description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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RELATED APPLICATIONS
This application is a continuation-in-part application of U.S. Ser. No. 667,762 filed on Nov. 2, 1984.
BACKGROUND OF THE DISCLOSURE
Conventional methods for servicing safety relief valves typically require awkward and expensive piping fabrications or even total shutdown of the system for routine or emergency service of redundant safety relief valves. Some conventional methods require two separate penetrations into the pressure vessel connected with mechanically linked block valves. Other conventional methods incorporate three-way block valves connected to a single penetration into the pressure vessel. The three-way block valve configuration commonly results in high pressure losses. The valve selector manifold of the present disclosure overcomes the disadvantages associated with these conventional methods.
This apparatus is directed to a valve mounting manifold. It is adapted to be attached to a pressure vessel for protection of the vessel against overpressure. It is duplicate valved to enable relief devices to be installed with only a single opening into the pressure vessel thereby reducing the number of openings formed in the pressure vessel. It is axiomatic that openings cut into a pressure vessel, cause problems by increasing complexity, all at an increased cost. This device enables the number of openings cut into a pressure vessel to be reduced. It defines a pressure vessel selector manifold enabling multiple safety relief valves to be installed at a single vessel opening. The valve selector manifold of this disclosure enables one safety valve to be placed in service while a second valve is out of service or even dismounted for maintenance.
The dual active valve selector manifold of this disclosure provides dual connections for relief during flowing conditions. This manifold has smoothly faired flow paths to the selected relief valves and thereby enables the relief valves to be exposed to the pressure of the vessel with minimum pressure loss during flowing conditions.
Pressure vessels typically require one or more safety relief valves for protection of the vessel in the event of overpressure. The selector valve manifold of this disclosure is particularly suitable for use with pressure vessels requiring two safety relief valves in operation to meet the safety standards established for the pressure vessel. The selector manifold of this disclosure is dual active, permitting both safety relief valves to be exposed to the pressure of the pressure vessel simultaneously through a single opening into the pressure vessel.
Periodic maintenance or repairs of the safety relief valves will be required. The valve selector manifold of this disclosure enables field servicing of one relief valve without defeating safety valve protection of the pressure vessel by the second relief valve. For instance, this device mounts duplicate safety relief valves, enabling one to be switched out of service while the other remains operative. Removal of one can be undertaken while the other is operative. This can be accomplished without reducing pressure in the pressure vessel.
SUMMARY OF THE INVENTION
With the foregoing in view, the present apparatus is described in summary fashion as incorporating a flange connector adapted to be joined to a pressure vessel at a flanged opening. The flange encloses a passage of specific diameter. The housing encloses alternative flow paths. The alternate flow paths are selected by rotating a rotor mounted on a central pin for rotation, creating alternate flow paths through the selector valve manifold. The flow paths are routed to a top plate, the top plate having spaced openings to enable similar or identical safety relief valves to be mounted on top of the selector valve manifold. A closure disc mounted on the rotor enables alternate closing of the flow passages permitting maintenance and repair of the relief valves mounted to the selector valve manifold. When maintenance or other service is not required, the rotor is positioned so that both flow passages to the safety relief valves are open.
Many other details will be observed upon review of the description below of the preferred and illustrated embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, a more particular description of the invention briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of the invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 is a sectional view through the selector valve manifold of the invention showing details of constructions;
FIG. 2 is a top view of the rotor member of the invention;
FIG. 3 is a sectional view through the selector valve manifold showing that the both flow paths are open through the manifold;
FIG. 4 is a sectional view taken along line 2--2 of FIG. 1; and
FIG. 5 is a sectional view of the closure disc for selectively closing the flow paths of the selector manifold.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 of the drawings, the numeral 10 identifies the complete assembly which comprises the selector manifold apparatus of this disclosure. The apparatus 10 includes a circular flange body component 12 which will be described as the lower body portion. It terminates at a transverse flat face 14; the flat face 14 being adapted to abut a matching face of an upstanding and encircling upper body component 16. As will be observed, they are joined together by suitable headless bolts 18, and a suitable inlet opening is defined at 20. The inlet opening 20 is adapted to be connected by any suitable means, including a matching flange whereby connection is made to a pressure vessel or the like.
Centrally located within the two housing components 12 and 16 is a rotatable component. It is captured within the two housing components and is enclosed in a pressure type chamber 22. More accurately, it is enclosed in the two housing components when assembled so that it operates to divert the flow therethrough along a route to one or both of the safety relief valves. The rotatable component, which for purposes of convenience, will be described as a rotor, is generally identified by the numeral 24, shown in FIG. 2. The rotor 24 is preferably formed as casting and incorporates three curving conduits 26, 28 and 30 therein. The conduits 26, 28 and 30 terminate or merge at the common inlet end 32 of the rotor 24. The inlet end 32 is telescoped adjacent the inlet opening 20 of the lower housing component 12. The inlet 32 has an internal diameter sized to be equal to or larger than the mating outlet in the pressure vessel opening. Moreover, the inlet 32 has an internal diameter which is larger than the internal diameter at the outlet end of the curving conduits 26, 28 and 30 and sized so that there is minimum constriction to fluid flow, thereby obtaining minimum pressure drop between the inlet and outlets of the apparatus 10.
Referring now to FIG. 1, the curved conduit 28 is shown terminating at an outlet end 29. The end 29 is spaced from a circular, axially hollow seat assembly 35. The seat assembly 35 is spaced from the end 29 of the curved conduit 28. The seat assembly 35 has a downwardly directed face 33 for sealing purposes. A fluid tight seal between the seat assembly 35 and the upper housing component 16 is provided by a seal ring 37.
The upper housing 16 includes a curved passage 17. The passage 17 extends upwardly as shown in FIG. 1 where it exposes an open upper end and is conveniently welded to a flanged fitting 36 for connection with a pressure relief valve. The passage 17 may capture fluid under pressure between the relief valve connected at the flanged fitting 36 and the valve seat assembly 35. To this end, the numeral 38 identifies a hand valve which opens into the passage 17. The hand valve 38, when opened, permits trapped pressure in the passage 17 to be released. In addition, the hand valve 38 provides an inlet to the passage 17 testing the relief valve connected at the flanged fitting 36.
As described at this juncture, it will be understood that duplicate equipment is arranged on both the right and left as shown in FIG. 1. That is, there is a similar left seat assembly 35 cooperative with a similar left side passage 17 for convenient connection to a similar safety relief valve. Moreover, the left hand passage is protected by a suitable hand valve 38 permitting access to that passage. Likewise, the curving conduits 26, 28 and 30 are substantially identical curving upwardly and outwardly from the common inlet 32. The curved conduits 26 and 30 terminating at outlet ends 27 and 31, respectively.
The conduits 26, 28 and 30 and the passages 17 form a smooth, gently curving flow passage for directing fluid flow from the pressure vessel outlet to the pressure relief valves connected at the flanged fittings 36. Obstructions or abrupt changes in flow direction are avoided. The curving flow passages permits a smooth change in direction of fluid flow through the apparatus 10 with minimum pressure drop between the inlet and outlets of the apparatus 10.
The rotor 24 is preferably formed as casting, incorporating the curved conduits 26, 28 and 30, and the inlet 32 therein. The rotor 24 also includes an upstanding circular sleeve 39 extending from the upper domed end of the rotor 24. The sleeve 39 defines a blind hole sized to receive the lower end of a rotatable pin 42. A hole through the sleeve 39 enables a bolt 40 to be anchored through the sleeve 39 and to the lower end of the rotatable pin 42. The pin 42 supports a downwardly protruding lug 34 which is perforated to align with the hole in the sleeve 39 for receiving the bolt 40 therethrough. The bolt 40 fastens at a specified elevation to support in a hanging or downwardly depending position the rotor 24. The rotor 24 has a center line axis of rotation defined by the mounting pin 42 and it is axially coincident with the inlet opening at 20 and the inlet 32 of the rotor 24. Accordingly, the rotor 24 rotates to position the curved conduits 26, 28 and 30 in alignment with the passages 17 shown in FIGS. 1 and 3. The curved conduits rotate about the axis defined by the pin 42 so that each curved conduit can be aligned with the left or right passages in the upper housing 16 as desired. A separate construction supports a closure member on the rotor 24. The passages 17 in the upper housing 16 are aligned at approximately 180° on opposite sides from the pin 42. The closure member and the curved conduits 26, 28 and 30 are aligned at 90° spacing about the rotational axis of the rotor 24.
This kind of arrangement utilizes the rotor 24 to rotate the curved conduits 26, 28 and 30 to a desired alignment as illustrated in FIGS. 1 and 3. Curved conduits 26 and 30 are aligned at 180° spacing permitting fluid flow through both passages 17 upon rotation of the rotor 24 in the position illustrated in FIG. 3. The curved conduit 28 is aligned 180° from the closure disc 44. The closure disc 44 is mounted on a telescoping mounting pin 46. A mounting plug 45 is threaded to the rotor 24, as best shown in FIG. 5, for mounting the closure disc 44 to the rotor 24. The pin 46 extends through the mounting plug 45 and is threaded to the closure disc 44. The pin 46 is axially hollow at 47. It is hollow from the exposed end back to the recessed end as shown in FIG. 5. A lateral passage 48 aids in permitting fluid to flow through the pin 46. The pin 46 is permitted to move relative to the mounting plug 45 so that the closure disc 44 wobbles slightly when not sealed against the face 33 of the seat assembly 35. This permits the closure disc 44 to accommodate for slight misalignment with the seat assembly 35. Upon slight downward movement of the rotor 24, a gap is formed at 49 establishing fluid communication between the interior chamber 22 and the passage 17. The flow path is through the gap at 49 past seal ring 50. The flow path in the vicinity of the pin 46 is directed along the pin 46 through passage 47 and out into the passages 17.
The closure disc 44 incorporates a peripheral seal 52. The seal 52 is included to seal against the face 33 of the seat assembly 35. Assuming a pressure differential acting on the closure disc 44, it seals at the face 33 with the seal ring 52, and flow is prevented through the blocked axial passages 17 when the rotor 24 is in the up position illustrated in FIG. 1. When the rotor 24 moves downwardly, the seal system is broken whereby flow can occur through the gap 49.
As will be understood, the closure disc 44 can be raised or lowered. It is shown in the sealing and raised position in FIGS. 1 and 5. Lowering the rotor 24 breaks the seal at 49 thereby permitting the pressure in the chamber 22 to be transmitted to the opposite side of the closure disc 44 via the passage 47 in pin 46. Thus, the pressure is equalized across the closure disc 44 breaking the seal with the face 33 of the seat assembly 35; thereby freeing the closure disc 44 for easy disengagement and rotation. When disengaged, the disc 44 may be rotated 180° over to the other passage 17 so that the safety relief valve connected thereto may be serviced, if required. If additional service or repair is not required, the closure disc 44 is rotated 90° for aligning the curved conduits 26 and 30 with the passages 17 for normal operation of both safety relief valves. As will be understood, the rotor 24 can be rotated with no flow or during full flow, thereby interrupting full flow to only one of the safety relief valves at a time so that a safety relief valve is operationally connected to the pressure vessel at all time.
Referring again to FIG. 1 the mounting pin 42 will be described in greater detail. First of all, a seal about the mounting pin 42 is defined at 54. A stack of seal members is compressed by capture ring 56. The capture ring 56 is jammed downwardly by a flanged jam member 58. The jam member 58 is pulled downwardly by suitable bolts 59 which thread into the upper housing 16. A portion of the pin 42 extends above the upper housing 16 and is readily accessible.
The mounting pin 42 extends upwardly through a sleeve 60. The sleeve 60 is fixedly anchored by an inverted U-shaped mounting bracket or the like connected by suitable nuts and bolts to the upper housing 16. This clamps the sleeve 60 in location. That is, the sleeve 60 is fixed at an elevation which is specified by the U-shaped mounting clamp on it and is not able to move. In this fixed elevation, the sleeve 60 supports an external threaded sleeve 62. The sleeves 60 and 62 are threaded together as shown in FIG. 1. The sleeve 62 in turn supports an external sleeve 64 joined thereto by a set screw 65. The set screw 65 is included to lock the sleeves 62 and 64 together.
The mounting pin 42 includes a circumferential groove 66 adjacent its upper end for receiving suitable ball bearings 67 therein. The ball bearings 67 are engaged by a lock nut 68 thereabove. The sleeves 62 and 64 and the lock nut 68 form a rotatable assembly 69 which may be grasped and rotated. Rotation is accomplished at the threaded interconnection 63 between the sleeves 60 and 62. The rotatable lock assembly 69 may be rotated clockwise or counter clockwise, thereby driving the rotating components shown around the pin 42 imparting such threaded rotation through the ball bearings 67. Rotation of the rotatable assembly 69 accomplishes raising and lowering of the mounting pin 42. The mounting pin 42 serves as an axis of rotation. The pin 42 is able to travel downward slightly, it being observed that the rotor 24 terminates in a telescoping connecting between the inlet 32 of the rotor 24 and the inlet 20 of the lower body 12. Downward movement of the mounting pin 42 forces the rotor 24 downwardly, thereby breaking the seal at 49 and permitting equalizing pressure across the closure disc 44 in the manner described above. Axial displacement of the mounting pin 42 also assures clearance between the rotor 24 and the body 16 during rotation of the rotor 24.
Rotation of the assembly 69 at the top of the mounting pin 42 accomplishes an unlocking function. The numeral 70 identifies a locking lug which protrudes radially inwardly from the surrounding lower body component 12. The rotor 24 supports a collar 71 which extends partially around the lower end thereof. The collar 71 has a top face or surface 72. When the rotor 24 is forced downwardly, the top surface 72 is located below the lug 70 whereby relative rotation is permitted. The collar 71 is slotted at 74, thereby permitting the lug 70 to move relatively upwardly and downwardly in the slot 74 to assure proper alignment of the curved conduits 26 and 30, as shown in FIG. 3. A pair of stop lugs 76 are located on the rotor 24. The stop lugs 76 extend above the surface 72 of the collar 71 providing an abutment surface for limiting rotational movement of the rotor 24. A stop lug is located adjacent each end of the collar 71 and spaced therefrom defining a slot 78, thereby permitting the lug 70 to move relatively upwardly and downwardly in the slot 78. In this manner, rotational movement of the rotor 24 is limited to about 180° in either direction to bring the lug 70 into either extremity of its permitted movement. The slots 74 and 78 are positioned to assure that proper alignment of the rotor 24 relative to the passages 17 is accomplished.
The arrangement just described accomplishes vertical translation of the rotor 24, all accomplished without leakage along the pin 42, for the purpose of breaking or making the seal at the closure disc 44 and to assure clearance of the rotor 24 with the body 16 during subsequent rotation.
Operation of the apparatus 10 is accomplished by first rotating the lock assembly 69 for imparting axial movement to the mounting pin 42. Recall that the sleeve 60 is fixed in elevation so that relative rotation of the lock assembly 69 forces the mounting pin 42 downwardly or upwardly depending on the direction of rotation. Once the mounting pin 42 and thereby the rotor 24 has been moved downwardly, the lug 70 is then located above the collar 71 and is able to slide along the top surface 72 thereof. Moreover, the gap 49 is opened, permitting pressure equalization across the closure disc 44. The rotor 24 is then rotated to the desired position aligning the curved conduits 26, 28 and 30 relative to the passages 17 for communicating fluid pressure to the safety relief valves.
Alignment of the curved conduits also align the lug 70 with one of the slots 74 and 78 of the collar 71. The lock assembly 69 is again rotated to pull the rotor 24 upwardly and thereby position the lug 70 in the aligned slot 74 or 78. This locks the rotor 24 in position and prevents relative rotation of the rotor 24 within the housing chamber 22. If the rotor 24 is rotated to close one of the passages 17 as shown in FIG. 1, upward movement of the rotor 24 closes the gap at 49 and forces the closure disc 44 against the face 33 of the seat assembly 35.
The chamber 22 is pressurized by fluid pressure entering the chamber 22 through the curved conduits 26 and 30 when the rotor 24 is rotated to the position shown in FIG. 1. Pressurization of the chamber 22 forces the closure disc 44 against the seal assembly 35 and thereby perfecting a fluid tight seal at seal ring 52.
Referring now to FIG. 3, the rotor 24 is positioned so that both passages 17 are open. The safety relief valves mounted to the apparatus 10 are thus both exposed to fluid pressure of the pressure vessel for protection of the vessel in the event of overpressure. This is the normal operational position of the dual active selector valve manifold of the present disclosure.
The apparatus 10 has been described herein for use in conjunction with safety relief valves. This disclosure, however, is not limited to use solely with safety relief valves. Operation of the apparatus 10 can be performed with full fluid flow through both of the passages 17. Therefore, use of the apparatus 10 in a diverter-type application for fluid flow. Use of the apparatus 10 as a diverter valve or the like for directing fluid flow is contemplated herein and is within the scope of this disclosure.
While the foregoing is directed to the preferred embodiment of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims which follow. | A dual active selector valve is set forth. In the preferred and illustrated embodiment, a flange supporting a manifold body is attached to a pressure vessel. The passage through the flange has a selected diameter and the manifold body opens out to a larger diameter, sufficient to enable two valves to be connected side by side, having inlet passages equal in diameter to about one half the selected diameter. A rotatable conduit member is mounted within the manifold body having a centrally located pin for rotation, the rotatable portion incorporating separate flow passages selectively connecting to one of the two alternately deployed valves, and also supporting a valve closure plate to plug the passageway into the valve not being used. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates generally to a hydraulic shock absorber applicable to the suspension of a vehicle, such as an automotive vehicle. More specifically, the invention relates to a shock absorber having a relief mechanism for relieving excessive hydraulic pressure which may adversely affect the riding comfort of the vehicle.
Vortex flow shock absorbers of various constructions are well known. Such shock absorbers are particularly useful in suspensions for compact size vehicles. In conventional vortex flow shock absorbers it is necessary to provide a relief mechanism for relieving excessive hydraulic pressure and, in turn, for preventing the shock absorber from producing too great a shock absorbing force for comfort. To accomplish this requirement, there have been developed various pressure relief mechanisms for vortex flow shock absorbers.
However, the prior art pressure relief mechanisms have complicated constructions resulting in difficulty in assembling.
SUMMARY OF THE INVENTION
Therefore, it is a principle object of the present invention to provide a vortex flow shock absorber with a relief mechanism of simple construction, which will allow easy assembling of the shock absorber.
Another and more specific object of the invention is to provide a vortex flow shock absorber which incorporates a one-way valve as the pressure relief mechanism, the valve being provided in a piston rod in order to easily attach a piston onto the piston rod.
To accomplish the above-mentioned and other objects, there is provided a vortex flow shock absorber which includes a piston having a vortex chamber therein. The piston communicates with a first fluid chamber of the shock absorber cylinder via a vortex chamber and with a second fluid chamber, separated from the first by the piston, via a flow restricting opening. A one-way valve is provided in a piston rod which defines a fluid passage permitting one way flow of fluid from the vortex chamber to one of the fluid chambers. The one-way valve is responsive to excessive fluid pressure in the vortex chamber to relieve the fluid pressure.
According to the present invention, the piston and piston rod can be attached together with pressure welding. This simplifies the assembling operation of the piston onto the piston rod.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more fully understood from the detailed description given hereinbelow and from the accompanying drawings of preferred embodiments of the present invention which, however, should not be taken as limiting the present invention but for elucidation and explanation only.
In the drawings:
FIG. 1 is a longitudinal section of a preferred embodiment of a vortex flow shock absorber according to the present invention;
FIG. 2 is an enlarged section of a piston of the shock absorber of FIG. 1;
FIG. 3 is a transverse section of the piston taken along line III--III of FIG. 2; and
FIG. 4 is a similar view to FIG. 2 and showing another embodiment of the piston of the shock absorber.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, there is illustrated the preferred embodiment of a directacting shock absorber according to the present invention. The shock absorber includes outer and inner cylinders 30 and 32 coaxially arranged with respect to each other. The outer cylinder 30 is closed; the upper and lower ends with elastic sealers 34 and 40 and an end fitting 36 respectively. The inner cylinder 32 is disposed within the outer cylinder 30 in spaced relationship to define therebetween a fluid reservoir chamber 38. A bottom fitting 200 is attached at the lower end of the inner cylinder 32. The upper end of the inner cylinder 32 is closed with an elastic sealer 40 to define a fluid chamber 42 in the inner cylinder which is filled with a working fluid. The sealer 40 has a recess 44 on the upper surface thereof which receives a downwardly projecting portion at the lower surface of the sealer 34. Also, the sealer 34 secures a sealing ring 46 against an inner surface of the upper end of the outer cylinder 30.
Piston 100 is movably disposed within the fluid chamber 42. The piston 100 is connected to the lower end of a piston rod 101 with pressure welding. The piston 100 divides the fluid chamber 42 into upper and lower fluid chambers 48 and 50. As shown in FIGS. 2 and 4, the piston 100 is formed with a circular groove 102 therein.
The piston 100 is formed with vertically extending openings 106 adjacent the circumference thereof and has a vertically extending opening 108 through the axial center of an upper horizontal section thereof.
To the lower end of the piston, a fitting 124 with a central opening 126 is secured to define a vortex chamber 128 within the groove 102. The vortex chamber 128 communicates with the upper fluid chamber 48 via vortex passages 120 and the openings 106. In turn, the vortex chamber 128 communicates with the lower fluid chamber 50 via the opening 126.
The vortex chamber 128 further communicates with the upper fluid chamber 48 via the opening 108. The upper end of the opening 108 is closed by a ball-shaped closure 130 which is disposed within a groove 132 formed on the lower end of the piston rod 101. The closure 130 is adapted to be movable within the groove 132 along the piston rod axis and is urged toward the upper end of openings 108 by a helical coil spring 133 which is also disposed within the groove 132. The groove 132 communicates with the upper chamber 48 via a lateral passage 134 which extends laterally through the piston rod 101. The closure 130, the coil spring 133 in the groove 132 constitute a one-way valve 136, restricting fluid flow from the upper fluid chamber 48 to the vortex chamber 128.
During a compression stroke, the piston 100 moves downwardly to expand the volume of the upper fluid chamber 48, thus reducing the fluid pressure therein and to compress the volume of the lower fluid chamber 50, thus increasing the fluid pressure therein. Due to the fluid pressure difference between the upper and lower fluid chambers 48 and 50, fluid flow is produced from the lower fluid chamber 50 to the upper fluid chamber 48. Fluid flows into the vortex chamber 128 via the opening 126 in the fitting 124. The fluid in the vortex chamber 128 flows through the vortex passages 120, and the openings 106 to the upper fluid chamber 48. At the same time, the closure 130 is forced upwardly against a set pressure from the coil spring 132 to open the upper end of the openings 108 to permit fluid in the vortex chamber 128 therethrough.
On the other hand, due to an increase in the fluid pressure in the lower fluid chamber 50, fluid flows into the fluid reservoir 38 via the bottom fitting 200. By increasing the fluid amount in the fluid reservoir chamber 38, gas in an upper section 39 of the fluid reservoir chamber is compressed resulting in an increase in the pressure thereof.
During an expansion stroke, the piston 100 moves upwardly to expand the volume of the lower fluid chamber 50 thereby reducing the fluid pressure therein and to reduce the volume of the upper fluid chamber 48 thereby increasing the fluid pressure therein. Due to the fluid pressure difference between the upper and lower fluid chambers 48 and 50, fluid flow is produced from the upper fluid chamber 48 to the lower fluid chamber 50. Fluid flows into the vortex chamber 128 in vortex fashion via the vortex passages 120 in order to produce an absorbing force against the shock. Fluid in the vortex chamber 128 then flows through the opening 126 to the lower fluid chamber 50.
On the other hand, due to a reducing of the fluid pressure in the lower chamber 50, fluid in the fluid reservoir chamber 38 flows into lower chamber 50 via the bottom fitting 200.
During the fluid flow as set forth, the vortex passages 120 and opening 126 serve as flow limiting orifices to produce a resistance to fluid flow. On the other hand, the vortex produced in the vortex chamber 128 also results in a resistance against fluid flowing through the vortex chamber. If the piston stroke is so small or the piston speed is so low that it cannot generate sufficient resistance against the fluid flowing through the vortex chamber 128, the resistance provided by the orifice effect of the vortex passages 120 and the opening 126 works as the main factor for producing an absorbing force against a shock applied to the shock absorber. When the piston stroke becomes large enough or the piston speed is sufficiently increased, the vortex in the vortex chamber 128 provides a sufficient resistance against the fluid flowing through the vortex chamber.
Here, since the fluid pressure in the vortex chamber 128 of the piston 100 is substantially the same as that in the lower fluid chamber, if the fluid pressure in the lower chamber becomes greater than that of the set pressure of the closure 130, the closure 130 is moved upwardly to allow fluid to flow therethrough. Thus, the closure 130 with the coil spring 133, the groove 132, the lateral passage 134 and the opening 108 serves as a relief valve for preventing the shock absorber from producing excessive absorbing force.
The absorbing force produced in the vortex chamber by the vortex is proportional to the diameter of the vortex chamber. According to a preferred embodiment of the present invention, since the vortex passages are formed on the circumference of the piston, the diameter of the vortex chamber can be a maximum in spite of the presence of the vortex passages. This, in turn, allows for a reduced piston diameter and a more compact shock absorber.
Further, since the piston 100 is attached to the lower end of the piston rod 101 by pressure welding, the assembling of piston-and-rod assembly is simple to increase manufacturing efficiency.
In FIG. 1, the reference numerals 52 and 54 represent a spring seat and a steering knuckle respectively. However, these elements are only illustrated for the purpose of showing the specific construction of the shock absorber, and it should be appreciated that these are not always provided on a shock absorber of the present invention.
FIG. 4 shows a modification of the preferred embodiment of the piston of the shock absorber of FIGS. 2 and 3. In the embodiment of FIG. 4, the piston 200 is attached to the lower end of the piston rod 201, preferably by way of pressure welding, in a manner similar to the embodiment of FIGS. 2 and 3. The piston 200 is formed with a circular recess 202 on the lower surface thereof. The recess 202 is closed at a lower end thereof with a fitting 204 in order to define a vortex chamber 206. The vortex chamber 206 communicates with the upper chamber 48 in the cylinder of the shock absorber through vertical passages 208 and vortex passages 210. On the other hand, the vortex chamber 206 communicates with the lower chamber 50 via a central opening 212 formed in the fitting 204.
At the lower end of the piston rod 201, there is formed an axially extending groove 214. The vortex chamber 206 communicates with the groove 214 via a central opening 216 formed in a horizontal section of the piston 200. The groove, in turn, communicates with the upper chamber 48 through lateral passages 218 which extend transversely through the piston rod 201 adjacent a lower end thereof. The outer end of the lateral passages 218 are closed by a resilient closure member 220. As shown in FIG. 3, the resilient closure member 220 may be attached to the periphery of the piston rod 201 at one end thereof, the other end being movable from the periphery of the piston so that the fluid in the vortex chamber 206 can flow therethrough.
Therefore, in this embodiment, the piston-and-rod assembly can be easily assembled by way of pressure welding to increase the efficiency of manufacturing the shock absorber. Further, even though the construction of the piston is simple, enough space is provided for the vortex chamber to effectively work and produce a resistance against fluid flow by creating a vortex flow. Furthermore, the one-way valve formed in the lower end of the piston rod serves to relieve fluid pressure in the vortex chamber when the pressure in the vortex chamber becomes greater than that of a predetermined set pressure.
Thus, the present invention fulfills all of the objects and advantages sought thereto. | A vortex flow shock absorber includes a piston having a vortex chamber therein. The piston communicates with one fluid chamber defined in a absorber cylinder via a vortex chamber and with the other fluid chamber separated from the former by the piston via a flow restricting opening. One-way valve is provided in a piston rod which defines a fluid passage permitting one way flow of the fluid from the vortex chamber to one of the fluid chamber. The one-way valve is responsive to an excessive fluid pressure in the vortex chamber to relieve the fluid pressure exceeding a predetermined value. The piston and piston rod are attached together with pressure welding. This simplifies the assembling operation of the piston onto the piston rod. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention concerns a device for the control of the threads on a stitching machine. The output of modern stitching machines is so high that the control of the threads is extremely important. In contrast to the knitting machine, in which a very large number of threads are used, the feed is relatively low and the failure of a thread through thread breakage in a stitching machine means the loss of the material. This is all the more serious in that the number of the stitching seams for certain products is tending to decrease and the material feed rate is becoming higher and higher. Modern stitching machines operate with outputs of an average of 30-80 m/hr. In the production of auto upholstery often only two or three seams are stitched, with a speed of 100 m/hr being achieved.
2. Description of the Prior Art
This problem has been recognized and a solution has also been proposed. In Swiss Patent CH-PS357.955 a proposal is made to loop the needle thread from a supply spool around a roller and pass it through a terminal eye of a spring-loaded current-conducting contact arm. If the thread tension decreases as the result of a thread break, the contact arm presses on a contact bar and closes a circuit, whereby a relay is activated and the machine shut off. This system has proven its worth for stitching patterns with a relatively large number of stitching seams. With the very simple stitching patterns, such as cushion trimmings and auto upholstery with only a few stitching seams, which have become more and more prevalent recently, it has been found that when using only a few threads, the thread loop around the roller which is required to provide the thread tension does not work. Rather, just from the inertia in the system, the threads are frequently broken. Hence, in the stitching of auto upholstery, despite the high working speed, the work is performed without automatic thread control.
SUMMARY OF THE INVENTION
The present invention provides a thread controlling device that is particularly adapted for the control for stitching machines in the production of stitched products with only a few stitched seams. Further, the device can influence the location of the stitched seams.
The thread controlling device of this invention is characterized by the fact that a control regulates the thread feed according to a program of the program control of the stitching machine by means of a drive mechanism and that the thread breakage control device that indicates the break of a thread is connected with the program control.
BRIEF DESCRIPTION OF THE DRAWING
Objects, advantages and features of this invention will be apparent from the description together with the drawings showing preferred embodiments wherein:
FIG. 1 shows a schematic operation diagram of the thread control device;
FIG. 2 shows a schematic representation of a thread control device according to this invention; and
FIGS. 3a-c show different stitching variants that can be produced with the thread control device according to this invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Modern stitching machines, such as, for example, the AZ-Designer machine of the firm MECA S.N.C. in Cassano Magnago, Italy, have program control. By means of programmable magnetic discs, the user can stitch each stitching pattern desired by his customer fully automatically. The device based on this invention makes use of this feature.
In the operation diagram shown in FIG. 1, the program control of the stitching machine is indicated by 1. Corresponding to the pattern which is fed into the central program control 1 of the machine with a magnetic card or punched tape, control signals are sent to control 2 of the thread control device. This control device transforms the received signals and transmits them to step motor 3. Step motor 3 drives a roller which has all the threads being used looped around it and effects the corresponding thread feed 4. A thread break monitoring device 5 monitors each individual thread being used. When a break occurs, a back signal is given to the program control of the machine and the machine stops.
In contrast to the heretofore existing thread monitors for textile machines, in the device based on this invention not only is the thread monitored, but the thread feed of the needle thread is controlled. The control of the needle thread also has, of course, an effect on the shuttle thread.
The control 2 of the thread control device can take care of several functions. For example, the control can be so designed that the number of threads used in the stitching pattern can be adjusted. If, for example, all the stitching threads are required, then the feed roller hardly needs to be driven, since threads rotate the feed roller by themselves. The fewer the threads used, the more the step motor 3 must do for the feeding through the feed roller. If, as is quite usual in car upholstery, only two or three threads are required, then the feed must coincide exactly with the required thread length.
It is well known that a seam can be varied through the tension of the needle thread. FIGS. 3a-c show a cross section vertical to a quilting seam through quilting material. The form of a quilting seam as in FIG. 3a results when the tension of the shuttle thread is considerably greater than the tension of the needle thread. With the device based on the invention, this can be achieved by making the feed of the needle thread relatively large by means of the step motor and thereby the tension of the needle thread relatively low. If the tensions of the needle and shuttle threads are the same, the same amount of thread is used on either side and the approximately symmetrical seam form of FIG. 3b results. Finally, the tension of the needle threads can be raised so much that a seam form, as shown in FIG. 3c, results. These types of seams, as shown in FIG. 3c, have been hitherto unknown. The operator has always made an effort to obtain a stitching seam as shown in FIG. 3b. It was, in principle, possible to brake the individual needle threads, but this was never done in practice. The device based on this invention makes it possible now not only to work with any seam variant, but also to vary, at will, the type of seam during the stitching, which means that a more relief-like effect can be obtained.
FIG. 2 shows the thread control device according to the invention in a schematic representation. Needle thread 10 comes off the spool 11 and goes around a roller 12, which, because of its function, is called the feed roller. The feed roller 12, which is responsible for the follow-up of the needle thread 10, also correspondingly adjusts the thread tension. The feed roller 12 is driven by step motor 3 in accordance with control 2 of the thread controlling device. Thread 10 reaches needle 14 via guide rollers 13, which may be partly spring loaded.
Thread break monitoring device 5 monitors needle thread 10. The monitoring device 5 consists of a spring-loaded conductive contact arm 15 with terminal eye 15' around a needle thread 10 and a common contact bar 16 for all contact arms 15. All the contact arms 15 mounted on a conductive bar 17, as well as the contact bar 16, are connected with the program control 1 of the stitching machine by way of lines 18 and a relay, not shown. If the needle thread breaks or the thread tension becomes too small, contact arm 15 touches contact bar 16, closes the relay circuit and turns off the machine through the program control 1. This also happens if the thread break occurs beyond the thread disk brake 19, since thread 10 fed from the roller 12 is no longer tightened. On the other hand, if the not-shown shuttle thread breaks, less needle thread is used than is programmed, i.e., more thread is fed than is needed, and consequently the thread 10 again becomes slack, causing the contact 15-16 again to close.
An advantage of this invention is that with the described thread control device not only, as previously, can needle thread breakage be controlled, but in addition to this function, new quilting stitching variants can also be executed.
In a quilting-stitching machine with program control (1) it is possible by means of a device for the controlling of the needle thread, on the one hand, to monitor thread breaks and, on the other, to vary the stitching seam. For this purpose the thread (10) is carried around a feed roller (12) which effects the feed of the thread according to the stitching program through the control (2). The roller (12) is driven by a step motor (3). The thread feed is adjusted on the basis of the number of the threads used and the desired seam. The thread-break monitoring device (15-19) influences the program control (1) again and thereby also all the successive elements (2,3).
The device makes it possible to work with few threads (10), as is often desired in the production of upholstery.
Thread control means 2, may be of any suitable electronic circuitry as is known to the art, to activate mechanism means 3 in the manner as described above, such as relays.
The thread control device for stitching machines according to this invention comprises a program control means (1), a thread control means (2) controlling thread feed means (4) by means of activating mechanism means (3) according to a program of the program control means (1) of the stitching machine for controlling thread tension, and a thread-break monitoring device (5) consisting of several spring-loaded, current-conducting contact arms (15) each with a terminal eye (15'), through which a needle thread (10) is led from thread spool (11) and a contact bar (16), as well as a thread disc brake (19) for the maintenance of the thread tension of each thread, said thread-break monitoring device (5) that announces the breakage of a thread being connected with the program control means (1).
While in the foregoing specification this invention has been described in relation to certain preferred embodiments thereof, and many details have been set forth for purpose of illustration, it will be apparent to those skilled in the art that the invention is susceptible to additional embodiments and that certain of the details described herein can be varied considerably without departing from the basic principles of the invention. | Thread control device for stitching machines comprising a mechanism for applying torque to a feed roller around which the needle thread is fed to provide proper thread feed when a small number of threads are used and to provide control of seam variation. The device further has a thread break monitoring device signaling the program control in case of thread breakage to stop the device. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to new compositions comprising copolymers of tetrahydrofuran, ethylene oxide, and an additional cyclic ether.
2. Description of the Related Art
Homopolymers of tetrahydrofuran (THF, oxolane), i.e., polytetramethylene ether glycols, are well known for use as soft segments in polyurethanes. These homopolymers impart superior dynamic properties to polyurethane elastomers and fibers. They have very low glass transition temperatures but their crystalline melt temperatures are above room temperature. Thus, they are waxy solids at ambient temperatures and need to be kept at elevated temperatures to prevent solidification.
Copolymerization with a cyclic ether has been used to reduce the crystallinity of the polytetramethylene ether chains. This lowers the polymer melt temperature of the polyglycol and at the same time may improve certain dynamic properties of a polyurethane which contains such a copolymer as a soft segment. Among the comonomers used for this purpose is ethylene oxide, which can lower the copolymer melt temperature to below ambient, depending on the comonomer content. Use of copolymers of THF and ethylene oxide may also increase certain dynamic properties of polyurethanes, for example elongation at break, which for some end uses is desirable.
Copolymers of THF with ethylene oxide are well known in the art. Their preparation is described e.g. by Pruckmayr in U.S. Pat. No. 4,139,567 and U.S. Pat. No. 4,153,786. Such copolymers can be prepared by any of the known methods of cyclic ether polymerization, described for instance in “Polytetrahydrofuran” by P. Dreyfuss (Gordon & Breach, N.Y. 1982). Such polymerization methods include catalysis by strong proton or Lewis acids, by heteropoly acids, as well as by perfluorosulfonic acids or acid resins. In some instances it may be of advantage to use a polymerization promoter, such as a carboxylic acid anhydride, as described in U.S. Pat. No. 4,163,115. In these cases the primary polymer products are diesters, which need to be hydrolyzed in a subsequent step to obtain the desired polymeric glycols.
U.S. Pat. No. 5,684,179 to Dorai (Dorai) discloses the preparation of diesters of polytetramethylene ethers from the polymerization of THF with one or more comonomers. While Dorai includes 3-methyl THF, ethylene oxide, propylene oxide, etc., it does not describe a glycol copolymer of THF, ethylene oxide, and cyclic or substituted cyclic ethers.
Glycols formed as copolymers of THF and ethylene oxide offer advantages over homopolymer glycols in terms of physical properties. At ethylene oxide contents above 20 mole percent, the copolymer glycols are moderately viscous liquids at room temperature and have a lower viscosity than polytetrahydrofuran of the same molecular weight at temperatures above the melting point of polytetrahydrofuran. Certain physical properties of the polyurethanes prepared from THF copolymers surpass the properties of those polyurethanes prepared from THF homopolymers.
However, there are certain disadvantages connected with the use of ethylene oxide (EO) in these copolymers. EO is quite hydrophilic and can increase the water sensitivity of the corresponding polyurethanes when used in the required concentrations.
SUMMARY OF THE INVENTION
The invention is a copolymer glycol prepared by polymerizing tetrahydrofuran, ethylene oxide and at least one additional cyclic ether. The invention is also directed to a polyurethane polymer comprising the reaction product of at least one organic polyisocyanate compound and a copolymer glycol prepared by copolymerizing tetrahydrofuran, ethylene oxide and at least one additional cyclic ether. The invention is also directed to spandex filaments comprising the aforementioned polyurethane.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a glycol composition of matter comprising copolymers of THF, ethylene oxide, and one or more additional cyclic ethers. Herein, the term “copolymer” means a polymer formed from at least three monomers. Because incorporation of ethylene oxide into the polymer glycol increases the hydrophilic character of the subsequent polyurethane product, it is desirable to control or even minimize this hydrophilicity, and thereby decrease the water sensitivity of products ultimately made from these copolymers. The additional cyclic ethers or substituted cyclic ethers are more hydrophobic and offset the increase in hydrophilicity caused by the ethylene oxide comonomer. This serves to decrease the water sensitivity of compounds, such as polyurethanes that are made from the inventive copolymers. Examples of such hydrophobic monomers are alkyl substituted tetrahydrofurans and larger ring cyclic ethers that contain a smaller proportion of oxygen in the molecule than ethylene oxide. A copolymer glycol can be produced, containing tetramethylene oxide and ethylene oxide units in the polymer chain, as well as units of the additional polyether monomer distributed in a random fashion along the polymer backbone chain. It should be noted that alkyl-substituted oxolanes, such as 3-methyloxolane, are referred to as the corresponding alkyl substituted THF, i.e., as 3-methyl-THF in this case. Herein, the term “cyclic ethers” will be understood to include both unsubstituted and substituted forms.
The copolymers of the present invention can be made by the method of Pruckmayr in U.S. Pat. No. 4,139,567 using a solid perfluorosulfonic acid resin catalyst. Alternatively, any other acidic cyclic ether polymerization catalyst may be used to produce these copolymers, e.g., heteropoly acids. The heteropoly acids and their salts useful in the practice of this invention are the catalysts described e.g., by Aoshima, et al. in U.S. Pat. No. 4,658,065 for the polymerization and copolymerization of cyclic ethers.
A wide range of strong acid and superacid catalysts that are well known to those skilled in the art can be used for the copolymerization of cyclic ethers of this invention. These include, but are not limited to, fluorinated sulfonic acids, supported Lewis or Bronsted acids, and various zeolites and heterogeneous acid catalysts. Perfluorinated ion exchange polymers (PFIEP), such as the NAFION® PFIEP products, a family of perfluorinated sulfonic acid polymers are generally suitable for use at EO levls of about 25 mole % or greater. NAFION® is commercially available from E. I. du Pont de Nemours and Company, Wilmington, Del. (hereinafter, DuPont). Fluorosulfonic acids are widely used as catalysts, especially for the lower levels of EO. Heteropoly acids, (phosphotungstic acid, for example) are generally suitable over the range of EO levels used.
The molar concentration of ethylene oxide in the polymer is 1% to 60% and preferably 1% to 30%. The molar concentrations of the additional cyclic ethers is 1% to 40% and preferably 1% to 20%.
The cyclic ethers can be represented by Formula 1:
where
R is a C1 to C5 alkyl or substituted alkyl group,
n is an integer of value 3 to 4 or 6 to 9,
m is zero or 1 except that when n=4, m is 1.
Examples of cyclic ethers are as follows:
Ring C Chemical Name C3 oxetane, methyl-oxetane, and dimethyl-oxetanes, C4 alkyl-tetrahydrofuran such as 3-methyl-THF and 3-ethyl-THF, and 2-methyl-THF, C6 oxepane, C7 oxocane, C8 oxonane, and C9 oxecane
Although not represented by the formula above, 3,4-dimethyloxolane (3,4-dimethyl-THF) and perfluoroalkyl oxiranes, e.g., (1H,1H-perfluoropentyl)-oxirane, can be used as an additional cyclic substituted ether for the purposes of this invention.
The mole percent proportions of the monomers in the THF/EO/3-MeTHF copolymer is 3–50% EO, 5–25% of the 3-MeTHF, and the remainder is THF. Preferred mole percent ranges are 8–25% EO, 5–15% 3-MeTHF, and the remainder THF.
During the copolymerization process of this invention, the ethylene oxide acts as a polymerization initiator (or promoter) and copolymerization starts with opening of the strained 3-membered ring, quickly initiating ring opening of the other cyclic ethers of this invention. To the extent that the ethylene oxide, tetrahydrofuran, and a third monomer, such as an alkyl substituted tetrahydrofuran, combine hydrophobic and hydrophilic comonomer units, the deliberate control of composition affords novel polymer chains. These new copolymers are of value as “soft segments” in polyurethane polymers. They are particularly of value when used in making spandex.
“Spandex” means a manufactured fiber in which the fiber-forming substance is a long chain synthetic polymer comprised of at least 85% by weight of a segmented polyurethane. The segmented polyurethane can be made from a polymeric glycol, a diisocyanate, and a difunctional chain extender. In the preparation of the spandex polymers, the polymer is extended by sequential reaction of the hydroxy end groups with diisocyanates and diamines. In each case, the copolymer must undergo chain extension to provide a spinnable polymer with the necessary properties, including viscosity.
Polymeric glycols that can be used in making the polyurethane of the present invention can have a number average molecular weight of approximately 1500–4000. Diisocyanates that can be used include 1-isocyanato-4-[(4-isocyanatophenyl)methyl]benzene, (“4,4′-MDI”) 1-isocyanato-2-[(4-cyanatophenyl)methyl]benzene (“2,4′-MDI”), mixtures of 4,4′-MDI and 2,4′-MDI, bis(4-isocyanatocyclohexyl)methane, 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane, 1,3-diisocyanato-4-methyl-benzene, and mixtures thereof. When a polyurethane is desired, the chain extender is a diol, for example ethylene glycol, 1,3-propane diol, or 1,4-butane diol, and mixtures thereof.
Optionally, a monofunctional alcohol chain terminator such as butanol can be used to control polymer molecular weight, and a higher functional alcohol “chain brancher” such as pentaerythritol can be used to control viscosity. Such polyurethanes can be melt-spun, dry-spun, or wet-spun into spandex. When a polyurethaneurea (a sub-class of polyurethanes) is desired, the chain extender is a diamine, for example ethylene diamine, 1,3-butanediamine, 1,4-butanediamine, 1,3-diamino-2,2-dimethylbutane, 1,6-hexanediamine, 1,2-propanediamine, 1,3-propanediamine, N-methylaminobis(3-propylamine), 2-methyl-1,5-pentanediamine, 1, 5-diaminopentane, 1,4-cyclohexanediamine, 1,3-diamino-4-methylcyclohexane, 1,3-cyclohexane-diamine, 1,1-methylene-bis(4,4′-diaminohexane), 3-aminomethyl-3, 5,5-trimethylcyclohexane, 1,3-diaminopentane, m-xylylene diamine, and mixtures thereof. Optionally, a chain terminator, for example diethylamine, cyclohexylamine, or n-hexylamine, can be used to control the molecular weight of the polymer, and a trifunctional ‘chain brancher’ such as diethylenetriamine can be used to control solution viscosity. Polyurethaneureas are typically dry-spun or wet-spun when spandex is desired.
The practice of the present invention is demonstrated by Examples below which are not intended to limit the scope of the invention.
Materials
THF, 2-methyl-THF, fluorosulfonic acid, and phosphotungstic acid hydrate are available from Aldrich Chemical, Milwaukee Wis. The phosphotungstic acid hydrate was dehydrated by heating at 300° C. for at least three hours prior to use.
3-Methyl-THF, 3-ethyl-THF, and oxepane were prepared according to methods described in the literature.
EXAMPLES
Example 1
This example was provided to show copolymerization of THF, 3-ethyl-THF, and ethylene oxide. THF (160 g, 2.22 mols) and 3-ethyl-THF (40 g, 0.4 mols) were added to a 500 ml 4-neck round-bottomed flask, equipped with mechanical stirrer, dry ice condenser, thermometer, and gas inlet tube. 1,4-Butanediol (0.8 g, 0.01 mols) was added as a molecular weight controlling agent, together with 10 g of dry NAFION® NR-50, cryoground to less than 80 mesh. NAFION® NR-50 is a solid perfluorosulfonic acid resin in bead form, available from DuPont. The polymerization mixture was stirred and heated to 50° C. At this point ethylene oxide was added slowly via the gas inlet tube and the addition was continued until 8.3 g (0.19 mols) were added, which took about 4 hours. The EO feed was then shut off and the gas inlet system flushed with dry nitrogen. Heating was continued for another 15 minutes, and the polymerization vessel then cooled to 30° C. before filtration. The solid catalyst was recovered and could be reused. The polymer solution was vacuum dried at 100° C. at 0.2 mm Hg (0.027 kPa) pressure. A final product filtration gave 50 g (24%) of a clear, viscous polymer, which was characterized by Fourier Transform Infra-Red Spectroscopy (FTIR), Nuclear Magnetic Resonance Spectroscopy (NMR), and Gel Permeation Chromatography (GPC). It had the following properties and composition
Number Average Molecular Weight:
3100
THF content:
72 mol %
EO content:
25 mol %
3-ethyl-THF content:
3 mol %
Example 2
This example was provided to show copolymerization of THF, 3-Ethyl-THF, and ethylene oxide.
A 250-ml round-bottomed polymerization reactor was set up, equipped with a mechanical stirrer, dry ice reflux condenser with Drierite moisture protection tube, thermometer, and gas inlet tube. THF (26 g, 0.36 mol.), 3-ethyl-THF (13 g, 0.13 mol.), and dry NAFION catalyst powder (grade NR-50, 3 g) were added. The mixture was heated to 60° C. with stirring, under a slow stream of nitrogen. When the system had reached 60° C., ethylene oxide gas (EO) was added slowly through the gas inlet tube at a rate of about 6 g/h. EO addition was continued until a total of 6.5 g EO had been added. The EO feed was then shut off, and the gas inlet system flushed with nitrogen. Heating was continued for another 15 minutes, and then the polymerization vessel was allowed to cool to room temperature.
The polymer solution was separated from the solid catalyst by filtration, and any polymer attached to the catalyst was removed by washing with dry methanol. Unreacted monomer was removed from the solution by distillation, and the polymer residue was vacuum dried for 1 hour at 100° C. and 1 mm of Hg (0.13 kPa) pressure. A final filtration gave 36 wt % of a clear polymer with a number average molecular weight determined by end group titration to be 1075, and the following composition as determined by NMR analysis:
49 wt % THF,
20 wt % 3-ethyl-THF, and
31 wt % of EO.
Example 3
This example was provided to show copolymerization of THF, oxepane, and ethylene oxide. A 100-ml round-bottomed polymerization reactor was set up, equipped with mechanical stirrer, dry ice reflux condenser with Drierite moisture protection tube, thermometer, and gas inlet tube. THF(10 g, 0.14 mol.), oxepane (hexamethylene oxide, 10 g, 0.1 mol.), and dry NAFION catalyst powder (grade NR-50, 2 g) were added. 1,4-butanediol was added as a molecular weight controlling agent. The mixture was heated to 70° C. with stirring, under a slow stream of nitrogen. When the system had reached 70° C., ethylene oxide gas was added slowly through the gas inlet tube at a rate of 4.5 g per hour. EO addition was continued until a total of 9 g EO had been added. The EO feed was then shut off, and the gas inlet system flushed with nitrogen. Heating was continued for another 15 minutes, and then the polymerization vessel was allowed to cool to room temperature.
The polymer solution was separated from the solid catalyst by filtration, and any polymer attached to the catalyst was removed by washing with dry methanol. The polymer was isolated from the solution by vacuum drying for 1 hour at 100° C. and 1 mm of Hg (0.13 kPa) pressure. A final filtration gave 45 wt % of a clear polymer with a number average molecular weight determined by end group titration to be 2420, and the following composition as determined by NMR analysis:
45 wt % THF,
20 wt % oxepane, and
35 wt % of EO.
Example 4
This example was provided to show copolymerization of THF, 3-Methyl-THF, and ethylene oxide.
THF (800 g, 11.1 mole) and 3-methyl-THF (100 g, 1.15 mole) were added to a 2-liter 4-neck round-bottom polymerization reactor, equipped with a mechanical stirrer, dry ice condenser, thermometer, and gas inlet tube. 1,4-butanediol (4 g, 0.033 mole) was added as a molecular weight controlling agent, and dry NAFION pellets (grade NR-50, 30 g) added as a polymerization catalyst.
The polymerization mixture was stirred and heated to 50° C., when ethylene oxide was added slowly added via the gas inlet tube. Ethylene oxide addition was continued until 55 g (1.25 mole) had been added over a period of about 4 hours. The ethylene oxide feed was then shut off and the gas inlet system flushed with nitrogen. Heating was continued for another 15 minutes, and then the polymerization vessel was cooled to 35° C. before filtration. The solid catalyst residue was washed and could be recycled. The polymer solution was vacuum dried for 1 hour at 100° C. at 2 mm Hg pressure (0.27 kPa). A final product filtration gave a clear viscous polymer with the following typical properties:
M n :
2700
Viscosity:
10.5 poise (1.05 Pa · s) at 40° C.
Melt temp.:
−3.9° C.
EO Content:
28 mol %
3-methyl-THF Content:
8 mol %
Examples 5–15
These examples demonstrated copolymerization of THF, 3-Methyl-THF, and ethylene oxide using fluorosulfonic acid (FSA) catalyst.
The procedure for each of these examples (Table 1) is as follows: A dry baffled and jacketed glass reactor was equipped with a thermocouple, a fritted glass gas inlet for nitrogen and ethylene oxide, a solid carbon dioxide condenser with outlet, and a mechanical stirrer. The 3-MeTHF was charged to the flask as a 55% solution of 3-MeTHF in THF with additional THF to give the monomer loading as shown in Table 1 and cooled to 10–15° C. The flask was swept with nitrogen and fluorosulfonic acid was added dropwise over 3–5 min through a dry addition funnel. The reaction mass was then heated to the reaction temperature and ethylene oxide was added over about 3 h. Agitation to maintain a uniform temperature throughout the reaction mass was provided. The temperature of the increasingly viscous contents was allowed to rise to, but not to exceed, 45° C. Control of the ethylene oxide feed rate was used to moderate the temperature.
To terminate and neutralize the reaction, the carbon dioxide condenser was replaced by a simple distillation head and hot water (600 mL) was added. The flask contents were heated to 100° C. to remove a THF/water distillate. A nitrogen flow was maintained to speed the distillation. When the THF was stripped off, the stirring was stopped and the contents were allowed to separate. The water layer was removed, and the organic layer was then washed twice with two 600 mL batches of hot water. After the second wash, 15 g of calcium hydroxide was stirred in thoroughly, precipitating additional water, which was removed. Additional hydroxide was added in small portions until the pH was 7–8. The polymer mix was maintained at 80° C. to maintain low viscosity.
To isolate the polymer, the neutralized wet polymer was stripped under vacuum at 90° C. Solids were removed by filtration through a diatomaceous earth mat on a Whatman #1 filter paper on a steam-heated Buchner funnel. The haze-free polymer was weighed, the molecular weight determined by end group titration, and the composition determined by 1 H NMR. These data are summarized in Table 2.
TABLE 1 3- Rxn MeTHF FSA time Rxn Temp Ex. THF (g) EO (g) (g) (g) (hr) (° C.) 5 663 37.1 176 37.1 4.4 40 6 663.6 37.1 176.4 37 2.3 30.1–34.6 7 663.6 37 176.4 37.2 2.3 30.7–39.2 8 663.6 37 176.4 37.7 4 34.4–41.2 9 1448 81 385 80.8 4 35–40 10 1448 53.2 385 80.8 4 35 11 2949 204 647 141.4 4 35–41 12 2949 204 647 141.4 4.25 32–42 13 2768 204 792 75.1 4 25–32 14 2768 204 792 74.6 3.7 15–22 15 2768 204 792 75.9 4.5 10.5–31
R×n in the table above means reaction.
TABLE 2
% 3-
Melt Point
Ex.
Conversion
% EO
MeTHF
Mn
(° C.)
5
56
4.8
9.5
1804
14.8
6
52.9
5.0
10.0
2166
7.79
7
NA
4.4
9.3
2244
9.89
8
63.9
5.4
9.6
1657
7.39
9
51.6
4.7
9.6
1778
16.15
10
51.1
2.9
9.3
1996
17.89
11
56.2
6.4
9
2274
17.18
12
50.6
7
9
2000
16.14
13
4.2
11.8
8.1
843
14.97
14
2.9
13.3
11.3
660
4.21
15
16.3
9
11.2
1085
11.05
Examples 16–20
These examples are provided to show copolymerization of THF, 3-Methyl-THF, and ethylene oxide using anhydrous phosphotungstic acid (PTA) catalyst.
A 5-L baffled jacketed reactor was equipped with a thermocouple, ethylene oxide and nitrogen inlet, a dry ice condenser with N 2 exit, and a mechanical stirrer. The equipment was dried at 100° C. with a N 2 sweep. The THF, water, and the anhydrous PTA were added to the flask and cooled (see Table 3). The 3-MeTHF was charged to the flask as a 55% solution of 3-MeTHF in THF with additional THF to give the monomer loading as shown in Table 3 and cooled to 10–15° C. The reactor was swept with nitrogen and the stirrer set for 250 rpm. The ethylene oxide was added steadily over a period of about 2 to 4 hours, with cooling to maintain the specified reaction temperature. After all of the ethylene oxide was added, stirring was continued until the total reaction time was completed. After the reaction period, 1 L of de-ionized water was added and the mixture stirred for at least 30 min. at 45° C.
The crude copolymer was purified by diluting the reaction mixture with an equal volume of methanol at 45° C., and passing the methanolic solution through a column packed with a weak-base ion exchange resin to absorb the acid catalyst. The unreacted THF, methanol, and water were the removed in vacuo. Solids were removed by filtration through a diatomaceous earth mat on a Whatman #1 filter paper on a steam-heated Buchner funnel. The haze-free polymer was weighed, the molecular weight determined by end group titration, and the composition determined by 1 H NMR. These data are summarized in Table 4.
TABLE 3
EO
3-
Rxn
Rxn
ADDN
MeTHF
time
temp
TIME
Ex.
THF (g)
EO (g)
(g)
PTA (g)
(hr)
(° C.)
(hr)
16
2808
178
792
130
4.1
−4–4
3.1
17
2808
178
792
75.6
4
−4.4–1.5
2.9
18
2943
70.8
657.3
75.6
6
−4.8–0.4
2.33
19
2943
123
657
75.6
5
−1–3.6
3.83
20
2988
162
612
75.6
5
14–22
4.8
TABLE 4
Melt
Ex.
Conversion
% EO
% 3-MeTHF
Mn
Point (° C.)
16
59
14.6
12
3420
−0.37
17
53.6
14.45
12.9
4438
−3.21
18
26.7
15.2
10.2
2233
4.46
19
46.6
13.9
10.35
2194
7.37
20
66.3
12.1
8.6
4180
10.02
Example 21
This example is provided to show copolymerization of THF, 2-methyl-THF, and ethylene oxide. A 250-mI round bottom polymerization reactor was set up, equipped with mechanical stirrer, dry ice reflux condenser with Drierite moisture protection tube, thermometer, and gas inlet tube. Tetrahydrofuran (THF, 25 g, 0.35 mol.), 2-methyl-THF (75 g, 0.75 mol.), and dry NAFION catalyst powder (grade NR-50, 6.5 g) were added. The mixture was heated to 60° C. with stirring, under a slow stream of nitrogen. When the system had reached 60° C., ethylene oxide gas (EO) was added slowly through the gas inlet tube at a rate of about 6 g per hour. EO addition was continued until a total of 17 g EO had been added. The EO feed was then shut off, and the gas inlet system flushed with nitrogen. Heating was continued for another 15 minutes, and then the polymerization vessel was allowed to cool to room temperature.
The polymer solution was separated from the solid catalyst by filtration, and any polymer attached to the catalyst was removed by washing with dry methanol. The polymer was isolated from the solution by vacuum drying for 1 hour at 100° C. and 1 mm of Hg (0.13 kPa) pressure. A final filtration gave 30 wt % of a clear polymer with a molecular weight determined by end group titration to be 2000, and the following composition:
25 wt % THF,
40 wt % 2-Methyl-THF, and
35 wt % of EO,
as determined by NMR analysis. | A copolymer with recurring constituent units derived by polymerizing tetrahydrofuran, ethylene oxide and at least one additional cyclic ether that can be substituted or unsubstituted that decreases the hydrophilicity imparted to the copolymer by the ethylene oxide. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to the field of data information processing, and in particular to simplifying user access to information stored in relational databases.
2. Discussion of the Related Art
Relational databases are used in numerous applications to store a wide variety of data. Software applications are commercially available for creating relational databases and storing data therein. Examples of these software applications include products such as SYBASE SQL Server, Microsoft SQL Server, Oracle, and IBM DB2. While these products provide the capability to store data in various formats, they generally do not provide means by which a typical user of the database system can cross-reference information contained within separate catalogs or tables of the database. Cross-references between related tables are typically preprogrammed into the database by a system administrator or some other individual having knowledge of a programming language such as SQL.
FIG. 1 shows an example of a data base 10 containing eight tables of information including a Customer table 12, a Corp table 14, a Freq -- Flyer table 16, a Serv -- Hist table 18, a Service -- ID table 20, a Serv -- Desc table 22, a Travel -- Dtl table 24, and an Airline table 26. Each of the tables contain several columns of information. As an example, the Freq -- Flyer Table 16 contains an Airline -- I.D. column 16a, a Customer -- I.D. column 16b, and a Points -- Amt column 16c. Tables 12 through 26 are shown connected by interconnecting lines 28 through 48 each of which connect a column of a first table to a column of a second table having the same column name as the column of the first table. These interconnecting lines connect related tables and allow a user to easily access the information contained in a related table without making a new query into the database. For example, when a user is utilizing the Customer table 12, the user may wish to see additional information regarding a particular customer's company. If the cross-reference connection 28 exists, the user can directly access the information in the Corp table 14 from the Customer table 12 rather than exiting the Customer table and accessing the Corp table 14.
In the existing database management systems, the relationships shown in FIG. 1, are preprogrammed into the database by a system administrator using complex programming techniques and a programming language such as SQL. The system administrator when constructing a database will typically provide some relationships between related tables, but will not provide all of the relationships that inherently exist because of the programming time required for accomplishing this and because the system administrator may not be aware of all of the relationships that exist between tables in the database. Additional problems and limitations are created for the user when the system administrator is not familiar with the needs of the user, and therefore, not familiar with which relationships the user would find most useful. When a user of the database management system requires additional joining of the tables in the database, beyond that which is originally programmed by the system administrator, a request must be made to the system administrator or some other individual familiar with the programming language of the database to provide the system with this capability. Additional programming must then be performed to provide the user with the requested capability.
Graphical interface programs for accessing databases are commercially availabe, however, these programs require that a system administrator define the relationships that exist in the database as discussed above. An example of a database graphical interface program is FindOut| Analyst from Open Data Corporation, Lexington, Mass. Findout| Analyst allows a user to navigate a database to find information quickly, however, it requires that a dictionary exist that defines the relationships in the database. In the prior art systems, this dictionary must be generated manually by a system administrator as described above.
SUMMARY OF THE INVENTION
Embodiments of the present invention provide a process and an apparatus for simplifying a user's access to the information contained within a relational database by enabling the user to interactively navigate the database taking advantage of the relationships that inherently exist between tables in the database. These capabilities are provided without the need for extensive programming by a system administrator. By providing these capabilities, embodiments of the present invention overcome the shortfalls discussed above.
One embodiment of the present invention is directed to a data processing apparatus for accessing the information contained within a relational database. The apparatus includes a central processing unit that interacts with the database, a user interface, and a memory containing a dictionary builder. The dictionary builder is comprised of modules that scan selected portions of the database, and construct a dictionary of the database. The dictionary contains classes and attributes that define the relationships that exist between the tables contained in the database.
In another embodiment of the present invention, the dictionary builder includes a user interface and customization module that allows a user of the data processing system to edit the dictionary to customize the dictionary to the user's needs.
In yet another embodiment of the present invention, the dictionary builder includes a mapping module that maps classes and attributes of the dictionary to the tables and columns of the database to allow access to the object values contained within the database.
In still another embodiment of the present invention, the dictionary builder includes a form and menu construction module that provides the user with standard forms for accessing information in the database.
The present invention is also directed to a method for simplifying access to information contained within a relational database. The method includes steps of characterizing the database to determine the relationships that exist among the tables contained within the database, and constructing a dictionary containing attributes that define the relationships discovered during the characterization step.
In another embodiment of the method of the present invention, the method includes an additional step of customizing the dictionary based upon selections made by a user.
In yet another embodiment of the method of the present invention, the method includes an additional step of mapping the attributes contained within the dictionary to the database.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of the present invention shall appear from the following description of an exemplary embodiment, said description being made with reference to the appended drawings, in which
FIG. 1 shows tables within a database that may be used in conjunction with the present invention;
FIG. 2 shows a block diagram of an embodiment of the invention;
FIG. 3 shows a block diagram of a dictionary builder according to an embodiment of the invention;
FIG. 4 shows the process by which the catalog analysis module scans the database in one embodiment of the invention.
FIG. 5 shows the process by which the catalog analysis module scans the database in another embodiment of the invention.
FIG. 6 shows the process by which the dictionary construction module constructs the dictionary according to one embodiment of the invention.
FIG. 7 shows the process by which the dictionary construction module creates relationship attributes according to one embodiment of the invention.
FIG. 8 shows the process by which the mapping module maps the attributes of the dictionary to the database according to one embodiment of the invention.
FIG. 9 shows an example of a main menu generated by one embodiment of the invention.
FIG. 10 shows an example of a basic form generated by one embodiment of the invention.
FIG. 11 shows an example of a list form generated by one embodiment of the invention.
DETAILED DESCRIPTION
A detailed description of embodiments of the present invention will now be described in connection with FIGS. 1-8. Similar reference numbers in the drawings indicate similar structures. A data processing system comprising one embodiment of the invention is shown in FIG. 2. FIG. 2 shows a Central Processing Unit (CPU) 110 which typically includes a microprocessor and control logic. The CPU 110 may be a 486 personal computer having at least 12 megabytes of Random Access Memory (RAM) using the DOS operating system, version 5.0 or higher, and Windows version 3.1 or higher. Alternatively, the operating system for the personal computer may be the IBM OS/2 operating system, version 2.1 or higher. Connected to the CPU 110 is a user interface 114. The user interface 114 is coupled to the CPU 110 via a user interface bus 124. The user interface 114 may be a computer display, keyboard, and mouse. The user interface 114 is typically a physical entity by which the user inputs commands to and receives information from the CPU 110. The user interface 114 may also include a touch screen, a joystick, a track ball, a touch pad, or a similar device. Normally, a display represents the primary output of CPU 110, but printed media and electronic output may also be used. A memory 112 is also coupled to the CPU 110 through a memory bus 126. The memory 112, as well as the remote memory 122, may be a hard drive, floppy disk, electronic memory such as a random access memory (RAM), erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), magnetic, optical, or magneto-optical recording media, tapes, or other non-volatile linear access media or a combination of these. The CPU 110 is also coupled to a LAN server 116a through a LAN interface bus 128. The LAN server 116a is coupled to a second LAN server 116b through a LAN 118. The LAN server 116b is coupled to a remote memory 122 through a LAN interface bus 120. Through the LAN 118, the CPU 110 is able to access the remote memory 122. The remote memory 122 contains at least one database 130 in which information is stored in catalogs, each of which contains one or more tables of information. Alternately, the database may be contained in memory 112 or in an additional memory coupled to the CPU 110.
Memory 112 contains a dictionary builder 50 having program modules for providing the CPU 110 with instructions for enabling a user, through the user interface 114, to access information contained in the database 130. The dictionary builder 50 may also reside in the remote memory 122, or in an additional memory coupled to the CPU 110.
The dictionary builder 50 is comprised of five interconnected modules as shown in FIG. 3. A catalog analysis module 52 is connected to a dictionary construction module 54 which is connected to both a mapping module 58 and the user interface and customization module 56. The mapping module 58 is connected to both the user interface and customization module 56 and the form and menu construction module 60. The function of each of these modules is described below.
The catalog analysis module 52 analyzes the information contained within the database and provides the dictionary construction module 54 with the results of the analysis. The steps conducted in performing this analysis will be described with reference to FIG. 4. Initially, in step 202, the catalog analysis module receives information from a user through the user interface 114. The information received from the user defines the schema of the dictionary and includes which database and which catalogs and tables within the database are to be analyzed by the catalog analysis module. The information contained within a database is typically organized in one or more catalogs containing one or more tables. In steps 204 and 206, one of the specified catalogs and one of the tables within the catalog are selected. In steps 208 through 216, the catalog analysis module creates a table object for the table, creates a column object for each column contained in the table, creates an I.D. key for each primary key of the table, and also creates an I.D. key for each unique set of columns of the table, and creates a join key for each foreign key of the table. The objects and I.D. keys created in steps 208 through 216 are identifiers of the items contained within the schema that are later used by the dictionary builder module to define the contents of the schema. As indicated in steps 218 and 220, the catalog analysis module repeats steps 208 through 216 for each table of each catalog selected in step 202.
In order to better understand the terms used in the functional description of the catalog analysis module, reference is made to FIG. 1. FIG. 1 shows eight sample tables 12-26 from a sample database 10. Using the Customer table 12 as an example, the catalog analysis module creates a table object for the table and creates a column object for each of the columns 12a through 12j. The catalog analysis module creates an I.D. key for the primary key of the table. In table 12, the Customer I.D. is defined as the primary key of the table by the database and will become the I.D. key for this table in the dictionary. The catalog analysis module also creates an I.D. key for each set of columns indicated as a unique set by the database. For example, the Home -- Phone column 12h of the Customer table 12 is also a unique column, assuming that no two customers have the same home phone number. For each foreign key in the table, the catalog analysis module creates a join key. A foreign key indicates that another table exists which is related to the table containing the foreign key. Customer table 12 has a foreign key indicating that the Corp -- I.D. Column 12j is related to Corp table 14. The catalog analysis module will create a join key corresponding to this foreign key.
After completing the initial scan of the database, the catalog analysis module, depending on a selection made by the user, may perform a second scan of the database further analyzing the contents of the database to see if additional join keys may be created. As shown in FIG. 5 in steps 224 through 242, the catalog analysis module examines each table that has an I.D. key for each catalog within the schema defined by the user and compares the table with each other table to determine if the other table has a join key referencing the I.D. key, and if not, it compares each of the columns of the other table with columns of the I.D. key of the table. If every column of the I.D. key has a corresponding column in the other table with the same name and data type, a join key is created in the other table that references the I.D. key. The catalog analysis module repeats this procedure for each of the tables contained within the schema.
The function of the dictionary construction module will now be explained with reference to FIG. 6. The dictionary construction module 54 in FIG. 3 constructs a dictionary of the data contained within the schema defined by the user based upon the analysis results received from the catalog analysis module according to the procedures set forth in FIG. 5. First, as shown in steps 302-306 in FIG. 5, the dictionary construction module identifies each table that is a source table for a class. A source table is defined as a table that has an I.D. key and is not a pure join table. A pure join table is a table in which all of the columns are members of one or more join keys. Referring to FIG. 1, the Service -- I.D. table 20 is a pure join table. For each of the source tables identified, the dictionary construction module creates a class name in step 308. The table is defined as the source table for the class.
The dictionary construction module in step 308 creates two class names for each class by converting the table name to a name that is easier for the end user to recognize, and by creating a plural form of the name. The class name is created from the table name by using the following four rules:
1) Table names that contain a lower-case letter, followed by an upper-case letter have a space inserted between the letters creating two separate words. As an example, a table having a table name of "ServiceDescription" will have a class name of "Service Description".
2) Underscore characters in a title of a table are converted to spaces. For example, referring to FIG. 1, the name of the Travel -- Dtl table 24 will be converted to "Travel Dtl".
3) Individual words are converted to mixed case by forcing the first character of the word to upper-case, and the subsequent characters to lower-case.
4) The characters "i.d.," if they exist as a separate word, are converted to upper-case.
After the class name is created, a plural from of the name is created by using the following five rules:
1) Locate the last letter of the name, and if the name has more than one letter, the next to last letter.
2) If the last letter of the name is "s", add the suffix "es".
3) If the last letter in the name is "y" and the next to last letter in the name is a vowel, add the suffix "s".
4) If the last letter is "y" and the next to last letter is not a vowel, remove the "y" and add the suffix "ies".
5) If the last letter is neither "s" nor "y", add the suffix "s".
After creating the class names for a table in step 308, the dictionary construction module creates descriptive attributes for each column of the table, and a name attribute is created for each column of the table that is part of an I.D. key as shown in steps 310 and 312 in FIG. 6. The process for generating the descriptive attributes and the name attributes is substantially the same as that described above for the class name.
As shown in step 314 of FIG. 6, the dictionary construction module next creates relationship attributes from the join keys of the table. The process by which the dictionary construction module creates relationship attributes is described with reference to FIG. 7. For each join key of a source table, the dictionary construction module determines whether the join key is joining individual items, an individual item and a list, or a first list and a second list. Based upon these distinctions, the dictionary construction module will create either item attributes or list attributes in either the source table, the detail table or both. This is accomplished as shown in steps 324 to 336 of FIG. 7.
Three examples from FIG. 1 will be used in conjunction with FIG. 7 to describe how the dictionary construction module creates the list and item attributes. The Travel -- Dtl table 24 from FIG. 1 will be used in the first example. A table containing a join key is defined as the detail table of the join key, and the corresponding table having the I.D. key to which the join key refers is defined as the master table for that join key. As previously discussed, a source table is defined as a table that has at least one I.D. key and is not a pure join table. The Travel -- Dtl table 24 is a source table for the Travel Dtl class and it contains a join key for connecting the Travel -- Dtl table 24 with the Customer table 12 as shown by the interconnecting lines 30 and 34. The Customer table is the master table for this join key and the Travel -- Dtl table is the detail table.
The particular join key described above will now be used to follow the steps shown in FIG. 7. In step 324 the join key of the Travel -- Dtl table was selected. The corresponding master table, the Customer table, is a source table for a class and the Travel -- Dtl table is also a source table for a class. Therefore, the result of step 326 of FIG. 7 will be "Yes", and an item attribute will be created in step 330 such that the Travel -- Dtl table is the source table of the local class of the item and the Customer table is the source table of the content class of the item. The result of step 332 will be "No" since the join key column, Customer I.D., is not an I.D. key of the Travel -- Dtl table. The Customer I.D. column does not have a unique set of values in the Travel -- Dtl table. Each of the customers may have purchased more than one ticket and have traveled more than one time. In step 334, a reciprocal list attribute will be created such that the Customer table is the source table for the local class of the list and the Travel -- Dtl table is the source table of the content class of the list.
The Freq -- Flyer table 16 will be used in the second example to describe the process used by the dictionary construction module in FIG. 7. The Freq -- Flyer table has a join key connecting the Freq -- Flyer table with the Customer table 12 as indicated by connecting lines 30 and 32. This is the join key selected in step 324 of FIG. 7. The corresponding master table, the Customer table, for this join key is a source table for a class, and the Freq -- Flyer table is also a source table, so the result of decision step 326 will be "Yes". An item attribute will be created in step 330 such that the Freq -- Flyer table is the source table for the local class of the item and the Customer table is the source table for the content class of the item. The result of decision step 332 will also be "Yes" since the column of the join key is an I.D. key of the Freq -- Flyer class. Therefore, an item attribute will be created in step 336 such that the Customer table is the source table for the local class of the item and the Frequent Flyer table is the source table of the content class of the item.
The Service -- I.D. table 20, and the join key corresponding to the Customer table, indicated by connecting lines 30 and 31, are used in the third example to describe the process of FIG. 7. The Service -- I.D. table is not a source table for a class, and therefore, the result of step 326 will be "No". All of the columns of the Service I.D. table are join keys, and therefore, the Service I.D. table is acting as a pure join table. In step 328, the dictionary construction module will create pairs of reciprocal relationships between the local class generated by the Customer table and the local classes generated by the Travel -- Dtl table and the Serv -- Desc table. Each side of the reciprocal is a list attribute whose local class has one of the master tables as its source table and whose content class has the other master table as its source.
After the list and item attributes have been created, the dictionary construction module creates display text for each of the classes. This is shown as step 318 in FIG. 6. The display text is the text that is shown to the user whenever an element of the class is viewed on a form. When an element of a class is viewed, the display text is filled in by replacing an attribute name with the attribute value for that element. For example, if the display text for the customer class is "\:last name:\,\:first name:\\:middle initial:\.", then when the object that represents the customer named Pete Jones is displayed, the displayed text will be equal to "Jones, Peter P.". Note that the names and initials are the values of the attributes. An important step within the creation of the displayed text is replacing name attributes with item attributes. This is done so that when an item attribute is used in the displayed text, it is the displayed text of the items content class that is substituted for the item attribute name. This leads to very readable and meaningful displays for the user. As an example, an item attribute corresponding to customer was created in the Frequent Flyers class during the creation of item attributes described above. In the displayed text, rather than displaying the item attribute name, customers, it is the actual customer name that will be displayed. Once the displayed text is created, the dictionary construction module provides the user interface customization module with the contents of a newly created dictionary.
The user interface and customization module 56 utilizes standard graphical user interface (GUI) techniques such as those known in a windows environment to allow a user to edit the dictionary created by the dictionary construction module. This allows the user to customize the dictionary created by the dictionary construction module. The user accesses the user interface and customization module through the user interface and the CPU.
The function of the mapping module 58 will now be described. Referring to FIG. 3, the mapping module 58 receives the dictionary created by the dictionary construction module 54 and any user modifications to the dictionary from the user interface and customization module 56. The mapping module 58 connects the classes and attributes of the dictionary to the tables and columns in the database so that the proper commands can be generated to retrieve the object values in the database. The connection of the dictionary to the database is accomplished by assigning a map index and a map column for each descriptive, name, and relationship attribute in the dictionary as shown in steps 410 through 462 in FIG. 8. The map columns and the map index can then be used to generate the appropriate commands, using for example SQL, to provide the necessary connections between the database and the dictionary. The appropriate SQL commands may be generated from the results of the mapping module using a tool such as FindOut| Analyst available from Open Data Corporation, Lexington Mass.
The process by which the map index and the map columns are determined are described below with reference to FIG. 8. A different mapping procedure is used depending on whether the attribute to be mapped is an item attribute, a list attribute, name attribute or a descriptive attribute. Each of these procedures is described below.
One of the attributes to be mapped is selected in step 410 of FIG. 8. In step 420, it is determined whether the selected attribute is an item attribute. The procedure for mapping an item attribute is shown in steps 430 through 434 of FIG. 8. In step 430, the mapping module determines whether the detail table is the same as the source table for the item's local class. If the result of step 430 is "Yes", then, in step 432, the mapping module sets the map index to 1 for this item attribute and maps the item attribute to one column of the join key of the detail table. If the result of step 430 is "No", then in step 434, the mapping module sets the map index to 2 plus the map offset, and maps the item attribute to one column of the detail table's I.D. key. The map offset of a given attribute is computed by counting the preceding relationship attributes on the same local class that have the same content class as the given attribute, discarding self-referencing items. A self-referencing item is an item whose content class is the same as its source class.
The procedure for mapping a list attribute is shown in steps 440 through 444. In step 440, the mapping module first determines whether the list attribute is reciprocal to a list or to an item. If the result of step 440 is "Yes", indicating that the reciprocal attribute is an item, then the mapping module sets the map index to 2 plus the map offset, and maps the list attribute to one column of the detail table's I.D. key. If the result of step 440 is "No", indicating that the reciprocal attribute is a list attribute, then in step 444, the mapping module sets the map index to 2 plus the map offset, and maps the column to a column of the join key in the pure join table, such that the master table of the join key is the source table for the content class of the list.
The procedure used by the mapping module to map a name attribute is shown in steps 450 through 460 of FIG. 8. The mapping module in step 450 sets the map index to 1 and maps the name attribute to the corresponding column of the source table from which the name attribute was created. Additionally, the mapping module, in step 452 determines whether any join keys refer to the corresponding creating column of the name attribute. If the result of step 452 is "No", then the mapping module selects another attribute and repeats steps 410 through 460 until all of the attributes have been mapped. If the result of step 452 is "Yes", then in step 454, the mapping module locates the join key. In step 455, the join key is examined to see if it generates a relationship. If the result of step 455 is "Yes", then in step 456, the mapping module locates the column of the join key that refers to the creating column of the name attribute. The mapping module then computes the map index for the relationship attribute corresponding to the join key as is done in steps 430 through 434 or in steps 440 through 444. The name attribute is then mapped to the join key column determined in step 456 using the map index computed in step 458.
In step 424, if the attribute is not a name attribute, then it must be a descriptive attribute. The procedure for mapping a descriptive attribute is outlined in step 425. The map index is set to 1 and the descriptive attribute is mapped to the column that was used to create the descriptive attribute. The results of the map index are saved in the memory with the dictionary builder.
The function of the form and menu construction module 60 will now be described. The form and menu construction module constructs the shell of an application for a user by constructing a collection of forms. These forms can be used by a user in generating reports and for searching the database using a program such as FindOut| Analyst. Several different types of forms can be developed depending on the needs of a particular user. A main menu is one example of a form that can be created. The main menu may provide a button field for every class that is contained in the dictionary, so that the user can select a particular class by selecting the button corresponding to the class. An example of a main menu corresponding to the example of FIG. 1 is shown in FIG. 9. The main menu 500 contains a button field 510 containing a button 520 for each table from FIG. 1. The menu also contains a title 540 which may be defined by the user.
Other forms may be created including a basic form having three columns. The first two columns display the names and values of non-list attributes of a class. The third column shows a button for every list attribute. An example of a basic form 550 for the customer class is shown in FIG. 10. The form 550 includes a first column 560 that lists the attribute names, a second column 570 that lists the attribute values, and a third column 580 containing buttons for the list attributes.
Another form that may be created is a list form that provides a user with a list of the attributes of a class along with the corresponding values of the attributes. FIG. 11 shows an example of a list form 600. The form includes a title 630, a row of attributes 610, and two rows of values 620 of the attributes. It is envisioned that other forms and menus could be created by the form and menu construction module in addition to the examples provided above.
Several implementations of the invention are envisioned. The above description has focused on an embodiment of the invention in which the modules comprising the dictionary builder are contained in a memory coupled to a CPU. Further implementations of the invention may include software structure residing on a general purpose computer or a standalone personal computer. Also special purpose hardware may be dedicated to performing the functions of the dictionary modules discussed above.
Having thus described particular embodiments of the invention, various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications and improvements are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description is by way of example only, and not intended to be limiting. The invention is limited only as defined in the following claims and the equivalents thereto. | Simplified access to relational databases is achieved. The inherent relationships that exist between tables in a relational database are detected and a dictionary is constructed that contains attributes that defines the relationships that exist within the database. The attributes of the database contained within the dictionary are mapped to objects of the database so that a user can navigate the database without using a database programming language using menus created from the dictionary. | 8 |
BACKGROUND OF THE INVENTION
Printed circuit boards are manufactured by plating a thin layer of copper on an epoxy-glass cloth laminate board of uniform thickness. A predetermined pattern of holes is then drilled to accommodate various electrical components. A film of partially polymerized photoresist plastic is deposited on the laminate over the copper plating. Photoresist films are commonly composed of acrylic resins, polyvinyl cinnamates, diazo compounds, phenol-formaldehydes, or other similar film-forming materials. This film is further polymerized, or cross-linked, by the action of ultraviolet light, into a hard chemically resistant film.
By masking with an appropriate glass or plastic material the resist film is selectively hardened by the exposure to light in specific predetermined areas, while the resist film in the masked areas is left unchanged. The unchanged resist film is then dissolved in a "developer" by a solvent such as 1,1,1-trichloroethane or a solution of butoxyethanol and sodium carbonate or similar solutions. The copper in the cleaned areas may then be removed by etching or additional copper and other metals may be plated thereon. In either event, it then becomes necessary to remove the exposed hardened resist film from the laminate.
It is known that such resist films can be removed by the action of strong organic solvents, such as methylene chloride or trichloroethylene.
It is known also that many paint and varnish removers are based on methylene chloride. Many of these also contain an alcohol and one or more other additives. Thus, U.S. Pat. No. 3,650,969 discloses a composition for removing paint which comprises dichloroalkanes of 1 to 2 carbon atoms, an aliphatic monohydric alcohol containing 1 to 3 carbon atoms, and hydrogen flouride and water. U.S. Pat. No. 3,600,322 discloses a paint remover composition containing methylene chloride, methanol and a quaternary nitrogen cellulose ether.
Other patents employing methylene chloride with alkanols and various other additives are U.S. Pat. Nos. 3,147,224; 3,075,923; 4,269,724 and 4,278,557.
A method of removing resist from printed circuit boards is described in U.S. Pat. No. 3,789,007 wherein the board is treated with a mixture of 85 to 97% by weight of methylene chloride with the balance being methanol.
Other methylene chloride-containing photoresist stripper compositions are disclosed in U.S. Pat. No. 3,625,763; 3,813,309 and 3,625,763.
SUMMARY OF THE INVENTION
The present invention is an improved photoresist stripper composition which contains methylene chloride, methanol and methyl formate. This combination strips the resist at a faster rate than prior art compositions. The preferred composition also provides a non-flashing mixture (blend) and gives better line definition than currently available commercial strippers.
DETAILED DESCRIPTION OF THE INVENTION
The improved methylene chloride formulation for use as a photoresist stripper contains methanol and methyl formate, each employed at a concentration of from about one to about ten percent by volume based on the total volume of the composition. The composition can optionally contain a stabilizer for the methylene chloride such as a vicinal epoxide, e.g. propylene oxide. Amines are frequently used as an aid in stripping, e.g. isopropylamine. Also useful are cyclohexylamine and triethylamine. Such amines are known to be contained in some current commercial stripper formulations.
Blends according to the invention were tested in the following ways:
Test 1--Drop Test
A fifty microliter drop of the test blend (1-25% additive(s) in methylene chloride) is placed on the crosslinked photoresist film contained on a printed circuit board. The solvent-film area is observed under a 150X microscope to determine the time (in seconds) necessary to fracture and lift the film from the board. Lower times are preferred in commercial operations.
This test was run with a number of possible additive candidates using commercially-prepared photoresist-covered printed circuit boards. These boards utilized crosslinked photoresist film.* Results from these tests are shown in Tables I and II. All of the additives were tested in an inhibited grade of methylene chloride to which was added 0.1 volume % isopropylamine.
TABLE I*______________________________________Additive** Drop Time (sec)(%) 5 7.5 10 15 25______________________________________Me Form. 8.3 8.8 10.1 11.3 10.2MeOH 10.3 10.0 9.6 10.4 11.5i-PrOH 11.7 12.5 12.8 14.1 16.7Me Acet. 13.1 13.2 13.5 15.9 20______________________________________
TABLE II*______________________________________Additive** Drop Time (sec)(%) 5 7.5 10 15______________________________________Me Form. 11.8 12.5 12.8 14.5Et Form 14.8 15.0 15.3 16.5MeOH 12.4 12.3 12.2 11.4i-PrOH 12.1 12.3 13.1 13.4Me Acet. 14.2 14.9 15.0 18.0THF 12.7 12.5 13.3 16.4______________________________________ *Table I shows results using a commercially available polymethylmethacrylate film and Table II a similar, but not identical film, manufactured by the same company. **MeOH = methyl alcohol iPrOH = isopropyl alcohol Me Form. = methyl formate Me Acet. = methyl acetate Et Form. = ethyl formate THF = tetrahydrofuran
Test 2--Spray Unit Test
A spray test was conducted utilizing a steel spray unit which was a laboratory scale version of the apparatus used in industry to strip resist film. Two-gallon quantities of test blends suggested from the preliminary screening were used in the spray unit. Solvent spray at 20 psig and 23°-24° C. was then directed onto the suspended boards for 10-15 seconds. The boards were weighed before and after stripping. Weight differences in amount of removed photoresist were compared with a standard* using the formula: ##EQU1## A positive % value indicated more complete stripping and a negative value less complete stripping when compared with the performance of the standard stripper blend.
The 4"×4" test boards were prepared by a commercial fabricator, using a commercially available photoresist resin** film and a test pattern consisting of numerous lines of varying widths and spacing. These boards, which were tin-lead plated, were ready for stripping as received.
Several compositions of methylene chloride containing different amounts of methanol and methyl formate were used in the above described spray test. A timed spray of 10-second duration was used. Methanol and methyl formate were each employed in amounts of 1.0, 2.5 and 4.0 volume percent in the methylene chloride (inhibited grade) based on the total volume of solvent and additives. Isopropylamine was present at 0.1 volume percent in each formulation total basis. Results of strippability of each formulation are shown as percent better (+) or worse (-) than a standard methylene chloride stripper in Table III.
TABLE III______________________________________ % MeOH 1.0 2.5 4.0______________________________________% Me Form. 1.0 -17.5 -10.7 +7.4 2.5 -1.6 +13.8 +13.2 4.0 +5.3 +4.4 +4.4______________________________________
Evaporation and corrosion tests were also performed on these compositions.
Two tests were done for evaporation. In the first, 300 ml test solution was prepared, placed in a beaker at room temperature in the hood, and analyzed at various times for additive composition using gas chromatography. Results are shown in Table IV. In the second test, two gallons of test solution were placed in the spray unit with the lid slightly opened. The unit was operated at 20 psig for a period of 60 minutes. Again, the concentrations of the additives were evaluated at various times. For this test at the end of one hour the concentration of methyl formate was about 2.85% and that of the methanol was about 2.30%, the initial concentrations being 3.0 volume percent each, which showed only slight loss of components from the mixture.
TABLE IV______________________________________*Composition (Vol. %)Time Volume(min.) MeOH Me Form. (ml)______________________________________0 3.00 3.00 30020 2.80 2.85 27560 2.55 2.80 21590 2.45 2.85 175120 2.00 2.75 140153 1.60 2.70 100______________________________________ *This composition also contained 0.1% isopropylamine by volume, but since its levels were unimportant with respect to strippability its analysis wa omitted.
A copper corrosion study consisted of refluxing 100 ml of test solvent blend with a 0.5×2.45 inch copper coupon for seven days. Triplicate determinations were run for each solvent blend. Gas chromatography analysis was done on each sample after the seven days. The corrosion rate of the copper coupon was expressed in mils penetration per year (MPY) using the following formula ##EQU2## Results for formulations of a commercial blend (A) and one according to the invention (B) under the conditions of the above test are shown below.
______________________________________Formulation (Vol. %) Corrosion (MPY)______________________________________A MeOH 7.5 1.01 IPA 0.1B MeOH 2.5 0.1 Me Form. 2.5 IPA 0.1______________________________________
The amine can present a slight problem of copper tarnishing and solvent discoloration if allowed to stand for a minimum of 12 hours at room temperature in the presence of the metal. This may not be a significant problem with respect to the boards, however, since the solvent contacts the copper circuit boards for only two to three minutes in actual commercial use. Since industrial equipment typically uses copper piping, however, this phenomenon can affect equipment life. It is interesting to note that use of a 0.1 volume percent triethylamine to replace isopropylamine in the B formulation greatly decreased the solvent discoloration problem in the room temperature copper corrosion tests. The amine adds nothing to the strippability characteristics of the formulation and if eliminated completely avoids the corrosion and discoloration of the copper.
The compositions according to the present invention are those containing from about 1 to about 10 volume percent each of methanol and methyl formate, with the proviso that the total of methanol and methyl formate be at least 5 and not more than about 10 volume percent of the total composition. The composition may also contain an amine. | An improved process for removing crosslinked photoresist polymer from printed circuit boards which comprises contacting the printed circuit board with methylene chloride containing from about 5 to about 10 volume percent of a mixture of methanol and methyl formate. Each additive must be present at a minimum concentration of one volume percent. Stabilizers for the methylene chloride, such as epoxides, may be present at amounts no greater than about 0.5 volume percent. | 2 |
CLAIM FOR PRIORITY
This non-provisional application claims the benefit of the filing date of U.S. Provisional Patent Application Ser. No. 60/366,790, of the same title, filed Mar. 22, 2002.
TECHNICAL FIELD
The present invention relates generally to disposable plates, bowls, platters and the like and more particularly to plastic articles of this class produced by thermoforming. The articles of the invention are thermoformed from extruded plastic sheet stock which is mineral-filled with a combination of mica and calcium carbonate.
BACKGROUND
Disposable food containers are well known in the art. Typically, such containers are made from paper or plastic.
Pressed paperboard containers may be made as noted in one or more of U.S. Pat. No. 4,606,496 entitled “Rigid Paperboard Container” of R. P. Marx et al; U.S. Pat. No. 4,609,140 entitled “Rigid Paperboard Container and Method and Apparatus for Producing Same” of G. J. Van Handel et al; U.S. Pat. No. 4,721,499 entitled “Method of Producing a Rigid Paperboard Container” of R. P. Marx et al; U.S. Pat. No. 4,721,500 entitled “Method of Forming a Rigid Paper-Board Container” of G. J. Van Handel et al; and U.S. Pat. No. 5,203,491 entitled “Bake-In Press-Formed Container” of R. P. Marx et al. Equipment and methods for making paperboard containers are also disclosed in U.S. Pat. No. 4,781,566 entitled “Apparatus and Related Method for Aligning Irregular Blanks Relative to a Die Half” of A. F. Rossi et al; U.S. Pat. No. 4,832,676 entitled “Method and Apparatus for Forming Paperboard Containers” of A. D. Johns et al; and U.S. Pat. No. 5,249,946 entitled “Plate Forming Die Set” of R. P. Marx et al.
Thermoformed plastic containers, particularly polypropylene mica-filled containers with a micronodular surface are disclosed in U.S. Pat. No. 6,100,512 to Neculescu et al. Such containers have the advantages that they are durable and may be washed and re-used if so desired and are microwaveable. The disclosure of the foregoing patents is incorporated by reference.
A drawback of plastic thermoformed containers is that they tend to be more costly than their paper counterparts due, in part, to material costs. More rigid materials can be used more sparingly and are thus highly desirable in the field. One way to increase rigidity of polypropylene containers is to use a filler such as mica as disclosed in the '512 patent. However, mica tends to interact with polypropylene to produce undesirable odors, believed to be caused by certain organic ketone compounds generated during melt-processing of the material. The generation of odors is minimized by including a basic inorganic compound, such as calcium carbonate in the composition.
It has been unexpectedly found that fine grades of calcium carbonate can greatly increase the rigidity of polypropylene containers filled with calcium carbonate and mica as described hereinafter.
SUMMARY OF INVENTION
Disposable polypropylene containers made from extruded polypropylene mica and calcium carbonate filled sheet exhibits enhanced rigidity when fine grades of calcium carbonate are used. An added advantage is that the sheet filled with finer calcium carbonate exhibits less die lip buildup as it is produced. For 11″ plates, normalized rigidity was observed to increase from 11 g/g to 12.8 g/g when the mean particle size of calcium carbonate used was changed from 12 to 6 microns. A further increase to 13.63 g/g of normalized rigidity was achieved when calcium carbonate with a mean particle size of 1 micron was used.
There is thus provided in accordance with the present invention a thermoformed disposable food container having a wall caliper of from about 10 to about 80 mils consisting essentially of from about 30 to about 80 percent by weight of a matrix polymer composition consisting predominantly of a polypropylene polymer and optionally including a polyethylene polymer, from about 10 to about 50 percent mica, from about 2.5 to about 25 percent calcium carbonate, and up to about 5 weight percent titanium dioxide, wherein the calcium carbonate has a mean particle size of less than about 8 microns. More preferably the calcium carbonate has a mean particle size of 6 microns or less; yet more preferably less than about 5 microns, and still more preferably the calcium carbonate has a mean particle size of less than about 3 or 2.5 microns. In some preferred embodiments, the calcium carbonate has a mean particle size of about 1 micron or less.
Particularly preferred embodiments include those wherein the mean particle size of the calcium carbonate is about 6 microns; those in which the mean particle size of the calcium carbonate is about 3 microns; and those wherein the mean particle size of the calcium carbonate is about 1 micron.
In other aspects of the invention, there are provided extrudable and injection moldable compositions having the same components in like proportions as the disposable food containers. These compositions may be in the form of pellets, for example, or extruded into sheet or film form or injection molded into useful articles. Here again, the compositions thus have a calcium carbonate content of from about 2.5 weight percent to about 25 weight percent calcium carbonate and so forth. Particularly preferred compositions include those wherein the calcium carbonate has a mean particle size of 6 microns; those wherein the calcium carbonate has a mean particle size of 3 microns; and those wherein the calcium carbonate has a mean particle size of about 1 micron.
Typically, the calcium carbonate is present in an amount of from about 5 to about 15 percent by weight of the container, whereas mica is present in an amount of from about 20 to about 40 percent by weight of the container. The matrix polymer composition generally consists of a polypropylene polymer and a polyethylene polymer in preferred cases. The polyethylene polymer may be present in an amount of from about 1 to about 15 percent by weight of the container, typically present in an amount of from 2.5 to about 7.5 percent by weight. A preferred polyethylene polymer is HDPE.
The polypropylene polymer is typically present in an amount of from about 40 to about 60 percent by weight of the container, and may be isotactic polypropylene. Optionally included is titanium dioxide typically in an amount of from about 0.5 to about 4 percent by weight of the container.
The containers may have a wall caliper of from about 10 to about 50 mils, typically from about 15 to about 25 mils.
These and other aspects of the invention will be further appreciated from the following description, drawings and claims.
BRIEF DESCRIPTION OF DRAWINGS
The invention is described in detail below with reference to the various drawings. In the drawings:
FIG. 1 is a view in perspective of a plate constructed in accordance with the present invention;
FIG. 2 is a view in cross-section and elevation of the plate of FIG. 1 illustrating the profile of the plate;
FIG. 3 is a schematic diagram illustrating the profile of the plate of FIGS. 1 and 2 .
FIG. 4 is a plot of SSI Rigidity versus product weight for 11″ mica-filled polypropylene plates containing 1 micron and 12 micron mean particle size calcium carbonate showing numerous runs; and
FIG. 5 is a plot of average SSI Rigidity versus average product weight for 11″ mica-filled polypropylene plates containing particles from different lots of 1 micron mean particle size calcium carbonate and 12 micron mean particle size calcium carbonate.
DETAILED DESCRIPTION
The invention is described in detail below with reference to the figures. Such description is for purposes of illustration only and is not limitative of the invention in any way.
Numerous modifications within the spirit and scope of the present invention, set forth in the appended claims, will be readily apparent to those of skill in the art.
Generally speaking, the present invention is directed to the discovery that using calcium carbonate having a mean particle size of less than 12 microns is beneficial when making polypropylene food containers from polypropylene sheet filled with mica and calcium carbonate. The smaller particle size calcium carbonate has a beneficial effect on container rigidity making it possible to use less material for a given container and also appears to reduce die lip build up during sheet extrusion. A composition with six (6) micron mean size calcium carbonate extruded into sheet extruded well with less die lip build up (about {fraction (5/16)}″ vs. about ⅜″) than a composition with twelve (12) micron mean particle size calcium carbonate. Still less die lip build up (about {fraction (3/16)}″) was observed when a calcium carbonate having a mean particle size of one (1) micron was used in corresponding compositions.
Containers formed from the sheet had the properties summarized in Table 1 below.
TABLE 1
General Observations
Properties of 11″ thermoformed plates made from sheet composed of:
Polypropylene
52%
Mica
30%
Calcium Carbonate
10%
HDPE
5%
TIO 2 + color
3%
Case 1
Case 2
Case 3
Product Weight
33.4
32.5
33.15
Calcium Carbonate
12
6
1
Particle Size (Microns)
GM SSI Rigidity
367
416
452
Normalized Rigidity g/g
11.0
12.8
13.63
As can be seen, product rigidity increases markedly as the particle size of the calcium carbonate is reduced. This discovery makes it possible to make a more rigid product with the same amount of material or maintain a target rigidity while reducing material consumption.
The foregoing is described and illustrated further below.
Test Methods, Definitions and Materials
SSI Rigidity is measured with the Single Service Institute Plate Rigidity Tester of the type originally available through Single Service Institute, 1025 Connecticut Ave., N.W., Washington, D.C. The SSI Rigidity test apparatus has been manufactured and sold through Sherwood Tool, Inc. Kensington, Conn. This test is designed to measure the rigidity (i.e., resistance to buckling and bending) of paper and plastic plates, bowls, dishes, and trays by measuring the force required to deflect the rim of these products a distance of 0.5 inch while the product is supported at its geometric center. Specifically, the plate specimen is restrained by an adjustable bar on one side and is center supported. The rim or flange side opposite to the restrained side is subjected to 0.5 inch deflection by means of a motorized cam assembly equipped with a load cell, and the force (grams) is recorded. The test simulates in many respects the performance of a container as it is held in the hand of a consumer, supporting the weight of the container's contents. SSI Rigidity is expressed as grams per 0.5 inch deflection. A higher SSI value is desirable since this indicates a more rigid product. All measurements were done at standard TAPPI conditions for paperboard testing, 72° F. and 50% relative humidity. Geometric mean averages for the machine direction (MD) and cross machine direction (CD) are reported herein.
The particular apparatus employed for SSI Rigidity measurements was a Model No. ML-4431-2 SSI Rigidity tester as modified by Georgia Pacific Corporation, National Quality Assurance Lab, Lehigh Valley Plant, Easton, Pa. 18040 using a Chatillon gauge available from Chatillon, Force Measurements Division, P.O. Box 35668, Greensboro, N.C. 27425-5668.
Unless otherwise specified, the following terms have the following meanings:
“Rigidity” refers to SSI Rigidity (kilograms or grams/0.5 inches).
“Sheet”, “sheet stock” and the like refers to both a web or roll of material and to material that is cut into sheet form for processing.
Particle size refers to mean particle size.
Mean particle size of a particulate material such as calcium carbonate is the particle diameter as to which 50 percent by weight of the particles of the particulate material have a smaller diameter. This quantity may be determined by any suitable technique.
Unless otherwise indicated, “mil”, “mils” and like terminology refers to thousandths of an inch and dimensions appear in inches. Likewise, caliper is the thickness of material and is expressed in mils unless otherwise specified.
The term major component, predominant component and the like refers to a component making up at least about 50% of a composition or that class of compound in the composition by weight as the context indicates; for example, a filler is the predominant filler in a filled plastic composition if it makes up more than about 50% by weight of the filler in the composition based on the combined weight of fillers in the composition, and a resin is the predominant resin in a composition if it makes up more than 50 percent of the resin in the composition.
Basis weights appear in lbs per 3000 square foot ream unless otherwise indicated.
Percents refer to weight percents.
Polypropylene polymers which are suitable are preferably selected from the group consisting of isotactic polypropylene, and copolymers of propylene and ethylene wherein the ethylene moiety is less than about 10% of the units making up the polymer, and mixtures thereof. Generally, such polymers have a melt flow index from about 0.3 to about 4, but most preferably the polymer is isotactic polypropylene with a melt-flow index of about 1.5.
A polyethylene polymer or component may be any suitable polyethylene such as HDPE, LDPE, MDPE, LLDPE or mixtures thereof and may be melt-blended with polypropylene if so desired. The various polyethylene polymers referred to herein are described at length in the Encyclopedia of polymer Science & Engineering (2d Ed.), Vol. 6; pp: 383-522, Wiley 1986; the disclosure of which is incorporated herein by reference. HDPE refers to high density polyethylene which is substantially linear and has a density of generally greater that 0.94 up to about 0.97 g/cc. LDPE refers to low density polyethylene which is characterized by relatively long chain branching and a density of about 0.912 to about 0.925 g/cc. LLDPE or linear low density polyethylene is characterized by short chain branching and a density of from about 0.92 to about 0.94 g/cc. Finally, intermediate density polyethylene (MDPE) is characterized by relatively low branching and a density of from about 0.925 to about 0.94 g/cc.
“Thermoforming”, “thermoformed” and like terminology is given its ordinary meaning. In the simplest form, thermoforming is the draping of a softened sheet over a shaped mold. In the more advanced form, thermoforming is the automatic high speed positioning of a sheet having an accurately controlled temperature into a pneumatically actuated forming station whereby the article's shape is defined by the mold, followed by trimming and regrind collection as is well known in the art. Still other alternative arrangements include the use of drape, vacuum, pressure, free blowing, matched die, billow drape, vacuum snap-back, billow vacuum, plug assist vacuum, reverse draw with plug assist, pressure bubble immersion, trapped sheet, slip, diaphragm, twin-sheet cut sheet, twin-sheet roll-fed forming or any suitable combinations of the above. Details are provided in J. L. Throne's book, Thermoforming , published in 1987 by Coulthard. Pages 21 through 29 of that book are incorporated herein by reference. Suitable alternate arrangements also include a pillow forming technique which creates a positive air pressure between two heat softened sheets to inflate them against a clamped male/female mold system to produce a hollow product. Metal molds are etched with patterns ranging from fine to coarse in order to simulate a natural or grain like texturized look. Suitable formed articles are trimmed in line with a cutting die and regrind is optionally reused since the material is thermoplastic in nature. Other arrangements for productivity enhancements include the simultaneous forming of multiple articles with multiple dies in order to maximize throughput and minimize scrap. In some preferred embodiments, the melt-compounded composition from which the articles are made may include polypropylene and optionally further includes a polyethylene component and titanium dioxide. Suitable materials and techniques for fabricating the disposable containers of the present invention from thermoplastic materials appear in U.S. Pat. No. 6,211,501 to McCarthy et al. as well as U.S. Pat. No. 6,211,500 to Cochran II et al. the disclosures of which are incorporated herein by reference.
Preferred Embodiments
In general, products of the invention are made by first extruding a polypropylene sheet of suitable composition as described in the '500 and '501 patents followed by thermoforming the sheet as is also described in the '500 and '501 patents. A suitable container shape is that described in U.S. Co-Pending application Ser. No. 09/603,579, filed Jun. 26, 2000, entitled “Smooth Profiled Food Service Articles”. These plates have the characteristics seen in FIGS. 1-3 below and in Tables 2-4.
Illustrated in FIGS. 1 through 3 , there is a plate 10 which includes a planar center 12 which, in turn, includes an outer peripheral surface 14 . This center region 12 may have a slight convex crown to improve plate stability during use. The planar center 12 forms a bottom for the plate 10 . An outwardly projecting sidewall 16 includes a first rim portion 18 which is joined to the outer peripheral surface 14 of the planar center 12 . A second rim portion 20 is joined to the first rim portion 18 . The first rim portion 18 and the second rim portion 20 form the outwardly projecting sidewall 16 which forms the sidewall of the plate 10 . A rim 22 includes a third rim portion 24 which is joined to the second rim portion 20 of the outwardly projecting sidewall 16 . A fourth rim portion 26 is joined to the third rim portion 24 . The fourth rim portion 26 forms the outer edge of the plate 10 .
FIG. 3 illustrates a partial cross-sectional view of a plate, diameter D, according to the present invention. The plate 10 defines a center line 34 . A base or bottom-forming portion 30 extends from the center line 34 to an outer peripheral portion 32 .
From the center line 34 a predetermined distance X 12 extends toward the outer peripheral surface forming portion 32 . A distance Y 12 extends a predetermined distance from the base or bottom-forming portion 30 upwardly therefrom. A radius R 12 extends from the intersection point of the distance X 12 and Y 12 to form a first rim portion 36 of the outwardly projecting sidewall 35 . The first rim portion 36 is defined by an arc A 12 which extends from a substantially vertical line defined at an outer peripheral point 37 to a fixed point 40 . The arc A 12 may be approximately 60°.
A distance X 22 extends from the center line 34 to a predetermined point. A distance Y 22 extends from the base or bottom-forming portion 30 of the plate 10 downwardly a predetermined distance. A radius R 22 extends from the intersection of the lines X 22 and Y 22 to define the radius of curvature of a second rim portion 38 of the sidewall 35 . The radius R 22 extends from the first fixed point 40 to the second fixed point 42 through an arc A 22 . The arc A 22 may be approximately 4°.
A distance X 32 extends from the center line 34 to a predetermined distance. A distance Y 32 extends from the base or bottom-forming section 30 of the plate 10 to project upwardly a predetermined distance. A radius R 32 extends from the intersection of the lines X 32 and Y 32 which is the radius of the third rim portion 44 of the rim 46 . The radius R 32 extends from the second fixed point 42 to a third fixed point 48 . An arc A 32 is formed between the second fixed point 44 and the third fixed point 48 to extend a predetermined distance. The arc A 32 may be approximately 55°.
A distance X 42 extends a predetermined distance from the center line 34 . Similarly, a distance Y 42 extends from the base or bottom-forming section 30 of the plate 10 to project upwardly. A radius R 42 extends from the intersection of the lines X 42 and Y 42 to define the radius of curvature of a fourth rim portion 47 of the rim 46 . An arc A 42 is formed between the third fixed point 48 and a fourth fixed point 50 at diameter D from the center line. The arc A 42 may be approximately 60°. A section disposed at 50 forms the outer edge of the plate.
The article made according to the present invention may have any particular size or shape. In various embodiments of the present invention the container may be a 9″ or 11″ plate with profile coordinates as illustrated in FIGS. 1 through 3 having the dimensions, angles, or relative dimensions enumerated in Tables 2 through 4.
TABLE 2
Dimensions and Angles For 9″ Plate
DIMENSION and ANGLES
VALUE (inches or degrees)
R12
0.537
X12
3.156
Y12
0.537
R22
2.057
X22
5.402
Y22
0.760
R32
0.564
X32
4.167
Y32
0.079
R42
0.385
X42
4.167
Y42
0.258
A12
60.00°
A22
4.19°
A32
55.81°
A42
60.00°
D
9.00
BOTTOM CONVEX CROWN
0.06
TABLE 3
Dimensions and Angles For 11′ PLATE
DIMENSION/ANGLES
VALUE (inches or degrees)
R12
0.656
X12
3.857
Y12
0.656
R22
2.514
X22
6.602
Y22
0.929
R32
0.689
X32
5.093
Y32
0.097
R42
0.470
X42
5.093
Y42
0.315
A12
60.00°
A22
4.19°
A32
55.81°
A42
60.00°
D
11.00
BOTTOM CONVEX CROWN
0.06
TABLE 4
Dimensions For 9″ and 11″ PLATES
DIMENSION
RATIO OR
VALUES (Dimensionless or degrees)
ANGLE
PREFERRED
MINIMUM
MAXIMUM
R12/D
0.060
0.045
0.075
X12/D
0.351
0.280
0.420
Y12/D
0.060
0.045
0.075
R22/D
0.228
0.180
0.275
X22/D
0.600
0.480
0.720
Y22/D
0.084
0.065
0.100
R32/D
0.063
0.050
0.075
X32/D
0.463
0.370
0.555
Y32/D
0.009
0.007
0.011
R42/D
0.043
0.034
0.052
X42/D
0.463
0.370
0.555
Y42/D
0.029
0.023
0.035
A12
60.00°
55.00°
75.00°
A22
4.19°
1.00°
10.00°
A32
55.81°
45.00°
75.00°
A42
60.00°
45.00°
75.00°
Salient features of the plate illustrated in FIGS. 1 through 3 generally include a substantially planar center portion (which may be crowned as noted above and illustrated throughout the various figures) with four adjacent rim portions extending outwardly therefrom, each rim portion defining a radius of curvature as set forth above and further noted below. The first rim portion extends outwardly from the planar center portion and is convex upwardly as shown. There is defined by the plate a first arc A 12 with a first radius of curvature R 12 wherein the arc has a length S 1 . A second rim portion is joined to the first rim portion and is downwardly convex, defining a second arc A 22 , with a radius of curvature R 22 and a length S 2 . A third, downwardly convex, rim portion is joined to the second rim portion and defines another arc A 32 . There is defined a third radius of curvature R 32 and a third arc length S 3 . A tangent to the third arc at the upper portion thereof is substantially parallel to the planer center portion as shown in FIG. 2. A fourth rim portion is joined to the third rim portion, which is also downwardly convex. The fourth rim portion defines a fourth arc A 42 with a length S 4 , with a radius of curvature R 42 .
The length of the second arc, S 2 is generally less the length of the fourth arc S 4 , which, in turn, is less than the length S 1 of the first arc A 12 . The radius of curvature R 42 of the fourth arc is less than the radius of curvature R 32 of the third rim portion, which in turn, is less than radius of curvature R 22 of the second rim portion. The angle of the first arc, A 12 is generally greater that about 55 degrees, while, the angle of the third arc, A 32 is generally greater than about 45 degrees as is set forth in the foregoing tables. The angle of the fourth arc A 42 is generally less than about 75 degrees and more preferably is about 60 degrees.
Typically, the length S 1 of arc A 12 is equivalent to the length S 3 of arc A 32 and R 12 of the first rim portion is equivalent in length to the radius of curvature R 32 of the third rim portion.
Generally speaking, the height of the center of curvature of the first arc (that is the origin of ray R 12 ) above the central planar portion is substantially less than, perhaps twenty five percent or so less than, the distance that the center of curvature of the second rim portion (the origin of ray R 22 ) is below the central planar portion. In other words, the length Y 12 is about 0.75 times or less the length Y 22 .
So also, the horizontal displacement of the center of curvature of the second rim portion from the center of curvature of the first rim portion is at least about twice the length of the first radius of curvature R 12 . The height of the center of curvature of the third rim portion above the central planar portion is generally less than the height of the center of curvature of the fourth rim portion above the plane of the central planar portion. The horizontal displacement of the center of curvature of the second rim portion is generally outwardly disposed from the center of curvature of the third and fourth rim portions. A further noteworthy feature of the plate of FIGS. 1 through 3 is that the height of the center of curvature of the third rim portion above the planar central portion is less than about 0.3 times the radius of curvature R 42 of the fourth rim portion; while the height of the center of curvature of the fourth rim portion above the plane of the central portion is at least about 0.4 times the first radius of curvature R 12 .
Specific Examples
A series of 11″ plates described generally above were thermoformed from extruded sheet having the following composition:
Component Wt. Percent Polypropylene 52 Mica 30 Calcium Carbonate 10 HDPE 5 TiO 2 + color 3
Basis weights of sheet material used were from 255 to 315 lbs/3000 square foot ream and 3 different types of particulate calcium carbonate were used: 12 micron mean particle size material, 1 micron mean particle size material (Lot A) and another 1 micron mean particle size material (Lot B). The one micron material is available from Imerys as supermite calcium carbonate. Six micron material, available from Omya, called Omya 5, has an average particle size of about 6 microns and may likewise be employed. The mica may have a mean particle size of 50 microns or so.
Results are summarized in Table 5 below and appear graphically in FIGS. 4 and 5 which are plots of SSI Rigidity versus product weights, that is, the weight of the plate. As can be seen, products made with the 1 micron calcium carbonate exhibited consistently higher rigidity levels at all weights, whereas products with the Lot A 1 micron mean size material exhibited a remarkable increase in rigidity at all weights tested.
TABLE 5
SSI Rigidity for 11″ Thermoformed Mica/Calcium Carbonate-Filled
Polypropylene Plates
Average
Nominal
Mean CaCO 3
Product
Average SSI
Example
Basis
Particle Size
Weight
GM Rigidity
Series
Weight (lbs)
(Microns)/Lot
(grams)
(grams)
A
315
12
33.4
367
1
315
1/A
33.15
452
2
315
1/B
33.7
409
B
295
12
31.5
330
3
295
1/B
31
337
C
275
12
28.9
270
4
275
1/B
28.6
286
D
255
12
27.1
237
5
255
1/A
26.6
280
The invention has been described in detail hereinabove in connection with numerous embodiments. That discussion is not intended to limit in any way the scope of the present invention which is defined in the appended claims. It will be readily appreciated by one of skill in the art that the particular embodiments illustrated may be scaled up or down in size with the relative proportions shown herein or that product shapes such as square or rectangular with rounded corners, triangular, multi-sided, oval platters, polygonal platters with rounded corners and the like may be formed in accordance with the present invention. Typical products include plates, bowls, trays, deep dish containers, platters and so forth. | A thermoformed disposable food container having a wall caliper of from about 10 to about 80 mils consisting essentially of from about 30 to about 80 percent by weight of a matrix polymer composition consisting predominantly of a polypropylene polymer and optionally including a polyethylene polymer, from about 10 to about 50 percent mica, from about 2.5 to about 25 percent calcium carbonate, and up to about 5 weight percent titanium dioxide, exhibits enhanced rigidity when the calcium carbonate has a mean particle size of less than about 8 microns. The extrudable compositions are likewise useful for film, sheet and injection molding applications. | 8 |
[0001] This application claims priority from provisional application Ser. No. 61/175,815, filed May 6, 2009, the entire contents of which are incorporated herein by reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure relates generally to a surgical instrument and, more specifically, to a surgical instrument for clamping, severing, and joining tissue.
[0004] 2. Background of Related Art
[0005] Certain surgical stapling instruments are used for applying rows of staples through compressed living tissue. These surgical stapling instruments are employed, for example, for fastening tissue or organs prior to transection or resection or during anastomoses. In some cases, these surgical stapling instruments are utilized for occluding organs in thoracic and abdominal procedures.
[0006] Typically, such surgical stapling instruments include an anvil assembly, a cartridge assembly for supporting an array of surgical staples, an approximation mechanism for approximating the cartridge and anvil assemblies, an alignment or guide pin assembly for capturing tissue between the cartridge and anvil assemblies and for maintaining alignment between the cartridge and anvil assemblies during approximation and firing, and a firing mechanism for ejecting the surgical staples from the cartridge assembly.
[0007] In use, the alignment pin assembly is advanced and the anvil and cartridge assemblies are approximated. Next, the surgeon fires the instrument to place staples in tissue. Optionally, the surgeon may use the same instrument or a separate device to cut the tissue adjacent or between the row(s) of staples. The alignment pin in some instances is advanced automatically with approximation of the cartridge; in other instances it is advanced by a separate mechanism.
SUMMARY
[0008] The present disclosure provides a surgical instrument comprising a handle portion, an elongated portion defining a longitudinal axis and extending distally from the handle portion, and an end effector disposed adjacent a distal portion of the elongated portion including a first jaw member and a second jaw member dimensioned to clamp tissue therebetween.
[0009] A pin is disposed in mechanical cooperation with the first jaw member and includes an engagement section and is movable between a first position wherein the engagement section is spaced from the second jaw member and a second position wherein the engagement section engages the second jaw member. The pin has a non-circular cross-section.
[0010] Preferably, a knife is provided to move distally to cut the clamped tissue. Preferably, the knife has an upper edge terminating alongside the pin. In one embodiment, the pin has a gap dimensioned to accommodate the knife. The instrument can include rows of fasteners with the knife positioned between the rows.
[0011] In one embodiment, the pin is substantially semi-circular in cross-section. In another embodiment the pin is substantially L-shaped in cross-section.
[0012] The instrument can include a second non-circular pin. In one embodiment, the pins are spaced from each other and one pin is adjacent a top portion of a knife and the other pin is positioned adjacent a bottom portion of the knife. The pins can be positioned on opposite sides of a knife slot from which the knife extends.
[0013] In some embodiments, the instrument can further include a second pin having a substantially semi-circular cross section, each of the pins having a substantially planar surface, the substantially planar surface of the second pin facing a direction opposite the direction the substantially planar surface the other pin faces.
[0014] The pins in some embodiments can move in a distal direction automatically when the first and second jaw members move to a position to clamp tissue.
[0015] In another aspect, a surgical instrument is provided comprising a handle portion, an elongated portion defining a longitudinal axis and extending distally from the handle portion, and an end effector disposed adjacent a distal portion of the elongated portion. The end effector included a first jaw member and a second jaw member, the first and second jaw members dimensioned to clamp tissue therebetween. The first jaw member has at least one row of fasteners arranged in a row substantially transverse to the longitudinal axis. A pin is disposed in mechanical cooperation with the first jaw member and includes an engagement section, the pin movable between a first position wherein the engagement section is spaced from the second jaw member and a second position wherein the engagement section engages the second jaw member. A second pin is spaced from the first pin, the first pin and second pin each having a surface alongside the knife wherein the first surface of the first pin faces in a first direction and the second surface of the second pin faces in a second opposite direction.
[0016] In some embodiments, the first and second surfaces of the pins are substantially planar. The first pin can have a third surface facing toward a top surface of the knife and the second pin can have a fourth surface facing towards the bottom surface of the knife. In some embodiments, the pins move in a distal direction automatically when the first and second jaw members move to a position to clamp tissue.
BRIEF DESCRIPTION OF DRAWINGS
[0017] Various embodiments of the presently disclosed surgical stapling instrument are disclosed herein with reference to the drawings, wherein:
[0018] FIG. 1 is a perspective view of a surgical stapling instrument of the present disclosure;
[0019] FIG. 1A is a perspective view of an end effector of the instrument of FIG. 1 ;
[0020] FIG. 1B is a side cross-sectional view of the end effector of the instrument of FIG. 1 with the jaw members in the open position;
[0021] FIG. 1C is a side cross-sectional view of the end effector of FIG. 1 with the jaw members in the closed position;
[0022] FIG. 2 is a close up perspective view of one embodiment of the cartridge assembly having a pin with a semi-circular cross-section;
[0023] FIG. 3 is a perspective view of the area of detail designated in FIG. 2 ;
[0024] FIG. 4 a close up perspective view of another embodiment of the cartridge assembly having four rows of staples;
[0025] FIG. 5 is a close up perspective view of another embodiment of the cartridge assembly;
[0026] FIG. 6 is a close up perspective view of the area of detail designated in FIG. 5 ; and
[0027] FIG. 7 is a close up perspective view of another embodiment of the cartridge assembly having two pins with a semi-circular cross-section.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0028] Embodiments of the presently disclosed surgical stapling instrument are described in detail with reference to the drawings, wherein like reference numerals designate corresponding elements in each of the several views. In the description that follows, the term “proximal” refers to the end or portion of the surgical stapling instrument closer to the user, whereas the term “distal” refers to the end or portion of the surgical stapling instrument further from the user.
[0029] In the interest of brevity, the present disclosure focuses on the pin for a surgical stapling instrument designated in the drawings by reference numeral 100 . U.S. Pat. No. 7,407,076, the entire contents of which are incorporated by reference herein, describes in detail the structure and operation of an embodiment of surgical stapling instrument 100 .
[0030] FIG. 1 illustrates a surgical stapling instrument 100 designed for applying fasteners and cutting tissue. In brief, surgical stapling instrument 100 includes a handle portion 110 , an elongate portion 120 , and an end effector 130 extending from the distal portion of the elongate portion 120 . Handle portion 110 contains a trigger 140 for actuating end effector 130 . Elongate portion 120 extends distally from handle portion 110 and defines a longitudinal axis A-A therealong. End effector 130 is disposed adjacent to a distal portion of elongate portion 120 and includes a first jaw member or cartridge assembly 150 and a second jaw member or anvil assembly 160 . In this embodiment, cartridge assembly 150 is adapted to move longitudinally with respect to anvil assembly 160 upon actuation of trigger 140 to clamp tissue between the jaw members 150 , 160 . It is also contemplated that the anvil assembly can be moved (approximated) toward the cartridge assembly or that the cartridge and anvil assemblies can both be moved toward each other to clamp tissue.
[0031] Cartridge assembly 150 includes a plurality of slots 152 ( FIGS. 1B and 1C ) each capable of holding a staple or any other suitable fastener. Each slot 152 is operatively associated with a pusher thrust bar or plunger 122 . Pusher 122 extends along elongate portion 120 and partially into cartridge assembly 150 . Cartridge assembly 150 also includes a knife advanceable to cut tissue clamped between the cartridge and anvil assemblies 150 , 160 , respectively. In use, pusher 122 moves distally upon actuation of trigger 140 and causes the ejection of the staples disposed in slots 152 in a distal direction, substantially parallel to the longitudinal axis of the elongate portion 120 . In addition to slots 152 , cartridge assembly 150 includes a pin 154 operatively connected to pusher 122 and a bore 156 dimensioned to slidably receive pin 154 . Pin 154 is adapted to move longitudinally along bore 156 in response to a translation of pusher 122 . The pin 154 can alternatively be moved by a sliding knob 155 in the handle portion 110 . In the embodiment depicted in FIG. 1A-1C , anvil assembly 160 has a hole 162 designed to receive at least a portion of pin 154 . Anvil assembly 160 has staple-deforming pockets 164 for deforming the fasteners ejected from cartridge assembly 150 . An elongated slot can be provided between the pockets 164 in the anvil assembly to accommodate the knife described below.
[0032] While anvil assembly 160 remains stationary with respect to cartridge assembly 150 during operation, cartridge assembly 150 is movable longitudinally between a proximal position and a distal position upon actuation of trigger 140 . In the proximal position, cartridge assembly 150 is spaced apart from anvil assembly 160 , as seen in FIG. 1B in an approximated position. The actuation of trigger 140 causes clamp slides 170 , operatively connected thereto, to move distally which in turn causes thrust bar 122 to move distally due to pins 174 . In turn, the distal translation of thrust bar 122 causes the distal movement of cartridge assembly 150 toward anvil assembly 160 to an approximated position. While cartridge assembly 150 moves from the proximal position toward the distal position, end effector 130 clamps any tissue “T” placed between cartridge assembly 150 and anvil assembly 160 as shown in FIG. 1C . In the distal position, cartridge assembly 150 is located closer to anvil assembly 160 and presses tissue “T” against anvil assembly 160 .
[0033] Further actuation of trigger 140 , i.e. a second squeeze of the trigger 140 , once cartridge assembly 150 reaches its distal (approximated) position causes ejection of the fasteners from slots 152 . That is, the continued distal translation of pusher 122 , once cartridge assembly 150 is located in the distal position, causes the deployment of the fasteners positioned in slots 152 . During deployment, these fasteners exit slots 152 and advance through tissue and into contact with staple-deforming pockets 164 of anvil assembly 160 for formation thereof, e.g. bending of the staple legs into a “B” configuration. Actuation of trigger 140 also advances the knife to sever tissue clamped between the cartridge and anvil jaw assemblies 150 , 160 .
[0034] Note the distal motion of clamp slides 170 causes alignment pin 154 to move distally along bore 156 due to the operative connection of the alignment pin pusher 172 to the clamp slides 170 via pins extending through elongated slots in pin pusher 172 as described in U.S. Pat. No. 7,407,076. (Pin pusher 172 includes a vertical portion having an abutment member configured to engage the proximal end of the pin 154 .) Upon sufficient distal movement of pin 154 , hole 162 of anvil assembly 160 receives a portion of pin 154 . The structural interaction between pin 154 and hole 162 (when cartridge assembly 150 is located in the distal position) assists in the alignment of slots 152 with staple-deforming pockets 164 . It should be appreciated that alignment pin 154 can alternatively be moved manually as pin pusher 172 is moved manually, e.g. by sliding knob 155 .
[0035] Turning now to embodiments of the alignment pins of the present disclosure illustrated in FIGS. 2-7 , these pins can be used with the stapler of FIG. 1 described above or with other suitable surgical staplers. They can be configured to move automatically with approximation of the cartridge, i.e. in response to actuation of the trigger, and/or moved by the user separate from approximation, e.g. by an independent slidable knob or other manual controls or knobs located at various portions of the instrument. Thus, it should be understood that it is contemplated that the pins disclosed herein can be moved in either way (automatic or manual) or in both ways.
[0036] FIGS. 2 and 3 illustrate a close up view of the cartridge assembly 150 of FIG. 1 . In this embodiment, cartridge assembly 150 includes a plurality of staple slots 132 and a knife slot 134 . Each staple slot 132 houses a staple or fastener 136 . Knife slot 134 is adapted to receive knife 138 . Knife 138 is configured to move longitudinally to cut tissue between the staple rows. Preferably, knife 138 is advanced distally when the staples are advanced from cartridge assembly 150 through tissue. In this embodiment, two rows of staples are provided, extending substantially linearly and substantially transverse to longitudinal axis A-A of the instrument 100 . A different number of staples and staple rows are also contemplated.
[0037] Cartridge assembly 150 further includes a bore 156 configured to receive a pin 154 . Pin 154 is adapted to move longitudinally between a proximal position and a distal position and has a substantially semi-circular cross-section to allow passage of knife 138 adjacent the pin 154 . That is, the knife 138 passes by (alongside) the substantially planar inner surface region of the pin 154 . The substantially semi-circular shape of pin 154 allows the knife 138 to extend up to the region of the pin 154 . As shown, the knife 134 extends past the bottom 154 a of the pin 154 and terminates adjacent an intermediate region 154 b of the pin 154 . Other knife heights are also contemplated. The staple slots 156 and staple line extend beyond the top edge 138 a of the knife 138 and beyond the bottom edge 138 b of the knife 138 .
[0038] FIG. 4 illustrates an alternate embodiment of the cartridge assembly, designated generally by reference numeral 250 . Cartridge assembly is substantially identical to cartridge assembly 150 of FIG. 2 , except that four rows of staples are provided. As shown, the four substantially linear rows of staples 236 are arranged substantially transverse to the longitudinal axis A-A of the instrument, with two staggered rows positioned on either side of knife 238 . As in the other embodiments herein, the staples 236 are fired in a direction substantially parallel to the longitudinal axis of the instrument. The knife 238 is movable from knife slot 234 to sever tissue clamped between the cartridge and anvil assemblies. Pin 254 is substantially semi-circular shaped, similar to pin 154 . The staples 236 extend beyond the upper and lower edges 238 a , 238 b , respectively, of knife 238 .
[0039] In the alternate embodiment of FIG. 5 , cartridge assembly, designated generally by reference numeral 350 , is substantially identical to cartridge assembly 150 of FIG. 2 , except for the configuration of pin 354 . As shown, two substantially linear rows of staples 236 are arranged substantially transverse to the longitudinal axis of the instrument, with one row positioned on either side of knife 338 . A different number of rows are also contemplated. The knife 338 is movable from knife slot 334 to sever tissue clamped between the cartridge and anvil assemblies. The staples 336 extend beyond the upper and lower edges 338 a , 338 b , respectively, of knife 338 . Pin 354 is substantially L-shaped in configuration to create a gap 357 to accommodate the knife. That is, portion 354 a extends downwardly alongside the knife 338 and portion 354 b extends transversely above the upper edge 338 a of knife 338 . Consequently, the pin 354 extends in an arc of about 270 degrees (although other arcs are also contemplated).
[0040] It should be appreciated that although one alignment pin is shown, it is also contemplated that two alignment pins can be provided, e.g. one on the upper portion of the cartridge and the other on the lower portion of the cartridge. This is shown for example in the embodiment of FIG. 7 , wherein upper pin 454 and lower pin 455 are provided in cartridge 450 . Each of the pins 454 , 455 are substantially semi-circular in configuration, similar to pin 254 of FIG. 2 , however the substantially L-shaped pins of FIG. 5 could also be provided (either one at the top or bottom utilized with the substantially semi-circular pin on the opposing end or on both the top and bottom.) Note that the pins 454 , 455 are preferably on opposing sides of the knife 438 . As in the other embodiments, the staple line extends beyond the upper edge 438 a and lower edge 438 b of knife 438 .
[0041] While the above description contains many specifics, these specifics should not be construed as limitations on the scope of the present disclosure, but merely as illustrations of various embodiments thereof. Therefore, the above description should not be construed as limiting, but merely as exemplifications of various embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto. | A surgical instrument comprising a handle portion, an elongated portion defining a longitudinal axis and extending distally from the handle portion, and first and second jaw members dimensioned to clamp tissue therebetween. The first jaw member has at least one row of fasteners arranged in a row substantially transverse to the longitudinal axis. A pin is disposed in mechanical cooperation with the first jaw member and is movable between a first position where the engagement section is spaced from the second jaw member and a second position where the engagement section engages the second jaw member. The pin has a non-circular cross-section. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a 371 National Stage Application of PCT/EP2014/064587, filed Jul. 8, 2014. This application claims the benefit of European Application No. 13176501.8, filed Jul. 15, 2013, which is incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a system and a method for data processing, in particular for sensor data processing, as defined below.
[0004] 2. Description of the Related Art
[0005] In prior art data processing systems, data captured by a plurality of different data capturing modules, e.g. optical, acoustic or temperature sensors, are forwarded to a central processing module, e.g. a sensor data evaluation module, in which the forwarded data are processed. Usually, captured sensor data are forwarded to the sensor data evaluation module by each sensor automatically, for example upon generation of sensor data dependent from electromagnetic or acoustic waves emerging from an object under investigation and received by the sensor. By this, however, it cannot always be ensured that all relevant sensor data captured or generated by several different kinds of sensors are forwarded and processed in the sensor data evaluation module.
SUMMARY OF THE INVENTION
[0006] Preferred embodiments of the invention provide a system and a method for data processing, in particular sensor data processing, which ensures that relevant data captured by a plurality of different data capturing modules are made available in the processing module in a fast and reliable manner.
[0007] The preferred embodiments are achieved by the system and method defined below.
[0008] The system for data processing according to a preferred embodiment of the invention comprises at least two first modules, each of said first modules being adapted for generating or capturing first data, at least one second module, adapted for retrieving first data from those first modules which correspond to first modules of at least one pre-defined set of first modules, and a third module, adapted for processing the first data which were retrieved by the at least one second module.
[0009] In the method for data processing according to a preferred embodiment of the invention at least two first modules generate or capture first data, at least one second module retrieves first data from those first modules which correspond to first modules of at least one pre-defined set of first modules, and a third module processes the first data which were retrieved by the at least one second module.
[0010] Preferred embodiments of the invention are based on the approach to provide a second module, which is configurable and/or customizable to the effect that at least one set of first modules can be pre-defined, preferably by a user. Moreover, the second module is adapted for calling only those first modules corresponding to the at least one pre-defined set of first modules, for receiving first data from the called first modules and for forwarding the received data to the third module in which the received data are processed. As a result, all first data captured by a desired, i.e. pre-defined, set of first modules are available for processing in the third module, irrespective of the different moments in time in which the first data have been generated or captured by respective first modules of the pre-defined set of first modules.
[0011] In summary, preferred embodiments of the invention ensure that all desired and/or relevant data captured by different data capturing modules are present in the processing module. Within the meaning of the present invention the term “module” preferably relates to an electronic device and/or a software entity which is configured to execute specified functions.
[0012] For example, the term “first module” preferably relates to a device and/or an electronic circuit and/or a software entity which is configured to generate and/or capture data. E.g., the first module can be or can comprise a medical device, a sensor or an input unit, like a barcode scanner and/or a keyboard, enabling data input.
[0013] The term “second module” preferably relates to a device and/or an electronic circuit and/or a software entity which is configured to retrieve data and/or obtain data and/or forward data. Further, the second module is preferably configurable by a user such that the second module retrieves and/or obtains and/or forwards only data of a pre-defined data set, which has been pre-defined by a user.
[0014] Preferably, the term “third module” relates to a device and/or an electronic circuit and/or a software entity which is configured to process data, e.g. by calculating values based on retrieved or obtained data (e.g. by summation, multiplication, division etc.) and/or compiling retrieved or obtained data and/or generating a document based on retrieved or obtained data or on calculated values based on retrieved or obtained data.
[0015] Within the meaning of the present invention, the term “pre-defined set of first modules” preferably relates to two or more first modules constituting a set of first modules, wherein the two or more first modules of the set of first modules are pre-definable by an according user input into the second module.
[0016] Preferably, the second module is configured to call only those first modules that constitute the at least one pre-defined set of first modules and/or to receive or obtain first data from the called first modules and/or to forward the received or obtained data to the third module in which the received or obtained data are processed.
[0017] According to a preferred embodiment of the invention, the at least one second module being adapted for forwarding the retrieved first data to the third module such that the retrieved first data are available in the third module at a certain, in particular pre-defined, point of time. Preferably, said certain or pre-defined point of time corresponds to the point of time at which the processing of the retrieved first data commences. By this, it is ensured that all of the desired first data can be considered in the subsequent processing step. This is of particular advantage in cases where the third module is adapted for calculating at least one second data from at least two of the retrieved first data. Because it is ensured that all of the desired first data are available at the beginning of the calculation procedure, the second data calculated from the retrieved first data, e.g. by summation, subtraction, multiplication or division, corresponds to the correct value.
[0018] It is also preferred that the third module is adapted for requesting the second module to forward the retrieved first data to the third module. Preferably, the third module sends a request to the second module shortly before a processing of the retrieved first data shall start and/or upon a user request to the third module to start with a processing of first data.
[0019] Further it is particularly preferred that, first, the third module sends a request to the second module to forward first data to the third module, second, upon receipt of the request from the third module the second module sends a request to the pre-specified first modules to forward first data captured by the pre-specified first modules to the second module and, third, the second module forwards the first data retrieved from the pre-specified first modules to the third module.
[0020] The aforementioned embodiments—alone or in combination—further contribute to ensure that all of the desired first data of the pre-specified first modules are available at the third module in order to be altogether and/or commonly processed. By this, e.g. all sensor data captured by one or more pre-specified optical sensors and acoustic sensors can be considered in the processing step at the same time.
[0021] According to another preferred embodiment of the invention, the at least one second module being adapted for selecting at least one pre-defined set of first modules from multiple pre-defined sets of first modules and for retrieving first data from those first modules which correspond to first modules of the at least one selected pre-defined set of first modules. The multiple pre-defined sets of first modules can be established or defined, e.g. by a user when applying the system or method in continuous or daily use or when setting up the system or method for the first time, e.g. in the manufacturing process. By establishing or defining multiple pre-defined sets of first modules, from which at least one set of first modules can be chosen, the system and method according to preferred embodiments of the invention can be easily adapted to various applications in which first data from different first modules are to be processed in the third module.
[0022] Basically, the system and method can be configured such that the at least one pre-defined set of first modules can be manually, e.g. by a user, selected from multiple pre-defined sets of first modules.
[0023] Alternatively or additionally, it is preferred that the third module is adapted for processing the retrieved first data dependent upon a given processing mode and that the at least one second module being adapted for automatically selecting at least one pre-defined set of first modules from multiple pre-defined sets of first modules dependent upon the given processing mode. Preferably, to each processing mode of the third module, i.e. to each kind of processing of first data, a respective set of first modules, from which captured first data are retrieved by the second module and forwarded to the third module, is assigned. In this manner, it is ensured that all necessary first data, which are required with a certain processing mode, are available at the third module, in particular at a pre-defined point in time.
[0024] Within the meaning of the present invention, the term “processing mode” preferably relates to a pre-defined kind of processing of the first data, e.g. by calculating values based on retrieved or obtained data, like summation, and/or compiling retrieved or obtained data and/or generating a document based on retrieved or obtained data or calculated values based on retrieved or obtained data.
[0025] Preferably, the given processing mode depends upon a given object, to which the captured or generated first data relate. Additionally or alternatively, the third module is adapted for automatically selecting the processing mode dependent upon the given object, to which the captured or generated first data relate. For example, first data captured from a first object or from a first kind of objects are processed in a first processing mode, whereas first data captured from a second object or a second kind of objects are processed in a second processing mode etc. In this way, it is ensured that first data captured in relation to a given object or kind of objects are available for data processing according to a processing mode which is associated with the given object or kind of objects, respectively.
[0026] Within the meaning of the present invention, the term “given object” preferably relates to a patient and/or a medical case.
[0027] According to a further preferred embodiment, the at least one second module being adapted for assigning a processing mode to a pre-defined set of first modules. Thus, first data retrieved from each pre-defined set of first modules are processed according to the processing mode assigned thereto. For example, first data retrieved from a first pre-specified set of first modules are processed in a first processing mode, whereas first data retrieved from a second pre-specified set of first modules are processed in a second processing mode. By this, it is ensured that first data captured by a certain set of first modules are always processed according to a processing mode associated with that certain set of first modules.
[0028] It is also preferred that the at least one second module is adapted for generating and/or storing one or more pre-defined sets of first modules. Alternatively or additionally, the second module is adapted for receiving pre-defined sets of first modules, e.g. via an interface or a user input unit.
[0029] According to a further preferred embodiment of the invention, the third module is adapted for generating second data based on the processing of the first data. Further, the third module can be adapted for generating an output, in particular via a display and/or a hardcopy device, of the second data. For example, the second data are calculated from the first data by summation, subtraction, multiplication or division. Because of the second module's request to a pre-specified set of first modules to forward captured first data, it can be ensured that all necessary first data, i.e. all first data captured by the pre-specified set of first modules, are available for the calculation of the second data from the first data yielding complete and accurate calculation results.
[0030] Moreover, it is preferred that the at least two first modules are adapted for generating and/or capturing the first data upon one or more events related to an object. One or more events related to the object may be, e.g., a registration of the object or a start or termination of a treatment of the object. By this, it is ensured that first data are available as soon as a pre-defined event has occurred. In combination with retrieving first data generated and/or captured by a pre-defined set of first modules it can be ensured that in the third module all event-related first data of the pre-specified set of first modules are considered in the processing step. Accordingly, in the result of the processing of the first data, e.g. in a calculated sum of values corresponding to the first data, all relevant information about all of the events related to the object is considered.
[0031] Apart from processing sensor data, the invention and its preferred embodiments can be advantageously applied in other fields of data processing. Preferably, the first modules for generating or capturing first data can be any kind of data capturing modules, e.g. modules for capturing first data relating to treatments and/or services rendered to a patient or in connection with a medical case, e.g. in a hospital. Preferably, the second module can be a service collector module for retrieving first data from a pre-defined set of said first modules. Preferably, the third module can be a billing module for processing the first data which were retrieved by the service collector module and for generating a bill based on the retrieved first data and/or relating to the services captures by the first modules of the pre-defined set of said first modules. Accordingly, one or more events related to the object preferably correspond to a treatment of and/or a service rendered to the object, in particular a patient or a medical case. Moreover, the first data preferably relate to a treatment of and/or a service rendered to an object, in particular a patient or a medical case.
[0032] Further advantages, features and examples of the present invention will be apparent from the following description of following figures:
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 shows an example of a first system for data processing.
[0034] FIG. 2 shows an example of a second system for data processing.
[0035] FIG. 3 shows an example of a first section of a data processing workflow.
[0036] FIG. 4 shows an example of a second section of the data processing workflow.
[0037] FIG. 5 shows examples of embodiments of components and/or modules of the system for data processing.
[0038] FIG. 6 shows examples of embodiments of further components and/or modules of the system for data processing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0039] FIG. 1 shows an example of a first system for data processing comprising first modules M 11 to M 17 , a second module M 2 and a third module M 3 . The first modules M 11 to M 17 are adapted for generating and/or receiving first data relating to objects C 1 , C 2 and C 3 .
[0040] For example, the first modules M 11 to M 17 comprise and/or constitute medical devices and/or sensors, like optical sensors and/or ultrasound sensors for detecting electromagnetic radiation, e.g. x-rays or light, or ultrasound waves, respectively, emanating from objects C 1 , C 2 and C 3 under investigation, e.g. patients or body parts thereof. Based on the detected radiation or waves, respectively, first data are generated by the sensors.
[0041] Alternatively or additionally, at least a part of the first modules M 11 to M 17 are adapted to receive signals from sensors and/or medical devices, e.g. an x-ray, CT or MRT apparatus, an ultrasound apparatus or an electrocardiograph, relating to objects under investigation. Preferably, the received signals are converted by the first modules M 11 to M 17 into the first data. Alternatively, the received signals constitute the first data without prior conversion.
[0042] Preferably, the first modules M 11 to M 17 constitute and/or comprise input modules enabling an input of first data. For example, the first modules M 11 to M 17 comprise a barcode scanner for reading barcode data relating to services rendered to an object C 1 , C 2 or C 3 , e.g. a patient, and/or a keyboard enabling a user, e.g. a nurse, to input first data relating to services rendered to the object C 1 , C 2 or C 3 into the first modules M 11 to M 17 . The rendered services can be various kinds of activities in a hospital, like administering medicaments or medical consumables, performing a medical checkup or treatment, recruitment or discharge of patients.
[0043] The first data generated and/or received by the first modules M 11 to M 17 are forwarded to the second module M 2 , as indicated by dotted and dashed lines between the first modules M 11 to M 17 and the second module M 2 . Basically, the first modules M 11 to M 17 can be designed to forward first data, whenever first data have been generated or received by a first module. It is, however, particularly preferred that the second module M 2 sends a request to one or more of the first modules M 11 to M 17 to forward possibly available first data to the second module M 2 . In other words, only those first modules M 11 to M 17 which get a respective request from the second module M 2 will forward first data, if available, to the second module M 2 .
[0044] Preferably, the second module M 2 sends according requests only to first modules of one or more pre-defined sets S 1 , S 2 and S 3 of first modules. In the example given in FIG. 1 , in a first pre-defined set S 1 three first modules M 12 , M 14 and M 16 are defined, whereas in a second pre-defined set S 2 two first modules M 11 and M 15 and in a third pre-defined set S 3 three first modules M 13 , M 16 and M 17 are defined.
[0045] When calling the first modules M 12 , M 14 and M 16 of the first pre-defined set S 1 by the second module M 2 , first data available at the first modules M 12 , M 14 and M 16 at the point of time of the call are forwarded via the second module M 2 to the third module M 3 (see dotted lines), where the retrieved first data are processed dependent upon a first processing mode P 1 .
[0046] Accordingly, when calling the first modules of the second or third pre-defined set S 2 or S 3 , only first data available at the first modules M 11 and M 15 or M 13 , M 16 and M 17 , respectively, are forwarded via the second module M 2 to the third module M 3 (dashed lines), where the retrieved first data are processed dependent upon a second processing mode P 2 .
[0047] It is preferred that one or more pre-defined sets S 1 to S 3 of first modules can be defined, e.g. via user input into second module M 2 , by specifying respective first modules of one or more particular sets S 1 to S 3 . By this, the second module M 2 becomes configurable and/or customizable and can be easily adapted to desired applications, e.g. an evaluation of sensor data of various pre-defined sensors or a processing of data relating to various pre-defined medical devices or medical services.
[0048] Preferably, to a given object C 1 , C 2 or C 3 a particular processing mode P 1 , P 2 for processing first data generated and/or received in connection with the object C 1 , C 2 or C 3 is assigned. In the present example of FIG. 1 , in module M 2 a lookup table is provided by which a certain processing mode P 1 or P 2 for a given object C 1 , C 2 or C 3 is retrieved or determined. For example, for a first and third object C 1 and C 3 a first processing mode P 1 is retrieved (“C 1 : P 1 ”, “C 3 : P 1 ”), whereas for a second object C 2 a second processing mode P 2 is retrieved (“C 2 : P 2 ”). Preferably, the lookup table including the assignments between objects C 1 , C 2 , C 3 and processing modes P 1 , P 2 is freely configurable, e.g. via user input, or is generated automatically.
[0049] Moreover, it is preferred that to a certain processing mode P 1 , P 2 one or more pre-defined sets S 1 , S 2 and S 3 of first modules are assigned. As obvious from the example given in FIG. 1 , in module M 2 a further lookup table is provided according to which the first pre-defined set S 1 of first modules is assigned to the first processing mode P 1 and the second and third pre-defined sets S 2 and S 3 of first modules are assigned to the second processing mode P 2 . The second module M 2 is adapted for determining or retrieving one or more pre-defined sets S 1 to S 3 of first modules dependent upon the processing mode P 1 , P 2 by the further lookup table.
[0050] According to the present example, for a desired object C 1 , e.g. a patient or a medical case, the second module M 2 determines a first processing mode P 1 assigned to this object C 1 . By the determined processing mode P 1 , the second module M 2 subsequently determines the first pre-defined set S 1 of first modules M 12 , M 14 and M 16 and sends a request to these modules to forward available first data, which were generated and/or received in first modules M 12 , M 14 and M 16 in connection with measurements on and/or treatments of object C 1 , to the second module M 2 and/or the third module M 3 (see dotted lines). In the third module M 3 first data from first modules M 12 , M 14 and M 16 are processed according to processing mode P 1 . Same applies accordingly for a desired object C 3 .
[0051] For a desired object C 2 a second processing mode P 2 is retrieved. By the retrieved processing mode P 2 , the second module M 2 determines the second and third pre-defined sets S 2 and S 3 of first modules M 11 , M 15 and M 13 , M 16 , M 17 , respectively, and sends a request to these modules to forward available first data, which were generated and/or received these first modules in connection with measurements on and/or treatments of object C 2 , to the second module M 2 and/or the third module M 3 (see dashed lines). In the third module M 3 first data from first modules M 11 , M 13 , M 15 , M 16 and M 17 are then processed according to processing mode P 2 .
[0052] By the first system described above it is ensured that all generated and/or captured first data required with a data processing step according to a given processing mode P 1 and/or P 2 are made available at the third module M 3 at a certain point of time for being processed in the given processing mode P 1 or P 2 .
[0053] FIG. 2 shows an example of a second system for data processing. The given example represents a particularly preferred application of the invention in a hospital information system (HIS). As will be described in more detail below, the second system corresponds to a HIS client by which a customizable and/or configurable assignment of chargeable services rendered to a patient or a medical case from all possible sources is achieved in order to provide a basis for an invoice relating to the rendered services.
[0054] According to the present example, a number of HIS modules M 1 to Mn, which correspond to the first modules described above, are provided for generating services or for capturing data relating to services rendered to a patient or in connection with a medical case. In particular, the HIS modules M 1 to Mn create services from internal service capturing, generated grouping results, organization structure configurations or external interfaces and assign them to the patient.
[0055] To each of the HIS modules M 1 to Mn a service collector module S 1 to Sn is assigned. The service collector M 2 , which corresponds to the second module described above, is configurable and/or customizable in such a way that for a given patient, a given medical case and/or a given accounting or billing mode one or more service collector modules S 1 to Sn can be pre-defined, wherein the pre-defined service collector modules S 1 to Sn call all of the corresponding assignment modules M 1 to Mn for a chargeable patient or medical case, respectively. By this, a collection of services of configurable, i.e. pre-defined, assignment modules M 1 to Mn can be extended anytime and can be simply achieved by configuring or pre-defining corresponding service collector modules S 1 to Sn.
[0056] Service-related data, which correspond to the first data mentioned above, of the configured HIS modules M 1 to Mn are collected by the service collector M 2 and entered into a list of services to be invoiced. Upon completion of this list, according invoices are generated. As indicated in the example given in FIG. 2 , the list of services to be invoiced and a sub-module for generating according invoices can be part of a billing module M 3 , which corresponds to the third module described above. Moreover, a part of the service collector M 2 can also be integrated into the billing module M 3 . Alternatively, it is possible to provide the service collector M 2 and the billing module M 3 as separate modules which are connected via appropriate data links.
[0057] By the described application of the invention it is ensured that all service-related data captured and/or available at a pre-defined set of HIS modules M 1 to Mn are forwarded to the billing module M 3 such that all of these data are available in the billing module M 3 at a desired point of time and, therefore, can be considered in a data processing step, in particular when calculating and/or generating invoices relating to the rendered services. Besides, the elucidations and advantages set forth above in connection with the example of FIG. 1 apply accordingly.
[0058] In the following, an example of a preferred data processing workflow is given by FIGS. 3 and 4 .
[0059] As obvious from FIG. 3 , after starting the data processing workflow medical cases, e.g. patients, for service assignment are selected, e.g. by a user. Then the service collector is initialized, wherein a module factory instance is created and a lookup catalogue of service collector modules is created, i.e. defined. In the case that not all of the service collector modules have been processed, a next service collector module instance is created. If all the service collector modules are processed, then the service collector initialization is terminated.
[0060] If not all of the selected medical cases have been processed, a next case is fetched and the service collector is called for the current medical case.
[0061] As detailed in FIG. 4 , upon starting the called service collector for a current case an accounting mode for the current case is determined, e.g. by a pre-defined list or lookup table. Then, the configured collector modules for the current accounting mode are determined, e.g. by a pre-defined list or lookup table.
[0062] If not all of the configured collector modules have been processed, a next module for the current medical case is called, the assigned services of this module are recorded or, if applicable, error messages are displayed. If all of the configured collector modules are processed, the call of the service collector for a single case is terminated.
[0063] As obvious from FIG. 3 again, it is examined whether all selected medical cases have been processed. If not, fetching the next case and calling the service collector for that case is repeated and so on. If yes, the service collector is finalized.
[0064] FIGS. 5 and 6 show further preferred implementations of the system for data processing.
Service Collector Module
[0065] Preferably, the service collector module is implemented as a Java class, i.e. a class of data (attributes) and methods for processing these data in the class-based, object-oriented computer programming language Java. Java applications are typically compiled to bytecode (class file) that can run on any Java virtual machine (JVM) regardless of computer architecture.
[0066] The functions which have to be provided by this Java class in order to be used by the service collector framework are defined in an interface (collector::IService-CollectorModule) which contains a method for assigning services rendered to a medical case, i.e. an inpatient or outpatient furnished as a parameter, in a defined period of time.
[0067] For generating and furnishing the services to the accounting system a standardized import interface (IServiceAssignmentAPl) is used. By this it is ensured that the services are uniformly assigned to a medical case throughout all modules, i.e. assigned to a medical case independently from the respective type of the module. Moreover, while assigning a service one or more unique identification code(s) (ID) are generated. The framework provides functions for logging and, in the case of a later requirement of the module, determining the ID again.
[0068] In the case that a module is called several times for a medical case, it considers the status (assigned, billed, cancelled etc.) of already assigned services by the ID generated with the first assignment of services.
[0069] The decision as to the services which have to be assigned, depends on the logic of the modules.
[0070] The available service collector modules are communicated to the system via an extensible catalogue. A catalogue is a country-specific list of entries, the visibility and modifiability of which can be controlled by a user, i.e. the user can add his/her own service collector module implementation, if need arises. Alternatively, the catalogue is configured to be specifiable in a programming or implementation stage of the system only.
[0071] An entry into the catalogue for a service collector module comprises a unique ID, a name visible to the user, a period of validity, and a name of the implemented Java class.
[0072] In the following, examples for service collector modules are given for assigning:
services within a certain period of time base on a stay of a patient in certain departments/stations/rooms case-based lump sums and procedural rates based on available grouping results (DRG, PEPP) services for the handling of co-payments (credit notes, reclaims, administration charges, reminder fees) external services (agreed with the payer) arising from an internal catalogue (tariff-neutral services)
Configuration of the Service Collector
[0077] Each medical case, i.e. inpatient or outpatient, in the system is labeled with a billing category which is, like the service collector modules, specified in a catalogue.
[0078] By 1: n links between the billing categories and the service collector modules it is controlled which service collector modules are called for each of the medical cases.
Service Collector
[0079] The service collector (collector::ServiceCollector) is responsible for the course of the assignment. It is realized as a singleton. The generation of the instance comprises a browsing of the catalogue of the service collector modules and a generation, via reflection by a factory defined by an interface (collector::IServiceCollectorModuleFactory), and registration of the available modules.
[0080] In the case that a medical case is furnished to the service collector, it determines the registered modules necessary for the given billing category by the service collector configuration and further delegates the call to the registered modules (ServiceCollectorModuleImpl).
[0081] The information contained in the return values (collector::ServiceCollector-Results, e.g. number of services rendered, possible error messages) are visualized for the user and the IDs of the assignments are logged, i.e. stored in a data base. | A system and corresponding method for data processing, in particular sensor data processing, includes at least two first modules that generate or capture first data, at least one second module that retrieves the first data from first modules which correspond to first modules of at least one predefined set of first modules, and a third module that processes the first data which were retrieved by the at least one second module. The relevant data captured by a plurality of different data capturing modules, in particular sensors, are made available in a processing module in a fast and reliable manner. | 6 |
FIELD OF THE INVENTION
The present invention relates to the field of adjustable mounting hardware for mounting and supporting an enclosure or other object from an architectural mass such as a wall, more particularly it relates to a ball swivel clamping mechanism, contained inside a rear region of an enclosure, typically a loudspeaker enclosure, that can be adjusted, locked and released from a convenient frontal location.
BACKGROUND OF THE INVENTION
There are many requirements for mounting an object such as an enclosed loudspeaker onto a wall in both residential and public locations. Generally the enclosure is rectangular and is simply fastened flat against the wall in a parallel relation. However, in many instances where such parallel or orthogonal orientation is unsatisfactory, swivel mountings have been utilized, typically attached onto the rear of the enclosure. Such structure has generally suffered the shortcoming that the required access to the mechanism at the rear of the enclosure for orientation adjustment, installation or removal is inconvenient.
DISCUSSION OF RELATED KNOWN ART
Ball-and-socket type mounting hardware of known art has been utilized in the general field of the present invention, however with regard to loudspeakers enclosures and the like, swivel mounting hardware of known art attached externally onto the rear of the enclosure has tended to be not only unsightly but inconvenient with regard to clamping in place due to the poor accessibility to clamping mechanism located at the rear of the supported enclosure.
U.S. Pat. No. 5,251,859 to Cyrell et al, assigned to Omnimount Systems, exemplifies a ball type adjustable support that can support an audio loudspeaker. Attached to the rear if the enclosure and extending rearwardly therefrom is a mechanism having a fixed clamp plate, co-operating with a removable jaw plate to engage a ball attached by a rod to building structure. Such structure is unsightly due to the bulk of the clamp plate and jaw plate protruding to the rear; also it is inconvenient to clamp and/or release the ball for speaker orientation since this must be performed in an inaccessible and often "blind" region behind the speaker enclosure.
In view of known art of swivel enclosure mounting, there is an unfullfilled need for improvements that provide better appearance and more convenient adjustment of orientation and clamping in the selected orientation; more particularly such adjustment should be concealed within the enclosure and made available from a frontal region thereof.
OBJECTS OF THE INVENTION
It is a primary object of the present invention to provide, for mounting an enclosure such as a loudspeaker enclosure to a wall or other architectural mass, an adjustable swivel socket mechanism that is enclosed within the enclosure for mating with a swivel mounting ball on a cantilever shaft, typically secured to a wall by a mounting flange.
It is a further and equally important object that the enclosure and the swivel mechanism be constructed and arranged to be easily installed, oriented, locked in place, released and removed from a working location to the front of the enclosure.
SUMMARY OF THE INVENTION
The abovementioned objects have been accomplished by the present invention of a ball-and-socket type mounting mechanism, contained within the enclosure, having a fixed jaw and a movable jaw that can be adjusted through an opening in the front of the enclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and further objects, features and advantages of the present invention will be more fully understood from the following description taken with the accompanying drawings in which:
FIG. 1 is a three-dimensional view of a loudspeaker enclosure shown separated from a wall-mounted ball portion of a ball-and-socket mounting assembly, as seen from a forward viewpoint, indicating front-panel adjustment access in accordance with the present invention.
FIG. 2 depicts the subject matter of FIG. 1 as seen from a rearward viewsoint showing the absence of any external mounting mechanism, in accordance with the present invention.
FIG. 3 is a cross-sectional side view of the loudspeaker enclosure of FIG. 1 taken through central axis 3-3', showing the ball clamped in place in a socket mechanism of the present invention located within the enclosure.
FIG. 4 is a cross-sectional side view of the socket mechanism of FIG. 3 showing the movable jaw retracted and the ball in process of removal.
FIG. 5 is a cross-sectional side view of the ball socket mechanism of FIGS. 3 and 4 shown in an initial shipping condition.
FIGS. 6A-E are the following views of the ball socket mechanism housing of FIGS. 3-5: elevational side, front, rear, top and bottom, respectively.
FIGS. 6F and 6G are cross-sectional views of the ball socket mechanism housing of FIGS. 3-5 taken through axis 6F and 6F' of FIG. 6D respectively.
FIGS. 7A-7E are the following views of the movable jaw part of the ball socket mechanism of FIGS. 3-6: elevational side, front, rear, top and bottom, respectively.
FIG. 7E is a cross-sectional view of the movable jaw part of the ball socket mechanism of FIGS. 3-6 taken through axis 7F of FIG. 7D.
DETAILED DESCRIPTION
FIG. 1 is a three-dimensional view of a loudspeaker enclosure 10 utilizing a ball-and-socket swivel-mount of the present invention. The enclosure 10 is shown separated from a ball portion 12 of the mount having a ball 12A at the end of a mounting arm 12B, typically a round shaft or tube mounted in cantilever fashion by a flange 12C to a wall 14, shown in part. The front of the enclosure 10 is covered by a grille 16 which is provided with an access aperture 16A through which a tool can be inserted to manipulate the enclosed swivel-mount socket mechanism.
FIG. 2 is a three-dimensional view of the subject matter of FIG. 1 as seen from a viewpoint located to the rear of the enclosure 10 and wall 14, revealing, as part of the rear panel 10A, a generally rectangular enclosure plate 10B mounted centrally and defining a circular ball opening 10C for entry of ball 12A.
FIG. 3 is a cross-sectional side view of the loudspeaker enclosure 10 taken through axis 3-3' of FIG. 1. Ball 12A, which may be formed integrally with shaft 12B as shown, has entered the enclosure 10 through ball opening 10C of enclosure plate 10B and has entered a socket mechanism assembled in a housing frame 20 configured with two side plates 20A spaced apart by two integrally-joined cross-members: a fixed jaw 20B at the bottom rear and an adjustment screw block 20C at the top front. Ball 12A is clamped in place between fixed jaw 20B and a movable jaw part 22 which is a separate part pivoted on a pin 24 and thus retained in housing frame 20.
Rear panel 10A of the main enclosure body is formed internally to provide a sub-enclosure 10D which surrounds and supports the socket mechanism housing frame 20 and which retains pin 24 in place between the two opposite side plates 20A.
An adjustment screw 28 is threaded through a nut 30 which is retained in a cavity in adjustment screw block 20C whose open upper side is enclosed by the top portion of sub-enclosure 10D. The rear of housing frame 20 becomes enclosed by a portion of enclosure plate 10B.
A screwdriver 26 is shown inserted through aperture 16A of front grille 16 and through a guide tube 18B, which is formed integrally with the front panel 18. Screwdriver 26 is shown engaging the head of adjustment screw 28, which can be threadedly tightened against a vertical screw bearing surface on movable jaw part 22 so as to clamp it onto ball 12A against fixed jaw 20B.
Fixed jaw 20B is configured with a downwardly-extending tailpiece 20D which is integrally joined by a pair of integrally-formed end brackets 20E, one at each side of tailpiece 20D, to a crossbar 20F thus forming a loop that extends to the rear into a cavity 10E formed in enclosure plate 10B. This loop, which is accessible from outside the enclosure 10, can be utilized to tether a safety cable such as may be required by earthquake/fire safety regulations in public locations.
The upper portion of the front panel 18 is shaped to form a tweeter horn 18A including a mounting interface for a tweeter driver 32 shown in outline. The lower portion of the front panel 18 is formed with an opening to mount a woofer speaker 34 shown in outline.
Mounting facilities are provided inside enclosure 10 for associated components such as crossover networks. Component 36 is shown mounted to rear panel 10A via internal and external metal plates 36A and 36B which provide heat dissipation and structural strength. Auxiliary components 38 and 40 are shown as representing items for which mounting facilities such as integral threaded bushings may be provided in the molding of the main body of enclosure 10.
The available range of orientation of the enclosure is indicated by dashed outlines 12B' and 12B" showing ball shaft 12B at the limits of the angle formed by ball shaft 12B relative to the enclosure 10. Of course, in an installed situation, shaft 12B remains fixed while the enclosure 10 can be oriented within the range indicated.
The enclosure 10 is seen to consist of two main parts: (1) the main enclosure body including the top, side and bottom panels, back panel 10A including enclosure plate 10B and sub-enclosure 10D, and (2) the front panel 18 including horn 18A and guide tube 18B.
FIG. 4 is a cross-sectional side view of the socket mechanism in housing frame 20 contained within sub-enclosure 10D of FIG. 3, showing adjustment screw 28 backed off so as to retract movable jaw part 22 sufficiently to release ball 12A and allow it to pass through opening 10C of enclosure plate 10B as shown, as required for initial installation and for removal of the enclosure from the wall-mounted ball assembly.
FIG. 5 is a cross-sectional side view of the socket mechanism in housing frame 20, similar to FIG. 4 but shown in an initial shipping condition wherein enclosure plate 10B as originally fabricated and supplied includes a round knockout plug 10F fitted with a screwdriver slot 10G. Plug 10F includes a cantilevered shelf 10H extending inwardly upon which movable jaw part 22 is shown resting; in this condition, movable jaw part 22 may be urged downwardly upon shelf 10H by rotating screw 28 for the purpose of securing movable jaw part 22 against looseness and rattling that could otherwise occur during initial shipment and handling.
Plug 10F is initially attached around its circular edge to plate 10B by an intentionally weak joint that can be broken away by leverage of a screwdriver applied in slot 10G so that plug 10F can be removed and discarded at the time of initial installation, leaving exposed the opening 10C (FIGS. 3 and 4) in place of plug 10F.
FIGS. 6A-E are following orthogonal views of the mechanism housing frame 20 shown in FIGS. 3-5: elevational side, front, rear, top and bottom views respectively, showing housing frame 20 and its cross-members: fixed jaw 20B and screw-adjustment block 20C.
FIG. 6A is an elevational view of one of the two symmetrical side plates 20A of mechanism housing frame 20, showing one of the two end brackets 20E extending down from the bottom. Hole 20G is provided for pivot pin (24, FIG. 3).
FIG. 6B, the front view of housing 20, shows cross-member screw-adjustment block 20C defining a U-shaped journal 20H through which adjustment screw (28, FIGS. 3-5) can be accessed by a screwdriver, and shows tailpiece 20D extending downwardly.
FIG. 6C, the rear view of housing 20, shows, at the top, a U-shaped journal 20J in cross-member block 20C for supporting the rear portion of the adjustment screw (28, FIGS. 3-5), and shows crossbar 20F at the bottom.
FIG. 6D, the top view of housing 20 shows the scalloped edge pattern of socket recess 20K formed in the cross-member fixed jaw 20A for ball engagement. Also shown are journals 20H, 20L and 20J formed in crossmember block 20C: the cavity formed between journals 20H and 20L provides space for the head of the screw (28) and cavity between journals 20L and 20J captivates the nut (30).
FIG. 6E, the bottom view of the housing 20, shows the combination of crossbar 20F, two side brackets 20E and tailpiece 20D forming a loop, as shown, that will protrude through the rear of the enclosure, available for safety cable attachment if required.
FIGS. 7A-7E are the following views of the movable jaw part 22 of the ball socket mechanism of FIGS. 3-5: elevational side, front, rear, top and bottom views respectively.
FIG. 7A is an elevational side view of one of two symmetrical sides of movable jaw part 22 configured to have an adjustment screw bearing surface 22A and support gusset 22B.
FIG. 7B is a front view of movable jaw part 22, showing bearing surface 22A.
FIG. 7C is a rear view of movable jaw part 22 showing the support gusset 22B.
FIG. 7D, the top view of movable jaw part 22, shows screw bearing surface 22A and support gusset 22B.
FIG. 7E, the bottom view of movable jaw part 22, shows the scalloped pattern of the socket recess 22C for ball engagement, configured the same as the fixed jaw socket recess (20K, FIG. 6D).
FIG. 7F is a cross-sectional view taken through axis 7F-7F' of FIG. 7D.
Referring once again to FIGS. 3-5, typically the mechanism housing frame 20 (which includes two side plates 20A with two cross-members: fixed jaw 20B and adjustment screw block 20C) and the movable jaw part 22 are preferably die cast from aluminum, while the two parts of the main enclosure 10 (front panel 18 including horn 18A and guide tube 18B, and rear enclosure including rear panel 10A, enclosure plate 10B and sub-enclosure 10D) are preferably injection-molded from high impact polystyrene plastic.
Sub-enclosure 10D, shown molded integrally with the enclosure rear panel 10A, could alternatively be made as a separate part and attached to rear panel 10A by known fastening means.
As an option, a coaxial passageway may be provided through ball 12A and shaft 12B (FIG. 3) such that shaft 12B would form a tubular conduit for enclosing speaker connecting wires from behind the wall to the interior of the enclosure, thus providing the aesthetic advantage of concealing the speaker wires.
The adjustment screw and the corresponding tool could be made with a screw-head style different than the regular slot head described above: this could be another conventional style such as Philips, square or hex socket, or it could be a specialized proprietary style to prevent unauthorized adjustment or removal. Alternatively the threaded element of the adjustment screw could be extended by a shaft to a front or side exterior location of the enclosure where a knob or other means could be provided to enable clamping adjustment without need for a tool.
The principle of the invention may be applied to loudspeaker enclosures of various sizes and with different loudspeaker complements, to enclosures other than loudspeaker enclosures and to other objects requiring a similar kind of adjustable pivoted support from a relatively fixed mass.
The invention may be embodied and practiced in other specific forms without departing from the spirit and essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description; and all variations, substitutions and changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. | For adjustably mounting an enclosure such as a loudspeaker to an architectural mass such as on a wall, a ball-and-socket swivel mounting mechanism is enclosed within a rear region of the enclosure, thus eliminating unsightly conventional external swivel-mounting apparatus. A mounting ball, at the end of a shaft cantilevered to the wall, enters the mounting mechanism through a circular opening in a central region of the rear panel of the enclosure. The ball is clamped between a fixed jaw and a movable jaw actuated by an adjusting screw via which the jaw-clamping force can be applied, adjusted and released by a tool inserted through an opening in the front of the enclosure and directed by an internal guide tube to engage the adjusting screw; thus all installation, orientation adjustment, clamping in place and removal of the enclosure can be performed conveniently from the front of the enclosure. | 5 |
This application is a national stage completion of PCT/EP2006/003040 filed Apr. 4, 2006, which claims priority from German Application Serial No. 10 2005 018 012.4 filed Apr. 18, 2005.
FIELD OF THE INVENTION
The invention relates to an electromagnetic actuator comprising at least two coils, an armature and a control or power electronics element and to a method for controlling such an actuator.
BACKGROUND OF THE INVENTION
DE 103 10 448 A1 discloses an electromagnetic actuator comprising two coils and an armature. By applying a current to the coils, the armature is displaced in the axial direction.
DE 199 10 497 A1 describes a method, according to which the position of an armature in an actuator is detected with a coil by determining the differential induction of the coil. For this purpose, the current decrease time during a drop in current is determined as a time difference between two threshold values. The current drop time is highly dependent on the resistance of the coil, which is temperature-dependent.
Furthermore, DE 100 33 923 A1 discloses a method, according to which the position of an armature is determined as a function of the counter-induction created by the movement of an armature in a coil. The counter-induction is dependent on the velocity of the armature. If such an actuator is used in a fluid-filled space, the velocity of the armature is highly dependent on the viscosity of the fluid. Also the viscosity of the fluid is dependent on the temperature.
It is therefore the object of the invention to enable determination of the position of an actuating member in an electromagnetic actuator without additional sensors, wherein the position determination in particular is supposed to be independent of the temperature.
SUMMARY OF INVENTION
According to the invention, an actuator is proposed, which comprises at least two coils, an armature and a control or power electronics element. The power electronics element is connected to a logic unit and is controlled by the same. The power electronics element at least comprises switches, which are switched on or off, enabling or interrupting a power supply. Current can be applied to the two coils via the switches. According to the invention, the armature can be displaced and/or the position of the armature can be measured by controlling the current in the coils. The armature is slidably mounted between the two coils and can be displaced back and forth between two end positions, such that the armature may also assume intermediate positions. A measurement amplifier is connected to the two coils, respectively, and measures the voltage gradient at the coils over time. The measurement signals of the measuring amplifiers are forwarded to a differentiator. In the subtractor, a third voltage gradient is computed from the measurement signals, the gradient comprising a maximum value that is dependent on the position of the armature. This is based on the fact that the inductance of a coil increases when an armature is inserted. Since the resistance of a coil depends on the inductance thereof, the armature position influences the voltage gradient. The logic unit detects the maximum value of the third voltage gradient and computes the armature position as a function thereof.
In one embodiment, the power electronics element comprises 3 or 4 switches. The logic unit comprises, for example, a μ controller or μ processor.
The equivalent circuit of one of the at least two coils can be represented for alternating current models by a familiar oscillating L-C-R circuit. Such an oscillating circuit is made of first and second alternating current resistors connected in parallel. The first alternating current resistor comprises a model coil and an ohmic resistor connected in series, the second alternating current resistor comprises a capacitor and a further ohmic resistor connected in series. Both alternating current resistors are dependent on the frequency of the excitation. According to the invention, a voltage jump is applied to the coils by applying sudden current. This moment, the switch-on moment, can be achieved by applying alternating current with infinitely high frequency f→∞ to the coils. The alternating current resistance of the model coils depends on the coils' inductance. Since the inductance of a coil increases when an armature is inserted therein, the alternating current resistances of the model coils change as a function of the armature position.
According to the invention, the voltage gradients at the two coils are measured by the measurement amplifiers. If a sudden increase in voltage is applied to the coils and the armature is not located in the center between the two coils, two different voltage gradients are produced in the two coils. These are subtracted from one another in the subtractor, resulting in a gradient with a maximum value corresponding to the armature position. This third voltage gradient is forwarded to a logic unit, which recognizes the maximum value. In accordance with the maximum value, the logic unit can determine the armature position, for example by comparison with a characteristic diagram.
By forming the difference between the two voltage gradients, the influence of interference acting on the two coils is also excluded. In known actuators comprising only one coil, for example, electromagnetic interferences may influence the voltage gradient in the coil and thus the position determination. In one advantageous embodiment, two identical coils are used, creating an electromagnetically symmetrical actuator. In this way, interference on the two coils always has the same effect. Since the two voltage gradients of the two coils are subtracted from each other, this interference has no influence on the measurement result. Furthermore, temperature effects are excluded by the inventive solution. By applying a voltage jump to the coils, the ohmic portion of the alternating current resistance is negligibly small compared to the frequency-dependent portion of the alternating current resistance. As a result, at the time the voltage jump is applied, the voltage gradient depends on the frequency-dependent portion of the alternating current resistance, which is dependent on the position of the armature, but not on the ambient temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described, by way of example, with reference to the accompanying drawings in which:
FIG. 1 is a schematic diagram of an actuator;
FIG. 2 is a schematic diagram of an actuator comprising a permanent magnet armature;
FIG. 3 is a schematic diagram of an LCR oscillating circuit;
FIG. 4 are the measured voltage gradients at the two coils, and
FIG. 5 is the computed voltage gradients from the two coils.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an electromagnetic actuator comprising two coils 1 , 2 and an armature 3 . The armature 3 is slidably mounted between the two coils 1 , 2 . The input of the first coil 1 is connected to a first pole 5 of a power source 6 . The output 7 of the first coil 1 can either be connected to the second pole 9 of the power source 6 , via a first switch 8 , or to the input 11 of the second coil 2 via a third switch 10 . The input 11 of the second coil 2 can either be connected to the first pole 5 of the power source 6 , via a second switch 12 , or to the output 7 of the first coil 1 , via a third switch 10 . The three switches 8 , 10 , 12 form the power electronics element of the actuator. The output 13 of the second coil 2 can in turn be connected to the second pole 9 of the power source 6 . A measurement amplifier 14 , 15 is connected to the input and output 4 , 7 of the first coil 1 and the input and output 11 , 13 of the second coil 2 , respectively. The measuring amplifiers 14 , 15 are connected to the subtractor 16 , which is connected to the logic unit 17 to which it forwards the data. The logic unit 17 controls the three switches 8 , 10 , 12 . The three switches 8 , 10 , 12 can be controlled such that either the armature 3 is displaced or that a voltage jump is applied to the two coils 1 , 2 . If the logic unit 17 controls the first and second switches 8 , 12 such that they are opened and at the same time the third switch 10 is closed, a voltage jump is applied to the two coils 1 , 2 . At the moment of application, the position of the armature 3 is determined from the voltage gradient at the two coils 1 , 2 . The arrangement according to the invention thus enables detection of the position of an actuating member without using an additional sensor. In this way, cost and installation space can be saved.
FIG. 2 shows a further embodiment of an electromagnetic actuator comprising two coils 1 , 2 and an armature 3 . This is a permanent magnet armature. In addition, the two coils 1 , 2 are wound in opposite directions, which is to say that the winding direction of a first coil 1 is opposite from the winding direction of the second coil 2 . The input 4 of the first coil 1 can either be connected to the first pole 5 of the power source 6 , via the first switch 8 , or to the second pole 9 , via the second switch 12 . The output 7 of the first coil 1 is connected to the input 11 of the second coil 2 . The output 13 of the second coil 2 can either be connected to the first pole 5 of the power source 6 via a third switch 10 , or to the second pole 9 , via the fourth switch 18 . A measurement amplifier 14 , 15 is connected to the input and output 4 , 7 of the first coil 1 and to the input and output 11 , 13 of the second coil 2 , respectively. The measurement amplifiers 14 , 15 are furthermore connected to the subtractor 16 . The subtractor 16 forwards data to the logic unit 17 . The logic unit 17 controls the four switches 8 , 10 , 12 , 18 , which form the power electronics element of the actuator. By controlling the power electronics element, the armature 3 can be displaced and the position thereof can be measured at the same time. This arrangement according to the invention thus enables detection of a position of an actuating member without using an additional sensor. In addition, the position can also be measured during the switching processes. This saves cost and installation space in addition to time. In this configuration, the voltage jump is applied by two switch positions. Either the first and fourth switches 8 , 18 or the second and third switches 12 , 10 are closed. In the first case, the input 4 of the first coil 1 is connected to the first pole 5 of the power source 6 and the output 13 of the second coil 2 is connected to the second pole 9 of the power source 6 . In the second case, the input 4 of the first coil 1 is connected to the second pole 9 and the output 13 of the second coil 2 is connected to the first pole 5 of the power source 6 . Since the two coils 1 , 2 are directly connected to one another, both cases produce a voltage jump. In an advantageous embodiment, a pulse width modulating signal is applied to the armature 3 for displacement. Since in the case of such a signal, the voltage is continuously switched on and off, a voltage jump is continuously applied to the coils 1 , 2 . As a result, the position of the armature 3 can be determined at any time that the voltage signal is switched.
FIG. 3 shows the design of a known LCR oscillating circuit 27 , which the coils 1 , 2 may comprise when an alternating current is applied. The input of the oscillating circuit corresponds to the inputs 4 , 11 of the coils. The output of the oscillating circuit corresponds to the outputs 7 , 13 of the coils. The oscillating circuit comprises two paths. The first path is produced by the model coil 19 and a first ohmic resistor 20 and forms a first alternating current resistor 31 . The second path is produced by a capacitor 21 and a second ohmic resistor 22 and forms a second alternating current resistor 32 .
FIG. 4 shows a voltage gradient measured by the measuring amplifiers 14 , 15 at the two coils 1 , 2 . A point in first time 28 describes the switch-on time at which a voltage jump is applied to the two coils 1 , 2 . By way of example, this is achieved by applying an alternating current with an infinitely high frequency f→∞. As a result, the gradient of the voltages at the coils 1 , 2 depends on the respective alternating current resistors 31 , 32 . Up to a second point in time 29 (e.g., 5 ms), a first voltage gradient 23 to a maximum value and the second voltage gradient drops to a minimum value. The gradient up to the first time 28 is based on the influence of the parasitic capacitors 22 . These occur as a function of the operating principle due to the interaction between the individual windings of the coils. The alternating current resistance of a capacitor trends toward zero at f→∞. During the charging of the capacitor, the resistance thereof increases. After the second point in time 29 , a transient oscillation process begins and the current flows through the model coil 19 up to a third time 30 (e.g., 50 ms). The alternating current resistor 31 is dependent on the inductance of the model coil 19 , which in turn depends on the position of the armature 3 . The inductance increases with the distance that an armature 3 is inserted in a coil. At the third point in time 30 , the transient oscillation process is complete and the voltage gradients 23 , 24 are only determined by the two ohmic resistors 20 of the two coils 1 , 2 . At the end of the transient oscillation process, direct current states prevail again. The direct current resistances of the two coils 1 , 2 are advantageously the same, resulting in no difference between the two voltage gradients 23 , 24 any longer. FIG. 4 shows the first voltage gradient 23 , for example the voltage gradient of the first coil 1 when the armature 3 is inserted therein. The second voltage gradient shows the voltage gradient in the second coil 2 .
In the subtractor 16 then the two measured voltage gradients 23 , 24 are subtracted from each other. This produces a third voltage gradient 25 in accordance with FIG. 5 . The maximum value 26 of the third voltage gradient 25 is used in the logic unit 17 to determine the armature position, for example by comparing a characteristic diagram that is stored there.
Reference numerals
1
coil
2
coil
3
armature
4
input of the first coil
5
first pole of a power source
6
power source
7
output of the first coil
8
first switch
9
second pole of a power source
10
third switch
11
input of the second coil
12
second switch
13
output of the second coil
14
first measurement amplifier
15
second measurement amplifier
16
subtractor
17
logic unit
18
fourth switch
19
model coil
20
resistor
21
capacitor
22
resistor
23
first voltage gradient
24
second voltage gradient
25
third voltage gradient
26
maximum value
27
LCR oscillating circuit
28
first point in time
29
second point in time
30
third point in time
31
first alternating current resistor
32
second alternating current resistor | An electromagnetic actuator and a method for controlling the actuator comprising at least one armature ( 3 ) and two coils ( 1, 2 ). The voltage gradient at the two coils ( 1, 2 ) is measured during a sudden increase in voltage. From this measured data, a subtractor ( 16 ) computes a third voltage gradient ( 25 ) from which a logic unit ( 17 ) determines the position of the armature ( 3 ) without the use of an additional sensor. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a throttle valve control apparatus for controlling a flow amount of intake air of an internal combustion engine and a motor vehicle.
[0003] 2. Description of the Prior Art
[0004] An electrical control type throttle apparatus opening and closing a throttle valve of an internal combustion engine by a motor-driven actuator (for example, a direct current motor, a stepping motor, a torque motor and a brushless motor) is put into practice.
[0005] The electrical control type throttle apparatus is structured such as to control an optimum throttle valve angle (throttle valve opening degree) corresponding to an engine state on the basis of an opening degree signal of an accelerator pedal and a traction control signal. For this purpose, a sensor for detecting an angle of the throttle valve, so-called a throttle sensor (which may be sometimes called as an opening degree meter or a throttle position sensor) is attached to a throttle body.
[0006] A potentiometer system is generally employed in the throttle sensor, and a brush (a sliding element) rotating together with a throttle valve shaft slides on a resisting body, thereby outputting a potential difference signal (a sensor detecting signal) corresponding to a throttle valve opening degree (for example, refer to Japanese Unexamined Patent Publication No. 9-32588).
[0007] This kind of conventionally used throttle sensor is structured such that the brush is in contact with a variable resistance and a conductor formed on a resistance base plate so as to slide thereon. Accordingly, a service life of the sensor is short and the sensor is frequently in trouble. A double route of sensor is employed so as to detect a trouble of sensor and mutually back up, however, this can not basically solve the problem.
[0008] Further, since the trouble mentioned above is generated in the conventional motor vehicle at a high possibility, and a control parameter is controlled by an output of the sensor having a short service life, an accuracy for operating and controlling the internal combustion engine is low.
[0009] There has been known Japanese Patent No. 2845884 as a structure for detecting the opening degree of the throttle valve in a non-contact manner.
SUMMARY OF THE INVENTION
[0010] An object of the present invention is to provide a throttle valve control apparatus provided with a throttle sensor which is in trouble at a low possibility and has a long service life.
[0011] In particular, there is suggested some structures for compactly attaching a non-contact type sensor to a throttle control apparatus so as to constitute a part of the apparatus.
[0012] Further, there is suggested structures for removing a magnetic noise and a bad influence against a magnetic characteristic.
[0013] Further, another object is to improve a throttle sensor corresponding to one of elements for controlling control parameters of an internal combustion engine so as to improve an operation control accuracy of the internal combustion engine.
[0014] In order to achieve the objects mentioned above, the present invention proposes the following throttle valve control apparatuses and motor vehicles.
[0015] In accordance with a first aspect of the present invention, there is provided a throttle valve control apparatus of an internal combustion engine comprising:
a throttle valve axis rotated by a motor-driven actuator; an alternate magnet mounted to the throttle valve axis; a cover to which an element for detecting a change of magnetic flux of the alternate magnet is mounted; the cover being mounted to a throttle body to which the motor-driven actuator is mounted; and an output of the element constituting a function of an opening degree of the throttle valve.
[0021] In accordance with a second aspect of the present invention, there is provided a throttle valve control apparatus of an internal combustion engine comprising:
a throttle body provided with a throttle valve controlling an amount of intake air; a throttle sensor detecting a rotational angle of an axis to which the throttle valve is mounted; and a motor-driven actuator in which a command value is adjusted in accordance with an electric signal output from the throttle sensor, wherein the throttle sensor comprises: an element mounted to one end of the throttle valve axis; and another element attached to a cover member fixed to the throttle body so as to cover the axial end portion, and wherein a magnetic physical amount between the pair of elements is varied in accordance with a change of the rotational angle of the throttle axis, and the element mounted to the cover member outputs an electric signal relating to the rotational angle of the axis in response to the change of the magnetic physical amount.
[0029] In accordance with a third aspect of the present invention, there is provided a motor vehicle comprising:
an element outputting an electric signal relating to an opening degree of a throttle valve on the basis of a magnetic signal of a magnet mounted to an axial end of the throttle valve, wherein a control parameter of an engine is adjusted in accordance with a change of the electric signal output from the element.
[0032] In accordance with a fourth aspect of the present invention, there is provided a throttle control apparatus of an internal combustion engine structured such as to transmit a rotation of a motor to a throttle valve axis via a gear fixed to the throttle valve axis,
wherein a rotational angle of the throttle valve axis is detected by a magnetic type throttle sensor comprising a magnet and a hole element, and the gear is formed by a resin material.
[0034] In accordance with a fifth aspect of the present invention, there is provided a throttle valve control apparatus of an internal combustion engine structured such that a rotary axis of a motor and a throttle valve axis are arranged in parallel and a rotation of the rotary axis of the motor is transmitted to the throttle valve axis via a reduction gear,
wherein a magnetic type throttle sensor comprising a magnet and a hole element is mounted so as to be capable of detecting a rotational angle of the throttle valve axis, and wherein a rotary axis of a gear positioned in a middle of a torque transmission path between the rotary axis of the motor and the throttle valve axis is formed by a magnetic material.
[0037] In accordance with a sixth aspect of the present invention, there is provided a throttle valve control apparatus of an internal combustion engine structured such as to detect a rotational angle of a throttle valve driven by a motor,
wherein a magnet is mounted to the throttle valve axis; wherein hole elements are arranged at positions facing to each other with respect to the magnet and a stator corresponding to a magnetic path is attached between the hole elements, and wherein the motor is mounted to a position a uniform distance apart from the both hole elements.
[0041] In accordance with a seventh aspect of the present invention, there is provided a throttle valve control apparatus of an internal combustion engine structured such that a sensor for detecting a rotational angle of a throttle valve driven by a motor is provided and a rotary axis of the motor and the throttle valve axis are arranged in parallel,
wherein a magnet is mounted to the throttle valve axis, wherein hole elements are arranged at positions facing to each other with respect to the magnet and a stator corresponding to a magnetic path is attached between the hole elements, and wherein the both hole elements are arranged out of a circular arc having a radius corresponding to a distance between the rotary axis of the motor and a center of the throttle valve axis.
[0045] In accordance with an eighth aspect of the present invention, there is provided a throttle valve control apparatus of an internal combustion engine comprising:
a magnet mounted to a throttle valve axis to which a throttle valve is mounted; and a cover fixed to a throttle body so as to cover the magnet portion, wherein a hole element sensitive to a change of a magnetic physical amount of the magnet and a signal processing circuit converting an output of the hole element into a predetermined electric signal are mounted to the cover.
[0049] In accordance with a ninth aspect of the present invention, there is provided a throttle valve control apparatus of an internal combustion engine structured such that a rotary axis of a motor and a throttle valve axis are arranged in parallel and a rotation of the rotary axis of the motor is transmitted to the throttle valve axis via a reduction gear,
wherein a cover is mounted to a throttle body so as to cover the reduction gear, and wherein a magnetic type throttle sensor comprising a magnet and a hole element is mounted between an end surface of a gear fixed to the throttle valve axis and the cover so as to be capable of detecting a rotational angle of the throttle valve axis.
[0052] In accordance with a tenth aspect of the present invention, there is provided a throttle valve control apparatus of an internal combustion engine comprising:
a magnet mounted to an end portion of a throttle valve axis rotated by a motor; an element detecting a rotational angle of the throttle valve axis in cooperation with the magnet; and a spring holding the magnet at a predetermined opening position of opening degree when energizing of the motor is shut out, the spring being attached to a periphery of the throttle valve axis.
[0056] In accordance with an eleventh aspect of the present invention, there is provided a throttle valve control apparatus comprising:
a magnet mounted to a throttle valve axis rotated by a motor; an element detecting a rotational angle of the throttle valve axis in cooperation with the magnet; and the element being constituted by two components arranged under a magnetic influence of the magnet so as to be backed up by each other.
BRIEF DESCRIPTION OF THE DRAWINGS
[0060] FIG. 1 is a cross sectional view of a throttle valve control apparatus in accordance with an embodiment of the present invention;
[0061] FIG. 2 is another cross sectional view of a throttle valve control apparatus in accordance with an embodiment of the present invention;
[0062] FIG. 3 is an exploded perspective view of a throttle valve control apparatus in accordance with an embodiment of the present invention;
[0063] FIG. 4 is an exploded perspective view of a throttle valve control apparatus in accordance with an embodiment of the present invention as seen from another angle;
[0064] FIG. 5 is a view for explaining a feature of a structure of the embodiment;
[0065] FIG. 6 is a view showing a throttle valve axis assembly; and
[0066] FIGS. 7A and 7B are views for explaining a positional relation between a motion of a magnet and a hole element.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0067] A description will be given below of an embodiment in accordance with the present invention with reference to the accompanying drawings.
[0068] As shown in FIG. 1 , an electronic control type throttle valve apparatus (a throttle valve apparatus) is mainly constituted by a throttle body (hereinafter, which may be simply called as a body) 1 , a throttle valve 4 , a motor (a throttle valve drive apparatus; a motor-driven actuator) 22 for driving the throttle valve 4 , a reduction gear mechanism 100 , a sensor (a throttle sensor) 80 measuring an opening angle (an opening degree) of the throttle valve 4 , that is, a rotational angle of the throttle valve axis 3 , and a cover 16 protecting the throttle valve axis 3 , the motor 22 and the reduction gear mechanism 100 .
[0069] The body 1 is constituted by integrally forming a receiving portion (an intake bore) 2 of the throttle valve 4 and a receiving portion (a motor housing) 1 c of the motor 22 .
[0070] The throttle valve 4 is mounted to the throttle valve axis 3 by means of a screw 5 , and the axis 3 is supported by bearings 6 and 26 provided in the body 1 .
[0071] In accordance with the present embodiment, the bearing 6 is formed as a ball bearing, and the bearing 26 is formed as a cap-shaped plane bearing. The reason and details thereof will be described later. The ball bearing 6 is attached to a bearing boss 1 a via a seal ring 8 . Further, an inner ring 6 a of the ball bearing 6 is pressure inserted to an outer periphery of the throttle valve axis 3 , and an outer ring 6 b is transition fitted to an inner periphery of the bearing boss 1 a.
[0072] In the throttle valve axis 3 , only one end protrudes out of a side wall of the body 1 . Then, a spring 10 , a lever 9 , a spring 11 and a final stage gear (a driven gear) 12 of the reduction gear mechanism 100 are attached to one end of the throttle valve axis protruding out of the side wall.
[0073] Throttle valve relating parts (hereinafter, called as a throttle valve mechanism) such as the throttle valve axis 3 , the reduction gear mechanism 100 , the motor 22 and the like are received in a receiving portion (a case) 1 d formed on a side wall of the body 1 , and the receiving portion 1 d is covered by a synthetic resin cover 16 . The plane bearing 26 is attached in accordance with a pressure insertion.
[0074] That is, the throttle valve mechanism is arranged so as to be protected by one cover 16 , an opening (an opening for mounting the motor) 1 c′ of a motor housing 1 c is positioned so as to face within the receiving portion 1 d , the motor 22 is received in the housing through the opening, and an end bracket 22 a of the motor is fixed in the periphery of the opening 1 c′ by a screw 37 (refer to FIGS. 3 and 4 ).
[0075] A motor terminal 23 provided in the end bracket 22 a is positioned near one line of the side wall in the receiving portion 1 d , is arranged so as to be directed to the cover 16 side, and is connected to a relay terminal 24 a provided in the cover 16 side via a relay connector 33 . The relay connector 33 can employ various kinds of aspect. In the present embodiment, a sleeve made of a conductive material is used as the relay connector 33 , slits 34 and 35 having shifted directions at 90 degrees are provided in both ends thereof, and the relay terminal 24 a and the motor terminal 23 are inserted to the slit. The terminals 24 a and 23 also have shifted directions at 90 degrees in correspondence to the directions of the slits 34 and 35 .
[0076] The motor 22 is driven in response to an acceleration signal relating to a pedaling amount of an acceleration pedal, a traction signal, a uniform speed traveling signal, and an idle speed control signal, and a power of the motor 22 is transmitted to the throttle valve axis 3 via the reduction gear mechanism 100 (the motor pinion 21 , middle gears 20 and the final stage gear 12 ). The pinion 21 is mounted to a motor shaft 27 , and the middle gears 20 are freely fitted to a conductive shaft 19 adhered to the throttle body 1 . A gear 20 a having a larger diameter among the middle gears 20 is engaged with the pinion 21 and a gear 20 b having a smaller diameter is engaged with the gear 12 .
[0077] The final stage gear 12 is a fan-shaped gear as shown in FIGS. 3 and 4 .
[0078] A description will be given of a relation between the gear 12 and the lever 9 . The gear 12 has a hole 12 h for passing one end of the throttle valve axis 3 therethrough as shown in FIG. 3 , the hole 12 h is formed in a shape capable of engaging with one end 3 a (having at least two flat surfaces) of the throttle valve axis and is integrally rotated with the throttle valve axis.
[0079] The lever 9 is freely fitted to an outer periphery (a circumferential surface) of the throttle valve axis 3 , however, is engaged so as to be together attracted to the gear via the spring 11 . For example, a projection denotes by reference symbol 12 f in FIG. 4 is engaged with a projection (not shown) of the lever 9 . The projection 12 f is formed inside the gear 12 .
[0080] The spring 10 corresponds to a return spring for the throttle valve, one end thereof is engaged with a spring engaging portion (not shown) provided in the body 1 , and another end thereof is engaged with the lever 9 .
[0081] The spring 10 applies a return force to the throttle valve axis via the lever 9 and the gear 12 , and further, constitutes a so-called default opening degree setting mechanism which has been already known, in cooperation with the spring 11 and the lever 9 .
[0082] The default opening degree setting mechanism is structured such as to keep an initial opening degree of the throttle valve 4 at a time of turning off an engine key (in other words, at a time when the motor-driven actuator 22 is not energized) to a predetermined opening degree larger than a full close position.
[0083] Between the default opening degree position to a full open control position, the throttle valve opening degree is determined in correspondence with a balance between a torque of the motor 22 and a valve closing force of the spring (the return spring) 10 .
[0084] In the case of controlling so as to make the throttle valve opening degree smaller than the default opening degree, a motion of the lever 9 is restricted by a default opening degree stopper (not shown) and the control operation is performed by rotating only the gear 12 and the throttle valve axis 3 in a full closing direction against the force of the spring 11 .
[0085] A movable side stopper 12 d provided in one line of the fan-shaped gear 12 is brought into contact with a full close stopper (not shown) for restricting a mechanical full close position of the throttle valve, whereby a full close position is determined.
[0086] With respect to a material of the gear 12 in accordance with the present embodiment, a center portion thereof is formed by a metal plate 12 a , and a portion 12 b forming teeth and the other portions are integrally formed by a synthetic resin (a reinforced plastic).
[0087] In this case, the metal plate 12 a is insert molded to the resin portion of the gear 12 .
[0088] A side end of the gear 12 of the magnet 82 faces to the resin portion of the gear.
[0089] Accordingly, it is possible to prevent a magnetic flux of the magnet 82 from being leaked to the gear 12 .
[0090] The metal plate 12 a in a center portion of the gear 12 is pressed to the throttle body 1 a side by a magnet holder 81 , however, since the magnet holder 81 itself is made of a resin, the magnetic field is not leaked even if the magnet holder 81 is in contact with the metal plate 12 a.
[0091] The movable side stopper 12 d formed in one of cut end surfaces of the gear 12 is integrally connected to the metal plate 12 a.
[0092] The movable side stopper 12 d is made of a metal for the purpose of achieving an abrasion resistance, and an impact resistance. That is, mechanical full close position of the throttle valve becomes a reference point on control, and the stopper element 12 d is brought into contact with the full close stopper 25 in a fixed side at least one time at every operation starting times or operation finishing times. Accordingly, the movable side stopper 12 d is made of a metal so as to resist against a comparatively high collision frequency.
[0093] Reference symbol 12 i denotes a guide for engaging the gear 12 with the lever 9 .
[0094] The resin magnet holder 81 is pressure inserted and fixed to the front end of the throttle valve axis 3 , and the magnet 82 is integrally attached to the magnet holder 81 in accordance with a molding process.
[0095] An end portion of the magnet holder 81 presses the end surface of the gear 12 to a stepped portion 3 d side of the throttle shaft 3 , and commonly serves to prevent the gear 12 from being taken out.
[0096] A circuit board 84 of the throttle sensor 80 is fixed to a position opposing to the end portion of the throttle axis 3 on the inner surface of the cover 16 by a welding pin 86 .
[0097] A pair of semicircular stators 83 are fixed to the circuit board 84 so as to surround a periphery of the magnet 82 in such a manner as to face to each other with keeping a predetermined interval 87 . Reference numeral 85 denotes a guide of the stator 83 integrally provided in the circuit board 84 .
[0098] Hole elements 86 are mounted to a gap 87 portion between a pair of semicircular stators 83 .
[0099] Three terminals of the hole elements 86 are mechanically held to the circuit board 84 and are connected to a signal processing circuit such as an amplifier or an analogue/digital converter (not shown) arranged in the circuit board 84 .
[0100] The signal processing circuit arranged in the circuit board 84 is connected to a conductor 24 integrally molded with the cover 16 , and can transmit a signal to an external apparatus via an electric terminal 40 (connected to the conductor 24 ) of the connector 16 b integrally formed with the cover.
[0101] The hole element 86 detects a change of the magnetic field and generates a hole voltage when the throttle valve axis 3 rotates and the magnet 82 rotates.
[0102] The voltage is transmitted to the external circuit via the conductor 24 and the terminal 40 after being amplified by the amplifier or signal converted (including an amplification) by the analogue/digital converter.
[0103] An engine control unit (not shown) of a motor vehicle is provided with a coupler connected to the connector 16 b and a signal line, and the signal from the terminal 40 is input to the control unit.
[0104] The control unit corrects a fuel and an opening degree of a throttle valve corresponding to the control parameters and controls a speed change point of an automatic transmission, on the basis of a throttle opening degree and a vehicle speed detected in correspondence to a change of magnetic field corresponding to a magnetic physical amount of the magnet 82 .
[0105] Further, the spring 11 urges the gear 12 in a throttle valve opening direction so as to forcibly open the magnet 82 of the sensor to a predetermined opening degree position, when the energizing of the motor 12 is shut out.
[0106] Accordingly, in the motor vehicle provided with the throttle control apparatus in accordance with the present embodiment, the control parameters of the engine are adjusted in correspondence to the change of the electric signal which the hole element 86 outputs in connection with the opening degree of the throttle valve in response to the magnetic signal of the magnet mounted to the axial end of the throttle valve.
[0107] Since the sensor is a non-contact type, the opening signal of the throttle valve 4 corresponding to the change of the electric signal which the hole element 86 outputs is not exposed to a secular change so much, so the it is possible to accurately adjust the control parameters of the internal combustion engine for a long period.
[0108] A description will be given of a principle of the sensor with reference to FIG. 7 .
[0109] The magnet 82 corresponding to a rotor of the throttle sensor 80 is fixed to the magnet holder 81 in a state of facing a pair of arc-shaped magnets mutually having different polarities to each other.
[0110] When the magnet holder 81 is fixed to the throttle valve 3 and the throttle valve axis 3 is rotated, bonding surfaces of both of the magnets are relatively rotated with respect to the hole element. FIG. 7 shows a change of a magnetic line of force in this state.
[0111] A pair of hole elements 86 placed in the bonding surface portion of the magnetic pole output a signal forming a function of a rotational angle in response to the change of the magnetic line of force generated in correspondence to the change of the rotational angle of the throttle valve axis 3 .
[0112] Since the gear 12 is made of a synthetic resin, the magnetic field generated by the magnet 82 is not badly influenced by the gear 12 .
[0113] In the embodiment, the center portion fitted to the throttle valve axis 3 is made of a metal, however, a magnetic bad influence is further reduced by forming all the elements by a synthetic resin.
[0114] Since the magnetic field is not shifted even when the shape of the gear 12 is an irregular shape such as a fan shape, a sensitive characteristic of the hole element 86 can be uniformly obtained without relation to an angle of rotation of the throttle axis.
[0115] As shown in FIG. 5 , the hole element 86 is mounted in an outer portion of an area of a circular arc S drawn around a center of rotation of the motor by setting a size between a center of the rotary axis of the motor and a center of rotation of the throttle to a radius.
[0116] As a result, the hole element 86 is hard to be affected by an electromagnetic influence caused by a change of a drive current of the motor, and a detecting accuracy of the hole element 86 is hard to be deteriorated.
[0117] Since the structure is made such that the stator 83 is mounted to the circuit board 84 so as to be fixed to the inner surface of the cover 16 , an assembling operation of the stator 83 can be easily performed.
[0118] In this case, it is possible to directly fix the stator to the cover 16 .
[0119] In this case, the stator is fixed with shifting the control circuit from the stator, however, there is an advantage that a size in an axial direction can be shortened.
[0120] Since the rotational support axis 19 of the middle gear 20 positioned between the motor 22 and the magnetic type non-contact sensor 80 is made of a magnetic material, it is possible to expect an effect of shielding an electromagnetic influence caused by the change of the drive current of the motor 22 by the rotational support axis 19 , so that the hole element 86 is hard to be affected by the electromagnetic influence of the motor 22 , and a detecting accuracy of the hole element 86 is hard to be deteriorated.
[0121] As shown in FIG. 6 , since it is possible to assemble the throttle valve axis 3 , the springs 10 and 11 , the lever 9 , the final stage gear 12 , the magnet holder 81 and the magnet 82 to the throttle body 1 as a sub-assembly, an assembling operation can be easily performed.
[0122] In accordance with the present invention, it is possible to assemble the non-contact type sensor in the throttle body in a compact manner.
[0123] In accordance with another invention, it is possible to arrange the non-contact type throttle sensor between the cover of the throttle body and the gear in a compact manner.
[0124] Further, in accordance with the other invention, it is possible to assemble the non-contact type throttle sensor of the electromagnetic system in the throttle body by the structure which is hard to be affected by the electromagnetic noise.
[0125] Since it is possible to adjust the control parameters of the engine on the basis of the throttle opening degree signal which has a little secular change, a motor vehicle having a high control accuracy can be obtained. | The invention provides a throttle valve control apparatus provided with a throttle sensor which is in trouble at a low possibility and has a long service life, whereby an accurate output of a throttle opening degree can be obtained. The throttle valve control apparatus of an internal combustion engine ahs a throttle opening degree sensor constituted by a non-contact sensor using hole elements. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to furnace crucibles, and more particularly to the copper cooling blocks used behind refractory layers in the walls of the crucibles.
2. Description of Related Art
The high temperatures used in metal furnaces is enough to erode even brick-lined crucibles. Refractory materials are conventionally used to line the insides of crucibles, and the prior art has adopted the use of cooling blocks behind such linings. The operational result is a thin layer of the molten slag, matte and/or metal freezes on the walls and helps stabilize them against break-out. Such cooling blocks are also used for burner blocks, launders, tuyeres, staves, casting molds, electrode clamps, tap-hole blocks, and hearth anodes.
Most modern pyro-metallurgical furnaces use cooling systems to stabilize the unavoidable erosion of wall, roof and hearth refractories. Cooling blocks are typically arranged in a number of different ways. Walls, roofs and hearths that include them are used in cylindrical furnaces, oval furnaces, blast furnaces, Mitsubishi-style flash smelting and converting furnaces, IsaSmelt furnaces, electric arc furnaces, both AC and DC, basic oxygen furnaces, electric slag cleaning furnaces, rectangular furnaces, Outokumpu flash smelting and converting furnaces, Inco flash smelting furnaces, electric arc furnaces, slag cleaning furnaces, and reverbatory furnaces.
Cooling blocks can also be arranged in layers, with alternating courses of refractory. A refractory brick and/or castable refractory sometimes is used for the hot face of the block and may be smooth or have pockets and/or grooves machined or cast-in.
A problem develops when the cooling pipes and the metal castings are not the exact same materials. Different materials will have different coefficients of thermal expansion, and the strength of the bonding between the pipes and the castings will also vary. Constant thermal cycling can work the pipe loose of the casting, and when this happens the thermal efficiency drops significantly.
However, pipes made of materials with melting points that are higher than the molten casting metal are desirable because such resists softening or break-through during the casting pour. One prior art way to work around this problem is to tightly fill the pipes with sand so they are reinforced against collapse. Such sand is washed out after the casting has cooled.
Some combinations of cooling pipe and metal casting materials are known in the prior art as being able to provide at least an acceptable service life. For example, Falcon Foundry (Lowellville, Ohio) has produced Monel-400 pipes cast in copper cooling blocks since the 1960's. (Monel-400 is a trademark brand for an alloy of about 63% nickel and 31% copper.) Other companies, ElectroMelt (now defunct) and American Bridge (a former division of U.S. Steel), have designed cooling blocks utilizing Schedule-40 or Schedule-80 Monel-400 pipe coil assemblies which allow cooling chambers to be well defined. No cooling of the pipes is required during the casting pour of copper, as is normally the case with pure-copper pipes.
Unfortunately, failure analyses have shown that the copper cooling blocks are not in complete contact with the Monel-400 pipe. Many defects can be seen to exist when the blocks are destructively tested and the Monel-to-copper bond is evaluated. Such bonding defects reduce the thermal transfer efficiency and introduce unknowns into the overall furnace-cooling patterns.
Prior art cast copper and low-alloy-copper cooling blocks and design engineering have also been commercially supplied and/or designed by Hatch (Mississauga, Canada), Outokumpu OY (Finland), Kvaerner (Stockton, England), Demag (Germany), Hundt & Weber (Siegen, Germany), Tucson Foundry (Tucson, Ariz.), Thomas Begbie (South Africa), Alabama Copper (Alabama), Niagara Bronze (Niagara Falls, Canada), Hoogovens (Netherlands), and others.
Outokumpu, and others, design and manufacture copper cooling blocks from copper billet with longitudinal holes drilled for water passages. Extruded holes have also been used for the water passages, but some of these have been the subject of failures. Transverse drill holes with internal plugs have also been included to form internal cooling-water circuits.
The drilled and extruded designs all require plugs to be installed in all the open drill ends around the edges of the billet blocks. Solder, welded, and pipe-thread type plugs have all been tried. But many such blocks leak nonetheless, and such leaks are very dangerous in a metallurgical furnace.
The size and shape of such kinds of blocks is limited by the ability to cast or forge the copper billets. The internal water passage layout is often very constrained by having to fashion the passages from combinations of interconnected drill bores.
In contrast, cast blocks can be made in a wide variety of block shapes and sizes, and almost any layout is possible with the internal piping. Cast blocks can be used with much larger heat loads, compared to drilled and plugged blocks.
The fabrication of drilled blocks and cast blocks each present their own challenges. In casting, the water pipes can be both flow and pressure tested before and after. The danger of a leak through a copper cooling block with fabrication voids is very low because the pipe walls will contain the water.
Conventional cast cooling blocks are typically manufactured by forming a water pipe into a desired layout and pressure-testing it, before and after, to 150% of the design operating water pressure for at least fifteen minutes. Before the casting pour, the outside of the pipe is cleaned to minimize gas bubble formation that can result in porous casting sections at the pipe-coil and cast-copper interfaces. Sand is sometimes used to fill the inside of the pipes to stiffen them against softening, but only when using a pipe coil material that does not have a melting point significantly higher than the casting temperature of copper. For example, Monel-400 pipe does not ordinarily need to be packed with sand before casting.
The casting molds are made with extra allowances for machining off of porous sections, gates, risers, and shrinkage. Such molds are typically made from sand mixed with a bonding agent. The original shapes which are pressed in the sand are made from wood and other easily formed materials.
The pipe coils are securely located in the correct position inside the sand mold. Copper from a melting furnace is poured into a ladle. A de-oxidant may be necessary if the copper is melted in a non-inert environment. Any oxide slag is skimmed off. A sufficient superheat of the copper over its melting point is used to prevent the copper from prematurely solidifying during handling or pouring. The liquefied copper from the ladle must be sufficiently fluid to fill the mold, completely cover the pipe coils, and flow to the top of the risers. Any gas bubbles will rise high up to the surface of the risers.
Once the deoxidized copper is poured into the mold from the ladle, the casting is allowed to cool until it has totally solidified. The risers and gating systems are mechanically removed. Any excess material is machined or cut away, and hot-face grooves and/or pockets are formed or finished. On the outside surface, the holes are drilled and tapped for either locating, mounting or block lifting. The mating surfaces, between blocks, are normally machined. The amount of machining needed is dependent on the end use for the block.
Any surface imperfections may or may not be repaired, depending on the requirements of the end user. Such imperfections are ground out, weld filled, and machined smooth. The completed blocks are inspected using one or more inspection x-ray, visual inspection, infrared-thermal inspection, and hydrostatic or pneumatic pressure testing for leaks. Thermal and/or electrical testing is used to check that the block meets minimum thermal and electrical conductivity. Dimensional tolerances are also checked. Samples can be used in a destructive testing program, a predetermined percentage of the total number of identical or similar blocks to be manufactured are cut open and inspected.
Cooling blocks with steel and/or iron pipes and tubes cast inside copper have several advantages. The pipe coil is inexpensive and very easy to manufacture, bend, weld, and join with fittings. Steel and iron pipe coils do not melt when the molten copper is poured into the mold. The resulting blocks have well-defined water passages.
But the disadvantages include gas bubbles, porosity, gaps, and poor pipe-to-casting fusion. Such defects are detectable with x-ray and destructive testing. Cast copper does not form a good metallurgical bond with the outside of steel and iron pipes. Destructive testing shows such pipes separate easily from the cast copper. Samples are usually sliced up 0.25 to 1.00 inches thick to expose pipe cross sections. Cutting across through the slice so that the pipe is not mechanically locked in will usually confirm the poor steel-to-copper bond. Such pipes often fall out before a pneumatic chisel is applied.
Heat transfer from the copper to the pipe is reduced, due to lack of fusion and frequent defects at the pipe-copper interface. So the cooling block tends to run hotter than versions that use copper pipes. The much lower thermal conductivity of steel and iron in the pipe only exacerbates this inefficiency. The thermal conductivity of steel is about 33 BTU/hr/° F. compared to 226 BTU/hr/° F. for electrolytic copper, a seven-fold difference.
There are also large differences in the coefficients of thermal expansion between the steel in the pipes and the cast copper. Stresses at the pipe-copper interface easily exceed the copper yield-stress, so the copper in the block will crack under thermal cycling. The coefficients of thermal expansion are about 6.9×10 −6 in/in/° F. for steel, and 9.8×10 −6 in/in/° F. for UNS C81100 cast copper.
Stainless steel pipes or tubes with copper cast around them have more advantages. Stainless steel pipe coil is only slightly more expensive than steel or carbon pipe, and is about as easy to manufacture, bend, weld, and make fittings. The stainless steel pipe coil will not melt when molten copper is poured into a mold. The resulting block has a well-defined water passage. The disadvantages are less pronounced and less frequent, but gas bubbles, porosity, gaps and other signs of lack of fusion are common at the interface of the pipe with the copper.
Here too, the cast copper does not form a good metallurgical bond to the outside of the stainless steel pipe. Destructive tests prove the stainless steel pipe is also easily removed from the cast copper. The thermal conductivity of stainless steel is much worse than steel, e.g., only about 9.4 BTU/hr/° F. The coefficient of thermal expansion for stainless steel is about 9.6×10 −6 in/in/° F., compared to 9.8×10 −6 in/in/° F. for UNS C81100 cast copper.
Monel-400 pipe or tube when cast inside copper cooling blocks has the advantage that the Monel-400 will not melt when the molten copper is poured into the mold. So the resulting block will have a well-defined water passage. Molten copper wets Monel-400 very well. So the pipe coil and copper casting will form a tight intimate interface. However, Monel-400 pipe coil is the most expensive pipe coil commercially used with cast copper. It is much more difficult to manufacture.
Even so, the cast copper does not normally form a good metallurgical bond with the outside of the Monel-400 pipe. A pneumatic chisel can usually separate the two in destructive tests. Once separated, copper particles over the Monel-400 pipe cover less than 10% of the total surface area. At least 90% of the surface area of the typical Monel-400 pipe section is not bonded mechanically or metallurgically.
Cooling blocks made with Monel-400 pipe represent about 30% of the cost of the casting. Standard returns and fittings in Monel-400 are more difficult to obtain than their counterparts in stainless steel, carbon steel, or iron pipe. Some distortion of the Monel-400 pipe coil is typical during casting, but is not significant. Stiffening the Monel-400 pipe coil with a sand mixture is not usually needed. Gas bubbles, porosity, gaps and other signs of lack of fusion are not common at the interface of the pipe with the copper, provided adequate steps are taken for surface cleanliness of the pipe coil.
Heat transfer from the copper to the Monel-400 pipe is limited by the lack of metal fusion at the pipe-copper interface. The differences in the coefficients of thermal expansion are still too great between the Monel-400 pipe coil and the cast copper. The state of stress at the Monel-400 copper interface will exceed the yield stress of the copper, even at moderate thermal loads. Progressive failure will occur under thermal cycling. The coefficient of thermal expansion for Monel-400 is about 7.7×10 −6 in/in/° F., compared to 9.8×10 −6 in/in/° F. for UNS C81100 cast copper. Monel-400 pipe in cast copper cooling blocks can give good service in near steady-state operations.
Pure-copper pipe coil is less expensive than Monel-400, but more expensive than carbon steel or iron pipe. It is relatively easy to manufacture, bend, weld, etc. The resulting cooling block has a well-defined water passage, and considerable bonding of the cast copper to the copper pipe can occur.
The resulting copper cooling block tends to run the coolest of all, provided that the cast copper has bonded to the outside of the pure-copper pipe coil. The interface of the pipe coil with the cast copper is quite good, the prior art does not ordinarily obtain such metallugical bonding.
But the pure-copper pipe coil will soften or melt if used in large castings. The pipe coil must be cooled during the casting pour when fabricating moderate to large size blocks. A melt-through of the pipe is a strong possibility, particularly at any corners. Uneven cooling during casting and the thinner walls on the outsides of the pipe bends contribute to melt-through. The pure-copper pipe coil must have much thicker walls than any other type of pipe coil. The equivalent of a Schedule-120 or Schedule-160 is normally used, compared to Schedule-40 or less for the other pipe coil types.
An adverse consequence of the thicker walls is the center-to-center spacing of water passages must be much larger. The surface area of water within the block will be reduced. The equilibrium heat removal capacity is diminished compared to Monel-400 and steel alloy pipe materials. The amount of cooling required during casting is based on considerable foundry experience.
Gas bubbles, porosity, gaps, and other signs of a lack of metal fusion can still occur at the interface of the pipe with the copper, but to a much lesser extent than with either steel or iron pipes. If too much cooling of the pipes during the casting pour is used, a good metallurgical bond to the outside of the pipe will not occur. But if too little cooling is used, a melt-through can occur in the walls of the copper pipe. Such melt-throughs can obstruct the cooling water flow, and the cooling block will be unusable. If the molten copper melts through the pipe and contacts the cooling medium during the casting pour, a dangerous explosion can occur.
Pure-copper pipe in cast-copper cooling blocks provides good service for moderate and cyclic thermal loading, but only if the block is well made.
Sand cores can be used instead of pipe to define water passages within a copper casting, e.g., the way automobile engine blocks are made. The sand is blended with an organic binder, and the technique is much less expensive than using internal preformed metal pipe coils. The resulting blocks can have well-defined water passages, and the sand is easily removed after the casting has solidified. The cooling water is in intimate contact with the cast copper cooling block, and this maximizes heat transfer.
But parts of the sand may dislodge during casting and ruin the water containment. The design of the water passages is much less flexible than with preformed pipe coils because the sand cores must be mechanically supported. Extensive foundry experience is required to make such castings. Gas bubbles, porosity, gaps and fusion defects can occur. The inside of the water passages are not as smooth as with pipes, and this leads to higher hydraulic gradients. Larger supply pumps and piping are often needed. The reject rate of cast blocks with sand cores is higher than those with pipes having high melting point materials.
The lack of an internal pipe coil increases the risk of a potential leak. Steel vent/support pipes for the sand cores must be sealed using a plug and/or welding. The casting will fill with gas bubbles if there are no vents. The support pipes are necessary, as the sand cores would sag otherwise. These steel pipes can also be a source of porosity, or through-thickness defects.
The sand-core cast copper cooling blocks tend to run the coolest of all types. Such provide good service for moderate and cyclic thermal loading, provided that the block is well made.
A typical cooling block comprises steel or copper water pipe filled with sand and cast inside a block of steel or copper. For example, U.S. Pat. No. 5,904,893, issued May 18, 1999, to Ulrich Stein, describes a plate cooler for iron and steel industry metallurgical furnaces, blast furnaces, direct reduction reactors, and gassing units with refractory linings. A pattern of thick-walled copper pipes is arranged inside a mold, and molten copper is poured into the mold. The use of a few different copper alloys are also discussed. Intimate bonding of the cast copper block to the cooling pipe is needed to maintain the thermal efficiency of the cooling block. A slight melting of the thick-walled pipes is said to occur during the pouring of the molten copper around the pipeline, and thus bonds them in the casting.
An Aug. 13, 1974, U.S. Pat. No. 3,829,595, by Nanjyo, et al., illustrates a cross-section of an electric direct-arc furnace with cooling blocks in the walls. This and all other Patents mentioned herein are incorporated by reference. The cooling blocks are described as specially cast steel with steel water-cooling tubes. Refractory brick is locked in horizontal grooves cut in the hot faces of the cooling blocks to mechanically stabilize them and improve heat transfer.
A shaft furnace cooling plate is described by Axel Kubbutat, et al., in U.S. Pat. No. 5,676,908, issued Oct. 14, 1997. Such cooling plate is used behind a refractory lining and is described as an improvement over prior art devices made of cast iron. It also criticizes cast copper cooling plates as having a lesser ability to conduct heat compared to denser forged or rolled stock copper. So a furnace-cooling plate is taught with reinforced head ends that are integrated into the cooling system.
Ulrich Stein describes a plate cooler in U.S. Pat. No. 5,904,893, issued May 18, 1999. Cast copper is used with a low-alloy copper. Both webbed/grooved and smooth surfaced cooling plates are mentioned. The fact that pure copper pipes are being used causes Ulrich Stein to caution that pipes with walls thicker than are commercially available must be used. Column 3, line 65, to column 4, line 3. About 1-5 mm of the pipe walls melt after the casting pour.
A typical casting pour will overfill the mold so that impurities will float off. A porous top layer that forms, can be milled away down to the final dimensions needed. The pipe cast inside is pressure-tested before and after. A typical cooling block can weigh as little as two pounds to as much as several tons, depending on the furnace application.
What is needed is a cooling block that can be made from readily obtainable and relatively inexpensive commercial materials, and yet achieves strong fusion between the piping and the casting. The differential coefficient of expansion must also be such that high heat loads and constant thermal cycling can be tolerated over the operational lifetime without cracking or other materials failures.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a cooling block that can tolerate high heat loads and constant thermal cycling over its operational lifetime.
Another object of the present invention is to provide a cooling block that can be manufactured from readily obtainable and relatively inexpensive commercial materials.
A further object of the present invention is to provide a cooling block in which the internal piping can assume tight smooth bends without resorting to reversing caps, internal plugs, elbows, or other fittings with sharp corners that can fail during casting.
Briefly, a furnace-cooling block embodiment of the present invention comprises a UNS-type C71500 Schedule-40 water pipe-cast inside a pour of electrolytic copper UNS-type C11000 de-oxidized during the casting process to produce a high-copper approximating UNS-type 81200. A resulting fusion of the pipe to the casting is such that the differential coefficient of expansions of the two copper alloys involved does not exceed the yield strength of the casting copper during operational thermal cycling. The melting point of the copper alloy used in the pipe is such that a relatively thin-wall pipe may be used with a sand packing during the melt.
An advantage of the present invention is that a furnace-cooling block is provided that has a low thermal resistance between the hot face and cooling water circulating during operation in the piping.
Another advantage of the present invention is that a furnace-cooling block is provided that can be used in high heat load and thermal cycling applications.
A still further advantage of the present invention is that a furnace-cooling block is provided that is inexpensive to manufacture.
The above and still further objects, features, and advantages of the present invention will become apparent upon consideration of the following detailed description of specific embodiments thereof, especially when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A, 1 B and 1 C are end, top, and side projections of a furnace-cooling system embodiment of the present invention;
FIG. 2 is a plan view diagram of a pipe loop like that used in the furnace-cooling system of FIGS. 1A-1C;
FIG. 3 is a copper-nickel phase diagram, and shows that UNS-type C71500 alloy will begin to melt at about 1125° C. (2150° F.); and
FIGS. 4A, 4 B, 4 C and 4 D are top, longitudinal cross-section, bottom, and lateral cross-section diagrams of a cooling block embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1A-1C represent a furnace-cooling system embodiment of the present invention, and is referred to herein by the general reference numeral 100 . The furnace-cooling system 100 comprises a pipe 102 bent into a loop and cast inside a cooling block 104 . A pair of flanges 106 and 108 allow for mounting of the furnace-cooling system 100 in a foundry furnace crucible. A conical hole 110 provides a secure way to mount a refractory casting or brick that lines the inner walls of such crucibles. A pair of pipe fittings 112 and 114 provide connections for a water-cooling circulation system.
The pipe 102 preferably comprises UNS-type C71500 copper-nickel alloy and is filled with sand to prevent collapse during casting of the block 104 . (The UNS-type C71500 copper-nickel alloy is also called number-715 by the Copper Development Association.) The cooling block is preferably cast with UNS-type C11000 electrolytic copper which is de-oxidized during the casting process. That ultimately produces a casting with a high-copper alloy equivalent to UNS-type 81200. In alternative embodiments, a casting with a high-copper alloy equivalent to UNS-type 81100 is produced.
FIG. 2 illustrates a pipe loop 200 of UNS-type C71500 copper-nickel alloy before it is cast inside a cooling block. Such is degreased and deoxidized thoroughly before the casting operation to ensure good fusion and bonding. Pure copper melts at about 1980° F. and ordinarily requires preheating when welding, so it may be advantageous to preheat the pipe loop 200 just before it is cast inside the block. Preheating also helps to evaporate water moisture from both the mold and the pipe coil.
FIG. 2 shows a pipe loop 200 made of one piece of smooth-wall pipe bent to the desired shape. If the required pattern was not possible to construct that way, then pipe fittings would be needed. Such fittings must be welded-on with any sharp edges ground down. Otherwise, the joints will collect occlusions in the casting or act to generate voids.
In destructive tests that were conducted on a prototype of the furnace-cooling system 100 , the block 104 was cut to expose about 25% of the pipe coil 102 circumference and sliced into a five-eighths inch long piece. A pneumatic chisel was used in an attempt to dislodge the pipe from the copper. The pipe remained fused to the cast copper. In previous attempts with the prior art devices using other nickel-copper alloys or Monel-400 for the pipe coil, it was often possible to dislodge the pipe coil segment from the cast copper with no more than the chisel.
A scanning electron microscope (SEM) used at the Cominco Research facility in Trail, British Columbia, Canada, found that grains of the cast copper were metallurgically bonded to the pipe copper. Such welding prevented the UNS-type C71500 copper-nickel alloy pipe from being dislodged from the cast copper. Such a good metallurgical bond is not normally observed in any prior art coil materials, e.g., copper pipe, Monel-400 pipe, etc.
The approximate composition of UNS-type C71500 is given in Table I.
TABLE I
material
Ni
Pb
Fe
Zn
Mn
Cu
W %
29.0-33.0
0.05
0.4-0.7
1.0
1.0
remainder
Even though UNS-type C71500 copper alloy is less likely to be contaminated by handling and storage than Monel-400, the same precautions and cleaning procedures conventional for Monel-400 are preferably used in making embodiments of the present invention. For example, the pipe must not be handled with bare hands and should be laid on cardboard. Monel-400 tends to pick-up iron very easily. Contaminants left on the pipe during casting will convert to gases that result after solidification in porosity in the copper casting.
FIG. 3 is a copper-nickel phase diagram, and shows that UNS-type C71500 alloy will begin to melt at about 1125° C. (2150° F.). The melting point of Monel-400 is only slightly higher than that. So good interface fusion is obtained without much in the way of a sacrifice in the melting point.
In embodiments of the present invention, the usual stresses at the interface of the pipe with the cast copper do not exceed the yield stress for the cast copper, based on three-dimensional finite element thermo-mechanical stress analyses. Cyclic loading applications are, therefore, permissible. The coefficient of thermal expansion for UNS-type C71500 copper-nickel alloy is about 9.0×10 −6 in/in/° F., and 9.8×10 −6 in/in/° F. for UNS C81100 cast copper. The differential is, therefore, only 0.8×10 −6 in/in/° F. The yield strength of cast copper is about 9.0 ksi, and 30-40 ksi for Monel-400.
ASTM Schedule-40 pipe, or thinner, can therefore be used for the UNS-type C71500 copper-nickel alloy pipe coils. Tighter water passage spacing is possible. The commercial cost is less than Monel-400 pipe. The finished copper casting will run cooler due to the higher thermal conductivity of the new alloy compared to Monel-400.
The lower melting temperature of UNS-type C71500 copper-nickel alloy, compared to Monel-400, means the preformed pipe coils must be packed with a mixture of sand mix and organic binder to stiffen the pipes during the casting process. However, cooling is critically not required. If the pipe coils are-not stiffened with sand, they will either sag or sections will bend and move too close the hot face of the block. Either occurrence can render the cooling block unusable. The sand mix is removed after the casting has solidified.
In general, embodiments of the present invention strike a balance between the differential melting points, and the differential coefficients of expansion of the pipe and casting materials. High differential melting points are needed so the pipe does not melt or soften during casting, and so thin-wall pipes can be used that can be formed easily. But low differential coefficients of expansion of the pipe and casting materials are needed so that the yield strengths of the materials are not exceeded during operational thermal cycling. Copper alloys are, in general, preferred for the pipe and casting materials because of their superior thermal conductivity compared to material cost.
Therefore, the respective copper-alloys used in the pipe and casting must be sufficiently different to result in a maximal differential melting point, and sufficiently the same to result in a minimal differential coefficient of expansion. Given these general constraints, an empirical solution has been to make embodiments of the present invention with UNS-type C71500 copper-nickel alloy, and the casting with UNS C81100 cast copper. The thermal conductivity of the copper predominates, and the yield strength at the fused interface are not over-stressed by operational thermal cycling. Other UNS-type alloy combinations could no doubt be satisfactory, but these will all necessarily meet the general constraints mentioned herein.
The yield strengths of the pipe and casting both degrade as the copper content of the respective alloys increases. For example, the maximum copper casting stress at the pipe interface is almost linearly proportional from 8000 PSI at 30%-W copper to 2000 PSI at 100%-W copper. The maximum pipe stress is almost linearly proportional from 14000 PSI at 30%-W copper to 2000 PSI at 100%-W copper.
TABLE II
Cu % - W
A
B
C
D
E
F
100
135
114
325
2228
2228
2 Grooves
70
158
115
349
5662
8195
2 Grooves
30
161
115
352
8303
14203
2 Grooves
70
158
115
229
5642
8166
Pockets
For an applied heat flux of 50,000 BTU/Ft 2 /hr:
A = pipe temperature ° F., external;
B = pipe temperature ° F., internal;
C = copper temperature ° F., tip;
D = copper stress (PSI), at pipe;
E = pipe stress (PSI);
F = surface type.
FIGS. 4A-4D illustrate a cooling block embodiment of the present invention, and is referred to herein by the general reference numeral 400 . The cooling block 400 includes a hot-face 402 opposite to a plumbing face 404 . A pair of UNS C71500 copper-nickel alloy pipes 406 and 407 are fitted with respective pipe couplings 408 - 411 . The pipes 406 and 407 are cast inside a solid-copper block 412 . FIGS. 4A-4D show a typical pattern. A system of vertical grooves 414 , horizontal grooves 416 , and pockets 418 at the intersections are included in the hot face 402 . Such provide sites to retain refractory and/or frozen bath material. The use of any of the vertical grooves 414 , horizontal grooves 416 , and pockets 418 , as well as their shapes and placement are a matter of engineering choice made for each particular application. The fabrication of the cooling block 400 is similar to the furnace-cooling system 100 of FIG. 1 .
Although particular embodiments of the present invention have been described and illustrated, such is not intended to limit the invention. Modifications and changes will no doubt become apparent to those skilled in the art, and it is intended that the invention only be limited by the scope of the appended claims. | A furnace-cooling block comprises a UNS-type C71500 schedule-40 water pipe cast inside a pour of electrolytic copper UNS-type C11000 de-oxidized during the casting process, or melted in an inert environment, to produce a high-copper approximating UNS-type C81100. A resulting fusion of the pipe to the casting is such that the differential coefficient of expansions of the two copper alloys involved does not exceed the yield strength of the casting copper during operational thermal cycling. The melting point of the copper alloy used in the pipe is such that a relatively thin-wall pipe may be used with a sand packing during the melt. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates generally to a sample gathering apparatus, and more particularly to an apparatus for drivably moving a core sampling assembly into and out of subterranean zones for the gathering of core samples. The apparatus of the present invention is particularly adapted for use in the gathering of peat samples from peatlands.
Peat has become regarded as a more valuable resource in recent times. It is an organic residue originating under more or less water-saturated conditions in the earth's crust, with the material being formed generally through incomplete decomposition of plant and animal constituents. The incomplete decomposition of the plant and animal constituents occurs because of anaerobic conditions in the presence of low temperatures, and possibly from other complex causes. The origin of peat is defined in a work by M. L. Heinselman, "Forest Sites, Bog Processes and Peatland Types in the Glacial Lake Agassiz Region". Peat is, at the present time, recognized as a multi-use resource which includes use of this material as a source of energy, as well as for use in the garden market to improve the conditions of the soil.
In order to determine the nature and quality of the peatland, core samples are gathered so as to conduct determinations upon the sample such as determining water content, pH, bulk density, BTU values, percent of volatiles present, fixed carbon content, ash content, total sulfur content, as well as heavy metal content. Certain types of peat, particularly those found in areas within and adjacent the State of Minnesota have been found to be best for energy output, and as such, may have significant value in the conversion of the peat into synthetic natural gas.
Because of the nature of the areas in which peat occurs, it is frequently difficult to move heavy equipment into the peatland or peat bog area. All-terrain vehicles are able to traverse the surface of peat bog areas, and when these vehicles are not heavily loaded, they will normally ride along the surface of the bog. The apparatus of the present invention is of sufficiently lightweight so as to permit mounting upon all-terrain vehicles, hence making it possible to quickly and efficiently gather core samples to determine the value of the peat contained within the immediate peatland area. In addition to its lightweight, the apparatus is designed so as to permit vertical stroke movement of substantial depth, with the apparatus including generally an assembly to which additional lengths of rod may be added to extend the depth of the probe.
While a number of core sampling receptacles are available and in use today, one such device which has been found to be of particular use in the sampling of peat is known as the "Macaulay" type. The Macaulay type core sampling receptacle is generally an elongated tubular structure containing a stabilizing fin which will permit the device to be forced downwardly into the peatland, and thereafter articulated so as to close a semi-circular cylindrical wall about a zone of undisturbed peat. Other types of core sampling receptacles may be employed if desired, such as the Shelby type device. In order to achieve the articulation necessary for the semi-circular cylindrical segment, means are appropriately provided in the drive mechanism to permit arcuate rotation to occur.
SUMMARY OF THE INVENTION
Briefly, in accordance with the present invention, a sample gathering apparatus is provided which includes an elongated frame means along with drive means mounted thereupon for moving the core sampling assembly into and out of subterranean zones. Coupling means are provided for releasably securing the drive means to the core sampling assembly. The frame means is provided with a first pivotal joint for adjustably mounting the sample gathering apparatus upon a vehicle, such as a self-propelled all-terrain vehicle. The coupling means which secures the drive means to the core sampling assembly is pivotally secured to an endless belt drive arrangement and is arranged to permit pivotal motion of the core sampling assembly about a generally horizontal axis. The frame means and the first pivotal joint are provided in order to permit the core sampling assembly to be properly aligned and arranged in plumb disposition prior to the time that the core sampling assembly enters the earth.
Therefore, it is a primary object of the present invention to provide an improved core sampling apparatus which is designed for mounting upon a self-propelled vehicle, and which is designed to permit vertical movement of the core sampling assembly into the earth, and pivotal movement of the core sampling assembly about a horizontal axis when removed from the earth.
It is a further object of the present invention to provide an improved sample gathering apparatus, specifically a core sampling apparatus which is arranged to drivably move a core sampling assembly into and out of subterranean zones for gathering core samples therewithin, the arrangement including motor means for drivably moving the core sampling assembly into the earth, and further providing for means to expeditiously remove the core sample from the sampling receptacle upon removal from the earth.
Other and further objects of the present invention will become apparent to those skilled in the art upon a study of the following specification, appended claims, and accompanying drawings.
IN THE DRAWINGS
FIG. 1 is a side elevational view of the sample gathering apparatus of the present invention, with the apparatus being mounted upon a self-propelled all-terrain vehicle, and being disposed in transport disposition;
FIG. 2 is a view similar to FIG. 1, wherein the sample gathering apparatus is arranged in core sampling disposition;
FIG. 3 is a rear elevational view of the sample gathering apparatus, and illustrating the structure in the same disposition as is illustrated in FIG. 2;
FIG. 4 is a side elevational view, on a slightly enlarged scale, of the sample gathering apparatus, and illustrating the manner in which the motor is mounted upon and secured to the frame;
FIG. 4A is a horizontal sectional view taken along the line and in the direction of the arrows 4A--4A of FIG. 4;
FIG. 5 is a rear elevational view of the sample gathering apparatus of the present invention, and being drawn to the same scale as FIG. 4, and illustrating the manner in which the drive means is mounted within the frame means;
FIG. 6 is a vertical sectional view taken along the line and in the direction of the arrows 6--6 of FIG. 4, with FIG. 6 being illustrated on a slightly enlarged scale; and
FIG. 7 is a vertical sectional view taken along the line and in the direction of the arrows 7--7 of FIG. 5, with FIG. 7 being likewise shown on a slightly enlarged scale.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In accordance with the preferred embodiment of the present invention, and with particular attention being directed to FIGS. 1-3 of the drawings, the sample gathering apparatus generally designated 10 is shown as being mounted upon a self-propelled all-terrain vehicle 11, with the vehicle being provided with structural frame members 12--12 to which the sample gathering apparatus 10 is secured. As is typical of self-propelled all-terrain vehicles, the vehicle is provided with an engine (not shown) which drives endless tracks 13--13 by means of drive sprocket 14 and a number of idler sprockets 15--15. Self-propelled all-terrain vehicles are readily commercially available.
As has been indicated, self-propelled all-terrain vehicles are particularly adapted for use in peatland areas, since they are generally of sufficiently lightweight so as to be supported by the surface, and thus render it possible for the users to drive into and around the peatland area including bogs.
With attention now being directed to FIGS. 4, 4A, and 5 of the drawings, the sample gathering apparatus generally designated 10 includes frame means 16 which, for the most part, includes a pair of side channels 18 and 19, and upper and lower end plates 20 and 21 respectively. As is apparent in the drawings, the lower plate 21 is arranged in oppositely disposed position from upper plate 20, this disposition being desirable and required in order to permit pivotal motion of the core sampling assembly about a horizontal axis, as will be more fully explained hereinafter.
Drive means are provided, and mounted upon the frame 16, with the drive means including a motor 23 which is drivably coupled to gear box 24, with gear box 24 being, in turn, drivably coupled to clutch unit 25. The motor 23 is preferably a commercially available winch motor, these winch motors normally being provided with winch gear boxes. It is appreciated that these devices and structures are widely available commercially and need no further explanation here since they are well known and recognized to those skilled in the art. The clutch assembly shown at 25 is designed to deliver the proper and desired amount of torque to the drive system, with the torque setting of the clutch being adjusted to provide a drive force to the core sampling assembly which is just sufficient to provide modest lifting of the rear portion of the self-propelled all-terrain vehicle 11.
Clutch 25 is coupled directly to drive shaft 27, with drive sprockets 28 and 29 being fast upon shaft 27. Shaft 27, as shown, is journaled in bearing assemblies such as at 30, with a corresponding and mating bearing assembly being provided at the opposed end of shaft 27, but being concealed in the view of FIG. 6. Sprockets 28 and 29 are in mesh with endless belts 32 and 33, with the term "endless belt" being used in a comprehensive sense, since elements 32 and 33 are actually endless drive chains. Chains 32 and 33 are, in turn, trained over idler sprockets 34 and 35, with these idler sprockets being fast on shafts 36 and 37 respectively. Shafts 36 and 37 are stub shafts which are, in turn, journaled for rotation within bearing blocks 38 and 39. The reason stub shafts are used is to permit swingable pivotal motion of the core sampling assembly about a horizontal axis, and furthermore, the use of stub shafts in this area minimizes the size and hence the weight of the overall structure.
With attention continuing to be directed to FIGS. 6 and 7, a drive assembly is shown generally at 41, with the assembly including a pair of side plates 42 and 43 which are secured together by suitable means, such as tie rod 44. Between side panels 42 and 43, there is positioned a core sample assembly receiving hub 45. A bore is formed centrally of receiving hub 45, as at 46, with this bore being designed to receive a portion of the core sample assembly therewithin, as will be more fully described hereinafter. Receiving hub 45 is provided with a pair of side trunnions 48 and 49, the trunnions being received within bearings 50 and 51, and hence arranged for journaled rotation therewithin. As is indicated in FIG. 7, a pair of spaced apart bores are formed within hub 45 as at 53 and 54, with the bores 53 and 54 being arranged to receive pin means such as pin 55 for coupling receiving hub 45 to an extension member of the core sampling assembly as will be described more fully hereinafter. Specifically, the core sampling assembly which is shown generally at 56 includes a Macaulay type sampling head 57 to which is secured an adaptor segment 58 and one or more extension segments 59. The sampling head 57 along with adaptor 58 and extensions 59 make up what is defined as the core sampling receptacle assembly. Pin 55 is arranged to engage adaptor 58 coaxially, so as to assure positive and plumb driving. Adaptor 58 and extensions 59 are each provided with spaced apart transverse bores, with these bores being arranged to receive pins such as pin 55 therethrough. While being driven downwardly into the earth, it has been found desirable to provide pin 55 engaged in the lower bore, such as bore 54, while during withdrawal, it is preferable to have the pin such as pin 55 in the upper bore. The disposition in the upper bore is illustrated in FIG. 7. The reason for the dual disposition is due to the fact that the pin has been found to be more readily released from the coupling disposition during a driving sequence when it is disposed in the bottom bore, and in turn, more readily released from the top bore during withdrawal.
Attention is now re-directed to FIGS. 4A and 6 of the drawings wherein the details of hub 60 are shown. Specifically, hub 60 is in the form of a spool having a hollow core therewithin, and with the hollow core receiving shaft 27 so as to render hub 60 freely rotatable thereon. Hub 60 is in the form of a cradle, and is designed to assist in initial guiding of the sampler head 57 as it is first driven into the surface of the earth. As can be appreciated, hub or cradle 60 is designed and positioned so as to provide a guiding arcuate surface as at 61 which is useful in assuring that the core sampling assembly is plumb when it enters the earth's surface.
In a typical sampling operation, the operator arrives at the sampling site and levels the apparatus from side-to-side. The frame means is erected and is adjustably positioned so as to be arranged vertically and plumb. For assisting in this leveling operation, an adjustable bifurcated clamp is provided as at 63, into which there is fitted the bracket and clamping bolt assembly 64, as is illustrated in FIGS. 4A and 5. Thereafter, sampler head 57 and adaptor 58 are secured to hub 45, and, normally, a first length of extension 59 is secured to the end of adaptor 58. Normally, conventional drill rod is employed for each extension rod such as extension 59, with drill rod being available commercially and in desired lengths. For most core sampling operations, core samples of one meter in length are obtained on each sampling operation, and hence a graduated scale of one meter or multiples thereof are normally desired for lengths of extension rods such as extension rod 59. As has been indicated, the locking pin such as pin 55 is secured in hub 45 and through core sampling assembly (adaptor 58) in the lower bore 54. The operator then determines that the core sampling assembly is in level and plumb disposition, and further checks the disposition of the sampler 57 relative to the surfaces of hub cradle 60.
The operation is then commenced with the winch motor 23 being activated to deliver power to endless belts or chains 32 and 33, and thus drive sampler 57 and the remaining portions of the core sampling assembly downwardly. As indicated, the downward distance is one meter, and when this depth has been achieved, the sampler is articulated so as to capture the sample desired. In a Macaulay type sampler, the external sheath such as is illustrated at 65 is rotated arcuately 180°, thereby capturing the sample disposed at that location. Thereafter, pin 55 is removed, and placed in the upper bore of hub 45, at which time the core sampling assembly is removed from the earth. Upon being fully removed or extracted from the sample bore, the operator tilts sampler 57 upwardly about the axis formed by trunnions 48 and 49, and thus is able to remove the sample at a convenient location, and with the sampler head being arranged in horizontal disposition. The horizontal disposition for the sampler head is important in order to preserve all of the entrained water, thus rendering it possible to achieve a more accurate analysis of the sample obtained. Upon removal of the sample from the head 57, the pin 55 is returned to the lower position, that is within bore 54, and the operation is re-started.
As has been indicated, the operation of the device is simple and straightforward, and provides a desired mechanism for gathering samples of undisturbed earth, and specifically undisturbed peat. The apparatus of the present invention is fully capable of use to core sample depths of 50 feet or more, with such a depth of deposit being occasionally found in North America. | Sample gathering apparatus for drivably moving a core sampling assembly into and out of subterranean zones for gathering core samples therewithin, with the apparatus including an elongated frame means which is adapted for adjustable pivotal mounting upon a supporting vehicle. Drive means are provided for delivering power to the core sampling assembly, and coupling means are further provided for releasably securing the drive means to the core sampling assembly. The core sampling assembly is arranged to be driven vertically into the subterranean zones to be sampled, and the coupling means which releasably secures the drive means to the core sampling assembly permits pivotal motion of the core sampling assembly about a generally horizontal axis so as to permit pivotal lifting of the core sampling assembly from the ground surface for easy removal of the sample retained therewithin. | 4 |
This is a division of application Ser. No. 600,893, filed Apr. 16, 1984.
BACKGROUND OF THE INVENTION
This invention relates generally to repair of sewer lines, and more particularly to simple and effective apparatus and method to inexpensively repair such lines.
In the past, fracturing of clay pipe lines necessitated digging up the line along its length, removing the old pipe, installing new pipe, and filling in the dirt and repairing the overlying road surface. This was a very expensive operation, and one that hardly warranted such expense and effort where the clay pipe line was fractured in only a few places.
SUMMARY OF THE INVENTION
It is a major object of the invention to provide method and apparatus to repair such lines without digging up the line, thus saving great expense and effort.
Basically, the method employs a liner sleeve and elastomer sleeve extending about the liner sleeve, and a filler slurry, and includes the steps:
(a) installing the liner sleeve and said elastomer sleeve end wise in the sewer line to locate the two sleeves in bridging relation with the fracture, and
(b) displacing slurry into a space formed between the two sleeves to cause the elastomeric sleeve to expand and seal against the sewer line in bridging relation with the fracture.
The slurry is typically displaced radially through the liner sleeve into the space between the sleeves and via a fixture which is releasably attached to the liner sleeve to travel therewith in the sewer line, the fixture being detachable from the liner sleeve and recoverable after slurry displacement is accomplished.
Further, a drag system may be employed to drag the two sleeves endwise in the sewer line to the fracture location, and the drag system may then be released for recovery thereof. The positioning of the drag cable may be correlated to the position of a scanning camera used to preliminarily locate the fracture, whereby the position of the fracture may be accurately determined so that the elastomer sleeve may accurately bridge the fracture.
These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following description and drawings, in which:
DRAWING DESCRIPTION
FIG. 1 is a vertical elevation, in section, showing details of installation of a liner and elastomer sleeve unit;
FIG. 2 is an enlarged elevation, in section, showing details of a puller unit;
FIG. 3 is an enlarged vertical elevation showing details of a fluid connector releasably attached to a liner and sleeve unit;
FIG. 4 is a section, in elevation, on lines 4--4 of FIG. 3;
FIG. 5 is a fragmentary plan view on lines 5--5 of FIG. 3;
FIG. 6 is an enlarged vertical elevation showing sealing off of a fracture in a clay pipe line, employing the liner and sleeve unit;
FIG. 7 is an enlarged fragmentary section showing a flow smoothing ring on the liner and sleeve unit;
FIG. 8 is an enlarged fragmentary section showing end-to-end interconnection of two liner and sleeve units; and
FIG. 9 is a view like FIG. 6, showing application to a branching clay pipe line.
DETAILED DESCRIPTION
Referring first to FIG. 1, sewer line 10 has clay pipes 11 laid end-to-end, under the ground surface 12. When one or more of the pipes develops a fracture, as at 13, the problem of how to economically repair the line is presented.
In accordance with the invention, a liner and elastomer sleeve "pig" unit 14 is employed, and is introduced underground, or via first manhole 15, well 16, and the clay pipe line, to be traveled endwise therein to the location of the fracture. See FIG. 1, showing a puller cable 17. The latter is first introduced downwardly in well 16, through the pipe line 10, and run up second well 16a through manhole 15a to winch 18 on a vehicle or truck 19. As winch 18 is rotated by motor and drive 21, the cable 17 is pulled endwise, to pull unit 14 underground and along the pipe line to the location of the fracture. That location may first be determined as by a television camera 22 advanced endwise by the cable in line 10. Idler drums 23-26 and associated frames 23a-26a may first be installed in and above the wells 16 and 16a, as shown, so that the unit 14 may be pulled endwise down well 16, around drum 24, and endwise in the pipe line 10, and so that the cable will travel in the same manner, as well as up well 16a, around drum 26, and onto the winch 18. The length of the cable 17 extended when camera 22 locates the fracture may be noted and used to subsequently register the unit 14 across the fracture.
The unit 14 may be attached to the cable as by a tubular container shell 28 closely fitting endwise within the bore 29a of a liner sleeve 29 of unit 14 (see FIG. 2). The wall 28a of shell 28 is shown as of bellows shape, to expand and grip bore 29a in response to air pressurization of the shell interior 28b, air supplied via hoses 30 and 30a extending from a surface pressure source 31, and controlled by valve 32. When the valve 32 is closed, pressurization of bellows wall 28a ceases, and cable 17 and container 28 may be pulled free of the installed unit 14, as by operation of winch 18. A snap release connection of the air hose 30a to container wall 28a is shown at 33.
The unit 14 also includes an elastomer sleeve 34 attached to and extending about the liner sleeve 29, as for example as shown in FIGS. 1 and 6. Metallic bands 35 and 36 at opposite ends of the unit 14 annularly hold the ends of the elastomer sleeve tightly and sealingly against the circular surface of the lower sleeve, and in travel mode, the elastomer sleeve 34 fits closely about a cylindrical surface 29b of sleeve 29, between the bands.
FIG. 6 shows the unit having arrived at the fracture in the clay pipe sewer line. It is brought into bridging relation with the fracture, as shown. At that point, slurry 37 is displaced into a space between the sleeves and under pressure, to cause the sleeve 34 to expand outwardly and seal against the bore 11a of the sewer line pipe that is fractured, to establish an annular seal against the bore and bridging the fracture. Thereafter, the liquid contents of the line flow through the liner piper 29, which becomes anchored to the sewer line due to the liner 34 expanding into the fracture and held there by hardening of the slurry 37 in the space 38. Typical slurries include resin which polymerizes in situ in space 38, as for example epoxy resins, and grout, and a catalyst if required.
FIGS. 3-6 show means for feeding slurry and grout components in two lines or hoses 40 and 41, and a catalyst in hose 42, extending from the surface to the unit 14. These components are fed together or blended in a mixer fitting 43 (see FIG. 5), and then fed in a bore 44 upwardly at 44a and through an attachment fitting 45 into space 38. Fitting 45 may be a grease type fitting thread connected to the wall of liner 29, as at 46. See also surface control valves 40a 41a and 42a.
Mixture fitting 43 is releasably connected to wall fitting 45, so that fitting 43 can be removed, i.e. pulled free of the unit 14, after slurry delivery to space 38. As shown, the duct 44a is within a short stroke plunger 50 urged upwardly by air pressure to grip the lower end 45a of the fitting 45, as during travel of unit 14 into FIG. 6 position, and during delivery of slurry components into space 38. Such air pressure, delivered by hose 30, is exerted upwardly against a piston 51 slidable in cylinder 52, and connected to plunger 50. At such times as disconnection and retrieval of the fitting 43 and associated apparatus is desired, the air pressure is shut off, as by closure of the valve 32, which causes the plunger 50 to release from the fitting 45. The fitting 43 may then be pulled leftwardly in FIG. 3, so that the fixture 45 lower end flange 45b slides out of a slot 54 in fixture 43, the latter then being pulled out of the sewer by operation of winch 55 reeling the hoses 30, and 40-42.
FIG. 7 shows an elastomer or rubber ring 56 attached to the forward traveling end of the unit 14, and having a flaring bore 56a, to cause sewer liquids to flow into the interior 14c of unit 14, as unit 14 travels rightwardly in FIG. 7. Note that the annular outer edge 56b of ring 56 travels closely adjacent the bore 11a of the sewer line clay pipe 11.
FIG. 8 shows the use of an elastomer annulus 59 fitting over the end of one unit 14d and over the end of a previously installed unit 14e to establish a seal therebetween. When unit 14d is pulled toward and endwise against unit 14e, the annulus 59, installed on either unit, fits over the other unit.
FIG. 9 shows a modified unit 14f, like unit 14, but having a side opening 60 to register with a branch passage 61 in a clay pipe 62. | The repair of a sewer line having a fracture, and employing a liner sleeve and an elastomer sleeve extending about the line sleeve, and a filler slurry, includes:
(a) installing the liner sleeve and the elastomer sleeve endwise in the sewer line to locate the two sleeves in bridging relation with the fracture, and
(b) displacing slurry into a space formed between the two sleeves to cause the elastomeric sleeve to expand and seal against the sewer line in bridging relation with the fracture. | 5 |
BACKGROUND OF THE INVENTION
This invention concerns the locking of "automatic" pipework joints, i.e., in which a male end is inserted into a socket while radially compressing a sealing gasket housed therein. In this case, water-tightness is achieved independently from the locking, which is intended solely to avoid the dislocation of the joints when the pipes carry highly pressurized fluids.
However, the invention may also be applicable to the locking of "mechanical" joints, i.e., in which water-tightness is obtained simultaneously with the locking by the axial compression of a sealing gasket.
SUMMARY OF THE INVENTION
An object of the invention is to provide a reliable and economical locking device for pipe joints. To this end, the invention provides a flange for joints mounted between pipework components and designed to be installed on the end contour of one of the components having a mating or complementary shape, and to act as a support for a joint-locking device, the flange having, over at least one portion of its periphery, a radial L-shaped cross-section, the concavity defined by the arms of the L being directed radially inwardly.
According to other features of the invention the respective arms of the L are positioned radially and parallel to the axis of the flange, which has an inclined support surface on a convex side thereof, such inclined support surface extending toward the flange axis until it reaches a position opposite the radial or vertical arm of the L, and the vertical arm of the L ending in an interior cylindrical surface.
Another object of the invention is to provide a pipework assembly comprising at least one pipework component fitted with an end contour, at least one mounted flange such as the one described above and whose internal shape mates with the external shape of the contour, and at least one locking device adapted to rest on the flange. The end contour may define a socket, and the assembly may additionally comprise a sealing gasket installed in the socket, and a male end of a second pipework component inserted in the socket while compressing the sealing gasket radially, such male end bearing support means cooperable with the locking device.
In one embodiment the support means comprises a retaining ring fitted over the male end and a weld seam formed thereon and/or the sealing gasket may be of the locking-insert type.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal cross-section of one half of a substantially symmetrical pipework assembly according to the invention,
FIG. 2 is a top view of a free-standing flange of the FIG. 1 assembly,
FIG. 3 is a front view of a variant of the flange, and
FIG. 4 illustrates another variant of the flange according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a locked automatic joint produced between a socket 1 forming the end contour of a first pipework component A, which is, for example, a connecting sleeve or a pipe, and the male end 2, having a cylindrical exterior surface, of a second pipework component B formed by a pipe. Components A and B are made, for example, of cast-iron and produced by centrifuging. The joint further comprises a radial-compression sealing gasket 3, a mounted flange 4, a locking device 5, and support means 6 by which the device 5 rests on the male end.
The socket 1 comprises, internally, a housing 7 for the sealing gasket 3 and is delimited at its outer end by an internal radial wall 8. The latter defines an inlet opening 9 which allows the male end 2 to be inserted, while maintaining appreciable radial play, into the socket in order to radially compress the sealing gasket 3, thus ensuring the water-tightness of the joint. The wall 8 also defines a flat end section 10 of the socket.
Externally the socket has, in succession and beginning at the end section 10, a large diameter cylindrical surface 11, a radial surface 12, a smaller diameter cylindrical surface 13, a bend 14 extending toward the joint axis, and a curved surface 15 whose diameter decreases progressively.
The flange 4 is a slotted ring whose radial cross-section is uniform and visible in FIG. 1. This cross-section has an overall L shape, comprising one arm 16 parallel to the joint axis and a radial arm 17. The flange thus defines, internally, a large diameter cylindrical surface 18, a radial surface 19, and a smaller diameter cylindrical surface 20, these three surfaces forming an S which mates with the S formed by surfaces 11 to 13 of the socket. The front part of the flange is delimited by a flat end section 21 connected to the surface 18, and the exterior of the flange is delimited by a cylindrical surface 22 continuing from the surface 21 and by a tapered rear surface 23 extending from surface 22 to surface 20. The edges between surfaces 18 and 21, 21 and 22, 22 and 23, and 23 and 20 are rounded.
As shown in FIG. 2, an axial pin 24 is attached to each end of the flange 4, on its rear surface. When the flange is placed on the socket i in the manner of a circlip, these two pins are connected by a tie piece such as an elastic band (not shown).
The locking device 5 comprises an annular collar 25, made of one or several parts, which has a spherical interior surface 26, and a series of support elements 27, each of which passes through an axial opening 28 provided on the periphery of the collar. Each element 27 comprises a shaft whose one end is fitted with an eccentric flange 29, and whose other end 30 is threaded to receive a nut (not shown). The collar 25 has a flat end section 31 on the side facing the socket 1.
The support means 6 comprise, first, a circular weld seam 32 made of one or several parts, laid down on the male end 2 and positioned on the outside of the socket when the joint is assembled, and second, a slotted retaining ring 33 fitted over the male end. This retaining ring comprises, on the side facing the socket, a flat surface 34 resting on the weld seam 32, and, on the other side, a spherical surface 35 which mates with the under surface 26 of the collar 25.
To produce the locked joint shown in FIG. 1, the locking device 5 and the retaining ring 33 are first fitted on the male end beyond the weld seam 32, and the flange 4 is positioned on the socket, thereby setting the surface 21 of the flange back from the end section 10 of the socket. Next, the male end is inserted in the socket, so that the two pipework components assume their final positions.
To lock the joint thus produced, the support elements 27 are inserted through the openings 28 after they have been turned 90° in relation to the position illustrated in FIG. I, thereby allowing the flanges 29 to pass over the flange 4.
Next, the elements 27 are turned 90° to bring them into their locking position, as shown. The nuts are then screwed on the threads 30 thereby bringing the inclined support surface of each flange 29 into contact with the mating surface 23 of the flange 4 over the entire axial length thereof, the surface 26 of the collar 25 being simultaneously brought into a resting position against the surface 35, and the surface 34 of the retaining ring 33 being brought, in addition, into a resting position against the weld seam 32. This ensures the locking of the joint and prevents its dislocation under the effect of the axial stresses generated when the pipes carry a pressurized fluid.
The use of the mounted flange 4 has several advantages, to wit:
a) the socket 1 is less solid and bulky than it would be if it had to integrally embody the support surface 23 by itself, thus reducing shrink hole problems in the cast-iron during centrifuging,
b) because of the shape of the flange 4 as described above, locking stress is effectively transmitted to the socket without any risk of rocking the flange,
c) the most suitable material may be chosen for the flange, for example cast-iron, steel, or even, for moderate pressures, a plastic, which thus provides electrical insulation of the successive pipe lengths, and
d) identical pipework components A may be manufactured to form the joints intended to be locked and those not intended to be locked. Substantial savings of cast-iron may thus be made for all production operations.
As a variant, as illustrated in FIG. 3, the flange 4A may be formed from two halves, each of which is fitted, at each end, with a pin 24, these pins being connected in pairs, for example by means of an elastic band, when the flange is put in place on the socket. This variant is suitable, in particular, for small-diameter pipes, i.e., diameters of less than 200 mm.
As a further variant (FIG. 4), the flange may be formed from a number of sectors 4B connected by flexible elements 4C, such as rubber connection pieces.
The sealing gasket 3 may be of the locking-insert type, for example that described in commonly assigned French patent No. 2,621,376. | To lock a pipework joint in place, a locking device 5 rests on a flange 4 mounted on the socket end of one of the pipes. The flange has, over at least one portion of its periphery, a radial L-shaped cross-section, the concavity of the L being oriented radially inwardly and mating with a complementary contour on the end of the socket. | 5 |
TECHNICAL FIELD
The technical field relates to insertion, positioning, and securing of a magnet in an implanted part of a cochlear implant and an associated tool for its removal.
BACKGROUND
Cochlear implants typically include an external device that is coupled to an implanted device. The coupling may be achieved through electromagnetic coupling, where coils transmit and/or receive information and/or energy. Consequently, external and internal devices each utilize a coil to transmit and to receive information and/or energy. The external device includes at least one coil and the internal device includes at least one coil.
In order to align the coils of the external device and the internal device with respect to each other, one or more magnets are associated each coil. Thus, the two coils are aligned and the external device is pulled toward the implanted device by the magnets. The external device is thus held in the proper working position on top of the implanted device by magnetic force.
The magnet of the implanted device may be encapsulated in a biocompatible housing to ensure compatibility with the body of the user in case the magnet is made of magnetic material that is itself not biocompatible. As shown is FIG. 1A , generally the magnet 13 is mounted into a small hermetical part that is made of silicone, because silicone is biocompatible. To position this magnet under the skin in the correct position, the magnet 13 is inserted into a hole included in the silicone part 14 , in the center of the coil 12 .
As shown on FIG. 1B , in a different design, fixed magnet 104 is permanently installed into the hermetic housing 101 made of ceramic 105 and titanium 106 , in the center of coil 103 . Fixed magnet 104 is considered to be non-removable due to the way it is installed in the hermetic housing 101 .
Most of the time, cochlear implants are compatible with low power magnetic resonance imaging (MRI) up to magnetic field strength of 1.5 tesla (T). At levels up to 1.5 T an implant is generally secure, minimal heat is generated, the magnetic characteristics of the implanted magnet remain stable, any artifact effects in the MRI are acceptable, and the implanted device is not displaced.
However, when higher power MRI has to be performed on patients wearing a cochlear implant, some problems can occur, including demagnetization of the implanted magnet, strong force applied to tissues due to the magnetic field of the MRI interacting with the internal magnet, heat generation, and undesirable artifacts in the MRI results.
To address these concerns, some cochlear implants are designed to enable removal magnets while the cochlear implant remains implanted in the user. The removal of the implanted magnet enables the use of high power MRI. As shown in FIG. 1C , a magnet 503 is placed in the center of silicone molding 504 , where silicone lips 507 partially cover the top of the magnet 503 . A central hole and slots 508 between silicone lips 507 enable the removal of the magnet by deforming the silicone lips 507 when force is applied to the magnet 503 .
While the design in FIG. 1C enables removal of the magnet 503 , the design does not provide sufficiently high stability for the magnet 503 when it is installed in the cochlear implant due to the elasticity of silicone. Further, when the magnet 503 is removed and replaced, it may be misaligned and have a secondary displacement due to torque. Furthermore, the design provides no specific solution to make the handling and removal of the magnet 503 easy for the healthcare provider.
From EP2119474A2 it is known to provide the magnet in a releasable manner placed in a hole centered in a circular ceramic housing. The ceramic housing thus encircles the magnet. The document does not provide information on measures to facilitate the fast removal and replacement of the magnet.
SUMMARY
The solution proposed in the disclosure resolves shortcomings noted above by providing a stable mounting solution for a magnet and a tool for its removal. Further, the solution is minimally invasive using a compact structure. The proposed solution takes into account specific tooling needed by a surgeon in order to grasp and remove a magnet from the surrounding housing.
In an embodiment, a cochlear implant system includes a subcutaneous housing containing electronics for at least stimulation or collection of data and at least one antenna for communicating with an external device. The subcutaneous housing includes a main body having a U-shaped radial cross-section, a bottom cover secured to the main body, forming a hollow cavity bounded by an inner surface of the main body and the bottom cover, and a central cavity in a center of the subcutaneous housing formed by a portion of an outer surface of the main body. A magnet is removably inserted into the central cavity, the magnet including a cylindrical body with a central axis, the central axis aligned with a removal axis of the central cavity, a groove extending circumferentially around the cylindrical body, and a top surface. The top surface includes an outer edge, a plurality of ribs extending radially farther than the outer edge, and a plurality of abutments extending radially farther than the ribs. Further, a compressive ring is seated in the groove of the cylindrical body, wherein the compressive ring engages under a ledge in the central cavity when the magnet is inserted into the central cavity and biases the magnet against removal from the central cavity.
In an embodiment, the cochlear implant system further includes a silicone rim surrounding the body and tapering radially outward.
In an embodiment, the silicone rim includes two flaps extending outward, each flap including a support ring configured to accept a bone anchoring screw.
In an embodiment, the cochlear implant system further includes a junction area formed as a part of the silicone rim between the two flaps, the junction area accommodating electrodes passing to the cochlear implant.
In an embodiment, the bottom cover is a stamped titanium cover.
In an embodiment, the stamped titanium cover includes a plurality of feedthroughs.
In an embodiment, the main body is made of a biocompatible ceramic material.
In an embodiment, the biocompatible material is one of zirconia toughened alumina, high purity alumina, and pure zirconia.
In an embodiment, the top surface of the magnet includes three ribs and three abutments equally spaced around the outer circumference of the outer edge of the top surface, the abutments are in contact with a rim of the central cavity when the magnet is fully inserted into the central cavity, and the ribs are not in contact with the rim of the central cavity.
In an embodiment, each rib has a smoothly tapered edge connected to the outer edge of the top surface, and a void is bounded by the outer edge of the top surface and the rim of the central cavity.
In an embodiment, the cochlear implant system further includes a tool for removing the magnet from the central cavity, the tool including a handle portion, a second magnet installed on a first end of the handle portion, three blades extending from the first end parallel to a central axis of the handle portion, each blade terminating with a hook, wherein each blade is insertable in the void, each hook engages under a respective rib when the handle portion is rotated after insertion of the blades, and the second magnet attracts the magnet in the central cavity when the hooks engage under the ribs.
In an embodiment, the magnet includes an outer casing made of a biocompatible material, and a magnetic core.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1A illustrates a top and a side view of a cochlear implant housing according to background art.
FIG. 1B illustrates a partial cross section view of a cochlear implant composed of a hermetic housing with a non-removable magnet according to background art.
FIG. 1C illustrates a top view of a cochlear implant housing according to background art.
FIGS. 2A and 2B illustrate a front view and a cross section view of an example of a cochlear implant with a removable magnet according to an embodiment of the disclosure.
FIG. 2C illustrates a top view and a cross sectional view of an example of a removable magnet assembly according to an embodiment of the disclosure.
FIG. 2D illustrates a further top view and cross sectional view of a further example of the dislosure.
FIG. 3A illustrates a perspective view of an example of cochlear implant with its magnet removed with a tool according to an embodiment of the disclosure.
FIG. 3B illustrates a detailed perspective view of an example of cochlear implant with its magnet removed from its place according to an embodiment of the disclosure.
FIG. 3C illustrates various stages of interaction between removal tool and magnet.
FIG. 4 shows an exploded view of a magnet and magnet holder according to the disclosure.
FIG. 5A is a plane view of a further embodiment of the disclosure.
FIG. 5B is a plane view of yet another embodiment of the disclosure.
FIG. 6A discloses a further embodiment of the disclosure in two plane views.
FIG. 6B is a cross sectional view of the embodiment of FIG. 6A .
FIG. 6C is a cross sectional view of the housing belonging to the embodiment of FIG. 6A and 6B .
DETAILED DESCRIPTION
Embodiments of the present disclosure retain a cochlear implant magnet securely positioned in the center of the cochlear implant housing while maintaining a very compact structure. At the same time, the electronics and the coil of the cochlear implant are hermetically isolated. An interface between the magnet assembly and the cochlear housing has been designed to provide excellent alignment of the magnet within the cochlear implant housing. The interface also enables easy and safe removal of the magnet when needed.
FIGS. 2A-B illustrate an example of a cochlear implant with a subcutaneous housing 201 which has a compact structure and houses electronics 202 and one or more coils 203 for receiving and transmitting information and energy. Also feedthroughs (not shown) for connecting electrodes to the subcutaneous housing are part of the construction. Such electrodes can stimulate or measure electrophysiological signals in the patient's body. In other situations, the electrical connections to/from the inside of the housing may also or alternatively connect an electromechanical actuator such as vibrator for bone conduction or for stimulating the middle ear.
A magnet 205 is installed removably in a central cavity 230 of housing 201 . The central cavity 230 is in the center of the annulus formed by the housing 201 . The magnet 205 creates a magnetic field that holds and centers an external device that includes one or more coils. The external device can thus communicate with the implanted cochlear implant or supply energy to the cochlear implant.
The subcutaneous housing 201 may include a silicone rim 206 to provide a soft and ergonomic shape that helps preserve surrounding patient tissues when the cochlear implant is surgically implanted. The continuation of the silicone rim 206 forms two flaps 207 . Flaps 207 each include a reinforcing ring 208 . The rings 208 can be made of biocompatible material such as titanium, PEEK or PEKK, in order to allow the implant to be fixed onto the temporal bone of a patient. The implant can be fastened to the skull bone with screws that pass through rings 208 .
An area between reinforcing rings 208 forms a junction 220 . The junction 220 can house or accommodate electrodes passing to feedthroughs from an external device.
The main housing 201 is composed of a main body having a U-shaped cross sectional profile, referred to as U-shaped main body 210 . The U-shaped main body 210 forms a cavity which hermetically accommodates electronics 202 and coil 203 . The U-shaped main body 210 can be made of biocompatible ceramic such as zirconia toughened alumina, high purity alumina, or pure zirconia. A stamped titanium cover 211 is attached to the rim of the U-shaped main body 210 by laser welding to form a hermetically sealed cavity.
Magnet 205 is guided directly by U-shaped main body 210 through a precisely sized diameter of central cavity 230 . The precise sizing of the diameter reduces free movement of the magnet 205 to only a rotation about removal axis 212 or a translation in the direction of the removal axis 212 . No pitching or tilting of magnet 205 relative to housing 201 is possible when the magnet is fully installed in the central cavity 230 . Removal axis 212 passes through the center of the central cavity 230 and is perpendicular to the plane of the top surface of main body 210 .
The magnet 205 is preferably biocompatible. Thus, the magnet 205 may be constructed as a magnetic core 240 surrounded by a biocompatible housing 245 . The biocompatible housing 245 thus forms the outer surface of the magnet 205 and may be made of titanium.
As illustrated in FIG. 2C , the body of magnet 205 is radially symmetrical except for a portion at the top surface 223 of the magnet 205 . The top of the magnet 205 has an outer edge 218 which is radially surpassed by raised ribs 214 and abutments 215 . FIG. 2C illustrates an example with three ribs 214 and three abutments 215 .
Abutments 215 extend radially farther out beyond the edge of the ribs 214 . The abutments 215 prevent the magnet 205 from passing completely through the central cavity 230 of the housing 201 , and in case of shock or impact directly on the removable magnet 205 , energy will be dissipated to the housing 201 and will not impact the patient's temporal bone by the small surface 216 of the removable magnet 205 , but by the entire surface 217 of the implant housing 212 .
While abutments 215 are in contact with the rim of the central cavity 230 , the ribs 214 are sized smaller than the abutments 215 , so there is a gap 306 between the edge of ribs 214 and the rim of the central cavity. This gap 306 allows the insertion of a tool 303 to remove the magnet 205 as described below. The ribs 214 have a smooth transition 219 from the edge 218 , facilitating the rotation of tool 303 after it is inserted.
Magnet 205 includes a silicone ring 213 that is calibrated to withstand a force induced by RMI of up to 3T. The silicone ring 213 is placed in a radial groove 235 in the body of magnet 205 . When the magnet 205 is inserted into central cavity 230 , the silicone ring 213 exerts force on both the magnet 205 and the inner walls of central cavity 230 to hold the magnet 205 securely in place. As shown in FIG. 2B , the side profile of central cavity 230 has a ledge 236 under which silicone ring 213 is engaged, thus biasing the magnet 205 against removal from the central cavity 230 .
As shown in FIG. 3A , magnet 205 can be removed from the housing 302 with removal tool 303 . It may sometimes be necessary to remove the magnet 205 , such as when a very high level of MRI (e.g., above 3T) is needed.
When the magnet is to be removed, a surgeon can make an incision above the magnet and lift the skin away from the magnet area. A tool 303 can then be inserted through the incision and used to remove the magnet 205 . As shown in detail in FIG. 3B , the tool 303 has its own magnet 304 placed at the proximal edge of the tool in order to automatically align the tool 303 on the magnet 205 . As seen in FIG. 3C the surgeon has to insert the number of blades 305 at the proximal edge of the tool 303 into the gaps 306 defined between the outer edge of the magnet 218 and the rim of the central cavity 230 . This position is seen in the middle part of FIG. 3C . Then, the tool 303 is turned counter-clockwise enough to lock the blades 305 under the ribs 214 via hooks 310 . This final position is shown in the left hand view of FIG. 3C . In this position a secure engagement between tool and magnet has been established, and the tool and magnet may be lifted out of cavity 230 without further ado. As the surgeon exerts force on the magnet, the supporting force from the silicone ring 213 , which holds the magnet 205 in the cavity 230 , is overcome and the magnet is removed. The embedded magnet 304 holds the magnet 205 at the proximal edge of the tool 303 even after the magnet 205 is removed. The magnet 205 can be easily removed from the tool by hand if need be, and be dealt with in the usual flow of contaminated elements of the hospital.
A new sterile magnet 205 may be put in place by hand, without using a tool. It is preferable to rinse and dry the central cavity 230 before installing the new magnet 205 . As the surgeon presses the new magnet 205 into cavity 230 , compression strength of the silicone ring 213 on the new magnet 205 is overcome, and the magnet 205 slides securely into its correct position.
FIG. 4 discloses an exploded view of the magnet and its enclosure. The enclosure comprises a biocompatible housing 245 shaped as a bucket with an outwardly directed upper rim comprising the outer edge 218 , raised ribs 214 and abutments 215 . A lid 246 is provided and secured to the biocompatible housing 245 in a top recess 442 , and in FIG. 2D a weld line 243 is indicated for the fusing of lid 246 and biocompatible housing 245 . Other ways of fusing the lid to the housing could be used such as gluing or brazing. The various raised ribs 214 and abutments 215 are in the disclosed embodiment made as part of the housing 245 , but the skilled person would know, that there are many other options, such as providing these structural details as part of the lid.
FIGS. 5A and 5B discloses embodiments with two or four abutments 215 respectively dispersed evenly around the circumference of the magnet 205 and a commensurate number of ribs 214 .
In FIG. 6A , B and C a further embodiment is shown wherein the silicone ring 213 is provided as part of the implant, and the magnet 205 simply comprises the groove 235 . When the magnet is lifted out of the implant the silicone ring 213 stays with the implant. This is advantageus from a hygienic point of view, as the intersection between silicone ring and magnet groove will not lend itself as a hiding place for infecting agents during or after autoclaving.
While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
List of Elements
Number Element
12 coil 13 magnet 14 silicone part 101 hermetic housing 103 coil 104 fixed magnet 105 ceramic 106 titanium 201 subcutaneous housing 202 electronics 203 coil(s) 204 feedthroughs 205 magnet 206 silicone rim 207 flaps 208 ring 209 axis 210 U-shaped main body 211 stamped titanium cover 212 removal axis 213 silicone ring 214 rib 215 abutment 216 bottom surface of magnet 217 surface of housing 218 outer edge of magnet top 219 transistion 220 junction 223 top surface of magnet 230 central cavity 235 groove 236 ledge 240 magnetic core 242 top recess 243 weldline 245 biocompatible housing 246 lid 303 removal tool 304 magnet in tool 305 blade 306 gap(s) 310 hook 503 magnet 504 silicone molding 507 silicone lips 508 slots | A cochlear implant system includes a subcutaneous housing which includes a main body and a bottom cover secured to the main body. A central cavity in a center of the subcutaneous housing is formed by a portion of an outer surface of the main body. A magnet is removably inserted into the central cavity and includes a cylindrical body with a central axis aligned with a removal axis of the central cavity, a groove extending circumferentially around the cylindrical body, and a top surface, which includes an outer edge, a plurality of ribs extending radially farther than the outer edge, and a plurality of abutments extending radially farther than the ribs. A compressive ring is seated in the groove of the cylindrical body and engages under a ledge in the central cavity when the magnet is inserted into the central cavity and biases the magnet against removal from the central cavity. | 0 |
This application is a divisional of co-pending U.S. patent application Ser. No. 13/727,155 filed Dec. 26, 2012, which claims priority to provisional application No. 61/580,584 filed Dec. 27, 2011, the disclosures of which are incorporated herein by reference in their entirety.
BACKGROUND
The present disclosure relates to the field of agricultural implements drawn by motive power sources such as tractors and used for planting. More particularly, the present disclosure relates to a paddle sealer having closing wheels for closing seed trenches in a manner to promote uniform germination and emergence.
In damp soil conditions, conventional closing wheels commonly found on seeding equipment can compact the soil used to close the seed trench. This can result in undesirable effects. Excessive soil compaction impedes root growth and therefore limits the amount of soil explored by roots. This, in turn, can decrease the plant's ability to take up nutrients and water. From the standpoint of crop production, the adverse effect of soil compaction on water flow and storage may be more serious than the direct effect of soil compaction on root growth.
In dry years, soil compaction can lead to stunted, drought stressed plants due to decreased root growth. Without timely rains and well-placed fertilizers, yield reductions will occur. Soil compaction in wet years decreases soil aeration. This results in increased denitrification (loss of nitrate-nitrogen to the atmosphere). There can also be a soil compaction induced nitrogen and potassium deficiency. Plants need to spend energy to take up potassium. Reduced soil aeration affects root metabolism. There can also be increased risk of crop disease. All of these factors result in added stress to the crop and, ultimately, yield loss.
In the farming practice of strip till, a berm of soil is created by a specially designed fertilizer knife injecting soil additive and a pair of angled sealing discs. The most common used soil additive is anhydrous ammonia (NH3), a nitrogen fertilizer. NH3 rapidly turns from a liquid state to a gas during the application process and must be sealed before it reaches the soil surface. The conventional method used to seal NH3 is by relocating soil on top of the berm using a pair of concave sealing discs. This method does not adequately seal in the NH3 and escape of the NH3 occurs. In addition, soil clods are commonly relocated to the top of the berm. The drawback to this method is that an inconsistent berm height is created by the clods, which traps air and impedes settling of the soil in the berm. Strip till is normally practiced in the fall, giving the soil time to settle before seeds are planted into the berm the following spring. Any trapped air in the berm during planting can impact seed germination, as well as seed depth. If soil settling occurs after planting, the depth of the seeds will vary, which could have a negative effect on emergence.
SUMMARY
In accordance with the present disclosure, a paddle sealer having closing wheels is provided to be drawn by a motive power source such as a tractor and used to close seed trenches to prevent the seed trench from reopening and provide the proper soil conditioning to promote uniform germination and emergence.
In accordance with the present disclosure, a paddle sealer is intended to finely chop and churn soil such that loose soil will trap and seal in applied fertilizer, such as anhydrous ammonia, and/or to reduce soil clods and air pockets. The finely churned soil rapidly settles back into a soil trench created by a fertilizer applicator knife (that runs in front of the paddle sealer or is utilized preceding the paddle sealer). The paddle sealer of the present disclosure paddles and churns the soil on the sides and top of the berm into finer particles.
In illustrative embodiments, the paddle sealer with closing wheels includes an adjustable frame structure including a tensioned arm assembly and an attachment mechanism for attaching the paddle sealer to seeding equipment, and a paddle closing wheel assembly carried by the arm assembly.
In some embodiments, the paddle closing wheel includes a planar body portion provided with a series of radially extending fingers about its periphery. The closing wheels also include a series of paddles attached to the fingers of the closing wheel, which are used to churn the soil into a finer texture. The finer soil particles better close the seed trench and prevent air pockets in the seed trench. Air pockets in the seed trench negatively effect germination which reduces the yield potential of the emerging crop. Also, the need to run drag chains to help close the trench is reduced. The closing wheels also minimize soil compaction, which reduces crop issues.
Additional features of the disclosure will become apparent to those skilled in the art upon consideration of the following detailed description of illustrative embodiments exemplifying the best mode of carrying out the disclosure as presently perceived.
BRIEF DESCRIPTION OF THE DRAWINGS
The detailed description particularly refers to the accompanying figures in which:
FIG. 1 is an illustration of a seed trench that was not properly closed over a seed, creating poor seed to soil contact;
FIG. 2 is an illustration of a seed trench that cracked open to expose a seed, which dries out and does not germinate;
FIG. 3 is an illustration of a seed trench with a gap above the seed, which causes the seed to leaf out, preventing the plant from penetrating the soil;
FIG. 4 is a perspective view of a pair of paddle closing wheels rotatably mounted to an adjustable frame structure of a planting unit, showing the paddle closure wheels having a toe-in orientation (at an angle to a vertical axis) and having a positive camber orientation (at an angle with respect to a longitudinal axis);
FIG. 5 is an exploded view of the adjustable frame structure of FIG. 4 ;
FIG. 6 is an exploded view showing the paddle closing wheels and how they are attached to a central block of the adjustable frame structure of FIG. 4 ; and
FIG. 7 is an exploded view of a paddle closing wheel having a body portion, a series of radially extending fingers disposed about the perimeter of the body portion, and a series of paddles coupled to the fingers, wherein the paddle closing wheel includes a hub assembly for rotatably attaching the paddle closing wheel to the central block of the adjustable frame structure of FIG. 4 .
DETAILED DESCRIPTION
Good soil 20 contact with the seed 22 is one of the most important aspects of obtaining uniform emergence. If the sides 24 of a seed trench 26 do not close in over the seed 22 , there is poor seed 22 to soil contact as shown in FIG. 1 . If the seed trench 26 cracks open and exposes the seed 22 , the seed 22 dries out and does not germinate as shown in FIG. 2 . If the seed trench 26 closes at the top without soil directly above the seed 22 , the seed 22 may germinate, leaf out, and then be unable to penetrate the crust as shown in FIG. 3 . The present disclosure causes the reduction or elimination of air pockets and promotes higher yields by creating an ideal seedbed condition in unfavorable soil/planting conditions
Turning now to FIGS. 4-7 , wherein like reference numerals are used to indicate like elements, there is illustrated a paddle sealer 38 . The paddle sealer 38 generally includes an adjustable frame structure 39 including an arm assembly 40 and an attachment mechanism 42 for attaching the paddle sealer 38 to seeding equipment pulled by a motive source, such as a tractor (not shown), and a paddle closing wheel assembly 44 carried by the adjustable frame structure 39 . Referring to FIGS. 4 and 5 , the arm assembly 40 includes first and second generally parallel arms 46 , 48 having a first end 50 and a second end 52 . The arm assembly is generally parallel to a soil surface. The first ends 50 of the parallel arms 46 , 48 are secured to the attachment mechanism 42 .
In particular, the attachment mechanism in the form of a bracket assembly 42 includes first and second walls 54 , 56 that are generally parallel to the parallel arms 46 , 48 and a third wall 58 that is transverse to and extends between the first and second walls 54 , 56 . Each of the first and second walls 54 , 56 includes a bushing or bearing 60 . A bolt 70 extends through the bushing 60 , through an aperture 72 disposed in the arm 46 , through the bearing 62 , and through an aperture 74 disposed in the arm 48 . A locknut 76 is secured to the bolt 70 to retain the bolt within the bushings 60 and apertures 72 , 74 . The bushings 60 , bolt 70 , and locknut 76 act to attach the arm assembly 40 and the bracket assembly 42 . The bushings 60 , allow movement of the arm assembly 40 with respect to the bracket assembly 42 about an axis formed by the bolt 70 .
As seen in FIG. 5 , apertures 80 are disposed through the first and second walls 54 , 56 and a bolt 82 extends through the apertures and is axially retained by a locknut 84 . The bolt 82 functions to attach a tension assembly 86 to the arm assembly 40 . Specifically, a generally cylindrical opening 88 is disposed at a lower end 90 of a generally cylindrical rod 92 . The rod is attached to the bolt 82 with the bolt extending through the opening 88 of the rod 92 . The rod 92 extends upwardly through an aperture 93 extending through a retention plate 94 , wherein the retention plate 94 is attached to upper edges 96 of the parallel arms 46 , 48 . The retention plate 94 rests on parallel arms 46 , 48 . A spring 100 is disposed around a central portion 102 of the rod 92 and a washer 104 and a bolt 106 are retained on an upper end 108 of the rod 92 to further retain the spring 100 between the upper end 108 of the rod 92 and the retention plate 94 . Bolt 106 can be rotated to adjust down force applied to paddle wheel closing assemblies 44 .
Still referring to FIGS. 4 and 5 , L-shaped projections 120 extend outwardly from the first and second walls 54 , 56 of the bracket assembly 42 . The projections 120 include first and second segments 122 , 124 , wherein each of the arms 46 , 48 rests on a first segment 122 of a respective projection 120 . The projections 120 generally function to prevent too much downward movement of the arm assembly 40 , which will be discussed in greater detail below.
The bracket assembly 42 further includes connecting walls 130 , 132 , as seen in FIGS. 4 and 5 , that are attached to or integral with the third wall 138 and which extend in a direction opposite the first and second walls 54 , 56 . The connecting walls 130 , 132 , together with bolts 134 (that extend through apertures 135 ) and locknuts 136 attach the paddle sealer 40 to the seeding equipment.
As best seen in FIGS. 4 and 5 , a generally square-shaped tube 140 is disposed at the second end 52 of the parallel arms 46 , 48 of the arm assembly 40 . The square-shaped tube 140 includes a hollow, square-shaped cavity 142 and is attached to the parallel arms 46 , 48 . The arms 46 , 48 and tube 140 may be formed as a single, integral piece or otherwise formed separately and attached by means known in the art, such as by welding. The paddle closing wheel assembly 44 includes a generally square-shaped stem 146 held within the cavity 142 of the square-shaped tube 140 . In particular, an upper end 147 of the stem 146 includes multiple sets of opposing apertures 148 that are aligned with a single set of apertures 150 in the square-shaped tube 140 to permit vertical adjustability of paddle closing wheels 200 . A hitch pin 152 is inserted through the aligned apertures 148 and 150 to retain the stem 146 within the tube 140 and a cotter pin 151 is inserted through a channel in the pin 152 to retain the pin 152 within the apertures 148 and 150 . Optionally, a clip or other retaining mechanism may be utilized to prevent removal of the hitch pin 152 .
The stem 146 is adjustable in that the hitch pin 152 may be removed and the stem 146 may be moved up and down to align any set of apertures 148 in the stem 146 with the apertures 150 in the tube 140 . The adjustment allows the paddle closing wheel assembly 44 to be moved toward and away from the ground/soil, depending on a height of the soil, dampness/dryness of the soil, and/or other soil or surrounding conditions. The stem 146 may also be entirely removed from the square-shaped tube 140 when the paddle closing wheel assembly 44 is not necessary. As will be apparent to one skilled in the art, any number of sets of apertures 148 may be utilized to allow for further adjustability and/or a single set of apertures 148 may be utilized in the stem 146 and multiple sets of apertures 150 may be utilized in the tube 140 .
Referring to FIG. 6 , the paddle closing wheel assembly 44 further includes a central block or wheel hub 160 attached to or integral with a second, lower end 162 of the tube 140 . The central block 160 is adapted to allow for attachment of paddle closing wheels 200 . The central block 160 includes first and second opposing walls 164 that are generally parallel to a lateral axis 168 of the block. The central block 160 further includes third and fourth opposite walls 170 , wherein the walls 170 are arranged in a positive camber orientation and a toe-in orientation. Specifically, with regard to the positive camber orientation, the walls 170 angle inwardly from upper ends 172 to lower ends 174 of the walls 170 . The positive camber creates an angle A with respect to a vertical axis 176 of the central block 160 . In addition, the toe-in orientation creates an angling of the walls 170 inwardly between a first longitudinal end 178 and a second longitudinal end 180 of the walls 170 . The toe-in therefore creates an angle B with respect to a longitudinal axis 182 of the block 160 . The angle A is about 13 degrees and the angle B is about 9 degrees. Each of the walls 170 includes an opening 184 , which will be discussed in greater detail below.
Paddle closing wheels 200 , as best seen in FIGS. 6 and 7 , are rotatably attached to the third and fourth walls 170 of the central block 160 , as will be described in detail below. Each of the paddle closing wheels 200 includes a body portion 202 that is provided with a central opening 204 for connection to a hub assembly 206 . The central opening 204 includes a series of radially extending slots 208 that allow for use of bolts 210 and nuts 212 for coupling the paddle closing wheels 200 to the hub assemblies 206 . While only one bolt 210 and one nut 212 are shown in FIG. 7 , any number of bolts and nuts may be utilized, as can better be seen in FIG. 6 .
The hub assembly 206 attaches to the center of the paddle closing wheel 200 and permits the paddle closing wheel 200 to rotate. The hub assembly 206 includes an inner hub 218 and an outer hub 220 that is configured to be secured to the inner hub 218 . The inner hub 218 is positioned on one side of the paddle closing wheel 200 , the outer hub 220 is positioned on an opposite side of the paddle closing wheel 200 , and the bolts 210 extend through the inner and outer hubs 218 , 220 to secure the inner and outer hubs 218 , 220 to the paddle closing wheel 200 . The paddle closing wheel 200 also includes a number of fingers 230 (only some of which are labeled) that radially extend from the body portion 202 of the paddle closing wheel 200 . The fingers 230 include first side edges 232 and second side edges 234 connected by a crown portion 235 , wherein generally rectangular paddles 236 are mounted to the first side edges 234 (only some of the first and second side edges 232 , 234 , crown portions 235 , and paddles 236 are labeled for clarity of the drawings).
While the paddles 236 are shown as being rectangular in shape, the paddles may be circular, oval-shaped, square-shaped, or any other shape that allow for churning of soil. Between each of the fingers 230 is a recessed area 238 (again, only some recessed areas 238 are labeled) that is configured to reduce soil buildup between the fingers 230 during operation. The fingers 230 are equally spaced around a periphery of the wheel 200 so that the paddles 236 can make contact with the soil in a constant manner. The paddles 236 churn the soil to break up dirt and clods and push soil toward the seed trench. The paddles 236 can be cast with the fingers 230 or welded or otherwise attached in position.
The paddle closing wheels 200 can be fabricated from metal stock, poured as a casting, or laser cut with the paddles 236 formed on the end of each finger 230 . The paddles 236 chop and churn the soil without soil buildup between the fingers 230 . The angle of attack of the paddles 236 moves soil towards the seed trench to thoroughly cover the seed.
The preferred paddle closing wheels 200 have a diameter from about 14″ in diameter to about 16″ in diameter and preferably are 15″ in diameter. The paddle closing wheels 200 preferably include approximately sixteen fingers 230 to achieve maximum soil churning (to create finer soil particles). In addition, the paddles 236 are about 4.5 inches wide.
Referring to FIG. 7 , the inner hub 218 includes a bearing 226 to allow the paddle closing wheels 200 to be rotated. In particular, a bolt 250 is inserted through a washer 252 , through the bearing 226 , and into the opening 184 formed in the central block 160 . A nut 254 is thereafter secured to the bolt 250 (within a hollow interior of the central block 160 ) to rotatably secure each paddle closing wheel 200 to the central block 160 . Because the paddle closing wheels 200 are individually attached to the central block 160 , the paddle closing wheels 200 rotate independently of one another.
Due to the positive camber and toe-in orientations of the central block 160 , the paddle closing wheels 200 , when looking from a top view (viewing a plane formed by the lateral and longitudinal axes 168 , 182 ) form a V-shape with the paddle wheels 200 closer together at a leading end 260 ( FIG. 4 ) of the paddle sealer 38 and, when looking from a front view (viewing a plane formed by the lateral and vertical axes 168 , 182 ) form a V-shape at a soil end 262 ( FIG. 4 ) of the paddle sealer 38 . This orientation of the paddle closing wheels 200 allows the wheels to, once a seed trench is cut into the soil and a seed and/or fertilizer is deposited, move the soil to cover up the seed and/or fertilizer.
All components of the paddle sealer 38 may be manufactured of steel or other similar material. Optionally, one or more components of the paddle closing wheels 200 may be made of plastic or other similar material.
During use of the paddle sealer 38 , as noted above, the paddle closing wheels 200 ride along the soil. The ground and soil are not always level. Therefore, to prevent disturbance to one or more seeds due to uneven ground or soil and/or the creation of uneven ground, the spring-loaded rod 92 allows up and down movement of the arm assembly 40 . In particular, when uneven ground is encountered, rather than transferring all of the force into the ground, the force is transferred into the arm assembly 40 , which, due to the spring-loaded rod 92 moves up and down, as necessary. As noted above, the L-shaped projections 120 prevent too much downward movement and force of the paddle closing wheels 200 to prevent damage to the soil and further provide an even and consistent seedbed.
Although directional terminology, such as front, back, upper, lower, etc. may be used throughout the present specification, it should be understood that such terms are not limiting and are only utilized herein to convey the orientation of different elements with respect to one another.
Numerous modifications to the present disclosure will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is presented for the purpose of enabling those skilled in the art to make and use the invention and to teach the best mode of carrying out same. The exclusive rights to all modifications which come within the scope of the appended claims are reserved. | A paddle sealer used for planting having closing wheels that are drawn by a motive power source such as a tractor and used to close seed trenches to prevent the seed trench from reopening and provide the proper soil conditioning to promote uniform germination and emergence. The paddle sealer with closing wheels includes an adjustable frame structure including a tensioned arm assembly and an attachment mechanism for attaching the paddle sealer to seeding equipment, and a paddle closing wheel assembly carried by the arm assembly. | 0 |
CROSS REFERENCE TO RELATED APPLICATION
This application claims priority to and the benefit of U.S. Provisional Application No. 61/705,256 filed on Sep. 25, 2012, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention generally relates to aircraft passenger seats. More specifically, embodiments of the present invention relate to systems, methods, and apparatuses for integrating and/or securing a child seat into a certified aircraft seat.
The designs of current aircraft seats and restraint systems are inadequate for safely securing and restraining children. As such, the Federal Aviation Administration recommends that all children weighing under 40 pounds be seated in an approved child restraint system (CRS) in order to protect a child during take-off, landing, taxing, turbulence, and in the event of an emergency. Many current aftermarket child seats are designed for use in automobiles and thus are not designed or tested for use in an aircraft seat system. Hence many aftermarket child seats are not certified or are too large for use with aircraft seats. Additionally, aftermarket child seats may weigh a significant amount, be cumbersome to install, and difficult to transport. The use of strap on harnesses and belly harnesses have been proposed to address some of the safety issues, however, both of these attempts were banned by the FAA in the United States and have been shown to be ineffective.
When using portable child seats in an airplane, the portable seat must be placed in the aircraft seat and restrained to the seat using the already existing seat belt. Traditional aircraft seat belts are secured to seat spreaders at a low point so that the belt rests comfortably across the lap of a seated adult passenger. One problem with using the already existing aircraft seat belt is that a forward facing child seat may lack support on the top section of the seat. Thus securing a portable child seat in such a manner may not provide adequate protection for a seated child in the event of heavy turbulence or a crash. Portable child seats may also be disadvantageous because they may have a significant weight penalty (e.g., approximately 15 lbs.).
In light of the above, it would be desirable to provide improved systems, methods and apparatuses for safely securing and restraining children in an aircraft. In particular, improvements can be made to provide for a safer and more robust child restraint system for use in passenger aircraft.
SUMMARY OF THE INVENTION
The terms “invention,” “the invention,” “this invention” and “the present invention” used in this patent are intended to refer broadly to all of the subject matter of this patent and the patent claims below. Statements containing these terms should be understood not to limit the subject matter described herein or to limit the meaning or scope of the patent claims below. Embodiments of the invention covered by this patent are defined by the claims below, not this summary. This summary is a high-level overview of various aspects of the invention and introduces some of the concepts that are further described in the Detailed Description section below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in isolation to determine the scope of the claimed subject matter. The subject matter should be understood by reference to appropriate portions of the entire specification of this patent, any or all drawings and each claim.
Some embodiments of the invention are directed to improved methods of securing a child seat to a certified aircraft seat. Additionally, some embodiments of the present invention are directed to an integrated child seat which may be an integral part of the passenger seat design, thereby having a reduced weight penalty compared to a separate portable child seat. The integrated child seat may be deployed from a stowed position to a deployed position in order to accommodate and safely secure a seated child. In some embodiments, the child seat may be integrated into an aircraft seat backrest. When deployed, the child seat may be forward facing and include a five-point harness for securing and restraining a child. Preferably, the five-point harness may be routed through the integrated seat backrest structure and coupled with the seat backrest and/or an internal seat frame structure. Optionally, the mounting points or routing channels are reinforced with unique brackets attached to the internal seat frame structure. The brackets may couple with the back side of the internal seat frame structure and may help distribute load forces from a routed harness to the internal frame. In some embodiments, the child seat may be returned from a deployed position to a stowed position by stowing the child seat into the aircraft seat backrest such that the aircraft seat may then accommodate an adult passenger. Advantageously, some embodiments of the present invention may provide an integrated child seat that is intuitive to operate and which does not require installation or modification by flight crew or maintenance personnel.
In some aspects of the present invention, a passenger airplane seat is provided. The passenger airplane seat may include a seat backrest supported by an internal frame structure and the seat backrest may include an integrated seat. The integrated seat may include an integrated seat base, an integrated seat backrest, and an integrated seat harness. The integrated seat base may be moveable between a stowed position, where the seat may be configured to accommodate an adult, and a deployed position, where the seat may be configured to accommodate a child. The integrated seat harness may route through the integrated seat backrest and couple with the internal frame structure.
In some embodiments, the internal frame structure may include one or more routing channels for coupling the integrated seat harness. Optionally, the one or more routing channels may include an anti-friction trim for harness routing. In some embodiments, the one or more routing channels may be reinforced with one or more brackets disposed around the one or more routing channels. The one or more brackets may be coupled with the internal frame structure on a back side of the internal frame structure—the back side being opposite the integrated seat. Such a configuration may provide improved mechanical stability around the routing channels and may improve the distribution of load forces from a coupled harness to the internal seat frame, thereby providing a more reliable and secure harness.
The one or more routing channels may optionally extend through the one or more brackets. In some embodiments, the one or more routing channels of the internal frame structure may include two upper routing channels for receiving the integrated seat harness. The two upper routing channels may be disposed at a first height and may be defined as slit openings in a horizontal orientation. Further, the one or more routing channels of the internal frame structure may also include two lower routing channels for receiving the integrated seat harness. The two lower routing channels may be at a second height and may be defined as slit openings in a vertical orientation. The lower routing channels may be at a lower height than the upper routing channels. The one or more routing channels of the internal frame structure may also include two middle routing channels for receiving the integrated seat harness. The two middle routing channels may be disposed at a third height and may be defined by a slit opening in a horizontal orientation. The middle routing channels may be positioned at a height between the upper routing channels and the lower routing channels.
In some embodiments, the one or more brackets may include an upper bracket for reinforcing the two upper routing channels. The upper bracket may be coupled with the back side of the internal frame structure at the first height. The upper bracket may be disposed around the two upper routing channels such that the two upper routing channels extend through the upper bracket. Optionally, the one or more brackets may further include a lower bracket for reinforcing the two lower routing channels. The lower bracket may be coupled with the back side of the internal frame structure at the second height. The lower bracket may be disposed around the two lower routing channels such that the two lower routing channels extend through the lower bracket. In some embodiments, the one or more brackets also include a middle bracket for reinforcing the two middle routing channels. The middle bracket may be coupled with the back side of the internal frame structure at the third height. The middle bracket may be disposed around the two middle routing channels such that the two middle routing channels extend through the middle bracket.
In some embodiments, the integrated seat base may be supported by an internal integrated seat base frame structure and the integrated seat harness may also route through the integrated seat base and couple with the internal integrated seat base frame structure. Optionally, the integrated seat harness may route horizontally between the two lower routing channels. Additionally, in some embodiments, the integrated seat harness may route vertically between the two upper routing channels and the two middle routing channels. In some embodiments, the integrated seat may be manufactured from an antimicrobial material, an antibacterial material, a water-resistant material, and/or a stain-resistant material.
In another aspect of the present invention, a passenger seat is provided that may include a seat backrest supported by an internal frame structure and the internal frame structure may including one or more routing channels for coupling a seat harness apparatus. The one or more routing channels may be reinforced with one or more brackets disposed around the one or more routing channels. The one or more brackets may be coupled with the internal frame structure on a back side of the internal frame structure—the back side being opposite the seat harness apparatus. In some embodiments, the one or more routing channels of the internal frame structure may include two upper routing channels for receiving the seat harness apparatus. The two upper routing channels may be disposed at a first height and in a horizontal orientation. Additionally, the one or more routing channels of the internal frame structure may further include two lower routing channels for receiving the seat harness apparatus. The two lower routing channels may be at a second height and in a vertical orientation. The second height may be less than the first height. Optionally, the one or more routing channels of the internal frame structure may further include two middle routing channels for receiving the seat harness apparatus. The two middle routing channels disposed at a third height and in a horizontal orientation. The third height may be less than the first height and greater than the second height.
In some embodiments, the one or more brackets may include an upper bracket for reinforcing the two upper routing channels. The upper bracket may be coupled with the back side of the internal frame structure at the first height. The upper bracket may be disposed around the two upper routing channels such that the two upper routing channels extend through the upper bracket. In some embodiments, the one or more brackets may further include a lower bracket for reinforcing the two lower routing channels. The lower bracket may be coupled with the back side of the internal frame structure at the second height. The lower bracket may be disposed around the two lower routing channels such that the two lower routing channels extend through the lower bracket. Optionally, the one or more brackets may further include a middle bracket for reinforcing the two middle routing channels. The middle bracket may be coupled with the back side of the internal frame structure at the third height. The middle bracket may be disposed around the two middle routing channels such that the two middle routing channels extend through the middle bracket. In some embodiments, the passenger airplane seat may further include a seat harness apparatus. The seat harness apparatus may route horizontally between the two lower routing channels. In some embodiments, the seat harness may route vertically between the two upper routing channels and the two middle routing channels.
In other embodiments of the present invention, a passenger airplane seat for use in commercial aircraft is provided. The passenger airplane seat may include a seat base coupled with a seat backrest for supporting a seated passenger. The seat backrest may be internally supported by an internal frame structure. The passenger airplane seat may include seat spreaders disposed on opposing sides of the seat base and a seat belt attached to the seat spreaders. The seat backrest may include an integrated seat and the integrated seat may include an integrated seat base, an integrated seat backrest, and a five-point harness system. The integrated seat base may be moveable between a stowed position and a deployed position. The passenger airplane seat may be configured to accommodate an adult passenger when the integrated seat base is in the stowed position and may be further configured to accommodate a child passenger when the integrated seat base is in the deployed position. Preferably, the five-point harness of the integrated seat may couple with the internal frame structure by routing through a plurality of routing channels extending through the integrated seat backrest and through the internal frame structure. Optionally, one or more reinforcing brackets may be coupled with a back side of the internal frame structure and disposed around the plurality of routing channels—the back side being opposite the integrated seat.
The invention will be better understood on reading the following description and examining the figures that accompany it. These figures are provided by way of illustration only and are in no way limiting on the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-1C illustrate certain exemplary embodiments of the present invention and the deployment of the exemplary integrated seat;
FIG. 2 illustrates details of an exemplary harness system for use with the illustrated integrated seat;
FIG. 3 illustrates an exemplary seat backrest frame structure according to some embodiments of the present invention for attaching the integrated seat illustrated in FIG. 2 ; and
FIGS. 4A-4C illustrate the back side of an exemplary seat backrest frame structure according to some embodiments of the present invention.
DETAILED DESCRIPTION
The subject matter of embodiments of the present invention is described here with specificity to meet statutory requirements, but this description is not necessarily intended to limit the scope of the claims. The claimed subject matter may be embodied in other ways, may include different elements or steps, and may be used in conjunction with other existing or future technologies. This description should not be interpreted as implying any particular order or arrangement among or between various steps or elements except when the order of individual steps or arrangement of elements is explicitly described.
FIGS. 1A-1C illustrate exemplary embodiments of the present invention and the deployment of an exemplary integrated seat. FIG. 1A illustrates an exemplary aircraft passenger seat system 10 including passenger seats 12 , 14 . Passenger seats 12 , 14 are certified aircraft seats and are suitable for seating adult passengers and securing them with a seat belt system. Traditionally, the seat belt is attached to seat spreaders 13 that are positioned on each side of the seats 12 , 14 . Passenger seats 12 , 14 include a seat base 15 , 16 and a seat backrest 17 , 18 , respectively. Seat backrest 18 includes an integrated seat 20 in a stowed position whereas seat backrest 17 is illustrated without an integrated seat for comparison purposes. In some embodiments, integrated seat 20 may include a pull tab 22 to facilitate deployment of the integrated seat 20 from the stowed position to a deployed position, as illustrated in FIG. 1B and FIG. 1C .
FIG. 1B illustrates the deployment of integrated seat 20 from the stowed position shown in FIG. 1A to a deployed position shown in FIG. 1C . Integrated seat 20 includes an integrated seat base 24 , an integrated seat backrest 26 , and an integrated seat harness 28 . The integrated seat base 24 may pivot in the direction of arrow 30 relative to integrated seat backrest 26 when deploying from the stowed position to the deployed position.
FIG. 1C illustrates integrated seat 20 in the deployed position. In the deployed position, integrated seat base 24 may rest on seat base 16 and/or may be locked in a position relative to seat backrest 26 . When in the deployed position, integrated seat base 24 , integrated seat backrest 26 , and integrated seat harness 28 may form a seat suitable for safely securing and restraining a child. In order to return the integrated seat 20 from the deployed position to the stowed position, integrated seat base 24 may be unlocked from the deployed position if needed, and moved back to the stowed position illustrated in FIG. 1A .
While passenger seat system 10 is illustrated with two passenger seats 12 , 14 , it should be understood that passenger seat system 10 may include any number of passenger seats. For example, some passenger seat systems may include one, three, four, five, six or more passenger seats. Additionally, while only passenger seat 14 is illustrated with an integrated seat 20 , it should be understood that any, some or all passenger seats in a passenger seat system may include an integrated seat 20 . Advantageously, in some embodiments, an integrated child seat may have a lower weight penalty compared to a separate carry-on child seat.
In some embodiments, when integrated seat 20 is in a stowed position, passenger seat 14 has an outward appearance and configuration similar to passenger seat 12 . Accordingly, passenger seat 14 may accommodate adult passengers when the integrated seat 20 is stowed. In some embodiments, seat backrest 18 may include a rearward relief in order to completely house the integrated seat 20 when the integrated seat 20 is in the stowed position. Optionally, when stowed, integrated seat 20 may be locked in place or friction fit within the rearward relief to keep the integrated seat 20 in the stowed position. When deployed to the deployed position, it may be preferable to lock integrated seat base 24 relative to integrated seat backrest 26 in order to limit movement of the integrated seat 20 while the seat is in use and during aircraft take-off, landing, taxing, in-flight turbulence, and/or during emergency situations. In some embodiments, integrated seat base 24 and/or integrated seat backrest 26 may include a cover or cushion fashioned out of an antibacterial, antimicrobial, water-resistant, and/or stain resistant material.
In some embodiments, the integrated seat harness 28 may be concealed by the integrated seat base 24 when the integrated seat base 24 is in the stowed position. The integrated seat harness 28 is preferably a five-point seat harness as illustrated in FIGS. 1A-1C . Advantageously, a five-point harness may support and transfer forces over the hips and shoulders of a child's body. Other configurations are possible, such as a two-point lap or sash harness, or a three-point, four-point, six-point harness, etc. FIG. 2 illustrates details of an exemplary five-point harness system 28 for use with the illustrated integrated seat 20 . The five-point harness system 28 includes two shoulder straps 32 , two pelvic straps 34 , and a crotch strap 36 . In some embodiments, and as illustrated in FIG. 2 , shoulder straps 32 and corresponding pelvic straps 34 may be formed from a single belt. Each strap 32 , 34 , 36 may couple to a buckle release mechanism 38 . Integrated seat harness 28 may also include a channel for belt adjustment, a crotch strap adjustment and pelvic strap adjustment. Additionally, shoulder strap height may be adjusted by positioning and securing shoulder straps 34 at a desired height along portion 40 . Portion 40 and pelvic straps 34 may route through integrated seat backrest 26 using routing channels 42 . Routing channels 42 may be slits in the integrated seat backrest 26 and may employ anti-friction trims 44 for harness routing. In some embodiments, integrated seat base 24 may be supported by an internal frame structure and may include one or more routing channels to couple with integrated harness 28 . For example, as illustrated in FIG. 2 , crotch strap 36 may route through routing channel 42 to couple with an internal frame structure of integrated seat base 24 . Preferably, in some embodiments, portion 40 and pelvic straps 34 route through integrated seat backrest 26 to attach to and secure integrated seat harness 28 to an internal seat backrest frame structure 46 as can be more clearly seen in FIG. 3 .
FIG. 3 illustrates exemplary passenger seat 14 without a seat backrest cushion to illustrate some details of an exemplary attachment of integrated seat harness 28 with internal frame structure 46 . As shown in FIG. 3 , internal frame structure 46 may include a plurality of routing channels for coupling with integrated seat harness 28 . The plurality of routing channels may include two upper routing channels 48 , 50 , two middle routing channels 52 , 54 , and/or two lower routing channels 56 , 58 (illustrated in FIG. 4 ) that extend through seat backrest frame structure 46 . The routing channels may be slit openings for routing one or more portions of harness 28 through seat backrest frame structure 46 . Upper routing channels 48 , 50 and middle routing channels 52 , 54 may have a generally horizontal orientation. Lower routing channels 56 , 58 may have a generally vertical orientation. Advantageously, routing integrated seat harness 28 through upper routing channels 48 , 50 and/or middle routing channels 52 , 54 may provide support on the top section of a child seat and may provide improved protection for a seated person in the event of turbulence or a crash. In some embodiments, a portion of integrated seat harness 28 may route vertically between routing channel 48 and routing channel 52 to couple harness 28 with seat backrest frame structure 46 . A portion of integrated seat harness 28 may also route vertically between routing channel 50 and routing channel 54 . In some embodiments, pelvic straps 34 route horizontally between routing channel 56 and routing channel 58 , can be seen in FIGS. 4A-4B .
Optionally the plurality of routing channels may include trim 44 which also extends through integrated seat backrest 26 and through seat backrest frame structure 46 or which extend through integrated seat base 24 and through its internal support structure. According to some embodiments of the present invention, seat backrest frame structure 46 may couple with one or more brackets for reinforcing the one or more routing channels as shown in FIGS. 4A-4B .
FIGS. 4A-4C illustrate the back side of seat backrest frame structure 46 according to some embodiments of the present invention. Frame structure can be constructed from composite materials, sheet metal, metal tubing for the frame or any suitable combination of such materials. In the illustrated embodiment, the one or more brackets include an upper bracket 62 , a middle bracket 64 , and a lower bracket 66 that attach on the back side of seat backrest frame structure 46 . The brackets may be constructed from composite materials, sheet metal, plastics or any suitable combination of such mentioned materials. Upper bracket 62 may be positioned around upper routing channels 48 , 50 so as to reinforce the upper routing channels 48 , 50 . Middle bracket 64 may be positioned around middle routing channels 52 , 54 so as to reinforce the middle routing channels 52 , 54 . Lower bracket 66 may be positioned around lower routing channels 56 , 58 so as to reinforce the lower routing channels 56 , 58 . In some embodiments, routing channels and/or corresponding trims may extend through the reinforcing bracket. The reinforcing brackets may extend horizontally across the back side of seat backrest frame structure 46 and may be mechanically coupled with seat backrest frame structure 46 using one or more fasteners and/or chemically coupled with seat backrest frame structure 46 with an adhesive compound. The reinforcing brackets 62 , 64 , 66 may help distribute load forces from an attached seat harness to the seat backrest frame structure 46 thereby providing an improved restraint system. Accordingly, some embodiments of the present invention may decrease the probability and severity of injury to a restrained passenger during take-off, landing, taxing, inflight turbulence and in the event of an emergency situation. FIG. 4C illustrates belt 32 routing between the upper channels 48 , 50 and middle channels 52 , 54 , respectively, along the back side of the internal frame structure 46 .
While the embodiment shown in FIGS. 4A-4C includes three reinforcing brackets 62 , 64 , 66 , other embodiments of the invention may use one, two, four, or more brackets for reinforcing the one or more routing channels. In some embodiments, each routing channel may be individually reinforced by a corresponding bracket. Other embodiments of the present invention may forgo the use of any reinforcing brackets. In such an embodiment, the mounting points may be an integral part of the composite back design thereby eliminating the need for additional reinforcing components.
Further, some embodiments of the present invention may provide an aircraft passenger seat where the passenger seat base includes the integrated seat. In some embodiments, the integrated seat may be a rearward facing child seat when deployed from the stowed position to a deployed position. In such an embodiment, the integrated seat backrest may fold out from a stowed position away from the seat backrest and may be locked in position. The integrated seat harness may route through the seat base and couple with an internal frame structure of the seat base. In some embodiments, the internal frame structure of the seat base may include a plurality of routing channels for routing and securing the integrated seat harness.
Different arrangements of the components depicted in the drawings or described above, as well as components and steps not shown or described are possible. Similarly, some features and sub-combinations are useful and may be employed without reference to other features and sub-combinations. Embodiments of the invention have been described for illustrative and not restrictive purposes, and alternative embodiments will become apparent to readers of this patent. Accordingly, the present invention is not limited to the embodiments described above or depicted in the drawings, and various embodiments and modifications may be made without departing from the scope of the claims below. | The present invention generally relates to passenger aircraft seats. Some examples provide systems for integrating a child seat into a certified aircraft seat. Some examples include a passenger seat backrest having an integrated child seat. An integrated child seat base may be moved between a stowed position and a deployed position. When in the stowed position, the integrated child seat base may fit within a recessed surface of the seat backrest and the seat may then accommodate an adult passenger. When in a deployed position, the integrated child seat may then accommodate a child passenger. The integrated seat may include a harness system that extends through the seat backrest and couples with an internal support structure of seat backrest. In some embodiments the mounting points of the harness system may be reinforced with stiff brackets attached to the internal support structure. | 1 |
TECHNICAL FIELD
The present teachings relate to friction material for clutches, and more particularly to a friction material having a configuration suitable for wet clutch applications.
BACKGROUND
The present teachings generally relate to a friction material that can be used in clutch applications, such as a multi-plate wet clutch pack in a limited slip differential system. Friction plates and the friction material on the plates affect the reliability and quality of clutch engagement.
When wet clutches engage and slide against each other, the contacting friction surfaces generate heat. Oil can be applied to the friction plates to cool the contacting components, either by center-fed forced cooling (where oil is pumped through channels in the center of an input shaft and exits through holes in the center of a clutch hub to flow into the clutch pack) or splash cooling (where a differential housing is filled with oil that splashes on the clutch plates). Forced cooling systems allow adjustment of the oil flow rate based on the cooling demand, but incorporating the pump and fluid channels adds complexity to the differential system.
By contrast, splash cooling is a passive cooling method and does not require any special modifications to the differential system. However, the clutch packs in LSD systems are always engaged (e.g., adjacent friction plates and separator plates are always in contact with each other). This makes it difficult for sufficient oil to reach the clutch interface and cool the clutch. In other words, splash-cooled wet clutches tend to have low cooling efficiency.
SUMMARY
One aspect of the present teachings is directed to a friction plate for a clutch assembly. The friction plate comprises a core plate having an inner diameter and a first outer diameter and a plurality of friction segments made of a friction material. A plurality of grooves are disposed between said plurality of friction segments, wherein each segment has tapered sides so that the grooves have a first width adjacent the first outer diameter and a second width, which is smaller than the first width, adjacent the inner diameter.
Another aspect of the present teachings is directed to a clutch assembly having a plurality of the friction plates described above disposed in an alternating fashion with a plurality of separator plates.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of a wet clutch pack according to one aspect of the teachings;
FIG. 2A is a plan view of a friction plate that can be used in the system of FIG. 1 ;
FIG. 2B is a close-up view of the friction plate in FIG. 2A ;
FIG. 2C is a close-up perspective view of the friction plate in FIG. 2A ;
FIG. 3 is a plan view of friction material that can be used in the friction plate of FIG. 2 ;
FIG. 4 is a plan view of another arrangement of friction material that can be used in the friction plate of FIG. 2 .
DETAILED DESCRIPTION
FIG. 1 illustrates components in a wet clutch 10 according to one aspect of the teachings. The wet clutch 10 can include friction plates 12 and separator plates 14 arranged in an alternating manner.
As shown in FIGS. 2A , 2 B, and 2 C, the friction plate 12 can include a core plate 16 and a friction lining 18 bonded to the core plate 16 via any known process. The separator plate 14 and the core plate 16 may both be made of steel. The core plate 16 may have ears 17 to act as clutch guides.
The friction lining 18 can be formed as a plurality of segments 20 with side surfaces 21 forming grooves 22 in between the segments 20 . The friction lining 18 may be formed of any appropriate material, such as a paper-based friction material containing aramid or other high-strength fibers and fillers and saturated with a thermosetting resin, such as a phenolic resin. Options for the friction material structure include woven, pultruded or compression-molded structures. Options for the friction material itself may include polyamide, carbon, ceramic, or any combination thereof. These options are only examples: the specific material and material structure is not critical to the teachings, and those of ordinary skill in the art will recognize that other options are within the scope of the teachings.
Grooves 22 act as fluid paths to allow oil to flow between the friction plates 12 and separator plates 14 for cooling. Deeper grooves 22 improve cooling efficiency and reduces thermal degradation of the friction lining 18 because deeper grooves 22 allow more cooling oil to circulate between the plates 12 , 14 . The grooves 22 can be made in various ways, such as molding grooves into the friction lining 18 or cutting the friction lining 18 to form the grooves 22 . Cutting or machining allows formation of deeper grooves 22 (i.e., thicker side surfaces 21 ) than molding and therefore can potentially improve the cooling efficiency of the wet clutch 10 . However, cutting the friction lining 18 material can create fuzziness and loose fibers at the cut edges due to fibers in the friction lining 18 material. The fuzzy edges can restrict oil flow, and the loose fibers can contaminate the oil.
The friction lining 18 shown in FIGS. 1 through 3 solves the above problems by dividing the friction lining 18 into discrete segments 20 . Creating separate segments 20 maximizes the depth of the grooves 22 and provides smooth side surfaces 21 that do not impede oil flow.
The number and shape of the segments 20 as well as the direction (e.g., radial vs. angled), width, and shape of the grooves 22 all affect the cooling efficiency of the wet clutch 10 and control the amount of thermal degradation in the friction lining 18 . For example, if the segments 20 are too large, there will be fewer grooves 22 , thereby reducing the amount of oil circulating through the wet clutch 10 , diminishing cooling efficiency, and increasing thermal degradation of the friction lining 18 . However, if there are too many segments 20 and grooves 22 , the increased number of grooves 22 reduces the load capacity of the wet clutch 10 by reducing the land area of the friction lining 18 , thereby increasing the amount of friction load each segment 20 must bear. This can potentially increase the wear rate of the friction lining 18 and reduce its compression fatigue life and reliability.
The number of friction segments 20 forming the friction lining 18 can be optimized to provide the best compromise between cooling efficiency and load capacity. FIGS. 2 and 3 illustrate two possible aspects of the teachings for purposes of illustration and not limitation. FIG. 3 illustrates a friction lining 18 arrangement having twelve friction segments 20 and twelve grooves 22 , while FIG. 4 illustrates a friction lining 18 arrangement having sixteen friction segments 20 and sixteen grooves 22 .
In both of these aspects, adjacent side surfaces 21 of the grooves 22 may taper slightly inward from an outer diameter of the core plate 16 to an inner diameter of the core plate 16 . The side surfaces 21 of the segments 20 can be straight, flared outward, or tapered slightly inward so that the sides surfaces of adjacent segments 20 form the inwardly tapering grooves 22 . Outer edges of the friction segments 20 form an outer diameter of the friction lining 18 , while inner edges of the friction segments 20 form an inner diameter of the friction lining 18 . In one aspect, the width of the tapered grooves 22 may be about 5 mm at the friction lining's 18 outer diameter and about 3 mm at the friction lining's 18 inner diameter to allow oil to flow into the wet clutch 10 easily.
Also, each friction segment 20 may have rounded corners 38 at the outer edges. In one aspect of the teachings, the radii of the rounded corners are generous, on the order of millimeters. The rounded corners 38 , together with the tapered side surfaces 21 forming the grooves 22 , create a funnel shape 23 , directing oil from the outer diameter of the core plate 16 toward the inner diameter 30 of the core plate 16 via random splashing and gravitational forces. In other words, the funnel shape formed by the friction segments 20 funnels oil into the clutch interface (i.e., between the friction plates 12 and the separator plates 14 ). As centrifugal forces push oil out of the wet clutch 10 during differential rotation, particularly during high-speed rotation without slippage, the rounded corners 38 guide the oil back into the clutch interface to maintain cooling action during low speed rotation with high slip speed.
As shown in FIG. 2B the friction lining 18 may also be shaped so the outer edges 33 of the friction segments 20 collectively form an outer diameter that is slightly less than the outer diameter of the core plate 16 , creating a margin 44 of bare metal around the perimeter of the friction lining 18 . In one aspect of the teachings, the margin 44 is approximately 1-2 mm wide. This margin 44 can improve cooling efficiency, as will be described in greater detail below.
In one aspect of the teachings, the number, shape, size, and arrangement of the friction segments 20 are selected to provide a reaction torque sufficient to provide traction if a driven wheel encounters a slip condition. In such slip conditions, the wet clutch 10 can experience high sliding speeds (e.g., greater than 500 rpm), high pressures (e.g., greater than 3 MPa), and long slip durations (e.g., greater than 5 seconds). Therefore, the friction segments 20 can be designed so the overall friction lining 18 can withstand high density power inputs (e.g., greater than 2 W/mm 2 ).
During clutch operation, heat generated by the friction lining 18 is absorbed by the core plate 16 and the separator plate 14 . Thus, the interface between the friction plates 12 and the separator plates 14 can reach temperatures on the order of 400 C, which is hot enough to potentially degrade the friction lining 18 . To optimize cooling, contact between the oil and both the core plate 16 and separator plate 14 should be maximized so the oil can quickly absorb retained heat in the plates 14 , 16 . Since splashed oil initially tends to sit on the outside of the wet clutch 10 , the margin 44 increases the amount of metal contacting the oil before it is eased into the grooves 22 , thereby improving cooling efficiency. Also, the margin 44 helps create surface tension that holds in the oil between the core plates 16 and the separator plates 14 , prolonging the contract between the metal of the plates 14 , 16 and thereby increasing the heat transfer between the hot metal of the plates 14 , 16 and the oil.
It will be appreciated that the above teachings are merely exemplary in nature and is not intended to limit the present teachings, their application or uses. While specific examples have been described in the specification and illustrated in the drawings, it will be understood by those of ordinary skill in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present teachings as defined in the claims. Furthermore, the mixing and matching of features, elements and/or functions between various examples is expressly contemplated herein so that one of ordinary skill in the art would appreciate from this disclosure that features, elements and/or functions of one example may be incorporated into another example as appropriate, unless described otherwise, above. Moreover, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present teachings not be limited to the particular examples illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out the teachings of the present disclosure, but that the scope of the present disclosure will include any embodiments falling within the foregoing description and the appended claims. | A friction plate for a clutch assembly includes a core plate and a plurality of friction segments made of a friction material. A plurality of grooves are disposed between said plurality of friction segments. Each segment has tapered sides so that the grooves have a first width adjacent the outer diameter of the core plate and a smaller second width smaller adjacent the inner diameter of the core plate. This tapered groove structure directs oil from the outside the clutch assembly to the inside to improve cooling efficiency. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to liquid crystal display cells and in particular to the provision of molecular alignment layers on the interior major surfaces of the cell walls for promoting parallel homogeneous alignment of the liquid crystal molecules in contact with such layers.
For some years it has been known that parallel homogeneous molecular alignment can be achieved by rubbing a glass sheet with a suitable tissue. It was found that this rubbing left some residue on the glass, probably a grease, and that it was this rubbed residue which provided the alignment. Since then it has been common practice to apply a specific material such as polyvinyl alcohol to the glass, and to rub this to provide the required alignment. This works satisfactorily for cells which are sealed using standard plastic sealing technology, but neither the grease nor materials such as polyvinyl alcohol are able to withstand the sort of temperature required to form the glass frit seals that are required for high reliability devices. Glass frit sealing removes the alignment. One approach to this problem has been to replace the polyvinyl alcohol with a plastic material that can withstand higher temperatures such as polyimide which in suitable circumstances can withstand brief heating to a temperature of around 430° C. This is at the borderline of the temperature range required for glass frit sealing. A typical glass frit seal is fired at around 475° C.
Parallel homogeneous alignment that is fully compatible with glass frit sealing temperatures has previously been achieved by oblique evaporation of a suitable material such as silicon monoxide. The principal drawback of this approach is cost. The process requires quite a good quality vacuum, and requires a relatively large vacuum chamber in order to give an adequate spacing between target and source to minimize the variation in angle of deposition over the surface of the target.
SUMMARY OF THE INVENTION
According to the present invention there is provided a method of providing a liquid crystal parallel homogeneous molecular alignment layer on a glass substrate which method includes the step of applying a uniform thickness coating to the substrate of a solution containing organic compound that will hydrolyze in contact with glass to form an adherent film that can be pyrolyzed to convert the film into a layer consisting of or containing silica, the step of heating the coated substrate sufficient at least to drive off the solvent, the step of rubbing the coated substrate in a particular direction, and, if the heating step was not one that pyrolyzed the film, the step of firing the coated substrate to pyrolyze the film.
The invention thus resides in the discovery that although a typical glass substrate cannot satisfactorily be rubbed to provide a parallel homogeneous molecular alignment layer that will withstand glass frit firing temperature, and neither can a film of silica deposited by conventional chemical vapor reaction, a rubbed film of silica produced by pyrolyzing a layer deposited from the liquid phase is capable of withstanding glass frit firing temperatures without losing its molecular aligning properties.
DETAILED DESCRIPTION OF THE INVENTION
There follows a description of a method, embodying an invention in a preferred form, of providing a molecular alignment layer on a substrate that, together with another substrate and a perimeter seal, is to be used to form a liquid crystal display cell.
A soda-glass substrate typically 2 mm thick is provided with an indium/tin oxide transparent electrode pattern by the conventional method used in liquid crystal device technology. Optionally this electrode may be coated with a thin layer of silica deposited by chemical vapor reaction.
One class of suitable materials from which to form the requisite coating for rubbing is based on a suitable tetra-alkoxysilane, such as tetraethoxysilane. A particular material that may be used is the liquid used in semiconductor technology for forming silica coatings and marketed by Merck under the designation "Liquicoat SI". With this material a fired film thickness in the range 100 to 150 nm has been found suitable since significantly thicker films are liable to become crazed on firing. A coating of appropriate thickness can be obtained for instance by spinning; the method chosen in this particular instance is however dip coating. The substrate is lowered vertically on edge into the liquid at a controlled rate and then withdrawn from it again, also at a controlled rate. It was found that a coating of appropriate thickness was obtained using a withdrawal rate of about 10 cm per minute with a mixture of 60 parts by volume of the Liquicoat SI solution together with 40 parts of the thinners supplied for diluting the Liquicoat SI. Optionally the coating is subjected to preliminary drying as it is withdrawn from solution by directing a beam of light on to it from a projector lamp.
Initially some problems were encountered regarding uneven wetting of the glass substrate by the solution. These problems were attributed to the presence of moisture and were remedied by baking the substrates at 250° C. for an hour, cooling them in dry nitrogen to room temperature, and immersing them in the solution immediately after they were cool.
Normally a region of the electroded substrate will need to be uncoated in order to be able to make direct electrical connection with the or each electrode. This can readily be achieved using conventional masking tape.
Once the substrate has been withdrawn from the solution it has to be heated to drive off the solvent, hydrolyze the coating and then pyrolyze it. Typically the solvent may be driven off by heating for about 15 minutes at between 50° and 80° C. This leaves a relatively soft film which is hardened by further heating. The further heating may be in two stages with a preliminary heating typically at between 200° and 250° C., followed by a final firing typically at between 450° and 500° C. Alternatively the further heating may involve a single stage heating involving firing at a temperature within the higher range.
At some stage in the processing the coated substrate needs to be rubbed to provide it with the required molecular alignment properties. This may be done while the coating is still relatively soft after having had its solvent driven off, or it may be done after the preliminary heating of the hardening treatment, or it may be done after final firing at the high temperature.
In a particular example in which rubbing was performed after firing at 475° C. it was found that alignment of acceptable quality was obtained using a velvet-like texture cloth covered squeegee in the form of hard rubber blade. Between 2 and 10, and typically 5, strokes of the squeegee were required using a cloth marketed under the Registered Trade Mark SELVYT, and a force designed, having regard to the area of contact, to produce a pressure in the range 70 to 140 kilopascals (1 pascal=1 newton per square meter). After every few strokes of the squeegee it is desirable to index the cloth so that a fresh portion is used for rubbing, and in this way minimize the risk of gross scoring of the surface through the pick-up of contaminating particles.
In another example, which also involved rubbing after firing at 475° C., the rubbing was effected by using a brush type 15 cm diameter polishing wheel with bristles about 4 cm long. This was rotated at about 3,000 revolutions per minute to provide a measure of "stiffness" to the bristles, having regard to the hardness of the fired film. It was found that alignment of acceptable quality was produced by passing the substrate under the wheel typically between 10 and 20 times.
The rubbed substrates are in each case then ready for assembly with other such rubbed substrates, or substrates provided with molecular alignment by some other means, to form a liquid crystal cell whose perimeter seal is formed by a fused glass frit seal fired at a temperature typically in the range 450° to 500° C. Such a cell is filled with its liquid crystal medium in the conventional manner by evacuating the cell and back filtering it through an aperture either formed in one of the substrates or formed by an interruption in the ribbon of glass frit forming the perimeter seal.
A feature of molecular alignment layers formed in this way, compared with those formed by oblique evaporation is that this method provides an alignment in the rubbing direction with a small near-optimum tilt angle out of the plane of the layer. In contrast, a simple single oblique evaporation either produces molecular alignment with no tilt angle or one with a relatively large tilt angle. The absence of a tilt angle is undesirable in display devices because it is liable to produce randomly shaped regions of visually distinguishable texture due to the effects of reverse tilt. These effects are removed by the presence of a tilt angle, but if the tilt angle is too large it has a marked deleterious effect upon the viewing angle and switching speed and threshold of the cell. The avoidance of these problems of excessive tilt angle makes it easier to produce acceptable multiplexed devices, and, in the case of relatively large area cells, there is the added advantage that this method of alignment avoids the problem of the oblique evaporation associated with the fact that the alignment properties are a function of position on the surface of the substrate by virtue of the fact that the angle of deposition is a function of position.
A further advantage of the method of the present invention is that by suitable admixture of components in the coating solution it is possible to alter the refractive index of the fully fired film, and in particular to adjust it so that it substantially matches that of the material of the transparent electrodes. If such a coating is provided directly on the electroded substrate, with no intervening layer between the electrodes and the coating, a substantial match of their refractive indices will eliminate or at least reduce the entirely unwanted visibility of the electrode pattern.
Thus to the Liquicoat SI solution may be added an appropriate quantity of the related solution marketed by Merck under the designation Liquicoat TI. It has been found that a suitable mix comprises 24 parts by volume Liquicoat TI, 47 parts Liquicoat SI, and 29 parts thinners. In all other respects the processing using this mixture proceeded as previously described with reference to the solution consisting solely of Liquicoat SI and thinners.
The invention has been described by reference to a specific embodiment. Those skilled in the art will recognize that modifications other than those specifically mentioned can be made without departing from the spirit of the invention and the scope of the present invention is defined solely by the appended claims. | In a liquid crystal cell parallel homogeneous alignment of the liquid crystal molecules is provided by rubbing a silica or silica containing film produced by firing a silica containing organic coating applied in liquid form. The alignment provided by this process can withstand firing temperatures in the range 450° to 500° C. normally employed for making fused glass frit perimeter seals. By incorporating titania into the film the refractive index can be matched with that of the underlying electrodes and so render them substantially invisible. | 8 |
BACKGROUND OF THE INVENTION
The invention relates to an apparatus for electronically monitoring an adjusting drive arranged in a vehicle.
DE-A 44 16 803 already discloses a method and an apparatus for the adjustment of power-operated parts, in particular, in a vehicle body. Therein at least two redundantly operating sensor systems are used, thus improving the reliability for the collision recognition. This serves to prevent the jamming of objects in the power-operated parts.
SUMMARY OF THE INVENTION
The apparatus according to the invention electronically monitors an adjusting drive arranged in a vehicle for adjusting the position of a movable part and it offers the advantage that, by way of the targeted selection of two sensor systems, their properties contribute within a position-dependent anti-jam strategy to prevent faulty triggering, on the one hand, and to enhance the safety in a danger zone, on the other hand. A combination of a switching strip, which performs electrical switching responsive to the application or removal of a force or pressure, with an incremental path transmitter of an adjustable movable part is advantageous because a jam situation which is hazardous to persons is present when a person is disposed between the switching strip receiving the part and the moved part. It is therefore advantageous to monitor the end position as well as the edge of the part. Precisely that is accomplished with the method according to the invention. Regulations such as, for example, FMVSS 118 also differentiate in a position-dependent manner with regard to the safety requirements.
If, for example, the side window of a vehicle is almost completely open, it is unlikely that a jam situation occurs which is hazardous to persons. A faulty triggering caused by unintended touching of the switching strip is probably the rule. In order to reduce the probability of faulty triggering in this region, the anti-jam system only responds, halting closing of the window, if a jam is detected on the part of the incremental sensor monitoring the adjustable part, namely the window, and on the part of the switching strip.
In contrast, the anti-jam system must respond quickly if, for example, the side window is about to close. If a person's fingers, for example, happen to touch the switching strip at that time, the adjusting drive which moves the part must be switched off immediately to prevent possible bruising. Safety is increased if, in this case, the anti-jam system responds when either the switching strip or the incremental sensor detects a jam.
Based on the position-dependent evaluation, the incremental sensor lends itself as a sensor system, with the signals of the incremental sensor being used to determine the position of the part as well as to determine the jamming of the part, for example, via an evaluation of the rotational speed change.
The switching strip lends itself as second sensor system because it monitors the end position of the adjustable part in an economical manner.
Owing to a combination of the two sensor elements in the present invention, an anti-jam system is realized which, on the one hand, is economical and, on the other hand, enhances safety and reduces faulty triggering.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described in greater detail below by way of reference to the accompanying drawings, wherein:
FIG. 1 shows the apparatus and the division of the position regions; and
FIG. 2 schematically illustrates the functioning of the apparatus.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, starting from an open state, a part 11, for example, a window, first traverses the second position region 24 in the direction x until it gets into the first position region 23 at a region boundary 22. In the closed state, the part is disposed in the end position 21 which is a part of a frame 20 and is preceded by a switching strip 12.
In FIG. 2, an adjusting drive 10 moves the part 11. An incremental sensor 13 emits an incremental signal 15 to a control arrangement 14 which includes an anti-jam evaluating unit 17. A switching strip 12 emits a switching strip signal 16 to the control arrangement which exchanges signals with the adjusting drive 10. The desired operating mode is communicated to the control arrangement 14 via an operating unit 18.
The arrangement illustrated in FIGS. 1 and 2 functions as follows:
The incremental sensor 13 supplies incremental signals 15. These incremental signals 15 are added or subtracted in a manner that depends on the direction of rotation, for example, via a counter. The counter reading is a measure for the position in which the part 11 is disposed at that time. A Hall sensor, for example, is used as incremental sensor 13; it emits signals as a function of the magnetic ring division and the rotor position of the electric motor, of adjusting drive 10. In another embodiment, an evaluation of the waviness (ripple count, i.e., a count of peaks or periods) of the armature current of the electric motor serves to detect the position. In addition to detecting the position of the part 11, the control arrangement 14 also determines the rotational speed and thus the speed of the part by means of a time evaluation of the incremental signals 15. The actual rotational speed is continuously compared with a rotational limit speed; if the actual speed remains under the rotational limit speed, it is recognized that the part 11 is jammed. The rotational limit speed can be changed as a function of the position.
The switching strip 12 is known from DE-A 43 18 448. The switching strip signal 16 becomes logical one when the switching strip 16 is pressed.
Starting from the open state, the closing of the side window, for example, is communicated via the operating unit 18 of the control arrangement 14. The adjusting drive 10 is actuated by the control arrangement 14 in such a manner that it moves the part 11 in the closing direction. A comparison is carried out continuously to determine whether the part 11 is still disposed within the second position region 24 in that the counter reading as a measure of the present position does not yet exceed or fall below a parameterizable region boundary 22 (by "parameterizable" it is meant that the region boundary 22 may be selected based on specific parameters and corresponding to respective requirements). As long as the part 11 is disposed within the second position region 24, the anti-jam system responds when the incremental sensor 13 and the switching strip both detect a jam. This reduces the probability of faulty triggering. When the anti-jam system is triggered, the adjusting drive 10 is either stopped or reversed.
In a further embodiment, a third position region could now follow which is traversed by the part during the closing process. In the third position region, the anti-jam system only responds when the switching strip 12 indicates a jam.
In the application according to FIG. 1, the part 11 gets into the first position region 23 after traversing the second position region 24 and after crossing the region boundary 22. In this first position region which, for example, for a side window begins 10 cm ahead of the closing position, higher safety requirements must be met. The anti-jam system responds either when the switching strip 12 detects a jam or when a recognition of a jam is present which was derived from the rotational speed of the adjusting drive 10. This reduces the risk of persons getting caught.
The present invention has been described in detail with respect to preferred embodiments. It will be apparent from the foregoing to those skilled in the art that changes and modifications may be made without departing from the present invention. In its broader aspects, the present invention, as defined in the appended claims, is intended to cover all such changes and modifications within the true spirit of the invention. | An apparatus for electronically monitoring an adjusting drive controlling a moving part in a vehicle is proposed wherein a position-dependent anti-jam system is realized. The signals of a switching strip and of an incremental sensor are considered in different manners, depending on the position of the moving part. | 4 |
[0001] The present application is a 37 C.F.R. §1.53(b) continuation of U.S. patent application Ser. No. 12/985,389 filed on Jan. 6, 2011, which is a 37 C.F.R. §1.53(b) continuation of U.S. patent application Ser. No. 12/639,872 filed on Dec. 16, 2009, now U.S. Pat. No. 7,930,910 B2, which is a 37 C.F.R. §1.53(b) continuation of U.S. patent application Ser. No. 12/267,457 filed Nov. 7, 2008, currently pending, which is a 37 C.F.R. §1.53(b) continuation of U.S. patent application Ser. No. 10/461,451 filed Jun. 16, 2003, now U.S. Pat. No. 7,533,548 B2, which claims priority to Korean Patent Application No. 85521/2002, filed Dec. 27, 2002, the entire contents of which are hereby incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a drum type washing machine, and more particularly, to a drum type washing machine which can maximize a capacity of a drum without changing an entire size of a washing machine.
[0004] 2. Description of the Related Art
[0005] FIG. 1 is a side sectional view showing a drum type washing machine in accordance with the conventional art, FIG. 2 is a front sectional view showing the drum type washing machine in accordance with the conventional art.
[0006] The conventional drum type washing machine comprises: a cabinet 102 for forming an appearance; a tub 104 arranged in the cabinet 102 for storing washing water; a drum 106 rotatably arranged in the tub 104 for washing and dehydrating laundry; and a driving motor 110 positioned at a rear side of the tub 104 and connected to the drum 106 by a driving shaft 108 thus for rotating the drum 106 .
[0007] An inlet 112 for inputting or outputting the laundry is formed at the front side of the cabinet 102 , and a door 114 for opening and closing the inlet 112 is formed at the front side of the inlet 112 .
[0008] The tub 104 of a cylindrical shape is provided with an opening 116 at the front side thereof thus to be connected to the inlet 112 of the cabinet 102 , and a balance weight 118 for maintaining a balance of the tub 104 and reducing vibration are respectively formed at both sides of the tub 104 .
[0009] Herein, a diameter of the tub 104 is installed to be less than a width of the cabinet 102 by approximately 30-40 mm with consideration of a maximum vibration amount thereof so as to prevent from being contacted to the cabinet 102 at the time of the dehydration.
[0010] The drum 106 is a cylindrical shape of which one side is opened so that the laundry can be inputted, and has a diameter installed to be less than that of the tub 104 by approximately 15-20 mm in order to prevent interference with the tub 104 since the drum is rotated in the tub 104 .
[0011] A plurality of supporting springs 120 are installed between the upper portion of the tub 104 and the upper inner wall of the cabinet 102 , and a plurality of dampers 122 are installed between the lower portion of the tub 104 and the lower inner wall of the cabinet 102 , thereby supporting the tub 104 with buffering.
[0012] A gasket 124 is formed between the inlet 112 of the cabinet 102 and the opening 116 of the tub 104 so as to prevent washing water stored in the tub 104 from being leaked to a space between the tub 104 and the cabinet 102 . Also, a supporting plate 126 for mounting the driving motor 110 is installed at the rear side of the tub 104 .
[0013] The driving motor 110 is fixed to a rear surface of the supporting plate 126 , and the driving shaft 108 of the driving motor 110 is fixed to a lower surface of the drum 106 , thereby generating a driving force by which the drum 106 is rotated.
[0014] In the conventional drum type washing machine, the diameter of the tub 104 is installed to be less than the width of the cabinet 102 with consideration of the maximum vibration amount so as to prevent from being contacted to the cabinet 102 , and the diameter of drum 106 is also installed to be less than that of the tub 104 in order to prevent interference with the tub 104 since the drum is rotated in the tub 104 . According to this, so as to increase the diameter of the drum 106 which determines a washing capacity, a size of the cabinet 102 has to be increased.
[0015] Also, since the gasket 124 for preventing washing water from being leaked is installed between the inlet 112 of the cabinet 102 and the opening 116 of the tub 104 , a length of the drum 106 is decreased as the installed length of the gasket 124 . According to this, it was difficult to increase the capacity of the drum 106 .
SUMMARY OF THE INVENTION
[0016] Therefore, an object of the present invention is to provide a drum type washing machine which can increase a washing capacity without changing an entire size thereof, in which a cabinet and a tub is formed integrally and thus a diameter of a drum can be increased without increasing a size of the cabinet.
[0017] Another object of the present invention is to provide a drum type washing machine which can increase a washing capacity by increasing a length of a drum without increasing a length of a cabinet, in which the cabinet and a tub are formed integrally and thus a location of a gasket is changed.
[0018] To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a drum type washing machine comprising: a cabinet for forming an appearance; a tub fixed to an inner side of the cabinet and for storing washing water; a drum rotatably arranged in the tub for washing and dehydrating laundry; and a driving motor positioned at the rear side of the drum for generating a driving force by which the drum is rotated.
[0019] The tub is a cylindrical shape, and a front surface thereof is fixed to a front inner wall of the cabinet.
[0020] Both sides of the tub are fixed to both sides inner wall of the cabinet.
[0021] A supporting plate for mounting the driving motor is located at the rear side of the tub, and a gasket hermetically connects the supporting plate and the rear side of the tub, in which the gasket is formed as a bellows and has one side fixed to the rear side of the tub and another side fixed to an outer circumference surface of the supporting plate.
[0022] A supporting unit for supporting an assembly composed of the drum, the driving motor, and the supporting plate with buffering is installed between the supporting plate and the cabinet.
[0023] The supporting unit comprises: a plurality of upper supporting rods connected to an upper side of the supporting plate towards an orthogonal direction and having a predetermined length; buffering springs connected between the upper supporting rods and an upper inner wall of the cabinet for buffering; a plurality of lower supporting rods connected to a lower side of the supporting plate towards an orthogonal direction and having a predetermined length; and dampers connected between the lower supporting rods and a lower inner wall of the cabinet for absorbing vibration.
[0024] The drum is provided with a liquid balancer at a circumference of an inlet thereof for maintaining a balance when the drum is rotated.
[0025] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.
[0027] In the drawings:
[0028] FIG. 1 is a side sectional view showing a drum type washing machine in accordance with the conventional art;
[0029] FIG. 2 is a front sectional view showing the drum type washing machine in accordance with the conventional art;
[0030] FIG. 3 is a side sectional view showing a drum type washing machine according to one embodiment of the present invention;
[0031] FIG. 4 is a front sectional view showing the drum type washing machine according to one embodiment of the present invention;
[0032] FIG. 5 is a lateral view showing a state that a casing of the drum type washing machine according to one embodiment of the present invention is cut;
[0033] FIG. 6 is a front sectional view of a drum type washing machine according to a second embodiment of the present invention;
[0034] FIG. 7 is a front sectional view showing a drum type washing machine according to a third embodiment of the present invention;
[0035] FIG. 8 is a longitudinal sectional view of the drum type washing machine according to the third embodiment of the present invention; and
[0036] FIG. 9 is a rear sectional view showing the drum type washing machine according to the third embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
[0038] FIG. 3 is a side sectional view showing a drum type washing machine according to one embodiment of the present invention, and FIG. 4 is a front sectional view showing the drum type washing machine according to one embodiment of the present invention.
[0039] The drum type washing machine according to one embodiment of the present invention comprises: a cabinet 2 for forming an appearance of a washing machine; a tub 4 formed integrally with the cabinet 2 and for storing washing water; a drum 6 rotatably arranged in the tub 4 for washing and dehydrating laundry; and a driving motor 8 positioned at the rear side of the drum 6 for generating a driving force by which the drum 6 is rotated.
[0040] The cabinet 2 is rectangular parallelepiped, and an inlet 20 for inputting and outputting laundry is formed at the front side of the cabinet 2 and a door 10 for opening and closing the inlet 20 is formed at the inlet 20 .
[0041] The tub 4 is formed as a cylinder shape having a predetermined diameter in the cabinet 2 , and the front side of the tub 4 is fixed to the front inner wall of the cabinet 2 or integrally formed at the front inner wall of the cabinet 2 . Both sides of the tub 4 are contacted to both sides inner wall of the cabinet 2 or integrally formed with both sides inner wall of the cabinet 2 thus to be prolonged.
[0042] Herein, since both sides of the tub 4 are contacted to both sides inner wall of the cabinet 2 , a diameter of the tub 4 can be increased.
[0043] Also, the supporting plate 12 is positioned at the rear side of the tub 4 and the gasket 14 is installed between the supporting plate 12 and the rear side of the tub 4 , thereby preventing washing water filled in the tub 4 from being leaked.
[0044] The gasket 14 is formed as a bellows of a cylinder shape and has one side fixed to the rear side of the tub 4 and another side fixed to an outer circumference surface of the supporting plate 12 .
[0045] The supporting plate 12 is formed as a disc shape, the driving motor 8 is fixed to the rear surface thereof, and a rotation shaft 16 for transmitting a rotation force of the driving motor 8 to the drum 6 is rotatably supported by the supporting plate 12 . Also, a supporting unit for supporting the drum 6 with buffering is installed between the supporting plate 12 and the inner wall of the cabinet 2 .
[0046] The supporting unit comprises: a plurality of upper supporting rods 22 connected to an upper side of the supporting plate 12 and having a predetermined length; buffering springs 24 connected between the upper supporting rods 22 and an upper inner wall of the cabinet 2 for buffering; a plurality of lower supporting rods 26 connected to a lower side of the supporting plate 12 and having a predetermined length; and dampers 28 connected between the lower supporting rods 26 and a lower inner wall of the cabinet 2 for absorbing vibration.
[0047] Herein, the buffering springs 24 and the dampers 28 are installed at a center of gravity of an assembly composed of the drum 6 , the supporting plate 12 , and the driving motor 8 . That is, the upper and lower supporting rods 22 and 26 are prolonged from the supporting plate 12 to the center of gravity of the assembly, the buffering springs 24 are connected between an end portion of the upper supporting rod 22 and the upper inner wall of the cabinet 2 , and the dampers 28 are connected between an end portion of the lower supporting rod 26 and the lower inner wall of the cabinet 2 , thereby supporting the drum 6 at the center of gravity.
[0048] A diameter of the drum 6 is installed in a range that the drum 6 is not contacted to the tub 4 even when the drum 6 generates maximum vibration in order to prevent interference with the tub 4 at the time of being rotated in the tub 4 .
[0049] Operations of the drum type washing machine according to the present invention are as follows.
[0050] If the laundry is inputted into the drum 6 and a power switch is turned on, washing water is introduced into the tub 6 . At this time, the front side of the tub 6 is fixed to the cabinet 2 and the gasket 14 is connected between the rear side of the tub 6 and the supporting plate 12 , thereby preventing the washing water introduced into the tub 6 from being leaked outwardly.
[0051] If the introduction of the washing water is completed, the driving motor 8 mounted at the rear side of the supporting plate 12 is driven, and the drum 6 connected with the driving motor 8 by the rotation shaft 16 is rotated, thereby performing washing and dehydration operations. At this time, the assembly composed of the drum 6 , the driving motor, and the supporting plate 12 is supported by the buffering springs 24 and the dampers 28 mounted between the supporting plate 12 and the inner wall of the cabinet 20 .
[0052] FIG. 6 is a front sectional view of a drum type washing machine according to a second embodiment of the present invention.
[0053] The drum type washing machine according to the second embodiment of the present invention has the same construction and operation as that of the first to embodiment except a shape of the tub.
[0054] That is, the tub 40 according to the second embodiment has a straight line portion 42 with a predetermined length at both sides thereof. The straight line portion 42 is fixed to the inner wall of both sides of the cabinet 2 , or integrally formed at the wall surface of both sides of the cabinet 2 .
[0055] Like this, since the tub 40 according to the second embodiment has both sides fixed to the cabinet 2 as a straight line form, the diameter of the tub 40 can be increased. Accordingly, the diameter of the drum 6 arranged in the tub 40 can be more increased.
[0056] FIG. 7 is a front sectional view showing a drum type washing machine according to a third embodiment of the present invention, FIG. 8 is a longitudinal sectional view of the drum type washing machine according to the third embodiment of the present invention, and FIG. 9 is a rear sectional view showing the drum type washing machine according to the third embodiment of the present invention.
[0057] The drum type washing machine according to the third embodiment of the present invention comprises: a cabinet 2 for forming an appearance of a washing machine; a tub 50 formed integrally with the cabinet 2 and for storing washing water; a drum 6 rotatably arranged in the tub 50 for washing and dehydrating laundry; and a supporting unit positioned at the rear side of the tub 50 and arranged between the supporting plate 12 to which the driving motor 8 is fixed and the cabinet 2 for supporting the drum 6 with buffering.
[0058] The tub 50 is composed of a first partition wall 52 fixed to the upper front inner wall and both sides inner wall of the cabinet 2 ; and a second partition wall 54 integrally fixed to the lower front inner wall and both sides inner wall of the cabinet 2 .
[0059] The first partition wall 52 of a flat plate shape is formed at the upper side of the cabinet 2 in a state that the front side and both sides are integrally formed at the inner wall of the cabinet 2 or fixed thereto. Also, the second partition wall 54 of a semi-circle shape is formed at the lower side of the cabinet 2 in a state that the front side and both sides are integrally formed at the inner wall of the cabinet 2 or fixed thereto.
[0060] The supporting unit comprises: a plurality of upper supporting rods 56 connected to the upper side of the supporting plate 12 and having a predetermined length; buffering springs 58 connected between the upper supporting rods 56 and the upper inner wall of the cabinet 2 for buffering; a plurality of lower supporting rods 60 connected to the lower side of the supporting plate 12 and having a predetermined length; and dampers 62 connected between the lower supporting rods 60 and the lower inner wall of the cabinet 2 for absorbing vibration.
[0061] Herein, the upper supporting rods 56 are bent to be connected to the upper side of the supporting plate 12 and positioned at the upper side of the first partition wall 52 , and the buffering springs 58 are connected to the end portion of the upper supporting rods 56 . Also, the lower supporting rods 60 are bent to be connected to the lower side of the supporting plate 12 and positioned at the lower side of the second partition wall 54 , and the dampers 62 are connected to the end portion of the lower supporting rods 56 .
[0062] In the drum type washing machine according to the present invention, a size of the drum can be maximized by fixing the tub in the cabinet, thereby increasing washing capacity of the drum without increasing a size of the cabinet.
[0063] Also, since the front surface of the tub is integrally formed at the inner wall of the cabinet and the gasket is installed between the rear surface of the tub and the supporting plate, a length of the drum can be increased and thus the washing capacity of the drum can be increased.
[0064] As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalence of such metes and bounds are therefore intended to be embraced by the appended claims. | A drum type washing machine is provided. The drum type washing machine may include a cabinet, a tub fixed to an inner side of the cabinet, a drum rotatably arranged in the tub, and a driving motor positioned at a rear side of the drum for generating a driving force that rotates the drum. The washing machine may also include a supporting plate to rotatably support a rotational shaft extending between the motor and the drum, and a plurality of supporters connected between the supporting plate and the cabinet. Such an arrangement may increase washing capacity by increasing a diameter of the drum without increasing an external size of the cabinet. | 3 |
BACKGROUND OF THE INVENTION
[0001] (1) Field of the Invention
[0002] The invention relates to heating ventilation and air conditioning (HVAC) systems. More particularly, the invention relates to fans for such systems.
[0003] (2) Description of the Related Art
[0004] Fans are ubiquitous in HVAC systems. Many fan configurations exist. A typical electric fan includes a motor having a shaft protruding from one end. A fan assembly is mounted to the shaft so as to be driven by the motor. One group of fan assembly configurations involves molding a plastic component over a metallic hub insert. The plastic component includes a hub surrounding the insert and blades radiating outward from the hub. The plastic component may further include a shroud at outboard ends of the blades. In such configurations, the use of plastic generally provides lightness and ease of manufacturing and the use of a metallic insert provides a robust precise connection to the motor shaft. The engineering of the insert and its interface with the plastic component presents a number of considerations. The insert may, advantageously, be light. The insert requires an appropriate robust interface with the plastic component to reliably transmit torque and thrust. Various forms of fluting and other complex surface configurations have been proposed to achieve advantageous performance.
SUMMARY OF THE INVENTION
[0005] One aspect of the invention is a fan assembly. A central metallic element has a central longitudinal aperture and a lateral surface. A polymeric fan has a hub carrying a central metallic element and a number of blades extending from the hub. The central metallic element lateral surface is of substantially uniform, substantially square section along a majority of a length of the central metallic element.
[0006] In various implementations, the central metallic element lateral surface may have a groove. The central metallic element may consist essentially of brass or bronze. The central metallic element may have a pair of off-center threaded bores open to a forward end of the central metallic element. The central metallic element longitudinal aperture may include a keyway extending from a central circular-section bore. A polymeric cover may be secured at a forward end of the hub. The polymeric fan may further include a shroud, unitarily formed with the blades. A web portion of the polymeric fan may overlie a perimeter portion of an aft surface of the central metallic member. The fan assembly may be combined with a motor. The motor may have a shaft having a portion accommodated within the central longitudinal aperture and secured to the central metallic element against rotation. A stator may be coupled to the shaft so as to drive the fan.
[0007] The fan assembly may be manufactured by cutting a precursor of the central metallic element from a square-section bar. The central longitudinal aperture may be machined. A recess may be machined in the lateral surface. The fan may be molded over the central metallic element so that material of the fan enters the recess. The central metallic element may be first mounted in a mold for the molding of the fan.
[0008] Another aspect of the invention involves a method for remanufacturing an electric fan. A first fan assembly is removed from a motor. The first fan assembly includes a first central metallic element having a first central longitudinal aperture and a first lateral surface. The first fan assembly further includes a first polymeric fan having a first hub carrying the first central metallic member. A second fan assembly may be installed to the motor. The second fan assembly includes a second central metallic element having a second central longitudinal aperture and a second lateral surface. The second fan assembly includes a second polymeric fan having a second hub carrying the second central metallic element. The second lateral surface is of substantially uniform, substantially square section along a majority of a length of the second central metallic element.
[0009] In various implementations, the second metallic element may be heavier than the first metallic element (e.g., by at least 5%, 10%, 25%, or more). The first metallic element may have a more complex shape than the second metallic element (e.g., in principal transverse section).
[0010] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a partially exploded view of a pair of electric fan units.
[0012] FIG. 2 is a view of a fan assembly of one of the units of FIG. 1 .
[0013] FIG. 3 is a partial longitudinal sectional view of the fan assembly of FIG. 2 .
[0014] FIG. 4 is a front end view of an insert of the fan assembly of FIG. 2 .
[0015] FIG. 5 is a longitudinal sectional view of the insert of FIG. 4 , taken along line 5 - 5 .
[0016] Like reference numbers and designations in the various drawings indicate like elements.
DETAILED DESCRIPTION
[0017] FIG. 1 shows a pair of electric fan units 20 mounted from a duct component 22 of an HVAC system. Each fan unit includes an electric motor 24 having a shaft 26 with a portion protruding from the housing or case 28 containing a stator (not shown). In operation, the motor shaft is driven about a common central longitudinal axis 500 of the fan unit. The fan unit further includes a fan assembly 30 mounted to the protruding portion of the shaft.
[0018] In the exemplary embodiment, each fan unit is mounted to the duct assembly by a pair of mounting brackets 32 . In the exemplary embodiment, each fan assembly 30 is concentrically mounted within an annular cylindrical duct 40 extending from a proximal end at a flat wall 42 to a distal end carrying a grill 44 . Other configurations are possible.
[0019] FIGS. 2 and 3 show further details of the exemplary fan assembly 30 . The fan assembly 30 includes the combination of a molded plastic component 50 ( FIG. 2 ) and a metallic insert 52 ( FIG. 3 ). The metallic insert is at least partially embedded in a hub portion 54 of the molded component from which unitarily-formed blades 56 radiate outward from inboard root ends at a sidewall 57 of the hub. In the exemplary embodiment, the molded component further includes an annular shroud 58 at the blade outboard ends. The metallic insert includes a central longitudinal aperture 60 for receiving the protruding end of the motor shaft. The exemplary central aperture 60 extends between first (front) and second (rear) end surfaces 62 and 64 of the metallic insert and consists essentially of a right circular cylindrical bore 66 ( FIG. 4 ) coaxial with the fan axis and a slot-like keyway 68 extending radially outward from at least a portion of the bore. The keyway receives a portion of a key 70 ( FIG. 1 ) of which a second portion is similarly received in a keyway in the shaft to lock the metallic insert to the shaft against relative rotation. A screw, bolt, or similar fastener 71 ( FIG. 1 ) may have a threaded shaft extending into a threaded aperture in the motor shaft and a head bearing against (e.g., via a washer) the front surface 62 to prevent unintended longitudinal ejection of the fan.
[0020] The metallic insert 52 has a lateral surface characterized by four facets 72 ( FIG. 4 ) defining a square cross-section. The square cross-section may correspond to bar stock (e.g., brass) from which the insert is cut. In the exemplary embodiment, to improve longitudinal engagement between the insert and the molded component, there may be one or more recesses 74 ( FIG. 5 ) in the lateral surface. An exemplary recess comprises a near-right annular channel having a circular cylindrical base 76 and a pair of near-radial sidewalls 78 and 80 with slightly radiused transitions. Additionally, the exemplary embodiment includes a pair of blind threaded bores 82 extending longitudinally inward from the front surface 62 . The bores 82 are off-center and aid in fan extraction from the motor/shaft as is discussed in further detail below.
[0021] In an exemplary process of manufacture, insert precursors are cut from square-section bar stock. The cutting (which may include one or more stages such as rough cutting and surface milling) essentially defines the end surfaces and the principal portion of the lateral surface. The cut precursor may be fixtured (e.g., in a lathe or similar tool) and the central bore 66 drilled and the channel 74 cut. The precursor may then be refixtured for milling the keyway 68 and again refixtured for drilling and tapping the bores 82 .
[0022] After the insert has been formed, it may be registered in a portion of a die (not shown) for molding the molded component 50 . The die may be assembled and plastic (e.g., glass-reinforced polypropylene) injected to form the molded component. The exemplary molding nearly entirely embeds the insert within the hub. In the exemplary embodiment, webs 84 and 86 ( FIG. 3 ) of the molded material extend along outboard portions of the insert ends 62 and 64 , having apertures therein to expose the channel at both ends and bores at the front end 62 . The apertures advantageously extend sufficiently radially beyond the channel to permit engagement of the fastener 71 to the front end 62 (e.g., by accommodating a washer) and engagement of a shoulder on the motor shaft with the aft end 64 so as to longitudinally clamp the insert (e.g., via direct compressive contact). With the motor preinstalled in the appropriate environmental structure, the combination of the molded component and insert may be installed to the shaft (e.g., by sliding the insert over the shaft 26 and key 70 and installing the fastener 71 and/or by press/interference fitting). Thereafter, a cover (e.g., also molded plastic such as unreinforced polypropylene) 88 ( FIG. 3 ) may be placed over the hub (e.g., via snap fit within a perimeter of the hub).
[0023] To remove the fan assembly from the motor, the hub cover may first be removed from the hub (e.g., by disengaging the snap fit via prying or other extraction). The fastener 71 may then be removed by unthreading. A removal tool (not shown) may be installed to the hub assembly. An exemplary removal tool includes threaded shafts (not shown) threaded into engagement with the bores 82 and retained by a tool body structure spanning such shafts. A central jack screw (not shown) may extend longitudinally between and parallel to the threaded shafts and may be rotated until its distal end contacts the motor shaft front end, with further rotation extracting the fan assembly from the motor shaft via a jacking action.
[0024] For the insert, square bar stock is relatively inexpensive source material (e.g., as compared with stock of more convoluted section). By limiting subsequent machining so as to leave a major portion of the cross-section intact, subsequent manufacturing costs are reduced (e.g., as compared with machining a complex profile such as fluting along a greater portion of the length of the insert). Thus, the present teachings may be used to form a less complex and less expensive insert than would otherwise be used. Relative to such a more complex insert, the alternative insert may be larger in cross-sectional area and thus greater in weight and may have a slightly less robust anti-torque engagement with the hub. Nevertheless, the square section may provide sufficient anti-torque engagement and the increased mass may slightly, if not negligibly, affect inertia (especially due to the relatively small radius at which most of the insert's mass exists). Accordingly, the present teachings may be used to design an insert to replace a more complex (and expensive) insert either for engineering the configuration of a new electric fan based upon an existing electric fan or as a remanufacturing of the existing electric fan.
[0025] One or more embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, when implemented as a reengineering or remanufacturing of an existing electric fan, details of the existing fan may influence details of any particular implementation. Accordingly, other embodiments are within the scope of the following claims. | A fan assembly has a central metallic element and a polymeric fan. The polymeric fan has a hub carrying the central metallic element and has a plurality of blades extending from the hub. The central metallic element has a central longitudinal aperture and a lateral surface. The central metallic element lateral surface is of substantially uniform substantially square section along a majority of a length of the central metallic element. | 5 |
This is a continuation of application Ser. No. 07/173,642, filed on Mar. 25, 1988 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a pressure infusion device, and in particular a pressure infusion device for squeezing out a syringe.
2. Description of Related Art
In the case of pressure infusion devices used for carrying out infusions of a liquid into a patient, a syringe containing a liquid is squeezed out continuously, the squeezed out liquid being supplied through a hose to the patient. A known pressure infusion device (U.S. Pat. No. 4,465,475) has an elongated tubular housing to which a first holder is secured for supporting the syringe cylinder. The housing contains a spindle drive and, out of its one end, there extends a slide displaceable along the housing axis and provided with a second holder adapted to be applied to the syringe ram. By rotating a spindle arranged in the housing, the slide is linearly displaced relative to the housing, whereby the syringe mounted in the pressure infusion device is squeezed out. The drive of the advance system is effected by an electric motor.
It has also been known to provide limit switches or early alarm switches at the pressure infusion device. The switches are responsive if a predetermined advance position is reached, so that an alarm is generated or the device is turned off if the syringe is empty or nearly empty. However, an additional expenditure is involved with such limit switches, and, furthermore, a regular check of their perfect functioning is necessary.
The known pressure infusion devices must comply with high precision requirements concerning the advance means and the electric drive, because their total working operation is preset to subsequently take place without being monitored. Therefore, once an infusion rate is set, it must be ensured that the infusion rate is maintained exactly for further operation. In addition, deviations due to manufacturing irregularities and variations in units must not be substantial.
It is an object of the present invention to provide a pressure infusion device in which the total infusion operation is monitored and controlled by ensuring that the infusion conditions are strictly observed.
SUMMARY OF THE INVENTION
In a preferred embodiment of the pressure infusion apparatus of the present invention, the total shift path of the advance means or of the movable holder by which the syringe is squeezed out is monitored by a path sensor. The position data are signaled to the control means, which performs position control in response to a predetermined program or to external measuring data. Thus, the squeezing condition of the syringe is monitored in each stage and signaled to the control means. The control means detects whether the respective position value corresponds to the desired position provided at each moment and makes corrections, if necessary, to temporarily increase or decrease the advance speed. Therefore, it is possible to change, in a time-controlled or quantity-controlled manner, the infusion rate in accordance with a schedule by first setting, for instance, a high infusion rate which will be subsequently reduced continuously. On the other hand, the advance may be also controlled in response to external measuring data which, for instance, are conclusive as to the effect of the infused medication. If a hypotensive preparation is administered, the infusion rate may be varied subject to the instantaneous blood pressure of the patient.
It is a particular advantage of the present invention that not only specific infusion rates may be preset, but also that adherence to said infusion rates may be monitored exactly and signaled to the control means. Probable deviations may be compensated by using known control criteria.
Preferably, the path sensor is of the absolute value type, which, with respect to a fixed reference position, detects the position of a second holder moving the syringe rod. Since the respective absolute position of the second holder is detected, and the empty-state position of the second holder (in which the syringe is completely squeezed out) is a predetermined position, no limit switches are required for generating an early alarm or for the limit disconnection of the drive. The empty-state position for each syringe type may be input manually into an input means of the control means. Further, the empty-state position may be input in that the syringe is mounted in empty condition into the pressure infusion device. By depressing a push-button, the respective position of the second holder may be stored in the control means. Subsequently, the syringe may be charged in that the piston is withdrawn in the cylinder. The resultant position of the second holder provides information (with due regard to the syringe cross section) about the liquid volume charged by the syringe.
Further, the control means may monitor the syringe to detect blocking of the infusion operation. If the tube adapted to the syringe is, for instance, bent, and a further advance is inhibited (although the empty-state position has not yet been reached), this may be detected in that the syringe advance is slower than a predetermined value, thus requiring the release of an alarm. Hence, for detecting a blocking of the infusion, it is not necessary to provide load measuring means.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to one sole FIGURE of the drawing, an embodiment of the invention will be explained hereunder in more detail.
The drawing shows a schematic longitudinal section of a pressure infusion device.
Said pressure infusion device comprises a housing 10 accommodating a motor-gear unit 11 which drives, via gears 12 and 13, a shaft 14 that, through coupling 15, is connected to one end of the threaded spindle 16. In the vicinity of said end, said threaded spindle 16 is supported by a bearing 17 in the wall of housing 10. The threaded spindle 16 projects out of the housing 10, and its opposite end is positioned with a bearing 18 in a block 19 which, via a (non-illustrated) bridge is integrated with housing 10. On the threaded spindle 16, a slide 20 in the form of a spindle nut is guided. Its inner thread engages the external thread of the threaded spindle 16. Said slide 20 is retained against rotation so that, in the case of a rotation of the threaded spindle 16, it moves in the longitudinal direction of the threaded spindle. Elements 11 to 20 comprise a preferred embodiment of the advance means which, alternatively, may be also designed like that of the pressure infusion device according to U.S. Pat. No. 4,465,475.
To the housing 10, the first holder 21 is fixed in which the neck of the syringe cylinder 23 of syringe 22 provided. The end of the syringe rod 24 is placed into the second holder 25, which is integrally connected to the slide 20. In the syringe cylinder 23, the syringe 22 contains a piston 26 joined firmly to the rod 24 and expelling the fluid contained in the syringe out of the outlet 27, to which a tube may be connected.
According to a preferred embodiment of the invention, a path sensor 28 is provided to detect the axial position of the slide 20 with respect to the housing 10 or with respect to the first holder 21. The path sensor 28 comprises an encoded rail 29 extending between housing 10 and block 19, as well as a scanning head 30 movable along rail 29 and integrally connected to the second holder 25. The scanning head 30 is provided with a plurality of sensors, with each sensor being adapted to be moved along a signal track of the signal rail 29. The signal rail 29 comprises signal tracks which may be scanned magnetically or optically. From the combination of the signals of the sensors contained in scanning head 30, information may be obtained about the position of the scanning head 30 in the longitudinal direction of the signal rail 29. As for details, the model 500 position sensor manufactured by the MITUTOYO company may be used as the position sensor 28. The resolution of such a position sensor is approximately 0.01 mm.
The output signals of the scanning head 30, which represent the position signals of the second holder 25, are supplied to the control means 31. The control means 31 accommodates a microprocessor which, responsive to the position signals, controls the motor of the motor-gear unit 11. By a keyboard 31a of the control means 31, various parameters of the infusion operation may be input into the microprocessor, such as, for instance the inner cross section of the syringe cylinder 23, the liquid volume contained in the syringe and the empty-state position of the syringe (i.e., the position occupied by holder 25 if the syringe is completely squeezed out). Moreover, the desired infusion rate, namely the liquid volume to be squeezed out per time unit, may be input. It is also possible to input a number of different infusion rates which shall become effective successively during one and the same infusion process. From the inputted data, the microprocessor calculates the respective infusion rate. By timing, it is detected whether the respective actual infusion rate corresponds to the desired one. The speed of the motor is corrected responsive to the resultant deviation.
The control performed by the device 31 may be carried out either by means of the path data inputted and supplied by the scanning head 28, or by means of the volume data which form the product of path and cross sectional surface of the syringe cylinder 23.
The display means 31b of the control means 31 may indicate the fluid volume already squeezed out of the syringe, or the fluid volume still contained in it. Further, the still available infusion time may be displayed.
The empty-state position occupied by scanning head 30 or by the second holder 25 if the syringe 22 is completely squeezed out may be either input manually by keyboard 31a, or it may be input in that an empty syringe not containing any fluid, is inserted with advanced piston into holders 21 and 25. The position taken by the holder 25 in such a condition is stored in the control means 31 by depressing a respective key. Subsequently, the pressure infusion device may be used to charge liquid into the syringe 22 in that the slide 20 withdraws rod 24. Upon termination of the charging process, the position value of the scanning head 30 is also stored in the control means 31. Thus, the control means contains instructions about the volume of the charged liquid in the syringe.
On the other hand, it is possible to use and squeeze out under control a syringe of known dimensions which are stored in the control means 31.
Upon reaching a position which, by a specific distance, is in advance of the empty state position of the syringe, an alarm is released by the control means 31 to alert the staff that the infusion process will be shortly terminated so that, if necessary, a new syringe may be applied. The position in which the early alarm is released may be so selected that a specific residual infusion time is left. In such a case, the position at which early alarm is triggered, varies subject to the advance speed.
Moreover, device 31 controls that the advance speed or the infusion rate do not fall short of a predetermined minimum value. If the latter is not reached (for instance because the tube connected to the syringe 22 is kinked or closed for other reasons), the control means detects the insufficient minimum speed and an alarm is released.
One sole control means may be operated in connection with a plurality of pressure infusion devices of which each contains a path sensor 28. It is possible in this way to intercoordinate the pressure infusion devices. This is suitable if a number of infusions must be administered simultaneously and in specific amount ratios to a patient. If a pressure infusion device does not work properly, all pressure infusion devices may be turned off. But it is also possible to operate them such that by adhering exactly to a specific, predetermined ratio of amounts, the infusion solutions are administered to the patient. One of several pressure infusion devices may be also used as a master unit while the remaining devices, in accordance with the path signals generated by the path sensor of the master unit, may serve as follow-up units.
Due to the pressure infusion device of the present invention, even the smallest amounts of liquid may be very precisely dosed and applied from an optionally high volume. The accuracy requirements concerning the advance means and the drive are very moderate because the high accuracy of the system is obtained by the path sensor. | A pressure infusion device for squeezing out a syringe having an absolute path sensor connected to the movable holder and supplying position data of the position of the syringe rod to a control means. Based on the position data, a motor is controlled so that a desired infusion rate is maintained. The infusion rate may be programmed to vary during an infusion process. Shortly before the empty-state position is reached, an early alarm is released, while, in reaching the empty-state position, the drive is turned off. | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The invention relates to the field of document presentation processing, wherein elements of electronic information (i.e., text or graphics) are gathered, associated, created, formatted, edited, prepared, and presented.
[0003] More particularly, the invention relates to a method of creating presentations by linking to relevant image sources.
[0004] 2. Description of Related Art
[0005] Several commercial databases of indexed web pages on the World Wide Web are available (for example, Google™, Altavista™, MSN™, etc.). Such databases, popularly known as search engines, are extremely popular and are used extensively by web users to search for relevant information. These days search engines are being used not only to search for textual information, but also for image information. For example, by entering appropriate keywords in a search box, “Google™ Images” will display a large collection of small-sized images to the user.
[0006] However, the limitation of the conventional way of searching for images on the search engines is that if the user finds a set of images matching his interests, he has no convenient option of saving the collection of images for his own later use or for forwarding the collection of images to his contacts. He could save the images one-by-one in a folder on his computer or he could save the images as a bookmark by clicking on each image and saving the URL as a bookmark. However, both these processes are extremely cumbersome. Saving the images one-by-one in a folder on his computer will consume a large memory space in the computer. The user can also not conveniently send the collection of images to his contacts by email, because of the heavy size of the image files. Saving the each image as a bookmark has the limitation that the logical connections and relationships between related images are not visible to the user.
[0007] Another limitation of the conventional way of searching for images on the search engines is that the images retrieved from, say “Google™ Images,” can not be conveniently organized into a meaningful collection. The information relating to each individual image has to be viewed by serially clicking the image. There is no convenient way to view all information related to the images without having to serially drill through each link.
[0008] Another limitation of the conventional way of searching for images on the search engines is that there is no convenient way to author and edit a presentation relating to a user's search interests. The conventional way also does not allow a user to annotate the images with his observations.
[0009] U.S. Pat. No. 4,716,404 discloses an image retrieval method and apparatus wherein for retrieval of a plurality of images, a sub-image of each image is specified and extracted, reference data such as memo data related to each sub-image is stored, and the sub-image and the memo data related thereto are combined and outputted as desired, thereby simplifying the retrieval of the plurality of images. Specifically, a sub-image, which is the most characteristic to each image, is extracted and combined with a memo data to thereby provide a clear clue to the image extraction. The number of specified sub-images is freely increased without rewriting original image data stored in an image file and image retrieval is settled by using a memo image and a cutout sub-image both having a less amount of data than the entire image, so that applications to a storage medium which is not rewritable, for example, an optical disc can be ensured with high response image display. However, this patent does not teach the combination of searching for images on the internet, authoring a slideshow presentation of images in real-time, and publishing the slideshow presentation to a web URL or to a database.
[0010] U.S. Pat. No. 4,829,453 discloses an apparatus for cataloging and retrieving image data is programmed to store not only image data obtained by scanning each original but also reduced image data obtained by thinning these image data and search data used for the convenience in search operations. In a search operation, a plurality of reduced image data may be displayed simultaneously or sequentially with corresponding search data. Image data may be stored in a compressed form so that an increased amount of data can be stored. The apparatus may be programmed such that stored reduced image data are sequentially displayed while a specified key is depressed and particular image data corresponding to the data displayed when the key is released are displayed. However, the patent does not teach the combination of searching for images on the internet, authoring a slideshow presentation of images in real-time, and publishing the slideshow presentation to a web URL or to a database.
[0011] U.S. Pat. No. 5,220,648 discloses software for electronically annotating electronic images, such as drawings, photographs, video, etc., through the drag-and-drop of annotations from a pre-defined, but extendable, list. The annotations are placed at a user-selected X, Y location on the image, and stored in a searchable database. Thus, they can be searched in order to retrieve, organize, group, or display desired electronic images or collections of such images. The annotations may be text, images, sounds, etc. The invention provides a flexible, easy to learn, rapid, low error rate and satisfying interface for accomplishing such tasks. However, the patent does not teach the combination of searching for images on the internet, authoring a slideshow presentation of images in real-time, and publishing the slideshow presentation to a web URL or to a database.
[0012] U.S. Pat. No. 6,859,909 discloses a system and method for annotating web-based documents. The invention allows computer users to integrate any annotation, including ink, highlighter, text-based notes and audio, directly into a Web-based document (WBD) displayed by a Web browser. This integration enables others to view the personalized annotated WBD, which retains its original active links and properties, over the Internet without the need for specialized software. Annotations are integrated into WBDs by freezing the WBD, overlaying an image file containing the annotations onto the WBD, and enabling browser events to pass through the image layer. Annotations may also be integrated into WBDs by using component object technology. The present invention collects and organizes annotated WBDs, and provides users with an intuitive Web-based interface for accessing, viewing and searching the annotated WBDs. Users may annotate blank WBDs, effectively converting their Web browsers into online notebooks/scrapbooks. The present invention also provides users with many novel interface techniques, such as dog-ears and its associated navigation tools, splitting pages, turning pages, selecting and copying various portions of a WBD (including shaking out a copy), and marking menus suited for right-handed or left-handed users. However, this patent does not teach the combination of searching for images on the internet, authoring a slideshow presentation of images in real-time, and publishing the slideshow presentation to a web URL or to a database.
[0013] U.S. Pat. No. 7,010,537 discloses a method and system for visual network searching, wherein search request is signaled over the network to a search engine. A search result is received that identifies a plurality of network addresses. Multiple pages are automatically rendered, each page being located by a corresponding network addresses in the search result. However, the patent does not create a structured document which could be rendered as a slide show presentation by a multimedia rendering software. The patent also does not teach providing an option to a user to edit and annotate the sequence of pages. The patent also does not teach providing an option to a user to save and publish the sequence of pages or to share the sequence of pages with other users.
[0014] U.S. Pat. No. 7,010,751 discloses a method for the electronic annotation, retrieval, and use of electronic images. The invention provides software for electronically annotating electronic images, such as drawings, photographs, video, etc., through the drag-and-drop of annotations from a pre-defined, but extendable, list. The annotations are placed at a user-selected X, Y location on the image, and stored in a searchable database. Thus, they can be searched in order to retrieve, organize, group, or display desired electronic images or collections of such images. The annotations may be text, images, sounds, etc. The invention provides a flexible, easy to learn, rapid, low error rate and satisfying interface for accomplishing such tasks. However, this patent does not teach the combination of searching for images on the internet, authoring a slideshow presentation of images in real-time, and publishing the slideshow presentation to a web URL or to a database.
SUMMARY OF THE INVENTION
[0015] The disclosure of the invention describes a method of dynamically creating real-time presentations responsive to search expressions. The method comprises retrieving from one or more search engines information responsive to a search expression, parsing the retrieved information to create dynamically, in real-time, a structured document including mark-up tags, and rendering, in real-time, the structured document as a slide show presentation of images by a multimedia presentation module residing in a client device. The structured document may be any document using mark-up tags, for example, HTML, XML, SGML, etc. The information retrieved from the one or more search engines may include one or more of image URLs, thumbnail URLs, source page URLs, web domain URLs, textual information, tags, metadata, and abstracts.
[0016] In an embodiment of the invention, the structured document may be editable, annotatable, storable, and publishable by a user viewing the slide show presentation on the client device. The editing capability may include, but not be limited to, the ability to select images, to add images, to remove images, to resize images, to crop images, to add layered mark-up to images, to combine one or more of the images into a single image, to change the sequence of images, to edit the transitions between images, to add audio clips to the presentation, and to blend in the presentation the images retrieved using the one or more search engines with other images or audio clips retrieved from any other source.
[0017] In another embodiment of the invention, the editing options may be manually or dynamically selected from a template-based edit decision list (EDL). In another embodiment, the editing options for the presentation may be dynamically selected based on any number of data-input/variables to another stored EDL.
[0018] In another embodiment of the invention, the presentation can dynamically translate textual information based on language setting of a client device/web browser.
[0019] In an embodiment of the invention, the annotation capability may include, but not be limited to, the ability to annotate the images with image captions or user comments. The storing capability may include the ability to store the structured document in a database. The publishing capability may include the ability to publish the structured document to a web URL so that the web URL can be shared by the user with other users and the slideshow presentation is viewable, editable, and annotatable by the other users.
[0020] In another embodiment of the invention, the information retrieved from the one or more search engines may be restricted to one or more specified web domains. The information may include information on multiple images for an object of interest. Pertinent textual information about the object of interest may also be retrieved along with the image information so that the images and the pertinent textual information are displayed together for convenient review by the user.
[0021] In another embodiment of the invention, a rollover of a mouse by a user on a search expression included in a web page triggers transmission of the search expression to the one or more search engines. In yet another embodiment, each displayed image in the slideshow presentation may have an embedded hyperlink to the source page of the image, for a user to view related information on the source page.
[0022] In another embodiment of the invention, the method of dynamically creating real-time presentations responsive to search expressions may comprise transmitting a search expression from a client device having a web browser to a web server, transmitting, in real-time, the search expression from the web server to one or more search engines, and retrieving from the one or more search engines information responsive to a search expression. The retrieved information may include one or more of image URLs, thumbnail URLs, source page URLs, web domain URLs, textual information, tags, metadata, and abstracts. The retrieved information may be parsed to create dynamically, in real-time, a structured document having mark-up tags. The structured document may be transmitted, in real-time, from the web server to the client device, and rendered, in real-time, as a slide show presentation of images by a client side multimedia presentation module.
[0023] Another embodiment of the invention discloses a system for dynamically creating customized presentations responsive to search expressions. The system may comprise a web server and a client device. The web server may include a module for creating a structured document from information responsive to a search expression retrieved from one or more search engines, a module for storing the structured document in a database on the web server, and a module for publishing the structured document to a web URL. The client device may be connectable to the web server by an internet connection, and may include an editing module for editing the structured document, an annotation module for annotating the structured document, and a multimedia presentation module for rendering the structured document as a slideshow presentation in real-time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 shows a block diagram of an embodiment of the invention.
[0025] FIG. 2 shows a flow diagram illustrating the process flow of an embodiment of the invention.
[0026] FIG. 3 shows a block diagram of another embodiment of the present invention.
[0027] FIG. 4 shows a flow diagram illustrating the process flow of another embodiment of the present invention.
[0028] FIG. 5 shows an embodiment of a user-interface on a client device, disclosing an embodiment of the invention.
[0029] FIG. 6 shows an embodiment of a user-interface on a client device, disclosing another embodiment of the present invention.
[0030] FIG. 7 shows an embodiment of a user-interface on a client device, disclosing yet another embodiment of the invention.
[0031] FIG. 8 shows an embodiment of a user-interface on a client device, disclosing an embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0032] An object of the invention is to facilitate fast and parallel review of relevant information instead of the conventional serial search from a search results page. Another object of the invention is to create automatically a flip-book style slide show presentation that allows for interesting, user-friendly, and passive review of selected images and textual information and dramatically reduces the number of user actions (clicks) required as compared with a conventional serial search. This kind of presentation may be particularly effective on internet connected small form factor mobile devices (for example, mobile phones, PDAs, etc.)
[0033] Another object of the invention is to enable a user to conveniently organize visual and textual information by automatically authoring a structured document (for example, an XML based document) so that information contained in the structured document could be rendered in different client devices (for example, a personal computer, a mobile device, a television, etc.) as a slideshow presentation. This can enable the same information to be automatically adapted for display in different client devices viewing data from across a vast number of sources.
[0034] Another object of the invention is to allow a user to edit and annotate the slideshow presentation of visual, textual, and audio information relating to a subject of interest obtained from the internet, from specific web domains, or from a user's collection and/or database. Adding relevant text over or around the image (user can determine what high-value info they want to add)—creates a compelling and informative snapshot, thus eliminating the need for excessive serial “blind” investigation of links in a convention search results page.
[0035] Another object of the invention is to allow a user to share the presentations created by him with others by saving and publishing the slideshow presentation (for example, to a web URL or to a database) and by sending the URL of the presentation to his contacts by email.
[0036] Another object of the invention is to facilitate a highly-efficient parallel search paradigm that is not bound by spatial 2D (or even 3D) constraints of the traditional page/list view and incorporates the additional dimension of time in the slide show presentation.
[0037] In the following description of various embodiments including the preferred embodiment, reference is made to the accompanying drawings, which show by way of illustration the embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural and functional modifications may be made without departing from the spirit or scope of the invention. Those skilled in the art will readily appreciate that the detailed description given herein with respect to these drawings is for explanatory purposes as the invention extends beyond these limited embodiments.
[0038] FIG. 1 shows a block diagram of an embodiment of the invention as disclosed herein. The embodiment discloses a client machine 150 connectable to a web server 100 and one or more search engines 120 . The client machine 150 includes a module 130 for creating structured documents having markup tags, an editing & annotating module 160 , and a client side presentation module 170 . The web server 100 includes a module to publish structured documents to a unique web URL 180 , and a module to publish structured documents to a database 140 .
[0039] A user enters a search expression 110 in the client machine 150 . A search expression 110 can be a particular word, phrase, or collection of words pertaining to which an image search is to be conducted. The client machine 150 can be a PC, a mobile device, a television, etc. The client machine 150 passes the search expression 110 to the search engines 120 . The search engines 120 can be commercial databases of indexed web pages on the World Wide Web (for example, Google™, Altavista™, MSN™, Wikipedia™, Flickr™, and other commercial databases (such as, travelocity.com, car.com) etc.). The search engines 120 return the information corresponding to the search expression such as, but not limited to image URLs, thumbnail URLs, source page URLs, web domain URLs, textual information, tags, metadata, abstracts and alt text, etc.
[0040] The information retrieved from the search engines 120 can be sent for conversion to the module 130 for creating structured documents having mark-up tags. The module 130 for creating structured documents converts the retrieved information into a structured document. The structured document can be a document having multiple mark-up tags. Examples of the structured document can be extensible mark up language (XML) based documents, hypertext markup language (HTML) based documents, standard generalized mark-up language (SGML) based documents, etc. The user can view the thumbnails of the images retrieved from the internet. Further, based on choice or requirement the user can edit/annotate the structured document or he can publish the structured document with or without editing. The user can publish the structured document to a unique web URL using the module for publishing structured document to a unique web URL 180 or it can be published to a database 140 (both residing on the web server 100 ).
[0041] If the user opts for editing and annotating the structured document, the system can send the structured document to the editing and annotating module 160 residing on the client machine 150 . The editing & annotating module 160 facilitates the user to do a variety of editing tasks, for example, but not limited to, annotate, insert comments, add images, remove images, resize images, crop images, add layered mark-up to images, combine one or more images into a single image file, change the sequence of images, edit the transitions between images, add audio clips to the presentations, and blend in the presentation the images retrieved using the one or more search engines with other images or audio clips retrieved from any other source, etc.
[0042] The edited/annotated structured documents can be rendered by the client side presentation module 170 to display a slide show of images. In another embodiment the edited/annotated structured documents can also be rendered by the client side presentation module 170 to display a formatted printable page and/or a PDF document depending upon the user's requirement. The client side presentation module 170 can be a multimedia rendering application, and/or a document rendering application. Examples of the multimedia rendering application can be a Flash player, etc. and the document rendering application can be a Microsoft office tool, Adobe Acrobat Reader, etc. If the user wants, he/she can save the edited/annotated structured document to the database 140 residing on the web server 100 for future use.
[0043] FIG. 2 shows a flow diagram illustrating the process flow of an embodiment of a method of dynamically creating customized presentations corresponding to a search expression.
[0044] In step 200 , a search expression can be sent to one or more search engines using a client machine for real time search. A search expression can be a particular word, phrase, or collection of words.
[0045] In step 210 , the client machine retrieves the information corresponding to the search expression from one or more search engines. The information can include, but not limited to, image URLs, thumbnail URLs, source page URLs, web domain URLs, textual information, tags, metadata, abstracts and alt text, etc.
[0046] In step 220 , the retrieved information can be sent to a module for creating structured documents, wherein the information can be parsed to create a structured document having mark-up tags.
[0047] In step 230 , the structured document can be rendered as a slide show presentation, a formatted printable page, and/or a PDF document in the client device using a client side presentation module or the structured document can be sent to the editing and annotating module.
[0048] In step 240 , the structured document can be sent for editing and annotating as per user's choice. The user can do a variety of editing and annotating tasks.
[0049] In step 250 , the structured document after editing/annotating can be stored to the database or can be published to a unique web URL that can be accessed using any web browser, and/or it can be rendered as a slide show to the user.
[0050] FIG. 3 shows a block diagram of an embodiment of the invention as disclosed herein. The embodiment discloses a system of dynamically creating customized presentations corresponding to a search expression. The embodiment includes a web server 300 connectable with a client machine 350 and one or more search engines 320 . The web server 300 includes a module 330 for creating structured documents having mark-up tags, a module 380 to publish structured documents to a unique web URL and a module 340 to publish structured documents to a database for storing purpose. The client machine 350 includes an editing & annotating module 360 and a client side presentation module 370 .
[0051] A user enters a search expression 310 using the client machine 350 . The client machine 350 can be a PC, a mobile device, a television, etc. The client machine 350 using a web browser sends the search expression 310 to the web server 300 . The web server 300 can be any computer, which is responsible for accepting HTTP requests from the web browser on the client machine 350 and responding to the HTTP requests and serving back to the web browser the required information.
[0052] The web server 300 passes the search expression 310 to the one or more search engines 320 . The one or more search engines 320 return the information corresponding to the search expression 310 . The information can include, but not be limited to, image URLs, thumbnail URLs, source page URLs, web domain URLs, textual information, tags, metadata, abstracts and alt text, etc.
[0053] The information retrieved from the one or more search engines 320 can be sent to the module 330 for creating a structured document having mark-up tags. The structured document can be a document having multiple mark-up tags. Examples of structured documents can be extensible mark up language (XML) based documents, hypertext markup language (HTML) based documents, standard generalized mark-up language (SGML) based documents, and the like.
[0054] The structured document may be edited and annotated by a user using the editing & annotating module 360 residing on the client machine 350 . The user may publish the structured document to a unique web URL 380 , or to a database 340 residing on the web server 300 depending upon his/her choice. The editing & annotating module 360 enables the user to do a variety of editing and annotating tasks, for example, but not limited to, annotate, insert comments, add images, remove images, resize images, crop images, add layered mark-up to images, combine one or more images into a single image file, change the sequence of images, edit the transitions between images, add audio clips to the presentations, and to blend in the presentation the images retrieved using the one or more search engines with other images or audio clips retrieved from any other source, etc. The structured document can be rendered by the client side presentation module 370 to display a slide show of images before or after sending the structured document to the editing and annotating module. The structured document can also be displayed as a formatted printable page and/or a PDF document depending upon the user's requirement. The client side presentation module 170 can be a multimedia rendering application, and/or a document rendering application. Example of the multimedia rendering application can be a Flash player, etc and the document rendering application can be a Microsoft office tool, Adobe Acrobat Reader, etc. The structured document can be published to a unique web URL or it can be saved to the database 340 for future use.
[0055] FIG. 4 shows a flow diagram illustrating the process flow of a method of dynamically creating customized presentations corresponding to a search expression.
[0056] In step 400 , a search expression can be sent to a web server using a client machine. A search expression can be a particular word, phrase, or collection of words.
[0057] In step 410 , the search expression can be transmitted from the web server to one or more search engines for real time search.
[0058] In step 420 , the web server retrieves the information corresponding to the search expression from the one or more search engines.
[0059] In step 430 , the retrieved information can be sent to a module for creating structured documents, wherein the retrieved information can be parsed to create a structured document having mark-up tags.
[0060] In step 440 , the structured document can be rendered as a slide show presentation, a formatted printable document and/or a PDF document in the client device using the client side presentation module and/or it may be sent to an editing and annotating module.
[0061] In step 450 , the structured document can be sent for editing and annotating as per user's choice.
[0062] In step 460 , the structured document after editing/annotating can be stored to the database or can be published to a unique web URL that can be accessed using any web browser, and/or it can be rendered as a slide show, a formatted printable document and/or a PDF document to the user.
[0063] FIG. 5 shows an embodiment of a user-interface on a client device, disclosing a user-interface for dynamically authoring customized presentations corresponding to a search expression. The embodiment includes a search box 500 in which a user can input a search expression 510 . The search expression 510 can be sent to one or more search engines for real time search. The one or more search engines provide desired information such as, but not limited to, image URLs, thumbnail URLs, source page URLs, web domain URLs, textual information, tags, metadata, abstracts, and alt text, etc. corresponding to the search expression 510 . A web browser residing on the client device can display thumbnails of images in the form of a thumbnail gallery 520 to the user. The user can select a set of thumbnails 530 from the thumbnail gallery 520 using any one of several methods such as drag-and-drop method, click to select method, etc.
[0064] The information retrieved from the one or more search engines for the selected set of thumbnails can be sent to a module for creating a structured document (not shown) having mark-up tags. The module for creating structured documents converts the information corresponding to the selected set of thumbnails into a structured document. The structured document can be rendered by the client side presentation module (not shown) to display a slide show presentation 540 on the user-interface. The method enables the user to view the complete slideshow of selected and ordered images without having to serially drill the link for each image.
[0065] FIG. 6 shows an embodiment of a user-interface showing a few options for editing/annotating a slide show presentation 605 of selected images corresponding to a structured document. The embodiment discloses a user interface with several editing/annotating options. The slide show presentation 605 can be displayed to the user. The user can be provided with several editing options such as, but not limited to, “save” 620 , “add text” 630 , “delete an image” 635 , “E-mail” 640 , “insert an image” 650 , etc. For example, the user can use the editing option “delete an image” 635 to delete an image from the slide show presentation. The editing & annotating module before implementing any instruction seeks confirmation 610 from the user's end. The user can use the editing option “Add Text” 630 to annotate each image of the slide show presentation. Similarly, the user can use the editing option “save” 620 and publish the structured document (not shown) to a database (not shown) residing on a web server (not shown). After completion of editing and annotating, the user can use the option “e-mail” 640 to send the saved structured document (not shown) to his contacts. It is to be understood that all the editing options basically modify the structured document. The slide show presentation displays the changes to the user when the modified structured document is rendered by a client side presentation module (not shown).
[0066] FIG. 7 shows an embodiment of a user-interface for some other editing options (not a complete list of editing options) for a slide show presentation corresponding to a structured document. The embodiment discloses some editing options such as “add caption text” 710 , “transition mode” 720 , and “time duration” 730 , etc. A user can use the editing option “add caption text” 710 to add details such as image name, user comments, etc. to images displayed in the slideshow presentation. The user can use the editing option “transition mode” 720 to change the transition style between consecutive images of the slide show presentation. Examples of “transition mode” can be “drop”, “squeeze down”, “squeeze up”, “move left”, “move right”, etc. Similarly, the user can use the editing option “time duration” 730 to variate the time interval between the transitions of images. All the changes can be saved in a structured document using a “Save Changes” 740 option. It is to be understood that all the editing options basically modify the structured document. The slide show presentation displays the changes to the user when the modified structured document is rendered by a client side presentation module (not shown).
[0067] In a conventional search system, search results entirely depend upon the formation of search expressions. Variation of single word in a search expression may lead to entire new set of search results. Thus, to facilitate a user, the embodiment discloses an alternative way of forming a search query, which can be termed as a rollover search expression. In the rollover search expression as the user's mouse will roll over a suggested search phrase, an automatic search query is generated, which will yield search results from search engines.
[0068] FIG. 8 shows an embodiment of a web page in which some of the search expressions are part of the text of the web page, and the web page is programmed such that when a user's mouse will roll over say the search expression 810 (“Ford F 150” in this example), an automatic search query is generated corresponding to the search expression 810 , and information related to the search expression 810 “Ford F 150” can be retrieved from one or more search engines and/or specific web domains. A set of thumbnails 820 corresponding to the search expression is displayed to the user as a thumbnails galley. The user selects some images from the thumbnails galley. A structured document corresponding to the selected images is created which can be rendered as a slide show presentation 830 by a client side presentation module and displayed to the user. The user can use an editing option “add comments” 840 to add comments to each image.
[0069] Having fully described the preferred embodiment, other equivalent or alternative methods of retrieving information, creating structured documents, editing and annotating the structured documents, rendering the structured documents as slide show presentations by a rendering software, and publishing the documents according to the present invention will be apparent to those skilled in the art. The invention has been described above by way of illustration, and the specific embodiment disclosed is not intended to limit the invention to the particular forms disclosed. For example, the embodiments described in the foregoing were directed to providing you clear ideas about the preferred modes, including the best mode, of making and using the present invention; however, in alternate embodiments, those skilled in the art may implement the invention using various other means without deviating from the central idea of the invention. The invention therefore covers all modifications, equivalents, and alternatives falling within the spirit and scope of the following claims. | The disclosure describes a method of dynamically creating real-time presentations responsive to search expressions. The method comprises retrieving information from search engines, parsing the retrieved information to create dynamically a structured document including mark-up tags, and rendering the structured document as a slide show presentation of images by a multimedia presentation module. The structured document may be editable, annotatable, storable, and publishable by a user viewing the slide show presentation on the client device. The information retrieved from the one or more search engines may be restricted to one or more specified web domains. Pertinent textual information about the object of interest may also be retrieved along with the image information for convenient review by the user. Each displayed image in the slideshow presentation may have an embedded hyperlink to the source page of the image. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 61/225,331, filed on Jul. 14, 2009. The disclosure of the above application is incorporated herein by reference in its entirety.
FIELD
The present disclosure relates to a fuel system for a vehicle and more particularly to determining an error in a pressure sensor of a fuel system.
BACKGROUND
The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Internal combustion engines combust an air/fuel (A/F) mixture within cylinders to drive pistons and to provide drive torque. Air is delivered to the cylinders via a throttle and an intake manifold. A fuel injection system supplies fuel from a fuel tank to provide fuel to the cylinders based on a desired A/F mixture. To prevent release of fuel vapor, a vehicle may include an evaporative emissions system which includes a canister that absorbs fuel vapor from the fuel tank, a canister vent valve, and a purge valve. The canister vent valve allows air to flow into the canister. The purge valve supplies a combination of air and vaporized fuel from the canister to the intake system.
Closed-loop control systems adjust inputs of a system based on feedback from outputs of the system. By monitoring the amount of oxygen in the exhaust, closed-loop fuel control systems manage fuel delivery to an engine. Based on an output of oxygen sensors, an engine control module adjusts the fuel delivery to match an ideal A/F ratio (14.7 to 1). By monitoring engine speed variation at idle, closed-loop speed control systems manage engine intake airflows and spark advance.
Typically, the fuel tank stores liquid fuel such as gasoline, diesel, methanol, or other fuels. The liquid fuel may evaporate into fuel vapor which increases pressure within the fuel tank. Evaporation of fuel is caused by energy transferred to the fuel tank via radiation, convection, and/or conduction. An evaporative emissions control (EVAP) system is designed to store and dispose of fuel vapor to prevent release. More specifically, the EVAP system returns the fuel vapor from the fuel tank to an engine for combustion therein. The EVAP system is a sealed system to meet zero emission requirements. More specifically, the EVAP system may be implemented in a plug-in hybrid vehicle with minimum engine operation that stores fuel vapor prior to being purged to the engine.
The EVAP system includes an evaporative emissions canister (EEC), a purge valve, and a diurnal control valve. When the fuel vapor increases within the fuel tank, the fuel vapor flows into the EEC. The purge valve controls the flow of the fuel vapor from the EEC to the intake manifold. The purge valve may be modulated between open and closed positions to adjust the flow of fuel vapor to the intake manifold.
Determining whether a fuel leak occurs is important in a closed system. However, adding additional pressure sensors increases the cost of the system.
SUMMARY
The present disclosure provides a method and system for determining the accuracy of a fuel tank pressure sensor using components found in a vehicle fuel system.
In one aspect of the disclosure, a method includes opening a diurnal control valve, switching on an ELCM diverter valve, generating a fuel tank pressure signal, generating an ELCM pressure signal, correlating the ELCM pressure signal and the fuel tank pressure signal and generating a fault signal in response to correlating.
In another aspect of the disclosure, a control module includes a diurnal control valve module that opens a diurnal control valve and an ELCM diverter valve control module that switches on an ELCM diverter valve. The control module includes a correlation module performs a correlation of a ELCM pressure signal and a fuel tank pressure signal and that generates a fault signal in response to the correlation when the DCV valve is open and the ELCM diverter valve is on.
Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a functional block diagram of an engine system of a vehicle according to the present disclosure;
FIG. 2 is a functional block diagram of an engine control module according to the principles of the present disclosure; and
FIG. 3 is a flowchart depicting exemplary steps performed by the engine control module according to the principles of the present disclosure.
DETAILED DESCRIPTION
The following description is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C), using a non-exclusive logical or. It should be understood that steps within a method may be executed in different order without altering the principles of the present disclosure.
As used herein, the term module refers to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.
Referring now to FIG. 1 , a functional block diagram of an exemplary engine system 100 of a vehicle is shown. The engine system may be for a conventional Spark-ignited (SI) engine, a Homogeneous Charge Compression Ignited (HCCI) engine or an extended range electric vehicle engine which is used as a generator for generating electric power for charging a battery pack. The engine system 100 includes a fuel system 102 , an EVAP system 104 , and an engine control module 106 . The fuel system 102 includes a fuel tank 108 , a fuel inlet 110 , a fuel cap 112 , and a modular reservoir assembly (MRA) 114 . The MRA 114 is disposed within the fuel tank 108 and pumps liquid fuel to a fuel injection system (not shown) of the engine system 100 to be combusted. A fuel tank pressure sensor 164 generates a fuel tank pressure signal corresponding to the pressure within the fuel tank.
The EVAP system 104 includes a fuel vapor line 116 , a canister 118 , a fuel vapor line 120 , a purge valve (PV) 122 , a fuel vapor line 124 , an air line 126 , a diurnal control valve (DCV) 128 , and an air line 130 .
The fuel tank 108 contains liquid fuel and fuel vapor. The fuel inlet 110 extends from the fuel tank 108 to enable fuel filling. The fuel cap 112 closes the fuel inlet 110 .
Fuel vapor flows through the fuel vapor line 116 into the canister 118 , which stores the fuel vapor. The fuel vapor line 120 connects the canister 118 to the PV 122 , which is initially closed in position. The engine control module 106 controls the PV 122 to selectively enable fuel vapor to flow through the fuel vapor line 124 into the intake system (not shown) of the engine system 100 to be combusted. Air flows through the air line 126 to the DCV 128 , which is initially closed in position. The engine control module 106 controls the DCV 128 to selectively enable air to flow through the air line 130 into the canister 118 .
The air line 126 may include an evaporative leak check module (ELCM) 140 . An ELCM filter 141 may filter the air flow to the ELCM 140 . The evaporative leak check module 140 may include an ELCM diverter valve 142 , a vacuum pump 144 and an ELCM pressure sensor 146 . A reference orifice 148 may also be included within the evaporative leak check module 140 . The diverter valve 142 includes a first path 150 and a second path 152 therethrough. In the first position 150 , as illustrated, air is directed through the diverter valve directly from the input to the DCV 128 . In the second position 152 , the diverter valve 142 is controlled upward so that the vacuum pump 144 is in use and air travels through the vacuum pump 144 to the diurnal control 128 . In either case, the pressure sensor 146 generates a pressure signal corresponding to the pressure within the ELCM 140 .
The engine control module 106 regulates operation of the engine system 100 based on various system operating parameters. The engine control module 106 controls and is in communication with the MRA 114 , the fuel tank pressure sensor 164 , the PV 122 , the DCV 128 and the ELCM 140 .
Referring now to FIG. 2 , a functional block diagram of the engine control module 106 is shown. The engine control module 106 includes a correlation module 200 , a fuel tank pressure module 202 , a PV control module 204 , an evaporative leak check module (ELCM) pressure module 206 , a DCV control module 208 and an ELCM control module 210 .
The fuel tank pressure module 202 receives the fuel tank pressure signal and determines a fuel tank pressure based on the fuel tank pressure signal.
The ELCM pressure module 206 generates a pressure corresponding to the evaporative leak check module pressure sensor 146 of FIG. 1 . The ELCM pressure signal and the fuel tank pressure are provided to the correlation module 200 . The correlation module 200 provides control signals to the purge valve control module 204 that controls purge valve 122 . The correlation module 200 also provides control signals to the diurnal control valve control module 208 . The purge valve control module 204 controls the purge valve 122 as will be described below during a correlation of the pressure sensors. Likewise, the DCV control module 208 controls the DCV 128 during correlation of the pressure sensors.
The ELCM control module 210 includes an ELCM vacuum pump control module 220 and an ELCM diverter valve control module 222 . The ELCM vacuum pump control module 222 controls the ELCM vacuum pump 144 and the ELCM diverter valve control module controls the ELCM diverter valve 142 .
The correlation module 200 controls the operation of the purge valve 122 , the diurnal control valve 128 , the ELCM diverter valve 142 and the vacuum pump 144 in a predetermined manner to provide a sensor correlation between the fuel tank pressure and the pressure measured at the ELCM pressure sensor 146 of FIG. 1 . The correlation module 200 may, for example, determine a plurality of differences between the fuel tank pressure and the ELCM pressure and generates an average difference signal. The average difference signal may be compared to a correlation value or threshold. When the difference between the fuel tank and ELCM pressure is outside of a correlation range, an error indicator 230 may be activated. The error indicator 230 may provide an error signal through an on-board diagnostic system, or the like. The error indicator 230 may also be used to provide an audible or visual indicator as to an error to the vehicle operator.
Referring now to FIG. 3 , a method for operating the present disclosure is set forth. In step 310 , the initial positions of the various valves are initiated. It should be noted that the present disclosure may be performed both in engine-running and engine-off states. In step 310 , the initial positions correspond to the purge valve being closed, the diurnal control valve being closed, the diverter valve being off and the ELCM vacuum pump being off. At this point, no sensor correlation is taking place.
In step 312 , the ELCM diverter valve is turned on which places the ELCM diverter valve in the upper-most position 152 illustrated in FIG. 1 . In step 314 , the DCV valve is opened. In step 316 , the system waits for a stabilization time. The stabilizing time allows the system to equalize prior to pressure measurement. In step 318 , the pressure sensor signals are correlated.
The correlation of the pressure sensors in step 318 includes many steps including step 320 that measures the fuel tank pressure from the fuel tank pressure sensor. In step 322 , the pressure at the ELCM pressure sensor is determined. In step 324 , a difference of the measured fuel tank pressure and the measured ELCM pressure is determined. The difference may be obtained several times over a range of times and an average difference may be determined. When the average difference is greater than a calibration threshold (CAL) in step 324 , step 326 generates an error signal. In step 324 , when the difference is not greater than a calibration, a correlation signal is generated in step 328 . After step 328 , the DCV valve is closed in step 330 and the ELCM diverter valve is closed in step 332 .
As will be evident to those skilled in the art, an additional pressure sensor for verifying the proper operation of the fuel tank pressure sensor is not provided. By providing the same pressure to the fuel tank pressure sensor and the ELCM pressure sensor, both of the sensors are exposed to the same pressure/vacuum environment and therefore a correlation of the two sensors may be performed.
Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification, and the following claims. | A control module and method for operating the same includes a diurnal control valve module that opens a diurnal control valve (DCV) and an evaporative leak check module (ELCM) diverter valve control module that switches on an ELCM diverter valve. The control module includes a correlation module performs a correlation of a ELCM pressure signal and a fuel tank pressure signal and that generates a fault signal in response to the correlation when the DCV valve is open and the ELCM diverter valve is on. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relate to a method used to fabricate semiconductor devices, and more specifically to a method used to fabricate a dynamic random access memory, (DRAM), device, using a storage node structure, with a roughened top surface.
2. Description of Prior Art
The semiconductor industry is continually striving to improve the performance of semiconductor devices, while still maintaining, or even decreasing the manufacturing cost of these same semiconductor devices. The advent of micro-miniaturization, or the ability to fabricate semiconductor devices, with sub-micron features, has allowed the industry's performance and cost objectives to be successfully addressed. The use of sub-micron features result in decreases in performance degrading capacitances and resistances, thus allowing improved device performance to be realized. In addition the use of micro-miniaturization allows smaller chips, still containing circuit densities comparable to circuit densities obtained with larger semiconductor chips, to be fabricated. This in turn results in an increase in the amount of semiconductor chips obtained from a specific size starting substrate, thus resulting in a reduction of manufacturing cost of a specific chip.
Dynamic random access memory, (DRAM), devices, are being fabricated using a stacked capacitor, (STC), structure, overlying a transfer gate transistor. The shrinking of device features has resulted in a decrease in STC dimensions. Therefore the capacitance of the STC structure, influenced by the dimensions of the storage node electrode, has to be increased via other means. The use of thinner capacitor dielectric layers, or higher dielectric constant materials, used to increase STC capacitance, is limited by process complexity or yield concerns. Therefore the DRAM community has focused on capacitance increases via the creation of storage node electrodes, exhibiting a roughened topology, or a top surface comprised of concave and convex features. The use of a storage node electrode, with a roughened top surface topology, results in an increase in surface area, when compared to counterparts fabricated with a smooth top surface topology, thus resulting in an increase in STC capacitance.
One method of creating a storage node electrode, with a roughened surface, is the formation of an overlying hemispherical grained silicon, (HSG), layer. The ability to create the HSG layer, comprised of silicon bumps, results in surface area increases. Prior art, such as Weimer, et al, in U.S. Pat. No. 5,634,974, describes a method for formation of an HSG silicon layer, to be used as the top layer for a storage node structure. However the method chosen by Weimer, et al, is complex in regards to initially forming silicon seeds, followed by critical annealing procedures. This invention will describe an alternative to HSG silicon, for providing increased surface area for a storage node electrode, resulting in the improved STC capacitance needed for high density DRAM devices. This invention will describe the formation of, and the removal of, a metal silicide layer, from the surface of a storage node electrode, resulting in a roughened, or creviced surface, of polysilicon storage node electrode, resulting in increased surface area, without using HSG silicon layers.
SUMMARY OF THE INVENTION
It is an object of this invention to fabricate a stacked capacitor, (STC) ,structure, of a DRAM device, in which the capacitance of the STC structure, is increased via use of a storage node electrode, exhibiting a roughened top surface.
It is another object of this invention to form a metal silicide layer, on the top surface of a polysilicon storage node electrode, via reaction of an overlying metal layer with regions of the underlying polysilicon storage node electrode.
It is still another object of this invention to remove the metal silicide layer from the underlying polysilicon storage node electrode, resulting in crevices in the surface of underlying polysilicon storage node electrode, in regions in which the metal silicide resided.
In accordance with the present invention a method is described for increasing the surface area of a polysilicon storage node electrode, by forming, and removing, a metal silicide layer, from the top surface of the polysilicon storage node electrode. An insulator layer is deposited on an underlying transfer gate transistor, followed by the creation of a storage node opening, in the insulator layer, exposing a source and drain region of the transfer gate transistor. A polysilicon layer is deposited, and patterned to create a polysilicon storage node electrode, in the storage node opening. A metal layer is next deposited, and subjected to a first anneal procedure, converting the metal, on the polysilicon storage node electrode, to a first metal silicide layer, while leaving the metal layer, on the top surface of the insulator layer, unreacted. After removal of the unreacted metal layer, a second anneal procedure is used to form a second metal silicide layer, consuming regions of the underlying polysilicon storage node electrode. The second metal silicide layer is next removed, resulting in crevices in the underlying polysilicon storage node electrode, in regions in which polysilicon was consumed during the second anneal procedure. The formation of a capacitor dielectric layer, on the creviced, or roughened surface of the polysilicon storage node electrode, is next performed, followed by the creation of a polysilicon upper capacitor plate, resulting in a stacked capacitor structure, featuring a polysilicon storage node electrode with increased surface area as a result of the roughened, top surface.
BRIEF DESCRIPTION OF THE DRAWINGS
The object and other advantages of this invention are best described in the preferred embodiment with reference to the attached drawings that include:
FIGS. 1-8, which schematically, in cross-sectional style, show key stages of fabrication, used to create a storage node electrode with a roughened top surface.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The method for forming a DRAM device, with a stacked capacitor structure, featuring a polysilicon storage node electrode with a roughened top surface, created to increase surface area, and capacitance, of the stacked capacitor structure, will now be described in detail. The DRAM device, in this invention, will be described as an N channel device, however the process for forming a roughened top surface, polysilicon storage node electrode, can also be applied to DRAM devices, comprised of P channel, transfer gate transistor.
Referring to FIG. 1, a P type, semiconductor substrate 1, with a <100>, single crystalline orientation, is used. Field oxide, (FOX), regions 2, are used for purposes of isolation. Briefly the FOX regions 2, are formed via thermal oxidation, in an oxygen-steam ambient, at a temperature between about 850° to 1050° C., to a thickness between about 3000 to 5000 Angstroms. A patterned oxidation resistant mask of silicon nitride-silicon oxide is used to prevent FOX regions 2, from growing on areas of semiconductor substrate 1, to be used for subsequent device regions. After the growth of the FOX regions 2, the oxidation resistant mask is removed via use of a hot phosphoric acid solution for the overlying, silicon nitride layer, and a buffered hydrofluoric acid solution for the underlying silicon oxide layer. After a series of wet cleans, a gate insulator layer 3, of silicon dioxide is thermally grown in an oxygen-steam ambient, at a temperature between about 850° to 1050° C., to a thickness between about 50 to 200 Angstroms. A polysilicon layer 4, is next deposited using low pressure chemical vapor deposition, (LPCVD), procedures, at a temperature between about 500° to 700° C., to a thickness between about 1000 to 3000 Angstroms. The polysilicon can either be grown intrinsically and doped via ion implantation of arsenic or phosphorous, or polysilicon layer 4, can be grown using in situ doping procedures, via the incorporation of either arsine, or phosphine, to the silane ambient. A first insulator layer 5, comprised of silicon oxide, or silicon nitride, is next deposited using LPCVD, or plasma enhanced chemical vapor deposition, (PECVD), procedures, to a thickness between about 2000 to 3000 Angstroms. Conventional photolithographic and reactive ion etching, (RIE), procedures, using CHF 3 as an etchant for first insulator layer 5, and using Cl 2 as an etchant for polysilicon layer 4, are used to create polysilicon gate structure 6, comprised of first insulator layer 5, and polysilicon layer 4, shown schematically in FIG. 1. Photoresist removal is accomplished via plasma oxygen ashing and careful wet cleans.
A lightly doped source and drain region 7, is next formed via ion implantation of phosphorous, at an energy between about 20 to 50 KeV, at a dose between about 1E13 to 1E14 atoms/cm 2 . A second insulator layer, comprised of silicon oxide, or silicon nitride, is deposited using either LPCVD or PECVD procedures, at a temperature between about 400° to 700° C., to a thickness between about 800 to 2000 Angstroms, followed by an anisotropic RIE procedure, using SF 6 as an etchant, creating insulator spacers, 8, on the sides of polysilicon gate structures 6. A heavily doped source and drain region 9, is then formed via ion implantation of arsenic, at an energy between about 30 to 100 KeV, at a dose between about 1E14 to 5E16 atoms/cm 2 . This is schematically shown in FIG. 1.
A third insulator layer 10, of silicon oxide, is next deposited using LPCVD or PECVD procedures, at a temperature between about 400° to 800° C., to a thickness between about 3000 to 7000 Angstroms, followed by a planarization procedure, using a chemical mechanical polishing, (CMP), procedure, used to create a smooth top surface for insulator layer 10. Conventional photolithographic and anisotropic RIE procedures, using CHF 3 as an etchant for insulator layer 10, are used to create storage node opening 11, in insulator layer 10, exposing the top surface of heavily doped source and drain regions 9. This is schematically shown in FIG. 2. Removal of photoresist shape, used as a mask for the creation of storage node opening 11, is accomplished via use of plasma oxygen ashing and careful wet cleans.
A polysilicon layer is next deposited using LPCVD procedures, to a thickness between about 2000 to 5000 Angstroms, and doped in situ, during deposition, via the addition of arsine, of phosphine, to a silane ambient. Photolithographic and anisotropic RIE procedures, using Cl 2 as an etchant, are used to form polysilicon storage node electrode 12a, in storage node opening 11, schematically shown in FIG. 3. After removal of the photoresist shape, used for polysilicon storage node electrode formation, via plasma oxygen ashing and careful wet cleans, a titanium layer 13a, is deposited using R. F. sputtering, to a thickness between about 200 to 400 Angstroms. This is schematically shown in FIG. 3.
A first rapid thermal anneal, (RTA), procedure is employed, to convert titanium layer 13a, overlying polysilicon storage node electrode 12a, to a first titanium silicide layer 13b, while leaving titanium layer 13a, overlying insulator layer 10, unreacted. This is schematically shown in FIG. 4. The first RTA procedure is performed at a temperature between about 700° to 740° C., for a time between about 20 to 40 sec., in a nitrogen ambient. The purpose of the first RTA procedure is to create a titanium silicide layer that will not be removed during the subsequent removal of unreacted titanium. The level of consumption of polysilicon from the top surface of polysilicon storage node electrode 12a, is still not great enough to create the desired roughened topology of the polysilicon storage node electrode. Removal of unreacted titanium layer 13a, is accomplished using NH 4 OH and H 2 O 2 . The result of titanium layer removal is schematically shown in FIG. 5.
A second RTA procedure is next performed at a temperature between about 860° to 900° C., for a time between about 20 to 40 sec., in a nitrogen ambient, converting first titanium silicide layer 13b, to second titanium silicide layer 13c. The formation of second titanium silicide layer 13c, results in consumption of underlying polysilicon, from the top surface of polysilicon storage node 12a, creating polysilicon storage node electrode 12b, which features a roughened top surface. This is shown schematically in FIG. 6.
Removal of second titanium silicide layer 13c, is next addressed via either a hydrofluoric acid dip, or via a dry etch procedure, using SF 6 and Cl 2 as an etchant, with both the wet and dry procedures selectively removing second titanium silicide layer 13c, from the top surface of polysilicon storage node 12b. The removal of second titanium silicide layer 13c, results in crevices in the top surface of polysilicon storage node electrode 12b, with dimensions of between about 0.03 to 0.05 uM in depth, and between about 0.04 to 0.06 uM in width. The crevices in the top surface of polysilicon storage node 12b, were formed via localized reaction of polysilicon and titanium, during the RTA anneals, followed by the removal of second titanium silicide layer 13c. This is schematically displayed in FIG. 7.
FIG. 8, schematically shows the completion of an STC structure 16, comprised of a storage node electrode 12b, featuring a roughened top surface topology. A capacitor dielectric layer 14, comprised of a composite dielectric layer of silicon oxynitride--silicon nitride--silicon oxide, (ONO), at an equivalent silicon oxide thickness of between about 50 to 80 Angstroms, is formed on the roughened surface of storage node electrode 12b. The ONO layer is created by initially creating a native, silicon oxide layer, between about 10 to 20 Angstroms in thickness, on the surface of polysilicon storage node electrode 12b. A thin layer of silicon nitride is next deposited, using LPCVD procedures, to a thickness between about 40 to 80 Angstroms. An oxidation procedure, performed in an oxygen--steam ambient, is next used to convert the surface of the silicon nitride layer, to a silicon oxynitride layer, thus creating the ONO layer. After creation of capacitor dielectric layer 14, another polysilicon layer is deposited, via LPCVD procedures, to a thickness between about 500 to 2000 Angstroms. The polysilicon layer can be grown using in situ doping techniques, or grown intrinsically and doped via ion implantation procedures, using arsenic or phosphorous. Conventional photolithographic and RIE procedure, using Cl 2 as an etchant are used to create upper electrode, or capacitor plate 15, shown schematically in FIG. 8. Photoresist removal is once again performed, using plasma oxygen ashing and careful wet cleans, resulting in STC structure 16, featuring increased capacitor surface area, and thus increased capacitance, resulting from the use of a storage node electrode, comprised of a roughened top surface, achieved via formation and removal of a metal silicide layer.
While this invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention. | A method for increasing the surface area of a polysilicon storage node electrode, used as a component for a DRAM stacked capacitor structure, has been developed. The method features forming a metal silicide layer, on the top surface of the polysilicon storage node electrode, locally consuming regions of underlying polysilicon during the metal silicide formation. Removal of the metal silicide layer, from the surface of the polysilicon storage node electrode, results in a roughened surface, comprised of crevices in the top surface of the polysilicon storage node electrode, in regions in which localized metal silicide formation had occurred. The crevices in the top surface of the polysilicon storage node electrode result in surface area increases, when compared to counterparts fabricated using smooth polysilicon surfaces. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a pulse generation circuit used in an electronic circuit of a communication device such as a television receiver.
2. Description of the Related Art
FIG. 3 is a block diagram showing a pulse delay circuit. In operation, a pulse P1 input to an input terminal IN is supplied to a time constant circuit formed of a resistor R 1 and a capacitor C 1 , via a buffer amplifier, so that a wave P2 which is delayed by time t 1 with respect to the pulse P1 can be derived from a point a. The wave P2 is input to the next stage comparator (COMP) 23, sliced at a voltage level V th , and output as an output wave P3 from an output terminal OUT.
The waveforms P1-P3 thus obtained are shown in FIG. 4.
In the above described case, in order to generate the pulse P3 which is delayed by the time t 1 with respect to the pulse P1, it is only necessary to determine the delay time t 1 by the resistor R 1 and the capacitor C 1 . However, in order to determine the pulse width of the pulse P3, it has been necessary to change the reference voltage V th to adjust the slice level of the wave P2 at the point a. The adjustment of the reference voltage V th must be effected each time the pulse delay time t 1 is changed, thus causing a troublesome problem.
SUMMARY OF THE INVENTION
An object of this invention is to provide a pulse circuit capable of automatically adjusting the pulse widths of input and output signals to have a fixed relation therebetween.
A pulse signal delay circuit of the invention comprises an input node for receiving a first pulse signal; an output node for outputting a second pulse signal; a delay circuit for delaying the first pulse signal from the first output node to provide a delayed signal; a first comparator for comparing the first pulse signal from the input node with the second pulse signal from the output node to output a first comparison result; and a second comparator for comparing the first comparison result from the first comparator with the delayed signal from the delay circuit to output a second comparison result.
With the above construction, a voltage (or current) which is proportional to the pulse width of the input pulse signal is compared with a voltage (or current) which is proportional to the pulse width of the output signal output from the circuit by means of the first comparator so as to generate a difference therebetween. When a voltage (or current) corresponding to the generated difference and a pulse delayed by the delay circuit are input to the second comparator, the pulse width of a pulse signal which has been delayed by the delay circuit is set to be equal to the pulse width of the input pulse signal and then the pulse is derived from the output terminal OUT. As a result, the pulse widths of the input and output pulse signals are automatically set equal to each other irrespective of the delay time set. Therefore, it becomes unnecessary to set the circuit parameters again.
Further, it is also possible to set the ratio of the input pulse width to the output pulse width to a constant value, for example, 1:2 or 1:10, by changing and adjusting the circuit parameters.
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 DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention and, together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.
FIG. 1 is a block diagram of a pulse circuit showing an embodiment of this invention;
FIG. 2 is a circuit diagram of a pulse circuit showing an embodiment of this invention;
FIG. 3 is a circuit diagram showing a pulse circuit to which this invention is not applied; and
FIG. 4 is a timing chart for illustrating the operation of a pulse delay circuit of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 2 is a circuit diagram showing one embodiment of this invention.
The construction shown in FIG. 2 is the same as that shown in the block diagram shown in FIG. 1.
In FIG. 2, 1 denotes an example of a buffer amplifier. The buffer amplifier is constituted by a first transistor QP1 which is of PNP type, an NPN transistor QNI, and resistors R2 and R3 and is used to effect the impedance conversion with respect to an input pulse signal.
2 denotes an example of a delay circuit which is constituted by a resistor R 1 and a capacitor C 1 and functions to determine the delay time based on the time constant of the resistor and capacitor.
Further, 3 denotes an example of a second comparator constituted by NPN transistors QN8 and QN9, PNP transistors QP8 and QP9, resistors R8, R9 and R10, and a fourth current source I 4 . A difference current generated in the first comparator 5 is input to b and a wave of a delayed pulse signal is input to "a". The delayed pulse signal is sliced by a voltage at b. As a result, the pulse widths of the input pulse signal and output pulse signal are set equal to each other and the pulse signal is output from the output terminal OUT.
4 denotes an example of a first amplifier. This circuit is constituted by NPN transistors QN2 and QN3, PNP transistors QP2 and QP3, a first current source I 1 , resistors R4 and R5, and a capacitor C 2 . In this circuit, a current which is proportional to the pulse width of an input pulse signal is charged by means of QP3 into C2 (thus the amplifier acts as an integrator) and is output as a voltage from "d".
Further, 5 denotes an example of the first comparator. The circuit is constituted by NPN transistors QN4 and QN5, PNP transistors QP4 and QP5, and a second current source I 2 . The first comparator 5 compares voltages output from the first and second amplifiers with each other and converts a voltage difference into a current which is output as voltage from the point "b". The first comparator compares the pulse width of an input pulse signal and the pulse width of an output pulse signal with each other and generates a difference represented in terms of voltage.
6 denotes an example of the second amplifier. The circuit is constituted by PNP transistors QP6 and QP7, NPN transistors QN6 and QN7, resistors R6 and R7, a capacitor C3, and a third current source I 3 . The second amplifier causes a current which is proportional to the pulse width of an output pulse to be charged into the capacitor C3 via the PNP transistor QP6 (thus the amplifier acts as an integrator) and output as a voltage from "e".
This invention is not limited to the above embodiment and various modifications can be made.
For example, the pulse widths of input and output pulse signals set in the circuit of this invention can be selectively set to be equal to each other or set in the ratio of an integral number if necessary.
A concrete method of changing the relation between the input and output may be realized by changing the amplification factors of the comparators COMP-1 and -2, the gains of the AMP-1 and -2 or the like.
More specifically, in the case of the COMP-1, the ratio of the areas of the transistors QN4,, QN5, QP4 and QP5 in the block 5 is changed. That is, the amplification factor of the comparator COMP-1 can be changed by changing the ratio of the area of the transistors QN4 and QP4 to the area of the transistors QN5 and QP5 which is set to 1:x (at this time, the ratio of the area of the transistor QN4 to that of the transistor QP4 and the ratio of the area of the transistor QN5 to that of the transistor QP5 are kept unchanged). As a result, the slice level is changed and the pulse width of P3 can be changed. Further, in the case of the comparator COPM-2, the resistances of R8 and R9 in the block 5 in the embodiment of FIG. 2 are set to proper values without changing the ratio thereof.
In the case of the gain of the AMP-1, the ratio of the areas of the transistors QP2 and QP3 in the block 4 is changed, and in the case of the gain of the AMP-2, the ratio of the areas of the transistors QP6 and QP7 in the block 4 is changed.
In the conventional pulse delay circuit, the pulse width of the delayed pulse signal is set each time delay time is selectively set, but the proportional relation between the pulse widths of the input and output pulse signals can be automatically obtained with respect to a selectively set delay time or a given input signal if the circuit parameters are initially set by using the circuit construction of this invention. In this way, the operation of adjusting the pulse width of a pulse signal or an external device for effecting the operation can be alleviated or omitted.
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 devices, shown and described. 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. | A pulse signal delay circuit comprises an input node for receiving a first pulse signal, an output node for outputting a second pulse signal, a delay circuit for delaying the first pulse signal to provide a delayed signal, a first comparator for comparing the first pulse signal with the second pulse signal to output a first comparison result, and a second comparator for comparing the first comparision result with the delayed signal to output a second comparison result. | 7 |
PRIORITY
[0001] This application is a Continuation of U.S. patent application Ser. No. 12/116,140, filed May 6, 2008, which claims priority to PCT application number PCT/EP2008/000378, filed Jan. 18, 2008, published as WO 2009/089847 A1, which is incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to an image processing method and apparatus for improving the quality of an acquired image.
BACKGROUND
[0003] It is well known to apply filters to images to improve their characteristics.
[0004] U.S. Pat. No. 7,072,525, Covell discloses an adaptive filter for filtering a target version of a visual image that is produced by processing an original version of the visual image, the characteristics of the adaptive filter being determined in accordance with one or more characteristics of the original version of the visual image. The orientation and/or strength of filtering of the adaptive filter are adjusted based on local properties of the original image, which can enable the adaptive filter to avoid introducing blurring across true edges in the image.
[0005] U.S. Pat. No. 6,823,086, Dolazza discloses a system for adaptively filtering an image so as to reduce a noise component associated with the image. The system includes an image analyzer for determining image parameters related to the image. The system also includes a spatial filter, having an adjustable kernel responsive to the image parameters, for filtering the image sequence. The image analyzer manipulates the filter kernel as a function of the image parameters so that the system produces a filtered image, adaptable in real time, as a function of the unfiltered image, external rules, predetermined constraints, or combinations thereof. The spatial filter includes a time-invariant section and an adaptable section. The time-invariant section applies a plurality of filters to the image, each of the filters having a distinct frequency response, so as to produce a plurality of distinct filtered outputs. The adaptable section scales each of the plurality of distinct filtered outputs with a corresponding distinct weighting value to produce a plurality of scaled filtered outputs, and combines the plurality of scaled filtered outputs to produce a composite filtered output.
[0006] In Covell and Dolazza, several 2-D low pass filters, each with a distinct frequency response, are applied to the image and the outputs are weighted in order to produce a composite filtered output.
[0007] As such, the complexity of U.S. Pat. No. 7,072,525 and U.S. Pat. No. 6,823,086 is high. Also, these patents require an image analyzer or another image in order to decide on the behavior of the adaptive filters, i.e. at least one pass over the original image and the target image is necessary.
[0008] U.S. Pat. No. 6,335,990, Chen et al, discloses filtering in the spatial and temporal domain in a single step with filtering coefficients that can be varied depending upon the complexity of the video and the motion between the adjacent frames. The filter comprises: an IIR filter, a threshold unit, and a coefficient register. The IIR filter and threshold unit are coupled to receive video data. The IIR filter is also coupled to the coefficient register and the threshold unit. The IIR filter receives coefficients, a, from the coefficient register and uses them to filter the video data received. The IIR filter filters the data in the vertical, horizontal and temporal dimensions in a single step. The filtered data output by the IIR filter is sent to the threshold unit. The threshold unit compares the absolute value of the difference between the filtered data and the raw video data to a threshold value from the coefficient register, and then outputs either the raw video data or the filtered data.
[0009] Chen uses an IIR filter and a threshold unit and output the raw video data or filtered data. As such, the IIR filter operates on its previous outputs and the pixel values.
[0010] Referring to FIG. 1 , US 2004/0213478, Chesnokov, discloses an image processing method comprising the step of processing an input signal to generate an adjusted output signal, wherein the intensity values I(x,y) for different positions (x,y) of an image are adjusted to generate an adjusted intensity value I′(x,y) in accordance with:
[0000] I out =Σ i=0 N α i ( I )LPFΩ i [P i ( F ( I ))]· Q i ( F ( I ))+(1−α i ) I,
[0000] where P i (γ) is an orthogonal basis of functions of γ defined in the range 0<γ<1; Q i (•) are anti-derivatives of P i (•): Q i (F(I))=∫ 0 F(i) P i (η)dη or an approximation thereto; LPF Ω [•] is an operator of low-pass spatial filtering; Ω i is a cut-off frequency of the low-pass filter; F(•) is a weighting function; and where 0<α<1.
[0011] The output of the weighting function F(•) is monotonically decreasing with higher values of the pixels. There is a feedback from the output of the filtered sequence and the method can receive information other than from the image. For example, an amplification factor can be added to the linear or the logarithmic multiplication block and can be computed from a preview using an integral image. As such, in Chesnokov, significant processing steps are applied to the input signal, making the method quite complex and the output image is a weighted sum of the original and the processed image.
SUMMARY OF THE INVENTION
[0012] A technique is provided of processing an image. Multiple pixels are traversed in a single pass over the image. An inverting function is applied to the pixels. A recursive filter is applied to one or more inverted pixel values. The filter has one or more parameters derived from previously traversed pixel values of the image. The one or more pixel values are combined with the one or more parameters to provide processed pixel values for a processed image.
[0013] The image may include one or a combination of YCC or RGB format. For example, the image may include RGB format and the inverting function may invert a combination of one or more color plane values for a pixel. The image may include YCC format and the inverting function may invert an intensity value for a pixel.
[0014] The traversing may include one or a combination of: row wise; column wise; or traversing a path across the image.
[0015] The method may include providing an estimate of the average of the red, green and blue planes from previously traversed pixel values of the image, providing correction terms for one or more of the planes, where the correction terms are dependent on color channel average estimates, and where the combining includes multiplying a pixel value with a correction term. The correction terms may be limited by respective upper and lower thresholds.
[0016] The combining may include a linear or a logarithmic combination. The combining may include multiplying a pixel value, a correction term and a filter parameter for the pixel to provide a processed pixel value for a processed image.
[0017] The method may include providing an estimate of the average of red, green and blue channels as follows:
[0000] R =β· R + (1−β)· G ( i,j, 1)
[0000] G =β· G + (1−β)· G ( i,j, 2)
[0000] B =β· B + (1−β)− G ( i,j, 3),
[0000] where:
G(i,j,k) includes the pixel value for the respective red (R), green (G) or blue (B) color plane; and β is a coefficient between 0 and 1.
[0018] The correction terms γ R ,γ B for the red and blue color planes may include:
[0000]
γ
R
=
G
_
R
_
·
[
(
1
-
a
)
·
R
_
+
255
·
a
]
[
(
1
-
a
)
·
G
_
+
255
·
a
]
and
γ
B
=
G
_
B
_
·
[
(
1
-
a
)
·
B
_
+
255
·
a
]
[
(
1
-
a
)
·
G
_
+
255
·
a
]
[0000] where:
R , G , B comprise said color channel average estimates; and a is a positive value less than 1. The values of γ R and γ B may be limited to between 0.95 and 1.05
[0019] The recursive filter parameters H(i,j) may include:
[0000] H ( i,j )= αH ( i,j− 1)+(1−α)( f ( G ( i,j,k )))
[0000] where:
α is the pole of the filter; G(i,j,k) is the pixel value for the respective red (R), green (G) or blue (B) color plane, or combinations thereof; and f(G(i,j,k)) is the inverting function. The value of α may be between 0.05 and 0.8.
[0020] The inverting function may include the following:
[0000]
f
(
G
(
i
,
j
,
k
)
,
a
,
δ
)
=
(
1
-
a
+
255
·
a
max
(
δ
,
(
G
(
i
,
j
,
1
)
+
G
(
i
,
j
,
2
)
+
G
(
i
,
j
,
3
)
)
/
3
)
)
[0000] where:
a is a positive value less than 1; and δ is used in order to avoid division by zero and to amplify dark pixels.
[0021] The inverting function may include the following:
[0000]
f
(
Y
(
i
,
j
)
,
a
,
δ
)
=
(
1
-
a
+
255
·
a
max
(
δ
,
Y
(
i
,
j
)
)
)
[0000] where Y(i,j) is said pixel intensity value; a is a positive value less than 1; and δ is used in order to avoid division by zero and to amplify dark pixels.
[0022] The combining may include:
[0000] G 1 ( i,j, 1)= G ( i,j, 1)· H ( i,j )·γ R
[0000] G 1 ( i,j, 2)= G ( i,j, 2)· H ( i,j )
[0000] G 1 ( i,j, 3)= G ( i,j, 3)· H ( i,j )·γ B
[0000] where:
γ R ,γ B is the correction terms;
H(i,j) is the filter parameter; and
G(i,j,k) is the pixel value for the respective red (R), green (G) or blue (B) color plane, or combinations thereof.
[0023] The combining may include:
[0000]
G
1
(
i
,
j
,
1
)
=
D
-
D
(
1
-
G
(
i
,
j
,
1
)
D
)
ɛ
H
(
i
,
j
)
γ
R
,
G
1
(
i
,
j
,
2
)
=
D
-
D
(
1
-
G
(
i
,
j
,
2
)
D
)
ɛ
H
(
i
,
j
)
,
G
1
(
i
,
j
,
3
)
=
D
-
D
(
1
-
G
(
i
,
j
,
3
)
D
)
ɛ
H
(
i
,
j
)
γ
B
[0000] where:
γ R ,γ B is the correction terms;
H(i,j) is the filter parameter;
G(i,j,k) is the pixel value for the respective red (R), green (G) or blue (B) color plane, or combinations thereof;
D is the maximum permitted pixel value; and
ε is a constant whose with a value between 1 and 3.
[0024] The image may be in YCC format and the recursive filter parameters H(i,j) may include:
[0000] H ( i,j )=α H ( i,j− 1)+(1−α)( f ( Y ( i,j )))
[0000] where:
α is the pole of the IIR filter;
Y(i,j) is said pixel intensity value; and
f(Y(i,j)) is said inverting function.
[0025] The inverting function may include:
[0000]
f
(
Y
(
i
,
j
)
,
δ
)
=
Y
(
i
,
j
+
1
)
max
(
δ
,
Y
(
i
,
j
)
)
[0000] where:
δ is used in order to avoid division by zero.
[0026] The combining may include:
[0000] Y 1 ( i,j )= Y ( i,j )[1+ε( i,j )·(1− H ( i,j ))]
[0000] where:
H(i,j) is said filter parameter; and
ε(i,j) is a gain factor.
[0027] The parameter ε(i,j) may be constant or varies for the image, or a combination thereof.
[0028] The steps may be iteratively applied to one or more successively processed images that are respectively adapted to improve image luminance or image sharpness or both.
[0029] A one-pass image technique is also provided that uses an IR filter to improve the quality of pictures, using only one image and with efficient use of processor resources.
[0030] In one embodiment automatic correction is provided of uneven luminance in the foreground/background of an image. This implementation improves quality especially where the background is more illuminated/or darker than the foreground.
[0031] In another embodiment, an estimate of the average of the red, green and blue channels is provided while another recursive filter filters a term that has a component inversely proportional with the values of each color plane pixel value or the intensity value. Its output is multiplied with one or more correction terms dependent on the color channel(s) and preferably limited by two thresholds. The enhanced pixel value is obtained by using a linear or logarithmic model.
[0032] Using the embodiment, as well as an automatic correction of uneven luminance in the foreground/background, color boost is also obtained.
[0033] In the first embodiment, the average values of each color channel are not used for comparison purposes and they can be replaced by sliding averaging windows ending on the pixel being processed. In any case, these average values are used to determine correction terms which in turn are used to avoid over-amplification of red or blue channels.
[0034] Coefficients of the IIR filter may be fixed, rather than employ adaptive filters. As such, the present method involves one pass through an image, while the output of one filter does not have to be used as an input to another filter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] An embodiment of the invention will now be described by way of example, with reference to the accompanying drawings, in which:
[0036] FIG. 1 is a block diagram of a conventional image enhancement system; and
[0037] FIG. 2 is a block diagram of an image enhancement system according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0038] Referring now to FIG. 2 , an acquired image G is supplied for filtering according to the present invention. While the embodiment is described in terms of processing an image in RGB space, the invention can be applied to luminance channels only or other color spaces.
[0039] Only one input image, G, is used and a running average on each color channel is computed 20 as each pixel value is read. Therefore for each pixel G(i,j,k) of each plane k=1 . . . 3, we compute:
[0000] R =β· R +(1−β)· G ( i,j, 1)
[0000] G =β· G +(1−β)· G ( i,j, 2)
[0000] B =β· B +(1−β)· G ( i,j, 3),
[0000] where β is a coefficient between 0 and 1.
[0040] Another variant is to compute on each color channel, the sum of 2N+1 pixel values around the pixel G(i,j,k) and divide by 2N+1.
[0041] From the moving average values, R , G , B , correction terms γ R ,γ B are calculated, step 25 , as follows:
[0000]
γ
R
=
G
_
R
_
·
[
(
1
-
a
)
·
R
_
+
255
·
a
]
[
(
1
-
a
)
·
G
_
+
255
·
a
]
and
γ
B
=
G
_
B
_
·
[
(
1
-
a
)
·
B
_
+
255
·
a
]
[
(
1
-
a
)
·
G
_
+
255
·
a
]
[0042] Preferably, both correction terms, γ R and γ B values are limited within a chosen interval (e.g. between 0.95 and 1.05; if any of γ R and γ B values is below 0.95 their value is set to 0.95; if any of γ R and γ B values is above 1.05 their value is set to 1.05). This prevents over-amplification of the red and blue channels in further processing.
[0043] In parallel with generating the moving average values, the pixels are parsed on rows or columns and for each pixel of a color plane G(i,j,k), a coefficient H(i,j) is calculated as follows:
[0000]
H
(
i
,
j
)
=
α
H
(
i
,
j
-
1
)
+
(
1
-
α
)
(
1
-
a
+
255
·
a
max
(
δ
,
(
G
(
i
,
j
,
1
)
+
G
(
i
,
j
,
2
)
+
G
(
i
,
j
,
3
)
)
/
3
)
)
[0044] In FIG. 2 , this processing is broken into step 30 :
[0000]
f
(
G
(
i
,
j
,
k
)
,
a
,
δ
)
=
(
1
-
a
+
255
·
a
max
(
δ
,
(
G
(
i
,
j
,
1
)
+
G
(
i
,
j
,
2
)
+
G
(
i
,
j
,
3
)
)
/
3
)
)
[0000] followed by a recursive filter, step 40 :
[0000] H ( i,j )=α H ( i,j− 1)+(1−α)( f ( G ( i,j,k ), a ,δ))
[0000] where:
a is a positive value less than 1 (e.g. a=0.125); and
α is the pole of the corresponding recursive filtering, e.g. α can have values between 0.05 and 0.8).
[0045] The comparison with δ is used in order to avoid division by zero and to amplify dark pixels (e.g. δ=15). The initial value H(1,1) can have values between 1 and 2.
[0046] Using this filter, darker areas are amplified more than illuminated areas due to the inverse values averaging and, therefore, an automatic correction of uneven luminance in the foreground/background is obtained.
[0047] It will be seen from the above that the recursive filter, H, doesn't filter the pixel values. For example, if a=α=⅛ and δ=15, the filter 30 / 40 is filtering a sequence of numbers that varies between 1 and 3 depending on actual pixel value G(i,j,k) and the preceding values of the image. If the filter 40 simply uses as input the pixel values G(i,j,k), it generates a simple low pass filtered image, with no luminance correction.
[0048] In one implementation of the embodiment, the modified pixel values, G 1 (i,j,k), are given by a linear combination, step 50 , of the filter parameters H and the correction terms γ R ,γ B :
[0000] G 1 ( i,j, 1)= G ( i,j, 1)· H ( i,j )·γ R
[0000] G 1 ( i,j, 2)= G ( i,j, 2)· H ( i,j )
[0000] G 1 ( i,j, 3)= G ( i,j, 3)· H ( i,j )·γ B .
[0049] One more complex alternative to the linear model is a logarithmic model. In such an implementation, the output pixel G i (i,j,k) corresponding to the enhanced color plane (R/G/B color planes), is as follows:
[0000]
G
1
(
i
,
j
,
1
)
=
D
-
D
(
1
-
G
(
i
,
j
,
1
)
D
)
ɛ
H
(
i
,
j
)
γ
R
,
G
1
(
i
,
j
,
2
)
=
D
-
D
(
1
-
G
(
i
,
j
,
2
)
D
)
ɛ
H
(
i
,
j
)
,
G
1
(
i
,
j
,
3
)
=
D
-
D
(
1
-
G
(
i
,
j
,
3
)
D
)
ɛ
H
(
i
,
j
)
γ
B
[0000] where:
D is the maximum permitted value (e.g. 255 for 8 bit representation of images); and
ε is a constant whose indicated values are between 1 and 3.
[0050] Examination of the formula above shows that only values smaller than D may be obtained. In this implementation, the degree of color and brightness boost are obtained by varying the pole value (α) and the logarithmic model factor (ε).
[0051] The computations can be adapted for the YCC or other color spaces. For example, when using YCC color space in the embodiment of FIG. 2 , there is no need to compute the correction terms γ R , γ B , and ε=1 for the Y channel if the logarithmic model is used. The inverting function for the Y channel is therefore:
[0000]
f
(
Y
(
i
,
j
)
,
a
,
δ
)
=
(
1
-
a
+
255
·
a
max
(
δ
,
Y
(
i
,
j
)
)
)
.
[0052] The linear model can be applied for the luminance channel and the logarithmic model can be used for the chrominance channels using the H(i,j) coefficient computed on the luminance channel.
[0053] This approach leads to computational savings and add the possibility of adjusting the color saturation by using a different positive value for ε (e.g. ε=0.9) when computing the new chrominance values. The brightness of the enhanced image can be varied by multiplying the Y channel with a positive factor, ε, whose value can be different than the value of ε used for the chrominance channels.
[0054] In a second embodiment of the invention, the processing structure of FIG. 2 can be used to sharpen an image.
[0055] In this embodiment, the image is preferably provided in YCC format and the processing is performed on the Y channel only. The ratio of the next pixel and the current pixel value is computed and filtered with a one pole IIR filter (e.g. α= 1/16), step 40 . The operations can be performed on successive or individual rows or columns. The initial H coefficient is set to 1 and in case of operating on row i we have:
[0000]
H
(
i
,
j
)
=
α
H
(
i
,
j
-
1
)
+
(
1
-
α
)
Y
(
i
,
j
+
1
)
max
(
δ
,
Y
(
i
,
j
)
)
,
[0000] where:
α is the pole of the IIR filter.
[0056] Again, this processing can be broken down in step 30 :
[0000]
f
(
Y
(
i
,
j
)
,
δ
)
=
Y
(
i
,
j
+
1
)
max
(
δ
,
Y
(
i
,
j
)
)
[0000] followed by the recursive filter, step 40 :
[0000] H ( i,j )=α H ( i,j− 1)+(1−α)( f ( Y ( i,j ),δ))
[0057] Again, the comparison with δ is used in order to avoid division by zero (δ is usually set to 1). H(i,j) is a coefficient that corresponds to the current pixel position (i, j) of the original image. The initial coefficient can be set to 1 at the beginning of the first row or at the beginning of each row. In the first case, the coefficient computed at the end of the one row is used to compute the coefficient corresponding to the first pixel of the next row.
[0058] The enhanced pixel value Y 1 (i,j) is given by the following formula:
[0000] Y 1 ( i,j )= Y ( i,j )[1+ε( i,j )·(1− H ( i,j ))]
[0000] where ε(i,j) can be a constant gain factor or a variable gain depending on the H coefficients. Another alternative for ε(i,j) is to use the difference between consecutive pixels or the ratio of successive pixel values. For example, if the difference between successive pixels is small (or the ratio of consecutive pixel values is close to 1) the value of ε(i,j) should be lower, because the pixel might be situated in a smooth area. If the difference is big (or the ratio is much higher or much lower than 1), the pixels might be situated on an edge, therefore the value of ε(i,j) should be close to zero, in order to avoid possible over-shooting or under-shooting problems. For intermediate values, the gain function should vary between 0 and a maximum chosen gain. An example of ε(i,j) according to these requirements has a Rayleigh distribution.
[0059] In some implementations, a look up table (LUT) can be used if a variable ε(i,j) is chosen, because the absolute difference between consecutive pixels has limited integer values.
[0060] This method is highly parallelizable and its complexity is very low. The complexity can be further reduced if LUTs are used and some multiplications are replaced by shifts.
[0061] Furthermore, this second embodiment can also be applied to images in RGB space.
[0062] The second embodiment can be applied in sharpening video frames either by sharpening each individual video frame or identified slightly blurred frames.
[0063] In each embodiment, the pixels can be parsed using any space-filling curves (e.g. Hilbert curves), not only by rows or columns. The corrected image can be thought as a continuously modified image, pixel by pixel, through a path of a continuously moving point.
[0064] It will also be seen that the image sharpening image processing of the second embodiment can be applied after the luminance correction of the first embodiment to provide a filtered image with even superior characteristics to either method implemented independently.
[0065] Indeed, either method can be applied in conjunction with other image processing methods as required for example following the processing described in PCT Application No. PCT/EP2007/009939 and U.S. application Ser. No. 11/856,721, which are incorporated by reference.
[0066] While an exemplary drawings and specific embodiments of the present invention have been described and illustrated, it is to be understood that that the scope of the present invention is not to be limited to the particular embodiments discussed. Thus, the embodiments shall be regarded as illustrative rather than restrictive, and it should be understood that variations may be made in those embodiments by workers skilled in the arts without departing from the scope of the present invention.
[0067] In addition, in methods that may be performed according to preferred embodiments herein and that may have been described above, the operations have been described in selected typographical sequences. However, the sequences have been selected and so ordered for typographical convenience and are not intended to imply any particular order for performing the operations, except for those where a particular order may be expressly set forth or where those of ordinary skill in the art may deem a particular order to be necessary.
[0068] In addition, all references cited herein, as well as U.S. applications 60/945,558, 10/764,339, 12/042,335, 11/753,098, 11/752,925, 60/944,046, 11/767,412, 11/624,683, and 11/856,721, and US published application 2005/0041121, 2006/0204110, 2006/0120599, 2006/0098890, 2006/0039690, 2006/0285754, 2007/0189748, 2008/0037840, and 2007/0269108, and U.S. Pat. No. 7,352,394, as well as the background, invention summary, abstract and brief description of the drawings, are each incorporated by reference into the detailed description of the preferred embodiments as disclosing alternative embodiments. | A method of processing an image includes traversing pixels of an image in a single pass over the image. An inverting function is applied to the pixels. A recursive filter is applied to the inverted pixel values. The filter has parameters which are derived from previously traversed pixel values of the image. A pixel value is combined with a filter parameter for the pixel to provide a processed pixel value for a processed image. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for supplying oil in engines. More particularly, the present invention pertains to an improved apparatus for supplying oil to a hydraulic variable valve performance mechanism and a structure for supplying lubricant oil.
2. Description of the Related Art
Many existing engines are equipped with a mechanism for varying characteristics, such as valve timing and lift, of a set of intake valves or a set of exhaust valves in accordance with the engine running conditions. This enhances the power and performance of the engine and reduces undesirable emissions. Japanese Examined Patent Publication No. 3-13403 discloses a variable valve performance mechanism that hydraulically changes valve lift and an apparatus for lubricating the moving parts in the variable valve performance mechanism.
As shown in FIGS. 6(a) and 6(b), a mechanism 71 for varying valve performance includes a rocker shaft 73, in which an oil pressure passage 72 is defined. A low speed rocker arm 74 and a high speed rocker arm 75 are pivotally mounted on the rocker shaft 73 in association with a valve. The rocker arms 74, 75 are pivoted about the axis of the rocker shaft 73 by a low speed cam and a high speed cam (neither of which is shown), respectively. Pivoting of the low speed rocker arm 74 about the axis of the rocker shaft 73 opens and closes the valve. "Right" and "left" as used below refer to the right and left directions of FIGS. 6(a) and 6(b).
A hole 76 extends in the low speed and high speed rocker arms 74, 75 parallel to the rocker shaft 73. A segmented coupling pin 77 is slidably fitted in the hole 76. An oil chamber 78 is defined between the right end of the pin 77 and the right end of the hole 76. The chamber 78 communicates with the oil pressure passage 72. A coil spring 79 extends between the left end of the coupling pin 77 and the left end of the hole 76.
When moved to a position close to the left end of the hole 76 against the force of the coil spring 79 as shown in FIG. 6(b), the coupling pin 77 couples the low speed rocker arm 74 with the high speed rocker arm 75. This causes the low speed rocker arm 74 to pivot integrally with the high speed rocker arm 75. As a result, the valve is opened and closed by the high speed cam by way of the low speed and high speed rocker arms 74, 75. This increases the valve lift. When the coupling pin 77 is moved to the right end of the hole 76 by the force of the coil spring 79, as shown in FIG. 6(a), the low speed rocker arm 74 is uncoupled from the high speed rocker arm 75. This causes the valve to be opened and closed by the low speed cam by way of the low speed rocker arm 74. This decreases the valve lift.
The valve lift is generally changed based on the engine speed. For example, when the engine is running at a lower speed, the valves are opened and closed by the low speed cam as illustrated in FIG. 6(a) to decrease the amount of air drawn into the engine. When the engine is running at a higher speed, the valves are opened and closed by the high speed cam to increase the amount of air drawn into the engine.
An oil passage 85 is connected to the oil pressure passage 72 for supplying oil to the passage 72. The supplied oil is used to lubricate the low speed and high speed cams. The sliding surfaces between the cams and the rocker arms 74, 75 also need lubrication. The passages 72, 85 are connected to an oil pump 83 via a switching valve 87. The switching valve 87 includes a variable orifice 86 and is connected to an oil pump 83. The oil pump 83 is driven by a crankshaft of the engine (not shown). The pump 83 draws oil from an oil pan 84 and discharges the oil to the switching valve 87.
When the engine is running at a high speed, the switching valve 87 sends oil from the oil pump 83 to the oil pressure passage 72 as illustrated in FIG. 6(b). The oil is then flows to the passage 85. In this state, the restriction amount of the orifice 86 is controlled to deliver enough oil to the chamber 78 to displace the pin 77 against the force of the spring 79 as shown in FIG. 6(b). Thus, the oil pressure actuates the mechanism 71 and switches the cams for increasing the valve lift. Part of the oil passing through the oil passage 85 is injected from holes 88 for lubricating the sliding parts of the cams and the rocker arms 74, 75.
When the engine is running at a low speed, the switching valve 87 sends oil from the oil pump 83 to the oil passage 85 as illustrated in FIG. 6(a). The oil then flows to the passage 72. In this state, the restriction amount of the orifice 86 is controlled so that the oil pressure in the chamber 78 is too low to displace the pin 77 against the force of the spring 79. As a result, the mechanism 71 switches the cams to decrease the valve lift. Part of the oil passing through the oil passage 85 is supplied to the cams for lubricating the sliding parts of the cams and the rocker arms 74, 75.
However, when the engine is running at a low speed, the power of the oil pump 83, which is driven by rotation of the crankshaft, is also lowered. This results in less oil being discharged from the pump 83. At low speeds, oil is supplied to the oil pressure passage 72 via the oil passage 85. In other words, after part of the oil in the passage 85 is diverted to the sliding parts, the remaining oil flows to the oil pressure passage 72. Accordingly, the oil pressure in the passage 72 is lowered. Thus, when the engine is running at a low speed, it takes a significant amount of time to generate enough oil pressure in the oil passage 72 to actuate the mechanism 71 in the oil passage 72. Under these conditions the mechanism 71 has a relatively slow response.
When the engine is running at a high speed, oil is supplied to the oil passage 85 via the oil pressure passage 72. The pressure of the oil in the passage 72 falls when the mechanism 71 is actuated. Accordingly, the oil pressure in the oil passage 85 is lowered. This reduces the amount of oil supplied to the sliding parts. Thus, the lubrication of the sliding parts may be insufficient.
SUMMARY OF THE INVENTION
Accordingly, it is an objective of the present invention to provide an oil supplying apparatus in engines that always supplies a sufficient amount of oil to the variable valve performance mechanism and sliding parts of the engine at any given running state of the engine.
To achieve the foregoing and other objectives and in accordance with the purpose of the present invention, a apparatus for supplying lubricant oil to an engine is provided. The engine has a crankshaft, a combustion chamber, a valve that selectively opens and closes the combustion chamber. The said valve has a timing relationship to the crankshaft and lift characteristic, control means for hydraulically altering at least one of the timing relationship and the lift characteristic and a lubricant passage connected with the control means to supply oil to a mechanism within the engine. The apparatus includes an oil pump, an auxiliary lubricant passage for supplying the oil to the mechanism, means for restricting the oil supplied from the oil pump to the auxiliary lubricant passage, actuating means for actuating the restricting means when engine speed is lower than a predetermined value.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:
FIG. 1 is a diagrammatic cross-sectional view illustrating a variable valve performance mechanism and a lubricating mechanism according to a first embodiment;
FIG. 2 is a diagram illustrating an oil circuit for supplying oil to the mechanism of FIG. 1;
FIG. 2(a) is a flowchart illustrating the operation of the ECU 38;
FIG. 3 is a diagram illustrating a variable valve performance mechanism and a lubricating mechanism according to a second embodiment;
FIG. 4 is an exploded perspective view illustrating a variable valve lift mechanism according to the second embodiment;
FIG. 5 is a diagram illustrating an oil circuit for supplying oil to the mechanism of FIG. 4;
FIG. 6(a) is a diagram illustrating a prior art oil supply circuit; and.
FIG. 6(b) is a diagram illustrating a prior art oil supply circuit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of the present invention will now be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, a camshaft 11 is rotatably supported on a cylinder head (not shown) of an engine. The camshaft 11 is provided with cams 13. Each cam 13 corresponds a valve 12 of one of intake ports and exhaust ports. The cams 13 rotate with the camshaft 11 thereby selectively opening and closing the valves 12. Sliding parts of the valves 12 and the cams 13 are lubricated with oil supplied from a first oil passage 20 or a second oil passage 21.
A variable valve timing mechanism 31 is provided at one end of the camshaft 11. The mechanism 31 advances or retards the rotational phase of the camshaft 11 relative to the crankshaft 24.
The mechanism 31 includes a pulley 31a, which is coupled to the crankshaft 24 by a timing belt 24a. The pulley 31a is coupled to the camshaft 11 by a ring gear 25, which functions as a hydraulic piston. The ring gear 25 has helical splines 26a, 26b on its inner surface and its outer periphery. The camshaft 11 is coupled with the pulley 31a by the engagement of the helical splines 26a, 26b with outer teeth formed on the camshaft 11 and inner teeth formed on the pulley 31a. A phase advancing oil pressure chamber 27 and a phase retarding oil pressure chamber 28 are located to the sides of the ring gear 25. Oil is supplied to and drained from the oil pressure chambers 27, 28 by a phase advancing oil conduit 32 and a phase retarding oil conduit 33. This moves the ring gear 25 along the axis of the camshaft 11. Movement of the ring gear 25 changes the rotational phase of the pulley 31a relative to the camshaft 11. As a result, the rotational phase of the camshaft 11 relative to the crankshaft 24 is selectively advanced or retarded.
FIG. 2 illustrates a hydraulic circuit that supplies oil to and drains oil from the variable valve timing mechanism 31 (VVTi) and also lubricates sliding surfaces of the valves 12 and the cams 13.
The VVTi 31 is connected to an oil control valve (OCV) 34 by oil conduits 32, 33. An oil pressure passage 35 and a first oil passage 20 are connected to the OCV 34. The oil pressure passage 35 is communicated with an oil pan 37 provided in the lower portion of the engine via an oil pump 36. The pump 36 is coupled to and rotated by the crankshaft 24.
The OCV 34 is controlled by an electronic control unit (ECU) 38. The ECU 38 receives signals from various sensors (not shown) that detect the running state of the engine such as the engine speed. The OCV 34 is a two position type electromagnetic valve having four ports, an electromagnetic solenoid 39 and a coil spring 40. The OCV 34 further has two port combinations, A and B. When the solenoid 39 is not energized, the OCV 34 employs the A combination, which is held in alignment with the conduits 32, 33, by the force of the coil spring 40. When the solenoid 39 is energized, the OCV 34 is moved so that the B combination is aligned with the conduits 32, 33.
When the A combination is selected, the oil pressure passage 35 is communicated with the phase advancing oil conduit 32, and the first oil passage 20 is communicated with the phase retarding oil conduit 33. In this state, the pump 36 supplies oil in the oil pan 37 to the VVTi 31 via the oil pressure passage 35, the OCV 34 and the phase advancing oil conduit 32. The oil in the VVTi 31 is supplied to the sliding parts via the phase retarding conduit 33, the OCV 34 and the first oil passage 20. The oil is then returned to the oil pan 37. The VVTi 31, to which oil is supplied from the phase advancing oil conduit 32, advances the rotational phase of the camshaft 11 relative to the rotational phase of the crankshaft 24. This advances the actuation of the valves 12.
When the B combination is selected based on signals from the ECU 38, the oil pressure passage 35 is communicated with the phase retarding oil conduit 33 and the first oil passage 20 is communicated with the phase advancing oil conduit 32. In this state, the pump 36 supplies oil from the oil pan 37 to the VVTi 31 via the oil pressure passage 35, the OCV 34 and the phase retarding oil conduit 33. The oil in the VVTi 31 is supplied to the sliding parts via the phase advancing conduit 32, the OCV 34 and the first oil passage 20. The VVTi 31, to which oil is supplied from the phase retarding oil conduit 33, rotates the rotational phase of the camshaft 11 relative to the rotational phase of the crankshaft 24. This retards the actuation of the valves 12.
The second oil passage 21 is connected to the oil pressure passage 35 with an oil switching valve (OSV) 41 in between. The passage 21 is connected to the passage 35 upstream of the OCV 34. An orifice 42 is located between the OSV 41 and the second oil passage 21 for controlling the oil pressure in the passage 21. The OSV 41 is also controlled by the ECU 38.
The OSV 41 is a two position type electromagnetic valve having two ports, an electromagnetic solenoid 43 and a coil spring 44. The OSV 41 has two combinations A and B. When the solenoid 43 is not energized, the A combination is employed and is held in an operative position by the force of the coil spring 44, and the B combination is inoperative. In this state, the second oil passage 21 is disconnected from the oil pressure passage 35. When the solenoid 43 is energized, the B combination is held in an operative position, and the A combination is inoperative. In this state, the second oil passage 21 is communicated with the oil pressure passage 35.
When controlling the OSV 41, the ECU 38 computes the speed of the engine E based on a signal from an engine speed sensor S. When the engine E is running at a low speed, the ECU 38 causes the OSV 41 to select the A combination to prevent oil from flowing to the second oil passage 21. In this state, all the oil discharged by the pump 36 is supplied to the oil pressure passage 35. That is, even if the engine is running at a low speed and the pump 36 is discharging a relatively small amount of oil, the VVTi 31 is provided with a sufficient amount of oil. Therefore, the oil pressure of the oil delivered to the VVTi 31 is relatively high.
When the engine speed increases gradually and reaches a high speed range, which is equal to or higher than 5000 rpm, the ECU 38 controls the OSV 41 to switch to the B combination. This causes oil to be supplied to the second oil passage 21. In the same manner as the oil supplied to the oil passage 20, the oil in the second oil passage 21 is supplied to the sliding parts from the holes 21a and returned to the oil pan 37. Therefore, the amount of oil delivered to the sliding parts is higher when the engine E is running at a higher speed. The operation of the engine E is stabilized accordingly. While the engine is running at high speed, the pump 36 is discharging a greater amount of oil. Thus, the operation of the VVTi 31 is not disturbed by the diversion of oil to the oil passage 21.
FIG. 2(a) is a flowchart illustrating the operation of the ECU 38.
The ECU 38 computes the engine speed NE based on signals from the engine speed sensor S at step 101. At step 102, the ECU 38 judges whether the engine speed NE is greater than a predetermined value, for example, 5000 rpm. If the determination is negative, the ECU 38 moves to step 103. At step 103, the ECU 38 stops sending signals to the OSV 41 to de-energize the solenoid 43 thereby causing the A combination of the OSV 41 to operate. As a result, the oil is not supplied to the second oil passage 21 and the VVTi 31 receives sufficient oil via the OCV 34 to provide ample oil pressure for actuating the VVTi 31.
When the engine is running at a low speed, oil is supplied to the sliding parts by the first oil passage 20, and the pressure in the passage 35 is maintained at a sufficient level for actuating the VVTi 31. In other words, even if the engine is running at a low speed, actuation of the VVTi 31 is reliable and responsive.
When the engine is running at a low speed, the second oil passage 21 is disconnected from the oil pressure passage 35. This allows all the oil discharged from the pump 36 to flow into the passage 35, which guarantees reliable and responsive actuation of the VVTi 31.
Further, when the engine E is running at a high speed, oil is supplied to the valves 12 and the cams 13 by both oil passages 20, 21. This delivers sufficient lubrication to the parts 12, 13. Therefore, when the engine E is running at a high speed, insufficient lubrication of the sliding parts will not occur. At this time, the pump 36 is discharging a relatively great amount of oil. Thus, the operation of the VVTi 31 is not disturbed by the diversion of some oil to the passage 21.
A second embodiment of the present invention will now be described with reference to FIGS. 3 to 5. In this embodiment, oil is supplied to a variable valve lift mechanism, a VVTi and sliding surfaces of valves and cams. The variable valve lift mechanism per se is well known in the art.
A camshaft 11 is rotatably supported on the cylinder head of an engine as shown in FIG. 3. The camshaft 11 is provided with a high speed cam 13a and pair of low speed cams 13b sandwiching the high speed cam 13a. The profiles of the low speed cams 13b differ from that of the high speed cam 13a. The valve lift of the valves 12 when actuated by the high speed cam 13a is greater than the valve lift of the valves 12 when actuated by the low speed cams 13b. When the engine is running at a low speed, the valves 12 are actuated by the low speed cams 13b for introducing a relatively small amount of air into the engine. When the engine is running at a high speed, the valves 12 are actuated by the high speed cam 13a for introducing a relatively great amount of air into the engine. Like the apparatus according to the first embodiment, oil is supplied to the sliding parts of the valves 12 (including a variable valve lift mechanism 15, which will be described below) and the cams 13a, 13b by the first oil passage 20 or the second oil passage 21.
The variable valve lift mechanism 15 is located between the cams 13a, 13b and the valves 12. As shown in FIG. 4, the mechanism 15 includes a rocker shaft 16 extending parallel to the camshaft 11. The rocker shaft 16 has a high speed rocker arm 17, which corresponds to the high speed cam 13a, and low speed rocker arms 18, which correspond to the low speed cams 13b. As shown in FIG. 4, the high speed rocker arm 17 is located between and corresponds to the pair of the low speed rocker arms 18.
The high speed and low speed rocker arms 17, 18 pivot about the axis of the rocker shaft 16. The lower distal end of each low speed rocker arm 18 is aligned with one of the valves 12. An oil passage 19 is defined in the rocker shaft 16 and is communicated with the low speed rocker arms 18.
When oil is supplied to the oil passage 19 to increase the pressure in the passage 19, a coupling pin in each associated set of rocker arms 17, 18 (see FIGS. 6(a) and 6(b)) is moved to a position to connect the low speed rocker arms 18 to the corresponding high speed rocker arm 17. In this state, the associated valves 12 are opened and closed by the high speed cam 13a by way of the high speed rocker arm 17 and the low speed rocker arms 18.
When the pressure in the passage 19 is decreased, the coupling pin is moved to a position to disconnect the low speed rocker arms 18 from the corresponding high speed rocker arm 17. In this state, the valves 12 are opened and closed by the low speed cams 13b by way of the low speed rocker arms 18.
As shown in FIG. 3, a VVTi 31 is provided on one end of the camshaft 11 for advancing or retarding the rotational phase of the camshaft 11 relative to the rotational phase of the crankshaft 24. FIG. 5 illustrates a hydraulic circuit of an apparatus for supplying oil to the sliding parts in the variable valve lift mechanism 15 and the VVTi 31.
As shown in FIG. 5, the oil passage 19 of the variable valve lift mechanism (VVTL) 15 is connected to the oil pressure passage 35 via an oil switching valve (OSV) 51, which is controlled by the ECU 38. The OSV 51 is connected to an oil receiver 52 provided in the cylinder head of the engine by an oil line 53. The oil receiver 52 receives oil supplied to the sliding parts from the first and second oil passages 20, 21.
The OSV 51 is a two position type electromagnetic valve having three ports, an electromagnetic solenoid 54 and a coil spring 55. The OSV 51 further includes two combinations, A and B, of the ports. When the solenoid 54 is not energized, the A combination is selected and held in position by the force of the coil spring 55. The A combination connects the oil line 53 with the oil passage 19 as shown in FIG. 5. When the solenoid 54 is energized, the B combination is selected. The B combination shuts off the oil line 53 and communicates the oil pressure passage 35 with the oil passage 19.
The OSV 51 is controlled to select the B combination for communicating the oil pressure passage 35 with the oil passage 19 thereby changing the cams actuating the valves 12 from the low speed cams 13b to the high speed cams 13a. In this state, oil is supplied to the oil passage 19 from the oil pressure passage 35 via the OSV 51. This increases the oil pressure in the passage 19. The increased oil pressure in the passage 19 actuates the variable valve lift mechanism 15 to change from the low speed cams 13b to the high speed cam 13a.
On the other hand, when changing from the high speed cam 13a to the low speed cams 13b, the OSV 51 is controlled to select the A combination for communicating the oil line 53 with the oil passage 19. This decreases the oil pressure in the passage 19 thereby actuating the variable valve lift mechanism 15 such that the low speed cams 13b actuate the valves 12. Further, when the oil line 53 is communicated with the passage 19, the passage 19 is filled with oil flowing from the oil receiver 52 via the line 53. This prevents air from entering the passage 19 when the variable valve lift mechanism 15 is not operating. Therefore, failure of the mechanism 15 caused by air in the passage 19 is avoided. The operation of the mechanism 15 is thus reliable and responsive. Descriptions of the OCV 34 and the OSV 41 are not repeated for the second embodiment since the operation of the OCV 34, which controls the VVTi 31, and the operation of the OSV 41, which controls the supply of oil to the second oil passage 21, are the same in both the first and the second embodiments.
The oil receiver 52 is located at a position higher than the variable valve lift mechanism 15. Therefore, locating the OSV 51 lower than the mechanism 15 does not cause air to enter the passage 19. This increases the number of places where the OSV 51 can be located, thus adding to the flexibility of the design.
It should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, it should be understood that the invention may take in the following forms.
(1) In the embodiments of FIGS. 1 to 5, the second oil passage 21 is shut off when the engine is running at a low speed. However, instead of shutting the second passage 21 off, the amount of oil supplied to the passage 21 may be decreased so that sufficient pressure in the passage 35 for actuating the VVTi 31 is maintained. In this case, the OSV 41 is replaced with a flow control valve.
(2) The VVTi 31 is not limited to the ring gear type, which is described above. That is, the oil supplying mechanism of the embodiments of FIGS. 1 to 5 may be adopted in a known vane type VVTi.
(3) In the first embodiments of FIGS. 1 to 5, sliding surfaces of the valves 12 and cams 13 (13a, 13b) are lubricated by oil from the first and second oil passages 20, 21. However, chains and gears of the engine may be also lubricated by the oil from the passages 20, 21.
(4) In the embodiments of FIGS. 1 to 5, the OSV 51 may be a relief valve.
(5) In the embodiments of FIGS. 1 to 5, the oil pump 36 is actuated by the crankshaft 25. However, the pump 36 may be electrically actuated. In this case, the driving force of the pump 36 is controlled based on the running state of the engine.
Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalence of the appended claims. | An engine has a crankshaft, a combustion chamber and a valve that selectively opens and closes the combustion chamber. The valve has a timing relationship to the crankshaft and lift characteristic. A control device hydraulically alters at least one of the timing relationship and the lift characteristic. A lubricant passage is connected with the control device to supply oil to a mechanism that is formed by engine parts slidably contacting one another within the engine. An auxiliary passage is provided for supplying the oil to the mechanism. Oil supplied from an oil pump to said auxiliary passage is restricted by an electromagnetic valve that is actuated based on the instruction from an electric controller when engine speed is lower than a predetermined value. | 5 |
CROSS-REFERENCES
[0001] This patent application claims the benefit of provisional patent application No. 661/620,133 to Richard P. Moewe, entitled “Coral Shelf System”, filed on Apr. 4, 2012, and which provisional application is fully incorporated by reference herein.
TECHNICAL FIELD
[0002] This invention relates to vivariums for displaying or exhibiting animals, and more particularly, to a vivarium wall device system that can be attached to a wall of the vivarium.
BACKGROUND
[0003] Vivariums include terrariums and aquariums. Aquariums are generally four sided glass tanks which are filled with water and used to display fish, crustaceans, and other aquatic life. It is not uncommon for an aquarium to have rocks and rock formations, tree branches, and other decorative artifacts placed on the bottom of tank for the marine life to move around, through and about. If there is a substantial volume of this material, it will not only cover the bottom of the tank but do so to a depth that the material starts to cover the bottom portion of the sidewalls of the aquarium as well. It sometimes may be desirable, for the overall appearance of the aquarium, to attach an object to an inside wall of the tank at a level above that of the other material placed in the tank. Heretofore, that has been difficult to do. For example, an artifact could be taped or glued to the wall of the tank, but this requires draining the tank and refilling it. In addition, prolonged submersion in the water may cause the glue or tape to lose its adhesiveness, causing the object to dislodge. A hole could be drilled through the sidewall of the aquarium to allow the object to be set in place using a screw or the like. This again requires draining and refilling of the tank, in addition to providing a waterproof seal about the hole. If the object is later removed, the hole must be filled which may leave an unsightly appearance.
[0004] In addition, it has been difficult to attach any sort of shelf or shelves to the walls of an aquarium.
[0005] In addition, similar problems for attaching shelves or other items to terrariums and vivariums in general are known.
[0006] Thus, there is a need for a system that can overcome the above and other limitations.
SUMMARY OF THE INVENTION
[0007] The disclosed invention relates to a vivarium wall device system comprising: a piece of coral, the piece of coral having a glass-side surface, upper surface, lower surface, and three side surfaces, and where the glass-side surface is generally flat and regular; a vivarium wall attachment means comprising: a first inside magnet, generally permanently attached to the glass-side surface; a first outside magnet, configured to be removeably and magnetically attachable to the first inside magnet; where when the first inside magnet is configured to be located inside the vivarium and magnetically attach to a first outside magnet located outside of the vivarium, and where the magnetic attraction occurs across a vivarium wall, and the coefficient of friction of the vivarium wall and the magnetic force tend to hold the piece of coral in place on the vivarium wall.
[0008] The disclosed invention also relates to a vivarium wall device system comprising: a wood piece, the wood piece having a glass-side; a vivarium wall attachment means comprising: a first inside magnet, generally permanently attached to the glass-side; a first outside magnet, configured to be removeably and magnetically attachable to the first inside magnet; where when the first inside magnet is configured to be located inside the vivarium and magnetically attach to a first outside magnet located outside of the vivarium, and where the magnetic attraction occurs across a vivarium wall, and the coefficient of friction of the vivarium wall and the magnetic force tend to hold the wood piece in place on the vivarium wall.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present disclosure will be better understood by those skilled in the pertinent art by referencing the accompanying drawings, where like elements are numbered alike in the several figures, in which:
[0010] FIG. 1 is a cross-sectional view of the vivarium wall device system;
[0011] FIG. 2 is a perspective view showing the vivarium wall device system installed on an vivarium wall;
[0012] FIG. 3 is a side view of another embodiment of the vivarium wall device system; and
[0013] FIG. 4 is a cross-sectional view of a wood embodiment of the vivarium wall device system.
DETAILED DESCRIPTION
[0014] FIG. 1 is a cross-sectional view of one embodiment of the disclosed vivarium wall device system 10 . A natural piece of coral 14 comprises the shelf section of the system. The coral 114 may be naturally shaped on all but the glass-side surface 18 that is that all other sides of the coral may retain its natural shape. The glass-side 18 of the coral will be cut or machined to a flat surface. The coral 14 may also be cut to form a generally “shelf” shape, with an upper surface 22 , lower surface 26 , and three side surfaces 30 , 34 , 38 in addition to the glass-side 18 surface. The upper surface 22 , lower surface 26 , and three side surfaces 30 , 34 , 38 may be relatively flat and uniform having a generally man-made shelf shape, or in other embodiments, the coral 14 may have a very irregular shape, such as may occur in nature with coral. The coral may be any suitable coral rock, including but not limited to BRS Pukani Dry Eco Aquarium Live Rock sold by Bulk Reef Supply, 672 Mendelssohn Avenue North, Golden Valley, Minn. 55427, pukani rock, or live rock. The coral 14 may have one or more holes 42 cut into the upper surface 22 . These holes 42 may be used to receive a plant plug 46 . In one embodiment the plant plugs 46 may be inserted into the hole 42 so that plant 46 generally grows out of the top upper surface 22 . In other embodiments, the plant 46 may grow out of any of the upper surface 22 , lower surface 26 , and three side surfaces 30 , 34 , 38 . One or more holes 50 are cut into the glass-side surface 18 . In each hole 50 is an attachment means 54 , which include but are not limited to threaded members, threaded screws, non-ferrous threaded members, non-ferrous screws. The attachment means 54 may be held in place in the hole 50 by a marine epoxy 66 or glue. A magnet 58 is attached to each attachment means 54 by mechanically screwing the attachment means 54 partially into magnet 58 , In this arrangement, the surface of the coral 14 does not touch the vivarium wall 70 , thus preventing scratching and other damage to the vivarium wall 70 . In addition there is gap 72 between the glass-side 18 of the coral and the inner side 74 of the wall. This gap 72 allows for circulation of water on all sides of the coral 14 , thereby allowing for natural growth conditions on and around the coral. In another embodiment, there is a marine glue 62 62 used to assist in attaching the magnet 58 to the glass side surface 18 . The marine glue 62 may be configured to adhere to rubber. A vivarium wall 70 is shown. The vivarium wall 70 will have an inner side 74 , that faces the interior of the vivarium, and an outer side 78 that faces outside of the vivarium. Another set of magnets 82 are configured to be magnetically attracted to magnets 58 . Thus, the coral 14 can be held against the vivarium wall 70 due to the magnetic forces of magnets 58 and 82 , and the coefficient of friction between the magnets 58 , 82 and the vivarium wall 70 . The magnets 58 , 82 may be any suitable magnet, and may include, but are not limited to, rubberized magnets, rubber coated magnets, plastic coated magnets, neodymium magnets coated in rubber or plastic. The rubber or plastic coating on the magnets will protect the vivarium walls from scratching and other damage. There may be multiple sets of magnets 58 , 82 along the length and or height of the coral 14 in order to provide more force to hold up the coral shelf.
[0015] FIG. 2 is a perspective view of a vivarium 86 . In this embodiment, two corals 14 are attached to the inner side 74 of a rear vivarium wall 70 . The magnets 82 located on the outer side 78 are partially visible. Depending on the size of the vivarium more or less than two corals may be attached to the rear vivarium wall 70 . In other embodiments, one or more corals configured either in shelf or flat wall shapes may be attached to the side and front walls of the vivarium.
[0016] FIG. 3 is side view of another embodiment of a vivarium wall device system 90 . A plastic glue disc 94 is attached to the glass-side surface 18 of the coral 14 using a suitable adhesive, such as, but not limited to a marine adhesive, or a marine silicone. Attached to the other side of the plastic glue disc 94 is an inside magnet 58 . The inside magnet 58 may be a marine waterproof coated magnet. In one embodiment, the magnet attaches to the disc 94 with a resin epoxy adhesive. One reason for using epoxy is that epoxy generally will not adhere to the rock and silicone generally will not adhere to the magnet properly. The disc 94 also provides a flat surface for both attachments. The disc 94 replaces the screw 54 in the embodiment shown in FIG. 1 , thus making for a simpler design. The inside magnet 58 may be attached to the plastic glue disc 94 via any suitable adhesive, including, but not limited to a marine adhesive. Attached to the other side of the inside magnet 58 (opposite the plastic glue disc side) is a plastic spacer 98 . The plastic spacer 98 is attached to the magnet 58 via any suitable adhesive, including but not limited to a marine adhesive or resin epoxy adhesive. The plastic spacers may allow for use of adhesives compatible with each respective surface. The plastic spacers protect the surface of the inner side 74 of the vivarium wall 70 and gives a generally calculable coefficient of surface friction between the spacer 98 and vivarium wall 70 . In this embodiment, there is no glue or adhesive between the plastic spacer 98 and the inner side 74 of the vivarium wall 70 . An outside magnet 82 is located near the outer side 78 of the vivarium wall 70 . The inner surface of the outside magnet 82 is attached to an outer plastic spacer 102 . The outside magnet 82 may be attached to the plastic spacer 102 via any suitable adhesive, including but not limited to a marine adhesive or resin epoxy adhesive. The outside magnet 82 is in magnetic attraction with the inside magnet 58 , and it is the magnetic attraction between the two magnets 58 , 82 and the coefficient of friction between the plastic spacers 98 , 102 and the vivarium wall 70 that generally hold the coral 14 in place relative to the wall 70 . In another embodiment, an adhesive may be used to attach the plastic spacers 98 , 102 to the vivarium wall 70 . The coral may vary from six inches in any direction to eighteen inches in any direction. The magnets 58 , 82 may, in one embodiment, be sized at about one inch square and about ⅛ th inch in thickness covered with a marine grade sealer paint or vinyl. There may be multiple sets of magnets 58 , 82 along the length and or height of the coral 14 in order to provide more force to hold up the coral shelf
[0017] FIG. 4 is a cross-sectional view of another embodiment 106 of the vivarium wall device system. In this embodiment, wood piece 110 is used as the element to hang on the vivarium wall 70 . The wood piece 110 may have a shelf-like shape, similar to the coral 14 , or as shown, be more decorative and without a shelf-like shape. The wood piece may be freshwater compatible or may be salt water compatible. The wood piece 110 may be custom cut, or may be simply found driftwood. Wood piece 110 may be selected from any suitable type of wood, including but not limited to Manzenita or Malaysian Driftwood. The wood piece 110 may vary from six inches in any direction to eighteen inches in any direction. A screw 114 within a hollow jacket 118 is used to attach the wood piece 110 to a magnet 58 . The screw 114 is screwed into the wood piece 110 until wood piece 110 is generally flush with the plastic jacket 118 . The screw 114 may be any suitable type of screw, including but not limited to a non-ferrous screw. The jacket 118 may be any suitable type of jacket, including but not limited to a round plastic jacket. The magnet 58 has a hole 60 that allows the screw 114 to slide through until the head 116 of the screw 114 (which is bigger than the hole) is stopped. The hole may unthreaded in one embodiment. In another embodiment, the hole may be threaded, and the screw is screwed into the hole in magnet. The hole 60 may be countersunk so that the screw head 116 is flush with the surface of the magnet 58 . The jacket 118 is slid onto the screw after the screw is attached to the magnet, then the screw is screwed into the wood piece 110 . Attached to the other side of the magnet 58 is a plastic spacer 98 . The plastic spacer 98 is attached to the magnet 58 via any suitable adhesive, including but not limited to a marine adhesive. An outside magnet 82 is located near the outer side 78 of the vivarium wall 70 . The inner surface of the outside magnet 82 is attached to an outer plastic spacer 102 . The outside magnet 82 may be attached to the plastic spacer 102 via any suitable adhesive, including but not limited to a marine adhesive. The outside magnet 82 is in magnetic attraction with the inside magnet 58 , and it is the magnetic attraction between the two magnets 58 , 82 and the coefficient of friction between the plastic spacers 98 , 102 and the vivarium wall 70 that generally hold the wood piece 110 in place relative to the wall 70 . There may be multiple sets of magnets 58 , 82 along the length and or height of the coral 14 in order to provide more force to hold up the wood piece 110 .
[0018] The disclosed device has many advantages. The disclosed vivarium wall attachable coral system will not scratch or damage the vivarium glass. The device provides natural support for industry live specimen “frag plugs” without use of artificial supports that cultivate unattractive algae, Growth attachment between the live specimen “frag” onto adjacent natural coral eliminates the need for relocation from unnatural support to natural support upon maturation. The device eliminates the risk of lime contamination from cement artificial rock. The use of rubber magnets protect the vivarium glass, and provide for additional friction to help maintain the positioning of the coral with respect to the vivarium wall. The coral is a natural material that does not look artificial. The Pukani coral is a “dead” coral when harvested and reduces environmental impact to the ocean environment normally associated with “live rock” harvesting. The disclosed system eliminates the need for vertical support, other than the magnets. The entire mounting system is marine compatible and will not deteriorate. Due to the strength of the magnets, and the rubber coated magnets, the coral will not slide down the vivarium wall. For vivarium wall 70 thicknesses above ⅜ of an inch, an additional magnet 82 may be magnetically attached to the surface of the inner magnet 58 for added pulling strength. Magnet 82 may have larger pulling strength than magnet 58 to reduce the size of magnet 58 for aesthetical reasons.
[0019] There may be water circulation all around the coral when the invention is used in an aquarium. The disclosed system is not limited to use with only aquariums, the system may also be used with terrariums and other types of vivariums.
[0020] It should be noted that the terms “first”, “second”, and “third”, and the like may be used herein to modify elements performing similar and/or analogous functions. These modifiers do not imply a spatial, sequential, or hierarchical order to the modified elements unless specifically stated.
[0021] While the disclosure has been described with reference to several embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the disclosure not be limited to the particular embodiments disclosed as the best mode contemplated for carrying out this disclosure, but that the disclosure will include all embodiments falling within the scope of the appended claims. | A vivarium wall device system comprising: a piece of coral or a piece of wood, the piece having a glass-side surface, upper surface, lower surface, and three side surfaces, and where the glass-side surface is generally flat and regular; a vivarium wall attachment means comprising: a first inside magnet, generally permanently attached to the glass-side surface; a first outside magnet, configured to be removeably and magnetically attachable to the first inside magnet; where when the first inside magnet is configured to be located inside the vivarium and magnetically attach to a first outside magnet located outside of the vivarium, and where the magnetic attraction occurs across a vivarium wall, and the coefficient of friction of the vivarium wall and the magnetic force tend to hold the piece of coral in place on the vivarium wall. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates generally to the chlorination of organic compounds and particularly to the catalytic chlorination of bromine-containing organic halides.
The conversion of bromine containing organic halides to other commerically useable forms by the replacement of at least one bromine atom with a chlorine atom is desirable in many instances. For example, in the preparation of the chain transfer agent bromotrichloromethane (CBrCl 3 ) by the direct bromination of chloroform, the overbromination of the chloroform can result in the production of undesirable quantities of dibromodichloromethane (CBr 2 Cl 2 ) and tribromochloromethane (CBr 3 Cl) as by-products. Preferably, these by-products are converted to the bromotrichloromethane product by a subsequent chlorination process. Similarly, the chlorination of 1,2-dibromoethane (CH 2 BrCH 2 Br) to form molecular bromine and a partially chlorinated haloalkane is quite common. The latter chlorination is generally catalyzed by the use of an iron halide or aluminum halide catalyst as described in U.S. Pat. Nos. 4,044,113 and 3,961,033. Such catalyzed processes are undesirable in many applications because of the incomplete displacement of bromide ions by chloride ions or because the molecular bromide and partially chlorinated products cannot be readily distilled from the catalyst.
It has now been found that organic halides containing at least one bromine atom can be chlorinated by a novel catalytic process.
SUMMARY OF THE INVENTION
The present invention is a process comprising reacting an organic halide containing at least one halogen-replaceable bromine atom with chlorine in the presence of a catalyst selected from the group consisting of the halides of antimony, tin, zinc, or vanadium to form a corresponding organic halide having at least the one bromine atom replaced by a chlorine atom.
Advantageously, the present catalytic process allows bromine and the organic halide reaction product to be formed at an acceptable rate and to be distilled directly from the reaction mixture without treating the catalyst with an acidified water wash. This feature allows the reaction to be conducted on a continuous or semi-continuous basis.
DETAILED DESCRIPTION OF THE INVENTION
Organic halides useful as reactants are compounds containing at least one chlorine-replaceable bromine atom. Illustrative of such compounds are: aliphatic halides containing from 1 to 6 carbon atoms; halocycloalkanes containing up to 6 carbon atoms; and aromatic halides. Organic halides containing more than the preferred number of carbon atoms can be used if desired. However, the rapid accumulation of tars in the reaction zone may result. Organic halides of bromine, and bromine and chlorine are the preferred reactants.
Illustrative of aliphatic haloalkanes useful in the present process are: dibromodichloromethane, 1,2,2-tribromo-2-chlorethane, 1,2-dibromoethane, 1-chloro-2-bromoethane, brominated pentanes, and brominated butanes. Aliphatic haloalkanes containing from 1 to 4 carbon atoms are especially suitable organic halides. When the recovery of bromine values from the organic halide is the primary objective of the process, the preferred haloalkane is 1,2-dibromoethane. When the preparation of bromotrichloromethane is the primary objective of the process, the preferred reactant is dibromodichloromethane, tribromochloromethane, or mixtures thereof.
Halocycloalkanes useful in the process include, for example, pentabromochlorocyclohexane and mono- or poly-halogenated cyclobutanes. Aromatic halides useful in the process are, for example, the mono- or polyhalogenated benzenes, toluenes, ethylbenzenes, dipropyl benzenes, diphenyls, and naphthalenes.
The catalyst employed is selected from the halides of antimony, tin, zinc, and vanadium. The chlorides, bromides, or chlorobromides of the metals can be used. However, the preferred catalyst is the metal chloride. Illustrative of such chlorides are antimony trichloride, antimony pentachloride, tin chloride, zinc chloride, vanadium chloride, and mixtures thereof. Antimony trichloride, and antimony pentachloride, and mixtures thereof are preferred.
A catalytic amount of the halide catalyst is employed. Generally, it is preferred to employ the least amount of the catalyst which allows the reaction to proceed at a commercially useable rate. Catalyst concentrations of from about 0.01 to about 12 percent by weight of the reactants have been found to be suitable. However, greater or lesser concentrations can be employed if desired. Catalyst concentrations of from about 3 to about 7 percent by weight of the reactants are preferred.
The temperature at which the catalytic reaction is conducted will vary with the boiling points of the products produced. However, the temperature employed should be sufficient to allow distillation of the desired products and bromine from the reaction mixture without causing undesirable amounts of reactant or product decomposition. In general, a reaction temperature within the range of from about 60° to about 120° C. has been found to be suitable. When 1,2-dibromoethane is the reactant, the reaction is conducted at a temperature of from about 60° to about 85° C. When dibromodichloromethane is the reactant, the reaction is conducted at a temperature of from about 105° to about 120° C. After initiation, the reaction is exothermic and cooling or heating means can be employed to keep the reaction within the desirable temperature range.
In practicing the process, chlorine gas is preferably added to a mixture of the solid catalyst contained in the liquid organic halide. Preferably, the chlorine is introduced into the reaction mixture at a rate sufficient to prevent the chlorine from bubbling out of the reaction mixture. The mole ratio of chlorine to organic halide depends upon the reactants, the desired product, and the reaction stoichiometry. Generally at least a stoichiometric amount, and preferably a thirty (30) to one hundred (100) percent excess, of chlorine is employed. Thus, the mole ratio of chlorine to organic halide is usually within the range of from 0.5/1.0 to 10/1 with a ratio of 1/1 to 5/1 being preferred.
The reaction proceeds well at atmospheric pressure. However, greater or lesser pressures can be used if desired.
The reaction products can be recovered from the reaction zone continuously by well-known techniques, especially by distillation.
While the present process is useful in preparing a number of organic halides, it is especially useful as a method of generating bromine. In this embodiment, 1,2-dibromoethane is reacted with chlorine in the presence of the catalyst (particularly antimony trichloride) to form a reaction product of bromine, and organic halides (i.e. 1,2-dichloroethane and 1-bromo-2-chloroethane). Because bromine is corrosive and requires special vessels and precautions during shipping, this process allows bromine to be recovered from 1,2-dibromoethane, a compound that is readily stored and shipped.
The invention is further illustrated by the following examples.
EXAMPLE 1
Dibromodichloromethane (4.3 moles, CBr 2 Cl 2 ) and 0.5 mole of antimony trichloride (SbCl 3 ) were placed in a one liter flask. The flask was equipped with a gas inlet for the introduction of chlorine and with a four bulb reflux condenser heated with atmospheric steam. The flask was heated to 110° C. and 2.2 moles of chlorine were then introduced into the mixture. The resulting reaction was exothermic. The reaction temperature was maintained within the range of 107° to 118° C. for about 1.5 hours. Bromine and low boiling organics were continuously distilled from the top of the condenser and condensed in an ice cooled trap. Fractionation of the recovered organic material yielded 8.4 mole percent carbon tetrachloride (CCl 4 ), 63.3 mole percent of trichlorobromomethane (CBrCl 3 ), and 22.6 mole percent dibromodichloromethane (CBr 2 Cl 2 ). The total recovery was 94.4 mole percent. Eighty-four percent of the bromine was recovered, excluding that which remained in the residual antimony salts.
EXAMPLE 2
Antimony trichloride (47 grams, 0.4 mole) and 4 moles of 1,2-dibromoethane (CH 2 BrCH 2 Br) were charged to a two liter, three-necked reactor flask equipped with a stirrer, a reflux condenser, and a gas inlet tube. Chlorine (4.08 moles) was then introduced into the reactor as rapidly as possible without allowing the chlorine to bubble out of the reaction mixture. The reaction mixture was maintained within a temperature range of from about 65° to about 75° C. When the reaction was no longer exothermic, a portion of the reaction mixture was neutralized with SO 2 and analyzed by gas-liquid chromatography using a 1/8 inch by 10 foot, 5% L.A.C., 2% H 3 PO 4 column. The analysis of organic material showed:
1,2-dichloroethane (CH 2 ClCH 2 Cl): 34.2 area %
1-chloro-2-bromoethane (CH 2 ClCH 2 Br): 64.1 area %
1,2-dibromoethane (CH 2 BrCH 2 Br): 1.7 area %
The reaction mixture was then heated to 65° to 75° C. and additional chlorine (2.17 moles) was introduced. Organic analysis following this addition showed:
1,2-dichloroethane: 75.0 area %
1-chloro-2-bromoethane: 22.3 area %
1,2-dibromoethane: 2.0 area %
Other: 0.7 area %
After standing about 48 hours, the reaction mixture was treated with water and SO 2 to destroy the bromine and SbCl 3 . The product was separated, washed with water, and dried with Na 2 SO 4 .
Analysis of recovered product showed: (387 g)
______________________________________ Area % % by wt Grams Moles______________________________________1,2-dichloroethane 82 75.74 293.1 2.961-chloro-2-bromoethane 16 20.83 80.6 0.581,2-dibromoethane 2 3.43 13.3 0.07TOTAL Organic Recovery 387.0 (90.25)______________________________________
The bromine recovery was not analyzed but appeared to be nearly quantitative.
EXAMPLE 3
A one liter, three-necked reactor flask equipped with a condenser, a thermometer, and glass inlet tube was charged with 1,2-dibromoethane (4.78 moles) and antimony trichloride (0.097 mole). The reactants were heated to about 80° C. Chlorine (6.05 moles) was added over a period of 12 hours. Bromine and low boiling organics were distilled from the top of the condenser as formed.
The distillate contained 74.5 percent by weight (479 g) bromine and 25.5 percent by weight (163 g) organics. The organic portion contained 30.1 percent by weight (49 g) 1,2-dichloroethane, 64.4 percent by weight (105 g) 1-chloro-2-bromoethane, and 5.5 percent by weight (90 g) of 1,2-dibromoethane.
The residue in the reactor contained 7 weight percent (31 g) bromine. The remaining 412 g in the reactor were:
______________________________________ % Grams by wt______________________________________1,2-dichloroethane 76.7 18.61-chloro-2-bromoethane 302.6 73.2Unknown 21.4 5.21,2-dibromoethane 12.3 3.0______________________________________
EXAMPLE 4
A twelve liter, three-necked reactor flask equipped with a gas inlet tube, stirrer, and reflux condenser was charged with 51.85 moles (17.940 g) of acetylene tetrabromide (CHBr 2 CHBr 2 ) and 2.0 moles (453 g) of antimony trichloride. The reactor was stirred and heated within the temperature range of from about 80° to about 100° C. Chlorine (67.6 moles, 2,400 g) was added slowly over a period of about 16 hours.
Upon distillation the organic reaction product contained the following:
______________________________________ Grams Moles Mole %______________________________________1-bromo-1,2,2-trichloroethane 64 0.3 0.6(CHBrClCHCl.sub.2)1,2-dibromo-1,2-dichloroethane 2,598 10.1 19.5(CHBrClCHBrCl)1,1,2-tribromo-2-chloroethane 7,028 23.3 45.0(CHBr.sub.2 CHBrCl)1,1,2,2-tetrabromoethane 6,235 18.0 37.7(CHBr.sub.2 CHBr.sub.2)TOTAL Recovery 51.7 99.8______________________________________ | Organic halides containing at least one halogen-replaceable bromine atom are reacted with chlorine in the presence of a catalyst selected from the group consisting of the halides of antimony, tin, zinc, or vanadium to form a corresponding organic halide having at least the one bromine atom replaced by a chlorine atom. | 2 |
RELATED APPLICATION
[0001] The present disclosure is related to commonly owned U.S. application Ser. No. ______, having the same filing date as the present application, titled, “Surgical Cutting Instrument with Near-Perimeter Interlocking Coupling Arrangement” (Atty Docket No. 31849.104/P31701), incorporated herein in its entirety by reference.
FIELD OF THE INVENTION
[0002] The present disclosure relates to a surgical cutting instrument, and more particularly, to a surgical cutting instrument with a dual surface interlocking coupling arrangement.
BACKGROUND
[0003] Bone-cutting surgical saws, such as sagittal or oscillating type surgical saws, cut most effectively at very high speeds, such as for example, 10000-40000 cycles per minute. These high speeds introduce high levels of vibration and can cause blade wander during a cut. Accordingly, actual blade cuts frequently have a thickness considerably greater than the thickness of the actual blade. For example, a cutting blade having a 0.015 inch thickness may be unable to cut a groove having a width of less than 0.030 inch.
[0004] Some vibration may be due to ineffective coupling systems. Coupling systems on conventional micro-saws clamp each side of the blade to rigidly secure the blade in place. Typical systems include protrusions on a bottom clamp that penetrate openings in the blade, and include an opposing top clamp that is smooth. Accordingly, only the bottom clamp holds the blade, while the top clamp is simply a smooth guide for blade placement. Over time, clamping forces may decrease, and because only one clamp secures the blade, the system becomes less stable, introducing additional vibration in the blade, and possibly resulting in less cutting effectiveness.
[0005] The devices disclosed herein overcome one or more of short-comings in the prior art.
SUMMARY
[0006] In one aspect, the present disclosure is directed to a hand-held surgical cutting instrument for cutting bone material with a surgical micro-saw blade having a plurality of openings formed therein. The surgical cutting instrument includes a hand-graspable body for manipulating the cutting instrument and a blade coupling mechanism attached to the body and is configured to attach to the surgical micro-saw blade. The blade coupling mechanism includes a first coupling member including a first blade-contacting surface. The first blade-contacting surface has at least one first protrusion extending therefrom and is configured to engage a first opening in the surgical saw blade. The blade coupling mechanism includes a second coupling member including a second blade-contacting surface facing the first blade-contacting surface of the first coupling member. The second blade-contacting surface has at least one second protrusion extending therefrom and is configured to engage a second opening in the surgical saw blade.
[0007] In another exemplary aspect, the present disclosure is directed to a hand-held surgical cutting system for cutting bone material. The system includes a surgical micro-saw blade having a distal end and a proximal end. The distal end has cutting teeth formed thereon and the proximal end has through-openings formed therein. The system also includes a surgical cutting saw including a hand-graspable body and a blade coupling mechanism attached to the body and configured to attach to the surgical micro-saw blade. The blade coupling mechanism includes a first coupling member including a first blade-contacting surface. The first blade-contacting surface has a first plurality of protrusions extending therefrom and is configured to engage openings in the surgical saw blade. The first plurality of protrusions are symmetrically disposed on the first blade-contacting surface. The blade coupling mechanism also includes a second coupling member including a second blade-contacting surface facing the first blade-contacting surface of the first coupling member. The second blade-contacting surface has a second plurality of protrusions extending therefrom and is configured to engage openings in the surgical saw blade. The second plurality of protrusions may be symmetrically disposed on the second blade-contacting surface and are offset from the first plurality of protrusions.
[0008] In yet another exemplary aspect, the present disclosure relates to a hand-held surgical cutting instrument for cutting bone tissue with a surgical micro-saw blade having openings formed therein. The surgical cutting instrument includes a hand-graspable body for manipulating the cutting instrument and a collet assembly attached to the body for attaching to the surgical micro-saw blade. The collet assembly includes a driving shaft including a head portion and a shaft portion. The head portion is removably connected to a first end of the shaft portion and includes a first blade-contacting surface facing the shaft portion. The blade-contacting surface has a first plurality of protrusions extending therefrom and is configured to engage the openings in the surgical saw blade. The collet assembly also includes a sleeve disposed about the driving shaft and is axially movable relative to the driving shaft. The sleeve includes a second blade-contacting surface facing the first blade-contacting surface. The second blade-contacting surface has a second plurality of protrusions extending therefrom and is configured to engage openings in the surgical saw blade. The first plurality of protrusions are offset from the second plurality of protrusions. At least one of the first and second blade-contacting surfaces includes a plurality of receiving recesses formed therein, the receiving recesses are sized and shaped to receive the respective protrusions of the other of the at least one of the first and second blade-contacting surfaces.
[0009] These and other features will become apparent from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is an illustration of an exemplary oscillating bone-cutting surgical system.
[0011] FIG. 2 is an illustration of a portion of an exemplary collet assembly from the surgical system of FIG. 1 with a micro-saw blade.
[0012] FIG. 3 is an illustration of a cross-section of the exemplary collet assembly of FIG. 2 with the micro-saw blade.
[0013] FIG. 4 is an illustration of the collet assembly of FIG. 2 with a driving shaft head removed to show a blade-contacting surface on a sleeve.
[0014] FIG. 5 is an illustration of an exemplary driving shaft head of the collet assembly of FIG. 2 , showing a blade-contacting surface.
[0015] FIG. 6 is an illustration of an exemplary driving shaft shank of the collet assembly of FIG. 2 .
[0016] FIG. 7 is an illustration of an exemplary micro-saw blade from the bone-cutting surgical system of FIG. 1 .
[0017] FIG. 8 is an illustration of an alternative embodiment of a driving shaft usable in an a collet assembly.
[0018] FIG. 9 is an illustration of an exemplary sagittal bone-cutting surgical system.
DETAILED DESCRIPTION
[0019] For the purposes of promoting an understanding of the principles of the invention, reference will now be made to embodiments or examples illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alteration and further modifications in the described embodiments, and any further applications of the principles of the invention as described herein are contemplated as would normally occur to one skilled in the art to which the disclosure relates.
[0020] Generally, the present disclosure relates to a bone cutting surgical system including a hand-held, high-speed, bone-cutting surgical saw, such as a sagittal or oscillating saw, and a cutting micro-saw blade. The saw includes a collet assembly with protrusions, such as pins or nubs, that mesh with or extend into openings on the cutting blade, thereby securing the blade in place in the collet assembly. In order to improve blade stability, the collet assembly disclosed herein includes protrusions that project into opening in the micro-saw blade from both the upper and lower sides. These offsetting protrusions may equalize the blade attachment, may reduce vibration, and may improve overall blade stability. In turn, this may improve cutting accuracy, which can reduce patient trauma and speed recovery time.
[0021] Turning now to FIG. 1 , the present disclosure is directed to a bone-cutting surgical system 100 including a surgical saw 102 and a selectively removable micro-saw blade 104 . The surgical saw 102 includes a hand-piece 106 , a cord 108 , and a connector 110 configured to removably couple with a power source. The connector 110 is merely exemplary, and it should be apparent to one skilled in the art that any suitable connector may be used, and in some embodiments, the cord 108 itself may be coupled to the power source without the use of a connector. Additional contemplated embodiments include a power source as a part of the hand-piece 106 , such as a battery powered hand-piece.
[0022] The hand-piece 106 includes a motor assembly 112 , a grip 114 , and a collet assembly 116 . In some embodiments, the motor assembly 112 is housed within the grip 114 , while in other embodiments, it is disposed adjacent to the grip 114 . It is contemplated that any suitable system for controlling the surgical saw 102 may be used. For example, some embodiments include a trigger system disposed on the hand-piece 106 to provide hand-control of the cutting speed, or alternatively, a foot pedal associated with the hand-piece 106 through the power source to provide the controlling inputs. Other control systems also are contemplated.
[0023] FIGS. 2 and 3 show a portion of the exemplary collet assembly 116 , and FIGS. 4-6 show collet assembly components. Referring to FIGS. 2 and 3 , the collet assembly 116 secures the saw blade 104 to the surgical saw 102 and transfers a driving force from the motor to the blade. In this embodiment, it includes a driving shaft 118 and a sleeve 120 defining a longitudinal collet axis 122 . The sleeve 120 receives and extends about the driving shaft 118 and is axially movable along the collet axis 122 relative to the driving shaft 118 , enabling selective coupling with the blade 104 . It is contemplated that any suitable material may be used for the collet assembly 116 . In one embodiment, a biocompatible stainless steel material, such as Stainless 17 - 4 is used.
[0024] Referring to FIGS. 3 and 4 , the sleeve 120 includes a head 124 and a shank 126 , with a central bore 128 extending therethough. In FIG. 4 , a portion of the driving shaft 118 is disposed within the bore 128 . The bore 128 permits the sleeve 120 to move axially along the driving shaft 118 , enabling selective locking and releasing of the blade 104 . The head 124 includes a substantially planar blade-contacting surface 130 and an outer perimeter 132 adjacent the blade-contacting surface 130 .
[0025] The blade-contacting surface 130 includes a plurality of protrusions 134 formed thereon. These are symmetrically disposed about the collet axis 122 and are configured to interface with the saw blade 104 . Here, the sleeve 120 includes four protrusions 134 extending therefrom, spaced apart about the collet axis 122 at 90 degree intervals. It is contemplated that more or fewer protrusions 134 may be present. The protrusions 134 may be integrally formed with sleeve 120 or, for manufacturing convenience, may be separate components fit, such as with an interference fit, into receiving ports (not shown) formed in the blade-contacting surface 130 . In this embodiment, the protrusions 134 are rectangular projections having a height equal to or greater than the thickness of a corresponding saw blade 104 . In other examples however, the protrusions 134 have a circular, triangular, or diamond-shaped cross-section. Protrusions of other shapes are also contemplated.
[0026] In addition to the protrusions, the blade-contacting surface 130 includes a plurality of receiving recesses 136 . In FIG. 4 , each of these are disposed between adjacent protrusions 134 , spaced symmetrically about the collet axis 122 . Like the protrusions 134 , the receiving recesses 136 are spaced 90 degrees apart. These have a depth less than the height of the adjacent protrusions, and as discussed below, are sized to receive protrusions on the driving shaft 118 .
[0027] The driving shaft 118 is shown in greater detail in FIGS. 3 , 5 , and 6 . Here, the driving shaft 118 includes a head 138 removably coupled to a distal end 139 of a shaft 140 . The shaft 140 defines a longitudinally extending shaft axis 142 ( FIG. 6 ).
[0028] Referring to FIGS. 3 and 5 the head 138 includes a blade-contacting surface 144 and an outer perimeter 146 . Here, the blade-contacting surface 144 includes a central recess 148 for connecting with the distal end 139 of the shaft 140 . In this embodiment, the central recess 148 is square shaped. The distal end 139 of the shaft 140 also is grooved to be square-shaped so that when the driving shaft 118 is assembled, the head 138 is unable to rotate relative to the shaft 140 . A through hole 150 in the central recess 148 receives a fastener, such as a screw 150 (shown in FIG. 2 ) that extends into a corresponding bore 152 in the end of the distal end 139 of the shaft 140 to fasten the head 138 to the shaft 140 .
[0029] The blade-contacting surface 138 also includes protrusions 154 formed thereon. Like those on the sleeve, these are symmetrically disposed about the collet axis 122 and are configured to interface with the saw blade 104 . Here, the head 138 includes four protrusions 154 extending therefrom, spaced apart at 90 degree intervals. It is contemplated that more or fewer protrusions 154 may be present. The protrusions 154 may be integrally formed with head 138 or may be separate components fit into receiving ports. Like those on the sleeve 120 , the protrusions 154 are rectangular projections having a height equal to or greater than the thickness of the corresponding saw blade 104 . Protrusions of other shapes are also contemplated. As discussed below, these protrusions are shaped and sized to fit into the receiving recess formed in the sleeve 120 .
[0030] The shaft 140 includes the distal end 139 either connected to or integral with the head 138 and includes a proximal end 156 . In this embodiment, the proximal end 156 includes a motor coupling feature 158 shown as a pin-receiving through passage that connects either directly or cooperatively to the motor to provide the cutting oscillation required.
[0031] Referring now to FIG. 3 , as can be seen, the sleeve blade-contacting surface 130 and the driving shaft blade-contacting surface 144 face each other. The outer perimeter 146 of the head 138 is sized to have substantially the same diameter as the sleeve outer perimeter 132 . The sleeve 120 and driving shaft 118 may axially move apart to receive the blade 104 , and then come together to clamp the blade 104 between the blade-contacting surfaces 130 , 144 . Although not shown, a spring force may be used to bias the sleeve 120 into a clamped position to secure any blade in place.
[0032] FIG. 7 shows the exemplary micro-saw blade 104 usable with the surgical saw 102 in FIG. 1 and securable with the collet assembly 116 in FIGS. 2-6 . The micro-saw blade 104 may be stamped and/or machined form a single material having a thickness in the range of 0.007-0.022 inch, for example. It includes a proximal end 180 that facilitates interconnection with the collet assembly 116 and a distal end 182 having a cutting edge including a plurality of cutting teeth 184 formed thereon.
[0033] In this example, the proximal end 180 is defined by a relatively bulbous head 186 that includes a slot 188 extending inwardly along a longitudinal axis 190 from the proximal end of the saw blade 104 . The slot 188 is formed with a funnel-like opening 192 defined by substantially straight edges 194 facing toward the longitudinal axis 190 . The straight edges 194 may help guide the saw blade 104 into place on the collet assembly 116 . A partially circular outer perimeter 196 defines an outer edge of the bulbous head 186 . In some embodiments, the outer perimeter 196 has a diameter substantially the same as, or slightly smaller than, the diameter of the driving shaft head 138 and the sleeve head 124 .
[0034] Openings 198 formed in the proximal end 180 permit the saw blade 104 to be secured to the surgical saw collet assembly 116 . In the embodiment shown, the openings 198 are symmetrically disposed about a center point 200 . Here, at least two openings 198 lie directly on opposing sides of the center point 200 and on transverse sides of the longitudinal axis 190 . A centrally disposed opening 198 lies along the longitudinal axis 190 . In the example shown the openings 198 are offset from each other by 45 degrees and are sized to match the protrusions 134 , 154 on the driving shaft 118 and sleeve 120 . However, other offset angles are contemplated that match the desired collet assembly.
[0035] Here, each opening 198 is rectangular shaped in order to match the shape of the protrusions of the collet assembly 116 . In the example shown, the bulbous head 186 includes five openings 204 , 206 . However, in other embodiments, more or less openings may be provided. When the funnel-like opening 192 has an angle smaller than that shown, additional openings may be included, while maintaining the 45 degree spacing shown.
[0036] Returning to FIG. 3 , the collet protrusions interconnect with the saw blade 104 to secure it in place. The sleeve protrusions 134 extend upwardly in FIG. 3 , through the openings 198 and abut against the blade-contacting surface 144 . Likewise, although not visible in FIG. 3 , the driving shaft protrusions 154 extend downwardly through the openings 198 and into the receiving recesses 136 in the sleeve 120 . Accordingly, in the saw blade embodiment having five openings 198 as in FIG. 7 , either two or three protrusions pass through the blade openings 198 from the bottom and either two or three protrusions pass through the blade openings 198 from the top. Because the sleeve protrusions 134 are spaced 90 degrees apart and the driving shaft protrusions 154 are spaced 90 degrees apart, but offset from the sleeve protrusions by 45 degrees, the blade 104 can be removed and secured in the collet assembly in eight different positions. In some embodiments, for example, the collet assembly includes a total of only four protrusions or six protrusions, and the openings on the blade 104 are chosen to correspond with the protrusions. Other amounts of protrusions are contemplated.
[0037] In addition to securing the saw blade 104 in place with the protrusions 134 , 154 , the blade-contacting surfaces 130 , 134 also frictionally engage and reduce vibration and play. Accordingly, it may be beneficial to provide as much contact area between the blade and blade-contacting surfaces as is practicable. Accordingly, in the embodiment shown, the protrusions 134 , 154 are formed with rectangular cross-sections instead of circular cross-sections. Rectangular shaped protrusions can have the same maximum width as a corresponding cylindrical protrusions for stability, but permits an overall increase in the blade surface area that interfaces with the blade-contacting surfaces 130 , 144 . This too may help more solidly secure the blade 104 in place in the collet assembly 116 .
[0038] FIG. 8 shows an alternative driving shaft 250 . Here the driving shaft includes the shaft 140 , but includes an alternative head 252 . Because many of the features of the head 252 are similar to those discussed above, only the differences will be discussed in detail. Here, in addition to having rectangular protrusions 254 , the head 252 includes a plurality of receiving recesses 256 . Each of these are disposed between the adjacent protrusions 254 , and spaced symmetrically about a driving shaft axis 258 . The protrusions 254 are spaced 90 degrees apart, and the receiving recesses are spaced 90 degrees apart. These receiving recesses 256 are shaped differently than the corresponding protrusions on the sleeve 120 however. These receiving recesses 256 are shaped with a curved inner end and parallel sides that extend entirely to an outer perimeter 260 . Accordingly, in use with this embodiment, the sleeve protrusions 134 may extend entirely through the blade openings 198 , but instead of abutting directly against the blade-contacting surface of the driving shaft, the sleeve protrusions project into the receiving recesses 256 .
[0039] It should be noted that in some embodiments, the receiving recesses on the head may be shaped and sized similar to those described relative to the sleeve 120 , but that any suitable size and shape may be used.
[0040] FIG. 9 shows a sagittal saw 300 for driving the saw blade 104 . In this embodiment, a collet assembly 302 is arranged to secure the blade 104 in an axial direction relative to a saw handle 304 . Accordingly, in this embodiment, the collet assembly 302 includes side-by-side blade-contacting surfaces. However, like the oscillating saw 102 disclosed in FIGS. 1-6 , the sagittal saw 300 includes protrusions disposed on both blade-contacting surfaces adjacent an exterior edge of the collet fixture, and the blade 104 is sized so that the outer perimeter of the head of the saw blade substantially corresponds to the edge of the collet assembly.
[0041] Although only a few exemplary embodiments 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 disclosure. Accordingly, all such modifications and alternatives are intended to be included within the scope of the invention as defined in the following claims. Those skilled in the art should also realize that such modifications and equivalent constructions or methods do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure. | A hand-held surgical cutting instrument for cutting bone material with a surgical micro-saw blade has a plurality of openings formed therein. The surgical cutting instrument includes a hand-graspable body for manipulating the cutting instrument and a blade coupling mechanism attached to the body and being configured to attach to the surgical micro-saw blade. The blade coupling mechanism includes a first coupling member including a first blade-contacting surface. The first blade-contacting surface has at least one first protrusion extending therefrom and is configured to engage a first opening in the surgical saw blade. The blade coupling mechanism includes a second coupling member including a second blade-contacting surface facing the first blade-contacting surface of the first coupling member. The second blade-contacting surface having at least one second protrusion extending therefrom and configured to engage a second opening in the surgical saw blade. | 0 |
BACKGROUND OF THE INVENTION
This invention relates generally to steam turbine buckets (or blades) and, more particularly, to the adhesion of filler material in hybrid or composite blades.
Steam turbine blades operate in an environment where they are subject to high centrifugal loads and vibratory stresses. Vibratory stresses increase when blade natural frequencies become in resonance. The magnitude of vibratory stresses when a blade vibrates in resonance is proportional to the amount of damping present in the system (damping to a smaller or greater degree is achieved via materials and the aerodynamic and mechanical components), as well as the vibration stimulus level.
At the same time, centrifugal loads are a function of the operating speed, the mass of the blade, and the radius from engine centerline where that mass is located. As the mass of the blade increases, the physical area or cross-sectional area must increase at lower radial heights to be able to carry the mass above it without exceeding the allowable stresses for the given material. This increasing section area of the blade at lower spans contributes to excessive flow blockage at the root and thus lower performance. The weight of the blade also contributes to higher disk stresses and thus potentially to reduced reliability.
Several prior U.S. patents relate to so-called “hybrid” blade designs where the airfoil portion of the metal blade is formed with one or more pockets filled with a polymer (or polymer/metal, glass or ceramics mix) filler material. These prior patents include U.S. Pat. Nos. 6,287,080; 6,139,278; 6,042,338; 6,039,542; 6,033,186; 5,947,688; 5,931,641 and 5,720,597. See also co-pending commonly owned application Ser. No. 10/249,518, filed Apr. 16, 2003. One area not addressed by the prior work in this area is the problem of achieving more reliable adhesion of the filler within the pocket or pockets formed in the airfoil portion of the blade.
More specifically, the large incidence angles of steam flow to the bucket surface could cause the cast polymer filler to delaminate from the pocket formed in the airfoil portion of the blade. In other words, the large angle of incidence of the steam flow to the bucket surface exposes a higher risk of the flow tending to “lift” the filler material off the pocketed surface.
BRIEF DESCRIPTION OF THE INVENTION
This invention proposes an edge geometry along one or more edges of the pocket formed in the airfoil portion of the blade in order to improve adhesion of the filler at the interface, specifically in the high angle of incidence steam flow field. While this invention utilizes the hybrid blade concept as disclosed, for example, in U.S. Pat. No. 5,931,641, that concept is extended to include optimization of pocket shape within the airfoil portions of the blades in order to improve adhesion of the filler material.
In the exemplary embodiment, the marginal area of the pocket, and preferably the marginal edge of the pocket extending along the leading edge of the blade, is formed with an “undercut.” This undercut serves the purpose of not allowing the high angle of incidence steam flow from trying to “lift” the polymer (or polymer/metal mix) filler from the pocket. The undercut thus shields that portion of the filler/bucket interface with the highest angle of incidence to the incoming steam flow. The undercut could also be extended, however, to include the trailing edge or even all edges of the pocket or pockets.
Accordingly, in its broader aspects, the invention relates to a steam turbine rotor wheel comprising a plurality of blades secured about a circumferential periphery of the wheel, each blade comprising a shank portion and an airfoil portion, the airfoil portion having at least one pocket filled with a filler material, wherein at least one edge of the pocket adjacent a leading edge of the blade is formed with an undercut.
In another aspect, the invention relates to a steam turbine rotor wheel comprising a row of blades secured about a circumferential periphery of the wheel, each blade formed with one or more pockets filled with a filler material and where at least an edge of the pocket adjacent a leading edge of the airfoil incorporates means for enhancing adhesion of the filler material to the blade.
In still another aspect, the present invention relates to a turbine blade comprising a shank portion and an airfoil portion, the airfoil portion having at least one pocket filled with a filler material, wherein at least one edge of the pocket adjacent a leading edge of the blade is formed with an undercut.
The invention will now be described in detail in connection with the drawings identified below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a partially manufactured blade illustrating an unfilled pocket configuration in the airfoil portion of the blade;
FIG. 2 is a similar view of the blade in FIG. 1 but after filler material has been applied over the pockets;
FIG. 3 is a partial plan view of another hybrid blade illustrating multiple filled pockets along the airfoil portion of the blade;
FIG. 4 is a cross-sectional view of the blade shown in FIG. 3 ;
FIG. 5 is an elevation of a hybrid blade constructed in accordance with the exemplary embodiment of this invention;
FIG. 6 is a section taken along the line 6 — 6 in FIG. 5 ;
FIG. 7 is an enlarged detail taken from FIG. 6 ;
FIG. 8 is a partial cross-section of the trailing edge of a hybrid blade with an undercut similar to that shown in FIG. 7 ; and
FIG. 9 is a section taken along the line 9 — 9 of FIG. 5 , illustrating undercuts on the radially inner and outer edges of the airfoil filler pocket.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1 , a steam turbine blade 10 is shown in partially manufactured form. The blade 10 includes a shank portion 12 and an airfoil portion 14 . The airfoil portion is preferably constructed of steel or titanium but other suitable materials include aluminum, cobalt or nickel. Ribs 16 , 18 are integrally cast with the airfoil portion to form discrete pockets 20 , 22 and 24 . It will be appreciated, however, that the ribs do not extend flush with the side edges 26 , 28 of the airfoil portion. The rib height may in fact vary according to specific applications. A polymer based (or polymer/metal, glass or ceramics mix) filler material 30 as described, for example, in U.S. Pat. Nos. 6,287,080 and 5,931,641 is cast-in-place over the pressure side of the airfoil, filling the pockets 20 , 22 and 24 and covering the ribs to thereby form a smooth face 32 on the pressure side of the bucket, as shown in FIG. 2 .
FIGS. 3 and 4 illustrate another known hybrid blade construction where the blade 34 is formed with a plurality of discrete pockets 36 , 38 , 40 , etc. along the pressure side of the airfoil portion 42 of the blade. In this arrangement, filler material 44 ( FIG. 4 ) is cast in each pocket individually, with the filler material flush with the surrounding airfoil surfaces. As a result, each discrete pocket is externally visible. FIG. 4 also illustrates the conventional practice of forming the pockets 46 , 48 with side surfaces 50 , 52 and 54 , 56 that curve radially outwardly (at an oblique angle to the adjacent airfoil surface) at the interface with the exterior surface of the airfoil portion.
Currently, available choices for bonding the filler material 30 or 44 to the metal surface of the airfoil portion include, without limitation, self adhesion, adhesion between the filler material 30 or 44 and the metal surface of the airfoil portion, adhesive bonding (adhesive film or paste), and fusion bonding. As discussed above, however, these adhesion techniques may not be sufficient to prevent delamination of the filler along that part of the filler-blade interface exposed to large angle of incidence steam flow. In accordance with an exemplary embodiment of this invention, and with reference to FIGS. 5 and 6 , adhesion of the filler is enhanced by the incorporation of an undercut along some or all of the edges of the pocket. Referring initially to FIG. 5 , the blade 58 is formed with three polymer-filled pockets 60 , 62 and 64 on the pressure side 66 of the airfoil portion of the blade. Filler material 68 is shown cast-in-place, with the filler material flush with the surrounding airfoil surface. As shown in FIG. 6 , the pocket 64 is defined by an edge 70 closest to the trailing edge 72 of the bucket that smoothly interfaces with the external surface of the airfoil, in accordance with the prior practice. The pocket edge 74 closest to the leading edge 76 , however, is now formed with an undercut 78 that creates an acute angle α at the interface with the adjacent airfoil surface, as best seen in FIG. 7 . The undercut itself may be formed of a small or large radius R depending upon the thickness of the airfoil near the leading edge, and the radius is gradually blended into the back wall 80 of the pocket in such a way as to reduce the concentrated stress due to the undercut geometry. It will be understood that the manner of application as well as the composition of the filler material may be in accordance with current practice.
It will also be appreciated that the overall configuration of the pocket may vary as desired, and that the invention here relates primarily to the incorporation of an undercut along the marginal edges of the one or more pockets, and especially along the edge closest to (or adjacent to) the leading edge of the bucket where the filler material interfaces with the adjacent external surface on the pressure side of the bucket. The undercut could, however, be extended to include the pocket edge closest to (or adjacent to) the trailing edge of the bucket (see undercut 80 in FIG. 8 ), or even to include all edges of the one or more pockets (see undercut 82 in FIG. 9 which extends about the entire periphery of the pocket). As described above, the incorporation of an undercut prevents the steam flow from causing delamination of the pocket fill material at the most vulnerable location, i.e., along the leading edge of the airfoil.
While the 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 to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. | A steam turbine rotor wheel includes a plurality of blades secured about a circumferential periphery of the wheel, each blade comprising a shank portion and an airfoil portion, the airfoil portion having at least one pocket filled with a filler material, wherein at least one edge of the pocket adjacent a leading edge of the blade is formed with an undercut. | 5 |
FIELD OF THE INVENTION
[0001] The present invention generally relates to a system that stops a vehicle door as it opens to prevent contact of the vehicle door with a nearby object.
BACKGROUND OF THE INVENTION
[0002] Vehicle doors typically include one or more detent points within their swing arc to hold the door at a fixed point short of fully open to help prevent door contact with adjacent objects. The detent point is typically a compromise between providing sufficient room for driver ingress/egress and door protection. Typically, a single detent cannot account for all door swing/opening scenarios.
[0003] Various infinite/variable door check or stop systems have been developed for the motor vehicle market. These systems may be designed to hold the door in position at whatever point door movement stops in the swing arc. In this manner a door can be opened as near to an adjacent object as desired, and the door check will hold it in position until the user applies a “overcoming” force to move the door out of that detent position. However, such systems suffer from various drawbacks.
[0004] Automatic door check systems that attempt to arrest door movement prior to contacting an adjacent object have also been developed. Such systems typically utilize one or more sensors (e.g. ultrasonic) mounted in the door to detect distance to adjacent objects and automatically stop door movement before contact. However, such systems may be costly, and the positioning of the sensor(s) may negatively affect the appearance of the vehicle door.
SUMMARY OF THE INVENTION
[0005] One aspect of the present invention is a system for controlling movement of a vehicle door relative to a primary vehicle structure. The system includes at least one ultrasonic sensor configured to detect a distance from a vehicle primary structure to an object in the vicinity of the vehicle. The ultrasonic sensor also provides input to a vehicle automatic parallel parking system. The system preferably includes at least two ultrasonic sensors configured to detect the distances to objects on opposite sides of a vehicle. The system utilizes a plurality of detected distances to a detected object taken at different times, and a plurality of vehicle positions or velocities at different times before a vehicle stops, and which correspond to the times at which the detected distances are taken. The system determines a location of the detected object relative to the vehicle primary structure, and the system selectively actuates the door brake to prevent the vehicle door from contacting the detected object as the door is opened. The system may also utilize vehicle yaw rate in addition to the vehicle velocity (or distance/odometer reading), and record the information at each buffer point of a rolling buffer. This data can be used to create a two dimensional mapping of objects next to the vehicle. The vehicle geometry and door swing path information can be utilized to selectively actuate the door brake.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] In the drawings:
[0007] FIG. 1 is a partially schematic plan view of a motor vehicle including a door control system according to one aspect of the present invention;
[0008] FIG. 2 is a schematic view of object mapping conducted utilizing data from an ultrasonic sensor;
[0009] FIG. 3 shows the door swing path intersection to an adjacent object; and
[0010] FIG. 4 is a flow chart of data flow for automatic door check operation according to one aspect of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as oriented in FIG. 1 . However, it is to be understood that the invention may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawing, and described in the following specifications are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.
[0012] With reference to FIG. 1 , a motor vehicle 1 includes a primary vehicle structure 2 , and front doors 3 A and 3 B, and rear doors 4 A and 4 B. Front door 3 A is pivotally mounted to primary vehicle structure 2 for rotation about a generally vertical axis 5 .
[0013] The vehicle 1 may include a door brake 8 comprising a powered actuator (not shown) that can be actuated by a vehicle controller 9 to stop movement of door 3 A relative to primary vehicle structure 2 . Vehicle 1 may also include a door position sensor 7 that senses an angle of the door 3 A. Sensor 7 may comprise part of the door brake 8 , or it may comprise a separately-positioned component. The door angle sensor 7 provides information to controller 9 concerning the angular position of door 3 A relative to primary vehicle structure 2 . The door brake 8 may comprise a known door brake or check actuator, and the details of door brake 8 will not therefore be described in detail herein. Doors 3 B, 4 A, and 4 B may also include door angle sensor 7 and door brakes 8 .
[0014] Motor vehicle 1 may also include one or more ultrasonic sensors 10 A and 10 B positioned in front quarter panels 11 A and 11 B, respectively, or other suitable location. Signals 12 A and 12 B from ultrasonic sensors 10 A and 10 B can be utilized to determine a location of an object relative to the primary vehicle structure 2 . Sensors 10 A and 10 B may provide input to an automatic system for parallel parking (not shown) of motor vehicle 1 . Automatic systems for parallel parking may include actuators that steer the front wheels, and control forward and rearward motion of a motor vehicle. Such systems are known, and the details of the automatic parallel parking system of vehicle 1 will not therefore be described in detail herein. The sensors 10 A and 10 B typically point to the side of the vehicle, and provide parking space and distance measurements among other functions. Since the sensors provide distance-to-object information, the sensors can be utilized to provide maximum door swing distance to an adjacent object for an automatic doorstop function.
[0015] The door swing limiting function can be performed using a rolling buffer of latitudinal distance to an adjacent object versus distance traveled over time where the buffer contains only the last amount of configurable distance traveled (for example 2 to 3 meters). The latitudinal information as determined from the side sensor 10 A (or 10 B) along with the vehicle velocity as determined by a velocity sensor 13 and vehicle yaw rate that may also be determined by sensor 13 or other sensor recorded at each buffer point can be used to create a two dimensional mapping of objects next to the vehicle. As shown in FIG. 5 , object mapping using sensor 10 A may be determined as follows:
[0016] Origin ( 0 , 0 ) Final stopping point of the side ultrasonic sensor
[0017] p Yaw rate in radians per second at time interval t i
[0018] v Vehicle velocity in meters per second at time interval t i
[0019] t Interval time period. It is assumed that all interval time periods are equal (t 0 )
[0020] u Ultrasonic measured distance to object at time interval t i
[0021] θ Resultant angle traveled as a result of the yaw rate over the time interval t i
[0022] i Interval count
[0023] x,y Cartisian coordinates of the ultrasonic sensor relative to the final stopping point at time interval t i
[0024] d Final distance of vehicle to object based on ultrasonic measured distance across longitudinal distance y i
[0025] The overall angle, θ, is the summation of each angle θ i , where θ i =p i t i,
[0026] Assume t i =t 0 where t 0 is a constant value.
[0000] y 0 =a 0 =c 0 =v 0 t 0
[0000] x 0 =b 0 =0
[0000] c 0 =v 0 t 0
[0000]
d
0
=u
0
−x
0
=u
0
[0000] a 1 =c 1 cos θ 0 =v 1 t 1 cos ( p 0 t 0 )
[0000] b 1 =c 1 sin θ 0 =v 1 t 1 sin ( p 0 t 0 )
[0000] c 1 =v 1 t 1
[0000] x 1 =b 0 +b 1 =0 +v 1 t 1 sin ( p 0 t 0 )
[0000] y 1 =a 0 +a 1 =v 0 t 0 +v 1 t 1 sin ( p 0 t 0 )
[0000] d 1 =u 1 −x 1 =u 1 −v 1 t 1 sin ( p 0 t 0 )
[0000] a 2 =c 2 cos (θ 0 +θ 1 )= v 2 t 2 cos ( p 0 t 0 +p 1 t 1 )
[0000] b 2 =c 2 sin (θ 0 +θ 1 )= v 2 t 2 sin ( p 0 t 0 +p 1 t 1 )
[0000] c 2 =v 2 t 2
[0000] x 2 =b 0 +b 1 +b 2 =v 1 t 1 sin ( p 0 t 0 )+ v 2 t 2 cos ( p 0 t 0 +p 1 t 1 )
[0000] y 2 =a 0 +a 1 +a 2 =v 0 t 0 +v 1 t 1 sin ( p 0 t 0 )+ v 2 t 2 sin ( p 0 t 0 +p 1 t 1 )
[0000] d 2 =u 2 −x 2 =u 2 −[v 1 t 1 sin ( p 0 t 0 )+ v 2 t 2 cos ( p 0 t 0 +p 1 t 1 )]
[0000] . . .
[0000] a i −c i cos (Σ 0→i θ n )= v i t i cos ( t 0 Σ 0→i−1 p n ) where t i =t 0
[0000] b i =c i sin (Σ 0→i θ n )= v i t i sin ( t 0 Σ 0→i−1 p n ) where t i =t 0
[0000] c i =v i t i
[0000] x i =Σ 0→i b n =v 1 t 1 sin ( p 0 t 0 )+ v 2 t 2 cos ( t 0 Σ 0→1 p n )+ . . . + v i t i cos ( t 0 Σ 0→i−1 p n )
[0000] y i =Σ 0→i a n =v 0 t 0 +v 1 t 1 sin ( p 0 t 0 )+ v 2 t 2 sin ( t 0 Σ 0→1 p n )+ . . . + v i t i sin ( t 0 Σ 0→i−1 p n )
[0000] d i =u i −x i =u i −[v 0 t 0 +v 1 t 1 sin ( p 0 t 0 )+ v 2 t 2 sin ( t 0 Σ 0→1 p n )+ . . . + v i t i sin ( t 0 Σ 0→i−1 p n )]
[0027] With further reference to FIG. 3 , knowing the system host vehicle geometry, it only remains to determine if the door swing path will intersect with any adjacent objects and at what arc point this will occur. Determining the door angle position (Θ door ) such as with a hall-effect sensor or other method, it can ascertained when the door 3 A is approaching an adjacent object 15 (y door =d buffer ) and activate an electric door brake 8 , or other method, to halt movement of door 3 A.
[0028] In FIG. 3 , P 1 represents the door pivot point, and the curved line P 2 represents the door swing path. The variables shown in FIG. 3 are defined as follows:
[0029] x sensor =Distance in x direction from sensor to the door pivot point
[0030] x door =Distance in x direction of door tip travel
[0031] y door =Distance in y direction of door tip travel
[0032] θ door =Angular position of door
[0033] r door =Door width
[0034] d buffer =Distance to adjacent object at (x sensor +x door ) position as stored in the buffer.
[0035] Door swing limit is at the point where door tip travel in the y direction (y door ) is equal to the distance to the adjacent object (d buffer ) at (x sensor +x door ) as stored in the buffer.
[0000] Y door =d buffer at ( x sensor +x door )
[0000] where
[0000] x door =r door sin θ door
[0000] and
[0000] y door =r door cos θ door
[0036] An example of potential data flow for automatic door check operation according to one aspect of the present invention is shown in FIG. 4 . The door brake is initiated at the block 20 of FIG. 4 . The controller 9 first determines if the vehicle is in motion as designated 22 in FIG. 4 . If the vehicle is in motion, the adjacent object buffer is populated at 24 , and the controller again determines if the vehicle is in motion. If the controller determines that the vehicle is not in motion, the controller then determines if the vehicle is in park at 26 . If not, the controller then again determines if the vehicle is in motion at 22 . However, if the vehicle is in park, the controller then determines if the door is open at 28 . If the door is not open, the door brake sequence ends. If the door is open, the controller then determines if the door position is within the bounds of the buffered values at 30 . If not, the door brake is actuated or applied at 32 . However, if the door position is within the bounds of the buffered values, the door brake is released (or allowed to remain released) at 34 .
[0037] It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise. | A system for controlling movement of a motor vehicle door includes at least one sensor that detects a distance from the vehicle to an object near the vehicle. The sensor is also configured to provide input to an automatic parallel parking system of the vehicle. The system may include at least one ultrasonic sensor on each side of the vehicle to detect the distances to objects on opposite sides of a vehicle. The system utilizes a plurality of detected distances and vehicle positions or velocities to determine a location of the detected object relative to the vehicle. The system selectively actuates the door brake to prevent the vehicle door from contacting the detected object as the door is opened. | 4 |
This invention is concerned with an English/metric indicator unit which can be used to adapt a machine tool constructed normally to operate in English (i.c. inch) units of measurement, so as to permit its operation in metric units, or vice versa.
It will be appreciated that a conventional movement indicator device in a machine tool which is constructed normally to operate in, say, English units of measurement, is calibrated in inches. To enable the machine to be operated in metric units, each metric dimension (e.g. on a drawing) must first be converted by the operative into inches before he can operate the machine. For example, if to perform a particular operation on a lathe, the lead screw is required to move the tool carriage through 10mm, the operative must first convert this into 0.3937 in.; he can then turn the lead screw to effect this movement as shown on the lead screw indicator.
BRIEF SUMMARY OF THE INVENTION.
The object of the invention is to provide, for application to a lead or other rotary control member in a machine tool, an indicator unit which, in the case of a tool constructed to operate in English units of measurement, enables an operative to read directly in metric units, the amount of axial displacement produced by the member as it turns, or vice versa. It will be appreciated that this facility is becoming increasingly important at the present time as metric units of measurement become more and more widely used in engineering.
According to the invention there is provided, for a machine tool, an English/metric indicator unit comprising an externally-toothed gear wheel which can be fitted to a rotary control member (e.g. a screw) in a machine tool so as to turn with the member about its rotational axis; a rotatable internally-toothed annular member arranged in mesh said gear wheel with its axis of rotation eccentric to the axis of rotation of the latter, the number of teeth on the gear wheel and on the annular member being chosen to provide the appropriate English/metric conversion ratio between these two components; and a graduated scale on the annular member to indicate, with reference to a datum, the converted reading upon rotation of said rotary control member.
When fitted to the lead screw of a lathe, for example, rotation of the lead screw will turn said gear wheel to drive the annular member at a slower speed. Where the lathe is, say, constructed to normally operate in English units of measurement, the scale on the annular member will be graduated in metric units and the conversion ratio will be chosen so that the displacement of the tool carriage produced by turning the lead screw is automatically indicated in metric units on the said scale.
An operative can therefore operate the lathe directly in metric units.
GENERAL DESCRIPTION.
It will be realized from the foregoing that the indicator unit provided by the invention is of relatively simple construction for ease of manufacture and fitting to the machine tool in question, and for minimim cost. Moreover, this simplicity in construction enables the most convenient gear ratios to be chosen for maximum accuracy in conversion. For example, an English to metric gear ratio of 140:127 has been found particularly suitable, where the pitch of the lead screw of a machine tool is measured in multiples of 1/8 inch.
Also a range of sizes may be developed to cover machine tools from the smallest lathe to the largest milling machine.
Although the indicator unit provided by the invention may display only the converted reading, it is preferably arranged to display the reading in both metric and English units. The machine tool can then be operated in either set of units. To achieve this, the gear wheel of the unit may be arranged to drive a disc-form dial member which is marked around its periphery with graduations in the same units as those in which the machine tool is constructed for normal operation. This further member is conveniently positioned along-side the said annular member so that the reading is displayed side by side in both English and metric units. An indicator plate (see below) may be provided to mask the scale not being used at any time.
The construction of the indicator unit will be basically the same whether for use on a machine tool which normally operates in metric or English units. Such differences as there are will be in the gear ratio between the gear wheel and annular member and in dimensions.
BRIEF DESCRIPTION OF DRAWINGS
To facilitate understanding of the invention, and to enable it to be readily carried into practice, reference will now be made to the accompanying drawings which, illustrate an embodiment of a conversion indicator constructed in accordance with the invention. In the drawings:-
FIG. 1 is a elevational view of a conversion indicator unit constructed in accordance with the invention, for converting English measurements into their metric equivalent;
FIG. 2 is a diametral section of FIG. 1; and
FIG. 3 is a fragementary perspective with parts broken away showing an alternative form of drive suitable for the unit of FIGS. 1 and 2.
DETAILED DESCRIPTION
The drawings show an indicator unit for fitment, for example to the lead screw spindle 1 of a lathe. This particular indicator is used on a screw having English threads and is arranged to display in inches, the amount by which the tool carriage moves when the spindle is turned by an operative, and also to convert this measurement into a metric figure.
The unit itself comprises a circular base plate 2 which in use is mounted by bolts (not shown) on an appropriate part 4 of the machine tool through which the spindle 1 extends. An eccentric aperture 5 is formed in the base plate to receive a bush 6 mounted on spindle 1 and secured thereto by a setscrew (not shown). It will be noted that bush 6 has an enlarged outer end 6a.
The base plate 2 has a peripheral flange 7 which is used to locate (by engagement in a complementary rebate) a free internally-toothed ring gear 8. It will be appreciated that the central axis of gear 8 is therefore eccentric to the axis of spindle 1.
Arranged in mesh with gear 8 is an externally toothed pinion 9 which encircles bush 6. Pinion 9 has an integral flange 9a which is also integral with an annular dial member 10. The dial member 10 has a knurled peripheral rim 10a to facilitate turning thereof and is provided around its periphery with graduations in English units. The periphery of the ring gear 8, which is immediately adjacent member 10 is, on the other hand, marked around its periphery in metric measurements, these members being shaped and positioned so that their peripheries coincide at a viewing location.
The enlarged outer end 6a of bush 6 is formed with a ring 11 of serrations which normally mesh with complementary serrations 12 on the inside surface of the dial member 10. The dial member 10 is displaceable rightwards in FIG. 2 to disengage the respective serrations (for the purpose to be described) but the serrations are normally maintained in engagement by a spring 13 acting between the integral flange 9a on the dial member 10 and the enlarged end 6a of bush 6.
The principle of operation of the unit is that, as spindle 1 rotates in use, bush 6 turns at the same speed and drives the dial member 10 by way of the intermeshing serrations; the gear 8 is driven from member 10 by way of pinion 9. The ratio of the number of teeth on pinion 9 to those on gear 8 is chosen so that the number of graduations through which member 8 moves for a particular displacement of spindle 1 is the metric equivalent of the number of English graduations through which member 10 moves. In this embodiment, one division on the English scale represents 0.001 in., whilst one division on the metric scale represents 0.02mm. The ratio of the teeth on pinion 9 to those on gear 8 is, in this case 127:150, although other ratios would be required according to the pitch of the lead screw.
The intermeshing serrations on member 10 and bush 6 provide a facility for zeroing the gear 8 and the dial member 10 as is generally required when the unit is used on quick power traverse machine tools. Thus, to zero the dials, the dial member 10 is moved to the right in FIG. 2 against the action of spring 13 until the serrations on the member disengage from the serrations on bush 6. The dial member 10 is then turned to the appropriate position (usually the zero position) and released, whereupon spring 13 returns the components to the FIG. 2 position in which the serrations are again in mesh.
Of course, a similar effect could be achieved by providing alternative means for releasably locking the bush 6 to the dial member 10. In one example, a clutch means is provided in the form of a lever mounted om the bush 6 and movable radially to engage or disengage teeth on the lever with the serrations on the member 10. In another example, the clutch may comprise a slidably releasable ring gear adapted normally to mesh with the teeth of the bush 6 and the member 10.
Mounted on the flange 7 of base plate 2 at the viewing location of the unit is an indicator 14 which is secured by screws 15. As can be seen from FIG. 1, the indicator is of rectangular shape and is formed with a pair of datum marks, one for each dial member. Alternatively, the indicator plate 14 could be slidably mounted for movement between two positions in each of which the scale on one of the dial members is masked, whilst the other is exposed to view.
Where the operation of the machine tool does not involve rapid traverse rates, it may be found preferable to replace a toothed clutch arrangement by a plunger drive as shown in FIG. 3, in which like reference numerals have been given to like parts of FIGS. 1 and 2. However, instead of the interengaging serrations 11 and 12, the confronting surfaces of the bush 6 and the dial member 10 are plain, but the bush 6 is provided with a radially extending bore 6b, communicating with an axially extending bore 6c. Two cylindrical plunger members 20 and 21 are received in bores 6b and 6c respectively and each member has one end surface machined at 45° so as to confront the correspondingly machined surface of the other member.
A threaded spigot 22 extending from the bush 6 receives a zeroing knob 23 which, when screwed in, bears against the outer end of the plunger 21, forcing the angled end thereof against the plunger 20 and thus urging it radially outwards to engage the plain surface of the dial member 10. Unscrewing the knob 23 will, of course, release the connection.
The form of the invention described above shows an indicator unit for converting English measurements to metric on machine tools constructed to normally operate in inches. It is to be understood that a unit constructed according to the invention for use on a machine tool which normally operates in metric measurements would be essentially similar. The differences would be that a gear ratio of, say, 100:127 might be used, ring gear 8 would carry English markings and the spacing and arrangement of the scale graduations would be appropriately amended. Thus, in such an instrument, one division on the metric scale may represent 0.02mm and one division on the English scale 0.001 in.
It will be understood that the choice of gear ratio, several examples of which have been mentioned above, depends both upon the lead screw of the machine tool, and upon the nature of the conversion required, metric/English or English/metric. A gear wheel commonly used in this type of tool is one having 127 teeth, and therefore it is convenient to choose the meshing gear so that the correct ratio with 127 is achieved. Conversion may be accurately achieved with for example a ratio of 150:127 where the screw lead is measured in multiplies of 1/10th inch, and a 140:127 will be preferred where the screw lead is measured in multiples of 1/8th inch. | A conversion unit for attachment to a machine tool constructed to operate normally in English units of measurement so that the machine tool may be used directly in metric units, or vice versa. The unit comprises an externally toothed gear wheel which may be fitted to a screw of the machine tool to turn with it, and an internally annular gear eccentrically mounted to mesh with the other gear, the number of teeth on the gears being chosen so that the correct conversion ratio is produced, the measurements being readable from graduated scales.
BACKGROUND OF THE INVENTION. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application, Ser. No. 12/959,371, filed Dec. 3, 2010, which claims priority to U.S. Provisional Patent Application No. 61/267,421, filed on Dec. 7, 2009, which is hereby incorporated by reference.
FIELD OF INVENTION
[0002] This invention relates to methods, systems, and apparatus for transferring computer messages.
BACKGROUND OF THE INVENTION
[0003] A data transmission technology exists which is called “Fibre Channel” (FC), and this technology has been around since the early 1990s. This FC technology is made up of both electrical specifications and a protocol specification called FCP (Fibre Channel Protocol) which define the packaging of messages that control the operation and encapsulate commands, data, responses, and other messages. A technical committee called T11, which is a committee within INCITS (the Inter National Committee for Information Technology Standards), is responsible for all the international standards dealing with Fibre Channel. INCITS is accredited by, and operates under rules approved by, the American National Standards Institute (ANSI). In 2009 the T11 technical committee defined a new standard (accepted by INCITS in 2010) called FCoE (Fibre Channel over Ethernet). The primary reference document for the FCoE standard can be found at the T11 website and is known as “FIBRE CHANNEL BACKBONE 5 (FC-BB-5) rev. 2.00 (document T11/09-056v5). This FC-BB-5 standard has been approved by ANSI and published on May 2010 as INCITS 462:2010. This FC-BB-5 standard defined how Fibre Channel Protocols (FCP) could flow over a special Ethernet Network which is defined as a “Lossless Ethernet” (but called herein just “Ethernet”). The Ethernet frames that carried the FCP were called FCoE frames. In order to handle these new kinds of frames and protocols, a structure was defined for a new type of device called a Fibre Channel Forwarder (FCF). This device (FCF) was a combination of a Fibre Channel Switch and Ethernet ports (sometimes including an Ethernet switch). The FCF was able to convert FCoE frames to traditional FC frames and vice versa. There was also a structure defined for a new type of device called a Converged Network Adapter (CNA). This device was a combination of a normal Ethernet Network Adapter and a Fibre Channel Adapter.
[0004] The FCF was required in order to establish logical connections between the end point devices (e.g. systems and storage controllers). The FCF was also required in order to pass messages between the end point devices. That is, the FCF required messages (commands, data, responses, etc.) to flow through the FC parts of the FCF.
[0005] There is a capability within FC that permits ports to directly connect to each other and bypass the FC Switch itself. This capability was used as part of FC Loop configurations, and for a Switchless connection between the ports (i.e. Point-to-point or direct FC wire interconnects).
[0006] Within FCP are two important concepts for this discussion, one is the establishment of the Logical/Physical link from the System Adapter to the FC Switch (or directly wired to the peer System Adapter), and the other is the establishment of the logical End-To-End connection/path from one adapter through the FC Switch to the other adapter (or directly via a FC wire to the peer Adapter). The (Logical) link establishment is accomplished in FC Switched Fabrics by each endpoint “Logging” into a FC Switch and making their identities known to the switch (and other devices). In a direct wired connection one of FC Adapters Logs directly into the other. These logins are done with a set of protocols known as the FLOGI (Fabric Login) and FLOGI LS_ACC (Fabric Login Link Services Accept called herein, FLOGI ACC) which are used in a process that establishes a logical link to the FC Switch or directly to a peer FC Adapter. The End-To-End logical connection/path is established via a set of protocols known as PLOGI (Port Login) and PLOGI LS_ACC (Port Login Link Services Accept called herein, PLOGI ACC). (The PLOGI process is required even if the End Points are directly connected.) Sometime after the completion of these login processes, the Upper Layer Protocol (ULP) can send its messages (commands, data, responses, etc.). An example of an ULP is SCSI (Small Computer System Interconnect) which is a storage Input/output (I/O) protocol and is one of the traditional ULPs carried by Fibre Channel.
[0007] The actual FC protocol which defines the connection requests and the accepting protocol for connection establishment directly between End nodes is defined in the T11 Draft Standard which can be found at the T11 Web site www.t11.org and is known as Fibre Channel Link Services-2 (FC-LS-2) Rev 2.12 (T11/09-260v2), Project 2103-D. And that draft standard is included herein by reference. This Invention specification refers to that draft standard as the “FC-LS-2” draft Standard (or just as FC-LS-2).
[0008] The FCoE FC-BB-5 standard, as mentioned above, has defined how the Fibre Channel Protocol (FCP) can operate within an Ethernet environment; as part of this new environment the Ethernet enabled FC Switch is called an FCF (Fibre Channel Forwarder) and the End Adapters are called CNAs (Converged Network Adapters). They are called CNAs because they can not only handle the normal Ethernet Frames (that carry messages for normal communication), but also carry FCP messages. Therefore, a single adapter and port could carry both the FCP protocol (in FCoE frames) and other Ethernet protocols, which are all converged into a single adapter called a CNA. (Refer to FIG. 2 —Overview of an FCoE Converged Network Adapter.)
[0009] In a Real FC network of devices, the Adapter is often called the ENode (for End Node) and the element within the ENode that controls the connection point is called the N_Port (for eNd node Port), and the connection point in the FC Switch is called the F_Port (for Fabric Port). Since within FCoE the physical Ethernet link could be carrying many different logical links, the links between the CNAs and the FCFs are called Virtual links; the N_Ports and F_Port functions are called VN_Ports and VF_Ports (where the V stands for Virtual).
[0010] In FCoE the ENode (see FIGS. 2 — 204 and FIGS. 3 — 307 ) is the entire FCoE/FC part of the adapter that does not include the Ethernet NIC (Refer to FIGS. 2 — 201 and FIG. 3 — 301 ). (Note: This invention specification will refer to the combination of the FCoE_LEP (Link End Point) ( 304 in FIG. 3 ) and the corresponding VN_Port ( 305 in FIG. 3 ) as just the VN_Port.)
[0011] In order for FC packets to flow on an Ethernet network they must be encapsulated in Ethernet frames. That means the source and destination 48 bit Ethernet media access control (MAC) address of the ports have to be known and placed into the address fields of the Ethernet Frames. These encapsulated FC packets are known as FCoE Frames (Refer to FIG. 4 —FC's Encapsulation in Ethernet which includes the Source MAC Address— 402 , and the Destination MAC Address— 403 ). Therefore, in an FCF environment, the FCF must advertise its own MAC addresses to ENodes and also dynamically build & assign a MAC address (for the VN_Port) that is made up of a FC port identifier known as the “N_Port_ID”, and an FCoE identifier known as an FC-MAP. (Refer to FC-BB-5 Standard for the detail layout of the FC-MAP value.) Both of these identifiers are 24 bits long and when concatenated together make up the assigned 48 bit MAC address of the VN_Port. This is called a Fabric Provided MAC Address (FPMA).
[0012] As part of the FC-BB-5 FCoE specification is a sub-protocol called FIP (FCoE Initiation Protocol). (Refer to FIG. 5 FIP Message Encapsulation in Ethernet, which includes the Source MAC Address— 502 , and the Destination MAC Address— 503 .) FIP was created in order to discover the environment, and devices that are part of an FCoE Fabric.
[0013] It is important to understand that even though the FC standards did permit ENodes to connect directly to other ENodes, the FCoE standard (FC-BB-5) did not permit it (neither via a point to point Ethernet wire, nor via an Ethernet switched network that did not include an FCF). (Refer to FIG. 1 c ; and note the Link 13 that cannot be used by the FC-BB-5 standardized FCoE. Also refer to FIG. 1 d and note that the internal path within the Ethernet Switch (A) 56 , from Link 52 to Link 57 , can also not be used by devices which followed the FC-BB-5 standard for FCoE.)
SUMMARY OF THE INVENTION
[0014] The FC-BB-5 requirement for FCoE frames to traverse the FCF device added additional path length and additional latency which might otherwise be avoided if there was a more direct path through either point to point wires or Ethernet switches. There was a need therefore for new processes, procedures, and protocol elements which would permit the creating of a “Shortcut” path which could bypass the FCF such that FCoE messages could travel from End device adapter to End device adapter without having to go through the FCF. (Refer to FIG. 1 a and FIG. 1 b .) In other words there was a need for an End device adapter to communicate with other End device adapters across an Ethernet network without the FCF (or FC Switch) involvement, as is possible with Real FC End device adapters. Since protocols used by FCoE End device adapters operate on an Ethernet network, this invention extends the FC direct connection concept to FCoE and permits two FCoE type device adapter (CNA) ports to connect directly to each other, via an Ethernet network switch (or a single Ethernet wire), but without a FCF type device being involved.
[0015] Since an Ethernet adapter cannot (in general) tell if it is separated from a remote Ethernet adapter by an Ethernet switch or a single Ethernet wire, when ever this invention specification talks about direct End Node communication/interconnection it should be understood that it implies use of Ethernet switches or a single Ethernet wire to physically connect the End Nodes. And whenever this specification talks about an Ethernet network it also implies (depending on context) either a single Ethernet wire or a network that includes one or more Ethernet switches.
[0016] This invention brings together the FC capabilities of direct interconnection with the Ethernet network. It will therefore bypass (or Shortcut around) any requirement for an FCF to be involved. This new capability is called (herein) the “Direct Mode” (or “Direct Mode Adapter Based Shortcut” or “Direct Mode Shortcut”).
[0017] In Direct Mode the connection between the CNAs through the Ethernet network is also called a Virtual Link (as is the link between CNAs and an FCF, described above in the background).
[0018] Depending on context, the term CNA (herein) will often imply the ENode or the ENode/VN_Port. However, depending on the context it can also mean the combination ENode and the Ethernet Adapter. The term “peer” will refer, in general, to an object on a specific side of a connection (such as the Local CNA peer, or remote VN_Port peer, etc.), and the term “peers” will refer, in general, to objects that are (or could be) on opposite sides of an FCoE logical End-to-End connection (direct mode or otherwise). Also the term “Ethernet network”, herein, refers to an Ethernet network that connects CNAs with only with a single wire or with what is known as Layer 2 devices (such as Ethernet switches) and has no means to route messages to otherwise separate Ethernet networks.
[0019] In the FC Storage related protocol, the Host Computer System (or other device) that needs to read or write data is called an Initiator, and the Storage System (aka Storage Controller) is called the Target. Those terms will also be used in this specification of the invention.
[0020] This invention permits an FCoE environment to have FCoE processes and protocols directly between peer CNAs (ENodes) when they are connected together via a single Ethernet wire or via an Ethernet switch. That is, the goal of this invention is to permit the commands, data, responses, control messages, etc. to flow, directly between the peer CNAs (VN_Port to VN_Port), “Shortcutting” around the requirement for FCFs to be involved. This idea of a Direct Mode FCoE process will only work when the peer CNAs are enabled/configured for this new “Direct Mode Adapter Shortcut” feature and are located within the same Ethernet network. If it is necessary for messages to flow between two or more networks, then real FC Switch functions are needed and a fully functional FCF will be required to interconnect the networks and handle the messages, as is the case before this invention.
[0021] This invention specification does include some advantageous example layouts of some new FIP type messages, however, the content and layout of these new (example) FIP type messages can be altered and (if they contain the key information) still have the desired effect on the actions described in this invention. Further, it is possible to use even a different Ethernet Type, and still have the desired effect. Two of these new FIP messages are intended to be used to insure that a generated FPMA formatted MAC address is not duplicated in the network. There are other techniques that can be used which may require other protocols or processes to ensure that the generated FPMA MAC addresses are unique, and those protocols/processes should be considered compatible with this invention. Even though this invention specification talks about Initiators issuing some FIP or FCoE messages, and a target responding, this terminology is usually used only for process clarity, since it is also possible, in many cases, that a target may be the initiator of a FIP message, while the Initiator can be the responder to the FIP message. And such an interaction should be considered compatible with this invention. This also means that when Multicast messages are sent (for example) to “All-Initiator-MACs” or “All-Target-MACs” it should therefore be read as being sent to All ENode MACs that are enabled/configured for Direct Mode Shortcut operations.
[0022] In an environment without an FCF, the ENodes must advertise their existence and MAC addresses to each other. Since there is no FCF, the ENodes must dynamically create their own MAC address with a process which will provide a unique MAC address similar to the FCF created FPMA, but using a default or administrator set FC-MAP. (Included in this MAC address creation process is a technique for insuring that the generated MAC address is unique within the subject Ethernet network.)
[0023] In this “Direct Mode Shortcut” invention, the VN_Port of one Direct Mode Shortcut enabled CNA can send Fibre Channel Protocol message (within an FCoE frames) directly to a VN_Port of another Direct Mode Shortcut enabled CNA after the End-to-End logical connection between the VN_Port peers has been fully established (after successful completion of the PLOGI/PLOGI ACC process).
[0024] The high level steps in the main process of the advantageous embodiment of this invention are as follows:
[0000] 1. The CNA peers will perform FCoE (FC-BB-5) Discovery processes to determine if any FCFs are available for connections. If no FCFs are found, or if specified by an administrator, the following steps will be performed.
2. The ENodes in the Network will create (generate) MAC addresses for each VN_Port that they intend to support. They will either use a local or remote generation technique that guaranties no duplicates in the network, or they will validate that the generated MAC address is unique by testing it by sending a test message, and waiting to see if a Conflict Response Message is returned, if so, then the MAC address generation process will repeat.
3. The ENodes (for example: Initiators) will send out FCoE FIP Discovery Solicitations that are Multicast to (for example) “All-Target-MACs”. Targets which receive the Solicitation should respond with a Unicast Advertisement FIP message back to the Solicitating ENode (e.g. Initiator). This Response (Advertisement) FIP Message should (in the preferred implementation) have the general format of the FCoE FCF FIP Advertisement (Refer to FC-BB-5). However, it will also contain an indication that this Response (Advertisement) is being sent from an ENode (e.g. Target) instead of from an FCF. This interchange gives descriptive information about the Target to the Initiator (and vice versa) which will permit the Initiator to chose between all the returned responses and select the Targets to which it wants to create a Virtual Link.
4. The Initiators will issue the FCoE FLOGI FIP Messages to selected Targets and the Targets should respond with FCoE FLOGI ACC. Upon the receipt of the FCoE FLOGI ACC the Virtual Link can be assumed to be established, and the VN_Ports can exchange FCoE PLOGI/PLOGI ACC, etc. and then function as if they are in a Point-to-Point connection.
5. ULP messages (e.g. commands, data, responses, etc.) will then be able to flow directly between the VN_Port Peers.
6. The ENode controller (for example the Target ENode) will periodically advertise its available VN_Ports by sending Multicast Advertisements to (for example) “All-Initiator-MACs” starting from the time it discovers that it is operating in Direct Mode (and obtains its VN_Port MAC addresses).
7. All ENode controllers will periodically send (e.g. multicast) Keep Alive FIP Messages, on behalf of its established VN_Ports (if any), to peer VN_Ports.
8. End-To-End logical connections may be terminated via the normal FCoE FC-BB-5 Standardized processes (e.g. Fabric Logoff—LOGO and LOGO LS_ACC—Logoff Accept). And then no messages should be sent or accepted between those VN_Port Peers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In the drawings, which form a part of this specification:
[0026] FIG. 1 a is a topology configuration example of an FCoE Network without an FCF. It shows Host Systems and their connections to Storage Controllers through an Ethernet Network made up of Ethernet Switches. The Ethernet Links physically connect these various components.
[0027] FIG. 1 b is another topology configuration example of an FCoE Network without an FCF. It shows Host Systems and their connections to Storage Controllers through a single Ethernet Switch. The Ethernet Links physically connect these various components.
[0028] FIG. 1 c is a topology configuration example of an FCoE Network (with an FCF). It shows Host Systems and their connections to Storage Controllers through an Ethernet Network made up of Ethernet Switches and a Central FCF Function Point. The Ethernet Links physically connect these various components.
[0029] FIG. 1 d is another topology configuration example of an FCoE Network (with an FCF). It shows Host Systems and their connections to Storage Controllers through a single Ethernet Switch and a Central FCF Function Point. The Ethernet Links physically connect these various components.
[0030] FIG. 2 is an overview of a typical high level schematic for an FCoE Adapter known as a Converged Network Adapter (CNA). It shows how the 3 major components/functions (FC functions, FCoE Functions, and NIC Functions) fit together and interface to the system and to the External network. Also the ENode is indicated.
[0031] FIG. 3 is a more detailed schematic look at the various components that make up an FCoE Converged Network Adapter (CNA). The pair of entities known as the Link End point (FCoE_LEP) and the VN_Port is shown as is the ENode, and the ENode FCoE Controller.
[0032] FIG. 4 shows the layout of an FCoE Ethernet Frame which encapsulates a Fibre Channel Packet.
[0033] FIG. 5 shows the layout of a FIP (FCoE Initiation Protocol) Ethernet Frame which contains a FIP Operation Section that contains the Operation Code and SubCode, Length, Flags, as well as the Operation's Descriptor List.
[0034] FIG. 6 shows a Layout of the Operation Section of the VN_Port MAC Address Verification Solicitation FIP message. This layout includes the generated “Potential. VN_Port MAC Address”.
[0035] FIG. 7 shows a Layout of the Operation Section of the VN_Port MAC Address Conflict Response FIP Message.
[0036] FIG. 8 shows a Layout of the Operation Section of the Target VN_Port Advertisement FIP Message. And it shows the new “T” Flag.
DETAILED DESCRIPTION OF THE INVENTION
[0037] The purpose of this invention can be seen in the example configuration topology shown in FIG. 1 a , where link 113 is to be used as a “Direct” path for the FCoE/FIP messages to travel from one of the Host Systems 100 to one of the Storage Controllers 112 through Ethernet Switches (A 103 & B 109 ). This “Direct” path is usually not available to FCoE implementations; however, this invention enables use of that path by FCoE and FIP frames. FIG. 1 b is another example configuration where things are interconnected via the single Ethernet Switch (A) 156 . In this example the Direct/Shortcut path is internal to the Ethernet Switch (A) 156 .
[0038] In addition to the use of the Direct/Shortcut path between the CNAs, this invention eliminates the involvement of the FCF, thus making this more than just a shortcut for the ULP, but a complete Direct Mode Shortcut between the CNA peers as can be seen in FIG. 1 a and FIG. 1 b with CNAs Peers 101 / 111 and 151 / 158 .
[0000] (Note: In this specification, there are functions that are shown as being performed in the CNA, ENode, VN_Port, etc., however, those should be considered as example implementations since there can be implementations of this invention in which these functions are performed in other locations, including inboard (inside) the systems'/devices' Central Processing Units—(or their support chips) in Hardware, Microcode, or Software; or Outboard (on an adapter chip or card) in Hardware, Microcode, or Software; or any combination of inboard or outboard implementations).
[0039] Referring to FIG. 3 —The term ENode/VN_Port will be used whenever the functions' placement is an implementation option which could either be accomplished by the ENode's FCoE Controller 303 (perhaps on behalf of the VN_Port) or by the VN_Port 305 and its FCoE_LEP 304 . Also some of the various functions that are performed by one of the pair of components known as FCoE_LEP 304 and VN_Port 305 will be referred to (herein) as functions performed by the VN_Port or the ENode/VN_Port. And the function of the ENode FCoE Controller ( 303 ) will often be referred to as being performed by the ENode.
Main Process Steps
[0040] The most advantages embodiment of this invention is one that includes the following processes:
[0000] 1. The CNAs 101 / 111 & 151 / 158 will perform the FCoE (FC-BB-5) discovery process which has the intention to determine if the configuration includes FCFs. If an FCF Advertisement response does occur, then the FC-BB-5 processes can proceed as is the case before this invention. The following steps are followed if the FCF discovery processes times-out without a FCF Advertisement response (or with configuration/administrative direction).
2. Each of the ENodes in the network 101 / 111 & 151 / 158 will create VN Port MAC addresses that it intends to use when it instantiates (cause it to become operational) an FCoE_LEP 304 and VN_Port 305 pair (the pair will be called herein, just the VN_Ports). The MAC address will be created in a form known as FPMA. The Direct Mode FPMA is a 48 bit MAC address where the high order 24 bits are equal to the default or administratively determined FC-MAP (a set of bits defined by FC-BB-5 to represent the FCoE network) and (most of) the low order 24 bits are dynamically and randomly-generated or chosen by the ENode FCoE Controller 303 . The low order 24 bits will also be known as the N_Port_ID of the VN_Port.
[0041] Since the N_Port_ID must be unique within the FCoE Network (as does the VN_Port MAC address, the ENode FCoE Controller 303 must insure that the generated N_Port_ID (and therefore its MAC address) is unique. There are a number of ways that can be used to ensure this uniqueness, including the technique described herein where the ENode tests this uniqueness by first creating the proposed VN_Port MAC address then preparing to receive messages from that MAC address, and then sending (multicasting)—the MAC address just created—in a FIP message (refer to FIG. 5 for the general format of a FIP message) called, herein, the “VN Port MAC Address Verification Solicitation” FIP message (Refer to FIG. 6 for an example of the possible layout of the operation section of the FIP message and see the “New FIP Messages” section below).
[0042] After sending this Verification Solicitation, the ENode may wait for an implementation determined time period, and if no “VN_Port MAC Address Conflict Response FIP Message” is received (refer to FIG. 7 for an example of the possible layout of the Operation Section of the FIP message and see the “New FIP Messages” section below) then the generated MAC address (and the embedded N_Port_ID) can be assumed to be unique within the network. At that point, the ENode will record that MAC address as being one that may be used when it instantiates a VN_Port. If on the other hand, a “Conflict Response FIP Message” ( FIG. 7 ) is received the MAC address must be discarded by the ENode, and it should disable its ability to receive messages for that MAC address. Then the ENode must again attempt to generate a unique MAC address/N_Port_ID etc. until uniqueness is obtained.
[0043] Then, at any time in the future if the ENode receives a “VN_Port MAC Address Verification Solicitation FIP Message” ( FIG. 6 ), it must return to the sender a “VN_Port MAC Address Conflict Response FIP Message” ( FIG. 7 ).
[0000] Note: In order to lessen the probability of conflict—when an ENode generates its own N_Port_ID and uses it in a VN_Port MAC address, the ENode should insure it is using an appropriate random number generator.
3. Each of the (for example: Initiator) CNA ENodes' FCoE Controllers 303 will request descriptive information by sending out FCoE Discovery Solicitation FIP Messages (refer to FC-BB-5) but instead of being addressed to Multicast address “All-FCF-MACs” as is the case with normal FC-BB-5, it will be sent to the Multicast address of (for example) “All-Target-MACs”. ENodes (for example: Targets) which receive this solicitation should respond for each of its established or potential VN_Ports with a Unicast Advertisement FIP message back to the solicitating ENode (e.g. Initiator) with descriptive information. The Initiator ENodes will use the information to create a list of potential Targets and their MAC addresses from which it will make selections. This means that each of the Unicast Advertisement Response FIP Messages will contain one of the MAC addresses of an established or potential Target VN_Port. This Advertisement FIP Message should (in the preferred implementation) have the same general format of the FCoE FCF FIP Advertisement (refer to FC-BB-5 and FIG. 8 and see the “Modified FIP Message” section below).
[0044] This solicited Target Advertisement FIP message also needs to be padded out with zeros to the maximum FCoE/FIP message length. The receipt of this advertisement message by the Initiator will ensure that the path has enough capability to support the maximum FCoE/FIP message length. If the path is not capable of handling the maximum FCoE/FIP message the message will be dropped by an intervening Ethernet switch and the Initiator will not know about the Target VN_Port and will not send any subsequent messages to it.
[0000] 4. The Initiator ENode will issue a Fabric Login (FLOGI) packed in a FCoE FIP Messages (per FC-BB-5) to selected Targets and the selected Targets should respond with the Fabric Login Accept (FLOGI ACC) packaged in a FCoE FIP Message (per FC-BB-5). When the Initiator receives the FLOGI ACC FIP Message, the Virtual Link is established, and the peer VN_Ports on each side of the Virtual Link can then establish the Logical (End-to-End) connection by exchanging FCoE PLOGI/PLOGI ACC, etc. messages and then continue to function as if they are in a FC Point-to-Point connection. (Note: Either Direct Mode enabled ENode VN_Port peers, on either side of the Virtual Link, may issue the (FCoE) PLOGI message or (FCoE) PLOGI ACC message as detailed in FC-LS-2—section 6.2.2.4.)
5. ULP messages (e.g. commands, data, responses, etc.) and other FCP messages will then be able to flow directly between the VN_Port Peers. When either side of the VN_Port to VN_Port Virtual link has an FCP message to send to the other side it may package it in an FCoE frame (See FIG. 4 ) and send it to the other via normal FCoE processes (but without the involvement of an FCF).
6. The ENode FCoE controller 303 (for example: the Target ENode FCoE Controller) will periodically advertise its VN_Ports by sending (Multicast) advertisements to (for example) “All-Initiator-MACs” starting from the time it discovers that it is operating in Direct Mode and has acquired its VN_Port MAC addresses. This will occur on a frequency equal to an FC-BB-5 specified value known as the FKA_ADV_Period (default=8 seconds). This process permits newly connected ENodes (for example Targets/Storage Controllers) 112 to let other ENodes (for example) Initiators 101 know that they are now available. This advertisement is also used as a Keep-Alive message which will ensure that Initiators (for example) can tell if the Virtual Link between the ENodes is still active.
7. All ENode FCoE controllers 303 (whether Initiator or Target) will periodically send (e.g. Multicast) Keep Alive (advertisement) FIP type Messages, on behalf of their established VN_Ports (if any), to peer VN_Ports. It is also possible for the period value to be set (e.g. by an administrator) to various values including zero meaning that this type of FCoE Keep Alive message should not be issued perhaps because this connection is a switchless connection.
8. End-To-End logical connections may be terminated via the normal FCoE (FC-BB-5) standardized processes and FIP messages (e.g. Fabric Logoff—LOGO and LOGO LS_ACC—Logoff Accept). And then no messages should be sent or accepted between those VN_Port Peers.
New FIP Messages
[0045] The following are examples of the advantageous embodiments of the New “Direct Mode Shortcut” related FIP messages.
[0046] There are 2 new FIP messages that are needed which are called (herein):
[0000] 1. The “VN_Port MAC Address Verification Solicitation” FIP Message (Refer to the operation section shown in FIG. 6 ).
2. The “VN_Port MAC Address Conflict Response” FIP message (Refer to the operation section shown in FIG. 7 ).
[0047] These FIP messages are encapsulated in an Ethernet Frame as shown in FIG. 5 . The Operation Section of these two new FIP messages, shown in the example layouts FIG. 6 , and FIG. 7 are used to determine if a generated VN_Port MAC address is unique within the network.
[0000] 1. The VN Port MAC Address Verification Solicitation FIP Message is (in this example) a FC-BB-5 compatible FIP type message form. (Refer to FIG. 5 ) This FIP Message contains the Operation Section shown in FIG. 6 .
[0048] This operation section contains:
[0000] a. The FIP Discovery Operation Code 609 equal to 0001h and the SubCode 610 equal to 03h.
b. The Descriptor List length 608 equal to 2.
c. The MAC Address Descriptor 607 (Type=2 & Length=2) that contains the potential VN_Port MAC Address 603 . This is the MAC address dynamically generated by an ENode as a potential VN_Port MAC address. Before a VN_Port can be instantiated it must have a MAC address that is unique within the network. In order to ensure that a MAC address which is generated for an VN_Port is unique, this message will be sent (multicast) to determine if there already exists a VN_Port with the same MAC address.
d. The Frame will be padded out 600 with zeros to reach the minimum Ethernet Frame length.
If there is a VN_Port with this MAC address, it is expected that the “VN_Port MAC Address Conflict Response” FIP Message will be returned.
2. The VN Port MAC Address Conflict Response FIP message is (in this example) a FC-BB-5 compatible FIP type message form. (Refer to FIG. 5 ) This FIP Message contains the Operation Section shown in FIG. 7 .
[0049] This operation section contains:
[0000] a. The FIP Discovery Operation Code 709 equal to 0001h and the SubCode 710 equal to 04h.
b. The Descriptor List Length 708 equal to 2.
c. The MAC Address Descriptor 707 (Type=2 & Length=2) that contains the conflicting VN_Port MAC address 703 . This is the MAC address that is a duplicate of a MAC address within the ENode issuing this message.
d. The Frame will be padded out 700 with zeros to reach the minimum Ethernet Frame length.
[0050] This message will be issued by an ENode FCoE Controller 303 if it receives a conflicting “VN_Port MAC Address Verification Solicitation” FIP Message (Refer to FIG. 6 ) since that would indicate the sending ENode has generated a duplicate VN Port MAC address.
[0051] The ENode to which this message is sent is expected to disable its ability to receive the subject MAC address, and try again to generate a unique VN_Port MAC address.
Modified FIP Message
[0052] There is one existing FC-BB-5 FIP message that (as an example) has been re-tasked and modified slightly to include a possible new informational Flag, and some new uses for existing fields. That example FIP message is the Advertisement (and Keep Alive) FIP Message (refer to FIG. 8 for the Operation Section of this FIP message) which will be formatted as is specified by the FC-BB-5 standard but with a possible new Target flag (called the “T” Flag 804 ) that will be set in the currently reserved Flags area of the Operation Section of the FIP message.
[0000] (Note: the use of the word “Target” in the Drawings (and in the text below) is an example, since where ever the word Target is used, the word “Initiator” could also be used when the message is sent from the initiator.)
[0053] The Advertisement FIP Message contains a FIP Operation Code 809 equal to 0001h and a SubCode 810 equal to 02h.
[0054] The MAC Address 811 will be the ENode (e.g. Target) VN_Port MAC address.
[0055] The Name field 802 may contain the name of the device—for example: the Target (Storage Controller) Name (Target_Name).
[0056] The VF_ID field 807 may contain a default VF_ID.
[0057] The FC-MAP field 805 will contain the default or administratively set FC-MAP.
[0058] The Fabric_Name field 801 may contain a default fabric name.
[0059] The FKA_ADV_Period 803 will contain the default or administratively set value.
[0060] The frame will be padded out 800 to the maximum FCoE frame size if the “S” Flag 806 is set on (S bit=1) otherwise there will be no padding.
[0061] The other flags and fields will be the same as defined in the FC-BB-5 for an Advertisement FIP Message.
[0062] With this invention the Advertisement FIP Message may now be sent from not only the FCF per FC-BB-5, but also from the ENodes (for example: Targets). When the Advertisement FIP Message's new “T” Flag 804 is set on (T=1) it will indicate that the advertisement is sent from (for example) a Target instead of an FCF. The “F” Flag 808 (the FCF flag) should be set off (F=0). It is also possible that the fact that the “F” Flag is set off, is sufficient to indicate that the advertisement is not being sent from the FCF and is being sent from (for example) the Target; in that case no “T” Flag will be needed. Any layout and approach which is sufficient to indicate that this is an Advertisement Message from an ENode (such as a) Target and not an FCF should be consistent with this invention.
[0063] The Advertisement FIP messages from an ENode (for example the Target) should also contain the ENode's (e.g. Target's) actual or potential VN_Port MAC Addresses 811 and perhaps a Name of the Target (Storage Controller) 802 . This is useful since there may be a number of different Targets (Storage Controllers) each of which have a number of ENodes, and the Initiators may want to chose which Targets they connect to and the number of connections to each. The FC_MAP 805 value (which should be set to the default or administratively set value) is carried here for compatibility reasons.
Other Considerations
[0064] In the above descriptions of all the various FIP messages it should be understood that they are only examples of layouts and Ethertypes that would be appropriate for this invention. The various new Flag bits could be located in other parts of the message and the messages would still be acceptable for this invention. This means there are other layouts and Ethertype for the new and modified messages which will be equally useful to this invention which should be considered alternatives message layouts; the FIP message examples shown are only one set of the possible embodiments and layouts that may be used as part of this invention.
[0065] Likewise it is also possible to change the FIP message code or subcode; and even with a change in the layout within a FIP message, it may still be acceptable for this invention. In fact that would include using a new FIP code or subcode to identify an appropriate FIP message instead of a Flag bit. Or using a Flag bit on a current FIP message to denote its new function. Even if a different layout is used with a new code ( 609 , 709 , 809 ) or subcode ( 610 , 710 , 810 ), if it contains the needed essential information such that the above functions can be accomplished, that should be acceptable for this invention.
[0066] In the modified FIP message, many parts of the Descriptor Lists have little value except for their compatibility with an existing FIP Message; so an alternate Descriptor List, which still contains the needed information, should be considered an acceptable alternative layout for this invention.
[0067] It should also be understood that instead of the Multicast addresses of “ALL-Target-MACs” or “ALL-Initiator-MACs” it is possible to Multicast using the currently FC-BB-5 defined “All-ENode-MACS” or “All-FCF-MACs”, or “All-FCoE-MACs” and set a flag or value that indicates who should handle or ignore the message. Likewise there could also be yet another set of Multicast values that could also cause selectivity perhaps with or without a Flag or other value. These possible variations should be considered compatible with this invention.
[0068] Throughout this invention specification the term Initiator should be read to mean—a device that has initiator functions whether or not it is within a computer host system. Likewise, the term Target should be read to mean a Storage System or Storage Controller or a device that emulates the network interactions that are expected with a Storage System or Storage Controller. | This invention permits all FCoE (Fibre Channel over Ethernet) frames to be transferred from one FCoE network adapter to another without having to traverse through a Fiber Channel Forwarder (FCF) device. After the FCF is determined not to be present, a logical End-To-End connection is established between Peer FCoE Adapters. This invention permits an FCoE message originating at an FCoE network adapter to be sent to an FCoE receiving adapter across “Ethernet” links and switches, or via a single “Ethernet” link (Point-To-Point) but without having to pass through FCF devices. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and apparatus for suppressing disturbances in the measurement of signals with a particle probe, in which a known reference voltage on a specimen is measured at at least one time.
2. Description of the Prior Art
When measuring signals with an electron probe, disturbances can occur due to contamination of the test subject and due to fluctuations of the beam current in the electron probe.
These disturbances could be nearly eliminated heretofore by a phase modulation method as discussed by H. P. Feuerbaum in the article "VLSI Testing Using The Electron Probe", Scanning Electron Microscopy, 1979, I, pp. 285-296, when such disturbances amount to only a few percent of the measured signal. The efficacy of this known method of phase modulation, however, no longer suffices. Such a known method of phase modulation, in particular, only eliminates the drift phenomena in a measured signal occurring as a result of disturbances. In general, such a measured signal not only drifts, but also becomes more inaccurate.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a method and an apparatus of the type generally set forth above with which the drift phenomena occurring in a measured signal can be eliminated and the accuracy of the measurement of signals can also be significantly increased at the same time.
The above object is achieved, according to the invention, by a method which is characterized in that a secondary electron signal which results from a measurement of a reference voltage on the test specimen is employed to control the operating point of a feedback circuit for suppressing the disturbance.
BRIEF DESCRIPTION OF THE DRAWING
Other objects, features and advantages of the invention, its organization, construction and operation will be best understood from the following detailed description, taken in conjunction with the accompanying drawing, on which:
FIG. 1 illustrates the principle of phase modulation as employed in practicing the present invention; and
FIG. 2 is a schematic representation of apparatus constructed and operating in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, the principle of phase modulation is illustrated. The method of the invention employs phase modulation for noise suppression in the measurement of signals with an electron probe PE (FIG. 2). This method of phase modulation is therefore explained in conjunction with the description of apparatus for carrying out the method according to FIG. 2. Apparatus for executing the method according to FIG. 2 comprises essentially a device as was described in the aforementioned publication by H. P. Feuerbaum or in U.S. Pat. No. 4,277,679, both fully incorporated herein by this reference.
In order to identify the potential at a measuring point in a specimen PR, for example, in an integrated circuit, the secondary electrons SE triggered by a primary electron beam PE are analyzed in terms of their energy in a spectrometer ST. Low-energy secondary electrons SE cannot overcome a retarding field generated within the spectrometer ST. Higher-energy secondary electrons SE are sensed by a detector DT. The energy distribution of the secondary electrons SE depends on the potential of the measuring point on the specimen PR. Given a change of this potential at the measuring point on the specimen PR, the energy distribution of the secondary electrons SE is essentially displaced on an energy scale. This shift of the energy distribution of the secondary electrons SE is identified with the aforementioned retarding field of the spectrometer ST. A feedback circuit RS is employed, the feedback circuit keeping the signal of the secondary electrons which can overcome the retarding field of the spectrometer ST constant. Changes of potential at the measuring point on the specimen PR therefore results in an identical voltage change at the retarding field electrode of the spectrometer ST (not illustrated in FIG. 2). The voltage at the retarding field electrode of the spectrometer ST therefore supplies the measured signal. The voltage at the retarding field electrode of the spectrometer ST is controlled by the feedback circuit RS. Disturbances influence the energy distribution of the secondary electrons SE triggered at the measuring point on the specimen PR. Over the feedback circuit RS, consequently, the voltage at the retarding field electrode is controlled such that the secondary electron measured signal perceived by the detector DT remains constant. Thus, however, the measurement of the potential at the measuring point on the specimen PR is falsified. This interrelationship is to be illustrated with reference to the example of contamination.
When a measuring point contaminates, then the secondary electron measured signal is decreased. As a consequence thereof, the voltage at the retarding field electrode of the spectrometer ST shifts in the positive direction. Given increasing contamination, therefore, more and more low-energy secondary electrons SE can overcome the retarding field of the spectrometer ST and can add to the secondary electron measured signal. These low-energy secondary electrons SE, however, basically deteriorate the measuring accuracy. When a measuring point is contaminated, the voltage applied to the retarding field electrode of the spectrometer ST from which the potential at the measuring point on the specimen PR to be measured is derived drifts, not only in a positive direction, but this voltage at the retarding field electrode and, therefore, the measured voltage as well, also becomes more inaccurate. Only the drift of the measured voltage, can be suppressed by phase modulation. Given this method of phase modulation, the signal of a constant reference phase, the signal likewise drifting, is also co-measured during the continuous scanning of a signal. The difference of measured signal and reference signal is free of drifts, but inaccurately reproduces changes of potential. Disturbances caused by contamination already deteriorate the measuring accuracy such that reproducible measurements in the mV range are hardly possible.
Given the method of phase modulation according to FIG. 1, the voltage at the measuring point on a specimen PR is switched back and forth between the potential to be measured and a reference voltage. It will be assumed that the reference voltage amounts to 0 volt. A period of a voltage V P to be measured is illustrated in the upper diagram of FIG. 1. When sampling the waveform of the voltage V P , the phase φ of the primary electron probe PE is usually not continuously varied but, rather, discontinuously. The primary electron probe PE thus alternately strikes the surface of the specimen PR with a discontinuously-increased phase φ, on the one hand, and then with a reference phase which is indicated in FIG. 1 with φ=0. The system for processing the secondary electron measured signals measures the voltage V G during the discontinuously-increased phase and during the reference phase and thus supplies the difference of the voltages V G as the measured result. Due to the phase modulation of the primary electron probe PE, in particular, the voltage V G contains an a.c. voltage component. This a.c. voltage component can be detected with the assistance of a lock-in amplifier and can be integrated over a number of phases of the primary electron probe PE. The voltage V L which is uninfluenced by drift disturbances is obtained as the result of this technique.
This method of phase modulation can also be applied when only a d.c. voltage is to be measured at the measuring point on the specimen PR. For example, the voltage at the measuring point can then be alternately switched back and forth during the measurement between the d.c. voltage to be measured and 0 volt. Thereby, just as given the method according to FIG. 1, the additional drift voltage C occurring as a result of contamination can be identified and subtracted from the measured curve.
The method of the invention is based on the method of phase modulation. The secondary electron signal measured in the reference phase, however, is employed in this method to such end that the feedback circuit RS is balanced to a specific operating point. When the feedback circuit RS is thereby balanced to a prescribed operating point, then the retarding field in the spectrometer ST is always maintained constant despite the disturbances which influence the secondary electron measured signal. The secondary electrons triggered at the measuring point on the specimen PR in the reference phase which can overcome the retarding field of the spectrometer ST are identified by the detector DT. The secondary electrons SE sensed by the detector DT cause a secondary electron measured signal at the output of a photomultiplier PH connected to the detector DT, the measured signal being amplified in an amplifier V1 and then fed to an electronic switch ES. The secondary electron measured signal measured in the reference phase is then received in a sample and hold circuit SH1 and, in a comparator not illustrated on the drawing, can be compared to a reference value for the secondary electron measured signal, which is identified during the reference phase. Deviation from the reference value are amplified and, in an exemplary embodiment of the invention, control the amplification of a photomultiplier PH or the gain of a following amplifier V2, or control the pulse width of the primary electrons PE via a pulse generator PU and a beam blanking system AS such that the secondary electron measured signal which is measured in the reference phase corresponds to the reference value for the secondary electron measured signal measured during the reference phase. The control of the amplification of a photomultiplier PH thereby occurs such that the output of the sample and hold circuit SH1 drives the voltage supply UP of the photomultiplier PH such that the voltage of the photomultiplier PH assumes such a value that the secondary electron measured signal, measured during the reference phase, coincides with the reference value for the measured signal.
In another exemplary embodiment of the invention, a second sample and hold circuit SH2 is connected to a second output of the electronic switch ES, the output of the second sample and hold circuit SH2 again being connected to the amplifier V2 whose output is again directly connected to the retarding field electrode of the spectrometer ST, whereby the feedback loop RS is closed. When the voltage to be measured is available at the measuring point on the specimen PR, the secondary electron measured signal is relayed by the electronic switch ES to the sample and hold circuit SH2.
In another embodiment of the invention, the gain of, for example, the amplifier V2 can be controlled by way of the output of the sample and hold circuit SH1, as indicated by broken lines, such that the secondary electron measured signal, measured during a reference phase, coincides with the reference value of the measured signal.
Further exemplary embodiments of the invention are based on the fact that, given constant gain within the feedback loop RS, the reference value for the secondary electron measured signal is regulated. This regulation occurs such that the secondary electron measured signal, measured during a reference phase, is employed as a new reference value for that secondary electron measured signal which is employed for identifying a voltage to be measured at the measuring point on the specimen PR.
According to the method of the invention, the feedback circuit RS holds the barrier in the spectrometer ST constant independently of disturbances. Therewith, the secondary electron measured signal, measured in other phases which are not reference phases, is free of disturbances. The subtraction of the measured signal from the reference signal standard in phase modulation can basically be eliminated in view of the method of the present invention. Since a standard subtraction, however, separates the measured signal from the background, it should nonetheless be carried out.
The bandwidth available in practicing the present method for suppressing disturbances can be estimated at approximately 10 kHz. Therewith, disruptions due to beam current fluctuations such as occur given field emission cathods can also be suppressed without an operation on the electron optics being required.
Basically, the method of the invention which controls the gain or the reference value is superior to the method which controls the pulse width of the primary electrons PE because, given variation of the pulse width of the primary electrons PE, the chronological resolution of the arrangement also alters. When measuring very fast rising edges, this can lead to step-like signal progressions, i.e. a method of the invention which varies the pulse width of the primary electrons PE can only correct small disruptions given fast signal changes in comparison to other methods of the invention.
The method which controls the photomultiplier amplification requires the line SP, shown in dot-dash lines. The method which controls the gain of the amplifier V2 requires a control line SW, illustrated with a dot-dash line having two dots per dash. The method which controls the pulse width of the primary electrons PE requires a control line SB, shown by a broken or dash line. The method which regulates the reference value can, for example, likewise utilize the control line SP and control the voltage of the photomultiplier.
In practicing the present invention, one obtains the following advantages:
The invention enables an automatic operating point adjustment given which the previous individual adjustment of the operating point is eliminated.
The invention enables a suppression of beam current fluctuations. Disturbances which exceed the signal by a multiple can be suppressed, particularly given control of the photomultiplier voltage. Therefore, use of field emission cathods should be possible in electron beam mensuration technology.
The invention enables a suppression of contamination influences. The shift of the operating point due to contamination is constantly compensated during a measurement. The measuring errors previously caused by drift are reduced by a number of magnitudes.
The operation of the electronic switch ES, the sample and hold circuit SH1 and the sample and hold circuit SH2 illustrated in FIG. 2 can also be basically met by a single sample and hold circuit and an electronic switch connected to the output of the sample and hold circuit, one output leading therefrom to the amplifier V2 and the other output leading therefrom to the junction of the various control lines SP, SB, SW.
Although we have described our invention by reference to particular illustrative embodiments thereof, many changes and modifications of the invention may become apparent to those skilled in the art without departing from the spirit and scope of the invention. We therefore intend to include within the patent warranted hereon all such changes and modifications as may reasonably and properly be included within the scope of our contribution to the art. | A method and apparatus suppress a disturbance in the measurement of signals with a particle probe by providing and measuring a known reference voltage on a specimen at at least one time and using the measurement for eliminating the drift phenomena appearing in a measured signal and enables a significant increase in the precision of the measurement of signals. A secondary electron signal which results from a measurement of a reference voltage controls the operating point of a feedback circuit for suppressing the disturbance. | 6 |
BACKGROUND OF THE INVENTION
This invention pertains to a device for facilitating the folding of T-shirts, dress shirts and sweaters or the like.
The volume of shirts and sweaters handled by commercial launderers and retailers requires that the folding of these goods be accomplished with relative ease and a high degree of efficiency.
Moreover, uniformity of appearance is also necessary in order that the product may be attractively displayed and packaged.
However, in the shirt apparel industry folding is conventionally done in a manual manner, and uniformity of appearance and ease of operation are not easily achieved.
The present invention is designed to assist retailers and the laundry industry in achieving these goals.
Simplicity and economy are essential attributes for any folding device because the cleaning industry operates on a volume basis with relatively low capital investment and low profit margins. Hence, expensive and complicated folding machinery does not satisfy the industry's need nor does it provide a solution to the problems faced by low margin operators. The mechanism disclosed herein is straight-forward in design and inexpensive to produce and, therefore, it meets the needs of any enterprise which may be engaged in the folding of shirts and sweaters.
Although the above discussion has been directed to the equipment needs of commercial establishments, this invention also satisfies the needs of any individual for whom the folding of apparel is a tedious or bothersome task particularly in large households where shirts and sweaters are in abundance. Moreover, the operation of this device can be taught without difficulty and it can be embellished with writing or designs so as to make its use more attractive to children.
The folding mechanism of the invention also satisfies a need for those who usually do not participate in homemaking chores.
SUMMARY OF THE INVENTION
This invention comprises a multi-creased device that allows an operator to uniformly manipulate shirts and sweaters in a series of steps for folding purposes. Two versions of the device are disclosed where one is utilized for folding T-shirts and short-sleeve sweaters and the other for folding dress shirts and long-sleeve sweaters.
The former is a three step folding device where the shirt width dimensions are reduced in two of the steps and the height dimension is reduced in the third step.
The latter device, that is, the apparatus used for folding dress shirts and long sleeve sweaters, involves a five step operation, two of which are needed to fold the sleeves inwardly, two are to reduce the width dimension and one step to reduce the height dimension.
The device finds particular application in large commercial operations where uniformity is required for packaging purposes. However, the device is equally useful for home use where there are a large number of shirt wearing members and the folding of such apparel would otherwise not occur.
It is therefore an object of this invention to provide a new and improved device for the manual folding of shirts.
It is another object of this invention to furnish a new shirt folding device that is characterized by economy of design and ease of operation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts an embodiment of the T-shirt folding device of the invention.
FIG. 2 illustrates the relationship of the device with respect to a T-shirt that is ready for folding.
FIG. 3 shows a first step in the T-shirt folding method of the invention.
FIG. 4 depicts the state of the T-shirt after the first step has been completed and the folding device has been returned to its original state.
FIG. 5 represents the second step in the T-shirt folding method.
FIG. 6 shows the state of the T-shirt after the second step has been completed and the folding device has been returned to its original state.
FIG. 7 illustrates the third step in the T-shirt folding method of the invention.
FIG. 8 depicts the state of the T-shirt after the third step has been completed and the folding device has been returned to its original state.
FIG. 9 shows the completed folded T-shirt.
FIG. 10 presents another embodiment of the invention where a shirt folding device for a dress shirt is depicted.
FIG. 11 illustrates the relationship of the folding device with respect to a dress shirt that is ready for folding.
FIG. 12 illustrates a first step in the dress shirt folding system of the invention.
FIG. 13 depicts the state of the dress shirt after the first step has been completed and the folding device has been returned to its original state.
FIG. 14 shows the second step in the dress folding method.
FIG. 15 represents the state of the dress shirt after the second step has been completed and the folding device has been returned to its original state.
FIG. 16 illustrates the third step in the dress shirt folding system.
FIG. 17 represents the state of the dress shirt after the third step has been completed and the folding device has been returned to its original state.
FIG. 18 shows the fourth step in the dress shirt folding method.
FIG. 19 illustrates the state of the dress shirt after the fourth step has been completed and the folding device has been returned to its original state.
FIG. 20 represents the fifth step in the dress shirt folding system.
FIG. 21 shows the state of the dress shirt after the fifth step has been completed and the folding device has been returned to its original state.
FIG. 22 shows the completely folded dress shirt.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the Drawings and in particular to FIG. 1, a shirt folding form 10 having an approximate square shape configuration, which incorporates two vertical folds 12, 14 and one horizontal fold 16, is shown. The form 10 is dimensioned such that each side 11, 13 of the square is approximately twenty-six inches in length; furthermore, the fold 16 divides the side 13 into two parts 13a, 13b which are twelve and fourteen inches, respectively, whereas, the folds 12 and 14 divide the side 11 into three parts 11a, 11b and 11c which are nine, eight and one-quarter, and nine inches in length, respectively. It should be understood that these dimensions are utilized in the preferred embodiment of the invention and they may be modified by those skilled in the art without departing from the principles set forth in this invention.
The form 10 is fabricated from a cardboard material and one of its outer layers is slit at the vertical and horizontal folds 12, 14, 16 in order to permit easy rotation of certain sections in accordance with the teachings set forth by the invention. Suitable plastic materials may also be utilized in the fabrication of form 10 without diminishing the performance of the invention.
FIG. 2 depicts the overall relationship of the form 10 with respect to a T-shirt 17 that is ready for folding. As can be readily understood the shirt 17 is laid upon the form 10 front side down by an operator so that the sleeves 18, 19 and waist extremity 21 are in approximate alignment with the respective edges 11, 13 and 13a. To facilitate the operation and to insure that an attractive folded shirt 7 results, the shirt is smoothly placed upon the form by the operator so that all major wrinkles are made to essentially disappear.
In FIG. 3 the first operational step of this embodiment of the invention is shown whereby the side 11c is grasped by the operator and rotated in a counterclockwise manner, as viewed from the waist 21 of the shirt, around the vertical fold 14. The resultant first fold in the shirt 7 is depicted above the form 10 where the right sleeve 18 and right side 23 are folded inwardly. FIG. 4 illustrates the condition of the T-shirt 7 after the first step of the folding operation has been completed and the vertical section 11c is rotated in a clockwise direction around the vertical fold 14. At this stage of the procedure, the form 10 is in its original status as shown in FIG. 2 except that the right side 23 of the shirt has been folded inwardly.
FIG. 5 represents the second step of the operation where the side 11a is rotated clockwise by the operator around the vertical fold 12. This causes the left side 25 of the shirt to fold in such a manner that the left sleeve 19 will lay upon the right sleeve 18 in the manner illustrated. By rotating the section 11a in a counterclockwise direction the form 10 is restored to its original flat orientation but the shirt 7 has now been partially folded as depicted in FIG. 6.
The third step of the folding operation is illustrated in FIG. 7 where the shirt 7 is folded at its approximate mid-point by rotating side 13a in a counterclockwise manner as viewed from the left side of the drawing around the horizontal fold 16. Since 13a is slightly shorter in length than side 13b the form allows the waist or bottom edge 21 to be positioned below the shirt's top edge 21a. This feature allows easy grasping of the shirt 7 after the folding has been completed. FIG. 8 represents the status of the form 10 after the side 13a is returned to its original flat state. In FIG. 9, there is shown the completely folded shirt 7 after being turned front side-up from its downwardly facing position shown in FIG. 8,
There has been above described an essentially three-step operation for folding a T-shirt 7 using a flat form 10 which incorporates three folds 12, 14 and 16. By proper placement of the shirt 7 upon the form, an operator can rapidly and efficiently achieve folding of the shirt 7 in only a few seconds. This is a significant achievement especially in the world of commerce such as in a manufacturing plant where T-shirts are fabricated after which they are folded and later boxed for shipment. In such an environment rapid folding is essential if the manufacturing is to be made into a commercial success.
The invention may also be readily applied to the folding of male dress shirts as illustrated in FIGS. 10-22. With reference to FIG. 10 a form 30 is shown having a plurality of folds consisting of two vertical folds 36, 38, two diagonal folds 32, 34 and one horizontal fold 40. The form 30 is also made of cardboard as ,a preferred material and one of its outer layers is slit at the folds 32, 34, 36 38 and 40 to allow ease of rotation during the folding procedure. In a preferred embodiment, the form 30 is dimensioned so that its width is approximately fifty inches and its height is approximately twenty-eight inches. The rectangular elements 44a, 44b, 44c and 44d which partially comprises the form 30 have height and width dimensions of approximately fourteen by twenty and one-half inches, respectively, where the width dimension crosses the diagonal lines 32, 34; and similarly, the height and width dimensions of rectangular elements 44e and 44f are fourteen by ten inches, respectively. The dimension along the base 43 of the triangle formed by, for example, the altitute 36 and hypothenuse or diagonal 32 is seventeen inches; furthermore, the length of the base 43a is similarly seventeen inches. The dimensions cited above may be varied in accordance with the skill of the art without departing from the essential elements which form the invention.
Referencing FIG. 11, a dress shirt 33 is placed upon the form 30 with the back of the shirt and arms facing in an upward direction, and the collar 33a being positioned beyond the edge 35 of rectangle 44e. Also, the sleeves of the shirt 33 are positioned outwardly until the cuff endings are respectively positioned beyond the edges of rectangles 44a, 44c. The front of the shirt 33 (not shown) is buttoned and in the manner previously described with respect to the T-shirt 7, the dress shirt is smooth so that it lays essentially flat upon the form 30.
The first step in the folding process for the dress shirt 33 is demonstrated in FIG. 12 where the form 30 is folded along the diagonal fold 34 by a counterclockwise rotation of the section including a portion of rectangles 44c and 44d as viewed from the side 42 or the width dimension of the form 30. The form 30 is returned to its original position in FIG. 13 after causing the sleeve 50 to be folded upon the back surface of shirt 33.
The identical procedure is followed in FIG. 14 for the second step of the operation where the form 30 is folded along fold 32 by a clockwise rotation of the section including a portion of rectangles 44a, 44b. The rotated section is returned to its original state so that form 30 is made flat as shown in FIG. 15 and the left arm 51 remains in a folded state behind the back of the shirt 33.
The third step of the shirt folding process is illustrated in FIG. 16 where the section of the form 30 which includes complete rectangles 44c, 44d is rotated counterclockwise along the fold 36. This step essentially narrows the width of the shirt 33 to make it suitable for packaging or storage, as the case may be, as seen in FIG. 17.
Step four of the shirt folding procedure is achieved in FIG. 18 and is accomplished by a clockwise rotation about the fold 38 by a section of the form 30 which includes the complete rectangles 44a, 44b. After the form 30 is returned to its original state as in FIG. 19 the left hand portion of the shirt 33 is folded to further reduce its width dimension.
The fifth folding step is as shown in FIG. 20 and results from a counterclockwise rotation of a section of form 30, as viewed in the left side of the drawing, about the fold 40 where the rotated section includes the rectangles 44b, 44d and 44f. The completely folded shirt 33 is depicted in FIG. 21 in a right side down position when the counter-rotated section is returned to its original state. FIG. 22 represents the completely folded shirt 33 in a right side up position and ready for packaging or storage as in a bureau or shelf, for example.
The embodiment of the invention illustrated in FIGS. 10-22 is particularly suitable for commercial use since an operator can fold a dress shirt in a period of time that is less than ten seconds. The folding procedure may be slightly longer when straight pins are used as in the practice when shirts are being retailed in a department store.
This invention has been described by reference to precise embodiments but it will be appreciated by those skilled in the art that this invention is subject to various modifications and to the extent that those modifications would be obvious to one of ordinary skill they are considered as being within the scope of the appended claims. | A device for facilitating the folding of apparel such as shirts or sweaters and the like. This device consists essentially of a flat base having a plurality of creases that allow the operator to manipulate the shirt or sweater in vertical and horizontal stages so as to achieve complete and proper folding in a uniform and attractive manner. The device has universal appeal since it may be used both at home and in the commercial trade. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a content data providing system, a content data providing method, and a terminal unit, in particular, to those that use unique identification information post-scribed on a CD (Compact Disc) disc on which for example music data to recorded.
2. Description of the Related Art
As a portable digital audio reproducing unit has become common, an environment of which each user can enjoy reproducing his or her favorite music anytime and anywhere has been almost accomplished. In addition, as music distribution systems using the Internet and cellular phones have come out, each user can easily buy music data. On the other hand, as such music distribution systems using the Internet and cellular phones have come out, it is apprehensive that copyright of music data will be infringed and sales of CDs will be decreased.
In other words, a portable digital audio reproducing unit that comprises a semiconductor memory that stores music data compressed according to MP3 (MPEG Audio Layer-3). ATRAC (Adaptive TRansform Acoustic Coding) 3, or the like and a decoder that reproduces music data from the semiconductor memory has become common. With such an apparatus, the user can enjoy reproducing music on every occasion for example in a vehicle, during a walk, or on a trip. Such a portable digital audio reproducing unit is called silicon audio. Since such an apparatus has advantages of small size, light weight, low power consumption, shock resistance, and easy operation because it does not use a disc.
In addition, a portable palm top computer called PDA (Personal Digital Assistance) has been used as a portable digital audio reproducing unit. Moreover, a music distribution service using cellular phones has started.
In the music distribution service using cellular phones, user's favorite music data is downloaded through a line for cellular phones and stored in a semiconductor memory of user's cellular phone. With the music distribution service using cellular phones, each user can enjoy reproducing his or her favorite music anytime and anywhere an with a portable digital audio reproducing unit.
When the user stores music data in the portable digital audio reproducing unit, he or she have to cause a personal computer to capture music data reproduced from the CD and compress the reproduced music data according to MP3 or the like. Thereafter, the user has to store a file of the compressed music data to a memory of the digital audio reproducing unit. That method has a benefit of which the user can effectively use the resource of the CD that he or she owns and store his or her favorite music to the portable digital audio reproducing unit.
However, in the method for storing music data reproduced from a CD to a portable digital audio reproducing unit, it is clear that music data that is recorded on the CD is copied. Thus, it is apprehensive that copyright of music cannot be protected.
Thus, although the portable digital audio reproducing unit is convenient because the user can reproduce music anytime and anywhere therewith, it is apprehensive that a problem about copyright of the source of music data will arise. Ideally, it is desired to protect music data of a CD from being copied. However, in the case, the user who has bought the CD will suffer a disadvantage.
Now, it is assumed that one user has bought his or her favorite CD album with payment and that he or she wants to enjoy music pieces of the CD album with a portable digital audio reproducing unit.
In that case, even if the user has bought the CD album, unless he or she can copy music data of the CD album to the portable digital audio reproducing unit, he or she cannot enjoy reproducing the music data with the portable digital audio reproducing unit.
When the same music data as music pieces of a CD album is provided as a music distribution service, the user can download the music data from the music distribution service, store the downloaded music data to the portable digital audio reproducing unit, and enjoy reproducing the music data with the portable digital audio reproducing unit. However, at the prevent time, with a fear that the sales of CDs will decrease, many music distribution services do not provide music pieces of latest albums.
In other words, as long as the user can use a network environment, since he or she can buy his or her favorite music data anytime and anywhere with the music distribution service, it is no doubt to may that the music distribution service provides him and her with high convenience. However, when the music distribution service provides the user with music data of latest albums, it is expected that he or she will buy it with the music distribution service, copy the music data, and enjoy reproducing it. AS a result, it Is apprehensive that the sales of the CDs will decrease. Thus, at the present time, latest albums that are expected to be sold a lot are normally sold as CDs, not provided with the music distribution service.
Even if the user can buy music data of his or her favorite album with the music distribution service, he or she should buy the same music data as that of the CD album, which he or she has bought, once again with the music distribution service. That means that the user has bought the same music data with double payment. Thus, the user will suffer at large loss.
Thus, when music data is completely protected from being copied, even if the user has bought a CD that he or she wants to listen without an intention to infringe copyright thereof, he or she cannot enjoy reproducing the music pieces with the portable digital audio reproducing unit. Alternatively, the user should buy the same music data twice as a disadvantage.
In addition, as was described above, at the present time, the music distribution service does not provide popular music such as latest albums with a fear of the decrease of sales of CDs. Although it is clear that the music distribution service is very convenient, unless it provides popular music such as latest albums, the music distribution service will not grow. That fact becomes one factor that prevents the music distribution service from growing.
From the forgoing point of view, it is desired to provide the user who has bought a CD with an environment that does not cause him or her to buy the same content data twice and that allows him or her to enjoy reproducing the content data, which he or she has bought, anytime and anywhere and the copyright owner with an environment that occasions of copies of CDs will decrease so as to prevent copyright from being infringed and that music data that the music distribution service provides does not affect the sales of CDs. As a result, it is desired to promote a sound growth of the music distribution service.
OBJECTS AND SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide a content data providing system, a content data providing method, and a terminal unit that do not cause the user who has bought content data with a recording medium such as a CD to suffer from a disadvantage and allow him or her to reproduce the content data, which he or she has bought, anytime and anywhere.
Another object of the present invention is to provide a content data providing system, content data providing method, and a terminal unit that allow the copyright owner to have an environment of which occasion of copies of CDs will decrease so as to prevent copyright from being infringed and music data that the music distribution service provides does not affect the sales of CDs and that allow the music distribution service to soundly grow.
To solve the forgoing problem, a first aspect of the present invention is a content data providing server connected to a terminal unit of a user and a terminal unit of a recording medium producer through a network, the content data server having: a management server for receiving unique identification information of a recording medium, the unique identification information being post-scribed by the producer, unique identification information of a recording medium that the user has bought, personal information of the user, and identification information of the terminal unit of the user, creating a list that represents the relation between those information and identification information of content data of the recording medium that the user owns, and storing the list; a content server for storing content data corresponding to the identification information of the content data, the identification information being contained in the list; and a content distribution server for distributing content data stored in the content server to the terminal unit of the user corresponding to a distribution request that the terminal unit of the user has issued, wherein when the user who has issued the distribution request and the unique identification information of the recording medium corresponding to the distribution request are contained in the list, the content data corresponding to the unique identification information is permitted to be distributed.
A second aspect of the present invention is a content data providing system connected to a content providing server, a terminal unit of a recording medium producer, and a terminal unit of a user through a network, wherein the terminal unit of the user is configured to register personal information of the user to the content providing server and transmit unique identification information of a recording medium that the user has bought, wherein the content providing server has: a management server for receiving unique recording medium identification information of a recording medium, the unique identification information being post-scribed by the recoding medium producer, the unique identification information of the recording medium that the user has bought, the personal information of the user, and identification information of the terminal unit of the user, creating a list that represents the relation between those information and identification information of content data of the recording medium that the user owns, and storing the list; a content server for storing content data corresponding to the identification information of the content data, the identification information being contained in the list; and a content distribution server for distributing content data stored in the content server to the terminal unit of the user corresponding to a distribution request that the terminal unit of the user has issued, wherein when the user who has issued the distribution request and the unique identification information of the recording medium corresponding to the distribution request are contained in the list, the content data corresponding to the unique identification information is permitted to be distributed.
A third aspect of the present invention is a content data providing method for a system connected to a content providing server, a terminal unit of a recording medium producer, and a terminal unit of a user through a network, the content providing method having the steps of: causing the terminal unit of the user to register the user to the content providing server and transmit unique identification information of a recording medium that the user has bought; causing the terminal unit of the user to register personal information of the user to the content providing server and transmit the unique identification information of the recording medium that the user has bought to the content providing server; causing the content providing server to receive unique identification information of a recording medium, the unique identification information being post-scribed by the recoding medium producer, the unique identification information of the recording medium that the user has bought, the personal information of the user, and identification information of the terminal unit of the user, create a list that represents the relation between those information and identification information of content data of the recording medium that the user owns, and store the list; and permitting the content providing server to distribute the content data corresponding to the unique identification information when the user who has issued the distribution request and the unique identification information of the recording medium corresponding to the distribution request are contained in the list.
A fourth aspect of the present invention is a terminal unit for requesting a content providing server to distribute content data, the content providing server being configured to receive unique identification information of a recording medium, the unique identification information being post-scribed by the recoding medium producer, unique identification information of a recording medium that the user has bought, personal information of the user, and identification information of the terminal unit, create a list that represents the relation between those information and identification information of content data of the recording medium that the user owns, and store the list, the terminal unit comprising: means for transmitting the identification information of the terminal unit to the content providing server so as to request it to distribute the content data; means for receiving the list corresponding to the identification information of the terminal unit or a part thereof from the content providing server and displaying the list when the user who has issued the distribution request and the unique Identification information of the recording medium corresponding to the distribution request are contained in the list; and means for selecting a content that the user wants the content providing server to distribute from the list or a part thereof, receiving the selected content data from the content providing server, and reproducing or storing the received content data.
When content data (music data) is recorded on each recording medium such as a CD disc, unique disc identification information (UDI) is post-scribed to the recording medium. A management server (ID management server), a content server (music piece server), and a content distribution server (music distribution server) are disposed. The management server (ID management server) manages content data recorded on the recording medium corresponding to the unique disc identification information post-scribed on the recording medium. The content server (music piece server) stores content data recorded on the recording medium. The content distribution server (music distribution server) reads content data from the content server corresponding to a distribution request issued from a terminal unit (portable digital audio reproducing unit) and distributes the content data to the terminal unit (portable digital audio reproducing unit) that has issued the distribution request.
When the end user has bought a recording medium, he or she performs a registration process for the recording medium with a user terminal (personal computer) through a network. In addition, the end user sends identification information to a management server of a content provider. With the identification information, a list that represents music pieces that each user owns is created. Corresponding to the list, music pieces that each user owns can be permitted to be reproduced or downloaded free of charge or at low price.
When the end user has bought a CD and registered as the user, he or she is provided with a music distribution service with priority. Thus, when the end user uses the portable digital audio reproducing unit, he or she does not need to copy the music data from the CD disc. In addition, the end user does not need to buy the same music data as the CD disc that he or she has bought.
In addition, the content provider side can expect that opportunities that users who have bought CDs will copy music data of the CDs will decrease. Thus, according to the present invention, copyright of music data can be easily protected. In addition, without necessity to copy music data from a CD disc to a portable digital audio reproducing unit, since the end user can obtain the music data through the music distribution service, it can be predicted that the sales of CDs are not affected (not decreased).
In addition, since sales of CDs are linked with a music distribution service, it can be predicted that contents providers will actively provide their music pieces through the music distribution service. Thus, it can be expected that the music distribution service will grow.
These and other objects, features and advantages of the present invention will become more apparent in light of the following detailed description of a best mode embodiment thereof, as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing an example of a system according to the present invention;
FIG. 2 is a sectional view for describing disc identification information that is recorded;
FIG. 3 is a flow chart for describing disc identification information that is recorded;
FIG. 4 is a schematic diagram for describing identification information that is recorded;
FIG. 5 is a flow chart for describing a member registration process;
FIG. 6 is a flow chart for describing a registration process performed when a disc is bought;
FIG. 7 is a schematic diagram showing a data structure of an example of a customer and owning music piece list;
FIG. 8 is a flow chart for describing a distribution process;
FIG. 9 is a plan view showing an example of a PDA used as a portable digital audio apparatus;
FIG. 10 is a block diagram showing a structure of an example of a PDA used as a portable digital audio apparatus; and
FIG. 11 is a block diagram showing another example of a system according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Next, with reference to the accompanying drawings, an embodiment of the present invention will be described. FIG. 1 shows an example of a system according to the present invention. In the system, a music company 11 requests a disc plant 21 to produce a disc on which music data is recorded. The disc plant 21 produces a disc 25 . The disc plant 21 sells the disc 25 to an end user 31 . When the end user 31 who has bought the disc 25 registers as a user of the disc 25 , the end user can receive a music distribution service for the music pieces as the owner thereof from a music distribution server with priority.
In the example, the disc 25 is a CD disc used as a recording medium. In the example, on each disc, unique disc identification information (UDI) can be post-scribed. The unique disc identification information (UDI) is information with which each disc is identified. The unique disc identification information (UDI) contains for example a disc producer name, a disc seller name, a production plant name, a production year, a serial number, and time information. In addition, the unique disc identification information (UDI) contains various types of information. The unique disc identification information (UDI) is recorded so that it can be read by a conventional CD player or a conventional CD-ROM drive.
With the disc 25 on which the unique disc is identification information (UDI) has been post-scribed, the music company 11 can know CDs that each user owns. Thus, the music company 11 can provide the end user 31 who has bought a CD with the music distribution service with priority. Before the description of the system shown in FIG. 1 , a disc on which unique disc identification information (UDI) can be post-scribed will be described.
First of all, for easy understanding, the structure of a conventional optical disc for example a CD will be described.
FIG. 2 is an enlarged view of a part of a conventional CD. Concave portions called pits and lands on which pits are not formed are alternately formed on each track whose track pitch is Tp (for example. 1.6 μm). The length of each of one pit and one land is in the range from 3T to 11T, where T is the shortest inversion period. A laser beam is radiated from a disc substrate side of the CD.
When the CD is viewed from the bottom side to which the laser beam to radiated, a transparent disc substrate 1 , a reflection film 2 , and a protection film 3 are successively disposed. The transparent disc substrate 1 has a thickness of 1.2 mm. The reflection film 2 is formed on the transparent disc substrate 1 . The protection film 3 is formed on the reflection film 2 . The reflection film 2 is made of a material that has a high reflectance. Although the CD is a read only disc, as will be described later, after the reflection film 2 in formed, unique disc identification information (UDI) is post-scribed on the reflection film 2 with the laser beam.
Next, with reference to FIG. 3 , the flow of a CD production process will be described. At step S 1 , a glass substrate on which a photoresist as a photosensitive substance has been coated on a glass plate is rotated by a spindle motor. The laser beam that is turned on or off corresponding to a record signal is radiated on the photoresist film. As a result, a master is produced. The photoresist film is developed. When the photoresist film is a positive resist film, the exposed portion is etched and an etched pattern is formed on the photoresist film.
The photoresist substrate is plated. As a result, one metal master is produced (at step S 2 ). With one metal master, a plurality of mothers are produced (at step S 3 ). In addition, with one mother, a plurality of stampers are produced (at step S 4 ). With one stamper, disc substrates are produced by for example a compression molding method, an injection molding method, or a light setting method. At step S 6 , the reflection film and the protection film are coated. In the conventional disc producing method, a label is printed on the CD. As a result, the CD is produced as a final product.
On the other hand, in the example shown in FIG. 3 , the laser beam is radiated on the reflection film (mirror portion for example lands). In addition, information is post-scribed (at step S 7 ). On the lands of the reflection film, the laser beam is radiated. In other words, when a heat process (heat recording) is performed, since atoms are traveled, the film structure and crystal characteristic are varied. As a result, the reflectance of the place decreases. Thus, after the laser beam has been radiated to the lands, the return beam thereof decreases. Thus, the reading apparatus recognizes lands as pits. Using that phenomenon, when the pit length or land length are varied, information can be recorded. In that case, the reflection film is made of a material whose reflectance is varied with a laser radiation is used. When the laser beam is radiated to the reflection film, namely, information is recorded, the reflectance of the reflection film may be not only decreased, but increased depending on the material of the reflection film.
In reality, the reflection film is made of an aluminum alloy film Al 100-y X y , where X is at least one selected from the group consisting of Ge, Ti, Ni, Si, Tb, Fe, and Ag and where the composition ratio y in the Al alloy film satisfies the relation of 5<y<50 [atomic %].
In addition, the reflection film can be made of an Ag alloy film Ag 100-z Y z , where Y is at lest one selected from the group consisting of Ge, Ti, Ni, Si, Tb, Fe, and Al and where the composition ratio z in the Al ally film satisfies the relation of 5<z<50 [atomic %]. The reflection film can be formed by for example the magnetron spattering method.
As an example, assuming that the reflection film of an AlGe alloy is formed with a thickness of 50 nm and that a laser beam is radiated from the transparent substrate or the protection film side through an objective lens, that the composition rate of Ge is 20 [atomic %], and that the record power is in the range from 6 to 7 [mW], the reflectance decreases by around 6%. In those conditions, assuming that the composition ratio of Ge is 27.6 [atomic %] and that the record power is in the range from 5 to 8 [mW], the reflectance decreases by around 7 to 8%. Since the reflectance varies in such a manner, information can be post-scribed on the reflection film.
FIG. 4 is a schematic diagram for practically describing the method for post-scribing the unique disc identification information (UDI). There are two patterns A and B corresponding to the relation between record data and pits/lands.
First of all, the pattern A will be described. Three margining bits (000) are placed between two symbols. When information is post-scribed, an eight-bit data symbol is for example (0x47), where 0x represents hexadecimal notation. FIG. 4 shows a 14-bit pattern of which the eight bits have been modulated by the EFM (Eight to Fourteen Modulation) method.
A laser beam Is radiated to a hatched area between two pits so as to post-scribe information thereto. As a result, the reflectance of the hatched area decreases. After information has been recorded, the two pits are treated as one connected pit. In that case, the 14-bit pattern becomes (00100100000000). When the 14-bit pattern is EFM-demodulated, eight bits of (0x07) are obtained.
In the case of the pattern B, the margining bits are (001). In the case, like the pattern A, when a laser beam is radiated to a hatched area, eight bits can be changed from (0x47) to (0x07).
As was described above, a data symbol (0x47) can be rewritten to (0x07). Beside that example, there are many types of data that can be post-scribed. For example, a data symbol (0x40) can be changed to (0x00). However, when information is post-scribed, a laser beam is radiated to a mirror portion on which data has been recorded. As a result, the length of a pit or a land is varied. Thus, the types of data that can be post-scribed are restricted.
Returning to FIG. 1 , an example of a system according to the present invention will be described. The system uses the disc 25 on which such unique disc identification information (UDI) can be post-scribed.
In FIG. 1 , when an album CD disc or a single CD disc is produced, the music company 11 requests the disc plant 21 to produce the disc. A music source 12 created by an artist Is sent from the music company 11 to the disc plant 21 . The music source 12 is normally provided as a tape or a disc on which music data has been digitally or analogously recorded by the artist. The tape or disc is delivered from the music company 11 to the disc plant 21 . The format of the music source 12 and the method for sending the music source 12 from the music company 11 to the disc plant 21 are not limited. When the music company 11 requests the disc plant 21 to produce the disc, the music company 11 asks the disc plant 21 to post-scribe unique disc identification information (UDI) on the disc.
In addition, the music source 12 is sent to a music piece server 13 of the music company 11 (or software house). The music piece server 13 is a server of a library of music pieces of CDs that the music company 11 has released so far. The music piece server 13 stores music data of many music pieces whose copyright the music company 11 has and music pieces that the music company 11 has released so far. When the music source 12 is sent to the music piece server 13 , each piece of music data of the music source 12 is stored to the music piece server 13 . Music data of each music piece recorded on the disc 25 that will be released is added to the library. Various types of information 15 about the CD for example the song name and the artist name of each music piece contained as the music source 12 are sent to an ID management server 14 of the music company 11 (or the software house).
When the disc plant 21 has been requested to produce a CD disc by the music company 11 and has received the music source 12 , the disc plant 21 produces the CD disc on which the music data of the music source 12 is recorded. At that point, since the music company 11 has been requested by the disc plant 21 to post-scribe the unique disc identification information (UDI), the disc plant 21 records the unique disc identification information (UDI) on the disc.
In other words, when the disc plant 21 has been requested by the music company 11 to produce the CD disc and has received the music source 12 from the music company 11 , the disc plant 21 starts a disc production process 22 . In the disc production process 22 , the disc plant 21 produces a master disc on which music data of the music source 12 is recorded. The disc plant 21 produces a CD disc on which the music data of the music source 12 is recorded with the master disc through a stamper.
The disc production process 22 is followed by an ID write process 23 . In the ID write process 23 , the unique disc identification information (UDI) is post-scribed on each disc. The unique disc identification information (UDI) that is post-scribed on each disc is managed by an ID write control server 24 . The unique disc identification information (UDI) that has been recorded on each disc that has been produced that time is sent to the ID management server 14 of the music company 11 or the software house.
The disc production process 22 and the ID write process 23 are shown in FIG. 3 and FIG. 4 .
The disc 25 that has been produced through the disc production process 22 and the ID write process 23 is contained in a case and then wrapped as a final product through a wrapping process 26 . The disc 25 as the final product is delivered to the end user 31 . While the disc 25 is delivered to the end user 31 , there are several sales channels for example a channel from a music publisher to a CD retailer through a whole seller, a channel from a music publisher to a CD retailer, and a channel from a music publisher to the end user 31 as a direct sales channel. When a regular end user 31 buys a disc 25 , he or she will go to a CD retailer and buy the disc 25 with payment.
After the end user 31 has bought the disc 25 , he or she perform a registration operation for the disc. Unless the end user 31 has performed the member registration, he or she connects his or her personal computer 32 that has a network connecting function to for example the Internet to the ID management server 14 of the music company 11 so as to perform the member registration. Since the personal computer 32 has a CD drive, the personal computer 32 can reproduce music data and unique disc identification information (UDI) from the disc 25 . Of course, a conventional CD player can reproduce music data from the disc 25 .
FIG. 5 shows a member registration process. In FIG. 5 , when the disc 25 that the end user 31 has bought is loaded to the personal computer 32 of the end user 31 , a member registration program is started (at step S 11 ). When the member registration program is started, a member registration menu is displayed (at step S 12 ). At step S 12 , it is determined whether or not the end user 31 has registered as a member (at step S 13 ).
When the end user 31 has not been registered as a member, he or she inputs his or her personal information such as his or her name and address and unit identification information. As the personal information, the end user 31 may be requested to input user's birthday, sex, occupation, e-mail address, and store name he or she has bought the CD. Such information can be used as customer information to advertise now products and research the buying power of the customers. The unit identification information is unique identification information of the portable digital audio reproducing unit that receives the music distribution service. When the cellular phone terminal unit is used as a portable digital audio reproducing unit, the telephone number of the cellular phone can be used as unit identification information.
When the personal information is input, such as end user's name, address, unit identification information are sent from the personal computer 32 of the end user 31 to the ID management server 14 of the music company 11 (at step S 15 ). The personal computer 32 of the end user 31 and the ID management server 14 of the music company 11 are connected through for example the Internet. The member registration process is performed through an network such as the Internet.
After the ID management server 14 of the music company 11 has received the personal information from the end user 31 , the ID management server 14 determines whether or not the personal information has been fully described and whether or not the personal information has been dually registered. When the personal information that has been received from the personal computer 32 is proper, the ID management server 14 stores the personal information and issues a member number to the end user 31 . When the member number has been received by the personal computer 32 of the end user 31 (at step S 16 ), the member registration process is completed (at step S 17 ). Thereafter, the flow advances to the next step (at step S 18 ).
When the end user 31 who has registered as a member starts the member registration program, the flow advances to step S 13 . At step S 13 , it is determined that he or she has registered as a member. In that case, the end user 31 inputs his or her member number (at step S 19 ).
When the member number has been input, the member number is sent from the personal computer 32 of the end user 31 to the ID management server 14 of the music company 11 (at step S 20 ).
When the ID management server 14 of the music company 11 has received the member number, the ID management server 14 references the information of the end user whose has the member number and determines whether or not the end user has been regularly registered as a member. The ID management server 14 of the music company 11 sends the determined result to the personal computer 32 of the end user 31 .
Corresponding to the information sent back from the ID management server 14 of the music company 11 to the personal computer 32 of the end user 31 , it is determined whether or not the end user 31 has been regularly registered as a member (at step S 21 ). When the end user 31 has been regularly registered as a member, the flow advances to the next step (at step S 18 ). When the determined result represent that the end user 31 has not been regularly registered as a member, the process is repeated or terminated (at step S 22 ).
In FIG. 1 , when the end user 31 buys the disc 25 , if he or she has registered as a member, the registration process is performed at once through a network such as the Internet. At that point, if the end user 31 has not been registered as a member, after he or she registers as a member, he or she performs the registration process. In the registration process, unique disc identification information (UDI) is read from the disc 25 . The unique disc identification information (UDI) of the disc 25 is sent from the personal computer 32 of the end user 31 to the ID management server 14 of the music company 11 . Corresponding to the unique disc identification information (UDI) received from the ID write control server 24 , various types of information 15 about the CD that is created such as song names and artist names of music pieces of the music source 12 , and the personal information received from the personal computer 32 of the end user 31 when he or she has registered as a member, a customer and owning music piece list is created in the ID management server 14 of the music company 11 .
FIG. 6 is a flow chart showing the registration process for the disc 25 that the end user 31 has bought.
In FIG. 6 , when the registration program is started (at step S 31 ), unique disc identification information (UDI) is read from the disc 25 (at step S 32 ). After the unique disc identification information (UDI) has been read, the unique disc identification information (UDI) and the member number are sent from the personal computer 32 of the end user 31 to the ID management server 14 of the music company 11 (at step S 33 ).
The ID management server 14 of the music company 11 compares the unique disc identification information (UDI) received from the personal computer 32 of the end user 31 with identification information created corresponding to the identification information list received from the ID write control server 24 and checks the unique disc identification information (UDI) (at step S 34 ). At that point, it is determined whether or not the unique disc identification information (UDI) has been falsified and whether or not it has been dually registered. Corresponding to the checked result of the unique disc identification information (UDI), it is determined whether or not the unique disc identification Information (UDI) is a regularly registered number (at step S 35 ).
When the determined result represents that the unique disc identification information (UDI) received from the personal computer 32 of the end user 31 is a regularly registered number, the relevant information is registered to the ID management server 14 of the music company 11 (at step S 36 ).
When the determined result represents that the unique disc identification information (UDI) is not a regularly registered number, the relevant information Is sent from the ID management server 14 of the music company 11 to the personal computer 32 of the end user 31 . A message “not regularly registered user” is disposed on the display of the personal computer 32 of the end user 31 (at step S 37 ). Thereafter, the process is terminated (at step S 38 ).
When the end user 31 buys the disc 25 , the registration process is performed in such a manner. In the registration process, the unique disc identification information (UDI) is read from the disc 25 . As shown in FIG. 7 , a customer and owning music piece list is created.
As shown in FIG. 7 , the customer and owning music piece list describes the name of users who have bought CDs, member numbers, CD identification information, single/album information, artist names, titles, song names, and unit identification information. With the customer and owning music piece list, music pieces that each user owns are obtained.
The name of user who has bought the CD, member number, and unit identification information such as cellular phone number are described when the personal computer 32 is connected to the ID management server 14 and the end user 31 is registered as a member to the ID management server 14 . The CD identification information is described corresponding to the unique disc identification information (UDI) that is read from the disc 25 when the end user 31 loads the disc 25 to the personal computer 32 and connects the personal computer 32 to the ID management server 14 . The single/album information, artist name, title, and music piece name are described corresponding to various types of information 15 about the CD that is produced.
In FIG. 1 , the music company 11 has a music distribution server 16 . The music distribution server 16 performs a music distribution service through the Internet and a cellular phone line. The music distribution server 16 provides music data of music pieces stored in the music piece server 13 . The music distribution server 16 references the customer and owning music piece list (see FIG. 7 ) stored in the ID management server 14 and provides a user who has bought a CD with the music distribution service with priority.
For example, as shown in FIG. 7 , it is assumed that an end user 31 whose member number is “9012” and who is “ICHIRO SUZUKI” has bought a CD disc 25 whose unique disc identification information is “1234567”. When the end user 31 , who is “ICHIRO SUZUKI”, loads the disc 25 to the personal computer 32 and connects the personal computer 32 to the ID management server 14 of the music company 11 , the unique disc identification information (UDI) is read from the disc 25 . The unique disc identification information (UDI) is sent from the personal computer 32 of the end user 31 to the ID management server 14 . The unique disc Identification information (UDI) “1234567” is described as CD identification information, the single/album information, artist name “ICHIRO SATO”, title “SPRING AND SUMMER”, music piece name “FIRST WIND IN SPRING” are described corresponding to various types of information 15 about the CD that is produced. When the member registration is performed, as the unit identification information, the cellular phone number “0904578954” is described.
Thus, when the end user 31 who is “ICHIRO SUZUKI” has registered as a member and the unique disc identification information (UDI) of the disc 25 that he had bought has been sent to the ID management server 14 of the music company 11 , the unique disc identification information (UDI) is registered to the customer and is owning music piece list. At a result, the end user 31 who is “ICHIRO SUZUKI” can be provide with the music distribution service for the music piece that he or she owns with priority. In that case, when the end user 31 whose is “ICHIRO SUZUKI” accesses the music distribution server 16 with the cellular phone with the telephone number “0904578954”, the end user 31 is permitted to reproduce the music pieces “FIRST WIND IN SPRING” and “FIRST WIND IN SUMMER” of the disc title “SPRING AND SUMMER”. Alternatively, when the music distribution service is performed for music data that is downloaded or reproduced as streaming data, the user is provided with it free of charge or at low price.
FIG. 8 is a flow chart showing a process for receiving a music distribution service using a portable digital audio reproducing unit 33 . In FIG. 8 , a music reproduction program is started (at step S 41 ). With the portable digital audio reproducing unit 33 , a member number and unit identification information are sent to the music distribution server 16 of the music company 11 (at step S 42 ). The member number and the unit identification information can be automatically sent using a memory function. When a cellular phone is used as a portable digital audio reproducing unit, the unit identification information can be obtained with the sender telephone number.
When the music distribution server 16 has received information of the member number and the unit identification information from the portable digital audio reproducing unit 33 of the end user 31 , the music distribution server 16 asks the ID management server 14 for the member number and the unit identification information (at step S 43 ). Corresponding to the obtained information, the music distribution server 16 determines whether or not the member number and the unit identification information have been regularly registered as a member number and unit identification information (at step S 44 ). When the determined result represents that the member number and the unit identification information have not been regularly registered, the relevant information is sent back from the music distribution server 16 to the portable digital audio reproducing unit 33 of the end user 31 . A message “not regularly registered number” is displayed on the display of the portable digital audio reproducing unit 33 (at step S 45 ). Thereafter, the process is terminated (at step S 46 ).
When the determined result represents that the received member number and unit identification information have been regularly registered, with reference to information stored in the ID management server 14 , a list of music pieces that the user owns is created. In other words, with reference to the customer and owning music piece list shown in FIG. 7 , a list of music pieces of the CD that the user has bought and registered is created (at step S 47 ). The list of the music pieces that the user owns in sent from the music distribution server 16 to the portable digital audio reproducing unit 33 of the end user 31 . The portable digital audio reproducing unit 33 displays the list of music pieces that the user owns (at step S 48 ).
The end user 31 selects music pieces that he or she wants to be distributed from the menu list (at step S 49 ). The list of the selected music pieces is sent from the portable digital audio reproducing unit 33 to the music distribution server 16 (at step S 50 ).
When the music distribution server 16 has received the list of the selected music pieces from the portable digital audio reproducing unit 33 of the end user 31 (at step S 51 ), the music distribution server 16 accesses the music piece server 13 and obtains music data of the selected music pieces therefrom (at step S 52 ). The music data of the selected music pieces is distributed from the music piece server 13 to the portable digital audio reproducing unit 33 of the end user 31 through the music distribution server 16 (at step S 53 ).
When the portable digital audio reproducing unit 33 of the end user 31 has received the music data from the music distribution server 16 , the portable digital audio reproducing unit 33 reproduces the music data or stores it to a memory (at step S 54 ). In other words, when music data is distributed as steaming data, while it is being received, it is reproduced. When music data is downloaded, it is stored in the memory. The streaming is one distribution method of which while music data is being received, it is reproduced. The downloading is another distribution method of which music data is compressed according to MP3 or ATRAC3 and transmitted as a file.
FIG. 9 shows an example of the portable digital audio reproducing unit according to the present invention. In the example, a PDA is used as the portable digital audio reproducing unit.
As shown in FIG. 9 , at the front of a unit 61 , a liquid crystal panel 62 having a touch panel is disposed. By tapping an icon displayed on the liquid crystal panel 62 with a stylus pen (not shown), the user can input various types of data. By tracing letters on the liquid crystal panel 62 with the stylus pen, the user can input manuscript letters.
Below the liquid crystal panel 62 , buttons 63 , 63 , 63 , . . . are disposed. The buttons 63 , 63 , 63 , . . . are a power switch, icon buttons, and up and down scroll buttons. The icon buttons are linked with application software. When an icon button is pressed, a designated application is started.
An extension slot 64 is disposed at a top portion of the unit 61 . In the extension slot 64 , an extension module can be attached. There are extension modules that are an extension memory, a camera extension module, a GPS extension module, and so forth. The unit 61 has an infrared ray interface 66 and a USB interface 67 .
FIG. 10 shows an internal structure of the unit 61 . In FIG. 10 , a CPU core 71 is a processor in which a memory management portion, an I/O controller, and so forth are integrated. A bus 72 extends from the CPU core 71 . The liquid crystal panel 62 with the touch panel, the USB interface 67 , the infrared ray interface 66 , the extension slot 64 , the buttons 63 , and a non-volatile memory 73 are connected to the bus 72 . An MP3 or ATRAC3 decoder 74 is connected to the bus 72 . The decoder 74 can decode data that has been encoded according to MP3 or ATRAC3. The decoded data is converted into an analog signal and output from a head set 75 .
The USB interface 67 is mainly used to exchange data with a personal computer. When the unit 61 is placed on a cradle (not shown) and then a button (not shown) on the cradle is pressed, the unit 61 starts communicating with the personal computer and exchanges data therebetween.
A communication module can be connected to the USB interface 67 . When the communication module is connected to the USB interface 67 , the apparatus 61 can be accessed to the Internet. The infrared ray interface 66 is used to exchange data between those units and between the unit and a cellular phone terminal unit.
The unit 61 can access the Internet with the USB Interface 67 and make a connection to the music distribution server 16 . When the unit 61 is initially set, unique unit identification information as a user ID is recorded to the non-volatile memory 73 . In addition, application software for accessing the Internet and application software for decoding encoded music data according to MP3 or ATRAC3 data have been installed in the unit 61 .
When the unit 61 as the portable digital audio reproducing unit 33 is connected to the music distribution server 16 through the Internet, the user ID and the member number of the unit 61 are sent to the music distribution server 16 . When the music distribution server 16 has determined that the member number and the unit identification information are those that have been regularly registered, a list of music pieces that the user owns is displayed on the liquid crystal panel 62 . When the user selects a music piece that he or she wants to obtain from the list, music data of the selected music piece is sent from the music distribution server 16 to the unit 61 . The received music data is stored in the memory 73 (or an external memory). The decoder 74 starts the application software for decoding encoded music data according to MP3 or ATRAC3 and decodes the music data stored in the memory 73 on the application software. The decoded data is converted into an analog signal and output from the head set 75 .
As was described above, in that example, with a CD disc 25 on which unique disc identification information (UDI) has been post-scribed, the user thereof can be identified. Music pieces that each user owns are managed. A user who owns a music piece can be provided with a music distribution service for the music piece with priority.
In the forgoing example, it is preferred that the server side should distinguish unique disc identification information (UDI) for rental CDs that rental stores rent from unique disc identification Information (UDI) for other CDs. In that case, since rental CDs can be properly managed, copyright thereof can be protected.
In the forgoing example, a CD disc is used as a recording medium. However, the present invention can be applied to other recoding mediums. For example, unique disc identification information (UDI) can be post scribed in some card type recording mediums using flash memories. However, as long as the unique disc identification information (UDI) can be read by a personal computer, the forgoing system can be structured.
In the forgoing example, music data is reproduced. However, the same system can be applied to a DVD (Digital Versatile Disc) for video data such as movies. In addition, content data may be music data, video data of movies, and programs for reproducing video games.
The content provider side can provide a customer who has bought a recording medium on which a content had been regularly recorded with various levels of services. For example, it is assumed that a content provider permits a user who has bought a recording medium to transfer the ownership thereof to another person. At that point, when the user accesses the registration site and deletes his content from the list, he or she can transfer the ownership thereof to another person. The transferee can perform the user registration process in the same manner as above.
FIG. 11 shows another example of the present invention. In the forgoing example of the system, unique disc identification information (UDI) can be post-scribed to each disc. However, in this example, a conventional CD disc is used.
In FIG. 11 , when an album or single CD disc is produced, a music company 111 requests a disc factory 121 to produce the CD disc. A music source 112 created by an artist is sent from the music company 111 to the disc factory 121 . The music source 112 is provided as an analogously or digitally recorded tape or disc by the artist. The tape or disc is sent from the music company 111 to the disc factory 121 .
The music source 112 is sent to a music piece server 113 . The music piece server 113 is a server as a library of music pieces of CDs that the music company 111 has released so far. When the music source 112 is sent to the music piece server 113 , music data of each piece of the music source 112 is stored in the music piece server 113 . Music data of music pieces of a CD that the music company 111 will release this time is added to the library. In addition, various types of information about the CD such as the song name and artist name of each music piece contained in the music source 112 are sent to an ID management server 114 of the music source 112 .
When the disc factory 121 has been requested by the music company 111 to produce a CD disc for the music source 112 and has received the music source 112 , the disc factory 121 produces a CD disc on which music data of the music source 112 is recorded. In other words, when the disc factory 121 has been requested by the music company 111 to produce a CD disc 125 and received the music source 112 , a disc production process 122 is started. In the disc production process 122 , a master disc on which the music data of the music source 112 has been recorded is produced. With the master disc, CD discs 125 on which the music data of the music source 112 has been recorded are quantitatively produced through a stamper.
The discs produced in such a manner are contained in CD cases and wrapped as final produces through a wrapping process 126 . In the wrapping process, disc identification information is printed on the front surface of each disc or a song card or another paper wrapped with the disc. The disc identification information is managed by an ID write control server 124 . In addition, disc identification information recorded on each disc that has been produced this time is sent to the ID management server 114 of the music company or software house. A disc as a final produce is contained in a CD case, wrapped through the wrapping process 126 , and delivered to an end user 131 .
When the end user 131 has bought the CD disc 125 , he or she performs a registration process for the CD disc 125 . Unless the end user 131 has registered as a member, he or she registers as a member before registering the CD disc. When the end user 131 registers as a member, personal information such as the name, address, telephone number, and e-mail address of the user is sent from a personal computer 132 of the and user 131 to the ID management server 114 of the music company 111 .
After the end user 131 has bought the CD disc 125 , he or she inputs the disc identification information with the personal computer 132 having a network connecting function using for example the Internet so an to perform the disc registration process.
In other words, disc identification information is printed on the front surface of each disc 125 or a song card or another paper wrapped with the disc. When the end user 131 performs the disc registration process, he or she inputs the disc identification information. The disc identification information is sent from the personal computer 132 of the end user 131 to the ID management server 114 of the music company 111 through a network such as the Internet.
The ID management server 114 of the music company 111 creates a customer and owning music piece list corresponding to the identification information received from the ID write control server 124 , various types of information 115 about the CD that is produced such as the song name, artist name, and so forth of each music piece contained as the music source 112 , the disc personal information received from the personal computer 132 when end user 131 has registered as a member, and the disc identification information.
The customer and owning music piece list contains the user name, member number, CD identification information, single/album information, artist name, title, song name, and unit identification information.
In addition, the music company 111 has a music distribution server 116 . The music distribution server 116 performs the music distribution service using a portable digital audio reproducing unit 133 through the Internet or a cellular phone line. The music distribution server 116 can provide music data of music pieces stored in the music piece server 113 . The music distribution server 116 references the customer and owning music piece list stored in the ID management server 114 and provides the user who has bought the CD with the music distribution service with priority.
As described above, in that example, with disc identification information printed on each disc or paper wrapped with the disc, music pieces of the CD disc that each use has bought are managed. The other structure of the second example of the system is the same as that of the first example of which unique disc Identification information (UDI) is post-scribed for each disc.
As was described above, according to the present invention, unique disc Identification information (UDI) is post-scribed on each CD disc on which for example music data has been recorded. After the end user has bought a disc, he or she performs a disc registration process and sends an identification number of the disc to a management server of a content provider through a network such as the Internet. With the unique disc identification information, a list representing music pieces that each user owns is created. Corresponding to the list, each user is permitted to reproduce music pieces that he or she owns and download them free of charge or at low price.
Thus, when the and user has bought a CD, he or she is provided with a music distribution service for music data of the CD with priority. Thus, the user can not only reproduce music data from the CD at home, but download the same music data from the content server to his or her portable digital audio reproducing unit using the music distribution service and reproduce the downloaded music data with the unit anytime and anywhere. Thus, when the end user uses the portable digital audio reproducing unit, he or she does not need to copy the music data from the CD disc. In addition, the end user does not need to buy the same music data as the CD disc that he or she has bought.
In addition, the content provider side can expect that opportunities that users who have bought CDs will copy music data of the CDs will decrease. Thus, according to the present invention, copyright of music data can be easily protected. In addition, without necessity to copy music data from a CD disc to a portable digital audio reproducing unit, since the end user can obtain the music data through the music distribution service, it can be predicted that the sales of CDs are not affected (not decreased).
In addition, since sales of CDs are linked with a music distribution service, it can be predicted that contents providers will actively provide their music pieces through the music distribution service. Thus, it can be expected that the music distribution service will grow.
Although the present invention has been shown and described with respect to a best mode embodiment thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omissions, and additions in the form and detail thereof may be made therein without departing from the spirit and scope of the present invention. | A server includes a memory that stores unique identification information of an optical disc that stores at least one content data. The server also includes a receiver that receives user account information and the unique identification information from a user terminal. A processor performs an authentication of the user terminal for a transfer of the at least one content data based on a reception by the server of the unique identification information and the user account information from the user terminal. Further, the processor associates the user account information with the unique identification information upon a determination that the unique identification information has not previously been registered by the server based on the reception of the user account information and the unique identification information. A transmitter sends an authentication result to authorize the transfer of the at least one content data, in response to the authentication of the user terminal. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
This is a Divisional application of Ser. No. 09/109,312, filed Jun. 30, 1998 now U.S. Pat. No. 6,308,890 which itself is a Divisional application of application Ser. No. 08/802,672 filed Feb. 19, 1997, now U.S. Pat. No. 5,834,747, which itself was a Continuation of application Ser. No. 08/334,474, filed Nov. 4, 1994 (now abandoned).
BACKGROUND OF THE INVENTION
The invention relates to the use of devices having information or patterns carried in or on some storage media, examples of which include photographic patterns, keys or the magnetic strip on credit cards. The invention provides for an apparatus and method allowing more than one pattern or set of information to be used with a given type of medium to facilitate use by the holder thereof with a pattern reading device and to reduce the numbers of separate information or pattern media carrying devices which must be used. Other uses and purposes for the present invention will also become known to one skilled in the art from the teachings herein.
1. Field of the Invention
The field of the invention includes the storage and use of information or patterns on or in operator usable medium, examples including credit cards, keys, holograms, photographs and the like, by use of various magnetic, electronic, optical and mechanical devices. Such information or patterns may be known, unknown, ordered or random, coherent or incoherent, there being no restriction on the types or nature of information or patterns with which the invention may be used. The operators may be human, animal or otherwise, and may involve different operators of different persons or types at various times.
2. Description of the Prior Art
It is well known to store particular information or patterns such as account numbers, bar codes, security codes, etc. on magnetic and optical storage medium embedded in small, sturdy and relatively inexpensive carriers such as credit cards. FIG. 1 shows for example a prior art credit card diagram having a strip of magnetic material 2 which is embedded in a plastic substrate 1 which magnetic strip carries a pattern of magnetization which is a magnetic representation of information or patterns relating to the credit card. FIG. 1 is shown in graphical form with the top and front edge view of the magnetic strip with a representation of the magnetic flux pattern recorded therein.
OBJECTS AND DISCLOSURE OF THE INVENTION
The invention described herein provides for a method and apparatus whereby a plurality of sets of patterns or information may be stored and utilized by a user. The invention allows access to numerous accounts, services, features, etc. with just one storage device, thereby eliminating the need to carry, store, remember or retain numerous data storage devices, data sets or patterns. Examples of applications for the present invention include the magnetic pattern information of a plurality of credit cards which may be stored in a single convenient card which a user may carry in order to replace a plurality of individual credit cards, programmable optical patterns such as bar codes or photographic patterns utilized for security applications and programmable key patterns which may be changed to accommodate different locks of mechanical, optical or electronic type.
The invention is useful with any sort of storage medium related to pluralities of sets of information, data or patterns which are desired to be used by a user. For example the invention may be used with mechanical, magnetic, electrical, optical, film, holographic or other recording or storage of information or patterns as will become apparent to one skilled in the art from the teachings given herein. The invention thus provides simulation of multiple sets of data, information or patterns stored in a spatial pattern by providing a memory or storage device for storing data from which the spatial patterns may be reconstructed. Also included is a programmable spatial device capable of reconstructing the spatial patterns under control of a circuit responsive to an external inputs which cause the programmable spatial device to be programmed to reconstruct the spatial patterns from the data stored in the memory. The spatial patterns may take on multiple dimensions and may be time varying and the memory may be electronic, mechanical, optical or other type as will be apparent to one of ordinary skill in the art from the teachings herein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a drawing demonstrating a prior art credit card with a magnetic stripe.
FIG. 2 is a drawing demonstrating the preferred embodiment of the present invention.
FIG. 3 is a drawing explaining the operation of the preferred embodiment of the invention.
FIG. 4 is a drawing showing details of the programmable magnetic strip of the preferred embodiment of the invention.
FIG. 5 is a drawing showing a cross sectional view corresponding to FIG. 4 .
FIG. 6 is a drawing showing the invention as used with a key.
FIG. 7 is a drawing showing another mechanical configuration of the preferred embodiment of FIG. 2 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a drawing demonstrating a prior art credit card in diagram form, having a strip of magnetic material 2 which is embedded in a plastic substrate 1 which magnetic strip carries a pattern of magnetization which is a magnetic representation of information or patterns relating to the credit card. FIG. 1 shown in graphical form the top and front edge view of the magnetic strip with a representation of the magnetic flux recorded therein.
FIG. 2 shows a diagram of the preferred embodiment of the present invention, dubbed a multi-card by the inventor, having a plastic substrate 3 , on which is suitably mounted a programmable magnetic strip 4 , an LCD display 5 , a solar cell power source 6 , including an electricity storage cell (not shown), an infrared emitter 7 , and infrared sensor 8 , and a key pad 9 consisting of 14 operator actuated switches. It will be appreciated that these switches may be capacitive type touch sensitive sensors or other types. It will be understood that the programmable magnetic strip 4 may also be of a type which may sense magnetic information or patterns, and thus may be used as an input or output device.
Programmable magnetic strip 4 is preferred to be operated to approximate, duplicate or replicate a magnetic pattern matching the particular need of the operator in response to the operator's commands or inputs to the card as will be described in more detail below.
In operation, the multi-card has stored in it several sets of data corresponding to account related information or patterns for different credit cards, identification cards and the like. Power for the operation of the device is provided by a solar cell, which power is stored in a storage battery. The battery is preferred to be replaceable with a charged battery for those applications where the solar cell does not receive enough light to operate the multi-card, however it is preferred that devices which make use of the multi-card provide sufficient illumination to the solar cell to power the device.
To operate the multi-card, the operator simply presses a given key, which may be a touch sensitive pad, which causes multi-card to activate and the display 5 to display which account is associated with that key. If the operator forgets which key is associated with a wanted account, he may simply operate all keys in sequence until the correct account is selected. It will be understood that it is also possible to provide only one key, with a different account called up for each press.
When each account is called, the magnetic data for that account is loaded into the magnetic strip 4 , causing the magnetic strip to simulate the magnetic strip on the prior art type card by emulating, approximating, replicating or duplicating the magnetic pattern, depending on the accuracy required by the device reading the pattern. The control of the accuracy provided may be provided by the operator, or may be automatic in response to feedback (or lack thereof) by the device using the card. In this fashion, the multi-card may then be placed into a card reader or other device which reads the magnetic pattern from the magnetic strip to allow the holder access to the account, services or features associated with the stored data or pattern.
It will be recognized by one of ordinary skill in the art from the teachings herein that the invention allows access to numerous accounts, services, features, etc. with just one card thereby eliminating the need to carry, store or retain numerous cards. Other features may be combined with the invention as well, or as the case may be the invention may be combined with other functions, examples including personal reminder and memory capability, calculator and clock or even telephone and television functions.
Other sequences of operation of the invention may be utilized as well. For example, the key pad may be used to enter a convenient select designator, for example a BC representing bank card or a PBC indicating personal bank card, or any other convenient select designator. The select designator will then cause the account identifier to be displayed on 5 and the proper pattern loaded into 4 . In addition, the loading of pattern into 4 may be caused to occur only when another command is generated by the operator, or only upon or after insertion of the card in a device which uses it. These operations are considered to be novel features of the invention.
It will be understood by one of ordinary skill in the art that elements 3 and 5 - 9 are well known and commonly found and utilized in the industry and may be controlled by a microprocessor with their application and use in the preferred embodiment of the invention being within the capability of one of ordinary skill in the art.
FIG. 7 shows an top and side views of an alternate mechanical embodiment similar to FIG. 2 . The mechanical embodiment of FIG. 7 has the advantage of allowing a larger space for the electronics while maintaining a thin cross section in the “card” area, thus allowing easier fabrication.
FIG. 3 shows a diagram of the multi-card and a supporting console which may be used to store information or patterns in the multi-card or recover information or patterns from the multi-card, or another card. A control circuit 11 , which is preferred to be a microprocessor such as an Intel 80C31 or which may have internal ROM, ram and nonvolatile ram as is known in the industry, is utilized to control and operate the various elements of the multi-card.
As an example the Intel 80C31 series microcontroller is well suited to the control task. When the 80C31 is coupled with a nonvolatile ram such as the Xicor X2444 available from Xicor, Inc. 1511 Buckeye Drive, Milpitas, Calif., a keypad such as can be easily constructed with the ITT Schadow KSA1M211 switch available from ITT Schadow Inc. 8081 Wallace Rd., Eden Prairie, Minn., and an LCD display such as the Optrex DMC20261NY-LY-B, available from 44160 Plymouth Oaks Blvd., Plymouth, Mich., the invention components may be readily constructed. A 16 keypad matrix in 4×4 form (not all 16 need be used) is preferably configured on the 8 P1 port connections, the LCD is preferably configured on the P0 data port under write control as addressed by the P2 data port and controlled by the /WR control. The input/output interface 14 is preferably provided via the TXD/RXD serial ports (alternate functions provided on the P3 port), and the nonvolatile ram is preferably configured directly to the /INT0, /INT1 and T0 pins of the P3 port. The program instructions to run the processor are preferably stored in an EPROM having data pins coupled to the P0 port and addressed by the P2 port under /RD read control as is commonly known in the industry. Intel provides a wealth of information on configuring, programming and operating this and many other processors, which information is available from Intel Corporation, 3065 Bowers Ave., Santa Clara, Calif.
The programmable magnetic strip 10 is preferred to contain multiple inductive coils to generate magnetic fields in response to current flowing therein, as will be described in more detail below. The connection of the processor of 11 , be it an 80C31 or other type may be made directly via matrixing of the two connections of the individual coils in 10 , for example as is commonly done to write (and read from) core type magnetic memory in the computer industry. Alternately, a large serial shift register array may be loaded with serial binary data under control of 11 with the array's output being enabled to a low impedance state from a high impedance state after loading. The binary data may thus cause the many parallel outputs, each of which is coupled to a coil, to source electrons into the coil, or sink electrons from the coil, providing that the other end of each coil is connected to a voltage source which is midway between the output's high and low logic level states. To achieve control over the current flow through the coils, multiple serial shift registers may be utilized, with several outputs being coupled to each coil through resistors or other current controlling circuits, the pattern of data in the several outputs controlling the current flow.
Several variations of the suggested elements of the preferred embodiment may be utilized as will be convenient to implement particular embodiments of the invention which may be configured to specific needs and applications, as will be apparent to one of ordinary skill in the art from the teachings herein.
The substrate 3 may be of any material on or to which the other elements may be suitably secured or attached, examples including the preferred PVC plastic, ceramic, metal and others. Display 5 which is used to provide messages to the user of the device may be of any electro optical type such as LCD, LED, CRT, incandescent, fluorescent, flip dot, etc. or may be of electro mechanical type such as beeper, buzzer, vibrator, etc., or may be eliminated in applications where it is not desired to convey messages to the user, or where messages are conveyed via other means. Such other means for example include via the device which reads the magnetic strip 4 .
Power source 6 may be any well known power source, such as solar cell, battery, electric generator operating to convert motion to electricity, fuel cell, electromagnetic or electric field receiver, piezoelectric generator, etc. or any combination thereof.
Emitter 7 may be the preferred infrared LED, antenna, coil, transducer, or any other device capable of conveying information or patterns from the invention to outside devices, and receiver 8 is preferred to be a photo transistor but may also be any such apparatus or device capable of receiving information or patterns from outside devices to be used by the invention. Either or both of the emitter and receiver may be eliminated if the capability provided is not desired, or is otherwise provided for. For example, the sensing capability of 10 or the input capability of 13 may be utilized to provide the receiver 8 function and the display 12 may be utilized to provide the emitter function.
Touch sensitive key pad 9 may be capacitive, heat sensing, optical or mechanical switches, etc. or any device capable of receiving and coupling operator input to the invention. The operator interface 13 and its key pad 9 may also be eliminated if no operator interface is desired.
The control circuit operates with the programmable magnetic strip 10 , examples include those corresponding to 4 of FIG. 2, to create a predetermined magnetic pattern which may be read by compatible reading devices, and may also operate in conjunction with 10 to sense magnetic patterns. Control circuit 11 also drives the LCD display 12 , examples including associated with 5 of FIG. 2, to display messages to the operator and as signified by the dotted arrow on the control circuit 11 may also operate interactively with 12 . Control circuit 14 operates interactively with the input/output interface 14 , examples including those associated with 7 and 8 of FIG. 2, to communicate with the console. Control circuit 11 also operates interactively with operator interface 13 , examples including those corresponding to 9 of FIG. 2, to allow operator input to the control circuit. Also shown in FIG. 3 is a power source 15 , examples including those associated with 6 of FIG. 2, and which provides power for the operation of the multi-card. In the preferred embodiment, 15 includes a replaceable nickel cadmium battery and solar cell allowing the battery to be replaced and/or recharged. It is of course possible to use either replaceable or rechargeable power sources.
FIG. 3 includes a console comprised of programming circuitry 16 and card reader 17 . In operation, the card reader may be operated to read information or patterns from a particular data storage medium, examples including the magnetic strip on a credit card. The information or patterns may be read as the actual data represented in any of its various forms, or may be read simply as the representation. With respect to reading a magnetic stripe, the reader may simply read the magnetic pattern without concern as to the data represented thereby, or may decode the magnetic pattern into the encoded (that is represented) data, or may decode the data to the unencoded (that is unprotected by security scrambling and the like) data as is convenient. In the preferred embodiment, the magnetic pattern is simply sensed at a high resolution by moving the magnetic strip over a magnetic sensor and generating a binary representation of the polarity of the magnetic field in response thereto. The resulting binary pattern corresponds to the magnetic polarity field, in the preferred embodiment at 0.001 inch increments, giving a linear “snapshot” of the magnetic pattern.
The binary representation is then coupled to the programming circuitry 16 (via 14 ) where an account identifier is associated therewith to later be displayed on the display 12 when the wanted corresponding magnetic pattern is recalled from the memory in the control circuit 11 . While called an account identifier, there is no need that the pattern correspond in any way to an account, and may well correspond to anything. The account identifier may be thought up by the operator, may be chosen by the operator from a list or other source, or may be assigned without operator intervention, for example preprogrammed in the card which is read or in the control circuit 11 . The input of the account identifier may be via 13 or 16 as is desired. It is however preferred that the operator may have some choice in the matter in order that an account identifier which is either convenient to or associated by the operator is used, and thus it is preferred that 16 contain a keyboard with which the operator may type in his desired identifier, and the desired key, key sequence or location associated therewith.
It is also preferred to associate a select designator with the binary representation, in order to allow the operator to utilize the select designator to call up a particular magnetic pattern. The select designator may be thought up by the operator, may be chosen by the operator from a list or other source, or may be assigned without operator intervention, for example preprogrammed in the card which is read or preprogrammed in the control circuit 11 at the time of manufacture or other time.
In operation, it is preferred that there be more than one method for the operator to call up a wanted pattern. One preferred way is for the operator to enter the select designator. This causes the account identifier to be displayed in 12 . Alternatively, the operator may scroll through all the possible sets of data, viewing each account identifier as it appears until the desired one is called up, or may key in a more detailed pattern, to call up the desired account.
The magnetic pattern (or data represented thereby in some form) is then caused to be stored in the memory of 11 in a form which allows it to be associated with the identifier, and preferably also with some known input terminal or sequence of terminals of 9 . In the preferred embodiment, the operator chooses an available key of 9 (for example the upper right) or other select designator, provides an account identifier, (for example BANK CARD) and the operator choices and data are stored in 11 in a fashion which associates them all. It is preferred that the data be stored in nonvolatile memory in order that it will be retained in the event that the power storage device of 15 is fully discharged or the control circuit is turned off, for example to save power.
It is preferred that by utilizing the foregoing programming procedure, the operator stores the magnetic pattern, account identifier and desired associated select designator in 11 . Upon subsequent entry of the associated select designator, the control circuit 11 recalls the associated data corresponding to the magnetic pattern and the account identifier from memory. The account identifier is loaded in the display 12 to remind the operator what the data is associated with, and the magnetic pattern is caused to be replicated in 10 from the stored data. The replicated magnetic pattern in 10 may then be utilized to operate a card reading device to provide the operator access to the account, services, features or other conveniences associated therewith, and hence associated with the card which was read by 17 .
It is of course desired to provide the capability of storing several such sets of associated data, identifier and key in the memory of 11 , and it is further desirable to provide for the association of multiple select identifiers with a given set of data. By way of example, in this fashion, a set of data for generating a magnetic pattern for a company issued bank card may be called up by use of any of the select identifiers cc, or COCARD or COMPANY CARD, etc. and another set of data for a personal bank card may be called up by use of any of the select identifiers PC, PBC, etc.
FIG. 4 shows a diagram of the details of the magnetic strip 10 and control circuit 11 , including individual electromagnet coils, one of which is shown as 21 and having electric circuit connections 22 and 23 , and magnetic flux conducting material 20 . It will be recognized that by passing an electric current through a given coil that a magnetic flux will be created across the associated gap in the magnetic flux conducting material 20 above the coil, such as is represented by 24 . Furthermore, the flux for each coil will be largely contained in the gap corresponding to that coil by the magnetic flux conducting material. The polarity of the flux may of course be changed by changing the direction of current flow through the coil, and the intensity of the magnetic flux may be varied by varying the electric current through the coil. In this fashion, the original magnetic pattern which was read by reader 17 may be approximated, duplicated or replicated as required. While it may be desirable to cause the control circuit 11 to have the ability to vary the accuracy with which it stores the magnetic data or programs the magnetic strip, it will be recognized that this is not a requirement, and 11 may simply operate to a single given accuracy. It may also be noted that the material used for 20 may be of a type having a large magnetic memory or hysteresis so that once a magnetic pattern is generated in the material, the electric current through the coils may be turned off or reduced and the magnetic field will remain. Techniques which are used to write and read magnetic core type memory, as well as the materials used therefore, will be applicable to the generation of magnetic patterns for 10 , and the technology used in the core industry may be easily adapted to be used in fabricating 10 . It will also be recognized that other methods of creating magnetic patterns may be utilized as well, such as various chemical, thermal and optical methods which may be utilized to create magnetic flux patterns, or to alter existing flux patterns.
FIG. 5 shows a sectional diagram A—A of elements 20 - 23 of FIG. 4 and the preferred method of construction thereof. This method of construction is readily implemented with either photographic lithography and lamination techniques or with chemical vapor etching and deposition as are commonly utilized to fabricate miniature electronic circuits. Other construction methods may be utilized as well.
Element 18 is a substrate material, examples including plastic or ceramic, on which the magnetic coils 21 may be built. a conductive layer 19 is formed on the substrate in a predetermined pattern to make up the bottom half of the coils 21 . This layer may be created by depositing or printing a continuous metallic film and then etching away all but the desired conductive paths, or by photographically printing the conductive paths. Next, the magnetic material 20 is formed on top of the bottom conductive paths. Preferable the magnetic material is an electrically non-conductive or low conductive material, but if it is conductive, an insulating layer may first be deposited to prevent it from shorting out the top and bottom conductive paths. After the magnetic material is formed the top electrically conductive layer is formed thereover using the same process as for the bottom, thus completing the coils 21 . Finally, conductive wires or circuits 22 and 23 are bonded to the coils for connection to 11 , and the entire magnetic strip is provided with an environmentally insulating covering if desired to shield from moisture, corrosion, etc. By utilization of this method, it will be seen that very low manufacturing cost and small size may be obtained. It will also be understood that the linear array of coils is given by way of example with respect to the preferred embodiment and may be arranged in other than a linear fashion, for example in circular or three dimensional patterns. It will also be understood that the magnetic coils may be replaced with LEDs to create emitted light patterns, or by LCD elements to create reflected or transmitted light patterns, or by any other type of energy radiator, absorber or deflector in order that the invention may be practiced with virtually any sort of emitted, absorbed or deflected pattern.
It will be recognized that while the coils may be utilized to generate a magnetic pattern, they may also be utilized to sense a magnetic pattern. While some motion is required to generate an electric current in the coils, this motion may be supplied by the user. In addition, magneto restrictive materials may also be adopted to allow sensing of magnetic patterns without motion. One of ordinary skill in the art will be able to construct such a device and practice the invention from the teachings of the preferred embodiment given herein without undue experimentation or further invention. It will also be recognized that it will be possible to have magnetic strip 10 sense the magnetic pattern on another magnetic strip directly, removing the need for card reader 17 . It would also be possible to incorporate the programming circuitry 16 in the control circuit 11 , thus completely eliminating the need for the console of FIG. 3 . Once the console is eliminated, the input/output interface 14 may also be eliminated.
One skilled in the art will also recognize that an inexpensive version of the invention may be constructed of simply a programmable magnetic strip 10 which can both read and simulate a magnetic pattern, a control circuit 11 , an elementary operator interface 13 and a power source 15 .
Alternatively, instead of a magnetic strip 10 capable of reading, several preprogrammed magnetic patterns may be programmed in control circuit 11 upon manufacture, either by storage of the magnetic patterns, storage of data which may create the magnetic patterns or storage of an algorithm or method by which the magnetic pattern may be created in 10 under control of 11 . In such a system, only elements 11 and 10 are absolutely required since it would be possible for 11 receive commands from the reading device via 10 , or to simply try all stored patterns in 10 upon excitation or connection of the power source 15 .
While the preferred embodiment of the invention has been given by way of example with respect to credit cards having magnetic strips, it will be recognized that the invention may very well be adapted for use with other methods of storage and storage medium. Examples include, simulating two or more dimension patterns. Optical devices which record data on film in two or more dimensions may be replaced by liquid crystal or other optical displays which simulate the patterns recorded on the film. Holographic recordings may also be simulated by LCD or other optical displays. Mechanical devices may be replaced by electromechanical devices in which mechanical dimensions are adjusted via solenoids, motors, piezoelectric cells or the like. Keys are an excellent example of a device which may be replaced by a battery of such adjustable devices.
In FIG. 6 for example, the device of FIG. 3 may be utilized in conjunction with micro machines in order to create an adjustable key in which the operator selects an identifier corresponding to the particular lock which he wishes to unlock. The device uses electromagnetically driven micromotors and worm screws to adjust the serrated edge on the key to fit the lock. A sectional view of the device is shown in which a standard key blank 25 is machined to couple to a bank of micro motors or solenoids 26 , each of which is connected via a worm screw to a flexible shaft or wire which extends to the serrated edge of the key.
By way of example, micromotor 27 is coupled to flexible shaft 28 which passes through a hollow portion of the key blank 25 to the serrated edge where it protrudes through the blank at 29 . Individual channels may be micromachined for the flexible shafts, or the shafts may simply be sized to fill the slot in the key blank, or bundled together to prevent lateral displacement which would affect the protrusion distance from the edge of the key blank at 29 . The micromotor 27 , via the screw, adjusts the position of the end of 28 to thereby control the length of protrusion of the other end at 29 , thus adjusting the depth of the serration at that point. All of the micromotors in the bank 26 are coupled to the control circuit 11 of FIG. 3 by a suitable coupling. In this fashion, the key may be adjusted to fit different locks as desired by the operator. In this example, card reader 17 may be replaced with a key reader in order that the serration pattern of precut keys may be read into 11 and stored, along with account identifiers, select designators, etc. as previously described.
In view of continuing development of micro machines on silicon wafers by use of semiconductor fabrication techniques, it is envisioned that it will be possible to manufacture both electro mechanical components such as solenoids and the corresponding electrical control circuitry all on the same semiconductor substrate. In this fashion, it would be possible to manufacture the invention of FIG. 6, including the necessary control circuitry of FIG. 3 entirely with existing semiconductor fabrication technology.
It would also be convenient to replace the electronic storage of different patterns with a mechanical or other storage of patterns, for example with respect to the key of FIG. 6 on a rotating cam shaft, shown as 27 of the inset, which would be rotated to adjust the height of spring loaded pins on the key, the springs holding the pins against the cams. While the configuration of the inset would require a fairly wide key, the camshaft could also be located entirely within the handle of the key and be coupled to the spring loaded pins via flexible shafts or wires 28 as with the micromotor actuator 26 . The account identifiers or select identifiers can be engraved directly on the end of the shaft. It will be understood that the flexible shafts may be arranged in other than a linear fashion, for example in circular or three dimensional patterns.
The invention described herein by way of explanation of the preferred embodiment may be practiced with numerous changes in the arrangement, structure and combination of the individual elements, as well as with substitution of equivalent functions and circuits for the elements in order to optimize the invention for a particular application, all without departing from the scope and spirit of the invention as hereinafter claimed. | The apparatus and method described herein provides for creating multiple spatial patterns, such as magnetic patterns on credit cards. The invention includes storage of information from which patterns may be created, a pattern creation device for creating the spatial patterns, and control whereby the information which is stored is selectively utilized to cause the pattern creation. This allows multiple desired patterns to be simulated, allowing convenient replacement of a number of separate pattern carrying devices. | 6 |
BACKGROUND OF THE INVENTION
[0001] It is often difficult to change light bulbs where the sockets are significantly above the level of the floor. Although some people use ladders, sometimes the ladders still are insufficient for reaching certain bulbs. Extenders exist, but they are often cumbersome and are difficult to use when dealing with angularly positioned light sockets. The present invention addresses this by providing a suction cup operatively associated with an electromechanical device for grasping a light bulb and subsequently releasing the light bulb.
SUMMARY OF THE INVENTION
[0002] The present invention uses a pneumatic solenoid valve coupled with a suction cup to grasp and release the surface of a light bulb in the suction cup utilizing air pressure differential.
[0003] In one embodiment, an electric solenoid valve is used in conjunction with a suction cup, whereby applying voltage can either open the valve and let air in releasing suction or it can be open until current applied and than it closes it.
[0004] In one embodiment, the valve is controlled with a push button that actuates a momentary electrical current that is applied thereby releasing the suction. When the button is not pushed no energy is expanded to keep valve closed, and therefore battery last a long time.
[0005] In one embodiment, an additional vacuum is used to allow ease of attachment.
[0006] In addition the suction cups configured in the present invention have small nubs about the perimeter. This prevents hover effect which prevent cup from slipping and allows for placement of cup on center of bulb for better attachment. Without this cup slides off to side and final placement on bulb is eccentric, making its dislodgment more likely.
[0007] In one embodiment, the Invention utilizes the suction for ease of attachment. The system and method of the invention includes attaching coiled wire to transmit current and allows telescoping of pole. Without this technique undo pressure on electrical connection at top and bottom would result in failure.
[0008] In one embodiment the present invention is an apparatus for connecting and disconnecting light bulbs, said apparatus comprising:
a suction cup having a mounting surface; a suction cup support having an angularly flared surface adjacent to and in the direction of said suction cup; and at least one structure constructed and arranged to introduce air to said mounting surface.
[0012] In one embodiment, the structure constructed and arranged to introduce air to said mounting surface is a release tab.
[0013] In one embodiment, the structure constructed and arranged to introduce air to said mounting surface is an air channel operatively associated with a solenoid valve.
[0014] In one embodiment, the solenoid valve is a mechanical, non-electric valve.
[0015] In one embodiment, the solenoid valve is an electric valve.
[0016] In one embodiment, the valve is actuated by an actuator with direct hard-wired connection.
[0017] In one embodiment, the valve is actuated by an actuator with a wireless connection.
[0018] In one embodiment, the cup support is constructed and arranges as two congruent half circles that snap fit into a support base.
[0019] In one embodiment, the apparatus further comprises a support pole.
[0020] In one embodiment, the support pole is constructed and arranged as a telescoping pole.
[0021] In one embodiment, the angular flare is between about 5-20 degrees.
[0022] Also contemplated is a method of installing a light bulb, said method comprising the steps of:
providing an apparatus according to the present invention; providing a light bulb to be installed in a light bulb socket; positioning said light bulb onto said mounting surface; applying pressure from said light bulb in a direction of said mounting surface; imparting suction upon said light bulb from said applying of pressure; positioning said light bulb for installation into said light bulb socket; rotating said assembly in a manner such that said light bulb mates with said light bulb socket; and introducing air to said suction cup mounting surface by activating said structure constructed and arranged to introduce air to said mounting surface.
[0031] In one embodiment, the method further comprises providing said suction cup with at least one release tab positioned along a perimeter edge.
[0032] In one embodiment, the method further comprises applying pressure on said release tab in a direction away from said light bulb.
[0033] In one embodiment, the method further comprises providing a solenoid valve and an air delivery channel, whereby said air delivery channel is configured to deliver air to said mounting surface.
[0034] In one embodiment, the method further comprises said solenoid valve is a mechanical non-electric valve.
[0035] In one embodiment, the method further comprises solenoid valve is an electric valve.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0036] FIG. 1 is an exploded perspective view of components according to one embodiment of the present invention.
[0037] FIG. 2A is a separated perspective view of the solenoid and suction cup assembly with one embodiment of the present invention.
[0038] FIG. 2B is demonstrative of lightbulb placement in a suction cup assembly according to one embodiment of the present invention.
[0039] FIG. 3 is a side partial cross-section view of the solenoid and suction cup assembly according to one embodiment of the present invention.
[0040] FIG. 4 is a side partial cross-section view of the solenoid and suction cup assembly according to one embodiment of the present invention whereby the solenoid is in an open position.
[0041] FIG. 5 is a side partial cross-section view of the solenoid of FIG. 2B along section line A-A.
[0042] FIG. 6 is a side partial cross-section view demonstrative of the suction cup in a non-aligned position.
[0043] FIG. 7 is a separated perspective view demonstrative of a pole and support sub assembly according to one embodiment of the present invention.
[0044] FIG. 8 is demonstrative of placement of connected components from FIG. 7 .
[0045] FIG. 9 demonstrates placement of power supply in the poll according to one embodiment of the present invention.
[0046] FIG. 10A is an end view of the current seal inner support according to one embodiment of the present invention.
[0047] FIG. 10 B is a side partial cross-section view of the cup seal inner support according to one embodiment of the present invention.
[0048] FIG. 11 A is a side partial cross-section view of the spacer clamp “C” configuration according to one embodiment of the present invention.
[0049] FIG. 11 B is an end view of a spacer clamp “C” configuration according to one embodiment of the present invention.
[0050] FIG. 11 C is a side partial cross-section view of the spacer clamp “semicircle” configuration according to one embodiment of the present invention.
[0051] FIG. 11 D is an end view of a spacer clamp “semicircle” configuration according to one embodiment of the present invention.
[0052] FIG. 12 A is an end view of a suction cup with one embodiment of the present invention.
[0053] FIG. 12 B is a side view of a suction cup according to one embodiment of the present invention.
[0054] FIG. 13 A is an end view of a suction cup point to one embodiment of the present invention showing placement of a release tab.
[0055] FIG. 13 B is a side view of a suction cup of corn to one embodiment of the present invention demonstrating placement of a release tab.
[0056] FIG. 14 A is a side view of a suction cup according to the present invention showing indents.
[0057] FIG. 14 B is an end view of a suction cup according to the present invention showing indents.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0058] The present invention relates generally to a device for reaching light bulbs that are beyond the normal reach of most persons.
[0059] As generally understood, assembly 10 is constructed and arranged for supporting light bulb 30 . Suction cup 16 is dependent upon clamp 24 . When light bulb 30 is affixed to suction cup 16 , suction cup cavity 17 (not necessarily drawn to scale) is a small cavity or void that is operatively associated, as will be described below, with structure to direct air into suction cap cavity 17 as desired and thus release light bulb 30 from suction cup 16 . Cavity 17 envelopes the part of light bulb 30 inserted into suction cup 16 that is light bulb mounting surface 19 , which is understood to be only that part of the light bulb surface defined by placement within the perimeter of suction cup 16 . In one embodiment, spacer clamp 24 as best seen in FIG. 11 B is in a “C-shape” configuration as shown. Positioned adjacent to suction cup 16 and clamp 24 is solenoid valve 14 . Pole 20 is constructed and arranged to incorporate therewith a cup seal inner support whereby said cup where is configured either as where no power supply is incorporated therein 26 A or cup whereby a power supply 36 is incorporated therein.
[0060] In one embodiment, transistor 21 is utilized in the electrical components to account for wire length.
[0061] Pole 20 supports suction cup 16 on a first end and handle 38 on a second end.
[0062] Solenoid suction cup assembly 28 includes in one embodiment a power source 36 with power actuator 18 whereby power cord 33 the levers of electricity from power control subassembly 32 to solenoid valve 14 . First orifice 35 provides for an inner passage from solenoid valve 14 to cavity 17 of suction cup 16 and second orifice 31 provides for an exhaust air passage from the assembly. Angle 50 demonstrates acute angular offset of suction cup 16 from a central axis of assembly 10 . In one embodiment, an internal power cord 33 provides for actuation of power source 36 to solenoid 14 when actuator 18 is activated.
[0063] In another embodiment, as demonstrated in FIG. 9 , wireless where 34 transmits a wireless signal to wireless switch 37 that initiates and ceases power to solenoid 14 . In one embodiment as demonstrated in FIGS. 12 A and 12 B suction cup 16 is presented as shown. In another embodiment as demonstrated in FIGS. 13 A and 13 B release tab 16 a is constructed and arranged along the perimeter of suction cup 16 whereby release tab 16 a is configured to receive a release line whereby section is interrupted and light bulb 30 is released once positioned. In an embodiment demonstrated in FIGS. 14 A and 14 B, a plurality of nodes 70 is positioned about the perimeter of suction cup 16 . Nodes 70 assist by releasing suction and subsequently releasing attachment a light bulb 30 from suction cup 16 .
[0064] In one embodiment, as demonstrated in the FIGS. 11A and 11B spacer clamp 24 is provided in a “C-shaped” configuration. In another embodiment, as in FIGS. 11C and 11D clamp 24 is provided as to complementary semicircles constructed and arranged to snug fit into either cup support 26 A and 26 B.
[0065] In one embodiment, surface 25 of either cup seal 26 A and 26 B is angularly flared towards suction cup 16 . This cup seal angular flare, shown in FIG. 10B as dimension X, provides support for suction cup 16 when holding and installing light bulb 30 . In one embodiment, dimension X, being cup seal angular flare is between about 5-20 degrees.
[0066] In one embodiment, Solenoid valve 14 is electrically actuated. In another embodiment, solenoid valve 14 is mechanically actuated.
[0067] In one embodiment, a user will position light bowl 30 on two suction cups 16 and apply pressure until suction cup 16 grasps the outer surface of light bulb 30 . Once like bold Bertie is in position a user will attach light bulb 30 to a socket by rotating the entirety of assembly 10 . Once light bulb furry is completely installed, a user will then desire to release suction cups 16 from lightbulb 30 .
[0068] According to the present invention, the desired release is accomplished through various embodiments.
[0069] In one embodiment, a string or other extending member is connected to tab 16 a. The user will pull the string in the direction away from the first end of assembly 10 , being the end with suction cup 16 and towards the second end of assembly 10 , being the end with handle 18 .
[0070] The tab will lift an edge of suction cup 16 , allow air to enter the space between suction cup 16 and light bulb 30 and subsequently release the suction imparted by suction cup 16 onto light bulb 30 . Once this suction is released, the light bulb detaches.
[0071] In another embodiment, solenoid valve 14 inserts air into the space between suction cup 16 and light bulb 30 . Once they air is inserted into the space the suction is released and the light bulb detaches.
[0072] As stated above solenoid 14 is selectively an electrically operated solenoid or a mechanical solenoid.
[0073] In one embodiment, when an electrically actuated solenoid valve 14 is utilized, a transistor is positioned between the battery and the solenoid such that resistance due to wire length is negated. In this embodiment, this is an important feature because internal wiring in one embodiment is coiled to provide for length differentials when pole support 20 is constructed and arranged as a telescoping pole. | The invention is an apparatus for connecting and disconnecting light bulbs including a suction cup and at least one structure for interrupting suction to the suction cup. | 7 |
FIELD OF INVENTION
The invention relates to the authentication of merchandise units, and in particular, to authentication of merchandise units identified by serial numbers.
BACKGROUND
Serial numbers, such as the electronic product code, can be used to identify particular units of merchandise. These numbers can be used to track the location of a merchandise unit and to trace the origin and history of a particular unit as it travels from one stop to the next along a supply chain. The ability to do so is useful because it enables one to identify specific manufacturing lots that may correspond to tainted or defective goods. Other units with the same or similar history can be then be traced and recalled as needed.
At each stop in the supply chain, it may be desirable to establish the authenticity of a merchandise unit. In such cases, a serial number is of little value. A serial number, whether it is encoded in a bar code or printed directly on a package, can easily be copied. Inspection of a serial number provides limited basis for distinguishing counterfeit goods from authentic goods. At best, one may recognize that the serial number is syntactically incorrect, perhaps by recognizing that the number of characters is incorrect, or that letters are present where numbers should be and vice versa. However, a skilled counterfeiter is unlikely to make such errors.
In some cases, the serial number is not even visible. For example, the serial number may be encoded in an RFID tag. In these cases, one must rely on the availability of a reader to read the serial number. However, having read a serial number from an RFID, one encounters the same problem: it is difficult to tell from the serial number alone if the merchandise unit is authentic. A skilled counterfeiter can readily encode a syntactically correct serial number onto an RFID tag just as he can print a syntactically correct serial number on a package.
SUMMARY
In one aspect, the invention includes a system for authenticating a merchandise unit. Such a system include a memory for storing an electronic product code obtained from the merchandise unit. This electronic product code identifies the merchandise unit. The system also includes a sensor for detecting an attribute of a marking medium associated with the merchandise unit. The system is configured to output data representative of the attribute and the identity of the merchandise unit.
Some embodiments also include a processor for determining whether the attribute corresponds to the electronic product code or whether the attribute corresponds to a range that includes the electronic product code.
A variety of sensor types can be used. Exemplary sensor types include fluorescence detectors and sensors configured to detect a physical property of a nucleic acid sequence.
In other embodiments, the system also includes a reader configured to read the electronic product code from the merchandise unit. Examples of suitable readers include RFID tag readers and bar code scanners.
In another aspect, the invention includes a merchandise unit having both a mark encoding an electronic product code that identifies the merchandise unit, and a marking medium having an attribute that corresponds to the electronic product code.
Exemplary marks include marks in which information is encoded as a bar code, and marks in which information is encoded in an RFID tag.
Embodiments include those in which the marking medium is a fluorescent material, and those in which the marking medium is a nucleic acid sequence.
In some embodiments, the marking medium is associated with packaging of the unit. However, in others, the marking medium is associated with labeling of the unit. In still others, the marking medium is associated with a product associated with the unit.
The invention also includes a methods for evaluating authenticity of a merchandise unit. One such method includes reading an electronic product code from the merchandise unit, measuring a value of an attribute associated with the merchandise unit, and determining whether the value corresponds to the electronic product code.
In some practices, reading an electronic product code includes reading a bar code.
Other practices include those in which measuring a value includes observing a fluorescence, and those in which measuring a value includes observing a property of a nucleic acid sequence.
In some practices of the invention, determining whether the value of the attribute corresponds to the electronic product code includes determining whether the electronic product code is within a range of permissible electronic product codes.
An additional aspect of the invention is a marking system for marking merchandise units. Such a marking system includes a marking station having a serial number applicator for associating an electronic product code with a merchandise unit; and a marking medium applicator for associating a marking medium with the merchandise unit. The marking medium has an attribute that corresponds to the electronic product code associated with the merchandise unit.
In some embodiments, the system also includes a processing system in data communication with the marking station. For each merchandise unit marked by the marking station, the processing system stores data indicative of a relationship between the attribute value and the electronic product code.
Embodiments of the invention include those in which the serial number applicator includes an RFID programming unit, as well as those in which the serial number applicator includes an ink jet printer.
Other embodiments include those in which the marking medium applicator is configured to associate a fluorescent material with a merchandise unit, and those in which, the marking medium applicator is configured to associate a nucleic acid sequence with a merchandise unit.
In some embodiments, the processing system is in data communication with the marking medium applicator over a wide area network.
In another aspect, the invention includes a methods for marking a merchandise unit. Such methods include associating an electronic product code with a merchandise unit, and associating a marking medium with the merchandise unit. The marking medium has an attribute that corresponds to the electronic product code associated with the merchandise unit. Such methods further include storing, for each merchandise unit marked by the marking station, data indicative of a relationship between the attribute value and the electronic product code.
Alternative practices of the invention include those in which associating an electronic product code with a merchandise unit includes encoding the code in an RFID tag, and those in which associating an electronic product code with a merchandise unit includes printing the electronic product code on the merchandise unit.
Additional practices of the invention include those in which associating a marking medium with the merchandise unit includes associating a fluorescent material with a merchandise unit, and those in which associating a marking medium with the merchandise unit includes associating a nucleic acid sequence with a merchandise unit.
In some practices of the invention storing data includes transmitting the data to a storage location over a wide area network.
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 invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.
Other features and advantages of the invention will be apparent from the following detailed description, and the accompanying figures, in which:
DESCRIPTION OF DRAWINGS
FIG. 1 is a representation of a supply chain; and
FIG. 2 is a merchandise authenticator for use in the supply chain.
DETAILED DESCRIPTION
A merchandise unit 8 , as shown in FIG. 1 , can be identified by a serial number 9 , such as an electronic product code. An electronic product code associated with a merchandise unit 8 can be programmed into an RFID (radio frequency identification) tag, printed on a bar code, or printed in human-readable form on a package or label associated with the merchandise unit 8 . The merchandise unit 8 includes a product and, optionally, labeling identifying the product and packaging to protect the product.
Marking Media
Integrated into the merchandise unit 8 , either in the product itself, or in its associated packaging and/or label if any, is a marking medium having an attribute selected to depend, to some extent, on the serial number. The marking medium may or may not be visible to the naked eye. However, the relationship between the marking medium and the serial number 9 associated with the merchandise unit 8 is not readily ascertainable from examination of either the merchandise unit 8 , the marking medium, or the serial number 9 .
As used herein, an “attribute” of the marking medium refers to an observable physical property associated with the marking medium that is related to a serial number associated with a merchandise unit. The marking medium can thus be viewed as a steganographic feature associated with the merchandise unit 8 , with the message provided by that steganographic feature being a message encoded in a value of the attribute. The content of the message includes information about the serial number associated with the merchandise unit 8 . The marking medium can also be viewed as a watermark, with the nature of the watermark being dependent on the serial number associated with the product.
The correspondence between the attributes of a marking medium and the serial number need not be a one-to-one correspondence. In some applications, it may be sufficient for the value of an attribute to identify a manufacturing lot associated with a serial number. In general, a value of an attribute of a marking medium can correspond to a single serial number, or to a set of serial numbers. Such a set can be one in which the serial numbers are sequential, i.e. a “range” of serial numbers, or the set can be one in which the serial numbers are arbitrarily selected, so that no readily discernible pattern is observed in the serial numbers belonging to the set. To the extent that the relationship is secret, counterfeiters are more likely to be thwarted.
One example of a marking medium is a dye. For example, a dye corresponding to a first set of serial numbers may fluoresce at a first set of wavelengths, while a dye corresponding to a second set of serial numbers may fluoresce at a second set of wavelengths that is distinct from the first set. In this case, the attribute is a spectrum, and information about the serial numbers of the merchandise unit 8 is encoded as a pattern of spectral lines, which in this case is the “value” of that attribute.
Another example of a marking medium is a polarizing substance, i.e. one that alters a polarization state of light passing through it. In such a case, a range of polarization angular rotations may correspond to a range of serial numbers. The attribute would then be the polarization vector of the medium, and information about the serial numbers 8 associated with the merchandise unit would be encoded as specific values of a polarization angle.
Another example of a marking medium is a substance that alters an index of refraction. In such a case, a wave passing through the substance can be deflected by an angle that depends on serial number. Alternatively, a wave passing through the substance can be made to experience a phase delay that depends on serial number. In this case, the attribute is the refractive index, and the value is a deflection angle.
Alternatively, one can measure a reflection coefficient, a transmission coefficient, or a standing wave ratio that is made to depend on serial number by varying the impedance (and hence the index of refraction) of the medium. All of these attributes can thus be used to encode information indicative of a serial number associated with the merchandise unit 8 .
Another example of a marking medium is a radioactive substance. In such a case, the attribute is a decay rate or other radiation related parameter that provides independent confirmation of a serial number. One way to achieve this is to vary the ratio of radioactive isotopes as a function of serial number or sets of serial numbers.
Another example of a marking medium is a nucleic acid sequence, such as DNA, in which the pattern of nucleic acids is the attribute. Particular patterns, which are related to the serial number, are the “values” of that attribute.
A marking medium can be an integral part of the product's composition. For example, in the case of a liquid product, or a product that was once in molten form, the marking medium can be another liquid having suitable measurable attributes. This liquid can then be mixed into the product so that it becomes integral with and inseparable from the product. Exemplary products into which a marking medium can be integrated in this manner include room-temperature liquids, plastic articles or articles having plastic parts, and alloys.
Alternatively, the marking medium can integrated into either the labeling or the packaging of the product. For example, a label may be printed with an ink that includes, as one of its constituents, a marking medium such as those described above. Or, a product may be packaged in glass or plastic containers in which the marking medium is embedded in the container itself. For example, merchandise units bearing one range of serial numbers may be packaged in plastic containers that absorb a first wavelength, whereas merchandise units bearing another range of serial numbers may be packaged in plastic containers that absorb a second wavelength.
Marking the Merchandise Unit
The marking medium is best integrated into the merchandise unit 8 concurrently with, or substantially concurrently with, the application of a serial number 9 , whether the serial number is printed on the merchandise unit or encoded in an RFID tag that is then affixed to the merchandise unit 8 . This ensures that the merchandise unit 8 is uniquely identified from its inception at the beginning of a supply chain 10 .
To carry out this integration, the supply chain 10 features a marking station 11 having a serial number applicator 12 . The serial number applicator 12 (“SNA” in the figure) can include an ink jet printer for printing a serial number, or it can include an RFID tag applicator, or both.
The marking station 11 also includes a marking medium applicator 14 (“MMA” in the figure) that is in data communication with the serial number applicator 12 . The particular implementation of the marking medium applicator 14 depend on the particular marking medium. For example, if the marking medium is integrated into the glass or plastic that comprises a container, the marking medium applicator 14 includes a supply of empty containers of various types, and a mechanism for selecting a container and filling it with the product. The selection of the container is made on the basis of data provided by the serial number applicator 12 . This communication between the marking medium applicator 14 and the serial number applicator 12 ensures the correct relationship between the attributes of the marking medium and the serial number 9 .
The supply chain 10 can have several marking stations 11 at which a serial number applicator 12 and a marking medium applicator 14 cooperate in the manner described above. For example, one marking station 11 may be used to mark individual units at the beginning of the supply chain 10 . Another marking station 11 ′ can be placed further down the supply chain to mark boxes 13 into which the individual merchandise units are to be packaged. Yet another marking station 11 ′ can be placed further down the supply chain 10 to mark palettes 15 into which the boxes are to be loaded. Each of the marking stations 11 , 11 ′, 11 ″ is in communication with a central server 16 over a network 18 so that data indicative of a location of a particular merchandise unit 9 can constantly be updated on the central server 18 .
Note that boxes 13 and palettes 15 are, from the point of view of their respective marking stations 11 ′, 11 ″ also “merchandise units.” A “merchandise unit” is a purely logical construct to indicate what is being marked for identification.
Data Management
The authentication process includes inspecting the serial number on a merchandise unit 9 , measuring the value of an attribute, and determining if the value of the attribute and the serial number have an appropriate relationship. Thus, to facilitate the authentication process, the relationship between a measured attribute of the marking medium and the serial number can be made available.
In one embodiment, the central server 16 , which executes supply-chain management software, is in data communication with one or more supply chains 10 ′, 10 ″, each having one or more marking stations 11 as described above. The central server 16 can be remotely linked to the supply chains 10 , 10 ′, 10 ″, for example over the network 18 . The network 18 can be a wide area network, or a global network such as the internet. Or, the central server 16 can be local to a single supply chain 10 . As merchandise units 8 are marked, the supply-chain management software receives, from the marking stations 11 , data indicative of both the serial number 9 and the attribute of the marking medium. This data is then stored at the central server 16 or at a remote storage facility. Exemplary supply-chain management software includes that made available under the name “COLOS” by Markem Corporation of Keene, N.H.
The relationship between serial number 9 and attribute can be made arbitrary, with no particular algorithm relating the serial number 9 to the attribute. This method provides considerable security since even if the counterfeiter knew that there existed a relationship between a serial number 9 and an attribute value, it would be difficult to discern the particular relationship between them. In other cases, a function relates the serial number 9 to the attribute value or vice versa. In those cases, an algorithm to obtain the attribute value from the serial number 9 or vice versa can be stored on the central server 16 , so that one or the other can be computed whenever required. This method saves storage space at the expense of both computation time and security.
Authentication Unit
To authenticate a merchandise unit 8 , one provides the serial number to an authentication unit 22 , as shown in FIG. 2 . In some embodiments, the authentication unit 22 includes a reader 24 for reading a serial number from an RFID tag. The reader 24 can be a bar code scanner, an RFID reader, or any other reader. Alternatively, the serial number can be provided to the reader 24 by a human operator.
The authentication unit 22 also includes an interrogator 26 for inspecting the marking medium. The details of the interrogator 26 , like those of the marking medium applicator 14 , depend on the particular type of marking medium. The interrogator 26 can be an active interrogator that provides a stimulus to the marking medium and observes a response to that stimulus. Alternatively, the interrogator 26 can be a passive interrogator that observes a response of the marking medium to ambient conditions.
The detailed structure of the interrogator 26 will depend on the nature of the marking medium. For example, if the marking medium is a fluorescent ink that is used somewhere on the packaging or label, or a dye that is introduced into the product itself, the interrogator 26 may include a spectrometer. Or, in the case in which the marking medium is a radioactive material, the interrogator 26 will include a radiation detector. Or, if the marking medium relies on nucleic acid sequences, the interrogator can implement an appropriate test to identify the sequence.
The interrogator 26 measures the attribute associated with the marking medium and provides that information to a comparator 28 . Meanwhile, the reader 24 provides the serial number to the comparator 28 . The comparator 28 then determines whether the serial number and the response correspond to each other. If they do, the comparator 28 outputs a signal indicating that the merchandise unit 8 appears to be genuine. Otherwise, the comparator 28 outputs a signal indicating that the merchandise unit 8 appears to be a counterfeit. In either case, a human operator would encounter difficulty ascertaining a relationship between the serial number 8 and the attributes of the marking medium. As a result, it is difficult to effectively counterfeit the merchandise unit 8 .
Once a merchandise unit 8 is marked as described herein, with both a serial number 9 and a marking medium having an attribute that corresponds to the serial number 9 , counterfeiting becomes more difficult. No longer can the counterfeiter expect to deceive by simply copying a serial number 9 . Instead, the counterfeiter would be led to incorporate, into the merchandise unit 8 , a marking medium having a physical attribute that corresponds to the serial number 9 . Since the relationship between the serial number 9 and the attribute is not readily discernable by examining the merchandise unit 8 , the counterfeiter would encounter difficulty in successfully manufacturing a counterfeit merchandise unit 8 having the appropriate properties.
In some embodiments, the comparator 28 provides the serial number 9 as an argument to a function. The resulting value of the function is then compared with the value of the attribute. Or, the comparator 28 can inspect a look-up table keyed to either the serial number itself or to a function that accepts an electronic product code as an input and uses that number as an index to a look-up table. The look-up table can be stored locally, for improved performance. Or, the look-up table can be stored remotely, for example at the central server 18 , for enhanced security. Similarly, the evaluation of a function that accepts the serial number and the measured attribute value can take place locally, for enhanced performance, or remotely, at a central server 18 , for enhanced security.
For additional security, one can provide two or more marking media, each having an attribute with a relationship to the serial number. A merchandise unit 8 in this case would be deemed authentic only if the values of all the attributes stand in the correct relationship to the serial number. | A system for authenticating a merchandise unit includes a memory for storing an electronic product code obtained from and identifying the merchandise unit, and a sensor for detecting an attribute of a marking medium associated with the merchandise unit. The system is configured to output data representative of the attribute and the identity of the merchandise unit. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is an anchoring device especially designed to be used with an extensometer.
2. Description of the Prior Art
The concept of using retaining rings that are placed in grooves of a member to be retained so that the rings expand outwardly to anchor the member is known. The United States patent to W. G. Tilton (U.S. Pat. No. 502,686) shows this arrangement wherein there are grooves in one member and also grooves in a shaft coupling that is retained thereon. Normally the retaining rings are compressed (page 1, line 42) or loaded--presumably by hand, pliers, etc.-- and then held by the outer coupling until the sets of grooves of the coupling and member are aligned to coincide as one is moved relative to the other. Then the compressed loaded rings spring outwardly to anchor the members together.
Another reference (U.S. Pat. No. 929,979 to H. W. Pleister) discloses expanders 17 mounted in a slot 12 and a split ring 22 used to hold the expanders together in handling and shipping. Still other reference (U.S. Pat. No. 2,388,841 to D. W. Goodwin) discloses a spring shoe 60 with a set screw 71 to vary the friction (page 2, lines 62-73). A split ring with holes 23 used to receive tools to move the ring is disclosed in U.S. Pat. No. 2,491,306 to R. Feitl. Two U.S. patents--U.S. Pat. Nos. 3,535,750 and 3,698,278 to J. R. Metz and W. H. Trembley, respectively--disclose the idea of an outwardly biased locking member which is actuated by a pull device.
Perhaps the closest prior art to applicant's invention is the U.S. Pat. No. 2,712,952 to K. I. Lundgren. Therein a resilient ring 1 has holes at lugs 2 to receive the bolts 3. As the nuts 5 on the bolts are tightened the ring becomes fixed in the grooves 8. The FIG. 6-8 embodiment uses recesses 18 in the ring to lock it in cooperation with the bolt 19 (column 2, lines 21 et seq.)
Although the prior art discloses many of the essential features of the present invention, it fails to suggest or disclose the totality thereof or most of them used for the same or a similar purpose. None discloses an anchor body which is locked in a borehole by a preloaded resilient member placed in a groove of the anchor body which member has provision to hold the member in a loaded position by a pullable retaining member extending outside the borehole and unload the member by actuating the retaining member. None discloses a similar system useable with a extensometer anchor that is placed in a mine borehole and simply actuated by pulling a member located outside of the borehole.
SUMMARY OF THE INVENTION
My invention relates to an anchoring device which is actuated by pulling a retaining member. The retaining member is normally mounted so that it holds a resilient loaded member in a compressed position within the groove of an anchor body which body is to be anchored within a borehole. A connecting rod allows the anchor or anchors, as the case may be, to be classified as a single or multipoint extensometer.
The primary object of this invention is a simple, inexpensive, easily actuated borehole anchor.
More particularly, it is to provide a mining borehole anchor with these characteristics actuated by pulling a member outside of the borehole, and wherein the anchor is attached via a connecting rod or rods to an extensometer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial cross-sectional exploded view of the preferred embodiment of the invention.
FIG. 2 shows how the FIG. 1 embodiment would typically be employed in a single extensometer set up within a mine borehole.
FIG. 3 is a slight modification to the anchor shown in FIG. 1 for use with a multipoint extensometer.
FIG. 4 depicts how the FIG. 3 embodiment could be set up in a mine borehole.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is an exploded partial cross-sectional view of the preferred embodiment of my invention. Essentially it consists of the solid cylindrically shaped metal or polymer anchor body 1 having two generally parallel and identical transverse grooves 3 extending around its outer surface. Perpendicular to these grooves are two paralled holes that run in the longitudinal direction and intersect therewith and extend from the bottom to the top of the anchor body. Depending on what it is mounted, the anchor body has some type of mount attaching provision such as the lower center hole shown with its threaded set screw connection 7.
To anchor the anchor body in a mine borehole two identical resilient C-shaped retaining rings 9 may be used. Each of these rings is generally C shaped and therefore, opened at one sector which has two enlarged nubs. This construction allows the ring to flex in a plane cutting its major extent. The rings are sized and shaped to fit, when compressed, into the body's grooves. Near each of the enlarged opened ends or nubs of each ring is an aperture 11 extending through its nub and of about the same diameter as the holes 5. Complementary sized in diameter is an elongated U-shaped cotter pin 13 which fits into the holes 5 from the bottom of the anchor's body in its longitudinal direction and extends upwardly so that its two legs pass through each of the grooves 3 and its bight portion faces towards the open end of the mine borehole.
When in an operative mode the cotter pin fits into the hole 5 and extends through the two grooves 3. It also extends through the two holes 11 of each ring, which ring is seated in each of its respective grooves 3. In order to get the rings into the respective grooves, the lower ring is compressed so that the normally spaced apart holes 11 are aligned with holes 5. Next, the upper ring is compressed in a similar manner and properly aligned and seated in the upper groove. Then the cotter pin is pushed further to cause its legs to extend through the aligned hole 11 of the compressed upper ring. This procedure leads the two rings so that they will unload to expand outwardly in the borehole to bind firmly therein when the pin is pulled downwardly. A chain 14 which extends from outside the borehole can be attached to the bight of the cotter pin to pull the pin downwardly and out of the holes 5 and 11 to set the anchor. Support rod 15 with its internal threads mounts the anchor body at its threads 7. Support rod 15 provides the axial thrust to hold the anchor in place while cotter pin 13 is being pulled.
FIG. 2 shows how the FIG. 1 embodiment would typically be employed as a single anchor in a mine borehole 17. The transverse diameter of the anchor's body is selected so that it is slightly less than than the diameter of the borehole that has been previously drilled. Routinely this would be 1, 11/4 or 13/8 inches. After the cotter pin is pulled to allow the loaded rings to unload and expand outwardly against the borehole wall, as shown, the body is anchored. Downwardly depending from the anchor body is the mounted connecting rod 15. If the anchor is sufficiently deep in the borehole a second connecting rod 19 connected by a set screw connection to the first rod may be used. Connected to this second rod is a roof level anchor 21 having a shell section 23, a washer 25, a bolt head 27, and a reference surface 29. The washer, bolt head and its reference surface, all are located outside of the borehole at the mine's roof 31.
The roof level anchor, which may be used with my invention, is a double shell expansion borehole anchor set in place by rotating the bolt passing through the device. The washer prevents the anchor bolt head from entering the borehole. The upper end of the roof anchor has a vertical internally threaded hole (not shown) which allows the externally threaded free end of rod 19 to be connected. Normally the reference surface 29 on the bottom of the bolt head is 1/2 to 1 inch below the lower end of the roof level anchor.
Below the reference is a dial gage readout unit 33 having a resolution of 0.001 inch and a plunger 35 with a possible 5 inch stroke. This type of plunger mechanism does not return to a zero position after a reading has been made. Readings are taken by pulling out the plunger, positioning it in the hole in the lower anchor against the end of the connecting rods, and then pushing upward on the gage to bring it into contact with the end of the roof level anchor bolt. In this way the gage readings correspond to the distance in inches between the rod end and the anchor reference surface. Repeated recorded readings when compared after a period of time tell by their difference the roof movement between the upper and lower anchors. The gage can be removed from the roof level anchor to read the dial gage, and readings can be taken in up to 10 feet of headroom from floor level using a dial gage extension tube 37.
The single point C-anchor 1 illustrated in FIGS. 1-2 has been used to make routine on-site measurements of roof bed movements in room and pillar mines. The anchor body 1 may be made of a plastic cylinder and the rods 15 and 19 may be made of aluminum for rust resistance and light weight. The FIG. 3-4 multipoint embodiment shares many of the same components with the FIG. 1-2 embodiment. For ease in understanding common components in FIGS. 3-4 have been designed with the same numbers primed.
The anchor body 1' of FIG. 3 is basically the same as FIG. 1 excepting for the way it provides for its mount to a magnets and a support rod. It has two parallel identical grooves 3', two vertical parallel holes 5', two retaining rings 9', and a cotter pin 13'. Extending completely through the vertical extent of the anchor body is a hole 39 adapted to allow the guide tube 41 to slide through. At the top portion of the holes is the enlarged recessed portion 43 which can receive the seated ring magnet 45 and allow the tube to pass through it. When several anchors are used, five in the example depicted, the multipoint extensometer of FIG. 4 can be achieved. Each of the five anchors (1A to 1E) are constructed as is the anchor of FIG. 3. The uppermost hollow aluminum guide tubes 41 has a plastic end cap 47 to protect it from dirt and moisture. As before, to anchor the system in the borehole 17 a special cotter pin is pulled via a chain to cause the retaining rings for each anchor to spring out to engage the sides of the borehole. A setting tool (not shown) consisting of a rigid tube provides the axial thrust to hole the anchors in place while the cotter pin 13 is being pulled. The setting tool is removed after the anchor is set. Normally several separate guide tubes 41 are joined together in tandem to form the central guide for the flexible probe 53. Nearer to where the extensometer exists from the borehole is the roof level anchor 23', then, further down, the nut 49 having an internal thread 51, the flexible probe 53, and at, the borehole's beginning, the probe insertion tool 55. The reading's taken with the probe relate to the positions of the ring magnets 45 of each anchor. These magnets would encircle their respective tubes 41 along the length of the borehole and, in FIG. 4, would be at a five different spaced positions. It is the variations in these readings, recorded at different times, which allow the state of the roof mining operation for this multipoint extensometer to be determined. A remote digital readout unit (not shown) connected to the probe's wires can record positional changes to 0.001 of an inch.
It should be clear that many modifications can be made to the disclosed features and yet still stay within the scope and extent of my invention. For example, the number of anchor units useable with the FIG. 4 multipoint extensometer could be increased or decreased depending on the needs of the user, the materials used to construct the various parts could be varied, the shape of the ring retaining cotter pin could change, the number of retaining rings could vary, and the way the anchor body is mounted to the rod or tube could be different. None of these possible modifications or others should be used to limit the invention which is to be measured only by the claims which follow. | An extensometer anchor for use in a mine borehole. The anchor has an anchor body that, when in an operative mode, is placed in the borehole. Extending at least partially around the outer surface of the body are one or more grooves whose major plane is generally perpendicular to the length of the borehole. Seated within each groove is a compressible resilient anchor member, like a ring, which remains loaded by a retaining device, such as a cotter pin, extending through it. Upon being pulled from outside of the borehole, the retaining device unloads the compressed anchor which then moves to expand outwardly in the borehole and firmly anchor the anchor body and attached extensometer within the mine borehole. | 4 |
BACKGROUND
Applicant is not aware of any system capable of telescopically extending and retracting an outrigger shoe for construction equipment, such as, backhoe loaders.
OBJECTS AND FEATURES
A primary object and feature of the present invention is to provide a system for providing a range of ground positions to position the shoe of an outrigger so that the operator of the construction equipment can select the preferred ground position.
It is a further object and feature of the present invention to provide lateral movement of construction equipment where the outriggers are in the stabilizing position.
A further primary object and feature of the present invention is to provide such a system that is safe, efficient, trustworthy, inexpensive and handy. Other objects and features of this invention will become apparent with reference to the following descriptions.
CROSS REFERENCE TO RELATED APPLICATIONS
Not applicable.
SUMMARY
Disclosed is a system to stabilize a construction vehicle having a frame and a pair of stabilizing legs with ground-engaging shoes at the ends of the legs. The stabilizing legs pivotally connect to the frame on substantially opposing sides, so that the stabilizing legs pivot upwards to a stowed position and pivot downwards to a stabilizing position where the shoe engages the ground. Further, the stabilizing legs telescope between a retracted position and an extended position. The retracted position locates the shoe closer to the vehicle and the extended position locates the shoe further from the vehicle. A pair of hydraulic cylinders connect to the respective stabilizing legs to power the telescopic movement of the stabilizing legs between the retracted position and extended position.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a perspective view that illustrates a backhoe loader with an outrigger engaged with the ground after being extended to a location further from the vehicle.
FIG. 2 shows a top, diagrammatic view that illustrates a backhoe loader positioned near a ditch requiring extension of an outrigger to cross the ditch.
FIG. 3 shows a top, diagrammatic view that illustrates a backhoe loader positioned near a ditch after translating the backhoe over the ditch by retracting the extended outrigger and extending the retracted outrigger.
FIG. 4 shows a cross-sectional side view that illustrates the outrigger in the stowed, retracted position.
FIG. 5 shows a cross-sectional side view that illustrates the outrigger in the stowed, extended position.
FIG. 6 shows a cross-sectional side view that illustrates the outrigger in the stabilizing, retracted position.
FIG. 7 shows a cross-sectional side view that illustrates the outrigger in the stabilized, extended position.
FIG. 8 shows a schematic view that illustrates a hydraulic circuit to retrofit pre-existing construction equipment with the telescoping outrigger.
DETAILED DESCRIPTION
The present Telescoping Outrigger Systems will now be discussed in detail with regard to the attached drawing figures, which were briefly described above. In the following description, numerous specific details are set forth illustrating the Applicant's best mode for practicing the Telescoping Outrigger Systems and enabling one of ordinary skill in the art to make and use the Telescoping Outrigger Systems. It will be obvious, however, to one skilled in the art that the present Telescoping Outrigger Systems may be practiced without many of these specific details. In other instances, well-known manufacturing methods, mechanical engineering considerations, hydraulic circuit considerations, fluid dynamics principals and other details have not been described in particular detail in order to avoid unnecessarily obscuring this disclosure.
FIG. 1 shows a perspective view that illustrates backhoe loader 110 with outrigger 120 that may include a stabilization leg engaged with ground 130 after being extended to a location further from backhoe loader 110 across ditch 140 . System 100 shows how outriggers on backhoe loaders can extend and retract hydraulically. That is, system 100 shows how outriggers can telescope their length to provide positioning of shoe 125 across a range of ground locations to permit the operator to place shoe 125 on stable ground. Hydraulically telescoping outriggers can be helpful when shoe 125 would otherwise be positioned inside or along the edge of the ditch that the backhoe loader digs.
For example, as shown in FIG. 1 , backhoe loader 110 uses the bucket 150 to dig a ditch 140 in the ground 130 between building 160 and a terminus, (which is not shown), such as the street, or utility connection. It is desirable to dig ditch 140 to extend close to both building 160 and the terminus using backhoe loader 110 (and not digging manually, for example, using shovels). One way to dig ditch 140 using backhoe loader 110 would be to begin digging at the terminus and proceed toward building 160 . As the ditch approaches building 160 , backhoe loader 110 would be turned around to complete the ditch (and to avoid running into the building) by digging outwardly from the building back toward the ditch 140 .
Without telescoping outriggers, backhoe loader would likely place the outrigger inside the ditch (that is, not properly engaged with ground), or, immediately next to the ditch where the ground may not be stable. Without telescoping outriggers, the backhoe loader operator might need to re-position or repeatedly re-position the backhoe loader to avoid an undesirable placement of the outrigger shoe. Without the telescoping outriggers, the backhoe loader might be required to refill a portion of the ditch in order to place the outrigger stably.
As shown, backhoe loader 110 could avoid these problems. Backhoe loader 110 shows outrigger 120 extended beyond ditch 140 to place shoe 125 beyond ditch 140 . Without extending, outrigger 120 might be placed in ditch 140 . This shoe 125 placement relieves the need to reposition backhoe loader 110 , which may improve efficiency, for example, because the time spent repositioning the backhoe loader could be saved. This shoe 125 placement relieves the need to partially fill in ditch 140 , which may save time and improve safety, for example, because the time spent partially filling in the ditch could be saved and because more stable ground could be selected for placement of the shoe of the outrigger.
By allowing a wider range of placements of the shoe 125 , safety can be improved, for example, because a more stable location for placing the shoe 125 may be selected by the operator. The telescoping outrigger maintains many of the existing benefits of backhoe outriggers generally. For example, the outriggers remain stowable for easy transportation of the backhoe rigger.
Further, when the backhoe loader is used on uneven ground, the use of telescoping outriggers can provide additional positioning of the backhoe loader and placement of the shoe of the outrigger.
As shown in the exploded portion A of FIG. 1 , the outrigger 120 can be telescoped (that is, extend or retract along a range of ground positions) and moved between stowed/stabilized positions using hydraulic cylinders. Hydraulic cylinder 127 moves outrigger 120 between a stowed position and a stabilizing position. Hydraulic cylinder 129 is shown positioned inside outrigger 120 . Hydraulic cylinder 129 extends or retracts the length of outrigger 120 , because outrigger 120 has two mating portions that slide along the long axis.
Backhoe loader 110 has a bucket 150 for digging and excavating on one end. Backhoe loader 110 has a loader 170 on the other end for conveying materials into transportation trucks. Backhoe loader 110 prepares for excavation by lowering loader 170 and both of its outriggers 120 , as shown, to stabilize the backhoe loader 110 while the bucket 150 moves, swings, and scoops during excavation. If necessary outriggers 120 may be telescoped to select a desirable or stable ground position for shoe 125 . Backhoe loader 110 excavates by swinging bucket 150 out to engage the ground by extending the stick and boom 190 , and scooping up earth, which can be picked up and placed into piles of dirt 180 , as shown.
The construction vehicle may be any suitable mechanical excavator with bucket and hinged boom, such as, the bucket loader (or front-end loader) shown in FIG. 1 , for backhoe loader 110 . Alternately, construction vehicle may be an excavator with features like removable buckets, removable loaders, etc. The stabilizing leg may be any suitable stabilizing beam such as rigger shown in FIG. 1 , for outrigger 120 . The frame may be any suitable vehicle chassis, such as the body of the backhoe loader shown in FIG. 1 . The tractor may be any suitable prime mover, such as the engine enclosed in the backhoe loader shown in in FIG. 1 .
The backhoe bucket may be any suitable excavating-scoop such as the shovel-scoop shown in FIG. 1 , for bucket 150 . The loader bucket may be any suitable bucket conveyor for loading materials, such as the wide scoop shown in in FIG. 1 as loader 170 . The shoe may be any suitable ground-engaging member, such as the friction gripper shown in FIG. 1 for shoe 125 . The stick and boom may be any suitable hinged boom, such as the pivoting, two-beam hydraulically controlled boom shown in FIG. 1 as stick and boom 190 .
The hydraulic cylinder may be any suitable linear hydraulic motor, such as the mechanical actuator that provides a unidirectional force with a unidirectional stroke, shown in FIG. 1 for hydraulic cylinder 127 and hydraulic cylinder 129 .
FIG. 2 shows a top, diagrammatic view that illustrates backhoe loader 110 positioned near ditch 140 requiring extension of an outrigger to cross ditch 140 . FIG. 3 shows a top, diagrammatic view that illustrates backhoe loader 110 positioned near ditch after translating the backhoe over ditch 140 by retracting extended outrigger 122 and extending retracted outrigger 121 .
Now turning to FIGS. 2 3 together, these figures show that the operator of backhoe loader 110 may translate backhoe loader 110 from side to side by simultaneous extending one outrigger and retracting the other outrigger, as shown. FIG. 2 shows outrigger 121 ′ in the retracted position and outrigger 122 ′ in the extended position. In both FIG. 2 and FIG. 3 , loader 170 may be lowered to the ground position and is providing a third point of stabilization with the ground. This arrangement may be desirable because it would position the ground engaging end of outrigger 122 beyond ditch 140 . Between the positions of the backhoe loader 110 shown in FIG. 2 and FIG. 3 , operator would simultaneously extend outrigger 121 and retract outrigger 122 . FIG. 3 shows the outrigger 121 ″ in the extended position and outrigger 122 ″ in the retracted position.
The result is that backhoe loader has moved predominately sideways, which can be seen by the movement of pivot 155 . Bucket 150 is attached to the stick and boom which is attached to backhoe loader 110 at pivot 155 . Pivot 155 allows bucket 150 to swing from side to side. In FIG. 2 , pivot 155 ′ is positioned well to one side of ditch 140 , as shown. In FIG. 3 , pivot 155 ″ is positioned substantially over top of ditch 140 , as shown. Further, FIG. 3 shows that the wheels of backhoe loader may be positioned over ditch 140 , as well. That is, the lateral translation of the backhoe loader may allow the backhoe loader to reach positions and placements that may not be reached by driving on backhoe loader's wheels. This arrangement may have the further advantage of saving time by aligning the in-and-out scooping motion of bucket 150 (along the hinged stick and boom) with ditch 140 , as shown in FIG. 3 , which may aid in efficiency of excavation, ease of operation, or provide other advantages.
Loader 170 may rotate over (or slide across) the ground to accommodate the predominately sideways motion of the backhoe loader 110 . This can be seen by the change in angle of the loader 170 relative to ditch 140 , as shown between FIGS. 2 3 .
FIG. 4 shows a cross-sectional, side view that illustrates outrigger 200 in the stowed, retracted position. FIG. 5 shows a cross-sectional side view that illustrates outrigger 200 in the stowed, extended position. FIG. 6 shows a cross-sectional side view that illustrates outrigger 200 in the stabilizing, retracted position. FIG. 7 shows a cross-sectional side view that illustrates outrigger 200 in the stabilized, extended position.
Now, considering FIGS. 4, 5, 6 , 7 together, the various extreme (that is, fully-extended or fully-contracted) positions of outrigger 200 can be seen. Outrigger 200 connects to frame 210 , as shown. The medial end of outrigger 200 pivotally connects to frame 210 at joint 292 , as shown. The medial end of hydraulic cylinder 270 pivotally connects to frame 210 at joint 294 , as shown. The distal end of hydraulic cylinder 270 pivotally connects to outrigger 200 at joint 298 , as shown. This arrangement of joints 292 , 294 , and 298 with outrigger 200 and hydraulic cylinder 270 allows outrigger 200 to rotate between a stowage position and a stabilization position. These pivoting connections may be made by pins.
Outrigger 200 pivotally connects to shoe 230 at joint 296 , as shown, which allows shoe 230 to engage the ground at a varying angle. This pivoting connections may be made by a pin. Alternately, the shoe may be fixedly connected to the outrigger.
Outrigger 200 includes external member 250 and internal member 240 , as shown. External member 250 may be disposed around internal member 240 to allow internal member to slide in and out along the long axis. Hydraulic cylinder 260 may be disposed inside of internal member 240 and fixedly connected to the distal end, as shown. Hydraulic cylinder 260 may be disposed inside of external member 250 and fixedly connected to the medial end, as shown. This arrangement of external member 250 , internal member 240 and hydraulic cylinder 260 allows outrigger 200 to extend and retract, that is, it allows telescoping along the long axis of outrigger 200 . The external member 250 , internal member 240 and hydraulic cylinder 260 may be designed to be sufficient to overcome the forces generated during swinging, scooping and otherwise operating the bucket on the stick and boom, for example, selection of the materials and design may include factors such as modeling of mechanical forces, advances in materials technology, advances in hydraulics or fluid dynamics, economic considerations, etc.
The beams may be any type of slidably-mating beams, such as the mating cylinders shown in FIGS. 4, 5, 6 , 7 for external member 250 and internal member 240 .
Alternately, the external member and internal member may be reversed, with the internal member connected to the frame and the external member connected to the shoe. Further alternately, the hydraulic cylinder may be disposed along the outside of the outrigger. Yet further alternately, the members may be inter-mating in any fashion that allows sliding or extension/contraction along the long axis. In some embodiments, the joint between the stowage/stabilization cylinder and the outrigger may be desirable on the portion/beam/member that is immediately pivotally connected to the frame.
FIG. 8 shows a schematic view that illustrates hydraulic circuit 300 to retrofit pre-existing construction equipment with a pair of telescoping outriggers. For pre-existing construction equipment, a kit may be provided to retrofit with telescoping outriggers. This kit would include two telescoping outriggers, of the type shown in FIGS. 4, 5, 6 , 7 . The kit could also include sufficient controls to operate the two new hydraulic cylinders, that is, control valve, lines, and manual valves for the placement in cab. The kit would also include installation instructions (to describe the installation steps) and an operating manual (to describe operation of the telescoping outrigger after installation).
This kit would be sold as an aftermarket solution. Kits would be assembled using parts with appropriate dimensions for the make, model, and/or year of construction equipment. The outrigger would mount to the pre-existing machine frame pin bores. The outrigger arm would house a separate control valve, which would allow the telescoping circuit to be operated by the pre-existing stow/stabilize hydraulic circuit.
Installation would begin by removal of the original (non-telescoping) outrigger. The hydraulic cylinder (for stow/stabilize hydraulic circuit) would be left attached to the construction equipment. Next, the new telescoping outrigger would be attached to the frame of the construction equipment, which includes a hydraulic cylinder for extend/retract hydraulic circuit. Finally, the extend/retract cylinder would be connected to the existing hydraulic circuit by modifying the circuit to function as shown in FIG. 8 .
FIG. 8 shows a hydraulic circuit that permits use of the existing (stow/stabilize) hydraulic controls to alternate between controlling the pair of hydraulic cylinders that stow/stabilize and controlling the pair of hydraulic cylinders that extend/retract (telescope). The original hydraulic lines from head end 310 and rod end 315 of the stow/stabilize hydraulic circuit may be connected into the diverter valve 320 , which may be the diverter valve provided with the telescoping outrigger as part of a kit.
Hydraulic oil may flow into diverter valve 320 from the head end 310 and rod end 315 , as shown. Diverter valve 320 contains control spools 321 , double check valves 327 , and pressure reducing valve 325 , as shown. Upon activation of the hydraulic circuit, pilot oil would be produced through pressure reducing valve 325 , as shown. This pilot oil would flow to control valves 330 located in cab 340 . Hydraulic fluid may be any suitable incompressible fluid, such as hydraulic oil.
Control valves 330 are detented. When control valves 330 are in a normal position, control valves 330 would block oil and allow only operation of the stow/stabilize hydraulic circuit of the stow/stabilize hydraulic cylinder 350 . This allows moving the telescoping outrigger between the stowed position and the stabilizing position.
When the operator would like to operate the telescoping hydraulic circuit, the operator would change the position of the detented control valves 330 . The pilot oil from the control valves 330 would then travel back to diverter valve 320 allowing the position of spools 321 to re-direct the pump flow to the extend/retract hydraulic circuit of the telescoping cylinder 360 .
In some embodiments, diverter valve 320 may be mounted within or upon the telescoping outrigger. In some embodiments, it may be preferable to provide quad check valves or multiple check valves to prevent movement of the stow/stabilize cylinder while the extend/retract hydraulic circuit is in use.
The hydraulic controller may be any suitable mechanical, pilot, or electro-hydraulic controls, such as the diverter valves shown in FIG. 8 as diverter valve 320 .
For installations into new construction equipment, the original equipment manufacturer may include a control circuit as part of the original construction equipment. This control circuit would be operated from the cab by the operator and allow extension and retraction of the telescoping outriggers, either independently, or simultaneous (as desirable to create side-to-side movement described in FIGS. 2 3 , above). These controls may be mechanical, pilot, or electro-hydraulic controls, or other types of controls.
Although Applicant has described Applicant's preferred embodiments of this invention, it will be understood that the broadest scope of this invention includes modifications and implementations apparent to those skilled in the art after reading the above specification and the below claims. Such scope is limited only by the below claims as read in connection with the above specification. Further, many other advantages of Applicant's invention will be apparent to those skilled in the art from the above descriptions and the below claims. | A system to stabilize a construction vehicle having a frame and a pair of stabilizing legs with ground-engaging shoes at the ends of the legs. The stabilizing legs pivotally connect to the frame on substantially opposing sides, so that the stabilizing legs pivot upwards to a stowed position and pivot downwards to a stabilizing position where the shoe engages the ground. Further, the stabilizing legs telescope between a retracted position and an extended position. The retracted position locates the shoe closer to the vehicle and the extended position locates the shoe further from the vehicle. A pair of hydraulic cylinders connect to the respective stabilizing legs to power the telescopic movement of the stabilizing legs between the retracted position and extended position. | 4 |
This application claims benefit under 35 U.S.C. §119(e) to U.S. Ser. No. 60/588,112, filed Jul. 15, 2004, entirely incorporated by reference.
FIELD OF THE INVENTION
The present invention relates to generating and sending mailers, or more generally any targeted, printed graphic communication, composed of a document of one or more pages enclosed in a matching envelope. More specifically, the present invention relates to the design or creation of a mailer or mailers at one location and the manufacturing and dispatch or posting of said mailer(s) at a second location.
BACKGROUND OF THE INVENTION
Conventionally, to create a letter or mailer one would locally print a document such as letter text or other message on letterhead or a form, insert the document into an envelope, affix postage and enter into a delivery/postal service. This would require having materials on hand such as pre-printed flat paper stock and pre-converted and pre-printed envelopes which become obsolete and require storage, a printing device such as a typewriter or laser printer with related supplies and power, postage, and labor to execute the printing, assembly and posting of the mailer.
Commercial lettershops typically produce letters for clients in larger batches on pre-printed stock with long lead times and little, if any, variation in graphic presentation. Mailer production can be outsourced to a secretarial service, especially for the production of mailers one at a time, however this is still produced on pre-printed stationery which must be inventoried for potential demand.
There is now emerging an industry to create “printing on demand” in order to reduce the need to inventory pre-printed stock and to increase the flexibility of designs for production. Currently, several providers of letter on demand services have emerged such as Zairmail or Postcards.com. These providers either do not use envelopes, simply manufacturing postcards instead, or they use a generic double window envelope to enclose a document and show delivery and return address information. Usually their production systems are not economical in very small batches, especially one unit. If they do provide one unit production it involves “hand work” and is much more costly to produce than with the current invention. The use of a double window envelope conveys little or no graphic information on the carrier envelope and gives the mailer a distinctively limited and “pre-fabricated” look.
SUMMARY OF THE INVENTION
The present invention consists of a system and method for a) accepting demands from a user through a computer to automatically manufacture a physical mailer consisting of a custom printed document enclosed within a matching custom printed envelope, b) retaining a digital record of the mailer for archiving, and c) posting the mailer into the postal system or other delivery network.
The present invention may accept mailer demands for production from various channels. A mailer consists of any combination of static text and images and variable text and images to be merged and printed onto the mailer's constituent parts. Mailers can be processed in quantities of from one to any quantity.
The present invention differs from any prior art in that it constructs an outside envelope to match, on a unit by unit basis, a simultaneously constructed interior document. It then verifies that the intended mailer's constituent document and envelope match into a complete set, inserts the document into the envelope, and then re-verifies finished production and assignment to a postal presort tray or the like for entry into a delivery logistics system such as the US Postal Service or private carrier such as Fedex or DHL, and also for reporting back to the business process management software programs and thence to the user.
The present invention provides several advantages over the prior art. For example, the user does not need to keep any letterhead, forms or envelopes on hand. Also, the user does not need a printer on hand nor does the user does not need to keep any postage on hand. Production can be demanded from anywhere at any time. Additionally, production economies of scale inure to the small user's benefit because all production is digital at a scale of one unit regardless of the total number of units or the total number of users. Production can be fully executed and verified in a matter of minutes or faster. Business process management software does not allow for any missing units from all units demanded. And, since all production is digitally managed, including document composition, a record of each unit including a digital image, time stamp, etc. is maintained as long as desired. Demand can be automated from any number of processes, for example, from customer relationship management (CRM) software. Further, components can be modified at will. Design libraries, templates and tools may be applied to automatically or semi-automatically generate mailers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing showing the functional components of one embodiment of the present invention, beginning with the User and following the process of demanding, manufacturing and posting a mailer.
FIG. 2 is a schematic drawing showing the principle functional components of an embodiment of the present invention, emphasizing the availability of multiple delivery channels from the invention and the varied nature of different potential users and channels into the invention's functionality.
DETAILED DESCRIPTION OF THE INVENTION
As used herein, “Mailer” means a document of one or more pages enclosed within an envelope and targeted to an individual recipient. “Document” means a custom printed graphic communication, usually printed on flat paper or other substrate. “Envelope” means a carrier for the document custom printed to match the document and converted, i.e., folded and glued, into a typical envelope configuration. “Form Set” means a defined physical configuration exclusive of graphic design or data to be manufactured and assembled. “Production Queue” means all the individual units demanded within a particular form set for manufacture and posting in a certain batch. “Mailer Demand” means input into the invention from the user that specifies the desired form set and all the graphical data and targeting or addressing data necessary to generate the desired mailer. “Business Process Management & Workflow Control Software” means an integrated suite or system of existing industry standard computer programs and custom written computer programs that manages the several functions between the User and the invention, and among the several data processing and manufacturing operations that collectively comprise the invention. “Pattern Recognition Artificial Intelligence” means a system typically using video cameras to capture an image of a printed item or a portion of that item for comparison with an image from another printed item using a computer program to evaluate the imagery and verify that the images correspond appropriately within the manufacturing process.
Following is a more detailed explanation of the principle components of the present invention. In reference to FIGS. 1 & 2 , a user 1 may send a demand to the system for a mailer (any envelope enclosed document). The user 1 could be any natural person, business or other party, or even an automated system using means including, but not limited to, an internet site, web portal or telephone interface. Users 1 could access the invention from any physical location given some channel, e.g., web servers, web sites, email, FTP transfer, or print drivers to communicate appropriately. For example, the user 1 could also be an automated process creating demands through a web server, e.g., a sales transaction at an automated point-of-sale system triggers a demand for a “thank you” letter.
An integrated suite of computer programs represented in Business Process Management/Workflow Control Software (BPM) 2 accepts the user's 1 mailer demand and control the production processes, e.g., document composition, job queuing, pattern recognition verification, production reporting, etc. The BPM software 2 can use currently available commercial software programs in conjunction with custom written computer programs utilizing existing and emerging protocols such as the Print On Demand Initiative's (PODI) Personalized Print Markup Language (PPML) and The International Cooperation for the Integration of Processes in Prepress, Press and Postpress Organization's (CIP4) Job Description Format (JDF) among others to help in the coordination and automation of the invention's functions. The actual configuration of the BPM 2 functions may be more or less complex depending upon the type and sophistication of the user 1 . In its simpler form it need only specify a particular mailer and enter it into the production queue. In a more complex form it could link to design tools, templates, libraries or other data sources for various types of applications and include other functions such as archiving electronic versions of demanded mailers.
Blank paper is printed with any image by a digital press in one pass 3 . For example, a signed letter on letterhead would have the letterhead logo and address information, the letter text, and the sender's signature all printed at once thereby eliminating any need to inventory pre-printed stock or to handle a sheet of paper more than once for imaging or printing. Recently available industrial digital presses such as Xerox's iGen3 or Kodak's NexPress provide print quality rivaling offset lithography. These printers can physically accommodate several types and sizes of paper or other substrates for printing and for inclusion within the production queue for a given form set. This is also an example of how the BPM 2 functions would need to specify the appropriate paper stock through an application program interface (API) to the printer controller software.
The document and the envelope may be printed on a single sheet of paper such that the document envelope blank needs to be cut apart from the larger sheet 4 . Additionally, designs that “bleed” (image printed past the finished document's edge and then trimmed) may be trimmed at this point. Documents may be more economically printed in multiple sets on one larger sheet, e.g., “2-up”, and then cut into finished document sheets. This device could be a programmable cutter such as manufactured by Polar or Itec. Material could move from one physical lettershop or bindery type operation to the next in a fully automated fashion or by hand or by some combination of methods.
The trimmed letter is folded to be inserted into an envelope 5 . Letters of multiple sheets are accumulated before folding. At this point it is necessary to employ pattern recognition/artificial intelligence 13 to ensure accurate matching and accumulating prior to folding. Devices such as this are currently manufactured or integrated by Bowe/Bell & Howell, MBO and others.
To custom print the envelope, blank paper is printed with any image by a digital press in one pass 6 . The envelope stock's image could cover the entire envelope surface with graphics and could contain any information such as a return address and logo “corner card”, recipient's address, and postage indicia. As with the document printing 3 , the envelope is printed all at once and simultaneously with the document, thereby eliminating any need to inventory pre-printed stock or to handle a sheet of paper more than once for imaging or printing. This would be handled by the same sort of printer used for printing the document.
The printed envelope stock is trimmed or die cut prior to conversion into a finished envelope using a standard type of commercial die cutter 7 .
The flat, digitally pre-printed envelope stock is converted, that is folded and glued, into a finished envelope 8 . None of the prior art is creating digital envelopes automatically and performing the next step at a unit by unit level instead of a pre-defined batch operation. The envelope conversion can be executed by machinery from such manufacturers as Winkler and Dunnebier or F. L. Smithe. By maintaining strict order integrity between the document and envelope stock within the production queue, the constituents of the mailer are aligned to be automatically combined at the next step.
The matching letter and finished envelope converge 9 . Pattern recognition artificial intelligence 13 verifies an accurate match of the corresponding components and the letter is inserted into the envelope. If there is not an accurate match the system will stop the manufacturing process and may re-demand the letter package. Bowe/Bell and Howell and Pitney Bowes currently manufacture suitable devices for this task. The finished letters are essentially ready to be mailed at this point, however it is desirable to do additional processing in order to verify that all mailer units demanded are present and accounted for, and also to organize for postal system work sharing, i.e., presorting, thereby earning maximum postal discounts.
Each completed mailer unit is identified by an automated sorter 10 using video capture and pattern recognition artificial intelligence 13 . The mailer is matched against the list of demanded mailers for the production queue in a computer database that is part of the business process management (BPM) 2 functions. Any missing letters are re-demanded by the BPM 2 software. Verified letters are sent by the sorter to appropriate sort bins for entry into the postal letter stream or other means of delivery and a report is made, including a time stamp, to the BPM 2 software. In this way a closed end loop and audit trail is integral to the BPM 2 functions so that users may be highly confident that their mailers were completed and mailed at a definite time. This feature is extremely useful for users 1 needing reliable verification of system fulfillment of mailer demands such as issuers of regulatory mandated letters, sales managers tracking employee communications, or many other applications. Such a sorter 10 also facilitates commingling of mailers from multiple users for maximum postal discounts. Bowe/Bell and Howell and Pitney Bowes currently manufacture suitable devices for this task.
The present invention's output can be sent to intended recipients through any number of delivery channels, e.g., USPS, FedEx, UPS, etc 11 . The delivery services can typically report to the user 1 certain delivery details, in which case the BPM module 2 which can relay data to the user 1 .
The intended recipient of the mailer 12 is the final stage of the process and can be any designated target of the user.
There are pattern recognition artificial intelligence nodes in the production sequence 13 at which verification of the presence of certain components or the finished mailer should be made. At these points video cameras scan each piece and verify a match or order sequence integrity within the production queue according to the computer program within the business process management and workflow control software 2 . This technology is available from Bowe/Bell and Howell or Lake Image Systems for integration with the BPM functions of the present invention.
FIG. 2 a shows a simplified diagram illustrating the various outbound channels available to the present invention and FIG. 2 b elaborates on some of the potential users and components of the control process.
The Mailer On Demand Engine 21 is composed of the integrated systems of software, hardware and manufacturing processes, schematically illustrated in FIG. 2 a, that control the invention's operations.
The potential outbound delivery channels 22 would typically be the postal service but it could also be private express organizations or electronic transmission.
The typical gateways 31 into the invention's functionality that accepts mailer demands are expected to be web portals and web servers which can be linked through any number of applications.
An important extension of the BPM 2 functions is the ability to digitally archive any mailers for review by the user 1 by employing a computer's disk storage memory used to store digital files of mailers demanded of the invention in a format such as Portable Document Format (PDF). Tags such as the date of manufacture of the mailer, date and time of entry into the postal stream, and date of entry at the destination delivery unit (DDU) can be attached to the digital version of the mailer for reference or audit purposes.
Another important extension or set of extensions from the BPM 2 software are the tools for the user 1 to access in designing, targeting, and scheduling the mailer 34 . These could be proprietary and custom software tools and databases or simply links to other resources for these purposes.
The present invention includes the methods and systems for transmitting the mailer demand to the processing system. The system uses many different forms of inputs into the system, including: web servers—XML or other data for predefined mailing templates; web servers—XML data and direct images from a customer's system; web servers—via Print Driver; FTP sites—similar to web servers. Data can be uploaded manually, using an FTP tool like Leech, or automatically from any kid of program. The web servers might store files into the same folders on the FTP site that are used for direct upload. Inputs could also include: websites—direct design and entry on a website; email—send attachments to, for example, Printlt@ The present invention.Net; print drivers.
One such method is a print driver that can be linked to popular software products such as Microsoft Word, WordPerfect, etc. The print driver collects the data required to make up a mailer demand and sends it to the Print Driver Web Server. The Print Driver Web Server is a special web server that expects input generated by a print driver distributed to users.
The present invention's control system is methodologically individualistic or unit focused, as opposed to a conventional batch orientation, in its application of pattern recognition artificial intelligence to automatically match components of the mailer, on a unit by unit basis, so that it is practical to demand and manufacture one unit at a time from multiple sources or users.
Many possible uses are for the present invention exist. Examples include, but are not limited to: retail transaction triggers CRM software to send a marketing letter; Cub scouts sending out a letter to everyone in a troop; agent based sales organization's agents send letters to clients; credit granting companies send “turn down” letters or other mandated communications; medical office sending out mailers to remind patients of appointments; and intercontinental or other long distance mail. Distance is physically eliminated except with respect to the recipient's proximity to a production center. | A method of generating a mailer on demand by receiving data for an envelope and a matching document in a computer, placing data for the envelope and the document in a production queue, generating the envelope using the data, generating the document using the data, automatically verifying the correct generation and sequence of the envelope, automatically verifying the correct generation and sequence of the document, removing any envelope or document if the verification process returns a false condition for correct generation or sequence in order to maintain order integrity of the production queue and automatically regenerating the incorrectly generated or sequenced piece and all other corresponding piece(s) of the mailer, and matching a verified envelope with a matching verified document and creating the mailer. | 6 |
RELATED APPLICATIONS
This Patent Application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application Ser. No. 60/221,363, filed Jul. 27, 2000, entitled “Lighting Control Using Speech Recognition.”
This application also claims the benefit under 35 U.S.C. §120 as a continuation-in-part (CIP) of U.S. Non-provisional Application Ser. No. 09/669,121, filed Sep. 25, 2000, entitled “Multicolored LED Lighting Method and Apparatus”, which is a continuation of U.S. Ser. No. 09/425,770, filed Oct. 22, 1999, now U.S. Pat. No. 6,150,774, which is a continuation of U.S. Ser. No. 08/920,156, filed Aug. 26, 1997, now U.S. Pat. No. 6,016,038.
This application also claims the benefit under 35 U.S.C. §120 as a continuation-in-part (CIP) of the following U.S. Non-provisional Applications:
Ser. No. 09/215,624, filed Dec. 17, 1998, entitled “Smart Light Bulb”, which claims the benefit of the following provisional applications:
Ser. No. 60/071,281, filed Dec. 17, 1997, entitled “Digitally Controlled Light Emitting Diodes Systems and Methods”; Ser. No. 60/068,792, filed Dec. 24, 1997, entitled “Multi-Color Intelligent Lighting”; Ser. No. 60/078,861, filed Mar. 20, 1998, entitled “Digital Lighting Systems”; Ser. No. 60/079,285, filed Mar. 25, 1998, entitled “System and Method for Controlled Illumination”; and Ser. No. 60/090,920, filed Jun. 26, 1998, entitled “Methods for Software Driven Generation of Multiple Simultaneous High Speed Pulse Width Modulated Signals”;
Ser. No. 09/213,607, filed Dec. 17, 1998, entitled “Systems and Methods for Sensor-Responsive Illumination”;
Ser. No. 09/213,189, filed Dec. 17, 1998, entitled “Precision Illumination”;
Ser. No. 09/213,581, filed Dec. 17, 1998, entitled “Kinetic Illumination”;
Ser. No. 09/213,540, filed Dec. 17, 1998, entitled “Data Delivery Track”;
Ser. No. 09/333,739, filed Jun. 15, 1999, entitled “Diffuse Illumination Systems and Methods”;
Ser. No. 09/742,017, filed Dec. 20, 2000, entitled “Lighting Entertainment System”, which is a continuation of U.S. Ser. No. 09/213,548, filed Dec. 17 , 1998, now U.S. Pat. No. 6,166,496;
Ser. No. 09/815,418, filed Mar. 22, 2001, entitled “Lighting Entertainment System”, which also is a continuation of U.S. Ser. No. 09/213,548, filed Dec. 17, 1998, now U.S. Pat. No. 6,166,496; and
Ser. No. 09/626,905, filed Jul. 27, 2000, entitled “Lighting Components”, which is a continuation of U.S. Ser. No. 09/213,659, filed Dec. 17, 1998, now U.S. Pat. No. 6,211,626.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to systems and methods for the programming of lighting, in particular to voice programming of lighting.
2. Description of Related Art
Known technology combines multiple light-emitting diodes LEDs in one or more packages with a microprocessor. This combination is provided in U.S. Pat. No. 6,016,038 the entire disclosure of which is herein incorporated by reference. This type of technology gives an enormous opportunity for control possibilities. The combination of the network and a controller allows the controller to access and control each of the devices on the network. This can be used to synchronize and coordinate more than one light to produce pleasing effects. Examples of such effects include the movement of color within a room, or the shift of a rainbow across the room or even the effect of the passage of time through the simulation of a sunrise and sunset across multiple lights in a room.
Turning lights on and off and then controlling the lights typically requires human interfaces that incorporate the use of standard devices such as hand or finger-actuated switches or knobs. Touch plates, switches, knobs, dials, sliders, rockers, and all manner of mechanical interfaces to electrical signals provide for control and manipulation of signals, which are then mapped to lighting changes. For colored lights, additional dimensions of representation and control complicate this. These include modification of hue, saturation or brightness or even temporal and geometric changes. This can include the modification of the rate of change of an effect or the effect itself.
SUMMARY OF THE INVENTION
In one embodiment, a simple control language based upon spoken words consisting of commands and values may be constructed and used to provide a common base for lighting and system control.
In another embodiment, a system for the control of color-based lighting through voice control may be presented. The system may be comprised of a transducer for taking in voice signals; a lighting system capable of controlling at least one lighting device wherein the lighting device is capable of producing multiple colors; and a computing device for converting the voice signals into signals that can be used by the lighting system to control said at least one lighting device.
In a further embodiment, a method for the control of color-based lighting may be presented. The method may comprise having a user speak a command in a syntax composed for use with a lighting system; translating the command into a signal to be used to control a lighting device, wherein the lighting device is capable of producing multiple colors, controlled by the lighting system; and using the signal to carry out an action on the lighting device, such that the action carried out corresponds to the command given.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 shows a block diagram of a voice controlled lighting system according to one embodiment of the invention.
FIG. 2 illustrates the lighting system of FIG. 1 coupled to a lighting network.
FIG. 3 illustrates a lighting device that can be used in voice controlled lighting systems according to embodiments of the present invention.
DETAILED DESCRIPTION
As shown in FIG. 1 , one embodiment of the invention comprises several elements including a transducer 3 , such as a microphone, which converts the acoustics of voice from the user 1 into an electrical signal. This electrical signal is then digitized and input into a computing device for processing. Speech recognition module 5 (which may be implemented in software) is then used to recognize the speech input and provide language output corresponding to the spoken words. This input becomes a command stream that is presented to a command interpreter 7 which then executes the command to the lighting control 9 and eventually the lights 11 .
FIG. 2 illustrates one possible arrangement of the lights 11 in accordance with an embodiment of the present invention. The lights 11 may be part of a network where each light has a unique address. The lighting control signals communicated from the lighting control 9 may include addressed data such that each of the individual lights 11 responds to commands corresponding to its particular address. In an embodiment, the particular light 11 may be chosen through a verbal command and the lighting control 9 may communicate instructions to the intended light 11 . In another embodiment, the lights may be arranged in groups or have group addresses. For example, if all of the lights 11 have a unique address, a set of unique addressed lights may be arranged in a group such that all of the lights in a group act as one. Several lights 11 may also be set to the same address to effectuate the grouping. One skilled in the art will appreciate that there are many methods for grouping lights 11 or other devices, so that the present invention is not limited to any particular method of grouping. Grouping the lights 11 can be useful in customizing the desired lighting effects. For example, several lights 11 may be grouped as a first address 20 , and several lights may be grouped as a second address 22 . The user may speak into a microphone 3 , or other transducer, and direct the commands to the grouping in address 20 . Upon identification and command language, the group of lights corresponding to address 20 may respond accordingly. The lights of address 20 may be lighting an archway for example while the lights of address 22 are lighting a wall of a building.
In one embodiment shown in FIG. 3 , a light 11 may include a processor 300 wherein the processor can receive commands through a data port 310 and control, in response to the commands, at least one LED 302 as indicated in FIG. 3 . In one embodiment, the processor may independently control multiple LEDs 302 , 304 , and 306 . This may be useful where the control of color changing lighting is desired. For example, the three LEDs 302 , 304 , and 306 may be red, green and blue and the processor may be able to control the output of each LED such that the emitted color from the light 11 changes. It should be appreciated that the present invention is not limited to use with lights configured as shown in FIG. 3 , as numerous other configurations are possible, including different numbers of LEDs or light sources other than LEDs.
If the speech is unintelligible or the command nonsensical, then the system can respond with an error message. This can take the form of an indicator including the lights themselves, a display, or, to keep the interface uniform, can be voice-generated output.
A number of speech recognition programs are available from a number of companies such as SpeechWorks, Dragon Systems, IBM and others. Some of these systems provide a modularity that allows developers to incorporate speech recognition in their platforms and systems. In an embodiment of the present invention, a standard microphone may be used to provide speech input to a computer-based system that takes that input, digitizes it and then uses a speech recognition component to provide commands. Because the grammar and syntax of the command set is known and the context is known, this winnows down the possibilities of interpreting the speech input a great deal. This then provides for a simpler interpretation process and allows the speech recognition module to deliver a compact ‘language’ for the Command Interpreter to execute.
In an embodiment, the command set provides for the concatenation of a few simple commands. The first is an attention getter for the system so that normal conversation doesn't result in unwanted interpretations. (Similar to when they say “Computer, <command>” on Star Trek.)
Commands can take the form of objects (e.g. a room, a specific light, a group of lights) and actions or values. These commands can be concatenated to form a full ‘sentence’ of description.
Examples:
<System call><object><value>
“Light Room redder”—results in incremental change in light output
“Light Room RGB 128 128 128”—results in light output with RGB values and default brightness.
“Light Desk warmer”—results in an incremental decrease in color temperature of a desk light.
All means for describing color can be used ranging from detailed technical means such as coordinates of the CIE diagram or Color Temperature values, to far more general ‘warmer’, ‘redder’, ‘darker’, ‘lighter’ values or turning on and off as well as commands to indicate duration and effects such as “Light Room Effect Rainbow.” In an embodiment, voice commands may be used to set a new effect. In an embodiment, the light may be set to a particular setting and that becomes a new default. Other examples of commands may include:
“Light Room Name Party” or “Light Room Name Romance” (depending on the desired mood)
Timing can also be set from such a construct: “Light Room Turn-on ten o'clock”
In an embodiment, the lighting effects may transition between addressed lights 11 or groups of lights 20 and 22 . For example, the effect or value of “effect rainbow” may initiate a lighting program that starts a first light 11 and then moves to a second light 11 . The first light 11 may cycle through the colors of the rainbow starting with the color blue and the second light 11 may also cycle through the same colors but the blue will be offset in time from the first light 11 such that it appears as though the light is moving through the room. One with ordinary skill in the art would appreciate that there are many lighting effects that can be generated on networked and non-networked lighting systems and the present invention is not limited in any way to a particular effect.
Color is visually represented in several ways including the CIE diagram and other diagrams such as hue wheels, or Munsell spaces or even Pantone colors. These visual representations can be used as a model for directing direction and change such as saying coordinates of a color, but a more natural way is to modify a color by directing it to be redder, darker, whiter, more saturated etc. Thus, a language and syntax can be provided for enabling simplification of the description of color effects, so that voice commands can be used to create a wide variety of such effects in a room or on an object.
Other commands can allow change until a ‘stop’ is reached or the color reaches a limit. For example, “House Room Darken” could begin to dim the lights until the command “Stop” is heard. If no command is heard the dimming would continue until the light turns off or reaches some limiting value.
As used herein, the term “LED” should be understood to include light emitting diodes of all types, light emitting polymers, semiconductor dies that produce light in response to current, organic LEDs, electro-luminescent strips, and other such systems. “LED” may refer to a single light emitting diode having multiple semiconductor dies that are individually controlled. It should also be understood that the term “LED” does not restrict the package type of the LED. The term “LED” includes packaged non-packaged LEDs, surface mount LEDs, chip on board LEDs and LEDs of all other configurations. The term “LED” also includes LEDs packaged or associated with material (e.g. a phosphor) wherein the material may convert energy from the LED to a different wavelength.
While the invention has been disclosed in connection with the preferred embodiments shown and described in detail, various modifications and improvements thereon will become readily apparent to those skilled in the art. Accordingly, the spirit and scope of the present invention is to be limited only by the following claims and their equivalents. | A system and method for the control of color-based lighting through voice control or speech recognition as well as a syntax for use with such a system. In this approach, the spoken voice (in any language) can be used to more naturally control effects without having to learn the myriad manipulation required of some complex controller interfaces. A simple control language based upon spoken words consisting of commands and values is constructed and used to provide a common base for lighting and system control. | 7 |
BACKGROUND OF THE INVENTION
The present invention is directed to filtration systems and, more particularly, to a system and method for removing contaminants from groundwater associated with underground natural gas wells, mining operations, and other environments.
It is often necessary to remove water from underground geological formations in order to release natural gas associated with the underground formations. Oftentimes, the formations are more than 1,000 feet below the surface of the earth. A typical formation can comprise several separate layers of the liquid and gas or can comprise a single large reservoir. A bore hole is drilled into the earth and passes through the different layers of the formation until the target layer is reached. The location and depth of the bore hole is carefully controlled because of the great expense associated with drilling the bore hole. In order to prevent collapse of the bore hole after drilling, it is usually lined with a casing along its entire length. The casing also helps to control reservoir pressure and protect surface water from contamination. The casing is cemented in place and sealed at the ground surface by a wellhead.
One or more pipes or tubes extend into the bore hole from the wellhead. One of the tubes is typically used to carry liquid to the surface. The internal pressure of many geological formations is often insufficient to naturally raise commercial quantities of the natural gas from the formation through the bore hole or does so at an inadequate flow rate. Oftentimes, a large volume of liquid is present in the underground formation and must be removed on a continuous basis in order to recover natural gas from the formation. An artificial lift system is used in conjunction with the tube(s) to remove the liquid from the underground formation. Currently, many different types of artificial lift systems are available to lift the liquid from the formation, the most common of which are progressive cavity pumps, beam pumps and subsurface gas lift (SSGL) systems.
No matter what artificial lift system is used, water retrieved from underground coal formations often contains contaminants such as iron and inorganic and organic sulfur compounds, manganese, sodium, barium, arsenic, and other trace metals, and coal fines. Some constituents indigenous to groundwater associated with underground coal seams, such as iron and manganese, are pH dependent, while other constituents, such as sulfur, are more oxygen dependent. These constituents typically exist in soluble forms in the groundwater. When the groundwater is ejected or pumped to the surface and exposed to air, iron, sulfur and manganese are oxidized, resulting in the deposition of insoluble forms and precipitate on contact surfaces causing discoloration. The precipitates may also impart foul taste and odor to the water.
Federal and state regulations dictate minimum water quality standards that must be met before water from underground formations, mines or other underground structures can be discharged into the environment. When such standards are not met, the environment may be adversely affected and gas production or other operations may be halted. Due to the excessive amounts of contaminants in the discharge water, many natural gas producers are experiencing difficulties in obtaining discharge permits from state agencies.
Prior attempts to filter the contaminated water have included activated carbon filters, capacitive deionization systems, and the like. The filters can become quickly clogged and therefore must be constantly monitored, cleaned and/or replaced, leading to great expense and reduced efficacy over time. This problem is exacerbated by the relatively large flow rates that must be accommodated. By way of example, a filtration system may be required to process approximately 100 gallons of groundwater per minute over a 24-hour period of time, depending on the number of wells associated with the filtration system, the volume of groundwater to be lifted from each well, and the frequency at which the groundwater is lifted. Thus, approximately 144,000 gallons or 3,429 barrels of groundwater may pass through the filtration system every 24 hours.
In addition, natural gas wells are typically located at remote locations where power from electrical grids may not be available. In such locations, the wells may be operated through wind, solar or gas powered generators. Accordingly, filtration systems at remote locations should require little or no electrical power to operate.
It would therefore be desirable to provide a filtration system that is capable of removing large amounts of contaminants from groundwater under large flow rates in a relatively quick and efficient manner without substantial degradation of the filtration system. It would also be desirable to provide a filtration system that requires little or no electrical power to operate.
SUMMARY OF THE INVENTION
According to the invention, a method is provided for removing contaminants from water that has a relatively low oxygen content with naturally occurring chemoautotrophic bacteria, and at least one of iron in the ferrous state and sulfide. The method comprises oxygenating the water and directing the oxygenated water to a filtration vessel. The filtration vessel has bio-filtration media with surfaces that are exposed to the oxygenated water. The chemoautotrophic bacteria propagate in the presence of the oxygenated water and at least one of the ferrous iron and sulfide. At least one of ferric iron and sulfate are deposited on the bio-filtration media as a by-product of the chemoautotrophic bacteria. At least one form of ferric iron and iron sulfate are precipitated in the presence of the oxygenated water. The water can then be removed from the filtration vessel and either discharged into the environment or directed to a secondary filtration stage.
Further according to the invention, a system is provided for removing contaminants from water that has a relatively low oxygen content with naturally occurring chemoautotrophic bacteria, and at least one of ferrous iron and sulfide. The system comprises an oxygenation vessel for oxygenating the water and a filtration vessel having first bio-filtration media with surfaces that are exposed to the oxygenated water. With this arrangement, at least one form of ferric iron and iron sulfate can be precipitated in the presence of the oxygenated water and can be deposited on the bio-filtration media as a by-product of the chemoautotrophic bacteria to thereby remove ferric iron and/or iron sulfate from the water.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The preferred embodiments of the present invention will hereinafter be described in conjunction with the appended drawings, wherein like designations throughout the drawings denote like elements, and wherein:
FIG. 1 is a schematic block diagram of a system for removing contaminants from water according to the present invention;
FIG. 2 is a schematic diagram of a system for removing contaminants from water according to the present invention and showing the system connected to a well head associated with an underground formation;
FIG. 3 is a schematic diagram of a system for removing contaminants from water according to a further embodiment of the present invention;
FIG. 4 is an enlarged perspective view of an aeration tower that forms part of the system of the present invention;
FIG. 5 is a top plan view of a filtration component that forms part of the system of the present invention;
FIG. 6 is a side elevational view of the filtration component; and
FIG. 7 is an exploded perspective view of a filtration tank that forms part of the system of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, and to FIG. 1 in particular, a system 10 for removing contaminants from groundwater according to the present invention is illustrated. The system 10 includes a first filtration stage 12 , 12 A that is connected between a well 14 and a waste removal stage 16 . The well 14 may be associated with an underground gas producing formation, such as an underground coalbed formation where groundwater is removed through an artificial lift system to recover methane gas. A second filtration stage 18 is preferably connected to the first filtration stage 12 , 12 A for removing particles that pass through the first filtration stage. The second filtration stage 18 is also connected to the waste removal stage 16 . As shown, clean water 20 exits from the second filtration stage for safe disposal in the environment or other uses. Alternatively, depending on the type and amount of contaminants to be removed from the groundwater, the second filtration stage may be eliminated, so that the water is directly discharged to the environment after the first filtration stage.
As will be described in greater detail below, and according to a preferred embodiment of the invention, the first filtration stage 12 , 12 A is constructed to extract relatively large amounts of iron, sulfur, manganese, coal fines and other relatively large particles that would otherwise plug up the second filtration stage 18 . Without the first filtration stage 12 , 12 A, the second filtration stage would require constant maintenance or would be rendered partially or wholly inoperative, and therefore would not be an economically feasible approach in and of itself.
The second filtration stage can be constructed to remove sodium, barium, arsenic, and other contaminants that may not be sufficiently removed by the first filtration stage. Many different types and configurations of filters and filter systems well known to those of ordinary skill in the art can be used for the second stage, such as reverse osmosis, ion exchange, and activated charcoal filters. According to a preferred embodiment of the invention, a Capacitive Deionization Technology (CDT) filter system is used for the second filtration stage 18 . In the CDT system, sheets of thin carbon aerogel material are formed into cells and placed at opposite boundaries of a flow path of the incoming water. By polarizing the cells, oppositely charged ions migrate to the oppositely charged sheets of aerogel material. A second filtration stage constructed in this manner can be controlled electronically through software, requires little power consumption to operate, and is easier to maintain than other filter systems. More details of the CDT system can be found in U.S. Pat. No. 5,425,858 issued to Joseph Farmer on Jun. 20, 1995, the disclosure of which is hereby incorporated by reference.
As shown in FIG. 2, the first filtration stage 12 is connected to the well 14 , such as a coalbed methane well, through an underground pipe 32 . The well 14 includes a well head 30 and a casing 34 that extends into a reservoir 36 of an underground formation 38 from the well head. The reservoir 36 may include groundwater 40 that must be removed before gas can be produced from the formation 38 . An artificial lift system 42 , such as a down-hole pump or the like, is connected to a production tube 44 , which is in turn connected to the underground pipe 32 . The artificial lift system 42 moves water from the underground reservoir 36 , through the tube 44 , and into the pipe 32 .
The first filtration stage 12 includes a chemical treatment system 50 that is connected to the underground pipe 32 , an aeration tower 52 located at a discharge end of the pipe 32 , and a filtration tank 54 connected to the aeration tower through a pipe 56 .
The chemical treatment system 50 includes a storage tank 60 containing oxidation media. A metering pump 62 is connected to the storage tank 60 through tubing 64 . An injection nozzle 66 extends between the underground pipe 32 and the metering pump 62 for delivering oxidation media to the water within the pipe 32 . A measurement electrode 68 extends into the pipe 32 downstream from the injection nozzle 66 for monitoring oxidation of the water within the pipe 32 . In addition to chemical oxidation, an air injector can be installed in the pipe 32 to assist in oxidizing the water, and thus the contaminants carried by the water.
Prior to treatment, groundwater 40 from the reservoir 36 can be sampled and analyzed for a variety of constituents including trace metals, non-metals and major ions. Particular attention can be focussed on the soluble levels of iron, sulfur and manganese, as well as the factors that affect their oxidation and removal from the groundwater, such as pH level, temperature, alkalinity, and the presence of catalysts. This information can then be used to establish the initial oxidant concentration and application rate for the groundwater. The set point of the chemical metering pump 62 can be determined from the desired water quality parameters. Oxidant can then be continuously metered into the groundwater through the nozzle 66 and monitored with the electrode 68 . Preferably, the electrode 68 generates a millivolt (mV) signal from the reduction-oxidation (redox) process. The signal can then be compared to the set point of the metering pump and the set point can be automatically adjusted to provide an adjusted oxidant dosage. According to a preferred embodiment of the present invention, the oxidant is potassium permanganate (KMnO 4 ). The chemical reactions for iron and manganese oxidized with potassium permanganate are as follows:
3Fe 2 +KMnO 4 +7H 2 O3Fe(OH) 3 (s)+MnO 2 +K + +5H +
3Mn 2 +KMnO 4 +2H 2 O5MnO 2 (s)+2K + +4H +
Following the oxidation stage, the groundwater is directed to the aeration tower 52 through the underground pipe 32 . The underground pipe 32 helps to maintain the groundwater at an ideal temperature level, as will be described in greater detail below.
With additional reference to FIG. 4, the aeration tower 52 includes a generally cylindrical housing 70 that can be constructed of polyvinyl chloride (PVC) or other material well known to those of ordinary skill in the art. The housing 70 includes a continuous wall 72 that forms a hollow interior 74 . Openings 76 are formed in the wall circumferentially around the housing 70 and extend between the hollow interior 74 and the outside of the housing. A catch basin 78 surrounds the housing 70 for catching groundwater that may flow through the openings 76 . The height of the catch basin is approximately equal to the height of the housing 70 , as shown in FIG. 4 . Alternatively, the height of the catch basin can be much smaller, as shown in FIG. 2 . An enclosure 79 (FIG. 2) constructed of fiberglass or other material, may surround the tower 52 .
Bio-filtration media, shown here as a plurality of bio-media balls 80 , are located in the hollow interior 74 of the housing 70 , and preferably substantially fill the hollow interior.
As shown in FIGS. 5 and 6, each of the bio-media balls 80 according to an exemplary embodiment of the invention is constructed of a plastic material and has a plurality of axially extending pins 82 , 84 , 86 , 88 , 90 , and 92 arranged on concentric, annular rings or webs 94 , 96 , 98 , 100 , 102 , and 104 , respectively. Arms 106 extend radially from a centrally located rod 108 and are formed integral with the annular webs for holding the webs together. The pins are preferably integrally formed with their respective annular webs and progressively increase in length from the outer annular web 94 to the inner annular web 104 . By way of example, the bio-media balls are about 1.5 inches in diameter and preferably include over one hundred pins. The pins provide both mechanical and biological filtration by physically blocking larger particles and by promoting the growth of bacteria over the relatively large surface area of the pins. The pins also help produce turbulence as the groundwater flows over the bio-media balls, aiding in the oxygenation process of the groundwater and the precipitation of contaminants on the surfaces of the pins. Although the bio-media balls have been shown as having a particular configuration, it will be understood by those of ordinary skill in the art that other bio-media configurations can be used. The bio-media balls are commonly used in freshwater and saltwater wet/dry systems and pond filters for breaking down toxic ammonia produced by aquatic life into less toxic nitrates and are commercially available from Lee's Aquarium & Pet Products (www.leesaqpet.com). Suitable bio-media balls and other bio-media configurations are commercially available from petsolutions® (www.petsolutions.com).
According to the invention, the bio-media balls are used for precipitating iron and sulfur on their surfaces, and are compatible with relatively high flow rates of the groundwater. Iron and sulfur bacteria are diverse in their taxonomy. Their primary usefulness and importance to the present invention is their ability to transform ferrous iron to ferric iron. These bacteria obtain energy by the oxidation of iron from the ferrous to the ferric state. Discharge from coal-bed methane wells is typically basic, although it may be acidic, and has carbonates, iron and sulfur forms. Ferric iron readily combines with the carbonates and sulfur to form precipitates which can be settled. The ferric form of iron is precipitated as ferric hydroxide. Water borne iron is available in many natural water systems, such as coal bed methane wells.
The bacterial oxidation of ferrous iron to the ferric form is generally as follows:
4Fe 2+ +O 2 +4H + 4Fe 3+ +2H 2 O
In the present invention, one or more bacteria of the chemoautotrophic type, including members of the bacteria genus Thiobacillus ferrooxidans, Leptospirillum ferrooxidans, Sulfolobus acidocaldarius, Sulfobacillus thermosulfidooxidans , and other bacteria exhibiting similar environmental, ecological, and/or metabolical properties, may be present in the groundwater from coalbed methane gas wells, drainage from mining operations, and other environments. Oxidation of ore and iron by a consortia of bacteria generally takes place at a higher rate than with pure cultures, and is ideally suited to the system and method of the present invention since more than one type of bacteria may be present in the groundwater. The consortia may include mixtures of bacterial genera, species and types that can react synergistically to produce impacts to the microenvironment. Thus, it is believed that no single genera or group of organisms is exclusively responsible for the process.
Groundwater from coalbed methane wells offer several key energy and nutritional circumstances that provide an acceptable and productive growth environment. Before the groundwater is oxygenated, the bacteria are in a substantially dormant state, and do not require nor consume iron and sulfur, and thus do not deposit the iron and sulfur byproducts of such consumption onto surfaces. Where oxidative and reductive environments change in the presence of iron and the large surface area of the bio-media balls, selected bacterial populations propagate. The relatively large surface area of the bio-media balls provide an excellent surface for the bacteria to adhere to and on which to deposit the contaminants, such as ferric hydroxide, sulfur, arsenic, and so on, from the water. Iron, sulfur and manganese may also precipitate independent of the bacteria and settle on the surfaces of the bio-media balls or at the bottom of the tower and tank. The propagation of the selected bacterial populations increases at a logarithmic rate, which in turn increases the metabolic requirements. The iron and sulfur present in the oxygenated ground water are therefore consumed at a higher rate, leading to increased filter efficiency.
Although the tower 52 is primarily used for aeration of the groundwater 40 , the ferrous iron may be precipitated and deposited on the surfaces of the bio-media balls 80 .
The tower 52 , by way of example, may be constructed to continuously oxygenate ground water at a flow rate of approximately one hundred gallons per minute. For such a flow rate, the tower 52 can have an inside diameter of approximately 20 inches and a height of approximately 6.5 feet. The openings 76 are about one inch in diameter and are spaced on about two inch centers within the same row. The openings of adjacent rows can be spaced on one foot centers. It will be understood by those of ordinary skill in the art that these dimensions are given by way of example only, and can greatly vary depending on numerous factors, including the size and type of the bio-media, the water flow rate and the amount of oxygen and/or contaminants already present in the water.
Once the groundwater 40 exits the aeration tower 52 , it is directed, preferably under pressure from the aeration tower 52 and gravity, to the filtration tank 54 .
Referring now to FIG. 7, the tank 54 has a tank housing 120 with elongate side walls 122 and 124 and end walls 126 and 128 connected at opposite ends of the side walls. A floor 130 extends between the side and end walls to form an hollow interior 132 . A lip 134 extends around the upper periphery of the tank housing 120 for supporting a lid 136 . The lid 136 encloses the hollow interior 132 and normally prevents the ingress of foreign matter into the tank housing 120 and the egress of water and contaminants from the tank housing.
Flow control weirs 140 , 142 , 144 , 146 , and 148 are positioned in the hollow interior 132 of the tank housing 120 and extend between the side walls 122 and 124 to divide the interior into an entrance chamber 150 , filtration chambers 152 , 154 , 156 , and 158 , and an exit chamber 159 . The weirs 140 , 144 and 148 have a bottom edge 160 that is spaced from the floor 130 so that groundwater and contaminants can flow between the floor 130 and the weirs 140 , 144 and 148 . Likewise, the weirs 142 and 146 have an upper edge 162 spaced from the lid 136 when closed so that groundwater and contaminants can flow between the lid 136 and the weirs 142 and 146 . In this manner, the groundwater must pass through the tank in a serpentine fashion from the entrance chamber 150 to the exit chamber 159 , as represented by dashed line 164 . The entrance chamber 150 and exit chamber 159 help to slow movement of the groundwater. An L-shaped flange extension 166 is attached to the end wall 128 below an exit pipe 168 to ensure that the filtered groundwater completely fills the exit pipe 168 .
A filtration basket 180 is removably positioned in each of the filtration chambers 152 , 154 , 156 , and 158 . Each filtration basket 180 includes a housing 182 that is sized to be received in one of the filtration chambers. The housing 182 has end walls 184 , 186 and side walls 188 , 190 that extend between the end walls. A floor 192 extends between the side and end walls to form a hollow interior 194 . Each wall has an opening 196 with a screen 198 located in the opening. A plate 200 extends generally horizontally across each opening to support the screen 198 . Bio-media balls 80 are located in the hollow interior 194 of each basket 180 to deposit, precipitate and filter out contaminants from the ground water, as previously described with respect to the aeration tower 52 . A lid 202 is hingedly connected to the housing 182 and includes an opening 196 with a screen 198 formed in the opening. The lid 202 holds the bio-media balls 80 in the basket during use and can be opened for emptying and filling the basket.
In use, the groundwater from the aeration tower 52 first enters the entrance chamber 150 to slow the water velocity prior to filtration. The water then flows upwardly through a first basket 180 in the first filtration chamber 152 , followed by flowing downwardly through a second basket 180 in the second filtration chamber 154 , flowing upwardly through a third basket 180 in the third filtration chamber 156 , then flowing downwardly through a fourth basket 180 in the fourth filtration chamber 158 , as shown by the dashed line 164 . Finally, the water flows upwardly through the exit chamber and is discharged out of the tank to either the environment as surface drainage or to the second filtration stage 18 (FIG. 1 ). For a flow rate of one hundred gallons per minute, by way of example, the filtration tank 54 is preferably dimensioned to hold about 2,000 gallons of liquid, and each basket 180 is dimensioned to hold approximately 25,000 bio-media balls 80 of 1.5 inch diameter. With this example, the groundwater is in the filtration tank 54 for approximately twenty minutes, which in many cases gives enough time for the contaminants in the groundwater to be deposited as bacteria by-products onto the bio-media balls and other surfaces, and allows iron and sulfur precipitates, coal fines, sediment, and other relatively large particles in the groundwater to settle to the bottom of the baskets 180 . In this manner, a substantial amount of contaminants are removed from the water.
As the bio-media balls become coated with metal oxides, the coatings serve as catalysts for oxidation and removal of additional precipitate from the groundwater. According to a preferred embodiment of the invention, the bio-media balls are pre-coated with metal oxides before being placed in the baskets 180 and inserted into the tank to expedite their effectiveness. When the surface area of the bio-media balls 80 is reduced to a predetermined value due to the build-up of metal oxides and other contaminants, the baskets can be removed and the bio-media balls replaced. The spent bio-media balls can then be cleaned and then recoated with metal oxide and stored for later use. Alternatively, a substantial portion of the spent bio-media balls can be cleaned, such as seventy-five percent, with the remaining portion being used as catalysts during the next filtration cycle. The bio-media balls can be cleaned by cracking the oxide layers through movement and/or vibration, and/or exposing them to surfactants. Larger particles that have collected in the bottom of the baskets, such as iron and sulfur precipitates, coal fines, debris, and the like, can also be removed from the baskets during removal of the spent bio-media balls.
Although four filtration chambers and baskets are shown, and a particular number of bio-media balls have been indicated for each basket, it is to be understood that these numbers can vary greatly, as well as the size of the filtration tank, baskets and chambers, depending on the amount of contaminants in the water, the water flow rate, the desired filtration time, and other factors.
With reference now to FIG. 3, a first filtration stage 12 A according to another preferred embodiment of the invention is shown, wherein like parts in the previous embodiment are represented by like numerals. The first filtration stage 12 A is similar in construction to the first filtration stage 12 (FIG. 2 ), with the exception that the chemical treatment system 50 is removed. Surprisingly, it has been found that that the first filtration stage 12 A is more efficient in removing contaminants from the groundwater than the first filtration stage 12 . With the exemplary first filtration stage 12 A as described, it has been found that approximately 80% iron and 66% manganese can be removed from the groundwater, with no visible staining when the groundwater is discharged into the environment. The first filtration stage 12 A thus greatly improves the quality of the water before it is discharged into the environment or directed to the second filtration stage 18 . By removing a substantial portion of the iron precipitates and other related contaminants at the first filtration stage 12 A, the operating and maintenance costs for the second filtration stage can thus be greatly reduced.
It is to be understood that the various representative dimensions and capacities for the aeration tower, filtration tank, filtration baskets, and the bio-media balls as shown and described are given by way of example only. The representative dimensions and capacities illustrate only the relative proportions of the preferred embodiment of the system. It is to be understood that the overall dimensions, including the relative proportions and capacities, can be varied without departing from the spirit and scope of the present invention.
In each of the described embodiments, the groundwater can be inoculated with a particular type of bacteria or with a consortium of bacteria species, preferably before the groundwater enters the aeration tower. In this manner, bacteria beneficial to the filtration of a particular contaminant or group of contaminants, that otherwise may not be naturally present in the groundwater, can be used to remove the contaminants. The bacteria may be retrieved from other water sources or cultured in a laboratory or the like. The metering pump 62 (FIG. 2) can be used to infuse the bacteria into the groundwater.
It may also be desirable to remove the bacteria after the groundwater exits the filtration tank 54 and prior to entering the second filtration stage. The bacteria can be removed by infusing an oxidizer into the filtered groundwater, which burns the cell walls of the bacteria and destroys them. Preferably, Ozone is injected into the filtered groundwater since it will naturally diffuse into the atmosphere downstream of the injection point. However, other oxidizers can be used, such as chlorine or potassium permanganate.
While the invention has been taught with specific reference to the above-described embodiments, those skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the invention. Thus, the described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope. | A system and method for removing contaminants from water that has a relatively low oxygen content with naturally occurring chemoautotrophic bacteria, ferrous iron, manganese, sulfide, and other contaminants. The system comprises an oxygenation vessel for oxygenating the water and a filtration vessel having bio-filtration media with surfaces that are exposed to the oxygenated water. The chemoautotrophic bacteria propagate in the presence of the oxygenated water and deposit certain of the contaminants on the bio-filtration media as by-products. The contaminants are also precipitated in the presence of the oxygenated water and settle on the bio-filtration media in at least the filtration vessel. A secondary filtration stage can further remove contaminants from the water that were not sufficiently removed by the first filtration stage. | 2 |
TECHNICAL FIELD
The invention pertains to microstructure devices, methods of forming a microstructure device and a method of forming a MEMS device.
BACKGROUND OF THE INVENTION
Advancements in the field of semiconductor processing have resulted in the development of micro-machining and micro-electromechanics. More specifically, micro-electromechanical systems (MEMS) have been fabricated using semiconductor processing techniques to form electrical and mechanical structures using a given substrate.
For example, some micro-electromechanical systems devices include cantilevers or other microstages of silicon which may be configured to be electrostatically actuated for various applications. Such MEMS devices may be used in exemplary applications including gyroscopes, accelerometers, tunable RF capacitors, digital mirrors, etc.
Exemplary MEMS devices including cantilever structures are described in Zhang and MacDonald, A RIE Process For Submicron, Silicon Electromechanical Structures , Cornell University (IOP Publishing Ltd. 1992), the teachings of which are incorporated herein by reference. A process is proposed in this publication for the formation of silicon cantilever beams with aluminum side electrodes for use as capacitor actuators. This prior art method is depicted herein as FIGS. 1-11 .
Referring initially to FIG. 1 , a silicon substrate 10 , a silicon dioxide (SiO 2 ) layer 12 , and photoresist 14 are depicted. Layer 12 is formed to a thickness of 150 nm and photoresist 14 is patterned as illustrated.
Referring to FIG. 2 , a mask defined by photoresist 14 shown in FIG. 1 is utilized to pattern silicon dioxide layer 12 .
Referring to FIG. 3 , plural trenches 16 are formed in substrate 10 utilizing reactive ion etching (RIE) according to the prior art process.
Referring to FIG. 4 , thermal oxidation next occurs resulting in insulative layer 12 a covering sidewalls and lower surfaces of trenches.
Referring to FIG. 5 , contact windows 20 are opened over a surface of substrate 10 to enable desired electrical connection through insulative silicon dioxide layer 12 a to substrate 10 .
Referring to FIG. 6 , an aluminum layer 22 is formed by physical vapor deposition (PVD) to a thickness of 400 nm. The sputtered aluminum layer 22 forms side electrodes 23 within trenches 16 .
Referring to FIG. 7 , photoresist 24 is formed upon the structure of FIG. 6 and is patterned to cover portions of aluminum layer 22 including side electrodes 23 .
Referring to FIG. 8 , portions of the aluminum layer 22 upon the bottom surfaces of trenches 16 are patterned as shown using photoresist 24 .
Referring to FIG. 9 , portions of silicon dioxide layer 12 within the bottoms of trenches 16 are patterned following patterning of aluminum layer 22 .
Referring to FIG. 10 , photoresist 24 of FIG. 9 is stripped from the structure.
Referring to FIG. 11 , a cantilever 26 is released by isotropically etching silicon substrate 10 utilizing a fluorinated plasma (i.e., SiF 6 ). Further details regarding the depicted prior art process are also described in U.S. Pat. No. 5,198,390, the teachings of which are incorporated herein by reference.
Modifications to this aforementioned process have been proposed by M. T. A. Saif and Noel C. MacDonald, as described herein.
In this modified process, the silicon release step described above with respect to FIG. 11 is performed prior to aluminum metallization. More specifically, the silicon is etched similar to FIG. 3 and plasma enhanced chemical vapor deposition PECVD or tetraethylorthosilicate (TEOS) deposition thereafter occurs. The resultant oxide is patterned, the silicon release etch is performed, and aluminum is deposited. This described process eliminates the need to pattern the metal or open contact holes.
The conventional described processes have associated drawbacks. Initially, the reactive ion etching of silicon substrate 10 shown in FIG. 3 typically results in a rough or scalloped etch profile. The roughness is duplicated in subsequent oxide and aluminum layers formed upon the sidewalls of trenches 16 . Such roughness or scalloping compromises the functionality of the resultant device inasmuch as the area of the electrodes or capacitor plates is not well controlled. Further, such roughness or scalloping limits the scalability of the structure.
Also, the single crystal reactive etching and metallization process of the prior art contains multiple oxide and aluminum deposition and etch steps resulting in increased complexity.
In addition, the utilization of SF 6 plasma to release the silicon cantilever 26 attacks the aluminum side electrodes 23 . Although the aluminum is attacked weakly by this chemistry, such may lead to further undesirable non-uniformity of electrodes 23 .
Accordingly, there exists a need to provide improved processing methodologies and structures which avoid the drawbacks associated with the prior art methodologies and devices.
SUMMARY OF THE INVENTION
The invention pertains to microstructure devices, methods of forming a microstructure device and a method of forming a MEMS device.
According to one aspect, the invention provides a microstructure device comprising: a semiconductive substrate; a monolithic microstructure device feature coupled with the semiconductive substrate, and wherein at least a portion of the microstructure device feature is configured to move relative to the semiconductive substrate; and a conductive structure provided directly upon at least a portion of the microstructure device feature.
A second aspect of the invention provides a microstructure device comprising: a semiconductive substrate; a microstructure device feature coupled with the semiconductive substrate, and wherein at least a portion of the microstructure device feature is configured to move relative to the semiconductive substrate; and a titanium nitride structure coupled with at least a portion of the microstructure device feature.
Another aspect of the invention provides a microstructure device comprising: a semiconductive substrate having a sidewall; a microstructure device feature having a sidewall adjacent to and spaced from the sidewall of the semiconductive substrate, and wherein at least a portion of the microstructure device feature is configured to move relative to the semiconductive substrate; and opposing conductive electrodes individually provided directly upon one of the sidewall of the semiconductive substrate and the sidewall of the microstructure device feature to form a capacitor.
According to another aspect, a method of forming a microstructure device comprises: forming a monolithic microstructure device feature coupled with a semiconductive substrate; providing a conductive structure directly upon at least a portion of the microstructure device feature; and releasing the microstructure device feature from the semiconductive substrate.
Another aspect provides a method of forming a microstructure device comprising: forming a microstructure device feature coupled with a semiconductive substrate; depositing a conductive structure upon at least a portion of the microstructure device feature using chemical vapor deposition; and releasing at least a portion of the microstructure device feature from the semiconductive substrate.
According to an additional aspect, the invention provides a method of forming a microstructure device comprising: providing a semiconductive substrate; forming a microstructure device feature using the semiconductive substrate and comprising material of the semiconductive substrate; and providing a conductive structure directly upon at least a portion of the semiconductive material of the microstructure device feature; and releasing the microstructure device feature from the semiconductive substrate.
Another aspect provides a method of forming a microstructure device comprising: forming a plurality of trenches within a semiconductive substrate to define a microstructure device feature, the semiconductive substrate and the microstructure device feature having opposing sidewalls; forming respective conductive structures directly upon respective portions of the opposing sidewalls of the semiconductive substrate and the microstructure device feature; and undercutting at least a portion of the microstructure device feature to release the portion of the microstructure device feature from the substrate to permit the portion of the microstructure to move relative to the substrate.
Yet another aspect provides a method of forming a MEMS device comprising: providing a semiconductive substrate; forming plural trenches having bottom surfaces within the semiconductive substrate to define a MEMS device feature between the trenches, the semiconductive substrate and the microstructure device feature having opposing sidewalls; depositing a titanium nitride layer using chemical vapor deposition upon at least a portion of an upper surface of the semiconductive substrate, upon the opposing sidewalls of the semiconductive substrate and the microstructure device feature to form capacitor electrodes, and upon the bottom surfaces; removing the titanium nitride layer upon the bottom surfaces of the trenches; and undercutting at least a portion of the microstructure device feature to release the portion of the microstructure device feature from the substrate to permit the portion of the microstructure device feature to move relative to the substrate.
Other devices and methods are also disclosed herein according to other aspects of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-11 depict sequential process steps of a conventional fabrication methodology.
FIGS. 12-20 depict exemplary sequential process steps according to aspects of the present invention.
FIG. 21 is a perspective view of an exemplary device embodying aspects of the present invention and fabricated according to the process of FIGS. 12 - 20 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Exemplary process steps of the present invention are illustrated in FIGS. 12-20 and are described with respect to the formation of microstructure devices. One example of a microstructure device 31 is depicted in FIG. 21 comprising a capacitor actuator of a micro-electromechanical systems (MEMS) device or a microsystems technology (MST) device. Microstructure devices include micromachined components or structures. The depicted microstructure device 31 comprising a MEMS or MST device is exemplary and the present invention may be utilized to fabricate other devices, including other microstructure devices.
Referring to FIGS. 12-20 , an exemplary methodology for fabricating features of microstructure devices is illustrated in sequential process steps. Microstructure device feature refers to a micromachined component or structure of a microstructure device configured to move relative to a substrate. One example of a microstructure device feature is a microstage of substrate material comprising a cantilever, gear, valve, actuator, sensor or other structure of a MEMS device.
Referring initially to FIG. 12 , a microstructure device assembly 30 is depicted at an initial process step. Assembly 30 includes a substrate 40 comprising substrate material 41 utilized to form subsequent devices. An exemplary substrate 40 is a semiconductive substrate, such as monocrystalline silicon. The present invention encompasses other substrates, materials, and/or layers in addition to monocrystalline silicon, such as polycrystalline or amorphous silicon, silicon carbide, gallium arsenide, for example.
Semiconductive substrate comprises any construction of semiconductive material, including, but not limited to, bulk semiconductive materials such as a semiconductive wafer (either alone or in assemblies comprising other materials thereon), and semiconductive material layers (either alone or in assemblies comprising other materials) including silicon on insulator (SOI) and bonded wafer configurations, for example. Substrate refers to any supporting structure, including, but not limited to, the semiconductive substrate described above.
A layer of insulative material 42 , such as thermal silicon dioxide, is formed upon substrate 40 in the depicted embodiment. Further, photoresist material 44 is patterned upon insulative material 42 as illustrated to form a desired microstructure device feature in the subsequent process steps described below.
Referring to FIG. 13 , the silicon dioxide material 42 is patterned using photoresist material 44 of FIG. 12 forming a mask 43 . Photoresist material 44 has been stripped from assembly 30 in FIG. 13 .
Referring to FIG. 14 , a plurality of trenches 46 are formed within substrate 40 as defined by mask 43 . Trenches 46 are formed within substrate 40 using reactive ion etching in one example. The depicted trenches 46 are deep trenches individually having a depth of approximately 5-50 microns and a width of approximately 0.25-5 microns. Individual trenches 46 include plural sidewalls 47 and a bottom surface 49 .
Referring to FIG. 15 , mask 43 , comprising the insulative material 42 , is etched from substrate 40 of assembly 30 following the formation of deep trenches 46 .
Referring to FIG. 16 , a layer of conductive material 48 is provided over substrate 40 . According to the described embodiment, conductive material 48 comprises titanium nitride (TiN). An exemplary CVD process of titanium nitride is performed at pressures of approximately 5-10 Torr, temperatures of approximately 680° C., and utilizing the following gases TiCl 4 at 350 sccm, NH 3 at 100 sccm and nitrogen at 1000 sccm.
Other conductive materials, such as tungsten, tantelum nitride, or other refractory metals, may also be utilized. An exemplary tungsten deposition process is described in Takayuki Ohba, Chemical - Vapor - Deposited Tungsten for Vertical Wiring , pp. 46-52 (1995), incorporated herein by reference. Conductive material 48 is selected in accordance with aspects of the invention such that direct deposition of the material upon substrate material 41 will not result in an adverse reaction which compromises device fabrication or operation.
According to embodiments wherein titanium nitride is utilized, the titanium nitride conductive material 48 is deposited in a single layer using chemical vapor deposition (CVD) with TiCl 4 as a precursor in the described exemplary process. Conductive material 48 is formed to a thickness of approximately 300 nm in accordance with the illustrative embodiment. Deposition of TiN provides a conformal coating of conductive material 48 having substantially smooth outwardly exposed surfaces even when deposited over a rough substrate, such as sidewalls 47 of individual trenches 46 .
Referring to FIG. 17 , a mask 50 of photoresist material 52 is formed upon conductive material 48 of assembly 30 as depicted. The photoresist is deposited and patterned to form the depicted mask 50 over substrate 40 .
Referring to FIG. 18 , conductive material 48 is patterned utilizing mask 50 . Such patterning removes conductive material 48 from bottom surfaces 49 and adjacent portions of sidewalls 47 of trenches 46 .
Referring to FIG. 19 , photoresist material 52 comprising mask 50 of FIG. 18 has been stripped from assembly 30 leaving remaining conductive material 48 outwardly exposed.
Referring to FIG. 20 , substrate material 41 of substrate 40 adjacent to lower portions of trenches 46 is next isotropically etched using conductive material 48 as a mask. A SF 6 plasma silicon release etch chemistry is utilized according to one processing methodology to etch substrate material 41 . Other etch chemistries are possible including XeF 2 , for example. The depicted process step releases and defines a microstructure device feature 54 of microstructure device 31 . Microstructure device feature 54 is intermediate trenches 46 as shown.
Referring to FIG. 21 , further details of assembly 30 comprising microstructure device 31 are illustrated. Microstructure device feature 54 is coupled with substrate 40 and forms a cantilevered extension from substrate 40 in the described exemplary embodiment. Microstructure device feature 54 comprises monolithic substrate material 41 which extends from substrate 40 . In the depicted arrangement, microstructure device feature 54 is coupled with substrate 40 at a first end 58 while a second end 60 is configured to move relative to substrate 40 . Conductive material 48 is formed directly upon the monolithic microstructure device feature 54 according to aspects of the invention.
As shown, microstructure device feature 54 and substrate 40 have opposing sidewalls 47 adjacent to and spaced from one another. The depicted sidewalls 47 are arranged to face one another intermediate first end 58 and second end 60 of the exemplary microstructure device feature 54 . Conductive material 48 is provided directly upon an upper surface 56 and sidewalls 47 of microstructure device feature 54 and directly upon sidewalls 47 and an upper surface 61 of substrate 40 .
Conductive material 48 upon sidewalls 47 of substrate 40 define conductive structures 62 . Conductive material 48 provided upon sidewalls 47 of microstructure device feature 54 provide conductive structures 64 . In the depicted arrangement, conductive structures 62 , 64 form capacitor electrodes of plural capacitors 66 . In the described embodiment, conductive structures 62 , 64 are provided directly upon sidewalls 47 comprising substrate material 41 of respective ones of microstructure device feature 54 and substrate 40 .
In the depicted embodiment of microstructure device 31 , microstructure device feature 54 including conductive structures 64 is a capacitive actuator which may be actuated responsive to the application of biasing voltages to one or more of conductive structures 62 , 64 . In particular, conductive structures 62 , 64 are biased during operations to create electrostatic forces that result in movement of end 60 of microstructure device feature 54 . The microstructure device feature 54 may be referred to as a capacitive micro-electromechanical actuator 68 .
Titanium nitride has been shown to deposit conformally on silicon using chemical vapor deposition even though sidewalls 47 comprising silicon in the described embodiment may exhibit a rough surface profile after trenches 46 are formed within substrate 40 . The resultant conductive structures 62 , 64 upon sidewalls 47 result in a titanium nitride layer having lower surface roughness compared with the prior art processes wherein the roughness or scallops on the surface of the silicon is replicated in subsequent oxide and aluminum layers. Such roughness may degrade the performance of the resultant prior art devices.
Accordingly, in embodiments wherein titanium nitride is utilized, opposing conductive structures 62 , 64 of conductive material 48 have substantially smooth outwardly exposed surfaces. Provision of such surfaces is beneficial to improve controllability of conductive structures 62 , 64 forming the capacitor electrodes and to improve the functionality of the resultant microstructure device 31 in accordance with the described embodiment.
Titanium nitride is additionally more resistant than aluminum to attack if SF 6 plasma silicon release etch chemistry is utilized in processing of assembly 30 depicted in FIG. 20 . Utilization of titanium nitride in accordance with aspects of the invention provides conductive structures 62 , 64 which are more robust than prior art structures.
Inasmuch as conductive structures 62 , 64 upon substrate 40 are conductors, there is no need for aluminum deposition. Direct formation of conductive structures 62 , 64 on substrate 40 in accordance with aspects of the invention reduces process complexity by eliminating oxide deposition and etch steps utilized in the prior art processes. In addition, there is no need to open contact windows through an intermediate insulating layer (e.g., layer 12 a illustrated in FIG. 5 of the prior art process) inasmuch as conductive material 48 is deposited upon the upper surface 61 of substrate 40 . Further, the geometry of the resultant devices 31 of the invention is improved over the prior art devices wherein the formation of additional oxide layers reduces lateral dimensions. In addition, processing according to the present invention eliminates the need for processing following the release step shown in FIG. 20 utilized in the Saif and MacDonald process described above. | Microstructure devices, methods of forming a microstructure device and a method of forming a MEMS device are described. According to one aspect, a microstructure device includes: a semiconductive substrate; a monolithic microstructure device feature coupled with the semiconductive substrate, and wherein at least a portion of the microstructure device feature is configured to move relative to the semiconductive substrate; and a conductive structure provided directly upon the microstructure device feature. | 1 |
PRIORITY INFORMATION
This application claims the benefit of International Patent Application Serial No. PCT/US05/013013 filed on Apr. 19, 2005 and claims priority to U.S. Provisional Patent Application 60/563,515 filed on Apr. 19, 2004, all of which are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
The unauthorized replication of genuine documents, e.g., currency, paid admission tickets, visas, etc., is a widespread problem. Currently, manufacturers of genuine documents incorporate markers, e.g., inks, into the documents that function to identify the documents. Thus, the genuineness of the documents is confirmed by the presence of the inks therein. However, markers exist that are comparable to the markers used by the manufacturers that can be used to produce counterfeit documents of the genuine documents thereby compromising the ability of the marker used by the manufacturers to serve its function as a genuineness indicator.
SUMMARY OF THE INVENTION
It has been unexpectedly discovered that the compounds disclosed in PCT/US02/00797 entitled “Thermochromic Polymers for Rapid Visual Assessment”, filed Jan. 10, 2002, which application is hereby incorporated by reference in its entirety into the present application, reversibly exhibit a fluorescence change that is temperature dependent and that the compounds disclosed in PCT/US03/020537 entitled “Thermochromic Indicator Materials with Controlled Reversibility”, filed Jun. 30, 2003, which application is hereby incorporated by reference in its entirety into the present application, reversibly or irreversibly exhibit a fluorescent change that is temperature dependent. Broadly, the invention is directed to the use of the aforementioned polythiophene compounds in method to determine the genuineness of an article.
In one aspect of the invention, polythiophenes that exhibit a reversible visually detectable color change at a proscribed temperature within the range of between about −40 to 180° C. and unexpectedly exhibit an uncontrolled detectable fluorescence change are used to the determine the genuineness of an article. The visual detection of the color change can include visual observation by an individual or detection of the exhibited color change by a sensor, which sensor would output a signal to be detected in any suitable manner. The detection of the fluorescence change can include the use of an Ocean Optics S2000 instrument having a cylindrical fiber optic reflection probe containing one source fiber and seven collection fibers. The temperature of the color change (hereinafter referred to as the thermochromic transition) can be adjusted by synthetically modifying the thermochromic polymers. It was unexpectedly discovered that the temperature of the fluorescence change (hereinafter referred to as the thermofluorescent transition) coincides with the thermochromic transition of the polythiophenes. The synthesis of polythiophenes is known in the art.
In one aspect, the invention is directed to a method of determining the genuineness of an article which comprises providing an article treated with a composition comprised of a compound having the following structure:
wherein R 1 -R 6 =a hydrogen, substituted or unsubstituted alkyl radical, substituted or unsubstituted alkoxy radical, substituted or unsubstituted aryl radical, substituted or unsubstituted thioalkyl radical, substituted or unsubstituted trialkylsilyl radical, substituted or unsubstituted acyl radical, substituted or unsubstituted ester radical, substituted or unsubstituted amine radical, substituted or unsubstituted amide radical, substituted or unsubstituted heteroaryl or substituted or unsubstituted aryl radical
n is between 1 and 1000, m is between 0 and 1000, 1 is between 1 and 1000; and
a carrier medium, the compound having a low temperature color and having a weak fluorescence and the structure of the compound being designed such that when the composition is placed in a heat-exchange relationship with the article, the low temperature color will change to a high temperature color and the weak fluorescence will change to a strong fluorescence when the a pre-determined temperature is met or exceeded in the article, heating the article to a temperature that meets or exceeds the pre-determined temperature and detecting the color and fluorescence change.
In yet another aspect, the invention is directed to a method of determining the genuineness of an article which comprises providing an article treated with a compound having the following structure:
wherein R 1 -R 6 =a hydrogen, substituted or unsubstituted alkyl radical, substituted or unsubstituted alkoxy radical, substituted or unsubstituted aryl radical, substituted or unsubstituted thioalkyl radical, substituted or unsubstituted trialkylsilyl radical, substituted or unsubstituted acyl radical, substituted or unsubstituted ester radical, substituted or unsubstituted amine radical, substituted or unsubstituted amide radical, substituted or unsubstituted heteroaryl or substituted or unsubstituted aryl radical
n is between 1 and 1000, m is between 0 and 1000, is between 1 and 1000; and
the compound having a low temperature color and having a weak fluorescence and the structure of the compound being designed such that when the composition is placed in a heat-exchange relationship with the article, the low temperature color will change to a high temperature color and the weak fluorescence will change to a strong fluorescence when the pre-determined temperature is met or exceeded in the article, heating the article to a temperature that meets or exceeds the pre-determined temperature and detecting the color and fluorescence change.
As used herein, weak fluorescence of a compound is defined as exhibiting no visually detectable fluorescence upon irradiation with light having a wavelength within the range of between about 250-550 nm, preferably 365 nm, and strong fluorescence of a compound is defined as exhibiting visually detectable fluorescence upon irradiation with light having a wavelength within the range of between about 250-550 nm, preferably 365 nm.
In another aspect, the compound changes from the low temperature color to the high temperature color within plus or minus 5-10° C. below the pre-determined temperature.
In yet another aspect of the invention, polythiophenes that exhibit a controlled, visually detectable color change at a proscribed temperature, e.g., within the range of between about 0° C. to 150° C., preferably 40-135° C. and unexpectedly exhibit a controlled, visually detectable fluorescence change are used to detect the genuineness of an article. The visual detection of the color change can include visual observation by an individual or detection of the exhibited color change by a sensor, which sensor would output a signal to be detected in any suitable manner. The detection of the fluorescence can include irradiation of the polythiophenes with light having a wavelength within the range of between about 250-550 nm, preferably 365 nm, and visual observation by an individual or detection of the fluorescence by a sensor, which sensor would output a signal to be detected in any suitable manner, e.g., an Ocean Optics S2000 instrument having a cylindrical fiber optic reflection probe containing one source fiber and seven collection fibers.
The polythiophenes that exhibit the controlled, visually detectable color change at a proscribed temperature and exhibit a controlled, visually detectable fluorescence change are produced by subjecting the polythiophenes that exhibit a reversible visually detectable color change and unexpectedly exhibit an uncontrolled detectable fluorescence change to the conditions set forth below.
Upon heating the polythiophenes to a high temperature within the range of between about 130° C. and 160° C., preferably 140° C., the polythiophenes will change from a first low temperature color to a high temperature color. The polythiophenes are rapidly cooled to change from the high temperature color to a second low temperature color and will maintain the second low temperature color when maintained at a temperature within the range of between about 0° C. and 30° C., preferably 20° C. In addition to exhibiting the second low temperature color, the polythiophenes unexpectedly exhibited a second low temperature fluorescence. When the polythiophenes are reheated above the thermochromic transition, the polythiophenes will exhibit the high temperature color and unexpectedly exhibit a high temperature fluorescence. The polythiophenes are then allowed to cool slowly below the thermochromic transition whereupon the polythiophenes revert to the first low temperature color and unexpectedly exhibit a first low temperature fluorescence. This controlled reversible thermochromic transition results from the heating of the sample to a high temperature followed by the rapid cooling of the sample. These polythiophenes, when used as pigments to mark an item, can indicate the genuineness of the item by exhibiting expected color and fluorescence changes when exposed to temperatures known only to the manufacturer of the item. Items coated with the polythiophenes show no detectable loss of the changed color or will exhibit no detectable low of the changed fluorescence when after more than one year of storage below the thermochromic transition. The polythiophenes can be dispersed in commercial plastics (polyurethane, polystyrene, polyethylene, etc.) at low concentrations and retain the controlled reversibility. The polythiophenes can also be used as a pigment for inks.
In yet another aspect, the invention is directed to a method of determining the genuineness of an article which comprises providing a composition comprised of a compound having the following structure:
wherein R 1 -R 6 =a hydrogen, substituted or unsubstituted alkyl radical, substituted or unsubstituted alkoxy radical, substituted or unsubstituted aryl radical, substituted or unsubstituted thioalkyl radical, substituted or unsubstituted trialkylsilyl radical, substituted or unsubstituted acyl radical, substituted or unsubstituted ester radical, substituted or unsubstituted amine radical, substituted or unsubstituted amide radical, substituted or unsubstituted aryl radical or substituted or unsubstituted aryl radical,
n is between 1 and 1000, m is between 0 and 1000, and l is between 1 and 1000, and a carrier medium, the compound having a first low temperature color, a first low temperature fluorescence, a second low temperature color, a second low temperature fluorescence, a high temperature color and a high temperature fluorescence, the compound exhibiting a color change from the second low temperature color to the high temperature color and a fluorescence change from the second low temperature fluorescence to the high temperature fluorescence when the compound is exposed to a temperature that meets or exceeds a pre-determined temperature and exhibiting a color change from the high temperature color to a first low temperature color and a fluorescence change from the high temperature fluorescence to a first low temperature fluorescence when the compound is exposed to a decline in temperature from a temperature that meets or exceeds the predetermined temperature to a, temperature of within the range of between about 5 to 20° C. below the pre-determined temperature, the decline in temperature occurring in a time period of greater than 2.0 seconds, treating at least a portion of the article with the composition and detecting the change from the second low temperature color to the high temperature color and the change from the second low temperature fluorescence to the high temperature fluorescence or optionally the change from the high temperature color to the first low temperature color and the change from the high temperature fluorescence to the first low temperature fluorescence.
In another aspect of the invention, a method of determining the genuineness of an article which comprises providing a composition comprised of a compound having the following structure:
wherein R 1 -R 6 =a hydrogen, substituted or unsubstituted alkyl radical, substituted or unsubstituted alkoxy radical, substituted or unsubstituted aryl radical, substituted or unsubstituted thioalkyl radical, substituted or unsubstituted trialkylsilyl radical, substituted or unsubstituted acyl radical, substituted or unsubstituted ester radical, substituted or unsubstituted amine radical, substituted or unsubstituted amide radical, substituted or unsubstituted aryl radical or substituted or unsubstituted aryl radical,
n is between 1 and 1000, m is between 0 and 1000, and 1 is between 1 and 1000; and a carrier medium, the compound having a first low temperature color, a first low temperature fluorescence, a second low temperature color, a second low temperature fluorescence, a high temperature color and a high temperature fluorescence, the compound exhibiting a color change from the second low temperature color to the high temperature color and a fluorescence change from the second low temperature fluorescence to the high temperature fluorescence when the compound is exposed to a temperature that meets or exceeds the pre-determined temperature, exhibiting a color change from the high temperature color to the first low temperature color and a fluorescence change from the high temperature fluorescence to the first low temperature fluorescence when the compound is exposed to a decline in temperature from a temperature that meets or exceeds the predetermined temperature to a temperature within the range of between about 5 to 20° C. below the pre-determined temperature that occurs in a time period greater than 2.0 seconds and exhibiting a color change from the high temperature color to the second low temperature color and a fluorescence change from the high temperature color to the second low temperature fluorescence when the compound is exposed to a decline in temperature from a temperature that meets or exceeds the predetermined temperature to a temperature of within the range of between about 20 to 50° C. below the predetermined temperature that occurs in a time period of less than 2.0 seconds, treating at least a portion of the article with the compound and detecting the change from the second low temperature color to the high temperature color and the change from the second low fluorescence to the high temperature fluorescence or optionally the change from the high temperature color to the first low temperature color and the change from the high temperature fluorescence to the low temperature fluorescence or optionally the change from the high temperature color to the second low temperature color and the change from the high temperature fluorescence to the second low temperature fluorescence.
Suitable articles can include thermopolymers, thermosetting polymers, paper, paper laminated with plastic, textiles, coated textiles, and natural and unnatural fibers. The carrier medium or composition can be generally applied to the article as a coating on an area of the article, or the entire article, which will be visible during the expected use of the article. The coating can be applied by any technique known in the art, such as by brush, roller, spraying, etc. Accordingly, the coatings typically have a thickness of 0.1 to 1000 microns. The carrier medium or composition can also be absorbed on a surface or both absorbed and adsorbed on a surface.
The carrier medium is selected from the group consisting of polyurethanes, elastomers including polysiloxanes and polydienes; polyacrylates, poly(ethylene terephthalate)s (PET), polysytrenes, polyolefins including polyethylenes (HDPE and LDPE) and polypropylene, polycarbonates, polyacrylics, polyacrylic acids, polyacrylamides, polymethacrylics, polyvinyl ethers, polyvinyl halides, poly(vinyl nitrile)s polyvinyl esters, polyesters, polysofones, polysulfonamides, polyamides, polyimines, polyimides, and carbohydrates.
As used herein, the terms low temperature color means the color the polythiophenes will exhibit below the pre-determined temperature and when the color change has either been completed or commenced. The term high temperature color means the color the polythiophenes will exhibit above the pre-determined temperature and when the color change has been either completed or commenced.
These and other objects, features and advantages of the present invention will become more apparent in light of the following detailed description of preferred embodiments thereof, as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph showing the wavelength dependence of a thermally marked film under UV radiation which illustrates the temperature dependence fluorescence of a polythiophene film;
FIG. 2 depicts a film having an area marked with a polythiophene film in the shape of a key;
FIG. 3A depicts a film having an area marked with the letters “URI” without irradiation by UV irradiation;
FIG. 3B depicts the film of 3 A exhibiting a medium intensity low temperature fluorescence;
FIG. 4 is a plot showing the fluorescence intensity at 621 nm as a function of temperature demonstration the change in intensity;
FIG. 5A depicts a polythiophene containing ink printed onto paper at room temperature under room light;
FIG. 5B depicts a polythiopene ink printed on paper heated above the thermochromic transition;
FIG. 5C depicts a polythiophene containing ink printed onto paper at room temperature under UV irradiation; and.
FIG. 5D depicts a polythiophene containing ink printed onto paper heated above the thermochromic transition temperature under UV irradiation.
DETAILED DESCRIPTION OF THE INVENTION
The polythiophenes exhibiting controlled thermochromic and thermofluorescent transitions can be prepared via a two step process. Thin films or powders of polythiophenes can be heated above the thermochromic transition, typically 120-150° C., with a heat gun, oven, or hot plate. The samples are typically heated over a short period of time (5-20 seconds), but slower heating rates are appropriate also, e.g., greater than at least 20 seconds, preferably 20 to 1000 seconds. The heated films or powders are then rapidly removed from the heat, e.g., within a time period of about 0 to 10 seconds, preferably less than 2 seconds and cooled via contact with a thermally conductive material such as a metal plate. The metal plate can be at room temperature or below room temperature as long as it is at least 20° C. below the thermochromic transition temperature. The contact with the low temperature thermally conductive surface rapidly cools the polythiophenes from at or above the thermochromic transition to within 5 to 20° below the thermochromic transition within a time period less than 2 seconds, preferably 0.1 seconds, resulting in the production of the second low temperature colored material.
Polythiophenes exhibit a reversible visually detectable color change at a proscribed temperature within the range of between about −40 to 180° C. and exhibit a detectable fluorescence change are used to the determine the genuineness of an article. The visual detection of the color change can include visual observation by an individual or detection of the exhibited color change by a sensor. The temperature of the thermochromic transition can be adjusted by synthetically modifying the thermochromic polymers. It was unexpectedly discovered that the temperature of the thermofluorescent transition coincides with the thermochromic transition of the polythiophenes.
Referring to FIG. 1 , the wavelength dependence of a thermally marked film under UV radiation which illustrates the temperature dependence fluorescence of a film comprised of a compound I wherein R 1 and R 4 are C 22 H 45 , R 2 , R 3 , R 5 and R 6 are H, n is 0.8, m is 0.2, and 1 is 40.
Referring to FIG. 2 , a film is depicted having an area marked with a polythiophene film in the shape of a key. The films are comprised of compound I wherein R 1 and R 4 are C 22 H 45 , R 2 , R 3 , R 5 and R 6 are H, n is 0.8, m is 0.2, and l is 40.
The synthesis of the polythiophenes included oxidative polymerization of 3-docosylthiophene with FeCl 3 in either chloroform of methylene chloride. Thereafter the polythiophenes were coated onto a substrate by spin casting form a THF solution to form a film. At room temperature, the film, exhibiting a burgundy color was irradiated with light having a wavelength in the range of between about 250 and 550 nm by directing a the light from a UV lamp (Fisher Scientific) onto the film. The irradiated film did not exhibit a visually detectable fluorescence. To detect and measure the fluorescence, an Ocean Optics S2000 instrument using a cylindrical fiber optic reflection probe containing one source fiber and seven collection fibers the sample was used. Subsequently, the film was heated to a temperature of about 130° C. by a heat gun. The heated film exhibited a color change from burgundy to yellow and exhibited a light having a wavelength of about 525 to 650 nm when irradiated with light having a wavelength in the range of between about 250 and 550 nm by directing a light from the UV lamp. As the film in the area marked in the key cooled from 130° C. to about room temperature within a period of about 0.1 seconds (time), the color changed from yellow to light red and exhibited light having a wavelength of about 575 and 750 nm when irradiated with light having a wavelength of in the range of between about 250 and 550 nm by again directing a light from the UV lamp onto the film. The area of the film outside the key, never having been rapidly cooled, was allowed to cool from 130° C. to about room temperature, exhibited no visually detectable fluorescence upon irradiation with light having a wavelength within the range of between about 250 and 550 nm by directing the light from the UV lamp and exhibited a color change from yellow to burgundy. In addition, if the area of film in the shape of the key is again heated to a temperature between 120 and 150° C. and then allowed to cool to room temperature in greater than 2.0 seconds, the key can exhibit a color change from yellow to burgundy and can exhibit a light having a wavelength within the range of between about 625 and 750 nm when irradiated with light within the range of between about 250 and 550 nm by directing the light from the UV lamp.
Referring to FIG. 3A , a film is depicted having an area marked with the letters “URI” that under natural room light, no fluorescence is observed. Referring to FIG. 3B , the film in FIG. 3A is shown exhibiting a medium intensity low temperature fluorescence upon irradiation by a UV lamp at 365 nm. The film is comprised of compound I wherein R 1 and R 4 are C 22 H 45 , R 2 , R 3 , R 5 and R 6 are H, n is>0.95, m is<0.05, and l is 40. These films were prepared via Grignard metathesis polymerization as reported by McCullough, R. D. and S. D. Williams, Journal of American Chemical Society, 1993, Vol. 115, pg. 11608.
The films in FIGS. 3A and 3B were spin coated from THF solutions of the polythiophene onto paper. After spin coating, the films were heated with a heat gun to between 120 and 150° C. and then were allowed to slowly cool (>2 seconds) to room temperature to remove any residual solvent. The low temperature films are purple (color) and have undetectable fluorescence emission. After heating films to between 120 and 150° C. the films can be rapidly cooled (0.1 second) by pressing a metal fuse onto the surface of the film. Rapid cooling to low temperature, 0 to 30° C., allows the generation of an red (color) mark in the form of URI, which URI will emit light having a wavelength of about 500 to 600 nm when excited with a UV lamp (345 nm) and detected either by the eye or an Ocean Optics S2000 instrument using a cylindrical fiber optic reflection probe containing one source fiber and seven collection fibers. The remainder of the film, which cooled slowly, returns to the original low temperature color, purple and the fluorescence emission is not detectable by the above mention methods. If the film is maintained at temperatures below the thermochromic transition of the polythiophene film (80° C.) the URI mark will be retained for more than a year and the mark will fluoresce at wavelength of about 500 to 600 nm when tested.
Referring to FIG. 4 , the fluorescence intensity at 621 nm of a thermally marked film under UV radiation which illustrates the temperature dependence fluorescence of a film comprised of a compound I wherein R 1 and R 4 are C 22 H 45 , R 2 , R 3 , R 5 and R 6 are H, n is 0.8, m is 0.2, and L is 40.
Referring to FIGS. 5A , 5 B, 5 C, and 5 D an ink formulation composed of 5% compound I wherein R 1 and R 4 are C 18 H 37 , R 2 , R 3 , R 5 , and R 6 are H, n is 0.80, M is 0.20, and L is 30. The synthesis of the polythiophenes included oxidative polymerization of 3-octadecylthiophene with FeCl 3 in either chloroform of methylene chloride. Thereafter the polythiophene was dispersed in block printing ink extender via grinding with a mortar and pestle and printed onto paper with a rubber stamp. The foregoing description has been limited to a few embodiments of the invention. It will be apparent, however, that variations and modifications can be made to the invention, with the attainment of some or all of the advantages. Therefore, it is the object of the claims to cover all such variations and modifications as come within the true spirit and scope of the invention. | The invention is directed to use of polythiophenes in a method to determine the genuineness of an article which method comprises providing an article treated with a composition comprised of a polythiophene, the polythiophene having a low temperature color and a weak fluorescence and the structure of the polythiophene being designed such that when the composition is placed in a heat-exchange relationship with the article, the low temperature color will change to a high temperature color and the weak fluorescence will change to a strong fluorescence when a pre-determined temperature is met or exceeded in the article, heating the article to a temperature that meets or exceeds the pre-determined temperature and detecting the color and the fluorescence change. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates to an extended release dosage form of highly water-soluble antidiabetic drug metformin or its pharmaceutically acceptable salts. This invention also relates to methods for preparing the extended release dosage form of metformin or its pharmaceutically acceptable salts.
BACKGROUND OF THE INVENTION
[0002] Metformin hydrochloride is a biguanide derivative used as an oral antidiabetic. Metformin tablets are marketed under the trade name Glucophage and Glucophage XR (extended release).
[0003] Metformin hydrochloride has intrinsically poor permeability in the lower portion of the gastrointestinal tract leading to absorption almost exclusively in the upper part of the gastrointestinal tract. Its oral bioavailability is in the range of 40 to 60% decreasing with increasing dosage, which suggests some kind of saturable absorption process, or permeability/transit time limited absorption. It also has a very high water solubility (>300 mg/ml at 25° C.), which leads to difficulty in providing a slow release rate from a formulation and problems in controlling the initial burst of drug from such a formulation. These two difficulties are further compounded by the high unit dose required for metformin hydrochloride.
[0004] Typical prior art techniques for creating a controlled release oral dosage form would involve either matrix systems or multi particulate systems. Matrix systems may be formulated by homogeneously mixing drug with hydrophilic polymers, such as hydroxypropylmethylcellulose, hydroxypropylcellulose, polyethylene oxide, carbomer, certain methacrylic acid derived polymers, sodium alginate, or mixtures thereof and compressing the resultant mixture into tablets. Hydrophobic polymers, such as ethyl cellulose, certain polymeric methacrylic acid esters, cellulose acetate butyrate, poly(ethylene-co-vinyl-acetate) may be uniformly incorporated with the above materials to give additional control of release. A further alternative involves embedding drug within a wax-based tablet, by granulation or simply mixing of drug with a wax, such as carnauba wax, microcrystalline wax or commercially available purified fatty acid esters.
[0005] Most extended-release forms are designed so that the administration of a single dosage unit provides the immediate release of an amount of drug that promptly produces the desired therapeutic effect and also a gradual and continual release of additional amounts of drug to maintain this level of effect over an extended period of time to overcome frequent or multiple dosing. In this type of dosage form, the design is based on the particular qualities of each individual drug. In the case of Metformin HCl which is a very highly soluble drug, it is imperative to control the release in order to obtain a controlled release formulation.
[0006] Other advantages of extended-release products are reduced side effects and increased patient compliance. These advantages relate to the fact that extended-release preparations are designed to maintain the blood concentration of the drug at a desired level over a prolonged period of time thereby reducing the frequency of dosing and thus ensuring patient compliance.
[0007] The following patents/publications describes extended/and controlled release compositions of metformin:
[0008] U.S. Pat. No. 5,955,106 discloses a composition comprising metformin as the active substance and a hydrocolloid forming retarding agent, wherein the pharmaceutical composition has a residual moisture content of about 0.5-3% by weight.
[0009] U.S. Pat. No. 6,340,475 discloses a controlled release gastric retentive oral dosage form comprising a solid polymeric matrix with metformin dispersed therein at a weight ratio of drug to polymer of from about 15:85 to about 80:20. This patent further discloses the polymeric matrix is formed of a polymer selected from the group consisting of poly(ethylene oxide), cellulose, alkyl-substituted celluloses, crosslinked polyacrylic acids, and xanthan gum.
[0010] U.S. Pat. No. 6,033,685 discloses a tablet for the controlled release of an active agent comprising (a) a matrix layer comprising an active agent embedded in a non-swelling, non-erodible hydrophobic matrix; (b) a first barrier layer applied to a single face of the matrix layer; and (c) an optional second barrier layer laminated to the opposite face of the matrix layer; wherein the matrix layer comprises up to about 80% active agent and from about 5% to about 80% by weight of nonswellable waxes or polymeric material insoluble in aqueous medium, and the first and second barrier layers independently comprise (1) polymeric material exhibiting a high degree of swelling and gelling in aqueous medium or (2) nonswellable wax or polymeric material insoluble in aqueous medium.
[0011] U.S. Pat. Nos. 6,475,521 and 6,660,300 discloses a pharmaceutical formulation comprising (1) an inner solid particulate phase, and (2) an outer solid continuous phase in which particles of the inner solid particulate phase are dispersed and embedded, the particles of the inner solid particulate phase comprising (a) a pharmaceutical having a high water solubility selected from metformin or a pharmaceutically acceptable salt thereof; and (b) an extended release material, and the outer solid continuous phase comprising an extended release material, wherein the total extended release material content in both the inner solid particulate phase and the outer solid continuous phase is within the range from about 25 to about 75% by weight of the pharmaceutical formulation.
[0012] U.S. Pat. No. 6,524,618 describes an extended release matrix formulation capable of being directly compressed into tablets comprising (a) about 30 to about 60% of metformin hydrochloride having a particle size of about 150 to about 600 microns, (b) one or more pharmaceutically acceptable polymers selected from the group consisting of polyethylene oxide, hydroxypropyl cellulose, hydroxyethyl cellulose and ethyl cellulose (c) about 5 to about 40% of a pharmaceutically acceptable insoluble filler; (d) about 0.1 to about 3% by weight a glidant; and (e) about 0.1 to about 3% by weight an acceptable lubricant.
[0013] US 2003/0187074 describes an oral delivery system for the treatment of non-insulin dependent diabetes mellitus in humans for the controlled release of a biguanide or pharmaceutically acceptable salt thereof, comprising: a pharmaceutically effective amount of a biguanide or pharmaceutically acceptable salt of the biguanide; and a water-insoluble polymeric carrier comprising a water-insoluble polymer; wherein the delivery system provides a pH-independent, controlled release of the biguanide or pharmaceutically acceptable salt thereof over an extended period of time.
[0014] U.S. patent Publication 2004/0109891 discloses a sustained-release pharmaceutical composition comprising metformin or a pharmaceutically acceptable salt thereof in an amount of about 100 mg to about 1000 mg; and a sustained-release delivery system comprising xanthan gum in an amount of about 5% to about 60% by weight; locust bean gum in an amount of about 10% to about 70% by weight.
[0015] US 2004/0161461 and US 2003/0170302 describes an extended release pharmaceutical tablet comprising: (i) a core comprising by weight, based on the core weight, about, 70% to about 99% metformin and pharmaceutically acceptable excipients; and (ii) a coating surrounding said core, wherein said coating is permeable to metformin, said extended release tablet exhibiting a dissolution profile such that after about 2 hours, from about 7% to about 60% of the metformin is released; after about 4 hours, from about 15% to about 90% of the metformin is released; after about 8 hours, from about 50% to about 100% of the metformin is released; after about 12 hours, more than about 75% of the metformin is released.
[0016] WO 03/011255 discloses a gastric retention controlled-drug delivery system comprising (a) a controlled release core comprising a drug, a highly swellable polymer and a gas generating compound, said core being capable of swelling and achieving floatation rapidly while maintaining its physical integrity in gastrointestinal fluids for prolonged periods, and (b) a rapidly releasing coat composition comprising the same drug as in the core and pharmaceutically acceptable excipients, wherein the coating composition surrounds the core such that the system provides a biphasic release of the drug in gastrointestinal fluids. This publication discloses a biphasic extended release dosage form comprising core and coating the core and provides for immediate release and extended release of the drug, which makes the process costlier and complex.
[0017] WO 2005/060942 discloses an extended release monophasic dosage form of metformin comprising a matrix of polymer and carbonate.
[0018] WO 2005/123134 discloses controlled release composition of metformin comprising hydrophilic polymers and hydrophobic lubricating agents.
[0019] The above prior art describes various controlled/extended release compositions of metformin. However, still there is need for developing extended release dosage forms of metformin, which will have release profile comparable to that of marketed dosage forms.
[0020] While continuing our efforts to develop extended release formulations of metformin, the inventors of the present invention found that monophasic dosage forms comprising polymer and inorganic silicates resulted in dosage form with dissolution profiles similar to the marketed metformin extended release (Glucophage XR) tablets.
OBJECTIVE OF THE INVENTION
[0021] The object of the present invention is to prepare monophasic extended release pharmaceutical dosage forms of poorly compressible drug, metformin which will have adequate hardness and good reproducibility that releases the drug in a controlled manner over an extended period of time.
[0022] Another objective of the present invention is to provide monophasic extended release dosage form, which is uncoated, simple and economic.
[0023] Yet another objective of the present invention is to provide extended release solid dosage forms of metformin hydrochloride in such a way that it will comply with the reference product in terms of in vitro parameters like dissolution, disintegration etc and in vivo parameters like bioequivalence.
SUMMARY OF THE INVENTION
[0024] Accordingly, the present invention provides an extended release monophasic dosage form of metformin or its pharmaceutically acceptable salts comprising hydrophilic polymer, an inorganic silicate and one or more pharmaceutically acceptable excipients.
DETAILED DESCRIPTION OF THE INVENTION
[0025] Inorganic silicates are water-swellable clays that have been used for many years in the formulation of tablets, ointments and creams. These are used in oral and topical formulations as suspending and stabilizing agents either alone or in combination with other suspending agents. The advantage of these water-swellable clays is that they produce synergistic rheological effects when mixed with other suspending agents or organic thickeners like xanthan gum, sodium carrageenan, sodium alginate, gum tragacanth, gum arabic, hydroxypropyl guar, sodium carboxymethylcellulose, methyl cellulose etc. The mixtures produce greater viscosity and yield value (therefore greater thickening, and suspending properties and there by improving stability) than those developed by the individual components of the mixture. A water-swellable clay that is particularly effective in combination with xanthan gum is magnesium aluminum silicate and magnesium silicate.
[0026] The present invention is based on synergism between organic thickeners with inorganic silicates like magnesium silicate, magnesium tri silicate or magnesium aluminum silicate. The increased viscosity of polymers when combined with silicates provides extended release of metformin from the tablet formulation.
[0027] The extended release dosage forms of the present invention are monophasic, which releases the drug for prolonged period of time.
[0028] The extended release dosage forms of the present invention comprises drug to polymer plus inorganic silicate in the ratio of 5:0.5 to 1:5.
[0029] The extended release dosage forms of the present invention comprises drug and inorganic silicate in the ratio of 1:0.05 to 1:1.
[0030] The extended release dosage forms of the present invention comprises drug to polymer in the ratio of 1:0.05 to 1:0.6.
[0031] The term pharmaceutically acceptable excipients as used in this invention comprise binders, fillers, lubricants, glidants and the like.
[0032] The pharmaceutically acceptable salts of metformin as used here include hydrochloride, hydrobromide and the like.
[0033] The inorganic silicates of the present invention are selected from magnesium aluminum silicate, magnesium silicate, magnesium trisilicate, bentonite, calcium silicate, aluminium silicate and the like.
[0034] Suitable binders according to the present invention are selected from methylcellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose, povidone, copovidone, gelatin, gum arabic, ethyl cellulose, polyvinyl alcohol, starch, pregelatinized starch, agar, tragacanth or sodium alginate.
[0035] Suitable fillers used according to the present invention are selected from calcium phosphate-dibasic, cellulose-microcrystalline, cellulose powdered, calcium silicate, polyols such as mannitol, sorbitol, xylitol, maltitol, sucrose and combinations thereof.
[0036] Suitable lubricants according to the present invention are selected from talc, magnesium stearate, stearic acid, zinc stearate, sodium lauryl sulfate, sodium stearyl fumarate, hydrogenated vegetable oil, glyceryl behenate and suitable glidants include colloidal silicon dioxide or talc.
[0037] Suitable hydrophilic polymers according to present invention are selected from polyvinylpyrrolidone, alginate or its salts; xanthan gum, cellulose polymer such as hydroxypropylmethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose phthalate, methylcellulose, carboxymethyl cellulose sodium, hydroxyethyl cellulose and the like; polyethylene oxide, carbopol, pectin, galactomannan, or polyethylene glycol (PEG).
[0038] The pharmaceutically acceptable salts of metformin as used here include hydrochloride, hydrobromide and the like.
[0039] The present invention provides a simple, non-complex and more economic process for the preparation of an extended release matrix based dosage form, which comprises the steps of:
i) sifting metformin hydrochloride, polymer, and optionally inorganic silicates and fillers, ii) mixing the sifted materials of step (i) in a rapid mixer granulator, iii) granulating the blend of step (ii) with a solution of binder, iv) drying the wet mass of step (iii) in a fluid bed drier, v) milling the dried granules, vi) optionally mixing the dried granules with inorganic silicates, polymers and fillers, vii) lubricating the blend of step (vi) with lubricants and
compressing the lubricated blend of step (vii) to get extended release tablets of metformin.
[0047] The solvent used for preparing binder solution according to the present invention are selected from water, isopropyl alcohol, ethanol, acetone, methylene chloride and the like or mixture thereof.
[0048] The following examples further exemplify the inventions and are not intended to limit the scope of the invention. It is obvious to those skilled in the art to find out the composition for other dosage forms and substitute the equivalent excipients as described in this specification or with the one known to the industry.
EXAMPLE 1
[0049]
[0000]
Ingredients
Quantity
Metformin HCl
750 mg
Magnesium Aluminum Silicate
240 mg
Xanthan gum
60 mg
Carbopol 971 P
96 mg
Hydroxypropyl cellulose
14 mg
Magnesium stearate
10 mg
IPA
q.s.
Tablet Weight
1170 mg
EXAMPLE 2
[0050]
[0000]
Ingredients
Quantity
Metformin HCl
750 mg
Magnesium Aluminum Silicate
150 mg
Xanthan gum
60 mg
Carbopol 971 P
96 mg
Hydroxypropyl cellulose
14 mg
Magnesium stearate
10 mg
IPA
q.s.
Tablet Weight
1080 mg
[0051] The processing steps that are involved in examples 1 and 2 are
i) sifted metformin HCl, magnesium aluminum silicate, xanthan gum, and carbopol 971 P through #40 mesh, ii) loaded the material of step (i) in RMG and mixed for 15 minutes, iii) dissolved hydroxypropyl cellulose in sufficient quantity of IPA:water iv) added the binder solution of step (iii) to dry mix of step (ii) and continued mixing until granules of uniform consistency were obtained, v) granules were dried, milled and lubricated, vi) granules of step (v) were compressed to form extended release tablets of metformin.
EXAMPLE 3
[0058]
[0000]
Ingredients
Quantity
Metformin HCl
750 mg
Magnesium Aluminum Silicate
240 mg
Xanthan gum
60 mg
Carbapol 971 P
96 mg
PVP K90
14 mg
Magnesium stearate
10 mg
IPA
q.s.
Tablet Weight
1170 mg
EXAMPLE 4
[0059]
[0000]
Ingredients
Quantity
Metformin HCl
750 mg
Magnesium Aluminum Silicate
150 mg
Xanthan gum
60 mg
Carbopol 971 P
96 mg
PVP K90
14 mg
Magnesium stearate
10 mg
IPA
q.s.
Tablet Weight
1080 mg
[0060] The processing steps that are involved in example 3 and 4 are:
i) sifted metformin HCl, magnesium aluminum silicate, xanthan gum, and carbopol 971 P through #40 mesh, ii) loaded the material of step (i) in RMG and mixed for 15 minutes, iii) dissolved polyvinyl pyrrolidone in sufficient quantity of IPA:water iv) added the binder solution of step (iii) to dry mix of step (ii) and continued mixing until granules of uniform consistency were obtained, v) unloaded the granules formed and dried, vi) lubricated the granules of step (v) vii) compressed the lubricated blend of step (vi) to form extended release tablets of metformin.
EXAMPLE 5
[0068]
[0000]
Ingredients
Quantity
Metformin HCl
750 mg
Magnesium Aluminum Silicate
240 mg
Xanthan gum
46 mg
Carbopol 971 P
96 mg
Hydroxypropyl cellulose
8 mg
Carbopol 71 G
20 mg
Magnesium stearate
10 mg
IPA
q.s.
Tablet Weight
1170 mg
[0069] The processing steps that are involved in example 5 are:
i) sifted metformin HCl, magnesium aluminum silicate, xanthan gum, and carbopol 971P through #40 mesh, ii) loaded the sifted metformin HCl and Carbopol 971P of step (i) in RMG and mixed for 15 minutes, iii) dissolved hydroxypropyl cellulose in sufficient quantity of IPA:water iv) added the binder solution of step (iii) to dry mix of step (ii) and continued mixing until granules of uniform consistency were obtained, v) unloaded the granules formed and dried, vi) sifted the granules of step (v) through # 20 sieve, vii) added the sifted magnesium aluminium silicate, xanthan gum of step (i) and carbopol 71 G to the sifted granules of step (vi), viii) compressed the lubricated blend of step (vi) to form extended release tablets of metformin.
EXAMPLE 6
[0078]
[0000]
Quantity
Ingredient
Metformin HCl
750
mg
Carbopol 971P
96
mg
Hdroxypropyl cellulose
8
mg
IPA
q.s
Extragranular
Carbopol 71 G
20
mg
Xanthan gum
46
mg
Magnesium Trisilicate
297.7
mg
Magnesium Stearate
12.30
mg
Total
1230
mg
[0079] The processing steps that are involved in example 6 are:
i) sifted metformin HCl, and carbopol 971P through mesh # 40 and mixed for 10 minutes, ii) dissolved hydroxypropyl cellulose in isopropyl alcohol, iii) granulated the contents of step (i) with binder solution of step (ii), iv) dried the granules of step (iii), v) sifted magnesium trisilicate, carbopol 71G, and xanthan gum through mesh # 30 and mixed with the dried granules of step (iv), vi) lubricated the contents of step (v) and vii) compressed the blend of step (vi) into tablets.
EXAMPLE 7
[0087]
[0000]
Quantity
Ingredient
Metformin HCl
750
mg
Carbopol 971P
116
mg
Hdroxypropyl cellulose
8
mg
IPA
q.s
Extragranular
Xanthan gum
46
mg
Magnesium Trisilicate
297.7
mg
Magnesium Stearate
12.30
mg
Total
1230
mg
[0088] The processing steps that are involved in example 7 are:
i) sifted metformin HCl, and carbopol 971P through mesh # 40 and mixed for 10 minutes, ii) dissolved hydroxypropyl cellulose in isopropyl alcohol, iii) granulated the contents of step (i) with binder solution of step (ii), iv) dried the granules of step (iii), v) sifted magnesium trsilicate, and xanthan gum through mesh # 30 and mixed with the dried granules of step (iv), vi) lubricated the contents of step (v) and vii) compressed the blend of step (vi) into tablets.
EXAMPLE 8
[0096]
[0000]
Quantity
Ingredient
Metformin HCl
750
mg
Magnesium Trisilicate
140.85
mg
Carbopol 971P
116
mg
Hdroxypropyl cellulose
16
mg
IPA
q.s
Extragranular
Xanthan gum
46
mg
Magnesium Trisilicate
148.85
mg
Magnesium Stearate
12.30
mg
Total
1230
mg
[0097] The processing steps that are involved in example 8 are:
i) sifted metformin HCl, magnesium trisilicate, and carbopol 971P through mesh # 40 and mixed for 10 minutes, ii) dissolved hydroxypropyl cellulose in isopropyl alcohol, iii) granulated the contents of step (i) with binder solution of step (ii), iv) dried the granules of step (iii), v) sifted magnesium trsilicate, and xanthan gum through mesh # 30 and passed through roler compacter and collected the flakes, vi) flakes of step (v) were passed mesh # 18 and mixed with the dried granules of step (iv), vii) lubricated the blend of step (vi) and compressed into tablets.
Comparative Dissolution Profile of Metformin HCl Extended Release Tablets with Glucophage XR (BMS)
[0105] Table 1 given below shows the dissolution profile of extended release tablets of metformin carried out in pH 6.8 Phosphate buffer as medium using—USP-I (Basket) Apparatus, @100 rpm speed. The results were represented graphically in FIG. 1
[0000]
TABLE 1
% Drug released
Time in
Glucophage XR
hours
Example 1
Example 2
Example 5
(750 mg)
1
30
37
32
32
2
45
51
44
46
3
55
61
55
59
4
63
70
65
65
6
74
80
78
78
8
82
86
84
87
10
87
92
88
94
12
92
93
91
96
Bio Equivalence Study
[0106] To compare the rate and extent of absorption of Metformin HCl 750 mg (TEST) extended release dosage form of the present invention with Glucophage XR 750 mg (REFERENCE) of Bristol-myers Squibb, USA (Reference), a randomized, cross-over, single-dose oral comparative bioavailability study was conducted in 12 healthy, adult, male, human subjects under fed conditions. The results of this study are as given in Table 2:
[0000]
TABLE 2
Ratio
Dependant
[% Ref]
CI_90_Lower
CI_90_Upper
Power
Ln(AUCINF_obs)
93.71
85.28
102.97
0.99
Ln (AUClast)
94.02
83.66
105.66
0.93
Ln (Cmax)
107.66
96.62
119.97
0.96
[0107] The study results indicate that the pharmacokinetic parameters for Test and Reference are falling with in the 80-125% FDA acceptance range. Based on these results, the Metformin HCl extended release dosage form of the present invention and Glucophage XR tablets are meeting bioequivalent criteria under fed conditions. | The present invention relates to an extended release dosage form of highly water-soluble antidiabetic drug metformin or its pharmaceutically acceptable salts. This invention also relates to methods for preparing the extended release dosage forms of metformin or its pharmaceutically acceptable salts. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application for Patent No. 61/190,129, filed Aug. 26, 2008, and 61/146,053, filed Jan. 21, 2009, the entire contents of both of which are specifically incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] Post-translational modification (PTM) of proteins (e.g., enzymes) plays many import roles in cellular physiology. PTM is typically accomplished by enzymes that recognize and modify the structure of a protein substrate to yield a modified protein product. Some enzymes that belong to the class of post-translational modifying proteins include, for example, protein kinases, phosphatases, proteases, methylases, acetylases, phosphodiesterases, and lipases. Protein kinases are enzymes that use adenosine triphosphate (ATP) as a phosphate donor and transfer a phosphate group to a specific protein substrate. Protein phosphatases catalyze the reverse process, namely the removal of a phosphate from a substrate. Methylases and acetylases transfer methyl or acetyl groups to substrates, respectively. Proteases, phosphodiesterases and lipases cleave their respective substrates.
[0003] PTM of proteins is the main regulator of cellular signaling and can confer or abolish activity to an enzyme or otherwise alter the structure of a protein so that it gains the ability to bind to another protein or to disassociate from it. Aberrant regulation of PTM is implicated in various diseases such as cancer, diabetes, hypertension, and inflammatory diseases. Increasing efforts are being placed on the discovery of drugs that can be used to modulate the activity of enzymes that are inappropriately activated and alter the structure of proteins following expression. This has created the demand for techniques that can easily measure the activity of enzymes.
[0004] Distinct cellular phenotypes are the result of differential activation of cellular signaling pathways. More than 500 kinases are involved in regulating signal transduction by activating or de-activating their molecular targets by virtue of phosphorylation. In addition to the enzymes discussed above, phosphodiesterases, enzymes that hydrolyze cyclic nucleotides, are involved in the regulation of signaling pathways. Aberrant protein activity within a pathway is often the result of genetic variations and is implicated in various diseases such as cancer and diabetes. In addition, signaling pathways can be manipulated by viruses and other infectious agents in a manner that is conducive to the infectious agent's survival and propagation. Targeting the effector response of disease as opposed to the source has led to the successful treatment of infection using drugs known to inhibit the activity of an aberrantly regulated kinase (see, for example, Wei et al., Antimicrob Agents Chemother. 2007 December; 51(12): 4321 1328, Ruhland et al. Exp. Parasitol. 2009 May; 122 (1); 28-36, and Stantchev et al., Virus Res 2007 February; 123(2); 178-189.) Thus, cellular signaling pathway profiling is an approach that can further the understanding of the mechanisms and treatment of disease and can have a high potential impact in areas of genetics, infection and immunology.
[0005] Assays for detecting the activity of kinase enzymes are known. Radioactive assays have historically been used for this purpose (see for example U.S. Pat. Nos. 5,538,858; 4,568,649; 5,665,562 and 5,989,854). However, because of the cost and health concerns associated with handling of radioactive materials, fluorescence-based methods were developed to replace radioactive methods. In order to be compatible with the robotic screening of thousands to millions of chemical compounds in a process called “high throughput screening” (HTS), homogeneous assays are most desirable. Some non-radioactive, homogeneous assays are based on fluorescence resonance energy transfer (FRET) and fluorescence polarization (FP) (see, for example U.S. Pat. Nos, 6,287,774 and 7,306,928). In FRET methods, a light-absorbing dye, capable of light emission (donor fluorophore), is combined with another fluorophore (acceptor fluorophore) that has spectral overlap with the first fluorophore. When the two dyes are brought into close proximity to each other, excitation of the donor fluorophore results in energy being transferred to the second, acceptor fluorophore and consequently, the emission from the first, donor fluorophore is decreased. If the acceptor fluorophore is capable of emitting light, the light absorbed form the donor fluorophore can be re-emitted by the acceptor fluorophore in a process called sensitized emission. Fluorescence quench of a donor fluorophore can also be achieved by the process of electron or charge transfer in which an electron is transferred to the acceptor. This process does not require spectral overlap between the acceptor and the donor fluorophore and thus any acceptor fluorophore that is within the UV-visible range can be used for energy transfer based assays.
[0006] In FP, the readout relies on a measurable change in fluorescence polarization of a fluorophore-labeled substrate, which is achieved by its binding to a molecule of greater size. The increase in size decreases the speed of molecular rotation of the substrate and increases the amount of polarized light emitted from the fluorophore-labeled substrate. The amount of polarized light is calculated as the ratio of two separate emission events monitored on the parallel and perpendicular plane.
[0007] Assays can be constructed using FRET techniques where specific binding events can be utilized to bring two fluorophores into close proximity. For example, assays that are based on the affinity of paramagnetic metal ions to phosphates present on substrates labeled with a fluorophore have been described. In these assays, metal ions are coupled to metal ion coordinating groups. In one invention, (U.S. Pat. No. 7,306,928) the sensor consists of a complexed paramagnetic ion, which, upon association to a fluorophore-labeled substrate, extinguishes the fluorescence of the substrate. In another invention (U.S. Pat. No. 6,699,655) the metal ion is complexed to the surface of a microsphere. Upon binding to a phosphorylated and fluorophore-labeled substrate the change in FP of the substrate is monitored. A similar microsphere-based approach is disclosed in US published patent application 2007/0238143 in which the microsphere is co-coated with a conjugated fluorescent polymer, which undergoes superquenching upon association to a fluorophore-labeled and phosphorylated substrate.
[0008] Drawbacks of the FRET technique include the requirement of two fluorophores with spectral overlap, and negative assay interactions, such as non-specific interaction of the sensor with the dye-labeled substrate. Additionally, assays are generally of a “turn off” type, unless sensitized emission is recorded. Assays based on FP are popular due to the fact that they generate a “turn on” signal. However, drawbacks of FP include the requirement for expensive equipment capable of monitoring FP, non-specific signals associated with incorporation of small molecular weight fluorophores into large detergent micelles and limitations of the size of substrate that can be detected.
[0009] Metal ions described for use in kinase/phosphatase, protease and phosphodiesterase assays are the paramagnetic metal iron (U.S. Pat. No. 7,306,928) that quenches fluorescence of a dye-labeled substrate in FRET assays or change the molecular rotation of a fluorophore-labeled substrate in FP assays (U.S. Pat. No. 6,699,65). Additionally, gallium chloride (US Pub. No. 2007/0238143) has been used in a kinase/phosphatase platform in FRET assays where one of the fluorescent species was a conducting, conjugated polymer capable of fluorescence superquenching. The metal ion zirconyl chloride has recently been described as another useful metal ion that associates to phosphates with larger specificity than iron or gallium when complexed to phosphonate groups present on polystyrene microspheres (Feng et al., Mol & Cell. Proteom. 6:1656-1665, 2007). Rather than associating the metal ion to a solid support, small molecule fluorescent sensors chemically modified to contain a phosphonate group have been employed to detect the presence of metal ions in solutions (US 2007-0049761 A1).
[0010] Currently available kinase assays that monitor the accumulation of ADP or depletion of ATP (4, 5) are not adaptable to cellular lysates because they cannot discriminate between the activity of the target of interest and the many other enzymatic events within a cell that convert ATP to ADP. Similarly, assays that rely on secondary readout enzymes, such as proteases suffer from non-specific cleavage by intracellular enzymes.
[0011] Commercially available platforms that are adaptable to cellular lysates and are homogeneous include Invitrogen's (Carlsbad, Calif.) TR-FRET based GFP-fusion protein assays. Since the GFP fusion-protein substrate must be transfected into a cell these assays are not suitable for monitoring differences in a physiologically relevant context. Other cell-based platforms, such as ALPHA Screen-based Surefire (Perkin Elmer, Waltham, Mass.), RayBio (Norcross Ga.), or Bioplex (Hercules, Calif.) rely on antibodies to capture phosphoproteins and are not able to quantify the actual activity that is conferred to a phosphorylated target within a signaling pathway.
[0012] While FRET and FP platforms are popular for monitoring of single enzyme activity in biochemical assays, none of the platforms are conducive to multiplexed applications. The main disadvantage of FRET assays is the necessary spectral overlap between the donor and acceptor fluorophores (15). Therefore, sensors based on FRET can monitor the modulation of only one fluor and are not adaptable to multiplexed applications. While FP-based assays monitor the modulation of only one fluor, for most instruments the readout requires specialized instrument configurations depending on the type of fluor used. The configurations cannot be simultaneously applied, thus making FP-based applications restricted to the readout of only one fluor.
[0013] There remains a need in the art for assays to detect PTM, particularly of enzymes involved in signal transduction. Further, there remains a need in the art for assays capable of simultaneously determining the activity levels of multiple enzymes involved in the same or different signal transduction pathways. These needs and others are met by the present invention.
BRIEF SUMMARY OF THE INVENTION
[0014] In accordance with the present invention, there is provided a method and composition of matter for assaying the activity of an enzyme based on modulation of fluorescence.
[0015] In one embodiment, the present invention provides a composition comprising a substrate complexed to a metal ion. Substrates of the invention may comprise a fluorescent moiety attached to a body portion. Substrates may also comprise one or more phosphoryl groups that may be attached to the body portion. Typically, one or more metal ions may be complexed to the one or more phosphoryl groups. Generally speaking, at least one phosphoryl group and at least one fluorescent moiety are positioned on the body such that at least some fluorescence from the fluorescent moiety is quenched by the metal ion that is complexed to the substrate. In one embodiment, the metal ion is complexed to the substrate via an interaction with at least one phosphoryl group. In one embodiment, the metal ion may be zirconium.
[0016] In some embodiments, the body portion of a substrate of the invention may comprise a peptide. Any peptide that may be acted upon by an enzyme of interest may be used in the practice of the invention. Peptides may be derived from larger sequences (i.e., proteins) that are acted on by an enzyme of interest. In some embodiments, peptides comprise an amino acid sequence that is recognized by an enzyme of interest. An example of a peptide that may be used in the practice of the invention is a peptide comprising the sequence LRRASLG (SEQ ID NO:1, also known as kemptide). This sequence is recognized by protein kinase A (PKA). In the presence of PKA and ATP this peptide is phosphorylated at the serine residue. Another example of a peptide sequence that may be used in the practice of the invention is a peptide comprising the sequence KVEKIGEGTYGVVYK (SEQ ID NO:2) a sequence that is recognized by the protein kinase Fyn. Those of skill in the art are aware of numerous peptide sequences that are acted on by enzymes of interest and peptides comprising such sequences may be used in the practice of the invention. Other suitable peptides include, but are not limited to: GRPRTSSFAEG (SEQ ID NO:3) a sequence that is recognized by Akt1/PKB, p70S6, and MAPKAPK1; GRTGRRNSI (SEQ ID NO:4) a sequence that is recognized by PKA; ARKRERTYSFGHHA (SEQ ID NO:5) a sequence that is recognized by AKT/PKB and rac; KRELVEPLTPSGEAPNQALLR (SEQ ID NO:6) a sequence that is recognized by ERK1/2 and p44/p42MAPK; RRAAEELDSRAGSPQL (SEQ ID NO:7) a sequence that is recognized by GSK3; PLARTLSVAGLPGKK (SEQ ID NO:8) a sequence that is recognized by camKII; KQAEAVTSPR (SEQ ID NO:9) a sequence that is recognized by PKC; RFARKGSLRQKNV (SEQ ID NO:10) a sequence that is recognized by PKC and PKA; APRTPGGRR (SEQ ID NO:11) a sequence that is recognized by p44MAPK, p42MAPK, ERK1/2, and p38α, GEEPLYWSFPAKKK (SEQ ID NO:12) a sequence that is recognized by Blk, Btk, ckit, IGF-1R, vEGF-R1, and src.
[0017] The body portion of a substrate of the invention may be of any chemical composition that is recognized by an enzyme of interest. Body portions of the substrates of the invention may comprise, for example, lipids, nucleotides (e.g., cyclic nucleotides such as cAMP and cGMP), oligonucleotides, and/or carbohydrates. Examples of suitable lipids include, but are not limited to, sphingosine, diacyl glycerol, phosphatidyl-myo-inositol, lipids involved in cellular signaling, phosphatidylinositol phosphates (PIPs), prostaglandins, steroid hormones such as estrogen, testosterone and cortisol, and oxysterols such as 25-hydroxy-cholesterol. Suitable carbohydrates include, but are not limited to, myo-inositol, glucose, fructose, and sorbitol.
[0018] Substrates of the invention may comprise one or more fluorescent moieties. Any fluorescent moiety known to those skilled in the art may be used. Suitable examples of fluorescent moieties that may be used in the practice of the invention include, but are not limited to, TAMRA dyes, BODIPY dyes, fluorescein, CHROMEO dyes, DyLight dyes, cyanine dyes, R-phycoerythrin (PE), fluorescein, lissamine rhodamine B, Texas Red, allophycocyanin (APC), Cy3.5, Cy 5.5, and Cy7.
[0019] In one embodiment, the present invention provides a method of detecting a kinase enzyme in a sample. Such a method may comprise contacting the sample with a substrate for the kinase enzyme. Typically, as described above, a substrate for use in the methods of the invention may comprise a fluorescent moiety. Contacting the sample with the substrate is typically performed under condition in which the enzyme of interest is known to be active. Such conditions may include pH, monovalent cation (e.g., Na+) concentration, divalent cation (e.g., Mg 2+ ) concentration, etc. Determination of such conditions is routine in the art. After contacting the sample with substrate, the reaction is allowed to proceed for a desired period of time. The reaction mixture may then be contacted with a sensor of the invention. Sensors of the invention typically comprise a metal ion, for example, zirconium. Fluorescence may then be detected from the substrate, wherein a decrease in fluorescence indicates the presence of the kinase enzyme.
[0020] Any type of kinase enzyme may be assayed using the methods of the invention by simply varying the make up of the substrate such that the substrate comprises a recognition site for the enzyme of interest. This is typically accomplished by varying the body portion of the substrate. A body portion of a substrate may comprise a peptide, a lipid and/or a carbohydrate depending on the enzyme of interest to be assayed. In one embodiment, the body portion comprises a peptide, for example, a peptide comprising an amino acid sequence selected from the group consisting of SEQ ID NOs:1-12. In another embodiment, the body portion comprises a lipid, for example, a lipid selected from a group consisting of sphingosine, diacyl glycerol, phosphatidyl-myo-inositol, phosphatidylinositol phosphates (PIPs), prostaglandins, steroid hormones such as estrogen, testosterone and cortisol, and oxysterols such as 25-hydroxy-cholesterol. In another embodiment, the body portion comprises a carbohydrate, for example, a carbohydrate selected from the group consisting of myo-inositol, myo-inositol, glucose, fructose, and sorbitol. Substrates for use in assaying kinase enzymes typically comprise a fluorescent moiety, for example, a fluorescent moiety selected from a group consisting of TAMRA dyes, BODIPY dyes, fluorescein, CHROMEO dyes, DyLight dyes, cyanine dyes, R-phycoerythrin (PE), fluorescein, lissamine rhodamine B, Texas Red, allophycocyanin (APC), Cy3.5, Cy 5.5, and Cy7.
[0021] In one embodiment, the present invention provides a method of detecting a phosphatase enzyme in a sample. Such a method may comprise contacting the sample with a substrate for the phosphatase enzyme. Typically, as described above, a substrate for use in the methods of the invention may comprise a fluorescent moiety. Contacting the sample with the substrate is typically performed under condition in which the enzyme of interest is known to be active. Such conditions may include pH, monovalent cation (e.g., Na+) concentration, divalent cation (e.g., Mg 2+ ) concentration, etc. Determination of such conditions is routine in the art. After contacting the sample with substrate, the reaction is allowed to proceed for a desired period of time. The reaction mixture may then be contacted with a sensor of the invention. Sensors of the invention typically comprise a metal ion, for example, zirconium. Fluorescence may then be detected from the substrate, wherein an increase in fluorescence indicates the presence of the phosphatase enzyme.
[0022] Any type of phosphatase enzyme may be assayed using the methods of the invention by simply varying the make up of the substrate such that the substrate comprises a recognition site for the enzyme of interest. This is typically accomplished by varying the body portion of the substrate. A body portion of a substrate may comprise a peptide, a lipid, a nucleotide, and/or a carbohydrate depending on the enzyme of interest to be assayed. In one embodiment, the body portion comprises a peptide, for example, a peptide comprising GLGF(pY)MAYG (SEQ ID NO:13), which acts a substrate for the phosphatase PTP-1B. In another embodiment, the body portion comprises a lipid, for example, a lipid selected from a group consisting of sphingosine phosphate, diacyl glycerol phosphate, phosphatidyl-myo-inositol phosphate. In another embodiment, the body portion comprises a lipid, for example, a lipid selected from a group consisting of sphingosine, diacyl glycerol, phosphatidyl-myo-inositol, phosphatidylinositol phosphates (PIPs), prostaglandins, steroid hormones such as estrogen, testosterone and cortisol, and oxysterols such as 25-hydroxy-cholesterol. In another embodiment, the body portion comprises a carbohydrate, for example, a carbohydrate selected from the group consisting of myo-inositol, myo-inositol, glucose, fructose, and sorbitol. Substrates for use in assaying phosphatase enzymes typically comprise a fluorescent moiety, for example, a fluorescent moiety selected from a group consisting of TAMRA dyes, BODIPY dyes, fluorescein, CHROMEO dyes, DyLight dyes, cyanine dyes, R-phycoerythrin (PE), fluorescein, lissamine rhodamine B, Texas Red, allophycocyanin (APC), Cy3.5, Cy 5.5, and Cy7.
[0023] In one embodiment, the present invention provides a method of detecting a protease enzyme in a sample. Such a method may comprise contacting the sample with a substrate for the protease enzyme. Typically, as described above, a substrate for use in the methods of the invention may comprise a fluorescent moiety and a phosphoryl group separated by a peptide sequence comprising the recognition site for the protease enzyme. The fluorescent moiety and the phosphoryl group are typically situated such that in the presence of a sensor of the invention, fluorescence is quenched. When the peptide is cleaved by the action of the protease, the phosphoryl group and the fluorescent moiety become separated and the fluorescent moiety is no longer quenched. Contacting the sample with the substrate is typically performed under condition in which the enzyme of interest is known to be active. Such conditions may include pH, monovalent cation (e.g., Na+) concentration, divalent cation (e.g., Mg 2+ ) concentration, etc. Determination of such conditions is routine in the art. After contacting the sample with substrate, the reaction is allowed to proceed for a desired period of time. The reaction mixture may then be contacted with a sensor of the invention. Sensors of the invention typically comprise a metal ion, for example, zirconium. Fluorescence may then be detected from the substrate, wherein an increase in fluorescence indicates the presence of the protease enzyme.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 shows various schematic representations of assays of the invention. FIG. 1A is a schematic of a fluorescence quench assay of the invention. FIG. 1B is a schematic representation of a FP assay of the invention using a fluorescent small molecular sensor. FIG. 1C shows the use of the present invention for assaying phosphodiesterase activity. FIG. 1D shows an embodiment of the invention using intramolecular quenching. FIG. 1E shows an embodiment invention using intermolecular quenching.
[0025] FIG. 2A is a plot of relative fluorescence units (RFU) versus % phosphopeptide showing a linear dose response using TAMRA-labeled peptide. FIG. 2B is a plot of relative fluorescence units (RFU) versus % phosphopeptide showing a linear dose response using Fluorescein-labeled peptide.
[0026] FIG. 3A is a line graph plot of relative fluorescence units (RFU) versus concentration of kinase showing the results of an assay for protein kinase A. FIG. 3B is a line graph plot of relative fluorescence units (RFU) versus concentration of kinase showing the results of an assay for Fyn kinase. FIG. 3C is a line graph plot of relative fluorescence units (RFU) versus concentration of kinase showing the results of an assay for sphingosine kinase I. FIG. 3D is a line graph plot of relative fluorescence units (RFU) versus concentration of kinase showing the results of an assay for phosphoinositide-3-kinase. FIG. 3E is a line graph plot of % phospholipid versus concentration of kinase showing the results of an assay for phosphoinositide-3-kinase.
[0027] FIG. 4A is a plot of RFU versus time at various concentrations of protein kinase A. FIG. 4B is a plot of RFU versus time at various concentrations of inhibitor at an enzyme concentration of 20 nM.
[0028] FIG. 5 is a plot of delta RFU versus ATP concentration in a phosphosinositide-3-kinase a assay showing ATP tolerance curve for the assay.
[0029] FIG. 6 is a plot of velocity versus substrate concentration for the kinase PKA.
[0030] FIG. 7A is a plot of RFU (perpendicular) versus % phosphoprotein at various fluorescein-labeled phosphoprotein concentrations.
[0031] FIG. 7B is a plot of RFU (parallel) versus % phosphoprotein at various fluorescein-labeled phosphoprotein concentrations.
[0032] FIG. 7C is a plot of the ratio of RFU perpendicular to RFU parallel showing simultaneous monitoring of fluorescence quench and polarization of dye-labeled substrate as a function of phosphorylation.
[0033] FIG. 8 is a bar graph showing delta FP of sensor with increased concentration of zirconium ion.
[0034] FIG. 9 is a plot of RFU versus wavelength demonstrating transferred fluorescence emission of a dye-labeled protein upon binding to sensor. The fluorescence energy is transferred from the sensor to the Dylight 647 fluorophore and then emitted.
[0035] FIG. 10 is a schematic depicting use of sensor for detection of enzymatic activities other that kinase/phosphatase activity, for example, protease, methylase and/or acetylase activities.
[0036] FIG. 11 is a representative synthesis scheme used to generate phosphonate sensor.
[0037] FIG. 12 shows simultaneous monitoring of fluorescence quench of substrates labeled with Hylyte488, TAMRA and Chromeo642.
[0038] FIG. 13 is a bar graph showing specific detection of activity of a phosphatase in the presence of several substrates.
[0039] FIG. 14 is a plot of RFU versus concentration of PKA for Chromeo642-labeled peptide compared to TAMRA labeled peptide.
[0040] FIG. 15A is a graph showing % activity as a function of time for a reaction containing Chromeo642-labeled peptide±0.5 nM PKA and ±ATP. FIG. 15B is a graph showing % activity as a function of time for a reaction containing TAMRA-labeled peptide and zero, 3 nM or 6 nM PKA±ATP.
[0041] FIG. 16A is a bar graph showing RFU as a function of μg of cell lysate added ±ATP. FIG. 16B is a bar graph showing delta RFU between reactions containing ATP and those not containing ATP as a function of μg lysate added.
[0042] FIG. 17A is a bar graph showing RFU at various concentration of ATP in the presence (solid bar) and absence (striped bar) of 25 μg lysate. FIG. 17B is a line graph showing signal to background ratio (S/B) as a function of the ATP concentration in the reaction mixture.
[0043] FIG. 18A is a line graph showing the change in relative fluorescence observed as a function of inhibitor concentration for the inhibitors 5-24 (squares) and staurosporine (filled circle). FIG. 18B is a bar graph showing RFU as a function of inhibitor concentration with the inhibitors LR294002 and PI3K I-2±ATP.
[0044] FIG. 19 shows the results of biochemical assays for an enzyme dose response curve of phosphodiesterase 4A1A. FIG. 19A shows the results obtained using 2 μM fluorescein labeled cAMP substrate. FIG. 19B shows the determination of Z'factor using PDE4A1A concentrations of 1 nM, 0.25 nM and 0 nM and 2 μM fluorescein labeled cAMP substrate. FIG. 19C shows the results of a kinetic dose response analysis using various enzyme concentrations and 2 μM fluorescein labeled cAMP substrate. Sensor (zirconyl chloride) was used at 100 μM.
[0045] FIG. 20 shows a Michaelis-Menten fit of slopes derived from a kinetic experiment in which various concentrations of fluorescein-labeled substrate were incubated with 2 μM fluorescein labeled cAMP substrate, 1 nM enzyme, and 100 μM sensor (zirconyl chloride).
[0046] FIG. 21 shows line curves of inhibition biochemical assays for PDE4A1A (3 nM) with various concentrations of the inhibitor RO20-1724 (filled circles) or IBMX (open diamonds) in endpoint ( FIG. 21A ) or kinetic ( FIG. 21B ) modes. Assays were conducted with fluorescein-labeled cAMP at 2 μM and sensor (zirconyl chloride) at 100 μM.
[0047] FIG. 22 shows cleavage of fluorescein-labeled cAMP as a function of various concentrations of lysates using kinetic monitoring. Assays were conducted with fluorescein-labeled cAMP at 2 μM and sensor (zirconyl chloride) at 100 μM.
[0048] FIG. 23 is a bar graph showing simultaneous monitoring of quench of fluorescein-labeled cAMP at 1.5 μM (left axis) and TAMRA-labeled cGMP at (right axis) as a function of the concentration of mouse brain lysate.
[0049] FIG. 24A is a schematic that explains the experimental data shown in FIG. 24B . In the presence of cAMP, PKA activity is stimulated resulting in phosphorylation of labeled kemptide substrate and an increase in the delta RFU of the kemptide (right axis). PDE4A 1A hydrolyzes c-AMP to AMP resulting in an increase in the delta RFU (left axis). In the presence of the PDE inhibitor IBMX, hydrolysis of cAMP is inhibited resulting in hight concentrations of cAMP and higher PKA activities. FIG. 24B is a line graph of the change in relative fluorescence units (delta RFU) in fluorescien-labelled cAMP (1.5 μM, left axis) and Chromeo642-labeled LRRASLG (3 μM, right axis) caused by PKA present in 2 μg lysate in the presence of varying amounts of the non-selective PDE inhibitor IBMX. PKA activity increases with increasing amount of IBMX (filled squares) and PDE activity decreased with increasing amounts of IBMX (empty circles).
DETAILED DESCRIPTION OF THE INVENTION
[0050] Diseases such as cancer, diabetes and infection are the result of an inappropriate cellular response to extracellular or intracellular cues, which elicit a specific phenotypic response, such as proliferation or apoptosis. These cellular cues are mediated by a complex interconnected network of bio-molecules that are commonly activated or deactivated by PTM, for example, phosphorylaton. To enhance drug discovery an approach is needed that provides information on signaling networks as a whole rather than simply on one or two components. The present invention provides a multiplex technique that can quantitatively measure variations of multiple protein activities within one or across several signaling pathways. The assays of the invention provide techniques that are both sensitive and fast. The present invention makes use of the fact that a sensor based on electron transfer does not require spectral overlap between donor and acceptor molecules, and one of this type would be ideally suited for multiplexing applications.
[0051] Sensors
[0052] The present invention provides a novel sensor that may be used to detect and/or quantify the presence of one or more enzymatic activities in a sample.
[0053] In one embodiment, a sensor of the invention may comprise a fluorescent chelator and a metal ion associated to the chelator. Suitable metal ions include, but are not limited to, zirconium ions. The chelator may be a phosphonated fluorescent molecule that can be generated as described in FIG. 11 , or may be purchased commercially from, for example, Active Motif, San Diego, Calif. Examples of phosphonate fluorescent dyes that may be used in this embodiment include, but are not limited to, Chromeo 547 or Chromeo 642 fluors. The structures of these dye fluors are provided in the following structures.
[0000]
[0054] Embodiments of this type (i.e., bi-molecular sensors) are useful for assays in which fluorescence can be transferred from the sensor fluor to an acceptor fluor (see FIG. 9 ). In addition, sensors of this type may be immobilized on solid surfaces such as glass or plastic via covalent tether or using avidin coated surfaces in conjunction with biotinylated Chromeo642 or Chromeo547, or using streptavidin labeled Chromeo642 or Chromeo547 in conjunction with biotinylated surfaces.
[0055] In another embodiment, a sensor of the invention may consist solely of a metal ion (e.g., a zirconium ion). The metal ion may be provided as a suitable salt. In one embodiment, a sensor of the invention may be zirconium which may be supplied as zirconyl chloride. The metal ion can associate with phosphates on a substrate body and quench fluorescence via intermolecular quenching ( FIG. 1E ) or it can form a ternary complex with phosphonates on fluors (eg Chromeo642 or chromeo547) and phosphates on the body of the substrate ( FIG. 1D ). The sensors of the invention provide numerous advantages over sensors of the prior art including low cost of materials, high sensitivity, reproducibility, long shelf-life, and the ability to associate with any substrates such as proteins. When proteins such as an antibody are labeled with zirconyl chloride, the antibody sensor can readily quench the fluorescence of a fluorescent target molecule upon specific binding. This allows easy generation of a binding sensor via association of zirconyl chloride to phosphate groups present in the antibody protein.
[0056] In one embodiment, the present invention provides a unique sensor that may be used to detect kinase and phosphatase activities by metal ion association to phosphoryl groups. When a fluor-labeled substrate is phosphorylated by a kinase, association of the sensor to the phosphate group brings the fluor and the sensor into proximity allowing electron transfer to occur. Sensors of the invention may operate by inter and/or intra-molecular mechanisms (FIGS, 1 E and 1 D, respectively).
[0057] As shown below, peptide substrates labeled with Fluorescein, TAMRA and Chromeo642 can be quenched simultaneously with this sensor in the presence of cellular lysates. In some embodiments, the metal ion may be associated with a chelator, such as a phosphonate. In some embodiments, the chelator may comprise a bi-phosphonated molecule.
[0058] Substrates
[0059] Substrates for use in the assays of the invention typically comprise a body portion, a fluorescent moiety, and optionally, a phosphoryl moiety.
[0060] The body portion of the substrates of the invention is limited only by the enzyme to be assayed. The body portion will typically be the same as or mimic the naturally occurring substrate of the enzyme of interest. A body portion may be of any chemical make up, for example, may be a peptide or protein, a lipid, a carbohydrate, a nucleic acid etc. Any molecule that is acted upon by an enzyme and to which a fluorescent moiety may be attached can be used as the body portion of a substrate of the invention.
[0061] For assays involving enzymes that add a phosphoryl group (e.g., kinases), the body portion of substrate may comprise a hydroxyl group to which a phosphoryl group may be transferred. When assaying a protein kinase, the substrate may comprise an amino acid comprising a hydroxyl group to which a kinase can transfer a phosphoryl group (e.g., a serine and/or tyrosine).
[0062] For assays involving the removal of a phosphoryl group (e.g., phosphatase reactions) a substrate of the invention will typically comprise a phosphoryl group attached to the body portion of the substrate.
[0063] For assays involving cleavage reactions (e.g., phosphodiesterases, proteases, lipases, etc), the body portion of the substrates of the invention will typically comprise a cleavage site for the enzyme of interest. As a general rule, the cleavage site will be positioned such that after being acted upon by the enzyme, the body portion will be cleaved into two fragments, one of which may comprise a phosphoryl moiety and one of which may comprise the fluorescent moiety. Thus action of the enzyme of interest results in separation of the phosphoryl moiety from the fluorescent moiety and this separation results in a detectable modulation of the fluorescent properties of the substrate (i.e., change in RFU and/or FP). In one embodiment, a phosphodiesterase may be assayed using the sensors of the invention. After a cyclic nucleotide is acted upon by a phosphodiesterase, a phosphate group is produced that can then interact with a sensor of the invention.
[0064] Examples of protease cleavage sites that may be incorporated into the substrates of the invention include, but are not limited to, a cleavage site for aminopeptidase M (e.g., amino terminal L amino acids, a cleavage site for carboxypeptidase A which cleaves carboxy-terminal L-amino acids, a cleavage site for cathepsin C which cleaves amino terminal dipeptides, a cleavage site for chymotrypsin which cleaves after F, T or Y; a cleavage site for collagenase which cleaves peptide containing the sequence P—X-G-P after X where X is any amino acid; a cleavage site for endoproteinase Arg-C whcich cleaves peptides containing R—X after R where X is any amino acid, a cleavage site for endoproteinase Asp-N which cleaves peptides containing D and cystic acid before the D or cystic acid, endoproteinase Lys-C which cleaves peptides containing K after the K; a cleavage site for enterokinase, which cleaves peptides containing D-D-D-D-K after the K, a cleavage site for Factor Xa which cleaves peptides containing R after the R, a cleavage site for kallikrein, which cleaves peptides containing R after some R, a cleavage site for plasmin, which cleaves peptides containing K or R after the K or R, and a cleavage site for thrombin which cleaves peptides containing R after the R.
[0065] Any suitable fluorescent moiety known to those skilled in the art may be used in the practice of the invention. Suitable fluorescent moieties include, but are not limited to, TAMRA dyes, BODIPY dyes, fluorescein, CHROMEO dyes, DyLight dyes, cyanine dyes, R-phycoerythrin (PE), fluorescein, lissamine rhodamine B, Texas Red, allophycocyanin (APC), Cy3.5, Cy 5.5, and Cy7.
[0066] Assays
[0067] In general, the methods of the present invention involve assaying the activity of an enzyme of interest by contacting the enzyme with a population of fluorophore labeled substrate in an aqueous enzymatic reaction mixture and allowing the enzymatic reaction to proceed for a desired period of time and temperature. The reaction is then brought into contact with a sensor, which may be fluorescent or non-fluorescent. A sensor of the invention may comprise or be associated with zirconyl chloride and may form a complex with the phopshoiylated substrate. This complex of sensor and substrate results in fluorescence modulation of the fluorophore labeled substrate. Complexes formed as described above can be detected using unlabeled substrates by monitoring alterations of FP of the sensor. By measuring the change of the observed intensity of fluorescence or fluorescence polarization from the mixture and relating the same to that of a reference, a differential signal can be identified and quantified. The amount of change of fluorescent signal of the sample in indicative of the final state of the fluorophore labeled substrate population, and, in turn, reflects enzymatic activity.
[0068] The methods of this invention are applicable for the assay of kinase, phosphatase, and/or phosphodiesterase activities using peptide, proteins, lipids, carbohydrates, and/or nucleic acids (e.g., cyclic nucleotides) as substrates. The enzyme is reacted with substrate to produce an end product containing a phosphoryl group having binding affinity for the metal ion. In one embodiment the substrate contains an attached fluorophore label and its fluorescence quench is monitored following conclusion of the enzymatic reaction upon addition of a sensor to the reaction mix. A further embodiment demonstrates the linearity of signal that can be obtained using substrates labeled with different fluorophores such as Fluorescein, Hilyte488, TAMRA or BODIPY-TMR. Another embodiment describes the kinetic monitoring that can be accomplished by adding fluorescent sensor to the reaction mix and detecting fluorescence quench as it occurs in real time. Another embodiment demonstrates the ability of simultaneous monitoring of the distinct emissions of several fluorophores with the sensor in defined medium or in complex cellular lysates. In another embodiment the change in FP of a fluorescent-labeled substrate is quantified. Another embodiment demonstrates the ability of monitoring sensitized emission from the sensor to a fluorophore labeled protein. An additional embodiment demonstrates the monitoring of measuring changes in FP of the sensor in the presence of unlabeled peptide substrate.
[0069] An assay of the invention may configured in a variety of ways. For example, a kinase assay can result in either a decrease (fluorescence quench) or an increase (FP or transferred emission) in the detected fluorescent signal. The signal changes are proportional to enzyme activity and result in linear dose responses. In a particular embodiment, a substrate comprises a fluorescent moiety comprising a phosphonate moiety. The substrate may also comprise a phosphate moiety positioned such that, upon addition of a metal ion (e.g., a zirconium ion) both the phosphonate and the phosphate are coordinated to the metal ion. The phosphate may be attached to the substrate before the reaction (for example, in a phosphatase assay) or as a result of the reaction (for example, in a kinase assay) so that addition or removal of the phosphate group can be monitored by the changes in fluorescence quenching observed.
[0070] Increased sensitivity can be obtained using fluorophores that are labeled with a phosphonate by virtue of providing a bridge between the phosphonate-sensor-phosphate that brings the sensor into closer proximity to the fluorophore, resulting in enhanced quench.
[0071] With respect to phosphatase assays, in fluorescence quench assays, the initial starting enzymatic reaction will be more highly quenched prior to reaction by virtue of the fluorophore labeled substrate being already phosphorylated. Thus the observed fluorescence emission from the population after enzymatic removal of the phosphoryl group will increase.
[0072] Protease and/or lipase activity can also be measured by the method of the present invention. In this case a substrate is selected to have a cleavage site between the attached fluorophore and the phosphoryl group. Upon cleavage with a lipase or protease, the sensor is added and allowed to associate to the phosphate. In the absence of cleavage, fluorescence is quenched due to the proximity of the substrate fluorophore with the sensor, whereas in the presence of cleavage, the fluorescent species are removed from another to an extent that disrupts energy transfer.
[0073] Another aspect of the invention is making use of phosphoryl groups as a biological tag with which fluorescent sensor can bind via metal-ion association. In this manner the presence of other post-translationally active enzymes, such as methylases and transferases can be monitored. In this case, a substrate is selected which is labeled with a fluorophore at one site and with a phosphoryl group at another site. The sequence of the substrate is such that it contains a recognition site for a specific post-translationally active enzyme that is also recognized by a cleavage enzyme (e.g., a protease or a lipase). In the presence of activity of the post-translationally active enzyme, a chemical group such as a methyl or acetyl group is transferred to the substrate, which interferes with the ability of substrate to be cleaved by a secondary cleavage enzyme. Upon addition of sensor to the substrate, a modulation in fluorescence can be observed as described above.
[0074] The binding or disassociation of two proteins can be detected by monitoring modulation of FP of one of two proteins tagged with sensor via metal ion/phosphate interaction following binding or disassociation with another protein.
[0075] A further embodiment of the invention is a synthesis scheme designed to produce a composition comprising a fluorophore with a phosphoryl group as a receptor to which a metal ion can bind. The complex retains its ability to associate with phosphoryl groups present on biological substrates and causes modulation of fluorescence of the substrate label when a complex is formed. Suitable fluorophores span the range of the visible spectrum (˜400 nm-750 nm) and are able to act as either donor or acceptor fluorophores to a fluorophore labeled substrates via energy or electron transfer mechanism. Another embodiment of the invention describes the preparation of zirconyl chloride complexes that are capable of associating with phosphates present on fluorophore labeled substrates or to phosphonate groups present on the fluorophore.
[0076] Yet a further embodiment of the inventions provides a kit comprised of one or more of a metal ion (e.g., Zr +4 ), a peptide, a peptide labeled with a phosphonate-modified fluorophore (e.g., a Chromeo fluorophore), association buffer, postreaction buffers, sensor dilution buffers and reaction buffers appropriate for an enzyme of interest as well as an instruction booklet describing the manner in which the assay can be accomplished with respect to one or more enzymes. The kit may include a synthetically prepared calibrator to function as external reference. The calibrator may comprise a synthetic substrate labeled with a phosphoryl group. Labeled substrates (e.g., peptides) may be provided in kits of the invention or may be supplied by the user. Substrates may be labeled using any suitable label including, but not limited to, fluorescein and its derivatives, TAMRA and its derivatives, Cy5 and its derivatives or any fluorescent molecule spanning the UV-visible range.
[0077] The present invention provides assays that can measure the phosphorylation of any substrate by any kinase with one universal approach. Such generic assays include those based on metal ion chelates that can directly associate to phosphorylated proteins and peptides. Without wishing to be bound by theory, the present invention makes use of electron transfer quenching of a fluor-labeled substrate by a metal ion ( FIG. 1 ). The metal ion may be used alone or may be coordinated with a chelator, for example, a phosphonate such as those is present on Chromeo fluors to form a stable complex. The complex retains its ability to associate to phosphoryl groups present on serine, threonine or tyrosine amino acids on peptide substrates, to phosphorylated lipids or to DNA substrates. Upon association of the complex to the phosphoryl groups of a dye-labeled substrate, the metal ion is brought into a proximity that allows electron transfer to occur. As a result, the fluorescence intensity of the substrate decreases proportionally to the increased percentage of phosphorylation.
[0078] The fluorescence of a fluorophore label on an enzymatic substrate can be altered by the presence of a sensor of the invention when brought into proximity to the substrate fluorophore, for example, via metal-ion and phosphate interaction. The change in fluorescence of the substrate can be monitored as fluorescent quench, transferred emission or change in FP. Alternatively, modulation of FP as well as fluorescence quench of a fluorophore labeled substrate can be measured simultaneously whilst monitoring the parallel and perpendicular emission required for FP. Additionally, changes in FP of the sensor can be measured in the presence of unlabeled substrate. Additionally, simultaneous modulation of fluorescence quench of substrates labeled with various fluorophores can be measured in multiplexed mode. Finally, measurement can be made in defined assay conditions as well as in the presence of cellular lysates, enabling the dissection of signaling pathway events within lysates of cells.
[0079] In some embodiments, activity assays of the invention quantify phosphorylation of a synthetic substrate by an activated kinase. In some embodiments, the present invention may provide assays of enhanced sensitivity. Such assays may comprise conjugation of the chelating fluors directly to biomoelcules, for example, peptide substrates of kinase and/or phosphatase enzymes. As shown below in the examples, this approach improved the sensitivity of Protein Kinase A (PKA) activity detection 35-fold using Chromeo642 labeled substrates as opposed to substrates labeled with TMR or Fluorescein.
[0080] Depending on the location of the chelating group, inter- or intra-molecular quenching is achieved: with the inter-molecular sensor the Chromeo-metal ion complex is assembled and added to a fluor-labeled substrate following incubation with a kinase and ATP. With the intra-molecular approach the metal ion co-ordinating fluor is directly conjugated to the substrate and metal ion coordinated at the end of the reaction. We have shown that intra molecular quenching using a Chromeo642 labeled substrate results in sensitivities of kinase detection that are 35-fold higher than those that can be achieved using peptides labeled with TAMRA or Fluorescein ( FIG. 14 ). In some embodiments, instead of using phosphonated fluors (e.g., Chromeo fluors) as a partner for the formation of an intramolecular ternary complex, the distance between the metal ion and fluor can be reduced by adding a linker that contains a phosphonate group between the fluor and the first (or last) position of the substrate body. Thus, body of the substrate may comprise a phosphonate group which can interact with the metal ion. Embodiments of this type allow any fluor to be used for labeling substrates allowing for larger multiplexed samples. Any of the above embodiments and combinations thereof can be used in multiplex applications to simultaneously detect the presence of multiple enzyme activities in the same sample. We have shown that peptides labeled with either Fluorescein, TMR or Chromeo642 can be quenched individually or simultaneously. The multiplex approach was validated for detection of Protein Phosphatase 1B (PTP-1B) activity in the presence of cellular lysates ( FIG. 13 ).
[0081] Multiplex Assays
[0082] Fluorescence quench can be accomplished by electron transfer rather than by energy transfer. This involves the physical exchange of an electron from the excited acceptor fluor to the donor fluor. The transfer does not involve a dipole-dipole coupling mechanism as is the case for FRET, and therefore molecules capable of electron transfer do not require spectral overlap. One electron transfer acceptor molecule can therefore potentially quench the fluorescence of any fluor. Thus, a sensor that is capable of electron transfer is ideally suited for multiplexing applications.
[0083] Sensors of the invention may be used to conduct homogeneous, multiplexable fluorescent assays. In one example, methods of the invention may be used to simultaneously monitor a plurality (e.g., 2, 3, 4, 5, etc) of enzymes (e.g., kinases and/or phosphatases) involved in one or more signaling pathways. An example of a signaling pathway that can be monitored using the assays of the invention is the phophoinositide kinase 3 (PI3K) pathway, for example, in a human cancer cell line. This profiling of kinase activities within cells has the potential to greatly enhance the diagnosis and treatment of a broad range of human diseases.
[0084] To obtain cellular profiles of signaling pathways, the present invention provides a multiplexable, homogeneous kinase activity assay, which has a broad spectrum of application and is adaptable to cellular lysates and high through-put. The present invention may be practiced using commercially available fluorescent moieties, for example, the Chromeo series of fluors from ActiveMotif. The present invention has allowed the development of inter- and intra-molecular sensors and quantification of variations in cellular signaling pathways with higher sensitivity than otherwise possible. In contrast, electron and charge transfer quenching can be accomplished using only one fluorophore, which does require spectral overlap with a donor fluorophore. The ability to quench the emission of a variety of fluorophores enables electron/charge transfer sensors to be used in multiplex application. The use of a non-fluorescent sensor enables the ability to add large concentrations of sensor without generating background fluorescence that can interfere with the assay. In this manner, non-specific binding of the sensor to reagents commonly present in assays such as ATP, EDTA and protein which can cause decease in assay performance can be overcome by addition of higher amounts of sensor. Thus optimized assays afford high tolerance to ATP and substrate, allowing accurate determination of substrate and ATP Km. Additionally, assays are adaptable to large amounts of proteins such as is present in cellular lysates and thus enable monitoring of endogenous enzyme activities. The combined ability to generate highly sensitive assays in cellular lysates in a multiplex fashion enables dissection of signaling pathways networks in response to exogenous stimuli such as administration of chemical compounds that alter the activity of some components of the signaling pathway.
[0085] It will be readily apparent to one of ordinary skill in the relevant arts that other suitable modifications and adaptations to the methods and applications described herein are obvious and may be made without departing from the scope of the invention or any embodiment thereof. Having now described the present invention in detail, the same will be more clearly understood by reference to the following examples, which are included herewith for purposes of illustration only and are not intended to be limiting of the invention.
EXAMPLES
Example 1
[0086] General Scheme for Assays of the Present Invention.
[0087] FIG. 1 provides a schematic representation of one embodiment of the present invention. As shown in FIG. 1 , assays of the invention may be quench assays or FP assays.
[0088] Typically, assays of the invention may involve 2 steps. In a first step, a fluorescent-dye-labeled substrate (black circles with starburst) is contacted with a sample suspected of having one or more enzymatic activities, e.g.,protease activity, kinase activity, lipase activity, phosphodiesterase activity, and/or phosphatase activity.
[0089] In situations where detecting kinase activity is desirable, the substrate is contacted with the sample in a reaction buffer that comprises ATP. The substrate may comprise an amino acid sequence that is specifically recognized by a kinase of interest. The reaction is allowed to proceed for a selected period of time. The substrate may be phosphorylated by the kinase of interest present in the sample. In step 2, a sensor molecule is added to the reaction mixture and incubated for a selected period of time. The sensor associates with the phosphoryl group on the substrate molecules that have been acted on by the kinase of interest. Following association of the sensor (grey star) to the phosphorylated substrate, fluorescence quench of the substrate is monitored. The fluorescence intensity of the substrate decreases proportionally to the increased percentage of phosphorylation. Fluorescence polarization of dye-labeled substrate is detected as increase in fluorescence polarization signal ( FIG. 1B ).
[0090] In situations where detecting phosphatase activity is desirable, the substrate is contacted with the sample in a reaction buffer. The substrate may comprise an amino acid sequence that is specifically recognized by a phosphatase of interest that comprises a phosphorylated residue. The reaction is allowed to proceed for a selected period of time. The substrate may be de-phosphorylated by the phophatase of interest present in the sample. In step 2, a sensor molecule is added to the reaction mixture and incubated for a selected period of time. The sensor associates with the phosphoryl group on the substrate molecules that have not been acted on by the phosphatase of interest. Following association of the sensor (grey star) to the remaining phosphorylated substrate, fluorescence quench of the substrate is monitored. The reduction in quenching (i.e., increase in fluorescence intensity) of the de-phosphorylated substrate is proportional to the increased percentage of de-phosphorylation. Fluorescence polarization of dye-labeled substrate is detected as a decrease in fluorescence polarization signal.
[0091] In situations where detecting phosphodiesterase activity is desirable, the substrate is contacted with the sample in a reaction buffer. The substrate may comprise a fluor-labeled cyclic nucleotide (e.g., cAMP or cGMP) or analog thereof that is specifically recognized by a phosphodiesterase of interest ( FIG. 1C ). The reaction is allowed to proceed for a selected period of time. The reaction of the cyclic nucleotide with the phosphodiesterase results in a nucleotide with a phosphate group that can interact with the sensors of the invention. In step 2, a sensor molecule is added to the reaction mixture and incubated for a selected period of time. The sensor associates with the phosphoryl group on the substrate molecules that have been acted on by the phosphodiesterase of interest.
[0092] FIG. 1D is a schematic of intramolecular quenching in which a zirconyl sensor forms a ternary complex between a phosphate on the body portion of a substrate and with a phopshonate on the fluor. In contrast, intermolecular quenching ( FIG. 1E ) is achieved using a zirconyl sensor or a bimolecular sensor, which associates to phosphates on the body portion of the substrate.
Example 2
[0093] Calibration Curves
[0094] Fluorescent energy transfer from the dye-labeled substrates to the sensor follow a 1:1 ratio, thus resulting in a linear dose response curve. Substrates labeled with Fluorescein, TAMRA and their analogs are suitable substrates for use with the sensors of the invention. When mixtures of phosphorylated and non-phosphorylated peptides are combined in various ratios, a linear calibrator curve is obtained. As shown in FIG. 2 , the amount of quenching observed is proportional to the amount of phophorylated peptide present in the sample. TMR- or FAM-labeled, LRRASLG (SEQ ID NO:1) peptide substrates (10 μM) were mixed in various ratios of phosphorylated and non-phosphorylated peptide. Following addition of sensor (100 μM Sulforhodamine 101—Zirconyl sensor), linear calibration curves with Signal to Backgrounds (S/B) of 31 and 19.5 for TMR and FAM, respectively, were obtained.
[0095] Sensors of the invention associate with phosphoryl groups on substrates of various chemical natures such as peptide substrates containing phosphoserine, phosphothreonine or phosphotyrosine or phosphorylated lipid substrates. When calibration curves are included in the experimental setup, the precise amount of substrate conversion can be determined.
Example 3
[0096] Enzyme Dose Response Curves
[0097] As shown in FIG. 3 , assays of the invention can be used to detect the presence and to quantify the amount of enzymatic activity present in a sample. FIG. 3A shows the results obtained using protein kinase a (PKA). PKA was serially diluted in assay buffer (10 mM TRIS, 10 mM MgCl 2 , 0.1% BSA, pH 7.2) in the presence of 10 μM ATP and substrate (10 μM HiLyte 488 -LRRASLG). FIG. 3B shows the results obtained with the Fyn, a member of the Src family of kinases. Reaction conditions for Fyn were 50 μM ATP and 10 μM substrate (TAMRA-KVEKIGEGTYGVVYK) in assay buffer (10 mM TRIS, 10 mM MgCl 2 , 0.1% BSA, pH 7.2). As shown in FIG. 3C , Sphingosine Kinase I was reacted with 4 μM TAMRA-Sphingosine in 10 mM TRIS, pH 7.2, 10 mM MgCl 2 , 0.01% Triton X-100 buffer in the presence of 50 μM ATP. FIG. 3D shows the results obtained with Phosphoinositide 3-kinase (PI3K). PI3Kα was reacted in 25 mM HEPES, pH 7.4, 50 mM MgCl 2 , 5 mM DTT and 50 μM ATP with 1 μM BODIPY-TMR-phosphatidylinositol and the product conversion determined ( FIG. 3E ) using back calculation with a calibration curve performed simultaneously with the enzyme reaction. Reactions proceeded for 1 hour at room temperature in wells of a 384-well plate followed by addition of 5 μL stop buffer (1M NaCL; 100 mM MgCl 2 ; 0.015% Brij 35; 0.01% Glycerol; 0.05% NaN 3 ) and 30 μL sensor (100 μM Sulforhodamine 101—Zirconyl sensor) diluted 1:20 in sensor dilution buffer (10 mM MES, pH 6.5; 1M NaCl; 0.01% Triton X-100; 0.05% NaN 3 ). Fluorescence quench was monitored after 1 hour with an excitation wavelength of 450 or 540 nm and 490 or 590 nm emission for HiLyte 488 or BODIPY-TAMRA, respectively. Curve fit was performed using sigmoidal dose response.
Example 4
[0098] Real Time Assays
[0099] The monitoring of enzyme activity as it occurs in “real time” simplifies the optimization of assay parameters, the establishment of Michaelis-Menten constants for substrate and ATP well as the determination of the mode of action of inhibitors. In contrast to other detection platforms (e.g., other metal ion-phosphate-based systems), the sensors used in this invention associate with phosphate at physiological pH, thus allowing monitoring of actual enzyme activity as it occurs.
[0100] The results of a real time assay are shown in FIG. 4 . Various dilutions of PKA in assay buffer and 50 μM ATP were added to wells of a 384-well plate in the presence of 250 nM sensor ( FIG. 4A ). Dilutions of Staurosporine were added to assay buffer containing 50 μM ATP in the presence of 250 nM sensor ( FIG. 4B ). Fluorescence quench was monitored at 450 nm excitation and 490 nm emission in 1-minute intervals.
Example 5
[0101] Effects of ATP on Assay Sensitivity
[0102] The sensor tolerates concentrations of ATP up to 1 mM with minimal loss of signal. This allows to establish relevant ATP K m and further, the screening of structurally diverse libraries for non-ATP competitive inhibitors, which requires high ATP tolerance of the screening platform.
[0103] FIG. 5 shows an ATP tolerance curve for PI3Kα. BODIPY-TMR Phosphatidylinositol (1 μM) was added to various concentrations of ATP in the presence or absence of 44 nM PI3Kα and the reaction stopped by addition of stop buffer. Sensor was added and the delta RFU between reactions with and without enzyme calculated.
Example 6
[0104] Effects of Substrate Concentration on Assay Sensitivity
[0105] In contrast to most fluorescence-based platforms, the sensor tolerates high concentrations of substrate. Substrate concentrations can vary between 100 nM to 200 μM, which allows establishing relevant K m and identification of substrate-competitive inhibitors in the presence of high concentrations of substrate.
[0106] FIG. 6 shows a Michaelis-Menten Plot for substrate. PKA (12 nM) and sensor were added to various concentrations of Hilyte 488 -labeled Kemptide (a consensus sequence substrate for PKA having the amino acid sequence LRRASLG) and substrate conversion monitored in kinetic mode using 450 nm excitation and 490 nm emission. Slopes were plotted against the concentration of substrate and V max and K m calculated using Michaelis-Menten equation in GraphPad Prism.
Example 7
[0107] Fluorescence Polarization (FP) Assays
[0108] Upon association of the sensor to phosphorylated substrate, the molecular rotation of the fluorophore-labeled substrate is impeded and polarization of the fluorophore-labeled substrate increased. Since FP measurements are reported as the ratio of the perpendicular and parallel emissions, it is possible to record fluorescence quench seen in the perpendicular and parallel reads simultaneously with FP during one read of a sample well.
[0109] FIG. 7 shows the results of an FP assay. Fluorescein labeled peptides were mixed at the indicated concentrations in reactions containing 20 μM ATP and sensor added. Fluorescence quench was monitored in parallel or perpendicular mode ( FIGS. 7A and 7B respectively) and the ratio recorded as fluorescence polarization ( FIG. 7C ).
Example 8
[0110] FP Assays Using Unlabeled Substrates
[0111] The impediment of the molecular rotation of the sensor upon binding to a phosphorylated species can be monitored using unlabeled substrates. In this experiment, we wanted to test the optimal loading of the phosphonate Sulforhodamine 101 chelator with different amount of zirconyl chloride.
[0112] Substrate and calibrator peptides were biotinylated LRRASLG (used at 20 μM). 10 μM of the phosphor chelator were incubated for 30 minutes at room temperature with different amounts of metal ion (50 mM). Then the samples were diluted 1:10 in sensor dilution buffer and 30 μL added to 15 μL of 100% phosphor biotin peptide or 0% phosphor biotin peptide. The delta between the samples was plotted.
[0113] FIG. 8 shows the results of an FP assay using sensor as a readout. Biotinylated phospho and non-phospho peptides were mixed with sensor that had been charged with various dilutions of metal ion. Unlabeled phosphorylated substrate (1 μM) was added to Sensors that were associated to various amounts of Zirconyl chloride (x-axis). The change in fluorescence polarization of the 100 μM Sulforhodamine 101—Zirconyl sensor upon binding to phosphorylated substrate was measured using TAMRA polarization settings. The increase in polarization was determined as the delta between milli pi (mP) of sensor in the absence of metal ion or in the presence of various concentrations of metal ion.
Example 9
[0114] Use of Fluorescence Donors to Excite Other Fluorophores
[0115] Energy transfer from the sensor to another fluorescent species results in an emission signal of the acceptor fluorophore upon excitation of the sensor. This results in a “turn on” assay and enables ratiometric monitoring.
[0116] A bimolecular type sensor (sulforhodamine 101-phosphonate chelator ( FIG. 11 )) associated with zirconium ion was used. The complex can associate with phosphates present on streptavidin. The streptavidin was also labeled with DyLight647. When an excitation wavelength of 540 nm is used, the sulforhodamine 101 chelator emits at 590 nm. Since the sensor is associated with the streptavidin-Dylight, the sensor is close enough for energy to transfer from the sulforhodamine 101 to the DyLight fluor. The transferred energy excites the Dylight, which then emits at 685 nm. Transferred emission increases as a function of streptavidin-Dylight647.
[0117] FIG. 9 shows the results of an assay using the sensor to excite another fluorescent species. Various ratios of streptavidin labeled with DyLight647 were mixed with sensor and the amount of transferred emission measured in a spectral scan. The height of the peak at 685 nm increases with the amount of added streptavidin DyLight647.
Example 10
[0118] Use of Sensors to Monitor Other Enzymatic Activities
[0119] The association of sensor to a phosphorylated site can be used as a tag to monitor activities of other enzymes that are involved in post translational modification (PTM).
[0120] In situations where detecting activities of posttranslational enzymes, such as proteases is desirable, the substrate is contacted with the sample in a reaction buffer. The substrate may comprise an amino acid sequence that is specifically cleaved by a protease of interest. In addition, the substrate typically comprises a phosphorylated residue. The cleavage site of the protease may be arranged such that cleavage of the substrate will result in the portion of the substrate comprising the fluorescent label being on a separate fragment of the substrate from the portion of the substrate that comprises the phosphorylated residue. The reaction is allowed to proceed for a selected period of time. In step 2, a sensor molecule is added to the reaction mixture and incubated for a selected period of time. The sensor associates with the substrate fragments comprising the phosphoryl. Following association of the sensor (red star) to the phosphorylated substrate fragments, fluorescence quench of the substrate is monitored. The increase in observed fluorescence intensity is proportional to the increased percentage of cleavage of the substrate. Fluorescence polarization of dye-labeled substrate fragment is detected as a decrease in fluorescence polarization signal.
[0121] FIG. 10 provides a schematic of assays for detection of PTM activities using a sensor as a tag. A fluorophore-labeled substrate (circles with starburst) is altered by a post-translationally active enzyme. The addition of the modifying group to the substrate (indicated by XXX in FIG. 10 ) disrupts the ability of a protease to cleave the substrate. The substrate is labeled with a phosphate and can associate with the sensor via metal ion-phosphate interaction. In the presence of cleavage, fluorescence is unquenched, whereas in the absence of cleavage, fluorescence is quenched. Separately, the approach is useful for detecting the activities of proteases in the manner described.
Example 11
[0122] Synthesis of a Sensor of the Invention
[0123] FIG. 11 provides a schematic of a synthetic approach for making a sensor of the invention. In the embodiment shown in FIG. 11 , the sensor is comprised of a fluorescent chelator and zirconium ion provided as zirconyl chloride.
[0124] Sulforhodamine 101 is a precursor for the synthesis. Following amination, the amine group is converted to a phosphonate group using perchloric acid. The metal ion zirconyl chloride is then added and associates with the phosphonate group whilst retaining it's ability to bind to phosphates present on substrates.
Example 12
[0125] Assays Using Multiplex Format
[0126] FIG. 12 shows the results of an assay in multiplex format.
[0127] Substrates (5 μM LRRASLG) were labeled with Hilyte488, TAMRA or
[0128] Chromeo642 and combined into one well containing 5 μM cellular lysates. Sensor was added (30 μL diluted 1:20 in sensor dilution buffer, final concentration 1.25 mM) and fluorescence quench monitored using an excitation wavelength of 490 nm, 540 nm and 642 nm with 520 nm, 590 nm and 680 nm emission for Hilyte488, BODIPY-TAMRA and Chromeo642, respectively
Example 13
[0129] Multiplex Phosphatase Assays
[0130] FIG. 13 shows the results from a multiplexed readout of phosphatase activity. Phosphopeptides FAM-LRRA(pS)LG, Chromo 642 -GLRRA(pS)LG and the phosphatase specific TAMRA-GLGF(pY)MAYG were combined into one well and the corresponding non-phosphorylated peptides in another. Following addition of protein tyrosine phosphatase (PTP-1B) sensor was added (30 μL diluted 1:20 in sensor dilution buffer) and fluorescence quench monitored using an excitation wavelength of 490 nm, 540 nm and 642 nm with 520 nm, 590 nm and 680 nm emission for Hilyte 488 , BODIPY-TAMRA and Chromeo642, respectively. The % recovery was calculated based on non phospho controls.
Example 14
[0131] Increased Assay Sensitivity Using Phosphonate Fluors
[0132] FIG. 14 shows the increased sensitivity of assays based on intramolecular quenching using phosphonate fluors versus intermolecular quenching. PKA was reacted in assay buffer (10 mM TRIS, 10 mM MgCl 2 , 0.01% TritonX-100, pH 7.2) in the presence of 25 μM ATP and substrate (3 μM Chromeo642-GLRRASLG or TAMRA-LRRASLG. Sensor was added (30 μM diluted 1:20 in sensor dilution buffer) and fluorescence quench monitored using an excitation wavelength of 540 nm or 642 nm with 590 nm and 680 nm emission for TAMRA and Chromeo642, respectively. Curve fit was performed using sigmoidal dose response (GraphPad PRISM). The sensitivity of PKA detection using the substrate with phosphonated Chromeo fluor ius 35 times higher than when using TAMRA labeled substrate.
Example 15
[0133] Detection of Enzymatic Activity in Mouse Brain Lysates
[0134] The performance of a sensor of the invention for detection of kinase activities in whole mouse brain homogenates was tested using Protein Kinase A (PKA) as an exemplary kinase. A lysis buffer was formulated that effectively terminates protease and phosphatase activities without interfering with the fluorescent signal. With this buffer, lysate was prepared from a total mouse brain and combined with assay buffer, ATP and peptides with sequences specific for PKA (LRRASLG). Peptides were labeled with either TAMRA or Chromeo642, with the expectation that the Chromeo642-labeled peptides would result in higher detection sensitivity.
[0135] After incubation at room temperature in 96-well plates, sensor was added and fluorescence quench monitored. Endogenous kemptide phosphorylation was detected in lysates that were incubated with Chromeo642-labeled peptide but not with TAMRA-labeled peptide. It was determined that the majority of kemptide phosphorylation was derived by PKA since the inhibition obtained using the generic serine kinase inhibitor, staurosporine, was almost identical to the inhibition achieved using a PKA-specific competitive substrate inhibitor. Irrelevant inhibitors of Phosphatidylinositol Kinases did not inhibit Kemptide phosphorylation. The sensitivity of the assay was determined to be in the femtomole to attomole range.
[0136] Preparation of Mouse Brain Homogenate
[0137] Frozen mouse brain (1.5 g) was pulverized using mortar and pestle. Four milliliters of ice cold lysis buffer (Cytobuster Protein Extraction Reagent, EMD Biosciences, San Diego, Calif.) containing a commercially available protease inhibitor cocktail and phosphatase inhibitor cocktails and 1.3 mM DTT. The inhibitor cocktails used were used were 0.12% phosphatase cocktail inhibitor 2 (Sigma Aldrich), 0.5% phosphatase inhibitor cocktail 1 (Sigma Aldrich), ½ complete mini-tablet (Roche), in a buffer containing 20 mM Imidazole; 11.5 mM sodium molybdate and 40 mM sodium tartate. The mixture was transferred to a dounce homogenizer and processed until the preparation appeared homogenous. An additional twelve milliliters of cold lysis buffer was added to the preparation and incubated on a shaker at room temperature for 3 hours. The sample was then centrifuged in a Heraeus Biofuge 13R centrifuge at 13,000 rpm for 20 min after which the supernatant was recovered. Protein concentration was determined by Bichinonic assay (BCA; Pierce) following the manufacturer's recommendations. Concentrated stock aliquots of 1.6 mL and more dilute aliquots of 100 μL were frozen at −20° C. and used fresh for experiments.
[0138] Assay
[0139] Kemptide (3 μM; LRRASLG) labeled with TAMRA or Chromeo642 was combined with ATP and inhibitor (either staurosporine or PKA inhibitor 5-24, EMD Biosciences, San Diego, Cafif.) in a total reaction volume of 25 μL in wells of a black 96-well plate, which contained 25 μl of lysate. As shown in FIG. 15 , the lysate was spiked with varying amounts of PKA and assays were run±PKA and ±ATP. At the end of the incubation period, reactions were terminated by addition of 200 μL of sensor (0.75 mM or 1 mM) diluted in sensor Dilution Buffer (1M NaCl, 10 mM MES pH 6.5; 0.01% Triton X100 0.05% NaN 3 ). For monitoring of TAMRA fluorescence, excitation and emission wavelengths of 540 nm and 580 nm were used and for monitoring of Chromeo642 fluorescence, wavelengths of 630 nm and 660 nm.
[0140] Lysis Buffer Optimization
[0141] Phosphorylated and non-phosphorylated TAMRA-labeled peptides were used in the presence of each single lysis buffer component to evaluate possible inhibition with sensor. The Signal to Background (S/B) was determined for each experiment and Sodium orthovanadate found to reduce the S/B substantially (not shown). Therefore, lysis buffer without sodium orthovanadate was prepared using single components. No fluorescence recovery of phosphorylated substrate was observed after 1 hour of incubation at room temperature, indicating effective inhibition of endogenous protease and/or phosphatase activities.
[0142] Sensor Optimization
[0143] Using kemptide, the concentration of sensor that produced the highest S/B in the presence of 50 μM lysate was determined to be between 0.75 mM-1 mM.
[0144] Progress Curves
[0145] ATP (25 μM) and either 3 μM Chromeo642-labeled Kemptide or TAMRA-labeled Kemptide were added to 25 μg lysate at various time points. At the end of the 60-minute progress time point reactions were terminated by addition of 1 mM zirconyl chloride as sensor. In order to estimate the amount of endogenous enzyme activities, 6 nM or 3 nM recombinant PKA was added to wells containing TAMRA labeled kemptide ( FIG. 15B ) and 0.5 nM PKA was added to wells containing Chromeo642-labeled kemptide ( FIG. 15A ). Following incubation for 1 hour at room temperature reactions were terminated by addition of 100 μM Zirconyl sensor. Control wells were identical to experimental wells but contained no ATP.
[0146] The results demonstrate increased sensitivity of the assay using Chromeo-labeled peptides. When 0.5 nM recombinant PKA is spiked into reactions, the reaction is completed after 10 minutes ( FIG. 15A ), whereas TAMRA-labeled kemptide requires 6 nM PKA for activity to achieve 60% activity ( FIG. 15B ). FIG. 15 is a plot of % activity relative to the no ATP control.
[0147] The progress curves demonstrate endogenous Kemptide phosphorylation in wells containing ATP and no added enzyme ( FIG. 15A , “0 nM+ATP”) with Chromeo642 labeled substrate. Following incubation for 1 hour at room temperature reactions were terminated by addition of 100 μM Zirconyl sensor. The assay accurately detects enzyme activity of the 0.5 nM spiked enzyme ( FIG. 15A ), which corresponds to a sensitivity in the femtomolar range. No endogenous activity was detected with TAMRA labeled substrate ( FIG. 15B ).
[0148] Lysate Optimization
[0149] Various concentrations of lysate were tested to determine the smallest amount of lysate that can be used to detect endogenous Chromeo642-Kemptide phosphorylation. Reactions proceeded for 1 hour at room temperature in the absence or presence of ATP ( FIG. 16A ). Following incubation for 1 hour at room temperature reactions were terminated by addition of 100 μM Zirconyl sensor. The change in relative fluorescence units (delta RFU) was determined ( FIG. 16B ). Results show that Kemptide phosphorylation can be detected in as little as 0.25 μg lysate.
[0150] ATP Optimization
[0151] It appears as if endogenous ATP present in the cell is depleted from the lysates during preparation. Therefore, ATP must be added to the reaction to initate kinase activity. To determine the optimal concentration of ATP various concentrations were reacted with Chromeo642 labeled Kemptide (3 μM) in the presence ( FIG. 17A , filled bars) or absence ( FIG. 17A , striped bars) of 15 μg lysate for 1 hour at room temperature. Reactions were terminated by addition of 100 μM Zirconyl sensor. The S/B was computed ( FIG. 17B ) and shows that a S/B of >5 can be achieved in the presence of 250 μM ATP.
[0152] Inhibition
[0153] Kemptide (LRRASLG) is a synthetic peptide substrate for cAMP-dependent protein kinase (PKA) derived from the PKA phosphorylation site in liver pyruvate kinase. The substrate is recognized by other kinases, such as members of the PKC family. To evaluate the specificity of Kemptide phosphorylation by PKA, inhibition experiments were performed simultaneously using a generic serine inhibitor, Staurosporine, and a PKA-specific substrate competitive inhibitor (PKA inhibitor 5-24). Reactions were terminated by addition of 100 μM Zirconyl sensor. Staurosporine showed minimally higher potency than the PKA specific inhibitor ( FIG. 18A ), suggesting that the majority of the Kemptide phosphorylation observed in the mouse brain lysates is derived from PKA. No inhibition was observed using irrelevant inhibitors for PI3K (LY294002 and PI3K I-2; FIG. 18B ).
[0154] Assays of the invention can be modified in various ways. For example, any source of tissue may be used to prepare a lysate for analysis. In some embodiments, lysates may be prepared from biopsy material taken from a suspected tumor, for example a lung tumor, a breast tumor etc.
[0155] In some embodiments, peptide substrates may be designed that are specific for particular kinases. Such peptides may be labeled with a suitable fluorophore, for example, labeled with Chromeo642. Peptides that are specifically phosphorylated by a protein kinase include SEQ ID NOs: 1-12.
[0156] In some embodiments, assays of the invention may be multiplex assays (i.e., may be used to simultaneously detect multiple kinase activities) For example, a first peptide substrate labeled with Chromeo642 may be specifically phosphorylated by a first protein kinase and a second peptide substrate labeled with Chromeo546 may be specifically phosphorylated by a second protein kinase. The phosphorylation state of each peptide may be determined as set out above using different excitation and emission wavelengths for each peptide.
Example 16
[0157] Detection of Phosphodiesterase (PDE) Activities.
[0158] The performance of sensor for detection of phosphodiesterase activities was tested using recombinant PDE41A1A in biochemical assays and using mouse brain homogenates. For biochemical assays, 2 μM fluorescein labeled cAMP was added to various concentrations of recombinant PDE4AIA and zirconyl chloride sensor was added (100 μM) following 1 hour of incubation at room temperature ( FIG. 19A ). The robustness of the assay was determined by measuring the Z-factor ( FIG. 19B ). Z-Factors of 0.71 with 1 nM enzyme and 0.88 with 0.25 nM enzyme were achieved. An assay with a Z factor of >0.5 is considered robust enough for high throughput screening. Monitoring of enzyme activities in kinetic mode was achieved using various concentration of enzyme and 2 μM fluorescein labeled cAMP ( FIG. 19C ). Reactions were terminated by addition of 100 μM Zirconyl sensor. PDE assays tolerate high concentrations of substrate, allowing precise determination of substrate Km ( FIG. 20 ). Reactions were terminated by addition of 100 μM Zirconyl sensor. Inhibition values for the PDE4 specific inhibitor Ro-20-1724 and for the generic inhibitor IBMX closely matched literature values ( FIG. 21A ). FIG. 21B demonstrates inhibition of PDE41A1A with various concentrations of Ro20-1724 in kinetic mode and in the presence of 100 μM Zirconyl sensor.
[0159] Assays can be performed in lysates of mouse brain, as shown in FIG. 22 , using 2 μM fluorescein labeled cAMP and 2 μg lysate and 100 μM zirconyl sensor in kinetic mode. Multiplexing can be accomplished using electron transfer quenching with zirconyl chloride sensor and 2 μM fluorescein labeled cAMP simultaneously with 2 μM TAMRA labeled cGMP in various concentration of mouse brain lysate.
[0160] The assay platform can be used to monitor activities of enzymes of various classes, and thus is a novel tool to connect different braches of signaling. As outlined in the schematic FIG. 24A , a phsphodiesterase-mediated cleavage of cAMP is inhibited by IBMX. As a result, increasing amounts of cAMP can bind to the regulatory domain of its downstream target, PKA. Upon binding, the regulatory subunits disassociate from the catalytic subunit and PKA becomes catalytically active. This relationship is experimentally demonstrated in FIG. 24B , which shows increasing phosphorylation of the PKA substrate Chromeo-GLRRASLG and decreasing activity of phosphodiesterase mediated cleavage of cAMP as a function of IBMX concentration.
[0161] While the foregoing invention has been described in some detail for purposes of clarity and understanding, it will be appreciated by one skilled in the art from a reading of this disclosure that various changes in form and detail can be made without departing from the true scope of the invention and appended claims. All patents and publications cited herein are entirely incorporated herein by reference. | The present invention relates to novel compounds which are capable as acting as fluorescent sensors or which are precursors for these and for the use of these for the assay of biological processes such as posttranslational modifications of biological molecules such as phosphorylation, de-phosphorylation, proteolytic cleavage, phosphodiesterase mediated hydrolysis of cyclic nucleotides, methylation, acetylation of proteins peptides, DNA, lipids and the detection of biomolecule interactions (e.g., protein-protein interactions). A small molecule sensor is described which can associate to phosphorylated biological targets via metal ion—phosphate association. The association event can be monitored as fluorescence quench, sensitized emission, fluorescence polarization or a combination thereof. The sensor is useful for determining enzyme | 6 |
BACKGROUND OF THE INVENTION
The subject invention is directed toward the valve art and, more particularly, to a dispensing valve assembly.
The invention is especially suited for use as a dispensing valve on bag-in-the-box or membrane type beverage containers and and will be described with particular reference thereto; however, as will become apparent, the invention is capable of broader application and could be used in many different environments for a variety of purposes.
In the commonly assigned U.S. Pat. No. 4,621,750 issued Nov. 11, 1986 for "Dispenser Valve", there is disclosed a valve intended for dispensing fluid products which generally comprises a tubular discharge nozzle or passageway having a longitudinal bore which communicates with an inlet passage through a port in its side wall. A valve element in the form of a resilient tube is located within the tubular discharge nozzle. The valve element is compressed and interference fitted within the nozzle and seals about the port. The valve element is moved between open and closed positions by a handle assembly which pivots to selectively shift the valve element away from the port to permit flow therethrough.
The noted valve is relatively inexpensive to manufacture and is highly reliable in operation. In addition, the valve is capable of undergoing an extremely high number of cycles without leaking.
One disadvantage of the noted valve is that it is somewhat difficult to assemble and disassemble. Specifically, difficulties are sometimes encountered during manufacture in properly placing and locating the resilient tube within the discharge passageway. Likewise, removal of the tube for replacement is also a problem.
A further difficulty with the prior valve is that under certain conditions it has a less than desirable rate of flow. That is, it would be preferably if the valve could accommodate a greater flow rate without requiring increasing the overall size of the valve.
Accordingly, it has been considered desirable to develop a new and improved dispensing valve assembly which would overcome the above discussed problems and others while providing improved overall functioning and results.
BRIEF SUMMARY OF THE INVENTION
In accordance with the present invention, a new and significantly improved valve apparatus is provided which is simple to manufacture and repair and which is highly reliable in operation.
More particularly, in accordance with the invention, the valve includes a first body portion having connecting means for joining the body portion to a fluid outlet. A second body portion comprising a relatively rigid, elongated member extends from the first body portion. The relatively rigid member has a lateral sidewall and terminates in a free end portion. A discharge orifice is formed in the lateral sidewall of the second body portion and a fluid passageway means extends through the first and second body portions for providing fluid communication from the fluid outlet to the discharge orifice. Mounted on the second body portion in tightly encircling relationship to sealingly overlie the discharge orifice and prevent flow therethrough is a resilient tubular member. The tubular member is under significant tension so as to tightly and sealingly engage about the discharge orifice. Associated with the valve are operating means for selectively and resiliently deflecting the tubular member away from the second body portion to permit flow through the discharge orifice.
In accordance with a more limited aspect of the invention, the valve includes a housing or shield member which is joined to the body and encloses a major portion of the resilient tubular member at a location spaced outwardly thereof. Preferably, the housing member has a length such that it extends substantially to the free end portion of the second body member.
In accordance with a more limited aspect of the invention, the second body portion and the housing member are preferably cylindrical and the discharge orifice is located closely adjacent the free end of the second body portion.
In accordance with a still further object of the invention, the tubular member includes an integral loop or tab on the exterior surface thereof which is engaged by the operating member. Preferably, the operating member and loop are located such that movement of the operating member causes the tubular member to be pulled away from the second body member in an area adjacent the discharge orifice.
In accordance with a further aspect of the invention, both the first and second portions of the body member are integrally formed from a resinous plastic material and the tubular member is molded from a suitable rubber or resilient plastic material which is capable of significant elastic elongation.
A primary advantage of the invention is that the tubular member is located on the exterior of the nozzle portion of the body in a position which facilitates installation and removal.
Yet another advantage of the invention is that the relationship between the outlet orifice and the free end of the second body portion is such that when considered in conjunction with the tubular seal member, there is little or no space in which fluid can be trapped for subsequent dripping or leakage problems.
Still other benefits and advantages of the invention will become apparent to those skilled in the art upon a reading and understanding of the following detailed specification.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention make take physical form in certain parts and arrangement of parts, preferred and alternate embodiments of which will be described in detail in the specification and illustrated in the accompanying drawings which form a part hereof, and wherein:
FIG. 1 is a side elevation of a first embodiment of dispensing valve assembly formed in accordance with the preferred embodiment of the subject invention;
FIG. 2 is a longitudinal cross-section view of the valve shown in FIG. 1;
FIG. 3 is a view taken on line 3-3 of FIG. 1;
FIG. 4 is a partial cross-sectional view similar to FIG. 2 but showing the valve in an open position;
FIG. 5 is a side elevational view (partially in section) illustrating the preferred form of the tubular valve member used in the FIG. 1 embodiment; and
FIG. 6 is a longitudinal cross-sectional view of a second embodiment of a dispensing valve assembly formed in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring more specifically to the drawings wherein the showings are for the purpose of illustrating preferred embodiments of the invention only and not for the purpose of limiting same, FIG. 1 illustrates the overall arrangement of the preferred embodiment of a dispensing valve assembly A. While the valve assembly A is, as previously mentioned, primarily designed for and intended to be used in conjunction with the disposable bag-in-the-box or membrane type fluid containers, it will be appreciated that the valve and the inventive concepts embodied therein could equally well be used in other dispensing or valve environments for handling a variety of fluids under differing conditions. More particularly, and with specific reference to FIGS. 1 and 2, the valve assembly A of the subject embodiment generally comprises a molded plastic body 10 which includes a connecting means 12. The connecting means 12 could be of many different types but as shown as including simple threaded collar or sleeve member 1 which is adapted to join the body 12 to an associated outlet nozzle of a fluid source (not shown) such as a membrane type container. The threaded sleeve 14 is retained on the body while being permitted to have free rotation thereto by a simple collar or the like 16 carried on the body assembly 10. The body 10 could have a variety of external configurations but is illustrated as comprising a first generally cylindrical body section or portion 18 which includes a central opening 20 which extends inwardly from the connecting end of the valve assembly A. Both the connecting sleeve member 14 and the valve body 10 could be formed from many different materials using different forming processes. In the subject embodiment, however, the valve is preferably injection molded from a suitable plastic such as high density polyethylene or the like.
Integrally connected with the first body portion or section 18 is a second body portion indicated generally with the reference number 22. As shown in FIG. 3, the second body portion 22 is of a generally cylindrical shape and includes a first tubular or cylindrical section 24 and a second housing or outer shield section 26. Section 26 is spaced from the central cylindrical section 24 to provide a somewhat annular shaped opening or passage 28 which extends inwardly from the lower free end of body section 22. As beset shown in FIG. 3, the outer housing section 26 encompasses the upper approximately 270° of the generally circular second body portion. As will become apparent hereafter, this gives the valve the overall appearance of a typical dispensing type outlet nozzle or the like.
Although the central cylindrical portion 24 could be solid, it preferably has an opening 30 extending inwardly from the free end. The opening 30 gives the lower end of the valve the appearance of a conventional outlet faucet, tap or nozzle and reduces the quantity of material required to form the valve. Formed within the cylindrical portion 24 is a passageway 32 which joins with the opening 20 and terminates at its lower end (see FIG. 2) in a discharge orifice 34. The passageways 20 and 32 combine to provide a flow passageway means from the connecting end means 12 to the discharge orifice 34.
Referring more particularly to FIGS. 2 and 5, a generally cylindrical tubular member 36 is positioned about the cylindrical second body portion 24. The tubular member 36 is preferably made from a soft, extremely resilient elastomer capable of undergoing significant elastic deformation withou taking a permanent set or rupturing. The material should have resistance to aging and permanent set and soft sealing qualities and memory properties stable across a relatively wide temperature range. The tubular seal member 36 is formed as shown in FIG. 5 and has an internal diameter D i which is significantly less than the external diameter D o of the cylindrical portion 24. The tubular member 36 is placed over the tubular member 24 as shown in FIG. 2 to tightly encircle the portion 24 and sealingly overlie the discharge nozzle 34. Preferably the tubular seal member 36 is under sufficient tension to allow it to seal against relatively high pressures within the passageway 32.
The tubular seal member 36 is arranged to be moved to an open or flow permitting position as shown in FIG. 4 by being deflected away from the member 24 at least in the area adjacent the free end of member 24 and surounding the passageway 32. Many different types of operating means could be used to produce the required selective deformation of the tubular sealing member 36. In the subject embodiment, however, the means used comprise an operating lever or handle assembly 40 (see FIGS. 2 and 3) which includes a pair of pivotally mounted side arm members 42 and 44 which are joined to the body assembly 10 by suitable pivot pins 46. The arms 42 and 44 are joined at their upper ends by a transversely extending handle or actuating portion 48. At their lower ends the arms 42 and 44 are connected by a transversely extending section 50 which is connected to the underside of the tubular seal member 36. This connection could take many forms, but in the subject embodiment, comprises an integral tab or loop 52 molded on the lower side of the tubular sealing sleeve 36 as best shown in FIGS. 2 and 5. Specifically, the loop 52 includes a central opening 54 which receives a pin like member 58 extending from the cross-piece 50 and being tightly received in the opening 54. As can be appreciated, forcing the handle portion 48 of the operating assembly in the direction shown by the arrow in FIG. 2 causes the tubular sealing sleeve 36 to be pivoted or pulled away from the member 24 as best shown in FIG. 4. This produces an opening of the orifice 34 and permits flow to take place as shown by the arrow 60.
As can be seen from the foregoing, the subject valve is extremely simple in construction. Installation or removal of the tubular seal member 36 is simplfied because it is externally accessible. To facilitate removal and installation the handle assembly 40 is preferably formed in a manner to permit its ready removal fromm the valve assembly, such as by lateral deflection of the arms 42, 44 off the pivot pins 46. Similarly, it is, of course, possible to make the housing or shield member 26 removable to provide further access to the seal member 36.
FIG. 6 illustrates a second embodiment of dispensing valve formed in accordance with the invention. In this embodiment like reference numerals differentiated by a prime (') suffix have been used to identify the same or similar elements. Elements so identified are to be considered as the same as the corresponding element of the FIG. 1 embodiment unless otherwise noted. More particularly, in this embodiment, passageway 32' extends from central opening 20' to an outlet or discharge orifice 34' located on the upper section of the cylindrical second body portion 24'. The tubular seal member 36' surrounds body portion 24' and sealingly overlies the discharge orifice 34'.
The operating means for pulling the tubular sealing member 36' away from the orifice 34' to permit flow to take place comprises a tab or handle portion 66. Preferably, the handle portion 66 is formed integrally with the sealing member 36', as shown.
The invention has been described with reference to preferred and alternate embodiments. Obviously, modifications and alterations will occur to others upon the reading and understanding of this specification. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof. | A dispensing valve comprises a first body portion having a connecting assembly for joining to a fluid outlet. A second body portion comprises a relatively rigid, elongated member having a lateral side wall terminating in a free end. A discharge orifice is formed in the lateral side wall of the second body portion. Mounted on the second body portion in tightly encircling relationship to sealingly overlie the discharge orifice and prevent fluid flow therethrough is a resilient tubular member. An operating handle is joined to the tubular member for selectively and resiliently deflecting the tubular member away from the discharge orifice to permit flow therethrough. | 8 |
BACKGROUND OF THE INVENTION
For the molding of electronic components, chips, molding apparatus are used wherein a so-called leadframe supporting an electronic component, such as a chip is placed into a mold wherein the mold displays recesses for receiving the parts for molding, and in addition cavities are arranged in the mold wherein measured quantities of molding material are placed and wherein by supplying heat and exerting pressure in these cavities the molding material becomes liquid, moves via channels intended for that purpose to the parts for molding and, curing there, encapsulates the leadframe. The leadframe is subsequently removed from the molding apparatus and subjected to further processing. An apparatus of this type is known for example from Patent Abstracts of Japan, vol. 4, No. 128 (M-31)(610), Sep. 9, 1980, & JP,A, 5587517 of Jul. 2, 1980.
SUMMARY OF THE INVENTION
The object of the invention is to provide a single-strip molding apparatus which combines a simple construction with a relative high production rate.
This achieved according to the invention by providing a single-strip molding apparatus comprising a mold formed by two mold halves vertically movable relative to one another and closable onto one another, means for placing a leadframe supporting an electronic component into one of the mold halves, means for carrying molding material into cavities of the mold, means for exerting pressure and supplying heat to said cavities to liquify the molding material and channels for supplying said molding material to said recesses, means for heating the mold halves, means for cleaning the mold halves and means for removing a molded product from the mold.
By combining different processes such as cleaning, which has to take place after each molding cycle, with the removal of the molded product an optimal production rate is achieved.
From U.S. Pat. No. 3,059,305 a molding apparatus is known in which a reciprocating hopper is provided that combines the function of supplying molding material and cleaning of the mold cavity. After molding the object the molding pushes the product outwardly of the mold and cleans the mold cavity. The mold press consists of two plungers pressing the molding material in the cavity.
According to a preferred embodiment the cleaning-discharge unit performs a reciprocating movement and during the outward movement the one mold half is cleaned and during the inward movement the molded product is removed and the other mold half cleaned in one operating stroke.
An optimal production rate is achieved by setting into operation the means for placing a subsequent leadframe in a mold immediately following the inward movement of the cleaning-discharge unit.
The means for exerting pressure preferably consist of at least one plunger which is driven by means of an electromotor, a screwed rod and a nut arranged on a screwed rod. Driving has taken place to date in the usual manner with hydraulic means, which however entails various drawbacks. Hydraulic driving requires cooling and is not otherwise well compatible with the clean surroundings in which the process must take place. There has further been the drawback that there was no direct proportional relation between the exerted hydraulic pressure and/or the controlled volume flow of the hydraulic oil and the displacement speed of the plunger. The pressure-raising process was difficult to control. Using the electromechanical driving a direct relation is achieved between the action of the electromotor and the displacement speed of the plunger and/or the force to be exerted by the plunger on the molding material by converting the rotation movement of the electromotor into a linear movement of the plunger rod using the nut and the screwed rod. An electromotor moreover does not pollute the surrounding area which befits the cleanliness required of the area wherein the process takes place. In addition the energy consumption of a hydraulic plunger drive is much greater than that of an electromechanical plunger drive. With hydraulic plunger driving cooling is therefore needed for the oil heated by friction losses. The noise level of an electromechanical driving is also considerably lower.
The mold halves are also preferably closed relative to one another by an angle lever system connected to one of the mold halves and driven by an electromotor and a screwed rod. The required closing force to be exerted on the mold halves is transmitted in a suitable manner by the angle level system since this exerts great force especially at the end of the stroke.
As first alternative embodiment the mold halves can be moved relative to one another using a control mechanism consisting of a pneumatic cylinder which effects the largest part of the stroke and a piston-cylinder unit having multiple pistons placed on the piston rod for providing by pneumatic means the final necessary closing force.
As second alternative embodiment the mold halves can be moved relative to one another using a control mechanism consisting of at least one pneumatic cylinder which effects the largest part of the stroke and a closed piston-diaphragm cylinder unit filled with liquid for converting pneumatic pressure into hydraulic pressure for providing the final necessary closing force.
With the apparatus according to the invention the mold halves perform a vertical movement relative to one another, the lower mold half is fixedly disposed, the upper half is movable and the means for cleaning, for placing the leadframe in the mold and for removing product out of the mold perform a horizontal movement and the means unified into a cleaning-discharge unit for cleaning and removal of the product from the one side and the means for placing the leadframe from the other side perform a reciprocating movement extending into the mold die. This provides the advantage that during the discharge movement of the finished product to the one side following on therefrom the input means can place a subsequent leadframe in the mold die.
The means for placing a leadframe are formed by a first carriage movable over guide rails while the cleaning-discharge unit is placed on a second carriage which is movable over the same guide rails.
The plunger increasing the pressure in a cavity is preferably under bias. It is hereby possible to raise the pressure to the required level despite the fact that the same quantity of molding material will not always be present in the relative cavity. The position of the plunger is therefore adapted by the bias to the volume of molding material in the relevant cavity. As alternative method a channel is arranged in one of the two mold halves which mutually connects the cavities into which the measured quantities of molding material are fed, with the object of equalising mutual volume-differences in these fed quantities of molding material.
The invention will be further elucidated with reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-3 show schematically one complete cycle of the molding apparatus according to the invention.
FIG. 4 shows a perspective view of the molding apparatus according to the invention.
FIG. 5 shows on a larger scale a detail of the lowermost part of the molding apparatus according to FIG. 4.
FIG. 6 shows a sectional view of the mold of the molding apparatus from FIGS. 4 and 5.
FIG. 7 shows a first alternative embodiment of the closing mechanism of the mold of the molding apparatus according to the invention. and
FIG. 8 shows a second alternative embodiment of the closing mechanism of the mold of the molding apparatus according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 the mold, which consists of a fixedly positioned lower half and a vertically movable upper half, is open. It is assumed that the molding has been completed during the previous cycle and that the molded product 3 is still in the mold, that is, in the lower half 1. The cleaning-discharge unit 4 consists of a discharge carriage 5 and a brushing device 6 with brushes at the top 7 and brushes at the bottom 8. After opening of the mold (FIG. 1) the cleaning-discharge carriage 4 performs a movement to the left and thereby cleans the upper half of the mold (FIG. 2). The input carriage 9 likewise moves to the left to pick up a subsequent leadframe 10 from a store (not drawn) by means of a feed belt 16.
According to FIG. 2 the cleaning-discharge unit 4 then performs the return stroke wherein the discharge carriage 5 picks up the finished molded frame 3 using schematically designated hook-shaped means 11, 12 and cleans the lower half of the mold.
Following on from the active stroke shown in FIG. 2 the input carriage 9 places the next leadframe into the mold. During the position in FIG. 1 the input carriage is thereby filled in cavities arranged for this purpose from a so-called pellet carriage 13 with pellet-shaped portions of molding material which in the position as in FIG. 3 are placed into the cavities 14 intended for this purpose in the lower half 1 of the mold. The upper half 2 of the mold subsequently moves in the downward direction indicated with an arrow and closes (not drawn) onto the lower mold half, whereupon the molding process beings. In the position drawn in FIG. 3 remnants of the molding pellets are removed from the leadframe 3 with schematically designated means 15, after which the leadframe is discharged via a belt 17.
A further more detailed description will now be given with reference to FIGS. 4 and 5.
Mounted on the frame 100 of the machine is a fixedly positioned table 101. The table 101 bears a fixed lower mold half 102. The upper mold half 103 is movable relative to the lower half 102 using pull rods 104, 105 which are connected to the upper half 103 by the respective nut connections, 106, 107. The pull rods 104, 105 are movable relative to the fixed table 101 via bearings, for example 108.
The driving of the upper half of the mold 103 takes place from an electromotor 109. Driven by means of the worm box 110 are the angle level systems 111, 112. The angle lever systems are coupled on the one side to a movable underplate 113 and on the other side to a plate 116 fixedly connected to the table 101 by means of columns 114, 115. When the electromotor rotates the underplate 113 is moved vertically, for example in the direction of the arrow P1, which movement is transmitted via the pull rods 104, 105 onto the upper mold half 103. At the end of the stroke the arms of the angle lever system 111, 112 lie practically in one line so that a very great closing force is achieved.
The input carriage 117 is movable over the guide rails 118, 119. The driving of the input carriage 117 takes place from the electromotor 120.
Leadframes are supplied from a supply cassette and are carried up over the belts 122, 123 as far as a stop 124. During the position of the input carriage outside the mold the input carriage is filled from a so-called pellet-filling carriage 125 with pellet-shaped molding material which is take from a supply reservoir 126. For a reliable take-over of pellet-shaped molding material by the input carriage 117 from the pellet transporting carriage 125 use is made in both carriages of pin-shaped guiding means 127. The mutual movements are controlled using a sensor 128.
The cleaning-discharge unit 129 is likewise movable over the rails 118, 119 between the position outside the mold die and the position inside the mold die. The unit 129 consists of a cleaning-brushing device 130 and a discharge member 131. The cleaning device 130 brushes both mold halves after use and simultaneously sucks up brushed-off remnants. Co-acting with the unit is a break-off plate 132 which subjects the finished product to an after-processing.
As can be seen in FIG. 5, the cavities 133 in the lower half 102 of the mold are each provided with a plunger 134 which (see also FIG. 6) is biased by a spring washer 135 such that the position of the plunger is adapted to the quantity of molding material in the relevant cavities 133. The plungers are driven from an electromotor which drives a screwed rod 137 via the speed control 136. A nut 138 is placed on the screwed rod so that the rotating movement is converted into a vertically directed movement of the frame 139. Fixedly coupled to the frame are the drive rods 140, 141 for the plunger bracket 142 which in turn drives the plungers. As can be seen from the section VI--VI in FIG. 5 shown on a larger scale in FIG. 6, the pellet-shaped molding material 143 is compressed during the ascending movement and transported via the channel 144 to the cavity 145 in the lower half of the mold where the chip 146 is arranged. As can be further seen in FIG. 6 a heating coil 147 is arranged for heating the lower half of the mold. The lower half of the mold is insulated by means of insulating material 148. Also visible in FIG. 6 is the protective cover 149.
In order to improve removal of the finished product a push-out pin 150 under bias of a spring 151 is arranged near the cavity 145.
The embodiment according to FIG. 7 shows another embodiment for displacement of the upper half of the mold and the generating of the required great closing force.
Pneumatic cylinders 152 and 153 displace the upper half of the mold via the movable underplate 113, as in the case of the first discussed embodiment. At the end of the stroke the slide 153 is pushed under the piston rod 154 so that a closed piston-plunger 155 is created. Via the channel compressed air is subsequently admitted from a source 156 (not drawn) which is distributed via the sub-channels, for example 157, over pistons, for example 158, arranged on the piston rod 154. As a result of the large suction surface obtained by the combination of the pistons 158 arranged parallel on the rod 154 a very great closing force is achieved with a small stroke. This is transmitted to the plate 113 and therefore to the upper half of the mold 103. It is further noted that the closing of the slide takes place by means of the plunger 160.
FIG. 8 shows an alternative embodiment of the closing mechanism of the mold of the mold apparatus according to the invention.
A discussion of those parts which correspond with the embodiment according to figure 7 is omitted.
The closing force to the mold halves is provided in this case by a piston-diaphragm cylinder unit filled with liquid. The plunger 161 is moved by the pressure of the liquid exerted on the piston 162, which is derived from the control cylinder 163. This is in contact with the cylinder space of the plunger 161 via the line 156.
Preferably a device 200 for measuring the closing force of one of the halves of the molds is with respect to the other mold half is provided in the linkage for transferring the force from the electromotor to the movable mold half. Upon receiving a predetermined value of the closing force, a control signal is generated that is applied to stop the driving electromotor. | An apparatus for molding electronic components. The single-strip molding apparatus has a mold die formed from two mold halves which are movable relative to each other and can be closed upon one another. A leadframe for the component to be molded is placed into a recess in one of the mold halves. Molding material is heated and forced under pressure into the recess containing the leadframe. After the component is molded the mold is opened and the upper half of the mold is cleaned by a combined cleaning-discharge unit. Upon the return stroke of the cleaning-discharge unit, the molded component is removed and the lower half of the mold is cleaned. | 8 |
This application is a continuation of application Ser. No. 09/521,834, filed on Mar. 9, 2000, now U.S. Pat. No. 6,491,251 B1, issued on Dec. 10, 2002, which application is incorporated herein by reference.
FIELD
This invention relates to the dispensing of web material such as toilet tissue, paper towels and the like, from rolls of web material contained within a dispenser. This invention further relates to improved rolls that contain web material for use with a dispenser, and to methods of forming such rolls. The inventive concepts will be described hereinafter primarily in relation to toilet tissue dispensers and toilet tissue rolls. It is to be realized that the inventive concepts described herein have applications to other types of web materials in addition to toilet tissue, including, but not limited to, paper towels.
BACKGROUND
There has been continuing effort over the years to provide toilet tissue dispensers that store multiple rolls of toilet tissue and sequentially dispense the rolls. One of the advantages provided by these types of dispensers is that a reserve roll (or rolls) is available as a replacement for the roll that is currently in use.
To avoid tissue waste, it is important that the roll currently in use be depleted to its fullest extent before allowing the user to access a replacement roll. Devices that attempt to achieve such a result using a variety of methods are known in the prior art, as exemplified in U.S. Pat. Nos. 3,294,329; 3,381,909; 3,387,902; 4,108,513; 4,522,346; 4,577,426; 5,310,129; 5,636,812; and 5,749,538.
There is, however, a continuing need for improved toilet tissue dispensers that inhibit access to a replacement roll until the roll currently in use is depleted.
SUMMARY
The invention provides an improved web material dispenser that is designed to dispense web material, such as toilet tissue or the like. The web material dispenser comprises a housing, with a spider rotatably mounted within the housing for rotation about an axis extending through a center of the spider. A plurality of spools are connected to the spider and project therefrom in a direction parallel to the rotation of the spider axis. The spools are rotatable with the spider along a rotational path spaced from the axis. A core stop is fixed to the housing, with the core stop crossing the rotational path of the spools to prevent rotation of the spider until the tissue has been substantially depleted or exhausted from the roll.
In addition to the web material dispenser, the invention provides an improved web material roll for use in the inventive web material dispenser described herein or in other web material dispensers, as well as a method of making the roll.
In one version as claimed, a web material roll includes first and second core sections, with the core sections being spaced apart from each other to define a gap therebetween. In addition, a web material is wound onto the core sections.
A method of forming a core for this type of web material roll comprises providing an elongate, generally cylindrical tube having a longitudinal axis; cutting the tube into a plurality of generally cylindrical sections, with each of the sections having a length approximately equal to a width of web material to be wound onto the roll; and removing a predetermined length from proximate the center of at least one of the sections to form first and second core sections, whereby the combined length of the first and second core sections is less than the width of the web material to be wound thereon.
These and various other advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages and objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying description, in which there is described a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of the web material dispenser, with the front housing portion open relative to the rear housing portion to show the interiors thereof and with the spider and core stop removed from the rear housing portion.
FIG. 2 is a front view of the rear housing portion showing the spider and core stop.
FIG. 3 is a side view of the core stop and the roll at the dispensing position, viewed generally in the direction 3 — 3 in FIG. 2 .
FIG. 4 is a view similar to FIG. 2 showing rotation of the spider upon depletion of the web material from the roll at the dispensing position.
FIG. 5 is a cross-sectional view of the core stop and core taken along line 5 — 5 in FIG. 4 .
FIG. 6 illustrates a dispenser using a second embodiment of a core stop.
FIG. 7 is a side view of the core stop and the roll at the dispensing position, viewed generally in the direction 7 — 7 in FIG. 6 .
FIG. 8 is a view similar to FIG. 6 showing rotation of the spider upon depletion of the web material from the roll at the dispensing position.
FIG. 9 is a cross-sectional view of the core stop and core taken along line 9 — 9 in FIG. 8 .
FIG. 10 illustrates a tube that is used to form the core of the web material roll.
FIGS. 11 and 12 are a side view and a perspective view, respectively, of the web material roll utilizing a core that is formed from the tube in FIG. 10 .
DETAILED DESCRIPTION
The web material rolls and the methods of making the rolls will first be described by referring to FIGS. 10-12. The web material roll and related method described herein are specifically directed to rolls of toilet tissue. However, it is to be realized that the inventive concepts could be used in relation to other types of web material rolls that have a core and a web material wound onto the core, such as paper towel rolls. In addition, the inventive web material rolls are described as being used on the inventive web material dispensers described herein. It is to be realized that the web material rolls could be used with other types of web material dispensers in addition to the dispensers described herein.
FIGS. 10-12 illustrate the toilet tissue roll and method of forming the core thereof. This roll uses what can be referred to as a “double core”. Initially, as illustrated in FIG. 10, an elongate, generally cylindrical tube 12 having a longitudinal axis A—A is provided. The tube 12 is then cut at points 14 a , 14 b , . . . 14 n to form a plurality of equal length sections 16 a , 16 b , . . . 16 n having a width approximately equal to the width of toilet tissue. A portion 18 (shown in hatched lines) proximate the center of each section 16 a-n is then removed by cutting to form core two core sections 20 a , 20 b . The combined-length of the core sections 20 a , 20 b is thus less than the width of the toilet tissue to be wound onto the core sections 20 a , 20 b . In one implementation, the portion 18 that is removed from each section 16 a-n preferably has a length l of approximately 2.0 inches, so that the combined length of the core sections 20 a , 20 b is approximately 2.0 inches shorter in length than the tissue to be wound thereon. The tube 12 can have any convenient length from which a plurality of core sections can be formed, such as a length of approximately 115.0 inches.
Once the core sections 20 a , 20 b are formed, toilet tissue 22 is wound onto the core sections 20 a , 20 b with the core sections 20 a , 20 b being spaced apart from each other, as is evident from FIGS. 11 and 12 which illustrate a subsequently formed toilet tissue roll. As is further evident from FIGS. 11 and 12, the core sections 20 a , 20 b include ends 24 a , 24 b that face each other and which are spaced apart by approximately the distance 1 thereby forming a gap 25 . The core sections 20 a , 20 b further include ends 26 a , 26 b that are even with the opposite side surfaces 28 of the tissue 22 . Thus, there is a portion of the tissue 22 approximately midway between the side surfaces 28 that is not core supported due to the gap 25 between the ends 24 a , 24 b of the core sections 20 a , 20 b . The gap 25 between the core sections 20 a , 20 b remains until such time as the tissue 22 is substantially depleted from the roll.
As will be described below, the gap 25 between the core sections 20 a , 20 b facilitates sensing that the tissue is substantially depleted or exhausted from the roll. It is to be realized that the core sections 20 a , 20 b could be formed using methods other than that described above. For instance, instead of removing a single portion at the center of each section, portions could be removed from each end of a section and the section then cut in half to thereby form the core sections.
One implementation of a web material dispenser 50 is illustrated in FIGS. 1-5. With reference to FIG. 1, the dispenser 50 includes a rear housing portion 52 and a front housing portion 54 pivotally connected to the rear housing portion 52 at the bottom ends thereof via pivots 56 . The housing portions 52 , 54 include cooperating locking structures 58 a , 58 b at the top ends thereof, by which the housing portions 52 , 54 can be locked together to form an enclosure for a plurality of rolls of toilet tissue.
The housing portions 52 , 54 are generally circular in shape, with each including a generally circular end wall 60 , 62 and a generally circular sidewall 64 , 66 . The end walls 60 , 62 and sidewalls 64 , 66 combine to form an interior space when the housing portion 54 is pivoted upward from the position shown in FIG. 1 and connected to rear housing portion 52 , via the locking structures 58 a , 58 b . When the housing portions 52 , 54 are locked together, the end walls 60 , 62 face each other and the sidewalls 64 , 66 fit together to form an enclosure. A dispensing opening 70 is formed by the sidewalls 64 , 66 at the bottoms thereof through which tissue from one of the tissue rolls is dispensed.
The end wall 60 of the housing portion 52 is further provided with a plurality of slots 72 by which the housing portion 52 can be mounted to a wall or other fixed structure using bolts, screws or other suitable fasteners.
With reference to FIGS. 2 and 4, a spider 78 is rotatably mounted on the rear housing portion 52 for rotation about a central axis B in a clockwise direction as shown by the arrows in FIGS. 2 and 4. The spider 78 is generally circular in shape and includes a central boss 80 projecting from the center thereof parallel to the rotation axis B and toward the front housing portion 54 . The boss 80 is sized to rotatably fit over a cylindrical hub 82 (best seen in FIG. 1) that projects from the end wall 60 of the rear housing portion 52 in the direction of the axis B. The boss 80 and hub 82 are preferably secured together via a snap fit connection that detachably connects the boss 80 and hub 82 together while permitting rotation of the boss 80 , and thus the spider 78 , on the hub 82 .
In addition, an x-shaped formation 90 , visible in FIGS. 1, 2 and 4 , projects from the top end of the boss 80 . Further, an actuation disk 92 , shown in dashed lines in FIG. 1, is rotatably mounted on the front housing portion 54 . The disk 92 is disposed on the exterior side of the end wall 62 whereby the disk is accessible from outside the housing 52 , 54 by a user in order to rotate the spider 78 . A plurality of circumferentially spaced fingers 94 project rearwardly from the disk 92 toward the rear housing portion 52 , with a gap between each adjacent finger 94 . The x-shaped formation 90 and the fingers 94 are sized such that they engage when the front housing portion 54 is pivoted to the closed position relative to the rear housing portion 52 , with x-shaped formation 90 disposed within the gaps between the fingers 94 . With this construction, rotation of the disk 92 causes rotation of the spider 78 . A pair of diametrically opposite fingers 94 each include a shoulder 96 formed thereon which fit over a boss 98 projecting from the interior surface of the end wall 62 so as to rotatably secure the disk 92 to the end wall 62 .
Returning to FIGS. 2 and 4, the spider 78 is shown to include a plurality of spools 100 a-d , in this instance four spools, projecting from the spider 78 parallel to the axis B, with the spools disposed adjacent to the circumference of the spider 78 . The spools 100 a-d are spaced at 90 degree intervals around the spider 78 . However, it would be possible to use a larger or lesser number of spools, depending upon the size of the tissue rolls and the needs of the consumer, in which case the spools would be spaced at intervals of 360 degrees divided by the number of spools. Each spool 100 a-d is sized to receive thereon a tissue roll 102 .
As shown in FIGS. 2 and 4, the circumference of the spider 78 is provided with a plurality of detents 104 . Preferably, there is one detent 104 for each spool 100 a-d disposed on the spider 78 . A resilient indexing finger 106 is fixed at a first end thereof to the rear housing portion 52 and the second end thereof extends toward the spider for engagement within one of the detents 104 . When the end of the finger 106 engages in a detent 104 , rotation of the spider 78 in a counterclockwise direction is prevented, and one roll 102 is held at a dispensing position while a second roll 102 is at a reserve position (see FIG. 2 ). However, rotation of the spider 78 in a clockwise direction is selectively permitted, as described below.
A core stop 110 is further fixed to the rear housing portion 52 and extends along a radial axis toward the boss 80 of the spider 78 and into the rotation path of the spools 100 a-d and rolls 102 . The rotation path of the spools 100 a-d is shown in dashed lines in FIG. 4, and includes an outer rotation path P o defined by the radially outermost point of the spools 100 a-d as the spider rotates, an inner rotation path P i defined by the radially innermost point of the spools, and a central rotation path P c defined by the central point of the spools. As used herein, rotation path is meant to include at least one of the paths P o , P c , and P i .
The core stop 110 , as best seen in FIG. 5, includes a first portion 112 extending parallel to the spools 100 a-d and a second portion 114 that extends perpendicular to the spools. The second portion 114 extends toward and crosses the outer, central and inner rotation paths of the spools 100 a-d and includes a bottom edge 116 that is spaced a distance d above the spider 78 . Further, as illustrated in FIG. 3, the second portion 114 includes a front surface 118 that is sloped toward the bottom edge 116 in the direction of rotation of the spider 78 .
With reference to FIGS. 2-5, a “double core” type of roll, such as the roll described in FIGS. 11 and 12, is loaded onto each spool 100 a-d . The rolls 102 are shown as being mounted onto the spools 100 a-d such that the core sections 20 a are above the core sections 20 b . However, the rolls 102 could be mounted such that the core sections 20 b are positioned above the core sections 20 a.
As shown in FIG. 3, the distance d r between the side surfaces 28 of the tissue 22 is greater than the distance d between the bottom edge 116 of the second portion 114 of the core stop 110 and the spider 78 . Thus, the tissue 22 will contact the second portion 114 of the core stop 110 , if a user tries to rotate the spider 78 , and thereby prevent clockwise rotation of the spider 78 . The tissue 22 will retain the core sections 20 a , 20 b in their spaced apart condition until such time as the tissue 22 has been substantially depleted or exhausted from the roll, and rotation of the spider 78 will be prevented. It is important to realize that the distance d is greater than the length of the spools 100 a-d , as evident from FIG. 5, such that, during rotation of the spider 78 , the spools can travel under the bottom edge 116 of the core stop 110 .
However, referring to FIGS. 4 and 5, once the tissue 22 has been substantially depleted or exhausted, if a user rotates the spider 78 in a clockwise direction, the angled front surface 118 will cause the core section 20 a to be forced downward toward the core section 20 b . Thus, as evident from FIG. 5, the core sections 20 a , 20 b and the spool 100 a can travel under the bottom edge 116 to permit the spider 78 to be rotated so as to bring the next reserve tissue roll into the dispensing position.
Thus, the core stop 110 acts as a means for sensing that the tissue has been exhausted from the roll currently at the dispensing position. Once the tissue has been exhausted, the spider can be manually rotated in the clockwise direction to bring the reserve roll to the dispensing position. Since the reserve roll has tissue thereon, the tissue contacts the core stop 110 and prevents further rotation of the spider until the reserve roll is itself exhausted of tissue.
FIGS. 6-9 illustrate another embodiment of a dispenser 150 . The dispenser 150 is similar to the dispenser 50 of FIGS. 1-5, except that the dispenser 150 uses a different core stop 152 . The core stop 152 in FIGS. 6-9 is configured to function with the gap 25 between the core sections 20 a , 20 b in order to sense the depletion of tissue from the roll.
With reference to FIG. 9, it is seen that the core stop 152 includes a vertical portion 154 extending parallel to the spools. A finger 156 projects from the vertical portion 154 approximately midway along the length thereof, and extends along a radial axis toward the boss 80 of the spider 78 . In this embodiment, the distal end of the finger 156 preferably extends at least past the outer rotation path P o defined by the radially outermost point of the spools 100 a-d, but no further than the central rotation path P c Preferably, the end of the finger is located adjacent the central rotation path, although the end could be located between the outer and central paths as well. Each spool 100 a-d is formed with a cut-out 158 that, when a roll 102 is mounted on each spool, is positioned adjacent the gap 25 . The cut-out 158 is defined over approximately one-half of the circumference of each spool.
The core stop 152 functions as follows. When tissue 22 in the roll 102 , the tissue 22 will contact the finger 156 and rotation of the spider 78 is prevented. The spider will be prevented from rotating as long as tissue remains on the roll. However, once the tissue 22 has been substantially depleted or exhausted, the cut-out 158 will be uncovered, and the finger 156 can then pass through the cut-out 158 in the spool 100 a to permit rotation of the spider to bring the next reserve roll to the dispensing position. Thus, in this embodiment, the core sections 20 a , 20 b remain generally spaced apart.
It is contemplated that rotation of the spider 78 could be caused by a user when a small amount of tissue remains on the roll, in which case sufficient force would need to be applied to overcome the force of the tissue that remains covering the gap 25 and the cut-out 158 . Under most circumstances, the force required to produce such a rotation would be sufficiently large so as to deter rotation until the tissue has been substantially depleted or exhausted.
It is to be realized that the dispensers 50 , 150 described herein could be utilized with tissue rolls other than those described herein and still be in accordance with the principles of the invention. Furthermore, the tissue rolls described herein could be utilized on dispensers other than those described herein and still be in accordance with the principles of the invention.
The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended. | An improved web material dispenser that is designed to dispense web material, such as toilet tissue or the like. The dispenser is able to retain a roll containing tissue at a dispensing position until the tissue has been exhausted from the roll. The dispenser senses that the tissue is exhausted from the roll, and only then permits a reserve roll to be rotated into a dispensing position. Thus, the dispenser ensures that the tissue from each roll is used up before permitting access to a reserve roll. The invention also provides a new web material roll that utilizes a “double core”, as well as a method of making the “double core”. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Priority of U.S. Provisional Patent Application Ser. No. 60/990,498, filed Nov. 27, 2007, incorporated herein by reference, is hereby claimed.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable
REFERENCE TO A “MICROFICHE APPENDIX”
Not applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The process of the present invention relates to gaining access to the production tubing to vent fluid pressure within the tubing. More particularly, the present invention relates to a hot tapping system to vent pressurized fluids that eliminates the need to remove the outer layer of casing to obtain access to the production tubing.
2. General Background of the Invention
The conventional hot tap system is designed to allow hot tapping of the outer casing. For the conventional hot tap system, the outer casing must be removed by a process known as wedding caking to proceed to the next casing string. The conventional hot tap system takes more time and equipment to complete the same job as the Multiple String Hot Tap System. With more conventional Hot Tap System, the outer casing strings must first be hot tapped to release any trapped pressure in the casing or pump heavier fluid plug into the casing overcome the pressure. Once the pressure is released or controlled, a support structure can be attached to the outer casing for removal of a small section of the outer casing. This process is known as wedding caking; because each layer of casing is removed in layers. Once the small section of outer casing has been removed, the next casing string can now be hot tapped to gain control of this casing layer. The cycle of casing removal and hot tapping is repeated until the production tubing is reached. Once the production tubing has been hot tapped and the well bore has been controlled, the damage well casing and wellhead can be removed.
A temporary wellhead is installed on the well using the remaining casing. With the temporary wellhead in place, Plug and Abandonment operation can be started. The conventional hot tapping system could take several weeks to complete all of the hot tapping and vent of casing strings and production tubing. With a temporary wellhead installed, wireline or coil tubing operation can be used to lock open the SCSSV (surface control subsurface safety) with the manufacturers lock open tools. If there is pressure below the SCSSV, a bridge plug or tubing plug can be set to plug off the wellbore.
BRIEF SUMMARY OF THE INVENTION
What is provided is a method of hot tapping into a multiple string configuration for obtaining access to the production tubing without removing outer layers of casing by providing a multiple casing string that includes at least an outer casing and an inner casing or production string; mounting a clamp assembly around the wall of the outer casing; hot tapping a small opening through the outer casing wall to capture any pressurized fluid through the opening; cutting first and second large openings through the wall of the outer casing to access the inner casing, each opening being approximately 180 degrees from the other opening; through the first opening, drilling a small hole through the wall of the inner casing to capture any pressurized fluid through the opening in the inner casing; and inserting an anvil through the second opening to contact and stabilize the wall of the inner casing to prevent the casing from moving while the casing is drilled.
The multiple string hot tap system is a hot tapping system that eliminates the need to remove the outer layers of casing to obtain access to the production tubing. The system is designed around a unique hot tap clamping system which has a 4 or 6 inch diameter bore in the center of the clamps. This bore in the center of the clamps will be used to drill an access hole in the outer casing after the casing has been hot tapped. The access holes are later used to hot tap the next casing string.
The multiple string hot tap system eliminates the need for removal of the outer layers of casing to gain access to the inner layers of casing and the production tubing. The system designed around two clamps (a front clamp and a rear clamp). The two clamps are connected together with four chains. The chains are tensioned by applying torque to the nuts on the chain connector. The tension on the chains is based on the outer casing or surface casing size, wall thickness and material properties. If the chains are tensioned too high, the casing will fall in collapse. The maximum hot tapping pressure for the assembly is controlled by the outer casing specification and the specific set up of the multiple string hot tap assembly. The maximum hot tapping pressure can be increased by adding tension chains and increasing clamp bearing area.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
FIG. 1 illustrates a cross sectional view of the hot tap assembly in the system of the present invention;
FIG. 2 illustrates a front view of the hot tap assembly of the present invention;
FIG. 3 illustrates a rear view of the hot tap assembly of the present invention;
FIG. 4 illustrates a side view of the hot tap assembly of the present invention;
FIG. 5 illustrates a front view of the hot tap assembly of the present invention with front donut removed;
FIG. 6 illustrates a cross-section view of the hot tap assembly of the present invention with access holes;
FIG. 7 illustrates a cross-section view of the hot tap assembly of the present invention modified for inner casing hot tap;
FIG. 8 illustrates the hot tap assembly with front clamp modified with larger bearing area;
FIG. 9 illustrates a side view of the modified hot tap assembly with front clamp modified with larger bearing area;
FIG. 10 illustrates a cross-section view of alternative hot tap clamp assembly of the present invention with larger access holes;
FIG. 11 illustrates a front view of alternative hot tap clamp assembly of the present invention with larger access holes;
FIG. 12 illustrates a side view of alternative hot tap clamp assembly of the present invention with larger access holes; and
FIG. 13 illustrates a side view of the chain connector with hydraulic cylinder to better control the tensile/clamping loads in the system of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
As will be seen more clearly in FIGS. 1 through 13 , the method of the present invention relates to hot tapping a damaged oil well to release any pressure within the layers of casing or pipe, without removing the outer casing string to access inner casing strings and production tubing. The novel method utilizes a multiple string hot tap system 10 , also referred to as the novel System 10 . The equipment is designed to allow hot tapping of each string of pipe in the completion without removal of the support clamps.
In the present system, as illustrated in the various FIGS. 1 through 13 , a front clamp 18 and a rear clamp 36 are connected together with four tension chains 22 . The chains 22 are tensioned by applying torque to the nuts 10 on the chain connectors 14 . The tension on the chains 22 is based on the outer casing size, wall thickness, and material properties. If the chains 22 are tensioned too high, the casing 24 will fall and collapse. This amount of tension in the chains 22 will also control the maximum pressure that the hot tap assembly 10 can operate at or drill.
With the novel System 10 , each casing string 24 is first hot tapped with a standard hot tap drill. The hot tap drill size is generally a ½ to ¾ inch diameter. After each casing string has been drilled, access holes 25 are bored. The access holes provide a way to extend the hot tap seal saddle 32 to the next casing string 26 or the production tubing 28 . The access holes 25 are generally 6 inches in diameter for casing sizes larger than 9 inches in diameter. For casing size smaller than 9 inches in diameter, the access hole can be as small as 3 inches in diameter. The process is repeated for each inner casing string until the production tubing is reached without removing each casing string.
The novel System or method, as illustrated fully in the figures, and more completely in FIG. 7 , is designed around two cramps (a front clamp 18 and rear clamp 36 ) as shown above in the drawing figures of the hot tap assembly 10 . The key to the system is the larger access bores 25 in the two clamps 18 , 36 which provide access to inner casing string 26 and production tubing 28 . The major components of the novel System 10 would comprise a front clamp 18 with large access bore 25 ; rear clamp 36 with large access bore 25 ; a front donut 30 with replaceable hot tap seal saddle 32 ; a rear donut 38 with adjustable rear support anvil 40 ; and an extension 44 for hot tap seal saddle 32 positioning.
A critical feature of the multiple string hot tap system 10 includes a provision to allow the stabilization or gripping the inner string 26 or pipe 28 for hot tap drilling. Through a second access hole 25 , the rear support anvil 40 is installed 180° from the hot tap seal saddle 32 . The casing/pipe 26 is firmly held in place. This eliminates the need to force to one side of the outer pipe 24 and insure that the inner pipe 26 will not move during the hot tap operations. It also prevents the pipe 26 that is being hot tap grabbing the drill and failing in buckling due to bending loads.
The multiple string hot tap system 10 shows the use of standard hot tap drilling equipment. The donut insert 30 which contains the hot seal saddle mechanism 32 has been designed to allow the uses of extensions 44 to make up the addition distance to the next pipe. As stated earlier, the multiple string hot tap system 10 also provides a rear support anvil 40 for stabilization the inner string to be hot tapped. The rear support anvil 40 has been designed to allow position adjustment by screwing the anvil 40 in or out of the rear donut insert 38 . The multiple string hot tap system has a wider clamp to provide more support and bearing area. The increase bearing area provides higher operating pressure. The wider clamp can provide more resistant to bending load that are created by the hot tap drilling subassembly.
The present novel System 10 is connected using a combination of roller chains 22 and chain connectors 14 . The chains 22 are tensioned by applying torque to the nuts 12 on the end of the chain connector 14 . The condition of a coating of Teflon (a registered Trademark of Dupont Corp.) on the chain connector threads and the nuts 12 will control the actual tension in the chain 22 . On chain connectors 14 and nuts 12 , with new Teflon coating, the coefficient of friction is low about 0.15 to 0.05. On chain connectors 14 and nuts 12 with worn Teflon coatings, the coefficient of friction is higher about 0.2 to 15. As the coefficient of friction rises, the tensile load for a specific torque falls. In the present hot tap system, the specified setting torque is about 50 ft-lbs to 105 ft-lbs to produce 5000 lbs of clamping load in the chain. If a hydraulic cylinder 50 , of the type illustrated in FIG. 13 was added to the chain connectors 14 , the clamping load can be controlled by applying especial hydraulic pressure. The modified chain connectors 14 would replace each one of the four standard chain connectors 14 and nuts 12 . This would eliminate the problems of accurately applying clamping loads. The clamping loads would be uniformly applied to each of the four chain in the hot tap clamp assembly.
As illustrated in the FIGS. 1 through 13 , to carry out the method in the multiple string hot tap system 10 of the present invention, the first each casing string 24 is first hot tapped with a standard drill. The standard hot tap drill size is generally ½ to ¾ inch in diameter. Next, the multiple string hot tap clamp assembly 10 is installed on the outer casing 24 without the front donut 30 and the rear donut 38 in place. In the preferred embodiment, the centerline of the front clamp 18 and the rear clamp 36 should be aligned to insure that correct support on future operations. The chains 22 should be tensed only enough to hold the clamp assembly 10 in place. There is next provided a chain tensioning nut 12 which should be torqued to the value specified preferably by the engineer in charge of the plug and abandon operation. The torque value is based on the casing specification, hot tap pressure, and condition of the component of the hot tap assembly components. Next, the rear donut 38 with the rear support anvil 40 is installed. The position of the rear support anvil 40 should be adjusted to insure that there is a minimum gap of 0.060 inch between the rear donut 38 and the rear clamp 36 when the retainer bolts 12 are installed. The retainer bolts 12 can be replaced with 4 swing bolts and nuts. The swing bolts 12 are then pinned to the rear clamp 36 . In the next step, the front donut 30 with the hot tap seal saddle 32 is installed. The position of the hot-tap seal saddle 32 should be adjusted to insure that the there is a minimum gap of 0.060 inch between the front donut 30 and the front clamp 18 when the retainer bolts 12 are installed. The retainer bolts 12 may be replaced with 4 swing bolts and nuts. The swing bolts are pinned to front clamp. Again, the front retainer bolts 12 should be torqued to the value specified by the engineer in charge of the plug and abandon operation. The torque value is based on the hot tap, pre-charge pressure that is required. The pre-charge pressure is usually set at a higher than the casing. The pressure provides an indicator when the hot tap drill breaks through the easing wall by dropping.
Next, the hot tap drilling sub assembly 10 is attached to the front donut 30 and the hot tap saddle 32 as illustrated. The hot tap drilling subassembly would include the hydraulic drill or manual drill with a drill bit; the pressure gauge to monitor hot tap drill pre-charge pressure; the pressure pre-charge control valve; the hot tap vent valve; and the union.
The hot tap drilling subassembly should be pressured up to the pre-charge value that was specified by the engineer in charge of the plug and abandon operation. The casing or pipe is drilled with ½ to ¾ inch diameter bit when the bit breaks through the pipe wall, the pre-charge pressure will drop to a casing or pipe internal pressure. The casing or pipe internal pressure is vented and the hot tap drilling sub assembly 10 is removed. Next, the front donut 30 with the hot tap saddle 32 is removed. The rear donut 38 with the hot tap rear support anvil 40 is removed. The rail system, which is used to support and position the large diameter drill (4 inch to 6 inch in diameter) or hole saw, is then installed on the outer casing 24 below the multiple string hot tap clamp assembly 10 . If the multiple string hot tap clamp assembly 10 has to be moved or rotated to provide better support during hot tapping of an inner casing string 26 , the rail system can also be used as a support while the clamp is repositioned.
Next, a probe is then run into hot tap hole, and the location of the next inner casing string or production tubing 26 is determined. If the inner casing or pipe 26 is not located on the center line the hot tap clamps 18 , 36 , the hot tap clamps must be repositioned to insure that the next string is located In the center tine of the hot tap clamps. Two access holes 25 are drilled in the outer casing 24 . The first access hole 25 is drilled through the clamp 18 . The second access hole 25 is drilled through the rear clamp 36 . The access holes 25 will allow the hot tap saddle 32 to be installed on the inner casing 26 and the rear support anvil 40 to be installed. Before the rear donut 38 is installed, the rear support anvil 40 must be adjusted. When the rear donut 38 is installed and bolted in the rear hot tap clamp 36 , the flange on the rear donut 38 should have an offset gap with the rear clamp 36 . The rear donut 38 is now installed.
Before the front donut 30 is installed, the hot tap seal saddle 32 must match the casing diameter or pipe diameter. The position of the hot tap saddle 32 is adjusted by inserting the hot tap seal saddle extensions 44 . When the front donut 30 is installed and bolted in the front hot tap clamp 18 , the flange on the front donut 30 should have an offset gap with the front clamp 18 . Next, the front donut 30 is installed. The front donut 30 retaining bolts or nuts 12 should be made up to the torque value that is specified by the engineer in charge of the plug and abandon operation. The torque value is based on the hot tap pre-charge pressure.
The hot tap drilling sub assembly 10 is attached to the front donut 30 and the hot tap saddle 32 . The hot tap drilling subassembly would include the hydraulic drill or manual drill with a drill bit; the pressure gauge to monitor hot tap drill pre-charge pressure; the pressure pre-charge control valve; the hot tap vent valve; and the union. The hot tap drilling subassembly should be pressured up to the pre-charge value that was specified by the engineer in charge of the plug and abandon operation. The casing or pipe is drilled with a ½ to a ¾ inch diameter bit. When the bit breaks through the pipe wall, the pre-charge pressure will drop to a casing or pipe internal pressure. The casing or pipe internal pressure is vented.
Following the venting of the internal pressure in the casing or pipe, as described above, the process is repeated for each addition inner casing layer and production tubing in the well has been drilled and the pressure vented or brought under control. For each casing layer, the multiple string hot tap seal saddle 32 must be changed to match the casing or tubing diameter. In addition, seal saddle extensions 44 must be added to compensate for the added distance from the multiple string hot tap clamp assembly 10 .
FIGS. 8 through 10 illustrate front, side and overall views respectively of the multiple string hot tap system 10 having a front clamp 18 designed to provide a larger bearing area 19 , and for providing larger access holes 25 in the casing or pipe. The claim 18 is held in place by a series of four tension chains 22 secured to nuts 12 .
FIGS. 11 and 12 illustrate front and side views respectively of yet another modified manner in which to secure the front and rear 18 , 36 onto the wall of the casing 24 so as to provide a more stable means to hot tap the casing 24 , and drill the larger access bores 25 in order to have access to the next size casing or tubing 26 and production strings 28 .
As referenced earlier, FIG. 13 illustrates the use of a hydraulic cylinder 50 that would be engaged to the chain connectors 14 , so that the clamping load can be controlled by applying especial hydraulic pressure. The modified chain connectors 14 would replace each one of the four standard chain connectors 14 and nuts 12 . This would eliminate the problems of accurately applying clamping loads. The clamping loads would be uniformly applied to each of the four chain in the hot tap clamp assembly.
The following is a list of parts and materials suitable for use in the present invention.
PARTS LIST
Part Number
Description
10
multiple string hot tap system
12
chain tensioning nut
14
chain connector
16
washer
18
front clamp
19
larger bearing area
20
anvil
22
tension chain
24
surface casing
25
access bores
26
production casing
28
production tubing
30
front donut
32
hot tap seal saddle
34
Teflon seal ring
36
rear clamp
38
rear donut
40
rear support anvil
44
extension
50
hydraulic cylinder
All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. All materials used or intended to be used in a human being are biocompatible, unless indicated otherwise.
The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims. | A method of hot tapping into a multiple string configuration for obtaining access to the production tubing without removing outer layers of casing by providing a multiple casing string that includes at least an outer casing and an inner casing or production string; mounting a clamp assembly around the wall of the outer casing; hot tapping a small opening through the outer casing wall to capture any pressurized fluid through the opening; cutting first and second large openings through the wall of the outer casing to access the inner casing, each opening being approximately 180 degrees from the other opening; through the first opening, drilling a small hole through the wall of the inner casing to capture any pressurized fluid through the opening in the inner casing; and inserting an anvil through the second opening to contact and stabilize the wall of the inner casing to prevent the casing from moving while the casing is drilled. | 8 |
BACKGROUND OF THE INVENTION
This invention is concerned with transients in optical fibre amplifiers.
In an optical transmission system containing one or more optically pumped optical amplifiers in its transmission path from optical transmitter to optical receiver, the occurrence of transients in such amplifiers, such as transients in the power level of the input data signal, can produce artifacts that appears as bit errors at the receiver.
A signal with too high an optical power is subject to non-linear effects in an optical fibre transmission path, such as Self-Phase-Modulation, that can seriously degrade the signal. This causes bit errors or loss of frame in the signal. These non-linear effects are especially severe at bit rates at and above 10 Gbit/s. The onset of the non-linear degradations can be quite sharp, so that only one or two dB of increase in power level can push a signal from optimum performance to a failed state. Conversely, a signal with too low an optical power is subject to noise degradations after suffering further attenuation in the transmission path.
Transients in the power of an optical signal can move that signal away from its optimum power level towards too high or too low a power level. Power margins must be allocated in the design of the transmission system so that, during a worst case transient, in combination with other worst case conditions, the bit error rate remains within specification. In setting the margin, making allowance for these effects of transients reduces the performance that would otherwise be available, performance that could for instance otherwise be used for increasing amplifier spacing.
Even within an appropriate power range, power transients can cause bit errors. These are liable to occur for instance when the transient is faster than the automatic gain control in an amplifier at the receiver, thereby causing a momentary overload of the receive electronics. The consequential distortion produced by such overload can produce bit errors. Moreover, during a transient, the electrical signal, or eye, at the 0,1 decision circuit will be larger, or smaller, than anticipated. This places the decision threshold at the wrong location in the eye, which causes errors.
A further undesirable feature of amplitude transients is that they can produce phase transients in clock recovery circuits and so contribute to jitter, which in turn can increase bit error rate.
Erbium doped fibre amplifiers can cause amplitude transients when used for simultaneously amplifying several wavelengths. Consider the simple example of such an amplifier amplifying two wavelengths. If one wavelength is removed while the amplifier pump is held constant, then the output power at the other wavelength will increase by 3 dB. The speed of this transient is determined by the pump power and by the response of the erbium doped fibre, and is measured in microseconds.
Ways in which the gain of optical amplifiers can be controlled are well known, and examples include U.S. Pat. Nos. 5,274,496 and 5,247,529.
European Patent Application EP 0 828 357 discloses, in respect of an amplifier that is amplifying signals in different signal bands, controlling the pump power in a manner that prevents the output power in any one of these signal bands from exceeding a given threshold. This will operate to remove long-term symptoms of a change in power level, but is generally too slow to suppress the onward transmission of micro-second or milli-second transients.
The onward transmission of transients can be suppressed by providing an optical amplifier with positive feedback to cause it to lase at some wavelength not being used for signal transmission. This clamps the gain of the optical amplifier at the lasing wavelength, and therefore also clamps the gain at all other wavelengths in the gain spectrum. However such an approach requires the provision of significant extra pump power, and this is an undesirable expense. Additionally there is the disadvantage that the gain clamping provides specific values of gain at the signal wavelengths, and these values may not match the needs at that specific amplifier.
At the 22 nd European Conference on Optical Communications--ECOC '96, Oslo, in a paper (TuD. 1.3) given by R E Tench entitled, `WDM optical amplifiers--Design and Applications`, fast electronic gain control in a two-stage amplifier was described for combating gain shifts resulting from the adding and dropping of signal channels. At the same conference, in a paper (TuD.2.2) given by K Aide et al entitled, `Bi-directional Repeatered Transmission over 400 Km using Gain Stabilized Linear Repeaters`, and also in U.S. Pat. No. 5,475,529, there is described using the level of Amplified Spontaneous Emission (ASE) radiated laterally from the erbium fibre to drive a gain control circuit. In U.S. Pat. No. 5,506,724 there is described a similar approach, but in which it is the longitudinal ASE directed out of the amplifier input that is employed for gain regulation.
The response of an erbium doped amplifier has a pole that moves about the region of 300 Hz to 1 kHz, depending upon the input, output, and pump powers. These powers vary with the specific system application. For a stable control system with a bandwidth in the region of this pole, a zero must be closely matched to the pole. Because the location of the pole varies, especially during an optical transient, a static zero will not closely match the pole. If the bandwidth of the control loop is kept less than the region of this pole then the loop will not respond to fast transients. Classic linear adaptive control methods such as Kalman filtering are not fast enough because the pole moves rapidly during the transient, rather than drifting relatively slowly.
If the bandwidth of the loop is made very large, stability can be obtained, for example by using the inherent pole as the only pole in the loop. This fast loop will respond quickly to transients. However, such a wide bandwidth loop will react strongly to noise or artifacts in the measurement of the gain. Such an artefact can be created by the pattern variation in the data carried by the input signals when passed through the high-pass filtering effect of the optical amplifier.
European Patent Application EP 0 849 893 discloses an approach to the solution of the problem of transients that are liable to occur as the result of switching in or dropping out of one or more wavelength multiplexed signal channels being amplifier by an amplifier. The occurrence of these transients is suppressed by arranging for the power levels in channels being brought into service to be slowly faded in, and similarly for those in channels being taken out of service to be slowly faded out. An optical system can be managed so that all channel additions are predicted, thereby enabling appropriate fade-in provision to be made. The same is of course intrinsically not true in respect of any sudden unpredicted failure of a channel. The disclosure does however describe how to add power in a dummy signal wave length to compensate for such a drop. However that approach is relatively expensive, and uses a potentially valuable portion of the gain spectrum for the dummy signal wavelength which otherwise could have been used for real signal traffic.
Thus there is not a really efficient method known for compensation of sudden power drops where that method allows an optical amplifier to function stably in a realistic range of system applications, and the amplifier does not react excessively to small perturbations.
SUMMARY OF THE INVENTION
An object of the invention is to provide an optical waveguide amplifier that avoids some of the problems of prior art gain control methods in respect of sudden transients in optical power levels being handled by the amplifier.
This is achieved by regulating the gain of such an amplifier using a non-linear control system whose non-linearity of operation is provided at least in part by the enabling/disabling of a portion of the control system by the operation of a transient magnitude threshold sensor.
The control system may include a feed-forward portion that is enable/disabled by the threshold sensor; it may include a feedback portion that is enabled/disabled by the threshold sensor. The control system may include a control loop gain adjustment portion that is enabled/disabled by the threshold sensor.
Other features and advantages of the invention will be readily apparent from the following description of preferred embodiments of the invention, the drawings and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a generalised diagram of a wavelength multiplexed optical transmission system incorporating optical amplifiers in its transmission path,
FIG. 2 is a slightly more detailed diagram of one of the amplifiers of FIG. 1,
FIG. 3 is a schematic diagram of a circuitry operating to provide non-linear control of the gain of the amplifiers of FIG. 2 using feed-forward gain control,
FIG. 4 is a slightly more detailed schematic diagram of the functional components of the feed-forward circuitry of FIG. 3,
FIGS. 5, 6 and 7 depict in further schematic detail the functional details of components depicted in FIG. 4,
FIG. 8 is a schematic diagram of circuitry operating to provide non-linear control of the gain of the amplifier of FIG. 2 using switching of the bandwidth of a control loop regulating the operation of an optical pump pumping the amplifier,
FIG. 9 is a schematic diagram illustrating how the feed-forward gain control of FIG. 2 may be adapted for use in a transmission system employing bidirectional optical amplifiers, and
FIG. 10 is a schematic diagram of circuitry operating to provide non-linear control of the gain of the amplifier of FIG. 2 involving feedback control switched between two feedback control loops possessing different control properties.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
A schematic of a WDM optical transmission system is depicted in FIG. 1. At the transmitter end of this system, the data modulation outputs of a number of optical sources 11 are combined in some form of wavelength multiplexing device 12, and are launched into a transmission path 13, connecting the transmitter end, of the system to its receiver end. At the receiver end, the wavelength multiplexed data modulated signals are demultiplexed in some form of demultiplexer 14 so that they can be separately detected by detectors 15. At spaced intervals along the transmission path 13 are located optically pumped optical waveguide optical amplifiers 16. A slightly more detailed schematic of one of the amplifier 16 of FIG. 1 is depicted in FIG. 2. In FIG. 2 the gain medium of the amplifier is schematically depicted at 20, and its optical pump at 21. Regulation of the operation of the pump 21 is performed under the control of an input signal taken from an optical tap 22 which taps a specific fraction of the optical signal power output delivered by the gain medium 20. Additional control may be provided by a further input signal taken from a further optical tap 23 which taps a specific fraction of the optical signal power delivered to the gain medium 20.
Attention is now turned to an example of non-linear control of the gain of an optical amplifier by non-linear switched regulation of the drive current applied for the optical pumping of that amplifier. In this example a conventional control loop system provides primary regulation of the drive current in response to a control signal input representative of the optical signal power received from amplification by the amplifier. Operation of this control loop is supplemented by a switched feed-forward pathway which operates to compensate for the effects of sudden significant negative transients in the level of received optical signal power. The components of the drive current regulation system are schematically depicted in FIG. 3. In this Figure the components of a conventional control loop system are depicted within the broken line rectangle 30. This Figure, and succeeding Figures, show in schematic form functional features which can be implemented in practice by operation of a conventional microprocessor. The gain control system 30 of FIG. 3 receives an input P in that is derived from the output taken by tap 23, and so is representative of the optical signal power received for amplification by the amplifier.
The gain control system similarly receives an input P out that is derived from the output taken from tap 22, and so is representative of the optical signal power output of the amplifier. These two signals are fed to a ratio meter 31 to provide an output representative of the instantaneous optical gain of the optical amplifier 16. This value is fed to an electrical amplifier 32 and on to an integrator 33. The output of the integrator 33 regulates the optical power output of the pump. In the case of a laser diode pump, the regulation is applied as a regulation of the pump laser diode drive current I pump . The specific mean value of optical gain provided by the optical amplifier can be set to a specific value by an input shown as being applied to a summer 34 that is inserted between the ratio meter 31 and the electrical amplifier 32. The input to this summer from the ratio meter has been afforded a minus sign because, for stability of operation, the feedback control must operate in such a way that an increase in the measured value of instantaneous gain should operate to produce a reduction in the magnitude of the pump laser diode drive current I pump . Additional to the components of a conventional gain control system 30, the control system contains a feed-forward block 35 that processes a signal taken from the input P in to provide a signal applied to a multiplier 36 inserted in the output from the system 30.
The basic functional components of the feed-forward block 35 are depicted in FIG. 4, and comprise a transient relative magnitude indicator 40, a threshold detector 41, a fader 43 and an offset control device 44. The transient relative magnitude indicator compares the instantaneous value of P in with a mean (time-averaged) value X av to provide an output Y. Only when the value of Y drops beneath a certain threshold, i.e. only in the presence of a negative transient of sufficient magnitude, does the threshold detector 41 enable the fader 43 to transmit this input Y as output Z to the input of the offset control device 44. This offset control 44 provides an offset value, Δ, for adding to the output of the fader to enable compensation, for instance compensation for the proportion of amplified spontaneous emission (ASE) expected to be present in the output of the optical amplifier. This offset value, Δ, can be constant, or advantageously is actively set by the microprocessor from a direct measurement of the ASE actually being generated by the optical amplifier. At the termination of a transient that exceeds the threshold, the threshold detector 41 switches off the feed-forward function of the fader 43. When this happens, the fader operates to cause the value of Z output by it to rise in a controlled way asymptotically towards a fixed value V o . The time constant of this rate of rise is matched with the time constant of the control system 30. The connection from the threshold detector 41 to the control input of the fader 43 has been depicted as being by way of an OR gate 42 function provided for enabling the microprocessor to override the control of the fader exercised by the threshold detector. This overriding may be required for instance during power-up or changing the input transimpedance.
An example of a functional way in which the transient relative magnitude indicator 40 can be implemented is depicted in FIG. 5. An input taken from P in is passed through an isolation buffer 50, and then through a low-pass filter which controls the slew rate of this feed-forward system. For a particular system this slew rate value is chosen as a compromise between noise filtering and deglitching on the one hand, and response speed and degree of suppression on the other hand. The output from this low pass filter 51 has a value X inst related to the instantaneous value of the optical power input P in to the amplifier. This value X inst is applied to a second low-pass filter 52 which has a much longer time constant (typically about 20 ms) in order to produce a time-averaged value X av . The time constant of low-pass filter 52 is designed to match that of the amplifier control loop 30. It can be a fixed value, but advantageously the microprocessor is arranged to make the time constant of the filter 52 dynamically track that of the control loop 30 (or that of the control loop dynamically track that of the filter 52). A signal proportional to the ratio of X inst to X av is produced by a divide circuit represented by a multiplier 53 and a differential amplifier 54. The multiplier 53 receives inputs from the low pass filter 52 and from the output of the differential amplifier 54, and provides an output applied to one input of the amplifier 54. The other input to amplifier 54 is taken from the output of the low-pass filter 51. Accordingly the voltage value at the output of amplifier 54 is Y, where Y=V o (X inst /X av ).
FIG. 6 depicts the functional structure of the fader 43 and offset control device 44 of FIG. 4. In respect of the fader 43, the output Y of the transient relative magnitude indicator 40 (of FIG. 4) is fed to a switch 60 operated by the OR gate 42. In the presence of an output from the OR gate 22, the switch 60 forwards the output to a pair of diodes 61 which serve to clamp the value of that output between 0 and V o . The removal of an output from the OR gate 22 operates to activate the switch 60 so as to isolate its output from its input. At this juncture the pre-existing voltage, lying between 0 and V o , appearing on capacitor C discharges through resistor R. Accordingly the output Z of the fader is raised asymptotically to the value V o with a time constant determined by the values R and C. In the offset control device the output value Z is offset by a value Δ by means of amplifier 62, and the resultant is clamped to a value lying between 0 and V o by a further pair of diodes 63 before being applied to the multiplier 35.
FIG. 7 depicts the functional structure of the threshold detector 41. An input Y is taken from the output of the transient relative magnitude indicator 40 and is passed via a low-pass filter 70 to a differential amplifier 71 where it is compared with an input V o -A, where A is the value of the activation threshold that inhibits operation of the feed-forward function to those times during which the threshold is exceeded. Output of the differential amplifier 71 is applied to one input of the OR gate 42. Optionally hysteresis of operation is provided by means of a resistor 72 connected in a feedback path of the differential amplifier 71.
Even with the feed-forward circuit, it can be still advantageous to push the bandwidth of the gain control loop into the region of the inherent pole. In either digital or analog implementations, the impediment to stable operation over all operating conditions is the movement of the location of that pole in the amplifier response.
The position of the pole can be predicted from the input, output, and pump powers for a particular amplifier. To obtain the required speed, the pole location is measured or calculated in advance, and stored in a table in the microprocessor's non-volatile storage. The location of the pole-cancelling zero is adjusted within the control loop that maintains the optical amplifier gain.
The design of the feed-forward block 35 described above with particular reference to FIGS. 4 to 7 is one specifically designed to handle sudden negative transients. The provision of such protection is typically of more importance than that for handling positive transients because it is possible to guard against the occurrence of positive transients by ensuring that, whenever an additional optical data channel is brought on line, its power level is ramped up sufficiently slowly having regard to the response time of the control system 30. Nevertheless, if protection against the effects of sudden positive transients is additionally desired, such protection can be provided in a way similar to that described above in relation to the handling of negative transients.
Attention is now turned to an example of a different form of non-linear control of the gain of an optical amplifier. This also involves regulation of the drive current applied for optical pumping of the amplifier, but in this instance the switched non-linearity of operation is provided by switching the bandwidth of the control loop system regulating the drive current in response to the control signal input representative of the optical signal power received for amplification by the amplifier. The bandwidth is switched between a high value in the presence of sudden transients (this high value being high enough to provide a rapid response to these transients), and a lower value in the absence of such transients (this low value being such as to maintain substantial noise and artefact filtering together with stability of operation during substantially steady state operating conditions of the amplifier).
Referring to FIG. 8, this non-linear control employs substantially the same functionality of control loop 30 as the non-linear control of FIG. 3 but omits the feed-forward block 35, substituting for it a trigger whose basic functional components are indicated within the broken line rectangle 80. These components include an isolation buffer 81 and low pass noise filter 82, a second low pass filter 83 with a longer time constant, a parallel resistor 84 which can be switched in, under the control of a gate 85, to shorten the time constant of filter 83. The outputs of filters 82 and 83 are fed, together with an activation threshold A 1 , to a differential amplifier 86 whose output provides an input to an OR gate 87, the time constant of filter 83 is matched with the response of the control loop 30 when operating under steady state conditions. This can be a constant set to the nominal response of the control loop. Advantageously, either the low-pass filter corner frequency or the control loop gain is adjusted by the microprocessor to keep a close match despite variations occurring in the optical amplifier operating conditions. The filter 83 therefore provides, to the amplifier 86, an input V ref that is representative of the mean level of optical power input P in , while the filter 82 provides an input representative of the instantaneous value of P in . In the presence of a sudden negative transient of sufficient magnitude as determined by the activation threshold A 1 , the amplifier provides an output which is transmitted by the OR gate 87 to switch the gain K of the amplifier 32 of control loop 30 to a higher value, so triggering that control loop into a wide-band mode. At the same time the output from the OR gate 87 is also employed to operate the gate 85 so as to bring about a matching change to the time constant of filter 83 by the shunting effect of resistor 84. A feedback resistor 88 across the amplifier 86 provides a measure of hysteresis of operation. At the end of the negative transient, the input to the OR gate 87 is removed, with the result that the control loop 30 and trigger 80 are restored to their former steady state operating conditions. Provision for responding to positive transients may be provided by adding the functionality of the components within the broken line rectangle 89, these components comprising a second amplifier 86 2 and hysteresis resistor 88 2 , and a second activation threshold A 2 .
The non-linear feed-forward control of FIG. 2 can be applied to optical transmission systems employing bidirectional optical amplifiers such as described in U.S. Pat. No. 5,801,858. It should be noted however that the operation of such feed-forward control in a bidirectional amplifier is liable to be adversely affected by reflection of optical power output from such an amplifier back into itself because such reflections can be at power levels comparable with those of the input signals that it is intended that that amplifier shall amplify. These reflections have both a DC effect and an AC effect. The DC effect is to distort the evaluation of the transient relative magnitude. The AC effect results when a transient in the input signal power in respect of a signal propagating in one direction is completely suppressed in its transmission through the amplifier, is partially reflected, and the partially reflected light re-enters the amplifier as a spurious transient superimposed on the wanted signal propagating in the opposite direction. One way of suppressing such unwanted effects will now be described with reference to FIG. 9.
The arrangement of FIG. 9 is in respect of a system in which the signals propagating in one direction are all signals at wavelengths longer than those of signals propagating in the other direction, and so the two directions of propagation are respectively referred to hereafter as the red direction and the blue direction. This FIG. 9 similarly shows in schematic form features which are conveniently in practice by operation of a conventional microprocessor. The gain control system of FIG. 9 is formed in two parts, one providing red direction gain control, and the other blue direction gain control. Each of these parts operates in a similar manner to that described above with reference to FIG. 3. Thus each has a feed-back control system 90 R , 90 B , in parallel with a feed-forward control system 95 R , 95 B , corresponding respectively with the feed-back and feed-forward control systems 30 and 35 of FIG. 3. Similarly, the outputs of the feed-back and feed-forward control systems 90 R , and 95 R , and 90 B , and 95 B , are applied to respective multipliers 96 R , and 96 B , to provide respective pump laser diode drive currents. I pump Red and I pump Blue. In this instance, however, the input power signals P in Red and P in Blue are not applied direct to the inputs of the feed-forward control systems 90 R and 90 B , but are applied via summers 91 and 92. The second inputs, negative inputs, to these summers 91 and 92 are provided by the outputs of two multipliers 93 and 94. The inputs to multiplier 94 are respectively P in Red and Reflection Blue, while those of multiplier 93 are P in Blue and Reflection Red. Reflection Red and Reflection Blue are signals generated by the microprocessor using the reflectometer features disclosed in U.S. Pat. No. 4,859,018, or the reflectolocator feature disclosed in United Kingdom Patent No 2 292 495 to determine the static levels of red and blue direction reflections at a given output. The microprocessor generates two DIA voltages: `Reflection Red` and `Reflection Blue` that are proportional to the measured reflection, to the optical amplifier gain setting, and to the relative transimpedance gain settings of the two input monitors. All of these parameters are known to the microprocessor, and are digitally multiplied and then scaled to the D/A. These two reflection voltages each multiply the input monitor values in multipliers 94 and 93. Each product is then subtracted from the opposite transient input in the summers 91 and 92, this conveniently being effected at the isolation buffers of the feed-forward systems 95 R and 95 B . This compensates for the DC effect of the reflection, and for the transient effect of reflection of signals containing transients. Inputs are used for subtraction, rather than the outputs to avoid all analog cross-coupling and the resultant stability issues. The digital cross-coupling path, via two reflections and reflection measurements, always has a gain much less than unity because the reflectometer update rate is very slow. The high pass filter inherent in the V ref comparison, and the heavy low pass filtering on the D/A Reflection outputs (not shown in the diagram), ensure high loss around the path at low frequencies. The low pass filtering on the outputs serves to prevent nonlinear transient generation via a step change in the D/A value. (This can be effected in either analog or digital mode).
Attention is now turned to an example of a further form of non-linear control of the gain of an optical amplifier. This form involves regulation of the power output of an optical pump pumping the amplifier in a feedback manner using a feedback control signal derived from a measure of optical power output by the optical amplifier. The feedback control involves the use of two feedback loops, one of which is operational only when transients of a certain magnitude are present, and the other of which is operational only when they are absent. By obtaining the feedback control signal from the output power of the optical amplifier, the amplifier gain tilt does not affect the accuracy with which the magnitude of transients are determined, while the feedback nature of the control structure in general provides more accurate control.
The general structure of this feedback gain transient suppression mechanism is depicted in FIG. 10. The two feedback control loops can each be implemented in a microprocessor, or in hardware if a faster control response is desired. FIG. 10 depicts the optical amplifier 20 inserted in the transmission path 13. The optical pump for the amplifier 20 is depicted at 21. A proportion of the optical output of amplifier 20 is tapped off by optical tap 22 and fed to a monitor photodiode 100 whose output is fed to an amplifier 101. The output of this amplifier 101 is fed to an output power controller 102 that in normal operation provides an output which is fed through a summing device 103 on to a control line 104 that regulates the optical output of pump 21. This completes the output power feedback control loop. The basic components of the controller 102 of the control loop are similar to those of the controller 30 of FIG. 3, except for the omission of the ratio meter 31 of the FIG. 3 controller.
The output of the monitor photodiode output amplifier 101 is also fed to a further controller 105, the gain transient controller, similar to controller 102, but receiving its target input from the output of a negative peak detector 106. The output of the gain transient controller 105 is fed through a gain transient control enable/disable switch 107, through the summing device 103 on to the control line 104, thereby completing the transient feedback control loop.
Additionally the output of the monitor photodiode output amplifier 101 is fed to the input of the negative peak detector 106 and to a transient detector 108. This transient detector 108 can for instance be implemented in a manner similar to the implementation of the transient relative magnitude indicator and threshold detector combination 40 and 41 of FIG. 4. It can alternatively for instance be implemented in a manner similar to that employed in the arrangement of FIG. 8 in which the outputs of two low pass filters 82 and 83 with different time constants are compared using a differential amplifier 86.
The detection and suppression of transients can be accomplished by making use of the fact that in the event of a sudden uncompensated negative transient, arising for instance from the sudden removal of one or more of a group of wavelength multiplexed signals received by the optical amplifier, the total power output of the amplifier drops to the power level of the surviving channels, before increasing again to the original output power level existing prior to the onset of the transient.
At the onset of such a transient, the sudden reduction in optical output power issuing from the amplifier 20 produces a corresponding reduction in signal from the output of the monitor photodiode amplifier 101. If this is large and fast enough, it triggers operation of the transient detector 108 to provide an output on an enable/disable line 108a. This line is connected to the switch 107 and to both controllers 102 and 105. A signal on line 108a disables output power controller 102, holding constant its output at the summer 103. It closes switch 107, and enables the gain transient controller 105, so that the controller's output is now connected to summer 103. The open loop transfer function of controller 105 is typically a PID (proportional plus integral plus derivative) function with control parameters chosen to ensure adequate suppression speed and desired stability margins over the required operating conditions. The gain transient controller 105 responds much faster than controller 102. Using the output of the negative peak detector 106 as the target of controller 105 ensures an adequately smooth transition from the operation of the feedback control loop incorporating the power output controller 102 to the operation of the loop incorporating the gain transient controller 105.
The appearance of the signal appearing on line 108a also triggers the starting of two timers (not shown), the first of which regulates the duration for which the feedback control loop incorporating the gain transient controller 105 is to remain operative, and the second of which regulates the duration for which the feedback control loop incorporating the power output controller is to remain inoperative. The duration set by the second timer is longer than that set by the first. The duration set by the first timer is set to be longer than the largest possible transient time so that the gain transient controller 105 shall not be disabled until after such a transient has passed. When the first timer has run its course, the gain transient controller 105 is disabled and the switch 107 is opened. A substantially smooth transition between the ceasing of operation of the feedback control loop incorporating the gain transient controller 105, and the recommencement, when the second timer has run its course, of the operation of the feedback loop incorporating the power output controller 102, is provided by the time constant of the decay of charge appearing on a capacitor 107a through a resistor 107b.
Preferably the construction of the two feedback control loops is such that the power output controller 102 acts as a master to the gain transient controller 105 so that gain transient detection, and hence compensation, can be disabled in the event of unfavourable operating conditions such as optical amplifier start up, changes to transimpedance amplifier gain setting, amplifier oscillation and the like. | In an optical transmission system employing optical amplifiers a method of regulating the gain of such an amplifier uses a non-linear control system whose non-linearity of operation is provided at least in part by the enabling/disabling of a portion of the control system by the operation of a transient magnitude threshold sensor. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a shrinkage band for a CRT, and more particularly, to a shrinkage band combined to a CRT adopting a panel with a flat outer surface and a curved inner surface recently emerging as a new trend, which is capable of preventing occurrence of a explosion phenomenon on the panel.
2. Description of the Background Art
As is widely known, a CRT is a display instrument used for an observation of an oscilloscope or a radar as well as a television set.
The CRT serves to transmit a color image for users' viewing which is reproduced in a manner that a phosphor screen consisting of fluorescein pixels, that is, an electrooptic device, converting a video data received as an electric signal to a visual information, graphite, that is, an optical absorption substance, and an aluminum film improving a luminance, is hit by an electronic beam.
FIG. 1 illustrates a construction of a general CRT in accordance with a conventional art.
As shown in the drawing, the conventional CRT includes a panel 1 positioned in the front surface and a funnel 2 adhesively attached to the rear end of the panel 1 , forming a vacuum outer casing container.
An electric gun 5 radiating an electric beam 4 is hermetically sealed inside a neck portion 3 , that is, the end portion having relatively smaller diameter in the funnel 2 . A deflection yoke 9 for generating a pin-cushion-type horizontal deflection magnetic field and barrel-type vertical deflection magnetic field, is mounted in the outer circumferential side in the vicinity of the neck portion 3 , so as to deflect the radiated electronic beam to the whole screen.
A phosphor film 6 is formed on the inner surface of the panel 1 , and a shadow mask 7 having a section-based electrode function is supported by a frame 8 installed therein, spaced apart at a predetermined distance from the phosphor film 6 .
In the conventional CRT constructed as described above, the electronic beam 4 radiated from the electronic gun 5 is deflected to a desired portion of a screen by the vertical and horizontal deflection magnetic fields of the deflection yoke 9 , and as the electronic beam passes through a plurality of through holes (not shown) formed at the shadow mask 7 , it hits the phosphor film 6 , thereby creating a picture.
Since the inside of the conventional CRT constructed as above makes a vacuum state by the panel 1 and the funnel 2 , a stress is applied to the panel due to an external atmosphere pressure. That is, as shown in FIG. 2, according to the structural characteristics of the CRT, the front surface portion of the panel 1 receives a compressive stress while the side portion thereof receives a tension stress.
Thus, in a state that the compressive stress and the tension stress work due to the vacuum, when an external impact is applied to the CRT, a explosion phenomenon possibly causing that the panel 1 or the funnel 2 is exploded may occur, which, thus, causes a malfunction to the CRT as well as threatening users' safety.
In order to prevent such a explosion phenomenon, a shrinkage band 10 is typically combined to continuously cover the external side portion of the panel 1 .
The panel 1 is formed of a glass, which is weaker over the tension stress compared to the compressive stress in its property, and accordingly, the side portion of the panel 1 is structurally weaker compared to the front surface portion thereof.
Therefore, the shrinkage band 10 is combined to the CRT so as to strengthen the rigidity of the side portion of the panel 1 where the tension stress is concentrated, to thereby prevent the explosion phenomenon.
In detail, when an impact is applied to the surface of the CRT, a deformation stress, that is, a tension stress, expanding the side portion of the CRT is generated, which is, however, restrained by the rigidity of the shrinkage band 10 that compresses the side portion, so that a crack possibly caused passing the side portion and the surface portion can be restrained or the speed of the crack can be lowered down. And, at the same time, the direction of the main stress to the surface portion of the panel 1 and the proceeding direction of the crack are changed, thereby preventing the explosion phenomenon.
According to a research, the maximum tension stress working on the side portion of the panel 1 was observed by 87.9 kgf/cm 2 without the shrinkage band 10 , while when the shrinkage band is combined to the side portion of the panel 1 , the maximum tension stress was observed by 79.0 kgf/cm 2 .
The panel 1 is typically fabricated by molding. When the panel is fabricated by molding, a mold match line is formed in the panel 1 , and the shrinkage band 10 is generally combined to the CRT in a manner that it covers the mold match line 11 , as shown in FIGS. 3A-3B.
Referring to kinds of the shrinkage bands, there are a straight line-type shrinkage band 10 ′ which is directed to highly improve an adherence of the shrinkage band itself for heightening the compression efficiency as shown in FIG. 3A and a fold-type shrinkage band 10 ″ directed to strengthening a compression force in the front portion of the panel 1 as shown in FIG. 3 B.
Theoretically, though it is desired to install the shrinkage band 10 ″ on the basis of the center of the curved portion of the corner portion, making a break-even point of the compression efficiency, of the inner surface of the panel 1 , since the mold match line 11 and the position of the center of the curved portion of the corner are almost the same owing to the spherical panel form, substantially the mold match line 11 is easily identified in view of form is used as an installment reference to the shrinkage band 10 .
In detail, since, on the basis of the mold match line 11 , the upper portion of the shrinkage band 10 compresses the front portion of the panel 1 and the lower portion of the shrinkage band 10 compresses a skirt portion of the panel 1 , the shrinkage band 10 is to be positioned suitably on the basis of the mold match line 11 in order to improve a explosion prevention capacity.
For example, if the shrinkage band 10 is inclined toward the lower portion (the skirt portion of the panel 1 ) of the mold match line 11 , many cracks can be made in the CRT due to an external impact, or in a worse case, the panel 1 may be separated from the CRT.
Reversely, if the shrinkage band 10 is inclined toward the upper portion (the front portion of the panel 1 ) of the mold match line 11 , a explosion or a crack can be easily made in the skirt portion of the panel 1 due to an external impact.
Actually, when the shrinkage band 10 is combined to the CRT, in order to accomplish optimum explosion-proof characteristics, the mold match line 11 is typically designed in a manner that the compression force of the upper portion is weak compared to that of the lower portion. Taking an example that the spherical panel as in the conventional art is adopted to the CRT, it is designed in a manner that the compression force of the upper portion of the mold match line 11 does not go beyond 90% compared to the compression force of the lower portion.
As another way of preventing the explosion, besides the shrinkage band 10 , a strong glass having an improved explosion prevention characteristics by heightening its rigidity may be used for the panel 1 , or a film may be attached onto the surface of the panel 1 so as to provide a explosion prevention function.
Meanwhile, recently, as a screen is turning large-sized and flat in order to provide a distinct image, there has been proposed a panel (termed as a ‘flat panel’, hereinafter) of which an outer surface is flat while inner surface is curved. This kind of panel offers a distinct image compared to the general spherical panel as used in conventional arts, implementing a highly-refined picture, but the corner portion of the panel is formed thick compared to that of the general spherical panel.
That is, the thickness ratio between the center and the corner of the general spherical panel is approximately 1.3, while in case of the flat panel, the thickness ratio between the center and the corner is approximately 1.8˜2.0.
Accordingly, in case that the reference for distribution of the compression force of the shrinkage band of the flat panel is applied by the mold match line in the same manner as in the case of general spherical panel, the position of the shrinkage band becomes relatively inclined backwardly of the panel, causing a weakness in the front side of the panel, which creates a problem in that there is a high possibility that a crack or a explosion is made in the front side of the panel.
Meanwhile, in order to prevent such a explosion phenomenon, the strong glass may be employed to the panel or the film may be attached onto the surface of the panel. However, in the former case, a production cost is inevitably increased in spite of the explosion prevention effect, while in the latter case, its expense is increased and recycling is impossible.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide a shrinkage band for a CRT combined to a flat panel in a suitable position which is determined from the forward or backward direction of the panel on the basis of a line extended in the horizontal direction from the center of the curved portion of the corner of the inner side of the flat panel, so as to prevent a explosion phenomenon on the flat panel.
To achieve these and other advantages and in accordance with the purposed of the present invention, as embodied and broadly described herein, there is provided a shrinkage band for a CRT including: a panel forming a display screen; and a shrinkage band having a predetermined width combined to cover the outer circumferential surface of the side portion of the panel in a state of satisfying an inequality 0.95≦F a /F b ≦1.39 on the assumption that an engagement tensile force of the front side of the panel is F a and that of the opposite side of the front side of the panel is F b , on the basis of the line extended in the horizontal direction of the panel from the center of the curved portion of the corner of the inner side of the flat panel.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.
In the drawings:
FIG. 1 illustrates a construction of a general CRT in accordance with a conventional art;
FIG. 2 illustrates a stress distribution of the general CRT in accordance with the conventional art;
FIG. 3A is a partial view showing a straight line-type shrinkage band combined to the general CRT in accordance with the conventional art;
FIG. 3B is a fold-type shrinkage band combined to the general CRT in accordance with the conventional art;
FIG. 4 is a graph showing a proof-explosion property of the shrinkage band combined to a CRT in accordance with the present invention;
FIG. 5A is a partial view of a straight line-type shrinkage band combined to the CRT in accordance with first embodiment of the present invention;
FIG. 5B is a partial view showing that a folded portion of the fold-type shrinkage band combined to the CRT is extended to the lower portion of the center of the curved side of the corner portion of the inner surface of the panel in accordance with a second embodiment of the present invention; and
FIG. 5C is a partial view showing that the folded portion of the fold-type shrinkage band combined to the CRT is positioned at the upper portion of the center of the curved side of the corner portion of the inner surface of the panel in accordance with a third embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
There may be plurality of embodiments of the present invention, and the most preferred embodiment is described in detail hereinbelow, though which objects and advantages of the present invention will be understood enough. In explanation for the drawings, the same reference numerals are given for the same construction elements in FIG. 1 through FIG. 3B, for which the same descriptions are omitted.
The present invention is directed to combine a shrinkage band at an optimum position to a flat panel, that is recently spotlighted, in order to prevent an occurrence of a explosion phenomenon.
In this respect, referring to the flat panel, if the shrinkage band is combined on the basis of a mold match line, since there is much difference between the thickness of the center portion and that of the corner portion of the flat panel, relatively, there is a high possibility that a explosion phenomenon occurs in the front surface portion of the flat panel.
Accordingly, as to the flat panel 100 adopted to the present invention, the curvature is steeply changed at the corner portion 100 a , and generally, the compression effectiveness diverges on the basis of the center ‘O’ of the curvature of the corner portion 100 a , so that, as shown in FIGS. 5A and 5C, the installation of the shrinkage band is set on the basis of the line 12 extended in the horizontal direction of the panel 100 from the curvature center ‘O’ of the corner portion 100 a of the inner surface of the flat panel 100 .
Generally, the engagement tensile force (F) of the shrinkage band is computed by an equation of F=σ×T×d (σ indicates an yield strength, T indicates the thickness of the shrinkage band, and W indicates the width of the shrinkage band). In this respect, since the thickness of the shrinkage band combined to an arbitrary CRT and its yield strength are generally the same for any shrinkage band, the engagement tensile force (F) is considered to be in proportion to the width of the shrinkage band.
FIG. 4 is a graph showing a result of an experiment on explosion characteristics, for which a shrinkage band is combined while changing the engagement tensile forces on the basis of the line 12 extended in the horizontal direction of the panel 100 from the curvature center ‘O’ of the corner portion 100 a of the inner surface of the flat panel 100 .
In detail, in case that the shrinkage band is positioned to be inclined to the lower portion side (the front portion of the panel 100 is termed as the ‘upper portion’ while the opposite portion to the front portion of the panel 100 is the ‘lower portion’, hereinafter) on the basis of the line 12 extended in the horizontal direction of the panel 100 from the curvature center ‘O’ of the corner portion 100 a , the engagement tensile force (F) of the upper portion of the flat panel 100 is relatively weaker than that of the lower portion of the flat panel 100 , so that when an external impact works on the surface of the flat panel 100 , a large amount of crack can occur on the surface of the flat panel 100 due to the impact, and in a worse case, there is a possibility that the surface of the flat panel 100 is separated from the CRT
Conversely, in case that the shrinkage band is positioned to be inclined to the upper portion side on the basis of the line 12 extended in the horizontal direction of the panel 100 from the curvature center ‘O’ of the corner portion 100 a (for example, in case that the engagement tensile force of the upper portion is relatively 40% greater than that of the lower portion), when an external impact is applied to the surface of the flat panel 100 , a progressive crack may occur as time goes by after the impact.
At this time, though the band strongly compresses the upper portion to prevent the external impact from dispersively transmitting from the upper portion to the lower portion of the flat panel 100 , a check mark that a minor flaw occurs on the flat panel 100 appears as well as a possibility of a explosion.
Therefore, the shrinkage band should be suitably positioned on the basis of the line 12 extended in the horizontal direction of the panel 100 from the curvature center ‘O’ of the corner portion 100 a of the inner surface of the flat panel 100 , for which an optimum engagement tensile force ratio for the shrinkage band is shown in the below inequality [1] as illustrated in FIG. 4 .
0.94 ≦F a /F b ≦1.39 [1],
where F a indicates an engagement tensile force of the front portion of the panel of the shrinkage band on the basis of the line 12 extended in the horizontal direction of the panel 100 from the curvature center ‘O’ of the corner portion 100 a of the inner surface of the flat panel 100 , and F b indicates an engagement tensile force of the opposite side to the front portion of the panel of the shrinkage band on the basis of the line 12 extended in the horizontal direction of the panel 100 from the curvature center ‘O’ of the corner portion 100 a of the inner surface of the flat panel 100 .
In this respect, as aforementioned, since the yield strength and the thickness of the shrinkage band to be combined to an arbitrary CRT are the same for any shrinkage band, the engagement tensile force of the shrinkage band is proportional to the width of the shrinkage band.
Accordingly, the ratio of the engagement tensile force of the shrinkage band can be expressed by a ratio of the width of the shrinkage band, which will now be explained according to embodiments in view of a combined type of the shrinkage band.
FIG. 5A illustrates a straight line-type shrinkage band 10 ′.
In the drawing, when the width of the upper portion of the shrinkage band 10 ′ is d a and the width of the lower portion is d b on the basis of the line 12 extended in the horizontal direction of the panel 100 from the curvature center ‘O’ of the corner portion 100 a of the inner surface of the flat panel 100 , the engagement tensile force ratio of the shrinkage band 10 ′ is determined only by the width of the shrinkage band, which can be expressed by the following inequality [2].
0.95 ≦F a /F b =d a /d b ≦1.39 [2]
Meanwhile, in case of the fold-type shrinkage band 10 ″, the engagement tensile force of the shrinkage band 10 ″ is different depending on how long the folded portion is extended on the basis of the line 12 extended in the horizontal direction of the panel 100 from the curvature center ‘O’ of the corner portion 100 a of the inner surface of the flat panel 100 .
That is, FIG. 5B shows a fold-type shrinkage band 10 ″ of which the folded portion is extended to the lower portion of the line 12 extended in the horizontal direction of the panel 100 from the curvature center ‘O’ of the corner portion 100 a.
In the drawing, assuming that the width of the upper portion of the shrinkage band 10 ″ is d a , the width of the lower portion of the shrinkage band 10 ″ is d b1 , and the width of the lower portion of the folded portion of the shrinkage band 10 ″ is d b2 , the engagement tensile force ratio of the shrinkage band 10 ″ can be expressed by the following inequality [3].
0.95 ≦F a /F b =(2× d a )/( d b1 +d b2 )≦1.39 [3]
Meanwhile, FIG. 5C shows a fold-type shrinkage band of which the folded portion is formed at the upper portion of the line 12 extended in the horizontal direction of the panel 100 from the curvature center ‘O’ of the corner portion 100 a.
In the drawing, assuming that the width of the upper portion of the shrinkage band 10 ″ is d a1 , the width of the upper portion of the folded portion of the shrinkage band 10 ″ is d a2 and the width of the lower portion of the shrinkage band 10 ″ is d b1 the engagement tensile force ratio of the shrinkage band 10 ″ can be expressed by the following inequality [4]:
0.95 ≦F a /F b =( d a1 +d a2 )/ d b ≦1.39 [4]
In this manner, the engagement tensile force ratio of the shrinkage band combined on the basis of the line 12 extended in the horizontal direction of the panel 100 from the curvature center ‘O’ of the corner portion 100 a of the inner surface of the flat panel 100 can be expressed by the ratio of the width of the shrinkage band, and when the shrinkage band is combined to the flat panel by suitably setting the engagement tensile force ratio of the shrinkage band, the stress generated in the CRT is evenly distributed. And, when an external impact is applied onto the surface of the flat panel 100 , the impulsive wave can be evenly dispersed to the surface and the skirt portion of the flat panel 100 , so that an optimum explosion characteristics can be accomplished.
As so far described, according to the shrinkage band for a CRT of the present invention, the shrinkage band is suitably positioned to be combined to the flat panel gaining much popularity, so that the explosion characteristics of the flat panel can be highly improved along with an effectiveness that a reliability can be enhanced and a stability in use can be obtained.
As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the meets and bounds of the claims, or equivalence of such meets and bounds are therefore intended to be embraced by the appended claims. | A shrinkage band for a CRT including: a panel forming a display screen; and a shrinkage band having a predetermined width combined to cover the outer circumferential surface of the side portion of the panel in a state of satisfying an inequality of 0.95≦F a /F b ≦1.39 on the assumption that an engagement tensile force of the front side of the panel is F a and that of the opposite side of the front side of the panel is F b on the basis of the line extended in the horizontal direction of the panel from the center of the curved portion of the corner of the inner side of the flat panel. With the construction, the explosion characteristics of the flat panel can be highly improved along with an effectiveness that a reliability can be enhanced and a stability in use can be obtained. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to a moulding press for a transfer- or injection-moulding machine, comprising two mould halves which can be moved relative to each other, in which the connection between said mould halves comprises joint lever means consisting of two arms which are connected in a hinge-like manner to each other, the free ends of which are connected in a hinge-like manner to the upper and lower mould halves and in which a control arm engages on the hinge point of the arms, the other end of which control arm engages on a cam track of a cam disc, the cam disc being mounted rotatably on the frame of the moulding press.
Such a moulding press is disclosed in the German Offenlegungsschrift 2,252,953. In this moulding press, a joint lever means is present and the cam disc is provided with a closed track. To prevent movement of the end of the control arm which engages on the cam track, said arm is connected in a hinge-like manner to a rod which is connected to the frame of the device. There is a horizontal guiding for the control arm, which guiding permits a deflection with respect to the horizontal position with the aid of a spring construction.
If relatively large forces, such as occur, for example, in transfer- or injection-moulding devices, have to be transmitted by means of such a device, a construction of this kind becomes very inefficient. After all, the cam disc is subjected to a high one-sided load and therefore the disc will have to be of a correspondingly robust design. This means that a relatively large drive will have to be installed adjacent to the transfer- or injection-moulding device. In addition, the various arms of the construction will have to be of a correspondingly robust design.
The object of the present invention is to provide a control mechanism for the above mentioned moulding press, which does not have these disadvantages.
SUMMARY OF THE INVENTION
This object is achieved in a moulding device described above in that there are two spaced-apart joint lever means, between which the cam disc is fitted, and in that, moreover, the control arms, with the end that engages on the cam track, engage on a linear guiding, which guiding extends essentially perpendicularly to the direction of movement of the mould halves.
By designing the joint lever means in duplicate, they can each have a lighter structure while a considerable force can still be applied. By using two joint lever means, the forces which are consequently generated and which do not relate to the opening or closing are compensated for. The use of a linear guiding for the control arms is necessary to enable a cam track to be produced in a simple way. When the cam disc rotates and the engagement point of the control arms is applied to both sides with respect to the core, the inclination of the cam track at the application point of the control arm will be in the opposite direction. By mounting the cam disc between the joint lever means, it can be integrated into the moulding press. An equal distribution of the load on the cam disc is achieved, as a result of which it can be designed so as to be relatively small so that the constructional height of the moulding press is unaffected, or hardly affected.
It is noted that the U.S. Pat. Nos. 3,830,614 and 2,269,758 disclose drives for a moulding press in which use is made of a crank gear in place of a cam disc. With these, it is not possible to control the opening and closing of the moulding press as required, which is, however, the case with a cam track. U.S. Pat. No. 4,776,783 discloses a joint lever mechanism which does not use a cam disc.
In the device according to German Offenlegungsschrift 2,252,953 both mould halves have to be mounted so as to be movable with respect to the frame by means of a coupling between control arm and frame. Said coupling is not present in the invention and therefore a mould may be connected to the frame.
The invention is based on the idea that a relatively small force and relatively large travel are required so that the control arm can apply a relatively small travel and large force on the mould halves. By means of the rotating disc it is possible in a simple manner to make the control arm perform a controlled movement. In this case, the rotating disc is in particular a cam disc. By adjusting the shape of the cam track, the movement of the control arm can be controlled and thus the closing and opening movement of the mould halves can be controlled. Guiding means may additionally be present to further guide the end of the control arm which engages on the cam disc, which guiding means ensure as far as possible that the control arm moves perpendicularly relative to the movement of the mould. An optimum simple construction is achieved if the control arm is connected to the hinge point of the arms of the joint lever means.
By means of the abovementioned construction it is possible, starting from an open position, to perform the closing movement initially relatively quickly, followed by slower movement in order thereby to be able to insert the product to be encapsulated, such as an integrated circuit in a chip housing, accurately into the mould halves in a controlled manner.
In this case, it is, of course, important that, when the mould is completely closed, the control element can absorb the force exerted by the transfer part of the device. According to a very efficient embodiment in terms of dimension and construction, the control means are placed in a position lying below the mould means and the lower mould is securely connected to the surroundings.
The invention also relates to a method for controlling the moulding press, comprising moving the mould halves with a relatively small force from the open position towards each other, measuring the distance between the mould halves after the closing movement has finished and applying a greater force on the mould halves if the measured distance is within a certain range. The application of a greater force may be controlled by means of a closed-loop control. To apply the force, use is made, for example, of a motor which can generate a considerable torque in the idling state, depending on the power supplied to it. This power is in turn dependent on the pressure measured in the mould halves.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in more detail below by means of an exemplary embodiment illustrated in the drawing, in which:
FIG. 1 diagrammatically shows a front view of the moulding press according to the invention, in the open position;
FIG. 2 shows a side view of the device according to FIG. 1, in the open position;
FIG. 3 shows a cross section along the line III--III of FIG. 1;
FIG. 4 shows a side view of a detail of the feed and discharge system for lead frames in the mould;
FIG. 5 shows a detail of the opening and closing mechanism of the moulding press;
FIG. 6 shows a detail of the press plunger for injecting plastic into the mould cavity, and
FIG. 7 shows a detail of the upper and lower mould and a diagrammatic illustration of a closed loop for the control of the moulding pressure.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The press device according to the invention comprises a frame 1, as shown in FIGS. 1 and 2. A cross plate 2 is provided in frame 1, onto which crossplate 2 a lower mould 72 is fitted in a fixed manner. Provided in cross plate 2 are guide bores 3, through which tie bars 78 are guided so as to be slidable to and fro. A carriage 79 is guided on the tie bars 78 in a slidable manner. Control of the carriage 79 is effected by a lead screw 77. On carriage 79 is fitted the moulding part of the device, which part will be described in more detail below. Tie bars 78 are connected on one side to the upper mould 70 and, on the other side, to the lower plate 4. The lower plate 4 is connected via a joint lever mechanism 5 to upper plate 6, which upper plate 6 is connected, via pressure sensors 7, to the carrying plate 8 which, together with cross plate 2, is firmly connected to frame 1. Motors 9 and 75 are fitted on carrying plate 8. Sensor 50, of carrying plate 8, is arranged to co-operate with protruding part 51 which is mounted on bar 78. Motor 9 is linked to a cam disc 11 via a transmission 10, an arm 13 of the joint lever mechanism 5 engaging on the cam tracks 12 of said cam disc. This arrangement is shown more clearly in FIG. 5. As can be seen in this figure, in addition to arm 13, arms 14 and 15 are also present. In addition to being guided in the cam tracks 12, thearms 13 are guided in a horizontal guiding groove 16 which is firmly connected with upper plate 6. As a result of their combined guiding in thecam tracks 12 and the horizontal guiding groove 16, the fastening points ofthe arms 13 at the cam disc can only carry out a reciprocating movement in the horizontal plane of FIG. 5 when the cam disc 11 rotates.
The moulding part of the device operates as described below.
When the motor 9 is driven, which motor 9 is a motor of the type which can deliver a considerable moment even during idling, the cam disc 11 will rotate. Starting from the position shown in FIGS. 1 and 5 and assuming that motor 9 rotates anti-clockwise, the arms 13 which are in the horizontal guiding groove 16 will be moved towards each other, i.e. towards the center of the cam disc, by means of the cam tracks 12. As a result thereof the arms 14 and 15 are moved apart and consequently the lower plate 4 moves down relative to the fixed carrying plate 8. A specialcourse of the movement can be achieved by a simple design of the groove 12.During the first part of the closing movement, the motor 9 is controlled insuch a manner that it delivers a relatively low moment. Therefore, if the two halves of the mould for some reason cannot be closed completely (if anobject to be encapsulated has been inserted the wrong way round), this willnot result in damage, but the closing movement will be brought to a halt. In this case, pre-tensioned spring constructions, such as are being used in the state of the art, are undesirable. After the closing movement has stopped at the relatively low torque, sensor 50 and protruding part 51 areused to determine whether the mould halves are positioned one on top of theother. Should this not be the case, an alarm signal is emitted. If correct positioning is confirmed, the motor is controlled in such a way that it delivers a higher torque during idling and thus the closing force exerted on the mould halves is sufficient to overcome the transfer and hardening pressure. In this case, the arms 14 and 15 are preferably virtually in thevertical position, whereby maximum transmission is provided between the motor 9 and the force exerted on the upper mould 70. After moulding has finished, the upper mould 70 may be moved away from the lower mould by driving the motor 9 in the opposite direction.
When the mould halves 70 and 72 are being closed together, a so-called leadframe 19 must be present in the mould cavity which is denoted overall by 18in FIG. 7, which lead frame contains an integrated circuit (not shown). With regard to the supply of said lead frame, particular reference is madeto FIG. 3 and 4, which show that two stops 34 and a supporting plate 20 fastened thereto are connected to bars 78. A carriage 21 which, as can be seen in FIG. 4, rests on stops 34, is guided slidably by means of rollers 22 on bars 78. An aperture 23 is provided in carriage 21, in which aperture a stop 24 connected to an ejection device 54 (FIG. 7) is present.The dimensions of aperture 23 and stop block 24 are adapted to one another in such a way that the carriage 21 can travel half the complete stroke of the upper mould. Carriage 21 is connected to the piston rod 25 of air cylinder 26 which, as is shown in FIG. 2, is firmly connected to carrying plate 8. Cylinders 27 are present on carrying plate 8 or cross plate 2 or supporting plate 20, which cylinders act on an upper gripper 32. At its upper side, carriage 21 is fitted with arms 28 and 29. A gripper cylinder 35 is provided in the carriage 21, which gripper cylinder 35 acts, on the other side, on an upper gripper 32 which co-operates with lower gripper 33(see also FIG. 2). Upper gripper 32 is equipped with gripper fingers 36 (FIG. 3). Lower gripper 33 is likewise equipped with fingers (not shown) for gripping lead frame 19. Drive cylinders 31 are provided for moving degate plate 37 (cf. FIGS. 3 and 7) to and fro. A conveyor belt 38 and a conveying plate 30 are firmly attached to arm 28 of carriage 21 in a manner not shown in further detail, i.e. they move along with upper mould 70. Conveying plate 30 is designed to engage on the lead frame 19. The operation of the abovementioned conveying mechanism is described below.
When the upper mould half is in the completely open position, the arms 28 and 29 are in the position shown in FIG. 4. During this state, the conveying of the lead frame is effected by means of the conveying plate 30and belt 38. After the lead frame has been inserted in the grippers 32, 33,the arms 28, 29 will move down towards the supporting plate 20 together with the upper mould when this is moved downwards. In this case, the conveying plate moves along in a vertical direction and is able to move back in a horizontal direction. During the downward movement, the upper and lower grippers are closed in order to hold the lead frame between them. Gripper 32 abuts cylinders 27 (which extend) before aperture 23 abuts stop 24. The upper gripper 32 stays behind until aperture 23 abuts stop 24, as a result of which the lead frame can position itself in lower mould 72, as shown diagrammatically in FIG. 7. The upper side of the groove 23 comes to bear against stop 24 when approximately half of the downward stroke performed by upper mould 70 has taken place. The grippers have now brought the lead frame into the correct position in the lower mould 72.
In this arrangement, means are present in the upper and/or lower mould to accommodate the gripper fingers 36. When the mould is being closed, the gripper fingers are free and lead frame 19 is brought into position by thecentring means (not shown). Subsequently, material is forced into the mouldcavity, as will be explained in more detail below. At that stage, the degate plate 37 is not located between the mould halves 70 and 72, i.e. inFIG. 7 it has been moved from the area of the parting line between the mould halves by the drive cylinders 31. After the material has been introduced into lead frame 19, the upper mould half 70 moves upwards again, the now encapsulated part remaining in the mould cavity of the lower mould 72. During this upward stroke, degate plate 37 moves into the position, shown in FIG. 7, between the upper mould half 70 and the lower mould half 72. Shortly before the carriage 21 is taken along by stop 34, the cylinders 27 and 35 retract so that the grippers engage on the lead frame. The cylinder 26 is driven outwards in such a way that it pulls on carriage 21. Cylinder 53 which controls stop 24 is driven outwards in the same way. Cylinder 26 thereby prevents cylinder 53 from moving upwards. This state is maintained during the first half of the opening stroke. The grippers retain their grip on the lead frame.
During the second half of the opening stroke, the carriage 21 is taken along upwards by the stops 34. Stop 24 and thus the ejection mechanism 54 follow the upper side of aperture 23 because the stops 34 override the action of the cylinder 26.
Thus the closed grippers 32 and 33 and the ejection mechanism 54 travel upwards in a synchronous manner via stop 24, and the sprue remnants are broken off the product and held in the lower mould 72. As a result of breaking off the sprue at the moulding temperature, the bond with the leadframe is relatively weak, so that a perfect finish can be obtained using relatively little force and without risk of damage to the lead frame or the capsule of the integrated circuit.
Subsequently, the arms 28 and 29 move away from the supporting plate 20 andmove along upwards with the upper mould 70, the lead frame being gripped bythe grippers. At the end of the movement stroke of the upper mould, the vertical conveying of the lead frame 19 is repeated in the manner described above and the encapsulated part in FIG. 3 is moved one position to the right.
The device for introducing plastic material under pressure into the mould cavity will be described in more detail with reference to FIG. 2 and FIG. 6. This device comprises a carriage 79, which carriage 79 is guided slidably in tie bars 78. Motor 75 is connected to the stationary part of the device and drives gearboxes 73 via transmission 74 and rod 67. Gearbox73 in turn drives lead screw 77 with which carriage 79 can be moved upwardsand downwards (not shown in more detail). The motor 75 is of such design that it regulates the movement of the plunger over its entire speed range in a controlled manner.
FIG. 6 shows that carriage 79 comprises a first support 82 and a second support 81. The lead screw 77 acts on the first support 82. The drawing shows that the second support 81 is fitted around the first support. Bores93 are provided in the first support 82, which bores accommodate the balls 91 loaded with springs 92, which balls drop into corresponding bores 94 ofthe second support 81. In addition, a piston-cylinder assembly 88, 89 is attached to the second support 81, while a bore 90 has been provided in first support 82. Piston-cylinder assembly 88, 89 (i.e. locking means 85) can be controlled by means of air hoses connected thereto, which air hosesare attached to a control device (not shown in more detail). An air cylinder 86 is also fitted on second support 81, the reciprocating part ofwhich cylinder acts on a lever arm 87 which acts, via a substantial lever transmission, on thrust rod 96 which in turn acts on press plunger rod 95 which is accommodated in lower mould 72 containing a heater 71 (not shown in more detail).
FIG. 7 diagrammatically shows a part of the upper and lower mould and indicates more clearly that pressure sensor 68 is connected to the comparing means 45 where the desired value for the present product is stored. Comparing means 45 act on control means 46 which in turn act on air cylinder 86.
The part of the device described above works as follows:
After the upper mould 70 has been closed onto the lower mould 72, a lead frame containing an integrated circuit having been accommodated in the mould cavity and a plastic material having been introduced in bore 69, said plastic material is rendered fluid by the heater 71 and the press force. As a result of driving the motor 75, the first and second support, i.e. carriage 79, move upwards and air cylinder 86 is in the extended activated position. By variation of the height of the pallets, the vertical position of 95 and 96 will also vary. As a result, the position of 86 will also be able to vary in the idling phase. The extreme positionsare indicated by dotted lines and broken lines, which position is always unknown. Under these conditions, the plunger rod 95 will travel the relatively long transport path at a relatively low pressure. In order to prevent damage to the connection between the integrated circuit and the lead frame, it is important that the fluid flow should not become too large during this first phase. During the upward movement, the locking means 85 are in the unlocked position, i.e. the piston 88 is outside the aperture 90. If, during this upward movement, the pressure should, for anyreason, exceed a set threshold value which is much lower than the final moulding pressure, but higher than the normal filling pressure, the force with which springs 92 force balls 91 into bore 94 will be overcome as soonas that set value is exceeded. In this case, the first support 82 continuesits movement whereas the second support 81 stays behind. Moreover, at the same time, the air supply to the locking means 85 and air cylinder 86 is interrupted so that these can no longer be operated. An overload protection of this kind has the advantage that an on/off state is provided. That is to say, the protection system is either active or inactive and if it is inactive, it has no effect on the overall functioning of the device. In addition, the protection system can easily be replaced.
If protection is not required, pistion 88 will be moved out of cylinder 89 when the end of the transport or transfer stroke is reached, i.e. the locking means 85 interlock the first and second support, as a result of which the securing means 84, consisting of the spring-loaded balls, are not activated when a given pressure is exceeded. Furthermore, motor 75 is switched off. Subsequently the much higher final pressure has to be generated, which is achieved by means of air cylinder 86. Since the plastic is essentially incompressible and there is still a small amount ofgas present, the generation of the final moulding pressure may be regarded as a static process. The generation of the final moulding pressure can be achieved independently of the position of the air cylinder 86. The position of arm 87 is dependent on the amount of plastic introduced. During application of the pressure for hardening, there is essentially no movement of the arm 87. This relatively high moulding pressure may be generated by a combination of the air cylinder 86 and the lever ratio of lever 87. This force is sufficient as the final pressure and is independent of the securing means 84. This is contrary to the state of theart where various spring constructions are used and the spring force has tobe overcome to apply the final pressure, as a result of which it is not possible to determine the final pressure in an accurately controlled manner. The pressure is measured constantly with the aid of the sensor 68 which is located in the upper mould (FIG. 7). The signal originating from this sensor is compared in comparing means 45 with the desired value stored in the memory of said means. In dependence on the outcome of this comparison, the control means 46 are operated to supply a higher, lower orunchanged pressure to the air cylinder. Said control may be carried out by electronic means as well as by completely pneumatic means.
It is also evident from FIG. 6 that the plunger comprises a plunger rod 95 and a thrust rod 96. Construction of the plunger in several parts means that, when the press plunger rod 95 is damaged, only this part and not thethrust rod in the carriage 79 needs to be replaced. Said construction and the replacing may be effected with the aid of a simple securing construction, as shown in FIG. 6. Supplying the pressure in two stages by two separate means gives the advantage that very effective means can be constructed for protection at low pressure, while the high-pressure mechanism can be of relatively simple construction. It is obvious that these two separate movements can be achieved by other means. Thus it is possible to effect the first part of the stroke by means of an air cylinder which applies a relatively controlled speed to the plunger rod 95. | A moulding press for a moulding device which comprises two mould halves movable relative to each other. The mould halves are connected by a pair of spaced joint linkages located opposite one another. Each joint linkage includes two pivotable arms which are connected in a hinge-like manner to each other and to a respective first and second plate. Control arms engage the joint linkages and are movably coupled to a control element. Movement of the control element will result in link motion of the control arms and cause movement of the mould halves toward each other or away from each other. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of application Ser. No. 11/069,196, U.S. Pat. No. 7,310,885, filed Feb. 28, 2005, which claims priority from U.S. Provisional Patent Application No. 60/550,955, filed Mar. 4, 2004. The entire disclosure of each of those applications is incorporated herein by reference for all purposes.
FIELD OF THE INVENTION
This invention relates to fabrics.
BACKGROUND OF THE INVENTION
Accurate measuring, marking, and cutting of fabric is important for many applications, including upholstery of furniture and the fabrication of garments, draperies linens and quilts. Factors which need to be considered include the grain of the fabric (lines parallel to the selvedge being referred to as lengthwise straight of grain, and lines at right angles to the selvedge being referred to as crosswise straight of grain), and, in appropriate fabrics, the position and repeat of decorative patterns, and the up-down direction, particularly the nap direction.
Modern garment cutting patterns are generally supplied with instructions, e.g. directional arrows on the pattern, how the cutting pattern should be positioned on the fabric, for example relative to the straight of grain. In present practice, in order to identify the straight of grain at any point on a conventional fabric, one must either reference the selvedge, and measure and mark the straight of grain at that point, or, if there is no selvedge, find another way of determining the straight-of-grain. Identification of other fabric characteristics, e.g. a nap or lay direction, or the position and repeat of a decorative pattern, similarly requires careful and repetitive work. As a result, a significant percentage of sewn items arrive on the market with visible problems resulting from failure to correctly account for fabric characteristics such as grain, nap, decorative pattern and repeat of decorative pattern.
U.S. Pat. No. 4,869,726 (Linda et al) and U.S. Pat. No. 6,839,971 (Schafer et al) describe attempts to mitigate the problems outlined above.
SUMMARY OF THE INVENTION
This invention relates to a fabric having a procedure map thereon, the procedure map comprising at least one set of machine-make markings which identifies one or more of certain fabric characteristics, namely lengthwise straight of grain, crosswise straight of grain, true bias, position of a decorative pattern, repeat of a decorative pattern, up-down direction (e.g. nap direction), fabric width measured perpendicular to a selvedge, and fabric length measured parallel to a selvedge.
In a first preferred aspect, this invention provides a roll of woven fabric, the fabric having two selvedges and a procedure map thereon, the procedure map comprising at least one set of machine-made markings which
(a) is at many points across the breadth and throughout the length of the fabric, (b) identifies at least one characteristic of the fabric, said at least one characteristic being selected from the group consisting of lengthwise straight of grain, crosswise straight of grain, true bias, position of a decorative pattern, repeat of a decorative pattern, up-down direction, fabric width measured perpendicular to a selvedge, and fabric length measured parallel to a selvedge, (c) directly contacts fibers of the fabric, and (d) is not part of a decorative pattern.
In a second preferred aspect, this invention provides a method of producing a roll of woven fabric according to the first aspect of the invention, the method comprising the steps of
(A) using a machine to impart the procedure map to a run of the fabric; and (B) after step (A), rolling up the run of fabric having the procedure map thereon.
In one embodiment of the second preferred aspect of the invention, the procedure map is imparted to the fabric as part of a continuous process which includes weaving the fabric. In one example of such an embodiment, the procedure map is woven into the fabric at the same time as the fabric is being woven. In another example of such an embodiment, the fabric is woven and the procedure map is imparted to the woven fabric immediately thereafter. In another embodiment of the second preferred aspect of invention, the run of fabric is provided by unrolling an existing roll of fabric.
In a third preferred aspect, this invention provides a method of detecting a characteristic of a fabric, the method comprising
(A) providing a roll of fabric according to the first preferred aspect of the invention; (B) unrolling a run of fabric from the roll; and (C) inspecting the run of fabric with a machine which detects one or more of said at least one set of machine-made markings.
In one embodiment of the third preferred aspect of the invention, the method further comprises, simultaneously with step (C), or after step (C),
(D) using a machine to cut a relatively small piece of fabric from the run of fabric, the cutting being carried out according to a cutting pattern which is referenced to the procedure map on the run of fabric.
In a fourth preferred aspect, this invention provides a method of cutting a length of fabric from a roll of fabric, the fabric
(a) being a woven fabric having two selvedges, and (b) having on it a procedure map comprising at least one set of machine-made markings which (i) are on one of the selvedges, (ii) identify fabric length along the selvedge, and (iii) are sequentially numbered; the method comprising cutting the length of fabric from the roll of fabric according to a cutting pattern which is referenced to the sequentially numbered markings.
In a fifth preferred aspect, this invention provides a fabric which has a procedure map thereon, the procedure map comprising at least one set of machine-made markings which
(a) is at many points across the breadth and throughout the length of the fabric, (b) identifies at least one characteristic of the fabric, said at least one characteristic being selected from the group consisting of lengthwise straight of grain, crosswise straight of grain, true bias, position of a decorative pattern, repeat of a decorative pattern, up-down direction, fabric width measured perpendicular to a selvedge, and fabric length measured parallel to a selvedge, (b) directly contacts fibers of the fabric, (c) is not part of a decorative pattern;
said at least one set of machine-made markings comprising a set of markings selected from the group consisting of
(1) a set of markings which are invisible to the naked eye, (2) a set of markings which can be removed by washing, (3) a set of markings which comprise magnetic or magnetized threads, (4) a set of markings comprising a pigment or thread visible only under ultraviolet light, (5) a set of lengthwise straight of grain markings which are equally spaced from each other, (6) a set of crosswise straight of grain markings which are equally spaced from each other, (7) on a fabric having a bias, a set of markings which identifies the true bias of the fabric, (8) on a fabric having an up-down direction, a set of markings which identifies the up-down direction of the fabric, (9) on a fabric having a decorative pattern, a set of markings which identifies the position and/or the repeat of the decorative pattern, (10) on a fabric having two selvedges, a set of lengthwise straight of grain markings which identify fabric widths perpendicular to a selvedge, at least one of the markings identifying a position halfway across the width, or a position quarter-way across the width or a position one third-way across the width, and (11) on a fabric having two selvedges, a set of markings which (i) are on at least one of the selvedges, (ii) identify fabric length along one of the selvedges, and (iii) are sequentially numbered.
In preferred embodiments, this invention can provide one or more of the following functions:
(a) a reduction in the time involved in determining the straight-of-grain at virtually any point on the fabric; (b) a reduction in waste in the production of garments, draperies, linens, upholstery, quilts, and other sewn goods by providing immediate reference for the straight-of-grain and other orientation marks; (c) the production of a higher quality finished product through precision grain orientation; (d) a reduction in the need for hand measuring, and marking, by providing pre-measured markings already on the fabric, thus saving time; (e) providing a means for accurate bias orientation consistently available to assure the proper drape by allowing the adjustment of the degree of bias desired; (f) manual or automatic detection of straight-of-grain and other markings, depending on the use of the fabric; (g) provision of an accurate cutting line through a grid of lengthwise and crosswise straight-of-grain lines, thus saving time at the retail level, and helping customers visually estimate yardage; (h) increasing the efficiency of fabric use by enabling the use of fabric not having a selvedge; (i) determination of the lay or nap orientation in the manual or automatic use of fabric via directional markings to benefit those working with fabric such as velour or velvet and the like which have a nap orientation, or those fabrics with an unidirectional decorative pattern; and (j) enabling the scaling up and down of a grid of lengthwise and crosswise straight of grain markings to aid in the processes of quilting, by either enlarging or narrowing the distance between markings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 show a fabric having a procedure map thereon, with FIG. 1 showing one part of the procedure map and FIG. 2 showing the other part of the procedure map.
DETAILED DESCRIPTION OF THE INVENTION
The form of the various markings can be the same or different. For example, each of the markings in a particular set of markings (for example the straight of grain markings) can be a continuous line or a line which is discontinuous (e.g. a line made up of dashes or dots); or can be a number of arrows (e.g. to identify the nap or lay direction, in which case the precise positioning of the arrows may not be important); or can be a number of aligned symbols (e.g. to identify the position and/or repeat of a decorative pattern). In preferred embodiments, the markings directly contact fibers of the fabric. In some embodiments, the markings are at many points across the breadth and throughout the length of the fabric and/or cover substantially the whole of the fabric. In some embodiments, the straight of grain markings are equally spaced from each other. The fabric optionally comprises a decorative pattern. When the fabric comprises a decorative pattern, the markings are not part of the decorative pattern.
Specific examples of sets of markings include one or more of the following:
(1) a set of markings which are invisible to the naked eye, (2) a set of markings which can be removed by washing, (3) a set of markings which comprise magnetic or magnetized threads, (4) a set of markings comprising a pigment or thread visible only under ultraviolet light, (5) a set of lengthwise straight of grain markings which are equally spaced from each other, (6) a set of crosswise straight of grain markings which are equally spaced from each other, (7) on a fabric having a bias, a set of markings which identifies the true bias of the fabric, (8) on a fabric having an up-down direction, a set of markings which identifies the up-down direction of the fabric, (9) on a fabric having a decorative pattern, a set of markings which identifies the position and/or the repeat of the decorative pattern, (10) on a fabric having two selvedges, a set of lengthwise straight of grain markings which identify fabric widths perpendicular to a selvedge, at least one of the markings identifying a position halfway across the width, or a position quarter-way across the width or a position one third-way across the width, and (11) on a fabric having two selvedges, a set of markings which (i) are on at least one of the selvedges, (ii) identify fabric length along one of the selvedges, and (iii) are sequentially numbered.
For example, in some embodiments, the fabric has a first side having a decorative pattern thereon and an opposite second side, and the procedure map comprises a set of markings which (i) is visible only on the second side and (ii) identifies one or both of (a) the position of the decorative pattern, and (b) the repeat of the decorative pattern.
The markings are optionally such that they can be easily removed after they have served their purpose; for example they can be composed of an easily washable dye or a reactive dye. The markings are optionally visible only on one surface of a fabric, for example on the “back” side of the fabric, e.g. on the opposite side of a fabric comprising a decorative pattern intended to be viewed on the front side of the fabric. In some embodiments, the surface carrying the markings becomes the inside surface of a finished product, e.g. so that the markings cannot be seen in the finished product. In some embodiments, any markings on a finished product which remain visible to the naked eye are rendered invisible to the naked eye.
In some embodiments, the markings of the procedure map are visible to the naked eye (and can, therefore, also be detected by a suitable machine). In other embodiments, the markings are not visible to the naked eye, but can be detected by a suitable machine. The markings can for example be visible to the naked eye under ultraviolet light.
In some embodiments, the fabric is produced, e.g. by weaving, and the markings are imparted to the fabric, in a single continuous operation. Alternatively, the markings can be imparted to an existing fabric, e.g. a woven fabric, in a separate operation. In either case, an automated dye and marking system can optionally be used. Preferably, the result of the process is a roll of fabric having the markings throughout the length of the fabric on the roll.
In one embodiment, straight of grain markings are introduced during production of a woven fabric by including warp and/or woof yarns which can be distinguished from the other yarns of the fabric, e.g. by including yarns which are invisible to the naked eye, but detectable by a suitable machine.
Referring now to the drawings, FIGS. 1 and 2 show a bolt of fabric 10 having a selvedge 15 at each edge. FIG. 1 shows equispaced lengthwise straight of grain markings 11 which extend the whole length of fabric; equispaced crosswise straight of grain markings which extend across the whole breadth of the fabric; and bias markings 13 showing the true bias of the fabric. FIG. 2 shows markings 16 showing the lengthwise decorative pattern repeat; markings 17 showing the crosswise decorative pattern repeat; markings 18 showing premeasured widths (center, ¼ and ⅓); and yardage measurements 19 on the selvedges. | A fabric having a procedure map which enables identification, by a machine or by a person, of one or more of the fabric characteristics, e.g. the straight of grain, true bias, up-down direction, decorative pattern characteristic, distance from a selvedge or distance along a selvedge. The procedure map facilitates accurate measuring, marking, and cuffing of fabric e.g. for furniture upholstery, garments, draperies, linens and quilts. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 10/079,712, filed Feb. 20, 2002, now U.S. Pat. No. 6,645,773.
FIELD OF THE INVENTION
The present invention relates to a method of analyzing materials, and more particularly, to a method of accurately measuring the effective temperature inside a sealed container, such as a headspace vial.
BACKGROUND OF THE INVENTION
The technique of equilibrium headspace extraction involves placing a liquid or solid sample into a suitable sealed vial and allowing volatile analytes within the sample to reach equilibration in concentration between the sample matrix and the vapor above it (i.e., the headspace). A fixed volume of the vapor is then transferred to a gas chromatograph for analysis. At equilibration, the concentration of each analyte in the headspace is defined by the amount of the analyte present, the volumes of the two phases and the partition coefficient for that analyte between the two phases. The partition coefficient, which is a thermodynamic property, is highly dependent on temperature and so must be carefully controlled within the instrumentation if good analytical precision is to be achieved.
Current state-of-the-art headspace samplers, such as the model TurboMatrix Automatic Headspace Sampler distributed by PerkinElmer Instruments LLC, are designed to maintain a very stable vial temperature by making use of a large thermostatted metal oven block. However, despite the fact that stable vial temperatures can be maintained, a number of issues regarding temperature control remain.
For example, the true temperature of the vial may not be accurately measured. The electronic sensor used to monitor temperature is typically located within a heating belt that surrounds the oven block and is remote from the vial. As such, the temperature reading may not reflect the true vial temperature at all settings. Moreover, it is possible that all vial positions may not be at the same temperature.
Another issue may arise when a new (cold) vial is inserted into the oven block. In such a case, there may be a drop in temperature in one or more of the other vials which cannot be readily detected using known methods. Furthermore, known methods of temperature measurement may not take into account the fact that the vial temperature may change over time.
Another potential issue is that certain requirements, such as GLP (Good Laboratory Practices) certification standards and FDA (Food and Drug Administration) approval requirements, may require that the vial temperature be monitored and/or calibrated.
In addition, some instruments which are not state-of-the-art may be weak in the area of vial temperature control. As such, it may be desirable to evaluate the performance of such instruments using a simple method for temperature measurement.
Traditionally, a thermocouple or similar temperature-measuring probe would be inserted into the vial. However, this technique is tedious to perform, interrupts the normal operation of the instrument, and requires special tools. Moreover, taking a reading from a single point inside the vial may not truly reflect the “effective” temperature of the whole vial. Instead, it would be more desirable to make use of a suitable sample in a vial and use chromatography to determine temperature—after all, it is this process for which standardization is being attempted.
What is desired, therefore, is a method of measuring the effective temperature inside a sealed container which accurately reflects the true container temperature at all instrument settings, which takes into account temperature variations across various container positions, which measures the temperature of each container separately from other containers when a plurality of containers are used, which takes into account the fact that the container temperature may change over time, which allows for temperature calibration, which can be used to evaluate the temperature control performance of an instrument, which is easy to perform, which does not interrupt the normal operation of the instrument, which does not require special tools, and which uses chromatography to determine temperature.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a method of measuring the effective temperature inside a sealed container which accurately reflects the true container temperature at all instrument settings.
Another object of the present invention is to provide a method of measuring the effective temperature inside a sealed container having the above characteristics and which takes into account temperature variations across various container positions.
A further object of the present invention is to provide a method of measuring the effective temperature inside a sealed container having the above characteristics and which measures the temperature of each container separately from other containers when a plurality of containers are used.
Still another object of the present invention is to provide a method of measuring the effective temperature inside a sealed container having the above characteristics and which takes into account the fact that the container temperature may change over time.
Yet a further object of the present invention is to provide a method of measuring the effective temperature inside a sealed container having the above characteristics and which allows for temperature calibration.
Still a further object of the present invention is to provide a method of measuring the effective temperature inside a sealed container having the above characteristics and which can be used to evaluate the temperature control performance of an instrument.
Still a further object of the present invention is to provide a method of measuring the effective temperature inside a sealed container having the above characteristics and which is easy to perform.
Yet another object of the present invention is to provide a method of measuring the effective temperature inside a sealed container having the above characteristics and which does not interrupt the normal operation of the instrument.
Still a further object of the present invention is to provide a method of measuring the effective temperature inside a sealed container having the above characteristics and which does not require special tools.
Yet still a further object of the present invention is to provide a method of measuring the effective temperature inside a sealed container having the above characteristics and which uses chromatography to determine temperature.
These and other objects of the present invention are achieved by provision of method of measuring the effective temperature inside a sealed container having a headspace. A liquid solvent is added to the container, and a solid compound is added to the liquid solvent to create a saturated solution. Vapor of the saturated solution is allowed to equilibrate in the headspace of the sealed container, and a volume thereof is transferred to a chromatographic column, where chromatographic readings of the equilibrated vapor are taken. A temperature within the sealed container is then calculated based upon the chromatographic readings of the equilibrated vapor, wherein the temperature calculation is based upon the concentrations of the liquid solvent and the solid compound in the equilibrated vapor.
Preferably, the chromatographic readings comprise readings of peak areas of the liquid solvent and the solid compound. Most preferably, the calculating step comprises the step of calculating a temperature within the sealed container based upon a ratio of the readings of peak areas of the liquid solvent and the solid compound.
In one preferred embodiment, the liquid solvent comprises n-dodecane and the solid compound comprises naphthalene. In another embodiment, the liquid solvent comprises n-octadecane and the solid compound comprises anthracene.
The invention and its particular features and advantages will become more apparent from the following detailed description considered with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a sealed vial for which the temperature can be measured in accordance with the present invention;
FIG. 2 is a graphical representation of the ideal vapor pressure behavior for a binary mixture according to Raoult's Law as employed by the present invention;
FIG. 3 is a graphical representation of chromatograms of a n-dodecane and naphthalene test mix thermostatted over a range of temperatures which illustrates a portion of the theory underlying the present invention;
FIG. 4 is a plot of area ratio (naphthalene/n-dodecane) versus set temperature in ° C. which illustrates a portion of the theory underlying the present invention; and
FIG. 5 is a plot of a linear relationship between the areas of naphthalene and n-dodecane which illustrates a portion of the theory underlying the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In arriving at the present invention, consideration was given to making use of temperature dependence of partition coefficients in order to determine the effective temperature within a vial. In accordance with such a method, a solution of two solutes in a suitable solvent would be prepared. The solutes and solvent would be chosen so that their partition coefficients exhibited different temperature profiles. Their relative concentrations (hence chromatographic peak sizes) would be a measure of the temperature.
However, it was found that this approach may be undesirable because it would rely on very precise control of concentrations and volumes. Moreover, the compounds would have to be chemically similar so that their relative response factors on the GC detector would be constant, and differences in partition coefficient profiles would therefore be subtle.
Consideration was also given to making use of temperature dependence of vapor pressures in order to determine the effective temperature within a vial. In accordance with this method, an excess of a suitable compound disposed in a thermostatted headspace vial would saturate the headspace with compound vapor. The concentration of the vapor at the saturation point would be proportional to the vapor pressure. Vapor pressure is dependent upon temperature and so the concentration of vapor in the headspace is temperature dependent. By choosing two compounds with different vapor pressure curves, the ratio of their concentrations (hence chromatographic peak sizes) would be a measure of temperature.
However, it was found that this approach may be undesirable because when two compounds are mixed together, there is a change to their respective vapor pressures that is concentration dependent and so results are difficult to predict.
In order to overcome the deficiencies of the prior art and to avoid the concerns expressed with respect to the approaches described above, it was decided upon to make use of temperature dependence of solubility and vapor pressure.
Referring to FIG. 1 , this method relies on the solubility of a solid compound 10 in a suitable liquid solvent. Sufficient solid 10 is added to ensure that a saturated solution 12 is produced. The saturation concentration is highly temperature dependent but should always be the same at any given temperature. This effect will also mean that the concentration of both compound vapors in the headspace 14 inside a sealed vial 16 containing the saturated solution 12 will also be predictable at any given temperature. The compound concentrations in the headspace 14 are now dependent on both liquid solubility and vapor pressure and should give an enhanced temperature effect.
In one preferred embodiment, naphthalene was chosen as the solid compound and n-dodecane was chosen as the liquid solvent. These compounds were found to be appropriate for a number reasons, such as the fact that they are both hydrocarbons and should give relative response factor reproducibility on all flame ionization detectors. Moreover, n-dodecane becomes saturated with naphthalene at concentrations of approximately 30% at ambient temperature, which simplifies the measuring process. Furthermore, the vapor pressures of pure n-dodecane and pure naphthalene are similar, they are chromatographically-friendly compounds that can be run on almost any column, and their vapor pressure curves are significantly different.
However, it should be understood that the combination of n-dodecane and naphthalene is not meant to be limiting in any way, and the use of numerous combinations of compounds with the inventive measurement method is contemplated. More specifically, experiments have shown that the use of n-dodecane and naphthalene may be limited to temperatures in the region of about 40 to 70° C. (naphthalene melts at 800° C.). For higher temperatures, other compounds, such a combination of n-octadecane and anthracene, may be used without departing from the present invention.
The general procedure employed with the present invention involves the following steps. First, a vial containing an approximately 10-90 mix of n-dodecane and naphthalene is placed into a headspace sampler and allowed to thermostat (i.e., typically for about 20 minutes) at the set temperature. Next, a suitable volume of the equilibrated headspace vapor is transferred to a chromatographic column for determination. Finally, the temperature of the headspace vial is derived from the ratio of the two peak areas, as more fully discussed below.
Theoretical Model
The vapor pressure of a component in a binary mixture may be conveniently described by Raoult's Law as:
( p 0 - p ) p 0 = x = n 2 ( n 1 + n 2 ) ( 1 )
Where:
p 0 is the vapor pressure of the compound in the mixture p is the vapor pressure of the pure compound x is the mole fraction of the compound in the mixture n 1 is the number of moles of the other compound n 2 is the number of moles of the compound being studied
FIG. 2 , which graphically illustrates the ideal vapor pressure behavior for a binary mixture according to Raoult's Law, shows how the relative vapor pressure, hence vapor phase concentration, of each component depends on the concentration of that component in the liquid mixture and the vapor pressure of the pure compound. If the vapor were to be chromatographed, then the peak area ratio for the two compounds would be dependent on both their liquid concentrations and pure vapor pressures.
The concentration of a saturated solution of naphthalene in n-dodecane is temperature dependent and may again be described by another form of Raoult's Law as:
x = n 2 ( n 1 + n 2 ) = ⅇ [ L f R ( T 0 - T T 0 · T ) ] ( 2 )
Where:
L f is the molar heat of fusion R is the gas constant T 0 is the compound freezing point absolute temperature T is the absolute temperature of the solution
The dependence of vapor pressure of a pure substance on temperature may be described by the Clapeyron-Clausius Equation as:
p = ⅇ ( L v RT + C ) ( 3 )
Where:
L v is the molar heat of vaporization C is a constant
It should be noted, however, that in practice, deviations from Equations 1, 2 and 3 may be expected because of inter-molecular forces. Therefore, these relationships should be used only for guidance.
Equations 1, 2 and 3 may be combined to give Equations 4 or 5, which relate the predicted vapor pressure, p 0 , for a component in a saturated mixture to temperature, T, as follows:
p 0 = ⅇ [ L v RT + C ] 1 - ⅇ [ L f R ( T 0 - T T 0 · T ) ] ( 4 )
or
p 0 = a · ⅇ b T 1 - c · ⅇ d T ( 5 )
Where:
a is a constant b is a constant c is a constant d is a constant
The ratio of the observed vapor pressures would be:
p 0 p 0 ′ = a · ⅇ b T a ′ · ⅇ b ′ T · 1 - c ′ · ⅇ d ′ T 1 - c · ⅇ d T ( 6 )
Where:
p 0 ′ is the predicted vapor pressure for the second compound a′ is a constant relating to the second compound b′ is a constant relating to the second compound c′ is a constant relating to the second compound d′ is a constant relating to the second compound
Equation 6 may be reduced to the final form:
p 0 p 0 ′ = a · ⅇ b T - c · ⅇ d T 1 - f · ⅇ g T ( 7 )
Where:
a is a constant b is a constant c is a constant d is a constant f is a constant g is a constant
Because compound concentration and hence chromatographic peak area is proportional to the vapor pressure, Equation 7 also applies to the peak area ratio, as described more fully below.
FIG. 3 shows chromatograms of the n-dodecane and naphthalene test mix thermostatted over a range of temperatures. The experimental conditions are given in Table 1. FIG. 4 shows a plot of area ratio (naphthalene/n-dodecane to give a positive slope) versus set temperature in ° C. The non-smoothness in the plot may be caused by errors in the measurement or may be a true indication of varying vial temperature (readings were taken with different vials, in different carousel positions and at different times).
TABLE 1
Experimental Conditions
Chromatograph
AutoSystem XL (PerkinElmer Instruments)
Column
30 m × 0.32 mm × 1.0 μm PE-5
(PerkinElmer Instruments)
Oven
200° C. Isothermal
Carrier Gas
Helium at 12.5 psig with PPC
Interface
Split injector at 250° C. with low dead volume liner
Detector
FID at 300° C., range ×1, attenuation ×4
Headspace
HS40 XL (PerkinElmer Instruments)
Thermostat Temp.
44° C. to 72° C. in 4° increments
Thermostat Time
20 min.
Pressure
15 psig with PPC
Press Time
1 min.
Inject Time
0.02 min.
Withdrawal Time
0.5 min.
Sample
180 mg naphthalene and 20 mg n-dodecane
in 22-ml vial
By inverting the area ratios, the data seems to approximate to the following simple linear relationship, which is also plotted in FIG. 5 :
Area
Dodecane
Area
Naphthalene
=
2.094
-
0.02313
·
T
(
8
)
Thus, solving Equation 8 for T, the temperature of the vial can be determined by employing a chromatograph to measure the peak areas for n-dodecane and naphthalene.
The present invention, therefore, provides a method of measuring the effective temperature inside a sealed container which accurately reflects the true container temperature at all instrument settings, which takes into account temperature variations across various container positions, which measures the temperature of each container separately from other containers when a plurality of containers are used, which takes into account the fact that the container temperature may change over time, which allows for temperature calibration, which can be used to evaluate the temperature control performance of an instrument, which is easy to perform, which does not interrupt the normal operation of the instrument, which does not require special tools, and which uses chromatography to determine temperature.
Although the invention has been described with reference to a particular arrangement of parts, features and the like, these are not intended to exhaust all possible arrangements or features, and indeed many other modifications and variations will be ascertainable to those of skill in the art. | A method of measuring the effective temperature inside a sealed container having a headspace is provided. A liquid solvent is added to the container, and a solid compound is added to the liquid solvent to create a saturated solution. Vapor of the saturated solution is allowed to equilibrate in the headspace of the sealed container, and a volume thereof is transferred to a chromatographic column, where chromatographic readings of the equilibrated vapor are taken. A temperature within the sealed container is then calculated based upon the chromatographic readings of the equilibrated vapor, wherein the temperature calculation is based upon the concentrations of the liquid solvent and the solid compound in the equilibrated vapor. | 8 |
This application claims benefit of application 60/367,712 filed Mar. 28, 2002.
FIELD OF THE INVENTION
The present invention refers to a wetlaid or foam formed hydraulically entangled nonwoven material containing at least 30%, by weight, pulp fibers and at least 20%, by weight, man-made fibers. It further refers to a method of making such a material.
BACKGROUND OF THE INVENTION
Hydroentangling or spunlacing is a technique introduced during the 1970'ies, see e g CA patent no. 841 938. The method involves forming a fiber web, which is either drylaid or wetlaid, after which the fibers are entangled by means of very fine water jets under high pressure. Several rows of water jets are directed against the fiber, web which is supported by a movable wire. The entangled fiber web is then dried. The fibers that are used in the material can be natural fibers, especially cellulosic pulp fibers, man-made staple fibers, which may be synthetic, e g polyester, polyamide, polyethylene, polypropylene, or regenerated staple fibers, eg viscose, rayon, lyocell or the like, and mixtures of pulp fibers and staple fibers. Spunlace materials can be produced in high quality to a reasonable cost and they possess a high absorption capacity. They can e g be used as wiping material for household or industrial use, as disposable materials in medical care and in hygiene purposes etc.
Through e g EP-B-0 333 211 and EP-B-0 333 228 it is known to hydroentangle a fibrous mixture in which one of the fiber components is continuous filaments in the form of meltblown fibers.
In WO 96/02701 there is disclosed hydroentangling of a foam formed fibrous web. The fibers included in the fibrous web can be pulp fibers and other natural fibers and man-made fibers.
During the hydroentanglement the fiber web is supported either by a wire or a perforated, cylindrical metal drum. An example of a hydroentanglement unit of this kind is disclosed in for example EP-A-0 223 614. However, supporting members in the form of wires of the type utilised in connection with paper production is the most frequently occurring type as for example is shown in EP-A-0 483 816. One disadvantage with using wires of this type is that the fiber web, during the hydroentanglement, is exerted to a strong action by the water jets and will penetrate into and get caught between the wire threads. It may then be difficult to separate the final product from the wire.
WO 01/88261 discloses the use of a moulded, close-meshed screen of thermoplastic material as supporting member during hydroentanglement of a fibrous web. The removal of the final product from such screen is simplified as compared to a wire.
When making a nonwoven material, especially a material that is intended to be used as a wiping material, there a many properties that are important, such as absorptive capacity, absorption speed, wet strength, softness, drapability, low linting, high cleaning ability etc. It is however difficult to combine all these properties in one and the same material. It is for example possible to make cloth like, soft, strong and low linting hydroentangled nonwoven material by using 100% synthetic fibers. However the absorption properties of such a material will be low. Materials containing a high amount of pulp fibers have a high absorptive capacity, but a poor wet strength and high linting. The wet strength and linting properties can be improved by the addition of chemicals, such as wet strength agents and binders.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a hydroentangled nonwoven material that combines properties like wet strength, absorptive capacity, softness and drapability. This has been achieved by a wetlaid or foam formed hydraulically entangled nonwoven material containing at least 30%, by weight, pulp fibers and at least 20%, by weight, man-made fibers or filaments, said nonwoven material having a basis weight variation in a non-random pattern in that it comprises a plurality of higher basis weight cushions protruding from one major surface of said material, said cushions as a main component comprises pulp fibers and are surrounded by a lower basis weight network which contains a relatively higher amount of man-made fibers or filaments as compared to the cushions.
It is believed that this specific structure provides:
a cloth like appearance of the material; high strength due to the network of the man-made fibers; high absorptive capacity provided by the high pulp content cushions and the three-dimensional structure formed by these; high softness and drapability due to the plurality of bending indications provided by the network pattern.
The opposite major surface of the material is preferably substantially smooth. This will improve the capability of the material to wipe a surface dry from any remaining liquid.
The material preferably contains 40%, and more preferably at least 50%, by weight, pulp fibers. Preferably it contains at least 30%, and more preferably at least 40%, by weight, man-made fibers or filaments. The man-made fibers are in one embodiment staple fibers of a length between 6 mm and 25 mm.
It is preferred that the material has an absorptive capacity of at least 5 g/g water.
It is further preferred that the material has an absorption speed, WAT, in MD of no more than 1.5 s/m, preferably no more than 1 s/m, and in CD of no more than 2.5 s/m, preferably no more than 2 s/m.
In a preferred embodiment the cushions have a length and width between 0.2 and 4 mm, preferably between 0.5 and 2 mm. It is further preferred that the distance between the adjacent cushions is between 0.2 and 4 mm, preferably between 0.5 and 2 mm.
The present invention also refers to a method of producing a nonwoven material as stated above, said method comprises wetlaying or foamforming a fiber dispersion to form a fibrous web containing at least 30%, by weight, pulp fibers and at least 20%, by weight, man-made fibers or filaments, calculated on the total weight of the fibers in said fibrous web, and hydroentangling the fibrous web followed by subsequent dewatering and drying, wherein at least part of the hydroentangling step is performed on a foraminous support member in the form of a moulded, close-meshed screen of a thermoplastic material, said screen having apertures of the cross-dimensional size 0.2-4 mm the and the distance between the apertures being between 0.2-4 mm.
Preferably the apertures in said screen are of the size 0.5-2 mm and the distance between the apertures is between 0.5-2 mm.
In one embodiment the fibrous web is formed on a formation wire and is subjected to a first hydroentangling while supported on said formation wire, and is then transferred to said moulded, close-meshed screen where it is subjected to a further hydroentangling.
Preferably said further hydroentangling is performed from the opposite side of the fibrous web as compared to the first hydroentangling.
In a preferred embodiment the web is after dewatering subjected to non-compacting drying, such as through-air-drying, IR drying or the like. In order to maintain bulk and absorbency of the material preferably no pressing of the fibrous web takes place during dewatering and drying.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will below be described with reference to some embodiments described in the accompanying drawings.
FIG. 1 is a schematic view of a device for hydroentangling a fibrous web.
FIG. 2 shows a schematic perspective view, on an enlarged scale, of a screen used for supporting the fibrous web during the hydroentangling.
FIG. 3 is a picture taken of a nonwoven material according to the invention on a magnification of about 30 times.
FIGS. 4 and 5 are electron microscope (SEM) pictures of a nonwoven material according to the invention.
DESCRIPTION OF EMBODIMENTS
The device, which schematically is shown in FIG. 1 , for manufacturing a so-called hydroentangled or spunlaced material, comprises a vessel 10 , e g a pulper, in which a wet or foamed fiber dispersion is prepared, which via a headbox 11 is distributed on a foraminous support member 12 . This foraminous support member 12 is preferably a wire of any conventional kind used in papermaking industry and which is suited for formation and for a first hydroentangling step to intertwine at least the man-made fibers present in the web. The formed fibrous web 13 is then subjected to hydroentanglement from several rows of nozzles 14 , from which water jets at a very high pressure are directed towards a fibrous web, while this is supported by the foraminous support member 12 . The fibrous web is drained over suction boxes 15 . Thereby, the water jets accomplish an entanglement of the fibrous web, i.e. an intertwining of the fibers. Appropriate pressures in the entanglement nozzles are adapted to the fibrous material, grammage of the fibrous web, etc. The water from the entanglement nozzles 14 is removed via the suction boxes 15 and is pumped to a water purification plant, and is then re-circulated to the entangling stations.
For a further description of the hydroentanglement or, as it is also called, spunlacing technology, reference is made e.g. to the above-mentioned CA patent No. 841 938.
The fibrous web 13 is either wet-laid or foam-formed. In a wet-laid process the fibers are dispersed in a liquid, normally water, in a similar way as in a papermaking process and the dilute fiber dispersion is deposited on the foraminous support member where it is dewatered to form a continuous web-like material. The fiber dispersion may be diluted to any consistency that is typically used in conventional papermaking process. A foam forming process is a variant of a wet-laying process and a surfactant is added to the fiber dispersion, which is foamed, and the foamed fiber dispersion is deposited on the foraminous support. A very even fiber distribution is achieved in a foam forming process and it is also possible to use longer fibers than in a conventional wet-laying process.
The fibers used to form the fiber dispersion is a mixture of cellulosic pulp fibers and man-made staple fibers or man-made filaments. The pulp fibers can be selected from any type of pulp and blends thereof. Preferably the pulp is characterized by being entirely natural cellulosic fibers and can include cotton as well as wood fibers. Preferred pulp fibers are softwood papermaking pulp, although hardwood pulp and non-wood pulp, such as hemp and sisal may be used. The length of pulp fibers may vary from less than 1 mm for hardwood pulp and recycled pulp, to up to 6 mm for certain types of softwood pulp. The fiber dispersion should contain at least 30% by weight, calculated on the total fiber weight, pulp fibers.
The man-made fibers may be any suitable synthetic fibers or regenerated cellulosic fibers. Examples of commonly used synthetic fibers are polyester, polyethylene, polypropylene, polyamide, polylactides and/or copolymers thereof. Examples of regenerated fibers are rayon, viscose, lyocell. The man-made fibers may be in the form of staple length fibers. A preferred length of staple fibers used in a wetlaying or foam forming process is between 6 mm and 25 mm. The fineness of the fibers can vary between 0.3 dtex and 6 dtex. The fibers dispersion should contain at least 20% by weight, calculated on the total fiber weight, man-made fibers.
The man-made filaments are preferably spunlaid or meltblown filaments of suitable thermoplastic polymers, such as polyethylene, polypropylene, polyamides, polyesters and polylactides. Copolymers of these polymers may of course also be used, as well as natural polymers with thermoplastic properties.
The web 13 is turned 180° and transferred to a second foraminous support member 16 , which in a preferred embodiment is constituted of a moulded, close-meshed plastic screen, as disclosed in WO 01/88261. The plastic screen according to the invention can consist of one layer, as shown in FIG. 2 , or of two or several layers applied on top of each other. Possibly, the screen can be reinforced with reinforcement wires 17 which extend in the intended machine direction of the plastic screen/entanglement wire 16 . Reinforcement wires can be arranged also in the transverse direction of the screen, or both in the longitudinal and the transverse direction. The production of the plastic screen can take place e.g. in the way described in U.S. Pat. No. 4,740,409. The plastic screen is provided with a plurality of apertures 18 , which will be described in greater detail below.
The web is hydroentangled a second time from several rows of nozzles 19 while supported on the plastic screen member 16 . The second hydroentanglement takes place from the opposite side of the fibrous web 13 as compared to the first hydroentanglement. The fibrous web is drained over suction boxes 20 .
Further dewatering of the fibrous web may take place over suction boxes 21 , while the web 13 has been transferred to a dewatering wire 22 . This further dewatering may optionally take place while the fibrous web is still supported by the plastic screen member 16 .
The entangled material is then brought to a drying station 23 for drying before the finished material is reeled up and converted. Drying can be performed by blowing hot air through the fibrous web, by IR dryers or other non-compacting drying technique. Preferably no pressing of the fibrous web takes place during dewatering and drying thereof. The material may before conversion be exerted to different kind of treatments, such as corona or plasma treatment 24 , treatment with chemicals of any desired kind etc. Corona or plasma treatment is preferably made after drying while chemicals may be added either to the fiber dispersion or after dewatering of the web by spraying printing or the like.
In the embodiments shown in FIG. 2 , the apertures 18 in the screen 16 exhibit a rectangular shape, but it is evident that this shape can be varied to any geometrical shape. The meshes in the screen suitably exhibit an aperture size within the interval 0.2-4 mm, preferably 0.5-2 mm. The aperture size is herein defined as the size between opposite side edges or corners. The apertures are either of substantially the same size or of different sizes, and are either uniformly distributed across the screen or arranged to form patterns with alternating groups of apertures of different sizes. Also the cross-sectional shape of the apertures in the z-direction can be varied, and can be e.g. substantially rectangular, alternatively convex or concave. The distance between the apertures may vary between 0.2-4 mm, preferably between 0.5 and 2 mm. The distance between the apertures is defined as the shortest distance between adjacent apertures.
In case the screen consists of two or several layers arranged on top of each other, the different layers can exhibit different aperture sizes among themselves, e.g. with larger apertures in an upper layer and smaller apertures in a lower layer. This is shown in WO 01/88261. In this way, fibers can penetrate down into the larger apertures in the upper layer but be retained by the lower layer during the entanglement.
The surface, which is intended to support the fibrous web, can be substantially smooth, or exhibit a three-dimensional structure in order to impart a corresponding three-dimensional structure to the hydroentangled material.
Other foraminous supports such as wires and other types of screens may also be used, which have apertures of the size stated above.
When hydroentangling the fiber dispersion through the apertured screen 16 the shorter pulp fibers, which are more easily mobile, will to a higher extent follow the water that is drained through the apertures 18 and be accumulated in said apertures, while the longer man-made fibers which are less mobile and more easily intertwined by the water jets, will to a higher extent stay in place on the screen 16 and build up a strong fibrous network.
This will result in a nonwoven material having a plurality of cushions 25 protruding from one major surface of the material, said cushions as a main component comprise pulp fibers 26 that during drainage have accumulated in the apertures 18 of the screen 16 . The term “main component” in this respect means that more than 50% by weight, preferably more than 60% by weight and more preferably more than 70% by weight of the fibers present in said cushions are pulp fibers 26 . A minor proportion of the fibers in the cushions 16 will of course be man-made fibers.
The pulp fiber cushions 25 are surrounded by a network 27 , which contains a relatively higher amount of man-made fibers 28 as compared to the cushions 25 . In a preferred embodiment more than 50% by weight, preferably more than 60% by weight and more preferably more than 70% by weight of the fibers present in said network are man-made fibers 28 . The longer man-made fibers 28 are more easily entangled and will intertwine with each other to form a strong continuous network 27 which will impart high strength to the material. The pulp fiber cushions contribute to the absorbency of the material. This is shown in FIGS. 4 and 5 showing SEM-pictures of a material according to the invention, and in which the accumulation of pulp fibers 26 to form the cushions 25 can be seen. It is further seen how these cushions 25 are surrounded by a network. This is also seen from the light microscope picture in FIG. 3 .
In order to provide a pronounced cushion effect at least 30% by weight and preferably at least 40% of the fibers in the material should be pulp fibers and in order to provide a strong network of man-made intertwined fibers at least 20% by weight and preferably at least 30% by weight of the fibers in the material should be man-made fibers.
The length and width dimensions of the cushions 25 will correspond to the size of the apertures 18 of the screen 16 and the width of the network strands 27 between the cushions 25 will correspond to the distance between adjacent apertures 18 of the screen 16 .
The opposite major surface of the material is preferably substantially smooth as compared to the first surface having a pronounced three-dimensional structure provided by the plurality of protruding cushions. This gives the material a two-sidedness with one side that is more “rough” and adapted to remove and capture liquids, viscous fluids and solid particles from a surface. The opposite smooth surface is adapted to wipe a surface dry from liquid.
Tests have been performed on materials produced as described below.
A foamformed fiber dispersion was made from water, surfactant and a mixture of pulp fibers and man-made staple length fibers. A surfactant was added to the water in an amount of 0.03% by weight. The foamed fiber dispersion was laid on a wire and the formation was made at an air content in the foam of 30-50% by volume. The fibrous web was hydroentangled on the same wire used for formation. The web was then transferred to a moulded, close-meshed plastic screen as disclosed above, having holes of the size 0.89×0.84 mm and a distance between the holes of 0.46 mm. The web was then hydroentangled from the opposite side. The main part of the hydroentangling was made on the first wire in order to give maximum strength to the material. The total energy supply at the hydroentangling was about 200 kWh/ton material.
The fibrous web was then dewatered by vacuum suction boxes and dried by so called through-air-drying (TAD).
The fibers used for forming the fibrous web had the following composition:
Ex. 1:
25 wt % polyester (PET) from KoSa, 1.7 dtex/19 mm;
17 wt % polypropylene (PP) from Fibervisions, 1.7 dtex/18 mm;
58 wt % bleached sulphate pulp fibers from Korsnäs,
Vigor Fluff.
Ex. 2:
40 wt % polypropylene (PP) from Fibervisions, 1.7 dtex/18 mm;
50 wt % bleached sulphate pulp fibers from Korsnäs,
Vigor Fluff.
As reference material was used a nonwoven wiping material produced by SCA Hygiene Products AB under the trade mark E-Tork Strong™. It is made by wet forming a fiber mixture and hydroentangling thereof. However there is not used any moulded, close-meshed plastic screen, but the hydroentangling process is performed on a conventional papermaking wire. The material does not have the patterned three-dimensional structure as claimed by the present invention, but a more uniform fiber distribution. The fiber composition in the reference material was as follows:
Ref.:
25 wt % polyester (PET) from KoSa, 1.7 dtex/19 mm;
17 wt % polypropylene (PP) from Steen, 1.7 dtex/18 mm;
58 wt % bleached sulphate pulp fibers from Korsnäs, Vigor Fluff.
Thus the fiber composition is the same as for Ex. 1 except that the PP fibers are from another manufacturer.
Evaluations concerning strength properties both in dry and wet conditions, absorbency, wicking rate were performed and gave the results presented in Table 1 below:
TABLE 1
Ex. 1
Ex. 2
Ref.
Grammage
g/m 2
76.4
88.0
83.0
Thickness
μm
623
641
357
Bulk 2 kPa
cm 3 /g
8.2
7.3
4.3
Tensile stiffness MD
N/m
30230
38385
57518
Tensile stiffness CD
N/m
2096
6488
6689
Tensile stiffness index
Nm/g
104
179
236
Tensile strength MD, dry
N/m
3126
3061
1499
Tensile strength CD, dry
N/m
672
745
630
Tensile index, dry
Nm/g
19
17
12
Stretch MD
%
28
33
13
Stretch CD
%
71
45
44
Stretch sq root(MDCD)
%
45
39
24
Work to rupture MD
J/m 2
647
714
251
Work to rupture CD
J/m 2
347
238
261
Work to rupture index
J/g
6
5
3
Tensile strength MD, water
N/m
2066
3028
568
Tensile strength CD, water
N/m
330
619
185
Tensile index, water
Nm/g
10.8
15.6
3.9
Relative strength, water
%
57
91
33
Tensile str. MD, surfactant
N/m
1536
3002
407
Tensile str. CD, surfactant
N/m
330
647
122
Tensile index, surfactant
Nm/g
9.3
18.2
2.5
Rel. strength, surfactant
%
49
96
15
Absorption DIN, water
g/g
6.0
5.1
3.9
Absorption speed WAT, x-dir. (CD)
s/m
0.4
0.7
1.7
Absorption speed WAT, y-dir. (MD)
s/m
0.8
1.3
2.7
Wet linting
part./
397
228
259
m 2
The tensile stiffness, tensile strength, work to rupture and stretch were measured according to the test method SCAN-P44:81.
The absorption DIN was measured according to the test method DIN 54 540, part 4, with the modification that the sample was suspended vertically during soaking and not in horizontal position as in the standard method.
The absorption speed WAT was measured according to the test method SCAN-P 62:88. However the following modification of the sample was made: Instead of aiming for a total grammage of between 100 and 150 g/m 2 of the sample sheaf, we have aimed for a total thickness of 1 mm. No measurements of the absorption speed in z-direction were made.
These results show superior strength properties both in dry and wet conditions for the nonwoven materials according to the invention. This is believed to be due to the strong network that is created by the man-made fibers present in the material, said network being more or less continuous. The choice of man-made fibers also plays an important role for the strength of the material, and it is seen from the test results that Ex. 2 which contains 40% by weight polypropylene fibers (1.7 dtex/18 mm), has improved strength properties as compared to Ex. 1 containing a mixture of polyester and polypropylene, 25% polyester (1.7 dtex/19 mm) and 17% polypropylene fibers (1.7 dtex/18 mm). However both materials have considerably higher strengths, i.e. tensile strength (dry, water, surfactant), stretch and work to rupture, as compared to the reference material.
The materials according to the invention are less stiff than the reference material.
The materials according to the invention further have improved absorption properties, both total absorbency and absorption or wicking speed (WAT), as compared to the reference material. This is believed to be due to a combination of the high concentration of pulp fibers present in the plurality of cushions protruding from one side of the material, said cushions of pulp fibers being capable of absorbing and holding liquid, and the network of predominantly man-made fibers, said network being adapted to distribute the liquid in the material. | A wetlaid or foam formed hydraulically entangled nonwoven material containing at least 30%, by weight, pulp fibres and at least 20%, by weight, man-made fibres or filaments. The material has a basis weight variation in a non-random pattern in that it comprises a plurality of higher basis weight cushions protruding from one major surface of the material. The cushions as a main component comprise pulp fibres and are surrounded by a lower basis weight network which as a main component comprises the man-made fibres or filaments. The invention further refers to a method for making the material. | 3 |
[0001] This application is a continuation of co-pending U.S. patent application Ser. No. 13/242,125, filed Sep. 23, 2011, now allowed, which is a continuation of U.S. patent application Ser. No. 13/240,908, filed Sep. 22, 2011, now U.S. Pat. No. 8,976,334, which is a continuation of U.S. patent application Ser. No. 12/081,168, filed Apr. 11, 2008, now U.S. Pat. No. 8,259,287, which is a continuation of U.S. patent application Ser. No. 11/098,615, filed Apr. 5, 2005, now U.S. Pat. No. 7,411,654, each of the foregoing applications is incorporated herein its entirety by reference.
FIELD
[0002] The present invention relates to a lithographic apparatus and a method for manufacturing a device.
BACKGROUND
[0003] A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In that instance, a patterning device, which is alternatively referred to as a mask or a reticle, may be used to generate a circuit pattern to be formed on an individual layer of the IC. This pattern can be transferred onto a target portion (e.g. including part of, one, or several dies) on a substrate (e.g. a silicon wafer). Transfer of the pattern is typically via imaging onto a layer of radiation-sensitive material (resist) provided on the substrate. In general, a single substrate will contain a network of adjacent target portions that are successively patterned. Known lithographic apparatus include so-called steppers, in which each target portion is irradiated by exposing an entire pattern onto the target portion at one time, and so-called scanners, in which each target portion is irradiated by scanning the pattern through a radiation beam in a given direction (the “scanning”-direction) while synchronously scanning the substrate parallel or anti-parallel to this direction. It is also possible to transfer the pattern from the patterning device to the substrate by imprinting the pattern onto the substrate.
[0004] It has been proposed to immerse the substrate in the lithographic projection apparatus in a liquid having a relatively high refractive index, e.g. water, so as to fill a space between the final element of the projection system and the substrate. The point of this is to enable imaging of smaller features since the exposure radiation will have a shorter wavelength in the liquid. (The effect of the liquid may also be regarded as increasing the effective NA of the system and also increasing the depth of focus.) Other immersion liquids have been proposed, including water with solid particles (e.g. quartz) suspended therein.
[0005] However, submersing the substrate or substrate and substrate table in a bath of liquid (see for example U.S. Pat. No. 4,509,852, hereby incorporated in its entirety by reference) means that there is a large body of liquid that must be accelerated during a scanning exposure. This requires additional or more powerful motors and turbulence in the liquid may lead to undesirable and unpredictable effects.
[0006] One of the solutions proposed is for a liquid supply system to provide liquid on only a localized area of the substrate and in between the final element of the projection system and the substrate using a liquid confinement system (the substrate generally has a larger surface area than the final element of the projection system). One way which has been proposed to arrange for this is disclosed in WO 99/49504, hereby incorporated in its entirety by reference. As illustrated in FIGS. 2 and 3 , liquid is supplied by at least one inlet IN onto the substrate, desirably along the direction of movement of the substrate relative to the final element, and is removed by at least one outlet OUT after having passed under the projection system. That is, as the substrate is scanned beneath the element in a −X direction, liquid is supplied at the +X side of the element and taken up at the −X side. FIG. 2 shows the arrangement schematically in which liquid is supplied via inlet IN and is taken up on the other side of the element by outlet OUT which is connected to a low pressure source. In the illustration of FIG. 2 the liquid is supplied along the direction of movement of the substrate relative to the final element, though this does not need to be the case. Various orientations and numbers of in- and out-lets positioned around the final element are possible, one example is illustrated in FIG. 3 in which four sets of an inlet with an outlet on either side are provided in a regular pattern around the final element.
[0007] Another solution which has been proposed is to provide the liquid supply system with a seal member which extends along at least a part of a boundary of the space between the final element of the projection system and the substrate table. Such a solution is illustrated in FIG. 4 . The seal member is substantially stationary relative to the projection system in the XY plane though there may be some relative movement in the Z direction (in the direction of the optical axis). A seal is formed between the seal member and the surface of the substrate. Desirably the seal is a contactless seal such as a gas seal. Such a system with a gas seal is illustrated in FIG. 5 and disclosed in EP-A-1 420 298 hereby incorporated in its entirety by reference.
[0008] In EP-A-1 420 300 the idea of a twin or dual stage immersion lithography apparatus is disclosed. Such an apparatus is provided with two stages for supporting the substrate. Leveling measurements are carried out with a stage at a first position, without immersion liquid, and exposure is carried out with a stage at a second position, where immersion liquid is present. Alternatively, the apparatus has only one stage.
[0009] The seal member disclosed in EP-A-1 420 298 has several problems. Although the system can provide immersion liquid between the final element of the projection system and the substrate, the immersion liquid can sometimes overflow and sometimes recirculation of immersion liquid in the space between the final element of the projection system and the substrate occurs which can result in imaging errors when the radiation beam is projected through the recirculation areas thereby heating immersion liquid up and changing its refractive index. Furthermore, overflow of the seal member is hard to avoid in certain circumstances.
SUMMARY
[0010] It is desirable to provide a seal member or barrier member which overcomes some of the above mentioned problems. It is an aspect of the present invention to provide a seal member or barrier member in which turbulent flow is reduced and in which overflowing of the immersion liquid is reduced.
[0011] According to an aspect of the present invention, there is provided a lithographic apparatus including a substrate table constructed to hold a substrate; a projection system configured to project a patterned radiation beam onto a target portion of the substrate, and a barrier member having a surface surrounding a space between a final element of the projection system and the substrate table configured to contain a liquid in the space between the final element and the substrate; the barrier member including a liquid inlet configured to provide liquid to the space and a liquid outlet configured to remove liquid from the space; wherein the liquid inlet and/or liquid outlet extend(s) around a fraction of the inner circumference of the surface.
[0012] According to another aspect of the present invention, there is provided a lithographic apparatus including a substrate table constructed to hold a substrate; a projection system configured to project a patterned radiation beam onto a target portion of the substrate, and a barrier member having a surface surrounding a space between a final element of the projection system and the substrate table configured to contain a liquid in the space between the final element and the substrate; the barrier member including a liquid inlet configured to provide liquid to the space, the inlet including a chamber in the barrier member separated from the space by a plate member, the plate member forming at least part of the surface and having a plurality of through holes extending between the chamber and the space for the flow of liquid therethrough.
[0013] According to another aspect of the present invention, there is provided a lithographic apparatus including a substrate table constructed to hold a substrate; a projection system configured to project a patterned radiation beam onto a target portion of the substrate; a liquid supply system configured to supply liquid to a space between a final element of the projection system and a substrate; and a control system configured to dynamically vary the rate of extraction of liquid by the liquid supply system from the space and/or dynamically vary the rate of supply of liquid by the liquid supply system such that a level of liquid in the space is maintained between a predetermined minimum and a predetermined maximum.
[0014] According to another aspect of the present invention, there is provided a lithographic apparatus including a substrate table constructed to hold a substrate; a projection system configured to project a patterned radiation beam onto a target portion of the substrate; and a liquid supply system configured to provide liquid to a space between a final element of the projection system and a substrate; wherein the liquid supply system includes an extractor configured to remove liquid from the space, the extractor including a two dimensional array of orifices through which the liquid can be extracted from the space.
[0015] According to another aspect of the present invention, there is provided a device manufacturing method including projecting a patterned beam of radiation onto a substrate using a projection system, wherein a barrier member has a surface which surrounds the space between a final element of the projection system which projects the patterned beam and the substrate thereby containing a liquid in a space between the final element and the substrate; providing liquid to the space through a liquid inlet; and removing liquid from the space via a liquid outlet, wherein the liquid inlet and/or liquid outlet extend(s) around a fraction of the inner circumference of the surface.
[0016] According to another aspect of the present invention, there is provided a device manufacturing method including projecting a patterned beam of radiation onto a substrate using a projection system, wherein a liquid is provided between a final element of the projection system and the substrate, the liquid being contained by a barrier member having a surface, the liquid being provided to the space through an inlet which includes a chamber in the barrier member separated from the space by a plate member and the plate member having a plurality of through holes extending between the chamber and the space through which the liquid flows.
[0017] According to another aspect of the present invention, there is provided a device manufacturing method including projecting a patterned beam of radiation onto a substrate using a projection system, wherein liquid is provided to a space between the final element of a projection system and the substrate and the rate of extraction of liquid from the space is dynamically varied and/or the rate of supply of liquid to the space is dynamically varied to maintain the level of liquid in the space between a predetermined minimum and a predetermined maximum.
[0018] According to another aspect of the present invention, there is provided a device manufacturing method including projecting a patterned beam of radiation onto a substrate using a projection system, wherein liquid is provided to a space between a final element of a projection system and a substrate; liquid being extracted from the space through an extractor which includes a two dimensional array of orifices.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:
[0020] FIG. 1 depicts a lithographic apparatus according to an embodiment of the present invention;
[0021] FIGS. 2 and 3 depict a liquid supply system used in a prior art lithographic projection apparatus;
[0022] FIG. 4 depicts a liquid supply system according to another prior art lithographic projection apparatus;
[0023] FIG. 5 depicts a seal member as disclosed in European Application No. 03252955.4;
[0024] FIG. 6 depicts schematically, in cross-section, a seal member of the present invention;
[0025] FIGS. 7 a and b depict, in plan, a seal member of the present invention;
[0026] FIGS. 8 a - c depict variations in flow direction through the seal member with hole diameter to plate thickness ratio of immersion liquid;
[0027] FIGS. 9 a - e illustrate different embodiments of overflows according to the present invention;
[0028] FIGS. 10 a - e depict different embodiments for liquid extraction according to the present invention; and
[0029] FIG. 11 depicts the control system for the management of immersion liquid in the seal member according to the present invention.
DETAILED DESCRIPTION
[0030] FIG. 1 schematically depicts a lithographic apparatus according to an embodiment of the present invention. The apparatus includes an illumination system (illuminator) IL configured to condition a radiation beam B (e.g. UV radiation or DUV radiation). A support (e.g. a mask table) MT is constructed to support a patterning device (e.g. a mask) MA and is connected to a first positioning device PM configured to accurately position the patterning device in accordance with certain parameters. A substrate table (e.g. a wafer table) WT is constructed to hold a substrate (e.g. a resist-coated wafer) W and is connected to a second positioning device PW configured to accurately position the substrate in accordance with certain parameters. A projection system (e.g. a refractive projection lens system) PS is configured to project a pattern imparted to the radiation beam B by patterning device MA onto a target portion C (e.g. including one or more dies) of the substrate W. A reference frame RF is configured to support the projection system PS.
[0031] The illumination system may include various types of optical components, such as refractive, reflective, magnetic, electromagnetic, electrostatic or other types of optical components, or any combination thereof, for directing, shaping, or controlling radiation.
[0032] The support supports, e.g. bears the weight of, the patterning device. It holds the patterning device in a manner that depends on the orientation of the patterning device, the design of the lithographic apparatus, and other conditions, such as for example whether or not the patterning device is held in a vacuum environment. The support can use mechanical, vacuum, electrostatic or other clamping techniques to hold the patterning device. The support may be a frame or a table, for example, which may be fixed or movable as required. The support may ensure that the patterning device is at a desired position, for example with respect to the projection system. Any use of the terms “reticle” or “mask” herein may be considered synonymous with the more general term “patterning device.”
[0033] The term “patterning device” used herein should be broadly interpreted as referring to any device that can be used to impart a radiation beam with a pattern in its cross-section such as to create a pattern in a target portion of the substrate. It should be noted that the pattern imparted to the radiation beam may not exactly correspond to the desired pattern in the target portion of the substrate, for example if the pattern includes phase-shifting features or so called assist features. Generally, the pattern imparted to the radiation beam will correspond to a particular functional layer in a device being created in the target portion, such as an integrated circuit.
[0034] The patterning device may be transmissive or reflective. Examples of patterning devices include masks, programmable mirror arrays, and programmable LCD panels. Masks are well known in lithography, and include mask types such as binary, alternating phase-shift, and attenuated phase-shift, as well as various hybrid mask types. An example of a programmable mirror array employs a matrix arrangement of small mirrors, each of which can be individually tilted so as to reflect an incoming radiation beam in different directions. The tilted mirrors impart a pattern in a radiation beam which is reflected by the mirror matrix.
[0035] The term “projection system” used herein should be broadly interpreted as encompassing any type of projection system, including refractive, reflective, catadioptric, magnetic, electromagnetic and electrostatic optical systems, or any combination thereof, as appropriate for the exposure radiation being used, or for other factors such as the use of an immersion liquid or the use of a vacuum. Any use of the term “projection lens” herein may be considered as synonymous with the more general term “projection system”.
[0036] As here depicted, the apparatus is of a transmissive type (e.g. employing a transmissive mask). Alternatively, the apparatus may be of a reflective type (e.g. employing a programmable mirror array of a type as referred to above, or employing a reflective mask).
[0037] The lithographic apparatus may be of a type having two (dual stage) or more substrate tables (and/or two or more mask tables). In such “multiple stage” machines the additional tables may be used in parallel, or preparatory steps may be carried out on one or more tables while one or more other tables are being used for exposure.
[0038] Referring to FIG. 1 , the illuminator IL receives radiation from a radiation source SO. The source and the lithographic apparatus may be separate entities, for example when the source is an excimer laser. In such cases, the source is not considered to form part of the lithographic apparatus and the radiation is passed from the source SO to the illuminator IL with the aid of a beam delivery system BD including, for example, suitable directing mirrors and/or a beam expander. In other cases the source may be an integral part of the lithographic apparatus, for example when the source is a mercury lamp. The source SO and the illuminator IL, together with the beam delivery system BD if required, may be referred to as a radiation system.
[0039] The illuminator IL may include an adjusting device AD to adjust the angular intensity distribution of the radiation beam. Generally, at least the outer and/or inner radial extent (commonly referred to as σ-outer and σ-inner, respectively) of the intensity distribution in a pupil plane of the illuminator can be adjusted. In addition, the illuminator IL may include various other components, such as an integrator IN and a condenser CO. The illuminator may be used to condition the radiation beam, to have a desired uniformity and intensity distribution in its cross-section.
[0040] The radiation beam B is incident on the patterning device (e.g., mask MA), which is held on the support (e.g., mask table MT), and is patterned by the patterning device. Having traversed the mask MA, the radiation beam B passes through the projection system PS, which projects the beam onto a target portion C of the substrate W. With the aid of the second positioning device PW and a position sensor IF (e.g. an interferometric device, linear encoder or capacitive sensor), the substrate table WT can be moved accurately, e.g. so as to position different target portions C in the path of the radiation beam B. Similarly, the first positioning device PM and another position sensor (which is not explicitly depicted in FIG. 1 but which may be an interferometric device, linear encoder or capacitive sensor) can be used to accurately position the mask MA with respect to the path of the radiation beam B, e.g. after mechanical retrieval from a mask library, or during a scan. In general, movement of the mask table MT may be realized with the aid of a long-stroke module (coarse positioning) and a short-stroke module (fine positioning), which form part of the first positioning device PM. Similarly, movement of the substrate table WT may be realized using a long-stroke module and a short-stroke module, which form part of the second positioning device PW. In the case of a stepper, as opposed to a scanner, the mask table MT may be connected to a short-stroke actuator only, or may be fixed. Mask MA and substrate W may be aligned using mask alignment marks M 1 , M 2 and substrate alignment marks P 1 , P 2 . Although the substrate alignment marks as illustrated occupy dedicated target portions, they may be located in spaces between target portions (these are known as scribe-lane alignment marks). Similarly, in situations in which more than one die is provided on the mask MA, the mask alignment marks may be located between the dies.
[0041] The depicted apparatus could be used in at least one of the following modes:
[0042] 1. In step mode, the mask table MT and the substrate table WT are kept essentially stationary, while an entire pattern imparted to the radiation beam is projected onto a target portion C at one time (i.e. a single static exposure). The substrate table WT is then shifted in the X and/or Y direction so that a different target portion C can be exposed. In step mode, the maximum size of the exposure field limits the size of the target portion C imaged in a single static exposure.
[0043] 2. In scan mode, the mask table MT and the substrate table WT are scanned synchronously while a pattern imparted to the radiation beam is projected onto a target portion C (i.e. a single dynamic exposure). The velocity and direction of the substrate table WT relative to the mask table MT may be determined by the (de-) magnification and image reversal characteristics of the projection system PS. In scan mode, the maximum size of the exposure field limits the width (in the non-scanning direction) of the target portion in a single dynamic exposure, whereas the length of the scanning motion determines the height (in the scanning direction) of the target portion.
[0044] 3. In another mode, the mask table MT is kept essentially stationary holding a programmable patterning device, and the substrate table WT is moved or scanned while a pattern imparted to the radiation beam is projected onto a target portion C. In this mode, generally a pulsed radiation source is employed and the programmable patterning device is updated as required after each movement of the substrate table WT or in between successive radiation pulses during a scan. This mode of operation can be readily applied to maskless lithography that utilizes programmable patterning device, such as a programmable mirror array of a type as referred to above.
[0045] Combinations and/or variations on the above described modes of use or entirely different modes of use may also be employed.
[0046] FIG. 6 illustrates the seal member or barrier member 12 of the present invention. Working radially outwardly from the optical axis of the projection system, there is provided a plurality of inlets 124 through which immersion liquid 500 is provided to the space 11 between the projection system PS and the substrate W. On the bottom surface 80 of the seal member 12 there is then provided a liquid removal device 180 such as the one disclosed in U.S. application Ser. No. 10/921,348 filed Aug. 19, 2004, hereby incorporated in its entirety by reference. Radially outwardly of the liquid removal device 180 is provided a recess 320 which is connected through inlet 322 to the atmosphere and via outlet 324 to a low pressure source. Radially outwardly of recess 320 is a gas knife 420 . The arrangement of these three items on the bottom surface 80 of the seal member 12 is described in detail in U.S. Application 60/643,626 filed Jan. 14, 2005 hereby incorporated in its entirety by reference. At the top inner surface of the seal member 12 is a vertically extending protrusion or dike 220 over which immersion liquid 500 can flow into overflow area 222 and which can then be extracted through hole array 224 via a low pressure source attached to port 228 .
[0047] FIG. 6 is a schematic cross-section of the seal member 12 . Each of the five elements described above are not necessarily present around the entire circumference of the seal member. This is particularly the case with the immersion liquid inlets 124 and the liquid outlet or extractor (i.e. the dike 220 /hole array 224 ). As can be seen in FIG. 7 a , these can be advantageously provided only around a localized inner circumference of the seal member 12 and desirably opposite each other. As can be seen from figures, the liquid inlets 124 and liquid outlet are at different distances from the substrate W. Suitable fractions of length of liquid inlets 124 and/or liquid outlet is less than ½, desirably less than ⅓ of the inner circumference of the seal member 12 . Desirably the length of the liquid inlets 124 and/or liquid outlet is more than 1/20, more desirably more than 1/15 or 1/10 of the inner circumference of the seal member 12 . This helps in creating a laminar non-turbulent flow of immersion liquid from the outlets 124 , across the space 11 (i.e. a cross-flow) between the projection system PS and the substrate through the target portion TP through which the radiation beam images the substrate, and out of the space through hole array 224 . It is also possible to encourage flow of the immersion liquid across the space 11 by providing the liquid extraction unit 180 on the opposite side of the seal member 12 to the inlet ports 124 but this is not necessarily the case. Alternatively, the extraction unit 180 can be positioned around the entire circumference, perhaps with a larger extraction pressure applied to it opposite the inlets 124 . FIG. 7 b illustrates another embodiment in which three liquid outlets or extractors 224 are provided around the inner circumference of the barrier member 12 . The three outlets are positioned at roughly 120° apart, with the biggest outlet being opposite to the liquid inlets 124 and the other two outlets being smaller and positioned on either side of the inlets 124 .
[0048] The way in which the liquid is provided to the liquid inlets 124 and the design of the liquid inlets 124 themselves will now be described in detail with reference to FIGS. 6 and 8 . As can be seen in FIG. 6 , immersion liquid is provided through inlet 128 into the seal member 12 . A first pressure drop is created in the immersion liquid by forcing it through an orifice 121 which puts a first chamber 120 into liquid communication with a second chamber 122 . In reality orifice 121 is a plurality of individual holes created in plate 123 , separating the chambers 120 and 122 . The plurality of holes 121 are arranged in a regular one-dimensional array in the illustrated embodiment, but other arrangements such as two or more parallel rows of holes 121 one above another can also be used. The holes 121 distribute the flow over plate 126 , which separates chamber 122 from the space 11 , in the tangential direction and ensure a homogeneous flow over the whole width of the array of orifices 124 irrespective of the configuration of the supply 128 . Once the immersion liquid has entered the second chamber 122 , it enters through orifices 124 into the space 11 between the projection system PS and the substrate W. The orifices 124 are provided in a (regular) two-dimensional array in the plate 126 of the seal member 12 . This creates a parallel, homogeneous flow inside the space 11 . The array of orifices 124 is positioned towards the lower surface 80 of the plate 126 , desirably below the level of the projection system PS when the seal member 12 is in use.
[0049] The present inventors have found that the ratio of orifice 124 diameter d to outer plate 126 thickness t may be considered in controlling the direction in which the immersion liquid leaves the chamber 122 . This is even the case if all of the orifices 124 are drilled through the plate 126 in a plane which will be parallel to the substrate W in use.
[0050] As can be seen from FIG. 8 a , if the diameter d of the orifice 124 is greater than the thickness t of the outer plate 126 , the flow of immersion liquid can exit at an angle illustrated by arrow 127 i.e. non parallel to the substrate W surface. In FIG. 8 b , the wall thickness t is equal to the diameter d of the orifice 124 and in FIG. 8 c , the diameter d of the orifice 124 is less than the thickness t of the outer wall 126 . It has been found that the orifice diameter should be less than the thickness of the plate 126 . Typically the plate thickness will be of the region of 0.4 mm and the diameter of the orifice 124 is in the region of 0.15 mm for flow to exit parallel to the substrate surface and parallel to the direction in which the orifice is machined in the plate 126 (the plate 126 is not necessarily vertically orientated and can be inclined as illustrated). The dimensions are a trade off between having small enough orifices 124 to create a large enough pressure drop and having a plate thickness thick enough to give the desired stiffness. As a result, a much more laminar flow with a lower velocity and less mixing is produced than with prior art designs. The parallel flow is encouraged by making the small orifice in a relatively thick plate. The desired ratio of plate thickness t to orifice diameter d is at least 1:2.5 so that the flow can be directed in the same direction as the axis of the orifice. The orifices are machined (drilled) substantially parallel to each other and substantially parallel to the plane of the substrate W and substantially perpendicular to the surface of the plate 126 through which they extend. The orifices can be cut by laser as small as 20 μm and as large as desired. Another way of manufacturing small holes in a plate is by electroforming (electrolytical deposition) of, for example, nickel. Holes with a diameter of 5 to 500 μm in a sheet of thickness between 10 μm and 1 mm are possible using this technique. This technique can be used to produce both inlets and outlets as described elsewhere in this description. However, unlike with the other manufacturing methods, it is difficult to align accurately the axis of the through hole using this method.
[0051] It has been found that the number of orifices and the angle their axis makes with the outer plate 126 as well as their diameter has an effect on the direction in which the liquid flows. Generally, with a single hole, flow is directed slightly away from the axis of the hole towards the side of the plate with which the axis of the hole makes an acute angle, i.e. in FIG. 8 , if the axis of the hole is parallel to the substrate W, slightly downwards from horizontal towards the substrate. The more holes that are present, the more pronounced the effect. This effect can be used to redirect flows of any fluid types in many applications (e.g. airshowers, purge hoods) and thereby eliminate or reduce the need for vanes or deflection plates or use of the Coanda effect. The effect is so strong that it can act against the force of gravity. It is thought that the origin of the effect is the interaction of a large number of asymmetrical fluid jets. The flow deflection also occurs when the fluid flows into a large volume of the same fluid, so the flow deflection is not related to the teapot leakage problem where tea leaks along the spout of the teapot. If the outer wall 126 is vertical, the axis of the orifices 124 should be parallel to the substrate W upper surface. If the outer wall 126 is included, as illustrated, in order to achieve flow parallel to the substrate surface, it has been found that the axis of the orifices 124 should be inclined away from the top surface of the substrate by about 20 degrees, desirably in the range of from 5 to 40 degrees.
[0052] The two-step pressure drop (there is a pressure drop as described, when the liquid goes through orifices 121 and clearly there will also be a pressure drop when the liquid passes through orifices 124 ) is arranged to be over the whole of the width of the supply and height of the supply. In this way the first pressure drop ensures that the flow is provided evenly over the orifices 124 irrespective of the supply channel configuration (i.e. the channel between input 128 and chamber 120 ), as described.
[0053] The laminar flow is desirable because it prevents recirculation of immersion liquid which can result in those recirculated areas of liquid becoming hotter or colder than the remaining liquid and therefore having a different refractive index or resulting in certain areas of the resist being more dissolved by the immersion liquid than others (i.e. a non-uniform concentration of resist in the immersion liquid which can change the refractive index of the immersion liquid) and also preventing transport of the resist to the projection lens.
[0054] Desirably the density of holes in the plate 126 is of the order of 15 holes per square mm. A range of from 1 to 30 holes per square mm is desirable.
[0055] In prior art seal members, liquid has been extracted either from the bottom surface 80 of the seal member 12 or from a single outlet positioned in the inner wall of the seal member 12 defining the space 11 . The outlet has either been a one dimensional array of holes around the entire circumference of the inner surface of the seal member 12 or has been an annular groove around the circumference. A problem with this type of liquid extraction is that the holes in the inner wall of the seal member are either extracting or are not extracting and the transition between extraction and non extraction can result in undesirable vibrations of the seal member 12 . One solution which has been proposed is disclosed in European Patent Application No. 04256585.3, hereby incorporated in its entirety by reference. In that document, a dike 220 is provided similar to the one illustrated in FIG. 6 . Here, if the level of immersion liquid 500 in the space rises above the level of the dike, it overflows the dike into a pool or overflow 220 behind the dike and with a lower level than the dike. The immersion liquid may then be removed from the overflow 222 . Again a difficulty with this system is that extraction either tends to happen or does not happen and there is a difficulty with the control of the amount of extraction resulting in occasional overflow.
[0056] In the present invention, a two dimensional array of holes or mesh 224 is provided in a wall of the seal member 12 through which liquid is extracted. Immersion liquid which either overflows a dike 220 or flows above the level of the lower most hole of the 2d array 224 is extracted by extractor 228 . Desirably a non-homogenous array of holes in the wall of the seal member is used in which the number of holes per unit area and/or size of holes increases from a minimum furthest away from the substrate to a maximum nearest the substrate or at lowest position. Thus there is a smaller resistance for the immersion liquid to pass through the array at the lowest level and a higher resistance for air at the upper level of the plate. Thus by using a vertical gradient in the hole distribution (either in size or density or both) the resistance of the plate to flow is increased with increasing vertical height. Thus the problem of the flow of air out through the holes pushing away water and thereby making level control difficult is addressed. Such embodiments are illustrated in FIGS. 9 a - e. In an alternative embodiment illustrated in FIGS. 10 a - e no dike is present and the immersion liquid is removed as soon as its level reaches above the lower most hole of array 224 . As is illustrated in FIGS. 7 a and b, the extraction arrangements illustrated in FIGS. 9 a - e and 10 a - e may be provided only around a fraction of the inner circumference of the seal member 12 , desirably opposite the inlets 124 . However, clearly the outlets illustrated in FIGS. 9 a - e and 10 a - e can be provided the whole way around the inner circumference of the seal member 12 . It is possible to provide a different level of under pressure to the outlet 228 around the circumference of the seal member in the latter embodiment thereby arranging for different extraction rates around the inner circumference of the seal member 12 . Arranging for different extractions rates either by varying the pressure of an extractor extending around the entire circumference of the seal member 12 or by arranging for only a localized extractor can help in promoting laminar flow of immersion liquid from the inlets 124 across the target portion TP and out through the extractor.
[0057] The array of holes 224 may include holes of the order of between 0.1 and 0.5 mm in diameter. A density of 0.25 to 5 holes per square mm is desirable. The use of the two dimensional array of holes has the benefit that the immersion liquid 11 is more easily controlled because a higher immersion liquid level wets more holes of the array 224 resulting in a higher extraction rate. Conversely, a lower level of immersion liquid will wet fewer holes and thereby result in a lower extraction rate. In this way the extraction of immersion liquid is automatically regulated without the need for adjusting the extraction rate at outlet 228 . This is particularly the case when the hole array 224 is vertically or at least partly vertically orientated. The use of a dike 220 allows the array of holes 224 to extend to a lower level than the dike increasing the extraction capacity. If the barrier member 12 is made liquid philic (hydrophilic in the case that the immersion liquid is water) build up of liquid level due to surface tension effects can be minimized.
[0058] The overflow 220 allows sudden and short build-up of immersion liquid without the risk of over spilling. For example, during moving of the substrate W or a closing disc up closer to the surface of the seal member 12 there will be a sudden decrease in the volume of the space 11 and therefore a rise in immersion liquid level. The ditch 222 can accommodate some of this excess liquid while it is extracted.
[0059] It should be appreciated that the array of holes 310 could be provided as a mesh or equivalent.
[0060] FIGS. 9 a - e illustrate different configurations for the dike embodiment of the extractor. In FIG. 9 a , the immersion liquid enters a volume 330 before being extracted by extractor 228 . By contrast, in the design of FIG. 9 b , it is arranged that the immersion liquid enters a narrow gap 340 before being extracted at outlet 228 . Due to capillary forces, the gap 340 is completely filled with immersion liquid (if it is designed narrow enough) and if the under-pressure is matched with the size of the holes 224 the formation of bubbles in the extracted immersion liquid or the inclusion of bubbles in the extracted immersion liquid can be prevented thereby making the extraction flow a single phase flow and thereby preventing deleterious vibrations. In FIGS. 9 c and 9 d , different angles of the wall in which the array of holes 224 are formed are illustrated. In FIG. 9 e a top plate 223 is added above the overflow area which enhances the extraction capacity due to the fact that the suction of the liquid is brought closer to the projection system PS, where the liquid meniscus tries to follow the projection system contour. The purpose of these diagrams is to illustrate that many configurations are possible which still have the aspects of the present invention.
[0061] FIGS. 10 a - e illustrate various embodiments without the dike 220 . Any angle of inclination of the wall in which the array of holes 224 are formed is possible and different configurations of paths for the immersion liquid to follow to the outlet 228 are illustrated. For example, in FIG. 10 b , the gap 340 is similar to the gap in FIG. 9 b such that single phase flow extraction is possible, in FIG. 10 e , the top plate 223 is similar to that in FIG. 9 e.
[0062] Another way to help minimize the risk of overflow of immersion liquid is illustrated in FIG. 11 . The system illustrated in FIG. 11 matches the amount of incoming immersion liquid with the amount of removed immersion liquid by dynamically varying the rates of extraction and input. As can be seen, immersion liquid is supplied to the seal member 12 through inlet 128 and is removed through outlets 184 , 228 and 328 as is described above in reference to FIG. 6 . Having a controllable supply allows more flexibility in operating circumstances. For example, more variations in the leak flow rate through outlet 328 are allowable and even if the extraction system 224 does not have sufficient capacity to cope with the maximum flow, that does not necessarily lead to overflow because the supply of immersion liquid can be reduced to compensate. Even with a constant supply flow, a controllable extraction is desirable because different operating conditions, for example scanning in a different direction, can result in variable leak or extraction parameters which can be coped with by varying the extraction. Each extraction port includes a controllable valve 1228 , 1184 , 1328 . The outlet ports 228 , 128 , 328 are all connected to a low pressure sources 2228 , 2148 , 2328 via a valve as illustrated. Extracted immersion liquid is lead to a reservoir 1500 which, if the immersion liquid is to be recycled, can be the source for the inlet 1248 . The supply is controlled by a valve 1128 and an overflow path to the reservoir 1500 is provided with a valve 1148 controlling that.
[0063] The water level control mechanism allows the supply rate of immersion liquid to be varied as well as the extraction through the overflow 224 , through the liquid extractor 180 and through the recess extractor 320 . Each of the valves 1228 , 1148 , 1128 , 1184 , 1328 are variable valves though they may be valves which are either on or off. The amount of extraction can be varied either by varying the under pressure applied, using the valves controlling the under pressure or by varying the valves 1128 , 1184 , 1328 or by varying the bypass to ambient (also illustrated in FIG. 11 ).
[0064] There are three options to determine when a dynamic control action is needed. These are direct feedback in which the level of the immersion liquid is measured, indirect feedback in which the extraction flows from each of the extractors is measured or feed-forward in which a knowledge of the extraction flow and the operating circumstances is used to adjust the supply and/or extraction flows when circumstances change.
[0065] The water level may be measured in several ways, for example by a float in the reservoir 1500 or in the space 11 , or by measuring the pressure of water at the bottom of the seal member 12 . By determining the position of the water surface by reflection and detection of acoustical or optical signals on the upper surface of the immersion liquid. Further possibilities are by measuring the absorption or transmission of an acoustical, optical or electrical signal as a function of the amount of water or by measuring heat loss of a submerged wire in a known position in the space 11 , the further the wire is submerged, the higher the heat loss.
[0066] In an embodiment, there is provided a lithographic apparatus, comprising: a substrate table constructed to hold a substrate; a projection system configured to project a patterned radiation beam onto a target portion of the substrate; a liquid supply system configured to supply liquid to a space between the projection system and the substrate table; and a control system configured to dynamically vary a rate of extraction of liquid by the liquid supply system from the space and/or dynamically vary a rate of supply of liquid by the liquid supply system such that a level of liquid in the space is maintained between a certain minimum and a certain maximum.
[0067] In an embodiment, the control system is configured to dynamically vary the rate or rates in response to a determination of a level of liquid in the space. In an embodiment, the lithographic apparatus further comprises a pressure sensor configured to measure a pressure of the liquid at a certain position in the space to determine the level of liquid in the space. In an embodiment, the lithographic apparatus further comprises an optical and/or acoustic source and a corresponding optical and/or acoustic detector configured to determine the level of liquid in the space by reflection and subsequent detection of an optical and/or acoustic signal off the top surface of the liquid. In an embodiment, the lithographic apparatus further comprises an acoustical/optical/electrical signal generator configured to generate an acoustical/optical/electrical signal in liquid in the space and a detector configured to detect the acoustical/optical/electrical signal to determine the level of liquid in the space. In an embodiment, the lithographic apparatus further comprises a wire configured to be submerged in the liquid at a certain location in the space and a detector configured to measure a temperature of the wire to determine the level of liquid in the space. In an embodiment, the lithographic apparatus further comprises a float configured to float on the top surface of the liquid in the space and a sensor configured to measure a position of the float to determine the level of liquid in the space. In an embodiment, the control system is configured to actively vary the rate or rates based on a measurement of an amount of liquid extracted from the space by the liquid supply system. In an embodiment, the control system is configured to dynamically vary the rate or rates in a feed forward manner based on operating circumstances of the apparatus. In an embodiment, the lithographic apparatus further comprises valves configured to control the rate of extraction and/or supply. In an embodiment, the lithographic apparatus further comprises valves configured to control an under pressure applied to a liquid extractor of the liquid supply system.
[0068] In an embodiment, there is provided a device manufacturing method, comprising: projecting a patterned beam of radiation onto a substrate using a projection system of a lithographic apparatus, wherein liquid is provided to a space between the projection system and the substrate and a rate of extraction of liquid from the space is dynamically varied and/or the rate of supply of liquid to the space is dynamically varied to maintain a level of liquid in the space between a certain minimum and a certain maximum.
[0069] In an embodiment, there is provided a lithographic apparatus, comprising: a substrate table constructed to hold a substrate; a projection system configured to project a patterned radiation beam onto a target portion of the substrate; and a barrier member having a surface surrounding a space between the projection system and the substrate table, the barrier member being configured to at least partly confine a liquid in the space, the barrier member comprising a liquid inlet configured to provide liquid to the space and a liquid outlet configured to remove liquid from the space, wherein the liquid inlet and/or the liquid outlet extends around a fraction of the inner periphery of the surface.
[0070] In an embodiment, the fraction is less than about ½. In an embodiment, the fraction is less than about ⅓. In an embodiment, the fraction is more than about 1/20. In an embodiment, the fraction is more than about 1/15. In an embodiment, the liquid inlet and the liquid outlet are positioned on the surface such that they face one another across the space. In an embodiment, the liquid inlet and liquid outlet are positioned along different parts of the surface around the inner periphery. In an embodiment, the liquid outlet is arranged to provide a variable liquid extraction rate along its length in the direction following the inner periphery. In an embodiment, a maximum extraction rate is provided substantially opposite the liquid inlet. In an embodiment, the liquid outlet extends substantially around the inner periphery. In an embodiment, the liquid inlet and the liquid outlet extend around a fraction of the inner periphery of the surface, the fraction of the inner periphery for the liquid inlet being smaller than the fraction of the inner periphery for the liquid outlet. In an embodiment, the liquid outlet is positioned radially outwardly, relative to the optical axis of the projection system, of the liquid inlet. In an embodiment, the lithographic apparatus comprises at least three liquid outlets, one liquid outlet facing the liquid inlet across the space and one liquid outlet on each side of the liquid inlet.
[0071] In an embodiment, there is provided a device manufacturing method, comprising: projecting a patterned beam of radiation onto a substrate using a projection system, wherein a barrier member has a surface which surrounds a space between the projection system and the substrate, the barrier member configured to at least partly contain a liquid in the space; providing liquid to the space through a liquid inlet; and removing liquid from the space via a liquid outlet, wherein the liquid inlet and/or the liquid outlet extends around a fraction of the inner periphery of the surface.
[0072] Although specific reference may be made in this text to the use of lithographic apparatus in the manufacture of ICs, it should be understood that the lithographic apparatus described herein may have other applications, such as the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, flat-panel displays, liquid-crystal displays (LCDs), thin-film magnetic heads, etc. It should be appreciated that, in the context of such alternative applications, any use of the terms “wafer” or “die” herein may be considered as synonymous with the more general terms “substrate” or “target portion”, respectively. The substrate referred to herein may be processed, before or after exposure, in for example a track (a tool that typically applies a layer of resist to a substrate and develops the exposed resist), a metrology tool and/or an inspection tool. Where applicable, the disclosure herein may be applied to such and other substrate processing tools. Further, the substrate may be processed more than once, for example in order to create a multi-layer IC, so that the term substrate used herein may also refer to a substrate that already contains multiple processed layers.
[0073] Although specific reference may have been made above to the use of embodiments of the invention in the context of optical lithography, it should be appreciated that the present invention may be used in other applications, for example imprint lithography, and where the context allows, is not limited to optical lithography. In imprint lithography a topography in a patterning device defines the pattern created on a substrate. The topography of the patterning device may be pressed into a layer of resist supplied to the substrate whereupon the resist is cured by applying electromagnetic radiation, heat, pressure or a combination thereof. The patterning device is moved out of the resist leaving a pattern in it after the resist is cured.
[0074] The terms “radiation” and “beam” used herein encompass all types of electromagnetic radiation, including ultraviolet (UV) radiation (e.g. having a wavelength of or about 365, 248, 193, 157 or 126 nm) and extreme ultra-violet (EUV) radiation (e.g. having a wavelength in the range of 5-20 nm), as well as particle beams, such as ion beams or electron beams.
[0075] The term “lens”, where the context allows, may refer to any one or combination of various types of optical components, including refractive, reflective, magnetic, electromagnetic and electrostatic optical components.
[0076] While specific embodiments of the present invention have been described above, it will be appreciated that the present invention may be practiced otherwise than as described. For example, the present invention may take the form of a computer program containing one or more sequences of machine-readable instructions describing a method as disclosed above, or a data storage medium (e.g. semiconductor memory, magnetic or optical disk) having such a computer program stored therein.
[0077] The present invention can be applied to any immersion lithography apparatus, in particular, but not exclusively, those types mentioned above.
[0078] The descriptions above are intended to be illustrative, not limiting. Thus, it will be apparent to one skilled in the art that modifications may be made to the invention as described without departing from the scope of the claims set out below. | A liquid supply system for an immersion lithographic apparatus provides a laminar flow of immersion liquid between a final element of the projection system and a substrate. A control system minimizes the chances of overflowing and an extractor includes an array of outlets configured to minimize vibrations. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to methods for the treatment of inflammatory joint disease. In particular, the invention relates to the use of blockers of complement component C 5 (“C 5 blockers”) as pharmaceutical agents to treat, established joint inflammation.
BACKGROUND OF THE INVENTION
[0002] I. The Complement System
[0003] The complement system acts in conjunction with other immunological systems of the body to defend against intrusion of cellular and viral pathogens. There are at least 25 complement proteins, which are found as a complex collection of plasma proteins and membrane cofactors. The plasma proteins (which are also found in most other body fluids, such as lymph, bone marrow, synovial fluid, and cerebrospinal fluid) make up about 10% of the globulins in vertebrate serum. Complement components achieve their immune defensive functions by interacting in a series of intricate but precise enzymatic cleavage and membrane binding events. The resulting complement cascade leads to the production of products with opsonic, immunoregulatory, and lytic functions.
[0004] The complement cascade progresses via the classical pathway or the alternative pathway. These pathways share many components, and, while they differ in their early steps, both converge and share the same terminal complement components responsible for the destruction of target cells and viruses.
[0005] The classical complement pathway is typically initiated by antibody recognition of and binding to an antigenic site on a target cell. This surface bound antibody subsequently reacts with the first component of complement, C 1 . The C 1 thus bound undergoes a set of autocatalytic reactions that result in, inter alia, the induction of C 1 proteolytic activity acting on complement components C 2 and C 4 .
[0006] This activated C 1 cleaves C 2 and C 4 into C 2 a, C 2 b, C 4 a, and C 4 b. The function of C 2 b is poorly understood. C 2 a and C 4 b combine to form the C 4 b, 2 a complex, which is an active protease known as classical C 3 convertase. C 4 b, 2 a acts to cleave C 3 into C 3 a and C 3 b. C 3 a and C 4 a are both relatively weak anaphylatoxins that may induce degranulation of mast cells, resulting in the release or histamine and other mediators of inflammation.
[0007] C 3 b has multiple functions. As opsonin, it binds to bacteria, viruses and other cells and particles and tags them for removal from the circulation. C 3 b can also form a complex with C 4 b, C 2 a to produce C 4 b, 2 a, 3 b, or classical C 5 convertase, which cleaves C 5 into C 5 a (another anaphylatoxin), and C 5 b. Alternative C 5 convertase is C 3 b, Bb, C 3 b and performs the same function. C 5 b combines with C 6 yielding C 5 b, 6 , and this complex combines with C 7 to form the ternary complex C 5 b, 6 , 7 . The C 5 b, 6 , 7 complex binds C 8 at the surface of a cell membrane. Upon binding of C 9 , the complete membrane attack complex (MAC) is formed (C 5 b - 9 ) which mediates the lysis of foreign cells, microorganisms, and viruses
[0008] Further discussions of the classical complement pathway, as well as a detailed description of the alternative pathway of complement activation, can be found in numerous publications including, for example, Roitt, et al., 1988, and Muller-Eberhard, 1988.
[0009] II. Joint Inflammation
[0010] A variety of common medical disorders have as a common element the inflammation of the patient's joints. In the United States alone, millions of patients suffer from such joint inflammation. Afflicted individuals are frequently disabled, and the costs of medical care for patients suffering from such disorders are significant. While numerous means are available for treatment of joint inflammation, and new treatments continue to become available, none of these is as safe and effective as could be desired, and there has thus been a long felt need for new approaches and better methods to control joint inflammation.
[0011] Clinically, joint inflammation is associated with joint stiffness, pain, weakness, and sometimes joint fatigue. Uniformly, the joint is tender and swollen, and often erythematous. Diagnosis of the inflammatory nature of the joint disease is frequently based upon this typical clinical presentation as well as upon radiographic examination and aspiration and examination of synovial joint fluid. Examination of joint fluid of an inflamed joint generally reveals elevation of various markers of inflammation, such as, leukocytes (including neutrophils), antibodies, cytokines, cell adhesion molecules, and complement activation products (De Clerck et al., 1989; Heinz et al., 1989; Moffat et al., 1989; Peake et al.,
[0012] [0012] 1989 ; Brodeur et al., 1991; Firestein et al., 1991; Matsubara et al., 1991; Olsen et al., 1991; Oleesky et al., 1991; Jose et al., 1990; Zvaifler, 1968; Zvaifler, 1969a; Zvaifler, 1969b; Zvaifler, 1974; Ward and Zvaifler, 1971; Ward, 1975; Moxley and Ruddy, 1985; Molines et al., 1986; Auda et al., 1990; Olmez et al., 1991; Kahle et al., 1992; Koch et al, 1994; Thorbecke et al., 1992; Saura et al., 1992; Feldman et al., 1990; Feldman et al., 1991; Fong et al., 1994; Harigi et al., 1993; Morgan et al., 1988: Shingu et al., 1994; Abbink et al., 1992; and Corvetta et al., 1992). Radiographic examination of affected joints generally reveals soft tissue swelling and/or erosive changes.
[0013] Joint inflammation is associated with a group of diseases that are referred to medically as arthridities (types of arthritis). The term “arthritis” is used medically to generally describe diseases of the joints. The term, however, is also used to describe certain medical conditions, of which rheumatoid arthritis (RA) is the primary example, that consist of a multiplicity of different pathologic manifestations) including, but by no means limited to, joint disease.
[0014] Discussions of arthritis may thus include diseases such as RA, where joint disorders are only one facet of the varied pathologies associated with the disease. The present invention is directed specifically to the joint disorder aspects of these diseases. The methods of the invention, however, may also have beneficial effects on non-joint-associated pathologies For example, use of the methods of the invention to treat established joint inflammation associated with RA, psoriasis, lupus, and other disorders may also provide therapeutic benefits impacting on some of the other pathologic manifestations of these multifaceted disease states, such as vascular inflammation and nephritis (see, for example, Wurzner, et al., Complement Inflamm. 8:328-340, 1991, U.S. application Ser. No. 09/217,391 filed on Mar. 23, 1994, U.S. application Ser. No. 08/236,208 filed on May 2, 1994, and Sims, et al., U.S. Pat. No. 5,135,916).
[0015] It should be noted that the present invention is not Is; concerned with all types of joint disorders, but only those involving inflation. Thus, for example, the invention is applicable to the treatment of late-stage osteoarthritis (OA), which is an inflammatory joint disease, but generally not to early stage OA, which does not typically have a significant inflammatory component.
[0016] Detailed discussions of the arthridities can be found in numerous medical texts, including Arnett, 1992. Cecil Textbook of Medicine, Wyngaarden et al. (ads.) W. B. Saunders Company, Philadelphia, Chapter 258, pp. 1508-1515; Lipsky, 1994. Harrison's Principles of Internal Medicine, 13th Ed., Isselbacher et al. (eds), McGraw-Hill, Inc., New York, Chapter 285, pp. 1648-1655; and McCarty and Koopman, 1993. Arthritis and Allied Conditions, 12 th Ed. Lea and Febiger, Philadelphia. As discussed in detail in these and other texts, and reviewed below, joint inflammation is associated with numerous local and systemic disease processes.
[0017] Factors Associated with Joint Inflammation
[0018] Joint inflammation is a complex process involving, among other things, activation of both cellular and humoral immune responses.
[0019] Cellular immune responses include infiltration by white blood cells, predominantly neutrophils (also referred to as polymorphonuclear cells or PMNs). Mononuclear white blood cell infiltrates are also common in many inflamed joints. Infiltrating mononuclear cells, including T lymphocytes (as well as cells resident within the joint such as synovial cells, fibroblasts, and endothelial cells) are activated and contribute to the production of multiple inflammatory cytokines including TNF-α, IL-1, IFN-γ, IL-2, IL-6, IL-8, GM-CSF, PDGF and FGF, these latter two being capable of stimulating syovial cell proliferation.
[0020] All of these cytokines are thought to play a role in inducing the production of numerous other inflammatory factors as well as various other mediators of tissue degradation. These factors and mediators of degradation include products of arachidonic acid metabolism (that are active in various intracellular signal transduction pathways), reactive oxygen intermediates, and degradative enzymes such as collagenase, stromelysin, and other neutral proteases, all of which can further contribute to the inflammatory response and to tissue destruction.
[0021] Cellular infiltration into the synovium is enhanced by the upregulation of cell adhesion molecules such as selecting, LPA-3, and members of the ICAM family of Ig-like cell adhesion molecules on cells within the joint. These adhesion molecules promote the infiltration of activated white blood cells into the affected joint by stimulating leukocyte (including lymphocyte) adhesion, migration, and activation.
[0022] The humoral immune system also contributes to joint inflammation. Antibodies are produced within inflamed joints in such diseases as RA, JRA and OA (see below) and generate localized immune complexes that can activate the complement system. As discussed above in greater detail, activated complement components can have cytolytic, cell activating, anaphylatoxic, and chemotactic effects.
[0023] These multifactorial inflammatory responses lead to cartilage destruction and bone erosion that ultimately result in the joint deformity seen in patients with chronic joint inflammation.
[0024] In view of the complex nature of joint inflammation, a variety of theories, many of which are conflicting, have been proposed in the art to explain the relative importance of the various factors involved. Notwithstanding extensive work, there remains a basic controversy in the art as to the relative roles of the cellular and humoral immune systems in joint inflammation, including what role complement plays in such inflammation. See, for example, Andersson and Holmdahl, 1990; Brahn and Trentham, 1989; Chiocchia et al., 1990; Chiocchia et al., 1991; Durie et al., 1993; Goldschmidt et al., 1990; Goldschmidt and Holmdahl, 1991; Holmdahl et al., 1985; Holmdahl et al., 1989; Holmdahl et al., 1990; Hom et al., 1988; Hom et al., 1992; Hom et al., 1993; Mori et al., 1992; Myers et al., 1989A; Nakajima et al., 1993; Osman et al., 1993; Peterman et al., 1993; Seki et al., 1988; Seki et al., 1992; Terato et al,, 1992; Watson et al., 1987; and, in particular, the following reports relating to the complement system and/or the relative roles of T cells and complement components in joint inflammation: Andersson et al., 1991; Andersson et al., 1992; Banerjee et al., 1988B; Banerjee et al., 1989; David, 1992; Fava et al., 1993; Haqqi et, al., 1989; Kakimoto et al, 1988; Maeurer et al., 1992; Morgan et al., 1981; Moxley and Ruddy, 1985; Reife et. al., 1991, Spinella et al., 1991; Spinella and Stuart, 1992; van Lent et al., 1992; Watson et al., 1987; Watson and Townes, 1985; and Williams et al., 1992A. To date, these wide ranging studies have not led to effective treatments for established joint inflammation based on modulation of the complement system and, in particular, based on the use of C 5 blockers.
[0025] The studies of the prophylactic effects of C 5 blockers reported below in Example 2 were designed to determine if C 5 was an appropriate and effective target for pharmacological modulation of the humoral immune system in order to prevent joint inflammation. The surprising effectiveness of C 5 blockers in preventing onset of joint inflammation led to the design and execution of the studies reported in Example 1 in which C 5 blockers were used to treat established inflammation. At the outset of these experiments, it was anticipated that such treatment would have little measurable effect upon established joint inflammation, as it was supposed that C 5 was more important early in the disease process when the chemotactic activity of C 5 a would trigger the infiltration of inflammatory cells. It was further supposed that the involvement of T cells in established disease would continue to provide significant inflammatory stimuli even in the absence of C 5 activity. As shown by the results of Example 1 this expectation was incorrect in that C 5 blockers were found to be surprisingly effective in arresting and/or reducing the inflammation of joints which were already inflamed, while at the same time inhibiting the spread of inflammation to unaffected joints.
[0026] Diseases Commonly Associated with Joint Inflammation
[0027] Rheumatoid arthritis (RA) and juvenile onset rheumatoid arthritis (JRA) are chronic multisystem diseases of unknown cause. RA affects approximately 1% of the population, with women affected three times more commonly than men. The onset is most frequent during the fourth and fifth decades of life. RA and JRA are systemic diseases with numerous pathologic manifestations in addition to their joint inflammatory aspects. In RA, these manifestations include PA vasculitis (inflammation of the blood vessels), which can affect nearly any organ system and can cause numerous pathologic sequelae including polyneuropathy, cutaneous ulceration, and visceral infarction. Pleuropulmonary manifestations include pleuritis, interstitial fibrosis, pleuropulmonary nodules, pneumonitis, and arteritis. Other manifestations include the development of inflammatory rheumatoid nodules on a variety of periarticular structures such as extensor surfaces, as well as on pleura and meninges. Weakness and atrophy of skeletal muscle are common.
[0028] The joint inflammation aspects of RA present as persistent inflammatory synovitis, usually involving peripheral joints in a symmetric distribution. In general, the complex intraarticular inflammatory response seen in RA is of the type described above in the general discussion of joint inflammation.
[0029] Many patients with systemic lupus erythematosis (SLE) also develop joint inflammation referred to as lupus arthritis. SLE is an autoimmune disease of unknown cause in which numerous different cells, tissues, and organs are damaged by pathogenic autoantibodies and immune complexes. Clinical manifestations of SLE are numerous and include a variety of maculopapular rashes, nephritis, cerebritis, vasculitis, hematologic abnormalities including cytopenias and coagulopathies, pericarditis, myocarditis, pleurisy, gastrointestinal symptoms, and the aforementioned joint inflammation.
[0030] Osteoarthritis (OA) represents the most common joint disease of mankind, and OA of the knee is the leading cause of chronic disability in developed countries. It is manifested by pain, stiffness, and swelling of the involved joints. Articular cartilage, responsible for the most critical mechanical functions of the joint, is the major target tissue of OA. The breakdown of articular cartilage in OA is mediated by various enzymes such as metalloproteinases, plasmin, and cathepsin, which are in turn stimulated by various factors that can also act as inflammatory mediators. These factors include cytokines such as interleukin-1, which is known to activate the pathogenic cartilage a synovial proteases.
[0031] The identification of above normal levels of immunoglobulins in cartilage in generalized OA and the demonstration of type II collage-specific antibodies in some OA patients provide evidence of a role for immune activation in this disease state (see, for example, Jasin, 1999). The observation that OA rarely remains monoarticular also suggests that this disease is a systemic disorder of articular cartilage. Synovial inflammation becomes more frequent as the disease progresses. In fact, in late stage OA, histologic evidence of synovial inflammation may be as marked as that in the synovium of patients with RA-associated joint inflammation.
[0032] Psoriatic arthritis is a chronic inflammatory joint disorder that affects 5 to 8% of people with psoriasis. A significant percentage of these individual (one-fourth) develop progressive destructive disease. Twenty-five percent of psoriasis patients with joint inflammation develop symmetric joint inflammation resembling the joint inflammation manifestation of RA, and over half of these go on to develop varying degrees of joint destruction.
[0033] Other Diseases Associated with Joint Inflammation
[0034] A variety of other systemic illnesses have joint inflammation as a prominent feature of the clinical presentation.
[0035] Peripheral joint inflammation occurs in as many as one-fifth of patients with inflammatory bowel disease. The joint inflammation is acute, associated with flare-ups of the bowel disease, and is manifested by swollen, erythematous, warm, and painful joints. Synovial fluids of sufferers have an acute inflammatory exudate of mostly neutrophils, and radiographs demonstrate soft tissue swelling and effusions.
[0036] The syncovitis that accompanies hepatitis B resembles serum sickness, with abrupt onset of fever and articular inflammation. There is generally a symmetric inflammation of joints including the knee, shoulder, wrist, ankles, elbow, and the joints of the hands. Immune complexes containing hepatitis B antigens are present in serum and synovium, lending support to the concept that the synovitis is immunologically mediated. Other viral diseases associated with joint inflammation include rubella, human immunodeficiency virus infection, coxsackieviral, and adenoviral infections.
[0037] An immune complex mediated joint inflammation is also associated with intestinal bypass surgery, and joint inflammation is a prominent manifestation of Whipple's disease, or intestinal lipodystrophy, where fever, edema, serositis, lymphadenopathy, uveitis, and cerebral inflammation are associated findings. Furthermore, potentially immunologically-related joint inflammation is an associated sequelum of infectious endocarditis and certain spirochetal infections, most notably infection with Borrelia burgdorferi, the causative organism of Lyme disease .
[0038] Primary Sjögrens syndrome is a chronic, slowly progressive autoimmune disease characterized by lymphocytic infiltration of the exocrine glands resulting in xerostomia and dry eyes. One-third of patients present with systemic manifestations, including vasculitis, nephritis, mononeuritis multiplex, and, most commonly, joint inflammation.
[0039] Ankylosing spondylitis (AS) is an inflammatory disorder of unknown cause that affects primarily the axial skeleton, but peripheral joints are also affected Its incidence correlates with the HLA-B27 histocompatibility haplotype, and immune-mediated mechanisms are further implicated by elevated serum levels of IgA and an inflammatory joint histology with similar characteristics to those seen in the joint inflammation aspects of RA. Thus, synovial fluid from inflammatory peripheral joints in AS is not distinctly different from that of other inflammatory joint diseases.
[0040] Reactive arthritis (ReA) refers to acute nonpurulent joint inflammation complicating an infection elsewhere in the body. Reactive arthritis is believed to be immunologically mediated. Included in this category is the constellation of clinical findings often referred to as Reiter's syndrome or Reiter's disease. In addition to joint inflammation, this syndrome affects the skin, eyes, mucous membranes, and less commonly the heart, lungs, and nervous system. Reiter's syndrome may follow enteric infections with any of several Shigella, Salmonella, Yersinia, and Campylobacter species, and genital infections with Chlamydia trachomatous. The histology of joints affected by this syndrome is similar to that seen in other types of joint inflammation. The joint inflammation is usually quite painful, and tense joint effusions are not uncommon, especially in the knee. The joint inflammation is usually asymmetric and additive, with involvement of new joints occurring over a period of a few clays to several weeks.
[0041] Current Therapies
[0042] Current therapies for the various types of joint inflammation discussed above include the administration of anti-inflammatory drugs such as non-steroidal drugs, including aspirin, and non-specific immunosuppressive drugs, such as gold compounds, corticosteroids, penicillamine, hydroxychloroquine, methotrexate, azathioprine, alkylating agents such as cyclophosphamide, and sulfasalazine. Administration of each of these agents is sometimes associated with severe side effects and toxicities. Patients receiving certain of these treatments are also exposed to the dangers of opportunistic infection and increased risk of neoplasia associated with generalized immunosuppression. In addition to the medical texts cited above, discussions of drugs used to treat established joint inflammation can be found in Goodman and Gilman's The Pharmacological Basis of Therapeutics 18th Ed., Gilman et al. (eds.) 1990, Pergamon Press, Inc., New York, Chapter 26, pp. 638-681; Physician's Desk Reference 47th Ed., 1993, Medical Economics Co., Inc., Montvale, N.J.; The United States Pharmacopeia 22nd Ed., 1989, Mack Printing Co., Easton, Pa.; Drug Evaluations Annual 1991, 1990, American Medical Association, Milwaukee, Wis.; and Cash and Klippel, 1994, N. Eng. J. Med. 330, pp. 1368-1375.
[0043] In addition to pharmacologic treatments, relief of the symptoms of joint inflammation is sometimes achieved with warm or cold soaks. Surgical intervention using tendon release procedures and/or joint replacement procedures is frequently the last resort for treatment of chronic joint inflammation. Such orthopedic surgery is associated with increased infection and prostheses have limited life spans.
[0044] New therapeutic approaches currently being developed include attempts to address various elements of the cellular immune response contributing to the inflammatory cascade present in inflamed joints. These approaches include the administration of therapeutic preparations including anti-T cell and/or anti-cytokine agents (see, for example, Banerjee et al., 1988A; Cannon et al., 1990; Chiocchia et al., 1991; Elliot et al., 1993; Fava et al., 1993; Fujimori et al., 1993; Griswold et al., 1988; Hom et al., 1988; Hom et al.. 1991; Hom et al., 1993; Inoue et al., 1993; Kakimoto et al., 1992; Kleinau et al., 1989; Myers et al., 1989b; Myers et al., 1993; Nagler-Anderson et al., 1986; Nishikaku and Koga, 1993; Peterman et al., 1993; Piguet et al., 1992; Smith et al,, 1990; Spannaus-Martin et al., 1990; Thompson et al., 1988; Trentham et al., 1993, Williams et al., 1992b; Williams et al., 1994; and Wolos et al., 1993).
SUMMARY OF THE INVENTION
[0045] In view of the foregoing, it is an object of the present invention to provide a new approach for treating established joint inflammation.
[0046] To achieve this goal, the invention provides methods involving the use of blockers of complement component C 5 as pharmaceutical agents to accomplish therapeutic treatment of established joint inflammation. The C 5 blockers are administered to animals, e.g., humans, having at least one inflamed joint. The blockers can be administered systemically or locally. They achieve a reduction or stabilization of the inflammation of joints that are already inflamed and inhibit the spread of inflammation to unaffected joints.
[0047] As used herein, a “C 5 blocker” is a compound that directly interacts with C 5 , C 5 a, and/or C 5 b, i.e., a compound that directly binds to or directly modifies (i.e., by a direct chemical reaction) one of these complement components, so as to inhibit the formation of and/or physiologic function of C 5 a and/or C 5 b. Preferably, the formation and/or physiologic functions of both C 5 a and C 5 b are inhibited by the C 5 blocker.
[0048] Direct interaction with C 5 , C 5 a, and/or C 5 b has the important advantage that other components of the complement cascade may be left intact. In particular, the opsonization functions associated with the activation of complement component C 3 by a C 3 convertase to yield C 3 a and C 3 b may be left intact allowing for continued clearance of foreign particles and substances from the body by the action of C 3 b. The most preferred C 5 blockers are those which are of this type, i.e. those that do not interfere with C 3 b function.
[0049] As demonstrated by the examples presented below, in accordance with the invention, it has been surprisingly found that treatment with C 5 blockers will arrest and, in many cases, at least partially reverse the disease process at an inflamed joint, while at the same time preventing progression of joint inflammation to non-affected joints. Given the prior understanding in the art regarding the role of the cellular immune system in joint inflammation (see above), one would not have expected that a C 5 blocker would have such a dramatic beneficial effect on established joint inflammation.
[0050] The accompanying figures, which are incorporated in and constitute part of the specification, illustrate certain aspects of the invention, and together with the description, serve to explain the principles of the invention. It is to be understood, of course, that both the figures and the description are explanatory only and are not restrictive of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0051] [0051]FIGS. 1 a - c are photomicrographs of joints stained with Hematoxylin and Eosin illustrating the use of a C 5 blocker to stop the progression of established joint inflammation . FIG. 1 a shows a paw joint from a normal mouse; FIG. 1 b shows an initially affected paw joint from a control treated mouse, where the joint exhibits extensive bone erosion with severe inflammatory cell infiltration and thickening of the synovial membrane; and FIG. 1 c shows an initially affected paw joint from a C 5 blocker treated mouse showing preserved joint structure with some degree of synovial membrane thickening and a surprising lack of polymorphonuclear cell infiltration compared with the initially affected joint from the control group (FIG. 1 b ).
[0052] [0052]FIGS. 2 a - b are plots demonstrating the ability of a C 5 blocker to stop the progression of pathology of an inflamed joint. FIG. 2 a shows a comparison of mean joint inflammation (JI) index values. Data represent mean JI index +/− standard error. Solid circles are C 5 blocker treated mice (n=6). Open circles are control treated mice (n=4). FIG. 2 b shows a comparison of paw thickness of initially affected joints. After onset of joint inflammation, control paw thickness increased significantly compared to treated or normal (N) paws. Data represent mean thickness +/− SE. Solid circles are C 5 blocker treated mice (n=8). Open circles are control treated mice (n=4).
[0053] [0053]FIGS. 3 a - e are plots of paw thickness versus time for C 5 blocker treated and control treated mice. FIGS. 3 a - d show measurements from initially affected paws of paired animals; FIG. 3 e shows measurements from initially affected paws of two unpaired treated animals and the mean control measurements of FIG. 2 b.
[0054] [0054]FIGS. 4 a - c are photomicrographs of joints stained with Hematoxylin and Eosin illustrating the use of a C 5 blocker to prevent the onset of joint inflammation. FIG. 4 a shows a paw joint from a normal mouse; FIG. 4 b shows an affected paw joint from a control treated mouse, where inflammatory cell infiltration, thickening of the synovial membrane and bone erosion by the expanding synovial pannus are visible; and FIG. 4 c shows a typical paw joint from a C 5 blocker treated mouse showing only subclinical thickening of the synovial membrane.
[0055] [0055]FIG. 5 shows that treatment with a C 5 blocker prevents joint inflammation. FIG. 5 a is a comparison of the incidence of Collagen-Induced joint inflammation in C 5 blocker treated mice (n=9) and in a pool of mice treated with two different control treatments (n=10). The data represent the overall (total) incidence of joint inflammation seen within two months after the initiation of treatment. FIG. 5 b is a comparison of serum hemolytic activity of C 5 blocker treated mice (n=5) and control treated mice (n=3) two weeks after the initiation of treatment.
[0056] [0056]FIG. 6 shows the effects of C 5 blocker treatment on collagen-specific humoral and cellular responses. FIG. 6 a was prepared by analyzing serum samples obtained from C 5 blocker treated (n=4) or control treated mice (n=4) at the indicated time after CII immunization. The samples were analyzed for anti B-CII IgG in an ELISA assay. The anti B-CII antibody index represents the ratio of optical densities obtained from positive serum and negative sera. FIG. 6 b was prepared by culturing lymph node T cells (5×10 5 ) in vitro with 20 μg/ml B-CII, C-CII, B-CI or medium only, in the presence of 5×10 5 of mitomycin C treated syngeneic spleen cells for a total of 4 days, following which the cells were pulsed with 3 H-thymidine, 18 hours before harvest.
[0057] [0057]FIG. 7 shows the results of hemolytic assays demonstrating inhibition of complement activity associated with human blood circulated through an extracorporeal circuit following treatment with a C 5 blocker. Assays were performed before the addition of the blocker or the commencement of the CPB circuit (“Pre Tx”) using undiluted blood (“undil”) and diluted blood (“dil”) as described in Example 4. Samples of diluted blood to which the blocker had been added (“Post Tx”) were assayed at the times indicated after starting the CPB circuit.
[0058] [0058]FIG. 8 shows the results of assays of levels of complement component C 3 a demonstrating that the generation of complement component C 3 a in whole human blood circulated through an extracorporeal circuit is not inhibited by the addition of a C 5 blocker to such whole blood. Assays were performed before the addition of the blocker or the commencement of the CPB circuit (“Pre Tx”) using undiluted blood (“undil”) and diluted blood (“dil”) as described in Example 5. Samples of diluted blood to which the blocker had been added (“Post Tx”) were assayed at the times indicated after starting the CPB circuit.
[0059] [0059]FIG. 9 shows the results of assays of the levels of soluble C 5 b - 9 (sC 5 - b - 9 ) in human blood circulated through an extracorporeal circuit demonstrating that the addition of a C 5 blocker to such whole blood inhibits the formation of the C 5 b - 9 terminal complement assembly. Assays were performed before the addition of the blocker or the commencement of the CPB circuit (“Pre Tx”) using undiluted blood (“undil”) and diluted blood (“dil”) as described in Example 6. Samples of diluted blood to which the blocker had been added (“Post Tx”) were assayed at the times indicated after starting the CPU circuit.
[0060] [0060]FIGS. 10 a - b show pharmacokinetic analyses of the reduction of the cell lysis ability of mouse blood (FIG. 10 a ) or extracorporeally circulating human blood (FIG. 10 b ) after treatment with various C 5 blockers. C 5 Blocker B is monoclonal antibody BB 5 . 1 ; C 5 Blocker F is an Fab′ fragment of monoclonal antibody BB 5 . 1 ; C 5 Blocker N is monoclonal antibody N 19 - 8 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0061] As discussed above, the present invention relates to a method for treating established joint inflammation by the administration of a C 5 blocker or a combination of C 5 blockers to a patient in need of such treatment. As used herein, “established joint inflammation” means that the patient has at least one inflamed joint at the time treatment is commenced.
[0062] Such C 5 blockers comprise proteins (including antibodies), peptides, and other molecules that directly interact with C 5 , C 5 a, and/or C 5 b, so as to inhibit the formation of and/or physiologic function of C 5 a and/or C 5 b. Examples of non-protein molecules of this type include K-76 COOH, (see Hong et al., 1979), and substituted dihydrobenzoturans, spirobenzofuran-2(3H)-cycloalkanes, and their open chain intermediates, (see Sindelar et al,, U.S. Pat. No. 5,173,499), that are reported to directly interact with C 5 , C 5 a, and/or C 5 b. Preferably, the C 5 blocker or blockers inhibit the formation of and/or physiologic function of both C 5 a and C 5 b.
[0063] The concentration and/or physiologic activity of C 5 a and C 5 b in a body fluid can be measured by methods well known in the art. For C 5 a such methods include chemotaxis assays, RIAs, or ELISAs (see, for example, Ward and Zviaifler, 1971; Jose et al., 1990; Wurzner et al., 1991). For C 5 b, hemolytic assays or assays for soluble C 5 b - 9 as discussed herein can be used. Other assays known in the art can also be used. Using assays of these or other suitable types, candidate C 5 blockers, now known or subsequently identified, can be screened in order to 1) identify compounds that are useful in the practice of the invention and 2) determine the appropriate dosage levels of such compounds. Examples 2, 4, and 6-8 illustrate the use of hemolytic and soluble C 5 b - 9 assays with C 5 blockers comprising monoclonal antibodies.
[0064] Blockers affecting C 5 a are preferably used at concentrations providing substantial reduction (i.e., reduction by at least about 25%) in the C 5 a levels present in at least one blood-derived fluid of the patient, e.g., blood, plasma, or serum, following activation of complement within the fluid. Alternatively, they are used at concentrations providing at least about a 10% reduction in the C 5 a levels present in the synovial fluid of an inflamed joint.
[0065] Similarly, blockers affecting C 5 b are preferably used at concentrations providing substantial reduction (i.e., reduction by at least about 25%) in the C 5 b levels present in at least one blood-derived fluid of the patient following activation of complement within the fluid. Alternatively, they are used at concentrations providing at least about a 10% reduction in the C 5 b levels present in the synovial fluid of an inflamed joint. In the case of C 5 b, such concentrations can be conveniently determined by measuring the cell-lysing ability (e.g., hemolytic activity) of complement present in the fluid or the levels of soluble C 5 b - 9 present in the fluid (see, for example, Example 6 below). Accordingly, a preferred concentration for a C 5 blocker that affects C 5 b is one that results in a substantial reduction (i.e., a reduction by at least about 25%) in the cell-lysing ability of the complement present in at least one of the patient's blood-derived fluids. Reductions of the cell-lysing ability of complement present in the patient's body fluids can be measured by methods well known in the art such as, for example, by a conventional hemolytic assay such as the hemolysis assay described by Kabat and Mayer, 1961, pages 135-139, or a conventional variation of that assay such as the chicken erythrocyte hemolysis method described below.
[0066] Preferred C 5 blockers are relatively specific, and do not block the functions of early complement components. In particular, such preferred agents will not substantially impair the opsonization functions associated with complement component C 3 b, which functions provide a means for clearance of foreign particles and substances from the body.
[0067] C 3 b is generated by the cleavage of C 3 , which is carried out by classical and/or alternative C 3 convertases, and results in the generation of both C 3 a and C 3 b. Therefore, in order not to impair the opsonization functions associated with C 3 b, preferred C 5 blockers do not substantially interfere with the cleavage of complement component C 3 in a body fluid of the patient (e.g., serum) into C 3 a and C 3 b. Such interference with the cleavage of C 3 can be detected by measuring body fluid levels of C 3 a and/or C 3 b, which are produced in equimolar ratios by the actions of the C 3 convertases. Such measurements are informative because C 3 a and C 3 b levels will be reduced (compared to a matched sample without the C 5 blocker) if cleavage is interfered with by a C 5 blocker.
[0068] In practice, the quantitative measurement of such cleavage is generally more accurate when carried out by the measurement of body fluid C 3 a levels rather than of body fluid C 3 b levels, since C 3 a remains in the fluid phase whereas C 3 b is rapidly cleared. C 3 a levels in a body fluid can be measured by methods well known in the art such as, for example, by using a commercially available C 3 a EIA kit, e.g., that sold by Quidel Corporation, San Diego, Calif., according to the manufacturers specifications. Particularly preferred C 5 blockers produce essentially no reduction in body fluid C 3 a levels following complement activation when tested in such assays.
[0069] Preferred C 5 blocking agents include antibodies. The antibodies are preferably monoclonal, although polyclonal antibodies, which can be produced and screened by conventional techniques, can also be used if desired. Hybridomas producing monoclonal antibodies (mAbs) reactive with complement component C 5 can be obtained using complement component C 5 , C 5 a, and/or C 5 b, preferably in purified form, as the immunogen.
[0070] The most preferred antibodies will prevent the cleavage of C 5 to form C 5 a and C 5 b, thus preventing the generation of the anaphylatoxic activity associated with C 5 a and preventing the assembly of the membrane attack complex associated with C 5 b. As discussed above, in a particularly preferred embodiment, these C 5 blocking antibodies will not impair the opsonization function associated with the action of C 3 b.
[0071] General methods for the immunization of animals (in this case with C 5 , C 5 a, and/or C 5 b ), isolation of antibody producing cells, fusion of such cells with immortal cells (e.g., myeloma cells) to generate hybridomas secreting monoclonal antibodies, screening of hybridoma supernatants for reactivity of secreted monoclonal antibodies with a desired antigen (in this case the immunogen or a molecule containing the immunogen), the preparation of quantities of such antibodies in hybridoma supernatants or ascites fluids, and for the purification and storage of such monoclonal antibodies, can be found in numerous publications. These include: Coligan, et al., eds. Current Protocols In Immunology, John Wiley & Sons, New York, 1992; Harlow and Lane, Antibodies, A Laboratory Manual. Cold Spring Harbor Laboratory, New York, 1988; Liddell and Cryer, A Practical Guide To Monoclonal Antibodies, John Wiley & Sons, Chichester, West Sussex, England, 1991; Montz, et al., Cellular Immunol, 127:337-351, 1990; Wurzner, et al., Complement Inflamm. 8:328-340, 1991; and Mollnes, et al., Scand. J. Immunol. 28:307-312, 1988.
[0072] A description of the preparation of a mouse anti-human-C 5 monoclonal antibody with preferred binding characteristics is presented below in Example 8. Wurzner, et al., 1991, describe the preparation of other suitable mouse anti-human-C 5 monoclonal antibodies referred to as N 19 - 8 and N 20 - 9 .
[0073] As used herein, the terms “antibody” or “antibodies” refer to immunoglobulins produced in vivo, as well as those produced in vitro by a hybridoma, and antigen binding fragments (e.g., Fab′ preparations) of such immunoglobulins, as well as to recombinantly expressed (engineered) antigen binding proteins, including immunoglobulins, chimeric immunoglobulins, “humanized” immunoglobulins, antigen binding fragments of such immunoglobulins, single chain antibodies, and other recombinant proteins containing antigen binding domains derived from immunoglobulins. As used herein, the term “monoclonal” refers to any antibody that is not of polyclonal origin.
[0074] Publications describing methods for the preparation of engineered antibodies, in addition to those listed immediately above, include: Reichmann, et al., Nature, 332:323-327, 1988; Winter and Milstein, Nature, 349:293-299, 1991; Clackson, et al., Nature, 352:624-628, 1991, Morrison, Annu Rev Immunol, 10:239-265, 1992; Haber, Immunol Rev, 130:189-212, 1992; and Rodrigues, et al., J Immunol, 151:6954-6961, 1993. Human or humanized antibodies are preferred for administration to human patients.
[0075] To achieve the desired reductions of body fluid parameters, such anti-C 5 antibodies can be administered in a variety of unit dosage forms. The dose will vary according to the particular antibody. For example, different antibodies may have different masses and/or affinities, and thus require different dosage levels. Antibodies prepared as Fab′ fragments or single chain antibodies will also require differing dosages than the equivalent native immunoglobulins, as they are of considerably smaller mass than native immunoglobulins, and thus require lower dosages to reach the same molar levels in the patient's blood.
[0076] Dosage levels of the antibodies for human subjects are generally between about 0.5 mg per kg and about 100 mg per kg per patient per treatment, and preferably between about 1 mg per kg and about 50 mg per kg per patient per treatment. In terms of body fluid concentrations, the antibody concentrations are preferably in the range from about 5 μg/ml to about 500 μ/ml.
[0077] Other C 5 blockers can also be administered in a variety of unit dosage forms and their dosages will also vary with the size, potency, and in vivo half-life of the particular C 5 blocker being administered.
[0078] Doses of C 5 blockers will also vary depending on the manner of administration, the particular symptoms of the patients being treated, the overall health, condition, size, and age of the patient, and the judgment of the prescribing physician.
[0079] Subject to the judgement of the physician, a typical therapeutic treatment includes a series of doses, which will usually be administered concurrently with the monitoring of clinical endpoints such as number of joints involved, redness of joints, swelling of joints, mobility of joints, pain levels, etc., with the dosage levels adjusted as needed to achieve the desired clinical outcome.
[0080] The frequency of administration may also be adjusted according to various parameters. These include the clinical response, the plasma half-life of the C 5 blocker, and the levels of the blocker in a body fluid, such as, blood, plasma, serum, or synovial fluid. To guide adjustment of the frequency of administration, levels of the C 5 blocker in the body fluid may be monitored during the course of treatment.
[0081] Alternatively, for C 5 blockers that affect C 5 b, levels of the cell-lysing ability of complement present in one or more of the patient's body fluids are monitored to determine if additional doses or higher or lower dosage levels are needed. Such doses are administered as required to maintain at least about a 25% reduction, and preferably about an 50% or greater reduction of the cell-lysing ability of complement present in blood, plasma, or serum, or at least about a 10% reduction of the cell-lysing ability of complement present in synovial fluid from an inflamed joint. The cell-lysing ability can be measured as percent hemolysis in hemolytic assays of the types described herein. A 10% or 25% or 50% reduction in the cell-lysing ability of complement present in a body fluid after treatment with the C 5 blocker or blockers used in the practice of the invention means that the percent hemolysis after treatment is 90, 75, or 50 percent, respectively, of the percent hemolysis before treatment.
[0082] In yet another alternative, dosage parameters are adjusted as needed to achieve a substantial reduction of C 5 a levels in blood, plasma, or serum, or at least a 10% reduction of the C 5 a levels in the synovial fluid of an inflamed joint as discussed above, C 5 a levels can be measured using the techniques described in Wurzner, et al., Complement Inflamm 8:328-340, 1991. Other protocols of administration can, of course, be used if desired as determined by the physician.
[0083] In a preferred embodiment, administration of the C 5 blocker is initiated when the patient experiences a “flare up” of joint inflammation in which one or more affected joints becomes more swollen and takes on an erythematous (reddened) appearance.
[0084] Administration of the C 5 blockers will generally be performed by a parenteral route, typically via injection such as intra-articular or intravascular injection (e.g., intravenous infusion) or intramuscular injection. Other routes of administration, e.g., oral (p.o.), may be used if desired and practicable for the particular C 5 blocker to be administered.
[0085] For the treatment of established joint inflammation by systemic administration of a C 5 blocker (as opposed to local administration, e.g., intra-articular injection into the inflamed joint) administration of a large initial dose is preferred, i.e., a single initial dose sufficient to yield a substantial reduction, and more preferably an at least about 50% reduction, in the hemolytic activity of the patient's serum. Such a large initial dose is preferably followed by regularly repeated administration of tapered doses as needed to maintain substantial reductions of serum hemolytic titer. In another embodiment, the initial dose is given by both local and systemic routes, followed by repeated systemic administration of tapered doses as described above.
[0086] Formulations suitable for injection, p.o., and other routes of administration are well known in the art and may be found, for example, in Remington's Pharmaceutical Sciences, Mack Publishing Company, Philadelphia, Pa., 17th ed. (1985). Parenteral formulations must be sterile and non-pyrogenic, and generally will include a pharmaceutically effective carrier, such as saline, buffered (e.g., phosphate buffered) saline, Hank's solution, Ringer's solution, dextrose/saline, glucose solutions, and the like. These formulations may contain pharmaceutically acceptable auxiliary substances as required, such as, tonicity adjusting agents, wetting agents, bactericidal agents, preservatives, stabilizers, and the like.
[0087] The formulations of the invention can be distributed as articles of manufacture comprising packaging material and a pharmaceutical agent which comprises the C 5 blocker or blockers and a pharmaceutically acceptable carrier as appropriate to the mode of administration. The packaging material will include a label which indicates that the formulation is for use in the treatment of joint inflammation and may specifically refer to arthritis, rheumatoid arthritis, osteoarthritis, lupus arthritis, psoriatic arthritis, juvenile onset rheumatoid arthritis, reactive arthritis, Reiter's syndrome (Reiter's disease), or other diseases involving joint inflammation.
[0088] Without intending to limit it in any manner, the present invention will be more fully described by the following examples. The methods and materials which are common to various of the examples are as follows.
MATERIALS AND METHODS
[0089] Cell Lysis Assays
[0090] The cell-lysing ability or complement in various body fluid samples was determined using hemolytic assays performed as follows: Chicken erythrocytes were washed well in GVBS (Sigma Chemical Co. St. Louis, Mo., catalog No. G-6514) and resuspended to 2×10 8 /ml in GVBS. Anti-chicken erythrocyte antibody (IgG fraction of anti-chicken-RBC antiserum, Intercell Technologies, Hopewell, N.J.) was added to the cells at a final concentration of 25 μg/ml and the cells were incubated for 15 min. at 23° C. The cells were washed 2× with GVBS and 5×10 6 cells were resuspended to 30 μL in GVBS. A 100 μL volume of body fluid test solution was then added to yield a final reaction mixture volume of 130 μL. As used herein, reference to the serum percentage and/or serum input in these assays indicates the percent of a body fluid (including serum, as well as other body fluids such as blood, plasma, or synovial fluid) in the 100 μL volume of body fluid test solution.
[0091] After incubation for 30 min. at 37° C., percent hemolysis was calculated relative to a fully lysed control sample. Hemolysis was determined by spinning the cells down and measuring released hemoglobin in the supernatant as the optical density at 41 nm.
[0092] A 50% reduction in hemolysis after treatment with the C 5 blocker or blockers used in the practice of the invention means that the percent hemolysis after treatment was one half of the percent hemolysis before treatment.
[0093] Various hemolytic assays described below in the examples were performed using this chicken erythrocyte assay with the following body fluid inputs. For assays of mouse complement activity, the 100 μL volume of body fluid test solution contained 50 μL of diluted (in GVBS) mouse serum and 50 μL of human C 5 deficient serum (Quidel Corporation, San Diego, Calif.). For assays of human complement activity, the body fluid test solution contained various concentrations of human plasma or serum, with hybridoma supernatants and/or GVBS being added to yield the final 100 μL volume. For the assays used to screen hybridoma supernatants discussed below in example 8 each 100 μL volume of serum test solution contained 50 μL of hybridoma supernatant and 50 μL of a 10% solution of human serum in GVBS, yielding a 5% human serum input.
[0094] Collagen Induced Joint Inflammation
[0095] Examples 1, 2, and 3 use a collagen induced joint inflammation system that has been employed since the 1970s as an animal model of human joint inflammation, particularly RA (see, for example, Trentham et al., 1977; Holmdahl et al, 1986; Boissier et al, 1987; Yoo et al., 1988). This model system was implemented using 8-12 week old male DBA/1LacJ mice that were purchased from The Jackson Laboratory (Bar Harbor, Me.).
[0096] Immunization
[0097] Bovine collagen II (B-CII) obtained from Elastin Products Company, Inc., Owensville, Mo., was dissolved in 0.01 M acetic acid by stirring overnight at 4° C. at a concentration of 4 mg/ml. Complete Freund's adjuvant (CFA) was prepared by the addition of desiccated Mycobacterium tuberculosis H37RA (Difco, Detroit, Mich.) to incomplete Freunds adjuvant (Difco) at a concentration of 2 mg/ml. The solution of B-CII was emulsified in an equal volume of CPA and a 100 μl aliquot of this emulsion, containing 200 μg B-CII and 100 μg of Mycobacterium, was injected intradermally at the base of the mouse's tail. After 21 days, all mice were reimmunized using the identical protocol. This secondary CII reimmunization served primarily to boost the serum levels of anti-CII antibodies in the immunized mice. After CII reimmunization, the onset of joint inflammation (JI) and disease progression rise dramatically, characterized by the severe swelling and redness of the joints of one or more paws at around 4-6 weeks after the initial immunization.
[0098] Clinical evaluation
[0099] Mice were examined daily beginning on the day of reimmunization for the appearance of JI. The presence of JI was determined by examining, measuring and scoring each of the forepaws and hindpaws. Collagen induced JI (CIJI) is characterized by swelling and erythema or visible joint distortion of one or more extremities. The severity of JI in each affected paw was scored as: 0—normal joint; 1—visible redness and swelling; 2—severe redness and swelling affecting entire paw or joint; or 3—deformed paw or joint with ankylosis. The sum of the scores for all four paws in each mouse was used as an index (the “JI index”) to assess overall disease severity and progression.
[0100] Anti-complement Monoclonal Antibodies
[0101] Monoclonal antibodies that bind to and block mouse C 5 were prepared by standard methods from hybridoma BB 5 . 1 (Frei, et al., 1987), which was: obtained from Dr. Brigitta Stockinger of the National Institute for Medical Research, Mill Hill, London, England. Anti-human C 8 hybridoma, 135.8, which generates an Mab that does not block mouse C 8 , was obtained from Dr. Peter Sims (Blood Research Institute, Milwaukee, Wis.). Both antibodies are IgG1 isotypes, and ascites of BB5.1 or 135.8 were obtained in athymic nude mice or BALB/c mice, respectively. IgGs were purified from ascites with a protein A affinity collum eluted with acetic acid, and subsequently dialyzed against PBS. Purified antibodies were quantified by spectrophotometric determination of absorbance at 280 nm and sterilized with a 0.22 μm filter.
[0102] Antibody administration
[0103] For prophylactic treatment, mice were randomly divided as C 5 blocker treated and control treated groups and subsequently received 75 μg per mouse ip doses of either anti-mouse C 5 mab, BB 5 . 1 , or anti-human C 5 mAb, 135.8, as a control, twice weekly. For therapeutic treatment of established JI, mice received anti-mouse C 5 mAb BB 5 . 1 or anti-human C 8 mAb 135.8 at 2-5 mg/mouse ip daily for 10 days after the initial onset of JI was observed. The doses of anti-C 5 mAb were adjusted in a range spanning 2 mg to 5 mg per injection to ensure that the desired depletion of C 5 mediated hemolytic activity was obtained, i.e., a depletion of at least 50%.
[0104] Unlike the situation in humans, where administration of a C 5 blocker to a body fluid of genetically unrelated individuals results in roughly equivalent levels of complement inhibition, the dose of anti-murine-C 5 mAb required to deplete hemolytic activity by a given amount in mice is strain dependent. The dose required to deplete hemolytic activity in DBA/1LacJ mice is approximately four times higher than the dose required to achieve an equivalent depletion of the hemolytic activity in BALB/c mice.
[0105] T cell stimulation assays
[0106] Lymph node cells taken from animals at the time of sacrifice were analyzed for specific T cell responses to collagen II. T cells (5×10 5 ) were incubated with 5×10 5 mitomycin C (50 μg/ml) treated syngeneic spleen cells from normal DBA/1LacJ mice in flat bottomed 96-well plates, Bovine collagen II (B-CII), bovine CI (B-CI), chicken CII (C-CII) and ovalbumin or BSA were added to cultures at 20 μg/ml. The culture medium was RPMI-1640 supplemented with 5% heated inactivated FC 5 , 5×10 −5 M 2-ME, 10 mM HEPES buffer, 1% L-glutamine, 1% sodium pyruvate, and 1% penstrep. The cultures were incubated at 37° C. in 5% CO 2 for 4 days. Eighteen hours before harvesting, 1 μci of 3 H-thymidine was added to each well. Results are expressed as cpm obtained from triplicate T cell cultures.
[0107] Quantification of anti B-CII antibodies
[0108] Mice were bled at various times after immunization with B-CII. Serum anti B-CII antibody titers were measured using a conventional ELISA for B-CII similar to the ELISA for anti C 5 antibodies described below in Example 8, but using B-CII to coat the plates (also see Myers, et al., 1989, and Seki et al., 1992, for descriptions of similar assays).
[0109] Histological examination
[0110] Mice from each group were sacrificed and all four legs from each mouse were fixed in 10% buffered formalin and decalcified in a solution of 3.1% HCL, 5% formic acid and 7% aluminum chloride. The tissue samples were embedded in paraffin, sectioned at 5 μm and stained with hematoxylin and eosin. For immunofluorescence staining, paws were decalcified in a 0.1 M Tris solution containing 10% EDTA and 7 5% PVP for 3 days and frozen in OCT at −80° C. 5 μm sections were then prepared and stained with 9FITC conjugated goat anti-mouse IgG, IgA, and IgM (Zymed Laboratories, South San Francisco, Calif., Catalog No. 65-6411) at a dilution of 1 to 50.
EXAMPLE 1
Therapeutic Effects of C 5 Blocker Treatment after the
Clinical Onset of Collagen Induced Joint Inflammation
[0111] In order to assess the effects of administration of a C 5 blocker on established JI, mice were observed following induction of CIJI, as described above, and pairs of mice were selected that showed the initial appearance of readily detectable JI symptoms (swollen joints of the paws) on the same day. One mouse of each such pair was treated with a anti-C 5 mAb BB 5 . 1 and one was treated with a control injection of either the irrelevant mAb 135.8 or PBS. In each matched pair, the animal with the greatest overall level of paw inflammation was assigned to the C 5 blocker treatment group so as to avoid potentially biasing the results in favor of the C 5 blocker treatment. Starting on the first day when joint inflammation was observed as paw inflammation, treatments were continued daily for 10 days (In one case a pair of mice was only carried for 8 days.) In addition to these matched pairs, two unpaired animals also received the C 5 blocker treatment after the induction of JI.
[0112] Histological examination of initially affected joints from control-treated mice at the end of the treatment period revealed extensive bone erosion with severe inflammatory cell infiltration, thickening of the synovial membranes, and pannus formation (FIG. 1 b ). In contrast, the initially affected joints of the C 5 blocker treated group showed preserved joint structure with some degree of thickening of synovial membranes and mononuclear cell infiltration into some of the joints (FIG. 1C). The severe inflammatory cell infiltration in the control-treated joints was predominantly made up of polymorphonuclear cells (PMNs, neutrophils). Surprisingly, such PMN infiltration was almost completely absent in the C 5 blocker treated mice.
[0113] During the clinical course of CIJI, an important indicator of the progression of disease is the involvement of additional limbs. Therefore, the number of limbs with clinically detectable JI at the end of the treatment period was compared with the number of limbs exhibiting JI symptoms before the start of therapy. The severity and progression of JI in each affected paw was determined and scored as described above under the heading “Materials and Methods”, and the sum of the scores for all four paws of each animal was used as a “JI index”. The thicknesses of all four paws of each animal were also measured with a caliper during the time of this experiment to provide a completely objective evaluation of this aspect of disease progression.
[0114] As shown in Table 1 (mean values) and Table 2 (individual values), there were significant increases in new limb involvement in the control treated group during the course of 10 day treatment, while the number of inflamed limbs was decreased when DBA/1LacJ mice with inflamed joints were treated with the C 5 blocker starting at the time of disease onset. In addition to new limb recruitment, the initially affected paws of the control treated animals evidenced progression of inflammatory joint disease severity by becoming more inflamed (FIG. 2 a. Acute inflammation in the affected joints was observed as severe joint swelling and redness during the first few days, followed by joint deformation and ankylosis at the end of 10 day period. In contrast, no new paws were involved and the severity of inflammation in the majority of affected joints subsided or reined unchanged during the course of C 5 blocker therapy (FIG. 2 a ).
[0115] The paw thicknesses of initially affected limbs in both C 5 blocker treated and control treated groups during the course of these experiments is shown as mean values for each group in FIG. 2 b. FIGS. 3 a, 3 b, 3 c, and 3 d show values for each initially inflamed paw of each of the matched pairs of control treated and C 5 blocker treated animals, while FIG. 3 e shows the values obtained for each initially inflamed paw of each of the unpaired C 5 blocker treated animals (shown along with the mean values for control treated animals of FIG. 2 b ). In these figures, the number in parenthesis indicates the designation of the particular animal, while the letters following the numbers (only in those cases where more than one limb was affected initially) indicate the particular paws affected, with the first letter indicating front (F) or rear (R) paws, and the second letter indicating right (R) or left (L) paws.
[0116] As can be seen in FIGS. 2 and 3, and in Tables 1 and 2, C 5 blocker treatment successfully prevented further paw recruitment and reduced (but did not completely abolish) the inflammation in the initially affected joints in all but one (mouse #4) of the C 5 blocker treated animals. As can be seen in FIG. 2 b, the mean thickness of initially affected paws in the control treated group increased significantly during the 10 day period, while the mean thickness of initially affected paws in the C 5 blocker treated group decreased, but not significantly.
EXAMPLE 2
Prophylactic Treatment with a C 5 Blocker Prevents
Collagen Induced Joint Inflammation
[0117] In these experiments, the administration of the C 5 blocker coincided with the reimmunization of the experimental animals with B-CII. On the day of reimmunization, mice were symptom free, and were randomly assigned to C 5 blocker treatment or control treatment groups. Each mouse was treated with either the C 5 blocker (anti-mouse C 5 mAb, BB 5 . 1 ) or a control treatment (anti-human C 8 mab, 135.8) at 750 μg per mouse ip twice weekly. The animals were treated for four weeks, at which time treatment was discontinued. The results of this study are shown in FIGS. 4 and 5.
[0118] Administration the C 5 blocker completely prevented the development of CIJI ( 0 / 8 ). All mice in the C 5 blocker treated group exhibited no signs of clinical disease during the period of treatment (and for up to two months after discontinuing the C 5 blocker therapy in the two animals followed for that long). In contrast, 90% of the control treated animals ( 9 / 10 ) developed JI by 4-6 weeks after the first B-CII immunization. The percent incidence of JI observed in the control treated and C 5 blocker treated animals after 4-6 weeks is plotted in FIG. 5 a. (Note that the value for the C 5 blocker treated group in this figure is actually 0%, but a bar indicating 1% has been plotted in order to indicate that the data for this set of animals was obtained and is presented.) Peak inflammation levels were observed around 5 weeks after the initial collagen immunization. As shown in FIG. 5 b, 80% to 90% of the serum hemolytic activity was depleted in the C 5 blocker treated group, while the serum hemolytic activity remained normal in the control treated group.
[0119] As shown in FIG. 4, histological examination of affected Joints from control mice revealed extensive mononuclear cell as well as polymorphonuclear cell infiltration, thickening of the synovial membrane and bone erosion by the expanding synovial pannus (FIG. 4 b ). In contrast, there were no signs of inflammatory processes observed in the majority of joints studied from the C 5 blocker treated mice. A few joints from these C 5 blocker treated mice showed some subclinical thickening of the synovial membrane, but this alteration was not accompanied by any visible bone erosion or inflammatory cell infiltration (FIG. 4 c ). Interestingly, immunofluorescence staining showed antibody deposition along cartilage surfaces and C 3 activation at synovial membranes in the joints of both the control treated and the C 5 blocker treated animals.
EXAMPLE 3
Effect of C 5 Blocker Treatment on the Humoral and
Cellular Immune Responses to Immunization with Collagen
[0120] Responses of both the humoral and cellular immune systems are activated after immunization of DBA/1LacJ mice with bovine Collagen II. Anti B-CII titers increase, and the serum IgG anti B-CII titers in C 5 blocker treated mice are equivalent to those of control treated mice when tested at 14, 28 and 42 days after the initial B-CII immunization (FIG. 6 a ). Anti B-CII antibody titers from both control and anti-C 5 mab treated mice rise significantly after the B-CII reimmunization and remain at the resulting plateau for an extended period of time.
[0121] In order to study T cell responses, lymph node cells (LNCs) from C 5 blocker treated mice and control treated mice were cultured with either B-CII, B-CI, C-CII, or culture medium only. LNCs from either C 5 blocker treated mice or control treated mice responded specifically and equally to B-CII regardless of the treatment the animals received concurrently with B-CII reimmunization. C-CII, which shares many conserved regions of homology with B-CII also elicited a moderate T cell response when cultured with LNCs from C 5 blocker treated mice or from control treated mice. In contrast, LNCs from age matched non-immunized mice responded poorly to all of the tested collagens (FIG. 6 b ).
[0122] The data obtained in these experiments and those of Examples 1 and 2 clearly demonstrate that in vivo administration of a C 5 blocker prevents the development and progression of CIJI and that this treatment does not interfere with the humoral and cellular immune responses seen after immunizing mice with bovine type II collagen. Both collagen-specific T cell responses and anti-CII antibody titers were comparable in both the C 5 blocker treated mice and the control treated B-CII reimmunized mice.
EXAMPLE 4
C 5 Blocker Inhibition of Complement Activity
[0123] The effects of a C 5 blocker on complement activation were evaluated using a closed-loop cardio-pulmonary bypass (CPB) model for the extracorporeal circulation of human blood. As discussed fully in copending U.S. patent application Ser. No. 08/217,391, filed Mar. 23, 1994, extracorporeal circulation of human blood causes activation of complement in the blood.
[0124] The C 5 blocker was a monoclonal antibody raised in mice against purified human C 5 protein (Wurzner, et al., Complement Inflamm 8:328-340, 1991; mAb N19-8) that was propagated, recovered and purified as an IgG fraction from mouse ascites fluid ( Antibodies, A Laboratory Manual, Cold Spring Harbor Laboratory, New York, 1988; Current Protocols In Immunology, John Wiley & Sons, New York, 1992).
[0125] To carry out these experiments, 300 ml of whole human blood was drawn from a healthy human donor and additionally a 1 ml sample was removed as a control sample for later analysis. The blood was diluted to 600 ml by the addition of Ringer's lactate solution containing 10 U/ml heparin. The C 5 blocker (30 mg in sterile PBS) was added to the diluted blood to a final concentration of 50 μg/ml. In a control experiment, an equal volume of sterile PBS was added to the diluted blood. The blood was then used to prime the extracorporeal circuit of a COBE CML EXCEL membrane oxygenator CPB machine (Cobe BCT, Inc., Lakewood, Colo.) and the circuit was started. The circuit was cooled to 28° C. and circulated for 60 minutes. The circuit was then warmed to 37° C. and circulated for an additional 30 minutes. The experiment was then terminated. Samples were taken at several time points and evaluated for complement activity (FIG. 7).
[0126] At each time point an aliquot of whole blood was taken, divided into 3 samples and A) diluted 1:1 in 2% paraformaldehyde in PBS to evaluate platelet and blood cell activation parameters as discussed in the above-referenced U.S. patent application Ser. No. 08/217,391; B) centrifuged to remove all cells and plasma diluted 1:1 in Quidel sample preservation solution (Quidel Corporation, San Diego, Calif.) and stored at −80° C., following which these frozen diluted plasma samples were thawed and used to evaluate C 3 a and C 5 b - 9 generation (Examples 5 and 6, respectively), and C) centrifuged to remove all cells and undiluted plasma stored at −80° C., following which these frozen plasma samples were thawed and hemolytic assays were performed as described above.
[0127] As can be seen in FIG. 7, addition of the C 5 blocker to the extracorporeal circuit resulted in a 95% reduction of the cell-lysing ability of complement in the plasma. The complement activity remained inhibited throughout the course (90 minutes) of the experiment.
EXAMPLE 5
Generation of C 3 a in the Presence of a C 5 Blocker
[0128] The fresh frozen plasma samples that had previously been diluted in Quidel sample preservation solution following CPB circulation (see Example 4) were assayed for the presence of the complement split product C 3 a by using the Quidel C 3 a ETA kit (Quidel Corporation, San Diego, Calif.). These measurements were carried out according to the manufacturer's specifications. C 3 a released is expressed in ng/well as determined by comparison to a standard curve generated from samples containing known amounts of human C 3 a.
[0129] As seen in FIG. 8, addition of the C 5 blocker had no effect on the production of C 3 a during the CPB experiment. C 3 a generation was dramatically increased during the final 30 min of the experiment and correlates with sample warming.
EXAMPLE 6
Prevention of the Generation of C 5 b - 9 by a C 5 Blocker
[0130] Fresh frozen plasma samples that had been previously diluted in Quidel sample preservation solution following CPB circulation (see Example 4) were assayed for the presence of the terminal human complement complex C 5 b - 9 using the Quidel C 5 b - 9 kit (Quidel Corporation, San Diego, Calif.). The amount of soluble C 5 b - 9 (sC 5 b - 9 ) in each sample was determined using the manufacturers specifications and is expressed in arbitrary absorbance units (AU).
[0131] As can be seen in FIG. 9, the C 5 blocker completely inhibited C 5 b - 9 generation during extracorporeal circulation so that sC 5 b - 9 levels during the full course of the run were equivalent to control (t 0 ) time points. The results of this experiment and those of Examples 4 and 5 show that the addition of a C 5 blocker to human blood undergoing extracorporeal circulation effectively inhibits both complement hemolytic activity (FIG. 7) and C 5 b - 9 generation (FIG. 9), but not C 3 a generation (FIG. 8).
EXAMPLE 7
Pharmacokinetics of mAb C 5 Blockers
[0132] The in vivo duration of action of mAb BB 5 . 1 , and a Fab′ fragment of mAb BB 5 . 1 (prepared by standard methods) was determined in normal female BALB/cByJ mice (averaging approximately 20 gms each) which were obtained from the Jackson Laboratory, Bar Harbor, Me. The mice were given a single intravenous injection (at 35 mg/kg body weight) of the mAb or the Fab′ fragment of the mAb (or an equal volume of PBS as a control). Blood samples were collected from the retroorbital plexus at 1, 4, 24, 96, and 144 hours after administration of PBS; 4, 16, and 24 hours after administration of the Fab′ fragment of mAb BB 5 . 1 ; and 4, 24, 48, 72, 96, and 144 hours after administration of intact mAb BB 5 . 1 .
[0133] [0133]FIG. 10 a shows the time course of inhibition of the cell-lysing ability of complement in mouse blood (determined by testing serum obtained from the blood and diluted to 2.5% in hemolytic assays, as described above) after the in vivo administration of the intact mAb, the Fab′ fragment, or the PBS. As shown in the figure, the intact mAb almost completely inhibited the hemolytic activity of the blood throughout the 6 day test period. The Fab′, however, had a half-life of approximately 24 hours.
[0134] In addition to the above experiments, at the end of the 6 day testing period all of the mice were sacrificed. Kidneys, lungs, and livers were harvested and examined by gross inspection, as well as by microscopic examination of stained sections. All of the organs of the C 5 blocker treated animals appeared the same as those taken from the PBS control treated animals. The overall appearance of these test and control mice was also indistinguishable prior to necropsy.
[0135] An anti-human C 5 mAb was also tested for pharmacokinetic properties in circulating human blood as described above in Example 4. As described therein, the hemolysis-inhibiting effects of this C 5 blocker were assayed over a 90 minute period of circulation. The results of these assays are charted in FIG. 10 b, and show that the C 5 blocker essentially completely inhibited the cell lysing ability of the human blood during the entire 90 minute period of circulation.
[0136] The results of these experiments demonstrate that these C 5 blockers will survive in the bloodstream for a substantial period of timer thus making periodic administration practical.
EXAMPLE 8
Preparation of a C 5 Blocker
[0137] A C 5 blocker mAb suitable for use in the practice of the present invention was prepared as follows.
[0138] Balb/c mice were immunized three times by intraperitoneal injection with human C 5 protein (Quidel Corporation, San Diego, Calif., Catalog #A403). The first injection contained 100 μg of C 5 protein in a complete Freund's adjuvant emulsion, the second immunization contained 100 μg of C 5 protein in an incomplete Freund's adjuvant emulsion, and the third immunization was 100 μg of protein in PBS. The mice were injected at roughly 2 month intervals.
[0139] Fusions of splenocytes to myeloma cells to generate hybridomas were performed essentially as described in Current Protocols in. Immunology (John Wiley & Sons, New York, 1992, pages 2.5.1 to 2.5.17). One day prior to fusion the mice were boosted IV with 100 μg of C 5 protein. On the day of fusion, the immunized mice were sacrificed and spleens was harvested. SP2/0-AG14 myeloma cells (ATCC CRL#1581) were used as the fusion partner SP2/0-AG14 cultures were split on the day before the fusion to induce active cell division. A ratio of 1:10 (myeloma cells:splenocytes) was used in the fusions.
[0140] The cells were fused using PEG 1450 in PBS without calcium (Sigma Chemical Company, St. Louis, Mo., Catalog No. P-7181) and plated at 1-2.5×10 5 cells per well. Selection in EX-CELL 300 medium (JRH Biosciences, Lexena, Kans., Catalog No. 14337-78P) supplemented with 10% heat inactivated fetal bovine serum (FBS); glutamine, penicillin and streptomycin (CPS); and HAT (Sigma Chemical Company, St. Louis, Mo., Catalog No. H-0262) was started the following day. The fusions were then fed every other day with fresh FBS, GPS, and HAT supplemented medium. Cell death could be seen as early as 2 days and viable cell clusters could be seen as early as 5 days after initiating selection. After two weeks of selection in HAT, surviving hybridomas chosen for further study were transferred to EX-CELL 300 medium supplemented with FBS, GPS, and MT (Sigma Chemical Company, St. Louis, Mo., Catalog No. H-0137) for 1 week and then cultured in EX-CELL 300 medium supplemented with PBS and GPS.
[0141] Hybridomas were screened for reactivity to C 5 and inhibition of complement-mediated hemolysis 10-14 days after fusion, and were carried at least until the screening results were analyzed. The screen for inhibition of hemolysis was the chicken erythrocyte lysis assay described above. The screen for C 5 reactivity was an ELISA, which was carried out using the following protocol.
[0142] A 50 μL aliquot of a 2 μg/ml solution of C 5 (Quidel Corporation, San Diego, Calif.) in sodium carbonate/bicarbonate buffer, pH 9.5, was incubated overnight at 4° C. in each test well of a 96 well plate (Nunc-Immuno F96 Polysorp, A/S Nunc, Roskilde, Denmark). The wells were then subjected to a wash step. (Each wash step Consisted of three washes with TBST.) Next, test wells were blocked with 200 μL of blocking solution, 1% BSA in TBS (BSA/TBS) for 1 hour at 37° C. After an additional wash step, a 50 μL aliquot of hybridoma supernatant was incubated in each test well for 1 hour at 37° C. with a subsequent wash step. As a secondary (detection) antibody, 50 μL of a 1:2000 dilution of horseradish peroxidase (HRP) conjugated goat anti-mouse IgG in BSA/TBS, was incubated in each test well for 1 hour at 37° C., followed by a wash step. Following the manufacturer's procedures, 10 mg of O-phenylenediamine (Sigma Chemical Company, St. Louis, Mo., Catalog No. P-8287) was dissolved in 25 mLs of phosphate-citrate buffer (Sigma Chemical Company, St. Louis, Mo., Catalog No. P-4922), and 50 μL of this substrate solution was added to each well to allow detection of peroxidase activity. Finally, to stop the peroxidase detection reaction, a 50 μL aliquot of 3 N hydrochloric acid was added to each well. The presence of antibodies reactive with C 5 in the hybridoma supernatants was read out by a spectrophotometric OD determination at 490 nm.
[0143] The supernatant front a hybridoma designated as 5 G 1 . 1 tested positive by ELISA and substantially reduced the cell-lysing ability of complement present in normal human blood in the chicken erythrocyte hemolysis assay. Further analyses revealed that the 5 G 1 . 1 antibody reduces the cell-lysing ability of component present in normal human blood so efficiently that, even when present at roughly one-half the molar concentration of human C 5 in the hemolytic assay, it can almost completely neutralize serum hemolytic activity.
[0144] Hybridoma 5 G 1 . 1 was deposited with the American Type Culture Collection, 10801 University Boulevard, Manassas, Va. 20110-2209, United States of America, on Apr. 27, 1994, and has been assigned the designation HB-11625. This deposit were made under the Budapest Treaty on the International Recognition of the Deposit of Micro-organisms for the Purposes of Patent Procedure (1977).
[0145] Throughout this application various publications and patent disclosures are referred to. The teachings and disclosures thereof, in their entireties, are hereby incorporated by reference into this application to more fully describe the state of the art to which the present invention pertains.
[0146] Although preferred and other embodiments of the invention have been described herein, further embodiments may be perceived by those skilled in the art without departing from the scope of the invention as defined by the following claims.
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TABLE 1 NUMBER OF LIMBS AFFECTED PER GROUP* % Hemolytic Treatment n Day 0 Day 10 % Change Activity Control 4 4 (1.0) 9 (2.3) +125.0 95.6 + 3.8 C5 6 8 (1.3) 7 (1.2) −12.5 13.9 + 4.7 Blocker
[0270] [0270] TABLE 2 NUMBER OF LIMBS AFFECTED PER MOUSE Mouse % % Hemolytic (treatment) Day 0 Day 10 Change Activity #8 (control) 1 (RL) 2 (RL & RR) +100 91.2 #2 (C5 blocker) 1 (FL) 1 (FL)* 0 22.4 #6 (control) 1 (RR) 2 (RR & RL) +100 103.2 #5 (C5 blocker) 1 (RR) 1 (RR) 0 6.0 #1 (control) 1 (FL) 2 (FL & FR) +100 92.4 #4 (C5 blocker) 1 (RL) 2 (FL & RL) 100 9.2 #9 (control) † 1 (RL) 2 (RR & RL) +100 not tested #3 (C5 blocker) † 2 (FL & RR) 1 (FL) −100 0.4 #7 (C5 blocker) § 1 (FR) 1 (FR) 0 13.6 #10 (C5 b1ocker) § 2 (RL & RR) 1 (RR)** −100 32.0 | The use of compounds that block complement component or its active fragments C 5 a and/or C 5 b (such compounds collectively referred to as “C 5 blockers”) to treat established joint inflammation (arthritis) is disclosed. Administration of such C 5 blockers has been found to: 1) arrest and/or reduce inflammation in joints which are already inflamed, and 2) inhibit the spread of inflammation to unaffected joints. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority from U.S. Provisional Patent Application Ser. No. 61/062,380, filed Jan. 25, 2008.
FIELD OF THE INVENTION
This invention relates to compound bows, and more specifically, it relates to a two-track system for bow strings and power cables of the compound bow.
BACKGROUND OF THE INVENTION
Cams have been used on compound bows for some time. Compound bows have opposing limbs extending from a handle portion which house the cam assemblies. Typically, the cam assemblies are rotatably mounted on an axel which is then mounted on a limbs of bow. The compound bows have a bow string attached to the cam which sits in a track and also, generally, two power cables that each sit in a track on a separate component on the cam, and either anchored to the cam or a limb/axel. When a bowstring is pulled to full draw position, the cam is rotated and the power cables are “taken up” on their respective ends to increase energy stored in the bow for later transfer, with the opposing ends “let out” to provide some give in the power cable.
Cam assemblies are designed to yield efficient energy transfer from the bow to the arrow. Some assemblies seek to achieve a decrease in draw force closer to full draw and increase energy stored by the bow at full draw for a given amount of rotation of the cam assembly.
There exists a number of U.S. patents directed to compound bows, including U.S. Pat. No. 7,305,979 issued to Craig Yehle on Dec. 11, 2007. The Yehle patent discloses a cam assembly having a journal for letting out a draw cable causing the cam to rotate and two other journals for take-up mechanism and a let-out mechanism for the two power cables. The Yehle patent requires that the power cables and draw string each sit in a different components and tracks for the take up and let out mechanism to work and to have the efficiencies described therein.
Therefore, a compound bow having a mechanism with fewer tracks is desired because of the advantage in assembly in manufacturing and to increase efficiency in the transfer of energy to propel bows.
Further, an adjustable or modular take-up/let-out mechanism is desired to account for different size draw lengths or other specifications required by the user.
SUMMARY OF THE INVENTION
The invention comprises, in one form thereof, a cam assembly comprising bowstring cam component having a track for receiving a bowstring; and a power cable cam component having a take up portion and a let out portion, wherein the take up and let out portion have a track for receiving a power cable.
More particularly, the invention includes a compound bow comprising a handle portion; a limb portion; at least two cam assemblies, each comprising a bowstring cam component having a track for receiving a bowstring; and a power cable cam component having a take up portion and a let out portion, wherein the take up and let out portion have a track for receiving a power cable, a draw stop pin, a take up terminating post, and a let out terminating post; an axel; at least two power cables; and a bowstring.
The cam assembly has a two track system wherein the power cables utilize a track or opposing tracks made on the power cable component of the cam assembly. Another track is formed on the bowstring component of the cam assembly in which the bowstring lies.
An advantage of the present invention is that the device has high efficiency in transfering energy stored in the limbs during the draw cycle to the arrow or other projectile of the device.
A further advantage of the present invention is that it requires less component parts for cam assembly which is highly desireable in the art.
An even further advantage of the present invention is that the cam assembly allows for a modular format which allows the user to change minor components to change parameters of the device (e.g. draw length) without having to change the entire cam assembly or bow.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is disclosed with reference to the accompanying drawings, wherein:
FIG. 1 is a side view of a dual cam compound bow embodying the present invention;
FIG. 2 is a side view of the top cam assembly in a first embodiment of the present invention.
FIG. 3 is a rearview of the top cam assembly in a first embodiment of the present invention.
FIG. 4 is a side view of the bottom cam assembly in a first embodiment of the present invention.
FIG. 5 is a rearview of the bottom cam assembly in a first embodiment of the present invention.
FIG. 6 and 7 show the modular form of the let out portion 64 a,b with the draw stop pin 90 a,b attached thereto.
FIG. 8 is a side view of the top cam assembly in a second embodiment of the present invention.
FIG. 9 is a side view of the bottom cam assembly in a second embodiment of the present invention.
FIG. 10 is a side view of the top cam assembly in a third embodiment of the present invention.
FIG. 11 is a side view of the bottom cam assembly in a third embodiment of the present invention.
FIG. 12 is a rearview of the top cam assembly in a fourth embodiment of the present invention.
FIG. 13 is a rearview of the bottom cam assembly in a first embodiment of the present invention.
Corresponding reference characters indicate corresponding parts throughout the several views. The examples set out herein illustrate a few embodiments of the invention but should not be construed as limiting the scope of the invention in any manner.
DETAILED DESCRIPTION
FIG. 1 shows a dual cam compound bow 10 of the present invention. The bow 10 has a frame, which includes bow limbs 12 a,b extending from handle 14 . Extending from the handle is cable guard 16 and a cable slide 18 through which the power cables 50 and 52 are placed. The bowstring 70 and power cables 50 , 52 are attached to the bow 10 at the cam assemblies 30 a,b , which further is placed on the limbs via axel 36 a,b . The cams 30 a,b are shown in greater detail in the following figures.
The cams 30 a,b have bowstring assemblies 40 a,b , each having a single track for the bowstring 70 with each end of the bowstring 70 being attached to the cams 30 a,b at a terminating post (not shown). Further, the each of the cams 30 a,b have terminating posts 80 , 82 for each of the ends of the respective power cables 50 , 52 , and which will be described in more detail herein. Further, each cam assembly 30 a,b has a power cable assembly 60 a,b having either a single track or groove around perimeter of the assembly 60 a,b for receiving or retaining the power cables. Alternatively, the power cable assembly 60 a,b can have the tracks or grooves on the portions of the assembly receiving the cable instead of a unitary track around the perimeter. The power cable assembly 60 a,b has a take up portion 62 a,b and a let out portion 64 a,b for managing the take up and let out of the power cables through a single track.
FIG. 2 shows a side view of the top cam assembly 30 a . FIG. 2 shows one embodiment of the cam 30 a in non-circular shape. The bowstring 70 is in line with the track in the bowstring assembly 40 a and attached with a terminating post (not shown). The power cable assembly 60 a has a take up portion 62 a and a let out portion 64 a , and can either be a unitary piece or be modular. For instance as shown in FIG. 2 , the power cable assembly 60 a has a modular unit for the let out portion 64 a , which allows manufacturers to make a single cam assembly with one small piece that can account for varying sizes and preferences by the user. Specifically, this versatility is important because each hunter or archer has different specifications (e.g. draw length) which can be accounted for by having a modular portion to the cam assembly 30 a , and in this case is the let out portion 64 a . The power cable 52 , in FIG. 2 , is attached to terminating post 82 a and wraps around the let out portion 64 a and therefore feeds power cable 52 out when the bow is in full draw. On the opposing side of power cable assembly 60 a is power cable 50 , which sits on the take up portion 62 a of the assembly 60 a . Power cable 50 is attached at terminating post 80 a , and is taken up when the bow is in full draw by the take up portion 62 a . The power cable assembly 60 a is attached to the bowstring assembly 30 a by a fastening mechanism, but it will be well recognized the power cable assembly 60 a can be attached to the bowstring assembly 40 a by any means or, if desired, manufactured as a single piece with the bowstring assembly 40 a to make-up top cam assembly 30 a . As shown, the power cable assembly 60 a is attached to the bowstring assembly 40 a by a fastener 78 a . The cam assembly 30 a is attached to the limb 12 a by axel 36 a . Last the take power cable assembly 60 a , either in a unitary form or modular form, may optionally have draw stop pin 90 a attached to stop the draw cycle of the bow. The draw stop pin 90 a , however, does not have to be attached to the power cable assembly 60 a in order to function on the cam assembly 30 a.
FIG. 3 shows the rearview of the top cam assembly. As seen from this perspective, the cam assembly 30 a has one track on the bowstring assembly 40 a for the bowstring 70 and a second track for the power cables 52 and 50 (not shown) on same track but on opposing sides of the power cable assembly 60 a . In FIG. 3 , the let out portion 64 a is visible with power cable 52 sitting in the track or groove. Axel 36 a is inserted through the limb 12 a and then the cam assembly 30 a and then the other end of the limb 12 a.
FIG. 4 shows a side view of the bottom cam assembly 30 b . FIG. 4 shows the bottom cam 30 b in non-circular shape as well. The bowstring 70 is in bowstring assembly 40 b and attached with a terminating post (not shown). The power cable assembly 60 b has a take up portion 62 b and a let out portion 64 b , which can either be a unitary piece or as shown can have a modular unit. In FIG. 4 , there is a modular assembly shown where the let up portion 64 b can be changed in size and shape according to the user's specifications. The power cable 52 , in FIG. 4 , is attached to terminating post 80 b and wraps around the take up portion 62 b and therefore is taken up when the bow is in full draw. On the opposing side of power cable assembly 60 b is power cable 50 , which attaches to terminating post 82 b and wraps around the let out portion 64 b , and is let out when the bow is in full draw position. The power cam assembly 60 b is attached to the bowstring assembly 30 b by a fastening mechanism, the two assemblies can be attached by any means or if desired manufactured as a single piece. As shown, the power cable assembly 60 b is attached to the bowstring assembly 40 b by a fastener 78 b . The cam assembly 30 b is attached to the limb 12 b by axel 36 b . Last the power cable assembly 60 b , either in a unitary or modular form, may optionally have draw stop pin 90 b attached to stop the draw cycle of the bow.
FIG. 5 shows the rearview of the bottom cam assembly 30 b . As seen from this perspective, the cam assembly 30 b has a bowstring assembly 40 b for the bowstring 70 , and a power cable assembly 60 b for both power cables 50 , 52 . In FIG. 5 , power cable 50 is visible because it is sitting on the let out portion 64 b of the power cable assembly 60 b . Axel 36 b allows bottom cam assembly 30 b to rotate when the drawstring is pulled, and holds bottom cam assembly 30 b in limb 12 b.
FIG. 6 and 7 show the modular form of the let out portion 64 a,b and draw stop pin 90 a,b for the cam assemblies 30 a,b . The let out portion 64 a,b and draw stop pins 90 a,b can be attached in any number of ways or can be further manufactured as a unitary piece. Further, as described above, let out portion 64 a,b can be manufactured as a single part of power cable assembly 60 a,b . Therefore, though the modular form is more desirable to personalize the parameters of the device size (e.g. draw length), the cam assembly could be manufactured as a single unit or in varying degrees of pieces.
FIG. 8 and 9 show a side view of a second embodiment of the present invention 100 a,b . FIG. 8 shows the top cam assembly 100 a is in a circular shape. In particular, the power cable assembly 120 a is shown as being in a unitary form, having the take up portion 122 a and let out portion 124 a . The draw stop pin 90 a is not attached to the power cable assembly 120 a , though if preferred the assembly 120 a could be attached to the pin 90 a . Further the bowstring assembly 110 a is also in a circular or disc shape with power cable assembly 120 a attached thereto. FIG. 9 exemplifies the bottom cam assembly 100 b for the second embodiment, which is in a circular or disc shape. Generally the other components of the cam assemblies 100 a,b are similar to those shown in the first embodiment.
FIGS. 10 and 11 show a third embodiment of the present invention, wherein the cam assembly 200 a,b have a circular portion for the bowstring track 110 a,b and a non-circular power cable assembly 60 a,b . It will be understood that other embodiments could include a non-circular portion for the bowstring assembly and a circular power cable assembly and, again, can be either modular or unitary form. Further other geometrical shapes, such as ovular, may be used in varying forms for either the bowstring or power cable assembly.
Still another embodiment could include a three track system, as shown in the rearview perspectives of FIG. 12 and 13 . The three track system would be used where there are four power cables. This type of embodiment would include two power cable assemblies as described above, both of which would be attached to the bowstring assembly.
In use, using the first embodiments as an exemplar and in reference to FIGS. 1-3 , the bowstring 70 is pulled rearward toward the hunter or archer. The tension by the bowstring forces the cam assemblies 30 a,b to rotate rearward. Focusing on FIG. 1 , the power cable assembly 60 a on top cam assembly 30 a is moved upward as the entire cam 30 a is moved rearward. The terminating post 80 , with power cable 50 attached, moves upward, and therefore causes take up of power cable 50 . On the bottom cam assembly 30 b the cam 30 b is also moved rearwardly. The positioning of the power cable assembly 60 and power cable 50 causes power cable 50 to be let out on the bottom cam assembly 30 a . The same is true in the opposite manner for power cable 52 (i.e. power cable 52 is taken up) on the cam assemblies 30 a,b . Accordingly energy is stored in the limbs of the device and transferred to the arrow or other projectile placed in the compound bow in a highly efficient manner with little shock to the user.
Though the compound bow embodying the invention may have differing specifications, the bow may have a brace height of about eight (8) inches and axel-to-axel length of about thirty-two and half (32½) inches. The draw length can range from twenty-seven (27) to thirty (30) inches and a draw weight between sixty (60) to eighty (80) inches.
It should be particularly noted that dual track cam disclosed in this invention has a highly efficient and powerful performance. With respect to speed, the following performance results were noted in a twenty-nine (29″) inch draw cycle, sixty pound (60 lbs.) draw weight compound bow, in testing completed by Archery Evolution:
Arrow (Grains)
300
360
420
540
Speed (ft./sec.)
307.3
283.5
264.2
235.4
Kinetic Energy (ft.lbs.)
62.9
64.2
65.1
66.4
Momentum
13.2
14.6
15.9
18.2
Dynamic Efficiency
83.7%
85.5%
86.7%
88.5%
Noise Output (dBA)
88.7
84.1
85.5
87.1
Total Vibration (G)
222.8
234.4
228.7
188.6
While the invention has been described with reference to particular embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope of the invention.
Therefore, it is intended that the invention not be limited to the particular embodiments disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope and spirit of the appended claims. | The present invention comprises a two-track cam assembly wherein the cam assembly has a bowstring component for housing the bowstring and a power cable component that allows for the take up and let out of the power cable on opposing ends of the power cable component, effectively creating a two-track cam assembly. The efficiency rating of the device achieves 95.8%. The cam assembly can come in a unitary or modular form and further each component (i.e. the bowstring or power cable component) can be in a circular or non-circular form. | 8 |
CROSS REFERENCES
[0001] This application is a continuation in part of U.S. patent application Ser. No. 09/377,094 filed on Aug. 19, 2001.
BACKGROUND OF THE INVENTION
[0002] This invention relates generally to the construction of retaining walls used in landscaping applications. Such walls are used to provide lateral support between differing ground levels where the change in one elevation to the other occurs over a relatively short distance, thereby reducing the possibility of erosion and landslides. Retaining walls can be both functional and decorative and range from small gardening applications to large-scale construction. They are constructed of a variety of materials and shapes. Some have been constructed of wood timbers, others of rock in a natural form (such as limestone). Still others have been constructed of manufactured aggregate or concrete blocks. The present invention relates to a manufactured block.
[0003] Constructing a fit and true retaining wall can be an arduous endeavor. In addition to laying a level first course on ground which is usually located at the foot or in the side of a steep embankment, the builder must ensure that each subsequent course is level. An error made in a lower course usually gets exaggerated as higher courses are stacked above it. As a wall made of blocks necessarily develops somewhat of a grid-like appearance, interruptions or undulations in the lines of the wall become readily apparent to the human eye.
[0004] One particular problem the prior art has failed to overcome is developing a retaining wall block shaped to avoid these undulations and interruptions which are caused by blocks being stacked on dirt or debris found on the upper surface of the lower course of blocks. Dirt presents itself as a result of the fill material used to fill the gap between the rear of the wall and the earth it is being built to retain. This fill material usually consists of small, coarse rocks. They serve as a barrier between the earth and the wall and prevent wet earth from seeping through the bricks of the wall during inclement weather. Present wall building methods include laying a course of blocks, filling the space behind the course with fill material, packing the fill material, and carefully sweeping the dirt off of each completed course prior to the addition of the next course. This final, sweeping step is time consuming but necessary to ensure the next course of blocks lies flat on the lower course.
[0005] Some larger blocks incorporate continuous cavities that extend from their bottom surface to their top surfaces. These cavities are intended to reduce the amount of material required to form the block, thereby reducing its cost and weight, and also allow an area to be filled with fill material once a course is finished. At first blush it would appear that, because the presence of cavities reduces the surface area of the top and bottom of the block, they would also serve to decrease the area for interference by small stones and debris between courses. However, because the cavities are filled with fill material, the fill material spills over the upper surfaces and exacerbates, rather than alleviates, the problem. Furthermore, smaller blocks cannot incorporate cavity portions without jeopardizing their structural integrity.
[0006] The inability of smaller blocks to accommodate cavity portions creates further problems. Making a solid block out of concrete results in a dense rock which is heavy for its relatively small size. Working with these rocks can become cumbersome. The absence of cavities or interruption in the side walls makes these blocks difficult to lift. They have few areas which lend themselves to easy gripping and lifting. This becomes an important consideration in light of the number of blocks that must be lifted and set in place during the construction of even a relatively small retaining wall.
[0007] It would be desirable to develop a retaining wall block shaped to accept a certain amount of dirt and debris from course to course without adversely affecting the overall structure and aesthetics of the resulting wall. It would also be desirable to devise a small retaining wall block which has a reduced unit weight due to the absence of block material in an area that will not adversely affect the strength of the block or its appearance. Finally, it would be desirable to provide a small retaining wall block which is relatively easy to grasp and pick up off of a stack of similar blocks.
[0008] These and other objectives and advantages of the invention will appear more fully from the following description, made in conjunction with the accompanying drawings wherein like reference characters refer to the same or similar parts throughout the several views.
SUMMARY OF THE INVENTION
[0009] The present invention advantageously provides a block for use in building a retaining wall that produces a level course of blocks, despite the presence of a small amount of debris on the lower course of blocks.
[0010] The present invention is also advantageous in that it provides a relatively small block with material removed from strategic locations to provide a block which is lighter than it would have been had it been solid, yet the removal of material has not adversely affected the strength of the block, nor the appearance of the resulting wall.
[0011] The present invention advantageously provides a block which has areas for a person building a retaining wall to grasp the block when lifting the block off of a stack of such blocks and placing the block on a lower course of blocks in the wall being constructed.
[0012] The instant invention relates to a retaining wall block so shaped that when placed on top of a lower course of similar blocks, it lies flat despite the inevitable presence of dirt, small stones, and other debris. This feature alleviates the time-consuming step of meticulously cleaning the top of each course of blocks before the next course may be laid on top of it.
[0013] The block generally comprises a continuous top surface, front and back surfaces extending from the top surface, multi-faceted side surfaces extending from the top surface and spanning from the front surface to perpendicularly intersect the back surface, and a bottom surface having a predetermined surface area that is integral with the front and side surfaces. A gutter is formed into the bottom surface of the block and is spaced away from the rear surface of the block. The gutter formed into the bottom surface of the block preferably has a forward edge that has a minimal surface area that acts to support a rear portion of the block upon a lower course of blocks.
[0014] In order to further lighten a block constructed according the present invention, the multifaceted side surfaces of the blocks include an inwardly inset sidewall portion that perpendicularly intersects the rear surface of the block. The multifaceted side surfaces of the block may further comprise a shoulder formed between the aforementioned sidewalls and a forward portion of the multifaceted side surfaces wherein the shoulder and the forward portion of the multifaceted side wall intersect at an obtuse angle.
[0015] In order to achieve the tolerance of small stones and debris between courses, a portion of the bottom face of the block of the present invention is non-planar, and more preferably, concave. This concave surface significantly reduces the area for block to block contact between successive courses. Preferably, this non-planar portion covers more than one half of the area of the bottom surface of the block. It also functions to provide an area of clearance or a gap between the stones where debris can migrate without causing interference or instability between courses. The concave portion is preferably shaped to form a portion of a cylinder and extends from one side surface to the other. Alternatively, the concave portion could be shaped to form a portion of a sphere or any other shape.
[0016] In addition to the concave portion of the bottom surface, the present invention further comprises a plurality of grooves formed in the bottom surface and preferably extending transversely of the bottom surface between the front and back surfaces. The grooves preferably are angled inwardly to form an inverted “V” shape when the block is given its intended orientation. The grooves allow spaces of increased clearance for larger stones. The grooves preferably comprise two opposed surfaces of a predetermined width extending the length of the groove. The two surfaces are angled to form a “V” shape and meet to form an angle α. The angled walls of the grooves not only reduce the weight of the block and act as a splitting aid, but also act to funnel larger stones into the grooves, thereby positioning them into an area of maximum clearance.
[0017] Alternatively, the first and second surfaces may be joined by a third, curved or flat, surface juxtaposed between the first and second surfaces. Such a third surface would give the groove an inverted “U” shape. The grooves are cut into the block and have a set depth which follows the irregular contour of the non-planar bottom surface.
[0018] Preferably, the bottom surface further comprises one or more downward projections proximate the rear surface and having an abutting surface which contacts the rear surface of a lower course of blocks when the block is stacked thereon. It is envisioned that the abutting surface is either parallel to the rear surface of the block, or forms an angle β, with the rear surface. These projections create an automatic and uniform setback among successive courses of blocks so that the resulting retaining wall is angled rearwardly. This also adds resistive strength to the wall against the natural forces exerted on the wall by the earth the wall is retaining by tying successive courses of blocks into those course below them. Preferably, the downward projection has a generally trapezoidal cross-sectional shape and is spaced away from the rear surface of the block. In addition, the abutting surface of the downward projection is preferably integral with a rear face of the gutter.
DESCRIPTION OF THE DRAWINGS
[0019] [0019]FIG. 1 is a perspective view of a block of the present invention, looking up at the bottom to reveal the details of the bottom surface;
[0020] [0020]FIG. 2 is a cross sectional view of the block of the present invention taken along lines 2 - 2 of FIG. 1;
[0021] [0021]FIG. 3 is a cross sectional view of the block of the present invention taken along lines 3 - 3 of FIG. 1 and shown with other blocks in phantom, stacked, as in a retaining wall;
[0022] [0022]FIG. 4 is a bottom plan view of the block of FIG. 1;
[0023] [0023]FIG. 5 is a perspective view of the block shown in FIG. 1 in a stacked relationship with other blocks, as in a wall, and showing debris resting on a lower course of blocks and accommodated for by the concave area of the bottom surface of the block of the present invention;
[0024] [0024]FIG. 6 is a perspective view of an alternative embodiment of the present invention, looking up at the bottom to show the detail of the bottom surface;
[0025] [0025]FIG. 7 is a sectional elevational view taken along lines 7 - 7 of FIG. 6;
[0026] [0026]FIG. 8 is an end elevational view of a block of the embodiment shown in FIG. 6, in stacked relation, as in a wall, with other blocks shown in phantom;
[0027] [0027]FIG. 9 is a bottom plan view of a block of the embodiment shown in FIG. 6;
[0028] [0028]FIG. 10 is a bottom plan view of a block of the present invention;
[0029] [0029]FIG. 11 is a cross-sectional view of the block of FIG. 10 taken along cutting lines 11 - 11 in FIG. 10;
[0030] [0030]FIG. 12 is a cross-sectional view of the block of FIG. 10 taken along cutting lines 12 - 12 in FIG. 10;
[0031] [0031]FIG. 13 is a top plan view of the block of FIG. 10;
[0032] [0032]FIG. 14 is a front elevational view of the block of FIG. 10;
[0033] [0033]FIG. 15 is a side elevational view of a first side of the block of FIG. 10; and,
[0034] [0034]FIG. 16 is a side elevation view of a second side of the block of FIG. 10.
DETAILED DESCRIPTION
[0035] Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined only by the claims.
[0036] Referring now to FIG. 1, there is shown a retaining wall block 10 having a front surface 12 , side surfaces 14 a and 14 b extending rearwardly from front surface 12 and integral with rear surface 16 . Top surface 18 is generally planar and continuous across its extents. Top surface 18 extends from side surface 14 a to side surface 14 b, and from front surface 12 to rear surface 16 . Preferably, top surface 18 is generally perpendicular to side surfaces 14 a and 14 b, and also to front surface 12 and rear surface 16 .
[0037] In the embodiment shown in FIGS. 1 - 9 , front surface 12 comprises three parts, 12 a, 12 b, and 12 c. Part 12 c is generally parallel to rear surface 16 and lies between parts 12 a and 12 b . Parts 12 a and 12 b are angled such that the extend from part 12 c and diverge rearwardly to meet side surfaces 14 a and 14 b , respectively. Parts 12 a , 12 b , and 12 c are shown as split faces as opposed to formed faces. Creating a face with a rock splitter results in an irregular, more natural appearing surface. Also shown in the Figures is a rear surface 16 which has a smaller width than front surface 12 such that side surface 14 a and 14 b must converge rearwardly in order to be integral with rear surface 16 . This shape allows the construction of straight, concave, convex, or serpentine walls without interrupting the relatively uniform appearance created by the front surfaces 12 of a plurality of blocks 10 forming a wall.
[0038] Bottom surface 20 extends from front surface 12 to rear surface 16 and from side surface 14 a to side surface 14 b . Bottom surface 20 includes concave, or non-planar portion 22 . Concave portion 22 is depicted in FIGS. 1, 3 and 4 as a relatively cylindrical indentation in bottom surface 20 , extending from side surface 14 a to side surface 14 b . Preferably, portion 22 does not extend forward of where side surfaces 14 a and 14 b meet parts 12 a and 12 b of front surface 12 . This way concave portion 22 is not visible in a completed wall, regardless of whether the wall is straight, concave, convex, or serpentine.
[0039] Allowing concave portion 22 to extend from side surface 14 a to side surface 14 b creates a gap 24 between the bottom surface 20 and the upper surface of a lower course of blocks when block 10 is placed thereon. This gap 24 may be used for ease in picking the block up and setting the block down. Also, as shown in FIGS. 1, 3 and 4 , concave portion 22 extends rearwardly but ends forward of downward projection 34 , which is described in more detail below. Ending the concave or, non-planar portion 22 forward of downward projection 34 provides another flat surface for block to block contact to assist in the leveling and stabilization of block 10 on a lower course of blocks.
[0040] Alternatively, it is envisioned that concave portion 22 be an indentation of any shape, such as the generally spherical shape of the embodiment shown in FIGS. 6 - 9 . Preferably, portion 22 is large enough to occupy at least 30 percent, more preferably on the order of 50 to 75 percent, of the surface area of bottom surface 20 .
[0041] In one embodiment, bottom surface 20 also includes at least one, preferably a plurality of, grooves 28 . As shown in FIG. 2, grooves 28 are preferably “V”-shaped and extend from the bottom surface into the block toward top surface 18 . In the embodiment depicted in FIGS. 1 and 2, grooves 28 are spaced generally equidistant from each other and oriented such that they extend from front to back generally across the non-planar portion 22 . It is envisioned that grooves 28 could be located generally anywhere across bottom surface 20 . It is preferred, however, that grooves 28 do not intersect front surface 12 so that grooves 28 remain hidden from view when block 10 is part of a completed wall.
[0042] Grooves 28 having the preferred “V” shape generally comprise at least a first surface 30 and a second surface 32 . First surface 30 extends from bottom surface 20 and is integral with second surface 32 . Second surface 32 extends from first surface 30 to bottom surface 20 thereby forming an angle a between first surface 30 and second surface 32 as seen in FIGS. 2 and 7. Angle α is preferably less than 180 degrees. Alternatively, first surface 30 and second surface 32 could be joined by a third surface (not shown in the Figures) which extends along the length of the groove and is juxtapose between the first and second surfaces. This third surface could be curved, thereby forming a “U” shaped groove, or the third surface could be flat, thereby forming a rectangular groove. However, a “V” shaped groove generally eases manufacturing.
[0043] As shown in all Figures, bottom surface 20 also includes at least one downward projection 34 . Downward projection 34 may extend across bottom surface 20 , adjacent rear surface 16 as shown in FIGS. 1, 2, and 4 . Alternatively, projection 34 may be broken into more than one projection 34 as shown in FIGS. 6, 7 and 9 . Projection 34 has an abutting surface 36 which is used to abut against the rear surface 16 of a lower course of blocks, thereby forming a setback between successive courses of blocks. This setback add strength and stability to the resulting wall.
[0044] Abutting surface 36 may be substantially parallel to rear surface 16 . Alternatively, for ease of manufacture, abutting surface 36 may angle rearwardly forming a relatively small angle β with rear surface 16 as shown in FIG. 3. Angle β is preferably less than 45 degrees, more preferably less than 30 degrees. A smaller angle β provides more resistance to horizontal block slippage due to external forces against the back of the resulting wall.
[0045] Referring now to FIGS. 10 - 16 , there is shown a preferred embodiment of a retaining wall block 50 having a front surface 52 , side surfaces 54 a and 54 b extending rearwardly from front surface 52 toward rear surface 56 . Top surface 58 is generally planar and continuous across its extents. Top surface 58 extends from side surface 54 a to side surface 54 b , and from front surface 52 to rear surface 56 . Preferably, top surface 58 is generally perpendicular to side surfaces 54 a and 54 b , and also to front surface 52 and rear surface 56 .
[0046] In the embodiment shown in FIGS. 10 - 16 , front surface 52 comprises three parts, 52 a , 52 b , and 52 c. In general, these parts will referred to as the front surface parts or as the face of the block 50 . Part 52 c is generally parallel to rear surface 56 and lies between parts 52 a and 52 b. Parts 52 a and 52 b are angled such that they extend from part 52 c and diverge rearwardly to meet side surfaces 54 a and 54 b , respectively.
[0047] Parts 52 a , 52 b , and 52 c are in FIGS. 10 - 16 shown as formed or smooth faces as opposed to split faces. Block 50 may preferably be formed by splitting as described above in conjunction with FIGS. 1 - 9 . Creating a face with a rock splitter results in an irregular, more natural appearing surface. As can be seen in the Figures, rear surface 56 has a smaller width than front surface 52 . Side surfaces 54 a and 54 b converge rearwardly toward the rear surface 56 at obtuse angle to the rear surface 56 . This shape allows the construction of straight, concave, convex, or serpentine walls without interrupting the relatively uniform appearance created by the front surfaces 52 of a plurality of blocks 10 forming a wall.
[0048] Block 50 has a heel portion 70 that comprises the rear surface 56 , a projection 72 and a gutter 74 . As can be seen most clearly in FIGS. 10 and 13, sides 54 a and 54 b incorporate shoulders 76 a and 76 b , respectively. Shoulders 76 may also be seen as a forward boundary of the heel portion 70 of the block 50 . Note that shoulders 76 form an obtuse angle with respect to sides 54 . Heel portion side walls 78 a and 78 b extend rearwardly from respective shoulders 76 a and 76 b and intersect with rear surface 56 of block 50 . Heel portion side walls 78 a and 78 b are preferably formed perpendicular to shoulders 76 a and 76 b and to rear surface 56 of block 50 . The resulting sides 54 comprise multiple facets and provide a number of benefits. Formation of side walls 78 a and 78 b as illustrated in the Figures results in a lighter block 50 as the block 50 will have a smaller volume. As a corollary benefit, less concrete material is used in the formation of block 50 where side walls 78 a and 78 b are formed as indicated.
[0049] Bottom surface 60 extends from front surface 52 to gutter 74 and from side surface 54 a to side surface 54 b . Bottom surface 60 includes concave, or non-planar portion 62 . Concave portion 62 is depicted in FIGS. 11, 12, 15 , and 16 as a relatively cylindrical indentation in bottom surface 60 , extending from side surface 54 a to side surface 54 b . Preferably, portion 62 does not extend forward of where side surfaces 54 a and 54 b meet parts 52 a and 52 b of front surface 52 . In this way concave portion 62 will not be visible in a completed wall, regardless of whether the wall is straight, concave, convex, or serpentine.
[0050] Allowing concave portion 62 to extend from side surface 54 a to side surface 54 b creates a gap 64 between the bottom surface 60 and the upper surface of a lower course of blocks when block 50 is placed thereon. This gap 64 may be used for ease in picking the block 50 up and setting the block down. As can be seen in FIGS. 11, 12, 15 , and 16 , gap 64 extends all the way to the edge 75 of gutter 74 . Because gap 64 extends all the way to edge 75 of gutter 74 , a block 50 in an upper course of blocks will rest upon a block 50 in a lower course of blocks upon that portion of bottom surface 60 that extends between the front face parts 52 a , 52 b , and 52 c and the forward edge 63 of the concave portion 62 and the edge 75 of gutter 74 . As can be appreciated, the rear of the block 50 is supported only on edge 75 and not on a planar surface, i.e. edge 75 , while having any number of curvilinear and/or rectilinear shapes, has a small surface area with respect to the remainder of bottom surface 60 . This affords the benefits of increased friction between two courses of blocks 50 and prevents the entrapment of sand, gravel, or bits of concrete between the upper surface 58 of a lower course of blocks and the bottom surface 60 of an upper course of blocks.
[0051] Gutter 74 extends upwardly from edge 75 into the body of block 50 toward the top surface 58 . Gutter 76 extends laterally between heel portion side walls 78 a and 78 b and has a generally “U” shaped cross-sectional area. Note that the exact cross-sectional shape of the gutter 76 may vary. However it is important to form the gutter 74 without sharp-edged concave surfaces. Therefore, the cross-sectional shape of the gutter 74 will be gently curved within the constraints of its position and size. Such a shape avoids the formation of unwanted stress concentration points that might facilitate the fracture of the block.
[0052] The rear face of the gutter 74 extends downwardly, away from the top surface of block 50 and beyond edge 75 to form an abutting surface 80 of projection 72 . Projection 72 and its abutting surface 80 function in the same manner as projection 34 and its abutting surface 36 , described above. That is, projection 72 acts to rearwardly offset each course of blocks 50 from the lower course upon which the upper course of blocks 50 rest. Projection 72 is preferably offset forwardly from the rear surface 56 . As can be seen in the Figures, rear face 82 of projection 72 is moved forward of the rear surface 56 of the block 50 . Additionally, it is preferred to cant the rear face 82 of projection 72 forwardly so that the projection has a generally trapezoidal cross-sectional shape with radiused edges. While this trapezoidal shape is not the only shape that may be used, it does afford additional durability to the projection 72 in that the lack of sharp edges prevents chipping and fracture of the projection 72 . The trapezoidal shape of the abutting surface 80 of the projection 72 aids in the rapid construction of walls by preventing the entrapment of sand, gravel, or pieces of concrete between the abutting surface 80 of the projection 72 of a block 50 in an upper course and the rear surface 56 a block 50 in a lower course.
[0053] The formation of a heel structure 70 such as that illustrated in FIGS. 10 - 16 has the additional benefit of strengthening the projection 72 by forcing more of the concrete from which the blocks 50 are formed into the area of the mold that forms the projection 72 . Projection 72 of block 50 therefore has fewer voids, is more dense and is consequently stronger.
[0054] In the preferred embodiment, bottom surface 60 also includes at least one, and preferably a plurality of, grooves 86 that are similar in shape and disposition to the grooves 28 described above in conjunction with FIGS. 1 and 2. Grooves 86 preferably have the “V”-shape as described above. While the grooves 86 may be located generally anywhere across the bottom surface 60 , it is preferred to locate the grooves substantially within the curved portion 62 of the bottom surface 60 . As seen in FIG. 10, grooves 68 may extend from front to back from a position on surface 60 somewhat forward of the point where front surfaces 52 a and 52 b interest side surfaces 54 a and 54 b , respectively, to a position just forward of edge 75 of gutter 74 . Care must be taken to space the grooves 86 away from edge 75 sufficiently to avoid weakening edge 75 . Grooves 86 not only result in a lighter block 50 , but also realize a cost savings in the use of less concrete to form the blocks 50 . Additionally, grooves 86 may aid installers in the field by providing a fracture line along with the block 50 may be broken to fill a gap in wall made from blocks 50 .
[0055] The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims. | A block for use in constructing a retaining wall having a bottom with a non-planar portion which creates a gap between the bottom surface and the top surface of a lower course of similar blocks when the block is placed thereon. This gap assists the block in resting on the lower course of blocks in a stable, level manner by providing a space where small amounts of rubble and dirt may exist without interfering with the stacking of the blocks. The non-planar, preferably concave, portion is also advantageous in that it reduces the unit weight of the block without significantly affecting the structural integrity of the block. Preferably, the block's bottom surface further comprises a plurality of grooves which further reduce the weight of the block and provide additional clearance in the gap for larger stones. It is envisioned that these grooves be “V” shaped, thereby having angled walls which act to funnel the larger stones into an area of adequate clearance when the block is being placed on a lower course of similar blocks. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to German patent application serial number 102004022740.3 filed May 7, 2004 and PCT/EP2005/004865, filed May 4, 2005.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to an airbag module for use in a motor vehicle.
[0004] 2. Description of the Related Art
[0005] Side curtain airbags and other side airbags are used to protect vehicle passengers in the event of a side impact or a vehicle rollover accident. Side curtain airbags are disposed on the roof pillar of the vehicle and when inflated cover at least one side window and, if necessary, the B-pillars of the vehicle. These airbags are particularly designed for providing protection for an occupant's head and upper torso. Another type side airbags may also be disposed in the vehicle seat and, when needed, inflate between the passenger's upper body and the side vehicle structure. These two airbag types have in common that they are built planar with two side walls connected by an edge region, in contrast to front airbags, which are generally pillow-shaped. In this type of airbag, a gas generator, which is elongated and extends into the airbag through an opening, usually provides the gas supply. To this end, the gas generator is disposed partially within and partially outside the airbag. The opening through which the gas generator extends is located in the edge region in which two side walls of the airbag are connected together.
[0006] The gas generator is usually elongated. The area of the airbag in which the opening is located is L-shaped. The gas generator extends parallel to the longitudinal direction of the airbag. Since the discharge ports of the usually cylindrical wall of the gas generator are generally disposed rotationally symmetric for safety reasons (thrust neutrality), there arises the problem that the gas-bag fabric in the vicinity of the opening is greatly stressed by discharged gases.
[0007] It is known to provide a mounting made of sheet metal, which on the one hand holds the gas generator on the vehicle structure and, on the other hand, extends into the opening of the gas bag and partially surrounds the area of the discharge ports and thus protects the adjacent fabric.
[0008] Besides a relative high cost of assembly, this sheet metal element extending into the airbag has the disadvantage that it can damage the fabric of the airbag during the frequently long periods of time in which the airbag has been installed in the vehicle and is subjected to various shocks and vibrations. In the worst case, this may lead to failure of the airbag.
[0009] Proceeding herefrom, it is the object of the invention to provide an improved airbag module to reduce the potential for damage to the airbag during deployment.
SUMMARY OF THE INVENTION
[0010] According to the invention, an airbag module includes a gas-conducting element made of plastic connected to the fabric of the airbag in the area of a gas generator opening. To this end, the gas-conducting element is provided with an arcuate cross-section including an opening. Legs of the arcuate section are particularly suitable for connection to the fabric of the airbag, for example, by sewing.
[0011] By using a gas conducting element made from an appropriate plastic, polyamide or polypropylene for example, damage to the airbag fabric is prevented, even during lengthy storage. Elasticity may be maintained by choosing a suitable wall thickness, between, for example, 0.4 mm and 0.8 mm. In another example, the wall thickness may be between 1.5 mm and 2.5 mm.
[0012] In another embodiment, a gas generator is particularly easy to assemble into the airbag by providing a locking projection.
[0013] Another advantage of the airbag module according to the invention is that it prevents incorrect orientation of the gas-conducting element during final assembly.
[0014] Further objects, features and advantages of this invention will become readily apparent to persons skilled in the art after a review of the following description, with reference to the drawings and claims that are appended to and form a part of this specification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a longitudinal section through a side curtain airbag;
[0016] FIG. 2 is the gas-conducting element depicted in FIG. 1 ;
[0017] FIG. 3 is an opening area of the side curtain airbag including a gas generator;
[0018] FIG. 4 is the gas generator of FIG. 3 shown inserted into the gas-conducting element of FIG. 2 ;
[0019] FIG. 4 a is an alternate embodiment of FIG. 4 ;
[0020] FIG. 5 is a longitudinal section along the plane A-A depicted in FIG. 4 ;
[0021] FIG. 6 a is another exemplary embodiment of the gas-conducting element in a perspective view; and
[0022] FIG. 6 b is a longitudinal section through the gas-conducting element depicted in FIG. 6 a along the plane E.
DETAILED DESCRIPTION
[0023] FIG. 1 depicts a longitudinal section through a side curtain airbag 10 . The side curtain airbag 10 is provided with two side walls (of which a side wall 12 is shown), which are connected together in an edge region 14 , for example, by sewing. An upper edge 14 a of the edge region 14 includes an opening 16 for inserting a gas generator 30 (see FIG. 3 ) and tabs 18 for attaching the side curtain airbag 10 to a roof of a motor vehicle (not shown). The side curtain airbag 10 has intermediate seams 22 for contouring the airbag 10 and tethers 20 for positioning of the inflated airbag 10 in front of a side window of the motor vehicle.
[0024] An opening area 24 is L-shaped to permit the use of an elongated gas generator. The opening area 24 is approximately in the center of the top edge 14 a and includes the opening 16 into the airbag 10 . The gas generator 30 extends partially into the opening 16 and is arranged parallel to the longitudinal direction of the airbag 10 .
[0025] A gas-conducting element 40 (illustrated schematically in FIG. 1 ) is provided within the L-shaped opening area 24 . The gas-conducting element 40 is made of, for example, polyamide and is connected to the fabric of the airbag 10 in the opening area 24 . The gas-conducting element 40 is connected inside the airbag 10 , for example by sewing, when the airbag 10 is completed so that it can no longer slip to the side during final assembly. Sewing the gas-conducting element 40 in place is one method of connection, but the required connection can also be produced by welding or gluing.
[0026] Turning to FIG. 2 , the gas-conducting element 40 is provided with a forward section 42 and a rear section 45 . The cross section of the forward section 42 is arcuate and includes an opening directed toward an interior of the airbag 10 when connected to the airbag 10 . This results in a U-shaped cross section including two substantially parallel legs 42 a and 42 b. The gas-conducting element 40 is preferably sewn to the adjacent fabric in the area of the legs 42 a and 42 b.
[0027] FIG. 2 is a perspective illustration of the gas-conducting element 40 . Here the rear section 45 , has a substantially circular cross section. The forward section 42 , which has the arcuate or U-shaped cross section discussed above, is also easily recognized. During assembly, the gas generator 30 (not shown) is pushed through the rear section 45 and locks into a locking projection 46 . A slot 47 provides elasticity in the rear section 45 required for the locking projection 46 to function properly. The two legs 42 a and 42 b to which the airbag 10 is connected, are also shown.
[0028] FIGS. 3 and 4 depict the gas generator 30 inserted into the opening 16 of the airbag 10 . As can be seen, the gas generator 30 is elongated and rotationally symmetric. A first section 32 projects into the airbag 10 and is provided with discharge ports 33 . The discharge ports 33 are partially surrounded by the forward section 42 of the gas-conducting element 40 . The first section 32 is provided with a notch 34 , which is mechanically coupled to the locking projection 46 of the gas-conducting element 40 . The second section 35 is located outside of the airbag 10 .
[0029] It would also be conceivable to use an angled gas generator (not shown) as long as the first section 32 projecting into the airbag 10 is similarly elongated.
[0030] FIG. 4 a depicts a variation of the embodiment shown in FIG. 4 . As in the other embodiments, the gas-conducting element 40 is connected directly to the fabric of the airbag 10 by either sewing, gluing or welding. This connection is in the area of the legs 42 a and 42 b. A strap 50 , additionally secures the airbag 10 to the gas generator 30 . The strap 50 clamps the rear section 45 of the gas-conducting element 40 to the second section 35 of the gas generator 30 . The gas-conducting element 40 is thereby connected directly to the airbag 10 and to the gas generator 30 . This arrangement increases the strength of the connection between the gas generator 30 and the airbag 10 .
[0031] FIG. 5 depicts a longitudinal section through FIGS. 4 or 4 a along the sectional plane A-A. This view shows how the arcuate or U-shaped forward section 42 of the gas-conducting element 40 protects the fabric of the surrounding airbag 10 from a discharged gas 32 a. The forward section of the gas-conducting element 40 surrounds a certain area of the external wall of the first section 32 , so that the gas-conducting element 40 deflects the gas 32 a flowing out of the discharge openings 33 . The legs 42 a and 42 b direct the gas into the airbag 10 . The gas 32 a goes from the discharge ports located in the bottom section of the external wall into the airbag 10 .
[0032] It is also possible to see the connecting areas 43 by which the legs 42 a and 42 b are connected to the fabric of the airbag 10 . To simplify the connecting process, the legs 42 a and 42 b of an alternate embodiment of the forward section 42 of the gas-conducting element 40 can be arranged approximately perpendicular to a direction of gas flow from the arcuate portion of the forward section 42 to form an Ω-shaped cross section instead of the U-shaped cross section. Far ends of the D-shaped cross section are fastened to the fabric of the airbag 10 .
[0033] The locking of the gas generator 30 into the locking projection 46 provides mechanic feedback during assembly to ensure that the gas generator is located in the correct axial position. Because of the rotationally symmetrical design of the gas generator, radial alignment of the gas generator with respect to the curtain gas bag is not an issue. This simplifies the assembly of the gas generator 30 into the side curtain airbag 10 .
[0034] FIGS. 6 a and 6 b depict another exemplary embodiment of a gas-conducting element 40 . FIG. 6 b is a longitudinal section along the plane E through the forward section 42 of the gas-conducting element in FIG. 6 a. In the gas-conducting element of this exemplary embodiment, both the forward section 42 and the rear section 45 are tubular. The forward section 42 is provided with an elongated hole 48 through which at least a portion of the gas coming from the gas generator 30 flows into the airbag 10 . A base plate 49 is located in the plane of the elongated hole 48 . A longitudinal section through the forward section 42 , including the legs 42 a and 42 b projecting from the sides of the forward section 42 , result in the Ω-shaped cross section shown in FIG. 6 b. Braces 50 may optionally be provided to increase stability. Here the connection of the gas-conducting element 40 a to the fabric of the airbag 10 is in the area of the legs 42 a and 42 b permitting the entire area of the base plate 49 to be connected to the airbag 10 .
[0035] As a person skilled in the art will readily appreciate, the above description is meant as an illustration of implementation of the principles this invention. This description is not intended to limit the scope or application of this invention in that the invention is susceptible to modification, variation and change, without departing from spirit of this invention, as defined in the following claims. | An airbag module comprising a planar airbag and an elongate gas generator including discharge ports at least partially extending into the airbag. The airbag includes two side walls connected together by an edge region and made of fabric. An opening is disposed in the edge region of the airbag. The gas generator extends through the opening such that an elongate first section of the gas generator is arranged inside the gas bag. A gas-conducting element protects the fabric and is located in the airbag adjacent the opening. The gas-conducting element is made of plastic and includes a forward section having an arcuate cross section including an opening formed between at least two substantially parallel legs. | 1 |
RELATED APPLICATIONS
This application is the U.S. National Phase under 35 U.S.C. §371 of International Application No. PCT/JP2010/058696, filed on May 24, 2010, which in turn claims the benefit of Japanese Application No. 2009-134086, filed on Jun. 3, 2009, the disclosures of which Applications are incorporated by reference herein.
TECHNICAL FIELD
The present invention relates to a method for producing a standard sample that is necessary in quantitative analysis of red phosphorus contained in a resin (resin composition).
BACKGROUND ART
Recently, in consideration of environmental problems, non-halogen resin compositions in which a red-phosphorus flame retardant is blended with a non-halogen resin are used as flame-retarded resin compositions (Patent Literature 1). Consequently, the development of a method for analysis of red phosphorus useful for quality control in producing and shipping a product containing a red-phosphorus flame retardant, an acceptance inspection for purchasers of the product, and the like has been desired.
Red phosphorus is not dissolved in various types of solvents, and thus it is difficult to separate and collect red phosphorus. In addition, red phosphorus itself has no infrared absorption in an infrared spectrometer. Even when red phosphorus blended in a resin is analyzed using a Raman spectrometer, information about red phosphorus cannot be distinguished from the results. Furthermore, by an elemental analysis, for example, energy-dispersive X-ray (EDX) elemental analysis using an energy-dispersive X-ray fluorescence analyzer, discrimination between red phosphorus and organic phosphorus cannot be performed. Accordingly, in the case where organic phosphorus such as a phosphate ester may be contained, it is impossible to analyze red phosphorus only. Thus, red phosphorus contained in a resin cannot be analyzed by any of these methods.
Consequently, the inventor of the present invention developed, as a method for simply, rapidly, and reliably analyzing red phosphorus, in particular, red phosphorus contained in a resin as a flame retardant, a method in which a sample is gasified with a pyrolysis-gas chromatograph, and a measurement is then performed by gas chromatography, and furthermore, a mass spectrometer is used as means for detecting fractions of the gas chromatography, that is, an analytical method by pyrolysis-gas chromatography/mass spectrometry (pyrolysis-GC/MS), and proposed the method as Japanese Patent Application No. 2007-326840.
CITATION LIST
Patent Literature
Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2004-161924
SUMMARY OF INVENTION
Technical Problem
In the quantitative determination of red phosphorus in a resin performed by pyrolysis-GC/MS or the like, a calibration curve is prepared in advance by calculating area values of a peak corresponding to a retention time of red phosphorus using standard substances containing predetermined concentrations of red phosphorus, and this calibration curve is compared with an area value of a peak at the same retention time of a measurement sample. Accordingly, in order to accurately perform the quantitative determination, it is necessary to appropriately prepare standard samples and to prepare an accurate calibration curve. However, as for the analysis using pyrolysis-GC/MS, it has been difficult to appropriately prepare these standard samples.
Specifically, in the analysis by pyrolysis-GC/MS, when the amount of sample increases, a problem such as contamination of a detector occurs. Therefore, the amount of sample is 10 mg at most, and usually 0.5 mg or less. In addition, unlike standard solution samples, the concentration of which can be adjusted by dilution, since the standard samples are also solid samples, it is difficult to ensure and guarantee a uniform dispersibility. That is, unlike an elemental analysis in which the amount of sample is often about 100 mg, since a very small amount of solid sample is used, it is very difficult to ensure and guarantee a uniform dispersibility even if any of existing kneading technologies is employed.
The present invention has been made in order to solve this problem in the related art, and an object of the present invention is to provide a method for producing a standard sample in which a uniform dispersion of a predetermined concentration of red phosphorus is guaranteed even in a very small amount in the range of about 0.05 to 10 mg, preferably about 0.1 to 0.5 mg. Also, another object of the present invention is to provide a method for quantitatively determining red phosphorus contained in a resin by pyrolysis-GC/MS, in which this standard sample is used, and with which an accurate quantitative determination can be realized.
Solution to Problem
As a result of intensive studies conducted in order to solve the above problem, the inventor of the present invention has found that, by kneading a predetermined amount of red phosphorus in a resin to prepare a red-phosphorus-containing compound, and finely pulverizing the compound, it is possible to obtain a standard sample in which a uniform dispersion of a predetermined concentration of red phosphorus is guaranteed even in a very small amount in the range of about 0.05 to 10 mg, preferably about 0.1 to 0.5 mg, and completed the present invention.
Specifically, the present invention provides, as a first aspect of invention of the present application thereof, a method for producing a standard sample for quantitatively determining red phosphorus contained in a resin, the method including the steps of:
preparing a red-phosphorus-containing compound by weighing a predetermined amount of red phosphorus and uniformly mixing the red phosphorus in a resin;
decreasing the number of particles having a maximum diameter of 5 μm or more to 1/20 or less of the number of particles having a maximum diameter of 1 μm or more and less than 5 μm by pulverizing the red-phosphorus-containing compound; and
obtaining a standard sample by weighing 0.05 to 10 mg of the pulverized red-phosphorus-containing compound.
To prepare the red-phosphorus-containing compound, it is necessary to sufficiently uniformly blend (knead) red phosphorus in the resin. In addition, it is necessary to perform the preparation under the condition that the red phosphorus during the blending (kneading) does not sublime. Accordingly, it is necessary to determine the blending temperature to be not higher than 400° C., which is the sublimation temperature of red phosphorus, and not lower than a temperature (melting point) at which the resin can be melted. The type of resin used and the blending method are not particularly limited so long as a uniform kneading is ensured and the prepared compound is pulverized and can be used as a sample for pyrolysis-GC/MS.
The amount of red phosphorus kneaded in the resin is appropriately selected in accordance with a measurement range of the concentration of red phosphorus in a sample. For example, when the concentration of red phosphorus contained in a measurement target sample is assumed to be in the range of 100 to 1,000 ppm, the amounts of red phosphorus respectively corresponding to several points (for example, 100, 300, 500, 700, and 1,000 ppm) within this range are selected so that a calibration curve in the range of 100 to 1,000 ppm can be prepared.
The step of pulverizing the red-phosphorus-containing compound is a so-called fine pulverization, and the red-phosphorus-containing compound is pulverized until the number of particles having a maximum diameter of 5 μm or more is 1/20 or less of the number of particles having a maximum diameter of 1 μm or more and less than 5 μm. For the purpose of a more accurate quantitative determination, the number of particles having a maximum diameter of 5 μm or more is preferably smaller, and a case where particles having a maximum diameter of 5 μm or more are not contained is particularly preferable. When the shape of the pulverized fine particles is not a spherical shape, the particle diameter varies depending on the measurement direction. However, the term “maximum diameter” refers to the maximum among diameters when the diameter is measured in all directions.
The red-phosphorus-containing compound that has been finely pulverized in this manner is weighed in an amount of 0.05 to 10 mg to obtain a standard sample. Since the finely pulverized red-phosphorus-containing compound is mainly composed of fine particles having a maximum diameter of less than 5 μm, even in a very small amount of 0.05 to 10 mg, a uniform dispersion of red phosphorus in the standard sample is guaranteed.
An invention described in a second aspect of invention of the present application is the method for producing the standard sample for quantitatively determining red phosphorus contained in the resin described in a first aspect of invention of the present application, wherein, in the step of obtaining the standard sample, 0.1 to 0.5 mg of the pulverized red-phosphorus-containing compound is weighed. The amount of red-phosphorus-containing compound is preferably 0.5 mg or less in order to suppress contamination of a detector or the like, and is preferably 0.1 mg or more in order to obtain a more accurate calibration curve. Since the finely pulverized red-phosphorus-containing compound is mainly composed of fine particles having a maximum diameter of less than 5 μm, even in a very small amount of 0.1 to 0.5 mg, a uniform dispersion of red phosphorus in the standard sample is guaranteed.
An invention described in a third aspect of invention of the present application is the method for producing the standard sample for quantitatively determining red phosphorus contained in the resin described in a first or a second aspect of invention of the present application, wherein the red-phosphorus-containing compound is pulverized by striking the compound and applying a shear stress to the compound.
Hitherto, pulverization of a resin compound has been conducted by striking the compound with a hammer, crushing the compound with a mortar, or the like. With this method, however, it is impossible to perform pulverization until the pulverized resin compound is mainly composed of fine particles having a maximum diameter of less than 5 μm. However, by striking a resin compound and applying a shear stress to the resin compound, the resin compound can be finely pulverized until the pulverized resin compound is mainly composed of fine particles having a maximum diameter of less than 5 μm. In particular, a method in which crushing and pulverizing are performed while striking a resin compound and applying a shear stress to the resin compound with a three-dimensional eight-figure motion is preferable.
The present invention provides, in addition to the method for producing the standard sample, a method for quantitatively determining red phosphorus contained in a resin, wherein this standard sample is used. Specifically, the present invention provides a method for quantitatively determining red phosphorus contained in a resin, the method including the steps of:
producing a plurality of standard samples, the red phosphorus contents of which are varied, by the method for producing the standard sample for quantitatively determining red phosphorus contained in the resin described in any one of first to third aspects of invention of the present application;
pyrolyzing each of the standard samples to gasify the samples, separating each of the pyrolyzed samples into fractions by gas chromatography, and obtaining a peak intensity ratio by dividing a peak area value obtained with respect to a fraction of a retention time corresponding to red phosphorus by a sample weight;
preparing a calibration curve showing the relationship between the peak intensity ratio and the red phosphorus content;
pyrolyzing a measurement target sample to gasify the sample, separating the pyrolyzed sample into fractions by gas chromatography, and obtaining a peak intensity ratio A with respect to a fraction corresponding to red phosphorus; and
determining a red phosphorus content corresponding to the peak intensity ratio A using the calibration curve (a fourth aspect of invention of the present application).
Herein, the term “peak area value” refers to a peak area or peak height obtained with a detector. The detector is not particularly limited, and any detector commonly used in GC can be used. Preferably, a mass spectrometer (MS) is used. When the detector is a mass spectrometer, the peak area value is a value of a peak area or peak height of all ions or selected one or a plurality of ions in an ion chromatogram.
The retention time corresponding to red phosphorus varies depending on the measurement conditions. Therefore, it is preferable to determine the retention time in advance by conducting a measurement of elemental red phosphorus under the same conditions. In this quantitative method, the standard sample obtained by the method for producing a standard sample of the present invention, that is, the standard sample in which a uniform dispersibility of red phosphorus is ensured is used, and thus an accurate calibration curve is prepared and red phosphorus contained in a resin can be quantitatively determined accurately.
Advantageous Effects of Invention
According to the method for producing a standard sample for quantitatively determining red phosphorus contained in a resin of the present invention, it is possible to obtain a standard sample in which a uniform dispersion of a predetermined concentration of red phosphorus is guaranteed even in a very small amount of about 0.05 to 10 mg, preferably about 0.1 to 0.5 mg. Accordingly, this method is suitable as a method for producing a standard sample for pyrolysis-GC/MS, in which the amount of sample is about 0.05 to 10 mg, preferably about 0.1 to 0.5 mg. In addition, red phosphorus contained in a resin can be quantitatively determined accurately by the method for quantitatively determining red phosphorus contained in a resin of the present invention, in which the standard sample thus obtained is used.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a graph showing the relationship between the red phosphorus content and a peak intensity ratio of a GC/MS spectrum.
FIG. 2 is a scanning electron microscope (SEM) photograph of a pulverized product obtained in Example.
FIG. 3 is a SEM photograph of a pulverized product obtained in Comparative Example.
DESCRIPTION OF EMBODIMENTS
Next, embodiments for carrying out the present invention will be described.
A mixing method used in a step of preparing a red-phosphorus-containing compound is not particularly limited. Examples of the method include methods using a press kneader, a roll mixer, a twin-screw mixer, or a Banbury mixer. Examples of a resin that can be used include various types of resins such as thermoplastic resins, thermosetting resins, and rubbers.
Here, examples of the thermoplastic resins include polyethylene, polypropylene, polymethylpentene, polybutene, crystalline polybutadiene, polystyrene, polybutadiene, styrene-butadiene resins, polyvinyl chloride, polyvinyl acetate, polyvinylidene chloride, ethylene-vinyl acetate copolymers (ethylene-vinyl acetate (EVA), acrylonitrile-styrene (AS), acrylonitrile-butadiene-styrene (ABS), ionomers, acrylonitrile-acrylate-styrene (AAS), and acrylonitrile-chlorinated polyethylene-styrene (ACS)), polymethylmethacrylate, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymers, polyoxymethylene, polyamide, polycarbonate, polyphenylene ether, polyethylene terephthalate, polybutylene terephthalate, polyarylate (U-polymer), polystyrene, polyethersulfone, polyimide, polyamideimide, polyphenylene sulfide, polyoxybenzoyl, polyether ether ketone, polyetherimide, cellulose acetate, cellulose acetate butyrate, cellophane, and celluloid. Elastomers such as styrene-butadiene thermoplastic elastomers, polyolefin thermoplastic elastomers, urethane thermoplastic elastomers, polyester thermoplastic elastomers, and polyamide thermoplastic elastomers can also be used.
Examples of the thermosetting resins include formaldehyde resins, phenol resins, amino resins (urea resins, melamine resins, and benzoguanamine resins), unsaturated polyester resins, diallyl phthalate resins, alkyd resins, epoxy resins, urethane resins (polyurethanes), and silicon resins (silicone).
As for the fine pulverization of the red-phosphorus-containing compound, as described above, it is preferable to use a method of performing crushing and pulverizing by striking each sample and applying a shear stress to the sample with a three-dimensional eight-figure motion. Since the degree of crushing and the crushing capacity vary depending on the type of crushing medium, the number of vibrations, the crushing time, and the like, it is preferable to use an apparatus in which conditions such as the number of vibrations and the crushing time can be freely adjusted. An example of such an apparatus is a multi-sample precision sample pulverizer that is commercially available as a trade name “Multi-beads shocker” (manufactured by Yasui Kikai Corporation).
In the method of quantitatively determining red phosphorus contained in a resin of the present invention, the step of pyrolyzing a standard sample or a measurement sample to gasify the sample is performed by heating the sample to a temperature at which the sample is gasified or higher. Accordingly, the heating temperature is not lower than the sublimation temperature (416° C.) of red phosphorus. However, in order to reliably sublime red phosphorus and to perform analysis with a high accuracy, it is necessary to heat at a temperature equal to or higher than the decomposition temperature of the resin. The heating temperature is preferably about 600° C. to 800° C.
The heating time is not shorter than a time necessary for completely gasify the sample. The heating time varies depending on the heating temperature, the amount of sample, and the like, and is not particularly limited. Heating means is not particularly limited, and any heating means used in a usual pyrolysis-gas chromatograph can be used.
The sample pyrolyzed and gasified is introduced into a column of a gas chromatograph. Components in the sample are separated in accordance with a difference in the distribution equilibrium constant from that of a stationary phase, and eluted at times (retention times) that differ for respective components. Conditions for this gas chromatography are the same as conditions for usual pyrolysis-gas chromatography used in analysis of resins.
Either a packed column or a capillary column can be used as the column, but a capillary column is preferably used in qualitative analysis.
The sample eluted from the column of the gas chromatograph is introduced into a detector, and the presence or absence of elusion (fraction) in accordance with the retention time is detected. The analysis of red phosphorus is performed by detecting a fraction at a retention time corresponding to red phosphorus. For example, if a detection peak (fraction) is present at a retention time corresponding to red phosphorus, it is confirmed that red phosphorus is present in the sample.
The retention time corresponding to red phosphorus varies depending on operating conditions for the pyrolysis-gas chromatograph, the type of column, and the like. Therefore, prior to the measurement of a sample, the same analysis as that described above is performed using standard samples of red phosphorus so that the retention time corresponding to red phosphorus is determined in advance.
As described above, a mass spectrometer (MS) is preferably used as the detector. According to mass spectrometry, red phosphorus shows characteristic peaks at m/z=31, 62, 93, and 124. A calibration curve is prepared on the basis of the area of a peak or the height of a peak obtained from the standard samples, and a measurement sample is then measured. Quantitative analysis is performed on the basis of the calibration curve and the area of a peak obtained by the measurement of the sample.
The mass spectrometer includes an interfacing unit, which is a portion connected to the column of the gas chromatograph, an ion source that performs ionization of a sample, a mass separation unit, a detector, and the like. As an ionization method in the ion source, either an electron impact ionization (EI) method or a chemical ionization (CI) method can be employed. As an analyzer of the mass separation unit, either a magnetic sector-type analyzer or a quadrupole-type analyzer can be used. Furthermore, as a measurement mode in the detector, either the SCAN mode or the SIM mode can be used.
Next, embodiments for carrying out the present invention will be described by way of Example, but the scope of the present invention is not limited to only the Example.
EXAMPLE
[Preparation of Red-Phosphorus-Containing Compound]
A red phosphorus reagent manufactured by KANTO CHEMICAL CO., INC. was used as red phosphorus. This red phosphorus was added to an ethylene-ethyl-acrylate copolymer (EEA, trade name: EVAFLEX A701) so that the red phosphorus content was 100, 250, 500, or 1,000 ppm. Each of the mixtures was mixed with a roll mixer at 200° C. for five minutes to prepare four red-phosphorus-containing compounds, the red phosphorus contents of which were different from each other.
[Fine Pulverization of Red-Phosphorus-Containing Compound]
Each of the prepared red-phosphorus-containing compounds was finely pulverized with a multi-sample precision sample pulverizer (trade name: Multi-beads shocker manufactured by Yasui Kikai Corporation). Specifically, 1 g of each of the prepared four red-phosphorus-containing compounds was put in a 40-mL titanium pulverization container, and was pulverized under a liquid nitrogen condition at a number of vibrations of 3,000 rpm for 60 seconds. As a result, pulverized products were obtained in which the number of particles having a maximum diameter of 5 μm or more is 1/20 or less of the number of particles having a maximum diameter of 1 μm or more and less than 5 μm. FIG. 2 shows a SEM photograph of the pulverized product.
[Measurement of Pyrolysis-GC/MS and Preparation of Calibration Curve]
About 0.5 mg of each of the pulverized products thus obtained was weighed. Each of the samples was pyrolyzed (gasified) with the pyrolyzer under the pyrolysis conditions described below. The gasified sample was measured with gas chromatograph/mass spectrometry (GC/MS apparatus) described below. A peak area value for a peak at a retention time of 4.2 minutes was determined, and a ratio peak area value/measurement sample weight (hereinafter referred to as “peak intensity ratio”) was calculated. Mass spectrometry (MS) was conducted for the peak at the retention time of 4.2 minutes of the gas chromatograph obtained under these measurement conditions. As a result, peaks were obtained at positions of m/z=62, 93, and 124. Accordingly, the peak at a retention time of 4.2 minutes was identified as a peak of red phosphorus. In addition, according to a measurement result of pyrolysis-GC/MS conducted using elemental red phosphorus under the same conditions as those described above, the peak of the elemental red phosphorus was observed at a retention time of 4.2 minutes.
(Pyrolysis Condition)
A pyrolyzer manufactured by Frontier Laboratories Ltd. was used. The pyrolysis condition was 600° C.×0.2 minutes.
(GC/MS Apparatus)
An Agilent 6890 manufactured by Agilent Technologies, Inc. was used. Operating conditions for this apparatus are described below.
Column: HP-5MS (inner diameter: 0.25 mm, film thickness: 0.25 mm, length: 30 m)
Column flow rate: Helium (He) gas 1.0 mL/min
Temperature-increasing condition: The temperature was increased from 50° C. to 320° C. at a rate of 25° C./min and maintained at 320° C. for five minutes.
MS temperature: 230° C. (MS Source), 150° C. (MS Quad)
Interfacing unit temperature: 280° C.
Measurement mode: SCAN mode
Note that the measurement by mass spectrometry (MS) was performed in the range of m/z=33 to 550 in order to avoid peaks of oxygen.
The measurement was conducted for each sample three times. The results are shown in Table I.
TABLE I
The amount of red phosphorus blended (ppm)
100
250
500
1000
n = 1
Peak area: A
2168723
4860241
8491186
19768462
Amount of sample (mg): B
0.53
0.51
0.52
0.52
Peak intensity ratio A/B
4091930
9529884
16329204
38016273
n = 2
Peak area: A
2515051
4489632
8932955
18222040
Amount of sample (mg): A
0.52
0.51
0.53
0.51
Peak intensity ratio A/B
4836637
8803200
16854632
35729490
n = 3
Peak area: A
2096525
4037944
9632003
19495334
Amount of sample (mg): B
0.51
0.50
0.51
0.50
Peak intensity ratio A/B
4110833
8075888
18886280
38990668
Average
4346467
8802991
17356705
37578810
Standard deviation
424605
726998
1350451
1674022
cv
9.8%
8.3%
7.8%
4.5%
* The “peak area: A” represents an area value (signal intensity) of a peak at a retention time of 4.2 minutes corresponding to red phosphorus in a total ion chromatogram
As shown in Table I, the variation (cv) in the peak intensity ratio in the measurement that was performed three times was in the range of 4.5% (in the case where the amount of red phosphorus blended was 1,000 ppm) to 9.8% (in the case where the amount of red phosphorus blended was 100 ppm). FIG. 1 is a graph showing the relationship between the red phosphorus content (the amount of red phosphorus blended) in the resin and the average of the peak intensity ratios measured three times. As is apparent from FIG. 1 , there is a good relationship between the red phosphorus content in the resin and the peak intensity ratio in the GC/MS analysis, and the correlation coefficient thereof was 0.9965. This result showed that a quantitative analysis with a high accuracy could also be performed by the quantitative analytical method of the present invention.
Comparative Example
A pyrolysis-GC/MS measurement was conducted as in Example except that pulverized products prepared by pulverizing the red-phosphorus-containing compounds using a conventional pulverizer were used instead of using the pulverized products prepared by finely pulverizing the red-phosphorus-containing compounds. FIG. 3 shows a SEM image of the pulverized product. Furthermore, Table II shows the results when the measurement was conducted for each sample three times.
TABLE II
The amount of red phosphorus blended (ppm)
100
250
500
1000
n = 1
Peak area: A
1168723
476041
8491186
9768462
Amount of sample (mg): B
0.54
0.57
0.52
0.55
A/B
2164302
835160
16329204
17760840
n = 2
Peak area: A
3045051
2489632
8932955
13822040
Amount of sample (mg): B
0.52
0.55
0.58
0.51
A/B
5855867
4526604
15401647
27102039
n = 3
Peak area: A
2095525
2437944
2632003
25495334
Amount of sample (mg): B
0.56
0.50
0.56
0.50
A/B
3742009
4875888
4700005
50990668
Average
3920726
3412550
12143619
31951182
Standard deviation
1852260
2238908
6463020
17137415
cv
47.2%
65.6%
53.2%
53.6%
As shown in Table II, the variation (cv) in the peak intensity ratio in the measurement that was performed three times was in the range of 47.2% (in the case where the amount of red phosphorus blended was 100 ppm) to 65.6% (in the case where the amount of red phosphorus blended was 250 ppm), which was significantly larger than that of Example (example of the present invention). The comparison between Example and Comparative Example shows that, according to the present invention, quantitative determination of ref phosphorus contained in a resin can be performed with an accuracy significantly higher than that in the related art.
Reference Example 1
A pyrolysis-GC/MS measurement was conducted using an elemental red phosphorus reagent in a sample amount of about 0.1 mg instead of using a red-phosphorus-containing compound. Table III shows the results when the measurement was conducted three times.
TABLE III
Elemental red phosphorus
reagent
n = 1
Peak area: A
513955782
Amount of sample (mg): B
0.10
A/B
5139557820
n = 2
Peak area: A
587265799
Amount of sample (mg): B
0.11
A/B
5338779991
n = 3
Peak area: A
671866809
Amount of sample (mg): B
0.12
A/B
5598890075
Average
5359075962
Standard deviation
230337741
cv
4.3%
As shown in Table III, even in the measurement of the elemental red phosphorus, the variation (cv) was 4.3%, which shows that this analytical method itself causes a variation of about 5%. From the comparison between this result and the results shown in Table I, it is clear that the variations in the concentration in the standard samples in Example are very small. | Provided are a method for preparing a standard sample in which a uniform dispersion of a predetermined concentration of red phosphorus is guaranteed even in a very small amount, and an analytical method for quantitatively determining red phosphorus contained in a resin by pyrolysis-GC/MS, in which the standard sample is used. The method for producing a standard sample for quantitatively determining red phosphorus contained in a resin includes the steps of preparing a red-phosphorus-containing compound by weighing a predetermined amount of red phosphorus and uniformly mixing the red phosphorus in a resin; decreasing the number of particles having a maximum diameter of 5 μm or more to 1/20 or less of the number of particles having a maximum diameter of 1 μm or more and less than 5 μm by pulverizing the red-phosphorus-containing compound; and obtaining a standard sample by weighing about 0.05 to 10 mg, preferably about 0.1 to 0.5 mg of the pulverized red-phosphorus-containing compound. The analytical method is a method for quantitatively determining red phosphorus contained in a resin by pyrolysis-GC/MS, in which the standard sample is used. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. utility patent application Ser. No. 10/817, 356, filed on Apr. 2, 2004, and entitled “Inflation and Deflation Apparatus,” which in turn claimed priority from U.S. provisional patent application no. 60/511,047, filed on Oct. 14, 2003, and entitled “Inflation and Deflation Apparatus.” Both of these applications are incorporated wherein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to an apparatus for the inflation and deflation of air-filled bags, such as the dunnage bags commonly used to cushion cargo loads in truck trailers, railroad cars, and the like.
[0003] Inflatable dunnage bags are a common means of cushioning loads shipped via truck trailer, railroad car, or other typical shipping container, particularly where the cargo only partially fills the container and shifting during transport might cause damage. Typical dunnage bags in use today are constructed of one or more layers of paper surrounding a plastic lining. The paper serves to protect the bags from tearing, and thus a greater number of layers may be used in applications where the risk of damage to the dunnage bag is greater. A valve for filling the dunnage bag, usually constructed of plastic, is attached through a hole cut in the bag during manufacture. The bags are shipped flat from the manufacturer, and must be inflated by shipping personnel as containers are loaded with cargo.
[0004] The tools currently in use to fill dunnage bags with air are often simply converted tire inflation tools, which are attached to a hose leading from a source of compressed air. Some specialized tools are available for dunnage bag deflation, such as taught by U.S. Pat. No. 5,437,301 to Ramsey. In the use of such devices, the bag is first placed in the space that it will occupy as cargo is loaded into a container, and the inflation device is attached to the bag valve. The bag is then filled with air. until an appropriate air pressure within the bag is achieved. The inflation tool may connect with the bag valve through a ball-lock quick-disconnect attachment, which may be engaged and disengaged by simply sliding a ring on the attachment point up or down. Filling is thus a relatively simple operation, requiring only a few seconds of the operator's time.
[0005] A significant limitation of the current inflation tools is that they present no way to rapidly deflate a dunnage bag once the cargo is ready to be unloaded. The valve assembly in some such bags may be unscrewed to release air pressure within the bag, but because the bags are fairly rigid (owing to the protective paper covering) they tend not collapse simply due to the equalization of air pressure inside and outside of the bag. The bags cannot be quickly and conveniently reduced to a flat configuration such as they are shipped from the manufacturer. As a result, the standard industry practice is for shipping and receiving personnel to simply cut the bags with a utility knife in order to deflate them quickly for removal.
[0006] Dunnage bags are not reusable once cut, and thus they are generally considered to be a one-use, disposable commodity. Significant cost savings could be realized by the reuse of these dunnage bags. This could be rendered practical by devising a means to rapidly and easily deflate a dunnage bag without damaging the dunnage bag. The bags must be restored to the flat shape they held prior to their original use, so that they can be easily and compactly stored.
[0007] The prior art does include previous attempts to develop deflation tools for dunnage bags. U.S. Pat. No. 5,437,301 to Ramsey, discussed above, teaches a rotating valve actuator that selectively allows the flow of compressed air across an air passage connected to the dunnage bag in order to facilitate deflation. U.S. Pat. No. 6,053,222 to Peters teaches a dunnage bag deflation tool that uses a high-pressure air source to open the dunnage bag air valve, thereby allowing deflation, and also suck air out of the bag by discharging the air through a venturi tube. A venturi tube in its simplest form is an air passage with a region of restricted diameter. According to the Bernoulli inverse relationship between air velocity and pressure, passage of air through the restricted region of a venturi tube creates a low-pressure region. This low-pressure region results in a negative pressure or suction effect that may be used to draw air out of an attached container. Peters teaches two different embodiments of the deflation device, which differ by the means through which the device may be switched from inflation to deflation mode. One device calls for the operator to simply place a thumb over the venturi tube exit, thereby blocking that means of egress for the high-pressure air and directing the high-pressure air into the bag. The other embodiment incorporates a manually set bi-stable switch set at the entrance to the venturi tube, which prevents air from ever entering the venturi tube and thus forcing high-pressure air in the direction of the dunnage bag valve.
[0008] U.S. Pat. No. 5,454,407 to Huza et al. teaches another apparatus to both inflate and deflate a dunnage bag. This device incorporates the venturi effect as part of an automatic pressure sensing system, but relies on hand pressure directly to the dunnage bag for deflation. Other devices to inflate and deflate different types of chambers are known in the art, such as that taught by U.S. Pat. No. 5,947,168 to Viard for inflation and deflation of an air mattress.
[0009] Each of these devices suffers from important limitations. While the Peters device allows for the inflation and deflation of a dunnage bag using an integrated tool, its control mechanisms are of limited practicality. The operator of such a device should ideally be able to quickly turn on and off the source of high-pressure air, and quickly adjust the mode setting of the device to either inflate or deflate a dunnage bag. Ideally, the necessary controls would be simple and easily manipulated. The use of the operator's thumb to maintain the Peters device in the inflation mode would quickly result in operator fatigue. Given the large number of cargo containers that may be loaded and unloaded in a typical shipping facility during an operator's work shift, this rudimentary control mechanism would quickly prove unworkable. The use of a switch at the entrance of the venturi tube is an improvement, but because of its design and position on the device would be prone to failure. Furthermore, the overall design of the device lacks any means of dissipating or quieting the flow of high-pressure air out of the venturi tube during deflation of a dunnage bag; it would result in a violent burst of air moving directly toward the operator. This situation raises significant safety concerns. The air escaping in this manner would also create a great deal of noise, which may be not only uncomfortable for the operator but also may raise a safety issue itself. Finally, the design of the device does not incorporate any convenient means of holding the device during inflation and deflation; this is an important safety concern as well, since if the valve connection should fail then the device would be propelled backward at great speed due to force of air. In this situation, the device would likely swing in an arc due to the attached (but flexible) air hose, and could strike the operator or a bystander with great force, potentially causing severe injury or property damage.
[0010] The limitations of the prior art are overcome by the present invention as described below.
BRIEF SUMMARY OF THE INVENTION
[0011] The present invention comprises an inflation and deflation device with a control mechanism and operational features that make it convenient, practical, and safe for use by operating personnel. Switching of the device from an inflation to a deflation mode is achieved by merely switching the position of the dunnage valve bag connector fitting from one end of the device to the other. Air flow is turned on or off by sliding a control mechanism near the handle of the device, which provides a sure grip for the operator. This mechanism results is a simple and reliable means by which the operator may change the mode of operation of the device. Air exiting the device is muffled through the barrel and is directed away from the operator. This device both reduces the likelihood of injury to the operator due to a violent rush of air during deflation, and also dampens the noise created by air rushing out of the device during deflation.
[0012] It is therefore an object of the present invention to provide for a single, integrated tool for the inflation and deflation of dunnage bags and like containers.
[0013] It is a further object of the present invention to provide a device for the inflation and deflation of air-filled bags with a simple means for inflation/deflation selection and a simple means of turning on and off the flow of air to the device.
[0014] It is also an object of the present invention to provide a device for the inflation and deflation of air-filled bags that disperses air ejected from the device during deflation mode away from the operator.
[0015] It is also an object of the present invention to provide a device for the inflation and deflation of air-filled bags that improves on the safety of existing devices.
[0016] It is also an object of the present invention to provide a device that reduces the noise created by the flow of air from the device during deflation mode.
[0017] These and other features, objects and advantages of the present invention will become better understood from a consideration of the following detailed description of the preferred embodiments and appended claims in conjunction with the drawings as described following.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0018] FIG. 1 is a perspective view of a preferred embodiment of the present invention.
[0019] FIG. 2 is an exploded perspective. view of a preferred embodiment of the present invention.
[0020] FIG. 3 is a partial cut-away elevational view of a preferred embodiment of the present invention in the “inflation” configuration.
[0021] FIG. 4 is a cut-away view of the preferred embodiment of the present invention in the “deflation” configuration.
[0022] FIG. 5 is a detail cut-away view of a preferred embodiment of the present invention in the “on” configuration.
[0023] FIG. 6 is a detail cut-away view of a preferred embodiment of the present invention in the “off” configuration.
DETAILED DESCRIPTION OF THE INVENTION
[0024] Referring to FIGS. 1 and 2 , the major components of a preferred embodiment of the present invention may now be described. Inflation barrel 10 comprises a tube with an open bore. Removably attached to inflation barrel 10 in the “inflation” configuration, as depicted in FIGS. 1 and 2 , is valve connector assembly 12 . Valve connector assembly 12 is fashioned so as to provide a selectively lockable and unlockable engagement with a dunnage bag inflation valve (not shown). The valve connector assembly 12 may preferably be constructed as a ball-lock quick-disconnect valve connector as described in U.S. Pat. No. 5,437,301 to Ramsey, which is incorporated herein by reference. o-rings 14 is seated within an annular groove on the interior of inflation barrel 10 , thereby providing an airtight seal between inflation barrel 10 and valve connector assembly 12 . In the preferred embodiment, valve assembly 12 is held in place by set screw 16 . Set screw 16 extends through a hole in the side of inflation barrel 10 and part-way into the interior of inflation barrel 10 . As valve connector assembly 12 is inserted into inflation barrel 10 , a notch in the interior end of valve connector assembly 12 must be aligned with set screw 12 in order for valve connector assembly 12 to be fully seated. Once engaged, valve connector assembly 12 may be turned with respect to inflation barrel 10 , whereby set screw 16 extends into the groove near the end of that portion of valve assembly 12 that extends within inflation barrel 10 . Valve assembly 12 may not be removed until it is again turned with respect to inflation barrel 10 such that the notch of valve assembly 12 and set screw 16 are aligned.
[0025] Body 18 is of a generally annular shape, and receives inflation barrel 10 through its interior, holding inflation barrel 10 in place by means of set screws 22 . In the preferred embodiment, inflation barrel 10 extends completely through body 18 and extends slightly from the opposite side of body 18 . Attached to body 18 by means of screws 24 is handle 20 . Handle 20 is hollow to allow air flow, as will be explained following, but is preferably of an ergonomic shape on its exterior. The purpose of handle 20 is to allow the operator to maintain a firm grip on the device during use, and thus cross-hatching or other means may preferably be used to improve the ability of a user to grip the device at handle 20 . At its distal end, handle 20 includes female threads to receive air passage 26 . Air passage 26 , preferably constructed of steel or brass for strength, controls the passage of air from an air hose (not shown) into the device. Air passage 26 comprises two rows of air holes 28 passing through the walls of air passage 26 , and a barrier (not shown in FIG. 1 but illustrated in FIGS. 5 and 6 as will be described below) that blocks the passage of air through air passage 26 between the rows of air holes 28 . In the preferred embodiment, the barrier is formed of a single piece of metal as air passage 26 ; the barrier is formed by machining the hollow center of air passage 26 using two bores drilled toward each other but not quite meeting in the middle of air passage 26 .
[0026] Fitted slideably over air passage 26 is annular slide 30 . Slide 30 comprises slots on its interior to receive two o-rings 32 , one positioned towards each end of slide 30 . Slide 30 has freedom of movement in a longitudinal direction with respect to air passage 26 . In the preferred embodiment, slide 30 's longitudinal movement is blocked near the distal end of air passage 26 by a flared end designed to receive a standard wrench, and blocked near the proximal end of air passage 26 by a keeper 34 , which is fitted into a slot sized to receive it on the exterior of air passage 26 . Fitted into the female threads at the distal end of air passage 26 is air fitting 36 , which is designed to receive a hose fitting of the standard quick-disconnect type as commonly employed for equipment supplying pressurized air.
[0027] Again referring to FIG. 2 , fitted annularly within the bore of inflation barrel 10 is air distributor 38 . Distributor o-rings 40 are placed neither either end of distributor 38 to block the flow of air around either end of distributor 38 at the inner wall of the bore of inflation barrel 10 . Distributor 38 further comprises a number of distributor inlets (not shown); the preferred embodiment comprises six distributor inlets, but alternative embodiments may include any number of such inlets. The distributor inlets are preferably located at the edge of the base of the truncated cone formed by the inner portion of distributor 38 . As will be explained more fully below, air may pass through inflation barrel 10 through the inlets of distributor 38 and thereby pass through the device.
[0028] Deflation barrel fitting 42 is threaded into inflation barrel 10 at the end extending slightly from body 18 . Deflation barrel fitting 42 comprises a hollow air passage that gradually widens as it extends away from body 18 . Deflation barrel fitting 42 achieves an air-tight fit with inflation barrel 10 because it sits against the o-ring 40 that is fitted at the adjacent end of distributor 38 o-ring 46 is fitted at the other end of deflation barrel fitting 42 , at the point where deflation barrel 44 threadably fits onto deflation barrel fitting 42 . Thus an air-tight fit is achieved at each end of deflation barrel fitting 42 . Like deflation barrel fitting 42 , deflation barrel 44 comprises a hollow air passage at its interior. This passage, however, is wider and straight-sided in that portion of deflation barrel 44 furthest from deflation barrel fitting 42 , but is sized down at the opposite end and shaped to receive valve 48 . Valve 48 is capable of sliding over a short distance within deflation barrel 44 , for reasons as will be explained in the discussion of the operation of the device following. A set screw 16 extends transversely through deflation barrel 44 near its distal end, in a position congruent with that of the set screw 16 fitted into inflation barrel 10 , and similarly an o-ring 14 is fitted in a groove at the interior and near the distal end of deflation barrel 44 , in order to provide an air-tight fit with bag valve connector assembly 12 When the device is operated in deflation mode.
[0029] The principal components of the device, including inflation barrel 10 , body 18 , handle 20 , deflation barrel fitting 42 , and deflation barrel 44 may be formed of any sufficiently strong, rigid material, the stronger plastics being the preferred material due to their light weight and relatively low manufacturing cost. Likewise, distributor 38 and valve 48 may also be constructed of strong, lightweight materials such as plastics. For purposes of strength, aluminum, brass or other metals are used in the preferred embodiment for the construction of air passage 26 and slide 30 . The various o-rings in the preferred embodiment are of the types commonly found commercially, constructed of rubber or a like resilient material.
[0030] Referring now to FIGS. 5 and 6 , the method of turning a preferred embodiment of the present invention “on” and “off” (that is, allowing the flow of compressed air through the device or stopping the flow of compressed air through the device) may be described. FIG. 5 depicts the device in the “on” position, with the arrows indicating the path of air flow through the device, and FIG. 6 depicts the device in the “off” position. It may be seen that sliding slide 30 towards the distal end of air passage 26 causes the flow of air to be interrupted. Since the inner hollow section of air passage 26 does not pass completely through air passage 26 , air must flow out through one row of air holes 28 and then back in through the other row of air holes 28 in order to reach the proximal end of air passage 26 . As shown in FIG. 6 , the distal row of air passages 28 are cut off from the proximal row of air holes 28 by slide 30 and associated o-rings 32 . In FIG. 5 , however, when slide 30 is in the “open” position, air may flow into air passage 26 , out through the distal row of air holes 28 , into the cavity formed by the space between the outer surface of air passage 26 and the inner surface of slide 30 , then back into air passage 26 through the lower row of air holes 28 . From this point, the air may flow into handle 20 and on through the device. As previously discussed, the travel of slide 30 is limited by air passage 26 at its distal end and by keeper 34 at the proximal end of air passage 26 .
[0031] Referring now to FIGS. 3 and 4 , the method of operating the preferred embodiment of the invention in inflation mode and deflation mode may now be described. The device is shown in inflation mode in FIG. 3 . Bag valve connector assembly 12 is fitted at the end of inflation barrel 10 , held in place by set screw 16 . Air flows from air passage 26 as described above, entering handle 20 . Air then flows through an opening in body 18 , through a matching opening in inflation barrel 10 , and into a cavity between the outer surface of distributor 38 and the hollow interior of inflation barrel 10 . The inlets of distributor 38 allow air to pass through distributor 38 , into inflation barrel 10 , and then into bag valve connector assembly 12 . Air may then pass into the bag to be filled from that point when the bag valve is connected to the device. Air pressure formed within deflation barrel fitting 42 forces valve 48 to move away from body 18 , thereby closing and sealing the opening through deflation barrel 44 .
[0032] FIG. 4 depicts the preferred embodiment of the invention in deflation mode. In this mode, bag valve connector assembly 12 is fitted not to inflation barrel 10 , but to deflation barrel 44 . Again, bag valve connector assembly 12 is preferably held in place by a set screw 16 . Air flows from air passage 26 as described above entering handle 20 . Air then flows through an opening in body 18 , through a matching opening in inflation barrel 10 , and into a cavity between the outer surface of distributor 38 and the hollow interior of inflation barrel 10 . The inlets of distributor 38 allow air to pass through distributor 38 , into inflation barrel 10 , and then exit the device. The length of inflation barrel 10 serves to muffle the sound of air exiting the device, and also directs the air away from the operator to avoid injury.
[0033] Air is drawn from the dunnage bag through bag valve connector assembly 12 and into deflation barrel 44 because the insertion of bag valve connector assembly 12 forces valve 48 into the open position. As illustrated in FIG. 4 , the end of bag valve connector assembly 12 pushed against the distal end of valve 48 , forcing it toward body 18 . This prevents the closure of valve 48 due to air pressure within deflation barrel fitting 42 . Furthermore, air is drawn from the dunnage bag, by way of bag valve connector assembly 12 , deflation barrel 44 , and deflation barrel fitting 42 , due to the venturi effect created by distributor 38 . As may be noted in FIG. 4 , distributor 38 includes a cone-shaped section that functions according to the well-known Bernoulli principle, creating a negative air pressure in the region behind distributor 38 . Thus the device creates a suction that draws air from the dunnage bag, along with the pressurized air entering the device at air fitting 36 , through inflation barrel 10 and out of the device. Using typical compressed-air sources such as industrial-sized air compressors, the preferred embodiment of the device is capable of reducing a standard-sized dunnage bag to a flat shape appropriate for storage and reuse in only a few seconds.
[0034] The present invention has been described with reference to certain preferred and alternative embodiments that are intended to be exemplary only and not limiting to the full scope of the present invention as set forth in the appended claims. | A tool allowing both the inflation and deflation of air-filled bags such as dunnage bags is disclosed. The tool comprises a sliding control to easily and safely turn the flow of air on and off. The tool is switched from inflation to deflation mode by moving the bag connecting valve from one end of the device to the other. | 1 |
This is a continuation of co-pending application Ser. No. 44,682 filed on May 1, 1987 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to improved prestressed concrete tanks and their construction and, more particularly, relates to elongated prestressed concrete tanks which may be designed and adapted for more efficient utilization of the area of construction site.
2. Description of the Prior Art
The present invention is particularly useful in connection with prestressed composite tanks. Such tanks are widely used for storage of liquid and similar purposes and normally include a light gauge steel shell diaphragm which is encased in layers of a cementitious material such as shotcrete. While these tanks have become known as prestressed concrete tanks, the term concrete is used generically and in practice includes shotcrete (which may contains small rocks). The shotcrete utilized in the construction of prestressed composite tanks is generally applied by a pressure gun and thus rocks of any substantial size cannot be tolerated. The cementitious material that is utilized in connection with the present invention, generally consists of a mixture of cement, sand and water, although small rocks might be incorporated into the mixture so long as the same are small enough to flow through the nozzle of the gun.
The prestressed composite tanks which are known have generally been of circular construction. Thus, after the steel shell is encased in layers of a cementitious material, the outer periphery may be wrapped with prestressing wire which, after tightening, is enclosed by a cover coating of shotcrete. Stretching or tightening of the wire imposes centripetal forces on the wall of the tank and thus, due to the circular configuration of the wall, the entire wall is placed into circumferential compression. Such prestressed tanks and a method for producing the same are disclosed in United States Letters Pat. No. 3,822,520 which is owned by the assignee of the present application.
The '520 patent also discloses a method for sealing the joints between adjacent panels of the steel shell. This method involves forming joints so that they provide a hollow channel which runs vertically of the joint, and thereafter pumping the channel full of a sealant. This method for sealing panels is utilized in the preferred tanks and construction methods of the present invention and the entirety of the disclosure of the '520 patent is hereby specifically incorporated by reference.
As set forth above, prestressed composite tanks have traditionally been circular so that prestressing is accomplished simply by pulling a prestressing wire all the way around the tank to thereby place the entire circumferential extent of the wall into circumferential compression. Moreover, it has been known to wrap a single wire spirally around the tank so that a significant vertical portion of the tank may be prestressed with a single wire. Such methods are well known and have been utilized for a long period of time and such prestressing methodology is fully disclosed and described in U.S. Pat. No. 2,370,780, the entirety of the disclosure of which is also hereby incorporated by reference.
The fact that known prestressed composite tanks are circular has been a problem in the industry on construction sites that are not of a size and shape to efficiently facilitate and accommodate circular tanks, particularly when large gallonages are required. That is to say, long and narrow sites may not accommodate the construction of a circular tank of the required size. Accordingly, the use of elongated tanks which might more efficiently be fitted into the construction site have been suggested. However, elongated tanks by necessity include elongated straight wall sections, which until the present invention, were subject to cracking from shrinkage during curing and hardening of the cementitious material.
SUMMARY OF THE INVENTION
The problem of uncontrolled shrinking and resultant cracking during curing and hardening of elongated straight wall sections constructed of cementitious material has been solved through the use of the present invention which provides, in an elongated, prestressed tank, a straight, preshrunk, substantially crackless, elongated, wall section; means for exerting end-to-end preshrinking compressive forces on the straight wall section; a generally semicircular, prestressed end wall having a pair of circumferentially spaced extremities, one of the extremities of the end wall being disposed in generally abutting relationship with respect to one end of the straight wall section; and means exerting circumferentially directed compressive prestressing forces on said end wall.
The straight walls are preshrunk as a result of application of the principles and concepts of the present invention. As is usual in shotcrete type construction, the walls are kept moist and under conditions which retard shrinkage until high strength is achieved. The walls are kept moist by playing the same with streams of water. After curing has proceeded to a point where the high strength is achieved, the streams of water are discontinued and the wall is placed into end-to-end compression. The compressed wall is permitted to shrink or contract or shorten while the compressive forces are maintained on the ends thereof. After the process of shrinking under compression has proceeded for a sufficient period of time, a straight, elongated, preshrunk, substantially crackless wall is produced.
In a more specific aspect, the invention provides means for exerting end-to-end compressive forces upon the straight wall section which comprises a plurality of tensioned, threaded rods extending longitudinally through the straight wall section and nut means threadably engaged on each rod and operable for bearing against an end of the straight wall section. The invention also provides means for exerting circumferentially directed compressive forces on the end wall which comprises a plurality of wire tendons stretched peripherally around the end wall in a position to exert centripetal forces on the wall. In this regard the centripetal (radially inwardly directed) forces acting in conjunction with the circular shape of the wall create circumferentially directed compressive forces in the wall.
In a particularly preferred form, the invention provides a keystone joint construction at the juncture point between the straight walls and the curved end walls which comprises a plate secured against one end of the straight wall by the nuts on the threaded rod, clamp means attached to the plate for securing the ends of the tendons utilized for compressing the semicircular end walls and a generally trapezoidally shaped block of cementitious material. The keystone joint is configured and arranged for transfer of forces between a straight wall section and a semicircular end wall.
To facilitate preshrinking of the straight wall section, the structure includes friction reducing means disposed beneath the straight wall section and permitting at least slight longitudinal movement of at least portions of the straight wall to facilitate preshrinking of the latter without substantial cracking. In a particularly preferred form of the invention, the means beneath the wall section comprises a plurality of plastic sheets disposed to minimize friction between the base of the wall section and its footing.
In its most efficient form, the invention provides means for exerting sufficient compressive pressure on the ends of the straight wall section during hardening thereof to preshrink the wall without substantial cracking, in combination with means disposed beneath the wall section comprising a plurality of plastic sheets which minimize friction at the base of the wall section and facilitate at least slight longitudinal movement of at least portions of the straight wall so that the wall may contract during the preshrinking operation as a unitary object and without substantial cracking.
The invention also provides an elongated, prestressed concrete tank comprising at least a pair of elongated, generally parallel, laterally spaced, preshrunk, substantially crackless, straight wall sections; means for exerting end-to-end compressive forces on the straight wall sections; at least a pair of prestressed end walls with each end wall interconnecting corresponding ends of the straight wall sections; and means exerting compressive prestressing forces on each of the end walls. More particularly, the invention provides a tank wherein at least one of the end walls is semicircular and spans the distance between the ends of the straight wall sections at one end of the tank. The invention further provides means exerting compressive forces on the semicircular end wall which comprise a plurality of wire tendons stretched peripherally around the end wall in a position to exert centripetal forces on the end wall and thus impose circumferentially directed compressive forces thereon.
In an even more particularized aspect of the invention, a tank is provided which includes a third longitudinally extending straight wall section disposed between the preshrunk wall sections. In this aspect of the invention, one of the end walls of the tank comprises a pair of side-by-side, semicircular wall portions, one of which spans the distance between and interconnects one end of the third wall section and the corresponding end of one of the preshrunk wall sections and the other wall portion spans the distance between and interconnects the same end of the third wall section and the corresponding end of the other preshrunk wall section. In this form of the invention, the means exerting compressive forces on the end walls comprises a respective set of tendons stretched peripherally around each of the semicircular wall portions in a position to exert centripetal forces on each portion and thus impose circumferentially directed compressive forces thereon. The invention further provides a keystone joint element which comprises a plate secured to an end of the third wall section, a respective clamp means for each set of tendons for securing an end of each of the tendons of each set and a generally trapezoidal block of cementitious material, all for the purpose of efficiently transferring forces between the various walls which converge at the keystone.
The invention also provides a method for constructing an elongated, prestressed concrete tank which comprises: forming at least a pair of generally parallel, laterally spaced, elongated, straight wall sections of a cementitious material; subjecting each straight wall section to end-to-end compressive forces and allowing such straight wall sections to preshrink without substantial cracking under the influence of said end-to-end forces during the hardening and shrinking of the cementitious material; forming end walls of cementitious material in abutting relationship to the corresponding ends of the preshrunk wall sections; and prestressing the end walls by applying compressive forces thereto. In accordance with the invention, the method involves the step of subjecting the straight walls to end-to-end compressive forces by providing a plurality of tensioned threaded rods extending longitudinally through the wall section and threading a nut onto each rod and into bearing and force transferring relationship against an end of the wall section. In accordance with the invention, at least one of the end walls is formed in a semicircular shape and the step of prestressing the same comprises stretching a plurality of tendons peripherally therearound in a position for exerting centripetal forces thereon. In accordance with the method of the invention, the step of allowing the straight wall section to preshrink preferably includes constructing the wall on a friction reducing surface permitting at least slight longitudinal movement of at least portions of the wall section relative to its footing. In this regard, in its particularly preferred form, the invention provides for the wall to be constructed atop a plurality of plastic sheets to minimize friction at the base of the wall section between the wall and its footing during the preshrinking of the wall section so that the wall section may shrink as a single unitary body and thus preclude substantial cracking during the preshrinking operation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a prestressed composite tank which embodies the principles and concepts of the present invention;
FIG. 2 is a vertical cross-sectional view of a straight, preshrunk, substantially crackless, elongated, wall section of the tank of the invention taken along the view line 2--2 of FIG. 1;
FIG. 3 is a vertical cross-sectional view of a straight, preshrunk, substantially crackles, elongated wall section constructed in accordance with the principles and concepts of the present invention and taken along the view line 3--3 of FIG. 1;
FIG. 4 is a vertical cross-sectional view of a semicircular end wall of the tank of FIG. 1 and taken along the view line 4--4 of FIG. 1;
FIG. 5 is a horizontal cross-sectional view of the semicircular end wall taken along the view line 5--5 of FIG. 4;
FIG. 6 is an enlarged, fragmentary, horizontal cross-sectional view of a keystone element constructed in accordance with the principles and concepts of the present invention and embodied in the tank illustrated in FIG. 1;
FIG. 7 is an enlarged, fragmentary view of a U-plate embodied in the keystone element of FIG. 6 and with the cementitious material removed for increased clarity;
FIG. 8 is an enlarged, horizontal cross-sectional view of a portion of the tank of FIG. 1 illustrating the abutment between an end wall and an outside straight tank wall;
FIG. 9 is an enlarged, horizontal cross-sectional view of a portion of the tank of FIG. 1 illustrating the construction of the keystone used for joining end wall sections to a baffle wall;
FIG. 10 is an elevational, schematic view illustrating the interconnection between the keystone element of FIG. 9 and the baffle wall; and
FIG. 11 is a partial elevational view of one end of the tank of FIG. 1 and illustrating the end wall prestressing procedure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An elongated prestressed concrete tank structure which embodies the concepts and principles of the present invention and which was constructed utilizing the methodology provided by the present invention is illustrated in FIG. 1 where it is broadly identified by the reference numeral 20. Structure 20 comprises a pair of side-by-side tanks 22 and 24 which share a common wall 26. The tanks 22 and 24 have respective outer walls 28 and 30 and respective large diameter end walls 32 and 34 at one end of the structure. Each of the tanks 22 and 24 has a respective end wall 36 or 38 which is disposed at the opposite end of the tank from the end walls 32 and 34. As can be seen viewing FIG. 1, the end walls 36 and 38 each comprise a pair of side-by-side, semicircular end wall portions, each having a diameter which is essentially one-half of the width of the respective tank.
The tanks 22 and 24 are constructionally and operationally identical except that they are mirror images of one another. Accordingly, a detailed description of tank 22 will provide an adequate and appropriate description also of tank 24. In this regard, tanks 22 and 24 are actually operationally completely separate entities and are combined in the tank structure 20 simply to minimize the costs of construction by sharing common wall 26. Manifestly, if the tanks were not combined in the manner illustrated in FIG. 1, common wall 26 could be constructed identically with wall 28. In this same regard, wall 26 is constructed just as though it were an external wall since from time to time one or the other of tanks 22 and 24 may be emptied while the other remains in operation and thus the wall 26 must be capable of withstanding a full hydraulic load. In any event, the following description will focus upon tank 22 with the understanding that the description is equally applicable to the tank 24.
Tank 22 includes an internal central baffle wall 40 and a U-shaped baffle wall 42. Thus, tank 22, which may be used as an aeration tank, provides an elongated flow path for fluid materials introduced through an inlet 44. Fluid materials entering tank 22 through inlet 44 flow in the direction of the arrows in FIG. 1 and exit from tank 22 via effluent box 46. As shown, tank 22 also includes semi-circular baffle 47 which assists in directing the flow of fluid around the free end 48 of central baffle wall 40.
As can be seen viewing FIG. 1, end wall 36 spans the distance between walls 26 and 28. Moreover, end wall 36 consists of a pair of side-by-side semicircular wall portions 50 and 52. Thus, wall portion 50 spans the distance between and interconnects straight wall section 28 and baffle wall 40 while wall portion 52 spans the distance between and interconnects wall 26 and baffle wall 40.
Wall portion 50 and outer wall 28 are interconnected at a point 54 by means of structure illustrated in FIG. 8 and which will be described in more detail hereinafter. Wall portions 50 and 52 and wall 40 are interconnected at a point of connection 56 by structure illustrated in FIG. 9 which will also be described in further detail hereinbelow.
End wall 38, similarly to end wall 36, consists of a pair of side-by-side semicircular wall portions 58 and 60, as can best be seen in FIG. 1, and semicircular wall portion 52, semicircular wall portion 58 and common wall 26 are interconnected at a point of connection 62 by structure illustrated in FIG. 6 which will also be described hereinafter. For completion of the description in this regard, end wall 32 and outer wall 28 are interconnected at a point of connection 64 which has a structure that is essentially the same as the structure at point of connection 54. Moreover, end walls 32 and 34 and common wall 26 are interconnected at a point of connection 66 having a structure which is essentially the same as the structure of the tank at point of connection 62. Thus, it can be seen that end wall 32 is a generally semicircular wall which spans the distance between straight walls 26 and 28 and interconnects the ends of the latter. In this regard, end wall 32 has one extremity which abuts the end of wall 28 at point of connection 64 and another extremity which abuts the end of wall 26 at point of connection 66.
Viewing FIG. 2, it can be seen that straight wall 28 is generally trapezoidal in cross-sectional configuration and has a thickness at its bottom which is greater than its thickness at its top. This wall is of the type that is conventionally known as a cantilever wall and the same is designed to withstand the hydraulic forces imposed by water contained within the tank.
Wall 28 consists of a steel shell diaphragm 68 covered on both sides by a cementitious material. The joints between adjacent sections of the diaphragm may be sealed with a pumped grout as disclosed in the '520 patent identified above. Vertical and horizontal reinforcing steel, identified broadly by the reference numeral 70, may be incorporated into the wall in a manner which is conventional and well known to those skilled in the art. A series of threaded rods 72, 74, 76, 78, 80, 82, 84 and 86 are positioned to extend horizontally through the entire extent of the wall for a purpose that will be explained hereinafter.
Wall 28 is constructed atop a working slab or footing 88 which may be constructed of reinforced, poured concrete and plastic sheeting 90 is interposed between slab 88 and the bottom of wall 28 for the entire length and width of the latter. The purpose and function of plastic sheeting 90 and the sheeting itself will be described more fully hereinbelow. Tank 20 has a floor 92 which may be constructed of reinforced concrete. The construction of the floor 92 is conventional and does not form a part of the present invention. Suffice it to say, however, that floor 92 is constructed only after all of the staight, preshrunk walls have been completed.
The cross-sectional construction and configuration of wall 26 is illustrated in FIG. 3. This wall is also of a cantilever type construction and thus has a thickness which increases from top to bottom. Wall 26 is constructed of reinforced cementitious material and incorporates a diaphragm 94, which again may be of the type illustrated in the '520 patent. In FIG. 3, the reinforcing steel has been deleted for improved clarity; however, those skilled in the art will appreciate that wall 26, like wall 28, should include reinforcing steel. Like wall 28, wall 26 also incorporates a series of horizontally extending threaded bars 96, 98, 100, 102, 104, 106, 108 and 110 which extend through the entire length of the wall for a purpose to be explained hereinafter. Also, wall 26 is constructed atop a working slab 112 of reinforced poured concrete and plastic sheeting 114 is interposed between slab 112 and the bottom of wall 26 and extends throughout the entire length and width of wall 26. Also seen in FIGS. 2 and 3 is the interrelationship between floor 92 and walls 26 and 28. The floor 92a of tank 24 is also seen in FIG. 3.
The construction of end wall portion 52 is illustrated in FIGS. 4 and 5. Wall portion 52, like the other walls of the tank, incorporates a metal diaphragm 116 which may be a pumped joint diaphragm as illustrated in the above-mentioned '520 patent. Wall 52 includes both vertical and horizontal reinforcing steel which is deployed in a conventional manner, and the wall is prestressed, in a manner which will be explained in greater detail hereinbelow, utilizing prestressing wires or tendons 118. In this connection, the prestressing operation is known per se for circular tanks and is fully described in both the '520 patent and the '780 patent cited above. These principles are adapted for the present invention for use with semicircular wall sections. Such prestressing is for the purpose of applying centripetal forces to the entire periphery of the wall and thus place the same in circumferential compression. Wall 52 is constructed on a working slab 120 and cooperates with floor 92 and the other external walls to provide a water tight tank.
Manifestly, the construction of wall portion 50 and the construction of end wall 32 are similar to the construction just described for wall portion 52. Accordingly, it is not necessary to describe the construction of these walls in detail at this point. Suffice it to say that these walls also incorporate steel diaphragms similar to the diaphragm 116 and the same are placed into circumferential compression by the tension of prestressing wires or tendons similar to the wires 118 of wall portion 52.
With reference to FIG. 6, the details of the construction of the structure 20 at connection point 62 is described. FIG. 6 is essentially a horizontal cross-sectional view taken at the level of bar 96 in wall 26. Thus, bar 96 and the edge of diaphragm 94 are visible, as are horizontal reinforcing steel rods 120. These latter are conventional and are identified simply for clarification. Also visible in FIG. 6 is the edge of the steel diaphragm 116 of wall 52 and one strand of the prestressing wire 118 for prestressing and placing wall 52 into compression.
Included in the construction of the tank at connection point 62 is a U-shaped plate 122 which is shown in greater detail in FIG. 7. In FIG. 7 it can be seen that U-shaped plate 122 includes a base plate element 124 and a pair of spaced plate members 125 and 127 which extend outwardly from element 124 and carry respective clamp structures 126 and 128. The plate 122 and its components are elongated and extend vertically for the entire height of wall 26. In this regard, plate element 124 has a respective hole therein for each of the bars 96 through 110 to extend through. Prestressing wires 118 are clamped into clamp 126 and are thus secured to U-shaped plate 122. Prestressing wires 118 are each provided with a wire splice element 130 which simply wraps around the wire and frictionally engages the same in a manner to prevent relative longitudinal movement of the wire relative to the splice element. The purpose of the wire splice element at this position is to provide better bonding between the wires and the cementitious material which will be applied over and around the prestressing wires during the construction of the keystone.
The construction at point of connection 62 also includes a series of anchor plates 132 and nuts 134, the nuts 134 being threadably engaged on the ends of threaded bars 96 through 110 and disposed in bearing relationship relative to a respective plate 132 and plate element 124, all for a purpose which will be described in detail hereinafter. Also included in the construction at point of connection 62 are respective threaded couplings 136 and extensions 138 for each bar 96 through 110, a second series of anchor plates 140 similar to plates 132 and a second series of nuts 142 which are similar to the nuts 134. Again, the purpose of these various elements will be described in detail hereinbelow where the constructional procedure is set forth in detail.
In the space between walls 52 and 58, the various components shown in FIG. 6, and which form a part of the construction at point of connection 62, are coated with a cementitious material such as shotcrete. Prior to the application of the shotcrete, grout tubes 144 and 146 may be installed at each horizontal bar. The purpose of the grout tubes will be explained hereinbelow.
The construction of the tank at the point of connection 54 is illustrated in detail in FIG. 8. FIG. 8 is a cross-sectional view of straight wall 28 and end wall 36 at their point of connection 54. The view is taken approximately at the level of bar 80 which extends horizontally through wall 28 as shown. Also illustrated in FIG. 8 are the diaphragm 68 of wall 28 and the diaphragm 51 of wall 50. At the point where the circumferential extremity of wall 36 abuts the end of wall section 28, an anchor plate 150 is provided for each bar 72 through 86 and a nut 152 is threadably engaged on the end of each rod 72 through 86 in a position for bearing against its respective plate 150 and pressing the same against the end of wall 28. Again, the exact purpose and function of each of these components will be described in greater detail hereinbelow during the description of the procedure for constructing the tank.
A grout tube 154 is installed adjacent each bar prior to shotcreting. In this connection, it is to be understood that for purposes of the present construction involving walls that are approximately 205 feet long, each of the horizontally extending bars 72 through 86 in wall 28 and each of the bars 96 through 110 in wall 26 should preferably be a 1" steel rod and the same should preferably be provided with an annular sheath for the full length of the bar. The sheath is simply a thin metal tube, approximately 11/4" in ID, which is placed around the bar leaving a small annular space between the bar and the inside of the sheath. Both the inside and the outside surfaces of the sheath and the outside surface of the bar are provided with spiral irregularities, in a manner known to those skilled in the art, so that when the annular space between the sheath and the bar is filled with a grout and the outside of the sheath is coated with shotcrete, an excellent bond is provided between the bar and the wall and the ba is protected from corrosion. The tubes 154 provide access for pumping grout into the space between the sheath and the bar after the cementitious material has been applied.
The structural details of the tank at point of connection 56 are illustrated in FIG. 9. Here the construction is similar to the construction at point 62, as illustrated in FIG. 6, except that in this case there is no necessity for the inside nuts and anchor plates since there is no necessity for preshrinking central baffle wall 40 to prevent cracking because the latter will have equal hydrostatic pressures on each side in service. Since the wall is not a hydrostatic pressure resisting wall, shrinkage cracking is not a significant problem. A series of threaded horizontal bars 156 through 170 are incorporated into the end of wall 40 adjacent connection point 56 and FIG. 9 is a horizontal cross-sectional view looking downwardly from about the level of bar 156. The vertical placements and horizontal extensions of bars 156 through 170 are illustrated schematically in FIG. 10 where it can also be seen that each bar is provided with a sheath which covers a portion of its length, the sheaths otherwise being as described above in connection with bars 72 through 86 and bars 96 through 110. Grout tubes 173 and 175 are provided for grouting each bar 156 through 170 for the purposes set forth above.
The bars 156 through 170 are provided with respective couplings 172 and threaded extensions 174. Also provided at point 56 are anchor plates 176 similar to the plates 140 at point 62 and a series of nuts 178 which are threadably engaged on respective extensions 174. A U-shaped plate 180, which may be identical with the U-shaped plate 122 illustrated in FIG. 7, is provided and the same includes respective clamp means for anchoring the prestressing wires or tendons 118 for wall portion 52 and the corresponding wires or tendons 119 for wall portion 50.
With reference to FIG. 11, it can be seen that prestressing wires 119 extend around end wall 50 from point of connection 56 where they are securely clamped by U-shaped plate 180, to an angle element 182 attached to wall 28. A series of holes are provided in angle 182 and each wire 119 is secured to angle 182 by a device known in the relevant art as a torpedo. Such holding devices simply provide a one-way friction element which permits insertion of the wire in one direction but frictionally prevents removal of the wire in the other direction. There are a number of such devices available commercially and they are used simply to facilitate anchoring of the wires. After the wires are secured at one end by the torpedos at angle 182 and at the other end by the clamp on U-shaped plate 180, the same may be tightened at the mid-point of end wall 50 by procedures described in greater detail hereinbelow.
The prestressing wires 118 around end wall 52 are secured at one end (at connection point 56) by the clamp means of U-shaped plate 180 and at the other end (at connection point 62) by the clamp 126 of U-shaped plate 122. Similarly, the prestressing wires for end wall 32 are secured at one end (near connection point 64) by an angle and torpedos similar to the angle 182 and its corresponding torpedos, and at the other end (at point 66) by a clamp which forms a part of a U-shaped plate identical with U-shaped plate 122. In this regard, the construction of the tank at connection point 66 is essentially the same as the construction of the tank at connection point 62. Moreover, the construction of the tank at connection point 64 is essentially the same as the construction of the tank at connection point 54. The only differences being those resulting from the differences in the degrees of curvature of the walls since wall 32 has a diameter which is about twice as large as the respective diameters of wall portions 50 and 52.
With reference to wall 28, the construction procedure is as follows. First, the working slab or footing 88 is cast from a cementitious material, which may be a concrete, and the upper surface is finished to provide a smooth and level surface. Plastic sheeting 90 is then placed on top of slab 88 in a manner to extend across the full width and length of slab 88. Essentially any sort of sheeting which is rugged and which reduces the friction between the bottom of the wall and the surface of the footing and which therefore facilitates slight longitudinal movements of the bottom of the wall relative to the footing will suffice. However, for a wall constructed of cementitious material and which is approximately 151/2 feet tall and 205 feet long, it has been found that a system using 8 sheets of 4 mil thickness polyethylene is capable of facilitating the necessary movement of the bottom of the wall during preshrinking. At least in part, the friction is reduced by the slippage of one such sheet of plastic on another such sheet of plastic. Useful polyethylene film is available commercially and is known in the trade as visqueen sheeting.
Working slab or footing 112 for wall 26 is also cast to provide a very smooth and level upper surface and plastic sheeting 114 is placed across the full width and length of slab 112. In general, sheeting 114 should preferably be the same as sheeting 90. Working slabs are also constructed for each of the other walls; however, it is only the walls 26, 28 and 30 which need to be preshrunk and which therefore need be provided with the friction reducing plastic sheeting means to permit at least slight longitudinal movement of at least portions of the wall section during the preshrinking operation to be described in detail hereinafter.
After all of working slabs or footings have been constructed, and the plastic sheeting applied to the working slab footings for walls 26, 28 and 30, the walls themselves may be constructed. The floor 92 of the tank may be cast after the completion of all of the walls.
After the footings are completed, the straight walls and end walls are constructed. The procedure for construction at point of connection 62 may be more fully understood with reference to FIG. 6. First, the diaphragm 94 for the straight wall is erected. Thereafter the threaded bars 96 through 110 are placed in position along with their sheaths. The U-shaped plate 122 is positioned with the ends of the bars 96 through 110 extending through the holes in plate 122, and a respective anchor plate 132 and nut 134 is placed on each bar. The faces of the wall are then shotcreted and the reinforcing steel is put in place during the shooting. The walls are completed to the back of plate element 124 of U-shaped plate 122 which is positioned at the preselected end point for the wall. As a preliminary procedure, the grouting tubes 146 are installed prior to the shooting of the wall with shotcrete so as to extend outside the wall 26 after the same has been completed up to the back of the plate element 124.
The other end of wall 26, at connection point 66, is constructed in an essentially identical manner so that upon the completion of the shooting of the wall there is a U-shaped plate at each end of the wall and a respective anchor plate and nut positioned at each end of each of the bars 96 through 110. The nuts are then in a position to be tightened to place the wall into compression at the appropriate time.
As is usual in shotcrete type construction, it is often desirable to allow the cementitious material to achieve high strength under conditions where the wall is moist and shrinkage is retarded. Known procedures are utilized for testing the strength. The structure is kept in a moistened condition to keep significant shrinkage from occurring during the curing process until the cementitious material has aged enough so that high strength has been achieved. This may be done by simply playing streams of water on the wall during the curing operation. It may take a month or so for the wall to cure appropriately to achieve the required high strength so that the process can then be continued.
After the curing has proceeded to the point where the strength of the cementitious material is sufficiently high, the water streams are discontinued and the wall is put into end-to-end compression by tensioning the bars 96 through 110 and tightening the nuts at the end of the bars. The tensioning of bars 96 through 110 may be accomplished using conventional equipment such as a hydraulic pump equipped with a grabber element which grasps the end of the bar and pulls it longitudinally. The nuts are brought up snug while the tension is being applied. A total compressive force in the order of 600,000 pounds was found to be operable in the case of a wall which is 205 foot long and 151/2 foot high. The wall is then permitted to shrink or contract or shorten (these terms are used synonymously) while the compressive pressures are maintained on the ends of the wall. The preshrinking process may take as much as three weeks and during this period a cementitious wall which is about 205 feet long will shrink approximately 17/8 inches. In this regard, the cementitious materials which are used in connection with tanks of the sort to which the present invention pertains generally have coefficients of shrinkage ranging from 0.0004 to 0.0015 inches per inch.
Manifestly, the plastic sheeting 114 positioned beneath wall 26 reduces the friction at the base of the wall so as to permit slight longitudinal movements of the wall as a unitary structure to occur. This facilitates longitudinal shrinkage of the wall and essentially prevents cracking. It has been found that the end-to-end compressive forces imposed on the ends of the walls utilizing bars like the bars 96 through 110, nuts like the nuts 134, anchor plates like the plates 132 and U-shaped plates like the plates 122, in combination with a reduction of friction such as is made possible through the use of plastic sheeting like the sheeting 114, makes the construction of preshrunk walls possible in the essential absence of cracking.
After the completion of the preshrinking phase for wall 26, the circumferential diaphragms for the walls 52 and 58 are placed in appropriate positions as shown in FIG. 6. Similarly, the diaphragms for the walls 32 and 34 are positioned at the other end of the tank in the same manner. At the same time the reinforcing steel is positioned adjacent each semicircular diaphragm. The outer sides of the end walls are then shot with shotcrete or the like, the joints to be pumped in accordance with the '520 patent are cleaned and taped, including the joints between the diaphragm and the U-shaped plate.
After the pump joints have all been cleaned and appropriately taped, the end walls are shotcreted. Thereafter, the prestressing wires are positioned to extend around each end wall with the ends of the prestressing tendons restrained by the clamps of the corresponding U-shaped plate, or the angles on the outer walls as the case may be.
The foregoing description presupposes that all of the other walls of the tank have been completed. To the extent that the construction of the other walls differs from the construction of wall 26, such differences will be noted specifically hereinafter. Meanwhile, it is simply presumed, for purposes of the present description, that the wall 28, the wall 30 and the wall in the center of tank 24 have each been constructed and have been preshrunk similarly to the preshrinking of the wall 26. In any event, the prestressing wires or tendons are stretched around each end wall with a tension, for the time being, which is just enough to hold each wire tightly in place.
At this point, the nuts 134 and the anchor plates 132 may be removed from the U-shaped plate 122 and retained for use later as will be described. A respective coupling 136 and a respective threaded extension 138 may be placed on the free end of each of bars 96 through 110. Thereafter, the area between walls 52 and 58 is filled with cementitious material 200 to a position beyond the clamps holding the ends of the prestressing wires. In this regard, each prestressing wire may be wrapped with a splice element to insure an appropriate bond between the cementitious material 200 and the wires and the cementitious material will extend to a point which is substantially beyond the length of the splice. As explained above, the splice is a commercially available device which wraps around the wire, and once in place it prevents relative longitudinal movement of the wire relative to the splice element. Generally speaking, these splice elements are utilized to hold loose ends of a wire together; however, in the present case, the wire is not held together by the splice but rather the splice is used simply to prevent longitudinal shifting of the wire and thus provide a better bond between the wire and cement block 200.
Prior to completion of the filling of the area between walls 52 and 58 with cementitious material 200, a grout tube 144 may be positioned as shown in FIG. 6 adjacent each of the extensions 138. Cementitious material 200 extends outwardly to a point near the ends of extensions 138 and a flat surface 200a is provided at that point. An anchor plate 140 (which may in fact be an anchor plate 132 which was removed) is placed on surface 200a at each extension 138 of the concrete and a nut 142 (which may be a nut 134 which was previously removed) is placed on the end of each of the extensions 138 and the latter are placed into tension and the nuts 142 tightened. The U-shaped plate 122 and the cementitious material 200 filling the area between end walls 52 and 58 up to the backs of anchor plates 142 present a generally trapezoidal keystone 202 which operates to transfer forces between the semicircular walls 52 and 58 and the straight wall 26. In this regard, the keystone 202 may be provided with reinforcement steel as is appropriate.
Since the construction at point 66 is essentially the same as the construction at point 62, a keystone which is essentially identical to keystone 202 is provided at connection point 66. After these keystones have been completed and the extensions 138 tensioned, and nuts 142 tightened, the prestressing wires are all tensioned at the mid-point of each semicircular wall. The tensioning is done utilizing a conventional technique and device whereby the wire is grabbed left and right, the wire is snipped in two and drawn from each side and a splice is installed to hold the snipped ends of the wire together. After the prestressing tendons have been appropriately snipped, tightened and spliced, the wires are covered with a coating of cementitious material. This procedure is conventional in the prestressed composite tank art. After the walls have been completed, bars 96 through 110 and the extensions 138 may be grouted from the outside through grouting tubes 144 and 146. Finally, the area between walls 52 and 58 may be filled with shotcrete to a level to cover the ends of the extensions 138 as well as the anchor plate 140 and the nuts 142 and provide a finished appearance.
With reference to FIG. 8, the construction of connection point 54 between straight wall 28 and end wall 36 is illustrated. In completing this structure, the straight wall 28 is first completed with the diaphragm 68 disposed inside of the bars 72 through 86. The diaphragm and the threaded bars 72 through 86 are then covered with shotcrete and the wall 28 is built up to an appropriate thickness complete with reinforcing bars pursuant to conventional techniques. As in the case of wall 26, the wall 28 is kept in a moistened condition by spraying it with water until the concrete has achieved the required high strength. After high strength has been achieved by appropriate curing of the wall using essentially the same procedure as was used in connection with wall 26, anchor plates 150, which are essentially the same as anchor plates 132, are placed at the end of the wall as shown in FIG. 8 and the entire wall is subjected to end-to-end compression by tensioning bars 72 through 86 and tightening of the nuts 152. In this regard, a nut 152 is threadably received on the end of each of the bars 72 through 86. Moreover, it should be appreciated that the construction of the tank at point of connection 64 is essentially the same as the construction of the tank at point 54, and thus there are plates similar to the plates 150 at the end of wall 28 adjacent point of connection 64 as well as a nut for each of the bars. The bars may be tensioned and the nuts tightened at either end to provide the compressive forces necessary during the preshrinking operation.
Manifestly, the construction of the wall 28 may be carried on contemporaneously with the construction of wall 26. Also, the wall 30 may be constructed essentially at the same time. In any event, it will be apparent to one of skill in the art that the walls 26, 28 and 30 must all be constructed and fully preshrunk before the construction of the end walls can be accomplished. The placing of each straight, hydraulic pressure containing wall into end-to-end compression during the preshrinking stage coupled with the presence of the anti-friction means in the nature of the plastic sheeting beneath the base of the wall to reduce friction, allows the shrinking of the wall to take place without substantial cracking of the wall, to thus provide a preshrunk, substantially uncracked wall. Baffle wall 40, as well as the corresponding baffle wall disposed between walls 26 and 30, must be fully constructed before the end walls can be completed, at least in the structure which has been described in the present application.
As has been explained previously in connection with the construction of wall 26, each of the bars 72 through 86 of wall 28 is provided with a sheath, and grouting tubes 154 are provided for each bar so that the annular space in each sheath may be grouted upon completion of the wall.
To complete the construction and prestressing of the semicircular walls, angles such as the angle 182 are attached to the wall 28 at a point which is sufficiently beyond the connection point to insure appropriate transfer of forces between the semicircular end wall and the straight wall to which it is attached. In the case of a 205 foot long straight wall section, it has been found to be appropriate for the angle to be placed a distance about 30 feet from the connection point. After the prestressing wires are anchored and tensioned, the same are coated with an outer coating of shotcrete.
The construction at point of connection 56 is essentially the same as the construction at point of connection 62 except that in this case, the wall 40 need not be preshrunk since it is not a wall which must resist hydraulic pressure. Rather, wall 40 is simply a baffle wall utilized for the purpose of directing the flow of fluid in the tank during operation. Thus, the bars 156 through 170 do not need to run the full length of the wall and instead are used simply to secure the keystone 204 at connection point 56 and facilitate appropriate transfer of forces between wall 40 and end walls 50 and 52.
The constructional details of the tank at connection point 56 are shown in FIG. 9. During the construction of the tank, the diaphragm 41 is erected and the threaded bars 156 through 170 are positioned along with their respective sheaths and corresponding grout tubes as set forth above. The bars 156 through 170 do not extend the entire length of the wall 40 and the positioning thereof is shown schematically in FIG. 10. After the diaphragm, the bars 156 through 170 and the reinforcing steel for wall 40 have been positioned properly, the cementitious material for the wall is applied by shotcreting. The cementitious material is applied and the wall is completed up to the base of U-shaped plate 180. The diaphragms for walls 50 and 52 are then erected and reinforcing steel is positioned for the semicircular walls. The walls are completed as before. Couplings 172 and extensions 174 are installed on each of the bars 156 through 170 and the keystone 204 is cast between walls 50 and 52. After keystone 204 has been cast, the prestressing wires are tensioned and spliced as set forth above and the wires are coated with cementitious material. Thereafter, the anchor plates 176 and the nuts 178 are installed and the bars 156 through 170 are placed in sufficient tension so that forces may appropriately be transferred between the walls connected by the keystone 204 at connection point 56. Grout is pumped through the grout tubes to grout the bars and a cover coat is shot over the anchor plates 176 and nuts 178, essentially to the configuration illustrated in FIG. 9.
As can be seen viewing FIG. 1, the walls 26, 28, 32, 50 and 52 define an elongated prestressed concrete tank. The walls 26 and 28 are each comprised of straight, preshrunk, substantially uncracked, elongated wall sections, and end walls 32 and 50 each comprise a generally semicircular, prestressed end wall having a pair of circumferentially spaced extremities, one of which is disposed in generally abutting relationship with respect to an end of a straight wall section. Moreover, the tank 20 comprises a pair of elongated, generally parallel, laterally spaced, preshrunk, substantially uncracked straight wall sections 26 and 28 and a pair of prestressed end walls 32 and 36. | A prestressed concrete tank includes a pair of generally parallel, laterally spaced, straight concrete wall sections which are preshrunk by the application of compressive forces. Straight wall sections are constructed on top of a footing covered with a plurality of plastic sheets to reduce friction so that limited longitudinal movements of at least portions of each wall section are facilitated during the preshrinking operation. The ends of the tank comprise semicircular walls which are prestressed using wire tendons extending peripherally around the wall and tightened to impose centripetal forces on the wall and thereby place the same into circumferential compression. The walls each comprise a substantially vertical steel shell diaphragm with a layer of cementitious material such as shotcrete on each side thereof. The steel diaphragm comprises a plurality of panels having vertical edges which cooperate to form joints, a shotcrete cover is shot over both faces of the diaphragm, and a sealing material is pumped into the joints after application of the shotcrete to substantially fill voids and other hollow places within the layers of cementitious material. | 4 |
BACKGROUND OF THE INVENTION
[0001] (a) Field of the Invention
[0002] The present invention is related to a biodegradable plastic master batch and its preparation; and more particularly, to a totally biodegradable plastic master batch and its preparation methodology.
[0003] (b) Description of the Prior Art
[0004] There are various degradable plastic batches including optical, optical-oxygen, high-starch containment, and high calcium carbonate optical-oxygen biodegradable plastic batches generally available in the market. However, all those plastic batches contain more or less polyolefin composition including polyethylene, polypropylene, and polyvinyl-chloride (PVC) that prevent incomplete degradation when disposed. Therefore, the problem of resultant “white pollution” has not yet been satisfactorily solved.
[0005] Research of documents published in recent years including Introduction of Polycaprolactone (PCL) Characteristics & its Prospective Applications, an academic presentation in the Fourth Convention of XingJiang, XingJiang Institute, Chinese Academy of Science (CAS) www.xib.ac.cn; Biodegradable Plastics—Study of PHA Production Technology, Collection of Presentations in the Incorporation of Degradable Plastics Subcommittee, CPPIA, China, November 2001; and “Microbe Synthetic PHA Polymer Master Batch”, Communications of Degradable Plastics, Vol. 33, Dec. 20, 2002, has revealed that any polycyclic-lactone plastic master batch containing ester (with its structural formula:
[0000]
[0006] such as PGA (formula: [C 2 H 2 O 2 ] n , and structural formula,
[0000]
[0007] PCL, (formula: [C 6 H 10 O 2 ] n , and structural formula,
[0000]
[0008] and PHA (structural formula,
[0000]
[0009] Wherein, n=1, 2, 3, 4; usually n−1 if it refers to β-hydrogen fatty acid esters; M, the extent of polymerization; R, is side-bonds and may be in different groups) can be fast degraded by enzyme secreted by microbes; and the ester radicals on its primary bond can be easily broken into carbon dioxide and water to achieve complete biodegradation. However, those master batches are prevented from significant promotion in the market due to higher unit production cost (as high as US$6.00˜8.00/kg) and a nature of resources not readily available.
[0000]
(Molecular Formula of Ester Radical)
[0010] Starch is a natural polymer, and it is usually found the presences of hydroxyl group and peroxide bonds as shown in the molecular formula below its structural formula also as illustrated below is similar to that of polyester that permits total biodegradation.
[0000]
[0011] Molecular formula of Starch Structural formula of Starch
SUMMARY OF THE INVENTION
[0012] The primary purpose of the present invention is to provide a plastic master batch that is at comparatively lower unit production cost and is totally biodegradable and its preparation methodology. The plastic master batch of the present invention can be used for the synthesis into various degradable plastic products.
[0013] To achieve the purpose, a totally biodegradable plastic mast batch is comprised of (by weight): 100 parts of starch, 3˜12 parts of coupling agents, 5˜20 dispersing agents, 30˜90 parts of polycyclic-lactone, 12˜35 parts of plasticizer, 0.2˜1.0 parts of anti-caking agent, 3˜18 parts of chemical degradation promoter, and 0.2˜2.1 parts of oxidization promoter. Wherein, the coupling agent relates to Titanate or diisocyanate; and the dispersing agent relates to glycerin, corn oil or clean oil. When applied in the preparation of the totally degradable plastic master batch, the polycyclic-lactone relates to the one in its molecular structure that features shorter bond greater rigidity, and higher hardness of the repetition unit (PGA or PLA preferred); the polycyclic-lactone, to the one in a molecular structure that features longer bond, greater resilience, and higher tenacity in the repetition unit (PCL or PHA preferred; as for the latter, butyl β-polycarboxyl group is preferred in its molecular formulas as follows; the plasticizer, to CH-PA or EVA oligomer wax; oxidization promoter, to low temperature heat or unsaturated fatty acid; the promoter of chemical degradation, to carboxylate of transition metal; and anti-caking agent, to sodium silico-aluminate.
[0000]
[0014] The purpose of adding plasticizer and dispersing agent into the composition of the totally biodegradable plastic master batch of the present invention is to lower the plastication temperature of the polycyclic-lactone for better incorporation with starch through the mixture and refinery process.
[0015] In the composition of the totally biodegradable plastic master batch of the present invention, the addition of the coupling agent is a must for modification to seek better binding between the starch and the polycyclic-lactone since there are three hydrophilic groups to the bond of the starch molecule while such hydrophilic groups are present only on the tail of the bond in the molecule of the polycyclic-lactone.
[0016] The preparation of the totally biodegradable plastic master batch of the present invention includes the following steps:
1. Refining and dehydration of Starch: starch, water, and anti-caking agent are mixed and blended into a thick solution, the solution is then poured into a disperser machine for 20˜30 minutes to grind the starch into that with a grain size of 1-10 μm with the refining temperature controlled within the range of 40˜60° C., the thick solution of the primary starch is then dehydrated through an ultra-filtration unit; the dehydrated primary starch is further mixed with glycerin or corn oil and blended into thick solution before being poured into the dispersing machine for 40˜50 minutes to be refined to that with a grain size less than 1 μm at a temperature controlled within the range of 50˜70° C., and the secondary starch is then dehydrated through the ultra-filtration unit to reduce its water containment to be less than 0.5% before being placed into a centrifuge to separate the oil from the powder; finally, the resultant starch power and the coupling agent are poured into a high-speed kneader to be kneaded for 20˜30 minutes to come out of a modified starch powder 1. 2. Mixing: Polycyclic-lactone, plasticizer, dispersing agent, oxidization promoter, chemical degradation promoter in sequence are added into the modified starch 1 availed from Step 1 is added into the kneader for 20˜30 minutes. 3. Molding: the product availed from Step 2 is then placed into a dual-screw, dual-exhaust extrusion granulator to come out the plastic master batch.
[0020] Following the molding process as described in Step 3 for the preparation of the totally biodegradable plastic master batch, a packaging step of vacuum sealing may be provided to ensure that the product will not get wetted and deteriorated during the storage and transportation, thus to further ensure of easy process for the final product.
[0021] In the course of the preparation of the totally biodegradable engineering plastic master batch, the molding temperature in Step 3 is controlled within the range of 130˜160° C. (respectively, Unit 1 at 130° C.; Unit 2, 135° C.; Unit 3, 140° C.; Unit 4, 145° C.; Unit 5, 150° C.; Unit 6, 155° C.; Unit 7, 160° C., and the head, 155° C.); and in the preparation of the totally biodegradable film plastic master batch, the molding temperature in Step 3 is controlled within the range of 80˜120° C. (respectively, Unit 1 at 80° C.; Unit 2, 88° C.; Unit 3, 93° C.; Unit 4, 98° C.; Unit 5, 105° C.; Unit 6, 112° C.; Unit 7, 118° C.; Unit 8, 120° C., and the head, 115° C.).
[0022] The grinder dispersing machine referred in Step 1 is the SK80-2A dispersing machine supplied by Kang Shen Machinery Works, Jiangyin; the ultra-filtration unit referred in Step 1, HDZC-006-1 by Blue Cross, Tientjin; the centrifuge referred in Step 1, GKH1250-1 by Tiengong Technology Development, Hofei; the high-speed kneader referred in Step 2, GL500/1600 by Twilight Group, Sundong; and granulator referred in Step 3, TE-95 by KEYA, Najing. The primary reason for the selection of the dual-screw, dual-exhaust granulator is that both of the polycyclic-lactone and the starch in their molecular structures contain massive carboxyl radicals and thus are highly water absorbent; the extrusion by the dual-screw mixer will cause both of the polycyclic-lactone to be well fused and bonded to each other for the formation of n intervened network structure. Furthermore, the dual exhaust of the granulator effectively clear off water containment to avail dry product for facilitating the process for the final product.
[0023] The remaining process other than that described in those three steps are mandatory without any special requirements.
[0024] In the preparation of the totally biodegradable plastic master batch of the present invention, the starch must be refined due to that the starch generally available in the market is found with a comparatively larger grain size (20˜125 μm), which is bad for the binding between the starch and the polycyclic-lactone. The reduction of the grain size of the starch down to less than 1 μm increases the surface area of the starch available for the binding with the polycyclic-lactone, thus a better binding results between both materials.
[0025] In the preparation of the totally biodegradable plastic master batch of the present invention, the dehydration of the starch is very critical since the starch contains massive hydrophilic groups, and thus a comparatively higher water containment to compromise the molding results.
[0026] The primary advantage of totally biodegradable plastic master batch resulted from applying the preparation method of the present invention is that the finished product made from the plastic master batch of the present invention when disposed of can be one hundred and fast degraded by the enzyme secreted by microbes and fully converted into water and carbon dioxide to really realize the “white pollution” by being harmonized with the environment. Whereas the containment of start is comparatively higher in the making of the plastic master batch of the present invention and it is available at cheap price, the production cost per unit of the present invention is comparatively low (approximately at US$1.5), that is 3 to 4 folds of cost reduction when compared to that of the existing polycyclic-lactone plastic master batch. Furthermore, the starch is ever ready, and reclaimable resources in abundance to make the product of the present invention a very ideal substitute.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] In the following preferred embodiments of the present invention, all the compositions are given by weight with each part of 1 kg unless otherwise specified.
The First Preferred Embodiment
[0028] (1) 100 parts of starch, 200 parts of water, and 0.3 parts of anti-caking agent are mixed and blended into a thick solution; the solution is poured into the SK80-2A dispersing machine for 20˜30 minutes for the starch to be ground into such in a grain size of 1-10 g m with the refining temperature controller within the range of 40-60° C.; (2) The primary starch solution is put into HDZC-006-1 ultra filtration unit to be dehydrated; (3) The dehydrated starch is further mixed with 100 parts of glycerin or corn oil and blended again into a thick solution before being poured into the same dispersing machine for 40˜50 minutes to be ground into such that the starch is of a grain size less than <1 μm with the refining temperature controlled within the range of 50˜70° C.; (4) The secondary refined starch thick solution is then dehydrated in the ultra filtration unit for the water containment of the starch to drop below 0.5%; (5) the starch after two rounds of dehydration is then placed into the GKH1250-N centrifuge for a proper separation of oil from powder; (6) the starch availed from Step (5) and three parts of the coupling agent are poured into the GL500/1600 high-speed kneader for 20˜30 minutes for modification; (7) 30 parts of PGA, 12 parts of plasticizer, 5 parts of dispersing agent, 0.5 parts of oxidization promoter, and 3 parts of chemical degradation promoter are added in sequence into the kneader for 20˜30 minutes for the kneading; (8) the product availed from Step (7) is then placed into the dual-screw, dual-exhaust extrusion granulator with the extrusion temperature controlled in the range of 130-160° C. (Unit 1 at 130° C.: Unit 2, 135° C.; Unit 3, 140° C.; Unit 4, 145° C.; Unit 5, 150° C.; Unit 6, 155° C.; Unit 7, 160° C.; and the head, 155° C.); and the grains are then vacuum sealed for the preparation of the totally biodegradable engineering plastic product.
The Second Preferred Embodiment
[0029] (1) 100 parts of starch, 200 parts of water, and 0.2 parts of anti-caking agent are mixed and blended into a thick solution; the solution is poured into the SK80-2A dispersing machine for 20˜30 minutes for the starch to be ground into such in a grain size of 1-10 μm with the refining temperature controller within the range of 40-60° C.; (2) The primary starch solution is put into HDZC-006-1 ultra filtration unit to be dehydrated; (3) The dehydrated starch is further mixed with 100 parts of glycerin or corn oil and blended again into a thick solution before being poured into the same dispersing machine for 40˜50 minutes to be ground into such that the starch is of a grain size less than <1 μm with the refining temperature controlled within the range of 50˜70° C.; (4) The secondary refined starch thick solution is then dehydrated in the ultra filtration unit for the water containment of the starch to drop below 0.5%; (5) the starch after two rounds of dehydration is then placed into the GKH1250-N centrifuge for a proper separation of oil from powder; (6) the starch availed from Step (5) and four parts of the coupling agent are poured into the GL500/1600 high-speed kneader for 20˜30 minutes for modification; (7) 40 parts of PGA, 16 parts of plasticizer, 8 parts of dispersing agent, 0.2 parts of oxidization promoter, and 6 parts of chemical degradation promoter are added in sequence into the kneader for 20˜30 minutes for the kneading; (8) the product availed from Step (7) is then placed into the dual-screw, dual-exhaust extrusion granulator with the extrusion temperature controlled in the range of 130-160° C. (Unit 1 at 130° C.; Unit 2, 135° C.; Unit 3, 140° C.; Unit 4, 145° C.; Unit 5, 150° C.; Unit 6, 155° C.; Unit 7, 160° C.; and the head, 155° C.); and the grains are then vacuum sealed for the preparation of the totally biodegradable engineering plastic product.
The Third Preferred Embodiment
[0030] (1) 100 parts of starch, 200 parts of water, and 0.9 parts of anti-caking agent are mixed and blended into a thick solution; the solution is poured into the SK80-2A dispersing machine for 20˜30 minutes for the starch to be ground into such in a grain size of 1-10 μm with the refining temperature controller within the range of 40-60° C.; (2) The primary starch solution is put into HDZC-006-1 ultra filtration unit to be dehydrated; (3) The dehydrated starch is further mixed with 100 parts of glycerin or corn oil and blended again into a thick solution before being poured into the same dispersing machine for 40˜50 minutes to be ground into such that the starch is of a grain size less than <1 μm with the refining temperature controlled within the range of 50˜70° C.; (4) The secondary refined starch thick solution is then dehydrated in the ultra filtration unit for the water containment of the starch to drop below 0.5%; (5) the starch after two rounds of dehydration is then placed into the GKH1250-N centrifuge for a proper separation of oil from powder; (6) the starch availed from Step (5) and eight parts of the coupling agent are poured into the GL500/1600 high-speed kneader for 20˜30 minutes for modification; (7) 50 parts of polycyclic-lactone, 24 parts of plasticizer, 10 parts of dispersing agent, 1.0 parts of oxidization promoter, and 5 parts of chemical degradation promoter are added in sequence into the kneader for 20˜30 minutes for the kneading; (8) the product availed from Step (7) is then placed into the dual-screw, dual-exhaust extrusion granulator with the extrusion temperature controlled in the range of 80-120° C. (Unit 1 at 80° C.; Unit 2, 88° C.; Unit 3, 93° C.; Unit 4, 98° C.; Unit 5, 105° C.; Unit 6, 112° C.; Unit 7, 118° C.; Unit 8, 120° C.; and the head, 155° C.); and the grains are then vacuum sealed for the preparation of the totally biodegradable PVC film.
The Fourth Preferred Embodiment
[0031] (1) 100 parts of starch, 200 parts of water, and 1.0 parts of anti-caking agent are mixed and blended into a thick solution; the solution is poured into the SK80-2A dispersing machine for 20˜30 minutes for the starch to be ground into such in a grain size of 1-10 μm with the refining temperature controller within the range of 40-60° C.; (2) The primary starch solution is put into HDZC-006-1 ultra filtration unit to be dehydrated; (3) The dehydrated starch is further mixed with 100 parts of glycerin or corn oil and blended again into a thick solution before being poured into the same dispersing machine for 40˜50 minutes to be ground into such that the starch is of a grain size less than <1 μm with the refining temperature controlled within the range of 50˜70° C.; (4) The secondary refined starch thick solution is then dehydrated in the ultra filtration unit for the water containment of the starch to drop below 0.5%; (5) the starch after two rounds of dehydration is then placed into the GKH1250-N centrifuge for a proper separation of oil from powder; (6) the starch availed from Step (5) and twelve parts of the coupling agent are poured into the GL500/1600 high-speed kneader for 20˜30 minutes for modification; (7) 90 parts of β-hydrogen fatty acid esters, 35 parts of plasticizer, 20 parts of dispersing agent, 1.2 parts of oxidization promoter, and 18 parts of chemical degradation promoter are added in sequence into the kneader for 20˜30 minutes for the kneading; (8) the product availed from Step (7) is then placed into the dual-screw, dual-exhaust extrusion granulator with the extrusion temperature controlled in the range of 80-120° C. (Unit 1 at 80° C.; Unit 2, 88° C.; Unit 3, 93° C.; Unit 4, 98° C.; Unit 5, 105° C.; Unit 6, 112° C.; Unit 7, 118° C.; Unit 8, 120; and the head, 155° C.); and the grains are then vacuum sealed for the preparation of the totally biodegradable plastic film.
[0032] Test results of the degradation performance of the products are given in the table below.
[0000]
Preferred Embodiment
Degradation Efficiency
1
86.6
2
86.5
3
88.5
4
93.7
[0033] The degradation efficiency test is done as specified in ISO 14855 to determine the oxygen demanded biodegradation performance under controllable compost conditions and the structural breakdown performance for the analysis of the volume of CO2 generated. According to ISO14855, a totally degradable fibrin is used as a reference material in the test of the degradation of plastic material; and 45 days after the test, the biodegradation is considered as having totally been degraded when the degradation rate of the reference material is greater than 70%.
[0034] The degradation rate of the existing starch-based biodegradable plastic material is comparatively lower. National Trade Standard QB/T2461-1999: Degradable Polyethylene Film for Packaging Purpose provides that the degradation rate must be not less than 20%; and Technical Requirements of Products with Environmental Marking HJB112-2000: Packaging Products, not less than 15%. Therefore, the plastic master batch of the present invention is totally biodegradable as judged from the data given in the Table above. | The present invention presents a totally biodegradable plastic master batch and its preparation methodology. Three main steps in preparation of the totally biodegradable plastic master batch include step (1): Refining and dehydration of starch, followed by step (2): mixing of multiple ingredients, followed by step (3): molding of product derived from previous step (2). Four preferred embodiments are introduced, while degradation performance of each preferred embodiment is given in terms of its degradation efficiency value. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the priority of German Patent application No. P 43 17 673.9 filed May 27, 1993, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to a silencer arrangement for guns, including at least one silencer.
The configuration and function of gun silencers, particularly for small arms and hand guns, are disclosed, for example, in U.S. Pat. No. 3,713,362 and U.S. Pat. No. 4,576,083. This type of silencer is usually screwed to the muzzle of the gun tube or barrel.
The arrangement of known silencers on the muzzle of the tubes or barrels of large-caliber weapon systems (combat tanks, armored personnel carriers, anti-aircraft tanks or artillery systems) has not proven to be successful in practice. This is generally because, due to the large caliber of the weapons and the development of related noises, the silencers for such large caliber weapons must also be dimensioned suitably large and, as a consequence, are massive. However, the system characteristics of the weapon arrangement, particularly the stabilizing and alignment arrangements are influenced in a particularly unacceptable manner.
There was no shortage of tests for developing light-weight silencers for large-caliber weapons. However, besides being relatively costly, this type of silencer remains so massive that it cannot be employed in practice for the above-mentioned reasons. As far as the applicant knows, this is the reason why no silencers are currently used in large-caliber gun systems. However, especially during firing exercises on suitable firing sites, this increasingly results in problems which are due to the high emission of noise.
It is thus the object of the present invention to provide a silencer arrangement for large-caliber weapon systems in which the system characteristics of the gun are not negatively influenced by the heavy weight of the silencer and which makes possible an operation appropriate to the exercise, especially at firing sites.
SUMMARY OF THE INVENTION
The above object generally is attained according to one aspect of the present invention by a silencer arrangement for at least one gun which comprises: at least one silencer for enclosing a muzzle of a gun barrel; a silencer gun carriage on which the at least ones silencer is mounted, with the silencer gun carriage being mechanically decoupled from the gun with which the at least one silencer is to be used; and means, including adjustment members mounted on the silencer gun carriage, for adjusting the elevation and azimuth positions of the silencer such that when a gun is in a firing position relative to the silencer gun carriage, the gun bore axis and a central axis through the silencer are aligned.
According to a further aspect of the invention, the above object is achieved according to the present invention by a silencer arrangement for a gun including at least one silencer for enclosing a muzzle end of a gun barrel, and a silencer gun carriage which is mechanically decoupled from the gun, with the silencer gun carriage comprising: two mounting columns which are arranged vertically parallel to one another, and whose distance from one another is greater than the width of the gun mount which is to be arranged between the columns and whose gun is to be provided with the silencer, and with the mounting columns being mounted for pivotal or rotational movement about their respective vertical longitudinal axes; a respective extension arm mounted, at a predetermined height, on each mounting column for rotation about a common horizontal axis of rotation; at least one controllable drive member for rotating the two extension arms about the horizontal axis of rotation; a transverse member connected between respective ends of the two extension arms facing away from the mounting columns via hinge joints; and further hinge joints for connecting the at least one silencer to the transverse member between the two extension arms.
Further particularly advantageous modifications of the invention likewise are disclosed.
The invention is thus essentially based on the concept of fastening the respective silencer, not, as is the case with small-caliber weapons, on the gun tube or barrel itself, but instead to arrange it on a separate silencer gun carriage which is mechanically decoupled from the weapon tube, with the gun carrier preferably being constructed such that the silencer can be guided in synchronism with the movement of the weapon tube or barrel.
Further details and advantages of the invention are apparent from the specification below and are elucidated by the embodiments shown in the figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a first embodiment of the silencer arrangement according to the invention, including a combat tank in the firing position.
FIG. 2 is a perspective view of a second embodiment of a silencer arrangement according to the invention for an anti-aircraft tank having two guns, with the tank not yet having assumed its firing position.
FIG. 3 is a perspective view of the silencer arrangement illustrated in FIG. 2, with the anti-aircraft tank being in its firing position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, reference numeral 1 refers to a combat tank in its firing position. The tank 1 includes a rotatable turret 2 and a large-caliber gun 3. On the outside of the rotational range of the tank turret 2 is a silencer arrangement 4 which essentially comprises a silencer 5 and a gun carriage 6 supporting the silencer.
The silencer gun carriage 6 is provided with two base plates 7 and 8 on which respective parallel mounting columns 9 and 10 are arranged for rotation (pivoting) about their vertical respective longitudinal axes 11 and 12. The pivoting or rotational movements in this case are effected by adjustment members (drives) which are coupled to the mounting columns 9 and 10, with FIG. 1 merely showing one such drive denoted by 13 coupled to column 9 via appropriate gears. The horizontal distance of the two mounting columns 9 and 10 from one another is greater than the width of the tank 1, so that the latter can partly move into the gun carriage 6.
Attached to the upper end of each mounting column 9, 10 of the gun carriage 6, i.e., the end facing away from the respective base plate 7, 8, is a respective extension arm 14 or 15. Both extension arms 14, 15 are pivotal about a common horizontal rotational axis 16 which, in the embodiment shown in FIG. 1 with the tank 1 in the firing position, also corresponds to the trunnion axis of the gun 3. This association of the gun 3 and the silencer gun carriage 6 may be accomplished by a movement of the tank 1 or by adjustment of an adjustment device on the mounting columns 9, 10 of the gun carriage 6.
The pivoting movement of the extension arm 14, 15 about the horizontal axis 16 is effected by the respective adjustment members 17, 18, which may also be, for example, hydraulic, electric or even mechanical adjustment members.
The respective ends of the two extension arms 14, 15 facing away from the mounting columns 9, 10, are joined by hinges or bearings 22, 24 and 23, 25 to a transverse member 19. The transverse member 19 essentially comprises two parallel cross-ties 20, 21, to which the silencer 5 is also fastened by further bearings or hinge joints 27 and 26, respectfully. Transverse member 19 together with cross ties 20, 21 and hinge or bearing joints 22-27 form a parallel crank mechanism.
An evaluation unit 28 is provided in a control panel on base plate 7. The evaluation unit 28 is connected , on the one hand, with sensors 29 at the front of the silencer 5 and, on the other hand, with adjustment members or drives 13 and 17, 18. As a result, the center position of the gun muzzle of the weapon 3 is thus checked by the sensors 29, and the adjustment members 13, 17 and 18 are controlled and actuated by way of the evaluation unit 28 to provide the proper alignment between the bore axis of the barrel of the gun 3 and the central axis 30 through the silencer 5.
Moreover, the directional or aiming signals of the directional control or aiming devices for the gun 3, which are not shown in order to provide a clearer overview, may be scanned, for example, by means of a test plug connection to the gun control device, and used for the primary control of the silencer gun carriage 6. However, in order to increase operation safety or reliability, the position of the gun in relation to the silencer 5 is also tested or monitored via the above-mentioned sensors 29 and, if indicated, corrected.
During height or elevation adjustment of the gun 3, the adjustment members 17, 18 are actuated, either on the basis of the measured sensor signals or on the basis of the aiming signals that are present at the test plug connector, such that the bore axis of the weapon tube and the central axis 30 through the silencer 5 retain their identical position or alignment. The corresponding regulating or control signals in this case are obtained in a particularly simple manner, because both the gun 3 and the extension arms 14, 15 are pivoted about the same horizontal rotational axis 16.
If the gun 3 is aimed to the side, i.e., in azimuth, by rotating the turret 2, the corresponding sensor or aiming signals are again fed to the evaluation unit 28 and there they are processed into control signals for the adjustment members or drives 13. As a result, the parallel crank mechanism, which is defined essentially by the extension arms 14, 15 and the transverse member 19, ensures that in this case too, the bore axis and central axis 30 through the silencer 5 are aligned and retain their identical position after gun 3 completes its rotation.
In order to simultaneously adjust the height (elevation) and side movement (azimuth) of the silencer relative to the gun 3, the hinge or swivel joints 22-25 are configured as known multi-axis bearings, preferably, as a self-aligning pivot bearing.
A further embodiment is described below by way of FIGS. 2 and 3 in which the position of the weapon and the silencer gun carriage in the firing position not only have the same horizontal aiming axes but also the same rotational axes for side or azimuth adjustment. In this case, one prerequisite is that the trunnion axis of the gun or guns intersects the rotation axis of the turret at point 37.
FIG. 2 shows the situation prior to which a tank mount, denoted by 31, has assumed its firing position. The tank 31, which is an anti-aircraft tank, is provided with two guns 33, 34 on respective sides of the turret 32. The trunnion axis 35 for the guns 33, 34 in this case intersects the rotational axis 36 of the turret 2 at point 37.
The silencer arrangement denoted by 38 has in principal the same configuration as arrangement 4 described above in connection with FIG. 1. Particularly, the silencer gun carriage denoted by 39 comprises again two vertical mounting or bearing columns 42, 43, which are mounted for rotation about their respective longitudinal axes 40, 41, and at whose upper ends are two extension arms 45 and 46, respectively, which are arranged for rotation about the common horizontal axis 44. At their respective ends opposite the mounting columns 42, 43, the extension arms 45, 46 are again rotatably connected with a transverse member 49 comprising two generally parallel cross ties 47, 48, with the corresponding hinge or pivot joints being denoted by 50-53.
In contrast to FIG. 1, not one, but two silencers 54, 55, which are arranged parallel in relation to one another, are fastened to the silencer gun carrier 39 in order to dampen the noise formation of both guns 33,34. Both silencers 54, 55 are arranged on a silencer carrier 56 which itself is arranged centrally by way of hinge or swivel joints 57, 58 on the cross ties 47, 48 of the transverse member 49.
Further, in FIG. 2, 59 denotes a vertical axis which is located in the center between rotational axes 40 and 41.
FIG. 3 illustrates the case in which the anti-aircraft tank 31 is in the firing position and the two silencers 54, 55 thus enclose the muzzle ends of the guns 33, 34, respectively. In this case, the tank 31 was positioned in relation to the silencer arrangement 38 such that, with the height (elevation) and side (azimuth) positions of the guns 33, 34 set at 0°, the trunnion axis 35 of the weapon arrangement coincides with the horizontal rotational axis 44 of the carriage 39 and the vertical rotational axis 36 of the turret 32 is identical with the vertical axis 59 of the carriage 39. This association of guns 33, 34 and silencer gun carriage 39 may again occur by the movement of the tank 31 or by adjusting an adjustment device on the mounting columns 42, 43 of the silencer gun carriage 39. The actual control and/or alignment of the silencers 54, 55 in accordance with the position of the guns 33, 34 may, for example, as in the embodiment described with respect to FIG. 1, be accomplished with the help of sensors (not illustrated) or by scanning the aiming or directional signals of the gun aiming or directional control device in the tank.
The invention now being fully described, it will be apparent to one of ordinary skill in the art that any changes and modifications can be made thereto without departing from the spirit or scope of the invention as set forth herein. | A silencer arrangement for large-caliber guns (3;33,34) including at least one silencer (5;54,55). In order for the system characteristics of the gun (3;33,34) not to be negatively influenced by the heavy weight of the silencer (5;54,55), the silencer is not fastened (5;54,55), as in the case of small-caliber weapons, on the weapon tube or barrel itself, but instead, is arranged on a separate silencer gun carriage (6;39) which is mechanically decoupled from the gun (3;33,34), with the gun carriage (6;39) preferably being configured such that the silencers (5;54,55) may be moved in synchronism with the movement of the gun barrel. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a process for the production of mixtures of glyoxylic acid and aminomethylphosphonic acid (AMPA), where glycolic acid and oxygen are reacted in an aqueous solution, in the presence of AMPA and catalysts consisting of glycolate oxidase ((S)-2-hydroxy-acid oxidase, EC 1.1.3.15) and catalase (EC 1.11.1.6). The resulting mixtures of glyoxylic acid and AMPA produced in this manner are useful intermediates in the production of N-(phosphonomethyl)glycine, a broad-spectrum, post-emergent phytotoxicant and herbicide useful in controlling the growth of a wide variety of plants.
2. Description of the Related Art
Glycolate oxidase, an enzyme commonly found in leafy green plants and mammalian cells, catalyzes the oxidation of glycolic acid to glyoxylic acid, with the concomitant production of hydrogen peroxide:
HOCH.sub.2 CO.sub.2 H+O.sub.2 →OCHCO.sub.2 H+H.sub.2 O.sub.2
N. E. Tolbert et al., J. Biol. Chem., Vol. 181, 905-914 (1949) first reported an enzyme, extracted from tobacco leaves, which catalyzed the oxidation of glycolic acid to formic acid and CO 2 via the intermediate formation of glyoxylic acid. The addition of certain compounds, such as ethylenediamine, limited the further oxidation of the intermediate glyoxylic acid. The oxidations were carried out at a pH of about 8, typically using glycolic acid concentrations of about 3-40 mM (millimolar). The optimum pH for the glycolate oxidation was reported to be 8.9. Oxalic acid (100 mM) was reported to inhibit the catalytic action of the glycolate oxidase. Similarly, K. E. Richardson and N. E. Tolbert, J. Biol. Chem., Vol. 236, 1280-1284 (1961) showed that buffers containing tris(hydroxymethyl)aminomethane (TRIS) inhibited the formation of oxalic acid in the glycolate oxidase catalyzed oxidation of glycolic acid. C. O. Clagett, N. E. Tolbert and R. H. Burris, J. Biol. Chem., Vol. 178, 977-987 (1949) reported that the optimum pH for the glycolate oxidase catalyzed oxidation of glycolic acid with oxygen was about 7.8-8.6, and the optimum temperature was 35°-40° C.
I. Zelitch and S. Ochoa, J. Biol. Chem., Vol. 201, 707-718 (1953), and J. C. Robinson et al., J. Biol. Chem., Vol. 237, 2001-2009 (1962), reported that the formation of formic acid and CO 2 in the spinach glycolate oxidase-catalyzed oxidation of glycolic acid resulted from the nonenzymatic reaction of H 2 O 2 with glyoxylic acid. They observed that addition of catalase, an enzyme that catalyzes the decomposition of H 2 O 2 , greatly improved the yields of glyoxylic acid by suppressing the formation of formic acid and CO 2 . The addition of FMN (flavin mononucleotide) was also found to greatly increase the stability of the glycolate oxidase.
N. A. Frigerio and H. A. Harbury, J. Biol. Chem., Vol. 231, 135-157 (1958) have reported on the preparation and properties of glycolic acid oxidase isolated from spinach. The purified enzyme was found to be very unstable in solution; this instability was ascribed to the relatively weak binding of flavin mononucleotide (FMN) to the enzyme active site, and to the dissociation of enzymatically active tetramers and/or octamers of the enzyme to enzymatically-inactive monomers and dimers, which irreversibly aggregate and precipitate. The addition of FMN (flavin mononucleotide) to solutions of the enzyme greatly increased its stability, and high protein concentrations or high ionic strength maintained the enzyme as octamers or tetramers.
There are numerous other references to the oxidation of glycolic acid catalyzed by glycolic acid oxidase. The isolation of the enzyme (and an assay method) are described in the following references: I. Zelitch, Methods in Enzymology, Vol. 1, Academic Press, New York, 1955, p. 528-532 (from spinach and tobacco leaves), M. Nishimura et al., Arch. Biochem. Biophys., Vol. 222, 397-402 (1983) (from pumpkin cotyledons), H. Asker and D. Davies, Biochim. Biophys. Acta, Vol. 761, 103-108 (1983) (from rat liver), and M. J. Emes and K. H. Erismann, Int. J. Biochem., Vol. 16, 1373-1378 (1984) (from Lemna Minor L). The structure of the enzyme has also been reported: E. Cederlund et al., Eur. J. Biochem., Vol. 173, 523-530 (1988), and Y. Lindquist and C. Branden, J. Biol. Chem., Vol. 264, 3624-3628, (1989).
SUMMARY OF THE INVENTION
This invention relates to the preparation of mixtures of glyoxylic acid (or a salt thereof) and aminomethylphosphonic acid (AMPA) (or a salt thereof), by oxidizing glycolic acid with oxygen in aqueous solution and in the presence of AMPA and two enzyme catalysts, glycolate oxidase ((S)-2-hydroxy-acid oxidase, EC 1.1.3.15) and catalase (EC 1.11.1.6). Such mixtures of glyoxylic acid and AMPA are useful for the preparation of N-(phosphonomethyl)glycine, a post-emergent phytotoxicant and herbicide.
Although the enzyme-catalyzed reaction of glycolic acid with oxygen is well known, high selectivies to glyoxylic acid have not been previously obtained, and there are no previous reports of performing the enzymatic oxidation of glycolic acid in the presence of aminomethylphosphonic acid (AMPA). A previous application, U.S. Ser. No. 07/422,011, filed Oct. 16, 1989, now abandoned, "Production of Glyoxylic Acid from Glycolic Acid", described a process for the enzymatic conversion of glycolic acid to glyoxylic acid in the presence of oxygen, an amine buffer, and the soluble enzymes glycolate oxidase and catalase. This process demonstrated the unexpected synergistic effect of using both catalase (to destroy byproduct hydrogen peroxide) and an amine buffer capable of forming a chemical adduct with the glyoxylic acid produced (limiting its further oxidation). Neither the separate addition of catalase nor an amine buffer was found to produce the high selectivity observed when both were present, and the almost quantitative yields of glyoxylic acid obtained were more than expected from a simple additive effect of using catalase or amine buffer alone.
Improvements in the yields of glyoxylate produced by the formation of an oxidation-resistant complex of glyoxylate and an amine buffer (via the formation of an N-substituted hemiaminal and/or imine) were found to be dependent on the pKa of the protonated amine buffer. The result of oxidizing aqueous solutions of glycolic acid (0.25M) in the presence of an amine buffer (0.33 M, pH 8.3), glycolate oxidase (0.5 IU/mL), catalase (1,400 IU/mL), and FMN (0.01 mM) at 30° C., and under 1 atm of oxygen for 24 h, are listed in the table below, along with reactions performed using two buffers not expected to complex with glyoxylate (phosphate and bicine):
______________________________________ % oxy- % gly- % gly- %Buffer (pKa) late oxylate colate formate______________________________________ethylenediamine (6.85, 9.93) 6.8 85.5 0.8 2.4TRIS (8.08) 1.1 81.0 2.8 12.0methylamine (10.62) 1.0 53.9 39.8 5.1ethanolamine (9.50) 1.8 69.6 4.81 24.5ammonium chloride (9.24) 1.1 39.9 37.7 18.9isopropanolamine (9.43) 2.0 60.0 4.8 37.4bicine (8.30) 1.0 24.9 25.6 43.8phosphate (2.15, 7.10, 12.3) 0.7 24.5 52.4 21.2______________________________________
Of the amine buffers examined, amines with a pKa approximately equal to or lower than the pH of the reaction mixture (i.e., ethylenediamine and tris) produced much higher yields of glyoxylate (and low formate and oxalate production) than amine buffers whose pKa's were higher than the pH at which the reaction was performed. These results are consistent with the expectation that an unprotonated amine may be necessary to form an oxidation-resistant N-substituted hemiaminal and/or imine complex with glyoxylate; an amine buffer whose pKa is much higher than the pH of the reaction mixture would be present predominantly as the protonated ammonium ion in the reaction mixture, and therefore be less likely to form such complexes with glyoxylate.
The pKa of the protonated amine of aminomethylphosphonic acid (AMPA) is reported to be 10.8 (Lange's Handbook of Chemistry, J. A. Dean, Ed., McGraw-Hill, New York, 1979, 12th Edition), therefore it was unexpected that the addition of AMPA to enzymatic oxidations of glycolic acid within the pH range of 7 to 9 would result in high yields of glyoxylic acid. The accompanying Examples illustrate that yields of glyoxylic acid as high as 92% have been attained using this amine. In addition to the unexpected high yields of glyoxylic acid obtained, the use of AMPA also results in an improvement in recovery of glycolate oxidase and catalase activity when compared to reactions run in the absence of added AMPA (Example 13). Recovery of catalyst for recycle is usually required in processes utilizing enzyme catalysts, where catalyst cost makes a significant contribution to the total cost of manufacture.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The catalytic oxidation of glycolic acid or a suitable salt thereof is conveniently carried out by contacting the glycolic acid with a source of molecular oxygen in the presence of an enzyme catalyst which catalyzes the reaction of glycolic acid with O 2 to form glyoxylic acid. One such catalyst is the enzyme glycolate oxidase (EC 1.1.3.15), also known as glycolic acid oxidase. Glycolate oxidase may be isolated from numerous sources well-known to the art. The glycolate oxidase used in the reaction should be present in an effective concentration, usually a concentration of about 0.01 to about 1000 IU/mL, preferably about 0.1 to about 4 IU/mL. An IU (International Unit) is defined as the amount of enzyme that will catalyze the transformation of one micromole of substrate per minute. A procedure for the assay of this enzyme is found in I. Zelitch and S. Ochoa, J. Biol. Chem., Vol. 201, 707-718 (1953). This method is also used to assay the activity of recovered or recycled glycolate oxidase.
Optimal results in the use of glycolate oxidase as a catalyst for the oxidative conversion of glycolic acid to glyoxylic acid are obtained by incorporating into the reaction solution a catalyst for the decomposition of hydrogen peroxide. One such peroxide-destroying catalyst which is effective in combination with glycolate oxidase is the enzyme catalase (E.C. 1.11.1.6). Catalase catalyzes the decomposition of hydrogen peroxide to water and oxygen, and it is believed to improve yields of glyoxylic acid in the present process by accelerating the decomposition of the hydrogen peroxide produced along with glyoxylic acid in the glycolate oxidase-catalyzed reaction of glycolic acid with O 2 . The concentration of catalase should be 50 to 50,000 IU/mL, preferably 500 to 15,000 IU/mL. It is preferred that the catalase and glycolate oxidase concentrations be adjusted within the above ranges so that the ratio (measured in IU for each enzyme) of catalase to glycolate oxidase is at least about 250:1.
Another optional but often beneficial ingredient in the reaction solution is flavin mononucleotide (hereinafter referred to as FMN) which is generally used at a concentration of 0.0 to about 2.0 mM, preferably about 0.01 to about 0.2 mM. It is believed the FMN increases the productivity of the glycolate oxidase, by which is meant the amount of glycolic acid converted to glyoxylic acid per unit enzyme increases. It is to be understood that the concentration of added FMN is in addition to any FMN present with the enzyme, because FMN is often also added to the enzyme during the preparation of the enzyme. The structure of FMN and a method for its analysis is found in K. Yagai, Methods of Biochemical Analysis, Vol. X, Interscience Publishers, New York, 1962, p. 319-355, which is hereby included by reference.
Glycolic acid (2-hydroxyacetic acid) is available commercially. In the present reaction its initial concentration is in the range of 0.10M to 2.0M, preferably between 0.25M and 1.0M. It can be used as such or as a compatible salt thereof, that is, a salt that is water-soluble and whose cation does not interfere with the desired conversion of glycolic acid to glyoxylic acid, or the subsequent reaction of the glyoxylic acid product with the aminomethylphosphonic acid to form N-(phosphonomethyl)glycine. Suitable and compatible salt-forming cationic groups are readily determined by trial. Representative of such salts are the alkali metal, alkaline earth metal, ammonium, substituted ammonium, phosphonium, and substituted phosphonium salts.
The conversion of glycolic acid to glyoxylic acid is conveniently and preferably conducted in aqueous media. Aminomethylphosphonic acid (AMPA), or a suitable salt thereof, is added to produce a molar ratio of AMPA/glycolic acid (starting amount) in the range of from 0.01/1.0 to 3.0/1.0, preferably from 0.25/1.0 to 1.05/1.0. After combining AMPA and glycolic acid in an aqueous solution, the pH of the resulting mixture is adjusted to a value between 6 and 10, preferably between 7.0 and 8.5. Within this pH range, the exact value may be adjusted to obtain the desired pH by adding any compatible, non-interfering base, including alkali metal hydroxides, carbonates, bicarbonates and phosphates. The pH of the reaction mixture decreases slightly as the reaction proceeds, so it is often useful to start the reaction near the high end of the maximum enzyme activity pH range, about 9.0-8.5, and allow it to drop during the reaction. The pH can optionally be maintained by the separate addition of a non-interfering inorganic or organic buffer, since enzyme activity varies with pH.
It is understood that glycolic and glyoxylic acids are highly dissociated in water, and at pH of between 7 and 10 are largely if not substantially entirely present as glycolate and glyoxylate ions. It will also be appreciated by those skilled in the art that glyoxylic acid (and its conjugate base, the glyoxylate anion) may also be present as the hydrate, e.g. (HO) 2 CHCOOH and/or as the hemiacetal, HOOCCH(OH)OCH(OH)COOH, which compositions and their anionic counterparts are equivalent to glyoxylic acid and its anion for the present purpose of being suitable reactants for N-(phosphonomethyl)glycine formation.
Oxygen (O 2 ), the oxidant for the conversion of the glycolic acid to glyoxylic acid, may be added as a gas to the reaction by agitation of the liquid at the gas-liquid interface or through a membrane permeable to oxygen. It is believed that under most conditions, the reaction rate is at least partially controlled by the rate at which oxygen can be dissolved into the aqueous medium. Thus, although oxygen can be added to the reaction as air, it is preferred to use a relatively pure form of oxygen, and even use elevated pressures. Although no upper limit of oxygen pressure is known, oxygen pressures up to 50 atmospheres may be used, and an upper limit of 15 atmospheres is preferred. Agitation is important to maintaining a high oxygen dissolution (hence reaction) rate. Any convenient form of agitation is useful, such as stirring. On the other hand, as is well known to those skilled in the enzyme art, high shear agitation or agitation that produces foam may decrease the activity of the enzyme(s), and should be avoided.
The reaction temperature is an important variable, in that it affects reaction rate and the stability of the enzymes. A reaction temperature of 0° C. to 40° C. may be used, but the preferred reaction temperature range is from 5° C. to 15° C. Operating in the preferred temperature range maximizes recovered enzyme activity at the end of the reaction. The temperature should not be so low that the aqueous solution starts to freeze. Temperature can be controlled by oridinary methods, such as, but not limited to, by using a jacketed reaction vessel and passing liquid of the appropriate temperature through the jacket. The reaction vessel may be constructed of any material that is inert to the reaction ingredients.
Upon completion of the reaction, the enzymes may be removed by filtration or centrifugation and reused. Alternatively, they can be denatured and precipitated by heating, e.g. to 70° C. for 5 minutes, and/or can be allowed to remain in the reaction mixture if their presence in the subsequent steps of converting the glyoxylic acid-aminomethylphosphonic acid mixture to N-(phosphonomethyl)glycine, and of recovering N-(phosphonomethyl)glycine from the reaction mixture, is not objectionable.
Following the cessation of contacting the reaction solution with O 2 , and preferably following the removal of the enzyme glycolate oxidase and the enzyme catalase when present, flavin mononucleotide (FMN) may optionally be removed by contacting the solution with decolorizing carbon. The solution containing glyoxylic acid and aminomethylphosphonic acid (which are believed to be in equilibrium with the corresponding imine), is treated in accordance with any of the processes known to the art for producing N-(phosphonomethyl)glycine.
Catalytic hydrogenation is a preferred method for preparing N-(phosphonomethyl)glycine from a mixture of glyoxylic acid and aminomethylphosphonic acid. Hydrogenation catalysts suitable for this purpose include (but are not limited to) the various platinum metals, such as iridium, osmium, rhodium, ruthenium, platinum, and palladium; also various other transition metals such as cobalt, copper, nickel and zinc. The catalyst may be unsupported, for example as Raney nickel or platinum oxide; or it may be supported, for example as platinum on carbon, palladium on alumina, or nickel on kieselguhr. Palladium on carbon, nickel on kieselguhr and Raney nickel are preferred. The hydrogenation can be performed at a pH of from 4 to 11, preferably from 5 to 10. The hydrogenation temperature and pressure can vary widely. The temperature is generally in the range of 0° C. to 150° C., preferably from 20° C. to 90° C., while the H 2 pressure is generally in the range of from about atmospheric to about 100 atmospheres, preferably from 1 to 10 atmospheres. N-(Phosphonomethyl)glycine, useful as a post-emergent herbicide, may be recovered from the reduced solution, whatever the reducing method employed, by any of the recovery methods known to the art.
In the following examples, which serve to further illustrate the invention, the yields of glyoxylate, formate and oxalate, and the recovered yield of glycolate, are percentages based on the total amount of glycolic acid present at the beginning of the reaction. Analyses of reaction mixtures were performed using high pressure liquid chromatography. Organic acid analyses were performed using a Bio-Rad HPX-87H column, and AMPA and N-(phosphonomethyl)glycine were analyzed using a Bio-Rad Aminex glyphosate analysis column.
EXAMPLE 1
Into a 3 oz. Fischer-Porter glass aerosol reaction vessel was placed a magnetic stirring bar and 10 mL of an aqueous solution containing glycolic acid (0.25M), aminomethylphosphonic acid (AMPA, 0.263M), FMN (0.01 mM), propionic acid (HPLC internal standard, 0.125M), glycolate oxidase (from spinach, 1.0 IU/mL), and catalase (from Aspergillus niger, 1,400 IU/mL) at pH 8.5. The reaction vessel was sealed and the reaction mixture was cooled to 15° C., then the vessel was flushed with oxygen by pressurizing to 70 psig and venting to atmospheric pressure five times with stirring. The vessel was then pressurized to 70 psig of oxygen and the mixture stirred at 15° C. Aliquots (0.10 mL) were removed by syringe through a sampling port (without loss of pressure in the vessel) at regular intervals for analysis by HPLC to monitor the progress of the reaction. After 5 h, the HPLC yields of glyoxylate, formate, and oxalate were 70.4%, 19.6%, and 2.2%, respectively, and 5.3% glycolate remained. The remaining activity of glycolate oxidase and catalase were 27% and 100%, respectively, of their initial values.
Example 2 (Comparative)
The reaction in Example 1 was repeated, using 0.33 M K 2 HPO 4 in place of 0.265M AMPA. After 5 h, the HPLC yields of glyoxylate, formate, and oxalate were 34.1%, 11.1%, and 0.2%, respectively, and 58.7% glycolate remained. After 23 h, the HPLC yields of glyoxylate, formate, and oxalate were 39.4%, 44.7%, and 15.34%, respectively, and no glycolate remained. The remaining activity of glycolate oxidase and catalase were 85% and 87%, respectively, of their initial values.
Example 3 (Comparative)
The reaction in Example 1 was repeated, using 0.263M bicine buffer in place of 0.265M AMPA. After 5 h, the HPLC yields of glyoxylate, formate, and oxalate were 42.5%, 49.6%, and 10.1%, respectively, and 0.2% glycolate remained. The remaining activity of glycolate oxidase and catalase were 47% and 100%, respectively, of their initial values.
EXAMPLE 4
The reaction in Example 1 was repeated using 5,600 IU/mL catalase from Aspergillus niger. After 6 h, the HPLC yields of glyoxylate, formate, and oxalate were 85.5%, 7.6%, and 3.3%, respectively, and 2.5% glycolate remained. The remaining activity of glycolate oxidase and catalase were 36% and 100%, respectively, of their initial values.
EXAMPLE 5
The reaction in Example 1 was repeated using 14,000 IU/mL catalase from Aspergillus niger. After 6 h, the HPLC yields of glyoxylate, formate, and oxalate were 88.0%, 3.3%, and 3.0%, respectively, and 3.4% glycolate remained. The remaining activity of glycolate oxidase and catalase were 28% and 96%, respectively, of their initial values.
EXAMPLE 6
The reaction in Example 1 was repeated using 56,000 IU/mL catalase from Aspergillus niger. After 6 h, the HPLC yields of glyoxylate, formate, and oxalate were 84.0%, 0.4%, and 2.5%, respectively, and 8.4% glycolate remained. The remaining activity of glycolate oxidase and catalase were 16% and 76%, respectively, of their initial values.
EXAMPLE 7
Into a 3 oz. Fischer-Porter glass aerosol reaction vessel was placed a magnetic stirring bar and 10 mL of an aqueous solution containing glycolic acid (0.25M), aminomethylphosphonic acid (AMPA, 0.20M), FMN (0.01 mM), butyric acid (HPLC internal standard, 0.10M), glycolate oxidase (from spinach, 1.0 IU/mL), and catalase (from Aspergillus niger, 14,000 IU/mL) at pH 8.5. The reaction vessel was sealed and the reaction mixture was cooled to 5° C. (instead of 15° C. as described in previous examples), then the vessel was flushed with oxygen by pressurizing to 70 psig and venting to atmospheric pressure five times with stirring. The vessel was then pressurized to 70 psig of oxygen and the mixture stirred at 5° C. Aliquots (0.10 mL) were removed by syringe through a sampling port (without loss of pressure in the vessel) at regular intervals for analysis by HPLC to monitor the progress of the reaction. After 6 h, the HPLC yields of glyoxylate, formate, and oxalate were 92.3%, 4.36%, and 5.5%, respectively, and no glycolate remained. The remaining activity of glycolate oxidase and catalase were 87% and 88%, respectively, of their initial values.
EXAMPLE 8
The reaction in Example 7 was repeated, using an aqueous solution containing glycolic acid (0.50M), aminomethylphosphonic acid (AMPA, 0.40M), FMN (0.01 mM), butyric acid (HPLC internal standard, 0.10M), glycolate oxidase (from spinach, 1.0 IU/mL), and catalase (from Aspergillus niger, 14,000 IU/mL) at pH 8.5. After 17.5 h, the HPLC yields of glyoxylate, formate, and oxalate were 91.0%, 2.9%, and 2.9%, respectively, and 4.1% glycolate remained. The remaining activity of glycolate oxidase and catalase were 63% and 91%, respectively, of their initial values.
EXAMPLE 9
The reaction in Example 7 was repeated, using an aqueous solution containing glycolic acid (0.75M), aminomethylphosphonic acid (AMPA, 0.60M), FMN (0.01 mM), butyric acid (HPLC internal standard, 0.10M), glycolate oxidase (from spinach, 2.0 IU/mL), and catalase (from Aspergillus niger, 14,000 IU/mL) at pH 8.5.. After 40 h, the HPLC yields of glyoxylate, formate, and oxalate were 83.2%, 2.3%, and 7.5%, respectively, and no glycolate remained. The remaining activity of glycolate oxidase and catalase were 65% and 86%, respectively, of their initial values.
EXAMPLE 10
The reaction in Example 7 was repeated, using an aqueous solution containing glycolic acid (1.0M), aminomethylphosphonic acid (AMPA, 0.80M), FMN (0.01 mM), butyric acid (HPLC internal standard, 0.01M), glycolate oxidase (from spinach, 2.0 IU/mL), and catalase (from Aspergillus niger, 14,000 IU/mL) at pH 8.5.. After 66 h, the HPLC yields of glyoxylate, formate, and oxalate were 78.9%, 2.2%, and 12.1%, respectively, and 2.0% glycolate remained. The remaining activity of glycolate oxidase and catalase were 64% and 87%, respectively, of their initial values.
EXAMPLE 11
The reaction in Example 8 was repeated at pH 8.0. After 17.5 h, the HPLC yields of glyoxylate, formate, and oxalate were 87.0%, 2.2%, and 1.9%, respectively, and 8.5% glycolate remained. The remaining activity of glycolate oxidase and catalase were 44% and 97%, respectively, of their initial values.
EXAMPLE 12
The reaction in Example 8 was repeated at pH 7. After 17.5 h, the HPLC yields of glyoxylate, formate, and oxalate were 88.0%, 1.4%, and 1.9%, respectively, and 8.2% glycolate remained. The remaining activity of glycolate oxidase and catalase were 44% and 93%, respectively, of their initial values.
EXAMPLE 13
Into a 3 oz. Fischer-Porter glass aerosol reaction vessel was placed a magnetic stirring bar and 10 mL of an aqueous solution containing glycolic acid (0.50M), FMN (0.01 mM), isobutyric acid (HPLC internal standard, 0.10M), glycolate oxidase (from spinach, 1.0 IU/mL), and catalase (from Aspergillus niger, 14,000 IU/mL) at pH 8.5. The reaction vessel was sealed and the reaction mixture was cooled to 5° C., then the vessel was flushed with oxygen by pressurizing to 70 psig and venting to atmospheric pressure five times with stirring. The vessel was then pressurized to 70 psig of oxygen and the mixture stirred at 5° C. Aliquots (0.10 mL) were removed by syringe through a sampling port (without loss of pressure in the vessel) at regular intervals for analysis by HPLC to monitor the progress of the reaction. After 21 h, the HPLC yields of glyoxylate, formate, and oxalate were 81.7%, 1.2%, and 2.2%, respectively, and 7.5% glycolate remained. The remaining activity of glycolate oxidase and catalase were 19% and 77%, respectively, of their initial values. This reaction was then repeated with 0.50M glycolic acid and 0.25M, 0.375M, 0.40M, 0.50M, or 0.625M aminomethylphosphonic acid (AMPA) present, and the yields of reaction products and enzyme recoveries for these reactions are listed below:
______________________________________ glyoxy- for- oxa- glyco- glycolate cata-[AMPA] late mate late late oxidase lase(M) (%) (%) (%) (%) (%) (%)______________________________________0.00 81.7 1.2 2.2 7.5 19 770.25 79.4 2.1 3.3 2.5 48 790.375 78.3 2.3 3.6 1.7 57 950.40 91.0 2.9 2.9 4.1 63 910.50 85.2 1.5 3.3 5.5 49 930.625 79.6 1.7 1.8 14.0 42 94______________________________________
EXAMPLE 14
The mixture of glyoxylic acid (0.46M) and AMPA (0.40M) from Example 8 was filtered using an Amicon Centriprep 10 concentrator (10,000 molecular weight cutoff) to remove the soluble enzymes, then the filtrate was placed in a 3-oz. Fischer-Porter bottle equipped with a magnetic stirrer bar. To the bottle was then added 0.100 g of 10% Pd/C and the bottle sealed, flushed with nitrogen gas, then pressurized to 50 psi and stirred at 25° C. After 17 h, the concentration of N-(phosphonomethyl)glycine (determined by HPLC) was 0.29M (72% yield based on AMPA). | The invention provides a process for producing mixtures of glyoxylic acid and aminomethylphosphonic acid. The process comprises reacting glycolic acid and oxygen in an aqueous solution in the presence of aminomethylphosphonic acid catalyst consisting of glycolate oxidase and catalase. The resulting mixtures are useful intermediates in the production of N-(phosphonomethyl)glycine. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation of U.S. Ser. No. 08/901,890, filed Jul. 29, 1997, now U.S. Pat No. 6,096,037 which application is incorporated herein by reference.
BACKGROUND OF THE INVENTION
This invention relates to medical instruments, and more particularly to electrosurgical devices, and methods of manipulating tissue as, for example, by cutting the tissue.
DESCRIPTION OF THE RELATED ART
High-frequency alternating current was used to cut and coagulate human tissue as early as 1911. Current generators and electrode tipped instruments then progressed such that electrosurgical instruments and current generators are available in a multitude of configurations for both open procedures and endoscopic procedures, with microprocessor-controlled currents typically on the order of 500 KHz.
Radiofrequency (RF) catheter ablation of brain lesions began in the 1960s, and RF ablation of heart tissue to control supraventricular tachyarrhythmias began in the 1980s. Thus, electrical energy, including but not limited to RF energy, is a known tool for a variety of effects on human tissue, including cutting, coagulating, and ablative necrosis, with and as a part of electrically conductive forceps. Bipolar and monopolar currents are both used with electrosurgical forceps. With monopolar current, a grounding pad is placed under the patient. A recent example of an electrically energized electrosurgical device is disclosed in U.S. Pat. No. 5,403,312 issued on Apr. 4, 1995 to Yates et al., and the disclosure is incorporated by reference.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an electrosurgery tissue sealing medical device which may and also may not be a forceps. Another object of the present invention is to provide an electrosurgery tissue sealing device such as a forceps that seals tissue by a unique flow of an electrolytic fluid or solution to the manipulating portions of the device in combination with energization of the solution with electrical energy. The effect of the solution and energy may be enhanced with pressure. The solution is brought into contact with and infuses the tissue. The solution may include saline as well as other non-toxic and toxic electrolytic solutions, and may be energized with RF electrical energy. The body of the device itself may or not be energized.
The solution provides at least in part the beneficial functions and effects of the instrument. As preferred, pressure on the tissue is applied, and most preferably the effect of pressure is optimized, as by applying pressure across the tissue to be effected that is substantially uniform.
Another object of the invention is to provide an electrosurgery medical device as described, and methods of sealing tissue, in which tissues are sealed against flow of fluids including air. With the invention, for example, lung tissue is aerostatically and hemostatically sealed, with the tissue adjacent the sealed tissue retaining blood and air.
Another object of the invention is to provide an electrosurgery medical device that may take the form of open surgery forceps of a variety of specific forms, or endoscopic forceps, also of a variety of forms.
A further object of the invention is to provide an electrosurgery medical device as described, in which the electrolytic solution by which the instrument functions is infused from the device onto and/or into the tissue along the operative portions of the device. With and without applied pressure, the solution coagulates and additionally seals tissue, as a result of being energized by RF energy, and also envelopes the operative portions of the device in solution all during manipulation of tissue, substantially completely preventing adherence between the instrument and tissue, substantially without flushing action.
In a principal aspect, then, the invention takes the form of an enhanced solution-assisted electrosurgery medical device comprising, in combination, co-operating device jaws including jaw portions for manipulating tissue, and a plurality of solution infusion openings defined and spaced along each of the jaw portions, for receiving solution and infusing solution onto and into the tissue along said jaw portions. While the device is contemplated with and without grooves, as preferred, the device further comprises at least one, and most preferably, many, longitudinal grooves along at least one and most preferably, both, of the jaw portions. Also most preferably, the solution infusion openings are located on the inside faces of the jaw portions, adjacent to and most preferably in the groove or grooves. The solution exiting the openings separates substantially all the operative surfaces of the device from tissue, substantially completely preventing adherence between the operative surfaces and tissue. The solution also aids in coagulation.
Coagulation aside, the invention causes hemostasis, aerostasis, and more
generally, “omnistasis” of substantially any and all liquids and gases found in tissue being treated, such as lymphatic fluids and methane, as well as blood and air. These broader effects are understood to result from such actions as shrinkage of vascalature with and without coagulation, and without desiccation and carbonization.
Also as preferred, the operative portions of the device may take the form of a circular, semicircular or other regular and irregular geometric shape, to contain and/or isolate tissue to be affected and perhaps resected. As an example, with an enclosed geometric shape such as a circle, tissue surrounding lesions and/or tumors of the lung may be aerostatically and hemostatically sealed, resulting in an isolation of the lesions and/or tumors for resection. Lung function is retained. For adaption to unique tissue geometries, the operative portions of the device may be malleable, to be manipulated to substantially any needed contour. For procedures including resection, the device may include an advanceable and retractable blade, or additional functional structures and features.
These and other objects, advantages and features of the invention will become more apparent upon a reading of the detailed description of preferred embodiments of the invention, which follows, and reference to the drawing which accompanies this description.
BRIEF DESCRIPTION OF THE DRAWING
The accompanying drawing includes a variety of figures. Like numbers refer to like parts throughout the drawing. In the drawing:
FIG. 1 is a schematic diagram of the key elements of an electrical circuit according to the invention;
FIG. 2 is a perspective view of an endoscopic forceps according to the invention;
FIG. 3 is a detail view of a portion of the forceps of FIG. 2; and
FIG. 4 is a perspective view of a modification of the embodiment of FIG. 2;
to FIG. 5 is a second modification, of the embodiment of FIG. 4, shown partially broken away;
FIG. 6 is a perspective view of an open surgery forceps according to the invention;
FIG. 7 is a detail view of a portion of the forceps of FIG. 6, partially broken away,
FIG. 8 is a schematic view of preferred saline supply equipment for the invention;
FIG. 9 is a perspective view of a portion of the jaws of an alternative device;
FIG. 10 is a perspective view similar to FIG. 9 of another alternative device;
FIG. 11 is a cross-sectional view along line 11 - 11 of FIG. 9; and
FIG. 12 is a perspective view of yet another alternative device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Electrosurgery uses electrical energy to heat tissue and cause a variety of effects such as cutting, coagulation and ablative necrosis. The heat arises as the energy dissipates in the resistance of the tissue. The effect is dependent on both temperature and time. Lower temperatures for longer times often yield the same effect as higher temperatures for shorter times. Normal body temperature is approximately 37° C. No significant long-term effect is caused by temperatures in the range of 37° C. to 40° C. In the range of 41° C. to 44° C., cell damage is reversible for exposure times less than several hours. In the range of 45° C. to 49° C., cell damage becomes irreversible at increasingly short intervals. The following table states expected effects at higher temperatures:
Temperature (° C.)
Effect
50-69
Irreversible cell damage - ablation
necrosis.
70
Threshold temperature for shrinkage
of tissue. (Some collagen hydrogen
bonds break at 60-68; those with
cross-linkages break at 75-80.)
70-99
Range of coagulation.
Hemostasis due to shrinkage of blood
vessels.
100
Water boils.
100-200
Desiccation as fluid is vaporized.
Dependent on the length of time
during which heat is applied,
carbonization may occur, and at higher
temperatures, occurs quickly.
This table is not intended as a statement of scientifically precise ranges above and below which no similar effects will be found, and instead, is intended as a statement of generally accepted values which provide approximations of the ranges of the stated effects. Limitation of the appended claims in accordance with this and the further details of this description is intended to the extent such details are incorporated in the claims, and not otherwise.
As a consequence of the foregoing effects, preferred “soft” coagulation occurs at temperatures slightly above 70° C. Heat denatures and shrinks tissues and blood vessels, thereby leading, as desired, to control of bleeding. Cells are generally not ruptured. “Soft” coagulation is generally assured with voltages below 200 peak Volts. Sparks are avoided. “Forced” coagulation can be accomplished with bursts of electrical energy. Electric arcs are generated. Deeper coagulation is achieved, at the cost of some carbonization and an occasional cutting effect. Spray coagulation is also possible. Tissue cutting occurs by desiccation, when the concentration of electrical energy, also referred to here as energy density, is acute, and the temperature of tissue is raised above 100° C.
For both coagulation and cutting by electrical energy, a sine wave waveform is employed, with a frequency of about 500 kHz. For cutting, increasing voltage to as much as 600 peak Volts leads to higher spark intensity which results in deeper cuts.
Frequencies above 300,000 Hz avoid stimulating nerve and muscle cells, and generally assure that the effect on tissue is substantially purely thermal.
In contrast with the RF energy tissue-cutting electrosurgery tools of the past, significant purposes of the present invention are to provide a mechanism of avoiding desiccation of tissue at the electrode/tissue interface and to achieve sealing of tissues. By “sealing,” the effects of hemostasis, or arresting of bleeding; “aerostasis,” or arresting of the passage of air; and closure of tissues such as blood vessels against larger-scale passage of blood, among other effects, are intended. More specifically, the effect of sealing at the cellular level is a primary focus, as is sealing at the vascular level.
Referring to FIG. 1, key elements of a preferred electrical circuit according to the invention include an electrosurgical unit 10 , a switch 12 , and electrodes 14 , 16 . An effect is created on tissue 18 of a body 20 . One electrode such as electrode 14 acts as a positive or active electrode, while the other such as electrode 16 acts as a negative or return electrode. Current flows directly from one electrode to the other primarily through only the tissue, as shown by arrows 22 , 24 , 26 , 28 , 29 . No pad is needed under the patient. This is a bipolar configuration.
Referring to FIG. 2, a forceps 30 according to the invention is an endoscopic forceps, and includes manual handles 32 , 34 , an elongated shaft 36 , and jaws 38 , 40 . The handles 32 , 34 pivot together and apart and through a suitable mechanism (not shown; present in the incorporated prior art) control the jaws 38 , 40 to also pivot together and apart about a pivot connection 42 . Referring to FIG. 3, each jaw 38 , 40 is formed in two parts, hinged together. The jaw 38 includes a link portion 44 connected directly to the forceps shaft 36 , and the jaw 40 includes a link portion 46 also connected directly to the forceps shaft 36 . A jaw portion 48 hingedly fastened to the jaw link portion 44 completes the jaw 38 ; a jaw portion 50 hingedly fastened to the jaw link portion 46 completes the jaw 40 .
As stated in the background of the invention, a wide variety of alternatives to the structure described and shown in FIG. 2 are possible. Prominent examples from those incorporated include the structures of U.S. Pat. No. 5,403,312 (Yates et al.) issued Apr. 4, 1995; U.S. Pat. No. 5,395,312 (Desai) issued Mar. 7, 1995; and U.S. Pat. No. 5,318,589 (Lichtman et al.) issued Jun. 7, 1994.
Still referring to FIG. 3, a solution supply tube 52 supplies electrolytic solution to an electrode strip 47 along the jaw portion 48 , as will be described. A solution supply tube 54 supplies electrolytic solution to a similar strip 49 along the jaw portion 50 . A wire 56 electrically connects to the solution supply tube 52 ; a wire 58 electrically connects to the solution supply tube 54 . All the supplies 52 , 54 , 56 , 58 , both solution and electrical, extend from the proximal or manual handle end of the shaft 36 , and connect to solution and electrical sources.
Referring to FIG. 4, and in a second form of a jaw, designated 140 , a jaw portion 150 similar to jaw portion 50 in FIG. 3, includes a longitudinal dimension in the direction of arrow 160 . A plurality of longitudinal grooves 162 are spaced side-by-side across the inner face 164 of the jaw portion 150 . The grooves 162 extend the full longitudinal length of the jaw portion 150 . The same is true of a mirror image jaw portion, not shown. Both jaw portions are incorporated in a structure as in FIG. 3, and could be placed in substitution for jaw portions 48 , 50 in FIG. 3 . Grooves, not shown, also preferably extend along the corresponding jaw portions 48 , 50 of FIGS. 2-3. Orientations of the grooves other than longitudinal are considered possible, within the limit of construction and arrangement to substantially retain solution along the operative jaw portions.
Bodily tissues to be manipulated have a natural surface roughness. This roughness significantly reduces the area of contact between the forceps jaws and manipulated tissues. Air gaps are created between conventional smooth-surfaced jaws and tissues. If the jaws were energized when dry, electrical resistance in the tissues would be increased, and the current density and tissue temperature would be extremely high. In practice, tissue surfaces are sometimes wet in spots, and yet tissue wetness is not controlled, such that electrical power is to be set on the assumption the inner jaw surfaces are dry. This assumption is necessary to minimize unwanted arcing, charring and smoke.
In contrast, in a forceps according to the invention, whether the jaw portions are grooved or smooth, whether the grooves are longitudinal or otherwise oriented, the jaw portions are uniquely formed of a material such as hollow stainless steel needle tubing such that solution infusion openings 166 may be and are formed in the jaw inner faces such as the inner face 164 , as in FIG. 4 . Further, the solution supplies 52 , 54 shown by example in FIG. 3 may and do open into the openings 166 , to supply solution to the openings 166 . As most preferred, the openings 166 are laser drilled, and have a diameter in a range centered around four thousandths (0.004) of an inch, and most preferably in a range from two to six thousandths (0.002-0.006) inches.
The purpose of the openings 166 is to infuse solution onto and/or into the tissue adjacent to and otherwise in contact with the forceps jaw portions inner surfaces. It is understood the openings are appropriately as small in diameter as described above to assure more even flow among the openings than would otherwise occur. Further, the openings need not be so closely spaced as to mimic the surface roughness as tissues. Microporous surfaces are possibly acceptable, while they are also not necessary. Infusion of fluid through the jaws is to be maintained in a continuous flow during and throughout the application of RF energy in order for the desired tissue effect to be achieved.
With the described structure and similar structures and methods within the scope of the invention, numerous advantages are obtained. Deeper and quicker coagulation is possible. The conductive solution infused onto and into the tissues maintains relatively consistent maximal electrical contact areas, substantially preventing hot spots and allowing higher power than soft coagulation. Little to no arcing, cutting smoke or char is formed. Jaw and tissue surface temperatures are lower than otherwise, resulting in significantly less adhesion of tissue to jaw surfaces, and substantially no desiccation. One mode of coagulation may be used in the place of the three modes soft, forced, and spray. Coagulation is possible of even the most challenging oozing tissues such as lung, liver and spleen. tissues. Coagulation is more precise, where other coagulation modes sometimes spark to the sides and produce coagulation where not desired.
Also, and importantly, electrosurgical cutting by desiccation may be avoided, and tissue sealing achieved. As desired, tissue sealing may occur alone, or be accompanied with mechanical cutting, as by a retractable and advancable blade as in U.S. Pat. No. 5,458,598, and as with blade 1210 in FIG. 12, or otherwise. The tissue sealing itself is understood to occur by flow of electrolytic solution to the manipulating portions of the forceps in combination with energization of the solution with electrical energy, and when included, in combination with pressure on, or compression of the tissue. Compression of tissue is understood to deform tissues into conditions of sealing of tissues and especially vascalature. Compression of tissue followed by application of solution and energy is understood to permanently maintain compressed deformation of tissue, when present, and to shrink tissue and cause proteins to fix in place. Additional understanding of others is provided in the Yates et al. patent referenced above.
The body of the forceps itself may or not be energized. As most preferred, the solution primarily provides the beneficial functions and effects of the instrument. The effectiveness and extent of the tissue sealing is a function primarily of the type of tissue being manipulated, the quantity of electrolytic solution supplied to the tissue, and the power of the electrical energy supplied to the solution. Tissues not previously considered to be suitable for manipulation, as by cutting, are rendered suitable for manipulation by being sealed against flow of fluids, including bodily fluids and air. With the invention, for example, lung tissue may be cut after sealing, with the tissue adjacent the sealed tissue retaining blood and air. Examples of the principal parameters of specific uses of the invention are provided in the following table. It is understood that the combined consequences of the parameters are that energy density in the tissue to be treated is in a range to effect sealing of the tissue. However, in general, a power output of 7 to 150 watts is preferred.
Fluid Quantity
Power
Tissue
Effect
2 cc's per minute
20 watts for 30
1 cm diameter
hemostasis
per electrode
seconds
vessel
through the vessel
2 cc's per minute
30 watts for 45
lung tissue
hemostasis and
per electrode
seconds
aerostasis
4 cc's per minute
40 watts for 90
2 cm thickness
hemostasis
per electrode
seconds
liver tissue
In the examples for which the table is provided, the electrolytic solution is saline. In the first example, the device in use was a device as in FIG. 2, with electrodes of 16 gauge tubing, 1 cm long. The tool in use in the second and third examples was a forceps as in FIG. 6, with jaw portions 348 , 350 , to be described, 4 mm wide and 2.8 cm long. No desiccation was observed at the tissue/electrode interface. The device of FIG. 2 is preferred for vessel closure.
A wide variety of the currently installed electrosurgical generators could and will provide proper waveforms and power levels for driving the described forceps.
The waveforms need only be sine waves at about 500 kHz, and the power need only be about 30 or more watts. As example of available generators, Valleylab generators are acceptable and widely available.
The electrolytic solution supplied to the forceps need only be saline, although a variety of non-toxic and toxic electrolytic solutions are possible. Toxic fluids may be desirable when excising undesired tissues, to prevent seeding during excision. Use of a pressure bulb is possible, as shown in FIG. 8. A flexible reservoir such as an intravenous (IV) bag 410 is surrounded with a more rigid rubber bulb 412 that is pressurized with air through an attached squeeze bulb 414 . The reservoir is filled with solution through an injection port 416 . An outflow line 418 has a filter 420 and a capillary tube flow restrictor 422 to meter flow. A clamp or valve 424 and connector 426 are also provided. A typical flow rate is one to two (1-2) cc/min at a maximum pressure of approximately sixteen pounds per square inch (16 psi)(52 mmHg). An example of opening diameters, numbers, and flow rate is as follows: opening diameter, 0.16 mm; number of openings, 13 per cm; and flow rate, 2 cc's per minute. A long slit has also been used and found acceptable. In this embodiment, flow rates of 0.01 to 50 cc/min are preferred.
It is understood that highly significant to the invention is the spacing of a plurality of solution openings along the jaw inner surfaces. Single openings as in Ohta et al., that effectively pour fluid adjacent one portion of forceps, are generally not considered suitable or effective. Openings along outer surfaces of the jaws, opposite inner surfaces, are also generally not considered suitable or effective.
Referring to FIGS. 4 and 5, the configurations of the most preferred solution openings are disclosed. Referring to FIG. 5, in a jaw 240 , longitudinally spaced openings 166 are rotated from those shown in FIG. 4, in a jaw portion 250 , to turn the openings away from most direct contact with tissues, and more carefully eliminate any unintended plugging of the openings. Electrical insulators 268 in the form of elongated strips extend alongside the tubes which include the openings 166 .
Referring to FIG. 6, open surgical forceps 330 include jaws 338 , 340 with jaw portions 348 , 350 . As with jaw portion 350 in FIG. 7, the jaw portions 348 , 350 include spaced solution infusion openings 166 in the central longitudinal groove of a plurality of grooves 162 . A central channel 370 of both jaw portions 348 , 350 , as shown relative to jaw portion 350 in FIG. 7, supplies solution to the openings 166 from solution supplies 52 , 54 . As with the endoscopic forceps of FIGS. 2-5, the open surgical forceps 330 benefits from the unique enhancement of electrosurgical functions through the infusion of electrolytic solutions onto and into tissues through the spaced, laser drilled, solution infusion openings in the grooves 162 .
Referring to FIGS. 9 and 10, open surgical devices 430 and 530 also include jaws 438 , 440 and 538 , 540 , respectively. The jaw portions of these devices are curved, and in the case of device 430 , circular, to adapt the invention to specialized surgical situations of tissue manipulation, such as those in which fluid flow is to be terminated all around a tissue to be isolated and resected or excised. An example of such a tissue is a lesion or tumor of lung tissue. In endoscopic or open surgery, such lesions or tumors may be encircled and/or isolated, surrounding tissue sealed, and the lesions or tumors thereafter resected. Preferably, a one centimeter margin is resected about any lesion or tumor, with the lesion or tumor. As shown, the devices 430 , 530 are formed of substantially square cross-section tubing, best shown in the cross-sectional drawing of FIG. 11 . As most preferred, the tubing incorporates a central, depressed, cross-sectionally rectangular, and elongated groove 462 and equilaterally spaced, cross-sectionally triangular, parallel, and elongated outer grooves 464 , 465 . Laser drilled openings 466 , similar to openings 166 described above, are located in and spaced along the central groove 462 .
Alternate cross-sectional shapes of tubing may be employed, as exemplified in FIG. 12 . Flatter operative, e.g., inner faces of tubing are preferred within limits of constructing and arranging the operative faces to facilitate firm grasping and holding of tissue. Non-operative surfaces, being less of concern, may adapt to a variety of contours for a variety of alternate reasons. Further, malleable tubing may be employed, to permit the surgeon to shape the operative portions of the invented devices to specific physiological situations.
The infusion of conductive solutions, referred to here also as electrolytic solutions, simultaneously with the application of RF energy to tissues is discussed in further detail in U.S. Pat. No. 5,431,649 entitled “Method and Apparatus for R-F Ablation,” in the name of Peter M. J. Mulier and Michael F. Hoey; in U.S. Pat. No. 5,609,151, entitled “Method and Apparatus for R-F Ablation,” in the name of Peter M. J. Mulier. The foregoing patents are commonly assigned to the assignee of the present invention, and are incorporated by reference here.
The preferred embodiments, and the processes of making and using them, are now considered to be described in such full, clear, concise and exact terms as to enable a person of skill in the art to make and use the same. Those skilled in the art will recognize that the preferred embodiments may be altered and modified without departing from the true spirit and scope of the invention as defined in the appended claims. For example, if the invented device is incorporated in forceps, the forceps may be varied in a range from excision and cutting biopsy forceps, to endoscopic forceps, dissecting forceps, and traumatic, atraumatic and flexible endoscopic grasping forceps. The jaws may close into full and tight contact with each other, or close into spaced relationship to each other, to accommodate tissue for purposes other than cutting. As expressed above, parallel spaced relationship is considered most preferably for uniformity of application of pressure across tissue to be affected.
A variety of features such as jaw serrations, single acting and double acting jaws, closing springs, ratchet locks, fingertip rotation rings, color coding and smoke aspiration may or may not be included with the features described in detail. Devices according to the invention may be constructed and arranged to grasp, hold, fix, cut, dissect, expose, remove, extract, retrieve, and otherwise manipulate and treat organs, tissues, tissue masses, and objects. Endoscopic forceps according to the invention may be designed to be used through a trocar. Bipolar and monopolar currents may both be used. With monopolar current, grounding pads may be placed under patients. The described grooves may be eliminated in favor of alternative grooves.
For purposes of the appended claims, the term “manipulate” includes the described functions of grasping, holding, fixing, cutting, dissecting, exposing, removing, extracting, retrieving, coagulating, ablating and otherwise manipulating or similarly treating organs, tissues, tissue masses, and objects. Also for purposes of the appended claims, the term “tissue” includes organs, tissues, tissue masses, and objects. Further for purposes of the appended claims, the term “electrical energy sufficient to affect tissue” includes electrical energy sufficient to raise tissue temperature to cause non-reversible effect on tissue as described above.
To particularly point out and distinctly claim the subject matter regarded as invention, the following claims conclude this specification. | An electrosurgery medical device is enhanced with unique solution-assistance, and comprises, in combination, co-operating device jaws including jaw portions for manipulating tissue, and a plurality of solution infusion openings defined and spaced along each of the jaw portions, for receiving electrolytic solution and infusing the solution onto and into tissue to be manipulated, along said jaw portions. As preferred, the device further comprises at least one, and most preferably, many, longitudinal groove(s) along at least one and most preferably, both, of the jaw portions, with the solution infusion openings located in the groove or grooves. The solution is energized with RF energy and contributes to the functions and beneficial effects of the instrument. The solution exits the openings in the grooves at sufficient flow rates to separate substantially all the operative surfaces of the device from tissue, thereby substantially completely preventing adherence between the operative surfaces and tissue. The solution is further energized to a range of energy densities such that tissues to be affected are sealed against flow of blood, lymphatic fluids, air, and other bodily fluids and gases. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application Ser. No. 61/436,105, filed Jan. 25, 2011, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] Embodiments of the invention relate generally to improved semiconductor imaging devices and in particular to the manner of operating an array of pixels.
BACKGROUND OF THE INVENTION
[0003] A conventional four transistor (4T) circuit for a pixel 150 of a CMOS imager is illustrated in FIG. 1 . The FIG. 1 pixel 150 is a 4T pixel, where 4T is commonly used in the art to designate use of four transistors to operate the pixel. The 4T pixel 150 has a photosensor such as a photodiode 162 , a reset transistor 184 , a transfer transistor 190 , a source follower transistor 186 , and a row select transistor 188 . It should be understood that FIG. 1 shows the circuitry for operation of a single pixel 150 , and that in practical use, there will be an M×N array of pixels arranged in rows and columns with the pixels of the array accessed using row and column select circuitry, as described in more detail below.
[0004] The photodiode 162 converts incident photons to electrons which are selectively passed to a floating diffusion stage node A through transfer transistor 190 when activated by the TX control signal. The source follower transistor 186 has its gate connected to node A and thus amplifies the signal appearing at the floating diffusion node A. When a particular row containing pixel 150 is selected by an activated row select transistor 188 , the signal amplified by the source follower transistor 186 is passed on a column line 170 to column readout circuitry. The photodiode 162 accumulates a photo-generated charge in a doped region of the substrate. It should be understood that the pixel 150 may include a photogate or other photon to charge converting device, in lieu of a photodiode, as the initial accumulator for photo-generated charge.
[0005] The gate of transfer transistor 190 is coupled to a transfer control signal line 191 for receiving the TX control signal, thereby serving to control the coupling of the photodiode 162 to node A. A voltage source Vpix is coupled through reset transistor 184 and conductive line 163 to node A. The gate of reset transistor 184 is coupled to a reset control line 183 for receiving the Rst control signal to control the reset operation in which the voltage source Vpix is connected to node A.
[0006] A row select signal (Row Sel) on a row select control line 160 is used to activate the row select transistor 188 . Although not shown, the row select control line 160 used to provide a row select signal (Row Sel) is coupled to all of the pixels of the same row of the array, as are the RST and TX lines. Voltage source Vpix is coupled to transistors 184 and 186 by conductive line 195 . A column line 170 is coupled to all of the pixels of the same column of the array and typically has a current sink 176 at its lower end. The upper part of column line 170 , outside of the pixel array, includes a pull-up circuit 111 which is used to selectively keep the voltage on the column line 170 high. Maintaining a positive voltage on the column line 170 during an image acquisition phase of a pixel 150 keeps the potential in a known state on the column line 170 . Signals from the pixel 150 are therefore selectively coupled to a column readout circuit ( FIGS. 2-4 ) through the column line 170 and through a pixel output (“Pix_out”) line 177 coupled between the column line 170 and the column readout circuit.
[0007] As known in the art, a value can be read from pixel 150 in a two step correlated double sampling process. First, node A is reset by activating the reset transistor 184 . The reset signal (e.g., Vpix) found at node A is readout to column line 170 via the source follower transistor 186 and the activated row select transistor 188 . During a charge integration period, photodiode 162 produces a charge from incident light. This is also known as the image acquisition period. After the integration period, transfer transistor 190 is activated and the charge from the photodiode 162 is passed through the transfer transistor to node A, where the charge is amplified by source follower transistor 186 and passed to column line 170 through the row select transistor 188 . As a result, two different voltage signals—the reset signal and the integrated charge signal—are readout from the pixel 150 and sent on the column line 170 to column readout circuitry where each signal is sampled and held for further processing as known in the art. Typically, all pixels in a row are readout simultaneously onto respective column lines 170 and the column lines may be activated in sequence for pixel reset and signal voltage readout.
[0008] FIG. 2 shows an example CMOS imager integrated circuit chip 201 that includes an array 230 of pixels and a controller 232 , which provides timing and control signals to enable reading out of signals stored in the pixels in a manner commonly known to those skilled in the art. Exemplary arrays have dimensions of M×N pixels, with the size of the array 230 depending on a particular application. The pixel signals from the array 230 are readout a row at a time using a column parallel readout architecture. The controller 232 selects a particular row of pixels in the array 230 by controlling the operation of row addressing circuit 234 and row drivers 240 . Signals corresponding to charges stored in the selected row of pixels and reset signals are provided on the column lines 170 to a column readout circuit 242 in the manner described above. The pixel signal read from each of the columns can be readout sequentially using a column addressing circuit 244 . Pixel signals (Vrst, Vsig) corresponding to the readout reset signal and integrated charge signal are provided as respective outputs Vout 1 , Vout 2 of the column readout circuit 242 where they are subtracted in differential amplifier 246 , digitized by analog to digital converter 248 , and sent to an image processor circuit 250 for image processing.
[0009] FIG. 3 shows more details of the rows and columns 249 of active pixels 150 in an array 230 . Each column includes multiple rows of pixels 150 . Signals from the pixels 150 in a particular column can be readout to sample and hold circuitry 261 associated with the column 249 (part of circuit 242 ) for acquiring the pixel reset and integrated charge signals. Signals stored in the sample and hold circuits 261 can be read sequentially column-by-column to the differential amplifier 246 which subtracts the reset and integrated charge signals and sends them to an analog-to-digital converter (ADC) 248 .
[0010] FIG. 4 illustrates a portion of the sample and hold circuit 261 of FIG. 3 in greater detail. The sample and hold circuit 261 holds a set of signals, e.g., a reset signal and an integrated charge signal from a desired pixel. For example, a reset signal of a desired pixel on column line 170 is stored on capacitor 228 and the integrated charge signal is stored on capacitor 226 .
[0011] The operation of the circuits illustrated in FIGS. 1-4 is now described with reference to the simplified signal timing diagram of FIG. 5 . During an image acquisition/reset period 290 , the pull-up circuit 111 is enabled (via the PULLUP signal) to maintain the column line 170 at a high level and the signal on the row select line 160 is set to a logic low to disable the row select transistor 188 and isolate the pixel 150 from the column line 170 .
[0012] A readout period 298 for pixel 150 is separated into a readout period 292 for the readout of the reset signal, and a readout period 294 for the readout of the integrated charge signal. To begin the overall readout period 298 , the pull-up circuit 111 is disabled to no longer maintain the column line 170 at a high level and the signal on the row select line 160 is set to a logic high to enable the row select transistor 188 and couple the pixel 150 to the column line 170 . To begin the reset signal readout period 292 , the reset signal RST is enabled placing the reset voltage Vpix on node A which is transferred to the column line 170 via source follower transistor 186 and row select transistor 188 and stored in capacitor 228 when the SHR pulse is applied to switch 220 of the sample and hold circuit 261 ( FIG. 4 ). Thus, reset signal (Vrst) of the desired pixel 150 is sampled and stored on capacitor 228 . After the reset signal is stored, the reset readout period 292 ends.
[0013] After the reset readout period 292 ends, an integrated charge signal readout period 294 begins. Transfer transistor 190 is enabled by a transfer control signal Tx being pulsed on line 191 . The integrated charge which has been integrating at photodiode 162 is transferred onto Node A. Subsequently, the integrated charge signal on node A is transferred onto the column line 170 via source follower transistor 186 and row select transistor 188 and stored in capacitor 226 when an SHS signal is applied to switch 222 of the sample and hold circuit 261 ( FIG. 4 ). The SHS switch 222 ( FIG. 4 ) of the sample and hold circuit 261 is closed thereby storing an integrated charge pixel signal on capacitor 226 . The reset and integrated charge signals stored in the sample and hold circuit 261 for the column are now available for the differential readout circuit. The integrated charge signal readout period 294 and the readout period 298 is completed. As part of the next acquisition/reset period 296 , the pull-up circuit 111 is enabled to maintain the column line 170 at a high level and the signal on the row select line 160 is set to a logic low to disable the row select transistor 188 and isolate the pixel 150 from the column line 170 .
[0014] The circuitry described above requires space in an imager. However, there exists a need to reduce the size of imagers, and thus, it is desirable to eliminate circuitry from pixels, which helps reduce size and improves the pixel fill factor by permitting a larger area for the photodiode.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is an electrical schematic diagram of a conventional imager pixel.
[0016] FIG. 2 is a block diagram of a conventional imager chip.
[0017] FIG. 3 is a block diagram of an array of pixels illustrated in FIG. 2 and an associated column readout circuit.
[0018] FIG. 4 is a conventional sample and hold circuit.
[0019] FIG. 5 is a simplified timing diagram associated with operation of the circuitry of FIGS. 1-4 .
[0020] FIG. 6A is an electrical schematic diagram of a pixel circuit where the reset transistor is controlled by a signal on the column line.
[0021] FIG. 6B is an electrical schematic diagram of a pixel circuit similar to the pixel circuit shown in FIG. 6A , except that the pixel circuit includes a pull down transistor, in accordance with an example of the present invention.
[0022] FIG. 7A is a timing diagram associated with the pixel of FIG. 6A .
[0023] FIG. 7B is a timing diagram associated with the pixel of FIG. 6B , in accordance with an example of the present invention.
[0024] FIG. 8 is an electrical schematic diagram of a pixel circuit, in accordance with another example of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments. These embodiments are described in sufficient detail to enable those of ordinary skill in the art to make and use them, and it is to be understood that structural, logical, or procedural changes may be made.
[0026] The embodiments described herein provide an improved imager and method of operation where the reset transistor is controlled by the signal on the column line. This control arrangement reduces the circuitry required to operate the pixel array of the imager. Dedicated reset control lines and corresponding row drivers are eliminated to reduce the area needed for a pixel and the associated circuitry.
[0027] Various imager pixel architectures having a column discharge are described in International Application Number PCT/US2008/063840, titled “Imager and System Utilizing Pixel with Internal Reset Control and Method of Operating Same,” which claims priority to U.S. application Ser. No. 11/802,200, filed on May 21, 2007. These applications are incorporated herein by reference in their entireties.
[0028] According to a first example described in the aforementioned applications, reference is now made to a pixel circuit shown in FIG. 6A . As shown, the gate of the reset transistor 384 is coupled to and controlled by a signal on the column line 170 through a signal on the Pix_out line 177 . The pixel 350 is similar to pixel 150 of FIG. 1 except that the gate of the reset transistor 384 is no longer coupled to a reset control line, but instead, the gate of the reset transistor 384 is coupled to the Pix_out line 177 through line 391 . The drivers and circuitry required to control and drive the dedicated reset control line 183 ( FIG. 1 ) are eliminated. In FIG. 6A , the signal on the Pix_out line 177 is used to reset the floating diffusion node A, thus maintaining the operation of the 4T pixel. Thus, when the pull-up circuit 111 is enabled and applying a positive voltage to the column line 170 , a positive voltage is also applied through the Pix_out line 177 and line 391 to the gate of the reset transistor 384 . Applying a positive voltage to the gate of the reset transistor 384 activates the transistor 384 and couples the floating diffusion node A to the voltage source Vpix.
[0029] The remaining structures of pixel 350 and their operations correspond to like structures and their operations as described above with respect to FIG. 1 .
[0030] The threshold of the reset transistor 384 affects the voltage of the floating diffusion node A (V FD ). If the threshold of reset transistor 384 , V rst — th , is zero (0), then subsequent to a reset operation, the voltage of the floating diffusion node A V FD , is equal to Vpix. If the reset transistor 384 threshold is not zero, then subsequent to a reset V FD operation, the voltage on node A, V FD , is:
[0000] V FD =Vpix−V rs — th (1)
[0031] The operation of the circuit of FIG. 6A is now described with reference to the simplified signal timing diagram of FIG. 7A . The timing diagram is illustrative of the timing of a readout of a pixel from a pixel array, as well as a portion of an acquisition/reset period that precedes and a portion of another acquisition/reset period that follows the readout period. This timing diagram of FIG. 7A is representative of the readout of each of the pixels from a pixel array.
[0032] Line 202 represents the SHR signal used to store a reset signal on a sample and hold capacitor for storing the reset signal. When SHR is logic high, switch 220 ( FIG. 4 ) is closed and capacitor 228 is coupled to the column line 170 . When SHR is logic low, switch 220 is open and capacitor 228 is uncoupled from the column line 170 .
[0033] Line 203 ( FIG. 7A ) represents the Tx control signal at a given time. When the Tx control signal is logic high, Tx transistor 190 ( FIG. 6A ) is activated and photodiode 162 is coupled to floating diffusion node A. When the Tx control signal is logic low, Tx transistor 190 is open and photodiode 162 is uncoupled from floating diffusion node A. Line 204 ( FIG. 7A ) represents the SHS signal used to store a integrated charge signal on a sample and hold capacitor for storing integrated charge signals. When SHS is logic high, switch 222 ( FIG. 4 ) is closed and capacitor 226 is coupled to the column line 170 . When SHS is logic low, switch 222 is open and capacitor 226 is uncoupled from the column line 170 .
[0034] Line 205 ( FIG. 7A ) represents the Row SeI signal at a given time. When the Row SeI signal is logic high, row select transistor 188 ( FIG. 6A ) is activated and pixel 350 is coupled to the column line 170 . When the Row SeI signal is logic low, row select transistor 188 is open and pixel 350 is uncoupled from the column line 170 . Line 206 ( FIG. 7A ) represents the PULLUP signal controlling the pull-up circuit 111 at a given time. When PULLUP is logic high, pull-up circuit 111 ( FIG. 6A ) is enabled and providing a voltage on column line 170 . When PULLUP is logic low, pull-up circuit 111 is disabled and not providing a voltage on column line 170 . Line 207 ( FIG. 7A ) represents the voltage on the Pix_out line 177 ( FIG. 6A ) at a given time. Line 208 ( FIG. 7A ) represents the voltage on the floating diffusion (FD) node A ( FIG. 6A ) at a given time.
[0035] During an acquisition/reset period 790 , the pull-up circuit 111 is enabled (logic high PULLUP signal) to maintain the column line 170 at a high level and the row select (Row SeI) signal on the row select line 160 is set to a logic low to disable the row select transistor 188 and isolate the source follower transistor 186 from the column line 170 . During acquisition/reset period 790 , the integrated charge signal is being accumulated by photodiode 162 . Also during the acquisition/reset period 790 , since the Pix_out line 177 is coupled to the column line 170 , the Pix_out line 177 is at a high level, which activates reset transistor 384 , thereby coupling floating diffusion node A to the reset voltage Vpix. Assuming that pull-up circuit 111 provides a 2.8V voltage and also assuming that there is no significant loss of voltage in the circuit, then when pull-up circuit 111 is at a high level and therefore Pix_put line 177 is at a high level, the voltage on Pix_out line 177 is equivalent to the voltage provided by the pull-up circuit, 2.8V.
[0036] As depicted in FIG. 7A , the voltage on Pix_out line 177 ( FIG. 7A , line 208 ) during the acquisition/reset period 790 is 2.8V. Similarly, when a floating diffusion node A is reset to Vpix, the V FD voltage on node A is 2.8V ( FIG. 7A , line 207 ), assuming no voltage loss in the circuit. In most implementations, the V FD is related to the physical properties of the reset transistor, as indicated above with respect to Eq. (1). Thus, a reset signal is provided to the floating diffusion node A without a dedicated reset line such as the one shown in FIG. 1 .
[0037] A readout period 798 for pixel 350 is separated into a readout period 792 for the readout of the reset signal, and a readout period 794 for the readout of the integrated charge signal. To begin the overall readout period 798 , the pull-up circuit 111 is disabled to no longer maintain the column line 170 at a high level and the Row SeI signal on the line 160 is set to a logic high to enable the row select transistor 188 and couple the pixel 350 to the column line 170 .
[0038] To begin the reset signal readout period 792 , the reset signal on floating diffusion node A is transferred to the column line 170 via source follower transistor 186 and row select transistor 188 and stored in capacitor 228 when the SHR pulse is applied to switch 220 of the readout circuit 242 ( FIG. 4 ). Thus, the reset signal (e.g., Vrst) of the desired pixel 350 is sampled and stored on capacitor 228 . After the reset signal is stored, the reset readout period 792 ends.
[0039] After the reset readout period 792 ends, the integrated charge signal readout period 794 begins. Transfer transistor 190 is enabled by a transfer control signal Tx being pulsed on line 191 . The integrated charge from photodiode 162 is transferred onto floating diffusion node A. Subsequently, the integrated charge signal on floating diffusion node A is transferred onto the column line 170 via source follower transistor 186 and row select transistor 188 and stored in capacitor 226 when the SHS signal is applied to switch 222 of the column readout circuit 242 ( FIG. 4 ). The SHS switch 222 of the column readout circuit 242 is closed thereby storing an integrated charge pixel signal on capacitor 226 . The reset and integrated charge signals stored in the sample and hold circuits 242 for the column are now available for the differential readout circuit 246 ( FIG. 2 ). The integrated charge signal readout period 794 and the readout period 798 is completed.
[0040] As depicted in FIG. 7A , the voltage on Pix_out line 177 ( FIG. 7A , line 208 ) and the floating diffusion node A ( FIG. 7A , line 207 ) changes during the readout period 798 . During the reset readout period 792 , when the Row_sel is enabled the voltage on the Pix_out line 177 decreases due to the threshold voltage on source follower transistor 186 . The voltage on the gate of the reset gate 384 is also reduced, which builds a barrier for a potential wall on the floating diffusion node A equivalent to:
[0000] V B =V SF — th (2)
[0041] If V SF — th =0.8V, then the voltage on the Pix_out line 177 drops to 2.0V.
[0042] During the integrated charge signal readout period 794 , the voltage on the Pix_out line 177 decreases due to the transferring of the charge from the photodiode 162 to the floating diffusion node A equivalent to Q/C FD , where Q is the integrated charge of the photodiode 162 and C FD is the capacitance of the floating diffusion node A. In the example of FIG. 7A , Q/C FD =1, thus the voltage on Pix_out line 177 decreases 1.0 V. Correspondingly, the voltage on the Pix_out line and the reset gate 384 is reduced to 1.0V.
[0043] With the reduction of the voltage on the Pix_out line 177 , the barrier on the potential wall on the floating diffusion node A is
[0000] Vc=V SF — th +Q/C FD (2),
[0000] and
[0000] V FD =1.8 V, as depicted in FIG. 7 A.
[0044] As part of the next acquisition/reset period 796 , the pull-up circuit 111 is enabled to maintain the column line 170 at a high level and the signal on the row select line 160 is set to a logic low to disable the row select transistor 188 and isolate the pixel 350 from the column line 170 . Although not shown, node A of pixel 350 is reset by reset voltage Vpix during the acquisition/reset period 796 in a similar manner as described above, whereby the pull-up circuit 111 is enabled to maintain the column line 170 at a high level and the signal on the row select line 160 is set to a logic low to disable the row select transistor 188 and isolate the source follower transistor 186 of pixel 350 from the column line 170 . Similar to acquisition/reset period 790 , during acquisition period 796 the voltage on node A and on Pix_out line 177 is reset to 2.8V.
[0045] Therefore, the pixel can be operated without the need for a dedicated reset line and associated circuitry; in other words, it may have an internal reset operation. This can decrease the size required for the image sensor and corresponding circuitry. While the pixel shown in FIG. 6A has a number of advantages, when compared to a conventional 4 -T pixel architecture, it has fundamental limitations. One limitation is its slow readout time which limits its use in high speed applications. The Pix_out line 177 discharges slowly from 2.8V to 2.0V during the reset period of the readout cycle, as shown in signal line 208 in FIG. 7A .
[0046] The column Pix_out line is first pulled up to a high voltage (2.8V) to reset the floating diffusion. This is a fast process. The Pix_out line, however, has to subsequently be discharged by a constant current provided by current mirror circuit 176 . This is a slow process that limits the readout speed of this imager pixel architecture.
[0047] A possible solution to tackle this problem may be to increase the discharging current to speed up the discharge process. One drawback of this approach is that power consumption is increased. The other drawback is that it lowers the SHR value of the pixel, which causes a reduction in full well capacity of the pixel if it is limited by the voltage swing of node A.
[0048] Another solution to tackle this problem is an internal reset architecture with enhanced column discharge (IRECD). A first embodiment of an IRECD device, in accordance to the present invention, is shown in FIG. 6B , with its associated timing diagram shown in FIG. 7B .
[0049] As shown in FIG. 6B , an enhanced column discharge (ECD) is provided by the NMOS transistor pull down device, designated as 171 . One terminal of transistor 171 is connected to the column Pix_out line 177 (also line 170 ). The other terminal is connected to a column pull down voltage, V CPD . The gate of NMOS transistor 171 is controlled by a column pull down signal, CPD.
[0050] In the IRECD device, instead of relying on the constant current provided by a current mirror circuit to discharge the column Pix_out line, the present invention makes use of a constant voltage discharge to discharge the column Pix_out line.
[0051] Referring now to FIG. 7B , the CPD line, designated as 209 , is activated immediately after disabling PULLUP line 206 . The CPD command causes a rapid discharge of the Pix_out signal 208 . The signal timing shown in FIG. 7B is similar to the timing shown in FIG. 7A , except for the Pix_out signal 208 . In comparing FIG. 7B to FIG. 7A , it will be appreciated that transistor 171 very rapidly pulls down the voltage of the Pix_out signal, while absence of transistor 171 allows a much slower current discharge through current mirror 176 of the Pix_out signal.
[0052] An important advantage of the IRECD circuit (device) is that the discharge settling time may be made even faster by choosing the appropriate pull down voltage. The present invention allows tuning for the best pixel performance, even after the chip is manufactured. In particular, if the pull down voltage is tuned such that it is close to the final SHR value, the settling time may be made even faster. This is similar to a critically damped circuit in a second-order system.
[0053] It will be appreciated that the present invention's use of an NMOS device to quickly bring the column line to its SHR value may also be applied to other imager architecture (e.g. regular 4-T pixel) to enhance their speed performance. Accordingly, an internal reset of the reset transistor need not be used, but the pull down transistor may, nevertheless, be used to speed up imager performance.
[0054] FIG. 8 depicts a pixel 550 according to a second embodiment of the present invention. The pixel 550 is similar to pixel 350 of FIG. 6B except that one source/drain of reset transistor 584 is coupled to floating diffusion node A and the other source/drain of reset transistor 584 is coupled to the pull up voltage on the column line 170 through Pix_out line 177 , i.e., the other source/drain of reset transistor 584 is coupled to the gate of reset transistor 584 . The method of operating the pixel 550 is similar to the method of operating pixel 350 as described above with respect to FIG. 7B , except here the operating voltage for reset transistor 584 is also taken from the voltage on column line 170 . The arrangement of having a source/drain of reset transistor 584 coupled to the gate of reset transistor 584 also known as a diode connected transistor.
[0055] Although the embodiments described utilize a single pixel, they are not so limited and are also applicable to shared pixel arrays in which more than one photosensor from different pixels are switchably coupled to a common floating diffusion node. Descriptions of shared pixel arrays are provided in PCT/US2008/063840, which is incorporated herein by reference in its entirety.
[0056] While the invention has been described and illustrated with reference to specific example embodiments, it should be understood that many modifications and substitutions can be made. Although the embodiments discussed above describe specific numbers of transistors, photodiodes, conductive lines, etc., they are not so limited. Accordingly, the invention is not to be considered as limited by the foregoing description but is only limited by the scope of the claims. | A pixel circuit includes a photosensor and a floating diffusion node. A circuit is coupled to the floating diffusion node, for selectively providing a pixel output signal to a column line. A reset circuit, which resets the floating diffusion node, is configured to be activated by the column line. A pullup circuit is included for controlling the reset circuit through a signal on the column line. A discharge circuit, which is separate from the reset circuit, is used for discharging the pixel output signal on the column line. The discharge circuit includes a transistor having a first source/drain terminal coupled to the column line and a second source/drain terminal coupled to a fixed voltage level. The gate of the transistor activates the discharging of the column line. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 12/544,819, filed on Aug. 20, 2009, which issued as U.S. Pat. No. 8,437,829, which is a continuation of U.S. patent application Ser. No. 11/174,222, filed on Jul. 1, 2005, which issued as U.S. Pat. No. 7,670,470, which is a continuation of U.S. patent application Ser. No. 10/146,518, filed on May 14, 2002, which issued as U.S. Pat. No. 6,932,894, which claims benefit of U.S. Provisional Application Ser. No. 60/291,215 of Fei Mao, filed on May 15, 2001 and entitled “Biosensor Membranes Composed of Polyvinylpyridines”, which are incorporated by reference herein in their entirety.
FIELD OF THE INVENTION
This invention generally relates to an analyte-flux-limiting membrane. More particularly, the invention relates to such a membrane composed of polymers containing heterocyclic nitrogens. The membrane is a useful component in biosensors, and more particularly, in biosensors that can be implanted in a living body.
BACKGROUND OF THE INVENTION
Enzyme-based biosensors are devices in which an analyte-concentration-dependent biochemical reaction signal is converted into a measurable physical signal, such as an optical or electrical signal. Such biosensors are widely used in the detection of analytes in clinical, environmental, agricultural and biotechnological applications. Analytes that can be measured in clinical assays of fluids of the human body include, for example, glucose, lactate, cholesterol, bilirubin and amino acids. The detection of analytes in biological fluids, such as blood, is important in the diagnosis and the monitoring of many diseases.
Biosensors that detect analytes via electrical signals, such as current (amperometric biosensors) or charge (coulometric biosensors), are of special interest because electron transfer is involved in the biochemical reactions of many important bioanalytes. For example, the reaction of glucose with glucose oxidase involves electron transfer from glucose to the enzyme to produce gluconolactone and reduced enzyme. In an example of an amperometric glucose biosensor, glucose is oxidized by oxygen in the body fluid via a glucose oxidase-catalyzed reaction that generates gluconolactone and hydrogen peroxide, whereupon the hydrogen peroxide is electrooxidized and correlated to the concentration of glucose in the body fluid. (Thomé-Duret, V., et al., Anal. Chem. 68, 3822 (1996); and U.S. Pat. No. 5,882,494 of Van Antwerp.) In another example of an amperometric glucose biosensor, the electrooxidation of glucose to gluconolactone is mediated by a polymeric redox mediator that electrically “wires” the reaction center of the enzyme to an electrode. (Csöregi, E., et al., Anal. Chem. 66, 3131 (1994); Csöregi, E., et al., Anal. Chem. 67, 1240 (1995); Schmidtke, D. W., et al., Anal. Chem. 68, 2845 (1996); Schmidtke, D. W., et al., Anal. Chem. 70, 2149 (1998); and Schmidtke, D. W., et al., Proc. Natl. Acad. Sci. U.S.A. 95, 294 (1998).)
Amperometric biosensors typically employ two or three electrodes, including at least one measuring or working electrode and one reference electrode. In two-electrode systems, the reference electrode also serves as a counter-electrode. In three-electrode systems, the third electrode is a counter-electrode. The measuring or working electrode is composed of a non-corroding carbon or a metal conductor and is connected to the reference electrode via a circuit, such as a potentiostat.
Some biosensors are designed for implantation in a living animal body, such as a mammalian or a human body, merely by way of example. In an implantable amperometric biosensor, the working electrode is typically constructed of a sensing layer, which is in direct contact with the conductive material of the electrode, and a diffusion-limiting membrane layer on top of the sensing layer. The sensing layer typically consists of an enzyme, an enzyme stabilizer such as bovine serum albumin (BSA), and a crosslinker that crosslinks the sensing layer components. Alternatively, the sensing layer consists of an enzyme, a polymeric mediator, and a crosslinker that crosslinks the sensing layer components, as in the above-mentioned “wired-enzyme” biosensor.
In an implantable amperometric glucose sensor, the membrane is often beneficial or necessary for regulating or limiting the flux of glucose to the sensing layer. By way of explanation, in a glucose sensor without a membrane, the flux of glucose to the sensing layer increases linearly with the concentration of glucose. When all of the glucose arriving at the sensing layer is consumed, the measured output signal is linearly proportional to the flux of glucose and thus to the concentration of glucose. However, when the glucose consumption is limited by the kinetics of chemical or electrochemical activities in the sensing layer, the measured output signal is no longer controlled by the flux of glucose and is no longer linearly proportional to the flux or concentration of glucose. In this case, only a fraction of the glucose arriving at the sensing layer is consumed before the sensor becomes saturated, whereupon the measured signal stops increasing, or increases only slightly, with the concentration of glucose. In a glucose sensor equipped with a diffusion-limiting membrane, on the other hand, the membrane reduces the flux of glucose to the sensing layer such that the sensor does not become saturated and can therefor operate effectively within a much wider range of glucose concentration.
More particularly, in these membrane-equipped glucose sensors, the glucose consumption rate is controlled by the diffusion or flux of glucose through the membrane rather than by the kinetics of the sensing layer. The flux of glucose through the membrane is defined by the permeability of the membrane to glucose, which is usually constant, and by the concentration of glucose in the solution or biofluid being monitored. When all of the glucose arriving at the sensing layer is consumed, the flux of glucose through the membrane to the sensing layer varies linearly with the concentration of glucose in the solution, and determines the measured conversion rate or signal output such that it is also linearly proportional to the concentration of glucose concentration in the solution. Although not necessary, a linear relationship between the output signal and the concentration of glucose in the solution is ideal for the calibration of an implantable sensor.
Implantable amperometric glucose sensors based on the electrooxidation of hydrogen peroxide, as described above, require excess oxygen reactant to ensure that the sensor output is only controlled by the concentration of glucose in the body fluid or tissue being monitored. That is, the sensor is designed to be unaffected by the oxygen typically present in body fluid or tissue. In body tissue in which the glucose sensor is typically implanted, the concentration of oxygen can be very low, such as from about 0.02 mM to about 0.2 mM, while the concentration of glucose can be as high as about 30 mM or, more. Without a glucose-diffusion-limiting membrane, the sensor would become saturated very quickly at very low glucose concentrations. The sensor thus benefits from having a sufficiently oxygen-permeable membrane that restricts glucose flux to the sensing layer, such that the so-called “oxygen-deficiency problem,” a condition in which there is insufficient oxygen for adequate sensing to take place, is minimized or eliminated.
In implantable amperometric glucose sensors that employ wired-enzyme electrodes, as described above, there is no oxygen-deficiency problem because oxygen is not a necessary reactant. Nonetheless, these sensors require glucose-diffusion-limiting membranes because typically, for glucose sensors that lack such membranes, the current output reaches a maximum level around or below a glucose concentration of 10 mM, which is well below 30 mM, the high end of clinically relevant glucose concentration.
A diffusion-limiting membrane is also of benefit in a biosensor that employs a wired-enzyme electrode, as the membrane significantly reduces chemical and biochemical reactivity in the sensing layer and thus reduces the production of radical species that can damage the enzyme. The diffusion-limiting membrane may also act as a mechanical protector that prevents the sensor components from leaching out of the sensor layer and reduces motion-associated noise.
There have been various attempts to develop a glucose-diffusion-limiting membrane that is mechanically strong, biocompatible, and easily manufactured. For example, a laminated microporous membrane with mechanical holes has been described (U.S. Pat. No. 4,759,828 of Young et al.) and membranes formed from polyurethane are also known (Shaw, G. W., et al., Biosensors and Bioelectronics 6, 401 (1991); Bindra, D. S., et al., Anal. Chem. 63, 1692 (1991); Shichiri, M., et al., Horm. Metab. Res., Suppl. Ser. 20, 17 (1988)). Supposedly, glucose diffuses through the mechanical holes or cracks in these various membranes. Further by way of example, a heterogeneous membrane with discrete hydrophobic and hydrophilic regions (U.S. Pat. No. 4,484,987 of Gough) and homogenous membranes with both hydrophobic and hydrophilic functionalities (U.S. Pat. Nos. 5,284,140 and 5,322,063 of Allen et al.) have been described. However, all of these known membranes are difficult to manufacture and have inadequate physical properties.
An improved membrane formed from a complex mixture of a diisocyanate, a diol, a diamine and a silicone polymer has been described in U.S. Pat. No. 5,777,060 (Van Antwerp), U.S. Pat. No. 5,786,439 (Van Antwerp et al.) and U.S. Pat. No. 5,882,494 (Van Antwerp). As described therein, the membrane material is simultaneously polymerized and crosslinked in a flask; the resulting polymeric material is dissolved in a strong organic solvent, such as tetrahydroforan (THF); and the resulting solution is applied onto the sensing layer to form the membrane. Unfortunately, a very strong organic solvent, such as THF, can denature the enzyme in the sensing layer and also dissolve conductive ink materials as well as any plastic materials that may be part of the sensor. Further, since the polymerization and crosslinking reactions are completed in the reaction flask, no further bond-making reactions occur when the solution is applied to the sensing layer to form the membrane. As a result, the adhesion between the membrane layer and sensing layer may not be adequate.
In the published Patent Cooperation Treaty (PCT) Application bearing. International Publication No. WO 01/57241 A2, Kelly and Schiffer describe a method for making a glucose-diffusion-limiting membrane by photolytically polymerizing small hydrophilic monomers. The sensitivities of the glucose sensors employing such membranes are widely scattered, however, indicating a lack of control in the membrane-making process. Further, as the polymerization involves very small molecules, it is quite possible that small, soluble molecules remain after polymerization, which may leach out of the sensor. Thus, glucose sensors employing such glucose-diffusion-limiting membranes may not be suitable for implantation in a living body.
SUMMARY OF THE INVENTION
The present invention is directed to membranes composed of crosslinked polymers containing heterocyclic nitrogen groups, particularly polymers of polyvinylpyridine and polyvinylimidazole, and to electrochemical sensors equipped with such membranes. The membranes are useful in limiting the flux of an analyte to a working electrode in an electrochemical sensor so that the sensor is linearly responsive over a large range of analyte concentrations and is easily calibrated. Electrochemical sensors equipped with membranes of the present invention demonstrate considerable sensitivity and stability, and a large signal-to-noise ratio, in a variety of conditions.
According to one aspect of the invention, the membrane is formed by crosslinking in situ a polymer, modified with a zwitterionic moiety, a non-pyridine copolymer component, and optionally another moiety that is either hydrophilic or hydrophobic, and/or has other desirable properties, in an alcohol-buffer solution. The modified polymer is made from a precursor polymer containing heterocyclic nitrogen groups. Preferably, the precursor polymer is polyvinylpyridine or polyvinylimidazole. When used in an electrochemical sensor, the membrane limits the flux of an analyte reaching a sensing layer of the sensor, such as an enzyme-containing sensing layer of a “wired enzyme” electrode, and further protects the sensing layer. These qualities of the membrane significantly extend the linear detection range and the stability of the sensor.
In the membrane formation process, the non-pyridine copolymer component generally enhances the solubility of the polymer and may provide further desirable physical or chemical properties to the polymer or the resulting membrane. Optionally, hydrophilic or hydrophobic modifiers may be used to “fine-tune” the permeability of the resulting membrane to an analyte of interest. Optional hydrophilic modifiers, such as poly(ethylene glycol), hydroxyl or polyhydroxyl modifiers, may be used to enhance the biocompatibility of the polymer or the resulting membrane. In the formation of a membrane of the present invention, the zwitterionic moiety of the polymer is believed to provide an additional layer of crosslinking, via intermolecular electrostatic bonds, beyond the basic crosslinking generally attributed to covalent bonds, and is thus believed to strengthen the membrane.
Another aspect of the invention concerns the preparation of a substantially homogeneous, analyte-diffusion-limiting membrane that may be used in a biosensor, such as an implantable amperometric biosensor. The membrane is formed in situ by applying an alcohol-buffer solution of a crosslinker and a modified polymer over an enzyme-containing sensing layer and allowing the solution to cure for one to two days. The crosslinker-polymer solution may be applied to the sensing layer by placing a droplet or droplets of the solution on the sensor, by dipping the sensor into the solution, or the like. Generally, the thickness of the membrane is controlled by the concentration of the solution, by the number of droplets of the solution applied, by the number of times the sensor is dipped in the solution, or by any combination of the these factors. Amperometric glucose sensors equipped with diffusion-limiting membranes of the present invention demonstrate excellent stability and fast and linear responsivity to glucose concentration over a large glucose concentration range.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of a typical structure of a section of an analyte-diffusion-limiting membrane, according to the present invention.
FIG. 2A is a schematic, side-view illustration of a portion of a two-electrode glucose sensor having a working electrode, a combined counter/reference electrode, and a dip-coated membrane that encapsulates both electrodes, according to the present invention. FIGS. 2B and 2C are schematic top- and bottom-view illustrations, respectively, of the portion of the glucose sensor of FIG. 2A . Herein, FIGS. 2A , 2 B and 2 C may be collectively referred to as FIG. 2 .
FIG. 3 is a graph of current versus glucose concentration for sensors having glucose-diffusion-limiting membranes, according to the present invention, and for sensors lacking such membranes, based on average values.
FIG. 4 is a graph of current output versus time at fixed glucose concentration for a sensor having a glucose-diffusion-limiting membrane, according to the present invention, and for a sensor lacking such a membrane.
FIG. 5 is a graph of current output versus time at different levels of glucose concentration for sensors having glucose-diffusion-limiting membranes, according to the present invention, based on average values.
FIG. 6 is a graph of current output versus time at different levels of glucose concentration, with and without stirring, for a sensor having a glucose-diffusion-limiting membrane, according to the present invention, and for a sensor lacking such a membrane.
FIG. 7A is a graph of current output versus glucose concentration for four separately prepared batches of sensors having glucose-diffusion-limiting membranes, according to the present invention, based on average values. FIGS. 7B-7E are graphs of current output versus glucose concentration for individual sensors in each of the four above-referenced batches of sensors having glucose-diffusion-limiting membranes, respectively, according to the present invention. Herein, FIGS. 7A , 7 B, 7 C, 7 D and 7 E may be collectively referred to as FIG. 7 .
DESCRIPTION OF THE INVENTION
When used herein, the terms in quotation marks are defined as set forth below.
The term “alkyl” includes linear or branched, saturated aliphatic hydrocarbons. Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl and the like. Unless otherwise noted, the term “alkyl” includes both alkyl and cycloalkyl groups.
The term “alkoxy” describes an alkyl group joined to the remainder of the structure by an oxygen atom. Examples of alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, butoxy, tert-butoxy, and the like. In addition, unless otherwise noted, the term ‘alkoxy’ includes both alkoxy and cycloalkoxy groups.
The term “alkenyl” describes an unsaturated, linear or branched aliphatic hydrocarbon having at least one carbon-carbon double bond. Examples of alkenyl groups include ethenyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-methyl-1-propenyl, and the like.
A “reactive group” is a functional group of a molecule that is capable of reacting with another compound to couple at least a portion of that other compound to the molecule. Reactive groups include carboxy, activated ester, sulfonyl halide, sulfonate ester, isocyanate, isothiocyanate, epoxide, aziridine, halide, aldehyde, ketone, amine, acrylamide, thiol, acyl azide, acyl halide, hydrazine, hydroxylamine, alkyl halide, imidazole, pyridine, phenol, alkyl sulfonate, halotriazine, imido ester, maleimide, hydrazide, hydroxy, and photo-reactive azido aryl groups. Activated esters, as understood in the art, generally include esters of succinimidyl, benzotriazolyl, or aryl substituted by electron-withdrawing groups such as sulfo, nitro, cyano, or halo groups; or carboxylic acids activated by carbodiimides.
A “substituted” functional group (e.g., substituted alkyl, alkenyl, or alkoxy group) includes at least one substituent selected from the following: halogen, alkoxy, mercapto, aryl, alkoxycarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, —OH, —NH2, alkylamino, dialkylamino, trialkylammonium, alkanoylamino, arylcarboxamido, hydrazino, alkylthio, alkenyl, and reactive groups.
A “crosslinker” is a molecule that contains at least two reactive groups capable of linking at least two molecules together, or linking at least two portions of the same molecule together. Linking of at least two molecules is called intermolecular crosslinking, while linking of at least two portions of the same molecule is called intramolecular crosslinking. A crosslinker having more than two reactive groups may be capable of both intermolecular and intramolecular crosslinkings at the same time.
The term “precursor polymer” refers to the starting polymer before the various modifier groups are attached to form a modified polymer.
The term “heterocyclic nitrogen group” refers to a cyclic structure containing a sp 2 hybridized nitrogen in a ring of the structure.
The term “polyvinylpyridine” refers to poly(4-vinylpyridine), poly(3-vinylpyridine), or poly(2-vinylpyridine), as well as any copolymer of vinylpyridine and a second or a third copolymer component.
The term “polyvinylimidazole” refers to poly(1-vinylimidazole), poly(2-vinylimidazole), or poly(4-vinylimidazole).
A “membrane solution” is a solution that contains all necessary components for crosslinking and forming the membrane, including a modified polymer containing heterocyclic nitrogen groups, a crosslinker and a buffer or an alcohol-buffer mixed solvent.
A “biological fluid” or “biofluid” is any body fluid or body fluid derivative in which the analyte can be measured, for example, blood, interstitial fluid, plasma, dermal fluid, sweat, and tears.
An “electrochemical sensor” is a device configured to detect the presence of or measure the concentration or amount of an analyte in a sample via electrochemical oxidation or reduction reactions. Typically, these reactions can be transduced to an electrical signal that can be correlated to an amount or concentration of analyte.
A “redox mediator” is an electron-transfer agent for carrying electrons between an analyte, an analyte-reduced or analyte-oxidized enzyme, and an electrode, either directly, or via one or more additional electron-transfer agents. A redox mediator that includes a polymeric backbone may also be referred to as a “redox polymer”.
The term “reference electrode” includes both a) reference electrodes and b) reference electrodes that also function as counter electrodes (i.e., counter/reference electrodes), unless otherwise indicated.
The term “counter electrode” includes both a) counter electrodes and b) counter electrodes that also function as reference electrodes (i.e., counter/reference electrodes), unless otherwise indicated.
In general, membrane of the present invention is formed by crosslinking a modified polymer containing heterocyclic nitrogen groups in an alcohol-buffer mixed solvent and allowing the membrane solution to cure over time. The polymer comprises poly(heterocyclic nitrogen-containing constituent) as a portion of its backbone and additional elements, including a zwitterionic moiety, a hydrophobic moiety, and optionally, a biocompatible moiety. The resulting membrane is capable of limiting the flux of an analyte from one space, such as a space associated with a biofluid, to another space, such as space associated with an enzyme-containing sensing layer. An amperometric glucose sensor constructed of a wired-enzyme sensing layer and a glucose-diffusion-limiting layer of the present invention is very stable and has a large linear detection range.
Heterocyclic-Nitrogen Containing Polymers
The polymer of the present invention has the following general formula, Formula 1a:
wherein the horizontal line represents a polymer backbone; A is an alkyl group substituted with a water soluble group, preferably a negatively charged group, such as sulfonate, phosphate, or carboxylate, and more preferably, a strong acid group such as sulfonate, so that the quaternized heterocyclic nitrogen to which it is attached is zwitterionic; D is a copolymer component of the polymer, as further described below; each of n, l, and p is independently an average number of an associated polymer unit or polymer units shown in the closest parentheses to the left; and q is a number of a polymer unit or polymer units shown in the brackets.
The heterocyclic nitrogen groups of Formula 1a include, but are not limited to, pyridine, imidazole, oxazole, thiazole, pyrazole, or any derivative thereof. Preferably, the heterocyclic nitrogen groups are independently vinylpyridine, such as 2-, 3-, or 4-vinylpyridine, or vinylimidazole, such as 1-, 2-, or 4-vinylimidazole. More preferably, the heterocyclic nitrogen groups are independently 4-vinylpyridine, such that the more preferable polymer is a derivative of poly(4-vinylpyridine). An example of such a poly(4-vinylpyridine) of the present invention has the following general formula, Formula 1b:
wherein A, D, n, l, p and q are as described above in relation to Formula 1a.
While the polymer of the present invention has the general Formula 1a or Formula 1b above, it should be noted that when A is a strong acid, such as a stronger acid than carboxylic acid, the D component is optional, such that p may equal zero. Such a polymer of the present invention has the following general formula, Formula 1c:
wherein A is a strong acid and the heterocyclic nitrogen groups, n, l and q are all as described above. Sulfonate and fluorinated carboxylic acid are examples of suitably strong acids. It is believed that when A is a sufficiently strong acid, the heterocyclic nitrogen to which it is attached becomes zwitterionic and thus capable of forming intermolecular electrostatic bonds with the crosslinker during membrane formation. It is believed that these intermolecular electrostatic bonds provide another level of crosslinking, beyond the covalent bonds typical of crosslinking, and thus make the resulting membrane stronger. As a result, when A is a suitably strong acid, the D component, which is often a strengthening component such as styrene, may be omitted from the polymers of Formulas 1a and 1b above. When A is a weaker acid, such that the heterocyclic nitrogen is not zwitterionic or capable of forming intermolecular electrostatic bonds, the polymer of the present invention does include D, as shown in Formulas 1a and 1b above.
Examples of A include, but are not limited to, sulfopropyl, sulfobutyl, carboxypropyl, and carboxypentyl. In one embodiment of the invention, group A has the formula -L-G, where L is a C2-C12 linear or branched alkyl linker optionally and independently substituted with an aryl, alkoxy, alkenyl, alkynyl, —F, —Cl, —OH, aldehyde, ketone, ester, or amide group, and G is a negatively charged carboxy or sulfonate group. The alkyl portion of the substituents of L have 1-6 carbons and are preferably an aryl, —OH or amide group.
A can be attached to the heterocyclic nitrogen group via quaternization with an alkylating agent that contains a suitable linker L and a negatively charged group G, or a precursor group that can be converted to a negatively charged group G at a later stage. Examples of suitable alkylating agents include, but are not limited to, 2-bromoethanesulfonate, propanesultone, butanesultone, bromoacetic acid, 4-bromobutyric acid and 6-bromohexanoic acid. Examples of alkylating agents containing a precursor group include, but are not limited to, ethyl bromoacetate and methyl 6-bromohexanoate. The ethyl and methyl ester groups of these precursors can be readily converted to a negatively charged carboxy group by standard hydrolysis.
Alternatively, A can be attached to the heterocyclic nitrogen group by quaternizing the nitrogen with an alkylating agent that contains an additional reactive group, and subsequently coupling, via standard methods, this additional reactive group to another molecule that contains a negatively charged group G and a reactive group. Typically, one of the reactive groups is an electrophile and the other reactive group is a nucleophile. Selected examples of reactive groups and the linkages formed from their interactions are shown in Table 1.
TABLE 1 Examples of Reactive Groups and Resulting Linkages First Reactive Group Second Reactive Group Resulting Linkage Activated ester* Amine Amide Acrylamide Thiol Thioether Acyl azide Amine Amide Acyl halide Amine Amide Carboxylic acid Amine Amide Aldehyde or ketone Hydrazine Hydrazone Aldehyde or ketone Hydroxyamine Oxime Alkyl halide Amine Alkylamine Alkyl halide Carboxylic acid Ester Alkyl halide Imidazole Imidazolium Alkyl halide Pyridine Pyridinium Alkyl halide Alcohol/phenol Ether Alkyl halide Thiol Thioether Alkyl sulfonate Thiol Thioether Alkyl sulfonate Pyridine Pyridinium Alkyl sulfonate Imidazole Imidazolium Alkyl sulfonate Alcohol/phenol Ether Anhydride Alcohol/phenol Ester Anhydride Amine Amide Aziridine Thiol Thioether Aziridine Amine Alkylamine Aziridine Pyridine Pyridinium Epoxide Thiol Thioether Epoxide Amine Alkylamine Epoxide Pyridine Pyridinium Halotriazine Amine Aminotriazine Halotriazine Alcohol Triazinyl ether Imido ester Amine Amidine Isocyanate Amine Urea Isocyanate Alcohol Urethane Isothiocyanate Amine Thiourea Maleimide Thiol Thioether Sulfonyl halide Amine Sulfonamide *Activated esters, as understood in the art, generally include esters of succinimidyl, benzotriazolyl, or aryl substituted by electron-withdrawing groups such as sulfo, nitro, cyano, or halo; or carboxylic acids activated by carbodiimides.
By way of example, A may be attached to the heterocyclic nitrogen groups of the polymer by quaternizing the heterocyclic nitrogens with 6-bromohexanoic acid and subsequently coupling the carboxy group to the amine group of 3-amino-1-propanesulfonic acid in the presence of a carbodiimide coupling agent.
D is a component of a poly(heterocyclic nitrogen-co-D) polymer of Formula 1a or 1b. Examples of D include, but are not limited to, phenylalkyl, alkoxystyrene, hydroxyalkyl, alkoxyalkyl, alkoxycarbonylalkyl, and a molecule containing a poly(ethylene glycol) or polyhydroxyl group. Some poly(heterocyclic nitrogen-co-D) polymers suitable as starting materials for the present invention are commercially available. For example, poly(2-vinylpyridine-co-styrene), poly(4-vinylpyridine-co-styrene) and poly(4-vinylpyridine-co-butyl methacrylate) are available from Aldrich Chemical Company, Inc. Other poly(heterocyclic nitrogen-co-D) polymers can be readily synthesized by anyone skilled in the art of polymer chemistry using well-known methods. Preferably, D is a styrene or a C1-C18 alkyl methacrylate component of a polyvinylpyridine-poly-D, such as (4-vinylpyrine-co-styrene) or poly(4-vinylpyridine-co-butyl methacrylate), more preferably, the former. D may contribute to various desirable properties of the membrane including, but not limited to, hydrophobicity, hydrophilicity, solubility, biocompatibility, elasticity and strength. D may be selected to optimize or “fine-tune” a membrane made from the polymer in terms of its permeability to an analyte and its non-permeability to an undesirable, interfering component, for example.
The letters n, l, and p designate, respectively, an average number of each copolymer component in each polymer unit. The letter q is one for a block copolymer or a number greater than one for a copolymer with a number of repeating polymer units. By way of example, the q value for a polymer of the present invention may be ≧about 950, where n, l and p are 1, 8 and 1, respectively. The letter q is thus related to the overall molecular weight of the polymer. Preferably, the average molecular weight of the polymer is above about 50,000, more preferably above about 200,000, most preferably above about 1,000,000.
The polymer of the present invention may comprise a further, optional copolymer, as shown in the following general formula, Formula 2a:
wherein the polymer backbone, A, D, n, l, p and q are as described above in relation to Formulas 1a-1c; in is an average number of an associated polymer unit or polymer units shown in the closest parentheses to the left; and B is a modifier. When the heterocyclic nitrogen groups are 4-substituted pyridine, as is preferred, the polymer of the present invention is derivative of poly(4-vinylpyridine) and has the general formula, Formula 2b, set forth below.
Further, when A is a suitably strong acid, as described above, the D copolymer is optional, in which case the polymer of the present invention has the general formula, Formula 2c:
In any of Formulas 2a-2c, B is a modifier group that may add any desired chemical, physical or biological properties to the membrane. Such desired properties include analyte selectivity, hydrophobicity, hydrophilicity, elasticity, and biocompatibility. Examples of modifiers include the following: negatively charged molecules that may minimize entrance of negatively charged, interfering chemicals into the membrane; hydrophobic hydrocarbon molecules that may increase adhesion between the membrane and sensor substrate material; hydrophilic hydroxyl or polyhydroxy molecules that may help hydrate and add biocompatibility to the membrane; silicon polymers that may add elasticity and other properties to the membrane; and poly(ethylene glycol) constituents that are known to increase biocompatibility of biomaterials (Bergstrom, K., et al., J. Biomed. Mat. Res. 26, 779 (1992)). Further examples of B include, but are not limited to, a metal chelator, such as a calcium chelator, and other biocompatible materials. A poly(ethylene glycol) suitable for biocompatibility modification of the membrane generally has a molecular weight of from about 100 to about 20,000, preferably, from about 500 to about 10,000, and more preferably, from about 1,000 to about 8,000.
The modifier B can be attached to the heterocyclic nitrogens of the polymer directly or indirectly. In direct attachment, the heterocyclic nitrogen groups may be reacted with a modifier containing an alkylating group. Suitable alkylating groups include, but are not limited to, alkyl halide, epoxide, aziridine, and sulfonate esters. In indirect attachment, the heterocyclic nitrogens of the polymer may be quaternized with an alkylating agent having an additional reactive group, and then attached to a molecule having a desired property and a suitable reactive group.
As described above, the B-containing copolymer is optional in the membrane of the present invention, such that when m of Formula 2a-2c is zero, the membrane has the general formula of Formula 1a-1c, respectively. The relative amounts of the four copolymer components, the heterocyclic nitrogen group containing A, the optional heterocyclic nitrogen group containing B, the heterocyclic nitrogen group, and D, may be expressed as percentages, as follows: [n/(n+m+l+p)]×100%, [m/(n+m+l+p)]×100%, [l/(n+m+l+p)]×100%, and [p/(n+m+l+p)]×100%, respectively. Suitable percentages are 1-25%, 0-15% (when the B-containing heterocyclic nitrogen group is optional) or 1-15%, 20-90%, and 0-50% (when D is optional) or 1-50%, respectively, and preferable percentages are 5-20%, 0-10% (when the B-containing heterocyclic nitrogen group is optional) or 1-10%, 60-90%, and 5-20%, respectively.
Specific examples of suitable polymers have the general formulas, Formulas 3-6, shown below.
EXAMPLES OF SYNTHESES OF POLYVINYLPYRIDINE POLYMERS
Examples showing the syntheses of various polyvinylpyridine polymers according to the present invention are provided below. Numerical figures provided are approximate.
Example 1
Synthesis of a Polymer of Formula 3
By way of illustration, an example of the synthesis of a polymer of Formula 3 above, is now provided. A solution of poly(4-vinylpyridine-co-styrene) (˜10% styrene content) (20 g, Aldrich) in 100 mL of dimethyl formamide (DMF) at 90° C. was stirred and 6-bromohexanoic acid (3.7 g) in 15-20 mL of DMF was added. The resulting solution was stirred at 90° C. for 24 hours and then poured into 1.5 L of ether, whereupon the solvent was decanted. The remaining, gummy solid was dissolved in MeOH (150-200 mL) and suction-filtered through a medium-pore, fitted funnel to remove any undissolved solid. The filtrate was added slowly to rapidly stirred ether (1.5 L) in a beaker. The resulting precipitate was collected by suction filtration and dried at 50° C. under high vacuum for 2 days. The polymer had the following parameters: [n/(n+l+p)]×100%≈10%; [l/(n+l+p)]×100%≈80%; and [p/(n+l+p)]×100%≈10%.
Example 2
Synthesis of a Polymer of Formula 5
By way of illustration, an example of the synthesis of a polymer of Formula 5 above, is now provided. A solution of poly(4-vinylpyridine-co-styrene) (˜10% styrene) (20 g, Aldrich) in 100 mL of anhydrous DMF at 90° C. was stirred, methanesulfonic acid (˜80 mg) was added, and then 2 g of methoxy-PEG-epoxide (molecular weight 5,000) (Shearwater Polymers, Inc.) in 15-20 mL of anhydrous DMF was added. The solution was stirred at 90° C. for 24 hours and 1,3-Propane sultone (2.32 g) in 10 mL of anhydrous DMF was added. The resulting solution was continuously stirred at 90° for 24 hours, and then cooled to room temperature and poured into 800 mL of ether. The solvent was decanted and the remaining precipitate was dissolved in hot MeOH (˜200 mL), suction-filtered, precipitated again from 1 L of ether, and then dried at 50° C. under high vacuum for 48 hours. The resulting polymer has the following parameters: [n/(n+m+l+p)]×100%≈10%; [m/(n+m+l+p)]×100%≈10%; [l/(n+m+l+p)]×100%≈70%; and [p/(n+m+l+p)]×100%≈10%.
Example 3
Synthesis of a Polymer Having a Polyhydroxy Modifier B
By way of illustration, an example of the synthesis of a polymer having a polyhydroxy modifier B, as schematically illustrated below, is now provided. Various polyhydroxy compounds are known for having biocompatibility properties. (U.S. Pat. No. 6,011,077.) The synthesis below illustrates how a modifier group having a desired property may be attached to the polymer backbone via a linker.
1,3-propane sultone (0.58 g, 4.8 mmoles) and 6-bromohexanoic acid (1.85 g, 9.5 mmoles) are added to a solution of poly(4-vinylpyridine-co-styrene) (˜10% styrene) (10 g) dissolved in 60 mL of anhydrous DMF. The resulting solution is stirred at 90° C. for 24 hours and then cooled to room temperature. O—(N-succinimidyl)-N,N,N′,N′-tetramethyl-uronium tetrafluoroborate (TSTU) (2.86 g, 9.5 mmoles) and N,N-diisopropylethylamine (1.65 mL, 9.5 mmoles) are then added in succession to the solution. After the solution is stirred for 5 hours, N-methyl-D-glucamine (2.4 g, 12.4 mmoles) is added and the resulting solution is stirred at room temperature for 24 hours. The solution is poured into 500 ml of ether and the precipitate is collected by suction filtration. The collected precipitate is then dissolved in MeOH/H 2 O and the resulting solution is subjected to ultra membrane filtration using the same MeOH/H 2 O solvent to remove small molecules. The dialyzed solution is evaporated to dryness to give a polymer with the following parameters: [n/(n+m+l+p)]×100%≈10%; [m/(n+m+l+p)]×100%≈40%; [l/(n+m+l+p)]×100%≈70%; and [p/(n+m+l+p)]×100%≈10%.
Crosslinkers
Crosslinkers of the present invention are molecules having at least two reactive groups, such as bi-, tri-, or tetra-functional groups, capable of reacting with the heterocyclic nitrogen groups, pyridine groups, or other reactive groups contained on A, B or D of the polymer. Preferably, the reactive groups of the crosslinkers are slow-reacting alkylating groups that can quaternize the heterocyclic nitrogen groups, such as pyridine groups, of the polymer. Suitable alkylating groups include, but are not limited to, derivatives of poly(ethylene glycol) or poly(propylene glycol), epoxide (glycidyl group), aziridine, alkyl halide, and sulfonate esters. Alkylating groups of the crosslinkers are preferably glycidyl groups. Preferably, glycidyl crosslinkers have a molecular weight of from about 200 to about 2,000 and are water soluble or soluble in a water-miscible solvent, such as an alcohol. Examples of suitable crosslinkers include, but are not limited to, poly(ethylene glycol) diglycidyl ether with a molecular weight of about 200 to about 600, and N,N-diglycidyl-4-glycidyloxyaniline.
It is desirable to have a slow crosslinking reaction during the dispensing of membrane solution so that the membrane coating solution has a reasonable pot-life for large-scale manufacture. A fast crosslinking reaction results in a coating solution of rapidly changing viscosity, which renders coating difficult. Ideally, the crosslinking reaction is slow during the dispensing of the membrane solution, and accelerated during the curing of the membrane at ambient temperature, or at an elevated temperature where possible.
Membrane Formation and Sensor Fabrication
An example of a process for producing a membrane of the present invention is now described. In this example, the polymer of the present invention and a suitable crosslinker are dissolved in a buffer-containing solvent, typically a buffer-alcohol mixed solvent, to produce a membrane solution. Preferably, the buffer has a pH of about 7.5 to about 9.5 and the alcohol is ethanol. More preferably, the buffer is a 10 mM (2-(4-(2-hydroxyethyl)-1-piperazine)ethanesulfonate) (HEPES) buffer (pH 8) and the ethanol to buffer volume ratio is from about 95 to 5 to about 0 to 100. A minimum amount of buffer is necessary for the crosslinking chemistry, especially if an epoxide or aziridine crosslinker is used. The amount of solvent needed to dissolve the polymer and the crosslinker may vary depending on the nature of the polymer and the crosslinker. For example, a higher percentage of alcohol may be required to dissolve a relatively hydrophobic polymer and/or crosslinker.
The ratio of polymer to cross-linker is important to the nature of the final membrane. By way of example, if an inadequate amount of crosslinker or an extremely large excess of crosslinker is used, crosslinking is insufficient and the membrane is weak. Further, if a more than adequate amount of crosslinker is used, the membrane is overly crosslinked such that membrane is too brittle and/or impedes analyte diffusion. Thus, there is an optimal ratio of a given polymer to a given crosslinker that should be used to prepare a desirable or useful membrane. By way of example, the optimal polymer to crosslinker ratio by weight is typically from about 4:1 to about 32:1 for a polymer of any of Formulas 3-6 above and a poly(ethylene glycol) diglycidyl ether crosslinker, having a molecular weight of about 200 to about 400. Most preferably, this range is from about 8:1 to about 16:1. Further by way of example, the optimal polymer to crosslinker ratio by weight is typically about 16:1 for a polymer of Formula 4 above, wherein [n/(n+l+p)]×100%≈10%, [l/(n+l+p)]×100%≈80%, and [p/(n+l+p)]×100%≈10%, or for a polymer of Formula 5 above, wherein [n/(n+m+l+p)]×100%≈10%, [m/(n+m+l+p)]×100%≈10%, [l/(n+m+l+p)]×100%≈70%, [p/(n+m+l+p)]×100%≈10%, and r≈110, and a poly(ethylene glycol) diglycidyl ether crosslinker having a molecular weight of about 200.
The membrane solution can be coated over a variety of biosensors that may benefit from having a membrane disposed over the enzyme-containing sensing layer. Examples of such biosensors include, but are not limited to, glucose sensors and lactate sensors. (See U.S. Pat. No. 6,134,461 to Heller et al., which is incorporated herein in its entirety by this reference.) The coating process may comprise any commonly used technique, such as spin-coating, dip-coating, or dispensing droplets of the membrane solution over the sensing layers, and the like, followed by curing under ambient conditions typically for 1 to 2 days. The particular details of the coating process (such as dip duration, dip frequency, number of dips, or the like) may vary depending on the nature (i.e., viscosity, concentration, composition, or the like) of the polymer, the crosslinker, the membrane solution, the solvent, and the buffer, for example. Conventional equipment may be used for the coating process, such as a DSG D1L-160 dip-coating or casting system of NIMA Technology in the United Kingdom.
Example of Sensor Fabrication
Sensor fabrication typically consists of depositing an enzyme-containing sensing layer over a working electrode and casting the diffusion-limiting membrane layer over the sensing layer, and optionally, but preferably, also over the counter and reference electrodes. The procedure below concerns the fabrication of a two-electrode sensor, such as that depicted in FIGS. 2A-2C . Sensors having other configurations such as a three-electrode design can be prepared using similar methods.
A particular example of sensor fabrication, wherein the numerical figures are approximate, is now provided. A sensing layer solution was prepared from a 7.5 mM HEPES solution (0.5 μL, pH 8), containing 1.7 μg of the polymeric osmium mediator compound L, as disclosed in Published Patent Cooperation Treaty (PCT) Application, International Publication No. WO 01/36660 A2, which is incorporated herein in its entirety by this reference; 2.1 μg of glucose oxidase (Toyobo); and 1.3 μg of poly(ethylene glycol) diglycidyl ether (molecular weight 400). Compound L is shown below.
The sensing layer solution was deposited over carbon-ink working electrodes and cured at room temperature for two days to produce a number of sensors. A membrane solution was prepared by mixing 4 volumes of a polymer of Formula 4 above, dissolved at 64 mg/mL in 80% EtOH/20% HEPES buffer (10 mM, pH 8), and one volume of poly(ethylene glycol) diglycidyl ether (molecular weight 200), dissolved at 4 mg/mL in 80% EtOH/20% HEPES buffer (10 mM, pH 8). The above-described sensors were dipped three times into the membrane solution, at about 5 seconds per dipping, with about a 10-minute time interval between consecutive dippings. The sensors were then cured at room temperature and normal humidity for 24 hours.
An approximate chemical structure of a section of a typical membrane prepared according to the present invention is shown in FIG. 1 . Such a membrane may be employed in a variety of sensors, such as the two- or three-electrode sensors described previously herein. By way of example, the membrane may be used in a two-electrode amperometric glucose sensor, as shown in FIG. 2A-2C (collectively FIG. 2 ) and described below.
The amperometric glucose sensor 10 of FIG. 2 comprises a substrate 12 disposed between a working electrode 14 that is typically carbon-based, and a Ag/AgCl counter/reference electrode 16 . A sensor or sensing layer 18 is disposed on the working electrode. A membrane or membrane layer 20 encapsulates the entire glucose sensor 10 , including the Ag/AgCl counter/reference electrode.
The sensing layer 18 of the glucose sensor 10 consists of crosslinked glucose oxidase and a low potential polymeric osmium complex mediator, as disclosed in the above-mentioned Published PCT Application, International Publication No. WO 01/36660 A2. The enzyme- and mediator-containing formulation that can be used in the sensing layer, and methods for applying them to an electrode system, are known in the art, for example, from U.S. Pat. No. 6,134,461. According to the present invention, the membrane overcoat was formed by thrice dipping the sensor into a membrane solution comprising 4 mg/mL poly(ethylene glycol) diglycidyl ether (molecular weight of about 200) and 64 mg/mL of a polymer of Formula 4 above, wherein [n/(n+l+p)]×100%≈10%; [l/(n+l+p)]×100%≈80%; and [p/(n+l+p)]×100%≈10%, and curing the thrice-dipped sensor at ambient temperature and normal humidity for at least 24 hours, such as for about 1 to 2 days. The q value for such a membrane overcoat may be ≧about 950, where n, l and p are 1, 8 and 1, respectively.
Membrane Surface Modification
Polymers of the present invention have a large number of heterocyclic nitrogen groups, such as pyridine groups, only a few percent of which are used in crosslinking during membrane formation. The membrane thus has an excess of these groups present both within the membrane matrix and on the membrane surface. Optionally, the membrane can be further modified by placing another layer of material over the heterocyclic-nitrogen-group-rich or pyridine-rich membrane surface. For example, the membrane surface may be modified by adding a layer of poly(ethylene glycol) for enhanced biocompatibility. In general, modification may consist of coating the membrane surface with a modifying solution, such as a solution comprising desired molecules having an alkylating reactive group, and then washing the coating solution with a suitable solvent to remove excess molecules. This modification should result in a monolayer of desired molecules.
The membrane 20 of the glucose sensor 10 shown in FIG. 2 may be modified in the manner described above.
Experimental Examples
Examples of experiments that demonstrate the properties and/or the efficacy of sensors having diffusion-limiting membranes according to the present invention are provided below, Numerical figures provided are approximate.
Calibration Experiment
In a first example, a calibration experiment was conducted in which fifteen sensors lacking membranes were tested simultaneously (Set 1), and separately, eight sensors having diffusion-limiting membranes according to the present invention were tested simultaneously (Set 2), all at 37° C. In Set 2, the membranes were prepared from polymers of Formula 4 above and poly(ethylene glycol) diglycidyl ether (PEGDGE) crosslinkers, having a molecular weight of about 200. In the calibration experiment for each of Set 1 and Set 2, the sensors were placed in a PBS-buffered solution (pH 7) and the output current of each of the sensors was measured as the glucose concentration was increased. The measured output currents (μA for Set 1; nA for Set 2) were then averaged for each of Set 1 and Set 2 and plotted against glucose concentration (mM), as shown in the calibration graph of FIG. 3 .
As shown, the calibration curve for the Set 1 sensors lacking membranes is approximately linear over a very small range of glucose concentrations, from zero to about 3 mM, or 5 mM at most. This result indicates that the membrane-free sensors are insufficiently sensitive to glucose concentration change at elevated glucose concentrations such as 10 mM, which is well below the high end of clinically relevant glucose concentration at about 30 mM. By contrast, the calibration curve for the Set 2 sensors having diffusion-limiting membranes according to the present invention is substantially linear over a relatively large range of glucose concentrations, for example, from zero to about 30 mM, as demonstrated by the best-fit line (y=1.2502x+1.1951; R 2 ≈0.997) also shown in FIG. 3 . This result demonstrates the considerable sensitivity of the membrane-equipped membranes to glucose concentration, at low, medium, and high glucose concentrations, and of particular relevance, at the high end of clinically relevant glucose concentration at about 30 mM.
Stability Experiment
In a second example, a stability experiment was conducted in which a sensor lacking a membrane and a sensor having a diffusion-limiting membrane according to the present invention were tested, simultaneously, at 37° C. The membrane-equipped sensor had a membrane prepared from the same polymer and the same crosslinker as those of the sensors of Set 2 described above in the calibration experiment. In this stability experiment, each of the sensors was placed in a PBS-buffered solution (pH 7) having a fixed glucose concentration of 30 mM, and the output current of each of the sensors was measured. The measured output currents (μA for the membrane-less sensor; nA for the membrane-equipped sensor) were plotted against time (hour), as shown in the stability graph of FIG. 4 .
As shown, the stability curve for the membrane-less sensor decays rapidly over time, at a decay rate of about 4.69% μA per hour. This result indicates a lack of stability in the membrane-less sensor. By contrast, the stability curve for the membrane-equipped sensor according to the present invention shows relative constancy over time, or no appreciable decay over time, the decay rate being only about 0.06% nA per hour. This result demonstrates the considerable stability and reliability of the membrane-equipped sensors of the present invention. That is, at a glucose concentration of 30 mM, while the membrane-less sensor lost sensitivity at a rate of almost 5% per hour over a period of about 20 hours, the membrane-equipped sensor according to the present invention showed virtually no loss of sensitivity over the same period.
Responsivity Experiment
Ideally, the membrane of an electrochemical sensor should not impede communication between the sensing layer of the sensor and fluid or biofluid containing the analyte of interest. That is, the membrane should respond rapidly to changes in analyte concentration.
In a third example, a responsivity experiment was conducted in which eight sensors having diffusion-limiting membranes according to the present invention were tested simultaneously (Set 3), all at 37° C. The sensors of Set 3 had membranes prepared from the same polymers and the same crosslinkers as those of the sensors of Set 2 described in the calibration experiment above. In this responsivity experiment, the eight sensors were placed in a PBS-buffered solution (pH 7), the glucose concentration of which was increased in a step-wise manner over time, as illustrated by the glucose concentrations shown in FIG. 5 , and the output current of each of the sensors was measured. The measured output currents (nA) were then averaged for Set 3 and plotted against time (real time, hour:minute:second), as shown in the responsivity graph of FIG. 5 .
The responsivity curve for the Set 3 sensors having diffusion-limiting membranes according to the present invention has discrete steps that mimic the step-wise increases in glucose concentration in a rapid fashion. As shown, the output current jumps rapidly from one plateau to the next after the glucose concentration is increased. This result demonstrates the considerable responsivity of the membrane-equipped sensors of the present invention. The responsivity of these membrane-equipped electrochemical sensors makes them ideal for analyte sensing, such as glucose sensing.
Motion-Sensitivity Experiment
Ideally, the membrane of an electrochemical sensor should be unaffected by motion or movement of fluid or biofluid containing the analyte of interest. This is particularly important for a sensor that is implanted in a body, such as a human body, as body movement may cause motion-associated noise and may well be quite frequent.
In this fourth example, a motion-sensitivity experiment was conducted in which a sensor A lacking a membrane was tested, and separately, a sensor B having a diffusion-limiting membrane according to the present invention was tested, all at 37° C. Sensor B had a membrane prepared from the same polymer and the same crosslinker as those of the sensors of Set 2 described in the calibration experiment above. In this experiment, for each of test, the sensor was placed in a beaker containing a PBS-buffered solution (pH 7) and a magnetic stirrer. The glucose concentration of the solution was increased in a step-wise manner over time, in much the same manner as described in the responsivity experiment above, as indicated by the various mM labels in FIG. 6 . The stirrer was activated during each step-wise increase in the glucose concentration and deactivated some time thereafter, as illustrated by the “stir on” and “stir off” labels shown in FIG. 6 . This activation and deactivation of the stirrer was repeated in a cyclical manner at several levels of glucose concentration and the output current of each of the sensors was measured throughout the experiment. The measured output currents (μA for sensor A; nA for sensor B) were plotted against time (minute), as shown in the motion-sensitivity graph of FIG. 6 .
As shown, the output current for the membrane-less sensor A is greatly affected by the stir versus no stir conditions over the glucose concentration range used in the experiment. By contrast, the output current for sensor. B, having diffusion-limiting membranes according to the present invention, is virtually unaffected by the stir versus no stir conditions up to a glucose concentration of about 10 mM, and only slightly affected by these conditions at a glucose concentration of about 15 mM. This result demonstrates the considerable stability of the membrane-equipped sensors of the present invention in both stirred and non-stirred environments. The stability of these membrane-equipped electrochemical sensors in an environment of fluid movement makes them ideal for analyte sensing within a moving body.
Sensor Reproducibility Experiment
Dip-coating, or casting, of membranes is typically carried out using dipping machines, such as a DSG D1L-160 of NIMA Technology of the United Kingdom. Reproducible casting of membranes has been considered quite difficult to achieve. (Chen, T., et al., In Situ Assembled Mass - Transport Controlling Micromembranes and Their Application in Implanted Amperometric Glucose Sensors , Anal. Chem., Vol. 72, No. 16, Pp. 3757-3763 (2000).) Surprisingly, sensors of the present invention can be made quite reproducibly, as demonstrated in the experiment now described.
Four batches of sensors (Batches 1-4) were prepared separately according to the present invention, by dipping the sensors in membrane solution three times using casting equipment and allowing them to cure. In each of the four batches, the membrane solutions were prepared from the polymer of Formula 4 and poly(ethylene glycol) digycidyl ether (PEDGE) crosslinker having a molecular weight of about 200 (as in Set 2 and other Sets described above) using the same procedure. The membrane solutions for Batches 1 and 2 were prepared separately from each other, and from the membrane solution used for Batches 3 and 4. The membrane solution for Batches 3 and 4 was the same, although the Batch 3 and Batch 4 sensors were dip-coated at different times using different casting equipment. That is, Batches 1, 2 and 3 were dip-coated using a non-commercial, built system and Batch 4 was dip-coated using the above-referenced DSG D1L-160 system.
Calibration tests were conducted on each batch of sensors at 37° C. For each batch, the sensors were placed in PBS-buffered solution (pH 7) and the output current (nA) of each of the sensors was measured as the glucose concentration (mM) was increased. For each sensor in each of the four batches, a calibration curve based on a plot of the current output versus glucose concentration was prepared as shown in FIG. 7B (Batch 1: 5 sensors), FIG. 7C (Batch 2: 8 sensors), FIG. 7D (Batch 3: 4 sensors) and FIG. 7E (Batch 4: 4 sensors). The average slopes of the calibration curves for each batch were the following:
Average Slope=1.10 nA/mM(CV=5%); Batch 1:
Average Slope=1.27 nA/mM(CV=10%); Batch 2:
Average Slope=1.15 nA/mM(CV=5%); and Batch 3:
Average Slope=1.14 nA/mM(CV=7%). Batch 4:
Further, for each batch, the current output for the sensors in the batch was averaged and plotted against glucose concentration, as shown in FIG. 7A . The average slope for Batches 1-4 was 1.17 nA/mM (CV=7.2%).
The slopes of the curves within each batch and from batch-to-batch are very tightly grouped, showing considerably little variation. The results demonstrate that sensors prepared according to the present invention give quite reproducible results, both within a batch and from batch-to-batch.
The foregoing examples demonstrate many of the advantages of the membranes of the present invention and the sensors employing such membranes. Particular advantages of sensors employing the membranes of the present invention include sensitivity, stability, responsivity, motion-compatibility, ease of calibration, and ease and reproducibility of manufacture.
Various aspects and features of the present invention have been explained or described in relation to beliefs or theories, although it will be understood that the invention is not bound to any particular belief or theory. Various modifications, processes, as well as numerous structures to which the present invention may be applicable will be readily apparent to those of skill in the art to which the present invention is directed upon review of the specification. Although the various aspects and features of the present invention have been described with respect to various embodiments and specific examples herein, it will be understood that the invention is entitled to protection within the full scope of the appended claims. | Novel membranes comprising various polymers containing heterocyclic nitrogen groups are described. These membranes are usefully employed in electrochemical sensors, such as amperometric biosensors. More particularly, these membranes effectively regulate a flux of analyte to a measurement electrode in an electrochemical sensor, thereby improving the functioning of the electrochemical sensor over a significant range of analyte concentrations. Electrochemical sensors equipped with such membranes are also described. | 2 |
TECHNICAL FIELD
[0001] The present invention has to do with the features of a status LED indicator. More particularly, this invention describes a new and useful sleep-mode status indicator system for laptop computers.
BACKGROUND ART
[0002] Saving electrical power has been a very important goal ever since the birth of battery-operated portable devices. For example, for laptop computers, one efficient way is to apply battery power only to the parts of a device in use, and at the same time to withhold power from those parts of a device not in use. The early portable devices, however, had a simple ON/OFF arrangement in which full battery power was available for use when the devices were ON and the battery power was completely shut off when the devices were OFF. Information such as re-usable software programs and data saved in the semiconductor memories became lost once the devices were turned OFF. To use the programs and data again, additional power and time must be used to load them back into the semiconductor memories. Some later portable device used non-volatile semiconductor memories so that the saved information remains intact even when the devices were turned OFF; some other portable devices used stand-by power adapted to keep the memories refreshed when the devices were OFF.
[0003] Today's laptop computers have complicated circuitry because of their additional peripheral units such as floppy disk, hard disk, PCMCIA and CD drives. To efficiently manage the use of electrical power, arrangements have been devised to monitor various functions inside a laptop computer. The computer is intelligent enough to apply battery power only to internal circuits and sub-systems that are deemed ‘in use’ and at the same time to withhold power from those circuits and sub-systems that are deemed ‘idle’. Sometimes the power is not completely withheld from the ‘idle’ circuitry but the power supply is merely reduced due to its entry into a low power consumption mode. Either way, the power management arrangement inside the laptop computer maximizes the computer's power savings and lengthens the duration the laptop computer can operate using batteries.
[0004] The electrical state of the computer when the power management arrangement deprives or reduces electrical power supplied to the ‘idle’ circuitry and sub-systems is generally referred to as the sleep mode. During sleep mode, the arrangement further monitors the activities in the computer in order that power can be applied immediately when needed. One way a laptop computer enters into the sleep mode is through user inaction. For example, when there is no user key entry for a pre-determined duration, display circuitry and related-subsystems are then shut off, and relevant programs and data are saved. Another way is through user issuance of a sleep command, and another way is through the detection of battery charge below a set level.
[0005] To awaken the computer from sleep mode, a typical way is by pressing any key on the keyboard. In this manner, relevant programs and data need not be re-loaded from hard disk and power to an otherwise idle display is conserved.
[0006] A sleep-mode indicator typically identifies to users that the laptop computer is in sleep mode. One such indicator is a blinking LED (light emitting device) located on a computer housing for convenient observation. For example, a typical sleep-mode indicator for Apple Macintosh PowerBook® computers is a blinking LED indicator subjected to identical electrical energy pulses at about one second apart and for a duration of about 40 msecs. FIG. 1 is a waveform chart that illustrates the identical electrical pulses that generate a prior art sleep-mode indicator blinking effect for the laptop computers. In this chart, the LED is driven with 6 mA of current for 40 msecs once a second.
[0007] Unfortunately, the LED blinking effect resulting from a once a second, identical electrical energy pulses does not provide the best pattern that is visually appealing to the users. A better and more improved status LED indicator is needed. More particularly, a better and more improved sleep-mode indicator system is therefore needed and duly described herein.
SUMMARY OF THE INVENTION
[0008] Therefore, it is an aspect of the present invention to provide a better and more improved status LED indicator. It is another aspect of the invention to provide a sleep-mode indicator for an electronic device such as a laptop computer that the indicator generates a visually appealing blinking pattern to the users. It is another aspect of the present invention to provide a LED blinking pattern along with varied intensity that in combination mimics the rhythm of breathing. It is yet another aspect of the present invention to provide an electrical apparatus that generates a sleep-mode indicator blinking pattern based on a sinusoidal function using PWM (pulse width modulation) designs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] A better understanding of the present invention can be obtained by considering the following detailed description taken together with the accompanying drawings that illustrate preferred embodiments of the present invention in which:
[0010] [0010]FIG. 1 is a chart that illustrates the identical electrical pulses that generate a prior art sleep-mode indicator blinking effect for laptop computers.
[0011] [0011]FIG. 2 is a functional block diagram of the parts of a laptop computer generally pertaining to the power management function of the present invention.
[0012] [0012]FIG. 3 is a chart that illustrates a simplified view of the electrical pulses that energize the sleep-mode indicator system according to a preferred embodiment of the present invention; also, it is superimposed with a sinusoidal duty cycle function for the purpose of pulse width modulation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] With today's advances in technology, the design of specialized integrated circuits (e.g., micro-controllers) and programmable logic generally do not require the rendering of fully detailed circuit diagrams. The definition of electronic functionality and electrical waveforms allow computer design techniques to design the desired logic and circuits. Accordingly, portions of the present invention will be described primarily in terms of functionality to be implemented by a micro-controller and other associated electronic components. This functionality will be described in detail with the accompanying drawings. Those of ordinary skill in the art, once given the following descriptions of the various functions to be carried out by the present invention will be able to implement the necessary micro-controller structure and circuit waveforms in suitable technologies without undue experimentation.
[0014] Referring to FIG. 2, a simplified overview of a partial laptop computer system 10 that is related to the present invention is shown in functional block diagram format. While FIG. 2 is useful for providing an overall description of the sleep-mode indicator system of the present invention, a number of details of the system are not shown. As necessary for disclosure of the present invention, further detail is set forth with reference to other figures provided with this specification.
[0015] The partial laptop computer system 10 includes a CPU 15 , a micro-controller power manager (PMGR) 20 and a LED circuit 30 . The CPU 15 is electrically coupled to PMGR 20 via line 17 . The LED circuit 30 is electrically coupled to PMGR 20 via line 23 . The lines 17 and 23 each may represent a collection of electronic lines adapted to ensure the proper working of the laptop computer. The LED circuit 30 includes a LED (not shown here) and an associated circuit (not shown) for generating a sleep mode status indicator signal which may cause a LED blinking effect. Depending on the design, it is possible to incorporate the associated circuit for the LED blinking effect inside the PGMR 20 . The PMGR 20 is an intelligent assistant to the CPU 15 , wherein PMGR 20 may monitor the state of charge of battery, control the power usage of the various subsystems or may even interface to I/O devices such as a modem or a serial card. PGMR may consist of or be a portion of an ASIC.
[0016] The main processor for the laptop computer system 10 is the CPU 15 . During sleep mode, the CPU 15 may become inactive and enter into a low-power consumption mode. For example, to minimize power usage, power or the clock signal to the CPU 15 may be turned OFF or the clock frequency feeding to the CPU 15 might be reduced. Further, once the computer goes to sleep, the PMGR 20 takes over the bulk of the sleep mode processing tasks. One of the tasks PMGR 20 does at the start of the sleep mode is to immediately turn the LED circuit 30 ON. As a result, the LED circuit 30 generates and display a sleep mode status indicator signal so that the LED might be blinking on the housing of the laptop computer to indicate to users that this computer is now in sleep mode.
[0017] [0017]FIG. 3 is a chart that illustrates a simplified view of the electrical pulses that energize the sleep-mode indicator system according to a preferred embodiment of the present invention; also, it is superimposed with a sinusoidal duty cycle function for the purpose of pulse width modulation. In this manner, the present invention would be better appreciated and readily understood.
[0018] The electrical pulses as shown in FIG. 3 have varied pulse widths because of the operation of PWM, and their actual pulse widths depend on the associated sinusoidal duty cycle function. The PWM frequency used in this embodiment is 125 Hz. In fact, preferred frequencies include any frequency sufficiently greater than that can be effectively distinguished by the human eye. However, power consideration for portable devices further prefer PWM frequencies to range within, for example, 100-200 Hz. The peak current is 6 mA as demonstrated by the vertical axis on the left of the chart, and it remains the same as that in FIG. 1. The electrical pulses in FIG. 3 are simplified in that not all of the pulses are shown. A PWM frequency of 125 Hz in the present invention denotes one electrical pulse in a period of 8 msecs. The timing scale for FIG. 3 is chosen for the ease of comparison with FIG. 1, and therefore, only representative pulses are shown in the chart.
[0019] The human eye, a relatively slow sensory device, in effect integrates these pulses giving the sensation of changing intensity. It was determined through experiment that increasing the duty cycle according to a non-linear function gives the most pleasing visual effect while a simple linear ramp does not seem as natural. A preferred sinusoid duty cycle function is shown in FIG. 3. It is measured by the duty cycle axis on the right of the chart. It is a positively-biased sinusoid function having its maximum at about 25% duty cycle and its minimum at 0% duty cycle. This duty cycle indicates the percentage of a 8 msec period an electrical pulse is to stayed at its peak current level. For example, an electrical pulse 50 in the chart has its rising edge coinciding with the peak of the sinusoidal function at 25% duty cycle. Thus, pulse 50 has a pulse width of 2 msecs. In this manner, all electrical pulses for the LED circuit 30 have varied pulse widths in accordance with the values of sinusoidal function at the time of their occurrences. For clarity, the pulse widths of the pulses in FIG. 3 are expanded and are not drawn to scale.
[0020] The sinusoidal function of the present invention may further include a quiet period during which the function value remains at 0% duty cycle. The chart in FIG. 3 demonstrates the quiet period ranging from 1400 msecs to 1800 msecs. This quiet period conserves electrical power because during which no electrical pulses occur. Clearly, the longer the duration of the quiet period, the more power savings occur; however, a preferred period duration is about 0.4 second. In essence, the varying intensity of the electrical pulses in combination with a quiet period provides a preferred visual experience for users. Further, the blinking effect of the sleep-mode indicator in accordance with the present invention mimics the rhythm of breathing which is psychologically appealing and superior than the LED effect of the waveforms as shown in FIG. 1. Altogether, a preferred overall ‘breathing’ periodicity is about 1.8 seconds.
[0021] As mentioned earlier about FIG. 1, PMGR 20 is an intelligent assistant to the CPU 15 , and it may incorporate any PWM circuit that generates the waveforms disclosed in FIG. 3. Alternatively, the LED circuit 30 may include a micro-controller structured separately from the PMGR 20 . For example, such a micro-controller would include PIC12C508A (not shown). Again, the definition of electronic functionality and electrical waveforms allow typical computer design techniques to design the desired logic and circuits in the PMGR 20 . Broadly speaking, this status LED indicator may be a member of any electronic device that has a need for status indication, and it is clearly not limited singly to sleep mode status indication for laptop computers.
[0022] The foregoing description of preferred embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents. | A new and improved status LED indicator provides a pleasing visual appeal. An embodiment of the present invention includes a sleep-mode indicator for laptop computers. The LED indicator is energized by pulse-width modulated electrical pulses. The effect of these pulses on the indicator varies in intensity and mimics a rhythm typical of breathing. It is another aspect of the invention to provide an electrical apparatus that generates a sleep-mode indicator blinking pattern based on a sinusoidal function using PWM (pulse width modulation) designs. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
In the prior art devices rolls having rotatable, perforated or cellular structure outer elements with an internal system for creating a sub-atmospheric pressure or vacuum within this rotatable outer element, are used for various purposes; such as, dewatering a moving, moist web of paper; applying greater traction for pulling a moving web of paper, metal or other materials; and picking up web or transferring sheet, an operation required in conjunction with certain printing presses. To produce stationary vacuum zones inside the roll, a suitable chamber connected to an external pump or exhauster must be provided, and in order to control the area in which vacuum is applied, as well as to assure optimum operating efficiency of the vacuum system, sealing arrangements must be provided to close off the line of contact between the inside of the rotating, perforated shell of the roll and the internally mounted stationary chamber. Presently a known practice is to mount rectangularly shaped pieces of non-metallic material having a low coefficient of friction and good wear qualities in a U-shaped member in such a manner that it can be radially forced outwardly against the internal surface of the rotating shell by springs or an inflatable air pressure tube. Of necessity, operating clearances must be provided between the non-metallic sealing element and the channel of the U-shaped holder in which it is disposed. In many applications of vacuum rolls certain parts thereof are exposed to contaminating environments, such as acids, adhesives or the like. Also, solid materials can become deposited in the clearances between the seal element and the U-shaped holder so that continuous free movement of the seal element becomes very difficult to maintain as the seal element is forced past the solid materials that are accumulated. As a result, the seal will become locked in a depressed position corresponding to the least internal radius of the rotating shell, and if there is any eccentricity in the bore of the shell, a clearance will occur when the shell is rotated to any other position and leakage past the seal will occur. In some applications of vacuum rolls, this can cause a fluctuation of the desired internal subatmospheric pressure in the roll with consequential adverse effect on the required function of the roll. Further, continued contact of the sealing element with the roll surface prevents proper cleaning thereof and subjects the sealing element and/or rotating shell to possible corrosion. Such prior art deficiencies have been approached with the teachings of U.S. Pat. No. 3,802,961 of Grass et al with considerable success.
SUMMARY OF THE INVENTION
The present invention provides a new and improved construction of a sealing assembly to improve the useful life of devices of this type known heretofore.
Another advantage of the present invention resides in the provision of a seal assembly having a lower radial profile than the prior art devices of this type whereby less bulk is encountered in the manufacture, installation and operation of the sealing assembly.
It is an object of the present invention to provide an improved sealing assembly which may be selectively placed into sealing condition or retracted from sealing condition to improve the useful life of the assembly.
It is moreover an object of the present invention to extend the period between replacement and/or servicing of seal assemblies of this type.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view in perspective of a vacuum roll in which the seal assembly according to the present invention is incorporated;
FIG. 2 is a sectional view taken along line 2--2 of FIG. 1 to show details of the sealing assembly with the sealing element retracted to a non-sealing condition;
FIG. 3 is a section taken along line 3--3 in FIG. 2;
FIG. 4 is a view similar to FIG. 2 with the sealing element urged into sealing condition;
FIG. 5 shows an exploded fragmentary view in perspective of the sealing assembly of FIGS. 2-4 and
FIG. 6 shows a plan view of a plurality of the parts of the sealing assembly laid out for inspection.
DETAILED DESCRIPTION OF THE INVENTION
Referring now in detail to the drawings, and in particular to FIGS. 1-6, the novel sealing arrangement according to this invention is seen to be incorporated in a vacuum roll assembly 10 which includes a perforated rotating outer shell 12 and a stationary inner portion 14 on which support members 16 are secured. Within the interior of the vacuum roll assembly 10 separate vacuum chambers 18 and 20 may be formed between a plurality of sealing assemblies 22. Shell 12, for example, may be formed with a plurality of perforations 60 to transmit suction to the outer surface over which extends a wire screen 62.
Each sealing arrangement 22 comprises a longitudinally extending sealing element 24 adapted to be selectively urged into sealing condition or retracted from sealing condition with respect to the inner surface 26 of roll 12. The sealing element 24 may be made from a material having a low coefficient of friction, such as polyethylene. Sealing surface 28 of sealing element is arcuate and is complementary with inner surface 26 of roll 12. Sealing element 24 as seen in FIG. 2 includes a generally flat radially inner surface along which are disposed a pair of inflatable loading tubes 30 with a spacer member 32 therebetween and a generally flat spring unit such as a resilient plate or leaf 34 of spring material overlying tubes 30 and spacer member 32 and extending laterally beyond the expanse of tubes 30. While sealing element 24 and spacer member 32 are illustrated as separate members, they may be, and in actual practice, have been combined as one integral member. A clamping bar 36 or the like extends over plate 34 with a plurality of bolts 38 each of which extends radially through bar 36, plate 34, spacer 32 and in threaded engagement with sleeve 40. Sleeve 40 provides a stable assembly in that it has male threads which provide a secure connection to sealing element 24 and female threads which provide a secure clamping of the assembled parts of sealing assembly 22. Because of the use of threaded sleeves 40, there is no necessity for an elongate pressure plate or the formation of an elongate slot therefor in the sealing element as required in the construction in the cited U.S. Pat. No. 3,802,961. Consequently, the sealing element 24 of the present application is sturdier than its predecessor since less material is removed to accommodate sleeves 40.
Each support member 16 extends longitudinally of vacuum roll 10 is channel shaped and includes pair of spaced apart generally radially extending legs 42, 44 which are connected together by generally circumferentially extending bight portion 46, which is secured by bolts 48 to inner portion 14 of roll assembly 10. The leg 42 of each support member 16 is disposed over sealing assembly 22 with its radially outer edge in abutment against plate 34. It is noted that radially outer edge of leg 42 is rounded on one side to merge with a vertical edge to minimize resistance to deflection of plate 34. Leg 44 of each support member 16 is longer than leg 42, extends past opposite sides of plate 34, and is formed with a longitudinally extending groove 50 in which is secured a rest pad or bar 52 extending between plate 34 and sealing element 24 alongside one of the tubes 30 in space provided by spacer member 32. As seen in FIG. 2, opposite edges of plate 34 are resting on top of rest pad or bar 52 in the retracted condition of sealing element 24. At one end of inflatable tube 30 there is provided an air inlet-outlet port 54 equipped with a valve for optionally allowing inflation or deflation of tube 30. As seen in FIG. 3 port 54 extends through a cover plate 56.
In at least one installation actually in use, sealing element 24, which is formed as a molded member, is up to as much as 184 inches in length and in another installation it is about 231 inches in length and may be of other lengths as governed by the length of the roll assembly 10. Because sealing element 24 is so long, the spacer member 32, resilient plate 34 and clamping bar 36 may each be assembled together from separate pieces as illustrated in FIG. 6. To facilitate assembly of the various parts into sealing assembly 22, sealing element 24 is provided with a plurality of threaded sleeves 40; spacer member 32 which includes two pieces 32', 32" provided with through holes 33', 33" for alignment with some sleeves 40; resilient plate 34 which includes several pieces 34', 34", 34'", 34"" provided with slots 35', 35", 35'", 35"" and/or hole 37"" for alignment with some sleeves 40; and clamping bar 36 which includes two pieces 36', 36" provided with slots 39', 39"" or hole 41" for alignment with some sleeves 40. The slots 35', 35", 35'", 35"", 39', 39" are provided to allow for expansion or contraction of the various pieces due to flexure of the sealing assembly 22 under loaded conditions, for example. In assembling the various pieces to form sealing assembly 22 use of washer 43 over each slot 39' of clamping bar 36' and over slot 39" and hole 41" of clamping bar 36" would ensure against damage to the pieces from bolts 38.
OPERATION OF THE INVENTION
Prior to or after operation of the vacuum roll assembly 10 air is released from port 54 of tube 30 whereupon resilient plate 34 assumes the position in FIGS. 2 and 3 which holds sealing assembly 22 in retracted condition with sealing surface 28 of sealing element 24 away from the inner surface 26 of shell 12 so that chambers 18 and 20 are equalized in pressure. In this retracted condition of sealing assembly 22, deleterious materials on the inner surface 26 of shell 12 and also on sealing element 24 may be cleaned and removed. Also, because of the retractability of sealing assembly, any tendency of solidification between sealing element 24 with the inner surface 26 of shell 12 through drying of resinous products would be avoided.
To isolate chambers 18 and 20 from each other so that different pressures or vacuums may be imposed therein, it is necessary to urge sealing assembly 22 outwardly radially so that sealing surface 28 is in contact with inner surface 26 of shell 12; this condition is obtained by inflating tubes 30 by the introduction of compressed air through port 54. Upon introduction of sufficient air into tubes 30 sealing surface 28 of sealing elements 24 will assume the contact position with inner surface 26 of shell 12 as seen in FIG. 4 wherein chambers 18 and 20 are isolated from each other. It is seen that with tubes 30 inflated opposite edges of resilient plate 34 will be deflected or lifted off rest pads 52 by tubes 30 until further deflection of plate 34 is resisted by the radial outer edge of legs 42 support members 16 so that sealing element 24 is moved radially outwardly into sealing contact with shell 12. Deflection of plate 34 around legs 42 is facilitated by the rounded side of the outer edge. Deflection of plate 34 actually starts on opposite sides of clamping bar 36 as seen in FIG. 4. Upon placing sealing element 24 into contact with inner surface 26 of shell 12, shell 26 is ready for operation to rotate, for example, in the direction of arrow D.
From the foregoing description a new and improved sealing assembly is provided and disclosed for use in isolating pressure and/or vacuum chambers in roll devices.
It will be obvious to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown in the drawings and described in the specification. | Improvements in seal assembly for use in pressure or vacuum chambers or the like comprising a sealing element which may be selectively placed in sealing condition or retracted to a non-sealing condition, the sealing element having a sealing surface adapted to be urged into contact with a wall member and also a surface including portions against load members which may be loaded to urge the sealing surface into sealing condition or relaxed, and spring unit for continuously urging the sealing element away from sealing condition whereby the sealing element is in fact urged out of sealing condition when the load members are relaxed. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a non-provisional patent application related to U.S. Provisional Patent Application Nos. 60/744,325, titled “SYSTEM FOR AND METHOD OF REWARDING SELLERS OR SUPPLIERS OF GOODS OR SERVICES” and 60/857,618 titled “SYSTEM AND METHOD FOR ORGANIZING AND DISTRIBUTING AUDIO INFORMATION”. Further, it is related to U.S. Non-Provisional patent applications Ser. No. 11/469,719 titled “SYSTEM FOR AND METHOD OF VISUAL REPRESENTATION AND REVIEW OF MEDIA FILES”, Ser. No. 11/469,731 titled “DIRECT RESPONSE SYSTEM FOR AND METHOD OF SELLING PRODUCTS”, Ser. No. 11/469,737 titled “SYSTEM FOR AND METHOD OF STREAMLINING COMMUNICATIONS TO MEDIA STATIONS”, and Ser. No. 11/469,743 titled “ADVERTISING PLACEMENT SYSTEM AND METHOD”, Ser. No. ______ titled “SELLING KEYWORDS IN RADIO BROADCASTS”, Ser. No. ______ titled “BROKERING KEYWORDS IN RADIO BROADCASTS” and, Ser. No. ______ titled “SEARCH RESULTS POSITIONING BASED ON RADIO METRICS” all of which (e.g., both the provisional and non-provisional patent applications) are incorporated by reference in their entirety.
TECHNICAL FIELD
[0002] This patent document pertains generally to advertising, and more particularly, but not by way of limitation, to a system and method for generating advertisements for use in broadcast media.
BACKGROUND
[0003] Media stations, such as radio stations and television stations, typically devote a portion of broadcast time to advertisements. This advertisement broadcast time is sold to advertisers, frequently through advertising agencies, and the sold broadcast time generates revenue for the media station.
[0004] Advertisers use various marketing strategies to test and track advertisements to ensure that less effective advertisements are discontinued in favor of more effective advertising. Because of high production costs, advertisers may be limited to test marketing a small number of advertisements and hoping for the best. A system is needed to address these types of issues.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a block diagram of an advertisement production system in accordance with an example embodiment.
[0006] FIG. 2 is a data flow diagram of an advertisement product system in accordance with an example embodiment.
[0007] FIG. 3 is a flow diagram illustrating a method for creating an advertisement in accordance with an example embodiment.
[0008] FIG. 4 is a flow diagram illustrating a method for creating an advertisement in accordance with an example embodiment.
[0009] FIG. 5 is a flow diagram illustrating a method for creating an advertisement in accordance with an example embodiment.
[0010] FIG. 6 is a flow diagram illustrating a method for suggesting a modification to an advertisement in accordance with an example embodiment.
[0011] FIG. 7 is a flow diagram illustrating a method for presenting audio track options to a user in accordance with an example embodiment.
[0012] FIG. 8 is a graphical user-interface illustrating a script edit screen for creating or editing an advertisement in accordance with an example embodiment.
[0013] FIG. 9 is a graphical user-interface illustrating a script edit screen for editing script features in accordance with an example embodiment.
[0014] FIG. 10 is a graphical user-interface illustrating a script suggested revisions screen for suggesting revisions to a script in accordance with an example embodiment.
[0015] FIG. 11 is a graphical user-interface illustrating a search results screen for providing search results in accordance with an example embodiment.
[0016] FIG. 12 is a flow diagram illustrating a method for revising an advertisement in accordance with an example embodiment.
[0017] FIG. 13 illustrates a diagrammatic representation of a machine capable of performing the methods or implementing the systems/devices described herein.
DETAILED DESCRIPTION
[0018] In the following detailed description of example embodiments of the invention, reference is made to specific example embodiments of the invention by way of drawings and illustrations. These examples are described in sufficient detail to enable those skilled in the art to practice the invention, and serve to illustrate how the invention may be applied to various purposes or embodiments. Other embodiments of the invention exist and are within the scope of the invention, and logical, mechanical, electrical, and other changes may be made without departing from the subject or scope of the present invention. Features or limitations of various embodiments of the invention described herein, however essential to the example embodiments in which they are incorporated, do not limit other embodiments of the invention or the invention as a whole, and any reference to the invention, its elements, operation, and application do not limit the invention as a whole but serve only to define these example embodiments. The following detailed description does not, therefore, limit the scope of the invention, which is defined only by the appended claims.
[0019] For the purposes of clarity, in some cases, reference is made to a single object (e.g., machine, module, unit, or other component) in the included drawings. However, unless expressly designated, a reference to an object is not to be construed as a being limited to a singular instance of the object, but rather that at least one object may be included in the system, apparatus, process, or computer-readable medium described in the drawings.
[0020] Described herein is a system and a method that provides an interface between advertisers and media stations (e.g., radio and television stations). In an embodiment, the interface facilitates a wide-area network-based production model. In a further embodiment, the model allows an advertiser to modify advertisement content at or near real-time. For the purposes of this description, “radio” and “radio transmissions” include terrestrial or satellite audio transmissions.
[0021] Referring to the figures, FIG. 1 is a block diagram of an advertisement production system 100 in accordance with an example embodiment. The advertisement production system 100 includes an audio advertising system 102 , a fulfillment system 104 , a client computer 106 , a broadcast station 108 , and a voice-over user computer 110 , all communicatively coupled via a network 112 . In an embodiment, the advertisement production system 102 includes a web server 114 , a messaging server 116 , an application server 118 , a database server 120 , an operations database 122 , an audio database 124 , and an advertising performance database 126 . In an embodiment, the database server 120 is used to manage at least one of the operations database 122 , audio database 124 , or advertising performance database 126 . The audio advertising system 102 may be implemented as a distributed system, for example one or more elements of the audio advertising system 102 may be located across a wide-area network from other elements of the audio advertising system 102 .
[0022] The fulfillment system 104 may include businesses, such as call centers, warehouses, distribution centers, production houses, storage facilities, shipping facilities, rebate management, billing facilities, and the like. The fulfillment system 104 can be used to handle customer inquiries, fulfill orders, and handle product returns or other customer issues. In some embodiments, the fulfillment system 104 includes two or more businesses acting in cooperation with each other. For example, a call center, a warehouse, and a shipping company may act together to receive orders, package merchandise, and ship packages to the customer.
[0023] The client computer 106 may be used to access the audio advertising system 102 to create, manage, and track advertisements. For example, using a user-interface, such as an internet web browser, a user at the client computer 106 can access the web server 114 in the audio advertising system 102 . The client computer 106 may also be used to track inquiries, sales, and other performance data from the fulfillment system 104 . The client computer 106 may also be used to track advertising activity at the broadcast station 108 , such as when an advertisement was aired, who the active demographic was when the advertisement was aired, and other advertising metrics related to the advertisement's transmission.
[0024] The broadcast station 108 may include a radio stations, a television station, a satellite radio station, a high-definition radio station, an internet broadcast station, or other business that broadcasts content over a broadcast medium. The broadcasted content may be distributed over the network 112 , for example as a streaming radio broadcast. The broadcasted content may also be broadcasted over terrestrial or satellite networks using radio frequency (RF) transmission.
[0025] The voice-over user computer 110 may be used by a voice-over performer (not shown) to access the audio advertising system 102 , as described in more detail below. The voice-over computer 110 may include a personal computer, a hand-held computer, a mobile computer, or any other suitable network-capable computing device. The voice-over computer 110 may be a part of a recording studio or recording system.
[0026] The network 112 may include local-area networks (LAN), wide-area networks (WAN), wireless networks (e.g., 802.11 or cellular network), the Public Switched Telephone Network (PSTN) network, ad hoc networks, personal area networks (e.g., Bluetooth), virtual private networks (VPN), or other combinations or permutations of network protocols and network types. The network 112 may include a single local area network (LAN) or wide-area network (WAN), or combinations of LAN's or WAN's, such as the Internet. The various devices coupled to the network 112 may be coupled to the network 112 via one or more wired or wireless connections.
[0027] Turning now to the components of the audio advertising system 102 , the web server 114 may be configured to publish or serve files. The web server 114 may also communicate or interface with the application server 118 to enable web-based presentation information. For example, the application server 118 may consist of scripts, applications, or library files that provide primary or auxiliary functionality to the web server 114 (e.g., multimedia, file transfer, or dynamic interface functions). In addition, the application server 118 may also provide some or the entire interface for the web server 114 to communicate with one or more of the other servers in the audio advertising system 102 , e.g., the messaging server 116 or the database management server 120 .
[0028] The operations database 122 may include data used to administer user accounts, security information (e.g., passwords, personal identification number (PIN)), billing data, or the like. The audio database 124 may include data used to present, store, and track audio tracks and files used in advertising. The advertising performance database 126 may include data used to store, track, and manage advertising metrics, such as how many times an advertisement was broadcasted, over what period of time, to what audience demographic, and what sales resulted from the broadcasted advertising. Other advertising metrics may be stored in the advertising performance database 126 , some of which are described below.
[0029] The advertising performance database 126 may also include tracking data such as when an advertisement was broadcasted, where the advertisement was broadcasted (e.g., radio station, geographic region), advertising response statistics, or other performance metrics related to an advertisement or an advertising campaign.
[0030] Databases in the audio advertising system 102 , including the operations database 122 , the audio database 124 , and the advertising performance database 126 , may be implemented as a relational database, a centralized database, a distributed database, an object oriented database, or a flat database in various embodiments.
[0031] During operation, in an embodiment, a user can use the client computer 106 to connect with the audio advertising system 102 via the network 112 . Using a user-interface provided by the audio advertising system 102 , such as via the web server 114 , the user can construct an advertisement. In an embodiment, the user can provide a script to the audio advertising system 102 . The script may be stored in the operations database 122 for later reference. The audio advertising system 102 may access the audio database to present pre-recorded voice samples or other audio samples to the user. In addition, the audio advertising system 102 may provide information describing available live performers (e.g., voice-over performers). The user can then select a voice sample, audio sample, or live performer that is suitable and generate an audio advertisement. If the user chooses a live performer, then an order request can be generated and communicated to a voice-over user at the voice-over user computer. The live performer can record their rendition of the script and transmit it to the audio advertising system 102 , which may store it in the audio database 124 . In some embodiments, the user may select more than one voice samples, audio samples, or live performers to use in combination. The user can then test the audio advertisement and make adjustments using the user-interface provided by the web server 114 . The test can be performed in an online medium. This may be advantageous to reduce costs or to increase exposure. Online test results can be stored in the advertising performance database 126 . Periodically, the user can revise the advertisement and continue testing in the online environment. Once the user is satisfied with the quality of the advertisement, the user can publish it to a broadcast station 108 . In another example embodiment, the audio advertising system 102 may automatically determine that the advertisement is of sufficient quality and transmit the advertisement to the broadcast station 108 for use in a commercial context.
[0032] The broadcast station 108 may broadcast the advertisement on a periodic or recurring schedule. The advertisement may contain a way to contact the advertiser, such as a web site address, a telephone number, or other means. A listener who is interested in the advertised material can contact the fulfillment system 104 to obtain more information about a product or service, place an order, or manage an existing order. The broadcast station 108 and the fulfillment system 104 can transfer advertising data to the audio advertising system 102 , which may store the data in the advertising performance database 126 for analysis. Advertising data may include data such as the advertisement broadcasted, the time of the broadcast, the broadcast station that broadcasted the advertisement, the demographic of the broadcast station, the number of contacts, the contact method used, the result of the contact (e.g., inquiry or order), the cost of the advertisement, and the like. Using this data, the audio advertising system 102 can analyze and compile advertising performance metrics, such as advertisement cost per order. The advertising performance metrics may be presented to the user at the client computer 106 , who may then revise the advertisement or construct new advertisements.
[0033] FIG. 2 is a data flow diagram 200 of an advertisement product system in accordance with an example embodiment. At 202 , an audio advertisement is generated. In an embodiment, a user can access the audio advertising system 102 to generate an audio advertisement. At 204 , the audio advertisement is tested online. For example, the audio advertisement may be presented to online users via a network, such as network 112 , using technologies such as webcasting using streaming audio. In other examples, an audio file may be presented using a plug-in player, such as WINDOWS MEDIA PLAYER as provided by MICROSOFT, Inc. or QUICKTIME as provided by APPLE, Inc. The audio file may be formatted using industry-standard formats, such as MPEG-1 (Moving Picture Experts Group) Audio Layer 3 (*.mp3), Waveform Audio Format (*.wav), Advanced Audio Coding (AAC) (MPEG-4 Part 3), or Windows Media Audio (*.wma), as well as other digital media formats. The effectiveness of the online testing can be measured, tracked, and stored (block 218 ). If the effectiveness of the online test is below a threshold value (e.g., based on response rate, click through traffic, or resulting orders or inquiries), then the advertisement may be revised manually or automatically. The revised advertisement can then be tested again in the online medium.
[0034] At 206 , after testing, the advertisement is moved to the broadcast station 108 . The broadcast station 108 can then broadcast the advertisement to an online user 208 or a listener 210 . The online user 208 and listener 210 are examples of people that may receive the broadcasted advertisement. Typically, a listener 210 is a person who is receiving an audio broadcast over a radio frequency transmission, such as radio broadcasting, while an online user 208 is a person who is receiving an audio broadcast over a network, such as the Internet.
[0035] At 212 , the broadcast station can transfer broadcast metric data to the advertising performance database 126 associated with the audio advertising system 102 . Broadcast metric data may include data such as play times, estimated audience size or demographic, cost of airtime, and the like.
[0036] At 214 , after hearing the broadcasted advertisement, the online user 208 or the listener 210 may wish to inquire or order the product or service advertised. In an embodiment, the online user 208 or listener 210 may contact the fulfillment system 104 , for example, by using a toll-free phone number provided in the advertisement. The fulfillment system 104 can then obtain the order information and arrange for the advertised service to be rendered or the advertised product to be shipped.
[0037] At 216 , information related to inquiries or orders is communicated to the advertising performance database 126 . By correlating the broadcast times or geographies with fulfillment system information, the advertiser can gain a better understanding of the effectiveness of the advertisement.
[0038] At 218 , the effectiveness of an advertisement can be measured during various times during the process. Depending on the result of the measurement, the advertisement may be revised. For example, after receiving fulfillment system data, an advertiser may revise or replace an advertisement at the process block 202 . As another example, during online testing, at process block 204 , an advertiser may revise or replace an advertisement based on test results.
[0039] FIG. 3 is a flow diagram illustrating a method 300 for creating an advertisement in accordance with an example embodiment. At 302 , an advertising script is received. The advertising script may be formatted in a standardized interface language, such as Extensible Markup Language (XML), or as a plain text file, in various embodiments. The advertising script may be submitting using an internet-enabled user-interface, such as a web browser HTML form.
[0040] After receipt of the script, at 304 , one or more user selections are detected, where the user selections indicate corresponding voice characteristics. In an embodiment, a user-interface can be presented to a user via a web browser and the user can select one or more options that represent voice characteristics. In various embodiments, the voice characteristics may include aspects such as the gender, age, language, accent, style, identity, or notoriety of the speaker.
[0041] At 306 , audio tracks are searched to find close or exact matches of voices that correlate to the selected voice characteristics. In an embodiment, the audio tracks are stored in the audio database 124 . In further embodiments, the audio tracks may include a voice sample, a synthesized voice sample, or a recorded voice track.
[0042] At the decision block 308 , if results are found, then at 312 , the results are presented to a user. If, however, there are no results that match or are closely correlated, then at 310 , an error message is presented. In various embodiments, the error message may include a suggestion of how to improve or modify a query such that the query will result in at least one search result.
[0043] At 314 , a selected search result is received. The selected search result may include one or more voice tracks, in an embodiment. At 316 , the script is used in combination with the selected voice track to compile an advertisement.
[0044] FIG. 4 is a flow diagram illustrating a method 400 for creating an advertisement in accordance with an example embodiment. The method described in FIG. 4 is similar to the method shown in FIG. 3 , except that in the event that no search results are found, at 411 , a modification of one or more search parameters is suggested to the user. For example, if the initial search parameters (voice characteristics) were “male,” “Brooklyn accent,” and “youthful,” which when used did not result in any matching voice tracks, then a suggested modified search may include “male” and “youthful,” which would provide search results. Various methods may be employed to suggest alternative queries to a user that may result in a non-empty search result set, such as ranking search terms by their popularity, ranking search terms by the number of hits, grouping search terms in combinations that provide a threshold number of results, and the like. In an embodiment, the analysis and suggested modification is performed using a neural network. In general, a neural network is capable of using heuristic programming or fuzzy logic to approximate a learning system. In another embodiment, discrete analysis is used to determine a modified search.
[0045] FIG. 5 is a flow diagram illustrating a method 500 for creating an advertisement in accordance with an example embodiment. The method described in FIG. 5 is similar to the method shown in FIG. 3 , except that after the script is provided (block 502 ) and one or more user selections are detected (block 504 ) the method 500 may suggest modifications (block 505 ). The method 500 may suggest modification to the script's copy, voice characteristics selected by the user, or other advertisement information. In an embodiment, using advertising performance database 126 , the method may determine a correlation between a particular voice characteristic and advertising performance. The advertising performance may be an estimate based on past result or past performance of the same or similar advertisements. For example, if a user selects “male,” “British accent,” and “mature voice,” as voice characteristics, the method 500 may determine that using a mature British voice is generally less successful than using a youthful British voice. The method 500 may provide such information to the user and suggest a modification or revision of the selected voice characteristics. As another example, an advertisement for a weight loss treatment may include the phrase “lose weight.” Using past performance of similar advertising, the method 500 may determine that the use of the phrase “get fit” has been observed to be more effective than using the phrase “lose weight.” Using this information, the method 500 may provide a suggested revision to the script's copy along with statistics to allow the user to make an informed decision whether to revise the script. Similar to the method in FIG. 4 , in some embodiments, block 505 may be implemented using a neural network, discrete analysis, or other analysis technique.
[0046] In some embodiments, the suggested modification or revision blocks of FIG. 4 (block 411 ) and FIG. 5 (block 505 ) may be used in combination to provide a user more guidance and input during the advertisement creation or revision process.
[0047] FIG. 6 is a flow diagram illustrating a method 600 for suggesting a modification to an advertisement in accordance with an example embodiment. The suggested modification may include a change in advertising copy (e.g., words or phrases) or a change in selected voice characteristics. In various embodiments, the method 600 may be used at block 411 in FIG. 4 or block 505 in FIG. 5 , or at both steps.
[0048] At 602 , an advertising context is determined. The advertising context may be formed by one or more advertising characteristics, such as the type of advertisement, the target market, the product being advertised, the length of the advertisement, and the like. The advertising context may be obtained, at least in part, by analyzing the advertisement script. For example, the advertisement script may be searched for one or more key words that identify a product or service being sold or advertised, a target market, an advertisement genre, or other advertising characteristics. The advertisement context may also be obtained, at least in part, by analyzing an advertisement profile. An advertisement profile may be one or more parameters that describe the advertisement script. The one or more parameters may be input by a user using a user-interface, such as one described with reference to FIG. 9 .
[0049] At 604 , the advertisement script is analyzed. The analysis may be performed using a neural network, discrete analysis, or other analytical techniques, in various embodiments. In an embodiment, the analysis includes deconstructing the advertisement script into a plurality of words, determining an estimated efficacy of each word in the plurality of words, and replacing a word when the estimated efficacy is below a threshold value. For example, each word in a script can be classified into a grammatical category, such as noun, verb, adjective, adverb, object or the like. Some common words or connecting words, such as the conjunctions “and” and “or” may be ignored by the analysis. Words may then be ranked or otherwise sorted by effectiveness based on a corresponding advertising context. Words may also be sorted and grouped by grammatical categories, which may then be ranked or otherwise sorted by effectiveness based on a corresponding advertising context. In an embodiment, for each word, a database can be searched for a corresponding word and the estimated efficacy of the word being analyzed and the corresponding word found can be compared using an advertisement context based on an advertisement feature. In an embodiment, the advertisement feature may include an advertisement type, a product, a sub-product, an advertisement length, a target market, and a target platform. Thus, the estimated efficacy of a word may be dependent on the advertising context or advertising feature. For example, a word's efficacy may differ when viewed in the context of an advertisement of a particular product versus an advertisement for a particular target market.
[0050] In another embodiment, the analysis (block 604 ) includes deconstructing the advertisement script into a plurality of phrases, determining an estimated efficacy of each phrase in the plurality of phrases, and replacing a phrase when the estimated efficacy is below a threshold value. Phrase analysis may be more effective in some situations where individual words are too generic to analyze. For example, the phrase “I wanna be like Mike” is a powerful catch phrase from GATORADE commercials featuring Michael Jordan, but each word individually may lack marketing substance. Determining the estimated efficacy of each phrase may include for each phrase, searching a database for a corresponding phrase, and comparing the estimated efficacy of each phrase to an estimated efficacy of the corresponding phrase, using a advertisement context based on an advertisement feature, wherein the advertisement feature is selected from the group of advertisement features consisting of an advertisement type, a product, a sub-product, an advertisement length, a target market, and a target platform, in embodiments.
[0051] Advertisement types can include modes, such as radio, television, or internet; production styles such as film, commercial, animated, or documentary; or themes such as parody, comedic, political, satirical, informational, or storyline, in various embodiments. The advertisement length may be dependent on the mode of the advertising, for example, a television advertisement may be standard thirty seconds, while an internet advertisement may be shorter or longer, depending on the context. An advertising market may be defined using a target demographic. A target platform can include the intended broadcast medium for the advertisement, such as radio, television, webcast, etc.
[0052] The threshold value used to determine whether a word or phrase is preferable may be set by a user (e.g., an administrator or advertiser) or automatically by the system 102 . The threshold value may be a function of advertisement response (e.g., number of orders per thousand impressions), advertisement usage (e.g., the reliability of corresponding performance data may be dependent on the number of times an advertisement is broadcast), or other advertising statistics.
[0053] In embodiment, revisions may be based on analysis that includes comparing the advertisement script to a corpus of previously used scripts. For example, the corpus of scripts may include scripts of a similar genre, scripts from the same or similar advertiser, or scripts for the same or similar product. Other similarities may be used to determine a relevant corpus of scripts. The corpus of previously used scripts may be stored in the advertising performance database 126 , along with advertising performance metrics. Using the advertising performance metrics, the method 600 may provide a revision of the advertisement script.
[0054] At 606 , using the advertising context determined at block 602 , one or more revisions may be determined and provided to the user. The revisions may include modifications or additions to the script's text, organization, or theme, in various embodiments. The revisions may further include modifications or additions to selected voice characteristics, in embodiments. The revisions can be based on the characteristics identified in an effort to maximize the efficacy of an advertisement for the particular advertising context.
[0055] FIG. 7 is a flow diagram illustrating a method 406 for presenting audio track options to a user in accordance with an example embodiment. At 702 , one or more voice characteristics are received. In an embodiment, the voice characteristics are those selected by a user, such as in step 404 in FIG. 4 . Voice characteristics may include the accent, gender, age, language, style, or identity of a speaker. Voice characteristics may further include whether the voice is a recorded human voice or a synthesized voice.
[0056] At 704 , a database is searched for pre-recorded voice tracks. Pre-recorded voice tracks may include words or phrases that, when concatenated, can form a full audio version of an advertising script. Pre-recorded voice tracks may also include individual syllables to combine, concatenate, or arrange to create an audio version of the advertising script. In an embodiment, pre-recorded voice tracks are associated with one or more voice characteristics in the database, such that when searching for a particular voice characteristic, the associated voice track can be identified and retrieved.
[0057] At 706 , those voice tracks that match or correspond with the provided voice characteristics are added to a search result. The search result may be sorted, grouped, or otherwise arranged into rankings, classifications, or categories, to provide conceptual or visual organization to a user when the search result is presented.
[0058] At 708 , a database is searched for synthesized voice tracks. Synthesized voice tracks may include computer-generated voice samples or acoustically-modified, recorded human voices. Similar to the pre-recorded voice tracks, the synthesized voice tracks may be associated with one or more voice characteristics to enable searching, sorting, and organizing. At 710 , those synthesized voice tracks that match or correspond with the provided voice characteristics are added to the search result.
[0059] At 712 , a database is searched for live performers that have voice characteristics similar to those specified. Live performers are typically voice-over artists that can professionally read an advertisement script for a broadcast medium. In some cases, live performers may include famous or notorious people that are willing to provide a voice-over track for compensation or charity. At 714 , those live performers that match or correspond with the provided voice characteristics are added to the search result.
[0060] FIG. 8 is a graphical user-interface illustrating a script edit screen 800 for creating or editing an advertisement in accordance with an example embodiment. The script edit screen 800 includes a script title control 802 and a script text control 804 . A user can input a script title using the script title control 802 to later identify and recognize the script. The script title control 802 may be programmatically controlled to constrain an attribute of the script title control 802 , such as the length or content. For example, a maximum length of eighty characters may be imposed on the script title. As another example, certain characters, such as special characters like “!,” “@,” or “̂” may be prohibited in a script title.
[0061] The script text control 804 may be similarly controlled to constrain the content, length, or other attribute. After a user inputs a script title and text, activating the save control 806 can save the inputted content. If the user decides to discard the content, for example, when making changes to the script and then deciding later to abandon those changes, the user can activate the cancel control 808 to exit the script edit screen 800 .
[0062] FIG. 9 is a graphical user-interface illustrating a script edit screen 900 for editing script features in accordance with an example embodiment. The script edit screen 900 may include one or more script features, organized into a general portion 902 , a speaker portion 904 , and a background portion 906 . The general portion 902 may include general features associated with a script. For example, the advertisement type 908 , the product being advertised 910 , the sub-product 912 , the length of the advertisement 914 , the target market 916 , and the target platform 918 . In the example shown, these various controls are provided as drop down lists. In other examples, the input controls may include other forms, such as radio buttons, check boxes, text fields, and the like.
[0063] The speaker portion 904 of the script edit screen 900 may include attributes of a speaker or a recorded voice. For example, the attributes or characteristics may include an accent 920 , a gender 922 , an age, 924 , a language 926 , a style 928 , or an identity 930 . In some embodiments, when an identity is selected using the identity control 930 , the other controls are disabled or ignored. In other embodiments, controls specifying a particular voice attribute may be combined with a personality voice to create a derivative voice. For example, if a user selected “Captain Kirk” as a famous voice using the identity control 930 and an accent of “Scottish” using the accent control 920 , the system may provide a derivative voice using the combination of the two.
[0064] The background portion 906 includes controls to designate background noises or music. For example, the background portion 906 may include a music control 932 and an environmental control 934 . The music control 932 can be used to select a jingle, music theme, or other sound track to be played in the background during a script's narration. The environmental control 934 can be used to designate a different type of background noise. Examples of environmental noises include cooking sounds, car traffic, airplane engines, discussions or talking, running water, wind, or the like.
[0065] After a user inputs script features, activating the save control 936 can save the features. If the user decides to discard changes, the user can activate the cancel control 938 to exit the script edit screen 900 .
[0066] FIG. 10 is a graphical user-interface illustrating a script suggested revisions screen 1000 for suggesting revisions to a script in accordance with an example embodiment. The script suggested revisions screen 1000 may include a script text control 1002 to present a marked up version of the script text to a user. In the example shown, a suggested revision of replacing the word “hate” with the word “dislike” is presented in the script text control 1002 . The suggested revision may be based on analysis, such as that described above with relation to FIG. 6 . The user may make further revisions to the text using the script text control 1002 and accept the changes using the accept control 1004 or reject the suggested revisions using the ignore control 1006 .
[0067] FIG. 11 is a graphical user-interface illustrating a search results screen 1100 for providing search results in accordance with an example embodiment. The search results screen 1100 may include a recorded voices portion 1102 and a voice-over speakers portion 1104 . The recorded voices portion 1102 may include pre-recorded human voices and synthesized voices. The voice-over speakers portion 1104 may include names or identities of voice-over performers that match or correspond with provided voice characteristics. Each voice sample, voice track, or identified voice-over performer may include a brief description 1106 of the voice sample or speaker and a playback control 1108 to listen to a sample of the voice sample or speaker. Also, each voice sample can include a selection control 1110 to select a particular voice sample. In the example shown, the selection control 1110 is a radio button, which restricts the user to choosing a single selection. In other examples, a checkbox control may be used as the selection control 1110 , which can allow a user to choose two or more voice samples. The system may use the selected voice sample in a duet-like narration or other combination.
[0068] The user may indicate the selected voice sample using the select control 1112 or cancel the search using the cancel control 1114 . Activating the select control 1112 can submit the selected voice sample or voice samples to be used in the advertisement.
[0069] FIG. 12 is a flow diagram illustrating a method 1200 for revising an advertisement in accordance with an example embodiment. At 1202 , an advertisement is received. The advertisement may be the result of a process, such as that described in FIGS. 4-6 . At 1204 , the advertisement is presented in an online medium, such as in a webcast over the Internet. Other examples of online media include an audio file served in a web page, an audio advertisement played over a cellular phone, or an audio advertisement delivered over satellite or high-definition radio. An indicia of effectiveness is received at block 1206 . The indicia may be the number of sales that are a result of the advertisement. The indicia may include other data, such as the number of inquiries of an advertised product or service, a number of web page hits, a number of phone calls received, a number of promotional coupons redeemed, or the like. Other indicia may include professional product reviews, editor comments or reviews, consumer reviews, news stories or other articles that mention, describe, praise, or criticize the advertised product or service, or other press. In an embodiment, if the effectiveness of an advertisement is over a threshold value, the advertisement can be delivered to a broadcast station for commercial use.
[0070] The indicia of effectiveness is stored (block 1208 ) and analyzed (block 1210 ). The indicia may be stored in the advertising performance database 126 , in an embodiment. The indicia may be compared to one or more threshold values, such as a predicted number of sales, to determine whether, or to what extent, the advertisement campaign can be considered successful. In an embodiment, the analysis includes parsing the text-based advertisement script to determine a characteristic, such as a type of advertisement, a type of content, a target market, an advertisement structure, and a target advertising platform. Using the characteristic, the method 1200 can determine a revision that may make the advertisement more effective.
[0071] At 1212 , the advertisement is revised. In an embodiment, the advertisement script is automatically revised by the method 1200 . In an embodiment, the revised advertisement script is presented to a user for approval before a revised advertisement is generated. The revised advertisement script may be presented in a user-interface, such as the one illustrated in FIG. 10 . In an embodiment, an audio characteristic associated with the advertisement is revised by the method 1200 . Audio characteristics may include features such as those described in FIG. 9 . For example, if the unmodified advertisement used a mature female voice, the method 1200 may determine that a youthful male voice may be more effective and suggest the revised features. Determining what revisions may be appropriate to increase the effectiveness of the advertisement can be performed by a neural network, in an embodiment. For example, a neural network may analyze the data stored in the advertising performance database 126 and determine that for a particular type of advertisement broadcast over a particular type of medium, a textual or audio modification may produce better advertising results.
[0072] At 1214 , statistics and data can be reported to the user. For example, sales data, impression data, and other performance data can be collected and presented. The user may desire to make other modifications to the advertisement using the presented data.
[0073] FIG. 13 illustrates a diagrammatic representation of a machine 1300 capable of performing the methods or implementing the systems/devices described herein. In alternative embodiments, the machine may comprise a computer, a network router, a network switch, a network bridge, a Personal Digital Assistant (PDA), a cellular telephone, a web appliance, a set-top box (STB) or any machine capable of executing a sequence of instructions that specify actions to be taken by that machine.
[0074] The machine 1300 includes a processor 1302 , a main memory 1304 , and a static memory 1306 , which communicate with each other via a bus 1308 . The machine 1300 may further include a video display unit 1310 (e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)). The machine 1300 also includes an alphanumeric input device 1312 (e.g., a keyboard), a cursor control device 1314 (e. g., a mouse), a disk drive unit 1316 , a signal generation device 1318 (e.g., a speaker) and a network interface device 1320 to interface the computer system to a network 1322 .
[0075] The disk drive unit 1316 includes a machine-readable medium 1324 on which is stored a set of instructions or software 1326 embodying any one, or all, of the methodologies described herein. The software 1326 is also shown to reside, completely or at least partially, within the main memory 1304 and/or within the processor 1302 . The software 1326 may further be transmitted or received via the network interface device 1320 .
[0076] For the purposes of this specification, the term “machine-readable medium” or “computer-readable medium” shall be taken to include any medium which is capable of storing or encoding a sequence of instructions for execution by the machine and that cause the machine to perform any one of the methodologies of the inventive subject matter. The term “machine-readable medium” or “computer-readable medium” shall accordingly be taken to include, but not be limited to, solid-state memories, optical and magnetic disks, and carrier wave signals. Further, while the software is shown in FIG. 13 to reside within a single device, it will be appreciated that the software could be distributed across multiple machines or storage media, which may include the machine-readable medium.
[0077] Method embodiments described herein may be computer-implemented. Some embodiments may include computer-readable media encoded with a computer program (e.g., software), which includes instructions operable to cause an electronic device to perform methods of various embodiments. A software implementation (or computer-implemented method) may include microcode, assembly language code, or a higher-level language code, which further may include computer readable instructions for performing various methods. The code may form portions of computer program products. Further, the code may be tangibly stored on one or more volatile or non-volatile computer-readable media during execution or at other times. These computer-readable media may include, but are not limited to, hard disks, removable magnetic disks, removable optical disks (e.g., compact disks and digital video disks), magnetic cassettes, memory cards or sticks, random access memories (RAM's), read only memories (ROM's), and the like.
[0078] 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 achieves the same purpose, structure, or function may be substituted for the specific embodiments shown. This application is intended to cover any adaptations or variations of the example embodiments of the invention described herein. It is intended that this invention be limited only by the claims, and the full scope of equivalents thereof.
[0079] The Abstract is provided to comply with 37 C.F.R. §1.72(b), which requires that it allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment. | This document describes, among other things, systems and methods for generating advertisements for use in broadcast media. A method comprises receiving an advertisement script at an online system; receiving a selection indicating a voice characteristic; and converting the advertisement script to an audio track using the selected voice characteristic. | 6 |
FIELD OF THE INVENTION
This invention relates to a vehicle differential having multiple modes of operation and more particularly to a shift mechanism for shifting the differential between the different modes.
BACKGROUND OF THE INVENTION
A substantial number of vehicles are designed to have the versatility of two-wheel drive and four-wheel drive. In two-wheel drive, either the front pair of wheels or the rear pair of wheels are connected to the vehicle's power source. In four-wheel drive, both the front and rear pair of wheels are connected to the power source.
Each pair of wheels have a pair of axles connected to a differential which in turn is connected to a propeller shaft driven by the vehicle's power source. A front propeller shaft is connected to the front differential and a rear propeller shaft is connected to the rear differential. One of the propeller shafts is disconnected from the vehicle's power source for two-wheel drive.
Referring to the differential for the wheel set that can be connected and disconnected from the power source (commonly the front wheel set or front pair of wheels), the primary function of the differential is to permit the left and right wheels to rotate at different speeds. This is accomplished by a gear assembly that includes a differential case that is rotatably driven by the propeller shaft. Opposing side gears in the differential case are coupled to the axles and the opposing side gears are coupled together by pinion or spider gears commonly referred to as differential gears which are rotatably mounted to the case of the differential.
The arrangement of gears in the differential transmits torque from the propeller shaft to the axles which in turn transmits the torque to a pair of front end or rear end wheels. The torque of the axles is always equal regardless of the speed of the axles relative to each other. When the axles are connected to wheels having similar tractive capacity, the axles rotate equally or, if the vehicle is in a turn, they rotate differently according to the turning radius of each wheel. Differential axle rotation in this case is desirable for normal vehicle operation. When the axles are connected to wheels having substantially different tractive capacity, the wheel having lesser tractive capacity may slip, thus causing the axle connected to it to turn faster than the axle connected to the wheel having greater tractive capacity. Differential axle rotation in this case is undesirable for normal vehicle operation.
The above explanation explains two circumstances or modes for a differential, i.e., allowing the differential to provide differential axle rotation and preventing differential axle rotation. A third desired mode occurs when the propeller shaft for that set of wheels is disconnected from the vehicle's power source, i.e., the vehicle is placed in two-wheel drive. Once the propeller shaft is disconnected from the power source, the propeller shaft is passive (it does not convey a driving torque). However, it is still driven in that the wheels of that wheel set are forced to turn as the vehicle is driven in two-wheel drive and they drive the axles which drive the differential gears which drive the propeller shaft. In this event, it is desirable to separate or disconnect the propeller shaft from the driven axles (the third mode) to avoid unnecessary rotation of the propeller shaft and thereby save energy and wearing.
Accordingly, it is an object of the present invention to provide a shift mechanism for the differential for shifting the differential between the above-explained three modes.
BRIEF DESCRIPTION OF THE INVENTION
In a preferred embodiment of the present invention, the propeller shaft is connected to a pinion gear that drives a ring gear that is connected to a differential case. The differential case (through a cross pin and spider gears) rotates opposing side gears, one of which rotates a first wheel axle and the other a stub axle. The stub axle is adjacent a second wheel axle and a clutch ring is movable between a position of engagement with only the stub axle or a position of engagement with both the stub axle and second wheel axle.
If the stub axle is locked to the second wheel axle, the wheels are driven as is typical for a differential as explained above. If the stub axle is unlocked from the second wheel axle, the stub axle rotates freely, i.e., with very little resistance in either direction of rotation. In such case, the propeller shaft is effectively uncoupled from the wheel axles. The first wheel axle, which is connected to the differential assembly will simply drive the differential gears and stub axle (and not the differential case) and thereby allow the propeller shaft and the ring gear and pinion gears to remain idle, assuming that the propeller shaft is also disconnected from the power source.
The clutch ring has a third position of engagement whereby it not only locks the stub axle to the second wheel axle but it locks both to the differential case. If either one of the wheel axles are locked to the case, the gears of the case are locked together and prevent relative rotation. Thus, both wheel axles are locked to the differential case and differential rotation of the wheels is prevented.
The structure for achieving this three mode positioning includes a clutch ring with inner and outer teeth. The stub axle and second wheel axle are in close adjacency and have matching outer splines. The inner teeth of the clutch ring produce engagement as between the stub axle and the second wheel axle. The differential case is configured to have a ring-shaped or flange portion with inner splines in close proximity to the juncture of the stub axle and second wheel axle. These inner splines of the case are matched to the outer splines of the clutch ring for engagement therebetween. In the desired arrangement, the clutch ring can be moved first into engagement with both axle portions and then, as desired, into engagement also with the inner splines of the differential case.
An actuator for actuating movement of the clutch ring includes an inner shift spring assembly connected to posts that extend axially through the differential case to position outside the case and connect to an outer shift ring. The shift ring, shift ring assembly and shift posts rotate with the case but have limited axial movement relative to the case. A shift shaft is coupled to the outer shift ring outside the differential case. The clutch ring is coupled to the inner shift spring assembly and posts at a position inside the differential case.
The shift shaft protrudes through the differential carrier where a power source produces the desired linear shifting movement of the shift shaft. The shift shaft does not rotate with the shift ring and thus the coupling to the outer shift ring includes a shift fork including bearing members that allow relative rotation as between the outer shift ring and shift fork but not axial/linear movement. This linear movement of the shift shaft produces linear movement of the shift fork and thus linear movement of the outer shift ring and posts. The clutch ring is rotatably fixed to the stub axle and in two of the three modes has to be capable of rotative motion relative to the differential case and thus the outer shift ring and posts. Thus, the coupling as between the posts and clutch ring includes bearing members (provided by the shift spring assembly) that allows relative rotation as between the posts/shift ring. Thus, linear movement of the shift rings (induced by the shift shaft) induces similar linear movement of the clutch ring.
The clutch ring movement is not always subject to instant selective movement and thus the coupling between the posts/shift ring and clutch ring is accomplished by compliant members of the spring assembly which urge the clutch ring into engagement. In the event the splines of the components to be engaged are not in alignment, the clutch ring is thus spring loaded toward engagement and achieves engagement when the splines become aligned. It can also happen that the splines become torque locked when disengagement is attempted and the compliant springs will similarly become spring locked until torque lock up is released.
The features as described above will be more fully understood and appreciated upon reference to the following detailed description and the accompanying drawings referred to therein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a vehicle chassis illustrating an arrangement of a drive train including a differential as may incorporate the present invention;
FIG. 2 is a cross sectional view of a differential incorporating the present invention;
FIG. 3 is a perspective view of the differential of FIG. 2 excluding the carrier portion;
FIG. 4 is a perspective view of a shifting mechanism provided for the differential of FIGS. 2 and 3; and
FIG. 5 is a frontal view of certain of the components of the shifting mechanism of FIG. 4 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference is made to FIG. 1 which substantially illustrates a drive train of a vehicle. Illustrated are front wheels 10 and rear wheels 12 . An engine 14 drives a drive shaft 16 connected to a transmission 18 . The transmission drives a rear wheel propeller shaft 20 connected to a rear wheel differential 22 that drives rear wheel axle 24 which in turn drives the rear wheels 12 . A drive connection from the transmission to a transfer case 28 drives a front wheel propeller shaft 30 connected to a front wheel differential 32 . The front wheel differential is connected to front axles 34 which drive the front wheels 10 .
As illustrated, the shift mechanism for shifting into and out of four-wheel drive occurs at the transfer case 28 and places front wheel propeller shaft 30 into and out of engagement with the transmission 18 and thus the drive shaft 16 of the engine 14 . The invention is accordingly incorporated into the front differential 32 although it will be understood that the drive train can be arranged to provide the shift mechanism to engage and disengage rear wheel propeller shaft 20 in which case the invention would be incorporated into rear differential 22 . Hereafter whereas the differential may be described as the front differential, it will be understood that such is for descriptive convenience and the invention just as readily can and does apply to the rear wheel differential.
Reference is now made to FIG. 2 which illustrates front differential 32 including an outer fixed housing referred to as a carrier 50 . Connected into the left side of the differential carrier (as illustrated) is left axle 34 L and connected into the right side of the differential is right axle 34 R. Axle 34 L terminates at end 40 which is spline fit to a side gear 42 . Axle 34 R terminates at end 44 which is interfit with stub axle 46 . End 44 is rotatable relative to stub axle 46 . Stub axle 46 is spline fit to a second side gear 48 which opposes side gear 42 .
Rotatably mounted in the carrier 50 and surrounding the axle ends 40 , 44 , 46 and side gears 42 , 48 is a differential case 52 that rotates relative to the carrier on bearings 54 . Mounted to the case are opposed spider or differential gears 56 , only one of which is shown in FIG. 2 . Spider gears 56 are rotatable relative to case 52 on pivot shaft 58 and they are in splined engagement with opposed side gears 42 , 48 connected to axle end 40 and stub axle 46 , respectively.
Connected to the differential case 52 is propeller shaft 30 which rotatably drives pinion gear 60 (rotatably mounted in differential carrier 50 by bearing 62 ). Gear 60 has gear teeth interfit with gear teeth of ring gear 64 which is bolted to differential case 52 by bolts 66 . Thus, as propeller shaft 30 is rotatably driven by the engine 14 , transmission 18 and transfer case 28 , that rotation is transferred to the differential case 52 which rotates about axis 68 (which also the axis of axles 34 ). As the case 52 is rotated about axis 68 , so too is the pivot shaft 58 of gears 56 .
In a conventional differential arrangement, the separate stub axle 46 and axle 34 R are provided as a single axle that is interfit to gear 48 in a manner similar to axle 34 L and gear 42 . As the case 52 and the shaft 58 with gears 56 are rotated about axis 68 (by propeller shaft 30 ), the interfit between gears 56 and gears 42 , 48 provides for common rotation of axles 34 L and 34 R. This assumes that the resistance to the turning of axles 34 R and 34 L is similar in which case the gears 56 do not rotate around the axis of pivot shaft 58 . Should one of the axles 34 L, 34 R generate a greater resistance to turning than the other, gears 56 rotate about pivot shafts 58 to equalize the torque applied to the two axles and thereby permit differential rotation of the axles.
The above operation of the differential is well known to those skilled in the art and further explanation is not necessary. As explained in the introductory portion, the accommodation of differential turning of axles 34 L and 34 R is desirable at times, e.g., when turning the vehicle (which requires the outside wheels to turn faster than the inside wheels) and undesirable at other times (when one wheel of the vehicle loses traction due to engagement with ice or mud on the roadway). As also discussed in the introductory portion, with the propeller shaft 30 disconnected from the engine, it is desirable to disconnect the propeller shaft also from the rotating wheels 10 so that the propeller shaft 30 is permitted to not rotate. The multiple modes for the differential including disconnect as between the wheels and propeller shaft; fixed common rotation of the wheels; and permitted differential rotation of the wheels; is provided by the invention as will now be explained.
As explained, axle 34 R is rotatable relative to stub axle 46 . A coupler 70 is provided on the end 44 of axle 34 R. A splined clutch ring 76 engages splines 74 of stub axle 46 and is slidable into an engagement also with splines 72 of coupler 70 . With the clutch ring 76 engaging both the stub axle 46 and axle 34 R, the stub axle 46 and axle 34 R are interlocked. With the clutch ring slid out of engagement with axle 34 R, the axle 34 R and stub axle 46 are free to rotate independently.
As can be seen from FIG. 2, the juncture of the axle 34 R and stub axle 46 is contained within case 52 . A flange 78 ,of the case defines a peripheral wall surrounding coupler 70 . The flange 78 is provided with inwardly directed splines 80 that project into the path of the slidable clutch ring 76 . Outwardly directed splines 82 on the clutch ring 76 engage spline 80 on flange 78 . In a first position, the clutch ring can be slid (to the left in FIG. 2) into engagement with stub axle 46 only. In a second position, it can be slid to the right into engagement also with the splines of the axle 34 R. In a third position, it can be slid further to the right into engagement with the splines 80 of case 52 while maintaining engagement with both the stub axle 46 and axle 34 R.
The effect of placing the clutch ring in the three positions will be described. With the clutch ring in the center position (engaging both stub axle 46 and axle 34 R and not case 52 ), the differential functions in the conventional manner. If the traction on the two wheels is equal, the propeller shaft drives case 52 which rotates gears 56 about axis 68 , and gears 56 through engagement with gears 42 , 48 commonly rotate both axles 34 L and 34 R. When turning the vehicle, because the inside wheel travels slower than the outside wheel, the rotational speed of the axles is unequal and the gears 56 will rotate about the pivot shafts 58 to accommodate the travel difference. Should one of the wheels lose traction (e.g., due to ice on the road), that wheel will spin freely and torque will be greatly reduced to both wheels.
By shifting the clutch ring to the far right position, the splines 82 of the clutch ring 76 engages splines 80 of the case 52 . The case 52 and axle 34 R (and stub axle 46 ) all rotate together. Shaft 58 rotates around axis 68 at the same rate as axle 34 R and thus the same as gear 48 . This prevents turning of gear 56 about its pivot shaft 58 and because gear 42 is engaged with gear 56 , axle 34 L similarly rotates with case 52 and axle 34 R. There can be no relative turning as between the wheels 10 in this mode.
By shifting the clutch ring to the far left, the clutch ring is out of engagement with both axle 34 R and case 52 and stub axle 46 rotates freely relative to both axle 34 R and case 52 . This mode is intended when the propeller shaft 30 is disconnected from the engine at the transfer case and it is desirable to allow the propeller shaft 30 to be passive. However, the wheels will rotate when driven which rotates axles 34 L and 34 R and if the axles are connected to the propeller shaft 30 , the propeller shaft will be driven by the wheels rather than the engine. By disconnecting the axle 34 R from the stub axle 46 , there is virtually no resistance to turning of gear 48 in either direction of rotation. Now axle 34 L (via gear 42 ) urges rotation of gear 56 about pivot shaft 58 and thus urges reverse rotation of gear 48 . Because stub shaft 46 offers no resistance to turning, it freely rotates which avoids forcing the case 52 to turn and allows propeller shaft 30 to thereby remain idle.
Actuation of Clutch Ring
Referring to FIGS. 2-6, it will be appreciated that clutch ring 76 is surrounded by the case 52 . Case 52 rotates at a different rate (at least some of the time) than clutch ring 76 and whatever actuation is provided for shifting the clutch ring, it has to accommodate this different rate of rotation. In this preferred embodiment, a plurality of shift posts 84 are protruded through openings in the case 52 and they are secured to a shift ring 86 . Shift ring 86 and shift posts 84 rotate with the case 52 but are axially slidable relative to the case 52 . Opposite the shift ring at the inner end of the posts 84 are shift springs 88 located on opposed sides of flange 90 of clutch ring 76 (see also FIGS. 4 and 5 ). Thus, axial movement of shift posts 84 urges axial movement of the clutch ring 76 . The springs 88 provide a bearing (similar to a shift fork) that accommodates relative rotation as between the clutch ring and shift posts. The springs 88 also accommodate engagement delay, i.e., should the splines of the clutch ring be misaligned with the splines 72 of the coupler 70 or the splines 80 of the case 52 , the springs 88 will flex and provide urging engagement and eventually engagement when the respective splines become aligned. Similarly when disengagement is attempted, the splines may be torque locked and disengagement prevented until release of the lock up. The springs will become loaded and provide disengagement upon release of the lock up.
Movement of the shift ring 86 is provided by shift shaft 92 which protrudes through carrier 50 . Carrier 50 doesn't rotate and thus the shift shaft 92 carries shift fork 94 which rides in a groove 96 provided in the periphery of the shift ring 86 . The shift fork provides a bearing for accommodating relative rotation of the shift ring 86 , i.e., the shift fork slides within the groove 96 .
The shift shaft 92 is provided with three positioning grooves 98 , one for each of the three positions of the clutch ring and a positioning ball 100 is urged into the respective grooves 98 to resistively permit movement out of the respective positions. In operation, the shift shaft may be moved between the positions (grooves 98 ), e.g., by a motor to shift the clutch ring. As explained, shifting of the clutch ring via the shift shaft is accomplished by accommodating the rotation of the shift ring via the shift fork 94 and then the relative rotation of the clutch ring via the springs 88 .
Those skilled in the art will likely conceive of various modifications and changes to the above preferred embodiment whole still incorporating the invention as determined from the claims appended hereto. | A differential for a wheel set provided with three modes of operation. A stub axle and wheel axle in combination provide drive torque to one wheel of the wheel set. A single wheel axle provides torque to the other wheel of the wheel set. The stub axle and wheel axle are releasably interconnected by a clutch ring and when connected provide conventional differential operation including equalized torque applied from a propeller shaft to the wheels of the wheel set. Alternatively the clutch ring can also provide connection to the differential casing to insure common rotation of the two wheels. In the third mode, the clutch ring does not connect any of the components and the non-resisted rotation of the stub axle effectively disconnects the wheel axles from the propeller shaft. An actuator provides actuation from a position at the exterior of the differential into and through the case to the clutch ring. The actuator includes bearing type interconnections to achieve axial movement even though the components have different rates of rotation. | 5 |
FIELD OF THE INVENTION
This invention relates to a stay damper which assists in the opening of a vehicle rear door and support of the door in a fully open sate.
BACKGROUND OF THE INVENTION
With respect to a stay damper which assists in the opening of a swing-type vehicle rear door, JPH10-115340A and JPH11-201210A published in 1998 and 1999 by Japan Patent Office, respectively, propose a locking mechanism which automatically locks contraction of the stay damper from an elongated position.
The stay damper comprises a cylinder, a piston accommodated in the cylinder, and a piston rod connected to the piston and projecting from the cylinder in an axial direction. The base of the cylinder is connected to a vehicle body while the projecting end of the piston rod is connected to the door. The cylinder is charged with gas, and the piston rod is biased to project from the cylinder according to a gas pressure.
The piston rod is covered by a cylindrical cover. The cover is supported by the projecting end of the piston rod such that the cover can overlap the outer circumference of the cylinder and swing about the projecting end of the piston within a limited range.
A leaf spring is interposed between the piston rod and the cover. The leaf spring biases the cover to swing about the projecting end of the piston such that the tip of the cover displaces in a lateral direction.
When the door is closed, the stay damper is in a contracted state in which the piston rod is in the cylinder except for the projecting end thereof and the cover overlaps the outer circumference of the cylinder.
In contrast, when the piston rod is elongated to its maximum length as the door is opened, the cover does not overlap the cylinder any more and the tip of the cover is removed from the outer circumference of the cylinder. In this state, the leaf spring causes the cover to swing about the projecting end of the piston rod, and as a result, the cover is inclined with respect to the cylinder. Thus, the tip of the cover is offset from the cylinder tip in the lateral direction.
When the contracting force is applied to the piston rod, the tip of the cover abuts against the cylinder tip, thereby preventing the piston rod from contracting.
According to the above construction of the stay damper, when the door is fully open, the stay damper is automatically brought into a locked state in which contraction thereof is prevented and thereafter the door is supported in the fully open position by the stay damper.
When the door is to be closed, a lock release operation is required which is accomplished by shifting the tip of the cover from the lock position against the force of the spring in a lateral direction. After performing the lock release operation, the cover no longer interferes with the contracting piston rod and the stay damper contracts smoothly under an appropriate resistance due to the pressure of the gas in the cylinder.
SUMMARY OF THE INVENTION
However, the prior art stay damper which automatically locks in the elongated position has the problem described below.
Specifically, if the operator of the door does not know about the lock release process, the operator may not be able to release the lock of the stay damper in the elongated position, and hence the operator may not be able to close the door. If the operator attempts to forcibly close the door in this state, the stay damper may break.
It is therefore an object of this invention to solve the above problem related to the release of a stay damper from a lock position by a simple construction.
In order to achieve the above object, this invention provides a stay damper comprising a cylinder in which a gas is charged, a piston rod which projects from the cylinder according to a pressure of the gas, and a stopper which locks contraction of the piston rod from an elongated position. The stopper displaces between a lock position which locks contraction of the piston rod and a release position which permits contraction of the piston rod, according to an operation force applied from outside. The stay damper further comprises a restricting member which holds the stopper in the lock position when the stopper is in the lock position and holds the stopper in the release position when the stopper is in the release position such that the stopper displaces only when the operation force is greater than a restriction force of the restriction member.
The details as well as other features and advantages of this invention are set forth in the remainder of the specification and are shown in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a stay damper according to this invention including a partial longitudinal sectional view of the same.
FIG. 2 is an enlarged longitudinal sectional view of a stopper according to this invention.
FIG. 3 is similar to FIG. 2 but shows the stopper in a locked state.
FIG. 4 is a cross-sectional view of the stopper taken along the line IV-IV in FIG. 2 .
FIG. 5 is a cross-sectional view of the stopper taken along the line V-V in FIG. 3 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 of the drawings, a stay damper interposed between a rear door and a vehicle body of a vehicle comprises a piston rod 2 projecting from a cylinder 1 . The cylinder 1 accommodates a piston connected to the piston rod 2 and is charged with a gas which biases the piston so as to cause the piston rod 2 to project from the cylinder 1 . The stay damper assists the rear door to open through the piston rod 2 which projects as a result of the expansion pressure of the gas. The rear door is arranged to swing horizontally about a vertical axis.
A ball joint 1 a is fixed to a base of the cylinder 1 . A ball stud fixed to the vehicle body is fitted in a spherical shaped recess of this ball joint 1 a such that the base of the cylinder 1 is connected to the vehicle body and the cylinder 1 is capable of swinging about the ball stud fixed to the vehicle body.
A ball joint 2 a is fixed to a projecting end of the piston rod 2 . A ball stud fixed to the rear door is fitted in a spherical shaped recess of this ball joint 2 a such that the projecting end of the piston rod 2 is connected to the rear door and the piston rod 2 is capable of swinging about the ball stud fixed to the rear door.
The piston rod 2 is covered by a cover 3 having a cylindrical shape. A base 3 a of the cover 3 is fitted to the projecting end of the piston rod 2 via a pin 2 c . More specifically, the pin 2 c penetrates a base 2 b of the ball joint 2 a and the base 3 a of the cover 3 in a lateral direction with respect to the direction of projection of the piston rod 2 such that the cover 3 can swing about the pin 2 c , or in other words, such that a tip of the cover 3 can displace in the lateral direction.
A stopper 10 is fixed to the tip of the cover 3 .
Referring to FIG. 2 , the stopper 10 comprises a cylindrical part 11 which has a substantially identical inner diameter to the cover 3 , and a holder 13 having an elongated circular cross-section. The cylindrical part 11 is fixed to the tip of the cover 3 . The holder 13 covers a tip 1 b of the cylinder 1 when the piston rod 2 is in the most elongated position.
Referring to FIG. 4 , the elongated circular shape corresponds to two semi-circles facing each other and connected by two straight parallel lines. The length of the minor axis of the holder 13 is equal to the inner diameter of the cylindrical part 11 . In other words, the shape of the holder 13 corresponds to the shape of the cylindrical part 11 elongated in the swing direction of the cover 3 .
Since the cross-sectional shapes of the holder 3 and the cylindrical part 11 are different, a step 11 a is formed between the cylindrical part 11 and the holder 3 .
On the opposite side of the holder 13 to the continuous part 13 b , a gap 13 a is formed.
On the inner circumference of the holder 13 , a pair of projections 12 are formed inward so as to hold the outer circumference of the tip 1 b of the cylinder 1 . Each of the projections 12 is in the form of a rib having a length almost equal to the length of the holder 3 in the direction of projection of the piston rod 2 . The pair of projections 12 are constructed in positions respectively facing a midpoint along a major axis of the elongated circular cross-section of the holder 3 .
According to the above construction, the stopper 10 elastically deforms so as to enlarge the gap 13 a when an outward force is applied to the holder 13 from within the inner side thereof. More specifically, in FIG. 4 , when a downward force is applied to the stopper 10 , the outer circumference of the tip 1 b of the cylinder 1 pushes the projections 12 outward so as to enlarge the gap 13 a . Due to this outward force exerted on the projections 12 , the holder 13 elastically deforms and then displaces downward as shown in FIG. 5 .
Herein, the relative position of the holder 13 and the tip 1 a shown in FIGS. 2 and 4 is referred to as a release position of the stopper 10 . The relative position of the holder 13 and the tip 1 a shown in FIGS. 3 and 5 is referred to as a lock position of the stopper 10 . The release position is a position in which the tip 1 b is adjacent to the gap 13 a , and the lock position is a position in which the tip 1 b is adjacent to an opposite part 13 b.
When the stopper 10 is in the release position, the piston rod 2 can intrude into the cylinder 1 , and when the stopper 10 is in the lock position, intrusion of the piston rod 2 into the cylinder 1 is blocked by the tip 1 b which interferes with the step 11 a.
The projections 12 function to hold the stopper 10 in both the release and lock positions. When the tip 1 b moves in the holder 13 from the release or lock position, it exerts a deforming pressure on the holder 13 via the projections 12 so as to enlarge the gap 13 a . The holder 13 exerts a resilient force on the tip 1 b via the projections 12 as a reaction force. This reaction force works as a holding force for holding the tip 1 b in the release position and the lock position respectively. When the stopper 10 is moved from the release position to the lock position, or vice versa, the tip 1 b must push the projections 12 aside so as to move through the space between the projections 12 . This tip holding function of the projections 12 is realized by the design of the holder 13 .
To ensure that the holder 3 deforms according to an outward force by the tip 1 b and exerts a resilient reaction force on the tip 1 b , it is necessary to constitute the stopper 10 , including the holder 13 , by an elastic material. In view of this requirement, the holder 13 is preferably constructed from a resin. For example, the cover 3 is manufactured by injection molding a plastic material and then press fitted onto the outer circumference of the tip of the cover 3 .
The stay damper constructed as described above is maintained in a contracted state when the rear door is closed. When an operator operates the rear door to open, gas pressure in the cylinder 1 assists the rear door to open via the piston rod 2 .
When the rear door reaches the fully open position, the stay damper reaches the most elongated position as shown in FIG. 1 . Here, the holder 13 of the stopper 10 faces the outer circumference of the tip 1 b of the cylinder 1 as shown in FIG. 2 . The operator of the rear door then applies a downward force on the stopper 10 in FIG. 2 . The tip 1 b of the cylinder 1 pushes the projections 12 aside and the holder 3 deforms. In this state, the tip 1 b of the cylinder 1 moves in the holder 13 . The tip 1 and the stopper 10 thus relatively displace from the release position shown in FIG. 4 to the lock position shown in FIG. 5 . In the lock position, the tip 1 b is held by the projections 12 and displacement of the tip 1 b from this position is restricted by the projections 12 . In the lock position, the tip 1 b interferes with the step 11 a of the cylindrical part 11 when the piston rod 2 contracts, thereby locking the contraction of the piston rod 2 . Hence, when the operator removes his/her hand from the rear door, the rear door is maintained in the fully open position.
In order to close the rear door in the fully open position, the operator first applies an upward force on the stopper 10 in FIG. 5 . According to this operation, the tip 1 b of the cylinder 1 again pushes the projections 12 aside so as to move through the space between the projections 12 . The tip 1 b and the stopper 10 then relatively displace from the lock position to the release position shown in FIG. 4 . Once the tip 1 b has reached the release position, displacement of the tip 1 b therefrom is again restricted by the projections 12 . Hence, the operator can remove his/her hand from the stopper 10 while keeping the stay damper in the release position. The piston rod 2 of the stay damper contracts smoothly according to a contraction force exerted by the closing operation of the rear door, performed by the operator.
If the operator did not push the stopper 10 to lock the contraction of the piston rod 2 when the rear door was fully opened, the rear door would not be maintained in the fully open position. When closing the rear door from the fully open position, in contrast, the operator pushes the stopper 10 in the direction opposite to the direction for locking so as to displace the stopper 10 to the release position.
Since the operator of the rear door performs the operation of the stopper 10 when the rear door is open, the operator of the rear door easily understand how to release the stopper 10 when he/she proceeds to close the rear door. This stay damper can, therefore, prevent an unfavorable situation in which the operator cannot close the rear door because the operator does not understand how to release the stopper 10 or in which the stay damper becomes defective due to an attempt to close the door forcibly while the stay damper is locked in the elongated position.
Further, according to this stay damper, since the projections 12 restrict the stopper 10 when it is in the release position as well as when it is in the lock position, the stopper 10 in either position does not move unless another external shifting force is applied, and hence unintended locking or releasing operations of the stopper 10 are prevented. Thus, the stay damper always operates as intended by the operator, and hence the rear door is opened and closed smoothly.
Although the invention has been described above with reference to a certain embodiment, the invention is not limited to the embodiment described above. Modifications and variations of the embodiment described above will occur to those skilled in the art, within the scope of the claims.
For example, in the embodiment described above, the projections 12 are formed in the shape of ribs, but the projections 12 may be formed in a semi-spherical shape. This shape reduces resistance to the relative displacement of the stopper 10 and the tip 1 b between the lock and release positions, thereby reducing the operation force required to operate the stopper 10 .
In the embodiment described above, unlike the prior art device, a spring is not provided between the piston rod 2 and the cover 3 . It is also possible, however, to provide a spring between the piston rod 2 and the cover 3 as long as the resilient force of the spring does not exceed the restriction force of the projections 12 , in order to balance the forces required for the locking and releasing operations of the stopper 10 or in order to intentionally differentiate these forces.
In the embodiment described above, the gap 13 a is provided in the holder 13 in order to promote elastic deformation of the holder 3 , but elastic deformation of the holder 13 can be achieved by other measures such as reducing the wall thickness of the holder 13 .
The embodiment describe above focuses on a stay damper for a rear door of a vehicle, but the stay damper according to this invention can also be applied to a hood for an engine room or a trunk lid of a vehicle as well as a vertical swing door of a hatchback style vehicle. | A stay damper comprises a cylinder ( 1 ) in which a gas is charged, a piston rod ( 2 ) which projects under a pressure of the gas in the cylinder ( 1 ), and a stopper ( 10 ) which locks contraction of the piston rod ( 2 ) in an elongated position. The stopper ( 10 ) displaces between a lock position which locks contraction of the piston rod ( 2 ) and a release position which permits contraction of the piston rod ( 2 ) according to directional operation forces applied by an operator. The stopper ( 10 ) comprises a restricting member ( 12, 13 ) which holds the stopper ( 10 ) in the lock position when it is in the lock position and holds the stopper ( 10 ) in the release position when it is in the release position. Since the locking operation of the stopper ( 10 ) is performed manually, the releasing operation thereof is easily understood by the operator. | 4 |
BACKGROUND
Field
The embodiments are generally directed to managing memory of a computing device, and more specifically to cache memory management of a computing device.
Background Art
A computing device generally includes one or more processing units (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a general purpose GPU (GPGPU), an accelerated processing unit (APU), or the like), that access a memory. Memory accesses are also called memory events, and an example includes a write event (i.e., a memory access request to write data to main memory). The processing units may execute programs that result in accessing data in the memory. Some data is accessed more frequently than others. Access time of this data can be improved by using different levels of cache between the processor and the memory.
BRIEF SUMMARY OF EMBODIMENTS
It is desirable to improve access time of frequently accessed data by using a knowledge of the data access frequency, when transferring data between cache and the memory.
Certain embodiments include a method comprising storing data in a block in a cache. The cache may comprise a block set and may be coupled to a buffer. The buffer may be further coupled to a memory that may comprise multiple pages. The method may include evicting a block value from the block set to the buffer based on its priority status and its recentness of use, when there is not enough space to store the data in the block set.
Certain embodiments include a method comprising storing data in a first block in a cache. The cache may comprise a block set and may be coupled to a buffer. The buffer may be further coupled to a memory that may comprise multiple pages. For the memory page, a block count may be calculated to be the count of blocks in the cache that have dirty values corresponding to the page. A priority status may be assigned to each block that has a dirty value with an address corresponding to the page when the page block count exceeds a first threshold. A second block value may be copied to the buffer in response to assigning the priority status to the second block. The block count may be decreased for the page by one, after copying the second block value. The priority status from each block that otherwise has a priority status may be removed when the block count reduces below a second threshold.
Further features and advantages of the embodiments, as well as the structure and operation of various embodiments, are described in detail below with reference to the accompanying drawings. It is noted that the embodiments are not limited to the specific embodiments described herein. Such embodiments are presented herein for illustrative purposes only. Additional embodiments will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein.
BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES
The accompanying drawings, which are incorporated herein and form part of the specification, illustrate the embodiments and, together with the description, further serve to explain the principles of the embodiments and to enable a person skilled in the pertinent art to make and use the embodiments. Various embodiments are described below with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout.
FIG. 1 illustrates a system, according to an embodiment.
FIG. 2 illustrates cache blocks, according to an embodiment.
FIGS. 3-9 illustrate flowcharts depicting methods, according to embodiments.
FIG. 10 illustrates an example of a table of priority information of cache blocks, according to an embodiment.
FIG. 11 illustrates an example computer system in which embodiments may be implemented.
The embodiments will be described with reference to the accompanying drawings. Generally, the drawing in which an element first appears is typically indicated by the leftmost digit(s) in the corresponding reference number.
DETAILED DESCRIPTION OF EMBODIMENTS
In the detailed description that follows, references to “one embodiment,” “an embodiment,” “an example embodiment,” etc. indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.
The term “embodiments” does not require that all embodiments include the discussed feature, advantage or mode of operation. Alternate embodiments may be devised without departing from the scope of the disclosure, and well-known elements of the disclosure may not be described in detail or may be omitted so as not to obscure the relevant details. In addition, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. For example, as used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
Computing devices process data and provide many applications to users. Example computing devices include, but are not limited to, mobile phones, personal computers, workstations, and game consoles. Computing devices use a central processing unit (“CPU”) to process data. A CPU is a processor which carries out instructions of computer programs or applications. For example, a CPU carries out instructions by performing arithmetical, logical and input/output operations. In an embodiment, a CPU performs control instructions that include decision making code of a computer program or an application, and delegates processing to other processors in the electronic device, such as a graphics processing unit (“GPU”).
A GPU is a processor that is a specialized electronic circuit designed to rapidly process mathematically intensive applications (e.g., graphics) on electronic devices. The GPU has a highly parallel structure that is efficient for parallel processing of large blocks of data, such as mathematically intensive data common to computer graphics applications, images and videos. The GPU may receive data for processing from a CPU or generate data for processing from previously processed data and operations. In an embodiment, the GPU is a hardware-based processor that uses hardware to process data in parallel.
Due to advances in technology, a GPU also performs general purpose computing (also referred to as GPGPU computing). In the GPGPU computing, a GPU performs computations that traditionally were handled by a CPU. An accelerated processing unit (APU) includes at least the functions of a CPU and a GPU. The GPU can be a GPGPU.
In an embodiment, a GPU includes one or more compute units (CUs) that process data. A compute unit (CU) includes arithmetic logic units (ALUs) and other resources that process data on the GPU. Data can be processed in parallel within and across compute units.
In an embodiment, a control processor on a GPU schedules task processing on compute units. Tasks include computation instructions. Those computation instructions may access data stored in the memory system of a computing device and manipulate the accessed data. In an embodiment, the data may be stored in volatile or non-volatile memory. An example of volatile memory includes random access memory (RAM). Examples of RAM include dynamic random access memory (DRAM) and static random access memory (SRAM). Volatile memory typically stores data as long as the electronic device receives power. Examples of non-volatile memory include read-only memory (ROM), flash memory, ferroelectric RAM (F-RAM), hard disks, floppy disks, magnetic tape, optical discs, etc. Non-volatile memory retains its memory state when the electronic device loses power or is turned off.
FIG. 1 illustrates a system 100 , according to an embodiment. In one example, system 100 includes a memory 102 , a buffer 106 , a cache 108 , and a controller 110 .
Memory 102 may include a page 104 . Page 104 is for example a portion of memory 102 . According to an embodiment, memory 102 may include one page or multiple pages. Buffer 106 may include a data block 112 . Data block 112 is for example a portion of buffer 106 . According to an embodiment, buffer 106 may include one data block or multiple data blocks.
According to an embodiment, memory 102 may be a Dynamic Random Access Memory (DRAM). According to an embodiment, cache 108 may be a Last Level Cache (LLC). According to an embodiment, buffer 106 maybe a DRAM row buffer.
In an embodiment, buffer 106 is connected to memory 102 and cache 108 . Buffer 106 may be connected to cache 108 via connection 107 . In another embodiment, buffer 106 is not connected to cache 108 via a direct connection. Data may be transferred between buffer 106 and cache 108 via the connection between controller 110 and buffer 106 and the connection between controller 110 and cache 108 .
Cache 108 may include a block set or multiple block sets 114 , and each block set may include one or more data blocks 116 . Buffer 106 may be configured to buffer data from cache 108 for writing to one or more memory pages 104 . Buffer 106 may hold one or more data blocks 112 .
In one example, it may be desirable to have, at one time, a high number of data blocks 112 in buffer 106 that are written to a same memory page. This is referred to as high locality in buffer 106 . High locality may result in lower energy consumption in writing to memory 102 because writing multiple data blocks to a single memory page consumes less energy than writing the multiple data blocks to different memory pages.
Controller 110 is connected to buffer 106 and cache 108 according to an embodiment. Controller 110 may be configured to evict data block 116 from cache 108 to buffer 106 . For example, controller 110 may select data block 116 , and evict data block 116 by copying a value in data block 116 to buffer 106 .
FIG. 2 illustrates a cache, e.g., cache 108 , according to an embodiment. In this example, cache 108 may include cache blocks 212 , 214 , and 216 . In another example, cache 108 may include block sets 218 , for example block set 0 , block set 1 , . . . , block set 63 .
In an embodiment, a block in cache 108 may correspond to a memory page in memory 102 , depending on an associativity of cache 108 with memory 102 . Associativity of a cache with a memory may show a correspondence between blocks in the cache to memory pages in the memory. In one example, each block in cache 108 may be associated with a corresponding memory page if cache 108 has full associativity with memory 102 . In other embodiments, a block in cache 108 may be associated with a corresponding one or more pages in memory 102 depending on associativity of cache 108 with memory 102 . In an embodiment, a set of blocks may be associated with a corresponding set of memory pages.
In one example, a block set 114 in cache 108 may include a Least Recently Used Block (LRU) and a Most Recently Used Block (MRU). An LRU may be a block that has new data written to it the longest time ago. An MRU may be a block that has new data written to it the shortest time ago. The blocks may be logically ordered from LRU in the most right hand side to MRU in a most left hand side. For illustration purposes FIG. 2 shows logical ordering of the blocks, according to an embodiment. For example block 212 in block set 0 is the LRU block and block 214 is the MRU block of block set 0 . Physical ordering of the blocks in a set may not be in the recency of use order.
FIG. 3 illustrates a flowchart depicting a method 300 , according to an embodiment. In one example, method 300 is used to write data, with a memory page address, to a cache. Solely for illustrative purposes, the steps illustrated in FIG. 3 will be described with reference to example system illustrated in FIG. 1 . It is to be appreciated in some instances not all steps need be performed, nor performed in the order shown.
In step 302 , cache 108 receives new data. In step 304 , controller 110 determines which block set of multiple block sets 218 in cache 108 will be used for storing the data. For example, the block set or multiple block sets are selected based on the memory page address corresponding to the new data.
FIG. 4 illustrates a flowchart depicting a method 400 , according to an embodiment. In one example, method 400 is used to write data to a cache or to evict data from the cache. Solely for illustrative purposes, the steps illustrated in FIG. 4 will be described with reference to example system illustrated in FIG. 1 , cache 108 illustrated in FIG. 2 , and method 300 illustrated in FIG. 3 . In an embodiment, controller 110 may perform some or all of the steps of method 400 . It is to be appreciated in some instances not all steps need be performed, nor performed in the order shown.
According to an embodiment, when there is new data ready to be written to cache 108 , at step 404 it is determined whether there is space available in a block set in block sets 218 for storing the new data. The block set for storing the new data may be determined in step 304 . If at step 404 it is determined space is available in the block set, at step 408 the new data may be written to one or more available data blocks in the block set and mark the blocks as dirty. For example if data is written to block set 0 in cache 108 , the new data may be written to block 216 , and block 216 is marked as dirty. In an embodiment, block 216 may remain dirty until the data in block 216 is evicted to buffer 106 . Evicting data may be copying or conveying the data to buffer 106 , for example. Evicting a data block may refer to evicting the data stored in the block. In an embodiment, if the new data already exists in a data block of cache 108 , the new data is overwritten the existing data block without requiring the eviction of another block.
According to an embodiment, if no space is available for writing the new data in the block set determined in step 304 , at step 406 at least one block is evicted from the block set. In an embodiment as many data blocks as necessary may be evicted so that there is space for storing the new data. After evicting as many blocks as necessary, the new data may be written in the available blocks and marked as dirty in step 408 .
In an embodiment, method 400 at step 410 may order the blocks in the block set such that the blocks that have new value written to them in step 408 , are ordered as the most recently used blocks, or in the MRU side of the block set. For example, referring to FIG. 2 , if new data value is written to block 216 in block set 0 of cache 108 , method 400 at step 410 orders the blocks in block set 0 such that block 216 is the Most Recent Used (MRU) block of block set 0 .
FIG. 5 illustrates a flowchart depicting a method 500 , according to an embodiment. In one example, method 500 is used to determine a priority of a block in a cache. Solely for illustrative purposes, the steps illustrated in FIG. 5 will be described with reference to example system illustrated in FIG. 1 and cache 108 illustrated in FIG. 2 . In an embodiment, controller 110 may perform some or all of the steps of method 500 . It is to be appreciated in some instances not all steps need be performed, nor performed in the order shown.
In an embodiment, method 500 determines priority for each memory page of memory 102 . As an example, memory page 104 is used to describe method 500 . Method 500 may be used for determining priority with respect to other memory pages in memory 102 .
In an embodiment, at step 503 a count of dirty blocks in cache 108 that have value with address corresponding to memory page 104 is determined. At step 504 , a determination is made whether the count is greater than a first threshold. If the count is greater than the first threshold, at step 506 priority is assigned to all of the blocks in cache 108 that have value with address corresponding to memory page 104 .
In an embodiment, if the count is less than the first threshold, at step 508 a determination is made whether the count is less than a second threshold. If the count is not less than the second threshold, 500 ends at step 514 .
In an embodiment, if the count is less than the second threshold, at step 510 , a determination is made whether the block or blocks that have data corresponding to memory page 104 are already assigned priority. If the blocks are not assigned priority the method may end at step 514 . In an embodiment, if the blocks having data corresponding to memory page 104 are assigned priority, at step 512 priority is removed from all of the blocks having value with address corresponding memory page 104 .
In an embodiment, the first and second thresholds are predetermined. In an embodiment, either or both of the first and second thresholds may be dynamically determined for each operation of method 500 . In another embodiment, the second threshold may be zero.
FIG. 6 illustrates a flowchart depicting a method 600 , according to an embodiment. In one example, method 600 is used to evict from cache 108 to buffer 106 . Solely for illustrative purposes, the steps illustrated in FIG. 6 will be described with reference to example system illustrated in FIG. 1 and cache 108 illustrated in FIG. 2 . In an embodiment, controller 110 may perform some or all of the steps of method 600 . It is to be appreciated in some instances not all steps need be performed, nor performed in the order shown.
In an embodiment, at step 604 a determination is made whether there is any block with priority status in a least recently used blocks sub-set of a block set in block sets 218 . For example the least recently used blocks sub-set may be the N blocks in the block set that were used the longest time ago, wherein N is an integer. In an embodiment, N may be dynamically determined each time method 600 is used. In an embodiment, N is predetermined.
If there is a block with priority in the least recently used blocks sub-set, at step 606 a least recently used block with priority in the block sub-set is evicted. The least recently used block with priority may be a block that has new data written to it the longest time ago and is assigned priority.
If there is no block with priority in the least recently used blocks sub-set, at step 608 the least recently used block in the block sub-set, regardless of priority, may be evicted. The least recently used block may be the block that has new data written to it the longest time ago.
FIG. 7 illustrates a flowchart depicting a method 700 , according to an embodiment. In one example, method 700 is used to store data in a cache. Solely for illustrative purposes, the steps illustrated in FIG. 7 will be described with reference to example system illustrated in FIG. 1 , and cache 108 illustrated in FIG. 2 . In an embodiment, controller 110 may perform some or all of the steps of method 700 . It is to be appreciated in some instances not all steps need be performed, nor performed in the order shown.
In an embodiment, at step 704 new data, corresponding to a memory page in memory 102 , is stored in a block in cache 108 and the block is marked as dirty. For example new data, corresponding to memory page 104 , is written in block 216 in cache 108 and block 216 is marked as dirty. In an embodiment, block 216 may remain dirty until the data in block 216 is evicted to buffer 106 , or the data block is otherwise marked as clean.
In an embodiment, at step 706 a count of dirty blocks in cache 108 that have value with address corresponding to the memory page of step 704 is determined. In an embodiment, at step 708 a determination is made whether the block count for the memory page of step 704 is greater than a third threshold. In an embodiment, if the count is greater than the third threshold, at step 710 a priority status is assigned to all the dirty blocks containing value with address corresponding to the memory page of step 704 . In an embodiment, if the count is not greater than the third threshold, 700 ends at step 712 .
FIG. 8 illustrates a flowchart depicting a method 800 , according to an embodiment. In one example, method 800 is used to copy a block value from a cache to a buffer. Solely for illustrative purposes, the steps illustrated in FIG. 8 will be described with reference to example system illustrated in FIG. 1 , and example cache 108 illustrated in FIG. 2 . In an embodiment, controller 110 may perform some or all of the steps of method 800 . It is to be appreciated in some instances not all steps need be performed, nor performed in the order shown.
In embodiments, method 800 copies a block value from cache 108 to buffer 106 , such that there will be high locality in the buffer. According to an embodiment, at step 804 a determination is made whether there is bandwidth available on a connection 107 between cache 108 and buffer 106 . In example embodiments, transmitting a block value between cache 108 to buffer 102 consumes bandwidth on connection 107 . In an embodiment, a block value may be transmitted in addition to current data being transmitted on connection 107 , when there is enough bandwidth available for the block value.
In an embodiment, if there is not enough bandwidth available for transmitting a cache block value on connection 107 , 800 ends at step 814 . In an embodiment, if there is enough bandwidth available for transmitting a block value on connection 107 , at step 806 a determination is made whether there is a block with priority status in cache 108 . In an embodiment, if at step 806 a determination is made that there is no block with priority status in cache 108 , 800 ends at step 814 .
In embodiments, buffer 106 is not connected to cache 108 via a direct connection 107 , as described with respect to FIG. 1 . Steps of method 800 that use connection 107 may be performed using the connection between controller 110 and buffer 106 and the connection between controller 110 and cache 108 .
In an embodiment, if there is a block with priority status in cache 108 , at step 808 value of a block with priority status is transmitted to the buffer 106 . In an embodiment at step 808 value of a least recently used block with priority status is transmitted to buffer 106 . In an embodiment, at step 808 value of a block with priority status within a first number of least recently used blocks, is transmitted to buffer 106 . In an embodiment, a block is within a first number of least recently used blocks, when the block is among the first number of blocks that have data written to them the longest time ago.
In an embodiment the first number is predetermined. In another embodiment the first number is dynamically determined before executing method 800 .
In an embodiment at step 810 a determination is made whether the block count for the corresponding memory page to the copied block is less than a fourth threshold. In an embodiment, if the block count is not less than the fourth threshold, 800 ends at step 814 . In an embodiment, if the block count is less than the fourth threshold, at step 812 the priority status from all the blocks corresponding to the memory page of step 810 is removed.
In an embodiment, the third and fourth thresholds are predetermined. In another embodiment, the third and fourth threshold may be dynamically determined for each operation of method 800 . In an embodiment, the fourth threshold may be zero.
FIG. 9 illustrates a flowchart depicting a method 900 , according to an embodiment. In one example, method 900 is used to delete or clean a block in a cache. Solely for illustrative purposes, the steps illustrated in FIG. 9 will be described with reference to example system illustrated in FIG. 1 . In an embodiment, controller 110 may perform some or all of the steps of method 900 . It is to be appreciated in some instances not all steps need be performed, nor performed in the order shown.
In an embodiment, at step 904 , when a block value is copied to buffer 106 , the block is marked as clean. In embodiments, when a block is marked as clean it is not dirty any more.
In an embodiment, at step 906 a determination is made whether the cleaned block at step 904 is within a second number of least recently used blocks within a block set that includes the cleaned block. In an embodiment, if the block is not within the second number of least recently used blocks, 900 ends at step 910 .
In an embodiment, if the cleaned block is within the second number of least recently used blocks, at step 908 the cleaned block value is deleted and the block becomes available for storing new value.
In an embodiment the second number is predetermined. In another embodiment, the second number is dynamically determined before executing method 900 . In an embodiment, the second number is zero.
Embodiments may use approximations of least recently used blocks, such as “Pseudo Least Recently Used” (pLRU) instead of least recently used blocks described above.
FIG. 10 illustrates a table according to an embodiment. In this example, table 1000 is used to store priority information for all cache blocks having value with address corresponding to each memory page. Solely for illustrative purposes, table 1000 will be described with reference to example system illustrated in FIG. 1 .
According to an embodiment, table 1000 may include a row corresponding to each memory page in memory 100 . In an embodiment table 1000 includes a memory page address column, a dirty block count column, and a priority bit column. According to an embodiment, a first column in a row includes an address of a memory page, a second column in the row includes a count of all dirty blocks having value with address corresponding to the memory page, and a third column in the row includes a priority bit. According to an embodiment, when methods 500 , 700 , or 800 determine priority for all the blocks having dirty value with address corresponding to a memory page, the priority bit of a row corresponding to the memory page in table 1000 is set to “1” to show priority.
For example, in table 1000 page address 1002 indicates memory page address 0 . Dirty block count 1004 indicates that there are 16 dirty blocks having value with address corresponding to memory page address 0 . And “1” in priority bit 1006 indicates that method 500 , 700 , or 800 has determined that all the blocks having value with address corresponding to memory page address 0 have priority.
Various aspects of the disclosure can be implemented by software, firmware, hardware, or a combination thereof. FIG. 11 illustrates an example computer system 1100 in which some embodiments, or portions thereof, can be implemented as computer-readable code. For example, the methods 300 - 900 , of FIGS. 3 through 9 can be implemented in system 1100 . Various embodiments are described in terms of the example computer system 1100 . After reading this description, it will become apparent to a person skilled in the relevant art how to implement the embodiments using other computer systems and/or computer architectures.
Computer system 1100 includes one or more processors, such as processor 1104 . Processor 1104 can be a special purpose or a general purpose processor.
Computer system 1100 also includes a main memory 1108 , such as random access memory (RAM) such as memory 102 of FIG. 1 , and may also include a secondary memory 1110 . Secondary memory 1110 may include, for example, a hard disk drive 1112 , a removable storage drive 1114 , and/or a memory stick. Removable storage drive 1114 may comprise a floppy disk drive, a magnetic tape drive, an optical disk drive, a flash memory, or the like. The removable storage drive 1114 reads from and/or writes to a removable storage unit 1118 in a well-known manner. Removable storage unit 1118 may comprise a floppy disk, magnetic tape, optical disk, etc. that is read by and written to by removable storage drive 1114 . As will be appreciated by persons skilled in the relevant art(s), removable storage unit 1118 includes a computer usable storage medium having stored therein computer software and/or data.
In alternative implementations, secondary memory 1110 may include other similar means for allowing computer programs or other instructions to be loaded into computer system 1100 . Such means may include, for example, a removable storage unit 1122 and an interface 1120 . Examples of such means may include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an EPROM, or PROM) and associated socket, and other removable storage units 1122 and interfaces 1120 that allow software and data to be transferred from the removable storage unit 1122 to computer system 1100 .
Computer system 1100 may also include a communications interface 1124 . Communications interface 1124 allows software and data to be transferred between computer system 1100 and external devices. Communications interface 1124 may include a modem, a network interface (such as an Ethernet card), a communications port, a PCMCIA slot and card, or the like. Software and data transferred via communications interface 1124 are in the form of signals that may be electronic, electromagnetic, optical, or other signals capable of being received by communications interface 1124 . These signals are provided to communications interface 1124 via a communications path 1126 . Communications path 1126 carries signals and may be implemented using wire or cable, fiber optics, a phone line, a cellular phone link, an RF link or other communications channels.
In this document, the terms “computer program medium” and “computer usable medium” are used to generally refer to media such as removable storage unit 1118 , removable storage unit 1122 , and a hard disk installed in hard disk drive 1112 . Signals carried over communications path 1126 can also embody the logic described herein. Computer program medium and computer usable medium can also refer to memories, such as main memory 1108 and secondary memory 1110 , which can be memory semiconductors (e.g. DRAMs, etc.). These computer program products are means for providing software to computer system 1100 .
Computer programs (also called computer control logic) are stored in main memory 1108 and/or secondary memory 1110 . Computer programs may also be received via communications interface 1124 . Such computer programs, when executed, enable computer system 1100 to implement the embodiments as discussed herein. In particular, the computer programs, when executed, enable processor 1104 to implement the disclosed processes, such as the steps in the method 300 of FIG. 3 , method 400 of FIG. 4 , method 500 of FIG. 5 , method 600 of FIG. 6 , method 700 of FIG. 7 , method 800 of FIG. 8 , or method 900 of FIG. 9 , as discussed above. Accordingly, such computer programs represent controllers of the computer system 1100 . Where the embodiments are implemented using software, the software may be stored in a computer program product and loaded into computer system 1100 using removable storage drive 1114 , interface 1120 , hard drive 1112 or communications interface 1127 . This can be accomplished, for example, through the use of general-programming languages (such as C or C++). The computer program code can be disposed in any known computer-readable medium including semiconductor, magnetic disk, or optical disk (such as, CD-ROM, DVD-ROM). As such, the code can be transmitted over communication networks including the Internet and internets. It is understood that the functions accomplished and/or structure provided by the systems and techniques described above can be represented in a core (such as a processing-unit core) that is embodied in program code and may be transformed to hardware as part of the production of integrated circuits. This can be accomplished, for example, through the use of hardware-description languages (HDL) including Verilog HDL, VHDL, Altera HDL (AHDL) and so on, or other available programming and/or schematic-capture tools (such as, circuit-capture tools).
Embodiments are also directed to computer program products comprising software stored on any computer useable medium. Such software, when executed in one or more data processing device, causes a data processing device(s) to operate as described herein. Embodiments employ any computer useable or readable medium, known now or in the future. Examples of computer useable mediums include, but are not limited to, primary storage devices (e.g., any type of random access memory), secondary storage devices (e.g., hard drives, floppy disks, CD ROMS, ZIP disks, tapes, magnetic storage devices, optical storage devices, MEMS, nanotechnological storage device, etc.), and communication mediums (e.g., wired and wireless communications networks, local area networks, wide area networks, intranets, etc.).
It is to be appreciated that the Detailed Description section, and not the Summary and Abstract sections, is intended to be used to interpret the claims. The Summary and Abstract sections may set forth one or more but not all exemplary embodiments as contemplated by the inventor(s), and thus, are not intended to limit the disclosure and the appended claims in any way.
The disclosure has been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed.
The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present disclosure. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance.
The breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents. | To efficiently transfer of data from a cache to a memory, it is desirable that more data corresponding to the same page in the memory be loaded in a line buffer. Writing data to a memory page that is not currently loaded in a row buffer requires closing an old page and opening a new page. Both operations consume energy and clock cycles and potentially delay more critical memory read requests. Hence it is desirable to have more than one write going to the same DRAM page to amortize the cost of opening and closing DRAM pages. A desirable approach is batch write backs to the same DRAM page by retaining modified blocks in the cache until a sufficient number of modified blocks belonging to the same memory page are ready for write backs. | 8 |
FIELD OF THE INVENTION
[0001] This invention relates to products, methods and apparatus for solid state refrigeration systems such as those employing the magnetocaloric or electrocaloric effect.
BACKGROUND TO THE INVENTION
[0002] Typically a cryogenic adiabatic demagnetisation refrigerator (ADR) is used for achieving very low temperatures, for example below 1 K, potentially below 1 mK after initial cooling to between 1 K to 4 K using liquid helium or liquid cryogen free cooling techniques. Broadly speaking a magnetocaloric material is employed, typically a paramagnetic material with a high magnetic susceptibility and large entropy change under the application of magnetic fields. This is held at a constant temperature whilst a field is applied and then the field is removed adiabatically allowing the magnetic moments to randomise resulting in a reduction in temperature. The magnetocaloric material is generally a paramagnetic salt such as CMN (cerium magnesium nitrate).
[0003] In principle a solid state refrigerator may be based on an electrocaloric or thermoelectric material rather than a magnetocaloric material. The electrocaloric refrigeration method has a similar underlying cooling principle, related to electric rather than magnetic degrees of freedom and alignment of internal electric polarisation. At present, however, suitable electrocaloric materials are less well developed for a working device although alkali halides such as KCl doped with polarisable impurities such as Li + , OH − and CN − show promise.
[0004] ADR based technology is employed, inter alia, for space applications (for example J-M Duval et al, ‘A miniature continuous adiabatic de-magnetisation refrigerator with compact shielded super conducting magnets’, in Millimetre and Sub-Millimetre detectors for Astronomy II, Ed J Zmuidzinas et al, SPIE Vol 5498 pp 802-811); further background prior art can be found in Paul A Bromiley, PhD thesis, University of London 1999, ‘Development of an adiabatic de-magnetisation refrigerator for use in space’.
[0005] Typically the magnetocaloric material is provided within a cooling ‘pill’, generally a metal cylinder within which crystals of the material are grown. The cylinder may be sealed to inhibit dehydration of the salt. In the pill of Duval et al the salt is grown in a brass can containing copper wires braised to a thermal bus; in that of Bromily's thesis a thermal bus is employed consisting of a set of fins connected to a central pillar. These designs, however, have significant disadvantages. For example the approach of Bromiley involves machining components from solid which is very expensive. In both designs it can take a period of days to weeks to grow the salt crystals, and short pill lifetime and relatively poor thermal conductivity are also problems.
[0006] The heat switch in an ADR can also be a source of design difficulties—US2003/0041600 describes an electro-mechanical heat switch but this is complicated, expensive and cumbersome to use in practice.
[0007] Other difficulties include sealing the pill to inhibit dehydration, particularly in a vacuum, and under large changes in temperature. This is problematical because epoxy seals tend to crack upon repeated thermal cycling whilst welded seals are expensive and difficult to produce without compromising the performance of the refrigerant through overheating.
[0008] There is thus a need for improvements in the design of adiabatic solid-state magnetocaloric and electrocaloric refrigerators.
SUMMARY OF THE INVENTION
[0009] According to a first aspect of the invention there is therefore provided a refrigeration pill for a solid-state magnetocaloric or electrocaloric refrigerator, the pill having longitudinal and transverse axes, said pill comprising a housing containing: an internal mounting structure divided along said longitudinal axis into first and second mounting parts; wherein each of said mounting parts comprises a thermally conducting metal skeleton defined by the respective said mounting part; and wherein regions within said housing between elements of said skeleton comprise magnetocaloric or electrocaloric material.
[0010] Embodiments of this structure enable the crystallisation of materials from a solution to proceed nearly an order of magnitude faster than with conventional approaches.
[0011] In embodiments the pill comprises two half-cylinders split along the cylinder length and the crystallisation may therefore be carried out for the two half cylinders at the same time, and in addition with the crystal growth along a direction normal to the cylinder axis (the short direction) rather than along the cylinder axis (the long direction). The crystallisation time along the short direction can be nearly an order of magnitude faster than for growth along the long direction. Moreover, the structure facilitates monitoring the progress of crystal growth, for example to ensure that the crystals grow systematically in the preferred direction substantially without voids. In addition for some materials, for example CMN (cerium magnesium nitrate), the longitudinally split structure enables growth of the crystals perpendicular to the longitudinal axis. This is a better alignment for a typical magnetic field direction within a refrigerator (which is along the longitudinal axis). Still further, crystals grown in such a structure bond well to the skeleton (and housing, where grown in the housing) without the need for glue or the like which other techniques have required.
[0012] Various types of metal skeleton may be employed and during the growth of the crystals, for example of a paramagnetic salt; the presence of the housing is optional. The outer housing may be in two parts and present during crystal growth or the two mounting parts may be assembled within a single outer, preferably cylindrical housing after crystal growth.
[0013] In one embodiment the metal skeleton may comprise a volume-filling metal mesh or woven or helical arrangement of wires attached to a thermal contact, for example welded to a screw-thread, at either end of the pill. In other embodiments the skeleton may comprise a set of wires running longitudinally between end plates, again each with a thermal contact. The wires may be copper, preferably gold plated to inhibit corrosion, or solid silver.
[0014] In one particularly preferred embodiment the skeleton comprises a set of transverse metal fins, for example half-discs spaced at intervals along the longitudinal axis. In embodiments where there are two housing portions the skeleton may lie within and preferably in thermal contact with each housing portion, for example each half-cylinder. As well as facilitating a good heat flow within the pill this arrangement also facilitates rapid crystal growth and reduces corrosion. In a preferred embodiment the metal fins comprise silver fins.
[0015] In a further embodiment, which may optionally be combined with a skeleton as previously described, the skeleton comprises metal filaments or dendrites within the magnetocaloric material. In embodiments these filaments or dendrites are grown within the crystal structure of the magnetocaloric material as the material crystallises, for example by providing a suspension of silver powder which floats on top of or permeates the solution from which the material is crystallising or otherwise deposited. This structure has been found to be particularly effective at improving thermal conductivity, providing one or two orders of magnitude improvement in conductivity. In embodiments the filaments or dendrites comprise silver, for good conductivity and corrosion resistance, but other metals may also be employed.
[0016] Where an electrocaloric material is employed the metal skeleton may be used to provide connections to what are effectively plates/electrodes of one or more capacitors within the pill. Here ‘plates’ is used in a functional sense without implying any particular structural configuration, but nonetheless a skeleton comprising a set of metal fins or half-discs is preferred with an electrocaloric material. That is because this provides an efficient multi-layer capacitor-type structure which can be used to apply an electric field to the material. In such an arrangement the fins/discs may be supported on one or more rods running parallel to the longitudinal axis and every alternate fin/disc electrically isolated from each other. Conveniently a pair of rods may be used to provide interleaved electrical connections to the fins/plates. In embodiments a plastic housing may suffice, particularly where the electrocaloric material is relatively non-volatile.
[0017] As previously mentioned, in some preferred embodiments the magnetocaloric/electrocaloric material is grown as a crystal within each of the mounting parts with an axis of growth substantially perpendicular to the longitudinal axis. This may be achieved by resting each mounting part within a crystal growth trough, with the longitudinal axis substantially horizontal, optionally seeding the crystal growth at the bottom. The liquid-solid interface then grows upwards from the bottom on each mounting part upwards. The growth interface may be perpendicular to one axis of the crystals. For some paramagnetic salts the direction of field with respect to that of crystal growth may be less important but for other materials, for example CMN (and especially those used in achieving particularly low temperatures), it is preferable that the field is applied at right angles to the direction of crystal growth—that is with a component along the longitudinal axis with a major component. Growing the material as a crystal is not, however, essential to producing embodiments of the pill and in other approaches the magnetocaloric or electrocaloric material may, for example, simply be pressed.
[0018] In embodiments the two mounting parts may be sealed within an outer housing such as an outer cylinder to protect the pill from damage/dehydration/decomposition. The housing is preferably metal for a magnetocaloric material but is preferably insulating, for example plastic, for an electrocaloric material. In embodiments the outer housing or cylinder may be sealed to a flange at either end of the pill, preferably using O-rings such as indium O-rings. This avoids the problems associated with welded joints and epoxy found with prior art arrangements.
[0019] In a related aspect the invention provides a refrigeration pill for a solid-state magnetocaloric or electrocaloric refrigerator, in particular an adiabatic magnetocaloric or electrocaloric refrigerator, the pill having longitudinal and transverse axes, said pill comprising: a longitudinal housing and a pair of pill end stops, one towards either end of the housing; wherein said end stops carry a thermally conducting metal skeleton extending longitudinally between them; wherein said end stops are sealed against a (circumferential) wall of said housing; and wherein regions within said housing between elements of said skeleton comprise magnetocaloric or electrocaloric material.
[0020] The skilled person will recognise that features of the previously described aspect of the invention are also applicable to this aspect, and vice-versa.
[0021] Thus in some preferred embodiments the pill has an end stop or cap which comprises a sealing mechanism. The sealing mechanism may comprise a longitudinally moveable sealing part or plate and a mechanism, for example a screw thread and nut, to force the sealing part towards the end stop. The end stop and sealing part define a ring-shaped region or groove adjacent to an internal surface of the circumferential wall of the housing. A sealant is provided within this region, for example indium or sapphire loaded epoxy. When the sealing part is forced towards the end stop the sealant is forced outwards to form a seal against the internal surface of the circumferential wall of the housing. A mounting post for the pill may provide a screw thread of the sealing mechanism.
[0022] In embodiments the metal skeleton comprises a set of wires or mesh extending longitudinally between the end stops. The wires or mesh may be fabricated from copper or gold-plated copper.
[0023] The invention also provides a method of manufacturing a refrigeration pill for an adiabatic solid-state magnetocaloric or electrocaloric refrigerator, the method comprising: providing a mounting structure in two parts divided along a longitudinal axis of said refrigeration pill, said mounting structure having a metal skeleton; growing a crystal structure of magnetocaloric or electrocaloric material on the skeleton of each said mounting part; and assembling said mounting parts to manufacture said refrigeration pill.
[0024] The skeleton may be an internal skeleton and/or an exoskeleton—for example a mounting part may define a trough within which the crystal material is grown.
[0025] The invention further provides a method of manufacturing a refrigeration pill for an adiabatic solid-state magnetocaloric or electrocaloric refrigerator, the method comprising growing a crystal structure of magnetocaloric or electrocaloric material around said metal skeleton; in particular wherein said growing is performed with said longitudinal axis of said housing part substantially horizontal.
[0026] A refrigeration pill, in particular as described above, may be incorporated into a cryogenic refrigerator such as an adiabatic solid-state magnetocaloric or electrocaloric refrigerator. In such an arrangement a first refrigeration stage is preferably a metal plate cooled by a self-contained refrigeration stage (“the cryogenic platform”) employing either liquid helium or a liquid cryogen free system, such as a pulse tube cooler or a Gifford-McMahon cooler. A second refrigeration stage comprises the refrigeration pill and this is thermally connected to the first stage via a heat switch so that the solid-state refrigeration pill can be cooled by the first stage and then thermally decoupled from the first stage for a further stage of cooling of the sample. In some preferred arrangements, but not essentially, the heat switch is a mechanical heat switch. However there are difficulties in providing a mechanical heat switch operable at low temperatures which is suitable for use in a relatively light weight structure whilst still having a low on-resistance.
[0027] According to a further related aspect of the invention there is therefore provided a refrigeration system comprising: a first refrigeration stage, in particular a liquid helium-4 refrigerator or a liquid-cryogen free refrigerator (e.g. a pulse tube cryocooler or Gifford-McMahon cryocooler) or a liquid-cryogen free refrigerator combined with a pumped liquid helium-4 1K cooling system or helium-3 cooling system; a second refrigeration stage comprising a solid-state refrigerator (SSR), said SSR comprising a refrigeration pill; and a heat switch, in particular a mechanical heat switch, thermally coupling said first and second refrigeration stages and arranged to selectively decouple said thermal coupling. In preferred embodiments said mechanical heat switch comprises first and second metal contacts to said first and second refrigeration stages respectively, and an actuator moveable longitudinally between a first coupling position in which said heat switch provides a thermal path between said contacts and a second, decoupled position in which said thermal path is broken; wherein said mechanical heat switch further comprises a set of one or more arms, moveable radially to thermally couple and decouple said metal contacts, and wherein said longitudinal movement of said actuator provides a camming action to move said one or more arms radially to operate said heat switch.
[0028] The first refrigeration stage is preferably a liquid helium-4 refrigerator system or a liquid-cryogen free refrigerator system (e.g. a pulse tube cryocooler or Gifford-McMahon cryocooler), or either of these combined with a pumped liquid helium-4 cooling system, or a liquid-cryogen free refrigerator optionally combined with a pumped liquid helium-4 cooling system, or a helium-3 cooling system.
[0029] In some preferred embodiments the heat switch comprises a coronet-shaped switching portion mounted on a collar or similar around which the set of arms is disposed circumferentially. A camming feature, which may be located either inside or outside the arms, is moved longitudinally to either push the arms outwards or, in an alternative arrangement, push the arms inwards, to make thermal contact with one of the metal contacts. In some embodiments the actuator is mounted on a screw arrangement so that rotation of the screw moves the actuator longitudinally. This type of arrangement can apply a very large outwards (or inwards) radial force, for example of some hundreds of pounds, within the context of a simple lightweight structure. This can thus achieve a very low thermal-on resistance and provide very good thermal isolation when off. In one embodiment one or both of the contacts comprises gold plated metal; in one embodiment the coronet of arms is located within a cup, the arms being moveable radially outwards to contact an inner surface of the cup, which forms a further metal (thermal) contact for the switch.
[0030] The invention also provides a removable cooling assembly for a refrigeration system comprising first and second refrigeration stages as previously described, connected by a mechanical heat switch, the second refrigeration stage incorporating a sample region (the region where a device or material under test may be placed). In embodiments the sample region is adjacent the heat switch and the refrigeration pill of the second refrigeration stage is beyond the sample region in a direction away from the heat switch, the first refrigeration stage being connected to the heat switch. This provides an assembly which facilitates access to the sample space and which has a room-temperature end and region at which the temperature is less than 1 K, and in embodiments the assembly may be self-contained and removable as a unit from the cryogenic platform/refrigeration system (“the sample insert”). The arrangement also facilitates multi-stage cooling—for example a third refrigeration stage may be located along the longitudinal axis beyond the second refrigeration stage (going away from the sample region), connected to the second stage via a further heat switch. The skilled person will recognise that in these arrangements the heat switch may be of any suitable type including, for example, a mechanical heat switch, a superconducting heat switch, a gas heat switch or a piezoelectric heat switch.
[0031] In a further related aspect the invention provides a mechanical heat switch to switch a thermal coupling between first and second stages, wherein said mechanical heat switch comprises first and second metal contacts to said first and second stages (in embodiments first and second heat sources/sinks) and an actuator moveable longitudinally between a first coupling position in which said heat switch provides a thermal path between said contacts and a second, decoupled position in which said thermal path is broken; wherein said mechanical heat switch further comprises a set of one or more arms, moveable radially to thermally couple and decouple said metal contacts, and wherein said longitudinal movement of said actuator provides a camming action to move said one or more arms radially to operate said heat switch.
[0032] The invention also provides a superconducting heat switch comprising first and second metal thermal contacts connected by a sheet of foil made out of a superconducting material such as lead or tin. When the foil is in its normal metallic state, which may be achieved by applying a large enough magnetic field, the heat switch is closed. When in the superconducting state the heat switch is open.
[0033] Preferably the metal thermal contacts are mechanically supported and attached to each other by a thermally insulating housing, typically made out of a plastic material; preferably the lead or tin foil has an impurity level of less than 10 ppm.
[0034] The invention further provides an adiabatic solid-state refrigeration system comprising: two solid-state refrigeration stages each thermally coupled to the same sample chamber, each comprising an adiabatic solid-state refrigerator (ASR), said ASR comprising a refrigeration pill, each with a respective controllable magnetic/electric field generator; and a control system to control removal of said magnetic/electric field from each of said pills sequentially to control cooling of said sample chamber.
[0035] In an adiabatic demagnetisation refrigerator the control system may control removal of a magnetic field/demagnetisation of a pill; where the pill contains electrocaloric material an electric field may be removed from the pill, for example by reducing or removing a voltage across the pill.
[0036] Such a system may operate in series, to facilitate reaching a lower base temperature, or in parallel, to provide substantially continuous cooling, or may be configurable for either mode of operation. In either case it is practically convenient to arrange the solid-state refrigeration stages physically in series longitudinally with, for example, a copper rod connecting each longitudinally to the sample chamber.
[0037] In a series configuration the sequential control is configured to cool the sample chamber successively with a first then a second of the solid-state refrigeration stages. This may be extended to further refrigeration stages. The solid-state refrigeration stages may be thermally coupled in series via one or more heat switches such as those previously for example, a mechanical or superconducting heat switch, in particular as previously described, or a gas or a piezoelectric heat switch.
[0038] In a parallel configuration, in particular for continuous sample cooling, the solid-state refrigeration stages are thermally coupled in parallel to said sample chamber each via a respective heat switch. The system further comprises a first refrigeration stage, for example a metal plate cooled by a liquid helium-4 refrigerator or a liquid-cryogen free refrigerator (e.g. a pulse tube cryocooler or Gifford-McMahon cryocooler), or either of these combined with a pumped liquid helium-4 1 K cooling system or helium-3 cooling system. Each of the solid-state refrigeration stages may then be thermally coupled to the first refrigeration stage via a further respective heat switch. The control system may then be configured to control the heat switches and the magnetic/electric field (as mentioned previously) such that one of said solid-state refrigeration stages is cooling the sample chamber whilst the other is (being electrically or magnetically polarised and) being cooled by the first refrigeration stage, and vice versa. Thus, designating the first-second stage heat switches “input” heat switches and those to the sample chamber “output” heat switches, the input heat switch for the first pill is on whilst its output switch is off and at the same time as the input heat switch for the second pill is on whilst its output switch is on. During this interval and the field is applied to the first pill and removed from the second pill. The on/off configurations of the heat switches are then reversed and the field is applied to the second pill and removed from the first pill.
[0039] In a still further aspect the invention provides an adiabatic solid-state refrigeration system comprising two separate or linked stages, a first, cryogenic device cooling stage, and a second sample cooling stage; and a cryogenic device comprising an adiabatic solid-state refrigerator (ASR), said ASR comprising a refrigeration pill, in particular as described above, and a system to maintain said pill in an electric or magnetic field; wherein said first, cryogenic device cooling stage comprises a first refrigeration stage for cooling said cryogenic device; wherein said second, sample cooling stage comprises said cryogenic device thermally coupled to a sample platform for cooling a sample; wherein said electric or magnetic field is removeable from said pill when said cryogenic device for cooling said sample; and wherein said cryogenic device is thermally coupled to said sample platform through a boundary such that heat flows radially outwards from said sample platform.
[0040] In some embodiments the sample may be held within a removeable vacuum tube defining the boundary through which heat flows radially. In embodiments a housing for the first and second cooling stages defines a second vacuum space containing the vacuum tube and both the first and second cooling stages. In embodiments, the cryogenic device may be displaced longitudinally from the sample platform and coupled to the sample platform via a thermally conductive path. In embodiments at least one heat switch is provided between the cryogenic device and the first, cryogenic device cooling stage.
[0041] It is particularly convenient if the pill comprises electrocaloric or thermoelectric material since in this case it is straightforward to maintain/remove the electric field from the pill as required. In particular where a solenoid is used to maintain the magnetic field in an adiabatic demagnetisation system, this restricts physical access to the cooled region to directions along the axis of the solenoid—but the refrigeration system may then be configured with a thermal path between the cryogenic device (ASR) and the sample platform boundary. By contrast where an electric field is used to facilitate refrigeration, other directions, for example the radial direction, may be used to thermally connect the sample chamber and cryogenic device with one another.
[0042] Thus in the case of any of magneto-caloric, electro-caloric or thermoelectric solid-state coolers, there may be provided a facility for the refrigeration to be carried out horizontally away from the sample holder cryogenic insert, thermal contact being made through a boundary. In embodiments this results in both cooling stages being carried out on the platform and the sample holder simply being slid in to the cold region and mounted on a sample platform when needed. Thermal contact may then be made going radially out from the sample platform through the vacuum tube containing the sample space to the base temperature plate of the cryogenic platform. Such an arrangement may be employed with multiple cryogenic devices (ASRs), connected to operate in series, in parallel, or both. Thus, for example, each may have one or both of an input heat switch (coupling the cryogenic device to the first, cryogenic device cooling stage) and an output heat switch (coupling the cryogenic device to the sample platform).
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] These and other aspects of the invention will now be further described, by way of example only, with reference to the accompanying figures in which:
[0044] FIG. 1 shows a multi-plate half-cylinder assembly for a magnetic refrigeration pill according to a first embodiment of the invention, the pill comprising two conjoined half-cylinders (of which only one is shown) each incorporating a set of half-discs spaced at intervals along the longitudinal axis;
[0045] FIG. 2 shows an alternative, multi-wire half-cylinder assembly;
[0046] FIG. 3 shows a schematic diagram of a crystal growing trough for use in a method of manufacturing a refrigeration pill of the type illustrated by FIGS. 1 and 2 ; the vertical direction defines a direction of crystal growth; a magnetic field may be applied with a component in the longitudinal (horizontal) direction;
[0047] FIGS. 4 a and 4 b show, respectively, a fully constructed solid-state refrigeration pill sealed within an outer cylinder, and a section through the end cap along the axis of the cylinder in showing a preferred sealing method;
[0048] FIG. 5 shows a microscopic region of a solid-state magneto-caloric material inside a refrigeration pill such as the type of FIG. 4 a;
[0049] FIGS. 6 a and 6 b show components of two alternative pill designs (a) and (b) based on a single cylinder illustrating, respectively, a magnetic refrigeration pill incorporating a metal skeleton comprising a wire mesh, and a magnetic refrigeration pill incorporating a metal skeleton comprising a set of longitudinal wires
[0050] FIG. 7 shows a region of an internal skeleton of a refrigeration pill of the general type shown in FIG. 1 , adapted for use with electro-caloric rather than magneto-caloric material and comprising an arrangement for alternate electrically insulated adjacent half discs;
[0051] FIGS. 8 a and 8 b illustrate a mechanical heat switch for a solid state adiabatic refrigerator according to an embodiment of the invention showing in (a), a cross section of the mechanical heat switch and in (b) a three dimensional view of parts of the switching mechanism;
[0052] FIG. 9 shows a schematic illustration of a superconducting heat switch which may be used in embodiments of the invention;
[0053] FIG. 10 shows a schematic illustration of the lower part of the sample holding portion of an adiabatic solid-state refrigeration system comprising, in the illustrated example, two solid-state refrigeration stages for serial cooling;
[0054] FIG. 11 shows a schematic illustration of an adiabatic solid-state refrigeration system comprising two solid-state refrigeration stages for parallel, continuous cooling; and
[0055] FIG. 12 shows a schematic illustration of an adiabatic solid-state refrigeration system with a facility for the refrigeration to be carried out displaced away from a sample platform, thermal contact being made through a boundary.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0056] Broadly speaking in embodiments the skeleton for each half of the pill involves the following components, all of which are gold plated high purity OFHC copper: i) a central supporting rod of rectangular cross-section running along the length of the half cylinder, ii) three perforated half discs braised to the supporting rod near the ends and centre of the rod, iii) of the order of 100×0.4 mm wires threaded through and braised to the equally spaced holes in the perforated half discs. Braised at both ends of one of the two skeletons (made with an extra-long supporting rod) is an end piece consisting of a flange with a threaded nipple.
[0057] In a more symmetrical alternative design the two skeletons are identical in that a single flange with a threaded nipple is braised at one end only of each skeleton in such a way as to make the nipple concentric to the axis of the outer sealing tube.
[0058] In an alternative to the above procedure the rectangular central supporting rod is replaced by two threaded rods passing through holes near to the two corners of the half disc and the third threaded rod equidistant to the first two and passing through a hole near the edge of the disc. The advantages of this scheme include: i) it provides for accurate alignment of the half discs; ii) it allows for the use of nuts to lock the plates in position and at the correct height, and hence avoid the need for braising; iii) it also allows for connection to the end flanges with threaded nipples via the use of copper nuts as above, and hence again avoids the need for braising; and iv) the procedure can readily be adapted with only minor changes (merely by increasing the number of half-discs employed, eliminating the wire assembly and replacing every other copper nut with an insulating ceramic nut and washer) for the preparation of multi-layer capacitor refrigeration pills using electrocaloric rather than the magnetocaloric effect that is the focus of attention here.
[0059] The two flanges, one at each end, are used for fitting an outer thin-wall sealing tube made of either fibre glass, stainless steel, brass or phosphor bronze. One of the two threaded ends is used to join the pill to the object to be cooled and the second is used in applications involving more than one cooling stage or to connect the pill to a thermally insulating centring ring. Each half skeleton in its entirety is gold plated after it has been assembled.
[0060] Some advantages of the half-disc arrangement are as follows: i) it provides for accurate alignment of the half discs; ii) it allows for the use of nuts to lock the plates in position at the correct height, and hence avoid the need for braising or welding; iii) it also allows for connection to the end double flanges with threaded nipples via the use of copper nuts as above, and hence again avoids the need for braising or welding; and iv) the procedure can readily be adapted with only minor changes (merely replacing every other copper nut with an insulating ceramic nut and washer) for the preparation of refrigeration pills using electrocaloric rather than the magnetocaloric effect.
[0061] The two skeletons are placed in a crystal growing trough and crystals are grown in both halves at the same time out of a solution containing the solute. Crystals grow as the concentration of the solute increases either by the evaporation of the solvent (typically water) or by a decrease in the temperature of the solution, or by a combination of the two methods. In the new procedure, crystal growth can typically be completed in a single day compared with weeks via current methods. Also crystals grown in this way are naturally aligned along the ideal crystallographic orientation for optimum magnetic refrigeration especially in the case of particular crystals (such as CMN) where this is necessary.
[0062] The surfaces of the two half-cylinders are leveled in preparation for assembly into a single cylinder in which the supporting rods are clamped together with screws near the ends. In contrast to current practice the outer cylinder used to protect the pill from damage and dehydration may be sealed via the use of indium O-rings, instead of epoxy or welded joints. Indium O-rings produce excellent seals, are inexpensive and easy to use, have low outgassing and vapour pressures, can be thermally cycled repeatedly without failure, eliminate the risk of damage to the refrigerant due to overheating (cf. curing of epoxies at elevated temperatures or use of a welding technique), and allow for the quick assembly as well as disassembly of the pill. This latter allows for non-destructive access to the core of the pill (crystallised salt and supporting skeleton) to allow for recycling of the parts of the assembly.
[0063] Referring now to FIG. 1 , this shows one of the two half cylinder skeletons used as a component to make a solid-state refrigeration pill. The parts shown in FIG. 1 comprise plates 101 and rods 102 . Both the plates and rods are made out of gold plated high conductivity oxygen-free copper or solid silver. Gold or silver are used to avoid corrosion of the thermal transport paths by the solid-state refrigeration material. The rods may be braised onto the plates or alternatively threaded to allow the plates to be secured with nuts before any gold plating, in either case mechanical stability and excellent thermal contact are achieved. The plates and rods form a thermal path in which to conduct heat efficiently throughout the half-cylinder.
[0064] FIG. 2 shows an alternative half-cylinder design comprising wires 102 , support rods 202 , end plates 203 and guide plate 204 . All parts 201 , 202 , 203 and 204 are made out of gold-plated oxygen-free high conductivity copper or solid silver. The rods 202 are braised to the parts 203 and 204 or attached with nuts. The wires 201 are braised or soldered to the parts 203 and 204 . The plates, wires and rods form a thermal path in which to efficiently conduct heat throughout the half-cylinder.
[0065] FIG. 3 shows a plastic crystal growing trough for use with assemblies such as those shown in FIG. 1 and FIG. 2 for the case when the solid-state refrigeration crystals are grown out of liquid solution. In such a case a half-cylinder assembly as shown in FIG. 1 and FIG. 2 is placed into the crystal growing trough and the solution poured into the trough with the solid-state refrigeration compound as a solute. In this scheme crystals are able to grow perpendicular to the axis of the cylinder, and crystal growth is quicker than in the case of growing crystals in a closed tube along the direction of the cylinder axis. In the case when the solid-state refrigeration material is not grown out of solution, powdered material may be pressed or glued onto metallic plates such as those in FIG. 1 .
[0066] Once the solid-state refrigeration material has been located onto skeletons such as those shown in FIGS. 1 and 2 , either via crystal growth from liquid solution or via pressed powders, the two half cylinders are brought together and attached with threaded end caps and encapsulated in an outer cylinder as shown in FIG. 4 a . The outer cylinder labelled 402 in FIG. 4 a is made out of thin walled phosphor bronze, stainless steel, brass or fibreglass. The threaded end cap labelled 401 is made out of gold plated high conductivity oxygen-free copper. One or both of the threaded end caps may be used to attach the refrigeration pill to the object or objects to be cooled, or used to attach the pill to other parts as may be necessary. FIG. 4 b shows a particular sealing mechanism employed to ensure the chemical content of the refrigeration pill is hermetically sealed inside the pill and maintains integrity during repeated thermal cycling between 300K and cryogenic temperatures. The rods 406 (the same as those as labelled 102 , 202 in FIGS. 1 and 2 ) pass through clearance holes in the end cap 401 and sealing plate 403 . Nuts 405 are screwed onto each of the threaded rods and used to tighten the sealing plate against the end cap squashing an indium wire 404 which under compression flows into any gaps and against the outer cylinder 402 making a vacuum tight seal. The region labelled 407 may then be filled with epoxy to provide an additional seal and further mechanical stability. The epoxy is selected to have a thermal expansion matched to the metals used to make the end cap. The solid-state refrigeration material is hermetically sealed inside the pill to avoid possible degradation on exposure to the outside environment. The sealing procedure is then repeated at the other end of the pill.
[0067] FIG. 5 shows a microscopic region of a solid-state magneto-caloric material inside a refrigeration pill such as that shown in FIG. 4 a . Sliver particles 501 are mixed with the solid state material 503 before and/or during the crystal growth process in the case of crystals grown from solution. In the case of a powdered solid-state refrigeration material, the silver particles are mixed with the powder before pressing onto plates such as those in FIG. 1 , part 101 . In either case the silver particles form dendrite like paths and assist thermal transport inside the completed pill resulting in more efficient cooling of the object to be refrigerated.
[0068] FIG. 6 shows components of two alternative pill designs (a) and (b) based on a single cylinder. In FIG. 6 a , a copper mesh 601 is rolled into a spiral and welded at each end to threaded end pieces 602 . Preferably the entire assembly is then gold plated. Magneto-caloric refrigeration material is grown from solution directly onto the wire mesh. End caps 603 are then fitted along with an outer cylinder to hermitically seal in the contents of the pill resulting in a finished pill like that shown in FIG. 4 a . In FIG. 6 b a similar design is employed but using gold-plated high conductivity oxygen free copper wires or solid silver wires 604 , which are again welded to threaded end pieces 605 . Magneto-caloric material is then grown onto the wires directly and hermetically sealed in an outer cylinder resulting in a pill like that shown in FIG. 4 a.
[0069] FIG. 7 shows a region of an internal skeleton of a refrigeration pill similar to that shown in FIG. 1 but adapted for use with electro-caloric rather than magneto-caloric material. The threaded rods 701 , 702 , and 703 and plates 704 are preferably made out of gold plated high conductivity oxygen free copper or solid silver. Support rod 703 is electrically insulated from every plate with plastic spacers and attached with nuts to secure each plate in place. A potential difference may be varied between rods 701 and 702 using an external voltage power supply connected to the rods with electrical wires which are attached to the rods at the end of the refrigeration pill. Rods 701 and 702 are electrically isolated from every other plate in a staggered arrangement as shown in the figure using pastic spacers 705 and secured with nuts. On every other plate, rods 701 and 702 are electrically and thermally connected to the plate using nuts as shown in the Figure. This allows for the voltage on every other plate to be identical and for a potential difference to be maintained between each plate. With this multi-layer capacitor geomentry large electric fields can be maintained between the plates and used to facilitate electro-caloric refrigeration once the electro-caloric material has been grown onto the plates out of solution or pressed or glued onto the plates in powder form using the same methods as the previously described magneto-caloric refrigeration pills.
[0070] FIG. 8 shows a mechanical heat switch. In FIG. 8 a a cross section of the mechanical heat switch is shown and in FIG. 8 b a three dimensional view of the key parts of the switching mechanism is shown. Two plates 801 and 802 may be thermally connected or disconnected using the mechanism comprising parts 803 , 804 , 805 and 806 . Low thermal conductivity rods 807 are used to support the plates whether the heat switch is open or closed. A gold plated high-conductivity oxygen-free copper cup 803 is thermally anchored to the lower plate 802 . Gold plated metal spring fingers 804 may be extended or retracted in the radial (horizontal) direction using a conical stainless steel rod 805 connected to a screw threaded mechanism 806 which is used to raise and lower the conical rod in the vertical direction either manually or with a motor. The spring fingers 804 are thermally anchored to the top plate 801 at all times. By raising the conical rod, the spring fingers are extended radially outwards and may be pressed against the cup 803 , thus thermally connecting plates 801 and 802 . By lowering the conical rod the spring fingers are retracted radially inwards and become detached from the cup 803 , thus thermally disconnecting plates 801 and 802 .
[0071] FIG. 9 shows a superconducting heat switch. Two plates 901 and 902 supported by low thermal conductivity rods 903 may be thermally connected or disconnected using a superconducting material 904 such as high purity lead or tin at any temperature below the superconducting transition temperature of the material. The strip 904 is soldered at each end to oxygen-free high conductivity copper platforms 905 which are thermally anchored to the plates 901 and 902 . When in the superconducting state, the strip 904 has a very low thermal conductivity and thus the plates 901 and 902 are essentially thermally disconnected from each other. By applying a sufficiently large magnetic field, the strip 904 can be transformed into its normal (non-superconducting) metallic state, having a high thermal conductivity, and thus thermally connecting the plates 901 and 902 .
[0072] A refrigeration pill according to an embodiment of the invention may be used in an adiabatic refrigeration system.
[0073] More particularly, FIG. 10 shows an example adiabatic solid-state refrigeration system with two stages for serial cooling, showing a schematic of the lower part of an inner vacuum chamber of a cryogenic insert used to refrigerate samples in vacuum down to milli-Kelvin temperatures with solid-state refrigeration pills. Solid lines denote thermal conductors and dashed lines denote thermal insulators. By employing two or more solid-state refrigeration pills containing the same or different solid-state refrigeration material, and arranged in a series configuration, a lower overall base temperature may be achieved than in the case of using a single refrigeration pill. A refrigeration procedure may proceed as follows using the example of two refrigeration pills in series. Initially both heat switches as shown in the figure are closed and both pills and sample plate are cooled to the temperature of the thermal bath, typically a 4K or 1K plate held at a constant temperature by an external refrigeration device not under consideration here. Both pills are magnetised using solenoids and the temperature of each part of the system is allowed to equilibrate back to the 1K/4K plate temperature. Heat switch 1 is then opened and refrigeration pill 1 is demagnetised adiabatically by sweeping down the magnetic field applied to pill 1 sufficiently slowly. Refrigeration pills 1 and 2 and the sample plate then reach the first cooling stage temperature. At this time, heat switch 2 is opened and refrigeration pill 2 is demagnetised adiabatically. As a result the sample plate and any attached sample are cooled from the first stage temperature to the second stage temperature. With this method 1 mK temperatures have been achieved. In the case when the active solid-state refrigeration material is an electro-caloric as opposed to magneto-caloric material, electric fields are applied instead of magnetic fields using the multi-layer capacitor geometry of the internal structure of the pill.
[0074] Continuing to refer to FIG. 10 , the skilled person will appreciate that in a simple refrigeration system only a single solid-state pill need be employed. If used with a system as described later with reference to FIG. 12 the sample holder and pill combination may replace the solid-state refrigeration devices shown in that Figure (described later). In such an arrangement the sample holder of FIG. 10 may be enclosed in an evacuated vacuum can and this may, in turn, fit within the vacuum tube of FIG. 12 . Preferably the components are arranged so that the 1 K-4 K plates of the holder and those shown in the FIG. 12 system are aligned at substantially the same level (or, if not, thermally linked, for example by a vertical metal heat conductor or conductive coating(s) on the vacuum tube wall(s))—with such arrangements there can be sufficient lateral thermal conduction through the vacuum can walls to enable efficient cooling.
[0075] FIG. 11 shows a schematic of the lower part of an inner vacuum chamber of a cryogenic insert used to refrigerate samples in vacuum down to milli-Kelvin temperatures with solid-state refrigeration pills. Solid lines denote thermal conductors and dashed lines denote thermal insulators. By employing more than one solid-state refrigeration pill arranged in a parallel configuration as indicated, a sample may be continuously cooled. A continuous refrigeration cycle may proceed as follows using the example of two refrigeration pills in parallel as shown in the figure. Initially all the heat switches are closed and both pills and sample plate are cooled to the temperature of the thermal bath, typically via a 4 K or 1 K plate held at a constant temperature by an external refrigeration device not under consideration here. Both pills are magnetised using solenoids and the temperature of each part of the system is allowed to equilibrate back to the 1K/4K plate temperature. Heat switch 1 a and 2 b are then opened and with heat switch 1 b closed, refrigeration pill 1 is demagnetised adiabatically and thus the sample plate and any attached sample are cooled due to the magneto-caloric effect. Heat switch 1 b is then opened, heat switch 1 a closed, heat switch 2 a opened and heat switch 2 b closed. Refrigeration pill 2 is then demagnetised while simultaneously refrigeration pill 1 is magnetised over the same time period. Once complete, the positions of all the heat switches are inverted followed by demagnetising pill 1 and magnetising pill 2 . This process may be continually cycled to continuously cool the sample plate and any sample maintaining a temperature below that of the 1 K/4 K plate typically in the milli-Kelvin range. In the case when the active solid-state refrigeration material is an electro-caloric as opposed to magneto-caloric material, electric fields are applied instead of magnetic fields using the multi-layer capacitor geometry of the internal structure of the pill.
Cryogenic Platform
[0076] In embodiments a cryogenic platform is used to produce initial cooling of the sample insert and solid-state refrigeration device(s). Typically the initial cooling is to a temperature in the range 1 K to 4 K, for example using either liquid-cryogens such as liquid helium-4 or liquid-cryogen free systems such as a pulse tube cooler or Gifford-McMahon cooler. A sample insert, for example as shown in FIGS. 10 and 11 , with one or more refrigeration pills attached and sealed inside a vacuum tube, may be lowered into the cryogenic platform for initial cooling. Subsequent cooling to lower temperatures may then proceed by operating the solid-state refrigeration devices and heat switches. In an alternative arrangement, the solid-state refrigeration stage may be incorporated into the cryogenic platform itself, as shown in FIG. 12 , the sample platform making thermal contact with a solid-state refrigerator located on the cryogenic platform.
[0077] FIG. 12 shows a schematic diagram showing a cross-section of a simplified cryogenic platform. In embodiments such a platform allows the temperature of a sample or device under test to be continuously varied between room temperature and the low milli-Kelvin range. In particular embodiments, other parameters such as the sample magnetic field, electric field or pressure, may be varied as well as the temperature. The cryogenic platform comprises a metal dewar, the interior of which is pumped out and maintained at a high vacuum. The interior of the dewar contains metal mounting platforms, refrigeration plates, thermal radiation shields, a vacuum tube for sample access, one or more solid-state refrigeration devices (SSR), one or more heat switches and a sample platform. When running, a cryogenic (1 K-4 K) plate is cooled by a liquid-cryogen free system such as a pulse tube cooler or Gifford-McMahon cooler built into the cryogenic platform (not shown). The solid-state refrigeration device (SSR) may be made from a magnetocaloric material, in which case it may comprise a refrigeration pill, for example as described in any one of FIGS. 1 to 6 , plus an encapsulating solenoid to apply a magnetic field to the refrigeration pill. Alternatively it may be made from a thermoelectric or an electrocaloric material; in the latter case it may comprise a refrigeration pill made from a multi-layer capacitor such as that described with reference to FIG. 7 . The heat switches may be mechanical, for example as shown in FIG. 8 , superconducting as shown in FIG. 9 , piezoelectric, or helium gas based. Thermal radiation shields are preferably installed to help thermally isolate the sample space and SSRs.
[0078] In operation, with the heat switches closed, one or more solid-state refrigeration devices as well as the base temperature plate and the sample platform are cooled to the temperature of the (1 K-4 K) plate. A sample mounted on a sample holder such as a puck (not shown in the Figure) may be lowered into the vacuum tube of the cryogenic platform and attached to the sample platform using a removable insertion rod. An insert fitted with radiation baffles may then optionally be placed inside the vacuum tube and sealed on the top flange to help prevent the sample from being heated by thermal radiation. One or more SSR devices may then be operated along with the heat switches to cool the sample below the cryogenic (1 K-4 K) plate temperature to a temperature typically in the low milli-Kelvin range.
[0079] In a particularly simple mode of operation, the cryogenic platform is fitted with a single SSR and may then be used with a single heat switch installed between the SSR and the cryogenic (1 K-4 K) plate. In this case, using the example of a magnetocaloric SSR, the magnetocaloric material is magnetised, the SSR and the sample platform left to equilibrate at the cryogenic (1 K-4 K) plate temperature. The heat switch is then opened and the SSR demagnetised adiabatically resulting in the sample plate cooling to a temperature in the low milli-Kelvin range.
[0080] In more advanced embodiments, one or more SSRs may be used in series or parallel modes to allow for a lower base temperatures or continuous cooling respectively. FIG. 12 shows an example based on two SSRs which may be operated in either series or parallel mode, depending on user requirements.
[0081] No doubt many other effective alternatives will occur to the skilled person. It will be understood that the invention is not limited to the described embodiments and encompasses modifications apparent to those skilled in the art lying within the spirit and scope of the claims appended hereto. | We describe a refrigeration pill for an adiabatic solid-state magnetocaloric or electrocaloric refrigerator, the pill having longitudinal and transverse axes, said pill comprising: a housing divided along said longitudinal axis into first and second housing parts; wherein each of said housing parts comprises a thermally conducting metal skeleton within the respective said housing part; and wherein regions within said housing between elements of said skeleton comprise magnetocaloric or electrocaloric material. We also describe methods of manufacturing the pill, and various solid state refrigeration systems, and related apparatus. | 8 |
TECHNICAL FIELD OF THE INVENTION
The present invention relates generally to the folding of flexible, multi-layer, sheet-like articles, such as bags. More specifically, the present invention relates to folding vehicular air bags.
BACKGROUND OF THE INVENTION
Vehicular air bags are among the latest safety enhancements for automobiles and other vehicles. Their use in vehicles is increasing dramatically. Generally, such air bags are located within a steering wheel or column, dashboard, control panel, or other out-of-the-way location which is near a vehicle's occupant. Sensors located in the vehicle detect when a crash is occurring and activate the air bag(s). When activated, the air bags rapidly inflate between the vehicle's occupant and a potentially injurious or deadly surface, such as a steering wheel. As the crash progresses, the force of the crash may hurl the occupant toward the injurious or deadly surface, but the occupant first encounters the air bag, which prevents or otherwise lessens injury to the occupant.
In order for the air bag to be effective, it must be stored in an out-of-the-way location until needed. Moreover, it must be stored in such a manner that it can be rapidly activated to do its job. Due to the continual down-sizing of vehicles, the out-of-the-way locations where air bags are typically located are usually rather small. Thus, an air bag must be folded into a small package so that it fits into a small location. But, the technique used to fold the air bag affects its deployment when activated. To minimize the possibility of harm to a vehicle occupant, the air bag preferably deploys evenly in a spreading out (side-to-side) manner rather than shooting first toward one side then the other or shooting straight out then filling in from side-to-side.
The conventional process for folding vehicular air bags relies almost exclusively on manual labor. This conventional process is plagued with problems. For example, approximately 12 minutes are required to fold an air bag using manual labor. With the large number of air bags now being used in vehicles, a tremendous amount of labor and expense is required to fold air bags. Moreover, the folding of air bags requires a large number of highly repetitive manual motions. Such repetitive motions are potentially hazardous to the health of the manual laborers. In addition, such repetitive motions lead to boredom, which in turn leads to a poor performance of the job.
Another problem relates to the consistency with which bags are folded using the conventional process. While some bags get folded acceptably, others tend to be folded using a less-than-optimal folding pattern or in a manner which results in an overly large package. This lack of consistency results in a considerable amount of rework, which is expensive, and inconsistent bag deployment patterns, which may pose unnecessary dangers to vehicle occupants.
SUMMARY OF THE INVENTION
Accordingly, it is an advantage of the present invention that an automated system for folding air bags is provided.
Another advantage of the present invention is that a system for folding bags quickly is provided.
Yet another advantage of the present invention is that a system for folding air bags in a consistent fold pattern is provided.
Still another advantage of the present invention is that a system for folding air bags to consistently achieve a desirable deployment pattern is provided.
Still another advantage of the present invention is that a system for consistently folding air bags to achieve a small folded-bag profile is provided.
The above and other advantages of the present invention are carried out in one form by a method of automatically folding an air bag. The air bag characteristically has top and bottom sections, and the folding method achieves a folded-bag profile that is suitable for vehicular installation along with effective bag deployment in the event of a vehicle crash. The method calls for clamping the top and bottom sections of the bag together. This clamping action occurs near an edge portion of the bag and substantially restricts inflation of the edge portion but leaves a central portion of the bag unclamped. After clamping, the central portion is inflated so that the top section of the air bag separates from the bottom section. When the top and bottom sections have been separated, the clamped edge portion is inserted into the central portion between the top and bottom sections.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present invention may be derived by referring to the detailed description and claims when considered in connection with the FIGURES, wherein like reference numbers refer to similar items throughout the FIGURES, and:
FIG. 1 shows a perspective view of a preferred embodiment of the present invention in connection with an air bag and prior to a first stage in the preferred process for folding the air bag;
FIG. 2 shows a block diagram of the preferred embodiment of the present invention;
FIG. 3 shows a cross sectional view of the preferred embodiment of the present invention after a second stage in the preferred process for folding the air bag;
FIG. 4 shows a cross sectional view of the preferred embodiment of the present invention after a third stage in the preferred process for folding the air bag;
FIG. 5 shows a cross sectional view of the preferred embodiment of the present invention after a fourth stage in the preferred process for folding the air bag;
FIG. 6 shows a cross sectional view of the preferred embodiment of the present invention after a fifth stage in the preferred process for folding the air bag;
FIG. 7 shows a cross sectional view of the preferred embodiment of the present invention after a sixth stage in the preferred process for folding the air bag;
FIG. 8 shows a cross sectional view of the preferred embodiment of the present invention after a seventh stage in the preferred process for folding the air bag;
FIG. 9 shows a cross sectional view of the preferred embodiment of the present invention after an eighth stage in the preferred process for folding the air bag;
FIG. 10 shows a cross sectional view of the preferred embodiment of the present invention after a ninth stage in the preferred process for folding the air bag;
FIG. 11 shows a cross sectional view of the preferred embodiment of the present invention after a tenth stage in the preferred process for folding the air bag;
FIG. 12 shows a cross sectional view of the preferred embodiment of the present invention after an eleventh stage in the preferred process for folding the air bag;
FIG. 13 shows a cross sectional view of the preferred embodiment of the present invention after a twelfth stage in the preferred process for folding the air bag;
FIG. 14 shows a cross sectional view of the preferred embodiment of the present invention after a thirteenth stage in the preferred process for folding the air bag;
FIG. 15 shows a cross sectional view of the preferred embodiment of the present invention after a fourteenth stage in the preferred process for folding the air bag;
FIG. 16 shows a cross-sectional view of the air bag folded in accordance with the preferred process; and
FIGS. 17A-17F together show exemplary vertical folds which may be utilized to place the air bag in a final stage.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following description certain items are either identical to or mirror images of other items. This description distinguishes such items from their counterparts by the use of lower case alphabetic characters ("a", "b", and so on) which are appended to a common reference number. When an alphabetic character is omitted, the description refers to any one of such items or their counterparts individually or to all of them collectively.
FIG. 1 shows a perspective view of a preferred embodiment of a bag folding machine 10 configured in accordance with the present invention. FIG. 1 further shows a deflated air bag assembly 12 positioned on machine 10. FIG. 1 illustrates the state of machine 10 and bag assembly 12 prior to a first stage (discussed below) in a preferred process for folding bag assembly 12.
Machine 10 includes a top blade 14, which is rotatable from an upright position, shown in FIG. 1, to a lowered position, in which blade 14 closely overlies bag assembly 12. The central region of blade 14 carries pins 16a, 16b, 16c, and 16d. Pins 16 couple to and extend perpendicularly away from blade 14. Furthermore, pins 16 are movable from a raised position relative to blade 14, shown in FIG. 1, to a lowered position, discussed below. In viewing FIG. 1, pins 16a and 16b reside on the left side of blade 14 while pins 16c and 16d reside on the right. Elastic band 18a is looped around pins 16a and 16c underneath blade 14, and elastic band 18b is looped around pins 16b and 16d underneath blade 14.
Machine 10 additionally includes an edge folding assembly (EFA) 20, which is shown positioned behind bag assembly 12 in FIG. 1. EFA 20 is moveable from its rearward position shown in FIG. 1 to a forward position where it engages bag assembly 12.
EFA 20 carries five arms which move together between the rearward and forward positions. These five arms include a center arm 22, left and right fork arms 24a and 24b, respectively, and left and right outer blades 26a and 26b, respectively. Center arm 22 remains stationary relative to EFA 20. In other words, arm 22 moves only inward and outward with the entire EFA 20 and does not move any substantial distance either upward, downward, left, or right.
Fork arms 24 each reside between respective outer blades 26 and center arm 22. Each fork 24 resembles a U-channel having an upper plate or tine 28a and an opposing lower plate or tine 28b. For each fork 24, tines 28 are spaced apart from one another by a gap 30, and the U-channel opening, hereinafter referred to as an entrance edge 32, faces away from the center of machine 10. Each fork 24 may move upward from its downward position, shown in FIG. 1, with respect to EFA 20. In other words, forks 24 move forward and backward with the entire EFA 20 as well as upward and downward.
Outer blades 26 are positioned vertically at a level slightly above center arm 22. Each blade 26 is configured to move from an outward position, shown in FIG. 1, to an inward position with respect to EFA 20. As discussed in more detail below, when forks 24 are in their upward positions, gaps 30 are vertically aligned with outer blades 26, and when outer blades 26 move to their inward position, they mesh with gaps 30.
Machine 10 additionally includes pleat clamps 34a and 34b located to the left and right, respectively, of outer blades 26 from EFA 20 and at roughly the same vertical level as outer blades 26. FIG. 1 shows pleat clamps 34 in their extreme outer positions. However, pleat clamps 34 are each movable to an intermediate position and an extreme inner position, as will be discussed below.
As a whole, pleat clamps 34 remain substantially stationary in the vertical dimension. However, each of pleat clamps 34 carries upper and lower plates or fingers 36a and 36b, respectively. The horizontal length (generally from left-to-right in FIG. 1) of fingers 36 is slightly greater than the sum of the horizontal lengths of one outer blade 26 and one fork arm 24. Fingers 36 move vertically with respective to one another. FIG. 1 shows an opening 38 between fingers 36 at its widest. As is discussed below, fingers 36 move vertically toward one another so that opening 38 disappears and a clamping force is exerted between fingers 36. Fingers 36 additionally exhibit a position in which opening 38 is very small and at which no clamping force is exerted between fingers 36.
Each of fingers 36 includes two notches 39 which accommodate pins 16, as discussed below. Notches 39 extend left-to-right from inward edges (facing the center of machine 10) of fingers 36 outward into the interior of their corresponding fingers 36.
FIG. 1 shows air bag assembly 12 in a deflated and unfolded state, which causes bag assembly 12 to roughly resemble a thin pancake. In viewing bag assembly 12 vertically from bottom to top, assembly 12 includes a base plate 40 secured to a sealed, flexible bag 42. Bag 42 includes a bottom section 44, which attaches to base plate 40 and a top section 46, which overlies bottom section 44 in the deflated state illustrated in FIG. 1. In viewing bag 42 horizontally, left edge portion 48a and right edge portion 48b are separated from one another by central portion 50. Base plate 40 attaches to bag 42 only in the central region of central portion 50 and not in end portions 48.
Base plate 40 of air bag assembly 12 couples to a worksurface 52 of machine 10. Although not visible in FIG. 1, base plate 40 includes a pneumatic passage which is continued through worksurface 52, through a valve arrangement 54, to pressure and vacuum reservoirs 56 and 58, respectively. Accordingly, valve 54 may be operated to apply pneumatic pressure to air bag assembly 12, seal air bag assembly 12, or apply pneumatic vacuum to air bag assembly 12.
FIG. 2 shows a block diagram of the preferred embodiment of machine 10. As discussed above in connection with FIG. 1, numerous blades, arms, and fingers of machine 10 are moveable. FIG. 2 shows that machine 10 employs a controller 60 to coordinate such movements. Those skilled in the art will appreciate that any suitable programmable controller, personal computer, or similar item may suffice for controller 60.
Controller 60 couples, through an appropriate control bus 62, to numerous actuators which control the above-discussed movements. In particular, an actuator 64 mechanically couples to and controls the upward and downward movement of top blade 14; an actuator 66 mechanically couples to and controls the upward and downward movements of pins 16; an actuator 68 mechanically couples to and controls the forward and backward movements of EFA 20; an actuator 70 mechanically couples to and controls the upward and downward movements of EFA forks 24; an actuator 72 mechanically couples to and controls the left and right movements of EFA outer blades 26; an actuator 74 mechanically couples to and controls the left and right movements of pleat clamps 34; an actuator 76 mechanically couples to and controls the upward and downward movement of pleat clamp fingers 36; and, an actuator 78 couples to valve 54 to close valve 54, or to control the application of pressure or vacuum.
Those skilled in the art will appreciate that the precise programming instructions and the nature of the control imparted through controller 60 and actuators 64-78 has little bearing on the present invention, other than in accomplishing the below-discussed process. For example, while the preferred embodiment of the present invention primarily uses pneumatic actuators, those skilled in the art may adapt hydraulic or solenoid actuators to impart the above-discussed movements. Moreover, those skilled in the art will fully appreciate that limit or position switches or sensors may be employed in a conventional fashion within machine 10 to indicate to controller 60 when desired positions (discussed below) are achieved through such movements. Moreover, multiple actuators may be employed to move arms, such as EFA outer blades 26, individually rather than as a unit. And, other well known mechanical devices, such as slides, levers, gears, belts, and the like, may be employed to transfer and guide the arm motions discussed herein.
FIG. 1 and FIGS. 3-15 together present various states or stages through which machine 10 and air bag assembly 12 progress in making horizontal folds in air bag 42. As discussed above, FIG. 1 illustrates machine 10 and bag assembly 12 prior to a first stage in the horizontal folding process. Prior to the first stage, center portion 50 of bag 42 is supported, but nothing supports edge portions 48 of bag 42. Thus, edge portions 48 droop downward. The first stage results from moving top blade 14 from its upper position to its lower position. In its lower position, top blade 14 overlies and is spaced a distance apart from the top of central portion 50 of bag 42. Top blade 14 carries pins 16, which will be used later in the folding process.
FIG. 3 illustrates machine 10 and bag assembly 12 after a second stage, which occurs immediately after the first stage. In the second stage, EFA 20 moves forward where it engages bag 42. In particular, center arm 22 of EFA 20 slides over central portion 50 of bag 42 and underneath top blade 14, EFA forks 24 move underneath corresponding edge portions 48 of bag 42, and outer blades 26 move over bag 42. As shown in FIG. 3, due to the droop in bag 42 forks 24a and 24b actually reside to the inside (right and left) of end portions 48a and 48b, respectively. For the same reason, outer blades 26a and 26b currently reside above and to the outside (left and right) of end portions 48a and 48b, respectively.
FIG. 4 illustrates machine 10 and bag assembly 12 after a third stage, which occurs immediately after the second stage. In the third stage, EFA forks 24a and 24b have moved to their upper positions. In these upper positions, the central regions of gaps 30 in forks 24 reside at approximately the same vertical height as outer blades 26. All outer blades 26 and forks 24 are positioned vertically above center arm 22. This movement of forks 24 removes some of the droop in bag 42. However, the outermost regions of end portions 48a and 48b now extend vertically downward through and past gaps 80, which define the horizontal spaces between outer blades 26 and corresponding forks 24.
FIG. 5 illustrates machine 10 and bag assembly 12 after a fourth stage, which occurs immediately after the third stage. In the fourth stage, vacuum is applied to bag 42. Outer blades 26a and 26b move into, or mesh with, gaps 30 in forks 24a and 24b, respectively. Bends, folds, or pleats 82a, 82b, 84a, and 84b are formed in end portions 48 of bag 42 as a result of this relative movement between outer blades 26 and forks 24.
In particular, as outer blades 26 move into gaps 30, the outermost regions of end portions 48 are tucked between tines 28 of forks 24. The much of the excess material of bag 42 that drooped vertically downward past gaps 80 after the third stage is now drawn into gaps 30. Only the very ends of bag 42 extend out and droop down from the entrance edges of forks 24. Moving from the outermost edges of bag 42 inward, pleats 82a and 82b reside at leading edges 86a and 86b of outer blades 26a and 26b, respectively, as bag 42 bends back on itself and is juxtaposed on opposing sides of blades 26a and 26b. Pleats 84a and 84b reside at entrance edges 32 of tines 28a of forks 24a and 24b, respectively, as bag 42 bends back on itself again and is juxtaposed on opposing sides of tines 28a of forks 24a and 24b.
FIG. 6 illustrates machine 10 and bag assembly 12 after a fifth stage, which occurs immediately after the fourth stage. In the fifth stage, pleat clamps 34a and 34b, each with their fingers 36 opened to their maximum amount of extension, move inward toward the central portion 50 of bag 42. In this stage, pleat clamps 34 each stop at their intermediate positions. This causes the outer ends of bag 42 to be folded under forks 24. At the current point in the process, openings 38 between fingers 36 are sufficiently wide to loosely accommodate corresponding forks 24 and two thicknesses of bag 42. Inner tips 88 of fingers 36 are now positioned around points vertically above and below leading edges 86 of outer blades 26.
FIG. 7 illustrates machine 10 and bag assembly 12 after a sixth stage, which occurs immediately after the fifth stage. In the sixth stage, outer blade 26b is retracted from gap 30 in fork 24b by moving horizontally outward. Outer blade 26a remains positioned within gap 30 of fork 24a to reduce bag distortion in subsequent stages. The natural stiffness of bag 42 along with the friction of bag 42 against interior walls of forks 24 causes bag 42 to remain within gap 30 of fork 24b rather than be drawn outward with outer blade 26b. As shown in FIG. 7, the length of fingers 36 accommodates both fork 24b, outer blade 26b in its retracted state, and gap 80.
FIG. 8 illustrates machine 10 and bag assembly 12 after a seventh stage, which occurs immediately after the sixth stage. In the seventh stage, EFA 20, which includes outer blades 26, forks 24, and center arm 22, is removed from engagement with bag 42 by moving backward. The vacuum previously applied to bag 42 along with the natural stiffness of bag 42 prevents distortion of pleats 82 and 84 previously formed in bag 42 or other significant disturbances of bag 42. At this point, the folds previously made in end portions 48 of bag 42 are supported by lower fingers 36b of pleat clamps 34.
FIG. 9 illustrates machine 10 and bag assembly 12 after an eighth stage, which occurs immediately after the seventh stage. In the eighth stage, pleat clamp fingers 36 have been urged together by being moved to their clamped position. In other words, a clamping force is exerted between fingers 36 thereby entrapping pleats 82 and 84 within fingers 36. These clamping forces are sufficiently great to prevent any substantial inflation of the portions of bag 42 residing within pleat clamps 34. This clamped portion of bag 42 currently resides slightly above central portion 50 of bag 42.
FIG. 10 illustrates machine 10 and bag assembly 12 after a ninth stage, which occurs immediately after the eighth stage. In the ninth stage, the previously applied vacuum is removed and then pneumatic pressure is introduced to bag assembly 12, thereby inflating bag 42. Of course, pleat clamps 34 prevent those portions of bag 42 which are entrapped therein to become inflated at this stage. Consequently, primarily the central portion of bag 42 becomes inflated. By inflating bag assembly 12, top section 46 of bag 42 becomes separated from bottom section 44 and moves upward. In fact, top section 46 now resides above the portions of bag 42 that are trapped within pleat clamps 34 while bottom section 44 resides below the portions of bag 42 that are trapped within pleat clamps 34. Blade 14 limits top section 46 of bag 42 from extending further upward. Consequently, the shape of bag 42 is bound in the vertical dimension by plate 40 on the bottom and blade 14 on the top.
FIG. 11 illustrates machine 10 and bag assembly 12 after a tenth stage, which occurs immediately after the ninth stage. In the tenth stage, pleat clamps 34 move further inward toward central portion 50 of bag 42. Top blade 14 and bottom plate 40 prevent the bag from distorting outward in the vertical dimension during this operation. Pleat clamps 34 each stop at their extreme inward positions, in which inner tips 88 of fingers 36 nearly touch each other but are still spaced a small distance apart. Of course, the portions of bag 42 which have been entrapped within fingers 36 by clamping move inward with pleat clamps 34. Consequently, the entire edge portions 48 of bag 42 have been poked into the central portion 50 of bag 42.
FIG. 12 illustrates machine 10 and bag assembly 12 after an eleventh stage, which occurs immediately after the tenth stage. In the eleventh stage, vacuum is applied to bag assembly 12 to deflate bag 42. In addition, pins 16 are moved downward through slots 39 in pleat clamp fingers 36. As pins 16 move downward, elastic bands 18 stretch over the top of central portion 50 of bag 42. This stretching of bands 18 exerts a corresponding downward force on top section 46 of bag 42. As bag 42 deflates, this downward force overcomes the natural stiffness of bag 42 causing bag 42 to collapse and top section 46 to move downward as vacuum is applied.
FIG. 13 illustrates machine 10 and bag assembly 12 after a twelfth stage, which occurs immediately after the eleventh stage. In the twelfth stage, fingers 36 of pleat clamps 34 are moved to their intermediate state, in which clamping forces are removed and fingers 36 are spaced only a small distance apart. In short, pleat clamps 34 are loosened, thereby abandoning the grip they previously had on the entrapped portions of bag 42.
FIG. 14 illustrates machine 10 and bag assembly 12 after a thirteenth stage, which occurs immediately after the twelfth stage. In the thirteenth stage, pleat clamps 34 are disengaged from bag 42 by moving horizontally outward. In this stage, clamps 34 are moved to their extreme outward positions. Fingers 36 may additionally be moved to the positions where they are spaced furthest apart in preparation for a subsequent folding process. Notches 39 (see FIG. 1) in fingers 36 permit this outward movement while pins 16 remain in their downward position. Since clamps 34 had previously been loosened, scant frictional forces oppose this retraction of pleat clamps 34. Thus, pins 16, the vacuum applied to bag 42, and the natural stiffness of bag 42 together serve to prevent any significant disturbance of the folds previously formed in bag 42.
FIG. 15 illustrates machine 10 and bag assembly 12 after a fourteenth stage, which occurs immediately after the thirteenth stage. In the fourteenth stage, top blade 14, pins 16, and elastic bands 18 are disengaged from bag assembly 12 primarily by raising top blade 14. Pins 16 may additionally be retracted to their raised position in preparation for a subsequent folding process.
As a result of the process described above, bag assembly 12 has undergone a horizontal folding process. The resulting folded-bag profile is shown in cross section in FIG. 16. As shown in FIG. 16, bag 42 of bag assembly 12 fits within the profile defined by base plate 40. This fold pattern is desirable because it produces an effective deployment pattern. In particular, the central joint region 90 together with top and bottom joints 92 and 94, respectively, cause bag assembly 12 to inflate evenly in a left-to-right direction while bag assembly 12 is expanding away from plate 40. In addition, the overall folding process is performed quickly.
FIGS. 17A-17F together illustrate vertical folds which may be performed either manually or automatically to completely fold bag 42 onto the profile defined by base plate 40. After vertical folds have been completed, folded bag assembly 12 is ready for installation in a vehicle.
In summary, the present invention provides an automated system for folding air bags. An air bag can be installed on machine 10 in around 4 seconds and then, under the direction and coordination of controller 60 (see FIG. 2), folded in about 20 seconds. An additional 15-17 seconds are required for an operator to make the vertical folds and unload machine 10. Consequently, machine 10 and the process by which bag assemblies 12 are folded result in a system which quickly folds bags and achieves significant time savings over the conventional manual folding process. Moreover, the automated nature of the system of the present invention leads to a consistent fold pattern. In other words, each bag is folded in substantially the same way as every other bag. This consistent fold pattern achieves a desirable deployment pattern along with a small folded-bag profile, which is entirely contained within the area of base plate 40.
The present invention has been described above with reference to preferred embodiments. However, those skilled in the art will recognize that changes and modifications may be made in these preferred embodiments without departing from the scope of the present invention. For example, the above description uses the terms left, right, forward, backward, top, bottom, up, down, raised, lowered, horizontal, vertical, and the like, to indicate relative direction with respect to the FIGURES. Those skilled in the art will understand that such relative terms are used to clarify the description and do not limit the scope of the present invention to any particular orientation. These and other changes, modifications, or altered orientations which are obvious to those skilled in the art are intended to be included within the scope of the present invention. | An automated system is disclosed for folding vehicle air bags so that a small folded-bag profile and a desirable bag deployment pattern results. A machine having numerous moveable arms is controlled by a controller. An edge folding assembly (EFA) of the machine has five arms, including a center arm, two outer blades, and two outwardly facing U-channel forks, which reside between respective outer blades and the center arm. The EFA moves forward so that all of its five arms engage an unfolded air bag. The forks then raise upward to a level at which the outer blades are aligned with a gap between tines in the forks. The outer blades mesh with this gap causing two pleats to be formed in the edge of the bag. Pleat clamps then move inwardly sideways to engage the two pleats and form a third pleat. Then, the EFA is removed from the bag. The pleat clamps clamp top and bottom sections of the bag together while tightly gripping the pleats. The bag is then inflated, except that the pleat clamps prevent inflation of the pleated section. Next, the pleat clamps move closer together to poke the pleats into the center of the otherwise inflated bag. The bag is then deflated, and the pleat clamps are withdrawn from the bag. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an economical method and apparatus for increasing the production of liquid or gaseous hydrocarbon material from subterranean deposits or wells and more particularly to increasing such production by removing flow restricting material from the production equipment and well.
2. Background of the Invention
The hydrocarbon production rate from hydrocarbon wells is known to decrease with time due to a build-up of deposits of contaminants in the ducts and pumps of the recovery or production equipment, in the well bore, and interstices or matrix of the well formation which restrict hydrocarbon flow. Eventually production diminishes to a level at which the difference between production costs and the value of the hydrocarbon product recovered is too low to warrant continued production.
The removal of flow restricting materials from the recovery equipment and well formation can extend both the economic life of the well and increase net well production volume.
It is the object of this invention to reduce flow-restriction caused by a build-up of contaminants such as asphalts, paraffins, clays, scales, silt and debris within the well formation, well bore, and hydrocarbon recovery equipment thereby increasing the flow of recoverable hydrocarbons to a recovery point outside the well.
SUMMARY OF THE INVENTION
The present invention provides a method for the dispersal and removal of flow restricting matter from a hydrocarbon producing well which includes introducing a first solvent for dissolving asphalt, wax, or a combination of asphalt and wax, into the well, introducing a second solvent for dissolving silt and scale into the well, removing the mixture of first solvent including solutes, the second solvent including solutes, and hydrocarbon liquid product from the well, electrolyzing the mixture, and reintroducing the electrolyzed mixture back into the well.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE shows a schematic diagram of the apparatus used to perform the disclosed method.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in the FIGURE, the apparatus 8 comprises an atmospheric tank 10 for containing treatment chemicals in liquid flow communication with a pressure vessel 12 by a first interconnecting conduit 14 interconnecting the outlet of the atmospheric tank 10 to the liquid inlet of the pressure vessel 12. A transfer pump 16 is located in the first interconnecting conduit 14 to pump liquid treatment chemicals from the atmospheric pressure tank 10 to the pressure vessel 12. A flow control valve 18 is located in the first conduit 14 between the outlet of atmospheric pressure tank 10 and the transfer pump 16 to selectively open and close liquid chemical flow communication from the atmospheric pressure tank 10 to the transfer pump 16, and a pressure vessel inlet valve 20 is located in the first conduit 14 between the transfer pump 16 and the inlet into pressure vessel 12 to selectively open and close liquid chemical flow communication from the transfer pump 16 to the pressure vessel 12. An air compressor 22 is in air flow communication with the pressure vessel 12 by a second interconnecting conduit 24 interconnecting the high pressure outlet of the compressor to an air inlet of the pressure vessel 12 to maintain a predetermined pressure within the pressure vessel 12. A pressure gage is connected to the pressure vessel 12 to monitor the pressure within the pressure vessel 12. An electrode chamber 26 is in liquid flow communication with the pressure vessel 12 by a third interconnecting conduit 28 interconnecting the liquid outlet of the pressure vessel 12 to the liquid inlet of the electrode chamber 26. A pressure release valve 30 is located in the third interconnecting conduit 28 immediately downstream of the liquid outlet of the pressure vessel 12 which opens at a predetermined pressure interior of the pressure vessel 12 to allow pressurized liquid chemicals to flow through the third interconnecting conduit 28 to the electrode chamber 26. A blocking valve 32 is also located in the third conduit 28 immediately upstream of the inlet into the electrode chamber 26 to selectively provide for the flow of liquid treatment chemicals into the electrode chamber 26 from the conduit 28. The liquid outlet of the electrode chamber 26 is in liquid flow communication with the well casing by an outlet conduit or fourth interconnecting conduit 34 for supplying the liquid treatment chemicals to the well. A valve 36 is located in the fourth interconnecting conduit 34 immediately downstream of the electrode chamber outlet and another valve 37 is located in the conduit 34 near the end of the conduit upstream of the well casing to selectively allow liquid chemicals to flow from the electrode chamber 26 to the well casing. A check valve 38 is also located in the fourth interconnecting conduit 34 to prevent liquid chemicals from flowing back into the electrode chamber 26 through the fourth conduit 34. The fourth conduit 34 can also include a chemical sample valve controlled faucet 40 downstream of the check valve 38 for drawing a sample of the liquid chemicals flowing from the electrode chamber 26 for testing purposes. A volume rate of flow counter 42 is connected to the fourth interconnecting conduit 34 for monitoring the volume rate of flow of the liquid chemicals flowing in the fourth conduit 34 from the electrode chamber 26 of the well. A bypass conduit 44 interconnects the first interconnecting conduit 14 to the fourth conduit 34 to bypass the pressure vessel 12 and electrode chamber 26. The bypass conduit 44 is connected to the first conduit 14 between the outlet of the transfer pump 16 and the pressure vessel inlet valve 12, and is connected to the fourth conduit 34 downstream of the volume rate of flow counter 42. Blocking valves 45 are located in the bypass conduit 44 to control the flow of liquid therethrough. A return or fifth conduit 46 interconnects the well casing to the third interconnecting conduit 28 for returning or recycling liquid treatment chemicals and hydrocarbon liquid to the electrode chamber 26 from the well. The return conduit 46 interconnects the well casing to the third conduit 28 at a location in the third conduit 28 downstream of the pressure release valve 30 and upstream of the blocking valve 32 in the third conduit at inlet into the electrode chamber 26. An appropriate blocking valve 48 is located in the return conduit 46 to selectively provide for the flow of returning liquid treatment chemicals and hydrocarbon liquid from the well through the return conduit 46 to the electrode chamber 26 through the return conduit 46. A valve 50 is also located in the return conduit 46 immediately downstream of the intersection of the return conduit 46 and the third conduit 28 to selectively prevent the flow of liquid treatment chemical from the pressure vessel 12 into the return conduit 46. The return conduit 46 can also include a chemical sample valve controlled faucet 54 upstream of the valve 50 for draining a sample of the liquid chemical returning from the well for purposes of testing it. In addition, a check valve 52 is located in the third conduit 28 upstream of the intersection of the return conduit 46 and the third conduit 28 to prevent the returning liquid treatment chemicals from flowing into the third conduit 28 into the pressure vessel 12. A pump 56 in liquid flow communication with both the outlet conduit 34 and return conduit 46 is located within the well casing to circulate the liquid chemical therein and return it through the return conduit 46.
Carbon rod electrodes 58 are located within the electrode chamber 26 and are energized by, for example, an AC generator 60 located outside the electrode chamber 20. An appropriate voltage meter 62 and current meter 64 are also associated with the AC generator 60 to monitor the output of the AC generator.
The chemical treating liquid is comprised of two constituents. These two constituents will be hereinafter referred to as a first solvent for dissolving asphalt, paraffin, or a combination of asphalt and paraffin; and a second solvent for dissolving inorganic deposits such as scale, silt and clays. Optionally, a third constituent, hereinafter referred to as a starter solution, can be included to generate heat for releasing gases from the treating liquid and the hydrocarbon product from the well.
The specific composition of the first solvent will vary somewhat depending upon whether the flow restricting material to be removed thereby is asphaltic based or paraffin based, or a combination. Regardless, the first solvent comprises a detergent for breaking up the asphalt or paraffin deposits permitting aqueous suspension of these deposits, and hydrocarbon solvents. One preferred first solvent wherein the flow restricting material is primarily asphalt comprises a detergent, for example a detergent of the type sold by Pilot Chemical Company under the brand designation TS-40, and three hydrocarbon solvents having different solubilities. Examples of such solvents are turpene and kerosene which are a moderate weight solvent, Methanol which is a light weight solvent, and benzene which is a heavy weight solvent. One preferred first solution wherein the flow restricting material is primarily paraffin comprises a detergent, for example a detergent of the type sold by Pilot Chemical Company under the brand designation T-60, and three hydrocarbon solvents having different solubilities. Examples of such solvents are turpene and kerosene which are a moderate weight solvent, toluene, benzene, acetone, hexane and trichloroethene which are heavy weight solvents, and isopropanol, methanol, and xylol which are light weight solvents.
It should be noted that the first solvent is comprised mostly of light hydrocarbon materials.
Optionallly, it is contemplated that a component be also added to the first solvent as a conductivity enhancer for removing the static electric charge often existing around a well which is created by the original drilling operation. Such an electrical enhancer is Status 450.
If the flow restricting material is a combination of asphaltic and paraffin first solvents, then a combination of the different components of the above asphaltic and paraffin formulas can be used as the first solvent.
The amount of each of the components of the first solvent will vary depending upon, for example, the depth of the formation of flow restricting material to be removed.
It has been determined that for each 1,200 feet of depth of an asphaltic based flow restricting material formation, the following amounts of each chemical component works well:
1 quart--detergent (TS-40),
6 gallons--Turpene
6 gallons--Kerosene,
6 gallons--Methanol,
6 gallons--Benzene.
It has been determined that for each 1,200 feet of depth of a paraffin based flow restricting material formation, the following amounts of each chemical component works well:
87/8 gallons--Turpene
35/8 gallons--Kerosene,
10 gallons--Hexane,
10 gallons--Trichloroethene,
2 ounces--detergent (T-60),
2 gallons--Toluene,
3 gallons--Benzene,
2 gallons--Isopropyl Methanol,
1 gallon--Acetone.
The specific composition of the second solvent comprises a solution of water, acid, and solvent. The second solvent is particularly useful when the flow restricting material comprises a substantial portion of paraffin in addition to silt and scale. An example of a second solvent is a solution of water, preferably sulfamic acid, and solvents such as xylol, hexane, benzene, isopropanol, methanol, and butanol.
It has been determined that for each 1,200 feet of depth of either of the asphalt formation or paraffin flow restricting material formation, the second solvent having the following amounts of each chemical component works well:
40 gallons--Sterile Water,
3 pounds--Sulfamic acid,
2 gallons--Hexane,
2 quarts--Xylol,
3 gallons--Benzene,
1 gallon--Butanol,
1 gallon--Isopropanol,
1 gallon--Methanol.
The starter solution comprises an aqueous solution of an acid, a base, and a wetting agent. Preferably, the acid is one which will not attack metals. Most preferably, the starter solution comprises sulfamic acid, soda ash, and a wetting agent of the type sold by Dupont Petroleum Chemicals Division of Dupont Corp. in Wellington, Delaware under the brand designation of Van Wet 98.
The amount of each component of the starter solution will vary depending upon, for example, the depth of the flow restricting material formation to be removed.
It has been determined that for each 1,200 feet of depth of an asphalt flow restricting material formation, the following amounts of each chemical component works well:
3 pounds--Sulfamic Acid,
1 pound--Soda Ash,
3 pounds--Van Wet 98,
10 gallons--Sterile Water.
In the process of the present invention to eliminate paraffin formations in the well, as a first step, the chemical components of the first solvent are blended together in the atmospheric tank 10 to obtain an acceptable mixture consistency. The first solvent is then pumped out of the atmospheric tank 10 by the transfer pump 16 through the bypass conduit 44 into the well casing by passing the pressure vessel 12 and electrode chamber 26. This is accomplished by closing valves 20, 45, and 37. The first solvent is allowed to stabilize in situ in the well for a first period of time, on the order, for example of thirty minutes, before the second step is carried out. As the second process step the chemical components of the second solvent are blended together in the atmospheric tank 10 to obtain an acceptable mixture consistency. The second solvent is then pumped out of the atmospheric tank 10 by the transfer pump 16 through the bypass conduit 44 into the outlet or fourth conduit 34 into the well wherein it combines with the first solvent previously pumped into the well. The second solvent is allowed to stabilize with the first solvent in situ in the well for a second period of time, on the order of, for example, twelve hours, during which time the first solvent in combination with the second solvent begins reacting with the paraffin formations. As a third step, the chemical mixture of the first solvent and second solvent along with admixed hydrocarbon liquid product from the well is pumped from the well through the return conduit 46 into the electrode chamber 26. This can be accomplished by closing valve 37 in the outlet conduit 34, opening valves 48 and 50 in the return conduit 46, closing valve 52 and opening valve 32 in the third conduit 28, and activating the pump 56 in the well casing. The voltage and current of the AC generator 60 is adjusted to provide sufficient energy to the electrodes 36 for a sufficient length of time to increase the viscosity of the hydrocarbon liquid, vaporize natural gases in the hydrocarbon liquid and chemical treating liquid, and impart a residual electric field to the hydrocarbon liquid. It has been determined that a voltage of about 100 volts and a potential of 500 amperes works well. The valves 30 and 52 in the third conduit 28 are opened and the valves 36, 38 and 37 in the outlet conduit 34 are opened so that the liquid in the electrode chamber 26 is pumped by air pressure from the pressure vessel 12 through the outlet conduit 37 back into the well. As may be needed, the admixture of first solvent, second solvent, starter solution and hydrocarbon product can be pumped from the well and recirculated back through the electrode chamber 26 and then back to the well.
In the process of the present invention to eliminate asphalt formations in the well, as a first step the chemical components of the first solvent are blended together in the atmospheric tank 10 to obtain an acceptable mixture consistency. The first solvent is then pumped out of the atmospheric tank 10 by the transfer pump 16 through the bypass conduit 44 into the outlet or fourth conduit 34 into the well casing by passing the pressure vessel 12 and electrode chamber 26. This is accomplished by closing valves 20, 45 and 37. The first solvent is allowed to stabilize in situ in the well for a first period of time, on the order of for example thirty minutes, before the second step is carried out. As the second process step the chemical components of the second solvent are blended together in the atmospheric tank 10 to obtain an acceptable mixture consistency. The second solvent is then pumped out of the atmospheric tank 10 by the transfer pump 16 through the bypass conduit 44 into the outlet or fourth conduit 34 into the well wherein it combines with the first solvent previously pumped into the well. The second solvent is allowed to stabilize with the first solvent in situ in the well for a second period of time greater than the first period of time, for example on the order of twelve hours, during which time the first solvent in combination with the second solvent begins reacting with the asphaltic formations. As the third step, the chemical components of the starter solution are blended together in the atmospheric tank 10 to obtain an acceptable mixture consistency. The starter solution is then pumped to the pressure vessel 12 and then to the electrode chamber 26 under the influence of the air pressure in the pressure vessel 12. This is accomplished by opening the valve 20 in the first conduit 14, opening the valves 52 and 53 in the third conduit 28, closing the valve 45 in the bypass conduit 44, and closing the valve 50 in the return conduit 46. The electrodes 58 are activated by the AC generator 60. The electrolysed starter solution, having a residual electric charge or field, is pumped out of the electrode chamber 26 through the fourth conduit 34 under the influence of the compressed air from the pressure vessel 12, into the well wherein it mixes with first solvent and second solvent previously pumped into the well. This is accomplished by opening valves 36, 38 and 37 in the outlet conduit 34. As a fourth step, the chemical mixture of the first solvent, second solvent, and starter solution along with admixed hydrocarbon liquid product from the well is pumped from the well through the return conduit 46 into the electrode chamber 26. This can be accomplished by closing valve 37 in the outlet conduit 34, opening valves 48 and 50 in the return conduit 46, closing valve 52 and opening valve 32 in the third conduit 28, and activating the pump 56 in the well casing. The voltage and current of the AC generator 60 is adjusted to provide sufficient energy to the electrodes 58 for a sufficient length of time to increase the viscosity of the hydrocarbon liquid, vaporize natural gases in the hydrocarbon liquid and the chemical treating liquid, and impart a residual electric field to the hydrocarbon liquid. It has been determined that a voltage of about 100 volts and a potential of 500 amperes works well. The valves 30 and 52 in the third conduit 28 are opened and the valves 36, 38 and 2 in the outlet conduit 34 are opened so that the liquid in the electrode chamber 26 is pumped by air pressure from the pressure vessel 12 through the outlet conduit 34 back into the well.
The process for removing asphalt formations in the well, it is contemplated that, optionally, the first solvent be routed through the electrode chamber 26 wherein it is electrolyzed prior to initially introducing the first solvent into the well.
As may be needed, the admixture of first solvent, second solvent, starter solution, and hydrocarbon product can be pumped from the well and recirculated back through the electrode chamber and then back to the well.
The foregoing detailed description is given primarily for clearness of understanding and no unnecessary limitations are to be understood thereby. | A method for removing flow-restricting matter such as paraffin, asphalts, clays, scales, or gyps from production equipment and producing formation of and in the vicinity of an oil or gas well. The method uses a combination of solutions consisting of mixed solvents and additives such as detergents, surfactants and acids. The solutions are electrolyzed along with the hydrocarbon product of the well in an above-ground reaction chamber. The electrolyzed mixture of solutions and hydrocarbon product are reintroduced immediately down the well casing and into the well formation. | 2 |
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to integrated circuit (IC) devices, and in particular to a lateral double diffused metal-oxide-semiconductor (LDMOS) device and a method for fabricating the same.
Description of the Related Art
Recently, due to the rapid development of communication devices such as mobile communication devices and personal communication devices, wireless communication products such as mobile phones and base stations have been greatly developed. In wireless communication products, high-voltage elements of lateral double diffused metal-oxide-semiconductor (LDMOS) devices are often used as radio frequency (900 MHz-2.4 GHz) related elements therein.
LDMOS devices not only have a higher operating frequency, but they are also capable of sustaining a higher breakdown voltage, thereby having a high output power so that they can be used as power amplifiers in wireless communication products. In addition, due to the fact that LDMOS devices can be formed by conventional CMOS fabrications, LDMOS devices can be fabricated from a silicon substrate which is relatively cost-effective and employs mature fabrication techniques.
In FIG. 1 , a schematic cross section showing a conventional N-type lateral double diffused metal-oxide-semiconductor (LDMOS) device applicable in a radio frequency (RF) circuit element is illustrated. As shown in FIG. 1 , the N-type LDMOS device mainly comprises a P+ type semiconductor substrate 100 , a P− type epitaxial semiconductor layer 102 formed over the P+ type semiconductor substrate 100 , and a gate structure G formed over a portion of the P− type epitaxial semiconductor layer 102 . A P− type doped region 104 is disposed in the P− type epitaxial semiconductor layer 102 under the gate structure G and a portion of the P− type epitaxial semiconductor layer 102 under the left side of the gate structure G, and an N− type drift region 106 is disposed in a portion of the P− type epitaxial semiconductor layer 102 under the right side of the gate structure G. A P+ type doped region 130 and an N+ type doped region 110 are disposed in a portion of the P type doped region 104 , and the P+ doped region 130 partially contacts a portion of the N+ type doped region 110 , thereby functioning as a contact region (e.g. P+ type doped region 130 ) and a source region (e.g. N+ type doped region 110 ) of the N type LDMOS device, respectively, and another N+ type doped region 108 is disposed in a portion of the P− type epitaxial semiconductor layer 102 at the right side of the N− type drift region 106 to function as a drain region of the N type LDMOS device. In addition, an insulating layer 112 is formed over the gate structure G, covering sidewalls and a top surface of the gate structure G and partially covering the N+ type doped regions 108 and 110 adjacent to the gate structure G. Moreover, the N type LDMOS further comprises a P+ type doped region substantially disposed in a portion of the P− type epitaxial semiconductor layer 102 under the N+ type doped region 110 and the P− type doped region 104 under the N+ type doped region 110 . The P+ type doped region 120 physically connects the P− type doped region 104 with the P+ type semiconductor substrate 100 .
During operation of the N type LDMOS device shown in FIG. 1 , due to the formation of the P+ type doped region 120 , currents (not shown) from the drain side (e.g. N+ type doped region 108 ) laterally flow through a channel (not shown) underlying the gate structure G towards a source side (e.g. N+ type doped region 110 ), and are then guided by the P− type doped region 104 and the P+ type doped region 120 , thereby arriving at the P+ type semiconductor substrate 100 , such that problems such as inductor coupling and cross-talk between adjacent circuit elements can be avoided. However, the formation of the P+ type doped region 120 requires the performance of ion implantations of high doping concentrations and high doping energies and thermal diffusion processes with a relatively high temperature above about 900° C., and a predetermined distance D 1 is kept between the gate structure G and the N+ type doped region 110 at the left side of the gate structure G to ensure good performance of the N type LDMOS device. Therefore, formation of the P+ type doped region 120 and the predetermined distance D 1 kept between the gate structure G and the N+ type doped region 110 increase the on-state resistance (Ron) of the N type LDMOS device and a dimension of the N type LDMOS device, which is unfavorable for further reduction of both the fabrication cost and the dimensions of the N type LDMOS device.
BRIEF SUMMARY OF THE INVENTION
Accordingly, an improved lateral double diffused metal oxide semiconductor (LDMOS) device and method for fabricating the same are provided to reduce size and fabrication cost.
An exemplary lateral double diffused metal oxide semiconductor (LDMOS) device comprises: a semiconductor substrate, having a first conductivity type; an epitaxial semiconductor layer formed over the semiconductor substrate, having the first conductivity type; a gate dielectric layer formed over the epitaxial semiconductor layer, having a step-like cross-sectional structure; a gate stack conformably disposed over the gate dielectric layer; a first doped region disposed in a portion of the epitaxial semiconductor layer adjacent to a first side of the gate stack, having the first conductivity type; a second doped region disposed in a portion of the epitaxial semiconductor layer adjacent to a second side of the gate stack opposite to the first side, having a second conductivity type opposite to the first conductivity type; a third doped region disposed in a portion of the first doped region, having the second conductivity type; a fourth doped region disposed in a portion of the second doped region, having the second conductivity type; an insulating layer covering the third doped region, the gate dielectric layer, and the gate stack; a conductive contact formed in a portion of the insulating layer, the third doped region, the first doped region, and the epitaxial semiconductor layer; and a fifth doped region disposed in a portion of the epitaxial semiconductor layer under the conductive contact, having the first conductivity type, wherein the fifth doped region physically contacts the semiconductor substrate and the conductive contact.
An exemplary method for fabricating a lateral double diffused metal oxide semiconductor (LDMOS) device comprises: performing a semiconductor substrate, having a first conductivity type; forming an epitaxial semiconductor layer over the semiconductor substrate, having the first conductivity type; forming a first doped region in a portion of the epitaxial semiconductor layer, having a second conductivity type opposite to the first conductivity type; forming a first dielectric layer over the first doped region in the epitaxial semiconductor layer; forming a second dielectric layer over a portion of the epitaxial semiconductor layer, being adjacent to the first dielectric layer and contacting thereof, wherein the first dielectric layer and the second dielectric layer have different thicknesses; forming a gate stack over a portion of the first dielectric layer and a portion of the second dielectric layer; forming a second doped region in a portion of the epitaxial semiconductor layer adjacent to a first side of the gate stack, having the first conductivity type; forming a third doped region in a portion of the second doped region at the first side of the gate stack, having the second conductivity type opposite to the first conductivity type; forming an insulating layer over the first dielectric layer, the gate stack, and the second dielectric layer; forming a first trench at the first side of the gate stack, wherein the first trench penetrates a portion of the insulating layer, the second dielectric layer, the third doped region, the first doped region, and the epitaxial semiconductor layer; performing a first ion implantation process, forming a fourth doped region in a portion of the epitaxial semiconductor layer exposed by the first trench, wherein the fourth doping region contacts the semiconductor substrate and has the first conductivity type; forming a first conductive contact in the first trench, contacting the fourth doped region; forming an interlayer dielectric layer over the insulating layer and the first conductive contact; forming a second trench at the second side of the gate stack opposite to the first side, wherein the second trench penetrates a portion of the interlayer dielectric layer, the insulating layer, and the second dielectric layer and exposes a portion of the first doped region; performing a second ion implantation process, forming a fifth doped region in a portion of the first doped region exposed by the second trench, wherein the fifth doped region has the second conductivity type; and forming a second conductive contact in the second trench, contacting the fifth doped region.
A detailed description is given in the following embodiments with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
FIG. 1 is schematic cross section of a conventional lateral double diffused metal-oxide-semiconductor (LDMOS) device;
FIGS. 2-8 are schematic cross sections showing a method for fabricating a lateral double diffused metal-oxide-semiconductor (LDMOS) device according to an embodiment of the invention; and
FIG. 9 is schematic cross section of a lateral double diffused metal-oxide-semiconductor (LDMOS) device according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
FIGS. 2-8 are schematic cross sections showing a method for fabricating a lateral double diffused metal-oxide-semiconductor (LDMOS) device applicable for a radio frequency (RF) circuit element according to an embodiment of the invention.
Referring to FIG. 2 , a semiconductor substrate 200 such as a silicon substrate is first provided. In one embodiment, the semiconductor substrate 200 has a first conductivity type such as a P type, and a resistivity of about 0.001-0.005 ohms-cm (Ω-cm). Next, an epitaxial semiconductor layer 202 is formed over the semiconductor substrate 200 . The epitaxial semiconductor layer 202 may comprise epitaxial materials such as silicon, and can be in-situ doped with dopants of the first conductivity type such as P type during the formation thereof, and has a resistivity of about 0.5-1 ohms-cm (Ω-cm). In one embodiment, the resistivity of the epitaxial semiconductor layer 202 is greater than that of the semiconductor substrate 200 .
Referring to FIG. 3 , a pad oxide layer 204 and a pad nitride layer 206 are sequentially formed over the epitaxial semiconductor layer 202 . The pad oxide layer 204 may comprise materials such as silicon dioxide, and the pad nitride layer 206 may comprise materials such as silicon nitride. Next, a patterning process (not shown) comprising photolithography and etching steps is performed, and an opening 208 is formed in a portion of the pad nitride layer 208 . The opening 208 exposes a portion of the underlying pad oxide layer 204 . Next, an ion implantation process 210 is performed on the region exposed by the opening 208 , using the pad nitride layer 206 as an ion implantation mask. The ion implantation process 210 implants dopants of a second conductivity type such as N-type through the portion of the pad oxide layer 206 exposed by the opening 208 , thereby entering into a portion of the epitaxial semiconductor layer 202 .
Referring to FIG. 4 , after performing the ion implantation process 210 (see FIG. 3 ), a doped region 212 is formed in a portion of the epitaxial semiconductor layer 202 , having the second conductivity type opposite to the first conductivity type of the epitaxial semiconductor layer 202 and a dopant concentration of about 5*10 11 -5*10 13 atom/cm 2 . Herein, the doped region 212 functions as a drift-region. Next, an etching process (not shown) such as dry etching is performed, using the pad nitride layer 206 as an etching mask, to remove the portion of the pad oxide layer 204 exposed by the opening 208 , thereby exposing a top surface of the doped region 212 in the epitaxial semiconductor layer 202 . Next, a deposition process (not shown) is performed, forming a dielectric layer 214 over the epitaxial semiconductor layer 202 exposed by the opening 208 . Herein, a top surface of the dielectric layer 214 is slightly above the top surface of the pad nitride layer 206 . However, the top surface of the dielectric layer 214 may be slightly below or planar with the top surface of the pad nitride layer 206 in other embodiments. In one embodiment, the dielectric layer 214 may comprise materials such as silicon oxide, and can be formed by, for example, thermal oxidation.
Referring to FIG. 5 , an etching process (not shown) is performed, using the dielectric layer 214 as an etching mask, to sequentially remove the pad nitride layer 206 and the pad oxide layer 204 over the epitaxial semiconductor layer 202 , thereby exposing a surface of the other portion of the epitaxial semiconductor layer 202 . Herein, during removal of the pad oxide layer 204 , a portion of the dielectric layer 214 may be partially removed. Next, a deposition process (not shown) is performed to form another dielectric layer 216 over the top surface of the epitaxial semiconductor layer 202 not covered by the dielectric layer 214 . In the deposition process for forming the dielectric layer 216 , dielectric materials are also formed over the surface of the dielectric layer 214 , thereby increasing the thickness of the dielectric layer 214 . In one embodiment, the dielectric layer 216 may comprise the same materials as that of the dielectric layer 214 , such as silicon dioxide, and can be formed by a deposition process such as thermal oxidation.
Referring to FIG. 6 , a conductive layer 218 and a mask layer 220 are sequentially and conformably formed over surfaces of the dielectric layer 214 and the dielectric layer 216 , and are then patterned by a patterning process (not shown) comprising photolithography and etching steps into a plurality of separated patterned conductive layers 218 and mask layers 220 . These separated patterned conductive layer 218 and mask layer 220 are respectively illustrated as a gate stack G′. In one embodiment, the conductive layer 218 may comprise conductive materials such as doped polysilicon, and the mask layer 220 may comprise masking materials such as silicon dioxide and silicon nitride. In addition, a plurality of separated openings 222 are formed between these gate stacks G′, respectively. As shown in FIG. 6 , the openings 222 respectively expose a portion of the dielectric layer 216 and a portion of the dielectric layer 214 , and one of the gate stacks G′ partially extends over a portion of the adjacent dielectric layers 214 and 216 . The conductive layer 218 in the gate stack G′ that extends over a portion of the adjacent dielectric layers 214 and 216 may function as a gate electrode layer, and the portion of the dielectric layers 214 and 216 covered by this conductive layer 218 may function as a gate dielectric layer and may have a step-like cross-sectional structure. Next, an ion implantation process (not shown) is performed, using the patterned conductive layer 218 , the patterned mask layer 220 , and the dielectric layer 214 as an implantation mask, to implant dopants of the first conductivity type such as P type to penetrate the dielectric layer 216 exposed by one of the openings 222 into the epitaxial semiconductor layer 202 , thereby forming a doped region 224 in the epitaxial semiconductor layer 202 . Herein, the doped region 224 has the first conductivity type such as p-type and has a dopant concentration of about 1*10 13 -5*10 14 atom/cm 2 . Next, a layer of dielectric layer is conformably deposited and an etching-back process (both not shown) is performed, thereby forming a spacer 226 in each of the openings 222 and on a sidewall of the gate stacks G′. Formation of the spacers 226 reduce the openings 222 into other openings 228 of a smaller size. Next, an ion implantation process (not shown) is performed, using the spacers 226 , the gate stack G′ and the dielectric layer 214 as an ion implantation mask, to implant dopants of the second conductive type such as N-type to penetrate the dielectric layer 216 exposed by one of the openings 222 , thereby forming a doped region 230 in a portion of the doped region 224 . Herein, the doped region 230 may function as a source/drain region, and the bottom surface and sidewall surfaces of the doped region 230 are surrounded by the doped region 224 . The doped region 224 may have a second conductivity type such as N-type and has a dopant concentration of about 1*10 15 -5*10 15 atom/cm 2 .
Referring to FIG. 7 , an insulating layer 232 is conformably formed over the dielectric layer 200 to cover the surfaces of the gate stacks G′, the spacers 226 , the dielectric layer 216 and the dielectric layer 214 . The insulating layer 232 may comprise insulating materials such as silicon dioxide, and can be formed by a process such as chemical vapor deposition (CVD). Next, a patterning process (not shown) comprising photolithography and etching steps is performed to form a trench 234 . As shown in FIG. 7 , the trench 234 has a depth H (to a top surface of the epitaxial semiconductor layer 202 ) and penetrates a portion of the insulating layer 232 , the doped regions 224 and 230 , and the epitaxial semiconductor layer 202 thereunder. Next, an ion implantation process 236 is performed, using the insulating layer 232 as an implantation mask, to implant dopants of the first conductivity type such as P-type to a portion of the epitaxial semiconductor layer 202 exposed by the trench 234 , thereby forming a doped region 238 therein. After performing a thermal diffusion process (not shown), the doped region 238 physically contacts the semiconductor substrate 200 and covers the bottom surface and portions of sidewalls of the trench 234 . Herein, the doped region 238 may have the first conductivity type such as P-type and has a dopant concentration of about 1*10 15 -5*10 15 atom/cm 2 .
Referring to FIG. 8 , a conductive layer 240 and another conductive layer 242 are then sequentially deposited over the structure shown in FIG. 7 , wherein the conductive layer 240 is conformably formed over surfaces of the insulating layer 232 and the bottom surface and the sidewalls of the epitaxial semiconductor layer 202 exposed by the trench 234 , and the conductive layer 242 is formed over the surfaces of the conductive layer 240 , thereby filling the trench 234 . In one embodiment, the conductive layer 240 may comprise conductive materials such as Ti—TiN alloy, and the conductive layer 242 may comprise conductive materials such as tungsten. Next, an etching process (not shown) is performed to remove the portion of the conductive layers 240 and 242 above the insulating layer 232 , thereby leaving the conductive layers 240 and 242 in the trench 234 as a conductive contact. Next, an inter-layer dielectric (ILD) layer 244 is blanketly deposited to cover top surfaces of the insulating layer 232 and the conductive layers 240 and 242 . The ILD layer 234 may comprise dielectric materials such as silicon oxide or spin-on-glass (SOG), and may be planarized to have a planar surface. Next, a patterning process (not shown) comprising photolithography and etching steps is performed to form a trench 246 in a portion of the dielectric layer 214 , the insulating layer 232 and the ILD layer 244 over a portion of the doped region 212 , and the trench 246 exposes a portion of the doped region 212 . Next, an ion implantation process (not shown) is performed, using a suitable implantation mask, to implant dopants of the second conductivity type such as N-type, thereby forming a doped region 248 in a portion of the doped region 212 . Herein, the doped region 248 may function as a source/drain region, and the bottom surface and sidewalls thereof are surrounded by the doped region 212 , and the doped region 248 may have the second conductivity type such as N-type and has a dopant concentration of about 1*10 15 -5*10 15 atom/cm 2 . Next, a conductive layer 250 and another conductive layer 252 are sequentially deposited, and the conductive layer 250 is conformably formed over the surfaces of the ILD layer 244 and the sidewalls exposed by the trench 246 , and the conductive layer 252 is formed over the surface of the conductive layer 250 , thereby filling the trench 246 . The portion of the conductive layers 250 and 252 formed in the trench 246 may function as a conductive contact. In one embodiment, the conductive layer 250 may comprise conductive materials such as Ti—TiN alloy, and the conductive layer 252 may comprise conductive materials such as tungsten. Therefore, an exemplar LDMOS device is substantially fabricated, as shown in FIG. 8 .
In addition, as shown in FIG. 9 , another exemplar LDMOS device is illustrated. The LDMOS device in FIG. 9 is similar to the LDMOS device shown in FIG. 8 , and can be formed by the processes shown in FIGS. 1-8 . Herein, the etching process for removing the conductive layers 240 and 242 shown in FIG. 8 is replaced by a patterning process comprising photolithgraphy and etching steps, such that the conductive layers 240 and 242 are patterned and portions thereof now remain over the insulating layer 232 .
In one embodiment, one of the gate stacks G′ and the doped regions 230 and 248 of the LDMOS device shown in FIGS. 8-9 may be properly electrically connected, and the regions of the first conductivity type can be P type regions, and the regions of the second conductivity type can be N type regions, such that the formed LDMOS device herein is an N type LDMOS device. At this time, the doped region 230 may function as a source region and the doped region 248 may function as a drain region. In this embodiment, during operation of the LDMOS device shown in FIGS. 8-9 , currents from the drain side (e.g. the doped region 248 ) may flow laterally toward the source side (e.g. doped region 230 ) by the guidance of the doped region 224 , the conductive layers 240 and 242 , and the doped region 238 , and then arrive at the semiconductor substrate 200 , such that problems such as inductor coupling and cross-talk between adjacent circuit elements can be prevented. In this embodiment, due to the formation of the conductive layers 240 and 242 formed in the trench 234 (see FIG. 7 ) and the doped region 238 embedded in the epitaxial semiconductor layer 202 and contacting the semiconductor substrate 200 , such that an ion implantation with high dosages and high energies for forming the P+ type doped region 120 as shown in FIG. 1 can be avoided, a predetermined distance D 2 between the gate structure G and the doped region 234 at the right side of the trench 232 can be less than the predetermined distance D 1 as shown in FIG. 1 . Therefore, when compared with the N type LDMOS device as shown in FIG. 1 , the N type LDMOS device shown in FIGS. 8-9 may have the advantages of reduced size and fabrication cost, and formation of the doped region 238 , and the conductive layers 240 and 242 also helps to reduce the on-state resistance (Ron) of the N type LDMOS device. Moreover, since the portion of the dielectric layers 214 and 216 (i.e. the gate dielectric layer) covered by the gate stack G′ formed between the doped regions 230 and 248 of the LDMOS device shown in FIGS. 8-9 has a step-like cross-sectional structure, such that reduction of the parasitic capacitance and increase of the breakdown voltage of the LDMOS device shown in FIGS. 8-9 can be achieved.
In addition, in another embodiment, the regions of the first conductivity type of the LDMOS device shown in FIGS. 8-9 can be N type regions, and the regions of the second conductivity type can be P type regions, such that the LDMOS device formed herein can be a P type LDMOS device.
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 to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements. | A lateral double diffused metal-oxide-semiconductor device includes: an epitaxial semiconductor layer disposed over a semiconductor substrate; a gate dielectric layer disposed over the epitaxial semiconductor layer; a gate stack disposed over the gate dielectric layer; a first doped region disposed in the epitaxial semiconductor layer from a first side of the gate stack; a second doped region disposed in the epitaxial semiconductor layer from a second side of the gate stack; a third doped region disposed in the first doping region; a fourth doped region disposed in the second doped region; an insulating layer covering the third doped region, the gate dielectric layer, and the gate stack; a conductive contact disposed in the insulating layer, the third doped region, the first doped region and the epitaxial semiconductor layer; and a fifth doped region disposed in the epitaxial semiconductor layer under the conductive contact. | 7 |
RELATED APPLICATIONS
This application is a continuation of U.S. Non-Provisional application Ser. No. 12/238,383 filed Sep. 25, 2008 now U.S. Pat. No. 7,898,299 issued Mar. 1, 2011, the contents of which are incorporated by reference herein.
TECHNICAL FIELD
This disclosure relates generally to electronic circuits, and more particularly to current sense amplifiers.
BACKGROUND
Many electronic systems include load circuitry that requires a regulated flow of current to operate properly. In order to control the current flow to the load circuitry, these electronic systems typically also include a current measurement device to measure the current flow to the load circuitry and a current control device to control or regulate current flow to the load circuitry. Thus, the current measurement device measures the current being provided to the load circuitry, the measurement is fed back to the current control device for adjustment of the current being provided to the load circuitry.
High-side current sense amplifiers are one common type of current measurement device utilized by the electronic systems. These high-side current sense amplifiers typically operate to sense a voltage difference across a high-side sense resistor that is coupled with a load circuitry. High-side current sense amplifiers can be constructed or configured to trade-off various performance options, such as gain accuracy and operating frequency or bandwidth.
SUMMARY
According to an embodiment, a system includes a current sense amplifier to receive an input voltage based on a sense current provided to load circuitry for operation. The current sense amplifier is configured to generate an output voltage from the input voltage based, at least in part, on one or more reconfigurable characteristics of the current sense amplifier. The system also includes a microcontroller to compare the output voltage from the current sense amplifier to one or more programmable thresholds. The microcontroller is configured to direct a current controller to regulate the sense current provided to the load circuitry according to the comparison.
According to an embodiment, a method comprising receiving an input voltage based on a sense current provided to load circuitry for operation, generating an output voltage from the input voltage based, at least in part, on one or more reconfigurable characteristics of a current sense amplifier, comparing the output voltage from the current sense amplifier to one or more programmable thresholds, and regulating the sense current provided to the load circuitry according to the comparing.
According to an embodiment, an apparatus comprising a first amplification circuit to receive an input voltage that corresponds to a current flowing through a sense resistor to load circuitry. The first amplification circuit is configured to amplify the input voltage according to one or more adjustable characteristics that are configurable by a microcontroller. The apparatus further comprising a second amplification circuit to generate an output voltage by amplifying the input voltage from the first amplification circuit according to one or more adjustable characteristics that are configurable by the microcontroller. The microcontroller utilizes the output voltage to regulate current provided to the load circuitry.
DESCRIPTION OF THE DRAWINGS
The invention may be best understood by reading the disclosure with reference to the drawings.
FIG. 1 is a block diagram of an example electronic system including a reconfigurable current sense amplifier according to embodiments of the invention.
FIG. 2 is a block diagram of an example reconfigurable current sense amplifier according to embodiments of the invention.
FIGS. 3A-3B are diagrams illustrating operational embodiments of electronic system and the reconfigurable current sense amplifier shown in FIGS. 1 and 2 .
FIG. 4 is a block diagram of an example reconfigurable current sense amplifier with self powering functionality according to embodiments of the invention.
FIG. 5 is a block diagram of an example reconfigurable current sense amplifier with a cross protection circuit according to embodiments of the invention.
FIG. 6 is an example operational flowchart for the electronic system as shown in FIGS. 1-5 .
DETAILED DESCRIPTION
A programmable system on a chip (PSOC) or other electronic system can control the operation of various load circuits, such as light-emitting diode (LED) arrays or other current-driven circuits. Since these load circuits often have differing operational requirements, such as gain accuracy and operating frequency or bandwidth tradeoffs, the programmable system on a chip includes at least one reconfigurable current sense amplifier to ensure the programmable system on a chip can accommodate the various load circuits. Embodiments are shown and described below in greater detail.
FIG. 1 is a block diagram of an example electronic system 100 including a reconfigurable current sense amplifier 200 according to embodiments of the invention. Referring to FIG. 1 , the electronic system 100 generates and regulates a sense current 114 that powers load circuitry 120 . The load circuitry 120 can be any current-driven device, such as a light-emitting diode (LED) array, control circuitry, or other load device that includes inductive and/or resistive electronic components. Although FIG. 1 shows the load circuitry 120 as forming a part of the electronic system 100 , in some embodiments, the load circuitry 120 can be located externally to the electronic system 100 .
The electronic system 100 includes a sense resistor 110 coupled in series with the load circuitry 120 . The sense resistor 110 can receive a power supply voltage 102 and induce the sense current 114 to be provided to the load circuitry 120 . The electronic system 100 includes a current controller 130 to adjust the magnitude of the sense current 114 that is driven through a sense resistor 110 . In some embodiments, the current controller 130 includes a field effect transistor (FET), such as an N-type FET or other device that can regulate or control current flow through the load circuitry 120 . Thus, the combination of the sense resistor 110 and the current controller 130 can dictate the magnitude of the sense current 114 provided to the load circuitry 120 .
The electronic system 100 includes a reconfigurable current sense amplifier 200 to detect a sense voltage 112 or input voltage across the sense resistor 110 . The sense voltage 112 corresponds to the magnitude of sense current 114 generated by the current controller 130 , the sense resistor 110 , and the power supply voltage 102 . In some embodiments, the reconfigurable current sense amplifier 200 can receive the sense voltage 112 as a pair of inputs, one corresponding to the node of the sense resistor 110 coupled to the power supply voltage 102 and the other corresponding to the node of the sense resistor 110 coupled to the load circuitry 120 .
The reconfigurable current sense amplifier 200 can amplify the sense voltage 112 to generate an output voltage 205 according to one or more adjustable characteristics. For instance, the reconfigurable current sense amplifier 200 has an adjustable amplification gain, an adjustable input offset, and adjustable bandwidth compensation. Embodiments of the reconfigurable current sense amplifier 200 and these adjustable characteristics will be described below in greater detail.
The electronic system 100 includes a microcontroller 140 to control operations in the electronic system 100 . The microcontroller 140 can be a processor, microprocessor, or other controlling device, and in some embodiments, can be implemented in firmware or as a discrete set of hardware elements. Although not shown in FIG. 1 , the microcontroller 140 can be coupled to a computer or machine readable medium or other memory device that includes instructions, when executed by the microcontroller 140 , can cause the microcontroller 124 to perform various functions or operations.
The microcontroller 140 can receive the output voltage 205 from the reconfigurable current sense amplifier 200 and generate current control signals 146 for transmission to the current controller 130 responsive to the output voltage 205 . The current control signals 146 can activate or deactivate the current controller 130 to drive the sense current 114 . In some embodiments, the microcontroller 140 can compare the output voltage 205 to one or more programmable thresholds to determine which current control signals 146 to provide to the current controller 130 .
The microcontroller 140 can generate configuration signals 142 , which direct configuration of adjustable characteristics in the reconfigurable current sense amplifier 200 . In some embodiments, the reconfigurable current sense amplifier 200 can have register electronically trimmable components that are reconfigured according to the configuration signals 142 .
The electronic system 100 includes a reference current generator 150 to provide reference currents 155 to the reconfigurable current sense amplifier 200 , e.g., in response to reference controller signals 144 from the microcontroller 150 . These reference currents 155 can be used to help power the reconfigurable current sense amplifier 200 , as will be shown and described below in greater detail.
FIG. 2 is a block diagram of an example reconfigurable current sense amplifier 200 according to embodiments of the invention. Referring to FIG. 2 , the reconfigurable current sense amplifier 200 can include multiple stages, such as a first current sense amplifier stage 210 and a second current sense amplifier state 220 . The first current sense amplifier stage 210 is coupled to the sense resistor 110 to receive the sense voltage 112 , for example, on a pair of input lines. In some embodiments, the first current sense amplifier stage 210 receives two voltage inputs from the sense resistor 110 , where the voltage difference between the two voltage inputs is the sense voltage 112 .
The first current sense amplifier stage 210 can include a first resistor RP 211 coupled between a higher voltage side of the sense resistor 110 and an operational amplifier 212 . The lower voltage side of the sense resistor 110 can be coupled to another terminal of the operational amplifier 212 . In some embodiments, an adjustable input offset 213 can be coupled between the lower voltage side of the sense resistor 110 and the other terminal of the operational amplifier 212 .
The first current sense amplifier stage 210 can include a transistor 214 , such as a PMOS transistor, that when activated by an output of the operational amplifier 212 , generate a stage one output. The first current sense amplifier stage 210 also include a variable resistor RL 215 that is coupled to the stage one output and a ground.
The configuration of the first current sense amplifier stage 210 allows the sense voltage 112 detected across the sense resistor 110 to be amplified according to Equation 1.
V StageOneOut = R L R P V Sense Equation 1
Thus, the first current sense amplifier stage 210 amplifies the sense voltage 112 input into the system according a ratio between the two resistors, RP 211 and RL 213 , in the first current sense amplifier stage 210 .
In some embodiments, the microcontroller 140 can provide configuration signals 142 to the reconfigurable current sense amplifier 200 that adjust the stage one output. For instance, the configuration signals 142 can adjust the resistance value of the variable resistor RL 215 , which may directly modify the amplification of the sense voltage 112 , as the resistance ratio shown in Equation 1 may change. The configuration signals 142 can also adjust the input offset 213 to alter the difference between the input voltages that are provided to the operational amplifier 212 , thus effectively changing the value of the sense voltage 112 that is amplified by the first current sense amplifier stage 210 .
The second current sense amplifier stage 220 includes an operational amplifier 222 that receives the stage one output at one terminal. The output of the operational amplifier 222 is coupled to multiple resistors, RX 223 and RY 224 , arranged in series. A node between the two resistors RX 223 and RY 224 is coupled as a feedback to the other terminal of the operational amplifier 222 . In some embodiments, an input offset 225 can be coupled between the node between the two resistors RX 223 and RY 224 and the other terminal of the operational amplifier 222 .
The configuration of the second current sense amplifier stage 220 allows the stage one output to be amplified according to Equation 2.
V
Output
=
(
1
+
R
X
R
Y
)
V
StageOneOut
Equation
2
Thus, the second current sense amplifier stage 220 amplifies the stage one output according a ratio between the two resistors, RX 223 and RY 224 , in the second current sense amplifier stage 210 . In some embodiments, the microcontroller 140 can provide configuration signals 142 to the reconfigurable current sense amplifier 200 that adjust the characteristics of the second current sense amplifier stage 220 to vary the output voltage 205 . For instance, the configuration signals 142 can adjust the resistance value of the variable resistor RY 2234 which may directly modify the amplification of the stage one output, as the resistance ratio shown in Equation 2 may change. The configuration signals 142 can also adjust the input offset 225 to alter the difference between the input voltages that are provided to the operational amplifier 222 .
Thus, the output voltage 205 of the reconfigurable current sense amplifier 200 can be expressed according to Equation 3.
V
Output
=
(
1
+
R
X
R
Y
)
(
R
L
R
P
)
V
Sense
Equation
3
The second current sense amplifier stage 220 can also include a bandwidth compensation circuit 221 that is coupled between the stage one output and the operational amplifier 222 . The bandwidth compensation circuit 221 can dampen the effect of noise in the power supply voltage 102 that is amplified in the first current sense amplification stage 210 . By dampening the noise in the power supply voltage, the reconfigurable current sense amplifier 200 can optimize a Power Supply Rejection Ratio (PSRR) and limit subsequent swings in the sense current 114 due to the power supply noise. In some embodiments, the bandwidth compensation circuit 221 can include a variable capacitor, for example, that is adjustable according to the configuration signals 142 from the micro controller 140 .
The reconfigurable current sense amplifier 200 can include a bypass circuit 230 that can optionally bypass the second current sense amplifier stage 220 . In some embodiments, the configuration signals 142 from the microcontroller 140 can control the operation of the bypass circuit 230 . Thus, when the bypass circuit 230 is activated to bypass the second current sense amplifier stage 220 , the stage one output becomes the output voltage 205 . In some embodiments, the bypass circuit 230 can be activated to bypass the second current sense amplifier stage 220 during lower frequency operation of the electronic system, while during higher frequency operation the bypass circuit 230 can be set to have the second stage output become the output voltage 205 .
FIGS. 3A-3B are diagrams illustrating operational embodiments of electronic system 100 and the reconfigurable current sense amplifier 200 shown in FIGS. 1 and 2 . Referring to FIGS. 3A and 3B , the diagram 300 A discloses a lower frequency operation for the electronic system 100 , and diagram 300 B discloses a higher frequency operation for the electronic system 100 . As discussed above, in FIGS. 1 and 2 , the microcontroller 140 directs the current controller 130 to activate and deactivate based, at least in part, on the output voltage 205 received from the reconfigurable current sense amplifier 200 . The microcontroller 140 compares the output voltage 205 to one or more thresholds, for example, an upper threshold and a lower threshold, to determine when to activate or deactivate the current controller 130 .
When the current controller 130 is activated, for example, responsive to current control signals 146 from the microcontroller 140 , the sense current 114 (and corresponding sense voltage 112 and output voltage 205 ) increases over time. The microcontroller 140 can compare the output voltage 205 to the upper threshold to determine when to direct the current controller 130 to deactivate. When the current controller 130 is deactivated, for example, responsive to current control signals 146 from the microcontroller 140 , the sense current 114 (and corresponding sense voltage 112 and output voltage 205 ) decreases over time. The microcontroller 140 can compare the output voltage 205 to the lower threshold to determine when to direct the current controller 130 to activate again. The activation and deactivation of the current controller 130 generates an oscillation of the sense current 114 , sense voltage 112 , and the output voltage 205 , which is known as the operational frequency of the electronic system 100 .
The operational frequency of the electronic system 100 can be modified by the microcontroller 140 by adjusting the thresholds and/or by reconfiguring the current sense amplifier 200 . For instance, when the thresholds are positioned closer together, less time can required before the current controller 130 is activated or deactivated, thus increasing the operational frequency. Similarly, when the thresholds are positioned farther apart, more time can required before the current controller 130 is activated or deactivated, thus increasing the operational frequency.
Reconfiguring the current sense amplifier 200 to adjust the gain can also modify the operational frequency of the electronic system 100 . Since the slope of the output voltage 205 , when the current controller 130 is activated, is at least in part dictated by the gain of the reconfigurable current sense amplifier 200 , any change in slope can also prompt activation or deactivation of the current controller 130 . As shown, in FIG. 3B , the gain of the reconfigurable current sense amplifier 200 was increased, which also increased the positive slope of the output voltage 205 over time, and thus increased the operational frequency of the electronic system 100 .
Other adjustments to the reconfigurable current sense amplifier 200 , such as modifying the input offsets 213 and 225 into the operational amplifiers 212 and 222 , respectively, activating the bandwidth compensation circuit 221 , and/or bypassing the second current sense amplifier stage 220 , can also affect the waveforms illustrated in FIGS. 3A and 3B . For instance, adjustment to the input offset can alter the DC level of the waveform by raising or lowering the waveform along the Y-axis. Input offset adjustment can also alter the duty cycle of the waveform, allowing system designers or programmers to maximize power efficiency by limiting the time that the current controller 130 is activated.
FIG. 4 is a block diagram of an example reconfigurable current sense amplifier 200 with self powering functionality according to embodiments of the invention. Referring to FIG. 4 , the reconfigurable current sense amplifier 200 can include circuitry that powers the operational amplifiers 212 and 222 from the high node of the sense voltage 112 , i.e., utilizes the high node of the sense voltage 112 as an elevated power supply 408 and generates an elevated analog ground 406 from the elevated power supply 408 .
The reconfigurable current sense amplifier 200 includes a power resistor 410 that is coupled to receive the elevated power supply 408 . A current source 420 can draw current through the power resistor 410 to induce a voltage drop across the power resistor 410 . In some embodiments, a voltage drop across the power resistor 410 is approximately equal to 6V. This voltage drop lowers the voltage level of the elevated power supply for use as an elevated analog ground 406 .
The reconfigurable current sense amplifier 200 includes a first transistor 402 to generate the elevated analog ground 406 responsive to receiving the elevated power supply with the voltage drop at its gate region. In some embodiments, the first transistor 402 can be a PMOS transistor. The reconfigurable current sense amplifier 200 includes a second transistor 404 can be coupled between the first transistor 402 and a ground, with its gate region configured to receive an enable signal 401 . In some embodiments, the second transistor 404 can be a NMOS transistor. When the enable signal 201 is activated, the first transistor 402 can provide the elevated analog ground 406 to the operational amplifier 212 .
FIG. 5 is a block diagram of an example reconfigurable current sense amplifier 200 with a cross protection circuit 510 according to embodiments of the invention. Referring to FIG. 5 , the reconfigurable current sense amplifier 200 includes a cross protection circuit 510 to help ensure a voltage difference received by the operational amplifier 212 at its two input terminals does not exceed a predetermined level.
The cross protection circuit 510 can include resistors coupled in series with the two input lines coupling to the input terminals of the operational amplifier 212 . The cross protection circuit 510 can also include diodes that cross-connect between the two input lines. During normal operation the diodes remain inactive, i.e., do not pass current or voltage to the other input line that is sufficient enough to effect operation. When the voltage difference between the two input lines exceeds a predetermined level, at least one of the diodes activates, to substantially equalize the voltage on the two input lines. The cross protection circuit 510 ensures that the voltage difference received by the operational amplifier 212 at its two input terminals is sufficiently large to affect the operation of the operational amplifier 212 . Thus, the cross protection circuit 510 improves the robustness of the reconfigurable current sense amplifier 200 during its operational life.
FIG. 6 is an example operational flowchart for the electronic system 100 as shown in FIGS. 1-5 . Referring to FIG. 6 , at a block 610 , the electronic system 100 receives an input voltage or sense voltage 112 based on a sense current 114 provided to load circuitry 120 .
A sense resistor 110 can receive a power supply voltage 102 and induce the sense current 114 to be provided to the load circuitry 120 . The electronic system 100 includes a current controller 130 to adjust the magnitude of the sense current 114 that is driven through a sense resistor 110 . Thus, the combination of the sense resistor 110 and the current controller 130 can dictate the magnitude of the sense current 114 provided to the load circuitry 120 .
The reconfigurable current sense amplifier 200 can detect the sense voltage 112 or input voltage across the sense resistor 110 . The sense voltage 112 corresponds to the magnitude of sense current 114 generated by the current controller 130 , the sense resistor 110 , and the power supply voltage 102 . In some embodiments, the reconfigurable current sense amplifier 200 can receive the sense voltage 112 as a pair of inputs, one corresponding to the node of the sense resistor 110 coupled to the power supply voltage 102 and the other corresponding to the node of the sense resistor 110 coupled to the load circuitry 120 .
In a next block 620 , the electronic system 100 generates an output voltage 205 from the input voltage 112 based, at least in part, on one or more reconfigurable characteristics of a current sense amplifier 200 .
In some embodiments, the electronic system 100 can set an adjustable gain associated with the current sense amplifier 200 , and amplify the input voltage 112 according to the adjustable gain to generate the output voltage 205 . The electronic system 100 can also set an input voltage offset associated with the current sense amplifier, and amplify the input voltage according to the input voltage offset to generate the output voltage.
In the next blocks 630 and 640 , the electronic system 100 compares the output voltage 205 from the reconfigurable current sense amplifier 200 to one or more programmable thresholds, and regulates the sense current 114 provided to the load circuitry 120 according to the comparing.
In some embodiments, the electronic system 100 can dictate an operational frequency associated with the sense current 114 based, at least in part, on an upper threshold and a lower threshold. For instance, the microcontroller 140 can compare the output voltage 205 to the upper threshold, and can cease driving the sense current 114 through the load circuitry 140 when the output voltage 205 meets or exceeds the upper threshold. In some embodiments, the microcontroller 140 can prompt the current controller 130 to deactivate, and thus cease driving the sense current 114 .
The microcontroller 140 can also compare the output voltage 205 to the lower threshold, and can drive the sense current 114 through the load circuitry 140 when the output voltage 205 meets or exceeds the lower threshold. In some embodiments, the microcontroller 140 can prompt the current controller 130 to activate, and thus drive the sense current 114 . The switching between the activation and deactivation of the current controller 130 over time can cause the sense current 114 , the sense voltage 112 , and the output voltage 205 to oscillate, defining the operating frequency of the electronic system 100 .
One of skill in the art will recognize that the concepts taught herein can be tailored to a particular application in many other advantageous ways. In particular, those skilled in the art will recognize that the illustrated embodiments are but one of many alternative implementations that will become apparent upon reading this disclosure.
The preceding embodiments are exemplary. Although the specification may refer to “an”, “one”, “another”, or “some” embodiment(s) in several locations, this does not necessarily mean that each such reference is to the same embodiment(s), or that the feature only applies to a single embodiment. | A system includes a current sensor to receive an input signal based on a sense current provided to load circuitry. The current sensor is configurable to generate an output signal from the input signal based, at least in part, on one or more configurable characteristics of the current sensor. The system also includes a processing element to compare the output signal from the current sensor to one or more programmable parameters. The processing element is configurable to direct a current controller to regulate the sense current provided to the load circuitry according to the comparison, and is further configurable to set a configurable parameter associated with the current sense amplifier. | 7 |
This application is a continuation of Ser. No. 08/878 894, filed Jun. 19, 1997.
FIELD OF THE INVENTION
The present invention generally relates to a system and process for managing the production of building materials which increases efficiency, eliminates excess waste, and reduces costs. More particularly, the present invention relates to a system and process for continuously producing lumber of various predetermined grades and lengths by cutting off a continuous line of lumber instead of handling several different lengths and grades of lumber to arrive at the lumber pieces having the predetermined grades and length. Futher, by cutting off of a continuous line of lumber, the present invention relating to a system and process for managing the production of lumber eliminates the trim end waste that is associated with handling and cutting several different lengths and grades of lumber to arrive at the required or ordered lumber pieces of predetermined lengths and grades.
BACKGROUND OF THE INVENTION
Methods and process for continuously finger jointing pieces of lumber end-to-end in order to create a continuous line of lumber which can be cut to desired lengths are well known in the prior art. For example, U.S. Pat. No. 3,927,705 issued to Cromeens et al. discloses methods and means for the continuous vertical finger jointing of lumber. In the Cromeens et al. patent reference, the ends of individual short timbers are conveyed transversely along their longitudinal axis in an abutting side-by-side on-edge relationship or in a solid sheet-like array throughout the finger shaping operations and application of adhesive to one end of each timber. The timbers are maintained in right angular relation to their longitudinal axis of travel and are then assembled end-to-end during linear conveyance to a final step where they are cut to desired lenght. Futher, another patent issued to Strickler, namely U.S. Pat. No. 3,262,723, describes a process for producing end jointed lumber wherein the continuous resulting lumber can be cut into desired lengths.
U.S. Pat. No. 3,769,771 issued to Shannon et al. discloses a structural truss having upper and lower wooden chords that are separated along their lengths by vertical wooden struts. A finger jointing machine is used to create continuous lengths of chords and a paper membrane having an adhesive backing is applied to the underside of the chords by a pressure roll. Precut strut members are inserted downwardly between the continuous lengths of chords, and on top of the adhesive backed membrane. A second adhesive backed membrane is applied to the upper faces of the chords and struts and the adhesive backed membranes which contain the loosely assembled truss frame are then cured thereby securing the membranes and truss frame elements together. The continuous one piece truss frame is then cut into predetermined lengths.
Another patent, U.S. Pat. No. 4,248,280 issued to Taylor, describes a method and machine structure for finger jointing lumber. More specifically, this patent reference discloses a continuous process for joining incoming random lengths of lumber to form a continuous outgoing length of lumber which can be cut into desired lengths. The process includes the steps of i) clamping the ends of two pieces of lumber at a predetermined distance apart from one another, ii) trimming the end of the lumber pieces using a trim saw, iii) simultaneously preshaping the opposing board ends to form opposing and complimentary angled finger members using a single axis preshaper saw, iv) further shaping and forming the opposing angled finger members using a heated die to densify and lengthen the angled finger members, v) simultaneously applying adhesive material to the angled finger members, and vi) jamming the finger members of the opposing board ends in an interlocking relationship for a predetermined period of time.
Several other prior art patents, such as U.S. Pat. No. 3,942,233, U.S. Pat. No. 4,095,634, and U.S. Pat. No. 3,692,340, disclose methods and apparatus for finger jointing lumber. Still other prior art patents, e.g. U.S. Pat. No. 3,813,842, U.S. Pat. No. 3,702,050, U.S. Pat. No. 3,452,502 and U.S. Pat. No. 4,005,556, disclose methods and apparatus directed to wood truss structures, wood truss joints, and truss framed housing comprising preassembled frames.
Conventional wooden trusses comprise an assemblage of lumber members which form a rigid framework. Roof and floor trusses in the building industry comprise long upper and lower wooden chords that are separated by a combination of vertical and diagonal wooden struts that are joined to the chords by nails or metal truss connector plates. The wooden members which comprise the truss must be cut to predetermined lengths with their ends sometimes cut at predetermined angles depending upon the resulting location of the truss in the building structure. Accordingly, a process which efficiently and effectively cuts all of the wooden members required for any given structural truss would greatly reduce the cost and time involved in preparing a lumber order for that given truss, and at the same time eliminate unnecessary waste lumber material associated with processing the lumber for that truss.
Although the prior art patents disclose methods and apparatus for continuously finger jointing pieces of lumber end-to-end in order to create a continuous line of lumber which can be cut to desired lengths, none of the prior art patents addresses the material handling problems associated with cutting and preparing the different wooden members required for a given truss structure. For example, although different lengths of a given width and grade of lumber may be cut from a continuous line of lumber of that same width and grade, a completely different grade and width may be required for another wooden member within a given truss. This would require the handling and processing of a different grade and width of lumber. To date, no one has conceived of a method or process for streamlining the cutting and processing of the wooden members required for building a given truss which eliminates the need for handling several different lengths of varying grades of lumber. Accordingly, there is a need for a method or process for managing the cutting and shaping of wooden members which comprise a given truss which reduces the manpower and increases the efficiency of the equipment needed for the process by eliminating the need for handling several different lengths of lumber of varying grades, which eliminates waste by eliminating the majority of the lumber which comprises the trim ends associated with trimming the varying lengths of lumber, and which increases production efficiency by enabling the equipment involved in the material management process to operate without significant downtime or waiting time.
The system and process for material management of the present invention may also be used in conventional light frame construction of housing. In other words, the system and process for material management of the present invention may also be used to efficiently cut and shape all of the wooden members or elements required for a preassembled rigid framework such as a floor truss, a roof truss, or a wall truss, or a preassembled rigid framework which combines floor, wall and roof truss components into a rigid structure for light construction.
SUMMARY OF THE INVENTION
It is a principle object of the present invention to provide a system and process for the management of building materials in constructing preassembled rigid frameworks such as trusses.
It is another object of the present invention to provide a system and process for managing building materials which results in better and more efficient use of manpower and processing equipment.
It is still another object of the present invention to provide a system and process for the managing building materials which reduces or eliminates waste of the building materials that are being processed.
It is yet another object of the present invention to provide a system and process for managing building materials which drastically reduces the costs involved in managing the building materials to produce an end result.
Still another object of the present invention is to provide a system and process for managing the cutting and shaping of wooden members that comprise a truss which reduces the manpower necessary for the process and increases the efficiency of the equipment necessary for the process.
Yet another object of the present invention is to provide a system and method for managing the cutting and shaping of wooden members that comprise a truss which is more efficient and cost effective over the existing conventional method for the same process by eliminating the need for handling several different lengths of lumber having several different grades for each length.
It is still another object of the present invention to provide a system and method for efficiently and effectively managing the cutting and shaping of wooden building members which includes means for treating the wooden building members with a fire retardant.
The present invention is directed to a system and method for managing building materials which streamlines the cutting and shaping of wooden members having predetermined lengths, grades, and angled edges. The system and process involves the utilization of any length of board which is finger jointed to form a continuous line of lumber. The continuous line of lumber is then cut and shaped according to preprogrammed information regarding the required length and grade of the desired wooden members as well as the required shape of the edges of the wooden members. The entire system and process is computerized to enable the steps which comprise the system and process to be in communication with one another.
The material management process of the present invention starts with the step of stocking lumber, all of equal length, by grade. The model system of the present invention may have several positions or chutes from which to begin the operation of carrying out the process of the present invention. For example, each of the chutes may be stocked with a specific width and grade of specific length wooden boards. The chutes separate the wooden boards by grade and width and it is anticipated that the length of the boards will all be the same. An operator stands at the chute area and feeds the needed grade of lumber onto a conveyor belt one board at a time. The board proceeds down the conveyor and passes through a moisture detector and a metal detector. Any board that does not pass the required specifications for moisture level and metal content is ejected off of the continuous conveyor line. If the board requires trimming for one reason or another, such as to trim a bad spot at the end of a board, the board is side ejected to a trim area. Once trimmed, the board is returned to the continuous conveyor line in linear arrangement with the other boards. The boards are then side transferred to enable them to be grooved on each of their ends for the finger joint process. After the ends of the boards are cut to form grooves, glue or some other type of adhesive is applied to one end joint on each of the boards. The boards are then side transferred back onto a continuous conveyor line which moves the boards in a linear relation to one another. The boards are then sent into a crowder which tightly shoves the ends of the boards together. The finger jointed lumber continues from the crowder into a radio frequency (RF) tunnel to allow for the drying and setting of the glue. When the lumber exits the RF tunnel, it proceeds to a proof loader which tests the reliability of the joint for strength purposes. The continuous piece of lumber is then cut to desired lengths indicated on a previously determined list. If no more cutting is required, the boards continue travel linearly on a conveyor to be packaged.
If additional cutting is required on the boards which have now been cut to a predetermined length, the boards are side transferred and accumulate in this transfer area for undergoing the next step of the process. The boards are then transferred again and run through another saw and cut, if necessary. Whether cut again or not, the boards then continue into a hopper where they are side transferred into a component saw to cut the required final lengths and angles on the boards. Once off the component saw, the lumber is stacked long to short, banded, and side transferred once again so that the banded package of lumber is transferred out of the building for staging and use.
In brief, the system of the present invention for managing building materials comprises:
means for loading a plurality of boards onto a continuous conveyor system;
means positioned along the continuous conveyor system for fingerjointing the ends of the boards to form a continuous piece of lumber;
means positioned along the continuous conveyor system for cutting the continuous piece of lumber into boards having predetermined lengths; and
means positioned along the continuous conveyor system to cut the ends of the boards to their required angles.
Further, the automated method of the present invention for managing building materials, especially in pre-cutting lumber used for building trusses and frames having predetermined specifications comprises the steps of:
preprogramming a computer system to run an automated production line for lumber;
entering required lumber specification data for end products into the computer system;
loading a plurality of boards onto a continuous conveyor belt system;
fingerjointing the ends of the boards together to form one continuous piece of lumber while the boards travel along the continuous conveyor belt system;
cutting the continuous piece of lumber into boards having predetermined lengths based on the required lumber specification data while the boards are positioned on the continuous conveyor belt system;
cutting the ends of the boards to predetermined angles based on the required lumber specification data while the boards are positioned on the continuous conveyor belt system; and
stacking, banding and transferring the cut boards to a defined location while the cut boards are positioned on the continuous conveyor belt system.
The objects and features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings wherein like numerals denote like elements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a reduced schematic of a preferred embodiment of the material management system of the present invention constructed in accordance with the present invention for carrying out the material management process.
FIG. 2 is a schematic showing the optional system component of the material management system of the present invention comprising means for treating the building material with a fire retardant.
FIG. 3 is a flowchart illustrating the material management process of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A schematic of the material management system 10 of the present invention is shown in FIG. 1. The material management system 10 of the present invention is designed to manage and process the cutting and shaping of wooden members which make up a prearranged rigid framework such as a structural truss without the need to handle several different lengths of lumber. The material management system 10 of the present invention is designed to handle lumber only by grade and width in order to reduce costs and increase efficiency of the system over that of the conventional system for cutting and shaping wooden members for the building of trusses and other building structures. Once the required length of board for starting the process is eliminated, lumber can be stored in bulk by grade and width because there is no longer a need to have access to the varying lengths of lumber. As a result, the lumber does not have to be spread out according to length and lumber yard storage room is eliminated. Eliminating the need for required lengths of lumber to start the process also enables one to purchase the required grade and width of lumber in one length, preferably the cheapest.
The material management system 10 begins with the formation of stalls or chutes which may be stocked with designated grades and widths of lumber. For example, a material management system having five stalls or chutes may store the following lumber in those stalls or chutes: 2×4-#2, 2×4-1650, 2×4-2100, 2×6-#2, and 2×6-1650. The numbers designate width and grade of lumber. The number of stalls or chutes does not change the process. A manual operator is stationed at the stalls or chutes 12. The manual operator visually checks the quality of the boards and feeds them onto a continuous conveyor line 14 one at a time in linear relationship to one another. If a board is identified as visually defective, the operator rejects the board and does not feed it onto the continuous conveyor line 14. If the board is not defective but needs trimming to eliminate a bad spot, for example on the end of the board, the operator marks the board as a board which needs to be trimmed.
The boards continue down the continuous conveyor line 14 to an automatic sensor 16 which checks the moisture content of the board and detects the presence of any staples or foreign materials in the board. If the board does not meet the specifications for moisture content, or if the board contains foreign metal objects, the board is automatically ejected from the continuous conveyor line 14.
The boards that meet specifications continue down the conveyor line 14 and those boards that were marked for trimming are side ejected to a trim area 18. The side ejection to the trim area may be performed manually by a second operator or automatically by having a sensor which detects the demarcations that were made on those boards designated for trimming. A trim saw operator will then trim the bad spots on the board and then place the board back into continuous flow on the conveyor line 14 such that the boards are still in straight linear alignment with one another.
Next, the boards are side transferred by a side transfer conveyor 20 to a first saw which has mechanisms for squaring and for serrating or cutting finger joints. After the boards are side transferred, this first saw 22 squares one end of the boards and then grooves that same end. The boards then continue to be side transferred across the side transfer conveyor 20 to a second saw 24 having mechanisms for squaring and for serrating and cutting finger joints. The second saw 24 squares and grooves the opposite ends of the boards. A glue or other adhesive is then applied to one grooved end of each of the boards by unit 26. After applying glue or adhesive to the one grooved end of each of the boards, the boards are then side transferred over to a second linear conveyor line 28 such that they are once again in a linear end-to-end relationship with one another.
A crowder 30 is positioned along this linear conveyor line 28 and the boards traveling in an end-to-end arrangement along the linear conveyor line 28 are fed into the crowder 30. The crowder 30 tightly shoves the ends of the boards together so that the grooved ends of the boards are interengaged with one another to form finger joints. The system of the present invention for managing building materials is further distinguished over those systems in the prior art by its functional capability of aligning the boards such that they are continuously flush along one side during each of the processing steps carried out throughout the system. In conventional material processing systems, boards are typically aligned along their centerline so that any deviation in width from board to board is split to both sides. In contrast, the alignment of the boards in the present system such that they are flush with one another along one side of their lengths results in any arrearage in width to occur on the inside of the truss. The side of the boards which are flush is where the drywall is applied. In order to create this type of alignment in the present systems the infeed operator crowns all of the boards all one way. As a result, the crowned boards are toward the exterior of the truss and any arrearage in width is always toward the interior of the truss. Accordingly, one side edge of the continuous piece of lumber formed by finger jointing pieces of lumber is perfectly smooth and that smooth side will comprise the outside of the truss.
After leaving the crowder 30, the lumber travels through an enclosed RF tunnel 32 where heat is applied to the lumber. The heat functions as a catalyst to start the electrolysis reaction in the glue which causes the glue to set. The continuous piece of lumber then exits the RF tunnel at the far end 34 of the RF tunnel and then enters a double bending proof loader 36 to test the reliability of the strength of the joints. In the proof loader, the continuous piece of lumber is run between rollers where the pressure of the rollers can be adjusted based on the grade of lumber. If a joint is bad, it may break. Alternatively, if a joint doesn't meet the strength requirement for its particular grade, the joint is identified by marking it with a spray paint. This process step is carried out automatically. If a joint breaks or is identified as inferior, a trim saw 38 trims that end straight and a computer signal which is generated by the use of the trim saw is sent to the infeed operator that lie is going to be short a board. The infeed operator the makes up for the missing board by infeeding another board.
Once the continuous lumber piece exits the proof loader 36, it enters an optional treatment area 40 which contains a unit that is capable of spraying the lumber with a fire retardant. The treatment area 40 will be incorporated such that the unit may be shut on or off with the flip of a switch depending upon the lumber or specific job being processed. If the unit is switched off, the continuous lumber simply passes through the treatment area 40 without any application of the fire retardant.
The continuous piece of lumber then proceeds to a flying saw 42 which cuts the boards to their exact predetermined lengths. This saw may also cut the boards to their exact lengths while angling the ends of the boards at a predetermined angle. Nevertheless, the preferred function of the flying saw is to cut the continuous piece of lumber into boards having predetermined lengths and squared off edges. The boards requiring square cut ends, which do not require further angle cuts are ejected after being cut to their predetermined lengths and travel linearly along a third continuous conveyor line 44 to the outside of the building or room which contains the system equipment where the system is carried out. These boards can then be stacked outside the building. The flying saw 42 functions by grabbing the continuous piece of lumber, cutting the lumber while traveling with the lumber, releasing the lumber, and then returning and grabbing the lumber again. Tile flying saw can be programmed to cut specific lengths of lumber at predetermined angles leaving the predetermined lengths of boards having either square cut or angle cut ends.
Boards which require further processing in the way of shorter lengths or additional angles are then side transferred on a second side transfer conveyor 46. This second side transfer conveyor 46 functions as a staging area for housing lumber so that the remaining saws do not run out of lumber to cut while the flying saw 42 stops to adjust and change length and angle measurements. The boards are then transferred once again in linear arrangement to a fourth continuous conveyor line 48. The boards then travel linearly in an end-to-end configuration to another saw, namely a cutting-in-two saw 50. Here, if needed, the boards are cut in half to arrive at shorter length boards that would have slowed the process substantially if their predetermined lengths would have been cut using the flying saw 42. If this optional length cutting step is not needed, the boards simply pass by the cutting-in-two saw 50 and are transferred linearly into a hopper 52. The boards are then side transferred along a third side transfer conveyor 54 which functions as a buffer for a component saw 56.
The boards are then kicked up on their edges and the component saw 56 makes the required angle cuts on the boards. Again, like all of the previously described saws, this component saw is programmed by a computer to make the required angle cuts.
The cut boards then proceed to a stacker 58 which stacks the boards flat and bands them together. The banded stacks are then side transferred in a linear arrangement onto a fifth continuous conveyor line 60 which carries the banded stacks to a staging area outside the building.
A continuous exhaust system is connected to all of the saws to collect and remove the sawdust which is created during the cutting steps of the process. The entire system is managed by one or more computers which communicate with one another during the course of the process steps which comprise the system in order to keep the system running effectively and efficiently without a lot of downtime. The process starts by entering a cut list into one of the computers which computes the total lineal footage that will be required for that batch of cut lumber. The infeed operator then enters the length of boards that are currently available or being used for processing. The computer then computes the number of boards of that length that should be fed into the system. The computer counts the input of the number of boards all the way down to the last one and then indicates the number of boards of a given length having a different grade that should be entered into the system next. In carrying out the system and process of the present invention, the lower grades are fed first with followed by increasing grades until the highest grade is used. The infeed operator then starts feeding boards all over again starting with the lowest grade. Starting out with the lowest grade ensures that the same grade or a higher grade will be used to produce the next board in the event of a shortage. In other words, the system is always feeding a higher grade board over the grade of board that is being cut.
Turning now to FIG. 2, a schematic showing the optional system component of the material management system of the present invention comprising means for treating the building material with a fire retardant is illustrated. A linear conveyor belt 70 having rollers 72 is used to feed the continuous board 74 that has been joined together by finger jointing individual boards. The continuous board 74 is fed, via the linear conveyor belt 70, into a treatment housing 76 which includes upper and lower fluid lines 78 having apertures 80 for releasing and spraying a fire retardant or other chemical composition onto the continuous board 74. The treatment housing 76 also comprises a control box 82 having switches which control the automatic or manual functioning of the sprayers contained in the treatment housing.
This above described means for treating the lumber with a fire retardant comprises an optional step in the system and process for managing building materials of the present invention. When the step of treating the lumber with a fire retardant is not desired, the process for this step can be eliminated by shutting down the spraying mechanism within the treatment housing 76 at the control box 82. With the spraying mechanism disabled, the continuous board 74 simply passes through the treatment housing 76 unaffected.
A flowchart illustrating the material management process of the present invention is shown in FIG. 3. In step one 90, lumber is stacked by width and grade. In that the material management process of the present invention is designed to accommodate any length of board, the boards to not have to be separated and organized by length. Product specifications regarding the required lengths and angles of the boards, as well as the total linear footage required for boards which will comprise a given truss or number of given trusses, are entered into a computer system in step two 92. The computer system controls the functioning of all of the machinery that is utilized throughout the process for managing building materials of the present invention. Once the specifications are entered into the computer, an operator feeds the required number of boards having a given width and grade onto a linear conveyor belt in step three 94. As the operator feeds the boards onto the conveyor belt, he performs a visual check of the boards and marks any boards that appear to have spots needing trimming.
Next, the boards travel along the linear conveyor belt until they reach a detector which determines the moisture content and the metal content of the boards. A further determination is made in step four 96 as to whether each of the boards meets the moisture requirement for the boards. If the moisture requirement for the board is not met, the board is rejected and side ejected off of the linear conveyor belt and out of the system in step five 98. Alternatively, if the moisture content of the board does meet the requirements, another determination is made in step six 99 to determine whether the board contains staples, nails or other metal objects. If the board contains metal objects, the board is rejected and then side ejected off of the linear conveyor belt and out of the system in step seven 100. Alternatively, if the board does not contain an inordinate number of metal objects, the board continues along the linear conveyor belt to a second operator.
The second operator views the boards as they travel along the linear conveyor belt and determines whether the boards need trimming in step eight 102. The boards may have already been marked for trimming by the first operator in which case the second operator simply pulls the designated boards and trims out the bad spots on the board in step nine 104. Once the boards are trimmed, they are returned to the linear conveyor belt. If the boards do not require any trimming, they simply continue to move along the linear conveyor belt to a side transfer area. The boards are then side transferred in step ten 106 so that they are now traveling along a conveyor belt side by side instead of end-to-end as was the case with the linear conveyor belt.
Both ends of each of the boards are then cut with grooves in step eleven 108. This is done by first passing one end of the boards past a first saw which squares off the ends of the boards and then grooves them. The boards continue to travel side by side and the opposite ends of the boards are then passed along to a second saw which squares off and then grooves these opposite ends. An adhesive is then applied to only one of the grooved ends of each of the boards in step twelve 110. Next, the boards are side transferred once again in step thirteen 112 to a linear conveyor belt where the boards once again travel in an end-to-end relationship with another. The grooved ends of the boards are then joined together in a crowder in step fourteen 114. More specifically, as the boards travel along end-to-end with only one grooved end of any two given adjacent grooved ends having adhesive, the crowder shoves the adjacent grooved ends of the boards together to form one continuous board. This process of grooving the ends of boards and then joining them together with an adhesive to form a single board is identified as finger jointing in the field of art. Nevertheless, although the process of finger jointing is contained within the process of the present invention, the process of the present invention goes way beyond finger jointing lumber in that the present invention accomplishes a way to automatically process lumber that is required for building specific trusses or housing frames, with a minimal need for manual involvement. This can drastically increase efficiency and reduces costs in the building industry.
Next, the continuous board travels through an RF tunnel in step fifteen 116 in order to dry and set the adhesive contained in the finger joints. The strength of the finger joints contained in the continuous board are then tested in a proof loader in step sixteen 118. In step seventeen 120, a determination is made as to whether any of the finger joints have broken or are weak. If a finger joint has broken, or if it is weak, the ends of the boards around the finger joint are trimmed so that they are cut square in step eighteen 122. Then, in step nineteen 124, an adjustment is made for the board shortage which has occurred by cutting and trimming the board at a weak finger joint. When the saw for trimming around the bad finger joints is used, the computer system which controls the process of the present invention detects this and enters information to the feed operator located at the start of the process to feed in an extra board. Once the ends around the bad finger joints are trimmed, the lumber continues to move along the linear conveyor belt to an optional treatment area. If the finger joints are not weak or broken, the continuous board also continues to move along on the linear conveyor belt until it reaches the optional treatment area.
In step twenty 126, the lumber is optionally treated by spraying the lumber with a fire retardant. A main on and off control switch, which can also be automated as part of the computer system, allows this step of the process to be either included or completely discluded depending upon its need. The continuous board is then cut to the required lengths and angles, which arc predetermined and have been entered into the computer system at the start of the process, in step twenty-one 128 with a flying saw. Subsequent to this cutting, a determination is made as to whether additional cutting of the boards is required in step twenty-two 130. If no additional cutting is required, the cut boards are packaged and transferred to a location outside the process in step twenty-three 132. These boards may be transferred entirely out of the building depending upon their intended use.
The boards which require more cutting are then side transferred to a buffer area in step twenty-four 134. Next, in step twenty-five 136, a determination is made as to whether the board length meets its required length. If the board length is not accurate, the board is cut to its required length in step twenty-six 138. This additional length cutting step is present in the system in order to accommodate the cutting of short length boards so that the system will not be required to slow significantly at step twenty-one 128 where the initial length cuts are made. All of the boards, whether cut or not, are then transferred to a hopper in step twenty-seven 140. The boards are then side transferred in step twenty-eight 142 to a component saw which cuts the boards to their required final lengths and angles in step twenty-nine 144.
Finally, the cut boards are stacked and banded together in step thirty 146 and the bound stacks are transferred to a desired destination in step thirty-one 148. It should also be noted that the system and method of the present invention for managing building materials allows for short gaps between product runs whose specifications are entered by batch into the over computer system. As a result, the system will accommodate the processing of boards having a different width by allowing a predetermined time gap within the system between boards having different widths that are aligned along the continuous conveyor belt system to ensure that boards of varying widths are not fingerjointed to one another to form a continuous piece of lumber having significantly varying widths.
The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. Accordingly, all suitable modifications and equivalents fall within the scope of the invention. | An automated system and process for managing building materials which requires a minimal amount of manual labor and supervision. The automated system and method are especially suited for precutting lumber used for building trusses and frames having predetermined specifications. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. Pat. application Ser. No. 08/328,527, filed Oct. 25, 1994 and now U.S. Pat. No. 5,452,542.
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to the field of gates and, more particularly, to an automated security barrier apparatus suitable for use in residential, farm and industrial settings.
2. Background of the Related Art
Automated apparatuses for opening and closing gates have had a long history of development. Such apparatuses have been developed to secure against entry into areas, and to allow individuals to enter such areas without having to exit from their vehicles. The known apparatuses include, for example, powered gates having laterally sliding metal gates, folding metal doors, and bars that are raised and lowered.
Chains have also been used as an entry barrier in security gate apparatuses. The known apparatuses include link chains anchored on one side of a drive leading to a secured area and locked on the opposite side of the drive. These apparatuses require individuals to leave their vehicles, lower the chain, drive through, and then stop and reattach and lock the chain. Such apparatuses are inadequate due to the time required to perform these manual steps, especially in bad weather and in poorly lighted areas were personal safety is a concern.
Entry barrier apparatuses utilizing a chain are disclosed in U.S. Pat. No. 353,368 to Miller, U.S. Pat. No. 484,572 to Rudert and U.S. Pat. No. 4,333,268 to Dumbeck. The disclosed apparatuses include moving components which are installed underground. Consequently, the components are exposed to water and to sleet and ice in colder environments, causing accelerated wear of the apparatuses.
Other entry barrier apparatuses utilizing a chain and including above-ground components are disclosed in U.S. Pat. No. 2,663,103 to Ellison and U.S. Pat. No. 4,553,739 to Baines.
A cable gate apparatus is disclosed in U.S. Pat. No. 5,245,787 to Swenson et al., which includes a slide member mounted in a track to raise a lift arm and gate cable to a raised position.
In view of the above-described inadequacies of the known security barriers, there has been a need for a chain-type security barrier apparatus which is remotely actuated by persons without having to leave the safety and comfort of their vehicles, durable, weather resistant, simple in construction and easy to install.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above-described inadequacies of the known security barrier apparatuses and has as an object to provide a chain-type security barrier apparatus can be remotely actuated.
Another object of the present invention is to provide a security barrier apparatus which is weather resistant.
A further object of the invention is to provide a security barrier apparatus which is durable, simple in construction and easy to install.
A still further object of the invention is to provide a security barrier apparatus having protective features to prevent the apparatus being damaged by a vehicle colliding with the chain.
To achieve the foregoing objects and advantages of the invention, as embodied and broadly described herein, the security barrier apparatus in accordance with a preferred embodiment of the invention is suitable for use with spaced first and second supports which protrude upwardly from a surface. The apparatus is adapted to be mounted to one of the supports. The apparatus comprises a reversible motor, a reel which is connected to and rotatably driven by the motor, and a chain secured to the reel. The chain is wound and unwound on the reel by operation of the motor in respective winding and unwinding directions.
The chain is adapted to extend from the first support to the second support. The chain is raised above the surface by operation of the motor in the winding direction, and is lowered onto the surface by operation of the motor in the unwinding direction.
The apparatus preferably further comprises a brake means for engaging the chain. The brake means defines an opening and the chain is movable through the opening when the brake means is in a non-braking condition and the motor is operating.
The apparatus may further comprise a limiting means for limiting the length of chain which may be protracted when the brake means is in the non-braking condition, and a housing to surround the moving components and protect them from the weather.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view illustrating a security barrier apparatus in accordance with a preferred embodiment of the invention, with the barrier in a raised position;
FIG. 2 is a side elevational view illustrating the barrier of the apparatus of FIG. 1 in a lowered position;
FIG. 3 is a front elevational view of the security barrier apparatus in the direction of line 3--3 of FIG. 2;
FIG. 4 is a side elevational view of a portion of the chain brake mechanism of the security barrier apparatus in a non-braking condition;
FIG. 5 is a top plan view in the direction of line 5--5 of FIG. 4, showing the sliding plate of the chain brake in a retracted position;
FIG. 6 is a side elevational view of a portion of the chain brake of the security barrier apparatus in a braking condition in which the chain is engaged by the sliding plate;
FIG. 7 is a top plan view in the direction of line 7--7 of FIG. 6, showing the sliding plate in a chain-engaging position;
FIG. 8 is an exploded side view illustrating the fixed plates and sliding plate of the chain brake;
FIG. 9 is an exploded front view in the direction of line 9--9 of FIG. 8;
FIG. 10 is an illustrational view of a security barrier apparatus in accordance with another preferred embodiment of the invention, with the barrier in a raised position;
FIG. 11 is an illustrational view of a security barrier apparatus in accordance with a further preferred embodiment of the invention, with the barrier in a raised position;
FIG. 12 is a partial side elevational view of the security barrier apparatus of FIG. 10;
FIG. 13 is a partial front elevational view of the security barrier apparatus of FIG. 10;
FIG. 14 is a top plan view in the direction of line 14--14 of FIG. 13; and
FIG. 15 is a partial cross-sectional view in the direction of line 15--15 of FIG. 10.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the invention will now be described with reference to the drawing figures. In the drawings, common elements are identified by common reference numbers.
FIG. 1 illustrates a security barrier apparatus 20 in accordance with a preferred embodiment of the invention, as used in combination with a pair of spaced support posts 10, 11. The posts are partially embedded in the ground on opposite sides of a drive 15 which leads to a secured area. The apparatus may be mounted to any type of post, pole or fence, or to trees and other supports.
The apparatus 20 comprises a chain 21 which extends between the posts 10, 11 and, in the illustrated raised position, forms a barrier to vehicles. The chain is shown secured to a bracket 12 by a fastener 13. The chain may be locked to the post 10 to prevent it from being disconnected.
The apparatus 20 further comprises a housing 30 which is mounted to the post 11 and surrounds the moving components of the apparatus. As shown in FIG. 1, the housing includes a back wall 31, opposed side walls 32 (only one sidewall is shown), and a top wall 33. The top wall 33 is secured to the upper end of the post 11, and the back wall 31 is secured to a lower portion of the post by a rod 34 or the like, which in turn is fastened to the post. The rod is preferably secured to the housing by a lock 35 to prevent the housing from being separated from the post. The housing is open at the bottom and includes a front wall (not shown) which is removable from the remainder of the housing to access the enclosed components. The front wall defines an opening (not shown) through which the chain extends.
The housing 30 protects the enclosed components of the security barrier apparatus from being exposed to rain and other forms of precipitation which accelerate wear. The housing is preferably formed of a lightweight, weather resistant material such as fiberglass or the like, to enable the housing to be easily removed from the post 11 for repair purposes. The housing may optionally be formed of a more rigid material such as a metal. In addition to protecting the enclosed components, the housing improves the appearance of the apparatus.
The apparatus 20 further comprises a motor 40 which is mounted to the post 11 near its upper end. The motor is reversible and preferably electrically powered. The motor may optionally be powered by a battery or a solar energy device (not shown). The motor is preferably actuated by an electronic transmitter carried in a vehicle. In this manner, when the chain 21 is raised, only persons having such a transmitter may operate the motor to lower the chain. Referring to FIG. 1, the motor may optionally be actuated by an electronic keypad 100 mounted, for example, to the housing 30, to enable those individuals not having a transmitter, but having knowledge of the operating code, to lower the chain.
As illustrated in FIG. 3, the motor 40 includes a drive shaft 41 and a drive sprocket 42 mounted on the drive shaft.
A winch-type reel 50 is mounted to the post 11 above the motor 40. The reel includes a reel sprocket 51 mounted on a reel shaft 52. A connecting chain 53 connects the drive sprocket 42 of the motor to the reel sprocket. The reel shaft and reel sprocket are held in position by spaced pillow blocks 54 secured to the post by fasteners 55.
A cable 60 is attached at one end to the reel shaft 52 and is connected at its opposite end at 23 to the chain 21. The cable is wound and unwound by reverse operation of the motor, to cause the chain to be retracted and protracted, respectively, from within the housing. As shown in FIG. 1, the cable extends downward from the reel close to the post 11 to prevent interference with the chain.
The reel 50 enables the cable 60 to be used to move the chain 21. Because the cable is relatively small in diameter, the reel is also small in diameter. The small diameter of the reel shaft creates a high amount of leverage and decreases the stress on the motor when a heavy chain is being wound.
The length of the chain 21 is selected so that in the raised position shown in FIG. 1, the chain extends downward from the cable 60 and around a lower pulley 65 mounted to the post 11 by a bracket 66, upward around an upper pulley 67 mounted to the post 11 above the lower pulley by a bracket 68, and across the drive 15 to the post 10.
Referring to FIG. 3, the chain 21 preferably includes a frangible link 22 located near the connection 23 between the cable 60 and the chain. The frangible link has a small section removed so that it opens and releases the major portion of the chain from the cable when subjected to a predetermined stress. The link prevents any potentially damaging stress being transmitted through the chain and to the drive shaft 41 and drive sprocket 42 of the motor 40. The tension of the chain looping around the lower pulley 65, the upper pulley 67 and the reel 50, is sufficient to enable the frangible link to open when subjected to the predetermined stress. The predetermined stress is below a stress level which may damage the reel or the motor.
The posts 10, 11 are preferably anchored in cement (not shown) to support the extended chain and remain upstanding if a vehicle collides with the apparatus.
The apparatus further comprises means for limiting the length of chain which may be protracted from the apparatus. The limiting means preferably comprises a circular-shaped stop 24 disposed on the chain near the connection 23. As illustrated in FIG. 2, when the chain is lowered, the stop 24 is positioned near the lower surface of a brake means 70 for engaging the chain. If a vehicle or other object engages the chain when the brake means is in a non-braking condition, the stop is raised until it abuts the lower surface of the brake means and prevents additional chain from being protracted. Consequently, if the chain is subjected to a stress higher than the predetermined strength of the frangible link 22, the frangible link fails and releases the chain to prevent transmission of the stress to the reel 50 and motor 40.
The stop may optionally be an enlarged chain link (not shown) provided in the chain, and of a size so as to be unable to pass upward through the brake means.
As illustrated in FIG. 4, the brake means 70 preferably comprises a solenoid-controlled chain brake mechanism. The chain brake includes an upper fixed plate 71 and a lower fixed plate 72. With reference to FIG. 9, the lower fixed plate 72 has a U-shaped cross-section and includes upward extending sidewalls 73 which are attached to the upper fixed plate 71. The fixed plates are secured to the bracket 68. As shown in FIG. 3, the bracket 68 is fastened to the post 11.
Referring to FIG. 4, a sliding plate 74 is disposed between the fixed plates. Lubricating plates 75, 76 composed of a lubricating material such as TEFLON™ are placed between the fixed plates 71, 72 and the sliding plate to enable the sliding plate to slide with reduced friction.
The fixed plates 71, 72 define aligned, preferably circular shaped openings 77, 78, respectively. Referring to FIG. 5, the sliding plate 74 defines an opening having a circular portion 79 and an elongated portion 80 in communication with the circular portion. The lubricating plates 75, 76 also include circular shaped openings 81, 82, respectively (FIG. 4), which are aligned with the circular openings in the fixed plates. The circular openings of the fixed plates and the lubricating plates, and the circular portion of the opening of the sliding plate, are of approximately the same diameter, which is selected to allow the chain to pass through the plates. The circular opening of at least the lower fixed plate 72 is smaller than the diameter of the stop 24 to limit the upward movement of the stop and, thus, also the chain 21. At its uppermost position, the stop abuts the bottom face of the lower fixed plate 72 and prevents further upward movement of the chain.
With further reference to FIG. 4, the chain brake 70 comprises a solenoid 90 which is mounted on a bracket 91 secured to the lower fixed plate 72. The solenoid includes a retractable shaft 92 which is attached at its tip 93 to the sliding plate 74. A first, fixed vertical plate 94 is disposed on the shaft. A second, fixed vertical plate 95 is mounted to the bracket 91 and defines an opening 96 through which the shaft 92 reciprocates when the solenoid is actuated and deactivated. A coil spring 97 is positioned on the shaft between the plates 94, 95.
As illustrated in FIG. 4, when the solenoid 90 is actuated, the shaft 92 and sliding plate 74 are pulled away from the fixed plates 71, 72, and the spring 97 is compressed between the vertical plates 94, 95. When the shaft is fully retracted as shown, the circular portion 79 of the opening of the sliding plate is aligned with the openings 77, 78 in the fixed plates 71, 72, respectively, and the openings 81, 82 in the lubricating plates 75, 76, respectively. As shown in FIG. 5, the chain is able to move upward and downward through the chain brake.
Referring to FIG. 6, when the motor 40 and solenoid 90 are deactivated, the spring 97 expands and pushes the shaft 92 and sliding plate 74 toward the fixed plates 71, 72. When the shaft is fully protracted as illustrated, the circular portion 79 of the opening of the sliding plate is out of alignment with the openings 77, 78 in the fixed plates and the openings 81, 82 in the lubricating plates. Referring to FIG. 7, the elongated portion 80 of the opening of the sliding plate engages the chain 21 and prevents movement of the chain relative to the chain brake. The forward movement of the shaft 92 is limited by the vertical plate 95.
When an individual in a vehicle reaches the security chain barrier, the chain 21 is lowered as illustrated in FIG. 2 to allow the vehicle to drive over it. To lower the chain, the motor 40 is actuated by an electronic transmitter located in the vehicle to cause the reel 50 to unwind the cable. The solenoid 90 is actuated simultaneously with the motor and remains in the non-braking condition shown in FIG. 4 until the motor is deactivated when the chain is fully lowered. The chain links pass through the plates until the chain reaches its lowered position.
Once the chain 21 is fully lowered, the motor 40 and solenoid 90 are simultaneously deactivated by a preset travel limit switch located within the motor. The compressed spring 97 expands and pushes the retractable shaft 92 and sliding plate 74 toward the fixed plates and into the position shown in FIG. 6. In this position of the sliding plate, any large stress exerted on the chain causes the frangible link to open and release the chain.
The apparatus is designed to allow a sufficient length of chain to be protracted so that when the chain is lowered as illustrated in FIG. 2, it rests on a substantial portion of the width of the drive 15 between the posts 10, 11. This allows wide vehicles to drive over the chain without running into the downward extending portions of the lowered chain and possibly causing the frangible link 22 to release the chain.
Once the vehicle drives over the chain, the chain 21 is lifted to the raised position illustrated in FIG. 1. To raise the chain, the motor 40 and solenoid 90 are again actuated to wind the cable on the reel 50 and lift the chain.
Once the chain 21 is raised, the motor 40 and solenoid 90 are deactivated. The sliding plate 74 engages the chain and prevents its further movement. If a vehicle drives into the chain, the frangible link 22 may release the chain and prevent damage to the cable 60, reel 50 and drive shaft 41.
Referring to FIG. 3, stress on the motor 40 and drive shaft 41 are limited by the location, orientation and diameter of the reel 50. The reel shaft 52 is approximately perpendicular to the drive sprocket 42 of the motor. Any external downward force transmitted to the reel through the chain 21 and cable 60 is absorbed by the reel and the pillow blocks 54 and does not damage the drive shaft of the motor.
Another preferred embodiment of the invention is illustrated in FIGS. 10 and 12-15. The security barrier apparatus 20' does not include a cable to move the chain 21, and the chain is wound directly onto a reel 98 by operation of a reversible motor 100. The reel and motor are mounted to a bracket 102 which is fastened to the post 11. The bracket defines vertically extending slots 103, and fasteners 104 extend through the slots and into the post.
As shown in FIGS. 12 and 13, the reel 98 is comprised of a spool 106, side plates 108 and a shaft 110 having a sprocket 112 provided on one end. A link chain 114 connects the sprocket to a sprocket 116 provided on the drive shaft 118 of the motor 100. Operation of the motor causes the chain to be either wound onto or unwound from the reel.
The apparatus comprises a pulley 67 and a chain brake 90 fastened to a bracket 68 which is mounted to the post 11 above the reel 98. The pulley and chain brake are preferably of the same structure as in the embodiment of FIGS. 1-9.
A means for guiding the chain 21, preferably a pair of horizontally aligned pulleys 120, is fastened to the bracket 102 between the chain brake 70 and the reel 98. The pulleys 120 define a space 121 therebetween through which the chain passes as it is wound onto the reel. The space is in vertical alignment with the openings in the plates of the chain brake. The large end portions 122 of each pulley are spaced an effective distance from each other to prevent lateral shifting of the chain and maintain the alignment of the chain with the openings in the chain brake. As the chain is wound onto the reel, the effective diameter of the spool increases. The pulleys 120 compensate for this increase in diameter and consequently prevent chain drag, stress on the motor and noisy operation of the apparatus.
In some instances, when the chain 21 is in a retracted or extended position, chain links positioned inside the chain brake may not fully engage in the elongated portion 80 of the sliding plate 74 (FIG. 14). If an object or vehicle collides with the chain, the chain link must move upward until the chain is captured by the sliding plate.
To enable the chain link to move upward until it is captured by the elongated portion 80 of the sliding plate 74 and consequently to prevent the force of the collision being transmitted through the chain to the drive shaft 118 of the motor 100, the slots 103 formed in the bracket 102 allow the attached reel 98 and motor 100, to move vertically until the chain is captured.
A weight 124 is preferably provided on the chain 21 to urge the chain downward toward the post 10 when it is being unwound from the reel and lowered to the fully protracted position shown in FIG. 2. As best shown in FIG. 15, the weight is cylindrical shaped and maintained at a fixed location on the chain by a fastener 125 which extends through the frangible link 22.
Referring to FIGS. 12 and 13, the motor 100 may be electrically connected to an electrical outlet 126 provided on the post 11.
A further preferred embodiment of the invention is illustrated in FIG. 11. The security barrier apparatus 20" comprises a pulley 67 mounted to a bracket 68, and a reel 98 and motor 100 mounted on a bracket 102 positioned below the pulley 67. The bracket 102 defines vertical slots 103 to enable the bracket to move upward in the event the chain 21 becomes entangled on the pulley 67, so as to prevent excessive stress being conveyed to the motor.
In contrast to the embodiments of the invention shown in FIGS. 1-9 and 10 and 12-15, respectively, the illustrated security barrier apparatus does not include a chain brake. The chain 21 includes a frangible link 22 located inside the weight 124 intermediate the posts 10 and 11. The frangible link opens to disconnect the two chain portions from each other when subjected to a predetermined stress. The predetermined stress is selected so that the frangible link fails before any potentially damaging stress is transmitted to the motor.
The foregoing description of the preferred embodiment of the invention has been presented to illustrate the principles of the invention and not to limit the invention to the particular embodiment illustrated. It is intended that the scope of the invention be defined by all of the embodiments encompassed by the following claims, and their equivalents. | A security barrier apparatus suitable for use in residential, farm and industrial settings includes a motor, a chain and a brake mechanism for engaging the chain. The apparatus is mounted to a first support such as a post. The chain extends from the first support to a second spaced support and is raised and lowered relative to the ground by operation of the motor. The motor may be remotely actuated by an electronic transmitter. The apparatus further includes protective features to prevent damage to the motor in the event that a vehicle collides with the chain. | 4 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a torque limiter for use in office appliances and the like. More particularly, the present invention relates to a torque limiter which generates a torque stably without little fluctuation and lengthens the life of a bearing without being affected adversely by an environment having a high temperature and a high humidity in which it is difficult to lubricating the torque limiter.
[0002] The torque limiter is classified into two types. In one type, a binding force is applied to an inner ring in a radial direction to generate a torque. In the other type, a spring is used to slidably contact one friction plate with other friction plate, with the one friction plate being pressed against the other friction plate in a thrust direction to generate a torque. In both types, the torque is generated by a frictional force. Many prior arts of the torque limiter are known (for example, Japanese Patent Application Laid-Open Nos. 8-270675, and 7-301248, 6-235447 and Japanese Utility Model Laid-Open No.5-8062).
[0003] Lubricating oil or lubricating grease is used to prevent a wear from occurring between the inner ring of the torque limiter and the spring thereof or the friction plate and between the friction plates, an abnormal heat generation, and an abnormal sound generated by seizure. The inner ring of the torque limiter is made of sintered metal and impregnated with the lubricating oil to use the inner ring as a lubricating mechanism.
[0004] The lubricating oil and the lubricating grease for use in the torque limiter frequently contain mineral oil, an aromatic compound and ester as the base oil thereof and additives such as a wear-resistant agent added to the base oil in dependence on use. The torque limiter is required to have the performance of retaining and maintaining an oil film for a long time by preventing contact between metals and stabilizing friction coefficients thereof. In the torque limiter for use in a paper transport apparatus of a copying machine, a printer, and the like and a mechanism for tensioning a ribbon or a sheet, there is a demand for the development for a lubricating agent allowing a torque to fluctuate little and preventing sounds from being generated by contact between the metals.
[0005] There is a demand that office appliances such as the copying apparatus using the torque limiter can be reliably used in different environments. There is also a demand for the development of lubricating oil allowing the torque to fluctuate little and preventing sounds from being generated by the contact between the metals in an environment having a high temperature and a high humidity (for example, 40° C. and relative humidity (RH) in the neighborhood of 90%) environment where it is difficult to form an oil film.
[0006] Resin such as polycarbonate resin or ABS resin having a high processability is used for parts on the periphery of the torque limiter. Thus the parts made of the resin are cracked, broken or the surfaces thereof may become rough, i.e., a so-called chemical attacking phenomenon may occur owing to contact between the parts made of the resin and lubricating oil, for use in the torque limiter, which has leaked from the torque limiter or between the parts made of the resin and the vapor of the lubricating oil. For example, the lubricating oil using ester or an aromatic compound as its base oil has a high oil film-forming performance and satisfies the torque performance necessary for the torque limiter to perform. But the lubricating oil containing the base oil, whose molecules have aromatic rings and polar groups, as its main component is liable to chemically attack the parts made of the resin. The ester-containing base oil is apt to be hydrolyzed in an environment having a high temperature and a high humidity.
[0007] To prevent the lubricating oil from chemically attacking the members made of resin, conventionally known is a rust-proof oil containing the rust-proof agent and the antioxidant both added to the base oil, as disclosed in Japanese Patent Application Laid-Open No.2002-348688. The base oil contains polyolefin oil. The rust-proof agent is at least one kind of metallic salt selected from among metallic salts of sulfonic acid and metallic salts of monocarboxylic acid. The antioxidant is a phenolic antioxidant.
[0008] As the lubricating oil or the lubricating grease, for the torque limiter, which generates a torque which fluctuate little and allows the torque limiter to have a long life by preventing contacts of metals which occur owing to breakage of an oil film and which does not chemically attack resin, the lubricating oil impregnating a bearing therewith or the lubricating grease disclosed in Japanese Patent Application Laid-Open No.2002-249794 contains the base oil consisting of the compound of synthetic saturated hydrocarbon and at least one kind of phosphate ester selected from among aliphatic phosphate and aliphatic phosphite. The phosphate ester is contained at 1 to 8 wt % for the total weight of the lubricating oil.
[0009] Utilizing a torque generated by the torque limiter, the torque limiter is used as a part of a paper supply mechanism of a copying apparatus and a printer. In an environment having a high temperature and a high humidity, the viscosity of the lubricating oil lowers, the thickness of an oil film on members of the torque limiter decreases, and water in the air penetrates into the lubricating oil in the form of droplets and into the lubricating surface. Thereby the oil film is broken in a short period of time, thus causing the torque limiter to chatter (abnormal torque) and thus the paper supply function to deteriorate. The torque limiter is liable to chatter in an environment having a high humidity in the neighborhood of the dew point temperature.
SUMMARY OF THE INVENTION
[0010] It is an object of the present invention to provide a torque limiter, for use in office appliances, which generates a torque fluctuating little in an environment having a high temperature and a high humidity, allows a bearing to have a long life by preventing contacts of metals which occur owing to breakage of an oil film, and does not chemically attack members made of resin.
[0011] The torque limiter of claim 1 of the present invention includes an inner ring fitted inside an outer member and a torque transmission member interposed between the inner ring and the outer member. A predetermined torque is generated by a friction generated between the inner ring and the torque transmission member, when the inner ring and the outer member rotate relatively to each other. The members are impregnated with lubricating oil to slide the members on each other. The lubricating oil contains a base oil consisting of synthetic saturated hydrocarbon oil having a kinematic viscosity of 500 to 1200 mm 2 /s at 40° C. and an emulsifier added to the base oil.
[0012] The torque limiter of claim 2 of the present invention includes an inner ring fitted inside an outer member and a torque transmission member interposed between the inner ring and the outer member. A predetermined torque is generated by a friction generated between the inner ring and the torque transmission member, when the inner ring and the outer member rotate relatively to each other. The members are impregnated with lubricating grease to slide the members on each other. The lubricating grease contains a base oil consisting of synthetic saturated hydrocarbon oil having a kinematic viscosity of 500 to 1200 mm 2 /s at 40° C. and an emulsifier and a thickener both added to the base oil.
[0013] The emulsifier contained in the lubricating oil or the lubricating grease for use in the torque limiter of the present invention is a metallic salt of sulfonic acid. The emulsifier is added to the base oil of the lubricating oil or the lubricating grease as a solution dissolved in a solvent not generating a chemical attacking property.
[0014] In the torque limiter of the present invention, as the lubricating oil or the lubricating grease impregnating the torque limiter therewith, the synthetic saturated hydrocarbon oil having a kinematic viscosity of 500 to 1200 mm 2 /s at 40° C. is used as the base oil of the lubricating oil or the lubricating grease, and the metallic salt of the sulfonic acid is used as the emulsifier. Therefore droplets that penetrate into the lubricating agent are formed into very fine droplets with the emulsifier. Further owing to a high viscosity of the base oil, the oil film can be prevented from being broken. Furthermore since the lubricating oil or the lubricating grease contains the synthetic saturated hydrocarbon oil and the metallic salt of sulfonic acid as its main component, it is possible to use a small amount of additives containing polar components for the lubricating oil or the lubricating grease. Thereby the lubricating oil or the lubricating grease is excellent because it does not chemically attack resin materials. Therefore the torque limiter generates a torque that fluctuates little, i.e., provides a stable torque in the environment having a high temperature and a high humidity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a sectional view showing an example of a torque limiter.
[0016] FIG. 2 is a sectional view showing another example of the torque limiter.
[0017] FIG. 3 is a sectional view showing another example of the torque limiter.
[0018] FIG. 4 is a sectional view showing another example of the torque limiter.
[0019] FIG. 5 is an illustration for explaining the stability of a torque.
[0020] FIG. 6 is an illustration showing an apparatus for examining a bending test.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] The base oil which can be used for the lubricating oil of the present invention or the lubricating grease thereof is synthetic saturated hydrocarbon oil. Of the synthetic saturated hydrocarbon oil, oligomers of α-olefin are preferable. For example, polymers or copolymers of the α-olefin, having 3 to 20 carbon atoms, such as butane-1, isobutylene-1, α-octane, and decane-1 can be preferably used. These oligomers are liquid at the normal temperature. As the copolymers of the α-olefin, copolymers of ethylene and α-olefin can be preferably used.
[0022] As the preferable base oil, it is possible to use poly-α-olefin shown by a chemical formula 1 shown below and a hydrogenated ethylene-α-olefin copolymer shown by a chemical formula 2. As the poly-α-olefin, hydrogenated oligomers of the α-olefin having 6 to 18 carbon atoms is preferably used. As the ethylene-α-olefin copolymer, hydrogenated copolymers of ethylene and the α-olefin having 3 to 10 carbon-atoms is preferably used.
where n is integers 4 through 16, and m is integers 1 through 6.
where n is integers 1 through 8, m is integers 1 through 3, q is integers 1 through 3, and p is integers different according to the viscosity of polyolefin oil.
[0023] To allow the torque limiter to generate a stable torque with fine droplets emulsified in the lubricating oil or in the lubricating grease in a high-humidity environment in which dew condenses, the kinematic viscosity of the polyolefin oil used as the base oil at 40° C. is 500 to 1200 mm 2 /s and favorably 700 to 900 mm 2 /s. If the kinematic viscosity of the polyolefin oil is below 500 mm 2 /s, an oil film is liable to be broken in a high-temperature and high-humidity environment in which fine droplets are emulsified. If the kinematic viscosity exceeds 1200 mm 2 /s, an initial decrease amount of the torque becomes large.
[0024] As the above-described base oil, the poly-α-olefin can be preferably used. A mixture of two or more poly-α-olefins having different viscosities can be used to allow the base oil to have a predetermined viscosity. But it is preferable to use the poly-α-olefin singly.
[0025] Because the above-described base oil has a high viscosity, it has a high oil film-forming performance. Therefore the above-described base oil has a high effect of restraining the torque limiter from chattering and a bearing from being worn, thereby lengthening the life of the bearing. The base oil is excellent in chemical non-attacking property. More specifically, when the composition of the lubricating oil leaks to the outside of the torque limiter for some reason or contacts members made of synthetic resin disposed on the periphery thereof, the composition of the lubricating oil does not chemically attack them.
[0026] In the present invention, it is possible to use an emulsifier capable of emulsifying fine droplets mixed with the synthetic saturated hydrocarbon oil in an environment having a high humidity in which dew condensates. As a preferable emulsifier, it is possible to use a metallic salts of sulfonic acid shown by a chemical formula 3 shown below.
(RSO 3 )nM Chemical formula 3
[0027] In the chemical formula 3, reference symbol R denotes an alkyl group, an alkenyl group, and alkyl benzene; and reference symbol M denotes metal. The alkali earth metal or the alkali metal is preferable as the metal. More specifically, it is possible to exemplify calcium, barium, magnesium, and potassium. Reference symbol n denotes 1 or 2. In the present invention, it is possible to use two or more metallic salts of sulfonic acid in combination.
[0028] The emulsifier is demanded to have the effect of preventing the breakage of the oil film by promptly emulsifying water which has penetrated into the lubricating agent. To comply with the demand, the molecule of the emulsifier is required to have a structure having a hydrophobic group having a proper molar amount and a hydrophilic group having a high polarity. When water is present in the lubricating agent having a low viscosity, it has a low oil film-forming performance. Therefore the oil film is broken by the influence of the emulsified water. However, when water is present in the lubricating agent having a high viscosity, it has a high oil film-forming performance. Therefore the oil film is little influenced by the emulsified water, and thus the breakage of the oil film hardly occurs.
[0029] As the addition amount of the metallic salt of sulfonic acid serving as the emulsifier, it is favorable to add 0.5 to 12 wt % thereof to the total weight of the base oil. If the addition amount of the metallic salt of sulfonic acid is less than 0.5 wt %, it does not have emulsifiable effect. On the other hand, if the addition amount thereof is more than 12 wt %, the metallic salt of sulfonic acid adversely affects the solubility thereof for the base oil, the stability of the torque, and the property of the chemical non-attacking property of the lubricating oil or the lubricating grease. Considering the performance of the torque limiter and the property of the chemical non-attacking property of the lubricating oil or the lubricating grease in the environment having a high humidity, it is more favorable to add 1 to 8 wt % of the metallic salt of sulfonic acid to the base oil.
[0030] It is preferable that the metallic salt of sulfonic acid is dissolved in a solvent excellent in the chemical non-attacking property which will be described later to allow the metallic salt of sulfonic acid to be compatible with other oils and additives and accelerate emulsification. As solvents excellent in the chemical non-attacking property, non-polarized solvents are preferable. For example, it is possible to use mineral oil or synthetic saturated hydrocarbon oil.
[0031] The metallic salt of sulfonic acid is dissolved at 20 to 80 wt % and favorably 30 to 70 wt % in a solution of the mineral oil or in a solution of the synthetic saturated hydrocarbon oil. Therefore the addition amount of the solution of the metallic salt of sulfonic acid and the mineral oil or the like is 2.5 to 15 wt % for the total weight of the base oil.
[0032] In the present invention, a thickener is added to the lubricating oil essentially containing the base oil and the metallic salt of sulfonic acid serving as the emulsifier to use the lubricating oil as a lubricating grease.
[0033] The thickener added to the lubricating oil disperses semi-solidly in the base oil and takes a micellar structure. As the thickener, the following substances can be used: metal soaps such as sodium soap, lithium soap, calcium soap, barium soap, calcium complex soap, aluminum complex soap, lithium complex soap, barium complex soap; inorganic substances such as Penton, silica aerogel, sodium terephthalate, urea, polytetrafluoroethylene, hidroxyapatite, polyethylene powder; and non-soaps such as urea compounds, waxes, and the like. It is preferable to use urea compounds and lithium soaps having performance balanced among mechanical stability, resistance to heat, and resistance to water as the thickener.
[0034] Phosphate ester can be contained in the lubricating oil or the lubricating grease of the present invention as a wear-resistant agent.
[0035] As the phosphate ester, a substance shown by a chemical formula 4 shown below is used.
(RO) 3 P═O Chemical formula 4
[0036] In the chemical formula 4, reference symbol R denotes an alkyl group, an alkenyl group or aryl group.
[0037] The phosphate ester serving as the wear-resistant agent is contained in the lubricating oil at 1 to 8 wt % for the total weight of the lubricating oil. When the addition amount of the phosphate ester is less than 1 wt %, the phosphate ester does not have an effect of decreasing wear and improving the stability of the torque. On the other hand, if the addition amount thereof is more than 8 wt %, the phosphate ester gives a bad influence on the chemical non-attacking property of the lubricating oil. Considering the performance of the torque limiter and the chemical non-attacking property of the lubricating oil, it is more favorable to use 3 to 5 wt % of the phosphate ester for the total weight of the lubricating oil.
[0038] An example of the torque limiter of the present invention for which the above-described lubricating oil or the lubricating grease is used will be described below. The lubricating oil or the lubricating grease is used to prevent a wear from occurring between an inner ring of the torque limiter and a spring thereof or a friction plate thereof, between the friction plates, an abnormal heat generation, and an abnormal sound caused by seizure.
[0039] A torque limiter shown in FIG. 1 is of a friction type generating a torque by a binding force applied to an inner ring 1 made of metal by a coil spring 2 having a large-diameter portion and a small-diameter portion. The coil spring 2 is provided on the outer side of the inner ring 1 . The coil spring 2 is locked to a cover 3 and a hood 4 through hooks 2 a and 2 b . By rotating the cover 3 inserted into the hood 4 by press fit, the binding force applied to the inner ring by the coil spring 2 changes successively. Thereby the torque can be freely adjusted. The rotational direction of the inner ring 1 is limited to one direction in dependence on a winding direction of the coil spring 2 .
[0040] In a torque limiter shown in FIG. 2 , a cylindrical coil spring 2 is provided on the outer side of an inner ring 1 made of metal. The coil spring 2 is locked to a hood 4 through a hook 2 b of the coil spring 2 . Because the coil spring 2 is cylindrical, it is incapable of adjusting the torque. But by using the coil springs 2 having different interferences for the inner ring in combination, the binding force applied to the inner ring 1 by the coil spring 2 changes, and the value of the torque is determined. In this manner, the torque can be adjusted. In the torque limiter having the above-described configuration, the rotational direction of the inner ring 1 is limited to one direction in dependence on a winding direction of the coil spring 2 .
[0041] In a torque limiter shown in FIG. 3 , as in the case of the torque limiter shown in FIG. 2 , a cylindrical coil spring 2 is provided on the outer side of a separate-type inner ring 1 made of metal. Because the coil spring 2 is cylindrical, it is incapable of adjusting the torque. But in dependence on the interference of the coil spring 2 for the inner ring 1 , the value of the torque is determined. In the torque limiter having the above-described configuration, the rotational direction of the inner ring 1 is limited to one direction in dependence on a winding direction of the coil spring 2 .
[0042] In a torque limiter shown in FIG. 4 , a friction plate 5 is pressed against an inner ring 1 made of metal by a spring 2 . A torque is generated by a frictional force acting between the inner ring 1 and the friction plate 5 . Because the frictional force can be changed in dependence on a pressing force, the torque can be adjusted. In the torque limiter having the above-described configuration, the rotational direction of the inner ring 1 does not depend on the winding direction of the coil spring 2 .
[0043] The lubricating oil and the lubricating grease for use in the torque limiter of the present invention are described below. The components used in the examples and the comparison examples are abbreviated as shown below. Mixing ratios of the components are shown by wt %. The components EM1 through EM3 were used as solutions.
[0044] PAO1: poly-α-olefin oil (kinematic viscosity at 40° C.: 200 mm 2 /s)
PAO2: poly-α-olefin oil (kinematic viscosity at 40° C.: 900 mm 2 /s) TCP: tricresyl phosphate EM1: emulsifier 1 consisting of metallic salt of sulfonic acid (Through-hole CA-45N contained at 45 wt % as metallic salt of sulfonic acid) EM2: emulsifier 2 consisting of metallic salt of sulfonic acid (Through-hole BA-30N contained at 31 wt % as metallic salt of sulfonic acid) EM3: emulsifier 3 consisting of metallic salt of sulfonic acid (Through-hole 400 contained at 62 wt % as metallic salt of sulfonic acid)
[0050] The components were mixed at the ratios shown in tables 1 and 2 to manufacture the lubricating composition of each of the examples and the comparison examples. Table 1 shows examples of oily lubricating oils. Table 2 shows examples of lubricating greases containing lithium soap (20 wt % is used for total weight of grease) used as the thickener. Reference symbol “Bal” shown in tables 1 and 2 indicates a remaining amount (wt %) other than the addition of numerical values (wt %) of components.
TABLE 1 Base oil Emulsifier PAO 1 PAO 2 EM 1 EM 2 EM 3 TCP Example 1 0 Bal 5 0 0 5 2 0 Bal 0 5 0 5 3 0 Bal 0 3 0 1 4 0 Bal 0 15 0 8 5 0 Bal 0 0 5 5 6 0 Bal 3 0 0 5 7 0 Bal 0 3 0 5 8 0 Bal 15 0 0 8 9 0 Bal 0 15 0 5 10 0 Bal 0 0 15 5 Comparative Example 1 Bal 0 5 0 0 5 2 Bal 0 0 5 0 5 3 Bal 0 3 0 0 1 4 Bal 0 15 0 0 8 5 100 0 0 0 0 0 6 Bal 0 0 0 0 5 7 Bal 0 3 0 0 5 8 Bal 0 0 3 0 5 9 Bal 0 15 0 0 5 10 Bal 0 0 15 0 5 11 Bal 0 0 0 5 5 12 Bal 0 16 0 0 0.8 13 Bal 0 5 0 0 9
[0051]
TABLE 2
Base oil
Emulsifier
PAO 1
PAO 2
EM 1
EM 2
EM 3
TCP
Example
11
0
Bal
0
3
0
1
12
0
Bal
15
0
0
8
13
0
Bal
0
15
0
8
14
0
Bal
0
3
0
5
15
0
Bal
0
15
0
5
Comparative
Example
14
Bal
0
5
0
0
5
15
Bal
0
0
5
0
5
16
Bal
3
0
0
0
1
17
100
0
0
0
0
0
18
Bal
0
3
0
0
5
19
Bal
0
15
0
0
5
20
Bal
0
0
0
5
5
21
Bal
0
5
0
0
5
22
Bal
0
16
0
0
0.8
23
Bal
0
5
0
0
9
[0052] The lubricating oil and the lubricating grease were evaluated by the following method. The results are shown in tables 3 and 4.
[0000] <Test for Examining Stability of Torque>
[0053] The tester used was manufactured by the present applicant's company. The torque limiter NTS18 used for the evaluation was manufactured by the present applicant's company. FIG. 5 is an explanatory view for explaining the construction of a tester for examining the stability of the torque. The tester had a motor 6 for rotating the shaft, a torque detection load cell 7 , a coupling 8 , a strain meter 9 , and a recording meter 10 . A torque limiter 11 having a sintered inner ring impregnated with each sample oil was set for the rotational shaft. By rotating the inner ring in the direction in which a torque was generated by the torque limiter, the generated torque was transmitted to the load cell 7 and recorded by the recording meter 10 . A low-speed motor 12 is switched to a high-speed motor 6 or vice versa. The drawing at the left-hand side of FIG. 5 is seen from above.
[0054] The test conditions were set as follows: set torque: 500 gf·cm, number of rotations: 50 rpm, drive cycle: intermittent cycle of drive for 15 seconds and stop for one second, atmospheric temperature: 40° C., humidity: 90%, and period of time in which test was conducted: 400 hours. The following items were measured: feeling of touch on each specimen torque limiters after the test finished; a change of the torque (change with time, fluctuation of torque in one minute) examined at zero hour and at intervals of 200 hours and 400 hours; and whether the torque limiter chattered during the drive of the tester. The torque was measured at zero hour and at the predetermined intervals of 200 hours and 400 hours by the tester shown in FIG. 5 . Reference symbols ◯ and X shown in table 3 indicate the result in the test for examining the stability of the torque. Torque limiters which decreased the torque at not more than 30 gf·cm in one minute were marked by ◯, whereas torque limiters which decreased the torque at more than 30 gf·cm in one minute were marked by X. Torque limiters which gave a good feeling to an examiner in the touch were marked by ◯, whereas the torque limiters which gave a bad feeling to the examiner in the touch were marked by X.
[0000] <Test for Examining Chemical Non-Attacking Property>
[0055] PC (polycarbonate) resin or ABS resin having a high processability is used for parts disposed on the periphery of the torque limiter. Thus there is a possibility that the parts, made of the PC resin or the ABS resin, are cracked or broken owing to contact between the parts and the lubricating oil or the lubricating grease, for use in the torque limiter, which has leaked from the torque limiter. To confirm the chemical-non-attacking property of the lubricating oil of the present invention, the test for examining the chemical non-attacking property was conducted by using the PC and the ABS resin.
[0056] The chemical non-attacking property can be evaluated by carrying out a bending test method. In conducting the bending test, the lubricating grease is applied to the surface of a plate made of the polycarbonate resin and to a plate made of the ABS resin. After a mechanical stress is applied to the plates, the surface of each of the plates is observed.
[0057] The method of conducting the bending test is described below.
[0000] (1) Apparatus for Conducting the Bending Test
[0058] FIG. 6 illustrates an apparatus for carrying out the bending test.
[0059] A bending apparatus 13 has a specimen 14 whose both ends are movably supported by spacing both ends at a predetermined distance L, a test base 15 on which the specimen 14 can be placed, a probe 16 for giving a flexed amount (B) to the specimen 14 , a flexed amount adjusting device 17 supporting the probe 16 to allow the probe 16 to move forward and rearward.
[0000] (2) Test Condition
[0000]
Specimen to be bent: 127 mm (length)×12.7 mm (width)×6.5 mm (thickness)
Distance between specimen-supporting points: 100 mm
Flexed amount of specimen (flexed amount of portion disposed at center between specimen-supporting points): 3.5 mm
Temperature: 70° C.
Time period in which specimen was held: three hours
Material 1 of specimen: Yupiron S2000R (PC resin produced by Mitsubishi Engineering Plastics Inc.)
Material 2 of specimen: Styluck 321 (ABS resin produced by Asahi Kasei Inc.)
(3) Test Method
[0067] A three-point bending test was conducted. Lubricating oil or lubricating grease was applied to the surface of the specimen to be bent which underwent annealing treatment at 120° C. for two hours. The specimen supported at two points spaced at the predetermined distance was flexed in an amount by applying a force to the rear surface thereof. The specimen was held in the air at 75° C. for three hours. Whether the specimen cracked was checked visually. The specimen which was not cracked was marked by “◯”, whereas the specimen which was cracked was marked by X.
[0000] <Emulsifiability Test)
[0068] An emulsifiability test was conducted in accordance with JIS K 2520. The lubricating oil for use in the torque limiter and water were mixed with each other at 1:1 in a weight ratio and stirred to measure an emulsified degree of the water in the lubricating oil in each specimen. Regarding the lubricating grease for use in the torque limiter, the emulsified degree of the water in the base oil was measured in each specimen. The specimen in which the water emulsified in the lubricating oil or in the base oil was marked by “◯”, whereas the specimen in which the water and the lubricating oil separated from each other is marked by X.
TABLE 3 Test for examining Test for examining torque stability chemical non- Time elapsed(hour) Feeling attacking property Emulsifi- 0 200 400 of touch PC ABS ability Example 1 ∘ ∘ ∘ ∘ ∘ ∘ ∘ 2 ∘ ∘ ∘ ∘ ∘ ∘ ∘ 3 ∘ ∘ x ∘ ∘ ∘ ∘ 4 ∘ ∘ ∘ ∘ ∘ ∘ ∘ 5 ∘ ∘ ∘ ∘ ∘ ∘ ∘ 6 ∘ ∘ ∘ ∘ ∘ ∘ ∘ 7 ∘ ∘ ∘ ∘ ∘ ∘ ∘ 8 ∘ ∘ ∘ ∘ ∘ ∘ ∘ 9 ∘ ∘ ∘ ∘ ∘ ∘ ∘ 10 ∘ ∘ ∘ ∘ ∘ ∘ ∘ Comparative Example 1 ∘ ∘ ∘ x ∘ ∘ ∘ 2 ∘ ∘ ∘ x ∘ ∘ ∘ 3 ∘ x x x ∘ ∘ ∘ 4 ∘ ∘ ∘ x ∘ ∘ ∘ 5 ∘ x x x ∘ ∘ x 6 ∘ ∘ ∘ x ∘ ∘ x 7 ∘ ∘ x x ∘ ∘ ∘ 8 ∘ ∘ x x ∘ ∘ ∘ 9 ∘ ∘ ∘ x ∘ ∘ ∘ 10 ∘ x x x ∘ ∘ ∘ 11 ∘ ∘ x x ∘ ∘ ∘ 12 ∘ x x x x x ∘ 13 ∘ ∘ ∘ x x x ∘
[0069]
TABLE 4
Test for examining
Test for examining
torque stability
chemical non-
Time elapsed(hour)
Feeling
attacking property
Emulsifi-
0
200
400
of touch
PC
ABS
ability
Example
11
∘
∘
x
∘
∘
∘
∘
12
∘
∘
∘
∘
∘
∘
∘
13
∘
∘
∘
∘
∘
∘
∘
14
∘
∘
∘
∘
∘
∘
∘
15
∘
∘
∘
∘
∘
∘
∘
Comparative
Example
14
∘
∘
∘
x
∘
∘
∘
15
∘
∘
∘
x
∘
∘
∘
16
∘
x
x
x
∘
∘
∘
17
∘
x
x
x
∘
∘
x
18
∘
∘
∘
x
∘
∘
∘
19
∘
∘
∘
x
∘
∘
∘
20
∘
∘
∘
∘
∘
∘
∘
21
∘
∘
x
x
∘
∘
∘
22
∘
x
x
x
x
x
∘
23
∘
∘
∘
x
x
x
∘
[0070] As indicated in the examples shown in tables 3 and 4, it is necessary to use a required amount of the emulsifier and the base oil (viscosity: 900 mm 2 /S) consisting of the compound of the synthetic saturated hydrocarbon excellent in the chemical non-attacking property so that the torque limiter can maintain a preferable torque performance in an environment having a high temperature and a high humidity and is excellent in its chemical non-attacking property. It is preferable to use the phosphate ester as the wear-resistant agent of the lubricating oil or the lubricating grease.
[0071] The result of the test for examining the torque stability indicates that it is necessary to emulsify water in the base oil which has attached to the surface of a bearing to allow the torque limiter to generate a stable torque in an environment having a high humidity. The test result also indicates that the emulsifier found in the present invention is greatly concerned with the action of emulsifying water in the base oil. In the specimens of the comparison examples 5, 6, and 17 not containing the emulsifier, water which could not be emulsified penetrated into the base oil to generate the breakage of the oil film. Thereby the torque limiter had a failure. As shown in the comparison examples, when the viscosity of the base oil is low, the oil film-forming performance is low, even though the emulsifier is added to the base oil at 3 to 15 wt % as a solution. Thus even though the water penetrates into the base oil and is emulsified, the torque limiter chatters. When the emulsifier is added to the base oil at not less than 15 wt % as a solution, a problem occurs in the solubility of the emulsifier in the base oil and in a long-time stability of the torque. Consequently the emulsifier adversely affects the chemical non-attacking property (comparison examples 12, 22). As described above, the optimum amount of the phosphate ester serving as the wear-resistant agent to be used for the total weight of the lubricating oil is 1 to 8 wt %. If the addition amount of the phosphate ester is below 1 wt %, the lubricating oil or the lubricating grease provides an insufficient torque-stabilizing effect. If the addition amount of the phosphate ester exceeds 8 wt %, the phosphate ester affects the chemical non-attacking property of the lubricating oil or the lubricating grease adversely (comparison examples 13, 23).
[0072] The above-described results indicate that as the lubricating oil or the lubricating grease, for use in the torque limiter, which allows the torque limiter to generate a torque stably in the environment having a high temperature and a high humidity and which has an excellent chemical non-attacking property, it is preferable to use the compound of the synthetic saturated hydrocarbon as the base oil, use 1 to 8 wt % of the phosphate ester for 100 wt % of the base oil, and as the emulsifier, use 3 to 15 wt % of the metallic salt of sulfonic acid for 100 wt % of the base oil.
[0073] The torque limiter of the present invention generates a stable torque that fluctuates little in the environment having a high temperature and a high humidity. Further since the lubricating oil or the lubricating grease having an excellent chemical non-attacking property is used for the torque limiter, the torque limiter can be preferably used in the environment having a high temperature and a high humidity in which it is difficult to lubricate the torque limiter. | A torque limiter comprising an inner ring fitted inside an outer member; and a torque transmission member interposed between said inner ring and said outer member. A predetermined torque is generated by a friction generated between said inner ring and said torque transmission member, when said inner ring and said outer member rotate relatively to each other. The members are impregnated with lubricating oil to slide said members on each other. The lubricating oil contains a base oil consisting of synthetic saturated hydrocarbon oil having a kinematic viscosity of 500 to 1200 mm 2 /s at 40° C. and an emulsifier added to said base oil. The lubricating grease contains the base oil consisting of the synthetic saturated hydrocarbon oil having a kinematic viscosity of 500 to 1200 mm 2 /s at 40° C. and an emulsifier and a thickener both added to said base oil. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a divisional application of U.S. patent Ser. No. 10/686,325, filed Oct. 14, 2003, pending, which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates generally to door constructions and more particularly, to replaceable door edge arrangements.
BACKGROUND OF THE INVENTION
One popular form of vertically hung doors typically comprises a wooden frame defining outer dimensions of the door, panels of sheet material, such as plywood, plastic or metal covering the frame or both sides, and a core within the frame, which may be solid or hollow.
In certain high traffic environments, for example, schools, hospitals and other types of health care institutions, doors are often subjected to impacts from carts, wagons, dollies, etc. which take their toll on the doors, particularly along their free edges and the hinged edges. Nicks, gouges and cracks produced along door edges by such impacts compromise a door's ability to effect a secure closure, which is particularly important where the door serves as a fire barrier as well as a closure, and mar its aesthetic appearance.
Heretofore, when a door edge was severely damaged, it was necessary either to replace the door in its entirety or to refinish it. With the latter expedient, the door panels may also have to be replaced and, in any event, the door will have to be refinished as well. The cost of maintaining the structural integrity and appearance of the many doors in a hospital, for example, can become substantial.
SUMMARY OF THE INVENTION
The object of the present invention is to minimize the necessity of replacing or refinishing doors that have been severely damaged along their edges by enabling a damaged door edge to be simply and inexpensively restored.
The foregoing object is achieved by constructing a door with a replaceable edge strip or stile which, when damaged, can be readily removed and replaced with a new one, thereby restoring the door's integrity and appearance. In accordance with the invention, this is achieved by so constructing the door such that the replaceable edge strip or the replaceable stile can be removed and replaced without affecting the door frame or door slab, thus eliminating the need for otherwise replacing or refinishing the door. The stile is so configured that it can be covered with a plastic cap that provides an extra layer of protection against damage and helps maintain a snug seal against a doorway or an opposite door.
Another feature of the invention is the incorporation in the replaceable door edge assembly of an intumescent (heat expanding) material such that in case of fire, the edge is expanded outwardly to effect a tighter seal with the surrounding doorway or opposite door. The fire safety rating of the door is thus improved.
Still another feature of the invention is the incorporation in the door edge construction of an accent material to provide a reveal, or line of color different than the door panel color, for aesthetic and/or identification purposes.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other features and advantages of the invention will become apparent from the following detailed description thereof, taken in conjunction with the appended drawing, in which:
FIG. 1 is an oblique view partially cut away, of a door incorporating the present invention;
FIG. 2 is a cross-section of the door of FIG. 1 , taken along the line 2 - 2 ;
FIG. 3 is an enlarged view of the right-hand portion of the cross-section view of FIG. 2 showing the door edge construction of the invention in greater detail;
FIGS. 4A , 4 B and 4 C illustrate modifications of the door edge construction of FIG. 3 ;
FIG. 5 is an enlarged cross-sectional view similar to FIG. 3 illustrating the incorporation of an intumescent strip in the door edge construction of the invention;
FIG. 6 illustrates a modification of the door edge construction of FIG. 5 ;
FIGS. 7A , 7 B, 7 C and 7 D illustrate the replaceable door edge construction of the invention incorporating various types of accent strips or reveals
FIGS. 8A and 8B illustrate variations of the invention embodying an alternate tongue and groove arrangement for securing the replaceable stile to the door edge;
FIG. 9 illustrates a variation of the invention in which the tongue and groove members are covered with metal channels;
FIG. 10 illustrates a modification of the arrangement of FIG. 9 ;
FIGS. 11 and 12 illustrates variations of the arrangement of FIG. 9 ; and
FIG. 13 illustrates a replaceable stile arrangement in accordance with the invention in which the width of the replaceable stile is adjustable.
DETAILED DESCRIPTION OF THE INVENTION
Turning now to the drawings, in particular FIGS. 1 , 2 and 3 , a door of the type commonly used in health care facilities and the like, but incorporating the present invention, is shown. Such a door 20 typically comprises vertical stiles 22 and top and bottom rails 24 , surrounding a core 26 . The stiles 22 and rails 24 preferably are made of hardwood and the core 26 of particle board, although other materials may be used to provide the necessary strength and rigidity.
Finish panels 28 cover the particle board core, top and bottom rails and stiles on both sides to provide strength, impact resistance and aesthetic appeal. As seen best in FIG. 3 , the panels 28 may comprise a hardboard layer 28 a covered by a decorative plastic cladding 28 b such as of ACROVYN®, a vinyl acrylic plastic manufactured by Construction Specialties, Inc., Lebanon, N.J. The layers 26 , 28 a and b are laminated together to form a 5-ply construction. Doors of the type illustrated are manufactured, for example, by Jeld-Wen, Inc.
Doors 20 may be made in dimensions to fit various size doorways in which they are mounted. As will be appreciated, the door 20 may be hinged to swing around along either vertical edge to suit the application. In a typical installation often found in health care facilities, a pair of such doors are hinged at opposite edges to close a wide hallway and are swingable in both directions so that rolling beds, carts, etc may be pushed through without the need to hold the door open.
As discussed above, such doors are subjected to repeated, severe impact by beds, carts, etc., as they are pushed through the doors, often resulting in significant damage to the free vertical edges of the doors. Not only is the appearance of the door thus marred, the integrity of the closure and its fire resistance capability is degraded. Heretofore, in the case of significant edge damage, it was necessary to completely replace a damaged door with a new one to restore the closure's appearance and integrity, at substantial cost.
In accordance with the present invention, the vertical edges of a door such as described herein are fabricated with separable edge assemblies that can be readily replaced if damaged, thereby avoiding the necessity of complete door replacement and greatly reducing the cost of restoring the door's appearance and integrity.
A preferred embodiment of the removal door edge arrangement of the invention is shown in FIGS. 1 , 2 and 3 ; most clearly in the enlarged section through a door edge of FIG. 3 . The vertical door stile is indicated at 22 and the replaceable edge assembly indicated at 30 . The latter comprises replaceable stile 32 , preferably of hardwood, extending the full length of the edge stile 22 and a plastic cover 34 secured over replaceable stile 32 . Stile 22 is milled with a longitudinal tapered grove 22 a and replaceable stile 32 with a longitudinally extending complementary tapered spline 32 a , forming a snug tongue-and-groove mating of stile 22 and replaceable stile 32 . A plurality, e.g., 4, of screws 36 , spaced along the door edge, firmly but releasably secure replaceable stile 32 to stile 22 . If desired, spots of glue may also be applied between stile 22 and replaceable stile 32 to more firmly hold them together, while still allowing replaceable stile 32 to be removed when required.
Cover 34 may be formed of ACROVYN® or other relatively hard but resilient material, such as aluminum or stainless steal, with inwardly directed flanges 34 a along both edges. Cover 34 is formed to be of the same shape as the outer surface of replaceable stile 32 , e.g., generally rectangular with rounded corners. Replaceable stile 32 is provided with rectangular indents 32 b along both inner longitudinal edges, such that when stile 22 and replaceable stile 32 are joined, rectangular grooves 32 b are formed therebetween extending the full length of the door. These grooves snugly receive the flanges 34 a of cover 34 . To remove a damaged cover from a door, one of the flanges 34 a is pried out of its groove and the cover bent away to release the other flange. To install a new cover, one of the flanges is inserted into its groove and the cover pressed toward the outer surface of replaceable stile 32 until the other flange snaps into the other groove.
It will be understood that the curvature of the corners of the stile and cover combination discussed and illustrated may be varied to suit the particular application. For example, for paired swinging doors, such as often found across hospital passageways, the corner curvature will be of greater radius than single doors, to provide the required clearance.
It will also be understood that the cover 34 need not be removable, but may be permanently secured to its replaceable stile 32 , such as by a suitable adhesive. In such an arrangement, flanges 34 a and indents 32 b may be unnecessary.
FIGS. 4A , 4 B and 4 C illustrate alternative forms of the tongue-and-groove coupling of FIG. 3 , with the screws omitted for the sake of clarity. In FIG. 4A , a dovetail spline 42 mates with a corresponding grove 44 ; in FIG. 4B , the spline 46 has a partially circular cross-section to mate with a partially circular groove 4 B; and in FIG. 4C , the spline 50 and groove 52 are rectangular in cross-section. It will be understood that other variations of the tongue-and-groove cross-sections may be used as desired.
FIG. 5 illustrates another embodiment which further enhances the fire resistance advantages of doors of the invention. A heat-expansion or intumescent strip 52 extends the full length of the door edge and is adhered in a groove 54 milled along the outer edge of replaceable stile 32 . Cover 34 may have a complementary groove along its inner surface to accommodate the strip as well. The strip 52 is covered by outer cover 34 when the latter is snapped in place. At normal room temperatures, strip 52 maintains its normal thickness. In case of fire or extreme heat adjacent the door, strip 52 expands, pushing cover 34 outwardly to tighten the seal between the edge of the door and an adjacent door or doorframe, thus increasing the fire resistance rating of the door.
A variation of the arrangement of FIG. 5 is illustrated in FIG. 6 wherein the intumescent strip 52 is adhered in a groove 34 a formed in the outer edge of cover 34 , the inward extension of the cover 34 fitting in a groove milled along the outer edge of replaceable stile 32 .
It will be understood that in the embodiments of FIGS. 5 and 6 , any of the tongue-and-groove couplings described above may be used in place of the configurations illustrated.
To improve the appearance of the door, an accent strip or reveal, of a contrasting or complementary color to the remainder of the door surface, may be incorporated in the door edge arrangements of FIGS. 3 to 6 . In the embodiment of FIG. 7A , longitudinal grooves 60 are milled along opposite sides of replaceable stile 32 , inwardly of its interior face, for receiving the flanges 34 a of cover 34 , leaving exposed narrow longitudinal surfaces 62 on opposite sides of the stile, between cover 34 and the panels 28 . These exposed surfaces 62 may be painted in any aesthetically pleasing color.
The reveal or accent strip may also be provided by insertion of a suitably colored strip of accent material in a slot provided between the stile 22 and replaceable stile 32 , as shown in FIG. 7B . As seen, stepped indents 64 are provided along each inner corner of replaceable stile 32 to receive the flanges of cover 34 and accent strips 66 . The strips 66 may be of PVC plastic, aluminum, stainless steel or other material having their outer surfaces ridged and slightly thicker than the grooves created upon joinder of replaceable stile 32 to stile 22 . The strips 66 are pressed into the grooves after cover 34 is inserted and the ridged surfaces resist any tendency of the strips to move out of the grooves.
A variation of the accent strip of FIG. 7B is illustrated in FIG. 7C . In this modification, the inside longitudinal edges of replaceable stile 32 are milled to provide both stepped indents and longitudinal grooves for receiving L-shaped accent strips 68 . One leg of each accent strip extends outwardly to just below the respective outer surface of the door with its edge exposed when replaceable stile 32 is joined to stile 22 with the accent strip in place.
In the embodiment of FIG. 7D , the accent strips comprise opposite exposed edges 70 of a strip 72 sandwiched between stile 22 and replaceable stile 32 .
The accent strips of FIGS. 7B-D may be made of any suitable material, including PVC plastic, aluminum and stainless steel.
FIGS. 8A and 8B illustrate variations of the tongue and groove arrangements of the invention shown in the previous embodiments. In both variations, the groove in the stile 22 is rectangular (as in FIG. 4C ) and lined with a U-shaped channel 80 having longitudinal ridges 82 formed along both interior sides of the channel. Channel 80 is secured in the rectangular groove milled in stile 22 by screw 84 .
Adhered along the inner surface of replaceable stile 32 is a tongue plate 86 having integral longitudinal extending flanges 88 with longitudinally extending ridges 90 formed along their outer surfaces. The pair of flanges 88 and channel 80 are dimensioned such that the flanges are snugly received within the channel and the respective ridges 82 , 90 engaged to secure replaceable stile 32 to stile 22 . Tongue plate 86 may extend the full width of stile 32 , with rounded edges extending slightly beyond the door panel as in FIG. 8A , or be narrower than the width of the stile and received in a depression milled in the inner surface of replaceable stile 32 , as in FIG. 8B . In the embodiment of FIG. 8A , the rounded extensions of the tongue plate 86 may serve as accent strips. In FIG. 8B , accent strips are provided by inserts 92 between the edges of cover 34 and stile 22 . In both embodiments, intumescent strips 52 may be provided.
Channel 80 and tongue plate 86 may be made of aluminum or other metal or plastic, as desired.
In the embodiment of FIG. 9 , a dovetail tongue and groove coupling between stile 22 and replaceable stile 32 , such as shown in FIG. 4A , has both tongue 94 and groove 96 covered with channels of this aluminum, steel, or other material providing low friction slideable surfaces, 98 a and 98 b , respectively, which extended to the outer surfaces of the door. The covered channels facilitate the insertion and removal of replaceable stile 32 on stile 22 .
A variation of the embodiment of FIG. 9 is shown in FIG. 10 , in which the extents of the metal channels 100 a and 100 b are limited to the extents of the groove and tongue, respectively. The space left between stile 22 and replaceable stile 32 is filled with tapered inserts 102 , which serve to wedge the members 22 , 32 apart and also to provide accent strips.
In FIG. 10 , a single metal channel 110 is applied to the dovetail tongue element only and in FIG. 11 , the single metal channel 112 is extended outwardly between stile 22 and replaceable stile 32 to the door faces with rounded outer edges 114 which provide accent strips.
To accommodate different door thicknesses, the adjustable width replaceable stile of FIG. 13 is advantageous. In this embodiment, the replaceable stile is made up of two separate longitudinal elements 132 a and 132 b , each having a generally L-shaped cross-section overlying and nesting with each other to be slideable away from each other between a minimum width arrangement wherein the respective longitudinal edges of elements 132 a and 132 b are in contact with each other and a maximum width configuration wherein the respective longitudinal edges are separated. Opening 134 is of greater diameter than screw 36 to allow for varying amounts of separation.
It will be seen from the foregoing that the present invention provides a simple, inexpensive way of repairing damaged doors by allowing replacement only of a removable door edge assembly, thereby saving the considerable exposure of replacing an entire door. Although a number of specific embodiments of the invention above have been illustrated, various modifications thereof will be apparent to those skilled in the art within the spirit of the invention. For example, replaceable stile 32 and cover 34 may be made as a single integral member and joined to stile 22 as shown. Also, the tongue-and-groove coupling between replaceable stile 32 and stile 22 may be eliminated, if desired and any of these variations may be provided with or without intumescent strips. Accordingly, it will be evident that the scope of the invention is to be limited only as set forth in the appended claims. | A door is constructed with a separate member joined to the door edge by a tongue-and-groove coupling and screws so as to be readily removable and replaceable. The separate member sustains the impacts imparted to the door by carts or wagons pushed past the door and can be readily replaced when damaged, thus avoiding replacement of the entire door. A flexible cover snaps over the outer surface of the separate member to add impact resistance and aesthetic appeal. Intumescent strips may be inserted inside or outside of the cover to enhance sealing between the door, and as adjacent door or door frame, thereby improving the fire resistance rating of the door. Accent strips or reveals of contrasting or complementary colors may be incorporated to add to the aesthetic appeal of the door. The door construction is of particular utility in schools, health care facilities and other institutions. | 4 |
STATEMENT OF GOVERNMENT INTEREST
The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.
BACKGROUND OF THE INVENTION
This invention relates generally to visual displays, and, more particularly to a pointer capable of being used at remote locations in conjunction with a viewgraph presentation or the like in which the necessity of the briefer being present at the remote location is eliminated.
The use of visual display systems, and in particular, viewgraph presentations in which particular portions of the viewgraph are to be denoted by the briefer is having increasing significance in both military and non-military applications. Unfortunately, such a presentation results in sizeable costs in travel and man hours in order to provide for the briefer to be present during this visual presentation. Since in many instances the visual presentation forms only a small portion, timewise, of the entire presentation, justification cannot be made for the briefers travel.
Unfortunately, the visual presentation, to be properly understood, often requires the use of a pointer, with the actual physical presence of the briefer being generally required for the proper utilization of the pointer during the presentation. Other portions of the presentation can be successfully accomplished by conference call or the like. Therefore, it is essential for the best utilization of time, personnel and equipment that a remote pointing system be developed for use with such visual presentations, that is, a pointing system that does not require the presence of the briefer at the remote location.
SUMMARY OF THE INVENTION
The instant invention sets forth a pointing system which does not require the presence of the briefer and is capable of utilization in conjunction with a visual presentation at a remote location, thereby overcoming the problems encountered in the past and as set forth hereinabove.
The utilization of the remote pointing system of this invention requires, prior to delivery of the visual presentation, the briefer to forward to the remote location one set of two sets of identical viewgraphs. The delivery of the presentation can then be accomplished at the location of the briefer (hereinafter called the transmitting location) which is linked to the remote location (hereinafter called the receiving location) by normal linkage through conventional conference telephone equipment so that the briefer can be heard in the remote location. The two sets of identical viewgraphs are shown simultaneously at the transmitting location and receiving location. Synchronization of the showing of the viewgraphs is accomplished in a conventional manner (such as by voice communication or buzzer) through use of the conference link.
The instant invention is designed for utilization with the arrangement set forth hereinabove by providing a pointing system which incorporates therein a pair of pointers. One pointer, located at the transmitting station, is used by the briefer while the other pointer is located at the receiving location. The pointers are coordinated with the viewgraph presentation without the actual presence of the briefer being necessary. In addition, the pointing system of this invention has the capability of requiring only a normal telephone line, or, could, if desirable, use some of the bandwidth of the conference call line.
Each pointer is generally in the form of a small handheld-type laser operating at a preselected wavelength and is utilized at the transmitting location in a similar manner to a conventional light pointer. Located in the room with a projection screen and optically aligned therewith, is a conventional television pick-up device (a vidicon camera, for example) having an optical filter interposed between the screen and the television pick-up capable of passing therethrough only the very narrow band of the preselected laser wavelength. Thus, the television pick-up device develops a large output signal when its scan position is at the image of the laser pointer spot position. The position of the scan at the time of the large video output signal due to the pointer beam is transmitted to the receiving or remote location via a conventional telephone line.
At the receiving location the other laser pointer, equivalent to the pointer used at the transmitting location, is positioned in either a movable gimbal mount or used with appropriate mirrors so as to position the laser pointer spot on the viewgraph located at the receiving (remote) location in the appropriate position. The laser axis, or positioning mirrors are controlled by a microcomputer capable of receiving the telephone signal (through appropriate interface electronics) and translating it into signals which are capable of positioning the laser pointer so as to produce a laser spot accurately on the viewgraph at the receiving location.
It is therefore an object of this invention to provide a remote pointing system which can be utilized in conjunction with a viewgraph presentation at a remote location without the necessity of the presence of the briefer at the remote location and without in any way interfering with or altering the normal manner in which the presentation is delivered at the transmition location or seen at the remote (receiving) location.
It is another object of this invention to provide a remote pointing system which is capable of utilizing conventional telephone or voice lines for transmitting the signals associated therewith.
It is a further object of this invention to provide a remote pointing system which is economical to produce and which utilizes conventional, currently available components that lend themselves to standard mass producing, manufacturing techniques.
For a better understanding of the present invention together with other and further objects thereof, reference is made to the following description taken in conjunction with the accompanying drawing and its scope will be pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a pictorial representation of the pointer of the remote pointing system of this invention positioned at the transmitting location and utilized in conjunction with a viewgraph presentation;
FIG. 2 is a pictorial representation of the pointer of the remote pointing system of this invention positioned at the receiving location during a viewgraph presentation; and
FIG. 3 is a schematic representation of the circuitry of remote pointing system of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference is now made to FIGS. 1 and 2 of the drawing. FIG. 1 pictorially represents the transmitting location at which an individual 10 acts as a briefer and FIG. 2 of the drawing pictorially represents the receiving or remote location with which the remote pointing system 12 of this invention is utilized. At each the transmitting and receiving locations, respectively, a screen 14 is set up in its proper relationship with an audience for viewing viewgraphs or the like. In addition, a pair of viewgraph projectors 16, one at each location, are utilized with screens 14 for projecting onto screen 14 the viewgraphs 18.
The remote pointing system 12 of this invention is made up of a first light emitting pointer 20 which briefer 10 utilizes at the transmitting location, a second light emitting pointer 22 located at the receiving location and the associated circuitry to be more fully described in detail hereinbelow.
Each pointer 20 and 22 is generally in the form of a conventional, handheld-type of helium-neon laser such as the Hughes Model 3221 H or 3021 H laser operating at a wavelength of 632.8 nm. The output of each pointer 20 and 22 is directed onto respective screens 14 in a similar manner to a conventional light pointer. Conventional optics are used to give a suitable size spot 24 and 26, respectively, on the viewgraphs 18 while a mask and conventional optics can be utilized, if desired, to form an arrow or other figure on the projection screen 14.
The circuitry making up this invention is more fully described below and schematically illustrated in FIG. 3 of the drawing. Circuitry 25, located at the transmitting location, comprises an appropriate filter 28, a conventional TV camera such as a vidicon camera 30, a pair of conventional counters 32 and 34 and a conventional modem 36. The circuitry 27 located at the receiving location comprises a conventional telephone receiver 38, a conventional modem 40, a conventional microcomputer 42 and a pair of conventional analog to digital converters 44 and 46, respectively. As shown in FIG. 2 of the drawing a pair of conventional galvanometer-type deflectors (including mirrors) 52 and 54 of the type generally available from General Scanning Inc., Watertown, Mass., are operably connected to the output of converters 44 and 46. Although the particular elements set forth above provide an operative embodiment of the remote pointing system 12 of this invention, it should be realized that additional conventional elements may also be required or equivalent elements can be utilized within the scope of this invention. In addition, circuitry 25 located at the transmitting location and circuitry 27 located at the receiving location are interconnected by means of a conventional telephone line 56 or the like.
Referring once again to FIG. 1 of the drawing, the entire area of projection screen 14 is imaged onto the television or video camera 30. Filter 28 is optically interposed between vidicon camera 30 and the image on screen 14 in order to pass only a very narrow band of wavelengths therethrough, that is, the output wavelength of laser pointer 20, about 632.8 nm. Thus, the TV pickup, vidicon camera 30 will have a large video output signal 31 when its scan position is at the image of the helium neon laser pointer spot position 24.
Vertical and horizontal synchronizing pulses are taken from vidicon camera 30 directly or are stripped from the camera video output as in any conventional TV receiver (as described, for example, in A. Schure, "Basic Television", vol. 4 "TV Receiver Circuit Explanations", John F. Rider Inc. 1958). Conventional digital integrated circuit components, not shown, (as described, for example in "E. R. Hnatek", "A Users Handbook of Integrated Circuits", John Wiley & Sons, 1973) are used to reset and start the two conventional binary counters 32 and 34 on the first horizontal sync pulse following a vertical sync pulse, the latter being smoothed, again as in a conventional TV camera. One counter 32 counts horizontal sync pulses following the one that reset it. The other counter 34 is reset by each horizontal sync pulse and counts pulses from a conventional 4 MHz repetition rate pulse generator (not shown). Both counters 32 and 34 are stopped and the count held by the video signal caused by the helium neon laser spot image 24. A conventional discriminator circuit (not shown) is used to give a sharp video pulse close to the center of the spot. In the above manner counter 34 holds a number representing the horizontal position of spot 24 while the number in counter 32 represents the vertical position of spot 24.
Initially the TV camera or vidicon camera 30 is set up so that it images a slightly larger area (approximately 20% larger) than the area of a projected viewgraph 18 (slide, etc) to be used. In this way it is assured that the two numbers in counters 32 and 34 are less than 256 and can therefore be represented by 8 binary bits. This is so for the horizontal because there are 262.5 horizontal lines per TV scan field, so that a horizontal line lasts for 63.5 u sec. Consequently, there will be fewer than 254 pulses from the 4 MHz generator per scan line. The two eight bit numbers are sent over conventional telephone line 56 through a conventional modem 36, a modem being a device that performs modulation or demodulation in the form of a signal conversion, interfacing computers or computer peripheral equipment to the telephone line. If every 12th vertical sync pulse is used, then five pairs of eight bit numbers will be sent per second, a sufficient rate for the remote pointing system 12 of this invention. Even if a parity bit is included, a conventional 110 baud line can be used.
At the receiving location as shown in FIG. 2 of the drawing the input signal introduced by means of telephone line 56 is fed into any conventional telephone receiver 38. The signal 39 emanating from receiver must now be converted into a signal 41 which is acceptable to microcomputer 42. This is accomplished by means of any suitable converting device such as conventional modem 40 in a procedure reverse to the procedure performed by modem 36. Microcomputer 42 such as the LSI 11 microcomputer from Digital Equipment Corporation puts out two signals 43 and 45 in the form of 8 digit binary numbers at a suitable voltage level (e.g. 3 volts) into each of the two D/A converters 44 and 46.
Also at the receiving location as shown in FIG. 2 of the drawing the second helium neon laser is used as pointer 22 with suitable focusing optics (not shown) to control the size of spot 26. Pointer 22 is mounted in any suitable mount 60 with appropriate deflectors in the form of adjustable mirrors 52 and 54 utilized to control the X-Y (horizontal and vertical) axis of spot 26 on viewgraph 18. If desired, however, the mirrors 52 and 54 may be eliminated and the laser pointer 22 mounted in a conventional gimbal mount with suitable positioning motors. The output of each D/A converter 44 and 46, respectively, is amplified with one driving the X-axis deflector or mirror 52 and the other the Y-axis deflector or mirror 54.
For the operating sequence of the remote pointing system 12 of this invention reference is once again made to FIGS. 1 and 2. During such an operation it is first necessary for the briefer 10 to send by any suitable means one set of a pair of identical sets of viewgraphs 18 to the remote location (receiving location) where the briefing session is to be held. It is essential that the viewgraphs 18 at both the location of briefer 10 (the transmitting location) and the remote location (the receiving location) be shown simultaneously. The briefer's oral presentation, including instructions to change the viewgraph (using buzzers, tones, or verbal instruction) are conveyed to the receiving location by way of a conventional telephone conference call hookup. The pointer spots 24 and 26 at the transmitting and receiving stations are maintained at the same place on viewgraphs 18 by keeping all viewgraphs 18 at each location at the same position on each screen 14, for example, by using reference marks on the projectors 16 or screens 14.
An initializing procedure is used with this invention to synchronize pointer spots 24 and 26 at each location before the briefing can begin or it can be repeated if necessary during or between briefings. The initializing procedure begins by focusing the transmitting pointer 20 at the upper left and lower right hand corners of viewgraph 18 on screen 14. The operator (not shown) at the receiving location, upon being told over the conference line that the upper left is being pointed to, enters, according to a suitable microcomputer program, a code on the keyboard of microcomputer 42, for example, UL. Microcomputer 42 then stores the received two eight bit binary numbers (X U , Y U ) in memory. The same procedure is carried out to store in other memory locations the number (X L , Y L ) associated with the lower right.
At the receiving location an appropriate program is written such that a code for upper left, for example, ULR, entered on the keybroad causes microcomputer 42 to put out all zeros into D/A converters 44 and 46, respectively. The X and Y deflectors or mirrors 52 and 54 are adjusted so that the laser spot 26 falls upon the upper left hand corner of the viewgraph image on screen 14. Another code into microcomputer 42, for example, LRR, causes all ones in each binary number (binary 255) to be output to D/A converters 44 and 46, respectively. The output of D/A converters 44 and 46 is fed into amplifiers 47 and 49 associated with each deflector 52 and 54, respectively. The gain in each amplifier 47 and 49 is now adjusted so that the laser spot appears in the lower right hand corner. This initiating procedure is similar in nature to the procedure used with conventional desktop computer X-Y plotters (such as the Hewlett Packard Model 9825 computer, model 9872A plotter) to initialize to and refer all corrdinate points to the paper size and position. Such a procedure corresponds to the viewgraph magnification and location on screen 14.
The system is now ready for operation. In actual operation, the microcomputer 42 receives two eight bit binary numbers, as described above, for example, (X, Y). It then computes two new numbers (X, Y) which it outputs to D/A converters 44 and 46. The numbers (X, Y) are defined by ##EQU1## with each number rounded off to the nearest integer. It is then possible for a briefer 10 at one location to transmit by means of the remote pointing system 12 of this invention the position spot 24 of pointer 20 to a remote location for use with a viewgraph 18 at the remote location. Any movement of pointer 20 is relayed by way of telephone line 56 to pointer 22 for similar movement thereof. Consequently, the briefing session can be performed at the remote location without the actual physical presence of briefer 10.
Although this invention has been described with reference to a particular embodiment, it will be understood to those skilled in the art that this invention is also capable of further and other embodiments within the spirit and scope of the appended claims. | A remote pointing system which permits the remote positioning of a laser beam in accordance with signals received from a laser beam situated at another location. These signals are derived through the use of an appropriate filter, television camera, pair of counters and modem located at the transmitting location and a telephone receiver, modem, microcomputer, pair of analog to digital converters and suitable beam directing means at the remote or receiving location. By interconnecting the above-mentioned elements by way of a telephone line and proper interfacing of electronics, positioning of the remote laser beam can be accurately and reliably accomplished. | 6 |
FIELD OF INVENTION
This invention relates generally to electronic ballasts, and in particular to an electronic ballast which boosts starting frequency and voltage to facilitate starting of gas discharge lamps.
BACKGROUND OF THE INVENTION
Gas discharge lamps, such as fluorescent lamps, require a higher than normal operating voltage to be applied as a starting voltage to ionize the gas within the lamp. Traditionally, iron core and coil ballast systems operating at a frequency of 50-60 Hz have been employed to generate the higher than normal operating voltage. Iron core and coil ballast systems, however, are characterized by a low power factor, heavy weight, and large physical size. Additionally, they generate harmonics, radiate an audible buzz, and produce a bothersome light flicker.
DESCRIPTION OF THE PRIOR ART
In an improved starting technique, solid-state high frequency electronic ballast systems have been employed which use ferrite core transformers, improve the power factor, are smaller in size and less in weight, and produce virtually no audible noise. For soft start operation, the frequency of the filament voltage is temporarily increased to pre-heat the filaments. The Q factor of the starting circuit is relatively low under those conditions, so the lamp will not start and the filaments will not wear out as fast, while the filaments are being heated. While these types of ballasts have been known for a number of years, they have not been effective for use with the two pin compact fluorescent lamps.
An example of such a two pin lamp is described in U.S. Pat. No. 4,862,035, entitled "Fluorescent Lamp Unit Having Plural Separate Tubes In Particular Arrangement Of Circuit Elements". This type of lamp was not easily adapted for use with electronic ballasts because of its internal capacitor designed for starting with ballasts at a low frequency, typically 50 to 60 Hz.
SUMMARY OF THE INVENTION
The present invention discloses a system and a method for starting a gas discharge lamp by increasing tile driving power by raising the amplitude and the frequency of the starting voltage for a predetermined period of time. After the predetermined period of time lapses, a lower operating power level is accomplished by lowering the frequency and starting voltage in order to resume normal lamp operation. Switched mode control circuitry having an adjustable boost voltage is employed along with an oscillator having a first frequency for starting the lamp and a second frequency for steady state operation.
AC line voltage is rectified and applied to the boost regulator for stepping up the DC voltage. The boost voltage is applied to an inverter which chops the DC voltage into a high frequency AC voltage. The high frequency voltage is passed through an LC circuit or transformer to provide the appropriate matching impedance to the lamp.
A kickstart circuit is coupled to the boost regulator and to an oscillator which controls the chopping frequency of the inverter. On power up, the kickstart circuit boosts the start voltage and increases the oscillator frequency for a predetermined period of time for pre-heating the lamp.
One advantage of the present invention is that it incorporates desirable features of an electronic ballast while maintaining compatibility with low frequency, thermo-mechanical starting type lamps which incorporate a glow element. Another advantage of the present invention is that it is relatively small and light weight, is easily produced, has a power factor substantially near unity, and has substantially constant power output over a wide input voltage range.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings in which like reference numerals and letters indicate corresponding elements throughout the several views:
FIG. 1 is a general block diagram of the present invention;
FIG. 2 is an electronic ballast system practiced in accordance with the principles of the present invention; and
FIG. 3 is a simplified block diagram of the pulse width modulation (PWM) control circuit of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the following description of the preferred embodiment, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration a specific embodiment in which the invention may be practiced. It is to be understood that other embodiments may be utilized and circuit changes may be made without departing from the scope of the present invention.
Before describing the particular improved electronic ballast system and method practiced in accordance with the principles of the present invention, it should be noted that the invention resides primarily in a novel combination of conventional electronic circuits and not in a particular detailed configuration thereof. Accordingly, the structure, control, and arrangement of these conventional circuits have been illustrated in the drawings by readily understandable block representations and schematic diagrams, which show only those specific details that are pertinent to the present invention. Thus, the block and schematic diagram illustrations in the figures do not necessarily represent the specific circuit arrangement of the exemplary system, but are primarily intended to illustrate major components in a convenient functional group, wherein the present invention may be more readily understood.
Reference is made to FIG. 1 which shows a general block diagram of the present invention. AC line voltage 12 is impressed on bridge rectifier 10. A boost regulator 11 has a first input coupled to the bridge rectifier output and a second input coupled to feedback from its output. The boost regulator 11 is a closed loop device for stepping up the DC voltage in response to a control input from a kickstart circuit 15. The output of the boost regulator 11 is coupled to an inverter 13 which chops the stepped up DC voltage at a high frequency. The output of the inverter 13 is preferably transformed by an LC circuit to provide a high Q and matching impedance before application to the lamp 44.
The kickstart circuit 15, upon power up, steps up the boost voltage of regulator 11 and the frequency of oscillator 38 for a predetermined period of time. The increased amplitude and frequency expedites the ionization of the gas within lamp
Reference is now made to FIG. 2 which shows an electronic ballast practiced in accordance with the principles of the present invention. The bridge rectifier 10 has impressed on it an AC voltage 12 of a frequency typically between 50-60 Hz and produces a rectified DC voltage on output conductor 14. Filter capacitor 16 filters the AC ripple as well as any high frequency noise produced by oscillator 38 on line 14. Inductor 18 has a first terminal coupled to capacitor 16 and the rectified DC voltage on line 14 and a second terminal coupled to the junction of the anode of diode 20 and switch 22. The output line 14 charges inductor 18 through closed switch 22 and current sense resistor 24. The current sense resistor 24 is of ample wattage rating to withstand high current flow through switch 22. The opening and closing of switch 22 is controlled by pulse width modulation (PWM) control circuit 26 described in more detail below. In the preferred embodiment, the switch 22 is a field effect transistor (FET) with ample voltage and current ratings to withstand the flyback operation of inductor 18.
Collectively, the inductor 18, switch 22, resistor 24, and PWM control circuit 26 cooperate together as a boost or step-up regulator 11. The boost voltage impressed across capacitor 32 through diode 20 is proportional to the sum of the voltage across capacitor 16 and the voltage produced by the inductance (L) of inductor 18 multiplied by the change in current (di/dt) through it. The step-up regulator 11 operates in a discontinuous flyback mode wherein oscillator 38 via PWM control circuit 26 turns on switch 22 and feedback from resistors 24 and 30 (30A and 30B) turns it off. When switch 22 is turned on by the PWM control circuit 26, the DC voltage on line 14 is impressed across conductor 18, switch 22, and resistor 24. The current ramps up and the inductor 18 stores energy in its core. When switch 22 is turned off from feedback from resistors 24 and 30, the voltage across the inductor 18 kicks back to resist the change in current (di/dt). The voltage across capacitor 16 and the voltage produced by the L.di/dt is impressed on capacitor 32 through diode 20. Diode 20 separates inductor 18 and capacitor 32, thus allowing for the voltage across capacitor 32 to be larger than the voltage impressed at line 14.
Resistors 28 and 30 located on the cathode side of diode 20 form a voltage divider providing a second input voltage to PWM control circuit 26. The voltage across resistor 30 is proportional, through voltage division, to the boost voltage across capacitor 32. The feedback voltage to PWM control circuit 26 from resistors 24 and 30 provides current and voltage information respectively so that power delivered through diode 20 to capacitor 32 is maintained constant. The maximum level of peak current through inductor 18 is set by the output 63 of error amplifier 62 (FIG. 3). The error amplifier 62 compares the voltage across resistor 30 (which is proportional to the boost voltage) to a reference voltage (V REF ) produced by reference generator 61. The reference voltage V REF and the ratio of resistors 28 and 30 are preselected so that the desired boost voltage is maintained across capacitor 32.
A pair of series connected, mutually exclusive switches 34 and 36 are coupled between the boost voltage which is impressed across the capacitor 32 and the common ground. Switches 34 and 36 cooperate as an inverter 13, chopping the DC boost voltage into a square wave having a frequency equal to that of the oscillator. Switch 34 has its unswitched terminal coupled to the junction of capacitor 32 and the cathode of diode 20. The switched terminal of switch 34 is coupled to the junction of the switched terminal of switch 36 and the first terminal of inductor 40. The unswitched terminal of switch 36 is coupled to the common ground. In the preferred embodiment, switches 34 and 36 are complementary field effect transistors (FETS) with ample voltage and current ratings to withstand the reactive loads. Those skilled in the art will recognize other expedients for switches 34 and 36 without departing from the scope of the present invention.
Switches 34 and 36 are controlled by oscillator 38 to chop the DC boost voltage developed across capacitor 32 at the frequency of oscillator 38. That is, switches 34 and 36 are opened and closed alternately to produce a substantially square wave of a frequency equal to the oscillator 38 across inductor 40 and capacitors 42 and 43. It has been determined through simulation and experimentation that the preferred chopping frequency ranges typically from 40-50 KHz during normal operation to 60-80 KHz at lamp start-up.
Inductor 40 and capacitor 42 together with capacitor 46 form an LC circuit which provides a high Q factor and matching impedance for starting the lamp. The lamp 44 may be of the type described in U.S. Pat. No. 4,862,035, herein incorporated by reference. The capacitor 43 provides DC isolation for the lamp circuit.
With reference to FIG. 2, the oscillator 38 oscillates at a frequency proportional to the capacitance of capacitor 48 and the resistance of resistor 50 (50A and 50B). Other expedients are known for oscillator 38, the exact configuration not being necessary for the understanding of the present invention. Oscillator 38 may be part of or included in PWM control circuitry 26. However, for clarity, FIG. 2 depicts oscillator 38 separately from PWM control circuitry. Zero crossing detector 54 has its inputs coupled across AC voltage 12 and its output coupled to an input on line 55 of one-shot multivibrator 56. Zero crossing detector 54 provides a relatively low frequency clock for determining the period of the one-shot 56. Many expedients are known for zero crossing detector 54, the exact configuration not being necessary for the understanding of the present invention. It is to be understood that oscillator 38 could also be divided down (depicted as phantom divider 57) and used as a clock for one-shot multivibrator 56 on line 55.
Upon power up, the power up enable circuit 52 enables or resets the one-shot 56 to be clocked by zero crossing detector 54 The power up enable circuit 52 resets the circuit upon power up. After one-shot multivibrator 56 is enabled, it is clocked by zero crossing detector 54 on the subsequent pulse on line 55. After the predetermined time set by one-shot 56 expires, it is disabled until power is recycled. The power up enable circuit 52 may optionally include a reset input, coupled to a reset switch 53, for optionally initiating the kickstart process without powering down AC voltage 12.
The output 59 of the one-shot multivibrator 56 has a dual purpose. First, it enables the switch 58 to insert resistor 50B in parallel with the resistor 50A thereby decreasing the effective resistance 50 and increasing the frequency of oscillator 38. Moreover, the output 59 of the one-shot 56 closes a switch 60 to insert resistor 30B in parallel with resistor 30A thereby decreasing the effective resistance 30. Decreasing the bottom leg of the resistive divider comprised of resistors 28 and 30 forces the boost voltage across capacitor 32 to increase as described herein.
The increase in applied frequency and boost voltage more readily ionizes the gas in lamp 44. It has been determined through experimentation and simulation that the preferred preselected boost interval for starting fluorescent lamps is between 1-4 seconds. Those skilled in the art will recognize with the aid of the present disclosure and without undue experimentation, other preferred times and values for resistors 30A, 30B and 50A, 50B for other types of gas discharge lamps.
Reference is made to FIG. 3 which depicts a more detailed view of the PWM control circuit 26 in FIG. 2. It should be understood that FIG. 3 only depicts the preferred embodiment and that other switched mode power PWM converters may be adapted for use as the PWM control circuit 26 without departing from the scope of the present invention. Exemplary, but not exclusive of another PWM control circuit 26 adaptable for use with the present invention, is the UC3842/UC3844 PWM circuit from the Unitrode Integrated Circuit Corporation of Merrimack, N.H.
With reference to FIG. 3, an error amplifier 62 has its inverting input coupled to the junction of resistors 28 and 30. It has a resistor 65 and capacitor 67 coupled between the inverting input and its output 63. Its non-inverting input is coupled to a reference voltage generator 61. The voltage generator 61 may be a zener diode or other suitable regulator. The reference voltage V REF is selected to be a voltage which is proportional to the boost voltage across capacitor 32 multiplied by the ratio of the voltage divider formed by resistors 28 and 30. For example, if V REF is set to 2.5 volts, the boost regulator would regulate the boost voltage across capacitor 32 to a value such that the voltage drop across resistor 30 would be substantially 2.5 volts. The output 63 of error amplifier 62 is coupled to the inverting input of current sense comparator 64. The non-inverting input of comparator 64 is coupled to the junction of switch 22 and resistor 24. The voltage drop across resistor 24 is proportional to the current flowing through inductor 18 of the boost regulator.
When the voltage drop across resistor 24 equals exceeds the output 63 of error amplifier 62, the comparator trips and resets flip flop 66 thus providing a signal to a first input of AND gate 68 for opening switch 22. The process is repeated on subsequent oscillator clock pulses wherein oscillator 38 sets flip flop 66 and comparator 64 resets it when the desired current is obtained. In this manner, a closed loop system is maintained to regulate the boost voltage. The inductor 18 is initially charged on each clock pulse of oscillator 38 until the sensed current equals the output of error amplifier 62. Since the oscillator 38 operates at a frequency many times higher than the AC line frequency, the inductor 18 charges and discharges hundreds of times during one cycle of the AC line. This provides substantially in-phase voltage and current to the lamp 44 load and a power factor of nearly unity.
The oscillator 38 is also coupled to a second input of AND gate 68. AND gate 68 is a protective measure requiring both the oscillator 38 and the output of flip flop 66 be high in order to energize switch 22. This feature ensures that if comparator 64 does not reset flip flop 66, then switch 22 will only be on for one-half the duty cycle of oscillator 38.
The foregoing description of the preferred embodiment of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teachings. It is intended that the scope of the invention be limited not by this detailed description but rather by the claims appended hereto. | A kickstart system and method for operating gas discharge lamps is disclosed wherein the amplitude and frequency of the starting voltage are raised for a predetermined period of time to ionize the gas within the lamp and thereafter reduced to steady state operating levels. | 8 |
FIELD OF THE INVENTION
[0001] The present invention generally relates to cooking ovens and, more particularly, to an improved cooking oven designed to operate at elevated pressures and temperatures.
BACKGROUND
[0002] The process of cooking of food generally involves raising the internal temperature of the food to a specified level. The higher the internal temperature is raised, the more “cooked” the food is. For example, raw meat at room (ambient) temperature starts off at approximately 70 degrees F. As the meat is heated the temperature of the meat rises. While temperatures vary depending on the type of meat, the consistency and the thickness, generally speaking, for rare meat, the internal temperature (temperature near the center) is approximately 120 to 130 degrees F. Meat in its medium state has an internal temperature of about 140 to 150 degrees F. Meat is deemed well done when the internal temperature is about 160° F. or more degrees F.
[0003] There are a variety of conventional methods for cooking foods, such as on top of a flame (grilling, pan frying) and in an oven (e.g., baking, broiling). In all methods, the same concept of raising the temperature of the product is the ultimate goal. How that is accomplished affects the taste and time involved in the cooking process.
[0004] There are three primary forms of heat transfer that occur in a cooking process. Conduction is direct heat flow through matter, such as the conduction of heat from the hot surface of a stove to a cooking pot, or from the surface of the food into the center of the food. More particularly, conduction is heat transfer by means of molecular agitation within a material (i.e., the vibration of the material's atoms) without any motion of the material as a whole. As such, the higher vibrating atoms transfer their increased energy to less energetic neighboring atoms. The result is no net motion of the solid as the energy propagates through the material. For example, if one end of a metal rod is heated to a higher temperature than the other end, energy will be transferred down the rod toward the colder end because the higher speed particles will collide with the slower ones with a net transfer of energy to the slower ones. For heat transfer between two surfaces, the rate of conduction heat transfer is:
[0000]
Q
t
=
κ
A
(
T
hot
-
T
cold
)
d
Equation
1
Where:
[0005] Q=heat transferred in time
[0006] κ=thermal conductivity of the barrier
[0007] A=area
[0008] T=temperature
[0009] d=thickness of barrier.
[0010] Gases transfer heat by direct collisions between molecules and, as would be expected, the thermal conductivity of a gas is low compared to most solids.
[0011] Convection is heat transfer by the motion of a heated fluid such as air or water when the heated fluid is caused to move away from the source of heat, carrying energy with it. The heat travels upward with the natural upward movement of air. Convection above a hot surface occurs because the surface heats the air adjacent to it. As the air heats up, it expands becoming less dense, and rising.
[0012] Convection can also lead to circulation of a fluid. For example, as a pot of water is heated over a flame, the heated water expands and becomes more buoyant. Cooler, more dense water near the surface descends and patterns of circulation form. By controlling the circulation of the heated fluid it is possible to maximize heating or cooling of a particular location. In an oven, by controlling the flow of heated air, it is possible to maximize the heating of an item within the oven.
[0013] Radiation is the third form of heat transfer and is the transmission of electromagnetic rays through space. These rays have no temperature, only energy. Every material or object with a temperature above absolute zero emits these rays.
[0014] In a conventional oven the food is located spaced apart from the heat source. Air separates the food from the heat source. As such the heating process in a conventional oven involves radiation (from the heating source to the food), conduction (from the surface of the food toward the center of the food), and to a lesser degree convection (due to the naturally occurring heat flow in the oven.)
[0015] A convection oven operates in a slightly different manner than a conventional oven. In a convection oven, a fan mounted within the oven produces circulation of the heated air within the oven. The fan circulates the air rapidly through the cooking chamber. This circulation of air has two principal effects. First, it causes the temperatures throughout the oven to be almost exactly equal. In a conventional oven, differences in temperature typically occur that can lead to uneven cooking and could require that the food be placed in specific areas within the oven to make sure that the food cooks properly. Convention ovens eliminate this problem. Second, a convection oven transfers heat more evenly to the food. The movement of the hot air past the food prevents regions of colder air from building up near the surfaces of cool foods. As such, the food in a convection oven heats and cooks faster.
[0016] Also, since the heated air is forced past the food, a convection oven can operate at a lower temperature than a standard conventional oven and still cook food more quickly. Generally, with a convection oven there will be about a 25% reduction in cooking temperature and a 20% reduction in cooking time, compared to a conventional oven.
[0017] There also tends to be less shrinkage with a convection oven, and, because the heat is forced to circulate in the oven, a convection oven can be filled as long as about an inch of space is left for the air to circulate between the food and the oven walls.
[0018] In recent years, microwave ovens have become commonplace in the household. A microwave oven uses microwaves to heat food. Microwaves are radio waves. In the case of microwave ovens, the commonly used radio wave frequency is roughly 2,500 megahertz (2.5 gigahertz). Radio waves in this frequency range have an interesting property: they are absorbed by water, fats and sugars. When they are absorbed they are converted directly into atomic motion—heat. Microwaves in this frequency range have another interesting property: they are not absorbed by most plastics, glass or ceramics.
[0019] In a conventional oven, the heat migrates (by conduction) from the outside of the food toward the middle. You also have dry, hot air on the outside of the food evaporating moisture on the surface of the food. As such, the surface dries out, becoming crispy and brown, while the inside stays moist.
[0020] In microwave cooking, the radio waves penetrate the food and excite water and fat molecules pretty much more evenly throughout the food. No heat conduction toward the interior occurs. There is heat everywhere all at once because the molecules are all excited together. However, there are drawbacks to microwave cooking. The radio waves penetrate unevenly in thick pieces of food and, as such, they don't make it all the way to the middle, and “hot spots” can be caused by wave interference.
[0021] Another method of cooking involves the use of a pressure cooker. These are pots for cooking food that are designed to maintain a pressure above atmospheric pressure. They consist of an enclosed pot that is placed on top of a stove file. Water in an open pot boils at 212 degrees F. at a standard atmosphere. No matter how long you continue to boil the water, it will stay at the same temperature. As the water evaporates and becomes steam it is also the same temperature, 212 degrees F. The only way to make the steam hotter (and/or to boil the water at a higher temperature) is to increase the pressure. This is what a pressure cooker does. The heat from the stovetop transfers through the metal pot to the contents (which generally include water and the items being cooked.) Since the pressure cooker is sealed, as the water inside the container expands to steam, the closed environment of the container causes the pressure inside the container to rise. The higher pressure, in turn, results in a higher temperature inside the vessel.
[0022] The laws of physics hold that, as long as pressure is uniform on all surfaces of an object, the object will not distort. In a pressure cooker, the pressure is effective throughout the food, from the surface through to the center. Thus, the increased pressure will not crush the food in the cooker.
[0023] At 15 psi, the temperature that water boils is about 250 degrees F., instead of 212 degrees F. The increased pressure inside the pot delays the water and/or other liquids inside the pot from boiling until the liquid reaches a much higher temperature. As a result, the cooking process is sped up considerably.
[0024] Air is a poor conductor of heat; but water is a good conductor. Steam, due to its water content, has approximately six times the heat potential than dry air when it condenses on a cooler food product. This increased heat transfer potential makes steam a much more effective cooking medium. Steam is efficient in transferring cooking heat rapidly to foods upon contact without burning or damaging the final product, and for less energy.
[0025] Generally, pressure cookers generate pressures from 5 to 15 psi. The main drawback to a pressure cooker is that the temperature inside the pressure cooker is limited to the boiling point of the water (i.e., 250 degrees F. at 15 psi). As such, the speed of cooking is also limited to this temperature. Table 1 lists the temperatures inside a pressure for various pressures.
[0000]
TABLE 1
Pressure Inside
Cooking Temperature
The Pressure Cooker
212° F. (100° C.)
0 psi
220° F. (104° C.)
5 psi
235° F. (113° C.)
10 psi
250° F. (121° C.)
15 psi
[0026] As meat cooks, the muscle fibers shorten in both length and width. As a result, the juices in the meat are eventually squeezed out. Thus, the longer a food cooks the drier it becomes.
[0027] For cooking purposes, meat consists of lean tissue, proteins, collagen and 75% water. Collagen exists in flesh, bone and connective tissue, and is very important to the cook because the amount of collagen in a piece of meat will determine the length of time it should be cooked. Therefore, the higher the level of connective tissue, the longer the meat will need to be cooked. Weight-bearing muscles and muscles that are constantly used contain higher amounts of collagen than muscles that aren't used for support or aren't used as frequently.
[0028] A number of different things happen as a food cooks, especially meats and poultry. At about 104 degrees F., the proteins in meat start to denature. At about 122 degrees F., the collagen begins to contract. At about 131 degrees F., the collagen starts to soften. At about 160 degrees F., the meat no longer holds oxygen and turns gray. Finally, at about 212 degrees F., the water in the meat begins to evaporate into steam, drying out the meat.
[0029] A turkey is considered cooked when the temperature inside the thickest part of the turkey is approximately 185 degrees F. Table 2 lists the approximate cooking times for a turkey at 325 degrees F.
[0000]
TABLE 2
Cooking times for a turkey at 325 degrees F.
Weight
Unstuffed
Stuffed
8 to 10 pounds
2¾-3
hours
3-3½
hours
12 to 14 pounds
3-3¾
hours
3½-4
hours
14 to 18 pounds
3¾-4¼
hours
4-4¼
hours
18 to 20 pounds
4¼-4½
hours
4¼-4¾
hours
20 to 24 pounds
4½-5
hours
4¾- 5¼
hours
[0030] As is evident from Table 2, the time to cook a turkey is significant. To date, no method has been introduced to speed the process along. Pressurized cooking has not been a viable option given the small size of the pot and the limited cooking temperature.
[0031] A need exists for an improved oven for cooking food products.
SUMMARY OF THE INVENTION
[0032] The present invention relates to a pressurized oven system that includes an oven enclosure having front, back, top, bottom and side walls. A door is hingedly attached to one of the walls for sealing an opening in the walls. A heating system is connected to the enclosure for generating heat in the enclosure. The heating system may be a gas or electric heating system configured to heat the interior of the oven enclosure.
[0033] A pressure source is connected to the enclosure for supplying a pressurized fluid into the enclosure in order to create an atmosphere inside the enclosure that is above atmospheric pressure.
[0034] The oven system also includes a control system with at least one pressure sensor and at least one temperature sensor for monitoring and controlling the temperature and pressure within the enclosure.
[0035] The pressure source may be an external gas supply for supplying pressurized air into the oven, preferably between about 0 and about 25 psi.
[0036] The oven system may also include a liquid conduit for channeling a liquid into the enclosure to increase the moisture content within the enclosure during cooking.
[0037] In one embodiment, the system includes an enclosure connected to the oven for generating a gaseous smoke for feeding into the oven enclosure.
[0038] A process is also disclosed for cooking a food item in an oven. The process involves generating heat within the oven; creating pressure within the oven enclosure above atmospheric pressure during at least a portion of the cooking process; maintaining the pressure within the oven enclosure during at least a portion of the heating process; and controlling the heating and pressure during the cooking process.
[0039] The process optionally involves creating a moist environment within the oven enclosure, such as by supplying a liquid into the enclosure. The process may also optionally include the step of creating an acidic environment within the oven enclosure, such as with the supply of a smoke and carbon dioxide.
[0040] The foregoing and other features of the invention and advantages of the present invention will become more apparent in light of the following detailed description of the preferred embodiments, as illustrated in the accompanying figures. As will be realized, the invention is capable of modifications in various respects, all without departing from the invention. Accordingly, the drawings and the description are to be regarded as illustrative in nature, and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] For the purpose of illustrating the invention, the drawings show forms of the invention which are presently preferred; it being understood, however, that the invention is not limited to the precise arrangement and instrumentality shown.
[0042] FIG. 1 is an isometric view taken from the rear of an oven assembly according to one embodiment of the invention.
[0043] FIG. 2 is an isometric view taken from the front of the oven assembly of FIG. 1 .
[0044] FIG. 3 is a rear view of the oven assembly of FIG. 1 .
[0045] FIG. 4 is a side view of the oven assembly of FIG. 1 .
[0046] FIG. 5 is a front view of the oven assembly of FIG. 1 .
[0047] FIG. 6 is a top view of the oven assembly of FIG. 1 .
[0048] FIG. 7 is an isometric view taken from the front of an oven according to a second embodiment of the invention.
[0049] FIG. 8 is a front view of the oven of FIG. 7 .
[0050] FIGS. 9A-9D illustrate another embodiment of a door for use in the present invention in various stages of closing.
[0051] FIGS. 10A-10D illustrate side views of the door of FIGS. 9A-9D in the various stages of closing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0052] Referring to the figures wherein like reference numerals illustrate similar components, two embodiments of the invention are shown that are presently preferred. It would be readily apparent to those skilled in the art that a variety of modifications are possible within the scope of the present invention. The present invention is directed toward an improved cooking apparatus and associated method or process for cooking food stuffs. More particularly, the present invention, in one configuration, is directed to a pressurized oven 10 .
[0053] FIG. 1 illustrates an isometric view of one embodiment of the oven 10 according to invention. The oven 10 generally includes a multisided, preferably five sided, walled oven enclosure 12 with an opening 14 . A door 16 is provided that is designed to close off the opening 14 . As will be discussed in more detail below, the door 16 is designed to seal the opening so as to prevent or inhibit heat and gases from passing out of the opening 14 when the door 16 is open. It should be readily apparent that the enclosure may be made so as to have any convenient shape and preferably includes an outer cabinet (not shown for simplicity of discussion.)
[0054] The oven enclosure 12 is preferably made from conventional materials, such as steel, and configured to withstand pressures in excess of ambient. More preferably, the oven enclosure walls 12 are designed to withstand pressures greater than 5 psi and more preferably greater than 20 psi. The present invention contemplates that the oven will be subjected to internal pressures ranging between 0 psi and 20 psi during most cooking cycles, but the present invention is not limited to those pressures and, depending on the food it is designed to be used to cook, can be constructed so as to withstand pressures higher that 20 psi during use. The walls of the oven enclosure 12 are, thus, preferably designed to withstand the likely highest pressures that the particular oven is intended to be used for. Suitable walls may be constructed, for example, through the use of steel plates reinforced by an enclosure support frame.
[0055] In one embodiment, the oven enclosure 12 is mounted to a frame 18 designed to support the oven enclosure 12 . In the illustrated embodiment of FIG. 1 , the frame 18 maintains the oven enclosure 12 at a suitable height off the floor so as to position the opening 14 at an appropriate height for use. As will be discussed in more detail below, various pieces of equipment may be located beneath the enclosure or, if desired, placed above or behind the enclosure 12 . Although the embodiment of FIGS. 1-6 position the oven off the floor, it is also contemplated that that oven enclosure 12 may be mountable to a pre-existing frame, such as in a wall of a home, or may be configured to sit on a countertop.
[0056] A seal 20 is located between the door 16 and the edge of the enclosure 12 that surrounds the opening 14 . The seal 20 is preferably designed to be substantially air tight so as to prevent or minimize pressure loss from the oven when the door 16 is closed and the oven is operational. In addition, the seal 20 should tolerate the anticipated temperatures. The seal 20 may be mounted to the door 18 or the enclosure 12 . The seal may be pressurized to a higher pressure than the pressures anticipated inside the oven.
[0057] The door 16 may include a window 19 , such as tempered glass, so as to permit the user to view the food item during the cooking process. A light (not shown) may also be mounted so as to provide illumination of the food item during cooking.
[0058] A pressure source 22 is connected to the oven enclosure 12 . Preferably the pressure source 22 is mounted to the frame 18 , although it is also anticipated that the pressure source can be external from the oven 10 and connected through suitable conduits. In one exemplary embodiment, the pressure source 22 is a high pressure air or gas compressor capable of supplying pressurized air between 0 and 25 psi. One or more gas supply conduits 24 connect the pressure source 22 to the oven enclosure 12 . In the illustrated embodiment of FIGS. 2 and 3 , the gas supply conduit 24 connects to the side of the enclosure 12 at a location near the top. This location permits the pressurized air to flow into oven enclosure 12 and circulate around the enclosure. Other mounting locations are also envisioned. For example, the gas supply conduit 24 could be mounted to the bottom or top and a deflector or baffle could be positioned adjacent to the conduit end so as to deflect the incoming pressurized gas in a preferred or desirable direction. Generally, the design should refrain from channeling the gas directly toward the area where the food is placed. If more than one gas supply conduit is used, they may be located on opposite sides of the enclosure 12 .
[0059] A pressure sensor 26 is mounted within the enclosure 12 and connected to a pressure gauge 28 mounted on the enclosure 12 or the frame 18 . The pressure sensor 26 monitors the pressure within the enclosure 12 and provides a reading on the pressure gauge 28 . The pressure gauge may be analog or digital.
[0060] The oven includes a heating system 30 . Any conventional heating system, such a an electric or gas heater, may be used. In one embodiment, the heating system 30 is an electric heating system that includes one or more electric burners or heating coils or rods 32 mounted within the enclosure 12 . Preferably the electric coils are positioned along the bottom with a suitable deflector or mesh screen (not shown). In an electric heating system, the oven would preferably include an electric supply (not shown) for connecting to an electric power source. A control system would control the flow of the electric power to the coil. In one embodiment of the invention, the oven includes eight 1000 Watt heating rods and two 1500 Watt heating rods. To efficiently control the heat generation in the oven, the bottom may be insulated, such as with a ceramic sheets, thermal insulation or fiber board.
[0061] In an alternative embodiment, the heating system can be a gas heating system that includes gas burners positioned along the bottom of the enclosure and a deflector for providing more efficient heat distribution, similar to conventional oven arrangements. A gas heating conduit would be used to supply natural gas from a natural gas source. An ignition system, such as a pilot light or electric igniter, would be incorporated for igniting the natural gas, as is common in the art.
[0062] In addition to, or as an alternate for, the gas or electric heating systems, the present invention may include a radiant heating system. Radiant heaters are generally known, and can be incorporated into the heating system so as to provide a mechanism for crisping the external surface of the food product being cooked.
[0063] A smoker assembly 34 may be incorporated into the system to provide optional flavor enhancement during cooking. In the illustrated embodiment, the smoker assembly 34 includes a smoke box 36 with an access door 38 . The access door is preferably hinged to the box 36 so that the operator can easily open the door 38 to feed suitable smoking products, like mesquite wood. The smoker box includes a burner assembly (not shown), such as a heating coil (electric) or natural gas burner, similar to the oven above, to heat the chips or wood. The smoker assembly 34 is preferably similar to conventional smoker assemblies attached to gas grills except that the smoker is pressurized. That is, an external pressure source, preferably the same pressure source as the oven, pressurizes the smoker box. A smoker conduit 40 connects the smoker box 36 to the interior of the oven enclosure 12 . A one way valve is preferably located on the conduit line and prevents backpressure into the smoker box from the oven. As long as the pressure within the smoker box is greater than the pressure in the oven, the smoke from the box will flow into the oven.
[0064] Other methods can be used for channeling the smoke into the oven, such as a venturi line connected to the gas supply conduits 24 allowing the pressurized gas flowing into the oven to draw the smoke from the smoke box into the over enclosure. It is also contemplated that the smoker box may be sealed such that the heating of the air within the smoker box will naturally cause the pressure within the box to increase. Once the pressure is above a threshold amount, such as greater than the pressure in the oven, the smoke will channel into the oven enclosure from the smoker box.
[0065] As shown in FIG. 5 , the heating system 30 also includes an oven temperature monitor 41 to detect the temperature of the inside of the oven. The oven temperature monitor preferably includes an oven temperature sensor 42 positioned within the enclosure 12 , and a display or gauge 44 preferably located outside the enclosure. The oven temperature monitor may be a conventional analog thermometer designed to operate within the anticipated temperature ranges and pressures. More preferably, the oven temperature monitor 41 is digital with a digital signal from the temperature sensor being displayed as a temperature value on the display 44 . Oven temperature sensors, displays and monitors are well know in the art and, therefore, no further discussion is necessary.
[0066] The heating system 30 also preferably includes a food temperature monitor 45 to detect and monitor the temperature of the food. The food temperature monitor preferably includes a food temperature sensor 46 positioned within the enclosure 12 and which may be a conventional temperature probe designed to be inserted into the food product. A display or gauge 48 is preferably located outside the enclosure. The food temperature monitor may be a conventional analog thermometer designed to operate within the anticipated temperature ranges and pressures. More preferably, the food temperature monitor is preferably a digital device that receives a digital signal from the food temperature sensor and displays it as a temperature value on the display 48 . Food temperature sensors, displays and monitors are well know in the art and, therefore, no further discussion is necessary.
[0067] An electronic controller 300 is used to control the supply of pressurized gas. The controller 300 is adapted to receive, for example, a variety of information, preferably including signals indicative of the pressure inside the enclosure from the pressure sensor 26 , the temperature inside the enclosure from the oven temperature sensor 42 , the temperature of the product being cooked from the food temperature sensor 46 . The electronic controller 300 is preferably configured to control one or more features and/or components of the oven. For example, the controller 300 is preferably connected to the pressure source 22 and/or the gas supply conduit 24 for controlling supply of the pressurized gas to the enclosure 12 . In such an embodiment, if the controller 300 senses that the pressure within the enclosure is below a desired value, the controller 300 controls a valve for supplying the pressurized gas along the gas supply conduit 24 until the pressure within the enclosure is above a desired level. Alternately, the controller could activate the pressure source 22 to begin to further pressurize the gas that is supplied.
[0068] If the oven includes a smoker assembly as discussed above, the controller 300 can be used to separately control the smoker.
[0069] The controller 300 could also activate an alarm if a prescribed time frame has completed (e.g., cooking cycle) or if a pressure exceeds a desired value.
[0070] The controller 300 may also include a memory for storing various prescribed cooking procedures, and a selection device, such as a touch screen, buttons, keyboard or other mechanism for allowing an operator to program, store, and/or select a cooking procedure. Other uses and configurations for the controller will be explained below. A variety of controllers exist that can be configured to provide the necessary functionality described herein, including controllers using hardware, software or firmware components. The selection device may be physically attached to the controller or may be a separate component such as a remote control unit. It is also contemplated that the controller could be connected to a wireless or wired network (either directly or through the internet) so that remote programming and monitoring of the controller, and hence the oven, is possible using a standard general purpose computer or a dedicated computer device. As such, as series of ovens in a cooking facility can be monitored and controlled through a single computer system.
[0071] A temperature limiter can be included to prevent over heating of the oven. The limiter can be fixed, such as a absolute maximum temperature, or could be adjustable, such as a maximum temperature for the particular food being cooked.
[0072] Although the controller 300 has been described as being separate from the gauges and controls for the heating system, it is also contemplated that features of the heating controls, such as the gauges, can be part of the controller 300 , or that the heating controls, including the displays, and monitoring and control functionality can be provided through a software based system that operates through a display screen mounted to or separate from the oven.
[0073] In order to permit the temperature to increase within the oven, one or more vents (not shown) are formed in the oven, preferably in the top on either side for the oven, and adapted to channel gas (air) out of the oven. The location of the vents provides for some controlled flow inside the oven. It should be readily apparent that the venting and/or pressurizing of the oven should be designed and/or controlled so that, during cooking, the volume of gas (air) being channeled into the oven is preferably equal to or greater than the volume of gas (air) being vented so that the gas (air) pressure within the oven increases. The controller 300 can control the pressure into and out of the oven so as to provide for the proper pressurization of the oven.
[0074] Referring to FIG. 1 , the door 16 may be attached to the oven enclosure 12 in any convention manner. One preferred door hinge assembly 100 is illustrated in the drawings for attaching the door 16 to the frame 18 . In this embodiment, the door hinge assembly 100 is designed to pivot the door up and away from the opening of the enclosure. The door hinge assembly 100 includes two sets of upper and lower support arms 102 , 103 , each set being rigidly attached to the top and bottom of a side of the door 16 . The opposite end of each upper support arm 102 is pivotally attached to one leg of an upper dogleg link 104 . The upper dogleg link 104 is attached to an upper crossbar 105 at a point between its ends. The upper crossbar 105 preferably connects to both upper doglegs 104 and is support by a bracket on the frame 18 so as to permit the dogleg to pivot with respect to the frame 18 .
[0075] The second end of each dogleg link 104 is attached to an upper end of a first piston assembly 106 . The piston assembly 106 may be a hydraulic or pneumatic piston. The lower end of each piston assembly 106 is attached to a first end of a lower dogleg link 108 . The lower dogleg link 108 is attached to lower crossbar 110 at a point between its ends. The lower crossbar 110 preferably connects to both of the lower doglegs 108 and is support by a bracket on the frame 18 so as to permit the lower doglegs 108 to pivot with respect to the frame 18 .
[0076] A bracket 112 is fixedly attached to the end of the upper support arm 102 and pivotally attached to one end of a first control arm 114 . The opposite end of the first control arm 114 is pivotally connected to a second control arm 116 . The second control arm 116 is pivotally mounted to a bracket on the frame 18 between the ends of the second control arm 116 . The second end of the second control arm 116 is pinned to preferably two struts or dampers 118 , 120 which, in turn, are pinned to brackets on the bottom of the frame. These struts control the pivotal motion of the second control arm 116 about its pivotal mount to the frame 18 .
[0077] The combination of the upper support arm 102 , the upper dogleg 104 , the piston assembly 106 and the lower dogleg 108 control the motion of the top of the door 16 toward and away from the enclosure. More particularly, in light of the increased pressure and temperature that is created in to over, the door attachment assembly is designed to move the top of the door 16 away from the enclosure about ½ to 1 inch in order to vent the heat and gas from the oven prior to the door opening completely.
[0078] The combination of the upper support arm 102 , the first control arm 144 , the second control arm 116 and the struts 118 , 120 control the lifting and rotation of the door 16 . Thus, after the top of the door 16 has shifted away from the enclosure to vent the oven, this second combination of elements rotates the door away from the enclosure into the position shown in the figures.
[0079] A control piston 122 is connected to the upper control arm 105 through a center dogleg link 124 and designed to rotate the upper control arm 105 . Rotation of the upper control arm controls the rotation of the upper doglegs 104 which, in turn, control the swiveling of the door between the open and closed positions.
[0080] The piston 106 , 122 are connected to a switch which controls the operation of the pistons and, thus, the opening and closing of the door 16 . The switch is preferably part of the controller 300 .
[0081] The lower support arms 103 preferably include a notch 126 designed to engage with a pin 128 extending out from the frame so as to secure the lower support arms to the frame when the door is closed.
[0082] While one preferred embodiment of the door hinge assembly is shown in the drawings, it would be readily apparent to those skilled in the art to provide alternate door hinge assemblies, in light of the discussion above. For example, the door can be attached to the frame through a simple hinge and a lock provided that secures the door to the frame so as to prevent the internal pressure from forcing the door open.
[0083] The increased pressure and higher temperature in the oven creates a denser atmosphere in the enclosure. The denser atmosphere allows for radiated energy from the heating source to reach the surface of the food quicker. The denser air acts like a solid material, resulting in a form of conduction through the gas. Preferably water is added to the gas or channeled into the oven so as to result in a steam being generated within the enclosure. This moist atmosphere produces a moisturizing of the food being cooked, thus preventing the food from drying out during cooking. A separate water supply may be attached to the oven and a conduit provided to supply the water into the oven in the form of a mist (such as with a diffuser) or injected into the gas stream flowing into the oven. Alternately, the natural water content of the food will assist in creating the steam environment.
[0084] The applicant has determined that the skin of poultry is semi-permeable. Hence, the browning of the skin on poultry would tend to prevents permeation of moisture into the food. However, in the present oven, the increased pressure forces the moisture through the skin into the meat product, thus increasing the moisture content of poultry over conventional ovens.
[0085] The addition of the smoke to the cooking process makes the air inside the oven more acidic. That is, the smoke changes the water molecules in the air to an acid which provides a unique and beneficial cooking environment. For example, the pressurized gas and liquid systems discussed above can be used to create a gaseous (gas-liquid) cooking marinade that is directed into the oven. In one embodiment, CO 2 can be added to water (or added to a moist environment within the oven enclosure) and combined with smoke from the smoker to create a carbonic acid within the enclosure. The carbonic acid will penetrate into the meat and tenderize the meat. The acid tends to breakdown tendons and other tough features of meat and poultry. The pressure assists in forcing the additional gas element into the water.
[0086] The increased pressure of the gas within the oven allows for additional moisture to be added since the saturation level of the gas is generally higher at a higher temperature and pressure than at a lower pressure and temperature. As such, the oven permits more moisture than a conventional oven. Also, generally at higher temperature, air alone will have a lower density. So the addition of pressure into the oven raises the density of the air above where it would be in a conventional oven. For example, Table 3 shows the effect that temperature and pressure have on air.
[0000]
TABLE 3
Density of Air (lb/ft 3 ) at Different Temperatures
Air Temp.
Gauge Pressure (psi)
(° F.)
0
5
10
20
30
30
0.081
0.109
0.136
0.192
0.247
40
0.080
0.107
0.134
0.188
0.242
50
0.078
0.105
0.131
0.185
0.238
60
0.076
0.102
0.128
0.180
0.232
70
0.075
0.101
0.126
0.177
0.228
80
0.074
0.099
0.124
0.174
0.224
90
0.072
0.097
0.121
0.171
0.220
100
0.071
0.095
0.119
0.168
0.216
120
0.069
0.092
0.115
0.162
0.208
140
0.066
0.089
0.111
0.156
0.201
150
0.065
0.087
0.109
0.154
0.198
200
0.060
0.081
0.101
0.142
0.183
250
0.056
0.075
0.094
0.132
0.170
300
0.052
0.070
0.088
0.123
0.159
400
0.046
0.062
0.078
0.109
0.141
500
0.041
0.056
0.070
0.098
0.126
600
0.038
0.050
0.063
0.089
0.114
[0087] One test was conducted using the oven described above. In the test, the oven was operated at 425 degrees and pressurized from 16-17.5 psi. The result was that a 16 pound turkey cooked completely in 50 minutes and remained very moist. This compares with a conventional oven which takes approximately 3½ A hours to cook the same size turkey.
[0088] The oven illustrated in FIGS. 1-6 is configured as a large commercial oven. A smaller version has been designed for residential use. FIGS. 7 and 8 illustrate such as design. The components described above of the oven would preferably be mounted on the side and back of the oven enclosure within the cabinet. This design provides a more compact version of the oven. Most of the components described above with respect to the first embodiment of the invention would be included in the embodiment shown in FIGS. 7 and 8 , and are depicted with the same reference numerals.
[0089] Referring to FIGS. 9A-9D illustrate an alternate embodiment of a door 400 for use in the pressurized oven system. Since the pressure in the oven tends to push the oven door outward, typical doors that pressure inward to seal are constantly fighting the pressure inside the oven. In an alternate concept, a unique door is disclosed that uses an inner door wall that, when the door is in its closed position, is located inside the door frame on the front wall such that pressure inside the oven forces the inner door wall against the door frame, providing a strong seal.
[0090] As shown in FIG. 9A , in this embodiment, the door frame or opening 402 is not square or rectangular. Instead, it has a trapezoidal shape, with the top 402 T of the frame having a width that is less than the bottom 402 B of the frame and the sides 402 S tapering inward as shown. The door 400 includes an outer wall 404 and an inner wall 406 . The outer wall can have a conventional appearance, and is hinged to the oven near the bottom 402 B of the door frame. The inner wall 406 has a trapezoidal shape that is the same as the door frame only slightly larger. The inner wall 406 is mounted to the outer wall 404 through a linkage or articulation mechanism 408 that permits the inner wall to move parallel to the outer wall. The linkage 408 includes a handle 410 that passes through the outer wall to the inner wall.
[0091] As FIGS. 9A-9D , and 10 A- 10 D illustrate, the inner door is mounted to the outer door such that when the outer door is placed against the oven, the inner door is positioned slightly downward from the door frame 402 . This permits the inner wall to pass through the door frame opening. Once the outer door 404 is against the front door frame 402 as shown in FIGS. 9C and 10C , the handle 410 is pivoted from an unlocked position (shown in FIGS. 9C and 10C as extending outward) to a locked position shown in FIGS. 9D and 10D .
[0092] More particularly, the linkage mechanism includes, in one embodiment, two upper links 412 and two lower links 414 near the sides of the inner door 406 . Each link is attached at each end to the inner door and outer door through a pivot connection (such as a pinned connection). Thus, the linkages and the inner and outer doors form, in essence a four bar linkage system for controlling movement of the inner door relative to the outer door. As the outer door 406 is transitioned from the open position ( FIGS. 9A and 10A ) through the closed, but unlocked position ( FIGS. 9C and 10C ), the linkage mechanism 408 maintains the inner door in its unlocked position. As the handle 410 is engaged (pulled downward in FIGS. 9D and 10D ), the linkage causes the inner door to slide upward and slightly outward against the inside surface of the door frame, thus placing the door in its locked position.
[0093] Those skilled in the art will recognize in light of the above discussion that there are other ways to form the door and locking mechanism and, thus, the present invention is not limited to the particular configuration disclosed.
[0094] As discussed above, moisture created inside the oven can be used to enhance the cooking of the food. For example, spices and other flavor enhancers, can be placed on the item to be cooked in a dry state. During the heating process, the moisture in the oven enclosure can be controlled to cause the spices to form a marinate as the drain off into the cooking pan. The controller can be used to monitor the moisture content within the oven and in the food product using a humidistat or other conventional sensor.
[0095] Variations, modifications and other implementations of what is described herein will occur to those of ordinary skill in the art without departing from the spirit and scope of the invention. Accordingly, the invention is in no way limited by the preceding illustrative description. | A pressurized cooking oven system is disclosed that includes an oven enclosure having front, back, top, bottom and side walls. A door is hingedly attached to one of the walls for sealing an opening in the walls. A heating system is connected to the enclosure for generating heat in the enclosure. The heating system may be a gas or electric heating system. A process is also disclosed for cooking a food item in an oven. The process involves generating heat within the oven; creating pressure within the oven enclosure above atmospheric pressure during at least a portion of the cooking process; maintaining the pressure within the oven enclosure during at least a portion of the heating process; and controlling the heating and pressure during the cooking process. | 5 |
TECHNICAL FIELD
This invention relates to welding apparatus which shields the site of the weld with an inert gas to prevent oxidation and other reactions with atmospheric gases. One particular type of welding facilitated by this apparatus is automatic gas tungsten arc welding.
BACKGROUND ART
Inert gas shielded arc welding is known, and several prior patents teach apparatus for carrying out such welding. For example U.S. Pat. No. 4,599,505 (Lukens et al.) shows a gas shield with a skirted inert gas head. The head has an elongated trailing end and an electrode receiving port which is offset toward the leading edge of the head. The inert gas conduit within the head is perforated on the side away from the lens and releases the inert gas through the perforations. The head is packed with metal wool to aid diffusion of the inert gas. The head is generally hemicylindrical. The Luken et al. patent was issued on Jul. 8, 1986.
Other patents which may be pertinent are U.S. Pat. Nos. 3,521,023 (Dahlman); 4,300,034 (Schneider); 4,567,343 (Sullivan); and 4,625,095 (Das).
A problem in the art has been how to use inert gas shielded arc welding to build up the metal on a workpiece, such as a jet engine turbine rotor, along a circumferential work surface which lies under a parallel overhang of the workpiece and thus is only accessible from the side. Commercially available automated welding systems have their torch heads and inert gas skirts rigidly mounted in line with a conduit through which inert gas is introduced to the workpiece. Such a torch must be advanced to a work surface perpendicularly and receive inert gas through a supply conduit disposed perpendicularly with respect to the workpiece. The overhang of a turbine rotor will not permit such a torch to advance to the circumferential work surface in the proper alignment for welding.
SUMMARY OF THE INVENTION
Accordingly, one object of my invention is an inert gas shielded torch which can work effectively when inserted in the confined space under an overhang of a workpiece.
A related object of my invention is an inert gas shield which can receive its supplies of inert gas, weld metal, and electricity from the side and still provide an adequate envelope of inert gas around the weld site.
An additional object of my invention is an inert gas shield comprising a plenum and a gas lens which are positioned to minimize the amount of ambient air drawn toward the weld site by the flow of inert gas through the gas lens.
Another object of my invention is inert gas shielded welding apparatus in which the inert gas shield is teardrop-shaped to provide a sufficient flow of gas to the trailing end for effective shielding even though the trailing end of the plenum is more remote from the source of inert gas than the leading end.
Another object of my invention is an inert gas shield which has a low profile to fit beneath an overhang which closely overlies the portion of the workpiece to be welded.
Still another object of my invention is an inert gas shield which has a single inert gas supply conduit, yet provides a substantially uniform flow of shield gas from all parts of its gas lens.
Still another object of my invention is a torch which combines the functions of a gas shield and an electrical contact for gas shielded arc welding, and which has the advantages mentioned above for the gas shield per se.
These and other objects of my invention will become apparent from the present drawings and specification.
In accordance with these objects, one aspect of my improved apparatus for inert gas shielded arc welding is a gas shield including a skirted plenum, an outlet defined by the skirt, means to admit a supply of inert gas into the plenum, and at least one gas lens which has its outer margin overlying the lip of the skirt. This construction prevents air surrounding the skirt from being entrained in the inert gas passed through the outlet.
A second aspect of the invention is apparatus of the type generally described above for welding a part which is moving from a leading position to a trailing position relative to the gas shield. This apparatus has a skirted plenum which is placed adjacent to the weld site. The plenum is teardrop-shaped, having a leading wall, a trailing wall, and opposed side walls which converge toward the trailing end. The inert gas is preferably introduced nearer to the leading end than to the trailing end of the plenum. This construction allows inert gas to be directed to the site of welding near the leading end, while maintaining an adequate flow of inert gas to the more remote trailing end of the plenum which shields the weld after welding is complete.
Still another aspect of the invention is inert gas shielding apparatus which is fed with a stream of inert gas initially traveling parallel to the gas lens and to the surface being welded. The plenum and gas lens of the gas shield redirect the inert gas so it flows perpendicularly to the surface being welded.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a side elevation of an inert gas welding torch according to the present invention, showing a portion of a turbine rotor as a workpiece which is being built up using the torch.
FIG. 2 is a sectional view taken along line 2--2 of FIG. 1, enlarged to show greater detail.
FIG. 3 is a bottom plan view of the torch head, partially cut away to show the gas lens construction.
FIG. 4 is an isolated circumferential section of the torch according to the present invention, taken along line 4--4 of FIG. 1.
FIG. 5 is an enlarged fragmentary sectional detail view of an inert gas shield and gas lens assembly of the prior art.
FIG. 6 is a view like FIG. 5 of the corresponding structure according to the present invention.
FIG. 7 is a schematic view similar to FIG. 2, showing the drive means for the workpiece.
DETAILED DESCRIPTION OF THE INVENTION
While my invention will be described in connection with a preferred embodiment, it will be understood that I do not intend to limit the invention to that embodiment. On the contrary, I intend to cover all alternatives, modifications and equivalents within the spirit and scope of the invention as defined by the appended claims.
With reference primarily to FIG. 2, the torch generally indicated at 10 comprises a gas shield 12 including a peripheral skirt 14. The skirt 14 defines a plenum generally indicated at 16. The skirt 14 terminates in a lip 18 defining an outlet generally indicated at 20 which is covered by an outer gas lens 22 and an inner gas lens 24. Each gas lens is a fine wire mesh screen made of 300 Series stainless steel, and is about 1/16 inch (1.6 mm) thick. The gas lenses 22 and 24 collimate the inert gas to some degree so it passes through the outlet 20 substantially perpendicularly to the welded surface 26 of the workpiece 28. The gas lenses also tend to equalize the head of pressure in different regions of the plenum.
In a preferred aspect of the invention, a tungsten or other refractory metal electrode 30 is fixed with respect to, and projects through, the outlet 20 and gas lenses 22 and 24 to supply welding current to the welded surface 26. Alternatively, the electrode 30 can be separate apparatus. The plenum 16, gas lenses 22 and 24, and electrode 30 are sometimes referred to collectively herein as a torch head.
Inert gas is supplied to the plenum 16 by communicating means, here defined by a port 32, best seen in FIG. 4. Port 32 is supplied with inert gas by a gas supply conduit 34 having a first end 36 projecting into the plenum 16, a second end 38 which here is generally parallel to the first end 36, a junction 39, and an ultimate supply conduit 40 leading to an inert gas supply 41. (The conduits and junction are shown in FIG. 1.) Unlike the supply conduits of many torches of the prior art, the conduit 34 has a curved central portion, and here is U-shaped, to circumvent an axially extending overhang (flange 46). The conduit 34 introduces inert gas to the plenum 16 from the side and generally parallel to the lenses 22 and 24.
In this embodiment, electricity is also conducted from a supply 47 to the electrode 30 via the conduits and junction 34 through 40 and the gas shield 12, all of which are made of copper or other highly conductive material.
FIGS. 1 and 2 show a workpiece 28 which is being rebuilt using the torch 10 according to the present invention. The workpiece 28 is a precisely machined jet engine turbine rotor which comprises a series of overlapping circumferential, axially extending flanges such as 42, 44, and 46. Each flange, such as the flange 44, has knife edge seals or ribs such as 48. The seals become worn when the rotor is used in a jet engine. FIG. 2 shows a worn circumferential surface 50 of the knife edge seal 48 and a built up circumferential surface 52 of the seal 48 which has been restored to or beyond its original dimensions. A subsequent machining step may be necessary to obtain the precise original dimensions of the seal 48.
The additional metal needed to build up the surface 50 and form the surface 52 is provided by a conventional wire feed 54 which feeds a wire 56 of weld metal into a puddle 58 defining the weld site. The wire feed 54 is also adapted to circumvent the overhang 46. The current supplied by the electrode 30 melts the wire 56, forming the puddle 58, and the workpiece 28 is rotated about its axis of revolution with respect to the stationary torch 10 and wire feed 54 to move the worn surface 50 to be welded into the weld site 58 and withdraw the built up surface 52 from the weld site 58. Each portion of the workpiece to be welded thus passes from a leading position to a trailing position relative to the torch 10. The rate of feed of the wire 56, the rate of rotation of the workpiece 28, and other factors are controlled so that the built up surface 52 is a uniform, accurately circumferential surface which has, or can be machined to have, its original dimensions. In this embodiment the torch 10 is fixed and the workpiece 28 is rotated by an appropriate drive means 59 in the direction indicated by the arrow 60. This relationship is shown in FIGS. 2 and 7.
As suggested above, one difficulty in this rebuilding operation is the substantial axial overhang of the flange 46 over the flange 44. The overhang prevents a torch and gas shield which are rigidly fixed in line with a rigid conduit such as 40 from being presented radially to the knife edge seals such as 48, which are substantially beneath the flange 46. A second problem which complicates the welding operation is the small clearance between the flange 46 and the knife edge seals such as 48, which means that inert gas must be presented from one side of the weld site (from the left in FIG. 1) and turned 90 degrees within the plenum 16, and yet must provide substantially uniform inert gas coverage to substantially exclude the ambient atmosphere between the outlet 20 and the surfaces 50 and 52. The features of the present invention which address these problems will now be described in greater detail.
First, the construction of the gas lenses will be described.
The inner lens 24 is recessed within the skirt 14, as is true of the single gas lens in a prior torch. FIG. 5 shows the airflow pattern through and about a single lens 24 of the prior art which is entirely recessed within the skirt 14 so that the outer surface 60 of the lens 24 is flush with the lip 18 or even recessed within the lip 18. The parallel arrows such as 62 show the substantially laminar flow of inert gas through the lens 24, and the arrow 64 shows the flow of ambient air from outside the skirt 14 which is entrained in the flow of inert gas. Turbulence is created immediately beneath the lip 18, which has a substantial width as it is the shell of the gas shield 12. This turbulence causes the air 64 to mix with the inert gas 62 near the lip 18, thus reducing the effective width of gas shielding.
FIG. 6 illustrates the airflow pattern in accordance with this invention when a flush inner gas lens such as 24 is overlaid with an outer gas lens 22 having a central portion, generally indicated at 66, which is substantially coextensive with the gas lens 24, and a marginal portion 68. Since the marginal portion 68 overlies the lip 18, the inert gas which makes its way into the region below the lip 18 is collimated to some degree by passing through the lens 22. As a result of the present construction with an outer lens 22 overlying the lip 18, the same shielding can be provided by a narrower gas shield 12 which can be inserted and used in a confined space.
The lens 22 is retained in place by a thin epoxy dielectric coating 70 shown in FIG. 2 (actually much thinner than suggested by FIG. 2), which extends over the outer surface 72 of the skirt 14 and the outer edge 74 of the gas lens 22. The coating 70 also prevents arcing between the shield 12 and the workpiece 28. The inner gas lens 24 can be separate from the outer gas lens 22, or can alternately be integral with the gas lens 22 and machined around its edge to provide the marginal portion 68.
Referring to FIGS. 2 and 4, the inner lens 24 is supported in the gas shield 12 by the lugs 76 and the electrode support means 78 further described below. The lugs 76 are adapted to minimally interfere with the flow of inert gas within the plenum 16, and the electrode support 78 is mostly upstream of the weld site 58.
In this embodiment, the electrode support means 78 comprises a post 80 integrally formed with the gas shield 12, a reinforcing member 82 also integral with the gas shield 12, and a bore 84 in the reinforcing member 82 which receives a setscrew 86 accessible from outside the gas shield 12 to provide a mechanically secure abutment having negligible electrical resistance between the electrode socket 88 and the base portion 90 of the electrode 30. The opposite end 92 of the electrode 30 is referred to herein as a probe, and projects outside the gas outlet 20 and outer lens 22 so that the sole path of electric current from the torch 10 to the workpiece 28 will be via the probe 92.
Many alternate electrode support means 78 can be devised. For example, to avoid some of the obstruction of inert gas via the reinforcing member 82, the electrode socket 88 could be shifted upwardly into the outer surface 94, thus reducing or conceivably eliminating the post 80 protruding into the plenum 16. In such an alternate embodiment, however, the base portion 90 of the electrode 30 would function in the same manner as the post 80, to a lesser degree.
Next, the flow of inert gas through the plenum 16 will be described, again with reference to FIGS. 2 and 4. The plenum 16 comprises a leading wall 96, a trailing wall 98 ("leading" and "trailing" being defined with respect to the progress of welding as shown in FIG. 2), and first and second laterally spaced opposing side walls 100 and 102. Sometimes the walls 96-102 are referred to collectively as the side wall of the plenum 16. In this embodiment, the leading wall 96 is substantially an arc of a circle centered on the axis of the electrode 30 to provide a shield of approximately uniform diameter about the electrode 30. The side walls 100 and 102 converge toward the trailing wall 98 and together with the wall 98 define the trailing end of the gas shield 12. This tapered construction of the trailing part of the gas shield 12 tends to maintain the velocity of inert gas flowing within the plenum 16 toward the trailing end.
The electrode support means 78 is spaced from and between the side walls 100 and 102 and adjacent the leading wall 96 to provide minimal interference with the flow of inert gas along the path overlying the weld (between the electrode 30 and the center of the trailing wall 98). This construction also provides an inert gas shield of optimal width using a narrow plenum.
The conduit 34 projects through the wall 100 and directs a flow of inert gas generally laterally ("laterally" means up or down in FIG. 4) into the plenum 16. The point of introduction of inert gas is opposite the electrode 30 to provide a direct flow of inert gas immediately to the weld site 58. The inert gas is introduced substantially parallel to the gas lenses 22 and 24. This lateral introduction of inert gas means that the inert gas flow does not impinge directly on any part of the gas lenses 22 and 24, which would tend to create a localized excess of inert gas where it impinged and a deficit of inert gas near other parts of the outlet 20. The portion 104 of the conduit 34 projecting through the wall 100 here has a square cross-section, although it can also have a cross-section of another shape.
In this embodiment of the invention, the port 32 comprises a lip 106 having a trailing edge 108 and a leading edge 110, of which at least the trailing edge 108 projects into the plenum 16 and laterally beyond the leading edge 110. This biased lip 106 encourages the stream of inert gas generally indicated as 112 exiting from the lip 106 to be diverted toward the leading wall 96.
To divide the stream of inert gas 112 coming from the port 32 into leading and trailing streams 114 and 116, in this embodiment the stream 112 is directed at the electrode post 80. The leading stream 114 thus tends to follow the surface 118 of the reinforcing member 82. The trailing stream 116 is directed adjacent to the trailing side of the post 80. Just as was illustrated with FIGS. 5 and 6 in relation to the lip 18 of the plenum, the flow of the trailing stream 116 by the electrode post 80 tends to cause turbulence of the trailing stream 116 past the post 80. This turbulence directs inert gas into the region 120 shown in FIG. 4.
Portions of the gas lenses 22 and 24 lie on the leading side of the electrode 30. Although FIG. 4 does not show this, some inert gas effectively flows over the reinforcing member 82, which does not fill the entire space between the setscrew 86 and the lens 22.
Since the gas lenses 22 and 24 slightly resist the flow of the inert gas through the outlet 20, a slight head of static pressure is maintained within the plenum 16 which tends to evenly distribute the inert gas within the plenum, particularly toward the trailing wall 98 of the plenum. Also, the stream 116 is directed somewhat downstream in this embodiment of the invention. Finally, the tapered trailing end of the plenum 16 has a smaller flow cross-section, and thus provides a greater inert gas velocity in the trailing end, than an untapered plenum would provide.
Another feature of the invention is illustrated in FIG. 2. The lip 18, the gas lenses 22 and 24, and the gas shield 12 are curved to generally follow the surfaces 50 and 52. This feature provides a substantially uniform clearance between the lip 18 and a circumferential surface of the workpiece 28. The curvature of these elements of the torch 10 is important, with reference again to FIG. 2, because it would be difficult to fit the torch 10 between the flanges 44 and 46, while providing a uniform inert gas envelope, if the lip 18 and the lenses 22 and 24 were flat. Thus, this torch is suited to build up a circumferential surface having a particular radius, with little clearance between the surface and the torch. | Apparatus for inert gas shielded arc welding having a plenum with an outlet covered by a gas lens. An electrode provides electric current to the part being welded. The gas lens can overlie the lip of the plenum to prevent ambient air from being drawn into the gas envelope and contaminating the weld. The plenum can be teardrop shaped, having sidewalls which converge toward the trailing end. To enable the torch to weld a circumferential surface which is confined by an overhang, the inert gas is introduced near the leading edge of the plenum by a U-shaped conduit which circumvents the overhang. The plenum is much wider than it is deep and the flow of inert gas for shielding can be turned generally perpendicular to the direction of its introduction. Finally, the inert gas introduced into the plenum can be directed at an electrode post within the plenum, and the lip introducing the inert gas into the plenum can have a trailing edge which projects further into the plenum than does its leading edge. These adaptations cause the stream of inert gas going into the plenum to be split by the electrode post, encouraging flow of inert gas into regions of the plenum obstructed by the electrode post. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to fuel burning heaters, more particularly, relates to a fuel burning heater having an inline heater for heating fuel that is bound for the burner. The invention additionally relates to a method of operating such a machine.
2. Discussion of the Related Art
Performing construction work in cold weather climates faces many challenges that are not confronted in warmer climates. In the context of excavation and earth-moving, frozen soil, as is typically confronted in arctic environments, requires substantially more energy, time and resources to move and manipulate. Also, the curing of concrete and other paving materials may be negatively impacted by such extreme cold temperature as required water evaporation and drying are particularly challenging when the liquid components freeze prior to evaporation.
These difficulties can be mitigated through the use of heaters to warm the work site area. One commonly used type of heater is a so-called indirect fired (IDF) heater that heats air and directs the hot-air to the area to be heated by blowing the air through large hoses. The air is heated by a burner that may be fueled by any of a variety of fuels including diesel fuel, kerosene, natural gas, or propane. Heaters that burn a liquid fuel, such as diesel fuel, typically use an atomizing burner supplied with the liquid fuel from a fuel tank via a pump. Atomizing burners operate by pressurizing a fuel oil and forcing it through a nozzle. The nozzle causes the fuel oil to atomize into fine droplets that are readily burned. The atomized fuel is exposed to an electric arc to begin the combustion reaction. When the reaction has stabilized, it is self-sustaining, and the electrode is no longer needed to maintain a flame. The fuel may be supplied in either a “one-pipe system”, in which a pump is sized to deliver only as much fuel to the burner as is needed at any given time, or a “two-pipe” system in which the pump delivers much more fuel than is typically required for combustion and the unused fuel is recycled back to the fuel tank. As much as 70-90% of the fuel pumped by a two-pipe system may be returned as unused fuel. Two-pipe systems typically are considered to be preferable to one-pipe systems because they are self-purging after an out-of-fuel condition. That is, air trapped in the fuel lines is automatically purged back to the tank as opposed to having to be manually bled from the fuel lines in a one-pipe system.
Most atomizing burners are designed for indoor use at near room temperature conditions. Several are designed to withstand temperatures now lower than 0° C., and no commercially available burner known to the inventors is capable of starting and operating at temperatures of −40° C. without some degree of modification to either the burner or the fuel supply. The limiting factor preventing operation below these temperatures is the fact that fuel viscosity increases as temperature decreases, resulting in the ejection of larger fuel droplets from the burner's nozzles at low temperatures. At low temperatures of on the order of −20° C. and lower, the larger atomized droplets are difficult to ignite and may not ignite at all. Even if ignition is established, the burner will run with excessive smoke because of ineffective precombustion mixing of the fuel and air.
After-market heaters are available for heating fuel as it is being ejected from the burner's nozzle, but such heaters are minimally effective, even for start up, at extremely low temperatures of on the order of −30° C. Even if these small heaters are effective at improving burner start-up, they are insufficient for maintaining a stable flame over prolonged use. Furthermore, installation of the after-market inline heater requires modification to the heater, and may compromise manufacturer warranties.
In addition, at extremely low temperatures, such fuel may form a solid wax precipitate which can clog both the fuel filter and the burner nozzle. Nozzle heaters are completely ineffective at preventing the formation of such a precipitate in a fuel filter.
Various tank-based or inline heaters have been proposed in an effort to alleviate these problems, but all such heaters have disadvantages. Some are supplied with energy with heat from the burner and, as such, are completely ineffective at start-up when the heater's components are at or near ambient temperature and heating is most critical. Other, electrically powered heaters, require so much energy to operate that they dramatically increase the electrical power draw of the heater.
Despite these prior attempts to design a heater for use in cold weather climates, there remains need for improvement. In light of the foregoing, a heater configured to recirculate and effectively pre-warm fuel is desired.
SUMMARY OF THE INVENTION
One or more of the above-identified needs are met by providing a fuel burning heater having an inline fuel heater and a plumbing system for recirculating warmed fuel. The heater is ideally suited for use with air heaters, but is usable with other devices that require burning fuel in cold weather climates.
In accordance with a first aspect of the invention, a heater is provided, having a supply line for transporting a volume of fuel between a fuel tank and burner. An inline heater for heating the fuel and a fuel filter are located in the supply line between the fuel tank and the burner. The heater also has a return line in fluid communication with the burner and returning a volume of unused fuel from the burner to a valve provided in the return line. The valve is selectively movable between two positions, the first position directing fuel into the fuel tank, and the second position directing fuel into the supply line upstream of or into the inline heater. The recirculation of warmed unused fuel into the supply line at a position upstream of or into the inline heater allows the warmed recirculated fuel to mix with cold fuel drawn from the fuel tank. This results in a pre-heating of the fuel being drawn into the inline heater from the fuel tank, and thereby significantly decreases the electrical burden on the heater.
In one embodiment, the valve is manually operated so as to normally deliver fuel to the heater and to be switchable to deliver fuel back to the tank only, e.g., during a purge operation following an out-of-fuel condition.
The heater may be thermostatically controlled to deliver fuel to the burner at a set, possibly controllable temperature. That temperature preferably is above a temperature at which the fuel is effectively atomized by the burner but below the flash-point of the fuel.
In accordance with yet another aspect of the invention, a method of operating a heater is provided including the steps of directing a first volume of fuel from a fuel tank to an inlet of an inline heater, directing a second volume from a burner to the inline heater via a return line, combining the first and second volumes of fuel in or upstream of the inline heater to form a combined volume of fuel to preheat the first volume of fuel, and heating the combined volume of fuel with an electrical heating element. Additional steps include directing the combined volume of fuel through an outlet of the inline heater to an inlet of the fuel filter, filtering the combined volume of fuel using the fuel filter, directing the combined volume of fuel to the burner, burning a portion of the combined volume of fuel at the burner, directing an unused volume of the combined fuel to a valve in the return line. The valve is switchable to selectively deliver fuel to the inline heater or to the fuel tank, respectively.
These and other objects, advantages, and features of the invention will become apparent to those skilled in the art from the detailed description and the accompanying drawings. It should be understood, however, that the detailed description and accompanying drawings, while indicating preferred embodiments of the present invention, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred exemplary embodiment of the invention is illustrated in the accompanying drawings in which like reference numerals represent like parts throughout, and in which:
FIG. 1 is a perspective view of an indirect fired air heater constructed in accordance with a preferred embodiment of the invention;
FIG. 2 is a partially cut away perspective view of the interior of the heater of FIG. 1 ;
FIG. 3 is another partially cut away perspective view of the interior of the heater of FIG. 1 ; and
FIG. 4 is a schematic illustration of the heater of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A wide variety of heaters could be constructed in accordance with the invention as defined by the claims. Hence, while the preferred embodiments of the invention will now be described with reference to an indirect-fired air heater, it should be understood that the invention is in no way so limited.
FIGS. 1-2 illustrate a perspective view of a heater assembly 10 constructed in accordance with one embodiment of the invention. FIG. 1 shows that the heater assembly 10 can be mounted on a trailer 12 for transport. If a trailer 12 is provided, the heater assembly 10 can remain on the trailer 12 during operation. Alternatively, the heater assembly 10 can be moved to and from a worksite by some other mode of transport and supported directly on the ground during operation.
As can be seen in both FIGS. 1 and 2 , the heater assembly 10 includes a casing 14 having air inlet and outlet vents 16 , 18 that can be connected to hoses (not shown) to convey air from and to the worksite, respectively. Located within the casing 14 are a blower 20 , a fuel tank 22 , and an indirect fired heater, i.e. burner 24 . The blower 20 is a centrifugal blower powered by a motor 26 . The blower 20 has an axial inlet 28 connecting the air supply inlet 16 to a radial outlet 30 . A generator 32 is mounted on the trailer 12 in front of the heater assembly 10 for powering electrically-powered components of the heater assembly 10 , including the inline heater 34 , discussed below. Alternatively, electric power could be supplied to those components via a cable coupled to a main electrical source located at the worksite. It is also conceivable that the electrical components of the heater assembly 10 could be powered by an onboard battery or bank of batteries, but rapid power drains at low temperatures render batteries a less-preferred option, particularly in cold climates.
Referring particularly to FIG. 2 , the heater assembly 10 includes a burner 24 , a fuel supply assembly 36 that supplies fuel to and from the burner 24 , a combustion chamber 31 , and a heat exchanger 33 . The burner 24 comprises an atomizing burner having an internal gear pump (not shown) and one or more nozzles (also not shown) that open into the combustion chamber 31 . The burner 24 heats air in the combustion chamber that indirectly heats air flowing through the heat exchanger 33 from the outlet 30 of the blower 20 to the air supply outlet 18 of the heater assembly 10 . Referring to FIG. 4 , the burner 24 of this embodiment is part of a two-pipe system having an internal gear pump (not shown), having a fuel inlet 46 coupled to the fuel supply system and unused fuel outlet 50 . The burner 24 further comprises an electric ignition source which, when activated, triggers the combustion of the atomized fuel delivered to the nozzle by the gear pump. Once the combustion reaction has been initiated, the electric ignition source is not required to maintain the flame.
Still referring particularly to FIG. 4 , the fuel supply system 36 includes a fuel tank 22 , a supply line 40 , an inline heater 34 , a fuel filter 42 , and a valve 44 . For the sake of visual clarification, FIG. 3 further illustrates these elements without depicting the fuel supply system 36 . The supply line 40 connects the fuel tank 22 indirectly to the inlet 46 of the gear pump. The inline heater 34 is located within the supply line 40 , between the fuel tank 22 and the burner 24 . The fuel filter 42 is also located within the supply line 40 between the inline heater 34 and the burner 24 . A return line 48 connects the unused fuel outlet 50 of the gear pump to the valve 44 . The valve 44 has a housing 38 ( FIG. 3 ), one inlet 52 for receiving unspent fuel from the burner 24 , and first and second outlets 54 , 56 . The first outlet 54 is coupled to the fuel tank 22 via a first downstream branch 58 of the return line 48 that serves as a purge line. The second outlet 56 is connected to the supply line 40 via a second downstream branch 60 of the return line 48 . The second downstream branch 60 of the return line 48 may open into the supply line 40 upstream of the inline heater 34 or into the inline heater 34 itself, preferably at or near an inlet 66 thereof. Since the valve 44 is intended to supply fuel to the second downstream branch 60 of the return line 48 at all times except during a purge operation following an out-of-fuel condition, the valve 44 can be a simple manual operated valve, such as a ball valve.
The inline heater 34 is an electrically powered, thermostatically controlled heater that heats the combined volume of fuel supplied thereby via the supply 40 and return lines 48 . Since the vast majority of the fuel being heated (typically on the order of 70% to 80%) is warm recirculated fuel being supplied from the return line 48 , the power requirements of the inline heater 34 are dramatically reduced when compared to a heater that heats the entire volume of fuel being withdrawn from the fuel tank in a two-pipe system. Referring again to FIG. 3 , the inline heater 34 preferably is formed of an external housing 64 having an inlet 66 and an outlet 68 . The housing 64 may be an aluminum tube tapped at both the inlet 66 and outlet 68 ends of the tube. Around the exterior of the housing 64 , a layer or multiple layers of thermal insulation may be provided to prevent heat loss, and improve efficiency of the inline heater. Within the housing 64 , the inline heater 34 has an electric immersion heater (not shown) formed from electrical heating elements (also not shown) in contact with fuel flowing through the inline heater 34 . The heating elements may be of various sizes, as is required to adequately heat the volume of fuel flowing through the inline heater 34 . In one embodiment, the heating element may be a heating pad wrapped along the inner circumference of the inline heater housing 64 . A thermostat (not shown), such as a bimetallic thermostat, preferably is provided for controlling the inline heater 34 to heat the fuel to a desired, settable temperature. That temperature preferably is within a range above that required to achieve adequate fuel atomization and below the fuel's flashpoint. In the case of #2 diesel fuel oil (the fuel most commonly used in heaters of the disclosed type), that range preferably is between 0° C. and 65° C. An additional backup, such as a thermally actuated electrical fuse (not shown), may be integrated into the inline heater 34 , as to disrupt the flow of electricity to the inline heater 34 at a predetermined temperature beneath the fuel flashpoint.
Still referring to FIGS. 3 and 4 , the fuel filter 42 is located downstream of the inline heater 34 , and is in fluid communication with the inline heater outlet 68 by means of the fuel supply line 40 . The fuel filter 42 is formed of an external housing 70 having an inlet 72 and an outlet 74 . The warmed fuel is received at the inlet 72 , and subsequently passes through an internal filter element (not shown), before exiting the outlet 74 . Filtration of the fuel is critical for removing undesirable contaminant, which may damage the gear pump or clog the burner 24 , unless removed. When using diesel fuel additional contaminants, such as water, may also be separated at the fuel filter.
In operation, as illustrated in FIG. 4 , activation of the burner 24 and the gear pump assembly draws fuel from the fuel tank 22 into the supply line 40 . The fuel, which in cold weather climates may be at a temperature of approximately −40° C., is then mixed with fuel being returned from the gear pump assembly via the valve 44 and preheated by that fuel to form a combined volume of preheated fuel that may be of a temperature of 0° C. to 40° C. As mentioned above, returned fuel typically will comprise in excess of 50%, and up to 80% or more of the total volume exiting the inline heater 34 . The combined volume is warmed to a final temperature of 10° C. to 65° C., by way of passing over the heating element located within the inline heater 34 . The warm fuel subsequently travels through the fuel filter 42 where undesirable contaminants are removed. Since the filtered fuel is well-above the temperature above which wax may precipitate in the filter 42 , filter clogging is avoided. The filtered fuel then flows to the burner 24 and gear pump assembly. At the burner 24 , a fraction of the warm fuel is combusted to heat the surrounding air in the combustion chamber. Because the warm fuel is easily atomized by the burner 24 , efficient (i.e. relatively smokeless) combustion without the use of a nozzle heater can be easily achieved. The unspent or non-combusted fuel then travels into the return line 48 , where it is received at the valve inlet 52 . During normal operation in which the inlet 52 of the valve 44 is connected to the second outlet 56 , the returned fuel is delivered to the inline heater 34 , via the second downstream branch 60 of the return line 48 , where the process is repeated.
Prior to start up, it may be desirable to purge the fuel lines, i.e. fuel supply assembly 36 , of the heater assembly 10 . This is particularly important following a complete fuel burn off, during which the fuel lines 36 of heater assembly 10 may become filled with air, as opposed to fuel. The fuel lines 36 can be purged by switching the valve 44 to connect the inlet 52 to the first outlet 54 , and thereby the purge line 58 and operating the pump for a sufficient period of time to fully purge the air from the fuel supply assembly 36 . This purging may be performed either with or without operating the inline heater 34 . The valve 44 is then switched back to the second position, in which the valve inlet 52 is in communication with the second outlet 56 , and the burner 24 is ignited to heat air.
Tests of the heater assembly 10 according to the embodiment of the present invention have been performed by retrofitting of a Wacker Neuson Cub 700 Mobile heater assembly 10 with the inline heater 34 and recirculation fuel supply assembly 36 , as discussed above. The inline heater 34 was connected to an external generator 32 by way of a 115V 60 Hz male plug. At negative thirty degrees Celsius (−30° C.), with the inline heaters 34 not operating, the heater assembly 10 could not be started. However, at negative thirty degrees Celsius (−30° C.), with the inline heaters 34 operating, the heater assembly 10 could both be started and maintain a flame at the burner 24 throughout an overnight operating test. Subsequent testing has also indicated that, at negative forty degrees Celsius (−40° C.), the heater assembly 10 of the present invention was able to start and maintain a flame at the burner 24 , after the inline heater 34 was allowed to warm the fuel in the fuel supply assembly 36 for ten minutes.
Many changes and modifications could be made to the invention without departing from the spirit thereof. The scope of these changes and modifications will become apparent from the appended claims. | A heater and a method of its use are configured for use at cold operating temperatures. The heater has a supply line for transporting a volume of fuel between a fuel tank and burner. An inline heater is supplied in a supply line for the burner. The heater also has a return line that normally returns unused fuel from the burner to the heater, hence reducing the volume of fuel that needs to be heated by the heater and reducing system power requirements. The heater may be thermostatically controlled to maintain the temperature of the heated fuel to a value that is at or above a temperature required for good fuel atomization but below a flashpoint of the fuel. A valve is provided in the return line to permit diversion of the returned fuel to the fuel tank during a purge operation at initial startup. | 5 |
BACKGROUND
Field of Invention
This application relates to the off-site manufacture and on-site assembly of prefabricated dwelling units. Prefabricated dwelling units may be single, stand-alone Units, or individual Units within a group of Units such as a duplex, triplex, condominium complex or apartment building.
The construction of a conventional site-built dwelling unit is a multi-step process fraught with various pitfalls. Corruption, delays and damage are all but inevitable in a complex process involving multiple suppliers and trades that must be coordinated chronologically and simultaneously. The necessity to coordinate and work with different suppliers and skilled trades causes difficulty with scheduling, personnel conflicts, communication, and safety. The process can easily become lengthy, costly and inefficient. These multiple trades include but are not limited to: grading, sitework preparation, laying and pouring of foundations, framing, erection of structural walls, door and window cut-outs, roof construction, plumbing installation, electrical wiring, cat-5/network cabling, HVAC installation, alarm installation, laying of floors interior and exterior coverings, and final finishes and trims. These problems are inherent to the conventional site-built process when building locally with workers or other entities one is familiar with, and are magnified when building with workers one is not familiar with, or when building elsewhere than one's primary business location such as out of state or, especially, overseas.
Further, since each step is performed on-site, builders are forced to contend with a number of factors beyond their control. Inclement weather such as rain, snow, wind, heat, typhoons, hurricanes, blizzards, cold and other extremes can slow or halt construction, while ruining stored building materials before they are installed.
Meanwhile, the security of construction equipment and materials must be addressed as thieves or the trades' own workers may often pillage construction sites by stealing valuable tools, equipment, and materials needed for the project.
SUMMARY
The shipping of prefabricated dwelling units may work within existing transportation system constraints such as road widths, bridge heights, and laws which inevitably vary from state to state and country to country. Towing a prefabricated dwelling unit down the road for a local delivery may be ideal over short distances, but this method is impractical for long distance shipment within the United States or overseas. One practical shipping method that is available is the use of existing standardized shipping containers which can be transported by sea, rail, or road to almost any location in the world.
However, the materials and components of an individual prefabricated dwelling unit do not fit within the confines of a standard shipping container in any of its available sizes unless either: a) the design of the prefabricated dwelling unit is severely limited to closely conform to the size of the shipping container resulting in a less desirable dwelling unit with substandard (less than 96″) ceiling heights; or alternatively if the amount of prefabrication is greatly reduced to enable more packing flexibility which significantly decreases the purpose of prefabrication.
In light of the foregoing, it would be most advantageous to have a dwelling unit that is not bound by the size, shape, and ceiling height of a standard shipping container, but can still be shipped in a single shipping container while maintaining a high degree of prefabrication. This configuration may maximize many of the advantages of prefabrication over site-built construction while maintaining much of the design flexibility of site-built structures. Moreover, it may minimize the costs and logistical troubles associated with long distance shipping and storage.
This application describes the off-site manufacture and on-site assembly of a prefabricated dwelling unit (“Unit”) that may be either a single stand-alone Unit or an individual Unit within a group of Units such as a duplex, condominium or apartment building. The Unit may be substantially prefabricated, having its walls, floors, and fixtures pre-installed. Further, the Unit that is configurable to a smaller size that may reside in a single shipping container along with all necessary components and tools for completion and installation of the prefabricated dwelling. For example, the Unit may fit in a single shipping container by nesting within itself through moveable walls and fold down floors attached to a flush flooring system. The Unit may fully reside in and may be loaded and unloaded from a standard single shipping container without limiting the size, shape, or aesthetics of the Unit. The Unit may include a high degree of prefabrication that requires minimal site-built assembly once delivered to the end user. The following integrated innovations allow a majority of the most time consuming and skill intensive tasks such as floor and wall framing, wiring, plumbing, fixture, and cabinet installation to be prefabricated and preinstalled into a Unit which may fit into a single shipping container, yet will not be limited to the size or shape of the shipping container.
This application describes a unique floor framing system and rollers, each of minimal thickness that maximizes the wall and ceiling heights of a Unit in relation to shipping container height. In one embodiment, the Unit may have a 96″ wall height. The Unit may also be configured to be shipped in a standard “High Cube” shipping container. The system may include a floor framing system comprised of metals or other suitably strong materials and a series of rollers, which may be removed from the Unit. These rollers protrude a minimal distance below the floor frame of a Unit. The rollers may permit a Unit to be rolled into or out of a container, or alternatively, rollers may be installed within the container floor protruding a minimum distance above the container floor to allow the same rolling function performed by the rollers when they are attached to the frame. The floor framing systems may further contain integral leveling bolts enabling the Unit to be rapidly leveled once placed on a site-built foundation, and/or integral tie-down devices to permanently secure the Unit in place on its foundation. The Unit may also contain integral foundation supports and/or soil screws enabling placement directly upon native soil as appropriate.
This application describes a Unit with preinstalled 96″ (e.g., 8 feet) tall walls. The capability to preinstall the walls means other interior components of the Unit such as cabinetry and bathroom fixtures, which may be installed against and connected into walls, may also be preinstalled.
This application further describes one or more expandable sections consisting of one or more foldable floor section(s) utilizing a unique hinge in this application or other means of allowing the foldable floor section(s) to be rotated into place along with one or more prefabricated, moveable exterior wall section(s). In an embodiment, the desired configuration is achieved by folding the Unit's folding floor section(s) down into place, removing the hinges, and then shifting the moveable wall section(s) into their respective foldable floor section(s) so that multiple sections of the house may reside within each other.
The moveable wall configuration process may include a linear movement of the moveable wall section(s) from the moveable wall section's shipping position on the main floor of a Unit out to a corresponding foldable floor section. The configuration may be further eased by various mechanisms in the design, which reduce the friction of a moveable wall section against the floor, such as small retractable wheels or rollers which may be removable wheels that are affixed to the bottom of a moveable wall section, or via an integrated air bearing system. In one embodiment, the moveable wall section(s) may be prefabricated prior to shipment including interior and exterior finishes so that internal wiring, plumbing, and other systems, once moved into final position, may be connected to corresponding adjacent systems in adjacent, non-moveable portions of a Unit.
The configuration capabilities of the Unit are a significant and unobvious advantage to the prior art as they enable a Unit of larger size and shape to be nested into a single shipping container for storage and shipping. The ability to utilize a single shipping container is advantageous, as a single container is simpler logistically, and substantially more economical than multiple containers.
Remaining components for completion of the Unit may include ceilings and roofs which may be securely stored in the empty shipping container until ready for use, minimizing risks of theft or damage from exposure to inclement weather. The components of the Unit may include prefabrication including panelization to be quickly assembled on-site depending upon the particular design of a Unit. Once the final components have been installed, the empty shipping container may be returned, or may be integrated as an attached or detached garage or other accessory structure to the Unit.
These and other objects and advantages of the present application shall be made apparent from the accompanying drawings and the description thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention. The general description of the invention given above, and the detail description of the embodiments given below will serve to further explain and clarify the embodiments.
FIG. 1 is an illustration of the Unit loaded into a shipping container.
FIG. 2 is an illustration of a 1st story of a completed Unit.
FIG. 3 is an illustration of a 2nd story of a completed Unit.
FIG. 4 is an illustration of a Unit being unloaded from a shipping container.
FIG. 5 is an illustration of a Unit unloaded onto a foundation.
FIG. 6 is an illustration of a foldable floor section in final position.
FIG. 7 is an illustration of a moveable wall section in final position.
FIG. 8 is an illustration of the inside of a moveable wall section.
FIG. 9 is an illustration of a floor hinge with foldable floor section folded up.
FIG. 10 is an illustration of a floor hinge with foldable floor being folded down.
FIG. 11 is an illustration of a floor hinge with foldable floor folded down.
FIG. 12 is an illustration of rollers & tie down devices.
FIG. 13 is an illustration of an integral cam lock and integral floor leveling device.
FIG. 14 is an illustration of framing inside an assembled Unit.
FIG. 15 is an illustration of a front view of an assembled Unit.
DETAILED DESCRIPTION
Overview
Following is a detailed description of the embodiments described in the application of the invention with reference to the accompanying drawings. The particularity of these drawings and their related description should not be construed as the only embodiments protected by the claims.
Illustrative Nested Structure
Referring to FIG. 1 , numerals 1 , 1 a and 1 b are the walls of the standard High Cube shipping container. 1 c and 1 d are separate wall sections affixed with hinges and a locking mechanism that forms the loading door of the shipping container. The longitudinal fixed walls 2 of the transportable structure may include the bathroom walls 2 b and bathroom fixtures 2 c , the bathroom fixtures including bathtub, toilet and vanity. The fixed walls 2 may also include the stairs and supporting structure 2 d and kitchen cabinets, granite counter tops, and related plumbing and fixtures 2 e . The fixed walls may be permanently affixed to the floor and frame assembly (reference numeral 9 , as seen in FIG. 4 ). In this embodiment, the fixed wall section 2 may be prefabricated and complete with affixed concrete composite exterior siding, insulation, and interior gypsum wall board. Additionally, the fixed wall 2 may include electrical wiring and plumbing as well as a plurality of windows, one of which may be used as an emergency egress exit for a bedroom. Moreover, the fixed wall section 2 may include an installed electrically energized water heater 3 . Also, a hinged floor assembly 4 is shown in the shipping position and is fastened to the moveable wall section 5 which is also shown in its nested shipping position. The moveable wall section 5 may also be prefabricated with similar components as seen in the fixed wall section 2 with the addition of pre-hung exterior doors and the air bearing components illustrated in FIG. 8 . Numerals 6 , 7 , and 8 disclose areas within the fixed wall structure 2 and container 10 where setup and finishing materials may reside. The setup and finishing materials may include additional framing materials, insulation, exterior siding, steel roofing panels, garage door, miscellaneous fasteners, gypsum wall panels, floor decking, floor tile, paints and primers, appliances, and various decorative attachments secured for shipment.
Illustrative Assembled Unit
FIG. 2 is an illustration of a top view of the first floor of an assembled Unit. Stairs 3 provide access to a second story of the assembled Unit.
FIG. 3 is an illustration of the top view of the second floor of an assembled Unit which is accessible from the first floor via the stairs 3 .
Illustrative Steel Framework
As shown in FIG. 4 , the frame 9 , depicted in cutaway view, may include welded steel tubing construction fitted with pressure treated floor decking on top of the frame 9 . Additionally, expandable foam insulation may fill the spaces between the steel frame tubes and the fixed wall section 2 . The container 10 , as shown with the loading doors 1 c and 1 d removed for clarity, may be guided by grease lubricated 1″×4″ wooden battens, 10 a . Rollers 26 , detailed in FIG. 12 , may facilitate loading and unloading of the Unit structure. Further, integral cam locks 12 , integral floor leveling device 13 , tie down device 14 , the hinged assembly 16 , the moveable wall section 18 , the axle plate 29 , the square tube frame assembly 30 , and the floor joist 35 will be described below.
Illustrative Deployment from a Shipping Container
FIGS. 5 , 6 , and 7 show the structure after deployment from the shipping container. The Unit may sit on the pre-poured concrete foundation 15 , in accordance with the local building jurisdiction and engineering specifications. The structure may be leveled using the integral floor leveling devices that will be discussed in FIGS. 12 and 13 and may be fastened to the foundation as detailed in FIG. 12 using Powers “power spike” fasteners. The hinged floor assembly 16 may be lowered to the foundation by unfastening moveable wall section 18 and carefully lowering it down to the foundation 15 . After the hinged floor assembly is placed on the foundation 15 , the hinges 17 may be removed by removing previously installed threaded fasteners. The hinged floor 16 may then be leveled using the integral floor leveling devices and may be fastened to the foundation using the Powers “power spike” fasteners detailed in FIG. 12 . A compressed air source may be connected to airline 22 that is integrated into the moveable wall section 18 . The moveable wall section 18 may be moved into position using the compressed air as a lubricant as seen in FIG. 8 . Once in position, the moveable wall section 18 may be fastened to the hinged floor assembly.
FIG. 8 illustrates the integral wall bearing which may include the standard sill plate and channel 46 , with a series of, in one embodiment, ⅛″ holes 19 that are drilled in a 3″×12″ grid ¼″ on center. Then, a steel cover plate and box 20 that is approximately 3¼″×13″×1″ tall with an open bottom may be welded and epoxied directly above the holes. The integrated wall bearing also may include an air inlet 21 connected to the cover plate box and an attached air source line 22 that provides compressed air through the moveable wall section 18 . For example, the air source line 22 may be routed to the next location (approximately 4′ on center) through the steel studs 23 , and may be connected to an identical section of the sill 18 by means of a T fitting.
Illustrative Hinge Action
FIGS. 9-11 illustrate the “action” of the hinge 24 . The hinge 24 consists of 4 pieces of punched steel and hinge pins 24 a and may be configured to enable the hinged floor 16 to fold up perpendicular to the main framing and also to slide into the structure and sit squarely upon frame/floor section 25 . This configuration, thus, provides for loading of the shipping container without any obstructions.
Illustrative Framework
FIG. 12 illustrates the frame 9 in greater detail. The frame 9 may include a square tube frame assembly 30 with “c” channel floor joists 35 . A steel roller 26 and roller bearing assembly 27 , fitted in each end of the roller, may be attached to the square frame assembly 30 using the axle 28 and axle plate 29 . A spacer 31 may center the steel roller 26 on the axle 28 . The axle assembly may be mounted to project slightly below the frame to facilitate easy and relatively effortless loading and unloading of the unit from the shipping container. The frame 9 may also include a tie down device 32 , consisting of a strategically drilled steel plate containing the requisite amount of holes to precipitate the Power spike 33 installation. The “c” channel floor joist 35 , is also shown with a preformed tab 34 , and a welding rivet 36 attaching the floor joist 35 to the square tube frame 30 .
Illustrative Cam Lock Device
FIG. 13 has the integral floor-leveling device 37 which, in one embodiment, may be installed in the square tube frame 30 approximately 60″ on center longitudinally down each tube. The device consists of a nut 38 welded to the bottom of the square tube assembly 30 , a threaded bolt 39 that is screwed into the nut 38 , and an access hole in the steel tube frame directly above the welded nut 38 . Once the frame 30 is in the final assembly position on the concrete foundation 15 , the threaded bolt 39 may be adjusted utilizing a standard socket wrench and standard carpenter's level. Also shown in FIG. 13 is the integral cam lock 40 which may include steel rod 41 , locking assembly 42 , and the oblong cam 43 . Once the structure is loaded in the standard shipping container the steel rod 41 may be rotated, which turns the oblong cam 43 into the shipping position. The oblong cam 43 bears on the inside of frame 30 as well as the wooden guide plate 44 that is positioned between the cam 43 and the container wall 45 . The oblong cam 43 secures the structure during shipment from unnecessary movement. Once the Unit is on site, the locking assembly 42 is unlocked, and handle 41 is rotated up to release the oblong cam 43 .
Illustrative Unit Construction
FIG. 14 depicts the steel framing of the Unit structure, with siding, insulations, and wall board removed for clarity. Once the moveable wall section 18 is affixed to the foundation the 2 nd story of the Unit (in certain embodiments having two levels) is deployed. Pressure treated plywood decking or similar materials may be attached to the Unit floor using threaded attachment fasteners prior to installation of interior partition walls and related doors. The porch as well as the garage may be similarly deployed. The following describes the relatively small amount of finishing that may be used to complete the substantially pre-built Unit. The finishing materials may include ceiling insulation, vapor barrier, and steel roofing which are easily attached using supplied threaded fasteners. Electrical wiring is uncoiled and extended from the junction boxes located on the first floor fixed walls to the appropriate electrical junction box on the second floor. Supplied finishing materials may be applied and final paint may also be applied. On-site plumbing and electrical services may be connected through an access panel in the bathroom floor. Supplied cement based backer board may be applied to the pressure treated plywood flooring and ceramic tile may be installed throughout the structure. The exterior siding and decorative trim may be finished and coated with the included “stucco” coating and any decorative rock or stone (if applicable is attached. Lighting fixtures may be attached to pre-installed electrical pig tales. The rollup garage door may also be installed and the structure is ready for final inspection and occupancy.
FIG. 15 shows some examples of the finished product that may be stored in one container including two story house designs that may expand out of a single container.
Alternative embodiments may also include an air-bearing wall system and panelized components for the home.
Conclusion
Although embodiments have been described in language specific to structural features and/or methodological acts, it is to be understood that the embodiments are not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as illustrative forms of implementing the embodiments. For example, while embodiments are described having certain shapes, sizes, and configurations, these shapes, sizes, and configurations are merely illustrative. | The off-site manufacture and on-site assembly of a prefabricated dwelling unit (“Unit”) are described herein. The Unit may be a single stand-alone Unit or an individual Unit within a group of Units such as a duplex or apartment building. The Unit is substantially prefabricated and nests within itself through a configurable design that utilizes a floor framing system. The Unit may also include fold down floor assemblies, moveable walls of 96″ height, pre-installed floors and fixtures. The Unit may be configured for a decreased footprint that will fit into a single shipping container along with the other necessary components for completion of the Unit on-site. The Unit may be loaded and unloaded from a single shipping container without substantially limiting the size, shape, or aesthetics of the Unit while being substantially prefabricated. | 4 |
TECHNICAL FIELD OF THE INVENTION
[0001] The invention relates to controls for an agricultural combine. Particularly, the invention relates to controls for traction, such as speed, braking and wheel drive engagement and for undertaking movements of the combine header, unloading auger, and separator.
BACKGROUND OF THE INVENTION
[0002] Conventional agricultural combines include a header leading the combine, having a forward gathering portion and a feederhouse portion which contains elements for processing crop material and/or transferring the crop material from the gathering portion to the body of the combine. In the body of the combine, the grain is separated from the chaff and straw, collected, and thereafter unloaded via an auger. Such combines have a variety of designs as described for example in U.S. Pat. Nos. 4,450,671; 4,663,921; 5,445,563; and 6,257,977.
[0003] The operator of a combine has to control and sequence many functions during the normal course of operation of the combine. Particularly, as the combine is harvesting a field, at the end of each row or “cut” many implements and controls on the combine need to be changed or adjusted. For example, as the combine approaches the end of the cut, the operator must push a button to raise the header, then he must push the hydrostatic transmission control handle in a forward direction to speed up the combine, and he must turn the steering wheel. The unloading auger must be swung inboard to avoid contact with external structures while turning. It is also possible that the operator needs to depress the brake pedal to get the combine to steer effectively or the operator may need to disengage the four wheel drive in order to move more quickly to the point of reentering the field again, at which time it may be desired to slow the combine while lowering the header, engaging the four wheel drive, etc. Because of the number of operations that are necessary simultaneously, a high degree of drive expertise is needed to orchestrate all of the adjustments and control changes.
SUMMARY OF THE INVENTION
[0004] The present invention provides a function management system that includes a programmable control unit which can automatically coordinate combine traction functions and/or implement functions.
[0005] The invention provides at the touch of a button, the ability to activate a series of functions for the combine. For example, as the combine approaches the end of a cut, at the touch of one end-of-cut button, the header can be raised, the unloading auger can be swung back to an inboard position for safe turning, the ground speed can be increased for rapid travel, the four wheel drive used during harvesting in the field can be disengaged, transmission gear ratio can be changed, and the crop-processing implement speed, such as a rotor speed for a rotary crop-processing unit, can be decreased. Another button can be touched to command the commencement of another sequence when the combine returns to the point of reentering the field.
[0006] According to one sequence, the machine would automatically slow to 2 kph as the header drops to the cut position, then as the machine enters the cut, the ground speed can be automatically increased to the maximum speed set by the operator, or to whatever maximum speed the combine can be operated, to maximize efficiency or to avoid overloading of the engine. The unloading auger may also automatically swing out for unloading grain as the combine is moving. The sequence of device operations can be pre-programmed or input by the operator in a learn mode.
[0007] According to another aspect of the invention, the combine steering could be automatically controlled by the function management system, especially between the end of one cut and the beginning of the next cut. The steering and combine direction could be corrected by a global positioning system in communication with the control unit.
[0008] According to a further aspect, during a “learn mode,” the operator can perform a sequence of manual manipulations of the traction and implement devices, and the control unit records and then stores information pertaining to the sequence of device operations. The sequence can be correlated with the distances traveled by the combine between operations. Upon subsequent activation of a button, the control unit can then commence an “execute” or “replay” mode, wherein the control unit automatically performs the recorded sequence of device operations. Preferably, the sequence of operations is performed at the same distance intervals at which they were learned, regardless of the speed of the vehicle.
[0009] Numerous other advantages and features of the present invention will become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims and from the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a side view of an agricultural combine having the control system of the present invention;
[0011] [0011]FIG. 2 is a schematic system diagram of the operating system of the invention;
[0012] [0012]FIG. 2A is a schematic system diagram of a header raise-and-lower operating sub-system of the system shown in FIG. 2;
[0013] [0013]FIG. 3 is a view of a front panel face of a control/display unit of the combine of FIG. 1;
[0014] [0014]FIG. 4 is a simplified logic flow diagram illustrating the operation of the learn/save mode of the present invention; and
[0015] [0015]FIG. 5 is a simplified logic flow diagram illustrating the operation of the execution mode of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] While this invention is susceptible of embodiment in many different forms, there are shown in the drawings, and will be described herein in detail, specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated.
[0017] [0017]FIG. 1 shows an agricultural combine 10 such as disclosed in U.S. Pat. No. 6,257,977, herein incorporated by reference. The combine 10 illustrated is of the type incorporating an axial rotary crop-processing unit. The combine 10 comprises a supporting structure or chassis 12 mounting a ground engaging means 14 shown in the form of tires. Alternatively, tracks can be used in place of tires. A harvesting platform 16 is used for harvesting a crop and directing the crop to a feederhouse 18 . The harvested crop is directed by the feederhouse 18 to a beater 20 . The beater directs the crop upwardly to a rotary crop-processing unit 24 . The rotary crop-processing unit is located between the side sheets of the combine. The side sheets form part of the supporting structure 12 .
[0018] The rotary crop-processing unit 24 comprises a rotor housing 26 and a rotor 28 located within the housing. The harvested crop enters the housing through an inlet 22 at the inlet end 30 of the housing 26 . The rotor is provided with an inlet feed portion 32 , a threshing portion 33 , and a separating portion 34 . The rotor housing has a corresponding infeed section 36 , a threshing section 38 , and a separating section 40 .
[0019] Both the threshing portion 33 and the separating portion 34 of the rotor are provided with crop engaging members (not shown). The threshing section 38 of the housing is provided with a concave 46 while the separating section 40 of the housing is provided with a grate 48 . Grain and chaff released from the crop mat fall through the concave 46 and grate 48 . The concave and the grate prevent the passage of crop material larger than grain or chaff from entering the combine cleaning system 50 below the rotary crop-processing unit 24 .
[0020] Grain and chaff falling through the concave and grate is directed to the cleaning system 50 that removes the chaff from the grain. The clean grain is then directed by an elevator (not shown) to clean grain tank 52 where it can be directed to a truck or grain cart by unloading auger 54 . Straw that reaches the end 61 of the housing is expelled through an outlet 56 to a beater 58 . The beater propels the straw out the rear of the combine. The end 61 is thus the outlet end of the housing. The crop material moves through the rotary crop-processing unit in a crop flow direction from the inlet end 30 to the outlet end 61 of the housing. The operation of the combine is controlled from the operator cab 60 .
[0021] The header 16 can be lifted by use of lift cylinders 63 . The auger 54 can be pivoted via a cylinder or motor (not shown) about a vertical axis between an inboard orientation shown and an outboard orientation, substantially perpendicular to the traveling direction of the combine, to offload grain to a body of a truck. The auger can be pivoted inboard, substantially parallel to the direction of travel of the combine when not in use.
[0022] [0022]FIG. 2 illustrates an exemplary operating system of the combine controlled by a vehicle control unit (VCU) 144 . As will be described, many operating sub-systems, including functional and traction systems, can be controlled by the vehicle control unit (VCU) 144 , including being automatically controlled according to the learn/save and execute features described below. Although in the described exemplary embodiment, many sub-systems are controlled for automatic operation, an operating system incorporating less than all the described functional and traction systems is also encompassed by the invention.
[0023] The combine includes an engine 110 which drives a hydrostatic transmission 111 , which drives a POWERSHIFT transmission 112 , which drives an output drive shaft 116 . The shaft 116 is connected, via a differential 115 , to the wheels 117 which mount the tires 14 (FIG. 1).
[0024] The hydrostatic transmission 111 includes a hydraulic pump 111 a hydraulically coupled to a hydraulic motor 111 b . For a combine having four-wheel drive capability, during four-wheel-drive mode, the hydraulic pump 111 a is hydraulically connected to rear wheel hydraulic motors 124 a , 124 b , one at each rear wheel 125 a , 125 b . The engine 110 also drives a hydraulic pump 127 which supplies pressurized hydraulic fluid to selective control valves or levers.
[0025] The VCU 144 is preferably a microprocessor-based electronic control unit. The VCU 144 receives signals from a control and display panel 148 , an engine speed sensor 152 , preferably a magnetic pickup, and an axle speed sensor 154 , preferably a Hall-effect sensor, which supplies an axle speed signal. The VCU 144 also receives a gear select signal from a shift lever unit 150 and sequence selection signal from a three-position (1, 2 and neutral) switch 156 , such as a commercially available momentary rocker switch. The VCU 144 can receive a crop presence signal from a crop sensor 157 . This sensor can be an optical sensor. The VCU 144 also receives signals from a global positioning system (GPS) 158 . The global positioning system can provide to the VCU 144 the exact position of the combine from a satellite or other reference.
[0026] The VCU 144 is configured to send control signals to the header raise-and-lower system 141 , to an auger deployment system 172 , to a separator adjust system 176 , to a separator engagement system 182 , to a steering system 192 , to a braking system 195 , to a four-wheel drive engage valve 204 , and to an engine throttle control 208 .
[0027] The header raise-and-lower system 141 is an example of a VCU controlled operating sub-system, shown in detail in FIG. 2A. The communication of hydraulic fluid to and from the cylinders 63 is controlled by a pair of solenoid operated electro-hydraulic flow control valves 140 a and 140 b which are operated by drivers 142 a and 142 b which receive electrical control signals generated by the VCU 144 . The header raise-and-lower system 141 also includes a operator-initiated activator 146 , signal-connected to the VCU 144 . The header raise-and-lower system 141 also includes a sensor 206 signal connected to the VCU 144 to feed back header elevation. The sensor 206 can be a potentiometer attached to the feeder house that signals header elevation. Alternatively, the position could be sensed by a radar or sonar sensor sensing the actual header height above the ground.
[0028] Returning to FIG. 2, the auger deployment system 172 could include drivers and valves substantially identical to those shown for the header raise-and-lower system 141 (shown in FIG. 2A) to expand or retract a cylinder to swing the auger. An operator-initiated actuator 173 is signal-connected to the VCU 144 to deploy the auger 54 by swinging the auger perpendicularly to the direction of combine travel, or to retract the auger 54 to a position parallel to the direction of combine travel. The auger deployment system 172 also includes a sensor 207 signal-connected to the VCU 144 to feed back auger deployment position. The sensor can be a potentiometer attached between the auger and the combine body.
[0029] The separator adjust system 176 could also include such drivers and valves to expand or contract a cylinder to adjust clearances in the separator. An operator-initiated actuator 177 such as operator-controlled button, is signal-connected to the VCU 144 to cause adjustment of the separator. The system 176 can also include a sensor 179 signal connected to the VCU 144 to feed back separator clearance. The sensor can be a potentiometer connected to adjustable components of the separator.
[0030] The rotor drive 182 can be actuated by an operator-initiated actuator 184 . The drive 182 includes a suitable drive element 210 which is engaged and disengaged to engine rotary power (via suitable pulleys and belts) by operation of a clutch 212 . The clutch 212 is controlled by electro-hydraulic valves 214 . The electro-hydraulic valves are signal-connected via drivers (now shown) to the VCU 144 and can be controlled by the VCU 144 to effectively engage or disengage engine rotary power to the combine rotor.
[0031] The steering system 192 could include drivers and valves substantially identical to those shown for the header raise-and-lower system 141 to expand or retract a cylinder to turn wheels of the combine to steer the combine. A position sensor 194 can be connected to the steering wheel and signal-connected to the VCU 144 to send a signal corresponding to the steering wheel position.
[0032] A four-wheel drive engagement valve 204 is manually actuated via an actuator 205 to engage or disengage four-wheel drive mode by supplying or diverting, pressurized hydraulic fluid to or from the motors 125 a , 125 b . The valve 204 is signal-connected to the VCU 144 via a suitable driver (not shown).
[0033] A throttle position sensor 220 is connected to the throttle control 208 and signal connected to the VCU 144 , and which sends a signal corresponding to throttle position to the VCU 144 .
[0034] Referring now to FIG. 3, the monitor/display unit 148 is shown. The left-hand third of the monitor/display unit 148 includes a plurality of warning and status lights 260 associated with various vehicle functions, but which do not relate to the present invention. The upper portion of the middle part of the unit 148 includes a graphics/numeric display 262 . The lower portion of the middle part of the unit 148 includes a plurality of touch pad switches 264 which can be used to control what parameters are displayed by the numeric display portion of display 262 . The unit 148 also includes a speaker (not shown) which generates audible sounds in response to certain conditions and operations.
[0035] The right-hand third of the monitor/display unit 148 includes touch pad on/off switch 266 and a learn/save touch pad switch 268 , both of which are used in connection with the function management system. The lower right-hand part of the display 262 includes an implement management system (IMS) display elements 270 and one-two sequence display element 272 , both of which are lit up as a function of the operational status of the present invention, as described in more detail hereinafter.
[0036] To implement the present invention, the VCU 144 executes stored programs. The VCU 144 derives distance information from the speed sensor 154 , using well-known integration techniques. The programmed VCU 144 cooperates with the elements shown in FIGS. 1 and 2 and thereby implements the function management system of the invention.
[0037] Referring to FIG. 4, the Learn Mode operates as follows. First, at step 300 the system is turned on by pressing the on/off switch 266 , and the IMS display indicator 270 turns on. Pressing “learn/save” switch 268 at step 302 activates the learn/save mode and the IMS indicator 270 will begin to flash and a beep with occur periodically. Step 304 allows the learn/save mode to continue if the combine is moving faster than a pre-selected minimum speed. The minimum speed can be zero or greater.
[0038] At step 306 , the operator momentarily toggles the sequence switch 156 to its sequence one or its sequence two position, and the corresponding sequence number of indicator 272 will begin to flash. Then as indicated at 308 , the operator can perform a sequence of manually performed function operations, such as shifting the transmission 118 by manipulating the shift lever 150 , or such as by raising and/or lowering the header by manipulating the header raise/lower switch 146 .
[0039] As indicated at 310 , the VCU 144 records (in a temporary memory) all the manually performed operations together with the various distances traversed by the combine between the various manually initiated operations. Distances are calculated based on actual speed sensed by the sensor 154 and are recorded with a resolution in millimeters. Distance information is recorded only when the combine is moving forward or only when the combine is moving forward faster than a minimum speed.
[0040] At step 312 , the learn/save switch 268 is pressed again and as indicated by step 314 , the VCU 144 stores in a permanent memory the sequence of operations and corresponding distances as either a sequence 1 or a sequence 2, depending on how the switch 156 was previously toggled. The learn/save mode then ends at step 316 and the flashing sequence number 272 stops flashing and the IMS indicator 270 alone remains lit.
[0041] After one or more sequences of operations and distances has been learned and saved by the learn/save mode, the execute mode illustrated by FIG. 5 can be performed. At the step 400 , the on/off 266 is pressed to turn on the system, and the IMS status indicator 270 turns on. Step 402 allows the execute mode to be performed if the combine is moving faster than a pre-selected minimum speed (which could be zero or greater).
[0042] At step 404 , when the combine reaches a location in a field at which the operator desires to execute a stored sequence of operations, the operator momentarily toggles sequence switch 156 to its sequence one or its sequence two position to select which stored sequence will be replayed, and the corresponding “1” or “2” on display 272 is lit. The “1” or “2” sequence indicator 272 will remain on at least three seconds, even if the sequence being executed requires less than three seconds to be executed. Then as indicated at step 406 , the VCU 144 automatically performs the selected sequence of stored operations, such as automatically shifting the transmission 112 without the operator manipulating the shift lever 150 , or such as by automatically raising or lowering the header without the operator manipulating the header raise/lower switch 146 . These stored operations will be replayed with the same relative sequences therebetween as when they were learned, regardless of whether or not the combine is traveling at the same, slower or faster speed. At the completion of a sequence execution, the number 1 or 2 of display 272 will be turned off. The execute mode then ends at step 408 .
[0043] With two learned sequences in the system turned on (and as long as the combine is moving forward faster than a pre-selected minimum speed, the pre-selected minimum speed being zero or greater), the operator may cause the first sequence to be automatically played by momentarily toggling the sequence switch 156 to its “1” position, for example, at the end of every crop row. Similarly, the operator may cause the second sequence to be automatically replayed by momentarily toggling the sequence switch 156 to its “2” position at the start of every crop row.
[0044] Thus, the function management system described herein can be used to automatically replay a sequence of operations at the start of every crop row or cut with a single momentary actuation of sequence switch 156 , and to automatically replay a different sequence of operations at the end of every crop row or cut with a different single momentary actuation of the switch 156 . Because the function management system operates on the basis of distances traveled by the combine, instead of on the basis of time integrals, the sequences can be “learned” slowly as the tractor is moving slowly, and automatically executed or replayed faster as the combine moves at normal operating speeds. This allows the operator plenty of time to operate the “learn” mode and have the control unit 144 “learn” a complex sequence of operations.
[0045] During the operations described above, the invention also operates as follows. A beep will occur when the on/off switch 266 is pressed. When a system is turned on, the contents of the stored sequences will be displayed on the monitor/display 148 . Each sequence, starting with sequence 1, will display each event that was learned and recorded every two seconds followed by the display of “end” on display 262 .
[0046] Learned sequences are retained indefinitely. A maximum preset number, such as 12 operations, can be recorded. The operator can delete a learned sequence from memory. If the “learn/save” mode is canceled during the learning process, i.e., the sequence was not completed normally, then the sequence is cleared from memory. A saved sequence can be removed from memory by entering learn/save mode normally, selecting a sequence, and then hitting the learn/save switch 268 without operating any vehicle functions. This causes the system to exit the learn/save mode and discontinue flashing the sequence number indicator 272 while the “IMS” indicator 270 alone remains on.
[0047] Once the learn/save mode is completed, no operations can be added to the sequence. Distance information will be accumulated only while the combine is in forward drive and above the pre-selected minimum speed.
[0048] The learn/save mode may also be canceled by switching the on/off switch 266 to off or, by: a) not selecting a sequence with sequence switch 156 within a pre-selected time period, b) not learning any operations within a pre-selected time period of the time the sequence switch 156 is toggled, c) not actuating the learn/save mode switch 268 (step 312 ) within a pre-selected time period after a sequence of operations is learned, d) shifting the transmission 118 out of a forward drive, or e) the operator not being present and the combine not moving for more than a pre-selected time period.
[0049] There may be some desired sequences of operations where after the learn/save mode is initiated; the combine is intentionally driven for an accumulated distance before commands for a sequence of operations are started. It may be advantageous then to eliminate the cancellation triggers of steps b) and c) of the preceding paragraph.
[0050] The “IMS” status indicator 270 in the display 262 lights up when the system is on. If the on/off switch 266 is pressed while the function management system is on, then the system shuts off the function management system and turns off the IMS indicator 270 . If the on/off switch 266 is pressed and the sequence switch 156 is not in the neutral position, then the function management system will not be turned on. If the system is in its learn/save mode when the function management system is turned off, then the learn/save mode will be canceled and no sequence of operation will be saved. If the system is executing (replaying) a sequence when the function management system is turned off, the execution of the sequence will abort.
[0051] If the learn/save mode switch 268 is pressed when the function management system is on, the system shall enter into the learn/save mode. A beep will occur when the learn/save mode touch pad switch 268 is pressed. The “IMS” status indicator 270 on display 262 will flash during learn mode and every pre-selected number of seconds, the VCU 144 will generate a beep. If the function management system is not on, pressing the learn/save switch 268 will have no effect.
[0052] If the function management system is off, pressing either part of the sequence switch 156 will have no effect. If the function management system is on and the sequence switch 156 transitions from the neutral position to either the sequence one position or the sequence two position, then the system will begin executing (replaying) the sequence. If the sequence switch 156 is pressed while the learn mode is active, the system will begin learning subsequently manually performed operations.
[0053] Execution of a sequence will always begin at the first operation of the sequence, even if the sequence was previously aborted. During execution mode, the system will always command the learned operation for a function. If the function is already in the state which would result from performance of the learned operation, then the system will have no effect on that function. For example, if the operation is to raise the header, but the header is already fully raised, then execution merely passes along to the next operation of the sequence. If a sequence is already in process and then the sequence switch 156 is toggled for the corresponding sequence again, then the toggling of switch 156 will be ignored and the sequence execution will continue. If a sequence is already in process and then the sequence switch 156 is toggled for the other sequence, then the system will abort the execution of the sequence. If a function is disabled at the time a sequence is commended, then the system will not execute the sequence.
[0054] The header and auger are positioned by the VCU during execute mode based on the learned operation that positions the header or auger according to the absolute position sensed by the sensors 206 , 207 respectively.
[0055] The operator can use the brake pedals to stop the system accumulating distance during a learn/save mode, and to temporarily pause the automatic performance of an operation during execution of a saved sequence. Once thirty seconds has expired, unless the brake pedals are released, the sequence will abort. The system will also prevent execution of a sequence if the transmission gear is above a pre-selected maximum gear unless the sequence was learned above the maximum gear.
[0056] If the operator manually operates a function during automatic sequence execution, then that manually operated function (under this function management system) will be inhibited for the remainder of the execution of the sequence. The other operation of the sequence will be performed as learned, and the particular manually operated operation will not be deleted from the learned sequence.
[0057] As an example of the combine function management system, the situation of a combine approaching the end of cut and turning around and reentering the field at the start of a new cut can be controlled. The end of the cut can be sensed by the crop sensor 157 for automatic deployment of the function management system, or can be seen by the operator for a manual trigger of the function management system. Certain functions must be undertaken at the end of the cut. If the functions are automatically or manually actuated for a sequence one routine, the following actions could be preprogrammed into the VCU 144 . The header is raised by the header raise-and-lower system 141 . The auger deployment system 172 is actuated to retract the auger so as not to strike external objects when the combine is turning around for the next cut. The rotor drive system 182 can be actuated to disengage the rotor clutch so that the rotor is not rotated. The steering system can be automatically controlled to exit the cut and turn to reenter the field. The steering system can be further controlled by the VCU 144 according to signals from the GPS 158 . After leaving the cut, the transmission 118 can be controlled to shift into a higher gear. The engine throttle 208 can also be moved to increase engine speed. The four-wheel drive valve 204 can be actuated to disengage four-wheel drive hydraulic motors 124 a , 124 b . The vehicle brakes can be selectively applied to assist steering. These automatic steps increase maneuverability, speed, fuel efficiency and power.
[0058] When the combine reenters the field, many of these controls are reversed. The four-wheel drive valve 204 is actuated to deliver hydraulic fluid to the hydraulic motor 124 a , 124 b for four-wheel drive mode. The brakes are released. The engine throttle 208 is adjusted for reduced engine speed. The transmission clutches 120 are manipulated to down shift to a lower, more powerful gear. The steering system control can be returned to manual operation or controlled for accurate combine movement along the cut according to a position signal from the GPS 158 . The rotor drive clutch 212 can be actuated to commence rotation of the combine rotor. The separator is adjusted via the separator adjust system 176 . The header 16 is lowered for entering the cut. The auger 172 is deployed substantially perpendicularly to the direction of travel of the combine.
[0059] From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims. | A function management system includes a programmable control unit that can automatically coordinate combine traction functions and/or implement functions. In a learn mode, the operator performs a sequence of manual manipulations of the operator controlled traction and implement devices, and the control unit records and then stores information pertaining to the sequence of device operations. In an execute mode, the control unit automatically performs the sequence of device operations so that the sequence of operations occurs at the same intervals at which they were learned. As one example of a sequence, when the combine approaches the end of a field, at the touch of one button, the header is raised, the unloading auger is pivoted to an inboard position for safe turning, the ground speed is increased for rapid travel, the four wheel drive used during harvesting in the field is disengaged, the crop-processing implement speed, such as a rotor speed for a rotary crop-processing unit, is decreased, and steering of the combine is controlled to position the combine to the point of reentering the field. The sequence of device operations can be pre-programmed or input by the operator in the learn mode. | 0 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a divisional of and claims the benefit of priority from U.S. patent application Ser. No. 09/443,170, filed Nov. 19, 1999, which claims priority from U.S. Provisional Patent Application No. 60/109,325, filed Nov. 20, 1998, the full disclosures of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to the field of heart surgery. In particular, this invention provides a cardiopulmonary bypass device and method for returning oxygenated blood to the aorta artery, after the blood has been drawn from, for example, the vena cava veins or right atrium of a heart. The cardiopulmonary bypass device and method of the invention can advantageously be used in cardiopulmonary bypass performed during minimal invasive cardiovascular surgery with cardioplegia.
[0004] 2. Description of the Prior Art
[0005] Cardiac surgery relates to surgical procedures performed on a patient's heart. To perform such cardiac procedures, the heart is sometimes stopped so that the desired surgical procedure can be performed on a generally stationary heart. Such stopping of the heart is often referred to as cardioplegia. To maintain blood circulation through a patient body while the heart is stopped, a cardiopulmonary bypass is often employed. Traditionally, in the case of open heart surgery, the chest is opened using a median sternotomy to gain access to the heart. In open heart surgery, access to, for example, the aorta, for cross clamping purposes for pulmonary bypass and/or the like, is readily provided. Before stopping the heart, an arterial cannula is typically connected in fluid flow communication with the aorta artery and a venous cannula is typically connected in fluid flow communication with the superior and inferior vena cava veins. The arterial cannula and the venous cannulas typically define apertures of about 0.5 inch in diameter. The cannulae are typically connected to a cardiopulmonary bypass (CPB) system so as to perform cardiopulmonary bypass. In cardiovascular bypass, blood is drawn from the vena cava veins of a patient undergoing coronary surgery. Thereafter, the blood is passed through a venous reservoir and through an oxygenator or artificial lung where it is oxygenated. A major portion of this oxygenated blood is typically filtered and returned to the patient's aorta artery for circulation throughout the body. Thus, the CPB system typically takes over the functions of the heart and the lungs of the patient by oxygenating and pumping the blood through the patient body while the patient's heart is bypassed and stopped.
[0006] Once the CPB system is operatively connected to the patient and brought into operation, the ascending aorta artery is typically cross clamped to isolate the coronary arteries from the rest of the arterial system. Thereafter, cardiac arrest is induced by typically injecting 500 to 1000 cc of cardioplegic solution into an aortic root using a needle or cannula which pierces the wall of the ascending aorta artery upstream of the cross clamp. Cardioplegic solution typically comprises aqueous solutions of potassium chloride and often contains additional substances such as dextrose, glutamate, aspartate, and various other electrolytes such as Ca +2 and Mg +2 . The punctures of the 0.5 inch diameter venous cannulae and the arterial cannula on the two vena cava veins and on the aorta artery, respectively, often require repair before the heart can be restarted. This is typically accomplished by means of suturing. After such suturing, and after the heart is then restarted, the sutures need to be closely monitored so as to ensure that the punctures have been adequately repaired thereby to inhibit rupturing and internal bleeding after completion of the surgery.
[0007] Typically, the foregoing procedure does not present a large problem when open chest heart surgery is to be performed since the surgeon is provided with ready access to the vena cava veins and the aorta artery. However, it can happen that the surgical procedure is to be performed in a manner other than open surgery. Accordingly, in such a case, and where pulmonary bypass is required, ready access to the vena cava veins and the aorta artery may not be readily available. This is typically the case where, for example, the surgical procedure is to be performed in a minimally invasive surgical manner.
[0008] Minimally invasive surgery is a relatively recent and very important development in the field of surgery. Generally, minimally invasive surgical techniques use endoscopic or transluminal surgical approaches in performing surgery so as to inhibit trauma and morbidity associated with relatively more invasive surgical techniques such as the open heart surgical technique described above. Minimally invasive surgical techniques have been, and are in the process of being, developed to perform surgical procedures by means of endoscopic or transluminal techniques. It is desirable that myocardial protection and cardiopulmonary support are catered for in a minimally invasive manner to obviate the need to open the patient's chest, so as to permit the cardiac procedure to be conducted fully in a minimally invasive manner. Current methods of cardioplegia and performing cardiopulmonary bypass do not adequately meet this desire as evidenced in the following prior art U.S. patents, the full disclosures of which are fully incorporated herein by reference: U.S. Pat. No. 4,712,551 to Rayhanabad; U.S. Pat. No. 4,979,937 to Khoransani; U.S. Pat. No. 5,190,538 to Fonger et al.; U.S. Pat. No. 5,466,216 to Brown et al.; and U.S. Pat. No. 5,695,457 to St. Goar et al.
[0009] U.S. Pat. No. 4,712,551 to Rayhanabad discloses a vascular shunt having a plurality of branches. The various embodiments of the vascular shunt are depicted in FIGS. 1 and 8 of this patent.
[0010] U.S. Pat. No. 4,979,937 to Khoransani discloses a plurality of small cannulas connected to Y-connectors and to larger cannulas for providing blood flow during aortic procedures. More specifically, and as can best be seen with reference to FIGS. 1 and 2 of this patent, there is seen an intercostal and lumbar perfusion apparatus having a main member and a plurality of side members communicating with the main member via a Y-connector. The apparatus disclosed in this patent provides blood flow to distal organs and intercostals during aortic surgery.
[0011] U.S. Pat. No. 5,190,538 to Fonger et al. discloses a cannula within the left atrium of the heart for draining blood and returning it via an arterial cannula after passing through an extra-corporeal pump. The atrium of the heart is pierced by a needle assembly to enable insertion of a catheter and the cannula.
[0012] U.S. Pat. No. 5,466,216 to Brown et al. discloses a pair of cannulae, respectively, inserted into the aortic root and the coronary sinus of a heart (see FIG. 1). A system or assembly interconnects the two cannulae for delivery of blood and cardioplegic solution to the aortic root for antegrade infusion or to the coronary sinus for retrograde infusion.
[0013] U.S. Pat. No. 5,695,547 to St. Goar et al. discloses a complete cardioplegia and cardiopulmonary bypass system. The devices disclosed in this patent induce cardioplegic arrest for myocardial protection during cardiac surgery by direct perfusion of the coronary arteries using a transluminal approach from a peripheral arterial entry point.
[0014] The prior art above does not teach a method or an apparatus whereby cardiopulmonary bypass can be performed without having to repair cannula punctures in the aorta artery and the vena cava veins after termination of a cardiopulmonary bypass procedure.
[0015] It is an object of the present invention to provide a method of performing cardiovascular bypass for cardiac surgery with cardioplegia.
[0016] It is another object of the present invention to provide a method of performing cardiopulmonary bypass for minimal invasive cardiovascular surgery with cardioplegia.
[0017] It is another object of the present invention to provide a cardiopulmonary bypass system.
[0018] It is another object of this invention to provide an apparatus and method whereby cardiopulmonary bypass can be performed without having to repair punctures in the aorta after the cardiopulmonary bypass has been completed. It is a further object of the invention to provide a cardiopulmonary bypass apparatus and method which also inhibits having to repair punctures in the vena cava veins upon completion of the cardiopulmonary bypass procedure.
SUMMARY OF THE INVENTION
[0019] According to one aspect of the invention, a method of performing a cardiopulmonary bypass procedure is provided. The method includes accessing a source of blood in a patient body from which source the blood is to be passed through a cardiopulmonary bypass machine, drawing blood from the source through the cardiopulmonary bypass machine and introducing the blood into an aortic artery of the patient body through a plurality of separate passages, after the blood has been passed through the cardiopulmonary bypass machine.
[0020] According to another aspect of the invention, there is provided a cardiopulmonary bypass system comprising a cardiopulmonary bypass machine, a tubular member coupled to an outlet port of the cardiopulmonary bypass machine and a plurality of separate needle members connected in fluid flow communication with the tubular member, the needle members being arranged to be connected in fluid flow communication with an aortic artery, during a cardiopulmonary bypass procedure.
[0021] According to yet a further aspect of the invention, there is provided a method of performing cardiovascular bypass for cardiac surgery with cardioplegia, the method comprising the steps of:
[0022] a) inserting a plurality of needle members into a right atrium of a patient's heart;
[0023] b) flowing blood from the right atrium of the patient's heart, through the plurality of needle members, and to a cardiopulmonary bypass machine where the blood is oxygenated to produce oxygenated blood; and
[0024] c) flowing the oxygenated blood of step (b) into an aorta artery extending from the patient's heart such that cardiovascular bypass is performed for cardiac surgery with cardioplegia.
[0025] The immediate foregoing method may additionally comprise inserting, prior to the flowing step (c), a plurality of a aorta needle members into the aorta artery extending from the patient's heart. The flowing step (c) may comprise flowing oxygenated blood through the aorta needle members and into the aorta artery. Preferably, the aorta artery is occluded (e.g., such as by pinching the aorta artery) at a location between the patient's heart and the aorta needle members. In a preferred embodiment of the invention, the inserting step (a) includes inserting the needle members into a right auricle of the patient's heart. The needle members may each be dimensioned with an inside diameter such that each needle member has blood flowing therethrough at a respective volumetric flow rate. Similarly, the aorta needle members may each be dimensioned with an inside diameter such that each aorta needle member has blood flowing therethrough also at a respective volumetric flow rate. The needle members may communicate with a tubular member which preferably may be dimensioned with an internal diameter such that the blood flowing through the tubular member has a volumetric flow rate that is approximately equal to the sum of the respective volumetric flow rates of the blood flowing through the plurality of needle members. Similarly, the aorta needle members may communicate with a tubular member that may be dimensioned with an internal diameter such that the oxygenated blood flowing through the tubular member has a volumetric flow rate that is approximately equal to the respective volumetric flow rates of the oxygenated blood flowing through the plurality of aorta needle members.
[0026] According to yet another aspect of the invention, there is provided a method of performing cardiopulmonary bypass for minimal invasive cardiovascular surgery with cardioplegia, the method comprising the steps of:
[0027] (a) providing a plurality of first needle members communicating with a first tubular member which is coupled to a cardiopulmonary bypass assembly;
[0028] (b) providing a plurality of second needle members communicating with a second tubular member which is coupled to the cardiopulmonary bypass assembly;
[0029] (c) providing a plurality of third needle members communicating with a third tubular member which is coupled to the cardiopulmonary bypass assembly;
[0030] (d) inserting a plurality of first needle members into a superior vena cava vein extending to a heart of a patient;
[0031] (e) inserting a plurality of second needle members into an inferior vena cava vein extending to the heart of the patient;
[0032] (f) inserting the plurality of third needle members into an aorta artery extending from the heart of the patient;
[0033] (g) occluding the superior vena cava vein at a location between the first needle members of step (d) and the heart of the patient, causing blood to flow from the superior vena cava vein, through the first needle members, and through the first tubular member to the cardiopulmonary bypass assembly where the blood is oxygenated;
[0034] (h) occluding the inferior vena cava vein at a location between the second needle members of step (e) and the heart of the patient, causing blood to flow from the inferior vena cava vein, through the second needle members, and through the second tubular member to the cardiopulmonary bypass assembly where the blood is oxygenated;
[0035] (i) occluding the aorta artery at a location between the third needle members of step (f) and the heart of the patient; and
[0036] (j) flowing oxygenated blood from the cardiopulmonary bypass assembly, through the third tubular member, and through the third needle members and into the aorta artery such that cardiopulmonary bypass is performed for minimal invasive cardiovascular surgery with cardioplegia.
[0037] According to yet a further aspect of the invention, there is provided a cardiopulmonary bypass system comprising a cardiopulmonary bypass assembly, a first tubular member coupled to the cardiopulmonary bypass assembly and a plurality of first needle members coupled to the first tubular member, a second tubular member also coupled to the cardiopulmonary bypass assembly and a plurality of second needle members coupled to the second tubular member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] The invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which:
[0039] [0039]FIG. 1 shows an elevational view of a human heart;
[0040] [0040]FIG. 2A shows a schematic diagram of a cardiopulmonary bypass system, in accordance with the invention, which includes needle devices also in accordance with the invention;
[0041] [0041]FIG. 2B shows, at an enlarged scale, a sectional view taken along arrows 2 B- 2 B in FIG. 2A;
[0042] [0042]FIG. 3 shows, at an enlarged scale, a sectional view of a superior vena cava vein in fluid flow communication with a human heart of a patient, and further shows a plurality of needle members extending into the superior vena cava vein, in accordance with one aspect of the invention, such that blood can be drawn from the superior vena cava vein through the needle members during cardiopulmonary bypass;
[0043] [0043]FIG. 4 shows, at an enlarged scale, a sectional view of an inferior vena cava vein in fluid flow communication with a human heart of a patient, and further shows a plurality of needle members extending into the inferior vena cava vein, in accordance with another aspect of the invention, such that blood can be drawn from the inferior vena cava vein during cardiopulmonary bypass in accordance with the invention;
[0044] [0044]FIG. 5 shows, at an enlarged scale, a sectional view of an aorta artery in fluid flow communication with a human heart of a patient, and shows a plurality of aorta needle members extending into the aorta artery, in accordance with the invention, such that blood can be introduced into the aorta through the needle members, during cardiopulmonary bypass in accordance with the invention;
[0045] [0045]FIG. 6 corresponds to FIG. 3 and shows the superior vena cava vein being occluded by pinching it at a location between the needle members and the human heart;
[0046] [0046]FIG. 7 corresponds to FIG. 4 and shows the inferior vena cava vein occluded by pinching at the location between the needle members and the human heart;
[0047] [0047]FIG. 8 corresponds to FIG. 5 and shows the aorta being occluded by pinching at the location between the aorta needle members and the human heart; and
[0048] [0048]FIG. 9 corresponds to FIG. 1 and shows a plurality of needle members piercing the right auricle of the right atrium of the human heart.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0049] The invention will now be described with reference to FIGS. 1 - 9 . In FIGS. 1 - 9 , like reference numerals are used to designate similar parts unless otherwise stated. Although the present invention will now be described in the context of both delivering oxygen-depleted blood to a cardiopulmonary bypass machine and returning oxygenated blood from the bypass machine to the patient's circulatory system, e.g., a patient's aorta, without having to repair punctures in the various vessels or body organs to which the invention is applied, it should be understood that the invention will provide distinct advantages over the existing systems and methods for returning oxygenated blood to the patient even if another method of cannulating the patient's venous system is used as a source of blood for the bypass machine. In addition, it should be understood that the practice of this invention is not limited solely to minimally invasive procedures, but instead has application to any operation in which the surgeon desires to acquire a source of blood from, and/or deliver blood or other fluids (such as, e.g., saline or pharmaceutical-laced fluids) to a patient's body, most preferably to the patient's circulatory system.
[0050] Referring to FIG. 1, a human heart is generally indicated by reference numeral 8 . Referring to FIG. 2A, a cardiovascular bypass system in accordance with the invention, is generally indicated by reference numeral 10 . The system 10 of the invention utilizes needle assemblies to access the superior and inferior vena cava veins and aorta artery respectively so as to perform cardiopulmonary bypass.
[0051] Referring again to FIG. 1, the superior vena cava vein is indicated by reference numeral 14 and the inferior vena cava vein is indicated by reference numeral 16 . The veins 14 , 16 are connected in fluid flow communication with the heart 8 . The superior vena cava 14 and the inferior vena cava 16 feed blood to the heart after the blood has been circulated throughout a patient body (not shown). The right atrium of the heart 8 is shown at 9 , and the right auricle is indicated at 9 a . The aorta artery is indicated at 11 and is connected in fluid flow communication with the heart to feed blood from the heart into the circulation system of the patient body. The right ventricle of the heart is indicated at 13 , the left atrium at 15 , and the left auricle at 15 a . A pulmonary trunk is indicated at 17 .
[0052] The cardiovascular bypass system 10 , in accordance with the invention, will now be described in greater detail with reference to FIG. 2A. The system 10 includes needle assemblies generally indicated at 60 , 64 , and 68 , respectively. The needle assemblies 60 , 64 are arranged to access and draw blood from the superior vena cava 14 and the inferior vena cava 16 , respectively. The needle assembly 60 comprises a plurality of access needles 18 a , 18 b , 18 c , 18 d , generally indicated at 18 , each of which is connected in fluid flow communication with a tube assembly, generally indicated at 70 . The tube assembly 70 comprises tubes 70 a , 70 b , 70 c , 70 d , each of which is connected in fluid flow communication with a single tube 72 . Each of the needles 18 is connected to a free end of one of the tubes of the tube assembly 70 .
[0053] Needle assembly 64 includes a plurality of access needles 19 a , 19 b , 19 c , 19 d , which are generally indicated at 19 . The needles at 19 are connected in fluid flow communication with a tube assembly, generally indicated at 74 . The tube assembly 74 is connected in fluid flow communication with a tube 76 . The tube assembly 74 includes a plurality of tube members 74 a , 74 b , 74 c , 74 d , each of which is connected in fluid flow communication with the tube 76 . The needles 19 are connected in fluid flow communication with free ends of the tubes at 74 .
[0054] The tubes 72 , 76 are connected in fluid flow communication with a tube 75 . Advantageously, back pressure, uniflow, or check valves 72 a , 76 a , can be provided to inhibit backflow of blood therethrough.
[0055] The needle assembly 68 is arranged to feed oxygenated blood to the aorta artery 11 . Needle assembly 68 comprises a plurality of needles 21 a , 21 b , 21 c , 21 d , generally indicated by reference numeral 21 , each of which is connected in fluid flow communication with a tube assembly 78 . The tube assembly 78 includes separate tubes 78 a , 78 b , 78 c , 78 d , each of which is connected in fluid flow communication with a common tube 80 . Conveniently, a backpressure valve 82 can be provided to inhibit back flow of oxygenated blood.
[0056] The tubes 75 , 80 are connected in fluid flow communication with a cardiovascular bypass machine, or assembly, generally indicated at 79 . The cardiovascular bypass assembly 79 comprises an oxygenator 100 , a pump 102 , an arterial filter 104 , a suction wand 106 , a blood oxygen saturation measuring and charting device 108 , and a cardiotomy reservoir 110 . It further comprises an inlet 75 a to which the tube 75 is connected in fluid flow communication and an outlet 80 a to which the tube 80 is connected in fluid flow communication.
[0057] Referring to FIG. 2B of the drawings, each of the needles 18 , 19 , 21 is typically in the form of a slender surgical needle having a sharp point or end for piercing tissue. The needles 18 , 19 , 21 can be made of any appropriate material, such as steel, stainless steel, or the like. Each of the needles 18 , 19 , 21 typically has an outer diameter D o of less than about 0.4 inches. Preferably, the needles have an outer diameter D o of less than 0.36 inches. Advantageously, each of the needles 18 , 19 , 21 may have an outer diameter D o falling in the range between about 0.3 inches or less.
[0058] The outer diameters D o of the needles 18 , 19 , 21 are typically sufficiently small so that when the needles are used to puncture the vena cava veins and the aorta artery respectively, to perform cardiopulmonary bypass in accordance with the invention, the punctures are of a size such that when the needles are withdrawn from the vena cava veins and the aorta artery, the punctures do not need to be repaired, e.g., by means of suturing, or the like. In accordance with conventional cardiopulmonary bypass techniques, the arterial cannula and venous cannulae which are typically used to access the aorta and the vena cava veins, are of a size which, when used during a cardiopulmonary bypass operation, form punctures in the vena cava veins and the aorta artery, respectively, which are of a size which requires repair after the cardiopulmonary bypass operation has been completed. It has been found that when a needle having an outer diameter of greater than about 0.5 inch is used to pierce the vena cava veins or the aorta artery, then repair is typically required to seal the puncture. Such repair is typically performed by means of suturing. Each needle typically has a sharp end, as can best be seen in FIG. 2B as indicated at E with reference to needle 19 a.
[0059] It will be appreciated that each of the needle groups 18 , 19 , 21 are shown as having four needles for illustrative purposes only. Naturally, the number of needles used can vary and may depend on the internal diameter D i of each needle, the size of the vena cava veins 14 , 16 and the aorta artery 11 , the blood flow rate of the patient, and the like.
[0060] Each of the tubes of the groups 70 , 74 , 78 preferably has an internal diameter corresponding to the internal diameter of the needle attached to the tube. Accordingly, and as can best be seen with reference to FIG. 2B, the tube 74 a has an internal diameter 74 id that is generally equal to the internal diameter D i of the needle 19 a . Preferably, the individual needles of the needle groups 18 , 19 , 21 , and the individual tubes of the tube groups 70 , 74 , 78 are all internally dimensioned with internal diameters such that there is a generally constant, smooth volumetric flow rate (e.g., in cc/unit of time) of blood through the individual needles and their associated tubes. Tubes 72 , 76 have internal diameters such that the sum of the volumetric flow rates of blood flowing through the individual tubes 70 a , 70 b , 70 c , 70 d , and individual tubes 74 a , 74 b , 74 c , 74 d , respectively, generally equal the volumetric flow rate of blood flowing through the tubes 72 and 76 , respectively. Tube 75 is also internally dimensioned with an internal diameter such that the sum of the volumetric flow rates of blood flowing through tubes 72 , 76 is generally equal to the volumetric flow rate of blood flowing through tube 75 . Furthermore, tube 80 typically has an internal diameter such that the volumetric flow rate of blood flowing through the tube 80 is preferably about equal to the sum of the volumetric flow rates of blood flowing through the individual tubes 78 a , 78 b , 78 c , 78 d.
[0061] It will be appreciated that the number of needles 18 , 19 , 21 and their internal diameters D i are chosen such that there is a consistent and smooth drawing of blood from the vena cava veins 14 , 16 or from the right atrium 9 , and a consistent and smooth supply of oxygenated blood into the aorta artery 11 , so as to inhibit trauma to the patient. Furthermore, the outside diameters D o of the needles 18 , 19 , 21 are chosen such that after completion of the cardiopulmonary bypass, repair to the vena cava veins and the aorta artery to seal the punctures after the needles have been withdrawn would not be required.
[0062] In use, when a cardiopulmonary operation is performed using the system 10 , the needles 18 a , 18 b , 18 c , 18 d of needle assembly 60 and the needles 19 a , 19 b , 19 c , 19 d of needle assembly 64 are introduced, preferably minimally invasively, into the superior vena cava 14 (see FIG. 3) and into the inferior vena cava 16 (see FIG. 4), respectively. With reference to FIG. 9, by way of example, the needles 18 can be inserted into the right auricle 9 a of the right atrium 9 of the heart 8 instead of into the superior vena cava 14 . It will be appreciated that, instead, the needles 19 can be inserted into the right auricle. Furthermore, alternatively both the needles 18 , 19 in combination can be inserted into the right auricle 9 a.
[0063] The needles 21 a , 21 b , 21 c , 21 d of the needle assembly 68 are inserted into the aorta artery 11 , as can best be seen with reference to FIG. 5.
[0064] Once the respective needles have been inserted into the vena cava veins and the aorta artery, the aorta 11 is typically occluded. Such occlusion can be achieved in any appropriate manner with any appropriate apparatus or device. In one embodiment of the invention, the vena cava veins 14 , 16 are respectively occluded by pinching them with pincher devices 120 , 124 (see FIGS. 6 and 7) at the location on the vena cava vein 14 between the needles 18 a , 18 b , 18 c , 18 d and the heart 8 , and at a location on the vena cava vein 16 between needles 19 a , 19 b , 19 c , 19 d and the heart 8 , respectively. The aorta artery 11 is preferably occluded by pinching it with pincher 128 (see FIG. 8) at a location on the aorta artery 11 between needles 21 a , 21 b , 21 c , 21 d and the heart 8 .
[0065] To perform the cardiopulmonary bypass, blood is then drawn from the superior vena cava 14 and the inferior vena cava 16 through the needle groups 18 , 19 , respectively. The blood drawn from the vena cava veins 14 , 16 then flows from the needles 18 , 19 through tube assembly 70 and tube assembly 74 and then into the tube 72 , 76 , and then into the tube 75 . The blood is then fed to the oxygenator 100 by means of the tube 75 , where oxygen is added to the blood and carbon dioxide is removed from the blood thereby to simulate the function of the patient's lungs.
[0066] Upon exiting the oxygenator 100 , a main portion of the oxygenated blood flows to the pump 102 which pumps the blood to the arterial filter 104 . The effectiveness of the oxygenator 100 is measured by an inline connection (not shown) to the blood oxygen saturation measuring and charting device 108 . At the arterial filter 104 , particulate matter and micro-air emboli from the oxygenated blood are removed and the filtered oxygenated blood is returned to the body of the patient through the tube 80 . From the tube 80 , blood flows through the tube assembly 78 and then through the needles 21 and into the aorta artery 11 . In this manner, blood is circulated through the body while the heart is stopped, the cardiopulmonary system 10 simulating heart and lung function of the patient. Any blood which escapes the patient's circulatory system during the operation, is typically sucked from the chest or pleural cavity by means of a suction wand 106 . The sucked blood is directed to the cardiotomy reservoir 110 . In the cardiotomy reservoir 110 , the blood is defoamed and filtered and fed to the oxygenator 100 to be oxygenated and returned to the patient, in the manner described above.
[0067] Instead of drawing blood from the vena cava veins as described above, and as already mentioned, blood can be withdrawn from the atrium 9 of the heart 8 . As can best be seen with reference to FIG. 9, the needles of the needle group 18 can be inserted into the right auricle 9 a of the right atrium 9 of the heart 8 . Blood is then caused to flow through needles 18 , through tube assembly 70 and tube 72 , and then through tube 75 and into the cardiovascular bypass assembly 79 where the blood is oxygenated, processed and returned to the patient in accordance with the manner described above.
[0068] Accordingly, in the manner described above, a method of performing cardiovascular bypass is provided to facilitate cardiac surgery with cardioplegia. While the methods described above have been described by employing needles 18 , tube assembly 70 and tube 72 , it is to be appreciated that the same method may be conducted by employing needles 19 , or a combination of needles 18 , 19 , and any tube assembly and tube(s) associated therewith. The method(s) of the present invention for performing cardiovascular bypass may be performed for the purpose of performing any type of cardiac surgery with cardioplegia. The cardiopulmonary bypass system of the invention can advantageously be used to perform cardiopulmonary bypass in accordance with the above method(s) when cardiovascular surgery is to be performed with cardioplegia, in a minimally invasive manner.
[0069] Thus, while the present invention has been described with reference to particular embodiments, a latitude of modification, various changes and substitutions are intended in the foregoing disclosure and it will be appreciated that in some instances some features of the invention will be employed without a corresponding use of other features without departing from the scope and spirit of the invention as set forth. Therefore, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope and spirit of the present invention. It is intended that the invention not be limited to the particular embodiments disclosed as the best mode contemplates for carrying out this invention, but that the invention will include all embodiments and equivalents falling within the scope of the appended claims. | A method and system for performing a cardiopulmonary bypass procedure are provided. The method includes accessing a source of blood in a patient body from which source the blood is to be passed through a cardiopulmonary bypass machine, drawing blood from the source through the cardiopulmonary bypass machine and introducing the blood into an aortic artery of the patient body through a plurality of separate passages, after the blood has been passed through the cardiopulmonary bypass machine. The system comprises a cardiopulmonary bypass machine, a tubular member coupled to an outlet port of the cardiopulmonary bypass machine and a plurality of separate needle members connected in fluid flow communication with the tubular member, the needle members being arranged to be connected in fluid flow communication with an aortic artery, during a cardiopulmonary bypass procedure. | 0 |
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