300 - 1 , communication channel 316 - 1 enabled low voltage differential signals (LVDS) to be transmitted between boards 302 - 1 and 304 - 1 .
Each of board 302 - 1 and 304 - 1 generally include several components that are employed for image processing. In particular, board 302 - 1 generally comprises image sensor 108 , driver 308 , processing circuitry 310 - 1 , and output port 312 - 1 . Typically, in operation, image sensor 108 provides analog data over communication channel 306 . Preferably, communication channel 306 has 24 channels. This analog data is received by analog front end (AFE) 318 - 1 (which typically comprises 4 AFE integrated circuits of ICs with 6 analog channels each). The AFE 318 - 1 converts the data into digital data for further processing by processor 320 . Processing circuitry 310 - 1 is then able to provide further controls and/or communications to driver 308 and output port 312 - 1 . Board 304 - 1 includes a port 314 - 1 (which receives LVDS signals from port 312 - 1 ) and an application specific integrated circuit or ASIC 322 .
Turning to FIG. 3B , a system 300 - 2 can be seen which is similar to system 300 - 1 . Some differences are, however, that AFE 318 - 2 (and processing circuitry 310 - 2 ), port 312 - 2 , communication channel 316 - 2 , and port 314 - 2 communicate with one another with CMOS signals instead of LVDS signals.
In FIG. 3C , the configuration of system 300 - 3 is very different from systems 300 - 1 and 300 - 2 . In particular, image sensor 108 employs port 312 - 3 to provide analog signals to main board 304 - 3 over communication channel 316 - 3 . AFE 318 - 3 is secured to main board 304 - 3 and is coupled to port 314 - 3 and ASIC 322 . Here, AFE 318 - 3 has the same general function as AFEs 318 - 1 and 318 - 2 .
AFEs have previously been used in many systems, but AFEs 318 - 1 , 318 - 2 , and 318 - 3 (hereinafter referred to as AFE 318 ) has a different configuration. Specifically, as shown in FIG. 4 , AFE 318 has several AFE units 324 - 1 through 324 -M coupled in series with one another in a sequence. In operation, each of these AFE units 324 - 1 through 324 -M (which each have N channels) receive analog data from an image sensor (like image sensor 108 ), but the final AFE unit 324 -M of the sequence is in communication with the processor 320 or ASIC 322 .
Turning to FIG. 5 , an example of the operation of AFE 318 of FIG. 5 can be seen. In this example, it is assumed that there are three AFE units (M=3) that each have three channels (N=3). As shown, there is a system clock signal SCLK and three output clock signals DCLK 1 , DCLK 2 , and DCLK 3 (which are each associated with one of the three AFE units). These output clock signals DCLK 1 , DCLK 2 , and DCLK 3 have a frequency that is an integer multiple of the frequency of the system clock SCLK (but not aligned with the system clock SCLK); in this example, output clock signals DCLK 1 , DCLK 2 , and DCLK 3 have frequencies that are 3, 6, and 9 times the frequency of the system clock.
In operation, the timing of the system is dependant on the both the number of channels for each AFE unit and the number of AFE channels. In particular, AFE data packets (i.e., D 1 : 1 , which corresponds to the first channel of the first AFE unit) for each channel are output from the AFE 318 within one cycle of the system clock signal SCLK. In this example, AFE data packets the first channel of each AFE unit is output either to a subsequent AFE unit or the processor 320 (or ASIC 322 ) substantially simultaneously (shown with output signals DOUT 1 , DOUT 2 , and DOUT 3 ). Within one cycle of the output clock signal DCLK 1 , data packets for the first channel of each of the AFE units D 3 : 1 , D 2 : 1 , and D 1 : 1 are output from the last AFE unit in the sequence to the processor 320 (or ASIC 322 ). This process is repeated until the data packets for each channel of each AFE unit is output to the processor 320 (or ASIC 322 ), which is accomplished within one cycle of system clock signal SCLK.
Turning now to FIG. 6A , a circuit diagram of example of the AFEs 318 - 1 , 318 - 2 , and 318 - 3 of FIGS. 3A through FIG. 3C (hereinafter referred to as AFE 318 ) can be seen. In AFE 318 of FIG. 6A , there several AFE units 324 - 1 through 324 -M that have a substantially similar configuration and are coupled in series with one another. Looking to AFE units 324 - 1 to 324 -M each clock multiplier 608 - 1 to 608 -M receives the clock signal SCLK (which is delayed by delay elements 610 - 1 to 610 -M, respectively) to generate a select signal SEL 1 to SELM, respectively, and an output clock signal DOUT 1 to DOUTM, respectively. The select signals SEL 1 to SELM control their respective multiplexers 602 - 1 to 602 -M, which output their respective input signal DIN 1 to DINM with a “1” or the previous output signal DOUT 1 to DOUT (M- 1 ) with a “0”. D flip-flops 604 - 1 to 604 -M receive the output from their respective multiplexers 602 - 1 to 602 -M and are clocked by their respective output clock signals DCLK 1 to DCLKM. The output from each D flip-flop 604 - 1 to 604 -M is then delayed by delay element 606 - 1 to 606 -M, respectively.
As can be seen in FIG. 6B , the operation of the AFE 318 of FIG. 6A is substantially similar to the operation of the AFE 318 of FIG. 5 ; however, one difference is the use of the select signals SEL 1 to SEL 3 . These select signals SEL 1 to SEL 3 are used to control multiplexers (i.e., 602 - 1 , 602 - 2 , and 602 - 3 ) and select between the input signals DIN 1 through DIN 3 and the output DOUT 1 and DOUT 2 from the previous AFE units. For the first AFE unit, select signal SEL 1 is logic high “1” so that the output because there is no previous AFE unit. Select signals SEL 2 and SEL 3 are aligned with their respective output clock signals DCLK 2 and DCLK 3 and each has a frequency that is an integer multiple division (i.e., ½ or ⅓) of their respective output clock signals DCLK 2 and DCLK 3 .
Turning to FIGS. 7A and 7B , another example of AFE 318 of FIGS. 3A through 3C can be seen. In this example, the configuration of the AFE units 324 - 1 to 324 -(M- 1 ) of FIG. 7A are similar to the AFE units 324 - 1 to 324 -M of FIG. 6A , but, in FIG. 7A , D flip-flops 604 - 1 to 604 -(M- 1 ) precede their respective multiplexers 606 - 1 to 606 -(M- 1 ). Additionally, select signals SEL 1 to SELM are provided from AFE unit 324 -M, namely select controller 614 . The controller 614 generates select signals SEL 1 to SELM, and outputs these signals as SELBUS in FIG. 7A . When SEL 1 is logic high or “1”, then AFE unit 324 -M captures data from the input signal DIN 1 through each multiplexer (i.e., 602 - 1 to 602 -M). When select signal SEL 2 is logic high or “1” and select signals SEL 3 to SELM are logic low or “0”, then AFE unit 324 -M captures data from the input signal DIN 2 . The AFE unit 324 -M can select data from input signals DIN 1 to DINM by controlling select signals SEL 1 to SELM. In FIG. 7B , input signals DIN 1 to DIN 3 are registered in D flip-flops 604 - 1 to 604 - 3 by setting SEL 2 to logic high. After registering data from AFE 324 - 2 , the AFE unit 324 - 3 selects the AFE 324 - 1 data by setting SEL 2 to logic low. By changing SELBUS by the controller 614 , AFE unit 324 -M output each AFE data to the processor 320 (or ASIC 322 ) substantially simultaneously.
Turning to FIGS. 8A , another example of an AFE 318 of FIGS. 3A through 3C . In this configuration, AFE units 324 - 1 to 324 -(M- 1 ) employ a controller 616 - 1 to 616 -(M- 1 ) to control multiplexer 602 - 1 to 602 -(M- 1 ) and D flip-flop 604 - 1 to 604 -(M- 1 ). AFE unit 324 -M employs shift controller 618 that provides a shift signal SHIFTM to the previous AFE unit 324 -(M- 1 ). As an example of the operation of the AFE 318 of FIG. 8A , a timing diagram of FIG. 8D show the operation of an AFE having three AFE units where each AFE unit has three channels.
In FIG. 8B , an example of controller 616 - 1 to 616 -(M- 1 ) can be seen (hereinafter referred to as 616 ). The shift signal SHIFT from the subsequent AFE unit is provided to a delay element 710 and an XOR gate 708 so that a pulse is produced for the duration of the delay of delay element 710 after reception of a transition of the shift signal SHIFT. Additionally, the output clock signal DCLK is provided to delay element 702 and AND gate 704 so as to produce a pulse for the duration of delay element 702 at the transition from output clock signal DCLK to logic high or “ 1 ”. OR gate 706 generates the clock signal SFTC based on the pulses from the XOR gate 708 and AND gate 704 . D flip flop 716 , delay elements 718 and 724 , AND gates 720 and 722 , counter 710 and comparators 712 and 714 can then generate the select signal SEL base on the pulses from XOR gate 708 and the output clock signal DCLK.
In FIG. 8C , an example of shift controller 618 can be seen. Shift controller 618 generally comprises a reset generator 730 , a counter 726 , count to shift logic 728 , and count to select logic 732 . Based on the output clock signal DCLKM and system clock SCLK, the shift controller is able to generate shift signal SHIFTM and select signal SELM.
Turning to FIGS. 9A and 9B , an example of the AFE unit 318 of FIGS. 3A through 3C can be seen. Here each of the AFE units 324 - 1 to 324 -M are comprised of a first-in-first-out (FIFO) circuit 902 - 1 to 902 -M, a multiplexer 904 - 1 to 904 -M, a D flip-flop 906 - 1 to 906 -M, a controller 908 - 1 to 908 -M, and a clock multiplier 910 - 1 to 910 -M. Each controller 908 - 1 to 908 -M is generally comprised of a ring oscillator 912 , an OR gate 914 , multiplexer 916 , D flip-flop 918 , XOR gate 920 , delay elements 932 and 934 , and AND gate 924 . Ring oscillator 912 that receives a load signal LOAD 1 to LOADM from its clock multiplier 910 - 1 to 910 -M and that is clocked by its output clock signal DCLK 1 to DCLKM. The output from each D flip-flop of ring oscillator 912 is ORed by OR gate 914 to generate a select signal for multiplexer 916 and used as the read signals R 1 to RM for multiplexers 904 - 1 to 904 -M. D flip-flop receives the output from the multiplexer 904 and the respective output clock signal DCLK 1 to DCLKM, to generate the respective control signals UPTOGOUT 1 to UPTOGOUTM. Control signal UPTOGOUTIN (which correspond to control signals UPTOGOUT to UPTOGOUT(M- 1 ) from the previous AFE unit 324 - 1 to 324 -(M- 1 ) is used by XOR gate 920 and delay element 932 to generate clocks signals FCLK 1 to FCLKM for counter 922 . Additionally, AND gate 924 and delay element 934 use the system clock signal SCLK to provide an input for counter 922 . Counter then produces a write signal W 1 to WM. Based on the clock signals FCLK 1 to FCLKM and write signals W 1 to WM, FIFO circuits 902 - 1 to 902 -M (which each employ a write address circuit 926 , a multiplexer 928 , and D flip-flop 930 for each input of its multiplexer 904 - 1 to 904 -M) respectively provide data to its multiplexer 904 - 1 to 904 -M. An example of the operation of the AFE 318 of FIGS. 9A and 9B can be seen in FIG. 9C .
Thus, these systems 300 - 1 , 300 - 2 , and 300 - 2 (and their AFEs 318 ) are able to transmit data without the skew problems present in conventional systems.
Having thus described the present invention by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure and, in some instances, some features of the present invention may be employed without a corresponding use of the other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.
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Conventional analog front ends or AFEs for scanners are implemented using multiple integrated circuits or ICs. As a result, there is typically a problem of skew (due at least in part to manufacturing process variations) for these different ICs in the AFE. Here, an AFE is provided which serializes input data so as to compensate for skew.
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BACKGROUND OF THE INVENTION
[0001] The present invention generally relates to nickel-base alloy compositions, and more particularly to nickel-base superalloys suitable for components requiring a polycrystalline microstructure and high temperature dwell capability, for example, turbine disks of gas turbine engines.
[0002] The turbine section of a gas turbine engine is located downstream of a combustor section and contains a rotor shaft and one or more turbine stages, each having a turbine disk (rotor) mounted or otherwise carried by the shaft and turbine blades mounted to and radially extending from the periphery of the disk. Components within the combustor and turbine sections are often formed of superalloy materials in order to achieve acceptable mechanical properties while at elevated temperatures resulting from the hot combustion gases. Higher compressor exit temperatures in modern high pressure ratio gas turbine engines can also necessitate the use of high performance nickel superalloys for compressor disks, blisks, and other components. Suitable alloy compositions and microstructures for a given component are dependent on the particular temperatures, stresses, and other conditions to which the component is subjected. For example, airfoil components such as blades and vanes are often formed of equiaxed, directionally solidified (DS), or single crystal (SX) superalloys, whereas turbine disks are typically formed of superalloys that must undergo carefully controlled forging, heat treatments, and surface treatments such as peening to produce a polycrystalline microstructure having a controlled grain structure and desirable mechanical properties.
[0003] Turbine disks are often formed of gamma prime (γ′) precipitation-strengthened nickel-base superalloys (hereinafter, gamma prime nickel-base superalloys) containing chromium, tungsten, molybdenum, rhenium and/or cobalt as principal elements that combine with nickel to form the gamma (γ) matrix, and contain aluminum, titanium, tantalum, niobium, and/or vanadium as principal elements that combine with nickel to form the desirable gamma prime precipitate strengthening phase, principally Ni 3 (Al,Ti). Particularly notable gamma prime nickel-base superalloys include René 88DT (R88DT; U.S. Pat. No. 4,957,567) and René 104 (R104; U.S. Pat. No. 6,521,175), as well as certain nickel-base superalloys commercially available under the trademarks Inconel®, Nimonic®, and Udimet®. R88DT has a composition of, by weight, about 15.0-17.0% chromium, about 12.0-14.0% cobalt, about 3.5-4.5% molybdenum, about 3.5-4.5% tungsten, about 1.5-2.5% aluminum, about 3.2-4.2% titanium, about 0.5.0-1.0% niobium, about 0.010-0.060% carbon, about 0.010-0.060% zirconium, about 0.010-0.040% boron, about 0.0-0.3% hafnium, about 0.0-0.01 vanadium, and about 0.0-0.01 yttrium, the balance nickel and incidental impurities. R104 has a nominal composition of, by weight, about 16.0-22.4% cobalt, about 6.6-14.3% chromium, about 2.6-4.8% aluminum, about 2.4-4.6% titanium, about 1.4-3.5% tantalum, about 0.9-3.0% niobium, about 1.9-4.0% tungsten, about 1.9-3.9% molybdenum, about 0.0-2.5% rhenium, about 0.02-0.10% carbon, about 0.02-0.10% boron, about 0.03-0.10% zirconium, the balance nickel and incidental impurities. Another notable gamma prime nickel-base superalloy is disclosed in European Patent Application EP1195446, and has a composition of, by weight, about 14-23% cobalt, about 11-15% chromium, about 0.5-4% tantalum, about 0.5-3% tungsten, about 2.7-5% molybdenum, about 0.25-3% niobium, about 3-6% titanium, about 2-5% aluminum, up to about 2.5% rhenium, up to about 2% vanadium, up to about 2% iron, up to about 2% hafnium, up to about 0.1% magnesium, about 0.015-0.1% carbon, about 0.015-0.045% boron, about 0.015-0.15% zirconium, the balance nickel and incidental impurities.
[0004] Disks and other critical gas turbine engine components are often forged from billets produced by powder metallurgy (P/M), conventional cast and wrought processing, and spraycast or nucleated casting forming techniques. Gamma prime nickel-base superalloys formed by powder metallurgy are particularly capable of providing a good balance of creep, tensile, and fatigue crack growth properties to meet the performance requirements of turbine disks and certain other gas turbine engine components. In a typical powder metallurgy process, a powder of the desired superalloy undergoes consolidation, such as by hot isostatic pressing (HIP) and/or extrusion consolidation. The resulting billet is then isothermally forged at temperatures slightly below the gamma prime solvus temperature of the alloy to approach superplastic forming conditions, which allows the filling of the die cavity through the accumulation of high geometric strains without the accumulation of significant metallurgical strains. These processing steps are designed to retain the fine grain size originally within the billet (for example, ASTM 10 to 13 or finer), achieve high plasticity to fill near-net-shape forging dies, avoid fracture during forging, and maintain relatively low forging and die stresses. In order to improve fatigue crack growth resistance and mechanical properties at elevated temperatures, these alloys are then heat treated above their gamma prime solvus temperature (generally referred to as supersolvus heat treatment) to cause significant, uniform coarsening of the grains.
[0005] Though alloys such as R88DT and R104 have provided significant advances in high temperature capabilities of superalloys, further improvements are continuously being sought. For example, high temperature dwell capability has emerged as an important factor for the high temperatures and stresses associated with more advanced military and commercial engine applications. As higher temperatures and more advanced engines are developed, creep and crack growth characteristics of current alloys tend to fall short of the required capability to meet mission/life targets and requirements of advanced disk applications. It has become apparent that a particular aspect of meeting this challenge is to develop compositions that exhibit desired and balanced improvements in creep and hold time (dwell) fatigue crack growth rate characteristics at temperatures of 1200° F. (about 650° C.) and higher, while also having good producibility and thermal stability. However, complicating this challenge is the fact that creep and crack growth characteristics are difficult to improve simultaneously, and can be significantly influenced by the presence or absence of certain alloying constituents as well as relatively small changes in the levels of the alloying constituents present in a superalloy.
BRIEF DESCRIPTION OF THE INVENTION
[0006] The present invention provides gamma prime nickel-base superalloys and components formed therefrom that exhibit improved high-temperature dwell capabilities, including creep and hold time fatigue crack growth behavior.
[0007] According to a first aspect of the invention, a gamma-prime nickel-base superalloy consists of, by weight, 11.3 to 13.3% cobalt, 12.4 to 15.2% chromium, 2.1 to 2.7% aluminum, 3.6 to 5.8% titanium, 3.5 to 4.5% tungsten, 3.1 to 3.8% molybdenum, 0.0 to 1.2% niobium, 0.0 to 2.3% tantalum, 0.0 to 0.5% hafnium, 0.040 to 0.100% carbon, 0.010 to 0.046% boron, 0.030 to 0.080% zirconium, the balance nickel and impurities, wherein the Nb+Ta content is 0.0-3.5%.
[0008] Other aspects of the invention include various components that can be formed from the alloys described above, particular examples of which include turbine disks and compressor disks and blisks of gas turbine engines.
[0009] A significant advantage of the invention is that the nickel-base superalloys described above provide the potential for balanced improvements in high temperature dwell properties, including improvements in both creep and hold time fatigue crack growth rate (HTFCGR) characteristics at temperatures of 1200° F. (about 650° C.) and higher, while also having good producibility and good thermal stability. Improvements in other properties are also believed possible, particularly if appropriately processed using powder metallurgy, hot working, and heat treatment techniques.
[0010] Other aspects and advantages of this invention will be better appreciated from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a perspective view of a turbine disk of a type used in gas turbine engines.
[0012] FIG. 2 is a table listing a series of nickel-base superalloy compositions initially identified by the present invention as potential compositions for use as a turbine disk alloy.
[0013] FIG. 3 is a table compiling various predicted properties for the nickel-base superalloy compositions of FIG. 2 if subjected to a two-step heat treatment.
[0014] FIG. 4 is a graph plotting creep and hold time fatigue crack growth rate from the data of FIG. 3 .
[0015] FIG. 5 is a table compiling various predicted properties for the nickel-base superalloy compositions of FIG. 2 if subjected to a one-step heat treatment.
[0016] FIG. 6 is a graph plotting creep and hold time fatigue crack growth rate from the data of FIG. 5 .
[0017] FIG. 7 a table listing actual chemistries a series of nickel-base superalloy compositions prepared on the basis of the alloys initially identified in FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
[0018] The present invention is directed to gamma prime nickel-base superalloys, and particular those suitable for components produced by a hot working (e.g., forging) operation to have a polycrystalline microstructure. A particular example represented in FIG. 1 is a high pressure turbine disk 10 for a gas turbine engine. The invention will be discussed in reference to processing of a high-pressure turbine disk for a gas turbine engine, though those skilled in the art will appreciate that the teachings and benefits of this invention are also applicable to compressor disks and blisks of gas turbine engines, as well as numerous other components that are subjected to stresses at high temperatures and therefore require a high temperature dwell capability.
[0019] Disks of the type shown in FIG. 1 are typically produced by isothermally forging a fine-grained billet formed by powder metallurgy (PM), a cast and wrought processing, or a spraycast or nucleated casting type technique. In a preferred embodiment utilizing a powder metallurgy process, the billet can be formed by consolidating a superalloy powder, such as by hot isostatic pressing (HIP) or extrusion consolidation. The billet is typically forged at a temperature at or near the recrystallization temperature of the alloy but less than the gamma prime solvus temperature of the alloy, and under superplastic forming conditions. After forging, a supersolvus (solution) heat treatment is performed, during which grain growth occurs. The supersolvus heat treatment is performed at a temperature above the gamma prime solvus temperature (but below the incipient melting temperature) of the superalloy to recrystallize the worked grain structure and dissolve (solution) the gamma prime precipitates in the superalloy. Following the supersolvus heat treatment, the component is cooled at an appropriate rate to re-precipitate gamma prime within the gamma matrix or at grain boundaries, so as to achieve the particular mechanical properties desired. The component may also undergo aging using known techniques.
[0020] Superalloy compositions of this invention were developed through the use of a proprietary analytical prediction process directed at identifying alloying constituents and levels capable of exhibiting better high temperature dwell capabilities than existing nickel-base superalloys. More particularly, the analysis and predictions made use of proprietary research involving the definition of elemental transfer functions for tensile, creep, hold time (dwell) crack growth rate, density, and other important or desired mechanical properties for turbine disks produced in the manner described above. Through simultaneously solving of these transfer functions, evaluations of compositions were performed to identify those compositions that appear to have the desired mechanical property characteristics for meeting advanced turbine engine needs, including creep and hold time fatigue crack growth rate (HTFCGR). The analytical investigations also made use of commercially-available software packages along with proprietary databases to predict phase volume fractions based on composition, allowing for the further definition of compositions that approach or in some cases slightly exceed undesirable equilibrium phase stability boundaries. Finally, solution temperatures and preferred amounts of gamma prime and carbides were defined to identify compositions with desirable combinations of mechanical properties, phase compositions and gamma prime volume fractions, while avoiding undesirable phases that could reduce in-service capability if equilibrium phases sufficiently form due to in-service environment characteristics. In the investigations, regression equations or transfer functions were developed based on selected data obtained from historical disk alloy development work. The investigations also relied on qualitative and quantitative data of the aforementioned nickel-base superalloys R88DT and R104.
[0021] Particular criteria utilized to identify certain potential alloy compositions included the desire for an alloy with low cycle fatigue (LCF) behavior similar to or better than R88DT, but with improved high temperature hold time (dwell) behavior and with a greater volume percentage of gamma prime ((Ni,Co) 3 (Al,Ti,Nb,Ta)) to promote strength at temperatures of 1400° F. (about 760° C.) and higher over extended periods of time. In addition, certain compositional parameters were identified as potential modifications to the R88DT composition, including higher levels of hafnium for high temperature strength, more optimal boron levels, and additions of tantalum. Alloys within this group are identified herein as alloys 08-03 through 08-10. Finally, regression factors relating to specific mechanical properties were utilized to more narrowly identify potential alloy compositions that might be capable of exhibiting superior high temperature hold time (dwell) behavior, and would not be otherwise identifiable without extensive experimentation with a very large number of alloys. Such properties included ultimate tensile strength (UTS) at 1200° F. (about 650° C.), yield strength (YS), elongation (EL), reduction of area (RA), creep (time to 0.2% creep at 1200° F. and 115 ksi (about 650° C. at about 790 MPa), hold time (dwell) fatigue crack growth rate (HTFCGR; da/dt) at 1300° F. (about 700° C.) and a maximum stress intensity of 25 ksi√ in (about 27.5 MPa√ m), fatigue crack growth rate (FCGR), gamma prime volume percent (GAMMA′ %) and gamma prime solvus temperature (SOLVUS), all of which were evaluated on a regression basis. Units for these properties reported herein are ksi for UTS and YS, percent for EL, RA and gamma prime volume percent, hours for creep, in/sec for crack growth rates (HTFCGR and FCGR), and ° F. for gamma prime solvus temperature. Thermodynamic calculations were also performed to assess alloy characteristics such as phase volume fraction, stability and solvii for gamma prime, carbides, borides and topologically close packed (TCP) phases.
[0022] The process described above was performed iteratively utilizing expert opinion and guidance to define preferred compositions for manufacture and evaluation. From this process, the above-noted series of alloy compositions 08-03 to 08-10 were defined (by weight percent) as set forth in the table of FIG. 2 . For reference, also included in the table are two alloys (08-01 and 08-02) that fall within the composition of R88DT but with minimum or maximum amounts of boron. Regression-based property predictions for the alloys of FIG. 2 are contained in a table in FIG. 3 , and FIG. 4 contains a graph of the hold time fatigue crack growth rate (HTFCGR) and creep data from FIG. 3 . The predictions are based on utilization of a stabilization style two-step age heat treatment at about 1550° F. (about 845° C.) for about four hours, followed by about eight hours at about 1400° F. (about 760° C.).
[0023] For reference, FIG. 4 also contains historical HTFCGR and creep data for R88DT and R104. From the visual depiction of FIG. 4 , it can be seen that a higher boron level appears to improve the HTFCGR behavior of R88DT, though not its creep properties. As to the proposed alloy compositions, it appeared that 08-04, 08-05, and 08-07 may yield improvements in HTFCGR behavior as compared to the historical level for R88DT.
[0024] The alloys of FIG. 2 then underwent further regression-based property predictions based on utilization of a one-step age heat treatment. The resulting property predictions are contained in a table in FIG. 5 , and FIG. 6 contains a graph of the HTFCGR and creep data from FIG. 5 . For reference, FIG. 6 also contains historical HTFCGR and creep data for R88DT and R104. As in the previous predictions based on a two-step heat treatment, from FIG. 6 it can be seen that a higher boron level appears to improve the HTFCGR behavior of R88DT though not its creep properties. As to the proposed alloy compositions, it appeared that 08-04, 08-05, and 08-07 may again yield improvements in HTFCGR behavior as compared to the historical level for R88DT, as well as improvements in creep behavior.
[0025] Alloys based on each of the compositions analyzed and discussed above were then prepared. Actual chemistries (in weight percent) of the prepared alloys are summarized in a table in FIG. 7 . From these alloys, an alloy range was identified to define an alloy with promising properties, and with a narrowly defined range that reflects the properties predicted for the analyzed alloy composition. Broader and narrower ranges for an alloy encompassing alloys 08-03 through 08-10 are summarized in Table I below and characterized in part by (in comparison to R88DT) relatively low chromium levels, relatively high titanium, hafnium and tantalum+niobium levels, and the preference for tantalum over niobium. The “With Ta & Hf” column in Table I is intended to focus on those alloys of 08-03 to 08-10 that contain tantalum and hafnium. In addition to the elements listed in Table I, it is believed that minor amounts of other alloying constituents could be present without resulting in undesirable properties. Such constituents and their amounts (by weight) include up to 2.5% rhenium, up to 2% vanadium, up to 2% iron, and up to 0.1% magnesium.
[0000]
TABLE I
Broader
Narrower
With Ta & Hf
Co
11.3-13.3
11.9-12.7
11.7-12.7
Cr
12.4-15.2
13.1-14.5
12.8-14.5
Al
2.1-2.7
2.2-2.6
2.2-2.6
Ti
3.6-5.8
3.8-5.5
3.8-5.5
W
3.5-4.5
3.7-4.2
3.7-4.2
Mo
3.1-3.8
3.3-3.6
3.2-3.7
Nb
0.0-1.2
0.0-1.1
0.0
Ta
0.0-2.3
0.0-2.2
1.0-2.2
Hf
0.0-0.5
0.0-0.5
0.3-0.5
C
0.040-0.100
0.048-0.067
0.048-0.067
B
0.010-0.046
0.014-0.040
0.014-0.040
Zr
0.030-0.080
0.041-0.070
0.041-0.070
Ni
Balance
Balance
Balance
Nb + Ta
0.0-3.5
0.09-2.2
1.0-2.2
[0026] Though the alloy compositions identified in FIGS. 2 and 7 and the alloys and alloying ranges identified in Table I were all based on analytical predictions, the extensive analysis and resources relied on to make the predictions and identify these alloy compositions provide a strong indication for the potential of these alloys, and particularly the alloy compositions of Table I, to achieve significant improvements in creep and hold time fatigue crack growth rate characteristics desirable for turbine disks of gas turbine engines.
[0027] While the invention has been described in terms of particular embodiments, including particular compositions and properties of nickel-base superalloys, the scope of the invention is not so limited. Instead, the scope of the invention is to be limited only by the following claims.
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Gamma prime nickel-base superalloy and components formed therefrom. The alloy contains, by weight, 11.3 to 13.3% cobalt, 12.4 to 15.2% chromium, 2.1 to 2.7% aluminum, 3.6 to 5.8% titanium, 3.5 to 4.5% tungsten, 3.1 to 3.8% molybdenum, 0.0 to 1.2% niobium, 0.0 to 2.3% tantalum, 0.0 to 0.5% hafnium, 0.040 to 0.100% carbon, 0.010 to 0.046% boron, 0.030 to 0.080% zirconium, the balance nickel and impurities, wherein the Nb+Ta content is 0.0-3.5%.
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FIELD OF THE INVENTION
The present invention generally relates to apparatus and methods for managing air flow during the manufacture of nonwoven webs and laminates.
BACKGROUND OF THE INVENTION
Meltblowing and spunbond processes are commonly employed to manufacture nonwoven webs and laminates. With meltblowing, a molten thermoplastic is extruded from a die tip to form a row of filaments or fibers. Converging sheets or jets of hot air impinge upon the fibers as they are extruded from the die tip to stretch or draw the fibers, thereby reducing the diameter of the fibers. The fibers are then deposited in a random manner onto a moving collector belt to form a nonwoven web.
With spunbond processes, continuous fibers are extruded through a spinneret. Air is directed at the extruded fibers to separate and orient them. The fibers are collected onto a moving collector belt. At a downstream location, the fibers are consolidated by passing the layer of fibers through compacting roller, for instance. The spunbond process frequently utilizes quenching air to cool the extruded before they contact the collector belt.
Large volumes of air are used during both the meltblown and spunbond process. Moreover, much of the air is heated and moving at very high velocities, sometimes approaching the speed of sound. Without properly collecting and disposing of the process air, the air would likely disturb personnel working around the manufacturing apparatus and other nearby equipment. Further, the heated air would likely heat the surrounding area in which the nonwoven is being produced. Consequently, attention must be paid to collecting and disposing of this process air.
Managing the process air is also important to producing a homogeneous nonwoven web across the width of the web. The homogeniety of the final nonwoven web depends greatly on the air flow around the fibers as they are deposited onto the collector belt. For instance, if the air flow velocity is not uniform in the cross-machine direction, the fibers will not be deposited onto the collector belt uniformly, yielding a non-homogeneous nonwoven web.
Various air management systems have been used to collect and dispose of the process air. One particular air management system uses a collecting duct situated below a perforated collector belt to collect and dispose of the process air. An air moving device, such as a fan or vacuum pump, is connected to the collecting duct to actively draw the air into the collecting duct. The collecting duct is comprised of a plurality of a smaller air passageways arranged side-by-side in a rectangular grid. The grid includes a central row of air passageways extending across the machine width and upstream and downstream air passageways flanking either side of the central row. The central row of air passageways is disposed directly below the extrusion die in what is commonly referred to as the forming zone. Each air passageway includes an inlet and an outlet with a 90 degree elbow in between. An air moving device is operatively connected to each outlet to draw the process air into the individual inlets.
As mentioned above, the air flow velocity of the process air around the collector belt should be uniform, especially in the machine direction at the forming zone, to form a homogeneous nonwoven web. Achieving a uniform air flow velocity, however, has proven challenging. In the collecting duct described above, moveable dampers are associated with each outlet of the air passageways. To achieve uniform air flow velocity with this collecting duct, an technician must manually manipulate each damper until the air flow velocity is sufficiently uniform. In some instances, the technician may be unable to achieve a uniform air flow velocity no matter how much time and effort is spent adjusting the dampers. Moreover, the dampers must be readjusted each time a different fiber material or process air flow rate is used. Thus, the operator must readjust the dampers virtually every time the process is started or an operating condition is changed. The readjustment process takes a great deal of time and may ultimately yield a nonuniform air flow velocity regardless of how the moveable dampers are adjusted.
What is needed, therefore, is an air management system that can collect and dispose of the process air so as to produce a uniform air flow velocity at the collector belt, especially around the forming zone. The air management system should be designed such that dampers and other manual controls are not necessary, even over a wide range of process air flow rates.
SUMMARY OF THE INVENTION
The present invention provides a melt spinning system and, more particularly, a melt spinning and air management system that overcomes the drawbacks and disadvantages of prior air management systems. The air management system of the invention includes at least one air handler for collecting air discharged from a melt spinning apparatus. In accordance with a general objective of the invention, the air handler produces a uniform air flow velocity in at least the cross-machine direction as the air enters the air handler. This is accomplished without the typical adjustable baffles and dampers required in the past. The air handler generally includes an outer housing having walls defining a first interior space. One of the walls has an intake opening for receiving the discharge air from the melt spinning apparatus. Another wall has an exhaust opening for discharging the air collected by the air handler. The intake opening is in fluid communication with the first interior space. An inner housing is positioned within the first interior space and has walls defining a second interior space. At least one of the walls of the inner housing has an opening. The first interior space communicates with the second interior space through the opening. The second interior space is in fluid communication with the exhaust opening.
In one aspect of the invention, the opening between the first interior space and the second interior space is an elongate slot and preferably includes a center portion having a wider dimension than the end portions thereof. The intake opening is positioned at the top of the outer housing, and the slot in the inner housing is disposed proximate to the bottom of the outer housing. The outer housing can further include a filter member for filtering particulates from the air discharged by the melt spinning apparatus.
The invention further provides an air management system including three air handlers. One air handler is positioned directly below the melt spinning apparatus in a forming zone. Another air handler is positioned upstream of the forming zone, and the other air handler is positioned downstream of the forming zone. The widths of the intake opening of the upstream and downstream air handlers in the machine direction are respectively greater than the width of the intake opening of the air handler positioned below the forming zone. The upstream and downstream air handlers collect air which spills over, i.e., not collected, from the air handler below the forming zone.
Various additional advantages and features of the invention will become more readily apparent to those of ordinary skill in the art upon review of the following detailed description taken in conjunction with the accompanying drawings.
DETAILED DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic plan view of a two-station production line incorporating the air management system of the invention;
FIG. 2 is a perspective view of the two-station production line of FIG. 1 with the collector belt removed for clarity;
FIG. 3 is a perspective view of the air management system of FIG. 1;
FIG. 4 is a partially disassembled perspective view of the forming zone air handler of FIG. 3;
FIG. 5 is a cross sectional view of the forming zone air handler in FIG. 4 taken along lines 5 — 5 ;
FIG. 6 is a plan view of the forming zone air handler bottom in FIG. 4 taken along lines 6 — 6 ;
FIG. 7 is a partially disassembled perspective view of one of the spillover air handlers of FIG. 3;
FIG. 8 is a perspective view of another embodiment of the air management system of the invention; and
FIG. 9 is cross sectional perspective view of the air management system in FIG. 8 taken along lines 9 — 9 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIG. 1, a two-station production line 10 is schematically illustrated. The production line 10 incorporates an air management system 12 of the invention at both an upstream station 14 and a downstream station 16 . While the air management system 12 has been illustrated in conjunction with the two-station production line 10 , the air management system 12 is generally applicable to other production lines having a single station or a plurality of stations. In a single station production line, the nonwoven web can be manufactured using any one of a number of process, such as a meltblowing process or a spunbond process.
In a multiple-station production line, a plurality of nonwoven webs can be manufactured to form a multiply laminate. Any combination of meltblowing and spunbonding processes may be used to manufacture the laminate. For instance, the laminate may include only nonwoven meltblown webs or only nonwoven spunbond webs. However, the laminate may include any combination of meltblown webs and spunbond webs.
The two-station production line 10 in FIG. 1 is shown forming a two-ply laminate 18 with a meltblown layer or web 20 on the bottom and a spunbond layer or web 22 on the top. The two-ply laminate 18 is consolidated downstream using compacting rolls, for example. The upstream station 14 includes a melt spinning assembly 24 with a metblowing die 26 and the downstream station 16 includes a melt spinning assembly 28 with a spunbond die 30 .
To form the meltblown web 20 , the meltblowing die 26 extrudes a plurality of thermoplastic filaments or fibers 32 onto a collector such as a belt 34 . It will be appreciated that the collector 34 may be any other substrate, such as a substrate used as a component in the manufacture of a product. Converging sheets or jets of hot air, indicated by arrows 36 , from the meltblowing die 26 impinge upon the fibers 32 as they are extruded to stretch or draw the fibers 32 . The fibers 32 are then deposited in a random manner onto the collector moving belt 34 from right to left to form the meltblown web 20 . The collector belt 34 is perforated to permit the air to flow through the collector belt 34 and into the air management system 12 .
Similarly, to form the spunbond web 22 , the spunbond die 30 extrudes a plurality of thermoplastic filaments or fibers 38 onto the meltblown web 20 being transported by the moving collector belt 34 . Hot air, indicated by arrows 40 , from the spunbond die 30 impinges upon the fibers 38 to impart rotation to the fibers 38 . Additionally, air ducts 42 direct quenching air onto the extruded fibers 38 to cool the fibers 38 before they reach the meltblown web 20 . As with the upstream station 14 , the air at downstream station 16 passes through the nonwoven web 20 and the collector belt 34 and into the air management system 12 .
Several cubic feet of air per minute per inch of die length flow through each station 14 , 16 during the manufacture of the meltblown and spunbond webs 20 , 22 . The air management system 12 of the invention efficiency collects and disposes of the air from through the stations 14 , 16 . More importantly and as will be discussed in greater detail below, the air management system 12 collects the air such that the air has a substantially uniform flow velocity at least in the cross-machine direction as the air passes through the collector belt 34 . Ideally, the fibers 32 , 38 are deposited on the collector belt 34 in a random fashion to form the meltblown and spunbond webs 20 , 22 which are homogeneous. If the air flow velocity through the collector belt 34 is nonuniform, the resultant web will likely not be homogeneous.
With reference to FIG. 2, transport structure 50 of the two-station production line 10 of FIG. 1 is shown. While the two-station production line 10 includes two air management systems 12 , the following description will focus on the air management system 12 associated with the upstream station 14 . Nevertheless, the description will be equally applicable to the air management system associated with downstream station 16 .
With further reference to FIGS. 2 and 3, air management system 12 includes three discrete air handlers 52 , 54 , 56 disposed directly below the collector belt 34 . Air handlers 52 , 54 , 56 include intake openings 58 , 60 , 62 and oppositely disposed exhaust openings 64 , 66 , 68 . Individual exhaust conduits 70 , 72 , 74 are connected respectively to exhaust openings 64 , 66 , 68 . Exhaust conduit 70 , which is representative of exhaust conduits 72 , 74 , is comprised of a series of individual components: first elbows 76 , second elbows 78 , elongated portion 80 , down portion 82 , and third elbow 84 . A series of parallel guide vanes 86 extend through down portion 82 and third elbow 84 . In operation, a variable speed fan (not shown) or any other suitable air moving device is connected to third elbow 84 to draw the air through the air management system 12 .
With continued reference to FIGS. 2 and 3, air handler 54 is located directly below the forming zone, i.e., the location where the fibers contact the collector belt 34 . As such, air handler 54 collects and disposes of the largest portion of air used during the extrusion process. Upstream air handler 56 and downstream air handler 52 collect spill over air which air handle 54 does not collect.
With reference now to FIGS. 4-6, forming zone air handler 54 includes an outer housing 94 which includes intake opening 60 and oppositely disposed exhaust openings 66 . Intake opening 60 includes a perforated cover 96 with a series of apertures through which the air flows. Depending of the manufacturing parameters, air handler 54 may be operated without using the perforated cover 96 at all. Air handler 54 further includes an inner housing or box 98 which is suspended from the outer housing 94 by means of spacing members 100 which include a plurality of openings 101 therein. Two filter members 102 , 104 are selectively removable from air handler 54 so that they may be periodically cleaned. The filter members 102 , 104 slide along stationary rail members 106 , 108 . Each of these filter members 102 , 104 are perforated with a series of apertures through which the air flows.
The inner box 98 has a bottom panel 110 that includes an opening such as slot 112 with ends 114 , 116 and a center portion 118 . As illustrated in FIG. 6, slot 112 extends substantially across the width, i.e., the cross-machine direction, of the inner box 98 . The slot 112 is narrow at ends 114 , 116 and widens at center portion 118 . The slot 112 could be formed from one or more openings of various shapes, such as round, elongate, rectangular, etc.
The shape of slot 112 influences the air flow velocity in the cross machine direction at the intake opening 60 . If the shape of the slot 112 is not properly contoured the air flow velocities at the intake opening 60 may vary greatly in the cross machine direction. The particular shape shown in FIG. 6 was determined through an iterative process using a computational fluid dynamics (CFD) model which incorporated the geometry of the air handler 54 . A series of slot shapes were evaluated at intake air flow velocities ranging between 500 to 2500 feet per minute. After the CFD model analyzed a particular slot shape, the air flow velocity profile in the cross machine direction was checked. Ultimately, the goal was to choose a shape for the slot 112 which provided a substantially uniform air flow velocity in the cross machine direction at intake opening 60 . Initially, a rectangular slot 112 was evaluated, yielding air flow velocities in the cross machine direction at the intake opening 60 which varied by as much as twenty percent. With the rectangular slot 112 , the air flow velocities near the ends of the intake opening 60 were greater than the air flow velocities approaching the center of the intake opening 60 . To address this uneven air flow velocity profile, the width of ends 114 , 116 was reduced relative to the width of the center portion 118 . After approximately five iterations, the shape of slot 118 is FIG. 6 was chosen. That slot shape yields air flow velocities in the cross machine direction at the intake opening 60 which varied by ±5.0%.
With specific reference to FIG. 5, air enters through perforated cover 96 and passes through perforated filter members 102 , 104 as illustrated by arrows 120 . The air passes through the gap between the inner box 98 and the outer housing 94 as illustrated by arrows 122 . The air then enters the interior of inner box 98 through slot 112 as illustrated by arrows 124 . Finally, the air exits the inner box 98 through exhaust opening 66 as illustrated by arrows 126 and then travels through exhaust conduit 72 . The openings 101 in spacing members 100 allow the air to move in the cross-machine direction to minimize transverse pressure gradients.
Generally, air handlers 52 , 56 have a similar construction and air flow path as air handler 54 . However, as FIG. 3 illustrates, air handlers 52 , 56 have much wider, i.e, in the machine direction, intake openings 58 , 62 than intake opening 60 of air handler 54 . The width of the these intake openings 58 , 62 may vary depending on the particular manufacturing parameters. The following discussion of air handler 52 is equally applicable to air handler 56 . Thus, with specific reference to FIG. 7, air handler 52 includes an outer housing 136 which includes intake opening 58 and exhaust openings 64 . Intake opening 58 includes a perforated cover 137 with a series of apertures through which the air flows. Depending on the manufacturing parameters, air handler 52 may be operated without using perforated cover 137 at all. Air handler 52 further includes an inner housing or box 138 which is suspended from the outer housing 136 by means of spacing members 140 which include a plurality of openings 142 therein. Unlike air handler 54 , air handlers 52 , 56 do not include filter members 102 , 104 .
The inner box 138 includes a bottom panel 144 with a slot 146 which is configured similarly to slot 112 . Slot 146 includes ends 148 , 150 and center portion 152 . Like slot 112 , the width at center portion 152 is greater than the width at ends 148 , 150 .
As mentioned above, the air flow path through air handler 52 is similar to the air flow path in air handler 54 . Specifically, air enters through perforated cover 137 as illustrated by arrows 154 and passes through the gap between the inner box 138 and the outer housing 136 as illustrated by arrows 156 . The air then enters the interior of inner box 138 through slot 146 as illustrated by arrow 158 . Finally, the air exits the inner box 138 through exhaust opening 64 as illustrated by arrow 160 and then travels through exhaust conduit 70 . The openings 142 in spacing members 140 allow the air to move in the cross-machine direction to minimize transverse pressure gradients.
Another embodiment of the air management system of the invention is shown generally as 170 in FIGS. 8 and 9. As described above, air management system 12 includes three separate and discrete air handlers 52 , 54 , 56 . In contrast, air management system 170 includes air handlers 172 , 174 , 176 which share common walls to form a unitary device. Air handler 174 is placed under the forming zone of the production line to collect the majority of the process air and air handlers 172 , 176 collect spill over air which air handler 174 does not collect. Each air handler 172 , 174 , 176 includes an intake opening 178 , 180 , 182 over which a single perforated cover 184 is placed. A plurality of individual perforated covers may be used in place of the single perforated cover 184 . Each air handler 172 , 174 , 176 further includes exhaust openings 186 , 188 , 190 oppositely disposed on either end of the respective air handlers 172 , 174 , 176 . Separate exhaust conduits (not shown) similar to exhaust conduits 70 , 72 , 74 connect to exhaust openings 186 , 188 , 190 to pull the air out of the air handlers 172 , 174 , 176 . Air handler 174 may include a filter member having a perforated surface through which the incoming air flows.
Air handlers 172 , 174 , 176 include inner boxes 192 , 194 , 196 and sidewalks 198 , 200 , 202 , 204 . Spacing members 206 , 208 , 210 hold inner boxes 192 , 194 , 196 away from sidewalks 198 , 200 , 202 , 204 . Inner boxes 192 , 194 , 196 include bottom panels 212 , 214 , 216 having slots 218 , 220 , 222 . The airflow path through air handlers 172 , 174 , 176 is similar to the air flow path in air handlers 52 , 54 , 56 . The air flow path through air handler 174 is represented by arrows 224 .
While the present invention has been illustrated by a description of various preferred embodiments and while these embodiments have been described in considerable detail in order to describe the best mode of practicing the invention, it is not the intention of applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications within the spirit and scope of the invention will readily appear to those skilled in the art. The invention itself should only be defined by the appended claims, wherein we claim:
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An air handler for collecting air discharged from a melt spinning apparatus. The air handler includes an outer housing having walls defining a first interior space. One of the walls has an intake opening for receiving the discharge air. Another wall has an exhaust opening for discharging the air. The intake opening is in fluid communication with the first interior space. An inner housing is positioned within the first interior space and has walls defining a second interior space. At least one of the walls of the inner housing has an opening. The first interior space communicates with the second interior space through the opening. The second interior space is in fluid communication with the exhaust opening.
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FIELD OF INVENTION
This invention relates to novel vanadium phosphate materials useful to provide microporous structures and to the methods for the preparation of such materials.
BACKGROUND OF THE INVENTION
There is currently intense interest in the chemistry of the vanadium oxide phosphate system because the system is capable of providing networks of connected vanadium and phosphorus polyhedra with a diversity of structures. This structural diversity is associated in part with the ability of vanadium oxygen coordination polyhedra to adopt tetrahedral, square pyramidal and octahedral geometries and to aggregate into larger cores by condensation of polyhedra through shared oxygen atoms. Further condensation with phosphate tetrahedra, such as PO 4 3- , HPO 4 2- and H 2 PO 4 -1 results often in complex polyhedral networks.
Moreover, when cationic templates are introduced, polyhedral framework solids with tunnels, cages and micropores may be isolated. Such solids offer considerable promise since they make possible microporous framework solids, capable of shape selective absorption like the zeolites and aluminophosphates, that are useful as catalysts or molecular sieves.
Generally in the past with vanadium oxide phosphate systems, such templates have involved inorganic materials but the use of such materials has limited the size and shape of the micropores that can be realized. Of greater potential interest would be framework structures that could be assembled about templates of large size organic molecules that could later be removed, either by ion exchange or thermal methods, to leave pores of size comparable to those of the organic template molecules.
To this end, recently, hydrothermal self-assembly syntheses have been used to prepare microporous, octahedral framework molydenum phosphates formed about organic cationic templates, but these molydenum phosphate frameworks with organic cationic templates are of restricted applicability and there is interest in structures involving other metal phosphate compositions, such as vanadium phosphates, to increase the range of options.
SUMMARY OF THE INVENTION
An object of the present invention is a vanadium phosphate crystalline material that can be formed hydrothermally by self assembly of ordered arrays about a template of organic molecules such that when the template is removed from the framework there remains a vanadium phosphate framework with micropores of size and shape adapted to sorb desired molecules.
To this end, the invention provides novel crystalline vanadium phosphate compositions that can be made microporous and that can advantageously be prepared by the self assembly of structurally simple precursors. The compositions of the invention are embraced within the generic formula
(A).sub.a (B).sub.b (H.sub.3 O.sup.+).sub.c [(V).sub.d (O).sub.e (OH).sub.f (H.sub.2 PO.sub.4).sub.g (HPO.sub.4).sub.h (PO.sub.4).sub.i (H.sub.2 O).sub.i ].xH.sub.2 O
where A is one or more metals chosen from the group of alkali metals or alkaline-earth metals consisting of Li, Na, K, Rb, Cs, Mg, Ca, Sr, and Ba; B is an organic template of the form R 4 N in which R is one or more compositions chosen from the group consisting of H, C n H 2n+1 , C n H 2n NQ 3 where n has a value equal to or less than 4 and Q is either H or C n H 2n+1 ; and each of a and d has a value greater than zero, each of b, c, e, f, g, h, i, j, and x has a value equal to or greater than zero, but at least one of g, h and i has a value greater than zero.
The structure of such compositions, as determined by x-ray diffraction, can be grossly described as a three dimensional covalently bonded framework built up from VO 6 octahedra and/or VO 5 square pyramids, and phosphate tetrahedra, such as PO 4 3- , HPO 4 2- and H 2 PO 4 1- . For such structures species of alkylammonium or alkyldiammonium ions have proven of particular interest for use as a cationic organic template, but it is anticipated that other organic ions should also be able serve the same function.
One such composition is K 4 [(CH 3 ) 2 NH 2 ][V 10 O 10 (OH) 4 (PO 4 ) 7 (H 2 O) 2 ].4H 2 O (hereinafter composition (1)), and it is characterized by chiral double helices that are formed from interpenetrating spirals of vanadium oxo pentameters bonded together by P 5+ about a cationic organic template and the K + cation. The double helices are in turn intertwined with each other in a manner that generates voids that include relatively large tunnels that enclose dimethylammonium ions. This composition was prepared by hydrothermal treatment of a solution comprising various inorganic materials and organic dimethylamine which served to provide the template about which the vanadium phosphate structure was formed as a framework.
An example of a vanadium phosphate composition that was formed about an ethylenediammonium template material is
[H.sub.3 NCH.sub.2 CH.sub.2 NH.sub.3 ].sub.2.5 [V(H.sub.2 O).sub.2 V.sub.8 O.sub.8 (OH).sub.4 (HPO.sub.4).sub.4 (H.sub.2 O).sub.2 ].2H.sub.2 O
hereinafter to be referred to as composition (2).
Other examples of vanadium phosphate compositions including organic templates that were obtained include [H 3 NCH 2 CH 2 CH 2 NH 3 ][V 3 O 3 (OH) 2 (PO 4 ) 2 (H 2 O) 2 ] to be designated as composition (3) and K[H 3 NCH 2 CH 2 CH 2 NH 3 ][V 3 O 3 (PO 4 ) 3 ] to be designated as composition (4).
The invention will be better understood from the following more detailed specification taken with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the structure of one of the two structurally similar, crystallographically independent vanadium oxo pentameters.
FIG. 2A and FIG. 2B each shows from a different angle perpendicular to the spiral axis a portion of the chiral double helix structure of composition (1) that forms one example of the invention.
FIG. 3 illustrates schematically how the double helices shown in FIGS. 2A and 2B intergrow.
FIGS. 4A and 4B are projections of the unit cell contents parallel to the tetragonal a and b axes, respectively.
FIGS. 5A and 5B are views of the polyhedra ring building block of composition (2) that forms another example of the invention viewed parallel to and perpendicular to the plane of the ring, respectively.
DETAILED DESCRIPTION OF THE INVENTION
A process that gave greater than 85 percent yield of monophasic, dark blue tetragonal pyramids of composition (1) was as follows. There was prepared a mixture of KVO 3 , V, H 3 PO 4 , CH 3 PO 3 H 2 , (CH 3 ) 2 NH, and H 2 O in a mole ratio approximately of 2.35:1:10.2:3.3:8:1140 respectively, and it was maintained at about 200° C. for 4 days. The composition (1) was self-assembled. While the above set of conditions provided the highest yield, the growth process appeared not to be critically dependent on any particular parameter and yields in excess of fifty percent were obtained over a wide range of temperatures, times and mole ratios. Yield of at least fifty percent could be achieved when the KVO 3 was in the mole ratio range of between 1.48 and 2.37, the H 3 PO 4 between 5.9 and 17.2, the CH 3 PO 3 H 2 between 2.43 and 5.9, the dimethylamine between 5.94 and 13.2 and the H 2 O between 500 and 1900. Also the heating could be done in the range between 185° C. and 235° C. and this range generally required times between 3 and 6 days for good yields. Excessively long periods tended to result in dissolution of the grown material. The cation template can be removed, leaving the vanadium phosphate framework, by heating, as for example to 650° C., in a heating step that reaches such temperature by increasing the temperature at the rate of about 10 degrees Centigrade a minute, typically in a nitrogen atmosphere. It also should be feasible to remove the cations by an appropriate ion exchange process.
It was also possible to make the same material with a yield of at least 50 percent with the following set of reagents, KVO 3 , V 2 O 5 , V, H 3 PO 4 , DMA (dimethylamine), and H 2 O in approximately the following mole ratio, 0.67:0.83:1:1:0.13:222 respectively, and the DMA concentration could be increased to 0.26 with little effect.
The structure of composition (1) was determined by single-crystal x-ray diffraction and consists of a three-dimensional covalently bonded framework built up from VO 6 octahedra, VO 5 square pyramids, and PO 4 tetrahedra. Composition (1) crystallizes in the space group P4 3 (or its enantiomorph P4 1 ), and therefore the crystals are enantiomorphic and the unit cell contents are chiral. The fundamental building blocks are two structurally similar, crystallographically independent vanadium oxo pentamers, one of which is shown in FIG. 1. The pentameter includes the five vanadium atoms 11, the four phosphorus atoms 12, two hydroxyls 13 and the remainder (not numbered) oxygen atoms. Although each pentamer may appear to possess 1 symmetry, examination of the V--O distances shows that actually there is no symmetry present because of the alternation of long V--O (2.4 Å) and short V═O(1.7 Å) contacts along the seven-atom central V--O backbone of the pentamer. This backbone has a short V═O bond at one end and a long V--O bond to an H 2 O ligand at the other. The pentamers have a V--O--V backbone containing four V--O--V and two V--OH--V bonds. The connectivity is such that there is a central trimer of three VO 6 octahedra, with the central octahedron sharing trans corners with the two outer octahedra. Each of two outer octahedra of the trimer share an edge with two VO 5 square pyramids. These pentamers are arranged so as to form spirals, with four pentamers per spiral of unit cell length along [001].
The spirals in turn are intertwined to give the two strands of a double helix as shown in FIG. 2A with one strand composed of V1-V5 and the other strand V6-V10. These helices are very unusual in that the two directions parallel to the axis of the helix are unequivalent and, because of the tetragonal space group, the helices appear to have a square cross section when viewed in projection down [001]. The perpendicular distance of the V--O backbone within the spiral to the central axis of the spiral varies as a function of the z axis coordinate of the unit cell, which results in what appears to be protruding major and minor loops when the helix is viewed from various angles perpendicular to the spiral axis (FIG. 2B). There are seven different types of phosphorus 5+ cations in the unit cell. Some P5+ serve to join the pentamers and some to connect the strands to one another to form the helix, whereas others bond one double helix to another.
These strands and double helices intergrow with one another in an extremely complicated fashion as is illustrated schematically in FIG. 3. The essence of the symmetry is represented by the two sets of five unique V atoms and P1. The loops protruding from each double helix are quite large. Within a given unit cell, portions of the two crystallographically independent strands of each double helix undergo an excursion into the adjacent unit cells on either side of the original unit cell and then turn 90° and form the minor loop before returning to a point one unit cell translation in away but with the same x and y coordinates. When the helix forms the largest loops, another strand from another helix goes through the open loop. This interweaving of the strands and helicies gives rise to a three-dimensional array of interconnected braids.
This connectivity of the covalently bonded vanadium phosphate framework generates relatively small cavities and a topologically unusual array of relatively large tunnels that contain the K + and (CH 3 ) 2 NH 2 + cations, respectively. As shown in FIG. 4A and B, which are projections of the unit cell contents parallel to the tetragonal a and b axes, respectively, the tunnels that are filled with the dimethylammonium cations run parallel both to [100] at 1/4 and 3/4 in c axis and parallel to [010] at 0 and 1/2, but at no point do the two types of tunnel intersect. In fact, the atoms that are the "ceiling" of one tunnel form the "floor" of the perpendicular tunnel above it. The shorter contacts of the less polar organic cations to the framework are the vanadyl (V═O) groups. The K + cations lie in more polar regions of the structure and are coordinated to the solvate water. Based on the earlier observations in several molybdenum phosphates in which nonpolar organic cations were associated with less polar molybdenyl (Mo═O), regions of the framework and polar inorganic cations (e.g. Na + , NH 4 + , H 3 O 30 ) were near the phosphate regions of the framework, we believe that hydrophobichydrophilic interactions are an important factor in understanding how these mixed organic-inorganic system crystallize.
Investigation of the magnetic properties of composition (1) shows that the material is paramagnetic at room temperature and that there are ten unpaired electrons per V10 formula unit consistent with the bond strength-bond length calculations, and characteristic of square pyramidal or distorted octahedral geometry of the vanadium, both of which indicate all ten V are d 1 V 4+ . At lower temperatures there is a decrease in the magnetic moment of material (1), from 163 μ B per V at room temperature to 1.01 μ B at 2.5K, due to low dimensional antiferromagnetic interactions. The preparation of this open framework vanadium phosphate synthesized with organic templates that displays chirality suggests several possible applications, as in catalysis and as a molecular sieve. The tunnels in which the (CH 3 ) 2 N H 2 + cations reside are not exactly cylindrical and the atoms responsible for the minimum constrictions of 6.9 and 8.1 Å (atom-to-atom distances) do not define planes that are perpendicular to the axis of the tunnel. Some of the V atoms have potentially removable aquo ligands, which should provide shape-selective absorption. In particular, one can expect absorption or catalysis that would discriminate between enantiomers. All because composition (1) is a rare example of a material that is both chiral and strongly magnetic, it should have applications that depend on the existence of interactions between polarized light and an internal or external magnetic field.
Another example with different reagents included V 2 O 4 , H 3 PO 4 , KCl, DMA, and H 2 O approximately in the mole ratio of 1:6.1:1.66:4.3:750. Again the preferred growth condition was 4 days at 200° C.
Composition (2) was prepared by combining V 2 O 5 , V (325 mesh) CH 3 PO 3 H 2 , H 3 PO 4 , H 2 N(CH 2 ) 2 NH 2 and H 2 O in a mole ratio of 0.95:1:2.79:7.33:6.73:1056 and heating the mixture for 4 days at 200° C. In particular, material (2) forms as dark blue, diamond-shaped plates with about an 80 per cent yield based on the total vanadium, and the by product was an amorphous white product.
The structure of material (2) was also investigated by x-ray diffraction. The structure is constructed from corner-sharing V(IV) square pyramids, V(III) octahedra and (PO 4 ) 3- and (HPO 4 ) 2- tetrahedra and employs a number of structural motifs common to V--P--O phases. There are two types of binuclear V(IV) units in the V(IV)--P--O lamellar framework: V 2 (μ 2 -PO 4 ) 2 and V 2 (μ-OH) (μ 2 -PO 4 ) groups. The overall structure may be grossly described as undulating layers, built up from corner sharing (via a μ 2 -OH group) V(IV) square pyramids and HPO 4 2- and PO 4 3- tetrahedra, connected together by V(III) octahedra. The fundamental building blocks of the layers are rings containing eight polyhedra: four VO 5 square pyramids, two HPO 4 2- and two PO 4 3- tetrahedra as shown in FIG. 5A. These rings are amphiphilic with the four less polar V═O vanadyl groups on one side of the plane defined by the V and P atoms and four P--O groups on the opposite face of the ring (FIG. 5B). Two of these P--O groups are strongly polar P--OH groups and two are P--O moieties that are bound to the interlamellar diaquo V(III) center. The layers are built up from these domed, amphiphilic rings. Each ring exhibits the V═O and P--OH groups in an anti orientation and is surrounded by six other rings: two with V═O up/P--OH down along b axis and four with V═O down/P--OH up. Within each layer, strips running along b axis formed from rings with the V═O up/P--OH down alternate with parallel stripx of V═O down/P--OH up. The two types of rings in the parallel strips are offset from one another by 1/2b. This up-down connectivity of the domed rings give rise to the undulations in the layers. The connectivity of the rings give rise to large holes (ca. 6.2 Å-7.2 Å atom to atom diameter) within the layers.
The three dimensional structure is formed by the connection of these layers through V(III) (H 2 O) 2 centers. These V(III) atoms serve to produce elliptical cross sections in the large cavities by drawing together the polar regions of the layer while the nonpolar regions of the layers are pushed away from the organic cations. The atom-to-atom, V(III) to V(III), distance of the long axis of the elliptical channels is the unit cell length along the c axis of 18.4 Å. The polar NH 3 + ends of the organic cations and the H 2 O of crystallization are situated within the cavities so as to maximize H-bonded interactions with the polar P--OH and V(H 2 O) 2 portions of the framework while the less polar carbon backbones of the organic templates are associated with the V═O groups.
Composition (3) was prepared by reacting VO 2 , H 3 PO 4 , CH 3 PO 3 H 2 , 1,3 diaminopropane and H 2 O in approximately the following mole ratios 1:3:1:2.4:370. The reactants were heated for four days at about 200° C. to provide about a forty percent ratio of material (3) and side products. A sixty five percent yield was obtained by reacting V 2 O 5 , V, H 3 PO 4 , CH 3 PO 3 H 2 , 1,3 diaminopropane and water in approximately the following mole ratios, 2.4:1:10:3.4:8.8:1390. Heating was done at 200° C. for 3 days.
Composition (4) was prepared in about 45 percent yield by reacting KVO 3 , V, H 3 PO 4 , CH 3 PO 3 H 2 , 1,3 diaminopropane and H 2 O in approxiately the following mole ratios 2.4:1:10:3.3:6.2:1250 for four days at 200° C.
As was earlier found in the case of the microporous molybdenum phosphates, hydrophilic-hydrophobic interactions appear to be an important factor in determining how this type of mixed organic-inorganic system can crystallize.
The successful incorporation of a relatively large organic template into a V--P--O solid phase characteristic of the invention demonstrates several emerging themes in the development of synthetic routes to such designed materials. Since the structures adopted by V--P--O phases are sensitive to the nature of the templates introduced, hydrophobic/hydrophilic interactions may be exploited in the self assembly of the frameworks by proper choice of templating inorganic and organic cations. Incorporation of both inorganic and organic cations into the V--P--O framework induces segregation of polar and nonpolar regions with the production of large incipient void volumes. Furthermore, V--P--O phases with 1:1 or lower V(IV,V):P ratios appear to be too polar to accommodate the organic template. Consequently, the introduction of reduced vanadium centers, specifically V(III), may provide a framework of reduced polarity, while dramatically expanding the structural chemistry of the system by providing the greater flexibility.
Accordingly, it should be understood that the specific vanadium phosphate compositions described are merely illustration of the general principles of our discovery, and that various modified versions of such materials can be prepared consistent with the principles described. In particular, from previous work with vanadium phosphate compositions, it can be expected that various other alkali and alkaline-earth metals can be substituted for the potassium in the potassium vanadium phosphates described.
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A new class of vanadium phosphate materials has been created using hydrothermanl self-assembly techniques. Of particular interest is that these materials comprise a vanadium phosphate framework structure about an organic template that after removal leave a microporous structure. These materials typically are produced by a reaction in an aqueous solution that includes one or more phosphate sources, one or more vanadium or vanadium oxide sources, an alkali metal or alkali-earth metal sources, and an organic amine or diamine templating agent.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser. No. 10/091,154, filed Mar. 5, 2002, now U.S. Pat. No. 6,759,576. The aforementioned application is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
This invention is in the field of watermelon breeding, specifically relating to diploid watermelons used to pollinate triploid watermelon plants for the commercial production of seedless watermelon fruit, and includes a novel method for the production of triploid watermelon fruit.
BACKGROUND OF THE INVENTION
Watermelon is an important horticultural crop that accounts for 2% of the world area devoted to vegetable crops. There were 6,024,000 acres of watermelon grown in the world and 187,000 acres of watermelons grown in the United States in 1997 (FAO Production Yearbook 51, 1998). The estimated annual world watermelon value exceeded $7.6 billion when using the United States average price for 1995–1997. The United States watermelon crop amounted to over 41 million cwt, from over 174,000 harvested acres, and a farm value of over $266 million, accounted for 9.2% of the harvested acres, 10.0% of the production, and 3.5% of the value of the United States fresh vegetable industry in 1999 (USDA Agricultural Statistics 2001). California was the leading state in watermelon farm gate value, exceeded $72 million in 2000, due to high percentage of triploid seedless watermelon grown in California. Seedless watermelon receives well above the average price for seeded watermelons in the market.
The goal of plant breeding is to combine in a single variety or hybrid various desirable traits. Desirable traits may include resistance to diseases and insects, tolerance to heat and drought, reducing the time to crop maturity, greater yield, and better agronomic quality. With mechanical harvesting of many crops, uniformity of plant characteristics such as germination and stand establishment, growth rate, and maturity, are important. Other desired traits may include particular nutrient content, color, fruit shape, as well as taste characteristics.
As with many different plants, watermelon contains a fruit part and a plant part. Each part contains different traits that are desired by consumers and/or growers, including such traits as flavor, texture, disease resistance, and appearance traits such as shape and color. The seedless trait in the watermelon fruit is highly desired by consumers. For production of seedless watermelon, optimum pollination characteristics of the pollinating plant are desired.
Seedless watermelon plants are triploid and must be pollinated by the pollen of diploid watermelon plants. To provide adequate pollinization of seedless watermelon plants, it is current practice to plant diploid pollenizer plants over approximately 25–33% of the field surface. The remaining portion of the field is planted with the triploid plants. Thus, to maximize the value of the crop in the field, growers use high yield marketable diploid watermelon varieties, which ultimately compete with the triploid seedless varieties for sun, nutrients, and space.
A pollenizer for seedless watermelon producing small and unmarketable fruits, which are not harvested, has been disclosed (WO00/70933). However, when this pollenizer is used, a lower total yield of marketable fruit is observed when compared to a commercial pollenizer line. Also, the fruits of the pollenizer described in WO00/70933 that are not harvested become hosts for diseases in the future, and their seeds will germinate and grow into weeds, thus reducing future yields.
The present invention recognizes the need to increase the yield of the seedless watermelon, preferably without loss in total yields of marketable fruits. The present invention also recognizes that novel phenotypic characteristics of the diploid pollenizer plants are needed to permit these diploids to be planted in close proximity to the triploid plants and to share the field surface with the triploid plants, thereby effectively decreasing the surface area of the field required for the diploid pollenizers of the invention. The present invention also recognizes the need to minimize the carryover of unharvested pollenizer fruits as weeds into the subsequent season. The present invention also recognizes the need to increase the pollenizing capacity of diploid watermelon plants in order to further decrease the ratio of diploid to triploid plants in the field, thereby also increasing the yield of the seedless watermelon. The present invention also further recognizes the needs to allow farmers to distinguish the seedless fruits from the fruits of the pollenizer in the field and to provide marketable value to the pollenizer fruits themselves.
SUMMARY OF THE INVENTION
The present invention uses a novel diploid watermelon to improve current methods of commercial production of seedless watermelon and to increase seedless watermelon yield. According to the invention, there is provided a novel enhanced, pollenizer diploid watermelon (hereinafter referred to as “enhanced pollenizer”) and method for pollinating seedless watermelon plants. The present invention includes an enhanced pollenizer comprising, at maturity, small leaves and bearing brittle fruits. The small leaves allow the enhanced pollenizer to be grown in close proximity to the triploid watermelon plants without competing with them, thereby increasing yields of seedless fruits. The brittleness of the fruit offers the advantage that unharvested fruits of the pollenizer can be easily destroyed through conventional field preparation for minimizing carry over as weeds in future plantings.
The enhanced pollenizer of the present invention preferably further comprises heavily branching lacy vines (also referred to as heavily branched open vines) and therefore preferably comprises a high number of open (lacy) branches. The leaves of the enhanced pollenizer also preferably comprise non-overlapping, deep lobes. The openness of the branched or lacy vine results, in part, from the distinct small and non-overlapping, deep lobed leaves. The lacy branches and the small leaves, preferably with non-overlapping, deep lobes, of the invention have the additional advantage to provide more access of bees to the flowers of both the pollenizing and the triploid plant, thereby enhancing transfer of the pollen from enhanced pollenizer watermelon to the female flowers of the triploid watermelon. Easier access by bees to the male flowers of the enhanced pollenizer and coupled with a greater frequency of male flowers provides a greater pollen source for triploid fruit production.
A second advantage of small leaves, preferably characterized by deep, non-overlapping lobes, is that more sunlight is able to penetrate to adjacent triploid plants. A third advantage of small leaves, preferably characterized by deep, non-overlapping lobes, is that these leaves take up less field area than the substantially larger leaves of the diploid pollenizers currently used in the production of seedless watermelon. Thus, as it is less competitive for light, water and fertilizers, the enhanced pollenizer of the present invention can also be grown closer to the triploid plants, and it does not need dedicated space to grow. When the enhanced pollenizer and method of the present invention are used, the triploid seedless watermelon are preferably grown in solid rows at a standard spacing, the enhanced pollinizer being then inter-planted between the plants within the rows. This results in significantly higher numbers of triploid plants per acre compared to the number of triploid watermelon plants that has traditionally been planted, and higher yields of seedless fruits.
Preferably, the fruit of the enhanced pollenizer of the present invention are small and therefore easier to distinguish from the seedless fruits in the field. Therefore, also according to the present invention, there is provided a novel enhanced pollenizer comprising small fruits with brittle rind. The small fruits with brittle rind also reduce the load to the plant and allow the plant to continue flowering for extended periods of time, significantly greater than pollenizer watermelons that are currently used in the production of seedless watermelon. The longer flowering duration of the enhanced pollenizer, compared to traditional pollenizer diploid watermelons, results in increased fruit set and yield of seedless watermelon. The brittle rind also offers the advantage that unharvested fruits of the pollenizer quickly decompose in the fields, and can be easily eliminated from further re-production through conventional crop disposal (discing and plowing).
An additional advantage of the enhanced pollinizer of the present invention is also that its fruits contain very large amounts of seeds, which can be harvested and sold as edible watermelon seeds for food or feed uses, or for use in medicines. This provides additional value to the grower who can harvest and market the fruits of the enhanced pollenizer as such or its seeds.
The present invention also includes an enhanced pollenizer fruit that weighs approximately in the range of about 2 to 7 lbs, preferably about 2 to about 6 lbs, about 2 to about 5 lbs. The average weight for the fruits of the enhanced pollenizer is preferably about 3.2 lbs.
The present invention further includes an enhanced pollenizer fruit rind that is brittle, breaking under a pressure preferably approximately in the range of about 7 to about 11 lbs/in 2 In another preferred embodiment, an enhanced pollenizer fruit rind breaks under a pressure approximately in the range of about 90 to about 150 g/mm 2 , preferably about 100 to about 148 g/mm 2 , preferably about 110 to about 145 g/mm 2 , preferably about 120 to about 140 g/mm 2 .
The present invention includes an enhanced pollenizer having leaves with a surface area approximately in the range of about 20 to about 70 cm 2 , preferably about 22.5 to about 50 cm 2 , preferably about 25 to about 40 cm 2 . In another preferred embodiment, the average leaf surface area of the leaves of the enhanced pollenizer is approximately about 25 to about 40 cm 2 , preferably about 27.5 to about 37.5 cm 2 , preferably about 30 to about 35 cm 2 .
Also included in the invention is a enhanced pollenizer plant for pollinating triploid plants producing seedless watermelon fruit, comprising, at maturity, the characteristics of smaller leaf size compared to the watermelon variety Sangria™, wherein the fruit rind is more brittle than the rind of the variety Sangria™ (a commercial variety of Syngenta Seeds, Inc.). The enhanced pollenizer preferably further comprises small fruits. The leaves of the enhanced pollenizer preferably comprises deep, non-overlapping lobes.
The pollenizer diploid watermelon of the invention is further enhanced by including resistance to various pests and herbicides via conventional plant breeding methods or genetic transformation.
The present invention also provides a method for inter-planting enhanced pollenizer plants amongst the triploid watermelon plants in a field in a pattern that decreases the ratio of pollenizing plants to triploid plants and increases the field surface for triploid plants. This allows for a higher population of triploid plants, than conventional practices, and results in 25–33% higher yield of seedless fruits.
Also included in the present invention is a method of increasing the yield of triploid, seedless watermelon comprising the steps of reducing fruit load of said enhanced pollenizer watermelon, increasing the flowering duration of said pollenizer watermelon, planting said enhanced pollenizer watermelon in a field of triploid watermelon; and harvesting said triploid watermelon.
The invention also provides a method of increasing the yield of triploid seedless watermelon plants by using enhanced pollenizer watermelon plants, preferably with small fruits, wherein the fruit as such are not harvested for human consumption. Preferably, the seeds of the fruits of the enhanced pollenizer are used as food or feed, or in medicines.
The present invention also provides a method for producing an enhanced pollenizer comprising crossing a first watermelon plant having small leaves with a second watermelon plant producing fruit with brittle rind that splits easily and selecting for a watermelon plant having the characteristics of the enhanced pollenizer disclosed herein. Preferably, the first watermelon plant further comprises the characteristic of a heavily branching lacy vine. Preferably, the leaves of the enhanced pollenizer preferably comprises deep, non-overlapping lobes. Preferably, the first watermelon plant has the characteristics of OW824 disclosed herein. Preferably, the second watermelon plant bears small fruit. Preferably, the second watermelon plant has the characteristics of OW823 disclosed herein. In a preferred embodiment, the first watermelon plant is OW824. In a preferred embodiment, the second watermelon plant is OW823. In another preferred embodiment, the first watermelon plant is OW824 and the second watermelon plant is OW823. The method preferably further comprises fixing the traits of the enhanced pollenizer.
The present invention also discloses a watermelon enhanced pollenizer obtainable by a method comprising the steps of a) crossing a watermelon plant with a plant of NO1F3203B deposited under Accession No. PTA-4856, b) obtaining a progeny, c) selecting said progeny for the characteristics of the enhanced pollenizer, preferably small leaves and brittle fruit, In a preferred embodiment, it is further selected for heavily branching lacy vines, preferably for small fruit. In a preferred embodiment, the method further comprises crossing said progeny either with itself or with a plant of NO1F3203B, or with another enhanced pollenizer, and selecting for the said characteristics of the enhanced pollenizer. The method preferably further comprises fixing the traits of the enhanced pollenizer.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a photographic depiction of a leaf of the enhanced pollenizer plant of the invention.
FIG. 2 is a photographic depiction of a leaf of the pollenizer referred to as Sangria™ that is currently used in commerce.
DETAILED DESCRIPTION OF THE INVENTION
Development of Seedless Watermelons
Triploid watermelons are created by crossing a tetraploid (4X) female parent line with diploid (2X) male parent line. The resulting triploid (3X) watermelon seeds are planted in a field with diploid watermelon pollenizers. The resulting fruit of the triploid watermelon are seedless.
To create a tetraploid female watermelon line, it is known in the art to use chemicals that alter mitosis of a diploid inbred line so that unusual numbers of chromosomes are obtained. For example, colchicine is a chemical that alters the mitotic spindle fibers of diploid cells resulting in a number of cells that are tetraploid. The diploid line used to create a tetraploid is selected based on the traits desired for the tetraploid line. Traits that are desired for a tetraploid line may therefore first be introgressed into the diploid inbred lines that will be used to develop the tetraploid lines by breeding methods well known to those skilled in the art. Thus, the diploid and tetraploid parent lines are bred separately for the desired traits.
It usually requires at least two generations of self-pollination and selection to “fix” the 4X condition, after the colchicine treatment generation because, often, chromosomal aberrations are encountered that affect seed fertility, and must be eliminated. Once the stable tetraploid containing the desired characteristics is verified, it then can be used as a stable female parent for the production of the triploid hybrid. A stable diploid inbred is selected for use as the male parent. Methods for developing tetraploid plants are described in Kihara, H., 1951, Triploid Watermelons, Proceedings of American Society for Horticultural Science 58:217–230; and Eigsti, O. J., 1971, Seedless Triploids, HortScience 6, pgs. 1–2.
The tetraploid female parent line and diploid male parent line are planted in a seed production field. The pollen of the diploid male parent is transferred to the female tetraploid flower by methods well known to those skilled in the art. The triploid seed that is produced is present in the resulting fruit and is planted to produce the triploid plants. The breeding of watermelon is further described in Mark Bassett (Editor), 1986, Breeding Vegetable Crops, AVI Publishing, ISBN 0-87055-499-9.
A triploid seedless watermelon is a true F1 hybrid between a tetraploid watermelon, as the female parent, and a diploid watermelon, as the male parent (Kihara, H. 1951. Triploid Watermelons. Proceedings of American Society for Horticultural Science 58:217–230). The seedless condition in triploid watermelon is the result of the presence of three homologous sets of chromosomes per somatic cell rather than the usual two. Cells with three sets of homologous chromosomes are said to be triploid and are designated as 3X. The triploid seedless watermelons have 33 chromosomes (2N=3X=33) in their somatic cells. The inability of the triploid zygote to produce normal viable gametes (pollen and egg cells) causes the absence of seeds in triploid fruits. Typically, seedless watermelons contain small edible white ovules, similar to those in immature cucumbers.
Adequate viable pollen supply from the diploid pollenizer watermelon is essential for the triploid female flowers to set and develop into regular seedless fruit. The female flowers of triploid watermelon will not set if they are not pollinated by viable pollen of diploid watermelon. (Maynard, D. N. (editor), 2001, Watermelons: Characteristics, Production and Marketing , ASHS Press, ISBN 0-9707546-1-2). The diploid watermelon grown in a field of triploid plants is referred to herein as the “pollenizer.” In current commercial triploid watermelon production fields, the triploid watermelon and diploid pollenizer are inter-planted, either within row or between rows, in a ratio of approximately 1 diploid to 2 or 3 triploids. Although research has indicated a 1:4 ratio is acceptable, it is rarely used in commercial plots. (NeSmith, D. S., Duval, J. R. Fruit Set of Triploid Watermelons as a Function of Distance from a Diploid Pollenizer , HortScience 36(1): 60–61, 2001)
Development of Enhanced Pollenizer Diploid Watermelon
According to the present invention, a watermelon (OW824) is selected having the characteristics of a heavily branching lacy vine, early and prolific male flowers, and small leaves with deep, non-overlapping leaf lobes. In this example, the fruit of OW824 is relatively large, the rind and flesh are very firm, the seed size is very big and the flesh is white. OW824 is a publicly available edible seed watermelon variety generally referred to as XinJiang edible seed watermelon.
Also according to the invention, a hybrid watermelon (OW823) is selected for its small fruit (2–3 kg) with brittle rind that splits easily. OW823 also includes the characteristics of mid-sized seeds with yellow flesh and has relatively large leaves. OW823 is a commercially available variety, Tiny Orchid, from Known-You Seeds, Ltd. of Taiwan.
Crossing OW824×OW823 generated progeny having the characteristics of the enhanced pollenizer diploid watermelon of the present invention as described in more detail below.
The initial cross of OW824×OW823 was made during the summer of 2000 in California. The F 1 generation was grown in the greenhouse in the fall of 2000. The F 2 population was grown Florida in the spring, and in California in the summer of 2001. Individuals with the set of traits required for the enhanced pollenizer were successfully identified and self-pollinated in F 2 populations grown in both locations. A total 7 selections were made. The 7 F 3 lines were grown in the field in Florida and the greenhouse in California in the fall of 2001 for further selection and evaluation. Three F 3 lines were identified to best meet our breeding goals and advanced to F 4 generation. They all have the set of the traits required by the enhanced pollenizer. One line, NO1F3203B, now called SP1, is fixed for every trait concerned. NO1F3203B contains the traits that are illustrative of the traits of the enhanced pollenizer of the invention. Other enhanced pollenizer lines with similar characteristics were for example SP2 with slightly larger leaves than SP1, and SP3 with slightly larger fruits than SP1 and a different fruit skin color.
Leaf: The leaves of the enhanced pollenizer are significantly smaller and are more numerous than that of the commonly used pollenizers such as the variety Sangria™ (See FIGS. 1 and 2 ). The leaves of the enhanced pollenizer preferably have a surface area approximately in the range of about 20 to about 70 cm 2 , preferably about 22.5 to about 50 cm 2 , preferably about 25 to about 40 cm 2 . In another preferred embodiment, the average leaf surface area of the leaves of the enhanced pollenizer is approximately about 25 to about 40 cm 2 , preferably about 27.5 to about 37.5 cm 2 , preferably about 30 to about 35 cm 2 . The leaves of the enhanced pollenizer preferably have deep, non-overlapping leaf lobes.
The leaf surface areas of the enhanced pollenizer NO1F3203B and the Sangria™, a pollenizer favored by growers, are shown for comparison purposes in Table 1. The leaves for both NO1F3203B and Sangria™ were taken from mature plants sowed on Aug. 20, 2001 and harvested on Nov. 8, 2001.
TABLE 1
NO1F3203B
LEAF
cm 2
SANGRIA LEAF
cm 2
A
38.75
A
232.00
B
26.25
B
447.25
C
39.75
C
241.50
D
28.75
D
238.00
E
38.25
E
211.00
F
26.27
273.95 (±97.60)
33.08 (±6.46)
The surface area of the enhanced pollenizer leaf of the invention is approximately 5 to 12 times less than the surface area of the typical diploid pollenizer, Sangria™ plant.
FIG. 1 illustrates the non-overlapping characteristic of the deep, non-overlapping lobed leaves of the enhanced pollenizer. Clearly, due to various environmental and physical forces, some of the leaves in this population may have some overlapping lobes, but overlapping lobes are not characteristic thereof. In contrast, the Sangria™ leaf shown in FIG. 2 is characterized as having leaf lobes that habitually overlap each other. The small, deeply lobed and non-overlapping leaves of the invention allow more sunlight through to adjacent triploid watermelon plants.
Branching: The enhanced pollenizer of the invention is preferably also heavily branched (also referred to as “lacy vined” or “open vines”), having significantly more branches (average of 25.9) than the variety referred to as Sangria™, (average of 13). The lacy vine characteristic enables the enhanced pollenizer to produce more accessible male flowers than current diploid pollenizers, thereby enhancing exposure of the flowers to bees. The open or lacy vines also permit the interplanting of the enhanced pollenizer between triploid plants thereby allowing for higher triploid populations and greater seedless fruit production.
Fruit: The fruit rind of the enhanced pollenizer is very brittle and is easily broken. The brittle fruit rind splits easily, due to natural maturation or by breaking or splitting of the fruit during harvest of the seedless triploid watermelon (for example from foot traffic). Splitting of fruit signals the plant that it hasn't completed its reproductive process inducing the plant to continue flowering for a longer period of time. Brittleness is conferred by a gene e (explosive rind, thin, and tender rind, bursting when cut (Rhodes & Dane, 1999 , Gene List for Watermelon , Cucurbit Genetics Cooperative Report 22:71–77). When measured by a penetrometer, the NO1F3203B breaks at about 7–11 lbs/in 2 , whereas a typical watermelon such as Sangria™ breaks at about 21–27 lbs/in 2 . Using a Tester FT02 of Wagner Instruments, Greenwich, Conn. 06836, the fruit of the enhanced pollenizer preferably breaks under a pressure approximately in the range of about 90 to about 150 g/mm 2 , preferably about 100 to about 148 g/mm 2 , preferably about 110 to about 145 g/mm 2 , preferably about 120 to about 140 g/mm 2 . By comparison, the fruit of Sangria™ breaks under a pressure of approximately about 300 g/mm 2 .
Preferably, the fruit size of the enhanced pollenizer is approximately in the range of about 5 to about 7 inches long×about 6 to about 8 inches wide. Preferably, the fruit size of the enhanced pollenizer is approximately about 6 inches long×about 7 inches wide, whereas the typical pollenizer is about 10 inches long×20 inches wide. Small fruit size, as well its brittleness was selected to decrease the load on the plant, thereby extending the duration of plant growth and flower production. Another advantage of the small fruit size is that it enables the harvester to easily distinguish the seedless fruit from seeded fruit, is often difficult with currently used pollenizers, which are selected based on their overall similarity to the seedless triploid plants. The fruit of the enhanced pollenizer weighs approximately in the range of about 2 to about 7 lbs, preferably about 2 to about 6 lbs, preferably about 2 to about 5 lbs. The average weight for the fruits of the enhanced pollenizer is preferably about 3.2 lbs.
The rind color of the enhanced pollenizer is preferably light green with very thin dark green lines. The fruit of the enhanced pollenizer of the invention can be distinguished from the fruit of most (about 99%) of the commercially available seedless watermelon varieties.
Flowering: The plants of the enhanced pollenizer, e.g. of NO1F3203B, also flower approximately 7 to 10 days earlier than diploid pollenizer plants currently used for the production of seedless watermelon, and continue flowering during fruit harvest time of the seedless watermelon, 2 to 3 weeks longer than standard diploid pollenizer plants. Thus, the pollenizer plant of the invention has a flowering duration that is approximately 3 to 5 weeks longer than pollenizers currently used.
Other Traits: The enhanced pollenizer, e.g. NO1F3203B, can be used either as donor of the set of traits disclosed above, or as the recurrent parent to develop additional enhanced pollenizer lines. In accordance with the invention, the enhanced pollenizer watermelon contains traits of disease resistance (e.g. Fusarium wilt, Anthracnose, Gummy Stem Blight, Powdery Mildew, and Bacterial Fruit Blotch), insect resistance (e.g. cucumber beetle, aphids, white flies and mites), salt tolerance, cold tolerance and/or herbicide resistance added. These traits can be added to existing lines by using either conventional backcrossing method, pedigree breeding method or genetic transformation. The methods of conventional watermelon breeding are taught in several reference books, e.g. Maynard, D. N. (editor), 2001, WATERMELONS Characteristics, Production and Marketing, ASHS Press; Mohr, H. C., Watermelon Breeding, in Mark J. Bassett (editor), 1986, Breeding Vegetable Crops, AVI Publishing Company, Inc. General methods of genetic transformation can be learned from publish references, e.g. Glich et al., (Eds), 1993, Methods in Plant Molecular Biology & Biotechnology, CRC Press, and more specifically for watermelon in WO02/14523.
Forms of the Enhanced Diploid Pollenizer: Once the enhanced pollenizer lines are developed, several forms of enhanced pollenizer varieties can be used in commercial seedless watermelon production. Specifically, these forms of enhanced pollenizer varieties include: Forms of Enhanced Pollenizer: (1) Open Pollinated Variety: The stable, enhanced lines of the enhanced pollenizer are grown in isolated fields, at least 2,000 meters from other watermelon varieties. Pollination is conducted in the open fields by bees. Seeds are harvested from the seed production field when the fruit and seeds are fully developed. The seeds are dried and processed according to the regular watermelon seed handling procedures. (2) Synthetic Variety: The seed of different enhanced pollenizer lines are individually produced in isolated fields. Bee pollination is used in each isolation. The seed of different enhanced pollenizer are separately harvested and processed. Mixing several enhanced pollenizer lines in various ratios forms the synthetic varieties. The synthetic variety can provide a broader pollenizer population for the triploid watermelons. (3) Open-Pollinated Hybrid Variety: Two or several enhanced pollenizer lines are planted in the same seed production field with bee pollination. The harvested seed lot, therefore, contains both hybrid and inbred seed. (4) Hybrid Variety: Two enhanced pollenizer lines, the male and female parents, are planted in the same field. Hand pollination is conducted. Only the seed from female parent line is harvested and sold to the commercial grower to use as pollenizer. Table 3 in Example 7 shows the results obtained using various combinations of inbred and hybrid enhanced pollenizers.
Method of Seedless Watermelon Production: Most current commercial seedless watermelon growers in NAFTA use elongated diploid varieties with an Allsweet stripe pattern: light green skin with wide green stripes, as the pollenizer. The variety referred to as Sangria™ is the most preferred Allsweet type pollenizer and is available as a commercial product from Syngenta Seeds, Inc., Boise Id. Typically, the pollenizer is inter-planted with the triploid watermelon either between rows or within row. The current method of planting diploid pollenizers include planting the diploid plants at a distance from adjacent triploid such that they have the same field area available per plant as the field area that is available to the triploid watermelon plants. For example, currently watermelon growers inter-plant the diploids within a row, whereby the space between all adjacent plants within the row are approximately equidistant.
Alternatively, diploid pollenizer plants are planted in separate rows between rows of triploid watermelon plants. All rows of diploid and triploid plants in such a field are planted approximately equidistant from each other. In other words, under current methods for producing seedless watermelon, the width of all diploid and triploid rows is the same.
The method of the present invention includes planting the enhanced pollenizer watermelon plants in rows that are narrower than the triploid rows, thereby saving field area for production of triploid seedless watermelon.
Table 2 below shows different planting alternatives for watermelon pollenizer, including a preferred interplanting according to the present invention (right column).
TABLE 2
seeded
seedless
seedless
seeded
seedless
seedless
seeded
Conventional 2:1 pollenizer ratio using the row method
O
X
X
O
X
X
O
O
X
X
O
X
X
O
O
X
X
O
X
X
O
O
X
X
O
X
X
O
O
X
X
O
X
X
O
O
X
X
O
X
X
O
O
X
X
O
X
X
O
O
X
X
O
X
X
O
Conventional 2:1 pollenizer ratio using the within row method
X
O
X
X
O
X
X
O
X
X
O
X
X
O
X
X
O
X
X
O
X
X
O
X
X
O
X
X
O
X
X
O
X
X
O
X
X
O
X
X
O
X
X
O
X
X
O
X
X
O
X
X
O
X
X
O
Pollenizer inter-planted at a 3:1 pollenizer ratio
X
X
X
X
X
X
X
♦
♦
X
X
X
X
X
X
X
♦
♦
♦
X
X
X
X
X
X
X
♦
♦
X
X
X
X
X
X
X
♦
♦
X
X
X
X
X
X
X
♦
♦
♦
X
X
X
X
X
X
X
♦
♦
X
X
X
X
X
X
X
♦
♦
X
X
X
X
X
X
X
Seeded = O
Seedless = X
Pollenizer = ♦
EXAMPLES
The following Examples are provided to illustrate the present invention, and should not be construed as limiting thereof.
Example 1
Triploid watermelon plants are planted in parallel rows 7 feet apart and 3 feet apart within each row. However, the enhanced diploid watermelon plants are planted in a narrow row 3.5° wide (½ the width of the triploid rows) between every second and third triploid row. For example, rows A and B are two consecutive rows of triploids, each 7-foot wide. Row C is a diploid row that is 3.5 feet wide. Row D and E are the following two 7 foot wide rows of triploids, followed by the 3.5-foot wide row F of diploid plants. This pattern is repeated across the width of the field. Because the diploid row is narrower according to the method of the invention, the distance between rows B and D is 10.5 feet instead of the traditional distance of 14 feet. Using this ratio of 1 pollenizer row for every 2 triploid rows (1:2), 33.3% of the field would normally be used for the pollenizer plants. Reducing the width of the pollenizer row according to the method of the invention by one-half, the gain of space for planting additional triploid plants would be 33.3%/2 or approximately 17%.
Example 2
Triploid watermelon plants are again planted in parallel rows 7 feet apart and 3 feet apart within each row. As in Example 1, the enhanced diploid watermelon plants are planted in a narrow row 3.5° wide, but are planted between every third and fourth triploid row. For example, rows A, B, and C, are three consecutive rows of triploids, each row being 7′ wide. The following row D is a diploid, row that is 3.5 feet wide. Row E, F, and G are the following three rows of triploids, all 7 feet wide, followed by a 3.5 foot wide row of enhanced pollenizer plants. This pattern is repeated across the width of the field. Because the diploid row is narrower according to the method of the invention, the distance between rows B and D is again 10.5 feet instead of the traditional distance of 14 feet. Using this ratio of 1 pollenizer row for every 3 triploid rows (1:3), 25% of the field would normally be used for the pollenizer plants. Reducing the width of the pollenizer row according to the method of the invention by one-half, the gain of space for planting additional triploid plants would be 25%/2 or approximately 12%.
Example 3
Triploid watermelons are planted in parallel rows 8 feet apart and 3 feet apart within each row. The enhanced diploid watermelon plants are planted in a narrow row 4.0 feet wide (½ the width of the triploid rows) between every second and third triploid row. For example, rows A and B are two consecutive rows of triploids, each 8 foot wide. Row C is a diploid row that is 4.0 feet wide. Row D and E are the following two 8 foot wide rows of triploids, followed by the 4.0 foot wide row F of diploid plants. This pattern is repeated across the width of the field. Because the diploid row is narrower according to the method of the invention, the distance between rows B and D is 12.0 feet instead of the traditional distance of 16 feet. Using this ratio of 1 pollenizer row for every 2 triploid rows (1:2), 33.3% of the field would normally be used for the pollenizer plants. Reducing the width of the pollenizer row according to the method of the invention by one-half, the gain of space for planting additional triploid plants would be 33.3%/2 or approximately 17%.
Example 4
Referring to the above three examples, when triploids are planted in rows 8 feet apart, and the ratio of diploid to triploid is 1:3, it is now clear that the reduction of the pollenizer row width by one-half will gain space for planting additional 12%.
Example 5
It is also within the scope of the invention to reduce the pollenizer row width to approximately ⅓ that of the triploid row width. Thus, according to the present invention, at any row width, when the ratio of diploid rows to triploid rows is:
(a.) 1:2, the savings of field area for additional triploid plants is (33%×⅔) or 22%.
(b) 1:3, the savings of field area for additional triploid plants is (25%×⅔) or 16.5%.
(c) 1:4, the savings of field area for additional triploid plants is (20%×⅔) or 13.2%.
It is also within the scope of the invention to reduce the pollenizer row width to approximately ⅔ that of the triploid row width.
Example 6
It is also within the scope of the present invention to inter-plant the diploid plants within the rows of triploid plants. According to the invention, the triploid plants are first planted by machine or by hand in regularly spaced rows. The triploid plants within each row are planted, for example, 3 feet apart. After the triploid plants are in the field as described, the diploid pollenizer watermelon plants of the invention are inter-planted, by hand, within each row approximately midway between the triploid plants. Thus, in this example, the diploid plants are planted approximately 1.5 feet from the flanking triploid plants within the row. Due to the characteristics of the enhanced pollenizer of the invention, the diploid plants can be inter-planted within each row after every 2, 3, 4, 5, 6, 7, 8, 9, or 10 consecutive triploid plants. It is currently preferred in the industry to plant the diploid plants after every 2 (1:2) or 3 (1:3) triploid plants within the row. A 1:4 ratio has been reported, but is not normally used in commercial fields due to inadequate pollenization of the triploid plants. The field area saved under this example, when compared with both the current methods of planting diploids in separate rows or within a row at the ratios (diploid:triploid) of:
(a) 1:2, is 33.3%, (b) 1:3, is 25%, (c) 1:4, is 20%.
The enhanced pollenizer and method of the present invention comprises planting the enhanced pollenizer watermelons in rows that are narrower than the rows containing the triploid plants. Although the narrower diploid row will encourage diploid plant growth into the triploid plant row, the novel characteristics of the enhanced pollenizer watermelon allow it maintain its ability to sufficiently pollinate the triploid plants in the field. Thus, the enhanced pollenizer watermelon and method of the present invention increase the yield of seedless watermelon in a field.
Example 7
A split-plot design is used for this experiment to test three inbred enhanced pollenizers and three hybrid enhanced pollenizers against the commercial checks Sangria 2:1 and Sangria 3:1. All 6 enhanced pollenizers are inserted between regularly spaced (80″×24″) triploid plants in the ratio of 3:1. For Sangria 2:1 ratio, every third space is a Sangria plant. For Sangria 3:1 ratio, every 4 th space is a Sangria plant. A 5:1 ratio is also included in this trial using the mixed enhanced pollenizers. In this treatment, the enhanced pollenizers plant is inserted between 5 th and 6 th regularly spaced triploid plants. So there are total 9 main plots, the 9 main treatments/pollinators, in this experiment. The 9 main plots are separated by cantaloupe plants. 3 different triploids, the sub-plots, with 2 replications are used to test different pollinators (see table 3). Plants are well grown except the leaf-miner damage. This damage results in smaller fruit size for Palomar and Tri-X-313. The trials are evaluated after about two months. The number of triploid fruit in each sub-plot is counted. The first 15 fruits in each sub-plot are non-selectively harvested and weighted. 10 fruits are also harvested from each pollinator and measured for rind firmness. Data are analyzed using S-Plus 6.1. The enhanced pollenizers varieties are also evaluated for fruit size and other fruit characteristics.
As shown in table 3, very similar fruit set per plant is achieved for all the pollenizer used. Smaller triploid seedless melons are produced when Sangria is used as pollinator in the ratio of 2:1 in this experiment. This could be due to Sangria's strong competition to the triploid plant for space, water and nutrient. A lot more seedless melons per acre, 25% (compared to the 3:1 ratio) to 33% (compared to the standard 2:1 ratio), are produced when enhanced pollenizers varieties are used as pollenizer.
The rind of enhanced pollenizer varieties of the present invention is much less durable compared to diploid pollenizer Sangria, as indicated by the force used to penetrate the rind using a fruit firmness tester (Fruit Firmness Tester FT02 of Wagner Instruments, Greenwich, Conn. 06836). Should the pollenizer not be harvested for its commercial value, its brittle rind allows the pollinator fruit to be destroyed during fruit harvest or soon thereafter. This is helpful for unloading the pollenizer plant and maintaining the flowering ability of the pollenizer plants for longer period of time. The brittle rind of the enhanced pollenizer also reduces the risk of carry-over into the next season, as a weed, since the fruit, and plant debris can be easily destroyed, after harvest of the triploid fruit.
Enhanced pollenizer plants flower about 7 days earlier than diploid Sangria. Enhanced pollenizer plants produce more than twice many of branches compared to Sangria. This allows enhanced pollenizer plants to produce more male flowers, thereby reducing the number of pollenizer plants needed. The vine of enhanced pollenizer plant is much thinner than regular diploid plants. The leaf size and leaf-lobe size of enhanced pollenizer are much smaller than those of Sangria. All these make enhanced pollenizer much less competitive for light, water and fertilizer, compared to regular diploid watermelon.
Enhanced pollenizer plants are producing male flowers after the harvest of triploid seedless fruits. This gives the potential of having a second fruit set and multiple harvests of triploid seedless fruit with single planting. The male flowers open earlier in the morning compared to regular watermelons, especially in the cooler days.
TABLE 3
Seedless Watermelon Fruit Yields Produced by Using Different Pollenizer
and Rind Firmness of Different Pollenizer
Rind
Fruit/Plant
Fruit/Acre
Frt Wt (lbs)
Firmness
Pollinator
Palomar
RWT8124
TriX313
Mean
Palomar
RWT8124
TriX313
Mean
Palomar
RWT8124
TriX313
Mean
(g/mm 2 )
SP Hyb 5:1
2.00
3.60
2.15
2.58
6534
11652
6957
8381
13.6
6.0
15.4
11.6
NA
SP1
2.05
3.55
1.95
2.53
6719
11661
6413
8265
12.2
5.7
14.6
10.8
121
SP1 x SP3
2.00
3.60
2.15
2.58
6579
11752
7001
8444
13.2
6.0
14.9
11.3
139
SP2
1.90
3.50
1.90
2.43
6258
11479
6137
7958
12.1
6.0
13.3
10.5
123
SP2 x SP1
1.85
3.30
2.20
2.45
6004
10728
7106
7946
13.1
5.8
14.0
10.9
129
SP3
1.90
3.40
1.55
2.28
6210
11170
5116
7499
12.8
6.0
14.1
11.0
133
SP3 x SP2
1.90
3.60
2.05
2.52
6219
11649
6577
8149
12.5
5.8
13.9
10.7
129
Sangria 2:1
1.90
3.50
2.00
2.47
4086
7596
4375
5352
10.5
5.7
12.5
9.6
Sangria 3:1
1.95
3.35
1.95
2.42
4737
8248
4863
5949
12.4
5.6
12.9
10.3
302
Mean
1.95
3.52
2.02
2.49
5770
10405
5946
7374
12.5
5.8
13.8
10.7
154
Factor
P-value
P-value
P-value
P-value
Pollinator
0.0239
0.0000
0.0000
0.0000
Triploid
0.0000
0.0000
0.0000
Pollinator*Triploid
0.4121
0.0061
0.0029
Replication
0.9372
0.8580
0.6310
Example 8
Eight triploid varieties (see table 4) are transplanted on two 80″ beds and spaced 24″ apart. These two beds are located in the center of our regular hybrid evaluation block. A diploid hybrid bed is placed in each side of the two trial beds to eliminate the pollination factor. About 90 plants are transplanted for each variety. Two days later, each triploid plot is divided into 2 sub-plots and the enhanced pollenizer SP1 plants of the present invention are inserted in one of the 2 sub-plots in the ratio of 3:1, for each of the 8 triploid varieties. This planting pattern allows 3260 triploid plants per acre. The 8 triploid varieties differ in fruit shape, size and maturity. About 10 weeks later, the first 30 fruits are non-selectively harvested from each sub-plot and are weighted using a digital scale. Data are analyzed using S-Plus 6.1.
As shown in table 4, the fruit size differences are solely due to triploid variety differences. Inserting of enhanced pollenizer SP1 between regularly spaced triploid plants in the ratio of 3:1 does not reduce the fruit size of triploid seedless fruit, regardless of the type of triploid variety. The triploid varieties used in this trial represent a very broad spectrum of triploids used in commercial production. They differ in fruit size, fruit shape, and maturity. Thus, inserting enhanced pollenizer plants of the present invention between regularly spaced triploid plants does not reduce the fruit size of the triploid seedless melons. Therefore, a seedless grower can plant his or her fields solid with triploid plants and then insert the enhanced pollenizer plants in a ratio of 3:1 or less. This planting pattern and ratio allows growers to produce significant higher (25 to 33%) yields of seedless fruit per acre.
TABLE 4
Effect of Inserting Super-Pollenizer Between Regularly Spaced
(80″ × 24″) Triploid Plants in the Ratio of 3:1 to
the Fruit Size of Eight Different Triploid Watermelon Varieties
Super-Pollenizer Insertion
Triploid Variety
No
Yes
Mean
3X Sangria
18.05
18.51
18.28
Palomar
14.23
16.21
15.22
RWT 8126
16.97
17.15
17.06
RWT8124
6.26
6.03
6.15
RWT8139
15.46
14.43
14.94
RWT8140
15.31
15.73
15.52
Shadow
15.97
14.73
15.35
Tri-X-313
15.77
15.60
15.69
Mean
14.75
14.80
14.77
Factor
P-Value
Triploid Variety
0.0000
Super-Pollenizer
0.8829
Variety*Super-Pollenizer
0.2451
DEPOSIT
Applicants have made a deposit of at least 2500 seeds of enhanced watermelon pollenizer line NO1F3203B (now called SP1) with the American Type Culture Collection (ATCC), Manassas, Va., 20110-2209 U.S.A., ATCC Deposit No: PTA-4856. This deposit of the enhanced watermelon pollenizer line NO1F3203B/SP1 will be maintained in the ATCC depository, which is a public depository, for a period of 30 years, or 5 years after the most recent request, or for the effective life of the patent, whichever is longer, and will be replaced if it becomes nonviable during that period. Additionally, Applicants have satisfied all the requirements of 37 C.F.R. §§1.801–1.809, including providing an indication of the viability of the sample. Applicants impose no restrictions on the availability of the deposited material from the ATCC; however, Applicants have no authority to waive any restrictions imposed by law on the transfer of biological material or its transportation in commerce. Applicants do not waive any infringement of its rights granted under this patent or under the Plant Variety Protection Act (7 USC 2321 et seq.).
The foregoing invention has been described in detail by way of illustration and example for purposes of clarity and understanding. However, it will be obvious that certain changes and modifications such as single gene modifications and mutations, somaclonal variants, variant individuals selected from large populations of the plants of the instant inbred and the like may be practiced within the scope of the invention, as limited only by the scope of the appended claims. Thus, although the foregoing invention has been described in some detail in this document, it will be obvious that changes and modification may be practiced within the scope of the invention, as limited only by the scope of the appended claims.
All references cited herein are incorporated by reference in the application in their entireties.
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An enhanced, diploid pollenizer watermelon plant and method used to maximize the yield of triploid seedless watermelons per area. The enhanced pollenizer watermelon plant of the invention is either a hybrid variety, an open-pollinated variety or a synthetic variety, that exhibits the characteristics of small leaves and fruit with a brittle rind that splits when the fruit is overripe or breaks when relatively small physical forces are applied. The watermelon plant of the invention is also preferably characterized by extended flowering duration, thereby increasing the number of triploid watermelon flowers that are pollinated and set fruit. The method for producing a seedless watermelon fruit, includes the steps of providing a pollenizer diploid watermelon plant, extending the duration of flowering of the pollenizer plant while reducing the number of such plants needed to pollenize the same number of triploid watermelon plants, and maximizing dispersal of the pollenizer watermelon plant throughout the field of triploid watermelon plants.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a fire isolation device for free standing structures. More particularly, the present invention relates to a fire resistant house cover.
2. Description of the Prior Art
Every year free standing structures are either destroyed or endangered by out of control forest fires. These forest fires bum out of control usually because they are just too large for fire fighting personnel to contain. Out of control forest fires can easily destroy any free standing fire prone structure in their path. Therefore, there is a need for a fire protection device that can isolate free standing fire prone structures such as single family homes from out of control forest fires.
Numerous innovations for fire isolation devices have been provided in the prior art that are described as follows. Even though these innovations may be suitable for the specific individual purposes to which they address, they differ from the present invention as hereinafter contrasted.
U.S. Pat. No. 3,828,856 to Wallis discloses a fire blanket pack consisting of a fire resistant blanket inside a closed container. This patent differs from the present invention because it does not disclose any mechanism employing fire resistant materials for isolating free standing structures.
U.S. Pat. No. 5,051,290 to Stober et al. discloses a fire barrier blanket for isolating a fire within a spliced portion of an electrical cable or conduit. This patent differs from the present invention because it does not disclose any mechanism employing fire resistant materials for isolating free standing structures from external fires.
U.S. Pat. No. 5,091,243 to Tolbert et at. discloses a fire resistant fabric suitable for use as a flame barrier. This patent differs from the present invention because it does not disclose any mechanism employing fire resistant materials for isolating free standing structures.
U.S. Pat. No. 5,188,186 to Nash discloses a fire resistant barrier for isolating a fire within a confined area such as a mine shaft. This patent differs from the present invention because it does not disclose any mechanism employing fire resistant materials for isolating free standing structures from external fires.
Numerous innovations for fire isolation devices have been provided in the prior art that are adapted to be used. Even though these innovations may be suitable for the specific individual purposes to which they address, they would not be suitable for the purposes of the present invention as heretofore described.
SUMMARY OF THE INVENTION
In accordance with the present invention, a fire resistant house cover includes a fire resistant tarp, a support structure and a moving mechanism. The fire resistant tarp is of a dimension to fully enclose a free standing house. The support structure supports the fire resistant tarp when the tarp is in an upward position enclosing the free standing house and collapses when the tarp is in a downward position exposing the free standing house. The moving mechanism is capable of moving the tarp and support structure from the downward position to the upward position.
Broadly considered, the invention comprises a fire resistant cover that can be moved into a position to completely isolate a free standing structure from an external fire. This fire resistant cover can be readily moved into position by a user from either a local or remote site. The fire resistant cover may be manufactured in standard sizes that can be readily customized to fit varying size structures. When installed, this invention can prevent damage to a free standing structure and its contents from an external fire.
Accordingly, it is an object of the present invention to provide a device employing fire resistant materials for isolating free standing structures from external fire sources.
More particularly, it is an object of the present invention to provide a fire resistant house cover for isolating homes from uncontrolled forest fires.
In keeping with these objectives, and with others which will become apparent hereinafter, one feature of the present invention resides, briefly stated, in that the fire resistant house cover can completely enclose a free standing home with fire resistant material.
When the fire resistant house cover is designed in accordance with the present invention, it will provide reasonable protection for free standing homes from out of control forest fires.
In accordance with another feature of the present invention, the fire resistant house cover can be activated by a local manual switch, a local heat sensing switch, remote radio transmitter, telephone or tied into a fire alarm.
Another feature of the present invention is that it is capable of moving to its upward position completely enclosing the home in a period of thirty minutes or less.
Yet another feature of the present invention is that it comes in standard sizes that can be easily customized to fit a variety of different size homes.
Still another feature of the present invention is that it has a continuous encasement around the perimeter of the house for storing the fire resistant tarp and the support structure when the fire resistant house cover is in its downward position, thereby preserving the aesthetic appearance of the house and protecting the fire resistant tarp and the support structure from environmental conditions.
Yet still another feature of the present invention is that the fire resistant tarp is fabricated from synthetic fire resistant material such as NOMEX (TM).
Still yet another feature of the present invention is that the support structure is fabricated from fire resistant materials such as metal, metal alloys, fiberglass, graphite or carbon reinforced composites.
Another feature of the present invention is that the moving mechanism consists of winches, cables and cable guides.
Another feature of the present invention is that clips attach the moving mechanism cables to the sides of the house to prevent injury and give an overall aesthetic appearance.
An object of the present invention is to provide protection to free standing homes from uncontrolled external fires.
A further object of the present invention is to reduce the risk of or minimize the damage to homes and its contents from uncontrolled forest fires, thereby reducing fire insurance premiums.
A further object of the present invention is to provide the fire resistant house cover at a relatively low cost.
The novel features which are considered characteristic for the invention are set forth in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of the specific embodiments when read and understood in connection with the accompanying drawing(s).
BRIEF LIST OF REFERENCE NUMERALS UTILIZED IN THE DRAWING
10--fire resistant house cover 10
12--ground surface 12
14--house 14
16--storage encasement 16
18--storage encasement cover 18
19--storage encasement anchor ring 19
20A--left tarp 20A
20B--right tarp 20B
21--tarp anchor cord 21
22A--left front tarp cable 22A
22B--right front tarp cable 22B
22C--left rear tarp cable 22C
22D--right rear tarp cable 22D
24--tarp cable guide 24
26A--front winch 26A
26B--rear winch 26B
28--front pivotal anchor 28
30A--left front support member 30A
30B--right front support member 30B
32--pivoting hinge 32
34--tarp cable clip 34
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a top perspective view of the preferred embodiment of the fire resistant house cover having the left tarp and right tarp in the downward position exposing the house;
FIG. 2 is a front perspective view of the preferred embodiment of the fire resistant house cover having the left tarp and right tarp in the downward position exposing the house;
FIG. 3 is a front perspective view of the preferred embodiment of the fire resistant house cover having the left tarp and right tarp in the halfway between the upward and downward position partially enclosing the house;
FIG. 3A is a cross sectional view of the storage encasement along the 3A axis of FIG. 3 showing the right tarp anchored within the storage encasement;
FIG. 3B is a cross sectional view of the storage encasement along the 3B axis of FIG. 3 showing the left front support member and the right front support member pivotally anchored within the storage encasement; and
FIG. 4 is a front perspective view of the preferred embodiment of the fire resistant house cover having the left tarp and right tarp in the upward position enclosing the house.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a top perspective view of the preferred embodiment of the fire resistant house cover 10 having the left tarp (not shown) and right tarp (not shown) in the downward position exposing the house 14 exhibiting the following features: ground surface 12; house 14; storage encasement 16; storage encasement cover 18; left front tarp cable 22A; right front tarp cable 22B; left rear tarp cable 22C; right rear tarp cable 22D; tarp cable guide 24; front winch 26A; and rear winch 26B.
The storage encasement 16 is a continuous trench in the ground surface 12 around the perimeter of the house 14. The storage encasement preferably should be lined with a rigid noncorrosive material such as a plastic or plastic composite. The storage encasement 16 contains the left tarp (not shown), right tarp (not shown), left front support member (not shown) and right front support member (not shown) when they are in the downward position. Keeping the left tarp (not shown), right tarp (not shown), left front support member (not shown) and right front support member (not shown) in the storage encasement 16 helps preserve the aesthetic appearance of the house 14 and also shields these parts from environmental conditions. Located on the top of the storage encasement 16 is the storage encasement cover 18, which is pivotally mounted to the inner surface of the storage encasement 16. The storage encasement cover 18 is a safety feature that prevents anyone from inadvertently tripping over or falling into the storage encasement 16, thereby injuring themselves.
The lower portions of the left front tarp cable 22A, right front tarp cable 22B, left rear tarp cable 22C and right rear tarp cable 22D extend into the storage encasement 16 as shown. These cables inside the storage encasement 16 are attached to the left tarp (not shown) and right tarp (not shown) respectively. The left front tarp cable 22A, right front tarp cable 22B, left rear tarp cable 22C and right rear tarp cable 22D provide part of the means to pull the left tarp (not shown) and right tarp (not shown) into the upward position enclosing the house 14.
Located at each of the four comers on the roof of the house 14 is a tarp cable guide 24. The tarp cable guide 24 guides each of the tarp cables. The top ends of both the left front tarp cable 22A and the right front tarp cable 22B are attached to the front winch 26A. Similarly, the top ends of both the left rear tarp cable 22C and the right rear tarp cable 22D are attached to the rear winch 26B. The front winch 26A and the rear winch 26B are mounted on the front and rear portions of the roof of the house 14 respectively. The front winch 26A and the rear winch 26B provides the mechanical force to pull the left tarp (not shown) and right tarp (not shown) into the upward position.
During operation the front winch 26A and the rear winch 26B must be activated in order to move the left tarp (not shown) and right tarp (not shown) into the upward position. The activation means can be by a local manual switch, local heat sensing switch, remote radio transmitter, telephone or tied into a fire alarm.
FIG. 2 is a top perspective view of the preferred embodiment of the fire resistant house cover 10 having the left tarp 20A and right tarp 20B in the downward position exposing the house 14 exhibiting the following features: ground surface 12; house 14; storage encasement 16; storage encasement cover 18; left tarp 20A; right tarp 20B; left front tarp cable 22A; right front tarp cable 22B; left rear tarp cable 22C; right rear tarp cable 22D; tarp cable guides 24; front winch 26A; rear winch 26B; tarp cable clips 34; left front support member 30A; and right front support member 30B.
Two tarp cable clips 34 are shown located on the front--bottom portion of both the left and right wall of the house 14. There are also two more tarp cable clips 34 (not shown) on the rear--bottom portion of both the left and right wall of the house 14. When the left tarp 30A and right tarp 30B is in the downward position, the left front tarp cable 22A, right front tarp cable 22B, left rear tarp cable 22C and right rear tarp cable 22D snap into the adjacent tarp cable clip 34, thereby holding the four tarp cables flush to the walls of the house 14 as shown. This serves as a safety feature preventing a person from walking into or tripping over one of the tarp cables, thereby injuring themselves.
The left tarp 20A, right tarp 20B left front support member 30A and right front support member 30B are contained within the storage encasement 16 when they are in the downward position.
FIG. 3 is a front perspective view of the preferred embodiment of the fire resistant house cover 10 having the left tarp 20A and right tarp 20B halfway between the upward and downward position partially enclosing the house 14 exhibiting the following features: fire resistant house cover 10; ground surface 12; house 14; storage encasement 16; storage encasement cover 18; left tarp 20A; right tarp 20B; left front tarp cable 22A; right front tarp cable 22B; left rear tarp cable 22C; right rear tarp cable 22D; front winch 26A; rear winch 26B; left front support member 30A; right front support member 30B; and pivoting hinges 32.
The left tarp 20A and right tarp 20B are shown being drawn up the walls of the house 14. Both the left tarp 20A and right tarp 20B have a front surface, top surface and back surface (not shown), and must be fabricated from a fire resistant material such as carbon-graphite, asbestos, metal, metal alloys, ceramic or plastic composites. The left tarp 20A and right tarp 20B must be of a dimension to completely enclose the house when they are in the upward position. The entire bottom edge of both the left tarp 20A and right tarp 20B are anchored within the storage encasement 16. This is accomplished by tarp anchor cords 21 attached to the lower edges of the left tarp 20A and right tarp 20B that are tied to anchor rings 19 located on the outer wall of the storage encasement 16. An example of a tarp anchor cord 21 and anchor ring 19 is shown in FIG. 3A. The tarp anchor cord 21 and anchor ring 19 pairs prevent the bottom portions of the left tarp 20A and right tarp 20B from being pulled upward, thereby exposing the bottom portion of the house 14. The edges of the top surfaces of both the left tarp 20A and right tarp 20B are each attached to their respective tarp cables 22A, 22B, 22C, 22D which allows the winches to pull the left tarp 20A and right tarp 20B into the upward position.
The left front support member 30A, right front support member 30B, left rear support member (not shown) and right rear support member (not shown) make up the support structure that rigidly supports both the left tarp 20A and right tarp 20B in the upward position. These support members should be fabricated from fire resistant materials such as, fiberglass, graphite or carbide reinforced composites.
The left front support member 30A and the right front support member 30B each consists of a lower portion, middle portion and an upper portion that are attached by two pivoting hinge 32. By the bottom pivoting hinge 32 pivoting inward and the top pivoting hinge 32 pivoting outward the pivoting hinges 32 allow the left front support member 30A and the right front support member 30B to fold in half from an extended position allowing them to fit into the storage encasement 16 when the left harp 20A and right harp 20B are in the downward position. The length of the bottom portions of left front support member 30A and the right front support member 30B cannot be longer than what can fit in the storage encasement 16. The middle and upper portion lengths are determined by the height of the house 14, but can be no longer than the bottom portions length. Also, the middle and upper portion lengths must be equal to ensure that the top end of the support members are adjacent to the top surfaces of the left tarp 20A and right harp 20B when in the storage encasement 16.
The top end of the left front support member 30A is attached to the front edge of the top surface of the left harp 20A and is contained within the front surface of the left tarp 20A. Similarly, the top end of the right front support member 30B is attached to the front edge of the top surface of the right tarp 20B and is contained within the front surface of the right harp 20B. Both bottom ends of the left front support member 30A and the right front support member 30B are attached to the front pivotal anchor 28 as shown in FIG. 3B. The front pivotal anchor 28 allows the left front support member 30A and the right front support member 30B to be rotated from a horizontal position when inside the storage encasement 16 to a vertical position when fully extended. The front pivotal anchor 28 is rigidly attached to the bottom surface of the storage encasement 16.
The left rear support member (not shown), right rear support member (not shown) and rear pivotal anchor (not shown) are assembled similarly and serve the same function as the previously described left front support member 30A and right front support member 30B.
FIG. 4 is a front perspective view of the preferred embodiment of the fire resistant house cover 10 having the left tarp 20A and right tarp 20B in the upward position enclosing the house 14 exhibiting the following features: ground surface 12; house 14; storage encasement 16; storage encasement cover 18; left tarp 20A; right tarp 20B; front winch 26A; rear winch 26B; left front support member 30A; right front support member 30B; and pivoting hinges 32.
The fire resistant house cover 10 is shown in the upward position completely enclosing the house. The left front support member 30A and the right front support member 30B are fully extended giving rigid support to the left tarp 20A and right tarp 20B. Due to the fire resistant nature of the left tarp 20A and right tarp 20B, the house can be isolated protecting it from fire damage.
During operation, the fire resistant house cover 10 starts in the downward position with the left tarp 20A, right tarp 20B, left front support member 30A and right front support member 30B contained in the storage encasement 16 as shown in FIG. 1. Also, in the downward position the tarp cables are snapped into their respective tarp cable clip 34 as shown in FIG. 2. The front winch 26A and rear winch 26B are then activated applying a force to the left front tarp cable 22A, right front tarp cable 22B, left rear tarp cable 22C and right rear tarp cable 22D. This force causes the tarp cables to snap out of their respective tarp cable clip 34 and be drawn toward the front winch 26A and rear winch 26B. This in turn causes the bottom ends of the tarp cables to exert a force on the top edges of the left tarp 20A and right tarp 20B. The top edges of the left tarp 20A and right tarp 20B will then simultaneously be drawn out of the storage encasement 16 and exert an upward force on the encasement storage cover 18 rotating it up and inward.
The left tarp 20A and right tarp 20B will further be drawn upward along the four sides of the house 14 from the storage encasement 16 and simultaneously the left front support member 30A, right front support member 30B, left rear support member (not shown) and right rear support member (not shown) will begin to unfold extending upward. Then the top pivoting hinge 32 pivots outward straightening the middle portion and the upper portion of the support members. Then the support members will rotate inwardly around their respective pivotal anchor causing the top surfaces of the left tarp 20A and right tarp 20B to be drawn over the roof of the house 14 as shown in FIG. 3. The left front support member 30A, right front support member 30B, left rear support member (not shown) and right rear support member (not shown) will continue to rotate inward and extend further upward. The further upward extension is caused by the four top pivotal hinges 32 pivoting outward. This continues drawing the three surfaces of both the left tarp 20A and right tarp 20B into their upward position completely enclosing the house 14 as shown in FIG. 4, thereby isolating the house 14 from a fire source.
When the fire resistant house cover 10 moves from the upward to the downward position the above sequence will be repeated in reverse. The front winch 26A and rear winch 26B will lower the left tarp 20A and right tarp 20 downward. Simultaneously the support members will rotate outward over the roof of the house 14 and then fold downward with the left tarp 20A and right tarp 20B into the storage encasement 16. The storage encasement cover 18 will then have to be manually rotated over the storage encasement. Also, the left front tarp cable 22A, right front tarp cable 22B, left rear tarp cable 22C and right rear tarp cable 22D will have to be manually placed into their respective tarp cable clip 34.
It will be understood that each of the elements described above, or two or more together, may also fund a useful application in other types of constructions differing from the type described above.
While the invention has been illustrated and described as embodied in a fire resistant house cover, it is not intended to be limited to the details shown, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
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The present invention relates to a fire isolation device for a free standing structure. This device includes a left tarp and right tarp fabricated from a fire resistant material. The left tarp and right tarp are of a size to completely enclose the free standing structure. Attached to the left tarp and right tarp is a support structure, which is capable of moving from an upward position where the left tarp and the right tarp completely enclose the free standing structure to a downward position where the left and right tarp expose the free standing structure. This device also includes a moving mechanism for moving the plurality of support members from the downward position to the upward position.
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RELATED APPLICATIONS
This application claims benefit from U.S. Provisional Application for Patent Application No. 62/298,038 filed Feb. 22, 2016, which is hereby incorporated by reference in its entirety.
BACKGROUND
The field of the present device and method relates to spring-loaded animal traps, and more particularly, to catch release mechanism for a spring-loaded animal trap, such as a mouse trap, animal trap, or the like.
With standard mouse traps, also known as snap traps or spring-loaded arm bar mouse traps, the catch serves two primary purposes, to restrain the holding arm bar when the trap is set and to hold the bait. In order for the trap to activate, the rodent must apply sufficient force on the catch through the eating or manipulation of the attached bait to cause the catch to release the holding arm bar. It is too often the case that the mouse can gently eat the bait without activating the trap. Thus, when later checked, the trap may still be set, yet the catch cleaned of the bait. What is needed is a trap that senses more than just direct pressure on the catch and accounts for other movements or applications of force applied on other portions of the trap.
SUMMARY
The present improved animal trap and unique catch release mechanism or snap trap actuator eliminates substantial eating or removal of the bait without the trap activating and provides a dual means to activate the trap. This is accomplished by the present catch release mechanism having a sliding member which slides within a hole through the platform of the trap under the influence of gravity and a prop which holds at least a portion of the trap platform above a support surface. When the prop is destabilized by an external force (e.g., applied by a rodent on any part of the trap), the prop's support of the platform is disturbed, permitting the platform to fall toward the support surface. The platform falls relative to the sliding member; and the sliding member is forced toward the catch by contact with the support surface, thus pushing the catch so that the catch releases the holding arm bar to activate the trap.
In a first embodiment, an animal trap is provided and generally comprises a platform having a top surface with a first section, a second section, and a middle section located between the first section and the second section; a catch attached to the top surface, the catch being to move relative to the top surface; a pivoting kill bar hammer rotationally attached to the middle section of the platform and being biased towards the second section; a holding arm bar with a proximal end and a distal end, the holding arm bar attached through a pivot to the first section of the platform by the proximal end, when in a set configuration the distal end of the arm bar releasably coupled to the catch to hold the kill bar hammer toward the first section; and a catch release mechanism comprising a sliding member and a prop, the prop supporting the platform in a tilted orientation above the support surface; where, when the prop is destabilized, the platform drops downwards to push the sliding member upwards by contact with the support surface and into the catch causing the catch to move and release the distal end of the holding arm bar to permit the pivoting kill bar hammer to return towards the second end.
Optionally, the platform may further comprise a bottom surface opposite the top surface, the prop is pivotally connected to the bottom surface. The prop may be attached to or separable from the platform or other part of the trap. The prop may have a tapered end. The platform may have a through hole into which the sliding member is inserted, a portion of the sliding member is positioned beneath the catch when in the set configuration. As an option, the sliding member comprises a rod and the portion of the sliding member is an enlarged head. The sliding member may further comprise an enlarged base, the enlarged head is positioned above the top surface and the enlarged base is positioned below the top surface to trap the sliding member within the through hole. The rod of the sliding member may slide freely within the through hole.
In the set configuration, the prop holds a second portion of the platform a distance above the support surface with the enlarged base held slightly above the support surface and the enlarges head resting on the top surface. The prop may be destabilized by movement of the platform or any part of the trap. Optionally, the bait can be applied to the catch release mechanism and/or the second section of the platform.
In another embodiment, an animal trap is provided and generally comprises a platform comprising a top surface that supports a pivoting kill bar hammer, a catch, and a holding arm bar, in a set configuration, the pivoting kill bar hammer repositioned from an initial position against a bias and held in a set position by the holding arm bar releasably coupled to the catch; and a catch release mechanism comprising a sliding member and a prop, the prop supporting the platform in a tilted orientation above the support surface; where, when the prop is destabilized, the platform drops downwards to push the sliding member upwards by contact with the support surface and into the catch causing the catch to move and release the distal end of the holding arm bar to permit the pivoting kill bar hammer to return towards the initial position.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a perspective view of the embodiment of the present animal trap with the catch release mechanism;
FIG. 2 is a partial cross-sectional perspective view of the embodiment of FIG. 1 more clearly illustrating the catch release mechanism;
FIG. 3A is a magnified partial cross-sectional perspective view of FIG. 2 , showing the animal trap in the set configuration;
FIG. 3B is a magnified partial cross-sectional perspective view of FIG. 2 , showing the animal trap in the activated state or configuration;
FIG. 4A is a side view of the animal trap of FIG. 1 , showing the animal trap in the set configuration; and
FIG. 4B is a side view of the animal trap of FIG. 1 , showing the animal trap in the set activated state or configuration.
LISTING OF REFERENCE NUMERALS OF FIRST-PREFERRED EMBODIMENT
animal trap 20
platform 22
catch 24
pivoting kill bar hammer 26
holding arm bar 28
catch release mechanism 30
top surface 32
bottom surface 34
first section 36
second section 38
middle section 40
catch staple 42
catch hook 43
bait holder 44
catch bottom surface 45
catch distal end 46
rod 48
rod staple 50 , 52
bar staple 54
bar proximal end 56
bar distal end 58
hammer spring 60 , 62
sliding member 64
prop 66
tapered end 68
through hole 70
sliding rod 72
enlarged head 74
enlarged base 76
support surface
arrow A 1 , A 2 , A 3 , A 4 , A 5 , A 6 , A 7 , A 8 , A 9
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The detailed descriptions set forth below in connection with the appended drawings are intended as a description of embodiments, and is not intended to represent the only forms in which the present securement system may be constructed and/or utilized. The descriptions set forth the structure and the sequence of steps for constructing and operating the securement system in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent structures and steps may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention.
Referring first to FIGS. 1 and 2 , an animal trap ( 20 ) is disclosed, generally having a wood platform ( 22 ) (although other materials may be used, such as metal, plastic, linoleum, acrylic glass, or a platform with a veneer to match the support surface, etc.) with a top surface ( 32 ) having a first section ( 36 ), a second section ( 38 ), and a middle section ( 40 ) between the first section ( 36 ) and the second section ( 38 ). The sections ( 34 , 36 , 38 ) are not precisely delineated, but instead, represent three general areas of the top surface ( 32 ) upon which various parts of the trap ( 20 ) may be positioned.
A bar staple ( 54 ) is located within the first section ( 36 ), with the holding arm bar ( 28 ) attached to the bar staple ( 54 ) by a loop on the end to create a pivoting attachment. Of course, because the bar staple ( 54 ) is U-shaped with the end of the holding arm bar ( 28 ) looped about it, the holding arm bar ( 28 ) is permitting to pivot and move about the bar staple ( 54 ) in multiple directions. The pivoting kill bar hammer ( 26 ) is generally made from a single wire bent into a rectangular shape, with one side of the rectangle held, much like an axle, by a first rod staple ( 50 ) and a second rod staple ( 52 ) pinned to the middle section ( 40 ) of the top surface ( 32 ). One or more springs ( 60 , 62 ) (such as a torsion spring) biases the rotation of the pivoting kill bar hammer ( 26 ) towards the second section ( 38 ) of the top surface ( 32 ) with enough force and impulse to capture a rodent between the pivoting kill bar hammer ( 26 ) and the second section ( 38 ). A catch staple ( 42 ) pivotally holds the catch ( 24 ) to the top surface ( 32 ) within or near the middle section ( 40 ). The catch ( 24 ) includes a bait holder ( 44 ) and a catch hook ( 43 ) configured to engage the distal end ( 58 ) of the holding arm bar ( 28 ) when the animal trap ( 20 ) is in the set configuration, as shown in FIG. 1 .
As with standard spring-loaded traps, in the set configuration, the pivoting kill bar hammer ( 26 ) is rotated from the second section ( 38 ) and towards the first section ( 36 ) against the biasing force of the springs ( 60 , 62 ). As the pivoting kill bar hammer ( 26 ) is manually held towards the first section ( 36 ), the holding arm bar ( 28 ) is rotated over the pivoting kill bar hammer ( 26 ) such that the proximal end ( 58 ) of the holding arm bar ( 28 ) touches the pivoting kill bar hammer ( 26 ) to arrest its movement. Then, the distal end ( 58 ) of the holding arm bar ( 28 ) is positioned beneath the catch hook ( 43 ) so that the distal end ( 58 ) pushes up on the catch hook ( 43 ) to provide a temporary engagement. If activated, the spring force acting on the pivoting kill bar hammer ( 26 ) will cause the distal end ( 58 ) to disengage from the catch hook ( 43 ) swing back, and release the pivoting kill bar hammer ( 26 ) so that it strikes the second section ( 38 ) of the top surface ( 32 ).
The catch release mechanism ( 30 ) is illustrated more clearly in the partial cross-section of FIG. 2 . The illustrated embodiment of the catch release mechanism ( 30 ) comprises a sliding member ( 64 ) positioned in a through hole ( 70 ) formed through the platform ( 22 ), from the top surface ( 32 ) to the bottom surface ( 34 ). The sliding member ( 64 ) is permitted to axially slide within the through hole ( 70 ), preferably freely sliding or with little resistance. The through hole ( 70 ) may be lined with a tubular liner made of plastic, metal, or other material that permits the sliding member ( 64 ) to slide without undue friction or binding. When the platform ( 22 ) is lifted above the support surface (S), under the influence of gravity, the sliding member ( 64 ) slides downward towards the earth. An enlarged head ( 74 ) is connected to a top end of the sliding member ( 64 ) and is positioned above the top surface ( 32 ) and beneath the catch ( 24 ). An enlarged base ( 76 ) is connected to a bottom end of the sliding member ( 64 ) and is positioned beneath the bottom surface ( 34 ) of the platform. The enlarged head ( 74 ) and the enlarged base ( 76 ) limit the travel of the sliding member ( 64 ) so that the sliding member ( 64 ) remains in the through hole ( 70 ). Further the enlarged head ( 74 ) is sized so that it pushes upon the catch ( 24 ) (preferably on the catch distal end ( 46 ) or any other portion) when the sliding member ( 64 ) slides upwards towards the top surface ( 32 ). The enlarged head ( 74 ) and the enlarged base ( 76 ) may be made of various materials, such as metal, plastic, and such. The enlarged base ( 76 ) may further include a rubber foot to enhance grip on the support surface (S). The sliding member ( 64 ) may be a rod, tube, strip, square stock, or any other configuration that permits sliding within the through hole ( 70 ).
Still referring to FIG. 2 , the catch release mechanism ( 30 ) further comprises a prop ( 66 ) or other support that provides an unstable support to hold at least a portion of the platform ( 22 ) above a support surface (S). In the present example embodiment, the prop ( 66 ) is a small wood board with a tapered end ( 68 ). However, the prop may be made of a length of wire, a rod, a rectangular sick, toothpick-like structure, nail-like structure, or any other configuration that provides temporary support of the platform ( 22 ) that is easily destabilized by an external force applied to any or most any portion of the animal trap ( 20 ). In the illustrated example, the prop ( 66 ) is stood between the bottom surface ( 34 ) of the platform ( 22 ) and the support surface (S), held in place through frictional engagement with both surfaces. In an alternate embodiment (not shown), a wire hinged to a staple on the bottom surface ( 34 ) provides a prop which acts as an unstable support. Thus, the prop ( 66 ) may be permanently attached to the trap ( 20 ) or temporarily engaged.
Referring to FIG. 3A , a magnified view of FIG. 2 is provided to more clearly illustrate the operation and components of the present catch release mechanism ( 30 ). This figure, as well as and FIG. 4A , illustrates the animal trap ( 20 ) in the set or armed configuration, with the prop ( 66 ) supporting the second section ( 38 ) a distance above the support surface (S) and the first section resting on the support surface (S), forming a lean-to like arrangement. In the illustrated embodiment, the height of the prop ( 66 ) is sufficient to permit the sliding member ( 64 ) to slide downward within the through hole ( 70 ), so that the enlarged head ( 74 ) rests on the top surface ( 32 ) and the enlarged base ( 76 ) is held slightly above the support surface (S). Although, in another embodiment (not illustrated), the enlarged base ( 76 ) rests upon the support surface (S), holding the enlarged head ( 74 ) slightly above the top surface ( 32 ). Arrows (A 1 , A 2 ) illustrate that the prop ( 66 ) is permitted to collapse or fall in any direction if the platform ( 22 ) were to be shifted or jarred relative to the support surface (S). The frictional engagement between the prop ( 66 ) and the support surface (S) and the platform ( 22 ) is easily overcome by movement, vibration, shifting, or other forms of contact between an animal and the trap ( 20 ). Arrow (A 3 ) illustrates the up and down axial movement of the sliding member ( 64 ) within the through hole ( 70 ).
FIGS. 3B and 4B illustrate the animal trap ( 20 ) in the triggered or activated configuration, after an animal has applied a force to the platform ( 22 ), the catch ( 24 ), the enlarged head ( 74 ), the prop ( 66 ), or any other portion of the animal trap ( 20 ). As discussed above, a sufficient external force applied by the animal will cause the prop to break contact and slide relative to one or both of the support surface (S) and the bottom surface ( 34 ). Arrow (A 8 ) illustrates the prop ( 66 ) falling down and permitting the platform ( 22 ) to drop toward the support surface (S) under the influence of gravity.
As the platform ( 22 ) drops down, the enlarged base ( 76 ) of the sliding member ( 64 ) contacts the support surface (S), which pushes upwards on the sliding member ( 64 ) pushing the sliding member ( 64 ) upward and toward the catch ( 24 ). Because the enlarged head ( 74 ) is positioned beneath the catch ( 24 ), upward movement of the sliding member ( 64 ) (indicated by arrow (A 7 )) causes the enlarged head ( 74 ) to rotate or otherwise move the catch ( 24 ) about the staple ( 42 ), as indicated by arrow (A 6 ), to disengage the catch hook ( 43 ) from the distal end ( 58 ) of the holding arm bar ( 28 ), to release the holding arm bar ( 28 ) and permit its rotation (as indicated by arrow (A 4 )) under the spring force of the pivoting kill bar hammer ( 26 ) rotating back toward the second section ( 38 ) (as indicated by arrow (A 9 )), thus trapping the animal.
With the present animal trap ( 20 ), the catch may be released in two ways, first, by the traditional manner where the animal torques the catch itself or by simply shifting the platform ( 22 ) to knock over the prop ( 66 ). The bait (peanut butter, etc.) may be placed on the catch ( 24 ), on the enlarged head ( 74 ), on the top surface ( 32 ), or any portion of the animal trap ( 20 ) which would position the animal between the platform ( 22 ) and the pivoting kill bar hammer ( 26 ) when the trap ( 20 ) is activated. Although the sliding member ( 64 ) is shown with an enlarged head ( 74 ) and enlarged base ( 76 ) these are illustrative of just one embodiment, and are not required. An alternate sliding member may include a wire inserted through the through hole ( 70 ), with the ends of the wire bent at a ninety degree angle to prevent retraction. The present animal trap ( 20 ) provides a substantially increased level of sensitivity and easily activates upon the slightest nudge, even while the animal is merely investigating the bait. Thus, consumption of the bait is not required to activate the trap.
While particular forms of the present securement system have been illustrated and described, it will also be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the design. Accordingly, it is not intended that the invention be limited except by the claims.
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The present improved animal trap and unique catch release mechanism eliminates substantial eating or removal of the bait without the trap activating and provides a dual means to activate the trap. This is accomplished by the present catch release mechanism having a sliding member which slides within a hole through the platform of the trap under the influence of gravity and a prop which holds at least a portion of the trap platform above a support surface. When the prop is destabilized by an external force, the prop's support of the platform is disturbed, permitting the platform to fall toward the support surface. The platform falls relative to the sliding member; and the sliding member is forced toward the catch by contact with the support surface, thus pushing the catch so that the catch releases the holding arm bar to activate the trap.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to an apparatus and a method for the automatic regulation and control of an irrigation of plants in accordance with the preamble of the independent patent claims. It relates, in particular, to an apparatus and a method for an optimized irrigation time without water excess and without the soil drying out.
[0003] 2. Description of Related Art
[0004] When plants are irrigated, in particular lawns or agricultural land, use is made of irrigation systems that are controlled by a timer. The user can set, on the latter, both the instant and the duration of the irrigation, there being on the market various timers for the control of a variety of irrigation zones and with different levels of complexity.
[0005] This type of irrigation control is low in flexibility, that is to say irrigation is performed over the preset time duration and at the preset instants, irrespective of the effective need of the plants that are to be irrigated.
[0006] So-called rain sensors are also known that, when rain is falling, measure the amount of rain and block the timer when a defined amount is exceeded so that no irrigation is performed while it is raining.
[0007] It is true that this method avoids an irrigation during or after a rain event. For example, in cool or rainless weather irrigation is performed, however, though sufficient moisture is present in the soil and there is thus no need to irrigate.
[0008] In recent years, soil moisture sensors have been connected to timers. These sensors measure the current moisture in the soil and enable the timer, and thus initiate watering, only upon falling below a critical soil moisture that can be set. Most of these soil moisture sensors are expensive to procure and maintenance-intensive, and the measurement result depends strongly on other parameters, such as the fertilizer content. They have therefore not been able to establish themselves on the market. However, a novel soil moisture sensor that does not have these disadvantages has also been developed in accordance with WO 2006/081693.
[0009] Such an improved soil moisture sensor can now be used to prevent irrigation from being performed unnecessarily. However, the amount of water administered per watering cycle is still set by the user on the timer, and is therefore fixedly prescribed. The amount of water effectively required can, however, deviate strongly from the set amount, and it also varies with short term and long term climatic fluctuations. Experience shows that in the case of crops, in particular, once a watering time has been set, users tend to adapt to the current climatic conditions only in exceptional cases and mostly not change it throughout the entire year.
[0010] When consideration is given to the ever more topical problems associated with rising water consumption, particularly in countries with scarce water reserves, the aspect of carefully managing water as a resource becomes very important. The avoidance of unnecessary water consumption belongs here, as well. Immense quantities of water (80% of the entire water consumption) are used globally in the irrigation of crops and green areas. It is estimated that half thereof could be saved by intelligent irrigation.
[0011] It is therefore an object of the invention to provide an intelligent method for the control and regulation of an irrigation time with the aid of which, with an automatically set watering time, no excess water is poured and, on the other hand, the soil is prevented from drying out.
BRIEF SUMMARY OF THE INVENTION
[0012] The object is achieved by the method according to the invention as it is described in the patent claims. The invention also includes an apparatus with the aid of which the method can be carried out, and an electronic regulation that can be installed in an appropriate apparatus.
[0013] The method relates to an intelligent method for the control of irrigation that, on the one hand, is capable of automatically fixing an irrigation time such that no excess of water is poured. On the other hand, the soil is also prevented from drying out. The method is also capable of automatically compensating short term, medium term and long term temperature changes such as occur in the course of a year, preferably in such a way that an optimum amount of water is always poured even without manual intervention. When crops are irrigated they also require more and more water with increasing size and/or leaf area. The inventive method takes account of application specific conditions such as system parameters and environmental parameters, and is also capable of automatically compensating an increase in demand as described.
[0014] The method is based on a novel evaluation of the soil moisture time profile measured by a soil moisture sensor. In particular, the soil moisture sensor described in WO 2006/081693 can be used to this end. However, it is also possible to use any arbitrary soil moisture sensor that permits electronic measurement of moisture values. A sensor is then combined with the inventive electronic regulation and/or appropriate evaluation electronics, for example in the form of a chip.
[0015] The soil moisture is repeatedly measured with the aid of a soil moisture sensor and appropriate evaluation electronics in the method for the regulation and control of an automatic irrigation device. The time profile of the soil moisture is analyzed in this case before and after an irrigation operation, and an irrigation time is calculated from a moisture value before irrigation and a moisture value after an irrigation. A system specific characteristic K is considered in the calculation of the irrigation time, said characteristic preferably being determined in an initial calibration measurement and checked and adapted in subsequent measuring steps.
[0016] The regulation of the inventive apparatus is preferably designed such that even when environmental conditions and plant size change, on the one hand the plant is always supplied sufficiently with moisture, but on the other hand not too much water seeps unused into the soil.
[0017] A moisture scale used in this case has two limit values that can be set: in the direction “dry”, the limit value that fixes a minimum moisture, and the limit value that fixes a maximum moisture are defined by an input from the user. In the direction of higher moisture, a further limit value “wet” is reached when the soil is saturated with water. This limit value is defined in advance, that is to say is system-induced, for a sensor in use, because a sensor cannot become wetter than wet. An aim of the control is now, on the one hand, not to fall below the limit value for “dry” excessively, including over a lengthy time, so that the plants do not suffer drought damage and are not exposed to drought stress. On the other hand, however, it is also important that the limit value for “moist”, which corresponds at most to that of “wet”, be reached only for a short time, because additional water would seep away and could not be used by a plant.
[0018] In order that the local conditions relating to soil composition as well as to water ingress per unit area are taken into account from the start in a regulation, at the beginning of the method, this is, as a rule, at the start of an irrigation period, preferably a calibration measurement is carried out. In this case, a soil moisture sensor is introduced into a soil to be irrigated. It is preferably inserted to a specific depth. This depth is dependent on the position of the roots and lies in a preferred range of 5-30 cm. Irrigation is then performed briefly, preferably by an existing sprinkler or a drip fed irrigation. Depending on the soil permeability, this irrigation will be detected earlier or later by an increase in the moisture content at the sensor. The time covered up to this detection is, on the one hand, a measure of the permeability of the soil but also, on the other hand, of the water ingress at the location of the sensor.
[0019] The ratio of the difference in moisture value before the irrigation and moisture value after the irrigation to the time of the irrigation can be regarded as a user specific characteristic K. K takes account both of the local soil composition and of the installed irrigation performance. The characteristic K tells us by how much a moisture value changes when pouring is performed over a specific time, for example one minute, and with a specific amount of water. This factor K is determined automatically during the calibration step initially carried out, this corresponding in essence to a first measurement, and is used for the further measurements. It would also be possible to input an initial value of K, for example in accordance with empirical values, in advance. A subsequent regulation adapts the characteristic as appropriate to the prescribed moisture limit values.
[0020] In a preferred embodiment of the method, the characteristic K is repeatedly checked, preferably cyclically, it also being possible for an irrigation to be performed cyclically. In this case, K is compared, preferably after a measurement that is performed after an irrigation, with an upper limit value that corresponds to a moist soil. Depending on the desired/actual value deviation, K is enlarged or reduced by a factor. Since K is inversely proportional to the irrigation time in the present calculations, a reduction of K is apposite when the irrigation time is to be lengthened, that is to say when, for example, a measured moisture value has not reached an upper moisture limit value after an irrigation. An enlargement of the characteristic K that therefore leads to a reduced calculated irrigation time is apposite when an upper limit value “moist” is reached after the irrigation, but the aim is to prevent this limit value from being exceeded too far. It is preferred to choose a moisture value below a moisture limit value for a completely wet soil as an upper limit value. It is also possible thereby to determine an exceeding of the limit value.
[0021] In practice, an upper limit value that defines a water saturated state corresponds to that soil moisture for which the soil is saturated with water so far that no more water seeps into the subsoil because of gravity. This property of the soil is denoted as field capacity (GW FK ). Sandy soils have a low field capacity, while soils with a high proportion of organic materials such as peat or humus have a high field capacity. Such a moisture limit value based on the field capacity can therefore lie below a limit value for a “wet” soil.
[0022] The calibration operation described above can also be used to determine such a field capacity automatically. To this end, irrigation is continued after the characteristic K has been determined over a lengthy time, for example 1-2 hours. It is to be ensured that the soil is supersaturated. After a lengthy waiting time, for example of 2-12 hours, it can be assumed that the excess water has run off into the subsoil. The moisture value is then determined again and this corresponds to the field capacity GW FK , and can be stored in the system. When there is a manual input of an upper limit value “moist” that overshoots the GW FK , the user can now be alerted to this circumstance, for example by an alarm report. It would also be possible for the upper limit value “moist” to be set automatically to the moisture value corresponding to the field capacity.
[0023] In a further embodiment of the method, an irrigation time calculated automatically with a characteristic K is increased or decreased directly by a factor D, that is to say by an amount of water given in a prescribed irrigation device. Such a fixed supply or removal of water determined by concrete measurements can be advantageous when, for example, agricultural land is to be kept wet or moist or less moist over a somewhat longer time. In the case of a calculated irrigation time, an amount of water is optimized to an optimum relationship between saving water and drying out. However, a customary moisture sensor cannot be used to distinguish between wet, somewhat too wet or much too wet. A higher supply of water through a change in the characteristic K can elude accurate monitoring. If the aim is now to keep an area moist or wet or less moist over a somewhat lengthy time, this can be achieved by the supply of, or reduction by a defined amount of water. With certain limitations, this can also be achieved by reducing or decreasing the moisture limit values.
[0024] An exceeding of a maximum amount of water on purpose, that is to say an exceeding of the amount of water that is sensible in accordance with a field capacity GW FK , can, for example, be apposite when, by way of example, the aim is to prevent the soil from being salted. An excess of water ensures that the salt cannot accumulate in the critical root area.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Different stages and aspects of the method, as well as preferred embodiments of the method, are explained in more detail below with the aid of exemplary figures. In the drawing:
[0026] FIG. 1 shows the calibration measurement and the determination of the field capacity; and
[0027] FIG. 2 shows a soil moisture profile.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The graph in FIG. 1 shows the profile of the moisture level F against time Z. The soil moisture content is measured at regular intervals Mn, Mn+1, Mn+2 . . . . At the instant Mn, the soil moisture content is still above a set limit value GWdry that corresponds to a minimum soil moisture that is to be reached. At the instant of the following measurement Mn+1 at the instant t 0 , the soil moisture content, the first moisture value FW 1 , is below the set limit value GWdry. An irrigation operation is correspondingly initiated and terminated at the instant t 1 . The instant t 1 or the irrigation time t 1 -t 0 is preferably selected to be very short, for example 5 min., for a calibration measurement, in order to reliably prevent over-irrigation. At a second instant t 2 , a control measurement, for example approximately ½ hour after the irrigation, is carried out, and a further moisture value FW 2 is measured. Thereafter, the system determines a characteristic K from the measured values in accordance with the specified formula:
[0000]
K
=
FW
2
-
FW
1
t
1
-
t
0
.
[0000] The characteristic K is stored in the system.
[0029] The measurement operation can also be carried out in two or more stages, t 1 -t 0 then corresponding to the total time over which irrigation has been performed. The result of the calibration measurement is used to determine the irrigation time for the following measurements.
[0030] After the measurement at the instant t 2 , the irrigation is continued, preferably over a longer time, for example 1-2 hours, up to the instant t 3 . A waiting time, preferably of several hours, is inserted thereafter. A measurement is carried out anew at the instant t 4 . The measured value GW FK corresponds to the field capacity. In the case of a humus rich soil, this can be equal to GWwet. The determination of GW FK can also be undertaken or omitted independently of the calibration measurement.
[0031] FIG. 2 shows a typical profile of the soil moisture, and the principle of a continuous correction of the irrigation time in combination with a preceding calibration measurement.
[0032] After the calibration measurement, preferably in accordance with FIG. 1 , the first regular measurement is carried out at the instant Mn+2. Since the current moisture value FWn+2 lies under GWdry in the example shown, an irrigation is initiated. The irrigation time BDn+2 is now calculated as follows using the measured moisture value FWn+2 and the characteristic K determined in accordance with the calibration measurement:
[0000] BDn+ 2=( GW moist− FWn+ 2): K
[0033] After the irrigation, the moisture value is determined in turn by a control measurement. In the example shown, the intended target value GWmoist has not yet been reached (Delta>0), that is to say the irrigation time was still too short, the factor K determined in the calibration measurement too large.
[0034] The system now calculates the irrigation time BD for the following irrigation Mn+3 as follows: the difference between the target value GW and the current moisture (GWmoist FWn+2) before the measurement Mn+2 is divided by a characteristic K reduced by x. As a result, a longer duration is obtained for the subsequent irrigation at the instant Mn+3. The corresponding formula reads as follows:
[0000] BDn+ 3=( GW moist− FWn+ 3):( K−x )
[0035] It is now assumed, in the example shown, that the target value GWmoist has been reached owing to the correction performed, and this is confirmed by a subsequent control measurement.
[0036] This would mean the target has been reached, and it is possible as shown previously to regulate further or, given conditions which are not changing, to irrigate straight away.
[0037] If GWwet has been selected as an upper moisture limit value, the problem resides in the fact that it is not known whether too much water has not been given, since the sensor cannot display a “too much”. It can therefore be assumed as a precaution that too much has been poured without, however, being able to know this.
[0038] The way in which this problem is solved is preferably that whenever GWwet is reached a small negative deviation of specific magnitude is automatically adopted, and this is included in the calculation of the duration for the following irrigation. The characteristic K is enlarged in this case by a factor y.
[0039] The appropriate formula then reads as follows:
[0000] BDn+ 5=( GW wet− FWn+ 3):( K+y )
[0040] A reduction in the irrigation time via an enlargement of K can also be desired given a selected moisture limit value GWmoist, for example when the aim is to keep a watering deep on purpose, by way of example in order to save as much water as possible or to keep plants not too moist as far as possible. A multiplication factor can also be selected instead of the factors x, y that are to be subtracted and added. This factor would then be correspondingly smaller or larger than 1.
[0041] Since the moisture is still high at the instant Mn+4 in the example of FIG. 2 , that is to say lies above GWdry, no irrigation is initiated. However, at the instant Mn+5, the lower limit value GWdry is undershot, and an irrigation with the calculated period BDn+5 is started.
[0042] Should there be rain between the measuring points Mn and Mn+i, this is of no consequence, since the next irrigation is only initiated once GWdry is undershot. If it begins to rain just before a measurement, the measurement is interpreted in a more or less incorrect fashion depending on the amount of rain and duration, but this is automatically corrected again in the subsequent measurement.
[0043] In conventional measurement cycles, measurements are carried out, as a rule, every few hours, for example every 3-6 hours. If a measurement cycle Mn, Mn+1, . . . is selected to be very short, however, for example every half hour, it is possible to dispense with control measurements after an irrigation since said measurements fall into the regular measurement cycle. In the case of short measurement cycles, it should be ensured that use is made of moisture sensors with a low energy consumption.
[0044] With the aid of said regular algorithm, one is now able to set up an irrigation control which does not demand of the user any sort of knowledge relating to the nature of the soil, water input per m 2 and irrigation time. After the sensor has been placed in the soil, the system is started, calibrates itself and automatically regulates the irrigation time so as to attain an optimum soil moisture cycle.
[0045] All that the user needs to set as a function of the plants to be irrigated are the two limit values GWdry and GWmoist. The system can be fashioned such that a table presented by the system can be used to select sensible values that are then taken over as constants.
[0046] The determination of the measurement cycles can be performed in a way similar to the timers currently available. The latter mostly permit the setting of the start time and the duration of an irrigation, it also being possible by installing a photodiode to record the day/night cycle and, correspondingly, to determine the beginning of an irrigation by day or at night. Moreover, the minimum duration between two irrigations can be defined.
[0047] In the limit case, problems can arise owing to the inflexible stipulation of the minimum duration between, for example three irrigations, for example three day cycles, that is to say irrigation every third night, by way of example. Specifically, this means when supply of water stored in the ground is insufficient in a phase of high temperature or given crops with a very high water requirement in order to meet the requirement of this time, the result being that drought stress occurs for the plants.
[0048] The regulation described here can, however, recognize such a case very easily and preferably shorten the duration between two cycles automatically. For example, if the moisture value at the time of measurement undershoots a specific critical dry limit value several times in succession, although the regulation has respectively adapted the irrigation time upwards, this is a clear indication that the irrigation cycle has been selected to be excessively long. In such a case, the system can, for example, make a report, or automatically reduce the cycle duration. It is appropriate to display or report, in particular, if an irrigation cycle is permanently prescribed in a system, for example, because of weather conditions (sun), because of use (meadow or swimming pool) or because of regulations (irrigation only at specific times). If, for example, a moisture limit value “dry” is then undershot several times, it is not permissible to increase the irrigation time on the basis of the external conditions.
LIST OF REFERENCE SYMBOLS AND FORMULAE
[0000]
Mn, Mn+1 . . . Moisture measurement n, n+1, . . . at predetermined, regular time intervals
t 0 , t 1 , t 2 . . . Instants at which an action is initiated and stopped (for example measurement, start/stop of an irrigation, etc. . . . )
F Moisture value (of a substrate, for example, earth, lawn etc.)
FW 1 , FW 2 First, second measured moisture value
GWdry; GWmoist Limit values “dry”, “moist” that can be set
GW FK Moisture limit value corresponding to the field capacity
GWwet Fixed limit value “wet”
characteristic K=FW 2 −FW 1 /t 1 −t 0
System characteristic that is determined by calibration measurement and takes account of user specific details Irrigation time BD=GWmoist−FW/K Irrigation time calculated with the aid of measured and determined values
x,y Correction factors for K for the optimized calculation of the irrigation time after an excessively short or excessively long irrigation time.
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A method for the automatic irrigation of plants, wherein the temporal progression of soil moisture is determined from measured soil moisture values, and said progression is used for the calculation of an optimized irrigation time duration, such that both water excess in the soil and soil drying are avoided as much as possible. Preferably, the time duration of irrigation is constantly evaluated and optimized using comparisons of measured values with prespecified moisture- and dryness threshold values (GWmoist, GWdry), and automatically adjusted to changing environmental conditions and/or plant requirements.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a liquid crystal device for displaying information and to a method from producing such a device. More specifically, to a device having liquid crystal material stabilized by a support layer of material. In one embodiment, the support layer acts as a light shutter for information supplied underneath the liquid crystal support layer. For example, the liquid crystal material is coated on at least one side of a layer of absorptive material such as paper to dimensionally stabilize the thickness and uniformity of the liquid crystal material to provide an effective light shutter in the completed device. Examples of a liquid crystal device according to the present invention include a temperature sensitive label, a variable information display for example to be fixed substantially permanently on an instrument or part, and other types of fixed or variable information display devices.
[0003] 2. Prior Art
[0004] Liquid crystal displays are in common use today such as on calculators, portable computers, office equipment including printers and copiers, etc. These displays are used on these devices for providing variable information to users such as numbers, letters, other indicia such as, sensing indicator displays and other types of information. Most of these common devices provide a variable information display by activating a layer of liquid crystal material by changing the electrical and/or magnetic field, or changing the temperature such as by heating specific points in the layer of liquid crystal.
[0005] Typically, in these prior art devices liquid crystal cells are implemented for the display. The liquid crystal cells are defined by structure for containing a layer of liquid crystal due to the liquid nature of this material. The container is necessary to provide a layer of liquid crystal of sufficient thickness to provide an effective display in combination with maintaining the thickness of the layer throughout the entire plane of the display. Improved liquid crystal cells are constructed by providing ground glass particles or beads of a specific layer thickness for maintaining a fixed distance between the plates of the cell during construction and use of the display.
[0006] Other displays provide uniform thickness liquid crystal layers by microencapsulating liquid material in a matrix such as plastic resin, which is cast or machined into a uniform layer. Still others devices appear to form a liquid crystal composition that includes chemical components to dimensionally stabilize the layer by changing the phase of the material to a solid.
SUMMARY OF THE INVENTION
[0007] Accordingly, it is a primary object of the present invention to form a display device having a layer of liquid crystal stabilized by a support layer of material.
[0008] Another object of the present invention is to provide an improved liquid crystal display.
[0009] A further object of the present invention is to provide a liquid crystal display according to the present invention in the format of a label.
[0010] A still further object of the present invention is to provide a liquid crystal display having a support layer of absorptive material impregnated with liquid crystal material.
[0011] An even further object of the present invention is to provide a liquid crystal display having a support layer of absorptive material impregnated with liquid crystal material, which support layer becomes translucent upon being coated by the liquid crystal material.
[0012] An even still further object of the present invention is to provide a liquid crystal display having a support layer of material stabilizing a layer of liquid crystal material.
[0013] Another object of the present invention is to provide a method of making the liquid crystal display according to the present invention.
[0014] A further object of the present invention is to provide a method of making the liquid crystal display according to the present invention including coating a support layer of absorptive material on at least one side, preferably both sides, with liquid crystal material to form a light shutter, layering the support layer between a base layer and a covering layer, and providing information to be displayed on either the support layer or the base layer, or both.
[0015] A still further object of the present invention is to provide a method of making the liquid crystal display according to the present invention including coating a support layer on at least one side, preferably both sides, with liquid crystal material to form a light shutter, layering the support layer between a base layer and a covering layer, and providing information to be displayed on either the support layer and or base layer, or both.
[0016] These and other objects of the invention are accomplished by providing a display device having a support layer made of material capable of absorbing or binding liquid crystal material. The support layer is provided with liquid crystal material on at least one side, which contains or binds the liquid crystal material so as to make the layer of liquid crystal dimensionally stable in thickness and of sufficient thickness to perform as an effective light shutter. The support layer must dimensionally stabilize the liquid crystal layer in a manner so as not to interfere with the chemical properties, or only effect the chemical properties to a limited extent, so that the liquid crystal layer can function properly chemically in a specific display design by for example acting as a light shutter and/or changing color. Examples of support layers include various papers (including various cellulose based materials), felts and clothes or combination thereof that do not chemically react to the various liquid crystal materials. Further examples include composite layers of papers, felts or clothes in combination with synthetic materials (e.g. plastic) or layers to bind the liquid crystal within a matrix. The exact physical and chemical properties of the paper, cloth, felt or composite such as the sizing, weight, color, residual chemicals, layering, composition, fiber size, etc. can be controlled or selected to optimize the display characteristics of the device for a specific application.
[0017] Another important property of the support layer is its ability to transmit light therethrough. The support layer should be made of a material that is transparent or translucent, or one that becomes transparent or translucent upon the application of liquid crystal material, or upon other chemical or physical treatment. The support layer in the embodiment made of absorptive material may be totally saturated with the liquid crystal material with even a possible surface excess. Alternatively, only an amount of liquid crystal material is supplied during the coating operation so that it is totally absorbed in the support layer with no surface excess (i.e. unsaturated). As an example, an opaque layer of paper or cloth can be impregnated throughout its entire thickness to become translucent or essentially transparent to the information displayed during activation of the liquid crystal layer.
[0018] The support layer is layered on one side with a base layer of material. The base layer and/or support layer is provided with information to be displayed when the liquid crystal material is activated. Specifically, information can be deposited on or formed within these layers by various techniques such as printing with inks, thermal activation for example with laser beams or other known techniques of information imprinting or impregnation. The opposite side of the support layer is layered with a cover layer of material that is at least partially transparent or translucent so that the information provided on the base layer and/or support layer is displayed upon activation of the liquid crystal material.
[0019] The layer of liquid crystal material can be coated or applied by dipping or some other technique such as spraying onto the support layer. Further, the information can be developed or provided in or on the base layer by various techniques such as by printing including screen or mask printing, gravure printing, offset printing and lithographic-type printing.
[0020] The cover layer is provided to contain the liquid crystal material stabilized by the support layer, and to also provide a protective layer for the display. Preferably, the cover layer is a clear, colorless transparent material, for example, a layer of Mylar, polyethylene and polypropylene.
[0021] The base layer can be prepared or treated such as by providing a layer of adhesive, for example contact sensitive adhesive, on its outer side to form a sticky back label.
[0022] The base layer and/or the support layer depending on the design of the information displayed are made of materials selected so as to have the proper surface properties to enable information to be deposited thereon such as during a printing process. The surface roughness, ink affinity, porosity and other physical properties are selected for depositing a marking substance with good display characteristics. Also, the selection of the printing technique in combination with specific substrate material are selected to develop a good information display. For example, colored Mylar film provides a good base layer and low weight tracing paper provides a good support layer.
[0023] The display according to the present invention should be constructed to display information in a clear manner with high resolution to be effective as a display. Further, other quality factors of the finished display must be taken into consideration including the reflectivity of the cover layer, brightness of the information displayed. These factors can all be controlled by known printing methods and proper selection of the materials forming the base, support and cover layers based on the- known properties of the materials selected.
[0024] It is important that the light shutter layer (i.e. support layer) substantially blocks out the transmittance of the display information when not activated. In order to assure essentially complete blockage, the light shutter layer must be made of sufficient and uniform thickness throughout its plane.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Referring to the drawings, wherein like reference characters refer to like parts throughout the several views, and wherein:
[0026] [0026]FIG. 1 is a sequence diagram illustrating the operation of a display made according to the present invention;
[0027] [0027]FIG. 2 is a cross-sectional view of an embodiment of the display made according to the present invention;
[0028] [0028]FIG. 3 is a cross-sectional view of another embodiment of the display made according to the present invention;
[0029] [0029]FIG. 4 is a cross-sectional view of a label made according to the present invention; and
[0030] [0030]FIG. 5 is an illustration of an assembly line for producing the label shown in FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] The present invention is concerned with liquid crystal displays. The liquid crystal displays according to the present invention can be activated through any of the various known techniques such as changing the electronic field, magnetic field, or temperature at various points, regions, or the entire field within the layer containing the liquid crystal material. Further, the liquid crystal displays according to the present invention are particularly well suited for providing displays that utilize a layer of liquid crystal to act as a thermally activated light shutter. The present invention is particularly well suited for the production of labels wherein the light shutter is activated to transmit light or information (e.g. fixed information) when the layer of liquid crystal is heated.
[0032] The liquid crystal material utilized in the present invention are of type well known in the art. Specific formulations directly applicable for use in the present invention are discussed in U.S. Pat. No. 4,028,118, incorporated herein by reference.
[0033] The layer of liquid crystal is stabilized physically and/or chemically by a support layer. The support layer can be a layer of absorptive material that can absorb and/or bind the liquid crystal material, or alternatively, can be an adhering layer that binds and/or at least partially absorbs a layer of liquid crystal material. At least one of these layers is necessary to provide a sufficient thickness of liquid crystal material in a uniform thickness throughout its plane to function as an effective light shutter. Further, the support layer provides a liquid crystal layer with good mechanical characteristics such as tensile strength and can withstand mechanical manipulation during construction of the display. Also, the support layer provides a liquid crystal layer format that is easy to handle during construction of the displays.
[0034] Depending on the type of liquid crystal and the temperature, the support layer can contain what would otherwise be a layer of liquid, which by nature is relatively difficult to contain in an article, especially during assembly of a display. The support layer is very important in the high speed production of the displays by absorbing and/or binding the liquid crystal material, of a type in a liquid or solid phase, during the assembly stages of the display.
[0035] In FIG. 1, the sequence of operation of a liquid crystal display 10 made according to the present invention is shown. During the inactivate stage (left diagram), the display does not provide any information. Upon activation of the display (right diagram), such as by heating, the liquid crystal material associated with the support layer allows the transmittance of light and information 12 (e.g. “HOT”). The light shutter is deactivated upon cooling of the display again hiding the information. The display can be cycled through the display off/on stages an indefinite number of times.
[0036] A detailed cross section of an embodiment of the display 10 according to the present invention is shown in FIG. 2. The display in this embodiment comprises a base layer 14 , a support layer 16 made of absorptive material, and a cover layer 18 . The liquid crystal material utilized in this embodiment is contained within a support layer 16 made of the absorptive material. The liquid crystal material can be applied to the absorptive material layer 16 by coating at least one side of the absorptive material layer 16 , or preferably both sides, during the method of making. The liquid crystal material may be partially absorbed into the absorptive material layer 16 , or preferably is saturated therewith. Further, the absorptive material support layer 16 may also support a thin layer of liquid crystal material on one or both sides that is not fully absorbed into this layer. In any event, the absorptive support layer material 16 substantially stabilizes what essentially is a layer of liquid crystal material, which is in the liquid phase above a specific temperature.
[0037] The absorptive material layer 16 is made of a substance that can be clear, colorless, transparent, translucent or any combination thereof to a sufficient extent so that information can be transmitted through this layer upon activation of the liquid crystal material contained therein. For example, a paper or cloth can be utilized as the absorptive material layer 16 . In order for this material to become translucent, it must be sufficiently saturated with the liquid crystal material. Alternatively, other materials, particularly fiber materials, capable of at least partially absorbing the liquid crystal material can be substituted therefore. However, these other fiber material must be transparent or translucent, or become transparent or translucent when covered or saturated with liquid crystal material (e.g. fiber glass roving or mat).
[0038] The support layer is preferably made of a material that can be made into the form of a web for the high speed production of making displays according to the present invention. Fibrous material are particularly well suited for this purpose since they can be formed into a web having sufficient tensile strength to prevent tearing and sufficient absorbency of the liquid crystal material. Papers, felts and clothes are the preferred materials for the making the support layer, since they are inexpensive, readily available in many grades and variety of specifications for different applications and purposes, and since these types of materials have the property of being opaque and becoming transparent or translucent upon absorbing liquid crystal material. Most preferred, are thin papers such as tracing paper or onion skin paper, since they become almost transparent upon absorbing liquid crystal material.
[0039] Further, the preferred support layer materials of paper, felt and cloth after being coated during an operation with hot liquid crystal material, become a wax-like solid (i.e. dry) when cooled to room temperature and provide an excellent stock material for handling purposes during the high speed production of displays, especially labels.
[0040] The information 12 is shown in FIG. 2 as being located on the lower surface of the support layer 16 . For example, the rear of the support layer 14 can be reversed printed with information in the form of indicia. Alternatively or in combination, the base layer 14 may be provided with information to be displayed.
[0041] The base layer can be made of a material that may or may not absorb the ink from a printing operation. However, in the case of a non-absorptive surface, the ink can be stabilized in or on the surface of the base layer with various known techniques such as pretreating the surface by etching. Alternatively, the base layer can be made of a material that will readily absorb and fix the ink. However, in the case of an absorptive base layer, the outer surface should be treated, coated or laminated with a layer of material to form a liquid barrier to prevent the liquid crystal material from leaching or being absorbed through the base layer 14 to the outer surface of the display.
[0042] As an alternative embodiment, the information 12 can be printed on the outside surface of a transparent or translucent base layer 14 , such as clear Mylar. Opaque material can also be used such as white or colored Mylar to enhance the visibility of the display.
[0043] Another embodiment of a display made according to the present invention is shown in FIG. 3. In this embodiment, the support layer 20 is made of adhering material. A liquid crystal layer 22 is applied to the adhering layer 20 for stabilization. The adhering layer 20 can be a fibrous material such as paper treated with a binder or adhesive having an affinity for liquid crystal, and which limits the absorbency of the fibrous material. This embodiment differs from the embodiment shown in FIG. 2, by stabilizing the liquid crystal material in a layer on the surface of the support layer 22 as opposed to stabilizing the liquid crystal material within the support layer 16 . However, the extent of absorption and formation of a separate layer depends on such factors as the type of material and the manner of forming the material into a layer. Further, this embodiment is provided with a contact adhesive layer 23 to form a sticky back label.
[0044] The ends of the display should be sealed to prevent the flow of liquid crystal material therefrom. For example, as shown in FIG. 4, the ends 24 , 26 of the cover layer 18 and base layer 14 , respectively, are sealed together by providing a clear adhesive layer 26 therebetween. This method of sealing the ends is particularly suitable for the high speed production of displays according to the present invention. This particular display arrangement is the end product of a method of making to be described below with the assembly line shown in FIG. 5.
[0045] An embodiment of a method of making a display according to the present invention is illustrated in FIG. 5. A roll 28 of stock material comprising a web 30 to form a base layer in the assembled display is supplied. For example, the stock material can be a colored or white Mylar film. A roll 32 of stock material comprising a web 34 of support material such as paper previously reverse printed, for example screen or flexo printed with indicia, on its rear surface and treated with liquid crystal material is supplied. Preferably, the printing operation is carried out prior to the liquid crystal coating operation. Further, preferably the paper web is coated on both sides with a hot liquid crystal composition. In a preferred process, the web 34 is handled at a temperature at which the liquid crystal is in a wax-like solid phase to ease handling, and prevent the flow of the liquid crystal material from the web (i.e. messing).
[0046] The side of the web 34 facing the web 30 is provided with a double sided type clear adhesive layer with a release liner for handling purposes. The remaining release liner is removed prior to bringing the webs 30 and 34 together. Alternatively, the web 30 is provided with the adhesive layer and release liner. A pair of pinching rollers 36 is provided for adhering the webs 30 , 34 together to produce a combined web 38 . The combined web 38 is fed to a die cut roller station 40 where the web 34 , only, is die cut into individual support layer sections 42 carried on the web 30 . The waste portion 44 of the web 34 is stripped from the web 30 and formed into a roll 46 .
[0047] A roll 48 comprising transparent web 50 of cover layer is supplied. The web 50 is laminated by heat and/or adhesive at the laminating station 52 to the web 30 carrying the support layer sections 42 . The resulting composite web 54 is fed to a die cutting station 56 where the web 54 is cut into individual displays 10 .
EXAMPLES
[0048] [0048] Formulation A 160 grams Stearyl Alcohol (Manufactured by C.P. Hall) 40 grams Polyethylene 9A (Manufactured by Allied Signal) 15 grams Bis-Phenol A (Manufactured by Aristech Chemical) 5 grams Crystal Violet Lactone (Manufactured by Milton Davis)
[0049] A 10-20 pound paper web is coated on both sides with formulation A. The web is blue in color below 50 degrees 25 Celsius and becomes colorless and transparent above 50 degrees Celsius. This web is used in combination with a white colored Mylar web to produce labels as shown and described with respect to FIG. 5.
EXAMPLE I
[0050] A white colored Mylar web is printed with bright orange colored ink to form the words “CAUTION HOT”. The white colored web is laminated with the above-described blue web and the blue web is laminated with a clear Mylar web from which labels according to the present invention are formed therefrom and described above.
EXAMPLE II
[0051] A white colored Mylar web is printed with the words “FOOD WARM”. The label is used to indicate the time at which food or liquid in a package becomes warm in a microwave oven.
EXAMPLE III
[0052] The crystal violet lactone in Formulation A is replaced by other dye(s) to produce virtually any color. At the transition temperature, the material becomes colorless.
EXAMPLE IV
[0053] The stearyl alcohol in formulation A is replaced by other aliphatic alcohols to vary the transition temperature of the liquid crystal web between −10 to 70 degrees Celsius. The temperature range can be expanded further by varying the polymer (e.g. polyethylene) used in formulation A.
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A liquid crystal display and method of making. The display includes a layer of support material stabilizing a layer of liquid crystal material in dimensional thickness and uniformity. The invention is particularly well suit for making heatsensitive display labels.
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FIELD OF THE INVENTION AND RELATED ART
The present invention relates to a process cartridge, and an electrophotographic image forming apparatus in which a process cartridge is removably mountable.
Here, an electrophotographic image forming apparatus is an apparatus for forming an image on a recording medium (for example, recording paper, OHP sheet, etc.), with the use of an electrophotographic image forming method. As examples of an electrophotographic image forming apparatus, there are an electrophotographic copying machine, an electrophotographic printer (for example, a laser printer, an LED printer, etc.), a facsimile machine, a word processor, a multifunction apparatus capable of performing the tasks of two or more of the preceding machines (multifunction printer, etc.), etc.
A process cartridge (which hereinafter will be referred to simply as a “cartridge”) is a cartridge which is removably mountable in the main assembly of an electrophotographic image forming apparatus, and in which a minimum of a developing means (developing member) and an electrophotographic photosensitive drum are integrally placed.
It has been a common practice to employ the combination of a developing apparatus and developer to develop an electrostatic latent image formed on an electrophotographic photosensitive drum (which hereinafter will be referred to simply as a “photosensitive drum”) of an electrophotographic image forming apparatus (which hereinafter will be referred to as an “image forming apparatus”).
An image forming apparatus which employs a process cartridge can be maintained by an operator alone. In other words, the employment of a cartridge system can drastically improve an image forming apparatus in operational efficiency.
As the technologies for making an image forming apparatus easier to use, various developer remainder detecting means capable of informing an operator of the amount of the developer remaining in the developer storage portion of a cartridge have been devised. Some of these developer remainder detecting means detect the amount of the developer remaining in the developer storage portion, by measuring the length of time a beam of light is allowed to travel through the developer storage portion of the cartridge during a predetermined length of time.
A developer remainder detecting means (which hereinafter will be referred to simply as a “remainder detecting means”) of a transmission type such as the aforementioned ones, comprises, for example: the combination of a beam emitting portion and a beam receiving portion, disposed on the main assembly side of an image forming apparatus; a beam transmitting portion with which the developer storage portion is provided; and a beam guide for guiding a beam of light emitted from the beam emitting portion, from the beam emitting portion to the beam transmitting portion, and then, to the beam receiving portion.
In the case of a developer remainder detecting means structured as described above, the length of time the detection beam is allowed to travel through the developer storage portion is dependent upon the amount of the developer remaining therein. In other words, the greater the amount of the remaining developer, the shorter the time; the smaller the amount of the remaining developer, the longer the time. Therefore, it is possible to estimate the amount of the developer remaining in the developer storage portion, by measuring the length of time the detection beam is allowed to travel through the developer storage portion, with the use of a measuring means on the main assembly side of the image forming apparatus (Japanese Laid-open Patent Application 10-186822).
As the technologies of another type for making it easier for an operator to use an image forming apparatus of a cartridge type, various methods for providing a cartridge with a storage element (storage member) have been devised. Between this storage element and the apparatus main assembly, information regarding image quality, the cartridge itself (manufacture, length of service life (for example, amount of remaining developer), the operational state of the apparatus main assembly, etc.) are exchanged, making it easier to maintain the image forming apparatus, or the cartridge (U.S. Pat. No. 5,937,239).
In recent years, demand has been increasing for an image forming apparatus which is not only easier to use, but also, smaller. In order to reduce an image forming apparatus in size, it is necessary to create a cartridge smaller in the space it occupies in the main assembly of an image forming apparatus. In the case of a color image forming apparatus, this need for cartridge size reduction is a very serious issue.
The issue of cartridge size reduction is just as important to a cartridge comprising the above-described developer remainder amount detecting means and storage element for making it easier for an operator to use a cartridge, and an image forming apparatus employing such a cartridge, as it is to a color image forming apparatus.
SUMMARY OF THE INVENTION
The primary object of the present invention is to provide a process cartridge substantially smaller than a process cartridge in accordance with the prior art, and an electrophotographic image forming apparatus in which said process cartridge is removably mountable.
Another object of the present invention is to provide a process cartridge which is substantially smaller than a process cartridge in accordance with the prior art, and in which a storage member is positioned between the point of its first light guide through which the beam of detection light enters the first light guide, and the point of its second light guide through which the beam of detection light exits from the second light guide, and an electrophotographic image forming apparatus in which the process cartridge is removably mountable.
Another object of the present invention is to provide an electrophotographic image forming apparatus, in which the beam emitting portion, beam receiving portion for receiving the detection beam emitted from the beam emitting portion, and electrical contacts on the main assembly side, are compactly disposed on the same substrate, and a process cartridge removably mountable in the electrophotographic image forming apparatus.
Another object of the present invention is to provide a process cartridge which is removably mountable in the main assembly of an electrophotographic image forming apparatus, in which the beam emitting portion, the beam receiving portion for receiving the detection beam emitted from the beam emitting portion, and electrical contacts on the main assembly side, are compactly disposed on the same substrate, comprising: an electrophotographic photosensitive drum; a developing member for developing an electrostatic latent image formed on the photosensitive drum; a frame having a developer storage portion for storing the developer used by the developing member to develop the electrostatic latent image; a first beam guide which is located at one end of the frame in terms of a direction parallel to the axial line of the electrophotographic photosensitive drum, and at the front end of the process cartridge, in terms of the direction in which the process cartridge is inserted into the main assembly of an electrophotographic image forming apparatus, and which has a beam entrance portion which is positioned directly opposite to the beam emitting portion, and through which the detection beam emitted from the beam emitting portion is guided into the developer storage portion so that the detection beam travels through the internal space of the developer storage portion, when the process cartridge is in the main assembly of the image forming apparatus; a second beam guide which is located at the same end of the frame, in terms of the direction parallel to the axial line of the electrophotographic photosensitive drum, as the end of the frame at which the first beam guide is located, and at the front end of the process cartridge, in terms of the direction in which the process cartridge is inserted into the main assembly of an electrophotographic image forming apparatus, and which has a beam exit portion which is positioned directly opposite to the beam receiving portion, and through which the detection beam having traveled through the internal space of the developer storage portion is guided toward the beam receiving portion, when the process cartridge is in the main assembly of the image forming apparatus; a storage member which is located at the same end of the frame, in terms of the direction parallel to the axial line of the electrophotographic photosensitive drum, as the end of the frame at which the first and second beam guides are located, and at the front end of the frame, in terms of the direction in which the process cartridge is inserted into the main assembly of the image forming apparatus, is enable to communicate with the main assembly of the image forming apparatus, and is located so that it is positioned between a horizontal plane coinciding with the center of the beam entrance portion, and a horizontal plane coinciding with the center of the beam exit portion, when the process cartridge is in the main assembly of the image forming apparatus. It is also an object of the present invention to provide an electrophotographic image forming apparatus in which such a process cartridge is removably mountable.
These and other objects, features, and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of the process cartridge in a preferred embodiment of the present invention.
FIG. 2 is a schematic sectional view of a color laser printer, in the preferred embodiment, which is an example of an image forming apparatus employing one of the electrophotographic processes.
FIG. 3 is a sectional view of the process cartridge, depicting the general structure thereof.
FIG. 4 is a perspective view of the process cartridge in a partially disassembled state, showing the general structure thereof.
FIG. 5 is a perspective view of the portion of the process cartridge, in the preferred embodiment, equipped with a transmission-type developer remainder amount detecting means, showing the state of the process cartridge, in which the beam of detection light has reached the beam receiving portion.
FIG. 6 is a sectional view of the portion of the process cartridge, in the first embodiment, equipped with a transmission-type developer remainder amount detecting means, showing the state of the process cartridge, in which the beam of detection light has not reached the beam receiving portion.
FIG. 7 is a perspective view of the process cartridge, in the preferred embodiment, comprising a storage means.
FIG. 8 is a perspective view of a part of the process cartridge in the preferred embodiment, showing the positioning of the light guides and storage unit.
FIG. 9 is a schematic sectional view of the process cartridge in accordance with the present invention, and its adjacencies, in an image forming apparatus, showing the state of the process cartridge in the image forming apparatus.
FIG. 10 is a view of the component of the image forming apparatus in the preferred embodiment of the present invention, having the beam emitting portion, beam receiving portion, and communicating means.
FIG. 11 is a sectional view of a cartridge showing the structure of its developer remainder amount detecting means of a transmission type.
FIG. 12 is also a sectional view of a process cartridge, showing the structure of its developer remainder amount detecting means of a transmission type.
FIG. 13 is a rear view of the process cartridge, showing the structures and positioning of the beam guides and storage means thereof.
FIG. 14 is a sectional view of the process cartridges in the preferred embodiment of the present invention, and a part of an image forming apparatus in the preferred embodiment, which are holding the process cartridges.
FIG. 15 is a perspective view of the beam emitting portion, the beam receiving portion, and communicating means, of an image forming apparatus in the preferred embodiment of the present invention.
FIG. 16 is a sectional view of the process cartridge in the preferred embodiment.
FIG. 17 shows a cartridge, illustrating arrangement of a light guide and a memory unit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, some of the preferred embodiments of the present invention will be described with reference to the appended drawings. Incidentally, the materials and shapes of the structural components, and the positional relations among them, which come up in the following descriptions of the preferred embodiment of the present invention, are not intended to limit the scope of the present invention, unless specifically noted. Further, if a component similar to a given component which came up in the description of one of the preceding embodiments comes up in the descriptions of the following embodiments, it is similar in material and shape to those in the preceding embodiments, unless specifically noted.
Referring to FIGS. 1–15 , the cartridge and image forming apparatus, in accordance with the present invention, will be described.
[General Description of Image Forming Apparatus]
First, referring to FIG. 2 , the general structure of a color image forming apparatus will be described. FIG. 2 is a schematic sectional view of a color laser printer, which is an example of an image forming apparatus, in accordance with the present invention, employing one of the electrophotographic processes.
As shown in FIG. 2 , the color laser printer 100 (which hereinafter may be referred to simply as the “printer”) has a cartridge compartment section 100 A comprising a plurality of cartridge compartments in which a yellow cartridge ( 7 Y) containing developer of yellow color (Y), a magenta cartridge ( 7 M) containing developer of magenta color (M), a cyan cartridge ( 7 C) containing developer of cyan color (C), and a black cartridge ( 7 K) containing developer of black color (K), are removably mountable, one for one. The color laser printer 100 also has an intermediary transferring member 5 , which holds a plurality of developer images different in color after the developer images developed by the cartridges 7 in the cartridge compartment section 100 A are transferred in layers onto the intermediary transferring member 5 , and from which the color images are transferred onto a recording medium P delivered from a recording medium feeding section.
The electrophotographic photosensitive drum 1 ( 1 Y, 1 M, 1 C, or 1 K, which hereinafter may be referred to simply as the “photosensitive drum”) is rotationally driven by a driving means (unshown) in the counterclockwise direction indicated by an arrow mark in FIG. 2 .
Located around the peripheral surface of the photosensitive drum 1 are a charge roller 2 , for example, charge roller 2 K as a charging member for uniformly charging the peripheral surface of the photosensitive drum 1 , and scanner units ( 3 Y, 3 M, 3 C, and 3 K) for projecting a beam of laser light, while modulating it with image formation data, in order to form an electrostatic latent image, on the peripheral surface of the photosensitive drum 1 charged by the charge roller 2 . In terms of the rotational direction of the photosensitive drum 1 , the charge roller 2 is on the upstream side of the scanner units. Also located around the peripheral surface of the photosensitive drum 1 are: a second frame 4 ( 4 Y, 4 M, 4 C, and 4 K) which holds a developing means for developing the latent image; primary transfer rollers ( 12 Y, 12 M, 12 C, and 12 K) for transferring the developer image on the peripheral surface of the photosensitive drum 1 , onto the intermediary transferring member 5 , in the primary transfer station T 1 ; and a first frame 6 ( 6 Y, 6 M, 6 C, and 6 K) holding a cleaning blade 60 for removing the developer remaining on the peripheral surface of the photosensitive drum 1 after the transfer of the developer image. The transfer rollers are on the main assembly A side of the image forming apparatus.
After being transferred onto the intermediary transferring member 5 , the developer images are transferred by a secondary transfer roller 13 onto the recording or transfer medium P, in the second transfer station T 2 . Then, the transfer medium P is conveyed through a fixing device 8 , in which the developer images on the recording medium P are fixed to the recording medium P. Then, the recording medium P is discharged by a pair of discharge rollers 25 onto the delivery tray 26 , which constitutes a part of the top surface of the apparatus main assembly.
The cartridge 7 comprises the above-described photosensitive drum 1 , the charging member 2 , the second frame 4 , and the first frame 6 . The printer 100 has a hinged cover 11 ( FIG. 6 ) to which the intermediary transferring member 5 is attached. With the cover 11 opened, the cartridge 7 is mounted into, or removed from, the printer 100 , from the photosensitive drum side thereof.
Next, referring to FIGS. 1–3 , various portions of the printer 100 and the cartridge 7 will be described.
FIG. 3 is a sectional view of the cartridge 7 , depicting the structure thereof. Here, only the cartridge 7 containing the yellow developer will be described, since all the cartridges 7 different in the color of the developers they contain are the same in structure; the cartridges 7 containing the developer different in color from yellow developer will not be described.
First, the various portions of the cartridge 7 containing the yellow developer will be described.
[Photosensitive Drum]
The photosensitive drum 1 ( 1 Y) comprises a substrate, for example, an aluminum cylinder, and a layer of organic photoconductive substance (OPC) coated on the peripheral surface of the substrate. The photosensitive drum 1 is rotatably supported at its lengthwise end portions, by a pair of supporting members, which are supported by the first frame 6 .
[Charging Member]
The charge roller 2 is a charging member based on one of the contact charging systems. It is an electrically conductive roller, to which charge bias is applied while it is placed in contact with the peripheral surface of the photosensitive drum 1 . With the application of the charge bias, the peripheral surface of the photosensitive drum 1 is uniformly charged. The charge roller 2 also is supported by the first frame 6 .
[Second Frame]
Referring to FIG. 3 , the second frame 4 ( 4 Y) has a developer storage portion 41 in which the developer of yellow color for developing the aforementioned latent image into a visible image is stored. It holds a development roller 40 as a latent image developing member, a developer conveying member 42 , a developer supplying roller 43 , and a development blade 44 . In other words, the second frame 4 supports the development roller 40 , and has the developer storage portion 41 in which the developer t used for the development of the latent image is stored. The second frame 4 is connected to the first frame 6 so that they can pivot relative to each other.
The developer in the developer storage portion 41 is sent to the developer supplying roller 43 by rotating the developer conveying member 42 in the counterclockwise direction (indicated by arrow mark X in FIG. 3 ); the developer supplying roller 43 is a member for supplying the development roller 40 with the developer. As the development roller 40 ( FIG. 3 ) is rotated in the clockwise direction (indicated by arrow Y in FIG. 3 ), the developer is coated on the peripheral surface of the development roller 40 by the supply roller 43 , and the development blade 44 is kept pressed on the peripheral surface of the development roller 40 . The supply roller 43 is an elastic roller comprising a metallic core, and a spongy layer formed around the peripheral surface of the metallic core.
As development bias is applied to the development roller 40 , a visible image, which reflects the pattern of the electrostatic latent image, is formed of the developer, on the peripheral surface of the photosensitive drum 1 . In other words, the development roller 40 develops the electrostatic latent image formed on the peripheral surface of the photosensitive drum 1 .
Next, the various portions of the main assembly A of the image forming apparatus will be described.
[Exposing Means]
The scanner unit as an exposing means comprises a laser diode (unshown), to which image formation signals are given. As the image formation signals are given to the laser diode, the laser diode emits a beam of image formation light which reflects the image formation signals, onto one of the polygon mirrors ( 9 Y, 9 M, 9 C, and 9 K), which are being rotated at a high velocity by a scanner motor (unshown). As a result, the beam of image formation light is deflected by one of the mirrors ( 9 Y, 9 M, 9 C, and 9 K) toward a focal lens (unshown), and is transmitted through the focal lens, being thereby focused on the peripheral surface of the photosensitive drum 1 , which is being rotated at a predetermined constant peripheral velocity. As a result, the numerous points of the peripheral surface of the photosensitive drum 1 are selectively exposed, forming thereby an electrostatic latent image, on the peripheral surface of the photosensitive drum 1 .
[Intermediary Transferring Member]
The intermediary transferring member 5 is a member onto which a plurality of images formed of the developer, on the peripheral surfaces of the photosensitive drums 1 , by the development rollers 40 , one for one, are transferred in layers during the color image formation process. The intermediary transferring member 5 is circularly rotated in the clockwise direction ( FIG. 2 ) at the same peripheral velocity as those of the photosensitive drums 1 .
The images formed of the developer (which hereinafter will be referred to as the developer image), on the photosensitive drums 1 , are transferred in layers onto the intermediary transferring member 5 , in the primary transfer stations T 1 , by the primary transfer rollers ( 12 Y, 12 M, 12 C, and 12 K) which are kept pressed against the peripheral surfaces of the photosensitive drums 1 , with the intermediary transferring member 5 kept pinched between the transfer rollers and photosensitive drums 1 , and to which voltage is being applied. The primary transfer stations T 1 are where the peripheral surfaces of the primary transfer rollers are kept pressed against the peripheral surface of the photosensitive drums 1 , with the intermediary transferring member 5 kept pinched between the two surfaces.
After the multilayer transfer of the developer images, the intermediary transferring member 5 is moved through the secondary transfer station T 2 , through which the recording medium P is conveyed while remaining pinched between the secondary transfer roller 13 to which voltage is being applied, and the intermediary transferring member 5 , so that the developer images on the intermediary transferring member 5 are transferred all at once onto the recording medium P.
The intermediary transferring member 5 in accordance with the present invention is an endless and seamless belt formed of resin. It is stretched around a driving roller 14 , a counter roller 15 , and a tension roller 16 , being thereby supported by the three rollers.
Further, the intermediary transferring member 5 is attached to the apparatus main assembly A at the driving roller 14 . As the driving force is transmitted to one of the lengthwise ends of the driving roller 14 from a motor (unshown) in coordination with an image forming operation, the driving roller 14 is rotated in the clockwise direction indicated in the drawing.
[Sheet Conveying Portion]
The sheet conveying portion is a portion for conveying a recording medium P to the photosensitive drum 1 . It comprises a cassette 17 storing multiple recording media P, a feed roller 18 , a separation pad 19 , and a pair of registration rollers 21 .
During an image forming operation, the roller 18 is rotationally driven in synchronism with the image forming operation, feeding the recording media P in the cassette 17 , out into the apparatus main assembly A, one by one. Each recording medium P is conveyed to the pair of registration rollers 21 by way of the sheet conveying rollers (unshown). The pair of registration rollers 21 carries out a non-rotational operation which keeps the recording medium P on standby, and a rotational operation which releases the recording medium P toward the intermediary transferring member 5 , following a predetermined sequence, in order to align the developer images with the recording medium P, for the transfer process.
[Transfer Station]
The transfer station comprises the secondary transfer roller 13 , which is movable roughly in the vertical direction; it is moved by a cam (unshown), with the timing for transferring the developer images, to the top position in which it transfers the developer images onto the recording medium P, that is, the position in which it is kept pressed against the intermediary transferring member 5 , with the recording medium P kept pinched between the transfer roller 13 and intermediary transferring member 5 . While the transfer roller 13 is kept pressed against the intermediary transferring member 5 , bias is continuously applied to the transfer roller 13 . As a result, the developer images on the intermediary transferring member 5 are transferred onto the recording medium P.
The intermediary transferring member 5 and the transfer roller 13 are individually driven. Therefore, the recording medium P is conveyed in the leftward direction, in FIG. 2 , at a predetermined speed, while remaining pinched between the intermediary transferring member 5 and transfer roller 13 . Then, the recording medium P is further conveyed by the conveyer belt 22 toward the fixation station.
[Fixation Station]
The fixing device 8 fixes the developer images which have just been transferred onto the recording medium P from the intermediary transferring member 5 . To describe in more detail, the fixing device 8 comprises: a film guide unit 23 containing a ceramic heater for heating the recording medium P, and a pressure roller 24 for keeping the recording medium P pressed against the film guide unit 23 . In other words, heat and pressure are applied to the recording medium P bearing the developer images, while the recording medium P is conveyed by the film guide unit 23 and the pressure roller 24 . As a result, the developer images on the recording medium P are fixed to the recording medium P.
[Image Forming Operation]
Next, the image forming operation carried out by the apparatus structured as described above will be described.
First, the roller 18 ( FIG. 2 ) is rotated to separate one of the recording media P in the cassette 17 from the rest, and conveys it to the pair of registration rollers 21 .
Meanwhile, the photosensitive drum 1 and the intermediary transferring member 5 are rotated at a predetermined peripheral velocity (which hereinafter may be referred to as process speed) in the direction indicated by an arrow mark in FIG. 2 .
After the peripheral surface of the photosensitive drum 1 is uniformly charged by the charge roller 2 , it is exposed to the aforementioned beam of exposure light. As a result, a latent image is formed on the peripheral surface of the photosensitive drum 1 . Since all the cartridges are the same in terms of their image forming operation, only the operation for forming an image of yellow color will be described, here.
[Formation of Yellow Image]
An electrostatic image which reflects the yellow component of an intended color image is formed on the peripheral surface of the photosensitive drum 1 Y, by projecting a beam of laser light emitted from the scanner unit 3 Y which corresponds to the yellow component of the intended image. In synchronism with the formation of the latent image, the developing means held in the second frame 4 Y is made to operate to adhere the yellow developer to the peripheral surface of the photosensitive drum 1 , in the pattern of the latent image; the developing means is operated to develop the latent image. The developer image formed on the peripheral surface of the photosensitive drum 1 Y is transferred onto the outwardly facing surface of the intermediary transferring member 5 , by applying to the intermediary transferring member 5 , a voltage opposite in polarity to the yellow developer, in the transfer station T 1 located on the downstream side of the development station.
Next, the latent images reflecting the magenta, cyan, and black components of the intended color image, are formed and are developed into the magenta, cyan, and black developer images, in the mentioned order. Then, the magenta, cyan, and, black developer images are sequentially transferred onto the intermediary transferring member 5 . As a result, a full color image is formed of four developer images, that is, the yellow, magenta, cyan, and black developer images, on the intermediary transferring member 5 .
Before the leading edge of the full-color image formed on the intermediary transferring member 5 reaches the secondary transfer station T 2 , the recording medium P kept on standby by the aforementioned pair of registration rollers 21 is released so that the leading end of the recording medium P will arrive at the secondary transfer station T 2 at the same time as the leading edge of the full-color image.
The transfer roller 13 kept on standby below the counter roller 15 , that is, in the aforementioned bottom position, while the aforementioned four developer images different in color are formed, is moved upward into the aforementioned top position by the cam (unshown), pressing thereby the recording medium P upon the intermediary transferring member 5 , in the transfer station T 2 . Then, a bias opposite in polarity from the developer is applied to the transfer roller 13 . As a result, the four developer images, which make up the single full-color image, are transferred all at once onto the recording medium P.
After being conveyed through the transfer station T 2 , the recording medium P is conveyed to the fixing apparatus 8 , in which the developer images are fixed. Thereafter, the recording medium P is discharged by the pair of discharge rollers 25 onto the delivery tray 26 on top of the apparatus main assembly A, concluding the printing of a single copy.
[Process Cartridge Structure]
Next, referring to FIGS. 3–5 , the structure of the cartridge 7 will be described. FIG. 3 is a sectional view of the essential portion of the cartridge 7 containing the developer t, and FIG. 4 is a perspective view of the cartridge 7 . In FIG. 4 , the second and first frames 4 and 6 are separated from each other. FIG. 5 is a perspective view of the cartridge 7 , as seen from the opposite side from the photosensitive drum 1 . More specifically, FIG. 5 is a perspective view of the lengthwise ends of the frames 4 and 6 , on their front sides in terms of the direction in which the cartridge 7 is inserted into the apparatus main assembly A.
Referring to FIG. 3 , the housing of the cartridge 7 comprises the first frame 6 and second frame 4 , which can be separated from each other. The first frame 6 holds the electrophotographic photosensitive drum 1 , that is, an electrophotographic photosensitive member in the form of a drum, the charge roller 2 , and the cleaning blade 60 , whereas the second frame 4 holds the development roller 40 for developing an electrostatic latent image on the photosensitive drum 1 .
To the first frame 6 , the photosensitive drum 1 is rotatably attached, with a pair of bearings 31 (cartridge positioning members) placed between the photosensitive drum 1 and the first frame 6 . Around the peripheral surface of the photosensitive drum 1 , the charge roller 2 for uniformly charging the peripheral surface of the photosensitive drum 1 , and the cleaning blade 60 for removing the developer remaining on the peripheral surface of the photosensitive drum 1 , are placed in contact with the peripheral surface of the photosensitive drum 1 .
As the developer remaining on the peripheral surface of the photosensitive drum 1 is cleaned by the cleaning blade 60 , it is conveyed by the developer conveying mechanism 62 to a waste developer chamber 63 located in the rear portion of the drum unit frame 61 . To the helical gear 46 located at the other lengthwise end of the second frame 4 , the driving force of a motor (unshown) is transmitted. In other words, the helical gear 46 is the gear which receives from the apparatus main assembly A the force for rotating the development roller 40 , the developer supplying roller 43 , and the developer conveying member 42 , while the cartridge 7 is in the apparatus main assembly A. Also, the photosensitive drum 1 is rotationally driven (in counterclockwise direction) in synchronism with an image forming operation, by the force transmitted from the apparatus main assembly A. The lengthwise end portions of the axle of the photosensitive drum 1 are fitted with the aforementioned pair of bearings 31 , and in order to precisely position the cartridge 7 relative to the image forming apparatus main assembly A, the cartridge 7 is positioned relative to the side plates 106 of the image forming apparatus main assembly A, with the pair of bearings 31 positioned between the side plates 106 , and lengthwise ends of the axle of the photosensitive drum 1 , one for one.
The second frame 4 holds the development roller 40 , which is rotated (in the direction indicated by arrow Y) in contact with the photosensitive drum 1 . It also has the developer storage portion 41 which contains the developer. Further, it has a developing means container 45 . The development roller 40 is rotatably supported by the developing means container 45 , with the development roller bearings 47 and 48 placed between the development roller 40 and the developing means container 45 . In the adjacencies of the peripheral surface of the development roller 40 , the developer supplying roller 43 , which is rotated (in the direction indicated by arrow mark Z) while being pressed against the development roller 40 , and development blade 44 , are located. Further, within the developer storage portion 41 , the developer conveying mechanism 42 for conveying the developer, while stirring it, to the developer supplying roller 43 is provided.
Next, referring to FIG. 4 , the second frame 4 is attached to the first frame 6 in such a manner that it can be pivoted about the pair of pins 49 a fitted in the hole 49 of the development roller bearing 47 and the hole 49 of the development roller bearing 48 , one for one.
When the cartridge 7 is not in the apparatus main assembly A, the second frame 4 is kept constantly pressed by a pair of compression springs 64 in the direction to be rotated about the pair of pins 49 a so that the development roller 40 is kept pressured toward the photosensitive drum 1 by the moment generated by the pair of compression springs 64 .
During development, the developer in the developer storage portion 41 is conveyed by the developer stirring member 42 to the developer supplying roller 43 , which is being rotated (in the direction indicated by arrow mark Z) while rubbing against the development roller 40 which is also being rotated (in the direction indicated by arrow mark Y). As a result, the developer is supplied to the peripheral surface of the development roller 40 , being thereby borne on the peripheral surface of the development roller 40 . Then, the developer borne on the peripheral surface of the development roller 40 is delivered by the rotation of the development roller 40 to the development blade 44 , which forms the body of developer on the peripheral surface of the development roller 40 into a thin layer of the developer with a predetermined thickness, while charging the developer. Then, the thin layer of the developer is delivered by the rotation of the development roller 40 to the development station, in which the peripheral surface of the photosensitive drum 1 is in contact with the peripheral surface of the development roller 40 , and development bias (DC voltage) is applied to the development roller 40 from the power source (unshown) of the image forming apparatus 100 by way of a development power supply contact 92 , so that the developer particles in the thin layer of the developer are adhered to the peripheral surface of the photosensitive drum 1 , in the pattern of the electrostatic latent image on the peripheral surface of the photosensitive drum 1 , developing thereby the latent image into a visible image.
The developer which did not contribute to the development, that is, the developer remaining on the peripheral surface of the development roller 40 , is returned by the rotation of the development roller 40 to the developing means container 45 , in which the developer is stripped (it is recovered) from the peripheral surface of the development roller 40 by the developer supplying roller 43 which is being rotated while rubbing the development roller 40 . The recovered developer is stirred and mixed with the developer in the developing means container 45 , by the developer stirring mechanism 42 .
The cartridge 7 is provided with a charge bias electrical contact 91 for supplying the charge roller 2 with high voltage from the power source (unshown) on the main assembly side, a development bias electrical contact 92 for supplying the development roller 40 and the developer supplying roller 43 with high voltage from the power source (unshown) on the main assembly side, and a blade bias electrical contact 93 for supplying the development blade 44 with high voltage. These electrical contacts 91 , 92 , and 93 are attached to one of the lengthwise end walls, that is, the walls perpendicular to the direction parallel to the axial direction of the photosensitive drum 1 . More specifically, the charge bias electrical contact 91 is attached to one of the lengthwise end walls (in terms of the direction parallel to the aforementioned axial line) of the first frame 6 supporting the charge roller 2 .
The electrical contact 92 for supplying the development roller and the developer supplying roller with bias, and the blade bias electrical contact 93 , are attached to one of the lengthwise end walls (in terms of the direction parallel to the aforementioned axial line) of the second frame 4 supporting the development roller 40 , the developer supplying roller 43 , and the development blade 44 . In other words, the electrical contacts 91 , 92 , and 93 are attached to the lengthwise end walls 4 a and 6 a of the second and first frames 4 and 6 , respectively, in terms of the lengthwise direction of the frames, being exposed from the end walls 4 a and 6 a , which are on the same end of the cartridge 7 in terms of the lengthwise direction of the cartridge 7 .
As the cartridge 7 is inserted into the apparatus main assembly A, these electrical contacts 91 , 92 , and 93 come into contact with the charge bias electrical contacts (for example, 111 Y, and 111 K), the development bias electrical contacts (for example, 112 Y, and 112 K), and the blade bias electrical contacts (for example, 113 Y, and 113 K) of the apparatus main assembly A, being thereby enabled to supply the corresponding components of the cartridge 7 with electric power. The electrical contacts 91 , 92 , and 93 are electrically connected to the corresponding components in the cartridge 7 , and so are the electrical contacts 111 Y, 111 K, 112 Y, 112 K, 113 Y, and 113 K of the apparatus main assembly A.
More specifically, the first frame 6 holds the charge roller 2 for charging the photosensitive drum 1 . The end wall 6 a of the first frame 6 , located at one of the lengthwise ends of the first frame 6 in terms of the direction parallel to the axial direction of the photosensitive drum 1 , is provided with the charge bias electrical contact 91 , through which voltage is supplied to the charge roller 2 from the apparatus main assembly A when the cartridge 7 is in the apparatus main assembly A.
The second frame 4 holds the development roller 40 as a latent image developing member, the development blade 44 for regulating the amount of the developer to be kept adhered to the peripheral surface of the development roller 40 , and the developer supplying roller 43 for supplying the peripheral surface of the development roller 40 with the developer. The lengthwise end wall 4 a of the second frame 4 , located at one of the lengthwise ends of the second frame 6 in terms of the direction parallel to the axial line of the electrophotographic photosensitive drum, is provided with the blade bias electrical contact 92 for supplying the development blade 44 with voltage from the image forming apparatus main assembly A when the cartridge 7 is in the apparatus main assembly A. The end wall 4 a of the second frame 4 is also provided with the development bias electrical contact 92 (developer supplying bias electrical contact) through which the development voltage, and the voltage for the developer supplying roller 43 , are supplied to the development roller 40 and the developer supplying roller 43 , from the image forming apparatus main assembly A, when the cartridge 7 is in the image forming apparatus main assembly A.
With the employment of the above-described structural arrangement, all the electrical contacts of the cartridge 7 are placed at one of the lengthwise ends of the cartridge 7 , making it possible to place all the electrical contacts of the apparatus main assembly A on the same end of the apparatus main assembly A. In other words, the electrical junction of the apparatus main assembly A can be placed at one end of the electrical circuit board of the apparatus main assembly A.
[Cartridge Supporting Structure of Image Forming Apparatus]
Next, referring to FIGS. 6–10 , the cartridge supporting structure of the image forming apparatus 100 will be described. FIG. 6 is a sectional view of the image forming apparatus, the hinged cover 11 of which is open, and FIG. 7 is a perspective view of the same image forming apparatus. FIG. 8 is a perspective view of the cartridge supporting portion (plate) of the image forming apparatus, depicting the structure thereof, and FIG. 9 is a drawing for depicting the structure of the cartridge positioning portion of the image forming apparatus main assembly A for positioning the cartridge 7 as the cartridge 7 is inserted into one of the cartridge compartments of the apparatus main assembly A. FIG. 10 is a drawing for depicting the cartridge 7 in the apparatus main assembly A after the precise positioning of the cartridge 7 in the apparatus main assembly A by closing the hinged cover 11 . Incidentally, FIGS. 9 and 10 show the cartridge in the top cartridge compartment of the image forming apparatus main assembly A; the other cartridge compartments of the image forming apparatus main assembly A, that is, the cartridge compartments for the cartridges 7 for the colors different from the one shown in FIGS. 9 and 10 , which are the same in structure as the cartridge compartment shown in FIGS. 9 and 10 , are not shown.
The rotational axis of the hinged cover 11 is located in the bottom portion of the image forming apparatus 100 . To the hinged cover 11 , the aforementioned intermediary transferring member 5 is attached. Therefore, opening the hinged cover 11 makes it possible for an operator to access the cartridges 7 Y, 7 M, 7 C, and 7 K. What is holding the cartridges 7 Y, 7 M, 7 C, and 7 K is a cartridge holding member 101 , the rotational axis 101 a–b of which, that is, the axis of the cartridge holding member supporting member, is located in the top portion of the apparatus main assembly A.
The cartridge holding member 101 is connected to the hinged cover 11 by a linkage (unshown). Thus, opening the hinged cover 11 makes the cartridge holding member 101 rotate (roughly 45 degrees in this embodiment) about the pivot 101 a–b , thereby causing the cartridges 7 in the cartridge holding member 11 to orbitally move through a predetermined angle (roughly 40 degrees in this embodiment) about the pivot 101 a–b . In other words, opening the hinged cover 11 makes it easier to insert the cartridges 7 into the apparatus main assembly A, or remove them therefrom.
In this embodiment, for cost reduction, the left- and right-hand portions ( 101 a and 101 b ) of the cartridge holding member 101 are separately formed, and then, are joined. However, the cartridge holding member 101 may be formed as a single-piece member. When the left- and right-hand portions are separately formed, the two portions are solidly held together by a linking member. Therefore, the two-piece cartridge holding member 101 is virtually the same in structure as a single-piece cartridge holding member 101 .
Referring to FIG. 8 , the portion 101 b of the cartridge holding member 101 is provided with four sets of the charge bias electrical contacts, development bias-development supply bias electrical contacts, and development blade bias electrical contacts, one set for each of the four cartridge compartments, as the electrical contacts for supplying the cartridges 7 with the aforementioned high voltages. Thus, as the cartridge 7 is inserted into the cartridge holding member 101 in the direction indicated by an arrow mark in the drawing, the aforementioned charge bias electrical contact 91 , development bias-developer supplying bias electrical contact 92 , and blade bias electrical contact 93 of the cartridge 7 come into contact with the charge bias, development bias-development supply bias, and development blade bias electrical contacts of the portion 101 b of the cartridge holding member 101 , respectively. Incidentally, the direction in which the cartridge 7 is inserted into the image forming apparatus 100 is the direction perpendicular to the lengthwise direction (axial direction) of the photosensitive drum 1 .
Next, the cartridge 7 and the cartridge holding member 101 will be described regarding their structures for making the closing of the hinged cover 11 precisely position the cartridge 7 relative to the cartridge holding member 101 .
After the cartridge holding member 101 is rotated outward roughly 45 degrees from the position in which it is kept when forming an image, the cartridge 7 can be effortlessly inserted into the apparatus main assembly A.
Referring to FIG. 9 , as the cartridge 7 is inserted into the first position, which is the deepest position for the cartridge 7 in the cartridge holding member 101 , the cartridge regulating portion 81 of the cartridge 7 comes into contact with the cartridge regulating portion 101 a–f of the apparatus main assembly A, which is a part of the cartridge holding portion 101 .
Next, the hinged cover 11 is to be closed. As the hinged cover 11 is closed, the cartridge holding member 101 is moved into the image forming apparatus main assembly A by the linkage connected to the hinged cover 11 and cartridge holding member 101 , causing the cartridge 7 to move into the second position, as shown in FIG. 10 , in which the cartridge 7 can be used for image formation. As the cartridge 7 is moved into the second position, the drum shaft bearings 31 (first and second cartridge positioning portions) fitted around the lengthwise end portions of the photosensitive drum 1 and projecting outward from the lengthwise ends of the first frame 6 in the axial direction of the photosensitive drum 1 , fit into the positioning portions 106 a (first and second positioning portions), one for one, of the side plates 106 of the image forming apparatus main assembly A, and each of the bearings 31 is pressed against the two surfaces 106 a 1 and 106 a 2 of the side plate 106 , on the corresponding side, facing rearward, in terms of the cartridge insertion direction, and upward, respectively.
Also as the cartridge 7 is moved into the second position in the apparatus main assembly A, the cartridge regulating portion 81 of the cartridge 7 comes into contact with the cartridge regulating portion 101 a–f of the apparatus main assembly A.
In other words, the cartridge 7 is provided with a first cartridge positioning portion comprising the bearing 31 , which is located at one of the lengthwise ends of the first frame 6 , and which comes into contact with a first cartridge positioning portion comprising the positioning portion 106 a of the image forming apparatus main assembly A to precisely position the cartridge 7 relative to the apparatus main assembly A when the cartridge 7 is inserted into the image forming apparatus main assembly A. The cartridge 7 is also provided with a second cartridge positioning portion comprising another bearing 31 , which is located at the other lengthwise end of the first frame 6 , and which comes into contact with a second cartridge positioning portion comprising another positioning portion 106 a of the image forming apparatus main assembly A in order to precisely position the cartridge 7 relative to the image forming apparatus main assembly A as the cartridge 7 is inserted into the image forming apparatus main assembly A. Further, the cartridge 7 is provided with the cartridge regulating portion 81 , which is a part of the first frame 6 , and which comes into contact with the cartridge regulating portion 101 a–f of the image forming apparatus main assembly A, thereby regulating the rotation of the cartridge 7 about the first and second cartridge positioning portions 31 of the cartridge 7 , when the cartridge 7 receives the driving force transmitted from the image forming apparatus main assembly A.
Next, the reception, by the cartridge 7 , of the diving force transmitted from the image forming apparatus 100 will be described.
The cartridge 7 is provided with a driving force receiving portion 30 (coupler) connected to one of the lengthwise ends of the supporting shaft of the photosensitive drum 1 . As the driving force receiving portion 30 is engaged with the driving force transmitting means (unshown) of the apparatus main assembly A, the driving force is transmitted to the photosensitive drum 1 , thereby rotating the photosensitive drum 1 in the clockwise direction ( FIG. 10 ). As the photosensitive drum 1 receives the driving force, the first frame 6 is subjected to such a moment that acts in the direction to rotate the first frame 6 in the direction indicated by the arrow mark, about the line which coincides with the axial lines of the pair of bearings 31 as the first and second cartridge positioning portions. As a result, the first frame 6 is rotated in the direction indicated by the arrow mark, thereby causing the cartridge regulating portion 81 as the third cartridge positioning portion to come into contact with the cartridge regulating portion 101 a–f of the apparatus main assembly A. The contact between the cartridge regulating portion 81 and the cartridge regulating portion 101 a–f caused by the moment fixes the attitude of the cartridge 7 in terms of the direction in which the cartridge 7 is pivoted by the moment generated as the photosensitive drum 1 is rotationally driven by the driving force from the apparatus main assembly A. As a result, the cartridge 7 , in particular, the photosensitive drum 1 in the cartridge 7 , is precisely positioned relative to the apparatus main assembly A.
[Structure of Stirring Member, and Detection of Developer Remainder Amount by Beam Transmission]
Next, referring to FIGS. 11 and 12 , the detection of the developer remainder amount by beam transmission will be described. FIG. 11 is a sectional view of the cartridge 7 , in accordance with the present invention, equipped with a transmission-type developer remainder amount detecting means, in which the beam of detection light has reached the beam receiving portion, and FIG. 12 is a sectional view of the transmission-type developer remainder amount detecting means, in which the beam of detection light has not reached the beam receiving portion.
Referring to FIG. 11 , within the developer storage portion 41 , a developer stirring member 42 is positioned. The rotation of the developer stirring member 42 in the direction indicated by the arrow mark X conveys the developer to the developer supplying roller 43 . The stirring member 42 comprises a shaft 42 a , and a flexible sheet 42 b for conveying the developer while stirring it.
The force for driving the stirring member 42 is transmitted thereto by a driving gear (unshown) inserted through the hole in one of the side walls of the developer storage portion 41 .
The developer storage portion 41 is provided with first and second beam guides 51 and 52 , each of which is the integral combination of a transparent window and a beam guiding portion. The first light guide 51 is on the side from which the beam of detection light enters. The first and second light guide 51 and 52 are near the aforementioned end walls 4 a and 6 a ( FIG. 5 ), respectively, in terms of the lengthwise direction of the cartridge 7 . The first light guide 51 is for guiding the beam L of the developer remainder amount detection light emitted from a beam emitting portion 53 (LED) located in the image forming apparatus main assembly A, into the developer storage portion 41 . After passing through the developer storage portion 41 , the detection beam L is guided by the second beam guide to the beam receiving portion 54 (photo-transistor) located also in the image forming apparatus main assembly A. As the aforementioned flexible sheet 42 b of the developer stirring member 42 is rotated, not only does it interrupt the detection beam L, but also cleans the inward surface 51 b of the first light guide 51 , and the inward surface 52 b of the second light guide 52 .
In this embodiment, incidentally, the outward surface 52 a of the second light guide 52 , from which the detection beam L exits, is located a predetermined distance forward, in terms of the direction in which the cartridge 7 is inserted into the image forming apparatus main assembly A (leftward in FIGS. 11 and 12 ), relative to the outward surface 51 a of the first light guide 51 , from which the detection beam L is guided into the developer storage portion 41 .
FIG. 11 shows the state of the cartridge 7 immediately after the cleaning of the beam transmission surface 51 b of the first light guide 51 by the flexible sheet 42 b . The amount of the developer remainder in the developer storage portion 41 shown in FIG. 11 is relatively small. Thus, the detection beam L is allowed to uninterruptedly travel through the developer storage portion 41 to be transmitted through the second light guide 52 , and is detected by the beam receiving portion 54 . In comparison, FIG. 12 shows the state of the cartridge 7 immediately before the flexible sheet 42 b begins to clean the detection beam transmission surface 51 b . When the cartridge 7 is in the state shown in FIG. 12 , the detection beam L is blocked by the developer stirring member 42 as well as the developer in the developer storage portion 41 , being therefore prevented from reaching the second beam guide 52 ; in other words, the detection beam L is not detected by the beam receiving portion 54 located in the image forming apparatus main assembly A.
When the cartridge 7 is structured as described above, it is possible to detect the length of time the detection beam L is allowed to freely travel through the developer storage portion 41 per rotation of the stirring member 42 . This length of time is processed by the control portion of the apparatus main assembly A following a predetermined procedure in order to estimate the amount of the remaining developer remaining in the developer storage portion 41 . With the employment of this procedure, the amount of the remaining developer remaining in the developer storage portion 41 can be reasonably precisely estimated when the amount of the developer remaining in the developer storage portion 41 is in the range of 0%–25% of the effective developer capacity of the developer storage portion 41 .
To summarize, the second frame 4 of the cartridge 7 is provided with the first and second beam guides 51 and 52 , which are located near one of the lengthwise ends in terms of the direction parallel to the axial line of the photosensitive drum 1 , and at the front end in terms of the direction in which the cartridge 7 is mounted. The first beam guide 51 is positioned so that when the cartridge 7 is in the apparatus main assembly A, the beam entrance surface 51 a of the first beam guide 51 directly faces the aforementioned beam emitting portion 53 located in the apparatus main assembly A, and the second beam guide 52 is positioned so that when the cartridge 7 is in the apparatus main assembly A, the beam exit surface 52 a of the second beam guide 52 directly faces the aforementioned beam receiving portion 54 .
Further, when the cartridge 7 is in the apparatus main assembly A, the first frame 6 is located on top of the second frame 4 , and the first beam guide 51 is located under the developer storage portion 41 , guiding the detection beam L emitted from the beam emitting portion 53 , into the developer storage portion 41 ; the detection beam L enters the first beam guide 51 and is transmitted into the developer storage portion 41 through the detection beam guide 51 , whereas the second beam guide 52 is located on top of the developer storage portion 41 , guiding the detection beam L to the beam receiving portion 54 after the detection beam L travels through the developer storage portion 41 ; the detection beam L exits from the beam exit surface 52 a and reaches the beam receiving portion 54 . Incidentally, “at one of the lengthwise ends” means “nearer to one of the lengthwise ends than to the center of the second frame in terms of the direction parallel to the axial direction of the photosensitive drum 1 ”.
Structuring the cartridge 7 as described above makes it possible to avoid positioning the beam emitting portion 53 so that it overlaps with the photosensitive drum 1 in terms of the direction perpendicular to the axial line of the photosensitive drum 1 . Therefore, it prevents the photosensitive drum 1 from being exposed to the detection beam L, raising thereby the level of image quality at which an image is formed.
As seen from the direction parallel to the axial line of the photosensitive drum 1 held by the second frame 4 , the second beam guide 52 is located forward of the first beam guide 51 in terms of the direction in which the cartridge 7 is inserted into the apparatus main assembly A; the beam exit surface 52 a is forward of the beam entrance surface 51 a.
[Structure of Storage Means of Process Cartridge]
Next, referring to FIGS. 1 and 13 , the storage means of the cartridge 7 will be described regarding the structure of and communication with the image forming apparatus main assembly A. FIG. 13 is a rear view of the cartridge 7 having a storage means, in accordance with the present invention.
The storage means 55 (which hereinafter may be referred to as a memory unit) is located at the front end of the cartridge 7 in terms of the cartridge insertion direction. The memory unit 55 comprises a memory 55 b , first and second electrical contacts 55 d 1 and 55 d 2 as electrical contacts on the cartridge side, a pair of conductive areas 55 c 1 and 55 c 2 , and a dielectric substrate 55 a , on which the preceding portions are placed. The first and second contacts 55 d 1 and 55 d 2 are within the conductive areas 55 c 1 and 55 c 2 , respectively, which are positioned in a manner to sandwich the memory 55 b from the left and right sides, respectively.
The cartridge 7 is provided with an electrical contact, which is located at one end of the first frame 6 in terms of the direction parallel to the axial direction of the photosensitive drum 1 , and at the front end of the cartridge 7 in terms of the cartridge mounting direction, and which comes into contact with the electrical contact 56 a of the image forming apparatus main assembly A, thereby transmitting the data stored in the memory 55 b to the image forming apparatus main assembly A, as the cartridge 7 is mounted into the image forming apparatus main assembly A.
The memory 55 b , the first conductive area 55 c 1 having the first electrical contact 55 d 1 as the electrical contact on the cartridge side, and the second conductive area 55 c 2 having the second electrical contact 55 d 2 as the electrical contact on the cartridge side, are on the same substrate 55 a . Listing from the inward side of the cartridge 7 in terms of the aforementioned direction parallel to the axial line of the photosensitive drum 1 , the first conductive area 55 c 1 , the memory 55 b , and the second conductive area 55 c 2 are disposed on the substrate 55 a . Further, the straight line S 1 ( FIG. 13 ) connecting the outward edge of the beam entrance portion (surface) 51 a in terms of the direction parallel to the axial line of the photosensitive drum 1 held by the second frame 4 , and the outward edge of the beam exit portion (surface) 52 a , overlaps with at least a part of the substrate 55 a , as seen from the direction perpendicular to the drawing. In this embodiment, the straight line S 1 crosses the first conductive area 55 c 1 , which is on the inward side of the memory 55 b in terms of the direction parallel to the axial line of the photosensitive drum 1 .
Structuring the cartridge 7 as described above makes it possible to utilize the space between the first and second beam guides, which otherwise is a dead space. In particular, it makes it possible to reduce the dimension of the cartridge 7 in terms of the direction parallel to the axial line of the photosensitive drum 1 .
Referring to FIG. 13 , in this embodiment, the cartridge 7 is provided with two first electrical contacts 55 d 1 , which are located in the first conductive area 55 c 1 , and two second electrical contacts 55 d 2 , which are located in the second conductive area 55 c 2 , improving the cartridge 7 in reliability of electrical connection. The image forming apparatus main assembly A is provided with a communication unit 56 (shown in FIG. 14 ) as a communicating means connected to the controller (unshown). As the cartridge 7 is inserted into the apparatus main assembly A, the electrical contacts 55 d 1 and 55 d 2 of the memory unit 55 , within the first and second conductive areas 55 c 1 and 55 c 2 , respectively, come into contact with the communication contacts 56 a (electrical contacts on the main assembly side shown in FIG. 15 ), making possible the communication between the memory 55 b of the memory unit 55 , and a controller of the apparatus main assembly A (making it possible to read data in memory 55 b , or write data into memory 55 b ).
The data to be stored in the memory 55 b are one or more of various parameters showing the state of the cartridge 7 , for example, the types of the electrophotographic photosensitive drum 1 and the developer t in the cartridge 7 , the lot number, the history of cartridge usage, the number of performed image forming operations, etc.
Another datum stored in the memory 55 b is datum regarding the amount of the developer remaining in the developer storage portion 41 , which is transmitted from the apparatus main assembly A through the electrical contacts 55 d 1 and 55 d 2 on the cartridge side. In this embodiment, a minimum of the datum regarding the amount of the remaining developer detected by the developer remainder amount detecting means is stored in the memory 55 b . Having the data regarding the amount of the remaining developer stored in the memory 55 b makes it possible to properly manage a cartridge 7 in terms of service life, even when the cartridge 7 is transferred from one apparatus to another during its usage.
The memory unit 55 is attached to the first frame 6 with the use of one of such means as a piece of two-sided adhesive tape, adhesive, thermal crimping, ultrasonic welding, snap fit, etc., and is precisely positioned relative to the apparatus main assembly A by the first and second cartridge positioning portions 31 (bearings) of the first frame of the cartridge 7 . Therefore, the memory unit 55 attached to the first frame 6 is precisely positioned relative to the apparatus main assembly A, being thereby precisely positioned relative to the communication unit 56 of the apparatus main assembly A.
The communication unit 56 is provided with four sets of conductive electrical contacts 56 a . Each set has two electrical contacts 56 a , which are placed in contact with the two conductive areas 55 c 1 and 55 c 2 of the corresponding memory unit 55 .
Providing each of the conductive areas 55 c 1 and 55 c 2 with two electrical contacts, in other words, providing the conductive area 55 c 1 with two first electrical contacts 55 d 1 , and the conductive area 55 c 2 with two second electrical contacts 55 d 2 , as described before, improves communication reliability. In reality, the first and second electrical contacts 55 d 1 and 55 d 2 mean nothing but the scratch marks which the electrical contacts 56 a on the apparatus main assembly side make on the conductive areas ( 55 c 1 and 55 c 2 ) as the cartridge 7 is inserted into the apparatus main assembly A.
Next, referring to FIGS. 14 and 15 , the state of the cartridge 7 mounted in the apparatus main assembly A will be described. FIG. 14 is a schematic sectional view of the cartridge holding portion of the color image forming apparatus 100 , and the cartridges 7 therein, in accordance with the present invention, showing the structures thereof. FIG. 15 is a perspective view of the dielectric substrate 57 of the apparatus main assembly A, on which the beam emitting portion 53 , the beam receiving portion, and the communication unit 56 a (electrical contacts on main assembly side) are mounted.
The image forming apparatus 100 is capable of holding four cartridges 7 , which are inserted into the apparatus main assembly A, so that the photosensitive drum 1 of each cartridge 7 is located on the intermediate transferring member side, and also, so that the four cartridges 7 are vertically stacked. More specifically, the image forming apparatus 100 is provided with multiple (four) vertically stacked cartridge compartments 7 t into which the cartridges 7 Y, 7 M, 7 C, and 7 K different in the color of the developer they store are removably mountable. The beam entrance portion 51 a of the first beam guide 51 , and the beam exit portion (surface) 52 a of the second beam guide 52 , are located at the front end of the cartridge 7 in terms of the cartridge insertion direction, as shown in FIG. 1 . The beam entrance surface 51 a and beam exit surface 52 a are vertically spaced apart by a distance equal to the height of the developer storage portion 41 , and are parallel to each other. Therefore, the space between the beam entrance surface 51 a and beam exit surface 52 a constitutes a dead space. In the case of the cartridge 7 in this embodiment, the memory unit 55 for communicating with the main assembly of the printer 100 is placed in this space.
To describe these features in more detail with reference to FIG. 16 , the memory unit 55 is attached to the cartridge 7 so that when the cartridge 7 is in the main assembly of the printer 100 , the memory unit 55 is positioned between the horizontal plane A 1 coinciding with the center of the beam entrance portion (surface) 51 a , and the horizontal plane A 2 coinciding with the center of the exist portion (surface) 52 a . Further, referring to FIG. 17 , the memory 55 is placed so that the vertical plane A 3 coinciding with the centers of the beam entrance portion (surface) 51 a and beam exit portion (surface) 52 a , and perpendicular to the rotational axis R of the photosensitive drum 1 , crosses a part of the memory unit 55 .
In other words, the memory unit 55 is placed so that the beam entrance portion 51 a , the memory unit 55 , and the beam exit portion 52 a appear vertically aligned as seen from the direction perpendicular to the drawing. Therefore, the first beam guide 55 , the second beam guide 52 , and the memory 55 can be compactly placed in the cartridge 7 , making it possible to reduce the dimension of the cartridge 7 in terms of the direction parallel to the axial direction of the photosensitive drum 1 , and therefore, making it possible to reduce the size of the printer 100 in which the cartridge 7 is removably mountable.
Further, the memory unit 55 on the printer side, the first beam guide 51 , and the second beam guide 52 , are placed close to each other, and the communication unit 56 is attached to the main assembly of the printer 100 so that when the cartridge 7 is in the printer 100 , the communication unit 56 is placed between the horizontal plane A 1 coinciding with the center of the LED 53 , and the horizontal plane A 2 coinciding the center of the photo-transistor 54 , as shown in FIG. 16 .
Therefore, the LED 53 , the photo-transistor 54 , and the communication unit 56 can be placed on the same substrate. Further, the means for controlling these components can also be placed on the same substrate, making it unnecessary to distribute these components and controlling units among multiple substrates, and therefore, making it possible to reduce the component count of the apparatus main assembly A as well as the size of the apparatus main assembly A.
The cartridge 7 , the memory unit 55 of which is attached thereto so that the beam entrance portion 51 a , the beam exit portion 52 a , and the memory unit 55 of the cartridge 7 vertically align as seen from the direction perpendicular to the drawing, is preferable as the cartridge for the color printer 100 in which multiple cartridges are vertically stacked, as shown in FIG. 14 .
Further, the LED 53 for detecting the amount of the remaining developer, the photo-transistor 54 , the communication unit 56 as the electrical contact on the main assembly side, which are attached to the apparatus main assembly A so that they directly face the first beam guide 51 , the second beam guide 52 , and the memory unit 55 , can be compactly disposed in a single area.
Therefore, the LED 53 , the photo-transistor 54 , and the communication unit 56 can be compactly placed on the same rectangular substrate 57 as shown in FIG. 15 , making it possible to substantially reduce the electrical wiring and compactly place the components, contributing thereby to the reduction of the size of the printer 100 which employs multiple cartridges 7 .
As described above, in this embodiment, the memory unit 55 is placed in the aforementioned dead space. More specifically, referring to FIGS. 1 and 13 , the beam entrance surface 51 a and the beam exit surface 52 a are located at the front end of the cartridge 7 in terms of the cartridge insertion direction, and at the same location in terms of the lengthwise direction (parallel to the axial line of photosensitive drum 1 ). Further, the memory unit 55 is attached to the cartridge 7 so that a part of the memory unit 55 is crossed by the straight line S 1 connecting the outward edges of the beam entrance portion (surface) 51 a and the beam exit portion (surface) 52 a . More specifically, in this embodiment, the cartridge 7 is structured so that the straight line S 1 crosses the conductive area 55 c 1 of the memory unit 55 .
Therefore, it is possible to make the dimension of the cartridge 7 , in particular, the first frame 6 , smaller, in terms of the lengthwise direction, than the dimension of a process cartridge in accordance with the prior art, the beam entrance portion 51 a and the beam exit portion 52 a of which are located apart from each other, in terms of the lengthwise direction, in order to prevent the developer remainder amount detection beam from interfering with the beam for forming a latent image on the peripheral surface of the photosensitive drum 1 . Therefore, it is possible to reduce the overall size of the cartridge 7 .
Further, the beam entrance portion 51 a , the beam exit portion 52 a , and the memory unit 55 are attached to the cartridge 7 so that they vertically align as they are seen from the direction perpendicular to the drawing, and also, so that they are located close to each other. Therefore, the beam emitting portion (LED) 53 , the beam receiving portion (photo-transistor) 54 , and the communication unit 56 for detecting the amount of the remaining developer can be attached to the main assembly of the image forming apparatus 100 , employing the cartridge 7 structured as described, so that they are positioned close to each other.
Therefore, the beam emitting portion 53 ( 53 Y, 53 M, 53 C, and 53 K), the beam receiving portion 54 ( 54 Y, 54 M, 54 C, and 54 K), and the communication unit 56 ( 56 Y, 56 M, 56 C, and 56 K) can be placed on the same substrate 57 . Further, the means for controlling these components can also be placed on the same substrate 57 . Therefore, it is unnecessary to distribute the aforementioned components and controlling means among multiple substrates. Therefore, it is possible to reduce the component count and the size of the apparatus main assembly A.
Further, the beam emitting portion 53 , the beam receiving portion 54 , and the communication unit 56 of the color image forming apparatus 100 which employs multiple cartridges 7 , the beam entrance portion 51 a , the beam exit portion 52 a , and the memory unit 55 of which are attached to the cartridge 7 so that they are positioned close to each other, and also, so that they appear to vertically align as seen from the direction perpendicular to the drawing ( FIG. 13 ), and in which the multiple cartridges 7 are vertically stacked as shown in FIG. 14 , can be placed on the same rectangular substrate 57 for sensors, which extends in the vertical direction ( FIG. 15 ).
Therefore, it is unnecessary to distribute the aforementioned components and controlling means among multiple substrates, making it possible to substantially reduce wiring and compactly place them. Therefore, it is possible to reduce the component count and size of the image forming apparatus 100 .
Incidentally, the cartridge 7 in this embodiment is structured so that the aforementioned line S 1 crosses the conductive area 55 c 1 of the memory unit 55 . The line S 1 , however, may cross any part of the memory unit 55 as long as it crosses the memory unit 55 . Even if the line S 1 crosses a portion of the memory unit 55 different from the portion which the line S 1 crosses in this embodiment, the effects of the present invention are the same as those described above.
Further, in this embodiment, the electrical contacts 91 , 92 , and 93 of the cartridge 7 are located at the same end of the cartridge 7 as the end at which the first and second beam guides 51 and 52 , and the memory unit 55 , are located, in terms of the lengthwise direction (parallel to axial line of photosensitive drum 1 ), as shown in FIG. 5 . Therefore, the components of the apparatus main assembly A and the cartridge 7 , which electrically connect the apparatus main assembly A and cartridge 7 , can be compactly placed, making it possible to shorten the wiring between the power source (unshown) and electrical substrates of the apparatus main assembly A.
While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth, and this application is intended to cover such modifications or changes as may come within the purposes of the improvements or the scope of the following claims.
This application claims priority from Japanese Patent Application Nos. 349466/2003, 398939/2003 and 161219/2004, filed Oct. 8, 2003, filed Nov. 28, 2003 filed May 31, 2004, which are hereby incorporated by reference.
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A process cartridge detachably mountable to a main assembly of an apparatus, includes a drum, a developing member, a cartridge frame including a developer accommodating portion, a first light guide adjacent one end of the cartridge frame and a leading end with respect to a cartridge mounting direction and including a light entrance portion opposed to an emitting portion to receive detecting light when the process cartridge is mounted to the main assembly and guiding the detecting light to cross with a developer accommodating space in the developer accommodating container, a second light guide adjacent the one end and the leading end, and including a light exit portion and directing, the detecting light having passed through the developer accommodating space to the light receiving portion, and a memory member communicatable with the main assembly and adjacent the one end o and the leading and including a cartridge electrical contact.
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FIELD OF THE INVENTION
This invention relates to a sintering process. More particularly, this invention relates to a sintering process wherein sintering in solid phase is followed by brief heat treatment with a liquid phase.
BACKGROUND OF THE INVENTION
In conventional sintering of multiphase tungsten alloys, the metals are mixed as powders, pressed, and sintered in liquid phase. With tungsten alloys this is done at temperatures higher than 1450° C. Within the liquid phase at least three things must occur:
(1) formation of alloy;
(2) coating of the tungsten granules; and
(3) densification of the pressed body.
The necessarily long stay in the liquid phase results in strong granule growth, which results in strength decrease.
From U.S. Pat. No. 4,498,395, incorporated herein by reference, are known tungsten alloy powders which are already pre-alloyed, i.e., the tungsten grains are already coated with the binder phase. Pressed bodies of this powder are compacted by solid phase sintering, and the sintered parts are characterized by a polygonal structure of the tungsten phase. The structure is considerably finer than the ones of conventional tungsten heavy metal compositions which are prepared from the individual powders (W, Ni, Fe) by mixing, pressing, and sintering in liquid phase. The polygonal structure of the tungsten particles in compositions prepared according to U.S. Pat. No. 4,498,395 shows, however, a high contiguity of the tungsten phase, which means that there is a multitude of tungsten-tungsten grain boundaries. This situation can negatively effect the mechanical properties of the sintered tungsten heavy metals. There is impairment of the tensile strength and elongation at break especially if the alloy contains interstitial impurities such as oxygen, phosphorus, or sulfur and/or other components which are insoluble in tungsten. These impurities separate off at the tungsten grain boundaries and cause the grain boundary brittleness typical of tungsten.
OBJECTS OF THE INVENTION
It is an object of the invention to provide a novel sintering process.
It is also an object of the invention to provide a novel sintering process wherein sintering in the solid phase is followed by brief heat treatment in the liquid phase.
It is a further object of the invention to provide sintered tungsten alloys having improved properties.
These and other objects of the invention will become apparent in the description below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 represents a micrograph of a cross-section of a solid-phase sintered piece; and
FIG. 2 represents a micrograph of a cross-section of a sintered piece prepared according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
The invention herein relates to a sintering process for the preparation of sintered bodies with a high tungsten content with a fine-grained structure (smaller than 10 μm of the tungsten grains), which show a low contiguity of the tungsten phase. The problem of preparing suitable tungsten alloys is solved according to the invention by sintering a porous form of pressed tungsten alloy powders in solid phase, followed by brief heat treatment with a liquid phase.
The heat treatment in the liquid phase leads to a rounding of the previously polygonal tungsten grains through dissolution in the molten-liquid binder phase, without the simultaneous occurrence of significant grain growth. This results in an almost spherical shape of the tungsten grains, which decreases the harmful contiguity of the tungsten phase since spheres have less contact planes among each other than do polygons.
The claimed process permits a combination of the advantages of solid phase sintering with liquid phase sintering, without having to contend with the disadvantages of the conventional liquid phase sintering, namely, grain growth. Granular fineness is necessary because it increases strength. (Increase of tensile strength according to the Hall-Petch Equation ##EQU1## wherein α is the mean grain size.)
Grain growth barely occurs in the process according to the invention since the liquid phase is present only during a very short time. During the course of the liquid phase only a rounding of the tungsten granules occurs as a result of the high interfacial tension of tungsten in contact with the liquid binder phase. Alloy formation and densification of the pressed body have already occurred during the powder preparation or during the solid phase sintering, respectively.
The heat treatment with liquid phase preferably lasts from about 2 to 10 minutes, more preferably from about 3 to 8 minutes. After this time the tungsten grains are extensively rounded. Since by the appearance of the liquid phase the sinter body is already densely sintered (remaining porosity <1%), and since there is a relatively high contiguity of the tungsten phase, the demixing of tungsten and binder phases, which occurs with the usual liquid phase sintering, will not happen.
The stay in the liquid phase, which is short as compared to liquid phase sintering, is sufficient to achieve the desired structure transformation. Alloy formation and densification of the porous parts have already occurred at the time of structure transformation, in contrast to liquid phase sintering.
During the solid phase sintering of porous form parts of pressed tungsten heavy metal powder, at least a part of the sintering is preferably carried out under a hydrogen flow to remove the residual oxygen present in the tungsten alloy powders. It is important that the oxygen is substantially removed as long as the sinter parts have open pores. Subsequent to sintering under a hydrogen flow, a vacuum heating should take place to remove the hydrogen dissolved in the sinter part. The dissolved hydrogen can, however, also be removed by heating in an inert gas (e.g., argon). Removal of the hydrogen improves the mechanical properties of the sinter parts.
The solid phase sintering can also be carried out partly in vacuum. In the event there is no subsequent sintering under hydrogen atmosphere, a separate vacuum heating to remove the hydrogen dissolved in the sinter parts can be omitted.
According to the invention the heat treatment with liquid phase can take place immediately after the solid phase sintering or only after the vacuum heating. The atmosphere there can be hydrogen or an inert gas. However, the heat treatment can also occur under high vacuum.
It is important that the time during which the liquid phase is present is well controlled. Too long a stay in the liquid phase leads to undesirable grain growth and thus has to be avoided. It is also important to conduct heating and cooling during the liquid phase as rapidly as possible.
In cases where the heat treatment is carried out under hydrogen atmosphere, a bubble formation in the binder by outgassing of the dissolved hydrogen during cooling-down to the solidification temperature must be avoided, since it can lead to pore formation. For this purpose the cooling rate near the solidification temperature should not be greater than 3° C./minute.
After the solidification range is passed, a further quick cooling (approximately 100° C./minute) to temperatures below about 800° C. also leads to additional improvement of the mechanical properties. The reason for this is presumably the prevention of grain boundary segregation by interfering impurities. Below 800° C. the segregation process is so slow that a normal oven cooling (approximately 20° C./minute) suffices to prevent an impairment of the mechanical properties.
The ductility of the sinter parts is increased by the process according to the invention. Breaking elongation increases because of the structure transformation without significant strength decrease, for example, from about 15 to 40 percent.
Strength and elongation properties of the sintered parts can be modified within a wide range by adjustment of the tungsten grain size via the soaking time in the liquid phase during the structure transformation. Increasing grain growth through heat treatment of longer duration in liquid phase leads to decreasing strength with increasing elongation at break.
The effect of the process according to the invention can perhaps be better appreciated by referring to FIGS. 1 and 2. FIG. 1 shows a metallographic micro-section, i.e., a microscopic photograph, or micrograph, of a solid phase sintered tungsten heavy metal alloy with a 90% tungsten content. The polygonal structure of the tungsten grains, which leads to a considerable contiguity of the tungsten phase, can be seen.
FIG. 2 shows a micro-section of a tungsten heavy metal alloy after heat treatment with liquid phase according to the invention. The tungsten granules are barely larger than in the solid phase sintered state. However, due to the rounding of the tungsten granules, a significantly lower contiguity results.
The following examples are intended to illustrate the invention and should not be construed as limiting the invention thereto.
EXAMPLES
Example 1
A tungsten heavy metal alloy powder of the composition 90% W, 6% Ni, 2% Co, and 2% Fe is pressed with a pressure of 300N/mm 2 . The pressed body is sintered under a hydrogen flow at 1300° C. for five hours and then degassed in a vacuum of 10 -5 mbar at 1050° C. for six hours. The sintered part is subsequently heat treated in said vacuum at 1470° C. for five minutes and then rapidly cooled down. The tensile strength of the sample is 1150N/mm 2 with an elongation at break of 30%.
Example 2
A tungsten heavy metal alloy powder having the composition mentioned in Example 1 is pressed with a pressure of 300N/mm 2 . The pressed body is pre-sintered under a hydrogen flow at 900° C. for ten hours and then final-sintered in a vacuum of 10 -5 mbar at 1360° C. for 20 hours. The sintered part is subsequently heat treated in said vacuum at 1470° C. for 10 minutes. The sample has a tensile strength of 1100N/mm 2 with an elongation at break of 40%.
The preceding specific embodiments are illustrative of the practice of the invention. It is to be understood, however, that other expedients known to those skilled in the art or disclosed herein, may be employed without departing from the spirit of the invention or the scope of the appended claims.
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This invention relates to a sintering process. More particularly, this invention relates to a process for preparing a sintered form having a tungsten content which comprises the steps of:
(a) sintering a porous form of pressed tungsten alloy powders having a high tungsten content in solid phase, and
(b) heat treating the sintered part from step (a) in a liquid phase.
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This application claims the benefits of Provisional Application No. 60/318,691 filed Sep. 12, 2001.
BACKGROUND TO THE INVENTION
1. Field of the Invention
The invention concerns cosmetic compositions of improved aesthetic properties having low pH and containing organic sunscreen agents.
2. The Related Art
Sunscreen agents are commonly used in compositions intended for cosmetic application to the face and other exposed skin areas. These preparations are formulated as creams, lotions or oils containing as the agent an organic ultraviolet radiation absorbing chemical compound. The agent blocks passage of erythematogenic radiation thereby preventing its penetration into the skin.
High quality skinfeel properties are not always easy to achieve where the compositions contain sunscreen agents. The challenge is especially magnified with low pH systems. Organic sunscreens often have a sticky or tacky feel. These attributes must be counteracted when formulated into an aqueous emulsion composition. Formulating an aesthetically pleasant system incorporating these actives remains a challenge to chemists.
Sunscreen compositions have been well documented in the patent literature. For instance, U.S. Pat. No. 5,505,935 (Guerrero et at.) discloses sunscreen compositions wherein ethylene/vinyl acetate copolymer and poly(methyl methacrylate) particles were found useful as boosters for the sun protection factor (SPF).
Accordingly, it is an advantage of the present invention to provide an organic sunscreen agent formulated cosmetic composition with improved skinfeet, especially one with low tackiness.
Another advantage of the present invention is to provide a sunscreen agent formulated cosmetic composition that is an aqueous emulsion of low pH having good skinfeel properties.
These and other advantages of the present invention will become more apparent from consideration of the summary and detailed discussion which follows.
SUMMARY OF THE INVENTION
A cosmetic composition is provided which includes:
(i) from about 0.1 to about 15% by weight of an organic sunscreen agent having a chromophoric group active within the ultraviolet radiation range from 290 to 400 nm;
(ii) from about 0.01 to about 10% by weight of a water-insoluble powdered polymer formed as porous particles having an Oil Absorbance (castor oil) value ranging from about 90 to about 500 ml/100 gm; and
(iii) from about 1 to about 99% of water, the composition having a pH of less than 7.
DETAILED DESCRIPTION OF THE INVENTION
Now it has been found that water-insoluble polymeric powders in porous particle form can modify the tacky skinfeel normally associated with organic sunscreen agents. Excellent skinfeel without any perceptible tackiness is achieved, even in systems having extremely low pH.
A first element of compositions according to the present invention is that of a water-insoluble material in the form of polymeric porous spherical particles. By the term “porous” is meant an open or closed cell structure. Preferably the particles are not hollow beads. Average particle size may range from about 0.1 to about 100, preferably from about 1 to about 50, more preferably greater than 5 and especially from 5 to about 15, optimally from about 6 to about 10 micron. Organic polymers or copolymers are the preferred materials and can be formed from monomers including the acid, salt or ester forms of acrylic acid, methacrylic acid, methylacrylate, ethylacrylate, ethylene, propylene, vinylidene chloride, acrylonitrile, maleic acid, vinyl pyrrolidone, styrene, butadiene and mixtures thereof. The polymers are especially useful in cross-linked form. Cells of the porous articles may be filled by a gas which can be air, nitrogen or a hydrocarbon. Oil Absorbance (castor oil) is a measure of porosity and may range from about 90 to about 500, preferably from about 100 to about 200, optimally from about 120 to about 180 ml/100 grams. Density of the particles may range from about 0.08 to 0.55, preferably from about 0.15 to 0.48 g/cm 3 .
Illustrative porous polymers include polymethylmethacrylate and cross-linked polystyrene. Most preferred is polymethyl methacrylate available as Ganzpearl® 820 available from Presperse, Inc., Piscataway, N.J., known also by its INCI name of Methyl Methacrylate Crosspolymer.
Amounts of the water-insoluble polymeric porous particles may range from about 0.01 to about 10%, preferably from about 0.1 to about 5%, optimally from about 0.3 to about 2% by weight of the composition.
A second element of compositions according to the present invention is that of an organic sunscreen agent having at least one chromophoric group absorbing within the ultraviolet ranging from 290 to 400 nm. Chromophoric organic sunscreen agents may be divided into the following categories (with specific examples) including: p-Aminobenzoic acid, its salts and its derivatives (ethyl, isobutyl, glyceryl esters; p-dimethylaminobenzoic acid); Anthranilates (o-aminobenzoates; methyl, menthyl, phenyl, benzyl, phenylethyl, linalyt, terpinyl, and cyclohexenyl esters); Salicylates (octyl, amyl, phenyl, benzyl, menthyl, glyceryl, and dipropyleneglycol esters);
Cinnamic acid derivatives (menthyl and benzyl esters, alpha-phenyl cinnamonitrile; butyl cinnamoyl pyruvate); Dihydroxycinnamic acid derivatives (umbelliferone, methylumbelliferone, methylaceto-umbelliferone); Trihydroxycinnamic acid derivatives (esculetin, methylesculetin, daphnetin, and the glucosides, esculin and daphnin); Hydrocarbons (diphenylbutadiene, stilbene); Dibenzalacetone and benzalacetophenone; Naphtholsulfonates (sodium salts of 2-naphthol-3,6-disulfonic and of 2-naphthol-6,8-disulfonic acids); Dihydroxy-naphthoic acid and its salts; o- and p-Hydroxybiphenyldisulfonates; Coumarin derivatives (7-hydroxy, 7-methyl, 3-phenyl); Diazoles (2-acetyl-3-bromoindazole, phenyl benzoxazole, methyl naphthoxazole, various aryl benzothiazoles); Quinine salts (bisulfate, sulfate, chloride, oleate, and tannate); Quinoline derivatives (8-hydroxyquinoline salts, 2-phenylquinoline); Hydroxy- or methoxy-substituted benzophenones; Uric and vilouric acids; Tannic acid and its derivatives (e.g., hexaethylether); (Butyl carbityl) (6-propyl piperonyl) ether; Hydroquinone; Benzophenones (Oxybenzone, Sulisobenzone, Dioxybenzone, Benzoresorcinol, 2,2′, 4,4′-Tetrahydroxybenzophenone, 2,2′-Dihydroxy-4,4′-dimethoxybenzophenone, Octabenzone; 4-lsopropyldibenzoylmethane; Butylmethoxydibenzoylmethane; Etocrylene; and 4-isopropyl-dibenzoylmethane).
Particularly useful are: 2-ethylhexyl p-methoxycinnamate, 4,4′-t-butyl methoxydibenzoylmethane, 2-hydroxy-4-methoxybenzophenone, octyidimethyl p-aminobenzoic acid, digalloyLtrioleate, 2,2-dihydroxy-4-methoxybenzophenone, ethyl 4-[bis(hydroxypropyt)]aminobenzoate, 2-ethylhexyl-2-cyano-3,3-diphenylacrylate, 2-ethythexylsalicytate, glyceryl p-aminobenzoate, 3,3,5-trimethytcyclohexylsaticylate, methylanthranitate, p-dimethylaminobenzoic acid or aminobenzoate, 2-ethylhexyl p-dimethylaminobenzoic, 2-phenytbenzimidazole-5-sulfonic acid, 2-(p-dimethylaminophenyl)-5-sulfoniobenzoxazoic acid and mixtures thereof.
Suitable commercially available organic sunscreen agents are those identified under the following table.
TABLE I
CTFA NAME
TRADE NAME
SUPPLIER
Benzophenone-3
UVINUL M-40
BASF Chemical Co.
Benzophenone-4
UVINUL MS-40
BASF Chemical Co.
Benzophenone-8
SPECTRA-SORB UV-24
American Cyanamid
DEA-Methoxycinnamate
BERNEL HYDRO
Bernel Chemical
Ethyl
AMERSCREEN P
Amerchol Corp.
dihydroxypropyl-PABA
Glyceryl PABA
NIPA G.M.P.A.
Nipa Labs.
Homosatate
KEMESTER HMS
Humko Chemical
Menthyl anthranilate
SUNAROME UVA
Fetton Worldwide
Octocrylene
UVINUL N-539
BASF Chemical Co.
Octyl dimethyl PABA
AMERSCOL
Amerchol Corp.
Octyl methoxycinnamate
PARSOL MCX
Bernel Chemical
Octyl salicylate
SUNAROME WMO
Fetton Worldwide
PABA
PABA
National Starch
2-Phenylbenzimidazole-
EUSOLEX 232
EM Industries
5-sulphonic acid
TEA salicylate
SUNAROME W
Fetton Worldwide
2-(4-Methylbenzylidene)-
EUSOLEX 6300
EM Industries
camphor
Benzophenone-1
UVINUL 400
BASF Chemical Co.
Benzophenone-2
UVINUL D-50
BASF Chemical Co.
Benzophenone-6
UVINUL D-49
BASF Chemical Co.
Benzophenone-12
UVINUL 408
BASF Chemical Co.
4-Isopropyl dibenzoyl
EUSOLEX 8020
EM Industries
methane
Butyl methoxy dibenzoyl
PARSOL 1789
Givaudan Corp.
methane
Etocrylene
UVINUL N-35
BASF Chemical Co.
Amounts of the organic sunscreen agent will range from about 0.1 to about 15%, preferably from about 0.5% to about 10%, optimally from about 1% to about 8% by weight of the composition.
Compositions of the present invention wilt contain water in amounts 5 from about 1 to about 99%, preferably from about 5 to about 90%, more preferably from about 35 to about 70%, optimally between about 40 and about 60% by weight. Ordinarily the compositions will be water and oil emulsions of the W/O or O/W variety.
Compositions of the present invention wilt have a pH less than 7, preferably ranging from about 1 to 6.8, more preferably ranging from about 1 to about 6.5, still more preferably from about 2.5 to about 4.5, optimally from about 3 to about 3.8.
Where the compositions are emulsions, they may comprise emollient materials in the form of mineral oils, silicone oils and synthetic or natural esters. Amounts of the emollients may range from about 0.1 to about 30%, preferably between about 0.5 and 20% by weight.
Silicone oils may be divided into the volatile and non-volatile variety. The term “volatile” as used herein refers to those materials which have a measurable vapor pressure at ambient temperature. Volatile silicone oils are preferably chosen from cyclic or linear polydimethylsiloxanes containing from about 3 to about 9, preferably from about 4 to about 5, silicon atoms.
Linear volatile silicone materials generally have viscosities less than about 5 centistokes at 25° C. while cyclic materials typically have viscosities of less than about 10 centistokes.
Nonvolatile silicone oils useful as an emollient material include polyalkyl siloxanes, polyalkylaryl siloxanes and polyether siloxane copolymers. The essentially non-volatile polyalkyl siloxanes useful herein include, for example, polydimethyl siloxanes with viscosities of from about 5 to about 100,000 centistokes at 25° C.
Among suitable ester emollients are:
(1) Alkenyl or alkyl esters of fatty acids having 10 to 20 carbon atoms. Examples thereof include isopropyl palmitate, isopropyl isostearate, isononyl isonanonoate, oleyl myristate, oleyl stearate, and oleyl oleate.
(2) Ether-esters such as fatty acid esters of ethoxylated fatty alcohols.
(3) Polyhydric alcohol esters. Ethylene glycol mono and di-fatty acid esters, diethylene glycol mono- and di-fatty acid esters, polyethylene glycol (200-6000) mono- and di-fatty acid esters, propylene glycol mono- and di-fatty acid esters, polypropylene glycol 2000 monooleate, polypropylene glycol 2000 monostearate, ethoxylated propylene glycol monostearate, glyceryl mono- and di-fatty acid esters, polyglycerol poly-fatty esters, ethoxylated glyceryl mono-stearate, 1,3-butylene glycol monostearate, 1,3-butylene glycol distearate, polyoxyethylene polyol fatty acid ester, sorbitan fatty acid esters, and polyoxyethylene sorbitan fatty acid esters are satisfactory polyhydric alcohol esters.
(4) Wax esters such as beeswax, spermaceti, myristyl myristate, stearyl stearate.
(5) Sterols esters, of which soya sterol and cholesterol fatty acid esters are examples thereof.
The most preferred esters are dicaprytyl ether and isopropyl isostearate.
Fatty acids having from 10 to 30 carbon atoms may also be included in the compositions of this invention. Illustrative of this category are pelargonic, tauric, myristic, palmitic, stearic, isostearic, hydroxystearic, oleic, linoleic, ricinoleic, arachidic, behenic and erucic acids.
Humectants of the polyhydric alcohol-type may also be included in the compositions of this invention. The humectant aids in increasing the effectiveness of the emollient, reduces scaling, stimulates removal of built-up scale and improves skin feel. Typical polyhydric alcohols include glycerol (also known as glycerin), polyalkylene glycols and more preferably alkylene polyols and their derivatives, including propytene glycol, dipropylene glycol, polypropylene glycol, polyethylene glycol and derivatives thereof, sorbitol, hydroxypropyl sorbitol, hexylene glycol, 1,3-butylene glycol, 1,2,6-hexanetriol, ethoxylated glycerol, propoxylated glycerol and mixtures thereof. For best results the humectant is preferably glycerin. The amount of humectant may range anywhere from 0.5 to 30%, preferably between 1 and 15% by weight of the composition.
Cosmetic compositions of the present invention may be in any form. These forms may include lotions, creams, roll-on formulations, mousses, aerosol sprays and cloth- or pad-apptied formulations.
Emulsifiers may also be present in cosmetic compositions of the present invention. Total concentration of the emulsifier may range from about 0.1 to about 40%, preferably from about 1 to about 20%, optimally from about 1 to about 5% by weight of the total composition. The emulsifier may be selected from the group consisting of anionic, nonionic, cationic and amphoteric actives. Particularly preferred nonionic surfactants are those with a C 10 -C 20 fatty alcohol or acid hydrophobe condensed with from about 2 to about 100 moles of ethylene oxide or propylene oxide per mote of hydrophobe; C 2 -C 10 alkyl phenols condensed with from 2 to 20 motes of alkylene oxide; mono- and di- fatty acid esters of ethylene glycol; fatty acid monoglyceride; sorbitan, mono- and di- C 8 -C 20 fatty acids; and polyoxyethylene sorbitan as well as combinations thereof. Alkyl polyglycosides and saccharide fatty amides (e.g. methyl gluconamides) are also suitable nonionic emulsifiers.
Preferred anionic emulsifiers include soap, alkyl ether sulfate and sulfonates, alkyl sulfates and sulfonates, alkylbenzene sulfonates, alkyl and dialkyt sulfosuccinates, C 8 -C 20 acyl isethionates, C 8 -C 20 alkyl ether phosphates, alkylethercarboxylates and combinations thereof.
Preservatives can desirably be incorporated into the cosmetic compositions of this invention to protect against the growth of potentially harmful microorganisms. Suitable traditional preservatives for compositions of this invention are alkyl esters of para-hydroxybenzoic acid. Other preservatives which have more recently come into use include hydantoin derivatives, propionate salts, and a variety of quaternary ammonium compounds. Cosmetic chemists are familiar with appropriate preservatives and routinely choose them to satisfy the preservative challenge test and to provide product stability. Particularly preferred preservatives are iodopropynyl butyl carbamate, phenoxyethanol, methyl paraben, propyl paraben, imidazolidinyl urea, sodium dehydroacetate and benzyl alcohol. The preservatives should be selected having regard for the use of the composition and possible incompatibilities between the preservatives and other ingredients in the emulsion. Preservatives are preferably employed in amounts ranging from about 0.01% to about 2% by weight of the composition.
Thickening agents may be included in compositions of the present invention. Particularly useful are the polysaccharides. Examples include starches, natural/synthetic gums and cellulosics. Representative of the starches are chemically modified starches such as aluminum starch octenylsuccinate. Suitable gums include xanthan, sclerotium, pectin, karaya, arabic, agar, guar, carrageenan, alginate and combinations thereof. Suitable cellulosics include hydroxypropyl cellulose, hydroxypropyl methylcellulose, ethylcellulose and sodium carboxy methylcellulose. Synthetic polymers are still a further class of effective thickening agent. This category includes crosslinked polyacrylates such as the Carbomers, polyacrylamides such as Sepigel® 305 and taurate copolymers such as Aristoflex® AVC, the latter identified by its INCI nomenclature of Acryloyl Dimethyltaurate/Vinyl Pyrrolidone Copolymer.
Amounts of the thickener may range from about 0.001 to about 5%, preferably from about 0.1 to about 2%, optimally from about 0.2 to about 0.5% by weight.
For additional thickening, it is preferred to have magnesium aluminum silicate, commercially available as Veegum®, sold by the R.T. Vanderbilt Company. Amounts of this inorganic thickening agent may range from about 0.01 to about 10%, preferably from about 0.5 to about 1.2% by weight.
Optionally the compositions may include an alpha- or beta-hydroxycarboxylic acid. Most preferred are the free acid, salts or esters of glycolic acid, lactic acid, 2-hydroxyoctanoic acid, gluconolactone and mixtures thereof. Amounts of these materials may range from about 0.01 to about 20%, preferably from about 0.2 to about 10%, optimally from about 1 to about 5% by weight.
Minor adjunct ingredients may also be present in the cosmetic compositions. Among them may be the vitamins such as Vitamin A Palmitate, Vitamin C and derivatives (e.g. ascorbyl palmitate or magnesium ascorbyl phosphate), Vitamin E Acetate and DL-panthenol. Also useful are: retinol, ceramides and herbal extracts including green tea and chamomile.
Colorants, fragrances and abrasives may also be included in compositions of the present invention. Each of these substances may range from about 0.05 to about 5%, preferably between 0.1 and 3% by weight.
Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material ought to be understood as modified by the word “about”.
The term “comprising” is meant not to be limiting to any subsequently stated elements but rather to encompass non-specified elements of major or minor functional importance. In other words the listed steps, elements or options need not be exhaustive. Whenever the words “including” or “having” are used, these terms are meant to be equivalent to “comprising” as defined above.
The following Examples will more fully illustrate the embodiments of this invention. All parts, percentages and proportions referred to herein and in the appended claims are by weight unless otherwise indicated.
EXAMPLES 1-8
Typical formulations according to the present invention are described below.
Example (Weight %)
Ingredients
1
2
3
4
5
6
7
8
Disodium EDTA
0.05
0.05
0.05
0.05
0.05
0.05
0.05
0.05
Methyl Paraben
0.15
0.15
0.15
0.15
0.15
0.15
0.15
0.15
Aloe Vera
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
Magnesium Aluminum Silicate
0.60
0.60
0.60
0.60
0.60
0.60
0.60
0.60
Glycerin
5.00
5.00
5.00
5.00
5.00
5.00
5.00
5.00
Butylene Glycol
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
Xanthan Gum
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.20
Cetearyl Alcohol
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
Sorbitan Stearate
1.10
1.10
1.10
1.10
1.10
1.10
1.10
1.10
PEG-100 Stearate
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
Glyceryl Dilaurate
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
Stearic Acid
3.00
3.00
3.00
3.00
3.00
3.00
3.00
3.00
Sucrose Polystearate
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
Propylparaben
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
Tocopheryl Acetate
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
Ascorbyl Palmitate
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
Octyl Methoxycinnamate
2.00
1.00
2.00
4.00
4.00
1.00
2.00
2.00
Dimethicone
1.00
2.00
1.00
0.50
3.00
1.00
5.00
1.00
Dicaprylyl Ether
4.00
3.00
6.00
6.00
2.00
3.00
0.50
0.50
Isopropyl Isostearate
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
Glycolic Acid (80% Active)
8.00
11.40
8.40
4.60
10.60
12.40
10.80
8.80
Ammonium Hydroxide
1.80
2.80
1.80
0.50
2.40
3.00
2.50
1.80
Polymethyl Methacrylate
1.00
0.50
0.50
1.50
1.50
3.00
3.00
0.10
(Ganzpearl ® 820)
Aluminum Starch Octenylsuccinate
2.00
2.00
3.00
1.50
0.50
3.00
2.50
2.00
Acryloyl Dimethyltaurate Copolymer (7%
1.00
1.30
1.50
2.00
4.00
0.50
0.50
1.00
Active)
Bisabolol
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
Retinol
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.02
Fragrance
0.03
0.03
0.03
0.03
0.03
0.03
0.03
0.03
Water
Balance
Balance
Balance
Balance
Balance
Balance
Balance
Balance
EXAMPLE 9
Comparative experiments are presented herein against the COVABEADS product of LCW, a Sensient Company. COVABEAD is a polymethylmethyacrylate solid non-porous spherical particle. Oil Absorbance (castor oil) of the COVABEAD particles is 80 ml/100 grams. This particle was compared to that of the present invention, namely Ganzpearl® 820 (identified in the Tables below as GMP 0820) which is a porous particle with Oil Absorbance (castor oil) of 170 ml/100 gm. These particles were evaluated in a base formula whose components are listed in Table I.
TABLE I
Ingredient Name
Weight %
Phase A
Mineral Water Extract
0.10
Disodium EDTA
0.10
Dl Panthenol
0.20
Sodium Lactate
0.10
Sodium PCA (50% in water)
0.20
Green Tea Extract
0.10
Grapeseed Extract
0.10
Glycerin
5.00
Water
Balance
Phase B
Carbopol Ultrez 10 ®
0.50
Phase C
Triethanolamine (99% active)
2.10
Parsol HS ®
2.00
Deionized Water
10.00
Phase D
Myristyl Alcohol
0.50
Sorbitan Stearate
1.10
Cetyl Alcohol
0.50
Glyceryl Dilaurate
0.50
Stearyl Alcohol
0.50
Sucrose Stearate
0.50
PEG-100 Stearate
0.50
Stearic Acid
0.25
Vitamin E Acetate
0.20
Linolieic Acid
0.10
Linoleamide MEA
0.10
Cholesterol
0.20
Phase E
Parsol MCX ®
5.5
Dermablock OS ®
3
Parsol 1789 ®
2
Phase F
Permethyl 99A ®
4.50
Phase G
Water
0.50
Ceramide/Phylosphingosine Mixture
0.01
Phase H
Iodopropynyl Butyl Carbamate
0.10
Phenoxyethanol
0.60
Phase I
Bisabolol
0.20
Vitamin A Palmitate
0.01
Fragrance
0.30
The base formula was prepared by charging a main beaker with Phase A. This was mixed and stirred until homogeneous at 75-80° C. Phase B was added to the stirred Phase A and mixed until dispersed. Temperature was maintained while charging Phase C into the main beaker. Agitation was continued until all components were uniformly dispersed. Phase D was then melted and mixed at 75° C. Phase E was pre-mixed and the polymethylmethacrylate particles of either COVABEAD or Ganzpearl® were heated at 75° C. and then added to Phase D. The resultant combined Phases D/E were then added to the main beaker under homogenization conditions for five minutes. Phase F was then added to the main batch and homogenization continued for an additional five minutes. The batch was cooled to 40-45° C. whereupon Phases G and H were added. Temperature was reduced to 35° C. and Phase I combined into the mixture until completely uniform.
A clinical study was conducted with an expert panel of n panelists evaluating skinfeel properties of the base formula with different levels of COVABEADS and Ganzpearl® 820. Results are reported in the Tables below.
TABLE II
Product That Rubs in Faster*
Product (n = 9)
Frequency
1.5% GMP 0820
4
1.5% COVABEAD
4
No Difference
1
Product (n = 8)
Frequency
0.5% GMP 0820
4
0.5% COVABEAD
2
No Difference
2
Product (n = 10)
Frequency
1.0% GMP 0820
2
1.0% COVABEAD
6
No Difference
2
Product (n = 9)
Frequency
2.0% GMP 0820
5
2.0% COVABEAD
4
No Difference
0
*For the product chosen above, how much faster
1 = “Slightly Faster”,
5 = “Much Faster”
TABLE III
Feels Drier to the Touch During Application*
Product
Frequency
1.5% GMP 0820
7
1.5% COVABEAD
0
No Difference
2
0.5% GMP 0820
4
0.5% COVABEAD
1
No Difference
3
1.0% GMP 0820
4
1.0% COVABEAD
4
No Difference
2
2.0% GMP 0820
6
2.0% COVABEAD
3
No Difference
0
*For the Product Chosen Above, How Much Drier
1 = “Slightly Drier”,
5 = “Much Drier”
TABLE IV
Feels Less Oily During Application*
Product
Frequency
1.5% GMP 0820
6
1.5% COVABEAD
1
No Difference
2
0.5% GMP 0820
3
0.5% COVABEAD
2
No Difference
3
1.0% GMP 0820
5
1.0% COVABEAD
2
No Difference
3
2.0% GMP 0820
6
2.0% COVABEAD
1
No Difference
2
*For the Product Chosen Above, How Much Less Oily
1 = “Slightly Less Oily”,
5 = Much Less Oily”
TABLE V
Feels Less Sticky During Rub In*
Product
Frequency
1.5% GMP 0820
3
1.5% COVABEAD
1
No Difference
5
0.5% GMP 0820
2
0.5% COVABEAD
3
No Difference
3
1.0% GMP 0820
8
1.0% COVABEAD
1
No Difference
1
2.0% GMP 0820
8
2.0% COVABEAD
0
No Difference
1
*For the Product Chosen Above, How Much Less Sticky
1 = “Slightly Less Sticky”,
5 = “Much Less Sticky”
TABLE VI
Feels Less Sticky on Face*
Product
Frequency
1.5% GMP 0820
3
1.5% COVABEAD
2
No Difference
4
0.5% GMP 0820
3
0.5% COVABEAD
3
No Difference
2
1.0% GMP 0820
4
1.0% COVABEAD
3
No Difference
3
2.0% GMP 0820
5
2.0% COVABEAD
2
No Difference
2
*For the Product Chosen Above, How Much Less Sticky
1 = “Slightly Less Sticky”,
5 = “Much Less Sticky”
TABLE VII
Feels Less Oily On Face*
Product
Frequency
1.5% GMP 0820
7
1.5% COVABEAD
1
No Difference
1
0.5% GMP 0820
2
0.5% COVABEAD
2
No Diffence
4
1.0% GMP 0820
4
1.0% COVABEAD
4
No Difference
2
2.0% GMP 0820
6
2.0% COVABEAD
2
No Difference
1
*For the Product Chosen Above, How Much Less Oily
1 = “Slightly Less Oily”,
5 = “Much Less Oily”
TABLE VIII
Feels Drier on Face*
Product
Frequency
1.5% GMP 0820
6
1.5% COVABEAD
1
No Difference
1
0.5% GMP 0820
4
0.5% COVABEAD
2
No Difference
2
1.0% GMP 0820
5
1.0% COVABEAD
3
No Difference
2
2.0% GMP 0820
5
2.0% COVABEAD
3
No Difference
1
*For the Product Chosen Above, How Much Drier
1 = “Slightly Drier”,
5 = “Much Drier”
TABLE IX
Overall Preference
Product
Frequency
1.5% GMP 0820
4
1.5% COVABEAD
2
No Preference
3
0.5% GMP 0820
5
0.5% COVABEAD
1
No Preference
2
1.0% GMP 0820
5
1.0% COVABEAD
2
No Preference
3
2.0% GMP 0820
5
2.0% COVABEAD
1
No Preference
3
In general, the expert panel for most of the concentration range tested found the GanzpearL® 820 (GMP 0820) formulation preferable over the one with COVABEADS. Particularly, the panelists considered Ganzpearl® 820 superior in the attributes of “feels dryer to the touch during application”, “feels less oily during application”, “feels less oily on face”, “feels dryer on face” and in “overall preference”.
The foregoing description and examples illustrate selected embodiments of the present invention. In light thereof variations and modifications will be suggested to one skilled in the art, all of which are within the spirit and purview of this invention.
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A cosmetic composition is provided which includes an organic sunscreen agent, a water-insoluble polymeric powder of porous particles, and an aqueous system wherein pH is less than 7. The porous particles remove the tackiness normally associated with organic sunscreen agents and low pH systems thereby providing a resultant composition of excellent skinfeel.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation of U.S. application Ser. No. 11/900,853, filed on Sep. 13, 2007, which is a divisional of U.S. application Ser. No. 11/540,376 filed on Sep. 29, 2006, now U.S. Pat. No. 7,476,131.
TECHNICAL FIELD
[0002] The present invention relates generally to electronic devices, such as medical devices, and more particularly to reducing crosstalk in such devices.
BACKGROUND
[0003] This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
[0004] Medical devices such as those used for monitoring a patient's vital sign or other physiologic variable, are commonly comprised of a patient-contacting signal transducer and a monitor that connects to the transducer, processes the signals, and provides information to the caregiver. Typically, the transducer is connected to the monitor with and interface cable that includes wires for conducting electrical signals.
[0005] An ideal cable and connector assembly for use in such medical devices would be immune to noise interference from external sources as well as crosstalk between wires within the cable and connector assembly. In reality, however, the manufacturing process of a cable and connector assembly includes steps that make the wires within a cable and connector assembly vulnerable to noise, such as capacitive and inductive crosstalk, wherein electrical signals in one wire or pair of wires may interfere or create noise on a nearby wire. The crosstalk may be detrimental to the operation of a medical device. For example, in pulse oximetry, the crosstalk can result in inaccurate readings of SpO 2 values.
[0006] Cables are generally manufactured to limit the amount of external noise and inductive and capacitive crosstalk that can occur between wires. For example, the cables are bundled together with an electrically insulating protective coating and a conductive shield mesh to protect against environmental noise sources. Additionally, the cables may be made up of twisted wire pairs, commonly referred to as twisted pairs. As their name suggests, the twisted pairs are a pair of wires twisted together in a manner that results in each wire becoming exposed to the same or similar amounts noise elements such that the noise can be nearly or completely canceled out. A twisted pair may be surrounded by an electrically grounded conductive mesh shield to help eliminate noise interference from other wires within the cable bundle. Twisted pairs having the conductive mesh shield are referred to as shielded twisted pairs, while twisted pairs without the conductive mesh are referred to as unshielded twisted pairs. The cables used in medical devices such as pulse oximetry systems are commonly constructed with one or both types of twisted pairs, where multiple sets of wires are combined into a cable bundle. Electrical crosstalk can occur when signal wires electrically contact one another (a “short”), or come into close proximity to adjacent conductors.
[0007] In order to connect the wires to connector pins, the cable bundle must be stripped and the wires untwisted. Thus, in this section of the cables, the wires are unprotected and vulnerable to crosstalk interference. Furthermore, after the wires have been connected to connector pins and the pins are placed in a connector housing, even if the wires are initially pushed apart and spatially separated, additional handling and processing may push the wires together and increase the likelihood of crosstalk.
SUMMARY
[0008] Certain aspects commensurate in scope with the originally claimed invention are set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of certain forms the invention might take and that these aspects are not intended to limit the scope of the invention. Indeed, the invention may encompass a variety of aspects that may not be set forth below.
[0009] In accordance with one aspect of the present invention, there is provided a medical device cable. In the examples used herein, the medical device is a pulse oximeter. The pulse oximeter cable comprises a first pair of wires, a second pair of wires and an insulative piece configured to maintain spatial separation between the first and second pairs of wires. Additionally, the cable comprises a connector housing formed over the insulative piece.
[0010] In accordance with another aspect of the present invention, there is provided a method of manufacturing an electrical cable comprising spatially separating a first set of wires from a second set of wires and disposing a device relative to the first and second sets of wires to maintain the spatial separation and coupling pins to the first and second sets of wires. Additionally, the method comprises covering the device with a connector housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Certain exemplary embodiments are described in the following detailed description and in reference to the drawings in which:
[0012] FIG. 1 illustrates an exemplary pulse oximetry system in accordance with an exemplary embodiment of the present invention;
[0013] FIG. 2 illustrates a pulse oximetry cable in accordance with an embodiment of the present invention;
[0014] FIG. 3 illustrates an insulative material with slots through which wires pass in accordance with an exemplary embodiment of the present invention;
[0015] FIG. 4 illustrates an insulative piece between wires in accordance with an alternative exemplary embodiment of the present invention;
[0016] FIG. 5 illustrates an electrically grounded conductive object between wires in accordance with an alternative exemplary embodiment of the present invention;
[0017] FIG. 6 illustrates an insulative block with pads and traces configured to spatially separate wires in accordance with an alternative exemplary embodiment of the present invention;
[0018] FIG. 7 illustrates placing an epoxy material on and in between wires in accordance with an alternative exemplary embodiment of the present invention;
[0019] FIG. 8 illustrates a cross-sectional view of the material of FIG. 7 ;
[0020] FIG. 9 illustrates a printed circuit board configured to spatially separate wires in accordance with an alternative exemplary embodiment of the present invention;
[0021] FIG. 10 illustrates an alternative embodiment for using a printed circuit board in accordance with an alternative exemplary embodiment of the present invention;
[0022] FIG. 11 illustrates top view of the printed circuit board of FIG. 10 ;
[0023] FIG. 12 illustrates a view of the bottom of the printed circuit board of FIG. 10 ; and
[0024] FIG. 13 is a flow chart depicting a technique for reducing crosstalk in accordance with an exemplary embodiment of the present invention.
DETAILED DESCRIPTION
[0025] One or more specific embodiments of the present invention will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
[0026] Turning initially to FIG. 1 , an exemplary medical device, such as a pulse oximetry system, is illustrated and generally designated by the reference numeral 10 . Pulse oximetry systems, such as system 10 , calculate various physiological parameters by detecting electromagnetic radiation (light) that is scattered and absorbed by blood perfused tissue. The pulse oximeter system 10 has a main unit 12 which houses hardware and software configured to calculate various physiological parameters. The main unit 12 has a display 14 for displaying the calculated physiological parameters, such as oxygen saturation or pulse rate, to a caregiver or patient. The pulse oximetry system 10 also has a sensor unit 16 , which may take various forms. As shown in FIG. 1 , the sensor unit 16 may be configured to fit over a digit of a patient or a user. The sensor unit 16 is connected to the main unit 12 via a cable 18 . The cable 18 may be coupled to main unit 12 using a connector housing 20 . It is at the interface between the cable 18 and the pins 34 (shown in FIG. 2 ) of the connector housing 20 where noise interference in the form of crosstalk is most likely to occur.
[0027] A more detailed illustration of the cable 18 is shown in FIG. 2 . Specifically, the cable 18 is shown having an outer jacket 22 . The outer jacket 22 is a polymeric material jacket to hold the cable bundle together and to protect the wires from environmental factors. Under the outer jacket 22 , the cable 18 has an outer shield 24 which may be configured to prevent electromagnetic interference from external sources. The outer shield 24 may be made up any type of shielding material, such as a metallic mesh, for example.
[0028] The cable 18 , as shown in FIG. 2 , has both emitter wires 26 and detector wires 28 . Both the emitter wires 26 and the detector wires 28 are twisted pair wires. The wire pairs are twisted so that each wire is similarly exposed to any potential electromagnetic interference that reaches the wires. Because each of the wires is exposed to similar levels of interference, the interference can be reduced through circuit designs that cancel such common-mode signals.
[0029] The emitter wires 26 may comprise an unshielded twisted pair and the detector wires 28 may comprise a shielded twisted pair. As can be seen in FIG. 2 , the detector wires 28 have a jacket 30 , such as a polymeric coating for example, and an inner shield 32 similar to the outer shield 24 of the cable 18 . The detector wires 28 are shielded electrically to prevent potential crosstalk from the emitter wires 26 , as well as interference from environmental factors. Both the emitter wires 26 and the detector wires 28 are individually connected to respective pins 34 of a connector housing, such as connector housing 20 .
[0030] During the manufacturing process, the outer jacket 22 is stripped from the cable 18 , and the coating 30 of the detector wires 28 is stripped from the detector wires 28 . The emitter wires 26 and detector wires 28 are then untwisted to facilitate connection of the emitter wires 26 and detector wires 28 to their respective pins 34 . The detector wires 28 , however, become vulnerable to a variety of noise-inducing influences, including inductive and capacitive crosstalk from the emitter wires 26 when they are unshielded and untwisted.
[0031] Initially, during the manufacturing process, the emitter wires 26 and the detector wires 28 are separated. The wires may be pulled apart by a worker or a machine may push a tool in between the pairs of wires to separate them. Unfortunately, after this initial separation, little may be done to maintain the separation of the wires.
[0032] Although workers may understand their specific role in the manufacturing process, they may not fully appreciate the importance of maintaining the separation between the wires and may fail to take precautions to maintain the separation of the wires. As such, the cables may be tossed into bins for transportation to different workstations, and the cables may be handled and manipulated by multiple workers and machines before the cables are fully assembled and ready for operation. In the bins, the cables may be compacted together or get tangled together. While being handled and manipulated by workers and machines, the wires may be pushed together. Therefore, at the end of the manufacturing process, there is a risk that the wires will no longer be separated, resulting in an increased susceptibility to crosstalk in the fully assembled cables.
[0033] To address this concern, an insulative material 36 , as illustrated in FIG. 3 , may be used to maintain spatial separation between the emitter wires 26 and detector wires 28 in order to prevent crosstalk. The insulative material 36 may be a silicon rubber, polymer, or other electrically non-conductive material. The insulative material 36 may have apertures 38 , such as slots, through which the emitter wires 26 and detector wires 28 are passed during the manufacturing process. The wires may be coupled to the pins before or after being passed through the apertures 38 . The apertures 38 of the insulative material 36 help ensure that the emitter wires 26 and detector wires 28 remain separated throughout the manufacturing process to prevent crosstalk.
[0034] After the emitter wires 26 and detector wires 28 have been positioned in the apertures 38 , the insulative material 36 and a portion of the pins 34 and the wires 26 and 28 are encapsulated by the connector housing 20 . An over-molding process (such as insert, injection, or transfer molding), or other means, may be implemented to form the connector housing 20 . The connector housing 20 is formed over the insulative piece 36 so that the insulative piece 36 can continue to prevent the emitter and detector wires from moving closer to each other during the encapsulation process. By preserving the spatial separation, the insulative piece 36 helps the detector wires 28 to be less susceptible to crosstalk interference from the emitter wires 26 .
[0035] In another embodiment, as illustrated in FIG. 4 , an insulative piece 40 , such as a piece of silicon rubber, polymer or other electrically non-conductive material, may be wedged or coupled between the emitter wires 26 and detector wires 28 to prevent electrical crosstalk. The insulative piece 40 is wedged or coupled between the emitter wires 26 and detector wires 28 by directing the wires into open ended apertures 42 located on opposite sides of the insulative piece 40 . The insulative piece 40 is installed prior to the encapsulation process and prevents the emitter wires 26 and the detector wires 28 from moving into closer proximity of each other during the encapsulation process or handling prior during the manufacturing process. The encapsulation process forms the connector housing 20 over the insulative piece 40 , as described above.
[0036] Alternatively, as illustrated in FIG. 5 , a conductive object 50 , such as a piece of copper, positioned between the emitter wires 26 and detector wires 28 can help reduce or eliminate crosstalk. The conductive object 50 is electrically grounded via the wire 52 . The wire 52 may be formed by aggregating the wire mesh of the outer shield 24 to form a single wire, or comprise a separate drain or ground wire. The conductive object 50 is positioned between the emitter wires 26 and detector wires 28 . It should be understood that the conductive object 50 may be implemented alone or in conjunction with insulative embodiments described herein. Specifically, for example, the conductive object 50 may be supported by the insulative material 36 of FIG. 3 . The connector housing 20 would then be formed over the both conductive object 50 and the insulative material 36 .
[0037] Turning to FIG. 6 , yet another embodiment includes an insulative piece 60 with solder pads 62 and traces 64 and 66 . The insulative piece 60 may be a resin glass composition, a polymer capable of withstanding the temperatures used in soldering, or other suitable material. As illustrated, the insulative piece 60 has solder pads 62 on one side to connect the emitter wires 26 and detector wires 28 to the insulative piece 60 . The solder pads 62 are connected to electrically conductive traces 64 and 66 that run on the front side and backside of the insulative piece 60 , respectively. Specifically, the traces 64 , which are coupled to the detector wires 28 , run on a front side of the insulative piece 60 , while the traces 66 , which are coupled to the emitter wires 26 , run on a backside of the piece 60 . Thus, the insulative piece 60 spatially separates the emitter traces 26 from the detector traces 28 to prevent crosstalk from occurring. Once the wires and pins are coupled to the insulative piece, the connector housing 20 may be formed over the insulative piece 60 through the encapsulation process.
[0038] Alternatively, an insulative material 70 , such as epoxy resin or silicone, for example, may be used to maintain spatial separation of the detector wires 28 and the emitter wires 26 , as illustrated in FIG. 7 . The material 70 may be placed on and in between the wires 26 and 28 after the external coating has been removed and the wires 26 and 28 have been separated from each other. The material 70 may initially be a two-part gel that cures and hardens as the two parts interact. Once cured, the material 70 holds the wires in place to prevent the wires from coming into proximity of each other during the manufacturing process.
[0039] A cross-sectional view of the material 70 is illustrated in FIG. 8 . As can be seen, the detector wires 28 are spatially separated from the emitter wires 26 . The material 70 has a high dielectric constant to reduce capacitive effects, and, therefore, the emitter wires 26 and the detector wires are spatially and electrically isolated. The connector housing 20 may be formed over the material 70 through the encapsulation process after the material 70 has cured.
[0040] In another embodiment, a printed circuit board (PCB) 72 may also be used to maintain spatial separation between the emitter wires 26 and detector wires 28 , as shown in FIG. 9 . The PCB 72 may be a multi-layer PCB with solder pads or holes (not shown) for coupling the wires to the PCB 72 . The solder pads or holes for coupling the emitter wires 26 to the PCB 72 may be located remotely from the solder pads or holes for coupling the detector wires 28 to the PCB 72 . Vias and traces in and on the PCB 72 connect the emitter wires 26 and detector wires 28 to the proper pins. The connector housing 20 may be formed over the PCB 72 .
[0041] An alternative embodiment using a PCB to prevent crosstalk is shown in FIG. 10 . Specifically, FIG. 10 shows a side view of a PCB 74 positioned between a top layer and a bottom layer of pins 34 . The PCB 74 is a two surface circuit board having traces, pads, and connection points for the connector pins 34 on both surfaces of the PCB 74 . As can be seen by further referring to FIGS. 11 and 12 , the detector contacts 76 a - b are physically remote from the emitter contacts 78 a - b. In addition, the inner shield wire 32 is soldered on the top surface 80 of the PCB 74 while the detector wires 28 are soldered on the bottom surface 82 of the PCB 74 . The location of the detector wires 28 provide spatial separation from the emitter wires 26 . The PCB 74 additionally shields the detector contacts 76 a - b and emitter contacts 78 a - b from the memory chip contacts. The inner shield 32 is routed by trace 84 to a contact pad 90 which may be conductively coupled to a pin 6 (not shown) of a connector. The connector housing 20 may be formed over the PCB 74 . Wires 26 and 28 emanating from cable 18 may be kept short in length to prevent cross-talk. Use of the PCB provides an easier substrate to terminate the wires to during the manufacturing process than terminating the wires to the pins directly.
[0042] Turning to FIG. 13 , a technique to prevent crosstalk in pulse oximetry cables in accordance with an exemplary embodiment of the present invention is illustrated as a flow chart and generally designated by the reference numeral 100 . The technique 100 begins by stripping a cable, as indicated at block 102 . The cable may be any cable used in medical devices, such as those used in pulse oximeters and may include multiple wires which are also stripped. Once stripped, the wires are vulnerable to potential noise-inducing influences, such as crosstalk from the other wires of the cable. Therefore, the stripping of the wires should be performed with the goal of preserving as much of the shield on the wires as possible.
[0043] After the wires are stripped, the wires are spatially separated from each other, as indicated at block 104 . Specifically, sets of twisted pairs are separated from each other. The spatial separation of the wires may be done by a person or by a machine. Because the twisting of the wires is a noise cancellation technique, effort should be made to keep the pairs of wires twisted, insofar as it is practicable.
[0044] The spatial separation between the sets of wires is maintained by coupling or inserting a device between the sets of wires, as indicated at block 106 . Specifically, the spatial separation may be maintained by implementing one of the embodiments described above, such as using a PCB to physically separate the emitter wires 26 from the detector wires 28 , for example, or inserting an insulative object between the pairs of wires. The use of one of the above mentioned exemplary embodiments, or other device, precludes the pushing of the separated wires into closer proximity of each other during the over-molding process or other processing and handling that may occur during manufacture.
[0045] Connector pins are electrically coupled to the wires, as indicated by block 108 . The connector pins may be connected to the wires either directly by soldering the wires to the pins or indirectly via traces on a PCB, as described above, depending on the particular embodiment being implemented. By physically separating the wires and preserving that separation, crosstalk between wires is greatly reduced, or eliminated. The elimination of crosstalk may increase the accuracy of the medical devices.
[0046] The techniques described herein for maintaining spatial separation of the signal wires during the cable termination process to reduce cross-talk have applicability in patient monitoring applications beyond pulse oximetry. With respect to devices that utilize photo-emitters and photo-detectors as described herein, such techniques can be utilized in devices intended to monitor other blood constituents such as carboxyhemoglobin, methemoglobin, total hemoglobin content, glucose, pH, water content and others. Reducing signal cross-talk is also of importance in bio-impedance measurements for evaluating physiologic variables such as tissue hydration, cardiac output or blood pressure.
[0047] The step of creating a cabling connector may not be restricted to over-molding processes. Pre-molded connector housing components may be assembled to contain the pins and cable. During assembly, wires may come into close proximity that results in cross-talk (noise). The techniques described above may be used to reduce the likelihood of this occurring by ensuring proper spatial separation during the assembly process.
[0048] Additionally, it should be understood, that although the figures and the associated discussion describe embodiments wherein the cable 18 comprises twisted pair wires, the techniques disclosed herein may be applicable to any type of cable. Indeed, the techniques disclosed herein may be implemented with a coaxial cable, for example.
[0049] While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.
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A device and method for reducing crosstalk between wires is provided. The method includes spatially separating first and second sets of wires. A device is disposed relative to the first and second sets of wires to maintain the spatial separation. The method also comprises coupling pins to the first and second sets of wires. Additionally, the method includes covering the device with a connector housing.
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CLAIM OF PRIORITY
This application makes reference to, incorporates the disclosure of, and claims all benefits accruing under 35 U.S.C. §119 from an application entitled IMAGE SIGNAL PROCESSING SYSTEM WHICH USES A PORTABLE COMPUTER MONITOR AS A DISPLAY earlier filed in the Korean Industrial Property Office on Sep. 20, 1996, and duly assigned Ser. No. 96-41161.
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to an image signal processing device which uses a portable computer monitor as a display, and, more particularly, to an image signal processing system which processes television signals or external image signals and displays the same using a portable computer monitor such as a liquid-crystal display(LCD).
2. Related Art
The prior art in the area of liquid crystal television displays and/or receivers is represented by the following patents: U.S. Pat. No. 4,652,932 to Miyajima et al., entitled Liquid Crystal Display Television Receiver; U.S. Pat. No. 4,809,078 to Yabe et al., entitled Liquid Crystal Television Receiver; U.S. Pat. No. 4,982,275 to Brody, entitled Modular Flat-Screen Color Television Displays And Modules And Circuit Drives Therefor; and U.S. Pat. No. 5,119,204 to Hashimoto et al., entitled Liquid Crystal Television Set Having Driving Circuit On Peripheral Portion And Method Of Fabrication Of Image Display Section. However, for the reasons stated below, the invention disclosed herein has advantages over the prior art, and is thus distinguishable therefrom.
However, such dedicated or single function television displays and/or receivers have had a cost disadvantage in that and pays a relative large price for the single function of television program display.
In the meantime, computers have become increasingly commonplace. More recently, as a result of changing lifestyles and work patterns, there has been a rise in the use of portable computers That is, many people desire and require mobility when using their computers.
In addition, the development of computers has taken a “multimedia” direction in which a single computer has the potential for containing a variety of functions which enable the computer to be used for many different tasks. Through this multimedia development, computers are not limited by location or distance and can handle an assortment of office and leisure-related tasks.
In order to allow the computer to contain all these functions, development in the computer itself is, of course, very important. Equally important and crucial for the performance of some functions, however, are advancements made with regard to the monitor.
Monitors for portable computers now use TFT LCDs and other such displays that offer excellent display quality. It is, therefore, now possible to mount a television reception device inside the portable computer and watch television.
If the user desires television-viewing capabilities, a television reception device must be mounted inside the main body of the portable computer. But the addition of a TV reception device increases the weight of the portable computer. Further, programs used for the viewing of television are complicated and require that many adjustments be made. This is burdensome for the user acquainted with computers and complex for the novice.
As a result, there is a need for a device which allows the user to watch television using a monitor of a portable computer such that the weight of the portable computer is not increased, and the operation of viewing television is simple. Specifically, there is a need for a device which provides the advantages of a single-function, image signal processing device (i.e., simplicity) and which precludes the installation of television receiving circuitry in the portable computer (thereby increasing its weight) while at the same time allowing the use of a portable computer monitor with the image signal processing device, thereby achieving economy and the further advantages associated wide use of a high quality portable computer monitor.
SUMMARY OF THE INVENTION
The present invention has been developed in an effort to fill the above need.
It is an object of the present invention to provide an image signal processing system which is structured so as to enable the use of a portable computer monitor, such that the weight of a portable computer is not increased, and the viewing of television is easy. To achieve the above object, the present invention provides an image signal processing system which uses a display removed from a portable computer. The system includes a housing containing an image signal processing device for receiving, converting and outputting image signal data. The housing is provided with attachment members for physically attaching the display removed from the portable computer to the image signal processing device, and the image signal processing device is provided with means for electrically connecting the device to the display so as to transmit the image signal to the display.
The body is further provided with a battery receptor into which a battery used for portable computers can be inserted.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein:
FIG. 1 is an exploded perspective view of an image signal processing system which uses a portable computer monitor according to an embodiment of the present invention;
FIG. 2 is an exploded perspective view of the prior art portable computer with detachable monitor;
FIG. 3 is a perspective view of an image signal processing system in a state in which the prior art monitor is attached thereon;
FIG. 4 is a block diagram of the image signal input device according to a preferred embodiment of the present invention; and
FIG. 5 is an exploded perspective view of an image signal processing system which uses a portable computer monitor according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
As shown in FIG. 1, there is shown an image signal processing system 300 which uses a portable computer monitor 100 . The image signal processing system 300 includes a television reception device 320 for receiving an input of television signals, for modulating and demodulating the signals, for converting the signals to allow for display, and for outputting the signals; a control portion 360 , which allows a user to control the image signal processing system 300 ; speakers 350 mounted in the image signal processing system 300 ; an antenna 400 for receiving television signals such that they can be provided to the television reception device 320 ; an antenna holder 410 , into which the antenna 400 can be folded when the image signal processing system is not in use; attachment members 380 to which the monitor 100 is joined; a data cable 370 , which transmits data from the television reception device 320 to the monitor 100 ; and a battery receptor 390 .
The monitor 100 , used from a portable computer, includes a liquid crystal display(LCD) 110 which displays television data transmitted from the television reception device 320 , a connecting portion 150 into which the data cable 370 is inserted to electronically connect the LCD 110 and the television reception device 320 , a back case 120 and a front case 130 which cover and protect the LCD 110 , and connecting means 140 , which mechanically connects the LCD 110 to the image signal processing system 300 . Also, a battery 210 from a portable computer is placed in the battery receptor 390 of the image signal processing system 300 , the battery 210 supplying electrical power to the image signal processing system 300 and the LCD 110 .
FIG. 2 illustrates the monitor 100 in a state detached from a conventional portable computer. As shown in the drawing, a main body 10 of the portable computer includes pc attachment members 20 and a pc data cable 30 . The connecting members 140 of the monitor 100 are disconnected from the pc attachment members 20 , and, at the same time, the pc data cable 30 is disconnected from the connecting portion 150 of the monitor 100 . As a result, the monitor 100 can be used in the image signal processing system 300 of the present invention.
FIG. 3 illustrates the image signal processing system 300 and the monitor 100 in an assembled state.
Referring now to FIG. 4, there is shown a block diagram of the image signal processing system according to a preferred embodiment of the present invention. As shown in the diagram, there is provided an electrical power portion 200 , which controls the electricity for all the devices in the image signal processing system 300 ; a tuner 330 , which performs detection and tuning functions relative to television signals inputted from the antenna 400 and outputs the latter signals; an image/sound signal converter 315 , which converts the signals outputted from the tuner 330 into image and sound signals; a liquid crystal converter 310 , which converts the image signals provided by the image/sound signal converter 315 into liquid crystal display signals that can be provided to the liquid crystal display 110 for display; speakers 350 responsive to the sound signals received from the converter 315 for producing actual sounds; and an external image input terminal 340 , which is a conventional terminal for directly receiving image signals from an external reception device, rather than through the tuner 330 .
The electrical power portion 200 further comprises: the battery 210 ; an adaptor connecting jack 230 which interfaces with a conventional adaptor from a portable computer so as to apply electrical power to the image signal processing system 300 ; and an electrical power control portion 220 which receives external power or power from the battery 210 and controls the power supplied to all the components of the image signal processing system 300 .
In the present invention, although a liquid crystal converter 310 is disclosed, it is possible to use other such converters to make the image signal processing system 300 compatible with the portable computer monitor 100 .
The following is an explanation of the operation of the image signal processing system 300 according to a preferred embodiment of the present invention.
First, the monitor 100 (FIG. 1) from a portable computer is removed and the connecting members 140 and connecting portion 150 of the monitor 100 are connected to the attachment members 380 and data cable 370 , respectively, of the image signal processing system 300 . Next, the battery 210 from the portable computer is inserted in the battery receptor 390 or an adaptor is connected to the adaptor connecting jack 230 (FIG. 4 ).
When electrical power is supplied, the image signal processing system 300 receives television signals through the antenna 400 which provides these signals to the tuner 330 (see FIGS. 1 and 4 ).
The tuner 330 detects and tunes frequency television signals corresponding to the received television signals, and outputs these signals in correspondence to the system used in the particular district. Namely, the signals are outputted in one of the following methods: NTSC (National Television System Committee), PAL (Phase Alternation by Line), or SECAM (Sequence de Killers Avec Memoire).
The image/sound signal converter 315 receives the above signals and converts them into image signals. These image signals are then inputted to a liquid crystal converter 310 for further conversion into signals that can be used in the LCD 110 of monitor 100 .
After these signals are converted in the liquid crystal converter 310 , they are outputted to the LCD 110 , allowing for the display of images on a screen according to the received television signals
Signals can also be received directly by the external image input terminal 340 of FIG. 4, bypassing the tuner 330 . After the reception of the signals by the external image input terminal 340 , the signals are then transmitted to the image/sound signal converter 315 , and then the same process as described above is followed. That is, the signals are received by the image/sound signal converter 315 , are converted and outputted as image signals to the liquid crystal converter 310 , and are then converted and outputted to the LCD 110 which, in turn, displays the corresponding images on monitor 100 .
Referring to FIG. 5, in the system, the speaker 350 and the control portion 360 can be mounted on the front side of the system 300 . On the upper side of the system, a display mounting groove 411 is formed such that the display 100 can be pivotally mounted.
By using the image signal processing system of the present invention, a portable computer monitor can be used as the screen such that a television reception device need not be installed in the portable computer. Thus, an increase in the weight of the computer is avoided, and the watching of television is made easy by eliminating the need to run complicated computer programs.
While this invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
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An image signal processing system uses a display removed from a portable computer, and includes a housing containing an image signal processing system for receiving and converting image signals to provide image signal data, wherein the housing is provided with a fixing member for fixing the display removed from the portable computer, and the image signal processing system is provided with a connector for electrically connecting the system to the display so as to transmit the image signal to the display.
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FIELD OF THE INVENTION
[0001] The present invention relates to the field of air conditioner controlling technologies, and in particular, to a customized control method and system for air conditioner operation mode.
BACKGROUND OF THE INVENTION
[0002] Currently, with the rapid development of touch screen technologies, touch displays have already been applied in terminal devices such as mobile phones, tablet personal computers, on a large scale, and touch displays have also been applied in home appliances (such as, air conditioner) gradually. Middle-grade or high-grade air conditioner already has big touch screens, user can directly operate virtual keys or menus on the touch screen of the air conditioner to operate the air conditioner directly. With the rapid development of internet of things and radio frequency techniques, when users install control software of air conditioners in the terminal devices such as the mobile phones, users can also control the air conditioner through the virtual keys or menus on the touch screen of the mobile phone.
[0003] However, the operation mode of the air conditioner is normally designed by the factory, such as meeting mode, office mode, reading mode, and so on, the operation mode cannot be customized according to personal needs, such as whether a wind guiding angle faces the human body or avoid the human body, whether wind sweep, the size of wind sweeping range, how the temperature is set, the setting of the parameters of the sleeping curve, and so on. When a user uses the air conditioner, a plurality of operation parameters of the air conditioner should be commonly adjusted to satisfy the using needs, so that, when somebody else use the air conditioner, they should adjust the operation parameters again to satisfy the using needs of themselves, the operation is complicated, time-consuming and easy to get wrong.
SUMMARY OF THE INVENTION
[0004] The main aim of the present disclosure is that the operation parameters of the air conditioner are preset differently according to different users, and a key to operate the mapping relation between the operation parameters of the air conditioner and the virtual keys is realized, a convenience and an accuracy of the operation of the air conditioner are improved.
[0005] In order to realize the aim, the present disclosure provides a customized control method for an air conditioner operation mode, which includes: a control terminal or the air conditioner provides a customized setting interface for operation mode for a user to customize operation parameters of the air conditioner when the control terminal or the air conditioner receives a customized setting command for the air conditioner operation mode sent out by the user; the control terminal or the air conditioner generates and displays a virtual key according to a customized operational parameter when the user finishes the customized setting of the operation mode based on the customized setting interface of operation mode; when the control terminal receives a trigger command for the virtual key caused by user, the control terminal controls the air conditioner according to the operation parameters corresponding to the generated virtual key, or, when the air conditioner receives the trigger command for the virtual key caused by user, the air conditioner operates according to the operation parameters corresponding to the generated virtual key.
[0006] Preferably, the method further includes: when the control terminal or the air conditioner receives a customized modification command for air conditioner operation mode sent out by user corresponding to the existed virtual key, the control terminal or the air conditioner provides a customized modification interface for operation mode for user to customize operation parameters of the air conditioner corresponding to the existed virtual key
[0007] Preferably, the method further includes: when the control terminal or the air conditioner receives a customized deleting command for the existed virtual key sent out by user, the control terminal or the air conditioner supports a customized deleting interface for operation mode for user to customized delete the existed virtual key and operation parameters corresponding to the existed virtual key.
[0008] Preferably, the method further includes: when the control terminal receives a trigger command from the virtual key caused by the user, the control terminal controls the operation of the air conditioner according to the operation parameters corresponding to the existed virtual key; or, when the air conditioner receives the trigger command from the virtual key caused by the user, the air conditioner operates according to the operation parameters corresponding to the existed virtual key.
[0009] In addition, in order to realize the aim, the present disclosure also provides a customized control method for an air conditioner operation mode, which includes: when a virtual key adding command sent by a user is received, the control terminal or the air conditioner generates and displays a virtual key, an operation parameter of the virtual key to be set customarily; when a customized setting command for the air conditioner operation mode sent out by the user and corresponding to the generated virtual key is received, the control terminal or the air conditioner provides a customized setting interface for operation mode for a user to customize operation parameters of the air conditioner; when the user finishes the customized of the operation parameters based on the customized setting interface for operation mode, the control terminal or the air conditioner sets up a mapping relation between the customized operation parameter and the generated virtual key; when a trigger command of the virtual key caused by user is received, the control terminal controls the air conditioner according to the operation parameters corresponding to the generated virtual key, or, when the air conditioner receives the trigger command of the virtual key caused by user, the air conditioner operates according to the operation parameters corresponding to the generated virtual key
[0010] Preferably, the method further includes: when the control terminal or the air conditioner receives a customized modification command for air conditioner operation mode sent out by user corresponding to the existed virtual key, the control terminal or the air conditioner provides a customized modification interface for operation mode for user to customize operation parameters of the air conditioner corresponding to the existed virtual key.
[0011] Preferably, the method further includes: when the control terminal or the air conditioner receives a customized deleting command for the existed virtual key sent out by user, the control terminal or the air conditioner supports a customized deleting interface for operation mode for user to customized delete the existed virtual key and operation parameters corresponding to the existed virtual key.
[0012] Preferably, the method further includes: when the control terminal receives a trigger command from the virtual key caused by the user, the control terminal controls the operation of the air conditioner according to the operation parameters corresponding to the existed virtual key; or, when the air conditioner receives the trigger command from the virtual key caused by the user, the air conditioner operates according to the operation parameters corresponding to the existed virtual key.
[0013] In addition, in order to realize the aim, the present disclosure further provides a customized control system for an air conditioner operation mode, the customized control system for an air conditioner operation mode is run on a control terminal or the air conditioner, customized control system for an air conditioner operation mode includes:
[0014] a mode customized module, which is used for providing a customized setting interface for operation mode for a user to customize operation parameters of the air conditioner when a customized setting command for the air conditioner operation mode sent out by the user is received; and generating and displaying a virtual key according to the customized operational parameter when the user finishes the customized setting of the operation mode based on the customized setting interface of operation mode;
[0015] a customized mode excitation module, when the control terminal receives a trigger command from the virtual key caused by the user, the customized mode excitation module controls the operation of the air conditioner according to the operation parameters corresponding to the existed virtual key; or, when the air conditioner receives the trigger command from the virtual key caused by the user, the customized mode excitation module operates according to the operation parameters corresponding to the existed virtual key.
[0016] Preferably, the mode customized module is also used for that: when a customized modification command for air conditioner operation mode sent out by user corresponding to the existed virtual key is received, the mode customized module provides a customized modification interface for operation mode for user to customize operation parameters of the air conditioner corresponding to the existed virtual key.
[0017] Preferably, the mode customized module is also used for that: when a customized deleting command for the existed virtual key sent out by user is received, the mode customized module supports a customized deleting interface for operation mode for user to customized delete the existed virtual key and operation parameters corresponding to the existed virtual key.
[0018] Preferably, the customized mode excitation module is also used for that: when the control terminal receives a trigger command from the virtual key caused by the user, the customized mode excitation module controls the operation of the air conditioner according to the operation parameters corresponding to the existed virtual key; or, when the air conditioner receives the trigger command from the virtual key caused by the user, the customized mode excitation module operates according to the operation parameters corresponding to the existed virtual key.
[0019] In addition, in order to realize the aim, the present disclosure further a customized control system for an air conditioner operation mode, the customized control system for an air conditioner operation mode is run on a control terminal or the air conditioner, the customized control system for an air conditioner operation mode includes:
[0020] a mode customized module, which is used for that when a virtual key adding command sent by a user is received, the mode customized module generates and displays a virtual key, an operation parameter of the virtual key need to be set customarily; a customized setting command for the air conditioner operation mode sent out by the user and corresponding to the generated virtual key is received, the control terminal or the air conditioner provides a customized setting interface for operation mode for a user to customize operation parameters of the air conditioner; when the user finishes the customized of the operation parameters based on the customized setting interface for operation mode, the control terminal or the air conditioner sets up a mapping relation between the customized operation parameter and the generated virtual key;
[0021] a customized mode excitation module, which is used for that when a trigger command of the virtual key caused by user is received, the control terminal controls the air conditioner according to the operation parameters corresponding to the generated virtual key, or, when the air conditioner receives the trigger command of the virtual key caused by user, the air conditioner operates according to the operation parameters corresponding to the generated virtual key.
[0022] Preferably, the mode customized module is also used for that: when a customized modification command for air conditioner operation mode sent out by user corresponding to the existed virtual key is received, the mode customized module provides a customized modification interface for operation mode for user to customize operation parameters of the air conditioner corresponding to the existed virtual key.
[0023] Preferably, the mode customized module is also used for that: when a customized deleting command for the existed virtual key sent out by user is received, the mode customized module supports a customized deleting interface for operation mode for user to customized delete the existed virtual key and operation parameters corresponding to the existed virtual key.
[0024] Preferably, the customized mode excitation module is also used for that: when the control terminal receives a trigger command from the virtual key caused by the user, the customized mode excitation module controls the operation of the air conditioner according to the operation parameters corresponding to the existed virtual key; or, when the air conditioner receives the trigger command from the virtual key caused by the user, the customized mode excitation module operates according to the operation parameters corresponding to the existed virtual key.
[0025] Compared with the traditional technology, when the customized setting command for air conditioner operation mode is received, the present disclosure provides the customized setting interface for air conditioner operation mode for user to customize the operation parameters of the air conditioner, and maps the customized operation parameters with the virtual keys, so that the operation parameters of the air conditioner can be differently preset according to different users, and one key to operate can be realized by mapping the operation parameters of the air conditioner with the virtual keys, the convenience and the accuracy of the operation of the air conditioner are improved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a hardware structure diagram of a control terminal realizing a customized control for an air conditioner operation mode according to a preferable embodiment.
[0027] FIG. 2 is a system architecture diagram of the touch screen display system shown in FIG. 1 .
[0028] FIG. 3 is a functional block diagram of the customized control system for air conditioner operation mode shown in FIG. 1 according to a preferable exemplary embodiment.
[0029] FIGS. 4-14 are customized setting interfaces provided by the customized control system for air conditioner operation mode shown in FIG. 1 .
[0030] FIG. 15 is a hardware structure diagram of the air conditioner realizing the customized control for air conditioner operation mode according to a preferable exemplary embodiment of the present disclosure.
[0031] FIG. 16 is a system frame diagram of the touch screen display system shown in FIG. 15 .
[0032] FIG. 17 is a functional block diagram of the customized control system for air conditioner operation mode shown in FIG. 15 according to a preferable exemplary embodiment.
[0033] FIG. 18 is a specific flow diagram of the customized control method for air conditioner operation mode according to a first exemplary embodiment.
[0034] FIG. 19 is a specific flow diagram of the customized control method for air conditioner operation mode according to a second exemplary embodiment.
[0035] The realizing of the aim, functional characteristics, and advantages of the present disclosure are further described in detail with reference to the accompanying drawings and the embodiments.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0036] It is to be understood that, the described embodiments are only some exemplary embodiments of the present invention, and the present invention is not limited to such embodiments.
[0037] As shown in FIG. 1 , FIG. 1 is a hardware structure diagram of a control terminal realizing a customized control for an air conditioner operation mode according to a preferable embodiment. The control terminal 1 includes a processing unit 10 , a memory unit 15 , a wireless signal transmitting unit 13 , a touch screen display system 16 and a customized control system for air conditioner operation mode 11 . The control terminal 1 can be a mobile phone, a tablet personal computer, a computer or other any applicable electronic devices (preferably, the mobile phone).
[0038] The touch screen display system 16 can be used for providing a human-computer interface for user to input commands, and output and display response data for a user command caused by the control terminal 1 . In the exemplary embodiment, the human-computer interface includes, but not limited to, a customized setting interface for air conditioner operation mode.
[0039] As shown in FIG. 2 , FIG. 2 is a system architecture diagram of the touch screen display system 16 shown in FIG. 1 . The touch screen display system 16 includes a touch detecting device 160 , a touch screen controller 161 and a display unit 162 . The display unit 162 can be used for displaying information content; the touch detecting device 160 and the touch screen controller 161 can be used for user to proceed touch operation by the touch screen display system 16 . Whereby, the touch detecting device 160 can be used for detecting a touch position of user and transfer the detected information to the touch screen controller 161 ; the touch screen controller 161 receives the touch position information from the touch detecting device 160 , and converts the received touch position information into contact coordinate information, transfers the converted contact coordinate information to the processing unit 10 , and receives executive commands sent from the processing unit 10 and executes.
[0040] In another exemplary embodiment of the present disclosure, the screen display system 16 can also be any other applicable display systems having the touch function.
[0041] The memory unit 15 can be used for storing the customized control system for air conditioner operation mode 11 and operation data of the customized control system for air conditioner operation mode 11 . It is to be noted that, the memory unit 15 can be either a separated memory device, or a general term of a plurality of different memory devices, no need to repeat herein.
[0042] The wireless signal transmitting unit 13 can be used for sending out a control signal corresponding to the operating parameter of the user customized operation mode to the air conditioner 2 under the controlling of the processing unit 10 , the wireless signal transmitting unit 13 can be a WIFI module, an infrared signal transmission unit, a Bluetooth module, a wireless signal emitter having a transmitting antenna or any other applicable wireless signal transmitting units (the present disclosure prefers the infrared signal transmission unit).
[0043] The processing unit 10 can be used for calling and executing the customized control system for air conditioner operation mode 11 , so that, under the operation of user, the processing unit 10 provides customized setting interfaces of air conditioner operation mode (such as, the interfaces shown in FIGS. 4-14 ) for user to customize the operation parameters of the air conditioner, generates and displays a virtual key corresponding to the customized operation parameters, when a trigger command of the virtual key caused by the user is received (such as, a click command), the wireless signal transmitting unit 13 is controlled to send out a control signal to the conditioner according to the operation parameters corresponding to the virtual key, the operation control of the conditioner can be realized. The processing unit 10 and the memory unit 15 can be a separate unit respectively, or integrated with each other to form a controller, no need to repeat herein.
[0044] In the exemplary embodiment, the operation parameters include a temperature parameter, a humidity parameter, a blowing direction parameter, a sleeping temperature curve parameter and an operation time parameter. In another exemplary embodiment, the operation parameters include the temperature parameter, the humidity parameter, the blowing direction parameter, the sleeping temperature curve parameter, the operation time parameter and/or any other applicable operation parameters (such as a display luminosity curve of the air conditioner, a display color parameter of the air conditioner, and so on).
[0045] In the exemplary embodiment, the customized setting interface of the operation mode includes a control interface of the conditioner (such as, the interface shown in FIG. 4 ), operation interfaces of adding the virtual keys (such as, the interfaces shown in FIGS. 5-13 ), operation interfaces of modifying the virtual keys (such as, the interfaces shown in FIGS. 5-13 ), an operation interface of deleting the virtual keys (such as, the interface shown in FIG. 14 ), a setting/modification interface for selecting temperature parameter (such as, the interface shown in FIG. 6 ), a setting/modification interface for selecting humidity parameter (such as, the interface shown in FIG. 6 ), a setting/modification operation interface for selecting operation time (such as, the interface shown in FIG. 13 ), setting/modification interfaces for selecting blowing direction parameter (such as, the interfaces shown in FIGS. 7-10 ), setting/modification operation interfaces for selecting sleeping temperature curve parameter (such as, the interfaces shown in FIGS. 11-12 ). In another exemplary embodiment, the customized setting interfaces of the operation mode include any applicable setting interfaces, such as, when the control terminal 1 can control a plurality of conditioners, in a preferable exemplary embodiment, preferably include one interface which can be used for selecting a plurality of conditioners, no need to repeat herein.
[0046] That is, one of an ordinary skill in the art should knows that: the parameter types included in the operation parameters cannot limit inventive ideas of the present disclosure; the interface types and forms included in the customized setting interfaces of the operation mode cannot limit the inventive ideas of the present disclosure.
[0047] As shown in FIG. 3 , FIG. 3 is a functional block diagram of the customized control system for air conditioner operation mode according to a preferred exemplary embodiment.
[0048] It is to be noted that, for an ordinary skill in the art, the functional block diagram of FIG. 3 is just a sample diagram of a preferred exemplary embodiment, ordinary skills in the art around the functional blocks of the customized control system of air conditioner operation mode 11 shown in the FIG. 3 can add new functional blocks easily; the name of each functional block is a customized name, only used for understanding each application functional block of the customized control system of air conditioner operation mode 11 , and cannot limit the technical solutions of the present disclosure, the core of the technical solutions of the present disclosure is that, the function which each function block having the custom name is aim to achieve.
[0049] The customized control system of air conditioner operation mode 11 includes a mode customized module 110 and a customized mode excitation module 112 . The functions of each function module of the customized control system of air conditioner operation mode 11 can be:
Embodiment 1
[0050] The mode customized module 110 can be used for providing customized setting interface of operation mode for user to customize operation parameters of the air conditioner, when the mode customized module 110 receives a customized setting command for air conditioner operation mode sent by user. Embodiment 1, the mode customized module 110 provides customized adding icons/keys of operation mode, when user uses the icons/keys (such as, “+mode” virtual key in the virtual keys area of operation mode 30 ) to do a preset mode operation (such as, click or double clicks), which determines that user sends out a customized adding command for the air conditioner operation mode; embodiment 2, when the mode customized module 110 detects that user does a touch operation of a preset touch path, which determines that user sends out a customized setting command for air conditioner operation mode.
[0051] The mode customized module 110 can also be used for generating and displaying virtual keys according to the customized operational parameters, when user finishes customizing the operation mode based on the customized setting interface of operation mode.
[0052] It is to be understood that, in the first exemplary embodiment, the mode customized module 110 not only supports the above virtual keys adding function, but also supports a modification function for parameters corresponding to the existed virtual keys, and a deleting function for the existed virtual keys.
[0053] When the customized adding command of air conditioner operation mode sent out by user is received (such as, a command sent by clicking “+mode” virtual key in the virtual keys area of operation mode shown in FIG. 4 is received), the mode customized module 110 provides an interface as shown in FIG. 5 first (based on the interface, user can sets names of virtual cases corresponding to the operation mode needed to be customized, such as “wangwu mode” as shown in FIG. 5 ); when user selects and clicks a “temperature setting” key or a “humidity setting” key based on the interface shown in FIG. 5 , the mode customized module 110 provides an interface shown as FIG. 6 ; when user selects and clicks a “sweeping horizontally” key based on the interface shown in FIG. 5 , the mode customized module 110 provides interfaces shown as FIGS. 7-8 ; when user selects and clicks a “sweeping horizontally and orientationally” key based on the interface shown in FIG. 5 , the mode customized module 110 provides an interface shown as FIG. 9 ; when user selects and clicks a “sweeping vertically” key based on the interface shown in FIG. 5 , the mode customized module 110 provides an interface shown as FIG. 10 ; when user selects and clicks a “sleeping curve” key based on the interface shown in FIG. 5 , the mode customized module 110 provides an interface shown as FIG. 11 or FIG. 12 (if the interface shown as FIG. 11 is provided, a new interface for setting temperature curve pops up; if the interface shown as FIG. 12 is provided, the original interface displays the interface for setting temperature curve); when user selects and clicks an “operation time setting” key based on the interface shown in FIG. 5 , the mode customized module 110 provides interfaces shown as FIG. 13 .
[0054] The interface shown in FIG. 6 includes a movably touch-bar 31 , temperature/humidity setting value can be adjusted through moving and touching the movably touch-bar 31 , such as, moving toward “+” symbol can gradually add the temperature/humidity setting value according to a preset magnitude, moving toward “−” symbol can gradually reduce the temperature/humidity setting value according to a preset magnitude.
[0055] The interface shown in FIG. 7 includes a sweeping control identifier 32 , a sweeping horizontally area can be adjusted through moving and touching a threshold value control line S and/or E of the sweeping control identifier 32 (that is, a preset sweeping area can be defined as a area between the control line S and the control line E). When user moves and touches the control line of the sweeping control identifier 32 , a sweeping angle β of the threshold value control line can be dynamically displayed (such as, shown as FIG. 8 ).
[0056] The interface shown in FIG. 9 includes the sweeping control identifier 32 , a direction of the sweeping horizontally and orientationally can be adjusted by sliding a horizontal directional control line of the sweeping control identifier 32 .
[0057] The interface shown in FIG. 10 is similar with the interface shown in FIG. 7 , an operation mode of the interface shown in FIG. 10 is similar with an operation mode of the interface shown in FIG. 7 , no needed to repeat herein.
[0058] In the interface shown in FIG. 11 or FIG. 12 , curve parameters can be changed by moving and touching curves in a temperature-time coordinate.
[0059] Furthermore, in the interface shown in FIGS. 5-10 , a “parameter adding key” (not shown) can be provided, a new parameter setting key can be added in the interface through clicking the “parameter adding key”, a parameter type of the added new parameter setting key can be the same with parameter types of the existed parameter setting keys, the parameter type of the added new parameter setting key can be different from the parameter types of the existed parameter setting keys, no need to repeat herein.
[0060] When user uses the existed icons/keys (such as, the existed virtual key “zhangsan mode” or “lisi mode” in the virtual keys area of operation mode 30 shown in FIG. 4 ) to do an operation of preset type (such as, click or double-clicks), the mode customized module 100 determines that user sends out a customized modification command of air conditioner operation mode; or, when the mode customized module 100 detects that user does the touching operation of preset touch path, the mode customized module 100 determines that user sends out the customized modification command of air conditioner operation mode. It is to be understood that, the customized modification interface of the existed virtual keys can be similar or same with the above customized adding interface, no need to repeat herein.
[0061] When the customized deleting command of air conditioner operation (such as, a command sent out by clicking “−mode” virtual key in the virtual keys area of operation mode 30 shown in FIG. 4 ) sent out by user is received, the mode customized module 100 provides the interface shown in FIG. 14 first, user can select to delete the existed operation mode (such as, “zhangsan mode”, “lisi mode”, “wangerma mode”, “zhangqian mode” and/or “sunli mode”) based on the interface shown in FIG. 14 , “zhangsan mode” is selected in FIG. 14 as a example, when user clicks a “deleting key”, the existed “zhangsan mode” virtual key and operation parameters corresponding to the “zhangsan mode” virtual key are deleted.
[0062] It is to be understood that, the mode customized module 100 can also determine process types needed to be handled through another methods (such as, adding virtual key, modifying virtual key, deleting virtual key), and provides corresponding operation interfaces based on the determined process types. Such as, a mapping relation between the process types and the operation types can be preset (such as, “adding virtual key” corresponds to clicking the icon, “modifying virtual key” corresponds to double clicking the icon, “deleting virtual key” corresponds to long pressing the icon (such as, pressing the icon more than three seconds)), when user does the operation type (such as, click, double-click, long press) to a specific icon, the mode customized module 110 determines that user sends out a corresponding process type; or, a mapping relation between the process types and the preset touch path is preset, when detects that user does the touch operation of the preset touch path, the mode customized module 110 determines that user sends out the corresponding process types.
[0063] The customized mode excitation module 112 is used for controlling the air conditioner according to the operation parameters corresponding to the virtual key when the customized mode excitation module 112 receives a trigger command of the virtual key caused by user (such as, a virtual key named “zhangsan mode”).
Embodiment 2
[0064] The mode customized module 110 can be used for generating and displaying the virtual key that its operation parameter needs to be customized (such as, the virtual key is generated, default-generated name of the virtual key and icon of the virtual key can be a preset name and key icon respectively, or a name modifying command from user can be responded to modify the default-generated name and key icon, such as, the name is modified to “wangwu mode”) when receives the adding command of the virtual key sent out by user, when the customized setting command for air conditioner operation mode corresponding to the virtual key sent by user is received (such as the virtual key named “wangwu mode), customized setting interface is provided for user to customize operation parameters of air conditioner. Embodiment 1, the mode customized module 110 provides customized adding icon/key of operation mode, when user does an operation of preset type (such as, click or double-clicks) to the icon/key (such as, the “+mode” virtual key in the virtual keys area of operation mode 30 ), the mode customized module 110 determines that user sends out the customized adding command for air conditioner operation mode; embodiment 2, when the mode customized module 110 detects that user does the touch operation of the preset touch path, the mode customized module 110 determines that user sends out the customized setting command for air conditioner operation mode.
[0065] The mode customized module 110 can also be used for setting up the mapping relation between the customized operation parameter and the virtual key when the customized setting of the operation mode is finished by user based on customized setting interface of the operation mode.
[0066] The customized mode excitation module 112 can be used for controlling the operation of the air conditioner according to the operation parameters corresponding to the virtual key when the trigger command of the virtual key (such as the virtual key named “wangwu mode”) caused by the user is received.
[0067] It is to be understood that, in the second exemplary embodiment, the mode customized module 110 not only supports the adding function of virtual key, but also supports the modification function of modifying the parameters corresponding to the existed virtual key, and the deleting function of deleting the existed virtual key. Such as, when the mode customized module 120 receives the customized adding command for the air conditioner operation mode corresponding to the existed virtual key (such as virtual key named “lisi mode”) sent out by user, the mode customized module 110 provides a customized modifying interface of the operation mode (such as, interfaces shown in FIGS. 5-13 ) for user to customize operation parameters of the air conditioner; when the mode customized module 110 receives the deleting command of the existed virtual keys sent out by user, the mode customized module 110 provides a customized deleting interface of the operation mode (such as, the interface shown in FIG. 14 ) for user to delete the existed virtual keys and corresponding operation parameters (such as, the virtual key named “lisi mode” and corresponding operation parameter).
[0068] It is to be understood that, in the second exemplary embodiment, the mode customized module 110 can determine process types needed to be handled through specific methods (such as, adding virtual key, modifying virtual key, deleting virtual key), and provides corresponding operation interfaces based on the determined process types. Such as, the mapping relation between the process types and the operation types can be preset (such as, “adding virtual key” corresponds to a click on the customized setting icon of the operation mode, “modifying virtual key” corresponds to double click on added or existed virtual key icon, “deleting virtual key” corresponds to long press on added or existed virtual key icon (such as, a continuous click operation more than three seconds)), when user does the operation type (such as, click) to a specific icon (such as, a customized setting icon of the operation mode), the mode customized module 110 determines that user sends out a corresponding process type command (such as, the command of adding virtual key; or, the mapping relation between the process types and the preset touch path is preset, when detects that user does the touch operation of the preset touch path, the mode customized module 110 determines that user sends out the corresponding process types.
[0069] Referring to FIG. 15 , FIG. 15 is a hardware structure diagram of the air conditioner realizing the customized control for air conditioner operation mode according to a preferable exemplary embodiment of the present disclosure. The air conditioner 2 includes a processing unit 20 , a memory unit 25 , a touch screen display system 26 and a customized control system of air conditioner operation mode 21 .
[0070] The touch screen display system 26 can be used for providing the human-computer interaction interface for user to input a command, and to output and display response data from the air conditioner for user command. In the exemplary embodiment, the human-computer interaction interface includes, but not limited to, a customized setting interface of operation mode.
[0071] As shown in FIG. 16 , FIG. 16 is a system frame diagram of the touch screen display system 26 shown in FIG. 15 . The touch screen display system 26 includes a touch detecting device 260 , a touch screen controller 261 and a display unit 262 . The display unit 262 can be used for displaying information content; the touch detecting device 260 and the touch screen controller 261 can be used for user to proceed touch operation by the touch screen display system 26 . Whereby, the touch detecting device 260 can be used for detecting a touch position of user and transfer the detected information to the touch screen controller 261 ; the touch screen controller 261 receives the touch position information sent by the touch detecting device 260 , and converts the received touch position information into contact coordinate information, transfers the converted contact coordinate information to the processing unit 20 , and receives an executive command sent from the processing unit 20 and executes.
[0072] In another exemplary embodiment of the present disclosure, the screen display system 26 can also be any other applicable display system having the touch function.
[0073] The memory unit 25 can be used for storing the customized control system for air conditioner operation mode 21 and the operation data of the customized control system for air conditioner operation mode 21 . It is to be noted that, the memory unit 25 can be either a separated memory device, or a general term of a plurality of different memory devices, no need to repeat herein.
[0074] The processing unit 10 can be used for calling and executing the customized control system for air conditioner operation mode 21 , so that, under the operation of user, the processing unit 20 can provide customized setting interfaces for the operation mode (such as, the interfaces shown in FIGS. 4-14 ) for user to customize the operation parameters of the air conditioner, generate and display a virtual key corresponding to the customized operation parameters, when a trigger command for the virtual key caused by user is received (such as, a click command), the processing unit 20 can operate according to the operation parameters corresponding to the virtual key. The processing unit 20 and the memory unit 25 can be a separate unit respectively, or integrated with each other to form a controller, no need to repeat herein.
[0075] In an exemplary embodiment, the operation parameters include a temperature parameter, a humidity parameter, a blowing direction parameter, a sleeping temperature curve parameter and an operation time parameter. In another exemplary embodiment, the operation parameters include the temperature parameter, the humidity parameter, the blowing direction parameter, the sleeping temperature curve parameter, the operation time parameter and/or any other applicable operation parameters (such as a display luminosity curve of the air conditioner, a display color parameter of the air conditioner, and so on).
[0076] In the exemplary embodiment, the customized setting interface of the operation mode includes a control interface of the conditioner (such as, the interface shown in FIG. 4 ), operation interfaces for adding the virtual keys (such as, the interfaces shown in FIGS. 5-13 ), operation interfaces for modifying the virtual keys (such as, the interfaces shown in FIGS. 5-13 ), an operation interface for deleting the virtual keys (such as, the interface shown in FIG. 14 ), a setting/modification interface for selected temperature parameter (such as, the interface shown in FIG. 6 ), a setting/modification interface for selected humidity parameter (such as, the interface shown in FIG. 6 ), a setting/modification interface for selecting operation time (such as, the interface shown in FIG. 13 ), setting/modification interfaces for selecting blowing direction parameter (such as, the interfaces shown in FIGS. 7-10 ), setting/modification operation interfaces for selecting sleeping temperature curve parameter (such as, the interfaces shown in FIGS. 11-12 ). In another exemplary embodiment, the customized setting interfaces of the operation mode include any applicable setting interfaces.
[0077] That is, one of an ordinary skill in the art should knows that: the parameter types included in the operation parameters cannot limit inventive ideas of the present disclosure; the interface types and forms included in the customized setting interfaces of the operation mode cannot limit the inventive ideas of the present disclosure.
[0078] As shown in FIG. 17 , FIG. 17 is a functional block diagram of the customized control system for air conditioner operation mode shown in FIG. 12 according to a preferred exemplary embodiment.
[0079] It is to be noted that, for an ordinary skill in the art, the functional block diagram shown in FIG. 17 is just a sample diagram of a preferred exemplary embodiment, ordinary skills in the art around the functional blocks of the customized control system of the air conditioner operation mode 21 shown in the FIG. 17 can add new functional blocks easily; a name of each functional block is a customized name, only used for understanding each application functional block of the customized control system of the air conditioner operation mode 11 , and cannot limit the technical solutions of the present disclosure, the core of the technical solutions of the present disclosure is that, the function which each function block having the custom name is aim to achieve.
[0080] The customized control system of air conditioner operation mode 21 includes a mode customized module 210 and a customized mode excitation module 212 . The functions of each function module of the customized control system of the air conditioner operation mode 21 can be:
Embodiment 1
[0081] The mode customized module 210 can be used for providing customized setting interface of operation mode for user to customize operation parameters of the air conditioner when the mode customized module 210 receives customized setting command for air conditioner operation mode sent by user. Embodiment 1, the mode customized module 210 provides customized add icons/keys of operation mode, when user uses the icons/keys (such as, “+mode” virtual key in the virtual keys area of operation mode 30 ) to do a preset mode operation (such as, click or double clicks), which determines that user sends out a customized adding command for the air conditioner operation mode; embodiment 2, when the mode customized module 210 detects that user does a touch operation of a preset touch path, which determines that user sends out a customized setting command for air conditioner operation mode.
[0082] The mode customized module 210 can also be used for generating and displaying virtual keys according to the customized operational parameters, when user finishes the customized setting of the operation mode based on the customized setting interface of operation mode.
[0083] It is to be understood that, in the first exemplary embodiment, the mode customized module 210 not only supports the above virtual keys adding function, but also supports a modification function for parameters corresponding to the existed virtual keys, and a deleting function for the existed virtual keys. The following will describe the functions of the mode customized module 210 based on FIGS. 4-14 :
[0084] When the customized adding command for the air conditioner operation mode sent out by user is received (such as, a command sent through clicking “+mode” virtual key in the virtual keys area of operation mode shown in FIG. 4 is received), the mode customized module 110 provides an interface as shown in FIG. 5 first (based on the interface, user can sets names of virtual cases corresponding to the operation mode needed to be customized, such as “wangwu mode” as shown in FIG. 5 ); when user selects and clicks a “temperature setting” key or a “humidity setting” key based on the interface shown in FIG. 5 , the mode customized module 210 provides an interface shown as FIG. 6 ; when user selects and clicks a “sweeping horizontally” key based on the interface shown in FIG. 5 , the mode customized module 210 provides interfaces shown as FIGS. 7-8 ; when user selects and clicks a “sweeping horizontally and orientationally” key based on the interface shown in FIG. 5 , the mode customized module 210 provides an interface shown as FIG. 9 ; when user selects and clicks a “sweeping vertically” key based on the interface shown in FIG. 5 , the mode customized module 210 provides an interface shown as FIG. 10 ; when user selects and clicks a “sleeping curve” key based on the interface shown in FIG. 5 , the mode customized module 210 provides an interface shown as FIG. 11 or FIG. 12 (if the interface shown as FIG. 11 is provided, a new interface for setting temperature curve pops up; if the interface shown as FIG. 12 is provided, the original interface displays the interface for setting temperature curve); when user selects and clicks a “operation time setting” key based on the interface shown in FIG. 5 , the mode customized module 210 provides interfaces shown as FIG. 13 .
[0085] The interface shown in FIG. 6 includes a movably touch-bar 31 , temperature/humidity setting value can be adjusted through moving and touching the movably touch-bar 31 , such as, moving toward “+” symbol can gradually add the temperature/humidity setting value according to a preset magnitude, moving toward “−” symbol can gradually reduce the temperature/humidity setting value according to a preset magnitude.
[0086] The interface shown in FIG. 7 includes a sweeping control identifier 32 , a sweeping horizontally area can be adjusted through moving and touching a threshold value control line S and/or E of the sweeping control identifier 32 (that is, a preset sweeping area can be defined as a area between the control line S and the control line E). When user moves and touches the control line of the sweeping control identifier 32 , a sweeping angle β of the threshold value control line can be dynamically displayed (such as, shown as FIG. 8 ).
[0087] The interface shown in FIG. 9 includes the sweeping control identifier 32 , a direction of the sweeping horizontally and orientationally can be adjusted by sliding a horizontal directional control line of the sweeping control identifier 32 .
[0088] The interface shown in FIG. 10 is similar with the interface shown in FIG. 7 , an operation mode of the interface shown in FIG. 10 is similar with an operation mode of the interface shown in FIG. 7 , no needed to repeat herein.
[0089] In the interface shown in FIG. 11 or FIG. 12 , curve parameters can be changed by moving and touching curves in a temperature-time coordinate.
[0090] When user uses the existed icons/keys (such as, the existed virtual key “zhangsan mode” or “lisi mode” in the virtual keys area of operation mode 30 shown in FIG. 4 ) to do an operation of preset type (such as, click or double-clicks), the mode customized module 210 determines that user sends out a customized modification command of air conditioner operation mode; or, when the mode customized module 210 detects that user does the touching operation of preset touch path, the mode customized module 210 determines that user sends out the customized modification command of air conditioner operation mode. It is to be understood that, the customized modification interface of the existed virtual keys can be similar or same with the above customized adding interface, no need to repeat herein.
[0091] When the customized deleting command of air conditioner operation (such as, a command sent out by clicking “−mode” virtual key in the virtual keys area of operation mode 30 shown in FIG. 4 ) sent out by user is received, the mode customized module 110 provides the interface shown in FIG. 14 first, user can select to delete the existed operation mode (such as, “zhangsan mode”, “lisi mode”, “wangerma mode”, “zhangqian mode” and/or “sunli mode”) based on the interface shown in FIG. 14 , “zhangsan mode” is selected in FIG. 14 as a example, when user clicks a “deleting key”, the existed “zhangsan mode” virtual key and operation parameters corresponding to the existed “zhangsan mode” virtual key are deleted.
[0092] It is to be understood that, the mode customized module 210 can also determine process types needed to be handled through another methods (such as, adding virtual key, modifying virtual key, deleting virtual key), and provides corresponding operation interfaces based on the determined process types. Such as, a mapping relation between the process types and the operation types can be preset (such as, “adding virtual key” corresponds to a click the icon, “modifying virtual key” corresponds to a double click the icon, “deleting virtual key” corresponds to a long pressing the icon (such as, click the icon continuously more than three seconds)), when user does the preset operation type (such as, click, double-click, long press) to a specific icon (such as, provided customized setting icon of the operation mode), the mode customized module 210 determines that user sends out a corresponding process type; or, a mapping relation between the process types and the preset touch path is preset, when detects that user does the touch operation of the preset touch path, the mode customized module 210 determines that user sends out the corresponding process types.
[0093] The customized mode excitation module 212 is used for controlling the air conditioner according to the operation parameters corresponding to virtual key when the customized mode excitation module 212 receives a trigger command for virtual key caused by user (such as, a virtual key named “zhangsan mode”).
Embodiment 2
[0094] The mode customized module 210 can be used for generating and displaying the virtual key that its operation parameter needs to be customized (such as, the virtual key is generated, default-generated name of the virtual key and icon of the virtual key can be a preset name and key icon respectively, or a name modifying command from user can be responded to modify the default-generated name and key icon, such as, the name is modified to “wangwu mode”) when receives the adding command of the virtual key sent out by user, when the customized setting command for air conditioner operation mode corresponding to the virtual key sent by user is received (such as the virtual key named “wangwu mode), customized setting interface is provided for user to customize operation parameters of air conditioner. Embodiment 1, the mode customized module 210 provides custom adding icon/key of operation mode, when user does an operation of preset type (such as, click or double-clicks) to the icon/key (such as, the “+mode” virtual key in the virtual keys area of operation mode 30 ), the mode customized module 210 determines that user sends out the customized adding command of air conditioner operation mode; embodiment 2, when the mode customized module 210 detects that user does the touch operation of the preset touch path, the mode customized module 210 determines that user sends out the customized setting command for air conditioner operation mode.
[0095] The mode customized module 210 can also be used for setting up the mapping relation between the customized operation parameter and the virtual key when the customized setting of the operation mode is finished by user based on customized setting interface of the operation mode.
[0096] The customized mode excitation module 212 can be used for controlling the operation of air conditioner according to the operation parameters corresponding to the virtual key when the trigger command for the virtual key (such as the virtual key named “wangwu mode”) caused by the user is received.
[0097] It is to be understood that, in the second exemplary embodiment, the mode customized module 210 not only supports the adding function of virtual key, but also supports the modification function of modifying the parameters corresponding to the existed virtual key, and the deleting function of deleting the existed virtual key. Such as, when the mode customized module 210 receives the customized adding command for the air conditioner operation mode corresponding to the existed virtual key (such as virtual key named “lisi mode”) sent out by user, the mode customized module 210 can be used for providing a customized modifying interface of the operation mode (such as, interfaces shown in FIGS. 5-13 ) for user to customize operation parameters of the air conditioner; when the mode customized module 210 receives the deleting command of the existed virtual keys sent out by user, the mode customized module 210 provides a customized deleting interface of the operation mode (such as, the interface shown in FIG. 14 ) for user to delete the existed virtual keys and corresponding operation parameters (such as, the virtual key named “lisi mode” and corresponding operation parameters).
[0098] It is to be understood that, in the second exemplary embodiment, the mode customized module 210 can determine process types needed to be handled through specific methods (such as, adding virtual key, modifying virtual key, deleting virtual key), and provides corresponding operation interfaces based on the determined process types. Such as, the mapping relation between the process types and the operation types can be preset (such as, “adding virtual key” corresponds to a click on the customized setting icon of the operation mode, “modifying virtual key” corresponds to double click on added or existed virtual key icon, “deleting virtual key” corresponds to a long press operation on added or existed virtual key icon (such as, a continuous click operation more than three seconds)), when user does the operation type (such as, click) according to a specific icon (such as, a customized setting icon of the operation mode), the mode customized module 210 determines that user sends out a corresponding process type command (such as, the command of adding virtual key; or, the mapping relation between the process types and the preset touch path is preset, when detects that user does the touch operation of the preset touch path, the mode customized module 210 determines that user sends out the corresponding process types.
[0099] As shown in FIG. 18 , FIG. 18 is a specific flow diagram of the customized control method for air conditioner operation mode according to a first exemplary embodiment.
[0100] Step S 10 , when the mode customized module 110 or the mode customized module 210 receives the customized setting command for air conditioner operation mode sent out by user, the mode customized module 110 or the mode customized module 210 provides the customized setting interface for operation mode for user to custom operation parameters of the air conditioner.
[0101] Step S 11 , the mode customized module 110 or the mode customized module 210 generates and displays virtual keys according to the customized operational parameters (such as, the virtual key named “zhangsan mode”), when user finishes the customized setting of the operation mode based on the customized setting interface of operation mode.
[0102] Step S 12 , the customized mode excitation module 212 controls the air conditioner according to the operation parameters corresponding to virtual key when the customized mode excitation module 112 receives a trigger command for the virtual key caused by user (such as, a virtual key named “zhangsan mode”); or, the customized mode excitation module 212 operates according to the operation parameters corresponding to virtual key when the customized mode excitation module 112 receives the trigger command for the virtual key caused by user (such as, a virtual key named “zhangsan mode”).
[0103] As shown in FIG. 19 , FIG. 19 is a specific flow diagram of the customized control method for air conditioner operation mode according to a second exemplary embodiment.
[0104] Step S 20 , when the mode customized module 110 or the mode customized module 210 receives the customized adding command for air conditioner operation mode sent out by user, the mode customized module 110 or the mode customized module 210 generates and displays the virtual key that that its operation parameter needs to be customized (such as, the virtual key is generated, default-generated name of the virtual key and icon of the virtual key can be a preset name and key icon respectively, or a name modifying command from user can be responded to modify the default-generated name and key icon, such as, the name is modified to “wangwu mode”).
[0105] Step S 21 , the mode customized module 110 or the mode customized module 210 provides the customized setting interface for user to customize operation parameters of air conditioner when the customized setting command for air conditioner operation mode corresponding to the virtual key (such as the virtual key named “wangwu mode) sent by user is received.
[0106] Step S 22 , the mode customized module 110 or the mode customized module 210 sets up the mapping relation between the customized operation parameter and the virtual key (such as, the virtual key named “zhangsan mode”) based on that the customized setting of the operation mode is finished by user based on customized setting interface of the operation mode.
[0107] Step S 23 , the customized mode excitation module 112 controls the operation of the air conditioner according to the operation parameters corresponding to the virtual key when the trigger command for the virtual key (such as the virtual key named “wangwu mode”) caused by the user is received; or, when the customized mode excitation module 112 receives the trigger command from the virtual key (such as the virtual key named “wangwu mode”) caused by the user, the customized mode excitation module 112 operates according to operation parameters corresponding to the virtual key.
[0108] It is to be understood that, in another exemplary embodiment of the present disclosure, beyond the step S 20 , the step S 21 , the step S 22 and the step S 23 , the customized control method for air conditioner operation mode can also include the following steps (not shown):
[0109] When the mode customized module 110 or the mode customized module 210 receives the customized modification command for air conditioner operation mode sent out by user and corresponding to the existed virtual key, the mode customized module 110 or the mode customized module 210 provides the customized modification interface for operation mode (such as, the interface shown in FIG. 8 ) for user to customize operation parameters of the air conditioner.
[0110] When the mode customized module 110 or the mode customized module 210 receives the customized deleting command for the existed virtual key (such as, the virtual key named “lisi mode”) sent out by user, the mode customized module 110 or the mode customized module 210 provides the customized deleting interface for operation mode (such as, the interface shown in FIG. 8 ) for user to delete the existed virtual key and correspond operation parameters (such as, the virtual key named “lisi mode” and corresponding operation parameters);
[0111] when the customized mode excitation module 212 receives the trigger command for the virtual key (such as the virtual key named “lisi mode”) caused by the user, the customized mode excitation module 212 controls the operation of the air conditioner according to the operation parameters corresponding to the virtual key; or, when the customized mode excitation module 212 receives the trigger command for the virtual key (such as the virtual key named “wangwu mode”) caused by the user, the customized mode excitation module 212 operates according to operation parameters corresponding to the virtual key.
[0112] The embodiments above are preferably embodiments of the present disclosure, and the patent scope of the present disclosure is not limited to such embodiments, equivalent structure conversion or equivalent flow transformation based on the specification and the drawing of the present disclosure, or directly or indirectly used in other related technical field, both similarly within the protection scope of the present disclosure.
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A customized control method for an air conditioner operation mode. The method includes: when a customized setting instruction for an air conditioner operation mode sent by a user is received, providing a customized setting interface of the operation mode for a user to set the air conditioner operation parameters in a customized manner, and mapping and relating operation parameters set in the customized manner to a virtual button, so that the differentiated presetting of the air conditioner operation parameters according to the difference of individual users is realized, and one-button operation is realized by mapping and relating the air conditioner operation parameters to the virtual button, thereby effectively increasing the convenience and accuracy of the operation of an air conditioner. Also disclosed is a customized control system for an air conditioner operation mode.
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FIELD OF INVENTION
[0001] The present invention relates to the field of defoaming equipment, and more particularly, to removing, defoaming, and storing large amounts of foam after a Blast Mitigation or Decontamination Foam has been used in either an open area or in a contained area.
BACKGROUND OF THE INVENTION
[0002] In the past, defoaming equipment was used primarily in the defoaming of carpets after a cleaning process. This was accomplished by vacuuming foam into a holding tank incorporated in a carpet cleaning machine and passively mixing it with some type of liquid defoamer. An example of such a system appears in U.S. patent application Ser. No. 5,813,086. This was done to break down the detergent in a simple and inexpensive manner, thereby reducing the space required to contain the spent liquid.
[0003] Current generations of Blast and Decontamination Foams are considerably thicker and more stable than industrial cleaning foams, are much harder to break down, and readily produce copious amounts of additional foam when agitated; all aspects that render conventional defoaming techniques impractical. These new foams include, for example, those described in U.S. patent application Ser. No. 6,405,626, issuing on Jun. 18, 2002 and titled “Decontaminating and Dispersion Suppressing Foam Formulation”, and in U.S. patent application Ser. No. 6,553,887, issuing on Apr. 29, 2003 and titled “Foam Formulations”. There is a need for a method of, and an apparatus for breaking down and collecting these new foams.
[0004] These new foams may be employed in a variety of manners. For example, Blast Mitigation Structures have been developed such as those described in U.S. patent application Ser. No. 6,439,120, issuing on Aug. 27, 2002, and titled “Apparatus and Method for Blast Suppression”. In short, this patent describes the process of placing a fabric tent-like structure over a suspect package, filling the tent with Blast Mitigation Foam, and detonating the suspect package. The tent-like structure and Blast Mitigation Foam absorb the energy of the explosion and contain any contaminants. The contents of the Blast Mitigation Structure must then be removed and disposed of, while minimizing the risk of exposing technicians and/or the environment to hazardous materials. This is also preferably done without coating the Blast Mitigation Structure with defoaming compound, which might compromise the use of the Blast Mitigation Structure in the future. Presently, there are no effective ways of doing this.
[0005] Similarly, various foams may be used to decontaminate vehicles or surface areas exposed to chemical, biological or radiological components or similar threats. No effective means or methods of collecting such decontaminant foams are currently available.
[0006] There is therefore a need for a method of and apparatus for defoaming, provided with consideration for the problems outlined above.
SUMMARY OF THE INVENTION
[0007] It is therefore an object of the invention to provide an improved method of, and an apparatus for defoaming, which obviates or mitigates at least one of the disadvantages described above.
[0008] The present invention allows for the defoaming of Blast Mitigation Foam systems (such as the Universal Containment System available from Allen-Vanguard Corporation) as well as small or large scale Area Decontamination or Containment Foams.
[0009] This is accomplished by first mixing a measured amount of defoaming liquid to the proper ratio of water in a holding tank. Any defoaming agent can be used with the mechanical system of the described invention. In order to break the foaming capability of the originally dispensed foam, the defoaming agent must simply have a lower surface tension than the surfactant used to generate the foam in the first place.
[0010] The defoaming agent is then pumped through a series of hoses dispensing it into the collected foam through one or more injectors located near a vacuum nozzle head and again through one or more injectors located where the suction hose enters the holding tank. The defoaming agent is constantly re-circulated throughout the system to continually provide contact with the foam that is being extracted.
[0011] When used with a Blast Mitigation Structure (BMS), the foam is brought in through an arcuate vacuum suction nozzle, specifically designed to accommodate the BMS. The arcuate nozzle has been designed to present a very low profile to minimize any residue remaining in the tent, and is shaped to match the floor opening of the BMS so that it can extract the foam from within the tent over the largest possible area, with minimum risk of coming into contact with and possibly triggering, an explosive device that the system is containing.
[0012] The same process and apparatus may be used to collect foam from the decontamination of vehicles or areas. It is preferred to use an elongated nozzle to perform such defoaming, the elongated nozzle having a squeegee surface on three sides to help direct the suction and draw the foam in.
[0013] The system will break down and retain Blast Mitigation Foam and Area Decontaminating Foam containing pertinent forensic evidence. The system will also break down and retain Blast Mitigation Foam and Decontaminating Foam containing the by-products of chemical, biological, and radiological particles.
[0014] The holding tank on this system can be removed and replaced when full capacity is reached. This allows continued defoaming, almost immediate gathering of evidence, and quick containment and scientific study for the presence of chemical and biological by-products as well as radiological particles.
[0015] According to an embodiment of the invention there is provided an apparatus for defoaming, comprising: a vacuum system for collecting foam, the vacuum system including a vacuum head for drawing the foam through a suction hose terminating in a nozzle, the vacuum system feeding the foam into a holding tank; the holding tank initially storing a quantity of defoaming agent; and a pump for drawing the defoaming agent from the holding tank and feeding the defoaming agent to at least one injector, the at least one injector being fitted on the vacuum-side of the vacuum system, whereby the defoaming agent is actively mixed with the collected foam, reducing the collected foam, and the reduced foam and defoaming agent are recirculated through the pump; the nozzle, the suction hose, the vacuum system, the at least one injector and the holding tank being of chemical-resistant construction.
[0016] According to another embodiment of the invention there is provided a method of defoaming comprising the steps of: collecting foam using a vacuum system, the vacuum system including a vacuum head for drawing the foam through a suction hose terminating in a nozzle, the vacuum system feeding the foam into a holding tank; initially storing a quantity of defoaming agent in the holding tank; and drawing the defoaming agent from the holding tank and feeding the defoaming agent to at least one injector using a pump, the at least one injector being fitted on the vacuum-side of the vacuum system, whereby the defoaming agent is actively mixed with the collected foam, reducing the collected foam, and the reduced foam and defoaming agent are recirculated through the pump; the nozzle, the suction hose, the vacuum system, the at least one injector and the holding tank being of chemical-resistant construction.
[0017] This summary of the invention does not necessarily describe all features of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings wherein:
[0019] FIG. 1 presents a perspective, partially-exploded view of a defoaming system in an embodiment of the invention;
[0020] FIGS. 2A and 2B present front and side views respectively, of the defoaming system of FIG. 1 , further including a holding tank and lid for the holding tank;
[0021] FIG. 3 presents an electrical and process schematic in an embodiment of the invention;
[0022] FIG. 4 presents a detail of the electrical wiring in an embodiment of the invention;
[0023] FIGS. 5A, 5B and 5 C present top, side and perspective views of an arcuate nozzle in an embodiment of the invention; and
[0024] FIGS. 6A, 6B and 6 C present bottom, side and perspective views of an elongated nozzle in an embodiment of the invention.
DETAILED DESCRIPTION
[0025] An exemplary apparatus for implementing the invention will be described with respect to the embodiments appearing in FIGS. 1-6 . A partial parts list of the components used in these embodiments is summarized in the following table:
DEFOAMER MATERIALS LIST Item Part Part Description Part # Supplier 10 Vacuum Head ShopVac ShopVac 12 BMF Nozzle Suction Nozzle (BMF) TD-DF-007 VRS 14 SDF Nozzle Suction Nozzle (SDF) TD-DF-008 VRS 16 Suction Hose 2½″ Hose 18 Holding Tank 65 Gal. Overpack 1065-YE Enpac 20 Pump Diaphragm Pump 2088-594-500 SHURflo 22 & 24 Mixing Nozzle Kynar VeeJet H-1/8-V V -KY 120 08 John Brooks 26 & 28 Return Nozzle Kynar VeeJet H-1/8-V V -KY 120 08 John Brooks 30, 32 & Outlet Line ⅛″ Tubing G3 34 36 & 38 Return line ⅛″ Tubing G3 40 Ball Valve ¼″ Female × Female 42 Drop Tube ⅝″ Tubing 44 Inlet Line ½″ Tubing 46 Outlet Line ½″ Tubing 48 Holding Tank Lid Enpac
[0026] FIG. 1 presents a perspective view of the components of the system, with the holding tank 18 removed so that the interior drop tube 42 can be seen. The lid 48 of the holding tank 18 is also not shown in FIG. 1 so that the relationship of the pump 20 and other components can be seen. All of these components, including the lid 48 and holding tank 18 , are shown in FIGS. 2A and 2B . The pump 20 and other components are shown in a partially exploded view in FIG. 1 , but are generally mounted on the lid 48 of the holding tank 18 as shown in FIGS. 2A and 2B . The pump 20 may be mounted directly on the lid 48 , supported by standoffs or some other for of bracket.
[0027] FIG. 3 presents the same system schematically, showing both the electrical control and process flow. The electrical control is quite simple in this embodiment as the pump 20 and vacuum head 10 are powered and controlled independently of one another, from 120 VAC sources via separate electrical cords V 1 and V 2 . These two devices may be are turned on and off with manual electrical switches, or alternatively, a simple electrical interlock system may be employed to ensure that the pump 20 only operates when the vacuum head 10 is running (to prevent defoaming agent from accidentally pouring out through the nozzle 12 , 14 ). Other safety interlocks may also be provided, for example, to shut the system down in the event that the holding tank 18 is full, or missing.
[0028] FIG. 4 presents an exemplary electrical control system in which the pump is hard-wired to a toggle switch 50 , which receives power from the line side of a 120 VAC insulated receptacle 52 . The insulated receptacle 52 is used to bring power to the vacuum head 10 , and is powered by an electrical cord V 3 .
[0029] In the operation of the defoaming system a measured amount of defoaming solution is mixed with a measured amount of water and is poured into the holding tank 18 . The holding tank 18 may consist of any suitable container that vacuum head 10 may be mounted on, or may be connected to via suitable pipes or hoses. This may include, for example, a stock plastic container from ShopVac, or a sealable container suitable for storage and transport of radioactive or biological waste, or even containers permanently mounted on vehicles or trailers. The Enpac 1065-YE has the particularly convenient features of being nestable, having a gasketed lid which seals the contents, being approved for use as a waste handling container and being fabricated of a relatively chemically inert polyethylene.
[0030] The pump 20 is turned to the on position and the defoaming solution is drawn up the drop tube 42 through inlet line 44 to pump 20 . The defoaming solution is then brought through the pump 20 into outlet line 46 , it is allowed free travel down return line 38 to tank return nozzle 26 through return line 36 and into tank return nozzle 28 . This is the re-circulate only mode.
[0031] Pump 20 identified above is a self-priming diaphragm pump which operates on 120 VAC, and deliveries a flow rate of up to 3 gallons per minute (though the flow rate does vary with the back pressure). Like the other components of the system, the portions of the pump 20 that are in contact with the defoaming agent and foam being collected are made of chemically resistant materials. Of course, other similar pumps could also be used. The voltage for the pump, for example could be specified to match whatever voltage is locally available.
[0032] The spray nozzles 22 , 24 , 26 and 28 are KYNAR™ VeeJet™, small capacity injectors, which provide a flat spray that is easy to align. They are also made out of chemical and corrosion-resistant material. Other injectors could also be used.
[0033] There are many suitable wet/dry vacuum heads 10 available, which again, are preferably of chemical resistant construction. The voltage for the vacuum head 10 should also match whatever is locally available.
[0034] As the remaining liquid flows past tank return nozzle 26 it is directed by a directional control valve 40 , such as a ball valve. If the solution reaches valve 40 in the closed position it is only allowed to circulate as described above. When valve 40 is in the opened position the solution travels down outlet line 30 diverting at the junction of outlet line 32 and outlet line 34 and out mixing nozzle 22 and mixing nozzle 24 .
[0035] Turning the power on at vacuum head 10 causes a vacuum in suction hose 16 . The vacuum in suction hose 16 causes the foam to be drawn in through suction nozzle 12 into suction hose 16 where it comes into contact with defoaming solution through mixing nozzles 22 and 24 . The foam continues up suction hose 16 through vacuum head 10 where it is hit again with the defoaming solution through return nozzles 26 and 36 .
[0036] At this point the foam has been brought back to a liquid state, falls into holding tank 18 is steadily sprayed from return nozzles 26 and 28 and the cycle continues.
[0037] The appropriate fittings, adapters, tubing, couplings, elbows, bushing, tees, straps and strainers required for any given implementation would be clear to the person skilled in the art.
[0038] FIGS. 5 and 6 present exemplary vacuum nozzles that could be used with the invention. Of course, other designs could also be used depending on the application. The details of these two designs are given hereinafter, with respect to the description of their particular applications. Exemplary applications of the invention are as follows:
[0000] Blast Mitigation Foam (BMF)
[0039] This form of defoaming can be used for many scenarios, three examples of which are given below:
[0040] 1) In the case where a trained Security Guard discovers a suspect package, he would place a Blast Mitigation Structure (BMS) over the suspect package and fill said structure with Mitigating Foam (MF) rendering the area relatively safe. A suitable BMS would be, for example, the Universal Containment System available from Vanguard Response Systems. A suitable MF would be, for example, GCE-2000 available from Vanguard Response Systems.
[0041] The BMS would remain in place until the proper Law Enforcement Agency arrives at the scene. At this time Law Enforcement may wish to determine (through x-ray) whether the suspect package is a serious threat. At this point the MF must be evacuated in order to x-ray and place the desired detonating device. The system of the invention provides the only suitable way of performing this evacuation of the MF.
[0042] 2) A BMS is placed over a suspect package by a trained Law Enforcement Officer and the desired detonating device is placed. The BMS is filled with MF and the package detonated. It is now desirable to collect any blast related evidence. The BMS can be lifted and the MF allowed to flow, but then the evidence would also be allowed to flow with it into tall grass or into drains, or through cracks and crevices. Similarly, if the package was a “dirty bomb” containing some form of contaminant, lifting the BMS would allow the contaminant to escape. Clearly, this is not desirable.
[0043] 3) A BMS is placed over a suspect package by a trained Law Enforcement Officer, the package is X-rayed and then disruptors are suitably positioned for maximum effect. The BMS is filled with MF and the disruptors fired. It is now desirable to remove the foam to establish whether the disruptors had the desired effect, or if additional means have to be employed and the BMS refoamed. At the same time It is necessary to ensure that there is no loss of valuable forensic evidence throughout this process.
[0044] The suction nozzle of FIGS. 5A, 5B and 5 C is specifically developed for non-interference with suspect packages when covered by the BMS. As shown, this suction nozzle is Vacuum Formed from a chemically-resistant polymer. The low profile of this suction nozzle allows it to be slipped under the edge of the BMS.
[0045] The indentations in the two arc-shaped plates 60 not only hold the nozzle together and space the two plates apart, and help distribute the suction from the vacuum. Without such distribution, the vacuum would tend to draw foam from a very small area, simply creating a hole, rather than drawing all of the foam more uniformly from the BMS.
[0046] In operation, the suction nozzle of FIGS. 5A, 5B and 5 C is inserted into the BMS, and a vacuum applied to pull the MF from the BMS. As the MF is evacuated it is sprayed with the defoaming solution as it enters the vacuum hose first and then again as it enters the holding tank. This recycling of the defoaming solution continues until the MF is brought to a low enough height within the BMS to allow properly trained Law Enforcement personnel to safely perform their required tasks. The holding tank is then removed, capped and replaced. This allows each holding tank to be removed and its contents examined for possible forensic evidence.
[0047] Note that it may be desirable in some applications to include a strainer or screen over the suction nozzle. This might be desirable, for example, when used with a BMS to ensure that small items such as detonators are not collected into the holding tank of the defoaming system.
[0048] This operation remains the same with the presence of a chemical, biological or radiological threat.
[0000] Area Decontamination or Containment Foams
[0049] Area decontamination and containment foams are used where Chemical, Biological, Radiological or other hazardous materials have been discovered.
[0050] The Decontamination or Containment Foam is applied over the contaminated area eliminating the risk of further air born particles, and neutralizing chemical and biological agents.
[0000] Chemical and Biological Surface Decontamination
[0051] In the case of military type chemical or biological threats, Decontamination Foam will neutralize the Contaminating Agent after application and a stated contact time. In the case of other Hazardous materials foam can be used to contain dangerous off gassing to reduce the surrounding area affected. The Defoamer in this instance is primarily used as a high capacity clean up tool. It does however, hold the remaining active agent in close proximity with the decontamination solution allowing the contact time to effect more complete neutralization, and assists in the retention of any forensic evidence that may be present, and will help to suck up and store, for subsequent clean up operations, any hazardous liquids or powders that might be present.
[0000] Radiological Surface Decontamination
[0052] In the case of a radiological cleanup, decontamination solution is applied to prevent the radiological particles from becoming air born. During cleanup, the Defoamer holding tank 18 will contain this hazard allowing the clean up operation for transfer to another permanent storage container if required.
[0053] In the case of area decontamination a modified elongated nozzle 14 as shown in FIGS. 6A, 6B and 6 C is used to collect the Surface Decontamination Foam (SDF) and allow it to be vacuumed into the path of the defoaming solution. This elongated nozzle 14 is quite similar to conventional elongated vacuum nozzles, except that it only has a squeegee surface on three sides—the two short sides 70 , 72 and one long side 74 (the side closest to the vacuum hose 16 ).
[0054] As the SDF enters the suction hose 16 it is sprayed with this defoaming solution by two (2) nozzles 22 , 24 oriented at approximately 120° with respect to the direction of flow of the foam being collected. The mixture continues up the suction hose 16 in constant contact with one another and is again sprayed with defoaming solution as it enters the holding tank 18 . The foam head in the holding tank 18 is also constantly sprayed with defoaming solution to further increase the defoaming rate.
[0000] The Defoaming Chemical:
[0055] Any defoaming agent can be used with the mechanical system of the described invention. The defoamer, in order to break the foaming capability of the originally dispensed foam, must simply have a lower surface tension than the surfactant used to generate the foam in the first place. This will provide the desired thinning and collapse of the lamella.
[0056] Possible chemical structures for defoamers are molecules with a low surface tension, such as silicone, mineral oils, fatty acids and fluorocarbons. The mechanical system of this invention provides the search stress to the solution in order to ensure the distribution of the chosen chemical defoamer.
[0057] The system is also designed to provide a means for the defoamer chemical to be recycled in order to continually provide contact to the foam that is being extracted. This improves the mechanical mixing, the contact between the defoaming chemicals and the foam, and minimizes the use of defoaming chemicals in this application for maximum cost effectiveness. Therefore, the ratio of defoamer to surfactant should be great enough to provide defoaming capability to the complete liquid volume of the holding tank. If these parameters are simply unknown to the end user (e.g. surface tension values, total volume), the system at any time can be stopped and more chemical defoamer can simply be added to the holding tank 18 . This does not in any way jeopardize the application.
[0058] It should be noted however, that although the type of defoamer is not a critical component, care should be taken to ensure that a non-hazardous chemical solution is chosen in order to ensure the safety of the operator. Several non-toxic, biodegradable and environmentally friendly defoamers are available on the market to choose from. The selection of a suitable defoaming solution would be clear to one skilled in the art.
[0059] All citations are hereby incorporated by reference.
[0060] The present invention has been described with regard to one or more embodiments. However, it will be apparent to persons skilled in the art that a number of variations and modifications can be made without departing from the scope of the invention as defined in the claims.
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The present invention relates to the field of defoaming equipment, and more particularly, to removing, defoaming, and storing large amounts of foam after a Blast Mitigation or Decontamination Foam has been used in either an open area or in an contained area. The invention provides an apparatus for defoaming, comprising: a vacuum system for collecting foam, the vacuum system including a vacuum head for drawing the foam through a suction hose terminating in a nozzle, the vacuum system feeding the foam into a holding tank; the holding tank initially storing a quantity of defoaming agent; and a pump for drawing the defoaming agent from the holding tank and feeding the defoaming agent to at least one injector, the at least one injector being fitted on the vacuum-side of the vacuum system, whereby the defoaming agent is actively mixed with the collected foam, reducing the collected foam, and the reduced foam and defoaming agent are recirculated through the pump; the nozzle, the suction hose, the vacuum system, the at least one injector and the holding tank being of chemical-resistant construction.
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FIELD OF THE INVENTION
[0001] This invention relates to digital media container racks and, in particular, a divider, spacer or support for such racks.
BACKGROUND TO THE INVENTION
[0002] Digital media container racks come in a variety of forms. They are generally configured to hold a number of generally standard-sized thin rectangular prism-shaped holders for compact disks, digital video disks, video compact disks, mini-disks or similar.
[0003] Amongst the variety of forms are racks that provide a generally upright rack having a plurality of substantially horizontal tubular cross members onto which the digital media containers can reside. There may be a desire to place vertical dividers between adjacent tubular members to either separate different sets of containers or to further support the tubular members themselves.
[0004] The difficulty in providing such dividers is that they need to be easily movable along the tubular members or even entirely removable from the rack while sufficiently stable and secure when attached to provide some form of support. Current mechanisms generally provide static dividers at fixed points or easily movable dividers that are not secure once attached to the tubular members.
OBJECT OF THE INVENTION
[0005] It is an object of the present invention to provide a divider for a digital media container rack or a rack with such dividers that may overcome some of the disadvantages of the prior art and provide a relatively easily releasable yet secure divider at an economical cost.
SUMMARY OF THE INVENTION
[0006] Accordingly, in a first aspect, the invention may broadly be said to consist in a digital media container rack comprising:
[0007] a generally upright rack having abase and at least opposed sides extending from said base;
[0008] a plurality of generally tubular members attached to and extending between said opposed sides;
[0009] at least one divider for extending between said generally tubular members having attachment means at or adjacent opposed ends of said divider for attachment to said generally tubular members; and
[0010] wherein at least one of said attachment means includes two arc-shaped members pivotally interconnected by a hinge and wherein each set arc-shaped member is resiliently supported from said divider intermediate of said pivotal connection and an opposed end of said arc-shaped member.
[0011] Accordingly, in a second aspect, the invention may broadly be said to consist in a divider for a digital media container rack having a plurality of generally tubular support members comprising:
[0012] at least one elongate member for extending between said generally tubular members having attachment means at or adjacent opposed ends of said elongate member for attachment to said generally tubular members; and
[0013] wherein at least one of said attachment means includes two arc-shaped members pivotally interconnected by a hinge and wherein each set arc-shaped member is resiliently supported from said divider intermediate of said pivotal connection and an opposed end of said arc-shaped member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] This invention will now be described by way of preferred embodiments with reference to the following drawings in which:
[0015] [0015]FIG. 1 shows a digital media rack in accordance with a first embodiment of the invention;
[0016] [0016]FIG. 2 shows a perspective view of a divider in a first configuration in accordance with the first embodiment of the invention;
[0017] [0017]FIG. 3 shows a perspective view of the divider of FIG. 2 in a second configuration;
[0018] [0018]FIG. 4 shows a longitudinal cross-sectional view through the apparatus of FIG. 3;
[0019] [0019]FIG. 5 is a perspective view of a portion of the apparatus of FIG. 4; and
[0020] [0020]FIG. 6 is a perspective view of the portion of the apparatus of FIG. 5 when in the second configuration.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0021] A particular preferred embodiment of the invention is shown in FIG. 1. This particular version comprises a digital media container rack 1 having a base portion 2 formed by the separate foot-light portions as shown supporting substantially upright opposed walls 3 and 4 . The opposed sides or walls 3 and 4 may comprise substantially planar solid walls as shown or any form of structure such as a thrust or frame or similar to provide support points for racks to carry the digital media containers.
[0022] The base portion 2 in this instance is provided as feet at the base of each of the sidewalls 3 and 4 although could equally be provided by the underside edge of those walls themselves or any form of leg or interconnecting base portion as may be desired to support the generally upright walls and assist in the prevention of overturning of the rack 1 .
[0023] Individual racks 5 are generally formed by the use of generally tubular interconnecting members 6 that progress between the opposed sidewalls. Rather than being formed from solid shelves, a few appropriately positioned members 6 can provide sufficient support against opposed edges of a digital media container so as to retain the container within the structure.
[0024] In this preferred embodiment, three such tubular members 6 are provided to form each individual rack being an upper tubular member 7 , a lower front tubular member 8 and a lower rear tubular member 9 . The exact configuration of these tubular members is not essential to the invention and more or less tubular members could be used as could different configurations if desired. This particular configuration seeks to retain the containers in such a manner as to leave the space above and in front of the container clear for easy removal.
[0025] Referring to FIG. 1, a plurality of divider members 10 is also apparent. The dividers may extend between any adjacent tubular members and are generally provided to extend between the lower front and upper tubular members 7 and 8 as shown.
[0026] The divider 10 seeks to provide some additional support against a plurality of digital media containers such as jewel cases placed in each rack. The divider may support the outer side of a progression of such containers to stop the containers falling over or may act as a divider between different categories of containers. As an additional function, the divider 10 may provide some support between adjacent tubular members by providing some additional stiffening of the tubular member resultant from it being interconnected with another such member.
[0027] Given the purposes of such dividers, it is preferable that they are capable of clamping onto the tubular members such that they are not easily moved from a particularly desired position until such movement is wished for. Such movement may be regularly required as containers are taken out from the rack or additional containers provided and the particular region of divisional support has changed.
[0028] Referring to FIG. 2, the divider 10 can be seen to comprise a substantially elongate member 14 having attachment means 11 and 12 at or adjacent distal ends for attachment to the tubular members. A first attachment means 11 is shown as comprising no more than a simple C-section opening at the end of the member to engage around the tubular member without being firmly fixed. It is the second engagement means 12 that may provide the majority of the engagement to prevent dislodgement of the divider 10 .
[0029] The second engagement means 12 seeks to provide a more substantial connection and is shown in FIG. 2 as a substantially ring-shape structure 15 that engages around the tubular member. However, it should be noted that such a connection is preferably provided in a manner to grip the tubular member so as to minimize easy movement of the divider along the tubular member until desired as well as preventing any relative movement transverse to the tubular member that may allow either of the attachment means 11 or 12 to disconnect. The engagement means 12 should also be provided in a manner as to be releasable when required.
[0030] [0030]FIG. 3 shows the divider 10 in a second configuration. The divider 10 now has an open attachment means 12 with the ring-like member 15 split to provide excess 16 for the tubular member into the attachment. This attachment mechanism is further described with reference to FIGS. 4 to 6 .
[0031] Referring to FIG. 4, a divider 10 is shown in partial cross-section such that the internal support structure 18 for the attachment means 12 is shown. The support structure 18 may be contained within a hub 17 adjacent that end of the elongate member 10 .
[0032] Referring to FIGS. 5 and 6, the support structure 18 and the attachment means 12 can be seen in a first or closed configuration and a second or closed configuration respectively. The attachment means 12 in this preferred form comprises two arc shaped members 20 , 21 having a pivotal interconnection 22 adjoining adjacent ends. The distal ends of the arc shaped members 20 and 21 are not connected. As shown in FIG. 5, the arc like members 20 and 21 are capable of coming together by rotation about the pivotal connection 22 so as to form a substantially ring shaped structure. It is not necessary that the distal ends of the arc shaped members actually meet and some gap between those may be accommodated. The arc shaped members merely need to progress such that the gap between the distal ends of the members in the closed configuration is less than the width of the tubular member to which they are to be attached so as to secure the tubular member within.
[0033] The support structure 18 as shown in FIGS. 5 and 6 comprises a resilient support attached to each of the arc shaped members at positions intermediate of the pivotal connection between the members and their distal ends. The support is not rigid as the arc like members require some flexibility in the support to move between the first and second configurations.
[0034] The points of connection 23 and 24 between each of the arc shaped members and the support are capable of resilient movement away from each other. As shown in FIG. 6, the pivotal connection 22 must pass between these points 23 and 24 to reach the position shown in FIG. 5. This movement requires additional spacing between the points to accommodate the movement. The use of a resilient material in the support 18 or any other form of bias against this separation of the points 23 and 24 from each other applies a bias to hold the arc shaped members in the stable positions shown in FIGS. 5 and 6 and resist movement between the two. However, such a bias is not so great as to be unable to be overcome by a user upon application of force to a release lever 25 . Simply pushing on this lever 25 attached to one of the arc shaped members causes rotation of the member and release of the tubular member to which the attachment means 12 may be connected.
[0035] It will be appreciated. that the attachment means in the form of attachment means 12 could be used at both ends of the divider 10 if desired. However, deepening of the C-shaped channel at the attachment means 11 means that this cannot release a tubular member until the end adjacent the attachment means 12 has also been released.
[0036] Hence it can be seen that the invention provides a relatively simple yet effective method of attaching a divider between members in a digital media rack.
[0037] This invention has been described with reference to preferred embodiments and it should be noted that other embodiments will become apparent to those skilled in the art to which the invention relates. This description of preferred embodiment is not to be considered limiting to the scope of the invention. Specific integers referred to in the description are deemed to incorporate known equivalents where appropriate.
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This invention relates to a rack for digital media containers such as compact disc jewel boxes. The unit contains a base and opposed sides, between which a plurality of tubular members are provided to hold the containers. Dividers are provided between adjacent tubular members and have attachment means at at least one end formed from two arc like members, supported on a resilient support to the divider and having a pivotal connection between the points of support from the divider so as to be able to assume an open and a closed stable position.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
Activated carbons are high porosity, high surface area materials used in industry for purification and chemical recovery operations as well as environmental remediation. Toxic metals contamination of various water sources is a significant problem in many parts of the United States. Activated carbons, which can be produced from a number of precursor materials including coal, wood and agricultural wastes, are now being actively utilized for remediation of this problem. Carbon production is an expanding industry in the United States, with a present production rate of over 300 million pounds a year and a growth rate of over 5% annually. The present invention relates to the development of specifically modified granular carbons from agricultural waste products that possess enhanced adsorption properties with regard to the uptake of metal ions.
2. Description of the Prior Art
The production of carbon, in the form of charcoal, is an age-old art. Carbon, when produced by non-oxidative pyrolysis, is a relatively inactive material possessing a surface area limited to several square meters per gram. In order to enhance its activity, a number of protocols have been developed. These include chemical treatment of the carbonaceous material with various salts or acids prior to pyrolysis, or a reaction of the already pyrolyzed product with high temperature steam. Activated carbon is able to preferentially adsorb organic compounds and non-polar materials from either liquid or gaseous media. This property has been attributed to its possession of a form which conveys the desirable physical properties of high porosity and large surface area.
Whitehead et al., in a paper entitled "Studies in the Utilization of Georgia Pecans", (State Engineering Experiment Station Bulletin, The Georgia School of Technology, Vol.1, No.5, December 1938, pp. 3-11), disclose the production of activated charcoal by treating pecan hulls with hydrochloric acid and then heating in an atmosphere of carbon dioxide for four hours at a temperature ranging from 800-1000° C. This product was described as having the same decolorizing power on water solutions of azo dyes as commercially available activated charcoals.
Bevia et al., in an article entitled "Activated Carbon from Almond Shells. Chemical Activation. 1. Activating Reagent Selection and Variables Influence" (Ind. Eng. Chem. Prod. Res. Dev. 1984, 23, 266-269), discuss the preparation of activated carbon from almond shells. The activating chemicals H 3 PO 4 , ZnCl 2 , K 2 CO 3 , and Na 2 CO 3 were utilized in the study, with products derived from activation by ZnCl 2 giving the best results. It was further found that the impregnation ratio (activating reagent/raw material) was the most critical parameter, with materials made at ratios higher than 100% giving the best products.
Jagtoyen et al., in their paper entitled "Some Considerations of the Origin of Porosity in Carbons from Chemically Activated Wood", (Carbon, Vol. 31, No. 7, pp.1185-1192, 1993), investigated the conversion of white oak to activated carbons by reaction with phosphoric acid and subsequent heat treatment under nitrogen to temperatures ranging from 50° C. to 650° C. They found that the carbon structures created undergo significant expansion, with an accompanying development of high surface area, at reaction temperatures ranging from 250° C. to 450° C. At reaction temperatures above 450° C. there is secondary product contraction with an associated loss of product porosity. From this evidence it was concluded that porosity development is directly related to the retention and dilation of cellular material.
Molina-Sabio et al., in their paper entitled "Modification in Porous Texture and Oxygen Surface Groups of Activated Carbons by Oxidation", (Characterization of Porous Solids II, Rodriguez-Reinoso et al., [edit.] 1991 Elsevier Science Publishers B.V., Amsterdam), disclose that while oxidation treatment of fruit pits by either air or chemical means (HNO 3 or H 2 O 2 ) does not substantially modify the microporosity of the carbon structures created, the chemical nature of the carbon surface is changed considerably. No projected uses for these carbons are set forth.
Molina-Sabio et al., in a publication entitled "Influence of the Atmosphere used in the Carbonization of Phosphoric Acid Impregnated of Peach Stones" (Carbon, pp. 1180-1182, 1995), teach that the inclusion of air during the heating step of the acid activation of carbons should not result in any appreciable reaction with the carbon material. This is premised upon the fact that there is a continuous evolution of decomposition gases during the activation process.
Periasamy et al., in an article entitled "Process Development for Removal and Recovery of Cadmium from Wastewater by a Low-Cost Adsorbent: Adsorption Rates and Equilibrium Studies", (Ind. Eng. Chem. Res., 33, 317-320, 1994), show that at a concentration of 0.7 g/L, activated carbon produced from peanut hulls was able to achieve an almost quantitative removal of Cd(II) present at a concentration of 20 mg/L in an aqueous solution at a pH range of 3.5-9.5.
Balci et al., in their article "Characterization of Activated Carbon Produced from Almond Shell and Hazelnut Shell", (J. Chem. Tech. Biotechnol., 1994, 60, 419-426), show that chemical activation of ammonium chloride-impregnated almond and hazelnut shell at 350° C. and 700° C. gave products with surface area values in excess of 500 m 2 /g and 700 m 2 /g respectively. These values were approximately twice that observed for products derived from untreated raw materials.
Moreno-Castilla et al., in an article entitled "Activated Carbon Surface Modifications by Nitric Acid, Hydrogen Peroxide, and Ammonium Peroxydisulfate Treatments" (Langmuir, 1995, 11, 4386-4392), disclose the principle that acidic oxygen surface complexes are formed on activated carbons as a result of their treatment with either gas or solution phase oxidizing agents; and that inclusion of these complexes effect changes in the behavior of activated carbons when used either as adsorbents or catalysts.
Rivera-Utrilla et al., in their publication entitled "Effect of Carbon--Oxygen and Carbon--Nitrogen Surface Complexes on the Adsorption of Cations by Activated Carbons", (Adsorption Science & Technology, 1986, 3, 293-302), disclose that activated carbons obtained from almond shells are capable of removing trace amounts of various metal ions from aqueous solutions.
While various methodologies for the creation of granular activated carbons exist, there remains a need for the creation of alternate viable and cost-effective products possessing enhanced adsorption characteristics.
SUMMARY OF THE INVENTION
We have now developed a novel process, which when carried out within specific operational parameters, effects the creation of activated carbons from nutshells possessing enhanced activity for the adsorption of metal ions. This method involves concurrent utilization of chemical activation and atmospheric oxidation with the lignocellulosic material. While not wishing to be held thereto, it is the belief of the inventors that concurrent atmospheric oxidation in conjunction with chemical activation of the nutshell carbon produces metallic ion binding oxygen functions in the mesopore and macropore regions of the carbon. Carbons produced by this process show metal adsorption capacities greater than that possessed by existing commercial carbons.
In accordance with this discovery, it is an object of the invention to provide a means for the creation of high quality metals-adsorbing carbons.
Another object is to provide activated carbon materials having high metal-adsorbing capacity.
Other objects and advantages of the invention will become readily apparent from the ensuing description.
DETAILED DESCRIPTION OF THE INVENTION
The present invention involves the creation of activated carbons from nutshells, which possess enhanced adsorption ability with regard to metal ions. The carbon source for the activated carbons of the present invention may be any nutshell. Exemplary shell materials include almond, pecan, walnut, hazelnut, macadamia nut, coconut and pistachio; with walnut, macadamia nut and pecan shells being preferred.
According to the present invention, the nutshell material is concurrently activated and oxidized. Activation is achieved by chemical means utilizing phosphoric acid. Chemical activation is accomplished by first contacting the lignocellulosic nutshell material with an aqueous solution of phosphoric acid, under conditions and for sufficient time, such that the lignocellulosic material has entrained substantially all the acid it is capable of. This is, for example, accomplished by a process involving an initial cold soak of the nutshell material in an aqueous solution of phosphoric acid, followed by a two-stepped heating of the nutshell-acid mixture so as to drive the acid into the lignocellulosic structure.
Solution temperature constraints applicable to the initial soak are governed by transport phenomena involving the reduction of diffusive processes at lower temperatures and the loss of water, with an incumbent reduction in acid solvation, at temperatures approaching the solution boiling point. With this in mind, useable temperatures for the saturated solution range from about 20° C. to about 90° C., with a preferred range of about 60° C. to about 80° C. Concentration of the phosphoric acid in the aqueous medium may range from about 5% to about 60% by weight of the solution, with a preferred range of about 25% to about 55% by weight of the solution. The amount of solution utilized in relation to the nutshell material is dependent upon the concentration of phosphoric acid therein; mass ratios of acid:nutshell utilized may range from about 0.5:1 to about 1.2:1, preferably about 0.8:1 to about 1:1. Contact time during this soaking stage should be greater than about 1 hour, preferably greater than about 1.5 hours. While no maximum effective contact time is seen to exist, times in excess of approximately 2 hours are not believed to result in any appreciable benefit. Particle size of the nutshell material utilized affects the rate and degree of achievable acid perfusion. In order to achieve penetration of the acid throughout the nutshell material, particle size for the aforementioned conditions should be no larger than US 10 mesh. There is no effective limit to the minimum useable particle size, however, if a granular type product is desired, then it should be no smaller than about US 80 mesh.
Subsequent to the soaking step, the nutshell-acid mixture is then heated in an oxidizing atmosphere, such as that provided by air, to a temperature ranging from about 160° C. to about 180° C. for a period ranging from about 0.5 to about 1 hour. During this step the water is evaporated from the mixture. While not wishing to be bound thereto, it is applicants' theory that, as an effect of the absorbed water molecules being driven out of the lignocellulosic matrix of the nutshell material, a positive driving force is created to absorb additional acid into the structural voids of the nutshell to occupy the space vacated by the water molecules.
The activation process is completed by subjecting the acid-entrained granules to a further heating step under an oxidizing atmosphere, such as air. Temperatures utilized range from about 350° C. to about 550° C., preferably about 400° C. to about 475° C., and times utilized range from about 0.6 hours to about 3 hours, preferably about 1.0 to about 1.5 hours. While not wishing to be bound thereto, it is theorized that the entrained acid, under the physical conditions of the higher temperature regime, acts in a catalytic capacity to assist in the dual functions of creating a cross-linked carbon skeleton, as well as removing organic materials from the carbon lattice through chemical degradation; thus increasing the porosity of material.
During the activation process, the carbon material undergoes concurrent oxidation through its being exposed to air at the elevated temperatures associated with the activation reaction. Subsequent to the concurrent activation and oxidation of the nutshell carbons, the carbon material may be equilibrated to room temperature under an oxidizing atmosphere such as air. This serves to increase the degree of oxidation for the nutshell carbon. The oxidation of the carbon brings about the formation of polar functional groups on the meso- and macro-pores of the carbonized material. It is theorized that these are instrumental in the ability of the carbon to adsorb metal cations such as those selected from the group consisting of Cu(II), Zn(II), Ni(II), Cd(II), Pb(II), Cr(III), Hg(II), Fe(II), Fe (III), Au(I), Ag(I), V(IV), V(V), U(IV), Pu(IV), Cs(I), Sr(II), Al(III), Co(II), and Sn(II), and Sn(IV).
Prior to utilization the carbons created are washed by any means known in the art for the purpose of extracting any acid retained by the carbons at the completion of the oxidation step. While the degree of acid removal desired would be within the purview of the skilled artisan, and be dependent upon situational factors, it is applicant's preference to carry out the wash step until there is no measurable phosphate content in the wash solution as determined by titration with lead nitrate [Pb(NO 3 ) 2 ].
The following examples are intended to further illustrate the invention and are not intended to limit the scope of the invention which is defined by the claims.
All percentages herein disclosed are by weight unless otherwise specified.
EXAMPLE 1
Shells from almond, black walnut and English walnut, were ground and sieved to a 10×20 mesh (US sieve) particle and mixed in a 1:1 wt ratio with 50 wt % H 3 PO 4 and allowed to soak for 2 hours at room temperature. The samples were placed in a pyrolysis furnace (Grieve Corporation, Round Lake, Ill.), and flushed with breathing grade air (flowrate=0.1 m 3 /h). The samples were heated to 170° C. (±10° C.) where they were held for 0.5 hours (T1). After this low temperature treatment (LTT), they were exposed to a higher heat treatment temperature (HTT) of 450° C. (±5° C.) where they were held for 1 hour (T2). The samples were then allowed to cool to room temperature in an atmosphere of breathing grade air.
After concurrent acid-activation and oxidation the samples were rinsed in a soxhlet extractor with distilled water until the pH was at or near neutral. A small sample of the wash water, as well as the washed carbon (in approximately 50 ml of distilled water) were boiled separately and after cooling assayed with an 0.08 M Pb(NO 3 ) 2 solution to determine the presence of any residual free or loosely bound phosphate. Since this phosphate could conceivably bind with some of the metals in solution, and precipitate them out, the carbons were made phosphate-free. If lead phosphate precipitate appeared in the test sample, then the carbon was washed for a longer period of time until no precipitate was observed. For these samples, approximately 50 g of carbon washed for 24 hours in this manner usually had no detectable phosphate.
The carbons were analyzed for metals uptake using a 10 mM solution of CuCl 2 which was made up in an 0.07 molal sodium acetate--0.03 molal acetic acid buffer (pH 4.8). One gram of carbon was stirred for 24 hours in 100 ml of the metal solution. The pH of the slurry was recorded at the start and at the end of the experiment. An aliquot of the solution was drawn off in a disposable syringe, then filtered through an 0.22 mm micrometer Millipore filter (Millipore Corp., Bedford, Mass.), to remove any carbon particles. The sample was diluted 1:10 by volume with 4 vol % HNO 3 (Ultrapure, ICP grade) and analyzed by inductively coupled plasma (ICP) spectroscopy using a Leeman Labs Plasma-Spec I sequential ICP (Leeman Labs, Inc., Lowell, Mass.).
Product yields were calculated by the following equation:
Product yield (%)=[(wt.sub.f /wt.sub.i)×100]
where wt i =weight of shells before acid soak, and wt f =weight of shell carbons after water wash.
The BET surface area measurements were obtained from nitrogen adsorption isotherms at 77° K. using a Micromeritics Gemini 2375 Surface Area Analyzer (Micromeritics Corp., Norcross, Ga.). Specific surface areas (S BET ) were taken, as in other studies from adsorption isotherms using the BET equation.
The carbons produced from the protocol described above were characterized in terms of product yield, surface area and copper adsorption and were compared to several commercial carbons for copper uptake. The results are presented in Table
TABLE 1______________________________________Select properties of nutshell carbons and a comparisonof copper adsorption with commercial carbons Product Surface Area Cu2+Nutshell Yield (S.sub.BET), adsorbedor Carbon (%) m2/g (mmoles/g)______________________________________Almond 30 1308 0.93Black Walnut 39 1339 0.84English Walnut 38 1281 0.89Filtrasorb 400.sup.a -- 960 0.17Filtrasorb 200 -- 790 0.15TOG -- 720 0.15Centaur -- 720 0.13GRC-20 -- 870 0.19Vapure -- 970 0.14RO 3515 -- 920 0.22______________________________________ .sup.a Seven commercial carbons were evaluated. They are representative o carbons made from bituminous coal, coconut shells and peat, and are used to remove both metals and organic compounds from air and aqueous media. Thus, they represent a crosssection of carbons available for commercial water and airtreatment systems.
EXAMPLE 2
Shells from almond, black walnut or English walnut were ground to 10×20 mesh particle size, and mixed in a 1:1 wt ratio with 50 wt % H 3 PO 4 and allowed to soak for 2 hours at room temperature. The protocol given in Example 1 was followed with the following difference: after the nutshell carbons were concurrently activated and oxidized, they were removed from the furnace and quenched in distilled, deionized water. This immediately brought the carbons to room temperature instead of the much slower cool-down to room temperature in the furnace as noted in Example 1.
The results of treating nutshells by this protocol are given in Table
TABLE 2______________________________________Select properties of nutshell carbons and a comparisonof copper adsorption with commercial carbons. Product Surface Area Cu2+Nutshell Yield (S.sub.BET), adsorbedor Carbon (%) m2/g (mmoles/g)______________________________________Almond 32 1458 0.69Black Walnut 37 1693 0.55English Walnut 32 1642 0.63Filtrasorb 400.sup.a -- 960 0.17Filtrasorb 200 -- 790 0.15TOG -- 720 0.15Centaur -- 720 0.13GRC-20 -- 870 0.19Vapure -- 970 0.14RO 3515 -- 920 0.22______________________________________ .sup.a The same commercial carbons were compared as in Table 1.
EXAMPLE 3
Shells of almonds, macadamia nuts or pecans of 10×20 mesh size were mixed in a 1:1 wt ratio with 50 wt % H 3 PO 4 and allowed to soak for 2 hours at room temperature. The protocol given in Example 2 was followed except that the nutshells were not exposed to the LTT. After the shells were placed in the furnace, the temperature was increased to 450° C. (±5° C.), where they were held for 1 hour. The protocol presented in Examples 1 and 2 were then carried out. The results of treating nutshells by this protocol are shown in Table
TABLE 3______________________________________Select properties of nutshell carbons and a comparisonof copper adsorption with commercial carbons. Product Surface Area Cu2+Nutshell Yield (S.sub.BET), adsorbedor Carbon (%) m2/g (mmoles/g)______________________________________Almond 32 1483 0.56Macadamia 39 1604 0.58Pecan 35 1639 0.52Filtrasorb 400.sup.a -- 960 0.17Filtrasorb 200 -- 790 0.15TOG -- 720 0.15Centaur -- 720 0.13GRC-20 -- 870 0.19Vapure -- 970 0.22RO 3515 -- 920 0.22______________________________________ .sup.a The same commercial carbons were compared as in Table 1.
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Activated carbons derived from nutshells, and for use in adsorption of metallic cations, are prepared utilizing phosphoric acid activation with concurrent oxidation under air. The acid activation is carried out utilizing a one or two-step heating regime subsequent to the infusion of the phosphoric acid into the nutshell material during which concurrent oxidation is achieved by exposure to atmospheric oxygen. Further oxidation is optionally achieved by equilibration of the nutshell carbons to room temperature under air. Prior to utilization, a washing step is employed to remove unwanted acid from the carbon product.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the May 20, 2013 Priority Date benefit of Provisional Application No. 61/855,660.
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 the earthboring arts. More particularly, the invention relates to methods and devices for severing drill pipe, casing and other massive tubular structures by the remote detonation of an explosive cutting charge.
[0005] 2. Description of Related Art
[0006] Deep well earthboring for gas, crude petroleum, minerals and even water or steam requires tubes of massive size and wall thickness. Tubular drill strings may be suspended into a borehole that penetrates the earth's crust several miles beneath the drilling platform at the earth's surface. To further complicate matters, the borehole may be turned to a more horizontal course to follow a stratification plane.
[0007] The operational circumstances of such industrial enterprise occasionally presents a driller with a catastrophe that requires him to sever his pipe string at a point deep within the wellbore. For example, a great length of wellbore sidewall may collapse against the drill string causing it to wedge tightly in the well bore. The drill string cannot be pulled from the well bore and in many cases, cannot even be rotated. A typical response for salvaging the borehole investment is to sever the drill string above the obstruction, withdraw the freed drill string above the obstruction and return with a “fishing” tool to free and remove the wedged portion of drill string.
[0008] Drill string weight bearing on the drill bit necessary for advancement into the earth strata is provided by a plurality of specialty pipe joints having atypically thick annular walls. In the industry vernacular, these specialty pipe joints are characterized as “drill collars”. A drill control objective is to support the drill string above the drill collars in tension. Theoretically, only the weight of the drill collars bears compressively on the drill bit. With a downhole drilling motor configured for deviated bore hole drilling, the drill motor, bent sub and drill bit are positioned below the drill collars. This drill string configuration does not rotate in the borehole above the drill bit. Consequently, the drill collar section of the drill string is particularly susceptible to borehole seizures and because of the drill collar wall thickness, is also difficult to cut.
[0009] When an operational event such as a “stuck” drill string occurs, the driller may use wireline suspended instrumentation that is lowered within the central, drill pipe flow bore to locate and measure the depth position of the obstruction. This information may be used to thereafter position an explosive severing tool within the drill pipe flow bore.
[0010] Typically, an explosive drill pipe severing tool comprises a significant quantity, 800 to 1,500 grams for example, of high order explosive such as RDX, HMX or HNS. The explosive powder is compacted into high density “pellets” of about 22.7 to about 38 grams each. The pellet density is compacted to about 1.6 to about 1.65 gms/cm 3 to achieve a shock wave velocity greater than about 30,000 ft/sec, for example. A shock wave of such magnitude provides a pulse of pressure in the order of 4×10 6 psi. It is the pressure pulse that severs the pipe.
[0011] In one form, the pellets are compacted at a production facility into a cylindrical shape for serial, juxtaposed loading at the jobsite as a column in a cylindrical barrel of a tool cartridge. Due to weight variations within an acceptable range of tolerance between individual pellets, the axial length of explosive pellets fluctuates within a known tolerance range. Furthermore, the diameter-to-axial length ratio of the pellets is such that allows some pellets to wedge in the tool cartridge barrel when loaded. For this reason, a go-no-go type of plug gauge is used by the prior art at the end of a barrel to verify the number of pellets in the tool barrel. In the frequent event that the tool must be disarmed, the pellets may also wedge in the barrel upon removal. A non-sparking depth-rod is inserted down the tool barrel to verify removal of all pellets.
[0012] Extreme well depth is often accompanied by extreme hydrostatic pressure. Hence, the drill string severing operation may need to be executed at 10,000 to 20,000 psi. Such high hydrostatic pressures tend to attenuate and suppress the pressure of an explosive pulse to such degree as to prevent separation.
[0013] One prior effort by the industry to enhance the pipe severing pressure pulse and overcome high hydrostatic pressure suppression has been to detonate the explosive pellet column at both ends simultaneously. Theoretically, simultaneous detonations at opposite ends of the pellet column will provide a shock front from one end colliding with the shock front from the opposite end within the pellet column at the center of the column length. On collision, the pressure is multiplied, at the point of collision, by about 4 to 5 times the normal pressure cited above. To achieve this result, however, the detonation process, particularly the simultaneous firing of the detonators, must be timed precisely in order to assure collision within the explosive column at the center.
[0014] Such precise timing is typically provided by means of mild detonating fuse and special boosters. However, if fuse length is not accurate or problems exist in the booster/detonator connections, the collision may not be realized at all and the device will operate as a “non-colliding” tool with substantially reduced severing pressures.
[0015] The reliability of state-of-the-art severing tools is further compromised by complex assembly and arming procedures required at the well site. With those designs, regulations require that explosive components (detonator, pellets, etc.) must be shipped separately from the tool body. Complete assembly must then take place at the well site under often unfavorable working conditions.
[0016] Finally, the electric detonators utilized by many state-of-the-art severing tools are vulnerable to electric stray currents and uncontrolled RF energy sources thereby further complicating the safety procedures that must be observed at the well site.
SUMMARY OF THE INVENTION
[0017] The pipe severing tool of the present invention comprises an outer housing that is a metallic tube of such outside diameter that is compatible with the drill pipe flow bore diameter intended for use. The lower end of the housing tube is sealed with a nose plug. The inside transverse surface of the nose plug is preferably faced with shock absorbers in the form of silicon washers. The housing upper end is plugged with a detonation booster carrier. The inside face of the booster carrier supports a pellet guide tube that extends along the housing tube axis for substantially the full length of the housing. At the distal end of the guide tube opposite from the booster carrier, a non-ferrous terminal is threaded into the internal bore of the guide tube.
[0018] A first bi-directional booster is secured within the guide tube bore at the booster carrier end. The first bi-directional booster secures the ends of two mild detonation cords within the bi-directional booster case proximate of a small quantity of explosive material. Both cords are of the same length. One cord continues along the axial bore of the guide tube to the terminal end of the guide tube. At the terminal end, the cord end is secured within the case of a second bi-directional booster. A first window aperture is provided in the guide tube wall adjacent to the second bi-directional booster.
[0019] The second mild detonation cord exits the guide tube bore through a second tube wall window proximate of the detonator carrier and is wound about a timing spool. A partition disc secured to the guide tube proximate of the lower end of the timing spool supports a third bi-directional booster. The lower end of the second detonation cord is secured within the case of the third booster.
[0020] With the housing tube separated from the detonator carrier and guide tube assembly and the guide tube terminal removed from the guide tube lower end, multiple pellets of explosive material are stacked along the length of the guide tube with the first pellet engaging the guide tube partition disc and third bi-directional booster. These pellets, each comprising a regulated weight quantity of explosive material powder, are pressed into an annular disc shape about an axially central aperture. The guide tube penetrates the axially central aperture. The outside diameter of the pellets corresponds to the inside diameter of the housing tube. The number of such pellets is determined by the severing objective.
[0021] For a given explosive pellet weight, dimensional parameters and pressed density, there will be thickness variations in individual pellets within tolerance limits. The first window aperture in the guide tube is positioned to be aligned between the second bi-directional booster and that explosive pellet at the lower distal end of the pellet column. The axial length of the window, however, should accommodate the cumulative length of the stacked explosive-column considering the tolerance limits.
[0022] With the predetermined number of explosive pellets in place along the guide tube length and the last or end-most pellet surrounding the first guide tube window, any exposed length between the last pellet and the distal end of the guide tube is filled with one or more resilient spacers. The guide tube end terminal is attached and the explosive assembly inserted into the hollow bore of the housing tube
[0023] A bi-directional booster is positioned in the detonator carrier and armed for activation. The carrier and armed severing tool is attached to the well delivery string, such as tubing, and appropriately positioned within the well for discharge.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The advantages and further features of the invention will be readily appreciated by those of ordinary skill in the art as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference characters designate like or similar elements throughout.
[0025] FIG. 1 is a sectional view of the invention as assembled for operation.
[0026] FIG. 2 is an enlargement of the FIG. 1 Detail A.
[0027] FIG. 3 is an enlargement of the FIG. 1 Detail B.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] As used herein, the terms “up” and “down”, “upper” and “lower”, “upwardly” and downwardly”, “upstream” and “downstream”; “above” and “below”; and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly describe some embodiments of the invention. However, when applied to equipment and methods for use in wells that are deviated or horizontal, such terms may refer to a left to right, right to left, or other relationship as appropriate. Moreover, in the specification and appended claims, the terms “pipe”, “tube”, “tubular”, “casing”, “liner” and/or “other tubular goods” are to be interpreted and defined generically to mean any and all of such elements without limitation of industry usage.
[0029] Referring to the FIG. 1 cross-sectional view of the invention, a tubular outer housing 10 includes an internal bore 11 . The internal bore 11 is sealed at its lower end by a nose plug 14 . The interior face of the nose plug is cushioned with a resilient padding 15 such as silicon gel.
[0030] The upper end of the internal bore 11 is sealed by a top carrier plug 12 . An internal cavity 13 in the top carrier plug 12 is formed to receive a firing head not shown. Guide tube 16 is secured to the top plug 12 to project from the inside face 38 of the plug 12 along the housing 10 axis. The opposite distal end of guide tube 16 supports a guide tube terminal 18 which may be a disc having a diameter slightly less than the inside diameter of the housing internal bore 11 . A threaded boss 19 secures the terminal 18 to the guide tube 16 . One or more resilient spacers 42 , such as silicon gel washers, are positioned to encompass the guide tube 16 and bear against the upper face of the terminal 18 .
[0031] Near the upper end of the guide tube 16 is an adjustably positioned partition disc 20 secured by a set screw 21 . Between the partition disc 20 and the inside face 38 of the top plug 12 is a timing spool 22 . Preferably, the partition disc 20 and timing spool are axially juxtaposed.
[0032] Internally of the guide bore 16 , at the upper end thereof, is first bi-directional booster 24 having a pair of mild detonating cords 30 and 32 secured within detonation proximity to a small quantity of explosive material 25 . It is important that both detonation cords 30 and 32 are of the same length so as to detonate opposite ends of the explosive 40 column at the same moment. The first detonating cord 30 continues along the guide tube 16 bore to be secured within the second bi-directional booster 26 proximate of explosive material 27 . A first window aperture 34 in the wall of guide tube 16 is cut opposite of the booster 26 .
[0033] From the first bi-directional booster 24 , the second detonating cord 32 is threaded through a second window aperture 36 in the upper wall of guide tube 16 and around the helical surface channels off the timing spool 22 . Characteristically, the timing spool outside cylindrical surface is helically channeled to receive a winding lay of detonation cord with insulating material separations between adjacent wraps of the cord. The distal end of second detonating cord 32 terminates in a third bi-directional booster 28 that is set within a receptacle in the partition disc 20 .
[0034] Preferably, the position of the partition disc 20 is adjustable along the length of the guide tube 16 to accommodate the anticipated number of explosive pellets 40 to be loaded.
[0035] For loading, the top plug 12 , guide tube 16 and guide tube terminal 18 are withdrawn from the housing bore 11 as an assembled unit. While out of the housing bore 11 , the guide tube terminal 18 is removed along with the resilient spacers 42 .
[0036] Pellets 40 of powdered, high explosive material such as RDX, HMX or HNS are pressed into narrow wheel shapes often characterized by the industry vernacular as “pellets”. A central aperture is provided in each pellet to receive the guide tube 16 therethrough. The pellets are loaded serially in a column along the guide tube 16 length with the first pellet in juxtaposition against the lower face of partition disc 20 and in detonation proximity with the third bi-directional booster 28 . The last pellet most proximate of the terminus 18 is positioned adjacent to the first window aperture 34 in the tube guide tube wall
[0037] Transportation safety limits the total weight of explosive in each pellet, generally, to less than 38 grams, for example. When pressed to a density of about 1.6 to about 1.65 gms/cm 3 , pellet diameter, determines the pellet thickness within a determinable limit range. Accordingly, a predetermined total weight of explosive will determine the total number of pellets 40 to be aligned along the guide tube 16 . From this data, the necessary length of the guide tube 16 to accommodate the requisite number of pellets is determinable to position the last pellet on the column adjacent the detonation window 34 . Any space remaining between the face of the bottom-most pellet and the guide tube terminal 18 due to fabrication tolerance variations may be filled with resilient spacers 42 .
[0038] Numerous modifications and variations may be made of the structures and methods described and illustrated herein without departing from the scope and spirit of the invention disclosed. Accordingly, it should be understood that the embodiments described and illustrated herein are only representative of the invention and are not to be considered as limitations upon the invention as hereafter claimed.
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A pipe severing tool is arranged to align a plurality of high explosive pellets along a unitizing central tube that is selectively separable from a tubular external housing. The pellets are loaded serially in a column in full view along the entire column as a final charging task. Detonation boosters are pre-positioned and connected to detonation cord for simultaneous detonation at opposite ends of the explosive column. Devoid of high explosive pellets during transport, the assembly may be transported with all boosters and detonation cord connected.
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BACKGROUND
[0001] As the computing power of mobile devices increase more sophisticated applications can be developed to utilize these resources. Typically a provider of such a mobile device may want to protect the device from attackers that try and obtain digital rights management keys or device keys. One way to secure the device is to ‘close’ the mobile device, e.g., manufacture the device in such a way as to only allow a certain type of hardware and proprietary closed source software. By closing the mobile device the provider can provide some level of security by making it more likely than not that only approved code and hardware is used in the device.
[0002] While closing the mobile device may make it more difficult for an attacker to compromise the device, a provider may want to allow third parties to have some ability to develop applications. A provider may allow for some third party code to execute on a closed mobile device by providing a sandbox that verifies third party code at runtime, or by configuring the operating system of the device to segregate third party code from kernel mode code. While these techniques exist, there is a need for alternative techniques that can augment or supplement the typical security measures that require less computational power from the mobile device and enable the provider to have more control over how third party code is treated by the device.
SUMMARY
[0003] An embodiment of the present disclosure provides a method that includes, but is not limited to granting, to a managed library, access to native resources of an operating system in response to validating a digital certificate associated with the managed library; and denying, to a managed application, access to native resources of the operating system, wherein the managed application includes a digital certificate authorizing the managed application to access a specific native resource of the operating system through the managed library. In addition to the foregoing other method aspects are described in the detailed description, drawings, and claims that form the present disclosure.
[0004] An embodiment of the present disclosure provides a method that includes, but is not limited to receiving, by a manager, a request from a managed application to access a native system resource through a managed library; authorizing, by the manager, the request to access the native system resource through the managed library, wherein the manager includes information that identifies managed libraries that the managed application is authorized to access, further wherein the manager is effectuated by native instructions; authorizing, by the manager, the request to access the native system resource by the managed library, wherein information that identifies that the managed library is authorized to access the native system resource was obtained from a digital certificate associated with the managed library; sending, by the managed library, a request to access the native system resource to a runtime host, wherein the runtime host is effectuated by native instructions; and accessing, by the runtime host, the native system resource. In addition to the foregoing other method aspects are described in the detailed description, drawings, and claims that form the present disclosure.
[0005] An embodiment of the present disclosure provides a method that includes, but is not limited to receiving a package from a networked computer system; identifying an executable in the package; verifying managed metadata associated with the executable, wherein the managed metadata describes the structure of executable, further wherein verifying the managed metadata includes inspecting the managed metadata at runtime to determine that the executable includes type safe code; sending, by the managed library, a request to access the native system resource to a runtime host, wherein the runtime host is effectuated by native instructions; and accessing, by the runtime host, the native system resource. In addition to the foregoing other method aspects are described in the detailed description, drawings, and claims that form the present disclosure.
[0006] It can be appreciated by one of skill in the art that one or more various aspects of the disclosure may include but are not limited to circuitry and/or programming for effecting the herein-referenced aspects of the present disclosure; the circuitry and/or programming can be virtually any combination of hardware, software, and/or firmware configured to effect the herein-referenced aspects depending upon the design choices of the system designer.
[0007] The foregoing is a summary and thus contains, by necessity, simplifications, generalizations and omissions of detail. Those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 depicts exemplary general purpose computing system.
[0009] FIG. 2 illustrates an example environment wherein aspects of the present disclosure can be implemented.
[0010] FIG. 3 illustrates an example container.
[0011] FIG. 4 it illustrates an example mobile device that can be used in embodiments of the present disclosure.
[0012] FIG. 5 depicts an example arbitration layer that can be used to implement aspects of the present disclosure.
[0013] FIG. 6 depicts an example operational procedure related to securing a computing device.
[0014] FIG. 7 depicts an alternative embodiment of the operational procedure of FIG. 6 .
[0015] FIG. 8 depicts an example operational procedure related to protecting a closed computing device from executing un-trusted instructions.
[0016] FIG. 9 depicts an alternative embodiment of the operational procedure of FIG. 8 .
[0017] FIG. 10 depicts an alternative embodiment of the operational procedure of FIG. 9 .
[0018] FIG. 11 depicts an alternative embodiment of the operational procedure of FIG. 9 .
[0019] FIG. 12 depicts an example operational procedure related to publishing videogames configured to execute on a mobile device.
[0020] FIG. 13 depicts an alternative embodiment of the operational procedure of FIG. 12 .
DETAILED DESCRIPTION
[0021] Numerous embodiments of the present disclosure may execute on a computer. FIG. 1 and the following discussion is intended to provide a brief general description of a suitable computing environment in which the disclosure may be implemented. One skilled in the art can appreciate that the computer system of FIG. 1 can in some embodiments effectuate the validation system 212 , the community feedback server 206 , the electronic market place 222 , developer 204 , and peer reviewers 208 and 210 . One skilled in the art can also appreciate that the elements depicted by FIG. 2-5 can include circuitry configured to instantiate specific aspects of the present disclosure. For example, the term circuitry used through the disclosure can include specialized hardware components configured to perform function(s) implemented by firmware or switches. In other example embodiments the term circuitry can include a general purpose processing unit configured by software instructions that embody logic operable to perform function(s). In example embodiments where circuitry includes a combination of hardware and software, an implementer may write source code embodying logic that can be compiled into machine readable code and executed by a processor. Since one skilled in the art can appreciate that the state of the art has evolved to a point where there is little difference between hardware, software, or a combination of hardware/software and the selection of hardware versus software to effectuate specific functions is a design choice left to an implementer. More specifically, one of skill in the art can appreciate that a software process can be transformed into an equivalent hardware structure, and a hardware structure can itself be transformed into an equivalent software process. Thus, the selection of a hardware implementation versus a software implementation is one of design choice.
[0022] Referring now to FIG. 1 , an exemplary general purpose computing system is depicted. The general purpose computing system can include a conventional computer 20 or the like, including a processing unit 21 , a system memory 22 , and a system bus 23 that couples various system components including the system memory to the processing unit 21 . The system bus 23 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. The system memory includes read only memory (ROM) 24 and random access memory (RAM) 25 . A basic input/output system 26 (BIOS), containing the basic routines that help to transfer information between elements within the computer 20 , such as during start up, is stored in ROM 24 . The computer 20 may further include a hard disk drive 27 for reading from and writing to a hard disk, not shown, a magnetic disk drive 28 for reading from or writing to a removable magnetic disk 29 , and an optical disk drive 30 for reading from or writing to a removable optical disk 31 such as a CD ROM or other optical media. In some example embodiments computer executable instructions embodying aspects of the present disclosure may be stored in ROM 24 , hard disk (not shown), RAM 25 , removable magnetic disk 29 , optical disk 31 , and/or a cache of processing unit 21 . The hard disk drive 27 , magnetic disk drive 28 , and optical disk drive 30 are connected to the system bus 23 by a hard disk drive interface 32 , a magnetic disk drive interface 33 , and an optical drive interface 34 , respectively. 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 20 . Although the exemplary environment described herein employs a hard disk, a removable magnetic disk 29 and a removable optical disk 31 , it should be appreciated by those skilled in the art that other types of computer readable media which can store data that is accessible by a computer, such as magnetic cassettes, flash memory cards, digital video disks, Bernoulli cartridges, random access memories (RAMs), read only memories (ROMs) and the like may also be used in the exemplary operating environment.
[0023] A number of program modules may be stored on the hard disk, magnetic disk 29 , optical disk 31 , ROM 24 or RAM 25 , including an operating system 35 , one or more application programs 36 , other program modules 37 and program data 38 . A user may enter commands and information into the computer 20 through input devices such as a keyboard 40 and pointing device 42 . Other input devices (not shown) may include a microphone, joystick, game pad, satellite disk, scanner or the like. These and other input devices are often connected to the processing unit 21 through a serial port interface 46 that is coupled to the system bus, but may be connected by other interfaces, such as a parallel port, game port or universal serial bus (USB). A display 47 or other type of display device can also be connected to the system bus 23 via an interface, such as a video adapter 48 . In addition to the display 47 , computers typically include other peripheral output devices (not shown), such as speakers and printers. The exemplary system of FIG. 1 also includes a host adapter 55 , Small Computer System Interface (SCSI) bus 56 , and an external storage device 62 connected to the SCSI bus 56 .
[0024] The computer 20 may operate in a networked environment using logical connections to one or more remote computers, such as a remote computer 49 . The remote computer 49 may be another computer, a server, a router, a network PC, a peer device or other common network node, and typically can include many or all of the elements described above relative to the computer 20 , although only a memory storage device 50 has been illustrated in FIG. 1 . The logical connections depicted in FIG. 1 can include a local area network (LAN) 51 and a wide area network (WAN) 52 . Such networking environments are commonplace in offices, enterprise wide computer networks, intranets and the Internet.
[0025] When used in a LAN networking environment, the computer 20 can be connected to the LAN 51 through a network interface or adapter 53 . When used in a WAN networking environment, the computer 20 can typically include a modem 54 or other means for establishing communications over the wide area network 52 , such as the Internet. The modem 54 , which may be internal or external, can be connected to the system bus 23 via the serial port interface 46 . In a networked environment, program modules depicted relative to the computer 20 , or portions thereof, may be stored in the remote memory storage device. It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used. Moreover, while it is envisioned that numerous embodiments of the present disclosure are particularly well-suited for computerized systems, nothing in this document is intended to limit the disclosure to such embodiments.
[0026] Referring now to FIG. 2 , it generally illustrates an example environment wherein aspects of the present disclosure can be implemented. One skilled in the art can appreciate that the example elements depicted by FIG. 2 provide an operational framework for describing the present disclosure. Accordingly, in some embodiments the physical layout of the environment may be different depending on different implementation schemes. Thus the example operational framework is to be treated as illustrative only and in no way limit the scope of the claims.
[0027] FIG. 2 illustrates an example electronic ecosystem 214 that can be managed by an ecosystem provider, e.g., a company. The electronic ecosystem 214 can be implemented so that application developers such as developer 204 can create applications for mobile devices such as mobile device 200 and remote mobile device 202 . Generally, a developer 204 can in an example embodiment have access to a computer system that can include components similar to those described in FIG. 1 . The developer 204 can in this example embodiment obtain a software development kit from the ecosystem provider by registering with the provider and/or pay a fee. Once the developer 204 obtains the software development kit it can be installed and used to enhance the design, development, and management of applications, e.g., videogames, word processing programs, etc. The software development kit in an example embodiment can include a large library of useful functions that are provided in order to increase code reuse across projects. For example, in an embodiment the software development kit can be thought of as the skeleton that provides libraries that enable low level functions. This type of software development kit allows developers to concentrate on developing their application instead of working out the low level details of coding for a specific machine environment. In an embodiment the applications and libraries can be developed in an intermediate language that is separate from any native instruction set of a processor. The software development kit can be used to generate applications in this intermediate language that execute in a software environment that manages the application's runtime requirements. The software environment can include a runtime, e.g., a virtual machine, that manages the execution of programs by just in time converting the instructions into native instructions that could be processed by the processor.
[0028] Once the application is developed a compiled version of it can be submitted to a validation system 212 that can be maintained by the ecosystem provider. For example, in an embodiment the application can be transmitted to the ecosystem provider as a package of assemblies, e.g., executables, libraries obtained from the software development kit, and any libraries developed for the application by the developer 204 . Generally, the validation system 212 can in an embodiment include circuitry for a file parser 216 , a verification system 218 , and a signing system 220 each of which can include components similar to those described in FIG. 1 . For example, file parser 216 can in one embodiment include circuitry, e.g., a processor configured by a program, for identifying assemblies that include executables. In this example embodiment the instructions of the application submitted by the developer 204 can be verified and stored in a container that includes a digital signature.
[0029] Once the application is verified it can be submitted to a community feedback server 206 . The community feedback server 206 can generally be configured to store newly developed applications and transmit the new applications to peer reviewers 208 and 210 in response to requests. In at least one example embodiment the peer reviewers 208 can add to the application by downloading the source code of the application and use a copy of the software development kit to add to the application. In this example if the application includes more than source code then the validation system 212 may be invoked before it can be redistributed to peer reviewers.
[0030] After the application is verified it can be stored in an electronic market place 222 that can also include components similar to those described in FIG. 1 . The electronic market place 222 can additionally include circuitry configured to sell copies of the application to members of the public. The electronic market place 222 can be configured to transmit the application in the container to either the mobile device 200 over a wireless/wired network connection or to a computer (not shown) where it can then be transmitted to the mobile device over a local connection.
[0031] Referring now to FIG. 3 , it illustrates an example container 300 that can be transmitted to the mobile device 200 from an electronic market place 222 . For example, in an embodiment of the present disclosure each application can be stored in its own container 300 . The container 300 in an embodiment can be an electronic wrapper and the information inside the wrapper can be signed with a private key by the signing system 220 of FIG. 2 . In this example, the signing system 220 can embed a digital signature 306 in the container 300 so that the mobile device 200 can determine that the container 300 is authentic. Continuing with the description of FIG. 3 , the container 300 in this example may contain one or more assemblies such as assemblies 302 - 304 . For example, in an embodiment of the present disclosure the software development kit can be used to generate software packages for a given platform. The assemblies 302 - 304 in this example can effectuate the application and contain information that can be used by a runtime to find, locate, and execute the application on the platform. As is illustrated by FIG. 3 , in one embodiment each assembly can include intermediate language instructions 310 , e.g., machine independent partially compiled code, and metadata 308 that describes the intermediate language instructions. The metadata in an embodiment can describe every type and member defined in the intermediate language instructions in a language-neutral manner so as to provide information about how the assembly works.
[0032] Continuing with the description of FIG. 3 , in an embodiment of the present disclosure an assembly may include a certificate 312 . For example, the certificate 312 is indicated in dashed lines which are indicative of the fact that only certain assemblies may include certificates in embodiments of the present disclosure. For example, the ecosystem provider may only embed certificates in assemblies that were developed by the ecosystem provider. In other example embodiments the ecosystem provider may embed certificates in assemblies that were coded by a trusted third party, e.g., a company that the ecosystem provider has a business relationship with. The certificate 312 in embodiments of the present disclosure can be used by the mobile device 200 to determine whether the instructions that effectuate an assembly have been scrutinized by the ecosystem provider to ensure that the assembly can not be used in a malicious way and, for example, determine which managed libraries can be called by the application. A certificate in embodiments of the present disclosure can be similar to a digital signature; however in certain instances the certificate can convey different information than the digital signature, e.g., a certificate may indicate a resource permission level for the assembly whereas the signature may be used as a source identifier.
[0033] Referring now to FIG. 4 , it illustrates an example mobile device 200 that can be used in embodiments of the present disclosure. For example, mobile device 200 can include a mobile phone, a personal data assistant, or a portable media player, e.g., a mobile device configured to store and play digital content such as video, audio, and/or execute applications. As was mentioned above, a major concern with opening up a mobile device 200 to third party applications is that an attacker could attempt to compromise the mobile device 200 in order to obtain DRM keys, device keys, user data and the like. Generally, in some closed mobile devices the software stored on mobile device 200 can be considered native, e.g., the instructions can be written to run on the physical processor of hardware 402 and if an individual could access the native code they could potentially access any information the device stores. In closed mobile devices the native code is protected by scrutinizing the code prior to commercializing the product, e.g., by inspecting the code to determine that it does not include anything that could be exploited to compromise and/or damage the mobile device 200 , and coding the native software in such a way to prevent the mobile device 200 from executing any third party code. The ecosystem provider can ensure that the mobile device 200 does not execute third party code by checking the authenticity of each piece of software prior to allowing it to execute. If any portion of the system software can't be authenticated, the mobile device 200 can be configured to refuse to startup. For example, when the mobile device 200 is powered on a boot loader stored in hardware 402 can be authenticated, e.g., a digital signature of the boot loader can be checked. The boot loader can in turn authenticate and load the operating system 404 . The operating system 404 in this example embodiment can include an audio driver 416 , a secured store 418 , e.g., a secured area of memory that includes device secrets, a network driver 420 , and a graphics driver 422 . The operating system 404 in turn can authenticate native application program interfaces used to invoke operating system methods, the shell 408 , e.g., the user interface of the operating system, and a title player 410 , e.g., a native executable that launches applications and hosts them within its process.
[0034] As depicted by FIG. 4 , in an embodiment the preceding portion of the components of the mobile device 200 can be considered the trusted layer of software, e.g., native software developed by the ecosystem provider, that can be stored in firmware of the mobile device 200 . In embodiments of the present disclosure however the ecosystem provider may want to allow third party applications to execute on mobile device 200 . Since these third party applications were not developed by the ecosystem provider, and thus may not be been stored in the firmware of the mobile device 200 , a mechanism needs to be put in place to ensure that the managed application 412 are not given the same level of trust as the trusted software. Third party code may need to remain un-trusted because in at least one embodiment of the present disclosure the core functionality of the mobile device, e.g., graphics processing, networking, memory management, and/or audio, are implemented by operating system methods to improve system performance and the operating system itself may lack a way to gate access to the core functionality. Thus the ecosystem provider has to expose an interface to the operating system 404 and protect the interface from being accessed by malicious code. In order to prevent the managed application 412 from invoking native methods, or having unrestricted access to memory, an arbitration layer including a runtime framework 414 can be instantiated that gates access to the operating system 404 . In example embodiments of the present disclosure when a managed application 412 attempts to access an operating system resource the runtime framework 414 can be configured to determine whether the managed application 412 has permission to access such a resource and either allow or deny its request.
[0035] Referring now to FIG. 5 it depicts an example arbitration layer that can be used to implement aspects of the present disclosure. For example, FIG. 5 depicts a managed application 412 that can be, for example, a videogame, a word processing application, a personal information manager application or the like that can access native resources of the operating system 404 via at least one managed library. In order to invoke the functionality of the operating system 404 at least one managed library can be selectively exposed to the managed application 412 via a manager 516 that can be configured to restrict the third party application's access to resources other than those provided by one or more select libraries. In embodiments of the present disclosure, a managed library 514 can be dynamically loaded at runtime depending on what dependencies are required for the managed application 412 . In an embodiment the managed library 514 can be operable to access any native resource at runtime therefore the manager 516 needs to be configured in this example to deny a managed application's request to access native resources and restrict access to only but a few select managed libraries. As illustrated by FIG. 5 , the arbitration layer in this example embodiment can additionally include a runtime host 518 that can in certain embodiments be configured to call methods of the operating system 404 that actually implement the requests of the application.
[0036] Continuing with the description of FIG. 5 , in an embodiment title player 410 can be configured to load and authenticate runtime host 518 , manager 516 , managed library 514 , and managed application 412 . For example, in an embodiment runtime host 518 , manager 516 , and managed library 514 can each include digital signatures that can be authenticated by the title player 410 prior to execution to ensure that they had not been tampered with. The title player 410 can check a digital certificate for each managed assembly to determine what privileges they have prior to loading them. When the title player 410 loads a managed assembly, e.g., a part of the managed application 412 or a managed library 514 , it can be configured to check the assembly's certificate to determine what privileges to grant to it. In an embodiment each managed application 412 can include a certificate that is associated with a set of privileges, e.g., the certificate can itemize the rights or the certificate can reference a set of rights that can be stored in a table of the secured store 418 . The title player 410 can check the authenticity of the assembly and if it is legitimate the title player 410 can check the certificate to determine what privileges should be granted. The title player 410 can obtain a set of privileges and make them available to the manager 516 so that the manager 516 can enforce the privileges by selectively granting or denying a managed application's access requests to certain managed libraries 514 . In the same, or other embodiments, if a managed third party application lacks a certificate 312 the title player 410 can be configured to determine that it has no privileges and direct the manager 516 to prevent the assembly from invoking any native resources such as operating system methods or native libraries, as well as denying the use of any managed library 514 for which possession of such a certificate is required.
[0037] The following figures depict a series of flowcharts of processes. The flowcharts are organized such that the initial flowcharts present processes implementations via an overall “big picture” viewpoint. Those having skill in the art will appreciate that the style of presentation utilized herein (e.g., beginning with a presentation of a flowchart(s) presenting an overall view and thereafter providing additions to and/or further details in subsequent flowcharts) generally allows for a rapid and easy understanding of the various operational procedures.
[0038] Referring now to FIG. 6 , it illustrates example operations related to securing a computing device including operations 600 , 602 , and 604 . As is illustrated by FIG. 6 , operation 600 begins the operational procedure and operation 602 illustrates granting, to a managed library, access to native resources of an operating system in response to validating a digital certificate associated with the managed library. For example, and referring to FIG. 5 , in an embodiment of the present disclosure a managed library 514 can be granted access to native resources of an operating system. In this example the managed library 514 can be considered managed because the instructions that effectuate it can be executed within virtual machine such as the common language runtime or java virtual machine. The manager 516 can be configured to grant the managed library 514 access rights to a native operating system resource by allowing it to be loaded into main memory after verifying the authenticity of a digital certificate 312 . The digital certificate 312 can evidence that the managed library 514 includes scrutinized code that was developed by, for example, the ecosystem provider. In one embodiment the manager 516 can be configured to check the digital certificate 312 in order to protect the operating system 404 . The operating system in this example may not have the ability to protect itself from malicious attacks, e.g., the operating system 404 may not implement kernel mode and user mode permission levels. In this example embodiment the resources of the operating system 404 can be protected by a layer of security enforced by the manager 516 . In the same or other embodiments native instructions may have privileges to access any resource of the mobile device 200 and the operating system 404 may not have a native ability to enforce security policies. In this example embodiment if the native instructions were accessed by a malicious third party application then an attacker could potentially access any system resource such as a device key, a display driver, and/or damage the mobile device 200 . In another example embodiment the operating system 404 may include a native ability to protect itself. In this example the operating system 404 can be protected by an additional layer of security enforced by the manager 516 .
[0039] Continuing with the description of FIG. 6 , operation 604 illustrates denying, to a managed application, access to native resources of the operating system, wherein the managed application includes a digital certificate authorizing the managed application to access a specific native resource of the operating system through the managed library. For example, and in addition to the previous example the ecosystem provider may want to allow third party applications such as videogames to be developed and allowed to execute on the mobile device 200 . In certain embodiments however the ecosystem provider may not want third party managed applications to access any native resources such as native dynamically linked libraries, kernel functions, and/or drivers. Thus, in this example embodiment the manager 516 can be configured to prevent the managed application 412 from accessing such native resources and/or terminate the managed application 412 if the managed application 412 attempts to access such a resource. Managed application 412 can in an embodiment be stored in a digitally signed container such as container 300 of FIG. 3 . When the managed application 412 is launched, the container 300 can be checked to determine that it has not been tampered with, e.g., the digital signature 306 can be checked. If the digital signature 306 is valid, then the assemblies that effectuate the managed application 412 can be loaded into runtime space. Each assembly in the container 300 can be checked for a certificate 312 that indicates which managed libraries the application can call. The list of callable managed libraries can be stored in a table made accessible to the manager 516 and the manager 516 can be configured to prevent the managed application 412 from accessing native resources and/or managed libraries outside of the ones listed in the certificate 312 . In this example the managed application 412 can be terminated if the managed application 412 attempts to access such a resource.
[0040] Referring now to FIG. 7 , it depicts an alternative embodiment of the operational procedure of FIG. 6 including operations 706 , 708 , 710 , 712 , and 714 . Operation 706 illustrates the operational procedure of FIG. 6 , wherein the managed library comprises instructions generated by a trusted developer. For example, in one embodiment the managed library can be effectuated by intermediate language instructions and metadata. In this example the managed library 514 can have been generated by a trusted provider such as the ecosystem provider and/or a third party corporation that the ecosystem provider has a business relationship with. In this example the ecosystem provider can ensure that the managed library does not include malicious code or code that could be used in a malicious way by fully testing the code prior to releasing it to the public. In this example the ecosystem provider can ensure that the managed library can only be used to perform its indented function(s).
[0041] Continuing with the description of FIG. 7 , it additionally illustrates operation 708 that depicts verifying a digital signature associated with a container that includes the managed application; and loading the managed application. For example, in an embodiment of the present disclosure the title player 410 can be configured to load the managed application 412 in response to user input and determine that the managed application 412 is un-trusted. In an embodiment the ecosystem provider may associate a certificate 312 with the managed application 412 that identifies it as un-trusted and list one or more managed libraries that the un-trusted application can call. In this example embodiment the ecosystem provider may determine that code developed by a third party can access managed libraries that the ecosystem provider developed and the manager 516 can be configured to prevent the managed application 412 from accessing native system resources and/or terminate the managed application 412 if it attempts to access native resources or managed libraries for which the managed application has not been authorized to access.
[0042] Continuing with the description of FIG. 7 , it additionally illustrates operation 710 that shows the operational procedure of FIG. 6 , wherein the native functions of the operating system are accessed through instructions for a runtime host, further wherein the instructions for the runtime host are effectuated by native instructions. For example, in an embodiment of the present disclosure the title player 410 can include instructions configured to validate a digital signature of a runtime host 518 and launch the runtime host 518 . For example the instructions for the runtime host 518 can include an encrypted hash of the instructions that effectuate it. A corresponding public key can be stored in the secured store 418 of the mobile device 200 and made available when title player 410 attempts to load the runtime host 518 . The runtime host 518 in an example embodiment can be authenticated prior to execution because the instructions that effectuate the runtime host 518 can be stored in mass storage such as a hard drive or flash memory in at least one embodiment. In this example an attacker could attempt to replace the mass storage device with a malicious copy that could include code to attempt to access the secured store. In this embodiment the risk from such an attack can be mitigated by validating the runtime host 518 prior to execution.
[0043] In an example embodiment when the mobile device 200 is powered on the runtime host 518 may be loaded into main memory after a user uses the shell 408 to execute the videogame. For example, in an embodiment of the present disclosure the mobile device 200 may launch native instructions from the trusted layer of software when the mobile device 200 is powered on and only load the arbitration layer of FIG. 4 and FIG. 5 if a user of the mobile device 200 wants to execute a third party application. In this example when the title player 410 is launched it can in turn launch the runtime host 518 after it authenticates the runtime host's digital signature.
[0044] Continuing with the description of FIG. 7 , it additionally illustrates operation 712 that shows verifying a digital signature associated with the managed library; and loading the managed library. For example, in an embodiment of the present disclosure the title player 410 can include instructions configured to validate a digital signature of a container 300 that stores the managed library 514 and load the managed library 514 . For example, in an embodiment of the present disclosure the container 300 can include a digital signature encrypted with a private key. A corresponding public key can be stored in the secured store 418 of the mobile device 200 and made available when title player 410 attempts to load the managed application 412 .
[0045] Continuing with the description of FIG. 7 , it additionally illustrates operation 714 that shows wherein the managed application includes instructions verified by a remote device, further wherein the verified instructions are type safe. For example, in an embodiment of the present disclosure the managed application 412 can be verified by the ecosystem provider prior to distribution to the mobile device 200 . For example, in an embodiment verification can include examining the instructions and metadata associated with the managed application 412 to determine whether the code is type safe, e.g., that it accesses members of an object in well defined and allowed ways, it only accesses memory locations it is authorized to access, and/or that it does not access any private members of an object. During the verification process, the managed application's instructions can be examined in an attempt to confirm that the instructions can only access approved memory locations and only call methods through properly defined types.
[0046] Referring now to FIG. 8 , it depicts an operational flowchart for practicing aspects of the present disclosure including operations 800 , 802 , 804 , 806 , and 808 . Operation 800 beings the operational procedure and operation 802 illustrates receiving, by a manager, a request from a managed application to access a native system resource through a managed library. For example, a manager 516 can receive a request from a managed application 412 to access an operating system resource such as an application program interface for the operating system 404 via managed library 514 . In an embodiment of the present disclosure a managed application 412 such as a contact book application may attempt to access a resource of the operating system 404 such as a list of phone numbers stored in the secured store 418 via the functionality of a contact book managed library. In this example graphics, audio, and network support may be integrated with the operating system 404 and an application that has access to the operating system 404 could for example, potentially have the ability to access memory reserved to store device secrets such as DRM keys. In this example the managed application 412 may send a request to a manager 516 to access the operating system 404 via the managed library 514 . In this example both the managed application 412 and the managed library 514 can be considered managed because the instructions that effectuate them can be executed within virtual machine such as the common language runtime or java virtual machine. In this example the managed application 412 can be considered pure managed code because the managed application 412 is not allowed to access native resources and the managed library 514 can be considered non-pure managed code which indicates that the library is allowed to access some of the native resources.
[0047] Continuing with the description of FIG. 8 , operation 804 illustrates authorizing, by the manager, the request to access the native system resource through the managed library, wherein the manager includes information that identifies managed libraries that the managed application is authorized to access, further wherein the manager is effectuated by native instructions. For example, and referring to FIG. 5 , the manager 516 can be configured to allow the managed application 412 to access the managed library 514 in order to, for example, access a method of the graphics driver 422 for drawing a sprite at a certain location on a display. The manager 516 in this example embodiment can include a software process effectuated by native code. In this example the manager 516 can be configured to receive the request from the managed application 412 and determine whether the managed application 412 has permission to call the managed library 514 by accessing a table of information stored in memory such as RAM.
[0048] For example, in an embodiment of the present disclosure the manager 516 can store a table of information that includes a list of managed libraries that the managed application 412 can access. In the case of a pure managed assembly the list can include information that explicitly denies any attempt at calling native code or accessing reserved memory locations. If, for example, the pure managed assembly attempts to call a native dynamically linked library, access a memory location that stores a DRM key, or access a managed library that it is not permitted to access, the manager 516 can determine that a security violation occurred and terminate the managed application 412 . In an example embodiment the list of managed libraries that the managed application 412 can access can be stored in the secured store 418 . In this example the assembly 302 - 304 of FIG. 3 that contains the managed application 412 can be checked for a digital certificate 312 . In the instance where the assembly does not include a certificate 312 the manager 516 can be configured to determine that the assembly is un-trusted and load a predefined list of managed libraries that the managed application 412 can access into the table.
[0049] In another embodiment instead of having a two tier trust system, e.g., a system where managed applications are granted full permission or no permission based on the presence or absence of a certificate 312 , a multi-tiered system could be implemented by, for example, embedding different types of certificates in the assemblies or by including different sets of privileges in the certificates. In the first example the secured store 418 can be configured to include a table associating different types of certificates with different privileges, e.g., one certificate could be associated with a table entry that indicates that the managed application 412 is allowed to access a method of a network driver 420 and another certificate could be associated with a table entry that indicates that the managed application 412 is allowed to access an address book of a user stored in the secured store 418 . The operating system 404 or the title player 410 in this example could decrypt the certificate 312 and associate a number in the certificate to a set of privileges stored in the secured store 418 . In another embodiment the certificate itself could include information that identifies a set of operating system resources that the managed application 412 is allowed to access. In this example the operating system 404 or the title player 410 can be configured decrypt the certificate and compare a hash of the information in the certificate to an expected value. If the certificate is valid, the set of privileges can be retrieved from the certificate. Regardless as to how the operating system 404 or the title player 410 determines a managed application's privileges, the privileges can be transmitted to the manager 516 and the manager 516 can be configured to monitor instructions issued by the managed application 412 to determine whether it is attempting to access native code and/or load managed libraries that are not within the scope of its certificate.
[0050] Continuing with the description of FIG. 8 , it additionally illustrates operation 806 that shows authorizing, by the manager, the request to access the native system resource by the managed library, wherein information that identifies that the managed library is authorized to access the native system resource was obtained from a digital certificate associated with the managed library. For example, in an embodiment of the present disclosure the manager 516 can be configured to authorize the managed library's request to access a native system resource by, for example, allowing a managed library 514 to execute when the managed application 412 calls the managed library 514 . For example, in this embodiment the ecosystem provider may create a clear trust boundary between the managed application 412 and the operating system 404 by providing an arbitration layer that can include code that was developed by the ecosystem provider. In this example the arbitration layer can be used by un-trusted third party code to access native operating system resources in a well defined and trusted way. In one example embodiment the managed library 514 can be loaded as needed at runtime by, for example, the title player 410 . During the load process the manager 516 can be configured to request a level of trust for the newly loaded library by calling native code such as code of the operating system 404 or the title player 410 . The native code in this example embodiment can be configured to determine whether the assembly is trusted or not. In one embodiment the native code can be configured to check the authenticity of a certificate 312 stored in the managed library 514 . If the certificate is valid, e.g., it can be decrypted by a public key stored in the secured store and its hash matches an expected value, the operating system 404 or the title player 410 can be configured to grant the managed library 514 full rights to access unallocated memory, access operating system functions, or invoke native dynamically linked libraries.
[0051] For example and continuing with the description of FIG. 8 , operation 808 illustrates sending, by the managed library, a request to access the native system resource to a runtime host, wherein the runtime host is effectuated by native instructions. For example, in an embodiment of the present disclosure an operating system function can be requested by a managed application 412 and a managed library 514 can be used to implement the request by calling a runtime host 518 . The runtime host 518 in this example embodiment can be effectuated by native code and can be used so that only native code accesses the operating system 404 . In this example runtime host 518 can be a native dynamically linked library that includes application program interfaces for the functions that are made available to managed application 412 . In this embodiment the runtime host 518 can receive an instruction from, for example, a just in time complier that received an instruction from the managed library 514 and compiled it into native code that can be processed by the runtime host 518 .
[0052] Continuing with the description of FIG. 8 , operation 810 illustrates accessing, by the runtime host, the native system resource. For example, the runtime host 518 can be configured in this example to receive the instruction from the managed library 514 and invoke an operating system function operable to effect the request. For example, in an embodiment of the present disclosure mobile device 200 can be a cellular phone and managed application 412 may include a music player. In this example embodiment the music playing functionality could be integrated into the operating system 404 and in order to play a song an operating system method would need to be invoked. In this example the music player could access a managed library 514 that includes an application program interface for the music player. In this example the managed library 514 could be developed by the ecosystem provider whereas the managed application 412 could have been developed by a different entity, e.g., a different company or an individual. Thus, in this example when the managed library 514 is loaded its certificate can be validated and it can be authorized to access native resources. The managed library 514 for the music player can submit a request to the runtime host 518 and the runtime host 518 can be configured to invoke the music player driver of the operating system 404 and the song can be played.
[0053] Referring now to FIG. 9 , it illustrates an alternative embodiment of the operational procedure 800 of FIG. 8 including the additional optional operations 912 , 914 , 916 , and 918 . Referring to operation 912 , it illustrates the operational procedure 800 of FIG. 8 , wherein the native system resource is accessed from a platform invoke. For example, in an embodiment of the present disclosure a platform invoke can be used by managed assemblies to access a native system resource of the operating system 404 , e.g., a native dynamically linked library. For example, in this embodiment when the platform invoke is used to call a function of the operating system 404 the interface for the function can be located and loaded into memory. The address of the function can be obtained and an argument for the function can be pushed to the interface. In a specific example a third party application could be a videogame that requires functionality of a graphics driver of the operating system in order to draw sprites. In this example the videogame can pass a request to draw the sprite to a managed graphics library that could for example, contain low-level application programming interface methods for drawing sprites. In this example the managed graphics library can receive the request and perform a platform invoke on, for example, runtime host 518 . The interface of the runtime host 518 can be loaded into memory and the argument, e.g., the request to draw the sprite, can be pushed into a memory area reserved for the runtime host 518 .
[0054] Referring again to FIG. 9 , it additionally depicts operation 914 that illustrates executing a title player, wherein the title player is effectuated by native instructions. For example, in an embodiment of the present disclosure the mobile device 200 can include instructions for a title player 410 . For example, in one embodiment the instructions that effectuate the title player 410 can be native to the mobile device 200 , e.g., they can be instructions configured to execute on a processor of the hardware 402 of FIG. 4 . In an embodiment of the present disclosure the title player can 410 can be stored in firmware of the mobile device 200 and can include a digital signature. In this example embodiment the title player 410 can be used to execute a managed application 412 and can be invoked by the shell 408 . For example, a user can interact with the shell 408 and select an option to launch a program operable to pull stock information from the internet. In response to the request the shell 408 , e.g., native instructions, can launch the title player 410 . In at least one embodiment the shell 408 and/or the operating system 404 can be configured to check the digital signature of the title player 410 prior to execution to determine whether the title player 410 is authentic.
[0055] Continuing with the description of FIG. 9 it additionally depicts operation 916 that depicts determining, by the manager, that the managed application is permitted to access a premium native system resource, wherein information that identifies that the managed application is permitted to access the premium native system resource was obtained from a premium certificate associated with the managed application. For example, in an embodiment of the present disclosure a managed application 412 can be configured to have a premium level of access to the native functionality of the mobile device 200 via a premium managed library. For example, in an embodiment the managed application 412 may receive access to additional resources of the mobile device 200 , e.g., the developer of the managed application 412 may be considered a trusted developer or other business reasons may contribute to the third party developer being granted to a higher level of resources. In this example the managed application 412 may be developed using the development studio that relies on a plurality of class libraries to implement the low level application program interfaces and these libraries may, for example, be provided by the ecosystem provider. In this example the ecosystem provider may develop a class library that has access to premium functionality of the operating system 404 such as a library that makes a DRM protected music file available to a third party application. In this embodiment the managed application 412 can be associated with a premium certificate that permits it to have access to a DRM protected audio stream. When the managed application is loaded the manager 516 can be provided with information that can be used to authorize a request to access the premium managed library.
[0056] Continuing with the description of FIG. 9 , it additionally depicts operation 918 that illustrates the procedure 800 , wherein the managed application is stored in a container that includes a digital signature. For example, in an embodiment of the present disclosure the managed application can be stored in a container such as the container 300 of FIG. 3 . For example, in an embodiment of the present disclosure the ecosystem provider can include techniques for storing managed applications in containers and digitally signing them. In this example the ecosystem provider can be configured to generate a hash of the information in the container and encrypt the hash using a private encryption key. A corresponding public key can be stored in the secured store 418 of the mobile device 200 . When the mobile device 200 opens the container 300 , the public key can be used to decrypt the hash. A hash of the container 300 can be calculated and compared to the expected hash. If the hashes match then the mobile device 200 can be configured to allow the managed application from the container 300 to execute.
[0057] Referring now to FIG. 10 , it depicts an alternative embodiment of the operational procedure 800 of FIG. 9 including the additional operations 1020 , 1022 , and 1024 . Referring now to operation 1020 , it illustrates validating, by the title player, a digital signature associated with the runtime host; and executing the runtime host. For example, in an embodiment of the present disclosure the title player 410 can include instructions configured to validate a digital signature of the runtime host 518 and launch the runtime host 518 . For example, in an embodiment of the present disclosure the instructions that effectuate the runtime host 518 can be stored in mass storage along with a hash of the runtime host 518 encrypted with a private key. A corresponding public key can be stored in the secured store 418 of the mobile device 200 and made available when title player 410 attempts to load the runtime host 518 . If the runtime host 518 is authentic then it can be loaded by the title player 410 .
[0058] In an example embodiment when the mobile device 200 is powered on the runtime host 518 may be loaded into memory after a user uses the shell 408 to execute the managed application 412 . For example, in an embodiment of the present disclosure the mobile device 200 may launch native instructions from the trusted layer of software when the mobile device 200 is powered on and only load the arbitration layer of FIG. 4 and FIG. 5 if a user of the mobile device 200 wants to execute a managed application 412 . In this example when the title player 410 is launched it can in turn launch the runtime host 518 after it authenticates the runtime host's digital signature.
[0059] Continuing with the description of FIG. 10 , operation 1022 illustrates validating, by the title player, a digital signature associated with the manager; and executing the manager. For example, in an embodiment of the present disclosure the title player 410 can include instructions configured to validate a digital signature of the manager 516 and launch the manager 516 . For example, the instructions that effectuate the manager 516 can be stored in mass storage, e.g., flash or a hard disk, along with a hash of the instructions encrypted with a private key. A corresponding public key can be stored in the secured store 418 of the mobile device 200 and made available when title player 410 attempts to load the manager 516 . If the manager 516 is authentic then it can be loaded by the title player 410 .
[0060] In an example embodiment when the mobile device 200 is powered on the manager 516 may be loaded into memory after a user uses the shell 408 to execute the managed application 412 . For example, in an embodiment of the present disclosure the mobile device 200 may launch native instructions from the trusted layer of software when the mobile device 200 is powered on and only load the arbitration layer of FIG. 4 and FIG. 5 if a user of the mobile device 200 wants to execute a managed application 412 . In this example when the title player 410 is launched it can in turn launch the manager 516 after it authenticates the manager's digital signature.
[0061] Continuing with the description of FIG. 10 it additionally depicts operation 1024 that shows loading, by the title player, the managed application; determining, by the title player, that the managed application is un-trusted; and denying, by the manager, the managed application access to native system resources. For example, in an embodiment of the present disclosure title player 410 can be configured to load the managed application 412 in response to user input and determine that the managed application 412 is un-trusted. For example, the managed application 412 can be considered un-trusted if it lacks a digital certificate 312 . In this embodiment the ecosystem provider may not associate a digital certificate with the managed application 412 if it was developed by a third party such as a remote company or individual. In another embodiment the ecosystem provider may associate a certificate with the managed application 412 that identifies it as un-trusted. In either example embodiment the ecosystem provider may determine that code developed by a third party can be configured to access managed libraries that the ecosystem provider developed and the manager 516 can be configured to prevent the managed application 412 from accessing native resources such as native dynamically linked libraries. In this example, the title player 410 can open the managed application and determine that it is to be considered un-trusted. The title player 410 in this example can make this information available to the manager 516 that can in turn monitor instructions that the third party application issues. In the event that the application attempts to access native instructions of the system, e.g., an operating system method, a security violation can be detected and the manager 516 can terminate the managed application 412 .
[0062] Referring now to FIG. 11 , it depicts an alternative embodiment of the operational procedure 800 of FIG. 9 including the additional operations 1126 , and 1128 . Referring now to operation 1126 , it illustrates transmitting the container to a remote mobile device. For example, and referring to FIG. 2 , in an embodiment of the present disclosure a mobile device 200 can include a wireless and/or wired network connection to a remote mobile device 202 . In this example the mobile device 200 can share the managed application 412 with the remote mobile device 202 . For example, the remote mobile device 202 could use the shared application for a limited amount of time or a limited amount of executes before the managed application 412 locks. In this example the remote mobile device 202 could access the electronic market place 222 and purchase a full license to the managed application 412 .
[0063] Continuing with the description of FIG. 11 , it additionally illustrates operation 1128 that illustrates an alternative embodiment of the operational procedure of FIG. 9 , wherein the managed application includes instructions verified by a service provider, further wherein the verified instructions are type safe instructions. For example, in an embodiment of the present disclosure the managed application 412 can be previously verified by the ecosystem provider prior to distributing the managed application 412 to the mobile device 200 . For example, in an embodiment verification can include examining the instructions and metadata associated with the managed application 412 to determine whether the code is type safe, e.g., that it accesses members of an object in well defined and allowed ways, it only accesses memory locations it is authorized to access, and/or that it does not access any private members of an object. During the verification process, the managed application's instructions can be examined in an attempt to confirm that the instructions can only access approved memory locations and/or call methods only through properly defined types.
[0064] Referring now to FIG. 12 , it illustrates an example operational procedure related to publishing videogames configured to execute on a mobile device including operations 1200 , 1202 , 1204 , 1206 , and 1208 . Operation 1200 begins the operational procedure and operation 1202 illustrates receiving a package from a networked computer system. For example, and referring to FIG. 2 , a network adaptor of a validation system 212 can receive a package from a networked computer system that can include, but is not limited to, a community feedback server 206 , a peer reviewer, and/or a developer 204 . In an example embodiment of the present disclosure the package can include one or more assemblies, e.g., executables and dynamically linked libraries. In one example the libraries could be made by the developer 204 and/or by the ecosystem provider.
[0065] Continuing with the description of FIG. 12 , operation 1204 illustrates identifying an executable in the package. For example, in an embodiment of the present disclosure the package can be received by the validation system 212 and sent to a file parser 216 . For example, the file parser 216 can be configured to scan the package for assemblies that contain executables. For example, in one embodiment the parser 216 can be configured to check the entire package for .exe files, and/or files that include executables stored in, for example, images and generate a list of all .exe and .dll files in the package.
[0066] Continuing with the description of FIG. 12 , operation 1206 illustrates verifying managed metadata associated with the executable, wherein the managed metadata describes the structure of executable, further wherein verifying the managed metadata includes inspecting the managed metadata at runtime to determine that the executable includes type safe code. For example, in an embodiment of the present disclosure after the file parser 216 identifies executables in the package a list of executables and the package can be transmitted to the file verification system 218 . The verification system 218 in this example embodiment can be configured to determine whether the executables are valid by checking, for example, certain values in the header and the metadata. For example, in an embodiment of the present disclosure the verification system 218 can be configured to validate the metadata by exercising it. As was described above, in one embodiment a package can be submitted that can include one or more assemblies each of which can include intermediate language instructions and metadata. In this example the verification system 218 can be configured to inspect each assembly's metadata using a process called reflection, and inspect each assembly's managed instructions. The reflection process includes an application programming interface that can walk through the managed metadata and monitor the runtime characteristics of the metadata to identify malicious instructions that could, for example, attempt to access native code or access the secured content on the mobile device 200 . In addition, the reflection API can be configured to determine whether the instructions are type safe, e.g., that it accesses members of an object in well defined and allowed ways, it only accesses memory locations it is authorized to access, and/or that it does not access any private members of an object.
[0067] In another example embodiment the verification system 218 can be configured to identify managed libraries that the executables attempt to link at runtime and compare them to a list of approved managed libraries. The verification system 218 can be configured in this example to reject any executable that attempts to link a restricted library or a library that the application should not have access to, e.g., a videogame should not have access to a managed library that can access device keys stored in a secured store 418 .
[0068] Continuing with the description of FIG. 12 , operation 1208 illustrates storing the verified executable in a digitally signed container. For example, once the executable is verified by the verification system 218 it can be sent to a signing system 220 configured to repackage the assemblies into a container such as container 300 of FIG. 3 and digitally sign the container 300 . The signing system 220 in this example can be configured to generate a hash of the instructions in the container 300 and encrypt the hash with a private key. In this example a mobile device 200 can be configured to include a public key usable to decrypt the container 300 and compare the hash of the information in the container 300 to the expected result. Once the container 300 is signed it can in one embodiment transmit the container 300 to an electronic market place 222 where it can be purchased by a user of the mobile device 200 and downloaded. In another embodiment the signing system 220 can be configured to include information that identifies what managed libraries can be accessed by the container 300 in digital certificates for each assembly stored in the container 300 .
[0069] Referring now to FIG. 13 , it illustrates an alternative embodiment of the operational procedures of FIG. 12 including the additional operations 1310 , 1312 , and 1314 . Referring now to operation 1310 , it illustrates transmitting the digitally signed container to a mobile device. For example, in an embodiment of the present disclosure the container 300 can be transmitted to a mobile device 200 after, for example, it is purchased. As stated above, in an embodiment of the present disclosure the ecosystem provider can maintain an electronic market place 222 that is configured to allow users to purchase games that are submitted by third party developers such as companies and/or individuals that obtain the software developers kit.
[0070] Continuing with the description of FIG. 13 , it additionally illustrates operation 1310 that depicts determining that the executable in the file includes managed dependencies. For example, in at least one example embodiment the verification system 218 can be additionally configured to determine what dependencies are required by the executable and either reject the package or forward the package to the signing system 220 . For example, the verification system 218 in this embodiment can be configured to identify the set of assemblies in the applications' runtime profile. The verification system 218 in this example can identify each assembly and determine whether the assemblies are developed by the ecosystem provider or the developer 204 . In the instance where an identified assembly is developed by the ecosystem provider the verification system 218 can be configured to determine whether the assembly is on a white list for the type of managed application, e.g., the verification system 218 can check the white list to determine whether an assembly that can access the secured store 418 is allowed to be called by a videogame. If the assembly is not on the white list, the process can end and a message can be sent to the developer 204 stating that the assembly is not accessible to, for example, the type of managed application and/or the developer 204 , e.g., the developer 204 may not have trusted status. The verification system 218 in this example can additionally check to determine that native libraries are not referenced by the metadata. In a specific example, if the managed application includes a reference to a native library then the managed application can access the library and take control of the mobile device 200 . If the verification system 218 determines that the assembly references a native library the verification process can end and a message can be sent to the submitter stating that the validation process failed because a native library was referenced.
[0071] Continuing with the description of FIG. 13 , it additionally illustrates operation 1312 that depicts validating header fields of the executable. For example, in an embodiment of the present disclosure the header fields of the executable can be checked by the verification system 218 to determine whether they include expected header values. For example, each executable can include one or more headers that can include information such as how the runtime environment is to map the file into memory or how configure the loader and linker. The file in this example can additionally include data directory header values that contain pointers to data. For example, in an embodiment the verification system 218 can be configured to check the header values and fail any package that includes values that are associated with files that include native instructions.
[0072] The foregoing detailed description has set forth various embodiments of the systems and/or processes via examples and/or operational diagrams. Insofar as such block diagrams, and/or examples contain one or more functions and/or operations, it will be understood by those within the art that each function and/or operation within such block diagrams, or examples can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof.
[0073] While particular aspects of the present subject matter described herein have been shown and described, it will be apparent to those skilled in the art that, based upon the teachings herein, changes and modifications may be made without departing from the subject matter described herein and its broader aspects and, therefore, the appended claims are to encompass within their scope all such changes and modifications as are within the true spirit and scope of the subject matter described herein.
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Disclosed is a code verification service that detects malformed data in an automated process and rejects submission and distribution if any malicious code is found. Once the submission is verified it may be packaged in container. The container may then be deployed to a mobile device, and the public key may be used to verify that the container authentic. The device can load trusted managed libraries needed to execute the application and a manager can ensure that only trusted libraries access native resources of the device.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a voltage driven type MOS controlled thyristor and method for fabricating the same which has a four layer pnpn structure turned on and which off by two MOS gates, and is used as a power switching device.
2. Description of the Prior Art
Gate-turnoff thyristors (GTOS) that can be turned off by a gate signal are extensively employed. A GTO, however, has a disadvantage in that it requires a relatively large gate-driving power to turn off because it is a current driven device. To overcome this disadvantage, a voltage driven MOS gate transistor is proposed. An MOS gate transistor, like an insulated gate bipolar transistor (IGBT), has a structure to drive a wide base transistor by an MOS gate. An MOS gate thyristor, however, differs from an IGBT in that, although an IGBT does not latch the inner parasitic thyristor does, an MOS gate thyristor latch it so that not only the gate voltage but also the anode voltage must be reversed to turn-off the device.
MOS controlled thyristors (MCT) have been proposed which use voltage driven MOS gates to turn on and off the device. The MCT has a structure such that MOSFETS incorporated into the pnpn thyristor turn on and off the thyristor. More specifically, as shown in FIG. 1, on a low resistivity n+ layer (a first layer) 1, a low resistivity p+ layer (a second layer) 2 is formed, which is followed by a high resistivity p- layer (a third layer) 3. In the surface of the p- layer 3, an n layer (a fourth layer) 4 is selectively formed, and then, in the surface of the n layer 4, a p layer (a fifth layer) 5 is selectively formed. Subsequently, in the surface of the p layer 5, a p+ layer (a sixth layer) 6 and n+ layers (seventh layers) 7 are selectively formed. In addition, gate electrodes 9 are formed, via gate insulating films 8, on surface regions 15 of the n layer 4 between the p layer 5 and the p- layer 3, and on surface regions 17 of the p layer 5 between the n+ layer 7 and the n layer 4 so that the surface regions 15 and 17 form channel regions. Further, an anode electrode 10 making contact with the surface of both the p+ layer and the n+ layers 7, and a cathode electrode making contact with the n+ layer 1 are provided. The anode electrode 10 is insulated from the gate electrodes 9 with insulating layers 12.
This MCT is activated by applying a voltage to the gate electrodes 9 and the cathode electrode 11 with the anode electrode being grounded. To turn on the MCT,, a negative voltage is applied to the gate electrodes 9 so that p channels are formed in the surface regions 15 of the n layer 4 between the p layer 5 and the p- layer 3. Thus, holes flow through the p channels toward the cathode electrode 11 when a negative voltage is applied to the cathode electrode 11, thereby turning on the n+/p+ junction 19 between the n+ layer 1 and the p+ layer 2, and resulting in injection of electrons from the n+ layer 1 into the p+ layer 2. The electrons, passing through the p- layer 3 and the n layer 4, turn on the p/n junction 21 between the n layer 4 and the p layer 5 and the p/n junction 23 between the n layer 4 and the p+ layer 6. Thus, hole injection from the p layer 5 and p+ layer 6 to the n layer 4 takes place, thereby turning on the npnp thyristor. The on resistance of the thyristor is low owing to conductivity modulation taking place in the p+ layer 2, p- layer 3 and the n layer 4.
To turn off the MCT, a positive voltage is applied to the gate electrodes 9 so that n channels are formed in the surface regions 17 of p layer 5 between the n+ layer 7 and the n layer 4. Thus, the n+ layer 7 and the n layer 4 become equipotential, which in turn makes the p+ layer 6 and the n layer 4 equipotential because the p+ layer 6 is connected to the n+ layer 7 via the anode electrode 10. As a result, although electrons injected into the p+ layer 2 from the n+ layer 1 reach the p/n junction 21 between the n layer 4 and the p layer 5, and the junction 23 between the n layer 4 and the p+ layer 6, they flow into the anode electrode 10 through the n channels in the surface regions 17 so that hole injection from the p layer 5 into the n layer 4 does not occur, thus completing the turn off operation. Similar operations take place in a complementary MCT which has opposite conductivity type layers to those of the above MCT, has an MOS structure at the side of a cathode electrode when voltages of the opposite polarity are applied.
It is preferable that the MCT have a high turn-off speed as a switching device. To improve the turn-off speed, it is necessary to quickly remove excess carriers stored in the p+ layer 2, p- layer 3 and the n layer 4 in the conducting state. One method of improve the turn-off speed is to employ a cathode short structure in which the p+ layer 2 is short-circuited to the n+ layer 1 by the cathode electrode 11. This structure has an advantage that excess carriers stored in the p+ layer during the conducting state are easily removed. The structure, however, has a disadvantage that conductivity modulation suddenly takes place after a certain time has elapsed at the initial stage of turning-on owing to the reduction in the electron injection from the n+ layer 1 to the p+ layer 2, and hence, a negative resistance phenomenon is liable to occur during transition from the off to the on state, resulting in an increase in turn-on loss. On the other hand, in a normal cathode structure without a cathode short hole that short-circuits the p+ layer 2 to the cathode electrode 11, the negative resistance phenomenon is eliminated. This structure, however, reduces the carrier removal effect at the turn-off operation, and increases the turn-off loss.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an MOS controlled thyristor and method for fabricating the same that can prevent the negative resistance phenomenon at the turn-on operation and reduce the turn-off loss by improving the trade off relationship between the turn-on loss and the turn-off operation.
In the first aspect of the present invention, an MOS controlled thyristor comprises:
a first layer of a heavily doped first conductivity type;
a second layer of a heavily doped second conductivity type, which is disposed on the first layer;
a third layer of a lightly doped second conductivity type, which is disposed on the second layer;
a fourth layer of a first conductivity type, which is selectively formed in a surface region of the third layer;
a fifth layer of a second conductivity type, which is selectively formed in a surface region of the fourth layer;
a sixth layer of a second conductivity type, which is selectively formed so as to protrude into the fourth layer through the fifth layer;
a seventh layer of a first conductivity type, which is selectively formed in the surface of the fifth layer so as to make contact with the sixth layer;
a first channel region formed in a surface of the fourth layer between the third and fifth layers;
a second channel region formed in a surface of the fifth layer between the fourth and seventh layers;
an insulating film formed on a surface of the first and second channels;
a gate electrode formed on the insulating film;
a first major electrode making contact with the first layer;
a second major electrode making contact with the sixth and seventh layers; and
an eighth region of highly doped second conductivity type, which is selectively formed in the first layer so as to make contact with the first major electrode, but does not protrude into the second layer.
The contact area of the eighth region with the first major electrode may be at least 25% of the total contact area of the first major electrode with the first layer.
The depth of the eighth region may be equal to or less than 80% of the depth of the first layer.
In the second aspect of the present invention, a method for fabricating an MOS controlled thyristor the method includes fabrication of a multi-layer structure of alternate p-type and n-type layers, a first major electrode contacting a first outer layer of the multi-layer structure, a second major electrode contacting a second outer layer of the multi-layer structure at the opposite side of the first outer layer, and an MOS structure disposed in a surface of the second outer layer for controlling the turn-on and turn-off currents of the multi-layer structure. The method also comprises the step of forming in the first outer layer a highly doped region of the opposite conductivity type to that of the first outer layer in such a fashion that the highly doped region contacts the first major electrode, but does not protrude into an inner layer adjacent to the first layer in the multi-layer structure.
The contact area of the highly doped region with the first major electrode may be made at least 25% of the total contact area of the first major electrode with the first layer.
The depth of the highly doped region may be made equal to or less than 80% of the depth of the first layer.
According to the present invention, the eighth region is not connected to the second region. Thus, the first region remains between the eighth and second regions so that a complete cathode short or anode short is not formed. To turn on the device, a voltage of about 0.8 V corresponding to the diffusion potential of the junction between the first region of the first conductivity type and the second region of the second conductivity type is applied to the first major electrode. In this condition, the minority carrier injection from the first region to the second and third regions surely takes place so that no negative resistance phenomenon occurs. On the other hand, when the device is turned off, the majority carriers, which are stored in the second and third regions, and are removed by the change dV/dt in the voltage of the first major electrode, chiefly flow toward the first major electrode through the eighth region so that the reinjection of the minority carriers from the first region is restricted. Thus, the turn-off current is reduced, resulting in the reduction in the turn-off loss.
The above and other objects, effects, features and advantages of the present invention will become more apparent from the following description of the embodiments thereof taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional view showing the structure of a conventional MCT;
FIG. 2 is a cross sectional view showing an embodiment of an MCT according to the present invention;
FIG. 3 is a graph comparatively illustrating curves of trade-off characteristics between the ON-voltage and the turn-off loss of the MCT of the invention and the conventional MCT;
FIG. 4 is a graph comparatively illustrating curves of trade-off characteristics between the ON-voltage and the turn-off loss of the MCT of the invention and a conventional cathode short type MCT;
FIG. 5 is a graph illustrating the relationship between the contact area ratio of the cathode electrode, and the ON-voltage and turning-off loss; and
FIG. 6 is a graph illustrating the relationship between the voltage and current of an MCT of the embodiment when the thickness ratio of the eighth region (a p+ region 13) to that of the n+ layer 1 is varied.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention will now be described with reference to the accompanying drawings.
FIG. 2 is a cross sectional view showing an embodiment of an MCT according to the present invention, in which the same parts as those of FIG. 1 are designated by the same reference numerals: reference numerals 1 to 7 designate the to seventh regions, respectively. The MCT of the embodiment of the invention shown in FIG. 2 differs from that of FIG. 1 in that a shallow p+ region (the eighth region) 13, thinner than the n+ layer 1, is embedded in a part of the n+ layer 1. This device is fabricated by the following steps.
First, a p+ layer 2 of 20 μm thickness, and a p- layer 3 of 180 μm thickness are sequentially deposited on the surface of an n+ substrate (n+ layer) 1 by using an epitaxial-growth process. Here, the resistivities of the n+ layer 1, the p+ layer 2 and the p- layer 3 are 0.01 Ω-cm, 0.1 Ω-cm and 200 Ω-cm, respectively.
Second, a polysilicon layer of 1.0 μm thickness is formed on the surface of the p- layer 3 via a gate oxide film 8. The polysilicon layer is patterned to form gate electrodes 9.
Third, an n layer 4 is formed by phosphorous ion implantation using the gate electrodes 8 as masks, and by subsequent annealing. Here, a typical ion energy of the ion implantation is 100 keV, and a typical ion dose is 8.0×10 13 ions cm 2 . The annealing is typically performed for 5 hours at 1,150° C.
Fourth, a p layer 5, a p+ layer 6 and n+ layers 7 are sequentially formed by an ion implantation process using as masks the gate electrodes 8 and resist films as needed, and by a subsequent annealing process. Here, a typical ion energy of the boron ion implantation for forming the p layer 5 is 150 keV, and a typical ion dose is 1.0×10 14 ions/cm 2 . The annealing for forming the p layer 5 is typically conducted for 3 hours at 1,100° C. A typical ion energy of the boron ion implantation for forming the p+ layer 6 is 150 keV, and a typical ion dose is 2.0 ×10 14 ions/cm 2 . The annealing for forming the p+ layer 6 is carried out for 4 hours at 1,100° C. A typical ion energy of the arsenic ion implantation for forming the n+ layer 7 is 120 keV, and a typical ion dose is 5.0×10 15 ions/cm 2 . The annealing for forming the n+ layer 7 is typically performed for 1 hour at 1,000° C.
Fifth, a p+ region 13 is formed in the n+ layer 1 by means of boron ion implantation and by subsequent annealing. The ion implantation is conducted from the surface of the n+layer using an oxide mask formed on that surface. Here, a typical ion energy of the boron ion implantation is 120 keV, and a typical ion dose is 2.5×10 15 ions/cm 2 . The annealing is typically performed for 3 hours at 1,100° C.
Finally, insulating films 12 are formed by using PSG (phosphosilicate glass) of 1.2 μm thickness and LTO of 1.5 μm thickness, and an anode electrode 10 and a cathode electrode 11 are made of Al - 1% (at%) Si evaporation film.
Although the resistivity of the n+ layer 1, and the resistivities and thicknesses of the p+ layer 2 and the p- layer 3 are equal to those of the conventional example described before, the thickness of the n+ layer is specified at 5 μm and the p+ region 13 is embedded 3 μm thick in the n+ layer 1. The p+ region 13 has a surface impurity concentration of 2.0×10 19 /cm 3 , and a surface area equal to 30% of the entire area of the cathode electrode 11.
FIG. 3 is a graph comparatively illustrating trade-off curves between the ON-voltage Von and the turn-off loss Eoff of the embodiment of the MCT of the present invention and the conventional MCT as shown in FIG. 1. Reference numeral 31 denotes the curve of the MCT of the present invention, and reference numeral 32 designates that of the conventional MCT. From FIG. 3, it is clear that the MCT of the present invention has superior trade-off characteristics to those of the conventional MCT: for example, at Von = 2.5 V, Eoff is reduced by about 40%.
FIG. 4 is a graph illustrating by comparison the trade-off curves between the ON-voltage Von and turn-off loss Eoff of the embodiment of the MCT of the present invention and a conventional MCT having cathode short holes in the entire area of the n+ layer 1. Reference numeral 41 denotes the curve of the MCT of the present invention, and reference numeral 42 designates that of the conventional MCT. From FIG. 4, it is clear that the MCT of the present invention has superior trade-off characteristics to those of the cathode short type MCT: for example, at Eoff = 3, Von is reduced by about 2.3 V.
When the contact area ratio of the p+ region 13 to the cathode electrode 11 is reduced in the structure of FIG. 2, Eoff increases although Von decreases as shown in FIG. 5. In FIG. 5, the abscissa represents the contact area ratio of the p+ region 13 to the cathode electrode 11, and the ordinate represents the ON-voltage Von and the turn-off loss Eoff. As is clear from FIG. 5, the contact area ratio is preferably 25% or more.
Furthermore, although the turn-off loss Eoff declines as the thickness ratio of the p+ region 13 to the n+ layer 1 increases, a negative resistance phenomenon is liable to occur when the ratio exceeds 80% as shown in FIG. 6. In FIG. 6, the abscissa represents the ON-voltage between the anode and cathode, the ordinate represents the current flowing through the device, and the curves [11]-[51] are plotted for the ratios 0.5, 0.65, 0.15, 0.8 and 0.85. It is seen from FIG. 6 that the ratio (the depth of the p+ region 13) / (the depth of the n+ layer 1) is preferably less than 80%.
Although the above embodiment is described with regard to an MCT in which an MOS structure is disposed at the anode electrode side, the present invention can also be applied to an MCT in which the MOS structure is disposed at a cathode electrode side by forming an n+ region in a p layer making contact with the anode electrode.
The present invention has been described in detail with respect one embodiment of the invention, and it will now be apparent from the foregoing to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and it is the intention, therefore, in the appended claims to cover all such changes and modifications as fall within the true spirit of the invention.
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An MCT (MOS controlled thyristor) including a first outer layer of a first conductivity type whose surface contacts a first major electrode, and a second outer layer at which an MOS structure is disposed, and whose surface contacts a second major electrode. The MCT is provided with a second conductivity type region formed in the first outer layer in such a manner that it contacts the first major electrode, but does not contact an inner layer adjacent to the first layer. The MCT has a low on-resistance, a small turn-off loss, and can prevent a negative resistance phenomenon from occurring.
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[0001] The present application is a continuation-in-part of U.S. patent application Ser. No. 12/905,309, filed Oct. 15, 2010, and entitled “A Rapidly Self-Drying Rectifying Flame Rod”. U.S. patent application Ser. No. 12/905,309, filed Oct. 15, 2010, is hereby incorporated by reference.
BACKGROUND
[0002] The present disclosure pertains to flame sensing and ignition and particularly to precipitation resistant mechanisms for sensing and igniting pilots.
SUMMARY
[0003] The disclosure reveals a system having a flame rod assembly for operation in a high temperature pilot burner. The assembly is designed for operation in temperatures from about −40 to 1100 degrees C. The system may operate in inclement weather involving high speed winds and significant amounts of moisture and rain. The system incorporates an electrical apparatus which may provide flame sensing and ignition via the flame rod assembly incorporating a quick drying insulator around the rod.
BRIEF DESCRIPTION OF THE DRAWING
[0004] FIG. 1 is a diagram of a pilot for an industrial process flare assembly;
[0005] FIG. 2 is a diagram of an illustrative example of a flame rod assembly for a detection and ignition mechanism;
[0006] FIGS. 3 a and 3 b are diagrams of configurations of a flame rod assembly for a pilot burner; and
[0007] FIG. 4 is a diagram of still another configuration of a flame rod assembly.
DESCRIPTION
[0008] An industrial process flare may need a computerized electronic management system to continuously monitor the existence of its pilot flame. This may be to ensure that the flare will ignite when the need arises. As electronic management technology advances, a closed loop feedback time cycle required may decrease. However, related art flame monitoring technology is currently not necessarily providing adequate response times.
[0009] Ionization flame rod technology may indicate an existence of a flame virtually instantaneously. Because of extreme environmental conditions, a product is needed for use in flare pilot applications. The product may utilize several characteristics to overcome various challenges. A location of the flame rod may ensure that it will work continuously in high wind speed environments. A hermetic seal and a particular profile of a rod insulator may keep heavy rain and moisture from causing a failure of the flame rod. A signal cable connected to the rod at the insulator should be of the type that can withstand high temperatures. The materials and manufacturing processes may allow the resultant flame rod product to withstand very high temperatures during an operational life. Also, such product may be rapidly self-drying. These considerations may differentiate the present flame rod product from other flame rod technology in terms of reliability and service life, thus giving a holder of the present flare rod product a competitive advantage in the flare and flare pilot market.
[0010] The present product may contain a limited number of parts. The flame rod and its threaded connections may be either cast or machined from a steel or stainless steel alloy (selected as required for service). The insulator may be made of any suitable insulating material, such as ceramic. The insulator material may be cast with a specific geometry and attached to a flame rod at the end connections via a high temperature coupling with brazing or welding. “Brazing” or “welding” may be referred to as “brazing” herein. “High temperature” brazing may withstand temperatures at least up to 1100 degrees Celsius (C.) (2012 degrees F.). The brazing process may satisfy specifications for integrity and temperature requirements. Results of high temperature brazing may withstand temperatures equal to or greater than about 815 degrees C. (1500 degrees F.). The high temperature brazing process may involve a use of alloys incorporating materials such as chromium, nickel, and other like materials. Ordinary or low temperature brazing may involve a use of materials such as copper, silver, and the like.
[0011] A signal cable attached to the flame rod may have a high temperature rating sufficient for the operating conditions. An example flame rod product may meet geometrical requirements as revealed in FIG. 2 . The metallic materials may be machined or cast from suitable steel or stainless steel alloys. The alloys may incorporate, but are not necessarily limited to, ASTM 304, ASTM 310, ASTM 316, Inconel™, Kanthol (or Kanthal), hastaloy (or Hastelloy™), and so forth.
[0012] An ignition/flame rod for a flare may provide flame ignition through sparking and detection through ionization detection in a pilot for a flare system. The product may be exposed to extreme temperatures (i.e., −40 to 1100 degrees C.). The product may be mounted several hundred of feet above the ground in the air, or mounted close to the ground, or somewhere in between. The product needs to withstand the extreme temperatures without having its performance affected. The product should be robust enough to have at least five years of life without issues, which may be the typical lifecycle of a refinery between service times. Detection should be reliable at a six-sigma level and be without false positives.
[0013] In sum, certain aspects of the present product may incorporate self drying capabilities, a temperature resistance up to 1100 Celsius degrees, and a combination of detection and ignition capabilities. Particularly, the ceramic insulator may have self-drying capabilities. Likewise, the flame rod may have self-drying capabilities.
[0014] The flame rod may be made of a high temperature, high performance (HP) alloy, to withstand the severe temperatures produced both by the pilot flame and by the flare flame. The rod may be connected to a longer rod or tubing made of a high temperature resistant alloy. An electrical signal may be transmitted through a naked rod/tubing to a wire several feet below and then to an electric box. The electric box may provide a carrier voltage for ionized gas detection from the pilot flame through a flame relay and another voltage for sparking through a high voltage transformer. A switch may allow an electrical passage selectively between the two devices. The switch box may be placed at a ground level. Two ceramic insulators may provide protection against short circuiting and may be placed in the upper part of the unit, where the naked rod is the distance between the two ceramic assemblies ( FIG. 4 ). The distance may, for example, be several feet. The tip of the rod may be inserted in the pilot tip above the gas spud.
[0015] A ceramic insulator assembly may be provided. A flame rod may be purchased and inserted in the ceramic insulator. High temperature alloy tubing or a rod may be attached to the bottom end of the insulator assembly with a coupling. The second ceramic insulator assembly may be inserted in the high temperature alloy tubing or rod. A wire may be attached to the bottom part of the assembly and run all the way to the switch box. The switch box may be placed at grade, or where the customer specifies, and it may be connected to the electric power source.
[0016] FIG. 1 is a diagram of a pilot 11 for an industrial process flare assembly 12 . Flare 12 may have a tube or stack 13 . On top of tube 13 may be a nozzle 16 upon which a flare main flame 17 of flare 12 can arise and burn. In examples of application, a gas flare or flare stack may be used to eliminate fluids such as combustible waste, process gas or other material at oil wells, gas wells, rigs, refineries, chemical plants, refinery process units, chemical process units and so on. A present concern is to continuously monitor the existence of the flame of the pilot 11 for flare 12 . Flare 12 might not necessarily always have a flame 17 if there is no fluid or material to burn; however, flare 12 should be ready to burn with a flame 17 at virtually any time. Such readiness may require a pilot 11 proximate to flare 12 .
[0017] The present approach and apparatus may be used for assuring that a flame from pilot 11 is present for flare 12 . Pilot 11 may incorporate a pilot burner 21 which provides the flame which is present for flare 12 in case the flare needs to be ignited to obtain a flame 17 to burn off gas or whatever is provided via tube or stack 13 . A tube 22 may provide an air and fuel mixture for sustaining the flame of the burner 21 of pilot 11 . A tube 23 with screen and/or deflector 24 may provide a flame front generator (FFG) for igniting the pilot burner 21 in situations where the flame of the pilot burner 21 has ceased. A tube 25 may be connected to tube 22 . Tube 25 may provide high energy (capacitance discharge) ignition up stream of the fuel air mixture delivery to burner 21 from tube 22 . Tubes 23 and 25 may provide alternate forms of ignition for the pilot burner 21 . In burner 21 , there may be a thermocouple and line 26 which may determine whether or not burner 21 is operating with a measurement of temperature at the burner. Thermocouple and line 26 may be connected to a temperature indicator 64 . A concern may be a slow indication of temperature change at burner 21 . The slow indication may imply that if the pilot flame at burner 21 goes out, there may be a delay for the burner 21 assembly to cool down sufficiently to reveal an absence of the pilot 11 flame, and then for an ignition of the pilot flame to occur. Heat from the pilot main flame 17 may inadvertently heat the thermocouple 26 when the pilot flame is extinguished causing a false positive indication of the presence of flame at the pilot burner 21 .
[0018] A high temperature cable 37 may be attached to the end of a rod 39 with a crimp connection, screw connection, braze or weld. Cable 37 may be to go through pipe or conduit 36 to an electrical switch mechanism 38 .
[0019] Rod 32 may be regarded as a multi-mode device. In one mode, rod 32 may be a part of an ionization device for detecting whether the pilot burner 21 flame is on or not. The detecting may be nearly instantaneous. In another mode, rod 32 may be part of an ignition device for igniting the gas/air mixture to pilot burner 21 in an event that the flame in the pilot burner has been extinguished. An operating carrier voltage to rod 32 in an ionization or detection mode may, for instance, be in a range from 100 to 200 volts. The noted operating detection voltage range is an illustrative example but may be of other ranges. The operating voltage to rod 32 in an ignition mode may be in a range from 10 to 20 thousand volts. The noted operating ignition voltage range is an illustrative example but may be of other ranges. Switch mechanism 38 may provide a selected voltage to rod 32 via rod 39 and cable 37 . Rods 32 and 39 in some approaches as may instead be a one-piece rod.
[0020] Insulator 34 may be for high voltage isolation (i.e., up to 20,000 volts) of rod 32 from various items in the environment. The rod 39 portion in insulator 34 may be hermetically sealed from the environment. Insulator 34 may have a corrugated shape or other advantageous shape on its external portion to prevent the various items, such as heavy rain, from causing electrical shorts or failures. Insulator 34 may be positioned relative to flame 17 and/or flame 21 so as to be dried almost instantly. Insulator 34 may be fabricated from other suitable insulating materials besides ceramic.
[0021] A structure 82 may hold and support tube 22 , tube 23 , tube 25 , tube 36 and thermocouple line 26 .
[0022] When a flame is emitted by pilot burner 21 , the combustion process may create and move a field of ionized gas 81 as a part of the burner flame. An effect of an ionized gas field 81 in the flame may result in an electrical voltage or potential occurring between the metal burner 21 and flame rod 32 , as rod 32 may be situated through an opening 79 of burner 21 to be in the ionized gas field 81 . The voltage may be conveyed over a carrier signal emitted by a flame rod signal amplifier 42 . The signal may be conveyed from rod 32 via coupling 33 , rod 39 , coupling 35 , cable 37 , switch 38 and line 43 to amplifier 42 for conditioning into a useful signal at an output 44 . Amplifier 42 and burner 21 may be connected to a common ground 63 .
[0023] Output 44 may indicate whether there is a flame in the pilot burner 21 . If there is no flame, then output 44 via a processor 45 may cause electrical box 38 to send a very high voltage from voltage source 46 via line 47 to rod 32 in form of a spark to ignite the fuel/air mixture from tube 22 so as to re-light the pilot burner 21 . Voltage source 46 and burner 21 may be connected to the common ground 63 .
[0024] Switch 38 , processor 45 , signal amplifier 42 and high voltage source 48 may assembled together as illustrated or alternately constructed together into a single electrical device. Alternately, switch 38 , processor 45 , signal amplifier 42 and high voltage source 46 may be constructed in any combination of combined devices.
[0025] FIG. 2 is a diagram of a flame rod assembly 31 for the detection and ignition mechanism. The mechanism may quickly detect pilot 11 flame failure and provide a prompt ignition of the pilot 11 burner 21 flame. The flame rod may be two components 32 and 39 . Rod 32 may be a flame rod portion which is of a cast and/or machined stainless steel alloy. Coupling 33 may connect rod 32 to an insulator 34 . An end 51 of rod 32 and an end 52 of rod 39 may be threaded and be screwed into threaded counterparts in both ends of coupler 33 . Coupler 33 may be of a cast and/or machined stainless steel alloy. Insulator 34 may be composed of ceramic or other similar appropriate material. Coupling 33 may be attached to insulator 34 with a compression, a brazed, high temperature sealed connection. At a base of insulator 34 may be a stainless steel coupling 35 brazed to the insulator. Coupling 35 may be attached with a weld, braze or threaded ends, to a conduit or pipe 36 , as shown in FIG. 1 . An end 54 of rod 39 and an upper portion of coupling 35 may be threaded for connection to each other. The lower portion of coupling 35 at end 55 may be threaded for connection to pipe or conduit 36 ( FIG. 1 ). Even though the flame rod is shown to be two rods or pieces 32 and 39 connected together by being threaded into coupling 33 , rods 32 and 39 may alternatively be a one piece rod. In either rod structural approach, rod or rod portion 32 may have a significant portion of its unconnected end situated in the pilot burner 21 via opening 79 ( FIG. 1 ).
[0026] FIG. 2 further shows example dimensions of assembly 31 . Dimension 56 of ⅜ inch may be a diameter of rod portions 32 and 39 . Length 57 of rod portion 32 may be 5 and ½ inches. Length 58 of insulator 34 may be approximately 6 inches or more. Diameter dimension 59 of coupling 33 may be approximately 1 inch. A length dimension 61 of coupling 33 may be approximately ¾ inch. A length dimension 62 of coupling 35 may be 2 inches. These dimensions may instead be of other magnitude values.
[0027] FIG. 3 a is a diagram of a configuration of a stainless steel flame rod 65 assembly situated in a pilot burner 66 . A ceramic insulator 67 may be situated on flame rod 65 with compression fittings 68 and 69 brazed to or compressed against and sealing to the ceramic at the ends of insulator 67 . A high temperature cable 71 may be connected to rod 65 at fitting 69 . A mounting bracket 72 may be secured around ceramic insulator 67 .
[0028] FIG. 3 b is a diagram of another configuration of a flame rod 65 assembly. Fittings 68 and 69 may be brazed to the ends of ceramic insulator 67 to secure it to rod 65 . Rod 65 may be bent for another kind of a burner. Rod 65 may have an insulator 73 on a portion of the rod near the burner. A ring-like bracket 74 on insulator 73 may be welded or brazed to a pilot tip.
[0029] FIG. 4 is a diagram of still another configuration of a flame rod 65 assembly. There may be a conducting rod or cable 76 connected to flame rod 65 with a coupling 77 . A ceramic insulator 67 may be around rod 65 and secured with compression fittings 68 and 69 brazed to the ceramic insulator 67 . To the left of fitting 68 in the Figure, there may be a significant length of un-insulated rod 65 until another ceramic insulator 78 is provided on rod 65 beginning at another NPT compression fitting 69 brazed or otherwise sealed to insulator 78 . At the other end of insulator 78 may be another fitting 68 brazed or otherwise sealed to the ceramic insulator 78 . Mounting brackets 72 may be secured around insulators 67 and 78 . Rod 65 may extend from insulator 78 and have a curve for a particular kind of burner. A ceramic insulator 73 may be formed on rod 65 close to the end of the rod. A ring-like bracket 74 formed on insulator 73 may be rested against, welded or brazed to a pilot tip.
[0030] With reference to FIGS. 1-4 , insulators 34 , 67 and 78 may become wet from exposure to environmental elements such as precipitation. Insulators 34 , 67 and 78 may have a length, shape and design so as to minimize the possibility of electrical short circuiting from the flame detection/ignition rods 32 , 39 , 65 , 71 and 76 to grounded supports 35 and 72 . Insulators 34 , 65 and 78 may also be positioned relative to the burner flame 21 and/or the main flare flame 17 such that radiant heat from either or both flame 21 and flame 17 will rapidly (nearly instantaneously) dry a wet insulator 34 , 67 or 78 thereby eliminating a possible short circuit. A short circuit may otherwise render the ignition and flame detection capabilities of the present system inoperable.
[0031] The position the insulators 34 , 67 and 78 from the flare 12 and burner 21 may vary relative to the size of the flare flame 17 and/or the burner 21 flame. However, if the flare flame 17 is extinguished, for instance in a case where there is no material available for burn-off, then the burner 21 flame needs to be sufficiently large or hot enough to keep the insulator dry at virtually all times even for a short period when the burner 21 flame may be accidentally or intentionally be extinguished for some reason. In case of such extinguishment, the insulator should be sufficiently hot enough to maintain a dry condition in a worse case environment of precipitation for a period of time long enough (e.g., thermal inertia) until burner 21 can be relit with a flame.
[0032] The length of the insulators 34 , 67 and 78 should be sufficiently long enough and thick enough to prevent arcing between the rod and, for example a grounded component such as a support strap, during a conveyance of a high voltage via the rod during an igniting of burner 21 . The needed length, thickness and/or diameter of the insulators may depend on the magnitude of the ignition voltage. Also, the dimensions (e.g., diameter, thickness and length) of the insulators should be sufficient so that leakage of ionization signals for indicating a presence or non-presence of a burner 21 flame is sufficiently small so that the signals are strong enough at the recipient end for detection. The material content of the insulator should also have a very small conductance factor. Ceramic may be an example of such insulator material.
[0033] The shape of insulators 34 , 67 and 78 may aid in reduction of the effects of precipitation on the insulators. An example design may incorporate a corrugated external surface on the insulators. The shape of the insulators may be selected from a variety of designs. Further, the insulators may have straight and/or curved configurations. Other design factors of the insulators may be implemented.
[0034] In sum, the factors of insulators 34 , 67 and 78 such as position relative to and distance from flare 12 and/or burner 21 , insulator temperature, length, thickness, diameter, material content, shape, configuration and other factors may be interdependent (e.g., in terms of quantification) in that, for example, a strong factor may compensate for a weak factor. The design and layout of the flare 12 and burner 21 may indicate factors needed for effective insulators. The location and environment of the flare and burner may indicate considerations such as cold, humid, hot, dry, windy, calm and other conditions, which may dictate needed specifics for insulators.
[0035] In the present specification, some of the matter may be of a hypothetical or prophetic nature although stated in another manner or tense.
[0036] Although the present system and/or approach has been described with respect to at least one illustrative example, many variations and modifications will become apparent to those skilled in the art upon reading the specification. It is therefore the intention that the appended claims be interpreted as broadly as possible in view of the related art to include all such variations and modifications.
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A system having a flame rod assembly for operation in a high temperature pilot burner. The assembly is designed for operation in temperatures from about −40 to 1100 degrees C. The system may operate in inclement weather involving high speed winds and significant amounts of moisture and rain to hurricane storm force levels and rates. The system incorporates an electrical apparatus which may provide flame sensing and ignition via the flame rod assembly incorporating a quick drying insulator around a rod of the assembly to ensure proper operation of the electrical apparatus.
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FIELD OF THE INVENTION
The present invention pertains to a pressure relief valve with a closing element having a closing force that can be set and with a threaded sleeve that can be actuated by means of a handwheel for generating a variable closing force of the closing element as well as a valve shaft, which extends within the threaded sleeve toward the handwheel and is connected to the closing element.
BACKGROUND OF THE INVENTION
A pressure relief valve of this type has become known from DE 38 01 444 A1. The prior-art valve is used in the breathing gas line of an anesthesia apparatus or respirator to make possible the manual as well as the spontaneous respiration by the corresponding switching of a changeover switch. Thus, the valve is opened in the “manual respiration” mode by a possible overpressure in the breathing gas line against a preset closing force in order to release excess gas. The closing force is set by means of a handwheel and a valve spindle, and, depending on the position of the handwheel, a valve spring is compressed more or less strongly in order to thereby vary the opening pressure. In the “spontaneous respiration” mode, the closing element is released, by contrast, by the changeover switch, so that the closing force does not act any longer and the breathing gas can flow off without an appreciable expiration resistance. If the changeover switch is again shifted in the “manual respiration” direction, the original closing force again becomes established without corrections having to be made on the handwheel of the valve.
If complete pressure relief of the breathing gas line must be briefly performed during the manual respiration, this can be performed only if the changeover switch is shifted in the “spontaneous respiration” direction. However, it may now happen, especially when other settings also have to be performed on the anesthesia apparatus or respirator, that the operator forgets to shift the changeover switch to the “manual respiration” position. Delays may thus arise for the user in terms of the continuation of the manual respiration.
SUMMARY OF THE INVENTION
The basic object of the present invention is to improve a pressure relief valve of this type such that both the setting of the closing force and the brief release of the closing element can be performed with a single setting element without changing the set closing force in the process.
According to the invention, a pressure relief valve for flowing media is provided with a closing element having a closing force that can be set. A threaded sleeve is provided that can be actuated by a handwheel to generate a variable closing force of the closing element. A valve shaft extends within the threaded sleeve toward the handwheel and is connected to the closing element. The connecting element transmits the rotary movement of the handwheel to the threaded sleeve and makes possible a lifting movement. The connecting element is provided between the handwheel and the threaded sleeve. The connection of the valve shaft to the handwheel is designed such that the valve shaft follows the lifting movement of the handwheel.
The advantage of the present invention is essentially that the handwheel is connected to a threaded sleeve, which is used to set the closing force of the closing element, such that the rotary movement of the handwheel is transmitted to the threaded sleeve, on the one hand, and the handwheel can be actuated in relation to the threaded sleeve in such a way that it can perform a lifting movement, on the other hand. The handwheel is rigidly connected to the valve shaft accommodating the closing element, so that the closing element is also lifted off from the valve seat during the release of the handwheel.
The handwheel advantageously has a cylindrical pin, which is provided with external teeth and is directly connected to the valve shaft. The threaded sleeve, which is engaged by the pin, has, by contrast, internal teeth of a shape corresponding to the external teeth. Due to the meshing of the teeth, the rotary movement of the handwheel is transmitted to the threaded sleeve, on the one hand, while a relative movement is possible in the axial direction of the handwheel in relation to the threaded sleeve, on the other hand.
The threaded sleeve advantageously has three helically extending grooves located next to one another. The threaded sleeve is accommodated in a stationary cylinder, which has projections engaging the grooves. During its rotation, the threaded sleeve is displaced in the cylinder in the upward or downward direction. The threaded sleeve is in turn connected via a compression spring to the closing element, so that the closing force of the closing element is changed during the upward and downward movement of the threaded sleeve.
The grooves of the threaded sleeve advantageously have a different pitch in one section in order to make it possible to change the closing force of the closing element progressively. It may happen in the case of a linear adjustment of the closing force that a maximum closing force of, e.g., 70 mbar cannot be set with an acceptable scale in case of a preset angle of rotation of less than 360°. It should be taken into consideration in the case of such pressure relief valves that an accurate settability must be ensured in the range of up to about 40 mbar, whereas a coarse setting is sufficient at higher pressure values. Such a requirement can be met only if the closing force changes linearly up to about 40 mbar or 50 mbar and a progressive characteristic is selected at stronger closing forces. This characteristic can be set by selecting the pitch of the external thread on the threaded sleeve.
One exemplary embodiment of the present invention is shown in the figure and will be explained in greater detail below. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which the preferred embodiment of the invention is illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal sectional view of a pressure relief valve according to the present invention;
FIG. 2 is an exploded view of some components of the pressure relief valve according to FIG. 1 ;
FIG. 3 is a perspective view of the cylinder;
FIG. 4 is a top view of the cylinder in direction of view A according to FIG. 3 ;
FIG. 5 is a side view of the pressure relief valve with the partially cut-away handwheel; and
FIG. 6 is a side view according to FIG. 5 , but for a position of the handwheel close to its end position for spontaneous respiration.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings in particular, FIG. 1 shows the longitudinal section of a pressure relief valve 1 with a handwheel 2 , a threaded sleeve 3 , which is connected to the handwheel 2 in such a way that it can perform a lifting movement and a rotary movement, and grooves 4 located on the outside, as well as a valve shaft 5 rigidly connected to the handwheel for a valve disk 6 as a closing element guided therein in such a way that it can perform a lifting movement. The valve disk 6 has a guide bar 7 protruding into the valve shaft 5 with a bead 8 , wherein the bead 8 is fixed in the valve shaft 5 by means of a retaining ring 9 . A compression spring 11 is located between the valve disk 6 and a contact surface 10 at the threaded sleeve 3 , but only the turn of the compression spring 11 in the area of the contact surface 10 is shown for the sake of greater clarity. The threaded sleeve 3 is accommodated in a cylinder 12 , which has projections 13 distributed over the circumference on its inner side, the projections 13 engaging the grooves 4 . Only one of the projections 13 is shown in FIG. 1 for the sake of greater clarity.
The pressure relief valve 1 has on its outer side a protective sleeve 14 , which is in turn connected to the handwheel 2 via a first snap-in connection 15 and to a support ring 17 via a second snap-in connection 16 , wherein the support ring 17 is axially displaceable on the outer side of the cylinder 12 and is supported against the cylinder 12 via a spring 18 . The threaded sleeve 14 is in contact on the underside with a guide ring 19 , which is fastened to the cylinder 2 via locking cams 20 (FIG. 2 ).
FIG. 2 illustrates in an exploded view the handwheel 2 , the protective sleeve 14 with the first snap-in connection 15 , the threaded sleeve 3 and the cylinder 12 . Identical components are designated with the same reference numbers as in FIG. 1 . The threaded sleeve 3 is illustrated in the perspective view for the sake of greater clarity.
The handwheel 2 has on its underside a pin 21 with external teeth 22 , which pin engages the threaded sleeve 3 with internal teeth 23 having a shape corresponding thereto. A rotary movement of the handwheel 2 is transmitted by means of the teeth 22 , 23 to the threaded sleeve, and an axial displacement of the handwheel 2 in relation to the threaded sleeve 3 is also possible. The protective sleeve 14 has a scale 24 on its outside for various pressure values as well as an end position 25 for spontaneous respiration.
The grooves 4 on the threaded sleeve 3 comprise three individual grooves 41 , 42 , 43 , which are arranged offset by 120°, extend helically on the outside of the threaded sleeve 3 and have end sections 26 with an increased pitch. On its top side pointing toward the handwheel 2 , the cylinder 12 has a carrier 27 , which is located beneath the handwheel 2 .
FIG. 3 shows a perspective view of the cylinder 12 with the projections 13 located on the inside, the carrier 27 and the locking cams 20 for the guide ring 19 corresponding to FIG. 1 .
FIG. 4 shows a top view of the cylinder 12 in direction of view A according to FIG. 3 with three projections 13 , which are offset by 120° in relation to one another and engage the grooves 41 , 42 , 43 of the threaded sleeve 3 , FIG. 2 . The cooperation between the grooves 41 , 42 , 43 and the projections 13 causes the threaded sleeve 3 to be axially displaced within the cylinder 12 upward or downward during its rotation.
FIG. 5 shows a side view of the pressure relief valve 1 with a partially cut-away handwheel 2 . The carrier 27 of the cylinder 12 extends here on an annular sliding surface 28 , which ends in an oblique plane 29 . The sliding surface 28 has notches 30 , which correspond to settings of the scale 24 and send a tactile feedback for settings, which equal an integer multiple of 10 mbar, via an elastic locking member 31 , which is located at the carrier 27 .
The scale 24 comprises a range of 5 mbar to 70 mbar, wherein the setting takes place in equidistant sections between integer multiples of 10 mbar up to about 50 mbar, whereas the end sections 26 of the grooves 41 , 42 , 43 , FIG. 2 , are used with a progressive adjustment of the compression spring 11 ( FIG. 1 ) between 50 mbar and 70 mbar. The progressive adjustment of the closing force in the area between 50 mbar and 70 mbar is necessary to still be able to set the maximum of 70 mbar with sufficient accuracy at a maximum angle of rotation of less than 360°. A compromise must be found here between the most accurate possible setting of the opening pressure up to about 50 mbar with a sufficiently large setting angle and a maximum opening pressure of 70 mbar, which can be set with greater tolerance, within a maximum adjustment angle of less than 360° for the handwheel.
FIG. 6 illustrates a side view of the pressure relief valve 1 , in which the handwheel 2 is cut up in the area of the oblique plane 29 compared with FIG. 5 . The oblique plane 29 becomes active when the handwheel 2 is rotated below a setting of 5 mbar of the scale 24 in the direction of the end position 25 for spontaneous respiration. The handwheel 2 is now raised by ΔH together with the protective sleeve 14 by the carrier 27 and the locking member 31 , and the locking member 31 snaps into the recess 32 in the end position 25 and blocks the handwheel 2 in the end position 25 .
The pressure relief valve 1 according to the present invention operates as follows:
Depending on the rotary movement of the handwheel 2 ( FIG. 1 ) the threaded sleeve 3 is moved upward or downward, and the pretension of the compression spring 11 which is in contact with the valve disk 6 changes in the process. The valve disk 6 now lies on a valve seat of a breathing gas line, where the valve seat is not shown specifically and the breathing gas line is not shown. Depending on the pretension of the compression spring 11 , different pressure values will be obtained corresponding to the scale 24 , at which pressure values the valve disk 6 is lifted off from the valve seat, i.e., at which the pressure relief valve 1 opens and excess breathing gas can escape. Regardless of the angular position of the handwheel 2 within the scale 24 , the pressure relief valve 1 can be opened at any time without the setting performed previously having to be changed. The handwheel 2 is pulled for this purpose upward along the arrow 33 , while the valve shaft 5 firmly connected to the handwheel 2 , and the guide bar 7 with the valve disk 6 , follow the movement of the of the handwheel 2 . As can be determined from FIG. 2 , the pin 21 with the external teeth 22 slides within the internal teeth 23 of the threaded sleeve 3 during the pulling movement of the handwheel 2 . The spring 18 ( FIG. 1 ) is compressed during the pulling movement of the handwheel 2 , and it exerts a restoring force on the handwheel 2 via the support ring 17 and the protective sleeve 14 .
As can be determined from FIG. 6 , the open position of the pressure relief valve 1 is also reached when the handwheel 2 is rotated from the scale 24 in the direction of the end position 25 . The locking member 31 now slides along the oblique plane 29 up to the recess 32 , as a result of which the handwheel is raised by ΔH together with the protective sleeve 14 .
While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
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A pressure relief valve for flowing media has a closing element ( 6 ), whose closing force can be set with both the setting of the closing force and the brief release of the closing element ( 6 ) performed with a single setting element. Teeth ( 22, 23 ) are provided, by which the threaded sleeve ( 3 ) can be actuated such that it can perform a rotary movement and a lifting movement can be performed between the handwheel ( 2 ) and the threaded sleeve ( 3 ). The teeth are provided between a pin ( 21 ) of the handwheel ( 2 ) for setting the closing force and a threaded sleeve ( 3 ). The closing element ( 6 ) is connected to the handwheel ( 2 ) such that the closing element ( 6 ) follows the lifting movement of the handwheel ( 2 ).
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation-in-part of U.S. patent application Ser. No. 10/562,100. U.S. patent application Ser. No. 10/562,100 is a national-stage application of International Patent Application No. PCT/CH04/000384. International Patent Application No. PCT/CH04/000384 was filed on Jun. 24, 2004. International Patent Application No. PCT/CH04/000384 claims priority from Swiss Patent Application No. 01259/03, which was filed on Jul. 18, 2003. U.S. patent application Ser. No. 10/562,100, International Patent Application No. PCT/CH04/000384, and Swiss Patent Application No. 01259/03 are each incorporated herein by reference.
BACKGROUND
[0002] Pneumatic supports in the form of inflatable hollow bodies are known in several variations, for example, from U.S. Pat. No. 3,894,307 (D1) and WO 01/73245 (D2) of the same applicant as the present application. If such a support is subjected to a transversal load, the primary objective consists of absorbing the occurring tensile forces and shearing forces without causing the support to buckle.
[0003] In D2, the axial compressive forces are absorbed by a compression member while the axial tensile forces are absorbed by two tension elements that are helicoidally wound around the hollow body and fixed on the ends of the compression member. The pneumatic portion of the structural elements described in this publication has the function of stabilizing the compression members against buckling.
[0004] In D 1 , several hollow bodies are combined in a parallel fashion so as to form a bridge. In this case, the tensile forces are absorbed by a flexible cover that encompasses all hollow bodies, and the compressive forces are absorbed by the bridge plate that is composed of strung-together elements. The elements are laterally fixed on the cover that encompasses the hollow bodies and thusly secured against buckling.
[0005] D2 is the document most closely related to the present invention. The pneumatic structural element disclosed in D2 contains at least two tension elements that are relatively long in comparison with the length of the structural element due to their helicoidal arrangement around the hollow body. Under a load, this leads to a more significant deflection than in instances, in which shorter tension elements are used. When such an element is used as a support, the nodes for absorbing the bearing forces which lie on top of the structural element rather than on the outermost end thereof require complicated bearing constructions. In D 1 , the tension element consists of a large-surface cover that is only able to absorb tensile forces to a limited degree and can only be stretched with a significant technical expenditure.
[0006] The invention is based on the objective of developing pneumatic supports with tension and compression members that have a high flexural strength, can be manufactured in a simple and cost-efficient fashion and easily assembled into complex structural components and structures, for example, roofs and bridges, wherein these structural components and structures can also be erected very quickly and easily connected to conventional constructions.
[0007] With respect to its essential characteristics, the solution to this objective is disclosed in the characterizing portion of claim 1 , wherein other advantageous embodiments are disclosed in the succeeding claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The object of the invention is described in greater detail below with reference to several embodiments that are illustrated in the enclosed figures. The figures show:
[0009] FIGS. 1 a, b , a schematic side view of and a cross section through a first embodiment of a pneumatic support;
[0010] FIGS. 2 a, b , a schematic side view of and a cross section through a second embodiment of a pneumatic support;
[0011] FIGS. 3 a, b , a schematic side view of and a cross section through a third embodiment of a pneumatic support;
[0012] FIG. 4 , a schematic side view of a first embodiment of the non-positive connection of the compression/tension elements;
[0013] FIG. 5 , a schematic side view of a second embodiment of the non-positive connection of the compression/tension elements;
[0014] FIG. 6 , a schematic top view of one embodiment of a compression/tension element;
[0015] FIGS. 7-9 , schematic side views of three exemplary shapes of a hollow body;
[0016] FIGS. 10-12 , schematic longitudinal sections through three embodiments of hollow bodies that are divided into several pressure chambers;
[0017] FIG. 13 , a schematic side view of a fifth embodiment of a pneumatic support, and
[0018] FIGS. 14 a - c , schematic representations of a first application example for the connection of several pneumatic supports.
DETAILED DESCRIPTION
[0019] Various embodiments of the present invention will now be described more fully with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, the embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
[0020] FIG. 1 shows a schematic representation of a first embodiment of the object of the invention. A support 1 consists of an elongated hollow body 2 that is tapered toward the ends, a compression bar 3 and a tension element 4 . The hollow body 2 is formed by a cover 7 of a gas-tight material that is flexible, but has limited stretchability. Since it is difficult to combine these properties in one material, the hollow body 2 is advantageously composed of a flexible outer cover 7 of limited stretchability and an elastic, gas-tight inner bladder. The hollow body 2 can be pressurized with compressed gas by means of a valve 6 . The compression bar 3 and the tension element 4 adjoin the hollow body 2 along diametrically opposite surface lines thereof. The compression bar 3 is connected to the hollow body 2 along this surface line with suitable means. This may be realized, for example, with a welt-type connection, pockets or several belts that encompass the hollow body 2 . The ends of the tension element 4 are positively fixed to the ends of the compression bar 3 . This first embodiment of a pneumatic support 1 is suitable for applications, in which compressive forces act upon the support 1 in only one direction. This applies, for example, to a bridge support that is subjected to a load consisting of the own weight of the bridge and the imposed load. The compression bar 3 and the tension element 4 lie in the active plane of the load vector that acts upon the compression bar 3 and points in the direction of the tension element 4 . The hollow body 2 prevents the compression bar 3 from buckling such that the material of the compression bar 3 can be stressed up to the yield point. This yield point lies at a significantly higher force than the buckling load of a bar. In addition, the hollow body 2 spatially separates the compression bar 3 and the tension element 4 from one another. Such a construction is characterized in a low consumption of materials, a low weight and a high load bearing capacity. FIG. 1 a shows a side view, and FIG. 1 b shows a section along the line AA.
[0021] FIG. 2 shows a second embodiment of a pneumatic support 1 that can be used, for example, for roof constructions. At high winds, certain regions of a roof can be subjected to significant wind suction that more than compensates the load in the vertical direction. In a thusly utilized support 1 , this results in a reversal of the dynamic effect. In FIG. 2 , the sole bottom tension element 4 of FIG. 1 was replaced with a compression/tension element 5 ; i.e., an element that is able to absorb compressive forces as well as tensile forces. The simplest and most commonly used compression/tension element 5 consists of a second compression bar 3 . For example, such a bar can be manufactured of steel or aluminum because these materials have similarly adequate tensile and compressive properties. Materials with adequate compressive but insufficient tensile properties can be prestressed with tension cables such that they can also be used for absorbing tensile forces. One example of a material that is provided with a high tensile strength in this fashion is concrete prestressed with steel cables. In FIG. 2 , two compression/tension elements 5 encompass the hollow body 2 along two diametrically opposite surface lines. The compression/tension elements 5 are also fixed to the surface lines in order to prevent buckling of these elements under a load. The compression/tension elements 5 are connected to one another at their ends and serve as tension element or as compression element depending on the direction of the load. The scope of the invention includes embodiments, in which the two compression/tension elements 5 differ with respect to their compressive or tensile properties. For example, the compression/tension elements 5 may be realized such that the upper element is able to withstand higher compressive forces than the lower element. FIG. 2 a shows a side view, and FIG. 2 b shows a section along the line BB.
[0022] A third embodiment of the object of the invention is illustrated in FIG. 3 . In the above-described examples, the supports 1 are essentially subjected to a load in the vertical plane. However, if a support 1 is arranged vertically in an upright position and used as the column, the transversal forces essentially occur no longer in one plane only, but may subject the support to loads of similar intensity from all sides, for example, a wind load. In order to withstand forces from all sides, the support 1 shown in FIG. 3 is provided with three compression/tension elements 5 that are uniformly distributed over the cross section of the hollow body 2 and fixed thereto along surface lines, wherein said compression/tension elements are non-positively connected to one another at their ends. When utilizing such a support 1 as a supporting column, it is also subjected to an axial load. The scope of the invention includes embodiments, in which more than three compression/tension elements 5 are distributed over the hollow body 2 . FIG. 3 a shows an isometric representation, and FIG. 3 b shows a cross section along the line CC.
[0023] FIGS. 4 and 5 show different options for connecting the compression/tension elements 5 at the ends of the support 1 . In FIG. 5 , the compression/tension elements 5 are connected to an end piece 9 that may encompass, for example, the end of the hollow body 2 . An axle 8 may be fixed, for example, in the end piece 9 in order to incorporate the support into an interconnected construction; alternatively, the end piece 9 could be designed such that it can be directly placed on a bearing.
[0024] In FIG. 5 , the ends of the compression/tension elements 5 are connected by means of an axle 8 .
[0025] FIG. 6 shows an advantageous embodiment of a compression/tension element 5 that has a wider cross-section toward the ends and therefore a superior flexural strength. This construction of the compression/tension element 5 takes into account the fact that the compression/tension elements 5 need to absorb higher bending moments at the ends of the support 1 than in the center of the support 1 . In FIG. 5 , a greater flexural strength toward the ends of the compression/tension elements 5 is achieved due to this increased cross section.
[0026] FIGS. 7-9 show different embodiments of the hollow body 2 . The cross section of the hollow body 2 is essentially circular over the entire length. However, the scope of the invention also includes embodiments with other cross sections or cross sections that vary over the length of the hollow body, for example, a flattening cross-section in order to achieve a superior lateral stability. FIG. 7 shows an embodiment of an asymmetric hollow body 2 that has a more significant curvature on the upper side of the support 1 and a flatter curvature on the underside. Supports 1 with thusly shaped hollow bodies 2 only deflect slightly when they are used as bridges and subjected to loads from one side. FIG. 7 shows a hollow body 2 that is realized in a rotationally symmetrical fashion referred to the longitudinal axis. This hollow body essentially consists of a cylindrical tube with pointed ends. If viewed in the form of a longitudinal section, the hollow body 2 shown in FIG. 9 is realized in a gutate fashion.
[0027] FIGS. 10-12 show different embodiments with hollow bodies that are divided into several chambers 10 . In FIG. 10 , the hollow body is divided into several chambers 10 that occupy the entire cross section of the hollow body 2 transverse to the longitudinal axis. These chambers 10 can be pressurized to different degrees. The embodiment shown represents a variation with three pressure levels. In this case, the following applies: P 0 <P 1 <P 2 <P 3 . The pressure increases toward the ends of the support 1 . In FIG. 11 , the hollow body 2 is divided into several chambers 10 that are essentially arranged parallel to the longitudinal direction and extend over essentially the entire length of the hollow body 2 . FIG. 12 shows a combination of longitudinally and transversely divided chambers 10 . One common aspect of the embodiments shown in FIGS. 10-12 is that the hollow body consists of a flexible cover 7 of limited stretchability, for example, of aramide-reinforced fabric. Several bladders 11 of a stretchable, gas-tight material are inserted into this cover 7 of limited stretchability. In addition, webs 12 embedded into the outer cover 7 may serve for essentially defining the position of the pressurized bladders 11 and thusly prevent the bladders 11 from shifting within the cover 7 . This is illustrated in FIG. 10 on one side of the support 1 . However, it would also be conceivable and fall under the scope of the invention to divide a gas-tight cover 7 with gas-tight webs 12 into several chambers 10 as shown in FIGS. 11 , 12 .
[0028] FIG. 13 shows another embodiment of the object of the invention. A support 1 according to FIG. 2 is curved upward in an arc-shaped fashion and therefore has a concave underside and a convex upper side. The distance between the two ends of the support 1 can essentially be fixed by clamping the ends into abutments or by means of an external tension element 14 . When the support 1 is subjected to a downwardly acting load, the two compression/tension elements 5 are compressed while the tensile forces are absorbed by the abutments or the tension element 14 .
[0029] FIGS. 14 a - c show an application example for pneumatic supports 1 in the construction of a bridge. Two supports 1 according to FIG. 1 are combined into a lightweight bridge by means of a roadway construction 13 that connects the supports and lies on the compression bars 3 . Since a person skilled in the art is familiar with different options for manufacturing such a roadway, for example, in the form of a sandwich structure of fiber-reinforced plastics, this aspect is not discussed in detail. FIG. 14 a shows a top view of the bridge, FIG. 14 b shows a section along the line DD, and FIG. 14 c shows a section along the line EE.
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A pneumatic support comprises a long hollow body, tapering towards the ends and two pressure/tension elements. The hollow body is embodied by a sleeve of gas-tight, flexible, non-stretch material. Said sleeve can be formed from two layers, an external non-stretch, flexible sleeve and an inner gas-tight elastic bladder. The hollow body can be pressurised with compressed gas by means of a valve. The both pressure/tension elements lie along diametrically opposed surface lines of the hollow body on the same and are partly or completely frictionally connected to the hollow body along said surface lines. The ends of the pressure/tension elements are frictionally connected to each other.
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[0001] This application claims the benefit of Taiwan application Serial No. 105103771, filed Feb. 4, 2016, the subject matter of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] Field of the Invention
[0003] The invention relates in general to a touch display device, and more particularly to a touch display device capable of increasing a touch report rate and an associated control method.
[0004] Description of the Related Art
[0005] A touch display device is an image display device that includes an input device. The display device may be, for example, a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDD) or an electroluminescent display (ELD). A touch display device allows a user to input an instruction or message by touching or pressing a touch sensor on a screen through a finger or a stylus, while viewing an image displayed on the screen of the display device.
[0006] A conventional touch display device is formed by additionally attaching a touch panel including touch sensors on a common display screen without a touch function. Such type of touch display device is generally referred to as an add-on type touch panel. Compared to a common display screen without a touch function, an add-on type touch panel usually suffers from issues of a larger thickness and poorer light transmittance.
[0007] To overcome the issues above and to at the same time eliminate the additional manufacturing process of attaching a touch panel, an in-cell touch technology has been developed for a touch display device. For example, an in-cell touch panel directly places touch sensors into a display screen. In other words, when the manufacture of the display screen is complete, the touch sensors are simultaneously formed without involving the additional process of attaching a touch panel.
[0008] For an in-cell touch screen, the time for updating data of all pixels thereon is referred to as one display frame period, and is usually defined by a cycle of a vertical synchronization signal. The reciprocal of the display frame period is generally referred to as a frame update rate, or simply frame rate.
[0009] In an in-cell touch screen, some electrodes are required to handle dual functions of image display and touch sensing. Therefore, a time-division method is frequently adopted for these electrodes to sometimes control the function of image display and sometimes handle the function of touch sensing. One simplest is approach is that, after the data of all of the pixels is updated once and before the next display frame period begins, touch sensing is performed and a touch report is transmitted. A frequency of generating touch point information is usually referred to as a touch report rate. In a common in-cell touch screen, the touch report rate is equal to the frame rate. For example, if the frame rate is 60 Hz, the touch report rate of the common in-cell touch screen is also 60 Hz.
[0010] FIG. 1 shows an LCD panel 10 and an associated control circuit, which together serve as an example of a touch display device. On the LCD panel 10 , a gate driver circuit 12 , gate lines G 1 , G 2 , . . . and G N , and data lines D 1 , D 2 , . . . and D M are formed. The LCD panel 10 includes an active region 14 , in which a gate line and a data line 14 intersect to control a pixel. A data driving circuit 16 controls the data lines D 1 , D 2 , . . . and D M . A timing controller 18 provides a corresponding signal to the gate driver circuit 12 to cause the gate driver circuit 12 to sequentially scan the gate lines G 1 , G 2 , . . . and G N . The timing controller 18 also writes a digital signal into a register of the data driving circuit 16 according to an audio/video signal, and converts the digital signal to an analog data signal to drive the data lines D 1 , D 2 , . . . and D M .
[0011] FIG. 1 further depicts an equivalent circuit in a pixel Cell nm correspondingly controlled by the gate line G n and the data line Dm. The pixel Cell nm may be a pixel of any of the colors red, green and blue. The gate line G n may turn on or turn off a thin-film transistor (TFT) TM nm . Through the turned on TFT TM nm , the data driving circuit 16 may store a data voltage V nm in a capacitor C nm of the pixel. A difference between a common voltage V COM on a common electrode and a data voltage V nm on a data electrode determines a twist level of the liquid crystals between the two electrodes, and thus determines a level of transmittance of light emitted from a backlight source (not shown) through the pixel Cell nm .
[0012] FIG. 2 shows an operating timing applied to the touch display device in FIG. 1 . The LCD panel 10 operates in a progressive scan mode. The gate lines G 1 , G 2 , . . . and G N are scanned for display in a period 20 . The gate driver circuit 12 sequentially scan the gate lines G 1 , G 2 , . . . and G N . For example, the gate driving circuit 12 first pulls the gate line G 1 to a high voltage while keeping the other gate lines at a low voltage. As such, the TFT of all of the pixels connected to the gate line G 1 are all turned on. At this point, the data driving circuit 16 may write appropriate data voltages into all of the pixels connected to the gate line G 1 through the data lines D 1 , D 2 , . . . and D M , respectively. The gate driver circuit 12 then pulls the gate line G 1 down to a low voltage, and pulls the gate line G 2 to a high voltage, and the data driving circuit 16 writes appropriate data voltages into all of the pixels connected to the gate line G 2 through the data lines D 1 , D 2 , . . . and D M , respectively. Thus, in the period 20 , the data voltages of all of the pixels in FIG. 1 are updated. An entire image formed by all of the pixels in FIG. 1 is commonly referred to as a frame. In other words, one frame is updated in the period 20 .
[0013] In a period 22 , touch detection and report are performed. After one frame is updated in the period 20 , touch detection and report may be performed using the data lines D 1 , D 2 , . . . and D M or the common electrode in FIG. 1 in the period 22 to provide one touch report.
[0014] In periods 24 and 26 , the periods 20 and 22 are repeated. It should be noted that, as shown in FIG. 2 , the periods 20 and 22 are completed in one frame period T FRAME , and the periods 24 and 26 are completed in a next frame period T FRAME . If the frame rate in FIG. 2 is 60 Hz, the frame period T FRAME in FIG. 2 is 1/60 second, and the touch report rate, the same as the frame rate, is also 60 Hz.
[0015] However, to provide a more sensitive and fast touch response, some software system manufacturers demand a touch report rate to be as high as 100 Hz. Therefore, there is a need for a solution for increasing the touch report rate.
SUMMARY OF THE INVENTION
[0016] According to an embodiment of the present invention, a touch display device includes a display panel, a gate driver, a touch detection circuit and a timing controller. The display panel includes a plurality of first gate lines and a plurality of second gate lines. One least one of the first gates lines is located between two adjacent second gate lines, and at least one of the second gate lines is located between two adjacent first gate lines. The display panel includes a plurality of sensing electrodes for touch detection. The gate driver drives the first and second gate lines. The touch detection circuit is connected to the sensing electrodes, and provides a first touch report and a second touch report within in one single frame period. The timing controller controls the gate driver to scan the first gate lines and the second gate lines in a first period and a second period, respectively, within the one single frame period. The first touch report is between the first and second periods, and is provided by the touch detection circuit.
[0017] According to another embodiment of the present invention, a control method for a touch display device is provided. The touch display device includes a display panel. The display panel includes a plurality of gate lines and a plurality of second gate lines corresponding to a first field and a second field of a frame, respectively, and a plurality of sensing electrodes for touch detection. Within one single frame period, the control method includes: scanning the first gate lines to update the first field at the display panel; controlling the sensing electrodes to perform touch detection and providing a first touch report; scanning the second gate lines to update the second field at the display panel; and controlling the sensing electrodes to perform touch sensing and providing a second touch report. At least one of the first gate lines is located between two of the second gate lines, and at least one of the second gate lines is located between two of the first gate lines.
[0018] The above and other aspects of the invention will become better understood with regard to the following detailed description of the preferred but non-limiting embodiments. The following description is made with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 (prior art) is an LCD panel and an associated control circuit jointly serving as an example of a touch display device;
[0020] FIG. 2 (prior art) is an operating timing applied to the touch display device in FIG. 1 ;
[0021] FIG. 3 is a touch display device according to an embodiment of the present invention;
[0022] FIG. 4 shows a touch integrated circuit and a common electrode plate located in an active region;
[0023] FIG. 5 is an example of two gate driver circuits;
[0024] FIG. 6 is a diagram of an operating timing applied to the touch display device in FIG. 3 ;
[0025] FIG. 7 shows signal timings of FIG. 3 ; and
[0026] FIG. 8 is an operating timing according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0027] Throughout the disclosure, as anticipatable by one person skilled in the art based on the teaching of the disclosure, same denotations represent elements having identical or similar structures, functions and principles. To keep the disclosure concise and simple, details of elements with the same denotations are not repeatedly described.
[0028] FIG. 3 shows a touch display device 30 according to an embodiment of the present invention. The touch display device 30 includes an LCD panel 31 , a data driving circuit 36 , a timing controller 38 and a touch integrated circuit 39 .
[0029] Two gate driving circuits 32 l and 32 r , gate lines G 1 , G 2 , . . . and G N , and data lines D 1 , D 2 , . . . and D M are formed on the LCD panel 31 . The LCD panel 31 includes an active region 34 , in which one gate line intersects one data line to substantially control one pixel, as an example shown in FIG. 1 . Parts in FIG. 3 that are identical or similar to those in FIG. 1 are omitted for brevity. In FIG. 3 , the gate lines G 1 , G 2 , . . . and G N are divided into two groups—a first group including odd-number gate lines G 1 , G 3 , . . . and G N-1 , and the other group including even-number gate lines G 2 , G 4 , . . . and G N . The gate line G 2 is between the gate lines G 1 and G 3 , and the gate line G 3 is between the gate lines G 2 and G 4 . In the embodiment in FIG. 3 , assume that N is an even number. The gate driving circuits 32 l and 32 r collectively form a gate driver that controls all of the gate lines G 1 , G 2 , . . . and G N . The gate driving circuits 32 l and 32 r are located outside the active region 34 , and are near left and right sides of the active region 34 , respectively. The gate driving circuit 32 l may drive the odd-number gate lines but not the even-number gate lines, and the gate driving circuit 32 r may drive the even-number gate lines but not the odd-number gate lines.
[0030] The data driving circuit 36 controls the data lines D 1 , D 2 , . . . and D M . The timing controller 38 provides corresponding signals to the gate driving circuits 32 l and 32 r and controls the data driving circuit 3 . Associate details of the operating timing are to be described shortly.
[0031] FIG. 4 shows an example of the touch integrated circuit 39 and common electrode plates 37 located in the active region 34 for explaining the touch detection performed by the touch display device 30 . Each of the common electrode plates 37 corresponds to one or multiple pixels to serve as a sensing electrode. The touch integrated circuit 38 serves as a touch detection circuit, and may sequentially measure self capacitance changes of the common electrode plates 37 to determine whether a touch point occurs and a position of the touch point to perform touch report. The LCD panel 31 is a capacitive touch panel. In one embodiment, the touch integrated circuit 39 may sequentially measure individual self capacitance changes of the common electrode plates 37 on one entire row one row after another to perform touch detection and report. When the pixels on the LCD panel 31 are being updated, the touch integrated circuit 39 provides the common voltage V COM in a constant value to all of the common electrode plates 37 , and so the touch display device 30 cannot simultaneously perform touch detection and report. The present invention is not limited to the structure shown in FIG. 4 . It should be noted that, the structure in FIG. 4 is an example for explaining one type of structure used for touch detection, and how touch detection and report cannot be simultaneously performed with updating the pixels.
[0032] FIG. 5 shows an example of the gate driving circuits 32 l and 32 r , each being a shift register. The timing controller 38 provides a clock signal CLK and a starting pulse SP ODD to the gate driving circuit 32 l , but provides the clock signal CLK and a starting pulse SP EVEN to the gate driving circuit 32 r . Time points at which the starting pulse SP ODD and the starting pulse SP EVEN occur are determined by the timing controller 38 . The starting pulse SP ODD first shifts to the gate line G 1 , the gate line G 3 , the gate line G 5 , and so on, and eventually leaves the gate line G N-1 as the clock signal CLK switches. Similarly, starting from the gate line G 2 , the starting pulse SP EVEN gradually shifts to the gate line G N and eventually leaves the gate line G N as the clock signal CLK switches. The gate driving circuits 32 l and 32 r may be integrated in the LCD panel 31 . For example, the switches in the gate driving circuits 32 l and 32 r may be formed by TFTs identical or similar to the TFT TM nm in the pixels.
[0033] FIG. 6 shows an operating timing applied to the touch display device 30 in FIG. 3 , and FIG. 7 shows signal timings of FIG. 3 . In this embodiment, the touch display device 30 operates in an interlaced scan mode.
[0034] The gate lines G 1 , G 3 , . . . and G N-1 are scanned for display in a period 40 , which is completed in a period T odd in FIG. 7 . As shown in FIG. 3 , the timing controller 38 initially provides the starting pulse SP ODD . As the clock signal CLK switches, the gate driving circuit 32 l sequentially scan the gate lines G 1 , G 3 , . . . and G N-1 . Meanwhile, the gate driving circuit 32 r keeps the voltages on all of the even-number gate lines (the gate lines G 2 , G 4 , . . . and G N ) unchanged. The data driving circuit 36 may write appropriate data voltages into all of the pixels of the odd-number gate lines through the data lines D 1 , D 2 , . . . and D M . Each of the common electrode plates 37 is provided with the fixed common voltage V COM by the touch integrated circuit 39 at this point. Throughout the specification, an image formed by all of the pixels of the odd-number gate lines is referred to as an odd field; an image formed by of the pixels of the even-number gate lines is referred to as an even field. One odd field and one even field form one frame. In brief, the odd field is updated in the period 40 .
[0035] Touch detection and report are performed in a period 42 , which is completed in a period T tr1 in FIG. 7 . After the odd field is updated in the period 40 , touch detection and report may be performed using the common electrode plates 37 in FIG. 4 in the period 42 . For example, the voltages on the common electrode plates 37 are sequentially changed to measure the individual self capacitance changes of the common electrode plates 37 , so as to determine whether a touch point occurs and a position of the touch point. A first touch report is provided in the period 42 .
[0036] The gate lines G 2 , G 4 , . . . and G N a in a period 44 , which is completed in a period T even in FIG. 7 . As shown in FIG. 7 , the timing controller 38 initially provides the starting pulse SP EVEN . As the clock signal CLK switches, the gate driving circuit 32 r sequentially scans the gate lines G 2 , G 4 , . . . and G N . Meanwhile, the gate driving circuit 32 l keeps the voltages on all of the odd-number gate lines (G 1 , G 3 , . . . and G N-1 ) unchanged. The data driving circuit 36 may write appropriate data voltages into all of the pixels of the even-number gate lines through the data lines D 1 , D 2 , . . . and D M . Similarly, each of the common electrode plates 37 is provided with the constant common voltage V COM by the touch integrated circuit 39 . In brief, the even field is updated in the period 44 .
[0037] Touch detection and report are performed in a period 46 , which is completed in a period T tr2 in FIG. 7 . A second touch report is provided in the period 46 , and associated details may be identical or similar to those in the period 42 .
[0038] As shown in FIG. 6 , the odd field is updated in the period 40 , and the even field is updated in the period 44 . Thus, in one frame period T FRAME , one entire frame is updated.
[0039] The periods 40 , 42 , 44 and 46 are repeated in the periods 48 , 50 , 52 and 54 , respectively. As shown in FIG. 6 , the periods 40 , 42 , 44 and 46 are completed in one frame period T FRAME , and the periods 48 , 50 , 52 and 54 are completed in the next frame period T FRAME . In FIG. 6 , there are two touch reports in one frame period T FRAME . If the frame rate in FIG. 6 is 60 Hz, the touch report rate in FIG. 6 is 120 Hz, which is twice the frame rate.
[0040] The present invention does not limit the touch report rate to be twice the frame rate, and the touch report rate may also be three or more times the frame rate. For example, the gate lines G 1 , G 2 , G 3 . . . are divided into three groups—a first group including the gate lines G 1 , G 4 . . . , a second group including the gate lines G 2 , G 5 . . . , and a third group including the gate lines G 3 , G 6 . . . . A first field is an image displayed by the pixels in the first group, a second field is an image displayed by the pixels in the second group, and a third field is an image displayed by the pixels in the third group. The first, second and third fields together from one frame. FIG. 8 shows an operating timing implemented according to the present invention. In one frame period T FRAME , the first, second and third fields are sequentially updated. The touch detection and report are performed once each time a field is updated. Thus, if the frame rate in FIG. 8 is 60 Hz, the touch report rate in FIG. 6 is 180 Hz, which is three times the frame rate.
[0041] While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.
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A control method for a touch display device including a display panel is provided. The display panel includes multiple first gate lines and multiple second gate lines respectively corresponding to a first field and a second field of a frame, and multiple sensing electrodes for touch sensing. Within one single frame period, the control method includes: scanning the first gate lines to update the first field; controlling the sensing electrodes to perform touch sensing and providing a first touch report; scanning the second gates lines to update the second field; and controlling the sensing electrodes to perform touch sensing and providing a second touch report. At least one of the first gates lines is located between two of the second gate lines, and at least one of the second gate lines is located between two of the first gate lines.
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 11/744,386, filed May 4, 2007, and entitled “Means to Detect a Missing Pulse and Reduce the Associated PLL Phase Bump,” which is incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to electronic circuits, and more particularly to controlling the phase bump a phased locked loop.
[0003] A phase locked loop maintains a fixed relationship between the phase and frequency of the signal it receives and those of the signal it generates. FIG. 1 is a simplified block diagram of a conventional phase locked loop (PLL) 100 adapted to maintain a fixed relationship between the phase and frequency of signal CLK and signal REF. PLL 100 includes, among other components, phase detector 102 , charge pump 104 , loop filter 106 and voltage controlled oscillator (VCO) 108 . The extracted clock signal Clk is supplied at the output terminal of VCO 108 . The operation of PLL 10 is described further below.
[0004] Phase detector 102 receives signals REF and Clk, and in response, generates signals UP and DN that correspond to the difference between the phases of the signals REF and Clk. Charge pump 104 receives signals UP and DN and in response varies the current it supplies to node Vcntrl. Loop filter 106 stores the charge as a voltage, which is then delivered to VCO 108 .
[0005] If signal REF leads signal Clk in phase—indicating that the VCO is running relatively slowly—the duration of pulse signal UP increases, thereby causing charge pump 104 to increase its net output current I until VCO 108 achieves an oscillation frequency at which signal Clk is frequency-locked and phase-locked with signal REF. If, on the other hand, signal REF lags signal Clk in phase—indicating that the VCO is running relatively fast—the duration of pulse signal DN increases—thereby causing VCO 108 achieve an oscillation frequency at which signal Clk is frequency-locked and phase-locked with signal REF. Signal Clk is considered to be locked to signal REF if its frequency is within a predetermined frequency range of signal REF and the phase of signals CLK and REF are aligned. Signal Clk is considered to be out-of-lock with signal REF if its frequency is outside the predetermined frequency range of signal REF.
[0006] When the input reference clock to a PLL changes phase, the PLL must slew to the new phase. Such a condition may happen when, for example, the PLL switches from one reference clock to another clock with the same frequency but a different phase. Such a condition may also happen if the clock that the PLL switches to has a different frequency than the clock the PLL switches from. Furthermore, in some applications it is desirable to have the PLL output clock switch slowly, and not rapidly, to the new phase so as to enable other down-stream circuits to maintain proper operation.
[0007] When the input clock to a PLL misses a pulse or becomes inactive, the output of the Phase-Frequency detector 102 gets stuck in the down state until such time as the input clock becomes active again. Referring to FIGS. 1 and 2 concurrently, a clock signal, such as REF ideal , applied to a PLL ideally should not have missing pulses. However, in practical applications, a clock signal such as REF actual , actually received by a PLL includes missing pulses. The phase of the feedback signal CLK generated in response to clock signal REF actual begins to vary as a result of the missing pulses. These phase shifts Δφ 1 and Δφ 2 are shown in FIG. 2 relative to the ideal clock signal REF ideal .
[0008] When signal DN remains in a high state as a result of the missing pulses, the charge pump disposed in the PLL starts to remove charge from the loop filter. This causes signal Vcntrl generated by charge pump 104 to droop, in turn causing the VCO output phase to move away from its ideal value.
[0009] In accordance with the technique described in U.S. Pat. No. 6,393,596, missing pulses are detected by applying the reference clock to a filter and applying the filter's output to a comparator. Missing pulses cause the output voltage of the filter to shift. When the output voltage of the filter exceeds a threshold value, the comparator trips to indicate the detection of missing pulses. One drawback of this technique is that the filter reduced the sensitivity of the detection circuit, rendering it slow to respond. Accordingly, a number of missing pulses may be required before the detection.
[0010] In accordance with the technique described in U.S. Pat. No. 6,590,949, the reference clock signal is digitally compared against the feedback clock. However, detection is made only after a number of transitions of the reference clock signal have been missing.
BRIEF SUMMARY OF THE INVENTION
[0011] A phase/frequency locked loop (PLL) includes a circuit adapted to detect missing pulses of a reference clock applied to the PLL. The circuit includes, in part, first and second flip-flops, as well as a one-shot block. The first flip-flop has a data input terminal responsive to a voltage supply, and a clock terminal responsive to an inverse of a feedback clock. The second flip-flop has a data input terminal responsive to an output of the first flip-flop, and a clock terminal responsive to the inverse of the feedback clock. The one-shot block generates a pulse in response to a rising edge of the reference clock that is used to generate the feedback clock. The one-shot block generates an output signal applied to a reset terminal of the first flip-flop.
[0012] The circuit further includes, in part, third and fourth flip-flops. The third flip-flop has a data input terminal responsive to the voltage supply, and a clock terminal responsive to the feedback clock. The fourth flip-flop has a data input terminal responsive to an output of the third flip-flop and a clock terminal responsive to the feedback clock. The reset terminal of the third flip-flop receives the output signal of the one-shot block.
[0013] The circuit further includes, in part, fifth and sixth flip-flops as well as a second one-shot block. The fifth flip-flop has a data input terminal responsive to the voltage supply, and a clock terminal responsive to the inverse of feedback clock. The sixth flip-flop has a data input terminal responsive to an output of the fifth flip-flop, and a clock terminal responsive to the inverse of the feedback clock. The second one-shot block generates a pulse in response to a falling edge of the reference clock. The second one-shot block generates an output signal applied to a reset terminal of the fifth flip-flop.
[0014] The circuit further includes, in part, seventh and eight flip-flops. The seventh flip-flop has a data input terminal responsive to the voltage supply, and a clock terminal responsive to the feedback clock. The eight flip-flop has a data input terminal responsive to an output of the seventh flip-flop and a clock terminal responsive to the feedback clock. The reset terminal of the seventh flip-flop receives the output signal of the second one-shot block.
[0015] The circuit further includes, in part, first, second and third logic gates. The first logic gate performs a NOR operation on output signals of the second and fourth flip-flops. The second logic gate performs a NOR operation on output signals of the sixth and eight flip-flops. The third logic gate performs a NAND operation on output signals of the first and second logic gates. A cross-coupled NOR logic also disposed in the circuit is responsive to an output of the third logic gate. The reset terminals of the second, fourth, sixth and eight flip-flops are responsive to a reset signal to which said cross-coupled NOR logic is also responsive.
[0016] The PLL embodying the circuit further includes, in part, a phase/frequency detector responsive to a phase/frequency of each said feedback and the reference clock, a first pulse-width limiter adapted to generate a second pulse in response to a first output of the phase/frequency detector, a second pulse-width limiter adapted to generate a third pulse in response to a second output of the phase/frequency detector, a third pulse-width limiter adapted to generate a fourth pulse in response to an alarm signal; and a fourth logic gate performing an OR operation on said second and fourth pulses. The PLL further includes a charge pump responsive to the second pulse and the fourth logic gate; and an oscillator adapted to generate the feedback clock in response to the charge pump.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a block diagram of a PLL, as known in the prior art.
[0018] FIG. 2 is a timing diagram of a number of signals associated with the PLL of FIG. 1 .
[0019] FIG. 3 is a schematic diagram of a missing pulse detection circuit, in accordance with one embodiment of the present invention.
[0020] FIG. 4 is a timing diagram of a number of signals associated with circuit of FIG. 3 when the reference clock signal is initially in sync with the feedback clock signal but is subsequently stuck in a high level.
[0021] FIG. 5 is a timing diagram of a number of signals associated with circuit of FIG. 3 when the reference clock signal is initially in sync with the feedback clock signal but is subsequently stuck in a low level.
[0022] FIG. 6 is a timing diagram of a number of signals associated with circuit of FIG. 3 when the reference clock signal is initially 180 degrees out of phase with respect to the feedback clock signal but is subsequently stuck in a low level.
[0023] FIG. 7 is a timing diagram of a number of signals associated with circuit of FIG. 3 when the reference clock signal is initially 180 degrees out of phase with respect to the feedback clock signal but is subsequently stuck in a high level.
[0024] FIG. 8 is a block diagram of a PLL in which the circuit of FIG. 3 is disposed, in accordance with one embodiment of the present invention.
[0025] FIG. 9 is a timing diagram of a number of signals associated with the PLL of FIG. 8 , in accordance with one embodiment of the present invention.
[0026] FIG. 10 is a block diagram of a pulse-width limiter disposed in the PLL of FIG. 8 , in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0027] FIG. 3 is a schematic diagram of a missing pulse detection circuit 150 , in accordance with one embodiment of the present invention. When a missing pulse is detected by circuit 150 , the output signal Alarm of NOR gate 44 is set. Output signal ALARM is reset when signal ALARM_RESET applied to OR gate 12 is asserted.
[0028] One-shot block 10 generates a pulse on each rising edge of the reference clock signal REF and applies this pulse to OR gate 12 . Likewise, one-shot block 14 generates a pulse on each falling edge of the reference clock signal REF and applies this pulse to OR gate 16 . The output signal RISING of OR gate 12 is applied to the clear input terminals CLR of flip-flops 22 and 26 . The output signal FALLING of OR gate 16 is applied to the clear input terminals CLR of flip-flops 30 and 34 . Signal ALARM_RESET is applied to the CLR input terminals of flip-flops 24 , 28 , 32 and 36 .
[0029] The input clock terminals of flip-flops 22 and 24 receive clock signal FB 1 that is the inverse of feedback clock FEEDBACK_CLOCK supplied by the VCO disposed in a PLL embodying circuit 150 . The input clock terminals of flip-flops 30 and 32 receive clock signal FB 2 that is the inverse of clock FEEDBACK_CLOCK. Signal FEEDBACK_CLOCK is applied to the clock input terminals of flip-flops 26 , 28 , 34 and 36 . The output data of flip-flop 22 is applied to the input data of flip-flop 24 ; the output data of flip-flop 26 is applied to the input data of flip-flop 28 ; the output data of flip-flop 30 is applied to the input data of flip-flop 32 ; the output data of flip-flop 34 is applied to the input data of flip-flop 36 . The output data of flip-flops 24 and 28 are applied to NOR gate 38 . The output data of flip-flops 32 and 36 are applied to NOR gate 40 . The outputs of NOR gates 38 and 40 are applied to NAND gate 42 whose output is applied to cross-coupled NOR gates 44 , 46 . NOR gate 44 generates output signal ALARM, as described above. Flip-flops 22 , 24 , 26 , 28 , 30 , 32 , 34 and 36 are reset when their respective reset signal CLR is asserted.
[0030] FIG. 4 is a timing diagram of a number of signals associated with circuit 150 when the reference clock REF is initially in sync with the feedback clock FEEDBACK_CLOCK but is subsequently stuck in a low level. Referring concurrently to FIGS. 3 and 4 , with each rising edge of the reference clock signal REF, a RISING pulse is generated. Similarly, with each falling edge of the reference clock signal REF, a FALLING pulse is generated. Because the feedback clock signal generated by the VCO is always present, on each falling edge of signal FEEDBACK_CLOCK, a logic high is transferred from the input data terminal of flip-flop 22 to its output terminal. In other words, with each falling edge of signal FEEDBACK_CLOCK, signal V 1 A goes high. Because signal RISING is applied to the CLR terminal of flip-flop 22 , with each rising edge of signal RISING, VIA is reset to zero. For example, in response to falling edge 402 of signal FEEDBACK_CLOCK, signal V 1 A goes high 404 , and in response to rising edge 406 of signal RISING, signal VIA goes low 408 . In response to edge 410 of signal FEEDBACK_CLOCK, signal V 1 A goes high 412 . On the next falling edge 414 of signal FEEDBACK_CLOCK, the high level of signal V 1 A causes signal V 1 B to go high 416 , which in turn causes NOR gate 38 , NAND gate 42 and NOR gates 44 and 46 to set signal ALARM to a high level 450 to indicate detection of the missing pulse on the reference clock signal CLK. In response to the next rising edge 418 of the reference clock signal REF, signal RISING goes high 420 , thereby causing signal V 1 A to go low 422 . On the next falling edge 424 of signal FEEDBACK_CLOCK, the low level of signal V 1 A causes signal V 1 B to go low 426 .
[0031] FIG. 5 is a timing diagram of a number of signals associated with circuit 150 when the reference clock REF is initially in sync with the feedback clock FEEDBACK_CLOCK but is subsequently stuck in a high level. Referring concurrently to FIGS. 3 and 5 , with each rising edge of the reference clock signal REF, a RISING pulse is generated. Similarly, with each falling edge of the reference clock signal REF, a FALLING pulse is generated. Because the feedback clock signal generated by the VCO is always present, on each falling edge of signal FEEDBACK_CLOCK, a logic high is transferred from the input data terminal of flip-flop 34 to its output terminal. In other words, with each falling edge of signal FEEDBACK_CLOCK, signal V 4 A goes high. Because signal FALLING is applied to the CLR terminal of flip-flop 34 , with each rising edge of signal FALLING, signal V 4 A is reset to zero. For example, in response to rising edge 502 of signal FEEDBACK_CLOCK, signal V 4 A goes high 504 , and in response to rising edge 506 of signal FALLING, signal V 4 A goes low 508 . In response to edge 510 of signal FEEDBACK_CLOCK, signal V 4 A goes high 512 . On the next rising edge 514 of signal FEEDBACK_CLOCK, the high level of signal V 4 A causes signal V 4 B to go high 516 , which in turn causes NOR gate 40 , NAND gate 42 and NOR gates 44 and 46 to set signal ALARM to a high level 550 to indicate detection of the missing pulse on the reference clock signal CLK. In response to the next falling edge 518 of the reference clock signal REF, signal FALLING goes high 520 , thereby causing signal V 4 A to go low 522 . On the next rising edge 524 of signal FEEDBACK_CLOCK, the low level of signal V 4 A causes signal V 4 B to go low 526 .
[0032] FIG. 6 is a timing diagram of a number of signals associated with circuit 150 when the reference clock REF is initially 180 degrees out of phase with respect to the feedback clock FEEDBACK_CLOCK but is subsequently stuck in a low level. Referring concurrently to FIGS. 3 and 6 , with each rising edge of the reference clock signal REF, a RISING pulse is generated. Similarly, with each falling edge of the reference clock signal REF, a FALLING pulse is generated. Because the feedback clock signal generated by the VCO is always present, on each rising edge of signal FEEDBACK_CLOCK, a logic high is transferred from the input data terminal of flip-flop 26 to its output terminal. In other words, with each rising edge of signal FEEDBACK_CLOCK, signal V 2 A goes high. Because signal RISING is applied to the CLR terminal of flip-flop 26 , with each rising edge of signal RISING, signal V 2 A is reset to zero. For example, in response to rising edge 602 of signal FEEDBACK_CLOCK, signal V 2 A goes high 604 , and in response to rising edge 606 of signal RISING, signal V 2 A goes low 608 . In response to edge 610 of signal FEEDBACK_CLOCK, signal V 2 A goes high 612 . On the next rising edge 614 of signal FEEDBACK_CLOCK, the high level of signal V 2 A causes signal V 2 B to go high 616 , which in turn causes NOR gate 38 , NAND gate 42 and NOR gates 44 and 46 to set signal ALARM to a high level 650 to indicate detection of the missing pulse on the reference clock signal CLK. In response to the next rising edge 618 of the reference clock signal REF, signal RISING goes high 620 , thereby causing signal V 2 A to go low 622 . On the next rising edge 624 of signal FEEDBACK_CLOCK, the low level of signal V 2 A causes signal V 2 B to go low 626 .
[0033] FIG. 7 is a timing diagram of a number of signals associated with circuit 150 when the reference clock REF is initially 180 degrees out of phase with respect to the feedback clock FEEDBACK_CLOCK but is subsequently stuck in a high level. Referring concurrently to FIGS. 3 and 7 , with each rising edge of the reference clock signal REF, a RISING pulse is generated. Similarly, with each falling edge of the reference clock signal REF, a FALLING pulse is generated. Because the feedback clock signal generated by the VCO is always present, on each falling edge of signal FEEDBACK_CLOCK, a logic high is transferred from the input data terminal of flip-flop 30 to its output terminal. In other words, with each falling edge of signal FEEDBACK_CLOCK, signal V 3 A goes high. Because signal FALLING is applied to the CLR terminal of flip-flop 30 , with each rising edge of signal FALLING, signal V 3 A is reset to zero. For example, in response to falling edge 702 of signal FEEDBACK_CLOCK, signal V 3 A goes high 704 , and in response to rising edge 706 of signal FALLING, signal V 3 A goes low 708 . In response to edge 710 of signal FEEDBACK_CLOCK, signal V 3 A goes high 712 . On the next falling edge 714 of signal FEEDBACK_CLOCK, the high level of signal V 3 A causes signal V 3 B to go high 716 , which in turn causes NOR gate 40 , NAND gate 42 and NOR gates 44 and 46 to set signal ALARM to a high level 750 to indicate detection of the missing pulse on the reference clock signal CLK. In response to the next falling edge 718 of the reference clock signal REF, signal FALLING goes high 720 , thereby causing signal V 3 A to go low 722 . On the next falling edge 724 of signal FEEDBACK_CLOCK, the low level of signal V 3 A causes signal V 3 B to go low 726 . Referring to FIGS. 4-7 , it is seen that signal ALARM is set half a clock cycle after a missing pulse occurs on signal REF.
[0034] FIG. 8 is a schematic diagram of a PLL 200 , in accordance with one embodiment of the present invention. PLL 200 is shown as including a phase/frequency detector 202 , missing pulse detection circuit 150 (see FIG. 3 ), pulse-width limiters 204 , 206 , 208 and OR gate 210 . Pulse-width limiter 206 limits the width of signal DN received from phase/frequency detector 202 to generate signal DN_X. Pulse-width limiter 204 limits the width of signal UP_L received from phase/frequency detector 202 to generate signal UP_L. Pulse-width limiter 208 limits the width of signal ALARM received from circuit 150 shown in FIG. 3 to generate signal ALARM_L.
[0035] FIG. 9 is a timing diagram of a number of signal associated with PLL 200 . Reference clock signal REF is shown as having missing pulses. Because transitions 900 and 902 of signals FEEDBACK_CLOCK and REF are aligned, phase/frequency detector 202 generates both UP and DN pulses 904 , 906 . Accordingly, pulses 908 and 910 also appear on signals UP_X and DN_X. Similarly, because transitions 930 and 932 of signals CLK and REF are aligned, phase/frequency detector 102 generates both UP and DN pulses 934 , 936 , in response to which, pulses 938 and 940 appear on signals UP_X and DN_X.
[0036] Since there is no transition on signal REF during the next two cycles of signal CLK, signal DN goes high 952 in response to transition 950 of signal CLK. Accordingly, pulse width limiter 206 generates pulse 954 on signal DN_X. Because reference clock signal REF was in sync with feedback clock signal FEEDBACK_CLOCK before being stuck at a low level, on the next falling edge 952 of signal FEEDBACK_CLOCK, pulse-width detection circuit 150 causes signal ALARM to go high 956 , as was described in detail above with references to FIGS. 3 and 4 . In response, pulse width limiter 208 generates a pulse 956 on signal ALARM_L, which in turn causes a pulse 958 to appear on signal UP_X. Pulse 958 of signal UP_X reduces the phase bump generated as a result of pulse 954 on signal DN_X.
[0037] The above embodiments of the present invention are illustrative and not limiting. Various alternatives and equivalents are possible. The invention is not limited by the type of pulse-width limiting, slew detection, etc. The invention is not limited by the number of current sources or current sinks. The invention is not limited by the type of integrated circuit in which the present disclosure may be disposed. Nor is the disclosure limited to any specific type of process technology, e.g., CMOS, Bipolar, or BICMOS that may be used to manufacture the present disclosure. Other additions, subtractions or modifications are obvious in view of the present disclosure and are intended to fall within the scope of the appended claims.
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A phase/frequency locked loop (PLL) includes circuitry adapted to detect missing pulses of a reference clock and to control the phase bump of the PLL. The circuitry includes, in part, first and second flip-flops, as well as a one-shot block. The first flip-flop has a data input terminal responsive to a voltage supply, and a clock terminal responsive to an inverse of feedback clock. The second flip-flop has a data input terminal responsive to an output of the first flip-flop, and a clock terminal responsive to the inverse of the feedback clock. The one-shot block generates a pulse in response to a rising edge of the reference clock that is used to generate the feedback clock. The one-shot block generates an output signal applied to a reset terminal of the first flip-flop.
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This application claims the benefit of U.S. Provisional Application No. 60/687,183, filed Jun. 3, 2005, the entire disclosure of which is hereby incorporated by reference.
FIELD OF THE INVENTION
The invention relates to exchange trade matching systems and methods. More particularly, the invention relates to implementation of a request for cross functionality (RFC) into the trading environment.
DESCRIPTION OF THE RELATED ART
In existing exchanges, when a user wants to place an order in a continuous two sided market, their bids or offers are submitted and an attempt to match the users order is conducted. The bids and offers are placed in the book and are matched in real time on a price-time priority basis.
If there is no match or the customer does not want to take an existing bid/offer, as the price is not appropriate, in a conventional trading system the user would enter the price they want for the product into an order book and wait for a match to occur. However, in an illiquid market that order may rest in the order book for a long time and may never match. Therefore, there is a need in the art for a more robust and efficient trade matching system and method.
SUMMARY
Aspects of the present invention overcome problems and limitations of the prior art by providing request for cross functionality. The request for cross functionality integrates the benefits of the dual bid-ask continuous trading market model with the price and quantity trade matching systems and methods.
In an aspect of the invention, a request for quote may be submitted to determine the liquidity of a particular instrument of interest to a broker and/or customer. In response to the request for quote, orders or quotes may be submitted by market participants. The broker may receive an initiating order from a customer. If no match can be found for the customer's order, the broker may contact various market makers in order to request their best price for the other side of the customer's order without revealing the full information about the quantity, price, and buying/selling side of the product. Once a market maker has been found a request for cross is initiated and the marketplace is informed that a match will occur for the product. Additional market participants upon being informed that a match will occur may place new orders for the product within a specified time frame enabling the customer to complete his/her order.
Details of the invention are set forth in the accompanying drawings and the description below. Other features and advantages of the invention will be apparent from the description, drawings, and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may take physical form in certain parts and steps, embodiments of which will be described in detail in the following description and illustrated in the accompanying drawings that form a part hereof, wherein:
FIG. 1 illustrates a computer network system that may be used to implement aspects of the present invention;
FIG. 2 illustrates a method of Requesting a Crossing of a trade in a trade matching engine in accordance with an aspect of the invention;
FIG. 3 further illustrates a method of Requesting a Crossing of a trade in a trade matching engine in accordance with an aspect of the invention;
FIGS. 4-6 show the type of data that may be included in an order book in one illustrative example of the invention in accordance with an aspect of the invention;
FIGS. 7-11 show the type of data that may be included in an order book in a second illustrative example of the invention in accordance with an aspect of the invention; and
FIGS. 12-16 show the type of data that may be included in an order book in a third illustrative example of the invention in accordance with an aspect of the invention.
DETAILED DESCRIPTION
In order to clarify the description, definitions of several terms are provided. The terms are exemplary and are not intended to be limiting of the scope of the invention.
1) Broker—An intermediary who provides a transaction service between market makers and customers and/or between two customers. 2) Broker Match Guarantee (BMG)—A trade engine guaranteed match event occurring at the conclusion of the Pre-Cross period between parties specified by the Broker. 2A) Better Price Match (BPM)—A trade engine guaranteed match event occurring when the RFC price is better than the order book prices at the time the RFC is received and the order book prices are not through the RFC price at the conclusion of the Pre-Cross period between parties specified by the Broker. 3) Call Around—Broker method of contacting market makers and determining their willingness to commit to take the opposite side of an Initiating Order. 4) Customer—A user who utilizes a Broker to transact orders on their behalf. 5) Initiating Order—Customer side order. 6) Market Maker—A user who provides liquidity in response to a RFQ or RFC. 7) Pre-Cross Period—Time period related to a first of two RFC match process cycles. 8) Remaining 1 —The residual quantity remaining after the BMG match event has completed. 9) Request for Cross (RFC)—A market alert mechanism that indicates that a match will occur for an instrument. 10) Request for Quote (RFQ)—A market alert mechanism initiated by a Broker that asks the marketplace to post liquidity for an instrument. 11) Cross Period—Time period related to the second of two RFC match process cycles.
Aspects of the present invention are preferably implemented with or used in conjunction with computer devices and computer networks. An exemplary trading network environment for implementing trading systems and methods is shown in FIG. 1 . An exchange computer system 100 receives orders and transmits market data related to orders and trades to users. Exchange computer system 100 may be implemented with one or more mainframe, desktop or other computers. A user database 102 includes information identifying traders and other users of exchange computer system 100 . Data may include user names and passwords.
An account data module 104 may process account information that may be used during trades. A match engine module or trade matching engine 106 is included to match bid and offer prices. Match engine module 106 may be implemented with software that executes one or more algorithms for matching bids and offers. A trade database 108 may be included to store information identifying trades and descriptions of trades. In particular, a trade database may store information identifying the time that a trade took place and the contract price. An order books module 110 may be included to compute or otherwise determine current bid and offer prices. A market data module 112 may be included to collect market data and prepare the data for transmission to users. A risk management module 134 may be included to compute and determine a user's risk utilization in relation to the user's defined risk thresholds. An order processor module 136 may be included to decompose delta based and bulk order types for processing by order book module 110 and trade matching engine 106 .
The trading network environment shown in FIG. 1 includes computer devices 114 , 116 , 118 , 120 , and 122 . Each computer device includes a central processor that controls the overall operation of the computer and a system bus that connects the central processor to one or more conventional components, such as a network card or modem. Each computer device may also include a variety of interface units and drives for reading and writing data or files. Depending on the type of computer device, a user can interact with the computer with a keyboard, pointing device, microphone, pen device or other input device.
Computer device 114 is shown directly connected to exchange computer system 100 . Exchange computer system 100 and computer device 114 may be connected via a T 1 line, a common local area network (LAN) or other mechanism for connecting computer devices. Computer device 114 is shown connected to a radio 132 . The user of radio 132 may be a trader or exchange employee. The radio user may transmit orders or other information to a user of computer device 114 . The user of computer device 114 may then transmit the trade or other information to exchange computer system 100 .
Computer devices 116 and 118 are coupled to a LAN 124 . LAN 124 may have one or more of the well-known LAN topologies and may use a variety of different protocols, such as Ethernet. Computers 116 and 118 may communicate with each other and other computers and devices connected to LAN 124 . Computers and other devices may be connected to LAN 124 via twisted pair wires, coaxial cable, fiber optics or other media. Alternatively, a wireless personal digital assistant device (PDA) 122 may communicate with LAN 124 or the Internet 126 via radio waves. PDA 122 may also communicate with exchange computer system 100 via a conventional wireless hub 128 . As used herein, a PDA includes mobile telephones and other wireless devices that communicate with a network via radio waves.
FIG. 1 also shows LAN 124 connected to the Internet 126 . LAN 124 may include a router to connect LAN 124 to the Internet 126 . Computer device 120 is shown connected directly to the Internet 126 . The connection may be via a modem, DSL line, satellite dish or any other device for connecting a computer device to the Internet.
One or more market makers 130 may maintain a market by providing constant bid and offer prices for a derivative or security to exchange computer system 100 . Exchange computer system 100 may also exchange information with other trade engines, such as trade engine 138 . One skilled in the art will appreciate that numerous additional computers and systems may be coupled to exchange computer system 100 . Such computers and systems may include clearing, regulatory and fee systems.
The operations of computer devices and systems shown in FIG. 1 may be controlled by computer-executable instructions stored on computer-readable medium. For example, computer device 116 may include computer-executable instructions for receiving order information from a user and transmitting that order information to exchange computer system 100 . In another example, computer device 118 may include computer-executable instructions for receiving market data from exchange computer system 100 and displaying that information to a user.
Of course, numerous additional servers, computers, handheld devices, personal digital assistants, telephones and other devices may also be connected to exchange computer system 100 . Moreover, one skilled in the art will appreciate that the topology shown in FIG. 1 is merely an example and that the components shown in FIG. 1 may be connected by numerous alternative topologies.
In an aspect of the invention, a user wants to place an order in a continuous two sided market (bids and offers are in the book and matched in real time on a price-time priority basis). However, the user does not want to take an existing bid/offer that is resting in the book, as the price, for example, may not be satisfactory to the user. Moreover, the prices may or may not be posted for a given instrument such as the Eurodollar option or Eurodollar future.
Referring to FIGS. 2 and 3 , a method of requesting a cross in a trade matching engine 106 is illustrated in accordance with an aspect of the invention. In a first step 202 , a customer may contact a broker to express an interest for a various trade.
In response to the customer inquiry, the broker in a step 204 may submit a request for quote (RFQ). The RFQ may ask the marketplace to post liquidity for a particular instrument of interest to the broker and customer. In response to the RFQ, orders or quotes may be submitted by other market participants as illustrated in step 206 . In step 208 , the broker may receive an initiating order from a customer. The initiating order may include the price and quantity requested by the customer.
In step 210 , the price and quantity requested by the customer may be compared to orders that have been entered into an order book. If the price and quantity in the order book fully meet the customer's initiating order, then in step 212 the order book's bid or offer is manually swept by the broker to the extent of the initiating order. As the customer's order has been completed the process ends at step 213 . Other non-RFC related matching may occur on the order book during the entire RFC process.
However, if the price and quantity entered in the order book do not fully meet the customer's initiating order then, the broker may call around in step 214 to find an opposite side to the customer's initiating order. For example, a customer's broker, in order to find a match, may contact various market makers (MMs) and request their best price for the other side of the customer's order without revealing the full order information (maybe only the quantity and the type of product). Communications between broker and customer may be accomplished through various media such as e-mail, instant messaging, telephone, and/or other communication devices or methods. Those skilled in the art will realize that other forms of communication may be utilized in order to find an opposite side to the customer's initiating order.
If one or more market makers agree to take the other side of the order at the price and quantity desired by the customer, the following steps may occur. In step 216 , the broker initiates a two sided request for cross (RFC) message. The two sided RFC message may include additional information such as account numbers for the buy side and the sell side. Other information such as order type instructions to be applied after the RFC has expired may also be included. Such instructions may include FAK (Fill and Kill) and/or limit session instructions. In addition, the matching engine or match engine module 106 may terminate the RFC request (step 213 ), if at anytime either side of the order is fully matched. For example, the termination of the RFC may occur when the order is fully matched during such times as at the end of the Pre-Cross period, anytime during the Cross period, or anytime at the end of the Cross period.
When the trade matching engine or match engine module 106 accepts the RFC, then in step 218 a Pre-Cross period begins. The two sided RFC message may be sent out on the market data feed indicating to all market participants that a request for cross (RFC) in a particular product has occurred. The price and quantity may not be revealed to the market participants, only the existence of the RFC. The informed market participants may know that that the RFC was issued. This may allow additional market participants to submit orders to the order book. The trade matching engine 106 may inform the trading community of the RFC at many different stages of the RFC process such as when the RFC is accepted by the trade matching engine 106 or when a particular time period has expired. For instance, trade matching engine 106 may broadcast messages to market participants after a first time period and a second time period have expired.
In step 220 , orders and quotes may be submitted in response to the RFC during the Pre-Cross period. The Pre-Cross period may include a time period such as 15 seconds before proceeding to allow new orders to be sent to the system. Those skilled in the art will realize that the time period of 15 seconds is exemplary and that a longer or shorter time period may be utilized. In addition, the time period may be different for various different products such as Eurodollar options and Eurodollar futures. In step 222 of FIG. 3 , the Pre-Cross period expires after the selected time period. A message may be generated to acknowledge the expiration of the Pre-Cross period. A flag may also be utilized to indicate the Pre-Cross period expiration.
Next, in step 224 price and quantity may be compared to orders in the order book to see if price and quantity match either side of the RFC. If price and quantity match either side of the RFC, then orders may be automatically matched by the trade matching engine ( 106 ) to the extent of either of the RFC's order sides. The use of regular match algorithms by the trade matching engine ( 106 ) may apply.
In step 227 , the trade matching engine 106 may check to determine whether either side of the order was completely filled. If either side of the RFC order was completely filled then the RFC may be ended (step 213 ) and the remaining side of the order may be subject to FAK or limit/session instructions as dictated in the original RFC submission. Moreover, market data and clearing messages may be generated in step 228 . If only a portion of either side of the RFC order was matched then the remaining portion advances to step 234 .
If price and quantity do not match either side of the RFC (step 224 ), then in step 223 it may be determined if a Better Price Match (BPM) allocation will be applied. A BPM allocation may occur if the RFC price is better than the existing order book bid and ask prices at the time the RFC is received by the matching engine (i.e. the beginning of the Pre-Cross period) and the order book prices are not through the RFC price at the conclusion of the Pre-Cross period. The Better Price Match (BPM) allocation occurs for twenty-five percent (step 225 ) of the RFC order quantity. Those skilled in the art will realize that the allocation percentage is exemplary and may be higher or lower in various different aspects of the invention. In addition, in an aspect of the invention, the BPM allocation may not be changed during a particular trading session. In other aspects of the invention, the BPM allocation may be defined to two decimal places, may be rounded down, and may not be greater than 100 percent. Market data and clearing messages may be generated.
Next, in step 234 , a Broker Match Guarantee (BMG) allocation may occur for sixty (60) percent of the remainder of the order (customer order amount less matched above). Those skilled in the art will realize that the allocation percentage is exemplary and may be higher or lower in various different aspects of the invention. In addition, in an aspect of the invention, the BMG may not be changed during a particular trading session. In other aspects of the invention, the BMG may be defined to two decimal places, may be rounded down, and may not be greater than 100 percent. The market maker allocation may then be matched against the customer's order. Even if there are no resting orders to be matched with either side of the RFC, the BMG may still be applied to the RFC. The opposing sides of the BMG's allocation percentage may be the customer side (initiator side) and the market maker side.
In step 236 , the customer's order and market maker's order for the residual amount may be automatically displayed in the order book for both bid and offer sides (Remaining 1 ). The Remaining 1 order sides may be displayed for a maximum of a Cross period. Both sides of the orders (customers or market makers) may be available for immediate matching from outside orders during the Cross period. For example, Cross period may be a time period such as 15 seconds. Those skilled in the art will realize that that time period of 15 seconds is exemplary and that a longer or shorter time period may be utilized. The use of regular match algorithms by trade matching engine 106 may apply. A message may be generated to acknowledge the expiration of the Cross period. A flag may also be utilized to indicate Cross period expiration.
In step 239 , the trade matching engine 106 may determine if one side of the RFC sides has been completely filled. If one side of the RFC sides has been completely filled then the RFC may be terminated at step 213 . Market data and clearing messages may be generated. However, if both sides of the RFC remain then the process advances to step 240 .
In step 240 , if Cross period time expires and the Remaining 1 quantities are equal, then Remaining 1 order sides may be automatically matched on trade matching engine 106 with one another (step 242 ). Moreover, in step 228 market data and clearing messages may be generated. However, if Cross period time expires and the Remaining 1 quantities are unequal (step 244 ), then any Remaining 1 equal quantities may be automatically matched by the trade matching engine 106 (step 248 ) and any residual Remaining 1 order quantity may be subject to FAK or limit/session instructions (step 246 ) as dictated in the original RFC submission. In another aspect of the invention, a RFC may only be valid for the market session in which they were entered. If an unscheduled market pause or close occurs, the RFC may be terminated with the session market change and may not transfer to the next market cycle open. Moreover, in step 228 , market data and clearing messages may be generated.
A RFC may be cancelled at any time during the above process. A minimum RFC order may also be established for various products. Orders already matched may be left matched and no subsequent steps may be executed. Also, during the Pre-Cross period other trades based on normal orders may match at any price (above or below the RFC price). Furthermore, the RFC orders may be put last in the time order for price-time priority matching purposes. That is an order entered later in time may match against a RFC order before the other side of the RFC order.
The following examples are meant to help further illustrate various aspects of the invention. For instance, listed below are illustrative examples of when a Best Price Match (BPM) allocation may occur. Those skilled in the art will realize that the following scenarios are meant to provide illustrative examples of BPM allocation in various embodiments and are not meant to limiting. As stated above, if the RFC price is better than the existing order book bid and offer prices at the time the RFC is received by the matching engine (i.e. the beginning of the Pre-Cross period) and the order book prices are not through the RFC price at the conclusion of the Pre-Cross period, then a Better Price Match (BPM) allocation occurs. In an illustrative example, the order book may contain a bid price of $4.00 and an offer price of $6.00. A RFC may be entered with a price of $5.00 for a quantity of 5000 contracts. At the end of the Pre-Cross period, the market may have adjusted to the point where the order book contains a bid price of $5.00 and an offer price of $6.00. A BPM allocation is applied in the above exemplary embodiment as the RFC price is better than the order book bid and offer prices upon receipt by the trade matching engine 106 or exchange computer system 100 , and the order book bid or offers prices are not through the RFC price at the conclusion of the Pre-Cross period. After the BPM allocation, the trade matching engine 106 or exchange computer system 100 may match the market's $5.00 bid against the RFC offer. Trade matching engine 106 or exchange computer system 100 may apply the Broker Match Guarantee (BMG) percentage if there is remaining RFC quantity on both sides.
In another illustrative example, the order book may contain a bid price of $5.00 and an offer price of $6.00. A RFC may be entered for a price of $5.00 with a quantity of 5000 contracts. At the end of the Pre-Cross period, the market may not change and the order book may still include a bid price of $5.00 and an offer price of $6.00. Because the RFC price is not better than the markets bid and offer price at the time of receipt by trade matching engine 106 , BPM allocation is not applied. The trade matching engine 106 or exchange computer system 100 may match the market's $5.00 bid against the RFC offer. Trade matching engine 106 or exchange computer system 100 may apply BMG if there is remaining RFC quantity on both sides.
In a third illustrative example, the order book may contain a bid price of $4.00 and an offer price of $6.00. A RFC may be entered with a price of $5.00 for a quantity of 5000 contracts. At the end of the Pre-Cross period, the market may include a bid price of $3.00 and an offer price of $4.00. In this example, the order book offer price at $4.00 is through the RFC bid price of $5.00. Therefore, BPM allocation is not applied. The market's $4.00 offer may be matched against the RFC bid and the RFC bid receives the price improvement. Trade matching engine 106 or exchange computer system 100 may apply BMG if there is remaining RFC quantity on both sides.
In a fourth illustrative example, the order book may contain a bid price of $5.00 and an offer price of $6.00. A RFC may be entered with a price of $5.00 for a quantity of 5000 contracts. At the end of the Pre-Cross period, the market may include a bid price of $4.00 and an offer price of $6.00. Because the RFC price is not better than the bid and offer prices at the time the RFC was received into the order book, BPM allocation is not applied.
In a fifth illustrative example, the order book may contain a bid price of $4.00 and an offer price of $6.00. A RFC may be entered with price of $5.00 for a quantity of 5000 contracts. At the end of the Pre-Cross period, the market may include a bid price of $4.00 and an offer price of $6.00. Because the RFC price is better than the order book prices when the RFC was received by the trading system and the order book prices are not through the RFC price at the end of the Pre-Cross period, BPM allocation is applied.
In a sixth illustrative example, the order book may not contain a bid or an offer. A RFC may be entered with price of $5.00 for a quantity of 5000 contracts. At the end of the Pre-Cross period, the market may have not expressed any interest. Because the RFC price is a better price (and only price), BPM allocation is applied at the end of the Pre-Cross period.
The following examples are described in conjunction with FIGS. 2 and 3 . In a first exemplary scenario, a RFC is executed at a price between the bid and offer price found in an order book. In particular, FIG. 4 illustrates entries into an order book 401 . The order book 401 may be layout such that bids 402 are placed in the left hand side of order book 401 and offers 404 are placed on the right hand side of order book 401 . As described above in FIGS. 2 and 3 , a customer may contact a broker to express an interest for various trades in step 202 . In response to the customer inquiry, the broker in a step 204 may submit a request for quote (RFQ). The RFQ may ask marketplace participants to post the liquidity for a particular instrument of interest to the broker and customer. In response to the RFQ, orders or quotes may be submitted by market participants as illustrated in step 206 . For example in response to a broker's RFQ, a response such as a bid price of $2.00 dollars ( 405 ) for a quantity of 2000 contracts ( 406 ) and an offer price of $3.00 dollars ( 407 ) for a quantity of 5000 contracts ( 408 ) may be received in response to the RFQ for a particular instrument These price and quantities may be placed in order book 401 as illustrated in FIG. 4 .
In step 208 , the broker may receive an initiating order from a customer. The initiating order may include the price and quantity requested by the customer. For example, the broker may receive an initiating order to sell 10,000 contracts at a price of $2.50 dollars per contract.
Next in step 210 , a price and quantity requested by the customer may be compared to orders that have been entered into order book 401 . If the price and quantity in the order book 401 fully meet the customer's initiating order, then in step 212 the order book's bid or offer may be manually swept by the broker to the extent of the initiating order. As the customer's order has been completed the process ends at step 213 .
However, if the price and quantity entered in the order book 401 do not fully meet the customer's initiating order then, the broker may call around in step 214 to find an opposite side to customer's initiating order. For example, the broker may find a customer wanting to buy 10,000 contracts at a price of $2.50 per contract. In order to find a match, the broker may contact various market makers (MMs) and request their best price for the other side of the customer's order without revealing the full order information (maybe only the quantity and the type of product). Communications between broker and customer may be accomplished through various media such as e-mail, instant messaging, telephone, and/or other communication devices or methods. Those skilled in the art will realize that other forms of communication may be utilized in order to find an opposite side to the customer's initiating order. Based on this order, the broker submits the RFC at $2.50 per contract. The request as described in step 216 may be in the form of a two sided request for cross (RFC) message initiated by the broker.
The market trade matching engine 106 may accept the RFC and in step 218 a Pre-Cross period starts. The two sided RFC message may be sent out on the market data feed indicating to all market participants that a request for cross (RFC) in a particular product has occurred. The price and quantity may not be revealed to the market participants, only the existence of the RFC. The informed market participants may know that that the RFC was issued. This may allow additional market participants to submit new orders to the order book 401 .
In step 220 , orders and quotes may be submitted in response to the RFC during the Pre-Cross period. The Pre-Cross period may include a time period such as 15 seconds before proceeding to allow new orders to be sent to the system. After expiration of the Pre-Cross period, the market's response may still be a bid price of $2.00 dollars ( 405 ) for a quantity of 2000 contracts ( 406 ) and an offer price of $3.00 dollars ( 407 ) for a quantity of 5000 contracts ( 408 ) as shown in FIG. 4 .
In step 222 of FIG. 3 , the Pre-Cross period expires after the selected time period. Price and quantity may be compared to orders in the order book 401 in step 224 to determine if price and quantity match either side of the RFC. In this example, the price and the quantities do not match either side of the RFC.
Next, in step 223 , if the RFC price is better than the existing order book bid and ask prices at the time the RFC is received by the matching engine (i.e. the beginning of the Pre-Cross period) and the order book prices are not through the RFC price at the conclusion of the Pre-Cross period, then a Better Price Match (BPM) allocation occurs for twenty-five percent (step 225 ) of the RFC order quantity. Those skilled in the art will realize that the allocation percentage is exemplary and may be higher or lower in various different aspects of the invention. Therefore, as the criterion in step 223 has been satisfied in step 225 , a Better Price match occurs for twenty-five percent of the order. Those skilled in the art will realize that the allocation percentage is exemplary and may be higher or lower in various different aspects of the invention. In this example, twenty-five (25) percent of the 10,000 contracts is equivalent to 2,500 contracts at a price of $2.50 per contract.
Next, in step 234 , a Broker Match Guarantee (BMG) allocation occurs for sixty (60) percent of the remainder of the order (customer order amount less matched above). Those skilled in the art will realize that the allocation percentage is exemplary and may be higher or lower in various different aspects of the invention. In this example, sixty (60) percent of the remaining 7,500 contracts is equivalent to 4,500 contracts at a price of $2.50 per contract.
In step 236 , the customer's order and market maker's order for the residual amount may be automatically displayed in the order book for both bid and offer sides (Remaining 1 ). The Remaining 1 order sides may be displayed for a maximum of Cross period. Both sides of the orders (customers or market makers) may be available for immediate matching from outside orders during the Cross period. For example, Cross period may be a time period such as 15 seconds. Those skilled in the art will realize that the 15 second time period is exemplary and that a longer or shorter time period may be utilized. The order book 401 may appear as illustrated in FIG. 5 wherein the Remaining 1 3000 contracts ( 412 ) for a price of $2.50 ( 414 ) per contract may be displayed. During the Cross period, the market may have the opportunity to buy and/or sell the remaining contracts. The use of regular match algorithms by the trade matching engine 106 may apply.
Next, in step 239 the trade matching engine 106 may determine if one side of the RFC sides has been completely filled. If one side of the RFC sides has been completely filled then the RFC may be terminated at step 213 . Market data and clearing messages may be generated. However, if both sides of the RFC remain then the process advances to step 240 . In this exemplary example, both sides of the RFC remain.
Next in step 240 and FIG. 6 , if Cross period time expires and the Remaining 1 quantities are equal, and then Remaining 1 order sides may automatically match on the trade matching engine 106 with one another (step 242 ). For example, the trade matching engine 106 crosses the RFC balance of 3000 contracts ( 412 ) at a price of $2.50 ( 414 ) per contract. Moreover, in step 228 market data and clearing messages may be generated. Because Cross period time has expired and Remaining 1 quantities are unequal (step 244 ), the residual Remaining 1 quantities of 2000 contracts ( 406 ) at $2.00 ( 405 ) and 5000 contracts ( 408 ) at $3.00 ( 407 ) are subject to FAK or limit/session instructions as dictated in the original RFC submission.
In a second exemplary scenario, an RFC may partially match the best bid in an order book. In particular, FIG. 7 illustrates entries into an order book 701 . The order book 701 may be layout such that bids 702 are placed in the left hand side of order book 701 and offers 704 are placed on the right hand side of order book 701 . As described above in FIGS. 2 and 3 , a customer may contact a broker to express an interest for various trades in step 202 . In response to the customer inquiry, the broker in a step 204 may submit a request for quote (RFQ). The RFQ may ask marketplace participants to post the liquidity for a particular instrument of interest to the broker and customer. In response to the RFQ, orders or quotes may be submitted by market participants as illustrated in step 206 . For example in response to a broker's RFQ, a response such as a bid price of $2.00 dollars ( 705 ) for a quantity of 2000 contracts ( 706 ) and an offer price of $3.00 dollars ( 707 ) for a quantity of 5000 contracts ( 708 ) may be received in response to the RFQ for a particular instrument These prices and quantities may be placed in order book 701 as illustrated in FIG. 7 .
In step 208 , the broker may receive an initiating order from a customer. The initiating order may include the price and quantity requested by the customer. For example, the broker may receive an initiating order to sell 10,000 contracts at a price of $2.00 dollars per contract.
Next in step 210 , a price and quantity requested by the customer may be compared to orders that have been entered into order book 701 . If the price and quantity in the order book 701 fully meet the customer's initiating order, then in step 212 the order book's bid or offer may be manually swept by the broker to the extent of the initiating order. As the customer's order has been completed, the process ends at step 213 .
However, if the price and quantity entered in order book 701 do not fully meet the customer's initiating order then, the broker may call around in step 214 to find an opposite side to customer's initiating order. For example, the broker may find a market maker wanting to buy 10,000 contracts at a price of $2.00 per contract. Based on this order the broker requests to cross the trade (RFC) at $2.00 per contract. The request as described in step 216 may be in the form of a two sided request for cross (RFC) message initiated by the broker.
The trade matching engine 106 may accept the RFC and in step 218 a Pre-Cross period starts. The two sided RFC message may be sent out on the market data feed indicating to all market participants that a request for cross (RFC) in a particular product has occurred. The price and quantity may not be revealed to the market participants, only the existence of the RFC. The informed market participants may know that that the RFC was issued. This may allow additional market participants to submit new orders to the order book 701 .
In step 220 , orders and quotes may be submitted in response to the RFC during the Pre-Cross period. The Pre-Cross period may include a time period such as 15 seconds before proceeding to allow new orders to be sent to the system. In step 222 of FIG. 3 , Pre-Cross period expires after the selected time period. After expiration of the Pre-Cross period, the market's response may be as shown in FIG. 8 . In FIG. 8 , a bid price of $2.00 dollars ( 712 ) for a quantity of 2500 contracts ( 714 ) and an offer price of $3.00 dollars ( 707 ) for a quantity of 5000 contracts ( 708 ) may be received from the marketplace.
Next, in step 224 price and quantity may be compared to orders in order book 701 to see if price and quantity match either side of the RFC. In this example, step 224 is satisfied because the new bid order of $2.00 dollars ( 712 ) for a quantity of 2500 contracts ( 714 ) matches the RFC offer price but the quantity is insufficient. The engine automatically fills the order for 2500 contracts ( 714 ) at $2.00 dollars ( 712 ) per contract. FIG. 9 illustrates order book 701 after the engine fills the order.
In step 227 , the trade matching engine 106 may check to determine whether either side of the order was completely filled. If either side of the RFC order was completely filled then the RFC may be ended (step 213 ) and the remaining side of the order may be subject to FAK or limit/session instructions as dictated in the original RFC submission. Moreover, market data and clearing messages may be generated in step 228 . If only a portion of either side of the RFC order was matched then the remaining portion advances to step 234 to determine if a Broker Match Guarantee allocation may be applied.
If price and quantity do not match either side of the RFC (step 224 ), then in step 223 , it may be determined if a Better Price Match (BPM) allocation will be applied. In this exemplary embodiment, a BPM allocation does not occur.
Next, in step 234 , a Broker Match Guarantee (BMG) allocation occurs for sixty (60) percent of the remainder of the order (customer order amount less matched above). Those skilled in the art will realize that the allocation percentage is exemplary and may be higher or lower in various different aspects of the invention. In this example, sixty (60) percent of the remaining 7,500 contracts is equivalent to 4,500 contracts at a price of $2.00 per contract. In step 228 , market data and clearing messages may be generated for the guaranteed BMG allocation percentage.
In step 236 , the customer's order and market maker's order for the residual amount may be automatically displayed in the order book 701 for both bid and offer sides (Remaining 1 ). The Remaining 1 order sides may be displayed for a maximum of Cross period. Both sides of the orders (customers or market makers) may be available for immediate matching from outside orders during the Cross period. For example, Cross period may be a time period such as 15 seconds. Those skilled in the art will realize that that time period of 15 seconds is exemplary and that a longer or shorter time period may be utilized. The order book 701 may appear as illustrated in FIG. 10 wherein the Remaining 1 5500 bid balance contracts ( 722 ) for a price of $2.00 ( 724 ) per contract and the 3000 offers contracts ( 726 ) for a price of $2.00 ( 728 ) may be displayed. During the Cross period, the market may have the opportunity to buy and/or sell the remaining contracts. The use of regular match algorithms by the trade matching engine 106 may apply. In the example, the market does not buy or sell at a price of $2.00 per contract on either side of the market.
Next, in step 239 the trade matching engine 106 may determine if one side of the RFC sides has been completely filled. If one side of the RFC sides has been completely filled then the RFC may be terminated at step 213 . Market data and clearing messages may be generated. However, if both sides of the RFC remain then the process advances to step 240 . In this exemplary example, both sides of the RFC remain.
Next in step 240 and FIG. 6 , if Cross period time expires and the Remaining 1 quantities are equal, and then Remaining 1 order sides may automatically match on the trade matching engine 106 with one another. For example, the engine crosses the RFC balance of 3000 contracts ( 726 ) at a price of $2.00 ( 728 ) per contract. Moreover, in step 228 market data and clearing messages may be generated. Because Cross period time has expired and Remaining 1 quantities are unequal (step 244 ), the residual Remaining 1 quantities of 2500 contracts (not shown) at $2.00 and 5000 contracts ( 708 ) at $3.00 ( 707 ) are subject to FAK or limit/session instructions as dictated in the original RFC submission. In this example, the remaining 2,500 contracts on the bid are cancelled as the broker gave FAK instructions. The order book 701 after the transactions may still show the initial 5,000 offer contracts ( 708 ) at $3.00 ( 707 ) per contract as illustrated in FIG. 11 .
In a third exemplary scenario, one side of an RFC may get a better fill price due to an intervening order price. In particular, FIG. 12 illustrates entries into an order book 1201 . The order book 1201 may be layout such that bids 1202 are placed in the left hand side of order book 1201 and offers 1204 are placed on the right hand side of order book 1201 . As described above in FIGS. 2 and 3 , a customer may contact a broker to express an interest for various trades in step 202 . In response to the customer inquiry, the broker in step 204 may submit a request for quote (RFQ). The RFQ may ask marketplace participants to post the liquidity for a particular instrument of interest to the broker and customer. In response to the RFQ, orders or quotes may be submitted by market participants as illustrated in step 206 . For example in response to a broker's RFQ, a response such as a bid price of $2.00 dollars ( 1205 ) for a quantity of 2000 contracts ( 1206 ) and an offer price of $2.50 dollars ( 1207 ) for a quantity of 5000 contracts ( 1208 ) may be received in response to the RFQ for a particular instrument These prices and quantities may be placed in order book 1201 as illustrated in FIG. 12 .
In step 208 , the broker may receive an initiating order from a customer. The initiating order may include price and quantity requested by the customer. For example, the broker may receive an initiating order to sell 10,000 contracts at a price of $2.00 dollars per contract.
Next in step 210 , a price and quantity requested by the customer may be compared to orders that have been entered into order book 1201 . If the price and quantity in the order book 1201 fully meet the customer's initiating order, then in step 212 the order book's bid or offer may be manually swept by the broker to the extent of the initiating order. As the customer's order has been completed the process ends at step 213 .
However, if the price and quantity entered in the order book 1201 do not fully meet the customer's initiating order then, the broker may call around in step 214 to find an opposite side to customer's initiating order. For example, the broker may find a customer wanting to buy 10,000 contracts at a price of $2.00 per contract. Based on this order, the broker requests to cross the trade (RFC) at $2.00 per contract. The request as described in step 216 may be in the form of a two sided request for cross (RFC) message initiated by the broker.
The trade matching engine 106 may accept the RFC and in step 218 a Pre-Cross period starts. The two sided RFC message may be sent out on the market data feed indicating to all market participants that a request for cross (RFC) in a particular product has occurred. The price and quantity may not be revealed to the market participants, only the existence of the RFC. The informed market participants may know that that the RFC was issued. This may allow additional market participants to submit new orders to the order book 1201 .
In step 220 , orders and quotes may be submitted in response to the RFC during the Pre-Cross period. The Pre-Cross period may include a time period such as 15 seconds before proceeding to allow new orders to be sent to the system. In step 222 of FIG. 3 , Pre-Cross period expires after the selected time period. After expiration of the Pre-Cross period, the market's response may be as shown in FIG. 13 . In FIG. 13 , a bid price of $1.00 dollar ( 1312 ) for a quantity of 20,000 ( 1314 ) contracts and an offer price of $1.50 dollars ( 1316 ) for a quantity of 8000 contracts ( 1318 ) may be received from the marketplace.
In step 222 of FIG. 3 , the Pre-Cross period expires after the selected time period. In step 224 , price and quantity may be compared to orders in order book 1201 to determine if price and quantity match either side of the RFC. In this example, trade matching engine 106 may match 8,000 contracts on the RFC market maker buy side. This matching may result in a price of $1.50 per contract which means that the RFC market maker buy side gets a better price for the 8,000 contracts. In other words, the market maker intended to buy at $2.00 per contract but the order was filed at $1.50 per contract.
In step 227 , the trade matching engine 106 may check to determine whether either side of the order was completely filled. If either side of the RFC order was completely filled then the RFC may be ended (step 213 ) and the remaining side of the order may be subject to FAK or limit/session instructions as dictated in the original RFC submission. Moreover, market data and clearing messages may be generated in step 228 . If only a portion of either side of the RFC order was matched then the remaining portion advances to step 234 .
Because there was insufficient quantity to meet one side of the RFC, the Broker Guarantee Match (BMG) allocation occurs in step 234 . The BMG may occur for sixty (60) percent of the remainder of the order (customer order amount less matched above). Those skilled in the art will realize that the allocation percentage is exemplary and may be higher or lower in various different aspects of the invention.
In this example, sixty (60) percent of the remaining 2,000 contracts is equivalent to 1,200 contracts at a price of $2.00 per contract. After the BMG, the market maker may have 800 contracts ( 1402 ) at $2.00 ( 1403 ) left and the RFC initiator side has 8,800 contracts ( 1404 ) at $2.00 ( 1406 ) remaining as illustrated in FIG. 14 . In step 228 , market data and clearing messages may be generated for the guaranteed BMG allocation percentage.
Next, in step 236 , the user's order or market maker's order for the residual amount may be automatically displayed in the order book 1201 for both bid and offer sides (Remaining 1 ). The Remaining 1 order sides may be displayed for a maximum of Cross period. For example, Cross period may be a time period such as 15 seconds. Those skilled in the art will realize that that time period of 15 seconds is exemplary and that a longer or shorter time period may be utilized.
During the Cross period, the market may have the opportunity to buy and/or sell the remaining contracts. In this example, the offer is manually matched by another user for 5,000 contracts as shown in FIG. 15 . In FIG. 15 , the offer side 1204 has only 3,800 contracts ( 1502 ) at a price of $2.00 ( 1504 ) per contract. The use of regular match algorithms by trade matching engine 106 may apply. Moreover, in step 228 , market data and clearing messages may be generated. In the example, the market does not buy or sell at a price of $2.00 per contract on either side of the market.
Next, in step 239 the trade matching engine 106 may determine if one side of the RFC sides has been completely filled. If one side of the RFC sides has been completely filled then the RFC may be terminated at step 213 . Market data and clearing messages may be generated. However, if both sides of the RFC remain then the process advances to step 240 . In this exemplary example, both sides of the RFC remain.
Next in step 240 and FIG. 14 , if Cross period time expires and the Remaining 1 quantities are equal then Remaining 1 order sides may automatically match on the trade matching engine with one another. In this third example, the Remaining 1 quantities are not equal so the trade matching engine 106 moves to step 244 . When the Cross period time expires, 800 contracts ( 1402 ) at a price of $2.00 ( 1403 ) are matched by the engine. The remaining 3000 contracts ( 1602 ) at a price of $2.00 ( 1604 ) per contract remains on order book 1201 as the order were specified with limit/session orders.
The present invention has been described herein with reference to specific exemplary embodiments thereof. It will be apparent to those skilled in the art that a person understanding this invention may conceive of changes or other embodiments or variations, which utilize the principles of this invention without departing from the broader spirit and scope of the invention as set forth in the appended exemplary aspects of the invention. All are considered within the sphere, spirit, and scope of the invention.
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Systems and methods are provided to fulfill customer trading orders in an illiquid two sided market. Request for cross functionality may be implemented in a trading environment using a trading engine for the matching of trades involving financial instruments. Request for cross functionally integrates the benefits of a dual bid-ask continuous trading market model with the price and quantity trade matching systems and methods.
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FIELD OF THE INVENTION
The present invention relates to a refrigerator; and, more particularly, to a refrigerator having a cooled-air passageway defined by a sunken portion of a liner and a cover plate covering the sunken portion, resulting in the cooled-air passageway being formed opposite to a thermal insulation layer about the liner.
DESCRIPTION OF THE PRIOR ART
In general, a conventional household refrigerator has a storage compartments, e.g., a freezer compartment or a fresh food compartment in which foods is stored in a cooled-air environment, an evaporator for generating the cooled-air, and passageways through which the cooled-air is supplied from the evaporator to the storage compartments.
There is shown in FIG. 1 one example of the conventional household refrigerators. The refrigerator 1 has an outer liner 7 positioned outmost from a storage compartment, a thermal insulation layer 2 inside the outer liner 7, an inner liner 5 inside the thermal insulation layer 2, a lateral outlet port 4 vertically arranged on a lateral surface 8 of the storage compartment, through which the cooled-air is introduced into the storage compartment and a corner outlet port 6 vertically arranged on a corner defined by a rear surface 9 and the lateral surface 8, at an angle of 45° with the rear surface 9. The thermal insulation layer 2 is made of urethane foam. Positioned on a rear of the inner liner 5 near the corner outlet port 6 and the lateral outlet port 4 is a tubular wall 3a defining a passageway for the cooled-air, with the inner liner 5, which communicates between a space of an evaporator(not shown) and the storage compartment.
The conventional refrigerator constructed in this manner, however, has a shortcoming in that it is difficult form the passageway therewithin. That is, since the tubular wall is installed at the rear of the inner liner before the introduction of the urethane to form the thermal insulation layer, the tubular wall may deform or get damaged, resulting in the urethane foams trespassing the passageway, which may, in turn, entail a reinstallation of the passageway or even an additional foaming process of the urethane.
SUMMARY OF THE INVENTION
It is, therefore, a primary object of the invention to provide a refrigerator having a cooled-air passageway defined with a sunken portion of a liner and a cover plate covering the sunken portion, thereby allowing the cooled-air passageway to exist on an opposite side to a thermal insulation layer about the liner.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and features of the instant invention will become apparent from the following description of preferred embodiments taken in conjunction with the accompanying drawings, in which:
FIG. 1 illustrates a sectional perspective view of a prior art refrigerator;
FIG. 2 shows an exploded perspective view of a refrigerator in accordance with the present invention;
FIG. 3 represents a planar sectional view of the inventive refrigerator;
FIG. 4 presents an enlarged planar sectional view of a vertical cooled-air passageway in the inventive refrigerator;
FIG. 5 sets forth a top planar view of a horizontal cover plate employed in the inventive refrigerator;
FIG. 6 depicts a frontal elevational view of the horizontal cover plate employed in the inventive refrigerator;
FIG. 7 discloses a side sectional view of the horizontal cover plate in FIG. 6, taken along a line VII--VII; and
FIG. 8 gives a sectional view of the horizontal cover plate and a lateral sunken portion assembled into the horizontal cover plate.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 2, the inventive refrigerator is provided with a storage compartment defined with a door(not shown), two lateral surfaces 60 (only one is shown) and a rear surface 50, all being provided by a liner 10, the liner 10 being an innermost thin member of the refrigerator 100. Formed outside the liner 10 is a thermal insulation layer 20 made of urethane foams. The storage compartment, for example, may be a fresh food compartment or a freezer compartment. A cooled-air generated by an evaporator is supplied into the storage compartment through an external cooled-air passageway(not shown) which communicates with a corner passageway formed by a corner sunken portion 12 and a vertical cover plate 20.
The corner sunken portion 12 is a concavely sunken from the rear surface 50; and the vertical cover plate 20 is combined with the corner sunken portion 12, forming a main cooled-air passageway for the storage compartment. The vertical cover plate 20 is provided with a plurality of outlet ports 22 through which the cooled-air is introduced into the storage compartment.
A lateral sunken portion 11 is formed with the lateral surface 60. The lateral sunken portion 11 is a concavely sunken from the lateral surface 60 which meets the corner sunken portion 12. A horizontal cover plate 30 is combined with the lateral sunken portion 11 to form a lateral cooled-air passageway for the storage compartment. The lateral and the corner cooled-air passageways communicates with each other. The horizontal cover plate 30 is provided with a plurality of outlet ports 32 through which the cooled-air within the lateral cooled-air passageway is introduced into the storage compartment.
Referring to FIG. 3, the corner sunken portion 12 and the vertical cover plate 20 which form the corner cooled-air passageway are combined with each other via a plurality of hooks 26 formed with the vertical cover plate 20 and hook receiving holes 14 formed through the corner sunken portion 12. The hooks 26 are formed on both ends of the vertical cover plate 20, respectively. The corner cooled-air passageway is arranged at an angle of 45° with the rear surface to direct the cooled-air toward a center of the storage compartment.
As shown in FIG. 4, according to one aspect of the present invention, a pair of slanted surfaces 28 are formed with both ends of the vertical cover plate 20, respectively. Further, corners 16 and 17 of the corner sunken portion 12 coming into contact with the slanted surfaces 28, respectively, are rounded, allowing the rounded corner 16 and the slanted surface 28 corresponding thereto to meet at one point along an entire length of the vertical cover plate 20, when the vertical cover plate 20 is combined with the corner sunken portion 12.
By this configuration, the contact between the vertical cover plate 20 and the corner sunken portion 12 can be well maintained, even if there may occur variations of shape of the liner 10 after the introduction of the urethane foams to form the thermal insulation layer 2. For example, if the position of the liner 10 of the corner sunken portion 12 becomes moved to the right as indicated with a broken line after the introduction of the urethane, the vertical cover plate 20 can be mounted on the corner sunken portion 12, being translated downwardly, as shown in FIG. 4. Even in this case, a close contact between the vertical cover plate 20 and the corner sunken portion 12 can be obtained, with the contact point moving to other place on the slanted surface 28 from a contact point in which the slanted surface 28 and the rounded corner 17 are to be met if there's no position change of the liner 10. In order to avoid an interference between the vertical cover plate 20 and the lateral surface 60, a corner lateral surface 13 of the corner sunken portion 12 is differently leveled from the lateral surface 60 by a predetermined distance.
In addition, a thermal insulation material 24 is applied on an inner surface of the vertical cover plate 20 to prevent dew from forming on the vertical cover plate 20 due to a temperature difference between an inside and an outside of the vertical cover plate 20.
In FIGS. 5 through 7, there is shown the horizontal cover plate 30 providing the lateral cooled-air passageway. As shown in FIG. 5, the horizontal cover plate 30 is an elongated member with a predetermined width. The horizontal cover plate 30 has a connection portion 34 which covers the level difference between the lateral surface 60 and the corner lateral surface 13. As shown in FIG. 6, the horizontal cover plate 30 further has a plurality of outlet ports 32 formed therethrough. As shown in FIGS. 5 and 7, the horizontal cover plate 30 has a plurality of hooks 36 and a thermal insulation material 35 on an inner surface thereof.
The horizontal cover plate 30 constructed in this manner, is combined with the lateral sunken portion 11 through which a plurality of hook receiving holes 42 are formed as shown in FIG. 8. The lateral sunken portion 11 has a cross-section of a step-shaped configuration which has a tapered section 43 for preventing the liner 10 of the step-shaped cross-section from being deflected.
Although the invention has been shown and described with respect to the preferred embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.
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A refrigerator has a storage compartment defined with two lateral walls and a rear wall. The walls has a liner at its innermost surface and a urethane foam outside the liner. The refrigerator is provided with a passageway defined with a sunken portion of the liner which is depressed toward a urethane foam and a cover plate installed within a storage compartment to cover the sunken portion and having an outlet port through which a cooled-air from an evaporator is introduced into the storage compartment.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a division of application Ser. No. 257,997, filed Apr. 27, 1981, which is a continuation of application Ser. No. 674,502, filed Apr. 7, 1976, now abandoned, which was a continuation of application Ser. No. 595,738, filed July 14, 1975, now U.S. Pat. No. 3,993,237, which was a continuation of application Ser. No. 445,807, filed Feb. 25, 1974, now abandoned, which was a division of application Ser. No. 157,433, filed June 28, 1971, now U.S. Pat. No. 3,819,468.
This application briefly describes, but does not claim, a method and apparatus for welding which is more fully described and claimed in copending Application Ser. No. 157,432, filed on 6/28/71, in the names of the inventors Robert A. Sauder and Gary B. Kendrick and entitled "Method and Apparatus for Stud Welding."
FIELD OF THE INVENTION
The present invention relates to a method and apparatus for insulating the interior of a high temperature furnace and more particularly to a ceramic fiber mat constituting the hot face of the insulation and wherein substantially all of the fibers in the fiber mat lie in planes which are generally perpendicular to the various walls of the furnace.
THE PRIOR ART
The problems involved in insulating the interior of a high temperature furnace or, stated differently, the walls and ceiling of such a furnace are well known. Historically, the interiors of high temperature furnaces have been lined with various types of bricks capable of withstanding these high temperatures. When the brick lining wears out, however, it is an arduous and time-consuming task to replace the old brick with a new brick lining. On the other hand, efforts have been made to insulate the interior of a furnace where the interior or hot face of the insulation includes or consists of ceramic fiber material. Ceramic fiber material, as referred to herein, is generally available in the form of a ceramic fiber blanket which is customarily manufactured in a manner similar to the conventional paper-making process. As such, the fibers which constitute the blanket, (as is also the case in connection with paper) are oriented in planes which are generally parallel to the longitudinal direction of formation of the blanket or sheet. When, as proposed in the past, lengths of ceramic fiber blanket are placed against a furnace wall or overlying an intermediate insulating member which, in turn, would be attached to the furnace wall, the fibers will then be lying in planes generally parallel to the furnace wall. Also, it is believed that a majority of these fibers will be lying in a direction which would tend to be colinear with the direction of formation of the blanket itself, although a considerable number of fibers are still in a more or less random disposition in these planes. Nevertheless, where the fibers are disposed in planes which are parallel to the furnace wall, there is a tendency for the fiber blanket material to produce cracks which result from heat shrinkage.
With certain types of insulation it is recognized that high temperature problems sometimes involve melting, oxidation and other types of deterioration of the insulating medium. As far as ceramic fiber insulation is concerned, the high temperature problems are generally cracking, delamination (peeling off of the surface layers), and devitrification, all of which are believed to be interrelated. At the lower temperatures of the recommended range of the present invention, namely, 1600° to 2800° F., devitrification will take place relatively slowly, whereas at the higher end of the range, devitrification will take place quite rapidly, followed, in short order, by cracking and/or delamination.
In retrospect, the prior art broadly discloses the feature of re-orienting fiber insulation, but only in connection with low temperature insulation. For example, Di Maio et al U.S. Pat. No. 2,949,593 and Slayter U.S. Pat. No. 3,012,923 both show the cutting of strips of fibrous material from a sheet or mat of the same, arranging the strips in a side-by-side relation to provide an end fiber exposure, compressing the strips and, while still compressed, applying an adhesive backing sheet of paper or cloth to one side edge only of the resulting compressed block; thereafter when the forces of compression are removed the resulting block will tend to curl around the adhesive sheet so as to form a suitable insulating body for pipe or the like. However, the resulting insulation is necessarily low-temperature insulation because the pipe is in direct contact with the heating or cooling medium which it carries; the insulation is used on the external surface of the body or pipe to be insulated; the sole purpose in arranging the strips in an end or edgewise exposure of the fibers is to permit compression of the strips so that, after one side edge is secured in place by means of the backing strip, advantage can be taken of the relatively greater expansibility along the unsecured edge.
SUMMARY OF THE INVENTION
The present invention involves the use of a ceramic fiber mat which can be applied either directly to the interior of a high-temperature furnace or to an intermediate insulating member which, in turn, is attached to one of the furnace walls. The term "wall" should be construed as covering any side wall or ceiling, removable or fixed, the area surrounding any access opening and any other surface on the interior of the high-temperature chamber where insulation is required or desired. The term "furnace" should be construed as covering any high-temperature chamber, oven, heater, kiln or duct with the understanding that the insulation is always internal and always "high-temperature", namely capable of operating at temperatures in excess of 1600° F.
The ceramic fiber mat is preferably made up of strips which are cut transversely from a length of ceramic fiber blanketing which is commercially available. The strips are cut from the fiber blanket in widths that represent the linear distance from the cold face to the hot face of the insulating fiber mat. The strips which are cut from the blanket are placed on edge and laid lengthwise adjacent each other with a sufficient number of strips being employed to provide a mat of the desired width. Naturally, the thickness of the fiber blanket from which the strips are cut will determine the number of strips required to construct the mat. The strips can be fastened together by wires, or by ceramic cement or mortar which is preferably employed in the region of the cold fact of the mat. The mat can be applied to the furnace wall or to an intermediate member by means of a stud welding method or by ceramic cement, mortar, or the like.
As disclosed herein, the present invention has particular application for the internal insulation of furnace walls of high temperature furnaces. For the purposes of the present invention, "high temperature" will mean temperatures in excess of 1600° F. and, preferably, in the range of 1600° F. to 2800° F. The ceramic fiber strips referred to herein are cut from a ceramic fiber blanket which is commercially available from several different manufacturers; these blankets are manufactured under the trademarks or tradenames "Kaowool" (Babcock & Wilcox), "Fibre-Frax" (Carborundum Co.), "Lo-Con" (Carborundum Co.), and "Cero-Felt" (Johns Manville Corp.). Most of these ceramic fiber blankets have an indicated maximum operating temperature of about 2300° F. The end or edge fiber exposure provided by the present invention not only provides an improved insulation up to the maximum indicated operating temperatures suggested by the manufacturers, but because devitrification and its deleterious effects are largely eliminated, also permits operation up to about 2800° F.
By arranging the fibers in an end or edgewise exposure; that is, where the fibers are oriented in planes generally perpendicular to the wall of the furnace, devitrification is not necessarily avoided but its undesirable side effects are minimized or eliminated because devitrification takes place at the ends of the fibers rather than along the lengths thereof; thus cracking and delamination are essentially avoided by the present invention even up to a temperature of 2800° F. which is above the recommended maximum temperature specifications imposed upon the fiber blankets by the manufacturers.
The present invention also provides an insulation which will maintain the outside (cold face) of the furnace within an acceptable range. It is recognized that the minimum external temperature will be dependent upon a number of different factors including, but not limited to, the type, thickness and strength of the outside furnace wall; ambient temperature conditions outside the furnace wall. The use of the present invention, however, will provide an outside temperature varying between 200° and 350° F. which is considered to be an acceptable range, the temperature being measured in still air at 83° F.
Another advantage which accrues from the use of the fiber blanket (or strips thereof) in the end or edge exposure of the fibers is that the resulting mat has a certain resiliency in a direction parallel to the insulated face. Thus, where metallic fasteners are employed to attach the mat or composite block to the interior wall of the furnace or oven by "burying" or imbedding the fastener in the insulating member, this natural resiliency of the material will tend to keep the ends of the fastening elements completely covered at all times; this is true even if a tool is inserted in or through the fiber material to engage the metallic fastener for turning or welding purposes; after the tool has been withdrawn the natural resiliency of the fibrous material, as presently oriented, will cause the material to spring back and completely cover the outer end of the metallic fastening member.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary plan view of an insulating mat made from strips of a ceramic fiber blanket;
FIG. 2 is a fragmentary side elevation of the ceramic fiber mat shown in FIG. 1;
FIG. 3 is an end elevation of the ceramic fiber mat shown in FIG. 1;
FIG. 4 is a plan view of another embodiment of a ceramic fiber mat made in accordance with the present invention;
FIG. 5 is a side elevation of the ceramic fiber mat shown in FIG. 4 with certain internal connecting members shown in dotted lines and further showing the association of the resulting insulating member with a furnace wall;
FIG. 6 is an end elevation of the ceramic fiber mat shown in FIG. 5;
FIG. 7 is a view similar to FIG. 6 showing a method of stud welding of the resulting insulating member to a furnace wall;
FIG. 8 is an enlarged and fragmentary detail view, with certain parts in cross-section, of the stud, nut and associated structure involved;
FIG. 9 is a view similar to the lower portion of FIG. 8 showing the relationship of the various parts following the welding operation;
FIG. 10 is an enlargement, on a slightly larger scale, of the retaining ring shown in FIG. 8;
FIG. 11 shows a parquet-type arrangement of insulating members on a furnace wall;
FIG. 12 shows an enlargement of insulating members on a furnace wall with spaces between adjacent members being filled with separate insulating elements;
FIG. 13 shows one embodiment of a separate insulating element to be inserted between adjacent insulating members;
FIG. 14 is another embodiment of a separate insulating element to be inserted between adjacent insulating members; and
FIG. 15 is still another embodiment of a separate insulating element to be inserted between adjacent insulating members.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings in detail, FIG. 1 shows a portion of the outer surface (hot face) of an insulating mat, generally designated by the reference character 20, composed of a plurality of strips 22 which are cut transversely from a ceramic fiber blanket (not shown). As indicated heretofore, these ceramic fiber blankets are generally provided in widths of several feet, of thicknesses generally ranging from one-sixteenth of an inch to three inches and of almost any desired length; the manufacturer generally rolls up the blankets lengthwise so that, when supplied, these blankets are in the form of rolls whose diameters are dependent upon the length of material in the roll. When the strips 22 are cut from the fiber blanket they are cut in a direction of the thickness perpendicular to the width and length so that the lowermost strip 22 shown in FIG. 1 has a dimension T which represents the thickness of the fiber blanket from which the strips 22 are cut.
The strips 22, after they are cut from the fiber blanket, are placed on edge adjacent each other until the desired width of mat is obtained as shown in FIG. 1. Obviously, the number of strips required will depend upon the thickness T of the fiber blanket from which the strips are cut. If a fiber blanket could be provided of thickness twice that of T, then only one half of the number of strips shown in FIG. 1 would be required. Furthermore, if it were possible to provide a fiber blanket having a thickness equal to the width of the resulting block or mat therefor, then only one such strip would be employed in connection with each insulating block.
The strips 22 are held together by any convenient means; as best shown in FIGS. 1 to 3, the strips 22 are held together by means of a plurality of stainless steel wires 24 which run transverse to the strips approximately one-half inch from and parallel to the cold face 26 of the mat. The ends of the wires 24 are bent at right angles as shown so as to be retained in position. Various methods and means can be used in conjunction with these wires 24 to attach the mat 20 to a sheet or block of backing type insulation 28 (see FIGS. 5 and 6); for example, a plurality of hairpin-type devices 30 can be placed over the wires 24 at various positions along their length so as to project down below the cold face 26 of the mat 20. Actually, these pins 30 will be driven into the block of backing type insulation 28 and, preferably, these hairpin devices 30 will be of the self-clenching type when they are urged against a hard surface as will appear hereinafter.
Although the mat shown in FIGS. 1 and 2 (and the resulting insulating member comprised thereof) is represented as having a width of approximately one foot and a length of possibly several feet, the preferred shape is shown in FIGS. 4 to 7. The resulting insulating member shown in these figures would have a nominal twelve inch by twelve inch face size and a 2300° F. temperature rating. The actual face size will be 121/4"×121/4", the additional 1/4" insuring fullness in the installed insulation while providing a net twelve inch by twelve inch coverage. Intermediate strips 22' and the outer strips 34 (later to be described) are cut to their respective sizes from one inch thick ceramic fiber blanket. The block of insulation 28 is mineral block insulation which, in this case, is cut to a size two inches thick, ten inches wide and twelve inches long. Since the outer strips 34 overlie the longitudinal side edges of the block 28, these strips would be two inches longer (in the vertical direction as they appear in FIG. 7) than the intermediate strips 22'. It might also be mentioned that a hole 36 is drilled in the center of the block 28 so as to receive a stud (later to be described).
Parts 34 and 22' are now laid side by side to form the hot face and are secured together by means of the stainless steel wires 24 which are bent ninety degrees at the ends to hold them in place. As shown in FIGS. 4 and 5, two such wires 24 are provided for the insulating member shown in these figures, although additional number of wires could be provided if desired.
The next step in the assembly of the insulating member involves the installation of the stud which will now be described. The stud comprises a central shank 38 having nut 40 threadedly mounted at the upper end thereof. A washer 42 is provided on the shank 38 immediately below the nut 40. When installed, the washer 42 will rest against the upper surface of the block 28. The lower end of the shank 38 is provided with a stud tip 44 of relatively smaller cross sectional area. Also mounted on the lower end of the shank 38 are a ring retainer 46 received in the groove 48 and a ring-shaped ceramic arc shield 50 which is secured to the ring 46 by cement or in any other suitable manner. The purposes of the foregoing elements will be described hereinafter in greater detail.
At any event, after the stud (with associated elements attached) is inserted into the hole 36 in the manner described above, the prior assembly of parts 22', 34 and 24 are placed over the block 28 with the lower parts of the side strips 34 overlying the two longitudinal side edges of the block 28. Four hairpin-type stainless steel fasteners 30 (two for each wire 24) are now inserted into the seams between the strips 22' so as to engage the wires 24. These fasteners 30 are driven through and clenched against the back surface of the block 28. By providing a hard surface, preferably steel, below the block 28 when the fasteners 30 are inserted, the lower ends of these fasteners will clench towards each other as shown in FIG. 5. When the tool (not shown) for inserting the fasteners 30 is withdrawn from the seams, the strips 22' will return to their original position without leaving any gap or aperture because of the inherent resiliency of these strips.
The resulting insulation member, now complete, is ready for installation against a furnace wall 32 by means of a stud welding process which is more fully described and claimed in copending application "Method and Apparatus for Stud Welding" referred to above. The method and apparatus for stud welding (as described in the aforementioned copending application) forms no part of the present invention but is described briefly hereinafter merely to show one manner of attachment of the insulating member 20' to a furnace wall. A stud welding gun 52 is inserted into the central seam between the middle strips 22' until the lower end of the gun engages the nut 40 of the stud. The stud gun is triggered and current flows into the shank 38 and into the tip 44. The tip 44, because of its relatively small cross sectional area burns away and thus starts an arc. The stud shank 38 does not itself move at first because it is supported by the self-locking ring retainer 46 which is retained in the groove 48 as indicated heretofore. As best shown in FIG. 10, the ring retainer 46 is provided with a plurality of radial fingers 54 which project into the recess 48 to hold the ring 46 in position. As the welding operation continues, the intense heat of the arc burns away the fingers 54, thus allowing the stud shank 38 to plunge into the molten metal formed by the arc. At this point, the weld is completed and the gun can be withdrawn. It should be mentioned, however, that the ring retainer 46 and the fingers 54 thereon are carefully sized so that the fingers will burn away, melt, or soften in approximately two tenths of a second, or within whatever period of time is deemed appropriate, all as set forth more fully in the aforementioned copending application.
Now, it may be desirable to tighten the nut 40 on the shank 38. This can be done by merely rotating the gun about the vertical axis of the shank. It might be mentioned that the lower end of the gun (or extension thereof, if desired) is provided with a hexagonal opening corresponding to the size of the nut 40 and of sufficient depth to accommodate for the upper end of the shank 38 after the nut is tightened thereon. Thus the gun 52 serves a secondary function as a wrench for the nut. When the stud gun is withdrawn, the resiliency of the ceramic fiber strips will cause the strips to return to their original position thus concealing and protecting the studs from the severe heat in the furnace.
Returning now to further consideration of FIGS. 4 and 5, it should be noted that the end strips 34 of the insulating member 20' are preferably provided with a plurality of one inch deep cuts 56 spaced approximately one inch apart from each other so as to relieve possible shrinkage stresses on parts 34 only.
As shown in FIG. 11, it may be desirable to arrange the blocks 20' of FIGS. 4 through 6 in such a manner that the strips of adjacent members are at right angles to each other to give a resulting criss-cross appearance similar to that of parquet flooring. As indicated heretofore, the arrangement of the fibers is such that they are oriented essentially in planes which are perpendicular to the furnace wall. This tends to eliminate or minimize the occurance of cracks which result from heat shrinkage of ceramic fibers. The arrangement shown in FIG. 11 tends to minimize or offset lineal shrinkage of the strips themselves.
The method and apparatus for insulating a furnace wall must be adaptable to walls which do not correspond, dimensionally, to the usage of nominal twelve inch by twelve inch insulating members. Also, it is recognized that the method and apparatus for insulating a furnace should be adaptable to furnaces which have irregularly shaped burner blocks and flue openings. As shown in FIG. 12, it is possible to arrange and attach a plurality of insulating members 20' to the surface 32' of a furnace not readily adaptable for the close end-to-end, side-to-side, arrangement shown in FIG. 11. In the case of FIG. 12, spaces 58 are provided between adjacent insulating members 20' in longitudinal or transverse or both, directions, depending upon the dimensional limitations of the furnace. The resulting spaces 58 can now be filled with specially folded ceramic fiber blankets such as shown in FIGS. 13, 14 and 15. The three fillers shown in the latter three figures are constructed in substantially the same way as the strips 22; that is, they are cut from a one inch thickness of four pound density ceramic fiber blanket and folded over.
In FIG. 15, there would be a single sheet 60 which is folded once so that its upper edges 62 provide the same type of end or edge fiber exposure referred to herein. If the resulting space is larger than two inches wide, then it is possible to go to the configuration shown in FIG. 13 which is comprised of two strips 64 and 66, which are cut in the same manner described above. The central strip 66 is relatively narrow in a vertical direction and the outer strip 64 is sufficiently wide that it can be folded around the central strip 66 as shown, the upper surfaces of strips 64 and 66 both providing the end or edge fiber arrangement referred to above.
Again, if the resulting space between adjacent insulating members 20 or between an insulating member 20 and a duct, etc. is greater than three inches, then it might be desirable to use the configuration shown in FIG. 14 where an additional central strip 68 is provided. This strip 68 will lie adjacent the strip 66 and an outer strip 70, slightly greater in width than the strip 64 will be folded over the central strips 66 and 68 to provide the arrangement shown.
The different embodiments shown in FIGS. 13, 14 and 15 can be held in place by ceramic cement, stainless steel wire or by the friction between the fibers alone.
FURTHER EMBODIMENTS AND MODIFICATIONS
Whereas the method of assembling the mat as described in relation to FIGS. 1 to 3 has been set forth in terms of wires 24, fasteners 30, etc. it should be understood that other methods could be employed to hold the strips together and to attach them to the backing insulation block. For example, the ceramic fiber strips could be attached to each other by means of suitable ceramic cements or mortar materials which are preferably utilized in the area adjacent the cold face of the fiber mat. Also, although the mats have been shown as being connected to a backing insulation block prior to application to a furnace wall, the mats could be applied directly to the furnace wall.
As far as the manner of fastening is concerned, the foregoing disclosure indicates that the mat of FIG. 1 or the composite block of FIG. 4 can be attached to a furnace wall by means of mortar, ceramic cement or various metallic fasteners. Since the ceramic cement or mortar will generally be located adjacent the cold face of the insulating member, there should be no particular high temperature problem as far as the cement or mortar is concerned; however, where metallic fasteners are concerned, it is generally recognized that alloy pins, bolts, washers and screws which could be used as fasteners have a maximum temperature limit in the range of 2000° to 2100° F. By "burying" or imbedding the fastener in the insulating member at a position spaced from the hot face thereof, as disclosed in the present invention, it is possible to use alloy pins, bolts, etc. without, at the same time, exposing these metallic fasteners to such high temperatures as would interfere with their effectiveness.
Although it is indicated that the mat of FIG. 1 could be applied directly to a furnace wall by means of ceramic cement or mortar, it is possible to precondition the cold face of the mat to permit the use of the stud welding method of attachment disclosed herein. For example, if a layer of cement or mortar is imbedded in the mat along the cold face thereof and allowed to harden, it is obvious that the welding technique and fasteners described in connection with FIGS. 7 to 10 could be employed, although a shorter shank 38 obviously would be necessary. The making of such a cement or mortar layer at the cold face of the mat could also be done in connection with the use of a high temperature cloth or stainless steel wire mesh which would be applied to or imbedded in the mortar layer at the cold face of the mat to improve the fastening capabilities thereof.
Referring now to FIGS. 4 through 7, a suitable insulating block 20' designed for operation at 1800° F. is one where the backing block or mineral block 28 is about two inches in thickness and the strips 22' are approximately one inch in width giving a total width of the block, from the cold face to the hot face thereof, of about three inches. A suitable insulating block 20' designed for operation at 2600° F. is one where the mineral block 28 is also two inches in thickness but where the strips 22' are four inches in thickness giving an overall dimension of six inches from the cold face to the hot face. By using strips 22 varying in width from one inch to five inches or more, depending upon the requirements of the particular furnace, it should be apparent that insulating blocks and/or mats could be employed to cover the recommended range of 1600° F. to 2800° F.
Although the block 28 has been referred to as a mineral block whose composition and properties are well recognized in the art, it is also possible to use asbestos block or calcium silicate block, these blocks being relatively rigid, especially as compared to the fiber mat or strips, so as to provide relatively rigid backing material for the mat. The strips 22 or 22' of the ceramic fiber mat 20 or 20', respectively, are preferably cut from a ceramic fiber blanket having a density of four pounds per cubic foot. It is understood that the manufacturers provide ceramic fiber blankets which are available in densities ranging generally from three to fourteen pounds per cubic foot. In the specific examples referred to herein, the ceramic fiber material has a density of four pounds per cubic foot. However, it should be understood that there might be portions of the furnace where the lining would be subject to gas currents which would give rise to erosion problems and, also, that the furnace might have various access openings which would require a lining of greater physical strength or density upon or surrounding the openings; in either of the latter two cases it might be desirable to use a ceramic fiber material of a higher density in the available range referred to above.
Naturally, it is desirable to insulate a furnace wall in such a manner that the outside (cold face) of the furnace is at a minimum temperature. However, it is recognized that this minimum temperature will be dependent upon a number of different factors including, but not limited to, the type, thickness and strength of the outside furnace wall; and prevailing air currents outside of the furnace wall. The use of the present invention will provide an outside temperature varying between 200° F. and 350° F. which is considered to be an acceptable range.
The preferred embodiment of the present invention, as disclosed above, describes the high-temperature insulating fibers which constitute the mat as "ceramic" fibers. However, this invention should not be tied down to any precise definition of "ceramic"; any high temperature insulating fiber which possesses properties similar to the ceramic fibers indicated herein and capable of operating above 1600° F. could be used in conjunction with the present invention and should be considered as falling within the scope thereof.
Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications apart from those shown or suggested herein may be made within the spirit and scope of this invention.
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A ceramic fiber mat attached to the interior wall or surface of a high temperature chamber of furnace or adapted to overlie an intermediate insulating member positioned between the mat and a furnace wall, the fibers in the mat lying in planes generally perpendicular to the wall, the mat constituting an improved insulation for the wall where the interior of the chamber or furnace will be operating at temperatures in excess of 1600° F.
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FIELD OF THE INVENTION
[0001] This invention is in the field of child safety and security.
BACKGROUND OF THE INVENTION
[0002] Unencumbered access to playground ladders by toddlers can result in tragic accidents especially when adults are not present to supervise play on ladders. Although in the majority of instances there is no accident, when a fall by a toddler from ladder does occur it can result in serious injuries that require medical attention. Additionally, adults or other persons could injure themselves rushing to reach a child who has climbed on to a ladder.
[0003] The above problems occur in a variety of settings including homes, schools or municipal parks. It is therefore desirable to secure play structure ladders from being climbed on when a school play area is not in use or supervised. Currently there is no cost effective solution other than removing the ladder should a school wish to pursue this option.
[0004] It is desirable to prevent unsupervised ladder climbing on play structures by children not capable of safely climbing on the ladders.
SUMMARY OF INVENTION
[0005] The invention is a safety sheet device having of a long sheet of thin plastic or other material, such as polyurethane foam, in sufficient length capable of spanning the ladder rungs and wide enough to make the ladder unusable when attached. Another objective of the present invention is to provide a safety sheet device that is made of polymer, colorants and UV light absorbers that can be safely handled and non-toxic to adults and children.
[0006] In one embodiment of the invention, the safety sheet device has a tying or attachment mechanism that allows one end to be snapped into place or mechanically fastened to the opposite end after it has been wrapped around the ladder.
[0007] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0009] FIG. 1 is a perspective view of a play structure having a ladder;
[0010] FIG. 2 is a cross-sectional side view of a play structure ladder with a safety sheet device connected in accordance with one embodiment of the invention;
[0011] FIG. 3 is a cross-sectional side view of a play structure ladder with a safety sheet device connected in accordance with a second embodiment of the invention;
[0012] FIG. 4 is an exploded cross-sectional view of an alternate arrangement for connecting the safety sheet device to the play structure;
[0013] FIG. 5 is an exploded perspective view of an alternate attachment arrangement for the safety sheet device;
[0014] FIG. 6 is an exploded perspective view of another alternate connection arrangement for the safety sheet device; and
[0015] FIG. 7 is a perspective view of the safety sheet device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
[0017] Referring now to FIG. 1 of the present application, a play structure arrangement 10 is shown. The play structure arrangement 10 has a platform 16 with a ladder 12 connected. A safety sheet device 14 is shown connected to the ladder 12 . The play structure arrangement 10 can have many different forms, but generally includes a platform 16 , or a place where the ladder 12 is connected in addition some other sort of device. In the present example, the play structure arrangement 10 includes a slide connected to the platform 16 which is elevated off of the ground on posts. Other play apparatuses can be connected. For example, as shown in FIG. 1 , there are two swings that form part of the play structure arrangement 10 . It is also within the scope of this invention for the safety sheet device 14 to be used for other ladders that are not necessarily connected to a platform 16 . For example, a play structure commonly referred to as “monkey bars” has a ladder that is not always connected to a platform. It is within the scope of the invention for the safety sheet device 14 to be used on any type of ladder including work ladders, pool ladders, loft ladders, etc.
[0018] Referring to FIGS. 1-2 , the connection of the safety sheet device 14 to the ladder 12 is described. As shown in FIG. 1 , the ladder 12 has a top rung 18 , bottom rung 20 , and a plurality of rungs 22 positioned between the top rung 18 and the bottom rung 20 . All of the rungs 18 , 20 , 22 are connected between at least two stringers 24 . It is within the scope of this invention for a greater or lesser number of stringers 24 to be used as well as a greater or lesser number or rungs 18 , 20 , 22 . The ladder 12 further includes a front side 26 and a back side 28 . The front side 26 is the side of the ladder 12 that the user will climb up to gain access to the platform 16 of the play structure 10 .
[0019] Referring briefly to FIG. 7 , the structure of the safety sheet device 14 is shown and described. The safety sheet device 14 has a suitable length “L” for connection to the play structure 10 , shown in FIG. 1 . The safety sheet device 14 also has a width “W” that is of sufficient size to extend across the ladder 12 between the stringers 24 , shown in FIG. 1 . However, it is possible to use a safety sheet device 14 that has a width that does not extend entirely between the stringers 24 , but rather is of sufficient width to render the ladder 12 unusable. The length “L” of the safety sheet device 14 will depend upon the height or length of the ladder 12 as well as the particular embodiment of the safety sheet device being used. The safety sheet device 14 is made of a flexible polymer material that includes plastics generally, as well as specific polymers from the group including polyurethane foam, polyamides, polyesters, neoprene, nitrile rubber, styrenes, and vinyl. Additionally non-toxic colorants such as clay, mica and calcium carbonate combined with the various polymer resins are used to enhance the safety of the polymer-colorant system when the safety sheet device 14 is handled. Additional possible materials include UV light absorbers, such as Milestab 81™ (2-Hydroxy-4-Octyloxy Benzophenone) from MPI Chemie of the Netherlands, can be added to the polymer matrix to increase the resistance of the safety sheet from destruction from sunlight. The safety sheet device 14 shown in FIG. 7 also includes a plurality of optional flutes 27 that may be molded into the safety sheet device 14 to provide points of flexation. The flutes 27 are optional and it is within the scope of this invention for the safety sheet device 14 to not have the flutes 27 . The safety sheet device shown in FIG. 7 has opposite ends 29 located at each end of the length “L”. Located at or near the opposite ends 29 are fasteners 30 , 32 that are used to secure the safety sheet device 14 in place. FIG. 7 depicts a hook and loop or Velcro™ fastener arrangement that includes a first fastener 30 and a second fastener 32 located near the opposite ends 29 of the safety sheet device 14 . The first fastener 30 is connected to a first surface 34 of the safety sheet device 14 while the fastener 32 is connected to a second surface 36 of the safety sheet device 14 opposite the first surface 34 . Placement of the first and second fasteners 30 , 32 on the respective first and second surfaces 34 , 36 allows for the two opposite ends 29 of the safety sheet device 14 to overlap at a connect area 38 for wrapping the safety sheet device 14 in a circular or loop shaped position around the top rung 18 and bottom rung 20 of the ladder 12 . This is shown in FIG. 2 .
[0020] FIG. 2 shows one embodiment of the safety sheet device 14 where the safety sheet device 14 wraps around the top rung 18 and bottom rung 20 and is connected together at the connect area 38 on the backside 28 of the ladder 12 using the fasteners 30 , 32 . It is within the scope of this invention for the connect area 38 to be located on the front side 26 of the ladder 12 depending on the particular application. Wrapping the safety sheet device 14 around the top rung 18 and bottom rung 20 of the ladder 12 using the hook and loop fasteners 30 , 32 renders the ladder 12 immobile since a small child, such as a toddler or infant, cannot access the covered rungs 18 , 20 , 22 of the ladder. While FIG. 2 depicts the safety sheet device 14 covering all of the rungs of the ladder 12 , it is also within the scope of the invention for a lesser number of rungs to be covered by the safety sheet device 14 . Additionally, depending on the number of rungs 18 , 20 , 22 on the ladder 12 , the length “L” of the safety sheet device can be varied either by manually trimming the safety sheet device 14 or having different sized safety sheet devices available for covering a number of different rungs. The size of the fasteners or the number of fasteners 30 , 32 can also be varied to provide a means of adjusting the size of the safety sheet device 14 when it is connected to the ladder 12 .
[0021] Referring to FIG. 3 , an alternate embodiment of the invention is shown which includes a safety sheet device 114 that does not wrap around the top and bottom rungs 18 , 20 of the ladder 12 , but rather covers just the front side 26 of the ladder 12 . This particular embodiment of the safety sheet device 114 attaches to the platform 16 at a first connection 40 . The second end of the safety sheet device has a second connection 42 that is used to connect to the bottom rung 20 of the ladder 12 .
[0022] Referring now to FIG. 4 , an exploded cross-sectional view of the first connection 40 is shown. The first connection 40 in this particular embodiment of the invention is a snap fastener having a male half 44 connected to the safety sheet device 14 using a retainer 46 . A female half 48 of the snap fastener is connected to the platform 16 using a fastener 50 . While the female half 48 is shown as being fastened to the platform 16 , it is within the scope this invention for a female half 48 to be connected another structure aside from the platform 16 and connected to other alternate structures such as the stringers 24 or other structures. Also, it is within the scope of this invention for multiple snap fasteners to be used even though only a single snap fastener is shown. The female half 48 is configured to receive and retain the male half 44 .
[0023] Referring now to FIG. 6 , an exploded perspective view of the second connection 42 is shown. The second connection includes an L-clamp 54 that is connected to the safety sheet device 14 . The L-clamp 54 is shaped to resiliently clamp or grasp the bottom rung 20 of the ladder 12 . While FIG. 3 shows the second connection 42 being connected to the bottom rung 20 , it is within the scope of this invention for the connection to be made with any of the rungs 18 , 20 , 22 . It is also within the scope of this invention for both the first connection 40 and second connection 42 to consist of two L-clamps 54 connected to the safety sheet device 14 , where the safety sheet device 14 would be stretched between the top rung 18 and bottom rung 20 , or between any two of the rungs 18 , 20 , 22 of the ladder 12 . It is also within the scope of the invention for the L-claims 54 to have a different shape depending on the cross-sectional shape of the rungs 18 , 20 , 22 .
[0024] Referring now to FIG. 5 , an additional alternate connection that can be used for the first connection 40 and second connection 42 are shown. This particular alternate connection uses a C-clamp 52 connected to the safety sheet device 14 . The C-clamp 52 can be used near both of the opposite attachment ends 29 or various combinations of the different connections described herein can be used. The C-clamp 52 is shaped to resiliently clamp on or grasp one of the rungs 18 , 20 , 22 . In the embodiments described in FIGS. 5 and 6 , the C-clamp 52 or L-clamp 54 may be attached to the safety sheet device 14 using adhesives, fasteners or hook and loop connections as well as any other suitable attachment mechanism. Generally speaking, the fasteners or connections between the safety sheet device and the platform, stringers or rungs can be accomplished using buttons, snaps, hooks, magnets, clips and strings connected at the connect area 38 , or between the rungs, platform, stringers or other structures.
[0025] The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
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Many family homes, school and municipal parks have play structures for children. Typically these playground play structures have ladders. In the case of family homes in particular, toddlers typically enjoy climbing the ladders but then are stuck at the top and in danger of falling off the ladder. In order to prevent toddlers from climbing the ladder of the play structures when unattended by an adult, and ultimately preventing injury, an invention that prevents the ladder from being climbed by a toddler is presented here.
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RELATED APPLICATIONS
[0001] This is a continuation-in-part of, and claims priority to, Provisional Patent Application No. 60/224,721, filed Aug. 11, 2000, the entire contents of which are hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to lithium batteries. More particularly, the invention relates to lithium batteries that have a liquid electrolyte, but enjoy the mechanical advantages of a solid phase electrolyte without sacrificing the electrochemical advantages of a liquid electrolyte.
[0004] 2. Description of the Prior Art
[0005] The advantages and construction of lithium batteries are well known. See, for example, Tsutsumi et al. U.S. Pat. No. 5,998,065, and Kim et al. U.S. Pat. No. 6,001,509. Lithium batteries serve well as secondary batteries, and are capable of being reduced in size as compared with present battery designs that are widely used. They are also capable of being reduced in weight so that in the areas, for example, of form factor, size, weight, safety and capacity, lithium batteries substantially exceed the capabilities of the present designs. Difficulties have been encountered, however, in devising satisfactory electrolyte-separator combinations that would maximize the potential available in the lithium battery technology.
[0006] Previously, both liquid or gel organic electrolyte and solid phase electrolyte lithium batteries have been proposed. The liquid electrolyte based designs previously suffered from substantial problems of safety and utility due to the inherent nature of the liquid phase electrolyte. It leaked out of the container if the container was ruptured. This destroyed the utility of the battery and risked, for example, fire, explosion, toxic release, and damage to expensive equipment. In general, the previous liquid electrolyte based lithium battery designs were fragile. The previous liquid based designs did, however, enjoy the advantage that they could be put through many charge-discharge cycles without significant loss of function. Also, prior liquid electrolyte based lithium batteries could be charged and discharged rapidly without undue heat build up, because the resistance of the liquid electrolyte was low. By contrast, prior solid electrolyte based lithium battery designs were rugged, but suffered from excessive heat build up during rapid charging and discharging, and were only good for a limited number of charge-discharge cycles.
[0007] It had previously been proposed to modify the surface energy of a reticulated polystyrene foam separator in a lithium battery so as to promote the retention of a liquid electrolyte within the pores of the separator. Such previous proposals involved, for example, incorporating a molecule in the polymer chain of the solid phase polystyrene that would increase its surface energy. Sulfonate containing molecules had been proposed for this purpose. The inclusion of sulfonate or other surface energy modifying molecules within the skeleton of the solid phase polymer caused an undesired negative impact on the physical properties of polystyrene. Alternatively, previous proposed expedients for increasing the surface energy of the porous separators in lithium batteries often required that the electrolyte be prepared separately from the skeleton so that the walls of the skeleton could be washed with a surfactant before the liquid electrolyte was added. This contributed undesirably to the cost and complexity of the manufacturing procedure. Also, the retention of the liquid electrolyte within the foam skeleton was less than unsatisfactory.
[0008] Itho U.S. Pat. No. 4,849,311 discloses an ionic conductor, liquid or solid, that is immobilized in the pores of a porous solid polymer membrane. Immobilization of the liquid ionic conductor is said to be accomplished by the combination of using pore sizes of less than 0.1 microns, an appropriate choice of solvent, and surface treatment. The disclosed surface treatments to control the wetability of the polymer membrane are plasma and graft polymerization on the surface. The liquid contact angle to the polymer is said to be not more than 90, and preferably not more than 70 degrees. Neither the use of nor the need for a solid surfactant at the interface between the solid and liquid phases is suggested.
[0009] The inclusion of solid surfactants in foamed thermoplastic materials is known. See, for example, Cobbs et al. U.S. Pat. No. 4,156,754. According to The disclosure of Cobb et al. a finely divided surfactant is mixed with a gas containing molten thermoplastic to stabilize the gas.
[0010] Those concerned with these problems recognize the need for an improved lithium battery.
BRIEF SUMMARY OF THE INVENTION
[0011] The present invention captures the advantages of both the liquid and solid phase electrolyte lithium batteries by providing for the retention of the gel electrolyte within the battery even if the container is punctured. It enjoys the mechanical and safety advantages of the solid phase designs, and the electrochemical advantages of the liquid or gel phase designs. The present invention is particularly concerned with the retention of the gel electrolyte within the pores in a reticulated foam separator. The gel electrolyte is retained according to the present invention because it aggressively wets the walls of the pores. The gel electrolyte is encouraged to aggressively wet the walls of the foam separator, for example, by the presence of a solid phase surfactant in the separator-gel electrolyte system.
[0012] The reticulated solid phase foam is formed from a liquid phase mixture that preferably contains substantially all of the ingredients for both the foam and the electrolyte, including the compositions to form a finely divided solid phase surfactant. The ingredients are formed into a liquid phase mixture. The liquid phase mixture is then cast or otherwise formed into the desired shape, and dried or otherwise treated to form a solid phase reticulated foam skeleton and a formed in situ gel phase electrolyte entrained therein. When the solid phase skeleton forms, the gel phase electrolyte is present as a dispersed interconnected inclusion within the solid phase. The solid phase surfactant precipitates and is also present, particularly at the interface between the gel and solid phases. The solid phase surfactant generally preferentially collects at this gel-solid interface.
[0013] According to the present invention a solid phase powder which is not soluble in the electrolyte to any significant degree is formed in situ as the system forms so that solid phase particles of surfactant are distributed throughout at least the surface of the reticulated foam as it is formed. The exact mechanism is not known, and applicant does not wish to be bound by any particular theory. These finely divided solid phase surfactant powders appear to be bound physically to the surface of the solid phase skeleton. The presence of these solid particles apparently causes the gel phase electrolyte to thoroughly wet the surface of the reticulated foam. As a result, the gel-electrolyte stays in the foam, even when the foam is punctured, and the battery continues to operate. Lithium batteries with punctured container walls can even be recharged, if necessary. The solid phase surfactant must be selected so that it also retains its surfactant properties under the conditions that are encountered within the battery during its useful life.
[0014] During the formation of the microcomposite structure the solvent is removed from the liquid phase mixture until the microcomposite structure forms. The solid and the gel phases all form in situ. The gel-electrolyte forms in situ in the pores of the solid polymer, and is stabilized there by the solid phase surfactant.
[0015] Lithium batteries constructed according to the present invention find particular application in, for example, medical devices, communication devices, lap top computers, microelectronics of various types, aerospace and defense applications, solar energy applications, electric vehicle uses, battery clothing such as a battery vest, and the like. Rechargeable liquid or gel electrolyte lithium ion batteries offer significant advantages in energy density and cycle life over of the principal rechargeable battery technologies that are currently in use. Such lithium batteries offer very high gravimetric and volumetric energy densities. Such batteries can also generally be configured into substantially any geometric configuration that may be required by a particular application.
[0016] The present invention provides its benefits across a broad spectrum of batteries. While the description which follows hereinafter is meant to be representative of a number of such applications, it is not exhaustive. As those skilled in the art will recognize, the basic methods and apparatus taught herein can be readily adapted to many uses. It is applicant's intent that this specification and the claims appended hereto be accorded a breadth in keeping with the scope and spirit of the Invention being disclosed despite what might appear to be limiting language imposed by the requirements of referring to the specific examples disclosed.
[0017] Other objects, advantages, and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Referring particularly to the drawings for the purposes of illustration only and not limitation:
[0019] [0019]FIG. 1 is a magnified cross-sectional view of a preferred embodiment of the invention taken with a scanning electron microscope at a magnification of 126 times showing a metallic coated fiberglass mat between an anode and a cathode with formed in situ gel phase inclusions visible in the pores.
[0020] [0020]FIG. 2 is a magnified plan view of a preferred embodiment of the invention taken with a scanning electron microscope at a magnification of 1.00 K times showing the surface of a microcomposite structure from which most of the gel has been evaporated.
[0021] [0021]FIG. 3 is a magnified plan view of a preferred embodiment of the invention taken with a scanning electron microscope at a magnification of 17.41 K times showing the surface of a microcomposite structure from which most of the gel phase has been evaporated.
[0022] [0022]FIG. 4 is a magnified cross-sectional view of a preferred embodiment of the invention taken with a scanning electron microscope at a magnification of 55 times showing the edge of a microcomposite structure of an anode-separator-cathode in which the gel is visible as inclusions.
[0023] [0023]FIG. 5 is a magnified view of a preferred embodiment of the invention taken with a scanning electron microscope at a magnification of 2.50 K times showing a metallic coated fiberglass filament in a microcomposite structure from which most of the gel phase has been evaporated.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
EXAMPLES
[0024] A preferred separator for a lithium-ion battery was prepared by forming a solution comprising a polymer blend that included 0.45 grams of polyvinyl chloride (PVC) having approximately 242,000 molecular units, 0.15 grams of polystyrene (PS) having approximately 283,000 molecular units. The solution also included 0.30 grams of the electrolyte salt, lithium hexaphosphide (LH), and 0.3 grams of the anionic surfactant, lithium toluene sulfonate (LTS). An aprotic solvent system for dissolving the PVC, PS and LH was prepared. The aprotic solvent system included 0.15 grams of propylene carbonate, 0.10 grams of dimethyl carbonate, 0.15 grams of ethylene carbonate, and 5 grams of tetrahydrofuran. A second solvent system was prepared for dissolving the LTS. The second solvent system comprised 1 gram of ethanol and 0.5 grams of acetone. The phase separation of the PVC and PS was controlled by the addition of 1.5 grams of a cyclohexane. Cyclohexane is a liquid that is soluble in the aprotic solvent system but does not dissolve the PVC or PS. About 0.05 grams of Crown ether 12 (Merck &Co.) were added to improve the efficiency of any battery that is made using the resulting separator.
[0025] All of the ingredients were mixed together, and the solution was well stirred in an environment with a dry argon atmosphere. The argon contained less than 1 part per million of water vapor. The solution was then cast on a flat horizontal glass plate to form a sheet of liquid having a thickness of about 400 microns. Dry argon was flowed over the cast solution at a rate of about 8 meters per second during the evaporation step. The temperature of the plate and the argon were maintained at about 25 degrees centigrade. After about 30 minutes a solid phase began to appear in the liquid sheet. After about 120 minutes the cast separator appeared to be dry to the touch. The formed separator was separated from the plate. The free standing cast separator was approximately 100 microns thick. Upon examination the microcomposite structure was found to include a continuous gel phase and a continuous solid support phase in the form of a reticulated membrane. As used herein, “gel” includes materials that range from flowable liquids to sols and gel materials that will substantially hold their shapes with some slumping when unsupported.
[0026] The gel-electrolyte serves to conduct lithium ions through the separator. It is essential that the formed in situ gel phase be continuous throughout the separator. About 2 hours after casting the microcomposite structure exhibited a conductivity of from about 3.8 to 5.2 milliSiemens per centimeter. The microcomposite structure was subjected to a vacuum of 0.001 torr for a period of 12 hours. The conductivity was then about 2.4 to 3.5-milliSiemens per centimeter. A control sample without a surfactant, but otherwise the same, exhibited 2 orders of magnitude less conductivity after being exposed to vacuum for 12 hours. The surfactant dramatically enhanced the retention of the gel in the pores of the support structure.
[0027] The reticulated structure was not fully organized in the sense that the pores were not uniform in either size or shape. The average pore size ranged from approximately 0.1 to 2 microns in size. See, for example, FIGS. 2, 3, and 5 .
[0028] While not intending to be bound by any theory, it is believed that in the finished microcomposite structure the surfactant appears as a fined grained precipitate formed in situ at the interface between the gel and solid phases, and causes the gel to wet the solid phase. This, it is believed, retards and substantially prevents the evaporation of the solvent from the gel phase. It is believed that the surfactant also retards the formation of the solid phase during the evaporation stage, and causes the formation of smaller pores and a better organized, more uniform reticulated solid phase. The accumulation of the solid phase surfactant at the gel-solid phase interface is particularly effective with the preferred polyvinyl chloride-polystyrene soild phase polymer system.
[0029] Repeating this example without the lithium toluene sulfonate produced a separator that quickly dried to the point where there was substantially no gel. The rate of solvent evaporation was much more rapid than with the surfactant containing structure. Also, the reticulated structure was less organized and the pore sizes varied more widely.
[0030] Repeating this example using hexane, or toluene, or benzene, or tetrachloroethylene, or tetrachloroethane, or mixtures thereof, and the like, as the non-solvent for the PVC and PS polymers, instead of cyclohexane, produces satisfactory results.
[0031] The selection of the specific quantities and proportions of the various components of the liquid phase mixture from which the microcomposite structure is formed depends on the nature of the various components. Changing one component often necessitates a change in the quantities and proportions of the other components. Changing, for example, the molecular weight or proportions of the polymer blend often requires an adjustment in the aprotic solvent system. There should be a sufficient amount of the aprotic solvent system to dissolve the polymer blend. There should be a sufficient amount of surfactant to stabilize the gel phase in the pores of the solid polymer phase, and there should be a sufficient amount of surfactant solvent system to dissolve the surfactant. There should be sufficient phase separation liquid to cause the solid polymer phase to form as the aprotic solvent system evaporates. Those skilled in the art will be able, without undue experimentation, to determine the proper proportions and concentrations from these guidelines. In general, it is believed that formation of the microcomposite structure occurs primarily through physical phase changes rather than chemical reactions.
[0032] Repeating this example replacing the solvents in the aprotic solvent system with butylene carbonate, diethylcarbonate, dipropyl carbonate, ethyl methyl carbonate, 1,2-dimethoxymethane, 1,2-diethoxyethane, 1,2-dibutoxyethane, and 2-methyltetrahydrofuran, and the like, produces satisfactory results.
[0033] Repeating this example using polyvinyl chloride polymers with molecular weights ranging from approximately 43,000 to 250,000 molecular units, and the like, produces satisfactory results. The structural properties of the microcomposite structure degrade as the molecular weight of the polyvinyl chloride decreases, and the electrical conductivity improves.
[0034] Repeating this example using polystyrene polymers with molecular weights ranging from approximately 60,000 to 290,000 molecular units, and the like, produces satisfactory results. The structural properties of the microcomposite structure degrade as the molecular weight decreases, but the electrical properties remain substantially constant.
[0035] Repeating this example using polystyrene to polyvinyl chloride ratios of from about 0.05:1 to 0.6:1 produces satisfactory results. Where the proportions of the polystyrene are low, the electrical conductivity is high but the physical properties are poor. Increasing the proportion of the polystyrene increases the physical properties at the expense of the electrical properties.
[0036] Repeating this example using lithium styrene sulfonate, or other lithium salts of anionic surfactants, and the like, produces satisfactory results. Suitable anionic surfactants include, for example, the lithium salts of alkylaryl sulfonates where the aromatic portion of the molecule has been sulfonated, and the like.
[0037] Satisfactory results are achieved from separators that are produced having average pore sizes ranging from approximately 0.1 to 10 microns.
[0038] The present invention has been described by reference to the preparation of a separator for a lithium-ion battery. The same structures, with different but well known additives in the gel phase serve equally well as anodes or cathodes, or the like in, for example, secondary lithium-ion batteries. The microcomposite structure can be formed so that the anode, separator and cathode are essential all one continuous microcomposite structure with each one grading into the one adjacent to it. See, for example, FIG. 1. When loaded with the active ingredients that permit it to function as a separator, the structure is positioned between an anode and a cathode in a lithium-ion battery so that lithium-ions flow between the adjacent electrodes through the gel-electrolyte phase. The microcomposite structure can be cast on a support such as a web. Suitable supporting web materials include, for example, fiberglass, conductively coated fiberglass, and the like. See, for example, FIGS. 1 and 5. When coated with conductive materials such as aluminum, copper, nickel, stainless steel of the 30 and 400 series, and the like, the supporting web serves as a current collector. Such conductive coatings can be applied, for example, on fiberglass to a thickness of 0.1 to 5, preferably 1 to 2 microns by magnetron sputtering, or the like,
[0039] Repeating this example using LiPF 6 , LiCIO 4 , LiAsF 6 , LiBF 4 , LiAICl 4 , CH 3 SO 3 Li, CF 3 SO 3 Li, LiB(C 6 H 5 ) 4 , and CF 3 COOLi, and the like, in place of the lithium hexaphosphide electrolyte salt produces satisfactory results.
[0040] Repeating this example using methanol or propanol, and methyl ethyl ketone, and the like, in place of the ethanol and acetone solvent systems produces satisfactory results. Other suitable solvent systems for the anionic surfactant include, for example, ethyl ketone, butanol, and diethyl ketone.
[0041] Satisfactory results are obtained operating the casting step at temperatures ranging from approximately −10 to +80 degrees centigrade.
[0042] Repeating the evaporating step of this example in an atmosphere of air, the moisture content of the air was reduced to the point where the dew point of the air was less than about −60 degrees centigrade. Satisfactory results were achieved.
[0043] The microcomposite structure can be formed by batch or continuous operations. In continuous operations the structure is typically cast on a moving belt or web. The respective electrodes and separator can be formed and then joined to one another in a continuous operation. If the solvent level is at the level where the structure is tacky, the respective elements of the structure adhere to one another. The solvent level can be adjusted to the tacky level by, for example, joining the elements before the solvent has evaporated or by the application of additional solvent to a substantially dry feeling element.
[0044] After the initial solution is cast, the solvents evaporate until there are only enough of the solvents left to form a gel. At this point the rate of the evaporation of the solvent decreases dramatically to a very low value. The evaporation of the solvents decreases dramatically at the gel stage because the gel includes a surfactant. Without the presence of the surfactant, evaporation of the solvents would continue at a rapid rate and the gel phase could not be sustained. When used as a component in a battery, the microcomposite structure is preferably enclosed within a sealed container so that the evaporation of the solvent is essentially stopped.
[0045] While not intending to be bound by any particular theory, the gel phase electrolyte is believed to be comprised primarily of polyvinyl chloride, polystyrene, and solvents, with minor but effective amounts of surfactant and electrolyte salt.
[0046] The ingredients in the initial solution, and the conditions in the casting and evaporating steps determine the character of both the solid reticulated and gel-electrolyte phases. The presence of a surfactant in the initial solution promotes the formation of smaller open cells, and a somewhat better organized (more regular) reticulated structure.
[0047] The essential ingredients in the initial solution for the formation of the microcomposite structure include a polymer blend, preferably of polyvinyl chloride, polystyrene, a surfactant that will cause the gel to wet the solid phase, an aprotic solvent system for the polymer blend, a solvent system for the surfactant, and a liquid non-solvent for the polymer blend that is soluble in the aprotic solvent. For the microcomposite structure to function, for example, as a separator in a lithium-ion battery the initial solution must also include an electrolyte salt and a solvent for that salt. Preferably, the solvent for the electrolyte salt is provided by the aprotic solvent system. The mobility of the lithium ions through the separator depends on maintaining the gel phase. If the gel phase disappears, the mobility of the lithium ions is drastically reduced or eliminated.
[0048] What have been described are preferred embodiments in which modifications and changes may be made without departing from the spirit and scope of the accompanying claims. Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
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A microcomposite structure for use as a component of a lithium battery is formed from a liquid phase mixture by the removal of a solvent. The microcomposite structure includes a continuous reticulated solid polymer phase, a formed in situ gel-electrolyte phase, and a solid phase surfactant at the interface between the gel and polymer phases for stabilizing the gel phase within the pores of the solid polymer phase. The liquid phase mixture comprises a polymer blend, an aprotic solvent system for the polymer blend, a substantially dissolved anionic surfactant, and a phase separation liquid that is miscible with the aprotic solvent system, but in which the polymer blend is substantially insoluble. The microcomposite structure is formed by casting the liquid phase mixture on a surface and removing solvent until the microcomposite structure forms.
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RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 09/819,590 filed Mar. 27, 2001, entitled “WINDOW PROTECTOR ASSEMBLY” which was a continuation-in-part of U.S. patent application Ser. No. 09/397,748, filed Sep. 16, 1999, entitled “WINDOW PROTECTOR ASSEMBLY” now U.S. Pat. No. 6,206,453, issued Mar. 27, 2001. This application also claims priority from U.S. patent application Ser. No. 09/819,590 filed Mar. 27, 2001, and U.S. Provisional Application Serial No. 60/244,402 filed Oct. 30, 2000, and U.S. patent application Ser. No. 09/395,692 filed Sep. 13, 1999, and U.S. patent application Ser. No. 09/186,513 (now U.S. Pat. No. 6,205,723) filed Nov. 4, 1998.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to protective devices for protecting windows from damage and, more specifically, concerns a replaceable window protector assembly adapted to both protect glazing used in windows in public transportation vehicles and also allow for the replacement of the same.
[0004] 2. Description of the Related Art
[0005] Vandalism of windows in public transportation vehicles has been an ongoing problem for decades. Vandals cause damage by writing or painting on the glazing of the window with marking pens or spray paint. Further, vandals often damage the exposed glazing of the window by scratching the glazing with sharp instruments.
[0006] Oftentimes, the vandal is a passenger that damages the interior surface of the glazing. However, the exterior surface of the glazing on public transportation vehicles are increasingly being defaced or vandalized. It will be appreciated that the vandalism usually takes the form of crude or otherwise disagreeable expressions being permanently marked onto the windows. Hence, there is an on-going problem of vandalism and defacement of public transportation vehicles and, in particular, damage or defacement of both the interior and exterior surfaces of the glazing of these windows.
[0007] Likewise, unintentional breaking or fracturing of the glazing on public transportation vehicles has been an on-going problem as well. Oftentimes, road debris, interior debris, or passengers may accidentally strike the glazing with enough force to break or fracture it. Broken glazing presents an unacceptable hazard to passengers because the broken glazing can cut them. Also, fractured windows are unattractive and might cause a carrier to lose respect and business. Also, broken and fractured windows diminish the climate control capabilities of public transportation vehicles. Simply put, broken and fractured glazing must be replaced as soon as possible, but removal of the glazing is difficult and expensive. Hence, there is an on-going problem with the difficulty of replacing the glazing on public transportation vehicles.
[0008] To address these problems, various devices have been developed. For example, U.S. Pat. No. 5,242,207, which is owned by the assignee of this application, discloses one type of window protector which protects the interior surface of the glazing of the window from damage as a result of vandalism or defacement. In particular, U.S. Pat. No. 5,242,207 discloses a window protector which includes a protective sheet positioned against the interior surface of the glazing of the window and is held in place by a plurality of brackets which is attached to the frame of the window. This protective sheet acts as a sacrificial surface that protects the glazing of the window from damage as a result of vandalism or defacement. Whenever necessary, the protective sheet can be replaced with a new protective sheet by removing the brackets and positioning the new protective sheet adjacent the inner surface of the glazing of the window.
[0009] While the window protector disclosed in U.S. Pat. No. 5,242,207 has been effective in protecting the interior surface of the glazing of the window, this window protector does not provide protection against damage to the outer surface of the glazing of the window. Also, removing the interior protective sheet from the window protector disclosed in U.S. Pat. No. 5,242,207 requires of the retention brackets, and this process can increase the cost of maintenance and repair.
[0010] Moreover, the window protector disclosed in U.S. Pat. No. 5,242,207 is designed to be used in conjunction with the existing window frames of the transportation vehicle. These frames are not designed for quick glazing installation and are rigidly attached to the vehicle. Thus, when the glazing breaks, the broken pieces must be gathered from within the rigid frame, the entire frame must be removed from the vehicle and disassembled, new glazing must be inserted into the frame, the frame must be reassembled, and the entire assembly must be reinstalled into the vehicle. This tedious process can increase the cost of maintaining and repairing the public transportation vehicle windows.
[0011] From the foregoing, it will be appreciated that there is a need for an improved window protector that is capable of protecting both the interior surface and the exterior surface of the glazing of the window from damage as a result of vandalism or accident. It will also be appreciated that there is a need for an improved window protector that allows its owner to quickly replace both protective layers and the glazing in response to damage caused by vandalism or accident. To this end, there is a need for a window protector that provides protection to the window glazing on both the interior and exterior surfaces of the glazing and also allows for easy and quick access to the protective layers and the glazing itself.
SUMMARY OF THE INVENTION
[0012] The aforementioned needs are satisfied by one aspect of the invention which in one aspect relates to a window assembly mounted in a wall of a vehicle having an interior and an exterior surface. The assembly comprises a molded frame that is adapted to be positioned within the wall of the vehicle. The frame includes a transverse surface that extends through an opening in the wall and defines a window opening and an external perpendicular surface that is positioned adjacent the external surface of the wall of the vehicle when the frame is positioned within the wall. The frame further includes a seating member that extends inward from the transverse surface of the frame into the window opening such that the transverse surface of the frame and the seating member define a glazing mounting location. The frame further includes a flange that is offset from the seating member towards the interior surface of the vehicle and extends inward from the transverse surface of the frame into the window opening such that the flange is substantially parallel to the seating member. The seating member, the transverse surface, and the flange define a recess that extends substantially about at least two opposed sides of the window opening adjacent the interior surface of the vehicle. The assembly further comprises a piece of glazing positioned at the glazing mounting location within the frame of the vehicle so as to occupy the window opening. The seating member inhibits the piece of glazing from moving inwards towards the interior surface of the wall of the vehicle but permits the piece of glazing to be removed from the frame adjacent the exterior surface of the wall of the vehicle when the frame is positioned within the wall of the vehicle. The assembly further comprises a protective sheet positioned adjacent the piece of glazing such that at least two opposing edges of the protective sheet are positioned within the recess at the at least two opposed sides of the window.
[0013] In one embodiment, the recess is sized and positioned about the window opening and the protective sheet is sized such that when the protective sheet is positioned within the recess, the protective sheet can be moved in a first direction with respect to the recess such that a first edge of the protective sheet can be exposed from the recess to thereby permit removal of the protective sheet. The assembly further comprises a retainer that extends into the recess so as to inhibit movement of the protective sheet in the first direction so as to prevent the first edge of the protective sheet from being exposed from the recess so that the retainer inhibits removal of the protective sheet without previous removal of the retainer. The protective sheet preferably comprises a sheet of acrylic material.
[0014] In one embodiment, the assembly further comprises at least one retaining member pivotally attached to the frame so as to pivot outward from the exterior surface of the vehicle when the frame is positioned within the wall of the vehicle. The at least one retaining member is movable between an open position and a closed position such that the at least one retaining member in the open position allows the piece of glazing to be removed from the window opening of the frame adjacent the exterior surface of the wall of the vehicle and such that the at least one retaining member in the closed position retains the piece of glazing in the glazing mounting location in the closed position. The at least one retaining member is comprised of a first and a second U-shaped retaining members that are pivotally attached to the frame so as to extend substantially around the first perimeter of the frame when in the closed position. The first and second U-shaped retainers have first and second arms with beveled ends, wherein the beveled ends of the first and second arms of the first U-shaped retainer are positioned underneath the beveled ends of the first and second arms of the second U-shaped retainer when the first and second U-shaped retainers are in the closed position. At least one securing device is attached to the first U-shaped retainer so as to retain the first Ushaped retainer in the closed position. The fist U-shaped retainer has at least one opening and wherein the securing device comprises a securing member mounted within the at least one opening in the first U-shaped retainer so as to be rotatable therein. The securing member further includes a lateral member that rotates between a first position when the lateral member engages with the frame to retain the first U-shaped retainer in the closed position and a second position. The lateral member disengages with the frame to permit the first and second U-shaped members to be moved into the opened position. The securing member has a first exposed face that has an opening adapted to receive a tool having a first configuration so that positioning the tool having the first configuration into the opening permits manipulation of the securing member between the first and second positions.
[0015] In one embodiment, the assembly further comprises a protective sheet mounted between the glazing and the retaining member so as to be interposed between the exterior surface and the piece of glazing to thereby inhibit damage or defacement to the piece of glazing by persons or debris adjacent the exterior surface of the vehicle. Preferably, the protective sheet comprises a sheet of acrylic material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] [0016]FIG. 1 is an elevational view illustrating a public transportation vehicle incorporating windows having an embodiment of a window protector assembly of the present invention;
[0017] [0017]FIG. 2 is an inside elevational view illustrating the window protector assembly of FIG. 1;
[0018] [0018]FIGS. 3A and 3B are cross-sectional views of the window protector assembly of FIG. 2 taken along the lines of 3 - 3 ;
[0019] [0019]FIG. 4 is a cross-sectional view of the window protector assembly of FIG. 2 taken along the lines 4 - 4 ;
[0020] [0020]FIGS. 5A and 5B are perspective views of the window protector assembly of FIG. 2, illustrating the assembly in both a closed and an opened configuration;
[0021] [0021]FIGS. 6A and 6B are cross-sectional views of another embodiment of the window protector assembly of FIG. 2 illustrating another interconnection between retaining members of the window protector assembly and the frame of the window protector assembly;
[0022] [0022]FIG. 7 is a side cross-sectional view of a securing mechanism of the assembly of FIG. 2;
[0023] [0023]FIG. 8 is a top view of the securing mechanism of FIG. 2;
[0024] [0024]FIG. 9 is an elevational view of another embodiment of a public transportation vehicle incorporating windows having another embodiment of a window protector assembly of the present invention;
[0025] [0025]FIG. 10 is an outside elevational view illustrating the window protector of FIG. 9;
[0026] [0026]FIGS. 1A and 1B are cross-sectional views of the window protector assembly of FIG. 10 taken along the lines of 11 - 11 ;
[0027] [0027]FIG. 12 is a cross-sectional view of the window protector assembly of FIG. 10 taken along the lines of 12 - 12 ;
[0028] [0028]FIGS. 13A and 13B are perspective views of the window protector assembly of FIG. 10, illustrating the assembly in both a closed and an opened configuration;
[0029] [0029]FIG. 14 is a side cross-sectional view of a securing mechanism of the assembly of FIG. 10; and
[0030] [0030]FIG. 15 is a top view of the securing mechanism of FIG. 10.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0031] Reference will now be made to the drawings wherein like numerals refer to like parts throughout. FIG. 1 illustrates an exemplary public transportation vehicle 100 that incorporates windows 102 having window frames 114 mounted within openings 106 in the side wall 110 of the vehicle 100 . It will be appreciated from the following discussion that, while the window protector assembly of this embodiment is described in connection with a bus, that the window protector assembly 112 can be used in a number of different applications including other types of public transportation vehicles and also in windows that are positioned in fixed environments, such as buildings, where the window is likely to be damaged or defaced due to vandalism or accident. As will be also apparent from the following discussion, the window protector assembly of the preferred embodiment is designed to both protect the glazing of the window and also to facilitate rapid change and replacement of protective sheets and the glazing of the window protector assembly.
[0032] Referring to FIG. 2, one embodiment of a window protector assembly 112 is illustrated. In this embodiment, the window protector assembly 112 incorporates a frame 114 that is adapted to mount within the opening 106 in the side wall 110 of the vehicle 100 in a well-known manner. The frame 114 defines an opening 116 into which one or more pieces of glazing 120 are to be positioned. As will be understood, the term “glazing” refers to either glass windows or windows formed of any other generally transparent or translucent material.
[0033] In this embodiment, a first retaining member 122 and a second retaining member 124 are pivotally mounted to the frame 114 so as to be positioned about the outer perimeter of the opening 116 in the frame 114 . As is shown in FIG. 2, the first retaining member 122 is generally U-shaped having two arms 123 a , 123 b that extend along the side walls of the frame 114 and pivoting section 127 . Similarly, the second retaining member 124 is also generally U-shaped having a pivoting section 128 and two arms 125 a , 125 b that also extend along the side walls of the frame 114 so as to engage with the two arms 123 a , 123 b of the first retaining member 122 . The engagement between the arms 123 a , 123 b of the first retaining member 122 and the arms 125 a , 125 b of the second retaining member 124 secures the glazing and protective layers within the opening 116 of the frame 114 in a manner that will be described in greater detail below.
[0034] As will also be described in greater detail below in reference to FIGS. 5A and 5B, the pivoting section 127 of the first retaining member 122 and the pivoting section 128 of the second retaining member 124 are pivotally attached to the frame 114 so as to be pivotable between a closed position, as shown in FIG. 2, and an opened position whereby the outer perimeter of the glazing 120 and any protective layer is exposed. As is shown in FIG. 2, the arms and pivoting sections of the first retaining member 122 and the second retaining member 124 are selected to have a width sufficient so as to fully cover the outer edge of the glazing 120 and any protective layers positioned within the opening 116 of the frame 114 .
[0035] [0035]FIGS. 3A and 3B illustrate the interconnection between the first retaining member 122 and the second retaining member 124 and corresponding sections of the frame 114 . In particular, as illustrated in FIGS. 3A and 3B, the frame 114 includes an upper frame section 130 a and a lower frame section 130 b . The upper and lower frame sections 130 a , 130 b have an L-shaped section 132 that is suitable for mounting in the opening 106 of the side wall 110 of the vehicle 100 . In particular, the L-shaped section 132 has an exterior lip 134 that is adapted to mount flush against the outer surface of the side wall 110 of the vehicle adjacent the window openings 106 . The L-shaped section 132 further includes a laterally extending member 136 that is adapted to be positioned adjacent the inner walls of the openings 106 in the side walls 110 of the vehicle so as to extend substantially through the opening 106 .
[0036] A pivoting member 140 is formed on an inner wall 142 of the laterally extending member 136 so as to extend perpendicularly outward therefrom into the opening 116 defined by the frame 114 . As will be described in greater detail below, the pivoting member 140 extends the full length of the upper frame section 130 a and the lower frame section 130 b , and provides a surface to which the pivoting section 127 of the first retaining member 122 and the pivoting section 128 of the second retaining member 124 can be respectively attached to the frame 114 of the window protector assembly 112 .
[0037] The L-shaped section 132 also defines a seating member 144 that extends inward into the opening 116 defined by the window frame 114 . The seating member 144 is adapted to receive a seal 146 that is retained in the seating member 144 as a result of a deformable section 150 of the seal 146 being positioned within an opening 152 formed in the seating member 144 of the upper and lower frame members 130 a , 130 b . Hence, the seal 146 is press-fit within the seating member 144 of the upper frame section 130 a and lower frame section 130 b . It will be appreciated that while the upper and lower frame sections 130 a , 130 b have been described as being comprised of a plurality of discrete components, in the illustrated embodiment, the upper frame section 130 a and the lower frame section 130 b are comprised of a single uniform component preferably formed of extruded or molded aluminum.
[0038] The pivoting members 140 are positioned on the inner surface 142 of the L-shaped section 132 so that the pivoting member 140 is positioned within the opening 116 of the window frame 114 . The pivoting sections 127 and 128 of the retaining members 122 and 124 define an opening 141 that receives the pivoting member 140 to permit the pivoting movement of the retaining members 122 and 124 . More particularly, the pivoting member 140 defines a ball 143 at its distal end that extends outwardly towards the outer surface of the window frame 114 . Since the pivoting member 140 is positioned on the inside surface of the L-shaped section 132 of the frame 114 , access to the interconnection between the retaining members 122 and 124 and the pivoting members is inhibited. Moreover, an end portion 145 of each of the retaining members 122 , 124 is adapted to be flushly positioned within a recess 147 (FIGS. 3A and 3B) when the retaining members 122 , 124 are in the closed position so that access to the interconnection between the retaining members 122 , 124 is further inhibited. In this way, the likelihood of a person prying the retaining members 122 , 124 free from the pivoting members 140 and thereby dismantling or damaging the window protector assembly 112 is inhibited.
[0039] As is illustrated in FIGS. 3A and 3B, the first retaining member 122 and the second retaining member 124 can be pivoted about the pivoting members 140 so as to extend outward from the opening 116 . This allows a protective sacrificial sheet 156 to be positioned within the opening 116 on the seal 146 . Subsequently, one or more pieces of glazing 120 can be positioned on an inner surface 160 of the protective sheet 156 in the manner shown in FIGS. 3A and 3B. Subsequently, an inner sacrificial protective sheet 162 can be positioned on an inner surface 164 of the glazing 120 . The first and second retaining members 122 , 124 can then be pivoted into the closed position as shown in FIG. 3B. The first and second retaining members 122 , 124 further include an inner seal 166 which extends entirely around the perimeter of the opening 116 so that the inner seal 166 makes contact with the inner sacrificial protective sheet 162 in the manner shown in FIG. 3B.
[0040] [0040]FIG. 4 is a cross-sectional view which illustrates the side frame sections 170 a , 170 b of the frame 114 . The side frame sections 170 a , 170 b are integrally connected to the upper and lower frame sections 130 a , 130 b so that the entire frame 114 is a single integral piece. The side frame sections 170 a , 170 b are also configured to have an L-shaped section 172 that has a side wall member 174 that is adapted to be flushly positioned against the outer side wall 110 of the vehicle 100 adjacent the window opening 106 . The L-shaped section 172 also has a laterally extending section 176 that extends inward through the opening 116 of the frame 114 in the same manner as the laterally extending section 136 of the upper and lower frame sections 130 a , 130 b as described above. A bracing member 180 extends inwardly into the opening 116 of the frame 114 so as to provide a bracing contact so that the first and second retaining members 122 , 124 will be positioned adjacent the bracing member 180 when the retaining members 122 , 124 are in the closed position. As is also illustrated in FIG. 4, the side frame sections 170 a , 170 b include a seating member 184 that extends inward into the opening 116 from the inner surface 182 of the laterally extending section 176 . The seating member 184 is adapted to receive one or more seals 186 that extend laterally around the perimeter of the window.
[0041] As illustrated in FIGS. 3A and 4, the protective sacrificial sheet 156 is positioned adjacent a seal 186 which is retained in the side frame members 170 a , 170 b in substantially the same manner as discussed above in connection with the seal 146 and the upper and lower frame members 130 a , 130 b . The glazing 120 is then positioned adjacent the outer sacrificial layer 156 and the inner protective sheet 162 is then positioned adjacent the inner surface 164 of the glazing 120 in the same manner as described above in connection with FIGS. 3A and 3B. As illustrated in FIG. 4, when the first and second pivoting retaining members 122 , 124 are in the closed position, the one or more seals 166 , are positioned adjacent the inner sacrificial protective sheet 162 . In one embodiment, the window 110 is square in which case the seals are comprised of a plurality of pieces. In another embodiment, the window 110 is curved and the seals comprise a single seal.
[0042] As is shown in FIGS. 2, 5A and 5 B, the frame 114 is comprised of a single uniform piece that is comprised of the upper and lower sections 130 a , 130 b and the side sections 170 a , 170 b . The retaining members 122 , 124 are pivotally attached and define retaining surfaces that extend about the outer perimeter of the opening 116 defined by the frame 114 so as to overlap the outer perimeter of the glazing 120 and the protective sheets 156 , 162 . The seating member 144 of the upper and lower frame sections 130 a , 130 b and the seating member 184 of the side frame sections 170 a , 170 b also extend into the opening 116 defined by the frame 114 so that the protective sheets 156 , 162 and the glazing 120 can be securely retained in the opening 116 of the frame 114 by the retaining members 122 , 124 pressing the protective sheets 156 , 162 and the glazing 120 against the seating members 144 , 184 about substantially the entire perimeter of the glazing 120 and the protective sheets 156 , 162 .
[0043] [0043]FIGS. 5A and 5B further illustrate the configuration and operation of the window protector assembly 112 . In particular, as illustrated in FIG. 5A, the first and second retaining members 122 , 124 are pivotable with respect to the upper and lower frame sections 130 a and 130 b thereby removing the first and second retaining members 122 , 124 from the outer perimeter of the outer sacrificial layer 156 , the glazing 120 , and the inner sacrificial layer 162 . This allows each of these layers to be lifted out of the opening 116 defined by the frame 114 .
[0044] As shown in FIG. 5B, when the first and second retaining members 122 , 124 are closed, they are positioned about the outer perimeter of the outer protective layer 156 , the glazing 120 and the inner protective layer 162 thereby capturing these three layers adjacent the seal positioned on the inner sections of the frame 114 . As the outer perimeter of the sacrificial protective layers 156 , 162 and the glazing 120 is covered by the pivoting retaining members 122 , 124 , these layers cannot be removed without moving the first and second retaining members 122 , 124 into the open position illustrated in FIGS. 3A and 5A. In this embodiment, the sacrificial protective layers 156 and 162 are comprised of an acrylic material that is adapted to be positioned adjacent the exposed surfaces of the glazing 120 such that the exposed surfaces of the glazing 120 on both the inside and the outside of the window is covered by the protective layers 156 , 162 . In this way, damage to the more expensive glazing 120 as a result of vandalism or defacement is inhibited as the protective acrylic layers provide protection against such damage.
[0045] [0045]FIGS. 6A and 6B illustrate an alternate embodiment of the retaining members and their attachment to the frame of the window frame assembly. In particular, FIGS. 6A and 6B illustrate an alternate embodiment of the portions 127 , 128 of the retaining members 122 , 124 that pivotally attach the retaining members to the window frame. Specifically, in this embodiment, a retaining member 214 has a ball 216 formed on a first end that is adapted to be positioned within a recess 218 formed on an L-shaped section 232 of the frame. The embodiment of FIG. 6A and 6B is substantially similar to the embodiment of FIG. 3A and 3B except that the retaining members in this embodiment have the rotatable ball formed thereon and the recess is formed in the L-shaped section 232 of the frame as opposed to the other way around as described above in connection with FIGS. 3A and 3B.
[0046] As is also illustrated in FIG. 6A and 6B, the retaining member has a seal portion 220 that receives a seal 222 . The ball portion 216 is rotatable within the recess 218 between an open and a closed position. In the closed position, the radius of the ball 216 prevents removal of the retaining member 214 from the recess 218 . However, the ball 218 has a flat surface 223 that decreases the radius of the ball 216 with respect to the opening of the recess 218 when the retaining member 214 has been moved to the open position as shown in FIG. 6A. Hence, the retaining member can be fully removed from engagement with the frame thereby permitting easy removal and installation of the retaining members.
[0047] When the retaining members are in the closed position, a securing mechanism, such as the mechanism illustrated in FIGS. 7 and 8 hereinafter can be used to secure the retaining members in the closed position. In the closed position, the seal 222 engages with the inner protective sheet 156 so as to secure the protective sheets and glazing within the window frame in substantially the same manner as described above.
[0048] [0048]FIG. 7 illustrates a securing mechanism 191 that is adapted to secure the first and second retaining members 122 , 124 in a locked and closed position. In particular, as illustrated in FIGS. 3A and 3B, the outer edge of the arms 123 a , 123 b of the first retaining member 122 and outer edge of the arms 125 a , 125 b of the second retaining member 124 are beveled so that the outer tip 183 of the arms 125 a , 125 b of the second retaining member 124 is positioned over the outer tip 185 of the arms 123 a , 123 b of the first retaining member 122 when the first and second retaining members are positioned in the closed position in the manner shown in FIGS. 3B and 5B. A securing member 190 is positioned within an opening 192 in both the arms 125 a , 125 b of the second retaining member 124 . Preferably, the securing member 190 is pivotable within the opening 192 such that a laterally extending arm 194 of the securing member 190 can be positioned within an opening 196 formed in a side wall of the frame 114 .
[0049] In this embodiment, the opening 196 is preferably formed in the bracing member 180 and has a curved opening to permit the extending arm 194 to be rotated into the opening 196 in response to the user turning the securing member 190 . As illustrated in FIG. 8, the securing member 190 is preferably pivotable between an opened position and a closed position wherein the laterally extending member 194 is positioned within the opening 196 and the frame 114 in the closed position and is retracted from the opening 196 in the opened position.
[0050] As is also illustrated in FIG. 8, the outer face 200 of the securing member 190 includes a tool recess 202 that is adapted to receive only a specially configured tool (not shown) such that manipulation of the securing member 190 between the opened and closed positions can preferably only be accomplished by an authorized person possessing a specially configured tool. As is illustrated in FIG. 2, there are preferably two securing members 190 positioned in both of the outer ends of the arms 125 a , 125 b of the second retaining member 124 to secure the second retaining member 124 in the closed position adjacent the frame 114 . As discussed above, because the outer end 183 of the second retaining member 124 overlaps the outer end 185 of the first retaining member 122 , securing the second retaining member 124 in the closed position against the frame 114 in the manner shown in connection with FIGS. 7 and 8 results in the first retaining member 122 similarly being secured in the closed position.
[0051] Advantageously, it is simple to remove and replace the inner sacrificial layer 162 and the outer sacrificial layer 156 and the glazing 120 by simply manipulating the retaining members 122 , 124 into the open position and extracting each of the layers positioned within the opening 116 of the frame 114 . Hence, the window protector assembly 112 of the illustrated embodiment allows for simpler and easier replacement of the protective layers 156 , 162 and the glazing 120 as compared to similar protective devices of the prior art. As a result of permitting such easy access and replacement, it is now possible to have a protective layer positioned on the outer surface of the glazing 120 in addition to a protective surface on the inner surface of the glazing 120 . However, it will also be appreciated that the window frame and protector 112 of the present invention can be used with only an inner protective layer 162 without departing from the spirit of the present invention.
[0052] Hence, the window protector 112 of the present invention allows for easier replacement of protective sheets as compared to window protective devices of the prior art. This easier access facilitates the use of a protective layer on the outside surface of the glazing as replacement of this sheet is now simplified due to the ease of access provided by the window protector assembly of the preferred embodiment.
[0053] [0053]FIG. 9 illustrates another embodiment of an exemplary public transportation vehicle 300 that incorporates windows 302 having window frames 314 mounted within openings 306 in the side wall 310 of the vehicle 300 . It will be appreciated from the following discussion that, while the window protector assembly of this embodiment is described in connection with a bus, that the window protector assembly 312 can be used in a number of different applications. These applications include other types of public transportation vehicles and also windows that are positioned in fixed environments, such as buildings, where the window is likely to be accidentally or intentionally damaged or defaced. As will also be apparent from the following discussion, the window protector assembly of the preferred embodiment is designed to both protect the glazing of the window and also to facilitate rapid change and replacement of protective sheets and the glazing of the window protector assembly.
[0054] [0054]FIG. 10 illustrates one embodiment of a window protector assembly 312 . In this embodiment, the window protector assembly 312 incorporates a frame 314 that is adapted to mount within the opening 306 in the side wall 310 of the vehicle 300 in a well-known manner. The frame 314 defines an opening 316 into which one or more pieces of glazing 320 are to be positioned.
[0055] In this embodiment, a first retaining member 322 and a second retaining member 324 are pivotally mounted to the frame 314 so as to be positioned about the outer perimeter of the opening 316 in the frame 314 . As is shown in FIG. 10, the first retaining member 322 is generally U-shaped having two arms 323 a , 323 b that extend along the side walls of the frame 314 and pivoting section 327 . Similarly, the second retaining member 324 is also generally U-shaped having a pivoting section 328 and two arms 325 a , 325 b that also extend along the side walls of the frame 314 so as to engage with the two arms 323 a , 323 b of the first retaining member 322 . The engagement between the arms 323 a , 323 b of the first retaining member 322 and the arms 325 a , 325 b of the second retaining member 324 secures the glazing and protective layers within the opening 316 of the frame 314 in a manner that will be described in greater detail below.
[0056] As will also be described in greater detail below in reference to FIGS. 13A and 13B, the pivoting section 327 of the first retaining member 322 and the pivoting section 328 of the second retaining member 324 are pivotally attached to the frame 314 so as to be pivotable between a closed position, as shown in FIGS. 10 and 12, and an opened position, as shown in FIG. 11A.
[0057] As is illustrated in FIG. 10 and 11 B, the retaining members 322 , 324 open outward of the window so as to secure the glazing in the window frame. When the glazing is to be replaced, the retaining members 322 , 324 are opened and the glazing is then removed towards the outside of the vehicle in the manner that will be described in greater detail hereinbelow, thereby greatly simplifying the replacement of damaged or defaced glazing.
[0058] As is shown in FIG. 10, when the retaining members 322 , 324 are in a closed position, the retaining members 322 , 324 cover the outer perimeter of the glazing 320 and any outer protective member. This is because the arms and pivoting sections of the retaining members 322 , 324 are selected to have a width sufficient so as to fully cover the outer edge of the glazing 320 and any outer protective layers positioned within the opening 316 of the frame 314 . As is shown in FIG. 12, when the retaining members 322 , 324 are in an open position, the outer perimeter of the glazing 320 and any outer protective layer is exposed. With the outer perimeter of the glazing 320 exposed, the glazing 320 can be removed from the frame via the exterior surface of the vehicle in a known manner.
[0059] [0059]FIGS. 11A and 11B illustrate the interconnection between the first retaining member 322 and the second retaining member 324 and corresponding sections of the frame 314 . In particular, as illustrated in FIGS. 11A and 11B, the frame 314 includes an upper frame section 330 a and a lower frame section 330 b . The upper and lower frame sections 330 a , 330 b have an L-shaped section 332 that is suitable for mounting in the opening 306 of the side wall 310 of the vehicle 300 . In particular, the L-shaped section 332 has an exterior lip 334 that is adapted to mount flush against the outer surface of the side wall 310 of the vehicle adjacent the window openings 306 . The L-shaped section 332 further includes a laterally extending member 336 that is adapted to be positioned adjacent the inner walls of the openings 306 in the side walls 310 of the vehicle so as to extend substantially through the opening 306 .
[0060] A pivoting member 340 is formed on an inner wall 342 of the laterally extending member 336 so as to extend perpendicularly outward therefrom into the opening 316 defined by the frame 314 . As will be described in greater detail below, the pivoting member 340 extends the full length of the upper frame section 330 a and the lower frame section 330 b , and provides a surface to which the pivoting section 327 of the first retaining member 322 and the pivoting section 328 of the second retaining member 324 can be respectively attached to the frame 314 of the window protector assembly 312 .
[0061] The L-shaped section 332 also defines a seating member 344 that extends inward into the opening 316 defined by the window frame 314 . The seating member 344 is adapted to receive a seal 346 that is retained in the seating member 344 as a result of a deformable section 350 of the seal 346 being positioned within an opening 352 formed in the seating member 344 of the upper and lower frame members 330 a , 330 b . Hence, the seal 346 is press-fit within the seating member 344 of the upper frame section 330 a and the lower frame section 330 b . The glazing 320 is preferably positioned within frame 314 so as to be positioned adjacent the seal 346 . When the retainers 322 , 324 are closed, the glazing 320 is compressed against the seal 346 such that the glazing seals the window so as to inhibit the entry of moisture or air from the outside environment into the interior of the vehicle. It will be appreciated that while the upper and lower frame sections 330 a , 330 b have been described as being comprised of a plurality of discrete components, in the illustrated embodiment, the upper frame section 330 a and the lower frame section 330 b are comprised of a single uniform component preferably formed of extruded or molded aluminum.
[0062] The pivoting members 340 are positioned on the inner surface 342 of the L-shaped section 332 so that the pivoting member 340 is positioned within the opening 316 of the window frame 314 . The pivoting sections 327 and 328 of the retaining members 322 and 324 define an opening 341 that receives the pivoting member 340 to permit the pivoting movement of the retaining members 322 and 324 . More particularly, the pivoting member 340 defines a ball 343 at its distal end that extends outwardly toward the center of the window 302 . Since the pivoting member 340 is positioned on the inside surface of the Lshaped section 332 of the frame 314 , access to the interconnection between the retaining members 322 and 324 and the pivoting member 340 is inhibited. Moreover, an end portion 345 of each of the retaining members 322 , 324 is adapted to be flushly positioned within a recess 347 (FIGS. 11A and 11B) when the retaining members 322 , 324 are in the closed position so that access to the interconnection between the retaining members 322 , 324 is further inhibited. In this way, the likelihood of a person prying the retaining members 322 , 324 free from the pivoting member 340 and thereby dismantling or damaging the window protector assembly 312 is inhibited.
[0063] As is illustrated in FIGS. 11A and 11B, the first retaining member 322 and the second retaining member 324 can be pivoted about the pivoting members 340 so as to extend outward from the opening 316 . This allows one or more pieces of glazing 320 to be positioned within the opening 316 on the seal 346 . Subsequently, an outer sacrificial protective sheet 362 can be positioned on an outer surface 364 of the glazing 320 . The first and second retaining members 322 , 324 can then be pivoted into the closed position as shown in FIG. 11B. The first and second retaining members 322 , 324 further include an inner seal 366 which extends entirely around the perimeter of the opening 316 so that the inner seal 366 makes contact with the outer sacrificial protective sheet 362 . Once contact is made between the seal 366 and the outer sacrificial protective sheet 362 , the outer sacrificial protective sheet 362 in turn contacts the glazing 320 which contacts the seal 346 which is rigidly attached to the rest of the frame 314 . Thus, by closing the retaining members 322 , 324 , the outer sacrificial protective sheet 362 and the glazing 320 are held rigidly inside the frame 314 . However, it will be appreciated that both the outer sacrificial protective sheet 362 and the glazing are easily removable once the retaining members 322 , 324 are opened.
[0064] Advantageously, because the retaining members 322 , 324 open only to the outside of the vehicle, passengers would be unable to open the retaining members 322 , 324 . This significantly reduces the abilities of a vandal to dismantle or damage the window protector assembly 312 from the inside of the vehicle, where vandalism is most likely to occur. Furthermore, passengers would be unable to open the retaining members 322 , 324 to gain access to the fragile and expensive glazing 320 . Hence, because the retaining members 322 , 324 open only to the outside, the cost of repairing the effects of vandalism is decreased while the safety of the other passengers is increased.
[0065] Furthermore, as illustrated in FIGS. 11A and 11B, the upper and lower frame sections 330 a , 330 b include an upper and lower flange 355 a , 355 b that extends toward the center of the opening 316 defined by the window frame 314 . The upper and lower flanges 355 a , 355 b are positioned on the interior surface of the window frame 314 , lying parallel to the seating member 344 and to the plane of the glazing 320 . The upper and lower flanges 355 a , 355 b are separated from the seating member 344 by a distance 360 so as to define an upper and lower recess 359 a , 359 b.
[0066] In the preferred embodiment of the window protector assembly 312 , an inner sacrificial protective sheet 356 resides in the upper and lower recesses 359 a , 359 b . To install the inner sacrificial sheet 356 , the inner sacrificial protective sheet 356 should be flexible enough such that the edges of the inner sacrificial protective sheet 356 can be bent over the upper and lower flanges 355 a , 355 b and into the upper and lower recesses 359 a , 359 b without breaking.
[0067] In one embodiment, a gasket 351 is positioned on the bottom surface 357 inside the lower recess 359 b . Preferably, the gasket 351 is of such a thickness that it centers the inner sacrificial protective sheet 356 inside the window protector assembly 312 . Also in this embodiment, one or more retainer fasteners 353 are drilled perpendicularly through the upper flange 355 a , at a location above the upper edge 349 a of the inner sacrificial protective sheet 356 . Preferably, the retainer fasteners 353 lie close enough to the upper edge 349 a such that the retainer bolts 353 prevent the inner sacrificial protective sheet 356 from shifting inside the recess 359 . Also in the preferred embodiment, the fasteners 353 are removable only with a special tool such that a passenger would not be able to remove the fasteners 353 easily.
[0068] Preferably, the distance measured between a lower edge 349 b of the inner sacrificial protective sheet 356 to the top of the lower flange 355 b is less than the distance measured between an upper edge 349 a of the inner sacrificial protective sheet 356 to the base of the upper flange 355 a . Thus, after the retainer fasteners 353 are removed, the inner sacrificial protective sheet 356 can be shifted upwards until the lower edge 349 b of the inner sacrificial protective sheet 356 is exposed. Then, in order to remove the inner sacrificial protective sheet 356 from the window protection assembly 312 , the lower edge 349 b could be grasped in order to bend the inner sacrificial protective sheet 356 out of the upper and lower recesses 359 a , 359 b . Advantageously, this embodiment of the widow protector assembly 312 allows for quick installation and removal of the inner sacrificial protective sheet 356 , yet the addition of the fasteners 353 prevents a passenger from shifting and removing the protective sheet 356 .
[0069] [0069]FIG. 12 is a cross-sectional view illustrating the side frame sections 370 a , 370 b of the frame 314 . The side frame sections 370 a , 370 b are integrally connected to the upper and lower frame sections 330 a , 330 b so that the entire frame 314 is a single integral piece. The side frame sections 370 a , 370 b are configured to have an L-shaped section 372 that has a side wall member 374 that is adapted to be flushly positioned against the outer side wall 310 of the vehicle 300 adjacent the window opening 306 . The L-shaped section 372 also has a laterally extending section 376 that extends inward through the opening 316 of the frame 314 in the same manner as the laterally extending section 336 of the upper and lower frame sections 330 a , 330 b as described above. As is also illustrated in FIG. 12, the side frame sections 370 a , 370 b include a seating member 384 that extends inward into the opening 316 from the inner surface 382 of the laterally extending section 376 . The seating member 384 is adapted to receive one or more seals 386 that extend laterally around the perimeter of the window. Finally, as illustrated in FIG. 12, the side frame sections 370 a , 370 b include a flange 378 that extends inward into the opening 316 from the inner surface 382 of the laterally extending section 376 . The flange 378 extends parallel to the seating member 384 , and the flange 378 and the seating member 384 are separated at a distance 379 to define a recess 375 .
[0070] As illustrated in FIGS. 11A and 12, the glazing 320 is positioned adjacent a seal 386 which is retained in the side frame members 370 a , 370 b in substantially the same manner as discussed above in connection with the seal 346 and the upper and lower frame members 330 a , 330 b . The outer sacrificial layer 362 is then positioned adjacent the glazing 320 in the same manner as described above in connection with FIGS. 11A and 11B. As illustrated in FIG. 12, when the first and second pivoting retaining members 322 , 324 are in the closed position, the one or more seals 366 , are positioned adjacent the outer sacrificial protective sheet 362 . In one embodiment, the window 310 is square in which case the seals are comprised of a plurality of pieces. In another embodiment, the window 310 is curved and the seals comprise a single seal.
[0071] Also as illustrated in FIGS. 11A and 12, the inner sacrificial protective sheet 356 is positioned inside the recess 375 in the same manner as described above in connection with the upper and lower recesses 359 a , 359 b . In addition, a gasket 377 resides inside the recess 375 in order to center the inner sacrificial protective sheet 356 in the window protector assembly 312 .
[0072] As is shown in FIGS. 10, 13A and 13 B, the frame 314 is comprised of a single uniform piece that is comprised of the upper and lower sections 330 a , 330 b and the side sections 370 a , 370 b . The retaining members 322 , 324 are pivotally attached and define retaining surfaces that extend about the outer perimeter of the opening 316 defined by the frame 314 so as to overlap the outer perimeter of the glazing 320 and the outer protective sheet 362 . The seating member 344 of the upper and lower frame sections 330 a , 330 b and the seating member 384 of the side frame sections 370 a , 370 b also extend into the opening 316 defined by the frame 314 so that the outer protective sheet 362 and the glazing 320 can be securely retained in the opening 316 of the frame 314 by the retaining members 322 , 324 pressing the outer protective sheet 362 and the glazing 320 against the seating members 344 , 384 about substantially the entire perimeter of the glazing 320 and the protective sheet 362 .
[0073] [0073]FIGS. 13A and 13B further illustrate the configuration and operation of the window protector assembly 312 . In particular, as illustrated in FIG. 13A, the first and second retaining members 322 , 324 are pivotable with respect to the upper and lower frame sections 330 a and 330 b thereby removing the first and second retaining members 322 , 324 from the outer perimeter of the outer sacrificial layer 362 and the glazing 320 . This allows each of these layers to be lifted out of the opening 316 defined by the frame 314 .
[0074] As shown in FIG. 13B, when the first and second retaining members 322 , 324 are closed, they are positioned about the outer perimeter of the outer protective layer 362 and the glazing 320 thereby capturing these two layers adjacent the seal positioned on the inner sections of the frame 314 . As the outer perimeter of the sacrificial protective layer 362 and the glazing 320 is covered by the pivoting retaining members 322 , 324 , these layers cannot be removed without moving the first and second retaining members 322 , 324 into the open position illustrated in FIGS. 11A and 13.
[0075] In this embodiment, the sacrificial protective layers 356 and 362 are comprised of an acrylic material that is adapted to be positioned adjacent the exposed surfaces of the glazing 320 such that the exposed surfaces of the glazing 320 on both the inside and the outside of the window is covered by the protective layers 356 , 362 . In this way, damage to the more expensive glazing 320 as a result of vandalism or accident is inhibited as the protective acrylic layers provide protection against such damage.
[0076] It should be noted that the alternate embodiment of the retaining members and their attachment to the frame described supra and illustrated in FIGS. 6A and 6B can be fully incorporated into this alternate embodiment of the window protector assembly 312 .
[0077] [0077]FIG. 14 illustrates a securing mechanism 391 that is adapted to secure the first and second retaining members 322 , 324 in a locked and closed position. In particular, as illustrated in FIGS. 11A and 11B, the outer edge of the arms 323 a , 323 b of the first retaining member 322 and outer edge of the arms 325 a , 325 b of the second retaining member 324 are beveled so that the outer tip 383 of the arms 325 a , 325 b of the second retaining member 324 is positioned over the outer tip 385 of the arms 323 a , 323 b of the first retaining member 322 when the first and second retaining members are positioned in the closed position in the manner shown in FIGS. 11 and 13. A securing member 390 is positioned within an opening 392 in both the arms 325 a , 325 b of the second retaining member 324 . Preferably, the securing member 390 is pivotable within the opening 392 such that a laterally extending arm 394 of the securing member 390 can be positioned within an opening 396 formed in a side wall of the frame 314 .
[0078] In this embodiment, the opening 396 is preferably formed in the bracing member 380 and has a curved opening to permit the extending arm 394 to be rotated into the opening 396 in response to the user turning the securing member 390 . As illustrated in FIG. 15, the securing member 390 is preferably pivotable between an opened position and a closed position wherein the laterally extending member 394 is positioned within the opening 396 and the frame 314 in the closed position and is retracted from the opening 396 in the opened position.
[0079] As is also illustrated in FIG. 15, the outer face 400 of the securing member 390 includes a tool recess 402 that is adapted to receive only a specially configured tool (not shown) such that manipulation of the securing member 390 between the opened and closed positions can preferably only be accomplished by an authorized person possessing a specially configured tool. As is illustrated in FIG. 10, there are preferably two securing members 390 positioned in both of the outer ends of the arms 325 a , 325 b of the second retaining member 324 to secure the second retaining member 324 in the closed position adjacent the frame 314 . As discussed above, because the outer end 383 of the second retaining member 324 overlaps the outer end 385 of the first retaining member 322 , securing the second retaining member 324 in the closed position against the frame 314 in the manner shown in connection with FIGS. 14 and 15 results in the first retaining member 322 similarly being secured in the closed position.
[0080] Advantageously, it is simple to remove and replace the outer sacrificial layer 362 and the glazing 320 by simply manipulating the retaining members 322 , 324 into the open position and extracting each of the layers positioned within the opening 316 of the frame 314 . Likewise, it is simple to remove and replace the inner sacrificial layer 356 by shifting the sacrificial layer 356 until its edge 349 b is exposed and then grasping the edge 349 b and pulling on it until the sacrificial layer 356 bends out of the recesses 359 a , 359 b , 375 . Hence, the window protector assembly 312 of the illustrated embodiment allows for simpler and easier replacement of the protective layers 356 , 362 and the glazing 320 as compared to similar protective devices of the prior art. As a result of permitting such easy access and replacement, it is now possible to have a protective layer positioned on the outer surface of the glazing 320 in addition to a protective surface on the inner surface of the glazing 320 . However, it will also be appreciated that the window frame and protector 312 of the present invention can be used with only an inner protective layer 356 without departing from the spirit of the present invention.
[0081] Hence, the window protector 312 of the present invention allows for easier replacement of protective sheets as compared to window protective devices of the prior art. This easier access facilitates the use of a protective layer on the outside surface of the glazing as replacement of this sheet is now simplified due to the ease of access provided by the window protector assembly of the preferred embodiment.
[0082] Although the illustrated embodiments of the present invention have shown, described and pointed out the fundamental novel features of the invention, as applied to these embodiments, it will be understood that various omissions, substitutions and changes in the form of the detail of the device illustrated may be made by those skilled in the art without departing from the spirit of the present invention. Consequently, the scope of the invention should not be limited to the foregoing description, but should be defined by the appended claims.
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A window protector assembly that protects both the inside and outside of standard panes of glazing from vandalism or other damage. The assembly comprises a pane of glazing, a sheet of protective material on the inside and outside of the glazing, and a frame. The frame pivots on the outer side of the glazing for quick loading and unloading of the glazing and the protective sheet on the outside of the glazing, and the frame also pivots closed to seal the glazing and protective sheets securely within the window protector assembly. The frame also comprises a recess wherein the protective sheet on the inside of the glazing is positioned.
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CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation-in-part application of Petitioners' earlier application Ser. No. 10/103,308 filed Mar. 20, 2002, entitled “CONCRETE RAILROAD GRADE CROSSING PANELS”.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an improved concrete railroad grade crossing and more particularly to an improved railroad grade crossing comprising concrete gauge panels which extend between the rails and further comprising concrete approach or field panels which extend between each rail and the roadway. Even more particularly, the invention relates to improved elastomeric gauge seals which are partially embedded in the sides of the gauge panels and relates to improved elastomeric approach or field seals which are partially embedded in the inner ends of the approach or field panels.
2. Description of the Prior Art
Frequently, a railroad track crosses a roadway which necessitates that the space between the rails be filled with a material which brings that space up to grade. It is also necessary to bring the approaches on either side of the rails up to grade. In the past, precast concrete panels, or gauge panels, have been positioned between the rails and precast concrete panels, or approach panels, have been positioned on the approach sides of the track. The prior art railroad grade crossings have also used elastomeric seals on the sides of the concrete gauge panels to fill the space between the gauge panels and the rails to prevent foreign materials from entering and filling the space between the gauge panels and the rail. The prior art railroad grade crossings have also used elastomeric seals on the inner ends of the concrete approach panels to prevent foreign materials from entering and filling the space between the approach panel and the associated rail. In some cases, the upper inner ends of the approach panels and the upper outer ends of the gauge panels were chamfered or beveled to prevent portions of the concrete approach panels and gauge panels from chipping off and filling the spaces between the panels and the rails. In other cases, angle irons have been used as edge protectors to prevent the chipping problem.
In later years, the gauge seals and approach seals have been partially embedded in the concrete panels to aid in attaching the seals to the panels. However, even where the seals are partially embedded in the prior art concrete panels, it is believed that the prior art devices experience some attachment problems of the seals. Applicants' co-pending application is believed to solve at least some of the attachment problems. The instant invention is believed to represent a further advance in the art.
SUMMARY OF THE INVENTION
A railroad grade crossing for extending a roadway across a pair of parallel spaced-apart rails is disclosed. The railroad grade crossing includes one or more concrete gauge panels which extend substantially between the rails. Each of the gauge panels has a top surface which is substantially coplanar with the roadway with the bottom surface of the gauge panel being supported upon the ties. Each of the gauge panels has an elastomeric gauge seal on each side thereof which are positioned adjacent the rails. The upper ends of the gauge seals are positioned downwardly from the top surface of the gauge panel with the upper ends of the gauge seals having arcuate recessed portions formed therein adjacent the outer ends thereof. The lower inner ends of the gauge seals are at least partially embedded in the outer ends of the gauge panels. Concrete approach panels or field panels are positioned between each rail and the roadway associated therewith. Each of the concrete approach panels has a top surface which is substantially coplanar with the roadway and a bottom surface which is supported upon the ties. The approach panels have elastomeric approach seals at their inner ends thereof with the upper ends of the approach seals being positioned downwardly from the top surface of the approach panels. The lower inner ends of the approach seals are at least partially embedded in the inner ends of the approach panels. Elongated, metal angle members (edge protectors) are cast in the upper outer edges of the gauge panels and the upper inner edges of the approach panels. Two embodiments of the gauge panel seals and two embodiments of the approach panel seals are disclosed.
It is therefore a principal object of the invention to provide an improved concrete railroad grade crossing.
A further object of the invention is to provide an improved concrete railroad grade crossing comprising concrete gauge panels and concrete approach panels wherein elastomeric seals are partially embedded in the panels and extend therefrom so as to be positioned adjacent the rails.
Still another object of the invention is to provide an improved concrete railroad grade crossing including elastomeric gauge seals and approach seals which have voids formed therein so as to reduce the amount of elastomeric material required to construct the same.
Still another object of the invention is to provide an improved concrete railroad grade crossing including concrete gauge and approach panels which have elastomeric seals partially embedded therein.
Still another object of the invention is to provide an improved method of attaching elastomeric gauge and approach seals to gauge panels and approach panels, respectively.
Still another object of the invention is to provide an improved railroad crossing which has greater durability than the railroad grade crossings of the prior art.
These and other objects will be apparent to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial top plan view of the concrete railroad grade crossing of this invention;
FIG. 2 is a partial vertical sectional view of one of the embodiments of the concrete railroad grade crossing of this invention;
FIG. 3 is a partial perspective view of one of the approach panel seals of the embodiment of FIG. 2;
FIG. 4 is a partial perspective view of the gauge panel seal of the embodiment of FIG. 2;
FIG. 5 is a partial vertical sectional view of a second embodiment of the concrete railroad grade crossing of this invention; and
FIG. 6 is a partial vertical sectional view of a third embodiment of the concrete railroad grade crossing of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the drawings, the numeral 10 refers to a railroad track including rails 12 and 14 which are supported upon a plurality of spaced-apart ties 16 by means of tie plates 18 which are secured to the ties 16 in conventional fashion such as by spikes, clips or bolts. In many cases, the railroad track 10 must cross a roadway which is generally referred to by the reference numeral 20 .
Normally, a plurality of precast concrete approach panels 22 will be positioned between the roadway 20 and the rails 12 and 14 with the approach panels 22 being supported upon the outer ends of the ties 16 . Normally, the approach panels 22 will be positioned between the roadway 20 and one of the rails in an end-to-end fashion, the number of which will depend upon the width of the roadway and the length of the approach panels. The numeral 24 refers to precast concrete gauge panels which are positioned between the rails 12 and 14 and which are supported upon the ties 16 . The gauge panels 24 are supported upon the ties 16 in an end-to-end fashion, the number of which will depend upon the width of the roadway and the length of the gauge panels.
Each of the approach or field panels 22 is comprised of a precast concrete material and includes top surface 26 , bottom surface 28 , and opposite sides 30 and 32 . Approach panel 22 is provided with a recessed portion 34 formed therein at each of the opposite sides thereof to provide a clearance space for the spikes, bolts, clips, etc., which secure the tie plates 18 to the ties 16 and which secure the rail to the tie plate 18 in conventional fashion.
An elongated, metal angle member 38 (edge protector) is cast in the approach panel 22 at the upper inner side thereof, as illustrated in the drawings, and which is held in place in the concrete by horizontally disposed and horizontally spaced rods or bars 40 secured thereto. The angle member 38 is also held in place by a plurality of vertically disposed and horizontally spaced retainers 41 secured thereto having enlarged head portions 41 a at their lower ends. As will be explained in more detail hereinafter, an approach seal 42 is secured to the inner end of each of the approach panels 22 .
Each of the gauge panels 24 is comprised of a precast concrete material and includes top surface 44 , bottom surface 46 , and opposite sides 48 and 50 . Gauge panel 24 is provided with a recessed portion 52 at side 48 and is provided with a recessed portion 54 at its side 50 , as seen in FIG. 2, to provide a clearance space for the spikes, bolts, clips, etc., which secure the tie plates 18 to the ties 16 and which secure the rails to the tie plates 18 in conventional fashion.
Elongated, metal angle members (edge protectors) 56 and 58 are cast in the gauge panel 24 at the upper outer sides thereof, as illustrated in the drawings, and which are held in place by horizontally disposed and horizontally spaced rods or bars 60 secured thereto. The angle members 56 and 58 are also held in place by a plurality of vertically disposed and horizontally spaced retainers 61 secured thereto having enlarged head portions 61 a at their lower ends. As will be explained in more detail hereinafter, gauge seals 62 and 64 are secured to the outer sides of each of the gauge panels 24 . Inasmuch as gauge seals 62 and 64 are identical, only gauge seal 62 will be described in detail.
As seen in FIG. 3, approach seal 42 is comprised of an elastomeric material generally having an outer end 66 and an inner end 68 . The upper end 70 of approach seal 42 is ribbed, as illustrated in FIG. 3, with upper end 70 being positioned below the top surface of the panel 22 and below the upper end of the associated rail. Elongated voids 71 , 72 , 73 , 74 and 75 are formed in the approach seal 42 to reduce the amount of material required to fabricate the approach seal. The inner end 66 of approach seal 42 has a lobe or nose 76 extending therefrom which is embedded in the concrete of the panel 22 . Lobe 76 defines a recessed area 78 having concrete therein to further aid in securing the approach seal 42 to the panel 22 . Recessed area 78 is defined by the vertical face 76 a of approach seal 42 and the inclined face 76 b . Lobe 76 also defines a lower surface 76 c having concrete positioned therebelow to further aid in attaching the approach seal 42 to the panel 22 . The concrete which is positioned in the recessed area 78 outwardly of lobe 76 assists in preventing separation of approach seal 42 from panel 22 . As seen in FIG. 2, the lower end of angle member 38 is partially received (not embedded) in recessed area 78 . As seen in FIG. 3, the lower end of approach seal 42 is tapered upwardly and outwardly at 82 and terminates at a downwardly extending rib 84 . The outer end of the approach seal 42 is arcuate in shape, as best seen in FIG. 3, to provide an arcuate surface 86 which is in contact with the arcuate shape of the rail below the head of the associated rail. The engagement of the outer end of the upper end 70 of the approach seal 42 with the side of the head of the rail 12 and the engagement of the arcuate portion 86 with the side of the rail creates a seal to prevent foreign material such as concrete, rocks, etc., from falling down into the space below the approach seal 42 .
As seen in FIG. 4, each of the gauge seals 62 generally has an outer end 88 , inner end 90 , upper end 92 , and lower end 94 . Gauge seal 62 is formed of a suitable elastomeric material and has lobe 96 in its inner end to aid in partially embedding the gauge seal 62 into the concrete of the gauge panel 24 . Gauge seal 62 is provided with a recessed area 102 to further aid in securing the gauge seal 62 to the gauge panel 24 . Gauge seal 62 is provided with a plurality of elongated voids 103 , 104 , 105 , 106 and 107 formed therein to reduce the amount of material required to fabricate the gauge seal. Recessed area 102 is defined by the vertical face 96 a of gauge seal 62 and the inclined face 96 b of lobe 96 . Lobe 96 also defines a lower surface 96 c having concrete positioned therebelow to further aid in attaching the gauge seal 62 to the panel 24 . The concrete which is positioned in the recessed area 102 outwardly of lobe 96 assists in preventing separation of gauge seal 62 from panel 24 . As seen in FIG. 2, the lower end of angle 56 is partially received (not embedded) in recessed area 102 . Void 103 also creates additional flexibility in the outer end of the gauge seal 62 so that it may flex somewhat so as to be in engagement with the arcuate portion of the inner end of the side of the associated rail. Gauge seal 62 is provided with an arcuate recessed portion 108 formed therein for sealing the flange of the railroad wheels moving along the rails.
FIG. 5 illustrates a second embodiment of the approach and gauge panel seals which are referred to by the reference numerals 42 ′ and 62 ′. Essentially, the only difference between the approach seals 42 and 42 ′ is that the lobe 76 ′ of approach seal 42 ′ is shaped somewhat differently than lobe 76 of approach seal 42 . Lobe 76 ′ has an upper inner head portion 120 having a shoulder 122 at its lower end which is in engagement with the portion 41 a of the retainers 41 which aids in supporting the approach seal 42 ′ within the approach panel 22 . Shoulder 124 is also provided at the inner lower end of lobe 76 ′ to also aid in attaching the approach seal 42 ′ to the panel. Lobe 76 ′ defines a recessed area 78 ′ which is generally similar to recessed area 78 in approach seal 42 .
Likewise, the only difference between the gauge seals 62 and 62 ′ is that the lobe 96 ′ of gauge seal 62 ′ is shaped somewhat differently than lobe 96 of gauge seal 62 . Lobe 96 ′ has an upper inner head portion 126 having a shoulder 128 at its lower end which is in engagement with the portion 61 a of the retainers 61 which aids in supporting the gauge seal 62 ′ within the gauge panel 24 . Shoulder 130 is also provided at the inner lower end of lobe 96 ′ to also aid in attaching the gauge seal 62 ′ to the panel. Lobe 96 ′ defines a recessed area 102 ′ which is generally similar to recessed area 102 .
FIG. 6 illustrates a third embodiment of the invention. The only difference between the embodiment of FIG. 5 and the embodiment of FIG. 6 is that the upper end of the approach seal 42 ′ is substantially co-planar with the upper end of the edge protector 38 and the approach panel 26 .
Thus it can be seen that the invention accomplishes at least all of its stated objectives.
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A concrete railroad grade crossing comprised of a precast concrete gauge panel extending between the rails and precast concrete approach panels which extend between each rail and the roadway. Elastomeric gauge seals are provided on the opposite sides of the gauge panels for sealing the space between the sides of the gauge panels and the rails. Elastomeric approach seals are provided on the inner ends of the approach panels for engagement with the outer sides of the rails. The inner ends of the seals have lobes formed therein which are embedded in the respective panels.
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FIELD OF THE INVENTION
[0001] The invention relates to compounds targeting metal isotopes to neurotensin receptor-positive tumors.
BACKGROUND OF THE INVENTION
[0002] Pancreatic adenocarcinoma, the tenth most common human cancer, grows extremely rapidly, disseminates early and occult metastases are frequent. Non invasive staging modalities have shown limited ability to detect local invasion or small volume metastatic disease. 18 F-labeled 2-deoxy-2-fluoro- D -glucose ( 18 F-FDG), which has greatly improved the diagnosis and staging of numerous tumors, does not significantly increase the accuracy of preoperative determination of resectability of pancreatic adenocarcinoma. Therefore, a non invasive method to improve preoperative staging would be extremely useful.
[0003] Indisputable success of scintigraphy and radiotherapy of neuroendocrine tumors has been obtained with somatostatin analogues labeled with radiometals, such as 111 In 68 Ga, 90 Y or 177 Lu. PET imaging with 68 Ga potentially provides higher diagnostic efficacy than SPECT. Therapy with 90 Y or 177 Lu affords symptomatic improvement, prolonged survival and better quality of life in some instances. However, somatostatin analogs only bind tumors that express somatostatin receptors.
[0004] It has been shown that 75-88% ductal pancreatic adenocarcinoma express neurotensin (NT) receptors, but little or no somatostatin receptors. NT receptors have been proposed as new markers for this tumor since they were not detected in normal pancreas and chronic pancreatitis. NT receptors were also identified in other tumor cells as, for example, Ewing's sarcoma, meningiomas, small cell lung carcinoma and colon adenocarcinoma. In patients with invasive ductal breast cancers, 91% of tumors are positive for the neurotensin high-affinity receptor (NTSR1), while it is poorly expressed or absent in normal cells (Souaze et al., Cancer Res. (2006) 66, 6243-6249). This recent work points out the diagnostic and therapeutic potential of molecules targeting NTSR1 receptor.
[0005] Neurotensin, the natural ligand for neurotensin receptors, is a thirteen amino acid peptide, isolated from bovine hypothalamus and has the following structure: pGlu-Leu-Tyr-Glu-Asn-Lys-Pro-Arg-Arg-Pro-Tyr-Ile-Leu-OH.
[0006] Examples of neurotensin analogues bearing a chelating moiety suitable for labeling with technetium or rhenium may be found in the literature, e.g. Garcia-Garayoa et al., Eur J Nucl Med Mol Imaging, (2009) 36(1), p. 37-47).
[0007] Acyclic or macrocylic poly(aminocarboxylate) compounds are suitable chelators for radioisotopes such as 111 In 67 Ga, 68 Ga, 90 Y, 86 Y, 177 Lu, 212 Bi, 213 Bi, 64 Cu, 67 Cu, 44 Sc, 44m Sc, 47 Sc. To target NTSR1 positive tumors, neurotensin ligands bearing acyclic or macrocyclic poly(aminocarboxylate) chelators such as DTPA or DOTA have thus been developed (de Visser et al., Eur. J. Nucl. Med. Mol. Imaging. (2003), 30, 1134-1139; Janssen et al., Cancer Biother Radiopharm. (2007), 22(3), 374-381; Hillairet de Boisferon et al., Bioconjug. Chem. (2002), 13, 654-662).
[0008] The efficiency of a compound targeting neurotensin receptor-positive tumors may be quantified by several criteria:
tumor uptake must be as high as possible, to allow their good detection or treatment; tumor to normal tissue uptake ratios must be as high as possible, to achieve good contrasts in imaging and to minimize the irradiation of normal tissue during treatment.
[0011] If some technetium or rhenium-labeled neurotensin analogues may be considered as reasonably good according to these criteria, neurotensin analogues bearing acyclic or macrocyclic poly(aminocarboxylate) chelating agent, such as DTPA, DOTA or one of their derivatives, described so far have shown lower tumor uptake, higher kidney accumulation or both.
[0012] Here is provided new poly(aminocarboxylate) neurotensin analogues providing higher tumor uptake and/or higher tumor to normal tissue uptake ratios, particularly higher tumor to kidneys uptake ratio, than poly(aminocarboxylate) neurotensin analogues previously described in the literature. This is particularly important at early time points after activity injection (preferably before 24 hours post-injection), so that:
high contrast images may be recorded before radioactive decay of the radionuclide reduces imaging sensitivity, and exposure of normal tissues—which is also maximum at early time points is reduced.
SUMMARY OF THE INVENTION
[0015] The invention relates to a neurotensin analogue, or a salt thereof, of formula (I)
[0000] X-L-Aa8-Aa9-Aa10-Aa11-Aa12-Aa13 (I)
[0000] wherein
Aa8 is selected from the group consisting of Arg, Lys, NMe-Arg, NMe-Lys, Gly(PipAm), Ala(PipAm), Phe(4-Gu), hAla(PipAm), Aba(Apy) and β-homoArg, Aa9 is selected from the group consisting of Arg, Lys, NMe-Arg, NMe-Lys, ψ(CH 2 —NH)-Arg, ψ(CH 2 —NH)-Lys, Gly(PipAm), Ala(PipAm) and Phe(4-Gu), Aa10 is selected from the group consisting of (L)Pro and thioproline, Aa11 is selected from the group consisting of (L)Tyr, (D)Tyr, Dmt, (L)Trp, (D)Trp, (L)Phe, (D)Phe, 2′Br-Tyr, 2′Br-Phe, (L)erythro-βMe-Tyr, (L)threo-βMe-Tyr, (L)mTyr, (D)mTyr, (L)7-HO-Tic, NaI, (L)Tcc and L-neoTrp, Aa12 is selected from the group consisting of Ile, Tle, Val and Leu, Aa13 is selected from the group consisting of Leu, tBuAla, Cha and Cpa, X represents a poly(aminocarboxylate) chelating moiety, L represents a linker which separates X and Aa8,
and wherein
said linker L separates X and Aa8 by a chain of at least 9 consecutive chemical bonds, said analogue, when in solution at physiological pH and at physiological temperature, has at most two positive charges, and Aa8-Aa9-Aa10-Aa11-Aa12-Aa13 differs from Arg-Arg-Pro-Tyr-Ile-Leu by at least two differences in the amino acid sequence.
[0027] The invention also relates to a pharmaceutical composition comprising a compound according to the invention and a pharmaceutically acceptable carrier.
[0028] The invention also relates to a neurotensin analogue according to the invention, further comprising a detectable element which forms a complex with the poly(aminocarboxylate) chelating moiety X. Said detectable elements is preferably selected from the group consisting of Gd 3+ , Eu 3+ , 111 In, 67 Ga, 68 Ga, 89 Zr, 64 Cu and 44 Sc.
[0029] According to the invention, the number of positive charges of the analogue does not take into account the positive charges of said detectable element.
[0030] The invention further relates to a neurotensin analogue comprising a detectable element according to the invention for use in a diagnostic method practiced on the human or animal body, and preferably in a diagnostic method of the presence of a tumor expressing neurotensin receptor 1. According to an embodiment of the invention, said method comprises the step of detecting the presence of a tumor expressing neurotensin receptor 1.
[0031] The present invention provides a method of detecting a tumor expressing a neurotensin receptor, neurotensin receptor 1 (NTSR1) in particular, in the body of a subject, to which a quantity sufficient for imaging of a neurotensin analogues comprising a detectable element has been previously administered, comprising the step of subjecting said body to imaging.
[0032] The invention further relates to a method of in vitro diagnostic of a tumor expressing a neurotensin receptor, neurotensin receptor 1 (NTSR1) in particular, comprising the step of detecting with a neurotensin analogue comprising a detectable element according to the invention, the presence of a tumor expressing a neurotensin receptor, neurotensin receptor 1 (NTSR1) in particular, in a sample obtained from a subject.
[0033] Further, the invention also relates to a neurotensin analogue comprising a cytotoxic element which forms a complex with the chelating moiety X. Said cytotoxic elements is preferably selected from the group consisting of 90 Y, 177 Lu, 67 Cu, 47 Sc, 212 Bi, 213 Bi, 226 Th, 111 In and 67 Ga.
[0034] According to the invention, the number of positive charges of the analogue does not take into account the positive charges of said cytotoxic element.
[0035] The invention further relates to a neurotensin analogue comprising a cytotoxic element according to the invention for use in a treatment of the human or animal body by therapy. According to an embodiment of the invention, said treatment is the treatment of a tumor expressing neurotensin receptor 1.
[0036] The present invention provides a method of treating a tumor expressing a neurotensin receptor, neurotensin receptor 1 (NTSR1) in particular, in the body of a subject, comprising the step of administering to said subject an effective amount of the neurotensin analogues comprising a cytotoxic element according to the invention.
[0037] Said tumor expressing neurotensin receptor 1 (NTSR1) may be, for example, a ductal pancreatic adenocarcinoma tumor, an exocrine pancreatic cancer tumor, an invasive ductal breast cancer tumor, a colon adenocarcinoma tumor, a small cell lung carcinoma tumor, an Ewing sarcoma tumor, a meningioma tumor, a medulloblastoma tumor and an astrocytoma tumor.
DEFINITIONS
[0038] Naturally occurring neurotensin has the formula:
[0000] pGlu 1 -Leu 2 -Tyr 3 -Glu 4 -Asn 5 -Lys 6 -Pro 7 -Arg 8 -Arg 9 -Pro 10 -Tyr 11 -Ile 12 -Leu 13 -OH
[0039] As used herein, the term “neurotensin analogue” covers all chemically modified derivatives of the naturally occurring neurotensin which have selective affinity to Neurotensin Receptor 1 (NTSR1), said derivatives being substituted by an X-L moiety.
[0040] The modifications by reference to the original chemical structure of naturally occurring neurotensin may be:
[0000] a) one or more amino acids have been omitted,
b) one or more amino acids have been replaced by one or more other amino acids, these amino acids being standard amino acids or amino acid mimics,
c) one or more amino acids have been functionalized.
[0041] The neurotensin analogues may have the following modifications: none; a; b; c; a and b; a and c; b and c; or a, b and c.
[0042] The neurotensin analogue may be linear or cyclic.
[0043] As used herein, a “selective affinity to NTSR1” means an affinity, when evaluated by the measure of IC 50 value for binding to HT29 cells, as described in the examples, lower than 100 nM, preferably lower than 50 nM. “IC 50” means the concentration of unlabeled drug that produces radioligand binding half way between the total binding of the radiotracer and the lower plateau of the curve describing the binding of the radioligand in presence of increasing concentrations of the unlabeled drug. Total binding means the binding of the radiotracer in the absence of the unlabeled drug.
[0044] As used herein, “standard amino acids” designates the twenty amino acids which are encoded by the standard genetic code. Standard amino acids are α-amino acids and their absolute configuration is L.
[0045] As used herein, an “amino acid mimic” designates a non-standard amino acid which has a substantially similar size and shape as a standard amino acid. Typically, the amino acid mimic can have modified side chain(s), a D absolute configuration, different side chain(s) or additional side chain(s) relative to a standard amino acid. For example, 2′,6′-dimethyltyrosine is an amino acid mimic relative to tyrosine, and β-homo-arginine an amino acid mimic relative to arginine.
[0046] Initials and acronyms used herein have the conventional meaning well-known to the skilled person. Typically, “NMe-Arg” means arginine with an N-methylated bond between arginine and the preceding amino acid, “NMe-Lys” means lysine with an N-methylated bond between lysine and the preceding amino acid, “ψ(CH2-NH)-Arg” means arginine with an reduced bond between arginine and the preceding amino acid, “ψ(CH2-NH)-Lys” means lysine with an reduced bond between lysine and the preceding amino acid, “Gly(PipAm)” means 4-piperidinyl-(N-amidino)-S-glycine, “Ala(PipAm)” means 4-piperidinyl-(N-amidino)-L-alanine, “Phe(4-Gu)” means 4-guanido-L-phenylalanine, “hAla(PipAm)” means 4-piperidinyl-(N-amidino)-L-homoalanine, “Aba(Apy)” means 2-amino-4[(2-amino)-pyrimidinyl]butanoic acid, “β-homoArg” means β-homo-arginine, “thioproline” means thiazolidine-4-carboxylic acid, “Dmt” means 2′,6′-dimethyltyrosine, “2′Br-Phe” means 2′-bromo-phenylalanine, “2′Br-Tyr” means 2′-bromo-tyrosine, “erythro-βMe-Tyr” means erythro-(2S,3S and 2R,3R)-β-methyltyrosine, “threo-βMe-Tyr” means threo-(2S,3R and 2R,3S)-β-methyltyrosine, “mTyr” means L-meta-tyrosine, “7-HO-Tic” means 7-hydroxy-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid, “Tcc” means 1,2,3,4-tetrahydro-2-carboline-3-carboxylic acid, “neoTrp” means 3-(4-indolyl)alanine, “Tle” means tert-leucine, “NaI” means naphtyl, “tBuAla” means tert-butyl-L-alanine, “Cpa” means cyclopentyl-L-alanine, “Cha” means cyclohexyl-L-alanine, “ACA” means L-azetidine-2-carboxylic acid, “Ahx” means aminohexanoic acid.
[0047] As used herein, “linker” designates any chemical moiety which is chemically coupled to X and Aa8, and which spaces the chelating moiety away from a portion of a peptide. Typically, the “linker” may be a combination of standard amino acids, of amino acid mimics, and of non-amino acid moieties.
[0048] As used herein, the term “chelating moiety” designates any chemical moiety which is able to form a complex with a detectable or cytotoxic element.
[0049] As used herein, a “detectable element” designates an element which exhibits a property detectable in conventional preferably human diagnostic techniques. The term “detecting” as used herein includes qualitative and/or quantitative detection (measuring levels) with or without reference to a control and the generation of images of the distribution of the detecting element in the animal or human body.
[0050] As used herein, a “cytotoxic element” designates an element which exhibits the property of being toxic to living cells.
[0051] As used herein, the terms “treatment”, “treating” and the like are intended to mean obtaining a desired pharmacologic and/or physiologic effect, such as inhibition of cancer cell growth or induction of apoptosis of a cancer cell, or killing cancer cells. The effect may be prophylactic in terms of completely or partially preventing a disease or symptom thereof and/or may be therapeutic in terms of a partial or complete cure for a disease and/or adverse effect attributable to the disease. “Treatment” as used herein covers any treatment of a disease in a mammal, particularly a human, and includes: (a) preventing the recurrence of a disease or condition (e.g., preventing cancer recurrence) from occurring in an individual who has been treated for the disease but has not yet been diagnosed as having a recurrence; (b) inhibiting the disease, (e.g., arresting its development and/or curing it); or (c) relieving the disease (e.g., reducing symptoms associated with the disease).
[0052] As used herein, the terms “administering” and “administration” are intended to mean a mode of delivery including, without limitation, parenteral, subcutaneous, intravenous, intraperitoneal, intraarterial, intracavitary, rectal or intravesical.
[0053] As used herein, the term “therapeutically effective” is intended to mean an amount of a compound sufficient to substantially improve some symptom associated with a disease or a medical condition. Preferably, by “therapeutically effective”, it is meant an amount of a compound sufficient to substantially improve tumor regression (which can be measured thanks to the RECIST—Response Evaluation Criteria in Solid Tumors—criteria) and/or to maintain stabilization and/or to substantially decrease cancer progression speed and/or to substantially improve survival without tumor progression and/or to substantially improve overall survival.
[0054] For example, in the treatment of cancer, a compound which decreases, prevents, delays, suppresses, or arrests any symptom of the disease would be therapeutically effective. To be considered therapeutically effective, the administered amount of a compound does not necessarily cure a disease, but provides a treatment for a disease such that the onset of the disease is delayed, hindered, or prevented, or the disease symptoms are ameliorated, or the term of the disease is changed or, for example, is less severe or recovery is accelerated in an individual. It will be understood that a specific “effective amount” for any particular individual will depend upon a variety of factors including the activity of the specific compound employed, the age, body weight, general health, sex, and/or diet of the individual, time of administration, route of administration, rate of excretion, drug combination and the severity of the particular disease undergoing prevention or therapy.
[0055] As used herein, “pharmaceutically acceptable carrier” includes any and all solvents (such as phosphate buffered saline buffers, water, saline), dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents and the like. The use of such media and agents for pharmaceutically active substances is well known in the art. Except insofar as any conventional media or agent is incompatible with the active ingredient, its use in therapeutic compositions is contemplated. Supplementary active ingredients can also be incorporated into the compositions.
DETAILED DESCRIPTION OF THE INVENTION
[0056] The compound according to the invention provides higher tumor uptake and/or higher tumor to normal tissue uptake ratios than poly(aminocarboxylate) neurotensin analogues previously described in the literature. The compounds were evaluated with regard to binding affinity, stability to enzymatic degradation, internalization rate and biodistribution.
[0057] Concerning the binding affinity of the neurotensin analogue, it is well known that the sequence NT(8-13), i.e. Arg 8 -Arg 9 -Pro 10 -Tyr 11 -Ile 12 -Leu 13 , is the minimal sequence that mimics the effects of full length NT (Granier et al., Eur. J. Biochem. (1982) 124, 117-124). The inventors have found that the introduction of a poly(aminocarboxylate) chelating moiety, coupled to the alpha NH 2 , results in an important loss of affinity. The inventors have found from the results described in the example section that this loss of affinity may be minimized by increasing the distance between the chelating moiety and the amino acid sequence.
[0058] The neurotensin analogue according to the invention comprises a chelating moiety X and a linker L which separates X and Aa8, said linker L separates X and Aa8 by a chain of at least 9 consecutive bonds, typically at least 10, typically at least 11, typically at least 12.
[0059] Typically L has no positive charge. Typically in order to avoid positive charges, if L comprises amino-acid, such as Lysine, the amino-acid may be modified (e.g. by acetylation, other possible modifications leading to the neutralization of a positive charge are well known to those skilled in the art).
[0060] Typically, X and Aa8 are separated by a chain of between 9 and 24 consecutive bonds.
[0061] According to an embodiment, the linker L is -Aa6-Aa7-.
[0062] According to another embodiment, the linker L is -L1-Aa6-Aa7-.
[0063] According to another embodiment, the linker L is R-Aa6(L1)-Aa7-, wherein L1 is coupled to Aa6 via the lateral chain of Aa6 and R is a group which neutralizes the positive charge of the α-NH 2 function of Aa6, typically R is an acetyl group. Typically R may also be an amino-acid sequence of 1 to 3 residues, preferably the N-terminal end of the amino-acid sequence is acetylated. Typically R has no positive charge, and if R is cleaved in vivo, the resulting group linked to Aa8 is not positively charged.
[0064] According to another embodiment, the linker L is -L1-Aa6-.
[0065] According to another embodiment, the linker L is -L1-Aa7-.
[0066] According to another embodiment, the linker L is -L1-.
[0067] In these different embodiments:
[0000] Aa6 is a standard amino acid or an amino acid mimic, without positive charges. More specifically, Aa6 may be selected from the group consisting of (D)Lys, (L)Lys, (L) or (D) lysine mimic, and (L) or (D) amino acids having a function on the lateral chain allowing the coupling of L1.
Aa7 may be selected from the group consisting of (L)Pro, (D)Pro and ACA, preferably Aa7 is (L)Pro.
L1 is a linker which is chemically coupled to X and Aa6, Aa7 or Aa8, and thereby spaces the chelating moiety away from Aa8. L1 may be a natural or a non natural aminoacid or an aminoacid sequence of natural and non natural aminoacids, a diacidic spacer or any spacer containing functions which allow the coupling of L1 to Aa6 or Aa7 or Aa8 and to X which are known to those skilled in the art.
L1 may be for example —NH—(CH 2 ) n —CO— wherein n is 1 to 10, —CO—(CH 2 ) n —CO—
wherein n is, preferably 1 to 10, or —NH—(CH 2 ) n —NH— wherein n is preferably 1 to 10.
Typically, L1 may be coupled to Aa6 or Aa7 or Aa8 and to X via an amide bond (NH—CO), via an urea bond (NH—CO—NH) or via a thio-urea bond (NH—CS—NH).
[0068] Typically L1 may be coupled to Aa6 via the lateral chain of Aa6. Alternatively L1 may be coupled to Aa6, Aa7 or Aa8 via the α-NH 2 function of the amino-acid.
[0069] A high binding affinity may be not enough for a neurotensin analogue to be efficient. Since NT is rapidly degraded in vivo by peptidases, changes may be introduced to protect the three major sites of enzymatic cleavage, the Arg 8 -Arg 9 , Pro 10 -Tyr 11 and Tyr 11 -Ile 12 bonds, to stabilize these molecules (Garcia-Garayoa et al., Nucl. Med. Biol. (2001) 28, 75-84). Possible sequence modifications are well-known by the skilled person. However, some sequence modifications induce a loss of affinity of the sequence. The influence on affinity of most of the sequence modifications has been studied (Bruehlmeier et al., Nucl. Med. Biol . (2002) 29, 321-327; Garcia-Garayoa et al., Eur. J. Nucl. Med. Mol. Imaging . (2009) 36, 37-47; Maes et al., J. Med. Chem . (2006) 49, 1833-1836). Sequence modifications may increase the in vitro and in vivo stability to enzymatic degradation. In vivo stability has a major impact on tumor uptake.
[0070] The inventors have found that increasing the distance between the chelating moiety and the amino acid sequence associated to one sequence modification was not sufficient to obtain an efficient in vivo tumor targeting.
[0071] The neurotensin analogue according to the invention comprises an amino acid sequence Aa8-Aa9-Aa10-Aa11-Aa12-Aa13, which differs from Arg-Arg-Pro-Tyr-Ile-Leu by at least two differences in the amino acid sequence. By difference in the amino-acid sequence, it is meant that the sequence differs from the one of the original neurotensin sequence at a given position either by difference in the amino acid side chain or by a modification in the main chain. The amino acids Aa8 to Aa13 and the bonds between these amino acids are selected from the groups as previously defined with the proviso that at least two amino acids are not selected equal to those of the naturally occurring amino acids, i.e. Arg for Aa8, Arg for Aa9, Pro for Aa10, Tyr for Aa11, Ile for Aa12, Leu for Aa13 and amide bonds between these amino acids.
[0072] In an embodiment of the invention, the neurotensin analogue has the formula (I)
[0000] X-L-Aa8-Aa9-Aa10-Aa11-Aa12-Aa13 (I)
[0000] wherein
Aa8 is selected from the group consisting of Arg, Lys, NMe-Arg and NMe-Lys, preferably Aa8 is NMe-Arg, Aa9 is selected from the group consisting of Arg, Lys, NMe-Arg and NMe-Lys, preferably Aa9 is selected from the group consisting of Arg and Lys, and if Aa8 is NMe-Arg or NMe-Lys, Aa9 is preferably Arg or Lys, Aa10 is Pro, Aa11 is selected from the group consisting of Tyr and Dmt, Aa12 is selected from the group consisting of Ile and Tle, preferably Aa12 is Tle, Aa13 is Leu, X represents a poly(aminocarboxylate) chelating moiety, L represents a linker which separates X and Aa8,
and wherein
said linker L separates X and Aa8 by a chain of at least 9 consecutive bonds, said analogue, when in solution in pure water at 37° C. at pH 7, has at most two positive charges, and Aa8-Aa9-Aa10-Aa11-Aa12-Aa13 differs from Arg-Arg-Pro-Tyr-Ile-Leu by at least two differences in the amino acid sequence.
[0084] Preferably, the neurotensin analogue according to the invention, or the salt thereof, has the above technical features and is of formula (I) above, wherein
Aa8 is NMe-Arg, Aa9 is Arg, Aa10 is Pro, Aa11 is selected from the group consisting of Tyr and Dmt, Aa12 is selected from the group consisting of Ile and Tle, preferably Aa12 is Tle, and Aa13 is Leu.
[0091] Further, to provide higher tumor to normal tissue uptake ratios, the biodistribution of the compound according to the invention has to be improved. It is already known that charge and charge distribution of radiolabeled peptides may produce various effects on renal uptake, but in general it is increased by positive charges (Akizawa et al., Nucl. Med. Biol . (2001) 28, 761-768; Froidevaux et al., J. Nucl. Med . (2005) 46, 887-895).
[0092] Therefore, the analogue according to the invention has at most two positive charges. If the compound comprises more than two positive charges, exceeding charges may be chemically neutralized. Typically, the N-terminal end of the peptide may be used for the coupling of the chelating moiety. Else, the N-terminal end of the molecule may be acetylated. In particular, if the chelating moiety X is coupled to an amino acid trough a function on its lateral chain, the N-terminal end of the molecule may be acetylated. Other possible modifications are known to those skilled in the art.
[0093] In addition, the inventors have found that kidney uptake may be ascribed to increased reabsorption of charged radiolabeled metabolites which are released after the cleavage of the neurotensin analogue.
[0094] The analogue according to the invention may be protected in order to avoid the formation of metabolites containing the chelating moiety and bearing more than two positive charges after cleavage of a peptide bond.
[0095] Further, the compounds according to the invention comprise a chelating moiety which is able to form a complex with a detectable element or with a cytotoxic element.
[0096] Suitable detectable elements include for example:
heavy elements or rare earth ions as used in computer axial tomography scanning (CAT scan or CT scan), paramagnetic ions as used in NMR imaging (e.g. Gd 3+ , Fe 3+ , Mn 2+ and Cr 2+ ), fluorescent metal ions (e.g. Eu 3+ ), and radionuclides, particularly γ-emitting radionuclides (e.g. 111 In and 67 Ga) as used in planar imaging and single photon emission computed tomography (SPECT, or less commonly, SPET), positron-emitting radionuclides as used in positron emission tomography (PET) (e.g. 68 Ga, 89 Zr, 64 Cu and 44 Sc).
[0101] More particularly, suitable radionuclides include those which are useful in diagnostic techniques. The radionuclides advantageously have a half-life of from 1 hour to 40 days, preferably from 5 hours to 4 days, more preferably from 12 hours to 4 days. Examples are radioactive isotopes of Indium and Gallium, e.g. 111 In and 68 Ga.
[0102] Suitable cytotoxic elements which are useful in therapeutic applications include β − -emitting radionuclides, e.g. 90 Y, 177 Lu, 67 Cu and 47 Sc, α-emitting radionuclides, e.g. 212 Bi, 213 Bi and 226 Th, and Auger-electron-emitting radionuclides, e.g. 111 In and 67 Ga.
[0103] According to the nature of the detectable or cytotoxic element which is complexed to the compound according to the invention, the chelating moiety X is selected from the group consisting of physiologically acceptable chelating groups capable of complexing said detectable or cytotoxic element.
[0104] The chelating moiety X is a poly(aminocarboxylate). It may be for example:
[0000] i) diethylenetriamine pentaacetic acid (or DTPA) and its derivatives, e.g.:
S-2(4-Aminobenzyl)-diethylenetriamine pentaacetic acid (or p-NH2-Bn-DTPA), (R)-2-Amino-3-(4-aminophenyl)propyl]-trans-(S,S)-cyclohexane-1,2-diamine-pentaacetic acid (or p-NH2-CHX-A″-DTPA), [(R)-2-amino-3-(4-isothiocyanatophenyl)propyl]-trans-(S,S)-cyclohexane-1,2-diamine-pentaacetic acid (or CHX-A″-DTPA), 2-(4-Isothiocyanatobenzyl)-diethylenetriaminepentaacetic acid (or p-SCN-Bn-DTPA),
ii) 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (or DOTA) and its derivatives, for example:
S-2-(4-aminobenzyl)-1,4,7,10-tetraazacyclo-dodecane tetraacetic acid (or p-aminobenzyl-DOTA), S-2-(4-Isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecane-tetraacetic acid (or p-SCN-Bn-DOTA),
iii) 1,4,7-triazacyclononane-1,4,7-triacetic acid (or NOTA) and its derivatives, for example:
S-2-(4-aminobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid (or p-NH2-Bn-NOTA) S-2-(4-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid (or p-SCN-Bn-NOTA)
iv) 1,4,8,11-tetraazacyclododecane-1,4,8,11-tetraacetic acid (or TETA) and its derivatives,
v) 1,4,7,10-tetraazacyclotridecane-N,N′,N″,N′″-tetracetic acid (or TITRA) and its derivatives,
vi) triethylenetetramine hexaacetic acid (or TTHA) and its derivatives,
vii) 1,4,7-triazacyclononane-1-glutaric acid-4,7-diacetic acid (or NODAGA) and its derivatives,
viii) 1,4,7-triazacyclononane-1-succinic acid-4,7-diacetic acid (or NODASA) and its derivatives.
[0113] According to one embodiment of the invention, DTPA or its derivatives (class i above) are selected to form a complex with a detectable element selected from indium and gallium isotopes, specifically 67 Ga, 68 Ga and 111 In.
[0114] According to another embodiment of the invention, DOTA or its derivatives (class ii above) is selected to form a complex with a detectable or cytotoxic element selected from indium, gallium, copper, scandium, yttrium, lutetium, bismuth, and thorium isotope, specifically 111 In, 67 Ga, 68 Ga, 64 Cu, 44 Sc, 90 Y, 177 Lu, 67 Cu, 47 Sc, 212 Bi, 213 Bi or 226 Th.
[0115] The invention relates very specifically to a neurotensin analogue of one of the following formulas:
[0000] Ac-Lys 6 (DTPA)-Pro 7 -NMe-Arg 8 -Arg 9 -Pro 10 -Tyr 11 -Tle 12 -Leu 13 -OH
[0000] Ac-Lys 6 (DOTA)-Pro 7 -NMe-Arg 8 -Arg 9 -Pro 10 -Tyr 11 -Tle 12 -Leu 13 -OH
[0000] Ac-Lys 6 (Ahx-DOTA)-Pro 7 -NMe-Arg 8 -Arg 9 -Pro 10 -Dmt 11 -Tle 12 -Leu 13 -OH
[0116] Regardless of whether the compound of the present invention is used for treatment or diagnosis, it can be administered parenterally, intravenously, intraperitoneally, by intracavitary or intravesical instillation, intraarterially or intralesionally. It may be administered alone or with a pharmaceutically or physiologically acceptable carrier, excipient, or stabilizer, in liquid form.
[0117] The treatment and/or therapeutic use of the compound of the present invention can be used in conjunction with other treatment and/or therapeutic methods. Such other treatment and/or therapeutic methods include surgery, radiation, cryosurgery, thermotherapy, hormone treatment, chemotherapy, vaccines, other immunotherapies, and other treatments and/or therapeutic methods which are regularly described.
[0118] The compounds of the present invention may be used in combination with either conventional methods of treatments and/or therapy or may be used separately from conventional methods of treatments and/or therapy.
[0119] When the compounds of this invention are administered in combination therapies with other agents, they may be administered sequentially or concurrently to an individual. Alternatively, pharmaceutical compositions according to the present invention may be comprised of a combination of a compound of the present invention, as described herein, and another therapeutic or prophylactic agent known in the art.
[0120] Further aspects and advantages of this invention will be disclosed in the following figures and examples, which should be regarded as illustrative and not limiting the scope of this application.
BRIEF DESCRIPTION OF THE FIGURES
[0121] FIG. 1 : In vivo serum stability of DTPA( 111 In)-peptides: representative C18 HPLC chromatograms of plasma samples collected 15 minutes post-injection to mice. A: reference peptide and NT(8-13) analogues, B: NT(6-13) analogues. Arrows show the intact peptide retention time. Mean percent radioactivity associated to intact peptide and individual values (between brackets) are indicated.
[0122] FIG. 2 : Degradation kinetics of DTPA( 111 In)-peptides in human serum. Peptides (2 pmol) were incubated with human serum (100 μL) at 37° C.: [Lys 6 (DTPA(In))]-NT open triangle, DTPA(In)-NT-20.1 black triangle, DTPA(In)-NT-20.2 open square, DTPA(In)-NT-20.3 black square (mean±sem, three independent experiments).
[0123] FIG. 3 : Internalisation of DTPA( 111 In)-NT20.3 in HT29 cells. Results are expressed as the ratio between internalized and specifically bound radioactivity (I/B, mean±sem, 3 experiments in triplicate).
[0124] FIG. 4 : DTPA( 111 In)-NT-20.3 planar images of a male nude mouse grafted with HT29 cells. A: photograph, B: planar anterior acquisition performed from 0 to 60 min post-injection under anaesthesia, C: dynamic series of images of 5 min each computed from the recorded scintigraphy data. B1: Bladder, K: Kidney, T: Tumor. Tumor weight: 240 mg.
[0125] FIG. 5 : SPECT/CT imaging of a male nude mice mouse grafted with HT29 cells in the right flank 2.5 h post-injection of DTPA( 111 In)-NT-20.3. Left: CT; center: SPECT, right: SPECT/CT fused images. Frames: A: coronal, B: axial, C: sagittal. Abbreviations as in FIG. 5 and r: right, 1: left, a: anterior, p: posterior. Tumor weight: 498 mg.
[0126] FIG. 6 : DOTA( 111 In)-NT-20.3 and DOTA( 111 In)-LB119 planar images of male nude mice grafted with HT29 cells. Planar anterior acquisitions were performed from 0 to 1 h, 1 to 1.5 h, 4.5 to 5.5 h, 24 to 25 h and 48 to 49 h post-injection under anaesthesia. B1: Bladder, K: Kidney, T: Tumor.
[0127] FIG. 7 : TEP imaging of a male nude mouse, grafted with HT29 cells in the right flank, injected with DOTA( 68 Ga)-NT-20.3: coronal frame 47 minutes post injection, 10 min acquisition, tumor volume: 40 mm 3 . B1: Bladder, K: Kidney, T: Tumor.
EXAMPLES
[0128] In the following examples DTPA-NT-20.3, DOTA-NT-20.3 and DOTA-LB119 are neurotensin analogues according to the invention. Other neurotensin analogues are presented for comparison.
1. Synthesis of the DTPA- and DOTA-NT Analogues
1.1 Synthesis of the DTPA-NT Analogues
[0129] DTPA-NT-VI, DTPA-NT-XI, DTPA-Ahx-NT-XII, DTPA-Ahx-NT-XIX are DTPA-NT(8-13) analogues, that were stabilized against enzymatic degradation at the bonds between Arg 8 and Arg 9 , Pro 10 and Tyr 11 or Tyr 11 and Ile 12 by changes introduced in the peptide sequence (Table 1).
[0130] DTPA-NT-20.1, DTPA-NT-20.2 and DTPA-NT-20.3 are analogues of the 6-13 sequence of [Lys 6 (DTPA)]-NT. The N terminal end was acetylated. In these analogues DTPA was coupled to the ε-NH 2 group of Lys.
[0131] All reagents used for the synthesis were obtained from Sigma-Aldrich (Saint Quentin Fallavier, France or Bornem, Belgium), Novabiochem (Läufelfingen, Switzerland), Bachem (Bubendorf, Switzerland) and RSP (Shirley, USA). The purity of the compounds was checked by HPLC on a Nucleosil C 18 (5 μm, 100 Å, Shandon, France) reverse phase column or on a Discovery®BIO SUPELCO Wide Pore (5 μm, 300 Å, Sigma-Aldrich) column with a gradient of A: water (0.05% TFA) and B: CH 3 CN (0.05% TFA) at a flow rate of 1 mL/min on a Waters apparatus.
[0132] The NT(8-13), NT-VI, NT-XI, NT-XII and NT-XIX peptides (Table 1) were prepared by solid phase peptide synthesis as described in detail elsewhere (Bruehlmeier et al., Nucl. Med. Biol . (2002) 29, 321-327; Maes et al., J. Med. Chem . (2006) 49, 1833-1836; Bergmann et al., Nucl. Med. Biol . (2002) 29, 61-72). Tris-tBu-DTPA (3 eq.) (Achilefu et al., J. Org. Chem . (2000) 65, 1562-1565) was coupled to the resin-bound neurotensin analog in a mixture of DMF/CH 2 Cl 2 using 2-1H(benzotriazol-1-yl)-1,1,3,3-tetramethylureum tetrafluoroborate (TBTU), 1-hydroxybenzotriazole (HOBt) and diisopropylethylamine (DIPEA) during 4 h.
[0133] The acetylated NT(6-13) analogues were synthesized by NeoMPS (Strasbourg, France). DTPA was coupled to the lysine ε-NH 2 as already described (Janevik-Ivanovska et al., Bioconjug. Chem . (1997) 8, 526-533).
[0134] All DTPA-peptides were purified to at least 92% purity and identified by mass spectrometry (Table 1).
[0000]
TABLE 1
Peptide sequence and analytical data
M + H +
M + H
Peptide
Sequence
% purity
MALDI-TOF
calculat
NT(1-13) analogues
NT
pGlu-Leu-Tyr-Glu-Asn-Lys-Pro-Arg-Arg-Pro-Tyr-Ile-
Leu-OH
[Lys6(DTPA)]-NT
pGlu-Leu-Tyr-Glu-Asn-Lys(DTPA)-Pro-Arg-Arg-Pro-
>95 a
2048.16 a
2048.32 a
Tyr-Ile-Leu-OH
NT(8-13) analogues
NT(8-13)
H-Arg-Arg-Pro-Tyr-Ile-Leu-OH
DTPA-NT(8-13)
DTPA-Arg-Arg-Pro-Tyr-Ile-Leu-OH
>96
1192.23
1192.62
DTPA-NT-VI
DTPA-Lys-Ψ(CH 2 -NH)-Arg-Pro-Tyr-Ile-Leu-OH
95
1150.12
1150.65
DTPA-NT-Xi
DTPA-Lys-Ψ(CH 2 -NH)-Arg-Pro-Tyr-Tle-Leu-OH
97
1150.33
1150.65
DTPA-Ahx-NTXII
DTPA-Ahx-Arg-Me-Arg-Pro-Tyr-Tle-Leu-OH
92
1319.11
1318.73
DTPA-Ahx-NT-XIX
DTPA-Ahx-Arg-Me-Arg-Pro-Dmt-Tle-Leu-OH
97
1346.50
1346.76
NT(6-13) analogues
NT-20.1
Ac-Lys-Pro-Arg-Arg-Pro-Tyr-Ile-Leu-OH
NT-20.2
Ac-Lys-Pro-Arg-Arg-Pro-Tyr-Tle-Leu-OH
NT-20.3
Ac-Lys-Pro-Me-Arg-Arg-Pro-Tyr-Tle-Leu-OH
DTPA-NT-20.1
Ac-Lys(DTPA)-Pro-Arg-Arg-Pro-Tyr-Ile-Leu-OH
>99
1459.78
1459.78
DTPA-NT-20.2
Ac-Lys(DTPA)-Pro-Arg-Arg-Pro-Tyr-Tle-Leu-OH
>97
1459.77
1459.78
DTPA-NT-20.3
Ac-Lys(DTPA)-Pro-Me-Arg-Arg-Pro-Tyr-Tle-Leu-OH
>99
1473.83
1473.80
DOTA-NT-20.3
Ac-Lys(DOTA)-Pro-Me-Arg-Arg-Pro-Tyr-Tle-Leu-OH
98
1484.83
1484.85
DOTA-LB119 b
Ac-Lys(Ahx-DOTA)-Pro-Me-Arg-Arg-Pro-Dmt-Tle-Leu-OH
>95
1627.08
1626.98
a Results already described (Hillairet De Boisferon et al., Bioconjug. Chem. (2002) 13, 654-662).
b Ahx: 6-aminohexanoic acid.
[0135] The following peptides DTPA-NT-20.3, DOTA-NT-20.3, DOTA-LB119 are neurotensin analogues according to the invention.
1.2. Synthesis of the DOTA-NT Analogues
[0136] All reagents used for the synthesis were obtained from Sigma-Aldrich (Saint Quentin Fallavier, France or Bornem, Belgium), Macrocyclics (Dallas, USA), Novabiochem (Läufelfingen, Switzerland), Bachem (Bubendorf, Switzerland) and RSP (Shirley, USA). The purity of the compounds was checked by HPLC on a Nucleosil C18 (5μm, 100 Å, Shandon, France) reverse phase column or on a Discovery®BIO SUPELCO Wide Pore (5 μm, 300 Å, Sigma-Aldrich) column with a gradient of A: water (0.05% TFA) and B: CH3CN (0.05% TFA) at a flow rate of 1.5 mL/min on a Waters apparatus.
[0137] The acetylated NT(6-13) analogue NT-20.3 (Ac-Lys-Pro-Me-Arg-Arg-Pro-Tyr-Tle-Leu-OH) was synthesized by NeoMPS (Strasbourg, France). 1,4,7,10-Tetraazacyclododecane-1,4,7-tris(acetic acid)-10-acetic acid mono(N-hydroxysuccinimidyl ester) (DOTA-NHS ester) (Macrocyclics, Dallas, Tex., USA) (5 eq.) was coupled to the lysine ε-NH2 of NT-20.3 (1 eq.) as described (1). This DOTA-NT20.3 was purified by C18 reverse phase chromatography (5 μm, 100 Å, Nucleosil, Shandon, France) using a linear 150-minute gradient (Flow: 2 mL/min, A: H2O/TFA(0.05%), B: acetonitrile/TFA(0.05%)) from 0% to 37% B. Coupling yield was approximately 85% for DOTA-NT-20.3.
[0138] DOTA-LB119 was obtained starting from Ac-Lys(Dde)-Pro-MeArg(Pbf)-Arg(Pbf)-Pro-Dmt(Trt)-Tle-Leu-OWang resin. After deprotection of the Dde protection using NH 2 OH.HCl/imidazole, (Brans et al., Chemical Biology & Drug Design, (2008) 72, 496-506). Fmoc-Ahx was coupled to the free ε-NH2 group of Lys (DIC/HOBt) followed by Fmoc deprotection and coupling of DOTA(OtBu) 3 using HATU. The peptide was cleaved from the resin using TFA/H2O/thioanisole/phenol/ethanedithiol (82.5:5:5:5:2.5), and purified by HPLC.
[0139] All DOTA-peptides were purified to at least 95% purity and identified by mass spectrometry (Table 1).
2. Radiolabeling
[0140] The DTPA-NT analogues were labeled with indium-111 ( 111 InCl 3 , 60 or 180 MBq, CIS bio International, France) in 100 mM acetate, 10 mM citrate, buffer pH 5 during 22 h at room temperature, then free DTPA groups were saturated with non-radioactive InCl 3 as already described (Raguin et al., Angew. Chem. Int. Ed. Engl . (2005) 44, 4058-4061). The DOTA-NT (1 nmol) analogues were labeled with indium-111 ( 111 InCl 3 , 10-20 MBq, CIS bio International, France) in 270 mM acetate, 27 mM citrate, buffer pH 4.5 during 25 minutes at 95° C.
3. Determination of the NTS1 Binding Affinities and Internalization Studies.
3.1. Materials and Methods
[0141] 3.1.1. Binding to HT29 Cell membranes.
[0142] Cell membranes (60 μg protein), were incubated for 45 min at room temperature in 250 μL buffer (50 mM Tris HCl, 5 mM MgCl 2 , 0.8 mM 1,10-phenanthroline, 0.2% BSA, pH 7.4), in the presence of 50 pM 125 I-Tyr 3 -neurotensin (Perkin-Elmer) and increasing concentrations of non-radioactive DTPA(In)-NT analogues. Membrane bound activity was recovered by filtration onto Whatman GF/B filters presoaked for 1 hour with polyethyleneimine (0.2% in water) and rinsed twice with buffer. Non-specific binding was evaluated in the presence of 10 −6 M neurotensin. Radioactivity was counted and results were analyzed with GraphPad Prism® (GraphPad Software, Inc. San Diego, Calif.). All experiments were performed three times in triplicate.
3.1.2. Binding to Living HT29 Cells and Internalization
[0143] IC50 for the binding to living HT29 cells were determined from competition experiments between [Lys 6 (DTPA( 111 In))]-NT and the peptides without DTPA or DTPA(In)-Ahx-NT-XIX. For the other DTPA-peptides IC50 was evaluated using the labeled DTPA( 111 In)-peptide and increasing concentrations of the corresponding non radioactive DTPA(In)-peptide. IC 50 of non radioactive DOTA(metal)-peptide complex (DOTA(Me)-peptide with Me:In; Y or Lu) was determined using trace amounts of 125 I-NT and increasing concentrations of the DOTA(Me)-peptide. For non radioactive metal chelation the DOTA-peptides (150 nmol in 150 μL water) were incubated (25 min 95° C.) with a solution of non radioactive InCl 3 , YCl 3 , or GaCl 3 (1.5 mmol in 150 μL acetate 100 mM, citrate 10 mM, buffer).
[0144] Cells were rinsed by 500 μL DMEM, 0.2% BSA, and incubated with the labeled analogue (DTPA( 111 In)-NT analogue 150 pM or 125 I-NT 40 pM, 300 μL DMEM, 0.2% BSA, 0.8 mM 1,10-phenanthroline, 60 min, 37° C.) in the presence of increasing concentrations of non-radioactive DTPA(In)-NT analogue or DOTA(Me)-peptide. After washing the wells twice with ice-cold DMEM 0.2% BSA, cells were lysed in 500 μL 0.1N NaOH and radioactivity was counted. Non-specific binding was evaluated in the presence of 10 −6 M neurotensin. Competition curves were analyzed with the “Equilibrium Expert” software (Raguin et al., Anal. Biochem . (2002) 310, 1-14). All experiments were performed three times in triplicate.
[0145] Incubation for internalization studies was performed with 0.15×10 −9 M DTPA( 111 In)-NT analogue or 0.5×10 −9 M DOTA( 111 In)-NT20.3 or DOTA( 111 In)-LB119 as above except for the use of twelve-well plates (600 μL). At selected times the total binding was evaluated as above. To determine the amount of internalized radioactivity wells were incubated in DMEM/0.2% BSA, pH 2.0 for 15 min at 4° C., to dissociate the surface-bound ligand. Internalized activity was then counted after washing. Non-specific binding and internalization was evaluated in the presence of 10 −6 M neurotensin. Results are expressed as the ratio between internalized and specifically bound radioactivity.
3.2. Binding and Internalization Results
[0146] K i values for binding to HT29 cell membranes and IC50 for binding to cells were used to evaluate affinity (Table 2). K i values for binding to HT29 membranes were, for most peptides, about 10 times lower than the IC50 for the binding to HT29 cells. This can be attributed to the decreased affinity for binding to the NTS1 induced by sodium (Kitabgi et al., Peptides (2006) 27, 2461-2468) and to the effects of internalization and externalization of radioactivity in cells.
[0147] DTPA(In) coupled to the NH 2 -α of NT(8-13) induced an important decrease in the affinity for membranes and for cells (by a factor of 31 and 32 respectively) as compared to NT(8-13). This loss of affinity is less important when the distance between the receptor-binding (8-13) sequence and DTPA is larger. When coupling DTPA to the ε-NH 2 of Lys 6 of NT, the affinity loss is only a factor of 6 for membranes and of 10 for cells. Similarly the affinity loss in DTPA(In)-NT-20.1 is only a factor of 9 and 8 as compared to NT-20.1. As a result, the affinity of DTPA(In)-NT-20.1 was two fold higher than that of DTPA(In)-NT(8-13), even though NT(8-13) displayed an affinity slightly higher than that of NT-20.1.
[0000]
TABLE 2
Affinity of peptides for binding to HT29 cells or cell membranes.
K i (nM)
Peptide
membranes
IC50 (nM) cells
NT
0.28 ± 0.05
1.67 ± 0.40
[Lys 6 (DTPA(In))]-NT
1.77 ± 0.39
17.3 ± 4.3
NT(8-13)
0.044 ± 0.009
0.68 ± 0.04
DTPA(In)-NT(8-13)
1.36 ± 0.39
21.7 ± 5.1
DTPA(In)-NT-VI
3.20 ± 0.81
14.7 ± 1.6
DTPA(In)-NT-XI
8.11 ± 1.03
101 ± 17
DTPA(In)-Ahx-NTXII
5.26 ± 1.24
132 ± 44
DTPA(In)-Ahx-NT-XIX
67 ± 11
626 ± 30
NT-20.1
0.072 ± 0.019
0.82 ± 0.08
NT-20.2
0.26 ± 0.07
2.46 ± 0.79
NT-20.3
0.16 ± 0.03
2.20 ± 0.31
DTPA(In)-NT-20.1
0.66 ± 0.1
6.73 ± 0.31
DTPA(In)-NT-20.2
1.55 ± 0.42
41.2 ± 6.2
DTPA(In)-NT-20.3
2.24 ± 0.21
15.9 ± 1.7
DOTA(In)-NT-20.3
ND
14.9 ± 1.1
DOTA(Ga)-NT-20.3
ND
13.9 ± 2.2
DOTA(Y)-NT-20.3
ND
7.0 ± 0.7
DOTA(In)LB119
ND
14.1 ± 0.7
DOTA(Ga)LB119
ND
7.5 ± 0.7
DOTA(Y)LB119
ND
9.9 ± 0.4
[0148] N-methylation of the Arg 8 -Arg 9 bond and introduction of an aminohexanoic acid spacer between DTPA and the 8-13 receptor binding sequence did not improve the affinity of DTPA(In)-Ahx-NT-XII as compared to DTPA(In)-NT-XI. Replacement of Tyr 11 by 2′,6′-dimethyltyrosine in DTPA(In)-Ahx-NT-XIX led to an additional loss of affinity.
[0149] Introduction of a Tle 12 in the NT(6-13) series induced a decrease in affinity similar to that observed in the DTPA(In)-NT(8-13) series. N-methylation of the Pro 7 -Arg 8 bond had little effect on affinity. Because the affinity of NT-20.1 was higher than that of NT, DTPA coupling and sequence modifications to the doubly-stabilized DTPA(In)-NT-20.3, the only peptide of this series which is a neurotensin analogue according to the invention, resulted in a high affinity, for membranes and for living cells, similar to those of the reference peptide [Lys 6 (DTPA(In))]-NT.
[0150] The DTPA(In)-peptides exhibiting the highest affinities, [Lys 6 (DTPA(In))]-NT, DTPA(In)-NT-VI, DTPA(In)-NT-XI, DTPA(In)-NT-20.1, DTPA(In)-NT-20.2, DTPA(In)-NT-20.3, were further evaluated for stability and tumor targeting in vivo.
[0151] DOTA coupling had similar effects as DTPA since DOTA(In)-NT20.3 affinity to cells was similar to that of its DTPA(In)-counterpart. The substitution of Tyr by Dmt and introduction of an aminohexanoic acid spacer between DOTA and the ε-NH2 of Lys 6 in DOTA(In)-LB119 had no effect on affinity.
[0152] The gallium chelate of DOTA-NT-20.3 exhibited an affinity similar to that of the indium complex, in opposition to the affinity increase of the yttrium chelate. Unexpectedly the gallium complexe of DOTA-LB119 displayed an affinity increase similar to that of the yttrium complexe as compared to the indium one. The high affinities observed for the complexes of DOTA-NT20.3 and DOTA-LB-119 with gallium and yttrium suggest that these peptides are suitable for in vivo targeting of their radioisotopes.
[0153] DTPA( 111 In)-NT-20.3 and DOTA( 111 In)-NT-20.3 internalized rapidly in HT29 cells, reaching a 86±3% and a 84±1% internalization plateau with a t 1/2 of 2.1±0.4 and 4.8±0.1 min respectively (Table 3). DOTA( 111 In)-LB119 internalization t 1/2 was significantly lower.
[0000]
TABLE 3
Peptide internalization in HT29 cells
t 1/2
Plateau
Peptide
(min)
(%)
[Lys 6 (DTPA( 111 In))]-NT
4.2 ± 1.1
88 ± 6
DTPA( 111 In)-NT-VI
3.8 ± 1.2
82 ± 6
DTPA( 111 In)-NT-20.3
2.1 ± 0.4
86 ± 3
DOTA( 111 In)-NT-20.3
4.8 ± 0.1
84 ± 1
DOTA( 111 In)-LB119
19.3 ± 0.7
93 ± 1
4. Metabolic Stability
4.1. In Human Serum
[0154] Serum from healthy donors (100 μL) was incubated with the DTPA( 111 In) analogues (2 pmol, 37° C.). Samples were collected at different time points and proteins were precipitated with methanol and filtered. Then methanol was evaporated under vacuum and the sample was analyzed by C 18 RP-HPLC. Detection was performed with a radioactivity detector (HERM LB 500, Berthold, France). Elution was performed using, after 5 min 0% B, a linear 10-minute gradient from 0% to 35% B and a linear 25-minute gradient from 35% to 50%, flow rate 1.5 mL/min. The sample was also co-injected with the radioactive control to identify the peak corresponding to intact peptide.
[0155] The in vitro stability in human serum was evaluated for 111 In-labeled DTPA-NT(6-13) analogues and for the reference peptide ( FIG. 2 , Table 4). In agreement with the in vivo results, the unprotected peptide DTPA( 111 In)-NT-20.1 was very rapidly degraded and DTPA( 111 In)-NT-20.3, a neurotensin analogue according to the invention, was more stable than DTPA( 111 In)-NT-20.2. These results confirmed the stabilizing effect of the two modifications. By contrast to the rapid degradation observed in vivo, the unprotected [Lys 6 (DTPA( 111 In))]-NT displayed an in vitro stability higher than that of the mono-stabilized DTPA( 111 In)-NT-20.2. These results point out the discrepancies that could occur between in vitro and in vivo degradation even when low tracer amounts are used in vitro in order to avoid saturation of peptidases (Garcia-Garayoa et al., Nucl. Med. Biol . (2001) 28, 75-84).
4.2. In Vivo Stability
[0156] Female BALB/c mice were injected in the tail vein with 111 In-labeled DTPA-NT analogues (25 pmol) or with 111 In-labeled DOTA-NT analogues (50 pmol). The mice were sacrificed 15 minutes after injection. Plasma and urine samples (50 μL) were added to 200 μL methanol and treated as above except for the DOTA-peptides for which elution was performed using, after 5 min 0% B, a linear 15-minute gradient from 0% to 35% B and a linear 25-minute gradient from 35% to 50%, flow rate 1.5 mL/min.
[0000]
TABLE 4
In vitro and in vivo stability of DTPA-peptides.
In vitro
In vivo stability
stability
(% intact peptide) b
Peptide
(t 1/2 h) a
in plasma
in urine
[Lys 6 (DTPA(In))]-NT
25 ± 2
4 (3-5)
0
DTPA(In)-NT-VI
ND
10 (5-15)
14.5 (15-14)
DTPA(In)-NT-XI
ND
47 (40-53)
21 (26-16)
DTPA(In)-NT-20.1
0.4 ± 0.02
0.8 (0.8-0.8)
0
DTPA(In)-NT-20.2
4.4 ± 0.6
10 (6-14)
0
DTPA(In)-NT-20.3
257 ± 71
26.5 (26-27)
24 (23-31-19)
a In vitro stability is expressed as the degradation half-life in human serum at 37° C.
b In vivo stability is expressed as the % intact peptide (mean (individual values)) recovered in plasma or urine 15 min after tracer injection
[0000]
TABLE 5
In vivo stability of DOTA-peptides.
In vivo stability
(% intact peptide) a
Peptide
in plasma
in urine
DOTA(In)-NT-20.3
21 ± 2
26 ± 6
DOTA(In)-LB119
28 ± 3
ND
a In vivo stability is expressed as the % of radioactivity associated to intact peptide (mean ± sem) recovered in plasma 15 min after tracer injection (n = 3-4)
[0157] The fraction of radioactivity associated to the intact 111 In-labeled peptide in serum and in urine determined 15 minutes after iv injection to BALB/c mice are presented in Table 4 and 5. Metabolites eluted by C 18 RP-HPLC chromatography at shorter retention times than the radioactive full-length peptide. The non-stabilized peptides [Lys 6 (DTPA(In))]-NT and DTPA( 111 In)-NT-20.1 were rapidly catabolized ( FIG. 1 , Table 4). Protection of Arg 8 -Arg 9 (DTPA( 111 In)-NT-VI) or Tyr 11 -Ile 12 (DTPA( 111 In)-NT-20.2) bonds improved the stability. Peptides with two or three sequence modifications were much more resistant (Table 4-5). Higher amounts of intact tracer were recovered in serum and about 20% of the intact peptide was excreted in urine.
6. Biodistribution and Imaging Studies
6.1 Biodistribution and Imaging Studies: Materials and Methods
[0158] All in vivo experiments were performed in compliance with the French guidelines for experimental animal studies and fulfill the UKCCCR guidelines for the welfare of animals in experimental neoplasia.
[0159] HT29 cells (6.7×10 5 cells) were injected subcutaneously in the flank of 6-8 week old athymic nu/nu mice, (Harlan, France). Two weeks later mice were i.v. injected with 111 In-labeled DTPA-NT analogues (20-50 pmol in 100 μL PBS) or DOTA-analogues (40-65 pmol, 0.5-0.7 MBq, except for mice dissected 49 h post injection: 500-900 pmol, 7-12 MBq) and sacrificed at different times. Blood, organs and tumors were collected, weighted and radioactivity was counted. Injected activity was corrected for losses by subtraction of non-injected and subcutaneously injected material (remaining in the animal tail). In blocked experiments each mouse received a co-injection of the labeled peptide and of its unlabeled counterpart (60 nmol of NT for [Lys 6 (DTPA(In))]-NT or 180 nmol of NT-20.3 for DTPA-NT-20.3, DOTA-NT-20.3 and of LB119 (Ac-Lys(Ahx)-Pro-Me-Arg-Arg-Pro-Dmt-Tle-Leu-OH) for DOTA-LB119). Statistical analysis of differences in the tissue uptake values was performed using unpaired t test for comparison between two groups, or ANOVA variance analysis followed by Newman-Keuls' test for multiple comparisons. Differences of p<0.05 were considered significant.
[0160] Scintigraphic imaging was performed under pentobarbital anesthesia after iv injection of the 11 In-labeled analogue (DTPA( 111 In)-NT-20.3: 30-50 pmol, 9-13 MBq, DOTA-NT analogues: 500-900 pmol, 7-12 MBq) using a dedicated small animal Gamma Imager-S/CT system (Biospace Mesures) equipped with parallel collimators (matrix 128×128, with 15% energy windows centered on both indium-111 peaks at 171 and 245 KeV). SPECT images (1 h acquisition) were obtained after volume reconstruction using an iterative algorithm. Tumor to background activity (evaluated in a ROI symmetrical to that of the tumor, counts per mm 2 ) ratio was evaluated on planar images. Radioactivity excretion in urine was determined from activity at 1 h post-injection in the bladder.
6.2 Results of Biodistribution and Imaging Studies of the DTPA-NT Series
[0161] The results of biodistribution studies of the DTPA-NT analogues, at 1 h and 3 h post-injection, performed in female nude mice grafted with HT29 cells are presented in tables 6 and 7. Biodistribution results of DTPA( 111 In)-NT-20.3 in female nude mice and in male nude mice from 1 h to 100 h after injection are presented in table 8 and table 9 respectively. They are expressed as the percentage of injected dose per gram of tissue (% ID/g).
[0000]
TABLE 6
Tissue distributions of [Lys 6 (DTPA( 111 In))]-NT and the DTPA( 111 In)-NT(8-13)
analogues in female nude mice grafted with HT29 cells.
DTPA( 111 In)-
DTPA( 111 In)-
[Lys6(DTPA( 111 In))]-NT
NT-VI
NT-XI
1 h
3 h
3 h blocked b
1 h
1 h
n = 6
n = 9
n = 8
n = 3
n = 3
Uptake (% ID/g) a
Blood
0.63 ± 0.12
0.06 ± 0.01
0.04 ± 0.01
0.24 ± 0.13
0.28 ± 0.02
Lungs
0.44 ± 0.06
0.07 ± 0.01
0.07 ± 0.01
0.21 ± 0.06
0.37 ± 0.02
Liver
0.22 ± 0.03
0.16 ± 0.07
0.09 ± 0.01
0.14 ± 0.06
0.19 ± 0.02
Spleen
0.19 ± 0.02
0.07 ± 0.01
0.45 ± 0.37
0.10 ± 0.02
0.18 ± 0.01
Stomach c
2.46 ± 2.01
0.26 ± 0.15
0.15 ± 0.09
0.06 ± 0.02
0.14 ± 0.02
Small intestine c
0.69 ± 0.09
0.59 ± 0.30
0.20 ± 0.09
0.28 ± 0.05
0.38 ± 0.07
Large intestine c
0.16 ± 0.02
0.71 ± 0.16
1.05 ± 0.47
0.17 ± 0.04
0.19 ± 0.04
Muscle
0.14 ± 0.03
0.03 ± 0.01
0.03 ± 0.01
0.11 ± 0.04
0.16 ± 0.08
Bone
0.13 ± 0.03
0.06 ± 0.01
0.03 ± 0.01
0.17 ± 0.05
0.13 ± 0.03
Tumor
1.02 ± 0.26
0.71 ± 0.18
0.22 ± 0.02
0.62 ± 0.06
0.52 ± 0.23
Kidney
12.50 ± 1.63
9.28 ± 0.73
7.18 ± 0.48
2.80 ± 0.37
3.90 ± 0.59
Tumor(T)/organ
T/Blood
3.3 ± 2.1
10.9 ± 1.7
5.7 ± 0.5
4.9 ± 2.5
2.0 ± 0.9
T/Liver
5.8 ± 2.3
9.3 ± 0.8
2.8 ± 0.6
6.2 ± 2.3
3.0 ± 1.4
T/Muscle
10.4 ± 4.8
33.1 ± 4.1
8.9 ± 1.3
9.6 ± 5.6
3.4 ± 1.6
T/Kidney
0.08 ± 0.02
0.11 ± 0.01
0.03 ± 0.01
0.20 ± 0.04
0.16 ± 0.07
a Uptake is expressed as the percentage of injected dose per gram of tissue (% ID/g).
b Blocked animals received a co-injection of the labeled peptide with neurotensin (60 nmol).
c Organ with its content.
[0000]
TABLE 7
Tissue distributions of the DTPA( 111 In)-NT(6-13) analogues in female nude mice grafted with HT29 cells.
DTPA( 111 In)-NT-20.1
DTPA( 111 In)-NT-20.2
DTPA( 111 In)-NT-20.3
1 h
3 h
1 h
3 h
1 h
3 h
3 h blocked b
Uptake (% ID/g) a
n = 3
n = 6
n = 5
n = 5
n = 6
n = 15
n = 4
Blood
0.19 ± 0.03
0.03 ± 0.00
0.31 ± 0.06
0.02 ± 0.01
0.70 ± 0.09
0.04 ± 0.01
0.04 ± 0.01
Lungs
0.17 ± 0.01
0.04 ± 0.01
0.30 ± 0.04
0.10 ± 0.04
0.73 ± 0.04
0.17 ± 0.03
0.12 ± 0.01
Liver
0.11 ± 0.01
0.06 ± 0.01
0.14 ± 0.01
0.07 ± 0.01
0.39 ± 0.04
0.17 ± 0.05
0.08 ± 0.01
Spleen
0.08 ± 0.01
0.05 ± 0.01
0.12 ± 0.01
0.06 ± 0.01
0.31 ± 0.01
0.11 ± 0.01
0.09 ± 0.01
Stomach (with
0.13 ± 0.04
0.02 ± 0.01
0.42 ± 0.17
0.04 ± 0.01
0.66 ± 0.19
0.17 ± 0.04
0.14 ± 0.04
content)
Small intestine
0.53 ± 0.20
0.18 ± 0.04
1.07 ± 0.44
0.16 ± 0.02
1.90 ± 0.22
1.30 ± 0.46
0.18 ± 0.05
(with content)
Large intestine
0.09 ± 0.01
1.65 ± 0.99
0.11 ± 0.02
0.46 ± 0.09
0.42 ± 0.05
1.03 ± 0.14
0.15 ± 0.04
(with content)
Stomach
ND
ND
ND
ND
ND
0.21 ± 0.03
0.09 ± 0.02
(without content)
Small intestine
ND
ND
ND
ND
ND
0.78 ± 0.10
0.10 ± 0.03
(without content)
Large intestine
ND
ND
ND
ND
ND
0.45 ± 0.04
0.09 ± 0.01
(without content)
Muscle
0.07 ± 0.01
0.01 ± 0.01
0.07 ± 0.01
0.01 ± 0.01
0.16 ± 0.01
0.03 ± 0.01
0.04 ± 0.01
Bone
0.07 ± 0.01
0.03 ± 0.01
0.43 ± 0.22
0.03 ± 0.01
0.22 ± 0.05
0.11 ± 0.02
0.28 ± 0.11
Tumor
0.46 ± 0.06
0.49 ± 0.12
0.93 ± 0.32
0.46 ± 0.09
3.27 ± 0.21
2.38 ± 0.21
0.14 ± 0.03
Kidney
1.44 ± 0.25
1.36 ± 0.10
2.55 ± 0.24
1.97 ± 0.26
7.49 ± 0.54
4.85 ± 0.25
4.81 ± 0.63
Tumor(T)/organ
T/Blood
2.5 ± 0.3
18.8 ± 4.7
4.6 ± 2.8
19.4 ± 3.7
5.6 ± 1.5
60.5 ± 6.8
3.7 ± 0.8
T/Liver
4.3 ± 0.4
8.5 ± 1.7
6.6 ± 2.1
6.5 ± 0.9
8.8 ± 0.6
19.1 ± 1.5
1.7 ± 0.2
T/Muscle
7.1 ± 1.9
35.6 ± 8.3
14.8 ± 6.7
34.0 ± 8.0
20.8 ± 1.4
91.6 ± 8.6
4.2 ± 1.0
T/Pancreas
ND
ND
ND
ND
17.5 ± 0.8
68.2 ± 6.5
ND
T/Kidney
0.32 ± 0.02
0.37 ± 0.04
0.35 ± 0.08
0.23 ± 0.01
0.44 ± 0.03
0.49 ± 0.04
0.03 ± 0.01
a Uptake is expressed as the percentage of injected dose per gram of tissue (% ID/g).
b Blocked animals received a co-injection of the labeled peptide with NT-20.3 (180 nmol).
[0162] DTPA( 111 In)-NT-20.3, which is in the DTPA-neurotensin series the only neurotensin analogue according to the present invention, displayed the highest tumor uptake as compared to other DTPA-NT analogues, about 3 fold higher than that of [Lys 6 (DTPA( 111 In))]-NT at 1 h (3.3±0.2 vs 1.0±0.3% ID/g, P<0.001) and at 3 h (2.4±0.2 vs 0.7±0.2% ID/g, P<0.001). Radioactivity uptake of other peptides in tumor was much lower. Particularly, DTPA( 111 In)-NT-20.2 with only one sequence modification displayed low tumor uptake though the chelating agent was separated from Aa8 by a chain of 11 consecutive bonds.
[0163] The difference observed between tumor retention at 1 h and 3 h post-injection for DTPA( 111 In)-NT-20.3 was not statistically significant, indicating a slow wash out of radioactivity from the tumor, confirmed by the 0.33±0.04% ID/g tumor uptake observed 100 h post-injection (Table 6).
[0164] Tumor uptake of [Lys 6 (DTPA( 111 In))]-NT or DTPA( 111 In)-NT-20.3 was receptor mediated since it was significantly reduced by co-injection of their unlabeled counterpart (78% reduction, P=0.02 and 94% reduction, P<0.0001 respectively).
[0165] Radioactivity in blood at 1 h post-injection was significantly higher for DTPA( 111 In)-NT-20.3 and [Lys 6 (DTPA( 111 In))]-NT than for other peptides. It decreased rapidly with time for both peptides. Radioactivity excretion in urine was fast and amounted 69±4% of the injected dose 1 h after injection for DTPA( 111 In)-NT-20.3. Low activity accretion was observed in normal tissues for all peptides except in kidneys and, particularly for DTPA( 111 In)-NT-20.3, in gastrointestinal tract. Nevertheless, for DTPA( 111 In)-NT-20.3, high uptake ratios were obtained between tumor and stomach (7.2±1.7 at 1 h and 30±7 at 3 h), small intestine (1.8±0.2 and 3.5±0.6) and colon (8.3±0.8 and 3.0±0.5).
[0166] The basis of the gastrointestinal uptake of DTPA( 111 In)-NT-20.3 (Table 7) has been investigated. In contrast to colon uptake, which was significantly decreased by co-injection of the unlabeled analogue (P=0.004), stomach and small intestine uptakes were not significantly reduced by the co-injection, despite the expression of NTS1 in these organs. Most of the activity was associated to the content of the organs (stomach: 68±4%, small intestine: 59±6%, colon 73±6%) indicating an elimination by the gastrointestinal route. When organ content was removed, co-injection of DTPA( 111 In)-NT-20.3 with its unlabeled counterpart significantly decreased uptake at 3 h post-injection in stomach (P=0.04), in small intestine (P=0.001), and in colon (P=0.0002). These results suggest that some uptake in these tissues is receptor mediated, but most of the activity comes from gastrointestinal elimination.
[0167] Kidney uptake of DTPA(In)-NT-20.3 in female nude mice was significantly lower than that of [Lys 6 (DTPA(In))]-NT and significantly higher than that of other tested peptides at 1 h and 3 h post-injection, with the exception of DTPA( 111 In)-NT-XI for which the difference was not significant. DTPA( 111 In)-NT-20.1 displayed the lowest renal accretion of the peptides tested in this DTPA series with 1.4±0.25% ID/g as soon as 1 h post injection.
[0168] Charge and charge distribution of radiolabeled peptides may produce various effects on renal uptake, but in general it is increased by positive charges (Akizawa et al., Nucl. Med. Biol . (2001) 28, 761-768; Froidevaux et al., J. Nucl. Med . (2005) 46, 887-895). One objective of the present invention was to lower kidney uptake as compared to the reference peptide. [Lys 6 (DTPA( 111 In))]-NT may, after cleavage in the 1-6 N-terminal end, release labeled metabolites with a free positively charged α-NH 2 , which could contribute to the high kidney uptake. To avoid the formation of these metabolites, the 1-6 N-terminal part of the molecule has been deleted and its N-terminal end has been acetylated to neutralize the positive charge. Cleavage of DTPA( 111 In)-NT-20.1 at the Arg 8 -Arg 9 bond may produce labeled metabolites with only one positive charge (Arg 8 ).
[0169] The same is true for DTPA( 111 In)-NT-20.2, which also exhibits low renal uptake. In DTPA( 111 In)-NT-20.3, the Arg 8 -Arg 9 bond is stabilized. Thus, a higher renal accumulation of radioactivity may be introduced by the release of metabolites with two positively charged Arg.
[0170] For DTPA( 111 In)-NT-20.3, tumor to normal tissues uptake ratios were elevated for most organs, particularly tumor/pancreas ratio was 17.5±0.8 and 68.2±6.5 at 1 and 3 h post injection respectively. They were markedly improved as compared to [Lys 6 (DTPA( 111 In))]-NT particularly tumor/blood (60.5±6.8 vs 10.9±1.7 P<0.0001 at 3 h post-injection), tumor/liver (19.1±1.5 vs 9.3±0.8 P<0.0001) and tumor/muscle (91.6±8.6 vs 33.1±4.1 P<0.0001). Tumor to kidney uptake ratio was also improved about five fold (0.49±0.04 vs 0.11±0.01 P<0.0001, 3 h post-injection) as a result of higher radioactivity uptake in tumor and lower accretion in kidney for DTPA( 111 In)-NT-20.3.
[0171] DTPA( 111 In)-NT-20.3, as compared to DTPA-neurotensin conjugates previously described in the literature provided in male mice higher tumor uptake and/or higher tumor to kidneys uptake ratios at early times post injection.
[0172] Accumulation of DTPA( 111 In)-NT-20.3 was clearly observed in tumors in planar at early ( FIG. 4 ) and late time points: 24, 48 and 100 h (not shown) post-injection and in tomographic images recorded in male mice ( FIG. 5 ). Kidneys and bladder were the only other sites of activity accumulation. Tumor was detected as soon as 30 minutes post-injection on sequential 5 minutes acquisition images. Tumor-to-background ratio increased with time reaching 2.8±0.7 at 1 h and 4.5±1.0 at 24 h. At 24 h, the activity ratio between tumor and kidneys was 1.3±0.4 (tumor weight: 0.428±0.095 g).
6.3 Results of Biodistribution and Imaging Studies of the DOTA-NT Series
[0173] Biodistribution studies of neurotensin analogues according to the invention DOTA( 111 In)-NT-20.3 (Table 10), the DOTA analogue of DTPA( 111 In)-NT-20.3, and DOTA( 111 In)-LB119 (Table 11) were also performed at various time post injection in male nude mice. No significant difference was observed between tumor accretion of DTPA( 111 In)-NT-20.3 and of DOTA( 111 In)-NT-20.3 at any time post-injection (Anova and Student-Newman-Keuls Multiple Comparisons Test), indicating similar tumor targeting efficacy of these two peptides. In the DOTA-NT series at early times post-injection DOTA( 111 In)-NT-20.3 displayed an higher tumor uptake than DOTA( 111 In)-LB119 (1 h and 3 h P<0.05), but DOTA( 111 In)-LB119 tumor uptake decreased slowly with time and from 6 h to 24 h no significant difference was observed between these two peptides.
[0174] Renal accumulation of radioactivity was lower for DOTA( 111 In)-LB119 than for DOTA( 111 In)-NT20.3 at early times (P<0.05 from 1 to 6 h).
[0175] DOTA( 111 In)-NT-20.3 and DOTA( 111 In)LB119 as compared to DOTA neurotensin conjugates previously described in the literature, provided in male mice higher tumor uptake and/or higher tumor to normal tissue uptake ratios, particularly higher tumor to kidneys uptake ratios at early times post injection.
[0176] The efficacy of DOTA-NT-20.3 to target 68Ga in vivo to tumors expressing the NTSR1 receptor is shown by the TEP images recorded with this peptide (Figure
[0000]
TABLE 8
Tissue distributions of DTPA( 111 In)-NT(20.3) in female nude mice grafted with HT29 cells from 1 h to 100 h.
DTPA-
NT-20.3
1 h
3 h
3 h blocked
6 h
24 h
48 h
100 h
Blood
0.70 ± 0.09
0.043 ± 0.005
0.039 ± 0.002
0.028 ± 0.002
0.012 ± 0.001
0.0055 ± 0.0007
0.0029 ± 0.0005
Lungs
0.73 ± 0.04
0.17 ± 0.03
0.12 ± 0.01
0.10 ± 0.01
0.10 ± 0.01
0.048 ± 0.007
0.029 ± 0.002
Liver
0.39 ± 0.04
0.17 ± 0.06
0.079 ± 0.008
0.10 ± 0.01
0.081 ± 0.006
0.082 ± 0.008
0.050 ± 0.002
Spleen
0.31 ± 0.01
0.11 ± 0.01
0.092 ± 0.008
0.10 ± 0.01
0.12 ± 0.02
0.089 ± 0.014
0.055 ± 0.003
Stomach
0.66 ± 0.19
0.17 ± 0.04
0.14 ± 0.04
0.14 ± 0.03
0.10 ± 0.02
0.047 ± 0.005
0.022 ± 0.004
Small
1.90 ± 0.22
1.30 ± 0.46
0.18 ± 0.05
0.42 ± 0.04
0.34 ± 0.04
0.23 ± 0.02
0.13 ± 0.01
intestine
Large
0.42 ± 0.05
1.03 ± 0.14
0.15 ± 0.04
0.51 ± 0.19
0.36 ± 0.11
0.17 ± 0.03
0.23 ± 0.11
intestine
Muscle
0.16 ± 0.01
0.029 ± 0.004
0.042 ± 0.014
0.021 ± 0.002
0.020 ± 0.002
0.011 ± 0.003
0.0095 ± 0.0012
Bone
0.22 ± 0.05
0.11 ± 0.03
0.27 ± 0.11
0.068 ± 0.010
0.065 ± 0.013
0.054 ± 0.009
0.028 ± 0.004
Tumor
3.27 ± 0.21
2.38 ± 0.21
0.14 ± 0.03
1.63 ± 0.19
1.41 ± 0.21
0.55 ± 0.07
0.33 ± 0.04
Kidney
7.49 ± 0.54
4.85 ± 0.25
4.81 ± 0.63
3.62 ± 0.38
3.13 ± 0.43
1.80 ± 0.38
0.83 ± 0.05
Pancreas
0.19 ± 0.01
0.032 0.001
tumor
0.48 ± 0.10
0.26 ± 0.046
0.0956 ± 0.028
0.49 ± 0.10
0.40 ± 0.041
0.1972 ± 0.02133
0.2327 ± 0.06114
weight
[0000]
TABLE 9
Tissue distributions of DTPA( 111 In)-NT(20.3) in male nude mice grafted with HT29 cells from 1 h to 100 h.
DTPA-NT-20.3
1 h
3 h
6 h
24 h
48 h
100 h
Blood
0.13 ± 0.03
0.026 ± 0.004
0.023 ± 0.004
0.0076 ± 0.0008
0.0028 ± 0.0005
0.0017 ± 0.0006
Lungs
0.63 ± 0.35
0.11 ± 0.01
0.13 ± 0.04
0.044 ± 0.003
0.035 ± 0.003
0.18 ± 0.05
Liver
0.12 ± 0.01
0.093 ± 0.008
0.07 ± 0.01
0.048 ± 0.003
0.040 ± 0.002
0.063 ± 0.007
Spleen
0.13 ± 0.01
0.13 ± 0.02
0.10 ± 0.01
0.074 ± 0.004
0.064 ± 0.004
0.106 ± 0.017
Stomach
0.14 ± 0.03
0.076 ± 0.015
0.15 ± 0.05
0.27 ± 0.08
0.033 ± 0.008
0.018 ± 0.003
Small intestine
1.05 ± 0.37
0.47 ± 0.13
0.61 ± 0.09
0.38 ± 0.05
0.19 ± 0.01
0.098 ± 0.014
Large intestine
0.46 ± 0.15
0.23 ± 0.03
1.38 ± 0.23
0.81 ± 0.13
0.15 ± 0.03
0.037 ± 0.005
Muscle
0.52 ± 0.42
0.14 ± 0.09
0.023 ± 0.005
0.023 ± 0.007
0.016 ± 0.004
0.0083 ± 0.0027
Bone
0.20 ± 0.06
0.10 ± 0.020
0.083 ± 0.013
0.044 ± 0.003
0.027 ± 0.004
0.036 ± 0.005
Tumor
3.05 ± 0.36
1.99 ± 0.39
2.00 ± 0.24
0.86 ± 0.06
0.92 ± 0.13
0.38 ± 0.01
Kidney
7.79 ± 1.00
6.54 ± 1.69
2.84 ± 0.32
1.89 ± 0.33
1.50 ± 0.34
0.48 ± 0.08
tumor weight
0.26 ± 0.06
0.35 ± 0.04
0.40 ± 0.07
0.40 ± 0.042
0.65 ± 0.19
0.40 ± 0.07
[0000]
TABLE 10
Tissue distributions of DOTA( 111 In)-NT(20.3) in male nude mice grafted with HT29 cells from 1 h to 49 h.
DOTA-NT-20.3
1 h
3 h
3 h blocked
4 h 30
6 h
24 h
49 h
Blood
0.36 ± 0.06
0.033 ± 0.014
0.13 ± 0.01
0.015 ± 0.001
0.038 ± 0.012
0.0028 ± 0.0003
0.0028 ± 0.0004
Lungs
0.47 ± 0.04
0.14 ± 0.02
0.16 ± 0.01
0.12 ± 0.01
0.11 ± 0.01
0.061 ± 0.004
0.068 ± 0.011
Liver
0.21 ± 0.02
0.13 ± 0.02
0.12 ± 0.01
0.14 ± 0.01
0.12 ± 0.01
0.085 ± 0.002
0.072 ± 0.013
Spleen
0.19 ± 0.01
0.11 ± 0.01
0.10 ± 0.01
0.11 ± 0.01
0.11 ± 0.01
0.10 ± 0.01
0.16 ± 0.01
Stomach
0.13 ± 0.03
0.22 ± 0.12
0.081 ± 0.017
0.12 ± 0.03
0.092 ± 0.037
0.057 ± 0.013
0.020 ± 0.005
Small intestine
0.85 ± 0.10
0.52 ± 0.08
0.12 ± 0.02
0.58 ± 0.05
0.34 ± 0.06
0.32 ± 0.02
0.070 ± 0.003
Large intestine
0.39 ± 0.05
1.13 ± 0.30
0.18 ± 0.08
2.22 ± 0.96
1.47 ± 0.45
0.19 ± 0.02
0.058 ± 0.007
Muscle
0.10 ± 0.02
0.027 ± 0.008
0.053 ± 0.013
0.022 ± 0.005
0.042 ± 0.011
0.012 ± 0.001
0.008 ± 0.001
Bone
0.15 ± 0.02
0.10 ± 0.02
0.13 ± 0.03
0.056 ± 0.016
0.10 ± 0.01
0.030 ± 0.005
0.053 ± 0.002
Tumor
4.72 ± 0.76
2.48 ± 0.19
0.14 ± 0.02
2.40 ± 0.21
1.86 ± 0.20
1.26 ± 0.15
0.68 ± 0.09
Kidney
7.55 ± 0.85
4.89 ± 0.40
6.70 ± 0.23
4.07 ± 0.28
5.16 ± 0.47
2.50 ± 0.12
0.86 ± 0.08
pancreas
0.10 0.01
0.033 ± 0.010
0.028 ± 0.001
0.030 ± 0.002
tumor weight
0.20 ± 0.03
0.185 ± 0.036
0.055 ± 0.010
0.14 ± 0.03
0.11 ± 0.03
0.21 ± 0.03
0.148 ± 0.042
[0000]
TABLE 11
Tissue distributions of DOTA( 111 -In)-LB119 in male nude mice grafted with HT29 cells from 1 h to 49 h.
DOTA-LB119
1 h
3 h
3 h blocked
6 h
24 h
49 h
Blood
0.38 ± 0.05
0.023 ± 0.002
0.042 ± 0.008
0.0045 ± 0.0002
0.0074 ± 0.0018
0.0021 ± 0.0003
Lungs
0.36 ± 0.03
0.11 ± 0.01
0.086 ± 0.010
0.086 ± 0.014
0.060 ± 0.013
0.041 ± 0.010
Liver
0.20 ± 0.01
0.15 ± 0.01
0.077 ± 0.005
0.14 ± 0.02
0.080 ± 0.005
0.089 ± 0.026
Spleen
0.15 ± 0.01
0.087 ± 0.011
0.077 ± 0.007
0.076 ± 0.009
0.064 ± 0.003
0.095 ± 0.027
Stomach
0.28 ± 0.08
0.16 ± 0.04
0.37 ± 0.21
0.52 ± 0.46
0.080 ± 0.013
0.024 ± 0.004
Small intestine
1.11 ± 0.10
0.67 ± 0.08
0.50 ± 0.19
0.69 ± 0.14
0.35 ± 0.05
0.084 ± 0.005
Large intestine
0.44 ± 0.12
1.54 ± 0.53
0.17 ± 0.07
1.24 ± 0.81
0.16 ± 0.03
0.10 ± 0.01
Muscle
0.094 ± 0.013
0.021 ± 0.005
0.03 ± 0.01
0.049 ± 0.023
0.010 ± 0.003
0.015 ± 0.007
Bone
0.15 ± 0.03
0.047 ± 0.011
0.10 ± 0.05
0.068 ± 0.018
0.053 ± 0.010
0.049 ± 0.020
Tumor
1.83 ± 0.13
1.41 ± 0.05
0.12 ± 0.03
1.35 ± 0.18
0.98 ± 0.27
0.46 ± 0.06
Kidney
3.37 ± 0.20
2.40 ± 0.21
2.18 ± 0.19
2.15 ± 0.19
1.04 ± 0.07
0.64 ± 0.12
Pancreas
0.081 ± 0.008
0.022 ± 0.001
0.026 ± 0.006
0.018 ± 0.001
0.018 ± 0.001
0.013 ± 0.002
tumor weight
0.124 ± 0.019
0.306 ± 0.030
0.181 ± 0.018
0.121 ± 0.032
0.202 ± 0.095
0.195 ± 0.051
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The invention relates to a new neurotensin analogue, or a salt thereof, useful for targeting to neurotensin receptor-positive tumors, like ductal pancreatic adenocarcinoma, exocrine pancreatic cancer, invasive ductal breast cancers, colon adeno-carcinoma, small cell lung carcinoma, Ewing sarcoma, meningioma, medulloblastoma and astrocytoma.
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This application is a division of application Ser. No. 07/186,861, filed Apr. 27, 1988 U.S. Pat. No. 4,828,662.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the electrochemical removal of a surface layer from an article, and more particularly but not exclusively to the removal of a defective coating from data storage disc to facilitate recoating.
2. Background Art
A known data disc comprising as substrate a disc of aluminium is approximately 130 mm diameter by 1.9 mm thick when coated. A central aperture of 40 mm diameter penetrates the disc. These data discs are coated overall by a sequence of sputter coating, electroless coating or other plating treatments to create a finished disc having a substrate core disc of aluminium having a zincate treatment on both sides clad by a layer of nickel; a layer of cobalt covering the nickel; a thin (flash) layer of chromium on the cobalt; and outer layer of carbon covering the flash layer of chromium. During manufacture of these discs defects may arise in any of the deposited layers. Current practice is to examine the finished discs and discard any that fail to meet the test criteria.
SUMMARY OF THE INVENTION
One objective of this invention is to provide a method of recovering as much value as possible from defective discs by removing one or more of the layers so that any sound remaining material may be recoated to manufacture a vendible disc.
Another objective of this invention is to provide a method of removing the cobalt layer to uncover the textured finish on the nickel layer. This textured finish is in the form of circular grooves which assist the aerodynamic forces and help align magnetic domains. The brushing or wiping technique used to create the textured finish is quite costly so it is advantageous to retain the finish.
The stripping of coatings from data discs by means of acid treatments has been reported but these acid systems require great care in order to avoid stripping off more than the defective layer.
In contrast the present invention uses high pH electrolytes and application of controlled potential differences between the disc and a counter electrode to achieve a controlled degree of stripping.
In a first aspect this invention provides a method of removing a layer of cobalt from a nickel surface of an article, said method comprising the steps of immersing at least part of the article in an aqueous solution of caustic alkali, and applying an electrical potential difference between the article and a counter electrode which acts as a cathode to strip the cobalt from the article and maintain the nickel in the passive state.
The pH value of the aqueous solution of caustic alkali is preferably greater than 12.5. A preferred value is about 14.
In one embodiment of the method the aqueous solution is 20% Na OH in distilled water. The electrical potential difference is within the range of 10 to 15 volts. In a preferred method the solution is stirred or agitated either by an impeller or by rotating the article which may be a data storage disc made of aluminium coated with nickel. The article may, after anodic stripping be cleaned by a cathodic treatment in which the article is immersed in a buffer solution of citric acid and sodium citrate and an electrical potential difference is applied between the article and a counter electrode.
In another aspect this invention provides apparatus for removing a layer of cobalt from the nickel surface on a disc, said apparatus comprising a trough to contain electrolyte sufficient to immerse most of the disc, means to support the disc for rotation, and means to make electrical contact with the periphery of the disc at a point above the meniscus of the electrolyte.
The means to contact the periphery of the disc may comprise a guide tube, a brush member slidable in the guide tube and resilient means in the form of an elastomeric block in the guide tube to urge the brush member towards the periphery of the disc. The guide tube may be shrouded by a sleeve of polymeric material having a cleft at one end to wipe the periphery of the disc before electrical contact is made.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective sketch of a data disc;
FIG. 2 is an enlarged fragmentary section through the disc of FIG. 1;
FIG. 3 is a fragmentary section of the disc of FIG. 2 after removal of surface layers;
FIG. 4 is a sectioned side view of apparatus for removing surface coatings;
FIG. 5 is a sectioned end view of the apparatus of FIG. 4; and
FIG. 5A is an enlarged side view of part of a disc and contact brush;
FIG. 6 is a sectioned side view of an alternative contact brush support;
FIG. 7 is a perspective sketch of the brush support of FIG. 6;
FIG. 8 is a graph (a) of voltage v current before stripping; and a graph (b) on a larger scale of voltage v current after stripping.
FIGS. 9 and 10 are scanning electron microanalysis traces of discs before and after stripping of a cobalt coating.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a data storage disc of 130 mm diameter, approximately 2 mm thick and having a central aperture of 40 mm diameter. FIG. 2 shows that the disc 1 comprises a core 2 of aluminium coated overall with a zincate coating 3. A layer of nickel 4 covers the zincate coating 3. A layer of cobalt 5 covers the nickel layer 4. A thin "flash" layer of chromium 6 covers the cobalt layer 5 and a layer of carbon 7 covers the "flash" of chromium. The various layers are usually deposited by a sequence of sputtering or electrolytic coating treatments as already mentioned.
If, after deposition of the various layers, any layer on a disc was found to be defective the defective disc was scrapped at considerable cost. The present invention seeks to abate this loss by stripping off the defective layers to retain as much sound material as possible for retreatment.
FIG. 3 shows the disc after the carbon, chromium, and cobalt layers have been stripped away to leave a nickel covered disc ready for recoating.
The defective layers are removed by a series of steps which include:
1. Precleaning by cathodic cleaning procedure or other means. This step may not be necessary if the discs are factory scrap but may be desirable if used discs are being recycled.
2. Whole or partial immersion of the disc in a treatment bath containing an electrolyte and having means to apply an electrical potential difference between the disc and a counter electrode.
3. Application of a controlled electrical potential difference to create a passive condition on the nickel surface but also remove the covering layers.
4. During electro stripping the discs may be rotated or alternatively the electrolyte may be stirred or both.
5. Rinsing of the stripped discs in deionised water.
6. Transfer of the stripped discs to a cleaning bath in which a cathodic treatment is applied. The cleaning solution will generally be of a lower pH than the treatment bath.
7. Application of necessary potential to effect cathodic cleaning.
8. Rinsing and drying of discs - effected by deionised water and clean dry air respectively. Alternatively a displacement drier using `FREON` may be used.
Removal of each layer requires a specific treatment; for example:-- To remove a defective carbon layer the disc is dipped in a solution of 35% nitric acid in water for 5 to 10 seconds and then vigorously rinsed in deionised water to remove the loosened carbon.
To remove a defective cobalt layer, the covering layers if present, are first removed by the acid treatment used to remove the carbon. The cobalt covered disc is then immersed in a solution of 20% caustic soda (Na OH) in distilled water, this electrolyte having a pH approximately equal to 14. A total cell voltage of 10 to 15 volts, measured across the disc and a counter electrode, is applied to achieve a current density (for a disc of 130 mm diameter) of between 1 to 6 amps/single disc face area; a useful current density is about 3 amps/disc single face area, (approximately 75 m A /sq.cm).
Clearly some variation in current density and consequently time scale is possible. It is desirable that the current density is in the range of 50 m A to 100 m A per sq.cm. Current densities greater than about 10 m A /disc face may be employed but such low current densities are less reliable than the preferred range indicated above because such low current densities may not maintain the under-layer of nickel in a passive state. The current is applied for a period of time, usually about 10 seconds to remove the cobalt covering and leave the nickel layer intact with its textured surface unimpaired.
FIG. 8 shows typical current v. voltage plots arising from study of a small sample cut from disc before (as shown in graph (a)) and after stripping (as shown in graph (b)) of the cobalt layer. To confirm the success of the stripping process as indicated by this potential scanning test, further samples were tested by examination under a scanning electron microscope (SEM) the results of which are shown in FIGS. 9 and 10.
In FIG. 9, which arises from study of an unstripped disc, it will be seen that both cobalt and nickel are present as indicated by their Ka peaks. It will also be noticed that some phosphorus is associated with the nickel layer. In FIG. 10 it will be seen that the stripped disc manifests the Ka peak for nickel but no peak is apparent for cobalt so success of the anodic stripping process is confirmed.
During electrolytic stripping of the cobalt the surface of the disc may become darkened to a dark brown or black colour. This colouration is easily removed by a cathodic treatment.
To clean a disc stripped of cobalt, each disc is immersed in a buffer solution of 12.8 g of citric acid and 11.2 g of sodium citrate per liter of water (pH=4) and a current of 3 amps per face of the disc is passed with the disc as cathode to a counter electrode for a period of about 20 seconds. During this treatment it is desirable to rotate the disc or agitate the solution or both. Rubbing of the surface of the disc with a gloved finger or brush assists removal of the dark colouration.
From the foregoing explanations it will be understood that it is possible to take discs at any stage in production at which defects are detected and strip off a defective layer or layers to leave the disc ready for retreatment.
Should defects in the nickel layer expose aluminium they should be revealed by rapid attack during the immersion in caustic soda solution at a high pH value. In fact none of the discs examined have behaved thus but a potentially useful test appears to be available.
FIGS. 4 and 5 show, in simplified form, apparatus for carrying out the anodic or cathodic treatments described above.
In FIGS. 4 and 5 the apparatus comprises a trough 10 and a lid 12. The trough contains the electrolyte through which passes three spindles 13, 14, 15. The spindles each have a plurality of annular grooves aligned with like grooves in the other spindles so that a group of three annular grooves of the spindles is able to support a disc 17 upright with a small arc of the disc protruding above the meniscus of the electrolyte.
Each spindle 13, 14, 15, passes through an end wall of the trough 1 to terminate in a gear wheel 18, 19 which is meshed with like gear wheels of the other spindles so that rotation of any one of the gear wheels by a motor causes all the spindles to rotate and so rotate all discs in the trough to make continued contact with respective contact brushes fixed in the lid 2.
The lid 12 is made up of layers of insulating material which contain an electrically positive busbar 21 and a negative busbar 22. Brush holders, fixed to each busbar protrude through the insulating layers to support contact brushes 20 in conductive contact with the periphery of a respective disc as can be seen in FIG. 5A.
For an anodic treatment of discs, the discs to be treated will be fitted into the apparatus in contact with the contact brushes of the positive busbar 21. Further discs (which may be plain aluminium discs) will be fitted in contact with the brushes of the negative busbar 22 to act as counter electrodes.
The caustic soda 20% Na OH solution, having a pH=14, is corrosive to many brush materials.
In FIG. 6 it will be seen that the brush support may comprise a guide tube 23 attached to busbar 22 and passing through the insulating layer 24 to terminate at a distance from the periphery of the disc 17. A brush member 20 is resiliently urged by a block 25 of rubber or suitable elastomeric polymer to slide along the guide tube to make electrical contact between the charged guide tube 23 and the periphery of the disc 17. As the springy block 25 is a snap fit in the busbar 22 and a snug fit in the guide tube there is minimal risk of electrolyte interferring with its action. If desired a spring may be used instead of the resilient block but care must be taken to choose a spring material that will not corrode. The brush member is also a snug fit in the guide tube so that it makes good electrical contact with the guide tube and therefore stays reasonably clean, but replaceable when it becomes worn by pushing the springy block 25 out of its busbar.
A sleeve 26 of polymeric tubing is slid onto the exterior of the exterior of the guide tube 23 to protect it. The sleeve 26 extends from the insulating layer 24 to surround the terminal end of the brush member 20. Diametrically spaced clefts 27 in the end of the sleeve serve to act as wiping surfaces to wipe off electrolyte from the periphery of the disc as it is presented to the brush member so that contact of the brush member with caustic soda solution is minimised.
Whilst a compression spring or block has been described a leaf spring clad in a polymeric tube may be used to support the brush by a cantilever action, an advantage being that such a cantilever has no sliding parts to become encrusted or immovably corroded.
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A method of removing a layer of cobalt from an underlying nickel surface of an article comprises the steps of immersing at least part of the article in an aqueous solution of a caustic alkali having a pH value not less than 12.5 and preferably not less than 14, and applying an electrical potential difference between the article and a counter electrode which acts as a cathode to strip the cobalt from the article leaving the nickel passive. The method is particularly suitable for removing a defective cobalt layer from a data storage disc so that the disc can be recoated.
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BACKGROUND
1. Field of the Invention
The present invention relates to a displacement detecting device, a scale calibrating method and a scale calibrating program applied to a linear encoder, a rotary encoder, etc.
2. Description of the Related Art
Generally, measurement error of a displacement measuring device such as an encoder is evaluated before shipment. A highly accurate displacement sensor such as a laser interferometer is used for a reference for error evaluation. The thus obtained error data are shipped in the form of a pre-shipment inspection table together with the encoder so as to be used as important data for warranting performance of the encoder.
However, the scale of the encoder may be distorted according to the material and length of the scale and the fixing method when the scale of the encoder is attached to an application such as a machine tool, a measuring device, etc. In some cases, non-negligible level measurement error in regard to a required specification may be caused by the generated distortion of the scale so that reliability of error data evaluated in advance will be spoiled.
As a method for solving this problem, it is thought of that a reference displacement sensor is set up in a user's application to apply on-machine calibration to the measurement error of the encoder. It is however undesirable that a burden is imposed on the user in consideration of the labor for setting up the displacement sensor and the price of the highly accurate displacement sensor.
On the other hand, for example, methods for self-calibration measurement error on graduations of a scale (JP-A-2008-224578 and “Satoshi Kiyono, “Intelligent Precision Measurement”, The Japan Society for Precision Engineering, 2009, Vol. 75, No. 1, pp. 89-90”) are known in this type displacement detecting device. Use of these self-calibration methods permits measurement error of an encoder to be calibrated without any highly accurate displacement sensor set up in an application.
However, when configuration is made in such a manner that a plurality of sensors are arranged at intervals of predetermined distance as disclosed in JP-A-2008-224578 and “Satoshi Kiyono, “Intelligent Precision Measurement”, The Japan Society for Precision Engineering, 2009, Vol. 75, No. 1, pp. 89-90”, the sampling interval of measurement error becomes equal to the pitch of arrangement of the sensors. For this reason, measurement error having a period not longer than twice as long as the arrangement pitch cannot be restored correctly, so that the frequency of measurement error allowed to be calibrated is limited.
Although it may be thought of that the pitch of arrangement of the sensors is narrowed to solve this problem, such a minimum distance that the sensors do not interfere with one another physically is required as the arrangement pitch. For this reason, narrowing the pitch of arrangement of the sensors is limited.
Moreover, use of a highly accurate displacement sensor such as a laser interferometer or preparation of a reference sensor or the like is not desirable because configuration becomes uselessly expensive. When measurement error of a non-negligible level is caused by distortion of the scale at the time of mounting or the like, it may be necessary to set up the reference displacement sensor again and a lot of cost and labor is still required.
SUMMARY
The invention is accomplished to solve such a problem and an object of the invention is to provide a displacement detecting device, a scale calibrating method and a scale calibrating program which can be formed easily and inexpensively without any laser interferometer, any reference scale, etc. so that measurement error on graduations can be calibrated accurately.
A displacement detecting device according to the invention includes: a scale which has an optical lattice; a detecting unit which is disposed so as to be movable in a scanning direction relative to the scale and which has n (n is an integer not smaller than 3) detection portions, inclusive of at least a first detection portion, a second detection portion and a third detection portion, arranged in the scanning direction for detecting position information from the optical lattice; and a calculating portion configured to obtain a self-calibration curve on graduations of the scale by specifying positions of the detection portions and calculating measurement error based on the position information detected by the detecting unit; wherein: the detecting unit is provided so that a distance between the first detection portion and the second detection portion and a distance between the second detection portion and the third detection portion are different from each other and do not form an integral multiple; and the calculating portion obtains the self-calibration curve on the graduations of the scale by repeating operation of moving the detecting unit in the scanning direction until position information detected by one of the first to third detection portions is detected by another detection portion, and calculating measurement error based on the detected position information and a distance between the detection portions which have detected the position information.
In this configuration, the sampling interval which is an interval for acquiring output data can be set to be shorter than the distance between detection portions of the detecting unit, so that a self-calibration curve having finer graduations can be obtained. Accordingly, measurement error can be corrected accurately by an inexpensive configuration.
In one embodiment of the invention, a difference of the distance between the first detection portion and the second detection portion from the distance between the second detection portion and the third detection portion is shorter than a minimum distance d in which the n detection portions can be arranged physically.
In another embodiment of the invention, the calculating portion reciprocates the detecting unit in the scanning direction and acquires the position information.
In a further embodiment of the invention, the displacement detecting device further includes: a storage unit which stores the self-calibration curve; wherein: the calculating portion corrects measurement error of the graduations by referring to the self-calibration curve stored in the storage unit.
A scale calibrating method according to the invention is a scale calibrating method in a displacement detecting device including a scale which has an optical lattice, a detecting unit which is disposed so as to be movable in a scanning direction relative to the scale and which has n (n is an integer not smaller than 3) detection portions, inclusive of at least a first detection portion, a second detection portion and a third detection portion, arranged for detecting position information from the optical lattice so that a distance between the first detection portion and the second detection portion and a distance between the second detection portion and the third detection portion are not different from each other and do not form an integral multiple, and a calculating portion configured to obtain a self-calibration curve on graduations of the scale by specifying positions of the detection portions and calculating measurement error based on the position information detected by the detecting unit, the method including: the detecting step of repeating operation of moving the detecting unit in the scanning direction until position information detected by one of the first to third detection portions is detected by another detection portion; the calculating step of obtaining the self-calibration curve on the graduations of the scale by calculating measurement error based on the detected position information and a distance between the detection portions which have detected the position information; and the correcting step of correcting the position information of the optical lattice by referring to the obtained self-calibration curve.
A scale calibrating program according to the invention is a scale calibrating program for making a computer execute a scale calibrating method in a displacement detecting device including a scale which has an optical lattice, a detecting unit which is disposed so as to be movable in a scanning direction relative to the scale and which has n (n is an integer not smaller than 3) detection portions, inclusive of at least a first detection portion, a second detection portion and a third detection portion, arranged for detecting position information from the optical lattice so that a distance between the first detection portion and the second detection portion and a distance between the second detection portion and the third detection portion are not different from each other and do not form an integral multiple, and a calculating portion configured to obtain a self-calibration curve on graduations of the scale by specifying positions of the detection portions and calculating measurement error based on the position information detected by the detecting unit, the program including: the detecting step of repeating operation of moving the detecting unit in the scanning direction until position information detected by one of the first to third detection portions is detected by another detection portion; the calculating step of obtaining the self-calibration curve on the graduations of the scale by calculating measurement error based on the detected position information and a distance between the detection portions which have detected the position information; and the correcting step of correcting the position information of the optical lattice by referring to the obtained self-calibration curve.
According to the invention, it is possible to make configuration easily and inexpensively so as to be able to calibrate measurement error on graduations of a scale accurately.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawing which is given by way of illustration only, and thus is not limitative of the present invention and wherein:
FIG. 1 is a schematic view showing a configuration of a photoelectric encoder which forms a displacement detecting device according to an embodiment of the invention.
FIG. 2 is a view for explaining a basic principle of self-calibration on graduations of a scale.
FIG. 3 is a view for explaining the basic principle.
FIG. 4 is a view for explaining a configuration of a detecting unit in the photoelectric encoder.
FIG. 5 is a view for explaining steps in the detecting unit.
FIG. 6 is a view for explaining operation based on simulation models of detecting units according to Example of the invention and Comparative Example.
FIG. 7 is a view for explaining operation based on the simulation model of the detecting unit according to Example.
FIG. 8 is a view for explaining a configuration of a detecting unit in a photoelectric encoder which forms a displacement detecting device according to another embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
A displacement detecting device, a scale calibrating method and a scale calibrating program according to embodiments of the invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a schematic view showing a configuration of a photoelectric encoder which forms a displacement detecting device according to an embodiment of the invention. As shown in FIG. 1 , the photoelectric encoder 100 has a scale 10 , a detecting unit 20 , and a calculating portion 30 . For example, the photoelectric encoder 100 is formed as a reflective type in this embodiment.
For example, the scale 10 is constituted by a tape scale and has position information for detecting positions of measurement points of detection portions (first to third detection portions) 21 , 22 and 23 which form the detecting unit 20 . The scale 10 is provided so that light irradiated from the detection portions 21 to 23 of the detecting unit 20 is reflected toward the detection portions 21 to 23 . Incidentally, n (n is an integer not smaller than 3) detection portions may be provided.
As shown in FIG. 1 , the scale 10 has a rectangular film-like board 11 , and a track 12 provided on the board 11 . The longitudinal directions of the board 11 are moving directions (scanning directions X) of the scale 10 relative to the detecting unit 20 at the time of measurement.
The track 12 is constituted by patterns 12 a . The patterns 12 a are patterns arranged at intervals of a predetermined pitch (e.g. in the order of μm) along the scanning directions X so that bright portions or dark portions are arranged periodically.
The detecting unit 20 is formed so that the detecting unit 20 can be moved in the scanning directions X relative to the scale 10 . The respective detection portions 21 to 23 detect position information from the scale 10 . For example, the respective detection portions 21 to 23 are arranged so that the distance between a measurement point of the first detection portion 21 and a measurement point of the second detection portion 22 is the minimum physically allocable distance d, and the distance between a measurement point of the second detection portion 22 and a measurement point of the third detection portion 23 is a distance α i d (α i (i=2, 3, . . . , n−1)) larger than the minimum distance d. Incidentally, α i is a non-integer constant larger than 1.
Specifically, the respective detection portions 21 to 23 irradiate light onto the scale 10 (track 12 ) and receive the light reflected from the scale 10 . The detecting unit 20 detects position information of measurement points of the respective detection portions 21 to 23 based on the light received by the respective detection portions 21 to 23 .
The calculating portion 30 specifies the positions of the measurement points of the respective detection portions 21 to 23 based on the detected position information. The calculating portion 30 calculates measurement error on graduations of the scale 10 detected by the respective detection portions 21 to 23 and obtains a precision curve (self-calibration curve). For example, the calculating portion 30 is constituted by a built-in CPU of a computer which stores the obtained self-calibration curve in a storage portion 31 , reads a scale calibrating program from the storage portion 31 and executes the program to thereby perform a process of correcting measurement error on the graduations of the scale 10 or achieve various kinds of operations, for example, by referring to the self-calibration curve.
FIGS. 2 and 3 are views for explaining a basic principle of self-calibration on graduations of the scale. As shown in FIG. 2 , a detecting unit 200 having a detection portion 201 and a detection portion 202 disposed side by side along a scale 209 having pitch displacement due to distortion is prepared first. For example, the distance between measurement points of the detection portions 201 and 202 is set as d, and the outputs of the detection portions 201 and 202 are set as m 1 (x) and m 2 (x) respectively. Assuming now that f(x) is measurement error, then the output m 1 (x) is given as m 1 (x)=x+f (x) and the output m 2 (x) is given as m 2 (x)=(x+d)+f (x+d).
For measurement, the detecting unit 200 is moved (stepwise) at intervals of a predetermined pitch along a scanning direction X, and the outputs m 1 (x) and m 2 (x) of the detection portions 201 and 202 are sampled stepwise. When the number of steps required for scanning the whole length of the scale 209 is n and the amount of each step given to the detecting unit 200 is D STEP , the outputs m 1 (D STEP ·i) and m 2 (D STEP ·i) of the detection portions 201 and 202 at the i-th step (i=0, 1, . . . , n) are given by the following expressions (1) and (2) respectively.
[Numeral 1]
m 1 ( D STEP ·i )= D STEP ·i+f ( D STEP ·i ) (1)
[Numeral 2]
m 2 ( D STEP ·i )= D STEP ·i+d+f ( D STEP ·i+d ) (2)
Accordingly, it is found that the output m 2 (D STEP ·i) has an offset of d compared with the output m i (D STEP ·i). Incidentally, the distance d between measurement points of the detection portions 201 and 202 needs to be obtained by some method in advance.
When the detecting unit 200 is moved stepwise in one (e.g. in a rightward direction in the drawing) of the scanning directions X, the amount of each step is controlled so that the output m 1 (D STEP ) of the detection portion 201 disposed on the rear side in the moving direction is aligned with the output m 2 (0) of the detection portion 202 disposed on the one-step preceding side in the moving direction as shown in FIG. 3 . On this occasion, the distance d between measurement points of the detection portions 201 and 202 is known. Accordingly, when the output of the detection portion 201 becomes equal to the output of the detection portion 202 at the preceding step, the amount of each step becomes equal to the distance d between the measurement points so that the following expression (3) is established.
[Numeral 3]
D STEP =d (3)
Incidentally, when the detecting unit 200 is moved first stepwise (in the case of i=1), it is necessary to align the output of the detection portion 201 with the output of the detection portion 202 at the initial position. Accordingly, it is desirable that the scale 209 is an absolute scale but the scale 209 may be an incremental scale according to the position information detecting method.
Measurement error f (d·i) at the i-th step (i=0, 1, . . . , n) can be expressed as the following expression (4) in accordance with the aforementioned expressions (1) and (3).
[Numeral 4]
f ( d·i )= m 1 ( d·i )− d·i (4)
In the aforementioned expression (4), measurement error is calculated based on the output of the detection portion 201 while the sampling position is used as a measurement reference. When the output of the detection portion 201 is acquired and the aforementioned expression (4) is calculated based on the output after each step is completed, measurement error f (d·i) on the whole length of the scale 209 can be obtained and a self-calibration curve based on the measurement error f(d·i) can be obtained.
Although improvement in accuracy of the encoder can be attained when this self-calibration curve is used for correcting graduations of the scale 209 , it is impossible to calibrate measurement error of higher-frequency highly accurate graduations by the configuration of the aforementioned basic principle because reduction in the distance d between measurement points is limited. Accordingly, the displacement detecting device according to this embodiment uses the detecting unit 20 having at least three detection portions for performing self-calibration as follows.
FIG. 4 is a view for explaining the configuration of the detecting unit in the photoelectric encoder. FIG. 5 is a view for explaining steps in the detecting unit. Although the detecting unit 20 shown in FIG. 1 is formed to have the first to third detection portions 21 to 23 , the detecting unit 20 can be formed to have a larger number of detection portions. Accordingly, description will be made here on the assumption that the detecting unit 20 has n (n is an integer not smaller than 3) detection portions.
As shown in FIG. 4 , the detecting unit 20 has n detection portions, that is, first to n-th detection portions 21 to n. The distances between measurement points of the respective detection portions are set as d, α 2 d, α 3 d, . . . , α n−1 d in view from the first detection portion 21 to the n-th detection portion. α i is a non-integer constant larger than 1 and is calculated in advance.
First, output data at measurement points of the respective detection portions 21 to n at an initial position are acquired. Then, output data at measurement points in the first step are acquired in such a manner that the detecting unit 20 is moved stepwise in the scanning direction X while the amount of each step is controlled based on the output data acquired at the initial position so that, for example, the output at the measurement point of the first detection portion 21 at the first step is aligned with the output at the measurement point of the second detection portion 22 at the initial position.
Then, output data at measurement points in the second step are acquired in such a manner that the detecting unit 20 is moved stepwise likewise while the amount of each step is controlled based on the output data acquired at the first step so that, for example, the output at the measurement point of the first detection portion 21 at the second step is aligned with the output at the measurement point of the second detection portion 22 at the first step.
Output data at measurement points in the third step are further acquired in such a manner that the detecting unit 20 is moved stepwise likewise while the amount of each step is controlled based on the output data acquired at the initial position so that, for example, the output at the measurement point of the first detection portion 21 at the third step is aligned with the output at the measurement point of the third detection portion 23 at the initial position.
When the detecting unit 20 is moved stepwise while the amount of each step is controlled based on the output data acquired at the measurement points of the second to n-th detection portions 22 to n in accordance with each step so that, for example, the output at the measurement point of the first detection portion 21 is aligned with those at the measurement points of the second to n-th detection portions 22 to n in this manner, a region in which the sampling interval is shorter than the distance d (e.g. the interval (α 2 −1)·d<d) appears.
Moreover, when the aforementioned step is repeated on the whole length of the scale, a sampling interval shorter than the distance d can be obtained at random. Therefore, though configuration is made so that the distances between measurement points of the respective detection portions 21 to n are all not shorter than d, measurement error can be calculated at a sampling interval not longer than d and a self-calibration curve can be obtained to correct position information of the scale.
Although measurement references for calculating measurement error are sampling positions, all the sampling positions can be calculated back based on the known measurement point distances d to α n−1 d. In this manner, the displacement detecting device according to this embodiment can be formed without any expensive configuration so that measurement error of graduations can be calibrated easily, inexpensively and accurately.
The aforementioned configuration will be described below specifically according to Example. FIG. 6 is a view for explaining operation based on simulation models of detecting units according to Example of the invention and Comparative Example. FIG. 7 is a view for explaining operation based on the simulation model of the detecting unit according to Example.
As shown in FIG. 6 , the detecting unit 20 according to Example has such three detection portions that the distance d between measurement points of the first detection portion 21 and the second detection portion 22 is set to be 10 mm and the distance α 2 d between measurement points of the second detection portion 22 and the third detection portion 23 is set to be 12.5 mm.
On the other hand, the detecting unit 20 A according to Comparative Example has such two detection portions that the distance d between measurement points of the first detection portion 21 and the second detection portion 22 is set to be 10 mm. Accordingly, the detecting unit 20 is formed so that the aforementioned parameters satisfy n=3, d=1 and α 2 =1.25 whereas the detecting unit 20 A is formed so that the aforementioned parameters satisfy n=2 and d=1.
Obtained sampling positions are simulated on 100 mm in such a manner that each detecting unit 20 or 20 A is moved stepwise so that the output at the measurement point of the first detection portion 21 is aligned with the output at the measurement points of the second and third detection portions 22 and 23 . As a result, it is obvious that the sampling interval in the detecting unit 20 according to Example is 2.5 mm from the moving region after 60 mm whereas the sampling interval in the detecting unit 20 A according to Comparative Example is 10 mm on the whole region.
This indicates that the sampling interval in Example is one fourth as long as the sampling interval in Comparative Example. That is, this indicates that measurement error can be calculated at sampling intervals of 10 mm or shorter even if the distance between measurement points is 10 mm or longer. Accordingly, measurement error of graduations can be calibrated accurately compared with Comparative Example.
Incidentally, in the example shown in FIG. 6 , the sampling interval in Example is not always 2.5 mm in the moving region of 0 to 60 mm. Accordingly, it is obvious that higher accuracy can be further attained. It is therefore desirable that configuration is made in such a manner that the detecting unit 20 is reciprocated in the detection range of the scale 10 to add sampling positions as shown in FIG. 7 .
Specifically, sampling positions are obtained in a forward path in the aforementioned manner and sampling positions are added in a backward path in such a manner that the detecting unit 20 is moved stepwise so that, for example, the output at the measurement point of the third detection portion 23 is aligned with the outputs at the measurement points of the first and second detection portions 21 and 22 obtained in the forward path. In this manner, the sampling interval can be set to be 2.5 mm on the whole length in the detection range of the scale.
Although the embodiment of the invention has been described above, the invention is not limited thereto but various changes, additions, etc. may be made without departing from the gist of the invention. For example, the photoelectric encoder may be a linear type or a rotary type. As shown in FIG. 8 , at least three detection portions 21 , 22 and 23 of the detecting unit 20 may be made of one photo acceptance element array separated into at least three photo acceptance regions so that, for example, distances d to α n−1 d (d and α 2 d in FIG. 8 ) between measurement points are formed as described above. Further, the invention can be applied not only to an incremental scale having a periodic optical lattice but also to an absolute scale having a pseudo-random code pattern and a multi-track scale having both or either of these scales.
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A displacement detecting device includes: a scale which has an optical lattice; a detecting unit which is disposed so as to be movable in a scanning direction relative to the scale, inclusive of at least a first detection portion, a second detection portion and a third detection portion, arranged in the scanning direction for detecting position information from the optical lattice; and a calculating portion configured to obtain a self-calibration curve on graduations of the scale by specifying positions of the detection portions and calculating measurement error based on the position information detected by the detecting unit, wherein: the detecting unit is provided so that a distance between the first detection portion and the second detection portion and a distance between the second detection portion and the third detection portion are different from each other and do not form an integral multiple.
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BACKGROUND OF THE INVENTION
The present invention relates generally to the feed mixing art and more specifically to an improved feed dispenser for conveying mixed feed from a mixing hopper to a cattle feeder.
The feed mixing art has developed from agricultural and biological studies which have indicated that a properly balanced diet is necessary in cattle feeding for optimum weight gain and improved meat texture. Accordingly, it has been necessary to mix various natural grains with additional nutrients, fortifiers, vitamins and minerals to formulate a uniformly dispersed mixed feed. Various mechanical means have been developed for accomplishing this purpose. Some feed mixers of the prior art have been mounted on a truck bed in order to utilize a single mobile apparatus, both for mixing the feed and for transporting it to the point of consumption, the feed lot. Upon transporting the mixed feed to the feed lot it is then necessary to dispense a controlled amount of mixed feed into the cattle feeders. Presently, the approach to cattle feeding technology is to maintain each steer being fed within a confined area for maximum efficiency of growth rate and optimum meat texture. That confinement has necessitated the use of individual feeders, as the cattle may not freely roam to feed from a communal feeder. In those circumstances, efficient and automatic dispensing of the mixed feed becomes especially important.
In the prior art, several different mechanized feed dispensers for use in connection with a mobile feed mixer have been developed. However, certain difficulties have been associated with such prior art feed dispensers. In some cases an excessive amount of manual control has been necessary for efficient dispensing of the feed. The design of other feed dispensers of the prior art has made them suitable for feed dispensing, but unsuitable for use in connection with a mobile feed mixer, which has limited their usefulness.
Accordingly, it is an object of the improved feed dispenser apparatus of the present invention materially to alleviate the difficulties associated with the prior art devices.
It is an additional object of the improved feed dispenser apparatus of the present invention to provide for a maximum of automatic operation and a minimum of manual control.
It is a further object of the improved feed dispenser apparatus of the present invention to provide means for automatically communicating the feed mixing hopper with an auger drive and for automatically extending a feed spout for directing the flow of feed into the cattle feeders.
SUMMARY OF THE INVENTION
The improved feed dispenser apparatus of the present invention includes an auger drive communicating with the discharge opening of the accompanying mixing hopper, which hopper is preferably mounted on a truck bed for transportation. The auger is contained within a trough to channel the feed upwardly from the hopper to dispense a controlled amount of feed to the cattle feeders. A slideably disposed outlet door separates the discharge opening of the mixing hopper from the auger when the unit is not in operation. Prior to dispensing, the outlet door is tracked upwardly by means of a bar and lever mechanism driven by a fluidic cylinder to open the mixing hopper to the augers. A retractable spout is hingedly mounted on the auger trough for covering the trough opening during transporation and for extending downwardly during dispensing to direct flow of feed into the cattle feeders. The retractable spout is equipped with an elbow hinge also driven by fluidic cylinder means to extend and retract the spout. Both the fluidic cylinders may be activated by a common switch simultaneously opening the slideable outlet door and extending the feed spout to dispense the mixed feed. Whereupon, after dispensing, the outlet door may be closed simultaneous to retraction of the feed spout prior to transportation to prevent any loss of feed.
Various modifications of the improved feed dispenser apparatus of the present invention are intended to be embodied and will become apparent to those skilled in the art from the teaching of the principles of the invention in connection with the disclosure of the specification, the claims and the drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic side elevational view of the improved feed dispenser apparatus of the present invention shown in conjunction with the accompanying truck-mounted feed mixing hopper, showing the exterior surface of the auger troughs covered by the spout in retracted disposition as for transportation;
FIG. 2 taken along line 2--2 of FIG. 1 is a side elevational view showing the details of the exterior of the auger troughs mounted upon the mixing hopper, the retractable feed spout shown in extended position, the slideable outlet door shown in its upward, operative position opening the hopper to the augers, and the fluidic cylinder and lever drive system for opening such outlet door;
FIG. 3 taken along 3--3 of FIG. 1 is a side elevational view showing the auger trough mounted on the mixing hopper, the feed spout shown in extended position, the slideable outlet door also shown in its upward position and the details of the fluidic cylinder-driven elbow hinge, which upon folding retracts the feed spout into its upward position for transportation;
FIG. 4 taken along 4--4 of FIG. 2 is a bottom view showing the lever arrangement for opening and closing the slideable outlet door in response to retraction and extension respectfully of the attached fluidic cylinder, and also showing at the left portion of FIG. 4 the spout extension and retraction mechanism; and
FIG. 5 is a perspective view showing the apparatus in conveying disposition with the outlet door raised and the feed spout extended to illustrate the relationship of the augers to the auger trough and further to illustrate more particularly the spout retraction and extension mechanism.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The improved feed dispenser apparatus of the present invention functions efficiently and automatically to convey mixed feed from a discharge opening of a mixing hopper, which is preferably mounted upon a truck bed, to cattle feeders for consumption.
In the apparatus of the present invention at least one auger communicates with such discharge opening of the mixing hopper to convey the mixed feed for discharge. Preferably, the auger is disposed at an angle between vertically and horizontally for a minimum of lateral protrusion from the truck bed to avoid striking objects during transportation. The auger is confined within an auger trough for channeling the feed upwardly in conjunction with the augers.
An outlet door is slidably disposed between the discharge opening of the mixing hopper and the auger trough, such that prior to dispensing the outlet door may slide upon its tracks upwardly to open the discharge opening to the augers for conveying the mixing feed. The slidable outlet door is driven by a pivotable lever connected to a fluidic cylinder. The lever is fulcrumed at a central portion thereof and is preferably carried by the trough wall. A bar is pivotably mounted preferably to the lower portion of the slidable outlet door and connected to one end of the lever, the other lever end driven by the fluidic cylinder, whereby retraction of the fluidic cylinder operates the centrally fulcrum lever to slide the outlet door upwardly and to open the hopper to the auger. Extension of the fluidic cylinder reciprocally functions to close the slidable outlet door.
The auger trough is equipped with a retractable spout. Preferably, the spout is hinged to a lip portion of the auger trough, for retraction to cover the auger trough as during transportation, and for extension to hinge the spout downwardly as during operation of the augers to direct the mixed feed into the cattle feeders. The retractable spout is operated by means of another fluidic cylinder attached to a centrally foldable elbow hinge. One end of the elbow hinge is pivotably secured, preferably to the external surface of the trough side portion, and the other end of the foldable elbow hinge is pivotably connected to the retractable spout. The spout is retracted upwardly to close the auger trough by means of retraction of its associated fluidic cylinder, which folds the elbow hinge to cause the spout to turn upwardly on the spout hinge. Extension of the fluidic cylinder serves to unfold the elbow hinge, whereby the spout turns on its hinges and extends downwardly for conducting feed into the cattle feeders.
In a preferred embodiment the auger trough is of truncated triangular shape in cross-section, as shown in the Figs. However, in alternative embodiments the auger trough may be concave and partially cylindrical. But in either embodiment the auger trough is closely disposed to and generally contoured to the auger through approximately 120°-180° of its transverse cross-section for efficiency of conveying.
The two fluidic cylinders driving the retractable spout and the slidable outlet door may be connected to a single control switch for simultaneously opening the outlet door and retracting the feed spout downwardly, as during dispensing feed. Preferably, the auger drive is controlled by a separate initiating control switch for selective and controlled dispensing of the mixed feed to prevent waste.
Referring now to the Figs. and FIG. 1 in particular, the improved feed dispenser apparatus of the present invention as shown generally at 10 may be preferably used in conjunction with a mobile feed mixer apparatus, such as a truck 11 having a truck bed 12 and bearing a mixing hopper 13 thereon. FIG. 1 shows the improved feed dispenser apparatus of the present invention with the spout 14 retracted into its upward position for closing the opening of the auger troughs 15,15. The embodiment shown in FIG. 1 utilizes two augers within the auger troughs 15,15; however, one auger trough or more than two auger troughs can be used in alternative embodiments within the intended spirit and scope of the present invention.
Referring now to FIG. 5 in particular, feed dispenser apparatus 10 includes augers 16,16 driven by auger power means (not shown), which augers communicate with the discharge opening 17 of the mixing hopper 13 for conveying the mixed feed upwardly on the auger troughs 15,15 to the retractable spout 14 for discharge into cattle feeders at the proximal end of augers 16,16. Auger troughs 15,15 include bottom, side, and top support portions 20,21,22. Bottom and side portions 20,21 contain at least the lower longitudinal portion of augers 16,16. In a preferred embodiment the bottom portion 20 of an auger trough 15 is in the form of a truncated triangle shape, although a partially cylindrical, concave wall may be utilized. In either case, the bottom portions 20 of auger troughs 15,15 are disposed in longitudinally spaced and closely disposed relationship to the auger for containing approximately 120°-180° of the transverse cross-section of the augers.
The auger trough bottom portion 20 has a lip 22 which carries the spout hinge 23. The spout 14 is mounted for rotation about the axis of spout hinge 23, whereby spout 14 may be extended for dispensing feed as shown in FIG. 5, or may be retracted for transportation as shown in FIG. 1. One side portion 21 of trough 15 serves as supplementary means for supporting spout 14 through the spout retraction and extension means shown generally at 24.
Referring now also to FIG. 4, top support portion 22 of auger troughs 15,15 provides the fulcrum means 25 for the outlet door opening and closing mechanism, shown generally at 26.
Referring to FIGS. 3 and 5 in particular and also to FIG. 4, feed spout retraction and extension mechanism 24 comprises an elbow hinge 27 which is foldable at a central portion 27a thereof. Elbow hinge 27 comprises two members 28,29 which are pivotably and longitudinally connected at the central portion of elbow hinge 27. One of the elbow hinge members 28 is pivotably attached at 30 to the exterior surface of auger trough side portion 21 for turning thereon. The other elbow hinge member 29 is connected by a pin 31 to side wall 14a of the feed spout 14. A fluidic cylinder 33 having a rod 34 and supply lines 35,36 is attached preferably by a U-bracket 37 to central portion 27a of elbow hinge 27. Upon extension of fluidic cylinder rod 34 elbow hinge 27 straightens, as shown in FIGS. 3 and 5. Upon retraction of fluidic cylinder rod 34, top elbow hinge member 28 is turned about its pivotable mount 30 in a clockwise direction, as illustrated, thereby to fold elbow hinge 27 and as a result to retract feed spout 14 upwardly into closed disposition.
Referring now to FIGS. 2, 4, and 5, the outlet door 40 is slideably mounted upon tracks 41 for sliding upwardly to open mixing hopper 13 to augers 16,16 and for sliding downwardly to close mixing hopper 13, such as for transportation. Outlet door 40 comprises a sheet facing 42 and may be preferably re-enforced with horizontal and vertical re-enforcing members 43,44. Vertical re-enforcing members 44 may also serve as tracking means.
As shown particularly in FIG. 4, the outlet door raising and lowering mechanism 26 comprises a fluidic cylinder 47 having a connected end pivotably mounted at 48 to a stationary means, such as for example truck bed 12 or mixing hopper 13. Fluidic cylinder 47 includes a rod 49 for extension and retraction in response to the fluid supplied by fluidic cylinder supply lines 50,51. Fluidic cylinder rod 49 is pivotably connected to a lever 52 preferably by a U-bracket 53 at pin 54. Lever 52 is fulcrummed by means of pivotable mounting 25 carried by auger trough top support portion 22. A bar 55 is pivotably mounted at the proximal end thereof at pin 56 to a lower portion of outlet door 40. The distal end of bar 55 is pivotably mounted at pin 58 to the second end of lever 52. Thus, when the fluidic cylinder rod 49 retracts, as shown in FIGS. 2, 5 and FIG. 4 in particular, lever 52 turns clockwise as illustrated, thereby to raise slideable outlet door 40 by sliding it upwardly on its tracks 41 in order to open mixing hopper 13 to augers 16,16. Conversely, when fluidic cylinder rod 49 extends, lever 52 turns about fulcrum 25 counterclockwise as illustrated, whereby outlet door 40 slides on its tracks 41 downwardly to close mixing hopper 13 to augers 16,16, as during transportation.
In a preferred embodiment both fluidic cylinders 35 and 47 for feed spout retraction and extension mechanism 24 and for the outlet door raising and lowering the mechanism 26 may be initiated by a common control switch for simultaneous and synchronous operation. Preferably, the drive to the augers (not shown) may be initiated by a separate control switch in order that the flow of feed from troughs 15,15 to spout 14 and downwardly into the cattle feeders may be selectively controlled both as to periodicity, duration and quantity of dispensing.
The materials used are preferably 1/4 inch steel, for strength and durability. No particular criticality is attached to specific dimensions and the improved feed mixer of the present invention may be constructed in a wide variety of sizes and shapes for optimum efficiency in conjunction with the various sizes of mixing hoppers.
The basic and novel characteristics of the improved feed dispenser apparatus of the present invention and the advantages thereof will be readily understood from the foregoing disclosure by those skilled in the art. It will become readily apparent that various changes and modifications may be made in the form, construction and arrangement of the combination apparatus set forth hereinabove without departing from the spirit and scope of the invention. Accordingly, the preferred and alternative embodiments of the present invention set forth hereinabove are not intended to limit such spirit and scope in any way.
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An improved feed dispenser for conveying mixed feed from a discharge opening of a mixing hopper and for directing the flow of feed exiting the dispenser, said dispenser including a trough contoured to an auger; a slideably disposed outlet door between the mixing hopper and the trough; a retractable, hingedly disposed spout for directing the flow of feed during dispensing and for closing the trough at other times to prevent feed loss; and fluidic cylinder operated lever structure for simultaneously sliding the outlet door to open the flow of feed to be engaged by the auger and for lowering the spout for directing the flow of mixed feed from the trough.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Divisional of U.S. patent application Ser. No. 09/766,347, filed on Jan. 19, 2001, now pending, the disclosure of which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to phototherapy using novel organic azide compounds.
BACKGROUND OF THE INVENTION
[0003] The use of visible and near-infrared (NIR) light in clinical practice is growing rapidly. Compounds absorbing or emitting light in the visible or near infrared (NIR), or long-wavelength (UV-A, >350 nm) region of the electromagnetic spectrum are potentially useful for optical tomographic imaging, endoscopic visualization, and phototherapy. However, a major advantage of biomedical optics lies in its therapeutic potential. Phototherapy has been demonstrated to be a safe and effective procedure for the treatment of various surface lesions, both external and internal. Its efficacy is akin to radiotherapy, but without the harmful radiotoxicity to critical non-target organs.
[0004] Phototherapy has been in existence for many centuries and has been used to treat various skin surface ailments. As early as 1400 B.C. in India, plant extracts (psoralens), in combination with sunlight, were used to treat vitiligo. In 1903, Von Tappeiner and Jesionek used eosin as a photosensitizer for treating skin cancer, lupus of the skin, and condylomata of female genitalia. Over the years, the combination of psoralens and ultraviolet A (low-energy) radiation has been used to treat a wide variety of dermatological diseases including psoriasis, parapsoriasis, cutaneous T-cell lymphoma, eczema, vitiligo, areata, and neonatal bilirubinemia. Although the potential of cancer phototherapy has been recognized since the early 1900's, systematic studies to demonstrate safety and efficacy began only in 1967 with the treatment of breast carcinoma. In 1975, Dougherty et al. conclusively established that long-term cure is possible with photodynamic therapy (PDT). Currently, phototherapeutic methods are also being investigated for the treatment of some cardiovascular disorders such as atherosclerosis and vascular restenosis, for the treatment of rheumatoid arthritis, and for the treatment of some inflammatory diseases such as Chron's disease.
[0005] Phototherapeutic procedures require photosensitizers (i.e. chromophores) having high absorptivity. These compounds should preferably be chemically inert, and become activated only upon irradiation with light of an appropriate wavelength. Selective tissue injury can be induced with light when photosensitizers bind to the target tissues, either directly or through attachment to a bioactive carrier. Furthermore, if the photosensitizer is also a chemotherapeutic agent (e.g., anthracycline antitumor agents), then an enhanced therapeutic effect can be attained.
[0006] Effective phototherapeutic agents require the following: (a) large molar extinction coefficients, (b) long triplet lifetimes, (c) high yields of singlet oxygen and/or other reactive intermediates, viz., free radicals, nitrenes, carbenes, or open-shell ionic species such as cabonium ions and the like, (d) efficient energy or electron transfer to cellular components, (e) low tendency for aggregation in an aqueous milieu, (f) efficient and selective targeting of lesions, (g) rapid clearance from the blood and non-target tissues, (h) low systemic toxicity, and (i) lack of mutagenicity.
[0007] Photosensitizers operate via two distinct mechanisms, termed Types 1 and 2. Type 1 mechanisms are shown in the following scheme:
[0008] Type 1 mechanisms involve direct energy or electron transfer from the photosensitizer to the cellular components thereby causing cell death. Type 2 mechanisms involve two distinct steps, as shown in the following scheme:
[0009] In the first step, singlet oxygen is generated by energy transfer from the triplet excited state of the photosensitizer to the oxygen molecules surrounding the tissues. In the second step, collision of singlet oxygen with the tissues promotes tissue damage. In both Type 1 and Type 2 mechanisms, the photoreaction proceeds via the lowest triplet state of the sensitizer. Hence, a relatively long triplet lifetime is required for effective phototherapy, whereas a relatively short triplet lifetime is required to avoid photodamage for photodiagnostics.
[0010] The biological basis of tissue injury brought about by tumor phototherapeutic agents has been the subject of intensive study. Various biochemical mechanisms for this tissue injury have been postulated based on the very limited number of photosensitizers studied. These biochemical mechanisms are as follows: a) cancer cells upregulate the expression of low density lipoprotein (LDL) receptors, and photodynamic therapy (PDT) agents bind to LDL and albumin selectively; (b) porphyrin-like substances are selectively taken up by proliferative neovasculature; (c) tumors often contain increased number of lipid bodies and are thus able to bind to hydrophobic photosensitizers; (d) a combination of ‘leaky’ tumor vasculature and reduced lymphatic drainage causes porphyrin accumulation; (e) tumor cells may have increased capabilities for phagocytosis or pinocytosis of porphyrin aggregates; (f) tumor associated macrophages may be largely responsible for the concentration of photosensitizers in tumors; and (g) cancer cells may undergo apoptosis induced by photosensitizers. Among these mechanisms, (f) and (g) are the most general and, of these two alternatives, there is a general consensus that (f) is the most likely mechanism by which the phototherapeutic effect of porphyrin-like compounds is induced.
[0011] Most of the currently known photosensitizers are commonly referred to as ‘photodynamic therapy (PDT)’ agents and operate via the Type 2 mechanism. For example, Photofrin II (a hematoporphyrin derivative) has been recently approved by the United States Food and Drug Administration for the treatment of bladder, esophageal, and late-stage lung cancers. However, Photofrin II has been shown to have several drawbacks: a low molar absorptivity (ε=3000 M −1 ), a low singlet oxygen quantum yield (φ=0.1), chemical heterogeneity, aggregation, and prolonged cutaneous photosensitivity. Hence, there has been considerable effort in developing safer and more effective photosensitizers for PDT which exhibit improved light absorbance properties, better clearance, and decreased skin photosensitivity compared to Photofrin II. These include monomeric porphyrin derivatives, corrins, cyanines, phthalocyanines, phenothiazines, rhodamines, hypocrellins, and the like. However, these phototherapeutic agents mainly operate via the Type 2 mechanism.
[0012] Surprisingly, there has not been much attention directed at developing Type 1 phototherapeutic agents, despite the fact that the Type 1 mechanism appears to be inherently more efficient than the Type 2 mechanism. First, unlike Type 2, Type 1 photosensitizers do not require oxygen for causing cellular injury. Second, the Type 1 mechanism involves two steps (photoexcitation and direct energy transfer), whereas the Type 2 mechanism involves three steps (photoexcitation, singlet oxygen generation, and energy transfer). Furthermore, certain tumors have hypoxic regions, which renders the Type 2 mechanism ineffective. However, in spite of the drawbacks associated with the Type 2 mechanism, only a small number of compounds have been developed that operate through the Type 1 mechanism, e.g. anthracylines antitumor agents.
[0013] Thus, there is a need to develop effective phototherapeutic agents that operate via the Type 1 mechanism. Phototherapeutic efficacy can be further enhanced if the excited state photosensitizers can generate reactive intermediates such as free radicals, nitrenes, carbenes, and the like, which have much longer lifetimes than the excited chromophore and have been shown to cause considerable cell injury.
SUMMARY
[0014] The present invention discloses novel, organic azide derivatives and their bioconjugates for phototherapy of tumors and other lesions. More specifically, the present invention discloses organic azide compounds having the formula:
E—L—Ar—X—N 3
[0015] N 3 is the azide moiety that produces nitrene upon photoactivation. Ar is a chromophore that undergoes sensitization. This chromophore (Ar) is an aromatic or a heteroaromatic radical derived from the group consisting of benzenes, polyfluorobenzenes, naphthalenes, naphthoquinones, anthracenes, anthraquinones, phenanthrenes, tetracenes, naphthacenediones, pyridines, quinolines, isoquinolines, indoles, isoindoles, pyrroles, imidiazoles, pyrazoles, pyrazines, purines, benzimidazoles, benzofurans, dibenzofurans, carbazoles, acridines, acridones, phenanthridines, thiophenes, benzothiophenes, dibenzothiophenes, xanthenes, xanthones, flavones, coumarins, and anthacylines. E is an epitope and is selected from the group consisting of somatostatin receptor binding molecules, ST receptor binding molecules, neurotensin receptor binding molecules, bombesin receptor binding molecules, CCK receptor binding molecules, steroid receptor binding molecules, and carbohydrate receptor binding molecules. L is a linker between the chromophore and the epitope and is selected from the group consisting of —(CH 2 ) a —, —(CH 2 ) b CONR 1 —, —N(R 2 )CO(CH 2 ) c —, —OCO(CH 2 ) d —, —(CH 2 ) e CO 2 —, —OCONH—, —OCO 2 —, —HNCONH—, —HNCSNH—, —HNNHCO—, —OSO 2 —, —NR 3 (CH 2 ) e CONR 4 —, —CONR 5 (CH 2 ) f NR 6 CO—, and —NR 7 CO(CH 2 ) g CONR 8 —. X is either a single bond or is selected from the group consisting of —(CH 2 ) h —, —OCO—, —HNCO—, —(CH 2 ) i CO—, and —(CH2) j OCO—. R 1 to R 8 are independently selected from the group consisting of hydrogen, C1-C10 alkyl, —OH, C1-C10 polyhydroxyalkyl, C1-C10 alkoxyl, C1-C10 alkoxyalkyl, —SO 3 H, —(CH 2 ) k CO 2 H, and —(CH 2 ) l NR 9 R 10 . R 9 and R 10 are independently selected from the group consisting of hydrogen, C1-C10 alkyl, C5-C10 aryl, and C1-C10 polyhydroxyalkyl. And a to l independently range from 0 to 10.
[0016] The present invention also discloses a method of performing a phototherapeutic procedure using the organic azide compounds of the present invention. This method includes the following steps. First, an effective amount of an organic azide photosensitizer having the formula
E—L—Ar—X—N 3
[0017] is administered to a subject. Ar is an aromatic or a heteroaromatic radical derived from the group consisting of benzenes, polyfluorobenzenes, naphthalenes, naphthoquinones, anthracenes, anthraquinones, phenanthrenes, tetracenes, naphthacenediones, pyridines, quinolines, isoquinolines, indoles, isoindoles, pyrroles, imidiazoles, pyrazoles, pyrazines, purines, benzimidazoles, benzofurans, dibenzofurans, carbazoles, acridines, acridones, phenanthridines, thiophenes, benzothiophenes, dibenzothiophenes, xanthenes, xanthones, flavones, coumarins, and anthacylines; E is a hydrogen atom or is selected from the group consisting of somatostatin receptor binding molecules, ST receptor binding molecules, neurotensin receptor binding molecules, bombesin receptor binding molecules, CCK receptor binding molecules, steroid receptor binding molecules, and carbohydrate receptor binding molecules; L is selected from the group consisting of —(CH 2 ) a —, —(CH 2 ) b CONR 1 —, —N(R 2 )CO(CH 2 ) c —, —OCO(CH 2 ) d —, —(CH 2 ) e CO 2 —, —OCONH—, —OCO 2 —, —HNCONH—, —HNCSNH—, —HNNHCO—, —OSO 2 —, —NR 3 (CH 2 ) e CONR 4 —, —CONR 5 (CH 2 ) f NR 6 CO—, and —NR 7 CO(CH 2 ) g CONR 8 —; X is either a single bond or is selected from the group consisting of —(CH2) h —, —OCO—, —HNCO—, —(CH 2 ) i CO—, and —(CH 2 ) j OCO—; R 1 to R 8 are independently selected from the group consisting of hydrogen, C1-C10 alkyl, —OH, C1-C10 polyhydroxyalkyl, C1-C10 alkoxyl, C1-C10 alkoxyalkyl, —SO 3 H, —(CH 2 ) k CO 2 H, and —(CH 2 ) l NR 9 R 10 ; R 9 and R 10 are independently selected from the group consisting of hydrogen, C1-C10 alkyl, C5-C10 aryl, and C1-C10 polyhydroxyalkyl; and a to l independently range from 0 to 10. Second, the photosensitizer is allowed to accumulate in target tissue. Finally, the target tissues are exposed to light of wavelength between 300 and 950 nm with sufficient power and fluence rate to perform the procedure.
[0018] In the process outlined above, the photoexcitation of the aromatic chromophore effects a rapid intramolecular energy transfer to the azido group, resulting in bond rupture and production of nitrene and nitrogen gas. The nitrogen that is released is in a vibrationally excited state, which may cause additional cellular injury.
[0019] For targeting purposes, external attachment of an epitope is used. If the aromatic azido compounds themselves preferentially accumulate in the target tissue, however, an additional binding group may not be needed. For example, if Ar is an anthracycline moiety, it will bind to cancer cells directly and not require an epitope for targeting purposes.
[0020] These and other advantages and embodiments of the inventive compounds and methods will be apparent in light of the following figures, description, and examples.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] [0021]FIG. 1 is a schematic pathway for activation of the inventive compounds.
[0022] [0022]FIG. 2 is a schematic pathway for the synthesis of a tetrafluorophenylazide derivative.
[0023] [0023]FIG. 3 is a schematic pathway for the synthesis of an acridone derivative.
[0024] [0024]FIG. 4 is a schematic pathway for the synthesis of an azidoxanthone derivative.
[0025] [0025]FIG. 5 is a schematic pathway for the synthesis of an azidoanthraquinone derivative.
[0026] [0026]FIG. 6 is a schematic pathway for the synthesis of an azidophenanthridene derivative.
[0027] [0027]FIG. 7 is a schematic pathway for a steroid-photosensitizer conjugate.
[0028] [0028]FIG. 8 is a schematic pathway for a photosensitizer attached to a biosynthetic intermediate.
DETAILED DESCRIPTION
[0029] The invention discloses novel organic azide derivatives and their bioconjugates for phototherapy of tumors and other lesions. The compounds have the general formula:
E—L—Ar—X—N 3
[0030] wherein Ar is an aromatic or a heteroaromatic radical derived from the group consisting of benzenes, polyfluorobenzenes, naphthalenes, naphthoquinones, anthracenes, anthraquinones, phenanthrenes, tetracenes, naphthacenediones, pyridines, quinolines, isoquinolines, indoles, isoindoles, pyrroles, imidiazoles, pyrazoles, pyrazines, purines, benzimidazoles, benzofurans, dibenzofurans, carbazoles, acridines, acridones, phenanthridines, thiophenes, benzothiophenes, dibenzothiophenes, xanthenes, xanthones, flavones, coumarins, and anthacylines; E is either a hydrogen atom or is selected from the group comprising antibodies, peptides, peptidomimetics, carbohydrates, glycomimetics, drugs, hormones, or nucleic acids; L is a linker unit selected from the group comprising —(CH 2 ) a —, —(CH 2 ) b CONR 1 —, —N(R 2 )CO(CH 2 ) c —, —OCO(CH 2 ) d —, —(CH 2 ) e CO 2 —, —OCONH—, —OCO 2 —, —HNCONH—, —HNCSNH—, —HNNHCO—, —OSO 2 —, —NR 3 (CH 2 ) e CONR 4 —, —CONR 5 (CH 2 ) f NR 6 CO—, and —NR 7 CO(CH 2 ) g CONR 8 —; X is either a single bond or is selected from the group consisting of —(CH 2 ) h —, —CO—, —OCO—, —HNCO—, —(CH 2 ) i CO—, and —(CH 2 ) j OCO—; R 1 to R 8 are independently selected from the group consisting of hydrogen, C1-C10 alkyl, —OH, C1-C10 polyhydroxyalkyl, C1-C10 alkoxyl, C1-C10 alkoxyalkyl, —SO 3 H, —(CH 2 ) k CO 2 H, or —(CH 2 ) l NR 9 R 10 ; R 9 and R 10 are independently selected from the group consisting of hydrogen, C1-C10 alkyl, C5-C10 aryl, or C1-C10 polyhydroxyalkyl; and a to l independently range from 0 to 10.
[0031] In a first embodiment, azides according to the present invention have the general formula shown above wherein Ar is an aromatic radical derived from the group consisting of benzenes, polyfluorobenzenes, anthracenes, anthraquinones, naphthacenediones, quinolines, isoquinolines, indoles, acridines, acridones, phenanthridines, xanthenes, xanthones, and anthacylines; E is selected from the group consisting of somatostatin receptor binding molecules, ST receptor binding molecules, neurotensin receptor binding molecules, bombesin receptor binding molecules, cholecystekinin receptor binding molecule, steroid receptor binding molecules, and carbohydrate receptor binding molecules; L is selected from the group consisting of —HNCO—, —CONR 1 —, —HNCONH—, —HNCSNH—, —HNNHCO—, —(CH 2 ) a CONR 1 —, —CONR 1 (CH 2 ) a NR 2 CO—, and —NR 1 CO(CH 2 ) a CONR 2 —; R 1 and R 2 are independently selected from the group consisting of hydrogen, C1-C10 alkyl, C1-C10 polyhydroxyalkyl; and a, b, and c independently range from 0 to 6.
[0032] In a second embodiment, azides according to the present invention have the general formula shown above wherein Ar is selected from the group consisting of tetrafluorobenzenes, phenanthridines, xanthones, anthraquinones, acridines, and acridones; E is a selected from the group consisting of octreotide and octreotate peptides, heat-sensitive bacterioendotoxin receptor binding peptides, carcinoembryonic antigen antibody (anti-CEA), bombesin receptor binding peptide, neurotensin receptor binding peptide, cholecystekinin receptor binding peptide, and estrogen steroids; L is selected from the group consisting of —HNCO—, —CONR 1 —, —HNCSNH—, —HNNHCO—, —(CH 2 ) a CONR 1 —, —CONR 1 (CH 2 ) a NR 2 CO—; and R 1 and R 2 are independently selected from the group consisting of hydrogen, C1-C10 alkyl, C1-C5 polyhydroxyalkyl; and a, b, and c independently range from 0 to 6.
[0033] These compounds operate mainly by a Type I mechanism as shown in FIG. 1. In the compounds according to the present invention, N 3 is the azide moiety that produces nitrene upon photoactivation, and Ar is an aromatic chromophore that undergoes photosensitization. Aliphatic azido compounds can also be used for phototherapy, but may require high-energy light for activation unless the azide moiety is attached to conjugated polyene system. L is a linker between the chromophore and the epitope. Epitope (E) is a particular region of the molecule that is recognized by, and binds to, the target surface. An epitope is usually, but not always, associated with biomolecules which include hormones, amino acids, peptides, peptidomimetics, proteins, nucleosides, nucleotides, nucleic acids, enzymes, carbohydrates, glycomimetics, lipids, albumins, mono- and polyclonal antibodies, receptors, inclusion compounds such as cyclodextrins, and receptor binding molecules. Specific examples of biomolecules include steroid hormones for the treatment of breast and prostate lesions, somatostatin, bombesin, and neurotensin receptor binding molecules for the treatment of neuroendocrine tumors, cholecystekinin receptor binding molecules for the treatment of lung cancer, heat sensitive bacterioendotoxin (ST) receptor and carcinoembryonic antigen (CEA) binding molecules for the treatment of colorectal cancer, dihyroxyindolecarboxylic acid and other melanin producing biosynthetic intermediates for melanoma, integrin receptor and atheroscleratic plaque binding molecules for the treatment of vascular diseases, and amyloid plaque binding molecules for the treatment of brain lesions. Examples of synthetic polymers include polyaminoacids, polyols, polyamines, polyacids, oligonucleotides, aborols, dendrimers, and aptamers.
[0034] Coupling of diagnostic and radiotherapeutic agents to biomolecules can be accomplished by methods well known in the art, as disclosed in Hnatowich et al., Radiolabeling of Antibodies: A simple and efficient method. Science , 1983, 220, 613; A. Pelegrin et al., Photoimmunodiagnostics with antibody-fluorescein conjugates: in vitro and in vivo preclinical studies. Journal of Cellular Pharmacology , 1992, 3, 141-145, and U.S. Pat. No. 5,714,342, which are expressly incorporated by reference herein in their entirety. Successful specific targeting of fluorescent dyes to tumors using antibodies and peptides for diagnostic imaging of tumors has been demonstrated by us and others, for example, S. A. Achilefu et al., Novel receptor-targeted fluorescent contrast agents for in vivo imaging of tumors. Investigative Radiology , 2000, 35(8), 479-485; B. Ballou et al., Tumor labeling in vivo using cyanine-conjugated monoclonal antibodies. Cancer Immunology and Immunotherapy , 1995, 41, 257-263; K. Licha et al., New contrast agent for optical imaging: acid-cleavable conjugates of cyanine dyes with biomolecules. In Biomedical Imaging: Reporters, Dyes, and Instrumentation, D. J. Bornhop, C. Contag, and E. M. Sevick-Muraca ( Eds .), Proceedings of SPIE , 1999, 3600, 29-35, which are expressly incorporated by reference herein in their entirety. Therefore, the inventive receptor-targeted phototherapeutic agents are expected to be effective in the treatment of various lesions.
[0035] In the process outlined in FIG. 1, the photoexcitation of the aromatic chromophore effects rapid intramolecular energy transfer to the azido group, resulting in bond rupture and production of nitrene and nitrogen gas. The nitrogen that is released is in a vibrationally excited state, which may cause additional cellular injury.
[0036] For targeting purposes, external attachment of an epitope is used. If the aromatic azido compounds themselves preferentially accumulate in the target tissue, however, an additional binding group may not be needed. For example, if Ar is an anthracycline moiety, it will bind to cancer cells directly and not require an epitope for targeting purposes.
[0037] The synthesis of azido compounds is accomplished by a variety of methods known in the art, such as disclosed in S. R. Sandier and W. Karo, Azides. In Organic Functional Group Preparations ( Second Edition ), pp. 323-349, Academic Press: New York, 1986, which is expressly incorporated by reference herein in its entirety. Aromatic azides derived from acridone, xanthone, anthraquinone, phenanthridine, and tetrafluorophenyl systems have been shown to photolyze in the visible and in UV-A regions, for example, L. K. Dyall and J. A. Ferguson, Pyrolysis of aryl azides. XI Enhanced neighbouring group effects of carbonyl in a locked conformation. Australian Journal of Chemistry , 1992, 45, 1991-2002; A. Y. Kolendo, Unusual product in the photolysate of 2-azidoxanthone. Chemistry of Heterocyclic Compounds , 1998, 34(10), 1216; R. Theiler, Effect of infrared and visible light on 2-azidoanthraquinone in the QA binding site of photosynthetic reaction centers. An unusual mode of activation of photoaffinity label. Biological Chemistry Hoppe - Seyler , 1986, 367(12), 1197-207; C. E. Cantrell and K. L. Yielding, Repair synthesis in human lymphocytes provoked by photolysis of ethidium azide. Photochemistry and Photobiology , 1977, 25(2), 1889-191; and R. S. Pandurangi et al., Chemistry of bifunctional photoprobes 3: correlation between the efficiency of CH insertion by photolabile chelating agents. First example of photochemical attachment of 99 mTc complex with human serum albumin. Journal of Organic Chemistry , 1998, 63, 9019-9030, each of which is expressly incorporated by reference herein in its entirety. The inventive azide derivatives contain additional functionalities that can be used to attach various types of biomolecules, synthetic polymers, and organized aggregates for selective delivery to various organs or tissues of interest. Preparations of representative compounds from the preferred embodiment are outlined in FIGS. 2-5.
[0038] A typical preparation of a tetrafluorophenylazide derivative is shown in FIG. 2. Methyl 2,3,4,5,6-pentafluorophenylbenzoate is reacted with sodium azide in aqueous acetone, and the resulting azidoester is saponified with sodium hydroxide to give 4-azido-2,3,5,6-tetrafluorobenzoic acid. The azidoacid is then converted to the corresponding active ester using N-hydroxysuccimide (NHS) and dicyclohexylcarbodiimide (DCC). The active ester can be attached to any desired biomolecule of interest. Specifically, the biomolecules bind to colorectal, cervical, ovarian, lung, and neuroendocrine tumors, and include somatostatin, cholesystekinin, bombesin, neuroendrocrine, and ST receptor binding compounds.
[0039] An acridone derivative is prepared according to FIG. 3. The starting aminoacridone is converted to the azide by a standard method of diazotization of the amino group and displacement of the diazonium group with sodium azide, as disclosed in K. Matsumura, 1-Aminoacridine-4-carboxylic acid. Journal of the American Chemical Society , 1938, 32, 591-592, which is expressly incorporated by reference herein in its entirety. The azide is then conjugated to the biomolecules directly using an automated peptide synthesizer, or indirectly by the active ester route.
[0040] A typical preparation of an azidoxanthone derivative is outlined in FIG. 4. The acid chloride is reacted with the lactone under Friedel-Crafts conditions to give the benzophenone intermediate, which is saponified and cyclized at once to the nitroxanthone. The nitro group is then converted to the azide by a standard sequence of reactions, that is, reduction, diazotization, and sodium azide treatment. The lactone ring should be sufficiently reactive for conjugation to biomolecules mentioned previously.
[0041] Azidoanthraquinone derivatives can be synthesized according to FIG. 5. The diacid chloride is reacted with the lactone under Friedel-Crafts conditions to the corresponding nitroanthraquinone. The nitrogroup is then converted to the azido group by the standard procedure previously described. The lactone ring is sufficiently reactive for conjugation to the desired biomolecule or, alternatively, it could be hydrolyzed to the acid and then coupled to the biomolecule by conventional methods.
[0042] The azidophenanthridene derivatives can be prepared according to FIG. 6. Preparation of the starting material, ethidium azide, has been described in C. E. Cantrell and K. L. Yielding, Binding of ethidium monoazide to the chromatin in human lymphocytes. Biochimica and Biophyica Acta , 1980, 609(1), 173-179, which is expressly incorporated by reference herein in its entirety. The amino group can be activated in several ways. In particular, it can be converted to an isothiocyanate derivative using thiocarbonyl diimidazole or thiophosgene, or it can also be directly condensed with a biomolecule using disuccinimidyl carbonate or carbonyl diimidazole.
[0043] The novel compositions of the present invention may vary widely depending on the contemplated application. For tumors, the biomolecule is selected from the class of tumor markers including, but not limited to, somatostatin, bombesin, neurotensin, cholesytekinin, ST, estrogen, and progesterone receptor binding compounds. For vascular lesions, the biomolecule may be selected from the class of integrins, selectins, vascular endothelial growth factor, fibrins, tissue plasminogen activator, thrombin, LDL, HDL, Sialyl Lewis x and its mimics, and atherosclerotic plaque binding compounds. A typical synthetic scheme of a steroid-photosensitizer conjugate is shown in FIG. 7.
[0044] As previously discussed, some compounds accumulate in tumors or other lesions without the assistance of a bioactive carrier. Administration of δ-aminolevulinic acid, an intermediate in porphyrin biosynthesis, results in a two-fold uptake of porphyrins in tumors compared to normal tissues. Similarly, administration of dihydroxyindole-2-carboxylic acid, an intermediate in melanin biosynthesis, produces substantially enhanced levels of melanin in melanoma cells compared to normal cells. Thus, a photosensitizer may be delivered to the site of lesion by attaching it to a biosynthetic intermediate, as shown in FIG. 8.
[0045] Methods of performing therapeutic procedures with the inventive compositions are also disclosed. An effective amount of the inventive composition in a pharmaceutically acceptable formulation is administered to a patient. The dose of the photosensitizer may vary from 0.1 to 500 mg/kg body weight, preferably from 0.5 to 2 mg/kg body weight. The photosensitizer is allowed to accumulate in the region of interest, followed by illumination with the light of wavelength 300 to 1200 nm, preferably 350 to 850 nm, at the site of the lesion. If the lesion is on the skin surface, the photosensitizer can be directly illuminated; otherwise, endoscopic catheters equipped with a light source may be employed to achieve phototherapeutic effect. The intensity, power, duration of illumination, and the wavelength of the light may vary widely depending on the location and site of the lesions. The fluence rate is preferably, but not always, kept below 200 mW/cm 2 to minimize thermal effects. Appropriate power depends on the size, depth, and the pathology of the lesion. The inventive compositions have broad clinical utility which includes, but is not limited to, phototherapy of tumors, inflammatory processes, and impaired vasculature.
[0046] The inventive compositions can be formulated into diagnostic or therapeutic compositions for enteral, parenteral, topical, cutaneous, oral, or rectal administration. Topical or cutaneous delivery of the photosensitizer may also include aerosol formulation. The compositions are administered in doses effective to achieve the desired diagnostic or therapeutic objective. Such doses may vary widely depending upon the particular complex employed, the organs or tissues to be examined, the equipment employed in the clinical procedure, and the like. These compositions contain an effective amount of the phototherapeutic agent, along with conventional pharmaceutical carriers and excipients appropriate for the type of administration contemplated. These compositions may also include stabilizing agents and skin penetration enhancing agents. For example, parenteral administration advantageously contains a sterile aqueous solution or suspension of the photosensitizer in a concentration ranging from about 1 nM to about 0.5 M. Preferred parenteral formulations have a concentration of 1 μM to 10 mM photosensitizer. Such solutions also may contain pharmaceutically acceptable buffers, emulsifiers, surfactants, and, optionally, electrolytes such as sodium chloride. Formulations for enteral administration may vary widely, as is well known in the art. In general, such formulations are liquids, which include an effective amount of the complexes in aqueous solution or suspension. Such enteral composition may optionally include buffers, surfactants, emulsifiers, thixotropic agents, and the like. Compositions for oral administration may also contain flavoring agents and other ingredients for enhancing their organoleptic qualities. Formulations for topical delivery may also contain liquid or semisolid excipients to assist in the penetration of the photosensitizer. The compositions may also be delivered in an aerosol spray.
[0047] The following example illustrates a specific embodiment of the invention pertaining to the preparation and properties of a typical bioconjugate derived from bombesin, a bioactive peptide, and a phototherapeutic molecule, 4-azido-2,3,5,6-tetrafluorophenylbenzoic acid.
EXAMPLE
Synthesis of 4-azido-2,3,5,6-tetrafluorophenvlbenzoate-bombesin (7-14) conjugate
[0048] The peptide was prepared by fluorenylmethoxycarbonyl (Fmoc) solid phase peptide synthesis strategy with a commercial peptide synthesizer from Applied Biosystems (Model 432A SYNERGY Peptide Synthesizer). The first peptide cartridge contained Wang resin pre-loaded with an amide resin on 25-μmole scale. The amino acid cartridges were placed on the peptide synthesizer and the product was synthesized from the C- to the N-terminal position. Coupling of the Fmoc-protected amino acids (75 μmol) to the resin-bound free terminal amine (25 μmol) was carried out with 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (HBTU, 75 μmol)/N-hydroxybenzotriazole (HOBt, 75 μmol). Each Fmoc protecting group on solid support was removed with 20% piperidine in dimethylformamide before the subsequent amino acid was coupled to it. The last cartridge contained 4-azido-2,3,5,6-tetrafluorobenzoic acid, which was successfully coupled to the peptide automatically, thus avoiding the need for post-synthetic manipulations.
[0049] After the synthesis was completed, the product was cleaved from the solid support with a cleavage mixture containing trifluoroacetic acid (85%):water (5%):phenol (5%):thioanisole (5%) for 6 hours. The peptide-azide conjugate was precipitated with t-butyl methyl ether and lyophilized in water:acetonitrile (2:3) mixture. The conjugate was purified by HPLC and analyzed with LC/MS, which indicated that the desired compound was obtained in 99% HPLC purity. The azido-bombesin (7-14) conjugate has the following molecular structure: p-azidotetrafluorobenzoyl-Gln-Trp-Ala-Val-Gly-His-Leu-Met-NH 2 Molecular weight (Electrospray mass spectrum): m/Z, 1358 (M+H).
[0050] As would be apparent to skilled artisans, various changes and modifications are possible and are contemplated within the scope of the invention described. Although the compositions of the present invention are primarily directed at therapy, most of the compounds containing polycyclic aromatic chromophores can also be used for optical diagnostic imaging purposes.
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The present invention discloses novel aromatic azide derivatives and their bioconjugates for phototherapy of tumors and other lesions. The organic azides of the present invention are designed to absorb low-energy ultraviolet, visible, or near-infrared (NIR) region of the electromagnetic spectrum. The phototherapeutic effect is caused by direct interaction of nitrene, the reactive intermediate produced upon photoexcitation of the aromatic azide, with the tissue of interest. The compounds of the present invention are administered to a patient, allowed to accumulate at the site of the tumor or other lesion, and are exposed to light in order to perform a phototherapeutic procedure.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] N/A
FIELD OF THE INVENTION
[0002] This invention is an x-ray irradiation system using two line-type x-ray sources and a rotating sample canister to provide an x-ray irradiation system with high sample throughput, uniform dose distribution throughout the sample canister and the ability to function during several failure modes.
BACKGROUND
[0003] Blood irradiation therapy is a procedure that is performed prior to providing patients with blood from other donors. The blood irradiation therapy is performed in two different methods. First, the blood is irradiated just prior to providing the blood to the patient in blood transfusion. The second is blood is stored in blood bags, and the blood bags are radiated and store for later use. There are many problems that are associated with blood irradiation. Irradiating blood includes whole blood, red cells, frozen cells, platelet concentrates, apheresis platelets, granulocyte concentrates, and fresh plasma. The blood can be treated with ionizing radiation such as gamma rays from 137Cs or 60Co sources, self-contained bremsstrahlung x-ray units, medical linear x-ray and electrons accelerators. The primary purpose is to inactivate viable lymphocytes to prevent transfusion-induced graft-verus-host disease (GVHD) in selected immunocompromised patients and those receiving related-donor products (ASTM 1939). The purpose of the blood irradiation is to remove the immunocompetent cells whose unwanted addition in immunodepressed patients cause a very serious and often fatal reaction of the graft. The three most common reasons for radiating the blood is to help the 1) kill diseases for aplastic patients, since the patient's body is not making enough blood cells to find off infections, 2) kill cancerous cells with patients with leukemias, lymphomas), which some individuals that donate blood may not be aware the irradiating of the blood cells stops the cancer reproducing cells in the blood, and 3) children with immune deficiency, some child may have a reaction with blood donated by the patient and reduce that reaction or disease. Therefore, it is important to irradiate the blood. Currently, there are many different types of blood bag irradiators. At present, a blood bag irradiator has two x-ray tubes placed on top and bottom of a blood bag. The problem with this is that when a tube is inactive, the dose to the blood bag irradiation is not accurate or assured. When a tube is not functioning or inoperative, the absorbed-dose rate at a reference dose position within the blood volume is not accurate that the blood bag will be consider not radiated properly. Therefore, one of ordinary skill in the art would appreciated a need to provide a system and method to irradiate the blood effectively and efficiently while performing under a x-ray source, and have a multiple redundant system to continuously irradiate blood bags.
[0004] Other problems with irradiating the blood bag is that blood bags have been irradiated for too long and thus reach a temperature too hot; which decays and ruins the blood bag. Specifically, there are many hot spots and cold spots where the blood bag is irradiated. Blood bag irradiators only turn on and off the x-ray source and then the x-rays only hits certain concentrated location on the blood bag, which results in hot and cold spots. Therefore, one of ordinary skill in the art would appreciate a need to have a system that can evenly irradiate a blood bag quickly.
SUMMARY OF INVENTION
[0005] According to one general aspect, A blood irradiator apparatus for evenly irradiating blood bags comprising a blood canister, wherein the blood canister holds a blood bag an one or more power supply; an one or more x-ray sources, wherein the one or more x-ray sources are connected individual or together to the one or more power supply; an one or more motors to rotate the blood canister; and a vault shield. In addition, the blood irradiator apparatus for evenly irradiation blood bags further states the blood canister is connected to the one or more motors, wherein, the blood canister will rotate in clock-wise or counter clock-wise motion. Also, the blood irradiator apparatus for evenly irradiation blood bags further states the blood canister is located in the center of the one or more line x-ray sources. In addition, the blood irradiator apparatus for evenly irradiation blood bags further states the blood canister changes the rotation speed conditioned on a single x-ray source or a dual x-ray source. Furthermore, the blood irradiator apparatus for evenly irradiation blood bags further states the blood canister is connected to an operator control, wherein the operator control changes a rotation speed and a rotation direction or may used predetermined settings. Moreover, the blood irradiator apparatus for evenly irradiation blood bags further states the blood canister is connected to an internal cooling system, wherein the internal cooling system cools the blood canister. Further, the blood irradiator apparatus for evenly irradiation blood bags further states the one or more x-ray sources contain an anode and a cathode. Additionally, A blood irradiator apparatus for evenly irradiation blood bags further states the anode and the cathode of a dual x-ray tubes are inverted on opposite sides used to irradiate the blood canister, wherein the dual x-ray tubes provide an even dose distribution. Likewise, the blood irradiator apparatus for evenly irradiation blood bags further states the one or more x-ray sources irradiate the entire the blood canister. Also, the blood irradiator apparatus for evenly irradiation blood bags further states the operator control contains a CPU, a touch display apparatus, and input device, wherein the operator control is connected to the blood irradiator apparatus; and the operator control monitors internal temperature of the blood irradiator apparatus. What is more, the blood irradiator apparatus for evenly irradiation blood bags further states the dual x-ray sources irradiate the blood canister while the blood canister is rotating at a predetermined speed. Further, the blood irradiator apparatus for evenly irradiation blood bags further states the blood canister is being irradiated on the coronal plano and not being irradiated on the transversal piano. Furthermore, the blood irradiator apparatus for evenly irradiation blood bags further states the one or more x-ray sources contain a line array x-ray tube.
[0006] According to another general aspect of a method of irradiating a blood bag in a uniform dose comprising spinning a blood canister in a clock-wise or counter clock-wise direction; irradiating the blood canister while spinning in a rotational direction by using a one or more line x-ray tubes; and operating an operator control and monitoring the blood canister and the one or more line x-ray tubes.
DESCRIPTION OF THE DRAWINGS
[0007] These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings were:
[0008] FIG. 1 illustrates an exemplary apparatus of a blood irradiator, but not limited to illustrated component parts.
[0009] FIG. 2 illustrates the exemplary parts of a blood irradiator, but not limited to illustrated component parts.
[0010] FIG. 3 illustrates a exemplary front view of a blood irradiator apparatus, but not limited to illustrated component parts.
[0011] FIG. 4 illustrates an exemplary capture container rotation, but not limited to illustrated component parts.
[0012] FIG. 5A illustrates an exemplary top view of the capture canister, but not limited to illustrated component parts.
[0013] FIG. 5B illustrates an exemplary side view of the capture canister, but not limited to illustrated component parts.
[0014] FIG. 6A illustrates an exemplary single source intersection points of capture canister.
[0015] FIG. 6B illustrates an exemplary dual source intersection points of capture canister.
[0016] FIG. 7 illustrates the conventional x-ray source irradiation of the blood canister.
[0017] While the invention will be described connection with the preferred embodiment, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as maybe included within the spirit and scope of the invention as to be defined by claims to be filed in a non-provisional application.
DETAILED DESCRIPTION
[0018] In the Summary of the Invention above and in the Detailed Description of the Invention, and the claims below, and in the accompanying drawings, reference is made to particular features (including method steps) of the invention. It is to be understood that the disclosure of the invention in this specification includes all possible combinations of such particular features. For example, where a particular feature is disclosed in the context of a particular aspect or embodiment of the invention, or a particular claim, that feature can also be used, to the extent possible, in combination with and/or in the context of other particular aspects and embodiments of the invention, and in the invention generally.
[0019] Where reference is made herein to a method comprising two or more defined steps, the defined steps can be carried out in any order or simultaneously (except where the context excludes that possibility), and the method can include one or more other steps which are carried out before any of the defined steps, between two of the defined steps, or after all the defined steps (except where the context excludes that possibility).
[0020] In the following description, reference is made to the accompanying drawings, which form a part hereof and which illustrate several embodiments of the present invention. The drawings and the preferred embodiments of the invention are presented with the understanding that the present invention is susceptible of embodiments in many different forms and, therefore, other embodiments may be utilized an structural and operational changes may be made without departing from the scope of the present invention.
[0021] The invention generally relates to an apparatus and method of irradiating blood bags by rotating the capture container.
[0022] FIG. 1 shows a blood bag irradiator apparatus 2 . The system, not limited to, contains a single blood bag canister 1 . The blood bag canister 1 holds a blood bag which can be sealed inside a lead shield to prevent radiation from leaking out. The system contains a display 3 and keyboard 5 , which is used to operate the device. The system can be modified to be adopted in any part of the world's power supply system and contains an outlet 7 . The system also contains an external cooling vent 9 . The display 3 and keyboard 5 are connected to a CPU which are used to operate the blood irradiation process. In addition, the operating system can be controlled manually or by used operated by pre-set functions.
[0023] Looking specifically, FIG. 2 illustrates the component parts of a blood irradiator, but not limited to illustrated component parts. Within the blood bag irradiating apparatus 2 the system contains an internal x-ray shield 11 . The x-ray shield is used to prevent radiation leakage when the blood bags are being irradiated. The irradiation chamber of the line-type x-ray source and canister will be completely enclosed with lead foil sufficiently thick enough to reduce external radiation levels to less than or equal levels established by the appropriate regulatory agency. Additionally, the shapes of the radiation field produced by line-type x-ray tubes 12 are approximate to the shape of the blood canister, which the beam does not over shoot the blood bag canister 1 . This effective use of the radiation results in much less radiation being scattered and this greatly reduces the risk associated with radiation leakage. The system will display all the information about irradiating the blood bags inside the blood bag canister. The outlet plug 17 is connected to the x-ray power supply 15 . The system generates large amount of heat; therefore, the system contains an internal cooling system 19 and also an external cooling vent 21 . The internal cooling system may be used also to cool the blood bag and the blood bag irradiating apparatus 2 . During irradiation, the blood bag temperature may increase; however, the blood bag cannot reach a certain temperature or the blood bag will spoil. Therefore, the blood bag irradiator cooling system can be used to cool the blood bag.
[0024] FIG. 3 illustrates a closer view of the blood bag canister 25 . The blood bag canister contains an internal x-ray shield 27 . The blood bag chamber 26 contains a blood bag canister 25 . Connected the blood bag canister 25 is the motor device 28 . A typical motor attached to a turntable assembly. Our configuration will have single turntable, rotating platform, and two motors. If a motor fails it will be detected by the control system and the back-up motor will come into operation. The motors and turntable and sized to work properly in a radiation rich environment.
[0025] The major benefit by having a rotating blood chamber is to reduced amount of time it will take to achieve the prescribed dose during the irradiation cycle. Since blood is temperature sensitive, the reduced irradiation or cycle time allows the blood to be returned to a temperature controlled, refrigerated, environment in less time than conventional irradiators thus eliminating a potential cause of spoilage.
[0026] FIG. 4 illustrates the blood irradiating chamber. There are many subsystems in the dual line tube configuration, which are two line x-ray tubes, if needed, two power supplies, and one or two motor to rotate the canister. This configuration allows the user to continue to irradiate blood even if there is a failure of one of the critical component. The blood bag canister is connected to a motor. The motor will be at variable speed rotation, which in turn will change the speed of the rotation platform 32 that is attached to the blood bag container 33 located in center of the chamber. While the system is active, the first x-ray 29 and the second x-ray 31 will radiate the blood bag simultaneously. The benefit of having two dual x-rays tubes allows the system to radiate the blood bag rapidly and effectively, while cooling the blood bag simultaneously. The additional benefit is that if either x-ray tube were to malfunction, the single tube would provide enough radiation which will not stop the production of the blood irradiation. The system is capable of blood irradiation with a single x-ray tube. Furthermore, by spinning the bag at different speeds, the system will allow the blood bag to be irradiated in different location evenly. The line-type x-ray source being used is a modified electron beam tube that provides a relatively large rectangular shaped radiation field approximately 4-10 cm wide and 27-35 cm high. Therefore, the blood canister will rotate during irradiation for the blood bags to achieve a uniform dose x-radiation. The line-type x-ray sources have a much longer life cycle than a conventional x-ray tube. However, a conventional x-ray tube may be also used. The conventional x-ray tube for irradiating blood bags are described below. This is understandable since the electron emitter in a line-type x-ray source is substantially longer than the filament in a fixed anode x-ray tube. Since the power requirements in both instances are approximately the same, the short repetitive x-ray exposure cycle, beam on/off, used in blood irradiation should be better tolerated by the longer electron emitter.
[0027] FIG. 5 illustrates a top and side view of the capture container. FIG. 5A is the top view illustrating that the blood canister, which is in a circular fashion; however, the shape maybe any shape that fits inside the chamber. The circular shape is only used for illustrative purposes and should not limit this apparatus. FIG. 5B is the side view of the blood canister. The blood canister contains a side wall 37 . The side wall 37 and canister cover 35 are made of uniform material so allow for equal distribution of x-rays.
[0028] Platform rotation is variable and will depend on the diameter of the canister, the kilowatt rating of the x-ray source or sources, the x-ray dose rate, and the number of sources in use. In order to assure a uniform distribution of the radiation dose being delivered to the sample, complete rotations of 360 degrees must be accomplished. An under rotation of the platform will result in under dosing portions of the sample while an over rotation will result in over dosing portions of the sample. Rotation speed is faster for 2 x-ray sources compared to a single x-ray source.
[0029] FIG. 6A illustrates a top of view of the blood canister using a single x-ray source with a rotating canister, which will work fine. The single x-ray source 39 irradiates the blood canister 42 . Adding a second line tube reduces the irradiation time by 50% and allows the user to irradiate blood if one of the x-ray tubes fails.
[0030] FIG. 6B illustrates the source intersection points of blood canister. This demonstrates the x-ray tube 41 and x-ray tube 43 provide an area were the blood canister area is radiated on both sides as the blood canister is rotating. The system first starts the rotating process to a specific speed. Thereafter, the system then turns on the x-ray tube 41 and x-ray tube 43 . The area entire blood canister area is radiated. This allows for the device to radiate the entire bag. However, if one of the x-ray tubes were to mal-function, the system will still continue to radiate the blood bag since either x-ray tube covers the blood bag canister.
[0031] The advantages over existing system are the dual two x-ray sources and redundant power supplies, with the blood canister rotating at variable speeds. Prior existing systems do not have rotational features with dual x-ray sources. Thus, if one of these component parts were to fail in prior existing systems, the user can not irradiate blood bags until the system is repaired.
[0032] FIG. 7 illustrates the inverted conventional x-ray tubes. The two opposing fixed anode x-ray tubes on opposite sides of a rotating platform aligned anode-to-cathode. Specifically, first x-ray source 45 is setup with anode 51 is on top and the cathode is 53 , which is the opposite of the second x-ray source 47 . In the second x-ray source 47 the anode 51 is on the bottom and the cathode 53 is on top. Both first x-ray source 45 and second x-ray source 47 are irradiating the blood canister 49 . By having in opposite directions, this creates an even distribution dose radiation to the blood canister.
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According to one general aspect, A blood irradiator apparatus for evenly irradiating blood bags comprising a blood canister, wherein the blood canister holds a blood bag an one or more power supply; an one or more x-ray sources, wherein the one or more x-ray sources are connected individual or together to the one or more power supply; an one or more motors to rotate the blood canister; and a vault shield. In addition, the blood irradiator apparatus for evenly irradiation blood bags further states the blood canister changes the rotation speed conditioned on a single x-ray source or a dual x-ray source. Furthermore, the blood irradiator apparatus for evenly irradiation blood bags further states the blood canister is connected to an operator control, wherein the operator control changes a rotation speed and a rotation direction or may used predetermined settings.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a travelling worktable apparatus (a sample travelling worktable apparatus or a sample stage apparatus) for semiconductor manufacturing apparatuses, semiconductor inspecting apparatuses, and working tools to achieve fine machining with high precision, and in particular, to improvement of measurement errors in measurement of a position of a sample.
[0003] 2. Description of the Related Art
[0004] In general, in semiconductor manufacturing apparatuses and/or semiconductor inspecting apparatuses, a travelling stage apparatus (travelling worktable apparatus) to transport a sample such as a wafer must have a positioning function with high precision. Therefore, a laser for high-precision measurement is usually employed to detect a sample position. In such a configuration, a position of a mirror placed on a sample table is measured by a laser to control the sample position. In the detection of the sample position according to values measured by a laser, variation in distance between the mirror (bar mirror) and the sample has been heretofore neglected. However, in an apparatus which requires higher precision in the positioning of a sample, the distance between the bar mirror and the sample varies by deformation of the table caused by a guide apparatus, for example, deviation in precision of rollers used in the guide apparatus and precision in attachment of the guide apparatus. It is consequently difficult to control the sample position with high precision.
[0005] Referring to FIGS. 1 and 2, description will be given of the problem for easy understanding of the gist of the problem.
[0006] First, description will be given of a configuration of a general travelling table apparatus of FIG. 1 and a measuring method of the apparatus.
[0007] The configuration of FIG. 1 includes a top table 1 which can travel in an x-axis direction and in a y-axis direction, an X bar mirror 5 for x-directional measurement, and a Y bar mirror 6 for y-directional measurement. A sample 30 is placed on the top table 1 . It is necessary to keep the sample 30 at the position when the top table 1 is moved. Therefore, the sample is adsorbed onto the top table 1 using vacuum or electrostatic force or is mechanically fixed thereon. First, the x-directional measurement will be described. Laser emitted from a laser head 10 is split by a beam splitter 9 . Resultant light proceeds via an interferometer 7 in a direction vertical to the X bar mirror 5 . Reflected light from the mirror 5 again passes through the interferometer 7 (the light again reflects on the mirror 5 in a double-path system). There is obtained interference light. The light is then received by a receiver 8 . The receiver 8 accordingly produces a signal indicating a position of the mirror 5 . Also in the y-axis direction, the distance between the interferometer 7 and the Y bar mirror 6 can be detected in a similar way. If the distance between the sample and each of the bar mirrors is kept unchanged, the sample position can be controlled with high precision according to variation in the distance of each bar mirror.
[0008] However, when the top table 1 is deformed as shown in FIG. 2, distance between a center of the sample 30 on the top table 1 and the mirror for x-directional measurement increases by ΔX relative to original distance X therebetween. An error of ΔX appears in a measured value of distance, and hence the sample positioning precision is lowered.
[0009] JP-A-1-274936 describes a prior art example of a travelling stage (X-Y stage). In the configuration of the travelling stage, springs are inserted respectively in a pressurized section and a fixing section of a guide rail so that the guide rail frees deformation of the table caused in association with the precision of the guide apparatus described above or by variation in temperature and a thermal expansion coefficient.
[0010] [0010]FIG. 11 shows the freeing structure of the guide rail in the prior art example in a schematic diagram.
[0011] In the configuration shown in FIG. 11, a coned disc spring 85 is disposed on a support pin 83 of a guide rail 82 on pressurized side, the guide rail being attached onto a travelling table 80 . Compressive force of the spring 85 brings the guide rail 82 into tight contact with the travelling table 80 . This allows a degree of freedom for the guide rail 82 with respect to variation in pressure beforehand applied on the pressurized side. Also in the pressurized section, a compression spring 87 is arranged for a pressure pin 89 to keep the pressure of the guide apparatus at a predetermined level. This also contributes to suppress deformation of the table 80 .
[0012] In the configuration of the prior art example, the spring 85 is used to bring the guide rail 82 into tight contact with the travelling table 80 . The guide rail 82 on the pressurized side has a degree of freedom also in other than the pressurized direction.
[0013] In other words, movement of the table 80 in a direction vertical to an upper surface of the table 80 depends on compressive force of the spring 85 . Therefore, when there appears acceleration due to shock or vibration in the vertical direction, the upper surface of the table 80 easily becomes unstable. To overcome this difficulty, if it is desired to increase rigidity of the table 80 in the vertical direction, the spring 85 must have a larger spring modulus. However, to guarantee the original purpose, namely, the smooth shift toward the pressurized direction, frictional force on the attaching surface must be minimized.
[0014] For this purpose, it can be considered a method to reduce roughness of the attaching surface, namely, to smooth the surface like a mirror surface. However, in consideration of the overall travelling table, since rigidity of the table in the travelling direction is as low as that in the pressurized direction, the structure becomes weak with respect to self-excited vibration and/or external disturbance.
SUMMARY OF THE INVENTION
[0015] It is therefore an object of the present invention to provide a travelling worktable apparatus in which deformation of the guide apparatus is reduced to a low level while keeping rigidity of the guide apparatus such that the distance between the mirror and a sample placed on the upper surface of the table can be kept fixed.
[0016] In accordance with the present invention, there is provided a travelling worktable apparatus, comprising a fixed base, an intermediate table mounted on said fixed base with a first guide disposed therebetween, said intermediate table being capable of achieving a reciprocating motion, a top table mounted on said intermediate table with a second guide disposed therebetween, said top table being capable of achieving a reciprocating motion in a direction which intersects a direction of the reciprocating motion of said intermediate table; and a measuring mirror disposed on said top table. The top table comprises a travelling table for holding said second guide, a sample table disposed on said travelling table for mounting a sample thereon, a pin for restricting said travelling table and said sample table, said pin being more easily deformed than said travelling table and said sample table; and an elastic body disposed between said travelling table and said sample table.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The objects and features of the present invention will become more apparent from the consideration of the following detailed description taken in conjunction with the accompanying drawings in which:
[0018] [0018]FIG. 1 is a plan view showing an overall configuration of a general travelling worktable apparatus;
[0019] [0019]FIG. 2 is a side view showing a variation of a table in the travelling worktable apparatus shown in FIG. 1;
[0020] [0020]FIG. 3A is a plan view showing an embodiment of a travelling worktable apparatus according to the present invention;
[0021] [0021]FIG. 3B is a side view showing an embodiment of a travelling worktable apparatus according to the present invention;
[0022] [0022]FIG. 4 is a magnified view of section A of FIG. 3A;
[0023] [0023]FIG. 5 is a side view to explain the embodiments shown in FIGS. 3A and 3B;
[0024] [0024]FIG. 6 is a perspective view to explain the embodiments shown in FIGS. 3A and 3B;
[0025] [0025]FIG. 7 is a perspective view of a parallel plate spring in another embodiment according to the present invention;
[0026] [0026]FIG. 8 is a side view to explain action of the plate spring shown in FIG. 7;
[0027] [0027]FIG. 9 is a side view of a sample table and a travelling table in another embodiment according to the present invention;
[0028] [0028]FIG. 10A is a plan view showing a sample table and a travelling table in another embodiment according to the present invention;
[0029] [0029]FIG. 10B is a cross-sectional diagram showing a sample table and a travelling table in another embodiment according to the present invention; and
[0030] [0030]FIG. 11 is a magnified cross-sectional diagram showing part of a sample table and part of a travelling table in a prior art example.
DETAILED DESCRIPTION
[0031] Referring now to the drawings, description will be given of an embodiment according to the present invention.
[0032] First, description will be given of embodiments shown in FIGS. 3A, 3B, 4 , and 5 .
[0033] [0033]FIGS. 3A, 3B, and 4 are a plan view of a travelling worktable apparatus, a side view thereof, and a magnified view of section A of FIG. 3A, respectively.
[0034] In FIGS. 3A and 3B, an X table (intermediate table) 2 is mounted on a fixed base 3 with a roller guide unit 11 disposed therebetween. A Y table (top table) 1 is mounted on a intermediate table 2 with a roller guide unit 12 disposed therebetween. The top table 1 is constituted with a Y 1 table (travelling table) 20 to support a guide apparatus and a Y 2 table (sample table) 21 to mount a sample and a mirror. Tables 20 and 21 are coupled with each other by a parallel plate spring 25 which easily deforms in the X-axis and Y-axis directions. In the mounting of the tables 2 and 1 , a pressure screw 15 pressurizes a pressurized-side guide rail 11 A 2 attached on the fixed-side table and a pressurized-side guide rail 12 A 2 . Details of the roller guide units will be described by referring to FIGS. 3A, 3B, and 4 . Since the roller guide units 11 and 12 are of the same mechanism, description will be given of only the pressure side of the roller guide 12 .
[0035] [0035]FIG. 4 is a magnified plan view of section A of FIG. 3A. The roller guide unit 12 includes two guide rails 12 B 1 and 12 B 2 disposed on a rear surface of the Y table 1 in the Y-axis direction, two guide rails 12 A 1 and 12 A 2 disposed corresponding to the guide rails 12 B 1 and 12 B 2 on the X table 2 in the Y-axis direction, a retainer 12 C with a roller 12 D arranged between the guide rails, and a pressure screw 15 to apply thrust to bring the roller 12 D into tight contact with its opposing guide rail.
[0036] The roller guide unit 12 is of a crossed roller type in which many rollers 12 D are arranged on the retainer 12 C in a cross layout, namely, the rollers 12 D alternately changes its direction by 90°. The rollers 12 D are held by the retainer 12 C in a movable state. That is, the rollers 12 D are brought into contact with grooves with a V-shaped cross section respectively disposed in opposing surfaces of the guide rails 12 A 2 and 12 B 2 and rolls thereon keeping the contact on the grooves.
[0037] Advantages of the embodiment will be described by referring to FIGS. 5 and 6.
[0038] When the guide rail 12 A 2 is pressurized, if a diameter of the roller 12 D 1 held between the guide rails 12 A 2 and 12 B 2 and between guide rails 12 A 1 and 12 B 1 (FIG. 4) is smaller than a diameter of the roller 12 D 2 which is going to enter a space between the guide rails for table transportation, force is upward applied in an inclined direction between the guide rails due to the direction of the roller 12 D 2 in FIGS. 5 and 6. The Y 1 table 20 is resultantly deformed. However, the deformation is absorbed by the spring 25 disposed between the Y 1 table 20 and the Y 2 table 21 , and hence the deformation of the Y 2 table 21 is reduced. Next, the roller 12 D 3 to enter the space between the guide rails (FIG. 4) is changed in direction by 90° relative to the roller 12 D 2 . Therefore, the Y 1 table 20 receives force downward in an inclined direction. However, the deformation of the sample table 21 is minimized as described above. In this connection, similar advantage can be expected for deformation of the tables caused by attaching errors of the guide rails and/or deformation of the tables due to variation in temperature.
[0039] By disposing an absorber 50 between the sample table 21 and the travelling table 20 , vibration of the Y 2 table 21 can be controlled. It is therefore possible to mitigate influence of reduction of rigidity due to an elastic body or element. There may be employed a mechanical absorber employing air, fluid, and the like as well as materials having vibration preventing effect such as synthetic resin, lubber, and the like.
[0040] When a degree of freedom exists between the Y 1 table 20 and the Y 2 table 21 , the position of the Y 2 table 21 relative to the Y 1 table 20 is easily changed. In the positioning of a sample, this elongates a period of time to determine a position of the Y 2 table 21 by acceleration or deceleration. To overcome the difficulty, a part of the Y 1 table 20 and a part of the Y 2 table 21 are restricted by a pin 40 having rigidity lower than that of the Y 1 table 20 and the Y 2 table 21 as shown in FIG. 6 to thereby remove translational motion of the Y 2 table 21 . Additionally, a parallel plate spring 25 including plate spring members 61 and 62 which can be easily deformed in one direction as shown in FIGS. 7 and 8 is attached with the deforming directions of the respective members 61 and 62 respectively matching the X-axis and Y-axis direction. This configuration prevents rotary motion of the Y 2 table 21 .
[0041] Description will now be given of another embodiment shown in FIGS. 7 and 8.
[0042] This embodiment is a parallel plate spring which can absorb deformation of the travelling table.
[0043] The parallel plate spring includes a Y 1 table attaching member 60 , a plate spring member 61 which can easily deform in the Y-direction of FIG. 7, a plate spring member 62 which is disposed on the member 61 and which can easily deform in the X-direction of FIG. 7, and a Y 2 table attaching member 63 . The spring members 61 and 62 easily deform in the directions which are substantially orthogonal to each other. Therefore, even when deformation containing X-directional and Y-directional components takes place in the travelling table, the deformation can be absorbed by the spring members 61 and 62 . FIG. 8 shows a state of the spring member 62 when the parallel plate spring is deformed. As can be seen from FIG. 8, the spring is changed in height by the deformation. Variation of the height can be obtained using an expression as follows.
ΔZ=L (1−cos θ); θ=sin −1 ( A/L )
[0044] where, ΔZ is displacement in a Z-axis direction of Y 2 attaching member, L is length of the plate spring member, and A is relative displacement between Y 1 table attaching member and Y 2 table attaching member.
[0045] Assume that the plate spring member has a height of 10 millimeters (mm) and the relative displacement between the Y 1 table attaching member and the Y 2 table attaching member is one micrometer (μm). Then, the displacement ΔZ in the Z-axis direction can be considerably minimized as
ΔZ=0.05 nanometer (nm).
[0046] Next, description will be given of another embodiment shown in FIG. 9.
[0047] In this embodiment, a parallel plate spring is not used as the elastic member or unit.
[0048] As shown in FIG. 9, in a configuration in which the Y 2 table 21 is linked with the Y 1 table 20 by a bolt 70 with a spacer 65 between the tables 21 and 20 , when an elastic modulus of the Y 2 table 21 is large than that of the bolt 70 , the bolt 70 serves as the elastic member. That is, deformation of the Y 2 table 21 can be absorbed by the bolt 70 . As such a combination, when the Y 2 table 1 is made of ceramics and the bolt 70 is made of-phosphor bronze, the advantage is enhanced. Advantageous absorption of the deformation can also be achieved by increasing the number of bolts and by reducing the diameter of the bolts.
[0049] Subsequently, another embodiment shown in FIGS. 10A and 10B will be described.
[0050] [0050]FIG. 10A is a plan view of the sample table and the travelling table and FIG. 10B is a cross-sectional view along line C-C of FIG. 10A.
[0051] This example is associated with a travelling worktable apparatus. In the apparatus, a travelling table includes a part which can be easily deformed, and deformation in linking part between the travelling table and the sample table is minimized.
[0052] In the configuration, the Y 1 table 20 is directly linked with the Y 2 table 21 by the bolt 70 . In this state, only a central area of the Y 1 table 20 is brought contact with a central area of the Y 2 table 21 . As shown in FIG. 10B, a groove is formed in the Y 1 table 20 . The Y 1 table 20 is therefore easily deformed in an area near the groove. The central part of the Y 1 table 20 in contact with the Y 2 table 21 is configured such that deformation of the guide retaining section is not easily propagated. When compared with the second embodiment not using the parallel plate spring, this embodiment is more effective to reduce deformation of the sample table. Additionally, the elastic member is formed integrally in the Y 2 table, the number of parts can be reduced and the size of the apparatus can be efficiently minimized.
[0053] In accordance with the present invention, the deformation of the tables is minimized while keeping rigidity of the guide apparatus. Therefore, the distance between the mirror and the sample on the upper surface of the table can be kept fixed.
[0054] While the present invention has been described in detail and pictorially in the accompanying drawings, it is not limited to such details since many changes and modifications recognizable to those of ordinary skill in the art may be made to the invention without departing from the spirit and scope thereof.
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In a travelling worktable apparatus including a roller guide unit to guide a travelling table. Deformation of a sample table caused in association with precision of the guide unit such as deviation in precision of rail attachment and precision of rollers is prevented while keeping rigidity of the roller guide. This keeps a fixed distance between a bar mirror unit and a sample on the sample table. For this purpose, the Y table (top table) of the prior art is subdivided into a travelling table to hold the roller guide and a sample table to mount a sample thereon. These tables are fixed by a pin which can be more easily deformed than the tables and are linked with each other by an elastic body.
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FIELD OF THE INVENTION
[0001] The present invention relates to an anisotropic conductive sheet, which is interposed between a circuit board such as a substrate and various circuit devices (components) to render conductive path, and to its manufacturing method.
RELATED ART
[0002] As recent electronic devices become smaller and thinner, there has been more and more increased necessity of connections between circuits of fine patterns and between a minute portion and a circuit of fine patterns and there has been employed a method of interposing an anisotropic conductive elastomer sheet between the electronic parts and the circuit board to render them conductive.
[0003] The anisotropic conductive elastomer sheet refers to an elastomer sheet that is conductive only in a specific direction. Generally, there are anisotropic conductive elastomer sheets, which are conductive in only the direction of thickness or would be conductive in only the direction of thickness if pressed in the direction of thickness. Owing to their features of achieving compact electrical connection without any other means such as soldering or mechanical fitting and enabling soft connection so as to absorb mechanical shock and distortion, the anisotropic conductive elastomer sheets have been extensively used in such fields as cell phones, electronic computers, electronic digital timepieces, electronic cameras, computers and the like. They are, further, extensively used as connectors for accomplishing electrical connection between a circuit device such as a printed circuit board and a lead-less chip carrier or a liquid crystal panel.
[0004] In the electric inspection of the circuit devices such as printed circuit boards and semiconductor integrated circuits, further, an anisotropic elastomer sheet is heretofore interposed between a region of electrodes of the circuit device to be inspected and a region of inspecting electrodes of the circuit board for inspection in order to achieve electrical connection between the electrodes to be inspected, which are formed on at least one surface of the circuit device to be inspected, and the inspecting electrodes formed on the surface of the inspecting circuit board.
[0005] It is known that an example of the above anisotropic conductive elastomer sheet may be obtained by cutting an anisotropic conductive block in a thin sheet such that the block that is formed integrally with thin metal wires disposed in parallel and insulating material enclosing the metal wires is cut in a direction orthogonal to the direction of the thin metal wires (JP-A-2000-340037).
[0006] In the anisotropic conductive film with thin metal wires, however, it is difficult to shorten distance between such thin metal wires and to secure anisotropic conductivity with a fine pitch as required by recent highly integrated circuit boards and electronic components. Further, it is likely that thin metal wires are to be buckled with compressive force or the like during the use thereof and easily pulled out after repetitive use so that the anisotropic conductive film may fail to keep its function to a sufficient degree.
[0007] In view of the above problems, therefore, this invention provides an anisotropic conductive sheet having a fine pitch as required by the recent highly integrated circuit boards and electronic parts preventing conductive members such as metal wires from slipping out.
DISCLOSURE OF THE INVENTION
[0008] The present invention has a feature in that an anisotropic conductive sheet includes electrically conductive thin layers that are scattering in the anisotropic conductive sheet in the direction of plane thereof and are penetrating through the anisotropic conductive sheet in the direction of thickness thereof.
[0009] More specifically, the present invention provides the following.
[0010] (1) An anisotropic conductive sheet expanding on a first plane, wherein when a first direction contained in said first plane is denoted as X-direction, a direction orthogonal X-direction and contained in said first plane is denoted as Y-direction and a direction orthogonal to X-direction and Y-direction is denoted as Z-direction, wherein said anisotropic conductive sheet has a predetermined thickness in Z-direction and a front surface and a back surface substantially in parallel with said first plane, the anisotropic conductive sheet comprising: a nonconductive matrix expanding on said first plane; and conductive thin layers scattered in said nonconductive matrix with two surfaces spaced apart across a predetermined thickness, at least one of the two surfaces being arranged in contact with said nonconductive matrix, wherein said conductive thin layers extend in Z-direction and penetrate throughout from the front surface to the back surface.
[0011] (2) An anisotropic conductive sheet expanding on a first plane, wherein when a first direction contained in said first plane is denoted as X-direction, a direction orthogonal to X-direction and contained in said first plane is denoted as Y-direction and a direction orthogonal to X-direction and Y-direction is denoted as Z-direction, wherein the anisotropic conductive sheet has a predetermined thickness in Z-direction and a front surface and a back surface substantially in parallel with said first plane being spaced apart across said predetermined thickness, the anisotropic conductive sheet comprising: strip-like members with conductive thin layers extending in X-direction, the strip-like members with the conductive thin layers being composed of nonconductive strip-like members having thickness in Z-direction and width in Y-direction and extending in X-direction; and the conductive thin layers being adhered to side surfaces of said nonconductive strip-like members substantially along Z-direction and having narrow width in X-direction along the side surfaces of said nonconductive strip-like members and extending from the front surface to the back surface of the anisotropic conductive sheet penetrating therethrough in Z-direction, wherein said strip-like members with the conductive thin layers being positioned and coupled to each side of each strip-like member so as to line up in Y-direction.
[0012] (3) The anisotropic conductive sheet according to (1) or (2), wherein said conductive thin layers are adhered to said nonconductive matrix or to said nonconductive strip-like members via an adhesive layer.
[0013] (4) The anisotropic conductive sheet according to any one from (1) to (3), wherein said conductive thin layers comprise at least a set of a flexible layer and a good conductive layer.
[0014] (5) The anisotropic conductive sheet according to any one from (1) to (4), wherein said nonconductive matrix or said nonconductive strip-like members comprise nonconductive elastomer.
[0015] (6) A method of manufacturing an anisotropic conductive sheet comprising: an adhering step of adhering conductive thin layers on the surface of a nonconductive sheet (A) being composed of nonconductive material to obtain a nonconductive sheet (A) with the conductive thin layers; an AB sheet stacking step of stacking nonconductive sheets (B) with the conductive thin layers obtained in the adhering step of adhering the layer to obtain an AB sheet laminate; and a cutting step of cutting the AB sheet laminate obtained in the AB sheet stacking step of obtaining the AB sheet laminate in a predetermined thickness.
[0016] In this invention, it is characterized in that an anisotropic conductive sheet which is conductive in the direction of thickness of the sheet, but is nonconductive in the direction contained in the plane thereof, comprises conductive thin layers penetrating the sheet in the direction of thickness, wherein the conductive thin layers are scattered as being insulated from each other. Penetrating throughout from the front surface to the back surface of the sheet stands for the penetration in the direction of thickness of the sheet, and may mean that the conductive thin layer (which may include a metal layer when metal is used) appears on both front and the back surfaces of the anisotropic conductive sheet. In the case of a metal layer, the metal layer as a whole may be made of a single kind of metal. Further, the front surface side may be electrically connected to the back surface side. Here, being insulated from each other may mean that the individual thin conductive layers are not electrically connected to each other. It can be so comprehended that the individual conductive thin layers are electrically independent (or insulated). Being scattered means that a plurality of electrically conductive thin layers are scattered separately from each other on X-Y plane which is a first plane of the anisotropic conductive sheet and are penetrating throughout the sheet in Z-direction. Further, it may be so considered that the conductive thin layers are arranged being separated away from each other in the matrix made of nonconductive members. Further, the individual conductive thin layers may exist in a state of being separated away from each other. Here, when the conductive thin layers are made of a metal, they may be called metal layers. In the case of the metal layers, the metal layers as a whole may include the case of being made of a single kind of metal.
[0017] In this invention, it is characterized in that an anisotropic conductive sheet which is conductive in the direction of thickness of the sheet, but is nonconductive in the direction contained in the plane thereof, comprises a plurality of strip-like nonconductive members with conductive thin layers disposed onto the members in a separate manner, wherein the plurality of strip-like nonconductive members are aligned to constitute the anisotropic conductive sheet and wherein the conductive thin layers penetrate the sheet in the direction of thickness. Being disposed in a separate manner may mean that the layers are not electrically connected in a continuous manner, or may mean that the layers are not physically connected in a continuous manner. The strip-like nonconductive member may stand for a nonconductive member of a slender shape. Being slender means that the ratio of the longitudinal length to the transverse length exceeds 1 and, more preferably, exceeds 10. That the plural members are aligned may mean a state or a structure in which the same or different kinds of strip-like nonconductive members with the conductive thin layer are consecutively arranged in Y-direction (transverse direction) of the nonconductive strip-like members. It may include a constitution in which these strip-like members are coupled together with a coupling agent to integrally form the sheet.
[0018] In the present invention, it may be further characterized in that the conductive thin layers are adhered to the strip-like nonconductive members via adhesive layers. Here, the adhesive layer is to adjust (which may include “absorb” and “relax”) differences in physical and/or chemical properties (e.g., elastic modulus, plastic deformation rate, thermal expansion rate, thermal conductivity, electronegativity, etc.) of the conductive thin layer (which may include a metal layer when metal is used) and of the nonconductive member (e.g., nonconductive strip-like member) such that the adhesive layer may improve the adhesion between the conductive thin layer and the nonconductive member. The adhesive layer may, for example, be a layer made of material having intermediate properties between the physical and/or chemical properties of the two, or may be a layer (including a layer of material having such physical and/or chemical properties as cause strong coupling) for strongly coupling the two. It also may be characterized in that the adhesive layer is made of metal oxide or metal. Examples of the metal oxide include indium oxide, tin oxide, titanium oxide or mixture thereof or compound thereof, and examples of the metal include chromium, e tc. For example, it may be characterized in that the adhesive layer comprises indium tin oxide (or indium oxide/tin oxide). The “indium tin oxide (or indium oxide/tin oxide)” is abbreviated as ITO and is ceramic material having a high degree of electric conductivity.
[0019] The conductive thin layer (which may include a metal layer when metal is used) may include at least a set of a layer (flexible layer) made of flexible metal and a layer (good conductive layer) made of metal having good electric conductivity. The flexible layer may have a function to modify the shape flexibly without being broken down by the distortion of the member to which the conductive thin layer (which may include a metal layer when metal is used) is adhered. In particular, it is considered that the flexible layer plays an important role during the handling when it is adhered to the substrate made of flexible material that can be bent, twisted, drawn or contracted. For example, the substrate made of material such as macromolecule material or elastomer is likely to undergo such deformation. Further, even the substrate made of rigid material tends to be deformed in a similar manner when its thickness is small. A good conductive layer is constituted of metal having high electric conductivity and may have a function to lower the resistance in the direction of thickness of the anisotropic conductive sheet. Further, since at least one set of layers are used, two or more sets of soft layers and good conductive layers may be included so as to be more capable of absorbing the distortion. However, an increase in the number of the layers makes the steps more complex. The good conductive layer may be sandwiched by the flexible layers at all times.
[0020] The layer made of flexible material may be a layer of metal which flexibly deforms itself to meet the external deformation, for example, the substrate deformation. The layer may not be cracked or broken so as not to develop electric breakdown. Further, the layer made of metal having good electric conductivity is the one made of metal having higher electric conductivity than the above flexible metal in an environment in which it is used. More preferably, the electric conductivity of metal having good conductivity is higher than that of the above flexible metal and is, more preferably, at least two times as high, and, yet more preferably, at least five times as high as that of the flexible metal. The above metal layers are combined together since it was found that the flexibility and good conductivity are not necessarily satisfied by a single kind of metal.
[0021] As flexible metal, there can be exemplified pure metal such as indium, tin or lead, or alloys such as indium and tin. According to “Rikagaku Jiten” (Iwanami Shoten Co.), indium is flexible yet having resistivity of 8.4×10 −6 Ωcm, tin has resistivity of 11.4×10 −6 Ωcm, and lead has resistivity of 20.8×10 −6 Ωcm. On the other hand, as the metal having good electric conductivity, there can be exemplified pure metal such as copper, silver, gold and alloys thereof. Similarly, according to “Rikagaku Jiten” (Iwanami Shoten Co.), copper has resistivity of 1.72×10 −6 Ωcm, silver has resistivity of 1.62×10 −6 Ωcm, and gold has resistivity of 2.2×10 −6 Ωcm. It will therefore be learned that flexible metal has resistivity at least twice as great as metal having good conductivity.
[0022] In the multiplicity of conductive thin layers (which may include a metal layer when metal is used), it is important that the layer of flexible metal and the layer of metal having good conductivity are electrically contacted to each other. Even when the layer made of good conductive metal is broken due to handling or the like so that the electricity is interrupted from flowing through the broken portion, it is expected that electricity flows into the layer of flexible metal being contacted so as to bypass the broken portion. As described above, the flexible metal has low electric conductivity. Once the broken portion is bypassed, therefore, electricity can be conducted to the other side of the layer made of good conductive metal across the bypassed broken portion. Owing to this structure, the layer made of flexible metal works as a redundant system for the passage of electricity. When there is a diffusion to some extent between the layers, adhesion is improved between the layers and, as a result, it is expected that the multi-layer function is improved. However, if the diffusion takes place too much to establish a completely mixed state, the multi-layer function decreases.
[0023] The anisotropic conductive sheet of the present invention is characterized in that it has conductivity in the direction of thickness of the sheet but has no conductivity in the direction of plane.
[0024] Here, being conductive may mean that the anisotropic conductive sheet having the above constitution has sufficiently high conductivity in the direction of thickness of the sheet. Usually, it is desired that the resistance among the terminals to which the connection is made by the anisotropic conductive sheet is, usually, not larger than 100 Ω (preferably, not larger than 10 Ω and, more preferably, not larger than 1 Ω). Being nonconductive may mean that the anisotropic conductive sheet exhibits no conductivity or exhibits insulating property, or exhibits a very low conductivity, or exhibits a very high electric resistance. At ordinary voltage (in a range of from several volts to several hundreds of volts), the anisotropic conductive sheet may exhibit a resistance of not smaller than 1 kΩ, and more preferably, not smaller than 1 MΩ.
[0025] In the anisotropic conductive sheet of the present invention, it may be also characterized in that the nonconductive matrix comprises a nonconductive elastomer, and the conductive members comprise a conductive elastomer.
[0026] The nonconductive elastomer is referred to elastomer without conductivity or having a very low conductivity and ordinary elastomer belongs to such elastomer. For example, as the nonconductive elastomer, butadiene copolymers such as natural rubber, polyisoprene rubber, butadiene/styrene, butadiene/acrylonitrile, butadiene/isobutylene, conjugated diene rubber and hydrogenated compounds thereof; block copolymer rubbers such as styrene/butadiene/diene block copolymer rubber, styrene/isoprene block copolymer, and hydrogenated compounds thereof; and chloroprene copolymer, vinyl chloride/vinyl acetate copolymer, urethane rubber, polyester rubber, epichlorohydrin rubber, ethylene/propylene copolymer rubber, ethylene/propylene/diene copolymer rubber, soft liquid epoxy rubber, silicone rubber and fluorine-contained rubber may be used. Among them, the silicone rubber is preferably used owing to its excellent heat resistance, cold resistance, chemical resistance, aging resistance, electric insulation and safety. The nonconductive elastomer usually has a high volume resistivity (e.g., not smaller than 1 MΩ-cm at 100 V) and is nonconductive.
[0027] In producing an anisotropic conductive sheet by arranging the strip-like members of the nonconductive elastomer, they may be chemically coupled together. In order to chemically bond them, a coupling agent may be applied among them. The coupling agent is the one for coupling these members, and may include an adhesive usually available in the market. For example, coupling a gents of the types of silane, aluminum and titanate may be used. Among them, a silane coupling agent is favorably used.
[0028] A method of manufacturing an anisotropic conductive sheet according to the present invention comprises the steps of: adhering conductive thin layers (which may include a metal layer when metal is used) on the surface of a nonconductive sheet made of nonconductive members to obtain a nonconductive sheet with the conductive thin layers (which may include a metal layer when metal is used); laminating a sheet member made of the nonconductive members with the conductive thin layers (which may include a metal layer when metal is used) to obtain a laminate; and cutting the laminate in a predetermined thickness.
[0029] Here, the nonconductive sheet may be a sheet member of a single kind or a collection of sheet members of different kinds. For example, the nonconductive sheet may be a collection of sheet members of the same material but having different thicknesses. In the step of adhering the conductive thin layers (which may include a metal layer when metal is used) onto the surface of the nonconductive sheet made of the nonconductive members, the conductive thin layers (which may include a metal layer when metal is used) may be adhered onto one surface or onto both surfaces of the sheet members. The conductive thin layers (which may include a metal layer when metal is used) can be adhered by any one of the vapor phase method, liquid phase method or solid phase method or by a combination thereof. Among them, the vapor phase method is particularly preferred. As the vapor phase method, it can be exemplified that PVD such as a sputtering method, a vacuum deposition method, and CVD. The conductive thin layers (which may include a metal layer when metal is used) may be adhered onto the nonconductive sheet via an adhesive layer. Further, the conductive thin layers (which may include a metal layer when metal is used) may be so constituted as to include at least a set of a flexible layer and a good conductive layer. In this case, the individual layers may be adhered by the same method or by different methods. The conductive thin layer with a narrow width is necessary to be adhered. Usually, the conductive thin layers are adhered by sputtering while applying a mask to the portions where the conductive thin layers are not to be adhered.
[0030] The nonconductive sheets with the conductive thin layers (which may include a metal layer when metal is used) are stacked. Stacking may mean that the nonconductive sheets with the conductive thin layers (which may include a metal layer when metal is used) are stacked in the direction of thickness of the sheet, which, however, does not exclude interposing a third sheet, a film or any other members among the nonconductive sheets with the conductive thin layers (which may include a metal layer when metal is used). In the step of stacking the sheet members, further, a coupling agent may be applied among the sheets so that the sheets are coupled together. The laminate prepared by stacking may be heated from the standpoint of increasing the coupling among the sheets, promoting the curing of the sheet members themselves or for any other purpose.
[0031] The laminate can be cut by using a blade such as a cemented carbide cutter or a ceramic cutter, by using a grindstone such as a fine cutter, by using a saw, or by using any other cutting device or cutting instrument (which may include a cutting device of the non-contact type, such as laser cutter). In the step of cutting, further, there may be used a cutting fluid such as a cutting oil to prevent overheating, to obtain finely cut surfaces or for any other purpose, or a dry cutting may be employed. Further, the object to be cut may be cut alone or by being rotated together with the cutting machine or instrument. It needs not be pointed out that a variety of conditions for cutting are suitably selected to meet the laminate. To cut in a predetermined thickness means to cut to obtain a sheet member having a predetermined thickness. The predetermined thickness needs not be uniform but may vary depending upon the places of the sheet member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 is a perspective view illustrating an anisotropic conductive sheet using conductive thin layers (which may include a metal layer when metal is used) according to an embodiment of the present invention.
[0033] FIG. 2 is a view illustrating the enlarged upper left portion of the anisotropic conductive sheet in FIG. 1 according to the embodiment of the present invention.
[0034] FIG. 3 is a perspective view illustrating a nonconductive sheet with the conductive thin layer (a metal layer may be included when metal is used) used in the embodiment of the present invention.
[0035] FIG. 4 is a view illustrating a step of laminating nonconductive sheets with the conductive thin layers (which may include a metal layer when metal is used as related to a method of manufacturing the anisotropic conductive sheet using the conductive thin layers (which may include a metal layer when metal is used) according to the embodiment of the present invention.
[0036] FIG. 5 is a view illustrating a step of cutting the laminate obtained in FIG. 4 as related to a method of manufacturing the anisotropic conductive sheet with the multiplicity conductive thin layers (which may include a metal layer when metal is used) according to the embodiment of the present invention.
[0037] FIG. 6 is a flowchart illustrating a method of preparing the anisotropic conductive sheet using the conductive thin layers (which may include a metal layer when metal is used) according to the embodiment of the present invention.
[0038] FIG. 7 is a view illustrating a portion of the nonconductive sheet with the multiplicity of conductive thin layers (which may include a metal layer when metal is used) used for the anisotropic conductive sheet that uses the multiplicity of conductive thin layers (which may include a metal layer when metal is used) according to another embodiment of the present invention.
[0039] FIG. 8 is a view illustrating a portion of the nonconductive sheet with the multiplicity of conductive thin layers (which may include a metal layer when metal is used) used for the anisotropic conductive sheet that uses the multiplicity of conductive thin layers (which may include a metal layer when metal is used) according to a further embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0040] The present invention will now be described in further detail by way of embodiments with reference to the drawings. However, the embodiments are simply to illustrate concrete materials and numerical values as preferred examples of the present invention, but are not to limit the present invention.
[0041] FIG. 1 illustrates an anisotropic conductive sheet 10 according to an embodiment of the present invention using conductive thin layers (which may include a metal layer when a metal is used) as the conductive thin layers of the present invention. A Cartesian coordinate system XYZ of the anisotropic conductive sheet 10 is illustrated at a left upper part. The anisotropic conductive sheet 10 of this embodiment is a rectangular sheet member but may be a sheet member of a shape other than the rectangular shape. The anisotropic conductive sheet 10 is constituted by arranging a strip-like member 12 which is nonconductive member at an upper end followed by strip-like members 14 which are nonconductive members with the conductive thin layers (which may include a metal layer when a metal is used) which are arranged in the lateral direction (direction of width). The strip-like member 12 made of the nonconductive member and the strip-like member 14 made of the nonconductive member with the conductive thin layers (which may include a metal layer when a metal is used), and the neighboring strip-like members 14 made of the nonconductive members with the conductive thin layers (which may include a metal layer when a metal is used), are coupled together by using a coupling agent. These members made of the nonconductive material may form a nonconductive matrix, and the conductive thin layers made of the conductive material may be regarded as scattering conductive thin layers. In the anisotropic conductive sheet 10 of this embodiment, the nonconductive elastomer is a silicone rubber manufactured by Mitsubishi Jushi Co. or a silicone rubber manufactured by Shin-etsu Polymer Co., and the coupling agent is a silane coupling agent manufactured by Shin-etsu Polymer Co. Further, a multiplicity of conductive thin layers (which may include a metal layer when a metal is used) that will be described later are used as the conductive thin layers (which may include a metal layer when a metal is used).
[0042] FIG. 2 is a view illustrating on an enlarged scale the left upper corner portion of FIG. 1 , i.e., illustrates the two kinds of strip-like members 12 and 14 in further detail. The strip-like member 20 corresponds to the strip-like member 12 made of the nonconductive member of FIG. 1 , and the strip-like member 40 corresponds to the strip-like member 14 made of the nonconductive member with the conductive thin layers (which may include a metal layer when a metal is used) 30 of FIG. 1 . In FIG. 1 , the extreme left upper conductive thin layer (which may include a metal layer when a metal is used) 30 is adhered, as shown in FIG. 2 , to the strip-like member 40 made of the nonconductive member via an adhesive layer 50 . The strip-like members 20 and 40 are coupled together with a coupling agent. Here, the strip-like members are protruded by the amount of the conductive thin layer (which may include a metal layer when a metal is used). Therefore, gaps 31 and 33 which occur due to no-matching develop on both sides of the conductive thin layer (which may include a metal layer when a metal is used). Here, however, no gaps develop if the conductive thin layer (which may include a metal layer when a metal is used) is very thin. These gaps may simply remain as the gaps or may be filled with a coupling agent or with any other filler. Usually, if the gaps remain empty, acute crack ends 311 develop into cracks. As a result, the strip-like members 20 and 40 that are coupled together may often be separated. From this point of view, therefore, it is desired to fill the gaps. A coupling agent, an adhesive agent or any other coupling material may be applied on the upper surface of the conductive thin layer (which may include a metal layer when a metal is used)(on the side that comes in contact with the nonconductive strip-like member) so as to be joined to the strip-like member 20 made of the nonconductive member, or may not be joined thereto. What is concerned to the above conductive thin layer (which may include a metal layer when a metal is used) also applies to other conductive thin layers (which may include a metal layer when a metal is used) (e.g., metal layer 36 may be included). In this case, the strip-like member 40 corresponds to the strip-like member 20 made of the nonconductive member. This also holds for the gaps 37 and 39 .
[0043] The thickness of these strip-like members remains substantially the same (T) in this embodiment and, hence, the sheet has the thickness T. As described above, the neighboring strip-like members 12 and 14 are coupled together with the coupling agent and constitute a piece of sheet as shown in FIG. 1 . Here, the coupling agent is nonconductive, and the sheet is nonconductive in the direction of the plane thereof. In this embodiment, the conductive thin layers (which may include a metal layer when a metal is used) are arranged on one side. In other embodiments, however, the conductive thin layers (which may include a metal layer when a metal is used) may be arranged on both sides.
[0044] The strip-like members 20 , 40 , 60 , - - - have widths t 11 , t 12 , - - -. In this embodiment, these widths are all the same. In other embodiments, however, these widths may all be the same or different. The width can be easily adjusted in producing the anisotropic conductive sheet of the embodiment that will be described later. The conductive thin layer (which may include a metal layer when a metal is used) 30 is formed starting from a distance t 21 from the left of the strip-like member 40 and has a length t 22 . A gap is t 23 up to the right neighboring conductive thin layer (which may include a metal layer when a metal is used) 34 . The lengths and gaps of these conductive thin layers (which may include a metal layer when a metal is used) remain constant, respectively, in this embodiment, but, in other embodiments, may all be the same or different. The lengths and gaps can be easily adjusted in producing the anisotropic conductive sheet 10 of the embodiment that will be described later.
[0045] In this embodiment, the conductive thin layer (which may include a metal layer when a metal is used) 30 has a length of approximately 50 μm, a gap to the right neighboring conductive thin layer (which may include a metal layer when a metal is used) 34 is approximately 30 μm, and the nonconductive strip-like members 40 , 60 , - - - to which the conductive thin layers (which may include a metal layer when a metal is used) 30 , 36 are adhered have a width of approximately 50 μm. In other embodiments, however, the gaps and widths may be longer (or larger) or shorter (or smaller) than those mentioned above.
[0046] In general, it is desired that the conductive thin layers (which may include a metal layer when a metal is used) are thinner than the width (e.g., t 12 ) of the strip-like members 40 , 60 , - - -, and, more preferably, smaller than 1/10 thereof and, particularly preferably, smaller than 1/50 thereof. When the strip-like members 40 , 60 , - - - have a width of as long as 0.1 mm or more, it is desired that the thickness of the conductive thin layers (which may include a metal layer when a metal is used) has a thickness of not larger than 10 μm.
[0047] Though there is no particular limitation on the thickness, width or length, when used for connecting the circuit board and the terminals of electronic parts, it is desired that the anisotropic conductive sheet of this embodiment has a size that matches with these sizes. In this case, the sizes are, usually, 0.5 to 3.0 cm×0.5 to 3.0 cm and 0.5 to 2.0 mm in thickness.
[0048] A method of manufacturing the anisotropic conductive sheet of the above embodiment will now be described with reference to FIGS. 3 to 5 . FIG. 3 illustrates a sheet 16 made of nonconductive members with conductive thin layers. The thickness t 12 corresponds to the width t 12 of the strip-like member 40 of FIG. 1 . FIG. 4 illustrates stacking the nonconductive strip-like members 20 having conductive thin layers (which may include a metal layer when a metal is used) 30 adhered thereon. The conductive thin layers (which may include a metal layer when a metal is used) 30 can be adhered by various methods. In this embodiment, however, they are adhered by sputtering. That is, by using the nonconductive sheet 20 as a substrate, a target is so adjusted as to meet the component of the thin conductive layers (which may include a metal layer when a metal is used) 30 , and the conductive thin layers (which may include a metal layer when a metal is used) 30 are adhered by using a sputtering apparatus. The width of the conductive thin layer (which may include a metal layer when a metal is used) and the gap can be adjusted by the masking that meets therewith. The nonconductive sheet of this embodiment is a nonconductive elastomer, and a contrivance should be so made that the temperature of the substrate is not elevated too much. It is recommended to use, for example, a magnetron sputtering or an ion beam sputtering.
[0049] FIG. 4 illustrates a state of forming a laminate by stacking the nonconductive sheets 20 to which the conductive thin layers (which may include a metal layer when a metal is used) 30 are adhered. The nonconductive sheets 20 to which the conductive thin layers (which may include a metal layer when a metal is used) 30 are adhered are so stacked that the directions of the conductive thin layers (which may include a metal layer when a metal is used) are all in alignment (in parallel). On the laminate 90 being stacked, there are further stacked the nonconductive sheets 20 . A coupling agent is applied among these sheets so that the sheets are coupled together. It may be so taken that the thickness of these sheets corresponds to t 11 or t 12 in FIGS. 1 and 2 . That is, the widths of the strip-like members of FIGS. 1 and 2 can be freely varied by varying the thickness of these sheets. Usually, as fine pitches, these widths are not larger than approximately 80 μm and are, more, preferably, not larger than approximately 50 μm. In this embodiment, the thickness is so adjusted that the strip-like members possess a width of approximately 50 μm. Stacking the strip-like members with the conductive thin layers (which may include a metal layer when a metal is used) may include stacking one or more pieces of nonconductive sheets between the strip-like members with the conductive thin layers (which may include a metal layer when a metal is used).
[0050] FIG. 5 illustrates a step of cutting the laminate 92 obtained through the above step. The laminate 92 is so cut that the thickness of the obtained anisotropic conductive sheet 100 has a desired thickness T. This thickness T corresponds to T in FIGS. 1 and 2 . Thus, it is allowed to easily form a thin anisotropic conductive sheet or a thick anisotropic conductive sheet which are usually difficult to produce. Usually, the thickness is approximately 1 mm. The thickness, however, can be decreased down to be smaller than approximately 100 μm (or smaller than approximately 50 μm when particularly desired) or can be selected to be about several millimeters. In this embodiment, the thickness is approximately 1 mm.
[0051] FIG. 6 is a flowchart illustrating a method of manufacturing the above anisotropic conductive sheet. First, the conductive thin layers (which may include a metal layer when a metal is used) 30 are adhered on the nonconductive sheet 20 (S- 01 ). In this embodiment, the conductive thin layers (which may include a metal layer when a metal is used) are formed by sputtering on one surface only of the conductive sheet. At this moment, gaps among the conductive thin layers (which may include a metal layer when a metal is used) are masked by using a tape or the like (S- 01 - 1 ) so that the conductive thin layer (which may include a metal layer when a metal is used) does not adhere thereon. After the conductive thin layers (which may include a metal layer when a metal is used) are adhered (S- 01 - 2 ), the masking is removed by such a method as removing the masking tape (S- 01 - 3 ). The nonconductive sheet 20 with the conductive thin layers (which may include a metal layer when a metal is used) 30 is stocked for use in the next step (S- 02 ). Next, the nonconductive sheet with the conductive thin layers (which may include a metal layer when a metal is used) is placed at a predetermined position for stacking (S- 03 ). Optionally, the coupling agent is applied onto the nonconductive sheet (S- 04 ). This step may be omitted, as a matter of course, since it is optional (the same holds hereinafter). The nonconductive sheet 20 with the conductive thin layers (which may include metal layers when a metal is used) 30 is placed thereon (S- 05 ). Check if the thickness (or height) of the stacked laminate is reaching a desired thickness (or height)(S- 06 ). If the desired (predetermined) thickness has been reached, the routine proceeds to the step of cutting (S- 10 ). If t he desired (predetermined) thickness has not been reached, the coupling agent is optionally applied onto the conductive sheet (S- 07 ). The nonconductive sheet with the conductive thin layers (which may include metal layers when a metal is used) is placed thereon (S- 08 ). Check if the thickness (or height) of the stacked laminate is reaching a desired thickness (or height)(S- 09 ). If the desired (predetermined) thickness has been reached, the routine proceeds to the step of cutting (S- 10 ). If the desired (predetermined) thickness has not been reached, the routine returns back to step S- 04 where the coupling agent is optionally applied onto the conductive sheet. At the step of cutting, the anisotropic sheet is cut out piece by piece or in a plurality of number of pieces at one time (S- 10 ).
[0052] FIG. 7 illustrates an isotropic conductive sheet according to another embodiment of the present invention, i.e., schematically illustrates a nonconductive sheet member with conductive thin layers (multiplicity of metal layers when a metal is used) obtained by adhering a multiplicity of conductive thin layers (multiplicity of metal layers when a metal is used) 30 to the nonconductive sheet member 20 , which is used as a nonconductive sheet with conductive thin layers (which may include metal layers when a metal is used). Since the multiplicity of conductive thin layers (multiplicity of metal layers when a metal is used) are adhered while masking both sides of the multiplicity of conductive thin layers (multiplicity of metal layers when a metal is used) 30 , the side surfaces 15 are rising like walls. The multiplicity of layers include, successively from the lower side, an adhesive layer 50 of an indium tin oxide, a flexible layer 52 of indium, a good conductive layer 54 of copper, a flexible layer 56 of indium, a good conductive layer 58 of copper, a flexible layer 60 of indium, a good conductive layer 62 of copper, a flexible layer 64 of indium, a good conductive layer 66 of copper and a flexible layer 68 of indium. The multiplicity of layers are considered to exhibit an increased resistance against the distortion from the external side. In this embodiment, the layers have such thicknesses that the adhesive layers are each approximately 500 angstroms thick, the flexible layers are each approximately 5000 angstroms thick and the good conductive layers are each approximately 5000 angstroms thick. Namely, the conductive thin layers (which may include metal layers when a metal is used) without the adhesive layer have a thickness of approximately 45000 angstroms (approximately 4.5 μm). In this embodiment, nothing has been placed on the flexible layer 68 . To increase the adhesion, however, it is desired to adhere an adhesive layer. The base member 20 is made of a nonconductive elastomer having a thickness of approximately 50 to 70 μm. Such an elastomer has been manufactured by, for example, Shin-etsu Polymer Co. In this embodiment, the nonconductive elastomer is a silicone rubber manufactured by Mitsubishi Jushi Co. or a silicone rubber manufactured by Shin-etsu Polymer Co.
[0053] These thicknesses are suitably selected depending upon the conditions of use. Preferably, the adhesive layer has a thickness of approximately 50 angstroms to approximately 2000 angstroms and, more preferably, approximately 100 angstroms to approximately 1000 angstroms. The flexible layer has a thickness of approximately 500 angstroms to approximately 20000 angstroms and, more preferably, approximately 1000 angstroms to approximately 10000 angstroms. The good conductive layer has a thickness of approximately 500 angstroms to approximately 20000 angstroms and, more preferably, approximately 1000 angstroms to approximately 10000 angstroms.
[0054] The conductive thin layer (which may include a metal layer when a metal is used) 30 of this embodiment has the adhesive layer provided on the surface only of the base member 24 . It is, however, also allowable to provide an adhesive layer (of the same material or different material) on the uppermost flexible layer 68 . The adhesive layer may harmonize the physical and/or chemical properties of another layer contacting to the conductive thin layer (which may include a metal layer when a metal is used) or may improve the adhesion.
[0055] The flexible layers 52 , 56 , 60 , 64 and 68 of this embodiment are all made of the same material. In other embodiments, however, they may be all made of different materials or may partly be made of the same material. The layers 52 , 56 , 60 , 64 and 68 of flexible metals of this embodiment are made of indium.
[0056] The good conductive layers 54 , 58 , 62 and 66 of this embodiment are made of the same material. In other embodiments, however, they may be made of different materials or may partly be made of different materials. The layers 54 , 58 , 62 and 66 of good conductive metals of this embodiment are made of copper.
[0057] FIG. 8 schematically illustrates a further embodiment of the present invention. What is different from the embodiment of FIG. 7 is that in adhering a conductive thin layer (which may include a metal layer when a metal is used), the side surfaces 15 standing like walls are avoided but, instead, tilted side surfaces 17 are formed by shortening the width (or length) of the layers little by little when the layers are viewed upward from the substrate 20 . In this embodiment, the mask is varied stepwise to adjust the widths of the layers. It is, however, also allowable to form the conductive thin layer (which may include a metal layer when a metal is used) and cut it aslant. In this embodiment, it is considered that gaps 31 , 33 , 37 , 39 shown in FIG. 2 occur little, and the strip-like members are firmly bonded together.
[0058] The multiplicity of layers of this embodiment include, successively from the lower side, an adhesive layer 50 of an indium tin oxide, a flexible layer 52 of indium, a good conductive layer 54 of copper, a flexible layer 56 of indium, a good conductive layer 58 of copper, a flexible layer 60 of indium, a good conductive layer 62 of copper, a flexible layer 64 of indium, a good conductive layer 66 of copper and a flexible layer 68 of indium. The multiplicity of layers are considered to exhibit an increased resistance against the distortion from the external side. In this embodiment, the layers have such thicknesses that the adhesive layers are each approximately 500 angstroms thick, the flexible layers are each approximately 5000 angstroms thick and the good conductive layers are each approximately 5000 angstroms thick (in other embodiments, an indium-tin alloy is used in the same structure). Namely, the conductive thin layer (which may include a metal layer when a metal is used) without the adhesive layer has a thickness of approximately 45000 angstroms (approximately 4.5 μm). In this embodiment, nothing has been placed on the flexible layer 68 . To increase the adhesion, however, it is desired to adhere an adhesive layer. The base member 20 is made of a nonconductive elastomer having a thickness of approximately 50 to 70 μm. Such an elastomer has been manufactured by, for example, Shin-etsu Polymer Co. In this embodiment, the nonconductive elastomer is a silicone rubber manufactured by Mitsubishi Jushi Co. or a silicone rubber manufactured by Shin-etsu Polymer Co.
[0059] As described above, the anisotropic conductive sheet of the present invention has the effect of not only maintaining insulation in the direction of the plane while exhibiting satisfactory conductivity in the direction of thickness but also enabling the sizes such a strengths of the nonconductive members and conductive thin layers to be freely set to easily accomplish fine pitches desired for achieving a high degree of integration. Further, since the conductive thin layers are directly adhered on the nonconductive members, the metal wires do not slip out which tend to occur when the linear metals are used as the conductive portions. Besides, the conductive thin layers are necessarily surrounded by the nonconductive members avoiding contact caused by the approach/contact of conductive particles in the direction of plane of the sheet, which is likely to occur in the anisotropic conductive sheet in which conductive particles such as of a metal are mixed. When the multiplicity of conductive thin layers (multiplicity of metal layers when a metal is used) a reused, it is considered that good conductivity is not lost even when the good conductive layers are cracked.
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An anisotropic conductive sheet interposed between a circuit board such as a substrate and various circuit parts to render them conductive and its manufacturing method. The anisotropic conductive sheet has a fine pitch required by the recent highly integrated circuit boards and electronic parts, and exhibits conductivity in only the direction of thickness of the sheet due to the use of conductive thin layers such as of a metal which does not slip out. The anisotropic conductive sheet ( 10 ) includes conductive thin layers ( 30 ) that are scattering in the direction of plane of the anisotropic conductive sheet ( 10 ) and are penetrating through in the direction of thickness of the anisotropic conductive sheet ( 10 ).
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[0001] This application clams the benefit of U.S. Provision Patent Application Ser. No. 60/992,901 filed on 6 Dec. 2007, which is hereby incorporated by reference in its entirety.
BACKGROUND
[0002] For some types of inkjet printer ink cartridges ink is introduced into the cartridge through one or more fill holes molded into the cartridge housing. Ink fill holes are often positioned at the top of the cartridge so that the holes may also function as vent holes for venting the ink holding chamber(s) within the housing. In one such ink cartridge, a “vent plug” is inserted into each fill hole after the cartridge is filled with ink. The vent plug substantially closes the fill hole, leaving just a small opening or gap for venting the ink chamber. Ink fill holes are typically quite small, about 1/10 inch in diameter in some cartridges, and the vent openings are significantly smaller. Accordingly, the vent plugs are also very small. Fabricating and installing the tiny vent plugs adds significantly to the cost of the ink cartridge. Also, problems are sometimes encountered fabricating and installing vent plugs due to the small size of the plugs. For example, particulate debris and deformed plugs can jam or otherwise disable the automated machinery used to make and install the plugs, causing costly downtime and repairs.
DRAWINGS
[0003] FIG. 1 is a perspective view illustrating an ink cartridge having ink fill holes, according to one embodiment of the disclosure.
[0004] FIG. 2 is an elevation section view of an ink fill hole from the cartridge of FIG. 1 , according to one embodiment of the disclosure.
[0005] FIG. 3 is a plan section view of the ink fill hole shown in FIG. 2 , taken along the line 3 - 3 in FIG. 2 .
[0006] FIG. 4 is a detail section view of a portion of the ink fill hole shown in FIG. 2 .
[0007] FIG. 5 is an elevation section view of the ink fill hole shown in FIG. 2 with an ink fill needle inserted into the hole breaking away the membrane at the bottom of the hole.
[0008] FIG. 6 is an elevation section view of the ink fill hole shown in FIG. 5 after the ink fill needle has been withdrawn from the hole.
[0009] FIG. 7 is an elevation section view of the ink fill hole shown in FIG. 2 with an ink fill needle inserted into the hole puncturing the membrane at the bottom of the hole.
[0010] FIG. 8 is an elevation section view of the ink fill hole shown in FIG. 7 after the ink fill needle has been withdrawn from the hole.
[0011] FIG. 9 is an elevation section view of an ink fill hole from the cartridge of FIG. 1 , according to a second embodiment of the disclosure.
[0012] FIG. 10 is a plan section view of the ink fill hole shown in FIG. 9 taken along the line 10 - 10 in FIG. 9 .
[0013] FIG. 11 is an elevation section view of the ink fill hole shown in FIG. 9 with an ink fill needle inserted into the hole puncturing the membrane at the bottom of the hole.
[0014] FIG. 12 is an elevation section view of the ink fill hole shown in FIG. 11 after the ink fill needle has been withdrawn from the hole.
DETAILED DESCRIPTION
[0015] Embodiments of the disclosure were developed in an effort to provide an alternative to the use of vent plugs to close ink fill holes in an ink cartridge. Embodiments will be described with reference to an ink fill hole in a tri-color ink cartridge. Embodiments of the disclosure, however, are not limited to use with tri-color ink cartridges or to ink fill holes, but might also be used in other ink cartridges, other fluid cartridges or to close other openings in a cartridge. The example embodiments shown in the Figures and described below, therefore, illustrate but do not limit the scope of the disclosure.
[0016] As used in this document: “membrane” means a thin sheet or layer covering an opening or separating two adjoining areas; and “plastic” means a moldable polymer.
[0017] FIG. 1 is a perspective view illustrating a tri-color ink cartridge 10 that includes a housing 12 enclosing three ink holding chambers. An ink fill hole 14 , 16 , 18 extends through the top of housing 12 to a corresponding ink holding chamber. Only one ink holding chamber 20 is visible in FIG. 1 , corresponding to fill hole 14 . Housing 12 may be formed as a single part or as two or more discrete parts affixed to one another. Although an ink cartridge housing such as housing 12 is typically formed by molding plastic into the desired configuration, other techniques or materials might also be used to form housing 12 . Ink is held in foam 22 or another suitable porous material in chamber 20 . Ink cartridge 10 also includes a printhead (not visible in FIG. 1 ) located at the bottom of cartridge 10 below the ink holding chambers. The printhead includes an array of ink ejection nozzles through which drops of ink are ejected at the urging of thermal or piezoelectric “firing” elements in the printhead. A flexible circuit 24 carries electrical traces from external contact pads 26 to the firing elements.
[0018] Ink cartridge 10 is just one example of a cartridge in which embodiments of the new hole closure may be implemented. Other examples include “free ink” cartridges in which there is no ink-holding material in some or all of the ink holding chambers and ink cartridges that are solely ink reservoirs (i.e., cartridges that do not include a printhead).
[0019] FIG. 2 is an elevation section view illustrating one example embodiment of an ink fill hole 14 in the cartridge of FIG. 1 . FIG. 3 is a plan section view of fill hole 14 taken along the line 3 - 3 in FIG. 2 . Referring to FIGS. 2 and 3 , hole 14 is defined by a sidewall 28 that extends from a top end 30 at an exterior of housing 12 to a bottom end 32 at ink chamber 20 (ink chamber 20 is not shown in FIGS. 2-3 ). The bottom of hole 14 is closed by a membrane 34 spanning hole 14 . In the embodiment shown, membrane 34 is integral to housing 12 and fully closes hole 14 until an ink fill needle is inserted into hole 14 and through membrane 34 , as described below, or until membrane 34 is otherwise breached. Referring now also to the detail view of FIG. 4 , a first extent of the periphery 36 of membrane 34 is thinned at the junction with sidewall 28 to form a locally weaker part 38 . The thickness of membrane 34 remains fully intact along a second extent of periphery 36 to form a locally stronger part 40 .
[0020] Thus, membrane 34 is configured to break away from sidewall 28 along weaker part 38 when an ink fill needle 42 is inserted into hole 14 , as shown in FIG. 5 , and to rebound back toward the original, closed position at the urging of stronger part 40 when ink fill needle 42 is withdrawn from hole 14 , as shown in FIG. 6 . Stronger part 40 forms a living hinge on which membrane 34 swings open upon the insertion of fill needle 42 and swings back upon the withdrawal of fill needle 42 . The mechanical characteristics of polyethylene terephthalate or other such plastics typically used for molding ink cartridges, along with the size and shape of stronger part 40 permit partially re-closing hole 14 upon withdrawal of fill needle 42 . It is desirable that hole 14 remain open enough to allow air to pass in and out of chamber 20 through hole 14 but not so open as to allow excessive evaporative losses from chamber 20 . Depending on the characteristics of fill needle 42 (e.g., size, shape/sharpness, and insertion force) the configuration of membrane 34 might also allow fill needle 42 to puncture membrane 34 upon insertion into hole 14 , as shown in FIG. 7 . In the case of needle puncture, the entire periphery 36 of membrane 34 acts as a living hinge to return membrane 34 toward the original, closed position when ink fill needle 42 is withdrawn from hole 14 , as shown in FIG. 8 .
[0021] Referring again to FIGS. 2-4 , in one example configuration in which ink fill hole 14 is about 0.23 inches long and 0.11 inches in diameter, typical for an ink cartridge 10 in FIG. 1 , membrane 34 has a nominal thickness in the range of 0.005 inches to 0.015 inches. An ink fill needle used in an automated ink fill process typically exerts enough pressure to puncture a layer of molded polyethylene terephthalate up to about 0.040 inches thick. Thus, a plastic membrane 34 in the range noted above should be easily punctured in an automated ink fill process. Also, where it is desirable to weaken a membrane 34 to allow the membrane to break away upon insertion of the ink fill needle, membrane 34 may be beveled or otherwise thinned at weaker part 38 to a thickness in the range of 0.002 inches to 0.005 inches along about 270 degrees of its periphery 36 , leaving stronger part 40 along about 90 degrees of periphery 36 . In the example configuration shown in FIGS. 2-4 , therefore, weaker part 38 is likely to fail significantly sooner than stronger part 40 and before membrane 34 is punctured but membrane 34 is also sufficiently thin to allow membrane puncture without damaging the fill needle or other fill tooling in the event the beveled weaker part 38 does not fail upon needle insertion. Also, in this example configuration, for an ink fill needle about 0.05 inches in diameter (about ½ the diameter of hole 14 ) membrane 34 will rebound to close at least 80% of a cross sectional area of hole 14
[0022] In the embodiment shown in FIGS. 9-12 , membrane 34 is configured for needle puncture only. Referring first to FIGS. 9 and 10 , membrane 34 has a uniform thickness along its entire periphery 36 . Thus, membrane 34 is configured so that fill needle 42 punctures membrane 34 when an ink fill needle 42 is inserted into hole 14 , as shown in FIG. 11 , and the entire periphery 36 of membrane 34 acts as a living hinge to return membrane 34 toward the original, closed position when ink fill needle 42 is withdrawn from hole 14 , as shown in FIG. 12 .
[0023] Although it is expected that membrane 34 will usually be molded as an integral part of cartridge housing 12 , it may be possible to form membrane 34 using other fabrication techniques. For example, membrane 34 might be formed with a secondary molding operation or by welding or staking a thin plastic sheet over hole 14 . It may be desirable in some ink cartridges to form membrane 34 at the top end 30 of hole 14 , or at some intermediate location between the top end 30 and the bottom end 32 of hole 14 . Also, while it is expected that membrane 34 will usually fully close hole 14 until breached, for some ink cartridges membrane 34 may substantially but not fully close hole 14 due to, for example, perforating the periphery of membrane 34 . Perforations may be desirable in any event to reduce or otherwise control the force needed to breach membrane 34 . Thus, the claims recite a membrane that “substantially closes” or a membrane “substantially closing” the hole to cover those cartridges in which a membrane in the “unbreached” or “formed” state may not always fully close the hole.
[0024] The article “a” as used in the following claims means one or more. Thus, for example, “a weaker part” means one or more weaker parts and, accordingly, a subsequent reference to “the weaker part” refers the one or more weaker parts.
[0025] The present disclosure has been shown and described with reference to the foregoing example embodiments. It is to be understood, however, that other forms, details and embodiments may be made without departing from the spirit and scope of the disclosure which is defined in the following claims.
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In one embodiment, a cartridge includes: a housing having a chamber therein for holding a fluid; a hole extending through the housing to the chamber; and a breachable membrane that, in an unbreached state, substantially closes the hole, the membrane resiliently configured such that, upon being breached, the membrane rebounds to a breached state only partially closing the hole.
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This application claims the benefit of U.S. Provisional Application, Ser. No. 60/116,610, filed Jan. 21, 1999 entitled GeAs SULPHIDE GLASSES CONTAINING P, by Bruce G. Aitken.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 5,389,584 (Aitken et al.) describes stable glasses that exhibit excellent transmission far into the infrared region of the spectrum. These glasses consist essentially of, expressed in terms of mole % on the sulphide basis, 55-95% GeS 2 , 2-40% As 2 S 3 , 0.01-20% Ga 2 S 3 , and/or In 2 S 3 and 0-10% MS x wherein M is at least one modifying cation selected from the group consisting of Li, Na, K, Ag, Tl, Ca, Sr, Ba, Cd, Hg, Sn, Pb, Al, Sb, Y and rare earth metals of the lanthanide group, 0-20% Cl and/or F, 0-5% Se, and wherein the S and/or Se content can vary between 85 and 125% of the stoichiometric value.
When glasses having compositions within these ranges were doped with praseodymium ions (Pr 3+ ), it was found that the glasses exhibited strong 1 G 4 fluorescence at 1.3 μm with a lifetime (τ) value of at least 300 μsec. However, this was only achieved if an effective amount of gallium and/or indium were present in the glass composition. These components served to disperse the Pr 3+ dopant, thereby avoiding the deleterious effect of concentration quenching. Otherwise, in a binary, arsenic germanium sulphide glass doped with Pr 3+ ions, the latter dopant was completely clustered and, therefore, the glass exhibited very weak fluorescence at 1.3 μm.
Such co-doped glasses have been shown to be particularly useful in the production of optical devices used in telecommunication. These devices include amplifiers, upconverters and lasers. The use is based on the fact that a rare earth dopant, such as the Pr 3+ ion, is well dispersed in a glass containing gallium and/or indium ions as co-dopants. As a consequence, fluorescence emanating from the rare earth metal dopant is not degraded by concentration quenching, or by similar, non-radiative, quenching processes.
The invention of the—584 patent was directed at improving the thermal stability of known, gallium sulphide glasses. Thermal stability is evidenced by the difference between the temperature at the onset of crystallization in a glass and the glass transition temperature (T x −T g ). At the same time, the desirable transmission characteristics, and other properties, of the gallium sulphide glasses were maintained.
The invention, on which the patent was based, derived from two fundamental discoveries. First, it was found that increased concentrations of arsenic in gallium, germanium sulphide glasses imparted enhanced thermal stability to the glasses. Second, it was found that the presence of gallium (Ga) and/or indium (In) in the glass eliminated rare earth clustering, thereby assuring, in the case of Pr doping, that the fluorescence at 1300 nm was not quenched.
The present invention is based on the discovery of a co-dopant, other than Ga and/or In, that is equally as effective in dispersing a rare earth metal dopant. At the same time, other important advantages are effected.
It is a basic purpose, then, of the present invention, to provide such alternative co-dopant for the rare earth metal doped glasses of the—584 patent, while retaining the properties of those glasses.
It is a further purpose to provide an improved, co-doped glass for optical devices used in telecommunications.
It is a still further purpose to provide a co-dopant that will result in at least some increase in the phonon energy level that can be generated in the glass.
It is another purpose to provide a means of dispersing a rare earth metal dopant in a glass, thereby enhancing the effectiveness of the glass.
SUMMARY OF THE INVENTION
In part, the invention resides in a GeAs sulphide glass having composition ranges consisting essentially of, as calculated in mole % on a sulphide basis: 55-95% GeS 2 , 0-40% As 2 S 3 and/or Sb 2 S 3 , 0.01-25% P 2 S 5 , 0-15% MS x where M is one or more of the group consisting of Li, Na, K, Ag, Tl, Ca, Sr, Ba, Cd, Hg, Sn, Pb, B, Al, Si, Y, and a rare earth metal of the lanthanide series, 0-20% Cl and/or F, 0-5% Se and 0-5% O, the total S+Se content being between 75 and 130% of the stoichiometric value.
The invention further resides in an optical component composed of a GeAs sulphide glass having composition ranges consisting essentially of, as calculated in mole % on a sulphide basis: 55-95% GeS 2 , 0-40% As 2 S 3 and/or Sb 2 S 3 , 0.01-25% P 2 S 5 , 0-15% MS x where M is one or more of the group consisting of Li, Na, K, Ag, Tl, Ca, Sr, Ba, Cd, Hg, Sn, Pb, B, Al, Si, Y, and a rare earth metal of the lanthanide series, 0-20% Cl and/or F, 0-5% Se and 0-5% O, the total S+Se content being between 75 and 130% of the stoichiometric value.
The invention also contemplates a method of dispersing a rare earth metal ion in a GeAs sulphide base glass as a dopant, the method comprising including a source of phosphorus in the glass as a co-dopant.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 in the accompanying drawing are graphical representations, each illustrating a method of showing the manner in which clustering of a rare earth metal, dopant ion is decreased in accordance with the present invention.
FIG. 3 is a graphical representation illustrating an amplifying process involving a Pr 3+ ion.
DESCRIPTION OF THE INVENTION
The basic, GeAs sulphide, glass family of the present invention is essentially the same as that of the earlier—584 patent. There are small differences in the effective ranges of certain components, such as As 2 S 3 and/or Sb 2 S 3 . However, these do not appreciably alter the transmission and the thermal stability characteristics described in the patent. Therefore, the teachings of the patent are incorporated herein in their entirety.
The essential distinction is based on discovery that phosphorus can be effectively employed as a co-dopant in the GeAs sulphide glasses. When substituted for Ga and/or In, phosphorus has essentially the same effect as these elements, insofar as dispersing a rare earth metal, dopant ion in the glass. This avoids the quenching effect that degrades fluorescence from the dopant, and that is the result of clustering of the rare earth metal ions in the glass.
The use of phosphorus as a co-dopant provides additional advantages as well. Gallium and indium have a tendency to redden the glass, that is, to red-shift the absorption edge of the glass. This shift of the absorption edge to longer wavelengths in the red portion of the spectrum tends to reduce light transmission. When such a glass, doped with Pr 3+ ions, is to be used to generate fluorescence at 1.3 μm, a significant amount of the requisite 1.0 μm pump power may be dissipated by host glass absorption, thereby degrading fluorescence efficiency.
In contrast, phosphorus produces a more yellow color, that is, a blue-shift of the absorption edge of the glass. This shift to shorter wavelengths in the blue portion of the spectrum tends to broaden the transparency window of the glass, thereby alleviating the problem.
The presence of phosphorus in the glass, an element relatively lighter in weight than the major glass constituents (Ge, As and S), results in an increase in the maximum phonon energy of the glass. When such a glass is doped with a rare earth metal, this characteristic can improve the efficiency of fluorescing transitions, particular those of 4-level systems where the lower laser level is an excited state. An increased maximum phonon energy can result in a more rapid depopulation of the spent ions to the ground state via nonradiative decay. In the case of a Pr-doped glass, for example, the more rapid depopulation occurs from the intermediate 3 H 5 level of the Pr 3+ ion to the 3 H 4 ground state.
The same effect can be achieved by including other compatible, network-forming elements into the glass composition that are lighter in weight than Ge, As and S. Such lighter weight elements include B, Al, Si and O. Aluminum is effective to the extent that it can be incorporated in the present glass compositions. However, aluminum is incorporated in the present glasses only with difficulty, thus limiting its utility. In general, in addition to P, Si and O are of greatest interest.
The light weight elements have the desirable effect of increasing the rate of ion depopulation at certain levels, for example, the indicated 3 H 5 level of the Pr 3+ ion. At the same time, they may depopulate other fluorescent levels at a faster rate than desired. Accordingly, this situation may necessitate limiting the total content of the light weight elements other than P to not more than about 1% of the glass composition.
In the case of Pr doping, we have found that the lifetime of the technologically important 1300 nm fluorescence decreases rapidly from about 300 μs to about 100 μs as the P concentration rises to 1% or higher. This reduction in fluorescence lifetime corresponds to a drop in the quantum efficiency of the 1300 nm luminescence from about 60% to about 20%. This pronounced decrease in fluorescence lifetime and quantum efficiency is attributed to the fact that incorporation of P in these glasses gives rise to an increase in the maximum phonon energy (MPE), thereby resulting in an increased probability of nonradiative decay.
Specifically, for the case of P, the MPE is about 700 cm−1. This corresponds to a glass vibrational frequency that is associated with the stretching of a P═S double bond. It has been found that the MPE of P-containing glasses can be reduced to an intermediate value through the simultaneous incorporation of either Ga or In in the glass. These codopants react with P═S double bonds to form —Ga—S—P—S— or —In—S—P—S— units which vibrate at lower frequency. Ga and/or In, in a ratio of less than 1:1 with P, have some effect. However, where the ratio is less than 1:1, a degree of P═S double bonds remain, thereby markedly diminishing fluorescence. In contrast, where the ratio of Ga and/or In to P is at least 1:1, and preferably greater, the 1300 nm fluorescence lifetime is only reduced to about 200 μs. This corresponds to a useful quantum efficiency of about 40%, thus creating a decided preference for a Ga and/or In ratio to P of at least 1:1 or greater.
Since the gallium and indium elements are similar in weight to germanium, they have essentially no effect on phonon energy. Hence, they have essentially no effect on ion decay or depopulation at either the desired 3 H 5 level or at other undesirable levels. Thus, an optimum level of P can be employed and supplemented with Ga or In where additional declustering is required. The optimum ratio of P to Pr is usually about 5:1.
Phosphorus tends to decrease chemical durability of a glass. Also, as will be seen later, only a relatively limited amount may be effective for dispersal purposes. Therefore, while up to 25% of the sulphide may be incorporated in the present glasses, its use may be limited by these factors.
The invention is further described with reference to FIGS. 1 and 2 in the accompanying drawings.
FIG. 1 in the accompanying drawing is a graphical representation showing the essential equivalence of P, In, or Ga as a dispersant to prevent clustering of rare earth metal ions in a GeAs sulfide glass. The plotted data were taken from a glass having the formula Ge 25 (As 10−x M x )S 65 wherein M x represents the amount of co-dopant in the glass. In the FIGURE, the ratios of co-dopant to gadolinium (Gd), as a dopant, are plotted on the horizontal axis. Line widths of electron paramagnetic resonance (EPR) in gauss, a measure of clustering, are plotted on the vertical axis.
Studies carried out with co-doped glasses have shown that electron paramagnetic resonance (EPR) provides a useful technique to ascertain whether a rare earth metal, ion dopant in a host glass is clustered or dispersed. It has been shown that the line width of the EPR resonance directly correlates with the degrees of clustering of the dopant ion, with broader EPR resonances indicating increased levels of clustering. In the FIGURE, the dopant ion is gadolinium (Gd).
Curves shown in FIG. 1 are based on plotted, EPR data measured on the GeAs sulphide glass doped with a fixed amount (500 ppm by weight) of Gd and varying amounts of the individual Ga, In and P co-dopants. Curve A is based on data with Ga as a co-dopant; Curve B with In as the co-dopant; Curve C with P as the co-dopant in accordance with the present invention. It will be noted that In and P are essentially equally effective in preventing clustering. Gallium is somewhat more effective at lower ratios, but the difference becomes less significant at higher ratios.
The plotted data indicate that the EPR line width of glasses co-doped with P drops steadily as the P concentration increases. As indicated earlier, this demonstrates that the rare earth metal dopant becomes increasingly dispersed as the P concentration increases.
Unfortunately, the EPR technique of measurement is not effective with all rare earth metal, dopant ions. For most other ions, such as Pr 3+ , it is necessary to employ a measurement of fluorescent intensity. However, as will appear subsequently, the two methods of measurement correlate very well.
FIG. 2 is a graphical representation illustrating the prevention of clustering of rare earth metal ions as measured by fluorescent intensity. In FIG. 2, the ratio of co-dopant to dopant is plotted on the horizontal axis. The 1 D 2 intensity, a measure of fluorescent intensity arising from the 1 D 2 level of the Pr +3 ion, is plotted on the vertical axis. In this measure, an increase in intensity signifies a decrease in clustering.
In FIG. 2, Curve D is the intensity curve for the base glass of FIG. 1 co-doped with Ga. Curve E is the intensity curve for the glass co-doped with phosphorus. The intensity curves move in the reverse of the EPR linewidth curves. Otherwise, they correspond closely in behavior.
In FIG. 1, the linewidth curves decrease rapidly to a co-dopant/dopant ratio of about 20:1, and then tend to flatten out. Likewise, in FIG. 2, the intensity curves increase rapidly to a co-dopant/dopant of about 20:1, and then level off. The similarity tends to confirm the validity of both forms of measurement.
It is apparent from the plotted data in FIGS. 1 and 2 that a ratio of co-dopant to dopant as low as 1:1 has a measurable effect that indicates a decrease in clustering. The effect becomes quite significant at a ratio of 5:1, and little practical benefit with regard to clustering is seen at ratios beyond about 20:1.
The invention is further described with reference to specific embodiments. It will be appreciated that these embodiments are intended only to be illustrative, not limiting.
TABLE I sets forth batch compositions in parts by weight for several glasses in accordance with the present invention. Batches 1-5 contain Gd 2 S 3 as a rare earth metal dopant. Batches 6-14 contain praseodymium as a rare earth metal dopant.
TABLE II sets forth, in atomic %, glass compositions corresponding to the batches shown in TABLE I. Also shown are the ratio of phosphorus to rare earth metal ion dopant (P/Gd, Pr). Also shown are glass appearance; the EPR linewidth measured in gauss on glasses 1-5; the 1 D 2 fluorescence intensity measured on glasses 6-10, the 1 G 4 fluorescence lifetime measured in microseconds on glasses 6-12.
TABLE I
component
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Ge
3.904
3.905
3.909
3.939
3.977
3.909
3.904
3.905
3.939
3.977
3.954
3.966
3.918
3.923
As
1.603
1.596
1.582
1.464
1.314
1.582
1.604
1.596
1.464
1.314
—
—
1.213
1.215
S
4.481
4.485
4.487
4.521
4.515
4.491
4.485
4.487
4.525
4.569
4.612
4.764
4.535
4.592
Gd 2 S 3
0.009
0.009
0.009
0.009
0.009
—
—
—
—
—
0.005
0.005
0.005
0.005
Pr
—
—
—
—
—
0.005
0.005
0.005
0.005
0.005
0.067
0.203
0.033
0.084
P
0.003
0.007
0.013
0.017
0.136
0.013
0.003
0.007
0.067
0.136
1.367
1.067
0.301
0.188
TABLE I
component
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Ge
3.904
3.905
3.909
3.939
3.977
3.909
3.904
3.905
3.939
3.977
3.954
3.966
3.918
3.923
As
1.603
1.596
1.582
1.464
1.314
1.582
1.604
1.596
1.464
1.314
—
—
1.213
1.215
S
4.481
4.485
4.487
4.521
4.515
4.491
4.485
4.487
4.525
4.569
4.612
4.764
4.535
4.592
Gd 2 S 3
0.009
0.009
0.009
0.009
0.009
—
—
—
—
—
0.005
0.005
0.005
0.005
Pr
—
—
—
—
—
0.005
0.005
0.005
0.005
0.005
0.067
0.203
0.033
0.084
P
0.003
0.007
0.013
0.017
0.136
0.013
0.003
0.007
0.067
0.136
1.367
1.067
0.301
0.188
Glass batches shown in TABLE I were typically prepared by mixing the respective elements in an evacuated, fused-silica container. While batches based on the elements are preferred, metal sulphide, selenide or halide can be employed. For example, Gd was added as Gd 2 S 3 in batches 1-5.
The batch constituents were compounded and sealed into silica ampoules which had been evacuated to about 10 −5 to 10 −6 Torr. The ampoules were sealed, and then placed into a furnace designed to impart a rocking motion to the batch during melting. After melting the batch for about 1 to 2 days at 850°-950° C., the melts were quenched by inserting the hot ampoules in room temperature water. The homogeneous glass rods, thus formed, had diameters of about 7-10 mm and length of about 60-70 mm. These rods were annealed at about 325°-425° C.
For production purposes, the glass batches can be melted in larger melting units. It is necessary, however, to employ at least a partially evacuated, closed container as a melting vessel. This avoids volatilization, as well as air contact and consequent oxidizing of the batch materials.
The batch will produce a substantial vapor pressure during melting. The closed melting unit must be sufficiently evacuated to accommodate such vapor pressure without fracture. After an adequate time to achieve a homogeneous melt, the molten glass is cooled while still enclosed. This provides a solid body that may be reshaped as desired.
It is apparent that phosphorus is effective as a co-dopant in GeAs sulphide glasses to counter the tendency for rare earth metal ions to cluster and become ineffective. Thus, the glasses of the present invention, co-doped with phosphorus, find application in fabrication of the telecommunication equipment, such as amplifiers operating at 1.3 μm.
As noted earlier, the relatively light weight of the phosphorus provides a further advantage when used in such equipment. The lighter weight has the potential for alleviating a bottleneck that may occur in the optical transitions relevant to amplification at 1.3 μm.
In a glass doped with Pr −3+ ions, such amplification process involves pumping the Pr −3+ ions from the 3 H 4 ground level to the 1 G 4 lasing level where fluorescence at 1.3 μm occurs as desired for amplification. Such fluorescence results in decay to the 3 H 5 level. Non-radiative decay to the ground level then depopulates the 3 H 5 level, but may not occur rapidly enough.
Due to the low phonon energy of GeAs sulphide glasses, non-radiative decay from the intermediate 3 H 5 level to the ground state may not occur at a rate sufficient to depopulate the 3 H 5 level as rapidly as is desired. The greater phonon energy supplied by the lighter weight phosphorus tends to enhance the rate of decay, and thus the rate of depopulation of ions.
FIG. 3 is a graphical representation of the amplifying process described above. FIG. 3 depicts significant energy levels in pumping and decay of the Pr 3+ ion in the process of amplifying 1.3 μm radiation.
The several horizontal lines in FIG. 3 represent significant energy levels of the Pr 3+ ion for present purposes. Initially, ions are pumped from the 3 H 4 ground level to the 1 G 4 lasing level as indicated by the vertical arrow between these levels. From the 1 G 4 level, the ions emit 1.3 μm amplifying radiation and fall to the 3 H 5 level, as indicated by the downwardly pointed, vertical arrow.
Due to the low phonon energy of the GeAs sulfide glass, there is little tendency for excited ions to decay nonradiatively to the intermediate 3 F 4 level (as indicated by the wavy line between the latter and the 1 G 4 level). This is an undesirable process that quenches 1.3 μm fluorescence, for example, in Pr-doped oxide glasses. However, there is a tendency for the ions to accumulate at the 3 H 5 level before undergoing final decay to the 3 H 4 ground level. This final non-radiative decay is indicated by a wavy line between the 3 H 5 and 3 H 4 levels.
The tendency to accumulate at the 3 H 5 level is undesirable because, due to energy mismatch, a subsequent pumping action at 1.0 μm cannot raise the accumulated ions back to the 1 G 4 level and, thus, 1.3 μm fluorescence from these ions is quenched.
The invention has been illustratively described with reference to praseodymium and gadolinium as rare earth metal dopants. It will be appreciated, however, that it is applicable to other rare earth metal dopants as well. This includes those in a group between and including lanthanum and lutetium in the Periodic Table. The content of a dopant ion will generally range from 0.005-1.0 wt. %.
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A GeAs sulphide glass family of transparent glasses having transmission far into the infrared portion of the spectrum, containing a source of phosphorus ion as a co-dopant to effect dispersion of a rare earth metal ion dopant in the glass, an optical component comprising the glass, and a method of dispersing a rare earth metal ion in the glass.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is divisional application of Ser. No. 10/609,252 filed Jun. 27, 2003 which is a continuation-in-part of U.S. application Ser. No. 10/342,452 filed Jan. 14, 2003.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] —
BACKGROUND OF THE INVENTION
[0003] The present invention relates to clothes washing machines and the like, and specifically, to a lid locking mechanism that may optionally include a magnetic lid sensor.
[0004] The spin cycle of a washing machine removes water centrifugally from wet clothes by spinning the clothes at high speed in a spin basket. In order to reduce the possibility of injury to the user during the spin cycle, it is known to use an electronically actuated lock for holding the washing machine lid in the closed position. U.S. Pat. Nos. 6,363,755; 5,823,017; and 5,520,424, assigned to the present assignee and hereby incorporated by reference, describe several locking mechanisms. Desirably, the locking mechanism minimizes projecting parts on the washing machine lid which might snag clothing or reduce access to the spin basket, and is simply integrated into the washing machine housing.
[0005] A signal indicating the state of the washing machine lid as opened or closed may be used to “wake” circuitry from a power saving mode, or to coordinate operation of the lid lock by ensuring the lid is closed before the lock in engaged. Such a signal may be provided by a switch communicating with the washing machine lid. Ideally such a switch could not be easily defeated, would operate reliably when used with other washing machine components with normal manufacturing tolerances, and would be resistant to contamination by water and dirt.
BRIEF SUMMARY OF THE INVENTION
[0006] The present invention provides a magnetic lid sensor for a washing machine lid supporting a magnet where the sensor includes a sensor housing mountable on the washing machine and a magnet sensor element held within the sensor housing displaced from a point of rest of the magnet when the washing machine lid is closed. At least one ferromagnetic flux director is held by the sensor housing having a first end near the point of rest of the magnet and having a second end near the magnet sensor to conduct flux there between.
[0007] Thus it is one object of the invention to provide a practical magnetic lid sensor for a washing machine. Magnetic flux directors allow the magnet sensor to be positioned in a protected position within the housing and still receive sufficient variation in magnetic flux to switch reliably and predictably with lid opening.
[0008] The magnet sensor may be a reed switch, the sensor housing may be non-magnetic and two ferromagnetic flux directors may be used to conduct the magnet flux in a loop between the magnet sensor and the magnet.
[0009] Thus it is another object of the invention to conduct sufficient magnetic flux to reliably activate a low cost magnet sensor.
[0010] The invention also provides a lid lock assembly which includes a cap sized to cover a mounting hole in the housing of a washing machine near a point of rest of the washing machine lid when the washing machine lid is closed. The cap may include at least one downwardly extending threaded hole. A housing of the lid lock may be located below the hole in the housing of the washing machine and may have a hole receiving an upwardly extending screw. The screw engages the downwardly extending threaded hole of the cap to hold the washing machine housing between an upper surface of the lock housing and a lower surface of the cap. The mounting hole is near the pivot point of a hook that may be used to lock the lid in the closed position.
[0011] Thus it is another object of the invention to provide a simple mounting system for a lid lock. Thus, it is another object of the invention to provide a simple mechanism for supporting a movable bolt that is robust against the force of a person attempting to open the lid.
[0012] The cap may include only a single downwardly extending threaded hole and the lock housing may include only a single mounting hole for attaching the lock housing to the washing machine.
[0013] It is thus another object of the invention to provide a lid lock that may be attached to the housing with a single screw. The positioning of the pivot of the hook to minimize torsion on the housing and to transfer forces on the lid to additional compression of the lock housing against the washing machine increases the robustness of this single screw mounting.
[0014] The downwardly extending hole in the cap may be blind to present a continuous upper cap surface.
[0015] Thus it is another object of the invention to minimize any holes that might accumulate or conduct water and dirt.
[0016] The cap may be an elastomeric plastic molded over a non-elastomeric plastic forming the threaded hole.
[0017] It is another object of the invention to provide both cushioning bumper and support for the lock housing in one structure. It is another object of the invention to provide a bumper that passes magnetic flux and that covers a hole in the washing machine housing sufficient in size to freely pass magnetic flux.
[0018] The present invention also provides generally a lid lock for a washing machine using a hook pivoting about an axis so as to move between a first locked position in which the opening of the closed lid is prevented by interference between the hook and an engagement surface on the lid and a second position in which the closed lid is free to open. An actuator may move the hook between the first position and the second position. A contact interface between the hook and the engagement surface is selected to prevent the force of opening the closed lid from moving the hook to the second position.
[0019] Thus it is another object of the invention to provide a locking mechanism with low friction that remains stably in the locked position without the application of a locking force.
[0020] The actuator may operate to alternatively move the hook toward and away from the locked position and may, for example, be a bi-directional solenoid.
[0021] Thus, it is another object of the invention to provide a lock that may be quickly locked and unlocked through electrical signals and yet does not require continuous consumption of electrical power or manual setting or resetting.
[0022] The engagement surface may move along a tangent line with first movement of the closed lid to open and the pivot axis of the hook may lie along a tangent line opposite the direction of movement of the engagement surface.
[0023] Thus it is another object of the invention to provide that opening force on the lid result in an upward force to the locking mechanism such as is absorbed against the housing of the washing machine.
[0024] The engagement surface in the lid may be an aperture and the hook may engage the aperture.
[0025] Thus it is another object of the invention to provide an extremely simple lid locking mechanism that does not require projections that might snag clothing or interfere with access to the spin basket.
[0026] The hook may include a central tooth engaging the aperture and flanking shoulders resting against sides of the aperture when the tooth is so engaged.
[0027] Thus it is another object of the invention to provide a simple structure for limiting the depth of engagement of the hook with the lid when the lid is in place.
[0028] The lock mechanism may include a spring communicating with the hook for urging the hook toward the first position when the hook is proximate to the first position and urging the hook toward the second position when the hook is proximate to the second position. A contact set may communicate with the hook to provide a switch output indicating when the hook is at the first position as distinguished from when the hook is at the second position.
[0029] Thus it is another object of the invention to create a bi-stable positioning of the hook such as simplifies determination of the hook state using a contact set and which prevents inadvertent movement of the hook under vibration and the like.
[0030] The contact set may provide a closed circuit between a first and second terminal when the hook is in the first position in an open circuit between the first and second terminals when the hook is in the second position.
[0031] It is thus another object of the invention to provide certainty in any signal indicating the lid is locked in the presence of possible wiring failure.
[0032] The contact set may include a sliding contact moving laterally over a stationary contact and the stationary contact may be positioned next to a cam surface engaging the sliding contact with over travel of the sliding contact to lift the sliding contact transversely away from the stationary contact.
[0033] Thus it is another object of the invention to provide a contact set capable of detecting small motions while using large area contacts.
[0034] These particular objects and advantages may apply to only some embodiments falling within the claims and thus do not define the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1 is a perspective view of a top loading washing machine suitable for use with the present invention showing a strike formed from a side of an opened lid of the washing machine and a bolt for engaging the same when the lid is closed;
[0036] FIG. 2 is a fragmentary cutaway of the portion of the lid and washing machine near the bolt of FIG. 1 showing support of a locking mechanism beneath a lid well;
[0037] FIG. 3 is a simplified top plan view of the bolt of FIG. 2 extending through a wall of the lid well to engage a strike of the lid and illustrating a retraction position, engagement position, and extension position of the bolt and further showing corresponding states of an electrical switch connected to the bolt to provide an indication of bolt position;
[0038] FIG. 4 is a top plan view of the locking mechanism of FIG. 2 in partial cutaway to show a rotating shaft connecting the bolt of FIG. 3 to a contact assembly and a bi-directional actuator;
[0039] FIG. 5 is a perspective view of the contact assembly of FIG. 4 such as implements the switch of FIG. 3 and showing an overcenter spring that causes the bolt to be bi-stable in the extension and retraction position when the lid is open, and the engagement and retraction position when the lid is closed;
[0040] FIG. 6 is a perspective, exploded, fragmentary view of a portion of the housing of FIGS. 2 and 4 showing mounting of the locking mechanism to the washing machine;
[0041] FIG. 7 is a cross-sectional view taken along line 7 - 7 of FIG. 6 showing flux directors for conducting magnetic flux from a magnet mounted in the lid of the washing machine into the washing machine housing to a magnet sensor;
[0042] FIG. 8 is a cross-sectional view taken along line 8 - 8 of FIG. 7 showing the interface between the hook and lid and the location of the pivot point of the hook such as prevents movement of the hook by forces generated by attempted opening of the lid; and
[0043] FIGS. 9 through 11 are side elevational views of one contact of the switch of FIG. 5 showing the use of a cam surface for lifting the contact upon overtravel.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0044] Referring now to FIG. 1 , a top loading washing machine 10 suitable for use with the present invention includes a lid 12 opening upward about a horizontal lid hinge axis 14 . The lid hinge axis 14 is positioned near the top rear edge of the washing machine 10 so that a front edge 16 of the lid 12 may raise and lower to expose and cover an opening 20 through which clothing may be inserted into the spin basket. A front-loading washing machine (not shown) is also suitable for use with the present invention as will be apparent to those of ordinary skill in the art.
[0045] Referring now to FIG. 2 , when the lid 12 is in the closed position, it sits within a lid well 18 having vertical walls 32 surrounding vertical walls 22 of the lid 12 and having a horizontal ledge 19 on which the lower surface of the lid 12 may rest. A vertical wall 22 of the lid 12 near a front edge 16 of the lid 12 provides a strike plate 24 having a bolt hole 26 .
[0046] Referring also to FIG. 3 , the bolt hole 26 is sized to receive a tooth portion 28 of a lateral extension 40 of a hook 30 passing horizontally through a vertical wall 32 of the lid well 18 opposite the strike plate 24 when the lid 12 is closed. When the tooth portion 28 is engaged in the bolt hole 26 , the lid 12 may not be raised vertically as indicated by arrow 36 as a result of the lower edge of the bolt hole 26 interfering with a lower edge of the tooth portion 28 .
[0047] The tooth portion 28 extends from shoulders 34 which flank the tooth portion 28 and are sized to be larger than the bolt hole 26 so that the shoulders 34 may not pass through the bolt hole 26 . When the lid 12 is closed, the shoulders 34 limit the amount that the hook 30 may extend through the bolt hole 26 and thus limit the length of extension of the hook 30 from the vertical wall 32 of the lid well 18 . When the lid 12 is open, however, the shoulders 34 may move further in extension as will be described.
[0048] Referring also to FIG. 4 , the lateral extension 40 of the hook 30 is connected to a radial portion 42 to form a hook pivoting, as indicated by arrow 45 , about a rotation axis 44 where the hook is attached to an axle 46 . The axle 46 is supported for rotation within a housing 48 of a locking mechanism positioned beneath the lid well 18 .
[0049] Referring now to FIG. 3 , as will be discussed in detail below, the hook 30 communicates via the axle 46 (shown schematically in FIG. 3 ) with a contact set 52 . The contact set 52 provides a three position switch in which two poles 54 a and 54 b connecting to respective terminals 56 a and 56 b in a center position (B) and disconnect from terminals 56 b in left and right positions (C) and (A), respectively. Where the poles 54 a and 54 b are joined to each other so that in position (B), a closed circuit is presented across terminals 56 a and 56 b and in positions (A) and (C), an open circuit is presented across terminals 56 a and 56 b.
[0050] These three switch positions (A), (B), and (C) correspond to three positions (A′), (B′), and (C′) of the hook 30 . The first hook position (A′) is where the forward tooth portion 28 of the hook 30 remains retracted behind the vertical wall 32 of the lid well 18 . The hook 30 may be in this position prior to the hook 30 being actuated or if the hook has been actuated, but was obstructed or jammed, or if the actuator fails. In this position, an open circuit is presented across terminals 56 a and 56 b.
[0051] The second hook position (B′) is where tooth portion 28 of the hook 30 extends through the bolt hole 26 and the shoulders 34 of the hook abut strike plate 24 . The hook 30 will be in this position if the lid 12 is closed and the hook 30 is actuated. In this position, the lid 12 is locked and a closed circuit is presented across terminals 56 a and 56 b.
[0052] The third hook position (C′) is where tooth portion 28 and the shoulders 34 of the hook 30 extends past the position normally occupied by the strike plate 24 as may occur if the lid 12 is open at the time of actuation of the hook 30 . In this position, an open circuit is presented across terminals 56 a and 56 b.
[0053] Thus, it will be understood that a proper locking of the lid by the hook 30 is indicated by a closed circuit across terminals 56 a and 56 b , whereas an open circuit across these terminals 56 a and 56 b , indicates either an obstruction of the hook 30 at the aperture in the vertical wall 32 or failure of the actuator or over-extension indicating that the lid 12 was not closed at the time of locking or an electrical break in the wiring communicating with the terminals 56 a and 56 b . Any of these latter open circuit conditions suggest that access may be had to the opening 20 leading to the spin basket of the washing machine and may be used to override the spin cycle, stopping it or preventing it from starting.
[0054] Referring now to FIGS. 4 and 5 , motion of the hook 30 along the lateral axis 60 causes rotation of the axle 46 within the housing 48 . The axle 46 includes two downward extending forks 62 a and 62 b that engage tabs 64 on a carriage 66 . In this way, rotation of the axle 46 with motion of the hook 30 along the lateral axis causes motion of the carriage 66 on a carriage track 65 along lateral axis 68 parallel to lateral axis 60 .
[0055] The carriage 66 supports a horseshoe conductor 70 fitted to the top of the carriage 66 having laterally extending arms that form throws 54 a and 54 b . The arm forming throw 54 a of the horseshoe conductor 70 extends along the lateral axis 68 over throw pads 72 a . The arm forming throw 54 b of the horseshoe conductor 70 extends along the lateral axis 68 over throw pads 72 b - 72 d.
[0056] Throw pad 72 a is a conductive metallic plate connected to terminal 56 a and extending a distance along the lateral axis 68 sufficient so that it maintains contact with pole 54 a for the entire range of motion of the carriage 66 . Throw pad 72 c is a conductive metallic plate connected to terminal 56 b and contacting pole 54 b only when the hook 30 is in the second hook position (B). Throw pads 72 b and 72 d are insulators that support the pole 54 b when the hook 30 is in the hook positions (A) and (C), respectively, providing no electrical connection to terminal 56 b.
[0057] A helical compression spring 80 is girdled at a midpoint along its length by tabs 82 on the under side of the carriage 66 . The ends of the helical compression spring 80 are held by retaining posts 83 on opposed inside walls of carriage track 65 . The helical compression spring 80 in a relaxed state is longer than the separation of the retaining posts on the inside walls of the carriage track 65 so as to make the carriage 66 bi-stable in positions (A′) and (C′) corresponding to hook positions (A) and (C). Bi-stability means that the carriage 66 tends to move toward position (A′) when the carriage is near position (A′), and that the carriage 66 tends to move toward position (C′) when the carriage is near position (C′). When the carriage is in position (B′), it is also urged toward position (C′).
[0058] Accordingly, referring again to FIG. 3 , the hook 30 is stable in positions (A) and (C) when the lid 12 is open and is stable in positions (A) and (B) when the lid 12 is closed, the stability at position (B) being provided by the blocking action of the strike plate 24 .
[0059] The carriage 66 is attached to an arm 86 extending from a metal slug 88 held within solenoids 90 a and 90 b . The solenoids 90 a and 90 b may be alternatively energized through terminals 92 so that when solenoid 90 b is energized, the carriage 66 is pushed toward position (A′), and when solenoid 90 a is energized, the solenoid is pushed toward position (C′) and hence also (B′).
[0060] In this way, the lid 12 may be alternately locked or unlocked by electrical signals through terminals 92 . Upon ceasing of the signals through terminals 92 , the hook 30 is held in its current state by the bi-stable mechanism of spring 80 .
[0061] Referring now to FIG. 6 , the housing 48 of the lid lock, near the axle 46 , has an upper surface 100 having a through-hole 108 passing vertically through the housing 48 , two blind registration holes 110 flanking the through hole 108 , and two upwardly extending posts 106 displaced to one side of the line defined by the through-hole 108 and registration holes 110 , the posts 106 being separated by approximately the spacing to the registration holes 110 . The posts 106 include vertically extending metal slugs (not shown in FIG. 6 ) providing flux directors as will be described.
[0062] The upper surface 100 of the housing 48 fits against a lower surface 102 of the horizontal ledge 19 of the lid well 18 . A hole 104 may be cut in the horizontal ledge 19 to expose on the upper surface 100 the upwardly extending posts 106 , the through-hole 108 , and the two registration holes 110 .
[0063] A cap 112 placed on the hole 104 extends partially therethrough to receive the posts 106 within a cavity of the cap 112 . Registration pins 116 and a boss 118 extend downwardly from the lower surface of the cap 112 to be received within the registration holes 110 and the through-hole 108 respectively.
[0064] The boss 118 has a downwardly open threaded hole 120 . A machine screw 122 may be inserted upwardly through the through hole 108 from the bottom of the housing 48 to be received by the threaded hole 120 . Tightening of the threaded fastener 122 draws the housing 48 and cap 112 together sandwiching the horizontal ledge 19 there between and fixing the housing 48 to the washing machine 10 . Referring also to FIG. 7 , the cap 112 may include a core 128 of rigid thermoplastic over-molded with a soft elastomer 130 to provide an outward cushioning for the lid 12 and yet a firm purchase for the threaded fastener 122 .
[0065] The lid 12 of the washing machine 10 may be constructed of a shell of enameled steel having a concave lower surface receiving a plastic liner 124 providing a lower wall to the lid 12 . The liner 124 holds a bar magnet 126 on its inner surface where the bar magnet 126 may be shielded from exposure to water and the like. The bar magnet 126 is positioned so that when the lid 12 is closed against the horizontal ledge 19 , the bar magnet 126 rests above the cap 112 .
[0066] Referring to FIGS. 6 and 7 , the hole 104 in the horizontal ledge 19 of the washing machine 10 is sized to remove steel from a path between the magnet 126 and a reed switch 131 held in the housing 48 of the lid lock. The separation of the posts 106 extending up through the hole 104 (and thus the separation of the contained flux directors 109 ) is set to be substantially the same as the length of the bar magnet 126 extending between and above them and comparable to a length of the magnetic reed switch 131 positioned at the lower ends of the flux directors 109 .
[0067] When the lid 12 is closed, magnetic flux 132 is directed by the flux directors 109 to the reed switch 131 forming a complete magnetic circuit therewith. When the lid 12 is opened, the magnetic flux circuit is broken. The flux directors 109 allow displacement of the reed switch 131 deeper into the housing of the washing machine while still allowing the reed switch 131 to be activated with a magnet of modest size. The flux directors 109 also may serve to concentrate the magnetic flux 132 producing a better defined switching point as the lid is opened.
[0068] The reed switch 131 may communicate with conductors 134 that connect with pins added to pins 56 and 92 as have been described to provide a lid closed signal for activation of other circuitry associated with the washing machine.
[0069] Referring now to FIG. 8 , the rotation axis 44 of axle 46 may be located directly below a point of engagement (contact interface) of the hook 30 and the lid 12 . As so located, upward motion of the lid 12 initially along tangent 140 produces an upward vector 142 on axle 46 creating minimal torque on the housing 48 and mostly upward force against the lower surface of the ledge 19 augmenting that provided by screw 122 (shown in FIG. 6 ).
[0070] In addition, the contact interface (occurring between a lower surface of the tooth 28 of the hook 30 and the lower surface of the bolt hole 26 ) is such as to impart no torque or a slight engaging torque (counterclockwise in FIG. 8 ) to the hook 30 about axis 44 with upward motion of the lid 12 . This is accomplished simply by ensuring that the slope at the contact interface is zero or slightly canted inward (toward the lid 12 ) with respect to upward vector 142 . This design greatly simplifies construction of the lock mechanism and is particularly well suited for the bi-directional solenoid 90 described above because it allows the lock to function without continued activation of the solenoids 90 a or 90 b . The slight bi-stability added by the spring 80 described with respect to the contact set of FIG. 5 ensures that unintended movement with vibration and the like does not occur.
[0071] Referring now to FIG. 9 , sliding contact 54 , described above with respect to FIG. 5 , may include a downwardly sloping spring portion 150 terminating in a substantially horizontal contact surface 152 followed by an upwardly sloping ramp portion 154 . As shown in FIG. 2 , when the switch is in position (A), the horizontal contact surface 152 will be suspended in air or contacting an insulator.
[0072] As shown in FIG. 2 , when the switch is in position (B), the horizontal contact surface 152 will abut a corresponding horizontal contact surface 156 of stationary contact 72 . The area of the contact surfaces 152 and 156 may be large enough to provide desirable low contact resistance and suitable current carrying capability.
[0073] Normally separation of the contact surfaces 152 and 156 with over travel would require over travel equal to the length of combined lateral extent of contact surfaces 156 and 152 would be required for full disengagement of the contacts 54 and 72 . In order to provide greater precision in detect angular changes in the hook 30 (tied to the contacts 54 ) a cam surface 160 is located immediately following stationary contact 72 and formed of the material of the housing 48 also supporting stationary contact 72 . The cam surface 160 interacts with the ramp portion 154 of the sliding contact 54 moving the contacts 54 and 72 in separation in a transverse direction 162 perpendicular to the lateral sliding direction 159 . Thus a slight additional over travel motion completely separates the contacts without the need for them to slide laterally entirely out of engagement.
[0074] It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein, but include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims.
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A magnetic lid closure sensor uses a magnet sensor element mounted within the washing machine housing below the closed lid. Flux directors conduct flux from a magnet in the lid to the magnet sensor. A lock mechanism employs a hook engaging an aperture in the lid so that opening of the lid does not impart a torque to the hook such as would disengage it, allowing the hook to be activated and deactivated with a simple bi-directional solenoid.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to ground anchors, and more specifically to driven pivoting ground anchors.
2. General Background
Ground anchors, or earth anchors, of the driven and pivoting or tilting type are well known and generally include a main body portion having a leading edge adapted to be driven into the ground, a trailing edge including an outturned lip and a cable or rod or guide wire attachment point intermediate the leading and trailing edges generally positioned from about the midpoint of the overall length of the anchor or towards the trailing edge so that upon exertion of the force on the cable or attached rod or guide wire, after insertion of the anchor into the ground, the trailing edge's outturned lip will bite into the earth, causing the anchor to rotate or pivot to a locked position generally at a right angle to the withdrawal force.
Widely currently used driven pivoting anchors of the type described are available from the assignee of this application under its Duckbill trademark and generally employ a somewhat cylindrical main body portion having an attachment point intermediate its ends and having at its forward end a plurality of forwardly extending guiding plane surfaces which terminate in chiseled edges. The cylindrical body shaped member, at its trailing end, has a bore extending into the body of the cylindrical member for receipt of a drive rod for driving the anchor into the earth and is provided with an outturned lip on a side of the cylindrical body portion opposite the side having the cable or guide wire attachment point.
Such anchors are shown, for example, in U.S. Pat. Nos. 4,044,513 and 4,096,673, both of which are assigned to the assignee of this application. Improvements of such anchors are well known and include, for example, applicant's pending Design application No. 29/270,187, now Pat. No. D572546 issued Jul. 8, 2008 and U.S. Utility application Ser. No. 11/803,138 filed May 14, 2007, now U.S. Pat. No. 7,534,073 issued May 19, 2009.
Other variants of such anchors are sold, for example, by Foresight Products, LLC under trademarks Manta Ray and Stingray and employ extensive side projecting wings that extend backwardly and outwardly from the leading edges to a greater or lesser degree and provide greater resistance to withdrawal of the anchor after the anchor has been driven into the ground and rotated to the point where the wings lie substantially normal to the tension direction of the cable.
While such anchors, both of the wingless, small-winged and large wing design, have found successful utility in many applications, including use in connection with revetment and soil retaining mats. However, the chiseled or sharpened leading edges which facilitate penetration into the ground can, in certain instances, cause damage to certain types of soil retaining mats which are commonly used in turf reinforcement and ground stabilization. Such mats, often known as High Performance Turf Reinforcement Mat (HPTRM) of the type available under the mark Pyramat from Propex, Inc. or of the type shown, for example, in U.S. Pat. No. 5,616,399 entitled “Geotextile Fabric Woven or a Honeycomb Weave Pattern and having a Cuspated Profile after Heating,” may consist of individual strands essentially woven together and formed or fused to provide the mat. The strands are generally manufactured of plastics material. Other fabric-like woven mats utilizing similar or different materials are also known, as are non-woven mats. Where it is desired to anchor such mats to the underlying soil, the use of the previously known driven pivoting anchors can cause damage to the mat, particularly since the chiseled or sharpened leading edges will have a tendency to cut through the material of the mat, thereby weakening the mat.
It would therefore be an advance in the anchoring field to provide an anchor suitable for use with such turf reinforcement mats which could be driven through the mat with a reduced likelihood of damage to the mat.
SUMMARY OF THE INVENTION
The above advances are provided by the current invention by utilizing a driven pivotal anchor where the leading end is provided with a curved or rounded non-sharp leading end and flattened guiding plane edges.
In an embodiment of the invention a plurality of ribs or guiding plane leading edges extend forwardly of the generally cylindrical main body portion of the anchor with each edge being either blunt or rounded and with each edge converging to a common leading end which is generally rounded.
In an embodiment of the invention the leading edges projecting forward of the generally radial cylindrical main body portion are circumferentially spaced from one another and formed as the outside surface of ribs or guiding planes with the edges formed blunted or rounded and which converge to a common leading front end, the leading front end being rounded.
In an embodiment of the invention the generally cylindrical body member has four leading edges formed as orthogonal ribs or planes extending forwardly of the generally cylindrical body portion and tapering to a common leading end which is rounded generally in a partial spherical configuration.
It is therefore an object of the invention to provide a ground anchor having improved utility for use with mat structures having leading edge surfaces having a reduced tendency to damage the mat during driving of the anchor through the mat structure.
It is a further and more specific object of this invention to provide a driven pivoting anchor having a rounded or ball-like leading end.
These and other objects will be apparent to those of ordinary skill in the art from a description of the illustrated preferred embodiment, being understood that this is only one such embodiment of this invention and that many variations of shape and dimension are within the scope of this invention. Specifically the generally overall shape of the anchor, the shape of the main central body portion, the shape and extent of the side wings and the number of leading edges or ribs are all modifiable as is generally known to those of ordinary skill in the art and practice in differing commercially available embodiments of driven pivoting anchors.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the anchor of this invention.
FIG. 2 is a cross sectional view of the anchor of this invention taken along the lines 2 - 2 of FIG. 1 .
FIG. 3 is a cross sectional view of the anchor taken along the lines 3 - 3 of FIG. 1 .
FIG. 4 is a side schematic view of the driving of the anchor of this invention through a HPTRM mat and into the ground.
FIG. 5 is an enlarged perspective view of the undersurface of the mat illustrating how the nose of the anchor passes through the stranding of the mat.
FIG. 6 illustrates the locked position of the anchor after rotation from the driving position to the locked position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a ground or earth anchor 10 of the type often referred to as a driven and rotating or pivoting anchor in that the anchor is driven into the ground by force and after having being driven to the desired depth, a cable or rod attachment member attached to the anchor is pulled in a direction to withdrawal the anchor from the ground. Because of the design of the anchor and the position of the attachment of the cable or pulling rod to the anchor, the pulling of the anchor by the attachment member causes the anchor to undergo a pivoting or rotation in the ground towards a final position in which the longitudinal axis of the anchor is positioned more towards a position normal to the pulling cable or rod as shown in FIG. 6 .
Such anchors often include a main body section 11 , which may be generally cylindrically formed (other shapes are known in the art, including rectangular and oval), a leading edge 12 , a trailing edge 13 , a raised section 14 having means 2 for attachment of a cable, shackle, pivot bolt or the like, which may comprise or be attached to the withdrawing force member which causes the anchor to rotate or pivot from its driven position to its' final locked position. As shown in FIG. 1 , oftentimes the attachment means 2 is merely an opening through a raised rib 16 on one side of the main body portion 11 . The opening may receive a looped crimped cable end 40 or a shackle bracket or the like. Alternative structures are well known such as where the rib-like structure includes attachment means for receipt of the end of a T-shaped rod or other type of swiveling device. An open bore 17 in the trailing edge extends into the main body portion 11 terminating in a blind end 28 which may, as shown in FIGS. 2 and 3 , be flat or which may be rounded or otherwise configured. A driving rod 41 extends into the bore 17 and is used to drive the anchor into the earth. The driving rod may simply be impacted by a hammer for smaller anchors or may be driven by a pneumatic or hydraulic reciprocating power driver for larger anchors.
In the embodiment illustrated the main body portion is generally cylindrical and terminates at a leading end 11 a of the main body portion in a frustoconical section 11 b and four equally-distanced spaced ribs of which three, 15 , 17 , and 19 can be seen in FIG. 1 , the fourth being on the bottom opposite the rib 19 . Each of the ribs has an outer edge surface 18 and the rib surfaces 18 converge towards the leading end 12 . The outer edges 18 may be flat or blunt as shown in FIG. 1 or may be outwardly curved but preferably are not provided with a sharp edge. The ribs 15 , 16 , 17 may have different shapes. The ribs 15 and 17 extending back behind the frustoconical portion 11 b and converge into side wings 20 and 21 , which also preferably have rounded or non-sharp outer edges 22 . The rib 19 has its edge 18 extending back to the leading end of the generally conical section 11 a and blending into the top edge surface 14 of the raised rib 16 .
The four ribs, in this embodiment, converge together to a rounded nose 25 at the end 12 . Although different shapes can be provided for the nose, a part spherical or partial ball shape is preferred, although a parabolic shape or some other curvature is acceptable, it being important that the leading end 12 not be provided with a sharp edge. By providing a rounded leading edge 12 , the anchor is able to be driven through the mat 60 with minimal damage to the stranding of the mat and, in fact, for smaller anchors without severing any of the strands of the mat as the ball-like nose 25 pushes its way between the strands and non-sharp, rounded or blunt edges 18 force the strands apart as the main body portion of the anchor begins to pierce through the mat.
The side 31 of the anchor opposite the raised rib 16 is provided at its trailing edge 32 with an outturned lip 33 to facilitate pivoting during drawback, as is well known in the art.
In use the mat schematically shown at 60 is placed in position on the surface to be retained or secured and the ball-like nose of the anchor is placed against the mat surface and is then begun to be driven through the mat. As the ball-like nose, or rounded nose, enters the structure of the mat it will cause the strands of the mat to be pushed aside (see FIG. 5 ). As the anchor is driven further into the mat, the degree by which the strands are pushed aside will increase to allow the anchor to pass through the mat. In many instances utilizing normally stranded mats and standard smaller sized anchors equipped with the rounded or ball-like nose leading edge, the entire anchor can be pushed through the mat without breaking the strands of the mat. In other instances when slightly larger anchors are used one or more of the strands may be stretched beyond its limit and separate, but damage to the mat is minimal compared to the use of sharper or chiseled or leading edges or sharper edges extending backwardly from a leading point. While the use of blunted, rounded non-sharpened nose portions and leading side edges on the ribs and along the body may increase the resistance to driving of the anchor into the ground, when such anchors are used for soil erosion or soil stabilization, they are most often used in connection with looser or less resistant soil conditions such that the disadvantage, which may rise from an increase in resistance to driving in comparison to chiseled edged or sharpened edged anchors is minimized. After the anchor is driven into the ground it is rotated to its locked position by pulling upwardly on the attachment member. Thereafter the mat is secured to the attachment member by any suitable securing structure 63 .
It will therefore be understood from the above that this invention improve upon the prior art driven pivoting anchors by providing an intentionally rounded non-sharp leading nose or leading end which can be pushed through a woven or non-woven retaining mat with minimal damage to the mat.
Persons of ordinary skill in the art will understand that this invention may be practiced in embodiments other than that illustrated. It is not intended that this invention be limited to the particular anchor shape shown.
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An earth anchor of the pivoting type having an essentially cylindrical body, a blind bore extending thereinto from a trailing axial end of the cylindrical body and a leading edge projecting from a leading end of the body, the leading edge being formed as a rounded surface adapted for penetration through reinforcement paths while minimizing severing of the strands of the mat.
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RELATED APPLICATIONS
[0001] This application claims the benefit of priority of U.S. provisional patent application No. 61/273,282, filed Aug. 3, 2009, which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] This invention relates to high strength corrosion resistant steel and more particularly to the quenched and tempered high strength corrosion resistant cobalt-free steel for high stressed aircraft landing gears and structures.
BACKGROUND OF THE INVENTION
[0003] Aircraft landing gears and structures have stringent performance requirements. They are subjected to severe loading, corrosion, adverse environmental conditions and have complex shapes which vary from thin to thick sections. AISI 4340 steel and 300M steels are widely used for high stress aircraft landing gears and structures. These steels are not corrosion resistant and require protective coatings. Plating involves expensive toxic materials which pollute the environment and create health risks. Corrosion causes rust, cracks, and breaks and requires frequent inspections. Corrosion can fail aircraft landing gears and structures.
[0004] Ferrium S53 alloy U.S. Pat. No. 7,160,399 was primarily developed to provide high strength corrosion resistant steel for aircraft landing gears and structures. It is a cobalt-rich carbide precipitation strengthened corrosion resistant steel alloy. Ferrium S53 has several limitations (see Carpenter Technology Inc., Technical Datasheet, Carpenter Ferrium S53, www.cartech.com).
1. Ferrium S53 has corrosion resistance “Restricted” in salt spray and sea water tests. 2. Ferrium S53 requires passivation in 50% nitric acid solution to increase its corrosion resistance 3. Ferrium S53 has a yield strength (YS) of 220 ksi. 4. Ferrium S53 has high charge material costs. 5. Ferrium S53 requires complex and costly normalizing, annealing and heat treating procedures.
[0010] A low cost high strength martensitic stainless steel is disclosed in the published US patent application No 20090196784. The steel described in No 20090196784 has several disadvantages:
1. The claimed ductility and toughness of the steel in the published application are based on an 8% wt. concentration of chromium. A concentration of 8% wt. insufficient to pass the salt spray test. 2. Increasing the concentration of chromium above 8% wt. reduces the claimed ductility and toughness because of the low concentration of nickel (0.1 to 3.0% wt.). The low concentration of nickel is not enough to supply the required ductility with an elongation of more than 10%, a reduction of area of more than 30% and a toughness with impact toughness energy of more than 14 ft-lb, and a fracture toughness of more than 50 ksi×(square root over (in)) (hereinafter “ksi√in”). 3. Increasing the concentration of nickel above 3.0% wt. disturbs the balance between austenite and ferrite stabilizing elements of the low cost high strength martensitic stainless steel so an additional strong ferrite stabilizing element should be added; however a lack of an additional strong ferrite stabilizing element does not allow a stabilization of the balance. 4. Austenitizing temperature of the published martensitic stainless steel is only 1850 to 1900 F. The higher austenitizing temperature, 1925 to 2050 F of the present invention allows reducing the sizes of carbides and increasing the concentration of carbon in a solid solution. Higher concentration of carbon in the solid solution and smaller carbides supply the present invention higher ductility, toughness and strength compared to published martensitic stainless steel. 5. The published martensetic stainless steel does not have Tungsten (W). 6. The low cost high strength martensitic stainless steel has a low homogenized anneal temperature, 2100 to 2150 F that does not allow the conducting of fully homogenized distribution of the elements. The higher homogenized anneal temperature, 2200 to 2375 F allows the obtaining of homogenous microstructure of the steel of the present invention and as a result increasing mechanical properties.
[0017] The limitations of Ferrium S53 and the disadvantages of the steel of the US patent application No 20090196784 are overcome with the present invention.
SUMMARY OF THE INVENTION
[0018] The new steel (hereinafter “HSCR steel”) provides corrosion resistance in the salt spray and sea water tests, higher strength, lower cost charge materials, and lower cost normalizing, annealing, and heat treatment procedures than Ferrium S53. The HSCR steel is a cobalt-free, quenched and tempered steel with enhanced corrosion resistance for high stressed aircraft landing gears and structures.
[0019] The increased strength and corrosion resistance can reduce cost and weight by reducing sections thickness. It can also increase intervals between inspections. Fatigue cracks of HSCR steel have slower growth rates, thus lengthening the period for developing critical crack lengths.
[0020] The objects of the HSCR steel are accomplished by balancing the following:
[0021] 1. The ratios between the concentrations of carbon (C), nitrogen (N), austenite stabilizing nickel (Ni), manganese (Mn), and copper (Cu); ferrite stabilizing and carbides forming chromium (Cr), molybdenum (Mo), and tungsten (W); strong carbide forming and ferrite stabilizing vanadium (V), titanium (Ti), niobium (Nb), and tantalum (Ta); aluminum (Al); silicon (Si); and cerium (Ce).
[0022] 2. The modes of melting, homogenized annealing, and hot forging.
[0023] 3. The modes of normalizing, annealing, and heat treatment. The improved corrosion resistance, strength, ductility, and toughness of HSCR steel are verified by melting ingots, annealing and hot forging articles made from the ingots, normalizing the articles, annealing the articles, machining specimens, heat treating and testing the specimens.
[0024] The HSCR steel provides the following benefits over Ferrium S53:
[0025] 1. HSCR steel provides “Good” corrosion resistance in salt spray and sea water tests in the first embodiment and “Excellent” corrosion resistance in the second embodiment versus the “Restricted”corrosion resistance in salt spray and sea water tests of Ferrium S53 (see Carpenter Ferrium S53 Technical Data Sheet, www.cartech.com).
[0026] 2. The mandatory process of passivation in a 50% nitric acid solution to increase corrosion resistance Ferrium S53 is eliminated in the HSCR steel.
[0027] 3. The Rockwell C scale hardness of C 54 in Ferrium S53 is increased to 55.5 in the HSCR steel.
[0028] 4. The ultimate tensile strength of 288 ksi in Ferrium S53 is increased to at least 295 ksi in the HSCR steel.
[0029] 5. The yield strength of 220 ksi in Ferrium S53 is increased to at least 225 ksi in the HSCR steel.
[0030] 6. The 42 hrs of normalizing, annealing, and heat treatment in Ferrium S53 is reduced to an average of 24 hrs in the HSCR steel.
[0031] 7. The cost of normalizing, annealing, and heat treatment of HSCR steel is significantly lower than the cost in Ferrium S53 of normalizing, annealing, and heat treatment. The reduction of cost is due to 24 hrs time for these procedures in the HSCR steel versus 42 hrs time for Ferrium S53, as well as the use of 1 expensive refrigerating procedure in HSCR steel versus 3 expensive sub-zero cooling/refrigerating procedures in Ferrium S53.
[0032] 8. The amount of alloying elements in HSCR steel is reduced from 33% wt. in Ferrium S53 to 23.0% wt. or less in a first embodiment and 27.0% wt. or less in a second embodiment in HSCR.
[0033] 9. The expensive (14% wt.) cobalt (Co) in Ferrium S53 is eliminated in HSCR steel.
[0034] 10. The cost of charge materials per metric ton (per London Metal Exchange (LME) data, dated June, 2010) in HSCR steel is reduced to $2,300 or less in the first embodiment and $2,950 or less in the second embodiment from a $8,150 cost of the charge materials in Ferrium S53.
[0035] The HSCR steel differs from Ferrium S53 in the following ways:
[0036] 1. The HSCR steel is strengthened mainly by quenching whereas Ferrium S53 is strengthened mainly by carbide precipitation.
[0037] 2. The preferred method of normalizing and annealing of HSCR steel consists of: heating to about 1925 to 2025.degree. Fahrenheit (hereinafter “F”), holding for 2 to 8 hrs, and cooling; and heating to about 1100 to 1250 F, holding for 2 to 8 hrs, and cooling versus in Ferrium S53 heating at 1976 F, holding for 1 hr, air cooling, sub-zero cooling at −100 F for 60 min., air warming; and heating to 1256 F, holding for 8 hrs, and air cooling.
[0038] 3. The preferred method of heat treatment of HSCR steel consists of: austenitizing by heating to about 1925 to 2050 F, and holding for 0.5 to 1.5 hrs; quenching in oil, salt bath, or other environment with the predicted rate of cooling; refrigerating by cooling to about −120 to −40 F, holding for 0.5 to 1.5 hrs; tempering by heating to about 350 to 120 0 F, holding for 2 to 12 hrs, and cooling versus heat treatment in Ferrium S53 by: heating to 1985 F, holding for 60 min., oil quenching or equivalent; sub-zero cooling to −100 F, air warming; double-step tempering by heating to 934 F, holding for 3 hrs, oil quenching or equivalent, sub-zero cooling to −100 F, air warming, heating to 900 F, holding for 12 hrs, air cooling or equivalent ( FIG. 4 shows the diagrams of normalizing, annealing, and heat treatment of HSCR steel of Example 1 and Ferrium S53).
[0039] 4. Microstructure of HSCR steel consists of: fine packets of martensitic laths; retained austenite; and carbide particles after low tempering at 350 to 550 F and martensite, ferrite, retained austenite, and carbide particles after high tempering at 800 to 1200 F versus a martensitic microstructure with fine carbide particles of Ferrium S53.
[0040] 5.The amount of C in HSCR steel is 0.3 to 0.45% wt. in the first embodiment and of 0.2 to 0.45% wt. in the second embodiment versus 0.20% wt. in Ferrium S53.
[0041] 6. The amount of Cr in HSCR steel is 10 to 12.5% wt. in the first embodiment and of 10 to 14.5% wt. in the second embodiment versus of 10% wt. in Ferrium S53. Higher concentration of Cr, quenched and low tempered microstructure supply HSCR steel with a higher corrosion resistance than carbide precipitated Ferrium S53.
[0042] The HSCR steel provides the following benefits over the low cost high strength martensitic stainless steel of the US patent application No 20090196784:
[0043] 1. At the minimum reasonable concentration of Cr of 10% wt. or more, HSCR steel has higher ductility, toughness, and strength than the low cost high strength martensitic stainless steel.
[0044] 2. Austenitizing temperature of HSCR steel of 1925 to 2050 F is higher than 1850 to 1900 F of the low cost high strength martensitic stainless steel. Higher temperature allows dissolving carbides or reducing their sizes and increasing a concentration of carbon in a solid solution. Higher concentration of carbon in the solid solution and smaller carbides supply to HSCR steel higher ductility, toughness and strength compare with the low cost high strength martensitic stainless steel.
[0045] 3. Homogenize anneal temperature of HSCR steel of 2200 to 2375 F is higher than 2100 to 2150 F of the low cost high strength martensitic stainless steel. Higher temperature allows preventing segregation of elements in HSCR steel.
[0046] 4. A balance between austenite and ferrite stabilizing elements of HSCR steel is stabilized by adding a strong ferrite stabilizing and carbide forming W.
[0047] In summary, HSCR steel possesses for aircraft landing gears and structures an unique combination of corrosion resistance in salt spray and sea water tests and mechanical properties: an ultimate tensile strength of more than 295 ksi, a yield strength of more than 225 ksi, an elongation of more than 10%, a reduction in area of more than 30%, Charpy v-notch impact toughness energy of more than 14 ft-lb, a fracture toughness of more than 50 ksiVin.
BRIEF DESCRIPTION OF THE DRAWINGS
[0048] FIG. 1 is a table comparison of the compositions of HSCR steel and Ferrium S53.
[0049] FIG. 2 is a table comparison of the mechanical properties at room temperature of HSCR steel and Ferrium S53.
[0050] FIG. 3 is a table comparison of the corrosion resistance of HSCR steel and Ferrium S53.
[0051] FIG. 4 is a diagram of the normalizing, annealing and heat treatment of HSCR steel and Ferrium S53.
DETAILED DESCRIPTION OF THE INVENTION
[0052] The desired balance between corrosion resistance, strength, ductility, toughness, and cost was accomplished by selecting: the ratio of the austenite stabilizing, ferrite stabilizing, carbide forming elements, and other elements; melting, annealing, hot forging, normalizing and heat treatment.
[0053] The various elements act in the following ways.
[0054] Carbon (C) supports of formation of martensitic or martensitic-ferritic structure, nucleation and growth of carbides. Nitrogen (N) improves corrosion resistance and it in the same way as carbon can produce either solid solution strengthening or precipitation hardening. Austenite stabilizing elements: nickel (Ni) supplies the necessary ductility and toughness; manganese (Mn) is necessary for deoxidizing and stabilizing of austenite; copper (Cu) improves corrosion resistance, ductility, and machinability. Ferrite stabilizing and carbide forming elements: chromium (Cr) provides corrosion resistance, improves strength, hardness, and temperature resistance; molybdenum (Mo) increases toughness and improves corrosion resistance; tungsten (W) increases hardness, strength, and wear resistance. Strong carbide forming elements: vanadium (V) forms fine dispersed carbides and controls austenite grain growth; titanium (Ti), niobium (Nb), and tantalum (Ta) are more active carbide forming elements than V, a basic function of these elements is to inhibit austenite grain growth and to form carbides. Aluminum (Al) is the most effective element for deoxidizing, and it can be a part of HSCR steel. Silicon (Si) enhances the bonds between atoms in a solid solution and protects grain boundaries from growth of carbides. Cerium (Ce) prevents segregations of sulfur (S), phosphorus (P), and other detrimental elements at the grain boundaries, and it can be a part of HSCR steel.
[0055] The first embodiment of the invention is comprised of: 0.30 to 0.45% wt. carbon (C); 3.5 to 5.5% wt. nickel (Ni); 0.1 to 1.0% wt. manganese (Mn); 0.1 to 1.0% wt. copper (Cu); 10.0 to 12.5% wt. chromium (Cr); 0.5 to 1.0% wt. molybdenum (Mo); 0.05 to 1.0% wt. tungsten (W); 0.1 to 0.8% wt. vanadium (V); at least one element of titanium (Ti) and niobium (Nb) is a part of HSCR steel, wherein 0.01 to 0.5% wt. (Ti+Nb); 0.0 to 0.25% wt. aluminum (Al); 0.1 to 1.2% wt. silicon (Si); and a balance of iron (Fe) and incidental impurities. A sum of the alloying elements is 23% wt. or less.
[0056] The second embodiment of the invention is comprised of: 0.20 to 0.45% wt. carbon (C), 0.0 to 0.05% wt. nitrogen(N); 3.5 to 7.0% wt. nickel (Ni); 0.0 to 1.0% wt. manganese (Mn); 0.0 to 1.0% wt. copper (Cu); 10.0 to 14.5% wt. chromium (Cr); 0.5 to 2.0% wt. molybdenum (Mo); 0.0 to 1.0% wt. tungsten (W); at least one element of vanadium (V), titanium (Ti), niobium (Nb), and tantalum (Ta) is a part of HSCR steel, wherein 0.1 to 1.3% wt. (V+Ti+Nb+Ta); 0.0 to 0.25% wt aluminum (Al); 0.0 to 1.2% wt. silicon (Si); 0.0 to 0.01% wt. cerium (Ce); and a balance of iron (Fe) and incidental impurities. A sum of the alloying elements is 27% wt. or less.
[0057] HSCR steel for limited liability articles is melted by vacuum induction process. HSCR steel for high liability articles such as aircraft landing gears and structures require the vacuum induction and vacuum arc re-melting processes or vacuum induction and electro slag re-melting processes. The high liability articles require hot forging process.
[0058] The preferred method of practicing the invention is as follows:
1. Pour liquid HSCR steel into molds at 2750 to 3050 F and cool. 2. Homogenize anneal the ingots at 2200 to 2375 F for 9 to 18 hrs. 3. Hot forge or hot roll articles at start temperature 2150 to 2250 F and at finish temperature 1750 to 1950 F. 4. Anneal the articles at 1100 to 1250 F for 6 to 8 hrs and cool. 5. Normalize the articles by heating to 1925 to 2050 F, hold for 2 to 8 hrs, and cool. 6. Anneal the articles by heating to 1100 to 1250 F, hold for 2 to 12 hrs and cool. 7. Heat treat the articles by: austenitize at 1925 to 2050 F and hold for 0.5 to 1.5 hrs; quench in oil, salt bath, or other environment with the predicted rate of cooling and cool; refrigerate by cooling to −120 to −40 F, hold for 0.5 to 1.5 hrs, and warm; low temper by heating to 350 to 550 F, hold for 1 to 6 hrs, and cool; temper by heating to 550 to 800 F, hold for 1 to 6 hours and cool, or high temper by heating to 800 to 1200 F, hold for 3 to 12 hrs and cool.
[0066] To increase toughness and ductility of HSCR steel, isothermal quenching (marquenching) can be applied. To increase hardness and strength of HSCR steel, double quenching and double refrigerating can be applied. Tempering of HSCR steel can be conducted by combinations of the low tempering and the high tempering.
[0067] The present invention is explained and illustrated more specifically by the following non-limiting examples.
EXAMPLE 1
[0068] HSCR steel consists of in weight, % about: 0.39 of C, 4.0 of Ni, 0.50 of Mn, 0.50 of Cu, 10.0 of Cr, 1.0 of Mo, 0.25 of W, 0.30 of V, 0.10 of Ti, 0.85 of Si, sum of alloying elements equals to 17.89%, balance essentially Fe and incidental impurities.
[0069] HSCR steel is normalized, annealed and heat treated by the following mode: heating to 1950 F and holding for 6 hrs and air cooling; heating to 1150 F, holding for 4 hrs, air cooling; austenitizing at 1985 F for 60 min., oil quenching in oil and air cooling, refrigerating at −100 F for 60 min., and air warming, tempering at 350 F for 3 hrs, and air cooling.
[0070] Mechanical properties at room temperature are: HRC of 55, UTS of 295 ksi, YS of 227 ksi, El of 14%, RA of 38%, CVN of 16 ft-lb, K1c of 60 ksiVin.
[0071] HSCR steel possesses corrosion resistance in salt spray test per ASTM B117 (5% NaCl concentration at 95 F) after more than 200 hrs test duration.
[0072] Microstructure consists essentially of fine packets of martensitic lathes, retained austenite, and carbide particles; ASTM grain size number is 7 to 8.
EXAMPLE 2
[0073] HSCR steel consists of in weight, % about: 0.39 of C, 4.0 of Ni, 0.50 of Mn, 0.50 of Cu, 11.0 of Cr, 1.0 of Mo, 0.25 of W, 0.30 of V, 0.10 of Ti, 0.85 of Si, sum of alloying elements equals to 18.89%, balance essentially Fe and incidental impurities.
[0074] HSCR steel is normalized, annealed and heat treated by the following mode: heating to 1950 F and holding for 6 hrs and air cooling; heating to 1150 F and holding for 4 hrs and air cooling; austenitizing at 1985 F for 60 min., oil quenching and air cooling, refrigerating at −100 F for 60 min. and air warming, tempering at 350 F for 3 hrs and air cooling.
[0075] Mechanical properties at room temperature are: HRC of 55, UTS of 295 ksi, YS of 225 ksi, El of 11%, RA of 32%, CVN of 14 ft-lb, K1c of 55 ksiVin.
[0076] HSCR steel possesses corrosion resistance in salt spray test per ASTM 8117 (5% NaCl concentration at 95 F) after more than 200 hrs test duration.
[0077] Microstructure consists essentially of fine packets of martensitic lathes, retained austenite, and carbide particles; ASTM grain size number is 7 to 8.
EXAMPLE 3
[0078] HSCR steel consists of in weight, % about: 0.42 of C, 4.0 of Ni, 0.5 of Mn, 0.50 of Cu, 10.0 of Cr, 1.0 of Mo, 0.25 of W, 0.30 of V, 0.10 of Ti, 0.85 of Si, sum of alloying elements equals to 17.92%, balance essentially Fe and incidental impurities.
[0079] HSCR steel is normalized, annealed and heat treated by the following mode: heating to 1950 F and holding for 6 hrs and air cooling; heating to 1125 F, holding for 4 hrs and air cooling; austenitizing at 1985 F for 60 min., oil quenching and air cooling, refrigerating at −100 F for 60 min. and air warming, tempering at 400 F for 3 hrs and air cooling.
[0080] Mechanical properties at room temperature are: HRC of 56, UTS of 305 ksi, YS of 230 ksi, El of 11%, RA of 32%, CVN of 13 ft-lb, K1c of 50 ksiVin.
[0081] HSCR steel possesses corrosion resistance in salt spray test per ASTM B117 (5% NaCl concentration at 95 F) after more than 200 hrs test duration.
[0082] Microstructure consists essentially of fine packets of martensitic lathes, retained austenite, and carbide particles; ASTM grain size number is 7 to 8.
EXAMPLE 4
[0083] HSCR steel consists of in weight, % about: 0.42 of C, 4.0 of Ni, 0.5 of Mn, 0.50 of Cu, 11.0 of Cr, 1.0 of Mo, 0.25 of W, 0.30 of V, 0.10 of Ti, 0.85 of Si, sum of alloying elements equals to 18.92%, balance essentially Fe and incidental impurities.
[0084] HSCR steel is normalized, annealed and heat treated by the following mode: heating to 1950 F and holding for 6 hrs and air cooling; heating to 1150 F and holding for 4 hrs and air cooling; austenitizing at 1985 F for 60 min., oil quenching and air cooling, refrigerating at −100 F for 60 min. and air warming, tempering at 400 F for 3 hrs and air cooling.
[0085] Mechanical properties at room temperature are: HRC of 56, UTS of 305 ksi, YS of 230 ksi, El of 10%, RA of 30%, CVN of 13 ft-lb, K1c of 50 ksiVin.
[0086] HSCR steel possesses corrosion resistance in salt spray test per ASTM B117 (5% NaCl concentration at 95 F) after more than 200 hrs test duration.
[0087] Microstructure consists essentially of fine packets of martensitic lathes, retained austenite, and carbide particles; ASTM grain size number is 6 to 8.
EXAMPLE 5
[0088] HSCR steel consists of in weight, %: 0.39 of C, 5.5 of Ni, 0.5 of Mn, 0.5 of Cu, 10.0 of Cr, 1.00 of Mo, 0.25 of W, 0.30 of V, 0.10 of Ti, 0.85 of Si sum of alloying elements equals to 19.39%, balance essentially Fe and incidental impurities.
[0089] HSCR steel is normalized, annealed and heat treated by the following modes: heating to 1950 F and holding for 6 hrs and air cooling; heating to 1150 F and holding for 4 hrs and air cooling; austenitizing at 1985 F for 60 min., oil quenching and air cooling, refrigerating at −100 F for 60 min. and air warming, tempering at 350 F for 3 hrs and air cooling.
[0090] Mechanical properties at room temperature are: HRC of 54.5, UTS of 290 ksi, YS of 220 ksi, El of 15%, RA of 48%, CVN of 17 ft-lb, K1c of 65 ksiVin.
[0091] HSCR steel possesses corrosion resistance in salt spray test per ASTM B117 (5% NaCl concentration at 95 F) after more than 200 hrs test duration.
[0092] Microstructure consists essentially of martensite, ferrite, retained austenite, and carbide particles; ASTM grain size number is 6 to 8.
EXAMPLE 6
[0093] HSCR steel consists of in weight, % about: 0.27 of C, 3.5 of Ni, 0.5 of Mn, 0.5 of Cu, 11.5 of Cr, 2.0 of Mo, 0.25 of W, 0.30 of V, 0.10 of Ti, 0.85 of Si, sum of alloying elements equals to 19.77%, balance essentially Fe and incidental impurities.
[0094] HSCR steel is normalized, annealed and heat treated by the following mode: heating to 1950 F and holding for 6 hrs and air cooling; heating to 1150 F and holding for 4 hrs and air cooling; austenitizing at 1985 F for 60 min., oil quenching and air cooling, refrigerating at −100 F for 60 min. and air warming, tempering at 935 F for 4 hrs and air cooling.
[0095] Mechanical properties at room temperature are: HRC of 54, UTS of 290 ksi, YS of 220 ksi, El of 11.0%, RA of 32%, CVN of 14 ft-lb, K1c of 55 ksiVin.
[0096] HSCR steel possesses corrosion resistance in salt spray test per ASTM B117 (5% NaCl concentration at 95 F) after more than 200 hrs test duration.
[0097] Microstructure consists essentially of martensite, ferrite, retained austenite, and carbide particles.
EXAMPLE 7
[0098] HSCR steel consists of in weight, % about: 0.25 of C, 3.5 of Ni, 0.5 of Mn, 0.5 of Cu, 12.5 of Cr, 2.0 of Mo, 0.25 of W, 0.30 of V, 0.10 of Ti, 0.85 of Si, sum of alloying elements equals to 20.75%, balance essentially Fe and incidental impurities.
[0099] HSCR steel is normalized, annealed and heat treated by the following mode: heating to 1950 F and holding for 6 hrs and air cooling; heating to 1150 F and holding for 4 hrs and air cooling; austenitizing at 1985 F for 60 min., oil quenching and air cooling, refrigerating at −100 F for 60 min., and air warming, tempering at 935 F for 3 hrs and air cooling.
[0100] Mechanical properties at room temperature are: HRC of 54, UTS of 290 ksi, YS of 220 ksi, El of 10.0%, RA of 30%, CVN of 12 ft-lb, K1c of 50 ksiVin.
[0101] HSCR steel possesses corrosion resistance in salt spray test per ASTM B117 (5% NaCl concentration at 95 F) after more than 200 hrs test duration.
[0102] Microstructure consists essentially of martensite, ferrite, retained austenite, and carbide particles.
[0103] Although only several examples have been described, it is obvious that other examples can be derived from the presented description without departing from the spirit thereof.
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A quenched and tempered high strength, corrosion resistant steel suitable for aircraft landing gears and structures, having a unique combination of mechanical and corrosion resistant properties: ultimate tensile strength of 295 to 305 ksi, yield strength of 225 to 235 ksi; elongation of 12 to 13.5%, reduction of area of 34 to 36%, Charpy v-notch impact toughness energy of about 14 to 16 ft-lb, fracture toughness of 55 to 60 ksiVin, and corrosion resistance in salt spray test.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the dyeing of natural proteinaceous and synthetic polyamide fibers, particularly the normal and specialty nylons.
2. Description of the Prior Art
The dyeing of nylons--manufactured fibers in which the fiber-forming substance is any long chain synthetic polyamide having recurring amide groups as part of the chain--may, depending on the specific type of nylon involved--be accomplished with many different classes of dyes, e.g.: basic, acid, disperse, direct, etc. The acid and disperse dyes are in wide commercial use and the dye compositions of this invention utilize these classes of dyes. For reasons of speeding of dyeing, maximum utilization of dye and improving evenness of color throughout the dyed fiber, these dyes are generally used in conjunction with "assistants" (sometimes designated as "carriers") - materials which promote the attainment of speedy dyeing, maximum dye utilization, etc. There are a number of assistants commercially available but the experiments carried out in the work leading to this invention indicated that, generally, an assistant effective with acid dyes is not optimum for disperse dyes and vice versa. Use of only one assistant for both acid and disperse dyeing would be advantageous to a dyer in that inventories of different assistants could be reduced and there would be less possibility of erroneous selection of assistant.
It has now been found that combining dibenzyl ether and an alkylene carbonate, neither of which are effective assistants for both acid and disperse dyeing of nylon and other fibers, results in combinations which are synergistically effective with both types of dyes.
SUMMARY OF THE INVENTION
In accordance with this invention there have been found dye assistants effective with both acid and disperse dyes, such assistants comprising a combination of (a) dibenzyl either with a (b) compound of the formula: ##STR2## wherein x is selected from the group consisting of hydrogen, methyl and ethyl.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Dibenzyl ether alone was found to be an effective dyeing assistant for acid dyeing of specialty nylons comprising 40% or greater of the condensation product of 4,4'-diamino-dicyclohexyl methane and decanodicarboxylic acid having the basic repeating unit: ##STR3## however, it did not give optimum results with disperse dyes. With this specialty nylon, a representative alkylene carbonate did not give optimum results with either acid or disperse dyes. However, combinations of dibenzyl ether with certain alkylene carbonates gave assistants whose performance could not be predicted by a mere arithmetic averaging of the properties of the individual constituents, since the combinations generally were effective for both acid and disperse dyeing of the aforedescribed specialty nylons.
It was further observed that, when dyeing the aforedescribed specialty nylon, dye compositions comprising the disperse dye Eastman Polyester Navy Blue 2R-LSW (Eastmand Chemical Products, Inc.; C.I. Disperse Blue 79) with the combinations as assistants gave commercially acceptable dyeing results. This contrasts with the outcome found when the individual members of the combinations were used with this dye: all gave unacceptable results due to the dyed fiber being a blue-gray hue rather than a navy blue, or due to uneven dyeing, or due to incomplete utilization of the dye.
These combinations may be comprised of from about 90 weight percent dibenzyl ether, 10 weight percent alkylene carbonate to about 10 weight percent dibenzyl ether, 90 weight percent alkylene carbonate, but preferably dibenzyl ether comprises from about 30 to 70 weight percent of the combination with the alkylene carbonate comprising 70 to 30 weight percent. The lower alkylene carbonates - ethylene, 1,2 propylene, 1,2 butylene--are useful in this invention, however 1,2 propylene carbonate (hereinafter referred to as "propylene carbonate") is preferred.
The assistants of the present invention are essentially insoluble in water and to be effective in the normally-used aqueous dye baths must be emulsified or otherwise dispersed in water. A convenient method of supplying these assistants for industrial use in as emulsifiable concentrates--a mixture of emusifying agents and assistants which, when stirred with a minimum of energy into water, will give a usable emulsion. While the amount and type of emulsifying agent for specific dyes and fibers is determined by experience and experiement, a generally useful emulsifier system is one containing both anionic and non-ionic emulsifiers. Typical of anionic emulsifiers is the isopropylamine salt of dodecylbenzene sulfonic acid, of non-ionic emulsifiers is a polyoxyethylene derivative of castor oil.
Various amounts of the aforedescribed assistants can be used in order to accomplish the results of the present invention. The use of excess assistant while possible, is wasteful since after an efficient amount has been added, no additional beneficial results are achieved by an excess. The amount of assistant to be used, expressed as a weight ratio of assistant-to-dye should be between about 1:1 and 20:1, the precise amount depending on the fiber-dye-process conditions. (By "assistant" is meant the active components of a formulation, e.g. in Example I, the 80 weight percent emulsifiable concentrate contains 80% "assistant"). The amount of dye in the dye bath is commonly expressed as a weight percentage on-weight-of-fiber (OWF) and may be from about 0.1 to 10 with OWF percentages of from 1 to 5 being typical of commercial practice.
"Acid dyes" are in general salts of organic acids wherein the colorant portion of the dye is the anionic (negatively charged) moiety. The assistants of this invention are useful with fibers which can be dyed effectively with acid dyes, such fibers include the natural proteinaceous fibers such as wool and silk and the synthetic polyamide fibers such as the different types of nylons (e.g. nylon 66 or the aforedescribed specialty nylons).
"Disperse" dyes are called so because they are almost insoluble in water--which is the most commonly used dyeing medium --and are applied in the form of finely-divided particles which are dispersed in water. The dye assistants of this invention are useful also in the dyeing of fibers for which disperse dyes are used. Such fibers include modified regenerated natural products such as secondary cellulose acetate and cellulose triacetate, and totally synthetic fibers such as the polyesters (e.g.--the long chain condensation product of terephthalic acid and ethylene glycol) and the synthetic polyamides (e.g.--nylon 66 or the aforedescribed specialty nylon).
The actual procedures described below in Example I for the applying of dyes to fibers using the dye assistants of the present invention, are typical of those suggested for superatmospheric pressure dyeing of the aforedescribed specialty nylons which require relatively rigorous dyeing conditions. (See, for example, pp. 321-327, "Book of Papers, 1974 National Technical Conference" published in 1974 by the American Association of Textile Chemists and Colorists). Less rigorous conditions would be usable with nylons such as nylon 66 into which dyes diffuse more rapidly. With the appropriate modifications in processing, other methods of applying the dye --such as printing, padding, spraying onto the fiber, etc. are usable.
In addition to dyes and dye assistants, dyeing formulations usually contain various auxiliary agents. These agents can include emulsifiers, anionic, cationic or non-ionic, for emulsifying or dispersing the dye and dye assistant in water. pH control may be accomplished by the addition of formic acid, acetic acid and the like. Sodium phosphate may be used for water softening, natural or artificial gums may be used to control the thickness of the formulation, surfactants may be used to improve wetting of the fabric, etc. The decision as to what and how much auxiliary to use and the sequence of addition usually rests with the dyemaster, his decisions being made on the basis of his experience of dyeing in general and of the fibers and dyes used in a particular dyeing operation. In Example I, a blend of the isopropylamine salt of dodecylbenzene sulfonic acid and a polyoxyethyated castor oil is used to emulsify the dye assistants, sodium hexametaphosphate is used for wetting purposes, mono-sodium phosphate is used as a buffer for pH control and sodium N-methyl-N-oleoyl taurate is a surfactant/emulsifier. This invention, however, is not limited to these particular auxiliaries nor the proportions used.
The compositions of the present invention contemplate dye preparations containing the aforedescribed combinations as essential dye assistants and either an acid or a disperse dye. The pH of these compositions may be any value commonly used for acid or disperse dyeing--typically from about 3 to slightly below 7; the dyebath of Example I has a pH of about 6.5. These compositions can have as optional additional components the aforementioned general type of auxiliary agents to control the physical and chemical conditions of the dyeing. The specific additives to be used and their amounts depend upon the particular fiber to be dyed and on the operating conditions chosen.
The following Example I illustrates methods of preparing and applying the dye compositions of the present invention, which is not limited thereto.
The dyes used in the present invention and identified in Example I are representative of the classes of acid and disperse dyes and were chosen to give the three primary colors of red, blue and yellow since by suitable combination of these colors it is possible to obtain a wide variety of hues. Unless otherwise specified all temperature are in degrees Celsius, weights in grams and volumes in milliliters. Where "dye assistant" is specified, the reference is to the emulsifiable concentrate or aqueous dispersion; with the assistants of this invention, this concentrate contains 80 weight percent active components, 20 weight percent emulsifiers.
EXAMPLE I
Preparation of Disperse or Acid Dyebath Composition and Dyeing Procedure
Experimental dye assistants were first formulated into emulsifiable concentrates by admixture at 30°-40° C. with emulsifiers to make a homogeneous:
______________________________________Emulsifiable Concentrate______________________________________Dye Assistant 80 parts weightTrydet 3300 15Trylox CO-40 5 100______________________________________
(Trydet 3300 is the isopropylamine salt of dodecylbenzene sulfonic acid, Trylox CO-40 is a polyoxyethylene derivative of castor oil. Both materials are products of Trylon Chemical Corporation, a division of Emery Industries, Inc.).
To an Atlas Electric Devices Company's Launder-Ometer, Model LHTP stainless steel test container were charged:
Approximately 300 ml tap water at about 50° C.
5 ml of 3% (wt) solution of sodium hexametaphosphate
5 ml of 3% (wt) solution of monosodium phosphate
5 ml of 3% (wt) solution of sodium N-methyl-N-oleoyl taurate*
1 ml of an aforedescribed emulsifiable concentrate of dye assistant
(The tap water used in this example had a hardness of about 40 parts per million, but the invention is not limited to water of this hardness. The degree of hardness permissible depends upon the conditions peculiar to a particular dye formulation/fiber combination and a dyemaster will use water softeners to adjust hardness if he deems this necessary).
The above mixture was stirred until it became homogeneous. Then 0.2 gram (2 percent on-weight-of-fiber) of the dye to be used in the experiment was dissolved in about 84 ml of lukewarm tap water and this solution added to the above mixture. This final mixture was the completed dyebath and was, if necessary, adjusted to a volume of 400 ml by addition of tap water so as to give, with a 10 gram fiber sample, a bath-to-fiber ratio of 40:1. A 10 gram sample of the aforedescribed specialty nylon (type 470 or type 472, either giving substantially the same dyeing results, made by E. I. DuPont de Nemours & Company, Inc. and in the form of swatch of Qiana® (Dupont's T.M.) fabric obtained from Testfabrics, Inc., their Style 324) was next added to the dyebath and the preparation stirred. The stainless steel container was then sealed pressure-tight and placed in the Launder-Ometer which was then switched "on" (at all times during the "on" condition, the dyebath was stirred by reason of its container being continually rotated in a manner which regularly inverted and righted it thus imparting a sloshing motion to the contained dyebath). The Launder-Ometer bath temperature was then rapidly (about 15 minutes) raised from room temperature (20°-25° C.) to 70° C. at which temperature the programmed heating mode of the Launder-Ometer was used to bring the bath temperature from 70° C. to 100° C. over a period of 45 minutes and from 100° C. to 130° C. over a period of 30 minutes. The bath was then held for one hour at 130° C. with the container contents under autogeneous pressure.
At the conclusion of this period, the programmed cooling mode of the Launder-Ometer was used to cool the bath to approximately 50° C. over a period of 50 to 60 minutes and the Launder-Ometer switched to "off".
After cooling, the container was removed from the Launder-Ometer, and emptied of its liquid contents. The degree of exhaustion of the dye was visually noted and observations made of loss of dyebath or of presence of glycerin in the container--both of which conditions were caused by faulty sealing of the container. No data were taken from runs showing such signs of leakage; the experiment was repeated until a satisfactory run was obtained.
The swatch was rinsed in lukewarm tap water and then washed by adding to its container 200 ml of solution, at 70° C., containing 1% of an alkyl aryl polyether surfactant (Triton X-100, product of Rohm & Haas Company) and 1% sodium pyrophosphate (Na 4 P 2 O 7 ·10H 2 O) and soaking for 10 minutes. The swatch was then washed with lukewarm tap water until free of the surfactant/phosphate wash solution. After drying at room temperature from 16 to 24 hours, the swatch was heated in a forced draft oven for about 3 minutes at 193° C. in order to free it of the last trace of dye assistant and to stabilize the dye. It was then ironed to help eliminate wrinkles and the effectiveness of the dye assistant evaluated. This effectiveness is a combination of a number of performance factors which a dye-master would not normally measure quantitatively, but would subjectively evaluate and integrate to get an overall estimate of the merit of the assistant. These factors include: completeness of exhaustion of dye from the dyebath (the more complete, the better the assistant) trueness of hue and intensity or saturation of the color of the dyed fiber and evenness of dyeing--i.e. there are no darker or lighter areas on the dyed fiber. The above factors were evaluated for each dye and dye assistant combination tested in this experimental work. With acid dyes, the evaluation of color trueness and intensity was made using only the experimentally dyed fabric itself, with disperse dyes the colors of the dyed fabrics were judged against an array of samples of polyester fabric dyed with the same dyes and various assistants and covering the range of assistant effectiveness from highly effective to low effectiveness. While a dyemaster usually would classify an assistant as highly effective or moderately effective or of low effectiveness with no attempt to further quantitate his judgement, a numerical scale is adopted here to better differentiate differences between assistants. This scale is shown in Table I. A rating of 4 or higher is considered to indicate an assistant with commercial utility--with the proviso however, that an off-hue color is not commercially acceptable even though consideration of other factors might lead to a rating of 4 or above.
The procedure detailed in Example I was used to prepare numerous dye compositions utilizing the following three acid and three disperse dyes:
______________________________________ExperimentalDesignation DYE DESCRIPTION______________________________________1. Capracyl Red B (C.I. Acid Red 182)2. Supralan Yellow NR (C.I. Acid Yellow 121, C.I. No. 18690)3. Alizarine Supra Blue A (C.I. Acid Blue 25, C.I. No. 62055)4. Genacron Red B (C.I. disperse Red 88)5. Eastman Polyester Yellow GLW (C.I. disperse Yellow 42, C.I. No. 10338)6. Eastman Polyester Navy Blue 2R-LSW (C.I. disperse Blue 79)______________________________________
The following individual materials, and combinations were employed as dye assistants. Comparison of the results for the individual materials with those for the combinations illustrates the synergistic effects found and the particular effectiveness of the combinations with Eastman Polyester Navy Blue 2R-LSW (C.I. disperse Blue 79):
TABLE I______________________________________Experimental Active Component of AssistantDesignations (Ratios by Weight)______________________________________A Dibenzyl EtherB Propylene CarbonateC 7/3 Dibenzyl Ether/Propylene Carbonate______________________________________EFFECTIVENESS RATINGS OF DYE ASSISTANTS DYES,DYE ASSISTANTS, EXPERIMENTAL DESIGNATIONSEXPERIMENTAL ACID DISPERSEDESIGNATIONS 1 2 3 4 5 6______________________________________A 7 7 7 6 6 2-3.sup.(1)B <4 5 6 7 7 <4C 6 8 8 8 8 9______________________________________LegendNumerical Rating Effectiveness______________________________________1 Low34 Medium567 High89______________________________________ Note: .sup.(1) BlueGray Hue
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Compositions and methods for dyeing natural proteinaceous and synthetic polyamide fibers, particularly wool, silk and nylons, utilizing dye assistants effective with both acid and disperse dyes, such assistants being a combination of (a) dibenzyl ether with (b) a compound of the formula: ##STR1## wherein x is selected from the group consisting of hydrogen, methyl and ethyl.
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CROSS-REFERENCE TO RELATED APPLICATION
This divisional patent application corresponds to parent co-pending U.S. patent application Ser. No. 08/1759,494 filed Dec. 4, 1996, entitled "Wavelet Hidden Markov Modeling Method for Cardiac Event Wave Detection and Arrhythmia Analysis" to Sun et al. Reference is hereby made to commonly assigned, co-pending U.S. patent application Ser. No. 08/579,902, filed Dec. 4, 1996 entitled "AN ADAPTIVE AND MORPHOLOGICAL SYSTEM FOR DISCRIMINATING P-WAVES AND R-WAVES INSIDE THE HUMAN BODY" naming Weimin Sun et al. as inventors, and having Attorney Docket No. P-3751, the disclosure of which is hereby incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
The present invention relates to facilitation of the automated discrimination of cardiac events of interest, including P-waves, R-waves, T-waves, and specific arrhythmic sequences, in electrocardiograph (ECG) lead signals derived from one or more skin surface electrodes or in one or more electrogram (EGM) derived from one or more electrodes implanted in a patient for data storage in an implantable monitor or to control operations of an implantable cardiac stimulator through the use of Hidden Markov Modeling techniques.
BACKGROUND OF THE INVENTION
In the medical fields of cardiology and electrophysiology, many tools are used to assess the condition and function of a patient's heart from observed frequency, polarity and amplitudes of the PQRST complex associated with a heart cycle. Such tools include the classic external ECG systems for displaying and recording the characteristic 12 lead ECG signals from skin electrodes placed on the patient's chest and limbs, ambulatory ECG Holter monitors for continuously recording the ECG or segments thereof from a more limited set of skin electrodes for a period of time, and more recently developed completely implantable cardiac monitors or cardiac pacemakers and pacemaker/cardioverter/defibrillators (PCDs) or more limited cardioverter/defibrillators (ICDs) having the capability of recording EGM segments or data derived from atrial and ventricular EGMS (A-EGMs and V-EGMs) for telemetry out to an external programmer for external storage and display. The episodes of bradycardia or tachyarrhythmia are typically determined by trained personnel examining the real time or recorded ECGs and EGMs for inadequate, slow heart rates or for excessive or high and irregular heart rates. Through the analysis of patient symptoms and the ECG or EGM, a diagnosis may be made and treatment prescribed, including, in many instances, the implantation of cardiac pacemakers, ICDs or PCDs programmed to detect and respond to the particular episode. As set forth below, the implanted system must be able to appropriately discriminate between the P-wave, R-wave and T-wave in the A-EGM and V-EGM, diagnose any arrhythmic episode and respond appropriately.
Typically, when the EGM or ECG is visually examined, the R-wave is identified as the characteristic marker for a given atrial or ventricular heart cycle, the R--R intervals between successive R-waves are measured to determine a heart rate, and the heart rate is compared against pre-determined rate limits to initially classify the heart rate as normal, excessive or inadequate. Inspection for the occurrence, timing and polarity of the associated P-wave and T-wave is made by marking windows from the R-wave and looking for characteristic deviations in the ECG amplitude in those windows. Over a sequence of successive heart cycles, the regularity of the heart rate and the association of P-waves to R-waves are also examined. The existence and nature of arrhythmic episodes can be determined by such exhaustive visual inspection and analysis, assuming that the episode is correctly recorded and optimally if the contemporaneous symptoms can be described by the patient.
In the context of the external ECG, a great deal of effort has been expended over the years to automate the analysis, particularly the analysis of lengthy Holter monitor ECG tapes. Classical approaches taken have included morphology or template matching and feature vector classification to classify QRS complex morphology after R-wave detection and R--R interval determination. Reliable automatic detection of the P-wave using these techniques has not been particularly successful.
More recently, the Hidden Markov Modeling technique has been used in the effort to automate the analysis of ECG recordings to identify the characteristic P-waves and R-waves and to classify heart rhythm. Hidden Markov Modeling is a stochastic technique that has been used very successfully in speech recognition as described by Rabiner, L. R., in "A Tutorial on Hidden Markov Models and Selected Applications" published in Speech Recognition, IEEE Proceedings 1989; 77:257-286, incorporated herein by reference in its entirety. Applications of Hidden Markov Modeling techniques to analysis of the external ECGs is described, for example, by Coast, D. A. et al., in: (a) "Use of Hidden Markov Models for Electrocardiogaphic Signal Analysis", J. Electrocardiol 1990; 23(suppl): 184-191; (b) "An Approach to Cardiac Arrhythmia Analysis Using Hidden Markov Models", IEEE Trans Biomed Eng 1990; 37:826-836; and (c) "Segmentation of High-Resolution ECGS Using Hidden Markov Models", IEEE, I-67-70, 1993, all of which are incorporated herein by reference in their entireties. A further article by Thoravel, L. et al., entitled "Heart Signal Recognition by Hidden Markov Models: The ECG Case", in Meth. Inform Med., 1994; 33:10-14, is also incorporated herein by reference in its entirety.
In Hidden Markov Modeling (HMM), the state (or event) sequence of interest is generally not observable, but there is an observable sequence which is statistically related to the interested state sequence from which it is to be inferred. HMM involves two probabilistic functions wherein one represents the occurrence of an interested state (or event) sequence and the other represents the occurrence of an observable sequence related to the state sequence. In the application of HMM techniques to the ECG, it is relatively easy to sample and digitize the ECG values to develop an observation sequence of sample amplitude values. The "hidden" state sequence to be inferred from the sampled observation values is the actual electrical activation sequence of the heart.
The normal heart PQRST electrical activation sequence with intact A-V activation is fairly predictable in shape with the P-wave, R-wave and T-wave events occurring in sequence in the range of normal heart rates and is readily recognized by visual examination of the ECG or transmitted out EGM. Such a sequence is shown in the ECG tracing in FIG. 1. Even this sequence, however, is not as readily identified automatically as described above. In addition, when an A-V dissociation occurs, e.g. A-V block or spontaneous ventricular ectopic events, the PQRST activation sequence is disrupted, and a trained specialist is required to identify the underlying arrhythmia even by sight. In atrial and ventricular tachyarrhythrias, the shapes of the P-waves and R-waves are distorted from the normal sinus rate shapes. The objective of HMM for event detection and arrhythmia analysis is to detect and differentiate the specific waves and arrhythmic events in terms of state sequences from the observation sequences.
FIG. 1 is representative of the technique of applying HMM to arryhythmia detection as described in the above-referenced Coast et al. articles. The ECG is sampled at a sample frequency, e.g. 256 Hz. or about every 4 ms, and the sampled values constitute a set of observations that are related to the "states" of a normal left to right HMM depicted in the bottom tracing of FIG. 1 (the number of observations depicted in FIG. 1 are reduced for simplicity of illustration). The observations are characteristic of Baseline (b), Q-wave (q), R-Wave (r), S-wave (s) T-Wave (t), and P-Wave (p) states. These observations are matched against the left to right states of this normal ECG HMM sequence as well as those left to right HMM sequences created to represent differing arrhythmias, e.g. A-V dissociation, ectopic atrial or ventricular beats or the like, to make an assessment as the closest match of the observations in the sequence to the HMM representing a particular rhythm. The differing HMMs are created through a training process from the observation value sets characteristic of each sequence.
In the HMM analysis of cardiac arrhythmias, the sampling rate of the ECG must be fairly high (256 Hz or above) in order to retain morphological information. The HMM analysis is relatively robust and lends itself to discrimination of a number of states of the ECG or EGM representing P-waves,R-waves, T waves and associations thereof characteristic of various tachyarrhythinas as described in the above cited Coast et al. articles. However, the state number and the observation sequence length, for a given time duration of ECG data, is very large. For example, assuming a patient heart rate of 60 beats per minute, the sampling rate is 256 Hz, and two states such as the P-wave and the R-wave state are sought to be determined, the normal HMM has an equivalent state number N=256 and an observation sequence length T=256. In general, the HMM analysis for two states requires a computation proportional to N 2 (T)=1.68×10 7 . In cardiac arrhythmia analysis by HMM as taught by Coast et al. in article (a) page 191, the actual computation time to complete the HMM analysis using the efficient Viterbi algorithm and a sample rate of 256 Hz took about five times real time or 2.5 hours for a 35 minute ECG tape. Use of hardware accelerators is suggested, but testing apparently has not been reported.
In the above-referenced Thoravel et al. article, other difficulties with the Coast et al. published approaches are raised and solutions explored, particularly devoted to the improvement of the detection of the P-wave from ECG samples employing Modified Continuously Variable Duration HMMs (MCVDHMMs). The ECG sample observations are processed to extract candidate "waves" using a wavelet multiresolution analysis performed on a non-linear transform (NLT) of the ECG samples. The NLT generates transitories with an inflection point corresponding locally to a potential wave peak (observation sample value), and the wavelet transform (W. T.) of the non-linearly transformed observation samples results in magnitude and phase values that can be examined to extract wave features from baseline or "interwave" features. The wave features and sequences can be employed in the MCVDHMM process to identify P-waves, R-waves, etc. and particular rhythms.
While this process may offer advantages over the HMM techniques of Coast et al., still involves a heavy computational burden on the order of that described above for the Coast et al. technique. Consequently, the BMM and MCDVHMM computation is very expensive, making automatic analysis of ECGs still extremely time consuming and making real time processing of EGM waveforms in an implantable system virtually impossible with current technology.
In this regard, there is a needbin implantable, dual chamber, pacemakers, ICDs and PCDs for improved discrimination of P-waves and R-waves in near real time, so that the operations of the implantable pulse generator (IPG) can accurately respond to the underlying current heart rhythm. Typically in such dual chamber IPGs, the amplitude and frequency of the sensed atrial and/or ventricular incoming electrogram signals (A-EGM and V-EGM) are employed in the attempt to distinguish R-waves, P-waves and T-waves from one another and from noise artifacts or other interference. The A-EGM is sensed from a unipolar or bipolar, atrial lead having one or two pace/sense electrodes in contact with the atrium, and the V-EGM is sensed from a unipolar or bipolar ventricular lead having one or two pace/sense electrodes in contact with the ventricle. The atrial and ventricular sense amplifiers employ sense criteria for distinguishing valid P-waves and R-waves, respectively, from far field R-waves and P-waves, respectfuilly, and electrical noise and artifacts. The filtered A-EGM and V-EGM signal amplitudes are compared against atrial and ventricular sense thresholds, and A-SENSE and V-SENSE events are declared when the A-EGM and V-EGM signal amplitudes exceed the respective thresholds.
The detection of R-waves in the V-EGM is fairly uncomplicated, because the R-wave amplitude usually exceeds the far field P-wave amplitude and most noise signals by a margin allowing the setting of a high ventricular sense threshold. However, because the amplitude of the P-wave is significantly lower than that of the QRS complex and particularly the amplitude of the R-wave in the V-EGM, the atrial sense threshold may be set lower than the ventricular sense threshold. Consequently, the intrinsic R-wave and the ventricular pace (V-PACE) triggered R-wave often appear in the A-EGM conducted by the atrial lead to the atrial sense amplifier and often have an amplitude exceeding the P-wave sense threshold. In this context, the R-wave appearing in the A-EGM signal is referred to as the "far field R-wave", and the sensing of such far field R-waves is referred to as "oversensing".
As described in the above-referenced application Ser. No. 759,902, many approaches to minimizing oversensing of the far field R-wave from the A-EGM have been attempted, including special electrode designs to minimize the magnitude of the far field R-wave and logic responding to coincidence of V-SENSE and A-SENSE events. At this point in the development of implantable dual chamber pacing systems, the IPG logic and timing circuit sets and times out an atrial sense amplifier blanking period (ABP) and atrial refractory period (ARP) in response to the detection of an A-SENSE event and the triggering of an atrial pace (A-PACE) pulse as well as a further post-ventricular atrial refractory period (PVARP) and blanking period upon a V-SENSE event and delivery of a V-PACE pulse. Similarly, the IPG logic and timing circuit sets and times out a ventricular sense amplifier blanking period (VBP) and refractory period (VRP) in response to the detection of at least a V-SENSE event and the triggering of an A-PACE or V-PACE pulse. The atrial and ventricular sense amplifiers and are effectively disconnected from the atrial and ventricular leads during the ABP and VBP/Respectfully, to protect the respective sense amplifier circuit from high signal levels. Any A-EGM signal passing through the atrial sense amplifier during the longer ARP or PVARP is considered to be noise and not used to reset the V-A escape interval and start the A-V delay interval. Instead, it may be interpreted as a noise artifact and used to actually prolong the refractory period. Similarly, any V-EGM signal passing through the ventricular sense amplifier during the longer VRP is considered to be noise and not used to reset the A-V delay interval and start the V-A escape interval.
P-wave "undersensing" can occur when ventricular depolarizations occur late in the intrinsic heart cycle at the time when an atrial depolarization is about to occur. The atrial and ventricular dissociation results in what is referred to as a "fusion beat". When the R-wave in the V-EGM is sensed, the ABP and PVARP are started, masking both the R-wave signal artifact and the P-wave signal at the input to the atrial sense.
In current IPGs, the blanking periods that are necessary to protect the sense amplifiers and the refractory periods that are used to provide noise detection and protection have minimum lengths that do not vary with pacing rate. Consequently, the use of such blanking and refractory periods can effectively blind the sense amplifiers during a substantial part of the cardiac cycle, particularly as the cardiac cycle shortens at high intrinsic atrial rates. While the cardiac cycle shortens, the delay until the far-field R-wave appears at the atrial electrodes and the width and amplitude of the far-field R-wave as observed at the atrial electrodes remains relatively constant, dictating constant ABP and PVARP intervals. Thus, the ABP and ARP intervals shorten the available time in the heart cycle for sensing legitimate P-waves.
Thus, far field R-wave oversensing is an old problem but gaining greater significance as the new features, e.g., mode switching, atrial arrhythmia monitoring, and tachyarrhythmia detection are implemented in advanced implantable cardiac stimulation devices. These new devices need to sense P-waves at high atrial rates, and low P-wave peak signal amplitudes. Hence, while it is desirable to be able to program a very short atrial refractory period with a high atrial sensitivity to detect such high rate P-waves in the A-EGM, doing so potentially causes oversensing of the signal peaks of far field R-waves. The inability to discriminate far field R-waves from P-waves in the A-EGM may inhibit atrial pacing, degrade A-V synchrony, falsely trigger mode switching, or prevent mode switching during atrial fibrillation.
In PCD systems and related ICD systems for treating atrial arrhythmias, accurate atrial arrhythmia detection is also made difficult by the combination of far field oversensing, undersensing and atrial and/or ventricular blanking and refractory periods. In proposed dual chamber PCD systems having the capability of detecting and treating atrial arrhythmias with at least a limited menu of anti-tachyarrhythmia therapies, also referred to as supraventricular arrhythmias and including atrial fibrillation and atrial flutter, the correct diagnosis of the nature of a detected tachyarrhythmia so that an appropriate treatment can be delivered is crucial. Typically, in proposed dual chamber PCD systems, at least both atrial and ventricular pacing and sensing functions are provided in conjunction with tachyarrhythmia detection and anti-tachyarrhythmia therapy delivery in at least one of the chambers. Such dual chamber PCD systems may only provide atrial anti-tachycardia pacing therapies or may include atrial cardioversion/defibrillation capabilities as further described below. The failure to deliver the appropriate therapy or the delivery of an inappropriate therapy to treat an apparent atrial tachyarrhythmia can progress to or trigger more serious ventricular tachyarrhythmia. Consequently, a great deal of effort has been undertaken to refine the diagnosis of the tachyarrhythmia and to define the appropriate therapy in response to the diagnosis. The accuracy of the diagnosis, particularly of an atrial arrhythmia, is highly dependent on the correct categorization of the sensed event as an R-wave or a P-wave.
The article "Automatic Tachycardia Recognition" by R. Arzbaecher et al., in the journal PACE, May-June 1984, pp. 541-547, discloses an algorithm intended to be implemented in a microprocessor-based implantable system employing both atrial and ventricular rate detection via separate bipolar leads in order to measure the intrinsic or evoked A--A and V-A, or V--V escape intervals and A-V delay intervals in order to distinguish among various types of atrial and ventricular tachycardias, fibrillation or flutter.
Other proposals for employing atrial and ventricular detection and interval comparison are set forth in The Third Decade Of Cardiac Pacing: Advances in Technology in Clinical Applications, Part III, Chapter 1, "Necessity of Signal Processing in Tachycardia Detection" by Furman et al. (edited by S. Barold and J. Mugica, Futura Publications, 1982, pages 265-274) and in U. S. Pat. No. 4,860,749 to Lehmann. In both cases, atrial and ventricular rates or intervals are compared to one another in order to distinguish sinus and pathological tachycardias.
In some of these proposed dual chamber PCD systems (and in existing single chamber PCD systems), one or two basic strategies are generally followed. A first strategy is to identify P-waves and R-waves and measure atrial and ventricular intervals and compare them to a preset group of criteria for differing arrhythmias which must be met as precedent to arrhythmia detection or classification. As events progress, the criteria for identifying the various arrhyhhmias are all monitored simultaneously, with the first set of criteria to be met resulting in detection and diagnosis of the arrhythmia. A second strategy is to define a set of criteria for events, event intervals and event rates which is generally indicative of a group of arrhythmias, and following those criteria being met, analyzing preceding or subsequent events to determine which specific arrhythmia is present. In the Medtronic Model 7219 devices, an arrhythmia detection and classification system generally as disclosed in U.S. Pat. No. 5,342,402, issued to Olson et al., incorporated herein by reference in its entirety, is employed, which uses both strategies together.
To reiterate, in both the dual chamber bradycardia pacing context and the atrial tachyarrhythmia detection context, the accurate detection of R-waves and P-waves is of great importance. The research conducted with HMM detection techniques described above has suggested that the HMM techniques may be valuable in discriminating P-waves from far field R-waves. However, the reported HMM techniques are computationally too demanding and take too much time to be employed in an implantable system where power conservation and size as well as speed are factors of great concern. There is therefore a need for a technique for speeding up HMM analysis of ECGs and providing real time HMM analysis of A-EGM signals while retaining the attributes of HMM detection of individual P-waves, R-waves and T-waves of the PQRST complex and discrimination of arrhythmias.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to make HMM techniques for detecting P-waves and R-waves more reliable and rapid by reducing computation complexity.
It is a still further object of the present invention to adapt HMM techniques to the automatic detection and discrimination of P-waves from R-waves in real time in implantable medical devices.
It is yet a further object of the present invention to adapt HMM techniques to the discrimination of P-waves from far field R-waves in the A-EGM in near real time in an IPG to facilitate detection of the atrial heart chamber rate to control functions of or the delivery of therapies by the IPG appropriate to the atrial heart rate.
These and other objects of the invention are realized in a wavelet transformation of groups or frames of the sample values of the ECG or EGM to derive a smaller number of W. T. coefficients that are employed as the observations in HMM processing for P-wave detection, R-wave detection, fusion beats, etc. and for arrhythmia analysis in a variety of applications. In our tests, only three to five W. T. coefficients are required to represent up to one hundred sample values of the ECG or EGM in each frame, and, consequently, the length of the W. T. coefficient observation sequence is much smaller than that of the original sample data. Since each frame represents a step in the modeling, the state sequence length is the same as the number of sample frames. Furthermore, since each frame is identified by a state, the total state number used to represent different waves is also much smaller. In other words, the wavelet HMM techniques of the present invention has far fewer observation states and a much shorter state sequence length that contribute to the computation speed-up in the HMM process.
In the context of an implantable pacing system of the types described above having separate atrial and ventricular sensing capabilities and far field R-waves appearing on the AP-EGM, the application of the wavelet HMM technique to the near real time detection of P-waves and far field R-waves in the A-EGM may be used for monitoring or diagnostic purposes. The number of computations and computation time during a heart cycle is reduced by timing the frames of A-EGM samples to the detection of A-SENSE events by the atrial sense amplifier. In this case, the A-EGM sample frame is defined in a window preceding and following each A-SENSE event. The A-EGM sample frames are wavelet transformed, and a number of selected W. T. coefficients for each sample frame are saved in a buffer. Each set of saved W. T. coefficients therefore represents either a P-wave or an intrinsic or paced far field R-wave (which may constitute a fusion beat) unless a noise situation occurs that continuously causes A-SENSE events to occur.
When the V-SENSE event occurs, an R-trigger is generated, and each set of saved W. T. coefficients is subjected to the HMM algorithm for a determination as to whether the preceding (and any concurrent) A-SENSE events from which the saved W. T. coefficients were derived are P-waves or R-waves. In addition, when the V-SENSE occurs, the HMM algorithm determines probaballistically whether or not the successive sets of saved W. T. coefficients represent P--P sequences, far field R--R sequences or P-R sequences or the like. In other words, the successive pairs of sets of saved W. T. coefficients are compared with an HMM for a P-R sequence to determine the closest match. The HMM model of the P-R sequence is derived in a training mode, and HMs of other sequences may also be employed in the process. Diagnostic data may be derived from the HMM model to confirm device operation, and entry into a diagnostic mode may be predicated on a sensed high atrial rate.
In the context of a PCD system or another system for diagnosing and treating atrial tachyarrhythmias, the same process may be followed to ascertain that successive A-SENSE events are actually caused by P-waves and not by oversensing of ventricular events.
Overall detection performance represented by sensitivity and positive predictivity of the two-state wavelet HMM model for either R-wave detection or rejection in atrium is very accurate and reliable. This high accuracy can be anticipated because the HMM model combines both signal morphology information and statistical information in data processing. The role of the wavelet transform used in the HMM analysis is twofold. First the use of wavelet transform significantly reduces the state number and state sequence length for the model, hence improves dramatically the computation efficiency. Second the wavelet transform can retain the basic morphology information of a wave by only a few coefficients. In addition, the use of a probability density fujnction in the HMM for an observation sequence tends to reduces the effect of noise and artifacts.
In a study conducted on a number of patients, only approximately 10 heart cycles of each patient were used for wavelet transform HMM training which is relatively quick and worked very well in the patients. The speed of wavelet HMM training is another advantage of the two-state HMM model and is important for implementation in implantable monitoring and therapeutic systems of the type described above.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, advantages and features of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, in which like reference numerals designate like parts throughout the figures thereof and wherein:
FIG. 1 is a set of tracings illustrating the conventional HMM technique for identifyg the PQRST activation sequence from sample values of the ECG;
FIG. 2 illustrates a two state HMM of the PQRST complex with stated probabilities for distinguishing P-waves from R-waves;
FIG. 3 is a set of tracings illustrating the wavelet HMM technique for identifying the PQRST activation sequence from sample values of the EGM;
FIG. 4 is a schematic illustration of an implantable dual chamber system for monitoring the A-EGM and V-EGM and, optionally providing stimulation therapies, wherein the wavelet HMM technique of the present invention may be implemented;
FIG. 5 is a schematic illustration of the architecture of a DSP operating in accordance with the operating algorithm of FIG. 6 and the training algorithm of FIG. 7 that may be incorporated into the present invention;
FIG. 6 is a flow chart illustrating the steps of performing the wavelet HMM technique with respect to an ECG or EGM in accordance with the preferred embodiment of the present invention; and
FIG. 7 is a flow chart illustrating the steps of wavelet HMM training usable in the flow chart of FIG. 6 and the architecture of FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
To substantially improve computation efficiency in using HMM techniques for detecting P-waves and R-waves and for arrhythmia detection and classification from the real time ECG or EGM (or for faster analysis of stored ECGs or EGMs), we developed a wavelet HMM technique as described in detail below to vastly reduce the number of computations required over the course of a heart cycle. Particular applications of the wavelet HMM technique for analyzing sets of wavelet transform (W. T.) coefficients associated with event detection follow the following general description of the invention.
As an application of the wavelet HMM H for real time R-wave detection in an EGM, we start with the sampled EGM data. Assume first that the sampled sequential EGM data has a sequence length of T and is represented by:
O=={o.sub.1,o.sub.2, . . . , o.sub.T }
where o i , is the ith EGM amplitude sample. Instead of using the sampled sequential data directly as an observation vector in the normal HMM technique, we group the sample data as:
O={{o.sub.1, o.sub.2, . . . , o.sub.m }, {o.sub.m+1, o.sub.m+2, . . . , o.sub.m+m }. . . , {o.sub.(n-1)m+1, o.sub.(n-1)m+2, . . . , o.sub.(n-1)m+m }}
where the multiplication of group number n and group size m equals T. Subsequently, a wavelet transform, such as a Daubechies wavelet or a Morlet wavelet transform of the types described by Daubechies, I. in "Orthonormal Bases of Compactly Supported Wavelets", Comm Pure and Appl. Math 1988; 41:909-996 and by Morlet D. et al., in "Wavelet Analysis of High-Resolution Signal-Averaged ECGs in Postinfarction Patients", J Electrocardiol 1993; 26:311-320, both incorporated herein by reference in their entireties, is applied to each group in the data. As is well known, the wavelet transform has been widely used in image compression and other signal processing fields. The advantage of a wavelet transform is so called multi-resolution representation, that is, fairly detailed information of the original data can be retained by much fewer coefficients in the wavelet transformed domain. The wavelet coefficient sequence is denoted as:
O.sub.w ={o.sub.w1, o.sub.w2, o.sub.w3, . . . , o.sub.wn }
with
o.sub.wj ={w.sub.j1, w.sub.j2, w.sub.j3, . . . , w.sub.jn }
where w jk the k th wavelet coefficient of the j th group. The new coefficient group size k is chosen to be much smaller than the original sample data group size m. The wavelet coefficients form the transformed observation sequence o w1 , o w2 , o w3 , . . . , o wn . The new observation sequence to be used in wavelet HMM has a length only 1/mth of the original observation sequence length T. Furthermore, since the original samples are grouped into frames, an HMM can be used to represent the state transitions between R-Wave (R), T-Wave (T), and P-Wave (P) states. There is a probability for a state to transit from one to any of the other states in a given patient that can be defined for a variety of cardiac rhythms. These probabilities for each rhythm are unknown a' priori, but can be estimated with an HMM training procedure in the manner taught in the above-referenced Rabiner reference.
The wavelet HMM is more computationally efficient than the conventional HMM processing. Assume a patient has a heart beat rate of 60 beats per minute and the sampling rate is 256 Hz. To detect waves in each beat of ECG data, the conventional HMM has 256 states and an observation sequence length of 256 observations. The computational complexity of HMM is proportional to N 2 T, where N is the number of states and T is the observation sequence length. For conventional HMMs, the computational complexity is 1.68×10 7 multiplications per second. For the wavelet HMM, we may group the sampling data into groups with size of m=32, define three states for the different waves (N w =3) and select two wavelet coefficients for each group of data (C w =2). An observation sequence length for each beat is now three (T w =3). In general, a discrete wavelet transform has a computational complexity proportional to km, where k is a constant (e.g., k=8 for the 4 tap Daubechies discrete wavelet transform). Thus, the wavelet transform computational complexity is proportional to kT w m. The wavelet HMM also requires a number of computations proportional to C w N w m. The total number of computations per second for the wavelet HMM is therefore kT w m+C w N w 2 T w , or 822 multiplications per second. When only two waves need to be discriminated (N w =2, T w =2), the number of computations per second required is only 528 per second. Thus, the difference between the normal HMM technique and the wavelet HMM technique of the present invention for analyzing the PQRST waves of a heart cycle is seen to be significant.
In this manner, the simplification in computation may be applied to the above-described prior art HMM processing techniques for analyzing the ECG or EGM data using a reference point to determine the beginning and end of each heart cycle in the sequences of heart cycles in the ECG or EGM subjected to processing. Once the reference point is determined, the sample values may be grouped about it as described above and the transitions between the defined states can be determined for a heart cycle. From the determined transition sequences, a diagnosis of a heart rhythm can be made.
FIG. 2 shows a two state model which has been used for far field R-wave detection and rejection in the A-EGM, and FIG. 3 shows waveforms accompanying steps of a preferred embodiment of the present invention wherein a reference point or marker for grouping frames of sample values is defined by a simple thresholding technique. In this simple model, two states, the P-wave (P) and R-wave (R) have been defined. Depending on the atrial rhythm, the probabilities for state transition between the two can be determined in a wavelet HMM training procedure for each patient. As an example, a 0.5 probability has been denoted in FIG. 2 for state transitions between P-waves and R-waves in a patient enjoying normal sinus rhythm. A third state could also be defined for the T-wave, if it is sought to be located, and different state models may be defined for various arrhythmias.
In tracing (a) of FIG. 3, in the first step of this illustration of one preferred embodiment of the present invention, the A-EGM is sampled at a sampling rate of 256 Hz or greater, and each sample value is compared to an atrial sense threshold set low enough to detect all possible waves of interest for the particular patient and determined in a patient work-up. For example, tracing (a) depicts an A-EGM exhibiting a series of P-waves each followed by a far field R-wave. both exceeding the atrial sense threshold. When a sample value exceeds the atrial sense threshold, an A-SENSE event is declared, and a group or frame of sample values is defined in step (b). The frame includes m samples in a window on either side of the sample value exceeding the threshold so as to capture most if not all sample values associated with the wave. The samples in each frame are wavelet transformed to obtain a set of representative W. T. coefficients (typically 2 to 4 W. T. coefficients) c1 and c2 as shown in tracing (c). The representative W. T. coefficient set is used as the observations for the wavelet HMM model to determine whether the A-SENSE event is more likely to be a P-wave or an R-wave. The detection result for each P-wave and R-wave is marked differently in tracing (d). The output of the detection identifies the time when the particular wave is detected, and which wave is detected. In a particular implementation of the invention described below, the P-wave and R-wave sequence of tracing (d) in the A-EGM is identified through a P/R wavelet HMM comparison that is initiated on detection of a V-SENSE event.
The representative W. T. coefficients may be selected in a variety of ways. For example, the coefficients with the greatest amplitudes may be selected or coefficients with specified indices may be selected.
FIG. 4 depicts an implantable; dual chamber, cardiac pacing or PCD system (in part) in which the present invention may be incorporated particularly for self diagnosis of oversensing or undersensing of A-SENSE events and in arrhythmia detection. The particular example depicted in FIG. 4 includes atrial and ventricular pacing pulse generators, but it will be understood that these components and pacing operations may be limited to one chamber in the pacemaker or PCD context or omitted entirely in a cardiac monitor context or in an ICD context not including pacing therapies. Thus, FIG. 4 is intended to comprehensively illustrate all such systems and not be limited to the DDD or DDDR pacing context per se.
In FIG. 4 the IPG 14 is coupled with atrial and ventricular leads 12 and 9 extending into the right atrium and ventricle, respectively, of the heart. The IPG 14 is provided with atrial and ventricular sense amplifiers 17 and 19, respectively, coupled through leads 12 and 9, respectively, to atrial electrode(s) 13 implanted in the atrium and ventricular electrode(s) 15 implanted in the ventricles, respectively, that are intended to sense P-waves and R-waves originating in the right atrium and ventricle, respectively. When the IPG 14 is provided with both atrial and ventricular sense amplifiers 17 and 19, it may be programmed or designed with an algorithm for operating in several pacing modes that generally involve using the sensed P-wave to time at least the delivery of a ventricular pacing (V-PACE) pulse by a ventricular pacing pulse generator 18 after an A-V delay unless an R-wave is sensed by the ventricular sense amplifier 19 before time-out of the A-V delay. In the DDDR pacing system depicted in FIG. 1, the IPG 14 is also provided with a logic and timing circuit 20 for setting and timing out the A-V delay and also setting and timing out a V-A escape interval starting on delivery of a ventricular pace pulse or sensing of an R-wave by ventricular sense amplifier 19. The V-A escape interval is itself terminated either by a P-wave sensed by atrial sense amplifier 17 before it times out or delivery of an atrial pacing (A-PACE) pulse by the atrial pacing pulse generator 16 on time-out.
The logic and timing circuit 20 establishes a V-V rate governing the setting of the V-A escape interval that may itself vary depending on a physiologic signal derived from a physiologic sensor, e.g. a patient activity sensor 21, in a manner well known in the art. To the extent that the intrinsic atrial heart rate exceeds the current V-V rate, the recurring P-waves are sensed and control the synchronous pacing rate up to an upper pacing rate limit.
The well known DDD and DDDR pacing mode encompasses atrial and ventricular pacing and sensing and operation in either a synchronous or an inhibited manner depending on the prevailing atrial and ventricular heart rhythm. The related VDD pacing mode provides atrial synchronous, ventricular inhibited pacing, i.e., the DDD pacing mode as described above, but without the atrial pacing capability. In both the DDD and VDD pacing modes, the ability to sense P-waves and distinguish them from R-waves is crucial to avoid inappropriate resetting of V-A escape intervals and/or triggering of synchronous ventricular pacing.
Typically, the input A-EGM is sensed from a unipolar or bipolar, atrial lead 12 having one or two pace/sense electrodes 13 in contact with the atrium, and the input V-EGM is sensed from a unipolar or bipolar ventricular lead 9 having one or two pace/sense electrodes 15 in contact with the ventricle. As described above, the typical atrial and ventricular sense amplifiers 17 and 19 employ sense criteria for distinguishing valid P-waves and R-waves, respectively, from electrical noise and artifacts. The input A-EGM and V-EGM signals are filtered to attenuate commonly encountered electrical noise and muscle artifacts and the amplitudes of the signals are compared against A-SENSE and V-SENSE thresholds. When the amplified and filtered A-EGM and V-EGM signal amplitudes exceed the A-SENSE and V-SENSE thresholds, the A-SENSE and V-SENSE event signals are generated. The typical sense amplifiers 17 and 19 in prior art DDD and DDDR pacemakers provide the A-SENSE and V-SENSE event signals to control timing and may also store real time segments of the amplified and filtered A-EGM and V-EGM signal samples, after ADC conversion, for diagnostic purposes.
In accordance with a preferred embodiment of the present invention, the amplified and filtered A-EGM and V-EGM signals are further processed within timing and control circuit 20 as described below in reference to the block diagram of FIG. 5 and flow charts of FIGS. 6 and 7 in a diagnostic operation to determine if successive A-SENSE events in the A-EGM are true P-waves or far field R-waves or represent a fusion beat of a P-wave hidden in a far field R-wave. In this preferred embodiment, the detection of A-SENSE and V-SENSE events is employed in normal sensing operations, and the diagnostic routine may be entered when the sensed atrial rate is excessive, for example. In the latter case, the A-SENSE and V-SENSE events are not employed per se, but could be employed as the P/R trigger and R-trigger signals. The system and process described below may also be implemented in other implantable and external EGM or ECG signal processing systems.
In FIG. 5 the A-EGM and V-EGM analog input signals are filtered and amplified in amplifier stages 30 and 32, respectively, which may be the initial input stages following the blanking stages of atrial and ventricular sense amplifiers 17 and 19 of FIG. 4. The amplified signals are digitized by ADC 34 at a sampling frequency of at least 256 Hz established by sampling clock 36. The digitized A-EGM samples A(n) and V-EGM samples V(n) are sampled at the same time t(n), and the time stamp of each sample is registered with the sample value and employed in the remaining processing blocks of FIG. 5 and steps of the operating and training algorithms. The digitized A-EGM samples A(n) are digitally filtered in digital filter 38, and the digitized V-EGM samples V(n) are digitally filtered in digital filter 40 to remove any baseline drift in the sample values.
In the preferred implementation in DSP, the following operations of the block diagram of FIG. 5 are performed by an algorithm that is programmed in conforming with the operating algorithm flow chart of FIG. 6 and the training algorithm flow chart of FIG. 7. The blocks of FIG. 5 illustrate the architecture and operations of the operating and training algorithms and are simplified to clarify the explanation of this embodiment of the invention.
The filtered ventricular samples V(n) are applied to an R-Trigger threshold comparison block 42, and compared against a programmed R-threshold digital value. When the sample V(n) is greater than the R-threshold value, an R-Trigger is generated within R-Trigger threshold comparator block 42 as long as the state Q V of a digital blanking timer B V within R-Trigger threshold comparator is not high (Q V =1). It is assumed that a number of the ventricular samples V(n) will exceed the R-threshold digital value, and it is desired that only a single R-Trigger will be generated when the first ventricular sample V(n) exceeds the R-Trigger threshold.
Assuming that Q V =0, and that an R-Trigger is generated in response to a sample V(n) at the time t(n) associated with it, then Q V is set to 1, and the time t(n) is registered as the starting time t V of the digital ventricular blanking period B V . The results of the comparison of each subsequent ventricular sample V(n) to the R-Trigger is not allowed to generate a further R-Trigger by operation of the digital blanking timer. The digital blanking timer state Q V may be reset to 0 by lapse of time or by the count of a number of succeeding ventricular samples in a manner well known in the art. In any case, the initial R-Trigger is a pulse associated with a time t(n) of the ventricular sample V(n) and is applied to the HMM operating block 50 or to the training logic block 52. The HMM block 50 responds by restarting an HMM analysis on the W. T. coefficient sequence buffered during the previous cardiac cycle to determine its state sequence based on the HMM statistics 64 and the Viterbi algorithm in a manner disclosed, for example, in the above-referenced Rabiner reference.
The digitized atrial samples A(n) are applied in parallel paths to DT1 and DT2 delay blocks 56 and 58 that delay the samples A(n) before applying them to a P/R-Trigger threshold block 60 and to a FIFO buffer in W. T. block 62. The delay DT2 is provided to delay the sample A(n) in order to compensate for a relatively lower P/R-threshold employed in the P/R-Trigger block 60 than the R-Trigger threshold employed in the R-Trigger block 42 which somewhat, unintentionally, offsets the delay that it takes for the far field R-wave to reach the atrial sense electrode(s). In other words, DT2 may be needed because the difference in thresholds can result in triggering the generation of the P/R-Trigger in response to an A(n) sample due to a far field R-wave in the A-EGM that is earlier in time than the V(n) sample that triggers an R-Trigger. It is desired to ensure that the R-Trigger occurs earlier than the P/R-Trigger for the same R-wave in order to commence the new processing cycle in the HMM processing block 50.
After the delay DT1, the atrial sample A(n) is applied to the P/R-Trigger block 60, and it operates to generate a P/R-Trigger by comparison of the sample to a programmed P/R-Threshold and as long as the state Q A of a digital blanking timer B A within P/R-Trigger block 60 is not high (Q V =1). P/R-Trigger block 60 operates in the same manner as the R-Trigger block 42 described above with respect to the comparison and digital blanking operations. The DT1 delay block 58 is provided in conjunction with the length of an atrial sense (AS) buffer within the W. T. processing block 62 that retains a number preferably twice the number m of A(n) samples on a FIFO basis from which the frame length T W or number m of samples to be grouped and subjected to the W. T. operation when the P/R-Trigger is generated. In FIG. 4, the P/R-Trigger is generated in block 60 when the digital atrial sense threshold is exceeded (assuming that the digital ventricular blanking period B V has timed out), and the W. T. operation is then conducted on the frame with m of A(n) samples in the AS buffer. The P/R-Trigger also supplies a time stamp to the triggered W. T. operation.
Referring back to FIG. 3, tracing (c), the framed A(n) samples for the P-waves and far field R-waves are already temporarily stored within the AS buffer when the peak detection of the P-wave and far field R-wave occurs in tracing (a) of FIG. 3 by setting the delay DT1 so that it exceeds the delay DT2 by an amount that ensures that the full frame length T W of A(n) samples are in the AS buffer when the P/R-TRIGGER is generated. Of course, the triggering of the W. T. operation by P/R-trigger could itself be delayed by a time sufficient to ensure that a full frame of A(n) samples roughly centered on the actual A(n) event exceeding the atrial sense threshold is then stored in the AS buffer.
As described above, the W. T. operation performed in W. T. block 62 on each frame m results in a smaller set of W. T. coefficients C W that are to be used in the HMM operation in HMM block 50. The coefficients C W and the P/R-Trigger time stamp are maintained in registers of a coefficient buffer within HMM block 50 until the occurrence of an R-Trigger generated by R-Trigger block 42. The R-Trigger is taken to represent a true R-wave and the end point of the heart cycle and the start of a new heart cycle. On this reference point, the HMM Viterbi algorithm is invoked to make a determination as to the probable sequence represented by the preceding sets of number C W of coefficients in the coefficient buffer since the last R-Trigger. In that analysis, the sets are used as the observations in the manner described in the above-referenced Coast et al. articles, for example, for HMM processing against stored coefficient sets maintained in training memory 64 that are derived in a training operation based on the patient's own A-EGM characteristics as described below. The models developed in the HMM training include the left to right sequence for normal sinus rhythm depicted in the lower tracing of FIG. 1 as well as left to right sequences for a variety of arrhythmias. Then, based on the probabilistic determination of the sequence that is made in the HMM processing, P-wave and/or R-wave markers are generated that reflect normal sinus rhythm or an arrhythmia.
Turning to FIG. 6, it depicts a flow chart of the operating algorithm paralleling the above described functional description of FIG. 5. Preliminary steps S100, S102 and S104 are conducted at least initially when the implantable or external system is implanted or attached to the patient and then may be repeated periodically by the physician monitoring performance of the system. In step S100, algorithm parameters are initialized and stored in memory to be called up and employed in the appropriate operating architecture blocks of FIG. 4, including the following:
N--Number of states defined in each HMM;
T W --Time window or length of W. T. frame of A(n) samples;
C W --The selected W. T. coefficients used to represent each wave in each HMM (assuming more than one HMM);
B A --Atrial channel digital blanking period having state Q A ;
B V --Ventricular channel digital blanking period having state Q V ;
T A --P/R-Trigger threshold;
T V --R-Trigger threshold;
DT1--AS buffer delay;
DT2--A(n) threshold compensating delay
In steps S102 and S104, the initial training of the state transition probability matrix is performed pursuant to the training algorithm described below in reference to FIG. 7, and the results are stored in memory to be called up and used in the HMM operations performed in step S128. These include the state transition probability matrices for normal sinus rhythm states and any arrhythmia states as well as the statistics of averaged W. T. coefficient vectors for each defined wave (state).
In step S104, the analysis is started and a number of parallel operations are commenced because of the parallel processing of the A(n) and V(n) samples derived from the A-EGM and V-EGM as depicted in FIG. 5. Starting for convenience with the A(n) sample processing, the next A(n) sample is obtained in step S108 and delayed by DT1 in step S110 and DT2 in step S109. Since DT1>DT2, the delayed A(n) sample is first stored in the AS buffer in step S116. Delay DT1 is related to the sampling frequency and the time window T W to ensure that m A(n) sample values are stored in the AS buffer before the delayed A(n) sample is compared to the P/R threshold T A in step S112.
Assuming that the state Q A of the atrial digital blanking state Q A is low or 0, then the P/R-Trigger is generated in step S114. At the same time, in step S114, the state Q A is set high or 1, and the atrial blanking time period start time stamp t A is set to the time stamp of the triggering A(n) sample. Thereafter, as long as state Q A =1, the conditions of step S112 cannot be satisfied by subsequent A(n) events. The digital atrial blanking period B A is timed out in step S113 by subtracting the saved time stamp t A from the time current stamp t of each subsequent atrial sample A(n) and comparing the result to the digital blanking time B A . When t-t A >B A , then state Q A is set to 0 in step S115
Referring back to step S114, the P/R-Trigger causes a frame of A(n) samples stored in the AS buffer corresponding to the W. T. time window T W to be wavelet transformed and the resulting number C W of W. T. coefficients to be temporarily stored in a coefficient buffer in step S118. The P/R-Trigger is also reset in step S118.
At the same time, the next ventricular sample V(n) in step S120 is compared to the ventricular digital threshold T V in step S122. If the ventricular sample V(n) exceeds the digital threshold T V , and if the ventricular refractory timer state Q V is at 0, then the R-Trigger and the state Q V are both set to 1 in step S124. The digital ventricular blanking period B V is timed out in steps S123 and S125 in the same manner as the atrial blanking period B A is timed out in steps S113 and S115 described above.
When the R-Trigger is set to 1, the condition of step S126 is satisfied, the HMM Viterbi algorithm is performed on the observation sequence formed of the sets of W. T. coefficients stored in the coefficient register in step S118 using the stored P, R Wave statistics stored in memory in step S104. The R-Trigger is set back to 0 in step S128 and the P-wave and R-wave Markers are outputted in the determined sequence in step S128. When each such Marker is outputted, it is accompanied by a time stamp that subtracts out the delay DT1. The cycle is restarted in step S106.
In the context of the IPG 14 of FIG. 4, the P-wave and/or R-wave markers in the sequence of the immediately concluded heart cycle can be stored in memory for telemetry out in response to a programmed in interrogation command and/or used in a diagnostic routine to confirm that preceding A-SENSE events are truly in response to an intrinsic P-wave and not due to a far field R-wave or noise spikes.
In a dual chamber pacing context, a routine may be entered for determining appropriate ventricular refractory periods or for setting the ventricular sense threshold of the ventricular sense amplifier or for setting an appropriate minimum V-PACE pulse energy level to ensure ventricular capture in manners well known in the art. The same routines may be entered to set atrial sense threshold, atrial refractory period and A-PACE sense thresholds. In the case of a dual chamber pacemaker operating in a rate response mode, the pacing escape interval set in response the physiologic sensor may also be varied to test for an underlying heart rhythm, and differing factors may be tested for establishing the rate response to the sensor output signal. A variety of other diagnostic tests may be undertaken to optimize performance of the pacing or sensing operating algorithms. In each case, the HMM analysis is conducted retrospectively only one heart cycle after the real time occurrences of atrial events, and consequently is in near real time to those events.
In the case of a system for determining whether an arrhythmia exists in either chamber, the HMM analysis can be conducted in the same beat to beat time frame that typical rate, onset and stability arrhythmia determination algorithms rely upon. Consequently, the arrhythmia determinations employing the improved HMM techniques of the present invention may be conducted alone or in parallel with the classic atrial and ventricular arrhythmia determination algorithms.
The training algorithm is invoked in FIG. 5 by a training command received from logic and timing block 20, and a flag indicating completion of the training is provided to logic and timing block 20. Training may be invoked by a programmed in command or when the wavelet HMM algorithm is turned on by a programmed in command. The results of the training are maintained in the memory 64 of FIG. 5. In order to derive the HMM model for each wave of interest and sequence of waves of interest, it is necessary proceed with the training routine. The training routine may be repeated from time to time or upon occurrence of an event, e.g. a change in activity level of the patient, which may be monitored by an activity sensor. For example, when training is initiated, a number, e.g. 10 heart cycles, may be monitored for model training. For each non-fused P-wave identified in the 10 heart cycles, 32 data samples (128 ms) centered at the P-wave peak were stored and wavelet transformed using the four tap Daubechies wavelet transform, for example. After applying the wavelet transform, two wavelet coefficients are selected and used as an observation for the selected P-wave. Each of two coefficients are averaged individually over all P-waves identified for training to obtain a mean and a standard deviation. The mean and standard deviation are used in P-wave observation probability density function in the model. The P-wave observation probability density function is a sum of two univariate Gaussian functions. The identical training procedure is also used for deriving mean and standard deviation coefficients representative of a far field R-wave for each patient.
In experimental verification of this approach, the detection results were saved and verified by visual examination of the atrial electrogram. The true P-wave and far field R-wave locations in the atrial electrogram were manually identified and marked for each patient. These manual markers were used as the control for comparison with the analysis by the HMM model.
In FIG. 7, a training initialization is commenced in step S200 for all of the above listed parameters set in step S100. The parameter values initialized in step S200 are entered by the physician employing an external programmer in a patient work up following a regimen for programming in test values of each parameter, observing results and arriving at optimum values in a manner known in the art. The training algorithm of FIG. 7 then follows the architecture of FIG. 5 and employs many of the same steps as the operating algorithm of FIG. 6. These same steps are numbered in the same order as those appearing in FIG. 6 and described above. Steps S208-S216 and S220-S225 correspond to steps S108-S116 and S120-S125, respectively. The remaining steps differ. One difference is that time stamps t AP and t VP are maintained for the atrial and ventricular samples A(n) and V(n), respectively, that previously exceeded the digital P/R-Trigger threshold and the R-Trigger threshold and ventricular precede the time stamps t A and t V , respectively. Separate counters J and K are initially set to 0 and used to count the number of non-overlapping P-waves and far field R-waves to a maximum count 10 in order to obtain meaningful mean and standard deviation values. A buffer D K is used to store the W. T. coefficients of far field R-waves.
In step S226, when the P/R-Trigger=1 and the counter J count is less than 10, the current P/R-Trigger time stamp t A is far distant in time from both the previous R-trigger time stamp t VP and the current R-trigger time stamp t V , and therefore can be assumed to result from a true P-wave and not a far field R-wave. In other words, if J<10, t V -t A >1.5 T W , and t A -t VP >1.5 T W , these conditions signify that the current signal is a P-wave, because the time stamp t A is mid-way between two R-wave time stamps t V and t VP . Then, the W. T. operation on the frame m (i.e., T W ) A(n) samples in the AS buffer centered at t A is conducted in step S228. The wavelet coefficient vector C J is saved and the J counter count is incremented by 1 in step S228. The P/R-Trigger is set to 0 in step S228.
If, the conditions of step S226 are not met at the P/R-Trigger=1 in step S214. or if the operations of step S228 are completed, the conditions at step S229 are examined. When R-Trigger=1 and the counter K count is less than 10, and if the R-trigger is at a reasonable distance in time from the previous P/R-Trigger, it is assumed that there is no P-wave at this time. Then T W <t V -t AP <2 T W which means that the current wave time stamp is distant from the previous atrial wave time stamp t AP , but not far distant, and it is most likely a non-overlapping far field R-wave. If all of these conditions are not met, the training is continued to the next atrial sample A(n) is awaited in step S208. If all the conditions are met, then step S230 is commenced.
In step S230, the W. T. operation is commenced on the contents of the AS buffer centered at the time t V to derive a non-overlapped far field R-wave set of W. T. coefficients. The W. T. coefficients are stored in buffer D K , the counter K count is incremented by 1, and the R-Trigger is set to 0 in step S230. Next, the counts of R-wave capture counter K and P-wave capture counter J are examined in step S232 to determine whether the training should be completed. If both counts are equal to or greater than 10, then the HMM statistics based on the C J and D K sets of coefficients. The training algorithm is completed in step S236, and the Training Complete signal is provided to the logic and timing block 20 in FIG. 4 or to an equivalent system in an external embodiment. The training algorithm is automatic once the initial parameters are entered in step S200 and is completed in a short number of cardiac cycles. It may be re-entered from time to time to update the W. T. coefficients.
The present invention may be employed in a variety of cardiac monitoring and therapy providing systems as stated at the outset. In one variation, the signal processing method and apparatus as described above with respect to FIGS. 5 and 6 may be substituted for the atrial and ventricular sense amplifier comparator stages typically incorporated into hybrid circuit sense amplifiers such that the resulting P-Marker and R-Marker signals are used instead of A-SENSE and V-SENSE event signals. In a hybrid combination, the atrial channel A-EGM processing may be conducted using the algorithm of the present invention, but the traditional ventricular channel V-EGM sense amplifier may be used to generate a V-SENSE event signal that is used as the R-Trigger signal applied to the HMM analyzer 50.
The resulting R-Marker and P-Marker signals may be used to trigger or inhibit pacing operations in a dual chamber pacing mode or used in any of the known tachyarrhythmia detection algorithms referred to above to quickly determine whether or not an atrial or a ventricular tachyarrhythmia is present.
The present invention is described above in the context of a multi-programmable, microcomputer based logic and timing circuit 20 with the filtering, timing, comparison, adaptive filtering and morphological functions conducted under the control of algorithms stored in memory. However, the present invention may also be usefully practiced in all such configurations by means of a full custom integrated circuit in each case. For example, such a circuit may take the form of a state machine in which a state counter serves to control an arithmetic logic unit to perform calculations according to a prescribed sequence of counter controlled steps.
In the above-described preferred embodiment, only a two-state HMM was specifically described. In general, a multi-state HMM can be developed for more complicated beats classification or arrhythmia detection. For example, in some patients exhibiting atrial flutter with multiplesre-entries or atrial fibrillation, P-waves in the A-EGM could possess different morphologies. In such a case, different P-waves can be defined as different states in an HMM model so that all possible P-waves may be discriminated from one another and from far field R-waves. It should also be noted that when pacing stimulation exists, and/or patients are in exercise, the morphology of P-waves and far field R-waves in the A-EGM will be altered. To discriminate both paced and intrinsic far field R-waves, an HMM model with three or more states may be necessary.
The reliable detection or rejection of far field R-waves in the A-EGM would avoid problems of atrial undersensing or oversensing, thus benefiting patients with more reliable and better atrial arrhythmia detection. In addition, detection of far field R-waves could be a measure for auto-capture in the ventricle and allow discrimination of supra-ventricular tachyarrhythmia from ventricular tachyarrhythmia.
While there has been shown what are considered to be the preferred embodiments of the invention, it will be manifest that many changes and modifications may be made therein without departing from the essential spirit of the invention. It is intended, therefore, in the following claims to cover all such changes and modifications as may fall within the true scope of the invention.
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This is a method and apparatus for the automated discrimination of cardiac events of interest, including P-waves, R-waves, T-waves and specific arrhythmic sequences, in EGM signals for data storage in an implantable monitor or to control operations of an implantable cardiac stimulator through the use of Hidden Markov Modeling techniques and a reduced set of observations.
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BACKGROUND OF THE INVENTION
The invention relates to a method of making MMC components by an infiltration process, with the preform which is disposed inside a crucible and, optionally, held by a preform holder, being placed inside a pressure container, wherein the atmosphere inside the pressure container is changeable during the manufacturing process.
Composite materials can be infiltrated with molten metal by applying gas under pressure to thereby produce so called metal matrix composites (MMC) are formed. Prior to such an infiltration process, the metal must be heated above its melting point so as to be able to permeate into the preform of the composite material. At the temperatures generated herein, the oxygen in the surrounding air, however, reacts with the metal surface, forming oxides which are detrimental to the properties of the formed component. In addition, the preforms themselves can react with the oxygen in the air. As a result, substances, like oxides, oxynitrides, oxycarbides, or the like are formed in dependence on the composition of the preform. These substances which are formed mainly on the surface of the preform, may adversely affect the open porosity which is required for the infiltration process to work. Consequently, as a result of the growth of these oxide compounds, the diameter of the pores may decrease to such extent that the pressure created by gas is no longer sufficient to overcome the capillary forces acting on the liquid infiltration metal, so that the infiltration metal can no longer migrate into the preform. In the worst case scenario, the aforedescribed oxidation processes may even completely seal the open pores.
The reaction between preform material and air alters thus in addition the material properties of the preform, thereby effecting an unintentional alteration of the physical and thermal properties, on the one hand, and complicating or eliminating the reproducibility of the desired material properties of the composite.
In order to eliminate this drawback, there is the possibility to evacuate the preform before the infiltration metal is melted on, to thereby expel the oxygen from the pores.
In another known process, the air (and thus the oxygen) is expelled from the preform by an inert gas purge. This process, however, is rather unreliable and time-consuming since it takes a long time until the oxygen molecules are adequately purged from the pores of the preform or of the preform holder.
In summary, both these processes are complex and time-consuming.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a process of the aforementioned type for making MMC components which effectively prevents the negative impact of oxygen and which is easily carried out.
This object is realized in accordance with the invention by keeping the preform in a sealed atmosphere in the presence of an oxygen-binding material after the infiltration metal has been melted on.
As a consequence, the oxygen inside the sealed atmosphere, i.e. within the pores of the preform, in the cavities between the preform and preform holder, etc., is bound and its harmful effect is thus avoided.
In a preferred embodiment of the invention, the oxygen-binding material can be formed from materials such as e.g. graphite, carbon, or the like, and/or from metals such as e.g. zirconium, titanium, or the like.
Above a temperature of about 600° C., an intensive redox reaction develops in the presence of these materials whereby the oxygen within the sealed atmosphere is bound.
In this context, it may be particularly advantageous to utilize a porous oxygen-binding material exhibiting pores filled with H 2 .
Apart from the reduction of oxygen, hydrogen is released at the same time, thereby enriching the sealed atmosphere with an inert gas.
According to another embodiment of the invention, it may be provided to form the oxygen-binding material as preform holder and, optionally, in addition, as a separate piece work upon the infiltration metal, and/or as a sheath surrounding a crucible.
An additional component can be eliminated if the preform holder itself is made from oxygen-binding material.
In accordance with another feature of the invention, the infiltration metal can be made from metals, such as e.g. aluminum, copper, magnesium, silicon, iron, titanium, or the like, or alloys thereof.
These metals are especially well adapted for the manufacture of MMC components.
According to a modification of the invention, the oxygen-binding material is only provided in certain regions.
Thus, sections of the workpieces can be made with different properties in a simple manner.
BRIEF DESCRIPTION OF THE DRAWING
The process according to the invention is discussed in greater detail with reference to the accompanying drawing, in which:
FIG. 1a is a vertical section of an apparatus for carrying out the process according to the invention;
FIG. 1b is a vertical section of an alternate embodiment of the apparatus according to FIG. 1a;
FIG. 2a is another embodiment of the apparatus according to FIG. 1a;
FIG. 2b is an alternative embodiment of the apparatus according to FIG. 2a;
FIGS. 3a, b are a perspective view and a vertical section of a MMC component, with metal components being cast therein.
FIG. 4a is a vertical section of still another variation of the apparatus according to FIG. 1a; and
FIG. 4b is a vertical section of still another variation of the apparatus according to FIG. 1b.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1a shows a pressure container 1 for making the MMC formed bodies. Disposed inside the pressure container 1 is a preform holder 2 for receiving the preform 3. The preform 3 is comprised of a reinforcing material which is arranged in a desired fashion. The entire arrangement is housed inside a crucible 6. The pressure container 1 can be sealed with a lid 7 to pressurize the container 1 from a pressure source 10.
A block or feeder 4 of infiltration metal is disposed on the rim of the preform holder 2. A heater 5 causes the metal to melt on. As soon as being liquefied, the metal completely covers the preform 3 as well as the preform holder 2 and bears upon the inner wall surface of the crucible 6. Thus, the preform 3 and the preform holder 2 are sealed off from the atmosphere prevalent inside the pressure container 1. This is required to press the liquid metal into the preform 3 through increase of the gas pressure inside the pressure container 1. In the event, a path would exist for permitting a penetration of gas between the interior space of the pressure container and the preform 3, a gas pressure increase within the pressure container 1 would result in an equal increase of the gas pressure inside the pores, thereby rendering an infiltration impossible.
After infiltration has concluded, the heater 5 is turned off and the metal is left to solidify under pressure.
The preform holder 2 is not a requirement, since the preform 3 may be positioned directly inside the crucible 6 as shown in FIG. 4a.
FIG. 1b shows an alternate embodiment of the apparatus of FIG. 1a, with the heater being omitted. Here, the metal 11 which was melted at a different location, covers the preform 3; the lid 7 is closed, the inside of the pressure container 1 is pressurized by means of the pressure source 10, thereby pressing the liquid metal into the preform 3, and the metal is left to solidify.
FIG. 2a represents a detail within the pressure container 1 of FIG. 1 in a different embodiment. Equivalent parts are given the same reference numbers.
A preform 3 is again positioned in a preform holder 2. A cover 8 with bores 9 rests on the preform holder 2, with the feeder 4 resting on the cover 8. The crucible 6 surrounds the preform holder 2 with its inserts and its caps. Through action of the heater 5; the infiltration metal melts, migrates through the bores 9 to the preform 3, and infiltrates the reinforcing material under applied pressure at closed lid 7.
Here again, it is important that the preform 3, preform holder 2 and cover 8 are sealed gastight by the liquid infiltration metal 4 from the surrounding atmosphere.
FIG. 2b shows an alternate embodiment of FIG. 2a, whereby the heater has been omitted. Here, the metal 11 melted at a different location outside the pressure container 1 covers the cover 8; again, after the lid 7 is closed, the metal is pressed into the preform under pressure application by means of the pressure source 10 and left to solidify.
At the temperatures at which the infiltration metal 4 melts, the oxygen in the atmosphere inside the pressure container 1 reacts with the infiltration metal 4 and forms compounds which impair the properties of the component to be made.
The process according to the invention targets to maintain at least the preform 3 or--as in the embodiments shown in the Figures--the entire content of the crucible 6--i.e. the preform 3 and the preform holder 2--in a sealed atmosphere. Provided within the sealed atmosphere is an oxygen-binding material which at elevated temperatures--about 600° C. when using graphite--reacts with and binds the oxygen which is present within the sealed atmosphere, i.e. inside the pores of the preform 3, in the hollows between the preform 3 and the preform holder 2, etc. Thus, in accordance with the present invention, molten infiltration metal of any kind so covers the preform (and preform holder, when included in process) as to enclose the preform (and preform holder, when included in process) and the oxygen-binding material in a sealed atmosphere.
It is possible to wait for a certain period while keeping the temperature and the pressure constant between the time when the metal melts, i.e. the time when the crucible is hermetically sealed off, and the introduction of the overpressure in the container. On one hand, this ensures a uniform and complete heating of preform 3, preform holder 2, and infiltration metal 4; and, on the other hand, the reaction between graphite and oxygen can proceed long enough to sufficiently reduce the oxygen content.
Consequently, the oxygen can no longer exhibit the afore-stated detrimental effect; the formation of parasitic oxygen compounds in the infiltration metal 4 and in the preform 3 is thus prevented.
The oxygen-binding material is either formed as the preform holder 2 itself, or possibly as an additional form piece 20 which is positioned above the infiltration metal 4 (FIG. 1a and 2a), or as a sheath 21 (FIG. 1b) surrounding the crucible 6. If no preform holder 2 is provided and if the preform 3 is placed directly inside crucible 6, then the inner wall of crucible 6 may be coated with oxygen-binding material in order to attain the same reducing action as with preform holder 2. This variation is shown in FIG. 4b. In this case, however, the gas permeability of the oxygen-binding material should be taken into account. As described above, the liquid infiltration metal 4, has to seal the preform 3 together with the oxygen-binding coating against the atmosphere in the pressure container. Should a porous coating extends through the surface of the liquid metal, then the seal of preform 3 would no longer be gastight.
The sheath 21 and the form piece 20 are not a requirement since both merely bind oxygen from the atmosphere in the pressure container. The arrangement of sheath 21 and form piece 20, however, is advantageous since a certain quantity of oxygen is already bound during the heat-up phase, while the infiltration metal 4 has not yet become liquid and has not yet sealed the preform 3 in a gastight manner from the atmosphere in the pressure container. After concluded sealing of the preform 3 from the surrounding atmosphere by the infiltration metal 4, the oxygen content in the pores of preform 3 is already diminished so that the remaining oxygen can be bound more rapidly and more completely.
The atmosphere in the pressure container 1 is formed preferably of ambient air; however, according to the invention, the atmosphere may also be formed by an inert gas or by an atmosphere at reduced pressure. In all situations, however, according to the invention, a sealed atmosphere is formed within crucible 6, with oxygen-binding materials binding the parasitic oxygen in this atmosphere.
The oxygen-binding materials may be made from graphite, carbon, or the like, but any other-oxygen-binding material can be employed. For example, certain metals with a high affinity for oxygen may be utilized. Examples herefor are zirconium, titanium, or the like.
It is especially advantageous to employ an oxygen-binding material which is porous--preferably titanium--and to fill its pores with H 2 before placement of the material inside the crucible 6. Such a material has during heating the effect of binding oxygen, while at the same time releasing the inert hydrogen. Such a material may be employed in addition to a preform holder 2 made from an oxygen-binding material, by e.g. incorporating a recess in the preform 2 for placement and a porous material placed into said recess.
The infiltration metal 4 may, depending on the properties required of the MMC component, be formed of metals, such as e.g. aluminum, copper, magnesium, silicon, iron, titanium, or the like, or alloys thereof. This list contains only some examples and any other suitable metal can be employed for carrying out the process according to the invention.
For certain MMC components, it is desirable that specific regions of the infiltration metal 4 are oxidized. According to the invention, such components may be made by arranging oxygen-binding material only in certain sections. For example, only one third of the surface of the infiltration metal 4 is covered with an oxygen-binding form piece 20 so that the oxidation processes can take place in the uncovered region of the infiltration metal 4, whereas oxidation processes in the covered region are averted.
An example for the necessity to provide an application for the aforedescribed local reducing action is subsequently described. Kovar, nickel-iron alloys, molybdenum, copper, etc., and alloys thereof tend to oxidize when heated in an oxygen-rich atmosphere. An oxide layer will form on the surface and components formed from these materials can be joined to other components only with difficulty or not at all. If components made from such materials should also be cast during the infiltration process, it is thus necessary to protect at least these components from oxidation through local arrangement of oxygen-binding material.
An actual exemplified application is shown in FIGS. 3a, b. Here, a housing which is open at the top, is to be made as MMC component. This is accomplished by placing a frame 31 made of Kovar on a preform plate 34. This frame 31 is provided with openings 32 through which openings 32 pins 30 made of Kovar are passed through to form electrical connections. Ceramic sleeves 33 are placed in the openings 32 for isolating the Kovar pins 30 from the frame 31. Since Kovar, as stated above, tends to oxidize during the heat-up phase which precedes the infiltration process, the Kovar components are protected from the effects caused by oxygen through near-by arrangement of oxygen-binding materials 35, 36. In the example of FIGS. 3a, b the oxygen-binding materials are formed, on the one hand, as plates 35 and, on the other hand, as strips which hold the pins 30 during the infiltration process, with the oxygen-binding materials 35, 36 being made from any oxygen-binding material such as e.g. graphite, carbon, or the like.
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Method of making MMC components by an infiltration process, with a preform (3) which is disposed inside a crucible (6) and, optionally, held by a preform holder (2), being placed inside a pressure container (1), wherein the atmosphere inside the pressure container (1) is changeable during the production process, and after the infiltration metal (4) has melted on, the preform (3) is contained inside a sealed atmosphere in the presence of an oxygen-binding material.
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BACKGROUND OF THE INVENTION
This invention relates to a method for obtaining in large volume a gas stream that is 90%-99% and higher by volume in one component of a gaseous mixture. This invention especially relates to an adsorption process for providing an enriched gas stream by means of a pressure swing adsorption system using carbon molecular sieves.
More particularly, this invention relates to a method for providing an inexpensive and high volume source of gases such as nitrogen, hydrogen or methane, requiring less energy to operate than either cryogenic or other pressure swing adsorption systems, and yet supplying gases of comparable quality.
The term gaseous mixture, as used herein, refers to air and other gas mixtures primarily comprised of at least two components of different molecular size. The term enriched gas refers to a gas comprised of that component of the gaseous mixture relatively unadsorbed after passage of the gaseous mixture through a two column adsorption zone (connected in series). The term lean gas refers to a gas passed through only one column of a two column adsorption zone having a fraction of undesirable components less than that of the starting gaseous mixture but more than that of the desired product gas.
A gaseous mixture may be fractionated, or separated, using pressure swing adsorption by passing the mixture at an elevated pressure, hereinafter referred to as the adsorption pressure, through a column of adsorbent which is selective in its capacity to adsorb one or more of the components of the mixture. This selectivity is governed by the pore size distribution in the adsorbent and the pore volume of the proper pore size for adsorption of a particular gas component. Thus, gas molecules with a kinetic diameter less than or equal to the pore size are retained, or adsorbed, on the adsorbent while gas molecules of larger diameters pass through the column. The adsorbent, in effect, sieves the gas according to the component's molecular size. The gaseous mixture may also be fractionated because of different rates of diffusion of its components into the pore system of the adsorbent.
As the gas travels through the adsorbent column, the pores are filled with gas molecules. One can envision an adsorption front, moving through the column, akin to the liquid adsorption front moving through a solid adsorbent in a column chromatography system. After some time the gas exiting the column is essentially the same in composition as the gas that entered the adsorbent. This is known as the "breakthrough" point. At some time before this breakthrough point, the column must be regenerated.
After treatment of the mixture to adsorb selected components therefrom, the flow of the gaseous mixture through the column is interrupted and the adsorbent is regenerated for reuse by purging it of the adsorbed components either by vacuum or by passing through the column, generally in the opposite direction of flow taken by the gaseous mixture, a purge gas stream which may comprise a portion of the purified product at a low pressure.
Pressure swing adsorption usually includes at least two columns of adsorbent so that while one column is being regenerated, the other is in the adsorption phase producing product gas. Thus, by cycling between the columns product gas is obtained constantly. The term adsorption zone, as used herein, refers to a serial arrangement of two adsorption columns, i.e., during adsorption, gas enters the inlet of the first column in the zone and exits the zone via the outlet of the second column comprising the zone. When using two such zones, by cycling between these zones, product gas is obtained constantly.
The recovery of oxygen enriched air utilizing an adsorption process employing siliceous or carbon containing adsorption agents and involving the use of temperature or pressure changes during adsorption and desorption is well known. See for example, Nandi and Walker, Separation Science 11 441 (1976), "Separation of Oxygen and Nitrogen Using 5 A Zeolite and Carbon Molecular Sieves." Certain silicates, as for example zeolites, are effective for preferably adsorbing nitrogen from its mixtures with oxygen so that by conducting air through a zeolite filled column, the first issuing gas is effectively enriched in oxygen content. The regeneration of zeolites however requires considerable expense in terms of energy and apparatus. For example Wilson in U.S. Pat. No. 3,164,454 describes the separation of oxygen from air using zeolites.
A well known process is the use of carbon molecular sieves for the production of enriched nitrogen from air. See for example, Vesterdal, U.S. Pat. No. 2,556,859 and Munzner et al., U.S. Pat. No. 3,960,522. These sieves possess a pore structure with a size comparable to the kinetic diameter of oxygem. When used in a pressure swing adsorption systen, these sieves selectively adsorb oxygen from a gas mixture, allowing other components to pass.
A four column pressure swing adsorption unit has been successfully employed in the separation of hydrogen gas from its mixture with carbon dioxide, water and light aliphatic hydrocarbons. See for example, Wagner in U.S. Pat. No. 3,430,418.
Also well known is the fractionation of other binary gas mixtures by pressure swing adsorption. For example, carbon monoxide from its mixture with hydrogen using zeolite 13X and carbon dioxide from its mixture with fuel gas mixtures using charcoal, alumina or silica. See, Simonet, U.S. Pat. No. 3,884,661.
Binary gas mixtures of argon and oxygen or helium and methane have been separated on an adsorbent of partially oxidized carbon in a pressure swing adsorption process. See, German Auslegungsschrift No. 2,045,200.
Typical problems in the present carbon molecular sieve technology include; low yield of product gas, large amounts of molecular sieve required and energy inefficient regeneration methods.
SUMMARY OF THE INVENTION
The invention relates to a four-column pressure swing adsorption process for fractionating a gaseous mixture through two columns containing molecular sieve carbon arranged in series, herein called the adsorption zone, at a pressure selected from within the range of 3.0 to 8.0 bars, subsequently reducing the pressure of the adsorption zone to atmospheric level by countercurrently venting the residual gas in the interstices of the carbon columns and a part of the adsorbed gas, regenerating the carbon columns of the adsorpton zone by vacuum in the range of 70 to 250 torr, partially restoring the pressure of the adsorption zone by introducing the gas exiting the second carbon column of a second serially connected two column adsorption zone (also referred to as lean gas) into its inlet to about 40 to 90% of the adsorption pressure while feeding the gaseous mixture solely through the inlet of the second carbon column of this other adsorption zone, stopping the lean gas flow, and further restoring the adsorption pressure completely by introducing product quality gas into the zone's outlet end, and then repeating sequence, treating the second zone as the first zone and vice versa.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE is a schematic representation of one apparatus capable of employing the gas fractionation and repressurization process described herein.
DETAILED DESCRIPTION
There is provided an adsorption process for the generation of a stream of enriched gas which comprises the sequential steps of passing a gaseous mixture at a pressure selected from the range of 3.0 to 8.0 bars, through a first adsorption zone having a first and a second column of carbon molecular sieves, connected in series, yielding enriched gas, prior to breakthrough, isolating said first column of said first adsorption zone, thereafter passing the gaseous mixture through the second column of this first adsorption zone, thereby producing lean gas and passing said lean gas from said second column of said first adsorption zone into the inlet end of a second adsorption zone having a first and a second column of carbon molecular sieves, connected in series, thereby partially pressurizing said second adsorption zone in a range of 40 to 90% of the adsorption pressure, thereafter halting the lean gas flow and further pressurizing the second adsorption zone to the adsorption pressure by the introduction of enriched gas of product quality (generally, but not exclusively from the product reservoir) through the outlet end of the zone, venting said first column of the first adsorption zone to atmospheric pressure, countercurrently venting the second column of the first adsorption zone, using said vented gas to countercurrently purge the previously vented first column in the zone, passing the gaseous mixture through the pressurized second adsorption zone to yield enriched gas while regenerating the entire first adsorption zone by the use of vacuum applied to the inlet end of the zone in the range of 70 to 250 torr and repeating the cycle prior to breakthrough, generally upon reaching an undesirable level of previously adsorbed (unwanted) gas in the enriched gas stream.
The system for employing the fractionation and repressurization technique of this invention can be better understood by reference to the accompanying drawing which shows a two zone pressure swing adsorption unit capable of fractionating a binary gas mixture in accordance with this invention. Although the present invention is described and illustrated in connection with a preferred embodiment, it is to be understood that modifications and variations may be used without departing from the spirit of the invention. For example, any gaseous mixture including, but not limited to, air (nitrogen and oxygen), methane and carbon dioxide, or hydrogen and carbon monoxide will suffice.
Referring to the drawing in detail, there is shown four pressure resistant columns A & B and C & D, each of which is filled with carbon molecular sieves suitable for the fractionation of nitrogen from air. Generally, these carbon molecular sieves have a controlled pore structure which is developed during the manufacture of the sieve. This pore structure allows for the discrimination and hence separation of gases of different molecular size. One carbon sieve useful in this process is described in Juntgen et al., U.S. Pat. No. 4,124,529. In general, any adsorbent capable of screening out one or more components of a gaseous mixture based on a molecular size differential, may be employed in this process. Columns A & B comprise the first adsorption zone (zone-1) while columns C & D comprise the second adsorption zone (zone-2). Each zone has an inlet end (zone-1=Column A, zone-2=Column C) and an outlet end (zone-1=Column B, zone-2=Column D).
The series of valves connecting the pressure resistant columns may be defined by the number shown in the drawing and by the function performed in this one preferred arrangement:
(a) Valves 0 & 1--main air flow valves.
(b) Valves 2, 7 & 11, 16--inlet air valves to columns A, B & C, D respectively.
(c) Valves 3 & 12--regeneration valves--vacuum pump for zones 1 & 2.
(d) Valves 4 & 13--purge valves--release column pressure for zones 1 & 2.
(e) Valves 10 & 19--product flow valves--from adsorption zones 1 & 2.
(f) Valves 20, 8 & 17--backfilling valves--product quality gas introduced into outlet end of zones 1 & 2 after partial repressurization.
(g) Valves 9, 14, 15 & 5, 6, & 18--exiting (lean) gas connection between outlet of first adsorption zone and inlet of second adsorption zone.
(h) Valves 6 & 15--zone purge connection--gas from second half of zone used to purge first half.
While housings A, B, C and D are shown in the vertical position, they may be installed in either the horizontal or vertical position without adverse effect to the mode of operation.
Ambient air is compressed and dried and introduced into the system via either valve 0 or valve 1. The ambient air may be modified, prior to adsorption, by passing it through a condenser to remove excess humidity as a relative humidity of less than 40% is preferred. Also, a filter or scrubber may be employed to remove other gasses such as carbon dioxide, sulfur dioxide or oxides of nitrogen. These steps improve the purity of the enriched gas stream and are employed when the specification for extremely pure enriched gas (e.g., nitrogen) mandates such prior removal. They are however auxiliary and not requisite to the successful operation of this invention.
Air is admitted to either zone-1 or zone-2 at the adsorption pressure via valve 0 and either valves 2 & 6 or valves 11 & 15 to selectively sieve oxygen and the air is pushed through the adsorption zone. Enriched nitrogen gas is discharged from zone-1 or zone-2 via either valve 10 or valve 19 respectively. The instantaneous nitrogen flow rate is measured by a mass flow meter and the enriched gas oxygen content is analyzed upstream from the enriched reservoir. A stream of enriched nitrogen gas is discharged from the product reservoir to keep its pressure constant.
When one adsorption zone is generating enriched nitrogen gas, the other zone is being regenerated by vacuum applied via valves 3 or 12. Thus, while zone-1 is producing nitrogen via open valves 0, 2, 6 and 10, zone-2 is being regenerated by vacuum in the range of 70 to 250 torr via open valve 12.
Prior to reaching the breakthrough point of an adsorption zone, when an analysis of the enriched nitrogen gas oxygen content shows that an undesirable level of oxygen, for example, greater than from 1 to 10% has been reached valves 0, 2, 6, and 10 or valves 0, 11, 15 and 19 are closed. The first column of zone-1 (column A) or zone-2 (column C) is thus isolated. Air is then admitted solely into the second column of zone-1 (column B) or zone-2 (column D) via valves 1 and 7 or 1 and 16 respectively. The lean gas exiting from this column flows through either valves 9, 14 and 15 or valves 18, 5 and 6 to the inlet end of zone-2 or zone-1. This lean gas is used to partially pressurize the other zone to a range of 40-90%, preferably 60-70%, of the adsorption pressure. After this step the lean gas flow is ceased and the partially pressurized zone is further pressurized to the adsorption pressure by the introduction of enriched product nitrogen gas via valves 20 and 17 for zone-2 or valves 20 and 8 for zone-1 from the product reservoir. During this time the isolated first column of the first adsorption zone is returned to atmospheric pressure by venting through valves 3, 4 or 13. Once the partial repressurization (lean gas) phase is completed, the second column of the adsorption zone (i.e., Column B or Column D) is countercurrently depressurized via valve 6 or valve 15 and the previously vented, and isolated first column (i.e., column A or Column C) is purged with the residual gas from the second column in the zone. The fully pressurized adsorption zone now receives feed air via valve 0 and either valve 11, 15 or valve 2, 6 and enriched gas is released via valves 19 or 10. While one adsorption zone is producing nitrogen gas, the other adsorption zone is being regenerated by the application of vacuum in the range of 70 to 250 torr via valve 3 or valve 12. The cycle is repeated prior to zone breakthrough, generally when the oxygen content of the enriched gas from the second adsorption zone again reaches an undesirable level, for example greater than from about 1 to 10 percent.
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Gaseous mixtures are separated on a two zone (two columns connected in series per zone) carbon molecular sieve pressure swing adsorption system to produced a gas stream enriched in at least one component. This process includes the partial pressurization of an adsorbent zone with lean gas in the range of 40 to 90 percent of the adsorption pressure.
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FIELD OF THE INVENTION
The invention generally relates to semiconductor quantum-well structures. In particular, the invention relates to InP and InGaAs quantum-well diode lasers whose fabricational variations can be better controlled.
BACKGROUND ART
Many advanced electronic and opto-electronic integrated circuits are based on compound semiconductors such as the III-V semiconductors. Gallium arsenide (GaAs) is the basis of a fairly well developed technology: indium phosphide (InP) and related materials are not so well developed but have received much attention, especially for active opto-electronic devices, such as lasers and optical modulators, operating in the 1.55 μm band of optical wavelengths which is of great interest for integration with silica optical fibers. Indium gallium arsenide (InGaAs) is often considered to be an InP-based material because alloys with InP can be made that have little change in lattice constant while providing bandgap control of the commercially important part of the optical spectrum around 1550 nm.
A fundamental advantage of III-V semiconductors is that modern film growth techniques, such as organo-metallic chemical vapor deposition (OMCVD) and molecular beam epitaxy (MBE), enable the epitaxial growth of thin films with nearly arbitrary III-V compositions, assuming equality of Group-III cations and Group-V anions, thus allowing many important semiconductor characteristics such as electronic bandgap to be freely engineered. Similar freedom is available with II-VI semiconductors. An important structure that is so enabled is the single or multiple quantum-well (MQW) structure much used for lasers and modulators, an example of which is illustrated schematically in FIG. 1 with the horizontal axis representing the epitaxial growth direction and the vertical axis representing the electronic bandgap for the different materials. For example, an electronic diode structure includes an n-type InP layer 10 and a p-type InP layer 12 sandwiching an undoped active layer 14 comprising alternating thin layers of InGaAs wells 16 and InGaAsP barriers 18. The wells and barriers 16 and 18 are thin enough, usually less than 10 nm, that one or more quantum mechanical valence states 20 and conduction states 22 form within the wells 16. The number of quantum wells may be one or more.
The effective bandgap between the valence and conduction states 20, 22 within the wells 16 depend both upon the well composition and the thickness of the well.
Although the compositions are generally chosen to be lattice matched to the InP substrate, a controlled amount of strain can be introduced into the wells and barriers to further control the electronic band structure. The result is an active layer 14 having a high density of narrow electronic states, assuming the wells 16 have been well fabricated, with the effective bandgap that determines optical characteristics being easily varied. In a typical opto-electronic device, electrical leads are connected to the two InP layers 10, 12 and an unillustrated optical waveguiding structure is formed along the active layer 14 in the directions perpendicular to the illustrated z-direction so as to confine a major portion of the optical wave within the active layer 14 to there interact with the electrically controlled carriers.
However, the process of forming the optical confinement structure tends to degrade the multi quantum-well structure. A typical though sim heterostructure MQW laser is illustrated in cross section in FIG. 2. The vertical planar structure of FIG. 1 is grown and then patterned and etched so as to form a ridge extending along the v-direction and having a finite width along the x-direction of the active layer 14 including the multiple quantum wells. Thereafter, a semi-insulating InP 24 is epitaxially regrown around the ridge to reduce the contrast of the refractive index of the active layer 14 relative to that of the surrounding material and to confine the biasing current to the active layer 14. The structure shown in FIG. 2 is simplified for ease of presentation.
More layers may be included to, for example, better confine the light to the core, but the illustrated structure is sufficient to explain the effect of the invention. More realistic structures for buried heterostructure lasers are described by Odagawa et al. in "High-Speed Operation of Strained InGaAs/InGaAsP MQW Lasers Under Zero-Bias Condition," IEEE Journal of Quantum Electronics, vol. 29, 1993, pp. 1682-1686 and by Aoki et al. in "Monolithic integration of DFB lasers and electroabsorption modulators using in-plane quantum energy control of MQW structures, International Journal of High Speed Electronics and Systems, vol. 5, 1994, pp. 67-90.
The regrowth of the fairly thick semi-insulating layer 24 imposes a large thermal budget on the already fabricated quantum wells. Even the after grown upper cladding layer 12 incurs a significant thermal budget. OMCVD of these materials is typically done between 625° and 650° C. so that temperatures between 600° and 700° C. should be anticipated. Even higher temperatures may be required for explicit annealing. The thermal treatment of the quantum wells in these temperature ranges has been generally observed to shift the bandgap between the well states to the blue. That is, the effective bandgap of the well states anneal to larger bandgap energy. Also, the potential wells tend to lose their rectangular shape. The structure described by Aoki et al., ibid., includes both lasers and modulators having different well thickness and involves two regrowths, one for the upper, p-type InP layer and another for the semi-insulating InP. Thus significant blue shifting is expected, but the amount of blue shift will differ between the laser and modulator because of the differing well thicknesses.
The size of the blue shift has been observed to shift the photoluminescence peak by about 10 to 40 nm at devices designed for 1550 nm. However, the shift varies across a wafer and from wafer to wafer. A shift in the wavelength peak of the photoluminescent emission presents a problem in fabricating lasers and modulators since, for example, optimum performance in distributed feedback lasers requires the wavelength of the gain peak to match the grating pitch. In the case of modulators, a variation of the blue shift between different ones of the multiple quantum wells will produce a less steep change of absorption with wavelength, thereby degrading the modulator performance.
Several suggestions have been made to reduce the blue shift. One entails the use of substrates with high dislocation densities, the dislocation pipes acting as gettering sites for the species, speculated to be phosphorus interstitials, responsible for the blue shift. This solution is not attractive because heavily dislocated substrates introduce concerns about the reliability of devices formed on them.
Another suggestion involves the use of strained quantum wells in which both the wells and the barriers have the same compositional ratio As/P of the Group-V components, thereby avoiding any effect from the mobile phosphorus. Although this solution seems effective, it restricts the device design.
Several groups have reported their understanding of the mechanism for blue shift in Proceedings of Fifth International Conference on Indium Phosphide and Related Materials, Apr. 19-22, 1993, Paris, France (IEEE Catalog #93CH3276-3). See Glew, "Interdiffusion of InGaAs/InGaAsP quantum wells," ibid., pp. 29-32; Gillin et al., "Group V interdiffusion in In 066 Ga 033 As/In 066 Ga 033 As 07 P 03 quantum well structures," ibid., pp. 33-35; Camassel et al., "Experimental investigation of the thermal stability of strained InGaAs/InGaAsP MQWs," ibid., pp. 36-39; and Vettese et al., "An investigation into the effects of thermal annealing on long wavelength InGaAs/InGaAsP multi-quantum well lasers," Ibid., pp. 40-44. Although diffusion of phosphorus is a recurring theme, there is no agreement on the responsible mechanism.
Accordingly, a more reliable and less restrictive method is desired for controlling and reducing the blue shift in InP-based and related quaternary quantum-well structures.
SUMMARY OF THE INVENTION
The invention can be summarized as a quantum-well structure based on compound semiconductors, particularly InP, InGaAs, and related III-V semiconductors, in which a barrier layer is formed between the quantum wells and the substrate. Preferably, the barrier layer contains aluminum, e.g., may be AlGaInAs, and it prevents the diffusion of species from the substrate into the quantum wells that would otherwise cause a blue shift in the quantum-well electronic states.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematical representation of the composition and band structure of a conventional semiconductor diode having a multi quantum-well active layer.
FIG. 2 is a cross-sectional view of a conventional buried heterostructure laser incorporating the multi quantum-well structure of FIG. 1.
FIG. 3 is a cross-sectional view of a first embodiment of the invention including an AlGaInAs barrier layer below multiple InP-based quantum wells and above an InP buffer layer.
FIG. 4 is a cross-sectional view of a second embodiment of the invention including the AlGaInAs barrier layer below the InP buffer layer.
FIG. 5 is a cross-sectional view of a third embodiment of the invention including a principal InP buffer layer and in which the AlGaInAs barrier layer is subdivided and interleaved with additional InP buffer layers.
FIG. 6 is a cross-sectional view of a fourth embodiment of the invention which lacks the principal InP buffer layer of the third embodiment.
FIG. 7 is cross-sectional view of a fifth embodiment of the invention including a barrier layer formed over the quantum wells.
FIGS. 8 and 9 are cross-sectional view of sixth and seventh embodiments of the invention is which the barrier layer is patterned to provide laterally varying blue shifts.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
According to the invention, a III-V semiconductor layer including a substantial aluminum content acts as a diffusion barrier for quantum-well layers grown on its top. In a particularly important application of the invention, a layer of AlGaInAs is epitaxially deposited above an InP substrate to act as an effective diffusion barrier against species in the substrate so as to protect quantum wells and barriers formed on the AlGaInAs barrier layer. The quantum-well structure is composed of compound semiconductors, such as the III-V material combinations of InGaAsP/InGaAs, InGaAsP/InGaAsP, InP/InGaAs, and InP/InGaAsP.
The thickness of the barrier layer preferably lies within the range of 100 nm to 500 nm. The preferred AlGaInAs barrier material has a composition that is preferably lattice matched to InP although it can be slightly strained as long as the thickness of a strained layer does not exceed the pseudomorphic limit beyond which dislocations are generated. Preferably, the AlGaInAs barrier material has an Al content between an AlInAs composition and an AlGaInAs composition providing a bandgap wavelength of λ g =1.3 μm. The bandgap energy of Al x Ga y In 1-x-y As that is lattice matched to InP is given by
E.sub.g (eV)=0.75+1.548x, (1)
with
1-x-y=0.53, (2)
and the bandgap wavelength is given by ##EQU1## The barrier layer may additionally contain other constituents to provide more complete bandgap and strain engineering. In particular, some phosphorus may be included.
A first embodiment of the invention is shown in cross section in FIG. 3. On an n + -type InP substrate 30 are epitaxially deposited an n + -type InP buffer layer 32 having a thickness of 0.5 to 1.0 μm, over which is epitaxially deposited an AlGaInAs barrier layer 34 having a photoluminescent bandgap of λ g =0.95 μm. Its thickness is the range of 0.1 to 0.5 μm. In general, in a diode structure the layers on opposite sides of the active region are fairly heavily doped to opposite conductivity types. However, the doping is required only if the layer is relatively thick. If their thickness is 0.1 μm or less, undoped or partially doped layers still provide the required conductivity to the active region. Here, an undoped 1 μm-thick AlGaInAs barrier layer 34 becomes part of the adjacent active region.
An undoped multi quantum-well structure is epitaxially deposited over the barrier layer 34, and it includes 5 periods of alternating quantum-well layers 36 and barrier layers 38 plus an additional end barrier. The quantum-well layer 36 has a composition of InGaAs with a tensile strain of σ=-0.3% and a thickness of 7 nm. The barrier layer has a composition of InGaAsP with λ g =1.2 μm and a thickness of 10 nm. Over the quantum-well structure is epitaxially grown an InP undoped protective capping layer 40 having a thickness of about 0.1 μm. The composition of the capping layer 40 was chosen for experimental purposes and to provide a close comparison to the comparative example. In commercial devices, the capping layer may be formed of the quaternary InGaAsP although it is not clear that would even be required. Other layers may be grown over the capping layer 40 depending on the requirements of the optical structure. In any case, the AlGaInAs barrier layer 34 prevents interdiffusion between the quantum-well structure 36, 38 and the InP substrate 30. The specific structure, compositions, and thicknesses presented both above and below are understood to be by way of example only. Alternative embodiments of the invention may differ.
The second embodiment of the invention shown in the cross section of FIG. 4 differs from that of FIG. 3 in that the AlGaInAs barrier layer 34 is placed beneath the InP buffer layer 32 and the buffer layer 32 is adjacent to the quantum-well structure 36, 38. This embodiment recognizes the fact that the 1 μm-thick buffer layer 32 contributes little to the diffusion of Group-V components, if indeed that is the cause of blue shifting, so that the buffer layer 32 can be placed between the barrier layer 34 and the quantum-well structure 36, 38.
The third embodiment of the invention shown in the cross section of FIG. 5 differs from the second embodiment of FIG. 4 in that the AlGaInAs barrier layer is divided into five n + -type AlGaInAs (λ g =1.2 μm) barrier sub-layers 44 interleaved with four n + -type InP buffer sub-layers 46 in a superlattice structure. The AlGaInAs barrier sub-layers 44 and the InP buffer sub-layers 46 all have thicknesses, for example, of 0.1 μm. The buffer sub-layers 46 together with the initial InP buffer layer 32 present a high-quality substrate for subsequent epitaxial growth while the barrier sub-layers 44 prevent interdiffusion of species within the underlying InP into the quantum-well structure 36, 38. In the third embodiment, the material immediately underlying the quantum-well structure 36, 38 is one of the barrier sub-layers 44 so that not even a thin InP layer has unimpeded access to the quantum wells.
The fourth embodiment of the invention illustrated in cross section in FIG. 6 differs from the third embodiment of FIG. 5 in that it lacks the initial InP buffer layer 32, so that the superlattice of the barrier and buffer sub-layers 44, 46 is grown directly on the substrate 30.
The fifth embodiment of the invention illustrated in cross section in FIG. 7 improves upon the first embodiment of FIG. 3 in including a barrier layer above the quantum-well structure. In particular, a thin upper InP protective layer 50 is epitaxially formed over the quantum-well structure 36, 38 to a thickness of 10 nm. This layer 50 was included for experimental purposes and in commercial devices may be replaced by a quaternary InGaAsP protective layer or dispensed with completely. Over the thin protective layer 50 are formed an upper AlGaInAs barrier layer 52 having a thickness of 0.1 μm and then the 0.1 μm-thick InP capping layer 40. The upper barrier layer 52 protects the quantum-well structure 36, 38 from the phosphorus-containing phosphine environment used in an annealing step and also protects it from interdiffusion from the InP capping layer 40 and whatever layers are formed thereover, although it is not clear that interdiffusion from overgrown epitaxial layers is a problem. In any case, the upper InP protective layer 50 is so thin that it does not present a significant source of blue-shifting species.
In some of the experimental samples, up to 2 μm of InP have been grown over an quantum-well structure not protected on its upper side by a barrier layer. No blue shifts have been attributed to this thick InP overlayer. It is thus believed that the species responsible for blue shifts originates from the much thicker InP substrate.
EXPERIMENT
The inventive structure of the first embodiment of FIG. 3 was grown by OMCVD at 76 Torr and at a growth rate of about 1.3 nm/s. The precursor reagents were trimethylgallium, trimethylaluminum, arsine, and phosphine in a carrier gas of hydrogen. lhydrogen sulfide or disilane was used to obtain n-type doping; diethylzinc was used for p-type doping. A comparative structure was grown with the same general structure and by the same process, but it lacked the AlGaInAs barrier layer 34.
After the inventive and comparative structures were grown, they were both subjected to a planar regrowth process typical of forming a buried MQW heterostructure waveguide. Then, the quantum-well structure was tested for its photoluminescence, both before and after the regrowth. The results are shown in TABLE 1.
TABLE 1______________________________________ Photoluminescence Peak Before Regrowth Blue Shift (nm) (nm)______________________________________Inventive 1515 0-2ExampleComparative 1515 13.6-23.2Example______________________________________
These data show that the blue shift of the 1515 nm peak was reduced by almost a factor of ten by use of the invention.
The invention allows the blue shift to be localized to selected areas of the opto-electronic integrated circuit. Such a process is particularly useful for integrating both lasers and modulators onto the same OEIC, the two elements requiring somewhat different peaks in the MQW emission spectra. Similar selective blue shifting has been described by Francis et al. in "Selective band-gap blueshifting of InGaAsP/InGaAs(P) quantum wells by thermal intermixing with phosphorus pressure and dielectric capping," Journal of Applied Physics, vol. 75, 1994, pp. 3507-3510 and by Hamoudi et al. in "Controlled disordering of compressively strained InGaAsP multiple quantum well under SiO:P encapsulant and application to laser-modulator integration," Journal of Applied Physics, vol. 78, 1995, pp. 5638-5641. The selective blue shifting of the invention provides more flexibility than the process that described by Aoki et al., ibid, in achieving different characteristic wavelengths in integrated lasers and modulators.
According to the invention, the selective localization of the blue shift is accomplished by patterning one or more barrier layers. A sixth embodiment of the invention utilizing localized blue shifting, illustrated in cross section in FIG. 8, differs from the second embodiment of FIG. 4 in that a bottom AlGaInAs barrier layer 60 partially underlying an InP buffer layer 62 beneath the quantum-well structure 36, 38 is patterned into two sets of regions 64, 66. Except for the patterning, the barrier layer 60 is same as barrier layer 34 of FIG. 4 and the buffer layer 62 is the same as buffer layer 32 of FIG. 4, but the buffer layer 62 additionally acts as a planarizing layer to smoothly cover the apertured barrier layer 60. The first set of regions 64 include the barrier layer 60 and thus experience minimal blue shift; however, the barrier layer 60 does not does extend into the second region 66, which thus experiences substantial blue shifting.
A related seventh embodiment of the invention patterns a barrier only above the quantum wells. As illustrated in cross section in FIG. 9, the quantum-well structure 36, 38 is grown directly on the InP buffer layer 32 with no underlying barrier layer. Instead a barrier layer 68 having the physical characteristics of the barrier layer 34 of FIGS. 3 and 4 is deposited and patterned so that the barrier layer 68 exists in first regions 70 but is absent in a second region 72. An InP capping layer 74 is deposited over the patterned barrier layer to both protect the underlying structure and to planarize its upper surface.
In the seventh embodiment, the barrier layer 68 in the first regions 70 prevents the further upward migration of the species responsible for the blue shift, which are relatively free to migrate upwardly from the InP substrate 30. Hence, the species accumulate in the quantum-well structure 36, 38 within the first regions 70 and a large blue shift is observed there. However, in the second region 72 unprotected by an upper barrier, the blue shifting species migrate through the quantum-well structure 36, 38 and continue upwardly from there. Hence, some of the blue shifting species remain in the second region 72 but to a lesser amount than in the first regions 74. Therefore, there is some blue shift in the second region 72 but less than the blue shift in the first regions 70.
Although the patterned cross sections of FIGS. 8 and 9 show a fairly narrow aperture in the barrier, a particularly useful application of the patterned blue shifting using fairly large patterning and includes a MQW diode laser positioned within the lowerenergy, less blue-shifted region and an MQW optical modulator positioned within the higher-energy, more blue-shifted region.
Although the examples and described embodiments of the invention have included multiple quantum-wells, the invention can be applied to structures with single quantum wells and other devices requiring very thin semiconductor layers where the thickness is critical.
Although the quantum wells of the described embodiments have been incorporated into a buried heterostructure laser waveguide, the invention is not so limited. Optical MQW structures can be formed in a number of configurations and for different uses, for example, the described optical modulators. Indeed, quantum wells can be advantageously used in non-optical electrical circuits.
The invention thus provides an easy and economical method of reducing the blue shift in quantum-well devices. For unpatterned barriers, an extra deposition step is required for each barrier layer or sub-layer, but the extra growth incurs little penalty. For patterned barriers, an extra step of lithographically defining the barrier layer is required, but two regions of differing bandgap are thereby obtained.
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An InP-based opto-electronic integrated circuit including an active layer having one or more quantum wells (36, 38). According to the invention, a barrier layer (34) of AlGaInAs is formed, preferably between the quantum wells and the substrate (30) to prevent the migration of species from the substrate and lower InP layers that tend to shift the emission wavelengths of the quantum wells to shorter wavelengths, i.e., a blue shift. The barrier layer can be patterned so that some areas of the quantum wells exhibit blue shifting to a shorter wavelength while other areas retain their longer wavelength during annealing.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to Chinese Patent Application No. 201610358437.1, filed May 26, 2016, the contents of which are incorporated by reference in the entirety.
FIELD
[0002] The present disclosure relates to supports for video playback devices.
BACKGROUND
[0003] Conventional supports for video playback devices are adapted to be placed on a horizontal surface. The conventional supports for video playback devices are useless when a user lies down, thus causing inconvenience to the user and reducing the user's sense of experience.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
[0005] FIG. 1 is a schematic perspective view of a support for video playback devices of the present disclosure.
[0006] FIG. 2 is a schematic exploded perspective view of the support for video playback devices of FIG. 1 .
[0007] FIG. 3 is a schematic exploded perspective view of the support for video playback devices of FIG. 1 shown in another viewing direction.
[0008] FIG. 4 is an enlarged view of IV in FIG. 2 .
DETAILED DESCRIPTION
[0009] It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the exemplary embodiments described herein. However, it will be understood by those of ordinary skill in the art that the exemplary embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the exemplary embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features of the present disclosure.
[0010] The term “comprising” means “including but not limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series, and the like.
[0011] With reference to FIG. 1 , an exemplary embodiment of a support 1 is adapted to support a video playback device 2 for facilitating viewing of the video playback device 2 by a user. The video playback device 2 may be a smart phone, tablet, MP4, and so on. The support 1 includes a headwear device 11 , a support mechanism 12 , and a holding mechanism 13 . The support mechanism 12 is connected between the headwear device 11 and the holding mechanism 13 . The holding mechanism 13 is used to hold the video playback device 2 . Viewing distance and angle of the video playback device 2 is adjusted by varying relative positions of the headwear device 11 and the support mechanism 12 and by varying relative positions of the support mechanism 12 and the holding mechanism 13 .
[0012] With further reference to FIG. 2 , the holding mechanism 13 includes a holder 131 , two positioning members 132 , and a space 1313 . The holder 131 has a body 1311 , two baffles 1312 , and a plurality of slots 1314 . The body 1311 has an inner surface and an outer surface. The baffles 1312 extend perpendicular from the inner surface of the body 1311 . The slots 1314 are formed through at least one of the baffles 1312 . The two positioning members 132 are respectively inserted into two of the slots 1314 . The space 1313 is defined between the body 1311 , the baffles 1312 , and the positioning members 132 , and is adapted to receive the video playback device 2 . The two positioning members 132 may be inserted into different slots 1314 to adjust a size of the space 1313 so as to hold different sized video playback devices 2 in the space 1313 . In the present exemplary embodiment, the holder 131 is integrally molded from polypropylene. The body 1311 is rectangular and has two long sides and two short sides. The two baffles 1312 respectively extend perpendicular from the two long sides of the body 1311 . The width of each slot 1314 is 4 mm.
[0013] With further reference to FIG. 3 , in the present exemplary embodiment, each slot 1314 is formed through the at least one baffle 1312 and the body 1311 . Each positioning member 132 is integrally molded from polypropylene, and includes an insertion portion 1321 , a holding portion 1322 , and an operating portion 1323 . The holding portion 1322 is adapted to hold the video playback device 2 , and has an inner surface and an outer surface. The insertion portion 1321 is formed on the inner surface of the holding portion 1322 , and is inserted into the slot 1314 . The operating portion 1323 is formed on the outer surface of holding portion 1322 , and is provided for the user to insert the insertion portion 1321 into the slot 1314 . The contact area between the holding portion 1322 and the video playback device 2 may be adjusted by changing the width of the holding portion 1322 , thereby ensuring that the video playback device 2 is securely held by the holding portion 1322 .
[0014] In the present exemplary embodiment, the body 1311 has two holes 13111 . The holding mechanism 13 further includes a shaft 133 . The shaft 133 is mounted on a middle portion of the outer surface of the body 1311 , and has two holes 1330 , and two ends. The two holes 1330 of the shaft 133 respectively align with the two holes 13111 of the body 1311 . Two screws respectively pass through two groups of aligned holes 1330 , 13111 of the shaft 133 and body 1311 to secure the shaft 133 to the body 1311 . The two ends of the shaft 133 respectively protrude from the two short sides of the body 1311 . The support mechanism 12 includes two support rods 121 and two first screws 122 . Each support rod 121 is integrally molded from polypropylene, and has a plurality of holes 1211 along its longitudinal direction. The two ends of the shaft 133 are respectively inserted into two holes 1211 of the two support rods 121 . The two first screws 122 respectively pass through the two ends of the shaft 133 to secure the shaft 133 to the two support rods 121 . The two ends of the shaft 133 may be inserted into different holes 1211 of the two support rods 121 to vary the relative positions of the holding mechanism 13 and the support mechanism 12 so as to adjust the viewing distance of the video playback device 2 . In another exemplary embodiment (not shown), the support mechanism 12 includes two support rods 121 . Each support rod 121 has a chute. The holding mechanism 13 further includes two sliders at its opposite sides. The two sliders are respectively received in the chutes of the two support rods 121 . The two sliders may slide in the chutes of the two support rods 121 to vary the relative positions of the holding mechanism 13 and the support mechanism 12 so as to adjust the viewing distance of the video playback device 2 . In still another exemplary embodiment (not shown), the support mechanism 12 includes two support rods 121 . Each support rod 121 has a groove with teeth. The holding mechanism 13 further includes a shaft 133 having two ends. The two ends of the shaft 133 are respectively inserted into the grooves of the two support rods 121 . The shaft 133 may be moved along the grooves of the two support rods 121 to vary the relative positions of the holding mechanism 13 and the support mechanism 12 so as to adjust the viewing distance of the video playback device 2 . In still another exemplary embodiment (not shown), the headwear device 11 may be connected to the support mechanism 12 by the connection structure of the holding mechanism 13 and the support mechanism 12 described in the exemplary embodiments above, and the relative positions of the headwear device 11 and the support mechanism 12 may be varied to adjust the viewing distance of the video playback device 2 .
[0015] In the present exemplary embodiment, the headwear device 11 includes a housing 111 , a head pad 112 , a neck pad 113 , two ear pads 114 , an earphone 115 , and two covers 116 . The housing 111 is integrally molded from polypropylene, is hollow to form a chamber 1113 therein. The chamber 1113 is adapted to receive the head of the user. The head pad 112 and the neck pad 113 are made of a soft material such as foam, and are attached to an inner surface of the housing 111 . The thickness of the head pad 112 is 8 mm, and the thickness of the neck pad 113 is 20 mm, to achieve a better user experience. The housing 111 has two side walls 1111 and a connecting wall 1112 between the side walls 1111 . The chamber 1113 is defined between the side walls 1111 and the connecting wall 1112 . A middle of an outer surface of the connecting wall 1112 is a flat surface 11121 . The headwear device 11 can be securely placed on a horizontal surface because of the flat surface 11121 . Each side wall 1111 has a receiving member 1114 at its outer surface. The earphone 115 has two speakers 1151 , a first wire 1152 , a second wire 1153 , and a plug 1154 . The two speakers 1151 are respectively received in the receiving members 1114 of the two side walls 1111 . The two covers 116 respectively cover openings of the two receiving members 1114 to hold the speakers 1151 in the receiving members 1114 . The two ear pads 114 are respectively attached to inner surfaces of the two side walls 1111 , and respectively correspond to the two speakers 1151 . The ear pads 114 are used in conjunction with the speakers 1151 to achieve a better sound effect.
[0016] In the present exemplary embodiment, each receiving member 1114 has four holes 1116 at its four corners, and each cover 116 has four protrusions 1161 corresponding to the four holes 1116 of the receiving member 1114 . The protrusions 1161 of the two covers 116 are respectively inserted into the holes 1116 of the two receiving members 1114 to secure the covers 116 to the receiving members 1114 . Each cover 116 further has a hole 1160 . The first wire 1152 has two ends respectively passing through the holes 1160 of the two covers 116 to connect the two speakers 1151 . The second wire 1153 has two ends, one of the ends of the second wire 1153 is connected to one of the ends of the first wire 1152 , and the other end of the second wire 1153 is connected to the plug 1154 . The plug 1154 is connected to the audio jack 21 of the video playback device 2 such that the user can listen to the audio signal of the video playback device 2 through the speakers 1151 .
[0017] With reference to FIGS. 2 and 4 , in the present exemplary embodiment, each cover 116 is made of aluminum alloy, and has a plurality of screw holes 1162 . Each support rod 121 has an end portion 1212 secured to the headwear device 11 , and a plurality of projections 123 extending therefrom adjacent to the end portion 121 . The end portion 1212 has a hole 12121 . Each projection 123 has at least one hole 1231 . The support mechanism 12 further includes a plurality of second screws 124 . Two second screws 124 respectively pass through the holes 12121 of the end portions 1212 of the two support rods 121 and respectively pass through two screw holes 1162 of the two covers 116 to secure the end portions 1212 of the support rods 121 to the covers 116 , another two second screws 124 respectively pass through the holes 1231 of two projections 123 of the two support rods 121 and respectively pass through another two screw holes 1162 of the two covers 116 to secure the projections 123 of the end portions 1212 to the covers 116 , such that the support rods 121 are fixedly mounted to the covers 116 . The two second screws 124 may pass through the holes 12121 of the end portions 1212 of the two support rods 121 and pass through different screw holes 1162 of the two covers 116 , and the another two second screws 124 may pass through the holes 1231 of different projections 123 of the two support rods 121 and pass through different screw holes 1162 of the two covers 116 , to vary the relative positions of the headwear device 11 and the support mechanism 12 , so as to adjust the viewing angle of the video playback device 2 .
[0018] In use, the video playback device 2 is placed in the space 1313 of the holding mechanism 13 , and the insertion portions 1321 of the positioning members 132 are inserted into the slots 1314 of the holder 131 such that the video playback device 2 is held by the holding portions 1322 of the positioning members 132 . The two ends of the shaft 133 are inserted into different holes 1211 of the two support rods 121 , and are secured by the first screws 122 , to adjust the viewing distance of the video playback device 2 . The two second screws 124 pass through the holes 12121 of the end portions 1212 of the two support rods 121 and pass through different screw holes 1162 of the two covers 116 , and the another two second screws 124 pass through the holes 1231 of different projections 123 of the two support rods 121 and pass through different screw holes 1162 of the two covers 116 , to adjust the viewing angle of the video playback device 2 .
[0019] The exemplary embodiments shown and described above are only examples. Many details are often found in the art such as the other features of a support for video playback devices. Therefore, many such details are neither shown nor described. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, especially in matters of shape, size, and arrangement of the parts within the principles of the present disclosure, up to and including the full extent established by the broad general meaning of the terms used in the claims. It will therefore be appreciated that the exemplary embodiments described above may be modified within the scope of the claims.
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A support for video playback devices includes a headwear device, a support mechanism, and a holding mechanism. The support mechanism is connected to the headwear device. The holding mechanism is connected to the support mechanism, and is used to hold a video playback device. Viewing distance and angle of the video playback device is adjusted by varying relative positions of the headwear device and the support mechanism and by varying relative positions of the support mechanism and the holding mechanism. The structure of the support for video playback devices is simple. The support for video playback devices is useful when a user lies down, thus improving the user's sense of experience.
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BACKGROUND OF THE INVENTION
The present invention relates to a superconductive magnet coil arrangement for generating a homogeneous magnetic field in a volume under examination, comprising a magnet coil having two first windings of a superconductive wire which are disposed adjacent the ends of the magnet coil and which are supported on a hollow supporting body enclosing the volume under examination, and comprising further at least one additional winding of a superconductive wire which is arranged in the area between the first windings and which is supported by the said supporting body, the windings being fixed against displacement in the axial direction.
A magnet coil of this kind has been known for example from EP-A-0 293 723 and EP-A-0 285 861. The supporting body, which displays a substantially cylindrical shape, comprises a plurality of winding chambers each containing one winding made from a superconductive wire. Flanges left between the winding chambers fix the windings rigidly in the axial direction. From EP-A-0 118 807 (GE) it has been known to arrange the windings radially inside a supporting body made from aluminium, and to provide low annular stops in order to thereby prevent the windings, i.e. the entire winding packages, from being displaced due to magnetic forces.
In the case of superconductive coils of the kind described above, Lorentz forces, which act on the superconductive wire in the axial direction of the coil, are encountered due to the existing radial components of the magnetic field. These forces sum up in each winding, which comprises a plurality of turns. At the axial inner end of the winding chamber, the forces are then transmitted to the flange and, via the supporting body, to the next winding chamber in the form of a pressure. Such a transmission of pressures to other winding chambers is not encountered in a disturbing manner only in such cases where a maximum of two windings are provided and arranged at an axial distance one from the other. The axial pressure sums up towards the middle of the coil and leads to a reduction in length of the supporting body in the area between the two axially outer windings, as a result of the axial pressures encountered. The highest forces, however, arise at the coil ends because there the radial components of the magnetic field reach their maximum if the current has the same intensity throughout.
It has been found by experiments that the pressure in the winding core must not exceed a certain maximum value which is predetermined by the properties of the material of the wire and by the winding technique. If the pressure gets excessively high, a coil of this type can no longer be operated at very high field strengths because the process of building up a high magnetic field Will be terminated, during charging of the coil, at some point or other by instable displacements of the winding turns. For a series of homogeneous coils with relatively high field strengths it is the pressure which limits the magnetic field strength. The described transmission of the axial pressure over the full length of the winding is also encountered in the case of the before-mentioned EP-A-0 118 807, because of an intimate interference fit existing between the windings, which are not delimited by lateral walls of the winding chambers, and the supporting body.
SUMMARY OF THE INVENTION
It is, therefore, desirable to reduce the influence of the pressure on the superconductive wire so as to achieve improved operating safety and/or higher field strengths, with unaltered homogeneity and field strength.
The present invention achieves this object by the fact that at least one of the additional windings is arranged on a winding core mounted on the supporting body and that the fixing means securing the said winding against axial displacement occupies an area in length of the winding core shorter than the winding arranged on the winding core.
In order to facilitate understanding, it will be assumed for the purposes of the following explanations that the windings are placed on the outside of a structure carrying them, for example the supporting body or the winding core. It is understood, however, that the invention can be applied also to such arrangements where the particular core of a winding is arranged on the radial outside of the winding.
In the case of the invention, if an area which is delimited in the axial direction of the winding core and which is shorter than the length of the winding and located in full within the axial length of the winding, is rigidly connected with the supporting body, whereas the remaining parts of the winding core are connected with the supporting body in a non-rigid way, a reduction in length of the supporting body, due to the axial pressures caused by the magnetic fields, can be transmitted only to that area in length where the rigid connection exists, and may there possibly lead to a reduction in length of the winding body at its radial outer surface which is in contact with the winding. This already reduces the influence which the reduction in length of the supporting body has on the winding of the superconductive wire. The shorter the area in length over which a rigid connection exists between the winding core and the supporting body, and the greater the distance between the surface of the winding core which carries the coil and the said rigid connection or fixing means, the less important is the influence of the pressure on the winding arranged on the winding core.
The invention also extends to embodiments where the winding core is rigidly connected with the supporting body via at least 2 axially spaced fixing means. It is understood that in this case the spacing between the fixing means is comprised in the before-mentioned area in length, the decisive factor for the reduction in length of the winding core being the distance between the forward and the rear ends of the single fixing means or of the foremost and the rearmost fixing means, if a plurality of such fixing means are provided.
If at least part of the area of the winding core which is fixed to the supporting body is located outside of the length of the winding, in the axial direction, then only the fixing area which is inside the length of the winding may possibly lead to a variation in length of the area of the winding core which is available for the coil. This, therefore, also reduces the influence of the pressure on the winding.
If the fixation of the winding core is located completely outside the coil, the winding on the winding core is not influenced at all by the pressure prevailing in the supporting body.
But even if the fixation is located inside the winding area, viewed in the axial direction, the influence which the pressure prevailing in the supporting body has on the winding core will be completely eliminated if, according to one embodiment of the invention, a stop extending substantially in transverse direction to the sense of the displacement to be prevented is used for fixing the winding core against displacements in the axial direction. This is because in this case the axial length of the fixation is equal to zero and the pressure prevailing in the supporting body can no longer result in a variation in length of the winding core.
The pressure building up in each winding, due to radial components of the magnetic field, cannot be eliminated by the invention. It may be of advantage, in particular for constructional reasons, to apply the invention also to one or both of the outermost coils neighboring the ends of the coil arrangement.
There is the possibility to connect the winding core with the supporting body only at the point of fixation and to leave a certain distance between the remaining parts of the winding core and the winding body. For reasons of stability, however, it may be appropriate to have the remaining parts of the winding core, which are not to be fixed on the supporting body against longitudinal displacements, also supported by the supporting body. This is effected, according to one embodiment of the invention, by an arrangement where the winding core is seated on the supporting body in a low-friction relationship. This low-friction contact, which is intended to prevent pressures from being transmitted to the winding core in an undesirable way, may be achieved in particular by a friction-reducing coating consisting of a suitable material, in particular a plastic material, applied to the supporting body and/or to the winding core, or by suitable selection of the materials used and/or by suitable surface treatment.
According to certain embodiments of the invention, the winding core may consist substantially of a part which is in contact with the said winding only at the latter's radial (radially inward or radially outward) delimitation. In this case, any possible displacement of the winding relative to the winding core must be prevented by an interference fit and/or by filling the connection with a plastic compound and/or by providing stops or in some other suitable manner. The winding core may instead form a winding chamber, i.e. may have at least one wall extending perpendicularly to the longitudinal direction of the coil and having a height at least equal to the winding thickness in the radial direction, said wall defining the winding space.
In particular in the case of those embodiments of the invention where a stop is provided which prevents any movements of the winding core, in the meaning of the invention, only in a single sense of displacement (normally towards the middle of the coil), it may be convenient or necessary to prevent any undesired displacement of the winding core in the opposite direction in order to obtain well defined assembly conditions and, in particular, to exclude undesirable movements of the winding core if the coil axis extends in the vertical direction. In such cases, it is provided according to one embodiment of the invention that the winding core is supported on the one hand by the before-mentioned stop, which can be regarded as absolutely rigid with respect to the forces generated by the radial components of the magnetic field, and on the other hand additionally by another stop which delimits the movement of the winding core in the other direction and which, although preventing any undesired displacement of the winding core, is not strong enough as to transmit pressures on the winding core that would lead to a disturbing reduction in length of the supporting body, if this stop and the first-mentioned stop should come to fix between them the full length or part of the length of the winding body. The additional stop will, therefore, be described hereafter as soft stop.
A winding lying in the center of the longitudinal extension of a magnetic coil arrangement is, generally, exposed only to extremely low radial components of the magnetic field so that such a winding is itself not exposed to high pressures that may arise inside its own winding core. Since in addition, thanks to the invention, no axial pressures are transmitted to it from other windings, it is rendered possible by the invention to structure a winding near its coil center for homogenization purposes in particular to provide it with What is known as notches, i.e. gaps or areas of reduced current density in the cross-sectional volume occupied by the winding. The term supporting body as used herein is meant to describe both hollow cylindrical supporting bodies and supporting bodies which are composed of a plurality of parallel bars extending in the axial direction in order to avoid eddy currents.
Other features and advantages of the invention will appear from the following description of certain embodiments of the invention by reference to the drawing, which shows certain details which are essential to the invention, and from the claims. It is understood that each of the features of the invention may be implemented in any embodiment of the invention either alone or in any combination thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a longitudinal section through a first embodiment comprising a superconductive magnet coil arrangement with a total of three windings;
FIG. 2 shows a similar representation of a magnet coil arrangement with a total of four windings;
FIGS. 3 to 6 show longitudinal sections through several possible arrangements where the movement of a winding core carrying a winding is limited by a stop in one direction;
FIG. 7 shows a simplified longitudinal section through another embodiment of the invention;
FIG. 8 shows a simplified longitudinal section through another embodiment of the invention; and
FIGS. 9 and 10 show modifications of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, a tubular supporting body 1 with an axis 2 can be seen with windings 4 and 5, respectively, provided on its two end portions, and a winding 6 with partial windings 6a, 6b, 6c, arranged in its central area. The windings 4 and 5 are of absolutely identical design, being wound around a winding core 10 which consists of walls extending perpendicularly to the axis 2 and a tubular connection piece and which are fixed on the supporting body 1 over their full length. The central winding 6 is wound around a winding core 12, which likewise consists of side walls and a tubular connection piece, but which is fixed on the supporting body 1 against displacement in both directions solely by its axially central area 14, over its full circumference. The length of the area 14 is so short that the winding 6 will not be influenced by the compression or shortening of this area 14 due to the pressures exerted by the windings 4 and 5 and acting in the axial direction inside the supporting body 1. The areas of the winding core 12 outside the area 14 are supported on the supporting body 1 in low-friction relationship so that the supporting body 1 is permitted at these points to move in the axial direction relative to the winding core 12. The low-friction contact is achieved by a coating 16 consisting of a low-friction plastic material which is applied upon the radial inner side of the winding core 12. As indicated in FIG. 1, the winding 6 is structured with a view to generating the most homogeneous magnetic field possible; in the illustrated example it displaces a profiled cross-section, which means that the winding height is reduced in length in the central area (partial winding 6a).
The three coils 4, 5 and 6 serve for generating a stationary magnetic field in a nuclear magnetic resonance spectrometer or a nuclear magnetic resonance tomograph. The winding system provided for generating the stationary magnetic field may contain yet other windings. In operation, the arrangement illustrated in FIG. 1 is located inside a cryostat filled with liquid helium.
The arrangement illustrated in FIG. 2 comprises a total of four windings, namely two windings 22 and 23 arranged near the ends of the supporting body, which is indicated in this case by reference numeral 21, and two windings 24 and 25 arranged at equal spacings from the windings 22 and 23, respectively, towards the axial center of the supporting body 21. The outside of the supporting body 21 is stepped in such a way as to form annular shoulders or stops 26 which prevent the windings 24 and 25, each of which is arranged on a winding core 27, from moving towards the axial center of the arrangement, i.e. towards each other, and so that additional annular shoulders or stops 29 prevent the windings 22 and 23, which are likewise arranged on winding cores 30, from moving towards each other. The windings 24 and 25 are fixed in the winding cores 27, whereas the winding cores 27 are supported on the supporting body 21 in low-friction relationship--not illustrated in the drawing--and are prevented from moving towards each other only by the stops 26. In the case of this illustrative example, the winding cores 30, too, are supported on the supporting body 21 in low-friction relationship.
The windings 22 and 23 located at the ends of the coil arrangement are, just as the windings 4 and 5 in the embodiment illustrated in FIG. 1, exposed to particularly strong radial components of the magnetic field built up by the entire coil arrangement. Due to the direct current flowing through the windings, the windings 22 and 23 tend to move towards each other, thereby producing forces at the stops 29 which lead to a certain reduction in length of the supporting body 21 which consists of aluminium. The reduction in length of the supporting body leads to an axially directed relative displacement between the radial outer surface of the supporting body 21 and the radial inner surface of the winding core 27, in the area of the winding cores 27, which relative movement is, however, not transmitted as pressure to the winding core and to the windings 24 and 25, due to the low-friction fit of the winding cores 27 on the supporting body 21. The reduction in length of the supporting body 21 only has the result that the distance of the windings 24 and 25 is somewhat reduced. This change in distance, which is also encountered in the case of the known arrangements, is taken into account already when designing the coil system.
FIGS. 3 to 6 only show the way in which a single coil is fixed on the supporting body. In these cases, any movement of the respecting winding, together with its winding core, to the right is prevented by a stop which is designed as a ring fixed on the supporting body 41.
The winding arranged in the winding core 43 in FIG. 3 is identified by reference numeral 42. A ring 46 made from aluminium is rigidly connected with the supporting body 41. The ring 46 comprises a shoulder 47 of low height, which does not, in the radial direction, extend to the beginning of the winding 42, and the winding core 43 rests against the shoulder 47 forming a stop so that it cannot move to the right. Generally, the winding core 43 does not rest against the supporting body 41, but is arranged at a radial distance therefrom.
In FIG. 4 the winding core 43 which, just as the embodiment discussed above, comprises lateral walls is provided with a friction-reducing coating 44 and is thereby supported on the supporting body 41 in low-friction relationship. In the case of the arrangement illustrated in FIG. 4, the shoulder 49 formed by the ring 48 forming the stop extends a little further in radially outward direction. In both cases (FIGS. 3 and 4) the ring 46 or 48, respectively, supports the right end portion of the winding core against radial movement towards the supporting body 41, but the rings 46 and 48 do not extend into the area of the coil 42 in axial direction.
In the case of the arrangement illustrated in FIG. 5, the ring 52 forming the stop is axially located in full inside the coil 42. The winding core 53 is provided on its radially inner side with a step 54, which is in contact with the ring 52 constituting a stop for this step 54 and, thus, for the winding core 53. At the left of the ring 52, the winding core 53 is again supported on the supporting body 41 in low-friction relationship.
In the case of the arrangement illustrated in FIG. 6, another ring 56 made from a low-friction plastic material is provided at the right of the ring 52 for supporting the winding core 57, in low-friction relationship, via the latter's area right of the ring 52.
The before-mentioned way of supporting a winding by a so-called soft stop may also be effected by rings fixed on the supporting body 41 or by stops which do not extend over the full circumference of the supporting body 41. For a winding having a weight of 1,000 kg where the before-mentioned stop, which is to prevent any axial displacement towards the coil center, has to counteract a force generated by magnetic effects in the range of, for example, 300,000N, this ring may, for example, have the following dimensions: If the supporting body 41 has an outer diameter of 120 cm, the ring has an outer diameter of 130 cm and a length in the axial direction of 10 cm, and consists of an aluminium alloy. The corresponding soft stop is formed by a total of 12 blocks fixed on the supporting body 41, which blocks are made from an aluminium alloy having a height of 1 cm, a width (measured in the circumferential direction of the supporting body 41) of 5 cm and a length in the axial direction of 10 cm. When forces generated by magnetic effects occur, these soft stops will deform sufficiently so that the pressure produced by them inside the winding core, in its longitudinal direction, is sufficiently small as not to effect any notable change in length of the winding core and, thus, any notable disturbance of the winding.
In the case of the arrangement illustrated in FIG. 7, a winding 42 is arranged radially inside the supporting body 41, but is itself wound around a coil core 60 which is arranged on the radial inside of the winding and which is connected with the supporting body via a projection 62 extending in radial outward direction.
In the case of the arrangement illustrated in FIG. 8, the coil 42 is wound inside a radially outward winding core 64 in the form of a tube which is seated in the supporting body 41 in low-friction relationship and is supported at its end facing the coil center by a ring 68 which acts as a stop.
FIG. 9 shows a modification of FIG. 4 where that lateral wall of the coil core 43', which anyway does not absorb any forces, is missing.
In all embodiments described heretofore (with the exception of FIG. 8), the lateral walls of the winding cores transmit to the respective stops of the supporting body part of the forces produced by the individual turns of the respective winding. If the winding as such is very stable in itself, for example when the gaps are filled with a suitable compound, the winding core may be designed without the lateral walls and may then consist only of a tubular part 43'', as indicated in FIG. 10 which is likewise a modification of FIG. 4. In order to reduce eddy currents, the tubular part may, just as the supporting body, be provided with recesses extending in the longitudinal direction.
Where heretofore one winding was provided only, for example the outermost winding in the axial direction, several windings may be provided according to the invention. So, it is possible to subdivide the before-mentioned outermost winding in two windings, for example, which have the same number of turns and which are arranged at a certain axial distance one from the other. According to the general principle of the invention, at least the axially inner one of these two windings is then supported only by points so as to relieve it from the pressure of the axially outer winding. In addition, the pressure arising in each winding itself is also reduced due to the smaller number of turns.
Preferably, all windings are superconductive, as in the illustrated embodiment of the invention.
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A superconductive magnet coil arrangement for generating a homogeneous magnetic field in a volume under examination, comprising a magnet coil having two first windings of a superconductive wire which are disposed adjacent the ends of the magnet coil and which are supported on a hollow supporting body, and comprising further at least one additional winding of a superconductive wire which is arranged in the area between the first windings and which is supported by the supporting body, is characterized by the fact that at least one of the additional windings is arranged on a winding core mounted on the supporting body and the fixation securing the winding against axial displacement occupies an area in length of the winding core shorter than the length of the winding arranged on the winding core. It is achieved in this manner that the pressure produced by Lorentz forces in the supporting body is kept off the rest of the winding.
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Background of Invention
[0001] 1. Field of the Invention
[0002] The Invention relates to fluorescent discharge lamps, and more particularly, to a multi-tube fluorescent discharge lamp which is constructed of multiple glass tubes of different caliber in coaxial structure, the both sides of the inner most tube are connected to a cathode respectively, by isolating, perforating and blocking the discharge path, forming successive discharge chambers, and coating fluorescent material on surface of the discharge tubes. The Invention can then have more fluorescent area than a conventional fluorescent lamp of the similar size and higher lumen as well as power transfer factor. Compared with the power consumption of a conventional fluorescent discharge lamp, the Invention therefore has higher luminous flux.
[0003] 2. Description of the Prior Art
[0004] Generally, a conventional fluorescent discharge lamp uses one straight or round tube. To minimize the size and to increase the illumination, there is a kind of compact fluorescent discharge lamp that the straight tube is bent into a wreath or U type. Alternatively, couples of short straight fluorescent tubes are aligned and connected in parallel, on the both terminations of the tube with a cathode tungsten filament that coated with oxide such as Ba, Sr and Ca. In the discharge tube is in a state of vacuum and with little Hg and Ar, which helps the discharge.
[0005] The conventional fluorescent lamp tubes is usually a round cross-section and only one layer of fluorescent material such as phosphor is coated on the surface of the tube inside. When the cathodes on both sides of the tube is started up by current and high-voltage power is applied to the cathodes on both sides of tube, the electron is released between the two cathodes and make the tube glow discharge. The Ar and Hg vapor molecules are also stimulated to create plasma; the ion and ultraviolet rays also impact the phosphor, so that the potential energy is transferred into light from the phosphor.
[0006] Because the cross-section area of a round tube is larger than that of any shape, the average density of electronic flux of the round tube inside is lower than other shape of tube. Furthermore, the electronic flux on the discharge path is concentrated nearby the axis of the discharge tube; the density of the electronic flux nearby the surface of the discharge tube inside gets lower.
[0007] Therefore, the luminous flux in a round tube can not in proportion to raise by increasing the diameter of the tube to expand the area of phosphor, much of energy nearby the axis in the discharge tube will be depleted and transfer into heat, the transferring factor of the lumen (Lm) and Watt (W) remains not high enough.
[0008] Although there is another kind of lamp which build-in a lot of segmented tubes and coated with phosphor to increase the illuminant fluorescent area, but the lamp does not forming a successive discharge path, therefore, it does not guarantee stable discharge path or equable plasma status, nor adequate and complete illumination of fluorescent layer in the discharge tube, because the discharge path proceeds in the shortest distance.
[0009] Moreover, due to the narrow spectrum of conventional fluorescent discharge lamp, the color-rendering index (Ra) is low and the color temperature (K) is high which therefore causes the illuminated object unable to reveal its colors. Besides, for the cathode on both sides of the conventional fluorescent discharge lamp is hit by electron, the tungsten filament is then vaporized to be black and pollutes the fluorescent layer of the tube, hence reduces the illumination efficiency of the fluorescent layer as well as the life cycle of the fluorescent discharge lamp.
SUMMARY OF INVENTION
[0010] This Invention is a multi-tube fluorescent discharge lamp; the design concept of the Invention is constructed of multiple discharge glass tubes of different caliber in coaxial structure. By isolating, perforating and blocking the discharge path, and applying phosphor on surface of the discharge tubes, a thin and transparent film of fluorescent coating is then created, allowing the light of the inner tubes pass through each of the coatings to the outside of the lamp. In addition, a pair of cathodes as hot or cold cathode helps the electronic flux in the vacuum to be accelerated and hit the Hg molecule, which is then stimulated to create plasma. The coating of fluorescent on the inner layer surface of the discharge tube is impacted by electron ion and UV rays and then to emits light. Under the same power rate and with the same volume of lamp, the tubes of the multi-tube fluorescent discharge lamp aligned in coaxial structure have smaller cross-section area than that of conventional fluorescent discharge lamp so that this Invention can allow higher density of electron flux to pass through the discharge path in the tubes. Therefore, the high-density electron ion has better stimulating effects on the fluorescent coating and the illuminant fluorescent area is larger than conventional fluorescent discharge lamp, both advantages increasing the luminous flux.
[0011] Compared to conventional fluorescent discharge lamp of the same power rate, this Invention is characterized by higher luminance, lower consumption of electric power and lower heat rate. Moreover, because the electric flux of the Invention is less than that of conventional fluorescent discharge lamp, the vaporization caused by electric flux hitting the cathode gets slower and the life cycle of the cathode is longer accordingly than that of conventional fluorescent discharge lamp. It is also feasible to apply ringed cathode to increase the surface area of the hitting of electron flux and then disperse the hitting, so that the oxide material on the surface of the cathode can be protected from rapid consumption. By this way, the multi-tube fluorescent discharge lamp can outlive conventional fluorescent discharge lamp.
[0012] The multi-tube fluorescent discharge lamp whose surface is coated with various fluorescent material of different colors temperature. The fluorescent material, being stimulated, can release fluorescence of different spectrum and create special colors after mixing. Alternatively it can include wider spectrum to improve the color temperature (K) as well as color-rendering index (Ra) to be close to the sun spectrum.
[0013] The multi-tube fluorescent discharge lamp is designed in coaxial structure, aiming to achieve special colorful luminance or balanced spectrum range of light by way of filtering the luminance released from the transparent discharge glass tube of different colors.
[0014] The characteristics of this Invention can be specifically presented by the following detailed figures.
BRIEF DESCRIPTION OF DRAWINGS
[0015] [0015]FIG. 1 is a partly broken side view of a conventional fluorescent discharge lamp.
[0016] [0016]FIG. 2 to FIG. 9 are cross-sectional views and end views showing a step-by-step process of fabrication of a three-tube fluorescent discharge lamp of a first embodiment.
[0017] [0017]FIG. 10 is a cross-sectional view and end view of the five-tube combination with phosphor of a second embodiment.
[0018] [0018]FIG. 11 is a cross-sectional view and end view of an electrode portion with a straight cathode.
[0019] [0019]FIG. 12 is a cross-sectional view and end view of an electrode portion with a ring cathode.
[0020] [0020]FIG. 13 is a cross-sectional view and end view of a cap.
[0021] [0021]FIG. 14 is a cross-sectional view and end view of a cap combined an electrode portion with a straight cathode.
[0022] [0022]FIG. 15 is a cross-sectional view and end view of a cap combined an electrode portion with a ring cathode.
[0023] [0023]FIG. 16 and FIG. 17 are cross-sectional view to follow the FIG. 9 showing a step-by-step process of fabrication of the three-tube fluorescent discharge lamp of the first embodiment.
[0024] [0024]FIG. 18 is a cross-sectional view of a three-tube fluorescent discharge lamp of a third embodiment.
[0025] [0025]FIG. 19 is a cross-sectional view of a dual-tube fluorescent discharge lamp of a fourth embodiment.
[0026] [0026]FIG. 20 is a cross-sectional view showing a five-tube portion and a pair of electrode portions of the five-tube fluorescent discharge lamp of the second embodiment.
[0027] [0027]FIG. 21 is a cross-sectional view of the three-tube fluorescent discharge lamp of the first embodiment showing a pair of bases unattached.
[0028] [0028]FIG. 22 is a cross-sectional view of the full schematic three-tube fluorescent discharge lamp of the first embodiment.
[0029] [0029]FIG. 23 is a cross-sectional view of the full schematic five-tube fluorescent discharge lamp of the second embodiment.
[0030] [0030]FIG. 24 is a partly broken and cross-sectional view of the full schematic three-tube fluorescent discharge lamp of the first embodiment.
[0031] [0031]FIG. 25 is a partly broken and cross-sectional view of the full schematic five-tube fluorescent discharge lamp of the second embodiment.
DETAILED DESCRIPTION
[0032] According to FIG. 1, illustrates a conventional fluorescent discharge lamp.
[0033] The discharge tube 8 is a straight glass tube, on both sides of the tube are the cathodes 26 whose electrode 28 are connected to the terminal 42 of the tube base 40 . The figure explains clearly that there is only one phosphor layer 18 on the surface of the tube inside. In addition, because the density of electronic flux nearby the axis of the discharge tube is higher than that the electronic flux nearby the phosphor layer 18 of the discharge tube inside. Therefore, much of energy nearby the axis in the discharge tube will be depleted and transfer into heat, the power transfer factor of the lumen needs to be improved.
[0034] According to FIG. 2, the first tube 10 is a round straight glass tube, which is the inner most tube in the multi-tube fluorescent discharge lamp and are where the cathodes 26 located.
[0035] According to FIG. 3, to use as a flame of gas and oxygen or arc heating around the circumference in the vicinity of the middle of the first tube 10 for softening and is rotated in the reverse direction around both ends of the tube, and is twisted at the softening place thus fusing into an isolator 12 to seal the pipeline nearby the middle of the tube to insulate and separating the discharge path of the first tube into two discharge chambers.
[0036] According to FIG. 4, blowing the air in from both ends of the first tube 10 , also heating is performed nearby both ends of isolator 12 on the two circumferences at the position of plural number thus the through-hole 14 of plural number are formed.
[0037] According to FIG. 5, the second tube 16 is a round straight glass tube of which the diameter is slightly larger than that of the first tube 10 , at one end of the second tube 16 is air tight and the air is blown in from another end, or air is blown in from both ends, also heating is performed nearby both ends on the two circumferences at the position of plural number thus the through-hole 14 of plural number are formed.
[0038] According to FIG. 6, the first tube 10 , after passing through the holes, is slid into the second tube 16 in coaxial structure then heating on the circumference of the second tube 16 correspond to the position of isolator 12 of the first tube 10 , also, rotation is made with reverse direction at both ends of the second tube 16 , and is twisted at the softening place of the tube thus fusing into another isolator 12 with the first tube 10 to seal the pipeline of the second tube 16 and separating the discharge path of the second tube 16 into two discharge chambers.
[0039] According to FIG. 7, phosphor layer 18 is coated on the inner and outer layer surface of the first tube 10 and the second tube 16 .
[0040] According to FIG. 8, the third tube 20 is a round straight glass tube of which the diameter is slightly larger than that of the second tube 16 , the phosphor layer 18 is coated on the inner layer surface of the third tube 20 .
[0041] According to FIG. 9, this combination of the first tube 10 and the second tube 16 can be slid into the third tube 20 in coaxial structure.
[0042] According to FIG. 10 and refer to the FIG. 6, just as the combination of the first tube 10 and the second tube 16 to be slid into the third tube 20 in coaxial structure that the diameter of the third tube 20 which is slightly larger than that of the second tube 16 , heating is performed on the circumference of the third tube 20 correspond to the isolator 12 of the second tube 16 , also, rotation is made with reverse direction at both ends of the third tube 20 and is twisted at the softening place of the third tube 20 for fusing with the isolator 12 of the second tube 16 , then to connect and form an isolator 12 of the third tube 20 to seal the pipeline of the third tube 20 and separate the discharge path of the third tube 20 , to allow the air being blown in at both ends of the third tube 20 , also, heating shall be performed on the circumference at both ends of 20 to approach the isolator 12 of the second tube 16 at the position of plural number thus the through-hole 14 with plural number are formed.
[0043] Also, with a glass tube of the fourth tube 22 , which the diameter is slightly larger than that of the third tube 20 , to slide into the combination of the first tube 10 , the second tube 16 , and the third tube 20 into the fourth tube 22 in coaxial structure, heating on the circumference of the fourth tube 22 approach to the isolator 12 of the third tube 20 , at both ends of said the fourth tube 22 is rotated in reverse direction, and twisted at the softening place of the fourth tube 22 for fusing with the isolator 12 of the third tube 20 for connecting and forming an isolator 12 of the fourth tube 22 to seal the pipeline of the fourth tube 22 , separating the discharge path of the fourth tube 22 , thus forming two discharge chambers so that air can be blown in from both ends of the fourth tube 22 , also, heating is performed on the circumference to approach both ends of the fourth tube 22 and at the position of plural number, thus extruding through-holes 14 with plural number.
[0044] The phosphor layer 18 is formed at the inner and outer layer surface of the combination of the first tube 10 , the second tube 16 , the third tube 20 and the fourth tube 22 , also formed at the inner layer surface of the fifth tube 24 . This connected combination of the first tube 10 , the second tube 16 , the third tube 20 and the fourth tube 22 shall be slid into the fifth tube 24 in coaxial structure.
[0045] According to FIG. 11, one stem 34 is a conical glass post, one of its ends with smaller diameter can seal and fix the plural electrode 28 which is connected with a straight form cathode 26 , one pipe 32 is connected with the sealed end of the fixed plural electrode 28 , its opening hole 30 is located the sealed end and communicated with pipe 32 .
[0046] According to FIG. 12, and refer to the FIG. 11, the electrodes 28 which is connected with a ring cathode 38 .
[0047] According to FIG. 13, a cap 36 its inner diameter is same as the outer diameter of the first tube 10 , the outer diameter of cap 36 is the same as the diameter of the outer most discharge tube.
[0048] According to FIG. 14, the structure of stem is same as FIG. 11 above, however, for the conical glass post, the larger end is connected with a cap 36 , the outer diameter of said the cap 36 is the same as the diameter of the outer most tube of the multi-tube fluorescent discharge lamp.
[0049] According to FIG. 15 and refer to the FIG. 14, the structure same as FIG. 14, however, its electrodes 28 is connected with a ring cathode 38 .
[0050] According to FIG. 16 and refer to the FIG. 9, also including plural number stem 34 , said stem 34 includes a cathode 26 , plural electrode 28 , and connects with a cap 36 , said cathode 26 is assembled in the two discharge chamber of the first tube 10 respectively, the outer diameter of the cap 36 is the same as that of the third tube 20 .
[0051] According to FIG. 17 and refer to the FIG. 16, the cathode 26 of plural number stem 34 are slid into the two discharge chambers of the first tube 10 respectively, heating at the outskirts of the circumference at both ends of all the tubes, melting and sealing both ends of the tubes.
[0052] Or use the cathode 26 of plural number stem 34 with cap 36 is slid into the two discharge chambers of the first tube 10 respectively, heating on the circumferences of cap 36 correspond to the both ends of all the tubes, and at both ends of all the tubes can be melted and sealed. Due to the sealing of both ends of all discharge tubes and isolator 12 and through-hole 14 of the first tube 10 and the second tube 16 , thus, forming successive discharge chambers.
[0053] According to FIG. 18, the first tube 10 is a round straight glass tube, in which a pair of electrodes 28 and one pipe 32 with said tube are slid in coaxial structure, and heating at one end of the tube for softening, by means of clamping, pressing and sealing the tube, the pair of electrodes 28 and pipe 32 can be fixed, air is blown into the pipe 32 , by means of the heating at the end of sealed, a hole 30 can be extruded, forming a phosphor layer 18 on the surface of said tube outside, install cathode 26 in the pair of electrode 28 , and the other first tube 10 can be completed with the method mentioned above.
[0054] The second tube 16 is a round straight glass tube, its diameter is slightly larger than that of the first tube 10 , the air is blown in at both ends of the second tube 16 , or one end of said tube is air tight and the air is blown in from another end, also, heating is performed on the circumferences to approach both ends of the second tube 16 , at the position of plural number thus extruding the through-hole 14 with plural number, and heating is also performed at the circumference to approach the middle of the second tube 16 , rotated with reverse direction at both ends of the second tube, and is twisted at the softening place of the tube thus fusing into an isolator 12 to seal the path of the discharge tube and separate the discharge path of the second tube 16 .
[0055] The third tube 20 is a round straight glass tube, its diameter is slightly larger than that of the second tube 16 , the phosphor layer 18 is formed in the inner layer surface of the third tube 20 and in the inner and outer layer surface of the second tube 16 .
[0056] The two cathodes 26 of the first tubes 10 can be slid into the two-discharge chamber of the second tube 16 in coaxial structure respectively, that the cathodes 26 installed oppositely to approach the isolator 12 , heating at the outskirts of the circumference at both ends of the first tube 10 and the second tube 16 , sealing both ends of the tubes, then slid into the third tube 20 in coaxial structure, heating at the outskirts of the circumference at both ends of the second tube 16 and the third tube 20 , sealing both ends of all discharge tubes. Due to the sealing of both ends of all discharge tubes and isolator 12 and through-hole 14 of the second tube 16 , thus, forming successive discharge chambers.
[0057] As mentioned above, heating at the outskirts of the circumference at both ends of the first tube 10 , the second tube 16 , the third tube 20 can make it soft and melt and seal both ends of all discharge tubes, also, a cap 36 can be placed at both ends of the multi-tube, after the cap 36 on the circumferences correspond to the both ends of all discharge tubes is heated, both ends of the first tube 10 , the second tube 16 , the third tube 20 can be melted and sealed, thus, forming successive discharge chambers.
[0058] For the multi-tube fluorescent discharge lamp with more than S tubes, which can be formed by means of the method mentioned above with the total tube number N (N=odd number), tube number of different tube with different diameter, the isolator 12 can be formed from the second tube 16 to the (N−1)th tube to approach the middle of the tubes. The through-hole 14 with plural number can be formed at the even number tube and from the second tube 16 to the (N−1)th tube to approach the both ends of the tubes at the position of circumference, the through-hole 14 with plural number can be formed at the odd number tube from third tube 20 to (N−2)th tube to approach the both ends of the isolator 12 at the position of circumference.
[0059] The phosphor layer 18 coated on the inner and outer layer surface of the tube from the second tube 16 to the (N-1)th tube, and coated on the outer layer surface of the tube on the first tube 10 , and coated on the inner layer surface of the Nth tube, a pair of electrode 28 of the cathode 26 connecting to terminal 42 of base 40 respectively.
[0060] According to FIG. 19, the first tube 10 is a round straight glass tube, heating is performed at the circumference to approach the middle of the first tube 10 , and rotation is made with reverse direction at both ends of the first tube 10 , and is twisted at the softening place of the tube thus fusing into an isolator 12 to seal the pipeline of the first tube 10 , thus, forming two discharge chambers, and air is blown in from both ends of said tube and heating is performed at the circumferences approach to the both ends, at the position of plural number to extrude the through-hole 14 with plural number, forming the phosphor layer 18 on the inner and outer layer surface of said tube.
[0061] A second tube 16 is a round straight glass tube of which the diameter is slightly larger than that of the first tube 10 , the phosphor layer 18 is coated on the inner layer surface of the second tube 16 , then the first tube 10 be slid into the second tube 16 in coaxial structure, also, plural number stem 34 , said stem 34 includes a cathode 26 , a pair of electrode 28 , a hole 30 , a pipe 32 , its plural number cathode 26 is placed in the two discharge chambers of the first tube 10 .
[0062] Heating is performed at the outskirts of circumference at both ends of the first tube 10 and the second tube 16 to melt and seal both ends of the first tube 10 and the second tube 16 with the stem 34 , due to the isolator 12 and the through-hole 14 of the first tube 10 , and the sealing of both ends of all discharge tubes, thus, forming successive discharge chambers.
[0063] For the multi-tube fluorescent discharge lamp with 4 tubes or more than 4 tubes, which can be formed by means of the method mentioned above with the total tube number N (N=even number), tube number of different tube with different diameter, the isolator 12 can be formed from the first tube 10 to the (N−1)th tube to approach the middle of the tubes. The through-hole 14 with plural number can be formed at the odd number tube and from the first tube 10 to the (N−1)th tube to approach the both ends of the tubes at the position of circumference, the through-hole 14 with plural number can be formed at the even number tube from the second tube 16 to (N−2)th tube to approach the both ends of the isolator 12 at the position of circumference, also, with one cap 36 or the stem 34 connecting a cap 36 at both ends of the multi-tube to heat the cap 36 at the circumferences of both ends of the corresponding discharge tubes, both ends of all tubes can be melted and sealed, the phosphor layer 18 coated on the inner and outer layer surface of the tube from the second tube 16 to the (N−1)th tube, and coated on the outer layer surface of the first tube 10 , and coated on the inner layer surface of the Nth tube, a pair of electrode 28 of the cathode 26 connecting to terminal 42 of base 40 respectively.
[0064] According to FIG. 20 and refer to the FIG. 10, also including plural number stem 34 , said stem 34 includes a cathode 26 , a pair of electrode 28 , and connects with one cap 36 , said cathode 26 is assembled in the two discharge chambers of 10 , the outer diameter of the cap 36 is the same as that of the third tube 20 . The cathode 26 of plural number stem 34 is assembled in the two discharge chambers of the first tube 10 respectively, heating is performed at the outskirts of the circumference correspond to the both end of all tubes, its softening can melt and seal both ends of all tubes or plural number stem 34 connecting with cap 36 placed at both ends of the first tube 10 , the second tube 16 , the third tube 20 , the fourth tube 22 and the fifth tube 24 , heating on the corresponding position at the circumference of all discharge tubes of the two cape 36 can seal both ends of all tubes. Due to the isolator 12 , the through-hole 14 and sealing of both ends of all discharge tubes, thus, forming successive discharge chambers.
[0065] For the multi-tube fluorescent discharge lamp with more than 5 tubes, which can be formed by means of the method mentioned above with the total tube number N (N=odd number), tube number of different tube with different diameter, the isolator 12 can be formed from the first tube 10 to the (N−1)th tube to approach the middle of the tubes. The through-hole 14 with plural number can be formed at the even number tube and from the second tube 16 to the (N−1)th tube to approach the both ends of the tubes at the position of circumference, the through-hole 14 with plural number can be formed at the odd number tube from the first tube 10 to the (N−2)th tube to approach the both ends of the isolator 12 at the position of circumference, the phosphor layer 18 coated on the inner and outer layer surface of the tube form the first tube 10 to the (N−1)th tube, and the inner layer surface of the Nth tube, a pair of electrode 28 of the cathode 26 connecting to terminal 42 of base 40 respectively.
[0066] According to FIG. 21 and refer to the FIG. 17, one base 40 with a pair of terminal 42 at both ends of the three-tube fluorescent discharge lamp, the electrode 28 of the cathode welded on said terminal 42 respectively.
[0067] According to FIG. 22, when negative HV presents at one of those electrode 26 in the first discharge tube 10 , electrons released by its electrode are attracted by positive HV at another electrode 26 in another first discharge tube 10 , for moving into second discharge tube 16 from through-hole 14 of the first discharge tube 10 , via the third discharge tube 20 from through-hole 14 of the second discharge tube 16 ; electrons passing through the third discharge tube 20 enter into another end of second discharge tube 16 from through-hole 14 thereof, and into another end of the first discharge tube 10 from through-hole 14 thereof, then the electrons hit another electrode 26 ; the electrode 26 with positive charges are converted into negative charges during the next half cycle of the alternating current, with negative charges in said another end of discharge tube 10 , to release the electrons traveling in reverse along the route of electron movement of the first half cycle to repeat the process upon arriving at the corresponding electrode 26 with positive charges during which electronic irons and ultraviolet excited by the discharge chamber of each discharge tube, the phosphor on the surface of each discharge tube will be impacted and to emit light.
[0068] According to FIG. 23, when negative HV presents at one of those electrode 26 in the first discharge tube 10 , electrons released by its electrode are attracted by positive HV at another electrode 26 in another first discharge tube 10 , for moving into second discharge tube 16 from through-hole 14 of the first discharge tube 10 , via the third discharge tube 20 from through-hole 14 of the second discharge tube 16 , then fourth discharge tube 22 from through-hole 14 of the third discharge tube 20 and finally into the fifth discharge tube 24 from through-hole 14 of fourth discharge tube 22 ; electrons passing through the fifth discharge tube 24 enter into another end of fourth discharge tube 22 from through-hole 14 thereof, then into another end of third discharge tube 20 from through-hole 14 thereof and into another end of second discharge tube 16 from through-hole 14 thereof reaching another end of the first discharge tube 10 from through-hole 14 thereof, then the electrons hit another electrode 26 ; the electrode 26 with positive charges are converted into negative charges during the next half cycle of the alternating current, with negative charges in said another end of discharge tube 10 , to release the electrons traveling in reverse along the route of electron movement of the first half cycle to repeat the process upon arriving at the corresponding electrode 26 with positive charges during which electronic irons and ultraviolet excited by the discharge chamber of each discharge tube, the phosphor on the surface of each discharge tube will be impacted and to emit light.
[0069] According to FIG. 24, at the related positions between all discharge tubes, the isolator 12 formed at the first tube and second tube to approach the middle of these tubes, the cathode 26 is located in the discharge chambers of the first tube 10 respectively. Forming through-hole 14 with plural number at the circumference to approach the both ends of the isolator 12 of the first tube 10 , forming through-hole 14 with plural number at the circumference to approach the both ends of the second tube 16 . The phosphor layer 18 coated on the inner and outer layer surface of the first tube 10 , the second tube 16 and the inner layer surface of the third tube 20 , a pair of electrode 28 of the cathode 26 connecting to terminal 42 of base 40 respectively.
[0070] According to FIG. 25, at the related positions between all discharge tubes, the isolator 12 formed at the first tube 10 , the second tube 16 , the third tube 20 and fourth tube 22 to approach the middle of these tubes, the cathode 26 is located in the discharge chambers of the first tube 10 respectively. Forming through-hole 14 with plural number at the circumference to approach the both ends of the isolator 12 of the first tube 10 and the third tube 20 , forming through-hole 14 with plural number at the circumference to approach the both ends of forming through-hole 14 with plural number the second tube 16 and fourth tube 22 . The phosphor layer 18 coated on the inner and outer layer surface of the first tube 10 , the second tube 16 , the third tube 20 , the fourth tube 22 , and the inner layer surface of the fifth tube 24 , a pair of electrode 28 of the cathode 26 connecting to terminal 42 of base 40 respectively.
[0071] Subsequently, Heating on outside of the combination of tubes; meanwhile, blowing in dry air from one of the pipe 32 and exhausted from the other pipe 23 , to accelerate drying the phosphor layers. After the drying process completed, one of the pipe 23 is heated and sealed, then several mg of mercury (Hg) is injected into the discharge chamber from the opening pipe 32 , then the discharge chamber is vacuumed and then filled with little of Ar gas such as several hundreds Pa in pressure, and then sealing the pipe 23 . Afterward the combination of tubes is put in an environment of electromagnetic field such as microwave chamber to agitate the liquid Hg into vapor Hg, applying current and high voltage on the both cathodes, a glow discharge will be generated in the discharge lamp.
[0072] It will be now apparent to those skilled in the art that other embodiments, details and uses can be made consistent with the letter and spirit of the foregoing disclosure and within the scope of this patent, which is limited only by the following claims, construed in accordance with the patent law, including the doctrine of equivalents.
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A multi-tube fluorescent discharge lamp, which is constructed of multiple glass tubes of different caliber in coaxial structure, the both sides of the inner most tube are connected to a cathode respectively, by isolating, perforating and blocking the discharge path, forming a successive discharge path, and coating phosphor on surface of the discharge tubes. The Invention can then have more fluorescent area than a conventional fluorescent lamp of the similar size and higher lumen as well as power transfer factor. Compared with the power consumption of a conventional fluorescent discharge lamp, the Invention therefore has higher luminous flux.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims priority from Japanese Patent Application No. 2013-074369 filed Mar. 29, 2013. The entire content of the priority application is incorporated herein by reference.
TECHNICAL FIELD
The present invention relates to a fixing device that thermally fixes a transferred developing agent image to a sheet.
BACKGROUND
Japanese Patent No. 3817482 discloses a fixing device that includes an endless belt, a nip member disposed at an internal space of the endless belt, and a pressure roller that opposes the nip member so as to interpose the endless belt between the pressure roller and the nip member. More specifically, the nip member is subjected to machining to have a convex surface in contact with the endless belt and having a central portion and end portions in an axial direction of the endless belt. The central portion has a protruding amount protruding toward the pressure roller greater than that of the end portions. In this way, wrinkling of recording sheets can be prevented.
SUMMARY
However, with the conventional technology, the protruding amount of the central portion of the nip member must be directly adjusted by machining the surface of the nip member to be in contact with the endless belt. Here, accurate machining is troublesome, and dimensional error may occur in the amount of protrusion.
In view of the foregoing, it is an object of the present invention to provide a fixing device capable of reducing dimensional error in the protrusion amount of the central portion of the nip member.
In order to attain the above and other objects, the present invention provides a fixing device that may include a nip member, an endless belt, a rotating member, and a stay. The endless belt may have an inner peripheral surface and an outer peripheral surface. The inner peripheral surface may be configured to be in sliding contact with the nip member in a sliding direction. The rotating member may be configured to nip the endless belt in cooperation with the nip member, and may be configured to constitute a nip region between the endless belt and the rotating member. The rotating member may have an axis defining an axial direction. The stay may be disposed opposite to the nip region with respect to the nip member and may have a first supporting face configured to support the nip member and a second supporting face configured to support the nip member. The second supporting face may be spaced apart from the first supporting face in the sliding direction and may be disposed downstream of the first supporting face in the sliding direction. The first supporting face may have a first upstream edge and a first downstream edge positioned downstream of the first upstream edge in the sliding direction. The first downstream edge may have one side portion as a first portion, another side portion as a third portion, and a central portion as a second portion in the axial direction. The first portion may be positioned opposite to the third portion in the axial direction. The second portion may be positioned between the first portion and the third portion. The second supporting face may have a second upstream edge and a second downstream edge positioned downstream of the second upstream edge in the sliding direction. The second downstream edge may have one side portion as a fourth portion, another side portion as a sixth portion, and a central portion as a fifth portion in the axial direction. The fourth portion may be positioned opposite to the sixth portion in the axial direction. The fifth portion may be positioned between the fourth portion and the sixth portion. The second portion and the fifth portion may define a first distance therebetween in the sliding direction. The first portion and the fourth portion may define a second distance therebetween in the sliding direction. The third portion and the sixth portion may define a third distance therebetween in the sliding direction. The second distance and the third distance may be longer than the first distance.
The present invention further provides a fixing device that may include a nip member, an endless belt, a rotating member, and a stay. The endless belt may have an inner peripheral surface and an outer peripheral surface. The inner peripheral surface may be configured to be in sliding contact with the nip member in a sliding direction. The rotating member may be configured to nip the endless belt in cooperation with the nip member, and may be configured to constitute a nip region between the endless belt and the rotating member. The rotating member may have an axis defining an axial direction. The stay may have a first supporting face configured to support the nip member and a second supporting face configured to support the nip member. The second supporting face may be spaced apart from the first supporting face in the sliding direction and may be disposed downstream of the first supporting face in the sliding direction. The first supporting face may have a first upstream edge and a first downstream edge positioned downstream of the first upstream edge in the sliding direction. The first downstream edge may have one side portion as a first portion, another side portion as a third portion, and a central portion as a second portion in the axial direction. The first portion may be positioned opposite to the third portion in the axial direction. The second portion may be positioned between the first portion and the third portion. The second supporting face may have a second upstream edge and a second downstream edge positioned downstream of the second upstream edge in the sliding direction. The second downstream edge may have one side portion as a fourth portion, another side portion as a sixth portion, and a central portion as a fifth portion in the axial direction. The fourth portion may be positioned opposite to the sixth portion in the axial direction. The fifth portion may be positioned between the fourth portion and the sixth portion. The second portion and the fifth portion may define a first distance therebetween in the sliding direction. The first portion and the fourth portion may define a second distance therebetween in the sliding direction. The second distance may be longer than the first distance.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a schematic cross-sectional view showing a structure of a laser printer having a fixing device according to one embodiment of the present invention;
FIG. 2 is a cross-sectional view of the fixing device;
FIG. 3 is an exploded perspective view showing a halogen lamp, a nip plate, a reflection plate, a pressure roller, and a stay;
FIG. 4A is a bottom view showing each position of a first supporting surface and a second supporting surface;
FIG. 4B is a cross sectional view taken along line I-I of FIG. 4A ;
FIG. 4C is a cross sectional view taken along line II-II of FIG. 4A ;
FIG. 4D is a cross sectional view taken along line III-III of FIG. 4A ;
FIG. 5 shows a stay according to a first modification of the present invention;
FIG. 6 shows a stay according to a second modification of the present invention;
FIGS. 7A and 7B show an end portion of a stay according to a third modification of the present invention; and
FIG. 7C shows a center portion of the stay according to the third modification of the present invention.
DETAILED DESCRIPTION
A general structure of a laser printer as an image forming device according to one embodiment of the present invention will be described with reference to FIG. 1 . A laser printer 1 shown in FIG. 1 is provided with a fixing device 100 according to the embodiment of the present invention. A detailed structure of the fixing device 100 will be described later while referring to FIGS. 2 to 4D .
<General Structure of Laser Printer>
As shown in FIG. 1 , the laser printer 1 includes a main frame 2 . Within the main frame 2 , a sheet supply unit 3 for supplying a sheet P, an exposure unit 4 , a process cartridge 5 for transferring a toner image (developing agent image) on the sheet P, and the fixing device 100 for thermally fixing the toner image onto the sheet P are provided.
Throughout the specification, the terms “above”, “below”, “right”, “left”, “front”, “rear” will be used assuming that the laser printer 1 is disposed in an orientation in which it is intended to be used. More specifically, in FIG. 1 , a left side and a right side of the figure are a rear side and a front side of the printer, respectively.
The sheet supply unit 3 is disposed at a lower portion of the main frame 2 . The sheet supply unit 3 includes a sheet supply tray 31 for accommodating the sheet P, a lifter plate 32 for lifting up a front side of the sheet P, a sheet supply roller 33 , a sheet supply pad 34 , paper dust removing rollers 35 and 36 , and registration rollers 37 . Each sheet P accommodated in the sheet supply tray 31 is directed upward to the sheet supply roller 33 by the lifter plate 32 , separated by the sheet supply roller 33 and the sheet supply pad 34 , and conveyed toward the process cartridge 5 passing through the paper dust removing rollers 35 and 36 , and the registration rollers 37 .
The exposure unit 4 is disposed at an upper portion of the main frame 2 . The exposure unit 4 includes a laser emission unit (not shown), a polygon mirror 41 , lenses 42 and 43 , and reflection mirrors 44 , 45 and 46 . In the exposure unit 4 , the laser emission unit is adapted to project a laser beam based on image data so that the laser beam is deflected by or passes through the polygon mirror 41 , the lens 42 , the reflection mirrors 44 and 45 , the lens 43 , and the reflection mirror 46 in this order. A surface of a photosensitive drum 61 is subjected to high speed scan of the laser beam.
The process cartridge 5 is disposed below the exposure unit 4 . The process cartridge 5 is detachable or attachable relative to the main frame 2 through a front opening defined by the front cover 21 at an open position. The process cartridge 5 includes a drum unit 6 and a developing unit 7 .
The drum unit 6 includes the photosensitive drum 61 , a charger 62 , and a transfer roller 63 . The developing unit 7 is detachably mounted to the drum unit 6 . The developing unit 7 includes a developing roller 71 , a toner supply roller 72 , a doctor blade 73 for regulating toner thickness, and a toner accommodating portion 74 in which toner is accommodated.
In the process cartridge 5 , after the surface of the photosensitive drum 61 has been uniformly charged by the charger 62 , the surface is subjected to high speed scan of the laser beam from the exposure unit 4 . An electrostatic latent image based on the image data is thereby formed on the surface of the photosensitive drum 61 . The toner accommodated in the toner accommodating portion 74 is supplied to the developing roller 71 via the toner supply roller 72 . The toner is conveyed between the developing roller 71 and the doctor blade 73 so as to be deposited on the developing roller 71 as a thin layer having a uniform thickness.
The toner deposited on the developing roller 71 is supplied to the electrostatic latent image formed on the photosensitive drum 61 . Hence, a visible toner image corresponding to the electrostatic latent image is formed on the photosensitive drum 61 . Then, the sheet P is conveyed between the photosensitive drum 61 and the transfer roller 63 , so that the toner image formed on the photosensitive drum 61 is transferred onto the sheet P.
The fixing device 100 is disposed rearward of the process cartridge 5 . The toner image (toner) transferred onto the sheet P is thermally fixed on the sheet P while the sheet P passes through the fixing device 100 . The sheet P on which the toner image is thermally fixed is conveyed by conveying rollers 23 and 24 so as to be discharged on a discharge tray 22 .
<Detailed Structure of Fixing Device>
As shown in FIGS. 2 and 3 , the fixing device 100 includes a fusing belt 110 , a halogen lamp 120 , a nip plate 130 , a reflection plate 140 , a pressure roller 150 , and a stay 160 . In FIG. 3 , for the sake of convenience a length of the pressure roller 150 in a leftward/rightward direction is shown as being shorter than that of the nip plate 130 , but in actuality the length of the pressure roller 150 in the leftward/rightward direction is approximately the same as that of the nip plate 130 . (See FIG. 4D .)
The fusing belt 110 is a heat-resistant and flexible endless belt. The fusing belt 110 has a metallic tube and a fluorocarbon resin layer coated thereover. The metallic tube is made from stainless steel. The fusing belt 110 has an inner peripheral surface 111 in sliding contact with the nip plate 130 , and an outer peripheral surface 112 in sliding contact with the pressure roller 150 .
The inner peripheral surface 111 is in sliding contact with the nip member and runs rearward relative to the nip plate 130 . Here, the sliding contact direction of the inner peripheral surface 111 relative to the nip plate 130 refers to an average direction in which the inner peripheral surface 111 is in sliding contact with any points of the nip plate 130 in the frontward/rearward direction. In this embodiment, the sliding contact direction refers to a direction extending in the frontward/rearward direction in FIG. 2 . In other words, the sliding contact direction refers to a direction that extends from an upstream end to a downstream end of a nip region NP relative to a rotation direction of the pressure roller 150 .
As a modification to the fusing belt 110 , a rubber layer can be provided between the metallic tube and the fluorocarbon resin layer.
The halogen lamp 120 is a heater to generate a radiant heat to heat the nip plate 130 and the fusing belt 110 for heating toner on the sheet S. The halogen lamp 120 is positioned at the internal space of the fusing belt 110 such that the halogen lamp 120 is spaced away from the inner peripheral surface of the fusing belt 110 as well as an inner (upper) surface of the nip plate 130 by a predetermined distance.
The nip plate 130 is an elongated member extending in the leftward/rightward direction, and is formed into a substantially plate-like shape. The nip plate 130 is disposed to be in sliding contact with the inner peripheral surface 111 of the tubular fusing belt 110 . The nip plate 130 is adapted to transfer the radiant heat received from the halogen lamp 120 and onto the toner on the sheet P through the fusing belt 110 .
This nip plate 130 is formed into a planar shape and is made from a metal, for example, aluminum, so as to have a thermal conductivity higher than that of a stay 160 made from a steel (described later). This nip plate 130 has a thickness permitting bending deformation thereof. The surface of the nip plate 130 that is in contact with the inner peripheral surface 111 of the fusing belt 110 can be coated with, for example, a metal oxide film or a fluororesin layer. Moreover, the thickness of the nip plate 130 can be ranging from 0.1 to 3.0 mm, or 0.3 to 2.0 mm, or 0.1 to 1.0 mm.
The reflection plate 140 is adapted to reflect radiant heat from the halogen lamp 120 toward the nip plate 130 . As shown in FIG. 2 , the reflection plate 140 is positioned within the fusing belt 110 and surrounds the halogen lamp 120 , with a predetermined distance therefrom. Thus, radiant heat from the halogen lamp 120 can be efficiently concentrated onto the nip plate 130 to promptly heat the nip plate 130 and the fusing belt 110 .
The reflection plate 140 is configured into substantially U-shape in cross-section and is made from a material such as aluminum having high reflection ratio for infrared rays or far infrared rays. The reflection plate 140 has substantially a U-shaped reflection portion 141 and a flange portion 142 extending outward from each end portion of the reflection portion 141 in the frontward/rearward direction. A mirror surface finishing is applicable on the surface of the aluminum reflection plate 140 for specular reflection in order to enhance heat reflection ratio.
The pressure roller 150 is an elastically deformable member. The pressure roller 150 is disposed downward of the nip plate 130 to vertically oppose the outer peripheral surface 112 of the fusing belt 110 . The pressure roller 150 is rotatable about an axis extending in the leftward/rightward direction. The pressure roller 150 is configured to provide the nip region NP in cooperation with the fusing belt 110 , when the fusing belt 110 is nipped between the pressure roller 150 and the nip plate 130 while the pressure roller 150 is in an elastically deformed state.
The pressure roller 150 has a metallic shaft 151 and a rubber layer 152 formed over an outer periphery of the shaft 151 . The shaft 151 is formed into a linear shape, with a radius that is substantially constant across the leftward/rightward direction.
The rubber layer 152 has a first end portion 152 A, a central portion 152 B, and a second end portion 152 C, in the axial direction (leftward/rightward direction) of the pressure roller 150 . The rubber layer 152 is formed into a concave shape such that respective outer diameters of the end portions 152 A and 152 C are larger than an outer diameter of the central portion 152 B when fixing operation is not being performed (heat is not being applied) and when fixing operation is being performed. In other words, the rubber layer 152 is formed such that the end portions 152 A and 152 C are thicker than the central portion 152 B.
The pressure roller 150 is rotationally driven by a drive motor (not shown) disposed in the main frame 2 . By the rotation of the pressure roller 150 , the fusing belt 110 is circularly moved along the nip plate 130 because of a friction force generated therebetween or between the sheet P and the fusing belt 110 . A toner image on the sheet P can be thermally fixed thereto by heat and pressure during passage of the sheet P at the nip region NP between the pressure roller 150 and the fusing belt 110 .
The stay 160 is adapted to support the end portions of the nip plate 130 through the flange portion 142 for maintaining rigidity of the nip plate 130 . The stay 160 is positioned on the opposite side of the nip region NP with respect to the nip plate 130 . The stay 160 has a substantially U-shape configuration in conformity with the outer shape of the reflection portion 141 covering the reflection plate 140 . For fabricating the stay 160 , a highly rigid member such as a steel plate is folded into substantially U-shape.
The stay 160 is disposed upward of the reflection plate 140 . The stay 160 has a top wall 161 , a front wall 162 , and a rear wall 163 . The top wall 161 is formed into a planar shape. The front wall 162 extends downward from a front end of the top wall 161 . The rear wall 163 extends downward from a rear end of the top wall 161 . As shown in FIG. 3 , the rear wall 163 is formed into an arcuate shape in cross-sectional view and has a central portion and end portions in the leftward/rightward direction, with the central portion recessed inward (frontward) more than the end portions in the frontward/rearward direction. In addition, the reflection portion 141 of the reflection plate 140 has a rear wall which is also formed into an arcuate shape in cross-sectional view in conformance with the shape of the rear wall 163 . The stay 160 and the reflection plate 140 are formed into these respective shapes using press working.
The stay 160 has left and right end portions that are respectively supported by left and right side frames SF (only a left side frame is shown in FIG. 3 ). The side frames SF are vertically movably supported by a fixing frame (not shown) of the fixing device 100 . In addition, the nip plate 130 and the reflection plate 140 are supported indirectly by the side frames SF through the stay 160 .
Coil springs CS (only a left coil spring is shown in FIG. 3 ) are provided for urging the respective side frames SF downward. Thus, the side frames SF press the nip plate 130 toward the pressure roller 150 through the stay 160 and the reflection plate 140 . Incidentally, as modifications, the halogen lamp 120 can be supported by the side frames SF or by the fixing frame. Further, the stay 160 and the nip plate 130 can be fixed to the fixing frame, whereas the pressure roller 150 is urged toward the nip plate 130 by a urging member. Moreover, instead of the coil spring CS, a combination of an arm and a coil spring is available.
As shown in FIG. 2 , the front wall 162 has a lower end at which is located an end face constituting a first supporting face 164 that supports the nip plate 130 through the flange portion 142 of the reflection plate 140 . The rear wall 163 has a lower end at which is located an end face constituting a second supporting face 165 that supports the nip plate 130 through the flange portion 142 of the reflection plate 140 .
As shown in FIG. 4A , the first supporting face 164 has a first downstream edge 164 A and a first upstream edge 164 B. The first downstream edge 164 A is located at a rear side, i.e. downstream in the sliding direction, of the first supporting face 164 , and the first upstream edge 164 B is located at a front side, i.e. upstream in the sliding direction, of the first supporting face 164 . In other words, the first downstream edge 164 A is located on a downstream of the first supporting face 164 , and the first upstream edge 164 B is located on an upstream of the first supporting face 164 , in a direction of conveyance of the sheets P.
The first downstream edge 164 A has a first point (first portion) A 1 , a second point (second portion) A 2 , and a third point (third portion) A 3 . The first point A 1 is located at the first end side; the second point A 2 is positioned at the central portion; the third point A 3 is located at the second end side in the leftward/rightward direction, i.e. the axial direction of the pressure roller 150 . The first point A 1 , the second point A 2 , and the third point A 3 are located on a straight line extending in the leftward/rightward direction, and are thus arrayed in the leftward/rightward direction. The first upstream edge 164 B is formed in conformance with the first downstream edge 164 A.
The second supporting face 165 is located downstream in the sliding direction of, and spaced away from, the first supporting face 164 . The second supporting face 165 has a second downstream edge 165 A and a second upstream edge 165 B. The second downstream edge 165 A is located downstream in the sliding direction of the second supporting face 165 , and the second upstream edge 165 B is located upstream in the sliding direction of the second supporting face 165 . The second upstream edge 165 B has a first end side, a central portion, and a second end side in the leftward/rightward direction, at which are respectively located a fourth point (fourth portion) B 4 , a fifth point (fifth portion) B 5 , and a sixth point (sixth portion) B 6 . The fourth point B 4 , the fifth point B 5 , and the sixth point B 6 are located on a convex line protruding toward the sliding direction upstream, such that the fifth point B 5 is located further toward the sliding direction upstream than the fourth point B 4 and the sixth point B 6 . The second downstream edge 165 A is formed in conformance with the convex-shaped second upstream edge 165 B.
A first distance L is defined as a distance in the frontward/rearward direction from the second point A 2 to the fifth point B 5 . Meanwhile, a second distance L 2 is defined as a distance in the frontward/rearward direction from the first point A 1 to the fourth point B 4 . The second distance L 2 is larger than the first distance L 1 . In addition, a third distance L 3 is defined as a distance in the frontward/rearward direction from the third point A 3 to the sixth point B 6 . The third distance L 3 is larger than the first distance L 1 , since the second supporting face 165 forms protruding shape.
Moreover, the difference between the first distance L 1 and the second distance L 2 (i.e. L 2 −L 1 ) and the difference between the first distance L 1 and the third distance L 3 (i.e. L 3 −L 1 ) can be ranging from 0.5 to 10.0 mm, or 1.0 to 7.0 mm, or 1.5 to 5.0 mm.
By making the distance L 2 between the first end sides (the first point A 1 and the fourth point B 4 ) and the distance L 3 between the second end sides (the third point A 3 and the sixth point B 6 ) greater than the distance L 1 between the central portions (the second point A 2 and the fifth point B 5 ) of the first downstream edge 164 A and the first upstream edge 164 B. Accordingly, a pair of ends 131 of the nip plate 130 in the leftward/rightward direction becomes more flexible than the central portion of the nip plate 130 in the leftward/rightward direction, as shown in exaggerated fashion in FIGS. 4B and 4C . In this way, as shown in FIG. 4D , the nip plate 130 can be imparted with a convex shape wherein the central portion 132 in the leftward/rightward direction protrudes farther than the ends 131 toward the pressure roller 150 . Incidentally, members such as the reflection plate 140 and the fusing belt 110 have been omitted in FIG. 4D for the sake of convenience.
Since the distance between the first downstream edge 164 A and the second upstream edge 165 B differs in the axial direction, the amount of protrusion of the central portion 132 can be adjusted properly. Accordingly, errors in the amount of protrusion can be reduced in comparison to conventional technology wherein the amount of protrusion of the central portion of the nip member is adjusted directly by performing machining (press working) on the surface of the nip member in contact with the fixing belt.
In addition, the supporting faces 164 and 165 can be easily formed by the aforementioned machining (press working), because the downstream edges 164 A and 165 A are arrayed in parallel as well as the upstream edges 164 B and 165 B. Comparatively, if these edges are not formed in conformance with each other, the machining can be more difficult.
The first point A 1 , the second point A 2 , the third point A 3 , the fourth point B 4 , the fifth point B 5 , and the sixth point B 6 are disposed within a sheet width BB. Here, the sheet width BB refers to a width of one of multiple types of sheets P that can be specified for the laser printer 1 . In other words, the fixing device 100 is configured to convey sheets P within a conveyance region having a prescribed width in the leftward/rightward direction (the same width as the sheet width BB shown), and to the nip region NP. Here, the conveyance region can be defined as an area where the nip region NP and the conveyed sheet P overlaps with each other, when viewed in the vertical direction.
Incidentally, the sheet width BB for determining respective positions of the points A 1 to B 6 can be 176 mm to conform to B 5 size, 215.9 mm to conform to letter or legal size, or 210 mm to conform to A4 size, of the International Organization for Standardization (ISO).
By thus locating the respective points A 1 to B 6 within the sheet width BB, the nip region NP within the applicable sheet width BB can be formed into a convex shape such as that described above, and wrinkling of the sheets P conforming to the sheet width BB can be prevented effectively.
The respective points A 1 to B 6 will now be described more specifically. The first point A 1 and the fourth point B 4 are disposed within a range at least 55 mm and at most 107 mm from a conveyance center line CL of the conveyance path of the sheets P in the axial direction. The third point A 3 and the sixth point B 6 are disposed within a range at least 55 mm and at most 107 mm from the conveyance center line CL of the conveyance path of the sheets P in the axial direction.
The first point A 1 and the fourth point B 4 are disposed within a range at least 60 mm and at most 95 mm from the conveyance center line CL in the axial direction. The first point A 1 and the fourth point B 4 are disposed within a range at least 60 mm and at most 95 mm from the conveyance center line CL in the axial direction.
Here, the conveyance center line CL refers to a line which constitutes a conveyance reference line when respective sheets P of various types differing in width are conveyed without altering the position of the center portion in the leftward/rightward direction, i.e. a line which runs through the center portion of different types of sheets P being conveyed.
The first downstream edge 164 A and the second upstream edge 165 B are formed substantially symmetrically relative to the conveyance center line CL of the sheets P. That is, a distribution along the axial direction of distances between the first downstream edge 164 A and the second upstream edge 165 B in the sliding direction is symmetrical with respect to the conveyance center line CL of the sheets P. In other words, a distribution along the axial direction of distances between the first downstream edge 164 A and the second upstream edge 165 B in the sliding direction is symmetrical with respect to a surface which contains the conveyance center line CL and is orthogonal to the leftward/rightward direction.
Here, the definition of “symmetrical” includes configurations wherein a difference of up to 0.9 mm exists between two distances: one distance between the edges 164 A and 165 B when measured at a location that is on one side of the conveyance center line CL and separated from the conveyance center line CL by X mm (an arbitrary distance), and another distance between the edges 164 A and 165 B when measured at a location that is on another side of the conveyance center line CL and separated from the conveyance center line CL by X mm (the same distance as the arbitrary distance).
In addition, the definition of “symmetrical” also includes configurations wherein a difference of up to 0.6 mm exists between two distances: one distance between the edges 164 A and 165 B when measured at a location that is on one side of the conveyance center line CL and separated from the conveyance center line CL by X mm (an arbitrary distance), and another distance between the edges 164 A and 165 B when measured at a location that is on another side of the conveyance center line CL and separated from the conveyance center line CL by X mm (the same distance as the arbitrary distance) in the leftward/rightward direction.
In addition, the definition of “symmetrical” also includes configurations wherein a difference of up to 0.4 mm exists between two distances: one distance between the edges 164 A and 165 B when measured at a location that is on one side of the conveyance center line CL and separated from the conveyance center line CL by X mm (an arbitrary distance) in the leftward/rightward direction, and another distance between the edges 164 A and 165 B when measured at a location that is on another side of the conveyance center line CL and separated from the conveyance center line CL by X mm (the same distance as the arbitrary distance).
According to these configurations, the sheets P can be more readily conveyed on a straight path following the conveyance center line CL in comparison to configurations wherein the distances between the first downstream edge 164 A and the second upstream edge 165 B in the sliding direction are not symmetrical.
As indicated by a broken line in FIG. 4A , the nip region NP is defined so as to be located downstream in the sliding direction of the first downstream edge 164 A and upstream of the second upstream edge 165 B. That is, the nip region NP is defined so as to not protrude out from the first downstream edge 164 A and the second upstream edge 165 B in the frontward/rearward direction. The pressure roller 150 is thereby brought into pressing contact with the nip plate 130 between the supporting faces 164 and 165 . Thus the ends 131 and the central portion 132 of the nip plate 130 can be bent by an intended amount, and the amount of protrusion of the central portion 132 can be adjusted effectively.
Incidentally, the present invention is not limited to the above-described embodiment, and can be utilized according to a variety of modifications, as will be described below. In the descriptions below, members having a structure substantially identical to that in this embodiment are assigned by the same numerals and characters as those shown in this embodiment.
In this embodiment, the first downstream edge 164 A was formed into a straight shape parallel to the leftward/rightward direction, and the second upstream edge 165 B was formed into an arcuate shape protruding frontward. However, the present invention is not limited to this configuration. For example, as shown in FIG. 5 , a first modification is available wherein the first downstream edge 164 A is formed into a convex shape protruding toward downstream in the sliding direction, and the second upstream edge 165 B is formed into a straight shape parallel to the leftward/rightward direction.
More specifically, in this embodiment, the first downstream edge 164 A is formed such that the second point A 2 at the central portion is located downstream in the sliding direction of the first point A 1 and the third point A 3 . In this case as well, the distance between the respective first end sides (the first point A 1 and the fourth point B 4 ) and the distance between the respective second end sides (the third point A 3 and the sixth point B 6 ) of the first downstream edge 164 A and the second upstream edge 165 B can be made larger than the distance between the respective central portions (the second point A 2 and the fifth point B 5 ). Thus, a similar effect as with the above-described embodiment can be achieved.
In addition, as shown in FIG. 6 , a second modification is available wherein the first downstream edge 164 A is formed into a convex shape protruding toward downstream in the sliding direction, and the second upstream edge 165 B is formed into a convex shape protruding toward upstream in the sliding direction. More specifically, in this modification, the first downstream edge 164 A is formed such that the second point A 2 at the central portion is located upstream in the sliding direction of the first point A 1 and the third point A 3 .
The second upstream edge 165 B is formed such that the fifth point B 5 at the central portion is located upstream in the sliding direction of the fourth point B 4 and the sixth point B 6 . In this case as well, the distance between the respective first end sides (the first point A 1 and the fourth point B 4 ) and the distance between the respective second end sides (the third point A 3 and the sixth point B 6 ) can be made larger than the distance between the respective central points (the second point A 2 and the fifth point B 5 ), and thus a similar effect as with the above-described embodiment can be achieved.
In addition, as shown in FIG. 6 , the first downstream edge 164 A and the second upstream edge 165 B can also be formed in parallel in the axial direction of the pressure roller 150 within a minimum sheet width BS. Here, the minimum sheet width BS refers to a width of sheets PS having the minimum width that can be specified with the laser printer 1 , in other words a minimum sheet width that can be specified using a width guide of the sheet supply tray 31 . For example, the minimum sheet width BS can be set to postcard width (100 mm).
According to this configuration, the minimum width sheets PS can be more readily conveyed on a straight path in the frontward/rearward direction in comparison to configurations wherein a first downstream edge and a second upstream edge are not parallel in the axial direction within the minimum sheet width BS.
In the above-described embodiment, the nip plate 130 is formed into a substantially plate-like shape. However, the present invention is not limited to this configuration. For example, as shown in FIG. 7A as a third modification, a front portion 231 of a nip plate 230 can be formed into an arcuate shape so as to curve upward. In this case, lower end faces of front walls 262 and 242 can be formed so as to be more upwardly offset than lower end faces of rear walls 263 and 243 of the stay 260 and the reflection plate 240 .
That is, in this modification, a first supporting face 264 is disposed at a location that is more upwardly offset than a second supporting face 265 . Because a lower end portion of the front wall 262 is bent frontward, the lower end face of the front wall 262 is formed over a wide area in the frontward/rearward direction, and a portion of this wide lower end face supports a front end face 232 of the nip plate 230 through the reflection plate 240 .
In addition, in the third modification, as shown in FIG. 7B , first supporting face 264 refers to a surface constituting a region wherein a portion of the wide lower end face of the front wall 262 overlaps with the front end face 232 when viewed in the vertical direction. Moreover, by making a distance LE between a pair of end points (A 1 and A 3 ) and another pair of end points (B 4 and B 6 ) larger than a distance LC between two central points A 2 and B 5 as shown in FIG. 7C , the same effect as with the above-described embodiment can be achieved.
In the above-described embodiment, the pressure roller 150 as a rotating member was configured such that, when the fixing operation is not being performed, the respective diameters of the end portions 152 A and 152 C are larger than the diameter of the central portion 152 B. However, the present invention is not limited to this configuration. A pressure roller can be configured such that, at least when fixing operation is being performed, diameters of end portions are larger than a diameter of a central portion.
As one example of the above configuration, the pressure roller can be configured to have a shaft, an elastic layer covering the shaft, and a tube over the elastic layer, wherein a first end portion and a second end portion of the tube in the axial direction have wrinkles. In this case, when fixing operation is not being performed, the respective end portions and the central portion of the pressure roller have substantially the same diameter. However, when fixing operation is being performed, i.e. when heat is applied to the pressure roller, the wrinkles expand, and the respective diameters of the end portions of the pressure roller become larger than the diameter of the central portion.
As another example, the pressure roller can be configured to have a shaft and an elastic layer coating the shaft, wherein the respective diameters of a first end portion and a second end portion of the shaft are smaller than the diameter of a central portion of the shaft and, in addition, the diameter of the elastic layer is constant in the axial direction. In this case as well, when fixing operation is not being performed, the respective end portions and the central portion of the pressure roller have substantially the same diameter, but the elastic layer is thick at the end portions thereof and thin at the central portion thereof, and when fixing operation is being performed, i.e. when heat is applied to the pressure roller, the end portions of the elastic layer expand more than the central portion of the elastic layer, and the respective diameters of the end portions of the pressure roller become larger than the diameter of the central portion of the pressure roller.
In the above-described embodiment, the distances L 2 and L 3 between the pair of end points (A 1 and A 3 ) and the pair of end points (B 4 and B 6 ) are respectively larger than the first distance L 1 . However, the present invention is not limited to this configuration. If at least a distance between end points at one end is made larger than the first distance, distances between respective end points can be configured in any arbitrary manner.
In the above-described embodiment, the nip region NP was prescribed to be located downstream in the sliding direction of the first downstream edge 164 A, and upstream in the sliding direction of the second upstream edge 165 B. However, the present invention is not limited to this configuration. The nip region can be located downstream of the first point, and the third point, and upstream of the fourth point and the sixth point. That is, the nip region can protrude toward upstream of the second point and downstream of the fifth point at the central position.
In the above-described embodiment, the nip plate 130 supports the stay 160 through the reflection plate 140 . However, the present invention is not limited to this configuration. The nip member may support the stay directly.
Further, the sheet P can be an OHP sheet instead of plain paper and a postcard.
Further, in the depicted embodiment, the pressure roller 150 is employed as a rotating member. However, a belt like pressure member is also available.
Further, in the depicted embodiment, the image forming device is the monochromatic laser printer. However, a color laser printer, an LED printer, a copying machine, and a multifunction device are also available. In this case, the axial direction of one of the rollers supporting the belt constitutes the axial direction of the rotating body.
Further, in the depicted embodiment, the nip plate 130 is employed as a nip member. However, a block shaped member or a pad like member is also available.
Further, in the depicted embodiment, the halogen lamp 120 is employed as a heater. However, a carbon heater is also available.
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Some fixing devices include a nip member, an endless belt, a rotating member and a stay. The stay, in some arrangements, has a first supporting face. Additionally, the first supporting face includes a first downstream edge. The first downstream edge includes a first portion, a third portion, and a second portion. According to various aspects, the second portion is positioned between the first portion and the third portion. The second supporting face includes a second downstream edge. The second downstream edge has a fourth portion, a sixth portion, and a fifth portion. According to further aspects, the second portion and the fifth portion define a first distance while the first portion and the fourth portion define a second distance, and the third portion and the sixth portion define a third distance. The second distance and the third distance is longer than the first distance in some examples.
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FIELD OF THE INVENTION
[0001] The present invention relates to a bias-T circuit.
BACKGROUND OF THE INVENTION
[0002] Bias-T circuits are useful, for example, for providing both a radio frequency (RF) signal and DC voltage down a single transmission line to a modulator.
[0003] A basic example of a known bias-T circuit is shown in FIG. 1 . The bias-T circuit comprises two inputs: a radio frequency input 102 and a DC bias input 104 . The RF input 102 is connected to a DC blocking capacitor 106 . The DC bias input is connected to an RF blocking inductor 108 . The DC blocking capacitor 106 and the RF blocking inductor 108 are both connected to the output 110 of the bias-T circuit. The output signal is the combined RF signal and DC bias voltage.
[0004] The DC blocking capacitor 106 provides a low impedance path to the RF signal from the RF input 102 to the output 110 . In addition, the RF blocking inductor 108 provides a high impedance path to the RF signal, and this prevents the RF signal from diverting into the DC bias input. However, the RF blocking inductor 108 provides a low impedance path to the DC bias voltage from the DC bias input 104 through to the output 110 . The DC blocking capacitor 106 presents a high impedance to the DC bias voltage, and this prevents the DC bias voltage from entering the RF input 102 , which could be damaging to the equipment supplying the RF signal.
SUMMARY OF THE INVENTION
[0005] It has been observed that there is a problem with this conventional approach to providing a bias-T circuit in that whereas using bigger inductors or using multiple inductors can improve the impedance over a relatively wide RF frequency range, to do so is not conducive to reducing the size of the circuit and in particular is not conducive to fitting the circuit on a small printed circuit board (PCB) for, for example, a pluggable optical module.
[0006] It is an aim of the present invention to provide a new type of bias-T circuit, and in particular it is an aim of the present invention to provide a new type of bias-T circuit that can provide a good level of performance over a wide frequency range whilst at the same time being suitable for use in small devices.
[0007] According to one aspect of the present invention, there is provided a bias-T circuit including a radio frequency signal input device and a dc bias input device connected in parallel with an output: the radio frequency signal input device including a capacitive element in series with the output; and the dc bias input device including a radio frequency transistor for controlling the dc bias level at the output.
[0008] In a preferred embodiment, the f T value of the radio frequency transistor is at least 30 GHz, more preferably at least 50 GHz and yet more preferably at least 70 GHz.
[0009] In one embodiment, the dc bias input device further includes at least one ferrite bead.
[0010] In one embodiment, the circuit further includes at least one operational amplifier for controlling the bias of the radio frequency transistor.
[0011] In one embodiment, the radio frequency transistor includes a base electrode connected to the output of the operational amplifier, a collector electrode connected to the output and an emitter electrode connected to a voltage supply. Preferably, the collector electrode of the radio frequency transistor is also connected to a non-inverting input of the operational amplifier to create a feedback loop.
[0012] According to another aspect of the present invention, there is provided an optical modulation system comprising: a bias-T circuit as described above; and an optical modulator connected to the output of the bias-T circuit, wherein said optical modulator is powered by the dc bias input device and modulates an optical signal on the basis of a radio frequency signal from the radio frequency signal input device.
[0013] In one embodiment, the optical modulator is connected to the output via a transmission line.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] For a better understanding of the present invention and to show how the same may be put into effect, reference will now be made, by way of example only, to the following drawings in which:
[0015] FIG. 1 shows a basic example of a known bias-T circuit;
[0016] FIG. 2 shows an active bias-T circuit according to an embodiment of the present invention;
[0017] FIG. 3 shows a DC equivalent circuit of the active bias-T circuit of FIG. 2 ;
[0018] FIG. 4 shows an RF equivalent circuit of the active bias-T circuit of FIG. 2 ; and
[0019] FIG. 5 shows an optical modulation system comprising a bias-T circuit.
DESCRIPTION OF PREFERRED EMBODIMENT
[0020] Reference is first made to FIG. 2 , which shows a bias-T circuit 200 according to an embodiment of the present invention. The bias-T circuit 200 comprises an RF input 102 and a DC bias input 104 and an output 110 . The RF input 102 is connected to a DC blocking capacitor C 1 , which performs the function of preventing the DC bias voltage from entering the RF signal source.
[0021] The circuit has two high frequency ferrite bead inductors L 1 and L 2 connected in series at the point labelled A, which inductors have a relatively small physical size. The inductors L 1 and L 2 are connected to the collector of an NPN bipolar silicon-germanium (SiGe) type high performance RF transistor Q 1 . The RF transistor Q 1 has a transition frequency, f T value of 70 GHz, wherein the f T value is the theoretical frequency at which the current gain (h fe ) of the transistor is unity (i.e. 0 dB).
[0022] The DC bias input 104 is connected via a resistor R 2 to the non-inverting input of an operational amplifier U 1 A. The inverting input of the op-amp U 1 A is connected to ground. The output of the op-amp U 1 A is connected to the base of transistor Q 1 via two resistors R 3 and R 5 . A resistor R 1 is connected in a feedback loop from the point between the two inductors L 1 and L 2 to the non-inverting input of U 1 A.
[0023] The emitter of Q 1 is connected to a resistor R 4 , which in turn is connected to a negative voltage −V. A capacitor C 2 is connected between the negative voltage −V and the point between resistors R 3 and R 5 .
[0024] The operation of the active bias-T circuit 200 will now be described, beginning with the setting of the DC bias voltage. The DC bias voltage is applied to the input 104 , and this sets the voltage on the one side of resistor R 2 . Since the non-inverting and inverting inputs of the op-amp U 1 A must be at the same voltage, and the inverting input is fixed at ground, then the voltage at the non-inverting input is 0 V. Therefore, there is a voltage drop equal to the value of the DC bias voltage across resistor R 2 , and hence a current through the resistor equal to the DC bias voltage divided by the resistance of R 2 . Since no current flows into the input of the op-amp U 1 A, the current through resistor R 1 must be the same as though R 2 , and, hence, the voltage drop across R 1 is −1×DC bias voltage. Therefore, as the non-inverting input of U 1 A is 0 V, the voltage at the point between L 1 and L 2 is approximately −1×DC bias voltage. Since the inductor L 1 presents a low impedance to DC, the voltage at point A and also at the DC bias output voltage is also approximately −1×DC bias input voltage.
[0025] The voltage at point A is set to this value due to the feedback loop of the operational amplifier U 1 A and transistor Q 1 , as the output of U 1 A will be such so as ensure that the voltage at A is maintained. It does this by setting the voltage at the base of the transistor Q 1 in order to achieve the required voltage at the emitter.
[0026] Connecting the feedback to non-inverting input of U 1 A, as described above, has the advantage that only one operational amplifier is required.
[0027] The DC equivalent circuit 300 as seen to the DC bias voltage is shown in FIG. 3 . As mentioned previously, the capacitor C 1 blocks the DC from entering the RF input, and hence this is shown as an open circuit in FIG. 3 . The capacitor C 2 from FIG. 2 also acts as an open circuit to DC, and this is therefore also not present in the DC equivalent circuit 300 . The inductors L 1 and L 2 are shown as short-circuits to DC.
[0028] In this example, the value of the DC bias input voltage is 1.7V and the value of −V is −4V. The value of the voltage at A is therefore −1.7V, and this therefore corresponds to the value of the DC bias at the output 110 .
[0029] Referring again to FIG. 2 , the operation of the circuit from the point of view of the RF signal will now be considered. The RF signal is applied to the RF input 102 , and the capacitor C 1 presents a low impedance to the RF signal. The RF signal can then pass to the output 110 .
[0030] The RF signal is separated from the DC bias input by the resistors R 1 and R 2 . The values shown in the embodiment in FIG. 2 are 10K for both of R 1 and R 2 . Since the transmission line over which the RF signal is to be sent in the preferred embodiment has an impedance of 50R, the combined impedance of the two resistors is significantly higher, and hence the impedance to the RF signal is sufficiently high. In addition, the input to the operational amplifier U 1 A is of a high impedance and the RF signal is therefore not affected by being connected to U 1 A.
[0031] The RF signal is separated from the voltage supply −V by the RF transistor Q 1 . The RF transistor provides a good level of impedance to the RF signal over a relatively wide frequency range from relatively low frequency signal components to relatively high frequency signal components. The ferrite bead inductors L 1 and L 2 provide compensatory impedance for any particularly high frequency signal components that may be present in the RF signal.
[0032] The capacitor C 2 is used to bleed off RF signals that are amplified by the op-amp U 1 A to the negative supply voltage. C 2 can also help to prevent DC loop oscillation in the circuit.
[0033] FIG. 4 shows the RF equivalent circuit 400 , as seen to the RF signal. This shows the capacitor C 1 acting as a short-circuit and not impeding the RF signal. As stated above, resistors R 1 and R 2 act as sufficiently high impedances, and this path is therefore shown open-circuit to the RF signal. Capacitor C 2 is shown as providing a short-circuit path to the negative supply −V.
[0034] The relatively small physical dimensions of all the components present in the circuit, allow the circuit to be constructed on a PCB of a relatively small size.
[0035] Reference is now made to FIG. 5 , which shows an optical modulation system 500 comprising the active bias-T circuit of FIG. 1 . The RF input 102 and DC bias input 104 are connected to the bias-T circuit 200 , as described above. The combined RF and DC bias output is connected to a high speed transmission line 502 . The other end of the transmission line 502 is connected to an electric-absorption optical modulator 504 . The optical modulator is then driven by the DC bias voltage and modulates an optic signal on the basis of the RF signal to provide a modulated optical signal. The above-described Bias-T circuit is useful, for example, in 10 Gb/s applications, where the signal spectrum can range from roughly 10 kHz up to 10 GHz.
[0036] The Bias-T circuit described above also allows exact set-up of the DC Bias voltage without the use of a monitor.
[0037] The applicant draws attention to the fact that the present invention may include any feature or combination of features disclosed herein either implicitly or explicitly or any generalisation thereof, without limitation to the scope of any definitions set out above. In view of the foregoing description it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention.
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A bias-T circuit including a radio frequency signal input device and a dc bias input device connected in parallel with an output. The radio frequency signal input device includes a capacitive element in series with the output. The dc bias input device includes a radio frequency transistor for controlling the dc bias level at the output. The f T value of the radio frequency transistor is at least 30 GHz, more preferably at least 50 GHz and yet more preferably at least 70 GHz.
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BACKGROUND OF THE INVENTION
The present invention relates to a new and improved method of, and apparatus for, controlling the operating conditions prevailing at a ring spinning machine, by means of a control or monitoring apparatus which travels from spinning position to spinning position, there being consecutively checked at each spinning position the presence of a yarn or thread which is being formed thereat and for the absence of fiber lap-ups on at least one of both delivery rolls of the drafting arrangements.
A ring spinning machine for the final spinning process of a yarn or thread--hereinafter conveniently usually referred to as simply a yarn--consists of a large number of spinning positions, as a rule exceeding 400 spinning positions. Each spinning position is provided with a drafting arrangement where the infed fiber material, also referred to commonly in the art as roving, is drafted to the final yarn fineness or count and subsequently is spun into a yarn. Twist is imparted to the spun yarn and the same is wound by means of a spindle and ring arrangement.
Notwithstanding continuous efforts it has heretofore not been possible to avoid the occurrence of end or yarn breakages at a spinning position between the drafting arrangement and the spindle. This relatively rare event, however, is extremely troublesome since it involves both production losses and additional expenditure in work. Furthermore, there is brought about losses of material inasmuch as the loose fibers, which continue to emerge from the pair of delivery rolls of the drafting arrangement, are on longer caught by the twist of the formed yarn but infed by means of a suction nozzle of a yarn suction device to a collector or collecting device.
It happens now and again that such loose fibers, instead of moving into the suction nozzle, lap-up on one or both delivery rolls. This fiber lap-up increases in size as long as the supply of fibers is not interrupted, or as long as the yarn forming process is not reestablished. Failure to interrupt such undesirable lap-up formation ultimately will result in damage to the drafting arrangement of the involved spinning position or location. Therefore, in the spinning plant the operating personnel must continuously control and monitor the operating conditions of the ring spinning machine. The broken yarn ends must be pieced-up, and any possible fiber lap-ups formed on the rolls must be previously eliminated.
In more recent times there have become known to the art equipment which attempts to replace the work of the operating personnel at the ring spinning machine by automation through the use of operating or servicing or control devices which perform two tasks:
(a) Scanning the operating conditions at the spinning position, i.e., detecting the formation of yarn, the presence of a fiber lap-up on the rolls of the drafting arrangement, or entry of the roving at the drafting arrangement and so forth.
(b) Performing an actual operating or servicing operation at the spinning location or position, such as, for instance, re-piecing the broken yarn, stopping the supply of material to the drafting arrangement and so forth.
These operations are performed as a function of the detected operating or working conditions at the relevant spinning position or location.
In the first instance the present invention is concerned with the detection or recognition of certain working or operating conditions at the spinning position. Various solutions, intended to perform this objective, have already been proposed in the art.
Thus, for instance in Swiss Patent No. 571,588 and the cognate U.S. Pat. No. 3,950,925 and German Patent Publication No. 2,339,654, there is disclosed a proposal for automatically piecing-up yarns on ring spinning machines by using a scanning device which simultaneously detects both the absence of the yarn and any lap-up on the delivery rolls. With this equipment a light source is directed at the path of travel of the strand of fibers emerging from the delivery rolls and which are not spun into a yarn. The fiber strand reflects the light beam onto a photocell. With this proposal there is exploited the fact that the path of travel of the spun-in strand of fibers, i.e. the yarn which is being formed, does not coincide with the path of travel of the strand which is not spun-in and which is sucked into the suction device of the ring spinning machine.
The detecting device is mounted upon a travelling control device. This equipment is associated with the drawback that there is needed an extremely precise guiding of the control device along the ring spinning machine, since the spacing between the prior mentioned respective paths of travel of the strands of fibers is extremely small. Such requisite precise guide devices are associated with high equipment expenditure, without which the control device cannot satisfactorily perform.
According to a second proposal the strand of fibers emerging from the delivery rolls is sucked-off and there is activated a sensor in the suction duct. However, the use of this equipment is limited to a non-travelling control device coordinated to individual spinning positions, and, thus, cannot be employed for control devices which migrate from spinning position to spinning position.
Moreover, from Swiss Patent No. 578,058 and the corresponding U.S. Pat. No. 4,030,281 there is known to the art a control device for an automatic yarn piecing device for ring spinning machines, which, among other features, contains mechanism for detecting the fiber lap-ups on the delivery rolls of the drafting arrangement. This mechanism comprises two rolls provided with axial openings. These rolls are mounted at the immediate vicinity of the delivery rolls. Now, if a fiber lap-up develops on a delivery roll, then the roll is set into rotation owing to contact of the lap-up with the roll, and such is detected for each roll by means of a light beam and a photocell. Instead of using an optical control system there is also proposed a contact tongue for the lower, metallic delivery roll.
Mechanical scanning of the delivery roll is associated with the drawback that there is here also required an extremely precise and expensive guiding of the control device along the machine. This structure equally is of relatively complicated design, thereby detrimentally influencing its price and operational reliability.
SUMMARY OF THE INVENTION
Hence, with the foregoing in mind, it is a primary object of the present invention to provide an improved method of, and apparatus for controlling the operating conditions of a ring spinning machine in a manner not associated with the aforementioned drawbacks and limitations of the prior art proposals.
Another and more specific object of the present invention aims at eliminating the disadvantages of the prior art equipment for detecting certain operating conditions at the ring spinning positions of a spinning machine, and specifically proposes a method and control or monitoring apparatus wherein in a simple and inexpensive manner there can be dispensed with the need for any precise guiding of the equipment, without impairing the operational reliability thereof.
Still a further significant object of the present invention aims at providing a new and improved method of, and apparatus for, controlling the operating conditions of a ring spinning machine, with the use of relatively simple, inexpensive and highly reliable equipment, avoiding the need for the complicated and precise guiding structure and the associated drawbacks which prevail with prior art equipment as discussed above.
Yet a further significant object of the present invention is directed to a new and improved construction of apparatus for controlling the operating conditions of a ring spinning machine in an extremely reliable and accurate manner, but which apparatus is relatively simple in construction and design, reasonably economical to fabricate, does not require any complicated maintenance and servicing work, and is not readily subject to breakdown or malfuction.
Now in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the method aspects of the present invention are manifested by the features that for the purpose of consecutively controlling or monitoring the operating conditions at a plurality of spinning positions or locations of a spinning machine, there are detected yarn breakages and lap-up formations on the rolls of the drafting arrangement. Upon detection of a yarn breakage at a predetermined spinning position there is rendered ineffectual at such spinning position the suction air stream from the suction system of the ring spinning machine and such predetermined spinning position is checked for the presence of a fiber stream.
As already alluded to above, the invention is not only concerned with the aforementioned method aspects, but also involves control or monitoring apparatus for implementation of such method. Now the control apparatus, for the performance of the method taught by the invention, and which travels from spinning position to spinning position along a ring spinning machine equipped with a suction device provided at each spinning position, is manifested by the features that there is provided a yarn detector which controls the presence of the yarn between the delivery rolls of the drafting arrangement and the spindle. Also, there is provided a fiber stream-deflecting device which, in the event of yarn breakage and in response to its activation by the yarn detector, takes-up the fiber stream which is carried or entrained by the suction air stream of the suction system and transfers such to a fiber detector.
According to a preferred embodiment of the control apparatus of the present invention, the fiber stream-deflecting device embodies a suction nozzle whose suction action upon the fiber stream exceeds the action of the suction nozzle of the yarn suction device at the spinning position.
Furthermore, the fiber detector can be constructed in the form of a light barrier which is responsive to the presence of loose fibers in an air stream, and also can be designed in the form of a collecting shield or grid for loose fibers, the air resistance of which in the presence of a fiber stream increases and, in turn, initiates a switching operation.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above, will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
FIG. 1 is a schematic cross-sectional view of part of a ring spinning machine equipped with control apparatus constructed according to the teachings of the present invention and shown in its work position;
FIGS. 2a, 2b, 2c and 2d respectively schematically illustrate various operating conditions which are to be controlled or monitored at a spinning position of a ring spinning machine;
FIG. 3a schematically illustrates in fragmentary sectional view a variant embodiment of the control or monitoring apparatus of FIG. 1; and
FIG. 3b illustrates in fragmentary cross-sectional view a further variant embodiment of the control or monitoring apparatus shown in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Describing now the drawings, it is to be understood that only enough of the ring spinning machine has been shown herein, in order to simplify the illustration of the drawings, and to enable those skilled in the art to readily understand the underlying principles and concepts of the present invention. Turning attention now to FIG. 1, there is shown therein a spinning position of a ring spinning machine and the same will be seen to essentially comprise a standard and therefore not further shown creel for a rotatably supported roving bobbin 1. The roving bobbin 1 supplies a fiber roving 2 to a drafting arrangement, generally indicated by reference character 3. This drafting arrangement 3 will be seen to comprise a pair of infeed or take-in rolls 4 and 5 and a pair of outfeed or delivery rolls 6 and 7. The spinning position will be seen to further comprise a yarn guide 8 and a combination of a ring 9, traveller 10 and spindle 11. At the exit side of the pair of delivery rolls 6 and 7 there is arranged a suction nozzle 12 of a conventional and therefore simply schematically indicated yarn suction device 12a which is connected continuously with a suitable and thus not particularly illustrated vacuum source. Hence, the yarn suction device 12a in conjunction with the nozzle 12 thereof exerts an active suction action at the related spinning location or position throughout the entire operating time of the machine.
The spindles 11 of all of the spinning positions which are arranged in a row are supported by a spindle rail 13 as is conventional in this technology. To simplify the illustration there has only been shown one of the spinning positions, but it will be apparent from the description to follow that each spinning position may be similarly constructed and the teachings of the invention entail the sequential monitoring and control of the operating conditions prevailing at each such spinning position.
Now during normal operation of any given spinning position of the aforedescribed type, the fiber roving 2 is withdrawn from the roving bobbin 1 by the rotation of the pair of infeed or input rolls 4 and 5. Within the drafting arrangement 3 the roving 2 is drafted, as required, in a manner such that there emerges from the pair of delivery rolls 6 and 7 a fine strand of fibers 14 (FIG. 2b) and which is caught and spun-in by the twist of the finished yarn 15 produced by rotation of the spindle 11 and imparted by means of the ring 9 coacting with the traveller or traveller ring 10. The finished yarn 15 passes through the yarn guide 8, and while there is formed a balloon 16, it is wound onto the yarn bobbin 17 during rotation of the spindle 11 by conventional means unimportant for understanding this invention and thus not here particularly further shown.
Now, the spinning position illustrated in FIG. 1 will be seen to additionally comprise a roving clamping device 18, the function of which is the controlled interruption of the infeed of the roving 2 to the drafting arrangement 3, as will be explained more fully hereinafter.
Continuing, a funnel 19 is rigidly mounted on the not particularly shown machine frame and through such funnel 19 there is guided the fiber roving 2. A double-arm lever 20 is pivotably supported at a pivot shaft or axle 21 which is also rigidly connected to the frame of the ring spinning machine supporting the working or operable elements of the spinning position. This double-arm lever 20 is provided at its righthand end, shown in the drawing of FIG. 1, with a conical extension 22. This conical extension or conical member 22, upon the lever 20 assuming the pivoted-in position shown in phantom lines in FIG. 1, contacts the inner surface 19a of the funnel 19 in a manner such that the roving 2 is clamped between this inner surface 19a and the outer surface 22a of such conical extension or member 22. At the other end of the double-arm lever 20 there is provided an impact or deflecting plate 23 for an air stream, generally indicated by reference character 23'. Now, if under normal operating conditions there is produced a yarn, then the lever 20 assumes the pivoted-up position shown in full lines in FIG. 1, where it is held by any suitable means, for instance, by way of example, by appropriately selecting its center of gravity. Now, when such double-arm lever 20 is pivoted into the above-discussed phantom line position of FIG. 1, the roving 2 which is clamped between the inner surface 19a of the funnel 19 and the outer surface 22a of the conical extension or member 22 is torn by the action of the pair of infeed or take-in rolls 4 and 5 which continue to rotate, the tearing of the roving 2 occurring at a location between the funnel 19 and the infeed rolls 4 and 5 of the drafting arrangement 3. Consequently, the further supply of roving 2 to the drafting arrangement 3 is interrupted.
The roving clamping device 18, here shown to be activated by the inflowing air stream 23' which impinges against the impact plate 23 or equivalent structure, is but one of many devices of this type which are known, and consitutes but one exemplary manner of reliably displacing the roving clamping plate 18. Obviously, the present invention is not intended to be limited to any specific type of roving clamping device or any specific technique for activating the same. It should be readily understood that, in fact, any type of roving clamping device which can be activated by a travelling control or monitoring apparatus can be beneficially combined with the invention herein described.
Now the control or monitoring apparatus, generally indicated by reference character 24, and which travels along the ring spinning machine, will be seen to comprise a suitable supporting structure 25 which is supported by means of the lower rolls 26 on the floor of the spinning mill or other area where the equipment is used and by means of the upper rolls 27 is supported upon the spindle rail 13. The upper rolls 27 serve to guide the control apparatus 24 in longitudinal direction along the ring spinning machine from one spinning location to the next spinning location and so forth. Of course, the control apparatus 24 also could be guided in a different way, for instance, it could be guided at its upper part 24' on the not particularly shown creel of the ring spinning machine, and the nature of the guiding system for the control apparatus 24 is of subordinate importance.
For the purpose of controlling or monitoring the operating conditions prevailing at the individual spinning positions the control or monitor apparatus 24 is provided with a yarn feeler 28. In the exemplary embodiment under discussion, this yarn feeler 28 may comprise a system of a light emitter 29 and a light receiver 30. The emitted light beam 31 of the light emitter 29 is reflected by the yarn 15 when it is present and is received by the light receiver 30. Now, if normal working conditions are present at the monitored spinning position, then the light receiver 30 merely transmits an appropriate signal via the circuit line 32 to a control device 32'.
Of course, the teachings of the invention are not limited in any way to a yarn detector 28 in the form of the indicated optical detector described by way of example herein and known as such to the art, but all known and suitable detecting methods, such as for instance, by using mechanical feelers, temperature feelers, travelling detectors and so forth, can be employed to advantage.
Equally, it is of no consequence where checking or control of the yarn is carried out along its path of travel or movement. Thus, it is perfectly acceptable to detect the yarn at the region of the balloon 16 or some other location.
Furthermore, it will be seen that the control apparatus 24 is provided with a fiber stream-deflecting device 33 which serves to deflect the fiber stream 54 (FIG. 2b) and to transfer the same to a fiber detector 34, as will be explained more fully hereinafter.
A suction tube 35 equipped with a suction nozzle 36 is arranged in telescopic fashion upon an inner tube 37. This suction tube 35 along with its suction nozzle 36 is movable essentially at right angles to the direction of movement of the control apparatus 24, i.e., also transversely with respect to the longitudinal direction of the ring spinning machine. In the embodiment shown, displacement of the suction tube 35 is accomplished by means of a pneumatic cylinder 38 connected with the suction tube 35 by means of a connecting rod 39. The pneumatic cylinder 38 is operatively connected by means of a duct 40 and a valve 41 with a suitable vacuum source, generally schematically indicated in FIG. 1 by reference character 100. This pneumatic cylinder 38 is here shown to be of the single-acting type and in its non-pressurized position, as shown in solid lines in FIG. 1, is retained at its rearmost stop or rearmost position by the action of a spring 42. In this position, corresponding to the idling position of the fiber stream-deflecting device 33, the suction nozzle 36 is located sufficiently far away from the ring spinning machine that it cannot exert any influence upon the operating conditions prevailing at the relevant spinning position.
Now, the fiber detector 34 is capable of detecting the presence of loose fibers in an air stream and of transmitting a corresponding signal via the electrical circuit line or conductor 43 to the control device 32'. By means of the suction tube 35 there is continuously sucked-in air, or at least during such time as the suction tube 35 is in its moved-out or extended position, shown in phantom lines in FIG. 1, and which position corresponds to the working position of the fiber stream-deflecting device 33, likewise shown in phantom lines in such FIG. 1. At this time the suction force exerted by the suction tube 35 exceeds the suction force exerted by the suction nozzle 12 of the yarn suction system or yarn suction device 12a. For this purpose the inner tube 37 is connected with a suitable vacuum source, such as the here exemplary illustrated fan 44. The exhaust air of the fan 44 or equivalent structure can be used for activating the pneumatically actuated roving clamping device 18. To that end, the exhaust air is guided through a tube or duct 45 containing a controllable baffle or flap valve 46 therein. The controllable baffle or flap valve 46 is controlled by means of a pneumatic cylinder 47 which can be controlled by the duct 48 and the control valve 49, so that the baffle or flap valve 46 or equivalent structure is held in either the position shown in full lines in FIG. 1, where the exhaust air flows freely via the exhaust tube or duct 50, if required through a suitable filter (not shown), to the surrounding room, or is moved into the phantom line position while overcoming the spring force of the spring 51 arranged within the pneumatic cylinder 47. Now, if the baffle 46 is in the phantom line position, then the exhaust air is guided through the tube or duct 52 to the outlet orifice 53 thereof which terminates immediately before and in the direct vicinity of the impact plate 23 of the roving clamping device 18. By the action of the air stream 23' emerging from the outlet orifice 53 and striking against the impact plate 23, the double-arm lever 20 is shifted from the full line position of FIG. 1 into the pivoted-in phantom line position, and, as described above, the supply of roving 2 to the drafting arrangement 3 of such spinning position is then interrupted.
Now, in order to further explain with greater clarity the function of the apparatus, there will be considered and described in conjunction with FIGS. 2a and 2b, 2c and 2d, different possible operating conditions which can prevail at any given spinning position or location of the ring spinning machine.
Now, in FIG. 2a there is schematically shown the spinning position when it is operating under normal operating conditions. The yarn 15 is spun in conventional fashion and extends in a taut condition from the pair of delivery rolls 6 and 7 of the drafting arrangement 3 to the yarn guide 8. If the few fibers which are not spun-in by the twist of the yarn, and which in terms of the quantity thereof can be neglected, are considered to be negligible, then no fibers are sucked-in by the suction nozzle 12. Control apparatus 24, only indicated in FIG. 2a to simplify the illustration by the main working elements 28 to 31 and 35 to 37, passes the spinning position and its yarn feeler 28 detects the presence of the yarn 15. The control or monitoring device 24 thus decides that at this particular spinning position normal operating conditions prevail and then continues to move on to the next spinning position. During this process the suction tube 35 remains in its retracted position, with the result that the suction action of the suction nozzle 36 is ineffectual at such spinning position.
Now, in FIG. 2b there are shown conditions which prevail at a given spinning position when an end or yarn breakage has occurred and wherein the fibers which still emerge from the nip of the pair of delivery rolls 6 and 7 of the drafting arrangement 3 form a stream of fibers, hereinafter simply referred to as a fiber stream 54, which is no longer spun-in. This fiber stream 54 is eliminated by means of the suction nozzle 12 of the yarn suction device or system 12a in a manner conventional in this particular art.
Now, at this spinning position some good fiber material is of course guided into the yarn suction device or system 12a, but there does not exist any danger of damaging the working elements of the machine, i.e., there is not required any immediate intervention on the part of the operating personnel.
In FIG. 2c there is shown what happens following the arrival of the travelling control device 24 at a spinning position where there prevail the operating conditions described above with reference to FIG. 2b. The light receiver 30, due to the absence of any reflection of the emitted light beam, does not receive any reflected light beam 31. Now, in this case an appropriate signal indicative of this condition is transmitted by the electrical circuit line or conductor 32 to the control device 32' (FIG. 1). This signal activates the flow of compressed air by means of the valve 41 into the pneumatic cylinder 38. Thus, the fiber stream-deflecting device 33 is brought into its working position, i.e., the suction tube 35 is moved into its extended position, shown in phantom lines in FIG. 1. In this position the suction nozzle 36, as best seen by referring to FIG. 2c, is placed between the nip of the delivery roll 6 and 7 of the drafting arrangement 3 and the suction nozzle 12 of the yarn suction system 12a. Now, since the suction action of the suction nozzle 36 is greater than the suction action of the suction nozzle 12, the fiber stream 54 (FIG. 2b) is immediately deflected into the suction tube 35, i.e., away from the spinning position of the ring spinning machine and in the direction of the travelling control device 24. In FIG. 2c the deflected fiber stream has been generally designated by reference character 54'. The fibers of such fiber stream 54' which now flow within the suction tube 35 and in the inner tube 37 are detected by the fiber detector 34 of FIG. 1. By means of the circuit line or conductor 43 this fiber detector 34 then transmits a signal to the control device 32' (FIG. 1) which is then appropriately processed in accordance with the desired control operations. With the operating conditions as shown in FIG. 1, the control device 32', upon receiving both signals, via the circuit lines or conductors 32 and 43, by means of which the operating conditions at the spinning position according to FIG. 2b can be unmistakeably recognized, reaches the conclusion that no immediate danger of damage to the equipment prevails at this spinning position, and thus, transmits an appropriate signal to the control apparatus 24 to resume its travelling motion. The baffle or flap valve 46 then remains in the position indicated by full or solid lines and the roving supply therefore is not interrupted.
If, however, the control or monitoring apparatus 24 is equipped with further operating elements, only shown in FIG. 1 schematically, such as for instance, conventional elements or means 120 for piecing-up the broken yarn ends, it is possible to set the command sequence in such a manner that the control device 32' transmits the command signals to the above-mentioned operating elements or means so as to cause them to become operative and to perform the requisite control or operating action, for instance, the piecing of the broken yarn ends.
Finally, the most dangerous operating conditions, as exemplified in the showing of FIG. 2d, can occur at the spinning position. Here, the fibers emerging from the nip of the pair of delivery rolls 6 and 7 of the drafting arrangement 3, following the occurrence of yarn or end breakage, no longer are spun into a yarn 15 and are no longer sucked-in and eliminated by the suction nozzle 12 of the yarn suction device or system 12a. Rather, such emerging fibers tend to lap-up on the delivery roll 6 and form a lap-up 55. Formation of lap-ups on both delivery rolls 6 and 7 can occur. As experience has shown, this situation occurs relatively frequently after a yarn breakage has taken place at a spinning position and requires the performance of the requisite corrective action within the shortest time, otherwise the lap-up 55 continuously increases in size and eventually damages or even destroys the spinning position, for instance, by deforming the weighting arm of the drafting arrangement 3 or by bending the bottom delivery roll 6 and so forth. The very danger of formation of such lap-ups 55 up to the present time has required continuous surveillance of the ring spinning machine which, for instance, for the operating personnel working during the night shift, poses serious personnel problems. Fast and reliable detection of the working conditions prevailing as shown in FIG. 2d therefore is of primary importance, and it is to be remarked, can be advantageously guaranteed by the method described herein and the apparatus for the implementation thereof.
Now, as shown in FIG. 2d, even in the case of the formation of a lap-up 55, the yarn feeler 28 detects the absence of a yarn at the spinning position, and, as described with reference to FIG. 2c, the fiber stream-deflecting device 33 (FIG. 1) is immediately brought into its working position. Since here also no fiber stream 54 is present, no fiber stream is deflected into the suction tube 35. Hence, the fiber stream detector 34 (FIG. 1) does not transmit any signal to the control device 32'. If a signal is transmitted via the circuit line 32 and no signal is transmitted via the circuit line 43, then the control device 32' reaches the decision that a fiber lap-up 55 has formed and immediately initiates the corresponding control function and/or operating function. This function, for instance, as shown in FIG. 1, consists of the immediate stoppage of the supply of roving 2 to the drafting arrangement 3 by pivoting the roving clamping device 18 into the phantom line position of FIG. 1. Thus, further growth of the fiber lap-up 55 is beneficially prevented and the spinning position is accordingly protected against damage.
As will be apparent to one skilled in the art the electric circuits required for realizing the above-discussed control functions are well known to those acquainted with this technology, and therefore, need not here be further described since different control circuits, typically those using logic gates can be employed, and therefore do not require any further explanation.
It should be mentioned, however, that a similar situation can arise for the control apparatus 24, but without any danger as concerns the spinning position, if the reserve of fiber roving 2 which is creeled is exhausted or has already been interrupted. In this case, neither a yarn 15 nor a fiber stream 54, nor a fiber lap-up 55 are present. Also in this case the control apparatus 24 reacts as in the situation described above with reference to FIG. 2d, i.e., there is activated the roving clamping action, which however, for the assumed case, is ineffective. This action, however, is not totally futile, since the resulting position of the double-arm lever 20 visually flags or signals in a most easy manner to the patrolling monitoring or operating personnel the operating conditions which prevail at such spinning position.
Finally, in FIGS. 3a and 3b there are shown two further respective embodiments of fiber detectors 34 which are known as such, but can be beneficially utilized within the teachings of the present invention.
According to the showing of FIG. 3a, the fiber detector 34 which is here installed or built into the inner tube 37 consists of a light barrier formed by a light emitter 56 and a light receiver 57. The fibers of the deflected fiber stream 54' which move through the tube 37 partially interrupt the light beam 58, schematically represented by the indicated arrows. The light receiver 57 is therefore obscured and transmits a corresponding control signal via the circuit line 43, which is accordingly evaluated in the control device 32' as constituting a signal representative of the presence of a deflected fiber stream 54'. The use of light barriers for similar purposes is well known and has proven itself in practice. They only are associated with the drawback that there is present a certain danger of contamination, so that in certain instances there are resorted to the use of different types of fiber detectors.
A fiber detector 34 which is less susceptible to the danger of contamination by the action of a fiber and air stream, has been shown in the modified arrangement of FIG. 3b. This fiber detector 34 comprises a grid or sieve type collecting shield or screen 59 which collects the fibers, but permits the passage of the air. The collecting shield 59 is pivotably hinged on a hinge or pivot 60 in the tube 37 and in its working position is pressed against a stop 61 by any suitable means, such as for instance, a spring, so that the entire cross-sectional area of the tube 37 is covered, Now, if a fiber stream 54' is deflected through the suction tube 35, the sucked-off fibers are deposited onto the collecting shield or screen 59 and at that location form a fiber layer 62. Thus, the air can only continue to flow through the tube 37 in the presence of the increased resistance, which ultimately results in tilting or pivoting of the collecting shield 59 into the position indicated with broken or phantom lines in FIG. 3b. During this operation an extension or projection 63 of the collecting shield 59 contacts an activation pin 64 of an electrical switch 65, which when activated, closes a contact and transmits an appropriate signal via the circuit line or conductor 43, this signal again being classified in the control device 32' as constituting a signal representative of the presence of a deflected fiber stream 54'.
The method described herein for controlling or monitoring the operating conditions on a ring spinning machine affords at least the following noteworthy advantages:
(a) The method is applicable at any ring spinning machine equipped with a yarn suction system, without requiring alterations or modifications at its spinning positions. Thus, it is most suitable also for realizing an automatic control at a large number of ring spinning machines which have already been installed.
(b) The method enables accomplishing an absolutely reliable control or monitoring of the operating conditions at each spinning position of a ring spinning machine. The sequence of the checking or monitoring operations is chosen such that properly functioning spinning positions are disturbed as little as possible by the control apparatus, since upon determination of the presence of the yarn there is dispensed with any further checking or monitoring operation.
(c) The results of the monitoring or control operations can be evaluated in any desired and sensible manner in accordance with the objectives of the control or monitoring operations, and thus, there can be realized various degrees of automation which range from merely clamping the roving in the event of lap-up formation on a delivery roll, by signalling or visually flagging the operating conditions at the relevant spinning position, to the fully automatic operation of the spinning position using an automatic yarn piecing device.
Furthermore, the proposed apparatus for implementing the inventive method affords a number of significant advantages, some of the more notable ones of which are the following:
(a) A simple and inexpensive construction, since the equipment for detecting the presence of a fiber lap-up on the delivery rolls is only required once as part of the control or monitoring apparatus.
(b) There is not required any precise guiding of the control apparatus along the ring spinning machine, since the employed control elements are not absolutely tied, as concerns their functional reliability, to an exact positioning thereof.
(c) Extremely reliable operation, without any disturbance of the operating conditions at spinning positions which are functioning properly.
(d) The apparatus can be easily mounted onto any ring spinning machine which has already been installed.
While there are shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims.
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A method of, and apparatus for, consecutively controlling the operating conditions at a plurality of spinning positions or locations of a ring spinning machine, wherein there are detected yarn breakages and lap-up formations on rolls of the drafting arrangements. Upon detection of a yarn breakage at a predetermined spinning position the suction air stream of the suction system at such spinning position is rendered ineffectual at such spinning position of the ring spinning machine and such spinning position is checked for the presence of a fiber stream.
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This application claims benefit of Provisional Appln 60/046,500 filed May 14, 1997.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and an apparatus for developing a test strip, and more particularly a test strip having a reagent test pad requiring an incubation period for developing the desired test results disposed thereon.
2. Description of the Related Art
Test strips having a reagent test pad disposed thereon are conventionally known testing devices which are often used to determine whether a sufficient concentration of a chemical or chemicals is present in a solution. In the conventionally known procedure, the reagent test pad having reagent chemicals disposed thereon is placed in contact with a solution to be tested, typically by dipping the test strip in the solution. When the reagent test pad is sufficiently wetted, the test pad is removed from the solution and the indication on the test pad is examined after a predetermined waiting time. The reagent test pad is usually designed to change to a particular color or range of colors corresponding to the concentration of the chemicals in the solution being examined. In conventionally known procedures, the user places the wetted test pad in an open environment, such as on a lab bench, while waiting for the color change to develop.
Although simple to use, one consideration in using such test strips is the accuracy and reliability of the color indications developed on the reagent test pads. In conventional applications, a standardized chart showing various colors and corresponding concentrations is provided. To be effective and reliable, the test performed should always produce a color which corresponds to an accurate concentration of the chemical being tested. In other words, the person performing the test should be able to confidently match the color produced by the test strip with a corresponding color on the standardized chart and the concentration of chemical then taken therefrom.
Unfortunately, due to the imprecision inherent in any analytical tests, the desired indication may be observed at concentrations other than the predetermined concentration. For example, in a test producing a mere change in color at a given concentration, such color change could incorrectly occur at a concentration other than the given concentration. The concentration at which the test always reads "PASS" or "FAIL" is determined by the properties and conditions of the test. The difference in the 100% FAIL and the 100% PASS concentration may be called the "window". It is desirable to have the range of this window be as small as possible to ensure effective management and use of the solutions being tested, for example to ensure that only effective solutions are used and to ensure that effective solutions are not needlessly replaced.
The window may be narrowed in many tests by increasing the reaction time between the chemicals in the reagent test pad and the chemicals in the solution. This is most likely due to two factors associated with dry reagents tests, namely 1) the reactants on the test strip need time to completely dissolve, and 2) the diffusion of reactants in a solid matrix is very slow. However, because these reactions occur in aqueous solutions, the reaction time available for the test is limited by the evaporation of water from the reagent test pad. Accurate measurement within a narrow window is difficult if the moisture necessary to maintain the reagents in solution evaporates from the reagent test pad before the reaction is complete. This is particularly true when measuring highly concentrated analytes where the loss of even small amounts of water may cause precipitation of analytes and/or reactants within the test pad.
Conventionally known methods and apparatuses are limited in their ability to obtain accurate and reliable results within a narrow window because the water necessary to maintain the reagents in solution typically evaporates from the test pad before allowing a sufficient incubation period. This evaporation leads to improper use of ineffective solutions as well as wasteful replacement of effective solutions.
Therefore, what is needed is an accurate and reliable method and apparatus for using test strips described above wherein a sufficient incubation period is provided to allow the reagents to completely react with one another before the requisite moisture evaporates from the test pad.
SUMMARY OF THE INVENTION
The present invention is a method and an apparatus for providing accurate and reliable results from a test strip having a reagent test pad disposed thereon when the reagent test pad requires an incubation period for the reagents to react. The present invention also provides a more narrow window between PASS and FAIL indications which in turn allows effective use and management of the test solutions. The present invention achieves these results by placing and maintaining the reagent test pad in an enclosed, high humidity environment, in a substantially vertical orientation during the incubation period.
The method of the present invention comprises, in one form thereof, the steps of providing a test strip having a reagent test pad disposed on one end and a grip portion disposed on another end. The reagent test pad is wetted with a desired test material and placed in an enclosed chamber and after a predetermined waiting period, the results indicated on the reagent test pad are read. The enclosed chamber is advantageously adapted to provide a high humidity environment and the reagent test pad is advantageously maintained in a vertical manner in the enclosed chamber during the incubation period.
In another form, the present invention comprises a test strip holder of reagent test strips having a reagent test pad requiring an incubation period comprising a base and a cover, the base and cover adapted to fittingly engage each other to form an enclosed reaction chamber. The enclosed reaction chamber is adapted to store the reagent test pad. One of the base and cover includes a holding portion adapted to engage the test strip to thereby securely maintain the reagent test pad in the reaction chamber. One of the first and second holders includes a substantially clear portion allowing viewing of the test strip.
The present invention also comprises, in another form thereof, a combination comprising a test strip having a reagent test pad disposed thereon, the reagent test pad requiring an incubation period, and a test strip holder, the test strip holder comprising a base and a cover. The base and cover are adapted to fittingly engage each other to form an enclosed reaction chamber. The enclosed reaction chamber is adapted to receive and hold the reagent test pad and one of the base and cover includes a substantially clear portion allowing viewing of the reagent test pad.
Additionally, a test strip storage device may advantageously be provided for use with the test strip holder of the present invention wherein the test strip storage device includes a storage element disposed on a pedestal, the storage element having a plurality of recesses formed on a top surface thereof for placement of the test strip holders therein in a manner which allows the user to easily store the test strip holder and view the indication on the reagent test pad.
Therefore, it is an objective of the present invention to provide a method and an apparatus for accurately checking the concentration of a chemical in a solution using a test strip reagent pad.
It is also an objective of the present invention to provide a method and an apparatus for accurately checking the concentration of a chemical in a solution using a test strip pad having a reagent test pad which requires an incubation period.
It is also an objective of the present invention to provide a method and an apparatus which permits a reagent test pad to be vertically stored in a high humidity environment for a sufficient period of time to allow the reactants to fully react.
It is also an objective of the present invention to provide a method and an apparatus which allows a very narrow window between the 100% FAIL and the 100% PASS indications on the reagent test pad.
It is also an objective of the present invention to provide a method and an apparatus which accomplishes the above cited objectives in a simple, easy to use, economical manner.
It is also an objective of the present invention to provide a disposable or reusable apparatus which accomplishes the above cited objectives.
BRIEF DESCRIPTION OF THE DRAWINGS
The above mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of the embodiment of the invention taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a perspective view of an embodiment of a test strip holder of the present invention in the open position and a test strip having a reagent test pad disposed thereon;
FIG. 2 is a perspective view of a test strip placed in the test strip holder of FIG. 1 of the present invention which has been moved toward the closed position;
FIG. 3 is a perspective view of a test strip placed in the test strip holder of FIG. 1 of the present invention which is in the closed position;
FIG. 4 is a front elevational view of the test strip held in the test strip holder of FIG. 1 of the present invention;
FIG. 5 is a sectional view taken along line 5--5 of FIG. 4;
FIG. 6 is a perspective view of a storage device for storing test strip holders of the present invention;
FIG. 7 is a cross-sectional view of an alternative embodiment of the test strip holder of the present invention;
FIG. 8 is a perspective view of an alternative embodiment of a test strip holder of the present invention in the open position and a test strip having a reagent test pad disposed thereon;
FIG. 9 is a perspective view of a test strip placed in the test strip holder of FIG. 8 of the present invention which has been moved toward the closed position;
FIG. 10 is a perspective view of a test strip placed in the test strip holder of FIG. 8 of the present invention which is in the closed position; and
FIG. 11 is a cross sectional view along line 11--11 of FIG. 10.
Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the present invention. The exemplifications set out herein illustrate embodiments of the invention, in several forms, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
DETAILED DESCRIPTION OF THE INVENTION
The embodiments disclosed below are not intended to be exhaustive or limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize their teachings.
Referring now to FIGS. 1-5, test strip holder 10 of the present invention comprises base 12 and cover 14 which are integrally connected by flexible connection 32. Base 12 and cover 14 are configured and adapted to engage each other to form an enclosed reaction chamber for holding test strip 15. As particularly shown in FIGS. 1-2 and further described below, base 12 and cover 14 can pivot with respect to each other about the axis of flexible connection 32 in order to form sealed reaction chamber 50 which provides a high humidity environment for minimizing the evaporation of water from test strip 15 during the incubation period of the test. A typical test strip 15 suitable for use with test strip holder 10 includes reagent test pad 15a, grip portion 15b and middle portion 15c.
Base 12 comprises substantially rectangular back panel 25 having raised edge 16 disposed around the periphery thereof. Raised edge 16 is in a spaced apart relationship from the edge of back panel 25 along shoulder 18. Raised edge 16 comprises outer sidewalls 20, top wall 22, and inner sidewalls 24. Rounded corner portions 23 are disposed along the four comers of raised edge 16 and interconnect the linear portions of raised edge 16. Back panel 25 in combination with raised edge 16 define recessed space 26. As described further below, recessed space 26 is used in combination with recessed space 46 of cover 14 to form reaction chamber 50. Also, indentation 28 is disposed on a lower portion of raised edge 16. Indentation 28 is adapted to fittingly receive test strip 15 and maintain test strip 15 in a vertically held position after base 12 and cover 14 have been joined. Thus, in the present embodiment, indentation 28 comprises a holding portion for test strip 15. Although the present embodiment uses a notched arrangement as a holding portion for test strip 15, it is to be understood that any conventionally known method for securely holding test strip 15 in holder 10 may be used, for example raised portions on base 12 or cover 14 as described hereinbelow, or adhesive elements disposed on base 12 or cover 14.
Back panel 25 further includes handle 30 disposed at a lower end thereof to provide an easy handling mechanism for the user. It is to be understood that although handle 30 is only on one comer of back panel 25, other handling mechanisms may be placed in many locations around back panel 25 to facilitate the handling of back panel 25.
Cover 14 is integrally connected with base 12 via flexible connection 32 and is adapted to fittingly engage base 12. As shown in FIGS. 1-3, cover 14 comprises front panel 36 which is integrally joined with flat edge portion 34 via sidewalls 38, flat portion 40 and rounded shoulder portion 39. The combination of front panel 36, rounded shoulders 39, sidewall 38, and flat portion 40 defines recessed space 46. Straight line portions of sidewall 38 are joined by rounded comers 33 and straight line portions of rounded shoulder 39 are joined by rounded comers 43. Front panel 36 included handle 31 to provide an easy handling mechanism for the user. Front panel 36 is made of a relatively clear, see-through plastic, such that a user can easily look through front panel 36 to check the indication on reaction portion 15a of test strip 15.
The dimensions of raised edges 16, particularly rounded portions 23, and sidewalls 38, particularly comer portions 43, are sized and adapted to fittingly engage each other such that base 12 and cover 14 snap tight. It is to be understood that any conventionally known method for achieving a snap tight engagement of base 12 and cover 14 may be used, for example, the area encompassed by outer sidewall 20 may be slightly larger than the are encompassed by sidewall 38, or rounded comers 23 may bulge out slightly wider than the inside areas of rounded comers 33, or sidewall 38 and sidewall 20 may fittingly contact each other and outer movable snaps may be placed on the edges of flat portions 18 or 34 to achieve the snap tight engagement.
The snap tight engagement of base 12 and cover 14 combines recessed spaces 26 and 46 to form enclosed chamber 50. Enclosed chamber 50 is sealed sufficiently to provide a high humidity environment for minimizing water evaporation from reagent test pad 15a while holding test strip 15 for a required incubation period.
With reference to FIG. 6, test strip holder 10 is advantageously used in combination with holder device 60 which can be used for storing and maintaining a plurality of test strip holders 10 in a vertical position while waiting for an indication to develop on test strip 15. Holder device 60 is a receptacle comprising top wall 61 and sidewalls 62 disposed on pedestal 70. Recesses 64 having inner walls 66 are disposed in top wall 61 to receive and hold test strip holder 10. Recesses 64 are oriented along the length of top wall 61 and have a depth wherein clear front panel 36 of a test strip holder 10 placed therein can be easily viewed by a user. Also, notches 68 are disposed along the ends of inner walls 66 to facilitate the insertion of test strip holder 10 into recess 64. It is to be understood that although holding device 60 shown in FIG. 6 comprises three recesses 64, it is possible to have holding device 60 which includes any suitable number of recesses 64, aligned as desired to provide easy viewing of front panel 36 by the user.
The method for using test strip 15 with test strip holder 10 to test for the concentration of in a test solution is now described. The user initially holds grip portion 15b and dips reagent test pad 15a into the test solution and then withdraws reagent test pad 15a from the test solution after reagent test pad 15a has been sufficiently wetted. Test strip 15 is then transferred to test strip holder 10 and held against test strip holder 10 by placing intermediate portion 15c against indentation 28 of base 12. While continuing to hold intermediate portion 15c against indentation 28, the user rotates cover 14 about the axis of pivot connection 32 until the associated surfaces of base 12 and cover 14 come in contact with each other. The user then snaps together base 12 and cover 14 to form enclosed reaction chamber 50 and to thereby secure test strip 15, particularly reagent test pad 15a, therein. At this point, reaction portion 15a is vertically disposed inside enclosed chamber 50 which maintains a high humidity environment for minimizing the evaporation of water from reagent test pad 15a.
The vertical alignment of test strip 15 allows excess solution on reagent test strip pad 15 to fall off test pad 15 by gravity to provide more consistent test results. Previously, excess solution on a reagent test pad formed a bead which was removed by either shaking off the excess or blotting the test pad with an absorbent material. In either method, the amount of solution which was removed from the test pad varied greatly such that the test results also varied greatly. Storing test strip holder 10 in a vertical position obviates this problem as the excess solution falls off test pad 15 by gravity flow and a consistent amount of solution remains on test pad 15, thereby resulting in more consistent results.
Once test strip 15 has been secured onto test strip holder 10 as described above, the user may continue to hold test strip holder 10 in a vertical position until the incubation period has elapsed or may place and store test strip holder 10 in holder device 60. To place test strip holder 10 in holder device 10, the sides of test strip holder 10 are aligned with notches 68 of recess 64 and test strip holder 10 is slidingly placed into recess 64. Holder device 60 or equivalent may be aligned to face the user to facilitate the reading of the indication on reagent test pad 15a. In this manner, test strip holder 10 is maintained in a vertical position and front panel 36 faces outward such that the user can readily observe any color changes on reagent test pad 15a.
Once the test is completed, the entire assembly may be discarded without the user coming in contact with the test solution or the reagent test pad. In this manner, the present method and apparatus facilitates the disposal of the test products.
An alternative embodiment of the present invention is shown in FIG. 7 wherein clear tube 80, for example a test tube, serves as a cover and stopper 82 provides a base. In combination, tube 80 and stopper 82 provide a sealed, high humidity chamber for developing a reagent test pad. In the embodiment shown in FIG. 7, slot 84 is disposed on stopper 82 for holding test strip 15 in a vertical manner during the incubation period. Here, end portion 15b of test strip 15 is inserted into slot 84 and then stopper 82 is partially inserted into open end 86 of test tube 80 to form enclosed reaction chamber 90 for holding reagent test pad 15a therein. Once test strip 15 has been placed in tube 80, tube 80 may be left in the vertical position until the incubation period has elapsed. The user can then easily view any indication changes on reagent test pad 15a through tube 80.
An alternative embodiment of the present invention is shown in FIGS. 8-11 wherein test strip holder 200 comprises base 212 and cover 214 which are integrally connected by flexible connection 232. Base 212 and cover 214 are configured to engage each other to form an enclosed reaction chamber for holding test strip 15. As particularly shown in FIGS. 8-9 and further described below, base 212 and cover 214 can pivot with respect to each other about the axis of flexible connection 232 in order to form sealed reaction chamber 250 which provides a high humidity environment for minimizing the evaporation of water from test strip 15 during the incubation period of the test. Base 212 comprises bottle-shaped back panel 225 having raised edge 216 disposed around the periphery thereof. Raised edge 216 is spaced apart from the edge of back panel 225 along shoulder 218. Raised edge 216 comprises outer side walls 220, top wall 222 and inner side walls 224. Rounded comer portions 223 are disposed along the four outside comers of raised edge 216. Back panel 225 in combination with raised edge 216 define recessed space 226. Recessed space 226 combined with recess space 246 in cover 214 form reaction chamber 250.
Indentation 228 is disposed on the lower portion of raised edge 216 as shown in FIG. 8. As shown in FIGS. 9-11, indentation 228 is adapted to fittingly receive test strip 15 in a vertically held position. With reference to FIGS. 8 and 11, tab portion 229 extends from flat portion 240 of cover 214 so that when the test strip holder is closed, as shown in FIGS. 10 and 11, tab 229 serves as a holding portion to hold test strip 15 securely in place in apparatus 200. That is, tab 229 abuts against test strip 15 when cover 214 and base 212 are sealingly engaged as shown in FIG. 11.
Back panel 225 further includes handle 230 disposed at a lower end thereof to provide an easy handling mechanism for the user. Similarly, cover 214 includes handle portion 231 at a lower end thereof to provide an easier handling mechanism for the user.
Cover 214 is integrally connected with base 212 via flexible connection 232 and is adapted to fittingly engage base 212. As shown in FIGS. 8-10, cover 214 comprises front panel 236 which is integrally joined with flat edge portion 234 via sidewalls 238 and flat portion 240. A combination of front panel 236, sidewall 238 and flat portion 240 defines recess space 246. Front panel 236 is made of a relatively clear, see-through plastic, such that a user can easily look through front panel 236 to check the indication on reaction portion 15a of test strip 15. The dimensions of raised edges 216, particularly rounded portions 223, and sidewalls 238 and corner portions 233 on cover 214 are sized and adapted to fittingly engage each other such that base 212 and cover 214 snap tightly together. The snap-tight engagement of base 212 and cover 214 combines recessed spaces 226 and 246 to form enclosed chamber 250 as shown in FIG. 10.
It can be seen in the above-described embodiments that a reaction chamber for holding a reagent test pad may be provided in a simple, easy to use, disposable and economical package. It is also obvious that the apparatus may be easily manufactured using a number of inexpensive materials, including, but not limited to plastic, and a number of conventionally known processes.
The use of an enclosed reaction chamber in tests using test strips having an incubation period is effective in producing accurate test results. One test where such a method and apparatus was shown to be particularly effective is the test for determining the active concentration in chemical germicides. A typical use for chemical germicides is to disinfect or sterilize endoscopes which contain heat-sensitive optical systems. Many of the chemical germicides are reusable and used for sequential loads of instruments until the active ingredient becomes too dilute to be effective against microorganisms. Depletion of the germicide can result from dilution or chemical inactivation. The lowest concentration at which the active ingredient in the germicide will kill all test microorganisms is termed the Minimum Effective Concentration ("MEC"). The germicide is routinely tested to avoid using solutions containing less than the MEC because such solutions are ineffective.
To ensure that an ineffective solution is never used, the test should always show FAIL at the MEC. However, due to the imprecision inherent in any analytical test, FAIL results may be observed at concentrations greater than the MEC. The concentration at which the test always reads PASS is determined by the properties of the test. The difference in the 100% FAIL and the 100% PASS concentrations is the "window". It is desirable to have the window size be as small as possible to ensure that the germicide is effective and that effective germicide is not needlessly replaced. If the test frequently indicates FAIL when the disinfectant level is above the MEC, the germicide will be replaced more often than necessary.
A dry reagent test strip may be used to measure the level of the active ingredient, hydrogen peroxide, in a reusable germicide solution, for example, SPOROX®, manufactured by Reckitt & Coleman, Inc. of Montvale, N.J. The test strip comprises a reagent-containing test pad (the "indicator pad" or "pad") attached at one end of a polystyrene handle.
The chemistry of the test strip is based on the reduction of the hydrogen peroxide with a fixed amount of sulfite ion in the presence of iodide and starch. When the hydrogen peroxide concentration is 6.0% or less, it is entirely consumed by the sulfite. When its concentration is sufficient to overwhelm the reducing agent, the excess oxidizes the iodide to iodine producing a dark brown/black color in the presence of starch. The chemical reactions include the following:
H 2 O 2 +Iodide→Iodine+H 2 O
Iodine+Sulfite→Iodide
Excess H 2 O 2 +Iodide→Iodine+H 2 O
Iodine+Starch→Starch-Iodine Complex (Brown/Black)
It has been determined that the smaller the window, the longer the reaction period needs to be. This is most likely due to two factors associated with dry reagent tests: 1) the reactants supplied by the strip need time to completely dissolve; and 2) the diffusion of reactants in a solid matrix is very slow.
Thus, the window can be narrowed by increasing the reaction time. However, unless evaporation of water from the pad is prevented, there is an upper limit to the reaction time. A typical filter paper matrix absorbs about 0.25 ml per square inch. This means that the sample exists as a layer of about 0.5 mm thickness. The high surface area to volume ratio results in a very high relative evaporation rate. Accurate measurement is impossible if significant amounts of water evaporate from the pad prior to completion of the analytical reaction. This is particularly true when measuring highly concentrated analytes when the loss of even small amounts of water may cause the precipitation of analyte and/or reactants within the pad.
Two separate sets of tests were performed to demonstrate the effectiveness of the present invention. In the first set of tests, the test strip was developed with the reagent test pad placed in a reaction chamber. In the second set of tests, the test strips were developed with the reagent test pad left in the open.
To run the first set of tests, the test pad was dipped into the sample for a period of five seconds, removed and then placed in a vertical position with the test pad up. A reaction chamber was placed over the strip to prevent evaporation of water from the test pad. After a reaction period of 12 to 15 minutes, the color of the test pad was observed. If the solution contains 7.0% or more hydrogen peroxide, the test pad will be completely brown/black indicating a PASS result. If the solution contains 6.0% or less hydrogen peroxide, a white area will appear in the center of the test pad indicating a FAIL result. At intermediate concentrations, the strip may indicate either PASS or FAIL.
The relationship between hydrogen peroxide concentration and time to develop the FAIL result when using an enclosed reaction chamber are summarized as follows:
TABLE 1______________________________________Effect of Hydrogen Peroxide Concentrationon Time Required to Develop FAIL ResultStrips protected from evaporationHydrogen Peroxide Concentration Time to Develop FAIL result(%) (mean ± s.d., n = 10)______________________________________5.6 8.3 ± 0.76.0 12.0 ± 0.86.6 18.9 ± 2.67.0 all > 25______________________________________
Based on the above, distinguishing 5.6% from 7.0% hydrogen peroxide would require a 10 minute wait, 6.0% from 7.0% a 14 minute wait and 6.6% from 7.0% a 25 minute wait. These wait times were calculated by adding 2 s.d. to the mean.
The relationship between hydrogen peroxide concentration and time to develop the FAIL result without using the enclosed reaction chamber was determined to be as follows:
TABLE 2______________________________________Effect of Evaporationon Strip Reaction Strips not Protected from EvaporationHydrogen Peroxide Concentration Time to Develop FAIL result(%) (mean ± s.d., n = 10)______________________________________5.6 18.1 ± 4.06.0 all > 256.6 all > 257.0 all > 25______________________________________
The results of Table 2 indicate that it would not be possible to distinguish 5.6% from 7.0% hydrogen peroxide all of the time and that it would never be possible to distinguish either 6.0% or 6.6% from 7.0%. Thus, a comparison of the two sets of test results indicates that the use of a reaction chamber to prevent water evaporation from the reagent test pad improves the strip precision considerably.
Other tests that have extended reaction times will benefit from the use of a container to prevent sample evaporation. Therefore, other test strips which may be advantageously used with the method and apparatus of the present invention include, but are not limited to, Serim DisIntek Strips for 1.0-2.5% glutaraldehyde in endoscope disinfection baths, Serim Formaldehyde Reagent Strips for 4% formaldehyde in hemodialyzer disinfectant, Serim Formaldehyde Reagent Strips for 1-2% formaldehyde in hemodialyzer disinfectant, Serim Glutaraldehyde Reagent Strips for 0.8% glutaraldehyde in hemodialyzer disinfectant, Johnson & Johnson Cidex® Solution Test Strips for 1.5-2.5% glutaraldehyde in Cidex® Activated Dialdehyde Solution, Johnson & Johnson Cidex® Plus Solution Test Strips for 1.5-3.4% glutaraldehyde in Cidex® Plus Activated Dialdehyde Solution, and Wavicide-01® Solution Test Strips for glutaraldehyde in Wavicide-01® disinfecting and Sterilizing Solution.
While this invention has been described as having an exemplary design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. For example, a clear straw or other similar tubular devices which may be held in vertical position and which reduce the evaporation of water from reagent test pad 15a may be used to provide a reaction chamber. Also, although the test strip holder of the present invention uses generally rectangular bases, it is to be understood that any shapes may be used, as long as the segments allow a snap tight engagement to form an enclosed reaction chamber for vertically holding a test strip therein. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.
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A test strip incubation device and method for developing a test strip having a reagent test pad disposed thereon, the reagent test pad requiring an incubation time, which allows greater accuracy and reliability of test results as well as a narrower window of PASS and FAIL indication concentrations. The device comprises a test strip holder which allows a wetted reagent test pad to be vertically stored in an enclosed reaction chamber during the incubation period. The reaction chamber is bounded by a substantially clear material to allow the user to easily observe the status of the reagent test pad held in the reaction chamber. The enclosed reaction chamber provides a high humidity environment for minimizing water evaporation from the reagent test pad during the incubation period. The device may be economically formed from low cost materials, is simple to use and facilitates disposal of the sample material after testing. The device is advantageously used in combination with a storage device which includes recesses for easy storage of several devices and allows viewing of the reagent test pads. The method comprises the steps of wetting the reagent test pad and vertically placing the reagent test pad in an enclosed reaction chamber during the incubation period. The enclosed reaction chamber provides a high humidity environment for minimizing the evaporation of water from the reagent test pad.
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RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 12/537,891, filed Aug. 7, 2009, entitled Method for Improving Peer to Peer Network Communication, which is a continuation of U.S. application Ser. No. 11/040,364, filed Jan. 21, 2005, now U.S. Pat. No. 7,583,682, entitled Method for Improving Peer to Peer Network Communication, which is a continuation of U.S. application Ser. No. 10/764,111, filed Jan. 23, 2004, now U.S. Pat. No. 7,761,569, entitled Method for Monitoring and Providing Information Over a Peer to Peer Network.
The entire teachings of the above application(s) are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention provides a method for improving peer to peer network communications, and, in particular, to connecting one or more peer to peer networks together and accepting communication messages from a node and providing the communication message to another node. The present invention may also change communication message radius parameters to increase the communication message radius of travel on the network.
BACKGROUND OF THE INVENTION
As used herein, peer to peer networks which are the subject of the present invention comprise multiple nodes, each node typically consisting both of file server and client, which can send and receive data or “communication messages” to or from a node to which such is connected.
In a peer to peer network, each node is connected to other nodes over a communication medium, such as the internet, either directly or through some type of proxy. For example, when a search request is issued, such originating node sends a search request to all of the nodes to which it is connected (see FIG. 1 ). These nodes search their list of available files and if a match is found they send a response back with the location. However, a peer to peer proxy network typically consists of a node A which is connected to a node B and node B is connected to a node C (see FIG. 2 ). Node A is not directly connected to node C such that if node A issues a search request it will be forwarded to node B to search its available files, and if a match is found it will send a response back to node A. Node B will then forward node A's request to node C and node C will search its available files and if a match is found it will send a response back to node B. Node B will then forward this response to node A. FIG. 3 depicts a non-proxy loop network wherein each node is directly connected to another.
Some peer to peer networks utilize a leaf node/main node proxy topology (see FIG. 4 ) where some nodes are classified as main nodes and the remaining nodes are classified as leaf nodes. Leaf nodes can only connect to main nodes. Only main nodes can connect to other main nodes. When a leaf node issues a search request, it sends the request to the main node with which it is connected. The main node then forwards the request to any other leaf nodes that are connected to it and also to any main nodes to which it is connected. These main nodes forward the request to any leaf node that are connected to them.
In peer to peer networks, communication messages are sent to the nodes to which they are connected and, in turn, each of those nodes send communication messages to other nodes to which they are connected.
Multiple peer to peer networks exist, usually each having a preferred set of attributes. Users wishing to utilize one peer to peer network for its specific attributes must install specific software to access a specific network. Often users wish to access multiple networks and therefore have multiple software applications installed on their computer. When the user wishes to search a specific network, the user must start the specific software application and initiate the search. If the result is not satisfactory, the user must launch a second application and search a second peer to peer network. Thus, it would be advantageous if users could search one network using the software application of their choice and have their communication messages be forwarded to a second network automatically.
Referring to FIG. 9 , a peer to peer network is depicted, but which is normally quite large. Often these networks comprise hundreds of thousands of nodes. To reduce the bandwidth required to operate such networks, nodes have a community imposed transmission distance or “Radius” limitation. Communication messages contain communication message radius parameters such as “hops” and time to live. Hops is a value that normally starts at 0 and increments each time the communication is forwarded. Time to live is a value that normally starts at 5 and is decremented each time the communication is forwarded. When hops reaches a preset limit, often 5, or time to live reaches 0, the communication is dropped from the network. Often nodes have a “Max time to live” setting. This value is typically set to 5. If a node receives a communication message time to live, which is higher than its configured max time to live, the packet is either dropped or the communication message time to live is dropped to the configured value in the max time to live. This effectively enforces a community time to live value and limits the number of nodes that would perceive communication message from a transmitting node. It would be advantageous if the communication message could travel some distance and then have its communication message radius parameters changed to an optimal or near optimal value to increase the distance the communication message could travel. For instance, a communication could travel 4 hops and then have its settings changed back to 0.
Accordingly, it is an object of the present invention to provide a method for improving peer to peer network communications. It is yet another object of the present invention to connect two or more peer to peer networks together and accept communication messages from one and provide it to another. It is yet another object of the present invention to accept communication messages from a peer to peer network and change the communication message radius parameters to an optimal or near optimal value and retransmit the communication message so that the radius or distance of the communication is extended.
SUMMARY OF THE INVENTION
Generally, the present invention provides a method for improving peer to peer network communications by utilizing at least one of the methods set forth below. The preferred method comprises:
For example, at least one improvement-node is placed into a peer to peer network. An improvement-node (a) may optionally connect a second time to the same or different peer to peer network; (b) may accept communication messages from one network and forwarding it to the same or another network, optionally setting the communication message radius parameters to an optimal or near optimal value. Additionally, the improvement-node may accept communication messages from one network and compare it to a set of definitions to make a decision to drop or forward the communication message. It may optionally set the communication message radius parameters to an optimal or near optimal value and forward the communication message.
Thus, the present invention provides a method for connecting one or more peer to peer networks together and accepting communication messages from one and providing it to another. The invention does not require that all communication messages be forwarded or that the improvement-node connect to multiple networks. In one such embodiment, the improvement-node only forwards search and search response communication messages while not forwarding other communication messages. In another embodiment, the improvement-node connects to the same network and accepts communication messages, changes the communication messages radius parameters to an optimal or near optimal value and resends it on the same network. In another embodiment, the improvement-node accepts all communication messages and forwards all communication messages. In another embodiment, the improvement-node accepts communication messages from one network and uses preconfigured information to decide if it should forward it on to another network. In yet another embodiment, the improvement-node accepts communication messages from a node on a network and issues new communication messages containing the same information onto the same network or different network on behalf of the original node.
In all of the embodiments, the improvement-node is configured to have one or more of the features set forth below. These features are employed in the method for improving peer to peer network communication to provide enhanced capabilities compared to the network nodes in the particular network being addressed. Thus, not all of the capabilities need to be programmed into each improvement-node in order to accept and forward communication messages. The presently preferred configurations include:
The improvement-node is configured to connect the same network multiple times. The improvement-node is configured to connect to multiple networks. The improvement-node is configured to connect to multiple networks multiple times. The improvement-node is configured to accept communication messages from one network and forward it to another. The improvement-node is configured to accept communication messages from one network, changes communication message radius parameters, and resends the communication message on another network. The improvement-node is configured to accept communication messages from one network, change the communication message radius parameters, and resends the communication message on the same network. The improvement-node is configured to make a decision to forward a communication message based on preprogrammed configuration. The improvement-node is configured to make a decision to change communication message radius parameters based on a preprogrammed configuration. The improvement-node is configured to accept communication messages from one node, create new communication messages with the same information except changing the identification information to that of its own, forward the new communication messages on to the same or different network, receive responses to said new communication messages and forwarding response of new communication messages to the original node. The improvement-node is configured to speak multiple protocols. The improvement-node is configured to bridge together multiple networks. The improvement-node is configured to route one network to another. The improvement-node is configured to repeat a communication message to extend its distance of travel.
Other advantages of the present invention will become apparent from a perusal of the following detailed description of presently preferred embodiments of the invention taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing will be apparent from the following more particular description of example embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments of the present invention.
FIG. 1 is a simplified schematic of a two node peer to peer network;
FIG. 2 is a simplified schematic of a peer to peer proxy network;
FIG. 3 is a simplified schematic view of a peer to peer, non-proxy, and loop network;
FIG. 4 is a simplified schematic of a peer to peer leaf/main node network;
FIG. 5 is a flowchart representation of the programming or configuring an improvement-node to connect two networks together;
FIG. 6 is a flowchart representation of the programming or configuring an improvement-node to change the communication message radius parameters to an optimal or near optimal value;
FIG. 7 is a simplified schematic of two peer to peer networks being connected together via an improvement-node;
FIG. 8 is a simplified schematic of an improvement-node being used to reset communication message radius parameters;
FIG. 9 is a simplified schematic of a large peer to peer network.
DETAILED DESCRIPTION OF THE INVENTION
A description of example embodiments of the invention follows.
With reference to FIGS. 7 and 8 , the preferred methods of the present invention advantageously utilize at least one improvement-node. The improvement-node has certain preferred attributes and these attributes are configured for the specific type of communications improvement desired by the user.
In one preferred embodiment of the present invention, an improvement-node comprises both a hardware system such as a computer, thin appliance, ASIC based device or other similar device, which can be programmed with specific logic or programming code (i.e., software). In the preferred embodiments, the device preferably has a capability of being connected with a physical network either directly or through the use of gateway. The programming logic provides the device with the capability to transmit and receive on both physical networks as well as the peer-to-peer networks, which typically ride on top of the physical network. In the preferred embodiment of the invention, programming logic is a software program, but may also be hard coded non-changeable procedural information such as typically found in a ASIC based device.
Referring generally to FIG. 5 , a flow chart discloses one method for the programming logic that configures a device acting as improvement-node to attached to two peer networks. This improvement-node accepts communication messages from nodes participating on one network and forwards them onto another network.
Referring generally to FIG. 6 , a flow chart discloses one method for the programming logic that configures a device acting as a improvement-node to attach to the same peer-to-peer network twice. This improvement-node accepts communication messages from nodes participating on the network, changes the communication message radius parameters and forwards the communication messages onto the same network.
It may be advantageous to prevent transmission of communications from one network to the other, for instance, if the operator of the improvement-node was trying to prevent copyright infringement requests from transversing the networks. In this case, the programming logic can be configured to receive communication messages and compare them to criteria and to then perform some event whether or not a match is found. The programming logic may elect to drop the communication message and not pass it on to other networks. This election can be automatic depending on trigger points such as load or it can be configured to do so by the user of the programming logic.
The method for comparing may include inter-string, complete string, partial string, fuzzy logic, patricia-tree, or any other method that could be used to compare the likeness of two or more strings or portions of two or more strings. String comparison can occur in parallel with other searches to increase through-put or they can be compared serially (meaning one after another). If a match is made, the programming logic can drop the communication message if it is programmed to do so.
In one such embodiment, the improvement-node only forwards search and search response communication message while not forwarding other communication messages. In this embodiment, the improvement-node would accept the communication message, it decides if it is a search or response to a search, and then forward on or drop the communication message based on its findings. In another embodiment, the improvement-node is functioning as a “repeater” so the communication message can travel further on the network than it normally would. In this case, the improvement-node would accept the communication message from a node or network and set the communication message radius parameters to an optimal or near optimal value and retransmit the communication message.
In another embodiment, the improvement-node accepts all communication messages and forwards all communication messages. In this embodiment, the improvement-node would accept all communication messages from one network and forward it to another network.
In another embodiment, the improvement-node accepts communication messages from a node and makes a request onto the same network or a different network on behalf of the node. This would be used for caching environment or in an environment where the original node wish to hide its identity. The node would issue a communication message, which the improvement-node would accept. The improvement-node would replace original communication message with one of its own, making it appear as though it is sending the communication message for the benefit of itself. The improvement-node would maintain a table of node communication messages to “on behalf of” communication messages. As communication messages or services were returned to the improvement-node, the improvement-node would look in this table for a correlation. It would then forward the communication messages or services to the original node.
EXAMPLES
The following examples illustrate various embodiments to the methods according to the present invention.
Example 1
Referring to FIG. 7 , this example illustrates a method for connecting two networks together, accepting communication messages from one, and forwarding to another.
In this example, nodes A, B, and C are on a first network and nodes E, F, and G are on a second network. Each network is unable to communicate with each other because they speak different protocols. Node D is an improvement node and is part of both networks and speak both protocols. Node A searches for a file named “A” and sends the search request to nodes B and C. Nodes B and C accept this search request. Node C forwards the search request to node D. Node D accepts the search request and forwards it to node E. Node E accepts the search request and forwards it to nodes F and G. Nodes F and G accept the search request. All nodes process the search request. Node G finds that it has the file and sends a response to node E. Node E forwards this response to node D. Node D forwards this response to node C. Node C forwards this response to node A. Node A receives the response from node G, which is on another network.
Example 2
Referring to FIG. 8 , this example illustrates the method for accepting communication messages from nodes participating on a single network, changing the communication message radius parameters, and forwarding the communication messages onto the same network.
In this example, all nodes are on one network and node C is an improvement-node and is configured to accept any communication messages, change the communication message radius parameters to an optimal or near optimal value and retransmit the communication messages.
Node A is configured to send a search request no further than three hops away from where it is connected into the network. It sends a search to node B. Node B accepts the search in increments its hop value to 1 and forwards to node C. Node C accepts the search and resets the hop value to 0 and forwards the search to node D. Node D accepts the search and increments its hop value to 1 and forwards the search the node to E. Node E receives the search and increments its hop value to 2 and forwards the search to node F. Node F accepts the search. All nodes process the search request. Node F finds it has the file and generates a response with a hop value of 0 and sends the response to node E. Node E accepts the response and increments the hop value to 1 and forwards this response to node B. Node D accepts the response and increments the hop value to 2 and forwards the response to node C. Node C accepts the response and changes the hop value to 0. Node C forwards the response node B. Node B accepts the response and increments the hop value to 1 and then forwards the response to node A. Node A accepts the response. The end result is that even though node G was 5 hops away, it was still able to communicate with node A.
Example 3
Referring to FIG. 7 , example 3 illustrates the method for connecting two networks together, accepting communication messages from one, comparing to a list of criteria and dropping the communication message if it matches or forwarding it if it doesn't. In this example nodes, A, B, and C are on a first network and nodes E, F, and G are on a second network. Each network is unable to communicate with each other because they use different protocols. Node D is an improvement-node and is part of both networks and can operate with both protocols. Node D is configured to drop searches for “madonna.txt”. Node A searches for file name “madonna.txt” and sends this search request to nodes B and C. Nodes B and C accept the search request. Node C forwards the search request to node D. Since node D is configured to drop searches that match “madonna.txt” and because node A searches for “madonna.txt” node D drops the search.
Node A then searches for a file named “A” and sends this search request to nodes B and C. Nodes B and C accept the search request. Node C forwards the search request to node D. Since node D is configured to drop searches for “madonna.txt” and because node A searched for “A,” node D forwards the search request to node E. Node E accepts the search request and forwards it to nodes F and G. Nodes F and G accept the search request. All nodes process the search request. Node G finds that it has the file and sends a response to node E. Node E forwards the response to node D. Node D forwards this response to node C. Node C forwards this response to node A. Node A receives the response from node G which is on another network.
Example 4
Again, referring to FIG. 7 , example 4 illustrates a method for connecting two networks together, accepting communication messages from one, and forwarding not only searches and search responses and nothing else to another network.
In this example, nodes A, B, and C are on a first network and nodes E, F, and G are on a second network. Each network is unable to communicate with each other because they use different protocols. Node D is an improvement-node and is part of both networks and communicates with both protocols. Node A searches for file name “A” and sends this search request to nodes B and C. Nodes B and C accept this search request. Node C forwards the search request to node D. Node D accepts this search request and forwards it to node E. Node E accepts this search request and forwards it to node F and G. Nodes F and G accept the search request. All nodes process the search request. Node G finds that it has the file and sends a response to node E. Node E forwards the response to node D. Node D forwards this response to node C. Node C forwards this response to node A. Node A receives the response from node G which is on another network.
Node A then sends a ping request to nodes B and C. Node B receives the request and responds. Node C receives the request and responds. Node C forwards the ping request to node D. Because node D is configured to only forward search requests and responses, it accepts the ping and responds, but it does not forward the ping.
Example 5
Referring to FIG. 7 , example 5 illustrates the method for accepting communications from a node on a first network and forwarding the communications on to a second network while making it appear that the original communications came from the improvement-node when, in fact, it did not. For this example, refer to FIG. 7 .
In this example, node D is the improvement-node. Node C wishes to locate the file name “X” and sends the search request to node D. Node D accepts the search request and creates a new request with the same search terms, but with its own address information. Node D stores this request in a table so that it knows that if any requests are received, it should forward them to a node C. Node D forwards this request to node E. Node E accepts the search request and finds it has a match. Node E generates a response with node D's address information and forwards the response to node D. Node D accepts the response and looks in it's tables and finds that this response was meant for node C so it forwards this response to node C.
While presently preferred embodiments of the invention have been shown and described, the invention may be otherwise embodied within the scope of the appended claims.
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The present invention relates to a node for deployment on a peer to peer network. The node is programmed for monitoring the network to receive communication messages therefrom and to forward the communication messages, optionally changing the communications radius parameters to an optimal or near optimal value. The node can forward messages from one network to another or from one network to the same network. The invention also provides a method for monitoring communication messages for selected objects by nodes on a peer to peer network. The method includes interposing the node on the network. The node has at least one stored object corresponding to a communication message object stored the node; and monitors the network to detect communication messages matching at least one of the stored objects and decides whether or not to forward or change communication message radius parameters based on some defined programming or configuration.
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BACKGROUND OF THE INVENTION
The present invention relates to a portable terminal apparatus for an IC card which selectively reads and displays various transaction data, amount data, and the like from an IC card used as, e.g., a credit card and electronic money and supporting a plurality of applications.
In recent years, IC cards which incorporate IC chips having nonvolatile memories and control elements such as CPUs (Central Processing Units) for controlling the memories have been utilized as portable storage media in various industrial fields.
When an IC card of this type is used as, e.g., a credit card and electronic money, it is very convenient to selectively read and display various transaction data, amount data, and the like stored in the IC card, as needed.
For this purpose, a portable terminal apparatus for an IC card that the user can always carry has recently been developed. This portable terminal apparatus for an IC card is formed into a card-like shape, similar to the IC card, and comprises a keyboard, a liquid crystal display section, and a battery for a self-operation and a power supply of the IC card. Upon insertion of the IC card, various transaction data, amount data, and the like are selectively read from the IC card in accordance with a keyboard operation, and displays them on the liquid crystal display section.
Conventionally, such a portable terminal apparatus for an IC card copes with only a single application.
Since the above-mentioned conventional portable terminal apparatus for an IC card copes with only a single application, when data are to be read from an IC card which supports a plurality of applications, dedicated portable terminal apparatuses for an IC card are required for the respective applications.
When data are to be read from the IC card, it is impossible to determine whether key collation is necessary to read the data.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to provide a portable terminal apparatus for an IC card which is compatible with a plurality of applications and can automatically determine whether key collation is necessary in reading data from the IC card.
According to the present invention, there is provided a data processing apparatus for an integrated circuit medium, comprising: means for receiving and accessing the integrated circuit medium storing data; first processing means for performing data processing for the integrated circuit medium on the basis of a first application; second processing means for performing data processing for the integrated circuit medium on the basis of a second application different from the first application; means for inputting an instruction concerning data processing of the integrated circuit medium; means for selecting one of the first processing means and the second processing means in accordance with the instruction input from the input means; and means for controlling one of the first processing means and the second processing means which is selected by the selecting means so as to perform data processing.
With the above arrangement, the present invention provides a portable terminal apparatus which is compatible with a plurality of applications, unlike a conventional apparatus for a single application. Therefore, as for a recent IC card for a plurality of applications (e.g., a credit card, point accumulation, and a prepaid card), data can be read/written from/in the medium by only one portable terminal apparatus, instead of using conventional portable terminal apparatuses dedicated for the respective applications.
That is, the cardholder can call the application of, e.g., a prepaid card and confirm the outstanding balance of the prepaid card by selecting the application from the keyboard section of the portable terminal apparatus. Thereafter, the cardholder or user can call the application of a credit card by a selection operation from the keyboard section and confirm the credit card outstanding balance.
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 in the appended claims.
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 perspective view schematically showing the outer appearances of a portable terminal apparatus for an IC card and an IC card according to an embodiment of the present invention;
FIG. 2 is a block diagram schematically showing the arrangement of the portable terminal apparatus for an IC card;
FIG. 3 is a block diagram schematically showing the arrangement of the IC card;
FIGS. 4A and 4B are flow charts for explaining the read operation of data from the IC card; and
FIG. 5 is a table showing the contents of a key collation table for determining whether key collation is necessary.
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 schematically shows the outer appearances of a portable terminal apparatus for an IC card and an IC card according to this embodiment. More specifically, a portable terminal apparatus 1 for an IC card is formed into a card-like shape. One surface of the portable terminal apparatus 1 has a liquid crystal display section 2 serving as a display means for displaying various data, and a keyboard 3 serving as an input means for inputting password data and other data. One side surface of the portable terminal apparatus 1 for an IC card has a card slot portion 4 in which an IC card 10 is inserted and set.
The keyboard 3 includes an upward selection key 4a, a downward selection key 4b, an enter key (determination key) 5, an exit key 6 which is depressed when the current display is advanced to the next one, a power supply ON/OFF key 7, a ten-key pad 8, and the like. The selection keys 4a and 4b are keys for selecting one of a plurality of applications displayed on the liquid crystal display section 2, i.e., "credit card" 31, "point accumulation" 33, "prepaid" 35, and "other" 37 or for selecting data to be read by moving cursors 9a and 9b displayed on the liquid crystal display section 2.
The IC card 10 supports a plurality of applications such as a credit card, a point accumulation function, and a prepaid card, and a contact portion 6 (see FIG. 3) to be electrically connected to the interface section of the portable terminal apparatus 1 for an IC card is arranged at a predetermined portion on one surface.
FIG. 2 schematically shows the arrangement of the portable terminal apparatus 1 for an IC card. More specifically, a control unit 11 for performing overall control is mainly constituted by a CPU and the like. The control unit 11 is connected to a ROM (Read-Only Memory) 12 storing control programs and the like, a RAM (Read Access Memory) 13 serving as a storage means used as a work memory, a display drive circuit 14 for controlling and driving the display section 2, a voltage conversion circuit 15 for driving an IC card, and the keyboard 3.
The voltage conversion circuit 15 is connected to an IC card interface (I/F) section 16 serving as an interface means for exchanging a signal with the IC card 10 via the contact portion 6, and a battery 17 serving as a power supply section. In this embodiment, a battery having an output voltage of, e.g., 3 V is used as the battery 17.
The voltage conversion circuit 15 converts the power supply and signal voltages of the IC card I/F section 16 from a low voltage (+3 V) as the output voltage of the battery 17 into a specific voltage (+5 V) for an IC card.
FIG. 3 schematically shows the arrangement of the IC card 10. More specifically, the IC card 10 is constituted by the contact portion 6 and an IC chip 21. The IC chip 21 has a CPU 22 serving as a control element, a ROM 23 storing the control programs of the CPU 22, a RAM 24 serving as a work memory, an EEPROM 25 serving as a nonvolatile memory for storing data, and the like.
The EEPROM 25 stores data 57 for the credit card, data 59 for point accumulation, data 61 for the prepaid card, and the like. That is, the IC card is compatible with a plurality of applications and exhibits a plurality of functions by external instructions.
Next, the read operation of data from the IC card 10 in the above arrangement will be explained with reference to flow charts shown in FIGS. 4A and 4B. When data in the IC card 10 is to be read, the IC card 10 is inserted and set in the card slot portion 4. First, a plurality of applications 31, 33, 35, and 37 as shown in FIG. 1 are displayed on the selection window 2 (S11). A desired application is selected by the application selection keys 4a and 4b in the keyboard 3, the cursor 9a is moved to the application display 31, 33, 35, or 37 to be selected, and the determination key is depressed to determine the desired application (S13). Data of the selected application are read out from the EEPROM 25 of the IC card 10 to start this application (S15). Upon depression of the determination key, the control unit 11 performs an activation operation for the IC card 10 (S17) to wait for initial response data from the IC card 10.
If the initial response data from the IC card 10 are normally received, the control unit 11 refers to data in a key collation table shown in FIG. 5 to determine whether the selected application requires key collation (S19). The key collation table of FIG. 5 is stored in the ROM 12. Data representing whether each of a plurality of applications supported by the IC card 10 requires key collation are registered in the key collation table.
If key collation is required as a result of the above determination, the control unit 11 displays a prompt for of inputting a password on the display section 2. When password data (e.g., a password number) for key collation is input from the keyboard 3 (S21), and the control unit 11 determines that the password data is normally input (S23), the control unit 11 executes a key collation command for the IC card 10 on the basis of the input password data to perform key collation processing (collation of password data) in the IC card 10 (S25).
If an error occurs in this key collation processing (S27), the control unit 11 performs an inactivation operation for the IC card 10 (S39) to display a message representing a password error on the display section 2 (S41).
When the key collation processing is normally completed, or when key collation is unnecessary as a result of the above determination (S27), the control unit 11 performs selection processing of the application having selected for the IC card 10 (S29), and executes a data read command for the application (S31). With this processing, data of the selected application are read out from the EEPROM 25 of the IC card 10 and stored in the RAM 13.
When an error occurs in this read processing (S33), the control unit 11 executes an inactivation operation for the IC card 10 (S43). The control unit 11 displays a message representing a data read error on the display section 2 (S45).
On the other hand, when the readout processing is normally completed (S33), the control unit 11 executes an inactivation operation for the IC card 10 (S35). Thereafter, the control unit 11 displays on the display section 2 data which is read from the IC card 10 and stored in the RAM 13 (S37).
Note that when the selected application is "credit card", a plurality of credit card transaction results are read from the IC card 10 in the read processing and temporarily stored in the RAM 13, and a selection operation is performed (upward and downward keys are operated) with the keyboard 3. With this operation, data in the RAM 13 are sequentially read out and displayed on the display section 2.
When the selected application is "point accumulation", a service point based on the amount of purchase or the like is input from the keyboard 3 by the operation of a store clerk, and the input point is stored in the IC card 10. Further, when the selected application is "prepaid", the outstanding balance is read from the IC card 10 and temporarily stored in the RAM 13, and the data in the RAM 13 are read out and displayed on the display section 2.
In some cases, by performing a predetermined key operation with the keyboard 3, a calculation based on a specific algorithm is performed for data in the RAM 13 to display the calculation result on the display section 2.
As has been described above, according to the present invention, since the portable terminal apparatus for an IC card has a function of arbitrarily selecting a plurality of applications supported by the IC card, only one apparatus is compatible with a plurality of applications. Therefore, only one portable terminal apparatus for an IC card is compatible with respective applications which conventionally require dedicated apparatuses, resulting in an improvement in portability.
In addition, according to the present invention, the portable terminal apparatus can automatically determine whether key collation is necessary in reading data from an IC card. When key collation is necessary, data are read and displayed upon completion of key collation; and when key collation is unnecessary, data are immediately read and displayed.
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.
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A data processing apparatus for an IC card includes an interface section for receiving and accessing an integrated circuit medium, a first application function for performing data processing for the integrated circuit medium on the basis of the first application, a second application function for performing data processing on the basis of the second application, and a control unit for selecting one of the first and second application functions on the basis of an instruction from a keyboard and controlling it so as to perform data processing.
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FIELD OF INVENTION
[0001] This invention relates to device and method for handling metal sheets. More specifically it relates to a turning device and method for turning metal sheets used in connection with device separating metal deposit from a cathode.
BACKROUND OF THE INVENTION
[0002] The refining of many metals, such as copper, zinc and nickel, includes electrolytic process where harmful impurities are separated from the metal to be produced. The metal produced in the electrolytic process is gathered to the cathode by means of electric current. Usually the electrolytic process is carried out in tanks filled with an electrolyte containing sulphuric acid and, immersed therein, a number of plate like anodes and cathodes made of some electroconductive material and placed in an alternating fashion. At the top edges the anodes and cathodes are provided with lugs or bars for suspending them at the tank edges and for connecting them to the power circuit. The cathodes, i.e. the mother plates, used in the electrolytic process are made for of instance stainless steel, aluminium or titanium.
[0003] After the electrolytic process the anodes are removed from the tanks and the metal from the surface is removed for further processing. To the removing of the metal from the anode are used many various methods. For example the metal plate is opened slightly from one edge of the anode plate, grabbed with grip members and pulled apart from the anode. Other possibility is to cut the metal from the surface of the anode with cutting blades.
[0004] To maintain the production continuous there are developed devices for separating the metal deposit from the cathode. The devices are constructed roughly with two parts, the separating part and the turning part. In the separating part the metal is separated from the anode and in the turning part the separated metal parts are turned and moved further treatment in the process.
[0005] In documents U.S. Pat. No. 5,149,410 and WO 00/32846 are described such prior art devices. In U.S. Pat. no. 5,149,410 are described a method and apparatus for stripping electrodeposited metal sheets from permanent cathodes comprising a rotating carousel for receiving and sequentially advancing suspended permanent cathodes having electrodeposited metal sheets to a plurality of stations about the carousel including a loading station, a hammering station for loosening the upper edges of the metal sheets from the cathodes, an opening station for stripping of the metal sheets from the cathodes, a discharge station for discharge of pairs of metal sheets, and an unloading station for removal of stripped cathodes. The pairs of stripped metal sheets preferably are bottom discharged to a vertical envelope, which is rotated to a horizontal position for removal of metal sheets.
[0006] In document WO 00/32846 are described another device for separating metal deposit from a mother plate used as a cathode in an electrolytic process. In that device the metal sheets are separated and at the same time tilted from vertical position to horizontal position by gripping members guided with curved guides and then discharged from the device.
SUMMARY OF THE INVENTION
[0007] The object of the invention is to produce a device with fewer moving parts making it more reliable and compact. The device is also faster, which gives the opportunity to speed up the stripping process and more quiet than prior art devices. The same advantages are present also in related method for handling metal sheets.
[0008] Another object of the invention is to combine the separating device with the turning device to a compact design and more efficient method for handling metal sheets.
[0009] With one embodiment of the invention it is possible to alternatively unload the metal sheets to both sides of the stripping device. This is creating better and even more squared bundles, which are advantageous for further processing.
[0010] These above mentioned objects are achieved by a device and a method described later in the independent claims. In the dependent claims are presented other advantageous embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] In the following the preferred embodiments are described in more details with reference to the accompanying drawings, where
[0012] FIG. 1 is a simplified view of the first embodiment of the turning device,
[0013] FIG. 2 is another drawing of the first embodiment,
[0014] FIG. 3 is yet another drawing of the first embodiment,
[0015] FIG. 4 is a simplified view of the second embodiment of the turning device, and
[0016] FIG. 5 is a simplified view of the third embodiment of the turning device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] In FIG. 1 the plate shaped permanent cathode 1 is held in its position from the hanger bar 2 and the metal deposit 3 is surrounding the permanent cathode from both sides. The separation of the metal deposit 3 is done by two vertically moving knives 4 , which are waiting at the upper position. The knives 4 wedge the permanent cathode 1 free on both sides from the metal deposit 3 . For the separation of the metal deposit 3 can be used also any other known method.
[0018] The receiver unit 5 is waiting under the permanent cathode 1 for the metal deposit 3 to be separated. The receiver unit has a V-shaped construction for easy receiving of the metal deposit 3 but the design is not limited to this example and can be freely alternated. On both sides of the permanent cathode 1 are situated guiding means, which are for example rollers 6 . The receiver unit 5 under the permanent cathode 1 has a bottom 7 that can be opened.
[0019] In FIG. 2 the knives 4 have moved to the lower position and separated the metal deposit 3 from the permanent cathode 1 and the separated metal deposit is tilted against the support rollers 6 . Next the knives 4 are moving back to the upper position and the metal deposit 3 is moved by gravity to the waiting receiver unit 5 under the permanent cathode 1 .
[0020] In FIG. 3 the receiver unit 5 is acting as a turning device and tilted 90 degrees from vertical position to the lateral position around the turning axle 8 according to the arrow 9 and the bottom 7 of the receiving unit 5 is opened. The receiver unit 5 lays the metal deposit 3 to the conveyor 10 , which moves the metal deposit further in the process. At the same time another receiving unit 5 , which has solid bottom, is moved under the metal deposit 3 separation process and another permanent cathode 1 is switched to the separation device. This is due the fact that the two receiving units 5 are assembled at 90 degrees angle in relation to each other and the units are moved 90 degrees back and forth. Therefore always when another unit is unloading metal deposit 3 to the conveyer 10 the other is waiting next metal deposit from the separation. The construction of the turning device can naturally be made with just one receiving unit 5 but the process is then slower than with the device having two receiving units. Also the construction can have two conveyors 10 moving the metal deposits 3 into two opposite directions from the turning device and both receiving units 5 can then have solid bottoms. The turning of the receiver units 5 is done by any known mechanical construction. For example it can be driven by means of motor and gearbox or by a hydraulic cylinder.
[0021] By turning back and forth the turning device is unloading the metal deposits 3 to both sides of the separation device. This is advantageous for later bundling of the metal deposits 3 . The bundles are better and even more squared than when the metal deposits 3 are continuously unloaded to same direction. The turning device is constructed of one or more separate pieces at the transverse direction of the conveyor 10 and located on both sides of and/or in the middle of the unloading conveyor.
[0022] In FIG. 4 there are another embodiment of the turning device. The turning device has four receiving units 5 assembled around the turning axle 8 in 90-degree intervals. The turning device is rotating only in one direction and unloading the metal deposits 3 to one conveyer 10 . The next receiving unit 5 is automatically moving to the position for next metal deposit 3 when at same time the previous receiving unit is unloading metal deposit to the conveyer 10 . Here is presented only the embodiment with four receiving units 5 but it is possible to increase the number of receiving units to for example eight, twelve and so on. The only limiting thing for smooth operation between the turning devise and the separation device is that at the same time there is one empty receiving unit 5 waiting for next metal deposit 3 when another is unloading metal deposit to the conveyer 10 .
[0023] In FIG. 5 is presented an embodiment with lowering device 11 . In this embodiment the metal deposit 3 is lowered in a controlled way to the receiving unit 5 according the arrow 12 . The lowered position is described with dashed line. Lowering the metal deposit 3 to the receiving unit 5 is reducing the noise of the device. After that the receiving unit 5 is working as a turning device and passes the metal deposit 3 to the conveyer 10 . At the same time when the receiving unit 5 is turning towards the conveyer 10 the lowering device 11 is raised back to the upper position for receiving the next metal deposit 3 to be lowered to the next receiving unit 5 .
[0024] The above described devise and method are suitable for all different kinds of cathodes used in electrolytic processes. By above described way the turning device is combined with the separation device and more compact design is achieved. This reduces the amount of movable parts compared to the prior art devices. It also makes possible to speed up the separating unit.
[0025] While the invention has been described with reference to its preferred embodiments, it is to be understood that modifications and variations will occur to those skilled in the art. Such modifications and variations are intended to fall within the scope of the appended claims.
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The invention relates to a turning device for metal deposits used in combination with a separating device, comprising at least one turnable receiving unit mounted on a rotating axle under the separating device and in the vicinity of at least one conveyor, guiding means for guiding a metal deposit to a receiving unit acting as a turning device and means for rotating the receiving unit. The invention also relates to a method for handling metal deposits.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of and priority from U.S. Provisional Patent Application Ser. No. 61/762,594, filed Feb. 8, 2013, which is incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to safety systems for power equipment. More specifically, this specification relates to safety systems which include motion sensors and software analysis tools, such as the Leap Motion controller, to detect hazardous conditions occurring during the use of power tools such as table saws, sliding table saws, joiners, up-cut saws and other machinery typically found in woodworking shops.
BACKGROUND
[0003] Safety systems may be employed with power equipment to minimize the risk of injury when using the equipment. Some safety systems include an electronic system to is detect the occurrence of a dangerous condition and a reaction system to minimize any possible injury from the dangerous condition. For instance, some safety systems attempt to detect when a human body contacts or comes into dangerous proximity to a predetermined portion of a machine, such as detecting when a user's hand touches the moving blade of a saw. As another example, the safety system may be configured to detect the rapid movement of a workpiece due to kickback by a cutting tool. When a dangerous condition is detected, the safety system reacts to minimize injury. Motion detectors can be used in safety systems but generally they are limited in their ability to distinguish what objects are in motion and to track their motion accurately.
[0004] A controller made by a company called Leap Motion purportedly provides an area of 3D interaction space of roughly eight cubic feet in which human body parts and gestures as well as other objects and their movement may be identified and monitored with an alleged accuracy of tracking individual finger movements to 1/100th of a millimeter. With this technology it may be possible to identify the type of object that is moving, ie. whether a human hand or a specific tool, and to track the movement anywhere in the 3D interaction space with a speed and accuracy that allows for the identification of a hazardous condition and a fast response of the safety system to prevent or greatly minimize injury. While the Leap Motion controller uses optical sensors, there are other technologies that may be used as well, such as a motion sensor from the company Elliptic Labs that detects hand motion and gestures using ultrasonic sensors.
[0005] The present invention relates to the incorporation into power equipment of safety systems that include motion detectors, such as a Leap Motion controller or an Elliptic is Labs controller, adapted to detect a dangerous situation such as when a portion of a person's body comes in close proximity to the blade or other cutting tool to protect the user against serious injury if a dangerous, or triggering, condition, such as contact between the user's body and the blade or other cutting tool, occurs. Data from the motion detector is used to trigger a reaction mechanism that quickly takes some action to minimize injury.
BRIEF DESCRIPTION OF DRAWINGS
[0006] FIG. 1 shows a table saw.
[0007] FIG. 2 is a schematic block diagram of a machine with a fast-acting safety system.
[0008] FIG. 3 is a schematic diagram of an exemplary safety system in the context of a machine having a circular blade.
DETAILED DESCRIPTION
[0009] A table saw 2 is shown in FIG. 1 . Saw 2 includes a table 4 and a circular blade 6 that extends up through the table. A piece of wood, or other material to be cut, is placed on the table and pushed into contact with the spinning blade to make a cut. The saw in FIG. 1 is one example of a cutting machine typically used in a wood-working shop. Other cutting machines may include joiners, sliding table saws, up-cut saws, band saws etc. In all these cases, cuts are made to a workpiece by a rapidly moving cutting tool, such as a blade or cutter head, that may be of a considerable size or weight. The cutting tool poses a serious risk of injury to the user of the machinery if the user were to accidently contact the cutting tool while in operation.
[0010] FIG. 2 shows a block diagram of a cutting machine 10 that incorporates a safety system. Machine 10 may be any of a variety of different machines, such as table saws, miter saws, band saws, jointers, shapers, routers, hand-held circular saws, up-cut saws, sanders, etc. Machine 10 includes an operative structure 12 having a working or cutting tool 14 and a motor assembly 16 adapted to drive the cutting tool. The particular form of cutting tool 14 will vary depending upon the various embodiments of machine 10 . For example, cutting tool 14 may be a single, circular rotating blade having a plurality of teeth disposed along the perimetrical edge of the blade, such as in the saw of FIG. 1 . Alternatively, the cutting tool may be a plurality of circular blades, such as a dado blade or dado stack, or some other type of blade, cutter head or working tool.
[0011] Machine 10 includes a safety system 18 configured to minimize the potential of a serious injury to a person using the machine. Safety system 18 is adapted to detect the occurrence of one or more dangerous conditions during use of the machine. If such a dangerous condition is detected, safety system 18 is adapted to engage operative structure 12 to limit any injury to the user caused by the dangerous condition. Exemplary safety systems are disclosed in International Publication Number WO 01/26064 A2, published Apr. 12, 2001, the disclosure of which is hereby incorporated by reference.
[0012] Machine 10 also includes a suitable power source 20 to provide power to operative structure 12 and safety system 18 . Power source 20 may be an external power source such as line current, or an internal power source such as a battery. Alternatively, power source 20 may include a combination of both external and internal power sources. Furthermore, power source 20 may include two or more separate power sources, each adapted to power different portions of machine 10 .
[0013] Safety system 18 includes a detection subsystem 22 , a reaction or danger mitigation subsystem 24 and a control subsystem 26 . Control subsystem 26 may be adapted to receive inputs from a variety of sources including detection subsystem 22 and is configured to control machine 10 in response to the inputs it receives. Detection subsystem 22 is configured to detect one or more dangerous or triggering conditions during use of machine 10 such as when a portion of the user's body is dangerously close to or in contact with a portion of cutting tool 14 or when there is rapid movement of a workpiece due to kickback by the cutting tool. In some embodiments, detection subsystem 22 may inform control subsystem 26 of the dangerous condition, which then activates reaction subsystem 24 . In other embodiments, the detection subsystem may be adapted to activate the reaction subsystem directly. Once activated in response to a dangerous condition, reaction subsystem 24 is configured to engage or act on operative structure 12 quickly to prevent serious injury to the user. Examples of detection subsystems, reaction subsystems and control subsystems are disclosed in International Publication Number WO 01/26064 A2, published Apr. 12, 2001, which is incorporated by reference.
[0014] The system shown in FIG. 2 and described above may be implemented in a variety of ways depending on the type and configuration of operative structure 12 . FIG. 3 shows one example of the many possible implementations of safety system 18 . System 18 is configured to engage an operative structure having a circular blade 40 mounted on a rotating shaft or arbor 42 . For example, a brake pawl can engage and stop the blade from spinning upon detection of a dangerous condition. Additionally or alternatively, the arbor can be supported by an arbor support that is free to pivot under a strong enough torque so that the blade can retract downward upon detection of a dangerous condition. For example, the reaction subsystem 24 can be adapted to engage the blade to stop the blade which, by the conservation of angular momentum, draws the arbor support that supports the arbor down to retract the blade.
[0015] Detection subsystem 22 is implemented by a motion detector, or hand tracking system, such as a Leap Motion controller, which is a USB peripheral device consisting of a sensor 30 that may be mounted above, below or to the side of the blade and workspace area to monitor the user work area around the blade, and a processing unit 32 to run software, such as Leap Motion enabled software. One Leap Motion controller can purportedly monitor up to roughly eight cubic feet of three-dimensional space, and several Leap Motion controllers can be hooked up together to cover an even larger space. The Leap Motion sensor senses objects optically within the three-dimensional interaction space using infrared LEDs and cameras. Accordingly, in this embodiment, sensor 30 may be one or more infrared cameras, and sensor 30 may also include one or more infrared LEDs. The processing functionality of the Leap Motion controller is determined by the software that is loaded into the controller. The Leap Motion enabled software together with the high-performance Leap Motion sensor purportedly provide a powerful detection system capable of recognizing and distinguishing the human hand from other objects typically used while operating the saw. This allows the detector to identify various safety hazards including but not limited to situations where a human body contacts or comes dangerous close to the moving blade of a saw or when a workpiece moves suddenly and rapidly back toward the operator of the saw due to kickback. This information may then be used to trigger or signal the reaction mechanism which than acts to minimize or prevent injury.
[0016] Other motion sensors could also be used, such as the Elliptic Labs motion sensor which uses ultrasonic sensors. In this embodiment, sensor 30 shown in FIG. 30 would be one or more ultrasonic sensors and/or one or more ultrasonic emitters. The Elliptic Labs motion sensor technology is described in the following patent application publications, the disclosures of which are all herein incorporated by reference: US 2012/0313900 published Dec. 13, 2012, US 2012/0299820 published Nov. 29, 2012, US 2012/0274610 published Nov. 1, 2012, US 1012/0243374 published Sep. 27, 2012, US 2012/0206339 published Aug. 16, 2012, US 2012/0099403 published Apr. 26, 2012, US 201110254762 published Oct. 20, 2011, US 2011/0148798 published Jun. 23, 2011, US 2011/0103448 published May 5, 2011, US 2011/0096954 published Apr. 28, 2011, and US 2010/0296368 published Nov. 25, 2010.
[0017] Variations of the above-described embodiments are possible within the scope of this disclosure.
INDUSTRIAL APPLICABILITY
[0018] The safety systems disclosed herein are applicable to woodworking power tool to equipment, and particularly to table saws.
[0019] It is believed that the disclosure set forth above encompasses multiple distinct inventions with independent utility. While each of these inventions has been disclosed in its preferred form, the specific embodiments thereof as disclosed and illustrated herein are not to be considered in a limiting sense as numerous variations are possible. The subject matter of the inventions includes all novel and non-obvious combinations and sub-combinations of the various elements, features, functions and/or properties disclosed herein. No single feature, function, element or property of the disclosed embodiments is essential to all of the disclosed inventions. Similarly, the recitation of “a” or “a first” element, or the equivalent thereof, should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements.
[0020] It is believed that the following claims particularly point out certain combinations and sub-combinations that are directed to disclosed inventions. Inventions embodied in other combinations and sub-combinations of features, functions, elements and/or properties may be claimed through amendment of the present claims or presentation of new claims in this or a related application. Such amended or new claims, whether they are directed to a different invention or directed to the same invention, whether different, broader, narrower or equal in scope to the original claims, are also regarded as included within the subject matter of the inventions of the present disclosure.
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Woodworking machines including a blade to cut a workpiece and a detector to detect movement or position of at least part of a human body near the blade and a reaction system adapted to mitigate possible injury upon detection of a dangerous condition between the human and the blade.
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